Copy LLVM bitcode reader to generate a PNaCl wire format reader.

lib/Bitcode/NaCl/Reader/NaClBitcodeReader.cpp

Index: lib/Bitcode/NaCl/Reader/NaClBitcodeReader.cpp
diff --git a/lib/Bitcode/Reader/BitcodeReader.cpp b/lib/Bitcode/NaCl/Reader/NaClBitcodeReader.cpp
similarity index 96%
copy from lib/Bitcode/Reader/BitcodeReader.cpp
copy to lib/Bitcode/NaCl/Reader/NaClBitcodeReader.cpp
index 5878b47376bf93c0cf82e6b09ef7ff356a669c99..0e2c003c73572a07ac84f182e13b6eba8c7c84a5 100644
--- a/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/lib/Bitcode/NaCl/Reader/NaClBitcodeReader.cpp
@@ -1,4 +1,5 @@
-//===- BitcodeReader.cpp - Internal BitcodeReader implementation ----------===//
+//===- NaClBitcodeReader.cpp ----------------------------------------------===//
+//     Internal NaClBitcodeReader implementation
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -7,8 +8,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "llvm/Bitcode/ReaderWriter.h"
-#include "BitcodeReader.h"
+#include "llvm/Bitcode/NaCl/NaClReaderWriter.h"
+#include "NaClBitcodeReader.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/AutoUpgrade.h"
@@ -28,14 +29,14 @@ enum {
   SWITCH_INST_MAGIC = 0x4B5 // May 2012 => 1205 => Hex
 };
 
-void BitcodeReader::materializeForwardReferencedFunctions() {
+void NaClBitcodeReader::materializeForwardReferencedFunctions() {
   while (!BlockAddrFwdRefs.empty()) {
     Function *F = BlockAddrFwdRefs.begin()->first;
     F->Materialize();
   }
 }
 
-void BitcodeReader::FreeState() {
+void NaClBitcodeReader::FreeState() {
   if (BufferOwned)
     delete Buffer;
   Buffer = 0;
@@ -226,7 +227,7 @@ struct OperandTraits<ConstantPlaceHolder> :
 }
 
 
-void BitcodeReaderValueList::AssignValue(Value *V, unsigned Idx) {
+void NaClBitcodeReaderValueList::AssignValue(Value *V, unsigned Idx) {
   if (Idx == size()) {
     push_back(V);
     return;
@@ -255,7 +256,7 @@ void BitcodeReaderValueList::AssignValue(Value *V, unsigned Idx) {
 }
 
 
-Constant *BitcodeReaderValueList::getConstantFwdRef(unsigned Idx,
+Constant *NaClBitcodeReaderValueList::getConstantFwdRef(unsigned Idx,
                                                     Type *Ty) {
   if (Idx >= size())
     resize(Idx + 1);
@@ -271,7 +272,7 @@ Constant *BitcodeReaderValueList::getConstantFwdRef(unsigned Idx,
   return C;
 }
 
-Value *BitcodeReaderValueList::getValueFwdRef(unsigned Idx, Type *Ty) {
+Value *NaClBitcodeReaderValueList::getValueFwdRef(unsigned Idx, Type *Ty) {
   if (Idx >= size())
     resize(Idx + 1);
 
@@ -296,7 +297,7 @@ Value *BitcodeReaderValueList::getValueFwdRef(unsigned Idx, Type *Ty) {
 /// building/reuniquing the constant.  Instead of doing this, we look at all the
 /// uses and rewrite all the place holders at once for any constant that uses
 /// a placeholder.
-void BitcodeReaderValueList::ResolveConstantForwardRefs() {
+void NaClBitcodeReaderValueList::ResolveConstantForwardRefs() {
   // Sort the values by-pointer so that they are efficient to look up with a
   // binary search.
   std::sort(ResolveConstants.begin(), ResolveConstants.end());
@@ -371,7 +372,7 @@ void BitcodeReaderValueList::ResolveConstantForwardRefs() {
   }
 }
 
-void BitcodeReaderMDValueList::AssignValue(Value *V, unsigned Idx) {
+void NaClBitcodeReaderMDValueList::AssignValue(Value *V, unsigned Idx) {
   if (Idx == size()) {
     push_back(V);
     return;
@@ -395,7 +396,7 @@ void BitcodeReaderMDValueList::AssignValue(Value *V, unsigned Idx) {
   MDValuePtrs[Idx] = V;
 }
 
