Warn when gold was used as the linker
gold has been deprecated recently and is known to behave incorrectly around Rust programs, including miscompiling `#[used(linker)]`. Tell people to switch to a different linker instead.
closesrust-lang/rust#141748
r? bjorn3
gold has been deprecated recently and is known to behave incorrectly
around Rust programs, including miscompiling `#[used(linker)]`.
Tell people to switch to a different linker instead.
Co-Authored-By: bjorn3 <17426603+bjorn3@users.noreply.github.com>
Remove RUSTC_RETRY_LINKER_ON_SEGFAULT hack
It looks like this was added in rust-lang/rust#40422 6 years ago because of issues with the MacOS linker. MacOS got a new linker in the meantime, so that should probably be resolved now. Hopefully.
r? petrochenkov
It looks like this was added 6 years ago because of issues with the
MacOS linker. MacOS got a new linker in the meantime, so that should
probably be resolved now. Hopefully.
A variety of improvements to the codegen backends
Some are just general improvements to cg_ssa or cg_llvm, while others will make it slightly easier to use cg_ssa in cg_clif in the future.
Emit warning while outputs is not exe and prints linkage info
cc #137384
```bash
$ rustc +stage1 /dev/null --print native-static-libs --crate-type staticlib --emit metadata
warning: skipping link step due to conflict: cannot output linkage information without emitting executable
note: consider emitting executable to print link information
warning: 1 warning emitted
```
There is no safety contract and I don't think any of them can actually
cause UB in more ways than passing malicious source code to rustc can.
While LtoModuleCodegen::optimize says that the returned ModuleCodegen
points into the LTO module, the LTO module has already been dropped by
the time this function returns, so if the returned ModuleCodegen indeed
points into the LTO module, we would have seen crashes on every LTO
compilation, which we don't. As such the comment is outdated.
- Rename `USED` to `USED_COMPILER` to better reflect its behavior.
- Reorder some items to group the used and allocator flags together
- Renumber them without gaps
make `rustc_attr_parsing` less dominant in the rustc crate graph
It has/had a glob re-export of `rustc_attr_data_structures`, which is a crate much lower in the graph, and a lot of crates were using it *just* (or *mostly*) for that re-export, while they can rely on `rustc_attr_data_structures` directly.
Previous graph:
Graph with this PR:
The first commit keeps the re-export, and just changes the dependency if possible. The second commit is the "breaking change" which removes the re-export, and "explicitly" adds the `rustc_attr_data_structures` dependency where needed. It also switches over some src/tools/*.
The second commit is actually a lot more involved than I expected. Please let me know if it's a better idea to back it out and just keep the first commit.
turn lld warning on old gccs into info log
As discussed in #140964 and IRL, this PR switches the spammy warning shown unconditionally when an old gcc doesn't support `-fuse-ld=lld` and we retry linking without it, to an info debug log so we don't lose it.
r? `@Mark-Simulacrum`
Fixes#140964
Unfortunately, multiple people are reporting linker warnings related to
`__rust_no_alloc_shim_is_unstable` after this change. The solution isn't
quite clear yet, let's revert to green for now, and try a reland with a
determined solution for `__rust_no_alloc_shim_is_unstable`.
This reverts commit c8b7f32434, reversing
changes made to 667247db71.
shared-generics: Do not share instantiations that contain local-only types
In Zed shared-generics loading takes up a significant chunk of time in incremental build, as rustc deserializes rmeta of all dependencies of a crate. I've recently realized that shared-generics includes all instantiations of some_generic_function in the following snippet:
```rs
pub fn some_generic_function(_: impl Fn()) {}
pub fn non_generic_function() {
some_generic_function(|| {});
some_generic_function(|| {});
some_generic_function(|| {});
some_generic_function(|| {});
some_generic_function(|| {});
some_generic_function(|| {});
some_generic_function(|| {});
}
```
even though none of these instantiations can actually be created from outside of `non_generic_function`. This is a dummy example, but we do rely on invoking callbacks with FnOnce a lot in our codebase.
This PR makes shared-generics account for visibilities of generic arguments; an item is only considered for exporting if it is reachable from the outside or if all of it's arguments are visible outside of the local crate.
