rustc_errors: let `DiagnosticBuilder::emit` return a "guarantee of emission".
That is, `DiagnosticBuilder` is now generic over the return type of `.emit()`, so we'll now have:
* `DiagnosticBuilder<ErrorReported>` for error (incl. fatal/bug) diagnostics
* can only be created via a `const L: Level`-generic constructor, that limits allowed variants via a `where` clause, so not even `rustc_errors` can accidentally bypass this limitation
* asserts `diagnostic.is_error()` on emission, just in case the construction restriction was bypassed (e.g. by replacing the whole `Diagnostic` inside `DiagnosticBuilder`)
* `.emit()` returns `ErrorReported`, as a "proof" token that `.emit()` was called
(though note that this isn't a real guarantee until after completing the work on
#69426)
* `DiagnosticBuilder<()>` for everything else (warnings, notes, etc.)
* can also be obtained from other `DiagnosticBuilder`s by calling `.forget_guarantee()`
This PR is a companion to other ongoing work, namely:
* #69426
and it's ongoing implementation:
#93222
the API changes in this PR are needed to get statically-checked "only errors produce `ErrorReported` from `.emit()`", but doesn't itself provide any really strong guarantees without those other `ErrorReported` changes
* #93244
would make the choices of API changes (esp. naming) in this PR fit better overall
In order to be able to let `.emit()` return anything trustable, several changes had to be made:
* `Diagnostic`'s `level` field is now private to `rustc_errors`, to disallow arbitrary "downgrade"s from "some kind of error" to "warning" (or anything else that doesn't cause compilation to fail)
* it's still possible to replace the whole `Diagnostic` inside the `DiagnosticBuilder`, sadly, that's harder to fix, but it's unlikely enough that we can paper over it with asserts on `.emit()`
* `.cancel()` now consumes `DiagnosticBuilder`, preventing `.emit()` calls on a cancelled diagnostic
* it's also now done internally, through `DiagnosticBuilder`-private state, instead of having a `Level::Cancelled` variant that can be read (or worse, written) by the user
* this removes a hazard of calling `.cancel()` on an error then continuing to attach details to it, and even expect to be able to `.emit()` it
* warnings were switched to *only* `can_emit_warnings` on emission (instead of pre-cancelling early)
* `struct_dummy` was removed (as it relied on a pre-`Cancelled` `Diagnostic`)
* since `.emit()` doesn't consume the `DiagnosticBuilder` <sub>(I tried and gave up, it's much more work than this PR)</sub>,
we have to make `.emit()` idempotent wrt the guarantees it returns
* thankfully, `err.emit(); err.emit();` can return `ErrorReported` both times, as the second `.emit()` call has no side-effects *only* because the first one did do the appropriate emission
* `&mut Diagnostic` is now used in a lot of function signatures, which used to take `&mut DiagnosticBuilder` (in the interest of not having to make those functions generic)
* the APIs were already mostly identical, allowing for low-effort porting to this new setup
* only some of the suggestion methods needed some rework, to have the extra `DiagnosticBuilder` functionality on the `Diagnostic` methods themselves (that change is also present in #93259)
* `.emit()`/`.cancel()` aren't available, but IMO calling them from an "error decorator/annotator" function isn't a good practice, and can lead to strange behavior (from the caller's perspective)
* `.downgrade_to_delayed_bug()` was added, letting you convert any `.is_error()` diagnostic into a `delay_span_bug` one (which works because in both cases the guarantees available are the same)
This PR should ideally be reviewed commit-by-commit, since there is a lot of fallout in each.
r? `@estebank` cc `@Manishearth` `@nikomatsakis` `@mark-i-m`
Partially move cg_ssa towards using a single builder
Not all codegen backends can handle hopping between blocks well. For example Cranelift requires blocks to be terminated before switching to building a new block. Rust-gpu requires a `RefCell` to allow hopping between blocks and cg_gcc currently has a buggy implementation of hopping between blocks. This PR reduces the amount of cases where cg_ssa switches between blocks before they are finished and mostly fixes the block hopping in cg_gcc. (~~only `scalar_to_backend` doesn't handle it correctly yet in cg_gcc~~ fixed that one.)
`@antoyo` please review the cg_gcc changes.
Fix several asm! related issues
This is a combination of several fixes, each split into a separate commit. Splitting these into PRs is not practical since they conflict with each other.
Fixes#92378Fixes#85247
r? ``@nagisa``
The previous approach of checking for the reserve-r9 target feature
didn't actually work because LLVM only sets this feature very late when
initializing the per-function subtarget.
Move ty::print methods to Drop-based scope guards
Primary goal is reducing codegen of the TLS access for each closure, which shaves ~3 seconds of bootstrap time over rustc as a whole.
Adopt let else in more places
Continuation of #89933, #91018, #91481, #93046, #93590, #94011.
