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.
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>
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.
There is one comment at a call site and one comment in the function
definition that are mostly saying the same thing. Fold the call site
comment into the function definition comment to reduce duplication.
There are actually some inaccuracies in the comments but let's
deduplicate before we address the inaccuracies.
Move metadata object generation for dylibs to the linker code
This deduplicates some code between codegen backends and may in the future allow adding extra metadata that is only known at link time.
Prerequisite of https://github.com/rust-lang/rust/issues/96708.
Before this change we had two different ways to attempt to locate the
sysroot which are inconsistently used:
* get_or_default_sysroot which tries to locate based on the 0th cli
argument and if that doesn't work falls back to locating it using the
librustc_driver.so location and returns a single path.,
* sysroot_candidates which takes the former and additionally does
another attempt at locating using librustc_driver.so except without
linux multiarch handling and then returns both paths.,
The latter was originally introduced to be able to locate the codegen
backend back when cg_llvm was dynamically linked even for a custom
driver when the --sysroot passed in does not contain a copy of cg_llvm.
Back then get_or_default_sysroot did not attempt to locate the sysroot
based on the location of librustc_driver.so yet. Because that is now
done, the only case where removing sysroot_candidates can break things
is if you have a custom driver inside what looks like a sysroot
including the lib/rustlib directory, but which is missing some parts of
the full sysroot like eg rust-lld.
This case can't actually happen yet (other than via a testing flag), because
currently all of a function's spans must belong to the same file and expansion.
But this will be an important edge case when adding expansion region support.
Refactor Apple version handling in the compiler
Move various Apple version handling code in the compiler out `rustc_codegen_ssa` and into a place where it can be accessed by `rustc_attr_parsing`, which I found to be necessary when doing https://github.com/rust-lang/rust/pull/136867. Thought I'd split it out to make it easier to land, and to make further changes like https://github.com/rust-lang/rust/pull/131477 have fewer conflicts / PR dependencies.
There should be no functional changes in this PR.
`@rustbot` label O-apple
r? rust-lang/compiler
`-Zteach` is perma-unstable, barely used, the highlighting logic buggy and the flag being passed around is tech-debt. We should likely remove `-Zteach` in its entirely.
Make it so that every structured error annotated with `#[derive(Diagnostic)]` that has a field of type `Ty<'_>`, the printing of that value into a `String` will look at the thread-local storage `TyCtxt` in order to shorten to a length appropriate with the terminal width. When this happen, the resulting error will have a note with the file where the full type name was written to.
```
error[E0618]: expected function, found `((..., ..., ..., ...), ..., ..., ...)``
--> long.rs:7:5
|
6 | fn foo(x: D) { //~ `x` has type `(...
| - `x` has type `((..., ..., ..., ...), ..., ..., ...)`
7 | x(); //~ ERROR expected function, found `(...
| ^--
| |
| call expression requires function
|
= note: the full name for the type has been written to 'long.long-type-14182675702747116984.txt'
= note: consider using `--verbose` to print the full type name to the console
```
It's similar to the other limits, e.g. obtained via `get_limit`. So it
makes sense to handle it consistently with the other limits. We now use
`Limit`/`usize` in most places instead of `Option<usize>`, so we use
`Limit::new(usize::MAX)`/`usize::MAX` to emulate how `None` used to work.
The commit also adds `Limit::unlimited`.
DWARF 1 is very different than DWARF 2+ (see the commentary in
https://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html#index-gdwarf)
and LLVM does not really seem to support DWARF 1 as Clang does not offer
a `-gdwarf-1` flag and `llc` will just generate DWARF 2 with the version
set to 1: https://godbolt.org/z/s85d87n3a.
Since this isn't actually supported (and it's not clear it would be
useful anyway), report that DWARF 1 is not supported if it is requested.
Also add a help message to the error saying which versions are supported.
tree-wide: parallel: Fully removed all `Lrc`, replaced with `Arc`
tree-wide: parallel: Fully removed all `Lrc`, replaced with `Arc`
This is continuation of https://github.com/rust-lang/rust/pull/132282 .
I'm pretty sure I did everything right. In particular, I searched all occurrences of `Lrc` in submodules and made sure that they don't need replacement.
There are other possibilities, through.
We can define `enum Lrc<T> { Rc(Rc<T>), Arc(Arc<T>) }`. Or we can make `Lrc` a union and on every clone we can read from special thread-local variable. Or we can add a generic parameter to `Lrc` and, yes, this parameter will be everywhere across all codebase.
So, if you think we should take some alternative approach, then don't merge this PR. But if it is decided to stick with `Arc`, then, please, merge.
cc "Parallel Rustc Front-end" ( https://github.com/rust-lang/rust/issues/113349 )
r? SparrowLii
`@rustbot` label WG-compiler-parallel
