[llvm] r340583 - DebugInfo: Improve debug location merging
Vitaly Buka via llvm-commits
llvm-commits at lists.llvm.org
Mon Aug 27 17:18:18 PDT 2018
I can't reproduce on Linux.
+Reid Kleckner <rnk at google.com>
On Mon, Aug 27, 2018 at 5:12 PM David Blaikie <dblaikie at gmail.com> wrote:
> Yeah, I'm totally open to some ideas on investigating that - can you
> reproduce this? Does it reproduce not on windows? I'd love some help!
>
> On Mon, Aug 27, 2018 at 5:09 PM Vitaly Buka <vitalybuka at google.com> wrote:
>
>> This revision breaks windows bot
>>
>> http://lab.llvm.org:8011/builders/sanitizer-windows/builds/33862/steps/run%20check-sanitizer/logs/stdio
>>
>> FAILED: projects/compiler-rt/lib/sanitizer_common/tests/SANITIZER_TEST_OBJECTS.sanitizer_stacktrace_printer_test.cc.i386.o
>> cmd.exe /C "cd /D C:\b\slave\sanitizer-windows\build\projects\compiler-rt\lib\sanitizer_common\tests && C:\b\slave\sanitizer-windows\build\.\bin\clang.exe -DWIN32 -D_WINDOWS -Wno-unknown-warning-option -fms-compatibility-version=19.00.24215.1 -D_HAS_EXCEPTIONS=0 -Wno-undefined-inline -DGTEST_NO_LLVM_RAW_OSTREAM=1 -DGTEST_HAS_RTTI=0 -IC:/b/slave/sanitizer-windows/llvm/utils/unittest/googletest/include -IC:/b/slave/sanitizer-windows/llvm/utils/unittest/googletest -DGTEST_HAS_SEH=0 -Wno-deprecated-declarations -IC:/b/slave/sanitizer-windows/llvm/projects/compiler-rt/include -IC:/b/slave/sanitizer-windows/llvm/projects/compiler-rt/lib -IC:/b/slave/sanitizer-windows/llvm/projects/compiler-rt/lib/sanitizer_common -fno-rtti -O2 -Werror=sign-compare -Wno-non-virtual-dtor -Wno-gnu-zero-variadic-macro-arguments -fno-exceptions -DGTEST_HAS_SEH=0 -gline-tables-only -gcodeview -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -c -o SANITIZER_TEST_OBJECTS.sanitizer_stacktrace_printer_test.cc.i386.o C:/b/slave/sanitizer-windows/llvm/projects/compiler-rt/lib/sanitizer_common/tests/sanitizer_stacktrace_printer_test.cc"
>> Assertion failed: Result >= 0 && "negative label difference requested", file C:\b\slave\sanitizer-windows\llvm\lib\MC\MCCodeView.cpp, line 449
>>
>> Wrote crash dump file "C:\Users\buildbot\AppData\Local\Temp\clang.exe-30d2bf.dmp"
>>
>> LLVMSymbolizer: error reading file: PDB Error: Unable to load PDB. Make sure the file exists and is readable. Calling loadDataForExe
>>
>>
>>
>> #0 0x021cf367 (C:\b\slave\sanitizer-windows\build\bin\clang.exe+0x119f367)
>>
>> #1 0x72ec91d2 (C:\windows\SYSTEM32\ucrtbase.DLL+0x891d2)
>>
>> #2 0x72eca7e1 (C:\windows\SYSTEM32\ucrtbase.DLL+0x8a7e1)
>>
>> #3 0x72ec9c1e (C:\windows\SYSTEM32\ucrtbase.DLL+0x89c1e)
>>
>> #4 0x72eca8e6 (C:\windows\SYSTEM32\ucrtbase.DLL+0x8a8e6)
>>
>> #5 0x0201cad9 (C:\b\slave\sanitizer-windows\build\bin\clang.exe+0xfecad9)
>>
>> #6 0x0201e219 (C:\b\slave\sanitizer-windows\build\bin\clang.exe+0xfee219)
>>
>> #7 0x02010b71 (C:\b\slave\sanitizer-windows\build\bin\clang.exe+0xfe0b71)
>>
>> #8 0x020109f6 (C:\b\slave\sanitizer-windows\build\bin\clang.exe+0xfe09f6)
>>
>> #9 0x0201049d (C:\b\slave\sanitizer-windows\build\bin\clang.exe+0xfe049d)
>>
>> #10 0x01fee676 (C:\b\slave\sanitizer-windows\build\bin\clang.exe+0xfbe676)
>>
>> #11 0x021aa8b3 (C:\b\slave\sanitizer-windows\build\bin\clang.exe+0x117a8b3)
>>
>> #12 0x0200cd47 (C:\b\slave\sanitizer-windows\build\bin\clang.exe+0xfdcd47)
>>
>> clang: error: clang frontend command failed due to signal (use -v to see invocation)
>>
>> clang version 8.0.0 (trunk 340583)
>>
>> Target: i686-pc-windows-msvc
>>
>> Thread model: posix
>>
>> InstalledDir: C:\b\slave\sanitizer-windows\build\.\bin
>>
>> clang: note: diagnostic msg: PLEASE submit a bug report to https://bugs.llvm.org/ and include the crash backtrace, preprocessed source, and associated run script.
