| 1 | /* Self tests for function_view 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 "gdbsupport/selftest.h" |
| 22 | #include "gdbsupport/function-view.h" |
| 23 | |
| 24 | namespace selftests { |
| 25 | namespace function_view { |
| 26 | |
| 27 | static int |
| 28 | plus_one_fn_int (int val) |
| 29 | { |
| 30 | return ++val; |
| 31 | } |
| 32 | |
| 33 | static short |
| 34 | plus_one_fn_short (short val) |
| 35 | { |
| 36 | return ++val; |
| 37 | } |
| 38 | |
| 39 | static int |
| 40 | call_callback_int (int val, gdb::function_view <int (int)> callback) |
| 41 | { |
| 42 | return callback (val); |
| 43 | } |
| 44 | |
| 45 | static void |
| 46 | call_callback_void (int val, gdb::function_view <void (int)> callback) |
| 47 | { |
| 48 | callback (val); |
| 49 | } |
| 50 | |
| 51 | struct plus_one_int_func_obj |
| 52 | { |
| 53 | int operator () (int val) |
| 54 | { |
| 55 | ++call_count; |
| 56 | return ++val; |
| 57 | } |
| 58 | |
| 59 | /* Number of times called. */ |
| 60 | int call_count = 0; |
| 61 | }; |
| 62 | |
| 63 | static void |
| 64 | run_tests () |
| 65 | { |
| 66 | /* A simple lambda. */ |
| 67 | auto plus_one_lambda = [] (int val) { return ++val; }; |
| 68 | |
| 69 | /* A function_view that references the lambda. */ |
| 70 | gdb::function_view<int (int)> plus_one_func_view (plus_one_lambda); |
| 71 | |
| 72 | /* Check calling the lambda directly. */ |
| 73 | SELF_CHECK (plus_one_lambda (0) == 1); |
| 74 | SELF_CHECK (plus_one_lambda (1) == 2); |
| 75 | |
| 76 | /* Check calling lambda via the view. */ |
| 77 | SELF_CHECK (plus_one_func_view (2) == 3); |
| 78 | SELF_CHECK (plus_one_func_view (3) == 4); |
| 79 | |
| 80 | /* Check calling a function that takes a function_view as argument, |
| 81 | by value. Pass a lambda, making sure a function_view is properly |
| 82 | constructed implicitly. */ |
| 83 | SELF_CHECK (call_callback_int (1, [] (int val) |
| 84 | { |
| 85 | return val + 2; |
| 86 | }) == 3); |
| 87 | |
| 88 | /* Same, passing a named/lvalue lambda. */ |
| 89 | SELF_CHECK (call_callback_int (1, plus_one_lambda) == 2); |
| 90 | /* Same, passing a named/lvalue function_view (should copy). */ |
| 91 | SELF_CHECK (call_callback_int (1, plus_one_func_view) == 2); |
| 92 | |
| 93 | /* Check constructing a function view over a function-object |
| 94 | callable, and calling it. */ |
| 95 | plus_one_int_func_obj func_obj; |
| 96 | SELF_CHECK (func_obj (0) == 1); |
| 97 | SELF_CHECK (call_callback_int (1, func_obj) == 2); |
| 98 | /* Check that the callable was referenced, not copied. */ |
| 99 | SELF_CHECK (func_obj.call_count == 2); |
| 100 | |
| 101 | /* Check constructing a function_view over a free-function callable, |
| 102 | and calling it. */ |
| 103 | SELF_CHECK (call_callback_int (1, plus_one_fn_int) == 2); |
| 104 | |
| 105 | /* Check calling a function with a |
| 106 | compatible-but-not-exactly-the-same prototype. */ |
| 107 | SELF_CHECK (call_callback_int (1, [] (short val) -> short |
| 108 | { |
| 109 | return val + 2; |
| 110 | }) == 3); |
| 111 | /* Same, but passing a function pointer. */ |
| 112 | SELF_CHECK (call_callback_int (1, plus_one_fn_short) == 2); |
| 113 | |
| 114 | /* Like std::function, a function_view that expects a void return |
| 115 | can reference callables with non-void return type. The result is |
| 116 | simply discarded. Check a lambda, function object and a function |
| 117 | pointer. */ |
| 118 | call_callback_void (1, [] (int val) -> int |
| 119 | { |
| 120 | return val + 2; |
| 121 | }); |
| 122 | call_callback_void (1, func_obj); |
| 123 | call_callback_void (1, plus_one_fn_int); |
| 124 | |
| 125 | /* Check that the main ctor doesn't hijack the copy ctor. */ |
| 126 | auto plus_one_func_view2 (plus_one_func_view); |
| 127 | auto plus_one_func_view3 (plus_one_func_view2); |
| 128 | static_assert (std::is_same<decltype (plus_one_func_view), |
| 129 | decltype (plus_one_func_view2)>::value, ""); |
| 130 | static_assert (std::is_same<decltype (plus_one_func_view), |
| 131 | decltype (plus_one_func_view3)>::value, ""); |
| 132 | |
| 133 | SELF_CHECK (plus_one_func_view3 (1) == 2); |
| 134 | |
| 135 | /* Likewise, but propagate a NULL callable. If this calls the main |
| 136 | function_view ctor instead of the copy ctor by mistake, then |
| 137 | null_func_2 ends up non-NULL (because it'd instead reference |
| 138 | null_func_1 as just another callable). */ |
| 139 | constexpr gdb::function_view<int (int)> null_func_view_1 = nullptr; |
| 140 | constexpr auto null_func_view_2 (null_func_view_1); |
| 141 | |
| 142 | /* While at it, check whether the function_view is bound using |
| 143 | various forms, op==, op!= and op bool. */ |
| 144 | |
| 145 | /* op== */ |
| 146 | static_assert (null_func_view_2 == nullptr, ""); |
| 147 | static_assert (nullptr == null_func_view_2, ""); |
| 148 | static_assert (null_func_view_2 == NULL, ""); |
| 149 | static_assert (NULL == null_func_view_2, ""); |
| 150 | |
| 151 | /* op!= */ |
| 152 | static_assert (!(null_func_view_2 != nullptr), ""); |
| 153 | static_assert (!(nullptr != null_func_view_2), ""); |
| 154 | static_assert (!(null_func_view_2 != NULL), ""); |
| 155 | static_assert (!(NULL != null_func_view_2), ""); |
| 156 | |
| 157 | /* op bool */ |
| 158 | static_assert (!null_func_view_2, ""); |
| 159 | |
| 160 | /* Check the nullptr_t ctor. */ |
| 161 | constexpr gdb::function_view<int (int)> check_ctor_nullptr (nullptr); |
| 162 | static_assert (!check_ctor_nullptr, ""); |
| 163 | |
| 164 | /* Check the nullptr_t op= */ |
| 165 | gdb::function_view<int (int)> check_op_eq_null (plus_one_fn_int); |
| 166 | SELF_CHECK (check_op_eq_null); |
| 167 | check_op_eq_null = nullptr; |
| 168 | SELF_CHECK (!check_op_eq_null); |
| 169 | } |
| 170 | |
| 171 | } /* namespace function_view */ |
| 172 | } /* namespace selftests */ |
| 173 | |
| 174 | void |
| 175 | _initialize_function_view_selftests () |
| 176 | { |
| 177 | selftests::register_test ("function_view", |
| 178 | selftests::function_view::run_tests); |
| 179 | } |