Author: dexonsmith
Date: Mon Feb 22 18:48:16 2016
New Revision: 261596
URL: http://llvm.org/viewvc/llvm-project?rev=261596&view=rev
Log:
Lex: Return "" when HeaderMap::lookupFilename fails
Change getString() to return Optional<StringRef>, and change
lookupFilename() to return an empty string if either one of the prefix
and suffix can't be found.
This is a more robust follow-up to r261461, but it's still not entirely
satisfactory. Ideally we'd report that the header map is corrupt;
perhaps something for a follow-up.
Modified:
cfe/trunk/include/clang/Lex/HeaderMap.h
cfe/trunk/lib/Lex/HeaderMap.cpp
cfe/trunk/unittests/Lex/HeaderMapTest.cpp
Modified: cfe/trunk/include/clang/Lex/HeaderMap.h
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Lex/HeaderMap.h?rev=261596&r1=261595&r2=261596&view=diff
==============================================================================
--- cfe/trunk/include/clang/Lex/HeaderMap.h (original)
+++ cfe/trunk/include/clang/Lex/HeaderMap.h Mon Feb 22 18:48:16 2016
@@ -15,6 +15,7 @@
#define LLVM_CLANG_LEX_HEADERMAP_H
#include "clang/Basic/LLVM.h"
+#include "llvm/ADT/Optional.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/MemoryBuffer.h"
#include <memory>
@@ -53,7 +54,10 @@ private:
unsigned getEndianAdjustedWord(unsigned X) const;
const HMapHeader &getHeader() const;
HMapBucket getBucket(unsigned BucketNo) const;
- StringRef getString(unsigned StrTabIdx) const;
+
+ /// Look up the specified string in the string table. If the string index is
+ /// not valid, return None.
+ Optional<StringRef> getString(unsigned StrTabIdx) const;
};
/// This class represents an Apple concept known as a 'header map'. To the
Modified: cfe/trunk/lib/Lex/HeaderMap.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Lex/HeaderMap.cpp?rev=261596&r1=261595&r2=261596&view=diff
==============================================================================
--- cfe/trunk/lib/Lex/HeaderMap.cpp (original)
+++ cfe/trunk/lib/Lex/HeaderMap.cpp Mon Feb 22 18:48:16 2016
@@ -16,6 +16,7 @@
#include "clang/Basic/CharInfo.h"
#include "clang/Basic/FileManager.h"
#include "llvm/ADT/SmallString.h"
+#include "llvm/Support/Compiler.h"
#include "llvm/Support/DataTypes.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/MemoryBuffer.h"
@@ -144,15 +145,13 @@ HMapBucket HeaderMapImpl::getBucket(unsi
return Result;
}
-/// getString - Look up the specified string in the string table. If the
string
-/// index is not valid, it returns an empty string.
-StringRef HeaderMapImpl::getString(unsigned StrTabIdx) const {
+Optional<StringRef> HeaderMapImpl::getString(unsigned StrTabIdx) const {
// Add the start of the string table to the idx.
StrTabIdx += getEndianAdjustedWord(getHeader().StringsOffset);
// Check for invalid index.
if (StrTabIdx >= FileBuffer->getBufferSize())
- return "";
+ return None;
const char *Data = FileBuffer->getBufferStart() + StrTabIdx;
unsigned MaxLen = FileBuffer->getBufferSize() - StrTabIdx;
@@ -160,7 +159,7 @@ StringRef HeaderMapImpl::getString(unsig
// Check whether the buffer is null-terminated.