>>
>> clang: note: diagnostic msg:
>>
>> ********************
>>
>>
>> On Thu, Aug 23, 2018 at 3:36 PM David Blaikie via llvm-commits <
>> llvm-commits at lists.llvm.org> wrote:
>>
>>> Author: dblaikie
>>> Date: Thu Aug 23 15:35:58 2018
>>> New Revision: 340583
>>>
>>> URL: http://llvm.org/viewvc/llvm-project?rev=340583&view=rev
>>> Log:
>>> DebugInfo: Improve debug location merging
>>>
>>> Fix a set of related bugs:
>>>
>>> * Considering two locations as equivalent when their lines are the same
>>> but their scopes are different causes erroneous debug info that
>>> attributes a commoned call to be attributed to one of the two calls it
>>> was commoned from.
>>>
>>> * The previous code to compute a new location's scope was inaccurate and
>>> would use the inlinedAt that was the /parent/ of the inlinedAt that is
>>> the nearest common one, and also used that parent scope instead of the
>>> nearest common scope.
>>>
>>> * Not generating new locations generally seemed like a lower quality
>>> choice
>>>
>>> There was some risk that generating more new locations could hurt object
>>> size by making more fine grained line table entries, but it looks like
>>> that was offset by the decrease in line table (& address & ranges) size
>>> caused by more accurately computing the scope - which likely lead to
>>> fewer range entries (more contiguous ranges) & reduced size that way.
>>>
>>> All up with these changes I saw minor reductions (-1.21%, -1.77%) in
>>> .rela.debug_ranges and .rela.debug_addr (in a fission, compressed debug
>>> info build) as well as other minor size changes (generally reductinos)
>>> across the board (-1.32% debug_info.dwo, -1.28% debug_loc.dwo). Measured
>>> in an optimized (-O2) build of the clang binary.
>>>
>>> If you are investigating a size regression in an optimized debug builds,
>>> this is certainly a patch to look into - and I'd be happy to look into
>>> any major regressions found & see what we can do to address them.
>>>
>>> Added:
>>> llvm/trunk/test/DebugInfo/X86/merge_inlined_loc.ll
>>> Modified:
>>> llvm/trunk/include/llvm/IR/DebugInfoMetadata.h
>>> llvm/trunk/lib/IR/DebugInfo.cpp
>>> llvm/trunk/lib/IR/DebugInfoMetadata.cpp
>>> llvm/trunk/test/DebugInfo/COFF/local-variables.ll
>>>
>>> Modified: llvm/trunk/include/llvm/IR/DebugInfoMetadata.h
>>> URL:
>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/IR/DebugInfoMetadata.h?rev=340583&r1=340582&r2=340583&view=diff
>>>
>>> ==============================================================================
>>> --- llvm/trunk/include/llvm/IR/DebugInfoMetadata.h (original)
>>> +++ llvm/trunk/include/llvm/IR/DebugInfoMetadata.h Thu Aug 23 15:35:58
>>> 2018
>>> @@ -1479,19 +1479,6 @@ public:
>>> return getScope();
>>> }
>>>
>>> - /// Check whether this can be discriminated from another location.
>>> - ///
>>> - /// Check \c this can be discriminated from \c RHS in a linetable
>>> entry.
>>> - /// Scope and inlined-at chains are not recorded in the linetable, so
>>> they
>>> - /// cannot be used to distinguish basic blocks.
>>> - bool canDiscriminate(const DILocation &RHS) const {
>>> - return getLine() != RHS.getLine() ||
>>> - getColumn() != RHS.getColumn() ||
>>> - getDiscriminator() != RHS.getDiscriminator() ||
>>> - getFilename() != RHS.getFilename() ||
>>> - getDirectory() != RHS.getDirectory();
>>> - }
>>> -
>>> /// Get the DWARF discriminator.
