[musl] [C23 time 1/1] C23: add timespec_getres and deprecate asctime and ctime

[musl] [C23 time 1/1] C23: add timespec_getres and deprecate asctime and ctime

[Jens Gustedt]

The identifier timespec_getres was not reserved before so we have to
protect it against includes by older C versions and make the symbol
weak, so it doesn't conflict with potential user code.

The implementation just uses clock_getres underneath, which forces
that function also to be weak such that we don't link with that symbol
accidentally in pure C mode.

Deprecate asctime and ctime. These are also deprecated by POSIX,
so there should not be a conflict between the two standards.

Also, use the __STDC_VERSION_TIME_H__ macro, this still have to be
adapted to the final value that will be decided by WG14 for
__STDC_VERSION__.
---
 include/time.h             |  9 +++++----
 src/time/clock_getres.c    |  4 +++-
 src/time/timespec_getres.c | 12 ++++++++++++
 3 files changed, 20 insertions(+), 5 deletions(-)
 create mode 100644 src/time/timespec_getres.c

diff --git a/include/time.h b/include/time.h
index e94b3a01..074a64e1 100644
--- a/include/time.h
+++ b/include/time.h
@@ -1,5 +1,5 @@
-#ifndef	_TIME_H
-#define _TIME_H
+#ifndef	__STDC_VERSION_TIME_H__
+#define __STDC_VERSION_TIME_H__ 202300L
 
 #ifdef __cplusplus
 extern "C" {
@@ -58,8 +58,8 @@ time_t mktime (struct tm *);
 size_t strftime (char *__restrict, size_t, const char *__restrict, const struct tm *__restrict);
 struct tm *gmtime (const time_t *);
 struct tm *localtime (const time_t *);
-char *asctime (const struct tm *);
-char *ctime (const time_t *);
+__deprecated char *asctime(const struct tm *);
+__deprecated char *ctime(const time_t *);
 int timespec_get(struct timespec *, int);
 
 #define CLOCKS_PER_SEC 1000000L
@@ -69,6 +69,7 @@ int timespec_get(struct timespec *, int);
 struct tm *gmtime_r (const time_t *__restrict, struct tm *__restrict);
 struct tm *localtime_r (const time_t *__restrict, struct tm *__restrict);
 time_t timegm(struct tm *);
+int timespec_getres(struct timespec *, int);
 
 #if defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) \
  || defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) \
diff --git a/src/time/clock_getres.c b/src/time/clock_getres.c
index 81c67037..248e6d18 100644
--- a/src/time/clock_getres.c
+++ b/src/time/clock_getres.c
@@ -1,7 +1,7 @@
 #include <time.h>
 #include "syscall.h"
 
-int clock_getres(clockid_t clk, struct timespec *ts)
+int __clock_getres(clockid_t clk, struct timespec *ts)
 {
 #ifdef SYS_clock_getres_time64
 	/* On a 32-bit arch, use the old syscall if it exists. */
@@ -19,3 +19,5 @@ int clock_getres(clockid_t clk, struct timespec *ts)
 	 * 32-bit arch and we can get result directly into timespec. */
 	return syscall(SYS_clock_getres, clk, ts);
 }
+
+weak_alias(__clock_getres, clock_getres);
diff --git a/src/time/timespec_getres.c b/src/time/timespec_getres.c
new file mode 100644
index 00000000..6ecbbdc4
--- /dev/null
+++ b/src/time/timespec_getres.c
@@ -0,0 +1,12 @@
+#include <time.h>
+
+extern int __clock_getres(clockid_t clk, struct timespec *ts);
+
+/* There is no other implemented value than TIME_UTC; all other values
+ * are considered erroneous. */
+int timespec_getres(struct timespec * ts, int base)
+{
+	if (base != TIME_UTC) return 0;
+	int ret = __clock_getres(CLOCK_REALTIME, ts);
+	return ret < 0 ? 0 : base;
+}
-- 
2.34.1

[musl] [C23 time 1/1] C23: add timespec_getres and deprecate asctime and ctime

[Jens Gustedt]

The identifier timespec_getres was not reserved before so we have to
protect it against includes by older C versions and make the symbol
weak, so it doesn't conflict with potential user code.

