[Bug fortran/24886] New: another runtime error goes undetected

[Bug fortran/24886] New: another runtime error goes undetected

[uttamp at us dot ibm dot com]

Following code should print the runtime error, shouldn't it? This test is taken
from http://ftp.cac.psu.edu/pub/ger/fortran/test

$ cat test.f90
        subroutine foo(y)
           character(len=20) :: y
           y = 'hello world'
        end

        program test
           character(len=10) :: x
           call foo(x)
           write(*,*) 'X=',x
           pause
        end

$ gfortran test.f90
$./a.out
X=hello worl
PAUSE
To resume execution, type go.  Other input will terminate the job.
go
RESUMED


-- 
           Summary: another runtime error goes undetected
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: uttamp at us dot ibm dot com
 GCC build triplet: powerpc64-linux
  GCC host triplet: powerpc64-linux
GCC target triplet: powerpc64-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24886

[Bug fortran/24886] another runtime error goes undetected

[fxcoudert at gcc dot gnu dot org]

------- Comment #1 from fxcoudert at gcc dot gnu dot org  2005-11-16 15:00 -------
What kind of runtime error would you think is appropriate? I don't see where
the problem is.


-- 

fxcoudert at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24886

[Bug fortran/24886] another runtime error goes undetected

[uttamp at us dot ibm dot com]

------- Comment #2 from uttamp at us dot ibm dot com  2005-11-16 17:33 -------
Any error which indicates something like, "dummy argument defined to be larger
than actual argument.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24886

[Bug fortran/24886] another runtime error goes undetected

[pinskia at gcc dot gnu dot org]

------- Comment #3 from pinskia at gcc dot gnu dot org  2006-01-03 16:59 -------
Not PPC specific.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
  GCC build triplet|powerpc64-linux             |
   GCC host triplet|powerpc64-linux             |
 GCC target triplet|powerpc64-linux             |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24886

[Bug fortran/24886] another runtime error goes undetected

[jvdelisle at gcc dot gnu dot org]

------- Comment #4 from jvdelisle at gcc dot gnu dot org  2006-01-04 03:25 -------
This is not a bug.  gfortran behavior is identical to ifort.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24886

[Bug fortran/24886] another runtime error goes undetected

[pault at gcc dot gnu dot org]

------- Comment #5 from pault at gcc dot gnu dot org  2006-01-11 09:07 -------
(In reply to comment #4)
> This is not a bug.  gfortran behavior is identical to ifort.
> 
Actually, it is quite specifically NOT permitted by the standard. To quote
12.4.1.1:

"If a scalar dummy argument is of type default character, the length len of the
dummy argument shall be less than or equal to the length of the actual
argument.  The dummy argument becomes associated with the leftmost len
characters of the actual argument.  If an array dummy argument is of type
default character, the restriction on the length is for the entire array and
not for each array element."

The reason for this is obvious enough; try writing beyond len and you will
eventually get a seg fault.

Uttam is quite correct to pick this out as a bug, although I am not sure that
we want a runtime error, except when -fbounds-check is active.  This could be
implemented, with advantage in trans-expr(gfc_conv_function_call) by copying
over some of the code from trans-array.c.

As it happens, in building a fix for PRs 20881, 23308 & 25710, I am about to
add "same file" argument checking, which is why I encountered this PR.  It will
fix Uttam's testcase but not the case where subroutine foo is truly external.


-- 

pault at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pault at gcc dot gnu dot org
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2006-01-11 09:07:40
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24886

[Bug fortran/24886] another runtime error goes undetected

[uttamp at us dot ibm dot com]

------- Comment #6 from uttamp at us dot ibm dot com  2006-01-11 22:02 -------
Subject: Re:  another runtime error goes undetected

On Wed, 2006-01-11 at 09:07 +0000, pault at gcc dot gnu dot org wrote:
> 
> ------- Comment #5 from pault at gcc dot gnu dot org  2006-01-11 09:07 -------
> (In reply to comment #4)
> > This is not a bug.  gfortran behavior is identical to ifort.
> > 
> Actually, it is quite specifically NOT permitted by the standard. To quote
> 12.4.1.1:
> 
> "If a scalar dummy argument is of type default character, the length len of the
> dummy argument shall be less than or equal to the length of the actual
> argument.  The dummy argument becomes associated with the leftmost len
> characters of the actual argument.  If an array dummy argument is of type
> default character, the restriction on the length is for the entire array and
> not for each array element."
> 
> The reason for this is obvious enough; try writing beyond len and you will
> eventually get a seg fault.
> 
> Uttam is quite correct to pick this out as a bug, although I am not sure that
> we want a runtime error, except when -fbounds-check is active.  This could be
> implemented, with advantage in trans-expr(gfc_conv_function_call) by copying
> over some of the code from trans-array.c.

Compile time check will be much better fix than the runtime.

