xref: /freebsd/contrib/googletest/googlemock/include/gmock/internal/gmock-pp.h (revision 28f6c2f292806bf31230a959bc4b19d7081669a7)
1 #ifndef GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_GMOCK_PP_H_
2 #define GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_GMOCK_PP_H_
3 
4 // Expands and concatenates the arguments. Constructed macros reevaluate.
5 #define GMOCK_PP_CAT(_1, _2) GMOCK_PP_INTERNAL_CAT(_1, _2)
6 
7 // Expands and stringifies the only argument.
8 #define GMOCK_PP_STRINGIZE(...) GMOCK_PP_INTERNAL_STRINGIZE(__VA_ARGS__)
9 
10 // Returns empty. Given a variadic number of arguments.
11 #define GMOCK_PP_EMPTY(...)
12 
13 // Returns a comma. Given a variadic number of arguments.
14 #define GMOCK_PP_COMMA(...) ,
15 
16 // Returns the only argument.
17 #define GMOCK_PP_IDENTITY(_1) _1
18 
19 // Evaluates to the number of arguments after expansion.
20 //
21 //   #define PAIR x, y
22 //
23 //   GMOCK_PP_NARG() => 1
24 //   GMOCK_PP_NARG(x) => 1
25 //   GMOCK_PP_NARG(x, y) => 2
26 //   GMOCK_PP_NARG(PAIR) => 2
27 //
28 // Requires: the number of arguments after expansion is at most 15.
29 #define GMOCK_PP_NARG(...) \
30   GMOCK_PP_INTERNAL_16TH(  \
31       (__VA_ARGS__, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0))
32 
33 // Returns 1 if the expansion of arguments has an unprotected comma. Otherwise
34 // returns 0. Requires no more than 15 unprotected commas.
35 #define GMOCK_PP_HAS_COMMA(...) \
36   GMOCK_PP_INTERNAL_16TH(       \
37       (__VA_ARGS__, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0))
38 
39 // Returns the first argument.
40 #define GMOCK_PP_HEAD(...) GMOCK_PP_INTERNAL_HEAD((__VA_ARGS__, unusedArg))
41 
42 // Returns the tail. A variadic list of all arguments minus the first. Requires
43 // at least one argument.
44 #define GMOCK_PP_TAIL(...) GMOCK_PP_INTERNAL_TAIL((__VA_ARGS__))
45 
46 // Calls CAT(_Macro, NARG(__VA_ARGS__))(__VA_ARGS__)
47 #define GMOCK_PP_VARIADIC_CALL(_Macro, ...) \
48   GMOCK_PP_IDENTITY(                        \
49       GMOCK_PP_CAT(_Macro, GMOCK_PP_NARG(__VA_ARGS__))(__VA_ARGS__))
50 
51 // If the arguments after expansion have no tokens, evaluates to `1`. Otherwise
52 // evaluates to `0`.
53 //
54 // Requires: * the number of arguments after expansion is at most 15.
55 //           * If the argument is a macro, it must be able to be called with one
56 //             argument.
57 //
58 // Implementation details:
59 //
60 // There is one case when it generates a compile error: if the argument is macro
61 // that cannot be called with one argument.
62 //
63 //   #define M(a, b)  // it doesn't matter what it expands to
64 //
65 //   // Expected: expands to `0`.
66 //   // Actual: compile error.
67 //   GMOCK_PP_IS_EMPTY(M)
68 //
69 // There are 4 cases tested:
70 //
71 // * __VA_ARGS__ possible expansion has no unparen'd commas. Expected 0.
72 // * __VA_ARGS__ possible expansion is not enclosed in parenthesis. Expected 0.
73 // * __VA_ARGS__ possible expansion is not a macro that ()-evaluates to a comma.
74 //   Expected 0
75 // * __VA_ARGS__ is empty, or has unparen'd commas, or is enclosed in
76 //   parenthesis, or is a macro that ()-evaluates to comma. Expected 1.
77 //
78 // We trigger detection on '0001', i.e. on empty.
79 #define GMOCK_PP_IS_EMPTY(...)                                               \
80   GMOCK_PP_INTERNAL_IS_EMPTY(GMOCK_PP_HAS_COMMA(__VA_ARGS__),                \
81                              GMOCK_PP_HAS_COMMA(GMOCK_PP_COMMA __VA_ARGS__), \
82                              GMOCK_PP_HAS_COMMA(__VA_ARGS__()),              \
83                              GMOCK_PP_HAS_COMMA(GMOCK_PP_COMMA __VA_ARGS__()))
84 
85 // Evaluates to _Then if _Cond is 1 and _Else if _Cond is 0.
