blob: 030abba377ac82b602c519daf6823cc0cb3e9846 [file] [log] [blame]
* Copyright 2018 The Emscripten Authors. All rights reserved.
* Emscripten is available under two separate licenses, the MIT license and the
* University of Illinois/NCSA Open Source License. Both these licenses can be
* found in the LICENSE file.
#include <stdlib.h>
#include <setjmp.h>
#include <stdio.h>
#include <assert.h>
#define abs(x) ((x) < 0 ? (-x) : (x))
// A minor stack change is ignorable (e.g., printf)
#define MINOR 100
// A major stack change must not happen
#define MAJOR 1000
jmp_buf jb;
__attribute__((noinline)) int get_stack()
int dummy;
int ptr = (int)&dummy;
return ptr;
__attribute__((noinline)) void bar()
printf("before longjmp: %d\n", get_stack());
longjmp(jb, 1);
volatile void* temp;
__attribute__((noinline)) void foo()
temp = alloca(MAJOR);
printf("major allocation at: %d\n", (int)temp);
#ifdef __asmjs__
// asmjs stack grows up, but wasm backend stack grows down, so the delta
// between get_stack() and temp isn't related to the size of the alloca for
// wasm backend
assert(abs(get_stack() - (int)temp) >= MAJOR);
int main()
int before = get_stack();
printf("before setjmp: %d\n", before);
if (!setjmp(jb)) {
return 0;
} else {
int after = get_stack();
printf("before setjmp: %d\n", after);
assert(abs(after - before) < MINOR); // stack has been unwound (but may have minor printf changes
return 1;