>>> ///
>>> /// DWARF discriminators distinguish identical file locations between
>>> @@ -1539,8 +1526,6 @@ public:
>>> /// discriminator.
>>> inline const DILocation *cloneWithDuplicationFactor(unsigned DF)
>>> const;
>>>
>>> - enum { NoGeneratedLocation = false, WithGeneratedLocation = true };
>>> -
>>> /// When two instructions are combined into a single instruction we
>>> also
>>> /// need to combine the original locations into a single location.
>>> ///
>>> @@ -1555,9 +1540,8 @@ public:
>>> ///
>>> /// \p GenerateLocation: Whether the merged location can be generated
>>> when
>>> /// \p LocA and \p LocB differ.
>>> - static const DILocation *
>>> - getMergedLocation(const DILocation *LocA, const DILocation *LocB,
>>> - bool GenerateLocation = NoGeneratedLocation);
>>> + static const DILocation *getMergedLocation(const DILocation *LocA,
>>> + const DILocation *LocB);
>>>
>>> /// Returns the base discriminator for a given encoded discriminator
>>> \p D.
>>> static unsigned getBaseDiscriminatorFromDiscriminator(unsigned D) {
>>>
>>> Modified: llvm/trunk/lib/IR/DebugInfo.cpp
>>> URL:
>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/DebugInfo.cpp?rev=340583&r1=340582&r2=340583&view=diff
>>>
>>> ==============================================================================
>>> --- llvm/trunk/lib/IR/DebugInfo.cpp (original)
>>> +++ llvm/trunk/lib/IR/DebugInfo.cpp Thu Aug 23 15:35:58 2018
>>> @@ -690,8 +690,7 @@ unsigned llvm::getDebugMetadataVersionFr
>>>
>>> void Instruction::applyMergedLocation(const DILocation *LocA,
>>> const DILocation *LocB) {
>>> - setDebugLoc(DILocation::getMergedLocation(LocA, LocB,
>>> -
>>> DILocation::WithGeneratedLocation));
>>> + setDebugLoc(DILocation::getMergedLocation(LocA, LocB));
>>> }
>>>
>>>
>>> //===----------------------------------------------------------------------===//
>>>
>>> Modified: llvm/trunk/lib/IR/DebugInfoMetadata.cpp
>>> URL:
>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/DebugInfoMetadata.cpp?rev=340583&r1=340582&r2=340583&view=diff
>>>
>>> ==============================================================================
>>> --- llvm/trunk/lib/IR/DebugInfoMetadata.cpp (original)
>>> +++ llvm/trunk/lib/IR/DebugInfoMetadata.cpp Thu Aug 23 15:35:58 2018
>>> @@ -14,7 +14,7 @@
>>> #include "llvm/IR/DebugInfoMetadata.h"
>>> #include "LLVMContextImpl.h"
>>> #include "MetadataImpl.h"
>>> -#include "llvm/ADT/SmallPtrSet.h"
>>> +#include "llvm/ADT/SmallSet.h"
>>> #include "llvm/ADT/StringSwitch.h"
>>> #include "llvm/IR/DIBuilder.h"
>>> #include "llvm/IR/Function.h"
>>> @@ -69,28 +69,40 @@ DILocation *DILocation::getImpl(LLVMCont
>>> }
>>>
>>> const DILocation *DILocation::getMergedLocation(const DILocation *LocA,
>>> - const DILocation *LocB,
>>> - bool GenerateLocation) {
>>> + const DILocation *LocB)
>>> {
>>> if (!LocA || !LocB)
>>> return nullptr;
>>>
>>> - if (LocA == LocB || !LocA->canDiscriminate(*LocB))
>>> + if (LocA == LocB)
>>> return LocA;
>>>
>>> - if (!GenerateLocation)
>>> - return nullptr;
>>> -
>>> SmallPtrSet<DILocation *, 5> InlinedLocationsA;
>>> for (DILocation *L = LocA->getInlinedAt(); L; L = L->getInlinedAt())
>>> InlinedLocationsA.insert(L);
