From 78caecf8f30dbdbfcb6e0fda25edc72b3e4d04a5 Mon Sep 17 00:00:00 2001 From: Kyle Huey Date: Sat, 3 Aug 2024 21:04:19 -0700 Subject: Special case DUMMY_SP to emit line 0/column 0 locations on DWARF platforms. Line 0 has a special meaning in DWARF. From the version 5 spec: The compiler may emit the value 0 in cases where an instruction cannot be attributed to any source line. DUMMY_SP spans cannot be attributed to any line. However, because rustc internally stores line numbers starting at zero, lookup_debug_loc() adjusts every line number by one. Special casing DUMMY_SP to actually emit line 0 ensures rustc communicates to the debugger that there's no meaningful source code for this instruction, rather than telling the debugger to jump to line 1 randomly. --- compiler/rustc_codegen_llvm/src/debuginfo/mod.rs | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'compiler/rustc_codegen_llvm/src/debuginfo') diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs b/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs index b23e05182ca..3706d31e66e 100644 --- a/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs +++ b/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs @@ -20,7 +20,7 @@ use rustc_session::config::{self, DebugInfo}; use rustc_session::Session; use rustc_span::symbol::Symbol; use rustc_span::{ - BytePos, Pos, SourceFile, SourceFileAndLine, SourceFileHash, Span, StableSourceFileId, + BytePos, Pos, SourceFile, SourceFileAndLine, SourceFileHash, Span, StableSourceFileId, DUMMY_SP, }; use rustc_target::abi::Size; use smallvec::SmallVec; @@ -570,7 +570,12 @@ impl<'ll, 'tcx> DebugInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> { inlined_at: Option<&'ll DILocation>, span: Span, ) -> &'ll DILocation { - let DebugLoc { line, col, .. } = self.lookup_debug_loc(span.lo()); + let (line, col) = if span == DUMMY_SP && !self.sess().target.is_like_msvc { + (0, 0) + } else { + let DebugLoc { line, col, .. } = self.lookup_debug_loc(span.lo()); + (line, col) + }; unsafe { llvm::LLVMRustDIBuilderCreateDebugLocation(line, col, scope, inlined_at) } } -- cgit 1.4.1-3-g733a5