--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/classfile/genericSignatures.hpp	Thu Oct 11 12:25:42 2012 -0400
@@ -0,0 +1,467 @@
+/*
+ * Copyright (c) 2012, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_CLASSFILE_GENERICSIGNATURES_HPP
+#define SHARE_VM_CLASSFILE_GENERICSIGNATURES_HPP
+
+#include "classfile/symbolTable.hpp"
+#include "memory/allocation.hpp"
+#include "runtime/signature.hpp"
+#include "utilities/growableArray.hpp"
+#include "utilities/resourceHash.hpp"
+
+class stringStream;
+
+namespace generic {
+
+class Identifier;
+class ClassDescriptor;
+class MethodDescriptor;
+
+class TypeParameter; // a formal type parameter declared in generic signatures
+class TypeArgument;  // The "type value" passed to fill parameters in supertypes
+class TypeVariable;  // A usage of a type parameter as a value
+/**
+ * Example:
+ *
+ * <T, V> class Foo extends Bar<String> { int m(V v) {} }
+ * ^^^^^^                       ^^^^^^          ^^
+ * type parameters            type argument    type variable
+ *
+ * Note that a type variable could be passed as an argument too:
+ * <T, V> class Foo extends Bar<T> { int m(V v) {} }
+ *                             ^^^
+ *                             type argument's value is a type variable
+ */
+
+
+class Type;
+class ClassType;
+class ArrayType;
+class PrimitiveType;
+class Context;
+class DescriptorCache;
+
+class DescriptorStream;
+
+class Identifier : public ResourceObj {
+ private:
+  Symbol* _sym;
+  int _begin;
+  int _end;
+
+ public:
+  Identifier(Symbol* sym, int begin, int end) :
+    _sym(sym), _begin(begin), _end(end) {}
+
+  bool equals(Identifier* other);
+  bool equals(Symbol* sym);
+
+#ifndef PRODUCT
+  void print_on(outputStream* str) const;
+#endif // ndef PRODUCT
+};
+
+class Descriptor : public ResourceObj {
+ protected:
+  GrowableArray<TypeParameter*> _type_parameters;
+  ClassDescriptor* _outer_class;
+
+  Descriptor(GrowableArray<TypeParameter*>& params,
+    ClassDescriptor* outer)
+    : _type_parameters(params), _outer_class(outer) {}
+
+ public:
+
+  ClassDescriptor* outer_class() { return _outer_class; }
+  void set_outer_class(ClassDescriptor* sig) { _outer_class = sig; }
+
+  virtual ClassDescriptor* as_class_signature() { return NULL; }
+  virtual MethodDescriptor* as_method_signature() { return NULL; }
+
+  bool is_class_signature() { return as_class_signature() != NULL; }
+  bool is_method_signature() { return as_method_signature() != NULL; }
+
+  GrowableArray<TypeParameter*>& type_parameters() {
+    return _type_parameters;
+  }
+
+  TypeParameter* find_type_parameter(Identifier* id, int* param_depth);
+
+  virtual void bind_variables_to_parameters() = 0;
+
+#ifndef PRODUCT
+  virtual void print_on(outputStream* str) const = 0;
+#endif
+};
+
+class ClassDescriptor : public Descriptor {
+ private:
+  ClassType* _super;
+  GrowableArray<ClassType*> _interfaces;
+  MethodDescriptor* _outer_method;
+
+  ClassDescriptor(GrowableArray<TypeParameter*>& ftp, ClassType* scs,
+      GrowableArray<ClassType*>& sis, ClassDescriptor* outer_class = NULL,
+      MethodDescriptor* outer_method = NULL)
+        : Descriptor(ftp, outer_class), _super(scs), _interfaces(sis),
+          _outer_method(outer_method) {}
+
+  static u2 get_outer_class_index(InstanceKlass* k, TRAPS);
+  static ClassDescriptor* parse_generic_signature(Klass* k, Symbol* original_name, TRAPS);
+
+ public:
+
+  virtual ClassDescriptor* as_class_signature() { return this; }
+
+  MethodDescriptor* outer_method() { return _outer_method; }
+  void set_outer_method(MethodDescriptor* m) { _outer_method = m; }
+
+  ClassType* super() { return _super; }
+  ClassType* interface_desc(Symbol* sym);
+
+  static ClassDescriptor* parse_generic_signature(Klass* k, TRAPS);
+  static ClassDescriptor* parse_generic_signature(Symbol* sym);
+
+  // For use in superclass chains in positions where this is no generic info
+  static ClassDescriptor* placeholder(InstanceKlass* klass);
+
+#ifndef PRODUCT
+  void print_on(outputStream* str) const;
+#endif
+
+  ClassDescriptor* canonicalize(Context* ctx);
+
+  // Linking sets the position index in any contained TypeVariable type
+  // to correspond to the location of that identifier in the formal type
+  // parameters.
