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__attribute__((used)) function attribute

This function attribute informs the compiler that a static function is to be retained in the object file, even if it is unreferenced.

Functions marked with __attribute__((used)) are tagged in the object file to avoid removal by linker unused section removal.


Static variables can also be marked as used, by using __attribute__((used)).


static int lose_this(int);
static int keep_this(int) __attribute__((used));     // retained in object file
static int keep_this (int arg) {
  return (arg+1);
static int keep_this_too(int) __attribute__((used)); // retained in object file
static int keep_this_too (int arg) {
  return (arg-1);

int main (void) {
  for (;;);