Auto merge of #81625 - jonas-schievink:rollup-mshpp2n, r=jonas-schievink

Rollup of 12 pull requests

Successful merges:

 - #78641 (Let io::copy reuse BufWriter buffers)
 - #79291 (Add error message for private fn)
 - #81364 (Improve `rustc_mir_build::matches` docs)
 - #81387 (Move some tests to more reasonable directories - 3)
 - #81463 (Rename NLL* to Nll* accordingly to C-CASE)
 - #81504 (Suggest accessing field when appropriate)
 - #81529 (Fix invalid camel case suggestion involving unicode idents)
 - #81536 (Indicate both start and end of pass RSS in time-passes output)
 - #81592 (Rustdoc UI fixes)
 - #81594 (Avoid building LLVM just for llvm-dwp)
 - #81598 (Fix calling convention for CRT startup)
 - #81618 (Sync rustc_codegen_cranelift)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

Cargo.lock

@@ -4133,6 +4133,7 @@ dependencies = [
  "rustc_middle",
  "rustc_session",
  "rustc_span",
+ "rustc_trait_selection",
  "rustc_typeck",
  "tracing",
 ]

compiler/rustc_codegen_cranelift/.github/workflows/main.yml

@@ -12,6 +12,9 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, macos-latest]
+        env:
+          - BACKEND: ""
+          - BACKEND: --oldbe
 
     steps:
     - uses: actions/checkout@v2
@@ -51,7 +54,7 @@ jobs:
         export COMPILE_RUNS=2
         export RUN_RUNS=2
 
-        ./test.sh
+        ./test.sh $BACKEND
 
     - name: Package prebuilt cg_clif
       run: tar cvfJ cg_clif.tar.xz build

compiler/rustc_codegen_cranelift/.gitignore

@@ -8,6 +8,7 @@ perf.data.old
 *.string*
 /build
 /build_sysroot/sysroot_src
+/build_sysroot/compiler-builtins
 /rust
 /rand
 /regex

compiler/rustc_codegen_cranelift/.vscode/settings.json

@@ -1,7 +1,7 @@
 {
     // source for rustc_* is not included in the rust-src component; disable the errors about this
     "rust-analyzer.diagnostics.disabled": ["unresolved-extern-crate"],
-    "rust-analyzer.assist.importMergeBehaviour": "last",
+    "rust-analyzer.assist.importMergeBehavior": "last",
     "rust-analyzer.cargo.loadOutDirsFromCheck": true,
     "rust-analyzer.linkedProjects": [
         "./Cargo.toml",

compiler/rustc_codegen_cranelift/Cargo.lock

@@ -2,9 +2,9 @@
 # It is not intended for manual editing.
 [[package]]
 name = "anyhow"
-version = "1.0.34"
+version = "1.0.38"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bf8dcb5b4bbaa28653b647d8c77bd4ed40183b48882e130c1f1ffb73de069fd7"
+checksum = "afddf7f520a80dbf76e6f50a35bca42a2331ef227a28b3b6dc5c2e2338d114b1"
 
 [[package]]
 name = "ar"
@@ -25,15 +25,15 @@ checksum = "cf1de2fe8c75bc145a2f577add951f8134889b4795d47466a54a5c846d691693"
 
 [[package]]
 name = "byteorder"
-version = "1.3.4"
+version = "1.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "08c48aae112d48ed9f069b33538ea9e3e90aa263cfa3d1c24309612b1f7472de"
+checksum = "ae44d1a3d5a19df61dd0c8beb138458ac2a53a7ac09eba97d55592540004306b"
 
 [[package]]
 name = "cc"
-version = "1.0.62"
+version = "1.0.66"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f1770ced377336a88a67c473594ccc14eca6f4559217c34f64aac8f83d641b40"
+checksum = "4c0496836a84f8d0495758516b8621a622beb77c0fed418570e50764093ced48"
 
 [[package]]
 name = "cfg-if"
@@ -49,16 +49,16 @@ checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
 [[package]]
 name = "cranelift-bforest"
-version = "0.68.0"
+version = "0.69.0"
-source = "git+https://github.com/bytecodealliance/wasmtime/?branch=main#8f7f8ee0b4c5007ace6de29b45505c360450b1bb"
+source = "git+https://github.com/bytecodealliance/wasmtime/?branch=main#986b5768f9e68f1564b43f32b8a4080a6582c8ca"
 dependencies = [
  "cranelift-entity",
 ]
 
 [[package]]
 name = "cranelift-codegen"
-version = "0.68.0"
+version = "0.69.0"
-source = "git+https://github.com/bytecodealliance/wasmtime/?branch=main#8f7f8ee0b4c5007ace6de29b45505c360450b1bb"
+source = "git+https://github.com/bytecodealliance/wasmtime/?branch=main#986b5768f9e68f1564b43f32b8a4080a6582c8ca"
 dependencies = [
  "byteorder",
  "cranelift-bforest",
@@ -75,8 +75,8 @@ dependencies = [
 
 [[package]]
 name = "cranelift-codegen-meta"
-version = "0.68.0"
+version = "0.69.0"
-source = "git+https://github.com/bytecodealliance/wasmtime/?branch=main#8f7f8ee0b4c5007ace6de29b45505c360450b1bb"
+source = "git+https://github.com/bytecodealliance/wasmtime/?branch=main#986b5768f9e68f1564b43f32b8a4080a6582c8ca"
 dependencies = [
  "cranelift-codegen-shared",
  "cranelift-entity",
@@ -84,18 +84,18 @@ dependencies = [
 
 [[package]]
 name = "cranelift-codegen-shared"
-version = "0.68.0"
+version = "0.69.0"
-source = "git+https://github.com/bytecodealliance/wasmtime/?branch=main#8f7f8ee0b4c5007ace6de29b45505c360450b1bb"
+source = "git+https://github.com/bytecodealliance/wasmtime/?branch=main#986b5768f9e68f1564b43f32b8a4080a6582c8ca"
 
 [[package]]
 name = "cranelift-entity"
-version = "0.68.0"
+version = "0.69.0"
-source = "git+https://github.com/bytecodealliance/wasmtime/?branch=main#8f7f8ee0b4c5007ace6de29b45505c360450b1bb"
+source = "git+https://github.com/bytecodealliance/wasmtime/?branch=main#986b5768f9e68f1564b43f32b8a4080a6582c8ca"
 
 [[package]]
 name = "cranelift-frontend"
-version = "0.68.0"
+version = "0.69.0"
-source = "git+https://github.com/bytecodealliance/wasmtime/?branch=main#8f7f8ee0b4c5007ace6de29b45505c360450b1bb"
+source = "git+https://github.com/bytecodealliance/wasmtime/?branch=main#986b5768f9e68f1564b43f32b8a4080a6582c8ca"
 dependencies = [
  "cranelift-codegen",
  "log",
@@ -105,8 +105,8 @@ dependencies = [
 
 [[package]]
 name = "cranelift-jit"
-version = "0.68.0"
+version = "0.69.0"
-source = "git+https://github.com/bytecodealliance/wasmtime/?branch=main#8f7f8ee0b4c5007ace6de29b45505c360450b1bb"
+source = "git+https://github.com/bytecodealliance/wasmtime/?branch=main#986b5768f9e68f1564b43f32b8a4080a6582c8ca"
 dependencies = [
  "anyhow",
  "cranelift-codegen",
@@ -123,8 +123,8 @@ dependencies = [
 
 [[package]]
 name = "cranelift-module"
-version = "0.68.0"
+version = "0.69.0"
-source = "git+https://github.com/bytecodealliance/wasmtime/?branch=main#8f7f8ee0b4c5007ace6de29b45505c360450b1bb"
+source = "git+https://github.com/bytecodealliance/wasmtime/?branch=main#986b5768f9e68f1564b43f32b8a4080a6582c8ca"
 dependencies = [
  "anyhow",
  "cranelift-codegen",
@@ -135,8 +135,8 @@ dependencies = [
 
 [[package]]
 name = "cranelift-native"
-version = "0.68.0"
+version = "0.69.0"
-source = "git+https://github.com/bytecodealliance/wasmtime/?branch=main#8f7f8ee0b4c5007ace6de29b45505c360450b1bb"
+source = "git+https://github.com/bytecodealliance/wasmtime/?branch=main#986b5768f9e68f1564b43f32b8a4080a6582c8ca"
 dependencies = [
  "cranelift-codegen",
  "raw-cpuid",
@@ -145,8 +145,8 @@ dependencies = [
 
 [[package]]
 name = "cranelift-object"
-version = "0.68.0"
+version = "0.69.0"
-source = "git+https://github.com/bytecodealliance/wasmtime/?branch=main#8f7f8ee0b4c5007ace6de29b45505c360450b1bb"
+source = "git+https://github.com/bytecodealliance/wasmtime/?branch=main#986b5768f9e68f1564b43f32b8a4080a6582c8ca"
 dependencies = [
  "anyhow",
  "cranelift-codegen",
@@ -209,9 +209,9 @@ checksum = "d7afe4a420e3fe79967a00898cc1f4db7c8a49a9333a29f8a4bd76a253d5cd04"
 
 [[package]]
 name = "indexmap"
-version = "1.6.0"
+version = "1.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "55e2e4c765aa53a0424761bf9f41aa7a6ac1efa87238f59560640e27fca028f2"
+checksum = "4fb1fa934250de4de8aef298d81c729a7d33d8c239daa3a7575e6b92bfc7313b"
 dependencies = [
  "autocfg",
  "hashbrown",
@@ -219,15 +219,15 @@ dependencies = [
 
 [[package]]
 name = "libc"
-version = "0.2.80"
+version = "0.2.82"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4d58d1b70b004888f764dfbf6a26a3b0342a1632d33968e4a179d8011c760614"
+checksum = "89203f3fba0a3795506acaad8ebce3c80c0af93f994d5a1d7a0b1eeb23271929"
 
 [[package]]
 name = "libloading"
-version = "0.6.5"
+version = "0.6.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1090080fe06ec2648d0da3881d9453d97e71a45f00eb179af7fdd7e3f686fdb0"
+checksum = "351a32417a12d5f7e82c368a66781e307834dae04c6ce0cd4456d52989229883"
 dependencies = [
  "cfg-if 1.0.0",
  "winapi",
@@ -235,9 +235,9 @@ dependencies = [
 
 [[package]]
 name = "log"
-version = "0.4.11"
+version = "0.4.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4fabed175da42fed1fa0746b0ea71f412aa9d35e76e95e59b192c64b9dc2bf8b"
+checksum = "fcf3805d4480bb5b86070dcfeb9e2cb2ebc148adb753c5cca5f884d1d65a42b2"
 dependencies = [
  "cfg-if 0.1.10",
 ]
@@ -272,9 +272,9 @@ dependencies = [
 
 [[package]]
 name = "quote"
-version = "1.0.7"
+version = "1.0.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "aa563d17ecb180e500da1cfd2b028310ac758de548efdd203e18f283af693f37"
+checksum = "991431c3519a3f36861882da93630ce66b52918dcf1b8e2fd66b397fc96f28df"
 dependencies = [
  "proc-macro2",
 ]
@@ -333,6 +333,7 @@ dependencies = [
  "indexmap",
  "libloading",
  "object",
+ "smallvec",
  "target-lexicon",
 ]
 
@@ -362,15 +363,15 @@ checksum = "388a1df253eca08550bef6c72392cfe7c30914bf41df5269b68cbd6ff8f570a3"
 
 [[package]]
 name = "smallvec"
-version = "1.4.2"
+version = "1.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fbee7696b84bbf3d89a1c2eccff0850e3047ed46bfcd2e92c29a2d074d57e252"
+checksum = "fe0f37c9e8f3c5a4a66ad655a93c74daac4ad00c441533bf5c6e7990bb42604e"
 
 [[package]]
 name = "syn"
-version = "1.0.48"
+version = "1.0.58"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cc371affeffc477f42a221a1e4297aedcea33d47d19b61455588bd9d8f6b19ac"
+checksum = "cc60a3d73ea6594cd712d830cc1f0390fd71542d8c8cd24e70cc54cdfd5e05d5"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -385,18 +386,18 @@ checksum = "4ee5a98e506fb7231a304c3a1bd7c132a55016cf65001e0282480665870dfcb9"
 
 [[package]]
 name = "thiserror"
-version = "1.0.22"
+version = "1.0.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0e9ae34b84616eedaaf1e9dd6026dbe00dcafa92aa0c8077cb69df1fcfe5e53e"
+checksum = "76cc616c6abf8c8928e2fdcc0dbfab37175edd8fb49a4641066ad1364fdab146"
 dependencies = [
  "thiserror-impl",
 ]
 
 [[package]]
 name = "thiserror-impl"
-version = "1.0.22"
+version = "1.0.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9ba20f23e85b10754cd195504aebf6a27e2e6cbe28c17778a0c930724628dd56"
+checksum = "9be73a2caec27583d0046ef3796c3794f868a5bc813db689eed00c7631275cd1"
 dependencies = [
  "proc-macro2",
  "quote",

compiler/rustc_codegen_cranelift/Cargo.toml

@@ -9,7 +9,7 @@ crate-type = ["dylib"]
 
 [dependencies]
 # These have to be in sync with each other
-cranelift-codegen = { git = "https://github.com/bytecodealliance/wasmtime/", branch = "main", features = ["unwind"] }
+cranelift-codegen = { git = "https://github.com/bytecodealliance/wasmtime/", branch = "main", features = ["unwind", "x86", "x64"] }
 cranelift-frontend = { git = "https://github.com/bytecodealliance/wasmtime/", branch = "main" }
 cranelift-module = { git = "https://github.com/bytecodealliance/wasmtime/", branch = "main" }
 cranelift-jit = { git = "https://github.com/bytecodealliance/wasmtime/", branch = "main", optional = true }
@@ -21,6 +21,7 @@ object = { version = "0.22.0", default-features = false, features = ["std", "rea
 ar = { git = "https://github.com/bjorn3/rust-ar.git", branch = "do_not_remove_cg_clif_ranlib" }
 indexmap = "1.0.2"
 libloading = { version = "0.6.0", optional = true }
+smallvec = "1.6.1"
 
 # Uncomment to use local checkout of cranelift
 #[patch."https://github.com/bytecodealliance/wasmtime/"]
@@ -37,6 +38,7 @@ libloading = { version = "0.6.0", optional = true }
 default = ["jit", "inline_asm"]
 jit = ["cranelift-jit", "libloading"]
 inline_asm = []
+oldbe = []
 
 [profile.dev]
 # By compiling dependencies with optimizations, performing tests gets much faster.

compiler/rustc_codegen_cranelift/Readme.md

@@ -1,6 +1,4 @@
-# WIP Cranelift codegen backend for rust
+# Cranelift codegen backend for rust
-
-> ⚠⚠⚠ Certain kinds of FFI don't work yet. ⚠⚠⚠
 
 The goal of this project is to create an alternative codegen backend for the rust compiler based on [Cranelift](https://github.com/bytecodealliance/wasmtime/blob/main/cranelift).
 This has the potential to improve compilation times in debug mode.
@@ -103,8 +101,7 @@ function jit_calc() {
 
 ## Not yet supported
 
-* Good non-rust abi support ([several problems](https://github.com/bjorn3/rustc_codegen_cranelift/issues/10))
+* Inline assembly ([no cranelift support](https://github.com/bytecodealliance/wasmtime/issues/1041))
-* Inline assembly ([no cranelift support](https://github.com/bytecodealliance/wasmtime/issues/1041)
     * On Linux there is support for invoking an external assembler for `global_asm!` and `asm!`.
       `llvm_asm!` will remain unimplemented forever. `asm!` doesn't yet support reg classes. You
       have to specify specific registers instead.

compiler/rustc_codegen_cranelift/build.sh

@@ -3,23 +3,29 @@ set -e
 
 # Settings
 export CHANNEL="release"
-build_sysroot=1
+build_sysroot="clif"
 target_dir='build'
+oldbe=''
 while [[ $# != 0 ]]; do
     case $1 in
         "--debug")
             export CHANNEL="debug"
             ;;
-        "--without-sysroot")
+        "--sysroot")
-            build_sysroot=0
+            build_sysroot=$2
+            shift
             ;;
         "--target-dir")
             target_dir=$2
             shift
             ;;
+        "--oldbe")
+            oldbe='--features oldbe'
+            ;;
         *)
             echo "Unknown flag '$1'"
-            echo "Usage: ./build.sh [--debug] [--without-sysroot] [--target-dir DIR]"
+            echo "Usage: ./build.sh [--debug] [--sysroot none|clif|llvm] [--target-dir DIR] [--oldbe]"
+            exit 1
             ;;
     esac
     shift
@@ -27,23 +33,24 @@ done
 
 # Build cg_clif
 unset CARGO_TARGET_DIR
-export RUSTFLAGS="-Zrun_dsymutil=no"
 unamestr=$(uname)
 if [[ "$unamestr" == 'Linux' ]]; then
    export RUSTFLAGS='-Clink-arg=-Wl,-rpath=$ORIGIN/../lib '$RUSTFLAGS
 elif [[ "$unamestr" == 'Darwin' ]]; then
-   export RUSTFLAGS='-Clink-arg=-Wl,-rpath,@loader_path/../lib -Zosx-rpath-install-name '$RUSTFLAGS
+   export RUSTFLAGS='-Csplit-debuginfo=unpacked -Clink-arg=-Wl,-rpath,@loader_path/../lib -Zosx-rpath-install-name '$RUSTFLAGS
    dylib_ext='dylib'
 else
    echo "Unsupported os"
    exit 1
 fi
 if [[ "$CHANNEL" == "release" ]]; then
-    cargo build --release
+    cargo build $oldbe --release
 else
-    cargo build
+    cargo build $oldbe
 fi
 
+source scripts/ext_config.sh
+
 rm -rf "$target_dir"
 mkdir "$target_dir"
 mkdir "$target_dir"/bin "$target_dir"/lib
@@ -51,10 +58,29 @@ ln target/$CHANNEL/cg_clif{,_build_sysroot} "$target_dir"/bin
 ln target/$CHANNEL/*rustc_codegen_cranelift* "$target_dir"/lib
 ln rust-toolchain scripts/config.sh scripts/cargo.sh "$target_dir"
 
-if [[ "$build_sysroot" == "1" ]]; then
+mkdir -p "$target_dir/lib/rustlib/$TARGET_TRIPLE/lib/"
-    echo "[BUILD] sysroot"
+if [[ "$TARGET_TRIPLE" == "x86_64-pc-windows-gnu" ]]; then
-    export CG_CLIF_INCR_CACHE_DISABLED=1
+    cp $(rustc --print sysroot)/lib/rustlib/$TARGET_TRIPLE/lib/*.o "$target_dir/lib/rustlib/$TARGET_TRIPLE/lib/"
-    dir=$(pwd)
-    cd "$target_dir"
-    time "$dir/build_sysroot/build_sysroot.sh"
 fi
+
+case "$build_sysroot" in
+    "none")
+        ;;
+    "llvm")
+        cp -r $(rustc --print sysroot)/lib/rustlib/$TARGET_TRIPLE/lib "$target_dir/lib/rustlib/$TARGET_TRIPLE/"
+        ;;
+    "clif")
+        echo "[BUILD] sysroot"
+        dir=$(pwd)
+        cd "$target_dir"
+        time "$dir/build_sysroot/build_sysroot.sh"
+        cp lib/rustlib/*/lib/libstd-* lib/
+        ;;
+    *)
+        echo "Unknown sysroot kind \`$build_sysroot\`."
+        echo "The allowed values are:"
+        echo "    none A sysroot that doesn't contain the standard library"
+        echo "    llvm Copy the sysroot from rustc compiled by cg_llvm"
+        echo "    clif Build a new sysroot using cg_clif"
+        exit 1
+esac

compiler/rustc_codegen_cranelift/build_sysroot/Cargo.lock

@@ -2,9 +2,9 @@
 # It is not intended for manual editing.
 [[package]]
 name = "addr2line"
-version = "0.14.0"
+version = "0.14.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7c0929d69e78dd9bf5408269919fcbcaeb2e35e5d43e5815517cdc6a8e11a423"
+checksum = "a55f82cfe485775d02112886f4169bde0c5894d75e79ead7eafe7e40a25e45f7"
 dependencies = [
  "compiler_builtins",
  "gimli",
@@ -63,9 +63,7 @@ dependencies = [
 
 [[package]]
 name = "compiler_builtins"
-version = "0.1.36"
+version = "0.1.39"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7cd0782e0a7da7598164153173e5a5d4d9b1da094473c98dce0ff91406112369"
 dependencies = [
  "rustc-std-workspace-core",
 ]
@@ -130,9 +128,9 @@ dependencies = [
 
 [[package]]
 name = "hermit-abi"
-version = "0.1.17"
+version = "0.1.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5aca5565f760fb5b220e499d72710ed156fdb74e631659e99377d9ebfbd13ae8"
+checksum = "322f4de77956e22ed0e5032c359a0f1273f1f7f0d79bfa3b8ffbc730d7fbcc5c"
 dependencies = [
  "compiler_builtins",
  "libc",
@@ -141,9 +139,9 @@ dependencies = [
 
 [[package]]
 name = "libc"
-version = "0.2.81"
+version = "0.2.84"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1482821306169ec4d07f6aca392a4681f66c75c9918aa49641a2595db64053cb"
+checksum = "1cca32fa0182e8c0989459524dc356b8f2b5c10f1b9eb521b7d182c03cf8c5ff"
 dependencies = [
  "rustc-std-workspace-core",
 ]

compiler/rustc_codegen_cranelift/build_sysroot/Cargo.toml

@@ -11,12 +11,13 @@ test = { path = "./sysroot_src/library/test" }
 
 alloc_system = { path = "./alloc_system" }
 
-compiler_builtins = { version = "=0.1.36", default-features = false }
+compiler_builtins = { version = "0.1.39", default-features = false, features = ["no-asm"] }
 
 [patch.crates-io]
 rustc-std-workspace-core = { path = "./sysroot_src/library/rustc-std-workspace-core" }
 rustc-std-workspace-alloc = { path = "./sysroot_src/library/rustc-std-workspace-alloc" }
 rustc-std-workspace-std = { path = "./sysroot_src/library/rustc-std-workspace-std" }
+compiler_builtins = { path = "./compiler-builtins" }
 
 [profile.dev]
 lto = "off"

compiler/rustc_codegen_cranelift/build_sysroot/build_sysroot.sh

@@ -24,17 +24,16 @@ export CARGO_TARGET_DIR=target
 
 # Build libs
 export RUSTFLAGS="$RUSTFLAGS -Zforce-unstable-if-unmarked -Cpanic=abort"
+export __CARGO_DEFAULT_LIB_METADATA="cg_clif"
 if [[ "$1" != "--debug" ]]; then
     sysroot_channel='release'
     # FIXME Enable incremental again once rust-lang/rust#74946 is fixed
-    # FIXME Enable -Zmir-opt-level=2 again once it doesn't ice anymore
+    CARGO_INCREMENTAL=0 RUSTFLAGS="$RUSTFLAGS -Zmir-opt-level=2" cargo build --target "$TARGET_TRIPLE" --release
-    CARGO_INCREMENTAL=0 RUSTFLAGS="$RUSTFLAGS" cargo build --target "$TARGET_TRIPLE" --release
 else
     sysroot_channel='debug'
     cargo build --target "$TARGET_TRIPLE"
 fi
 
 # Copy files to sysroot
-mkdir -p "$dir/lib/rustlib/$TARGET_TRIPLE/lib/"
 ln "target/$TARGET_TRIPLE/$sysroot_channel/deps/"* "$dir/lib/rustlib/$TARGET_TRIPLE/lib/"
 rm "$dir/lib/rustlib/$TARGET_TRIPLE/lib/"*.{rmeta,d}

compiler/rustc_codegen_cranelift/build_sysroot/prepare_sysroot_src.sh

@@ -29,4 +29,11 @@ git commit --no-gpg-sign -m "Patch $file"
 done
 popd
 
-echo "Successfully prepared libcore for building"
+git clone https://github.com/rust-lang/compiler-builtins.git || echo "rust-lang/compiler-builtins has already been cloned"
+pushd compiler-builtins
+git checkout -- .
+git checkout 0.1.39
+git apply ../../crate_patches/0001-compiler-builtins-Remove-rotate_left-from-Int.patch
+popd
+
+echo "Successfully prepared sysroot source for building"

compiler/rustc_codegen_cranelift/clean_all.sh

@@ -1,5 +1,5 @@
 #!/bin/bash --verbose
 set -e
 
-rm -rf target/ build/ build_sysroot/{sysroot_src/,target/} perf.data{,.old}
+rm -rf target/ build/ build_sysroot/{sysroot_src/,target/,compiler-builtins/} perf.data{,.old}
 rm -rf rand/ regex/ simple-raytracer/

compiler/rustc_codegen_cranelift/crate_patches/0001-compiler-builtins-Remove-rotate_left-from-Int.patch

