hotspot/src/share/vm/classfile/stackMapFrame.hpp
changeset 1 489c9b5090e2
child 5547 f4b087cbb361
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/classfile/stackMapFrame.hpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,226 @@
+/*
+ * 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.
+ *
+ */
+
+// A StackMapFrame represents one frame in the stack map attribute.
+
+enum {
+  FLAG_THIS_UNINIT = 0x01
+};
+
+class StackMapFrame : public ResourceObj {
+ private:
+  int32_t _offset;
+
+  // See comment in StackMapTable about _frame_count about why these
+  // fields are int32_t instead of u2.
+  int32_t _locals_size;  // number of valid type elements in _locals
+  int32_t _stack_size;   // number of valid type elements in _stack
+
+  int32_t _max_locals;
+  int32_t _max_stack;
+
+  u1 _flags;
+  VerificationType* _locals; // local variable type array
+  VerificationType* _stack;  // operand stack type array
+
+  ClassVerifier* _verifier;  // the verifier verifying this method
+
+ public:
+  // constructors
+
+  // This constructor is used by the type checker to allocate frames
+  // in type state, which have _max_locals and _max_stack array elements
+  // in _locals and _stack.
+  StackMapFrame(u2 max_locals, u2 max_stack, ClassVerifier* verifier);
+
+  // This constructor is used to initialize stackmap frames in stackmap table,
+  // which have _locals_size and _stack_size array elements in _locals and _stack.
+  StackMapFrame(int32_t offset,
+                u1 flags,
+                u2 locals_size,
+                u2 stack_size,
+                u2 max_locals,
+                u2 max_stack,
+                VerificationType* locals,
+                VerificationType* stack,
+                ClassVerifier* v) : _offset(offset), _flags(flags),
+                                    _locals_size(locals_size),
+                                    _stack_size(stack_size),
+                                    _max_locals(max_locals),
+                                    _max_stack(max_stack),
+                                    _locals(locals), _stack(stack),
+                                    _verifier(v) { }
+
+  inline void set_offset(int32_t offset)      { _offset = offset; }
+  inline void set_verifier(ClassVerifier* v)  { _verifier = v; }
+  inline void set_flags(u1 flags)             { _flags = flags; }
+  inline void set_locals_size(u2 locals_size) { _locals_size = locals_size; }
+  inline void set_stack_size(u2 stack_size)   { _stack_size = stack_size; }
+  inline void clear_stack()                   { _stack_size = 0; }
+  inline int32_t offset()   const             { return _offset; }
+  inline ClassVerifier* verifier() const      { return _verifier; }
+  inline u1 flags() const                     { return _flags; }
+  inline int32_t locals_size() const          { return _locals_size; }
+  inline VerificationType* locals() const     { return _locals; }
+  inline int32_t stack_size() const           { return _stack_size; }
+  inline VerificationType* stack() const      { return _stack; }
+  inline int32_t max_locals() const           { return _max_locals; }
+  inline int32_t max_stack() const            { return _max_stack; }
+  inline bool flag_this_uninit() const        { return _flags & FLAG_THIS_UNINIT; }
+
+  // Set locals and stack types to bogus
+  inline void reset() {
+    int32_t i;
+    for (i = 0; i < _max_locals; i++) {
+      _locals[i] = VerificationType::bogus_type();
+    }
+    for (i = 0; i < _max_stack; i++) {
+      _stack[i] = VerificationType::bogus_type();
+    }
+  }
+
+  // Return a StackMapFrame with the same local variable array and empty stack.
+  // Stack array is allocate with unused one element.
+  StackMapFrame* frame_in_exception_handler(u1 flags);
+
+  // Set local variable type array based on m's signature.
+  VerificationType set_locals_from_arg(
+    const methodHandle m, VerificationType thisKlass, TRAPS);
+
+  // Search local variable type array and stack type array.
+  // Return true if an uninitialized object is found.
+  bool has_new_object() const;
+
+  // Search local variable type array and stack type array.
+  // Set every element with type of old_object to new_object.
+  void initialize_object(
+    VerificationType old_object, VerificationType new_object);
+
+  // Copy local variable type array in src into this local variable type array.
+  void copy_locals(const StackMapFrame* src);
+
+  // Copy stack type array in src into this stack type array.
