diff options
| -rw-r--r-- | include/llvm/Bitcode/BitstreamWriter.h | 20 | ||||
| -rw-r--r-- | lib/Bitcode/Writer/BitcodeWriter.cpp | 90 |
2 files changed, 56 insertions, 54 deletions
diff --git a/include/llvm/Bitcode/BitstreamWriter.h b/include/llvm/Bitcode/BitstreamWriter.h index 41e3e08..250a20f 100644 --- a/include/llvm/Bitcode/BitstreamWriter.h +++ b/include/llvm/Bitcode/BitstreamWriter.h @@ -59,6 +59,15 @@ class BitstreamWriter { }; std::vector<BlockInfo> BlockInfoRecords; + // BackpatchWord - Backpatch a 32-bit word in the output with the specified + // value. + void BackpatchWord(unsigned ByteNo, unsigned NewWord) { + Out[ByteNo++] = (unsigned char)(NewWord >> 0); + Out[ByteNo++] = (unsigned char)(NewWord >> 8); + Out[ByteNo++] = (unsigned char)(NewWord >> 16); + Out[ByteNo ] = (unsigned char)(NewWord >> 24); + } + public: explicit BitstreamWriter(std::vector<unsigned char> &O) : Out(O), CurBit(0), CurValue(0), CurCodeSize(2) {} @@ -78,8 +87,6 @@ public: } } - std::vector<unsigned char> &getBuffer() { return Out; } - /// \brief Retrieve the current position in the stream, in bits. uint64_t GetCurrentBitNo() const { return Out.size() * 8 + CurBit; } @@ -164,15 +171,6 @@ public: Emit(Val, CurCodeSize); } - // BackpatchWord - Backpatch a 32-bit word in the output with the specified - // value. - void BackpatchWord(unsigned ByteNo, unsigned NewWord) { - Out[ByteNo++] = (unsigned char)(NewWord >> 0); - Out[ByteNo++] = (unsigned char)(NewWord >> 8); - Out[ByteNo++] = (unsigned char)(NewWord >> 16); - Out[ByteNo ] = (unsigned char)(NewWord >> 24); - } - //===--------------------------------------------------------------------===// // Block Manipulation //===--------------------------------------------------------------------===// diff --git a/lib/Bitcode/Writer/BitcodeWriter.cpp b/lib/Bitcode/Writer/BitcodeWriter.cpp index 7078169..c6c7fb7 100644 --- a/lib/Bitcode/Writer/BitcodeWriter.cpp +++ b/lib/Bitcode/Writer/BitcodeWriter.cpp @@ -1774,7 +1774,18 @@ enum { DarwinBCHeaderSize = 5*4 }; -static void EmitDarwinBCHeader(BitstreamWriter &Stream, const Triple &TT) { +static void WriteInt32ToBuffer(uint32_t Value, + std::vector<unsigned char> &Buffer, + uint32_t &Position) { + Buffer[Position + 0] = (unsigned char) (Value >> 0); + Buffer[Position + 1] = (unsigned char) (Value >> 8); + Buffer[Position + 2] = (unsigned char) (Value >> 16); + Buffer[Position + 3] = (unsigned char) (Value >> 24); + Position += 4; +} + +static void EmitDarwinBCHeaderAndTrailer(std::vector<unsigned char> &Buffer, + const Triple &TT) { unsigned CPUType = ~0U; // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*, @@ -1801,62 +1812,55 @@ static void EmitDarwinBCHeader(BitstreamWriter &Stream, const Triple &TT) { CPUType = DARWIN_CPU_TYPE_ARM; // Traditional Bitcode starts after header. + assert(Buffer.size() >= DarwinBCHeaderSize && + "Expected header size to be reserved"); unsigned BCOffset = DarwinBCHeaderSize; + unsigned BCSize = Buffer.size()-DarwinBCHeaderSize; - Stream.Emit(0x0B17C0DE, 32); - Stream.Emit(0 , 32); // Version. - Stream.Emit(BCOffset , 32); - Stream.Emit(0 , 32); // Filled in later. - Stream.Emit(CPUType , 32); -} - -/// EmitDarwinBCTrailer - Emit the darwin epilog after the bitcode file and -/// finalize the header. -static void EmitDarwinBCTrailer(BitstreamWriter &Stream, unsigned BufferSize) { - // Update the size field in the header. - Stream.BackpatchWord(DarwinBCSizeFieldOffset, BufferSize-DarwinBCHeaderSize); + // Write the magic and version. + unsigned Position = 0; + WriteInt32ToBuffer(0x0B17C0DE , Buffer, Position); + WriteInt32ToBuffer(0 , Buffer, Position); // Version. + WriteInt32ToBuffer(BCOffset , Buffer, Position); + WriteInt32ToBuffer(BCSize , Buffer, Position); + WriteInt32ToBuffer(CPUType , Buffer, Position); // If the file is not a multiple of 16 bytes, insert dummy padding. - while (BufferSize & 15) { - Stream.Emit(0, 8); - ++BufferSize; - } + while (Buffer.size() & 15) + Buffer.push_back(0); } -static void WriteBitcodeToStream(const Module *M, BitstreamWriter &Stream); - /// WriteBitcodeToFile - Write the specified module to the specified output /// stream. void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out) { std::vector<unsigned char> Buffer; - BitstreamWriter Stream(Buffer); - Buffer.reserve(256*1024); - WriteBitcodeToStream( M, Stream ); - - // Write the generated bitstream to "Out". - Out.write((char*)&Buffer.front(), Buffer.size()); -} - -static void WriteBitcodeToStream(const Module *M, BitstreamWriter &Stream) { - // If this is darwin or another generic macho target, emit a file header and - // trailer if needed. + // If this is darwin or another generic macho target, reserve space for the + // header. Triple TT(M->getTargetTriple()); if (TT.isOSDarwin()) - EmitDarwinBCHeader(Stream, TT); - - // Emit the file header. - Stream.Emit((unsigned)'B', 8); - Stream.Emit((unsigned)'C', 8); - Stream.Emit(0x0, 4); - Stream.Emit(0xC, 4); - Stream.Emit(0xE, 4); - Stream.Emit(0xD, 4); - - // Emit the module. - WriteModule(M, Stream); + Buffer.insert(Buffer.begin(), DarwinBCHeaderSize, 0); + + // Emit the module into the buffer. + { + BitstreamWriter Stream(Buffer); + + // Emit the file header. + Stream.Emit((unsigned)'B', 8); + Stream.Emit((unsigned)'C', 8); + Stream.Emit(0x0, 4); + Stream.Emit(0xC, 4); + Stream.Emit(0xE, 4); + Stream.Emit(0xD, 4); + + // Emit the module. + WriteModule(M, Stream); + } if (TT.isOSDarwin()) - EmitDarwinBCTrailer(Stream, Stream.getBuffer().size()); + EmitDarwinBCHeaderAndTrailer(Buffer, TT); + + // Write the generated bitstream to "Out". + Out.write((char*)&Buffer.front(), Buffer.size()); } |