Don't allow calls to functions marked "unavailable". There's more work

to do in this area, since there are other places that reference
FunctionDecls.

Don't allow "overloadable" functions (in C) to be declared without a
prototype.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@64897 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 19 insertions, 3 deletions

diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 55e2a92476..0543b0adc6 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -1763,11 +1763,27 @@ Sema::ActOnFunctionDeclarator(Scope* S, Declarator& D, DeclContext* DC,
     OverloadedFunctionDecl::function_iterator MatchedDecl;
 
     if (!getLangOptions().CPlusPlus &&
-        AllowOverloadingOfFunction(PrevDecl, Context))
+        AllowOverloadingOfFunction(PrevDecl, Context)) {
       OverloadableAttrRequired = true;
 
-    if (!AllowOverloadingOfFunction(PrevDecl, Context) || 
-        !IsOverload(NewFD, PrevDecl, MatchedDecl)) {
+      // Functions marked "overloadable" must have a prototype (that
+      // we can't get through declaration merging).
+      if (!R->getAsFunctionTypeProto()) {
+        Diag(NewFD->getLocation(), diag::err_attribute_overloadable_no_prototype)
+          << NewFD;
+        InvalidDecl = true;
+        Redeclaration = true;
+
+        // Turn this into a variadic function with no parameters.
+        R = Context.getFunctionType(R->getAsFunctionType()->getResultType(),
+                                    0, 0, true, 0);
+        NewFD->setType(R);
+      }
+    }
+
+    if (PrevDecl && 
+        (!AllowOverloadingOfFunction(PrevDecl, Context) || 
+         !IsOverload(NewFD, PrevDecl, MatchedDecl))) {
       Redeclaration = true;
       Decl *OldDecl = PrevDecl;