Initial revision

From-SVN: r26263

libjava/exception.cc

@@ -0,0 +1,155 @@
+// Functions for Exception Support for Java.
+
+/* Copyright (C) 1998, 1999  Cygnus Solutions
+
+   This file is part of libgcj.
+
+This software is copyrighted work licensed under the terms of the
+Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
+details.  */
+
+#include <config.h>
+
+#include "exception"
+#include <stddef.h>
+
+#include <java/lang/Class.h>
+#include <java/lang/NullPointerException.h>
+#include <cni.h>
+#include <jvm.h>
+
+// eh-common.h needs gansidecl.h.
+#include "gansidecl.h"
+#include "eh-common.h"
+
+typedef struct {
+  __eh_info eh_info;
+  void *value;
+} java_eh_info;
+
+
+/* Language-specific EH info pointer, throw routine, and language/version
+   info routines. All defined in libgcc2. */
+
+extern "C" java_eh_info **__get_eh_info (); 
+extern "C" void __throw () __attribute__ ((__noreturn__));
+extern "C" short __get_eh_table_version (void *table);
+extern "C" short __get_eh_table_language (void *table);
+
+
+extern "C" void * malloc (size_t);
+extern "C" void free (void *);
+
+
+extern "C" void *
+_Jv_type_matcher (java_eh_info *info, void* match_info, 
+		  void *exception_table)
+{
+  if (__get_eh_table_language (exception_table) != EH_LANG_Java)
+    return NULL;
+
+  /* we don't worry about version info yet, there is only one version! */
+  
+  if (match_info != NULL)
+    {
+      // The match_info is either a (java::lang::Class*) or
+      // match_info is one more than a (Utf8Const*).
+      if (sizeof(void*) != sizeof(size_t))
+	abort();
+      size_t mi = (size_t) match_info;
+      if ((mi & 1) != 0)
+	match_info = _Jv_FindClass ((Utf8Const*) (mi - 1), NULL);
+      if (! _Jv_IsInstanceOf ((jobject) info->value, (jclass) match_info))
+	return NULL;
+    }
+
+  return info->value;
+}
+
+/* Compiler hook to return a pointer to java exception object. The value
+   is cleared, so if the exception needs to be rethrown, it should be set 
+   again */
+
+extern "C" void *
+_Jv_exception_info (void)
+{
+  java_eh_info *info = *(__get_eh_info ());
+  void *ptr;
+
+  if (info == NULL)
+    abort ();
+
+  ptr = info->value;
+
+  /* clear the value so another throw is an error */
+  info->value = NULL;
+
+  return ptr;
+}
+
+
+
+/* Allocate an exception info structure for java. Called the first time
+   an exception is thrown. */
+
+extern "C" void
+_Jv_eh_alloc ()
+{
+  /* FIXME: we should use _Jv_AllocBytes here.  However, libgcc2
+     apparently can sometimes free() this value itself.  */
+  java_eh_info *p = (java_eh_info *) malloc (sizeof (java_eh_info));
+  if (p == 0)
+    terminate ();
+
+  p->value = 0;
+  java_eh_info ** info_ptr = __get_eh_info ();
+
+  /* There should NOT be an exception info pointer already. */
+  if (*info_ptr != NULL)
+    abort ();
+
+  *info_ptr = p;
+}
+
+/* Deallocate the current exception info structure. Called at shutdown time. */
+
+extern "C" void
+_Jv_eh_free ()
+{
+  java_eh_info ** info_ptr = __get_eh_info ();
+  if (*info_ptr == NULL)
+    abort ();
+  
+  /* FIXME: ideally we should just let the GC handle this.  */
+  free (*info_ptr);
+  *info_ptr = NULL;
+}
+
+/* Perform a throw, Java style. Throw will unwind through this call, so
+   there better not be any handlers or exception thrown here. */
+
+
+/* Initialize an __eh_info structure with this libraries matching info. */
+
+extern "C" void
+_Jv_setup_eh_info (__eh_info *)
+{
+}
+
+extern "C" void
+_Jv_Throw (void *value)
+{
+  if (value == NULL)
+    value = (void *) new java::lang::NullPointerException ();
+  java_eh_info *ehinfo = *(__get_eh_info ());
+  if (ehinfo == NULL)
+    {
+      _Jv_eh_alloc ();
+      ehinfo = *(__get_eh_info ());
+    }
+  ehinfo->eh_info.match_function = _Jv_type_matcher;
+  ehinfo->eh_info.language = EH_LANG_Java;
+  ehinfo->eh_info.version = 1;
+  ehinfo->value = value;
+  __throw();
+}