large-locals.c

#include <stdio.h>
#include <unistd.h>

struct large_struct {
    void* a[1024];
};

static void foo() {
    struct large_struct r;
    // call any function that is guaranteed to be not inlined
    write(-1, (void*) &r, 1);
}

static void bar(int n) {
    if (n > 0) {
        foo();

        bar(n - 1);
    }
}

// crashes when compiled by clang or llvm-gcc with -O2
// works fine with -O0 or in gcc
// reported to LLVM: http://llvm.org/bugs/show_bug.cgi?id=13700
int main() {
    int ns[] = { 100, 200, 500, 1000, 2000, 5000, 10000, 20000, 50000, 100000 };
    for (int i = 0; i < sizeof(ns) / sizeof(int); ++i) {
        printf("%d\n", ns[i]);
        bar(ns[i]);
    }
    return 0;
}