When a declaration of a function is missing an exception specification
that was present in a prior declaration, emit a warning rather than a
hard error (which we did before, and still do with mismatched
exception specifications). Moreover, provide a fix-it hint with the
throw() clause that should be added, e.g.,

t.C:10:7: warning: 'operator new' is missing exception specification
      'throw(std::bad_alloc)'
void *operator new(unsigned long sz)
      ^
                                     throw(std::bad_alloc)

As part of this, disable the warning when we're missing an exception
specification on operator new, operator new[], operator delete, or
operator delete[] when exceptions are turned off (-fno-exceptions).

Fixes PR5957.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@99388 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/Sema.h b/lib/Sema/Sema.h
index 85fa4f1..ba6d38f 100644
--- a/lib/Sema/Sema.h
+++ b/lib/Sema/Sema.h
@@ -728,6 +728,7 @@
       const PartialDiagnostic &DiagID, const PartialDiagnostic & NoteID,
       const FunctionProtoType *Old, SourceLocation OldLoc,
       const FunctionProtoType *New, SourceLocation NewLoc,
+      bool *MissingExceptionSpecification = 0,
       bool *MissingEmptyExceptionSpecification = 0);
   bool CheckExceptionSpecSubset(
       const PartialDiagnostic &DiagID, const PartialDiagnostic & NoteID,