@@ -0,0 +1,35 @@
+From 7078cca3cb614e1e82da428380b4e16fc3afef46 Mon Sep 17 00:00:00 2001
+From: bjorn3 <bjorn3@users.noreply.github.com>
+Date: Thu, 21 Jan 2021 14:46:36 +0100
+Subject: [PATCH] Remove rotate_left from Int
+
+---
+ src/int/mod.rs | 5 -----
+ 1 file changed, 5 deletions(-)
+
+diff --git a/src/int/mod.rs b/src/int/mod.rs
+index 06054c8..3bea17b 100644
+--- a/src/int/mod.rs
++++ b/src/int/mod.rs
+@@ -85,7 +85,6 @@ pub trait Int:
+     fn wrapping_sub(self, other: Self) -> Self;
+     fn wrapping_shl(self, other: u32) -> Self;
+     fn wrapping_shr(self, other: u32) -> Self;
+-    fn rotate_left(self, other: u32) -> Self;
+     fn overflowing_add(self, other: Self) -> (Self, bool);
+     fn aborting_div(self, other: Self) -> Self;
+     fn aborting_rem(self, other: Self) -> Self;
+@@ -209,10 +208,6 @@ macro_rules! int_impl_common {
+             <Self>::wrapping_shr(self, other)
+         }
+ 
+-        fn rotate_left(self, other: u32) -> Self {
+-            <Self>::rotate_left(self, other)
+-        }
+-
+         fn overflowing_add(self, other: Self) -> (Self, bool) {
+             <Self>::overflowing_add(self, other)
+         }
+-- 
+2.26.2.7.g19db9cfb68
+

compiler/rustc_codegen_cranelift/example/alloc_example.rs

@@ -11,7 +11,8 @@ use alloc_system::System;
 #[global_allocator]
 static ALLOC: System = System;
 
-#[link(name = "c")]
+#[cfg_attr(unix, link(name = "c"))]
+#[cfg_attr(target_env = "msvc", link(name = "msvcrt"))]
 extern "C" {
     fn puts(s: *const u8) -> i32;
 }

compiler/rustc_codegen_cranelift/example/mini_core.rs

@@ -532,8 +532,8 @@ pub mod intrinsics {
 }
 
 pub mod libc {
-    #[cfg_attr(not(windows), link(name = "c"))]
+    #[cfg_attr(unix, link(name = "c"))]
-    #[cfg_attr(windows, link(name = "msvcrt"))]
+    #[cfg_attr(target_env = "msvc", link(name = "msvcrt"))]
     extern "C" {
         pub fn puts(s: *const i8) -> i32;
         pub fn printf(format: *const i8, ...) -> i32;

compiler/rustc_codegen_cranelift/example/mod_bench.rs

@@ -1,7 +1,8 @@
 #![feature(start, box_syntax, core_intrinsics, lang_items)]
 #![no_std]
 
-#[link(name = "c")]
+#[cfg_attr(unix, link(name = "c"))]
+#[cfg_attr(target_env = "msvc", link(name = "msvcrt"))]
 extern {}
 
 #[panic_handler]

compiler/rustc_codegen_cranelift/patches/0022-core-Disable-not-compiling-tests.patch

@@ -119,5 +119,21 @@ index 6609bc3..241b497 100644
  
  #[test]
  #[should_panic(expected = "index 0 greater than length of slice")]
+diff --git a/library/core/tests/num/ops.rs b/library/core/tests/num/ops.rs
+index 9979cc8..d5d1d83 100644
+--- a/library/core/tests/num/ops.rs
++++ b/library/core/tests/num/ops.rs
+@@ -238,7 +238,7 @@ macro_rules! test_shift_assign {
+         }
+     };
+ }
+-test_shift!(test_shl_defined, Shl::shl);
+-test_shift_assign!(test_shl_assign_defined, ShlAssign::shl_assign);
+-test_shift!(test_shr_defined, Shr::shr);
+-test_shift_assign!(test_shr_assign_defined, ShrAssign::shr_assign);
++//test_shift!(test_shl_defined, Shl::shl);
++//test_shift_assign!(test_shl_assign_defined, ShlAssign::shl_assign);
++//test_shift!(test_shr_defined, Shr::shr);
++//test_shift_assign!(test_shr_assign_defined, ShrAssign::shr_assign);
 --
 2.21.0 (Apple Git-122)

compiler/rustc_codegen_cranelift/rust-toolchain

@@ -1 +1 @@
-nightly-2020-12-23
+nightly-2021-01-30

compiler/rustc_codegen_cranelift/scripts/config.sh

@@ -12,28 +12,6 @@ else
    exit 1
 fi
 
-HOST_TRIPLE=$(rustc -vV | grep host | cut -d: -f2 | tr -d " ")
-TARGET_TRIPLE=$HOST_TRIPLE
-#TARGET_TRIPLE="x86_64-pc-windows-gnu"
-#TARGET_TRIPLE="aarch64-unknown-linux-gnu"
-
-linker=''
-RUN_WRAPPER=''
-export JIT_SUPPORTED=1
-if [[ "$HOST_TRIPLE" != "$TARGET_TRIPLE" ]]; then
-   export JIT_SUPPORTED=0
-   if [[ "$TARGET_TRIPLE" == "aarch64-unknown-linux-gnu" ]]; then
-      # We are cross-compiling for aarch64. Use the correct linker and run tests in qemu.
-      linker='-Clinker=aarch64-linux-gnu-gcc'
-      RUN_WRAPPER='qemu-aarch64 -L /usr/aarch64-linux-gnu'
-   elif [[ "$TARGET_TRIPLE" == "x86_64-pc-windows-gnu" ]]; then
-      # We are cross-compiling for Windows. Run tests in wine.
-      RUN_WRAPPER='wine'
-   else
-      echo "Unknown non-native platform"
-   fi
-fi
-
 if echo "$RUSTC_WRAPPER" | grep sccache; then
 echo
 echo -e "\x1b[1;93m=== Warning: Unset RUSTC_WRAPPER to prevent interference with sccache ===\x1b[0m"
@@ -44,16 +22,14 @@ fi
 dir=$(cd "$(dirname "${BASH_SOURCE[0]}")"; pwd)
 
 export RUSTC=$dir"/bin/cg_clif"
-export RUSTFLAGS=$linker" "$RUSTFLAGS
+
 export RUSTDOCFLAGS=$linker' -Cpanic=abort -Zpanic-abort-tests '\
 '-Zcodegen-backend='$dir'/lib/librustc_codegen_cranelift.'$dylib_ext' --sysroot '$dir
 
 # FIXME remove once the atomic shim is gone
-if [[ $(uname) == 'Darwin' ]]; then
+if [[ "$unamestr" == 'Darwin' ]]; then
    export RUSTFLAGS="$RUSTFLAGS -Clink-arg=-undefined -Clink-arg=dynamic_lookup"
 fi
 
-export LD_LIBRARY_PATH="$(rustc --print sysroot)/lib"
+export LD_LIBRARY_PATH="$(rustc --print sysroot)/lib:"$dir"/lib"
 export DYLD_LIBRARY_PATH=$LD_LIBRARY_PATH
-
-export CG_CLIF_DISPLAY_CG_TIME=1

compiler/rustc_codegen_cranelift/scripts/ext_config.sh

@@ -0,0 +1,27 @@
+# Note to people running shellcheck: this file should only be sourced, not executed directly.
+
+# Various env vars that should only be set for the build system but not for cargo.sh
+
+set -e
+
+export CG_CLIF_DISPLAY_CG_TIME=1
+export CG_CLIF_INCR_CACHE_DISABLED=1
+
+export HOST_TRIPLE=$(rustc -vV | grep host | cut -d: -f2 | tr -d " ")
+export TARGET_TRIPLE=${TARGET_TRIPLE:-$HOST_TRIPLE}
+
+export RUN_WRAPPER=''
+export JIT_SUPPORTED=1
+if [[ "$HOST_TRIPLE" != "$TARGET_TRIPLE" ]]; then
+   export JIT_SUPPORTED=0
+   if [[ "$TARGET_TRIPLE" == "aarch64-unknown-linux-gnu" ]]; then
+      # We are cross-compiling for aarch64. Use the correct linker and run tests in qemu.
+      export RUSTFLAGS='-Clinker=aarch64-linux-gnu-gcc '$RUSTFLAGS
+      export RUN_WRAPPER='qemu-aarch64 -L /usr/aarch64-linux-gnu'
+   elif [[ "$TARGET_TRIPLE" == "x86_64-pc-windows-gnu" ]]; then
+      # We are cross-compiling for Windows. Run tests in wine.
+      export RUN_WRAPPER='wine'
+   else
+      echo "Unknown non-native platform"
+   fi
+fi

compiler/rustc_codegen_cranelift/scripts/tests.sh

@@ -3,7 +3,7 @@
 set -e
 
 source build/config.sh
-export CG_CLIF_INCR_CACHE_DISABLED=1
+source scripts/ext_config.sh
 MY_RUSTC="$RUSTC $RUSTFLAGS -L crate=target/out --out-dir target/out -Cdebuginfo=2"
 
 function no_sysroot_tests() {

compiler/rustc_codegen_cranelift/src/abi/comments.rs

@@ -4,10 +4,10 @@
 use std::borrow::Cow;
 
 use rustc_middle::mir;
+use rustc_target::abi::call::PassMode;
 
 use cranelift_codegen::entity::EntityRef;
 
-use crate::abi::pass_mode::*;
 use crate::prelude::*;
 
 pub(super) fn add_args_header_comment(fx: &mut FunctionCx<'_, '_, impl Module>) {
@@ -21,9 +21,9 @@ pub(super) fn add_arg_comment<'tcx>(
     kind: &str,
     local: Option<mir::Local>,
     local_field: Option<usize>,
-    params: EmptySinglePair<Value>,
+    params: &[Value],
-    pass_mode: PassMode,
+    arg_abi_mode: PassMode,
-    ty: Ty<'tcx>,
+    arg_layout: TyAndLayout<'tcx>,
 ) {
     let local = if let Some(local) = local {
         Cow::Owned(format!("{:?}", local))
@@ -37,12 +37,20 @@ pub(super) fn add_arg_comment<'tcx>(
     };
 
     let params = match params {
-        Empty => Cow::Borrowed("-"),
+        [] => Cow::Borrowed("-"),
-        Single(param) => Cow::Owned(format!("= {:?}", param)),
+        [param] => Cow::Owned(format!("= {:?}", param)),
-        Pair(param_a, param_b) => Cow::Owned(format!("= {:?}, {:?}", param_a, param_b)),
+        [param_a, param_b] => Cow::Owned(format!("= {:?},{:?}", param_a, param_b)),
+        params => Cow::Owned(format!(
+            "= {}",
+            params
+                .iter()
+                .map(ToString::to_string)
+                .collect::<Vec<_>>()
+                .join(",")
+        )),
     };
 
-    let pass_mode = format!("{:?}", pass_mode);
+    let pass_mode = format!("{:?}", arg_abi_mode);
     fx.add_global_comment(format!(
         "{kind:5}{local:>3}{local_field:<5} {params:10} {pass_mode:36} {ty:?}",
         kind = kind,
@@ -50,7 +58,7 @@ pub(super) fn add_arg_comment<'tcx>(
         local_field = local_field,
         params = params,
         pass_mode = pass_mode,
-        ty = ty,
+        ty = arg_layout.ty,
     ));
 }
 

compiler/rustc_codegen_cranelift/src/abi/mod.rs

@@ -6,199 +6,50 @@ mod pass_mode;
 mod returning;
 
 use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrFlags;
+use rustc_middle::ty::layout::FnAbiExt;
+use rustc_target::abi::call::{Conv, FnAbi};
 use rustc_target::spec::abi::Abi;
 
-use cranelift_codegen::ir::{AbiParam, ArgumentPurpose};
+use cranelift_codegen::ir::AbiParam;
+use smallvec::smallvec;
 
 use self::pass_mode::*;
 use crate::prelude::*;
 
 pub(crate) use self::returning::{can_return_to_ssa_var, codegen_return};
 
-// Copied from https://github.com/rust-lang/rust/blob/f52c72948aa1dd718cc1f168d21c91c584c0a662/src/librustc_middle/ty/layout.rs#L2301
+fn clif_sig_from_fn_abi<'tcx>(
-#[rustfmt::skip]
-pub(crate) fn fn_sig_for_fn_abi<'tcx>(tcx: TyCtxt<'tcx>, instance: Instance<'tcx>) -> ty::PolyFnSig<'tcx> {
-    use rustc_middle::ty::subst::Subst;
-
-    // FIXME(davidtwco,eddyb): A `ParamEnv` should be passed through to this function.
-    let ty = instance.ty(tcx, ty::ParamEnv::reveal_all());
-    match *ty.kind() {
-        ty::FnDef(..) => {
-            // HACK(davidtwco,eddyb): This is a workaround for polymorphization considering
-            // parameters unused if they show up in the signature, but not in the `mir::Body`
-            // (i.e. due to being inside a projection that got normalized, see
-            // `src/test/ui/polymorphization/normalized_sig_types.rs`), and codegen not keeping
-            // track of a polymorphization `ParamEnv` to allow normalizing later.
-            let mut sig = match *ty.kind() {
-                ty::FnDef(def_id, substs) => tcx
-                    .normalize_erasing_regions(tcx.param_env(def_id), tcx.fn_sig(def_id))
-                    .subst(tcx, substs),
-                _ => unreachable!(),
-            };
-
-            if let ty::InstanceDef::VtableShim(..) = instance.def {
-                // Modify `fn(self, ...)` to `fn(self: *mut Self, ...)`.
-                sig = sig.map_bound(|mut sig| {
-                    let mut inputs_and_output = sig.inputs_and_output.to_vec();
-                    inputs_and_output[0] = tcx.mk_mut_ptr(inputs_and_output[0]);
-                    sig.inputs_and_output = tcx.intern_type_list(&inputs_and_output);
-                    sig
-                });
-            }
-            sig
-        }
-        ty::Closure(def_id, substs) => {
-            let sig = substs.as_closure().sig();
-
-            let env_ty = tcx.closure_env_ty(def_id, substs).unwrap();
-            sig.map_bound(|sig| {
-                tcx.mk_fn_sig(
-                    std::iter::once(env_ty.skip_binder()).chain(sig.inputs().iter().cloned()),
-                    sig.output(),
-                    sig.c_variadic,
-                    sig.unsafety,
-                    sig.abi,
-                )
-            })
-        }
-        ty::Generator(_, substs, _) => {
-            let sig = substs.as_generator().poly_sig();
-
-            let env_region = ty::ReLateBound(ty::INNERMOST, ty::BoundRegion { kind: ty::BrEnv });
-            let env_ty = tcx.mk_mut_ref(tcx.mk_region(env_region), ty);
-
-            let pin_did = tcx.require_lang_item(rustc_hir::LangItem::Pin, None);
-            let pin_adt_ref = tcx.adt_def(pin_did);
-            let pin_substs = tcx.intern_substs(&[env_ty.into()]);
-            let env_ty = tcx.mk_adt(pin_adt_ref, pin_substs);
-
-            sig.map_bound(|sig| {
-                let state_did = tcx.require_lang_item(rustc_hir::LangItem::GeneratorState, None);
-                let state_adt_ref = tcx.adt_def(state_did);
-                let state_substs =
-                    tcx.intern_substs(&[sig.yield_ty.into(), sig.return_ty.into()]);
-                let ret_ty = tcx.mk_adt(state_adt_ref, state_substs);
-
-                tcx.mk_fn_sig(
-                    [env_ty, sig.resume_ty].iter(),
-                    &ret_ty,
-                    false,
-                    rustc_hir::Unsafety::Normal,
-                    rustc_target::spec::abi::Abi::Rust,
-                )
-            })
-        }
-        _ => bug!("unexpected type {:?} in Instance::fn_sig", ty),
-    }
-}
-
-fn clif_sig_from_fn_sig<'tcx>(
     tcx: TyCtxt<'tcx>,
     triple: &target_lexicon::Triple,
-    sig: FnSig<'tcx>,
+    fn_abi: &FnAbi<'tcx, Ty<'tcx>>,
-    span: Span,
-    is_vtable_fn: bool,
-    requires_caller_location: bool,
 ) -> Signature {
-    let abi = match sig.abi {
+    let call_conv = match fn_abi.conv {
-        Abi::System => Abi::C,
+        Conv::Rust | Conv::C => CallConv::triple_default(triple),
-        abi => abi,
+        Conv::X86_64SysV => CallConv::SystemV,
-    };
+        Conv::X86_64Win64 => CallConv::WindowsFastcall,
-    let (call_conv, inputs, output): (CallConv, Vec<Ty<'tcx>>, Ty<'tcx>) = match abi {
+        Conv::ArmAapcs
-        Abi::Rust => (
+        | Conv::Msp430Intr
-            CallConv::triple_default(triple),
+        | Conv::PtxKernel
-            sig.inputs().to_vec(),
+        | Conv::X86Fastcall
-            sig.output(),
+        | Conv::X86Intr
-        ),
+        | Conv::X86Stdcall
-        Abi::C | Abi::Unadjusted => (
+        | Conv::X86ThisCall
-            CallConv::triple_default(triple),
+        | Conv::X86VectorCall
-            sig.inputs().to_vec(),
+        | Conv::AmdGpuKernel
-            sig.output(),
+        | Conv::AvrInterrupt
-        ),
+        | Conv::AvrNonBlockingInterrupt => {
-        Abi::SysV64 => (CallConv::SystemV, sig.inputs().to_vec(), sig.output()),
+            todo!("{:?}", fn_abi.conv)
-        Abi::RustCall => {
-            assert_eq!(sig.inputs().len(), 2);
-            let extra_args = match sig.inputs().last().unwrap().kind() {
-                ty::Tuple(ref tupled_arguments) => tupled_arguments,
-                _ => bug!("argument to function with \"rust-call\" ABI is not a tuple"),
-            };
-            let mut inputs: Vec<Ty<'tcx>> = vec![sig.inputs()[0]];
-            inputs.extend(extra_args.types());
-            (CallConv::triple_default(triple), inputs, sig.output())
         }
-        Abi::System => unreachable!(),
-        Abi::RustIntrinsic => (
-            CallConv::triple_default(triple),
-            sig.inputs().to_vec(),
-            sig.output(),
-        ),
-        _ => unimplemented!("unsupported abi {:?}", sig.abi),
     };
-
+    let inputs = fn_abi
-    let inputs = inputs
+        .args
-        .into_iter()
+        .iter()
-        .enumerate()
+        .map(|arg_abi| arg_abi.get_abi_param(tcx).into_iter())
-        .map(|(i, ty)| {
-            let mut layout = tcx.layout_of(ParamEnv::reveal_all().and(ty)).unwrap();
-            if i == 0 && is_vtable_fn {
-                // Virtual calls turn their self param into a thin pointer.
-                // See https://github.com/rust-lang/rust/blob/37b6a5e5e82497caf5353d9d856e4eb5d14cbe06/src/librustc/ty/layout.rs#L2519-L2572 for more info
-                layout = tcx
-                    .layout_of(ParamEnv::reveal_all().and(tcx.mk_mut_ptr(tcx.mk_unit())))
-                    .unwrap();
-            }
-            let pass_mode = get_pass_mode(tcx, layout);
-            if abi != Abi::Rust && abi != Abi::RustCall && abi != Abi::RustIntrinsic {
-                match pass_mode {
-                    PassMode::NoPass | PassMode::ByVal(_) => {}
-                    PassMode::ByRef { size: Some(size) } => {
-                        let purpose = ArgumentPurpose::StructArgument(u32::try_from(size.bytes()).expect("struct too big to pass on stack"));
-                        return EmptySinglePair::Single(AbiParam::special(pointer_ty(tcx), purpose)).into_iter();
-                    }
-                    PassMode::ByValPair(_, _) | PassMode::ByRef { size: None } => {
-                        tcx.sess.span_warn(
-                            span,
-                            &format!(
-                                "Argument of type `{:?}` with pass mode `{:?}` is not yet supported \
-                                for non-rust abi `{}`. Calling this function may result in a crash.",
-                                layout.ty,
-                                pass_mode,
-                                abi,
-                            ),
-                        );
-                    }
-                }
-            }
-            pass_mode.get_param_ty(tcx).map(AbiParam::new).into_iter()
-        })
         .flatten();
 
-    let (mut params, returns): (Vec<_>, Vec<_>) = match get_pass_mode(
+    let (return_ptr, returns) = fn_abi.ret.get_abi_return(tcx);
-        tcx,
+    // Sometimes the first param is an pointer to the place where the return value needs to be stored.
-        tcx.layout_of(ParamEnv::reveal_all().and(output)).unwrap(),
+    let params: Vec<_> = return_ptr.into_iter().chain(inputs).collect();
-    ) {
-        PassMode::NoPass => (inputs.collect(), vec![]),
-        PassMode::ByVal(ret_ty) => (inputs.collect(), vec![AbiParam::new(ret_ty)]),
-        PassMode::ByValPair(ret_ty_a, ret_ty_b) => (
-            inputs.collect(),
-            vec![AbiParam::new(ret_ty_a), AbiParam::new(ret_ty_b)],
-        ),
-        PassMode::ByRef { size: Some(_) } => {
-            (
-                Some(pointer_ty(tcx)) // First param is place to put return val
-                    .into_iter()
-                    .map(|ty| AbiParam::special(ty, ArgumentPurpose::StructReturn))
-                    .chain(inputs)
-                    .collect(),
-                vec![],
-            )
-        }
-        PassMode::ByRef { size: None } => todo!(),
-    };
-
-    if requires_caller_location {
-        params.push(AbiParam::new(pointer_ty(tcx)));
-    }
 
     Signature {
         params,
@@ -207,30 +58,17 @@ fn clif_sig_from_fn_sig<'tcx>(
     }
 }
 
-pub(crate) fn get_function_name_and_sig<'tcx>(
+pub(crate) fn get_function_sig<'tcx>(
     tcx: TyCtxt<'tcx>,
     triple: &target_lexicon::Triple,
     inst: Instance<'tcx>,
-    support_vararg: bool,
+) -> Signature {
-) -> (String, Signature) {
     assert!(!inst.substs.needs_infer());
-    let fn_sig = tcx
+    clif_sig_from_fn_abi(
-        .normalize_erasing_late_bound_regions(ParamEnv::reveal_all(), fn_sig_for_fn_abi(tcx, inst));
-    if fn_sig.c_variadic && !support_vararg {
-        tcx.sess.span_fatal(
-            tcx.def_span(inst.def_id()),
-            "Variadic function definitions are not yet supported",
-        );
-    }
-    let sig = clif_sig_from_fn_sig(
         tcx,
         triple,
-        fn_sig,
+        &FnAbi::of_instance(&RevealAllLayoutCx(tcx), inst, &[]),
-        tcx.def_span(inst.def_id()),
+    )
-        false,
-        inst.def.requires_caller_location(tcx),
-    );
-    (tcx.symbol_name(inst).name.to_string(), sig)
 }
 