-Value *BitcodeReaderMDValueList::getValueFwdRef(unsigned Idx) {
+Value *NaClBitcodeReaderMDValueList::getValueFwdRef(unsigned Idx) {
   if (Idx >= size())
     resize(Idx + 1);
 
@@ -410,7 +411,7 @@ Value *BitcodeReaderMDValueList::getValueFwdRef(unsigned Idx) {
   return V;
 }
 
-Type *BitcodeReader::getTypeByID(unsigned ID) {
+Type *NaClBitcodeReader::getTypeByID(unsigned ID) {
   // The type table size is always specified correctly.
   if (ID >= TypeList.size())
     return 0;
@@ -448,7 +449,7 @@ static void decodeLLVMAttributesForBitcode(AttrBuilder &B,
                 (EncodedAttrs & 0xffff));
 }
 
-bool BitcodeReader::ParseAttributeBlock() {
+bool NaClBitcodeReader::ParseAttributeBlock() {
   if (Stream.EnterSubBlock(bitc::PARAMATTR_BLOCK_ID))
     return Error("Malformed block record");
 
@@ -506,7 +507,7 @@ bool BitcodeReader::ParseAttributeBlock() {
   }
 }
 
-bool BitcodeReader::ParseAttributeGroupBlock() {
+bool NaClBitcodeReader::ParseAttributeGroupBlock() {
   if (Stream.EnterSubBlock(bitc::PARAMATTR_GROUP_BLOCK_ID))
     return Error("Malformed block record");
 
@@ -581,14 +582,14 @@ bool BitcodeReader::ParseAttributeGroupBlock() {
   }
 }
 
-bool BitcodeReader::ParseTypeTable() {
+bool NaClBitcodeReader::ParseTypeTable() {
   if (Stream.EnterSubBlock(bitc::TYPE_BLOCK_ID_NEW))
     return Error("Malformed block record");
 
   return ParseTypeTableBody();
 }
 
-bool BitcodeReader::ParseTypeTableBody() {
+bool NaClBitcodeReader::ParseTypeTableBody() {
   if (!TypeList.empty())
     return Error("Multiple TYPE_BLOCKs found!");
 
@@ -807,7 +808,7 @@ bool BitcodeReader::ParseTypeTableBody() {
   }
 }
 
-bool BitcodeReader::ParseValueSymbolTable() {
+bool NaClBitcodeReader::ParseValueSymbolTable() {
   if (Stream.EnterSubBlock(bitc::VALUE_SYMTAB_BLOCK_ID))
     return Error("Malformed block record");
 
@@ -861,7 +862,7 @@ bool BitcodeReader::ParseValueSymbolTable() {
   }
 }
 
-bool BitcodeReader::ParseMetadata() {
+bool NaClBitcodeReader::ParseMetadata() {
   unsigned NextMDValueNo = MDValueList.size();
 
   if (Stream.EnterSubBlock(bitc::METADATA_BLOCK_ID))
@@ -961,7 +962,7 @@ bool BitcodeReader::ParseMetadata() {
 
 /// decodeSignRotatedValue - Decode a signed value stored with the sign bit in
 /// the LSB for dense VBR encoding.
-uint64_t BitcodeReader::decodeSignRotatedValue(uint64_t V) {
+uint64_t NaClBitcodeReader::decodeSignRotatedValue(uint64_t V) {
   if ((V & 1) == 0)
     return V >> 1;
   if (V != 1)
@@ -972,7 +973,7 @@ uint64_t BitcodeReader::decodeSignRotatedValue(uint64_t V) {
 
 /// ResolveGlobalAndAliasInits - Resolve all of the initializers for global
 /// values and aliases that we can.
-bool BitcodeReader::ResolveGlobalAndAliasInits() {
+bool NaClBitcodeReader::ResolveGlobalAndAliasInits() {
   std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInitWorklist;
   std::vector<std::pair<GlobalAlias*, unsigned> > AliasInitWorklist;
 