I have extended my clippy lint to also recognize tuple passing and match statements. The diff caused by fixing it is way above 1 thousand lines. Thus, I split it up into multiple pull requests to make reviewing easier. This is the biggest of these PRs and handles the changes outside of rustdoc, rustc_typeck, rustc_const_eval, rustc_trait_selection, which were handled in PRs #94139, #94142, #94143, #94144.
Guard against unwinding in cleanup code
Currently the only safe guard we have against double unwind is the panic count (which is local to Rust). When double unwinds indeed happen (e.g. C++ exception + Rust panic, or two C++ exceptions), then the second unwind actually goes through and the first unwind is leaked. This can cause UB. cc rust-lang/project-ffi-unwind#6
E.g. given the following C++ code:
```c++
extern "C" void foo() {
throw "A";
}
extern "C" void execute(void (*fn)()) {
try {
fn();
} catch(...) {
}
}
```
This program is well-defined to terminate:
```c++
struct dtor {
~dtor() noexcept(false) {
foo();
}
};
void a() {
dtor a;
dtor b;
}
int main() {
execute(a);
return 0;
}
```
But this Rust code doesn't catch the double unwind:
```rust
extern "C-unwind" {
fn foo();
fn execute(f: unsafe extern "C-unwind" fn());
}
struct Dtor;
impl Drop for Dtor {
fn drop(&mut self) {
unsafe { foo(); }
}
}
extern "C-unwind" fn a() {
let _a = Dtor;
let _b = Dtor;
}
fn main() {
unsafe { execute(a) };
}
```
To address this issue, this PR adds an unwind edge to an abort block, so that the Rust example aborts. This is similar to how clang guards against double unwind (except clang calls terminate per C++ spec and we abort).
The cost should be very small; it's an additional trap instruction (well, two for now, since we use TrapUnreachable, but that's a different issue) for each function with landing pads; if LLVM gains support to encode "abort/terminate" info directly in LSDA like GCC does, then it'll be free. It's an additional basic block though so compile time may be worse, so I'd like a perf run.
r? `@ghost`
`@rustbot` label: F-c_unwind
Specifically, rename the `Const` struct as `ConstS` and re-introduce `Const` as
this:
```
pub struct Const<'tcx>(&'tcx Interned<ConstS>);
```
This now matches `Ty` and `Predicate` more closely, including using
pointer-based `eq` and `hash`.
Notable changes:
- `mk_const` now takes a `ConstS`.
- `Const` was copy, despite being 48 bytes. Now `ConstS` is not, so need a
we need separate arena for it, because we can't use the `Dropless` one any
more.
- Many `&'tcx Const<'tcx>`/`&Const<'tcx>` to `Const<'tcx>` changes
- Many `ct.ty` to `ct.ty()` and `ct.val` to `ct.val()` changes.
- Lots of tedious sigil fiddling.
Specifically, change `Ty` from this:
```
pub type Ty<'tcx> = &'tcx TyS<'tcx>;
```
to this
```
pub struct Ty<'tcx>(Interned<'tcx, TyS<'tcx>>);
```
There are two benefits to this.
- It's now a first class type, so we can define methods on it. This
means we can move a lot of methods away from `TyS`, leaving `TyS` as a
barely-used type, which is appropriate given that it's not meant to
be used directly.
- The uniqueness requirement is now explicit, via the `Interned` type.
E.g. the pointer-based `Eq` and `Hash` comes from `Interned`, rather
than via `TyS`, which wasn't obvious at all.
Much of this commit is boring churn. The interesting changes are in
these files:
- compiler/rustc_middle/src/arena.rs
- compiler/rustc_middle/src/mir/visit.rs
- compiler/rustc_middle/src/ty/context.rs
- compiler/rustc_middle/src/ty/mod.rs
Specifically:
- Most mentions of `TyS` are removed. It's very much a dumb struct now;
`Ty` has all the smarts.
- `TyS` now has `crate` visibility instead of `pub`.
- `TyS::make_for_test` is removed in favour of the static `BOOL_TY`,
which just works better with the new structure.
- The `Eq`/`Ord`/`Hash` impls are removed from `TyS`. `Interned`s impls
of `Eq`/`Hash` now suffice. `Ord` is now partly on `Interned`
(pointer-based, for the `Equal` case) and partly on `TyS`
(contents-based, for the other cases).
- There are many tedious sigil adjustments, i.e. adding or removing `*`
or `&`. They seem to be unavoidable.
Split `pauth` target feature
Per discussion on https://github.com/rust-lang/rust/issues/86941 we'd like to split `pauth` into `paca` and `pacg` in order to better support possible future environments that only have the keys available for address or generic authentication. At the moment LLVM has the one `pauth` target_feature while Linux presents separate `paca` and `pacg` flags for feature detection.
