# tests for compiler properties # set -Werror so we can't ignore unused attribute warnings set (CMAKE_REQUIRED_FLAGS "-Werror") CHECK_C_SOURCE_COMPILES(" int foo(int) __attribute__ ((ifunc(\"foo_i\"))); int f1(int i) { return i; } void (*foo_i()) { return f1; } int main(void) { return 0; } " HAS_C_ATTR_IFUNC) unset(CMAKE_REQUIRED_FLAGS)