>From ba220ef16734eb45e246ff10523423e39603e168 Mon Sep 17 00:00:00 2001 From: Colin Watson Date: Sun, 9 Jul 2023 02:04:58 +0100 Subject: [PATCH] Display time from SOURCE_DATE_EPOCH in UTC. The semantics imposed in 1.23.0 are unsuitable for use with reproducible-builds harnesses, since those specifically want to vary the TZ environment variable to shake out other problems in build systems. However, my patch that Debian has been carrying for a while is unsuitable for general use, since most people expect the time displayed in output to use local time. A viable compromise seems to be to force UTC _only_ when SOURCE_DATE_EPOCH is set. That will keep reproducible-builds harnesses working with no extra effort, while also preserving the expected behaviour for typical users of groff that don't go out of their way to set that environment variable. As a bonus, this corrects the behaviour of gropdf when the local offset from UTC is not a whole number of hours. * src/include/curtime.h (current_time): Return a `struct tm *`. Document behaviour. * src/libs/libgroff/curtime.cpp (current_time): If SOURCE_DATE_EPOCH is set, return the overridden time after passing it through `gmtime`. Otherwise, pass the current time through `localtime`. * src/devices/grohtml/post-html.cpp (html_printer::do_file_components, html_printer::~html_printer): * src/devices/grops/ps.cpp (ps_printer::~ps_printer): * src/roff/troff/input.cpp (init_registers): Adjust to new `current_time` signature. * src/devices/gropdf/gropdf.pl: If SOURCE_DATE_EPOCH is set, return the overridden time after passing it through `gmtime`. Otherwise, pass the current time through `localtime`. (PDFDate): Fix output in the case where the local offset from UTC is not a whole number of hours. (Previously, the minutes offset field was always set to zero.) * src/devices/grohtml/grohtml.1.man (Environment): * src/devices/gropdf/gropdf.1.man (Environment): * src/devices/grops/grops.1.man (Environment): * src/roff/groff/groff.1.man (Environment): * src/roff/troff/troff.1.man (Environment): Update. * NEWS: Document this. --- NEWS | 17 +++++++++++++++++ src/devices/grohtml/grohtml.1.man | 12 +++++++----- src/devices/grohtml/post-html.cpp | 16 ++++------------ src/devices/gropdf/gropdf.1.man | 10 +++++----- src/devices/gropdf/gropdf.pl | 16 ++++++++++++++-- src/devices/grops/grops.1.man | 12 +++++++----- src/devices/grops/ps.cpp | 9 ++------- src/include/curtime.h | 19 +++++++++++-------- src/libs/libgroff/curtime.cpp | 23 +++++++++++++---------- src/roff/groff/groff.1.man | 12 +++++++----- src/roff/troff/input.cpp | 24 +++++++++--------------- src/roff/troff/troff.1.man | 12 +++++++----- 12 files changed, 103 insertions(+), 79 deletions(-) diff --git a/NEWS b/NEWS index 85b034be3..6b8e0cd36 100644 --- a/NEWS +++ b/NEWS @@ -7,6 +7,23 @@ This file describes recent user-visible changes in groff. Bug fixes are not described. There are more details in the man and info pages. +VERSION 1.23.1 +============== + +Miscellaneous +------------- + +o If groff programs have their current time overridden by the SOURCE_DATE_EPOCH + environment variable, then that time is always displayed in UTC. That + environment variable is normally only set when specifically requesting build + systems to produce reproducible output, and it is useful for reproducibility + test harnesses to vary the TZ environment variable and ensure that it does + not affect the output of the build; those harnesses have no way to set TZ=UTC + only for groff programs. People setting SOURCE_DATE_EPOCH are likely to be + more in the "system