1 files changed, 152 insertions, 0 deletions
diff --git a/tools/llvm-pdbutil/Analyze.cpp b/tools/llvm-pdbutil/Analyze.cpp
new file mode 100644
index 000000000000..b503cdcbf1ea
--- /dev/null
+++ b/tools/llvm-pdbutil/Analyze.cpp
@@ -0,0 +1,152 @@
+//===- Analyze.cpp - PDB analysis functions ---------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Analyze.h"
+
+#include "llvm/ADT/DenseSet.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/DebugInfo/CodeView/CVTypeVisitor.h"
+#include "llvm/DebugInfo/CodeView/TypeDatabase.h"
+#include "llvm/DebugInfo/CodeView/TypeDatabaseVisitor.h"
+#include "llvm/DebugInfo/CodeView/TypeRecord.h"
+#include "llvm/DebugInfo/CodeView/TypeVisitorCallbackPipeline.h"
+#include "llvm/DebugInfo/CodeView/TypeVisitorCallbacks.h"
+#include "llvm/DebugInfo/PDB/Native/PDBFile.h"
+#include "llvm/DebugInfo/PDB/Native/RawError.h"
+#include "llvm/DebugInfo/PDB/Native/TpiStream.h"
+
+#include "llvm/Support/FormatVariadic.h"
+#include "llvm/Support/raw_ostream.h"
+
+#include <list>
+
+using namespace llvm;
+using namespace llvm::codeview;
+using namespace llvm::pdb;
+
+static StringRef getLeafTypeName(TypeLeafKind LT) {
+  switch (LT) {
+#define TYPE_RECORD(ename, value, name)                                        \
+  case ename:                                                                  \
+    return #name;
+#include "llvm/DebugInfo/CodeView/CodeViewTypes.def"
+  default:
+    break;
+  }
+  return "UnknownLeaf";
+}
+
+namespace {
+struct HashLookupVisitor : public TypeVisitorCallbacks {
+  struct Entry {
+    TypeIndex TI;
+    CVType Record;
+  };
+
+  explicit HashLookupVisitor(TpiStream &Tpi) : Tpi(Tpi) {}
+
+  Error visitTypeBegin(CVType &Record) override {
+    uint32_t H = Tpi.getHashValues()[I];
+    Record.Hash = H;
+    TypeIndex TI(I + TypeIndex::FirstNonSimpleIndex);
+    Lookup[H].push_back(Entry{TI, Record});
+    ++I;
+    return Error::success();
+  }
+
+  uint32_t I = 0;
+  DenseMap<uint32_t, std::list<Entry>> Lookup;
+  TpiStream &Tpi;
+};
+}
+
+AnalysisStyle::AnalysisStyle(PDBFile &File) : File(File) {}
+
+Error AnalysisStyle::dump() {
+  auto Tpi = File.getPDBTpiStream();
+  if (!Tpi)
+    return Tpi.takeError();
+
+  TypeDatabase TypeDB(Tpi->getNumTypeRecords());
+  TypeDatabaseVisitor DBV(TypeDB);
+  TypeVisitorCallbackPipeline Pipeline;
+  HashLookupVisitor Hasher(*Tpi);
+  // Add them to the database
+  Pipeline.addCallbackToPipeline(DBV);
+  // Store their hash values
+  Pipeline.addCallbackToPipeline(Hasher);
+
+  if (auto EC = codeview::visitTypeStream(Tpi->typeArray(), Pipeline))
+    return EC;
+
+  auto &Adjusters = Tpi->getHashAdjusters();
+  DenseSet<uint32_t> AdjusterSet;
+  for (const auto &Adj : Adjusters) {
+    assert(AdjusterSet.find(Adj.second) == AdjusterSet.end());
+    AdjusterSet.insert(Adj.second);
+  }
+
+  uint32_t Count = 0;
+  outs() << "Searching for hash collisions\n";
+  for (const auto &H : Hasher.Lookup) {
+    if (H.second.size() <= 1)
+      continue;
+    ++Count;
+    outs() << formatv("Hash: {0}, Count: {1} records\n", H.first,
+                      H.second.size());
+    for (const auto &R : H.second) {
+      auto Iter = AdjusterSet.find(R.TI.getIndex());
+      StringRef Prefix;
+      if (Iter != AdjusterSet.end()) {
+        Prefix = "[HEAD]";
+        AdjusterSet.erase(Iter);
+      }
+      StringRef LeafName = getLeafTypeName(R.Record.Type);
+      uint32_t TI = R.TI.getIndex();
+      StringRef TypeName = TypeDB.getTypeName(R.TI);
+      outs() << formatv("{0,-6} {1} ({2:x}) {3}\n", Prefix, LeafName, TI,
+                        TypeName);
+    }
+  }
+
+  outs() << "\n";
+  outs() << "Dumping hash adjustment chains\n";
+  for (const auto &A : Tpi->getHashAdjusters()) {
+    TypeIndex TI(A.second);
+    StringRef TypeName = TypeDB.getTypeName(TI);
+    const CVType &HeadRecord = TypeDB.getTypeRecord(TI);
+    assert(HeadRecord.Hash.hasValue());
+
+    auto CollisionsIter = Hasher.Lookup.find(*HeadRecord.Hash);
+    if (CollisionsIter == Hasher.Lookup.end())
+      continue;
+
+    const auto &Collisions = CollisionsIter->second;
+    outs() << TypeName << "\n";
+    outs() << formatv("    [HEAD] {0:x} {1} {2}\n", A.second,
+                      getLeafTypeName(HeadRecord.Type), TypeName);
+    for (const auto &Chain : Collisions) {
+      if (Chain.TI == TI)
+        continue;
+      const CVType &TailRecord = TypeDB.getTypeRecord(Chain.TI);
+      outs() << formatv("           {0:x} {1} {2}\n", Chain.TI.getIndex(),
+                        getLeafTypeName(TailRecord.Type),
+                        TypeDB.getTypeName(Chain.TI));
+    }
+  }
+  outs() << formatv("There are {0} orphaned hash adjusters\n",
+                    AdjusterSet.size());
+  for (const auto &Adj : AdjusterSet) {
+    outs() << formatv("    {0}\n", Adj);
+  }
+
+  uint32_t DistinctHashValues = Hasher.Lookup.size();
+  outs() << formatv("{0}/{1} hash collisions", Count, DistinctHashValues);
+  return Error::success();
+}