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