This PR reduces incremental build time for Zed (touch editor.rs scenario) from 12.4s to 10.4s. I'd love to see a perf run if possible; per my checks this PR does not incur new instantiations in downstream crates, so if there'd be perf regressions, I'd expect them to come from newly-introduced visibility checks.
In Zed shared-generics loading takes up a significant chunk of time in incremental build, as rustc deserializes rmeta of all dependencies of a crate.
I've recently realized that shared-generics includes all instantiations of some_generic_function in the following snippet:
```rs
pub fn some_generic_function(_: impl Fn()) {}
pub fn non_generic_function() {
some_generic_function(|| {});
some_generic_function(|| {});
some_generic_function(|| {});
some_generic_function(|| {});
some_generic_function(|| {});
some_generic_function(|| {});
some_generic_function(|| {});
}
```
even though none of these instantiations can actually be created from outside of `non_generic_function`.
This PR makes shared-generics account for visibilities of generic arguments; an item is only considered for exporting if it is reachable from the outside or if all of it's arguments are visible outside of the local crate.
This PR reduces incremental build time for Zed (touch edito.rs scenario) from 12.4s to 10.4s.
Co-authored-by: bjorn3 <17426603+bjorn3@users.noreply.github.com>
If creating a temporary directory fails with permission denied then retry with backoff
On Windows, if creating a temporary directory fails with permission denied then use a retry/backoff loop. This hopefully fixes a recuring error in our CI.
cc ```@jieyouxu,``` https://github.com/rust-lang/rust/issues/133959
On Windows, if creating a temporary directory fails with permission denied then use a retry/backoff loop. This hopefully fixes a recuring error in our CI.
Rename `is_like_osx` to `is_like_darwin`
Replace `is_like_osx` with `is_like_darwin`, which more closely describes reality (OS X is the pre-2016 name for macOS, and is by now quite outdated; Darwin is the overall name for the OS underlying Apple's macOS, iOS, etc.).
``@rustbot`` label O-apple
r? compiler
Improve `xcrun` error handling
The compiler invokes `xcrun` on macOS when linking Apple targets, to find the Xcode SDK which contain all the necessary linker stubs. The error messages that `xcrun` outputs aren't always that great though, so this PR tries to improve that by providing extra context when an error occurs.
Fixes https://github.com/rust-lang/rust/issues/56829.
Fixes https://github.com/rust-lang/rust/issues/84534.
Part of https://github.com/rust-lang/rust/issues/129432.
See also the alternative https://github.com/rust-lang/rust/pull/131433.
Tested on:
- `x86_64-apple-darwin`, MacBook Pro running Mac OS X 10.12.6
- With no tooling installed
- With Xcode 9.2
- With Xcode 9.2 Commandline Tools
- `aarch64-apple-darwin`, MacBook M2 Pro running macOS 14.7.4
- With Xcode 13.4.1
- With Xcode 16.2
- Inside `nix-shell -p xcbuild` (nixpkgs' `xcrun` shim)
- `aarch64-apple-darwin`, VM running macOS 15.3.1
- With no tooling installed
- With Xcode 16.2 Commandline Tools
``@rustbot`` label O-apple
r? compiler
CC ``@BlackHoleFox`` ``@thomcc``
Remove InstanceKind::generates_cgu_internal_copy
This PR should not contain any behavior changes. Before this PR, the logic for selecting instantiation mode is spread across all of
* `instantiation_mode`
* `cross_crate_inlinable`
* `generates_cgu_internal_copy`
* `requires_inline`
The last two of those functions are not well-designed. The function that actually decides if we generate a CGU-internal copy is `instantiation_mode`, _not_ `generates_cgu_internal_copy`. The function `requires_inline` documents that it is about the LLVM `inline` attribute and that it is a hint. The LLVM attribute is called `inlinehint`, this function is also used by other codegen backends, and since it is part of instantiation mode selection it is *not* a hint.
The goal of this PR is to start cleaning up the logic into a sequence of checks that have a more logical flow and are easier to customize in the future (to do things like improve incrementality or improve optimizations without causing obscure linker errors because you forgot to update another part of the compiler).
