- Set rustc to build only when explicitly asked for
This allows building the stage2 rustc artifacts, which nothing depends
on.
Previously the behavior was as follows (where stageN <-> stage(N-1) artifacts, except for stage0 libstd):
- `x.py build --stage 0`:
- stage0 libstd
- stage1 rustc (but without putting rustc in stage0/)
This leaves you without any rustc at all except for the beta compiler
(https://github.com/rust-lang/rust/issues/73519). This is never what you want.
- `x.py build --stage 1`:
- stage0 libstd
- stage1 rustc
- stage1 libstd
- stage1 rustdoc
- stage2 rustc
This leaves you with a broken stage2 rustc which doesn't even have
libcore and is effectively useless. Additionally, it compiles rustc
twice, which is not normally what you want.
- `x.py build --stage 2`:
- stage0 libstd
- stage1 rustc
- stage1 libstd
- stage2 rustc
- stage2 rustdoc and tools
This builds all tools in release mode. This is the correct usage for CI,
but takes far to long for development.
Now the behavior is as follows:
- `x.py build --stage 0`:
- stage0 libstd
This is suitable for contributors only working on the standard library,
as it means rustc never has to be compiled.
- `x.py build --stage 1`:
- stage0 libstd
- stage1 rustc
- stage1 libstd
- stage1 rustdoc
This is suitable for contributors working on the compiler. It ensures
that you have a working rustc and libstd without having to pass
`src/libstd` in addition.
- `x.py build --stage 2`:
- stage0 libstd
- stage1 rustc
- stage1 libstd
- stage2 rustc
- stage2 libstd
- stage2 rustdoc
This is suitable for debugging errors which only appear with the stage2
compiler.
- `x.py build --stage 2 src/libstd src/rustc`
- stage0 libstd
- stage1 rustc
- stage1 libstd
- stage2 rustc
- stage2 libstd
- stage2 rustdoc, tools, etc.
- stage2 rustc artifacts ('stage3')
This is suitable for CI, which wants all tools in release mode.
However, most of the use cases for this should use `x.py dist` instead,
which builds all the tools without each having to be named individually.
`rustc` allows passing in predefined target triples as well as JSON
target specification files. This change allows bootstrap to have the
first inkling about those differences. This allows building a
cross-compiler for an out-of-tree architecture (even though that
compiler won't work for other reasons).
Even if no one ever uses this functionality, I think the newtype
around the `Interned<String>` improves the readability of the code.
bootstrap: Configurable musl libdir
Make it possible to customize the location of musl libdir using
musl-libdir in config.toml, e.g., to use lib64 instead of lib.
Fortanix SGX target libunwind build process changes
Ticket: https://github.com/fortanix/rust-sgx/issues/174
LLVM related changes (merged): https://github.com/rust-lang/llvm-project/pull/57
Description: libunwind changes needed to run code in sgx environment via rust-sgx.
Target that uses this in rust: x86_64-fortanix-unknown-sgx.
Without this change, rust std for this toolchain is forced to use a precompiled library loaded via environment variable.
With this change we act the same as musl target.
Create self-contained directory and move there some of external binaries/libs
One of the steps to reach design described in https://github.com/rust-lang/rust/issues/68887#issuecomment-633048380
This PR moves things around and allows link code to handle the new directory structure.
[RISC-V] Do not force frame pointers
We have been seeing some very inefficient code that went away when using
`-Cforce-frame-pointers=no`. For instance `core::ptr::drop_in_place` at
`-Oz` was compiled into a function which consisted entirely of saving
registers to the stack, then using the frame pointer to restore the same
registers (without any instructions between the prolog and epilog).
The RISC-V LLVM backend supports frame pointer elimination, so it makes
sense to allow this to happen when using Rust. It's not clear to me that
frame pointers have ever been required in the general case.
In rust-lang/rust#61675 it was pointed out that this made reassembling
stack traces easier, which is true, but there is a code generation
option for forcing frame pointers, and I feel the default should not be
to require frame pointers, given it demonstrably makes code size worse
(around 10% in some embedded applications).
The kinds of targets mentioned in rust-lang/rust#61675 are popular, but
should not dictate that code generation should be worse for all RISC-V
targets, especially as there is a way to use CFI information to
reconstruct the stack when the frame pointer is eliminated. It is also
a misconception that `fp` is always used for the frame pointer. `fp` is
an ABI name for `x8` (aka `s0`), and if no frame pointer is required,
`x8` may be used for other callee-saved values.