 /// Instance must be monomorphized
@@ -239,7 +77,8 @@ pub(crate) fn import_function<'tcx>(
     module: &mut impl Module,
     inst: Instance<'tcx>,
 ) -> FuncId {
-    let (name, sig) = get_function_name_and_sig(tcx, module.isa().triple(), inst, true);
+    let name = tcx.symbol_name(inst).name.to_string();
+    let sig = get_function_sig(tcx, module.isa().triple(), inst);
     module
         .declare_function(&name, Linkage::Import, &sig)
         .unwrap()
@@ -263,13 +102,13 @@ impl<'tcx, M: Module> FunctionCx<'_, 'tcx, M> {
     pub(crate) fn lib_call(
         &mut self,
         name: &str,
-        input_tys: Vec<types::Type>,
+        params: Vec<AbiParam>,
-        output_tys: Vec<types::Type>,
+        returns: Vec<AbiParam>,
         args: &[Value],
     ) -> &[Value] {
         let sig = Signature {
-            params: input_tys.iter().cloned().map(AbiParam::new).collect(),
+            params,
-            returns: output_tys.iter().cloned().map(AbiParam::new).collect(),
+            returns,
             call_conv: CallConv::triple_default(self.triple()),
         };
         let func_id = self
@@ -301,16 +140,18 @@ impl<'tcx, M: Module> FunctionCx<'_, 'tcx, M> {
             .iter()
             .map(|arg| {
                 (
-                    self.clif_type(arg.layout().ty).unwrap(),
+                    AbiParam::new(self.clif_type(arg.layout().ty).unwrap()),
                     arg.load_scalar(self),
                 )
             })
             .unzip();
         let return_layout = self.layout_of(return_ty);
         let return_tys = if let ty::Tuple(tup) = return_ty.kind() {
-            tup.types().map(|ty| self.clif_type(ty).unwrap()).collect()
+            tup.types()
+                .map(|ty| AbiParam::new(self.clif_type(ty).unwrap()))
+                .collect()
         } else {
-            vec![self.clif_type(return_ty).unwrap()]
+            vec![AbiParam::new(self.clif_type(return_ty).unwrap())]
         };
         let ret_vals = self.lib_call(name, input_tys, return_tys, &args);
         match *ret_vals {
@@ -352,12 +193,25 @@ pub(crate) fn codegen_fn_prelude<'tcx>(
     fx: &mut FunctionCx<'_, 'tcx, impl Module>,
     start_block: Block,
 ) {
+    fx.bcx.append_block_params_for_function_params(start_block);
+
+    fx.bcx.switch_to_block(start_block);
+    fx.bcx.ins().nop();
+
     let ssa_analyzed = crate::analyze::analyze(fx);
 
     #[cfg(debug_assertions)]
     self::comments::add_args_header_comment(fx);
 
-    let ret_place = self::returning::codegen_return_param(fx, &ssa_analyzed, start_block);
+    let mut block_params_iter = fx
+        .bcx
+        .func
+        .dfg
+        .block_params(start_block)
+        .to_vec()
+        .into_iter();
+    let ret_place =
+        self::returning::codegen_return_param(fx, &ssa_analyzed, &mut block_params_iter);
     assert_eq!(fx.local_map.push(ret_place), RETURN_PLACE);
 
     // None means pass_mode == NoPass
@@ -366,6 +220,9 @@ pub(crate) fn codegen_fn_prelude<'tcx>(
         Spread(Vec<Option<CValue<'tcx>>>),
     }
 
+    let fn_abi = fx.fn_abi.take().unwrap();
+    let mut arg_abis_iter = fn_abi.args.iter();
+
     let func_params = fx
         .mir
         .args_iter()
@@ -385,14 +242,18 @@ pub(crate) fn codegen_fn_prelude<'tcx>(
                 };
 
                 let mut params = Vec::new();
-                for (i, arg_ty) in tupled_arg_tys.types().enumerate() {
+                for (i, _arg_ty) in tupled_arg_tys.types().enumerate() {
-                    let param = cvalue_for_param(fx, start_block, Some(local), Some(i), arg_ty);
+                    let arg_abi = arg_abis_iter.next().unwrap();
+                    let param =
+                        cvalue_for_param(fx, Some(local), Some(i), arg_abi, &mut block_params_iter);
                     params.push(param);
                 }
 
                 (local, ArgKind::Spread(params), arg_ty)
             } else {
-                let param = cvalue_for_param(fx, start_block, Some(local), None, arg_ty);
+                let arg_abi = arg_abis_iter.next().unwrap();
+                let param =
+                    cvalue_for_param(fx, Some(local), None, arg_abi, &mut block_params_iter);
                 (local, ArgKind::Normal(param), arg_ty)
             }
         })
@@ -401,13 +262,14 @@ pub(crate) fn codegen_fn_prelude<'tcx>(
     assert!(fx.caller_location.is_none());
     if fx.instance.def.requires_caller_location(fx.tcx) {
         // Store caller location for `#[track_caller]`.
-        fx.caller_location = Some(
+        let arg_abi = arg_abis_iter.next().unwrap();
-            cvalue_for_param(fx, start_block, None, None, fx.tcx.caller_location_ty()).unwrap(),
+        fx.caller_location =
-        );
+            Some(cvalue_for_param(fx, None, None, arg_abi, &mut block_params_iter).unwrap());
     }
 
-    fx.bcx.switch_to_block(start_block);
+    assert!(arg_abis_iter.next().is_none(), "ArgAbi left behind");
-    fx.bcx.ins().nop();
+    fx.fn_abi = Some(fn_abi);
+    assert!(block_params_iter.next().is_none(), "arg_value left behind");
 
     #[cfg(debug_assertions)]
     self::comments::add_locals_header_comment(fx);
@@ -533,6 +395,21 @@ pub(crate) fn codegen_terminator_call<'tcx>(
         None
     };
 
+    let extra_args = &args[fn_sig.inputs().len()..];
+    let extra_args = extra_args
+        .iter()
+        .map(|op_arg| fx.monomorphize(op_arg.ty(fx.mir, fx.tcx)))
+        .collect::<Vec<_>>();
+    let fn_abi = if let Some(instance) = instance {
+        FnAbi::of_instance(&RevealAllLayoutCx(fx.tcx), instance, &extra_args)
+    } else {
+        FnAbi::of_fn_ptr(
+            &RevealAllLayoutCx(fx.tcx),
+            fn_ty.fn_sig(fx.tcx),
+            &extra_args,
+        )
+    };
+
     let is_cold = instance
         .map(|inst| {
             fx.tcx
@@ -570,8 +447,8 @@ pub(crate) fn codegen_terminator_call<'tcx>(
 
     //   | indirect call target
     //   |         | the first argument to be passed
-    //   v         v          v virtual calls are special cased below
+    //   v         v
-    let (func_ref, first_arg, is_virtual_call) = match instance {
+    let (func_ref, first_arg) = match instance {
         // Trait object call
         Some(Instance {
             def: InstanceDef::Virtual(_, idx),
@@ -582,23 +459,19 @@ pub(crate) fn codegen_terminator_call<'tcx>(
                 let nop_inst = fx.bcx.ins().nop();
                 fx.add_comment(
                     nop_inst,
-                    format!(
+                    format!("virtual call; self arg pass mode: {:?}", &fn_abi.args[0],),
-                        "virtual call; self arg pass mode: {:?}",
-                        get_pass_mode(fx.tcx, args[0].layout())
-                    ),
                 );
             }
             let (ptr, method) = crate::vtable::get_ptr_and_method_ref(fx, args[0], idx);
-            (Some(method), Single(ptr), true)
+            (Some(method), smallvec![ptr])
         }
 
         // Normal call
         Some(_) => (
             None,
             args.get(0)
-                .map(|arg| adjust_arg_for_abi(fx, *arg))
+                .map(|arg| adjust_arg_for_abi(fx, *arg, &fn_abi.args[0]))
-                .unwrap_or(Empty),
+                .unwrap_or(smallvec![]),
-            false,
         ),
 
         // Indirect call
@@ -612,23 +485,27 @@ pub(crate) fn codegen_terminator_call<'tcx>(
             (
                 Some(func),
                 args.get(0)
-                    .map(|arg| adjust_arg_for_abi(fx, *arg))
+                    .map(|arg| adjust_arg_for_abi(fx, *arg, &fn_abi.args[0]))
-                    .unwrap_or(Empty),
+                    .unwrap_or(smallvec![]),
-                false,
             )
         }
     };
 
     let ret_place = destination.map(|(place, _)| place);
-    let (call_inst, call_args) =
+    let (call_inst, call_args) = self::returning::codegen_with_call_return_arg(
-        self::returning::codegen_with_call_return_arg(fx, fn_sig, ret_place, |fx, return_ptr| {
+        fx,
+        &fn_abi.ret,
+        ret_place,
+        |fx, return_ptr| {
+            let regular_args_count = args.len();
             let mut call_args: Vec<Value> = return_ptr
                 .into_iter()
                 .chain(first_arg.into_iter())
                 .chain(
                     args.into_iter()
+                        .enumerate()
                         .skip(1)
-                        .map(|arg| adjust_arg_for_abi(fx, arg).into_iter())
+                        .map(|(i, arg)| adjust_arg_for_abi(fx, arg, &fn_abi.args[i]).into_iter())
                         .flatten(),
                 )
                 .collect::<Vec<_>>();
@@ -639,18 +516,17 @@ pub(crate) fn codegen_terminator_call<'tcx>(
             {
                 // Pass the caller location for `#[track_caller]`.
                 let caller_location = fx.get_caller_location(span);
-                call_args.extend(adjust_arg_for_abi(fx, caller_location).into_iter());
+                call_args.extend(
+                    adjust_arg_for_abi(fx, caller_location, &fn_abi.args[regular_args_count])
+                        .into_iter(),
+                );
+                assert_eq!(fn_abi.args.len(), regular_args_count + 1);
+            } else {
+                assert_eq!(fn_abi.args.len(), regular_args_count);
             }
 
             let call_inst = if let Some(func_ref) = func_ref {
-                let sig = clif_sig_from_fn_sig(
+                let sig = clif_sig_from_fn_abi(fx.tcx, fx.triple(), &fn_abi);
-                    fx.tcx,
-                    fx.triple(),
-                    fn_sig,
-                    span,
-                    is_virtual_call,
-                    false, // calls through function pointers never pass the caller location
-                );
                 let sig = fx.bcx.import_signature(sig);
                 fx.bcx.ins().call_indirect(sig, func_ref, &call_args)
             } else {
@@ -660,7 +536,8 @@ pub(crate) fn codegen_terminator_call<'tcx>(
             };
 
             (call_inst, call_args)
-        });
+        },
+    );
 
     // FIXME find a cleaner way to support varargs
     if fn_sig.c_variadic {
@@ -701,37 +578,33 @@ pub(crate) fn codegen_drop<'tcx>(
     drop_place: CPlace<'tcx>,
 ) {
     let ty = drop_place.layout().ty;
-    let drop_fn = Instance::resolve_drop_in_place(fx.tcx, ty).polymorphize(fx.tcx);
+    let drop_instance = Instance::resolve_drop_in_place(fx.tcx, ty).polymorphize(fx.tcx);
 
-    if let ty::InstanceDef::DropGlue(_, None) = drop_fn.def {
+    if let ty::InstanceDef::DropGlue(_, None) = drop_instance.def {
         // we don't actually need to drop anything
     } else {
-        let drop_fn_ty = drop_fn.ty(fx.tcx, ParamEnv::reveal_all());
-        let fn_sig = fx.tcx.normalize_erasing_late_bound_regions(
-            ParamEnv::reveal_all(),
-            drop_fn_ty.fn_sig(fx.tcx),
-        );
-        assert_eq!(fn_sig.output(), fx.tcx.mk_unit());
-
         match ty.kind() {
             ty::Dynamic(..) => {
                 let (ptr, vtable) = drop_place.to_ptr_maybe_unsized();
                 let ptr = ptr.get_addr(fx);
                 let drop_fn = crate::vtable::drop_fn_of_obj(fx, vtable.unwrap());
 
-                let sig = clif_sig_from_fn_sig(
+                // FIXME(eddyb) perhaps move some of this logic into
-                    fx.tcx,
+                // `Instance::resolve_drop_in_place`?
-                    fx.triple(),
+                let virtual_drop = Instance {
-                    fn_sig,
+                    def: ty::InstanceDef::Virtual(drop_instance.def_id(), 0),
-                    span,
+                    substs: drop_instance.substs,
-                    true,
+                };
-                    false, // `drop_in_place` is never `#[track_caller]`
+                let fn_abi = FnAbi::of_instance(&RevealAllLayoutCx(fx.tcx), virtual_drop, &[]);
-                );
+
+                let sig = clif_sig_from_fn_abi(fx.tcx, fx.triple(), &fn_abi);
                 let sig = fx.bcx.import_signature(sig);
                 fx.bcx.ins().call_indirect(sig, drop_fn, &[ptr]);
             }
             _ => {
-                assert!(!matches!(drop_fn.def, InstanceDef::Virtual(_, _)));
+                assert!(!matches!(drop_instance.def, InstanceDef::Virtual(_, _)));
+
+                let fn_abi = FnAbi::of_instance(&RevealAllLayoutCx(fx.tcx), drop_instance, &[]);
 
                 let arg_value = drop_place.place_ref(
                     fx,
@@ -743,17 +616,19 @@ pub(crate) fn codegen_drop<'tcx>(
                         },
                     )),
                 );
-                let arg_value = adjust_arg_for_abi(fx, arg_value);
+                let arg_value = adjust_arg_for_abi(fx, arg_value, &fn_abi.args[0]);
 
                 let mut call_args: Vec<Value> = arg_value.into_iter().collect::<Vec<_>>();
 
-                if drop_fn.def.requires_caller_location(fx.tcx) {
+                if drop_instance.def.requires_caller_location(fx.tcx) {
                     // Pass the caller location for `#[track_caller]`.
                     let caller_location = fx.get_caller_location(span);
-                    call_args.extend(adjust_arg_for_abi(fx, caller_location).into_iter());
+                    call_args.extend(
+                        adjust_arg_for_abi(fx, caller_location, &fn_abi.args[1]).into_iter(),
+                    );
                 }
 
-                let func_ref = fx.get_function_ref(drop_fn);
+                let func_ref = fx.get_function_ref(drop_instance);
                 fx.bcx.ins().call(func_ref, &call_args);
             }
         }

compiler/rustc_codegen_cranelift/src/abi/pass_mode.rs

@@ -1,140 +1,281 @@
 //! Argument passing
 
 use crate::prelude::*;
+use crate::value_and_place::assert_assignable;
 
-pub(super) use EmptySinglePair::*;
+use cranelift_codegen::ir::{ArgumentExtension, ArgumentPurpose};
+use rustc_target::abi::call::{
+    ArgAbi, ArgAttributes, ArgExtension as RustcArgExtension, CastTarget, PassMode, Reg, RegKind,
+};
+use smallvec::{smallvec, SmallVec};
 
-#[derive(Copy, Clone, Debug)]
+pub(super) trait ArgAbiExt<'tcx> {
-pub(super) enum PassMode {
+    fn get_abi_param(&self, tcx: TyCtxt<'tcx>) -> SmallVec<[AbiParam; 2]>;
-    NoPass,
+    fn get_abi_return(&self, tcx: TyCtxt<'tcx>) -> (Option<AbiParam>, Vec<AbiParam>);
-    ByVal(Type),
-    ByValPair(Type, Type),
-    ByRef { size: Option<Size> },
 }
 
-#[derive(Copy, Clone, Debug)]
+fn reg_to_abi_param(reg: Reg) -> AbiParam {
-pub(super) enum EmptySinglePair<T> {
+    let clif_ty = match (reg.kind, reg.size.bytes()) {
-    Empty,
+        (RegKind::Integer, 1) => types::I8,
-    Single(T),
+        (RegKind::Integer, 2) => types::I16,
-    Pair(T, T),
+        (RegKind::Integer, 4) => types::I32,
+        (RegKind::Integer, 8) => types::I64,
+        (RegKind::Integer, 16) => types::I128,
+        (RegKind::Float, 4) => types::F32,
+        (RegKind::Float, 8) => types::F64,
+        (RegKind::Vector, size) => types::I8.by(u16::try_from(size).unwrap()).unwrap(),
+        _ => unreachable!("{:?}", reg),
+    };
+    AbiParam::new(clif_ty)
 }
 
-impl<T> EmptySinglePair<T> {
+fn apply_arg_attrs_to_abi_param(mut param: AbiParam, arg_attrs: ArgAttributes) -> AbiParam {
-    pub(super) fn into_iter(self) -> EmptySinglePairIter<T> {
+    match arg_attrs.arg_ext {
-        EmptySinglePairIter(self)
+        RustcArgExtension::None => {}
-    }
+        RustcArgExtension::Zext => param.extension = ArgumentExtension::Uext,
-
+        RustcArgExtension::Sext => param.extension = ArgumentExtension::Sext,
-    pub(super) fn map<U>(self, mut f: impl FnMut(T) -> U) -> EmptySinglePair<U> {
-        match self {
-            Empty => Empty,
-            Single(v) => Single(f(v)),
-            Pair(a, b) => Pair(f(a), f(b)),
-        }
     }
+    param
 }
 
-pub(super) struct EmptySinglePairIter<T>(EmptySinglePair<T>);
+fn cast_target_to_abi_params(cast: CastTarget) -> SmallVec<[AbiParam; 2]> {
-
+    let (rest_count, rem_bytes) = if cast.rest.unit.size.bytes() == 0 {
-impl<T> Iterator for EmptySinglePairIter<T> {
+        (0, 0)
-    type Item = T;
-
-    fn next(&mut self) -> Option<T> {
-        match std::mem::replace(&mut self.0, Empty) {
-            Empty => None,
-            Single(v) => Some(v),
-            Pair(a, b) => {
-                self.0 = Single(b);
-                Some(a)
-            }
-        }
-    }
-}
-
-impl<T: std::fmt::Debug> EmptySinglePair<T> {
-    pub(super) fn assert_single(self) -> T {
-        match self {
-            Single(v) => v,
-            _ => panic!("Called assert_single on {:?}", self),
-        }
-    }
-
-    pub(super) fn assert_pair(self) -> (T, T) {
-        match self {
-            Pair(a, b) => (a, b),
-            _ => panic!("Called assert_pair on {:?}", self),
-        }
-    }
-}
-
-impl PassMode {
-    pub(super) fn get_param_ty(self, tcx: TyCtxt<'_>) -> EmptySinglePair<Type> {
-        match self {
-            PassMode::NoPass => Empty,
-            PassMode::ByVal(clif_type) => Single(clif_type),
-            PassMode::ByValPair(a, b) => Pair(a, b),
-            PassMode::ByRef { size: Some(_) } => Single(pointer_ty(tcx)),
-            PassMode::ByRef { size: None } => Pair(pointer_ty(tcx), pointer_ty(tcx)),
-        }
-    }
-}
-
-pub(super) fn get_pass_mode<'tcx>(tcx: TyCtxt<'tcx>, layout: TyAndLayout<'tcx>) -> PassMode {
-    if layout.is_zst() {
-        // WARNING zst arguments must never be passed, as that will break CastKind::ClosureFnPointer
-        PassMode::NoPass
     } else {
-        match &layout.abi {
+        (
-            Abi::Uninhabited => PassMode::NoPass,
+            cast.rest.total.bytes() / cast.rest.unit.size.bytes(),
-            Abi::Scalar(scalar) => PassMode::ByVal(scalar_to_clif_type(tcx, scalar.clone())),
+            cast.rest.total.bytes() % cast.rest.unit.size.bytes(),
-            Abi::ScalarPair(a, b) => {
+        )
-                let a = scalar_to_clif_type(tcx, a.clone());
+    };
-                let b = scalar_to_clif_type(tcx, b.clone());
-                if a == types::I128 && b == types::I128 {
-                    // Returning (i128, i128) by-val-pair would take 4 regs, while only 3 are
-                    // available on x86_64. Cranelift gets confused when too many return params
-                    // are used.
-                    PassMode::ByRef {
-                        size: Some(layout.size),
-                    }
-                } else {
-                    PassMode::ByValPair(a, b)
-                }
-            }
 
-            // FIXME implement Vector Abi in a cg_llvm compatible way
+    if cast.prefix.iter().all(|x| x.is_none()) {
-            Abi::Vector { .. } => {
+        // Simplify to a single unit when there is no prefix and size <= unit size
-                if let Some(vector_ty) = crate::intrinsics::clif_vector_type(tcx, layout) {
+        if cast.rest.total <= cast.rest.unit.size {
-                    PassMode::ByVal(vector_ty)
+            let clif_ty = match (cast.rest.unit.kind, cast.rest.unit.size.bytes()) {
-                } else {
+                (RegKind::Integer, 1) => types::I8,
-                    PassMode::ByRef {
+                (RegKind::Integer, 2) => types::I16,
-                        size: Some(layout.size),
+                (RegKind::Integer, 3..=4) => types::I32,
-                    }
+                (RegKind::Integer, 5..=8) => types::I64,
-                }
+                (RegKind::Integer, 9..=16) => types::I128,
-            }
+                (RegKind::Float, 4) => types::F32,
-
+                (RegKind::Float, 8) => types::F64,
-            Abi::Aggregate { sized: true } => PassMode::ByRef {
+                (RegKind::Vector, size) => types::I8.by(u16::try_from(size).unwrap()).unwrap(),
-                size: Some(layout.size),
+                _ => unreachable!("{:?}", cast.rest.unit),
-            },
+            };
-            Abi::Aggregate { sized: false } => PassMode::ByRef { size: None },
+            return smallvec![AbiParam::new(clif_ty)];
         }
     }
+
+    // Create list of fields in the main structure
+    let mut args = cast
+        .prefix
+        .iter()
+        .flatten()
+        .map(|&kind| {
+            reg_to_abi_param(Reg {
+                kind,
+                size: cast.prefix_chunk_size,
+            })
+        })
+        .chain((0..rest_count).map(|_| reg_to_abi_param(cast.rest.unit)))
+        .collect::<SmallVec<_>>();
+
+    // Append final integer
+    if rem_bytes != 0 {
+        // Only integers can be really split further.
+        assert_eq!(cast.rest.unit.kind, RegKind::Integer);
+        args.push(reg_to_abi_param(Reg {
+            kind: RegKind::Integer,
+            size: Size::from_bytes(rem_bytes),
+        }));
+    }
+
+    args
+}
+
+impl<'tcx> ArgAbiExt<'tcx> for ArgAbi<'tcx, Ty<'tcx>> {
+    fn get_abi_param(&self, tcx: TyCtxt<'tcx>) -> SmallVec<[AbiParam; 2]> {
+        match self.mode {
+            PassMode::Ignore => smallvec![],
+            PassMode::Direct(attrs) => match &self.layout.abi {
+                Abi::Scalar(scalar) => {
+                    smallvec![apply_arg_attrs_to_abi_param(
+                        AbiParam::new(scalar_to_clif_type(tcx, scalar.clone())),
+                        attrs
+                    )]
+                }
+                Abi::Vector { .. } => {
+                    let vector_ty = crate::intrinsics::clif_vector_type(tcx, self.layout).unwrap();
+                    smallvec![AbiParam::new(vector_ty)]
+                }
+                _ => unreachable!("{:?}", self.layout.abi),
+            },
+            PassMode::Pair(attrs_a, attrs_b) => match &self.layout.abi {
+                Abi::ScalarPair(a, b) => {
+                    let a = scalar_to_clif_type(tcx, a.clone());
+                    let b = scalar_to_clif_type(tcx, b.clone());
+                    smallvec![
+                        apply_arg_attrs_to_abi_param(AbiParam::new(a), attrs_a),
+                        apply_arg_attrs_to_abi_param(AbiParam::new(b), attrs_b),
+                    ]
+                }
+                _ => unreachable!("{:?}", self.layout.abi),
+            },
+            PassMode::Cast(cast) => cast_target_to_abi_params(cast),
+            PassMode::Indirect {
+                attrs,
+                extra_attrs: None,
+                on_stack,
+            } => {
+                if on_stack {
+                    let size = u32::try_from(self.layout.size.bytes()).unwrap();
+                    smallvec![apply_arg_attrs_to_abi_param(
+                        AbiParam::special(pointer_ty(tcx), ArgumentPurpose::StructArgument(size),),
+                        attrs
+                    )]
+                } else {
+                    smallvec![apply_arg_attrs_to_abi_param(
+                        AbiParam::new(pointer_ty(tcx)),
+                        attrs
+                    )]
+                }
+            }
+            PassMode::Indirect {
+                attrs,
+                extra_attrs: Some(extra_attrs),
+                on_stack,
+            } => {
+                assert!(!on_stack);
+                smallvec![
+                    apply_arg_attrs_to_abi_param(AbiParam::new(pointer_ty(tcx)), attrs),
+                    apply_arg_attrs_to_abi_param(AbiParam::new(pointer_ty(tcx)), extra_attrs),
+                ]
+            }
+        }
+    }
+
+    fn get_abi_return(&self, tcx: TyCtxt<'tcx>) -> (Option<AbiParam>, Vec<AbiParam>) {
+        match self.mode {
+            PassMode::Ignore => (None, vec![]),
+            PassMode::Direct(_) => match &self.layout.abi {
+                Abi::Scalar(scalar) => (
+                    None,
+                    vec![AbiParam::new(scalar_to_clif_type(tcx, scalar.clone()))],
+                ),
+                Abi::Vector { .. } => {
+                    let vector_ty = crate::intrinsics::clif_vector_type(tcx, self.layout).unwrap();
+                    (None, vec![AbiParam::new(vector_ty)])
+                }
+                _ => unreachable!("{:?}", self.layout.abi),
+            },
+            PassMode::Pair(_, _) => match &self.layout.abi {
+                Abi::ScalarPair(a, b) => {
+                    let a = scalar_to_clif_type(tcx, a.clone());
+                    let b = scalar_to_clif_type(tcx, b.clone());
+                    (None, vec![AbiParam::new(a), AbiParam::new(b)])
+                }
+                _ => unreachable!("{:?}", self.layout.abi),
+            },
+            PassMode::Cast(cast) => (None, cast_target_to_abi_params(cast).into_iter().collect()),
+            PassMode::Indirect {
+                attrs: _,
+                extra_attrs: None,
+                on_stack,
+            } => {
+                assert!(!on_stack);
+                (
+                    Some(AbiParam::special(
+                        pointer_ty(tcx),
+                        ArgumentPurpose::StructReturn,
+                    )),
+                    vec![],
+                )
+            }
+            PassMode::Indirect {
+                attrs: _,
+                extra_attrs: Some(_),
+                on_stack: _,
+            } => unreachable!("unsized return value"),
+        }
+    }
+}
+
+pub(super) fn to_casted_value<'tcx>(
+    fx: &mut FunctionCx<'_, 'tcx, impl Module>,
+    arg: CValue<'tcx>,
+    cast: CastTarget,
+) -> SmallVec<[Value; 2]> {
+    let (ptr, meta) = arg.force_stack(fx);
+    assert!(meta.is_none());
+    let mut offset = 0;
+    cast_target_to_abi_params(cast)
+        .into_iter()
+        .map(|param| {
+            let val = ptr
+                .offset_i64(fx, offset)
+                .load(fx, param.value_type, MemFlags::new());
+            offset += i64::from(param.value_type.bytes());
+            val
+        })
+        .collect()
+}
+
+pub(super) fn from_casted_value<'tcx>(
+    fx: &mut FunctionCx<'_, 'tcx, impl Module>,
+    block_params: &[Value],
+    layout: TyAndLayout<'tcx>,
+    cast: CastTarget,
+) -> CValue<'tcx> {
+    let abi_params = cast_target_to_abi_params(cast);
+    let abi_param_size: u32 = abi_params
+        .iter()
+        .map(|param| param.value_type.bytes())
+        .sum();
+    let layout_size = u32::try_from(layout.size.bytes()).unwrap();
+    let stack_slot = fx.bcx.create_stack_slot(StackSlotData {
+        kind: StackSlotKind::ExplicitSlot,
+        // FIXME Don't force the size to a multiple of 16 bytes once Cranelift gets a way to
+        // specify stack slot alignment.
+        // Stack slot size may be bigger for for example `[u8; 3]` which is packed into an `i32`.
+        // It may also be smaller for example when the type is a wrapper around an integer with a
+        // larger alignment than the integer.
+        size: (std::cmp::max(abi_param_size, layout_size) + 15) / 16 * 16,
+        offset: None,
+    });
+    let ptr = Pointer::new(fx.bcx.ins().stack_addr(pointer_ty(fx.tcx), stack_slot, 0));
+    let mut offset = 0;
+    let mut block_params_iter = block_params.into_iter().copied();
+    for param in abi_params {
+        let val = ptr.offset_i64(fx, offset).store(
+            fx,
+            block_params_iter.next().unwrap(),
+            MemFlags::new(),
+        );
+        offset += i64::from(param.value_type.bytes());
+        val
+    }
+    assert_eq!(block_params_iter.next(), None, "Leftover block param");
+    CValue::by_ref(ptr, layout)
 }
 
