Newlib: Added enviroment emulation via the file /sys/settings/system.env

git-svn-id: svn://kolibrios.org@9959 a494cfbc-eb01-0410-851d-a64ba20cac60

contrib/sdk/sources/newlib/libc/stdlib/envlock.c

@@ -0,0 +1,61 @@
+/*
+FUNCTION
+<<__env_lock>>, <<__env_unlock>>---lock environ variable
+
+INDEX
+	__env_lock
+INDEX
+	__env_unlock
+
+ANSI_SYNOPSIS
+	#include <envlock.h>
+	void __env_lock (struct _reent *<[reent]>);
+	void __env_unlock (struct _reent *<[reent]>);
+
+TRAD_SYNOPSIS
+	void __env_lock(<[reent]>)
+	struct _reent *<[reent]>;
+
+	void __env_unlock(<[reent]>)
+	struct _reent *<[reent]>;
+
+DESCRIPTION
+The <<setenv>> family of routines call these functions when they need to
+modify the environ variable.  The version of these routines supplied in the
+library use the lock API defined in sys/lock.h.  If multiple threads of
+execution can call <<setenv>>, or if <<setenv>> can be called reentrantly,
+then you need to define your own versions of these functions in order to
+safely lock the memory pool during a call.  If you do not, the memory pool
+may become corrupted.
+
+A call to <<setenv>> may call <<__env_lock>> recursively; that is,
+the sequence of calls may go <<__env_lock>>, <<__env_lock>>,
+<<__env_unlock>>, <<__env_unlock>>.  Any implementation of these
+routines must be careful to avoid causing a thread to wait for a lock
+that it already holds.
+*/
+
+#include "envlock.h"
+#include <sys/lock.h>
+
+#ifndef __SINGLE_THREAD__
+__LOCK_INIT_RECURSIVE(static, __env_lock_object);
+#endif
+
+void
+_EXFUN(__env_lock,
+      (struct _reent *reent))
+{
+#ifndef __SINGLE_THREAD__
+  __lock_acquire_recursive (__env_lock_object);
+#endif
+}
+
+void 
+_EXFUN(__env_unlock,
+      (struct _reent *reent))
+{
+#ifndef __SINGLE_THREAD__
+  __lock_release_recursive (__env_lock_object);
+#endif
+}

contrib/sdk/sources/newlib/libc/stdlib/getenv.c

@@ -73,7 +73,7 @@ _DEFUN (_findenv, (name, offset),
 	register _CONST char *name _AND
 	int *offset)
 {
-  return NULL; //_findenv_r (_REENT, name, offset);
+  return _findenv_r (_REENT, name, offset);
 }
 
 /*
@@ -86,8 +86,7 @@ _DEFUN (getenv, (name),
 	_CONST char *name)
 {
   int offset;
-
-  return NULL; //_findenv_r (_REENT, name, &offset);
+  return _findenv_r (_REENT, name, &offset);
 }
 
 #endif /* !_REENT_ONLY */

contrib/sdk/sources/newlib/libc/stdlib/getenv_r.c

@@ -85,6 +85,37 @@ _DEFUN (_findenv_r, (reent_ptr, name, offset),
 	register _CONST char *name _AND
 	int *offset)
 {
+  register int len;
+  register char **p;
+  _CONST char *c;
+
+  ENV_LOCK;
+
+  /* In some embedded systems, this does not get set.  This protects
+     newlib from dereferencing a bad pointer.  */
+  if (!*p_environ)
+    {
+      ENV_UNLOCK;
+      return NULL;
+    }
+
+  c = name;
+  while (*c && *c != '=')  c++;
+ 
+  /* Identifiers may not contain an '=', so cannot match if does */
+  if(*c != '=')
+    {
+    len = c - name;
+    for (p = *p_environ; *p; ++p)
+      if (!strncmp (*p, name, len))
+        if (*(c = *p + len) == '=')
+	{
+	  *offset = p - *p_environ;
+	  ENV_UNLOCK;
+	  return (char *) (++c);
+	}
+    }
+  ENV_UNLOCK;
   return NULL;
 }
 
@@ -100,6 +131,5 @@ _DEFUN (_getenv_r, (reent_ptr, name),
 {
   int offset;
 
-  return NULL;
-//  return _findenv_r (reent_ptr, name, &offset);
+  return _findenv_r (reent_ptr, name, &offset);
 }