---
I am partly posting this to get feedback from @fintelia who introduced the change to require frame pointers, and @hanna-kruppe who had issues with the original PR. I would understand if we wanted to remove this setting on only a subset of RISC-V targets, but my preference would be to remove this setting everywhere.
There are more details on the code size savings seen in Tock here: https://github.com/tock/tock/pull/1660
We have been seeing some very inefficient code that went away when using
`-Cforce-frame-pointers=no`. For instance `core::ptr::drop_in_place` at
`-Oz` was compiled into a function which consisted entirely of saving
registers to the stack, then using the frame pointer to restore the same
registers (without any instructions between the prolog and epilog).
The RISC-V LLVM backend supports frame pointer elimination, so it makes
sense to allow this to happen when using Rust. It's not clear to me that
frame pointers have ever been required in the general case.
In rust-lang/rust#61675 it was pointed out that this made reassembling
stack traces easier, which is true, but there is a code generation
option for forcing frame pointers, and I feel the default should not be
to require frame pointers, given it demonstrably makes code size worse
(around 10% in some embedded applications).
The kinds of targets mentioned in rust-lang/rust#61675 are popular, but
should not dictate that code generation should be worse for all RISC-V
targets, especially as there is a way to use CFI information to
reconstruct the stack when the frame pointer is eliminated. It is also
a misconception that `fp` is always used for the frame pointer. `fp` is
an ABI name for `x8` (aka `s0`), and if no frame pointer is required,
`x8` may be used for other callee-saved values.
This commit does ensure that the standard library is built with unwind
tables, so that users do not need to rebuild the standard library in
order to get a backtrace that includes standard library calls (which is
the original reason for forcing frame pointers).
Move the target libLLVM to llvm-tools-preview
For running the compiler, we usually only need LLVM from `$sysroot/lib`,
which rustup will make available with `LD_LIBRARY_PATH`. We've also been
shipping LLVM in the `$target/lib` directory, which bloats the download
and installed size. The only times we do need the latter are for the
RPATH of `llvm-tools-preview` binaries, and for linking `rustc-dev`
libraries. We'll move it to the `llvm-tools-preview` component directly,
and `rustc-dev` will have an implicit dependency on it.
Here are the dist sizes that I got before and after this change:
llvm-tools-1.45.0-dev-x86_64-unknown-linux-gnu.tar.gz 1.3M 24M
llvm-tools-1.45.0-dev-x86_64-unknown-linux-gnu.tar.xz 748K 17M
rustc-1.45.0-dev-x86_64-unknown-linux-gnu.tar.gz 83M 61M
rustc-1.45.0-dev-x86_64-unknown-linux-gnu.tar.xz 56M 41M
The installed size should reduce by exactly one `libLLVM.so` (~70-80M),
unless you also install `llvm-tools`, and then it should be identical.
Resolves#70838.
For running the compiler, we usually only need LLVM from `$sysroot/lib`,
which rustup will make available with `LD_LIBRARY_PATH`. We've also been
shipping LLVM in the `$target/lib` directory, which bloats the download
and installed size. The only times we do need the latter are for the
RPATH of `llvm-tools-preview` binaries, and for linking `rustc-dev`
libraries. We'll move it to the `llvm-tools-preview` component directly,
and `rustc-dev` will have an implicit dependency on it.
Here are the dist sizes that I got before and after this change:
llvm-tools-1.45.0-dev-x86_64-unknown-linux-gnu.tar.gz 1.3M 24M
llvm-tools-1.45.0-dev-x86_64-unknown-linux-gnu.tar.xz 748K 17M
rustc-1.45.0-dev-x86_64-unknown-linux-gnu.tar.gz 83M 61M
rustc-1.45.0-dev-x86_64-unknown-linux-gnu.tar.xz 56M 41M
The installed size should reduce by exactly one `libLLVM.so` (~70-80M),
unless you also install `llvm-tools`, and then it should be identical.
Rename `bitcode-in-rlib` option to `embed-bitcode`
This commit finishes work first pioneered in #70458 and started in #71528.
The `-C bitcode-in-rlib` option, which has not yet reached stable, is
renamed to `-C embed-bitcode` since that more accurately reflects what
it does now anyway. Various tests and such are updated along the way as
well.
This'll also need to be backported to the beta channel to ensure we
don't accidentally stabilize `-Cbitcode-in-rlib` as well.
This commit finishes work first pioneered in #70458 and started in #71528.