@@ -1011,12 +1012,12 @@ bool BitcodeReader::ResolveGlobalAndAliasInits() {
 static APInt ReadWideAPInt(ArrayRef<uint64_t> Vals, unsigned TypeBits) {
   SmallVector<uint64_t, 8> Words(Vals.size());
   std::transform(Vals.begin(), Vals.end(), Words.begin(),
-                 BitcodeReader::decodeSignRotatedValue);
+                 NaClBitcodeReader::decodeSignRotatedValue);
 
   return APInt(TypeBits, Words);
 }
 
-bool BitcodeReader::ParseConstants() {
+bool NaClBitcodeReader::ParseConstants() {
   if (Stream.EnterSubBlock(bitc::CONSTANTS_BLOCK_ID))
     return Error("Malformed block record");
 
@@ -1411,7 +1412,7 @@ bool BitcodeReader::ParseConstants() {
   }
 }
 
-bool BitcodeReader::ParseUseLists() {
+bool NaClBitcodeReader::ParseUseLists() {
   if (Stream.EnterSubBlock(bitc::USELIST_BLOCK_ID))
     return Error("Malformed block record");
 
@@ -1451,7 +1452,7 @@ bool BitcodeReader::ParseUseLists() {
 /// RememberAndSkipFunctionBody - When we see the block for a function body,
 /// remember where it is and then skip it.  This lets us lazily deserialize the
 /// functions.
-bool BitcodeReader::RememberAndSkipFunctionBody() {
+bool NaClBitcodeReader::RememberAndSkipFunctionBody() {
   // Get the function we are talking about.
   if (FunctionsWithBodies.empty())
     return Error("Insufficient function protos");
@@ -1469,7 +1470,7 @@ bool BitcodeReader::RememberAndSkipFunctionBody() {
   return false;
 }
 
-bool BitcodeReader::GlobalCleanup() {
+bool NaClBitcodeReader::GlobalCleanup() {
   // Patch the initializers for globals and aliases up.
   ResolveGlobalAndAliasInits();
   if (!GlobalInits.empty() || !AliasInits.empty())
@@ -1495,7 +1496,7 @@ bool BitcodeReader::GlobalCleanup() {
   return false;
 }
 
-bool BitcodeReader::ParseModule(bool Resume) {
+bool NaClBitcodeReader::ParseModule(bool Resume) {
   if (Resume)
     Stream.JumpToBit(NextUnreadBit);
   else if (Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
@@ -1790,7 +1791,7 @@ bool BitcodeReader::ParseModule(bool Resume) {
   }
 }
 
-bool BitcodeReader::ParseBitcodeInto(Module *M) {
+bool NaClBitcodeReader::ParseBitcodeInto(Module *M) {
   TheModule = 0;
 
   if (InitStream()) return true;
@@ -1811,7 +1812,7 @@ bool BitcodeReader::ParseBitcodeInto(Module *M) {
       return false;
 
     BitstreamEntry Entry =
-      Stream.advance(BitstreamCursor::AF_DontAutoprocessAbbrevs);
+      Stream.advance(NaClBitstreamCursor::AF_DontAutoprocessAbbrevs);
 
     switch (Entry.Kind) {
     case BitstreamEntry::Error:
@@ -1857,7 +1858,7 @@ bool BitcodeReader::ParseBitcodeInto(Module *M) {
   }
 }
 
-bool BitcodeReader::ParseModuleTriple(std::string &Triple) {
+bool NaClBitcodeReader::ParseModuleTriple(std::string &Triple) {
   if (Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
     return Error("Malformed block record");
 
@@ -1893,7 +1894,7 @@ bool BitcodeReader::ParseModuleTriple(std::string &Triple) {
   }
 }
 
-bool BitcodeReader::ParseTriple(std::string &Triple) {
+bool NaClBitcodeReader::ParseTriple(std::string &Triple) {
   if (InitStream()) return true;
 
   // Sniff for the signature.
@@ -1936,7 +1937,7 @@ bool BitcodeReader::ParseTriple(std::string &Triple) {
 }
 
 /// ParseMetadataAttachment - Parse metadata attachments.
-bool BitcodeReader::ParseMetadataAttachment() {
+bool NaClBitcodeReader::ParseMetadataAttachment() {
   if (Stream.EnterSubBlock(bitc::METADATA_ATTACHMENT_ID))
     return Error("Malformed block record");
 
