1#ifndef ANDROID_PDX_RPC_MACROS_H_ 2#define ANDROID_PDX_RPC_MACROS_H_ 3 4// Macros to apply other macros over all elements in a list. 5// 6// For example, for a macro A(x) and B(x, y): 7// - FOR_EACH(A, 1, 2, 3) -> A(1) A(2) A(3). 8// - FOR_EACH_BINARY(B, z, 1, 2, 3) -> B(z, 1) B(z, 2) B(z, 3) 9// - FOR_EACH_LIST(A, 1, 2, 3) -> A(1), B(2), C(3) 10// - FOR_EACH_BINARY_LIST(B, z, 1, 2, 3) -> B(z, 1), B(z, 2), B(z, 3) 11// 12// Empty lists are supported and will produce no output. 13 14// Recursive expansion macros. 15#define _PDX_EXPAND0(...) __VA_ARGS__ 16#define _PDX_EXPAND1(...) _PDX_EXPAND0(_PDX_EXPAND0(_PDX_EXPAND0(__VA_ARGS__))) 17#define _PDX_EXPAND2(...) _PDX_EXPAND1(_PDX_EXPAND1(_PDX_EXPAND1(__VA_ARGS__))) 18#define _PDX_EXPAND3(...) _PDX_EXPAND2(_PDX_EXPAND2(_PDX_EXPAND2(__VA_ARGS__))) 19#define _PDX_EXPAND4(...) _PDX_EXPAND3(_PDX_EXPAND3(_PDX_EXPAND3(__VA_ARGS__))) 20#define _PDX_EXPAND(...) _PDX_EXPAND4(_PDX_EXPAND4(_PDX_EXPAND4(__VA_ARGS__))) 21 22// Required to workaround a bug in the VC++ preprocessor. 23#define _PDX_INDIRECT_EXPAND(macro, args) macro args 24 25// Defines a step separation for macro expansion. 26#define _PDX_SEPARATOR 27 28// Clears any remaining contents wrapped in parentheses. 29#define _PDX_CLEAR(...) 30 31// Introduces a first dummy argument and _PDX_CLEAR as second argument. 32#define _PDX_CLEAR_IF_LAST() _, _PDX_CLEAR 33 34// Returns the first argument of a list. 35#define _PDX_FIRST_ARG(first, ...) first 36 37// Returns the second argument of a list. 38#define _PDX_SECOND_ARG(_, second, ...) second 39 40// Expands the arguments and introduces a separator. 41#define _PDX_EXPAND_NEXT_FUNC(_, next_func, ...) \ 42 _PDX_INDIRECT_EXPAND(_PDX_SECOND_ARG, (_, next_func)) \ 43 _PDX_SEPARATOR 44 45// Returns next_func if the next element is not (), or _PDX_CLEAR 46// otherwise. 47// 48// _PDX_CLEAR_IF_LAST inserts an extra first dummy argument if peek is (). 49#define _PDX_NEXT_FUNC(next_element, next_func) \ 50 _PDX_EXPAND_NEXT_FUNC(_PDX_CLEAR_IF_LAST next_element, next_func) 51 52// Macros for the unary version of PDX_FOR_EACH. 53 54// Applies the unary macro. Duplicated for macro recursive expansion. 55#define _PDX_APPLY_1(macro, head, next, ...) \ 56 macro(head) _PDX_NEXT_FUNC(next, _PDX_APPLY_2)(macro, next, __VA_ARGS__) 57 58// Applies the unary macro. Duplicated for macro recursive expansion. 59#define _PDX_APPLY_2(macro, head, next, ...) \ 60 macro(head) _PDX_NEXT_FUNC(next, _PDX_APPLY_1)(macro, next, __VA_ARGS__) 61 62// Stops expansion if __VA_ARGS__ is empty, calling _PDX_APPLY_1 63// otherwise. 64#define _PDX_HANDLE_EMPTY_ARGS(macro, ...) \ 65 _PDX_NEXT_FUNC(_PDX_FIRST_ARG(__VA_ARGS__()), _PDX_APPLY_1) \ 66 (macro, __VA_ARGS__, ()) 67 68// Applies a unary macro over all the elements in a list. 69#define PDX_FOR_EACH(macro, ...) \ 70 _PDX_EXPAND(_PDX_HANDLE_EMPTY_ARGS(macro, __VA_ARGS__)) 71 72// Applies the unary macro at the end of a list. Duplicated for macro recursive 73// expansion. 74#define _PDX_APPLY_LIST_1(macro, head, next, ...) \ 75 , macro(head) \ 76 _PDX_NEXT_FUNC(next, _PDX_APPLY_LIST_2)(macro, next, __VA_ARGS__) 77 78// Applies the unary macro at the end of a list. Duplicated for macro recursive 79// expansion. 