From bc3e96f17bb278358cd3976f35b87591a392f5af Mon Sep 17 00:00:00 2001 From: Manman Ren Date: Tue, 12 Mar 2013 18:27:15 +0000 Subject: Debug Info: use DW_FORM_ref_addr instead of DW_FORM_ref4 if the referenced DIE 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 --- lib/CodeGen/AsmPrinter/DwarfDebug.cpp | 33 ++++++++++++++++++++++++++++++--- 1 file changed, 30 insertions(+), 3 deletions(-) (limited to 'lib/CodeGen/AsmPrinter/DwarfDebug.cpp') diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp index 30bfa78989..2da0bb3364 100644 --- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp +++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp @@ -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::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 *Abbrevs) { DIEEntry *E = cast(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::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; -- cgit v1.2.3-18-g5258