[jackhill/guix/guix.git] / gnu / packages / patches / gcc-5-source-date-epoch-2.patch

Continuation of the SOURCE_DATE_EPOCH patch.

Patch adapted from upstream source repository:

https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=dfa5c0d3f3e23e4fdb14857a42de376d9ff8601c

From dfa5c0d3f3e23e4fdb14857a42de376d9ff8601c Mon Sep 17 00:00:00 2001
From: doko <doko@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Wed, 1 Jun 2016 16:42:41 +0000
Subject: [PATCH] gcc/c-family/ChangeLog:

diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c
index 6f0898a38d7..efbc78ef218 100644
--- a/gcc/c-family/c-common.c
+++ b/gcc/c-family/c-common.c
@@ -12321,8 +12321,9 @@ pointer_to_zero_sized_aggr_p (tree t)
 /* Read SOURCE_DATE_EPOCH from environment to have a deterministic
    timestamp to replace embedded current dates to get reproducible
    results.  Returns -1 if SOURCE_DATE_EPOCH is not defined.  */
+
 time_t
-get_source_date_epoch ()
+cb_get_source_date_epoch (cpp_reader *pfile ATTRIBUTE_UNUSED)
 {
   char *source_date_epoch;
   long long epoch;
@@ -12334,19 +12335,14 @@ get_source_date_epoch ()
 
   errno = 0;
   epoch = strtoll (source_date_epoch, &endptr, 10);
-  if ((errno == ERANGE && (epoch == LLONG_MAX || epoch == LLONG_MIN))
-      || (errno != 0 && epoch == 0))
-    fatal_error (UNKNOWN_LOCATION, "environment variable $SOURCE_DATE_EPOCH: "
-		 "strtoll: %s\n", xstrerror(errno));
-  if (endptr == source_date_epoch)
-    fatal_error (UNKNOWN_LOCATION, "environment variable $SOURCE_DATE_EPOCH: "
-		 "no digits were found: %s\n", endptr);
-  if (*endptr != '\0')
-    fatal_error (UNKNOWN_LOCATION, "environment variable $SOURCE_DATE_EPOCH: "
-		 "trailing garbage: %s\n", endptr);
-  if (epoch < 0)
-    fatal_error (UNKNOWN_LOCATION, "environment variable $SOURCE_DATE_EPOCH: "
-		 "value must be nonnegative: %lld \n", epoch);
+  if (errno != 0 || endptr == source_date_epoch || *endptr != '\0'
+      || epoch < 0 || epoch > MAX_SOURCE_DATE_EPOCH)
+    {
+      error_at (input_location, "environment variable SOURCE_DATE_EPOCH must "
+	        "expand to a non-negative integer less than or equal to %wd",
+		MAX_SOURCE_DATE_EPOCH);
+      return (time_t) -1;
+    }
 
   return (time_t) epoch;
 }
diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
index ba0a5d7df50..977ae9df5ea 100644
--- a/gcc/c-family/c-common.h
+++ b/gcc/c-family/c-common.h
@@ -1063,6 +1063,16 @@ extern vec<tree, va_gc> *make_tree_vector_copy (const vec<tree, va_gc> *);
    c_register_builtin_type.  */
 extern GTY(()) tree registered_builtin_types;
 
+/* Read SOURCE_DATE_EPOCH from environment to have a deterministic
+   timestamp to replace embedded current dates to get reproducible
+   results.  Returns -1 if SOURCE_DATE_EPOCH is not defined.  */
+extern time_t cb_get_source_date_epoch (cpp_reader *pfile);
+
+/* The value (as a unix timestamp) corresponds to date
+   "Dec 31 9999 23:59:59 UTC", which is the latest date that __DATE__ and
+   __TIME__ can store.  */
+#define MAX_SOURCE_DATE_EPOCH HOST_WIDE_INT_C (253402300799)
+
 /* In c-gimplify.c  */
 extern void c_genericize (tree);
 extern int c_gimplify_expr (tree *, gimple_seq *, gimple_seq *);
@@ -1438,9 +1448,4 @@ extern tree cilk_for_number_of_iterations (tree);
 extern bool check_no_cilk (tree, const char *, const char *,
 		           location_t loc = UNKNOWN_LOCATION);
 
