Allow disabling ASan instrumentation for globals
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.
(cc https://github.com/rust-lang/rust/issues/39699)
The maximum discriminator value LLVM can currently encode is 2^12. If macro use
results in more than 2^12 calls to the same function attributed to the same
callsite, and those calls are MIR-inlined, we will require more than the maximum
discriminator value to completely represent the debug information. Once we reach
that point drop the debug info instead.
The test relies on the fact that inlining more than 2^12 calls at the same
callsite will trigger a panic (and after the following commit, a warning) due to
LLVM limitations but with collapse_debuginfo the callsites should not be the
same.
the behavior of the type system not only depends on the current
assumptions, but also the currentnphase of the compiler. This is
mostly necessary as we need to decide whether and how to reveal
opaque types. We track this via the `TypingMode`.
CFI: Append debug location to CFI blocks
Currently we're not appending debug locations to the inserted CFI blocks. This shows up in #132615 and #100783. This change fixes that by passing down the debug location to the CFI type-test generation and appending it to the blocks.
Credits also belong to `@jakos-sec` who worked with me on this.
Add a default implementation for CodegenBackend::link
As a side effect this should add raw-dylib support to cg_gcc as the default ArchiveBuilderBuilder that is used implements create_dll_import_lib. I haven't tested if the raw-dylib support actually works however.
coverage: Restrict empty-span expansion to only cover `{` and `}`
Coverage instrumentation has some tricky code for converting a coverage-relevant `Span` into a set of start/end line/byte-column coordinates that will be embedded in the CGU's coverage metadata.
A big part of this complexity is special code for handling empty spans, which are expanded into non-empty spans (if possible) because LLVM's coverage reporter does not handle empty spans well.
This PR simplifies that code by restricting it to only apply in two specific situations: when the character after the empty span is `{`, or the character before the empty span is `}`.
(As an added benefit, this means that the expanded spans no longer extend awkwardly beyond the end of a physical line, which was common under the previous implementation.)
Along the way, this PR also removes some unhelpful code for dealing with function source code spread across multiple files. Functions currently can't have coverage spans in multiple files, and if that ever changes (e.g. to properly support expansion regions) then this code will need to be completely overhauled anyway.
After link_binary the temporary files referenced by CodegenResults are
deleted, so calling link_binary again with the same CodegenResults
should not be allowed.
LLVM does not expect to ever see multiple dbg_declares for the same variable at the same
location with different values. proc-macros make it possible for arbitrary code,
including multiple calls that get inlined, to happen at any given location in the source
code. Add discriminators when that happens so these locations are different to LLVM.
This may interfere with the AddDiscriminators pass in LLVM, which is added by the
unstable flag -Zdebug-info-for-profiling.
Fixes#131944
Rollup of 5 pull requests
Successful merges:
- #132552 (Add v9, v8plus, and leoncasa target feature to sparc and use v8plus in create_object_file)
- #132745 (pointee_info_at: fix logic for recursing into enums)
- #132777 (try_question_mark_nop: update test for LLVM 20)
- #132785 (rustc_target: more target string fixes for LLVM 20)
- #132794 (Use a separate dir for r-a builds consistently in helix config)
r? `@ghost`
`@rustbot` modify labels: rollup
Trim and tidy includes in `rustc_llvm`
These includes tend to accumulate over time, and are usually only removed when something breaks in a new LLVM version, so it's nice to clean them up manually once in a while.
General strategy used for this PR:
- Remove all includes from `LLVMWrapper.h` that aren't needed by the header itself, transplanting them to individual source files as necessary.
- For each source file, temporarily remove each include if doing so doesn't cause a compile error.
- If a “required” include looks like it shouldn't be needed, try replacing it with its sub-includes, then trim that list.
- After doing all of the above, go back and re-add any removed include if the file does actually use things defined in that header, even if the header happens to also be included by something else.
Functions currently can't have mappings in multiple files, and if that ever
changes (e.g. to properly support expansion regions), this code will need to be
completely overhauled anyway.
We already had a dedicated `LocalFileId` index type, but previously we used a
raw `u32` for global file IDs, because index types were harder to pass through
FFI.
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.
Set "symbol name" in raw-dylib import libraries to the decorated name
`windows-rs` received a bug report that mixing raw-dylib generated and the Windows SDK import libraries was causing linker failures: <https://github.com/microsoft/windows-rs/issues/3285>
The root cause turned out to be #124958, that is we are not including the decorated name in the import library and so the import name type is also not being correctly set.
This change modifies the generation of import libraries to set the "symbol name" to the fully decorated name and correctly marks the import as being data vs function.
Note that this also required some changes to how the symbol is named within Rust: for MSVC we now need to use the decorated name but for MinGW we still need to use partially decorated (or undecorated) name.
Fixes#124958
Passing i686 MSVC and MinGW build: <1100043388>
r? `@ChrisDenton`
Add a new `wide-arithmetic` feature for WebAssembly
This commit adds a new rustc target feature named `wide-arithmetic` for WebAssembly targets. This corresponds to the [wide-arithmetic] proposal for WebAssembly which adds new instructions catered towards accelerating integer arithmetic larger than 64-bits. This proposal to WebAssembly is not standard yet so this new feature is flagged as an unstable target feature. Additionally Rust's LLVM version doesn't support this new feature yet since support will first be added in LLVM 20, so the feature filtering logic for LLVM is updated to handle this.
I'll also note that I'm not currently planning to add wasm-specific intrinsics to `std::arch::wasm32` at this time. The currently proposed instructions are all accessible through `i128` or `u128`-based operations which Rust already supports, so intrinsic shouldn't be necessary to get access to these new instructions.
[wide-arithmetic]: https://github.com/WebAssembly/wide-arithmetic
rustc_codegen_llvm: Add a new 'pc' option to branch-protection
Add a new 'pc' option to -Z branch-protection for aarch64 that enables the use of PC as a diversifier in PAC branch protection code.
When the pauth-lr target feature is enabled in combination with -Z branch-protection=pac-ret,pc, the new 9.5-a instructions (pacibsppc, retaasppc, etc) will be generated.
mark some target features as 'forbidden' so they cannot be (un)set with -Ctarget-feature
The context for this is https://github.com/rust-lang/rust/issues/116344: some target features change the way floats are passed between functions. Changing those target features is unsound as code compiled for the same target may now use different ABIs.
So this introduces a new concept of "forbidden" target features (on top of the existing "stable " and "unstable" categories), and makes it a hard error to (un)set such a target feature. For now, the x86 and ARM feature `soft-float` is on that list. We'll have to make some effort to collect more relevant features, and similar features from other targets, but that can happen after the basic infrastructure for this landed. (These features are being collected in https://github.com/rust-lang/rust/issues/131799.)
I've made this a warning for now to give people some time to speak up if this would break something.
MCP: https://github.com/rust-lang/compiler-team/issues/780
