Flip the order the preprocessor and frontendaction are informed of the end of a file.

[bkramer]

Summary

This allows using EndOfMainFile from a PPCallback to access data from the
action. The pattern of PPCallback referencing an action is common in clang-tidy.

[klimek]

I'm fine with it - we might want to ask Richard whether he can imagine any problems with this change...

[rsmith]

This seems like a more natural order for these actions to me. Can you add a test? (Install a preprocessing callback and check that its EndOfMainFile action is called before the FrontendAction's EndSourceFileAction)

[bkramer]

Added unit test.

[rsmith]

LGTM

[bkramer]

Closed by commit rL215145 (authored by d0k).

lib/Frontend/FrontendAction.cpp

 }
 
 void FrontendAction::EndSourceFile() {
   CompilerInstance &CI = getCompilerInstance();
 
   // Inform the diagnostic client we are done with this source file.
   CI.getDiagnosticClient().EndSourceFile();
 
+  // Inform the preprocessor we are done.
+  if (CI.hasPreprocessor())
+    CI.getPreprocessor().EndSourceFile();
+
   // Finalize the action.
   EndSourceFileAction();
 
   // Sema references the ast consumer, so reset sema first.
   //
   // FIXME: There is more per-file stuff we could just drop here?
   bool DisableFree = CI.getFrontendOpts().DisableFree;
   if (DisableFree) {
     if (!isCurrentFileAST()) {
       CI.resetAndLeakSema();
       CI.resetAndLeakASTContext();
     }
     BuryPointer(CI.takeASTConsumer());
   } else {
     if (!isCurrentFileAST()) {
       CI.setSema(nullptr);
       CI.setASTContext(nullptr);
     }
     CI.setASTConsumer(nullptr);
   }
 
-  // Inform the preprocessor we are done.
-  if (CI.hasPreprocessor())
-    CI.getPreprocessor().EndSourceFile();
-
   if (CI.getFrontendOpts().ShowStats) {
     llvm::errs() << "\nSTATISTICS FOR '" << getCurrentFile() << "':\n";
     CI.getPreprocessor().PrintStats();
     CI.getPreprocessor().getIdentifierTable().PrintStats();
     CI.getPreprocessor().getHeaderSearchInfo().PrintStats();
     CI.getSourceManager().PrintStats();
     llvm::errs() << "\n";
   }