-/* Read SOURCE_DATE_EPOCH from environment to have a deterministic
-   timestamp to replace embedded current dates to get reproducible
-   results.  Returns -1 if SOURCE_DATE_EPOCH is not defined.  */
-extern time_t get_source_date_epoch (void);
-
 #endif /* ! GCC_C_COMMON_H */
diff --git a/gcc/c-family/c-lex.c b/gcc/c-family/c-lex.c
index e68471b9d2b..3f78073f640 100644
--- a/gcc/c-family/c-lex.c
+++ b/gcc/c-family/c-lex.c
@@ -97,6 +97,7 @@ init_c_lex (void)
   cb->valid_pch = c_common_valid_pch;
   cb->read_pch = c_common_read_pch;
   cb->has_attribute = c_common_has_attribute;
+  cb->get_source_date_epoch = cb_get_source_date_epoch;
 
   /* Set the debug callbacks if we can use them.  */
   if ((debug_info_level == DINFO_LEVEL_VERBOSE
@@ -402,9 +403,6 @@ c_lex_with_flags (tree *value, location_t *loc, unsigned char *cpp_flags,
   enum cpp_ttype type;
   unsigned char add_flags = 0;
   enum overflow_type overflow = OT_NONE;
-  time_t source_date_epoch = get_source_date_epoch ();
-
-  cpp_init_source_date_epoch (parse_in, source_date_epoch);
 
   timevar_push (TV_CPP);
  retry:
diff --git a/gcc/doc/cppenv.texi b/gcc/doc/cppenv.texi
index 3b5317beb53..7b4cf6adc11 100644
--- a/gcc/doc/cppenv.texi
+++ b/gcc/doc/cppenv.texi
@@ -81,7 +81,6 @@ main input file is omitted.
 @end ifclear
 
 @item SOURCE_DATE_EPOCH
-
 If this variable is set, its value specifies a UNIX timestamp to be
 used in replacement of the current date and time in the @code{__DATE__}
 and @code{__TIME__} macros, so that the embedded timestamps become
@@ -89,8 +88,9 @@ reproducible.
 
 The value of @env{SOURCE_DATE_EPOCH} must be a UNIX timestamp,
 defined as the number of seconds (excluding leap seconds) since
-01 Jan 1970 00:00:00 represented in ASCII, identical to the output of
-@samp{@command{date +%s}}.
+01 Jan 1970 00:00:00 represented in ASCII; identical to the output of
+@samp{@command{date +%s}} on GNU/Linux and other systems that support the
+@code{%s} extension in the @code{date} command.
 
 The value should be a known timestamp such as the last modification
 time of the source or package and it should be set by the build
diff --git a/gcc/gcc.c b/gcc/gcc.c
index d956c36b151..2709f295734 100644
--- a/gcc/gcc.c
+++ b/gcc/gcc.c
@@ -3328,6 +3328,29 @@ save_switch (const char *opt, size_t n_args, const char *const *args,
   n_switches++;
 }
 
+/* Set the SOURCE_DATE_EPOCH environment variable to the current time if it is
+   not set already.  */
+
+static void
+set_source_date_epoch_envvar ()
+{
+  /* Array size is 21 = ceil(log_10(2^64)) + 1 to hold string representations
+     of 64 bit integers.  */
+  char source_date_epoch[21];
+  time_t tt;
+
+  errno = 0;
+  tt = time (NULL);
+  if (tt < (time_t) 0 || errno != 0)
+    tt = (time_t) 0;
+
+  snprintf (source_date_epoch, 21, "%llu", (unsigned long long) tt);
+  /* Using setenv instead of xputenv because we want the variable to remain
+     after finalizing so that it's still set in the second run when using
+     -fcompare-debug.  */
+  setenv ("SOURCE_DATE_EPOCH", source_date_epoch, 0);
+}
+
 /* Handle an option DECODED that is unknown to the option-processing
    machinery.  */
 
