[clang-tidy] Fix llvm-include-order check on Windows.

[curdeius]

Summary

IncludeDirectives struct used a StringRef that pointed to a stack variable (SmallString<128> FilenameBuffer from PPDirectives.cpp:1513).

[alexfh]

I see. The interesting thing is that it actually happens only in msvc compatibility mode (PPDirectives.cpp:1754). Thank you for finding this out!

LG. I'll commit the patch for you.

[curdeius]

This comment was removed by curdeius.

[alexfh]

Committed revision 246856.

clang-tidy/llvm/IncludeOrderCheck.cpp

void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           StringRef SearchPath, StringRef RelativePath,
                           const Module *Imported) override;
   void EndOfMainFile() override;
 
 private:
   struct IncludeDirective {
     SourceLocation Loc;    ///< '#' location in the include directive
     CharSourceRange Range; ///< SourceRange for the file name
-    StringRef Filename;    ///< Filename as a string
+    std::string Filename;  ///< Filename as a string
     bool IsAngled;         ///< true if this was an include with angle brackets
     bool IsMainModule;     ///< true if this was the first include in a file
   };
   std::vector<IncludeDirective> IncludeDirectives;
   bool LookForMainModule;
 
   ClangTidyCheck &Check;
   SourceManager &SM;

test/clang-tidy/llvm-include-order.cpp

 // RUN: %python %S/check_clang_tidy.py %s llvm-include-order %t -- -isystem %S/Inputs/Headers
 
 // FIXME: Investigating.
-// XFAIL: win32
 
 // CHECK-MESSAGES: [[@LINE+2]]:1: warning: #includes are not sorted properly
 #include "j.h"
 #include "gtest/foo.h"
 #include "i.h"
 #include <s.h>
 #include "llvm/a.h"
 #include "clang/b.h"