Because the use of [target_feature](https://rust-lang.github.io/rfcs/2045-target-feature.html) will "allow the compiler to generate code under the assumption that this code will only be reached in hosts that support the feature", it does not make sense to simply translate `paca` into the LLVM feature `pauth`, as it will generate code as if `pacg` is available.
To accommodate this we error if only one of the two features is present. If LLVM splits them in the future we can remove this restriction without making a breaking change.
r? ```@Amanieu```
Ensure that queries only return Copy types.
This should pervent the perf footgun of returning a result with an expensive `Clone` impl (like a `Vec` of a hash map).
I went for the stupid solution of allocating on an arena everything that was not `Copy`. Some query results could be made Copy easily, but I did not really investigate.
debuginfo: Fix DW_AT_containing_type vtable debuginfo regression
This PR brings back the `DW_AT_containing_type` attribute for vtables after it has accidentally been removed in #89597.
It also implements a more accurate description of vtables. Instead of describing them as an array of void pointers, the compiler will now emit a struct type description with a field for each entry of the vtable.
r? ``@wesleywiser``
This PR should fix issue https://github.com/rust-lang/rust/issues/93164.
~~The PR is blocked on https://github.com/rust-lang/rust/pull/93154 because both of them modify the `codegen/debug-vtable.rs` test case.~~
Stabilize `-Z instrument-coverage` as `-C instrument-coverage`
(Tracking issue for `instrument-coverage`: https://github.com/rust-lang/rust/issues/79121)
This PR stabilizes support for instrumentation-based code coverage, previously provided via the `-Z instrument-coverage` option. (Continue supporting `-Z instrument-coverage` for compatibility for now, but show a deprecation warning for it.)
Many, many people have tested this support, and there are numerous reports of it working as expected.
Move the documentation from the unstable book to stable rustc documentation. Update uses and documentation to use the `-C` option.
Addressing questions raised in the tracking issue:
> If/when stabilized, will the compiler flag be updated to -C instrument-coverage? (If so, the -Z variant could also be supported for some time, to ease migrations for existing users and scripts.)
This stabilization PR updates the option to `-C` and keeps the `-Z` variant to ease migration.
> The Rust coverage implementation depends on (and automatically turns on) -Z symbol-mangling-version=v0. Will stabilizing this feature depend on stabilizing v0 symbol-mangling first? If so, what is the current status and timeline?
This stabilization PR depends on https://github.com/rust-lang/rust/pull/90128 , which stabilizes `-C symbol-mangling-version=v0` (but does not change the default symbol-mangling-version).
> The Rust coverage implementation implements the latest version of LLVM's Coverage Mapping Format (version 4), which forces a dependency on LLVM 11 or later. A compiler error is generated if attempting to compile with coverage, and using an older version of LLVM.
Given that LLVM 13 has now been released, requiring LLVM 11 for coverage support seems like a reasonable requirement. If people don't have at least LLVM 11, nothing else breaks; they just can't use coverage support. Given that coverage support currently requires a nightly compiler and LLVM 11 or newer, allowing it on a stable compiler built with LLVM 11 or newer seems like an improvement.
The [tracking issue](https://github.com/rust-lang/rust/issues/79121) and the [issue label A-code-coverage](https://github.com/rust-lang/rust/labels/A-code-coverage) link to a few open issues related to `instrument-coverage`, but none of them seem like showstoppers. All of them seem like improvements and refinements we can make after stabilization.
The original `-Z instrument-coverage` support went through a compiler-team MCP at https://github.com/rust-lang/compiler-team/issues/278 . Based on that, `@pnkfelix` suggested that this needed a stabilization PR and a compiler-team FCP.
debuginfo: Make sure that type names for closure and generator environments are unique in debuginfo.
Before this change, closure/generator environments coming from different instantiations of the same generic function were all assigned the same name even though they were distinct types with potentially different data layout. Now we append the generic arguments of the originating function to the type name.
This commit also emits `{closure_env#0}` as the name of these types in order to disambiguate them from the accompanying closure function (which keeps being called `{closure#0}`). Previously both were assigned the same name.
NOTE: Changing debuginfo names like this can break pretty printers and other debugger plugins. I think it's OK in this particular case because the names we are changing were ambiguous anyway. In general though it would be great to have a process for doing changes like these.
Before this change, closure/generator environments coming from different
instantiations of the same generic function were all assigned the same
name even though they were distinct types with potentially different data
layout. Now we append the generic arguments of the originating function
to the type name.
This commit also emits '{closure_env#0}' as the name of these types in
order to disambiguate them from the accompanying closure function
'{closure#0}'. Previously both were assigned the same name.
Add `intrinsics::const_deallocate`
Tracking issue: #79597
Related: #91884
This allows deallocation of a memory allocated by `intrinsics::const_allocate`. At the moment, this can be only used to reduce memory usage, but in the future this may be useful to detect memory leaks (If an allocated memory remains after evaluation, raise an error...?).
