[llvm] r239380 - [DWARF] Fix a few corner cases in expression emission
David Blaikie
dblaikie at gmail.com
Tue Jun 9 11:06:13 PDT 2015
On Mon, Jun 8, 2015 at 9:05 PM, David Blaikie <dblaikie at gmail.com> wrote:
> Looks like this might've caused:
>
> http://lab.llvm.org:8011/builders/clang-x86_64-ubuntu-gdb-75/builds/22562
>
Reverted in r239420 to hopefully get the buildbot back to green.
>
>
> On Mon, Jun 8, 2015 at 6:54 PM, Keno Fischer <kfischer at college.harvard.edu
> > wrote:
>
>> Author: kfischer
>> Date: Mon Jun 8 20:53:59 2015
>> New Revision: 239380
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=239380&view=rev
>> Log:
>> [DWARF] Fix a few corner cases in expression emission
>>
>> Summary: I noticed an object file with `DW_OP_reg4 DW_OP_breg4 0` as a
>> DWARF expression,
>> which I traced to a missing break (and `++I`) in this code snippet.
>> While I was at it, I also added support for a few other corner cases
>> along the same lines that I could think of.
>>
>> Test Plan: Hand-crafted test case to exercises these cases is included.
>>
>> Reviewers: echristo, dblaikie, aprantl
>>
>> Reviewed By: aprantl
>>
>> Subscribers: llvm-commits
>>
>> Differential Revision: http://reviews.llvm.org/D10302
>>
>> Added:
>> llvm/trunk/test/DebugInfo/expressions.ll
>> Modified:
>> llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
>> llvm/trunk/lib/CodeGen/AsmPrinter/DwarfExpression.cpp
>> llvm/trunk/lib/CodeGen/AsmPrinter/DwarfExpression.h
>>
>> Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
>> URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp?rev=239380&r1=239379&r2=239380&view=diff
>>
>> ==============================================================================
>> --- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp (original)
>> +++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp Mon Jun 8 20:53:59
>> 2015
>> @@ -1562,6 +1562,8 @@ void DwarfDebug::emitDebugLoc() {
>> Asm->OutStreamer->EmitLabel(List.Label);
>> const DwarfCompileUnit *CU = List.CU;
>> for (const auto &Entry : DebugLocs.getEntries(List)) {
>> + if (Entry.BeginSym == Entry.EndSym)
>> + continue;
>> // Set up the range. This range is relative to the entry point of
>> the
>> // compile unit. This is a hard coded 0 for low_pc when we're
>> emitting
>> // ranges, or the DW_AT_low_pc on the compile unit otherwise.
>>
>> Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfExpression.cpp
>> URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfExpression.cpp?rev=239380&r1=239379&r2=239380&view=diff
>>
>> ==============================================================================
>> --- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfExpression.cpp (original)
>> +++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfExpression.cpp Mon Jun 8
>> 20:53:59 2015
>> @@ -65,6 +65,11 @@ void DwarfExpression::AddShr(unsigned Sh
>> EmitOp(dwarf::DW_OP_shr);
>> }
>>
>> +void DwarfExpression::AddOpStackValue() {
>> + if (DwarfVersion >= 4)
>> + EmitOp(dwarf::DW_OP_stack_value);
>> +}
>> +
>> bool DwarfExpression::AddMachineRegIndirect(unsigned MachineReg, int
>> Offset) {
>> if (isFrameRegister(MachineReg)) {
>> // If variable offset is based in frame register then use fbreg.
>> @@ -172,16 +177,14 @@ void DwarfExpression::AddSignedConstant(
>> // value, so the producers and consumers started to rely on heuristics
>> // to disambiguate the value vs. location status of the expression.
>> // See PR21176 for more details.
>> - if (DwarfVersion >= 4)
>> - EmitOp(dwarf::DW_OP_stack_value);
>> + AddOpStackValue();
>> }
>>
>> void DwarfExpression::AddUnsignedConstant(unsigned Value) {
>> EmitOp(dwarf::DW_OP_constu);
>> EmitUnsigned(Value);
>> // cf. comment in DwarfExpression::AddSignedConstant().
