gcc/c-family/ChangeLog:

2016-04-28  Eduard Sanou  <dhole@openmailbox.org>
	    Matthias Klose  <doko@debian.org>

	* c-common.c (get_source_date_epoch): New function, gets the environment
	variable SOURCE_DATE_EPOCH and parses it as long long with error 
	handling.
	* c-common.h (get_source_date_epoch): Prototype.
	* c-lex.c (c_lex_with_flags): set parse_in->source_date_epoch.

gcc/ChangeLog:

2016-04-28  Eduard Sanou  <dhole@openmailbox.org>
	    Matthias Klose  <doko@debian.org>

	* doc/cppenv.texi: Document SOURCE_DATE_EPOCH environment variable.

libcpp/ChangeLog:

2016-04-28  Eduard Sanou  <dhole@openmailbox.org>
	    Matthias Klose  <doko@debian.org>

	* include/cpplib.h (cpp_init_source_date_epoch): Prototype.
	* init.c (cpp_init_source_date_epoch): New function.
	* internal.h: Added source_date_epoch variable to struct
	cpp_reader to store a reproducible date.
	* macro.c (_cpp_builtin_macro_text): Set pfile->date timestamp from 
	pfile->source_date_epoch instead of localtime if source_date_epoch is 
	set, to be used for __DATE__ and __TIME__ macros to help reproducible 
	builds.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@235550 138bc75d-0d04-0410-961f-82ee72b054a4

5 files changed, 41 insertions, 8 deletions

diff --git a/libcpp/ChangeLog b/libcpp/ChangeLog
index acb8d75dccf..1dc1c73bff2 100644
--- a/libcpp/ChangeLog
+++ b/libcpp/ChangeLog
@@ -1,3 +1,15 @@
+2016-04-28  Eduard Sanou  <dhole@openmailbox.org>
+	    Matthias Klose  <doko@debian.org>
+
+	* include/cpplib.h (cpp_init_source_date_epoch): Prototype.
+	* init.c (cpp_init_source_date_epoch): New function.
+	* internal.h: Added source_date_epoch variable to struct
+	cpp_reader to store a reproducible date.
+	* macro.c (_cpp_builtin_macro_text): Set pfile->date timestamp from 
+	pfile->source_date_epoch instead of localtime if source_date_epoch is 
+	set, to be used for __DATE__ and __TIME__ macros to help reproducible 
+	builds.
+
 2016-04-13  Bernd Schmidt  <bschmidt@redhat.com>
 
 	Patch from Roger Orr <rogero@howzatt.demon.co.uk>
diff --git a/libcpp/include/cpplib.h b/libcpp/include/cpplib.h
index 35b0375c09c..4998b3a8ab8 100644
--- a/libcpp/include/cpplib.h
+++ b/libcpp/include/cpplib.h
@@ -784,6 +784,9 @@ extern void cpp_init_special_builtins (cpp_reader *);
 /* Set up built-ins like __FILE__.  */
 extern void cpp_init_builtins (cpp_reader *, int);
 
+/* Initialize the source_date_epoch value.  */
+extern void cpp_init_source_date_epoch (cpp_reader *, time_t);
+
 /* This is called after options have been parsed, and partially
    processed.  */
 extern void cpp_post_options (cpp_reader *);
diff --git a/libcpp/init.c b/libcpp/init.c
index 4343075ba85..f5ff85b3bae 100644
--- a/libcpp/init.c
+++ b/libcpp/init.c
@@ -533,8 +533,15 @@ cpp_init_builtins (cpp_reader *pfile, int hosted)
     _cpp_define_builtin (pfile, "__OBJC__ 1");
 }
 
+/* Initialize the source_date_epoch value.  */
+void
+cpp_init_source_date_epoch (cpp_reader *pfile, time_t source_date_epoch)
+{
+  pfile->source_date_epoch = source_date_epoch; 
+}
+
 /* Sanity-checks are dependent on command-line options, so it is
-   called as a subroutine of cpp_read_main_file ().  */
+   called as a subroutine of cpp_read_main_file.  */
 #if CHECKING_P
 static void sanity_checks (cpp_reader *);
 static void sanity_checks (cpp_reader *pfile)
diff --git a/libcpp/internal.h b/libcpp/internal.h
index 9ce870738cc..e3eb26b1f27 100644
--- a/libcpp/internal.h
+++ b/libcpp/internal.h
@@ -502,6 +502,10 @@ struct cpp_reader
   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;
diff --git a/libcpp/macro.c b/libcpp/macro.c
index c2515534504..c2a83764660 100644
--- a/libcpp/macro.c
+++ b/libcpp/macro.c
@@ -357,13 +357,20 @@ _cpp_builtin_macro_text (cpp_reader *pfile, cpp_hashnode *node,
 	  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)
 	    {