[clang-tidy] Expand modular headers for PPCallbacks

Summary:
Add a way to expand modular headers for PPCallbacks. Checks can opt-in for this
expansion by overriding the new registerPPCallbacks virtual method and
registering their PPCallbacks in the preprocessor created for this specific
purpose.

Use module expansion in the readability-identifier-naming check

Reviewers: gribozavr, usaxena95, sammccall

Reviewed By: gribozavr

Subscribers: nemanjai, mgorny, xazax.hun, kbarton, jdoerfert, cfe-commits

Tags: #clang, #clang-tools-extra

Differential Revision: https://reviews.llvm.org/D59528

llvm-svn: 356750

2 files changed, 7 insertions, 5 deletions

diff --git a/clang-tools-extra/clang-tidy/readability/IdentifierNamingCheck.cpp b/clang-tools-extra/clang-tidy/readability/IdentifierNamingCheck.cpp
index 56ece5c60a4..7e56fe16d9b 100644
--- a/clang-tools-extra/clang-tidy/readability/IdentifierNamingCheck.cpp
+++ b/clang-tools-extra/clang-tidy/readability/IdentifierNamingCheck.cpp
@@ -240,10 +240,11 @@ void IdentifierNamingCheck::registerMatchers(MatchFinder *Finder) {
   Finder->addMatcher(nestedNameSpecifierLoc().bind("nestedNameLoc"), this);
 }
 
-void IdentifierNamingCheck::registerPPCallbacks(CompilerInstance &Compiler) {
-  Compiler.getPreprocessor().addPPCallbacks(
-      llvm::make_unique<IdentifierNamingCheckPPCallbacks>(
-          &Compiler.getPreprocessor(), this));
+void IdentifierNamingCheck::registerPPCallbacks(
+    const SourceManager &SM, Preprocessor *PP, Preprocessor *ModuleExpanderPP) {
+  ModuleExpanderPP->addPPCallbacks(
+      llvm::make_unique<IdentifierNamingCheckPPCallbacks>(ModuleExpanderPP,
+                                                          this));
 }
 
 static bool matchesStyle(StringRef Name,
diff --git a/clang-tools-extra/clang-tidy/readability/IdentifierNamingCheck.h b/clang-tools-extra/clang-tidy/readability/IdentifierNamingCheck.h
index 0023a6fa433..c0a312174c6 100644
--- a/clang-tools-extra/clang-tidy/readability/IdentifierNamingCheck.h
+++ b/clang-tools-extra/clang-tidy/readability/IdentifierNamingCheck.h
@@ -38,7 +38,8 @@ public:
   void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
   void registerMatchers(ast_matchers::MatchFinder *Finder) override;
   void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
-  void registerPPCallbacks(CompilerInstance &Compiler) override;
+  void registerPPCallbacks(const SourceManager &SM, Preprocessor *PP,
+                           Preprocessor *ModuleExpanderPP) override;
   void onEndOfTranslationUnit() override;
 
   enum CaseType {