Use RequiresNullTerminator to create buffers without a null terminator

instead of copying.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127835 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 8 insertions, 12 deletions

diff --git a/include/llvm/Support/MemoryBuffer.h b/include/llvm/Support/MemoryBuffer.h
index a52dc11cff..3006367a5a 100644
--- a/include/llvm/Support/MemoryBuffer.h
+++ b/include/llvm/Support/MemoryBuffer.h
@@ -81,7 +81,8 @@ public:
   /// getMemBuffer - Open the specified memory range as a MemoryBuffer.  Note
   /// that InputData must be null terminated.
   static MemoryBuffer *getMemBuffer(StringRef InputData,
-                                    StringRef BufferName = "");
+                                    StringRef BufferName = "",
+                                    bool RequiresNullTerminator = true);
 
   /// getMemBufferCopy - Open the specified memory range as a MemoryBuffer,
   /// copying the contents and taking ownership of it.  InputData does not
diff --git a/lib/Support/MemoryBuffer.cpp b/lib/Support/MemoryBuffer.cpp
index 2be0460149..63a1c54a40 100644
--- a/lib/Support/MemoryBuffer.cpp
+++ b/lib/Support/MemoryBuffer.cpp
@@ -92,8 +92,10 @@ public:
 /// getMemBuffer - Open the specified memory range as a MemoryBuffer.  Note
 /// that EndPtr[0] must be a null byte and be accessible!
 MemoryBuffer *MemoryBuffer::getMemBuffer(StringRef InputData,
-                                         StringRef BufferName) {
-  return GetNamedBuffer<MemoryBufferMem>(InputData, BufferName, true);
+                                         StringRef BufferName,
+                                         bool RequiresNullTerminator) {
+  return GetNamedBuffer<MemoryBufferMem>(InputData, BufferName,
+                                         RequiresNullTerminator);
 }
 
 /// getMemBufferCopy - Open the specified memory range as a MemoryBuffer,
diff --git a/tools/lto/LTOModule.cpp b/tools/lto/LTOModule.cpp
index 9de3d5ffce..310e647b1f 100644
--- a/tools/lto/LTOModule.cpp
+++ b/tools/lto/LTOModule.cpp
@@ -114,18 +114,11 @@ LTOModule *LTOModule::makeLTOModule(int fd, const char *path,
   return makeLTOModule(buffer.get(), errMsg);
 }
 
-/// makeBuffer - Create a MemoryBuffer from a memory range.  MemoryBuffer
-/// requires the byte past end of the buffer to be a zero.  We might get lucky
-/// and already be that way, otherwise make a copy.  Also if next byte is on a
-/// different page, don't assume it is readable.
+/// makeBuffer - Create a MemoryBuffer from a memory range.
 MemoryBuffer *LTOModule::makeBuffer(const void *mem, size_t length) {
   const char *startPtr = (char*)mem;
   const char *endPtr = startPtr+length;
-  if (((uintptr_t)endPtr & (sys::Process::GetPageSize()-1)) == 0 ||
-      *endPtr != 0)
-    return MemoryBuffer::getMemBufferCopy(StringRef(startPtr, length));
-
-  return MemoryBuffer::getMemBuffer(StringRef(startPtr, length));
+  return MemoryBuffer::getMemBuffer(StringRef(startPtr, length), "", false);
 }