+  void bind_variables_to_parameters();
+};
+
+class MethodDescriptor : public Descriptor {
+ private:
+  GrowableArray<Type*> _parameters;
+  Type* _return_type;
+  GrowableArray<Type*> _throws;
+
+  MethodDescriptor(GrowableArray<TypeParameter*>& ftp, ClassDescriptor* outer,
+      GrowableArray<Type*>& sigs, Type* rt, GrowableArray<Type*>& throws)
+      : Descriptor(ftp, outer), _parameters(sigs), _return_type(rt),
+        _throws(throws) {}
+
+ public:
+
+  static MethodDescriptor* parse_generic_signature(Method* m, ClassDescriptor* outer);
+  static MethodDescriptor* parse_generic_signature(Symbol* sym, ClassDescriptor* outer);
+
+  MethodDescriptor* as_method_signature() { return this; }
+
+  // Performs generic analysis on the method parameters to determine
+  // if both methods refer to the same argument types.
+  bool covariant_match(MethodDescriptor* other, Context* ctx);
+
+  // Returns a new method descriptor with all generic variables
+  // removed and replaced with whatever is indicated using the Context.
+  MethodDescriptor* canonicalize(Context* ctx);
+
+  void bind_variables_to_parameters();
+
+#ifndef PRODUCT
+  TempNewSymbol reify_signature(Context* ctx, TRAPS);
+  void print_on(outputStream* str) const;
+#endif
+};
+
+class TypeParameter : public ResourceObj {
+ private:
+  Identifier* _identifier;
+  ClassType* _class_bound;
+  GrowableArray<ClassType*> _interface_bounds;
+
+  // The position is the ordinal location of the parameter within the
+  // formal parameter list (excluding outer classes).  It is only set for
+  // formal type parameters that are associated with a class -- method
+  // type parameters are left as -1.  When resolving a generic variable to
+  // find the actual type, this index is used to access the generic type
+  // argument in the provided context object.