@@ -1981,7 +1982,7 @@ bool BitcodeReader::ParseMetadataAttachment() {
 }
 
 /// ParseFunctionBody - Lazily parse the specified function body block.
-bool BitcodeReader::ParseFunctionBody(Function *F) {
+bool NaClBitcodeReader::ParseFunctionBody(Function *F) {
   if (Stream.EnterSubBlock(bitc::FUNCTION_BLOCK_ID))
     return Error("Malformed block record");
 
@@ -2863,7 +2864,7 @@ OutOfRecordLoop:
 }
 
 /// FindFunctionInStream - Find the function body in the bitcode stream
-bool BitcodeReader::FindFunctionInStream(Function *F,
+bool NaClBitcodeReader::FindFunctionInStream(Function *F,
        DenseMap<Function*, uint64_t>::iterator DeferredFunctionInfoIterator) {
   while (DeferredFunctionInfoIterator->second == 0) {
     if (Stream.AtEndOfStream())
@@ -2880,7 +2881,7 @@ bool BitcodeReader::FindFunctionInStream(Function *F,
 //===----------------------------------------------------------------------===//
 
 
-bool BitcodeReader::isMaterializable(const GlobalValue *GV) const {
+bool NaClBitcodeReader::isMaterializable(const GlobalValue *GV) const {
   if (const Function *F = dyn_cast<Function>(GV)) {
     return F->isDeclaration() &&
       DeferredFunctionInfo.count(const_cast<Function*>(F));
@@ -2888,7 +2889,7 @@ bool BitcodeReader::isMaterializable(const GlobalValue *GV) const {
   return false;
 }
 
-bool BitcodeReader::Materialize(GlobalValue *GV, std::string *ErrInfo) {
+bool NaClBitcodeReader::Materialize(GlobalValue *GV, std::string *ErrInfo) {
   Function *F = dyn_cast<Function>(GV);
   // If it's not a function or is already material, ignore the request.
   if (!F || !F->isMaterializable()) return false;
@@ -2923,7 +2924,7 @@ bool BitcodeReader::Materialize(GlobalValue *GV, std::string *ErrInfo) {
   return false;
 }
 
-bool BitcodeReader::isDematerializable(const GlobalValue *GV) const {
+bool NaClBitcodeReader::isDematerializable(const GlobalValue *GV) const {
   const Function *F = dyn_cast<Function>(GV);
   if (!F || F->isDeclaration())
     return false;
@@ -2940,7 +2941,7 @@ bool BitcodeReader::isDematerializable(const GlobalValue *GV) const {
   return DeferredFunctionInfo.count(const_cast<Function*>(F));
 }
 
-void BitcodeReader::Dematerialize(GlobalValue *GV) {
+void NaClBitcodeReader::Dematerialize(GlobalValue *GV) {
   Function *F = dyn_cast<Function>(GV);
   // If this function isn't dematerializable, this is a noop.
   if (!F || !isDematerializable(F))
@@ -2953,9 +2954,9 @@ void BitcodeReader::Dematerialize(GlobalValue *GV) {
 }
 
 
-bool BitcodeReader::MaterializeModule(Module *M, std::string *ErrInfo) {
+bool NaClBitcodeReader::MaterializeModule(Module *M, std::string *ErrInfo) {
   assert(M == TheModule &&
-         "Can only Materialize the Module this BitcodeReader is attached to.");
+         "Can only Materialize the Module this NaClBitcodeReader is attached to.");
   // Iterate over the module, deserializing any functions that are still on
   // disk.
   for (Module::iterator F = TheModule->begin(), E = TheModule->end();
@@ -2992,17 +2993,18 @@ bool BitcodeReader::MaterializeModule(Module *M, std::string *ErrInfo) {
   return false;
 }
 
-bool BitcodeReader::InitStream() {
+bool NaClBitcodeReader::InitStream() {
   if (LazyStreamer) return InitLazyStream();
   return InitStreamFromBuffer();
 }
 
