[llvm] r208506 - DebugInfo: Include lexical scopes in inlined subroutines.
David Blaikie
dblaikie at gmail.com
Mon May 12 16:55:37 PDT 2014
On Mon, May 12, 2014 at 4:51 PM, Alexey Samsonov <samsonov at google.com> wrote:
> Looks like this change breaks debug info under certain conditions. Here's a
> reproducer (sorry, but I wasn't able to quickly generate one without gtest):
>
> $ cat tmp/dbginfo/inl.cc
> #include "gtest/gtest.h"
> #include <stdio.h>
>
> void test(char x) {
> if (x)
> printf("good\n");
> }
>
> TEST(Foo, foo) {
> char *x = new char[8];
> fprintf(stderr, "x: %p\n", x);
> test(x[1]);
> }
>
> $ ./bin/clang++ -std=c++11 -O2 -gline-tables-only -D__STDC_LIMIT_MACROS
> -D__STDC_CONSTANT_MACROS -I /llvm_build/include -I
> /llvm/utils/unittest/googletest/include -I /llvm/include
> /llvm_build/lib/libgtest_main.a llvm_build/lib/libgtest.a
> /llvm_build/lib/libLLVMSupport.a -lcurses -lpthread -ldl tmp/dbginfo/inl.cc
>
> invocation of test() gets inlined in Foo_foo_Test::TestBody(). However,
> there is no sign of DW_TAG_inlined_subroutine in the debug info:
>
> $ readelf -wi a.out
> <...>
> <1><46>: Abbrev Number: 3 (DW_TAG_subprogram)
> <47> DW_AT_name : (indirect string, offset: 0x83): TestBody
> <4b> DW_AT_decl_file : 2
> <4c> DW_AT_decl_line : 9
> <4d> DW_AT_external : 1
> <4d> DW_AT_accessibility: 1 (public)
> <4e> DW_AT_low_pc : 0x457b50
> <56> DW_AT_high_pc : 0x37
> <5a> DW_AT_frame_base : 1 byte block: 57 (DW_OP_reg7 (rsp))
> <5c> Unknown AT value: 3fe7: 1
> <1><5c>: Abbrev Number: 4 (DW_TAG_subprogram)
> <5d> DW_AT_name : (indirect string, offset: 0x8c): Setup
> <...>
>
> This happens both for "-g" and for "-gline-tables-only". Any idea why this
> might happen?
Nope, not off-hand. Do you have a preprocessed source file that
demonstrates the issue?
- David
>
> On Sun, May 11, 2014 at 11:12 AM, David Blaikie <dblaikie at gmail.com> wrote:
>>
>> Author: dblaikie
>> Date: Sun May 11 13:12:17 2014
>> New Revision: 208506
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=208506&view=rev
>> Log:
>> DebugInfo: Include lexical scopes in inlined subroutines.
>>
>> Added:
>> llvm/trunk/test/DebugInfo/inline-scopes.ll
>> Modified:
>> llvm/trunk/include/llvm/ADT/STLExtras.h
>> llvm/trunk/include/llvm/CodeGen/LexicalScopes.h
>> llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
>> llvm/trunk/lib/CodeGen/LexicalScopes.cpp
>>
>> Modified: llvm/trunk/include/llvm/ADT/STLExtras.h
>> URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ADT/STLExtras.h?rev=208506&r1=208505&r2=208506&view=diff
>>
>> ==============================================================================
>> --- llvm/trunk/include/llvm/ADT/STLExtras.h (original)
>> +++ llvm/trunk/include/llvm/ADT/STLExtras.h Sun May 11 13:12:17 2014
>> @@ -530,6 +530,13 @@ make_unique(size_t n) {
>>
>> #endif
>>
>> +template<typename First, typename Second>
>> +struct pair_hash {
>> + size_t operator()(const std::pair<First, Second> &P) const {
>> + return std::hash<First>()(P.first) * 31 +
>> std::hash<Second>()(P.second);
>> + }
>> +};
>> +
>> } // End llvm namespace
>>
>> #endif
>>
>> Modified: llvm/trunk/include/llvm/CodeGen/LexicalScopes.h
>> URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/LexicalScopes.h?rev=208506&r1=208505&r2=208506&view=diff
>>
>> ==============================================================================
>> --- llvm/trunk/include/llvm/CodeGen/LexicalScopes.h (original)
>> +++ llvm/trunk/include/llvm/CodeGen/LexicalScopes.h Sun May 11 13:12:17
>> 2014
>> @@ -21,6 +21,7 @@
>> #include "llvm/ADT/DenseMap.h"
>> #include "llvm/ADT/SmallPtrSet.h"
>> #include "llvm/ADT/SmallVector.h"
>> +#include "llvm/ADT/STLExtras.h"
>> #include "llvm/IR/DebugLoc.h"
>> #include "llvm/IR/Metadata.h"
>> #include "llvm/IR/ValueHandle.h"
>> @@ -185,9 +186,7 @@ public:
>>
>> /// findInlinedScope - Find an inlined scope for the given DebugLoc or
>> return
>> /// NULL.
