Infrastructure: Split the files into subdirectories.

[mLib] / utils / exc.c

diff --git a/utils/exc.c b/utils/exc.c
new file mode 100644 (file)
index 0000000..9cc0306
--- /dev/null
+++ b/utils/exc.c
@@ -0,0 +1,136 @@
+/* -*-c-*-
+ *
+ * Structured exception handling in C
+ *
+ * (c) 1998 Straylight/Edgeware
+ */
+
+/*----- Licensing notice --------------------------------------------------*
+ *
+ * This file is part of the mLib utilities library.
+ *
+ * mLib is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * mLib is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with mLib; if not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+#include <stdarg.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+#include "exc.h"
+
+/*----- Global variables --------------------------------------------------*/
+
+__exc_hnd *__exc_list = 0;
+
+/*----- Functions ---------------------------------------------------------*/
+
+/* --- @duff@ --- *
+ *
+ * Arguments:  @exc_extype type@ = type of duff exception
+ *             @exc_exval val@ = extra data supplied
+ *
+ * Returns:    Doesn't
+ *
+ * Use:                Default handler when everything goes wrong.
+ */
+
+static void duff(exc_extype type, exc_exval val)
+{
+  fprintf(stderr, "fatal error: uncaught exception (type = %lx)\n", type);
+  abort();
+}
+
+/* --- @duffproc@ --- *
+ *
+ * Current handler when there are no more exceptions left.
+ */
+
+static exc__uncaught duffproc = duff;
+
+/* --- @exc_uncaught@ --- *
+ *
+ * Arguments:  @void (*proc)(exc_extype type, exc_exval val) = new handler
+ *
+ * Returns:    Pointer to the old handler value.
+ *
+ * Use:                Sets the handler for uncaught exceptions.
+ */
+
+exc__uncaught exc_uncaught(exc__uncaught proc)
+{
+  exc__uncaught p = duffproc;
+  if (proc)
+    duffproc = proc;
+  return (p);
+}
+
+/* --- @__exc_throw@ --- *
+ *
+ * Arguments:  @exc_extype type@ = type of exception to throw
+ *
+ * Returns:    Doesn't
+ *
+ * Use:                NOT FOR USER CONSUMPTION.  Reads an appropriate exception
+ *             value and throws an exception.
+ */
+
+void __exc_throw(exc_extype type, ...)
+{
+  va_list ap;
+  exc_exval v;
+
+  va_start(ap, type);
+  switch (type & 0xC0) {
+    case EXC_NOVAL:
+      v.i = 0;
+      break;
+    case EXC_INTVAL:
+      v.i = va_arg(ap, int);
+      break;
+    case EXC_PTRVAL:
+      v.p = va_arg(ap, void *);
+      break;
+    case EXC_STRVAL:
+      v.s = va_arg(ap, char *);
+      break;
+  }
+  va_end(ap);
+  __exc_rethrow(type, v);
+}
+
+/* --- @__exc_rethrow@ --- *
+ *
+ * Arguments:  @exc_extype type@ = type of exception to throw
+ *             @exc_exval val@ = value of exception to throw
+ *
+ * Returns:    Doesn't
+ *
+ * Use:                NOT FOR USER CONSUMPTION.  Does the donkey-work of raising
+ *             an exception.
+ */
+
+void __exc_rethrow(exc_extype type, exc_exval val)
+{
+  __exc_hnd *p = __exc_list;
+  if (!p)
+    duffproc(type, val);
+  p->type = type;
+  p->val = val;
+  __exc_list = p->next;
+  longjmp(p->buf, type);
+}
+
+/*----- That's all, folks -------------------------------------------------*/