Both GCC and Clang write by default a `.comment` section with compiler
information:
```txt
$ gcc -c -xc /dev/null && readelf -p '.comment' null.o
String dump of section '.comment':
[ 1] GCC: (GNU) 11.2.0
$ clang -c -xc /dev/null && readelf -p '.comment' null.o
String dump of section '.comment':
[ 1] clang version 14.0.1 (https://github.com/llvm/llvm-project.git c62053979489ccb002efe411c3af059addcb5d7d)
```
They also implement the `-Qn` flag to avoid doing so:
```txt
$ gcc -Qn -c -xc /dev/null && readelf -p '.comment' null.o
readelf: Warning: Section '.comment' was not dumped because it does not exist!
$ clang -Qn -c -xc /dev/null && readelf -p '.comment' null.o
readelf: Warning: Section '.comment' was not dumped because it does not exist!
```
So far, `rustc` only does it for WebAssembly targets and only
when debug info is enabled:
```txt
$ echo 'fn main(){}' | rustc --target=wasm32-unknown-unknown --emit=llvm-ir -Cdebuginfo=2 - && grep llvm.ident rust_out.ll
!llvm.ident = !{!27}
```
In the RFC part of this PR it was decided to always add
the information, which gets us closer to other popular compilers.
An opt-out flag like GCC and Clang may be added later on if deemed
necessary.
Implementation-wise, this covers both `ModuleLlvm::new()` and
`ModuleLlvm::new_metadata()` cases by moving the addition to
`context::create_module` and adds a few test cases.
ThinLTO also sees the `llvm.ident` named metadata duplicated (in
temporary outputs), so this deduplicates it like it is done for
`wasm.custom_sections`. The tests also check this duplication does
not take place.
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Support `--print KIND=PATH` command line syntax
As is already done for `--emit KIND=PATH` and `-L KIND=PATH`.
In the discussion of #110785, it was pointed out that `--print KIND=PATH` is nicer than trying to apply the single global `-o` path to `--print`'s output, because in general there can be multiple print requests within a single rustc invocation, and anyway `-o` would already be used for a different meaning in the case of `link-args` and `native-static-libs`.
I am interested in using `--print cfg=PATH` in Buck2. Currently Buck2 works around the lack of support for `--print KIND=PATH` by [indirecting through a Python wrapper script](d43cf3a51a/prelude/rust/tools/get_rustc_cfg.py) to redirect rustc's stdout into the location dictated by the build system.
From skimming Cargo's usages of `--print`, it definitely seems like it would benefit from `--print KIND=PATH` too. Currently it is working around the lack of this by inserting `--crate-name=___ --print=crate-name` so that it can look for a line containing `___` as a delimiter between the 2 other `--print` informations it actually cares about. This is commented as a "HACK" and "abuse". 31eda6f7c3/src/cargo/core/compiler/build_context/target_info.rs (L242) (FYI `@weihanglo` as you dealt with this recently in https://github.com/rust-lang/cargo/pull/11633.)
Mentioning reviewers active in #110785: `@fee1-dead` `@jyn514` `@bjorn3`
Verify that all crate sources are in sync
This ensures that rustc will not attempt to link against a cdylib as if it is a rust dylib when an rlib for the same crate is available. Previously rustc didn't actually check if any further formats of a crate which has been loaded are of the same version and if they are actually valid. This caused a cdylib to be interpreted as rust dylib as soon as the corresponding rlib was loaded. As cdylibs don't export any rust symbols, linking would fail if rustc decides to link against the cdylib rather than the rlib.
Two crates depended on the previous behavior by separately compiling a test crate as both rlib and dylib. These have been changed to capture their original spirit to the best of my ability while still working when rustc verifies that all crates are in sync. It is unlikely that build systems depend on the current behavior and in any case we are taking a lot of measures to ensure that any change to either the source or the compilation options (including crate type) results in rustc rejecting it as incompatible. We merely didn't do this check here for now obsolete perf reasons.
