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src/share/vm/classfile/stackMapTable.hpp@98cb887364d3 (annotated)

src/share/vm/classfile/stackMapTable.hpp

Fri, 27 Feb 2009 13:27:09 -0800

author

twisti

date

Fri, 27 Feb 2009 13:27:09 -0800

changeset 1040

98cb887364d3

parent 435

a61af66fc99e

child 1907

c18cbe5936b8

permissions

-rw-r--r--

6810672: Comment typos
Summary: I have collected some typos I have found while looking at the code.
Reviewed-by: kvn, never

duke@435	1	/*
duke@435	2	* Copyright 2003-2006 Sun Microsystems, Inc. All Rights Reserved.
duke@435	3	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435	4	*
duke@435	5	* This code is free software; you can redistribute it and/or modify it
duke@435	6	* under the terms of the GNU General Public License version 2 only, as
duke@435	7	* published by the Free Software Foundation.
duke@435	8	*
duke@435	9	* This code is distributed in the hope that it will be useful, but WITHOUT
duke@435	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435	12	* version 2 for more details (a copy is included in the LICENSE file that
duke@435	13	* accompanied this code).
duke@435	14	*
duke@435	15	* You should have received a copy of the GNU General Public License version
duke@435	16	* 2 along with this work; if not, write to the Free Software Foundation,
duke@435	17	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435	18	*
duke@435	19	* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
duke@435	20	* CA 95054 USA or visit www.sun.com if you need additional information or
duke@435	21	* have any questions.
duke@435	22	*
duke@435	23	*/
duke@435	24
duke@435	25	class StackMapReader;
duke@435	26
duke@435	27	// StackMapTable class is the StackMap table used by type checker
duke@435	28	class StackMapTable : public StackObj {
duke@435	29	private:
duke@435	30	// Logically, the _frame_count (as well as many fields in the StackFrame)
duke@435	31	// should be a u2, but if we defined the variable as that type it will
duke@435	32	// be difficult to detect/recover from overflow or underflow conditions.
duke@435	33	// Widening the type and making it signed will help detect these.
duke@435	34	int32_t _code_length;
duke@435	35	int32_t _frame_count; // Stackmap frame count
duke@435	36	StackMapFrame** _frame_array;
duke@435	37
duke@435	38	public:
duke@435	39	StackMapTable(StackMapReader* reader, StackMapFrame* init_frame,
duke@435	40	u2 max_locals, u2 max_stack,
duke@435	41	char* code_data, int code_len, TRAPS);
duke@435	42
duke@435	43	inline int32_t get_frame_count() const { return _frame_count; }
duke@435	44	inline int get_offset(int index) const {
duke@435	45	return _frame_array[index]->offset();
duke@435	46	}
duke@435	47
duke@435	48	// Match and/or update current_frame to the frame in stackmap table with
duke@435	49	// specified offset. Return true if the two frames match.
duke@435	50	bool match_stackmap(
duke@435	51	StackMapFrame* current_frame, int32_t offset,
duke@435	52	bool match, bool update, TRAPS) const;
duke@435	53	// Match and/or update current_frame to the frame in stackmap table with
duke@435	54	// specified offset and frame index. Return true if the two frames match.
duke@435	55	bool match_stackmap(
duke@435	56	StackMapFrame* current_frame, int32_t offset, int32_t frame_index,
duke@435	57	bool match, bool update, TRAPS) const;
duke@435	58
duke@435	59	// Check jump instructions. Make sure there are no uninitialized
duke@435	60	// instances on backward branch.
duke@435	61	void check_jump_target(StackMapFrame* frame, int32_t target, TRAPS) const;
duke@435	62
duke@435	63	// The following methods are only used inside this class.
duke@435	64
duke@435	65	// Returns the frame array index where the frame with offset is stored.
duke@435	66	int get_index_from_offset(int32_t offset) const;
