[bootstrap] Add support for building gcc and libgccjit
As `@eholk` summarized below:
> From my understanding, this change would add libgccjit as an optional component to the Rust distribution. This library is licensed under GPLv2 and currently we do not have any other components under that license so it would be a new license, and one that is generally more restrictive than the other licenses we use.
It'll greatly improve the experience for anyone wanting to work on the GCC backend from the compiler.
Should help with https://github.com/rust-lang/rust/issues/124172.
Will unblock #124353.
r? `@Kobzol`
Rollup of 6 pull requests
Successful merges:
- #129320 (Fix crash when labeling arguments for call_once and friends)
- #130266 (target: default to the medium code model on LoongArch targets)
- #130297 (Dataflow cleanups)
- #130299 (Add set_dcx to ParseSess)
- #130301 (some fixes for clashing_extern_declarations lint)
- #130305 (Clippy: consider msrv for const context for const_float_bits_conv)
r? `@ghost`
`@rustbot` modify labels: rollup
Clippy: consider msrv for const context for const_float_bits_conv
When `const_float_bits_conv` was stabilized for 1.83.0, clippy lints started to be triggered in const context ignoring MSRV. This PR makes the lints trigger in const context only when the MSRV meets 1.83.0.
Fixes https://github.com/rust-lang/rust-clippy/issues/13383.
some fixes for clashing_extern_declarations lint
There were two issues with the clashing_extern_declarations lint:
- It would accept non-`repr(C)` structs as compatible with each other by comparing their fields in declaration order, but the fields could have different memory order (and with `-Zrandomize-layout`, this can really happen).
- It would accept two types as compatible if `compare_layouts` returns `true`, but that function actually just compared the *ABI*, not the fully layout -- and all sized structs with more than 2 fields have the same ABI (`Abi::Aggregate`), so this missed a *lot* of cases.
We don't currently have a clear spec for what we *want* to consider "clashing" and what is fine, so I otherwise kept the original logic. I hope to have a t-lang discussion about this at some point. But meanwhile, these changes seem like clear bugfixes.
Add set_dcx to ParseSess
After [this](https://github.com/rust-lang/rust/pull/126623) PR was merged, it is no longer possible to inject one's own `Emitter` in the way [described in the Compiler Development Guide](https://rustc-dev-guide.rust-lang.org/rustc-driver-getting-diagnostics.html). The reason is that the `dcx` field in `ParseSess` is no longer public, so it is not possible to update the `dcx` field with a `DiagCtxt` that contains one's own `Emitter` in the `psess_created` callback in `rustc_interface::Config`. The only way I have found to insert my own `DiagCtxt` is by creating an entirely new `ParseSess` and replacing the old one. This is not a good solution as the original `ParseSess` contains fields I would like to keep. (In my case the problem is that I lose the `cfg` and `check-cfg` fields of the original.)
The solution proposed in this PR is to add a `set_dcx` method to `ParseSess`. Per my limited understanding of the rustc codebase this should be fine as `set_dcx` requires a mutable reference to `ParseSess`, which is as far as I know only available in the `psess_created` callback (outside of `rustc_interface::run_compiler`).
If this PR is accepted, I will create a new PR to update the aforementioned example in the Compiler Development Guide.
target: default to the medium code model on LoongArch targets
The Rust LoongArch targets have been using the default LLVM code model so far, which is "small" in LLVM-speak and "normal" in LoongArch-speak. As described in the "Code Model" section of LoongArch ELF psABI spec v20231219 [1], one can only make function calls as far as ±128MiB with the "normal" code model; this is insufficient for very large software containing Rust components that needs to be linked into the big text section, such as Chromium.
Because:
* we do not want to ask users to recompile std if they are to build such software,
* objects compiled with larger code models can be linked with those with smaller code models without problems, and
* the "medium" code model is comparable to the "small"/"normal" one performance-wise (same data access pattern; each function call becomes 2-insn long and indirect, but this may be relaxed back into the direct 1-insn form in a future LLVM version), but is able to perform function calls within ±128GiB,
it is better to just switch the targets to the "medium" code model, which is also "medium" in LLVM-speak.
Relands [2]: #120661
[1]: https://github.com/loongson/la-abi-specs/blob/v2.30/laelf.adoc#code-models
[2]: https://github.com/rust-lang/rust/issues/121289#issuecomment-2333687396
Fix crash when labeling arguments for call_once and friends
When calling a method on Fn* traits explicitly, argument diagnostics should point at the called method (eg Fn::call_once), not the underlying callee.
This PR makes 3 main changes:
* It uses TupleArguments to detect if the user called a Fn* method directly (`my_fn.call_once(…)`) or implicitly (`my_fn(…)`). If it was explicit, argument diagnostics should point at the call_once method, not the underlying callable.
* The previous state was causing confusion between the two arguments lists (which could be different lengths), causing an out-of-bounds slice indexing in #128848. I added a length assert to capture the requirement in case this regresses or happens in another case.
* Unfortunately, this assert tripped when the required arguments information was not available (`self.get_hir_params_with_generics` was returning an empty Vec), so I've updated that to return None when that information is not available. (cc `@strottos` if you have any comments, since you added this function in #121595) Sorry this causes a bunch of indentation changes, recommend reviewing [ignoring whitespace](https://github.com/rust-lang/rust/pull/129320/files?w=1).)
