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// Copyright 2015 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 <stdio.h>
#include <emscripten.h>
#include <assert.h>
__attribute__((noinline)) int calc(int x) {
printf("..%d..\n", x);
if (x == 0) {
// We reached the desired number of stack frames. Log out the stack trace
// for purposes of debugging this test.
char buffer[10000];
emscripten_get_callstack(EM_LOG_JS_STACK, buffer, 10000);
int newlines = 0;
char *b = buffer;
while (*b) {
if (*b == '\n') newlines++;
b++;
}
// The runtime adds more frames from JS, so do not look for a specific
// number, but ensure it is quite large.
if (newlines > 40) newlines = 40;
printf("stack: %s => %d, sleeping...\n", buffer, newlines);
// Sleep to test the saving of a fairly deep stack, including locals along
// the way.
emscripten_sleep(1);
printf("..and we're back, returning %d!\n", newlines);
// Return a value to test it passing through all the stack frames to the
// caller, after the sleep.
return newlines;
}
// Keep the recursion by passing the function pointer between C++ and JS, so
// that we have a deeply nested stack.
int (*fp)(int) = (int(*)(int))EM_ASM_PTR({
return $0;
}, &calc);
return fp(x - 1);
}
int main() {
// Ensure at least 40 stack frames.
int x = 40;
int result = calc(x);
printf("calc(%d) = %d\n", x, result);
assert(result == 40);
return 0;
}
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