the last parts of the C standard library

This commit is contained in:
pommicket 2022-02-16 22:58:16 -05:00
parent b1e837afb4
commit 6e1158f49a
8 changed files with 361 additions and 32 deletions

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@ -2352,20 +2352,26 @@ function generate_push_expression
p = expr + 4
expr = generate_push_expression(statement, expr)
p = types + *4p
if *2p == TYPE2_FUNCTION_POINTER goto deref_function_pointer
p += 1
if *1p == TYPE_FUNCTION goto deref_do_nothing ; dereferencing a function pointer does nothing
if *1p == TYPE_ARRAY goto deref_do_nothing ; dereferencing a pointer to array does nothing
generate_stack_dereference(statement, type)
:deref_function_pointer ; dereferencing a function pointer does NOTHING
:deref_do_nothing
return expr
:generate_subscript
expr += 8
c = expr + 4 ; type 1
c = *4c
p = c + 1
expr = generate_push_expression(statement, expr)
d = expr + 4 ; type 2
d = *4d
expr = generate_push_expression(statement, expr)
generate_stack_add(statement, c, d, c)
p = type_is_array(p)
if p != 0 goto subscript_is_array
generate_stack_dereference(statement, type)
:subscript_is_array
return expr
:generate_dot_or_arrow
; @NONSTANDARD: we require that the 1st operand to . be an lvalue

6
05/errno.h Normal file
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@ -0,0 +1,6 @@
#ifndef _ERRNO_H
#define _ERRNO_H
#include <stdc_common.h> // we define all the relevant things here
#endif // _ERRNO_H

34
05/float.h Normal file
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@ -0,0 +1,34 @@
#ifndef _FLOAT_H
#define _FLOAT_H
#define DBL_DIG 15
#define DBL_EPSILON 2.2204460492503131e-16
#define DBL_MANT_DIG 53
#define DBL_MAX 1.7976931348623157e+308
#define DBL_MAX_10_EXP 308
#define DBL_MAX_EXP 1024
#define DBL_MIN 2.2250738585072027e-308
#define DBL_MIN_10_EXP (-307)
#define DBL_MIN_EXP (-1021)
#define FLT_DIG 6
#define FLT_EPSILON 1.19209290e-07
#define FLT_MANT_DIG 24
#define FLT_MAX 3.40282347e+38
#define FLT_MAX_10_EXP +38
#define FLT_MAX_EXP 128
#define FLT_MIN 1.17549435e-38
#define FLT_MIN_10_EXP (-37)
#define FLT_MIN_EXP (-125)
#define FLT_RADIX 2
#define FLT_ROUNDS 1
#define LDBL_DIG DBL_DIG
#define LDBL_EPSILON DBL_EPSILON
#define LDBL_MANT_DIG DBL_MANT_DIG
#define LDBL_MAX DBL_MAX
#define LDBL_MAX_10_EXP DBL_MAX_10_EXP
#define LDBL_MAX_EXP DBL_MAX_EXP
#define LDBL_MIN DBL_MIN
#define LDBL_MIN_10_EXP DBL_MIN_10_EXP
#define LDBL_MIN_EXP DBL_MIN_EXP
#endif // _FLOAT_H

6
05/limits.h Normal file
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@ -0,0 +1,6 @@
#ifndef _LIMITS_H
#define _LIMITS_H
#include <stdc_common.h> // we define all the relevant constants here
#endif // _LIMITS_H

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@ -4,30 +4,12 @@
#include <signal.h>
#include <stdlib.h>
#include <string.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;
}
#include <time.h>
#include <float.h>
int main(int argc, char **argv) {
char buf[36];
strcpy(buf, "Hello there there!");
/* buf[36]='b'; */
printf("%s\n",strstr(buf," ther"));
static char str[] = "?a???b,,,#c";
char *t;
printf("%s\n", strtok(str, "?")); /* t points to the token "a" */
printf("%s\n", strtok(NULL, ","));
printf("%s\n", strtok(NULL, "#,"));
printf("%s\n", strtok(NULL, "?"));
srand(time(NULL));
printf("%d\n",rand());
return 0;
}

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@ -1740,6 +1740,8 @@ int rename(const char *old, const char *new) {
char *tmpnam(char *s) {
struct timespec t = {0};
do {
// NB: we can't use rand() here because
// "The implementation shall behave as if no library function calls the rand function." C89 § 4.10.2.1
clock_gettime(CLOCK_MONOTONIC, &t); // use clock as a source of randomness
sprintf(s, "/tmp/C_%06u", t.tv_nsec % 1000000);
} while (access(s, F_OK) == 0); // if file exists, generate a new name

