[Bug fortran/28039] Warn when ignoring extra characters in the format specification

["bdavis at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org>]

------- Comment #10 from bdavis at gcc dot gnu dot org  2009-12-30 04:25 -------
let's give this a try:

Index: gcc/gcc/testsuite/gfortran.dg/fmt_with_extra.f
===================================================================
--- gcc/gcc/testsuite/gfortran.dg/fmt_with_extra.f      (revision 155511)
+++ gcc/gcc/testsuite/gfortran.dg/fmt_with_extra.f      (working copy)
@@ -4,5 +4,25 @@
        implicit none
        real :: r
        r = 1.0
-       write(*,'(a),f)') 'Hello', r   ! { dg-warning "Extraneous characters in
format at" "PR28039" { xfail *-*-* } }
+       write(*,'(a),f)') 'Hello', r   ! { dg-warning "Extraneous characters in
format at" }
        end
+! Below routine was also submitted by tobias.burnus@physik.fu-berlin.de
+! It showed up some problems with the initial implementation of this
+! feature.
+! This routine should compile without complaint or warning.
+      SUBROUTINE rw_inp()
+      CHARACTER(len=100) :: line
+      integer :: i5
+      character(100), parameter :: subchapter =
+     &        '(79("-"),/,5("-")," ",A,/,79("-"),/)'
+      i5 = 1
+
+      READ(*,FMT="(4x,a)") line
+ 7182 FORMAT (a3)
+ 7130 FORMAT (i3)
+
+      WRITE (6,'(//'' icorr is not correctly transferred.  icorr='',i5)
+     &    ') 42
+
+      write(*,subchapter) 'test'
+      END SUBROUTINE rw_inp
Index: gcc/gcc/fortran/io.c
===================================================================
--- gcc/gcc/fortran/io.c        (revision 155511)
+++ gcc/gcc/fortran/io.c        (working copy)
@@ -850,11 +850,11 @@
       if (u != FMT_POSINT)
        {
          format_locus.nextc += format_string_pos;
-         gfc_error_now ("Positive width required in format "
+         gfc_error ("Positive width required in format "
                         "specifier %s at %L", token_to_string (t),
                         &format_locus);
          saved_token = u;
-         goto finished;
+         goto fail;
        }

       u = format_lex ();
@@ -866,11 +866,11 @@
          format_locus.nextc += format_string_pos;
          if (gfc_option.warn_std != 0)
            {
-             gfc_error_now ("Period required in format "
+             gfc_error ("Period required in format "
                             "specifier %s at %L", token_to_string (t),
                             &format_locus);
              saved_token = u;
-             goto finished;
+              goto fail;
            }
          else
            gfc_warning ("Period required in format "
@@ -970,11 +970,11 @@
          gfc_warning ("The H format specifier at %L is"
                       " a Fortran 95 deleted feature", &format_locus);
        }
-
       if (mode == MODE_STRING)
        {
          format_string += value;
          format_length -= value;
+          format_string_pos += repeat;
        }
       else
        {
@@ -1152,6 +1152,8 @@
 static gfc_try
 check_format_string (gfc_expr *e, bool is_input)
 {
+  gfc_try rv;
+  int i;
   if (!e || e->ts.type != BT_CHARACTER || e->expr_type != EXPR_CONSTANT)
     return SUCCESS;

@@ -1162,8 +1164,20 @@
      format string that has been calculated, but that's probably not worth the
      effort.  */
   format_locus = e->where;
-
-  return check_format (is_input);
+  rv = check_format (is_input);
+  /* check for extraneous characters at the end of an otherwise valid format
+     string, like '(A10,I3)F5'
+     start at the end and move back to the last character processed,
+     spaces are OK */
+  if (rv == SUCCESS && e->value.character.length > format_string_pos)
+    for (i=e->value.character.length-1;i>format_string_pos-1;i--)
+      if (e->value.character.string[i] != ' ')
+        {
+          format_locus.nextc += format_length + 1; 
+          gfc_warning ("Extraneous characters in format at %L",
&format_locus); 
+          break;
+        }
+  return rv;
 }


will submit an official patch after doing regtesting against a clean tree.
since we are 'stabilizing' for 4.5, it might be a while for this is committed
so i am posting it here so the work is not lost.


--bud


-- 

bdavis at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|REOPENED                    |ASSIGNED
   Last reconfirmed|2009-08-22 23:21:18         |2009-12-30 04:25:49
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28039