Print a helpful message if unwinding aborts when it reaches a nounwind function
This is implemented by routing `TerminatorKind::Abort` back through the panic handler, but with a special flag in the `PanicInfo` which indicates that the panic handler should *not* attempt to unwind the stack and should instead abort immediately.
This is useful for the planned change in https://github.com/rust-lang/lang-team/issues/97 which would make `Drop` impls `nounwind` by default.
### Code
```rust
#![feature(c_unwind)]
fn panic() {
panic!()
}
extern "C" fn nounwind() {
panic();
}
fn main() {
nounwind();
}
```
### Before
```
$ ./test
thread 'main' panicked at 'explicit panic', test.rs:4:5
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
Illegal instruction (core dumped)
```
### After
```
$ ./test
thread 'main' panicked at 'explicit panic', test.rs:4:5
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
thread 'main' panicked at 'panic in a function that cannot unwind', test.rs:7:1
stack backtrace:
0: 0x556f8f86ec9b - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hdccefe11a6ac4396
1: 0x556f8f88ac6c - core::fmt::write::he152b28c41466ebb
2: 0x556f8f85d6e2 - std::io::Write::write_fmt::h0c261480ab86f3d3
3: 0x556f8f8654fa - std::panicking::default_hook::{{closure}}::h5d7346f3ff7f6c1b
4: 0x556f8f86512b - std::panicking::default_hook::hd85803a1376cac7f
5: 0x556f8f865a91 - std::panicking::rust_panic_with_hook::h4dc1c5a3036257ac
6: 0x556f8f86f079 - std::panicking::begin_panic_handler::{{closure}}::hdda1d83c7a9d34d2
7: 0x556f8f86edc4 - std::sys_common::backtrace::__rust_end_short_backtrace::h5b70ed0cce71e95f
8: 0x556f8f865592 - rust_begin_unwind
9: 0x556f8f85a764 - core::panicking::panic_no_unwind::h2606ab3d78c87899
10: 0x556f8f85b910 - test::nounwind::hade6c7ee65050347
11: 0x556f8f85b936 - test::main::hdc6e02cb36343525
12: 0x556f8f85b7e3 - core::ops::function::FnOnce::call_once::h4d02663acfc7597f
13: 0x556f8f85b739 - std::sys_common::backtrace::__rust_begin_short_backtrace::h071d40135adb0101
14: 0x556f8f85c149 - std::rt::lang_start::{{closure}}::h70dbfbf38b685e93
15: 0x556f8f85c791 - std::rt::lang_start_internal::h798f1c0268d525aa
16: 0x556f8f85c131 - std::rt::lang_start::h476a7ee0a0bb663f
17: 0x556f8f85b963 - main
18: 0x7f64c0822b25 - __libc_start_main
19: 0x556f8f85ae8e - _start
20: 0x0 - <unknown>
thread panicked while panicking. aborting.
Aborted (core dumped)
```
- Fix style errors.
- L4-bender does not yet support dynamic linking.
- Stack unwinding is not yet supported for x86_64-unknown-l4re-uclibc.
For now, just abort on panics.
- Use GNU-style linker options where possible. As suggested by review:
- Use standard GNU-style ld syntax for relro flags.
- Use standard GNU-style optimization flags and logic.
- Use standard GNU-style ld syntax for --subsystem.
- Don't read environment variables in L4Bender linker. Thanks to
CARGO_ENCODED_RUSTFLAGS introduced in #9601, l4-bender's arguments can
now be passed from the L4Re build system without resorting to custom
parsing of environment variables.
Update some rustc dependencies to deduplicate them
This PR updates `rand` and `itertools` in rustc (not the whole workspace) in order to deduplicate them (and hopefully slightly improve compile times).
~~Currently, `object` is still duplicated, but https://github.com/rust-lang/thorin/pull/15 and updating `thorin` in the future will remove the use of version 0.27.~~ Update: Thorin 0.2 has now been released, and this PR updates `rustc_codegen_ssa` to use it and deduplicate the `object` crate.
There's a final tiny rustc dependency, `cfg-if`, which will be left: as both versions 0.1.x and 1.0 looked to be heavily depended on, they will require a few cascading updates to be removed.
Stabilize `-Z print-link-args` as `--print link-args`
We have stable options for adding linker arguments; we should have a
stable option to help debug linker arguments.
Add documentation for the new option. In the documentation, make it clear that
the *exact* format of the output is not a stable guarantee.
Use iterator instead of recursion in `codegen_place`
This PR fixes the FIXME in `codegen_place` about using iterator instead of recursion when processing the `projection` field in `mir::PlaceRef`. At the same time, it also reduces the right drift.
