Re: [RFA] Remove dependency on load address of environ

[Elena Zannoni <ezannoni@redhat.com>]

Fred Fish writes:
 > > I proofread this patch and it looks correct to me, no problems found.
 > > I have not tested it though.
 > 
 > Peter Schauer found one problem with it, an sbrk not protected by HAVE_SBRK.

Ah, I see, in main().

 > Here is a revised patch.
 > 

Looks reasonable. 

Elena


 > -Fred
 > 
 > Index: ChangeLog
 > ===================================================================
 > RCS file: /cvs/src/src/gdb/ChangeLog,v
 > retrieving revision 1.2546
 > diff -c -p -r1.2546 ChangeLog
 > *** ChangeLog	1 May 2002 03:14:05 -0000	1.2546
 > --- ChangeLog	1 May 2002 13:15:46 -0000
 > ***************
 > *** 56,61 ****
 > --- 56,72 ----
 >   	(ppc_sysv_abi_push_arguments): Handle vector parameters.
 >   	* ppc-tdep.h (ppc_sysv_abi_broken_use_struct_convention): Export.
 >           
 > + 2002-04-26  Fred Fish  <fnf@redhat.com>
 > + 
 > + 	* main.c (display_space_base): Add global variable.
 > + 	(main): Initialize display_space_base by calling sbrk.
 > + 
 > + 	* main.c (captured_main): Add display_space_base decl, remove environ
 > + 	decl and reference, remove lim variable, use display_space_base.
 > + 	* top.c (command_loop): Ditto.
 > + 	* event-top.c (command_handler): Ditto.
 > + 	(command_line_handler_continuation): Ditto.
 > + 
 >   2002-04-24  Pierre Muller  <ics.u-strasbg.fr>
 >   
 >   	* hpread.c (hpread_psymtab_to_symtab_1,
 > Index: top.c
 > ===================================================================
 > RCS file: /cvs/src/src/gdb/top.c,v
 > retrieving revision 1.62
 > diff -c -p -r1.62 top.c
 > *** top.c	23 Apr 2002 03:00:57 -0000	1.62
 > --- top.c	1 May 2002 13:15:48 -0000
 > *************** command_loop (void)
 > *** 759,764 ****
 > --- 759,765 ----
 >   #endif
 >     extern int display_time;
 >     extern int display_space;
 > +   extern char *display_space_base;
 >   
 >     while (instream && !feof (instream))
 >       {
 > *************** command_loop (void)
 > *** 782,791 ****
 >         if (display_space)
 >   	{
 >   #ifdef HAVE_SBRK
 > ! 	  extern char **environ;
 > ! 	  char *lim = (char *) sbrk (0);
 > ! 
 > ! 	  space_at_cmd_start = (long) (lim - (char *) &environ);
 >   #endif
 >   	}
 >   
 > --- 783,789 ----
 >         if (display_space)
 >   	{
 >   #ifdef HAVE_SBRK
 > ! 	  space_at_cmd_start = (char *) sbrk (0) - display_space_base;
 >   #endif
 >   	}
 >   
 > *************** command_loop (void)
 > *** 805,813 ****
 >         if (display_space)
 >   	{
 >   #ifdef HAVE_SBRK
 > ! 	  extern char **environ;
 > ! 	  char *lim = (char *) sbrk (0);
 > ! 	  long space_now = lim - (char *) &environ;
 >   	  long space_diff = space_now - space_at_cmd_start;
 >   
 >   	  printf_unfiltered ("Space used: %ld (%c%ld for this command)\n",
 > --- 803,809 ----
 >         if (display_space)
 >   	{
 >   #ifdef HAVE_SBRK
 > ! 	  long space_now = (char *) sbrk (0) - display_space_base;
 >   	  long space_diff = space_now - space_at_cmd_start;
 >   
 >   	  printf_unfiltered ("Space used: %ld (%c%ld for this command)\n",
 > Index: event-top.c
 > ===================================================================
 > RCS file: /cvs/src/src/gdb/event-top.c,v
 > retrieving revision 1.20
 > diff -c -p -r1.20 event-top.c
 > *** event-top.c	27 Mar 2002 21:20:15 -0000	1.20
 > --- event-top.c	1 May 2002 13:15:51 -0000
 > *************** command_handler (char *command)
 > *** 475,480 ****
 > --- 475,481 ----
 >   #endif
 >     extern int display_time;
 >     extern int display_space;
 > +   extern char *display_space_base;
 >   
 >     quit_flag = 0;
 >     if (instream == stdin && stdin_is_tty)
 > *************** command_handler (char *command)
 > *** 494,503 ****
