re PR c++/71973 (c++ handles built-in functions inconsistently)

re PR c++/71973 (c++ handles built-in functions inconsistently)

gcc:
2016-11-21  Bernd Edlinger  <bernd.edlinger@hotmail.de>

	PR c++/71973
	* doc/invoke.texi (-Wno-builtin-declaration-mismatch): Document the
	new default-enabled warning..
	* builtin-types.def (BT_CONST_TM_PTR): New primitive type.
	(BT_PTR_CONST_STRING): Updated.
	(BT_FN_SIZE_STRING_SIZE_CONST_STRING_CONST_PTR): Removed.
	(BT_FN_SIZE_STRING_SIZE_CONST_STRING_CONST_TM_PTR): New function type.
	* builtins.def (DEF_TM_BUILTIN): Disable BOTH_P for TM builtins.
	(strftime): Update builtin function.
	* tree-core.h (TI_CONST_TM_PTR_TYPE): New enum value.
	* tree.h (const_tm_ptr_type_node): New type node.
	* tree.c (free_lang_data, build_common_tree_nodes): Initialize
	const_tm_ptr_type_node.

c-family:
2016-11-21  Bernd Edlinger  <bernd.edlinger@hotmail.de>

	PR c++/71973
	* c.opt (-Wbuiltin-declaration-mismatch): New warning.
	* c-common.c (c_common_nodes_and_builtins): Initialize
	const_tm_ptr_type_node.

c:
2016-11-21  Bernd Edlinger  <bernd.edlinger@hotmail.de>

	PR c++/71973
	* c-decl.c (diagnose_mismatched_decls): Use
	OPT_Wbuiltin_declaration_mismatch here too.

cp:
2016-11-21  Bernd Edlinger  <bernd.edlinger@hotmail.de>

	PR c++/71973
	* decl.c (duplicate_decls): Warn when a built-in function is redefined.
	Don't overload builtin functions with C++ functions.
	Handle const_tm_ptr_type_node like file_ptr_node.
	Copy the TREE_NOTHROW flag unmodified to the old decl.

lto:
2016-11-21  Bernd Edlinger  <bernd.edlinger@hotmail.de>

	PR c++/71973
	* lto-lang.c (lto_init): Assert const_tm_ptr_type_node is sane.

testsuite:
2016-11-21  Bernd Edlinger  <bernd.edlinger@hotmail.de>

	PR c++/71973
	* g++.dg/pr71973-1.C: New test.
	* g++.dg/pr71973-2.C: New test.
	* g++.dg/pr71973-3.C: New test.
	* g++.dg/lto/pr68811_0.C: Add -w to first lto-options.
	* g++.dg/lookup/extern-c-redecl4.C: Adjust test expectations.
	* g++.old-deja/g++.mike/p700.C: Add -Wno-builtin-declaration-mismatch
	to dg-options.
	* g++.old-deja/g++.other/realloc.C: Likewise.
	* g++.old-deja/g++.other/builtins10.C: Adjust test expectations.

From-SVN: r242662