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| author | Folkert de Vries <folkert@folkertdev.nl> | 2025-09-19 21:53:06 +0200 |
|---|---|---|
| committer | Folkert de Vries <folkert@folkertdev.nl> | 2025-09-19 21:53:06 +0200 |
| commit | b27942853efdb2fde2b6f73023c38ebfec3fcb8f (patch) | |
| tree | 7b4003c16d829ed7c249a002ffc31de4b58b471f | |
| parent | 8a1b39995e5b630c5872f5de5079f1f569bd5ac2 (diff) | |
| download | rust-b27942853efdb2fde2b6f73023c38ebfec3fcb8f.tar.gz rust-b27942853efdb2fde2b6f73023c38ebfec3fcb8f.zip | |
naked_asm: emit a label starting with `func_end`
The `cargo asm` tool pattern matches on such labels to figure out where functions end: normal functions generated by LLVM always do have such a label. We don't guarantee that naked functions emit such a label, but having `cargo asm` work is convenient
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/mir/naked_asm.rs | 6 | ||||
| -rw-r--r-- | tests/assembly-llvm/naked-functions/wasm32.rs | 1 |
2 files changed, 7 insertions, 0 deletions
diff --git a/compiler/rustc_codegen_ssa/src/mir/naked_asm.rs b/compiler/rustc_codegen_ssa/src/mir/naked_asm.rs index 31784cabf4a..e7239ebfecf 100644 --- a/compiler/rustc_codegen_ssa/src/mir/naked_asm.rs +++ b/compiler/rustc_codegen_ssa/src/mir/naked_asm.rs @@ -228,6 +228,9 @@ fn prefix_and_suffix<'tcx>( writeln!(begin, "{asm_name}:").unwrap(); writeln!(end).unwrap(); + // emit a label starting with `func_end` for `cargo asm` and other tooling that might + // pattern match on assembly generated by LLVM. + writeln!(end, ".Lfunc_end_{asm_name}:").unwrap(); writeln!(end, ".size {asm_name}, . - {asm_name}").unwrap(); writeln!(end, ".popsection").unwrap(); if !arch_suffix.is_empty() { @@ -246,6 +249,7 @@ fn prefix_and_suffix<'tcx>( writeln!(begin, "{asm_name}:").unwrap(); writeln!(end).unwrap(); + writeln!(end, ".Lfunc_end_{asm_name}:").unwrap(); writeln!(end, ".popsection").unwrap(); if !arch_suffix.is_empty() { writeln!(end, "{}", arch_suffix).unwrap(); @@ -263,6 +267,7 @@ fn prefix_and_suffix<'tcx>( writeln!(begin, "{asm_name}:").unwrap(); writeln!(end).unwrap(); + writeln!(end, ".Lfunc_end_{asm_name}:").unwrap(); writeln!(end, ".popsection").unwrap(); if !arch_suffix.is_empty() { writeln!(end, "{}", arch_suffix).unwrap(); @@ -287,6 +292,7 @@ fn prefix_and_suffix<'tcx>( writeln!(end).unwrap(); // .size is ignored for function symbols, so we can skip it writeln!(end, "end_function").unwrap(); + writeln!(end, ".Lfunc_end_{asm_name}:").unwrap(); } BinaryFormat::Xcoff => { // the LLVM XCOFFAsmParser is extremely incomplete and does not implement many of the diff --git a/tests/assembly-llvm/naked-functions/wasm32.rs b/tests/assembly-llvm/naked-functions/wasm32.rs index 77547e82041..4bf04dd3923 100644 --- a/tests/assembly-llvm/naked-functions/wasm32.rs +++ b/tests/assembly-llvm/naked-functions/wasm32.rs @@ -21,6 +21,7 @@ use minicore::*; // CHECK: .functype nop () -> () // CHECK-NOT: .size // CHECK: end_function +// CHECK-LABEL: .Lfunc_end_nop: #[no_mangle] #[unsafe(naked)] extern "C" fn nop() { |