This commit is contained in:
pommicket 2022-02-16 15:41:30 -05:00
parent c6f1a399af
commit 3a3f6cc424
4 changed files with 262 additions and 11 deletions

View file

@ -2,9 +2,32 @@
#include <math.h>
#include <stdio.h>
#include <signal.h>
#include <stdlib.h>
int main(int argc, char **argv) {
raise(SIGKILL);
int compar(const void *a, const void *b) {
int i = *(int *)a;
int j = *(int *)b;
if (i < j) return -1;
if (i > j) return 1;
return 0;
}
int main(int argc, char **argv) {
ldiv_t l = ldiv(1000000000007, 5937448);
printf("%ld %ld\n",l.quot,l.rem);
int nums[10] = {8,34,1086,3872,-123,5873,3843,1762,INT_MAX,INT_MIN};
int i;
for (i = 0; i < 10; ++i) nums[i] = abs(nums[i]);
qsort(nums, 10, sizeof(int), compar);
for (i = 0; i < 10; ++i) printf("%d ", nums[i]);
printf("\n");
int search = 34;
int *p = bsearch(&search, nums, 10, sizeof(int), compar);
if (p)
printf("Found %d\n",*p);
else
printf("No match\n");
return 0;
}

View file

@ -108,6 +108,23 @@ int getpid(void) {
return __syscall(39, 0, 0, 0, 0, 0, 0);
}
int fork(void) {
return __syscall(57, 0, 0, 0, 0, 0, 0);
}
int execve(const char *pathname, char *const argv[], char *const envp[]) {
return __syscall(59, pathname, argv, envp, 0, 0, 0);
}
#define _WEXITSTATUS(status) (((status) & 0xff00) >> 8)
#define _WIFEXITED(status) (__WTERMSIG(status) == 0)
#define _WIFSIGNALED(status) \
(((signed char) (((status) & 0x7f) + 1) >> 1) > 0)
int wait4(int pid, int *status, int options, struct rusage *rusage) {
return __syscall(61, pid, status, options, rusage, 0, 0);
}
#define SIGABRT 6
#define SIGFPE 8
#define SIGKILL 9
@ -184,7 +201,13 @@ int munmap(void *addr, size_t length) {
return __syscall(11, addr, length, 0, 0, 0, 0);
}
#define MREMAP_MAYMOVE 1
void *_mremap(void *addr, size_t old_size, size_t new_size, int flags) {
return __syscall(25, addr, old_size, new_size, flags, 0, 0);
}
void *malloc(size_t n) {
if (!n) return NULL;
void *memory;
size_t bytes = n + 16;
memory = mmap(0, bytes, PROT_READ|PROT_WRITE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
@ -194,17 +217,12 @@ void *malloc(size_t n) {
}
void free(void *ptr) {
if (!ptr) return;
uint64_t *memory = (char *)ptr - 16;
uint64_t size = *memory;
munmap(memory, size);
}
void *calloc(size_t nmemb, size_t size) {
if (nmemb > 0xffffffffffffffff / size)
return NULL;
return malloc(nmemb * size);
}
size_t strlen(char *s) {
char *t = s;
@ -212,6 +230,13 @@ size_t strlen(char *s) {
return t - s;
}
void *memcpy(void *s1, const void *s2, size_t n) {
char *p = s1, *end = p + n, *q = s2;
while (p < end)
*p++ = *q++;
return s1;
}
int isspace(int c) {
return c == ' ' || c == '\f' || c == '\n' || c == '\r' || c == '\t' || c == '\v';
}
@ -430,10 +455,30 @@ double strtod(const char *nptr, char **endptr) {
return sum * sign;
}
char *strerror(int errnum) {
switch (errnum) {
case ERANGE: return "Range error";
case EDOM: return "Domain error";
case EIO: return "I/O error";
}
return "Other error";
}
typedef void (*_ExitHandler)(void);
_ExitHandler _exit_handlers[33];
int _n_exit_handlers;
void exit(int status) {
int i;
for (i = _n_exit_handlers - 1; i >= 0; --i)
_exit_handlers[i]();
_Exit(status);
}
int main();
static char **_envp;
static uint64_t _rand_seed;
int _main(int argc, char **argv) {
int i;
@ -445,6 +490,12 @@ int _main(int argc, char **argv) {
stdout = &_stdout;
stderr = &_stderr;
/*
"If rand is called before any calls to srand have been made,
the same sequence shall be generated as when srand is first
called with a seed value of 1." C89 § 4.10.2.2
*/
_rand_seed = 1;
// initialize powers of 10
_powers_of_10 = _powers_of_10_dat + _NPOW10;
for (i = 0; i < _NPOW10; ++i) {
@ -464,7 +515,7 @@ int _main(int argc, char **argv) {
p.exponent -= 1;
}
return main(argc, argv);
exit(main(argc, argv));
}

