Downgrade complaints about calling unavailable functions to a warning

(as GCC does), except when we've performed overload resolution and
found an unavailable function: in this case, we actually error.

Merge the checking of unavailable functions with the checking for
deprecated functions. This unifies a bit of code, and makes sure that
we're checking for unavailable functions in the right places. Also,
this check can cause an error. We may, eventually, want an option to
make "unavailable" warnings into errors.

Implement much of the logic needed for C++0x deleted functions, which
are effectively the same as "unavailable" functions (but always cause
an error when referenced). However, we don't have the syntax to
specify deleted functions yet :)

llvm-svn: 64955

1 files changed, 15 insertions, 6 deletions

diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index d5d2b08130f..ea59b644c90 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -473,6 +473,13 @@ bool Sema::FindAllocationOverload(SourceLocation StartLoc, SourceRange Range,
       << Name << Range;
     PrintOverloadCandidates(Candidates, /*OnlyViable=*/true);
     return true;
+
+  case OR_Deleted:
+    Diag(StartLoc, diag::err_ovl_deleted_call)
+      << Best->Function->isDeleted()
+      << Name << Range;
+    PrintOverloadCandidates(Candidates, /*OnlyViable=*/true);
+    return true;
   }
   assert(false && "Unreachable, bad result from BestViableFunction");
   return true;
@@ -775,20 +782,22 @@ Sema::PerformImplicitConversion(Expr *&From, QualType ToType,
     break;
 
   case ICK_Array_To_Pointer:
+    FromType = Context.getArrayDecayedType(FromType);
+    ImpCastExprToType(From, FromType);
+    break;
+
+  case ICK_Function_To_Pointer:
     if (FromType->isOverloadType()) {
       FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(From, ToType, true);
       if (!Fn)
         return true;
 
+      if (DiagnoseUseOfDecl(Fn, From->getSourceRange().getBegin()))
+        return true;
+
       FixOverloadedFunctionReference(From, Fn);
       FromType = From->getType();
-    } else {
-      FromType = Context.getArrayDecayedType(FromType);
     }
-    ImpCastExprToType(From, FromType);
-    break;
-
-  case ICK_Function_To_Pointer:
     FromType = Context.getPointerType(FromType);
     ImpCastExprToType(From, FromType);
     break;