Author: dexonsmith
Date: Mon Feb 22 16:24:22 2016
New Revision: 261585
URL: http://llvm.org/viewvc/llvm-project?rev=261585&view=rev
Log:
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.
Modified:
cfe/trunk/lib/Lex/HeaderMap.cpp
cfe/trunk/unittests/Lex/HeaderMapTest.cpp
Modified: cfe/trunk/lib/Lex/HeaderMap.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Lex/HeaderMap.cpp?rev=261585&r1=261584&r2=261585&view=diff
==============================================================================
--- cfe/trunk/lib/Lex/HeaderMap.cpp (original)
+++ cfe/trunk/lib/Lex/HeaderMap.cpp Mon Feb 22 16:24:22 2016
@@ -86,10 +86,10 @@ bool HeaderMapImpl::checkHeader(const ll
// 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(
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) {
Modified: cfe/trunk/unittests/Lex/HeaderMapTest.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/unittests/Lex/HeaderMapTest.cpp?rev=261585&r1=261584&r2=261585&view=diff
==============================================================================
--- cfe/trunk/unittests/Lex/HeaderMapTest.cpp (original)
+++ cfe/trunk/unittests/Lex/HeaderMapTest.cpp Mon Feb 22 16:24:22 2016
@@ -143,6 +143,15 @@ TEST(HeaderMapTest, checkHeader3Buckets)
ASSERT_FALSE(HeaderMapImpl::checkHeader(*File.getBuffer(), NeedsSwap));
}
+TEST(HeaderMapTest, checkHeader0Buckets) {
+ // Create with 1 bucket to avoid 0-sized arrays.
+ MapFile<1, 1> File;
+ File.init();
+ File.Header.NumBuckets = 0;
+ bool NeedsSwap;
+ ASSERT_FALSE(HeaderMapImpl::checkHeader(*File.getBuffer(), NeedsSwap));
+}
+
TEST(HeaderMapTest, checkHeaderNotEnoughBuckets) {
MapFile<1, 1> File;
File.init();
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