@@ -3628,6 +3651,7 @@ driver_handle_option (struct gcc_options *opts,
       else
 	compare_debug_opt = arg;
       save_switch (compare_debug_replacement_opt, 0, NULL, validated, true);
+      set_source_date_epoch_envvar ();
       return true;
 
     case OPT_fdiagnostics_color_:
diff --git a/gcc/testsuite/gcc.dg/cpp/source_date_epoch-1.c b/gcc/testsuite/gcc.dg/cpp/source_date_epoch-1.c
new file mode 100644
index 00000000000..f6aa1a360ff
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/cpp/source_date_epoch-1.c
@@ -0,0 +1,11 @@
+/* { dg-do run } */
+/* { dg-set-compiler-env-var SOURCE_DATE_EPOCH "630333296" } */
+
+int
+main(void)
+{
+  __builtin_printf ("%s %s\n", __DATE__, __TIME__);
+  return 0;
+}
+
+/* { dg-output "^Dec 22 1989 12:34:56\n$" } */
diff --git a/gcc/testsuite/gcc.dg/cpp/source_date_epoch-2.c b/gcc/testsuite/gcc.dg/cpp/source_date_epoch-2.c
new file mode 100644
index 00000000000..ae18362ae87
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/cpp/source_date_epoch-2.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-set-compiler-env-var SOURCE_DATE_EPOCH "AAA" } */
+
+/* Make sure that SOURCE_DATE_EPOCH is only parsed once */
+
+int
+main(void)
+{
+  __builtin_printf ("%s %s\n", __DATE__, __TIME__); /* { dg-error "SOURCE_DATE_EPOCH must expand" } */
+  __builtin_printf ("%s %s\n", __DATE__, __TIME__);
+  return 0;
+}
diff --git a/gcc/testsuite/lib/gcc-dg.exp b/gcc/testsuite/lib/gcc-dg.exp
index 4fa433d9954..7656b2254a1 100644
--- a/gcc/testsuite/lib/gcc-dg.exp
+++ b/gcc/testsuite/lib/gcc-dg.exp
@@ -324,6 +324,38 @@ proc restore-target-env-var { } {
     }
 }
 
+proc dg-set-compiler-env-var { args } {
+    global set_compiler_env_var
+    global saved_compiler_env_var
+    if { [llength $args] != 3 } {
+	error "dg-set-compiler-env-var: need two arguments"
+	return
+    }
+    set var [lindex $args 1]
+    set value [lindex $args 2]
+    if [info exists ::env($var)] {
+      lappend saved_compiler_env_var [list $var 1 $::env($var)]
+    } else {
+      lappend saved_compiler_env_var [list $var 0]
+    }
+    setenv $var $value
+    lappend set_compiler_env_var [list $var $value]
+}
+
+proc restore-compiler-env-var { } {
+    global saved_compiler_env_var
+    for { set env_vari [llength $saved_compiler_env_var] } {
+          [incr env_vari -1] >= 0 } {} {
+	set env_var [lindex $saved_compiler_env_var $env_vari]
+	set var [lindex $env_var 0]
+	if [lindex $env_var 1] {
+	    setenv $var [lindex $env_var 2]
+	} else {
+	    unsetenv $var
+	}
+    }
+}
+
 # Utility routines.
 
