Rust's current mangling scheme depends on compiler internals; loses
information about generic parameters (and other things) which makes for
a worse experience when using external tools that need to interact with
Rust symbol names; is inconsistent; and can contain `.` characters
which aren't universally supported. Therefore, Rust has defined its own
symbol mangling scheme which is defined in terms of the Rust language,
not the compiler implementation; encodes information about generic
parameters in a reversible way; has a consistent definition; and
generates symbols that only use the characters `A-Z`, `a-z`, `0-9`, and
`_`.
Support for the new Rust symbol mangling scheme has been added to
upstream tools that will need to interact with Rust symbols (e.g.
debuggers).
This commit changes the default symbol mangling scheme from the legacy
scheme to the new Rust mangling scheme.
Signed-off-by: David Wood <david.wood@huawei.com>
Error if an autodiff user does not set lto=fat
Based on your feedback, I started to provide a nice error message for a lack of `lto=fat`, instead of us forcing it.
In a next step, we should replace `RUSTFLAGS="-Zautodiff=Enable"` with another Cargo.toml setting, as discussed here: https://github.com/rust-lang/rust/issues/147487#issuecomment-3446558644
As another improvement, we should also figure out why rlib builds do not properly obey the fat=lto setting.
```````@bjorn3```````
Add LLVM realtime sanitizer
This is a new attempt at adding the [LLVM real-time sanitizer](https://clang.llvm.org/docs/RealtimeSanitizer.html) to rust.
Previously this was attempted in https://github.com/rust-lang/rfcs/pull/3766.
Since then the `sanitize` attribute was introduced in https://github.com/rust-lang/rust/pull/142681 and it is a lot more flexible than the old `no_santize` attribute. This allows adding real-time sanitizer without the need for a new attribute, like it was proposed in the RFC. Because i only add a new value to a existing command line flag and to a attribute i don't think an MCP is necessary.
Currently real-time santizer is usable in rust code with the [rtsan-standalone](https://crates.io/crates/rtsan-standalone) crate. This downloads or builds the sanitizer runtime and then links it into the rust binary.
The first commit adds support for more detailed sanitizer information.
The second commit then actually adds real-time sanitizer.
The third adds a warning against using real-time sanitizer with async functions, cloures and blocks because it doesn't behave as expected when used with async functions. I am not sure if this is actually wanted, so i kept it in a seperate commit.
The fourth commit adds the documentation for real-time sanitizer.
This implements a new unstable compiler flag `-Zannotate-moves` that makes
move and copy operations visible in profilers by creating synthetic debug
information. This is achieved with zero runtime cost by manipulating debug
info scopes to make moves/copies appear as calls to `compiler_move<T, SIZE>`
and `compiler_copy<T, SIZE>` marker functions in profiling tools.
This allows developers to identify expensive move/copy operations in their
code using standard profiling tools, without requiring specialized tooling
or runtime instrumentation.
The implementation works at codegen time. When processing MIR operands
(`Operand::Move` and `Operand::Copy`), the codegen creates an `OperandRef`
with an optional `move_annotation` field containing an `Instance` of the
appropriate profiling marker function. When storing the operand,
`store_with_annotation()` wraps the store operation in a synthetic debug
scope that makes it appear inlined from the marker.
Two marker functions (`compiler_move` and `compiler_copy`) are defined
in `library/core/src/profiling.rs`. These are never actually called -
they exist solely as debug info anchors.
Operations are only annotated if the type:
- Meets the size threshold (default: 65 bytes, configurable via
`-Zannotate-moves=SIZE`)
- Has a non-scalar backend representation (scalars use registers,
not memcpy)
This has a very small size impact on object file size. With the default
limit it's well under 0.1%, and even with a very small limit of 8 bytes
it's still ~1.5%. This could be enabled by default.
Add default sanitizers to TargetOptions
Some sanitizers are part of a system's ABI, like the shadow call stack on Aarch64 and RISC-V Fuchsia. Typically ABI options have other spellings, but LLVM has, for historical reasons, marked this as a sanitizer instead of an alternate ABI option. As a result, Fuchsia targets may not be compiled against the correct ABI unless this option is set. This hasn't caused correctness problems, since the backend reserves the SCS register, and thus preserves its value. But this is an issue for unwinding, as the SCS will not be an array of PCs describing the call complete call chain, and will have gaps from callers that don't use the correct ABI.