86 #define GMOCK_PP_IF(_Cond, _Then, _Else) \
87   GMOCK_PP_CAT(GMOCK_PP_INTERNAL_IF_, _Cond)(_Then, _Else)
88 
89 // Similar to GMOCK_PP_IF but takes _Then and _Else in parentheses.
90 //
91 // GMOCK_PP_GENERIC_IF(1, (a, b, c), (d, e, f)) => a, b, c
92 // GMOCK_PP_GENERIC_IF(0, (a, b, c), (d, e, f)) => d, e, f
93 //
94 #define GMOCK_PP_GENERIC_IF(_Cond, _Then, _Else) \
95   GMOCK_PP_REMOVE_PARENS(GMOCK_PP_IF(_Cond, _Then, _Else))
96 
97 // Evaluates to the number of arguments after expansion. Identifies 'empty' as
98 // 0.
99 //
100 //   #define PAIR x, y
101 //
102 //   GMOCK_PP_NARG0() => 0
103 //   GMOCK_PP_NARG0(x) => 1
104 //   GMOCK_PP_NARG0(x, y) => 2
105 //   GMOCK_PP_NARG0(PAIR) => 2
106 //
107 // Requires: * the number of arguments after expansion is at most 15.
108 //           * If the argument is a macro, it must be able to be called with one
109 //             argument.
110 #define GMOCK_PP_NARG0(...) \
111   GMOCK_PP_IF(GMOCK_PP_IS_EMPTY(__VA_ARGS__), 0, GMOCK_PP_NARG(__VA_ARGS__))
112 
113 // Expands to 1 if the first argument starts with something in parentheses,
114 // otherwise to 0.
115 #define GMOCK_PP_IS_BEGIN_PARENS(...)                              \
116   GMOCK_PP_HEAD(GMOCK_PP_CAT(GMOCK_PP_INTERNAL_IBP_IS_VARIADIC_R_, \
117                              GMOCK_PP_INTERNAL_IBP_IS_VARIADIC_C __VA_ARGS__))
118 
119 // Expands to 1 is there is only one argument and it is enclosed in parentheses.
120 #define GMOCK_PP_IS_ENCLOSED_PARENS(...)             \
121   GMOCK_PP_IF(GMOCK_PP_IS_BEGIN_PARENS(__VA_ARGS__), \
122               GMOCK_PP_IS_EMPTY(GMOCK_PP_EMPTY __VA_ARGS__), 0)
123 
124 // Remove the parens, requires GMOCK_PP_IS_ENCLOSED_PARENS(args) => 1.
125 #define GMOCK_PP_REMOVE_PARENS(...) GMOCK_PP_INTERNAL_REMOVE_PARENS __VA_ARGS__
126 
127 // Expands to _Macro(0, _Data, e1) _Macro(1, _Data, e2) ... _Macro(K -1, _Data,
128 // eK) as many of GMOCK_INTERNAL_NARG0 _Tuple.
129 // Requires: * |_Macro| can be called with 3 arguments.
130 //           * |_Tuple| expansion has no more than 15 elements.
131 #define GMOCK_PP_FOR_EACH(_Macro, _Data, _Tuple)                        \
132   GMOCK_PP_CAT(GMOCK_PP_INTERNAL_FOR_EACH_IMPL_, GMOCK_PP_NARG0 _Tuple) \
133   (0, _Macro, _Data, _Tuple)
134 
135 // Expands to _Macro(0, _Data, ) _Macro(1, _Data, ) ... _Macro(K - 1, _Data, )
136 // Empty if _K = 0.
137 // Requires: * |_Macro| can be called with 3 arguments.
138 //           * |_K| literal between 0 and 15
139 #define GMOCK_PP_REPEAT(_Macro, _Data, _N)           \
140   GMOCK_PP_CAT(GMOCK_PP_INTERNAL_FOR_EACH_IMPL_, _N) \
141   (0, _Macro, _Data, GMOCK_PP_INTENRAL_EMPTY_TUPLE)
142 
143 // Increments the argument, requires the argument to be between 0 and 15.
144 #define GMOCK_PP_INC(_i) GMOCK_PP_CAT(GMOCK_PP_INTERNAL_INC_, _i)
145 
146 // Returns comma if _i != 0. Requires _i to be between 0 and 15.