View file

@ -1683,7 +1683,8 @@ int _fopen_flags_from_mode(const char *mode) {
}
FILE *_FILE_from_fd(int fd) {
FILE *fp = calloc(1, sizeof(FILE));
FILE *fp = malloc(sizeof(FILE));
// NB: our malloc implementation returns zeroed memory
fp->fd = fd;
return fp;
}
@ -2274,7 +2275,9 @@ int scanf(const char *format, ...) {
}
void perror(const char *s); // @TODO
void perror(const char *s) {
printf("%s: %s\n", s, strerror(errno));
}
#undef STB_SPRINTF_MIN

View file

@ -3,6 +3,21 @@
#include <stdc_common.h>
#define EXIT_FAILURE (-1)
#define EXIT_SUCCESS 0
#define RAND_MAX 2147483647
// @NONSTANDARD: we don't define MB_CUR_MAX or any of the mbtowc functions
typedef struct {
int quot;
int rem;
} div_t;
typedef struct {
long quot;
long rem;
} ldiv_t;
char *getenv(const char *name) {
int i, j;
for (i = 0; _envp[i]; ++i) {
@ -16,4 +31,163 @@ char *getenv(const char *name) {
return NULL;
}
double atof(const char *nptr) {
return strtod(nptr, NULL);
}
int atoi(const char *nptr) {
return _clamp_long_to_int(strtol(nptr, NULL, 10));
}
long atol(const char *nptr) {
return strtol(nptr, NULL, 10);
}
int rand(void) {
// https://en.wikipedia.org/wiki/Linear_congruential_generator
// we're using musl/newlib's constants
_rand_seed = 6364136223846793005 * _rand_seed + 1;
return _rand_seed >> 33;
}
void srand(unsigned seed) {
_rand_seed = seed;
}
void *calloc(size_t nmemb, size_t size) {
if (nmemb > 0xffffffffffffffff / size)
return NULL;
// NB: our malloc implementation returns zeroed memory
return malloc(nmemb * size);
}
void *realloc(void *ptr, size_t size) {
if (!ptr) return malloc(size);
if (!size) {
free(ptr);
return NULL;
}
uint64_t *memory = (char *)ptr - 16;
uint64_t old_size = *memory;
uint64_t *new_memory = _mremap(memory, old_size, size, MREMAP_MAYMOVE);
if ((uint64_t)new_memory > 0xffffffffffff0000) return NULL;
*new_memory = size;
return (char *)new_memory + 16;
}
int atexit(void (*func)(void)) {
if (_n_exit_handlers >= 32) return -1;
_exit_handlers[_n_exit_handlers++] = func;
return 0;
}
int system(const char *string) {
if (!string) return 1;
int pid = fork();
if (pid < 0) {
return -1;
} else if (pid == 0) {
// child
char *argv[] = {
"/bin/sh",
"-c",
0,
0
};
argv[2] = string;
execve("/bin/sh", argv, _envp);
// on success, execve does not return.
_Exit(-1);
} else {
// parent
int status = 0;
int ret = wait4(pid, &status, 0, NULL);
if (ret != pid) return -1;
if (_WIFSIGNALED(status)) return -1;
return _WEXITSTATUS(status);
}
}
void *bsearch(const void *key, const void *base, size_t nmemb, size_t size, int (*compar)(const void *, const void *)) {
size_t lo = 0;
size_t hi = nmemb;
while (lo < hi) {
size_t mid = (lo + hi) >> 1;
void *elem = (char *)base + mid * size;
int cmp = compar(key, elem);
if (cmp < 0) {
// key < elem
hi = mid;
} else if (cmp) {
// key > elem
lo = mid + 1;
} else {
return elem;
}
}
return NULL;
}
void qsort(void *base, size_t nmemb, size_t size, int (*compar)(const void *, const void *)) {
// quicksort
if (nmemb < 2) return;
void *temp = malloc(size);
void *mid = (char *)base + ((nmemb >> 1) * size); // choose middle element to speed up sorting an already-sorted array
size_t pivot_index = 0, i;
for (i = 0; i < nmemb; ++i) {
void *elem = (char *)base + i * size;
if (compar(elem, mid) < 0)
++pivot_index;
}
void *pivot = (char *)base + pivot_index * size;
memcpy(temp, pivot, size);
memcpy(pivot, mid, size);
memcpy(mid, temp, size);
char *l, *r = (char *)base + (nmemb-1) * size;
for (l = base; l < r;) {
if (compar(l, pivot) > 0) {
// swap l and r
memcpy(temp, l, size);
memcpy(l, r, size);
memcpy(r, temp, size);
r -= size;
} else {
// l is already in the right place
l += size;
}
}
qsort(base, pivot_index, size, compar);
qsort((char *)pivot + size, nmemb - 1 - pivot_index, size, compar);
free(temp);
}
int abs(int x) {
return x >= 0 ? x : -x;
}
long labs(long x) {
return x >= 0 ? x : -x;
}
div_t div(int numer, int denom) {
div_t d;
d.quot = numer / denom;
d.rem = numer % denom;
return d;
}
ldiv_t ldiv(long numer, long denom) {
ldiv_t d;
d.quot = numer / denom;
d.rem = numer % denom;
return d;
}
#endif // _STDLIB_H