>>> + SmallSet<std::pair<DIScope *, DILocation *>, 5> Locations;
>>> + DIScope *S = LocA->getScope();
>>> + DILocation *L = LocA->getInlinedAt();
>>> + while (S) {
>>> + Locations.insert(std::make_pair(S, L));
>>> + S = S->getScope().resolve();
>>> + if (!S && L) {
>>> + S = L->getScope();
>>> + L = L->getInlinedAt();
>>> + }
>>> + }
>>> const DILocation *Result = LocB;
>>> - for (DILocation *L = LocB->getInlinedAt(); L; L = L->getInlinedAt()) {
>>> - Result = L;
>>> - if (InlinedLocationsA.count(L))
>>> + S = LocB->getScope();
>>> + L = LocB->getInlinedAt();
>>> + while (S) {
>>> + if (Locations.count(std::make_pair(S, L)))
>>> break;
>>> + S = S->getScope().resolve();
>>> + if (!S && L) {
>>> + S = L->getScope();
>>> + L = L->getInlinedAt();
>>> + }
>>> }
>>> - return DILocation::get(Result->getContext(), 0, 0, Result->getScope(),
>>> - Result->getInlinedAt());
>>> + return DILocation::get(Result->getContext(), 0, 0, S, L);
>>> }
>>>
>>> DINode::DIFlags DINode::getFlag(StringRef Flag) {
>>>
>>> Modified: llvm/trunk/test/DebugInfo/COFF/local-variables.ll
>>> URL:
>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/COFF/local-variables.ll?rev=340583&r1=340582&r2=340583&view=diff
>>>
>>> ==============================================================================
>>> --- llvm/trunk/test/DebugInfo/COFF/local-variables.ll (original)
>>> +++ llvm/trunk/test/DebugInfo/COFF/local-variables.ll Thu Aug 23
>>> 15:35:58 2018
>>> @@ -60,7 +60,7 @@
>>> ; ASM: leaq 36(%rsp), %rcx
>>> ; ASM: [[else_end:\.Ltmp.*]]:
>>> ; ASM: .LBB0_3: # %if.end
>>> -; ASM: .cv_loc 0 1 17 1 # t.cpp:17:1
>>> +; ASM: .cv_loc 0 1 0 0 # t.cpp:0:0
>>> ; ASM: callq capture
>>> ; ASM: nop
>>> ; ASM: addq $56, %rsp
>>>
>>> Added: llvm/trunk/test/DebugInfo/X86/merge_inlined_loc.ll
>>> URL:
>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/X86/merge_inlined_loc.ll?rev=340583&view=auto
>>>
>>> ==============================================================================
>>> --- llvm/trunk/test/DebugInfo/X86/merge_inlined_loc.ll (added)
>>> +++ llvm/trunk/test/DebugInfo/X86/merge_inlined_loc.ll Thu Aug 23
>>> 15:35:58 2018
>>> @@ -0,0 +1,100 @@
>>> +; RUN: llc %s -mtriple=x86_64-unknown-unknown -o - | FileCheck %s
>>> +
>>> +; Generated with "clang -g -c -emit-llvm -S -O3"
>>> +
>>> +; This will test several features of merging debug locations.
>>> Importantly,
>>> +; locations with the same source line but different scopes should be
>>> merged to
>>> +; a line zero location at the nearest common scope and inlining. The
>>> location
>>> +; of the single call to "common" (the two calls are collapsed together
>>> by
>>> +; BranchFolding) should be attributed to line zero inside the wrapper2
>>> inlined
>>> +; scope within f1.
>>> +
>>> +; void common();
>>> +; inline void wrapper() { common(); }
>>> +; extern bool b;
>>> +; void sink();
>>> +; inline void wrapper2() {
>>> +; if (b) {
>>> +; sink();
>>> +; wrapper();
>>> +; } else
>>> +; wrapper();
>>> +; }
>>> +; void f1() { wrapper2(); }
>>> +
>>> +; Ensure there is only one inlined_subroutine (for wrapper2, none for
>>> wrapper)
>>> +; & that its address range includes the call to 'common'.
