libio: Add POSIX user environment pointer to TCB

The IO library used a POSIX key to store an optional POSIX user
environment pointer.  This pulled in the POSIX keys support in every
application configuration.  Add a user environment pointer to the thread
control block (TCB) instead.  Applications which do not need the POSIX
user environment will just get an overhead of one pointer per thread.

Close #3882.

1 files changed, 4 insertions, 2 deletions

diff --git a/cpukit/include/rtems/userenv.h b/cpukit/include/rtems/userenv.h
index 7d6ffb05a5..2b66ee0951 100644
--- a/cpukit/include/rtems/userenv.h
+++ b/cpukit/include/rtems/userenv.h
@@ -53,10 +53,12 @@ extern "C" {
   #endif
 #endif
 
+typedef struct rtems_user_env_t rtems_user_env_t;
+
 /**
  * @brief User environment.
  */
-typedef struct {
+struct rtems_user_env_t {
   /**
    * @brief The anchor directory for relative paths.
    */
@@ -111,7 +113,7 @@ typedef struct {
    * @brief The list of supplementary group IDs.
    */
   gid_t groups[NGROUPS];
-} rtems_user_env_t;
+};
 
 extern rtems_user_env_t rtems_global_user_env;