This is my first rustc PR, so please call out if you'd like this split into more commits (or PRs), style nits, etc. I will add a few comments/questions inline. Thank you!
Fixes#128848
./miri run: directly run binary instead of using 'cargo run'
This avoids re-building miri without dev dependencies, so it makes `./miri run` a lot faster if `./miri test` was already executed before.
skip target sanity check when it's a `local-rebuild`
Running the stage0 target sanity check on the newly built compiler can result in errors and incorrect assumptions.
Resolves#130242
Don't leave debug locations for constants sitting on the builder indefinitely
Because constants are currently emitted *before* the prologue, leaving the debug location on the IRBuilder spills onto other instructions in the prologue and messes up both line numbers as well as the point LLVM chooses to be the prologue end.
Example LLVM IR (irrelevant IR elided):
Before:
```
define internal { i64, i64 } `@_ZN3tmp3Foo18var_return_opt_try17he02116165b0fc08cE(ptr` align 8 %self) !dbg !347 { start:
%self.dbg.spill = alloca [8 x i8], align 8
%_0 = alloca [16 x i8], align 8
%residual.dbg.spill = alloca [0 x i8], align 1
#dbg_declare(ptr %residual.dbg.spill, !353, !DIExpression(), !357)
store ptr %self, ptr %self.dbg.spill, align 8, !dbg !357
#dbg_declare(ptr %self.dbg.spill, !350, !DIExpression(), !358)
```
After:
```
define internal { i64, i64 } `@_ZN3tmp3Foo18var_return_opt_try17h00b17d08874ddd90E(ptr` align 8 %self) !dbg !347 { start:
%self.dbg.spill = alloca [8 x i8], align 8
%_0 = alloca [16 x i8], align 8
%residual.dbg.spill = alloca [0 x i8], align 1
#dbg_declare(ptr %residual.dbg.spill, !353, !DIExpression(), !357)
store ptr %self, ptr %self.dbg.spill, align 8
#dbg_declare(ptr %self.dbg.spill, !350, !DIExpression(), !358)
```
Note in particular how !357 from %residual.dbg.spill's dbg_declare no longer falls through onto the store to %self.dbg.spill. This fixes argument values at entry when the constant is a ZST (e.g. `<Option as Try>::Residual`). This fixes#130003 (but note that it does *not* fix issues with argument values and non-ZST constants, which emit their own stores that have debug info on them, like #128945).
r? `@michaelwoerister`
Revert #130040 - unify llvm-bitcode-linker, wasm-component-ld and llvm-tools logics
This is a revert of #130040 to fix#130291 which is preventing installing nightly with the llvm-tools component due to a conflict with the `bin/llc` file which exists in both the rustc and llvm-tools components.
Rescope temp lifetime in if-let into IfElse with migration lint
Tracking issue #124085
This PR shortens the temporary lifetime to cover only the pattern matching and consequent branch of a `if let`.
At the expression location, means that the lifetime is shortened from previously the deepest enclosing block or statement in Edition 2021. This warrants an Edition change.
Coming with the Edition change, this patch also implements an edition lint to warn about the change and a safe rewrite suggestion to preserve the 2021 semantics in most cases.
Related to #103108.
Related crater runs: https://github.com/rust-lang/rust/pull/129466.
Fix anon const def-creation when macros are involved
Fixes#128016.
Ever since #125915, some `ast::AnonConst`s turn into `hir::ConstArgKind::Path`s,
which don't have associated `DefId`s. To deal with the fact that we don't have
resolution information in `DefCollector`, we decided to implement a process
where if the anon const *appeared* to be trivial (i.e., `N` or `{ N }`), we
would avoid creating a def for it in `DefCollector`. If later, in AST lowering,
we realized it turned out to be a unit struct literal, or we were lowering it
to something that didn't use `hir::ConstArg`, we'd create its def there.
However, let's say we have a macro `m!()` that expands to a reference to a free
constant `FOO`. If we use `m!()` in the body of an anon const (e.g., `Foo<{ m!() }>`),
then in def collection, it appears to be a nontrivial anon const and we create
a def. But the macro expands to something that looks like a trivial const arg,
but is not, so in AST lowering we "fix" the mistake we assumed def collection
made and create a def for it. This causes a duplicate definition ICE.
The long-term fix for this is to delay the creation of defs for all expression-like
nodes until AST lowering (see #128844 for an incomplete attempt at this). This
would avoid issues like this one that are caused by hacky workarounds. However,
doing this uncovers a pre-existing bug with opaque types that is quite involved
to fix (see #129023).
In the meantime, this PR fixes the bug by delaying def creation for anon consts
whose bodies are macro invocations until after we expand the macro and know
what is inside it. This is accomplished by adding information to create the
anon const's def to the data in `Resolver.invocation_parents`.
r? `@BoxyUwU`
No analysis needs `Copy`, and `MaybeBorrowedLocals` is the only analysis
that needs `Clone`. In `locals_live_across_suspend_points` it gets
cloned so it can be used within a `MaybeRequiresStorage`.
