[Bug fortran/23308] named common block confused as procedure - runtime segfault

[Bug fortran/23308] named common block confused as procedure - runtime segfault

[pinskia at gcc dot gnu dot org]

------- Comment #2 from pinskia at gcc dot gnu dot org  2006-01-07 05:31 -------
Note I think fixing PR 25710 and the mentioned problem of not keeping symbols
correctly will fix this bug.  I have been trying to fix this but it is hard.

Also note we have the same problem with "call" to functions.

Also I have been thinking ICC is not a good compiler to test with for
diagnostic issues.

Actually this is only horrible Fortran 95 according to Lahey's fortran
compiler.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23308

[Bug fortran/23308] named common block confused as procedure - runtime segfault

[pault at gcc dot gnu dot org]

------- Comment #3 from pault at gcc dot gnu dot org  2006-01-07 17:07 -------
(In reply to comment #2)
> Note I think fixing PR 25710 and the mentioned problem of not keeping symbols
> correctly will fix this bug.  I have been trying to fix this but it is hard.

I notice that there is a handle in gfortran.h to deal with this:

/* Global symbols are symbols of global scope. Currently we only use
   this to detect collisions already when parsing.
   TODO: Extend to verify procedure calls.  */

typedef struct gfc_gsymbol
{
  BBT_HEADER(gfc_gsymbol);

  const char *name;
  enum { GSYM_UNKNOWN=1, GSYM_PROGRAM, GSYM_FUNCTION, GSYM_SUBROUTINE,
        GSYM_MODULE, GSYM_COMMON, GSYM_BLOCK_DATA } type;

  int defined, used;
  locus where;
}
gfc_gsymbol;

extern gfc_gsymbol *gfc_gsym_root;

and in symbol.c

/* Search a tree for the global symbol.  */

gfc_gsymbol *
gfc_find_gsymbol (gfc_gsymbol *symbol, const char *name)
{

++++friends

Astonishingly, none of this is ever used!

The experimental patch below picks up pr25710 but not this one.  COMMON blocks
need to be given a gsymbol, methinks.

Paul

Index: gcc/fortran/resolve.c
===================================================================
*** gcc/fortran/resolve.c       (revision 109449)
--- gcc/fortran/resolve.c       (working copy)
*************** resolve_function (gfc_expr * expr)
*** 1157,1162 ****
--- 1157,1172 ----
    try t;
    int temp;

+   gfc_gsymbol * gsym;
+ 
+   gsym = gfc_find_gsymbol (gfc_gsym_root, expr->symtree->n.sym->name);
+ 
+   if ((gsym && gsym->type != GSYM_UNKNOWN && gsym->type != GSYM_FUNCTION)
+        ||
+       (expr->symtree && !expr->symtree->n.sym->attr.external &&
!expr->symtree->n.sym->attr.subroutine))
+     gfc_warning_now ("CALL at %L to procedure %s which is not a function",
+                    &expr->where, expr->symtree->n.sym->name);
+ 
    /* Switch off assumed size checking and do this again for certain kinds
       of procedure, once the procedure itself is resolved.  */
    need_full_assumed_size++;
*************** resolve_call (gfc_code * c)
*** 1510,1515 ****
--- 1520,1535 ----
  {
    try t;

+   gfc_gsymbol * gsym;
+ 
+   gsym = gfc_find_gsymbol (gfc_gsym_root, c->symtree->n.sym->name);
+ 
+   if ((gsym && gsym->type != GSYM_UNKNOWN && gsym->type != GSYM_SUBROUTINE)
+        ||
+       (c->symtree && !c->symtree->n.sym->attr.external &&
!c->symtree->n.sym->attr.subroutine))
+     gfc_warning_now ("CALL at %L to procedure %s which is not a subroutine",
+                    &c->loc, c->symtree->n.sym->name);
+ 
    /* Switch off assumed size checking and do this again for certain kinds
       of procedure, once the procedure itself is resolved.  */
    need_full_assumed_size++;


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23308

[Bug fortran/23308] named common block confused as procedure - runtime segfault

[pinskia at gcc dot gnu dot org]

------- Comment #4 from pinskia at gcc dot gnu dot org  2006-01-07 19:27 -------
(In reply to comment #3)
> Index: gcc/fortran/resolve.c
> ===================================================================
> *** gcc/fortran/resolve.c       (revision 109449)
> --- gcc/fortran/resolve.c       (working copy)
> *************** resolve_function (gfc_expr * expr)
> *** 1157,1162 ****
> --- 1157,1172 ----
>     try t;
>     int temp;

