bug-gnulib
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[bug-gnulib] strftime.c fixes imported from coreutils


From: Paul Eggert
Subject: [bug-gnulib] strftime.c fixes imported from coreutils
Date: Wed, 09 Mar 2005 10:41:12 -0800
User-agent: Gnus/5.1006 (Gnus v5.10.6) Emacs/21.4 (gnu/linux)

I installed this fix to strftime.c, imported from coreutils.
Eventually I plan to migrate this into libc.

2005-03-09  Paul Eggert  <address@hidden>

        * strftime.c: Include <stdbool.h>.  Use bool where appropriate,
        instead of int.
        (my_strftime): Do not mishandle years close to INT_MAX, by doing
        the right thing even if adding 1900 would overflow.  Similarly
        for tm_mon + 1 and tm_yday + 1.
        Make %Y always equivalent to %C%y, and similarly for %G and %g.
        (DO_NUMBER, DO_NUMBER_SPACEPAD): Set digits to d, not a conditional.
        (DO_SIGNED_NUMBER): New macro.
        (my_strftime) [HAVE_TZNAME]: Don't dump core if tp->tm_dst > 1.

--- strftime.c  11 Nov 2004 05:58:12 -0000      1.76
+++ strftime.c  9 Mar 2005 18:39:39 -0000       1.77
@@ -1,4 +1,4 @@
-/* Copyright (C) 1991-1999, 2000, 2001, 2003, 2004 Free Software
+/* Copyright (C) 1991-1999, 2000, 2001, 2003, 2004, 2005 Free Software
    Foundation, Inc.
 
    NOTE: The canonical source of this file is maintained with the GNU C 
Library.
@@ -72,6 +72,7 @@ extern char *tzname[];
 #endif
 
 #include <limits.h>
+#include <stdbool.h>
 #include <stddef.h>
 #include <stdlib.h>
 #include <string.h>
@@ -479,16 +480,17 @@ my_strftime (CHAR_T *s, size_t maxsize, 
       int modifier;            /* Field modifier ('E', 'O', or 0).  */
       int digits;              /* Max digits for numeric format.  */
       int number_value;                /* Numeric value to be printed.  */
-      int negative_number;     /* 1 if the number is negative.  */
+      unsigned int u_number_value; /* (unsigned int) number_value.  */
+      bool negative_number;    /* 1 if the number is negative.  */
       const CHAR_T *subfmt;
       CHAR_T *bufp;
       CHAR_T buf[1 + (sizeof (int) < sizeof (time_t)
                      ? INT_STRLEN_BOUND (time_t)
                      : INT_STRLEN_BOUND (int))];
       int width = -1;
-      int to_lowcase = 0;
-      int to_uppcase = 0;
-      int change_case = 0;
+      bool to_lowcase = false;
+      bool to_uppcase = false;
+      bool change_case = false;
       int format_char;
 
 #if DO_MULTIBYTE && !defined COMPILE_WIDE
@@ -593,10 +595,10 @@ my_strftime (CHAR_T *s, size_t maxsize, 
 
              /* This changes textual output.  */
            case L_('^'):
-             to_uppcase = 1;
+             to_uppcase = true;
              continue;
            case L_('#'):
-             change_case = 1;
+             change_case = true;
              continue;
 
            default:
@@ -643,10 +645,14 @@ my_strftime (CHAR_T *s, size_t maxsize, 
       switch (format_char)
        {
 #define DO_NUMBER(d, v) \
-         digits = d > width ? d : width;                                     \
+         digits = d;                                                         \
          number_value = v; goto do_number
+#define DO_SIGNED_NUMBER(d, negative, v) \
+         digits = d;                                                         \
+         negative_number = negative;                                         \
+         u_number_value = v; goto do_signed_number
 #define DO_NUMBER_SPACEPAD(d, v) \
-         digits = d > width ? d : width;                                     \
+         digits = d;                                                         \
          number_value = v; goto do_number_spacepad
 
        case L_('%'):
@@ -660,8 +666,8 @@ my_strftime (CHAR_T *s, size_t maxsize, 
            goto bad_format;
          if (change_case)
            {
-             to_uppcase = 1;
-             to_lowcase = 0;
+             to_uppcase = true;
+             to_lowcase = false;
            }
 #if defined _NL_CURRENT || !HAVE_STRFTIME
          cpy (aw_len, a_wkday);
@@ -675,8 +681,8 @@ my_strftime (CHAR_T *s, size_t maxsize, 
            goto bad_format;
          if (change_case)
            {
-             to_uppcase = 1;
-             to_lowcase = 0;
+             to_uppcase = true;
+             to_lowcase = false;
            }
 #if defined _NL_CURRENT || !HAVE_STRFTIME
          cpy (STRLEN (f_wkday), f_wkday);
@@ -689,8 +695,8 @@ my_strftime (CHAR_T *s, size_t maxsize, 
        case L_('h'):
          if (change_case)
            {
-             to_uppcase = 1;
-             to_lowcase = 0;
+             to_uppcase = true;
+             to_lowcase = false;
            }
          if (modifier != 0)
            goto bad_format;
@@ -706,8 +712,8 @@ my_strftime (CHAR_T *s, size_t maxsize, 
            goto bad_format;
          if (change_case)
            {
-             to_uppcase = 1;
-             to_lowcase = 0;
+             to_uppcase = true;
+             to_lowcase = false;
            }
 #if defined _NL_CURRENT || !HAVE_STRFTIME
          cpy (STRLEN (f_month), f_month);
@@ -807,8 +813,9 @@ my_strftime (CHAR_T *s, size_t maxsize, 
            }
 