>> - LexicalScope *findInlinedScope(DebugLoc DL) {
>> - return InlinedLexicalScopeMap.lookup(DL);
>> - }
>> + LexicalScope *findInlinedScope(DebugLoc DL);
>>
>> /// findLexicalScope - Find regular lexical scope or return null.
>> LexicalScope *findLexicalScope(const MDNode *N) {
>> @@ -230,7 +229,9 @@ private:
>>
>> /// InlinedLexicalScopeMap - Tracks inlined function scopes in current
>> /// function.
>> - DenseMap<DebugLoc, LexicalScope *> InlinedLexicalScopeMap;
>> + std::unordered_map<std::pair<const MDNode *, const MDNode *>,
>> LexicalScope,
>> + pair_hash<const MDNode *, const MDNode *>>
>> + InlinedLexicalScopeMap;
>>
>> /// AbstractScopeMap - These scopes are not included LexicalScopeMap.
>> // Use an unordered_map to ensure value pointer validity over
>> insertion.
>>
>> Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
>> URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp?rev=208506&r1=208505&r2=208506&view=diff
>>
>> ==============================================================================
>> --- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp (original)
>> +++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp Sun May 11 13:12:17
>> 2014
>> @@ -621,7 +621,7 @@ std::unique_ptr<DIE> DwarfDebug::constru
>> // avoid creating un-used children then removing them later when we
>> find out
>> // the scope DIE is null.
>> std::unique_ptr<DIE> ScopeDIE;
>> - if (Scope->getInlinedAt()) {
>> + if (DS.getContext() && DS.isSubprogram()) {
>> ScopeDIE = constructInlinedScopeDIE(TheCU, Scope);
>> if (!ScopeDIE)
>> return nullptr;
>> @@ -1212,10 +1212,12 @@ DwarfDebug::collectVariableInfo(SmallPtr
>> if (DV.getTag() == dwarf::DW_TAG_arg_variable &&
>> DISubprogram(DV.getContext()).describes(CurFn->getFunction()))
>> Scope = LScopes.getCurrentFunctionScope();
>> - else if (MDNode *IA = DV.getInlinedAt())
>> - Scope = LScopes.findInlinedScope(DebugLoc::getFromDILocation(IA));
>> - else
>> - Scope = LScopes.findLexicalScope(cast<MDNode>(DV->getOperand(1)));
>> + else if (MDNode *IA = DV.getInlinedAt()) {
>> + DebugLoc DL = DebugLoc::getFromDILocation(IA);
>> + Scope = LScopes.findInlinedScope(DebugLoc::get(
>> + DL.getLine(), DL.getCol(), DV.getContext(), IA));
>> + } else
>> + Scope = LScopes.findLexicalScope(DV.getContext());
>> // If variable scope is not found then skip this variable.
>> if (!Scope)
>> continue;
>>
>> Modified: llvm/trunk/lib/CodeGen/LexicalScopes.cpp
>> URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/LexicalScopes.cpp?rev=208506&r1=208505&r2=208506&view=diff
>>
>> ==============================================================================
>> --- llvm/trunk/lib/CodeGen/LexicalScopes.cpp (original)
>> +++ llvm/trunk/lib/CodeGen/LexicalScopes.cpp Sun May 11 13:12:17 2014
>> @@ -104,6 +104,14 @@ void LexicalScopes::extractLexicalScopes
>> }
>> }
>>
>> +LexicalScope *LexicalScopes::findInlinedScope(DebugLoc DL) {
>> + MDNode *Scope = nullptr;
>> + MDNode *IA = nullptr;
>> + DL.getScopeAndInlinedAt(Scope, IA, MF->getFunction()->getContext());
>> + auto I = InlinedLexicalScopeMap.find(std::make_pair(Scope, IA));
>> + return I != InlinedLexicalScopeMap.end() ? &I->second : nullptr;
>> +}
>> +
>> /// findLexicalScope - Find lexical scope, either regular or inlined, for
>> the
>> /// given DebugLoc. Return NULL if not found.
>> LexicalScope *LexicalScopes::findLexicalScope(DebugLoc DL) {
>> @@ -119,8 +127,10 @@ LexicalScope *LexicalScopes::findLexical
>> if (D.isLexicalBlockFile())
>> Scope = DILexicalBlockFile(Scope).getScope();
>>
>> - if (IA)
>> - return
>> InlinedLexicalScopeMap.lookup(DebugLoc::getFromDILocation(IA));
>> + if (IA) {
>> + auto I = InlinedLexicalScopeMap.find(std::make_pair(Scope, IA));
>> + return I != InlinedLexicalScopeMap.end() ? &I->second : nullptr;
>> + }
>> return findLexicalScope(Scope);
>> }
>>
>> @@ -170,21 +180,27 @@ LexicalScope *LexicalScopes::getOrCreate
>> }
>>
>> /// getOrCreateInlinedScope - Find or create an inlined lexical scope.
