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Debug Info: use DW_FORM_ref_addr instead of DW_FORM_ref4 if the referenced DIE

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belongs to a different compile unit.

DW_FORM_ref_addr should be used for cross compile-unit reference.

When compiling a large application, we got a dwarfdump verification error where
abstract_origin points to nowhere.

This error can't be reproduced on any testing case in MultiSource.
We may have other cases where we use DW_FORM_ref4 unconditionally.

rdar://problem/13370501


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176882 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Manman Ren
2013-03-12 18:27:15 +00:00
parent 1a5c0510ec
commit bc3e96f17b
6 changed files with 54 additions and 4 deletions
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33
lib/CodeGen/AsmPrinter/DwarfDebug.cpp
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@ -352,11 +352,16 @@ DIE *DwarfDebug::updateSubprogramScopeDIE(CompileUnit *SPCU,
// If we're updating an abstract DIE, then we will be adding the children and
// object pointer later on. But what we don't want to do is process the
// concrete DIE twice.
if (DIE *AbsSPDIE = AbstractSPDies.lookup(SPNode)) {
DIE *AbsSPDIE = AbstractSPDies.lookup(SPNode);
if (AbsSPDIE) {
bool InSameCU = (AbsSPDIE->getCompileUnit() == SPCU->getCUDie());
// Pick up abstract subprogram DIE.
SPDie = new DIE(dwarf::DW_TAG_subprogram);
// If AbsSPDIE belongs to a different CU, use DW_FORM_ref_addr instead of
// DW_FORM_ref4.
SPCU->addDIEEntry(SPDie, dwarf::DW_AT_abstract_origin,
dwarf::DW_FORM_ref4, AbsSPDIE);
InSameCU ? dwarf::DW_FORM_ref4 : dwarf::DW_FORM_ref_addr,
AbsSPDIE);
SPCU->addDie(SPDie);
} else {
DISubprogram SPDecl = SP.getFunctionDeclaration();
@ -1692,15 +1697,19 @@ DwarfUnits::computeSizeAndOffset(DIE *Die, unsigned Offset) {
// Compute the size and offset of all the DIEs.
void DwarfUnits::computeSizeAndOffsets() {
// Offset from the beginning of debug info section.
unsigned AccuOffset = 0;
for (SmallVector<CompileUnit *, 1>::iterator I = CUs.begin(),
E = CUs.end(); I != E; ++I) {
(*I)->setDebugInfoOffset(AccuOffset);
unsigned Offset =
sizeof(int32_t) + // Length of Compilation Unit Info
sizeof(int16_t) + // DWARF version number
sizeof(int32_t) + // Offset Into Abbrev. Section
sizeof(int8_t); // Pointer Size (in bytes)
computeSizeAndOffset((*I)->getCUDie(), Offset);
unsigned EndOffset = computeSizeAndOffset((*I)->getCUDie(), Offset);
AccuOffset += EndOffset;
}
}
@ -1774,6 +1783,13 @@ void DwarfDebug::emitDIE(DIE *Die, std::vector<DIEAbbrev *> *Abbrevs) {
DIEEntry *E = cast<DIEEntry>(Values[i]);
DIE *Origin = E->getEntry();
unsigned Addr = Origin->getOffset();
if (Form == dwarf::DW_FORM_ref_addr) {
// For DW_FORM_ref_addr, output the offset from beginning of debug info
// section. Origin->getOffset() returns the offset from start of the
// compile unit.
DwarfUnits &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
Addr += Holder.getCUOffset(Origin->getCompileUnit());
}
Asm->EmitInt32(Addr);
break;
}
@ -1871,6 +1887,17 @@ void DwarfUnits::emitUnits(DwarfDebug *DD,
}
}
/// For a given compile unit DIE, returns offset from beginning of debug info.
unsigned DwarfUnits::getCUOffset(DIE *Die) {
for (SmallVector<CompileUnit *, 1>::iterator I = CUs.begin(),
E = CUs.end(); I != E; ++I) {
CompileUnit *TheCU = *I;
if (TheCU->getCUDie() == Die)
return TheCU->getDebugInfoOffset();
}
return 0;
}
// Emit the debug info section.
void DwarfDebug::emitDebugInfo() {
DwarfUnits &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;