#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/SwapByteOrder.h"
#include "llvm/Support/Debug.h"
+#include <cstring>
#include <memory>
using namespace clang;
// Check for invalid index.
if (StrTabIdx >= FileBuffer->getBufferSize())
- return nullptr;
+ return "";
+
+ const char *Data = FileBuffer->getBufferStart() + StrTabIdx;
+ unsigned MaxLen = FileBuffer->getBufferSize() - StrTabIdx;
+ unsigned Len = strnlen(Data, MaxLen);
+
+ // Check whether the buffer is null-terminated.
+ if (Len == MaxLen && Data[Len - 1])
+ return "";
- // Otherwise, we have a valid pointer into the file. Just return it. We know
- // that the "string" can not overrun the end of the file, because the buffer
- // is nul terminated by virtue of being a MemoryBuffer.
- return FileBuffer->getBufferStart()+StrTabIdx;
+ return StringRef(Data, Len);
}
//===----------------------------------------------------------------------===//
#include "llvm/Support/SwapByteOrder.h"
#include "gtest/gtest.h"
#include <cassert>
+#include <type_traits>
using namespace clang;
using namespace llvm;
ASSERT_EQ("bc", Map.lookupFilename("a", DestPath));
}
+template <class FileTy, class PaddingTy> struct PaddedFile {
+ FileTy File;
+ PaddingTy Padding;
+};
+
+TEST(HeaderMapTest, lookupFilenameTruncated) {
+ typedef MapFile<2, 64 - sizeof(HMapHeader) - 2 * sizeof(HMapBucket)> FileTy;
+ static_assert(std::is_standard_layout<FileTy>::value,
+ "Expected standard layout");
+ static_assert(sizeof(FileTy) == 64, "check the math");
+ PaddedFile<FileTy, uint64_t> P;
+ auto &File = P.File;
+ auto &Padding = P.Padding;
+ File.init();
+
+ FileMaker<FileTy> Maker(File);
+ auto a = Maker.addString("a");
+ auto b = Maker.addString("b");
+ auto c = Maker.addString("c");
+ Maker.addBucket(getHash("a"), a, b, c);
+
+ // Add 'x' characters to cause an overflow into Padding.
+ ASSERT_EQ('c', File.Bytes[5]);
+ for (unsigned I = 6; I < sizeof(File.Bytes); ++I) {
+ ASSERT_EQ(0, File.Bytes[I]);
+ File.Bytes[I] = 'x';
+ }
+ Padding = 0xffffffff; // Padding won't stop it either.
+
+ bool NeedsSwap;
+ ASSERT_TRUE(HeaderMapImpl::checkHeader(*File.getBuffer(), NeedsSwap));
+ ASSERT_FALSE(NeedsSwap);
+ HeaderMapImpl Map(File.getBuffer(), NeedsSwap);
+
+ // The string for "c" runs to the end of File. Check that the suffix
+ // ("cxxxx...") is ignored. Another option would be to return an empty
+ // filename altogether.
+ SmallString<24> DestPath;
+ ASSERT_EQ("b", Map.lookupFilename("a", DestPath));
+}
+
} // end namespace