>> - if (DwarfVersion >= 4)
>> - EmitOp(dwarf::DW_OP_stack_value);
>> + AddOpStackValue();
>> }
>>
>> static unsigned getOffsetOrZero(unsigned OffsetInBits,
>> @@ -212,15 +215,30 @@ bool DwarfExpression::AddMachineRegExpre
>> getOffsetOrZero(OffsetInBits, PieceOffsetInBits));
>> }
>> case dwarf::DW_OP_plus: {
>> - // [DW_OP_reg,Offset,DW_OP_plus,DW_OP_deref] --> [DW_OP_breg,Offset].
>> auto N = I.getNext();
>> + unsigned Offset = I->getArg(0);
>> + // First combine all DW_OP_plus until we hit either a DW_OP_deref or
>> a
>> + // DW_OP_bit_piece
>> + while (N != E && N->getOp() == dwarf::DW_OP_plus) {
>> + Offset += N->getArg(0);
>> + ++I;
>> + N = I.getNext();
>> + }
>> if (N != E && N->getOp() == dwarf::DW_OP_deref) {
>> - unsigned Offset = I->getArg(0);
>> + // [DW_OP_reg,Offset,DW_OP_plus,DW_OP_deref] -->
>> [DW_OP_breg,Offset].
>> ValidReg = AddMachineRegIndirect(MachineReg, Offset);
>> std::advance(I, 2);
>> - break;
>> - } else
>> - ValidReg = AddMachineRegPiece(MachineReg);
>> + } else {
>> + assert ((N == E) || (N->getOp() == dwarf::DW_OP_bit_piece));
>> + if (Offset == 0) {
>> + ValidReg = AddMachineRegPiece(MachineReg);
>> + } else {
>> + ValidReg = AddMachineRegIndirect(MachineReg, Offset);
>> + AddOpStackValue();
>> + }
>> + ++I;
>> + }
>> + break;
>> }
>> case dwarf::DW_OP_deref: {
>> // [DW_OP_reg,DW_OP_deref] --> [DW_OP_breg].
>> @@ -237,6 +255,7 @@ bool DwarfExpression::AddMachineRegExpre
>>
>> // Emit remaining elements of the expression.
>> AddExpression(I, E, PieceOffsetInBits);
>> +
>> return true;
>> }
>>
>>
>> Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfExpression.h
>> URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfExpression.h?rev=239380&r1=239379&r2=239380&view=diff
>>
>> ==============================================================================
>> --- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfExpression.h (original)
>> +++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfExpression.h Mon Jun 8
>> 20:53:59 2015
>> @@ -83,6 +83,9 @@ public:
>> bool AddMachineRegPiece(unsigned MachineReg, unsigned PieceSizeInBits
>> = 0,
>> unsigned PieceOffsetInBits = 0);
>>
>> + /// Emit a DW_OP_stack_value
>> + void AddOpStackValue();
>> +
>> /// Emit a signed constant.
>> void AddSignedConstant(int Value);
>> /// Emit an unsigned constant.
