2007-08-14  Ed Schonberg  <schonberg@adacore.com>
	    Robert Dewar  <dewar@adacore.com>
	    Javier Miranda  <miranda@adacore.com>
	    Gary Dismukes  <dismukes@adacore.com>

	* einfo.ads, einfo.adb: Create a limited view of an incomplete type,
	to make treatment of limited views uniform for all visible declarations
	in a limited_withed package.
	Improve warnings for in out parameters
	(Set_Related_Interaface/Related_Interface): Allow the use of this
	attribute with constants.
	(Write_Field26_Name): Handle attribute Related_Interface in constants.
	Warn on duplicate pragma Preelaborable_Initialialization

	* sem_ch6.ads, sem_ch6.adb (Analyze_Subprogram_Body): Force the
	generation of a freezing node to ensure proper management of null
	excluding access types in the backend.
	(Create_Extra_Formals): Test base type of the formal when checking for
	the need to add an extra accessibility-level formal. Pass the entity E
	on all calls to Add_Extra_Formal (rather than Scope (Formal) as was
	originally being done in a couple of cases), to ensure that the
	Extra_Formals list gets set on the entity E when the first entity is
	added.
	(Conforming_Types): Add missing calls to Base_Type to the code that
	handles anonymous access types. This is required to handle the
	general case because Process_Formals builds internal subtype entities
	to handle null-excluding access types.
	(Make_Controlling_Function_Wrappers): Create wrappers for constructor
	functions that need it, even when not marked Requires_Overriding.
	Improve warnings for in out parameters
	(Analyze_Function_Return): Warn for disallowed null return
	Warn on return from procedure with unset out parameter
	Ensure consistent use of # in error messages
	(Check_Overriding_Indicator): Add in parameter Is_Primitive.
	(Analyze_Function_Return): Move call to Apply_Constraint_Check before
	the implicit conversion of the expression done for anonymous access
	types. This is required to generate the code of the null excluding
	check (if required).

	* sem_warn.ads, sem_warn.adb (Check_References.Publicly_Referenceable):
	A formal parameter is never publicly referenceable outside of its body.
	(Check_References): For an unreferenced formal parameter in an accept
	statement, use the same warning circuitry as for subprogram formal
	parameters.
	(Warn_On_Unreferenced_Entity): New subprogram, taken from
	Output_Unreferenced_Messages, containing the part of that routine that
	is now reused for entry formals as described above.
	(Goto_Spec_Entity): New function
	(Check_References): Do not give IN OUT warning for dispatching operation
	Improve warnings for in out parameters
	(Test_Ref): Check that the entity is not undefinite before calling
	Scope_Within, in order to avoid infinite loops.
	Warn on return from procedure with unset out parameter
	Improved warnings for unused variables

From-SVN: r127415