[llvm] r358281 - Revert r358268 "[DebugInfo] DW_OP_deref_size in PrologEpilogInserter."
Hans Wennborg via llvm-commits
llvm-commits at lists.llvm.org
Fri Apr 12 05:54:52 PDT 2019
Author: hans
Date: Fri Apr 12 05:54:52 2019
New Revision: 358281
URL: http://llvm.org/viewvc/llvm-project?rev=358281&view=rev
Log:
Revert r358268 "[DebugInfo] DW_OP_deref_size in PrologEpilogInserter."
It causes clang to crash while building Chromium. See https://crbug.com/952230
for reproducer.
> The PrologEpilogInserter need to insert a DW_OP_deref_size before
> prepending a memory location expression to an already implicit
> expression to avoid having the existing expression act on the memory
> address instead of the value behind it.
>
> The reason for using DW_OP_deref_size and not plain DW_OP_deref is that
> big-endian targets need to read the right size as simply truncating a
> larger read would yield the wrong result (LSB bytes are not at the lower
> address).
>
> Differential Revision: https://reviews.llvm.org/D59687
Removed:
llvm/trunk/test/CodeGen/X86/prologepilog_deref_size.mir
Modified:
llvm/trunk/include/llvm/IR/DebugInfoMetadata.h
llvm/trunk/lib/CodeGen/AsmPrinter/DwarfExpression.cpp
llvm/trunk/lib/CodeGen/MIRParser/MIParser.cpp
llvm/trunk/lib/CodeGen/PrologEpilogInserter.cpp
llvm/trunk/lib/IR/DebugInfoMetadata.cpp
Modified: llvm/trunk/include/llvm/IR/DebugInfoMetadata.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/IR/DebugInfoMetadata.h?rev=358281&r1=358280&r2=358281&view=diff
==============================================================================
--- llvm/trunk/include/llvm/IR/DebugInfoMetadata.h (original)
+++ llvm/trunk/include/llvm/IR/DebugInfoMetadata.h Fri Apr 12 05:54:52 2019
@@ -2510,9 +2510,6 @@ public:
/// Return whether this is a piece of an aggregate variable.
bool isFragment() const { return getFragmentInfo().hasValue(); }
- /// Return whether this is an implicit location description.
- bool isImplicit() const;
-
/// Append \p Ops with operations to apply the \p Offset.
static void appendOffset(SmallVectorImpl<uint64_t> &Ops, int64_t Offset);
Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfExpression.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfExpression.cpp?rev=358281&r1=358280&r2=358281&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfExpression.cpp (original)
+++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfExpression.cpp Fri Apr 12 05:54:52 2019
@@ -434,10 +434,6 @@ void DwarfExpression::addExpression(DIEx
assert(LocationKind != Register);
emitOp(dwarf::DW_OP_xderef);
break;
- case dwarf::DW_OP_deref_size:
- emitOp(dwarf::DW_OP_deref_size);
- emitUnsigned(Op->getArg(0));
- break;
default:
llvm_unreachable("unhandled opcode found in expression");
}
Modified: llvm/trunk/lib/CodeGen/MIRParser/MIParser.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/MIRParser/MIParser.cpp?rev=358281&r1=358280&r2=358281&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/MIRParser/MIParser.cpp (original)
+++ llvm/trunk/lib/CodeGen/MIRParser/MIParser.cpp Fri Apr 12 05:54:52 2019
@@ -1854,11 +1854,6 @@ bool MIParser::parseDIExpression(MDNode
Elements.push_back(Op);
continue;
}
- if (unsigned Enc = dwarf::getAttributeEncoding(Token.stringValue())) {
- lex();
- Elements.push_back(Enc);
- continue;
- }
return error(Twine("invalid DWARF op '") + Token.stringValue() + "'");
}
Modified: llvm/trunk/lib/CodeGen/PrologEpilogInserter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/PrologEpilogInserter.cpp?rev=358281&r1=358280&r2=358281&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/PrologEpilogInserter.cpp (original)
+++ llvm/trunk/lib/CodeGen/PrologEpilogInserter.cpp Fri Apr 12 05:54:52 2019
@@ -1172,22 +1172,12 @@ void PEI::replaceFrameIndices(MachineBas
assert(i == 0 && "Frame indices can only appear as the first "
"operand of a DBG_VALUE machine instruction");
unsigned Reg;
- unsigned FrameIdx = MI.getOperand(0).getIndex();
- unsigned Size = MF.getFrameInfo().getObjectSize(FrameIdx);
-
int64_t Offset =
- TFI->getFrameIndexReference(MF, FrameIdx, Reg);
+ TFI->getFrameIndexReference(MF, MI.getOperand(0).getIndex(), Reg);
MI.getOperand(0).ChangeToRegister(Reg, false /*isDef*/);
MI.getOperand(0).setIsDebug();
-
- const DIExpression *DIExpr = MI.getDebugExpression();
- // If we already have a Implicit location expression we need to insert
- // a deref before prepending a Memory location expression.