The only question I have with this patch is the following still passes (this is
the main reason why I filed PR 25710 because I could not get the testcase in
there and this testcase working):
function f()
REAL :: f
f = 1.0
end function
call f
contains
SUBROUTINE f
end SUBROUTINE
end


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23308

[Bug fortran/23308] named common block confused as procedure - runtime segfault

[kargl at gcc dot gnu dot org]

------- Comment #5 from kargl at gcc dot gnu dot org  2006-01-07 20:19 -------
Andrew, Lahey's code checking utility gives

Compiling program unit f at line 1:
Compiling program unit test at line 5:
Encountered 0 errors, 0 warnings, 0 informations in file SOURCE.F90.
Compiling file SOURCE.F90.

NAG's compiler also compiles the code without an error or warning.


-- 

kargl at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23308

[Bug fortran/23308] named common block confused as procedure - runtime segfault

[paulthomas2 at wanadoo dot fr]

------- Comment #6 from paulthomas2 at wanadoo dot fr  2006-01-07 21:44 -------
Subject: Re:  named common block confused as procedure
 - runtime segfault

Steve and Andrew,

>------- Comment #5 from kargl at gcc dot gnu dot org  2006-01-07 20:19 -------
>Andrew, Lahey's code checking utility gives
>
>Compiling program unit f at line 1:
>Compiling program unit test at line 5:
>Encountered 0 errors, 0 warnings, 0 informations in file SOURCE.F90.
>Compiling file SOURCE.F90.
>
>NAG's compiler also compiles the code without an error or warning.
>
>
>  
>
The enclosed patch catches Andrew's PR but also snags on 
g77/19990905-1.f (The Burley test case).  I will sit down with the 
standard and sort out what is and is not required of global symbols, 
contained symbols and scopes in general.  If nothing else, the enclosed 
will catch some nasties that are escaping at the moment.

Best regards

Paul
Index: gcc/fortran/resolve.c
===================================================================
*** gcc/fortran/resolve.c       (revision 109449)
--- gcc/fortran/resolve.c       (working copy)
*************** resolve_function (gfc_expr * expr)
*** 1157,1162 ****
--- 1157,1172 ----
    try t;
    int temp;

+   gfc_gsymbol * gsym;
+ 
+   gsym = NULL;
+   if (expr->symtree && expr->symtree->n.sym)
+     gsym = gfc_find_gsymbol (gfc_gsym_root, expr->symtree->n.sym->name);
+ 
+   if ((gsym && gsym->type != GSYM_UNKNOWN && gsym->type != GSYM_FUNCTION))
+     gfc_warning_now ("reference at %L to %s which is not a function",
+                    &expr->where, expr->symtree->n.sym->name);
+ 
    /* Switch off assumed size checking and do this again for certain kinds
       of procedure, once the procedure itself is resolved.  */
    need_full_assumed_size++;
*************** resolve_call (gfc_code * c)
*** 1510,1515 ****
--- 1520,1535 ----
  {
    try t;

+   gfc_gsymbol * gsym;
+ 
+   gsym = NULL;
+   if (c->symtree && c->symtree->n.sym)
+     gsym = gfc_find_gsymbol (gfc_gsym_root, c->symtree->n.sym->name);
+ 
+   if ((gsym && gsym->type != GSYM_UNKNOWN && gsym->type != GSYM_SUBROUTINE))
+     gfc_warning_now ("CALL at %L to %s which is not a subroutine",
+                    &c->loc, c->symtree->n.sym->name);
+ 
    /* Switch off assumed size checking and do this again for certain kinds
       of procedure, once the procedure itself is resolved.  */
    need_full_assumed_size++;
Index: gcc/fortran/match.c
===================================================================
*** gcc/fortran/match.c (revision 109448)
--- gcc/fortran/match.c (working copy)
*************** gfc_match_common (void)
*** 2247,2252 ****
--- 2247,2253 ----
    gfc_array_spec *as;
    gfc_equiv * e1, * e2;
    match m;
+   gfc_gsymbol *gsym;

    old_blank_common = gfc_current_ns->blank_common.head;
    if (old_blank_common)
*************** gfc_match_common (void)
*** 2263,2268 ****
--- 2264,2278 ----
        if (m == MATCH_ERROR)
        goto cleanup;