>> -LexicalScope *LexicalScopes::getOrCreateInlinedScope(MDNode *Scope,
>> +LexicalScope *LexicalScopes::getOrCreateInlinedScope(MDNode *ScopeNode,
>> MDNode *InlinedAt) {
>> - auto I = LexicalScopeMap.find(InlinedAt);
>> - if (I != LexicalScopeMap.end())
>> + std::pair<const MDNode*, const MDNode*> P(ScopeNode, InlinedAt);
>> + auto I = InlinedLexicalScopeMap.find(P);
>> + if (I != InlinedLexicalScopeMap.end())
>> return &I->second;
>>
>> - DebugLoc InlinedLoc = DebugLoc::getFromDILocation(InlinedAt);
>> + LexicalScope *Parent;
>> + DILexicalBlock Scope(ScopeNode);
>> + if (Scope.isLexicalBlock()) {
>> + DILexicalBlock PB(Scope.getContext());
>> + Parent = getOrCreateInlinedScope(PB, InlinedAt);
>> + } else
>> + Parent =
>> getOrCreateLexicalScope(DebugLoc::getFromDILocation(InlinedAt));
>> +
>> // FIXME: Use forward_as_tuple instead of make_tuple, once MSVC2012
>> // compatibility is no longer required.
>> - I = LexicalScopeMap.emplace(
>> - std::piecewise_construct,
>> std::make_tuple(InlinedAt),
>> -
>> std::make_tuple(getOrCreateLexicalScope(InlinedLoc),
>> - DIDescriptor(Scope), InlinedAt,
>> - false)).first;
>> - InlinedLexicalScopeMap[InlinedLoc] = &I->second;
>> + I = InlinedLexicalScopeMap.emplace(std::piecewise_construct,
>> + std::make_tuple(P),
>> + std::make_tuple(Parent, Scope,
>> InlinedAt,
>> + false)).first;
>> return &I->second;
>> }
>>
>>
>> Added: llvm/trunk/test/DebugInfo/inline-scopes.ll
>> URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/inline-scopes.ll?rev=208506&view=auto
>>
>> ==============================================================================
>> --- llvm/trunk/test/DebugInfo/inline-scopes.ll (added)
>> +++ llvm/trunk/test/DebugInfo/inline-scopes.ll Sun May 11 13:12:17 2014
>> @@ -0,0 +1,83 @@
>> +; REQUIRES: object-emission
>> +
>> +; RUN: %llc_dwarf -O0 -filetype=obj < %s | llvm-dwarfdump
>> -debug-dump=info - | FileCheck %s
>> +
>> +; bool f1();
>> +; inline __attribute__((always_inline))
>> +; int f() {
>> +; if (bool b = f1())
>> +; return 1;
>> +; return 2;
>> +; }
>> +;
>> +; int main() {
>> +; f();
>> +; }
>> +
>> +; Ensure that lexical_blocks within inlined_subroutines are
>> preserved/emitted.
>> +; CHECK: DW_TAG_inlined_subroutine
>> +; CHECK-NOT: DW_TAG
>> +; CHECK: DW_TAG_lexical_block
>> +; CHECK: DW_TAG_variable
>> +
>> +; Function Attrs: uwtable
>> +define i32 @main() #0 {
>> +entry:
>> + %retval.i = alloca i32, align 4
>> + %b.i = alloca i8, align 1
>> + call void @llvm.dbg.declare(metadata !{i8* %b.i}, metadata !13), !dbg
>> !16
>> + %call.i = call zeroext i1 @_Z2f1v(), !dbg !16
>> + %frombool.i = zext i1 %call.i to i8, !dbg !16
>> + store i8 %frombool.i, i8* %b.i, align 1, !dbg !16
>> + %0 = load i8* %b.i, align 1, !dbg !16
>> + %tobool.i = trunc i8 %0 to i1, !dbg !16
>> + br i1 %tobool.i, label %if.then.i, label %if.end.i, !dbg !16
>> +
>> +if.then.i: ; preds = %entry
>> + store i32 1, i32* %retval.i, !dbg !18
>> + br label %_Z1fv.exit, !dbg !18
>> +
>> +if.end.i: ; preds = %entry
>> + store i32 2, i32* %retval.i, !dbg !19
>> + br label %_Z1fv.exit, !dbg !19
>> +
>> +_Z1fv.exit: ; preds = %if.then.i,
>> %if.end.i
>> + %1 = load i32* %retval.i, !dbg !20
>> + ret i32 0, !dbg !21
>> +}
>> +
>> +; Function Attrs: nounwind readnone
>> +declare void @llvm.dbg.declare(metadata, metadata) #1
>> +
>> +declare zeroext i1 @_Z2f1v() #2
>> +
>> +attributes #0 = { uwtable "less-precise-fpmad"="false"
