//
// The LLVM Compiler Infrastructure
//
-// This file was developed by Chris Lattner and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
#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 LLVMContext;
+ class raw_ostream;
- /// getBitcodeModuleProvider - Read the header of the specified bitcode buffer
+ /// 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.
- ModuleProvider *getBitcodeModuleProvider(MemoryBuffer *Buffer,
- std::string *ErrMsg = 0);
+ Module *getLazyBitcodeModule(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, std::string *ErrMsg = 0);
+ 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);
+
+ /// 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(raw_ostream &Str);
- /// WriteBitcodeToFile - Write the specified module to the specified output
- /// stream.
- void WriteBitcodeToFile(const Module *M, std::ostream &Out);
- /// CreateBitcodeWriterPass - Create and return a pass that writes the module
- /// to the specified ostream.
- ModulePass *CreateBitcodeWriterPass(std::ostream &Str);
+ /// isBitcodeWrapper - Return true if the given bytes are the magic bytes
+ /// for an LLVM IR bitcode wrapper.
+ ///
+ static 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).
+ ///
+ static 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.
+ ///
+ static bool inline 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.
+ 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