[modules] Do not serialize / deserialize pending new/delete mismatch

checks across module boundaries. This was causing us to load constructor
definitions for all consumers of a module with a pending check.

(In one case we saw ~7% of total frontend time spent loading
constructors for this check.)

llvm-svn: 335807

1 files changed, 7 insertions, 10 deletions

diff --git a/clang/lib/Sema/Sema.cpp b/clang/lib/Sema/Sema.cpp
index 7a8cd1ca4e6..d6d105c3b04 100644
--- a/clang/lib/Sema/Sema.cpp
+++ b/clang/lib/Sema/Sema.cpp
@@ -1010,11 +1010,6 @@ void Sema::ActOnEndOfTranslationUnit() {
     // Warnings emitted in ActOnEndOfTranslationUnit() should be emitted for
     // modules when they are built, not every time they are used.
     emitAndClearUnusedLocalTypedefWarnings();
-
-    // Modules don't need any of the checking below.
-    if (!PP.isIncrementalProcessingEnabled())
-      TUScope = nullptr;
-    return;
   }
 
   // C99 6.9.2p2:
@@ -1032,8 +1027,7 @@ void Sema::ActOnEndOfTranslationUnit() {
   for (TentativeDefinitionsType::iterator
             T = TentativeDefinitions.begin(ExternalSource),
          TEnd = TentativeDefinitions.end();
-       T != TEnd; ++T)
-  {
+       T != TEnd; ++T) {
     VarDecl *VD = (*T)->getActingDefinition();
 
     // If the tentative definition was completed, getActingDefinition() returns
@@ -1060,12 +1054,13 @@ void Sema::ActOnEndOfTranslationUnit() {
     // Notify the consumer that we've completed a tentative definition.
     if (!VD->isInvalidDecl())
       Consumer.CompleteTentativeDefinition(VD);
-
   }
 
   // If there were errors, disable 'unused' warnings since they will mostly be
-  // noise.
-  if (!Diags.hasErrorOccurred()) {
+  // noise. Don't warn for a use from a module: either we should warn on all
+  // file-scope declarations in modules or not at all, but whether the
+  // declaration is used is immaterial.
+  if (!Diags.hasErrorOccurred() && TUKind != TU_Module) {
     // Output warning for unused file scoped decls.
     for (UnusedFileScopedDeclsType::iterator
            I = UnusedFileScopedDecls.begin(ExternalSource),
@@ -1133,6 +1128,8 @@ void Sema::ActOnEndOfTranslationUnit() {
   }
 
   if (!Diags.isIgnored(diag::warn_unused_private_field, SourceLocation())) {
+    // FIXME: Load additional unused private field candidates from the external
+    // source.
     RecordCompleteMap RecordsComplete;
     RecordCompleteMap MNCComplete;
     for (NamedDeclSetType::iterator I = UnusedPrivateFields.begin(),