Fixes https://github.com/rust-lang/rust/issues/10786
Fixes https://github.com/rust-lang/rust/issues/82151
Fixes https://github.com/rust-lang/rust/issues/82972
Closes https://github.com/bevy-cheatbook/bevy-cheatbook/issues/114
On nightly, dump ICE backtraces to disk
Implement rust-lang/compiler-team#578.
When an ICE is encountered on nightly releases, the new rustc panic handler will also write the contents of the backtrace to disk. If any `delay_span_bug`s are encountered, their backtrace is also added to the file. The platform and rustc version will also be collected.
<img width="1032" alt="Screenshot 2023-03-03 at 2 13 25 PM" src="https://user-images.githubusercontent.com/1606434/222842420-8e039740-4042-4563-b31d-599677171acf.png">
The current behavior will *always* write to disk on nightly builds, regardless of whether the backtrace is printed to the terminal, unless the environment variable `RUSTC_ICE_DISK_DUMP` is set to `0`. This is a compromise and can be changed.
This ensures that rustc will not attempt to link against a cdylib as if
it is a rust dylib when an rlib for the same crate is available.
Previously rustc didn't actually check if any further formats of a
crate which has been loaded are of the same version and if they are
actually valid. This caused a cdylib to be interpreted as rust dylib as
soon as the corresponding rlib was loaded. As cdylibs don't export any
rust symbols, linking would fail if rustc decides to link against the
cdylib rather than the rlib.
Two crates depended on the previous behavior by separately compiling a
test crate as both rlib and dylib. These have been changed to capture
their original spirit to the best of my ability while still working
when rustc verifies that all crates are in sync. It is unlikely that
build systems depend on the current behavior and in any case we are
taking a lot of measures to ensure that any change to either the source
or the compilation options (including crate type) results in rustc
rejecting it as incompatible. We merely didn't do this check here for
now obsolete perf reasons.
Implement rust-lang/compiler-team#578.
When an ICE is encountered on nightly releases, the new rustc panic
handler will also write the contents of the backtrace to disk. If any
`delay_span_bug`s are encountered, their backtrace is also added to the
file. The platform and rustc version will also be collected.
De-duplicate consecutive libs when printing native-static-libs
This PR adds a de-duplicate step just before printing the `native-static-libs`.
This step de-duplicates all the consecutive libs based only on the relevant comparison elements (this exclude spans, ast elements, ...).
Fixes https://github.com/rust-lang/rust/issues/113209
Resurrect: rustc_target: Add alignment to indirectly-passed by-value types, correcting the alignment of byval on x86 in the process.
Same as #111551, which I [accidentally closed](https://github.com/rust-lang/rust/pull/111551#issuecomment-1571222612) :/
---
This resurrects PR #103830, which has sat idle for a while.
Beyond #103830, this also:
- fixes byval alignment for types containing vectors on Darwin (see `tests/codegen/align-byval-vector.rs`)
- fixes byval alignment for overaligned types on x86 Windows (see `tests/codegen/align-byval.rs`)
- fixes ABI for types with 128bit requested alignment on ARM64 Linux (see `tests/codegen/aarch64-struct-align-128.rs`)
r? `@nikic`
---
`@pcwalton's` original PR description is reproduced below:
Commit 88e4d2c from five years ago removed
support for alignment on indirectly-passed arguments because of problems with
the `i686-pc-windows-msvc` target. Unfortunately, the `memcpy` optimizations I
recently added to LLVM 16 depend on this to forward `memcpy`s. This commit
attempts to fix the problems with `byval` parameters on that target and now
correctly adds the `align` attribute.
The problem is summarized in [this comment] by `@eddyb.` Briefly, 32-bit x86 has
special alignment rules for `byval` parameters: for the most part, their
alignment is forced to 4. This is not well-documented anywhere but in the Clang
source. I looked at the logic in Clang `TargetInfo.cpp` and tried to replicate
it here. The relevant methods in that file are
`X86_32ABIInfo::getIndirectResult()` and
`X86_32ABIInfo::getTypeStackAlignInBytes()`. The `align` parameter attribute
for `byval` parameters in LLVM must match the platform ABI, or miscompilations
will occur. Note that this doesn't use the approach suggested by eddyb, because
I felt it was overkill to store the alignment in `on_stack` when special
handling is really only needed for 32-bit x86.
