import newlib-2000-02-17 snapshotnewlib-2000-02-17SNAPSHOT

1 files changed, 204 insertions, 0 deletions

diff --git a/newlib/libc/time/mktime.c b/newlib/libc/time/mktime.c
new file mode 100644
index 00000000000..431eca56816
--- /dev/null
+++ b/newlib/libc/time/mktime.c
@@ -0,0 +1,204 @@
+/*
+ * mktime.c
+ * Original Author:	G. Haley
+ *
+ * Converts the broken-down time, expressed as local time, in the structure
+ * pointed to by tim_p into a calendar time value. The original values of the
+ * tm_wday and tm_yday fields of the structure are ignored, and the original
+ * values of the other fields have no restrictions. On successful completion
+ * the fields of the structure are set to represent the specified calendar
+ * time. Returns the specified calendar time. If the calendar time can not be
+ * represented, returns the value (time_t) -1.
+ */
+
+/*
+FUNCTION
+<<mktime>>---convert time to arithmetic representation
+
+INDEX
+	mktime
+
+ANSI_SYNOPSIS
+	#include <time.h>
+	time_t mktime(struct tm *<[timp]>);
+
+TRAD_SYNOPSIS
+	#include <time.h>
+	time_t mktime(<[timp]>)
+	struct tm *<[timp]>;
+
+DESCRIPTION
+<<mktime>> assumes the time at <[timp]> is a local time, and converts
+its representation from the traditional representation defined by
+<<struct tm>> into a representation suitable for arithmetic.
+
+<<localtime>> is the inverse of <<mktime>>.
+
+RETURNS
+If the contents of the structure at <[timp]> do not form a valid
+calendar time representation, the result is <<-1>>.  Otherwise, the
+result is the time, converted to a <<time_t>> value.
+
+PORTABILITY
+ANSI C requires <<mktime>>.
+
+<<mktime>> requires no supporting OS subroutines.
+*/
+
+#include <stdlib.h>
+#include <time.h>
+
+#define _SEC_IN_MINUTE 60
+#define _SEC_IN_HOUR 3600
+#define _SEC_IN_DAY 86400
+
+static _CONST int DAYS_IN_MONTH[12] =
+{31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
+
+#define _DAYS_IN_MONTH(x) ((x == 1) ? days_in_feb : DAYS_IN_MONTH[x])
+
+static _CONST int _DAYS_BEFORE_MONTH[12] =
+{0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334};
+
+#define _ISLEAP(y) (((y) % 4) == 0 && (((y) % 100) != 0 || (((y)+1900) % 400) == 0))
+#define _DAYS_IN_YEAR(year) (_ISLEAP(year) ? 366 : 365)
+
+static void 
+validate_structure (tim_p)
+     struct tm *tim_p;
+{
+  div_t res;
+  int days_in_feb = 28;
+
+  /* calculate time & date to account for out of range values */
+  if (tim_p->tm_sec < 0 || tim_p->tm_sec > 59)
+    {
+      res = div (tim_p->tm_sec, 60);
+      tim_p->tm_min += res.quot;
+      if ((tim_p->tm_sec = res.rem) < 0)
+	{
+	  tim_p->tm_sec += 60;
+	  --tim_p->tm_min;
+	}
+    }
+
+  if (tim_p->tm_min < 0 || tim_p->tm_min > 59)
+    {
+      res = div (tim_p->tm_min, 60);
+      tim_p->tm_hour += res.quot;
+      if ((tim_p->tm_min = res.rem) < 0)
+	{
+	  tim_p->tm_min += 60;
+	  --tim_p->tm_hour;
+        }
+    }
+
+  if (tim_p->tm_hour < 0 || tim_p->tm_hour > 23)
+    {
+      res = div (tim_p->tm_hour, 24);
+      tim_p->tm_mday += res.quot;
+      if ((tim_p->tm_hour = res.rem) < 0)
+	{
+	  tim_p->tm_hour += 24;
+	  --tim_p->tm_mday;
+        }
+    }
+
+  if (tim_p->tm_mon > 11)
+    {
+      res = div (tim_p->tm_mon, 12);
+      tim_p->tm_year += res.quot;
+      if ((tim_p->tm_mon = res.rem) < 0)
+        {
+	  tim_p->tm_mon += 12;
+	  --tim_p->tm_year;
+        }
+    }
+
+  if (_DAYS_IN_YEAR (tim_p->tm_year) == 366)
+    days_in_feb = 29;
+
+  if (tim_p->tm_mday <= 0)
+    {
+      while (tim_p->tm_mday <= 0)
+	{
+	  if (--tim_p->tm_mon == -1)
+	    {
+	      tim_p->tm_year--;
+	      tim_p->tm_mon = 11;
+	      days_in_feb =
+		((_DAYS_IN_YEAR (tim_p->tm_year) == 366) ?
+		 29 : 28);
+	    }
+	  tim_p->tm_mday += _DAYS_IN_MONTH (tim_p->tm_mon);
+	}
+    }
+  else
+    {
+      while (tim_p->tm_mday > _DAYS_IN_MONTH (tim_p->tm_mon))
+	{
+	  tim_p->tm_mday -= _DAYS_IN_MONTH (tim_p->tm_mon);
+	  if (++tim_p->tm_mon == 12)
+	    {
+	      tim_p->tm_year++;
+	      tim_p->tm_mon = 0;
+	      days_in_feb =
+		((_DAYS_IN_YEAR (tim_p->tm_year) == 366) ?
+		 29 : 28);
+	    }
+	}
+    }
+}
+
+time_t 
+mktime (tim_p)
+     struct tm *tim_p;
+{
+  time_t tim = 0;
+  long days = 0;
+  int year;
+
+  /* validate structure */
+  validate_structure (tim_p);
+
+  /* compute hours, minutes, seconds */
+  tim += tim_p->tm_sec + (tim_p->tm_min * _SEC_IN_MINUTE) +
+    (tim_p->tm_hour * _SEC_IN_HOUR);
+
+  /* compute days in year */
+  days += tim_p->tm_mday - 1;
+  days += _DAYS_BEFORE_MONTH[tim_p->tm_mon];
+  if (tim_p->tm_mon > 1 && _DAYS_IN_YEAR (tim_p->tm_year) == 366)
+    days++;
+
+  /* compute day of the year */
+  tim_p->tm_yday = days;
+
+  if (tim_p->tm_year > 10000
+      || tim_p->tm_year < -10000)
+    {
+      return (time_t) -1;
+    }
+
+  /* compute days in other years */
+  if (tim_p->tm_year > 70)
+    {
+      for (year = 70; year < tim_p->tm_year; year++)
+	days += _DAYS_IN_YEAR (year);
+    }
+  else if (tim_p->tm_year < 70)
+    {
+      for (year = 69; year > tim_p->tm_year; year--)
+	days -= _DAYS_IN_YEAR (year);
+      days -= _DAYS_IN_YEAR (year);
+    }
+
+  /* compute day of the week */
+  if ((tim_p->tm_wday = (days + 4) % 7) < 0)
+    tim_p->tm_wday += 7;
+
+  /* compute total seconds */
+  tim += (days * _SEC_IN_DAY);
+
+  return tim;
+}