+  int _position; // Assigned during variable linking
+
+  TypeParameter(Identifier* id, ClassType* class_bound,
+    GrowableArray<ClassType*>& interface_bounds) :
+      _identifier(id), _class_bound(class_bound),
+      _interface_bounds(interface_bounds), _position(-1) {}
+
+ public:
+  static TypeParameter* parse_generic_signature(DescriptorStream* str);
+
+  ClassType* bound();
+  int position() { return _position; }
+
+  void bind_variables_to_parameters(Descriptor* sig, int position);
+  Identifier* identifier() { return _identifier; }
+
+  Type* resolve(Context* ctx, int inner_depth, int ctx_depth);
+  TypeParameter* canonicalize(Context* ctx, int ctx_depth);
+
+#ifndef PRODUCT
+  void print_on(outputStream* str) const;
+#endif
+};
+
+class Type : public ResourceObj {
+ public:
+  static Type* parse_generic_signature(DescriptorStream* str);
+
+  virtual ClassType* as_class() { return NULL; }
+  virtual TypeVariable* as_variable() { return NULL; }
+  virtual ArrayType* as_array() { return NULL; }
+  virtual PrimitiveType* as_primitive() { return NULL; }
+
+  virtual bool covariant_match(Type* gt, Context* ctx) = 0;
+  virtual Type* canonicalize(Context* ctx, int ctx_depth) = 0;
+
+  virtual void bind_variables_to_parameters(Descriptor* sig) = 0;
+
+#ifndef PRODUCT
+  virtual void reify_signature(stringStream* ss, Context* ctx) = 0;
+  virtual void print_on(outputStream* str) const = 0;
+#endif
+};
+
+class ClassType : public Type {
+  friend class ClassDescriptor;
+ protected:
+  Identifier* _identifier;
+  GrowableArray<TypeArgument*> _type_arguments;
+  ClassType* _outer_class;
+
+  ClassType(Identifier* identifier,
+      GrowableArray<TypeArgument*>& args,
+      ClassType* outer)
+      : _identifier(identifier), _type_arguments(args), _outer_class(outer) {}
+
+  // Returns true if there are inner classes to read
+  static Identifier* parse_generic_signature_simple(
+      GrowableArray<TypeArgument*>* args,
+      bool* has_inner, DescriptorStream* str);
+
+  static ClassType* parse_generic_signature(ClassType* outer,
+      DescriptorStream* str);
+  static ClassType* from_symbol(Symbol* sym);
+
+ public:
+  ClassType* as_class() { return this; }
+
+  static ClassType* parse_generic_signature(DescriptorStream* str);
+  static ClassType* java_lang_Object();
+
+  Identifier* identifier() { return _identifier; }
+  int type_arguments_length() { return _type_arguments.length(); }
+  TypeArgument* type_argument_at(int i);
+
+  virtual ClassType* outer_class() { return _outer_class; }
+
+  bool covariant_match(Type* gt, Context* ctx);
+  ClassType* canonicalize(Context* ctx, int context_depth);
+
+  void bind_variables_to_parameters(Descriptor* sig);
+
+#ifndef PRODUCT
+  void reify_signature(stringStream* ss, Context* ctx);
+  void print_on(outputStream* str) const;
+#endif
+};
+
+class TypeVariable : public Type {
+ private:
+  Identifier* _id;
+  TypeParameter* _parameter; // assigned during linking
+
+  // how many steps "out" from inner classes, -1 if method
+  int _inner_depth;
+
+  TypeVariable(Identifier* id)
+      : _id(id), _parameter(NULL), _inner_depth(0) {}
+
+ public:
+  TypeVariable* as_variable() { return this; }
+
+  static TypeVariable* parse_generic_signature(DescriptorStream* str);
+
+  Identifier* identifier() { return _id; }
+  TypeParameter* parameter() { return _parameter; }
+  int inner_depth() { return _inner_depth; }
+
+  void bind_variables_to_parameters(Descriptor* sig);
+
+  Type* resolve(Context* ctx, int ctx_depth);
+  bool covariant_match(Type* gt, Context* ctx);
+  Type* canonicalize(Context* ctx, int ctx_depth);
+
+#ifndef PRODUCT
+  void reify_signature(stringStream* ss, Context* ctx);
+  void print_on(outputStream* str) const;
+#endif
+};
+
+class ArrayType : public Type {