80#define _PDX_APPLY_LIST_2(macro, head, next, ...) \ 81 , macro(head) \ 82 _PDX_NEXT_FUNC(next, _PDX_APPLY_LIST_1)(macro, next, __VA_ARGS__) 83 84// Applies the unary macro at the start of a list. 85#define _PDX_APPLY_LIST_0(macro, head, next, ...) \ 86 macro(head) _PDX_NEXT_FUNC(next, _PDX_APPLY_LIST_1)(macro, next, __VA_ARGS__) 87 88// Stops expansion if __VA_ARGS__ is empty, calling _PDX_APPLY_LIST_0 89// otherwise. 90#define _PDX_HANDLE_EMPTY_LIST(macro, ...) \ 91 _PDX_NEXT_FUNC(_PDX_FIRST_ARG(__VA_ARGS__()), _PDX_APPLY_LIST_0) \ 92 (macro, __VA_ARGS__, ()) 93 94// Applies a unary macro over all the elements in a list. 95#define PDX_FOR_EACH_LIST(macro, ...) \ 96 _PDX_EXPAND(_PDX_HANDLE_EMPTY_LIST(macro, __VA_ARGS__)) 97 98// Macros for the binary version of PDX_FOR_EACH. 99 100// Applies the binary macro. Duplicated for macro recursive expansion. 101#define _PDX_APPLY_BINARY_1(macro, arg, head, next, ...) \ 102 macro(arg, head) \ 103 _PDX_NEXT_FUNC(next, _PDX_APPLY_BINARY_2)(macro, arg, next, __VA_ARGS__) 104 105// Applies the binary macro. Duplicated for macro recursive expansion. 106#define _PDX_APPLY_BINARY_2(macro, arg, head, next, ...) \ 107 macro(arg, head) \ 108 _PDX_NEXT_FUNC(next, _PDX_APPLY_BINARY_1)(macro, arg, next, __VA_ARGS__) 109 110// Version of _PDX_HANDLE_EMPTY_ARGS that takes 1 fixed argument for a 111// binary macro. 112#define _PDX_HANDLE_EMPTY_ARGS_BINARY(macro, arg, ...) \ 113 _PDX_NEXT_FUNC(_PDX_FIRST_ARG(__VA_ARGS__()), _PDX_APPLY_BINARY_1) \ 114 (macro, arg, __VA_ARGS__, ()) 115 116// Applies a binary macro over all the elements in a list and a given argument. 117#define PDX_FOR_EACH_BINARY(macro, arg, ...) \ 118 _PDX_EXPAND(_PDX_HANDLE_EMPTY_ARGS_BINARY(macro, arg, __VA_ARGS__)) 119 120// Applies the binary macro at the end of a list. Duplicated for macro recursive 121// expansion. 122#define _PDX_APPLY_BINARY_LIST_1(macro, arg, head, next, ...) \ 123 , macro(arg, head) _PDX_NEXT_FUNC(next, _PDX_APPLY_BINARY_LIST_2)( \ 124 macro, arg, next, __VA_ARGS__) 125 126// Applies the binary macro at the end of a list. Duplicated for macro recursive 127// expansion. 128#define _PDX_APPLY_BINARY_LIST_2(macro, arg, head, next, ...) \ 129 , macro(arg, head) _PDX_NEXT_FUNC(next, _PDX_APPLY_BINARY_LIST_1)( \ 130 macro, arg, next, __VA_ARGS__) 131 132// Applies the binary macro at the start of a list. Duplicated for macro 133// recursive expansion. 134#define _PDX_APPLY_BINARY_LIST_0(macro, arg, head, next, ...) \ 135 macro(arg, head) _PDX_NEXT_FUNC(next, _PDX_APPLY_BINARY_LIST_1)( \ 136 macro, arg, next, __VA_ARGS__) 137 138// Version of _PDX_HANDLE_EMPTY_LIST that takes 1 fixed argument for a 139// binary macro. 140#define _PDX_HANDLE_EMPTY_LIST_BINARY(macro, arg, ...) \ 141 _PDX_NEXT_FUNC(_PDX_FIRST_ARG(__VA_ARGS__()), _PDX_APPLY_BINARY_LIST_0) \ 142 (macro, arg, __VA_ARGS__, ()) 143 144// Applies a binary macro over all the elements in a list and a given argument. 145#define PDX_FOR_EACH_BINARY_LIST(macro, arg, ...) \ 146 _PDX_EXPAND(_PDX_HANDLE_EMPTY_LIST_BINARY(macro, arg, __VA_ARGS__)) 147 148#endif // ANDROID_PDX_RPC_MACROS_H_ 149