[llvm] r237733 - [DWARF parser] Make DWARF parser more robust against missing compile/type units.
Rafael Espíndola
rafael.espindola at gmail.com
Tue May 26 07:06:15 PDT 2015
testcase?
On 19 May 2015 at 17:54, Alexey Samsonov <vonosmas at gmail.com> wrote:
> Author: samsonov
> Date: Tue May 19 16:54:32 2015
> New Revision: 237733
>
> URL: http://llvm.org/viewvc/llvm-project?rev=237733&view=rev
> Log:
> [DWARF parser] Make DWARF parser more robust against missing compile/type units.
>
> DWARF standard claims that each compilation/type unit header in
> .debug_info/.debug_types section must be followed by corresponding
> compile/type unit DIE, possibly with its children. Two situations
> are possible:
>
> * compile/type unit DIE is missing because DWARF producer failed to
> emit it.
> * DWARF parser failed to parse unit DIE correctly, for instance if it
> contains some unsupported attributes (see r237721, for instance).
>
> In either of these cases, the library, and the tools that use it
> (llvm-dwarfdump, llvm-symbolizer) should not crash. Insert appropriate
> checks to protect against this.
>
> Modified:
> llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFUnit.h
> llvm/trunk/lib/DebugInfo/DWARF/DWARFCompileUnit.cpp
> llvm/trunk/lib/DebugInfo/DWARF/DWARFContext.cpp
> llvm/trunk/lib/DebugInfo/DWARF/DWARFTypeUnit.cpp
> llvm/trunk/lib/DebugInfo/DWARF/DWARFUnit.cpp
> llvm/trunk/tools/dsymutil/DwarfLinker.cpp
>
> Modified: llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFUnit.h
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFUnit.h?rev=237733&r1=237732&r2=237733&view=diff
> ==============================================================================
> --- llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFUnit.h (original)
> +++ llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFUnit.h Tue May 19 16:54:32 2015
> @@ -195,9 +195,8 @@ public:
> BaseAddr = base_addr;
> }
>
> - const DWARFDebugInfoEntryMinimal *
> - getCompileUnitDIE(bool extract_cu_die_only = true) {
> - extractDIEsIfNeeded(extract_cu_die_only);
> + const DWARFDebugInfoEntryMinimal *getUnitDIE(bool ExtractUnitDIEOnly = true) {
> + extractDIEsIfNeeded(ExtractUnitDIEOnly);
> return DieArray.empty() ? nullptr : &DieArray[0];
> }
>
> @@ -226,8 +225,7 @@ public:
> /// It is illegal to call this method with a DIE that hasn't be
> /// created by this unit. In other word, it's illegal to call this
> /// method on a DIE that isn't accessible by following
> - /// children/sibling links starting from this unit's
> - /// getCompileUnitDIE().
> + /// children/sibling links starting from this unit's getUnitDIE().
> uint32_t getDIEIndex(const DWARFDebugInfoEntryMinimal *DIE) {
> assert(!DieArray.empty() && DIE >= &DieArray[0] &&
> DIE < &DieArray[0] + DieArray.size());
>
> Modified: llvm/trunk/lib/DebugInfo/DWARF/DWARFCompileUnit.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/DebugInfo/DWARF/DWARFCompileUnit.cpp?rev=237733&r1=237732&r2=237733&view=diff
> ==============================================================================
> --- llvm/trunk/lib/DebugInfo/DWARF/DWARFCompileUnit.cpp (original)
> +++ llvm/trunk/lib/DebugInfo/DWARF/DWARFCompileUnit.cpp Tue May 19 16:54:32 2015
> @@ -22,9 +22,10 @@ void DWARFCompileUnit::dump(raw_ostream
> << " (next unit at " << format("0x%08x", getNextUnitOffset())
> << ")\n";
>
> - const DWARFDebugInfoEntryMinimal *CU = getCompileUnitDIE(false);
> - assert(CU && "Null Compile Unit?");
> - CU->dump(OS, this, -1U);
> + if (const DWARFDebugInfoEntryMinimal *CU = getUnitDIE(false))
> + CU->dump(OS, this, -1U);
> + else
> + OS << "<compile unit can't be parsed!>\n\n";
> }
>
> // VTable anchor.