147 #define GMOCK_PP_COMMA_IF(_i) GMOCK_PP_CAT(GMOCK_PP_INTERNAL_COMMA_IF_, _i)
148 
149 // Internal details follow. Do not use any of these symbols outside of this
150 // file or we will break your code.
151 #define GMOCK_PP_INTENRAL_EMPTY_TUPLE (, , , , , , , , , , , , , , , )
152 #define GMOCK_PP_INTERNAL_CAT(_1, _2) _1##_2
153 #define GMOCK_PP_INTERNAL_STRINGIZE(...) #__VA_ARGS__
154 #define GMOCK_PP_INTERNAL_CAT_5(_1, _2, _3, _4, _5) _1##_2##_3##_4##_5
155 #define GMOCK_PP_INTERNAL_IS_EMPTY(_1, _2, _3, _4)                             \
156   GMOCK_PP_HAS_COMMA(GMOCK_PP_INTERNAL_CAT_5(GMOCK_PP_INTERNAL_IS_EMPTY_CASE_, \
157                                              _1, _2, _3, _4))
158 #define GMOCK_PP_INTERNAL_IS_EMPTY_CASE_0001 ,
159 #define GMOCK_PP_INTERNAL_IF_1(_Then, _Else) _Then
160 #define GMOCK_PP_INTERNAL_IF_0(_Then, _Else) _Else
161 
162 // Because of MSVC treating a token with a comma in it as a single token when
163 // passed to another macro, we need to force it to evaluate it as multiple
164 // tokens. We do that by using a "IDENTITY(MACRO PARENTHESIZED_ARGS)" macro. We
165 // define one per possible macro that relies on this behavior. Note "_Args" must
166 // be parenthesized.
167 #define GMOCK_PP_INTERNAL_INTERNAL_16TH(_1, _2, _3, _4, _5, _6, _7, _8, _9, \
168                                         _10, _11, _12, _13, _14, _15, _16,  \
169                                         ...)                                \
170   _16
171 #define GMOCK_PP_INTERNAL_16TH(_Args) \
172   GMOCK_PP_IDENTITY(GMOCK_PP_INTERNAL_INTERNAL_16TH _Args)
173 #define GMOCK_PP_INTERNAL_INTERNAL_HEAD(_1, ...) _1
174 #define GMOCK_PP_INTERNAL_HEAD(_Args) \
175   GMOCK_PP_IDENTITY(GMOCK_PP_INTERNAL_INTERNAL_HEAD _Args)
176 #define GMOCK_PP_INTERNAL_INTERNAL_TAIL(_1, ...) __VA_ARGS__
177 #define GMOCK_PP_INTERNAL_TAIL(_Args) \
178   GMOCK_PP_IDENTITY(GMOCK_PP_INTERNAL_INTERNAL_TAIL _Args)
179 
180 #define GMOCK_PP_INTERNAL_IBP_IS_VARIADIC_C(...) 1 _
181 #define GMOCK_PP_INTERNAL_IBP_IS_VARIADIC_R_1 1,
182 #define GMOCK_PP_INTERNAL_IBP_IS_VARIADIC_R_GMOCK_PP_INTERNAL_IBP_IS_VARIADIC_C \
183   0,
184 #define GMOCK_PP_INTERNAL_REMOVE_PARENS(...) __VA_ARGS__
185 #define GMOCK_PP_INTERNAL_INC_0 1
186 #define GMOCK_PP_INTERNAL_INC_1 2
187 #define GMOCK_PP_INTERNAL_INC_2 3
188 #define GMOCK_PP_INTERNAL_INC_3 4
189 #define GMOCK_PP_INTERNAL_INC_4 5
190 #define GMOCK_PP_INTERNAL_INC_5 6
191 #define GMOCK_PP_INTERNAL_INC_6 7
192 #define GMOCK_PP_INTERNAL_INC_7 8
193 #define GMOCK_PP_INTERNAL_INC_8 9
194 #define GMOCK_PP_INTERNAL_INC_9 10
195 #define GMOCK_PP_INTERNAL_INC_10 11
196 #define GMOCK_PP_INTERNAL_INC_11 12
197 #define GMOCK_PP_INTERNAL_INC_12 13
