commit 1f6372c429ce6b85a572c213d53f0ed8d293ff38
author Zachary Turner <zturner@google.com> Thu Jun 16 18:00:28 2016 +0000
committer Zachary Turner <zturner@google.com> Thu Jun 16 18:00:28 2016 +0000
tree a33b3e57a928e737d700244cb33760c425ccf2a6
parent 41315f787374e8542faa18d423784bc6c3545790

[pdb] Change type visitor pattern to be dynamic.

This allows better catching of compiler errors since we can use
the override keyword to verify that methods are actually
overridden.

Also in this patch I've changed from storing a boolean Error
code everywhere to returning an llvm::Error, to propagate richer
error information up the call stack.

Reviewed By: ruiu, rnk
Differential Revision: http://reviews.llvm.org/D21410

llvm-svn: 272926

llvm/lib/DebugInfo/PDB/Raw/TpiStream.cpp

diff --git a/llvm/lib/DebugInfo/PDB/Raw/TpiStream.cpp b/llvm/lib/DebugInfo/PDB/Raw/TpiStream.cpp
index 99e5037..46717f2 100644
--- a/llvm/lib/DebugInfo/PDB/Raw/TpiStream.cpp
+++ b/llvm/lib/DebugInfo/PDB/Raw/TpiStream.cpp
@@ -84,39 +84,44 @@
 }
 
 namespace {
-class TpiHashVerifier : public CVTypeVisitor<TpiHashVerifier> {
+class TpiHashVerifier : public TypeVisitorCallbacks {
 public:
   TpiHashVerifier(FixedStreamArray<support::ulittle32_t> &HashValues,
                   uint32_t NumHashBuckets)
       : HashValues(HashValues), NumHashBuckets(NumHashBuckets) {}
 
-  void visitUdtSourceLine(UdtSourceLineRecord &Rec) { verifySourceLine(Rec); }
-
-  void visitUdtModSourceLine(UdtModSourceLineRecord &Rec) {
-    verifySourceLine(Rec);
+  Error visitUdtSourceLine(UdtSourceLineRecord &Rec) override {
+    return verifySourceLine(Rec);
   }
 
-  void visitClass(ClassRecord &Rec) { verify(Rec); }
-  void visitEnum(EnumRecord &Rec) { verify(Rec); }
-  void visitInterface(ClassRecord &Rec) { verify(Rec); }
-  void visitStruct(ClassRecord &Rec) { verify(Rec); }
-  void visitUnion(UnionRecord &Rec) { verify(Rec); }
+  Error visitUdtModSourceLine(UdtModSourceLineRecord &Rec) override {
+    return verifySourceLine(Rec);
+  }
 
-  void visitTypeEnd(const CVRecord<TypeLeafKind> &Record) { ++Index; }
+  Error visitClass(ClassRecord &Rec) override { return verify(Rec); }
+  Error visitEnum(EnumRecord &Rec) override { return verify(Rec); }
+  Error visitUnion(UnionRecord &Rec) override { return verify(Rec); }
+
+  Error visitTypeEnd(const CVRecord<TypeLeafKind> &Record) override {
+    ++Index;
+    return Error::success();
+  }
 
 private:
-  template <typename T> void verify(T &Rec) {
+  template <typename T> Error verify(T &Rec) {
     uint32_t Hash = getTpiHash(Rec);
     if (Hash && Hash % NumHashBuckets != HashValues[Index])
-      parseError();
+      return make_error<RawError>(raw_error_code::invalid_tpi_hash);
+    return Error::success();
   }
 
-  template <typename T> void verifySourceLine(T &Rec) {
+  template <typename T> Error verifySourceLine(T &Rec) {
     char Buf[4];
     support::endian::write32le(Buf, Rec.getUDT().getIndex());
     uint32_t Hash = hashStringV1(StringRef(Buf, 4));
     if (Hash % NumHashBuckets != HashValues[Index])
-      parseError();
+      return make_error<RawError>(raw_error_code::invalid_tpi_hash);
+    return Error::success();
   }
 
   FixedStreamArray<support::ulittle32_t> HashValues;
@@ -129,11 +134,8 @@
 // Currently we only verify SRC_LINE records.
 Error TpiStream::verifyHashValues() {
   TpiHashVerifier Verifier(HashValues, Header->NumHashBuckets);
-  Verifier.visitTypeStream(TypeRecords);
-  if (Verifier.hadError())
-    return make_error<RawError>(raw_error_code::corrupt_file,
-                                "Corrupt TPI hash table.");
-  return Error::success();
+  CVTypeVisitor Visitor(Verifier);
+  return Visitor.visitTypeStream(TypeRecords);
 }
 
 Error TpiStream::reload() {