>>
>> Added: llvm/trunk/test/DebugInfo/expressions.ll
>> URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/expressions.ll?rev=239380&view=auto
>>
>> ==============================================================================
>> --- llvm/trunk/test/DebugInfo/expressions.ll (added)
>> +++ llvm/trunk/test/DebugInfo/expressions.ll Mon Jun 8 20:53:59 2015
>> @@ -0,0 +1,110 @@
>> +; REQUIRES: object-emission
>> +; RUN: %llc_dwarf -mtriple x86_64-apple-darwin14.0.0-elf -filetype=obj
>> %s -o %t
>> +; RUN: %llc_dwarf -mtriple x86_64-apple-darwin14.0.0-elf -O0
>> -filetype=obj %s -o %t0
>> +; RUN: llvm-dwarfdump -debug-dump=loc %t | FileCheck %s
>> +; RUN: llvm-dwarfdump -debug-dump=loc %t0 | FileCheck -check-prefix
>> CHECK-O0 %s
>> +
>> +; CHECK: 0x00000000: Beginning address offset: 0x0000000000000000
>> +; CHECK: Ending address offset: 0x[[END:[0-9a-f]+]]
>> +; CHECK: Location description:
>> +; CHECK-NOT: 75 00 55
>> +; CHECK-SAME: 55
>> +; CHECK: 0x00000023: Beginning address offset: 0x0000000000000000
>> +; CHECK: Ending address offset: 0x{{.*}}[[END]]
>> +; CHECK: Location description: 75 08 9f
>> +; CHECK: 0x00000048: Beginning address offset: 0x0000000000000000
>> +; CHECK: Ending address offset: 0x{{.*}}[[END]]
>> +; CHECK: Location description: 75 10 9f
>> +; CHECK: 0x0000006d: Beginning address offset: 0x0000000000000000
>> +; CHECK: Ending address offset: 0x{{.*}}[[END]]
>> +; CHECK: Location description: 75 18
>> +
>> +
>> +; CHECK-O0: 0x00000000: Beginning address offset: 0x0000000000000000
>> +; CHECK-O0: Ending address offset: 0x000000000000001b
>> +; CHECK-O0: Location description: 55
>> +; CHECK-O0: Beginning address offset: 0x000000000000001b
>> +; CHECK-O0: Ending address offset: 0x0000000000000024
>> +; CHECK-O0: Location description: 54
>> +; CHECK-O0: Beginning address offset: 0x0000000000000024
>> +; CHECK-O0: Ending address offset: 0x0000000000000025
>> +; CHECK-O0: Location description: 77 78 23 00
>> +; CHECK-O0: 0x0000004c: Beginning address offset: 0x0000000000000000
>> +; CHECK-O0: Ending address offset: 0x000000000000001b
>> +; CHECK-O0: Location description: 75 08 9f
>> +; CHECK-O0: Beginning address offset: 0x000000000000001b
>> +; CHECK-O0: Ending address offset: 0x0000000000000024
>> +; CHECK-O0: Location description: 74 08 9f
>> +; CHECK-O0: Beginning address offset: 0x0000000000000024
>> +; CHECK-O0: Ending address offset: 0x0000000000000025
>> +; CHECK-O0: Location description: 77 78 23 08
>> +; CHECK-O0: 0x0000009c: Beginning address offset: 0x0000000000000000
>> +; CHECK-O0: Ending address offset: 0x000000000000001b
>> +; CHECK-O0: Location description: 75 10 9f
>> +; CHECK-O0: Beginning address offset: 0x000000000000001b
>> +; CHECK-O0: Ending address offset: 0x0000000000000024
>> +; CHECK-O0: Location description: 74 10 9f
>> +; CHECK-O0: Beginning address offset: 0x0000000000000024
>> +; CHECK-O0: Ending address offset: 0x0000000000000025
>> +; CHECK-O0: Location description: 77 78 23 08 23 08
>> +; CHECK-O0: 0x000000ee: Beginning address offset: 0x0000000000000000
>> +; CHECK-O0: Ending address offset: 0x000000000000001b
>> +; CHECK-O0: Location description: 75 18
>> +; CHECK-O0: Beginning address offset: 0x000000000000001b
>> +; CHECK-O0: Ending address offset: 0x0000000000000024
>> +; CHECK-O0: Location description: 74 18
>> +; CHECK-O0: Beginning address offset: 0x0000000000000024
>> +; CHECK-O0: Ending address offset: 0x0000000000000025
