Index: llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp =================================================================== --- llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp +++ llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp @@ -2039,7 +2039,10 @@ unsigned LastAsmLine = Asm->OutStreamer->getContext().getCurrentDwarfLoc().getLine(); - if (DL == PrevInstLoc) { + bool PrevInstInSameSection = (!PrevInstBB || + PrevInstBB->getSectionIDNum() == MI->getParent()->getSectionIDNum()); + + if (DL == PrevInstLoc && PrevInstInSameSection) { // If we have an ongoing unspecified location, nothing to do here. if (!DL) return; Index: llvm/test/DebugInfo/debuglineinfo-at-section-boundary.ll =================================================================== --- /dev/null +++ llvm/test/DebugInfo/debuglineinfo-at-section-boundary.ll @@ -0,0 +1,45 @@ +; RUN: llc -filetype=asm -asm-verbose=0 --basic-block-sections=all < %s | FileCheck %s +; +; Verify that AsmPrinter does not optimize debug line directives +; across two distinct sections. Such optimization will lead +; to incorrect debug line number if the memory layout of those +; sections does not strictly mirror the order in the Asm file. +; +; int G; +; void func(int x) { +; if (x) G=0; +; } +; +; Reduced from the above example, the IR has been modified so that +; the store and return instructions have the same DebugLoc; in this +; context, we should see 2 different directives for line #4 +; +; CHECK-COUNT-2: .loc 0 4 1 + +define void @func(i1 %0) !dbg !8 { + br i1 %0, label %3, label %2 + +2: ; preds = %1 + store i32 0, ptr null, align 4, !dbg !12 + br label %3 + +3: ; preds = %2, %1 + ret void, !dbg !12 +} + +!llvm.dbg.cu = !{!0} +!llvm.module.flags = !{!6, !7} + +!0 = distinct !DICompileUnit(language: DW_LANG_C11, file: !1, producer: "clang version 16.0.2", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, globals: !2, splitDebugInlining: false, nameTableKind: None) +!1 = !DIFile(filename: "test.c", directory: "/tmp", checksumkind: CSK_MD5, checksum: "fd2935e6157b382ad81da17a61f24bb1") +!2 = !{!3} +!3 = !DIGlobalVariableExpression(var: !4, expr: !DIExpression()) +!4 = distinct !DIGlobalVariable(name: "G", scope: !0, file: !1, line: 1, type: !5, isLocal: false, isDefinition: true) +!5 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed) +!6 = !{i32 7, !"Dwarf Version", i32 5} +!7 = !{i32 2, !"Debug Info Version", i32 3} +!8 = distinct !DISubprogram(name: "func", scope: !1, file: !1, line: 2, type: !9, scopeLine: 2, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !11) +!9 = !DISubroutineType(types: !10) +!10 = !{null} +!11 = !{} +!12 = !DILocation(line: 4, column: 1, scope: !8)