diff options
Diffstat (limited to 'clang/lib/Lex/HeaderMap.cpp')
| -rw-r--r-- | clang/lib/Lex/HeaderMap.cpp | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/clang/lib/Lex/HeaderMap.cpp b/clang/lib/Lex/HeaderMap.cpp index 26a179c..2b31ab9 100644 --- a/clang/lib/Lex/HeaderMap.cpp +++ b/clang/lib/Lex/HeaderMap.cpp @@ -19,6 +19,7 @@ #include "llvm/Support/DataTypes.h" #include "llvm/Support/MathExtras.h" #include "llvm/Support/MemoryBuffer.h" +#include "llvm/Support/SwapByteOrder.h" #include <cstdio> #include <memory> using namespace clang; @@ -82,6 +83,15 @@ bool HeaderMapImpl::checkHeader(const llvm::MemoryBuffer &File, if (Header->Reserved != 0) return false; + // Check the number of buckets. + auto NumBuckets = NeedsByteSwap + ? llvm::sys::getSwappedBytes(Header->NumBuckets) + : Header->NumBuckets; + + // If the number of buckets is not a power of two, the headermap is corrupt. + if (NumBuckets & (NumBuckets - 1)) + return false; + // Okay, everything looks good. return true; } @@ -191,10 +201,8 @@ StringRef HeaderMapImpl::lookupFilename(StringRef Filename, const HMapHeader &Hdr = getHeader(); unsigned NumBuckets = getEndianAdjustedWord(Hdr.NumBuckets); - // If the number of buckets is not a power of two, the headermap is corrupt. - // Don't probe infinitely. - if (NumBuckets & (NumBuckets-1)) - return StringRef(); + // Don't probe infinitely. This should be checked before constructing. + assert(!(NumBuckets & (NumBuckets - 1)) && "Expected power of 2"); // Linearly probe the hash table. for (unsigned Bucket = HashHMapKey(Filename);; ++Bucket) { |