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Diffstat (limited to 'include/llvm/Bitcode/ReaderWriter.h')
-rw-r--r-- | include/llvm/Bitcode/ReaderWriter.h | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/include/llvm/Bitcode/ReaderWriter.h b/include/llvm/Bitcode/ReaderWriter.h new file mode 100644 index 0000000..abdd5d3 --- /dev/null +++ b/include/llvm/Bitcode/ReaderWriter.h @@ -0,0 +1,113 @@ +//===-- llvm/Bitcode/ReaderWriter.h - Bitcode reader/writers ----*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This header defines interfaces to read and write LLVM bitcode files/streams. +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_BITCODE_H +#define LLVM_BITCODE_H + +#include <iosfwd> +#include <string> + +namespace llvm { + class Module; + class ModuleProvider; + class MemoryBuffer; + class ModulePass; + class BitstreamWriter; + class raw_ostream; + + /// getBitcodeModuleProvider - 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. + ModuleProvider *getBitcodeModuleProvider(MemoryBuffer *Buffer, + std::string *ErrMsg = 0); + + /// ParseBitcodeFile - Read the specified bitcode file, returning the module. + /// If an error occurs, this returns null and fills in *ErrMsg if it is + /// non-null. This method *never* takes ownership of Buffer. + Module *ParseBitcodeFile(MemoryBuffer *Buffer, std::string *ErrMsg = 0); + + /// WriteBitcodeToFile - Write the specified module to the specified output + /// stream. + void WriteBitcodeToFile(const Module *M, std::ostream &Out); + + /// WriteBitcodeToFile - Write the specified module to the specified + /// raw output stream. + void WriteBitcodeToFile(const Module *M, raw_ostream &Out); + + /// WriteBitcodeToStream - Write the specified module to the specified + /// raw output stream. + void WriteBitcodeToStream(const Module *M, BitstreamWriter &Stream); + + /// CreateBitcodeWriterPass - Create and return a pass that writes the module + /// to the specified ostream. + ModulePass *CreateBitcodeWriterPass(std::ostream &Str); + + /// createBitcodeWriterPass - Create and return a pass that writes the module + /// to the specified ostream. + ModulePass *createBitcodeWriterPass(raw_ostream &Str); + + + /// isBitcodeWrapper - Return true fi this is a wrapper for LLVM IR bitcode + /// files. + static bool inline isBitcodeWrapper(unsigned char *BufPtr, + unsigned char *BufEnd) { + return (BufPtr != BufEnd && BufPtr[0] == 0xDE && BufPtr[1] == 0xC0 && + BufPtr[2] == 0x17 && BufPtr[3] == 0x0B); + } + + /// SkipBitcodeWrapperHeader - Some systems wrap bc files with a special + /// header for padding or other reasons. The format of this header is: + /// + /// struct bc_header { + /// uint32_t Magic; // 0x0B17C0DE + /// uint32_t Version; // Version, currently always 0. + /// uint32_t BitcodeOffset; // Offset to traditional bitcode file. + /// uint32_t BitcodeSize; // Size of traditional bitcode file. + /// ... potentially other gunk ... + /// }; + /// + /// This function is called when we find a file with a matching magic number. + /// In this case, skip down to the subsection of the file that is actually a + /// BC file. + static inline bool SkipBitcodeWrapperHeader(unsigned char *&BufPtr, + unsigned char *&BufEnd) { + enum { + KnownHeaderSize = 4*4, // Size of header we read. + OffsetField = 2*4, // Offset in bytes to Offset field. + SizeField = 3*4 // Offset in bytes to Size field. + }; + + // Must contain the header! + if (BufEnd-BufPtr < KnownHeaderSize) return true; + + unsigned Offset = ( BufPtr[OffsetField ] | + (BufPtr[OffsetField+1] << 8) | + (BufPtr[OffsetField+2] << 16) | + (BufPtr[OffsetField+3] << 24)); + unsigned Size = ( BufPtr[SizeField ] | + (BufPtr[SizeField +1] << 8) | + (BufPtr[SizeField +2] << 16) | + (BufPtr[SizeField +3] << 24)); + + // Verify that Offset+Size fits in the file. + if (Offset+Size > unsigned(BufEnd-BufPtr)) + return true; + BufPtr += Offset; + BufEnd = BufPtr+Size; + return false; + } +} // End llvm namespace + +#endif |