154a1a02bf
Use script and some manual fixup to fix directores names in include guards. Reviewed-by: lfoltan, eosterlund, kbarrett
102 lines
3.8 KiB
C++
102 lines
3.8 KiB
C++
/*
|
|
* Copyright (c) 2015, 2019, 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_UTILITIES_FAKERTTISUPPORT_HPP
|
|
#define SHARE_UTILITIES_FAKERTTISUPPORT_HPP
|
|
|
|
#include "utilities/globalDefinitions.hpp"
|
|
#include "utilities/debug.hpp"
|
|
|
|
// Provides support for checked downcasts in a hierarchy of classes.
|
|
// The base class provides a member of this type, specialized on that
|
|
// base class and an associated tag type. Tags are small non-negative
|
|
// integer values uniquely associated with distinct classes in the
|
|
// hierarchy. A tag type is often an enum type.
|
|
//
|
|
// The concrete class specifies the concrete tag.
|
|
//
|
|
// The tag set specifies the set of classes in the derivation
|
|
// sequence. Classes in the derivation sequence add their associated
|
|
// tag during construction. Given the tag associated with a class, an
|
|
// object is an instance of that class if the tag is included in the
|
|
// object's set of recorded tags.
|
|
//
|
|
// A tag T is present in a tag set if the T'th bit of the tag set is
|
|
// one.
|
|
//
|
|
// Note: The representation of a tag set being uintx sets an upper
|
|
// bound on the size of a class hierarchy this utility can be used
|
|
// with.
|
|
template<typename T, typename TagType>
|
|
class FakeRttiSupport {
|
|
friend class VMStructs;
|
|
public:
|
|
// Construct with the indicated concrete tag, and include the
|
|
// concrete tag in the associated tag set.
|
|
explicit FakeRttiSupport(TagType concrete_tag) :
|
|
_tag_set(tag_bit(concrete_tag)), _concrete_tag(concrete_tag) { }
|
|
|
|
// Construct with the indicated concrete tag and tag set.
|
|
// Note: This constructor is public only to allow clients to set up
|
|
// "unusual" (or perhaps buggy) fake RTTI configurations.
|
|
FakeRttiSupport(TagType concrete_tag, uintx tag_set) :
|
|
_tag_set(tag_set), _concrete_tag(validate_tag(concrete_tag)) { }
|
|
|
|
// Get the concrete tag.
|
|
TagType concrete_tag() const { return _concrete_tag; }
|
|
|
|
// Test whether tag is in the tag set.
|
|
bool has_tag(TagType tag) const {
|
|
return (_tag_set & tag_bit(tag)) != 0;
|
|
}
|
|
|
|
// Return a new support object which is the same as this, except tag
|
|
// has been added to the tag set. The tag must not already be
|
|
// present in the tag set.
|
|
FakeRttiSupport add_tag(TagType tag) const {
|
|
uintx tbit = tag_bit(tag);
|
|
assert((_tag_set & tbit) == 0,
|
|
"Tag " UINTX_FORMAT " is already present in tag set: " UINTX_FORMAT,
|
|
(uintx)tag, _tag_set);
|
|
return FakeRttiSupport(_concrete_tag, _tag_set | tbit);
|
|
}
|
|
|
|
private:
|
|
uintx _tag_set;
|
|
TagType _concrete_tag;
|
|
|
|
static uintx tag_bit(TagType tag) {
|
|
return ((uintx)1) << validate_tag(tag);
|
|
}
|
|
|
|
static TagType validate_tag(TagType tag) {
|
|
assert(0 <= tag, "Tag " INTX_FORMAT " is negative", (intx)tag);
|
|
assert(tag < BitsPerWord,
|
|
"Tag " UINTX_FORMAT " is too large", (uintx)tag);
|
|
return tag;
|
|
}
|
|
};
|
|
|
|
#endif // SHARE_UTILITIES_FAKERTTISUPPORT_HPP
|