gdb/testsuite/gdb.reverse/step-reverse.c

   1 /* This testcase is part of GDB, the GNU debugger.
   2
   3    Copyright 2008-2024 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 #include <string.h>
  20
  21 /* Test various kinds of stepping.
  22 */
  23 int myglob = 0;
  24
  25 int callee() {          /* ENTER CALLEE */
  26   return myglob++;      /* ARRIVED IN CALLEE */
  27 }                       /* RETURN FROM CALLEE */
  28
  29 /* We need to make this function take more than a single instruction
  30    to run, otherwise it could hide PR gdb/16678, as reverse execution can
  31    step over a single-instruction function.  */
  32 int
  33 recursive_callee (int val)
  34 {
  35   if (val == 0)
  36     return 0;
  37   val /= 2;
  38   if (val > 1)
  39     val++;
  40   return recursive_callee (val);        /* RECURSIVE CALL */
  41 } /* EXIT RECURSIVE FUNCTION */
  42
  43 /* A structure which, we hope, will need to be passed using memcpy.  */
  44 struct rhomboidal {
  45   int rather_large[100];
  46 };
  47
  48 void
  49 large_struct_by_value (struct rhomboidal r)
  50 {
  51   myglob += r.rather_large[42]; /* step-test.exp: arrive here 1 */
  52 }
  53
  54 int main () {
  55    int w,x,y,z;
  56    int a[10], b[10];
  57
  58    /* Test "next" and "step" */
  59    w = 0;       /* BREAK AT MAIN */
  60    x = 1;       /* NEXT TEST 1 */
  61    y = 2;       /* STEP TEST 1 */
  62    z = 3;       /* REVERSE NEXT TEST 1 */
  63    w = w + 2;   /* NEXT TEST 2 */
  64    x = x + 3;   /* REVERSE STEP TEST 1 */
  65    y = y + 4;
  66    z = z + 5;   /* STEP TEST 2 */
  67
  68    /* Test that next goes over recursive calls too */
  69    recursive_callee (32); /* NEXT OVER THIS RECURSION */
  70
  71    /* Test that "next" goes over a call */
  72    callee();    /* NEXT OVER THIS CALL */
  73
  74    /* Test that "step" doesn't */
  75    callee();    /* STEP INTO THIS CALL */
  76
  77    /* Test "stepi" */
  78    a[5] = a[3] - a[4]; /* FINISH TEST */
  79    callee();    /* STEPI TEST */
  80
  81    /* Test "nexti" */
  82    callee();    /* NEXTI TEST */
  83
  84    y = w + z;
  85
  86    {
  87      struct rhomboidal r;
  88      memset (r.rather_large, 0, sizeof (r.rather_large));
  89      r.rather_large[42] = 10;
  90      large_struct_by_value (r);  /* step-test.exp: large struct by value */
  91    }
  92
  93    exit (0); /* end of main */
  94 }
  95