The `-C bitcode-in-rlib` option, which has not yet reached stable, is
renamed to `-C embed-bitcode` since that more accurately reflects what
it does now anyway. Various tests and such are updated along the way as
well.
This'll also need to be backported to the beta channel to ensure we
don't accidentally stabilize `-Cbitcode-in-rlib` as well.
Previously, we relied fully on Cargo to detect that the compiler had changed and
it needed to rebuild the standard library (or later "components"). This used to
not quite be the case prior to moving to LLVM be a separate cargo invocation;
subsequent compiles would recompile std and friends if LLVM had changed
(#67077 is the PR that changes things here).
This PR moves us to clearing out libstd when it is being compiled if the rustc
we're using has changed. We fairly harshly limit the cases in which we do this
(e.g., ignoring dry run mode, and so forth, as well as rustdoc invocations).
This is primarily because when we're not using the compiler directly, so
clearing out in other cases is likely to lead to bugs, particularly as our
deletion scheme is pretty blunt today (basically removing more than is needed,
i.e., not just the rustc artifacts).
In practice, this targeted fix does fix the known bug, though it may not fully
resolve the problem here. It's also not clear that there is a full fix hiding
here that doesn't involve a more major change (like -Zbinary-dep-depinfo was).
As a drive-by fix, don't delete the compiler before calling Build::copy, as that
also deletes the compiler.
When we dynamically link against libLLVM.so (as opposed to statically
linking LLVM), we need libLLVM.so to be present in the stage0 sysroot,
so that stage1 tools (which are built against the stage0
compiler+sysroot) can see it at build time (when the linker is run)
See the comment in the commit for more details
This commit builds on #65501 continue to simplify the build system and
compiler now that we no longer have multiple LLVM backends to ship by
default. Here this switches the compiler back to what it once was long
long ago, which is linking LLVM directly to the compiler rather than
dynamically loading it at runtime. The `codegen-backends` directory of
the sysroot no longer exists and all relevant support in the build
system is removed. Note that `rustc` still supports a dynamically loaded
codegen backend as it did previously, it just no longer supports
dynamically loaded codegen backends in its own sysroot.
Additionally as part of this the `librustc_codegen_llvm` crate now once
again explicitly depends on all of its crates instead of implicitly
loading them through the sysroot. This involved filling out its
`Cargo.toml` and deleting all the now-unnecessary `extern crate`
annotations in the header of the crate. (this in turn required adding a
number of imports for names of macros too).
The end results of this change are:
* Rustbuild's build process for the compiler as all the "oh don't forget
the codegen backend" checks can be easily removed.
* Building `rustc_codegen_llvm` is much simpler since it's simply
another compiler crate.
* Managing the dependencies of `rustc_codegen_llvm` is much simpler since
it's "just another `Cargo.toml` to edit"
* The build process should be a smidge faster because there's more
parallelism in the main rustc build step rather than splitting
`librustc_codegen_llvm` out to its own step.
* The compiler is expected to be slightly faster by default because the
codegen backend does not need to be dynamically loaded.
* Disabling LLVM as part of rustbuild is still supported, supporting
multiple codegen backends is still supported, and dynamic loading of a
codegen backend is still supported.
Split the rustc target libraries into separate rustc-dev component
This is re-applies a squashed version of #64823 as well as including #65337 to fix bugs noted after merging the first PR.
The second PR is confirmed as fixing windows-gnu, and presumably also fixes other platforms, such as musl (i.e. #65335 should be fixed); `RUSTUP_DIST_SERVER=https://dev-static.rust-lang.org rustup toolchain install nightly-2019-10-16` can be installed to confirm that this is indeed the case.
With #65251 landed there's no need to build two LLVM backends and ship
them with rustc, every target we have now uses the same LLVM backend!
This removes the `src/llvm-emscripten` submodule and additionally
removes all support from rustbuild for building the emscripten LLVM
backend. Multiple codegen backend support is left in place for now, and
this is intended to be an easy 10-15 minute win on CI times by avoiding
having to build LLVM twice.
Vadim Petrochenkov
mark
Joshua Nelson
Jake Goulding
Mark Rousskov
Lzu Tao
bors
Manish Goregaokar
Eric Huss
Adrian Cruceru
Ralf Jung
Tomasz Miąsko
Mateusz Mikuła
Sam Elliott
Josh Stone
Alex Crichton
Nicholas Nethercote
Luca Barbieri
Niko Matsakis
Eduard-Mihai Burtescu
Matthias Krüger
Aaron Hill
Brian Wignall
Jethro Beekman