In the long term, I'd like to see all the sanitizer configs that all frontends copy from clang moved into llvm's libFrontend, and exposed so that frontend consumers can use a small set of simple APIs to use sanitizers in a consistent way across the LLVM ecosystem, but that work is not yet ready today.
Some sanitizers are part of a system's ABI, like the shadow call stack
on Aarch64 and RISC-V Fuchsia. Typically ABI options have other
spellings, but LLVM has, for historical reasons, marked this as a
sanitizer instead of an alternate ABI option. As a result, Fuchsia
targets may not be compiled against the correct ABI unless this option
is set. This hasn't caused correctness problems, since the backend
reserves the SCS register, and thus preserves its value. But this is an
issue for unwinding, as the SCS will not be an array of PCs describing
the call complete call chain, and will have gaps from callers that don't
use the correct ABI.
In the long term, I'd like to see all the sanitizer configs that all
frontends copy from clang moved into llvm's libFrontend, and exposed so
that frontend consumers can use a small set of simple APIs to use
sanitizers in a consistent way across the LLVM ecosystem, but that work
is not yet ready today.
Rollup of 10 pull requests
Successful merges:
- rust-lang/rust#135602 (Tweak output of missing lifetime on associated type)
- rust-lang/rust#139751 (Implement pin-project in pattern matching for `&pin mut|const T`)
- rust-lang/rust#142682 (Update bundled musl to 1.2.5)
- rust-lang/rust#148171 (Simplify code to generate line numbers in highlight)
- rust-lang/rust#148263 (Unpin `libc` and `rustix` in `compiler` and `rustbook`)
- rust-lang/rust#148301 ([rustdoc search] Include extern crates when filtering on `import`)
- rust-lang/rust#148330 (Don't require dlltool with the dummy backend on MinGW)
- rust-lang/rust#148338 (cleanup: upstream dropped amx-transpose functionality)
- rust-lang/rust#148340 (Clippy subtree update)
- rust-lang/rust#148343 (`nonpoison::Condvar` should take `MutexGuard` by reference)
r? `@ghost`
`@rustbot` modify labels: rollup
cg_llvm: Pass `debuginfo_compression` through FFI as an enum
There are only three possible values, making an enum more appropriate.
This avoids string allocation on the Rust side, and avoids ad-hoc `!strcmp` to convert back to an enum on the C++ side.
Allow codegen backends to indicate which crate types they support
This way cargo will drop the unsupported crate types for crates that
specify multiple crate types.
This is a prerequisite for https://github.com/rust-lang/miri/pull/4648.
chore: Update to the latest annotate-snippets
This PR updates `annotate-snippets` to the latest version and updates the adapter code[^1] so that `AnnotateSnippetEmitter`'s output matches `HumanEmitter`'s output. If anyone would like to see the differences[^2] between `AnnotateSnippetEmitter` and `HumanEmitter`, [I have a branch](https://github.com/Muscraft/rust/tree/annotate-snippets-default-renderer) where `AnnotateSnippetEmitter` is used in place of `HumanEmitter`.
[^1]: A lot of the adapter code changes are based on code for `HumanEmitter`.
[^2]: Some of the test differences will go away when rust-lang/rust#148001 and rust-lang/rust#148004 are merged.
The issue cannot be reproduced with the former testcase of creating external crates because
rust refuses to use "external crate 28_找出字符串中第一个匹配项的下标"
because it is not a valid indentifier (starts with number, and contain non ascii chars)
But still using 28_找出字符串中第一个匹配项的下标.rs as a filename is accepted by previous rustc releases
So we consider it valid, and add an integration test for it to catch any regression on other code related to non ascii filenames.
feat(rustdoc): `--emit=depinfo` output to stdout via `-`
rustdoc's `--emit=depinfo` flag now supports using `-` to write the output to stdout,
aligning with rustc's behavior.
This will fix <https://github.com/rust-lang/rust/issues/147649>.
### How to review
* The first commit demonstrates that `rustdoc --emit=depinfo=-` hasn't yet supported emitting to stdout.
* The second implements it and the diff shows how the behavior changes.
When -Z autodiff=Enable is used, the compiler automatically enables
fat-lto for all crates. However, proc-macro crates cannot use fat-lto
without the -Zdylib-lto flag, causing compilation errors.
