re PR fortran/56667 (Syntax error causes misleading message: "Expected PARAMETER…

re PR fortran/56667 (Syntax error causes misleading message: "Expected PARAMETER symbol in complex constant")

2018-03-06  Steven G. Kargl  <kargl@gcc.gnu.org>

	PR fortran/56667
	* primary.c (match_sym_complex_part): Give the matcher for an implied
	do-loop a chance to run.

2018-03-06  Steven G. Kargl  <kargl@gcc.gnu.org>

	PR fortran/56667
	* gfortran.dg/implied_do_2.f90: New test.
	* gfortran.dg/coarray_8.f90: Update for new error message.

From-SVN: r258281

gcc/fortran/ChangeLog

+2018-03-06  Steven G. Kargl  <kargl@gcc.gnu.org>
+
+	PR fortran/56667
+	* primary.c (match_sym_complex_part): Give the matcher for an implied
+	do-loop a chance to run.
+
 2018-03-03  Harald Anlauf  <anlauf@gmx.de>
 
 	PR fortran/71085

gcc/fortran/primary.c

@@ -1248,8 +1248,22 @@ match_sym_complex_part (gfc_expr **result)
 
   if (sym->attr.flavor != FL_PARAMETER)
     {
-      gfc_error ("Expected PARAMETER symbol in complex constant at %C");
-      return MATCH_ERROR;
+      /* Give the matcher for implied do-loops a chance to run.  This yields
+	 a much saner error message for "write(*,*) (i, i=1, 6" where the 
+	 right parenthesis is missing.  */
+      char c;
+      gfc_gobble_whitespace ();
+      c = gfc_peek_ascii_char ();
+      if (c == '=' || c == ',')
+	{
+	  m = MATCH_NO;
+	}
+      else
+	{
+	  gfc_error ("Expected PARAMETER symbol in complex constant at %C");
+	  m = MATCH_ERROR;
+	}
+      return m;
     }
 
   if (!sym->value)

gcc/testsuite/ChangeLog

+2018-03-06  Steven G. Kargl  <kargl@gcc.gnu.org>
+
+	PR fortran/56667
+	* gfortran.dg/implied_do_2.f90: New test.
+	* gfortran.dg/coarray_8.f90: Update for new error message.
+
 2018-03-06  Jakub Jelinek  <jakub@redhat.com>
 
 	PR inline-asm/84683

gcc/testsuite/gfortran.dg/coarray_8.f90

@@ -145,7 +145,7 @@ end module mmm4
 
 subroutine tfgh()
   integer :: i(2)
-  DATA i/(i, i=1,2)/ ! { dg-error "Expected PARAMETER symbol" }
+  DATA i/(i, i=1,2)/ ! { dg-error "Syntax error in DATA" }
   do i = 1, 5 ! { dg-error "cannot be an array" }
   end do ! { dg-error "Expecting END SUBROUTINE" }
 end subroutine tfgh
@@ -153,7 +153,7 @@ end subroutine tfgh
 subroutine tfgh2()
   integer, save :: x[*]
   integer :: i(2)
-  DATA i/(x, x=1,2)/ ! { dg-error "Expected PARAMETER symbol" }
+  DATA i/(x, x=1,2)/ ! { dg-error "Syntax error in DATA" }
   do x = 1, 5 ! { dg-error "cannot be a coarray" }
   end do ! { dg-error "Expecting END SUBROUTINE" }
 end subroutine tfgh2

gcc/testsuite/gfortran.dg/implied_do_2.f90

+! { dg-do compile }
+! PR fortran/56667
+program error_message
+   implicit none
+   integer :: ir
+   write(*,*) ( ir, ir = 1,10    ! { dg-error "Expected a right parenthesis" }
+end program error_message