gnu/packages/patches/gcc-6-source-date-epoch-1.patch

   1 Make GCC respect SOURCE_DATE_EPOCH in __DATE__ and __TIME__ macros.
   2
   3 Cherry-picked from upstream commit:
   4
   5 https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=e3e8c48c4a494d9da741c1c8ea6c4c0b7c4ff934
   6
   7 diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c
   8 index 6cf8c610b4e..b5daea65ba7 100644
   9 --- a/gcc/c-family/c-common.c
  10 +++ b/gcc/c-family/c-common.c
  11 @@ -12750,4 +12750,37 @@ valid_array_size_p (location_t loc, tree type, tree name)
  12    return true;
  13  }
  14
  15 +/* Read SOURCE_DATE_EPOCH from environment to have a deterministic
  16 +   timestamp to replace embedded current dates to get reproducible
  17 +   results.  Returns -1 if SOURCE_DATE_EPOCH is not defined.  */
  18 +time_t
  19 +get_source_date_epoch ()
  20 +{
  21 +  char *source_date_epoch;
  22 +  long long epoch;
  23 +  char *endptr;
  24 +
  25 +  source_date_epoch = getenv ("SOURCE_DATE_EPOCH");
  26 +  if (!source_date_epoch)
  27 +    return (time_t) -1;
  28 +
  29 +  errno = 0;
  30 +  epoch = strtoll (source_date_epoch, &endptr, 10);
  31 +  if ((errno == ERANGE && (epoch == LLONG_MAX || epoch == LLONG_MIN))
  32 +      || (errno != 0 && epoch == 0))
  33 +    fatal_error (UNKNOWN_LOCATION, "environment variable $SOURCE_DATE_EPOCH: "
  34 +                "strtoll: %s\n", xstrerror(errno));
  35 +  if (endptr == source_date_epoch)
  36 +    fatal_error (UNKNOWN_LOCATION, "environment variable $SOURCE_DATE_EPOCH: "
  37 +                "no digits were found: %s\n", endptr);
  38 +  if (*endptr != '\0')
  39 +    fatal_error (UNKNOWN_LOCATION, "environment variable $SOURCE_DATE_EPOCH: "
  40 +                "trailing garbage: %s\n", endptr);
  41 +  if (epoch < 0)
  42 +    fatal_error (UNKNOWN_LOCATION, "environment variable $SOURCE_DATE_EPOCH: "
  43 +                "value must be nonnegative: %lld \n", epoch);
  44 +
  45 +  return (time_t) epoch;
  46 +}
  47 +
  48  #include "gt-c-family-c-common.h"
  49 diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
  50 index dd74d0dd62e..c6e0ed12b55 100644
  51 --- a/gcc/c-family/c-common.h
  52 +++ b/gcc/c-family/c-common.h
  53 @@ -1467,4 +1467,9 @@ extern bool reject_gcc_builtin (const_tree, location_t = UNKNOWN_LOCATION);
  54  extern void warn_duplicated_cond_add_or_warn (location_t, tree, vec<tree> **);
  55  extern bool valid_array_size_p (location_t, tree, tree);
  56
  57 +/* Read SOURCE_DATE_EPOCH from environment to have a deterministic
  58 +   timestamp to replace embedded current dates to get reproducible
  59 +   results.  Returns -1 if SOURCE_DATE_EPOCH is not defined.  */
  60 +extern time_t get_source_date_epoch (void);
  61 +
  62  #endif /* ! GCC_C_COMMON_H */
  63 diff --git a/gcc/c-family/c-lex.c b/gcc/c-family/c-lex.c
  64 index 96da4fc974e..bf1db6c0252 100644
  65 --- a/gcc/c-family/c-lex.c
  66 +++ b/gcc/c-family/c-lex.c
  67 @@ -385,6 +385,9 @@ c_lex_with_flags (tree *value, location_t *loc, unsigned char *cpp_flags,
  68    enum cpp_ttype type;
  69    unsigned char add_flags = 0;
  70    enum overflow_type overflow = OT_NONE;
  71 +  time_t source_date_epoch = get_source_date_epoch ();
  72 +
  73 +  cpp_init_source_date_epoch (parse_in, source_date_epoch);
  74
  75    timevar_push (TV_CPP);
  76   retry:
  77 diff --git a/gcc/doc/cppenv.texi b/gcc/doc/cppenv.texi
  78 index 22c8cb37624..e958e93e97e 100644
  79 --- a/gcc/doc/cppenv.texi
  80 +++ b/gcc/doc/cppenv.texi
  81 @@ -79,4 +79,21 @@ main input file is omitted.
  82  @ifclear cppmanual
  83  @xref{Preprocessor Options}.
