sem_ch10.adb (Check_Redundant_Withs): New procedure in Analyze_Compilation_Unit.

2006-02-13  Hristian Kirtchev  <kirtchev@adacore.com>
	    Ed Schonberg  <schonberg@adacore.com>
	    Gary Dismukes  <dismukes@adacore.com>

	* sem_ch10.adb (Check_Redundant_Withs): New procedure in
	Analyze_Compilation_Unit.
	Detect and warn on redundant with clauses detected in a package spec
	and/or body when -gnatwr is used.
	(Analyze_Context): Analyze config pragmas before other items
	(Install_Context_Items): Don't analyze config pragmas here
	(Install_Limited_Withed_Unit): Set limited entity of package in
	with_clause so that cross-reference information or warning messages on
	unused packages can be properly generated
	(Is_Visible_Through_Renamings): Return false if the limited_with_clause
	has Error_Posted set. Prevent infinite loops in illegal programs.
	(Check_Private_Child_Unit): Move test for a nonprivate with clause down
	to the point of the error test requiring the current unit to be private.
	This ensures that private with clauses are not exempted from the basic
	checking for being a descendant of the same library unit parent as a
	withed private descendant unit.
	(Check_Private_Limited_Withed_Unit): Revise the checking algorithm to
	handle private with clauses properly, as well as to account for cases
	where the withed unit is a public descendant of a private ancestor
	(in which case the current unit must be a descendant of the private
	ancestor's parent). The spec comments were updated accordingly. Also,
	the old error message in this subprogram was replaced with error
	messages that mirror the errors tested and reported by
	Check_Private_Child_Unit.
	Parameter and variable names improved for readability.
	(Install_Limited_Context_Clauses): Remove test for a withed unit being
	private as the precondition for calling
	Check_Private_Limited_Withed_Unit since that subprogram has been
	revised to test public units as well as private units.

From-SVN: r111090