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
diff --git a/lib/Bitcode/Reader/BitcodeReader.cpp b/lib/Bitcode/Reader/BitcodeReader.cpp
index 66ccdc2..6f91dda 100644
--- a/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -1330,48 +1330,6 @@
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 @@
// 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);