 >     if (display_space)
 >       {
 >   #ifdef HAVE_SBRK
 > !       extern char **environ;
 > !       char *lim = (char *) sbrk (0);
 > ! 
 > !       space_at_cmd_start = (long) (lim - (char *) &environ);
 >   #endif
 >       }
 >   
 > --- 495,501 ----
 >     if (display_space)
 >       {
 >   #ifdef HAVE_SBRK
 > !       space_at_cmd_start = (char *) sbrk (0) - display_space_base;
 >   #endif
 >       }
 >   
 > *************** command_handler (char *command)
 > *** 538,546 ****
 >         if (display_space)
 >   	{
 >   #ifdef HAVE_SBRK
 > ! 	  extern char **environ;
 > ! 	  char *lim = (char *) sbrk (0);
 > ! 	  long space_now = lim - (char *) &environ;
 >   	  long space_diff = space_now - space_at_cmd_start;
 >   
 >   	  printf_unfiltered ("Space used: %ld (%c%ld for this command)\n",
 > --- 536,542 ----
 >         if (display_space)
 >   	{
 >   #ifdef HAVE_SBRK
 > ! 	  long space_now = (char *) sbrk (0) - display_space_base;
 >   	  long space_diff = space_now - space_at_cmd_start;
 >   
 >   	  printf_unfiltered ("Space used: %ld (%c%ld for this command)\n",
 > *************** command_line_handler_continuation (struc
 > *** 560,565 ****
 > --- 556,562 ----
 >   {
 >     extern int display_time;
 >     extern int display_space;
 > +   extern char *display_space_base;
 >   
 >     long time_at_cmd_start  = arg->data.longint;
 >     long space_at_cmd_start = arg->next->data.longint;
 > *************** command_line_handler_continuation (struc
 > *** 577,585 ****
 >     if (display_space)
 >       {
 >   #ifdef HAVE_SBRK
 > !       extern char **environ;
 > !       char *lim = (char *) sbrk (0);
 > !       long space_now = lim - (char *) &environ;
 >         long space_diff = space_now - space_at_cmd_start;
 >   
 >         printf_unfiltered ("Space used: %ld (%c%ld for this command)\n",
 > --- 574,580 ----
 >     if (display_space)
 >       {
 >   #ifdef HAVE_SBRK
 > !       long space_now = (char *) sbrk (0) - display_space_base;
 >         long space_diff = space_now - space_at_cmd_start;
 >   
 >         printf_unfiltered ("Space used: %ld (%c%ld for this command)\n",
 > Index: main.c
 > ===================================================================
 > RCS file: /cvs/src/src/gdb/main.c,v
 > retrieving revision 1.16
 > diff -c -p -r1.16 main.c
 > *** main.c	17 Jan 2002 22:15:17 -0000	1.16
 > --- main.c	1 May 2002 13:15:52 -0000
 > *************** int display_time;
 > *** 45,50 ****
 > --- 45,54 ----
 >   
 >   int display_space;
 >   
 > + /* Remember the lowest sbrk limit when display_space is nonzero. */
 > + 
 > + char *display_space_base;
 > + 
 >   /* Whether this is the async version or not.  The async version is
 >      invoked on the command line with the -nw --async options.  In this
 >      version, the usual command_loop is substituted by and event loop which
 > *************** extern int gdbtk_test (char *);
 > *** 679,689 ****
 >     if (display_space)
 >       {
 >   #ifdef HAVE_SBRK
 > !       extern char **environ;
 > !       char *lim = (char *) sbrk (0);
 > ! 
 > !       printf_unfiltered ("Startup size: data size %ld\n",
 > ! 			 (long) (lim - (char *) &environ));
 >   #endif
 >       }
 >   
 > --- 683,690 ----
 >     if (display_space)
 >       {
 >   #ifdef HAVE_SBRK
 > !       long space_now = (char *) sbrk (0) - display_space_base;
 > !       printf_unfiltered ("Startup size: data size %ld\n", space_now);
 >   #endif
 >       }
 >   
 > *************** main (int argc, char **argv)
 > *** 731,736 ****
 > --- 732,740 ----
 >     struct captured_main_args args;
 >     args.argc = argc;
 >     args.argv = argv;
 > + #ifdef HAVE_SBRK
 > +   display_space_base = sbrk (0);
 > + #endif
 >     catch_errors (captured_main, &args, "", RETURN_MASK_ALL);
 >     return 0;
 >   }