programmer" camp as described in the release notes for + 1.23.0, so it is easier to defend time-zone-invariant output to them. In all + other cases, the current time remains displayed in local time. + VERSION 1.23.0 ============== diff --git a/src/devices/grohtml/grohtml.1.man b/src/devices/grohtml/grohtml.1.man index 2243b474c..8a55c93dd 100644 --- a/src/devices/grohtml/grohtml.1.man +++ b/src/devices/grohtml/grohtml.1.man @@ -616,18 +616,20 @@ A timestamp to use as the output creation timestamp in place of the current time. . The time is converted to human-readable form using -.MR ctime 3 +.MR gmtime 3 +and +.MR asctime 3 , and recorded in an HTML comment. . . .TP .I TZ -The time zone to use when converting the current time -(or value of -.IR SOURCE_DATE_EPOCH ) -to human-readable form; +The time zone to use when converting the current time to human-readable form; see .MR tzset 3 . +If +.I SOURCE_DATE_EPOCH +is used, it is always converted to human-readable form using UTC. . . .\" ==================================================================== diff --git a/src/devices/grohtml/post-html.cpp b/src/devices/grohtml/post-html.cpp index 4e02b5cfa..b42720da1 100644 --- a/src/devices/grohtml/post-html.cpp +++ b/src/devices/grohtml/post-html.cpp @@ -5081,11 +5081,7 @@ void html_printer::do_file_components (void) fclose(file_list.get_file()); file_list.move_next(); if (file_list.is_new_output_file()) { -#ifdef LONG_FOR_TIME_T - long t; -#else - time_t t; -#endif + struct tm *t; if (fragment_no > 1) write_navigation(top, prev, next, current); @@ -5115,7 +5111,7 @@ void html_printer::do_file_components (void) if (do_write_date_comment) { t = current_time(); html.begin_comment("CreationDate: ") - .put_string(ctime(&t), strlen(ctime(&t))-1) + .put_string(asctime(t), strlen(asctime(t))-1) .end_comment(); } @@ -5215,11 +5211,7 @@ void html_printer::writeHeadMetaStyle (void) html_printer::~html_printer() { -#ifdef LONG_FOR_TIME_T - long t; -#else - time_t t; -#endif + struct tm *t; if (current_paragraph) current_paragraph->flush_text(); @@ -5240,7 +5232,7 @@ html_printer::~html_printer() if (do_write_date_comment) { t = current_time(); html.begin_comment("CreationDate: ") - .put_string(ctime(&t), strlen(ctime(&t))-1) + .put_string(asctime(t), strlen(asctime(t))-1) .end_comment(); } diff --git a/src/devices/gropdf/gropdf.1.man b/src/devices/gropdf/gropdf.1.man index d1d39bbe0..20a957e68 100644 --- a/src/devices/gropdf/gropdf.1.man +++ b/src/devices/gropdf/gropdf.1.man @@ -1673,18 +1673,18 @@ A timestamp to use as the output creation timestamp in place of the current time. . The time is converted to human-readable form using Perl's -.I \%localtime() +.I \%gmtime() function and recorded in a PDF comment. . . .TP .I TZ -The time zone to use when converting the current time -(or value of -.IR SOURCE_DATE_EPOCH ) -to human-readable form; +The time zone to use when converting the current time to human-readable form; see .MR tzset 3 . +If +.I SOURCE_DATE_EPOCH +is used, it is always converted to human-readable form using UTC. . . .