/usr/include/llvm-3.4/llvm/Bitcode/ReaderWriter.h is in llvm-3.4-dev 1:3.4-1ubuntu3~precise2.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 | //===-- 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_READERWRITER_H
#define LLVM_BITCODE_READERWRITER_H
#include <string>
namespace llvm {
class BitstreamWriter;
class MemoryBuffer;
class DataStreamer;
class LLVMContext;
class Module;
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);
/// getStreamedBitcodeModule - Read the header of the specified stream
/// and prepare for lazy deserialization and streaming of function bodies.
/// On error, this returns null, and fills in *ErrMsg with an error
/// description if ErrMsg is non-null.
Module *getStreamedBitcodeModule(const std::string &name,
DataStreamer *streamer,
LLVMContext &Context,
std::string *ErrMsg = 0);
/// getBitcodeTargetTriple - Read the header of the specified bitcode
/// buffer and extract just the triple information. If successful,
/// this returns a string and *does not* take ownership
/// of 'buffer'. On error, this returns "", and fills in *ErrMsg
/// if ErrMsg is non-null.
std::string getBitcodeTargetTriple(MemoryBuffer *Buffer,
LLVMContext &Context,
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, LLVMContext &Context,
std::string *ErrMsg = 0);
/// WriteBitcodeToFile - Write the specified module to the specified
/// raw output stream. For streams where it matters, the given stream
/// should be in "binary" mode.
void WriteBitcodeToFile(const Module *M, raw_ostream &Out);
/// createBitcodeWriterPass - Create and return a pass that writes the module
/// to the specified ostream.
ModulePass *createBitcodeWriterPass(raw_ostream &Str);
/// isBitcodeWrapper - Return true if the given bytes are the magic bytes
/// for an LLVM IR bitcode wrapper.
///
inline bool isBitcodeWrapper(const unsigned char *BufPtr,
const unsigned char *BufEnd) {
// See if you can find the hidden message in the magic bytes :-).
// (Hint: it's a little-endian encoding.)
return BufPtr != BufEnd &&
BufPtr[0] == 0xDE &&
BufPtr[1] == 0xC0 &&
BufPtr[2] == 0x17 &&
BufPtr[3] == 0x0B;
}
/// isRawBitcode - Return true if the given bytes are the magic bytes for
/// raw LLVM IR bitcode (without a wrapper).
///
inline bool isRawBitcode(const unsigned char *BufPtr,
const unsigned char *BufEnd) {
// These bytes sort of have a hidden message, but it's not in
// little-endian this time, and it's a little redundant.
return BufPtr != BufEnd &&
BufPtr[0] == 'B' &&
BufPtr[1] == 'C' &&
BufPtr[2] == 0xc0 &&
BufPtr[3] == 0xde;
}
/// isBitcode - Return true if the given bytes are the magic bytes for
/// LLVM IR bitcode, either with or without a wrapper.
///
inline bool isBitcode(const unsigned char *BufPtr,
const unsigned char *BufEnd) {
return isBitcodeWrapper(BufPtr, BufEnd) ||
isRawBitcode(BufPtr, BufEnd);
}
/// 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.
/// If 'VerifyBufferSize' is true, check that the buffer is large enough to
/// contain the whole bitcode file.
inline bool SkipBitcodeWrapperHeader(const unsigned char *&BufPtr,
const unsigned char *&BufEnd,
bool VerifyBufferSize) {
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 (VerifyBufferSize && Offset+Size > unsigned(BufEnd-BufPtr))
return true;
BufPtr += Offset;
BufEnd = BufPtr+Size;
return false;
}
} // End llvm namespace
#endif
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