3 files changed, 67 insertions, 35 deletions

diff --git a/lib/Sema/AnalysisBasedWarnings.cpp b/lib/Sema/AnalysisBasedWarnings.cpp
index 3567b6bbe0..9b3191b027 100644
--- a/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/lib/Sema/AnalysisBasedWarnings.cpp
@@ -415,42 +415,15 @@ static bool SuggestInitializationFixit(Sema &S, const VarDecl *VD) {
     return false;
 
   // Suggest possible initialization (if any).
-  const char *initialization = 0;
   QualType VariableTy = VD->getType().getCanonicalType();
-
-  if (VariableTy->isObjCObjectPointerType() ||
-      VariableTy->isBlockPointerType()) {
-    // Check if 'nil' is defined.
-    if (S.PP.getMacroInfo(&S.getASTContext().Idents.get("nil")))
-      initialization = " = nil";
-    else
-      initialization = " = 0";
-  }
-  else if (VariableTy->isRealFloatingType())
-    initialization = " = 0.0";
-  else if (VariableTy->isBooleanType() && S.Context.getLangOptions().CPlusPlus)
-    initialization = " = false";
-  else if (VariableTy->isEnumeralType())
+  const char *Init = S.getFixItZeroInitializerForType(VariableTy);
+  if (!Init)
     return false;
-  else if (VariableTy->isPointerType() || VariableTy->isMemberPointerType()) {
-    if (S.Context.getLangOptions().CPlusPlus0x)
-      initialization = " = nullptr";
-    // Check if 'NULL' is defined.
-    else if (S.PP.getMacroInfo(&S.getASTContext().Idents.get("NULL")))
-      initialization = " = NULL";
-    else
-      initialization = " = 0";
-  }
-  else if (VariableTy->isScalarType())
-    initialization = " = 0";
 
-  if (initialization) {
-    SourceLocation loc = S.PP.getLocForEndOfToken(VD->getLocEnd());
-    S.Diag(loc, diag::note_var_fixit_add_initialization) << VD->getDeclName()
-      << FixItHint::CreateInsertion(loc, initialization);
-    return true;
-  }
-  return false;
+  SourceLocation Loc = S.PP.getLocForEndOfToken(VD->getLocEnd());
+  S.Diag(Loc, diag::note_var_fixit_add_initialization) << VD->getDeclName()
+    << FixItHint::CreateInsertion(Loc, Init);
+  return true;
 }
 
 /// DiagnoseUninitializedUse -- Helper function for diagnosing uses of an
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index dc8d6ec8cf..4dcf1db2cf 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -4921,8 +4921,39 @@ Sema::ActOnFunctionDeclarator(Scope *S, Declarator &D, DeclContext *DC,
       if (!T->isVoidType() && C.Fun.NumArgs == 0 && !C.Fun.isVariadic &&
           !C.Fun.TrailingReturnType &&
           C.Fun.getExceptionSpecType() == EST_None) {
-        Diag(C.Loc, diag::warn_empty_parens_are_function_decl)
-          << SourceRange(C.Loc, C.EndLoc);
+        SourceRange ParenRange(C.Loc, C.EndLoc);
+        Diag(C.Loc, diag::warn_empty_parens_are_function_decl) << ParenRange;
+
+        // If the declaration looks like:
+        //   T var1,
+        //   f();
+        // and name lookup finds a function named 'f', then the ',' was
+        // probably intended to be a ';'.
+        if (!D.isFirstDeclarator() && D.getIdentifier()) {
+          FullSourceLoc Comma(D.getCommaLoc(), SourceMgr);
+          FullSourceLoc Name(D.getIdentifierLoc(), SourceMgr);
+          if (Comma.getFileID() != Name.getFileID() ||
+              Comma.getSpellingLineNumber() != Name.getSpellingLineNumber()) {
+            LookupResult Result(*this, D.getIdentifier(), SourceLocation(),
+                                LookupOrdinaryName);
+            if (LookupName(Result, S))
+              Diag(D.getCommaLoc(), diag::note_empty_parens_function_call)
+                << FixItHint::CreateReplacement(D.getCommaLoc(), ";") << NewFD;
+          }
+        }
+        const CXXRecordDecl *RD = T->getAsCXXRecordDecl();
+        // Empty parens mean value-initialization, and no parens mean default
+        // initialization. These are equivalent if the default constructor is
+        // user-provided, or if zero-initialization is a no-op.
+        if (RD && (RD->isEmpty() || RD->hasUserProvidedDefaultConstructor()))
+          Diag(C.Loc, diag::note_empty_parens_default_ctor)
+            << FixItHint::CreateRemoval(ParenRange);
+        else if (const char *Init = getFixItZeroInitializerForType(T))
+          Diag(C.Loc, diag::note_empty_parens_zero_initialize)
+            << FixItHint::CreateReplacement(ParenRange, Init);
+        else if (LangOpts.CPlusPlus0x)
+          Diag(C.Loc, diag::note_empty_parens_zero_initialize)
+            << FixItHint::CreateReplacement(ParenRange, "{}");
       }
     }
 
diff --git a/lib/Sema/SemaFixItUtils.cpp b/lib/Sema/SemaFixItUtils.cpp
index 8e8a46da73..1f17a9e83e 100644
--- a/lib/Sema/SemaFixItUtils.cpp
+++ b/lib/Sema/SemaFixItUtils.cpp
@@ -158,3 +158,31 @@ bool ConversionFixItGenerator::tryToFixConversion(const Expr *FullExpr,
 
   return false;
 }
+
+const char *Sema::getFixItZeroInitializerForType(QualType T) const {
+  // Suggest 'nil' if it's defined and appropriate.
+  if ((T->isObjCObjectPointerType() || T->isBlockPointerType()) &&
+      PP.getMacroInfo(&getASTContext().Idents.get("nil")))
+    return " = nil";
+  if (T->isRealFloatingType())
+    return " = 0.0";
+  if (T->isBooleanType() && LangOpts.CPlusPlus)
+    return " = false";
+  if (T->isPointerType() || T->isMemberPointerType()) {
+    if (LangOpts.CPlusPlus0x)
+      return " = nullptr";
+    // Check if 'NULL' is defined.
+    else if (PP.getMacroInfo(&getASTContext().Idents.get("NULL")))
+      return " = NULL";
+  }
+  if (T->isEnumeralType())
+    return 0;
+  if (T->isScalarType())
+    return " = 0";
+  const CXXRecordDecl *RD = T->getAsCXXRecordDecl();
+  if (LangOpts.CPlusPlus0x && RD && !RD->hasUserProvidedDefaultConstructor())
+    return "{}";
+  if (T->isAggregateType())
+    return " = {}";
+  return 0;
+}