From e2a466bfa9e4f43c90602da5f602c16c2c83c866 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Mon, 6 Apr 2009 20:54:32 +0000 Subject: [PATCH] Teach llvm-bcanalyzer to skip over the header we use on LLVM IR files. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68458 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/Bitcode/ReaderWriter.h | 53 ++++++++++++++++++++++- lib/Bitcode/Reader/BitcodeReader.cpp | 47 +------------------- tools/llvm-bcanalyzer/llvm-bcanalyzer.cpp | 21 ++++++--- 3 files changed, 69 insertions(+), 52 deletions(-) diff --git a/include/llvm/Bitcode/ReaderWriter.h b/include/llvm/Bitcode/ReaderWriter.h index ce5c29cf9f6..abdd5d3d8b1 100644 --- a/include/llvm/Bitcode/ReaderWriter.h +++ b/include/llvm/Bitcode/ReaderWriter.h @@ -24,7 +24,7 @@ namespace llvm { 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 @@ -57,6 +57,57 @@ namespace llvm { /// 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 diff --git a/lib/Bitcode/Reader/BitcodeReader.cpp b/lib/Bitcode/Reader/BitcodeReader.cpp index 66ccdc2f90d..6f91dda5012 100644 --- a/lib/Bitcode/Reader/BitcodeReader.cpp +++ b/lib/Bitcode/Reader/BitcodeReader.cpp @@ -1330,48 +1330,6 @@ bool BitcodeReader::ParseModule(const std::string &ModuleID) { return Error("Premature end of bitstream"); } -/// SkipWrapperHeader - 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 bool SkipWrapperHeader(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; -} - bool BitcodeReader::ParseBitcode() { TheModule = 0; @@ -1383,9 +1341,8 @@ bool BitcodeReader::ParseBitcode() { // If we have a wrapper header, parse it and ignore the non-bc file contents. // The magic number is 0x0B17C0DE stored in little endian. - if (BufPtr != BufEnd && BufPtr[0] == 0xDE && BufPtr[1] == 0xC0 && - BufPtr[2] == 0x17 && BufPtr[3] == 0x0B) - if (SkipWrapperHeader(BufPtr, BufEnd)) + if (isBitcodeWrapper(BufPtr, BufEnd)) + if (SkipBitcodeWrapperHeader(BufPtr, BufEnd)) return Error("Invalid bitcode wrapper header"); Stream.init(BufPtr, BufEnd); diff --git a/tools/llvm-bcanalyzer/llvm-bcanalyzer.cpp b/tools/llvm-bcanalyzer/llvm-bcanalyzer.cpp index 52a198ae790..cde27fac48c 100644 --- a/tools/llvm-bcanalyzer/llvm-bcanalyzer.cpp +++ b/tools/llvm-bcanalyzer/llvm-bcanalyzer.cpp @@ -30,6 +30,7 @@ #include "llvm/Analysis/Verifier.h" #include "llvm/Bitcode/BitstreamReader.h" #include "llvm/Bitcode/LLVMBitCodes.h" +#include "llvm/Bitcode/ReaderWriter.h" #include "llvm/Support/CommandLine.h" #include "llvm/Support/ManagedStatic.h" #include "llvm/Support/MemoryBuffer.h" @@ -382,16 +383,24 @@ static void PrintSize(double Bits) { /// AnalyzeBitcode - Analyze the bitcode file specified by InputFilename. static int AnalyzeBitcode() { // Read the input file. - MemoryBuffer *Buffer = MemoryBuffer::getFileOrSTDIN(InputFilename.c_str()); + MemoryBuffer *MemBuf = MemoryBuffer::getFileOrSTDIN(InputFilename.c_str()); - if (Buffer == 0) + if (MemBuf == 0) return Error("Error reading '" + InputFilename + "'."); - if (Buffer->getBufferSize() & 3) + if (MemBuf->getBufferSize() & 3) return Error("Bitcode stream should be a multiple of 4 bytes in length"); - unsigned char *BufPtr = (unsigned char *)Buffer->getBufferStart(); - BitstreamReader Stream(BufPtr, BufPtr+Buffer->getBufferSize()); + unsigned char *BufPtr = (unsigned char *)MemBuf->getBufferStart(); + unsigned char *EndBufPtr = BufPtr+MemBuf->getBufferSize(); + + // If we have a wrapper header, parse it and ignore the non-bc file contents. + // The magic number is 0x0B17C0DE stored in little endian. + if (isBitcodeWrapper(BufPtr, EndBufPtr)) + if (SkipBitcodeWrapperHeader(BufPtr, EndBufPtr)) + return Error("Invalid bitcode wrapper header"); + + BitstreamReader Stream(BufPtr, EndBufPtr); // Read the stream signature. @@ -425,7 +434,7 @@ static int AnalyzeBitcode() { if (Dump) std::cerr << "\n\n"; - uint64_t BufferSizeBits = Buffer->getBufferSize()*CHAR_BIT; + uint64_t BufferSizeBits = (EndBufPtr-BufPtr)*CHAR_BIT; // Print a summary of the read file. std::cerr << "Summary of " << InputFilename << ":\n"; std::cerr << " Total size: ";