 /// Get a set of values to be passed as function arguments.
 pub(super) fn adjust_arg_for_abi<'tcx>(
     fx: &mut FunctionCx<'_, 'tcx, impl Module>,
     arg: CValue<'tcx>,
-) -> EmptySinglePair<Value> {
+    arg_abi: &ArgAbi<'tcx, Ty<'tcx>>,
-    match get_pass_mode(fx.tcx, arg.layout()) {
+) -> SmallVec<[Value; 2]> {
-        PassMode::NoPass => Empty,
+    assert_assignable(fx, arg.layout().ty, arg_abi.layout.ty);
-        PassMode::ByVal(_) => Single(arg.load_scalar(fx)),
+    match arg_abi.mode {
-        PassMode::ByValPair(_, _) => {
+        PassMode::Ignore => smallvec![],
+        PassMode::Direct(_) => smallvec![arg.load_scalar(fx)],
+        PassMode::Pair(_, _) => {
             let (a, b) = arg.load_scalar_pair(fx);
-            Pair(a, b)
+            smallvec![a, b]
         }
-        PassMode::ByRef { size: _ } => match arg.force_stack(fx) {
+        PassMode::Cast(cast) => to_casted_value(fx, arg, cast),
-            (ptr, None) => Single(ptr.get_addr(fx)),
+        PassMode::Indirect { .. } => match arg.force_stack(fx) {
-            (ptr, Some(meta)) => Pair(ptr.get_addr(fx), meta),
+            (ptr, None) => smallvec![ptr.get_addr(fx)],
+            (ptr, Some(meta)) => smallvec![ptr.get_addr(fx), meta],
         },
     }
 }
@@ -143,20 +284,23 @@ pub(super) fn adjust_arg_for_abi<'tcx>(
 /// as necessary.
 pub(super) fn cvalue_for_param<'tcx>(
     fx: &mut FunctionCx<'_, 'tcx, impl Module>,
-    start_block: Block,
     #[cfg_attr(not(debug_assertions), allow(unused_variables))] local: Option<mir::Local>,
     #[cfg_attr(not(debug_assertions), allow(unused_variables))] local_field: Option<usize>,
-    arg_ty: Ty<'tcx>,
+    arg_abi: &ArgAbi<'tcx, Ty<'tcx>>,
+    block_params_iter: &mut impl Iterator<Item = Value>,
 ) -> Option<CValue<'tcx>> {
-    let layout = fx.layout_of(arg_ty);
+    let block_params = arg_abi
-    let pass_mode = get_pass_mode(fx.tcx, layout);
+        .get_abi_param(fx.tcx)
-
+        .into_iter()
-    if let PassMode::NoPass = pass_mode {
+        .map(|abi_param| {
-        return None;
+            let block_param = block_params_iter.next().unwrap();
-    }
+            assert_eq!(
-
+                fx.bcx.func.dfg.value_type(block_param),
-    let clif_types = pass_mode.get_param_ty(fx.tcx);
+                abi_param.value_type
-    let block_params = clif_types.map(|t| fx.bcx.append_block_param(start_block, t));
+            );
+            block_param
+        })
+        .collect::<SmallVec<[_; 2]>>();
 
     #[cfg(debug_assertions)]
     crate::abi::comments::add_arg_comment(
@@ -164,25 +308,48 @@ pub(super) fn cvalue_for_param<'tcx>(
         "arg",
         local,
         local_field,
-        block_params,
+        &block_params,
-        pass_mode,
+        arg_abi.mode,
-        arg_ty,
+        arg_abi.layout,
     );
 
-    match pass_mode {
+    match arg_abi.mode {
-        PassMode::NoPass => unreachable!(),
+        PassMode::Ignore => None,
-        PassMode::ByVal(_) => Some(CValue::by_val(block_params.assert_single(), layout)),
+        PassMode::Direct(_) => {
-        PassMode::ByValPair(_, _) => {
+            assert_eq!(block_params.len(), 1, "{:?}", block_params);
-            let (a, b) = block_params.assert_pair();
+            Some(CValue::by_val(block_params[0], arg_abi.layout))
-            Some(CValue::by_val_pair(a, b, layout))
         }
-        PassMode::ByRef { size: Some(_) } => Some(CValue::by_ref(
+        PassMode::Pair(_, _) => {
-            Pointer::new(block_params.assert_single()),
+            assert_eq!(block_params.len(), 2, "{:?}", block_params);
-            layout,
+            Some(CValue::by_val_pair(
-        )),
+                block_params[0],
-        PassMode::ByRef { size: None } => {
+                block_params[1],
-            let (ptr, meta) = block_params.assert_pair();
+                arg_abi.layout,
-            Some(CValue::by_ref_unsized(Pointer::new(ptr), meta, layout))
+            ))
+        }
+        PassMode::Cast(cast) => Some(from_casted_value(fx, &block_params, arg_abi.layout, cast)),
+        PassMode::Indirect {
+            attrs: _,
+            extra_attrs: None,
+            on_stack: _,
+        } => {
+            assert_eq!(block_params.len(), 1, "{:?}", block_params);
+            Some(CValue::by_ref(
+                Pointer::new(block_params[0]),
+                arg_abi.layout,
+            ))
+        }
+        PassMode::Indirect {
+            attrs: _,
+            extra_attrs: Some(_),
+            on_stack: _,
+        } => {
+            assert_eq!(block_params.len(), 2, "{:?}", block_params);
+            Some(CValue::by_ref_unsized(
+                Pointer::new(block_params[0]),
+                block_params[1],
+                arg_abi.layout,
+            ))
         }
     }
 }

compiler/rustc_codegen_cranelift/src/abi/returning.rs

@@ -1,21 +1,57 @@
 //! Return value handling
 
-use crate::abi::pass_mode::*;
 use crate::prelude::*;
 
-fn return_layout<'a, 'tcx>(fx: &mut FunctionCx<'a, 'tcx, impl Module>) -> TyAndLayout<'tcx> {
+use rustc_middle::ty::layout::FnAbiExt;
-    fx.layout_of(fx.monomorphize(&fx.mir.local_decls[RETURN_PLACE].ty))
+use rustc_target::abi::call::{ArgAbi, FnAbi, PassMode};
-}
+use smallvec::{smallvec, SmallVec};
 
 /// Can the given type be returned into an ssa var or does it need to be returned on the stack.
 pub(crate) fn can_return_to_ssa_var<'tcx>(
-    tcx: TyCtxt<'tcx>,
+    fx: &FunctionCx<'_, 'tcx, impl Module>,
-    dest_layout: TyAndLayout<'tcx>,
+    func: &mir::Operand<'tcx>,
+    args: &[mir::Operand<'tcx>],
 ) -> bool {
-    match get_pass_mode(tcx, dest_layout) {
+    let fn_ty = fx.monomorphize(func.ty(fx.mir, fx.tcx));
-        PassMode::NoPass | PassMode::ByVal(_) | PassMode::ByValPair(_, _) => true,
+    let fn_sig = fx
-        // FIXME Make it possible to return ByRef to an ssa var.
+        .tcx
-        PassMode::ByRef { size: _ } => false,
+        .normalize_erasing_late_bound_regions(ParamEnv::reveal_all(), fn_ty.fn_sig(fx.tcx));
+
+    // Handle special calls like instrinsics and empty drop glue.
+    let instance = if let ty::FnDef(def_id, substs) = *fn_ty.kind() {
+        let instance = ty::Instance::resolve(fx.tcx, ty::ParamEnv::reveal_all(), def_id, substs)
+            .unwrap()
+            .unwrap()
+            .polymorphize(fx.tcx);
+
+        match instance.def {
+            InstanceDef::Intrinsic(_) | InstanceDef::DropGlue(_, _) => {
+                return true;
+            }
+            _ => Some(instance),
+        }
+    } else {
+        None
+    };
+
+    let extra_args = &args[fn_sig.inputs().len()..];
+    let extra_args = extra_args
+        .iter()
+        .map(|op_arg| fx.monomorphize(op_arg.ty(fx.mir, fx.tcx)))
+        .collect::<Vec<_>>();
+    let fn_abi = if let Some(instance) = instance {
+        FnAbi::of_instance(&RevealAllLayoutCx(fx.tcx), instance, &extra_args)
+    } else {
+        FnAbi::of_fn_ptr(
+            &RevealAllLayoutCx(fx.tcx),
+            fn_ty.fn_sig(fx.tcx),
+            &extra_args,
+        )
+    };
+    match fn_abi.ret.mode {
+        PassMode::Ignore | PassMode::Direct(_) | PassMode::Pair(_, _) => true,
+        // FIXME Make it possible to return Cast and Indirect to an ssa var.
+        PassMode::Cast(_) | PassMode::Indirect { .. } => false,
     }
 }
 
@@ -24,27 +60,45 @@ pub(crate) fn can_return_to_ssa_var<'tcx>(
 pub(super) fn codegen_return_param<'tcx>(
     fx: &mut FunctionCx<'_, 'tcx, impl Module>,
     ssa_analyzed: &rustc_index::vec::IndexVec<Local, crate::analyze::SsaKind>,
-    start_block: Block,
+    block_params_iter: &mut impl Iterator<Item = Value>,
 ) -> CPlace<'tcx> {
-    let ret_layout = return_layout(fx);
+    let (ret_place, ret_param): (_, SmallVec<[_; 2]>) = match fx.fn_abi.as_ref().unwrap().ret.mode {
-    let ret_pass_mode = get_pass_mode(fx.tcx, ret_layout);
+        PassMode::Ignore => (
-    let (ret_place, ret_param) = match ret_pass_mode {
+            CPlace::no_place(fx.fn_abi.as_ref().unwrap().ret.layout),
-        PassMode::NoPass => (CPlace::no_place(ret_layout), Empty),
+            smallvec![],
-        PassMode::ByVal(_) | PassMode::ByValPair(_, _) => {
+        ),
+        PassMode::Direct(_) | PassMode::Pair(_, _) | PassMode::Cast(_) => {
             let is_ssa = ssa_analyzed[RETURN_PLACE] == crate::analyze::SsaKind::Ssa;
             (
-                super::make_local_place(fx, RETURN_PLACE, ret_layout, is_ssa),
+                super::make_local_place(
-                Empty,
+                    fx,
+                    RETURN_PLACE,
+                    fx.fn_abi.as_ref().unwrap().ret.layout,
+                    is_ssa,
+                ),
+                smallvec![],
             )
         }
-        PassMode::ByRef { size: Some(_) } => {
+        PassMode::Indirect {
-            let ret_param = fx.bcx.append_block_param(start_block, fx.pointer_type);
+            attrs: _,
+            extra_attrs: None,
+            on_stack: _,
+        } => {
+            let ret_param = block_params_iter.next().unwrap();
+            assert_eq!(fx.bcx.func.dfg.value_type(ret_param), pointer_ty(fx.tcx));
             (
-                CPlace::for_ptr(Pointer::new(ret_param), ret_layout),
+                CPlace::for_ptr(
-                Single(ret_param),
+                    Pointer::new(ret_param),
+                    fx.fn_abi.as_ref().unwrap().ret.layout,
+                ),
+                smallvec![ret_param],
             )
         }
-        PassMode::ByRef { size: None } => todo!(),
+        PassMode::Indirect {
+            attrs: _,
+            extra_attrs: Some(_),
+            on_stack: _,
+        } => unreachable!("unsized return value"),
     };
 
     #[cfg(not(debug_assertions))]
@@ -56,9 +110,9 @@ pub(super) fn codegen_return_param<'tcx>(
         "ret",
         Some(RETURN_PLACE),
         None,
-        ret_param,
+        &ret_param,
-        ret_pass_mode,
+        fx.fn_abi.as_ref().unwrap().ret.mode,
-        ret_layout.ty,
+        fx.fn_abi.as_ref().unwrap().ret.layout,
     );
 
     ret_place
@@ -68,42 +122,71 @@ pub(super) fn codegen_return_param<'tcx>(
 /// returns the call return value(s) if any are written to the correct place.
 pub(super) fn codegen_with_call_return_arg<'tcx, M: Module, T>(
     fx: &mut FunctionCx<'_, 'tcx, M>,
-    fn_sig: FnSig<'tcx>,
+    ret_arg_abi: &ArgAbi<'tcx, Ty<'tcx>>,
     ret_place: Option<CPlace<'tcx>>,
     f: impl FnOnce(&mut FunctionCx<'_, 'tcx, M>, Option<Value>) -> (Inst, T),
 ) -> (Inst, T) {
-    let ret_layout = fx.layout_of(fn_sig.output());
+    let return_ptr = match ret_arg_abi.mode {
-
+        PassMode::Ignore => None,
-    let output_pass_mode = get_pass_mode(fx.tcx, ret_layout);
+        PassMode::Indirect {
-    let return_ptr = match output_pass_mode {
+            attrs: _,
-        PassMode::NoPass => None,
+            extra_attrs: None,
-        PassMode::ByRef { size: Some(_) } => match ret_place {
+            on_stack: _,
+        } => match ret_place {
             Some(ret_place) => Some(ret_place.to_ptr().get_addr(fx)),
             None => Some(fx.bcx.ins().iconst(fx.pointer_type, 43)), // FIXME allocate temp stack slot
         },
-        PassMode::ByRef { size: None } => todo!(),
+        PassMode::Indirect {
-        PassMode::ByVal(_) | PassMode::ByValPair(_, _) => None,
+            attrs: _,
+            extra_attrs: Some(_),
+            on_stack: _,
+        } => unreachable!("unsized return value"),
+        PassMode::Direct(_) | PassMode::Pair(_, _) | PassMode::Cast(_) => None,
     };
 
     let (call_inst, meta) = f(fx, return_ptr);
 
-    match output_pass_mode {
+    match ret_arg_abi.mode {
-        PassMode::NoPass => {}
+        PassMode::Ignore => {}
-        PassMode::ByVal(_) => {
+        PassMode::Direct(_) => {
             if let Some(ret_place) = ret_place {
                 let ret_val = fx.bcx.inst_results(call_inst)[0];
-                ret_place.write_cvalue(fx, CValue::by_val(ret_val, ret_layout));
+                ret_place.write_cvalue(fx, CValue::by_val(ret_val, ret_arg_abi.layout));
             }
         }
-        PassMode::ByValPair(_, _) => {
+        PassMode::Pair(_, _) => {
             if let Some(ret_place) = ret_place {
                 let ret_val_a = fx.bcx.inst_results(call_inst)[0];
                 let ret_val_b = fx.bcx.inst_results(call_inst)[1];
-                ret_place.write_cvalue(fx, CValue::by_val_pair(ret_val_a, ret_val_b, ret_layout));
+                ret_place.write_cvalue(
+                    fx,
+                    CValue::by_val_pair(ret_val_a, ret_val_b, ret_arg_abi.layout),
+                );
             }
         }
-        PassMode::ByRef { size: Some(_) } => {}
+        PassMode::Cast(cast) => {
-        PassMode::ByRef { size: None } => todo!(),
+            if let Some(ret_place) = ret_place {
+                let results = fx
+                    .bcx
+                    .inst_results(call_inst)
+                    .into_iter()
+                    .copied()
+                    .collect::<SmallVec<[Value; 2]>>();
+                let result =
+                    super::pass_mode::from_casted_value(fx, &results, ret_place.layout(), cast);
+                ret_place.write_cvalue(fx, result);
+            }
+        }
+        PassMode::Indirect {
+            attrs: _,
+            extra_attrs: None,
+            on_stack: _,
+        } => {}
+        PassMode::Indirect {
+            attrs: _,
+            extra_attrs: Some(_),
+            on_stack: _,
+        } => unreachable!("unsized return value"),
     }
 
     (call_inst, meta)
@@ -111,20 +194,35 @@ pub(super) fn codegen_with_call_return_arg<'tcx, M: Module, T>(
 
 /// Codegen a return instruction with the right return value(s) if any.
 pub(crate) fn codegen_return(fx: &mut FunctionCx<'_, '_, impl Module>) {
-    match get_pass_mode(fx.tcx, return_layout(fx)) {
+    match fx.fn_abi.as_ref().unwrap().ret.mode {
-        PassMode::NoPass | PassMode::ByRef { size: Some(_) } => {
+        PassMode::Ignore
+        | PassMode::Indirect {
+            attrs: _,
+            extra_attrs: None,
+            on_stack: _,
+        } => {
             fx.bcx.ins().return_(&[]);
         }
-        PassMode::ByRef { size: None } => todo!(),
+        PassMode::Indirect {
-        PassMode::ByVal(_) => {
+            attrs: _,
+            extra_attrs: Some(_),
+            on_stack: _,
+        } => unreachable!("unsized return value"),
+        PassMode::Direct(_) => {
             let place = fx.get_local_place(RETURN_PLACE);
             let ret_val = place.to_cvalue(fx).load_scalar(fx);
             fx.bcx.ins().return_(&[ret_val]);
         }
-        PassMode::ByValPair(_, _) => {
+        PassMode::Pair(_, _) => {
             let place = fx.get_local_place(RETURN_PLACE);
             let (ret_val_a, ret_val_b) = place.to_cvalue(fx).load_scalar_pair(fx);
             fx.bcx.ins().return_(&[ret_val_a, ret_val_b]);
         }
+        PassMode::Cast(cast) => {
+            let place = fx.get_local_place(RETURN_PLACE);
+            let ret_val = place.to_cvalue(fx);
+            let ret_vals = super::pass_mode::to_casted_value(fx, ret_val, cast);
+            fx.bcx.ins().return_(&ret_vals);
+        }
     }
 }

compiler/rustc_codegen_cranelift/src/analyze.rs

@@ -40,11 +40,14 @@ pub(crate) fn analyze(fx: &FunctionCx<'_, '_, impl Module>) -> IndexVec<Local, S
         }
 
         match &bb.terminator().kind {
-            TerminatorKind::Call { destination, .. } => {
+            TerminatorKind::Call {
+                destination,
+                func,
+                args,
+                ..
+            } => {
                 if let Some((dest_place, _dest_bb)) = destination {
-                    let dest_layout = fx
+                    if !crate::abi::can_return_to_ssa_var(fx, func, args) {
-                        .layout_of(fx.monomorphize(&dest_place.ty(&fx.mir.local_decls, fx.tcx).ty));
-                    if !crate::abi::can_return_to_ssa_var(fx.tcx, dest_layout) {
                         not_ssa(&mut flag_map, dest_place.local)
                     }
                 }

compiler/rustc_codegen_cranelift/src/base.rs

@@ -2,6 +2,8 @@
 
 use rustc_index::vec::IndexVec;
 use rustc_middle::ty::adjustment::PointerCast;
+use rustc_middle::ty::layout::FnAbiExt;
+use rustc_target::abi::call::FnAbi;
 
 use crate::prelude::*;
 
@@ -19,7 +21,8 @@ pub(crate) fn codegen_fn<'tcx>(
     let mir = tcx.instance_mir(instance.def);
 
     // Declare function
-    let (name, sig) = get_function_name_and_sig(tcx, cx.module.isa().triple(), instance, false);
+    let name = tcx.symbol_name(instance).name.to_string();
+    let sig = get_function_sig(tcx, cx.module.isa().triple(), instance);
     let func_id = cx.module.declare_function(&name, linkage, &sig).unwrap();
 
     cx.cached_context.clear();
@@ -50,6 +53,7 @@ pub(crate) fn codegen_fn<'tcx>(
 
         instance,
         mir,
+        fn_abi: Some(FnAbi::of_instance(&RevealAllLayoutCx(tcx), instance, &[])),
 
         bcx,
         block_map,
@@ -117,6 +121,9 @@ pub(crate) fn codegen_fn<'tcx>(
     context.compute_domtree();
     context.eliminate_unreachable_code(cx.module.isa()).unwrap();
     context.dce(cx.module.isa()).unwrap();
+    // Some Cranelift optimizations expect the domtree to not yet be computed and as such don't
+    // invalidate it when it would change.
+    context.domtree.clear();
 
     context.want_disasm = crate::pretty_clif::should_write_ir(tcx);
 
