posix: move limit definitions to common libc limits.h

In order to reduce conflicts with limits defined in external C libraries,
move Zephyr's POSIX limits from posix_features.h to limits.h in the
common C library sources.

In order to give the implementation better control over where POSIX
limit definitions originate, use `#include_next <limits.h>` to pull in
the corresponding header of the C library, and provide a non-user
configurable option `CONFIG_TC_PROVIDES_POSIX_LIMIT_DEFS` that may be set
in order to ensure that the C library version of POSIX limits are used.

Note: this may mean that runtime invariant values are inconsistent with
parts that are actually in use within Zephyr, so applications are
encouraged to use `sysconf()` with external C libraries that implement
parts of the POSIX standard to query system configuration values at
runtime.

Signed-off-by: Chris Friedt <[email protected]>

Author: cfriedt

include/zephyr/posix/sys/dirent.h

@@ -9,8 +9,6 @@
 
 #include <limits.h>
 
-#include <zephyr/posix/posix_features.h>
-
 #if !defined(NAME_MAX) && defined(_XOPEN_SOURCE)
 #define NAME_MAX _XOPEN_NAME_MAX
 #endif

lib/libc/Kconfig

@@ -103,6 +103,7 @@ config PICOLIBC
 	imply THREAD_LOCAL_STORAGE if ARCH_HAS_THREAD_LOCAL_STORAGE && TOOLCHAIN_SUPPORTS_THREAD_LOCAL_STORAGE
 	select LIBC_ERRNO if THREAD_LOCAL_STORAGE
 	select NEED_LIBC_MEM_PARTITION
+	select TC_PROVIDES_POSIX_LIMIT_DEFS
 	select TC_PROVIDES_POSIX_C_LANG_SUPPORT_R
 	imply COMMON_LIBC_MALLOC
 	imply COMMON_LIBC_ABORT