duke@435	67
duke@435	68	// Make sure that there's no uninitialized object exist on backward branch.
duke@435	69	void check_new_object(
duke@435	70	const StackMapFrame* frame, int32_t target, TRAPS) const;
duke@435	71
duke@435	72	// Debugging
duke@435	73	void print() const PRODUCT_RETURN;
duke@435	74	};
duke@435	75
duke@435	76	class StackMapStream : StackObj {
duke@435	77	private:
duke@435	78	typeArrayHandle _data;
duke@435	79	int _index;
duke@435	80	public:
duke@435	81	StackMapStream(typeArrayHandle ah)
duke@435	82	: _data(ah), _index(0) {
duke@435	83	}
duke@435	84	u1 get_u1(TRAPS) {
duke@435	85	if (_data == NULL || _index >= _data->length()) {
duke@435	86	stackmap_format_error("access beyond the end of attribute", CHECK_0);
duke@435	87	}
duke@435	88	return _data->byte_at(_index++);
duke@435	89	}
duke@435	90	u2 get_u2(TRAPS) {
duke@435	91	if (_data == NULL || _index >= _data->length() - 1) {
duke@435	92	stackmap_format_error("access beyond the end of attribute", CHECK_0);
duke@435	93	}
duke@435	94	u2 res = Bytes::get_Java_u2((u1*)_data->byte_at_addr(_index));
duke@435	95	_index += 2;
duke@435	96	return res;
duke@435	97	}
duke@435	98	bool at_end() {
duke@435	99	return (_data == NULL) || (_index == _data->length());
duke@435	100	}
duke@435	101	static void stackmap_format_error(const char* msg, TRAPS);
duke@435	102	};
duke@435	103
duke@435	104	class StackMapReader : StackObj {
duke@435	105	private:
duke@435	106	// information about the class and method
duke@435	107	constantPoolHandle _cp;
duke@435	108	ClassVerifier* _verifier;
duke@435	109	StackMapStream* _stream;
duke@435	110	char* _code_data;
duke@435	111	int32_t _code_length;
duke@435	112
duke@435	113	// information get from the attribute
duke@435	114	int32_t _frame_count; // frame count
duke@435	115
duke@435	116	int32_t chop(VerificationType* locals, int32_t length, int32_t chops);
duke@435	117	VerificationType parse_verification_type(u1* flags, TRAPS);
duke@435	118	void check_verification_type_array_size(
duke@435	119	int32_t size, int32_t max_size, TRAPS) {
duke@435	120	if (size < 0 || size > max_size) {
duke@435	121	// Since this error could be caused someone rewriting the method
duke@435	122	// but not knowing to update the stackmap data, we call the the
duke@435	123	// verifier's error method, which may not throw an exception and
duke@435	124	// failover to the old verifier instead.
duke@435	125	_verifier->class_format_error(
duke@435	126	"StackMapTable format error: bad type array size");
duke@435	127	}
duke@435	128	}
duke@435	129
duke@435	130	enum {
duke@435	131	SAME_LOCALS_1_STACK_ITEM_EXTENDED = 247,
duke@435	132	SAME_EXTENDED = 251,
duke@435	133	FULL = 255
duke@435	134	};
duke@435	135
duke@435	136	public:
duke@435	137	// Constructor
duke@435	138	StackMapReader(ClassVerifier* v, StackMapStream* stream, char* code_data,
duke@435	139	int32_t code_len, TRAPS) :
duke@435	140	_verifier(v), _stream(stream),
duke@435	141	_code_data(code_data), _code_length(code_len) {
duke@435	142	methodHandle m = v->method();
duke@435	143	if (m->has_stackmap_table()) {
duke@435	144	_cp = constantPoolHandle(THREAD, m->constants());
duke@435	145	_frame_count = _stream->get_u2(CHECK);
duke@435	146	} else {
duke@435	147	// There's no stackmap table present. Frame count and size are 0.
duke@435	148	_frame_count = 0;
duke@435	149	}
duke@435	150	}
duke@435	151
duke@435	152	inline int32_t get_frame_count() const { return _frame_count; }
duke@435	153	StackMapFrame* next(StackMapFrame* pre_frame, bool first,
duke@435	154	u2 max_locals, u2 max_stack, TRAPS);
duke@435	155
duke@435	156	void check_end(TRAPS) {
duke@435	157	if (!_stream->at_end()) {
duke@435	158	StackMapStream::stackmap_format_error("wrong attribute size", CHECK);
duke@435	159	}
duke@435	160	}
duke@435	161	};