More than one __attribute__ in C with gcc

Question

Can you add more than one attribute to an identifier in C with gcc? Here is what I have now. I left out the include statements because they get scramble in the post. If there is a way to add two, what is the general syntax, and how can I do it both with the defintion, and with a prototype? Thank you. :-)

main() {       printf("In Main\n");   }   __attribute__ ((constructor)) void beforeMain(void)   {       printf("Before Main\n");   }   

Answer 1

There are two different ways of specifying multiple attributes in C with GCC:

#include <stdio.h>  // Attributes in prototypes: __attribute__((constructor, weak)) void beforeMain(void); __attribute__((constructor)) __attribute__((weak)) void beforeMain2(void);  int main(){     printf("In Main\n");     return 0; }  // Attributes in definitions: __attribute__((constructor, weak)) void beforeMain(void){     printf("Before Main 1\n"); }  __attribute__((constructor)) __attribute__((weak)) void beforeMain2(void){     printf("Before Main 2\n"); } 

The code above compiles and runs correctly for me under gcc version 4.4.3.

Answer 2

You can use multiple __attribute__ specifiers separated by spaces.

char s[3] __attribute__((aligned(32))) __attribute__((weak));