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
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.
