[llvm] r304846 - Fix uninitialized read.

[Zachary Turner via llvm-commits]

Author: zturner
Date: Tue Jun  6 18:54:23 2017
New Revision: 304846

URL: http://llvm.org/viewvc/llvm-project?rev=304846&view=rev
Log:
Fix uninitialized read.

Modified:
    llvm/trunk/include/llvm/DebugInfo/PDB/Native/DbiStream.h
    llvm/trunk/lib/DebugInfo/PDB/Native/DbiModuleDescriptorBuilder.cpp
    llvm/trunk/lib/DebugInfo/PDB/Native/DbiStream.cpp

Modified: llvm/trunk/include/llvm/DebugInfo/PDB/Native/DbiStream.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/DebugInfo/PDB/Native/DbiStream.h?rev=304846&r1=304845&r2=304846&view=diff
==============================================================================
--- llvm/trunk/include/llvm/DebugInfo/PDB/Native/DbiStream.h (original)
+++ llvm/trunk/include/llvm/DebugInfo/PDB/Native/DbiStream.h Tue Jun  6 18:54:23 2017
@@ -96,7 +96,8 @@ private:
 
   FixedStreamArray<support::ulittle16_t> DbgStreams;
 
-  PdbRaw_DbiSecContribVer SectionContribVersion;
+  PdbRaw_DbiSecContribVer SectionContribVersion =
+      PdbRaw_DbiSecContribVer::DbiSecContribVer60;
   FixedStreamArray<SectionContrib> SectionContribs;
   FixedStreamArray<SectionContrib2> SectionContribs2;
   FixedStreamArray<SecMapEntry> SectionMap;

Modified: llvm/trunk/lib/DebugInfo/PDB/Native/DbiModuleDescriptorBuilder.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/DebugInfo/PDB/Native/DbiModuleDescriptorBuilder.cpp?rev=304846&r1=304845&r2=304846&view=diff
==============================================================================
--- llvm/trunk/lib/DebugInfo/PDB/Native/DbiModuleDescriptorBuilder.cpp (original)
+++ llvm/trunk/lib/DebugInfo/PDB/Native/DbiModuleDescriptorBuilder.cpp Tue Jun  6 18:54:23 2017
@@ -38,12 +38,12 @@ template <> struct BinaryItemTraits<CVSy
 
 static uint32_t calculateDiSymbolStreamSize(uint32_t SymbolByteSize,
                                             uint32_t C13Size) {
-  uint32_t Size = sizeof(uint32_t); // Signature
-  Size += SymbolByteSize;           // Symbol Data
-  Size += 0;                        // TODO: Layout.C11Bytes
-  Size += C13Size;                  // C13 Debug Info Size
-  Size += sizeof(uint32_t);         // GlobalRefs substream size (always 0)
-  Size += 0;                        // GlobalRefs substream bytes
+  uint32_t Size = sizeof(uint32_t);   // Signature
+  Size += alignTo(SymbolByteSize, 4); // Symbol Data
+  Size += 0;                          // TODO: Layout.C11Bytes
+  Size += C13Size;                    // C13 Debug Info Size
+  Size += sizeof(uint32_t);           // GlobalRefs substream size (always 0)
+  Size += 0;                          // GlobalRefs substream bytes
   return Size;
 }
 
@@ -156,6 +156,8 @@ Error DbiModuleDescriptorBuilder::commit
     BinaryStreamRef RecordsRef(Records);
     if (auto EC = SymbolWriter.writeStreamRef(RecordsRef))
       return EC;
+    if (auto EC = SymbolWriter.padToAlignment(4))
+      return EC;
     // TODO: Write C11 Line data
     assert(SymbolWriter.getOffset() % alignOf(CodeViewContainer::Pdb) == 0 &&
            "Invalid debug section alignment!");

Modified: llvm/trunk/lib/DebugInfo/PDB/Native/DbiStream.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/DebugInfo/PDB/Native/DbiStream.cpp?rev=304846&r1=304845&r2=304846&view=diff
==============================================================================
--- llvm/trunk/lib/DebugInfo/PDB/Native/DbiStream.cpp (original)
+++ llvm/trunk/lib/DebugInfo/PDB/Native/DbiStream.cpp Tue Jun  6 18:54:23 2017
@@ -216,10 +216,12 @@ FixedStreamArray<SecMapEntry> DbiStream:
 
 void DbiStream::visitSectionContributions(
     ISectionContribVisitor &Visitor) const {
-  if (SectionContribVersion == DbiSecContribVer60) {
+  if (!SectionContribs.empty()) {
+    assert(SectionContribVersion == DbiSecContribVer60);
     for (auto &SC : SectionContribs)
       Visitor.visit(SC);
-  } else if (SectionContribVersion == DbiSecContribV2) {
+  } else if (!SectionContribs2.empty()) {
+    assert(SectionContribVersion == DbiSecContribV2);
     for (auto &SC : SectionContribs2)
       Visitor.visit(SC);
   }