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Closures/Value capture: Difference between revisions
→Function image copying approach
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<lang c>#include <stdio.h>
#include <stdlib.h>▼
#include <string.h>
▲#include <stdlib.h>
#include <sys/mman.h>
typedef int (*f_int)();
#define TAG 0xdeadbeef
int _tmpl() {
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}
#define PROT (PROT_EXEC | PROT_WRITE)
#define FLAGS (MAP_PRIVATE | MAP_ANONYMOUS)
f_int dupf(int v)
{
size_t len = (void*)dupf - (void*)_tmpl;
f_int ret =
char *p;
if(ret == MAP_FAILED) {
perror("mmap");
exit(-1);
}
memcpy(ret, _tmpl, len);
for (p = (char*)ret; p < (char*)ret + len - sizeof(int); p++)
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return ret;
}
int main()
{
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int i;
for (i = 0; i < 10; i++) funcs[i] = dupf(i);
for (i = 0; i < 9; i++)
printf("func[%d]: %d\n", i, funcs[i]());
return 0;
}</lang>output<lang>func[0]: 0
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