Simplify FFI calls for `-Ztime-llvm-passes` and `-Zprint-codegen-stats`
The existing code for these unstable LLVM-infodump flags was jumping through hoops to pass an allocated C string across the FFI boundary, when it's much simpler to just write to a `&RustString` instead.
coverage: Extract safe FFI wrapper functions to `llvm_cov`
This PR takes all of the inline `unsafe` calls in coverage codegen, and all the safe wrapper functions in `coverageinfo/mod.rs`, and moves them to a new `llvm_cov` submodule that is dedicated to safe FFI wrapper functions. This reduces the mixing of abstraction levels in the rest of coverage codegen.
As a follow-up, this PR also tidies up the names and signatures of several of the coverage FFI functions.
Rollup of 15 pull requests
Successful merges:
- #129329 (Implement `From<&mut {slice}>` for `Box/Rc/Arc<{slice}>`)
- #131377 (Add LowerExp and UpperExp implementations to NonZero)
- #132393 (Docs: added brief colon explanation)
- #132437 (coverage: Regression test for inlining into an uninstrumented crate)
- #132499 (unicode_data.rs: show command for generating file)
- #132503 (better test for const HashMap; remove const_hash leftovers)
- #132511 (stabilize const_arguments_as_str)
- #132520 (NFC add known bug nr to test)
- #132522 (make codegen help output more consistent)
- #132523 (Added regression test for generics index out of bounds)
- #132528 (Use `*_opt` typeck results fns to not ICE in fallback suggestion)
- #132537 (PassWrapper: adapt for llvm/llvm-project@5445edb5d)
- #132540 (Do not format generic consts)
- #132543 (add and update some crashtests)
- #132550 (compiler: Continue introducing rustc_abi to the compiler)
r? `@ghost`
`@rustbot` modify labels: rollup
Port most of `--print=target-cpus` to Rust
The logic and formatting needed by `--print=target-cpus` has historically been carried out in C++ code. Originally it used `printf` to write directly to the console, but later it switched over to writing to a `std::ostringstream` and then passing its buffer to a callback function pointer.
This PR replaces that C++ code with a very simple function that writes a list of CPU names to a `&RustString`, with the rest of the logic and formatting being handled by ordinary safe Rust code.
PassWrapper: adapt for llvm/llvm-project@5445edb5d
As with ab5583ed1e, we had been explicitly passing defaults whose type have changed. Rather than do an ifdef, we simply rely on the defaults.
````@rustbot```` label: +llvm-main
PassWrapper: adapt for llvm/llvm-project@b01e2a8b56
A boolean turned into an enum. None matches the old behavior of false, so we pass that.
`@rustbot` label: +llvm-main
AddressSanitizer adds instrumentation to global variables unless the
[`no_sanitize_address`](https://llvm.org/docs/LangRef.html#global-attributes)
attribute is set on them.
This commit extends the existing `#[no_sanitize(address)]` attribute to
set this; previously it only had the desired effect on functions.
As with ab5583ed1e, we had been explicitly
passing defaults whose type have changed. Rather than do an ifdef, we
simply rely on the defaults.
@rustbot label: +llvm-main
We don't see a reason to explicitly pass the default here, so just use
the default instead of explicitly passing it and needing an ifdef.
@rustbot label: +llvm-main
cg_llvm: Clean up FFI calls for operand bundles
All of these FFI functions have equivalents in the stable LLVM-C API, though `LLVMBuildCallBr` requires a temporary polyfill on LLVM 18.
This PR also creates a clear split between `OperandBundleOwned` and `OperandBundle`, and updates the internals of the owner to be a little less terrifying.
cg_llvm: Clean up FFI calls for setting module flags
This is a combination of several inter-related changes to how module flags are set:
- Remove some unnecessary code for setting an `"LTOPostLink"` flag, which has been obsolete since LLVM 17.
- Define our own enum instead of relying on enum values defined by LLVM's unstable C++ API.
- Use safe wrapper functions to set module flags, instead of direct `unsafe` calls.
- Consistently pass pointer/length strings instead of C strings.
- Remove or shrink some `unsafe` blocks.
- Don't rely on enum values defined by LLVM's C++ API
- Use safe wrapper functions instead of direct `unsafe` calls
- Consistently pass pointer/length strings instead of C strings
coverage: Pass coverage mappings to LLVM as separate structs
Instead of trying to cram *N* different kinds of coverage mapping data into a single list for FFI, pass *N* different lists of simpler structs.
This avoids the need to fill unused fields with dummy values, and avoids the need to tag structs with their underlying kind. It also lets us call the dedicated LLVM constructors for each different mapping type, instead of having to go through the complex general-purpose constructor.
Even though this adds multiple new structs to the FFI surface area, the resulting C++ code is simpler and shorter.
---
I've structured this mostly as a single atomic patch, rather than a series of incremental changes, because that avoids the need to make fiddly fixes to code that is about to be deleted anyway.
RustWrapper: adapt for rename of Intrinsic::getDeclaration
llvm/llvm-project@fa789dffb1 renamed getDeclaration to getOrInsertDeclaration.
`@rustbot` label: +llvm-main
rustc_llvm: adapt to flattened CLI args in LLVM
This changed in
llvm/llvm-project@e190d074a0. I decided to stick with more duplication between the ifdef blocks to make the code easier to read for the next two years before we can plausibly drop LLVM 19.
