posix: limits: de-duplicate limit logic

Rather than duplicating limit logic in several places, de-duplicate it
and centralize definitions for posix limits in posix_limits.h .

Additionally, reduce the number of bugs from 3 down to 1 where PATH_MAX
would be defined outside of standard usage.

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

Author: cfriedt

include/zephyr/posix/posix_limits.h

@@ -7,6 +7,12 @@
 #ifndef ZEPHYR_INCLUDE_ZEPHYR_POSIX_POSIX_LIMITS_H_
 #define ZEPHYR_INCLUDE_ZEPHYR_POSIX_POSIX_LIMITS_H_
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#if defined(_POSIX_C_SOURCE) || defined(__DOXYGEN__)
+
 /*
  * clang-format and checkpatch disagree on formatting here, so rely on checkpatch and disable
  * clang-format since checkpatch cannot be selectively disabled.
@@ -122,4 +128,15 @@
 
 /* clang-format on */
 
+#else
+
+/* FIXME: this should only be exposed when we define _POSIX_C_SOURCE or _XOPEN_SOURCE */
+#define PATH_MAX 256
+
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* ZEPHYR_INCLUDE_ZEPHYR_POSIX_POSIX_LIMITS_H_ */

lib/libc/arcmwdt/include/limits.h

@@ -8,23 +8,6 @@
 #define LIB_LIBC_ARCMWDT_INCLUDE_LIMITS_H_
 
 #include_next <limits.h>
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-#if defined(_POSIX_C_SOURCE) || defined(__DOXYGEN__)
-
 #include <zephyr/posix/posix_limits.h>
 
-#else
-
-#define PATH_MAX 256
-
-#endif
-
-#ifdef __cplusplus
-}
-#endif
-
 #endif  /* ZEPHYR_LIB_LIBC_ARMSTDC_INCLUDE_LIMITS_H_ */

lib/libc/armstdc/include/limits.h

@@ -8,23 +8,6 @@
 #define ZEPHYR_LIB_LIBC_ARMSTDC_INCLUDE_LIMITS_H_
 
 #include_next <limits.h>
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-#if defined(_POSIX_C_SOURCE) || defined(__DOXYGEN__)
-
 #include <zephyr/posix/posix_limits.h>
 
-#else
-
-#define PATH_MAX 256
-
-#endif
-
-#ifdef __cplusplus
-}
-#endif
-
 #endif  /* ZEPHYR_LIB_LIBC_ARMSTDC_INCLUDE_LIMITS_H_ */

lib/libc/iar/include/limits.h

@@ -8,23 +8,6 @@
 #define ZEPHYR_LIB_LIBC_IAR_INCLUDE_LIMITS_H_
 
 #include_next <limits.h>
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-#if defined(_POSIX_C_SOURCE) || defined(__DOXYGEN__)
-
 #include <zephyr/posix/posix_limits.h>
 
-#else
-
-#define PATH_MAX 256
-
-#endif
-
-#ifdef __cplusplus
-}
-#endif
-
 #endif /* ZEPHYR_LIB_LIBC_IAR_INCLUDE_LIMITS_H_ */