[Bug fortran/31463] New: gfortran prints no warning message when an unset return value is an array

[Bug fortran/31463] New: gfortran prints no warning message when an unset return value is an array

[michael dot a dot richmond at nasa dot gov]

When I compile the function listed below I receive no diagnostics. It should
say:

test.f90: In function 'test':
test.f90:1: warning: Function return value not set

FUNCTION test() RESULT(f)
REAL, DIMENSION(1) :: f
END FUNCTION test


-- 
           Summary: gfortran prints no warning message when an unset return
                    value is an array
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: michael dot a dot richmond at nasa dot gov


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31463

[Bug fortran/31463] gfortran prints no warning message when an unset return value is an array

[michael dot a dot richmond at nasa dot gov]

------- Comment #1 from michael dot a dot richmond at nasa dot gov  2007-04-03 18:45 -------
The following functions should produce a similar warning message:

function test97() result(ps)
character :: ps
end function test97

CHARACTER(*) FUNCTION test105()
i = LEN(test105)
END FUNCTION test105


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31463

[Bug fortran/31463] gfortran prints no warning message when an unset return value is an array

[fxcoudert at gcc dot gnu dot org]

-- 

fxcoudert at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |enhancement
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
           Keywords|                            |diagnostic
   Last reconfirmed|0000-00-00 00:00:00         |2007-04-18 06:51:53
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31463

[Bug fortran/31463] gfortran prints no warning message when an unset return value is an array

[dfranke at gcc dot gnu dot org]

------- Comment #2 from dfranke at gcc dot gnu dot org  2008-01-28 14:45 -------
Confirmed.

Interestingly:
$> cat pr31463.f90
FUNCTION test() RESULT(f)
REAL :: f                              ! removed DIMENSION statement
END FUNCTION test

$> gfortran-svn -g -Wall -c pr31463.f90
pr31463.f90:1.25:

FUNCTION test() RESULT(f)
                        1
Warning: Unused variable 'f' declared at (1)
pr31463.f90: In function 'test':
pr31463.f90:1: warning: Function return value not set
pr31463.f90:1: warning: control reaches end of non-void function

$> gfortran-svn -v
gcc version 4.3.0 20080125 (experimental)

However, the last three lines are issued from the middle-end. On general
agreement, we don't want this to happen.

I think, an additional attribute, e.g. 'is_function_result' should be added to
the symbol (if not otherwise flagged yet). Then, trans_decl.c
(generate_local_decl) could check for this flag, issue a warning and set
TREE_NO_WARNING to gag the middle-end.


-- 

dfranke at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dfranke at gcc dot gnu dot
                   |                            |org
   Last reconfirmed|2007-04-18 06:51:53         |2008-01-28 14:45:55
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31463

[Bug fortran/31463] [patch] inconsistent warnings if function return value is not set

[dfranke at gcc dot gnu dot org]

------- Comment #3 from dfranke at gcc dot gnu dot org  2008-01-29 01:26 -------
Mine. For patch, see URL above.


-- 

dfranke at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |dfranke at gcc dot gnu dot
                   |dot org                     |org
                URL|                            |http://gcc.gnu.org/ml/fortra
                   |                            |n/2008-01/msg00355.html
             Status|NEW                         |ASSIGNED
           Keywords|                            |patch
   Last reconfirmed|2008-01-28 14:45:55         |2008-01-29 01:26:18
               date|                            |
            Summary|gfortran prints no warning  |[patch] inconsistent
                   |message when an unset return|warnings if function return
                   |value is an array           |value is not set
   Target Milestone|---                         |4.4.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31463

[Bug fortran/31463] [patch] inconsistent warnings if function return value is not set

[burnus at gcc dot gnu dot org]

------- Comment #4 from burnus at gcc dot gnu dot org  2008-01-29 10:05 -------
Daniel's Patch: http://gcc.gnu.org/ml/fortran/2008-01/msg00355.html

Related PRs: PR 34296, PR 33950, and PR 28004.


-- 

burnus at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |burnus at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31463

[Bug fortran/31463] [patch] inconsistent warnings if function return value is not set

[dfranke at gcc dot gnu dot org]

------- Comment #5 from dfranke at gcc dot gnu dot org  2008-01-29 10:17 -------
> Related PRs: PR 34296, PR 33950, and PR 28004.

Tobias, thanks for the pointers! PRs 34296 and 33950 are (IMO) fixed by this
patch as well (see my comments there). The last one is not affected.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31463

[Bug fortran/31463] [patch] inconsistent warnings if function return value is not set

[dfranke at gcc dot gnu dot org]

------- Comment #6 from dfranke at gcc dot gnu dot org  2008-02-28 20:23 -------
Subject: Bug 31463

Author: dfranke
Date: Thu Feb 28 20:22:55 2008
New Revision: 132756

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=132756
Log:
gcc/fortran:
2008-02-28  Daniel Franke  <franke.daniel@gmail.com>

        PR fortran/31463
        PR fortran/33950
        PR fortran/34296
        * lang.opt: Added -Wreturn-type.
        * options.c (gfc_handle_option): Recognize -Wreturn-type.
        * trans-decl.c (gfc_trans_deferred_vars): Emit warnings for funtions
        where the result value is not set.
        (gfc_generate_function_code): Likewise.
        (generate_local_decl): Emit warnings for funtions whose RESULT
        variable is not set.

gcc/testsuite:
2008-02-28  Daniel Franke  <franke.daniel@gmail.com>

        PR fortran/31463
        PR fortran/33950
        PR fortran/34296
        * gfortran.dg/arrayio_11.f90: Fixed test.
        * gfortran.dg/arrayio_12.f90: Likewise.
        * gfortran.dg/module_read_1.f90: Added warning-directives.
        * gfortran.dg/pr32242.f90: Likewise.
        * gfortran.dg/result_in_spec_3.f90: Likewise.
        * gfortran.dg/use_12.f90: Likewise.
        * gfortran.dg/warn_function_without_result.f90 : New test.


Added:
    trunk/gcc/testsuite/gfortran.dg/warn_function_without_result.f90
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/lang.opt
    trunk/gcc/fortran/options.c
    trunk/gcc/fortran/trans-decl.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gfortran.dg/arrayio_11.f90
    trunk/gcc/testsuite/gfortran.dg/arrayio_12.f90
    trunk/gcc/testsuite/gfortran.dg/module_read_1.f90
    trunk/gcc/testsuite/gfortran.dg/pr32242.f90
    trunk/gcc/testsuite/gfortran.dg/result_in_spec_3.f90
    trunk/gcc/testsuite/gfortran.dg/use_12.f90


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31463

[Bug fortran/31463] [patch] inconsistent warnings if function return value is not set

[dfranke at gcc dot gnu dot org]

------- Comment #7 from dfranke at gcc dot gnu dot org  2008-02-28 20:25 -------
Fixed in trunk. Closing.


-- 

dfranke at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31463