+       gsym = gfc_get_gsymbol (name);
+       if (gsym->type != GSYM_UNKNOWN && gsym->type != GSYM_COMMON)
+       {
+         gfc_error ("Symbol '%s' at %C is already an external symbol that is
not COMMON",
+                    sym->name);
+         goto cleanup;
+       }
+       gsym->type = GSYM_COMMON;
+ 
        if (name[0] == '\0')
        {
          t = &gfc_current_ns->blank_common;


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23308

[Bug fortran/23308] named common block confused as procedure - runtime segfault

[paulthomas2 at wanadoo dot fr]

------- Comment #7 from paulthomas2 at wanadoo dot fr  2006-01-07 21:46 -------
Subject: Re:  named common block confused as procedure
 - runtime segfault

> The enclosed patch catches Andrew's PR but also snags on 
> g77/19990905-1.f (The Burley test case).  

In fact, it regtests OK, apart from the above.

Paul


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23308

[Bug fortran/23308] named common block confused as procedure - runtime segfault

[pinskia at gcc dot gnu dot org]

------- Comment #8 from pinskia at gcc dot gnu dot org  2006-01-08 06:13 -------
(In reply to comment #7)
> In fact, it regtests OK, apart from the above.

I want to say that PR 20881 is the same issue too.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
OtherBugsDependingO|                            |20881
              nThis|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23308

[Bug fortran/23308] named common block confused as procedure - runtime segfault

[paulthomas2 at wanadoo dot fr]

------- Comment #9 from paulthomas2 at wanadoo dot fr  2006-01-08 09:49 -------
Subject: Re:  named common block confused as procedure
 - runtime segfault

pinskia at gcc dot gnu dot org wrote:

>------- Comment #8 from pinskia at gcc dot gnu dot org  2006-01-08 06:13 -------
>(In reply to comment #7)
>  
>
>>In fact, it regtests OK, apart from the above.
>>    
>>
>
>I want to say that PR 20881 is the same issue too.
>
>
>  
>
Thanks Andrew,

I know that one of Joost's PRs were associated with this issue.

I will sit down tonight with the standard and will work out who can or 
cannot reference whom; I came across entry_1.f90 i the testsuite that 
has a program name thet is the same as one of the procedures.  I believe 
that it is kosher but I want to be really sure.  Equally PR23308 and 
g77/19990905-1.f  need to have their legality sorted out.   Apart from 
that, the patch is ready.   Maybe I should do argument type checking too?

Paul


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23308

[Bug fortran/23308] named common block confused as procedure - runtime segfault

[pinskia at gcc dot gnu dot org]

------- Comment #10 from pinskia at gcc dot gnu dot org  2006-01-08 15:15 -------
(In reply to comment #5)
> Andrew, Lahey's code checking utility gives

Lahey's Fortran 95 code checker that is online gives:
  2604-S: "SOURCE.F90", line 3: The name 'foo' cannot be specified as both
external procedure name and common block name. The previous appearance is in
'line 4'.
  2521-S: "SOURCE.F90", line 4: Intrinsic procedure name or external procedure
name same as common block name 'foo'.


So maybe this should only be an error in Fortran 95 mode.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23308

[Bug fortran/23308] named common block confused as procedure - runtime segfault

[pault at gcc dot gnu dot org]

------- Comment #11 from pault at gcc dot gnu dot org  2006-01-21 09:09 -------
Subject: Bug 23308

Author: pault
Date: Sat Jan 21 09:08:54 2006
New Revision: 110063

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=110063
Log:
2005-01-21  Paul Thomas  <pault@gcc.gnu.org>

        PR fortran/25124
        PR fortran/25625
        * decl.c (get_proc_name): If there is an existing
        symbol in the encompassing namespace, call errors
        if it is a procedure of the same name or the kind
        field is set, indicating a type declaration.

        PR fortran/20881
        PR fortran/23308
        PR fortran/25538
        PR fortran/25710
        * decl.c (add_global_entry): New function to check
        for existing global symbol with this name and to
        create new one if none exists.
        (gfc_match_entry): Call add_global_entry before
        matching argument lists for subroutine and function
        entries.
        * gfortran.h: Prototype for existing function,
        global_used.
        * resolve.c (resolve_global_procedure): New function
        to check global symbols for procedures.
        (resolve_call, resolve_function): Calls to this
        new function for non-contained and non-module
        procedures.
        * match.c (match_common): Add check for existing
        global symbol, creat one if none exists and emit
        error if there is a clash.
        * parse.c (global_used): Remove static and use the
        gsymbol name rather than the new_block name, so that
        the function can be called from resolve.c.
        (parse_block_data, parse_module, add_global_procedure):
        Improve checks for existing gsymbols.  Emit error if
        already defined or if references were to another type.
        Set defined flag.

