2007-08-14 Robert Dewar <dewar@adacore.com>

2007-08-14  Robert Dewar  <dewar@adacore.com>
	    Ed Schonberg  <schonberg@adacore.com>

	* sem_ch11.adb: Improved warnings for unused variables

	* sem_ch3.ads, sem_ch3.adb (Build_Derived_Record_Type): If the ancestor
	is a synchronized interface, the derived type is limited.
	(Analyze_Object_Declaration): Mark the potential coextensions in the
	definition and expression of an object declaration node.
	(Build_Derived_Type): For the completion of a private type declaration
	with a derived type declaration, chain the parent type's representation
	items to the last representation item of the derived type (not the
	first one) if they are not present already.
	(Analyze_Object_Declaration, Constant_Redeclaration): Allow incomplete
	object declaration of forward references to tags.
	(Access_Subprogram_Declaration): In Ada2005, anonymous access to
	subprogram types can appear as access discriminants of synchronized
	types.
	(OK_For_Limited_Init_In_05): The initialization is legal is it is a call
	given in prefixed form as a selected component.
	(Process_Discriminants): If not all discriminants have defaults, place
	error message on a default that is present.
	(Analyze_Private_Extension_Declaration): Diagnose properly an attempt to
	extend a synchronized tagged type.
	Improved warnings for unused variables
	(Is_Visible_Component): Fix a visibility hole on a component inherited
	by a private extension when parent is itself declared as a private
	extension, and the derivation is in a child unit.
	(Find_Hidden_Interface): Move spec from the package body.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@127426 138bc75d-0d04-0410-961f-82ee72b054a4