 #
@@ -785,6 +817,11 @@ if { [info procs saved-dg-test] == [list] } {
 	if [info exists set_target_env_var] {
 	    unset set_target_env_var
 	}
+	if [info exists set_compiler_env_var] {
+	    restore-compiler-env-var
+	    unset set_compiler_env_var
+	    unset saved_compiler_env_var
+	}
 	unset_timeout_vars
 	if [info exists compiler_conditional_xfail_data] {
 	    unset compiler_conditional_xfail_data
diff --git a/libcpp/include/cpplib.h b/libcpp/include/cpplib.h
index 7a5481219be..867aeebc39f 100644
--- a/libcpp/include/cpplib.h
+++ b/libcpp/include/cpplib.h
@@ -585,6 +585,9 @@ struct cpp_callbacks
 
   /* Callback that can change a user builtin into normal macro.  */
   bool (*user_builtin_macro) (cpp_reader *, cpp_hashnode *);
+
+  /* Callback to parse SOURCE_DATE_EPOCH from environment.  */
+  time_t (*get_source_date_epoch) (cpp_reader *);
 };
 
 #ifdef VMS
@@ -775,9 +778,6 @@ 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 a8d00f4628b..61c9bbbf945 100644
--- a/libcpp/init.c
+++ b/libcpp/init.c
@@ -254,6 +254,9 @@ cpp_create_reader (enum c_lang lang, cpp_hash_table *table,
   /* Do not force token locations by default.  */
   pfile->forced_token_location_p = NULL;
 
+  /* Initialize source_date_epoch to -2 (not yet set).  */
+  pfile->source_date_epoch = (time_t) -2;
+
   /* The expression parser stack.  */
   _cpp_expand_op_stack (pfile);
 
@@ -530,13 +533,6 @@ 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 ().  */
 #if ENABLE_CHECKING
diff --git a/libcpp/internal.h b/libcpp/internal.h
index 8507eba1747..226ae328e76 100644
--- a/libcpp/internal.h
+++ b/libcpp/internal.h
@@ -503,7 +503,8 @@ struct cpp_reader
   const unsigned char *time;
 
   /* Externally set timestamp to replace current date and time useful for
-     reproducibility.  */
+     reproducibility.  It should be initialized to -2 (not yet set) and
+     set to -1 to disable it or to a non-negative value to enable it.  */
   time_t source_date_epoch;
 
   /* EOF token, and a token forcing paste avoidance.  */
diff --git a/libcpp/macro.c b/libcpp/macro.c
index 3f3b278e97d..756c7c6e0c6 100644
--- a/libcpp/macro.c
+++ b/libcpp/macro.c
@@ -351,9 +351,13 @@ _cpp_builtin_macro_text (cpp_reader *pfile, cpp_hashnode *node)
 	  struct tm *tb = NULL;
 
