2010-04-27  Manuel López-Ibáñez  <manu@gcc.gnu.org>
	    Jan Hubicka <hubicka@ucw.cz>

	* doc/invoke.texi (-Wsuggest-attribute=const,
	-Wsuggest-attribute=pure): Document.
	* ipa-pure-const.c: Include toplev.h, intl.h and opts.h.
	(function_always_visible_to_compiler_p,
	suggest_attribute, warn_function_pure, warn_function_const):
	New functions.
	(check_call): Improve debug info.
	(analyze_function): Do not check availability.
	(add_new_function): Check availability.
	(propagate): Output warnings.
	(skip_function_for_local_pure_const): New function.
	(local_pure_const): Use it; output warnings.
	* common.opt (Wsuggest-attribute=const,
	Wsuggest-attribute=pure): New.

testsuite/
	* gcc.dg/pure-2.c: New testcase.
	* gcc.dg/const-1.c: New testcase.

Co-Authored-By: Jan Hubicka <hubicka@ucw.cz>

From-SVN: r158803