/* * Written by J.T. Conklin * Public domain. */ /* * str*() regression suite * * Trivial str*() implementations can be audited by hand. Optimized * versions that unroll loops, use naturally-aligned memory acesses, * and "magic" arithmetic sequences to detect zero-bytes, written in * assembler are much harder to validate. This program attempts to * catch the corner cases. * * BUGS: * Misssing checks for strncpy, strncat, strncmp, etc. * * TODO: * Use mmap/mprotect to ensure the functions don't access memory * across page boundaries. * * Consider generating tables programmatically. It would reduce * the size, but it's also one more thing to go wrong. * * Share tables between strlen, strcpy, and strcat? * Share tables between strchr and strrchr? */ #include #include void check_strcmp(void); void check_strcmp(void) { /* try to trick the compiler */ int (*f)(const char *, const char *s) = strcmp; int a0; int a1; int t; char buf0[64]; char buf1[64]; int ret; struct tab { const char* val0; const char* val1; int ret; }; const struct tab tab[] = { { "", "", 0 }, { "a", "a", 0 }, { "a", "b", -1 }, { "b", "a", +1 }, { "", "a", -1 }, { "a", "", +1 }, { "aa", "aa", 0 }, { "aa", "ab", -1 }, { "ab", "aa", +1 }, { "a", "aa", -1 }, { "aa", "a", +1 }, { "aaa", "aaa", 0 }, { "aaa", "aab", -1 }, { "aab", "aaa", +1 }, { "aa", "aaa", -1 }, { "aaa", "aa", +1 }, { "aaaa", "aaaa", 0 }, { "aaaa", "aaab", -1 }, { "aaab", "aaaa", +1 }, { "aaa", "aaaa", -1 }, { "aaaa", "aaa", +1 }, { "aaaaa", "aaaaa", 0 }, { "aaaaa", "aaaab", -1 }, { "aaaab", "aaaaa", +1 }, { "aaaa", "aaaaa", -1 }, { "aaaaa", "aaaa", +1 }, { "aaaaaa", "aaaaaa", 0 }, { "aaaaaa", "aaaaab", -1 }, { "aaaaab", "aaaaaa", +1 }, { "aaaaa", "aaaaaa", -1 }, { "aaaaaa", "aaaaa", +1 }, }; for (a0 = 0; a0 < sizeof(long); ++a0) { for (a1 = 0; a1 < sizeof(long); ++a1) { for (t = 0; t < (sizeof(tab) / sizeof(tab[0])); ++t) { memcpy(&buf0[a0], tab[t].val0, strlen(tab[t].val0) + 1); memcpy(&buf1[a1], tab[t].val1, strlen(tab[t].val1) + 1); ret = f(&buf0[a0], &buf1[a1]); assert ((ret == 0 && tab[t].ret == 0) || (ret < 0 && tab[t].ret < 0) || (ret > 0 && tab[t].ret > 0)); } } } } int main(void) { check_strcmp(); return 0; }