1; RUN: llc -O1 -o - %s | FileCheck %s 2 3; Check that dbg.value(undef) calls are not simply discarded. 4 5target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" 6target triple = "x86_64-unknown-linux-gnu" 7 8define void @foo() !dbg !7 { 9entry: 10 call void @llvm.dbg.value(metadata i32 42, metadata !11, metadata !DIExpression()), !dbg !13 11 call void (...) @bar(), !dbg !14 12 call void @llvm.dbg.value(metadata i32 undef, metadata !11, metadata !DIExpression()), !dbg !13 13 call void (...) @bar(), !dbg !15 14 ret void, !dbg !16 15} 16 17declare void @bar(...) 18 19; Function Attrs: nounwind readnone speculatable 20declare void @llvm.dbg.value(metadata, metadata, metadata) #0 21 22attributes #0 = { nounwind readnone speculatable } 23 24!llvm.dbg.cu = !{!0} 25!llvm.module.flags = !{!3, !4, !5} 26!llvm.ident = !{!6} 27 28!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 7.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2) 29!1 = !DIFile(filename: "test.c", directory: "/tmp") 30!2 = !{} 31!3 = !{i32 2, !"Dwarf Version", i32 4} 32!4 = !{i32 2, !"Debug Info Version", i32 3} 33!5 = !{i32 1, !"wchar_size", i32 4} 34!6 = !{!"clang version 7.0.0"} 35!7 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 3, type: !8, isLocal: false, isDefinition: true, scopeLine: 3, isOptimized: true, unit: !0, retainedNodes: !10) 36!8 = !DISubroutineType(types: !9) 37!9 = !{null} 38!10 = !{!11} 39!11 = !DILocalVariable(name: "x", scope: !7, file: !1, line: 4, type: !12) 40!12 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed) 41!13 = !DILocation(line: 4, column: 7, scope: !7) 42!14 = !DILocation(line: 5, column: 3, scope: !7) 43!15 = !DILocation(line: 7, column: 3, scope: !7) 44!16 = !DILocation(line: 8, column: 1, scope: !7) 45 46; Original C program: 47; void bar(); 48; 49; void foo() { 50; int x = 42; 51; bar(); 52; x = 23; 53; bar(); 54; } 55; 56; Then the dbg.value for the x = 23 setting has been replaced with dbg.value(undef) 57; in this ll file to provoke the wanted behavior in LiveDebugVariables. 58 59; Variable 'x' should thus be updated two times, first to 42 and then to undef. 60 61; CHECK-LABEL: foo: 62; CHECK: #DEBUG_VALUE: foo:x <- 42 63; CHECK: callq bar 64; CHECK: #DEBUG_VALUE: foo:x <- undef 65; CHECK: callq bar 66