Reapply "DWARFVerifier: Check "completeness" of .debug_names section"
This is a resubmit of r331868 (D46583), which was reverted due to
failures on the PS4 bot.
These have been resolved with r332246/D46748.
llvm-svn: 332349
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFVerifier.cpp b/llvm/lib/DebugInfo/DWARF/DWARFVerifier.cpp
index 99eab98..4f1095c 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFVerifier.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFVerifier.cpp
@@ -1142,6 +1142,141 @@
return NumErrors;
}
+static bool isVariableIndexable(const DWARFDie &Die, DWARFContext &DCtx) {
+ Optional<DWARFFormValue> Location = Die.findRecursively(DW_AT_location);
+ if (!Location)
+ return false;
+
+ auto ContainsInterestingOperators = [&](StringRef D) {
+ DWARFUnit *U = Die.getDwarfUnit();
+ DataExtractor Data(D, DCtx.isLittleEndian(), U->getAddressByteSize());
+ DWARFExpression Expression(Data, U->getVersion(), U->getAddressByteSize());
+ return any_of(Expression, [](DWARFExpression::Operation &Op) {
+ return !Op.isError() && (Op.getCode() == DW_OP_addr ||
+ Op.getCode() == DW_OP_form_tls_address ||
+ Op.getCode() == DW_OP_GNU_push_tls_address);
+ });
+ };
+
+ if (Optional<ArrayRef<uint8_t>> Expr = Location->getAsBlock()) {
+ // Inlined location.
+ if (ContainsInterestingOperators(toStringRef(*Expr)))
+ return true;
+ } else if (Optional<uint64_t> Offset = Location->getAsSectionOffset()) {
+ // Location list.
+ if (const DWARFDebugLoc *DebugLoc = DCtx.getDebugLoc()) {
+ if (const DWARFDebugLoc::LocationList *LocList =
+ DebugLoc->getLocationListAtOffset(*Offset)) {
+ if (any_of(LocList->Entries, [&](const DWARFDebugLoc::Entry &E) {
+ return ContainsInterestingOperators({E.Loc.data(), E.Loc.size()});
+ }))
+ return true;
+ }
+ }
+ }
+ return false;
+}
+
+unsigned DWARFVerifier::verifyNameIndexCompleteness(
+ const DWARFDie &Die, const DWARFDebugNames::NameIndex &NI) {
+
+ // First check, if the Die should be indexed. The code follows the DWARF v5
+ // wording as closely as possible.
+
+ // "All non-defining declarations (that is, debugging information entries
+ // with a DW_AT_declaration attribute) are excluded."
+ if (Die.find(DW_AT_declaration))
+ return 0;
+
+ // "DW_TAG_namespace debugging information entries without a DW_AT_name
+ // attribute are included with the name “(anonymous namespace)”.
+ // All other debugging information entries without a DW_AT_name attribute
+ // are excluded."
+ // "If a subprogram or inlined subroutine is included, and has a
+ // DW_AT_linkage_name attribute, there will be an additional index entry for
+ // the linkage name."
+ auto EntryNames = getNames(Die);
+ if (EntryNames.empty())
+ return 0;
+
+ // We deviate from the specification here, which says:
+ // "The name index must contain an entry for each debugging information entry
+ // that defines a named subprogram, label, variable, type, or namespace,
+ // subject to ..."
+ // Instead whitelisting all TAGs representing a "type" or a "subprogram", to
+ // make sure we catch any missing items, we instead blacklist all TAGs that we
+ // know shouldn't be indexed.
+ switch (Die.getTag()) {
+ // Compile unit has a name but it shouldn't be indexed.
+ case DW_TAG_compile_unit:
+ return 0;
+
+ // Function and template parameters are not globally visible, so we shouldn't
+ // index them.
+ case DW_TAG_formal_parameter:
+ case DW_TAG_template_value_parameter:
+ case DW_TAG_template_type_parameter:
+ case DW_TAG_GNU_template_parameter_pack:
+ case DW_TAG_GNU_template_template_param:
+ return 0;
+
+ // Object members aren't globally visible.
+ case DW_TAG_member:
+ return 0;
+
+ // According to a strict reading of the specification, enumerators should not
+ // be indexed (and LLVM currently does not do that). However, this causes
+ // problems for the debuggers, so we may need to reconsider this.
+ case DW_TAG_enumerator:
+ return 0;
+
+ // Imported declarations should not be indexed according to the specification
+ // and LLVM currently does not do that.
+ case DW_TAG_imported_declaration:
+ return 0;
+
+ // "DW_TAG_subprogram, DW_TAG_inlined_subroutine, and DW_TAG_label debugging
+ // information entries without an address attribute (DW_AT_low_pc,
+ // DW_AT_high_pc, DW_AT_ranges, or DW_AT_entry_pc) are excluded."
+ case DW_TAG_subprogram:
+ case DW_TAG_inlined_subroutine:
+ case DW_TAG_label:
+ if (Die.findRecursively(
+ {DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_entry_pc}))
+ break;
+ return 0;
+
+ // "DW_TAG_variable debugging information entries with a DW_AT_location
+ // attribute that includes a DW_OP_addr or DW_OP_form_tls_address operator are
+ // included; otherwise, they are excluded."
+ //
+ // LLVM extension: We also add DW_OP_GNU_push_tls_address to this list.
+ case DW_TAG_variable:
+ if (isVariableIndexable(Die, DCtx))
+ break;
+ return 0;
+
+ default:
+ break;
+ }
+
+ // Now we know that our Die should be present in the Index. Let's check if
+ // that's the case.
+ unsigned NumErrors = 0;
+ for (StringRef Name : EntryNames) {
+ if (none_of(NI.equal_range(Name), [&Die](const DWARFDebugNames::Entry &E) {
+ return E.getDIESectionOffset() == uint64_t(Die.getOffset());
+ })) {
+ error() << formatv("Name Index @ {0:x}: Entry for DIE @ {1:x} ({2}) with "
+ "name {3} missing.\n",
+ NI.getUnitOffset(), Die.getOffset(), Die.getTag(),
+ Name);
+ ++NumErrors;
+ }
+ }
+ return NumErrors;
+}
+
unsigned DWARFVerifier::verifyDebugNames(const DWARFSection &AccelSection,
const DataExtractor &StrData) {
unsigned NumErrors = 0;
@@ -1171,6 +1306,16 @@
for (uint64_t Name = 1; Name <= NI.getNameCount(); ++Name)
NumErrors += verifyNameIndexEntries(NI, Name, StrData);
+ if (NumErrors > 0)
+ return NumErrors;
+
+ for (const std::unique_ptr<DWARFCompileUnit> &CU : DCtx.compile_units()) {
+ if (const DWARFDebugNames::NameIndex *NI =
+ AccelTable.getCUNameIndex(CU->getOffset())) {
+ for (const DWARFDebugInfoEntry &Die : CU->dies())
+ NumErrors += verifyNameIndexCompleteness(DWARFDie(CU.get(), &Die), *NI);
+ }
+ }
return NumErrors;
}