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compilation, which we don't. As such the comment is outdated.
Improve intrinsic handling in cg_ssa
* Move all intrinsic handling code to the start of `codegen_call_terminator`.
* Push some intrinsic handling code into `codegen_intrinsic_call`.
* Don't depend on FnAbi for intrinsics.
Intrinsics are not real functions and as such don't have any calling
convention. Trying to compute a calling convention for an intrinsic
anyway is a nonsensical operation.
- 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
Use the fn_span when emitting function calls for better debug info.
This especially improves the developer experience for long chains of function calls that span multiple lines, which is common with builder patterns, chains of iterator/future combinators, etc.
try-job: armhf-gnu
try-job: test-various
try-job: x86_64-msvc-1
try-job: arm-android
r? `@jieyouxu`
This especially improves the developer experience for long chains
of function calls that span multiple lines, which is common with
builder patterns, chains of iterator/future combinators, etc.
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 c8b7f32434c0306db5c1b974ee43443746098a92, reversing
changes made to 667247db71ea18c4130dd018d060e7f09d589490.
Stage0 bootstrap update
This PR [follows the release process](https://forge.rust-lang.org/release/process.html#master-bootstrap-update-tuesday) to update the stage0 compiler.
The only thing of note is 58651d1b31, which was flagged by clippy as a correctness fix. I think allowing that lint in our case makes sense, but it's worth to have a second pair of eyes on it.
r? `@Mark-Simulacrum`
remove 'unordered' atomic intrinsics
As their doc comment already indicates, these operations do not currently have a place in our memory model. The intrinsics were introduced to support a hack in compiler-builtins, but that hack recently got removed (see https://github.com/rust-lang/compiler-builtins/issues/788).
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.