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@ -163,21 +163,21 @@ char *strstr(const char *s1, const char *s2) {
return NULL;
}
char *_strtok_str;
char *strtok(char *s1, const char *s2) {
if (s1) _strtok_str = s1;
if (!_strtok_str) return NULL;
char *p = _strtok_str + strspn(_strtok_str, s2);
static char *str;
if (s1) str = s1;
if (!str) return NULL;
char *p = str + strspn(str, s2);
if (!*p) {
_strtok_str = NULL;
str = NULL;
return NULL;
}
char *q = strpbrk(p, s2);
if (q) {
*q = 0;
_strtok_str = q + 1;
str = q + 1;
} else {
_strtok_str = NULL;
str = NULL;
}
return p;
}

293
05/time.h Normal file
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@ -0,0 +1,293 @@
#ifndef _TIME_H
#define _TIME_H
#include <stdc_common.h>
#define CLK_TCK 1000000000 // doesnt matter; clock() will always fail.
typedef long clock_t;
clock_t clock(void) {
// "If the processor time used is not available or its value cannot be represented, the function returns the value (clock_t)-1." C89 § 4.12.2.1
return -1;
}
double difftime(time_t time1, time_t time0) {
return (double)(time1 - time0);
}
time_t time(time_t *timer) {
struct timespec ts = {0};
if (clock_gettime(CLOCK_REALTIME, &ts) != 0) return -1;
if (timer) *timer = ts.tv_sec;
return ts.tv_sec;
}
// @NONSTANDARD(except in UTC+0): we don't support local time in timezones other than UTC+0.
struct tm {
int tm_sec; /* seconds after the minute --- [0, 60] */
int tm_min; /* minutes after the hour --- [0, 59] */
int tm_hour; /* hours since midnight --- [0, 23] */
int tm_mday; /* day of the month --- [1, 31] */
int tm_mon; /* months since January --- [0, 11] */
int tm_year; /* years since 1900 */
int tm_wday; /* days since Sunday --- [0, 6] */
int tm_yday; /* days since January 1 --- [0, 365] */
int tm_isdst; /* Daylight Saving Time flag */
};
void _gmtime_r(const time_t *timer, struct tm *tm) {
time_t t = *timer;
int year = 1970;
int days = t / 86400;
int leap_year;
int month;
tm->tm_isdst = 0;
tm->tm_wday = (4 + days) % 7; // jan 1 1970 was a thursday
while (1) {
leap_year = year % 4 == 0 && (year % 100 != 0 || year % 400 == 0);
int ydays = leap_year ? 366 : 365;
if (days < ydays) break;
days -= ydays;
++year;
}
tm->tm_year = year - 1900;
tm->tm_yday = days;
for (month = 0; month < 12; ++month) {
int mdays;
switch (month) {
case 0: case 2: case 4: case 6: case 7: case 9: case 11:
mdays = 31;
break;
case 3: case 5: case 8: case 10:
mdays = 30;
break;
case 1:
mdays = 28 + leap_year;
break;
}
if (days < mdays) break;
days -= mdays;
}
tm->tm_mday = days + 1;
tm->tm_mon = month;
t %= 86400;
tm->tm_hour = t / 3600;
t %= 3600;
tm->tm_min = t / 60;
tm->tm_sec = t % 60;
}
time_t mktime(struct tm *tm) {
// @NONSTANDARD-ish.
// not implementing this -- note that the implementation has to support tm_* values
// outside of their proper ranges.
return (time_t)-1;
}
struct tm *gmtime(const time_t *timer) {
static struct tm result;
_gmtime_r(timer, &result);
return &result;
}
struct tm *localtime(const time_t *timer) {
static struct tm result;
_gmtime_r(timer, &result);
return &result;
}
static const char _wday_name[7][4] = {
"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
};
static const char _weekday_name[7][16] = {
"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"
};
static const char _mon_name[12][4] = {
"Jan", "Feb", "Mar", "Apr", "May", "Jun",
"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
};
static const char _month_name[12][16] = {
