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Update the binary_asm_label documentation

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Disable a test that now only passes on x86 and make the link point to
the new (open) LLVM bug.
This commit is contained in:
Trevor Gross 2024-07-19 01:12:09 -05:00
parent 8410348b1c
commit 5686720a57
1 changed files with 23 additions and 9 deletions
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32
compiler/rustc_lint/src/builtin.rs
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@ -2740,8 +2740,9 @@ declare_lint! {
///
/// ### Example
///
/// ```rust,compile_fail
/// # #![feature(asm_experimental_arch)]
/// ```rust,ignore (fails on non-x86_64)
/// #![cfg(target_arch = "x86_64")]
///
/// use std::arch::asm;
///
/// fn main() {
@ -2751,19 +2752,32 @@ declare_lint! {
/// }
/// ```
///
/// {{produces}}
/// This will produce:
///
/// ```text
/// error: avoid using labels containing only the digits `0` and `1` in inline assembly
/// --> <source>:7:15
/// |
/// 7 | asm!("0: jmp 0b");
/// | ^ use a different label that doesn't start with `0` or `1`
/// |
/// = help: start numbering with `2` instead
/// = note: an LLVM bug makes these labels ambiguous with a binary literal number on x86
/// = note: see <https://github.com/llvm/llvm-project/issues/99547> for more information
/// = note: `#[deny(binary_asm_labels)]` on by default
/// ```
///
/// ### Explanation
///
/// A [LLVM bug] causes this code to fail to compile because it interprets the `0b` as a binary
/// literal instead of a reference to the previous local label `0`. Note that even though the
/// bug is marked as fixed, it only fixes a specific usage of intel syntax within standalone
/// files, not inline assembly. To work around this bug, don't use labels that could be
/// confused with a binary literal.
/// An [LLVM bug] causes this code to fail to compile because it interprets the `0b` as a binary
/// literal instead of a reference to the previous local label `0`. To work around this bug,
/// don't use labels that could be confused with a binary literal.
///
/// This behavior is platform-specific to x86 and x86-64.
///
/// See the explanation in [Rust By Example] for more details.
///
/// [LLVM bug]: https://bugs.llvm.org/show_bug.cgi?id=36144
/// [LLVM bug]: https://github.com/llvm/llvm-project/issues/99547
/// [Rust By Example]: https://doc.rust-lang.org/nightly/rust-by-example/unsafe/asm.html#labels
pub BINARY_ASM_LABELS,
Deny,