Update getLazyBitcodeModule to use ErrorOr for error handling.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199125 91177308-0d34-0410-b5e6-96231b3b80d8

Author: espindola

include/llvm/Bitcode/ReaderWriter.h

@@ -14,6 +14,7 @@
 #ifndef LLVM_BITCODE_READERWRITER_H
 #define LLVM_BITCODE_READERWRITER_H
 
+#include "llvm/Support/ErrorOr.h"
 #include <string>
 
 namespace llvm {
@@ -25,14 +26,11 @@ namespace llvm {
   class ModulePass;
   class raw_ostream;
 
-  /// getLazyBitcodeModule - Read the header of the specified bitcode buffer
-  /// and prepare for lazy deserialization of function bodies.  If successful,
-  /// this takes ownership of 'buffer' and returns a non-null pointer.  On
-  /// error, this returns null, *does not* take ownership of Buffer, and fills
-  /// in *ErrMsg with an error description if ErrMsg is non-null.
-  Module *getLazyBitcodeModule(MemoryBuffer *Buffer,
-                               LLVMContext &Context,
-                               std::string *ErrMsg = 0);
+  /// Read the header of the specified bitcode buffer and prepare for lazy
+  /// deserialization of function bodies.  If successful, this takes ownership
+  /// of 'buffer. On error, this *does not* take ownership of Buffer.
+  ErrorOr<Module *> getLazyBitcodeModule(MemoryBuffer *Buffer,
+                                         LLVMContext &Context);
 
   /// getStreamedBitcodeModule - Read the header of the specified stream
   /// and prepare for lazy deserialization and streaming of function bodies.

lib/Bitcode/Reader/BitReader.cpp

@@ -51,15 +51,18 @@ LLVMBool LLVMGetBitcodeModuleInContext(LLVMContextRef ContextRef,
                                        LLVMModuleRef *OutM,
                                        char **OutMessage) {
   std::string Message;
+  ErrorOr<Module *> ModuleOrErr =
+      getLazyBitcodeModule(unwrap(MemBuf), *unwrap(ContextRef));
 
-  *OutM = wrap(getLazyBitcodeModule(unwrap(MemBuf), *unwrap(ContextRef),
-                                    &Message));
-  if (!*OutM) {
+  if (error_code EC = ModuleOrErr.getError()) {
+    *OutM = wrap((Module *)NULL);
     if (OutMessage)
-      *OutMessage = strdup(Message.c_str());
+      *OutMessage = strdup(EC.message().c_str());
     return 1;
   }
 
+  *OutM = wrap(ModuleOrErr.get());
+
   return 0;
 
 }

lib/Bitcode/Reader/BitcodeReader.cpp

@@ -3274,18 +3274,14 @@ const error_category &BitcodeReader::BitcodeErrorCategory() {
 
 /// getLazyBitcodeModule - lazy function-at-a-time loading from a file.
 ///
-Module *llvm::getLazyBitcodeModule(MemoryBuffer *Buffer,
-                                   LLVMContext& Context,
-                                   std::string *ErrMsg) {
+ErrorOr<Module *> llvm::getLazyBitcodeModule(MemoryBuffer *Buffer,
+                                             LLVMContext &Context) {
   Module *M = new Module(Buffer->getBufferIdentifier(), Context);
   BitcodeReader *R = new BitcodeReader(Buffer, Context);
   M->setMaterializer(R);
   if (error_code EC = R->ParseBitcodeInto(M)) {
-    if (ErrMsg)
-      *ErrMsg = EC.message();
-
     delete M;  // Also deletes R.
-    return 0;
+    return EC;
   }
   // Have the BitcodeReader dtor delete 'Buffer'.
   R->setBufferOwned(true);
@@ -3317,8 +3313,13 @@ Module *llvm::getStreamedBitcodeModule(const std::string &name,
 /// 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);
-  if (!M) return 0;
+  ErrorOr<Module *> ModuleOrErr = getLazyBitcodeModule(Buffer, Context);
+  if (error_code EC = ModuleOrErr.getError()) {
+    if (ErrMsg)
+      *ErrMsg = EC.message();
+    return 0;
+  }
+  Module *M = ModuleOrErr.get();
 