>> +; CHECK-O0: Location description: 77 78 23 10 23 08 06
>> +
>> +declare void @llvm.dbg.value(metadata, i64, metadata, metadata) #0
>> +
>> +define float @foo(float* %args, float *%args2)
>> +{
>> + call void @llvm.dbg.value(metadata float* %args, i64 0, metadata
>> !11, metadata !12), !dbg !19
>> + call void @llvm.dbg.value(metadata float* %args, i64 0, metadata
>> !13, metadata !14), !dbg !19
>> + call void @llvm.dbg.value(metadata float* %args, i64 0, metadata
>> !15, metadata !16), !dbg !19
>> + call void @llvm.dbg.value(metadata float* %args, i64 0, metadata
>> !17, metadata !18), !dbg !19
>> + %a = load float, float* %args, !dbg !19
>> + %bptr = getelementptr float, float* %args, i32 1, !dbg !19
>> + %b = load float, float* %bptr, !dbg !19
>> + %cptr = getelementptr float, float* %args, i32 2, !dbg !19
>> + %c = load float, float* %cptr, !dbg !19
>> + %dptr = getelementptr float, float* %args, i32 3, !dbg !19
>> + %d = load float, float* %dptr, !dbg !19
>> + %ret1 = fadd float %a, %b, !dbg !19
>> + %ret2 = fadd float %c, %d, !dbg !19
>> + call void @llvm.dbg.value(metadata float* %args2, i64 0, metadata
>> !11, metadata !12), !dbg !19
>> + call void @llvm.dbg.value(metadata float* %args2, i64 0, metadata
>> !13, metadata !14), !dbg !19
>> + call void @llvm.dbg.value(metadata float* %args2, i64 0, metadata
>> !15, metadata !16), !dbg !19
>> + call void @llvm.dbg.value(metadata float* %args2, i64 0, metadata
>> !17, metadata !18), !dbg !19
>> + %ret = fsub float %ret1, %ret2, !dbg !19
>> + ret float %ret, !dbg !19
>> +}
>> +
>> +attributes #0 = { nounwind readnone }
>> +
>> +!llvm.module.flags = !{!0, !1}
>> +!llvm.dbg.cu = !{!2}
>> +
>> +!0 = !{i32 2, !"Dwarf Version", i32 4}
>> +!1 = !{i32 1, !"Debug Info Version", i32 3}
>> +
>> +!2 = !DICompileUnit(language: DW_LANG_C89, file: !3, producer: "byHand",
>> isOptimized: true, runtimeVersion: 0, emissionKind: 1, enums: !4,
>> retainedTypes: !4, subprograms: !5, globals: !4, imports: !4)
>> +!3 = !DIFile(filename: "expressions", directory: ".")
>> +!4 = !{}
>> +!5 = !{!6}
>> +!6 = !DISubprogram(name: "foo", linkageName: "foo", scope: null, file:
>> !3, type: !7, isLocal: false, isDefinition: true, isOptimized: true,
>> function: float (float*, float*)* @foo, variables: !4)
>> +!7 = !DISubroutineType(types: !8)
>> +!8 = !{!10, !10}
>> +!9 = !DIBasicType(name: "float", size: 4, align: 4, encoding:
>> DW_ATE_float)
>> +!10 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !9, size: 64,
>> align: 64)
>> +!11 = !DILocalVariable(tag: DW_TAG_arg_variable, name: "a", arg: 1,
>> scope: !6, file: !3, line: 1, type: !10)
>> +!12 = !DIExpression(DW_OP_plus, 0)
>> +!13 = !DILocalVariable(tag: DW_TAG_arg_variable, name: "b", arg: 2,
>> scope: !6, file: !3, line: 1, type: !10)
>> +!14 = !DIExpression(DW_OP_plus, 8)
>> +!15 = !DILocalVariable(tag: DW_TAG_arg_variable, name: "c", arg: 3,
>> scope: !6, file: !3, line: 1, type: !10)
>> +!16 = !DIExpression(DW_OP_plus, 8, DW_OP_plus, 8)
>> +!17 = !DILocalVariable(tag: DW_TAG_arg_variable, name: "d", arg: 4,
>> scope: !6, file: !3, line: 1, type: !9)
>> +!18 = !DIExpression(DW_OP_plus, 16, DW_OP_plus, 8, DW_OP_deref)
>> +!19 = !DILocation(line: 1, scope: !6)
>>
>>
>> _______________________________________________
>> llvm-commits mailing list
>> llvm-commits at cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20150609/a590da29/attachment.html>
More information about the llvm-commits
mailing list