Improve SIMD casts
* Allows `simd_cast` intrinsic to take `usize` and `isize`
* Adds `simd_as` intrinsic, which is the same as `simd_cast` except for saturating float-to-int conversions (matching the behavior of `as`).
cc `@workingjubilee`
Remove LLVMRustMarkAllFunctionsNounwind
This was originally introduced in #10916 as a way to remove all landing
pads when performing LTO. However this is no longer necessary today
since rustc properly marks all functions and call-sites as nounwind
where appropriate.
In fact this is incorrect in the presence of `extern "C-unwind"` which
must create a landing pad when compiled with `-C panic=abort` so that
foreign exceptions are caught and properly turned into aborts.
Remove deprecated LLVM-style inline assembly
The `llvm_asm!` was deprecated back in #87590 1.56.0, with intention to remove
it once `asm!` was stabilized, which already happened in #91728 1.59.0. Now it
is time to remove `llvm_asm!` to avoid continued maintenance cost.
Closes#70173.
Closes#92794.
Closes#87612.
Closes#82065.
cc `@rust-lang/wg-inline-asm`
r? `@Amanieu`
Generate more precise generator names
Currently all generators are named with a `generator$N` suffix, regardless of where they come from. This means an `async fn` shows up as a generator in stack traces, which can be surprising to async programmers since they should not need to know that async functions are implementated using generators.
This change generators a different name depending on the generator kind, allowing us to tell whether the generator is the result of an async block, an async closure, an async fn, or a plain generator.
r? `@tmandry`
cc `@michaelwoerister` `@wesleywiser` `@dpaoliello`
This was originally introduced in #10916 as a way to remove all landing
pads when performing LTO. However this is no longer necessary today
since rustc properly marks all functions and call-sites as nounwind
where appropriate.
In fact this is incorrect in the presence of `extern "C-unwind"` which
must create a landing pad when compiled with `-C panic=abort` so that
foreign exceptions are caught and properly turned into aborts.
Currently all generators are named with a `generator$N` suffix,
regardless of where they come from. This means an `async fn` shows up as
a generator in stack traces, which can be surprising to async
programmers since they should not need to know that async functions are
implementated using generators.
This change generators a different name depending on the generator kind,
allowing us to tell whether the generator is the result of an async
block, an async closure, an async fn, or a plain generator.
Make rlib metadata strip works with MIPSr6 architecture
Because MIPSr6 has many differences with previous MIPSr2 arch, the previous rlib metadata stripping code in `rustc_codegen_ssa` is only for MIPSr2/r3/r5 (which share the same elf e_flags).
This commit fixed this problem. It makes `rustc_codegen_ssa` happy when compiling rustc for MIPSr6 target or hosts.
e_flags REF: e356027016/llvm/include/llvm/BinaryFormat/ELF.h (L562)
The field is also renamed from `ident` to `name. In most cases,
we don't actually need the `Span`. A new `ident` method is added
to `VariantDef` and `FieldDef`, which constructs the full `Ident`
using `tcx.def_ident_span()`. This method is used in the cases
where we actually need an `Ident`.
This makes incremental compilation properly track changes
to the `Span`, without all of the invalidations caused by storing
a `Span` directly via an `Ident`.
Consolidate checking for msvc when generating debuginfo
If the target we're generating code for is msvc, then we do two main
things differently: we generate type names in a C++ style instead of a
Rust style and we generate debuginfo for enums differently.
I've refactored the code so that there is one function
(`cpp_like_debuginfo`) which determines if we should use the C++ style
of naming types and other debuginfo generation or the regular Rust one.
r? ``@michaelwoerister``
This PR is not urgent so please don't let it interrupt your holidays! 🎄🎁
If the target we're generating code for is msvc, then we do two main
things differently: we generate type names in a C++ style instead of a
Rust style and we generate debuginfo for enums differently.
I've refactored the code so that there is one function
(`cpp_like_debuginfo`) which determines if we should use the C++ style
of naming types and other debuginfo generation or the regular Rust one.
Because MIPSr6 has many differences with previous MIPSr2 arch, the previous rlib metadata stripping code in `rustc_codegen_ssa` is only for MIPSr2/r3/r5 (which share the same elf e_flags).
This commit fixed this problem. It makes `rustc_codegen_ssa` happy when compiling rustc for MIPSr6 target or hosts.
`thorin` is a Rust implementation of a DWARF packaging utility that
supports reading DWARF objects from archive files (i.e. rlibs) and
therefore is better suited for integration into rustc.
Signed-off-by: David Wood <david.wood@huawei.com>
In #79570, `-Z split-dwarf-kind={none,single,split}` was replaced by `-C
split-debuginfo={off,packed,unpacked}`. `-C split-debuginfo`'s packed
and unpacked aren't exact parallels to single and split, respectively.