The implementation just uses clock_getres underneath, which forces
that function also to be weak such that we don't link with that symbol
accidentally in pure C mode.

Deprecate asctime and ctime. These are also deprecated by POSIX,
so there should not be a conflict between the two standards.

Also, use the __STDC_VERSION_TIME_H__ macro, this still have to be
adapted to the final value that will be decided by WG14 for
__STDC_VERSION__.
---
 include/time.h             |  9 +++++----
 src/time/clock_getres.c    |  4 +++-
 src/time/timespec_getres.c | 12 ++++++++++++
 3 files changed, 20 insertions(+), 5 deletions(-)
 create mode 100644 src/time/timespec_getres.c

diff --git a/include/time.h b/include/time.h
index e94b3a01..074a64e1 100644
--- a/include/time.h
+++ b/include/time.h
@@ -1,5 +1,5 @@
-#ifndef	_TIME_H
-#define _TIME_H
+#ifndef	__STDC_VERSION_TIME_H__
+#define __STDC_VERSION_TIME_H__ 202300L
 
 #ifdef __cplusplus
 extern "C" {
@@ -58,8 +58,8 @@ time_t mktime (struct tm *);
 size_t strftime (char *__restrict, size_t, const char *__restrict, const struct tm *__restrict);
 struct tm *gmtime (const time_t *);
 struct tm *localtime (const time_t *);
-char *asctime (const struct tm *);
-char *ctime (const time_t *);
+__deprecated char *asctime(const struct tm *);
+__deprecated char *ctime(const time_t *);
 int timespec_get(struct timespec *, int);
 
 #define CLOCKS_PER_SEC 1000000L
@@ -69,6 +69,7 @@ int timespec_get(struct timespec *, int);
 struct tm *gmtime_r (const time_t *__restrict, struct tm *__restrict);
 struct tm *localtime_r (const time_t *__restrict, struct tm *__restrict);
 time_t timegm(struct tm *);
+int timespec_getres(struct timespec *, int);
 
 #if defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) \
  || defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) \
diff --git a/src/time/clock_getres.c b/src/time/clock_getres.c
index 81c67037..248e6d18 100644
--- a/src/time/clock_getres.c
+++ b/src/time/clock_getres.c
@@ -1,7 +1,7 @@
 #include <time.h>
 #include "syscall.h"
 
-int clock_getres(clockid_t clk, struct timespec *ts)
+int __clock_getres(clockid_t clk, struct timespec *ts)
 {
 #ifdef SYS_clock_getres_time64
 	/* On a 32-bit arch, use the old syscall if it exists. */
@@ -19,3 +19,5 @@ int clock_getres(clockid_t clk, struct timespec *ts)
 	 * 32-bit arch and we can get result directly into timespec. */
 	return syscall(SYS_clock_getres, clk, ts);
 }
+
+weak_alias(__clock_getres, clock_getres);
diff --git a/src/time/timespec_getres.c b/src/time/timespec_getres.c
new file mode 100644
index 00000000..6ecbbdc4
--- /dev/null
+++ b/src/time/timespec_getres.c
@@ -0,0 +1,12 @@
+#include <time.h>
+
+extern int __clock_getres(clockid_t clk, struct timespec *ts);
+
+/* There is no other implemented value than TIME_UTC; all other values
+ * are considered erroneous. */
+int timespec_getres(struct timespec * ts, int base)
+{
+	if (base != TIME_UTC) return 0;
+	int ret = __clock_getres(CLOCK_REALTIME, ts);
+	return ret < 0 ? 0 : base;
+}
-- 
2.34.1