>> "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf"
>> "no-infs-fp-math"="false" "no-nans-fp-math"="false"
>> "stack-protector-buffer-size"="8" "unsafe-fp-math"="false"
>> "use-soft-float"="false" }
>> +attributes #1 = { nounwind readnone }
>> +attributes #2 = { "less-precise-fpmad"="false"
>> "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf"
>> "no-infs-fp-math"="false" "no-nans-fp-math"="false"
>> "stack-protector-buffer-size"="8" "unsafe-fp-math"="false"
>> "use-soft-float"="false" }
>> +
>> +!llvm.dbg.cu = !{!0}
>> +!llvm.module.flags = !{!10, !11}
>> +!llvm.ident = !{!12}
>> +
>> +!0 = metadata !{i32 786449, metadata !1, i32 4, metadata !"clang version
>> 3.5.0 ", i1 false, metadata !"", i32 0, metadata !2, metadata !2, metadata
>> !3, metadata !2, metadata !2, metadata !"", i32 1} ; [ DW_TAG_compile_unit ]
>> [/tmp/dbginfo/inline-scopes.cpp] [DW_LANG_C_plus_plus]
>> +!1 = metadata !{metadata !"inline-scopes.cpp", metadata !"/tmp/dbginfo"}
>> +!2 = metadata !{}
>> +!3 = metadata !{metadata !4, metadata !9}
>> +!4 = metadata !{i32 786478, metadata !1, metadata !5, metadata !"main",
>> metadata !"main", metadata !"", i32 9, metadata !6, i1 false, i1 true, i32
>> 0, i32 0, null, i32 256, i1 false, i32 ()* @main, null, null, metadata !2,
>> i32 9} ; [ DW_TAG_subprogram ] [line 9] [def] [main]
>> +!5 = metadata !{i32 786473, metadata !1} ; [ DW_TAG_file_type ]
>> [/tmp/dbginfo/inline-scopes.cpp]
>> +!6 = metadata !{i32 786453, i32 0, null, metadata !"", i32 0, i64 0, i64
>> 0, i64 0, i32 0, null, metadata !7, i32 0, null, null, null} ; [
>> DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
>> +!7 = metadata !{metadata !8}
>> +!8 = metadata !{i32 786468, null, null, metadata !"int", i32 0, i64 32,
>> i64 32, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ] [int] [line 0, size 32,
>> align 32, offset 0, enc DW_ATE_signed]
>> +!9 = metadata !{i32 786478, metadata !1, metadata !5, metadata !"f",
>> metadata !"f", metadata !"_Z1fv", i32 3, metadata !6, i1 false, i1 true, i32
>> 0, i32 0, null, i32 256, i1 false, null, null, null, metadata !2, i32 3} ; [
>> DW_TAG_subprogram ] [line 3] [def] [f]
>> +!10 = metadata !{i32 2, metadata !"Dwarf Version", i32 4}
>> +!11 = metadata !{i32 1, metadata !"Debug Info Version", i32 1}
>> +!12 = metadata !{metadata !"clang version 3.5.0 "}
>> +!13 = metadata !{i32 786688, metadata !14, metadata !"b", metadata !5,
>> i32 4, metadata !15, i32 0, i32 0} ; [ DW_TAG_auto_variable ] [b] [line 4]
>> +!14 = metadata !{i32 786443, metadata !1, metadata !9, i32 4, i32 0, i32
>> 0, i32 0} ; [ DW_TAG_lexical_block ] [/tmp/dbginfo/inline-scopes.cpp]
>> +!15 = metadata !{i32 786468, null, null, metadata !"bool", i32 0, i64 8,
>> i64 8, i64 0, i32 0, i32 2} ; [ DW_TAG_base_type ] [bool] [line 0, size 8,
>> align 8, offset 0, enc DW_ATE_boolean]
>> +!16 = metadata !{i32 4, i32 0, metadata !14, metadata !17}
>> +!17 = metadata !{i32 10, i32 0, metadata !4, null}
>> +!18 = metadata !{i32 5, i32 0, metadata !14, metadata !17}
>> +!19 = metadata !{i32 6, i32 0, metadata !9, metadata !17}
>> +!20 = metadata !{i32 7, i32 0, metadata !9, metadata !17}
>> +!21 = metadata !{i32 11, i32 0, metadata !4, null}
>>
>>
>> _______________________________________________
>> llvm-commits mailing list
>> llvm-commits at cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>
>
>
>
> --
> Alexey Samsonov, Mountain View, CA
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