This commit introduces a `Limit` type which is used to ensure that all
comparisons against limits within the compiler are consistent (which can
result in ICEs if they aren't).
Signed-off-by: David Wood <david@davidtw.co>
Ensure that inliner inserts lifetime markers if they have been emitted during
codegen. Otherwise if allocas from inlined functions are merged together,
lifetime markers from one function might invalidate load & stores performed
by the other one.
Add Option to Force Unwind Tables
When panic != unwind, `nounwind` is added to all functions for a target.
This can cause issues when a panic happens with RUST_BACKTRACE=1, as
there needs to be a way to reconstruct the backtrace. There are three
possible sources of this information: forcing frame pointers (for which
an option exists already), debug info (for which an option exists), or
unwind tables.
Especially for embedded devices, forcing frame pointers can have code
size overheads (RISC-V sees ~10% overheads, ARM sees ~2-3% overheads).
In production code, it can be the case that debug info is not kept, so it is useful
to provide this third option, unwind tables, that users can use to
reconstruct the call stack. Reconstructing this stack is harder than
with frame pointers, but it is still possible.
---
This came up in discussion on #69890, and turned out to be a fairly simple addition.
r? @hanna-kruppe
When panic != unwind, `nounwind` is added to all functions for a target.
This can cause issues when a panic happens with RUST_BACKTRACE=1, as
there needs to be a way to reconstruct the backtrace. There are three
possible sources of this information: forcing frame pointers (for which
an option exists already), debug info (for which an option exists), or
unwind tables.
Especially for embedded devices, forcing frame pointers can have code
size overheads (RISC-V sees ~10% overheads, ARM sees ~2-3% overheads).
In code, it can be the case that debug info is not kept, so it is useful
to provide this third option, unwind tables, that users can use to
reconstruct the call stack. Reconstructing this stack is harder than
with frame pointers, but it is still possible.
This commit adds a compiler option which allows a user to force the
addition of unwind tables. Unwind tables cannot be disabled on targets
that require them for correctness, or when using `-C panic=unwind`.
Miri: unleash all feature gates
IMO it is silly to unleash features that do not even have a feature gate yet, but not unleash features that do. The only thing this achieves is making unleashed mode annoying to use as we have to figure out the feature flags to enable (and not always do the error messages say what that flag is).
Given that the point of `-Z unleash-the-miri-inside-of-you` is to debug the Miri internals, I see no good reason for this extra hurdle. I cannot imagine a situation where we'd use that flag, realize the program also requires some feature gate, and then be like "oh I guess if this feature is unstable I will do something else". Instead, we'll always just add that flag to the code as well, so requiring the flag achieves nothing.
r? @oli-obk @ecstatic-morse
Fixes https://github.com/rust-lang/rust/issues/71630
This lets us specify the default at the options declaration point,
instead of using `.unwrap(default)` or `None | Some(default)` at some
use point far away. It also makes the code more concise.
Add hash of source files in debug info
LLVM supports placing the hash of source files inside the debug info.
This information can be used by a debugger to verify that the source code matches
the executable.
This change adds support for both hash algorithms supported by LLVM, MD5 and SHA1, controlled by a target option.
* DWARF only supports MD5
* LLVM IR supports MD5 and SHA1 (and SHA256 in LLVM 11).
* CodeView (.PDB) supports MD5, SHA1, and SHA256.
Fixes#68980.
Tracking issue: #70401
rustc dev guide PR with further details: https://github.com/rust-lang/rustc-dev-guide/pull/623
Make the rustc respect the `-C codegen-units` flag in incremental mode.
This PR implements (the as of yet unapproved) major change proposal at https://github.com/rust-lang/compiler-team/issues/245. See the description there for background and rationale.
The changes are pretty straightforward and should be easy to rebase if the proposal gets accepted at some point.
r? @nikomatsakis cc @pnkfelix
Before this commit `-C codegen-units` would just get silently be
ignored if `-C incremental` was specified too. After this commit
one can control the number of codegen units generated during
incremental compilation. The default is rather high at 256, so most
crates won't see a difference unless explicitly opting into a lower
count.
windows-gnu: prefer system crt libraries if they are available
The origin of the issue is the fact Rust ships mingw-w64 libraries but no headers and prefers own libraries over the system ones.
This leads to situation when headers aren't compatible with libraries (mingw-w64 doesn't provide any forward compatibility and AFAIK backwards compatibility is guaranteed only within major release series).
It's easier to understand how this PR works when looking at the linker invocation before and with this PR: https://www.diffchecker.com/GEuYFmzo
It adds system libraries path before Rust libraries so the linker will prefer them.
It has potential issue when system has files with the same names as Rust but that could be avoided by moving Rust shipped mingw-w64 libraries from `lib/rustlib/x86_64-pc-windows-gnu/lib` to say `lib/rustlib/x86_64-pc-windows-gnu/lib/mingw`. Then adding linker paths in this order: Rust libraries, system libraries, Rust shipped mingw-w64 libraries.
Fixes#47048Fixes#49078Fixes#53454Fixes#60912
This change adds the x86_64-fuchsia and aarch64-fuchsia LLVM targets to
those allowed to invoke -Zsanitizer. Currently, the only overlap between
compiler_rt sanitizers supported by both rustc and Fuchsia is ASan.
