Lex: Add some unit tests for corrupt header maps

Split the implementation of `HeaderMap` into `HeaderMapImpl` so that we
can write unit tests that don't depend on the `FileManager`, and then
write a few tests that cover the types of corrupt header maps already
detected.

This also moves type and constant definitions from HeaderMap.cpp to
HeaderMapTypes.h so that the test can access them.

llvm-svn: 261446

1 files changed, 94 insertions, 0 deletions

diff --git a/clang/unittests/Lex/HeaderMapTest.cpp b/clang/unittests/Lex/HeaderMapTest.cpp
new file mode 100644
index 00000000000..726e89c2751
--- /dev/null
+++ b/clang/unittests/Lex/HeaderMapTest.cpp
@@ -0,0 +1,94 @@
+//===- unittests/Lex/HeaderMapTest.cpp - HeaderMap tests ----------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===--------------------------------------------------------------===//
+
+#include "clang/Lex/HeaderMap.h"
+#include "clang/Lex/HeaderMapTypes.h"
+#include "llvm/Support/SwapByteOrder.h"
+#include "gtest/gtest.h"
+
+using namespace clang;
+using namespace llvm;
+
+namespace {
+
+// Lay out a header file for testing.
+template <unsigned NumBuckets, unsigned NumBytes> struct MapFile {
+  HMapHeader Header;
+  HMapBucket Buckets[NumBuckets];
+  unsigned char Bytes[NumBytes];
+
+  void init() {
+    memset(this, 0, sizeof(MapFile));
+    Header.Magic = HMAP_HeaderMagicNumber;
+    Header.Version = HMAP_HeaderVersion;
+    Header.NumBuckets = NumBuckets;
+    Header.StringsOffset = sizeof(Header) + sizeof(Buckets);
+  }
+
+  void swapBytes() {
+    using llvm::sys::getSwappedBytes;
+    Header.Magic = getSwappedBytes(Header.Magic);
+    Header.Version = getSwappedBytes(Header.Version);
+    Header.NumBuckets = getSwappedBytes(Header.NumBuckets);
+    Header.StringsOffset = getSwappedBytes(Header.StringsOffset);
+  }
+
+  std::unique_ptr<const MemoryBuffer> getBuffer() const {
+    return MemoryBuffer::getMemBuffer(
+        StringRef(reinterpret_cast<const char *>(this), sizeof(MapFile)),
+        "header",
+        /* RequresNullTerminator */ false);
+  }
+};
+
+TEST(HeaderMapTest, checkHeaderEmpty) {
+  bool NeedsSwap;
+  ASSERT_FALSE(HeaderMapImpl::checkHeader(
+      *MemoryBuffer::getMemBufferCopy("", "empty"), NeedsSwap));
+  ASSERT_FALSE(HeaderMapImpl::checkHeader(
+      *MemoryBuffer::getMemBufferCopy("", "empty"), NeedsSwap));
+}
+
+TEST(HeaderMapTest, checkHeaderMagic) {
+  MapFile<1, 1> File;
+  File.init();
+  File.Header.Magic = 0;
+  bool NeedsSwap;
+  ASSERT_FALSE(HeaderMapImpl::checkHeader(*File.getBuffer(), NeedsSwap));
+}
+
+TEST(HeaderMapTest, checkHeaderReserved) {
+  MapFile<1, 1> File;
+  File.init();
+  File.Header.Reserved = 1;
+  bool NeedsSwap;
+  ASSERT_FALSE(HeaderMapImpl::checkHeader(*File.getBuffer(), NeedsSwap));
+}
+
+TEST(HeaderMapTest, checkHeaderVersion) {
+  MapFile<1, 1> File;
+  File.init();
+  ++File.Header.Version;
+  bool NeedsSwap;
+  ASSERT_FALSE(HeaderMapImpl::checkHeader(*File.getBuffer(), NeedsSwap));
+}
+
+TEST(HeaderMapTest, checkHeaderValidButEmpty) {
+  MapFile<1, 1> File;
+  File.init();
+  bool NeedsSwap;
+  ASSERT_TRUE(HeaderMapImpl::checkHeader(*File.getBuffer(), NeedsSwap));
+  ASSERT_FALSE(NeedsSwap);
+
+  File.swapBytes();
+  ASSERT_TRUE(HeaderMapImpl::checkHeader(*File.getBuffer(), NeedsSwap));
+  ASSERT_TRUE(NeedsSwap);
+}
+
+} // end namespace