@@ -1053,7 +1060,11 @@ pub(crate) fn codegen_panic_inner<'tcx>(
 
     fx.lib_call(
         &*symbol_name,
-        vec![fx.pointer_type, fx.pointer_type, fx.pointer_type],
+        vec![
+            AbiParam::new(fx.pointer_type),
+            AbiParam::new(fx.pointer_type),
+            AbiParam::new(fx.pointer_type),
+        ],
         vec![],
         args,
     );

compiler/rustc_codegen_cranelift/src/bin/cg_clif.rs

@@ -6,7 +6,7 @@ extern crate rustc_interface;
 extern crate rustc_session;
 extern crate rustc_target;
 
-use rustc_data_structures::profiling::print_time_passes_entry;
+use rustc_data_structures::profiling::{get_resident_set_size, print_time_passes_entry};
 use rustc_interface::interface;
 use rustc_session::config::ErrorOutputType;
 use rustc_session::early_error;
@@ -39,7 +39,8 @@ impl rustc_driver::Callbacks for CraneliftPassesCallbacks {
 }
 
 fn main() {
-    let start = std::time::Instant::now();
+    let start_time = std::time::Instant::now();
+    let start_rss = get_resident_set_size();
     rustc_driver::init_rustc_env_logger();
     let mut callbacks = CraneliftPassesCallbacks::default();
     rustc_driver::install_ice_hook();
@@ -61,7 +62,11 @@ fn main() {
         })));
         run_compiler.run()
     });
-    // The extra `\t` is necessary to align this label with the others.
+
-    print_time_passes_entry(callbacks.time_passes, "\ttotal", start.elapsed());
+    if callbacks.time_passes {
+        let end_rss = get_resident_set_size();
+        print_time_passes_entry("total", start_time.elapsed(), start_rss, end_rss);
+    }
+
     std::process::exit(exit_code)
 }

compiler/rustc_codegen_cranelift/src/bin/cg_clif_build_sysroot.rs

@@ -53,10 +53,7 @@ impl rustc_driver::Callbacks for CraneliftPassesCallbacks {
                 .unwrap()
                 .parent()
                 .unwrap()
-                .parent()
+                .to_owned(),
-                .unwrap()
-                .join("build_sysroot")
-                .join("sysroot"),
         );
     }
 }

compiler/rustc_codegen_cranelift/src/codegen_i128.rs

@@ -1,5 +1,7 @@
 //! Replaces 128-bit operators with lang item calls where necessary
 
+use cranelift_codegen::ir::ArgumentPurpose;
+
 use crate::prelude::*;
 
 pub(crate) fn maybe_codegen<'tcx>(
@@ -24,41 +26,41 @@ pub(crate) fn maybe_codegen<'tcx>(
             None
         }
         BinOp::Add | BinOp::Sub if !checked => None,
-        BinOp::Add => {
+        BinOp::Mul if !checked => {
-            let out_ty = fx.tcx.mk_tup([lhs.layout().ty, fx.tcx.types.bool].iter());
+            let val_ty = if is_signed {
-            return Some(if is_signed {
+                fx.tcx.types.i128
-                fx.easy_call("__rust_i128_addo", &[lhs, rhs], out_ty)
             } else {
-                fx.easy_call("__rust_u128_addo", &[lhs, rhs], out_ty)
+                fx.tcx.types.u128
-            });
+            };
+            Some(fx.easy_call("__multi3", &[lhs, rhs], val_ty))
         }
-        BinOp::Sub => {
+        BinOp::Add | BinOp::Sub | BinOp::Mul => {
+            assert!(checked);
             let out_ty = fx.tcx.mk_tup([lhs.layout().ty, fx.tcx.types.bool].iter());
-            return Some(if is_signed {
+            let out_place = CPlace::new_stack_slot(fx, fx.layout_of(out_ty));
-                fx.easy_call("__rust_i128_subo", &[lhs, rhs], out_ty)
+            let param_types = vec![
-            } else {
+                AbiParam::special(pointer_ty(fx.tcx), ArgumentPurpose::StructReturn),
-                fx.easy_call("__rust_u128_subo", &[lhs, rhs], out_ty)
+                AbiParam::new(types::I128),
-            });
+                AbiParam::new(types::I128),
+            ];
+            let args = [
+                out_place.to_ptr().get_addr(fx),
+                lhs.load_scalar(fx),
+                rhs.load_scalar(fx),
+            ];
+            let name = match (bin_op, is_signed) {
+                (BinOp::Add, false) => "__rust_u128_addo",
+                (BinOp::Add, true) => "__rust_i128_addo",
+                (BinOp::Sub, false) => "__rust_u128_subo",
+                (BinOp::Sub, true) => "__rust_i128_subo",
+                (BinOp::Mul, false) => "__rust_u128_mulo",
+                (BinOp::Mul, true) => "__rust_i128_mulo",
+                _ => unreachable!(),
+            };
+            fx.lib_call(name, param_types, vec![], &args);
+            Some(out_place.to_cvalue(fx))
         }
         BinOp::Offset => unreachable!("offset should only be used on pointers, not 128bit ints"),
-        BinOp::Mul => {
-            let res = if checked {
-                let out_ty = fx.tcx.mk_tup([lhs.layout().ty, fx.tcx.types.bool].iter());
-                if is_signed {
-                    fx.easy_call("__rust_i128_mulo", &[lhs, rhs], out_ty)
-                } else {
-                    fx.easy_call("__rust_u128_mulo", &[lhs, rhs], out_ty)
-                }
-            } else {
-                let val_ty = if is_signed {
-                    fx.tcx.types.i128
-                } else {
-                    fx.tcx.types.u128
-                };
-                fx.easy_call("__multi3", &[lhs, rhs], val_ty)
-            };
-            Some(res)
-        }
         BinOp::Div => {
             assert!(!checked);
             if is_signed {

compiler/rustc_codegen_cranelift/src/common.rs

@@ -1,4 +1,5 @@
 use rustc_index::vec::IndexVec;
+use rustc_target::abi::call::FnAbi;
 use rustc_target::abi::{Integer, Primitive};
 use rustc_target::spec::{HasTargetSpec, Target};
 
@@ -294,6 +295,7 @@ pub(crate) struct FunctionCx<'clif, 'tcx, M: Module> {
 
     pub(crate) instance: Instance<'tcx>,
     pub(crate) mir: &'tcx Body<'tcx>,
+    pub(crate) fn_abi: Option<FnAbi<'tcx, Ty<'tcx>>>,
 
     pub(crate) bcx: FunctionBuilder<'clif>,
     pub(crate) block_map: IndexVec<BasicBlock, Block>,
@@ -319,16 +321,7 @@ impl<'tcx, M: Module> LayoutOf for FunctionCx<'_, 'tcx, M> {
     type TyAndLayout = TyAndLayout<'tcx>;
 
     fn layout_of(&self, ty: Ty<'tcx>) -> TyAndLayout<'tcx> {
-        assert!(!ty.still_further_specializable());
+        RevealAllLayoutCx(self.tcx).layout_of(ty)
-        self.tcx
-            .layout_of(ParamEnv::reveal_all().and(&ty))
-            .unwrap_or_else(|e| {
-                if let layout::LayoutError::SizeOverflow(_) = e {
-                    self.tcx.sess.fatal(&e.to_string())
-                } else {
-                    bug!("failed to get layout for `{}`: {}", ty, e)
-                }
-            })
     }
 }
 
@@ -442,3 +435,47 @@ impl<'tcx, M: Module> FunctionCx<'_, 'tcx, M> {
         self.bcx.ins().global_value(self.pointer_type, local_msg_id)
     }
 }
+
+pub(crate) struct RevealAllLayoutCx<'tcx>(pub(crate) TyCtxt<'tcx>);
+
+impl<'tcx> LayoutOf for RevealAllLayoutCx<'tcx> {
+    type Ty = Ty<'tcx>;
+    type TyAndLayout = TyAndLayout<'tcx>;
+
+    fn layout_of(&self, ty: Ty<'tcx>) -> TyAndLayout<'tcx> {
+        assert!(!ty.still_further_specializable());
+        self.0
+            .layout_of(ParamEnv::reveal_all().and(&ty))
+            .unwrap_or_else(|e| {
+                if let layout::LayoutError::SizeOverflow(_) = e {
+                    self.0.sess.fatal(&e.to_string())
+                } else {
+                    bug!("failed to get layout for `{}`: {}", ty, e)
+                }
+            })
+    }
+}
+
+impl<'tcx> layout::HasTyCtxt<'tcx> for RevealAllLayoutCx<'tcx> {
+    fn tcx<'b>(&'b self) -> TyCtxt<'tcx> {
+        self.0
+    }
+}
+
+impl<'tcx> rustc_target::abi::HasDataLayout for RevealAllLayoutCx<'tcx> {
+    fn data_layout(&self) -> &rustc_target::abi::TargetDataLayout {
+        &self.0.data_layout
+    }
+}
+
+impl<'tcx> layout::HasParamEnv<'tcx> for RevealAllLayoutCx<'tcx> {
+    fn param_env(&self) -> ParamEnv<'tcx> {
+        ParamEnv::reveal_all()
+    }
+}
+
+impl<'tcx> HasTargetSpec for RevealAllLayoutCx<'tcx> {
+    fn target_spec(&self) -> &Target {
+        &self.0.sess.target
+    }
+}

compiler/rustc_codegen_cranelift/src/driver/aot.rs

@@ -281,9 +281,6 @@ pub(super) fn run_aot(
         None
     };
 
-    rustc_incremental::assert_dep_graph(tcx);
-    rustc_incremental::save_dep_graph(tcx);
-
     let metadata_module = if need_metadata_module {
         let _timer = tcx.prof.generic_activity("codegen crate metadata");
         let (metadata_cgu_name, tmp_file) = tcx.sess.time("write compressed metadata", || {
@@ -322,10 +319,6 @@ pub(super) fn run_aot(
         None
     };
 
-    if tcx.sess.opts.output_types.should_codegen() {
-        rustc_incremental::assert_module_sources::assert_module_sources(tcx);
-    }
-
     Box::new((
         CodegenResults {
             crate_name: tcx.crate_name(LOCAL_CRATE),

compiler/rustc_codegen_cranelift/src/driver/jit.rs

@@ -156,12 +156,8 @@ extern "C" fn __clif_jit_fn(instance_ptr: *const Instance<'static>) -> *const u8
             let jit_module = jit_module.as_mut().unwrap();
             let mut cx = crate::CodegenCx::new(tcx, jit_module, false, false);
 
-            let (name, sig) = crate::abi::get_function_name_and_sig(
+            let name = tcx.symbol_name(instance).name.to_string();
-                tcx,
+            let sig = crate::abi::get_function_sig(tcx, cx.module.isa().triple(), instance);
-                cx.module.isa().triple(),
-                instance,
-                true,
-            );
             let func_id = cx
                 .module
                 .declare_function(&name, Linkage::Export, &sig)
@@ -246,8 +242,8 @@ pub(super) fn codegen_shim<'tcx>(cx: &mut CodegenCx<'tcx, impl Module>, inst: In
 
     let pointer_type = cx.module.target_config().pointer_type();
 
-    let (name, sig) =
+    let name = tcx.symbol_name(inst).name.to_string();
-        crate::abi::get_function_name_and_sig(tcx, cx.module.isa().triple(), inst, true);
+    let sig = crate::abi::get_function_sig(tcx, cx.module.isa().triple(), inst);
     let func_id = cx
         .module
         .declare_function(&name, Linkage::Export, &sig)

compiler/rustc_codegen_cranelift/src/driver/mod.rs

@@ -50,12 +50,9 @@ fn predefine_mono_items<'tcx>(
         for &(mono_item, (linkage, visibility)) in mono_items {
             match mono_item {
                 MonoItem::Fn(instance) => {
-                    let (name, sig) = get_function_name_and_sig(
+                    let name = cx.tcx.symbol_name(instance).name.to_string();
-                        cx.tcx,
+                    let _inst_guard = crate::PrintOnPanic(|| format!("{:?} {}", instance, name));
-                        cx.module.isa().triple(),
+                    let sig = get_function_sig(cx.tcx, cx.module.isa().triple(), instance);
-                        instance,
-                        false,
-                    );
                     let linkage = crate::linkage::get_clif_linkage(mono_item, linkage, visibility);
                     cx.module.declare_function(&name, linkage, &sig).unwrap();
                 }

compiler/rustc_codegen_cranelift/src/lib.rs

@@ -27,7 +27,6 @@ extern crate rustc_incremental;
 extern crate rustc_index;
 extern crate rustc_session;
 extern crate rustc_span;
-extern crate rustc_symbol_mangling;
 extern crate rustc_target;
 
 // This prevents duplicating functions and statics that are already part of the host rustc process.
@@ -90,7 +89,8 @@ mod prelude {
     pub(crate) use rustc_middle::mir::{self, *};
     pub(crate) use rustc_middle::ty::layout::{self, TyAndLayout};
     pub(crate) use rustc_middle::ty::{
-        self, FloatTy, FnSig, Instance, InstanceDef, IntTy, ParamEnv, Ty, TyCtxt, TypeAndMut, TypeFoldable, UintTy,
+        self, FloatTy, Instance, InstanceDef, IntTy, ParamEnv, Ty, TyCtxt, TypeAndMut,
+        TypeFoldable, UintTy,
     };
     pub(crate) use rustc_target::abi::{Abi, LayoutOf, Scalar, Size, VariantIdx};
 
@@ -256,8 +256,6 @@ impl CodegenBackend for CraneliftCodegenBackend {
         };
         let res = driver::codegen_crate(tcx, metadata, need_metadata_module, config);
 
-        rustc_symbol_mangling::test::report_symbol_names(tcx);
-
         res
     }
 
@@ -279,18 +277,14 @@ impl CodegenBackend for CraneliftCodegenBackend {
     ) -> Result<(), ErrorReported> {
         use rustc_codegen_ssa::back::link::link_binary;
 
-        let _timer = sess.prof.generic_activity("link_crate");
+        let target_cpu = crate::target_triple(sess).to_string();
-
+        link_binary::<crate::archive::ArArchiveBuilder<'_>>(
-        sess.time("linking", || {
+            sess,
-            let target_cpu = crate::target_triple(sess).to_string();
+            &codegen_results,
-            link_binary::<crate::archive::ArArchiveBuilder<'_>>(
+            outputs,
-                sess,
+            &codegen_results.crate_name.as_str(),
-                &codegen_results,
+            &target_cpu,
-                outputs,
+        );
-                &codegen_results.crate_name.as_str(),
-                &target_cpu,
-            );
-        });
 
         Ok(())
     }
@@ -345,7 +339,12 @@ fn build_isa(sess: &Session) -> Box<dyn isa::TargetIsa + 'static> {
 
     let flags = settings::Flags::new(flags_builder);
 
-    let mut isa_builder = cranelift_codegen::isa::lookup(target_triple).unwrap();
+    let variant = if cfg!(feature = "oldbe") {
+        cranelift_codegen::isa::BackendVariant::Legacy
+    } else {
+        cranelift_codegen::isa::BackendVariant::MachInst
+    };
+    let mut isa_builder = cranelift_codegen::isa::lookup_variant(target_triple, variant).unwrap();
     // Don't use "haswell", as it implies `has_lzcnt`.macOS CI is still at Ivy Bridge EP, so `lzcnt`
     // is interpreted as `bsr`.
     isa_builder.enable("nehalem").unwrap();

compiler/rustc_codegen_cranelift/src/main_shim.rs

@@ -69,8 +69,8 @@ pub(crate) fn maybe_create_entry_wrapper(
 
         let instance = Instance::mono(tcx, rust_main_def_id).polymorphize(tcx);
 
-        let (main_name, main_sig) =
+        let main_name = tcx.symbol_name(instance).name.to_string();
-            get_function_name_and_sig(tcx, m.isa().triple(), instance, false);
+        let main_sig = get_function_sig(tcx, m.isa().triple(), instance);
         let main_func_id = m
             .declare_function(&main_name, Linkage::Import, &main_sig)
             .unwrap();

compiler/rustc_codegen_cranelift/src/num.rs

@@ -280,7 +280,6 @@ pub(crate) fn codegen_checked_int_binop<'tcx>(
                     (val, fx.bcx.ins().bor(has_underflow, has_overflow))
                 }
                 types::I64 => {
-                    //let val = fx.easy_call("__mulodi4", &[lhs, rhs, overflow_ptr], types::I64);
                     let val = fx.bcx.ins().imul(lhs, rhs);
                     let has_overflow = if !signed {
                         let val_hi = fx.bcx.ins().umulhi(lhs, rhs);

compiler/rustc_codegen_cranelift/src/pretty_clif.rs

@@ -61,7 +61,9 @@ use cranelift_codegen::{
     write::{FuncWriter, PlainWriter},
 };
 
+use rustc_middle::ty::layout::FnAbiExt;
 use rustc_session::config::OutputType;
+use rustc_target::abi::call::FnAbi;
 
 use crate::prelude::*;
 
@@ -78,11 +80,8 @@ impl CommentWriter {
                 format!("symbol {}", tcx.symbol_name(instance).name),
                 format!("instance {:?}", instance),
                 format!(
-                    "sig {:?}",
+                    "abi {:?}",
-                    tcx.normalize_erasing_late_bound_regions(
+                    FnAbi::of_instance(&RevealAllLayoutCx(tcx), instance, &[])
-                        ParamEnv::reveal_all(),
-                        crate::abi::fn_sig_for_fn_abi(tcx, instance)
-                    )
                 ),
                 String::new(),
             ]

compiler/rustc_codegen_cranelift/src/value_and_place.rs

@@ -334,7 +334,9 @@ impl<'tcx> CPlace<'tcx> {
 
         let stack_slot = fx.bcx.create_stack_slot(StackSlotData {
             kind: StackSlotKind::ExplicitSlot,
-            size: u32::try_from(layout.size.bytes()).unwrap(),
+            // FIXME Don't force the size to a multiple of 16 bytes once Cranelift gets a way to
+            // specify stack slot alignment.
+            size: (u32::try_from(layout.size.bytes()).unwrap() + 15) / 16 * 16,
             offset: None,
         });
         CPlace {
@@ -450,64 +452,6 @@ impl<'tcx> CPlace<'tcx> {
         fx: &mut FunctionCx<'_, 'tcx, impl Module>,
         from: CValue<'tcx>,
     ) {
-        fn assert_assignable<'tcx>(
-            fx: &FunctionCx<'_, 'tcx, impl Module>,
-            from_ty: Ty<'tcx>,
-            to_ty: Ty<'tcx>,
-        ) {
-            match (from_ty.kind(), to_ty.kind()) {
-                (ty::Ref(_, a, _), ty::Ref(_, b, _))
-                | (
-                    ty::RawPtr(TypeAndMut { ty: a, mutbl: _ }),
-                    ty::RawPtr(TypeAndMut { ty: b, mutbl: _ }),
-                ) => {
-                    assert_assignable(fx, a, b);
-                }
-                (ty::FnPtr(_), ty::FnPtr(_)) => {
-                    let from_sig = fx.tcx.normalize_erasing_late_bound_regions(
-                        ParamEnv::reveal_all(),
-                        from_ty.fn_sig(fx.tcx),
-                    );
-                    let to_sig = fx.tcx.normalize_erasing_late_bound_regions(
-                        ParamEnv::reveal_all(),
-                        to_ty.fn_sig(fx.tcx),
-                    );
-                    assert_eq!(
-                        from_sig, to_sig,
-                        "Can't write fn ptr with incompatible sig {:?} to place with sig {:?}\n\n{:#?}",
-                        from_sig, to_sig, fx,
-                    );
-                    // fn(&T) -> for<'l> fn(&'l T) is allowed
-                }
-                (&ty::Dynamic(from_traits, _), &ty::Dynamic(to_traits, _)) => {
-                    for (from, to) in from_traits.iter().zip(to_traits) {
-                        let from = fx
-                            .tcx
-                            .normalize_erasing_late_bound_regions(ParamEnv::reveal_all(), from);
-                        let to = fx
-                            .tcx
-                            .normalize_erasing_late_bound_regions(ParamEnv::reveal_all(), to);
-                        assert_eq!(
-                            from, to,
-                            "Can't write trait object of incompatible traits {:?} to place with traits {:?}\n\n{:#?}",
-                            from_traits, to_traits, fx,
-                        );
-                    }
-                    // dyn for<'r> Trait<'r> -> dyn Trait<'_> is allowed
-                }
-                _ => {
-                    assert_eq!(
-                        from_ty,
-                        to_ty,
-                        "Can't write value with incompatible type {:?} to place with type {:?}\n\n{:#?}",
-                        from_ty,
-                        to_ty,
-                        fx,
-                    );
-                }
-            }
-        }
-
         assert_assignable(fx, from.layout().ty, self.layout().ty);
 
         self.write_cvalue_maybe_transmute(fx, from, "write_cvalue");
@@ -556,7 +500,9 @@ impl<'tcx> CPlace<'tcx> {
                     // FIXME do something more efficient for transmutes between vectors and integers.
                     let stack_slot = fx.bcx.create_stack_slot(StackSlotData {
                         kind: StackSlotKind::ExplicitSlot,
-                        size: src_ty.bytes(),
+                        // FIXME Don't force the size to a multiple of 16 bytes once Cranelift gets a way to
+                        // specify stack slot alignment.
+                        size: (src_ty.bytes() + 15) / 16 * 16,
                         offset: None,
                     });
                     let ptr = Pointer::stack_slot(stack_slot);
@@ -794,3 +740,62 @@ impl<'tcx> CPlace<'tcx> {
         }
     }
 }
+
+#[track_caller]
+pub(crate) fn assert_assignable<'tcx>(
+    fx: &FunctionCx<'_, 'tcx, impl Module>,
+    from_ty: Ty<'tcx>,
+    to_ty: Ty<'tcx>,
+) {
+    match (from_ty.kind(), to_ty.kind()) {
+        (ty::Ref(_, a, _), ty::Ref(_, b, _))
+        | (
+            ty::RawPtr(TypeAndMut { ty: a, mutbl: _ }),
+            ty::RawPtr(TypeAndMut { ty: b, mutbl: _ }),
+        ) => {
+            assert_assignable(fx, a, b);
+        }
+        (ty::Ref(_, a, _), ty::RawPtr(TypeAndMut { ty: b, mutbl: _ }))
+        | (ty::RawPtr(TypeAndMut { ty: a, mutbl: _ }), ty::Ref(_, b, _)) => {
+            assert_assignable(fx, a, b);
+        }
+        (ty::FnPtr(_), ty::FnPtr(_)) => {
+            let from_sig = fx.tcx.normalize_erasing_late_bound_regions(
+                ParamEnv::reveal_all(),
+                from_ty.fn_sig(fx.tcx),
+            );
+            let to_sig = fx
+                .tcx
+                .normalize_erasing_late_bound_regions(ParamEnv::reveal_all(), to_ty.fn_sig(fx.tcx));
+            assert_eq!(
+                from_sig, to_sig,
+                "Can't write fn ptr with incompatible sig {:?} to place with sig {:?}\n\n{:#?}",
+                from_sig, to_sig, fx,
+            );
+            // fn(&T) -> for<'l> fn(&'l T) is allowed
+        }
+        (&ty::Dynamic(from_traits, _), &ty::Dynamic(to_traits, _)) => {
+            for (from, to) in from_traits.iter().zip(to_traits) {
+                let from = fx
+                    .tcx
+                    .normalize_erasing_late_bound_regions(ParamEnv::reveal_all(), from);
+                let to = fx
+                    .tcx
+                    .normalize_erasing_late_bound_regions(ParamEnv::reveal_all(), to);
+                assert_eq!(
+                    from, to,
+                    "Can't write trait object of incompatible traits {:?} to place with traits {:?}\n\n{:#?}",
+                    from_traits, to_traits, fx,
+                );
+            }
+            // dyn for<'r> Trait<'r> -> dyn Trait<'_> is allowed
+        }
+        _ => {
+            assert_eq!(
+                from_ty, to_ty,
+                "Can't write value with incompatible type {:?} to place with type {:?}\n\n{:#?}",
+                from_ty, to_ty, fx,
+            );
+        }
+    }
+}

compiler/rustc_codegen_cranelift/test.sh

@@ -1,9 +1,7 @@
 #!/bin/bash
 set -e
 
-export RUSTFLAGS="-Zrun_dsymutil=no"
+./build.sh --sysroot none "$@"
-
-./build.sh --without-sysroot "$@"
 
 rm -r target/out || true
 

compiler/rustc_codegen_ssa/src/base.rs

@@ -12,7 +12,7 @@ use crate::{CachedModuleCodegen, CrateInfo, MemFlags, ModuleCodegen, ModuleKind}
 
 use rustc_attr as attr;
 use rustc_data_structures::fx::FxHashMap;
-use rustc_data_structures::profiling::print_time_passes_entry;
+use rustc_data_structures::profiling::{get_resident_set_size, print_time_passes_entry};
 use rustc_data_structures::sync::{par_iter, ParallelIterator};
 use rustc_hir as hir;
 use rustc_hir::def_id::{LocalDefId, LOCAL_CRATE};
@@ -595,6 +595,7 @@ pub fn codegen_crate<B: ExtraBackendMethods>(
     let mut cgu_reuse = Vec::new();
     let mut pre_compiled_cgus: Option<FxHashMap<usize, _>> = None;
     let mut total_codegen_time = Duration::new(0, 0);
+    let start_rss = tcx.sess.time_passes().then(|| get_resident_set_size());
 
     for (i, cgu) in codegen_units.iter().enumerate() {
         ongoing_codegen.wait_for_signal_to_codegen_item();
@@ -669,7 +670,16 @@ pub fn codegen_crate<B: ExtraBackendMethods>(
 
