2 files changed, 25 insertions, 13 deletions

diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index c02b587e3fc..348234da095 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -71,6 +71,15 @@ static bool ConvertToString(ArrayRef<uint64_t> Record, unsigned Idx,
   return false;
 }
 
+ErrorOr<StringRef> BitcodeReader::convertToStringRef(ArrayRef<uint64_t> Record,
+                                                     unsigned Idx) {
+  if (Idx > Record.size())
+    return Error(InvalidRecord);
+
+  return StringRef((char*)&Record[Idx], Record.size() - Idx);
+}
+
+
 static GlobalValue::LinkageTypes GetDecodedLinkage(unsigned Val) {
   switch (Val) {
   default: // Map unknown/new linkages to external
@@ -2116,13 +2125,13 @@ std::error_code BitcodeReader::ParseBitcodeInto(Module *M) {
   }
 }
 
-ErrorOr<std::string> BitcodeReader::parseModuleTriple() {
+ErrorOr<StringRef> BitcodeReader::parseModuleTriple() {
   if (Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
     return Error(InvalidRecord);
 
   SmallVector<uint64_t, 64> Record;
 
-  std::string Triple;
+  StringRef Triple;
   // Read all the records for this module.
   while (1) {
     BitstreamEntry Entry = Stream.advanceSkippingSubblocks();
@@ -2142,10 +2151,10 @@ ErrorOr<std::string> BitcodeReader::parseModuleTriple() {
     switch (Stream.readRecord(Entry.ID, Record)) {
     default: break;  // Default behavior, ignore unknown content.
     case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strchr x N]
-      std::string S;
-      if (ConvertToString(Record, 0, S))
-        return Error(InvalidRecord);
-      Triple = S;
+      ErrorOr<StringRef> S = convertToStringRef(Record, 0);
+      if (std::error_code EC = S.getError())
+        return EC;
+      Triple = S.get();
       break;
     }
     }
@@ -2154,7 +2163,7 @@ ErrorOr<std::string> BitcodeReader::parseModuleTriple() {
   return Triple;
 }
 
-ErrorOr<std::string> BitcodeReader::parseTriple() {
+ErrorOr<StringRef> BitcodeReader::parseTriple() {
   if (std::error_code EC = InitStream())
     return EC;
 
@@ -3469,10 +3478,10 @@ ErrorOr<Module *> llvm::parseBitcodeFile(MemoryBuffer *Buffer,
   return M;
 }
 
-std::string llvm::getBitcodeTargetTriple(MemoryBuffer *Buffer,
-                                         LLVMContext &Context) {
+StringRef llvm::getBitcodeTargetTriple(MemoryBuffer *Buffer,
+                                       LLVMContext &Context) {
   BitcodeReader *R = new BitcodeReader(Buffer, Context);
-  ErrorOr<std::string> Triple = R->parseTriple();
+  ErrorOr<StringRef> Triple = R->parseTriple();
   R->releaseBuffer();
   delete R;
   if (Triple.getError())
diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.h b/llvm/lib/Bitcode/Reader/BitcodeReader.h
index 1d4869a2d5a..e831ea59231 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.h
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.h
@@ -196,6 +196,9 @@ class BitcodeReader : public GVMaterializer {
 
   static const std::error_category &BitcodeErrorCategory();
 
+  static ErrorOr<StringRef> convertToStringRef(ArrayRef<uint64_t> Record,
+                                               unsigned Idx);
+
 public:
   enum ErrorType {
     BitcodeStreamInvalidSize,
@@ -220,7 +223,7 @@ public:
     InvalidValue // Invalid version, inst number, attr number, etc
   };
 
-  std::error_code Error(ErrorType E) {
+  static std::error_code Error(ErrorType E) {
     return std::error_code(E, BitcodeErrorCategory());
   }
 
@@ -252,7 +255,7 @@ public:
 
   /// @brief Cheap mechanism to just extract module triple
   /// @returns true if an error occurred.
-  ErrorOr<std::string> parseTriple();
+  ErrorOr<StringRef> parseTriple();
 
   static uint64_t decodeSignRotatedValue(uint64_t V);
 
@@ -354,7 +357,7 @@ private:
   std::error_code ResolveGlobalAndAliasInits();
   std::error_code ParseMetadata();
   std::error_code ParseMetadataAttachment();
-  ErrorOr<std::string> parseModuleTriple();
+  ErrorOr<StringRef> parseModuleTriple();
   std::error_code ParseUseLists();
   std::error_code InitStream();
   std::error_code InitStreamFromBuffer();