setjmp does not restore local variables

clang.out

$ clang setjmp-test.c
$ ./a.out
setjmp normal execution path, level: 0, prev_jmp: 0x0
setjmp normal execution path, level: 1, prev_jmp: 0x7fff5df345f0
level is 2, perform longjmp!
setjmp exception execution path, level: 1, prev_jmp: 0x7fff5df345f0
prev_jmp is not empty, continue with longjmp!
setjmp exception execution path, level: 0, prev_jmp: 0x0
Exiting setjmp function, level: 0, prev_jmp: 0x0

emcc.out

$ emcc setjmp-test.c
$ node a.out.js
setjmp normal execution path, level: 0, prev_jmp: (nil)
setjmp normal execution path, level: 1, prev_jmp: 0x14
level is 2, perform longjmp!
setjmp exception execution path, level: 1, prev_jmp: 0x14
prev_jmp is not empty, continue with longjmp!
setjmp exception execution path, level: 1, prev_jmp: 0x14
prev_jmp is not empty, continue with longjmp!
setjmp exception execution path, level: 1, prev_jmp: 0x14
prev_jmp is not empty, continue with longjmp!
setjmp exception execution path, level: 1, prev_jmp: 0x14
prev_jmp is not empty, continue with longjmp!
setjmp exception execution path, level: 1, prev_jmp: 0x14
prev_jmp is not empty, continue with longjmp!
setjmp exception execution path, level: 1, prev_jmp: 0x14
prev_jmp is not empty, continue with longjmp!
(this is an infinite loop)

setjmp-test.c

#include <setjmp.h>
#include <stdio.h>

typedef struct {
  jmp_buf* jmp;
} jmp_state;

void setjmp_func(jmp_state* s, int level) {
  jmp_buf* prev_jmp = s->jmp;
  jmp_buf c_jmp;

  if (level == 2) {
    printf("level is 2, perform longjmp!\n");
    longjmp(*(s->jmp), 1);
  }

  if (setjmp(c_jmp) == 0) {
    printf("setjmp normal execution path, level: %d, prev_jmp: %p\n", level, prev_jmp);
    s->jmp = &c_jmp;
    setjmp_func(s, level + 1);
  } else {
    printf("setjmp exception execution path, level: %d, prev_jmp: %p\n", level, prev_jmp);
    if (prev_jmp) {
      printf("prev_jmp is not empty, continue with longjmp!\n");
      s->jmp = prev_jmp;
      longjmp(*(s->jmp), 1);
    }
  }

  printf("Exiting setjmp function, level: %d, prev_jmp: %p\n", level, prev_jmp);
}

int main(int argc, char *argv[]) {
  jmp_state s;
  s.jmp = NULL;

  setjmp_func(&s, 0);

  return 0;
}