     // Since the main thread is sometimes blocked during codegen, we keep track
     // -Ztime-passes output manually.
-    print_time_passes_entry(tcx.sess.time_passes(), "codegen_to_LLVM_IR", total_codegen_time);
+    if tcx.sess.time_passes() {
+        let end_rss = get_resident_set_size();
+
+        print_time_passes_entry(
+            "codegen_to_LLVM_IR",
+            total_codegen_time,
+            start_rss.unwrap(),
+            end_rss,
+        );
+    }
 
     ongoing_codegen.check_for_errors(tcx.sess);
 

compiler/rustc_data_structures/src/profiling.rs

@@ -555,13 +555,16 @@ impl<'a> TimingGuard<'a> {
 
 #[must_use]
 pub struct VerboseTimingGuard<'a> {
-    start_and_message: Option<(Instant, String)>,
+    start_and_message: Option<(Instant, Option<usize>, String)>,
     _guard: TimingGuard<'a>,
 }
 
 impl<'a> VerboseTimingGuard<'a> {
     pub fn start(message: Option<String>, _guard: TimingGuard<'a>) -> Self {
-        VerboseTimingGuard { _guard, start_and_message: message.map(|msg| (Instant::now(), msg)) }
+        VerboseTimingGuard {
+            _guard,
+            start_and_message: message.map(|msg| (Instant::now(), get_resident_set_size(), msg)),
+        }
     }
 
     #[inline(always)]
@@ -573,25 +576,42 @@ impl<'a> VerboseTimingGuard<'a> {
 
 impl Drop for VerboseTimingGuard<'_> {
     fn drop(&mut self) {
-        if let Some((start, ref message)) = self.start_and_message {
+        if let Some((start_time, start_rss, ref message)) = self.start_and_message {
-            print_time_passes_entry(true, &message[..], start.elapsed());
+            let end_rss = get_resident_set_size();
+            print_time_passes_entry(&message[..], start_time.elapsed(), start_rss, end_rss);
         }
     }
 }
 
-pub fn print_time_passes_entry(do_it: bool, what: &str, dur: Duration) {
+pub fn print_time_passes_entry(
-    if !do_it {
+    what: &str,
-        return;
+    dur: Duration,
-    }
+    start_rss: Option<usize>,
+    end_rss: Option<usize>,
+) {
+    let rss_to_mb = |rss| (rss as f64 / 1_000_000.0).round() as usize;
 
-    let mem_string = match get_resident() {
+    let mem_string = match (start_rss, end_rss) {
-        Some(n) => {
+        (Some(start_rss), Some(end_rss)) => {
-            let mb = n as f64 / 1_000_000.0;
+            // It's tempting to add the change in RSS from start to end, but its somewhat confusing
-            format!("; rss: {}MB", mb.round() as usize)
+            // and misleading when looking at time-passes output. Consider two adjacent entries:
+            //
+            // time:  10.000; rss start:  1000MB, end:  1000MB, change:     0MB     pass1
+            // time:   5.000; rss start:  2000MB, end:  2000MB, change:     0MB     pass2
+            //
+            // If you're looking for jumps in RSS based on the change column, you miss the fact
+            // that a 1GB jump happened between pass1 and pass2 (supposing pass1 and pass2 actually
+            // occur sequentially and pass1 isn't just nested within pass2). It's easy to imagine
+            // someone missing this or being confused by the fact that the change is zero.
+
+            format!("; rss: {:>5}MB -> {:>5}MB", rss_to_mb(start_rss), rss_to_mb(end_rss))
         }
-        None => String::new(),
+        (Some(start_rss), None) => format!("; rss start: {:>5}MB", rss_to_mb(start_rss)),
+        (None, Some(end_rss)) => format!("; rss end: {:5>}MB", rss_to_mb(end_rss)),
+        (None, None) => String::new(),
     };
-    println!("time: {}{}\t{}", duration_to_secs_str(dur), mem_string, what);
+
+    println!("time: {:>7}{}\t{}", duration_to_secs_str(dur), mem_string, what);
 }
 
 // Hack up our own formatting for the duration to make it easier for scripts
@@ -603,7 +623,7 @@ pub fn duration_to_secs_str(dur: std::time::Duration) -> String {
 // Memory reporting
 cfg_if! {
     if #[cfg(windows)] {
-        fn get_resident() -> Option<usize> {
+        pub fn get_resident_set_size() -> Option<usize> {
             use std::mem::{self, MaybeUninit};
             use winapi::shared::minwindef::DWORD;
             use winapi::um::processthreadsapi::GetCurrentProcess;
@@ -621,7 +641,7 @@ cfg_if! {
             }
         }
     } else if #[cfg(unix)] {
-        fn get_resident() -> Option<usize> {
+        pub fn get_resident_set_size() -> Option<usize> {
             let field = 1;
             let contents = fs::read("/proc/self/statm").ok()?;
             let contents = String::from_utf8(contents).ok()?;
@@ -630,7 +650,7 @@ cfg_if! {
             Some(npages * 4096)
         }
     } else {
-        fn get_resident() -> Option<usize> {
+        pub fn get_resident_set_size() -> Option<usize> {
             None
         }
     }

compiler/rustc_driver/src/lib.rs

@@ -16,7 +16,7 @@ pub extern crate rustc_plugin_impl as plugin;
 
 use rustc_ast as ast;
 use rustc_codegen_ssa::{traits::CodegenBackend, CodegenResults};
-use rustc_data_structures::profiling::print_time_passes_entry;
+use rustc_data_structures::profiling::{get_resident_set_size, print_time_passes_entry};
 use rustc_data_structures::sync::SeqCst;
 use rustc_errors::registry::{InvalidErrorCode, Registry};
 use rustc_errors::{ErrorReported, PResult};
@@ -1312,7 +1312,8 @@ pub fn init_env_logger(env: &str) {
 }
 
 pub fn main() -> ! {
-    let start = Instant::now();
+    let start_time = Instant::now();
+    let start_rss = get_resident_set_size();
     init_rustc_env_logger();
     let mut callbacks = TimePassesCallbacks::default();
     install_ice_hook();
@@ -1330,7 +1331,11 @@ pub fn main() -> ! {
             .collect::<Vec<_>>();
         RunCompiler::new(&args, &mut callbacks).run()
     });
-    // The extra `\t` is necessary to align this label with the others.
+
-    print_time_passes_entry(callbacks.time_passes, "\ttotal", start.elapsed());
+    if callbacks.time_passes {
+        let end_rss = get_resident_set_size();
+        print_time_passes_entry("total", start_time.elapsed(), start_rss, end_rss);
+    }
+
     process::exit(exit_code)
 }

compiler/rustc_infer/src/infer/canonical/query_response.rs

@@ -14,7 +14,7 @@ use crate::infer::canonical::{
 };
 use crate::infer::nll_relate::{NormalizationStrategy, TypeRelating, TypeRelatingDelegate};
 use crate::infer::region_constraints::{Constraint, RegionConstraintData};
-use crate::infer::{InferCtxt, InferOk, InferResult, NLLRegionVariableOrigin};
+use crate::infer::{InferCtxt, InferOk, InferResult, NllRegionVariableOrigin};
 use crate::traits::query::{Fallible, NoSolution};
 use crate::traits::TraitEngine;
 use crate::traits::{Obligation, ObligationCause, PredicateObligation};
@@ -644,7 +644,7 @@ impl<'tcx> TypeRelatingDelegate<'tcx> for QueryTypeRelatingDelegate<'_, 'tcx> {
     }
 
     fn next_existential_region_var(&mut self, from_forall: bool) -> ty::Region<'tcx> {
-        let origin = NLLRegionVariableOrigin::Existential { from_forall };
+        let origin = NllRegionVariableOrigin::Existential { from_forall };
         self.infcx.next_nll_region_var(origin)
     }
 
@@ -654,7 +654,7 @@ impl<'tcx> TypeRelatingDelegate<'tcx> for QueryTypeRelatingDelegate<'_, 'tcx> {
 
     fn generalize_existential(&mut self, universe: ty::UniverseIndex) -> ty::Region<'tcx> {
         self.infcx.next_nll_region_var_in_universe(
-            NLLRegionVariableOrigin::Existential { from_forall: false },
+            NllRegionVariableOrigin::Existential { from_forall: false },
             universe,
         )
     }

compiler/rustc_infer/src/infer/error_reporting/mod.rs

@@ -1661,6 +1661,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         debug!("exp_found {:?} terr {:?}", exp_found, terr);
         if let Some(exp_found) = exp_found {
             self.suggest_as_ref_where_appropriate(span, &exp_found, diag);
+            self.suggest_accessing_field_where_appropriate(cause, &exp_found, diag);
             self.suggest_await_on_expect_found(cause, span, &exp_found, diag);
         }
 
@@ -1819,6 +1820,53 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         }
     }
 
+    fn suggest_accessing_field_where_appropriate(
+        &self,
+        cause: &ObligationCause<'tcx>,
+        exp_found: &ty::error::ExpectedFound<Ty<'tcx>>,
+        diag: &mut DiagnosticBuilder<'tcx>,
+    ) {
+        debug!(
+            "suggest_accessing_field_where_appropriate(cause={:?}, exp_found={:?})",
+            cause, exp_found
+        );
+        if let ty::Adt(expected_def, expected_substs) = exp_found.expected.kind() {
+            if expected_def.is_enum() {
+                return;
+            }
+
+            if let Some((name, ty)) = expected_def
+                .non_enum_variant()
+                .fields
+                .iter()
+                .filter(|field| field.vis.is_accessible_from(field.did, self.tcx))
+                .map(|field| (field.ident.name, field.ty(self.tcx, expected_substs)))
+                .find(|(_, ty)| ty::TyS::same_type(ty, exp_found.found))
+            {
+                if let ObligationCauseCode::Pattern { span: Some(span), .. } = cause.code {
+                    if let Ok(snippet) = self.tcx.sess.source_map().span_to_snippet(span) {
+                        let suggestion = if expected_def.is_struct() {
+                            format!("{}.{}", snippet, name)
+                        } else if expected_def.is_union() {
+                            format!("unsafe {{ {}.{} }}", snippet, name)
+                        } else {
+                            return;
+                        };
+                        diag.span_suggestion(
+                            span,
+                            &format!(
+                                "you might have meant to use field `{}` of type `{}`",
+                                name, ty
+                            ),
+                            suggestion,
+                            Applicability::MaybeIncorrect,
+                        );
+                    }
+                }
+            }
+        }
+    }
+
     /// When encountering a case where `.as_ref()` on a `Result` or `Option` would be appropriate,
     /// suggests it.
     fn suggest_as_ref_where_appropriate(
@@ -2342,7 +2390,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                 let var_name = self.tcx.hir().name(upvar_id.var_path.hir_id);
                 format!(" for capture of `{}` by closure", var_name)
             }
-            infer::NLL(..) => bug!("NLL variable found in lexical phase"),
+            infer::Nll(..) => bug!("NLL variable found in lexical phase"),
         };
 
         struct_span_err!(

compiler/rustc_infer/src/infer/mod.rs

@@ -458,11 +458,11 @@ pub enum RegionVariableOrigin {
 
     /// This origin is used for the inference variables that we create
     /// during NLL region processing.
-    NLL(NLLRegionVariableOrigin),
+    Nll(NllRegionVariableOrigin),
 }
 
 #[derive(Copy, Clone, Debug)]
-pub enum NLLRegionVariableOrigin {
+pub enum NllRegionVariableOrigin {
     /// During NLL region processing, we create variables for free
     /// regions that we encounter in the function signature and
     /// elsewhere. This origin indices we've got one of those.
@@ -1078,17 +1078,17 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
     }
 
     /// Just a convenient wrapper of `next_region_var` for using during NLL.
-    pub fn next_nll_region_var(&self, origin: NLLRegionVariableOrigin) -> ty::Region<'tcx> {
+    pub fn next_nll_region_var(&self, origin: NllRegionVariableOrigin) -> ty::Region<'tcx> {
-        self.next_region_var(RegionVariableOrigin::NLL(origin))
+        self.next_region_var(RegionVariableOrigin::Nll(origin))
     }
 
     /// Just a convenient wrapper of `next_region_var` for using during NLL.
     pub fn next_nll_region_var_in_universe(
         &self,
-        origin: NLLRegionVariableOrigin,
+        origin: NllRegionVariableOrigin,
         universe: ty::UniverseIndex,
     ) -> ty::Region<'tcx> {
-        self.next_region_var_in_universe(RegionVariableOrigin::NLL(origin), universe)
+        self.next_region_var_in_universe(RegionVariableOrigin::Nll(origin), universe)
     }
 
     pub fn var_for_def(&self, span: Span, param: &ty::GenericParamDef) -> GenericArg<'tcx> {
@@ -1770,7 +1770,7 @@ impl RegionVariableOrigin {
             | LateBoundRegion(a, ..)
             | UpvarRegion(_, a) => a,
             BoundRegionInCoherence(_) => rustc_span::DUMMY_SP,
-            NLL(..) => bug!("NLL variable used with `span`"),
+            Nll(..) => bug!("NLL variable used with `span`"),
         }
     }
 }

compiler/rustc_lint/src/nonstandard_style.rs

@@ -56,8 +56,19 @@ declare_lint! {
 
 declare_lint_pass!(NonCamelCaseTypes => [NON_CAMEL_CASE_TYPES]);
 
+/// Some unicode characters *have* case, are considered upper case or lower case, but they *can't*
+/// be upper cased or lower cased. For the purposes of the lint suggestion, we care about being able
+/// to change the char's case.
 fn char_has_case(c: char) -> bool {
-    c.is_lowercase() || c.is_uppercase()
+    let mut l = c.to_lowercase();
+    let mut u = c.to_uppercase();
+    while let Some(l) = l.next() {
+        match u.next() {
+            Some(u) if l != u => return true,
+            _ => {}
+        }
+    }
+    u.next().is_some()
 }
 
 fn is_camel_case(name: &str) -> bool {
@@ -138,6 +149,8 @@ impl NonCamelCaseTypes {
                         to_camel_case(name),
                         Applicability::MaybeIncorrect,
                     );
+                } else {
+                    err.span_label(ident.span, "should have an UpperCamelCase name");
                 }
 
                 err.emit();
@@ -299,6 +312,8 @@ impl NonSnakeCase {
                     } else {
                         err.help(&format!("convert the identifier to snake case: `{}`", sc));
                     }
+                } else {
+                    err.span_label(ident.span, "should have a snake_case name");
                 }
 
                 err.emit();
@@ -477,6 +492,8 @@ impl NonUpperCaseGlobals {
                         uc,
                         Applicability::MaybeIncorrect,
                     );
+                } else {
+                    err.span_label(ident.span, "should have an UPPER_CASE name");
                 }
 
                 err.emit();

compiler/rustc_mir/src/borrow_check/diagnostics/explain_borrow.rs

@@ -5,7 +5,7 @@ use std::collections::VecDeque;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::{Applicability, DiagnosticBuilder};
 use rustc_index::vec::IndexVec;
-use rustc_infer::infer::NLLRegionVariableOrigin;
+use rustc_infer::infer::NllRegionVariableOrigin;
 use rustc_middle::mir::{
     Body, CastKind, ConstraintCategory, FakeReadCause, Local, Location, Operand, Place, Rvalue,
     Statement, StatementKind, TerminatorKind,
@@ -258,7 +258,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         let (category, from_closure, span) = self.regioncx.best_blame_constraint(
             &self.body,
             borrow_region,
-            NLLRegionVariableOrigin::FreeRegion,
+            NllRegionVariableOrigin::FreeRegion,
             |r| self.regioncx.provides_universal_region(r, borrow_region, outlived_region),
         );
 

compiler/rustc_mir/src/borrow_check/diagnostics/region_errors.rs

@@ -3,7 +3,7 @@
 use rustc_errors::{Applicability, DiagnosticBuilder};
 use rustc_infer::infer::{
     error_reporting::nice_region_error::NiceRegionError,
-    error_reporting::unexpected_hidden_region_diagnostic, NLLRegionVariableOrigin,
+    error_reporting::unexpected_hidden_region_diagnostic, NllRegionVariableOrigin,
 };
 use rustc_middle::mir::{ConstraintCategory, ReturnConstraint};
 use rustc_middle::ty::subst::Subst;
@@ -75,13 +75,13 @@ crate enum RegionErrorKind<'tcx> {
         /// The region element that erroneously must be outlived by `longer_fr`.
         error_element: RegionElement,
         /// The origin of the placeholder region.
-        fr_origin: NLLRegionVariableOrigin,
+        fr_origin: NllRegionVariableOrigin,
     },
 
     /// Any other lifetime error.
     RegionError {
         /// The origin of the region.
-        fr_origin: NLLRegionVariableOrigin,
+        fr_origin: NllRegionVariableOrigin,
         /// The region that should outlive `shorter_fr`.
         longer_fr: RegionVid,
         /// The region that should be shorter, but we can't prove it.
@@ -269,7 +269,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
     pub(in crate::borrow_check) fn report_region_error(
         &mut self,
         fr: RegionVid,
-        fr_origin: NLLRegionVariableOrigin,
+        fr_origin: NllRegionVariableOrigin,
         outlived_fr: RegionVid,
         outlives_suggestion: &mut OutlivesSuggestionBuilder,
     ) {

compiler/rustc_mir/src/borrow_check/region_infer/dump_mir.rs

@@ -5,7 +5,7 @@
 
 use super::{OutlivesConstraint, RegionInferenceContext};
 use crate::borrow_check::type_check::Locations;
-use rustc_infer::infer::NLLRegionVariableOrigin;
+use rustc_infer::infer::NllRegionVariableOrigin;
 use rustc_middle::ty::TyCtxt;
 use std::io::{self, Write};
 
@@ -20,7 +20,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
         writeln!(out, "| Free Region Mapping")?;
 
         for region in self.regions() {
-            if let NLLRegionVariableOrigin::FreeRegion = self.definitions[region].origin {
+            if let NllRegionVariableOrigin::FreeRegion = self.definitions[region].origin {
                 let classification = self.universal_regions.region_classification(region).unwrap();
                 let outlived_by = self.universal_region_relations.regions_outlived_by(region);
                 writeln!(

compiler/rustc_mir/src/borrow_check/region_infer/mod.rs

@@ -9,7 +9,7 @@ use rustc_hir::def_id::DefId;
 use rustc_index::vec::IndexVec;
 use rustc_infer::infer::canonical::QueryOutlivesConstraint;
 use rustc_infer::infer::region_constraints::{GenericKind, VarInfos, VerifyBound};
-use rustc_infer::infer::{InferCtxt, NLLRegionVariableOrigin, RegionVariableOrigin};
+use rustc_infer::infer::{InferCtxt, NllRegionVariableOrigin, RegionVariableOrigin};
 use rustc_middle::mir::{
     Body, ClosureOutlivesRequirement, ClosureOutlivesSubject, ClosureRegionRequirements,
     ConstraintCategory, Local, Location, ReturnConstraint,
@@ -143,9 +143,9 @@ pub(crate) struct AppliedMemberConstraint {
 
 pub(crate) struct RegionDefinition<'tcx> {
     /// What kind of variable is this -- a free region? existential
-    /// variable? etc. (See the `NLLRegionVariableOrigin` for more
+    /// variable? etc. (See the `NllRegionVariableOrigin` for more
     /// info.)
-    pub(in crate::borrow_check) origin: NLLRegionVariableOrigin,
+    pub(in crate::borrow_check) origin: NllRegionVariableOrigin,
 
     /// Which universe is this region variable defined in? This is
     /// most often `ty::UniverseIndex::ROOT`, but when we encounter
@@ -451,7 +451,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
             let scc = self.constraint_sccs.scc(variable);
 
             match self.definitions[variable].origin {
-                NLLRegionVariableOrigin::FreeRegion => {
+                NllRegionVariableOrigin::FreeRegion => {
                     // For each free, universally quantified region X:
 
                     // Add all nodes in the CFG to liveness constraints
@@ -462,7 +462,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
                     self.scc_values.add_element(scc, variable);
                 }
 
-                NLLRegionVariableOrigin::Placeholder(placeholder) => {
+                NllRegionVariableOrigin::Placeholder(placeholder) => {
                     // Each placeholder region is only visible from
                     // its universe `ui` and its extensions. So we
                     // can't just add it into `scc` unless the
@@ -480,8 +480,8 @@ impl<'tcx> RegionInferenceContext<'tcx> {
                     }
                 }
 
-                NLLRegionVariableOrigin::RootEmptyRegion
+                NllRegionVariableOrigin::RootEmptyRegion
-                | NLLRegionVariableOrigin::Existential { .. } => {
+                | NllRegionVariableOrigin::Existential { .. } => {
                     // For existential, regions, nothing to do.
                 }
             }
@@ -1348,7 +1348,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
     ) {
         for (fr, fr_definition) in self.definitions.iter_enumerated() {
             match fr_definition.origin {
-                NLLRegionVariableOrigin::FreeRegion => {
+                NllRegionVariableOrigin::FreeRegion => {
                     // Go through each of the universal regions `fr` and check that
                     // they did not grow too large, accumulating any requirements
                     // for our caller into the `outlives_requirements` vector.
@@ -1360,12 +1360,12 @@ impl<'tcx> RegionInferenceContext<'tcx> {
                     );
                 }
 
-                NLLRegionVariableOrigin::Placeholder(placeholder) => {
+                NllRegionVariableOrigin::Placeholder(placeholder) => {
                     self.check_bound_universal_region(fr, placeholder, errors_buffer);
                 }
 
-                NLLRegionVariableOrigin::RootEmptyRegion
+                NllRegionVariableOrigin::RootEmptyRegion
-                | NLLRegionVariableOrigin::Existential { .. } => {
+                | NllRegionVariableOrigin::Existential { .. } => {
                     // nothing to check here
                 }
             }
@@ -1449,7 +1449,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
                 errors_buffer.push(RegionErrorKind::RegionError {
                     longer_fr: *longer_fr,
                     shorter_fr: *shorter_fr,
-                    fr_origin: NLLRegionVariableOrigin::FreeRegion,
+                    fr_origin: NllRegionVariableOrigin::FreeRegion,
                     is_reported: true,
                 });
             }
@@ -1459,16 +1459,16 @@ impl<'tcx> RegionInferenceContext<'tcx> {
         // a more complete picture on how to separate this responsibility.
         for (fr, fr_definition) in self.definitions.iter_enumerated() {
             match fr_definition.origin {
-                NLLRegionVariableOrigin::FreeRegion => {
+                NllRegionVariableOrigin::FreeRegion => {
                     // handled by polonius above
                 }
 
