gdb/testsuite/gdb.cp/call-method-register.cc

   1 /* This testcase is part of GDB, the GNU debugger.
   2
   3    Copyright 1993-2021 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 #if defined __x86_64__
  19 # define ASM_REG "rax"
  20 #elif defined __i386__
  21 # define ASM_REG "eax"
  22 #else
  23 # error "port me"
  24 #endif
  25
  26 /* A class small enough that it fits in a register.  */
  27 struct small
  28 {
  29   int x;
  30   int method ();
  31 };
  32
  33 int
  34 small::method ()
  35 {
  36   return x + 5;
  37 }
  38
  39 int
  40 register_class ()
  41 {
  42   /* Given the use of the GNU register-asm local variables extension,
  43      the compiler puts this variable in a register.  This means that
  44      GDB can't call any methods for this variable, which is what we
  45      want to test.  */
  46   register small v asm (ASM_REG);
  47
  48   int i;
  49
  50   /* Perform a computation sufficiently complicated that optimizing
  51      compilers won't optimize out the variable.  If some compiler
  52      constant-folds this whole loop, maybe using a parameter to this
  53      function here would help.  */
  54   v.x = 0;
  55   for (i = 0; i < 13; ++i)
  56     v.x += i;
  57   --v.x; /* v.x is now 77 */
  58   return v.x + 5; /* set breakpoint here */
  59 }
  60
  61 int
  62 main ()
  63 {
  64   register_class ();
  65   return 0;
  66 }