 	  /* 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);
+	     if SOURCE_DATE_EPOCH is defined.  */
+	  if (pfile->source_date_epoch == (time_t) -2
+	      && pfile->cb.get_source_date_epoch != NULL)
+	    pfile->source_date_epoch = pfile->cb.get_source_date_epoch (pfile);
+
+	  if (pfile->source_date_epoch >= (time_t) 0)
+	    tb = gmtime (&pfile->source_date_epoch);
 	  else
 	    {
 	      /* (time_t) -1 is a legitimate value for "number of seconds
-- 
2.11.0
Commit	Line	Data
d71d6fe8 MB	1	Continuation of the SOURCE_DATE_EPOCH patch.
	2
	3	Patch adapted from upstream source repository:
	4
	5	https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=dfa5c0d3f3e23e4fdb14857a42de376d9ff8601c
	6
	7	From dfa5c0d3f3e23e4fdb14857a42de376d9ff8601c Mon Sep 17 00:00:00 2001
	8	From: doko <doko@138bc75d-0d04-0410-961f-82ee72b054a4>
	9	Date: Wed, 1 Jun 2016 16:42:41 +0000
	10	Subject: [PATCH] gcc/c-family/ChangeLog:
	11
	12	diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c
	13	index 6f0898a38d7..efbc78ef218 100644
	14	--- a/gcc/c-family/c-common.c
	15	+++ b/gcc/c-family/c-common.c
	16	@@ -12321,8 +12321,9 @@ pointer_to_zero_sized_aggr_p (tree t)
	17	/* Read SOURCE_DATE_EPOCH from environment to have a deterministic
	18	timestamp to replace embedded current dates to get reproducible
	19	results. Returns -1 if SOURCE_DATE_EPOCH is not defined. */
	20	+
	21	time_t
	22	-get_source_date_epoch ()
	23	+cb_get_source_date_epoch (cpp_reader *pfile ATTRIBUTE_UNUSED)
	24	{
	25	char *source_date_epoch;
	26	long long epoch;
	27	@@ -12334,19 +12335,14 @@ get_source_date_epoch ()
	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	+ if (errno != 0 \|\| endptr == source_date_epoch \|\| *endptr != '\0'
	45	+ \|\| epoch < 0 \|\| epoch > MAX_SOURCE_DATE_EPOCH)
	46	+ {
	47	+ error_at (input_location, "environment variable SOURCE_DATE_EPOCH must "
	48	+ "expand to a non-negative integer less than or equal to %wd",
	49	+ MAX_SOURCE_DATE_EPOCH);
	50	+ return (time_t) -1;
	51	+ }
	52
	53	return (time_t) epoch;
	54	}
	55	diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
	56	index ba0a5d7df50..977ae9df5ea 100644
	57	--- a/gcc/c-family/c-common.h
	58	+++ b/gcc/c-family/c-common.h
	59	@@ -1063,6 +1063,16 @@ extern vec<tree, va_gc> make_tree_vector_copy (const vec<tree, va_gc> );
	60	c_register_builtin_type. */
	61	extern GTY(()) tree registered_builtin_types;
	62
	63	+/* Read SOURCE_DATE_EPOCH from environment to have a deterministic
	64	+ timestamp to replace embedded current dates to get reproducible
65	+ results. Returns -1 if SOURCE_DATE_EPOCH is not defined. */
66	+extern time_t cb_get_source_date_epoch (cpp_reader *pfile);
67	+
68	+/* The value (as a unix timestamp) corresponds to date
69	+ "Dec 31 9999 23:59:59 UTC", which is the latest date that __DATE__ and
70	+ __TIME__ can store. */
71	+#define MAX_SOURCE_DATE_EPOCH HOST_WIDE_INT_C (253402300799)
72	+
73	/* In c-gimplify.c */
74	extern void c_genericize (tree);
75	extern int c_gimplify_expr (tree , gimple_seq , gimple_seq *);
76	@@ -1438,9 +1448,4 @@ extern tree cilk_for_number_of_iterations (tree);
77	extern bool check_no_cilk (tree, const char , const char ,
78	location_t loc = UNKNOWN_LOCATION);
79
80	-/* Read SOURCE_DATE_EPOCH from environment to have a deterministic