if (Len == MaxLen && Data[Len - 1])
- return "";
+ return None;
return StringRef(Data, Len);
}
@@ -177,13 +176,19 @@ LLVM_DUMP_METHOD void HeaderMapImpl::dum
llvm::dbgs() << "Header Map " << getFileName() << ":\n " << NumBuckets
<< ", " << getEndianAdjustedWord(Hdr.NumEntries) << "\n";
+ auto getStringOrInvalid = [this](unsigned Id) -> StringRef {
+ if (Optional<StringRef> S = getString(Id))
+ return *S;
+ return "<invalid>";
+ };
+
for (unsigned i = 0; i != NumBuckets; ++i) {
HMapBucket B = getBucket(i);
if (B.Key == HMAP_EmptyBucketKey) continue;
- StringRef Key = getString(B.Key);
- StringRef Prefix = getString(B.Prefix);
- StringRef Suffix = getString(B.Suffix);
+ StringRef Key = getStringOrInvalid(B.Key);
+ StringRef Prefix = getStringOrInvalid(B.Prefix);
+ StringRef Suffix = getStringOrInvalid(B.Suffix);
llvm::dbgs() << " " << i << ". " << Key << " -> '" << Prefix << "' '"
<< Suffix << "'\n";
}
@@ -216,16 +221,22 @@ StringRef HeaderMapImpl::lookupFilename(
if (B.Key == HMAP_EmptyBucketKey) return StringRef(); // Hash miss.
// See if the key matches. If not, probe on.
- if (!Filename.equals_lower(getString(B.Key)))
+ Optional<StringRef> Key = getString(B.Key);
+ if (LLVM_UNLIKELY(!Key))
+ continue;
+ if (!Filename.equals_lower(*Key))
continue;
// If so, we have a match in the hash table. Construct the destination
// path.
- StringRef Prefix = getString(B.Prefix);
- StringRef Suffix = getString(B.Suffix);
+ Optional<StringRef> Prefix = getString(B.Prefix);
+ Optional<StringRef> Suffix = getString(B.Suffix);
+
DestPath.clear();
- DestPath.append(Prefix.begin(), Prefix.end());
- DestPath.append(Suffix.begin(), Suffix.end());
+ if (LLVM_LIKELY(Prefix && Suffix)) {
+ DestPath.append(Prefix->begin(), Prefix->end());
+ DestPath.append(Suffix->begin(), Suffix->end());
+ }
return StringRef(DestPath.begin(), DestPath.size());
}
}
Modified: cfe/trunk/unittests/Lex/HeaderMapTest.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/unittests/Lex/HeaderMapTest.cpp?rev=261596&r1=261595&r2=261596&view=diff
==============================================================================
--- cfe/trunk/unittests/Lex/HeaderMapTest.cpp (original)
+++ cfe/trunk/unittests/Lex/HeaderMapTest.cpp Mon Feb 22 18:48:16 2016
@@ -185,7 +185,7 @@ template <class FileTy, class PaddingTy>
PaddingTy Padding;
};
-TEST(HeaderMapTest, lookupFilenameTruncated) {
+TEST(HeaderMapTest, lookupFilenameTruncatedSuffix) {
typedef MapFile<2, 64 - sizeof(HMapHeader) - 2 * sizeof(HMapBucket)> FileTy;
static_assert(std::is_standard_layout<FileTy>::value,
"Expected standard layout");
@@ -215,10 +215,44 @@ TEST(HeaderMapTest, lookupFilenameTrunca
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.
+ // ("cxxxx...") is detected as truncated, and an empty string is returned.
SmallString<24> DestPath;
- ASSERT_EQ("b", Map.lookupFilename("a", DestPath));
+ ASSERT_EQ("", Map.lookupFilename("a", DestPath));
+}
+
+TEST(HeaderMapTest, lookupFilenameTruncatedPrefix) {
+ 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 c = Maker.addString("c");
+ auto b = Maker.addString("b"); // Store the prefix last.
+ Maker.addBucket(getHash("a"), a, b, c);
+
+ // Add 'x' characters to cause an overflow into Padding.
+ ASSERT_EQ('b', 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 "b" runs to the end of File. Check that the prefix
+ // ("bxxxx...") is detected as truncated, and an empty string is returned.
+ SmallString<24> DestPath;
+ ASSERT_EQ("", Map.lookupFilename("a", DestPath));
}
} // end namespace
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