>>> +
>>> +; CHECK: jmp _Z6commonv
>>> +; CHECK-NEXT: [[LABEL:.*]]:
>>> +
>>> +; CHECK: .section .debug_info
>>> +; CHECK: DW_TAG_subprogram
>>> +; CHECK: DW_TAG_subprogram
>>> +; CHECK-NOT: {{DW_TAG\|End Of Children}}
>>> +; CHECK: DW_TAG_inlined_subroutine
>>> +; CHECK-NOT: {{DW_TAG\|End Of Children}}
>>> +; CHECK: [[LABEL]]-{{.*}} DW_AT_high_pc
>>> +; CHECK-NOT: DW_TAG
>>> +
>>> +
>>> +
>>> + at b = external dso_local local_unnamed_addr global i8, align 1
>>> +
>>> +; Function Attrs: uwtable
>>> +define dso_local void @_Z2f1v() local_unnamed_addr !dbg !7 {
>>> +entry:
>>> + %0 = load i8, i8* @b, align 1, !dbg !10, !tbaa !14, !range !18
>>> + %tobool.i = icmp eq i8 %0, 0, !dbg !10
>>> + br i1 %tobool.i, label %if.else.i, label %if.then.i, !dbg !19
>>> +
>>> +if.then.i: ; preds = %entry
>>> + tail call void @_Z4sinkv(), !dbg !20
>>> + tail call void @_Z6commonv(), !dbg !22
>>> + br label %_Z8wrapper2v.exit, !dbg !25
>>> +
>>> +if.else.i: ; preds = %entry
>>> + tail call void @_Z6commonv(), !dbg !26
>>> + br label %_Z8wrapper2v.exit
>>> +
>>> +_Z8wrapper2v.exit: ; preds = %if.then.i,
>>> %if.else.i
>>> + ret void, !dbg !28
>>> +}
>>> +
>>> +declare dso_local void @_Z4sinkv() local_unnamed_addr
>>> +
>>> +declare dso_local void @_Z6commonv() local_unnamed_addr
>>> +
>>> +!llvm.dbg.cu = !{!0}
>>> +!llvm.module.flags = !{!3, !4, !5}
>>> +!llvm.ident = !{!6}
>>> +
>>> +!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1,
>>> producer: "clang version 8.0.0 (trunk 340559) (llvm/trunk 340572)",
>>> isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2,
>>> nameTableKind: None)
>>> +!1 = !DIFile(filename: "merge_loc.cpp", directory:
>>> "/usr/local/google/home/blaikie/dev/scratch")
>>> +!2 = !{}
>>> +!3 = !{i32 2, !"Dwarf Version", i32 4}
>>> +!4 = !{i32 2, !"Debug Info Version", i32 3}
>>> +!5 = !{i32 1, !"wchar_size", i32 4}
>>> +!6 = !{!"clang version 8.0.0 (trunk 340559) (llvm/trunk 340572)"}
>>> +!7 = distinct !DISubprogram(name: "f1", linkageName: "_Z2f1v", scope:
>>> !1, file: !1, line: 12, type: !8, isLocal: false, isDefinition: true,
>>> scopeLine: 12, flags: DIFlagPrototyped, isOptimized: true, unit: !0,
>>> retainedNodes: !2)
>>> +!8 = !DISubroutineType(types: !9)
>>> +!9 = !{null}
>>> +!10 = !DILocation(line: 6, column: 7, scope: !11, inlinedAt: !13)
>>> +!11 = distinct !DILexicalBlock(scope: !12, file: !1, line: 6, column: 7)
>>> +!12 = distinct !DISubprogram(name: "wrapper2", linkageName:
>>> "_Z8wrapper2v", scope: !1, file: !1, line: 5, type: !8, isLocal: false,
>>> isDefinition: true, scopeLine: 5, flags: DIFlagPrototyped, isOptimized:
>>> true, unit: !0, retainedNodes: !2)
>>> +!13 = distinct !DILocation(line: 13, column: 3, scope: !7)
>>> +!14 = !{!15, !15, i64 0}
>>> +!15 = !{!"bool", !16, i64 0}
>>> +!16 = !{!"omnipotent char", !17, i64 0}
>>> +!17 = !{!"Simple C++ TBAA"}
>>> +!18 = !{i8 0, i8 2}
>>> +!19 = !DILocation(line: 6, column: 7, scope: !12, inlinedAt: !13)
>>> +!20 = !DILocation(line: 7, column: 5, scope: !21, inlinedAt: !13)
>>> +!21 = distinct !DILexicalBlock(scope: !11, file: !1, line: 6, column:
>>> 10)
>>> +!22 = !DILocation(line: 2, column: 25, scope: !23, inlinedAt: !24)
>>> +!23 = distinct !DISubprogram(name: "wrapper", linkageName:
>>> "_Z7wrapperv", scope: !1, file: !1, line: 2, type: !8, isLocal: false,
>>> isDefinition: true, scopeLine: 2, flags: DIFlagPrototyped, isOptimized:
>>> true, unit: !0, retainedNodes: !2)
>>> +!24 = distinct !DILocation(line: 8, column: 5, scope: !21, inlinedAt:
>>> !13)
>>> +!25 = !DILocation(line: 9, column: 3, scope: !21, inlinedAt: !13)
>>> +!26 = !DILocation(line: 2, column: 25, scope: !23, inlinedAt: !27)
>>> +!27 = distinct !DILocation(line: 10, column: 5, scope: !11, inlinedAt:
>>> !13)
>>> +!28 = !DILocation(line: 14, column: 1, scope: !7)
>>>
>>>
>>> _______________________________________________
>>> llvm-commits mailing list
>>> llvm-commits at lists.llvm.org
>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits
>>>
>>
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