On Unix, `-C split-debuginfo=packed` will put debuginfo into object
files and package debuginfo into a DWARF package file (`.dwp`) and
`-C split-debuginfo=unpacked` will put debuginfo into dwarf object files
and won't package it.
In the initial implementation of Split DWARF, split mode wrote sections
which did not require relocation into a DWARF object (`.dwo`) file which
was ignored by the linker and then packaged those DWARF objects into
DWARF packages (`.dwp`). In single mode, sections which did not require
relocation were written into object files but ignored by the linker and
were not packaged. However, both split and single modes could be
packaged or not, the primary difference in behaviour was where the
debuginfo sections that did not require link-time relocation were
written (in a DWARF object or the object file).
This commit re-introduces a `-Z split-dwarf-kind` flag, which can be
used to pick between split and single modes when `-C split-debuginfo` is
used to enable Split DWARF (either packed or unpacked).
Signed-off-by: David Wood <david.wood@huawei.com>
Actually set IMAGE_SCN_LNK_REMOVE for .rmeta
The code intended to set the IMAGE_SCN_LNK_REMOVE flag for the
.rmeta section, however the value of this flag was set to zero.
Instead use the actual value provided by the object crate.
This dates back to the original introduction of this code in
PR #84449, so we were never setting this flag. As I'm not on
Windows, I'm not sure whether that means we were embedding .rmeta
into executables, or whether the section ended up getting stripped
for some other reason.
Remove `NullOp::Box`
Follow up of #89030 and MCP rust-lang/compiler-team#460.
~1 month later nothing seems to be broken, apart from a small regression that #89332 (1aac85bb716c09304b313d69d30d74fe7e8e1a8e) shows could be regained by remvoing the diverging path, so it shall be safe to continue and remove `NullOp::Box` completely.
r? `@jonas-schievink`
`@rustbot` label T-compiler
Continue supporting -Z instrument-coverage for compatibility for now,
but show a deprecation warning for it.
Update uses and documentation to use the -C option.
Move the documentation from the unstable book to stable rustc
documentation.
Mark drop calls in landing pads `cold` instead of `noinline`
Now that deferred inlining has been disabled in LLVM (#92110), this shouldn't cause catastrophic size blowup.
I confirmed that the test cases from https://github.com/rust-lang/rust/issues/41696#issuecomment-298696944 still compile quickly (<1s) after this change. ~Although note that I wasn't able to reproduce the original issue using a recent rustc/llvm with deferred inlining enabled, so those tests may no longer be representative. I was also unable to create a modified test case that reproduced the original issue.~ (edit: I reproduced it on CI by accident--the first commit timed out on the LLVM 12 builder, because I forgot to make it conditional on LLVM version)
r? `@nagisa`
cc `@arielb1` (this effectively reverts #42771 "mark calls in the unwind path as !noinline")
cc `@RalfJung` (fixes#46515)
edit: also fixes#87055
Allow loading LLVM plugins with both legacy and new pass manager
Opening a draft PR to get feedback and start discussion on this feature. There is already a codegen option `passes` which allow giving a list of LLVM pass names, however we currently can't use a LLVM pass plugin (as described here : https://llvm.org/docs/WritingAnLLVMPass.html), the only available passes are the LLVM built-in ones.
The proposed modification would be to add another codegen option `pass-plugins`, which can be set with a list of paths to shared library files. These libraries are loaded using the LLVM function `PassPlugin::Load`, which calls the expected symbol `lvmGetPassPluginInfo`, and register the pipeline parsing and optimization callbacks.
An example usage with a single plugin and 3 passes would look like this in the `.cargo/config`:
```toml
rustflags = [
"-C", "pass-plugins=/tmp/libLLVMPassPlugin",
"-C", "passes=pass1 pass2 pass3",
]
```
This would give the same functionality as the opt LLVM tool directly integrated in rust build system.
Additionally, we can also not specify the `passes` option, and use a plugin which inserts passes in the optimization pipeline, as one could do using clang.
The `AggregateKind` enum ends up in the final mir `Body`. Currently,
any changes to `AdtDef` (regardless of how significant they are)
will legitimately cause the overall result of `optimized_mir` to change,
invalidating any codegen re-use involving that mir.
This will get worse once we start hashing the `Span` inside `FieldDef`
(which is itself contained in `AdtDef`).
To try to reduce these kinds of invalidations, this commit changes
`AggregateKind::Adt` to store just the `DefId`, instead of the full
`AdtDef`. This allows the result of `optimized_mir` to be unchanged
if the `AdtDef` changes in a way that doesn't actually affect any
of the MIR we build.
The code intended to set the IMAGE_SCN_LNK_REMOVE flag for the
.rmeta section, however the value of this flag was set to zero.
Instead use the actual value provided by the object crate.
This dates back to the original introduction of this code in
PR #84449, so we were never setting this flag. As I'm not on
Windows, I'm not sure whether that means we were embedding .rmeta
into executables, or whether the section ended up getting stripped
for some other reason.