-                NLLRegionVariableOrigin::Placeholder(placeholder) => {
+                NllRegionVariableOrigin::Placeholder(placeholder) => {
                     self.check_bound_universal_region(fr, placeholder, errors_buffer);
                 }
 
-                NLLRegionVariableOrigin::RootEmptyRegion
+                NllRegionVariableOrigin::RootEmptyRegion
-                | NLLRegionVariableOrigin::Existential { .. } => {
+                | NllRegionVariableOrigin::Existential { .. } => {
                     // nothing to check here
                 }
             }
@@ -1516,7 +1516,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
                 errors_buffer.push(RegionErrorKind::RegionError {
                     longer_fr,
                     shorter_fr: representative,
-                    fr_origin: NLLRegionVariableOrigin::FreeRegion,
+                    fr_origin: NllRegionVariableOrigin::FreeRegion,
                     is_reported: true,
                 });
             }
@@ -1539,7 +1539,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
                 errors_buffer.push(RegionErrorKind::RegionError {
                     longer_fr,
                     shorter_fr,
-                    fr_origin: NLLRegionVariableOrigin::FreeRegion,
+                    fr_origin: NllRegionVariableOrigin::FreeRegion,
                     is_reported: !error_reported,
                 });
 
@@ -1597,7 +1597,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
                 let blame_span_category = self.find_outlives_blame_span(
                     body,
                     longer_fr,
-                    NLLRegionVariableOrigin::FreeRegion,
+                    NllRegionVariableOrigin::FreeRegion,
                     shorter_fr,
                 );
 
@@ -1656,7 +1656,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
         errors_buffer.push(RegionErrorKind::BoundUniversalRegionError {
             longer_fr,
             error_element,
-            fr_origin: NLLRegionVariableOrigin::Placeholder(placeholder),
+            fr_origin: NllRegionVariableOrigin::Placeholder(placeholder),
         });
     }
 
@@ -1732,7 +1732,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
         debug!("cannot_name_value_of(r1={:?}, r2={:?})", r1, r2);
 
         match self.definitions[r2].origin {
-            NLLRegionVariableOrigin::Placeholder(placeholder) => {
+            NllRegionVariableOrigin::Placeholder(placeholder) => {
                 let universe1 = self.definitions[r1].universe;
                 debug!(
                     "cannot_name_value_of: universe1={:?} placeholder={:?}",
@@ -1741,9 +1741,9 @@ impl<'tcx> RegionInferenceContext<'tcx> {
                 universe1.cannot_name(placeholder.universe)
             }
 
-            NLLRegionVariableOrigin::RootEmptyRegion
+            NllRegionVariableOrigin::RootEmptyRegion
-            | NLLRegionVariableOrigin::FreeRegion
+            | NllRegionVariableOrigin::FreeRegion
-            | NLLRegionVariableOrigin::Existential { .. } => false,
+            | NllRegionVariableOrigin::Existential { .. } => false,
         }
     }
 
@@ -1771,7 +1771,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
         &self,
         body: &Body<'tcx>,
         fr1: RegionVid,
-        fr1_origin: NLLRegionVariableOrigin,
+        fr1_origin: NllRegionVariableOrigin,
         fr2: RegionVid,
     ) -> (ConstraintCategory, Span) {
         let (category, _, span) = self.best_blame_constraint(body, fr1, fr1_origin, |r| {
@@ -1933,7 +1933,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
                 .definitions
                 .iter_enumerated()
                 .find_map(|(r, definition)| match definition.origin {
-                    NLLRegionVariableOrigin::Placeholder(p) if p == error_placeholder => Some(r),
+                    NllRegionVariableOrigin::Placeholder(p) if p == error_placeholder => Some(r),
                     _ => None,
                 })
                 .unwrap(),
@@ -1965,7 +1965,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
         &self,
         body: &Body<'tcx>,
         from_region: RegionVid,
-        from_region_origin: NLLRegionVariableOrigin,
+        from_region_origin: NllRegionVariableOrigin,
         target_test: impl Fn(RegionVid) -> bool,
     ) -> (ConstraintCategory, bool, Span) {
         debug!(
@@ -2059,11 +2059,11 @@ impl<'tcx> RegionInferenceContext<'tcx> {
         //
         // and here we prefer to blame the source (the y = x statement).
         let blame_source = match from_region_origin {
-            NLLRegionVariableOrigin::FreeRegion
+            NllRegionVariableOrigin::FreeRegion
-            | NLLRegionVariableOrigin::Existential { from_forall: false } => true,
+            | NllRegionVariableOrigin::Existential { from_forall: false } => true,
-            NLLRegionVariableOrigin::RootEmptyRegion
+            NllRegionVariableOrigin::RootEmptyRegion
-            | NLLRegionVariableOrigin::Placeholder(_)
+            | NllRegionVariableOrigin::Placeholder(_)
-            | NLLRegionVariableOrigin::Existential { from_forall: true } => false,
+            | NllRegionVariableOrigin::Existential { from_forall: true } => false,
         };
 
         let find_region = |i: &usize| {
@@ -2144,8 +2144,8 @@ impl<'tcx> RegionDefinition<'tcx> {
         // `init_universal_regions`.
 
         let origin = match rv_origin {
-            RegionVariableOrigin::NLL(origin) => origin,
+            RegionVariableOrigin::Nll(origin) => origin,
-            _ => NLLRegionVariableOrigin::Existential { from_forall: false },
+            _ => NllRegionVariableOrigin::Existential { from_forall: false },
         };
 
         Self { origin, universe, external_name: None }

compiler/rustc_mir/src/borrow_check/renumber.rs

@@ -1,5 +1,5 @@
 use rustc_index::vec::IndexVec;
-use rustc_infer::infer::{InferCtxt, NLLRegionVariableOrigin};
+use rustc_infer::infer::{InferCtxt, NllRegionVariableOrigin};
 use rustc_middle::mir::visit::{MutVisitor, TyContext};
 use rustc_middle::mir::{Body, Location, PlaceElem, Promoted};
 use rustc_middle::ty::subst::SubstsRef;
@@ -15,7 +15,7 @@ pub fn renumber_mir<'tcx>(
     debug!("renumber_mir()");
     debug!("renumber_mir: body.arg_count={:?}", body.arg_count);
 
-    let mut visitor = NLLVisitor { infcx };
+    let mut visitor = NllVisitor { infcx };
 
     for body in promoted.iter_mut() {
         visitor.visit_body(body);
@@ -33,16 +33,16 @@ where
     debug!("renumber_regions(value={:?})", value);
 
     infcx.tcx.fold_regions(value, &mut false, |_region, _depth| {
-        let origin = NLLRegionVariableOrigin::Existential { from_forall: false };
+        let origin = NllRegionVariableOrigin::Existential { from_forall: false };
         infcx.next_nll_region_var(origin)
     })
 }
 
-struct NLLVisitor<'a, 'tcx> {
+struct NllVisitor<'a, 'tcx> {
     infcx: &'a InferCtxt<'a, 'tcx>,
 }
 
-impl<'a, 'tcx> NLLVisitor<'a, 'tcx> {
+impl<'a, 'tcx> NllVisitor<'a, 'tcx> {
     fn renumber_regions<T>(&mut self, value: T) -> T
     where
         T: TypeFoldable<'tcx>,
@@ -51,7 +51,7 @@ impl<'a, 'tcx> NLLVisitor<'a, 'tcx> {
     }
 }
 
-impl<'a, 'tcx> MutVisitor<'tcx> for NLLVisitor<'a, 'tcx> {
+impl<'a, 'tcx> MutVisitor<'tcx> for NllVisitor<'a, 'tcx> {
     fn tcx(&self) -> TyCtxt<'tcx> {
         self.infcx.tcx
     }

compiler/rustc_mir/src/borrow_check/type_check/mod.rs

@@ -16,7 +16,7 @@ use rustc_infer::infer::canonical::QueryRegionConstraints;
 use rustc_infer::infer::outlives::env::RegionBoundPairs;
 use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
 use rustc_infer::infer::{
-    InferCtxt, InferOk, LateBoundRegionConversionTime, NLLRegionVariableOrigin,
+    InferCtxt, InferOk, LateBoundRegionConversionTime, NllRegionVariableOrigin,
 };
 use rustc_middle::mir::tcx::PlaceTy;
 use rustc_middle::mir::visit::{NonMutatingUseContext, PlaceContext, Visitor};
@@ -872,7 +872,7 @@ impl MirTypeckRegionConstraints<'tcx> {
         match self.placeholder_index_to_region.get(placeholder_index) {
             Some(&v) => v,
             None => {
-                let origin = NLLRegionVariableOrigin::Placeholder(placeholder);
+                let origin = NllRegionVariableOrigin::Placeholder(placeholder);
                 let region = infcx.next_nll_region_var_in_universe(origin, placeholder.universe);
                 self.placeholder_index_to_region.push(region);
                 region

compiler/rustc_mir/src/borrow_check/type_check/relate_tys.rs

@@ -1,5 +1,5 @@
 use rustc_infer::infer::nll_relate::{NormalizationStrategy, TypeRelating, TypeRelatingDelegate};
-use rustc_infer::infer::{InferCtxt, NLLRegionVariableOrigin};
+use rustc_infer::infer::{InferCtxt, NllRegionVariableOrigin};
 use rustc_middle::mir::ConstraintCategory;
 use rustc_middle::ty::relate::TypeRelation;
 use rustc_middle::ty::{self, Const, Ty};
@@ -64,7 +64,7 @@ impl TypeRelatingDelegate<'tcx> for NllTypeRelatingDelegate<'_, '_, 'tcx> {
 
     fn next_existential_region_var(&mut self, from_forall: bool) -> ty::Region<'tcx> {
         if self.borrowck_context.is_some() {
-            let origin = NLLRegionVariableOrigin::Existential { from_forall };
+            let origin = NllRegionVariableOrigin::Existential { from_forall };
             self.infcx.next_nll_region_var(origin)
         } else {
             self.infcx.tcx.lifetimes.re_erased
@@ -81,7 +81,7 @@ impl TypeRelatingDelegate<'tcx> for NllTypeRelatingDelegate<'_, '_, 'tcx> {
 
     fn generalize_existential(&mut self, universe: ty::UniverseIndex) -> ty::Region<'tcx> {
         self.infcx.next_nll_region_var_in_universe(
-            NLLRegionVariableOrigin::Existential { from_forall: false },
+            NllRegionVariableOrigin::Existential { from_forall: false },
             universe,
         )
     }

compiler/rustc_mir/src/borrow_check/universal_regions.rs

@@ -20,7 +20,7 @@ use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_hir::lang_items::LangItem;
 use rustc_hir::{BodyOwnerKind, HirId};
 use rustc_index::vec::{Idx, IndexVec};
-use rustc_infer::infer::{InferCtxt, NLLRegionVariableOrigin};
+use rustc_infer::infer::{InferCtxt, NllRegionVariableOrigin};
 use rustc_middle::ty::fold::TypeFoldable;
 use rustc_middle::ty::subst::{InternalSubsts, Subst, SubstsRef};
 use rustc_middle::ty::{self, RegionVid, Ty, TyCtxt};
@@ -393,7 +393,7 @@ struct UniversalRegionsBuilder<'cx, 'tcx> {
     param_env: ty::ParamEnv<'tcx>,
 }
 
-const FR: NLLRegionVariableOrigin = NLLRegionVariableOrigin::FreeRegion;
+const FR: NllRegionVariableOrigin = NllRegionVariableOrigin::FreeRegion;
 
 impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
     fn build(self) -> UniversalRegions<'tcx> {
@@ -486,7 +486,7 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
 
         let root_empty = self
             .infcx
-            .next_nll_region_var(NLLRegionVariableOrigin::RootEmptyRegion)
+            .next_nll_region_var(NllRegionVariableOrigin::RootEmptyRegion)
             .to_region_vid();
 
         UniversalRegions {
@@ -647,7 +647,7 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
 trait InferCtxtExt<'tcx> {
     fn replace_free_regions_with_nll_infer_vars<T>(
         &self,
-        origin: NLLRegionVariableOrigin,
+        origin: NllRegionVariableOrigin,
         value: T,
     ) -> T
     where
@@ -655,7 +655,7 @@ trait InferCtxtExt<'tcx> {
 
     fn replace_bound_regions_with_nll_infer_vars<T>(
         &self,
-        origin: NLLRegionVariableOrigin,
+        origin: NllRegionVariableOrigin,
         all_outlive_scope: LocalDefId,
         value: ty::Binder<T>,
         indices: &mut UniversalRegionIndices<'tcx>,
@@ -673,7 +673,7 @@ trait InferCtxtExt<'tcx> {
 impl<'cx, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'cx, 'tcx> {
     fn replace_free_regions_with_nll_infer_vars<T>(
         &self,
-        origin: NLLRegionVariableOrigin,
+        origin: NllRegionVariableOrigin,
         value: T,
     ) -> T
     where
@@ -684,7 +684,7 @@ impl<'cx, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'cx, 'tcx> {
 
     fn replace_bound_regions_with_nll_infer_vars<T>(
         &self,
-        origin: NLLRegionVariableOrigin,
+        origin: NllRegionVariableOrigin,
         all_outlive_scope: LocalDefId,
         value: ty::Binder<T>,
         indices: &mut UniversalRegionIndices<'tcx>,

compiler/rustc_mir_build/src/build/matches/mod.rs

@@ -82,8 +82,8 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
     /// visible through borrow checking. False edges ensure that the CFG as
     /// seen by borrow checking doesn't encode this. False edges are added:
     ///
-    /// * From each prebinding block to the next prebinding block.
+    /// * From each pre-binding block to the next pre-binding block.
-    /// * From each otherwise block to the next prebinding block.
+    /// * From each otherwise block to the next pre-binding block.
     crate fn match_expr(
         &mut self,
         destination: Place<'tcx>,
@@ -630,10 +630,10 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
 
 #[derive(Debug)]
 pub(super) struct Candidate<'pat, 'tcx> {
-    /// `Span` of the original pattern that gave rise to this candidate
+    /// [`Span`] of the original pattern that gave rise to this candidate.
     span: Span,
 
-    /// This `Candidate` has a guard.
+    /// Whether this `Candidate` has a guard.
     has_guard: bool,
 
     /// All of these must be satisfied...
@@ -645,14 +645,15 @@ pub(super) struct Candidate<'pat, 'tcx> {
     /// ...and these types asserted...
     ascriptions: Vec<Ascription<'tcx>>,
 
-    /// ... and if this is non-empty, one of these subcandidates also has to match ...
+    /// ...and if this is non-empty, one of these subcandidates also has to match...
     subcandidates: Vec<Candidate<'pat, 'tcx>>,
 
-    /// ...and the guard must be evaluated, if false branch to Block...
+    /// ...and the guard must be evaluated; if it's `false` then branch to `otherwise_block`.
     otherwise_block: Option<BasicBlock>,
 
-    /// ...and the blocks for add false edges between candidates
+    /// The block before the `bindings` have been established.
     pre_binding_block: Option<BasicBlock>,
+    /// The pre-binding block of the next candidate.
     next_candidate_pre_binding_block: Option<BasicBlock>,
 }
 
@@ -737,18 +738,19 @@ crate struct MatchPair<'pat, 'tcx> {
     pattern: &'pat Pat<'tcx>,
 }
 
+/// See [`Test`] for more.
 #[derive(Clone, Debug, PartialEq)]
 enum TestKind<'tcx> {
-    /// Test the branches of enum.
+    /// Test what enum variant a value is.
     Switch {
-        /// The enum being tested
+        /// The enum type being tested.
         adt_def: &'tcx ty::AdtDef,
         /// The set of variants that we should create a branch for. We also
         /// create an additional "otherwise" case.
         variants: BitSet<VariantIdx>,
     },
 
-    /// Test what value an `integer`, `bool` or `char` has.
+    /// Test what value an integer, `bool`, or `char` has.
     SwitchInt {
         /// The type of the value that we're testing.
         switch_ty: Ty<'tcx>,
@@ -756,7 +758,7 @@ enum TestKind<'tcx> {
         ///
         /// For integers and `char`s we create a branch to each of the values in
         /// `options`, as well as an "otherwise" branch for all other values, even
-        /// in the (rare) case that options is exhaustive.
+        /// in the (rare) case that `options` is exhaustive.
         ///
         /// For `bool` we always generate two edges, one for `true` and one for
         /// `false`.
@@ -776,17 +778,21 @@ enum TestKind<'tcx> {
     /// Test whether the value falls within an inclusive or exclusive range
     Range(PatRange<'tcx>),
 
-    /// Test length of the slice is equal to len
+    /// Test that the length of the slice is equal to `len`.
     Len { len: u64, op: BinOp },
 }
 
+/// A test to perform to determine which [`Candidate`] matches a value.
+///
+/// [`Test`] is just the test to perform; it does not include the value
+/// to be tested.
 #[derive(Debug)]
 crate struct Test<'tcx> {
     span: Span,
     kind: TestKind<'tcx>,
 }
 
-/// ArmHasGuard is isomorphic to a boolean flag. It indicates whether
+/// `ArmHasGuard` is a wrapper around a boolean flag. It indicates whether
 /// a match arm has a guard expression attached to it.
 #[derive(Copy, Clone, Debug)]
 crate struct ArmHasGuard(crate bool);
@@ -801,27 +807,27 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
     /// candidates are sorted such that the first item in the list
     /// has the highest priority. When a candidate is found to match
     /// the value, we will set and generate a branch to the appropriate
-    /// prebinding block.
+    /// pre-binding block.
     ///
     /// If we find that *NONE* of the candidates apply, we branch to the
     /// `otherwise_block`, setting it to `Some` if required. In principle, this
     /// means that the input list was not exhaustive, though at present we
     /// sometimes are not smart enough to recognize all exhaustive inputs.
     ///
-    /// It might be surprising that the input can be inexhaustive.
+    /// It might be surprising that the input can be non-exhaustive.
     /// Indeed, initially, it is not, because all matches are
     /// exhaustive in Rust. But during processing we sometimes divide
     /// up the list of candidates and recurse with a non-exhaustive
     /// list. This is important to keep the size of the generated code
-    /// under control. See `test_candidates` for more details.
+    /// under control. See [`Builder::test_candidates`] for more details.
     ///
-    /// If `fake_borrows` is Some, then places which need fake borrows
+    /// If `fake_borrows` is `Some`, then places which need fake borrows
     /// will be added to it.
     ///
     /// For an example of a case where we set `otherwise_block`, even for an
-    /// exhaustive match consider:
+    /// exhaustive match, consider:
     ///
-    /// ```rust
+    /// ```
     /// match x {
     ///     (true, true) => (),
     ///     (_, false) => (),
@@ -830,8 +836,8 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
     /// ```
     ///
     /// For this match, we check if `x.0` matches `true` (for the first
-    /// arm). If that's false, we check `x.1`. If it's `true` we check if
+    /// arm). If it doesn't match, we check `x.1`. If `x.1` is `true` we check
-    /// `x.0` matches `false` (for the third arm). In the (impossible at
+    /// if `x.0` matches `false` (for the third arm). In the (impossible at
     /// runtime) case when `x.0` is now `true`, we branch to
     /// `otherwise_block`.
     fn match_candidates<'pat>(
@@ -938,26 +944,31 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         );
     }
 
-    /// Link up matched candidates. For example, if we have something like
+    /// Link up matched candidates.
-    /// this:
+    ///
+    /// For example, if we have something like this:
     ///
     /// ```rust
     /// ...
-    /// Some(x) if cond => ...
+    /// Some(x) if cond1 => ...
     /// Some(x) => ...
-    /// Some(x) if cond => ...
+    /// Some(x) if cond2 => ...
     /// ...
     /// ```
     ///
     /// We generate real edges from:
-    /// * `start_block` to the `prebinding_block` of the first pattern,
-    /// * the otherwise block of the first pattern to the second pattern,
-    /// * the otherwise block of the third pattern to the a block with an
-    ///   Unreachable terminator.
     ///
-    /// As well as that we add fake edges from the otherwise blocks to the
+    /// * `start_block` to the [pre-binding block] of the first pattern,
-    /// prebinding block of the next candidate in the original set of
+    /// * the [otherwise block] of the first pattern to the second pattern,
+    /// * the [otherwise block] of the third pattern to a block with an
+    ///   [`Unreachable` terminator](TerminatorKind::Unreachable).
+    ///
+    /// In addition, we add fake edges from the otherwise blocks to the
+    /// pre-binding block of the next candidate in the original set of
     /// candidates.
+    ///
+    /// [pre-binding block]: Candidate::pre_binding_block
+    /// [otherwise block]: Candidate::otherwise_block
     fn select_matched_candidates(
         &mut self,
         matched_candidates: &mut [&mut Candidate<'_, 'tcx>],
@@ -1044,7 +1055,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
     /// forwards to [Builder::test_candidates].
     ///
     /// Given a pattern `(P | Q, R | S)` we (in principle) generate a CFG like
-    /// so
+    /// so:
     ///
     /// ```text
     /// [ start ]
@@ -1214,10 +1225,11 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
     /// This is the most subtle part of the matching algorithm. At
     /// this point, the input candidates have been fully simplified,
     /// and so we know that all remaining match-pairs require some
-    /// sort of test. To decide what test to do, we take the highest
+    /// sort of test. To decide what test to perform, we take the highest
-    /// priority candidate (last one in the list) and extract the
+    /// priority candidate (the first one in the list, as of January 2021)
-    /// first match-pair from the list. From this we decide what kind
+    /// and extract the first match-pair from the list. From this we decide
-    /// of test is needed using `test`, defined in the `test` module.
+    /// what kind of test is needed using [`Builder::test`], defined in the
+    /// [`test` module](mod@test).
     ///
     /// *Note:* taking the first match pair is somewhat arbitrary, and
     /// we might do better here by choosing more carefully what to
@@ -1225,20 +1237,23 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
     ///
     /// For example, consider the following possible match-pairs:
     ///
-    /// 1. `x @ Some(P)` -- we will do a `Switch` to decide what variant `x` has
+    /// 1. `x @ Some(P)` -- we will do a [`Switch`] to decide what variant `x` has
-    /// 2. `x @ 22` -- we will do a `SwitchInt`
+    /// 2. `x @ 22` -- we will do a [`SwitchInt`] to decide what value `x` has
-    /// 3. `x @ 3..5` -- we will do a range test
+    /// 3. `x @ 3..5` -- we will do a [`Range`] test to decide what range `x` falls in
     /// 4. etc.
     ///
+    /// [`Switch`]: TestKind::Switch
+    /// [`SwitchInt`]: TestKind::SwitchInt
+    /// [`Range`]: TestKind::Range
+    ///
     /// Once we know what sort of test we are going to perform, this
-    /// Tests may also help us with other candidates. So we walk over
+    /// test may also help us winnow down our candidates. So we walk over
     /// the candidates (from high to low priority) and check. This
     /// gives us, for each outcome of the test, a transformed list of
-    /// candidates. For example, if we are testing the current
+    /// candidates. For example, if we are testing `x.0`'s variant,
-    /// variant of `x.0`, and we have a candidate `{x.0 @ Some(v), x.1
+    /// and we have a candidate `(x.0 @ Some(v), x.1 @ 22)`,
-    /// @ 22}`, then we would have a resulting candidate of `{(x.0 as
+    /// then we would have a resulting candidate of `((x.0 as Some).0 @ v, x.1 @ 22)`.
-    /// Some).0 @ v, x.1 @ 22}`. Note that the first match-pair is now
+    /// Note that the first match-pair is now simpler (and, in fact, irrefutable).
-    /// simpler (and, in fact, irrefutable).
     ///
     /// But there may also be candidates that the test just doesn't
     /// apply to. The classical example involves wildcards:
@@ -1268,7 +1283,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
     /// is trivially NP-complete:
     ///
     /// ```rust
-    ///     match (var0, var1, var2, var3, ..) {
+    ///     match (var0, var1, var2, var3, ...) {
     ///         (true, _, _, false, true, ...) => false,
     ///         (_, true, true, false, _, ...) => false,
     ///         (false, _, false, false, _, ...) => false,
@@ -1283,7 +1298,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
     ///
     /// That kind of exponential worst-case might not occur in practice, but
     /// our simplistic treatment of constants and guards would make it occur
-    /// in very common situations - for example #29740:
+    /// in very common situations - for example [#29740]:
     ///
     /// ```rust
     /// match x {
@@ -1294,13 +1309,17 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
     /// }
     /// ```
     ///
-    /// Here we first test the match-pair `x @ "foo"`, which is an `Eq` test.
+    /// [#29740]: https://github.com/rust-lang/rust/issues/29740
+    ///
+    /// Here we first test the match-pair `x @ "foo"`, which is an [`Eq` test].
+    ///
+    /// [`Eq` test]: TestKind::Eq
     ///
     /// It might seem that we would end up with 2 disjoint candidate
-    /// sets, consisting of the first candidate or the other 3, but our
+    /// sets, consisting of the first candidate or the other two, but our
-    /// algorithm doesn't reason about "foo" being distinct from the other
+    /// algorithm doesn't reason about `"foo"` being distinct from the other
     /// constants; it considers the latter arms to potentially match after
-    /// both outcomes, which obviously leads to an exponential amount
+    /// both outcomes, which obviously leads to an exponential number
     /// of tests.
     ///
     /// To avoid these kinds of problems, our algorithm tries to ensure
@@ -1312,16 +1331,16 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
     ///
     /// After we perform our test, we branch into the appropriate candidate
     /// set and recurse with `match_candidates`. These sub-matches are
-    /// obviously inexhaustive - as we discarded our otherwise set - so
+    /// obviously non-exhaustive - as we discarded our otherwise set - so
     /// we set their continuation to do `match_candidates` on the
-    /// "unmatched" set (which is again inexhaustive).
+    /// "unmatched" set (which is again non-exhaustive).
     ///
     /// If you apply this to the above test, you basically wind up
     /// with an if-else-if chain, testing each candidate in turn,
     /// which is precisely what we want.
     ///
     /// In addition to avoiding exponential-time blowups, this algorithm
-    /// also has nice property that each guard and arm is only generated
+    /// also has the nice property that each guard and arm is only generated
     /// once.
     fn test_candidates<'pat, 'b, 'c>(
         &mut self,