198 #define GMOCK_PP_INTERNAL_INC_13 14
199 #define GMOCK_PP_INTERNAL_INC_14 15
200 #define GMOCK_PP_INTERNAL_INC_15 16
201 #define GMOCK_PP_INTERNAL_COMMA_IF_0
202 #define GMOCK_PP_INTERNAL_COMMA_IF_1 ,
203 #define GMOCK_PP_INTERNAL_COMMA_IF_2 ,
204 #define GMOCK_PP_INTERNAL_COMMA_IF_3 ,
205 #define GMOCK_PP_INTERNAL_COMMA_IF_4 ,
206 #define GMOCK_PP_INTERNAL_COMMA_IF_5 ,
207 #define GMOCK_PP_INTERNAL_COMMA_IF_6 ,
208 #define GMOCK_PP_INTERNAL_COMMA_IF_7 ,
209 #define GMOCK_PP_INTERNAL_COMMA_IF_8 ,
210 #define GMOCK_PP_INTERNAL_COMMA_IF_9 ,
211 #define GMOCK_PP_INTERNAL_COMMA_IF_10 ,
212 #define GMOCK_PP_INTERNAL_COMMA_IF_11 ,
213 #define GMOCK_PP_INTERNAL_COMMA_IF_12 ,
214 #define GMOCK_PP_INTERNAL_COMMA_IF_13 ,
215 #define GMOCK_PP_INTERNAL_COMMA_IF_14 ,
216 #define GMOCK_PP_INTERNAL_COMMA_IF_15 ,
217 #define GMOCK_PP_INTERNAL_CALL_MACRO(_Macro, _i, _Data, _element) \
218   _Macro(_i, _Data, _element)
219 #define GMOCK_PP_INTERNAL_FOR_EACH_IMPL_0(_i, _Macro, _Data, _Tuple)
220 #define GMOCK_PP_INTERNAL_FOR_EACH_IMPL_1(_i, _Macro, _Data, _Tuple) \
221   GMOCK_PP_INTERNAL_CALL_MACRO(_Macro, _i, _Data, GMOCK_PP_HEAD _Tuple)
222 #define GMOCK_PP_INTERNAL_FOR_EACH_IMPL_2(_i, _Macro, _Data, _Tuple)    \
223   GMOCK_PP_INTERNAL_CALL_MACRO(_Macro, _i, _Data, GMOCK_PP_HEAD _Tuple) \
224   GMOCK_PP_INTERNAL_FOR_EACH_IMPL_1(GMOCK_PP_INC(_i), _Macro, _Data,    \
225                                     (GMOCK_PP_TAIL _Tuple))
226 #define GMOCK_PP_INTERNAL_FOR_EACH_IMPL_3(_i, _Macro, _Data, _Tuple)    \
227   GMOCK_PP_INTERNAL_CALL_MACRO(_Macro, _i, _Data, GMOCK_PP_HEAD _Tuple) \
228   GMOCK_PP_INTERNAL_FOR_EACH_IMPL_2(GMOCK_PP_INC(_i), _Macro, _Data,    \
229                                     (GMOCK_PP_TAIL _Tuple))
230 #define GMOCK_PP_INTERNAL_FOR_EACH_IMPL_4(_i, _Macro, _Data, _Tuple)    \
231   GMOCK_PP_INTERNAL_CALL_MACRO(_Macro, _i, _Data, GMOCK_PP_HEAD _Tuple) \
232   GMOCK_PP_INTERNAL_FOR_EACH_IMPL_3(GMOCK_PP_INC(_i), _Macro, _Data,    \
233                                     (GMOCK_PP_TAIL _Tuple))
234 #define GMOCK_PP_INTERNAL_FOR_EACH_IMPL_5(_i, _Macro, _Data, _Tuple)    \
235   GMOCK_PP_INTERNAL_CALL_MACRO(_Macro, _i, _Data, GMOCK_PP_HEAD _Tuple) \
236   GMOCK_PP_INTERNAL_FOR_EACH_IMPL_4(GMOCK_PP_INC(_i), _Macro, _Data,    \
237                                     (GMOCK_PP_TAIL _Tuple))
238 #define GMOCK_PP_INTERNAL_FOR_EACH_IMPL_6(_i, _Macro, _Data, _Tuple)    \
239   GMOCK_PP_INTERNAL_CALL_MACRO(_Macro, _i, _Data, GMOCK_PP_HEAD _Tuple) \
240   GMOCK_PP_INTERNAL_FOR_EACH_IMPL_5(GMOCK_PP_INC(_i), _Macro, _Data,    \
241                                     (GMOCK_PP_TAIL _Tuple))
242 #define GMOCK_PP_INTERNAL_FOR_EACH_IMPL_7(_i, _Macro, _Data, _Tuple)    \