        PR fortran/PR24276
        * trans-expr.c (gfc_conv_aliased_arg): New function called by 
        gfc_conv_function_call that coverts an expression for an aliased
        component reference to a derived type array into a temporary array
        of the same type as the component.  The temporary is passed as an
        actual argument for the procedure call and is copied back to the
        derived type after the call.
        (is_aliased_array): New function that detects an array reference
        that is followed by a component reference.
        (gfc_conv_function_call): Detect an aliased actual argument with
        is_aliased_array and convert it to a temporary and back again
        using gfc_conv_aliased_arg.

2005-01-21  Paul Thomas  <pault@gcc.gnu.org>

        PR fortran/25124
        PR fortran/25625
        * gfortran.dg/internal_references_1.f90: New test.
          PR fortran/20881
        PR fortran/23308
        PR fortran/25538
        PR fortran/25710
        * gfortran.dg/global_references_1.f90: New test.
        * gfortran.dg/g77/19990905-1.f: Restore the error that
        there is a clash between the common block name and
        the name of a subroutine reference.

        PR fortran/PR24276
        * gfortran.dg/aliasing_dummy_1.f90: New test.

Added:
    trunk/gcc/testsuite/gfortran.dg/aliasing_dummy_1.f90
    trunk/gcc/testsuite/gfortran.dg/global_references_1.f90
    trunk/gcc/testsuite/gfortran.dg/internal_references_1.f90
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/decl.c
    trunk/gcc/fortran/gfortran.h
    trunk/gcc/fortran/match.c
    trunk/gcc/fortran/parse.c
    trunk/gcc/fortran/resolve.c
    trunk/gcc/fortran/trans-expr.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gfortran.dg/g77/19990905-1.f


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23308

[Bug fortran/23308] named common block confused as procedure - runtime segfault

[pault at gcc dot gnu dot org]

------- Comment #12 from pault at gcc dot gnu dot org  2006-01-27 22:16 -------
Subject: Bug 23308

Author: pault
Date: Fri Jan 27 22:16:04 2006
New Revision: 110310

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=110310
Log:
2005-01-28  Paul Thomas  <pault@gcc.gnu.org>

        PR fortran/25964
        * resolve.c (resolve_function): Exclude statement functions from
        global reference checking.

        PR fortran/25084
        PR fortran/20852
        PR fortran/25085
        PR fortran/25086
        * resolve.c (resolve_function): Declare a gfc_symbol to replace the
        references through the symtree to the symbol associated with the
        function expresion. Give error on reference to an assumed character
        length function is defined in an interface or an external function
        that is not a dummy argument.
        (resolve_symbol): Give error if an assumed character length function
        is array-valued, pointer-valued, pure or recursive. Emit warning
        that character(*) value functions are obsolescent in F95.

        PR fortran/25416
        * trans-expr.c (gfc_conv_function_call): The above patch to resolve.c
        prevents any assumed character length function call from getting here
        except intrinsics such as SPREAD. In this case, ensure that no
        segfault occurs from referencing non-existent charlen->length->
        expr_type and provide a backend_decl for the charlen from the charlen
        of the first actual argument.

        Cure temp name confusion.
        * trans-expr.c (gfc_get_interface_mapping_array): Change name of
        temporary from "parm" to "ifm" to avoid clash with temp coming from
        trans-array.c.

        PR fortran/25124
        PR fortran/25625
        * decl.c (get_proc_name): If there is an existing
        symbol in the encompassing namespace, call errors
        if it is a procedure of the same name or the kind
        field is set, indicating a type declaration.

        PR fortran/20881
        PR fortran/23308
        PR fortran/25538
        PR fortran/25710
        * decl.c (add_global_entry): New function to check
        for existing global symbol with this name and to
        create new one if none exists.
        (gfc_match_entry): Call add_global_entry before
        matching argument lists for subroutine and function
        entries.
        * gfortran.h: Prototype for existing function, global_used.
        * resolve.c (resolve_global_procedure): New function
        to check global symbols for procedures.
        (resolve_call, resolve_function): Calls to this
        new function for non-contained and non-module
        procedures.
        * match.c (match_common): Add check for existing
        global symbol, creat one if none exists and emit
        error if there is a clash.
        * parse.c (global_used): Remove static and use the
        gsymbol name rather than the new_block name, so that
        the function can be called from resolve.c.
        (parse_block_data, parse_module, add_global_procedure):
        Improve checks for existing gsymbols.  Emit error if
        already defined or if references were to another type.
        Set defined flag.

