gdb/testsuite/gdb.base/nested-subp3.c

   1 /* This test program is part of GDB, the GNU debugger.
   2
   3    Copyright 2015-2019 Free Software Foundation, Inc.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  17
  18 #include <stdlib.h>
  19
  20 typedef void (*callback_t) (void);
  21
  22 extern void process (callback_t cb);
  23 extern void parent (int first, callback_t cb);
  24
  25 void
  26 ignore (int unused)
  27 {
  28   (void) unused;
  29 }
  30
  31 void
  32 process (callback_t cb)
  33 {
  34   parent (0, cb);
  35 }
  36
  37 void
  38 parent (int first, callback_t cb)
  39 {
  40   void child (void)
  41   {
  42     /* When reaching this, there are two block instances for PARENT on the
  43        stack: the one that is right in the upper frame is not the one actually
  44        used for non-local references, so GDB has to follow the static link in
  45        order to get the correct instance, and thus in order to read the proper
  46        variables.
  47
  48        As a simple check, we can verify that under GDB, the following is true:
  49        parent_first == first (which should be one: see the IF block below).  */
  50     const int parent_first = first;
  51     ignore (parent_first); /* STOP */
  52     ignore (first);
  53   }
  54
  55   if (first)
  56     process (&child);
  57   else
  58     cb ();
  59 }
  60
  61 int
  62 main ()
  63 {
  64   parent (1, NULL);
  65   return 0;
  66 }