--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/classfile/stackMapTable.hpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,161 @@
+/*
+ * Copyright 2003-2006 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code 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 General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+class StackMapReader;
+
+// StackMapTable class is the StackMap table used by type checker
+class StackMapTable : public StackObj {
+ private:
+  // Logically, the _frame_count (as well as many fields in the StackFrame)
+  // should be a u2, but if we defined the variable as that type it will
+  // be difficult to detect/recover from overflow or underflow conditions.
+  // Widening the type and making it signed will help detect these.
+  int32_t              _code_length;
+  int32_t              _frame_count;     // Stackmap frame count
+  StackMapFrame**       _frame_array;
+
+ public:
+  StackMapTable(StackMapReader* reader, StackMapFrame* init_frame,
+                u2 max_locals, u2 max_stack,
+                char* code_data, int code_len, TRAPS);
+
+  inline int32_t get_frame_count() const { return _frame_count; }
+  inline int get_offset(int index) const {
+    return _frame_array[index]->offset();
+  }
+
+  // Match and/or update current_frame to the frame in stackmap table with
+  // specified offset. Return true if the two frames match.
+  bool match_stackmap(
+    StackMapFrame* current_frame, int32_t offset,
+    bool match, bool update, TRAPS) const;
+  // Match and/or update current_frame to the frame in stackmap table with
+  // specified offset and frame index. Return true if the two frames match.
+  bool match_stackmap(
+    StackMapFrame* current_frame, int32_t offset, int32_t frame_index,
+    bool match, bool update, TRAPS) const;
+
+  // Check jump instructions. Make sure there are no uninitialized
+  // instances on backward branch.
+  void check_jump_target(StackMapFrame* frame, int32_t target, TRAPS) const;
+
+  // The following methods are only used inside this class.
+
+  // Returns the frame array index where the frame with offset is stored.
+  int get_index_from_offset(int32_t offset) const;
+
+  // Make sure that there's no uninitialized object exist on backward branch.
+  void check_new_object(
+    const StackMapFrame* frame, int32_t target, TRAPS) const;
+
+  // Debugging
+  void print() const PRODUCT_RETURN;
+};
+
+class StackMapStream : StackObj {
+ private:
+  typeArrayHandle _data;
+  int _index;
+ public:
+  StackMapStream(typeArrayHandle ah)
+    : _data(ah), _index(0) {
+  }
+  u1 get_u1(TRAPS) {
+    if (_data == NULL || _index >= _data->length()) {
+      stackmap_format_error("access beyond the end of attribute", CHECK_0);
+    }
+    return _data->byte_at(_index++);
+  }
+  u2 get_u2(TRAPS) {
+    if (_data == NULL || _index >= _data->length() - 1) {
+      stackmap_format_error("access beyond the end of attribute", CHECK_0);
+    }
+    u2 res = Bytes::get_Java_u2((u1*)_data->byte_at_addr(_index));
+    _index += 2;
+    return res;
+  }
+  bool at_end() {
+    return (_data == NULL) || (_index == _data->length());
+  }
+  static void stackmap_format_error(const char* msg, TRAPS);
+};
+
+class StackMapReader : StackObj {
+ private:
+  // information about the class and method
+  constantPoolHandle  _cp;
+  ClassVerifier* _verifier;
+  StackMapStream* _stream;
+  char* _code_data;
+  int32_t _code_length;
+
+  // information get from the attribute
+  int32_t  _frame_count;       // frame count
+
+  int32_t chop(VerificationType* locals, int32_t length, int32_t chops);
+  VerificationType parse_verification_type(u1* flags, TRAPS);
+  void check_verification_type_array_size(
+      int32_t size, int32_t max_size, TRAPS) {
+    if (size < 0 || size > max_size) {
+      // Since this error could be caused someone rewriting the method
+      // but not knowing to update the stackmap data, we call the the
+      // verifier's error method, which may not throw an exception and
+      // failover to the old verifier instead.
+      _verifier->class_format_error(
+        "StackMapTable format error: bad type array size");
+    }
+  }
+
+  enum {
+    SAME_LOCALS_1_STACK_ITEM_EXTENDED = 247,
+    SAME_EXTENDED = 251,
+    FULL = 255
+  };
+
+ public:
+  // Constructor
+  StackMapReader(ClassVerifier* v, StackMapStream* stream, char* code_data,
+                 int32_t code_len, TRAPS) :
+                 _verifier(v), _stream(stream),
+                 _code_data(code_data), _code_length(code_len) {
+    methodHandle m = v->method();
+    if (m->has_stackmap_table()) {
+      _cp = constantPoolHandle(THREAD, m->constants());
+      _frame_count = _stream->get_u2(CHECK);
+    } else {
+      // There's no stackmap table present. Frame count and size are 0.
+      _frame_count = 0;
+    }
+  }
+
+  inline int32_t get_frame_count() const                { return _frame_count; }
+  StackMapFrame* next(StackMapFrame* pre_frame, bool first,
+                      u2 max_locals, u2 max_stack, TRAPS);
+
+  void check_end(TRAPS) {
+    if (!_stream->at_end()) {
+      StackMapStream::stackmap_format_error("wrong attribute size", CHECK);
+    }
+  }
+};