2013-11-05 Tobias Burnus <burnus@net-b.de>

gcc/c-family/
        * c.opt (-Wdate-time): New option
        * c-opts.c (sanitize_cpp_opts): Pass on to libcpp.

gcc/
        * doc/invoke.texi (-Wdate-time): Document.

gcc/fortran
        * lang.opt (-Wdate-time): New option
        * cpp.c (gfc_cpp_option_data): Add warn_date_time.
        (gfc_cpp_init_options, gfc_cpp_handle_option,
        gfc_cpp_post_options): Handle it and pass on to libcpp.

gcc/testsuite/
        * g++.dg/warn/wdate-time.C: New.
        * gcc.dg/wdate-time.c: New.
        * gfortran.dg/wdate-time.F90: New.

libcpp/
        * include/cpplib.h (CPP_W_DATE_TIME): Added.
        (cpp_options): Add warn_date_time.
        * init.c (cpp_create_reader): Init it.
        * macro.c (_cpp_builtin_macro_text): Warn when
        __DATE__/__TIME__/__TIMESTAMP__ is used.




git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@204420 138bc75d-0d04-0410-961f-82ee72b054a4

4 files changed, 22 insertions, 2 deletions

diff --git a/libcpp/ChangeLog b/libcpp/ChangeLog
index 2e98e34887e..670affd90e7 100644
--- a/libcpp/ChangeLog
+++ b/libcpp/ChangeLog
@@ -1,6 +1,14 @@
+2013-11-05  Tobias Burnus  <burnus@net-b.de>
+
+	* include/cpplib.h (CPP_W_DATE_TIME): Added.
+	(cpp_options): Add warn_date_time.
+	* init.c (cpp_create_reader): Init it.
+	* macro.c (_cpp_builtin_macro_text): Warn when
+	__DATE__/__TIME__/__TIMESTAMP__ is used.
+
 2013-10-31  Edward Smith-Rowland  <3dw4rd@verizon.net>
 
-        Implement C++14 digit separators.
+	Implement C++14 digit separators.
 	* include/cpplib.h (cpp_options): Add digit_separators flag.
 	* internal.h (DIGIT_SEP(c)): New macro.
 	* expr.c (cpp_classify_number): Check improper placement of digit sep;
diff --git a/libcpp/include/cpplib.h b/libcpp/include/cpplib.h
index 34ad6c30c8e..02927d4c6cb 100644
--- a/libcpp/include/cpplib.h
+++ b/libcpp/include/cpplib.h
@@ -337,6 +337,9 @@ struct cpp_options
   /* Nonzero means warn if slash-star appears in a comment.  */
   unsigned char warn_comments;
 
+  /* Nonzero means to warn about __DATA__, __TIME__ and __TIMESTAMP__ usage.   */
+  unsigned char warn_date_time;
+
   /* Nonzero means warn if a user-supplied include directory does not
      exist.  */
   unsigned char warn_missing_include_dirs;
@@ -925,7 +928,8 @@ enum {
   CPP_W_NORMALIZE,
   CPP_W_INVALID_PCH,
   CPP_W_WARNING_DIRECTIVE,
-  CPP_W_LITERAL_SUFFIX
+  CPP_W_LITERAL_SUFFIX,
+  CPP_W_DATE_TIME
 };
 
 /* Output a diagnostic of some kind.  */
diff --git a/libcpp/init.c b/libcpp/init.c
index 97aa6cdd45f..67444301590 100644
--- a/libcpp/init.c
+++ b/libcpp/init.c
@@ -193,6 +193,7 @@ cpp_create_reader (enum c_lang lang, cpp_hash_table *table,
   CPP_OPTION (pfile, canonical_system_headers)
       = ENABLE_CANONICAL_SYSTEM_HEADERS;
   CPP_OPTION (pfile, ext_numeric_literals) = 1;
+  CPP_OPTION (pfile, warn_date_time) = 0;
 
   /* Default CPP arithmetic to something sensible for the host for the
      benefit of dumb users like fix-header.  */
diff --git a/libcpp/macro.c b/libcpp/macro.c
index 6d46027e4ea..3a1728d6663 100644
--- a/libcpp/macro.c
+++ b/libcpp/macro.c
@@ -232,6 +232,10 @@ _cpp_builtin_macro_text (cpp_reader *pfile, cpp_hashnode *node)
 
     case BT_TIMESTAMP:
       {
+	if (CPP_OPTION (pfile, warn_date_time))
+	  cpp_warning (pfile, CPP_W_DATE_TIME, "Macro \"%s\" might prevent "
+		       "reproduce builds", NODE_NAME (node));
+
 	cpp_buffer *pbuffer = cpp_get_buffer (pfile);
 	if (pbuffer->timestamp == NULL)
 	  {
@@ -325,6 +329,9 @@ _cpp_builtin_macro_text (cpp_reader *pfile, cpp_hashnode *node)
 
     case BT_DATE:
     case BT_TIME:
+      if (CPP_OPTION (pfile, warn_date_time))
+	cpp_warning (pfile, CPP_W_DATE_TIME, "Macro \"%s\" might prevent "
+		     "reproduce builds", NODE_NAME (node));
       if (pfile->date == NULL)
 	{
 	  /* Allocate __DATE__ and __TIME__ strings from permanent