the last parts of the C standard library

8 files changed, 361 insertions, 32 deletions

diff --git a/05/codegen.b b/05/codegen.b
index b89ab51..46354e9 100644
--- a/05/codegen.b
+++ b/05/codegen.b
@@ -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
diff --git a/05/errno.h b/05/errno.h
new file mode 100644
index 0000000..426f351
--- /dev/null
+++ b/05/errno.h
@@ -0,0 +1,6 @@
+#ifndef _ERRNO_H
+#define _ERRNO_H
+
+#include <stdc_common.h> // we define all the relevant things here
+
+#endif // _ERRNO_H
diff --git a/05/float.h b/05/float.h
new file mode 100644
index 0000000..6ae607d
--- /dev/null
+++ b/05/float.h
@@ -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
diff --git a/05/limits.h b/05/limits.h
new file mode 100644
index 0000000..633e9ff
--- /dev/null
+++ b/05/limits.h
@@ -0,0 +1,6 @@
+#ifndef _LIMITS_H
+#define _LIMITS_H
+
+#include <stdc_common.h> // we define all the relevant constants here
+
+#endif // _LIMITS_H
diff --git a/05/main.c b/05/main.c
index 2dc7b81..0c991b7 100644
--- a/05/main.c
+++ b/05/main.c
@@ -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;
 }
 
diff --git a/05/stdio.h b/05/stdio.h
index e5a04cc..e474fca 100644
--- a/05/stdio.h
+++ b/05/stdio.h
@@ -1739,7 +1739,9 @@ int rename(const char *old, const char *new) {
 
 char *tmpnam(char *s) {
 	struct timespec t = {0};
-	do {		
+	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
diff --git a/05/string.h b/05/string.h
index 02216b5..4b73101 100644
--- a/05/string.h
+++ b/05/string.h
@@ -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;
 }
diff --git a/05/time.h b/05/time.h
new file mode 100644
index 0000000..8207156
--- /dev/null
+++ b/05/time.h
@@ -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