Hash :
30784c47
Author :
Date :
2017-04-22T02:11:26
parse-datetime: overflow and debug cleanups This long patch was triggered by this bug report from Ruediger Meier: http://lists.gnu.org/archive/html/bug-gnulib/2017-04/msg00028.html I fixed the bug he noted, then found some others nearby, and then still others. Oh my goodness, there were a lot of bugs. I cleaned up some of the code to follow GNU standards while I was at it. * lib/parse-datetime.y (ISDIGIT): Remove; all callers changed to use c_isdigit. (EPOCH_YEAR): Remove; unused. (TM_YEAR_BASE): Now an enum rather than a macro. (HOUR, debug_strfdatetime): Multiply hour by 3600, not 60, to get time zone offset, since timezones now are in terms of seconds and not minutes. (long_time_t): Remove. All uses replaced by time_t or intmax_t as appropriate. Verify that intmax_t is wide enough. (time_overflow, time_zone_str): New functions, used to deal more reliably with overflow. (dbg_printf): Add printf attribute, to help catch integer width errors. (textint, relative_time, parser_control, time_zone_hhmm, set_hhmmss) (%union, to_hour, yylex, parse_datetime2): Use intmax_t instead of long int and/or long_time_t. All uses changed. (DBGBUFSIZE): Move earlier. (relative_time, set_hhmmss, parser_control): Just use int for nanoseconds and for time zones; that’s wide enough. (parser_control): Use bool for members like year_seen that can be booleans instead of counters. All uses changed. Remove debug_default_input_timezone; no longer needed. All uses removed. (apply_relative_time): Return a bool overflow flag. All uses changed to check for overflow. (apply_relative_time, zone, date, relunit, relunit_snumber) (signed_seconds, unsigned_seconds, yylex, parse_datetime2): Check for integer overflow portably. (str_days): Use just int for N, as it’s wide enough. Prefer 2D char arrays to arrays of char * when it looks like 2D is a win on typical platforms. Prefer snprintf to strncpy/strncat, for simplicity; all buffers are smaller than INT_MAX so this is safe. (TIME_ZONE_BUFSiZE, TM_YEAR_BUFSIZE): New constants. (debug_print_current_time): Don’t assume tv_nsec is of type long, as this is not true on x32. Output "." before any nanoseconds. (debug_print_current_time, parse_datetime2): Output local zones using a more-consistent format. (debug_print_current_time, date, parse_datetime2): (main) [TEST]: Don’t assume time_t is the same width as long. (print_rel_part): New function, replacing ... (PRINT_REL_PART): ... this macro, which was removed. All uses changed. (debug_print_relative_time): Use bool for boolean. (local_zone): dsts_seen now counts only tDST instances. (date): Fix printf of size_t to use %z. Do not assume numeric tokens have negative values merely because the context suggests a syntax with "-" separating tokens. (time_zone_hhmm): Return bool success indicator, which checks for overflow. Store result into PC->time_zone instead. All callers changed. (tm_year_str): New function. Return a bool success indicator and store the result into a buffer. All callers changed. Output the numerically correct string even if adding 1900 to the year would overflow. (to_tm_year): New function, replacing the old to_year. All callers changed. (tm_diff): Sync with glibc. (lookup_word): Use to_uchar instead of doing it by hand. (TZBUFSIZE): Now local to the only function that needs it. (debug_strfdatetime): Simplify now that time zones are int seconds. (debug_strfdate): Work even if tm_year + 1900 would overflow. (get_effective_timezone): Remove. All uses removed. (parse_datetime2): Use fprintf in pieces instead of snprintfing to a fixed-size buffer. Don’t assume that gmtime succeeds iff localtime succeeds. Use tm_gmtoff if available. Simplify how ‘goto fail;’ works in conjunction with the ‘ok’ flag. * m4/parse-datetime.m4 (gl_PARSE_DATETIME): Don’t define TIME_T_FITS_IN_LONG_INT, as it is no longer needed. * modules/parse-datetime (Depends-on): Add inttypes.
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Description:
Convert a date/time string to linear time.
Files:
doc/parse-datetime.texi
lib/parse-datetime.h
lib/parse-datetime.y
m4/bison.m4
m4/tm_gmtoff.m4
m4/parse-datetime.m4
Depends-on:
c-ctype
stdbool
gettime
gettext-h
intprops
inttypes
mktime
setenv
strftime
unsetenv
time
time_r
time_rz
timegm
verify
configure.ac:
gl_PARSE_DATETIME
Makefile.am:
# This rule overrides the Automake generated .y.c rule, to ensure that the
# parse-datetime.c file gets generated in the source directory, not in the
# build directory.
parse-datetime.c: parse-datetime.y
$(AM_V_GEN)$(SHELL) $(YLWRAP) $(srcdir)/parse-datetime.y \
y.tab.c parse-datetime.c \
y.tab.h parse-datetime.h \
y.output parse-datetime.output \
-- $(YACC) $(YFLAGS) $(AM_YFLAGS) && \
sed -e 's|".*/parse-datetime.y"|"parse-datetime.y"|' \
< parse-datetime.c > parse-datetime.c-t && \
rm -f parse-datetime.c && \
mv parse-datetime.c-t $(srcdir)/parse-datetime.c
lib_SOURCES += parse-datetime.y
BUILT_SOURCES += parse-datetime.c
MOSTLYCLEANFILES += parse-datetime.c-t
MAINTAINERCLEANFILES += parse-datetime.c
EXTRA_DIST += parse-datetime.c
Include:
"parse-datetime.h"
License:
LGPLv2+
Maintainer:
Paul Eggert