Explicitly set no ELF flags for .rustc section
For a data section, the object crate will set the SHF_ALLOC by default, which is exactly what we don't want. Explicitly set sh_flags to zero to avoid this.
I checked with `objdump -h` that this produces the right flags for ELF.
Fixes#92013.
Remove `SymbolStr`
This was originally proposed in https://github.com/rust-lang/rust/pull/74554#discussion_r466203544. As well as removing the icky `SymbolStr` type, it allows the removal of a lot of `&` and `*` occurrences.
Best reviewed one commit at a time.
r? `@oli-obk`
Rollup of 7 pull requests
Successful merges:
- #91566 (Apply path remapping to DW_AT_GNU_dwo_name when producing split DWARF)
- #91926 (Remove `in_band_lifetimes` from `rustc_metadata`)
- #91931 (Remove `in_band_lifetimes` from `rustc_codegen_llvm`)
- #92024 (rustc_codegen_llvm: Give each codegen unit a unique DWARF name on all platforms, not just Apple ones.)
- #92037 (Use a const ParamEnv when in default_method_body_is_const)
- #92047 (Set `RUST_BACKTRACE=0` when running location-detail tests)
- #92050 (Add a space and 2 grave accents )
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
For a data section, the object crate will set the SHF_ALLOC by
default, which is exactly what we don't want. Explicitly set
sh_flags to zero to avoid this.
Apply path remapping to DW_AT_GNU_dwo_name when producing split DWARF
`--remap-path-prefix` doesn't apply to paths to `.o` (in case of packed) or `.dwo` (in case of unpacked) files in `DW_AT_GNU_dwo_name`. GCC also has this bug https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91888
DF_ORIGIN flag signifies that the object being loaded may make reference to the $ORIGIN substitution string.
Some implementations are just ignoring DF_ORIGIN and do substitution for $ORIGIN if present (whatever DF_ORIGIN pr
Set the flag inconditionally if rpath is wanted.
Remove `in_band_lifetimes` from `rustc_codegen_ssa`
See #91867 for more information.
In `compiler/rustc_codegen_ssa/src/coverageinfo/map.rs`, there are several functions with an explicit `'a` lifetime but only a single `&'a self` parameter. These lifetimes should be redundant given lifetime elision, unless the existential `impl Iterator` has weird issues regarding that. Should the redundant lifetimes be removed?
The resulting profile will include the crate name and will be stored in
the `--out-dir` directory.
This implementation makes it convenient to use LLVM time trace together
with cargo, in the contrast to the previous implementation which would
overwrite profiles or store them in `.cargo/registry/..`.
asm: Allow using r9 (ARM) and x18 (AArch64) if they are not reserved by the current target
This supersedes https://github.com/rust-lang/rust/pull/88879.
cc `@Skirmisher`
r? `@joshtriplett`
Remove the reg_thumb register class for asm! on ARM
Also restricts r8-r14 from being used on Thumb1 targets as per #90736.
cc ``@Lokathor``
r? ``@joshtriplett``
Use object crate for .rustc metadata generation
We already use the object crate for generating uncompressed .rmeta
metadata object files. This switches the generation of compressed
.rustc object files to use the object crate as well. These have
slightly different requirements in that .rmeta should be completely
excluded from any final compilation artifacts, while .rustc should
be part of shared objects, but not loaded into memory.
The primary motivation for this change is #90326: In LLVM 14, the
current way of setting section flags (and in particular, preventing
the setting of SHF_ALLOC) will no longer work. There are other ways
we could work around this, but switching to the object crate seems
like the most elegant, as we already use it for .rmeta, and as it
makes this independent of the codegen backend. In particular, we
don't need separate handling in codegen_llvm and codegen_gcc.
codegen_cranelift should be able to reuse the implementation as
well, though I have omitted that here, as it is not based on
codegen_ssa.
This change mostly extracts the existing code for .rmeta handling
to allow using it for .rustc as well, and adjusts the codegen
infrastructure to handle the metadata object file separately: We
no longer create a backend-specific module for it, and directly
produce the compiled module instead.
This does not `fix` #90326 by itself yet, as .llvmbc will need to be
handled separately.
r? `@nagisa`
We already use the object crate for generating uncompressed .rmeta
metadata object files. This switches the generation of compressed
.rustc object files to use the object crate as well. These have
slightly different requirements in that .rmeta should be completely
excluded from any final compilation artifacts, while .rustc should
be part of shared objects, but not loaded into memory.
The primary motivation for this change is #90326: In LLVM 14, the
current way of setting section flags (and in particular, preventing
the setting of SHF_ALLOC) will no longer work. There are other ways
we could work around this, but switching to the object crate seems
like the most elegant, as we already use it for .rmeta, and as it
makes this independent of the codegen backend. In particular, we
don't need separate handling in codegen_llvm and codegen_gcc.
codegen_cranelift should be able to reuse the implementation as
well, though I have omitted that here, as it is not based on
codegen_ssa.