\" ==================================================================== diff --git a/src/devices/gropdf/gropdf.pl b/src/devices/gropdf/gropdf.pl index c65a1051f..0e1b612a5 100644 --- a/src/devices/gropdf/gropdf.pl +++ b/src/devices/gropdf/gropdf.pl @@ -23,6 +23,7 @@ use strict; use warnings; use Getopt::Long qw(:config bundling); +use POSIX qw(mktime); use constant { @@ -343,7 +344,12 @@ for $papersz ( split(" ", lc($possiblesizes).' #duff#') ) # If we get here, $papersz was invalid, so try the next one. } -my (@dt)=localtime($ENV{SOURCE_DATE_EPOCH} || time); +my @dt; +if ($ENV{SOURCE_DATE_EPOCH}) { + @dt=gmtime($ENV{SOURCE_DATE_EPOCH}); +} else { + @dt=localtime; +} my $dt=PDFDate(\@dt); my %info=('Creator' => "(groff version $cfg{GROFF_VERSION})", @@ -628,7 +634,13 @@ sub GetObj sub PDFDate { my $dt=shift; - return(sprintf("D:%04d%02d%02d%02d%02d%02d%+03d'00'",$dt->[5]+1900,$dt->[4]+1,$dt->[3],$dt->[2],$dt->[1],$dt->[0],( localtime time() + 3600*( 12 - (gmtime)[2] ) )[2] - 12)); + my $offset; + if ($ENV{SOURCE_DATE_EPOCH}) { + $offset=0; + } else { + $offset=mktime((localtime $dt)[0..5]) - mktime((gmtime $dt)[0..5]); + } + return(sprintf("D:%04d%02d%02d%02d%02d%02d%+03d'%+03d'",$dt->[5]+1900,$dt->[4]+1,$dt->[3],$dt->[2],$dt->[1],$dt->[0],int($offset/3600),int(($offset%3600)/60))); } sub ToPoints diff --git a/src/devices/grops/grops.1.man b/src/devices/grops/grops.1.man index d0ec21d0b..53014ee1b 100644 --- a/src/devices/grops/grops.1.man +++ b/src/devices/grops/grops.1.man @@ -1696,18 +1696,20 @@ A timestamp to use as the output creation timestamp in place of the current time. . The time is converted to human-readable form using -.MR ctime 3 +.MR gmtime 3 +and +.MR asctime 3 , and recorded in a PostScript comment. . . .TP .I TZ -The time zone to use when converting the current time -(or value of -.IR SOURCE_DATE_EPOCH ) -to human-readable form; +The time zone to use when converting the current time to human-readable form; see .MR tzset 3 . +If +.I SOURCE_DATE_EPOCH +is used, it is always converted to human-readable form using UTC. . . .\" ==================================================================== diff --git a/src/devices/grops/ps.cpp b/src/devices/grops/ps.cpp index 807945f97..59e6e253d 100644 --- a/src/devices/grops/ps.cpp +++ b/src/devices/grops/ps.cpp @@ -1390,13 +1390,8 @@ ps_printer::~ps_printer() .end_comment(); { fputs("%%CreationDate: ", out.get_file()); -#ifdef LONG_FOR_TIME_T - long -#else - time_t -#endif - t = current_time(); - fputs(ctime(&t), out.get_file()); + struct tm *t = current_time(); + fputs(asctime(t), out.get_file()); } for (font_pointer_list *f = font_list; f; f = f->next) { ps_font *psf = (ps_font *)(f->p); diff --git a/src/include/curtime.h b/src/include/curtime.h index 5d3a24a7b..ebd2efb80 100644 --- a/src/include/curtime.h +++ b/src/include/curtime.h @@ -15,13 +15,16 @@ for more details. The GNU General Public License version 2 (GPL2) is available in the internet at . */ -#ifndef LONG_FOR_TIME_T #include -#endif -#ifdef LONG_FOR_TIME_T -long -#else -time_t -#endif -current_time(); +// Get the current time in broken-down time representation. If the +// SOURCE_DATE_EPOCH environment variable is set, then it is used instead of +// the real time from the system clock; in this case, the user is clearly +// trying to arrange for some kind of reproducible build, so express the +// time in UTC. Otherwise, use the real time from the system clock, and +// express it relative to the user's time zone. +// +// In either case, as with gmtime() and localtime(), the return value points +// to a statically-allocated struct which might be overwritten by later +// calls. +struct tm *current_time(); diff --git a/src/libs/libgroff/curtime.cpp b/src/libs/libgroff/curtime.cpp index 34dbc5ca9..277755cab 100644 --- a/src/libs/libgroff/curtime.cpp +++ b/src/libs/libgroff/curtime.cpp @@ -15,9 +15,7 @@ for more details. The GNU General Public License version 2 (GPL2) is available in the internet at . */ -#ifdef HAVE_CONFIG_H -#include -#endif +#include "lib.h" #include #include @@ -25,16 +23,18 @@ internet at . */ #include #include +#include "curtime.h" #include "errarg.h" #include "error.h" +struct tm *current_time() +{ #ifdef LONG_FOR_TIME_T -long + long #else -time_t + time_t #endif -current_time() -{ + t; char *source_date_epoch = getenv("SOURCE_DATE_EPOCH"); if (source_date_epoch) { @@ -49,7 +49,10 @@ current_time() fatal("$SOURCE_DATE_EPOCH: no digits found: '%1'", endptr); if (*endptr != '\0') fatal("$SOURCE_DATE_EPOCH: trailing garbage: '%1'", endptr); - return epoch; - } else - return time(0); + t = epoch; + return gmtime(&t); + } else { + t = time(0); + return localtime(&t); + } } diff --git a/src/roff/groff/groff.1.man b/src/roff/groff/groff.1.man index c551326e8..754857c26 100644 --- a/src/roff/groff/groff.1.man +++ b/src/roff/groff/groff.1.man @@ -1876,19 +1876,21 @@ A time stamp to use as the output creation time stamp in place of the current time. . The time is converted to human-readable form using -.MR localtime 3 +.MR gmtime 3 +and +.MR asctime 3 when the formatter starts up and stored in registers usable by documents and macro packages. . . .TP .I TZ -The time zone to use when converting the current time -(or value of -.IR SOURCE_DATE_EPOCH ) -to human-readable form; +The time zone to use when converting the current time to human-readable form; see .MR tzset 3 . +If +.I SOURCE_DATE_EPOCH +is used, it is always converted to human-readable form using UTC. . . .\" ==================================================================== diff --git a/src/roff/troff/input.cpp b/src/roff/troff/input.cpp index 292ee7389..f03338335 100644 --- a/src/roff/troff/input.cpp +++ b/src/roff/troff/input.cpp @@ -8297,21 +8297,15 @@ void warn_request() static void init_registers() { -#ifdef LONG_FOR_TIME_T - long -#else /* not LONG_FOR_TIME_T */ - time_t -#endif /* not LONG_FOR_TIME_T */ - t = current_time(); - struct tm *tt = localtime(&t); - set_number_reg("seconds", int(tt->tm_sec)); - set_number_reg("minutes", int(tt->tm_min)); - set_number_reg("hours", int(tt->tm_hour)); - set_number_reg("dw", int(tt->tm_wday + 1)); - set_number_reg("dy", int(tt->tm_mday)); - set_number_reg("mo", int(tt->tm_mon + 1)); - set_number_reg("year", int(1900 + tt->tm_year)); - set_number_reg("yr", int(tt->tm_year)); + struct tm *t = current_time(); + set_number_reg("seconds", int(t->tm_sec)); + set_number_reg("minutes", int(t->tm_min)); + set_number_reg("hours", int(t->tm_hour)); + set_number_reg("dw", int(t->tm_wday + 1)); + set_number_reg("dy", int(t->tm_mday)); + set_number_reg("mo", int(t->tm_mon + 1)); + set_number_reg("year", int(1900 + t->tm_year)); + set_number_reg("yr", int(t->tm_year)); set_number_reg("$$", getpid()); register_dictionary.define(".A", new readonly_text_register(ascii_output_flag diff --git a/src/roff/troff/troff.1.man b/src/roff/troff/troff.1.man index d83c4a515..17c5713af 100644 --- a/src/roff/troff/troff.1.man +++ b/src/roff/troff/troff.1.man @@ -865,19 +865,21 @@ A timestamp to use as the output creation timestamp in place of the current time. . The time is converted to human-readable form using -.MR localtime 3 +.MR gmtime 3 +and +.MR asctime 3 when the formatter starts up and stored in registers usable by documents and macro packages. . . .TP .I TZ -The timezone to use when converting the current time -(or value of -.IR SOURCE_DATE_EPOCH ) -to human-readable form; +The time zone to use when converting the current time to human-readable form; see .MR tzset 3 . +If +.I SOURCE_DATE_EPOCH +is used, it is always converted to human-readable form using UTC. . . .\" ==================================================================== -- 2.39.2