[RFC]: set the main function in Fortran programs to "MAIN__"

[Wu Zhou <woodzltc at cn dot ibm dot com>]

Daniel,

Although the proper way of adding case insensitivity to symbol lookup is 
still under discussion, I think it might be desirable to set the main 
function of Fortran programs to "MAIN__" first.  Because it can at least 
let GDB recognize that the language is Fortran after loading a Fortran 
executable only.  What is your idea on this?  Please comments.  TIA!

Here is the patch to set the main function in Fortran programs to 
"MAIN__".  And followed is a patch to verify this.  Tested with g77 and 
gfortran on x86, and g77 on ppc64.  With the first patch, it reported 
PASS; without, report FAIL.  No regression is found in gdb.fortran 
testcases.  

P.S: if there is a symbol named "MAIN__" in sources of other languages, it 
might disturb the debugging.  But I am not sure how much it is.

Index: gdb/symtab.c
===================================================================
RCS file: /cvs/src/src/gdb/symtab.c,v
retrieving revision 1.145
diff -c -p -r1.145 symtab.c
*** gdb/symtab.c	8 Mar 2005 04:34:44 -0000	1.145
--- gdb/symtab.c	28 Jul 2005 03:16:48 -0000
*************** find_main_name (void)
*** 4125,4132 ****
      }
  
    /* The languages above didn't identify the name of the main procedure.
!      Fallback to "main".  */
!   set_main_name ("main");
  }
  
  char *
--- 4125,4136 ----
      }
  
    /* The languages above didn't identify the name of the main procedure.
!      Fallback to "MAIN__" (g77 and gfortran) if we can find it in the 
!      minimal symtab, to "main" otherwise.  */
!   if (lookup_minimal_symbol ("MAIN__", NULL, NULL))
!     set_main_name ("MAIN__");
!   else
!     set_main_name ("main");
  }
  
  char *

Testcase lang.exp to verify the above patch:
===========================================================
*** /dev/null	Mon Jul 25 13:51:17 2005
--- gdb/testsuite/gdb.fortran/lang.exp	Mon Jul 25 06:50:20 2005
***************
*** 0 ****
--- 1,40 ----
+ # Copyright 2005 Free Software Foundation, Inc.
+ 
+ # This program is free software; you can redistribute it and/or modify
+ # it under the terms of the GNU General Public License as published by
+ # the Free Software Foundation; either version 2 of the License, or
+ # (at your option) any later version.
+ # 
+ # This program is distributed in the hope that it will be useful,
+ # but WITHOUT ANY WARRANTY; without even the implied warranty of
+ # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ # GNU General Public License for more details.
+ # 
+ # You should have received a copy of the GNU General Public License
+ # along with this program; if not, write to the Free Software
+ # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  
+ 
+ # This file was written by Wu Zhou. (woodzltc@cn.ibm.com)
+ 
+ # This file is part of the gdb testsuite.  It is intended to test that gdb
+ # could recognize the Fortran language after loading the binary
+ 
+ if $tracelevel then {
+ 	strace $tracelevel
+ }
+ 
+ set testfile "array-element"
+ set srcfile ${srcdir}/${subdir}/${testfile}.f
+ set binfile ${objdir}/${subdir}/${testfile}
+ 
+ if  { [gdb_compile "${srcfile}" "${binfile}" executable {debug f77}] != "" } {
+     untested "Couldn't compile ${srcfile}"
+     return -1
+ }
+ 
+ gdb_exit
+ gdb_start
+ gdb_reinitialize_dir $srcdir/$subdir
+ gdb_load ${binfile}
+ 
+ gdb_test "show language" ".*currently fortran.*" "show language(fortran)"


Regards
- Wu Zhou