Change Details

cap_net.h uses "#define cap_f(chan, a) f(a)" to call the conventional service function with the first argument of cap_f() dropped for compatibility with the environment where the casper service is unavailable. However, this function-like macro does not work when the arguments contains C99 compound literals, such as f(chan, (int[]){1,2,3}). The following is a typical example: ``` error = cap_getaddrinfo(capnet, "192.168.0.1", "100", &(struct addrinfo){ .ai_family = AF_INET, .ai_flags = AI_NUMERICHOST }, &res); ``` Using cap_f(chan, ...) and __VA_ARGS__ in C99 seems a reasonable solution for this problem. While there is a workaround using parenthesis around the compound literal like f(chan, ((int[]){1,2,3})), it is not intuitive and the above example works when the cap_net is available and f() is defined as a function. The possible moot point is that __VA_ARGS__ cannot control how many arguments are passed at the macro level, and "chan" is not protected. However, "chan" is less likely to be written in compound literal, and the function prototype should check the remaining arguments.

cap_net.h uses "#define cap_f(chan, a) f(a)" to call the conventional service function with the first argument of cap_f() dropped for compatibility with the environment where the casper service is unavailable. However, this function-like macro does not work when the arguments contains C99 compound literals, such as f(chan, (int[]){1,2,3}). The following is a typical example: ``` error = cap_getaddrinfo(capnet, "192.168.0.1", "100", &(struct addrinfo){ .ai_family = AF_INET, .ai_flags = AI_NUMERICHOST }, &res); ``` Using cap_f(chan, ...) and `__VA_ARGS__` in C99 seems a reasonable solution for this problem. While there is a workaround using parenthesis around the compound literal like f(chan, ((int[]){1,2,3})), it is not intuitive and the above example works when the cap_net is available and f() is defined as a function. The possible moot point is that `__VA_ARGS__` cannot control how many arguments are passed at the macro level, and "chan" is not protected. However, "chan" is less likely to be written in compound literal, and the function prototype should check the remaining arguments.

cap_net.h uses "#define cap_f(chan, a) f(a)" to call the conventional service function with the first argument of cap_f() dropped for compatibility with the environment where the casper service is unavailable. However, this function-like macro does not work when the arguments contains C99 compound literals, such as f(chan, (int[]){1,2,3}). The following is a typical example: ``` error = cap_getaddrinfo(capnet, "192.168.0.1", "100", &(struct addrinfo){ .ai_family = AF_INET, .ai_flags = AI_NUMERICHOST }, &res); ``` Using cap_f(chan, ...) and `__VA_ARGS__` in C99 seems a reasonable solution for this problem. While there is a workaround using parenthesis around the compound literal like f(chan, ((int[]){1,2,3})), it is not intuitive and the above example works when the cap_net is available and f() is defined as a function. The possible moot point is that `__VA_ARGS__` cannot control how many arguments are passed at the macro level, and "chan" is not protected. However, "chan" is less likely to be written in compound literal, and the function prototype should check the remaining arguments.