As a side effect, this should fix#80127, because it will make the `align`
parameter attribute for `byval` parameters match the platform ABI on LLVM
x86-64.
[this comment]: #80822 (comment)
...which seems not to be available on some platforms.
Or maybe it is under a different name but I don't want to deal with that
Instead, use two u64s. This isn't exactly the same, but we already have
some coverage of the packed u128 case in another test, so it's not
essential to have it here.
From the test logs, other extern-fn-* tests have this:
[run-make] tests/run-make/extern-fn-with-packed-struct ... ignored, ignored when cross-compiling
[run-make] tests/run-make/extern-fn-with-union ... ignored, ignored when cross-compiling
[run-make] tests/run-make/extern-multiple-copies ... ignored, ignored when cross-compiling
[run-make] tests/run-make/extern-multiple-copies2 ... ignored, ignored when cross-compiling
[run-make] tests/run-make/extern-overrides-distribution ... ignored, ignored when cross-compiling
[run-make] tests/run-make/extra-filename-with-temp-outputs ... ignored, ignored when cross-compiling
[run-make] tests/run-make/extern-fn-explicit-align ... FAILED
alignment of `byval` on x86 in the process.
Commit 88e4d2c291 from five years ago removed
support for alignment on indirectly-passed arguments because of problems with
the `i686-pc-windows-msvc` target. Unfortunately, the `memcpy` optimizations I
recently added to LLVM 16 depend on this to forward `memcpy`s. This commit
attempts to fix the problems with `byval` parameters on that target and now
correctly adds the `align` attribute.
The problem is summarized in [this comment] by @eddyb. Briefly, 32-bit x86 has
special alignment rules for `byval` parameters: for the most part, their
alignment is forced to 4. This is not well-documented anywhere but in the Clang
source. I looked at the logic in Clang `TargetInfo.cpp` and tried to replicate
it here. The relevant methods in that file are
`X86_32ABIInfo::getIndirectResult()` and
`X86_32ABIInfo::getTypeStackAlignInBytes()`. The `align` parameter attribute
for `byval` parameters in LLVM must match the platform ABI, or miscompilations
will occur. Note that this doesn't use the approach suggested by eddyb, because
I felt it was overkill to store the alignment in `on_stack` when special
handling is really only needed for 32-bit x86.
As a side effect, this should fix#80127, because it will make the `align`
parameter attribute for `byval` parameters match the platform ABI on LLVM
x86-64.
[this comment]: https://github.com/rust-lang/rust/pull/80822#issuecomment-829985417
Add Tests for native wasm exceptions
### Motivation
In PR #111322, I added support for native WASM exceptions. I was asked by ``@davidtwco`` to add some tests for it in a follow up PR, which seems like a very good idea.
This PR adds three tests for this feature:
* codegen: ensure the correct LLVM instructions are used
* assembly: ensure the correct WASM instructions are used
* run-make: ensure the exception handling works; the WASM code is run using a small nodejs script which demonstrates the exception handling
### Complications
There are a few changes beside adding the tests, which were necessary
* Tests for the wasm32-unknown-unknown target are (as far as I know) only run on `test-various`. Its docker image uses nodejs-15, which is very old. Experimental support for wasm-exceptions was added in nodejs16. In nodejs 18.12 (LTS), they are stable.
- --> increase nodejs to 18.12 in `test-various`
* codegen/assembly tests are not performed for the wasm32-unknown-unknown target yet
- --> add those to `test-various` as well
Due to the last point, some tests are run which have not run before (assembly+codegen tests for wasm32-unknown-unknown). I added `// ignore wasm32-bare` for those which failed
### Local testing
I run all tests locally using both `test-various` and `wasm32`. As far as I know, none of the other systems run any test for wasm32 targets.
