diff options
Diffstat (limited to '05')
| -rw-r--r-- | 05/main.c | 25 | ||||
| -rw-r--r-- | 05/stdc_common.h | 65 | ||||
| -rw-r--r-- | 05/stdio.h | 7 | ||||
| -rw-r--r-- | 05/stdlib.h | 174 |
4 files changed, 261 insertions, 10 deletions
@@ -2,9 +2,32 @@ #include <math.h> #include <stdio.h> #include <signal.h> +#include <stdlib.h> + + +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) { - raise(SIGKILL); + 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; } diff --git a/05/stdc_common.h b/05/stdc_common.h index 10144a8..a3a8e7f 100644 --- a/05/stdc_common.h +++ b/05/stdc_common.h @@ -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 ยง 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)); } @@ -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 diff --git a/05/stdlib.h b/05/stdlib.h index e98156b..c2f83eb 100644 --- a/05/stdlib.h +++ b/05/stdlib.h @@ -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 |