1 files changed, 269 insertions, 0 deletions
diff --git a/newlib/libc/signal/signal.c b/newlib/libc/signal/signal.c
new file mode 100644
index 00000000000..fc52bbab516
--- /dev/null
+++ b/newlib/libc/signal/signal.c
@@ -0,0 +1,269 @@
+/*
+FUNCTION
+<<signal>>---specify handler subroutine for a signal
+
+INDEX
+	signal
+INDEX
+	_signal_r
+INDEX
+	raise
+INDEX
+	_raise_r
+
+ANSI_SYNOPSIS
+	#include <signal.h>
+	void ( * signal(int <[sig]>, void(*<[func]>)(int)) )(int);
+
+	void ( * _signal_r(void *<[reent]>, 
+                           int <[sig]>, void(*<[func]>)(int)) )(int);
+
+	int raise (int <[sig]>);
+
+	int _raise_r (void *<[reent]>, int <[sig]>);
+
+TRAD_SYNOPSIS
+	#include <signal.h>
+	char ( * signal(<[sig]>, <[func]>) )()
+	int <[sig]>;
+	char ( * <[func]> )();
+
+	char ( * _signal_r(<[reent]>, <[sig]>, <[func]>) )()
+	char *<[reent]>;
+	int <[sig]>;
+	char ( * <[func]> )();
+
+	int raise (<[sig]>)()
+	int <[sig]>;
+
+	int _raise_r (<[reent]>, <[sig]>)()
+	char *<[reent]>;
+	int <[sig]>;
+
+DESCRIPTION
+<<signal, raise>> provide a simple signal/raise implementation for embedded
+targets.
+
+<<signal>> allows you to request changed treatment for a particular
+signal <[sig]>.  You can use one of the predefined macros <<SIG_DFL>>
+(select system default handling) or <<SIG_IGN>> (ignore this signal)
+as the value of <[func]>; otherwise, <[func]> is a function pointer
+that identifies a subroutine in your program as the handler for this signal.
+
+Some of the execution environment for signal handlers is
+unpredictable; notably, the only library function required to work
+correctly from within a signal handler is @code{signal} itself, and
+only when used to redefine the handler for the current signal value.
+
+Static storage is likewise unreliable for signal handlers, with one
+exception: if you declare a static storage location as `<<volatile
+sig_atomic_t>>', then you may use that location in a signal handler to
+store signal values.
+
+If your signal handler terminates using <<return>> (or implicit
+return), your program's execution continues at the point
+where it was when the signal was raised (whether by your program
+itself, or by an external event).  Signal handlers can also
+use functions such as <<exit>> and <<abort>> to avoid returning.
+
+<<raise>> sends the signal sig to the executing program.  It returns zero if
+successful, non-zero if unsuccessful.
+
+The alternate functions <<_signal_r, _raise_r>> are the reentrant versions.
+The extra argument <[reent]> is a pointer to a reentrancy structure.
+
+
+@c FIXME: do we have setjmp.h and assoc fns?
+
+RETURNS
+If your request for a signal handler cannot be honored, the result is
+<<SIG_ERR>>; a specific error number is also recorded in <<errno>>.
+
+Otherwise, the result is the previous handler (a function pointer or
+one of the predefined macros).
+
+PORTABILITY
+ANSI C requires <<raise>>, <<signal>>.
+
+No supporting OS subroutines are required to link with <<signal>>, but
+it will not have any useful effects, except for software generated signals,
+without an operating system that can actually raise exceptions.
+*/
+
+/*
+ * signal.c
+ * Original Author:	G. Haley
+ *
+ * signal associates the function pointed to by func with the signal sig. When
+ * a signal occurs, the value of func determines the action taken as follows:
+ * if func is SIG_DFL, the default handling for that signal will occur; if func
+ * is SIG_IGN, the signal will be ignored; otherwise, the default handling for
+ * the signal is restored (SIG_DFL), and the function func is called with sig
+ * as its argument. Returns the value of func for the previous call to signal
+ * for the signal sig, or SIG_ERR if the request fails.