>
> Modified: llvm/trunk/lib/DebugInfo/DWARF/DWARFContext.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/DebugInfo/DWARF/DWARFContext.cpp?rev=237733&r1=237732&r2=237733&view=diff
> ==============================================================================
> --- llvm/trunk/lib/DebugInfo/DWARF/DWARFContext.cpp (original)
> +++ llvm/trunk/lib/DebugInfo/DWARF/DWARFContext.cpp Tue May 19 16:54:32 2015
> @@ -140,9 +140,11 @@ void DWARFContext::dump(raw_ostream &OS,
> OS << "\n.debug_line contents:\n";
> for (const auto &CU : compile_units()) {
> savedAddressByteSize = CU->getAddressByteSize();
> - unsigned stmtOffset =
> - CU->getCompileUnitDIE()->getAttributeValueAsSectionOffset(
> - CU.get(), DW_AT_stmt_list, -1U);
> + const auto *CUDIE = CU->getUnitDIE();
> + if (CUDIE == nullptr)
> + continue;
> + unsigned stmtOffset = CUDIE->getAttributeValueAsSectionOffset(
> + CU.get(), DW_AT_stmt_list, -1U);
> if (stmtOffset != -1U) {
> DataExtractor lineData(getLineSection().Data, isLittleEndian(),
> savedAddressByteSize);
> @@ -321,13 +323,14 @@ const DWARFDebugFrame *DWARFContext::get
> }
>
> const DWARFLineTable *
> -DWARFContext::getLineTableForUnit(DWARFUnit *cu) {
> +DWARFContext::getLineTableForUnit(DWARFUnit *U) {
> if (!Line)
> Line.reset(new DWARFDebugLine(&getLineSection().Relocs));
> -
> + const auto *UnitDIE = U->getUnitDIE();
> + if (UnitDIE == nullptr)
> + return nullptr;
> unsigned stmtOffset =
> - cu->getCompileUnitDIE()->getAttributeValueAsSectionOffset(
> - cu, DW_AT_stmt_list, -1U);
> + UnitDIE->getAttributeValueAsSectionOffset(U, DW_AT_stmt_list, -1U);
> if (stmtOffset == -1U)
> return nullptr; // No line table for this compile unit.
>
> @@ -337,7 +340,7 @@ DWARFContext::getLineTableForUnit(DWARFU
>
> // We have to parse it first.
> DataExtractor lineData(getLineSection().Data, isLittleEndian(),
> - cu->getAddressByteSize());
> + U->getAddressByteSize());
> return Line->getOrParseLineTable(lineData, stmtOffset);
> }
>
>
> Modified: llvm/trunk/lib/DebugInfo/DWARF/DWARFTypeUnit.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/DebugInfo/DWARF/DWARFTypeUnit.cpp?rev=237733&r1=237732&r2=237733&view=diff
> ==============================================================================
> --- llvm/trunk/lib/DebugInfo/DWARF/DWARFTypeUnit.cpp (original)
> +++ llvm/trunk/lib/DebugInfo/DWARF/DWARFTypeUnit.cpp Tue May 19 16:54:32 2015
> @@ -33,7 +33,8 @@ void DWARFTypeUnit::dump(raw_ostream &OS
> << " (next unit at " << format("0x%08x", getNextUnitOffset())
> << ")\n";
>
> - const DWARFDebugInfoEntryMinimal *CU = getCompileUnitDIE(false);
> - assert(CU && "Null Compile Unit?");
> - CU->dump(OS, this, -1U);
> + if (const DWARFDebugInfoEntryMinimal *TU = getUnitDIE(false))
> + TU->dump(OS, this, -1U);
> + else
> + OS << "<type unit can't be parsed!>\n\n";
> }
>
> Modified: llvm/trunk/lib/DebugInfo/DWARF/DWARFUnit.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/DebugInfo/DWARF/DWARFUnit.cpp?rev=237733&r1=237732&r2=237733&view=diff
> ==============================================================================
> --- llvm/trunk/lib/DebugInfo/DWARF/DWARFUnit.cpp (original)
> +++ llvm/trunk/lib/DebugInfo/DWARF/DWARFUnit.cpp Tue May 19 16:54:32 2015
> @@ -310,8 +310,11 @@ void DWARFUnit::clearDIEs(bool KeepCUDie
> }
>
> void DWARFUnit::collectAddressRanges(DWARFAddressRangesVector &CURanges) {
> - // First, check if CU DIE describes address ranges for the unit.
> - const auto &CUDIERanges = getCompileUnitDIE()->getAddressRanges(this);
> + const auto *U = getUnitDIE();
> + if (U == nullptr)
> + return;
> + // First, check if unit DIE describes address ranges for the whole unit.