"January", "February", "March", "April", "May", "June",
"July", "August", "September", "October", "November", "December"
};
char *asctime(const struct tm *timeptr) {
// lifted from the (draft of the) C standard
static char result[32];
sprintf(result, "%.3s %.3s%3d %.2d:%.2d:%.2d %d\n",
_wday_name[timeptr->tm_wday],
_mon_name[timeptr->tm_mon],
timeptr->tm_mday, timeptr->tm_hour,
timeptr->tm_min, timeptr->tm_sec,
1900 + timeptr->tm_year);
return result;
}
char *ctime(const time_t *timer) {
return asctime(localtime(timer));
}
size_t strftime(char *s, size_t maxsize, const char *format, const struct tm *tm) {
size_t n = 0, l;
char *name;
while (*format) {
if (*format == '%') {
++format;
int c = *format++;
switch (c) {
case 'a':
if (n+4 >= maxsize) return 0;
strcpy(s, _wday_name[tm->tm_wday]);
s += 3;
n += 3;
break;
case 'A':
name = _weekday_name[tm->tm_wday];
l = strlen(name);
if (n+l+1 >= maxsize) return 0;
strcpy(s, name);
s += l;
n += l;
break;
case 'b':
if (n+4 >= maxsize) return 0;
strcpy(s, _mon_name[tm->tm_mon]);
s += 3;
n += 3;
break;
case 'B':
name = _month_name[tm->tm_mon];
l = strlen(name);
if (n+l+1 >= maxsize) return 0;
strcpy(s, name);
s += l;
n += l;
break;
case 'c':
if (n+32 >= maxsize) return 0;
sprintf(s, "%s %02d %s %d %02d:%02d:%02d %s UTC",
_wday_name[tm->tm_wday], tm->tm_mday, _mon_name[tm->tm_mon],
1900+tm->tm_year, (tm->tm_hour + 11) % 12 + 1, tm->tm_min, tm->tm_sec,
tm->tm_hour >= 12 ? "PM" : "AM");
s += 31;
n += 31;
break;
case 'd':
if (n+3 >= maxsize) return 0;
sprintf(s, "%02d", tm->tm_mday);
s += 2;
n += 2;
break;
case 'H':
if (n+3 >= maxsize) return 0;
sprintf(s, "%02d", tm->tm_hour);
s += 2;
n += 2;
break;
case 'I':
if (n+3 >= maxsize) return 0;
sprintf(s, "%02d", (tm->tm_hour + 11) % 12 + 1);
s += 2;
n += 2;
break;
case 'j':
if (n+4 >= maxsize) return 0;
sprintf(s, "%03d", tm->tm_yday + 1);
s += 3;
n += 3;
break;
case 'm':
if (n+3 >= maxsize) return 0;
sprintf(s, "%02d", tm->tm_mon + 1);
s += 2;
n += 2;
break;
case 'M':
if (n+3 >= maxsize) return 0;
sprintf(s, "%02d", tm->tm_min);
s += 2;
n += 2;
break;
case 'p':
if (n+3 >= maxsize) return 0;
sprintf(s, "%s", tm->tm_hour >= 12 ? "PM" : "AM");
s += 2;
n += 2;
break;
case 'S':
if (n+3 >= maxsize) return 0;
sprintf(s, "%02d", tm->tm_sec);
s += 2;
n += 2;
break;
case 'w':
if (n+2 >= maxsize) return 0;
sprintf(s, "%d", tm->tm_wday);
s += 1;
n += 1;
break;
case 'x':
if (n+16 >= maxsize) return 0;
sprintf(s, "%s %02d %s %d",
_wday_name[tm->tm_wday], tm->tm_mday, _mon_name[tm->tm_mon],
1900+tm->tm_year);
s += 15;
n += 15;
break;
case 'X':
if (n+16 >= maxsize) return 0;
sprintf(s, "%02d:%02d:%02d %s UTC",
(tm->tm_hour + 11) % 12 + 1, tm->tm_min, tm->tm_sec,
tm->tm_hour >= 12 ? "PM" : "AM");
s += 15;
n += 15;
break;
case 'y':
if (n+3 >= maxsize) return 0;
sprintf(s, "%02d", tm->tm_year % 100);
s += 2;
n += 2;
break;
case 'Y':
if (n+5 >= maxsize) return 0;
sprintf(s, "%d", tm->tm_year + 1900);
s += 4;
n += 4;
break;
case 'Z':
if (n+4 >= maxsize) return 0;
strcpy(s, "UTC");
s += 3;
n += 3;
break;
case '%':
if (n >= maxsize) return 0;
*s++ = '%';
n += 1;
break;
case 'U': // WEEK NUMBER OF THE YEAR? WHO GIVES A SHIT?
case 'W': // WEEK NUMBER OF THE YEAR MONDAY-BASED EDITION. IF YOU DIDNT ALREADY GET ENOUGH WEEK NUMBERS. FUCK YOU
default:
fprintf(stderr, "Bad strftime format.\n");
abort();
}
} else {
if (n >= maxsize) return 0;
*s++ = *format++;
n += 1;
}
}
if (n >= maxsize) return 0;
*s = 0;
#undef _Push_str
return n;
}
#endif // _TIME_H