[clang-tidy] Make ClangTidyOptionsProvider::getOptions return by value.

Returning by reference limits possible implementations and doesn't bring any
benefits as all callers make copies of the returned value anyway.


git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@226553 91177308-0d34-0410-b5e6-96231b3b80d8

clang-tidy/ClangTidyOptions.cpp

@@ -159,7 +159,7 @@ FileOptionsProvider::FileOptionsProvider(
 // FIXME: This method has some common logic with clang::format::getStyle().
 // Consider pulling out common bits to a findParentFileWithName function or
 // similar.
-const ClangTidyOptions &FileOptionsProvider::getOptions(StringRef FileName) {
+ClangTidyOptions FileOptionsProvider::getOptions(StringRef FileName) {
   DEBUG(llvm::dbgs() << "Getting options for file " << FileName << "...\n");
   SmallString<256> FilePath(FileName);
 

clang-tidy/ClangTidyOptions.h

@@ -95,7 +95,7 @@ public:
 
   /// \brief Returns options applying to a specific translation unit with the
   /// specified \p FileName.
-  virtual const ClangTidyOptions &getOptions(llvm::StringRef FileName) = 0;
+  virtual ClangTidyOptions getOptions(llvm::StringRef FileName) = 0;
 };
 
 /// \brief Implementation of the \c ClangTidyOptionsProvider interface, which
@@ -108,7 +108,7 @@ public:
   const ClangTidyGlobalOptions &getGlobalOptions() override {
     return GlobalOptions;
   }
-  const ClangTidyOptions &getOptions(llvm::StringRef /*FileName*/) override {
+  ClangTidyOptions getOptions(llvm::StringRef /*FileName*/) override {
     return DefaultOptions;
   }
 
@@ -187,7 +187,7 @@ public:
                       const ClangTidyOptions &OverrideOptions,
                       const ConfigFileHandlers &ConfigHandlers);
 
-  const ClangTidyOptions &getOptions(llvm::StringRef FileName) override;
+  ClangTidyOptions getOptions(llvm::StringRef FileName) override;
 
 private:
   /// \brief Try to read configuration files from \p Directory using registered