clang-tests/gcc-4_2-testsuite/src/gcc.apple/block-readweakgc.c

/* APPLE LOCAL file radar 5882266 */
/* { dg-do run { target *-*-darwin[1-2][0-9]* } } */
/* { dg-options "-mmacosx-version-min=10.5 -ObjC -fobjc-gc -framework Foundation" { target *-*-darwin* } } */
/* { dg-skip-if "" { powerpc*-*-darwin* } { "-m64" } { "" } } */

#import <Foundation/Foundation.h>
void * _NSConcreteStackBlock;

int GlobalInt = 0;
int GlobalInt2 = 0;

id objc_assign_weak(id value, id *location) {
    GlobalInt = 1;
    *location = value;
    return value;
}

id objc_read_weak(id *location) {
    GlobalInt2 = 1;
    return *location;
}


void (^__weak Henry)(void);

int main(int argc, char *argv[]) {
    // an object should not be retained within a stack Block
    void (^local)(void);
    __block int i = 10;
    Henry = ^ { ++i; }; 
    local = Henry;
    if (GlobalInt2 == 1) {
        printf("%s: success\n", argv[0]);
        exit(0);
    }
    else {
        printf("%s: problem with weak write-barrier assignment of stack block\n", argv[0]);
    }
    exit(1);
}