Add `-Zremark-dir` unstable flag to write LLVM optimization remarks to YAML
This PR adds an option for `rustc` to emit LLVM optimization remarks to a set of YAML files, which can then be digested by existing tools, like https://github.com/OfekShilon/optview2. When `-Cremark-dir` is passed, and remarks are enabled (`-Cremark=all`), the remarks will be now written to the specified directory, **instead** of being printed to standard error output. The files are named based on the CGU from which they are being generated.
Currently, the remarks are written using the LLVM streaming machinery, directly in the diagnostics handler. It seemed easier than going back to Rust and then form there back to C++ to use the streamer from the diagnostics handler. But there are many ways to implement this, of course, so I'm open to suggestions :)
I included some comments with questions into the code. Also, I'm not sure how to test this.
r? `@tmiasko`
Convert `run-make/coverage-reports` tests to use a custom compiletest mode
I was frustrated by the fact that most of the coverage tests are glued together with makefiles and shell scripts, so I tried my hand at converting most of them over to a newly-implemented `run-coverage` mode/suite in compiletest.
This ~~*mostly*~~ resolves#85009, ~~though I've left a small number of the existing tests as-is because they would require more work to fix/support~~.
---
I had time to go back and add support for the more troublesome tests that I had initially skipped over, so this PR now manages to completely get rid of `run-make/coverage-reports`.
---
The patches are arranged as follows:
- Declare the new mode/suite in bootstrap
- Small changes to compiletest that will be used by the new mode
- Implement the new mode in compiletest
- Migrate most of the tests over
- Add more code to bootstrap and compiletest to support the remaining tests
- Migrate the remaining tests (with some temporary hacks to avoid re-blessing them)
- Remove the temporary hacks and re-bless the migrated tests
- Remove the unused remnants of `run-make/coverage-reports`
To make it easier to verify that the output snapshots have been migrated
faithfully, this change adds some temporary helper code that lets us avoid
having to completely re-bless the existing snapshots.
A later change in this PR will then re-bless the tests and remove the temporary
helper code.
Make `UnwindAction::Continue` explicit in MIR dump
Makes it easier to spot unwinding related issues in MIR by making `UnwindAction::Continue` explicit, just like all other `UnwindAction`s.
Prevent `.eh_frame` from being emitted for `-C panic=abort`
Since `CheckAlignment` pass is after the `AbortUnwindingCalls` pass, the `UnwindAction::Terminate` inserted in it has no chance to be converted to `UnwindAction::Unreachable` anymore, causing us to emit landing pads that are not necessary. Although these landing pads can themselves be eliminated by LLVM, `.eh_frame` sections are still generated. This causes trouble for Rust-for-Linux project recently.
This PR changes it to generate `UnwindAction::Terminate` when we opt for `-Cpanic=unwind`, and `UnwindAction::Unreachable` for `-Cpanic=abort`.
`@ojeda`
Write to stdout if `-` is given as output file
With this PR, if `-o -` or `--emit KIND=-` is provided, output will be written to stdout instead. Binary output (those of type `obj`, `llvm-bc`, `link` and `metadata`) being written this way will result in an error unless stdout is not a tty. Multiple output types going to stdout will trigger an error too, as they will all be mixded together.
This implements https://github.com/rust-lang/compiler-team/issues/431
The idea behind the changes is to introduce an `OutFileName` enum that represents the output - be it a real path or stdout - and to use this enum along the code paths that handle different output types.
- remove useless commands from test Makefile
- do not unnecessarily remove metadata temporary files because they'll be managed by MaybeTempDir
- remove unused FailedRemove error introduced by this PR
If `-o -` or `--emit KIND=-` is provided, output will be written
to stdout instead. Binary output (`obj`, `llvm-bc`, `link` and
`metadata`) being written this way will result in an error unless
stdout is not a tty. Multiple output types going to stdout will
trigger an error too, as they will all be mixded together.
