Add `mir-opt` test for more precise drop elaboration
Depends on #69676. This test should ensure that the problem fixed in that PR does not reoccur.
This has been split out from #69676 since the test fails on certain targets where no cleanup blocks are emitted. I have to find the correct `ignore` directives.
r? @oli-obk
Don't store locals in generators that are immediately overwritten with the resume argument
This fixes https://github.com/rust-lang/rust/issues/69672 and makes https://github.com/rust-lang/rust/pull/69033 pass the async fn size tests again (in other words, there will be no size regression of async fn if both this and https://github.com/rust-lang/rust/pull/69033 land).
~~This is a small botch and I'd rather have a more precise analysis, but that seems much harder to pull off, so this special-cases `Yield` terminators that store the resume argument into a simple local (ie. without any field projections) and explicitly marks that local as "not live" in the suspend point of that yield. We know that this local does not need to be stored in the generator for this suspend point because the next resume would immediately overwrite it with the passed-in resume argument anyways. The local might still end up in the state if it is used across another yield.~~ (this now properly updates the dataflow framework to handle this case)
Optimize catch_unwind to match C++ try/catch
This refactors the implementation of catching unwinds to allow LLVM to inline the "try" closure directly into the happy path, avoiding indirection. This means that the catch_unwind implementation is (after this PR) zero-cost unless a panic is thrown.
https://rust.godbolt.org/z/cZcUSB is an example of the current codegen in a simple case. Notably, the codegen is *exactly the same* if `-Cpanic=abort` is passed, which is clearly not great.
This PR, on the other hand, generates the following assembly:
```asm
# -Cpanic=unwind:
push rbx
mov ebx,0x2a
call QWORD PTR [rip+0x1c53c] # <happy>
mov eax,ebx
pop rbx
ret
mov rdi,rax
call QWORD PTR [rip+0x1c537] # cleanup function call
call QWORD PTR [rip+0x1c539] # <unfortunate>
mov ebx,0xd
mov eax,ebx
pop rbx
ret
# -Cpanic=abort:
push rax
call QWORD PTR [rip+0x20a1] # <happy>
mov eax,0x2a
pop rcx
ret
```
Fixes#64224, and resolves#64222.
miri engine: fix treatment of abort intrinsic
I screwed up in https://github.com/rust-lang/rust/pull/69830 and added `abort` to the wrong block of intrinsics, namely the one that actually has a return place. So that branch was never actually reached.
r? @oli-obk
Add support for LLVM globals corresponding to miri allocations should be named alloc123
Adds support for this request from @eddyb in #69134:
> That is, if -Zfewer-names is false (usually only because of --emit=llvm-ir), we should use the same name for LLVM globals we generate out of miri allocs as #67133 does in MIR output (allocN).
>
>This way, we can easily see the mapping between MIR and LLVM IR (and it shouldn't be any costlier for regular compilation, which would continue to use unnamed globals).
r? @eddyb
cc @oli-obk
Changes:
````
Rustup to rust-lang/rust#69674
Use visit_place
Check for mutation
Only fires on temporaries
Extend `redundant_clone` to the case that cloned value is not consumed
add CR feedback
Improve documentation
Use `edition:2018` flag more widely
Update tests/ui/needless_doc_main.rs
Move links to the end of each chapter on adding_lints
Move links to the end of each chapter on CONTRIBUTING
Clean-up adding_lints.md
Clean-up CONTRIBUTING.md
needless_doc_main: only check rust code
Use `node_type_opt` over `node_type`
Fix doc
Fix ICE with trivial_bounds feature
clippy_lints: readme: don't mention crates.io since it is no longer used to publish clippy.
update rust-lang.github.io to rustc-dev-guide.rust-lang.org
Improve placeholder in map_unit_fn
Fix match single binding when in a let stmt
Improve error messages for {option,result}_map_unit_fn
Mention the setup instructions in CONTRIBUTING
redundant_pattern: take binding (ref, ref mut) into account in suggestion.
check_pat: delay creation of the "normal" vec until we reach the branch where is is actually needed
deps: bump itertools 0.8 -> 0.9
add lint on File::read_to_string and File::read_to_end
transition rustc-guide to rustc-dev-guide
Rename macro_use_import -> macro_use_imports
warn on macro_use attr
Fix deploy script for tag deploys
````
Fixes#69957
