[PATCH] D81631: Fix undefined behavior in Dwarf.
David Blaikie via Phabricator via llvm-commits
llvm-commits at lists.llvm.org
Thu Jun 18 22:51:54 PDT 2020
dblaikie added a comment.
In D81631#2102518 <https://reviews.llvm.org/D81631#2102518>, @linzj wrote:
> I can't reproduce the bug with ubsan! Even in the latest version.
Memory sanitizer might be the better tool for this particular issue - if it's a read of an uninitialized value.
> But valgrind is able to reproduce it.
Hmm - I'm not having much luck with that myself:
$ cat test.ll
target datalayout = "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64"
target triple = "armv7-unknown-linux-android"
; Function Attrs: norecurse nounwind readnone
define hidden i32 @add(i32 %0, i32 %1) local_unnamed_addr #0 !dbg !9 {
call void @llvm.dbg.value(metadata i32 %0, metadata !14, metadata !DIExpression()), !dbg !16
call void @llvm.dbg.value(metadata i32 %1, metadata !15, metadata !DIExpression()), !dbg !16
%3 = add nsw i32 %1, %0, !dbg !17
ret i32 %3, !dbg !18
}
; Function Attrs: nounwind readnone speculatable willreturn
declare void @llvm.dbg.value(metadata, metadata, metadata) #1
attributes #0 = { norecurse nounwind readnone "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="none" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="generic" "target-features"="+armv7-a,+d32,+dsp,+fp64,+neon,+vfp2,+vfp2sp,+vfp3,+vfp3d16,+vfp3d16sp,+vfp3sp,-crypto,-fp-armv8,-fp-armv8d16,-fp-armv8d16sp,-fp-armv8sp,-fp16,-fp16fml,-fullfp16,-thumb-mode,-vfp4,-vfp4d16,-vfp4d16sp,-vfp4sp" "unsafe-fp-math"="false" "use-soft-float"="false" }
attributes #1 = { nounwind readnone speculatable willreturn }
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!3, !4, !5, !6, !7}
!llvm.ident = !{!8}
!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 11.0.0 (https://github.com/llvm/llvm-project.git 6dd738e2f0609f7d3313b574a1d471263d2d3ba1)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, splitDebugInlining: false, nameTableKind: None)
!1 = !DIFile(filename: "1.c", directory: "/tmp")
!2 = !{}
!3 = !{i32 7, !"Dwarf Version", i32 4}
!4 = !{i32 2, !"Debug Info Version", i32 3}
!5 = !{i32 1, !"wchar_size", i32 4}
!6 = !{i32 1, !"min_enum_size", i32 4}
!7 = !{i32 7, !"PIC Level", i32 2}
!8 = !{!"clang version 11.0.0 (https://github.com/llvm/llvm-project.git 6dd738e2f0609f7d3313b574a1d471263d2d3ba1)"}
!9 = distinct !DISubprogram(name: "add", scope: !1, file: !1, line: 1, type: !10, scopeLine: 1, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !13)
!10 = !DISubroutineType(types: !11)
!11 = !{!12, !12, !12}
!12 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
!13 = !{!14, !15}
!14 = !DILocalVariable(name: "a", arg: 1, scope: !9, file: !1, line: 1, type: !12)
!15 = !DILocalVariable(name: "b", arg: 2, scope: !9, file: !1, line: 1, type: !12)
!16 = !DILocation(line: 0, scope: !9)
!17 = !DILocation(line: 2, column: 12, scope: !9)
!18 = !DILocation(line: 2, column: 3, scope: !9)$ cat test.ll
target datalayout = "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64"
target triple = "armv7-unknown-linux-android"
; Function Attrs: norecurse nounwind readnone
define hidden i32 @add(i32 %0, i32 %1) local_unnamed_addr #0 !dbg !9 {
call void @llvm.dbg.value(metadata i32 %0, metadata !14, metadata !DIExpression()), !dbg !16
call void @llvm.dbg.value(metadata i32 %1, metadata !15, metadata !DIExpression()), !dbg !16
%3 = add nsw i32 %1, %0, !dbg !17
ret i32 %3, !dbg !18
}
; Function Attrs: nounwind readnone speculatable willreturn
declare void @llvm.dbg.value(metadata, metadata, metadata) #1
attributes #0 = { norecurse nounwind readnone "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="none" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="generic" "target-features"="+armv7-a,+d32,+dsp,+fp64,+neon,+vfp2,+vfp2sp,+vfp3,+vfp3d16,+vfp3d16sp,+vfp3sp,-crypto,-fp-armv8,-fp-armv8d16,-fp-armv8d16sp,-fp-armv8sp,-fp16,-fp16fml,-fullfp16,-thumb-mode,-vfp4,-vfp4d16,-vfp4d16sp,-vfp4sp" "unsafe-fp-math"="false" "use-soft-float"="false" }
attributes #1 = { nounwind readnone speculatable willreturn }
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!3, !4, !5, !6, !7}
!llvm.ident = !{!8}
!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 11.0.0 (https://github.com/llvm/llvm-project.git 6dd738e2f0609f7d3313b574a1d471263d2d3ba1)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, splitDebugInlining: false, nameTableKind: None)
!1 = !DIFile(filename: "1.c", directory: "/tmp")
!2 = !{}
!3 = !{i32 7, !"Dwarf Version", i32 4}
!4 = !{i32 2, !"Debug Info Version", i32 3}
!5 = !{i32 1, !"wchar_size", i32 4}
!6 = !{i32 1, !"min_enum_size", i32 4}
!7 = !{i32 7, !"PIC Level", i32 2}
!8 = !{!"clang version 11.0.0 (https://github.com/llvm/llvm-project.git 6dd738e2f0609f7d3313b574a1d471263d2d3ba1)"}
!9 = distinct !DISubprogram(name: "add", scope: !1, file: !1, line: 1, type: !10, scopeLine: 1, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !13)
!10 = !DISubroutineType(types: !11)
!11 = !{!12, !12, !12}
!12 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
!13 = !{!14, !15}
!14 = !DILocalVariable(name: "a", arg: 1, scope: !9, file: !1, line: 1, type: !12)
!15 = !DILocalVariable(name: "b", arg: 2, scope: !9, file: !1, line: 1, type: !12)
!16 = !DILocation(line: 0, scope: !9)
!17 = !DILocation(line: 2, column: 12, scope: !9)
!18 = !DILocation(line: 2, column: 3, scope: !9)
Any ideas?
Repository:
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CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D81631/new/
https://reviews.llvm.org/D81631
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