> 
> As it happens, in building a fix for PRs 20881, 23308 & 25710, I am about to
> add "same file" argument checking, which is why I encountered this PR.  It will
> fix Uttam's testcase but not the case where subroutine foo is truly external.
> 

- Uttam


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24886

[Bug fortran/24886] different character length in actual and formal argument not detected

[burnus at gcc dot gnu dot org]

------- Comment #7 from burnus at gcc dot gnu dot org  2007-06-29 22:09 -------
[Compile-time checking]

I think this was fixed a while ago - at least for contained procedures. If not
it is then definitely fixed (for contained procedures) by my patch for PR30940:

"Character length of actual argument shorter than of dummy argument 'y' (10/20)
at (1)"

To get it working with the original example, we need whole-file checking which
is planned but not implemented.

Run-time checking would be nice too.


-- 

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=24886

[Bug fortran/24886] different character length in actual and formal argument not detected

[domob at gcc dot gnu dot org]

------- Comment #8 from domob at gcc dot gnu dot org  2009-01-03 19:08 -------
Runtime checking is PR 37746, BTW, I'm working on it and have a pending patch. 
Would this fix this bug or should we wait for the whole-file checking?


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24886

[Bug fortran/24886] different character length in actual and formal argument not detected

[pault at gcc dot gnu dot org]

------- Comment #9 from pault at gcc dot gnu dot org  2009-03-30 19:35 -------
Subject: Bug 24886

Author: pault
Date: Mon Mar 30 19:35:14 2009
New Revision: 145314

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=145314
Log:
2009-03-30  Paul Thomas  <pault@gcc.gnu.org>

        PR fortran/22571
        PR fortran/26227
        PR fortran/24886
        * symbol.c : Add gfc_global_ns_list.
        * decl.c (add_global_entry): Set the namespace ('ns') field.
        * gfortran.h : Add the resolved field to gfc_namespace. Add the
        namespace ('ns') field to gfc_gsymbol.  Add flag_whole_file to
        gfc_option_t.  Add the prototype for gfc_free_dt_list.
        * lang.opt : Add the whole-file option.
        * invoke.texi : Document the whole-file option.
        * resolve.c (resolve_global_procedure): If the fwhole-file
        option is set, reorder gsymbols to ensure that translation is
        in the right order.  Resolve the gsymbol's namespace if that
        has not occurred and then check interfaces.
        (resolve_function): Move call to resolve_global_procedure.
        (resolve_call): The same.
        (resolve_codes): Store the current labels_obstack.
        (gfc_resolve) : Return if the namespace is already resolved.
        trans-decl.c (gfc_get_extern_function_decl): If the whole_file
        option is selected, use the backend_decl of a gsymbol, if it is
        available.
        parse.c (add_global_procedure, add_global_program): If the flag
        whole-file is set, add the namespace to the gsymbol.
        (gfc_parse_file): On -fwhole-file, put procedure namespaces on
        the global namespace list.  Rearrange to do resolution of all
        the procedures in a file, followed by their translation.
        * options.c (gfc_init_options): Add -fwhole-file.
        (gfc_handle_option): The same.

2009-03-30  Paul Thomas  <pault@gcc.gnu.org>

        PR fortran/22571
        * gfortran.dg/whole_file_1.f90: New test.
        PR fortran/26227
        * gfortran.dg/whole_file_2.f90: New test.
        * gfortran.dg/whole_file_3.f90: New test.
        PR fortran/24886
        * gfortran.dg/whole_file_4.f90: New test.


Added:
    trunk/gcc/testsuite/gfortran.dg/whole_file_1.f90
    trunk/gcc/testsuite/gfortran.dg/whole_file_2.f90
    trunk/gcc/testsuite/gfortran.dg/whole_file_3.f90
    trunk/gcc/testsuite/gfortran.dg/whole_file_4.f90
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/decl.c
    trunk/gcc/fortran/gfortran.h
    trunk/gcc/fortran/invoke.texi
    trunk/gcc/fortran/lang.opt
    trunk/gcc/fortran/options.c
    trunk/gcc/fortran/parse.c
    trunk/gcc/fortran/resolve.c
    trunk/gcc/fortran/symbol.c
    trunk/gcc/fortran/trans-array.c
    trunk/gcc/fortran/trans-decl.c
    trunk/gcc/testsuite/ChangeLog


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24886

[Bug fortran/24886] different character length in actual and formal argument not detected

[dfranke at gcc dot gnu dot org]

------- Comment #10 from dfranke at gcc dot gnu dot org  2009-04-10 21:35 -------
With the commit in comment #9 we get:

$> gfortran-svn -fwhole-file -Wall pr24886.f
[...]
pr24886.f:8.20:

           call foo(x)
                    1
Warning: Character length of actual argument shorter than of dummy argument 'y'
(10/20) at (1)

Paul, can we close this one?


-- 

dfranke at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24886

[Bug fortran/24886] different character length in actual and formal argument not detected

[pault at gcc dot gnu dot org]

------- Comment #11 from pault at gcc dot gnu dot org  2009-04-20 11:57 -------
(In reply to comment #10)

> Paul, can we close this one?
> 

Absolutely! It's done.

Paul


-- 

pault at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24886