compiler/rustc_mir_build/src/build/matches/test.rs

@@ -23,7 +23,7 @@ use std::cmp::Ordering;
 impl<'a, 'tcx> Builder<'a, 'tcx> {
     /// Identifies what test is needed to decide if `match_pair` is applicable.
     ///
-    /// It is a bug to call this with a simplifiable pattern.
+    /// It is a bug to call this with a not-fully-simplified pattern.
     pub(super) fn test<'pat>(&mut self, match_pair: &MatchPair<'pat, 'tcx>) -> Test<'tcx> {
         match *match_pair.pattern.kind {
             PatKind::Variant { ref adt_def, substs: _, variant_index: _, subpatterns: _ } => Test {

compiler/rustc_privacy/Cargo.toml

@@ -13,4 +13,5 @@ rustc_typeck = { path = "../rustc_typeck" }
 rustc_session = { path = "../rustc_session" }
 rustc_span = { path = "../rustc_span" }
 rustc_data_structures = { path = "../rustc_data_structures" }
+rustc_trait_selection = { path = "../rustc_trait_selection" }
 tracing = "0.1"

compiler/rustc_privacy/src/lib.rs

@@ -18,15 +18,17 @@ use rustc_hir::{AssocItemKind, HirIdSet, Node, PatKind};
 use rustc_middle::bug;
 use rustc_middle::hir::map::Map;
 use rustc_middle::middle::privacy::{AccessLevel, AccessLevels};
+use rustc_middle::mir::abstract_const::Node as ACNode;
 use rustc_middle::span_bug;
 use rustc_middle::ty::fold::TypeVisitor;
 use rustc_middle::ty::query::Providers;
-use rustc_middle::ty::subst::InternalSubsts;
+use rustc_middle::ty::subst::{InternalSubsts, Subst};
-use rustc_middle::ty::{self, GenericParamDefKind, TraitRef, Ty, TyCtxt, TypeFoldable};
+use rustc_middle::ty::{self, Const, GenericParamDefKind, TraitRef, Ty, TyCtxt, TypeFoldable};
 use rustc_session::lint;
 use rustc_span::hygiene::Transparency;
 use rustc_span::symbol::{kw, Ident};
 use rustc_span::Span;
+use rustc_trait_selection::traits::const_evaluatable::{self, AbstractConst};
 
 use std::marker::PhantomData;
 use std::ops::ControlFlow;
@@ -112,19 +114,35 @@ where
                 ty.visit_with(self)
             }
             ty::PredicateKind::RegionOutlives(..) => ControlFlow::CONTINUE,
-            ty::PredicateKind::ConstEvaluatable(..)
+            ty::PredicateKind::ConstEvaluatable(defs, substs)
                 if self.def_id_visitor.tcx().features().const_evaluatable_checked =>
             {
-                // FIXME(const_evaluatable_checked): If the constant used here depends on a
+                let tcx = self.def_id_visitor.tcx();
-                // private function we may have to do something here...
+                if let Ok(Some(ct)) = AbstractConst::new(tcx, defs, substs) {
-                //
+                    self.visit_abstract_const_expr(tcx, ct)?;
-                // For now, let's just pretend that everything is fine.
+                }
                 ControlFlow::CONTINUE
             }
             _ => bug!("unexpected predicate: {:?}", predicate),
         }
     }
 
+    fn visit_abstract_const_expr(
+        &mut self,
+        tcx: TyCtxt<'tcx>,
+        ct: AbstractConst<'tcx>,
+    ) -> ControlFlow<V::BreakTy> {
+        const_evaluatable::walk_abstract_const(tcx, ct, |node| match node {
+            ACNode::Leaf(leaf) => {
+                let leaf = leaf.subst(tcx, ct.substs);
+                self.visit_const(leaf)
+            }
+            ACNode::Binop(..) | ACNode::UnaryOp(..) | ACNode::FunctionCall(_, _) => {
+                ControlFlow::CONTINUE
+            }
+        })
+    }
+
     fn visit_predicates(
         &mut self,
         predicates: ty::GenericPredicates<'tcx>,
@@ -241,6 +259,15 @@ where
             ty.super_visit_with(self)
         }
     }
+
+    fn visit_const(&mut self, c: &'tcx Const<'tcx>) -> ControlFlow<Self::BreakTy> {
+        self.visit_ty(c.ty)?;
+        let tcx = self.def_id_visitor.tcx();
+        if let Ok(Some(ct)) = AbstractConst::from_const(tcx, c) {
+            self.visit_abstract_const_expr(tcx, ct)?;
+        }
+        ControlFlow::CONTINUE
+    }
 }
 
 fn min(vis1: ty::Visibility, vis2: ty::Visibility, tcx: TyCtxt<'_>) -> ty::Visibility {

compiler/rustc_trait_selection/src/traits/mod.rs

@@ -6,7 +6,7 @@ pub mod auto_trait;
 mod chalk_fulfill;
 pub mod codegen;
 mod coherence;
-mod const_evaluatable;
+pub mod const_evaluatable;
 mod engine;
 pub mod error_reporting;
 mod fulfill;

library/std/src/io/buffered/bufwriter.rs

@@ -117,7 +117,7 @@ impl<W: Write> BufWriter<W> {
     /// "successfully written" (by returning nonzero success values from
     /// `write`), any 0-length writes from `inner` must be reported as i/o
     /// errors from this method.
-    pub(super) fn flush_buf(&mut self) -> io::Result<()> {
+    pub(in crate::io) fn flush_buf(&mut self) -> io::Result<()> {
         /// Helper struct to ensure the buffer is updated after all the writes
         /// are complete. It tracks the number of written bytes and drains them
         /// all from the front of the buffer when dropped.
@@ -243,6 +243,18 @@ impl<W: Write> BufWriter<W> {
         &self.buf
     }
 
+    /// Returns a mutable reference to the internal buffer.
+    ///
+    /// This can be used to write data directly into the buffer without triggering writers
+    /// to the underlying writer.
+    ///
+    /// That the buffer is a `Vec` is an implementation detail.
+    /// Callers should not modify the capacity as there currently is no public API to do so
+    /// and thus any capacity changes would be unexpected by the user.
+    pub(in crate::io) fn buffer_mut(&mut self) -> &mut Vec<u8> {
+        &mut self.buf
+    }
+
     /// Returns the number of bytes the internal buffer can hold without flushing.
     ///
     /// # Examples

library/std/src/io/copy.rs

@@ -1,4 +1,4 @@
-use crate::io::{self, ErrorKind, Read, Write};
+use super::{BufWriter, ErrorKind, Read, Result, Write, DEFAULT_BUF_SIZE};
 use crate::mem::MaybeUninit;
 
 /// Copies the entire contents of a reader into a writer.
@@ -40,7 +40,7 @@ use crate::mem::MaybeUninit;
 /// }
 /// ```
 #[stable(feature = "rust1", since = "1.0.0")]
-pub fn copy<R: ?Sized, W: ?Sized>(reader: &mut R, writer: &mut W) -> io::Result<u64>
+pub fn copy<R: ?Sized, W: ?Sized>(reader: &mut R, writer: &mut W) -> Result<u64>
 where
     R: Read,
     W: Write,
@@ -54,14 +54,82 @@ where
     }
 }
 
-/// The general read-write-loop implementation of
+/// The userspace read-write-loop implementation of `io::copy` that is used when
-/// `io::copy` that is used when specializations are not available or not applicable.
+/// OS-specific specializations for copy offloading are not available or not applicable.
-pub(crate) fn generic_copy<R: ?Sized, W: ?Sized>(reader: &mut R, writer: &mut W) -> io::Result<u64>
+pub(crate) fn generic_copy<R: ?Sized, W: ?Sized>(reader: &mut R, writer: &mut W) -> Result<u64>
 where
     R: Read,
     W: Write,
 {
-    let mut buf = MaybeUninit::<[u8; super::DEFAULT_BUF_SIZE]>::uninit();
+    BufferedCopySpec::copy_to(reader, writer)
+}
+
+/// Specialization of the read-write loop that either uses a stack buffer
+/// or reuses the internal buffer of a BufWriter
+trait BufferedCopySpec: Write {
+    fn copy_to<R: Read + ?Sized>(reader: &mut R, writer: &mut Self) -> Result<u64>;
+}
+
+impl<W: Write + ?Sized> BufferedCopySpec for W {
+    default fn copy_to<R: Read + ?Sized>(reader: &mut R, writer: &mut Self) -> Result<u64> {
+        stack_buffer_copy(reader, writer)
+    }
+}
+
+impl<I: Write> BufferedCopySpec for BufWriter<I> {
+    fn copy_to<R: Read + ?Sized>(reader: &mut R, writer: &mut Self) -> Result<u64> {
+        if writer.capacity() < DEFAULT_BUF_SIZE {
+            return stack_buffer_copy(reader, writer);
+        }
+
+        // FIXME: #42788
+        //
+        //   - This creates a (mut) reference to a slice of
+        //     _uninitialized_ integers, which is **undefined behavior**
+        //
+        //   - Only the standard library gets to soundly "ignore" this,
+        //     based on its privileged knowledge of unstable rustc
+        //     internals;
+        unsafe {
+            let spare_cap = writer.buffer_mut().spare_capacity_mut();
+            reader.initializer().initialize(MaybeUninit::slice_assume_init_mut(spare_cap));
+        }
+
+        let mut len = 0;
+
+        loop {
+            let buf = writer.buffer_mut();
+            let spare_cap = buf.spare_capacity_mut();
+
+            if spare_cap.len() >= DEFAULT_BUF_SIZE {
+                match reader.read(unsafe { MaybeUninit::slice_assume_init_mut(spare_cap) }) {
+                    Ok(0) => return Ok(len), // EOF reached
+                    Ok(bytes_read) => {
+                        assert!(bytes_read <= spare_cap.len());
+                        // Safety: The initializer contract guarantees that either it or `read`
+                        // will have initialized these bytes. And we just checked that the number
+                        // of bytes is within the buffer capacity.
+                        unsafe { buf.set_len(buf.len() + bytes_read) };
+                        len += bytes_read as u64;
+                        // Read again if the buffer still has enough capacity, as BufWriter itself would do
+                        // This will occur if the reader returns short reads
+                        continue;
+                    }
+                    Err(ref e) if e.kind() == ErrorKind::Interrupted => continue,
+                    Err(e) => return Err(e),
+                }
+            }
+
+            writer.flush_buf()?;
+        }
+    }
+}
+
+fn stack_buffer_copy<R: Read + ?Sized, W: Write + ?Sized>(
+    reader: &mut R,
+    writer: &mut W,
+) -> Result<u64> {
+    let mut buf = MaybeUninit::<[u8; DEFAULT_BUF_SIZE]>::uninit();
     // FIXME: #42788
     //
     //   - This creates a (mut) reference to a slice of

library/std/src/io/util/tests.rs

@@ -1,5 +1,8 @@
+use crate::cmp::{max, min};
 use crate::io::prelude::*;
-use crate::io::{copy, empty, repeat, sink, Empty, Repeat, SeekFrom, Sink};
+use crate::io::{
+    copy, empty, repeat, sink, BufWriter, Empty, Repeat, Result, SeekFrom, Sink, DEFAULT_BUF_SIZE,
+};
 
 #[test]
 fn copy_copies() {
@@ -11,6 +14,51 @@ fn copy_copies() {
     assert_eq!(copy(&mut r as &mut dyn Read, &mut w as &mut dyn Write).unwrap(), 1 << 17);
 }
 
+struct ShortReader {
+    cap: usize,
+    read_size: usize,
+    observed_buffer: usize,
+}
+
+impl Read for ShortReader {
+    fn read(&mut self, buf: &mut [u8]) -> Result<usize> {
+        let bytes = min(self.cap, self.read_size);
+        self.cap -= bytes;
+        self.observed_buffer = max(self.observed_buffer, buf.len());
+        Ok(bytes)
+    }
+}
+
+struct WriteObserver {
+    observed_buffer: usize,
+}
+
+impl Write for WriteObserver {
+    fn write(&mut self, buf: &[u8]) -> Result<usize> {
+        self.observed_buffer = max(self.observed_buffer, buf.len());
+        Ok(buf.len())
+    }
+
+    fn flush(&mut self) -> Result<()> {
+        Ok(())
+    }
+}
+
+#[test]
+fn copy_specializes_bufwriter() {
+    let cap = 117 * 1024;
+    let buf_sz = 16 * 1024;
+    let mut r = ShortReader { cap, observed_buffer: 0, read_size: 1337 };
+    let mut w = BufWriter::with_capacity(buf_sz, WriteObserver { observed_buffer: 0 });
+    assert_eq!(
+        copy(&mut r, &mut w).unwrap(),
+        cap as u64,
+        "expected the whole capacity to be copied"
+    );
+    assert_eq!(r.observed_buffer, buf_sz, "expected a large buffer to be provided to the reader");
+    assert!(w.get_mut().observed_buffer > DEFAULT_BUF_SIZE, "expected coalesced writes");
+}
+
 #[test]
 fn sink_sinks() {
     let mut s = sink();

library/std/src/lib.rs

@@ -284,6 +284,7 @@
 #![feature(maybe_uninit_extra)]
 #![feature(maybe_uninit_ref)]
 #![feature(maybe_uninit_slice)]
+#![feature(maybe_uninit_uninit_array)]
 #![feature(min_specialization)]
 #![feature(needs_panic_runtime)]
 #![feature(negative_impls)]
@@ -327,6 +328,7 @@
 #![feature(unsafe_cell_raw_get)]
 #![feature(unwind_attributes)]
 #![feature(vec_into_raw_parts)]
+#![feature(vec_spare_capacity)]
 #![feature(wake_trait)]
 // NB: the above list is sorted to minimize merge conflicts.
 #![default_lib_allocator]

library/std/src/sys/windows/compat.rs

@@ -74,9 +74,9 @@ macro_rules! compat_fn {
             /// used, and would remove it.
             #[used]
             #[link_section = ".CRT$XCU"]
-            static INIT_TABLE_ENTRY: fn() = init;
+            static INIT_TABLE_ENTRY: unsafe extern "C" fn() = init;
 
-            fn init() {
+            unsafe extern "C" fn init() {
                 // There is no locking here. This code is executed before main() is entered, and
                 // is guaranteed to be single-threaded.
                 //
@@ -84,16 +84,14 @@ macro_rules! compat_fn {
                 // any Rust functions or CRT functions, if those functions touch any global state,
                 // because this function runs during global initialization. For example, DO NOT
                 // do any dynamic allocation, don't call LoadLibrary, etc.
-                unsafe {
+                let module_name: *const u8 = concat!($module, "\0").as_ptr();
-                    let module_name: *const u8 = concat!($module, "\0").as_ptr();
+                let symbol_name: *const u8 = concat!(stringify!($symbol), "\0").as_ptr();
-                    let symbol_name: *const u8 = concat!(stringify!($symbol), "\0").as_ptr();
+                let module_handle = $crate::sys::c::GetModuleHandleA(module_name as *const i8);
-                    let module_handle = $crate::sys::c::GetModuleHandleA(module_name as *const i8);
+                if !module_handle.is_null() {
-                    if !module_handle.is_null() {
+                    match $crate::sys::c::GetProcAddress(module_handle, symbol_name as *const i8) as usize {
-                        match $crate::sys::c::GetProcAddress(module_handle, symbol_name as *const i8) as usize {
+                        0 => {}
-                            0 => {}
+                        n => {
-                            n => {
+                            PTR = Some(mem::transmute::<usize, F>(n));
-                                PTR = Some(mem::transmute::<usize, F>(n));
-                            }
                         }
                     }
                 }

src/bootstrap/compile.rs

@@ -1050,8 +1050,10 @@ impl Step for Assemble {
             builder.copy(&lld_install.join("bin").join(&src_exe), &libdir_bin.join(&dst_exe));
         }
 
-        // Similarly, copy `llvm-dwp` into libdir for Split DWARF.
+        // Similarly, copy `llvm-dwp` into libdir for Split DWARF. Only copy it when the LLVM
-        {
+        // backend is used to avoid unnecessarily building LLVM and because LLVM is not checked
+        // out by default when the LLVM backend is not enabled.
+        if builder.config.rust_codegen_backends.contains(&INTERNER.intern_str("llvm")) {
             let src_exe = exe("llvm-dwp", target_compiler.host);
             let dst_exe = exe("rust-llvm-dwp", target_compiler.host);
             let llvm_config_bin = builder.ensure(native::Llvm { target: target_compiler.host });

src/librustdoc/html/static/main.js

@@ -1695,15 +1695,6 @@ function defocusSearchBar() {
 
             search.innerHTML = output;
             showSearchResults(search);
-            var tds = search.getElementsByTagName("td");
-            var td_width = 0;
-            if (tds.length > 0) {
-                td_width = tds[0].offsetWidth;
-            }
-            var width = search.offsetWidth - 40 - td_width;
-            onEachLazy(search.getElementsByClassName("desc"), function(e) {
-                e.style.width = width + "px";
-            });
             initSearchNav();
             var elems = document.getElementById("titles").childNodes;
             elems[0].onclick = function() { printTab(0); };

src/librustdoc/html/static/rustdoc.css

@@ -1425,7 +1425,7 @@ h4 > .notable-traits {
 		margin-left: 0px;
 	}
 
-	#main {
+	#main, #search {
 		margin-top: 45px;
 		padding: 0;
 	}
@@ -1579,7 +1579,7 @@ h4 > .notable-traits {
 	}
 }
 
-@media (max-width: 416px) {
+@media (max-width: 464px) {
 	#titles, #titles > button {
 		height: 73px;
 	}

src/test/ui/const-generics/const_evaluatable_checked/eval-privacy.rs

@@ -0,0 +1,31 @@
+#![crate_type = "lib"]
+#![feature(const_generics, const_evaluatable_checked)]
+#![allow(incomplete_features)]
+
+pub struct Const<const U: u8>;
+
+pub trait Trait {
+    type AssocTy;
+    fn assoc_fn() -> Self::AssocTy;
+}
+
+impl<const U: u8> Trait for Const<U>
+//~^ WARN private type
+//~| WARN this was previously
+//~| WARN private type
+//~| WARN this was previously
+
+where
+    Const<{ my_const_fn(U) }>: ,
+{
+    type AssocTy = Const<{ my_const_fn(U) }>;
+    //~^ ERROR private type
+    fn assoc_fn() -> Self::AssocTy {
+        Const
+    }
+}
+
+const fn my_const_fn(val: u8) -> u8 {
+    // body of this function doesn't matter
+    val
+}

src/test/ui/const-generics/const_evaluatable_checked/eval-privacy.stderr

@@ -0,0 +1,43 @@
+warning: private type `fn(u8) -> u8 {my_const_fn}` in public interface (error E0446)
+  --> $DIR/eval-privacy.rs:12:1
+   |
+LL | / impl<const U: u8> Trait for Const<U>
+LL | |
+LL | |
+LL | |
+...  |
+LL | |     }
+LL | | }
+   | |_^
+   |
+   = note: `#[warn(private_in_public)]` on by default
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #34537 <https://github.com/rust-lang/rust/issues/34537>
+
+warning: private type `fn(u8) -> u8 {my_const_fn}` in public interface (error E0446)
+  --> $DIR/eval-privacy.rs:12:1
+   |
+LL | / impl<const U: u8> Trait for Const<U>
+LL | |
+LL | |
+LL | |
+...  |
+LL | |     }
+LL | | }
+   | |_^
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #34537 <https://github.com/rust-lang/rust/issues/34537>
+
+error[E0446]: private type `fn(u8) -> u8 {my_const_fn}` in public interface
+  --> $DIR/eval-privacy.rs:21:5
+   |
+LL |     type AssocTy = Const<{ my_const_fn(U) }>;
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ can't leak private type
+...
+LL | const fn my_const_fn(val: u8) -> u8 {
+   | ----------------------------------- `fn(u8) -> u8 {my_const_fn}` declared as private
+
+error: aborting due to previous error; 2 warnings emitted
+
+For more information about this error, try `rustc --explain E0446`.

src/test/ui/lint/special-upper-lower-cases.stderr

@@ -2,7 +2,7 @@ warning: type `𝕟𝕠𝕥𝕒𝕔𝕒𝕞𝕖𝕝` should have an upper camel
   --> $DIR/special-upper-lower-cases.rs:11:8
    |
 LL | struct 𝕟𝕠𝕥𝕒𝕔𝕒𝕞𝕖𝕝;
-   |        ^^^^^^^^^
+   |        ^^^^^^^^^ should have an UpperCamelCase name
    |
    = note: `#[warn(non_camel_case_types)]` on by default
 
@@ -10,13 +10,13 @@ warning: type `𝕟𝕠𝕥_𝕒_𝕔𝕒𝕞𝕖𝕝` should have an upper came
   --> $DIR/special-upper-lower-cases.rs:15:8
    |
 LL | struct 𝕟𝕠𝕥_𝕒_𝕔𝕒𝕞𝕖𝕝;
-   |        ^^^^^^^^^^^ help: convert the identifier to upper camel case: `𝕟𝕠𝕥𝕒𝕔𝕒𝕞𝕖𝕝`
+   |        ^^^^^^^^^^^ should have an UpperCamelCase name
 
 warning: static variable `𝗻𝗼𝗻𝘂𝗽𝗽𝗲𝗿𝗰𝗮𝘀𝗲` should have an upper case name
   --> $DIR/special-upper-lower-cases.rs:18:8
    |
 LL | static 𝗻𝗼𝗻𝘂𝗽𝗽𝗲𝗿𝗰𝗮𝘀𝗲: i32 = 1;
-   |        ^^^^^^^^^^^^
+   |        ^^^^^^^^^^^^ should have an UPPER_CASE name
    |
    = note: `#[warn(non_upper_case_globals)]` on by default
 
@@ -24,7 +24,7 @@ warning: variable `𝓢𝓝𝓐𝓐𝓐𝓐𝓚𝓔𝓢` should have a snake cas
   --> $DIR/special-upper-lower-cases.rs:22:9
    |
 LL |     let 𝓢𝓝𝓐𝓐𝓐𝓐𝓚𝓔𝓢 = 1;
-   |         ^^^^^^^^^
+   |         ^^^^^^^^^ should have a snake_case name
    |
    = note: `#[warn(non_snake_case)]` on by default