C99 DR #316 implies that the function parameter types that are known
only from a function definition (that does not have a prototype) are
only used to determine the compatible with other declarations of that
same function. In particular, when referencing the function we pretend
as if it does not have a prototype. Implement this behavior, which
fixes PR3626.




git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@65460 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index abb5e40..c312195 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -334,7 +334,8 @@
   FunctionDecl *New = FunctionDecl::Create(Context,
                                            Context.getTranslationUnitDecl(),
                                            Loc, II, R,
-                                           FunctionDecl::Extern, false);
+                                           FunctionDecl::Extern, false,
+                                           /*hasPrototype=*/true);
   New->setImplicit();
 
   // Create Decl objects for each parameter, adding them to the
@@ -1736,6 +1737,7 @@
       // code path.
       NewFD = FunctionDecl::Create(Context, DC, D.getIdentifierLoc(),
                                    Name, R, SC, isInline, 
+                                   /*hasPrototype=*/true,
                                    // FIXME: Move to DeclGroup...
                                    D.getDeclSpec().getSourceRange().getBegin());
       InvalidDecl = true;
@@ -1765,6 +1767,10 @@
     NewFD = FunctionDecl::Create(Context, DC,
                                  D.getIdentifierLoc(),
                                  Name, R, SC, isInline, 
+                                 /*hasPrototype=*/
+                                   (getLangOptions().CPlusPlus ||
+                                    (D.getNumTypeObjects() &&
+                                     D.getTypeObject(0).Fun.hasPrototype)),
                                  // FIXME: Move to DeclGroup...
                                  D.getDeclSpec().getSourceRange().getBegin());
   }