-bool BitcodeReader::InitStreamFromBuffer() {
+bool NaClBitcodeReader::InitStreamFromBuffer() {
   const unsigned char *BufPtr = (const unsigned char*)Buffer->getBufferStart();
   const unsigned char *BufEnd = BufPtr+Buffer->getBufferSize();
 
   if (Buffer->getBufferSize() & 3) {
-    if (!isRawBitcode(BufPtr, BufEnd) && !isBitcodeWrapper(BufPtr, BufEnd))
+    if (!isNaClRawBitcode(BufPtr, BufEnd) &&
+        !isNaClBitcodeWrapper(BufPtr, BufEnd))
       return Error("Invalid bitcode signature");
     else
       return Error("Bitcode stream should be a multiple of 4 bytes in length");
@@ -3010,34 +3012,34 @@ bool BitcodeReader::InitStreamFromBuffer() {
 
   // If we have a wrapper header, parse it and ignore the non-bc file contents.
   // The magic number is 0x0B17C0DE stored in little endian.
-  if (isBitcodeWrapper(BufPtr, BufEnd))
-    if (SkipBitcodeWrapperHeader(BufPtr, BufEnd, true))
+  if (isNaClBitcodeWrapper(BufPtr, BufEnd))
+    if (SkipNaClBitcodeWrapperHeader(BufPtr, BufEnd, true))
       return Error("Invalid bitcode wrapper header");
 
-  StreamFile.reset(new BitstreamReader(BufPtr, BufEnd));
+  StreamFile.reset(new NaClBitstreamReader(BufPtr, BufEnd));
   Stream.init(*StreamFile);
 
   return false;
 }
 
-bool BitcodeReader::InitLazyStream() {
-  // Check and strip off the bitcode wrapper; BitstreamReader expects never to
-  // see it.
+bool NaClBitcodeReader::InitLazyStream() {
+  // Check and strip off the bitcode wrapper; NaClBitstreamReader expects
+  // never to see it.
   StreamingMemoryObject *Bytes = new StreamingMemoryObject(LazyStreamer);
-  StreamFile.reset(new BitstreamReader(Bytes));
+  StreamFile.reset(new NaClBitstreamReader(Bytes));
   Stream.init(*StreamFile);
 
   unsigned char buf[16];
   if (Bytes->readBytes(0, 16, buf, NULL) == -1)
     return Error("Bitcode stream must be at least 16 bytes in length");
 
-  if (!isBitcode(buf, buf + 16))
+  if (!isNaClBitcode(buf, buf + 16))
     return Error("Invalid bitcode signature");
 
-  if (isBitcodeWrapper(buf, buf + 4)) {
+  if (isNaClBitcodeWrapper(buf, buf + 4)) {
     const unsigned char *bitcodeStart = buf;
     const unsigned char *bitcodeEnd = buf + 16;
-    SkipBitcodeWrapperHeader(bitcodeStart, bitcodeEnd, false);
+    SkipNaClBitcodeWrapperHeader(bitcodeStart, bitcodeEnd, false);
     Bytes->dropLeadingBytes(bitcodeStart - buf);
     Bytes->setKnownObjectSize(bitcodeEnd - bitcodeStart);
   }
@@ -3048,13 +3050,13 @@ bool BitcodeReader::InitLazyStream() {
 // External interface
 //===----------------------------------------------------------------------===//
 
-/// getLazyBitcodeModule - lazy function-at-a-time loading from a file.
+/// getNaClLazyBitcodeModule - lazy function-at-a-time loading from a file.
 ///
-Module *llvm::getLazyBitcodeModule(MemoryBuffer *Buffer,
-                                   LLVMContext& Context,
-                                   std::string *ErrMsg) {
+Module *llvm::getNaClLazyBitcodeModule(MemoryBuffer *Buffer,
+				       LLVMContext& Context,

[jvoung (off chromium), 2013/04/29 18:02:08]

tabs

[Karl, 2013/04/29 20:44:37]

Done.