          {
-           int year = tp->tm_year + TM_YEAR_BASE;
-           DO_NUMBER (1, year / 100 - (year % 100 < 0));
+           int century = tp->tm_year / 100 + TM_YEAR_BASE / 100;
+           century -= tp->tm_year % 100 < 0 && 0 < century;
+           DO_SIGNED_NUMBER (2, tp->tm_year < - TM_YEAR_BASE, century);
          }
 
        case L_('x'):
@@ -846,8 +853,8 @@ my_strftime (CHAR_T *s, size_t maxsize, 
 
          DO_NUMBER_SPACEPAD (2, tp->tm_mday);
 
-         /* All numeric formats set DIGITS and NUMBER_VALUE and then
-            jump to one of these two labels.  */
+         /* All numeric formats set DIGITS and NUMBER_VALUE (or U_NUMBER_VALUE)
+            and then jump to one of these three labels.  */
 
        do_number_spacepad:
          /* Force `_' flag unless overridden by `0' or `-' flag.  */
@@ -855,14 +862,22 @@ my_strftime (CHAR_T *s, size_t maxsize, 
            pad = L_('_');
 
        do_number:
-         /* Format the number according to the MODIFIER flag.  */
-
-         if (modifier == L_('O') && 0 <= number_value)
+         /* Format NUMBER_VALUE according to the MODIFIER flag.  */
+         negative_number = number_value < 0;
+         u_number_value = number_value;
+
+       do_signed_number:
+         /* Format U_NUMBER_VALUE according to the MODIFIER flag.
+            NEGATIVE_NUMBER is nonzero if the original number was
+            negative; in this case it was converted directly to
+            unsigned int (i.e., modulo (UINT_MAX + 1)) without
+            negating it.  */
+         if (modifier == L_('O') && !negative_number)
            {
 #ifdef _NL_CURRENT
              /* Get the locale specific alternate representation of
-                the number NUMBER_VALUE.  If none exist NULL is returned.  */
-             const CHAR_T *cp = nl_get_alt_digit (number_value
+                the number.  If none exist NULL is returned.  */
+             const CHAR_T *cp = nl_get_alt_digit (u_number_value
                                                   HELPER_LOCALE_ARG);
 
              if (cp != NULL)
@@ -880,19 +895,21 @@ my_strftime (CHAR_T *s, size_t maxsize, 
 # endif
 #endif
            }
-         {
-           unsigned int u = number_value;
 
-           bufp = buf + sizeof (buf) / sizeof (buf[0]);
-           negative_number = number_value < 0;
+         bufp = buf + sizeof (buf) / sizeof (buf[0]);
 
-           if (negative_number)
-             u = -u;
+         if (negative_number)
+           u_number_value = - u_number_value;
 
-           do
-             *--bufp = u % 10 + L_('0');
-           while ((u /= 10) != 0);
-         }
+         do
+           {
+             *--bufp = u_number_value % 10 + L_('0');
+             u_number_value /= 10;
+           }
+         while (u_number_value != 0);
+
+         if (digits < width)
+           digits = width;
 
        do_number_sign_and_padding:
          if (negative_number)
@@ -974,7 +991,7 @@ my_strftime (CHAR_T *s, size_t maxsize, 
          if (modifier == L_('E'))
            goto bad_format;
 
-         DO_NUMBER (3, 1 + tp->tm_yday);
+         DO_SIGNED_NUMBER (3, tp->tm_yday < -1, tp->tm_yday + 1U);
 
        case L_('M'):
          if (modifier == L_('E'))
@@ -986,7 +1003,7 @@ my_strftime (CHAR_T *s, size_t maxsize, 
          if (modifier == L_('E'))
            goto bad_format;
 
-         DO_NUMBER (2, tp->tm_mon + 1);
+         DO_SIGNED_NUMBER (2, tp->tm_mon < -1, tp->tm_mon + 1U);
 
