[PATCH] Fix SOURCE_DATE_EPOCH handling with -E (PR preprocessor/71183)

[Jakub Jelinek]

Hi!

The SOURCE_DATE_EPOCH env var is ignored during -E, which is undesirable
and inconsistent.  The problem is that the appropriate callback for
libcpp is only installed when compiling and not when preprocessing only.

Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, ok for
trunk?

2016-06-13  Jakub Jelinek  <jakub@redhat.com>

	PR preprocessor/71183
	* c-ppoutput.c (init_pp_output): Set cb->get_source_date_epoch
	to cb_get_source_date_epoch.

	* gcc.dg/cpp/source_date_epoch-3.c: New test.

--- gcc/c-family/c-ppoutput.c.jj	2016-01-04 14:55:58.000000000 +0100
+++ gcc/c-family/c-ppoutput.c	2016-06-12 19:49:50.932112947 +0200
@@ -150,6 +150,7 @@ init_pp_output (FILE *out_stream)
     }
 
   cb->has_attribute = c_common_has_attribute;
+  cb->get_source_date_epoch = cb_get_source_date_epoch;
 
   /* Initialize the print structure.  */
   print.src_line = 1;
--- gcc/testsuite/gcc.dg/cpp/source_date_epoch-3.c.jj	2016-06-12 19:56:49.988696438 +0200
+++ gcc/testsuite/gcc.dg/cpp/source_date_epoch-3.c	2016-06-12 19:57:36.648093343 +0200
@@ -0,0 +1,9 @@
+/* PR preprocessor/71183 */
+/* { dg-do preprocess } */
+/* { dg-set-compiler-env-var SOURCE_DATE_EPOCH "630333296" } */
+
+const char *date = __DATE__;
+const char *time = __TIME__;
+
+/* { dg-final { scan-file source_date_epoch-3.i "Dec 22 1989" } } */
+/* { dg-final { scan-file source_date_epoch-3.i "12:34:56" } } */

	Jakub