  84  @end ifclear
  85 +
  86 +@item SOURCE_DATE_EPOCH
  87 +
  88 +If this variable is set, its value specifies a UNIX timestamp to be
  89 +used in replacement of the current date and time in the @code{__DATE__}
  90 +and @code{__TIME__} macros, so that the embedded timestamps become
  91 +reproducible.
  92 +
  93 +The value of @env{SOURCE_DATE_EPOCH} must be a UNIX timestamp,
  94 +defined as the number of seconds (excluding leap seconds) since
  95 +01 Jan 1970 00:00:00 represented in ASCII, identical to the output of
  96 +@samp{@command{date +%s}}.
  97 +
  98 +The value should be a known timestamp such as the last modification
  99 +time of the source or package and it should be set by the build
 100 +process.
 101 +
 102  @end vtable
 103 diff --git a/libcpp/include/cpplib.h b/libcpp/include/cpplib.h
 104 index 35b0375c09c..4998b3a8ab8 100644
 105 --- a/libcpp/include/cpplib.h
 106 +++ b/libcpp/include/cpplib.h
 107 @@ -784,6 +784,9 @@ extern void cpp_init_special_builtins (cpp_reader *);
 108  /* Set up built-ins like __FILE__.  */
 109  extern void cpp_init_builtins (cpp_reader *, int);
 110
 111 +/* Initialize the source_date_epoch value.  */
 112 +extern void cpp_init_source_date_epoch (cpp_reader *, time_t);
 113 +
 114  /* This is called after options have been parsed, and partially
 115     processed.  */
 116  extern void cpp_post_options (cpp_reader *);
 117 diff --git a/libcpp/init.c b/libcpp/init.c
 118 index 4343075ba85..f5ff85b3bae 100644
 119 --- a/libcpp/init.c
 120 +++ b/libcpp/init.c
 121 @@ -533,8 +533,15 @@ cpp_init_builtins (cpp_reader *pfile, int hosted)
 122      _cpp_define_builtin (pfile, "__OBJC__ 1");
 123  }
 124
 125 +/* Initialize the source_date_epoch value.  */
 126 +void
 127 +cpp_init_source_date_epoch (cpp_reader *pfile, time_t source_date_epoch)
 128 +{
 129 +  pfile->source_date_epoch = source_date_epoch;
 130 +}
 131 +
 132  /* Sanity-checks are dependent on command-line options, so it is
 133 -   called as a subroutine of cpp_read_main_file ().  */
 134 +   called as a subroutine of cpp_read_main_file.  */
 135  #if CHECKING_P
 136  static void sanity_checks (cpp_reader *);
 137  static void sanity_checks (cpp_reader *pfile)
 138 diff --git a/libcpp/internal.h b/libcpp/internal.h
 139 index 9ce870738cc..e3eb26b1f27 100644
 140 --- a/libcpp/internal.h
 141 +++ b/libcpp/internal.h
 142 @@ -502,6 +502,10 @@ struct cpp_reader
 143    const unsigned char *date;
 144    const unsigned char *time;
 145
 146 +  /* Externally set timestamp to replace current date and time useful for
 147 +     reproducibility.  */
 148 +  time_t source_date_epoch;
 149 +
 150    /* EOF token, and a token forcing paste avoidance.  */
 151    cpp_token avoid_paste;
 152    cpp_token eof;
 153 diff --git a/libcpp/macro.c b/libcpp/macro.c
 154 index c2515534504..c2a83764660 100644
 155 --- a/libcpp/macro.c
 156 +++ b/libcpp/macro.c
 157 @@ -357,13 +357,20 @@ _cpp_builtin_macro_text (cpp_reader *pfile, cpp_hashnode *node,
 158           time_t tt;
 159           struct tm *tb = NULL;
 160
 161 -         /* (time_t) -1 is a legitimate value for "number of seconds
 162 -            since the Epoch", so we have to do a little dance to
 163 -            distinguish that from a genuine error.  */
 164 -         errno = 0;
 165 -         tt = time(NULL);
 166 -         if (tt != (time_t)-1 || errno == 0)
 167 -           tb = localtime (&tt);
 168 +         /* Set a reproducible timestamp for __DATE__ and __TIME__ macro
 169 +            usage if SOURCE_DATE_EPOCH is defined.  */
 170 +         if (pfile->source_date_epoch != (time_t) -1)
 171 +            tb = gmtime (&pfile->source_date_epoch);
 172 +         else
 173 +           {
 174 +             /* (time_t) -1 is a legitimate value for "number of seconds
 175 +                since the Epoch", so we have to do a little dance to
 176 +                distinguish that from a genuine error.  */
 177 +             errno = 0;
 178 +             tt = time (NULL);
 179 +             if (tt != (time_t)-1 || errno == 0)
 180 +               tb = localtime (&tt);
 181 +           }
 182
 183           if (tb)
 184             {
 185 --
 186 2.14.1
 187