Return early from Sema::MarkDeclarationReferenced when we know there

isn't any extra work to perform. Also, don't check for unused
parameters when the warnings will be suppressed anyway. Improves
performance of -fsyntax-only on 403.gcc's combine.c by ~2.5%. 
<rdar://problem/7836787>

llvm-svn: 100686

2 files changed, 11 insertions, 2 deletions

diff --git a/clang/lib/Sema/Sema.h b/clang/lib/Sema/Sema.h
index c93acf69461..a6bcc4375e4 100644
--- a/clang/lib/Sema/Sema.h
+++ b/clang/lib/Sema/Sema.h
@@ -843,6 +843,10 @@ public:
   /// ParmVarDecl pointers.
   template<typename InputIterator>
   void DiagnoseUnusedParameters(InputIterator Param, InputIterator ParamEnd) {
+    if (Diags.getDiagnosticLevel(diag::warn_unused_parameter) == 
+          Diagnostic::Ignored)
+      return;
+    
     for (; Param != ParamEnd; ++Param) {
       if (!(*Param)->isUsed() && (*Param)->getDeclName() &&
           !(*Param)->template hasAttr<UnusedAttr>())
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 7967a342a25..b78e8b5b67b 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -7311,9 +7311,14 @@ void Sema::MarkDeclarationReferenced(SourceLocation Loc, Decl *D) {
   // (e.g. (void)sizeof()) constitute a use for warning purposes (-Wunused-variables and
   // -Wunused-parameters)
   if (isa<ParmVarDecl>(D) ||
-      (isa<VarDecl>(D) && D->getDeclContext()->isFunctionOrMethod()))
+      (isa<VarDecl>(D) && D->getDeclContext()->isFunctionOrMethod())) {
     D->setUsed(true);
-
+    return;
+  }
+  
+  if (!isa<VarDecl>(D) && !isa<FunctionDecl>(D))
+    return;
+  
   // Do not mark anything as "used" within a dependent context; wait for
   // an instantiation.
   if (CurContext->isDependentContext())