243   GMOCK_PP_INTERNAL_CALL_MACRO(_Macro, _i, _Data, GMOCK_PP_HEAD _Tuple) \
244   GMOCK_PP_INTERNAL_FOR_EACH_IMPL_6(GMOCK_PP_INC(_i), _Macro, _Data,    \
245                                     (GMOCK_PP_TAIL _Tuple))
246 #define GMOCK_PP_INTERNAL_FOR_EACH_IMPL_8(_i, _Macro, _Data, _Tuple)    \
247   GMOCK_PP_INTERNAL_CALL_MACRO(_Macro, _i, _Data, GMOCK_PP_HEAD _Tuple) \
248   GMOCK_PP_INTERNAL_FOR_EACH_IMPL_7(GMOCK_PP_INC(_i), _Macro, _Data,    \
249                                     (GMOCK_PP_TAIL _Tuple))
250 #define GMOCK_PP_INTERNAL_FOR_EACH_IMPL_9(_i, _Macro, _Data, _Tuple)    \
251   GMOCK_PP_INTERNAL_CALL_MACRO(_Macro, _i, _Data, GMOCK_PP_HEAD _Tuple) \
252   GMOCK_PP_INTERNAL_FOR_EACH_IMPL_8(GMOCK_PP_INC(_i), _Macro, _Data,    \
253                                     (GMOCK_PP_TAIL _Tuple))
254 #define GMOCK_PP_INTERNAL_FOR_EACH_IMPL_10(_i, _Macro, _Data, _Tuple)   \
255   GMOCK_PP_INTERNAL_CALL_MACRO(_Macro, _i, _Data, GMOCK_PP_HEAD _Tuple) \
256   GMOCK_PP_INTERNAL_FOR_EACH_IMPL_9(GMOCK_PP_INC(_i), _Macro, _Data,    \
257                                     (GMOCK_PP_TAIL _Tuple))
258 #define GMOCK_PP_INTERNAL_FOR_EACH_IMPL_11(_i, _Macro, _Data, _Tuple)   \
259   GMOCK_PP_INTERNAL_CALL_MACRO(_Macro, _i, _Data, GMOCK_PP_HEAD _Tuple) \
260   GMOCK_PP_INTERNAL_FOR_EACH_IMPL_10(GMOCK_PP_INC(_i), _Macro, _Data,   \
261                                      (GMOCK_PP_TAIL _Tuple))
262 #define GMOCK_PP_INTERNAL_FOR_EACH_IMPL_12(_i, _Macro, _Data, _Tuple)   \
263   GMOCK_PP_INTERNAL_CALL_MACRO(_Macro, _i, _Data, GMOCK_PP_HEAD _Tuple) \
264   GMOCK_PP_INTERNAL_FOR_EACH_IMPL_11(GMOCK_PP_INC(_i), _Macro, _Data,   \
265                                      (GMOCK_PP_TAIL _Tuple))
266 #define GMOCK_PP_INTERNAL_FOR_EACH_IMPL_13(_i, _Macro, _Data, _Tuple)   \
267   GMOCK_PP_INTERNAL_CALL_MACRO(_Macro, _i, _Data, GMOCK_PP_HEAD _Tuple) \
268   GMOCK_PP_INTERNAL_FOR_EACH_IMPL_12(GMOCK_PP_INC(_i), _Macro, _Data,   \
269                                      (GMOCK_PP_TAIL _Tuple))
270 #define GMOCK_PP_INTERNAL_FOR_EACH_IMPL_14(_i, _Macro, _Data, _Tuple)   \
271   GMOCK_PP_INTERNAL_CALL_MACRO(_Macro, _i, _Data, GMOCK_PP_HEAD _Tuple) \
272   GMOCK_PP_INTERNAL_FOR_EACH_IMPL_13(GMOCK_PP_INC(_i), _Macro, _Data,   \
273                                      (GMOCK_PP_TAIL _Tuple))
274 #define GMOCK_PP_INTERNAL_FOR_EACH_IMPL_15(_i, _Macro, _Data, _Tuple)   \
275   GMOCK_PP_INTERNAL_CALL_MACRO(_Macro, _i, _Data, GMOCK_PP_HEAD _Tuple) \
276   GMOCK_PP_INTERNAL_FOR_EACH_IMPL_14(GMOCK_PP_INC(_i), _Macro, _Data,   \
277                                      (GMOCK_PP_TAIL _Tuple))
278 
279 #endif  // GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_GMOCK_PP_H_
280