gdb/unittests/scoped_restore-selftests.c

   1 /* Self tests for scoped_restore for GDB, the GNU debugger.
   2
   3    Copyright (C) 2017-2019 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21 #include "selftest.h"
  22 #include "common/scoped_restore.h"
  23
  24 namespace selftests {
  25 namespace scoped_restore_tests {
  26
  27 struct Base {};
  28 struct Derived : Base {};
  29
  30 static int global;
  31
  32 /* Check that we can return a scoped_restore from a function.  Below
  33    we'll make sure this does the right thing.  */
  34 static scoped_restore_tmpl<int>
  35 make_scoped_restore_global (int value)
  36 {
  37   return make_scoped_restore (&global, value);
  38 }
  39
  40 static void
  41 run_tests ()
  42 {
  43   /* Test that single-argument make_scoped_restore restores the
  44      original value on scope exit.  */
  45   {
  46     int integer = 0;
  47     {
  48       scoped_restore restore = make_scoped_restore (&integer);
  49       SELF_CHECK (integer == 0);
  50       integer = 1;
  51     }
  52     SELF_CHECK (integer == 0);
  53   }
  54
  55   /* Same, with two-argument make_scoped_restore.  */
  56   {
  57     int integer = 0;
  58     {
  59       scoped_restore restore = make_scoped_restore (&integer, 1);
  60       SELF_CHECK (integer == 1);
  61     }
  62     SELF_CHECK (integer == 0);
  63   }
  64
  65   /* Test releasing a scoped_restore.  */
  66   {
  67     int integer = 0;
  68     {
  69       scoped_restore restore = make_scoped_restore (&integer, 1);
  70       SELF_CHECK (integer == 1);
  71       restore.release ();
  72     }
  73     /* The overridden value should persist.  */
  74     SELF_CHECK (integer == 1);
  75   }
  76
  77   /* Test creating a scoped_restore with a value of a type convertible
  78      to T.  */
  79   {
  80     Base *base = nullptr;
  81     Derived derived;
  82     {
  83       scoped_restore restore = make_scoped_restore (&base, &derived);
  84
  85       SELF_CHECK (base == &derived);
  86     }
  87     SELF_CHECK (base == nullptr);
  88   }
  89
  90   /* Test calling a function that returns a scoped restore.  Makes
  91      sure that if the compiler emits a call to the copy ctor, that we
  92      still do the right thing.  */
  93   {
  94     {
  95       SELF_CHECK (global == 0);
  96       scoped_restore restore = make_scoped_restore_global (1);
  97       SELF_CHECK (global == 1);
  98     }
  99     SELF_CHECK (global == 0);
 100   }
 101 }
 102
 103 } /* namespace scoped_restore_tests */
 104 } /* namespace selftests */
 105
 106 void
 107 _initialize_scoped_restore_selftests ()
 108 {
 109   selftests::register_test ("scoped_restore",
 110                             selftests::scoped_restore_tests::run_tests);
 111 }