Don't include features.h in H5public.h (#5818)

This file is intended for internal glibc use and should not be included
from user code. Instead, you are supposed to set appropriate feature
test macros like _POSIX_C_SOURCE before including C/POSIX library
headers, which we already do.

Author: derobins

config/ConfigureChecks.cmake

@@ -135,7 +135,6 @@ CHECK_INCLUDE_FILE_CONCAT ("sys/socket.h"    ${HDF_PREFIX}_HAVE_SYS_SOCKET_H)
 CHECK_INCLUDE_FILE_CONCAT ("sys/stat.h"      ${HDF_PREFIX}_HAVE_SYS_STAT_H)
 CHECK_INCLUDE_FILE_CONCAT ("sys/time.h"      ${HDF_PREFIX}_HAVE_SYS_TIME_H)
 CHECK_INCLUDE_FILE_CONCAT ("sys/types.h"     ${HDF_PREFIX}_HAVE_SYS_TYPES_H)
-CHECK_INCLUDE_FILE_CONCAT ("features.h"      ${HDF_PREFIX}_HAVE_FEATURES_H)
 CHECK_INCLUDE_FILE_CONCAT ("dirent.h"        ${HDF_PREFIX}_HAVE_DIRENT_H)
 CHECK_INCLUDE_FILE_CONCAT ("unistd.h"        ${HDF_PREFIX}_HAVE_UNISTD_H)
 CHECK_INCLUDE_FILE_CONCAT ("pwd.h"           ${HDF_PREFIX}_HAVE_PWD_H)
@@ -1129,4 +1128,4 @@ else ()
   set (${HDF_PREFIX}_HAVE_PKGCONFIG 0)
 endif ()
 
-#-----------------------------------------------------------------------------
+#-----------------------------------------------------------------------------

config/H5pubconf.h.in

@@ -128,9 +128,6 @@
 /* Define to 1 if you have the `fcntl' function. */
 #cmakedefine H5_HAVE_FCNTL @H5_HAVE_FCNTL@
 
-/* Define to 1 if you have the <features.h> header file. */
-#cmakedefine H5_HAVE_FEATURES_H @H5_HAVE_FEATURES_H@
-
 /* Define if support for deflate (zlib) filter is enabled */
 #cmakedefine H5_HAVE_FILTER_DEFLATE @H5_HAVE_FILTER_DEFLATE@
 

release_docs/RELEASE.txt

@@ -217,6 +217,12 @@ New Features
 
     Library:
     --------
+    - H5public.h no longer includes features.h
+
+      features.h is supposed to be included by glibc headers and not used in
+      application code. It is unnecessary given our use of feature test macros
+      like _POSIX_C_SOURCE and has been removed.
+
     - Improved performance of opening a virtual dataset with many mappings
 
       When opening a virtual dataset, the library would previously decode

src/H5public.h

@@ -22,10 +22,6 @@
 /* API Version macro wrapper definitions */
 #include "H5version.h"
 
-#ifdef H5_HAVE_FEATURES_H
-#include <features.h> /* For setting POSIX, BSD, etc. compatibility */
-#endif
-
 /* C library header files for things that appear in HDF5 public headers */
 #ifdef __cplusplus
 #include <cinttypes>