> + const auto &CUDIERanges = U->getAddressRanges(this);
> if (!CUDIERanges.empty()) {
> CURanges.insert(CURanges.end(), CUDIERanges.begin(), CUDIERanges.end());
> return;
>
> Modified: llvm/trunk/tools/dsymutil/DwarfLinker.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/dsymutil/DwarfLinker.cpp?rev=237733&r1=237732&r2=237733&view=diff
> ==============================================================================
> --- llvm/trunk/tools/dsymutil/DwarfLinker.cpp (original)
> +++ llvm/trunk/tools/dsymutil/DwarfLinker.cpp Tue May 19 16:54:32 2015
> @@ -729,7 +729,7 @@ void DwarfStreamer::emitLocationsForUnit
> const DWARFSection &InputSec = Dwarf.getLocSection();
> DataExtractor Data(InputSec.Data, Dwarf.isLittleEndian(), AddressSize);
> DWARFUnit &OrigUnit = Unit.getOrigUnit();
> - const auto *OrigUnitDie = OrigUnit.getCompileUnitDIE(false);
> + const auto *OrigUnitDie = OrigUnit.getUnitDIE(false);
> int64_t UnitPcOffset = 0;
> uint64_t OrigLowPc = OrigUnitDie->getAttributeValueAsAddress(
> &OrigUnit, dwarf::DW_AT_low_pc, -1ULL);
> @@ -2203,7 +2203,7 @@ void DwarfLinker::patchRangesForUnit(con
> OrigDwarf.isLittleEndian(), AddressSize);
> auto InvalidRange = FunctionRanges.end(), CurrRange = InvalidRange;
> DWARFUnit &OrigUnit = Unit.getOrigUnit();
> - const auto *OrigUnitDie = OrigUnit.getCompileUnitDIE(false);
> + const auto *OrigUnitDie = OrigUnit.getUnitDIE(false);
> uint64_t OrigLowPc = OrigUnitDie->getAttributeValueAsAddress(
> &OrigUnit, dwarf::DW_AT_low_pc, -1ULL);
> // Ranges addresses are based on the unit's low_pc. Compute the
> @@ -2287,7 +2287,7 @@ static void insertLineSequence(std::vect
> void DwarfLinker::patchLineTableForUnit(CompileUnit &Unit,
> DWARFContext &OrigDwarf) {
> const DWARFDebugInfoEntryMinimal *CUDie =
> - Unit.getOrigUnit().getCompileUnitDIE();
> + Unit.getOrigUnit().getUnitDIE();
> uint64_t StmtList = CUDie->getAttributeValueAsSectionOffset(
> &Unit.getOrigUnit(), dwarf::DW_AT_stmt_list, -1ULL);
> if (StmtList == -1ULL)
> @@ -2461,7 +2461,7 @@ bool DwarfLinker::link(const DebugMap &M
> // In a first phase, just read in the debug info and store the DIE
> // parent links that we will use during the next phase.
> for (const auto &CU : DwarfContext.compile_units()) {
> - auto *CUDie = CU->getCompileUnitDIE(false);
> + auto *CUDie = CU->getUnitDIE(false);
> if (Options.Verbose) {
> outs() << "Input compilation unit:";
> CUDie->dump(outs(), CU.get(), 0);
> @@ -2476,7 +2476,7 @@ bool DwarfLinker::link(const DebugMap &M
> // references require the ParentIdx to be setup for every CU in
> // the object file before calling this.
> for (auto &CurrentUnit : Units)
> - lookForDIEsToKeep(*CurrentUnit.getOrigUnit().getCompileUnitDIE(), *Obj,
> + lookForDIEsToKeep(*CurrentUnit.getOrigUnit().getUnitDIE(), *Obj,
> CurrentUnit, 0);
>
> // The calls to applyValidRelocs inside cloneDIE will walk the
> @@ -2489,7 +2489,7 @@ bool DwarfLinker::link(const DebugMap &M
> // to clone/emit.
> if (!ValidRelocs.empty())
> for (auto &CurrentUnit : Units) {
> - const auto *InputDIE = CurrentUnit.getOrigUnit().getCompileUnitDIE();
> + const auto *InputDIE = CurrentUnit.getOrigUnit().getUnitDIE();
> CurrentUnit.setStartOffset(OutputDebugInfoSize);
> DIE *OutputDIE = cloneDIE(*InputDIE, CurrentUnit, 0 /* PCOffset */,
> 11 /* Unit Header size */);
>
>
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