+				       std::string *ErrMsg) {
   Module *M = new Module(Buffer->getBufferIdentifier(), Context);
-  BitcodeReader *R = new BitcodeReader(Buffer, Context);
+  NaClBitcodeReader *R = new NaClBitcodeReader(Buffer, Context);
   M->setMaterializer(R);
   if (R->ParseBitcodeInto(M)) {
     if (ErrMsg)
@@ -3063,7 +3065,7 @@ Module *llvm::getLazyBitcodeModule(MemoryBuffer *Buffer,
     delete M;  // Also deletes R.
     return 0;
   }
-  // Have the BitcodeReader dtor delete 'Buffer'.
+  // Have the NaClBitcodeReader dtor delete 'Buffer'.
   R->setBufferOwned(true);
 
   R->materializeForwardReferencedFunctions();
@@ -3074,12 +3076,12 @@ Module *llvm::getLazyBitcodeModule(MemoryBuffer *Buffer,
 }
 
 
-Module *llvm::getStreamedBitcodeModule(const std::string &name,
-                                       DataStreamer *streamer,
-                                       LLVMContext &Context,
-                                       std::string *ErrMsg) {
+Module *llvm::getNaClStreamedBitcodeModule(const std::string &name,
+					   DataStreamer *streamer,

[jvoung (off chromium), 2013/04/29 18:02:08]

tabs!

[Karl, 2013/04/29 20:44:37]

Done.

+					   LLVMContext &Context,
+					   std::string *ErrMsg) {
   Module *M = new Module(name, Context);
-  BitcodeReader *R = new BitcodeReader(streamer, Context);
+  NaClBitcodeReader *R = new NaClBitcodeReader(streamer, Context);
   M->setMaterializer(R);
   if (R->ParseBitcodeInto(M)) {
     if (ErrMsg)
@@ -3096,18 +3098,18 @@ Module *llvm::getStreamedBitcodeModule(const std::string &name,
   return M;
 }
 
-/// ParseBitcodeFile - Read the specified bitcode file, returning the module.
+/// NaClParseBitcodeFile - Read the specified bitcode file, returning the module.
 /// If an error occurs, return null and fill in *ErrMsg if non-null.
-Module *llvm::ParseBitcodeFile(MemoryBuffer *Buffer, LLVMContext& Context,
-                               std::string *ErrMsg){
-  Module *M = getLazyBitcodeModule(Buffer, Context, ErrMsg);
+Module *llvm::NaClParseBitcodeFile(MemoryBuffer *Buffer, LLVMContext& Context,
+				   std::string *ErrMsg){

[jvoung (off chromium), 2013/04/29 18:02:08]

tabs

[Karl, 2013/04/29 20:44:37]

Done.

+  Module *M = getNaClLazyBitcodeModule(Buffer, Context, ErrMsg);
   if (!M) return 0;
 
-  // Don't let the BitcodeReader dtor delete 'Buffer', regardless of whether
+  // Don't let the NaClBitcodeReader dtor delete 'Buffer', regardless of whether
   // there was an error.
-  static_cast<BitcodeReader*>(M->getMaterializer())->setBufferOwned(false);
+  static_cast<NaClBitcodeReader*>(M->getMaterializer())->setBufferOwned(false);
 
-  // Read in the entire module, and destroy the BitcodeReader.
+  // Read in the entire module, and destroy the NaClBitcodeReader.
   if (M->MaterializeAllPermanently(ErrMsg)) {
     delete M;
     return 0;
@@ -3118,19 +3120,3 @@ Module *llvm::ParseBitcodeFile(MemoryBuffer *Buffer, LLVMContext& Context,
 
   return M;
 }
-
-std::string llvm::getBitcodeTargetTriple(MemoryBuffer *Buffer,
-                                         LLVMContext& Context,
-                                         std::string *ErrMsg) {
-  BitcodeReader *R = new BitcodeReader(Buffer, Context);
-  // Don't let the BitcodeReader dtor delete 'Buffer'.
-  R->setBufferOwned(false);
-
-  std::string Triple("");
-  if (R->ParseTriple(Triple))

[jvoung (off chromium), 2013/04/29 18:02:08]

Any reason this is removed?

The NaClBitcodeReader's ParseTriple/ParseModuleTriple methods still exist.  Are
they used by anything else?  Looks like no, only getBitcodeTargetTriple is used
by libLTO.

[Karl, 2013/04/29 20:44:37]

As far as I can tell, only lto uses it, so thought it wasn't necessary. Hence, I
removed it.

[jvoung (off chromium), 2013/04/29 21:49:34]

Would have been a bit cleaner to do that separately, since you could also remove
ParseTriple and ParseModuleTriple?  Then again, as long as the writer writes out
a triple, it seems good to be able to read it back...

-    if (ErrMsg)
-      *ErrMsg = R->getErrorString();
-
-  delete R;
-  return Triple;
-}