lib/libc/common/include/limits.h

@@ -0,0 +1,136 @@
+/*
+ * Copyright The Zephyr Project Contributors
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef ZEPHYR_LIB_LIBC_COMMON_INCLUDE_LIMITS_H_
+#define ZEPHYR_LIB_LIBC_COMMON_INCLUDE_LIMITS_H_
+
+#include_next <limits.h>
+
+#if !defined(CONFIG_TC_PROVIDES_POSIX_LIMIT_DEFS)
+
+#if defined(_POSIX_C_SOURCE) || defined(__DOXYGEN__)
+
+/*
+ * clang-format and checkpatch disagree on formatting here, so use rely and checkpatch and disable
+ * clang-format since the checkpatch cannot be selectively disabled.
+ */
+
+/* clang-format off */
+
+/* Maximum values */
+#define _POSIX_CLOCKRES_MIN (20000000L)
+
+/* Minimum values */
+#define _POSIX_AIO_LISTIO_MAX               (2)
+#define _POSIX_AIO_MAX                      (1)
+#define _POSIX_ARG_MAX                      (4096)
+#define _POSIX_CHILD_MAX                    (25)
+#define _POSIX_DELAYTIMER_MAX               (32)
+#define _POSIX_HOST_NAME_MAX                (255)
+#define _POSIX_LINK_MAX                     (8)
+#define _POSIX_LOGIN_NAME_MAX               (9)
+#define _POSIX_MAX_CANON                    (255)
+#define _POSIX_MAX_INPUT                    (255)
+#define _POSIX_MQ_OPEN_MAX                  (8)
+#define _POSIX_MQ_PRIO_MAX                  (32)
+#define _POSIX_NAME_MAX                     (14)
+#define _POSIX_NGROUPS_MAX                  (8)
+#define _POSIX_OPEN_MAX                     (20)
+#define _POSIX_PATH_MAX                     (256)
+#define _POSIX_PIPE_BUF                     (512)
+#define _POSIX_RE_DUP_MAX                   (255)
+#define _POSIX_RTSIG_MAX                    (8)
+#define _POSIX_SEM_NSEMS_MAX                (256)
+#define _POSIX_SEM_VALUE_MAX                (32767)
+#define _POSIX_SIGQUEUE_MAX                 (32)
+#define _POSIX_SSIZE_MAX                    (32767)
+#define _POSIX_SS_REPL_MAX                  (4)
+#define _POSIX_STREAM_MAX                   (8)
+#define _POSIX_SYMLINK_MAX                  (255)
+#define _POSIX_SYMLOOP_MAX                  (8)
+#define _POSIX_THREAD_DESTRUCTOR_ITERATIONS (4)
+#define _POSIX_THREAD_KEYS_MAX              (128)
+#define _POSIX_THREAD_THREADS_MAX           (64)
+#define _POSIX_TIMER_MAX                    (32)
+#define _POSIX_TRACE_EVENT_NAME_MAX         (30)
+#define _POSIX_TRACE_NAME_MAX               (8)
+#define _POSIX_TRACE_SYS_MAX                (8)
+#define _POSIX_TRACE_USER_EVENT_MAX         (32)
+#define _POSIX_TTY_NAME_MAX                 (9)
+#define _POSIX_TZNAME_MAX                   (6)
+#define _POSIX2_BC_BASE_MAX                 (99)
+#define _POSIX2_BC_DIM_MAX                  (2048)
+#define _POSIX2_BC_SCALE_MAX                (99)
+#define _POSIX2_BC_STRING_MAX               (1000)
+#define _POSIX2_CHARCLASS_NAME_MAX          (14)
+#define _POSIX2_COLL_WEIGHTS_MAX            (2)
+#define _POSIX2_EXPR_NEST_MAX               (32)
+#define _POSIX2_LINE_MAX                    (2048)
+#define _XOPEN_IOV_MAX                      (16)
+#define _XOPEN_NAME_MAX                     (255)
+#define _XOPEN_PATH_MAX                     (1024)
+
+/* Other invariant values */
+#define NL_LANGMAX (14)
+#define NL_MSGMAX  (32767)
+#define NL_SETMAX  (255)
+#define NL_TEXTMAX (_POSIX2_LINE_MAX)
+#define NZERO      (20)
+
+/* Runtime invariant values */
+#define AIO_LISTIO_MAX                _POSIX_AIO_LISTIO_MAX
+#define AIO_MAX                       _POSIX_AIO_MAX
+#define AIO_PRIO_DELTA_MAX            (0)
+#define ARG_MAX                       _POSIX_ARG_MAX
+#define ATEXIT_MAX                    (32)
+#define DELAYTIMER_MAX \
+	COND_CODE_1(CONFIG_POSIX_TIMERS, (CONFIG_POSIX_DELAYTIMER_MAX), (0))
+#define HOST_NAME_MAX \
+	COND_CODE_1(CONFIG_POSIX_NETWORKING, (CONFIG_POSIX_HOST_NAME_MAX), (0))
+#define LOGIN_NAME_MAX                _POSIX_LOGIN_NAME_MAX
+#define MQ_OPEN_MAX \
+	COND_CODE_1(CONFIG_POSIX_MESSAGE_PASSING, (CONFIG_POSIX_MQ_OPEN_MAX), (0))
+#define MQ_PRIO_MAX                   _POSIX_MQ_PRIO_MAX
+#define OPEN_MAX                      CONFIG_POSIX_OPEN_MAX
+#define PAGE_SIZE                     CONFIG_POSIX_PAGE_SIZE
+#define PAGESIZE                      CONFIG_POSIX_PAGE_SIZE
+#undef PATH_MAX
+#define PATH_MAX                      _POSIX_PATH_MAX
+#define PTHREAD_DESTRUCTOR_ITERATIONS _POSIX_THREAD_DESTRUCTOR_ITERATIONS
+#define PTHREAD_KEYS_MAX \
+	COND_CODE_1(CONFIG_POSIX_THREADS, (CONFIG_POSIX_THREAD_KEYS_MAX), (0))
+#define PTHREAD_THREADS_MAX \
+	COND_CODE_1(CONFIG_POSIX_THREADS, (CONFIG_POSIX_THREAD_THREADS_MAX), (0))
+#define RTSIG_MAX \
+	COND_CODE_1(CONFIG_POSIX_REALTIME_SIGNALS, (CONFIG_POSIX_RTSIG_MAX), (0))
+#define SEM_NSEMS_MAX \
+	COND_CODE_1(CONFIG_POSIX_SEMAPHORES, (CONFIG_POSIX_SEM_NSEMS_MAX), (0))
+#define SEM_VALUE_MAX \
+	COND_CODE_1(CONFIG_POSIX_SEMAPHORES, (CONFIG_POSIX_SEM_VALUE_MAX), (0))
+#define SIGQUEUE_MAX                  _POSIX_SIGQUEUE_MAX
+#define STREAM_MAX                    _POSIX_STREAM_MAX
+#define SYMLOOP_MAX                   _POSIX_SYMLOOP_MAX
+#define TIMER_MAX \
+	COND_CODE_1(CONFIG_POSIX_TIMERS, (CONFIG_POSIX_TIMER_MAX), (0))
+#define TTY_NAME_MAX                  _POSIX_TTY_NAME_MAX
+#define TZNAME_MAX                    _POSIX_TZNAME_MAX
+
+/* Pathname variable values */
+#define FILESIZEBITS             (32)
+#define POSIX_ALLOC_SIZE_MIN     (256)
+#define POSIX_REC_INCR_XFER_SIZE (1024)
+#define POSIX_REC_MAX_XFER_SIZE  (32767)
+#define POSIX_REC_MIN_XFER_SIZE  (1)
+#define POSIX_REC_XFER_ALIGN     (4)
+#define SYMLINK_MAX              _POSIX_SYMLINK_MAX
+
+/* clang-format on */
+
+#endif /* defined(_POSIX_C_SOURCE) || defined(__DOXYGEN__) */
+
+#endif /* !defined(CONFIG_TC_PROVIDES_POSIX_LIMIT_DEFS) */
+
+#endif /* ZEPHYR_LIB_LIBC_COMMON_INCLUDE_LIMITS_H_ */

lib/posix/options/Kconfig.toolchain

@@ -13,6 +13,9 @@
 #
 # https://pubs.opengroup.org/onlinepubs/9699919799/xrat/V4_subprofiles.html
 
+config TC_PROVIDES_POSIX_LIMIT_DEFS
+	bool
+
 config TC_PROVIDES_POSIX_ASYNCHRONOUS_IO
 	bool