61 lines
1.9 KiB
Diff
61 lines
1.9 KiB
Diff
Based on https://gcc.gnu.org/ml/gcc-patches/2015-06/txtLtaPOCTgpq.txt
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Support for deterministic builds with externally defined
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values for the macros __DATE__, __TIME__ and __DATETIME__.
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If the environment variable SOURCE_DATE_EPOCH is defined,
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use its value instead of the time(2) return value as
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seconds since the Epoch.
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Use strtoll() to convert SOURCE_DATE_EPOCH just in case
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time_t is some day promoted to a 64 bit value.
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--- libcpp/macro.c
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+++ libcpp/macro.c
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@@ -356,14 +356,38 @@ _cpp_builtin_macro_text (cpp_reader *pfile, cpp_hashnode *node)
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slow on some systems. */
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time_t tt;
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struct tm *tb = NULL;
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+ char *source_date_epoch;
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- /* (time_t) -1 is a legitimate value for "number of seconds
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- since the Epoch", so we have to do a little dance to
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- distinguish that from a genuine error. */
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- errno = 0;
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- tt = time(NULL);
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- if (tt != (time_t)-1 || errno == 0)
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- tb = localtime (&tt);
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+ /* Allow the date and time to be set externally by an exported
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+ environment variable to enable reproducible builds. */
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+ source_date_epoch = getenv ("SOURCE_DATE_EPOCH");
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+ if (source_date_epoch)
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+ {
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+ errno = 0;
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+ tt = (time_t) strtoll (source_date_epoch, NULL, 10);
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+ if (errno == 0)
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+ {
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+ tb = gmtime (&tt);
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+ if (tb == NULL)
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+ cpp_error (pfile, CPP_DL_ERROR,
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+ "SOURCE_DATE_EPOCH=\"%s\" is not a valid date",
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+ source_date_epoch);
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+ }
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+ else
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+ cpp_error (pfile, CPP_DL_ERROR,
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+ "SOURCE_DATE_EPOCH=\"%s\" is not a valid number",
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+ source_date_epoch);
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+ }
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+ else
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+ {
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+ /* (time_t) -1 is a legitimate value for "number of seconds
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+ since the Epoch", so we have to do a little dance to
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+ distinguish that from a genuine error. */
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+ errno = 0;
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+ tt = time(NULL);
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+ if (tt != (time_t)-1 || errno == 0)
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+ tb = localtime (&tt);
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+ }
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if (tb)
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{
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