commit 7c6b19f49bc5340c30d5c1f184f82dfcebd4388d
author Zachary Turner <zturner@google.com> Tue Dec 04 21:48:46 2018 +0000
committer Zachary Turner <zturner@google.com> Tue Dec 04 21:48:46 2018 +0000
tree 82b228e895437678e29a8ae6f537d46541c0c6c5
parent cb6788d7b35b3285458a072e74647b17803259cc

[PDB] Emit S_UDT records in LLD.

Previously these were dropped.  We now understand them sufficiently
well to start emitting them.  From the debugger's perspective, this
now enables us to have debug info about typedefs (both global and
function-locally scoped)

Differential Revision: https://reviews.llvm.org/D55228

llvm-svn: 348306

llvm/lib/DebugInfo/PDB/Native/GSIStreamBuilder.cpp

diff --git a/llvm/lib/DebugInfo/PDB/Native/GSIStreamBuilder.cpp b/llvm/lib/DebugInfo/PDB/Native/GSIStreamBuilder.cpp
index b40ae8e..57da700 100644
--- a/llvm/lib/DebugInfo/PDB/Native/GSIStreamBuilder.cpp
+++ b/llvm/lib/DebugInfo/PDB/Native/GSIStreamBuilder.cpp
@@ -9,6 +9,7 @@
 
 #include "llvm/DebugInfo/PDB/Native/GSIStreamBuilder.h"
 
+#include "llvm/ADT/DenseSet.h"
 #include "llvm/DebugInfo/CodeView/RecordName.h"
 #include "llvm/DebugInfo/CodeView/SymbolDeserializer.h"
 #include "llvm/DebugInfo/CodeView/SymbolRecord.h"
@@ -20,6 +21,7 @@
 #include "llvm/DebugInfo/PDB/Native/Hash.h"
 #include "llvm/Support/BinaryItemStream.h"
 #include "llvm/Support/BinaryStreamWriter.h"
+#include "llvm/Support/xxhash.h"
 #include <algorithm>
 #include <vector>
 
@@ -29,8 +31,27 @@
 using namespace llvm::codeview;
 
 struct llvm::pdb::GSIHashStreamBuilder {
+  struct UdtDenseMapInfo {
+    static inline CVSymbol getEmptyKey() {
+      static CVSymbol Empty;
+      return Empty;
+    }
+    static inline CVSymbol getTombstoneKey() {
+      static CVSymbol Tombstone(static_cast<SymbolKind>(-1),
+                                ArrayRef<uint8_t>());
+      return Tombstone;
+    }
+    static unsigned getHashValue(const CVSymbol &Val) {
+      return xxHash64(Val.RecordData);
+    }
+    static bool isEqual(const CVSymbol &LHS, const CVSymbol &RHS) {
+      return LHS.RecordData == RHS.RecordData;
+    }
+  };
+
   std::vector<CVSymbol> Records;
   uint32_t StreamIndex;
+  llvm::DenseSet<CVSymbol, UdtDenseMapInfo> UdtHashes;
   std::vector<PSHashRecord> HashRecords;
   std::array<support::ulittle32_t, (IPHR_HASH + 32) / 32> HashBitmap;
   std::vector<support::ulittle32_t> HashBuckets;
@@ -42,10 +63,18 @@
 
   template <typename T> void addSymbol(const T &Symbol, MSFBuilder &Msf) {
     T Copy(Symbol);
-    Records.push_back(SymbolSerializer::writeOneSymbol(Copy, Msf.getAllocator(),
-                                                       CodeViewContainer::Pdb));
+    addSymbol(SymbolSerializer::writeOneSymbol(Copy, Msf.getAllocator(),
+                                               CodeViewContainer::Pdb));
   }
-  void addSymbol(const CVSymbol &Symbol) { Records.push_back(Symbol); }
+  void addSymbol(const CVSymbol &Symbol) {
+    if (Symbol.kind() == S_UDT) {
+      auto Iter = UdtHashes.insert(Symbol);
+      if (!Iter.second)
+        return;
+    }
+
+    Records.push_back(Symbol);
+  }
 };
 
 uint32_t GSIHashStreamBuilder::calculateSerializedLength() const {
@@ -272,10 +301,6 @@
   GSH->addSymbol(Sym, Msf);
 }
 
-void GSIStreamBuilder::addGlobalSymbol(const UDTSym &Sym) {
-  GSH->addSymbol(Sym, Msf);
-}
-
 void GSIStreamBuilder::addGlobalSymbol(const codeview::CVSymbol &Sym) {
   GSH->addSymbol(Sym);
 }