This change mostly extracts the existing code for .rmeta handling
to allow using it for .rustc as well, and adjust the codegen
infrastructure to handle the metadata object file separately: We
no longer create a backend-specific module for it, and directly
produce the compiled module instead.
This does not fix#90326 by itself yet, as .llvmbc will need to be
handled separately.
...because alignment is always nonzero.
This helps eliminate redundant runtime alignment checks, when a DST
is a field of a struct whose remaining fields have alignment 1.
Add support for LLVM coverage mapping format versions 5 and 6
This PR cherry-pick's Swatinem's initial commit in unsubmitted PR #90047.
My additional commit augments Swatinem's great starting point, but adds full support for LLVM
Coverage Mapping Format version 6, conditionally, if compiling with LLVM 13.
Version 6 requires adding the compilation directory when file paths are
relative, and since Rustc coverage maps use relative paths, we should
add the expected compilation directory entry.
Note, however, that with the compilation directory, coverage reports
from `llvm-cov show` can now report file names (when the report includes
more than one file) with the full absolute path to the file.
This would be a problem for test results, but the workaround (for the
rust coverage tests) is to include an additional `llvm-cov show`
parameter: `--compilation-dir=.`
Remove workaround for the forward progress handling in LLVM
this workaround was only needed for LLVM < 12 and the minimum LLVM version was updated to 12 in #90175
Fix ld64 flags
- The `-exported_symbols_list` argument appears to be malformed for `ld64` (if you are not going through `clang`).
- The `-dynamiclib` argument isn't support for `ld64`. It should be guarded behind a compiler flag.
These problems are fixed by these changes. I have also refactored the way linker arguments are generated to be ld/compiler agnostic and therefore less error prone.
These changes are necessary to support cross-compilation to darwin targets.
Leave -Z strip available temporarily as an alias, to avoid breaking
cargo until cargo transitions to using -C strip. (If the user passes
both, the -C version wins.)
This commit refactors linker argument generation to leverage a helper
function that abstracts away details governing how these arguments are
transformed and provided to the linker.
This fixes the misuse of the `-exported_symbols_list` when an ld-like
linker is used rather than a compiler. A compiler would expect
`-Wl,-exported_symbols_list,path` but ld would expect
`-exported_symbols_list` and `path` as two seperate arguments. Prior
to this change, an ld-like linker was given
`-exported_symbols_list,path`.
Linker arguments must transformed when Rust is interacting with the
linker through a compiler. This commit introduces a helper function
that abstracts away details of this transformation.
Record more artifact sizes during self-profiling.
This PR adds artifact size recording for
- "linked artifacts" (executables, RLIBs, dylibs, static libs)
- object files
- dwo files
- assembly files
- crate metadata
- LLVM bitcode files
- LLVM IR files
- codegen unit size estimates
Currently the identifiers emitted for these are hard-coded as string literals. Is it worth adding constants to https://github.com/rust-lang/measureme/blob/master/measureme/src/rustc.rs instead? We don't do that for query names and the like -- but artifact kinds might be more stable than query names.
enable `dotprod` target feature in arm
To implement `vdot` neon insturction in stdarch, we need to enable `dotprod` target feature in arm in rustc.
r? `@Amanieu`
Don't abort compilation after giving a lint error
The only reason to use `abort_if_errors` is when the program is so broken that either:
1. later passes get confused and ICE
2. any diagnostics from later passes would be noise
This is never the case for lints, because the compiler has to be able to deal with `allow`-ed lints.
So it can continue to lint and compile even if there are lint errors.
Closes https://github.com/rust-lang/rust/issues/82761. This is a WIP because I have a feeling it will exit with 0 even if there were lint errors; I don't have a computer that can build rustc locally at the moment.
The only reason to use `abort_if_errors` is when the program is so broken that either:
1. later passes get confused and ICE
2. any diagnostics from later passes would be noise
This is never the case for lints, because the compiler has to be able to deal with `allow`-ed lints.
So it can continue to lint and compile even if there are lint errors.
In https://reviews.llvm.org/D71059 LLVM 11, the time trace profiler was
extended to support multiple threads.
`timeTraceProfilerInitialize` creates a thread local profiler instance.
When a thread finishes `timeTraceProfilerFinishThread` moves a thread
local instance into a global collection of instances. Finally when all
codegen work is complete `timeTraceProfilerWrite` writes data from the
current thread local instance and the instances in global collection
of instances.
Previously, the profiler was intialized on a single thread only. Since
this thread performs no code generation on its own, the resulting
profile was empty.
Update LLVM codegen to initialize & finish time trace profiler on each
code generation thread.
