Switch the bitcode reader interface to take a MemoryBuffer instead of knowing
anything about disk I/O itself. This greatly simplifies its interface -
eliminating the need for the ReaderWrappers.cpp file.
This adds a new option to llvm-dis (-bitcode) which instructs it to read
the input file as bitcode. Until/unless the bytecode reader is taught to
read from MemoryBuffer, there is no way to handle stdin reading without it.
I don't plan to switch the bytecode reader over, I'd rather delete it :),
so the option will stay around temporarily.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36554 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Bitcode/Reader/BitcodeReader.cpp b/lib/Bitcode/Reader/BitcodeReader.cpp
index 2a6de41..6157a5d 100644
--- a/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -11,6 +11,7 @@
//
//===----------------------------------------------------------------------===//
+#include "llvm/Bitcode/ReaderWriter.h"
#include "BitcodeReader.h"
#include "llvm/Bitcode/BitstreamReader.h"
#include "llvm/Constants.h"
@@ -18,8 +19,14 @@
#include "llvm/Module.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/Support/MathExtras.h"
+#include "llvm/Support/MemoryBuffer.h"
using namespace llvm;
+BitcodeReader::~BitcodeReader() {
+ delete Buffer;
+}
+
+
/// ConvertToString - Convert a string from a record into an std::string, return
/// true on failure.
template<typename StrTy>
@@ -852,14 +859,14 @@
}
-bool BitcodeReader::ParseBitcode(unsigned char *Buf, unsigned Length,
- const std::string &ModuleID) {
+bool BitcodeReader::ParseBitcode() {
TheModule = 0;
- if (Length & 3)
+ if (Buffer->getBufferSize() & 3)
return Error("Bitcode stream should be a multiple of 4 bytes in length");
- BitstreamReader Stream(Buf, Buf+Length);
+ unsigned char *BufPtr = (unsigned char *)Buffer->getBufferStart();
+ BitstreamReader Stream(BufPtr, BufPtr+Buffer->getBufferSize());
// Sniff for the signature.
if (Stream.Read(8) != 'B' ||
@@ -882,7 +889,7 @@
// We only know the MODULE subblock ID.
if (BlockID == bitc::MODULE_BLOCK_ID) {
- if (ParseModule(Stream, ModuleID))
+ if (ParseModule(Stream, Buffer->getBufferIdentifier()))
return true;
} else if (Stream.SkipBlock()) {
return Error("Malformed block record");
@@ -891,3 +898,41 @@
return false;
}
+
+//===----------------------------------------------------------------------===//
+// External interface
+//===----------------------------------------------------------------------===//
+
+/// getBitcodeModuleProvider - lazy function-at-a-time loading from a file.
+///
+ModuleProvider *llvm::getBitcodeModuleProvider(MemoryBuffer *Buffer,
+ std::string *ErrMsg) {
+ BitcodeReader *R = new BitcodeReader(Buffer);
+ if (R->ParseBitcode()) {
+ if (ErrMsg)
+ *ErrMsg = R->getErrorString();
+
+ // Don't let the BitcodeReader dtor delete 'Buffer'.
+ R->releaseMemoryBuffer();
+ delete R;
+ return 0;
+ }
+ return R;
+}
+
+/// ParseBitcodeFile - 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, std::string *ErrMsg){
+ BitcodeReader *R;
+ R = static_cast<BitcodeReader*>(getBitcodeModuleProvider(Buffer, ErrMsg));
+ if (!R) return 0;
+
+ // Read the whole module, get a pointer to it, tell ModuleProvider not to
+ // delete it when its dtor is run.
+ Module *M = R->releaseModule(ErrMsg);
+
+ // Don't let the BitcodeReader dtor delete 'Buffer'.
+ R->releaseMemoryBuffer();
+ delete R;
+ return M;
+}