+ */
+
+/* _init_signal initialises the signal handlers for each signal. This function
+   is called by crt0 at program startup.  */
+
+#ifdef SIGNAL_PROVIDED
+
+int _dummy_simulated_signal;
+
+#else
+
+#include <errno.h>
+#include <signal.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <reent.h>
+#include <_syslist.h>
+
+int
+_DEFUN (_init_signal_r, (ptr),
+	struct _reent *ptr)
+{
+  int i;
+
+  if (ptr->_sig_func == NULL)
+    {
+      ptr->_sig_func = (_sig_func_ptr *)_malloc_r (ptr, sizeof (_sig_func_ptr) * NSIG);
+      if (ptr->_sig_func == NULL)
+	return -1;
+
+      for (i = 0; i < NSIG; i++)
+	ptr->_sig_func[i] = SIG_DFL;
+    }
+
+  return 0;
+}
+
+_sig_func_ptr
+_DEFUN (_signal_r, (ptr, sig, func),
+	struct _reent *ptr _AND
+	int sig _AND
+	_sig_func_ptr func)
+{
+  _sig_func_ptr old_func, *temp;
+
+  if (sig < 0 || sig >= NSIG)
+    {
+      ptr->_errno = EINVAL;
+      return SIG_ERR;
+    }
+
+  if (ptr->_sig_func == NULL && _init_signal_r (ptr) != 0)
+    return SIG_ERR;
+  
+  old_func = ptr->_sig_func[sig];
+  ptr->_sig_func[sig] = func;
+
+  return old_func;
+}
+
+int 
+_raise_r (ptr, sig)
+     struct _reent *ptr;
+     int sig;
+{
+  _sig_func_ptr func;
+  int result = 0;
+
+  if (sig < 0 || sig >= NSIG)
+    {
+      ptr->_errno = EINVAL;
+      return -1;
+    }
+
+  if (ptr->_sig_func == NULL && _init_signal_r (ptr) != 0)
+    return -1;
+  
+  switch ((_POINTER_INT) ptr->_sig_func[sig])
+    {
+    case SIG_DFL:
+      return _kill_r (ptr, _getpid_r (ptr), sig);
+
+    case SIG_IGN:
+      break;
+
+    case SIG_ERR:
+      ptr->_errno = EINVAL;
+      result = 1;
+      break;
+
+    default:
+      func = ptr->_sig_func[sig];
+      ptr->_sig_func[sig] = SIG_DFL;
+      func (sig);
+      break;
+    }
+
+  return result;
+}
+
+int
+__sigtramp_r (ptr, sig)
+     struct _reent *ptr;
+     int sig;
+{
+  _sig_func_ptr func;
+
+  if (sig < 0 || sig >= NSIG)
+    {
+      return -1;
+    }
+
+  if (ptr->_sig_func == NULL && _init_signal_r (ptr) != 0)
+    return -1;
+  
+  switch ((_POINTER_INT) ptr->_sig_func[sig])
+    {
+    case SIG_DFL:
+      return 1;
+
+    case SIG_ERR:
+      return 2;
+
+    case SIG_IGN:
+      return 3;
+
+    default:
+      func = ptr->_sig_func[sig];
+      ptr->_sig_func[sig] = SIG_DFL;
+      func (sig);
+      return 0;
+    }
+}
+
+#ifndef _REENT_ONLY
+
+int 
+raise (sig)
+     int sig;
+{
+  return _raise_r (_REENT, sig);
+}
+
+_sig_func_ptr
+_DEFUN (signal, (sig, func),
+	int sig _AND
+	_sig_func_ptr func)
+{
+  return _signal_r (_REENT, sig, func);
+}
+
+int 
+_init_signal ()
+{
+  return _init_signal_r (_REENT);
+}
+
+int
+__sigtramp (int sig)
+{
+  return __sigtramp_r (_REENT, sig);
+}
+
+#endif
+
+#endif /* !SIGNAL_PROVIDED */