81	- timestamp to replace embedded current dates to get reproducible
82	- results. Returns -1 if SOURCE_DATE_EPOCH is not defined. */
83	-extern time_t get_source_date_epoch (void);
84	-
85	#endif /* ! GCC_C_COMMON_H */
86	diff --git a/gcc/c-family/c-lex.c b/gcc/c-family/c-lex.c
87	index e68471b9d2b..3f78073f640 100644
88	--- a/gcc/c-family/c-lex.c
89	+++ b/gcc/c-family/c-lex.c
90	@@ -97,6 +97,7 @@ init_c_lex (void)
91	cb->valid_pch = c_common_valid_pch;
92	cb->read_pch = c_common_read_pch;
93	cb->has_attribute = c_common_has_attribute;
94	+ cb->get_source_date_epoch = cb_get_source_date_epoch;
95
96	/* Set the debug callbacks if we can use them. */
97	if ((debug_info_level == DINFO_LEVEL_VERBOSE
98	@@ -402,9 +403,6 @@ c_lex_with_flags (tree value, location_t loc, unsigned char *cpp_flags,
99	enum cpp_ttype type;
100	unsigned char add_flags = 0;
101	enum overflow_type overflow = OT_NONE;
102	- time_t source_date_epoch = get_source_date_epoch ();
103	-
104	- cpp_init_source_date_epoch (parse_in, source_date_epoch);
105
106	timevar_push (TV_CPP);
107	retry:
108	diff --git a/gcc/doc/cppenv.texi b/gcc/doc/cppenv.texi
109	index 3b5317beb53..7b4cf6adc11 100644
110	--- a/gcc/doc/cppenv.texi
111	+++ b/gcc/doc/cppenv.texi
112	@@ -81,7 +81,6 @@ main input file is omitted.
113	@end ifclear
114
115	@item SOURCE_DATE_EPOCH
116	-
117	If this variable is set, its value specifies a UNIX timestamp to be
118	used in replacement of the current date and time in the @code{__DATE__}
119	and @code{__TIME__} macros, so that the embedded timestamps become
120	@@ -89,8 +88,9 @@ reproducible.
121
122	The value of @env{SOURCE_DATE_EPOCH} must be a UNIX timestamp,
123	defined as the number of seconds (excluding leap seconds) since
124	-01 Jan 1970 00:00:00 represented in ASCII, identical to the output of
125	-@samp{@command{date +%s}}.
126	+01 Jan 1970 00:00:00 represented in ASCII; identical to the output of
127	+@samp{@command{date +%s}} on GNU/Linux and other systems that support the
128	+@code{%s} extension in the @code{date} command.
129
130	The value should be a known timestamp such as the last modification
131	time of the source or package and it should be set by the build
132	diff --git a/gcc/gcc.c b/gcc/gcc.c
133	index d956c36b151..2709f295734 100644
134	--- a/gcc/gcc.c
135	+++ b/gcc/gcc.c
136	@@ -3328,6 +3328,29 @@ save_switch (const char opt, size_t n_args, const char const *args,
137	n_switches++;
138	}
139
140	+/* Set the SOURCE_DATE_EPOCH environment variable to the current time if it is
141	+ not set already. */
142	+
143	+static void
144	+set_source_date_epoch_envvar ()
145	+{
146	+ /* Array size is 21 = ceil(log_10(2^64)) + 1 to hold string representations
147	+ of 64 bit integers. */
148	+ char source_date_epoch[21];
149	+ time_t tt;
150	+
151	+ errno = 0;
152	+ tt = time (NULL);
153	+ if (tt < (time_t) 0 \|\| errno != 0)
154	+ tt = (time_t) 0;
155	+
156	+ snprintf (source_date_epoch, 21, "%llu", (unsigned long long) tt);
157	+ /* Using setenv instead of xputenv because we want the variable to remain
158	+ after finalizing so that it's still set in the second run when using
159	+ -fcompare-debug. */
160	+ setenv ("SOURCE_DATE_EPOCH", source_date_epoch, 0);
161	+}
162	+
163	/* Handle an option DECODED that is unknown to the option-processing
164	machinery. */
