[llvm-pdbdump] Add support for dumping symbols from Yaml -> PDB.

Previously we could round-trip type records from PDB -> Yaml ->
PDB, but for symbols we could only go from PDB -> Yaml.  This
completes the round-tripping for symbols as well.

llvm-svn: 297625

1 files changed, 52 insertions, 0 deletions

diff --git a/llvm/lib/DebugInfo/CodeView/SymbolSerializer.cpp b/llvm/lib/DebugInfo/CodeView/SymbolSerializer.cpp
new file mode 100644
index 00000000000..251cc431f52
--- /dev/null
+++ b/llvm/lib/DebugInfo/CodeView/SymbolSerializer.cpp
@@ -0,0 +1,52 @@
+//===- SymbolSerializer.cpp -------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/DebugInfo/CodeView/SymbolSerializer.h"
+
+using namespace llvm;
+using namespace llvm::codeview;
+
+SymbolSerializer::SymbolSerializer(BumpPtrAllocator &Allocator)
+  : Storage(Allocator), RecordBuffer(MaxRecordLength), Stream(RecordBuffer, llvm::support::little),
+  Writer(Stream), Mapping(Writer) { }
+
+Error SymbolSerializer::visitSymbolBegin(CVSymbol &Record) {
+  assert(!CurrentSymbol.hasValue() && "Already in a symbol mapping!");
+
+  Writer.setOffset(0);
+
+  if (auto EC = writeRecordPrefix(Record.kind()))
+    return EC;
+
+  CurrentSymbol = Record.kind();
+  if (auto EC = Mapping.visitSymbolBegin(Record))
+    return EC;
+
+  return Error::success();
+}
+
+Error SymbolSerializer::visitSymbolEnd(CVSymbol &Record) {
+  assert(CurrentSymbol.hasValue() && "Not in a symbol mapping!");
+
+  if (auto EC = Mapping.visitSymbolEnd(Record))
+    return EC;
+
+  uint32_t RecordEnd = Writer.getOffset();
+  uint16_t Length = RecordEnd - 2;
+  Writer.setOffset(0);
+  if (auto EC = Writer.writeInteger(Length))
+    return EC;
+
+  uint8_t *StableStorage = Storage.Allocate<uint8_t>(RecordEnd);
+  ::memcpy(StableStorage, &RecordBuffer[0], RecordEnd);
+  Record.RecordData = ArrayRef<uint8_t>(StableStorage, RecordEnd);
+  CurrentSymbol.reset();
+
+  return Error::success();
+}