+ private:
+  Type* _base;
+
+  ArrayType(Type* base) : _base(base) {}
+
+ public:
+  ArrayType* as_array() { return this; }
+
+  static ArrayType* parse_generic_signature(DescriptorStream* str);
+
+  bool covariant_match(Type* gt, Context* ctx);
+  ArrayType* canonicalize(Context* ctx, int ctx_depth);
+
+  void bind_variables_to_parameters(Descriptor* sig);
+
+#ifndef PRODUCT
+  void reify_signature(stringStream* ss, Context* ctx);
+  void print_on(outputStream* str) const;
+#endif
+};
+
+class PrimitiveType : public Type {
+  friend class Type;
+ private:
+  char _type; // includes V for void
+
+  PrimitiveType(char& type) : _type(type) {}
+
+ public:
+  PrimitiveType* as_primitive() { return this; }
+
+  bool covariant_match(Type* gt, Context* ctx);
+  PrimitiveType* canonicalize(Context* ctx, int ctx_depth);
+
+  void bind_variables_to_parameters(Descriptor* sig);
+
+#ifndef PRODUCT
+  void reify_signature(stringStream* ss, Context* ctx);
+  void print_on(outputStream* str) const;
+#endif
+};
+
+class TypeArgument : public ResourceObj {
+ private:
+  Type* _lower_bound;
+  Type* _upper_bound; // may be null or == _lower_bound
+
+  TypeArgument(Type* lower_bound, Type* upper_bound)
+      : _lower_bound(lower_bound), _upper_bound(upper_bound) {}
+
+ public:
+
+  static TypeArgument* parse_generic_signature(DescriptorStream* str);
+
+  Type* lower_bound() { return _lower_bound; }
+  Type* upper_bound() { return _upper_bound; }
+
+  void bind_variables_to_parameters(Descriptor* sig);
+  TypeArgument* canonicalize(Context* ctx, int ctx_depth);
+
+  bool covariant_match(TypeArgument* a, Context* ctx);
+
+#ifndef PRODUCT
+  void print_on(outputStream* str) const;
+#endif
+};
+
+
+class Context : public ResourceObj {
+ private:
+  DescriptorCache* _cache;
+  GrowableArray<ClassType*> _type_arguments;
+
+  void reset_to_mark(int size);
+
+ public:
+  // When this object goes out of scope or 'destroy' is
+  // called, then the application of the type to the
+  // context is wound-back (unless it's been deactivated).
+  class Mark : public StackObj {
+   private:
+    mutable Context* _context;
+    int _marked_size;
+
+    bool is_active() const { return _context != NULL; }
+    void deactivate() const { _context = NULL; }
+
+   public:
+    Mark() : _context(NULL), _marked_size(0) {}
+    Mark(Context* ctx, int sz) : _context(ctx), _marked_size(sz) {}
+    Mark(const Mark& m) : _context(m._context), _marked_size(m._marked_size) {
+      m.deactivate(); // Ownership is transferred
+    }
+
+    Mark& operator=(const Mark& cm) {
+      destroy();
+      _context = cm._context;
+      _marked_size = cm._marked_size;
+      cm.deactivate();
+      return *this;
+    }
+
+    void destroy();
+    ~Mark() { destroy(); }
+  };
+
+  Context(DescriptorCache* cache) : _cache(cache) {}
+
+  Mark mark() { return Mark(this, _type_arguments.length()); }
+  void apply_type_arguments(InstanceKlass* current, InstanceKlass* super,TRAPS);
+
+  ClassType* at_depth(int i) const;
+
+#ifndef PRODUCT
+  void print_on(outputStream* str) const;
+#endif
+};
+
+/**
+ * Contains a cache of descriptors for classes and methods so they can be
+ * looked-up instead of reparsing each time they are needed.
+ */
+class DescriptorCache : public ResourceObj {
+ private:
+  ResourceHashtable<InstanceKlass*, ClassDescriptor*> _class_descriptors;
+  ResourceHashtable<Method*, MethodDescriptor*> _method_descriptors;
+
+ public:
+  ClassDescriptor* descriptor_for(InstanceKlass* ikh, TRAPS);
+
+  MethodDescriptor* descriptor_for(Method* mh, ClassDescriptor* cd, TRAPS);
+  // Class descriptor derived from method holder
+  MethodDescriptor* descriptor_for(Method* mh, TRAPS);
+};
+
+} // namespace generic
+
+#endif // SHARE_VM_CLASSFILE_GENERICSIGNATURES_HPP
+