        PR fortran/24276
        * trans-expr.c (gfc_conv_aliased_arg): New function called by 
        gfc_conv_function_call that coverts an expression for an aliased
        component reference to a derived type array into a temporary array
        of the same type as the component.  The temporary is passed as an
        actual argument for the procedure call and is copied back to the
        derived type after the call.
        (is_aliased_array): New function that detects an array reference
        that is followed by a component reference.
        (gfc_conv_function_call): Detect an aliased actual argument with
        is_aliased_array and convert it to a temporary and back again
        using gfc_conv_aliased_arg.

        PR fortran/25124
        PR fortran/25625
        * gfortran.dg/internal_references_1.f90: New test.

        PR fortran/25901
        * gfortran.dg/internal references_2.f90: New test.

        PR fortran/20881
        PR fortran/23308
        PR fortran/25538
        PR fortran/25710
        * gfortran.dg/global_references_1.f90: New test.
        * gfortran.dg/g77/19990905-1.f: Restore the error that
        there is a clash between the common block name and
        the name of a subroutine reference.

        PR fortran/25964
        * gfortran.dg/global_references_2.f90: New test.

        PR fortran/24276
        * gfortran.dg/aliasing_dummy_1.f90: New test.

        PR fortran/25084
        PR fortran/20852
        PR fortran/25085
        PR fortran/25086
        * gfortran.dg/assumed_charlen_function_1.f90: New test.
        * gfortran.dg/assumed_charlen_function_3.f90: New test.

        PR fortran/25416
        * gfortran.dg/assumed_charlen_function_2.f90: New test.

        PR fortran/25964
        * gfortran.dg/assumed_size_refs_3.f90: New test.

Added:
    branches/gcc-4_1-branch/gcc/testsuite/gfortran.dg/aliasing_dummy_1.f90
   
branches/gcc-4_1-branch/gcc/testsuite/gfortran.dg/assumed_charlen_function_1.f90
   
branches/gcc-4_1-branch/gcc/testsuite/gfortran.dg/assumed_charlen_function_2.f90
   
branches/gcc-4_1-branch/gcc/testsuite/gfortran.dg/assumed_charlen_function_3.f90
    branches/gcc-4_1-branch/gcc/testsuite/gfortran.dg/assumed_size_refs_3.f90
    branches/gcc-4_1-branch/gcc/testsuite/gfortran.dg/global_references_1.f90
    branches/gcc-4_1-branch/gcc/testsuite/gfortran.dg/global_references_2.f90
    branches/gcc-4_1-branch/gcc/testsuite/gfortran.dg/internal_references_1.f90
    branches/gcc-4_1-branch/gcc/testsuite/gfortran.dg/internal_references_2.f90
Modified:
    branches/gcc-4_1-branch/gcc/fortran/ChangeLog
    branches/gcc-4_1-branch/gcc/fortran/decl.c
    branches/gcc-4_1-branch/gcc/fortran/gfortran.h
    branches/gcc-4_1-branch/gcc/fortran/match.c
    branches/gcc-4_1-branch/gcc/fortran/parse.c
    branches/gcc-4_1-branch/gcc/fortran/resolve.c
    branches/gcc-4_1-branch/gcc/fortran/symbol.c
    branches/gcc-4_1-branch/gcc/fortran/trans-expr.c
    branches/gcc-4_1-branch/gcc/testsuite/ChangeLog
    branches/gcc-4_1-branch/gcc/testsuite/gfortran.dg/g77/19990905-1.f


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23308

[Bug fortran/23308] named common block confused as procedure - runtime segfault

[pault at gcc dot gnu dot org]

------- Comment #13 from pault at gcc dot gnu dot org  2006-01-27 22:30 -------
Fixed on trunk and 4.1

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=23308

[Bug fortran/23308] named common block confused as procedure - runtime segfault

[pinskia at gcc dot gnu dot org]

-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.1.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23308

[Bug fortran/23308] named common block confused as procedure - runtime segfault

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-08-10 11:50 -------
Confirmed, ICC also does not warn or error out.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2005-08-10 11:50:15
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23308