[clang-tidy] Pass absolute path to OptionsProvider::getOptions/getRawOptions.

[hokein]

Summary

Although there is no guarantee of getOptions/getRawOptions receiving an
absolute path, we try to make it if possible. So FileOptionProvider subclasses
don't have to convert the path to an absolute path.

[alexfh]

LG

clang-tidy/ClangTidyOptions.cpp

 }
 
 // FIXME: This method has some common logic with clang::format::getStyle().
 // Consider pulling out common bits to a findParentFileWithName function or
 // similar.
 std::vector<OptionsSource>
 FileOptionsProvider::getRawOptions(StringRef FileName) {
   DEBUG(llvm::dbgs() << "Getting options for file " << FileName << "...\n");
-  SmallString<256> FilePath(FileName);
-
-  if (std::error_code EC = llvm::sys::fs::make_absolute(FilePath)) {
-    llvm::errs() << "Can't make absolute path from " << FileName << ": "
-                 << EC.message() << "\n";
-    // FIXME: Figure out what to do.
-  } else {
-    FileName = FilePath;
-  }
 
   std::vector<OptionsSource> RawOptions =
       DefaultOptionsProvider::getRawOptions(FileName);
   OptionsSource CommandLineOptions(OverrideOptions,
                                    OptionsSourceTypeCheckCommandLineOption);
   // Look for a suitable configuration file in all parent directories of the
   // file. Start with the immediate parent directory and move up.
   StringRef Path = llvm::sys::path::parent_path(FileName);

clang-tidy/tool/ClangTidyMain.cpp

static int clangTidyMain(int argc, const char **argv) {
   if (!OptionsProvider)
     return 1;
 
   StringRef FileName("dummy");
   auto PathList = OptionsParser.getSourcePathList();
   if (!PathList.empty()) {
     FileName = PathList.front();
   }
-  ClangTidyOptions EffectiveOptions = OptionsProvider->getOptions(FileName);
+
+  SmallString<256> FilePath(FileName);
+  if (std::error_code EC = llvm::sys::fs::make_absolute(FilePath)) {
+    llvm::errs() << "Can't make absolute path from " << FileName << ": "
+                 << EC.message() << "\n";
+  }
+  ClangTidyOptions EffectiveOptions = OptionsProvider->getOptions(FilePath);
   std::vector<std::string> EnabledChecks = getCheckNames(EffectiveOptions);
 
   if (ExplainConfig) {
     //FIXME: Show other ClangTidyOptions' fields, like ExtraArg.
     std::vector<clang::tidy::ClangTidyOptionsProvider::OptionsSource>
-        RawOptions = OptionsProvider->getRawOptions(FileName);
+        RawOptions = OptionsProvider->getRawOptions(FilePath);
     for (const std::string &Check : EnabledChecks) {
       for (auto It = RawOptions.rbegin(); It != RawOptions.rend(); ++It) {
         if (It->first.Checks && GlobList(*It->first.Checks).contains(Check)) {
           llvm::outs() << "'" << Check << "' is enabled in the " << It->second
                        << ".\n";
           break;
         }
       }

test/clang-tidy/list-checks.cpp

+// REQUIRES: shell
+// RUN: mkdir -p %T/clang-tidy/list-checks/
+// RUN: echo '{Checks: "-*,google-*"}' > %T/clang-tidy/.clang-tidy
+// RUN: cd %T/clang-tidy/list-checks
+// RUN: clang-tidy -list-checks | grep "^ *google-"