2019-08-15  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/91443
	* frontend-passes.c (check_externals_expr): New function.
	(check_externals_code): New function.
	(gfc_check_externals): New function.
	* gfortran.h (debug): Add prototypes for gfc_symbol * and
	gfc_expr *.
	(gfc_check_externals): Add prototype.
	* interface.c (compare_actual_formal): Do not complain about
	alternate returns if the formal argument is optional.
	(gfc_procedure_use): Handle cases when an error has been issued
	previously.  Break long line.
	* parse.c (gfc_parse_file): Call gfc_check_externals for all
	external procedures.
	* resolve.c (resolve_global_procedure): Remove checking of
	argument list.

2019-08-15  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/91443
	* gfortran.dg/argument_checking_19.f90: New test.
	* gfortran.dg/altreturn_10.f90: Change dg-warning to dg-error.
	* gfortran.dg/dec_union_11.f90: Add -std=legacy.
	* gfortran.dg/hollerith8.f90: Likewise. Remove warning for
	Hollerith constant.
	* gfortran.dg/integer_exponentiation_2.f90: New subroutine gee_i8;
	use it to avoid type mismatches.
	* gfortran.dg/pr41011.f: Add -std=legacy.
	* gfortran.dg/whole_file_1.f90: Change warnings to errors.
	* gfortran.dg/whole_file_2.f90: Likewise.

From-SVN: r274551