From 3a7def09fece8d6a403f5002dd4811704fa2b3c4 Mon Sep 17 00:00:00 2001 From: "Duncan P. N. Exon Smith" Date: Mon, 22 Feb 2016 22:24:22 +0000 Subject: Lex: Check for 0 buckets on header map construction Switch to using `isPowerOf2_32()` to check whether the buckets are a power of two, and as a side benefit reject loading a header map with no buckets. This is a follow-up to r261448. llvm-svn: 261585 --- clang/lib/Lex/HeaderMap.cpp | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'clang/lib/Lex/HeaderMap.cpp') diff --git a/clang/lib/Lex/HeaderMap.cpp b/clang/lib/Lex/HeaderMap.cpp index 67b663158f0..be0d477e8b5 100644 --- a/clang/lib/Lex/HeaderMap.cpp +++ b/clang/lib/Lex/HeaderMap.cpp @@ -86,10 +86,10 @@ bool HeaderMapImpl::checkHeader(const llvm::MemoryBuffer &File, // Check the number of buckets. It should be a power of two, and there // should be enough space in the file for all of them. - auto NumBuckets = NeedsByteSwap - ? llvm::sys::getSwappedBytes(Header->NumBuckets) - : Header->NumBuckets; - if (NumBuckets & (NumBuckets - 1)) + uint32_t NumBuckets = NeedsByteSwap + ? llvm::sys::getSwappedBytes(Header->NumBuckets) + : Header->NumBuckets; + if (!llvm::isPowerOf2_32(NumBuckets)) return false; if (File.getBufferSize() < sizeof(HMapHeader) + sizeof(HMapBucket) * NumBuckets) @@ -208,7 +208,7 @@ StringRef HeaderMapImpl::lookupFilename(StringRef Filename, unsigned NumBuckets = getEndianAdjustedWord(Hdr.NumBuckets); // Don't probe infinitely. This should be checked before constructing. - assert(!(NumBuckets & (NumBuckets - 1)) && "Expected power of 2"); + assert(llvm::isPowerOf2_32(NumBuckets) && "Expected power of 2"); // Linearly probe the hash table. for (unsigned Bucket = HashHMapKey(Filename);; ++Bucket) { -- cgit v1.2.3