165
166	@@ -3628,6 +3651,7 @@ driver_handle_option (struct gcc_options *opts,
167	else
168	compare_debug_opt = arg;
169	save_switch (compare_debug_replacement_opt, 0, NULL, validated, true);
170	+ set_source_date_epoch_envvar ();
171	return true;
172
173	case OPT_fdiagnostics_color_:
174	diff --git a/gcc/testsuite/gcc.dg/cpp/source_date_epoch-1.c b/gcc/testsuite/gcc.dg/cpp/source_date_epoch-1.c
175	new file mode 100644
176	index 00000000000..f6aa1a360ff
177	--- /dev/null
178	+++ b/gcc/testsuite/gcc.dg/cpp/source_date_epoch-1.c
179	@@ -0,0 +1,11 @@
180	+/* { dg-do run } */
181	+/* { dg-set-compiler-env-var SOURCE_DATE_EPOCH "630333296" } */
182	+
183	+int
184	+main(void)
185	+{
186	+ __builtin_printf ("%s %s\n", __DATE__, __TIME__);
187	+ return 0;
188	+}
189	+
190	+/* { dg-output "^Dec 22 1989 12:34:56\n$" } */
191	diff --git a/gcc/testsuite/gcc.dg/cpp/source_date_epoch-2.c b/gcc/testsuite/gcc.dg/cpp/source_date_epoch-2.c
192	new file mode 100644
193	index 00000000000..ae18362ae87
194	--- /dev/null
195	+++ b/gcc/testsuite/gcc.dg/cpp/source_date_epoch-2.c
196	@@ -0,0 +1,12 @@
197	+/* { dg-do compile } */
198	+/* { dg-set-compiler-env-var SOURCE_DATE_EPOCH "AAA" } */
199	+
200	+/* Make sure that SOURCE_DATE_EPOCH is only parsed once */
201	+
202	+int
203	+main(void)
204	+{
205	+ __builtin_printf ("%s %s\n", __DATE__, __TIME__); /* { dg-error "SOURCE_DATE_EPOCH must expand" } */
206	+ __builtin_printf ("%s %s\n", __DATE__, __TIME__);
207	+ return 0;
208	+}
209	diff --git a/gcc/testsuite/lib/gcc-dg.exp b/gcc/testsuite/lib/gcc-dg.exp
210	index 4fa433d9954..7656b2254a1 100644
211	--- a/gcc/testsuite/lib/gcc-dg.exp
212	+++ b/gcc/testsuite/lib/gcc-dg.exp
213	@@ -324,6 +324,38 @@ proc restore-target-env-var { } {
214	}
215	}
216
217	+proc dg-set-compiler-env-var { args } {
218	+ global set_compiler_env_var
219	+ global saved_compiler_env_var
220	+ if { [llength $args] != 3 } {
221	+ error "dg-set-compiler-env-var: need two arguments"
222	+ return
223	+ }
224	+ set var [lindex $args 1]
225	+ set value [lindex $args 2]
226	+ if [info exists ::env($var)] {
227	+ lappend saved_compiler_env_var [list $var 1 $::env($var)]
228	+ } else {
229	+ lappend saved_compiler_env_var [list $var 0]
230	+ }
231	+ setenv $var $value
232	+ lappend set_compiler_env_var [list $var $value]
233	+}
234	+
235	+proc restore-compiler-env-var { } {
236	+ global saved_compiler_env_var
237	+ for { set env_vari [llength $saved_compiler_env_var] } {
238	+ [incr env_vari -1] >= 0 } {} {
239	+ set env_var [lindex $saved_compiler_env_var $env_vari]
240	+ set var [lindex $env_var 0]
241	+ if [lindex $env_var 1] {
242	+ setenv $var [lindex $env_var 2]
243	+ } else {
244	+ unsetenv $var
245	+ }
246	+ }
247	+}
248	+
249	# Utility routines.
250
251	#
252	@@ -785,6 +817,11 @@ if { [info procs saved-dg-test] == [list] } {
253	if [info exists set_target_env_var] {
254	unset set_target_env_var
255	}
256	+ if [info exists set_compiler_env_var] {
257	+ restore-compiler-env-var
258	+ unset set_compiler_env_var
259	+ unset saved_compiler_env_var
260	+ }
261	unset_timeout_vars
262	if [info exists compiler_conditional_xfail_data] {
263	unset compiler_conditional_xfail_data
264	diff --git a/libcpp/include/cpplib.h b/libcpp/include/cpplib.h
265	index 7a5481219be..867aeebc39f 100644