- if (DIExpr->isImplicit()) {
- SmallVector<uint64_t, 2> Ops = {dwarf::DW_OP_deref_size, Size};
- DIExpr = DIExpression::prependOpcodes(DIExpr, Ops, DIExpression::WithStackValue);
- }
- DIExpr = DIExpression::prepend(DIExpr, DIExpression::NoDeref, Offset);
+ auto *DIExpr = DIExpression::prepend(MI.getDebugExpression(),
+ DIExpression::NoDeref, Offset);
MI.getOperand(3).setMetadata(DIExpr);
continue;
}
Modified: llvm/trunk/lib/IR/DebugInfoMetadata.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/DebugInfoMetadata.cpp?rev=358281&r1=358280&r2=358281&view=diff
==============================================================================
--- llvm/trunk/lib/IR/DebugInfoMetadata.cpp (original)
+++ llvm/trunk/lib/IR/DebugInfoMetadata.cpp Fri Apr 12 05:54:52 2019
@@ -833,7 +833,6 @@ unsigned DIExpression::ExprOperand::getS
case dwarf::DW_OP_LLVM_fragment:
return 3;
case dwarf::DW_OP_constu:
- case dwarf::DW_OP_deref_size:
case dwarf::DW_OP_plus_uconst:
return 2;
default:
@@ -890,7 +889,6 @@ bool DIExpression::isValid() const {
case dwarf::DW_OP_shr:
case dwarf::DW_OP_shra:
case dwarf::DW_OP_deref:
- case dwarf::DW_OP_deref_size:
case dwarf::DW_OP_xderef:
case dwarf::DW_OP_lit0:
case dwarf::DW_OP_not:
@@ -901,19 +899,6 @@ bool DIExpression::isValid() const {
return true;
}
-bool DIExpression::isImplicit() const {
- unsigned N = getNumElements();
- if (isValid() && N > 0) {
- switch (getElement(N-1)) {
- case dwarf::DW_OP_stack_value: return true;
- case dwarf::DW_OP_LLVM_fragment:
- return N > 1 && getElement(N-2) == dwarf::DW_OP_stack_value;
- default: break;
- }
- }
- return false;
-}
-
Optional<DIExpression::FragmentInfo>
DIExpression::getFragmentInfo(expr_op_iterator Start, expr_op_iterator End) {
for (auto I = Start; I != End; ++I)
Removed: llvm/trunk/test/CodeGen/X86/prologepilog_deref_size.mir
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/prologepilog_deref_size.mir?rev=358280&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/prologepilog_deref_size.mir (original)
+++ llvm/trunk/test/CodeGen/X86/prologepilog_deref_size.mir (removed)
@@ -1,59 +0,0 @@
-# RUN: llc -run-pass=prologepilog -o - %s | FileCheck %s
---- |
- ; ModuleID = 'dbg.opt.ll'
- source_filename = "dbg.c"
- target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
- target triple = "x86_64-unknown-linux-gnu"
-
- ; Function Attrs: noinline nounwind uwtable
- define dso_local zeroext i16 @foo(i16 zeroext %d0, i16 zeroext %d1, i16 zeroext %d2, i16 zeroext %d3, i16 zeroext %d4, i16 zeroext %d5, i16 zeroext %d6, i16 zeroext %d7, i16 zeroext %d8, i16 signext %x) #0 !dbg !7 {
- entry:
- call void @llvm.dbg.value(metadata i16 %x, metadata !32, metadata !DIExpression(DW_OP_LLVM_convert, 16, DW_ATE_signed, DW_OP_LLVM_convert, 32, DW_ATE_signed, DW_OP_stack_value)), !dbg !34
- ret i16 %x
- }
-
- ; Function Attrs: nounwind readnone speculatable
- declare void @llvm.dbg.value(metadata, metadata, metadata) #1
-
- attributes #0 = { noinline nounwind uwtable }
- attributes #1 = { nounwind readnone speculatable }
-
- !llvm.dbg.cu = !{!0}
- !llvm.module.flags = !{!3, !4, !5}
- !llvm.ident = !{!6}
-
- !0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 9.0.0", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
- !1 = !DIFile(filename: "dbg.c", directory: "/tmp")
- !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 9.0.0"}
- !7 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 2, type: !8, scopeLine: 2, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !2)
- !8 = !DISubroutineType(types: !9)
- !9 = !{!10, !10, !10, !10, !10, !10, !10, !10, !10, !10, !10}
- !10 = !DIDerivedType(tag: DW_TAG_typedef, name: "T", file: !1, line: 1, baseType: !11)
- !11 = !DIBasicType(name: "signed short", size: 16, encoding: DW_ATE_signed)
- !32 = !DILocalVariable(name: "y", scope: !7, file: !1, line: 3, type: !33)
- !33 = !DIBasicType(name: "signed int", size: 32, encoding: DW_ATE_signed)
- !34 = !DILocation(line: 3, column: 20, scope: !7)
-
-...
----
-name: foo
-tracksRegLiveness: true
-fixedStack:
- - { id: 0, type: default, offset: 24, size: 2, alignment: 8, stack-id: 0,
- isImmutable: true, isAliased: false, callee-saved-register: '', callee-saved-restored: true,
- debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
-stack: []
-constants: []
-machineFunctionInfo: {}
-body: |
- bb.0.entry:
- renamable $ax = MOV16rm %fixed-stack.0, 1, $noreg, 0, $noreg :: (load 2 from %fixed-stack.0, align 8)
- DBG_VALUE %fixed-stack.0, 0, !32, !DIExpression(DW_OP_LLVM_convert, 16, DW_ATE_signed, DW_OP_LLVM_convert, 32, DW_ATE_signed, DW_OP_stack_value), debug-location !34
- RET 0, $ax
-...
-# CHECK: machineFunctionInfo
-# CHECK: DIExpression(DW_OP_plus_uconst, {{[0-9]+}}, DW_OP_deref_size, 2, DW_OP_LLVM_convert, 16, DW_ATE_signed, DW_OP_LLVM_convert, 32, DW_ATE_signed, DW_OP_stack_value)
More information about the llvm-commits
mailing list