Package: gcc-5 Version: 5.3.1-17 Severity: normal Tags: upstream patch Control: clone -1 -2 Control: reassign -2 gcc-6 6.1.1-1
Hi, With the SOURCE_DATE_EPOCH patch from upstream, the __DATE__ and __TIME__ macros always give Jan 1 1970 00:00:00 when running the preprocessor on its own with gcc -E[1]. I believe this is because c_lex_with_flags is not called when just preprocessing (no C code needs to be lexed), so pfile->source_date_epoch stays initialised to 0, and subsequent __DATE__/__TIME__ expansions believe that the timestamp has been set to epoch 0. I have attached an alternative implementation of gcc-SOURCE_DATE_EPOCH.diff which fixes this, by initialising pfile->source_date_epoch inside libcpp when pfile is initially created. [1] https://paste.debian.net/683081/ -- System Information: Debian Release: stretch/sid APT prefers unstable-debug APT policy: (500, 'unstable-debug'), (500, 'unstable'), (1, 'experimental-debug'), (1, 'experimental') Architecture: amd64 (x86_64) Kernel: Linux 4.5.0-2-amd64 (SMP w/4 CPU cores) Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8) Shell: /bin/sh linked to /bin/dash Init: systemd (via /run/systemd/system) Versions of packages gcc-5 depends on: ii binutils 2.26-8 ii cpp-5 5.3.1-17 ii gcc-5-base 5.3.1-17 ii libc6 2.22-7 ii libcc1-0 6.1.1-1 ii libgcc-5-dev 5.3.1-17 ii libgcc1 1:6.1.1-1 ii libgmp10 2:6.1.0+dfsg-2 ii libisl15 0.16.1-1 ii libmpc3 1.0.3-1 ii libmpfr4 3.1.4-1 ii libstdc++6 6.1.1-1 ii zlib1g 1:1.2.8.dfsg-2+b1 Versions of packages gcc-5 recommends: ii libc6-dev 2.22-7 Versions of packages gcc-5 suggests: pn gcc-5-doc <none> pn gcc-5-locales <none> pn gcc-5-multilib <none> pn libasan2-dbg <none> pn libatomic1-dbg <none> pn libcilkrts5-dbg <none> pn libgcc1-dbg <none> pn libgomp1-dbg <none> pn libitm1-dbg <none> pn liblsan0-dbg <none> pn libmpx0-dbg <none> pn libquadmath0-dbg <none> pn libtsan0-dbg <none> pn libubsan0-dbg <none> -- no debconf information
--- a/src/libcpp/init.c
+++ b/src/libcpp/init.c
@@ -36,6 +36,7 @@
static void init_library (void);
static void mark_named_operators (cpp_reader *, int);
+static void cpp_init_source_date_epoch (cpp_reader *);
static void read_original_filename (cpp_reader *);
static void read_original_directory (cpp_reader *);
static void post_options (cpp_reader *);
@@ -264,6 +265,9 @@
_cpp_init_hashtable (pfile, table);
+ /* Initialize the source_date_epoch value. */
+ cpp_init_source_date_epoch (pfile);
+
return pfile;
}
@@ -530,6 +534,46 @@
_cpp_define_builtin (pfile, "__OBJC__ 1");
}
+/* Read SOURCE_DATE_EPOCH from environment to have a deterministic
+ timestamp to replace embedded current dates to get reproducible
+ results. Returns -1 if SOURCE_DATE_EPOCH is not defined. */
+static time_t
+get_source_date_epoch (cpp_reader *pfile)
+{
+ char *source_date_epoch;
+ long long epoch;
+ char *endptr;
+
+ source_date_epoch = getenv ("SOURCE_DATE_EPOCH");
+ if (!source_date_epoch)
+ return (time_t) -1;
+
+ errno = 0;
+ epoch = strtoll (source_date_epoch, &endptr, 10);
+ if ((errno == ERANGE && (epoch == LLONG_MAX || epoch == LLONG_MIN))
+ || (errno != 0 && epoch == 0))
+ cpp_error (pfile, CPP_DL_FATAL, "environment variable $SOURCE_DATE_EPOCH: "
+ "strtoll: %s\n", xstrerror(errno));
+ if (endptr == source_date_epoch)
+ cpp_error (pfile, CPP_DL_FATAL, "environment variable $SOURCE_DATE_EPOCH: "
+ "no digits were found: %s\n", endptr);
+ if (*endptr != '\0')
+ cpp_error (pfile, CPP_DL_FATAL, "environment variable $SOURCE_DATE_EPOCH: "
+ "trailing garbage: %s\n", endptr);
+ if (epoch < 0)
+ cpp_error (pfile, CPP_DL_FATAL, "environment variable $SOURCE_DATE_EPOCH: "
+ "value must be nonnegative: %lld \n", epoch);
+
+ return (time_t) epoch;
+}
+
+/* Initialize the source_date_epoch value. */
+static void
+cpp_init_source_date_epoch (cpp_reader *pfile)
+{
+ pfile->source_date_epoch = get_source_date_epoch (pfile);
+}
+
/* Sanity-checks are dependent on command-line options, so it is
called as a subroutine of cpp_read_main_file (). */
#if ENABLE_CHECKING
--- a/src/libcpp/internal.h
+++ b/src/libcpp/internal.h
@@ -502,6 +502,10 @@
const unsigned char *date;
const unsigned char *time;
+ /* Externally set timestamp to replace current date and time useful for
+ reproducibility. */
+ time_t source_date_epoch;
+
/* EOF token, and a token forcing paste avoidance. */
cpp_token avoid_paste;
cpp_token eof;
--- a/src/libcpp/macro.c
+++ b/src/libcpp/macro.c
@@ -350,13 +350,20 @@
time_t tt;
struct tm *tb = NULL;
- /* (time_t) -1 is a legitimate value for "number of seconds
- since the Epoch", so we have to do a little dance to
- distinguish that from a genuine error. */
- errno = 0;
- tt = time(NULL);
- if (tt != (time_t)-1 || errno == 0)
- tb = localtime (&tt);
+ /* Set a reproducible timestamp for __DATE__ and __TIME__ macro
+ usage if SOURCE_DATE_EPOCH is defined. */
+ if (pfile->source_date_epoch != (time_t) -1)
+ tb = gmtime (&pfile->source_date_epoch);
+ else
+ {
+ /* (time_t) -1 is a legitimate value for "number of seconds
+ since the Epoch", so we have to do a little dance to
+ distinguish that from a genuine error. */
+ errno = 0;
+ tt = time (NULL);
+ if (tt != (time_t)-1 || errno == 0)
+ tb = localtime (&tt);
+ }
if (tb)
{
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