266	--- a/libcpp/include/cpplib.h
267	+++ b/libcpp/include/cpplib.h
268	@@ -585,6 +585,9 @@ struct cpp_callbacks
269
270	/* Callback that can change a user builtin into normal macro. */
271	bool (user_builtin_macro) (cpp_reader , cpp_hashnode *);
272	+
273	+ /* Callback to parse SOURCE_DATE_EPOCH from environment. */
274	+ time_t (get_source_date_epoch) (cpp_reader );
275	};
276
277	#ifdef VMS
278	@@ -775,9 +778,6 @@ extern void cpp_init_special_builtins (cpp_reader *);
279	/* Set up built-ins like __FILE__. */
280	extern void cpp_init_builtins (cpp_reader *, int);
281
282	-/* Initialize the source_date_epoch value. */
283	-extern void cpp_init_source_date_epoch (cpp_reader *, time_t);
284	-
285	/* This is called after options have been parsed, and partially
286	processed. */
287	extern void cpp_post_options (cpp_reader *);
288	diff --git a/libcpp/init.c b/libcpp/init.c
289	index a8d00f4628b..61c9bbbf945 100644
290	--- a/libcpp/init.c
291	+++ b/libcpp/init.c
292	@@ -254,6 +254,9 @@ cpp_create_reader (enum c_lang lang, cpp_hash_table *table,
293	/* Do not force token locations by default. */
294	pfile->forced_token_location_p = NULL;
295
296	+ /* Initialize source_date_epoch to -2 (not yet set). */
297	+ pfile->source_date_epoch = (time_t) -2;
298	+
299	/* The expression parser stack. */
300	_cpp_expand_op_stack (pfile);
301
302	@@ -530,13 +533,6 @@ cpp_init_builtins (cpp_reader *pfile, int hosted)
303	_cpp_define_builtin (pfile, "__OBJC__ 1");
304	}
305
306	-/* Initialize the source_date_epoch value. */
307	-void
308	-cpp_init_source_date_epoch (cpp_reader *pfile, time_t source_date_epoch)
309	-{
310	- pfile->source_date_epoch = source_date_epoch;
311	-}
312	-
313	/* Sanity-checks are dependent on command-line options, so it is
314	called as a subroutine of cpp_read_main_file (). */
315	#if ENABLE_CHECKING
316	diff --git a/libcpp/internal.h b/libcpp/internal.h
317	index 8507eba1747..226ae328e76 100644
318	--- a/libcpp/internal.h
319	+++ b/libcpp/internal.h
320	@@ -503,7 +503,8 @@ struct cpp_reader
321	const unsigned char *time;
322
323	/* Externally set timestamp to replace current date and time useful for
324	- reproducibility. */
325	+ reproducibility. It should be initialized to -2 (not yet set) and
326	+ set to -1 to disable it or to a non-negative value to enable it. */
327	time_t source_date_epoch;
328
329	/* EOF token, and a token forcing paste avoidance. */
330	diff --git a/libcpp/macro.c b/libcpp/macro.c
331	index 3f3b278e97d..756c7c6e0c6 100644
332	--- a/libcpp/macro.c
333	+++ b/libcpp/macro.c
334	@@ -351,9 +351,13 @@ _cpp_builtin_macro_text (cpp_reader pfile, cpp_hashnode node)
335	struct tm *tb = NULL;
336
337	/* Set a reproducible timestamp for __DATE__ and __TIME__ macro
338	- usage if SOURCE_DATE_EPOCH is defined. */
339	- if (pfile->source_date_epoch != (time_t) -1)
340	- tb = gmtime (&pfile->source_date_epoch);
341	+ if SOURCE_DATE_EPOCH is defined. */
342	+ if (pfile->source_date_epoch == (time_t) -2
343	+ && pfile->cb.get_source_date_epoch != NULL)
344	+ pfile->source_date_epoch = pfile->cb.get_source_date_epoch (pfile);
345	+
346	+ if (pfile->source_date_epoch >= (time_t) 0)
347	+ tb = gmtime (&pfile->source_date_epoch);
348	else
349	{
350	/* (time_t) -1 is a legitimate value for "number of seconds
351	--
352	2.11.0
353