* Like symtab but rely on ANSI C features.

core/loader/sym.c

@@ -0,0 +1,99 @@
+/*
+ * Copyright (c) 2007, Swedish Institute of Computer Science
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the Institute nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * @(#)$Id: sym.c,v 1.1 2007/04/25 15:33:54 bg- Exp $
+ */
+
+#ifdef __AVR__
+#include <avr/pgmspace.h>
+#endif
+
+#include "loader/sym.h"
+
+#include <string.h>
+
+static union sym_value
+sym_lookup(const char *name, const struct sym_bol *symbols, int nelts)
+{
+  union sym_value ret;
+  int start, middle, end;
+  int r;
+  
+  start = 0;
+  end = nelts - 1;
+
+  while(start <= end) {
+    /* Check middle, divide */
+    middle = (start + end) / 2;
+#ifdef __AVR__
+    PGM_P addr = (PGM_P)pgm_read_word(&symbols[middle].name);
+    r = strcmp_P(name, addr);
+#else
+    r = strcmp(name, symbols[middle].name);
+#endif
+    if(r < 0) {
+      end = middle - 1;
+    } else if(r > 0) {
+      start = middle + 1;
+    } else {
+#ifdef __AVR__
+      ret.func = (sym_func_t)pgm_read_word(&symbols[middle].value);
+      return ret;
+#else
+      return symbols[middle].value;   
+#endif
+    }
+  }
+  ret.obj = NULL;
+  ret.func = NULL;
+  return ret;
+}
+
+/* Lookup a pointer to an ANSI C object. */
+void *
+sym_object(const char *name)
+{
+  union sym_value ret;
+  ret = sym_lookup(name, sym_obj, sym_obj_nelts);
+  if(ret.obj != NULL)
+    return ret.obj;
+
+  /*
+   * If the implementation puts constants into the text segment, this
+   * is where to find them!
+   */
+  ret = sym_lookup(name, sym_func, sym_func_nelts);
+  return ret.obj;
+}
+
+/* Lookup a pointer to an ANSI C function. */
+sym_func_t
+sym_function(const char *name)
+{
+  return sym_lookup(name, sym_func, sym_func_nelts).func;
+}

core/loader/sym.h

@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 2007, Swedish Institute of Computer Science
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the Institute nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * @(#)$Id: sym.h,v 1.1 2007/04/25 15:33:29 bg- Exp $
+ */
+
+#ifndef SYM_H
+#define SYM_H
+
+typedef void (*sym_func_t)();
+
+/*
+ * Even with an explicit cast, it is invalid to convert a function
+ * pointer to an object pointer or a pointer to void, or vice-versa.
+ */
+union sym_value {
+  void *obj;			/* Object pointer */
+  sym_func_t func;		/* or function pointer */
+};
+
+struct sym_bol {
+  const char *name;
+  union sym_value value;
+};
+
+/* Lookup a pointer to an ANSI C object. */
+void *sym_object(const char *name);
+
+/* Lookup a pointer to an ANSI C function. */
+sym_func_t sym_function(const char *name);
+
+extern const int sym_obj_nelts;
+extern const int sym_func_nelts;
+
+extern const struct sym_bol sym_obj[/* sym_obj_nelts */];
+extern const struct sym_bol sym_func[/* sym_func__nelts */];
+
+#endif /* SYM_H */