Pass a MemoryBufferRef when we can avoid taking ownership.

The attached patch simplifies a few interfaces that don't need to take
ownership of a buffer.

For example, both parseAssembly and parseBitcodeFile will parse the
entire buffer before returning. There is no need to take ownership.

Using a MemoryBufferRef makes it obvious in the type signature that
there is no ownership transfer.

llvm-svn: 216488

3 files changed, 10 insertions, 9 deletions

diff --git a/llvm/lib/Bitcode/Reader/BitReader.cpp b/llvm/lib/Bitcode/Reader/BitReader.cpp
index b5886c16fa4..e21d29ac374 100644
--- a/llvm/lib/Bitcode/Reader/BitReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitReader.cpp
@@ -31,7 +31,7 @@ LLVMBool LLVMParseBitcodeInContext(LLVMContextRef ContextRef,
                                    LLVMModuleRef *OutModule,
                                    char **OutMessage) {
   ErrorOr<Module *> ModuleOrErr =
-      parseBitcodeFile(unwrap(MemBuf), *unwrap(ContextRef));
+      parseBitcodeFile(unwrap(MemBuf)->getMemBufferRef(), *unwrap(ContextRef));
   if (std::error_code EC = ModuleOrErr.getError()) {
     if (OutMessage)
       *OutMessage = strdup(EC.message().c_str());
diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index e5dfa723b04..8dc0aa32315 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -3564,15 +3564,17 @@ Module *llvm::getStreamedBitcodeModule(const std::string &name,
   return M;
 }
 
-ErrorOr<Module *> llvm::parseBitcodeFile(MemoryBuffer *Buffer,
+ErrorOr<Module *> llvm::parseBitcodeFile(MemoryBufferRef Buffer,
                                          LLVMContext &Context) {
+  std::unique_ptr<MemoryBuffer> Buf = MemoryBuffer::getMemBuffer(Buffer, false);
   ErrorOr<Module *> ModuleOrErr =
-      getLazyBitcodeModuleImpl(Buffer, Context, true);
+      getLazyBitcodeModuleImpl(Buf.get(), Context, true);
   if (!ModuleOrErr)
     return ModuleOrErr;
+  Buf.release(); // The BitcodeReader owns it now.
   Module *M = ModuleOrErr.get();
   // Read in the entire module, and destroy the BitcodeReader.
-  if (std::error_code EC = M->materializeAllPermanently(true)) {
+  if (std::error_code EC = M->materializeAllPermanently()) {
     delete M;
     return EC;
   }
@@ -3583,12 +3585,11 @@ ErrorOr<Module *> llvm::parseBitcodeFile(MemoryBuffer *Buffer,
   return M;
 }
 
-std::string llvm::getBitcodeTargetTriple(MemoryBuffer *Buffer,
+std::string llvm::getBitcodeTargetTriple(MemoryBufferRef Buffer,
                                          LLVMContext &Context) {
-  BitcodeReader *R = new BitcodeReader(Buffer, Context);
+  std::unique_ptr<MemoryBuffer> Buf = MemoryBuffer::getMemBuffer(Buffer, false);
+  auto R = llvm::make_unique<BitcodeReader>(Buf.get(), Context);
   ErrorOr<std::string> Triple = R->parseTriple();
-  R->releaseBuffer();
-  delete R;
   if (Triple.getError())
     return "";
   return Triple.get();
diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.h b/llvm/lib/Bitcode/Reader/BitcodeReader.h
index 6d4e0a2dfe9..c9525661ec1 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.h
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.h
@@ -221,7 +221,7 @@ public:
 
   void FreeState();
 
-  void releaseBuffer() override;
+  void releaseBuffer();
 
   bool isMaterializable(const GlobalValue *GV) const override;
   bool isDematerializable(const GlobalValue *GV) const override;