 #ifndef _LIBC
        case L_('N'):           /* GNU extension.  */
@@ -1010,7 +1027,7 @@ my_strftime (CHAR_T *s, size_t maxsize, 
          break;
 
        case L_('P'):
-         to_lowcase = 1;
+         to_lowcase = true;
 #if !defined _NL_CURRENT && HAVE_STRFTIME
          format_char = L_('p');
 #endif
@@ -1019,8 +1036,8 @@ my_strftime (CHAR_T *s, size_t maxsize, 
        case L_('p'):
          if (change_case)
            {
-             to_uppcase = 0;
-             to_lowcase = 1;
+             to_uppcase = false;
+             to_lowcase = true;
            }
 #if defined _NL_CURRENT || !HAVE_STRFTIME
          cpy (ap_len, ampm);
@@ -1070,20 +1087,7 @@ my_strftime (CHAR_T *s, size_t maxsize, 
              {
                int d = t % 10;
                t /= 10;
-
-               if (negative_number)
-                 {
-                   d = -d;
-
-                   /* Adjust if division truncates to minus infinity.  */
-                   if (0 < -1 % 10 && d < 0)
-                     {
-                       t++;
-                       d += 10;
-                     }
-                 }
-
-               *--bufp = d + L_('0');
+               *--bufp = (negative_number ? -d : d) + L_('0');
              }
            while (t != 0);
 
@@ -1131,14 +1135,22 @@ my_strftime (CHAR_T *s, size_t maxsize, 
          if (modifier == L_('E'))
            goto bad_format;
          {
-           int year = tp->tm_year + TM_YEAR_BASE;
+           /* YEAR is a leap year if and only if (tp->tm_year + TM_YEAR_BASE)
+              is a leap year, except that YEAR and YEAR - 1 both work
+              correctly even when (tp->tm_year + TM_YEAR_BASE) would
+              overflow.  */
+           int year = (tp->tm_year
+                       + (tp->tm_year < 0
+                          ? TM_YEAR_BASE % 400
+                          : TM_YEAR_BASE % 400 - 400));
+           int year_adjust = 0;
            int days = iso_week_days (tp->tm_yday, tp->tm_wday);
 
            if (days < 0)
              {
                /* This ISO week belongs to the previous year.  */
-               year--;
-               days = iso_week_days (tp->tm_yday + (365 + __isleap (year)),
+               year_adjust = -1;
+               days = iso_week_days (tp->tm_yday + (365 + __isleap (year - 1)),
                                      tp->tm_wday);
              }
            else
@@ -1148,7 +1160,7 @@ my_strftime (CHAR_T *s, size_t maxsize, 
                if (0 <= d)
                  {
                    /* This ISO week belongs to the next year.  */
-                   year++;
+                   year_adjust = 1;
                    days = d;
                  }
              }
@@ -1156,10 +1168,19 @@ my_strftime (CHAR_T *s, size_t maxsize, 
            switch (*f)
              {
              case L_('g'):
-               DO_NUMBER (2, (year % 100 + 100) % 100);
+               {
+                 int yy = (tp->tm_year % 100 + year_adjust) % 100;
+                 DO_NUMBER (2, (0 <= yy
+                                ? yy
+                                : tp->tm_year < -TM_YEAR_BASE - year_adjust
+                                ? -yy
+                                : yy + 100));
+               }
 
              case L_('G'):
-               DO_NUMBER (1, year);
+               DO_SIGNED_NUMBER (4, tp->tm_year < -TM_YEAR_BASE - year_adjust,
+                                 (tp->tm_year + (unsigned int) TM_YEAR_BASE
+                                  + year_adjust));
 
              default:
                DO_NUMBER (2, days / 7 + 1);
@@ -1201,7 +1222,8 @@ my_strftime (CHAR_T *s, size_t maxsize, 
          if (modifier == L_('O'))
            goto bad_format;
          else
-           DO_NUMBER (1, tp->tm_year + TM_YEAR_BASE);
+           DO_SIGNED_NUMBER (4, tp->tm_year < -TM_YEAR_BASE,
+                             tp->tm_year + (unsigned int) TM_YEAR_BASE);
 
        case L_('y'):
          if (modifier == L_('E'))
@@ -1220,19 +1242,25 @@ my_strftime (CHAR_T *s, size_t maxsize, 
 # endif
 #endif
            }
-         DO_NUMBER (2, (tp->tm_year % 100 + 100) % 100);
+
+         {
+           int yy = tp->tm_year % 100;
+           if (yy < 0)
+             yy = tp->tm_year < - TM_YEAR_BASE ? -yy : yy + 100;
+           DO_NUMBER (2, yy);
+         }
 
        case L_('Z'):
          if (change_case)
            {
-             to_uppcase = 0;
-             to_lowcase = 1;
+             to_uppcase = false;
+             to_lowcase = true;
            }
 
 #if HAVE_TZNAME
          /* The tzset() call might have changed the value.  */
          if (!(zone && *zone) && tp->tm_isdst >= 0)
-           zone = tzname[tp->tm_isdst];
+           zone = tzname[tp->tm_isdst != 0];
 #endif
          if (! zone)
            zone = "";




reply via email to

[Prev in Thread] Current Thread [Next in Thread]