commit 70d35e102ef8dbba10e2db84ea2dcbe95bbbfd38
author Spyridoula Gravani <sgravani@apple.com> Mon Jul 31 18:01:16 2017 +0000
committer Spyridoula Gravani <sgravani@apple.com> Mon Jul 31 18:01:16 2017 +0000
tree 690bb0dee93523750ca98e553d0957746d277098
parent 91c6330c96aaf14605f7d520af72c62c1284ae45

[DWARF] Added verification check for tags in accelerator tables. This patch verifies that the atom tag is actually the same with the tag of the DIE that we retrieve from the table.

Differential Revision: https://reviews.llvm.org/D35963

llvm-svn: 309596

llvm/lib/DebugInfo/DWARF/DWARFAcceleratorTable.cpp

diff --git a/llvm/lib/DebugInfo/DWARF/DWARFAcceleratorTable.cpp b/llvm/lib/DebugInfo/DWARF/DWARFAcceleratorTable.cpp
index 9ae7c9a..f17b00e 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFAcceleratorTable.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFAcceleratorTable.cpp
@@ -73,6 +73,8 @@
     DWARFFormValue FormValue(Atom.second);
     switch (Atom.first) {
     case dwarf::DW_ATOM_die_offset:
+    case dwarf::DW_ATOM_die_tag:
+    case dwarf::DW_ATOM_type_flags:
       if ((!FormValue.isFormClass(DWARFFormValue::FC_Constant) &&
            !FormValue.isFormClass(DWARFFormValue::FC_Flag)) ||
           FormValue.getForm() == dwarf::DW_FORM_sdata)
@@ -84,8 +86,10 @@
   return true;
 }
 
-uint32_t DWARFAcceleratorTable::readAtoms(uint32_t &HashDataOffset) {
+std::pair<uint32_t, dwarf::Tag>
+DWARFAcceleratorTable::readAtoms(uint32_t &HashDataOffset) {
   uint32_t DieOffset = dwarf::DW_INVALID_OFFSET;
+  dwarf::Tag DieTag = dwarf::DW_TAG_null;
 
   for (auto Atom : getAtomsDesc()) {
     DWARFFormValue FormValue(Atom.second);
@@ -94,11 +98,14 @@
     case dwarf::DW_ATOM_die_offset:
       DieOffset = *FormValue.getAsUnsignedConstant();
       break;
+    case dwarf::DW_ATOM_die_tag:
+      DieTag = (dwarf::Tag)*FormValue.getAsUnsignedConstant();
+      break;
     default:
       break;
     }
   }
-  return DieOffset;
+  return {DieOffset, DieTag};
 }
 
 LLVM_DUMP_METHOD void DWARFAcceleratorTable::dump(raw_ostream &OS) const {

llvm/lib/DebugInfo/DWARF/DWARFVerifier.cpp

diff --git a/llvm/lib/DebugInfo/DWARF/DWARFVerifier.cpp b/llvm/lib/DebugInfo/DWARF/DWARFVerifier.cpp
index c5dc723..577fce9 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFVerifier.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFVerifier.cpp
@@ -525,15 +525,16 @@
     uint32_t StrpOffset;
     uint32_t StringOffset;
     uint32_t StringCount = 0;
-    uint32_t DieOffset = dwarf::DW_INVALID_OFFSET;
-
+    unsigned Offset;
+    unsigned Tag;
     while ((StrpOffset = AccelSectionData.getU32(&HashDataOffset)) != 0) {
       const uint32_t NumHashDataObjects =
           AccelSectionData.getU32(&HashDataOffset);
       for (uint32_t HashDataIdx = 0; HashDataIdx < NumHashDataObjects;
            ++HashDataIdx) {
-        DieOffset = AccelTable.readAtoms(HashDataOffset);
-        if (!DCtx.getDIEForOffset(DieOffset)) {
+        std::tie(Offset, Tag) = AccelTable.readAtoms(HashDataOffset);
+        auto Die = DCtx.getDIEForOffset(Offset);
+        if (!Die) {
           const uint32_t BucketIdx =
               NumBuckets ? (Hash % NumBuckets) : UINT32_MAX;
           StringOffset = StrpOffset;
@@ -546,9 +547,17 @@
               "Str[%u] = 0x%08x "
               "DIE[%d] = 0x%08x is not a valid DIE offset for \"%s\".\n",
               SectionName, BucketIdx, HashIdx, Hash, StringCount, StrpOffset,
-              HashDataIdx, DieOffset, Name);
+              HashDataIdx, Offset, Name);
 
           ++NumErrors;
+          continue;
+        }
+        if ((Tag != dwarf::DW_TAG_null) && (Die.getTag() != Tag)) {
+          OS << "\terror: Tag " << dwarf::TagString(Tag)
+             << " in accelerator table does not match Tag "
+             << dwarf::TagString(Die.getTag()) << " of DIE[" << HashDataIdx
+             << "].\n";
+          ++NumErrors;
         }
       }
       ++StringCount;