[Bug fortran/34227] New: initialized symbol in common: Better error message

[Bug fortran/34227] New: initialized symbol in common: Better error message

[burnus at gcc dot gnu dot org]

character(len=3) :: emname(nmin)=(/'bar','baz'/)
 common/nmstr/emname
end

currently gfortran prints:

   Error: Previously initialized symbol 'emname' in COMMON block 'nmstr' at (1)

If find the error message of NAG f95 better, which mentions that BLOCK DATA can
be used:

   Error: EMNAME has been initialised - can only be COMMON in BLOCK DATA


-- 
           Summary: initialized symbol in common: Better error message
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Keywords: diagnostic
          Severity: enhancement
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: burnus at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34227

[Bug fortran/34227] initialized symbol in COMMON: Missing checks

[burnus at gcc dot gnu dot org]

------- Comment #1 from burnus at gcc dot gnu dot org  2007-11-25 21:20 -------
That error message disappears with the patch to PR 33152.

>From "5.5.2.4 Differences between named common and blank common":

"A data object in a named common block may be initially defined by means of a
DATA statement or type declaration statement in a block data program unit
(11.3), but objects in blank common shall not be initially defined."

The initialization of common blocks outside block-data program units is
supported by several compilers and thus one can consider allowing it for
-std=gnu.

program main
 implicit none
 integer, parameter:: nmin = 2
 character(len=3) :: emname(nmin)=(/'bar','baz'/)
 common/nmstr/emname
end program main

As NAG f95 kindly writes:
  EMNAME has been initialised - can only be COMMON in BLOCK DATA

ifort -stand f95 diagnoses:
  In Fortran 95, this DATA statement object cannot appear in either a blank
COMMON block or a named COMMON block.
but I like the mentioning of DATA BLOCK more.

Same, but with DATA:

program main
 implicit none
 integer, parameter:: nmin = 2
 character(len=3) :: emname(nmin)
 data emname/ 'bar','baz' /
 common/nmstr/emname
end program main


And for blank commons:

program main
 implicit none
 integer, parameter:: nmin = 2
 character(len=3) :: emname(nmin) = [ 'Aaa','aaa']
 common//emname
end program main

gfortran (w/o patch):
  Previously initialized symbol 'emname' in blank COMMON block at (1)

Similarly to above, gfortran misses the initialization with DATA. (With the
patch, neither diagnosed):
program main
 implicit none
 integer, parameter:: nmin = 2
 character(len=3) :: emname(nmin)
 data emname/ 'bar','baz' /
 common//emname
end program main

Note: For blank commons, one should not point to BLOCK DATA as they are not
allowed there. gfortran (patched and unpatched) correctly diagnoses (default
options):

  Warning: BLOCK DATA unit cannot contain blank COMMON


-- 

burnus at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|enhancement                 |normal
           Keywords|                            |accepts-invalid
            Summary|initialized symbol in       |initialized symbol in
                   |common: Better error message|COMMON: Missing checks


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34227

[Bug fortran/34227] initialized symbol in COMMON: Missing checks

[jvdelisle at gcc dot gnu dot org]

------- Comment #2 from jvdelisle at gcc dot gnu dot org  2007-11-28 01:01 -------
Subject: Bug 34227

Author: jvdelisle
Date: Wed Nov 28 01:00:50 2007
New Revision: 130483

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=130483
Log:
2007-11-27  Jerry DeLisle  <jvdelisle@gcc.gnu.org>

        PR fortran/34227
        * match.c (gfc_match_common): Add additional check for BLOCK DATA.

Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/match.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34227

[Bug fortran/34227] initialized symbol in COMMON: Missing checks

[jvdelisle at gcc dot gnu dot org]

------- Comment #3 from jvdelisle at gcc dot gnu dot org  2007-11-28 01:09 -------
Subject: Bug 34227

Author: jvdelisle
Date: Wed Nov 28 01:09:35 2007
New Revision: 130486

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=130486
Log:
2007-11-27  Jerry DeLisle  <jvdelisle@gcc.gnu.org>

        PR fortran/34227
        * gfortran.dg/blockdata_5.f90: New test.
        * gfortran.dg/blockdata_6.f90: New test.

Added:
    trunk/gcc/testsuite/gfortran.dg/blockdata_5.f90
    trunk/gcc/testsuite/gfortran.dg/blockdata_6.f90
Modified:
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34227

[Bug fortran/34227] initialized symbol in COMMON: Missing checks

[jvdelisle at gcc dot gnu dot org]

------- Comment #4 from jvdelisle at gcc dot gnu dot org  2007-11-28 04:26 -------
Fixed on trunk


-- 

jvdelisle at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34227