+  void copy_stack(const StackMapFrame* src);
+
+  // Return true if this stack map frame is assignable to target.
+  bool is_assignable_to(const StackMapFrame* target, TRAPS) const;
+
+  // Push type into stack type array.
+  inline void push_stack(VerificationType type, TRAPS) {
+    assert(!type.is_check(), "Must be a real type");
+    if (_stack_size >= _max_stack) {
+      verifier()->verify_error(_offset, "Operand stack overflow");
+      return;
+    }
+    _stack[_stack_size++] = type;
+  }
+
+  inline void push_stack_2(
+      VerificationType type1, VerificationType type2, TRAPS) {
+    assert(type1.is_long() || type1.is_double(), "must be long/double");
+    assert(type2.is_long2() || type2.is_double2(), "must be long/double_2");
+    if (_stack_size >= _max_stack - 1) {
+      verifier()->verify_error(_offset, "Operand stack overflow");
+      return;
+    }
+    _stack[_stack_size++] = type1;
+    _stack[_stack_size++] = type2;
+  }
+
+  // Pop and return the top type on stack without verifying.
+  inline VerificationType pop_stack(TRAPS) {
+    if (_stack_size <= 0) {
+      verifier()->verify_error(_offset, "Operand stack underflow");
+      return VerificationType::bogus_type();
+    }
+    // Put bogus type to indicate it's no longer valid.
+    // Added to make it consistent with the other pop_stack method.
+    VerificationType top = _stack[--_stack_size];
+    NOT_PRODUCT( _stack[_stack_size] = VerificationType::bogus_type(); )
+    return top;
+  }
+
+  // Pop and return the top type on stack type array after verifying it
+  // is assignable to type.
+  inline VerificationType pop_stack(VerificationType type, TRAPS) {
+    if (_stack_size != 0) {
+      VerificationType top = _stack[_stack_size - 1];
+      bool subtype = type.is_assignable_from(
+        top, verifier()->current_class(),
+        CHECK_(VerificationType::bogus_type()));
+      if (subtype) {
+        _stack_size --;
+        NOT_PRODUCT( _stack[_stack_size] = VerificationType::bogus_type(); )
+        return top;
+      }
+    }
+    return pop_stack_ex(type, THREAD);
+  }
+
+  inline void pop_stack_2(
+      VerificationType type1, VerificationType type2, TRAPS) {
+    assert(type1.is_long2() || type1.is_double2(), "must be long/double");
+    assert(type2.is_long() || type2.is_double(), "must be long/double_2");
+    if (_stack_size >= 2) {
+      VerificationType top1 = _stack[_stack_size - 1];
+      bool subtype1 = type1.is_assignable_from(
+        top1, verifier()->current_class(), CHECK);
+      VerificationType top2 = _stack[_stack_size - 2];
+      bool subtype2 = type2.is_assignable_from(
+        top2, verifier()->current_class(), CHECK);
+      if (subtype1 && subtype2) {
+        _stack_size -= 2;
+        NOT_PRODUCT( _stack[_stack_size] = VerificationType::bogus_type(); )
+        NOT_PRODUCT( _stack[_stack_size+1] = VerificationType::bogus_type(); )
+        return;
+      }
+    }
+    pop_stack_ex(type1, THREAD);
+    pop_stack_ex(type2, THREAD);
+  }
+
+  // Uncommon case that throws exceptions.
+  VerificationType pop_stack_ex(VerificationType type, TRAPS);
+
+  // Return the type at index in local variable array after verifying
+  // it is assignable to type.
+  VerificationType get_local(int32_t index, VerificationType type, TRAPS);
+  // For long/double.
+  void get_local_2(
+    int32_t index, VerificationType type1, VerificationType type2, TRAPS);
+
+  // Set element at index in local variable array to type.
+  void set_local(int32_t index, VerificationType type, TRAPS);
+  // For long/double.
+  void set_local_2(
+    int32_t index, VerificationType type1, VerificationType type2, TRAPS);
+
+  // Private auxiliary method used only in is_assignable_to(StackMapFrame).
+  // Returns true if src is assignable to target.
+  bool is_assignable_to(
+    VerificationType* src, VerificationType* target, int32_t len, TRAPS) const;
+
+  // Debugging
+  void print() const PRODUCT_RETURN;
+};