`@rustbot` label: +llvm-main
try-job: x86_64-msvc
This changed in
llvm/llvm-project@e190d074a0. I decided to
stick with more duplication between the ifdef blocks to make the code
easier to read for the next two years before we can plausibly drop LLVM
19.
@rustbot label: +llvm-main
llvm-wrapper: adapt for LLVM API changes
No functional changes intended.
Updates the wrapper for 21eddfac3d.
````@rustbot```` label: +llvm-main
r? ````@nikic````
Disable the tests and generate an error if MC/DC is used on LLVM 19.
The support will be ported separately, as it is substantially
different on LLVM 19, and there are no plans to support both
versions.
Sync ar_archive_writer to LLVM 18.1.3
From LLVM 15.0.0-rc3. This adds support for COFF archives containing Arm64EC object files and has various fixes for AIX big archive files.
The return value changed from an Instruction to a DbgRecord in
LLVM 19. As we don't actually use the result, drop the return
value entirely to support both.
Since this codegen flag now only controls LLVM-generated comments rather than
all assembly comments, make the name more accurate (and also match Clang).
If we don't do this, some versions of LLVM (at least 17, experimentally)
will double-emit some error messages, which is how I noticed this. Given
that it seems to be costing some extra work, let's only request the
summary bitcode production if we'll actually bother writing it down,
otherwise skip it.
Typical uses of ThinLTO don't have any use for this as a standalone
file, but distributed ThinLTO uses this to make the linker phase more
efficient. With clang you'd do something like `clang -flto=thin
-fthin-link-bitcode=foo.indexing.o -c foo.c` and then get both foo.o
(full of bitcode) and foo.indexing.o (just the summary or index part of
the bitcode). That's then usable by a two-stage linking process that's
more friendly to distributed build systems like bazel, which is why I'm
working on this area.
I talked some to @teresajohnson about naming in this area, as things
seem to be a little confused between various blog posts and build
systems. "bitcode index" and "bitcode summary" tend to be a little too
ambiguous, and she tends to use "thin link bitcode" and "minimized
bitcode" (which matches the descriptions in LLVM). Since the clang
option is thin-link-bitcode, I went with that to try and not add a new
spelling in the world.
Per @dtolnay, you can work around the lack of this by using `lld
--thinlto-index-only` to do the indexing on regular .o files of
bitcode, but that is a bit wasteful on actions when we already have all
the information in rustc and could just write out the matching minimized
bitcode. I didn't test that at all in our infrastructure, because by the
time I learned that I already had this patch largely written.
Set writable and dead_on_unwind attributes for sret arguments
Set the `writable` and `dead_on_unwind` attributes for `sret` arguments. This allows call slot optimization to remove more memcpy's.
See https://llvm.org/docs/LangRef.html#parameter-attributes for the specification of these attributes. In short, the statement we're making here is that:
* The return slot is writable.
* The return slot will not be read if the function unwinds.
Fixes https://github.com/rust-lang/rust/issues/90595.
Rust passes a *const &OperandBundleDef to these APIs, usually from a
Vec<&OperandBundleDef> or so. Previously we were dereferencing that
pointer and passing it to the ArrayRef constructor with some length (N).
This meant that if the length was 0, we were dereferencing a pointer to
nowhere, and if the length was >1 then loading the *second* element
somewhere in LLVM would've been reading past the end.
Since Rust can't hold OperandBundleDef by-value we're forced to indirect
through a vector that copies out the OperandBundleDefs from the
by-reference list on the Rust side in order to match the LLVM expected
API.
Remove unnecessary cast from `LLVMRustGetInstrProfIncrementIntrinsic`
(Noticed while reviewing #123409.)
This particular cast appears to have been copied over from clang, but there are plenty of other call sites in clang that don't bother with a cast here, and it works fine without one.
For context, `llvm::Intrinsic::ID` is a typedef for `unsigned`, and `llvm::Intrinsic::instrprof_increment` is a member of `enum IndependentIntrinsics : unsigned`.
---
The formatting change in `unwrap(M)` is the result of manually running `clang-format` on this file, and then reverting all changes other than the ones affecting these lines.
Add consistency with phrases "meantime" and "mean time"
"mean time" is used in a few places while "meantime" is used everywhere else; this would make usage consistent throughout the codebase.
This particular cast appears to have been copied over from clang, but there are
plenty of other call sites in clang that don't bother with a cast here, and it
works fine without one.
For context, `llvm::Intrinsic::ID` is a typedef for `unsigned`, and
`llvm::Intrinsic::instrprof_increment` is a member of
`enum IndependentIntrinsics : unsigned`.
Manually run `clang-format` on `CoverageMappingWrapper.cpp`
In the current version of #123409, there are several unrelated changes to `CoverageMappingWrapper.cpp` that seem to be the result of running `clang-format` on that file.
Instead of asking for those changes to be undone, I figure it's easier to just make them myself as a separate PR, since I was vaguely intending to do that at some point anyway.
In a few cases I've strategically added comments to make the grouping of parameters a little nicer, but mostly it doesn't matter much.
The bad-alloc installer was incorrectly asserting that the other handler
isn't set yet, instead of checking its own, but we can avoid that by
changing the order we install them.
Ref: https://github.com/llvm/llvm-project/issues/83040
LLVM's default bad-alloc handler may throw if exceptions are enabled,
and `operator new` isn't hooked at all by default. Now we register our
own handler that prints a message similar to fatal errors, then aborts.
We also call the function that registers the C++ `std::new_handler`.