This commit modifies the lto() method in Session to exclude proc-macro
crates from fat-lto when autodiff is enabled, while preserving the
existing behavior for all other crate types.
The fix ensures that:
- Non-proc-macro crates still get fat-lto when autodiff is enabled
- Proc-macro crates are excluded from fat-lto when autodiff is enabled
- Existing autodiff functionality remains unchanged for regular crates
Signed-off-by: Osama Abdelkader <osama.abdelkader@gmail.com>
Fix backtraces with `-C panic=abort` on linux; emit unwind tables by default
The linux backtrace unwinder relies on unwind tables to work properly, and generating and printing a backtrace is done by for example the default panic hook.
Begin emitting unwind tables by default again with `-C panic=abort` (see history below) so that backtraces work.
Closes https://github.com/rust-lang/rust/issues/81902 which is **regression-from-stable-to-stable**
Closes https://github.com/rust-lang/rust/issues/94815
### History
Backtraces with `-C panic=abort` used to work in Rust 1.22 but broke in Rust 1.23, because in 1.23 we stopped emitting unwind tables with `-C panic=abort` (see https://github.com/rust-lang/rust/pull/45031 and https://github.com/rust-lang/rust/issues/81902#issuecomment-3046487084).
In 1.45 a workaround in the form of `-C force-unwind-tables=yes` was added (see https://github.com/rust-lang/rust/pull/69984).
`-C panic=abort` was added in [Rust 1.10](https://blog.rust-lang.org/2016/07/07/Rust-1.10/#what-s-in-1-10-stable) and the motivation was binary size and compile time. But given how confusing that behavior has turned out to be, it is better to make binary size optimization opt-in with `-C force-unwind-tables=no` rather than default since the current default breaks backtraces.
Besides, if binary size is a primary concern, there are many other tricks that can be used that has a higher impact.
# Release Note Entry Draft:
## Compatibility Notes
* [Fix backtraces with `-C panic=abort` on Linux by generating unwind tables by default](https://github.com/rust-lang/rust/pull/143613). Build with `-C force-unwind-tables=no` to keep omitting unwind tables.
try-job: aarch64-apple
try-job: armhf-gnu
try-job: aarch64-msvc-1
The linux backtrace unwinder relies on unwind tables to work properly,
and generating and printing a backtrace is done by for example the
default panic hook.
Begin emitting unwind tables by default again with `-C panic=abort` (see
history below) so that backtraces work.
History
=======
Backtraces with `-C panic=abort` used to work in Rust 1.22 but broke in
Rust 1.23, because in 1.23 we stopped emitting unwind tables with `-C
panic=abort` (see 24cc38e3b00).
In 1.45 (see cda994633ee) a workaround in the form
of `-C force-unwind-tables=yes` was added.
`-C panic=abort` was added in [Rust
1.10](https://blog.rust-lang.org/2016/07/07/Rust-1.10/#what-s-in-1-10-stable)
and the motivation was binary size and compile time. But given how
confusing that behavior has turned out to be, it is better to make
binary size optimization opt-in with `-C force-unwind-tables=no` rather
than default since the current default breaks backtraces.
Besides, if binary size is a primary concern, there are many other
tricks that can be used that has a higher impact.
debuginfo: add an unstable flag to write split DWARF to an explicit directory
Bazel requires knowledge of outputs from actions at analysis time, including file or directory name. In order to work around the lack of predictable output name for dwo files, we group the dwo files in a subdirectory of --out-dir as a post-processing step before returning control to bazel. Unfortunately some debugging workflows rely on directly opening the dwo file rather than loading the merged dwp file, and our trick of moving the files breaks those users. We can't just hardlink the file or copy it, because with remote build execution we wouldn't end up with the un-moved file copied back to the developer's workstation. As a fix, we add this unstable flag that causes dwo files to be written to a build-system-controllable location, which then lets bazel hoover up the dwo files, but the objects also have the correct path for the dwo files.
r? `@davidtwco`
compiler: remove AbiAlign inside TargetDataLayout
AbiAlign is a thin wrapper around Align, extant mostly because we used to track a separate quasi-notion of alignment that was never a real notion of alignment and removing all of it at once was too churny. This PR maintains AbiAlign usage in public API and most of the compiler, but direct access of these fields for TargetDataLayout is now in terms of Align only.
