[Clang-tidy] Fix for crash in modernize-raw-string-literal check

Summary:
Clang-tidy modernize-raw-string-literal check crashes on run-time assert while it is evaluating compiler predefined identifiers such as
- __FUNCTION__
- __func__
- __PRETTY_FUNCTION__

Check is asserting because it cannot find opening quote for such string literal. It occurs only on debug build config.
I think that it would be good to prune such cases by crossing off predefined expressions - there is no need to evaluate such matches.

Reviewers: LegalizeAdulthood, alexfh

Subscribers: cfe-commits

Patch by Marek Jenda!

Differential Revision: http://reviews.llvm.org/D19331

llvm-svn: 266992

clang-tools-extra/clang-tidy/modernize/RawStringLiteralCheck.cpp

@@ -108,7 +108,8 @@ void RawStringLiteralCheck::storeOptions(ClangTidyOptions::OptionMap &Options) {
 }
 
 void RawStringLiteralCheck::registerMatchers(MatchFinder *Finder) {
-  Finder->addMatcher(stringLiteral().bind("lit"), this);
+  Finder->addMatcher(
+      stringLiteral(unless(hasParent(predefinedExpr()))).bind("lit"), this);
 }
 
 void RawStringLiteralCheck::check(const MatchFinder::MatchResult &Result) {

clang-tools-extra/test/clang-tidy/modernize-raw-string-literal.cpp

@@ -91,6 +91,10 @@ char const *const HexPrintable("\x40\\");
 // CHECK-MESSAGES: :[[@LINE-1]]:32: warning: {{.*}} can be written as a raw string literal
 // CHECK-FIXES: {{^}}char const *const HexPrintable(R"(@\)");{{$}}
 
+char const *const prettyFunction(__PRETTY_FUNCTION__);
+char const *const function(__FUNCTION__);
+char const *const func(__func__);
+
 #define TRICK(arg_) #arg_
 char const *const MacroBody = TRICK(foo\\bar);