   // Don't let the BitcodeReader dtor delete 'Buffer', regardless of whether
   // there was an error.

lib/IRReader/IRReader.cpp

@@ -36,15 +36,16 @@ Module *llvm::getLazyIRModule(MemoryBuffer *Buffer, SMDiagnostic &Err,
   if (isBitcode((const unsigned char *)Buffer->getBufferStart(),
                 (const unsigned char *)Buffer->getBufferEnd())) {
     std::string ErrMsg;
-    Module *M = getLazyBitcodeModule(Buffer, Context, &ErrMsg);
-    if (M == 0) {
+    ErrorOr<Module *> ModuleOrErr = getLazyBitcodeModule(Buffer, Context);
+    if (error_code EC = ModuleOrErr.getError()) {
       Err = SMDiagnostic(Buffer->getBufferIdentifier(), SourceMgr::DK_Error,
-                         ErrMsg);
+                         EC.message());
       // ParseBitcodeFile does not take ownership of the Buffer in the
       // case of an error.
       delete Buffer;
+      return NULL;
     }
-    return M;
+    return ModuleOrErr.get();
   }
 
   return ParseAssembly(Buffer, 0, Err, Context);

lib/LTO/LTOModule.cpp

@@ -135,12 +135,14 @@ LTOModule *LTOModule::makeLTOModule(MemoryBuffer *buffer,
                                     TargetOptions options,
                                     std::string &errMsg) {
   // parse bitcode buffer
-  OwningPtr<Module> m(getLazyBitcodeModule(buffer, getGlobalContext(),
-                                           &errMsg));
-  if (!m) {
+  ErrorOr<Module *> ModuleOrErr =
+      getLazyBitcodeModule(buffer, getGlobalContext());
+  if (error_code EC = ModuleOrErr.getError()) {
+    errMsg = EC.message();
     delete buffer;
     return NULL;
   }
+  OwningPtr<Module> m(ModuleOrErr.get());
 
   std::string TripleStr = m->getTargetTriple();
   if (TripleStr.empty())

unittests/Bitcode/BitReaderTest.cpp

@@ -54,8 +54,9 @@ TEST(BitReaderTest, MaterializeFunctionsForBlockAddr) { // PR11677
   SmallString<1024> Mem;
   writeModuleToBuffer(Mem);
   MemoryBuffer *Buffer = MemoryBuffer::getMemBuffer(Mem.str(), "test", false);
-  std::string errMsg;
-  OwningPtr<Module> m(getLazyBitcodeModule(Buffer, getGlobalContext(), &errMsg));
+  ErrorOr<Module *> ModuleOrErr =
+      getLazyBitcodeModule(Buffer, getGlobalContext());
+  OwningPtr<Module> m(ModuleOrErr.get());
   PassManager passes;
   passes.add(createVerifierPass());
   passes.run(*m);

unittests/ExecutionEngine/JIT/JITTest.cpp

@@ -631,13 +631,14 @@ ExecutionEngine *getJITFromBitcode(
   // c_str() is null-terminated like MemoryBuffer::getMemBuffer requires.
   MemoryBuffer *BitcodeBuffer =
     MemoryBuffer::getMemBuffer(Bitcode, "Bitcode for test");
-  std::string errMsg;
-  M = getLazyBitcodeModule(BitcodeBuffer, Context, &errMsg);
-  if (M == NULL) {
-    ADD_FAILURE() << errMsg;
+  ErrorOr<Module*> ModuleOrErr = getLazyBitcodeModule(BitcodeBuffer, Context);
+  if (error_code EC = ModuleOrErr.getError()) {
+    ADD_FAILURE() << EC.message();
     delete BitcodeBuffer;
     return NULL;
   }
+  M = ModuleOrErr.get();
+  std::string errMsg;
   ExecutionEngine *TheJIT = EngineBuilder(M)
     .setEngineKind(EngineKind::JIT)
     .setErrorStr(&errMsg)