Issue -Wempty-body warnings for else blocks

This looks like it was just an oversight.

Fixes http://llvm.org/pr35319

llvm-svn: 318456

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -8090,6 +8090,8 @@ def err_switch_incomplete_class_type : Error<
 
 def warn_empty_if_body : Warning<
   "if statement has empty body">, InGroup<EmptyBody>;
+def warn_empty_else_body : Warning<
+  "else clause has empty body">, InGroup<EmptyBody>;
 def warn_empty_for_body : Warning<
   "for loop has empty body">, InGroup<EmptyBody>;
 def warn_empty_range_based_for_body : Warning<

clang/lib/Sema/SemaStmt.cpp

@@ -527,7 +527,9 @@ Sema::ActOnIfStmt(SourceLocation IfLoc, bool IsConstexpr, Stmt *InitStmt,
                        CondExpr->getExprLoc()))
     CommaVisitor(*this).Visit(CondExpr);
 
-  if (!elseStmt)
+  if (elseStmt)
+    DiagnoseEmptyStmtBody(ElseLoc, elseStmt, diag::warn_empty_else_body);
+  else
     DiagnoseEmptyStmtBody(CondExpr->getLocEnd(), thenStmt,
                           diag::warn_empty_if_body);
 

clang/test/SemaCXX/warn-empty-body.cpp

@@ -238,6 +238,26 @@ void test6(int x, int y) {
   }
 }
 
+void test_if_else(int x) {
+  if (x); // expected-warning{{if statement has empty body}} expected-note{{separate line}}
+
+  if (x)
+    ; // no-warning
+
+  if (x)
+    ; // no-warning
+  else
+    ; // no-warning
+
+  if (x)
+    ; // no-warning
+  else; // expected-warning{{else clause has empty body}} expected-note{{separate line}}
+
+  if (x)
+    ; // no-warning
+  else EMPTY(x); // no-warning
+}
+
 void test_errors(int x) {
   if (1)
     aa; // expected-error{{use of undeclared identifier}}