1 /*
  2  * Copyright (c) 1997, 2021, Oracle and/or its affiliates. All rights reserved.
  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  4  *
  5  * This code is free software; you can redistribute it and/or modify it
  6  * under the terms of the GNU General Public License version 2 only, as
  7  * published by the Free Software Foundation.
  8  *
  9  * This code is distributed in the hope that it will be useful, but WITHOUT
 10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 12  * version 2 for more details (a copy is included in the LICENSE file that
 13  * accompanied this code).
 14  *
 15  * You should have received a copy of the GNU General Public License version
 16  * 2 along with this work; if not, write to the Free Software Foundation,
 17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 18  *
 19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 20  * or visit www.oracle.com if you need additional information or have any
 21  * questions.
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 23  */
 24 
 25 #ifndef SHARE_INTERPRETER_BYTECODE_HPP
 26 #define SHARE_INTERPRETER_BYTECODE_HPP
 27 
 28 #include "interpreter/bytecodes.hpp"
 29 #include "memory/allocation.hpp"
 30 #include "oops/method.hpp"
 31 #include "utilities/align.hpp"
 32 #include "utilities/bytes.hpp"
 33 
 34 class ciBytecodeStream;
 35 
 36 // The base class for different kinds of bytecode abstractions.
 37 // Provides the primitive operations to manipulate code relative
 38 // to the bcp.
 39 
 40 class Bytecode: public StackObj {
 41  protected:
 42   const address   _bcp;
 43   const Bytecodes::Code _code;
 44 
 45   // Address computation
 46   address addr_at            (int offset)        const     { return (address)_bcp + offset; }
 47   u_char byte_at(int offset) const               { return *addr_at(offset); }
 48   address aligned_addr_at    (int offset)        const     { return align_up(addr_at(offset), jintSize); }
 49 
 50   // Word access:
 51   int     get_Java_u2_at     (int offset)        const     { return Bytes::get_Java_u2(addr_at(offset)); }
 52   int     get_Java_u4_at     (int offset)        const     { return Bytes::get_Java_u4(addr_at(offset)); }
 53   int     get_aligned_Java_u4_at(int offset)     const     { return Bytes::get_Java_u4(aligned_addr_at(offset)); }
 54   int     get_native_u2_at   (int offset)        const     { return Bytes::get_native_u2(addr_at(offset)); }
 55   int     get_native_u4_at   (int offset)        const     { return Bytes::get_native_u4(addr_at(offset)); }
 56 
 57  public:
 58   Bytecode(Method* method, address bcp): _bcp(bcp), _code(Bytecodes::code_at(method, addr_at(0))) {
 59     assert(method != NULL, "this form requires a valid Method*");
 60   }
 61   // Defined in ciStreams.hpp
 62   inline Bytecode(const ciBytecodeStream* stream, address bcp = NULL);
 63 
 64   // Attributes
 65   address bcp() const                            { return _bcp; }
 66   int instruction_size() const                   { return Bytecodes::length_for_code_at(_code, bcp()); }
 67 
 68   Bytecodes::Code code() const                   { return _code; }
 69   Bytecodes::Code java_code() const              { return Bytecodes::java_code(code()); }
 70   Bytecodes::Code invoke_code() const            { return (code() == Bytecodes::_invokehandle) ? code() : java_code(); }
 71 
 72   // Static functions for parsing bytecodes in place.
 73   int get_index_u1(Bytecodes::Code bc) const {
 74     assert_same_format_as(bc); assert_index_size(1, bc);
 75     return *(jubyte*)addr_at(1);
 76   }
 77   int get_index_u2(Bytecodes::Code bc, bool is_wide = false) const {
 78     assert_same_format_as(bc, is_wide); assert_index_size(2, bc, is_wide);
 79     address p = addr_at(is_wide ? 2 : 1);
 80     if (can_use_native_byte_order(bc, is_wide)) {
 81       return Bytes::get_native_u2(p);
 82     } else {
 83       return Bytes::get_Java_u2(p);
 84     }
 85   }
 86   int get_index_u1_cpcache(Bytecodes::Code bc) const {
 87     assert_same_format_as(bc); assert_index_size(1, bc);
 88     return *(jubyte*)addr_at(1) + ConstantPool::CPCACHE_INDEX_TAG;
 89   }
 90   int get_index_u2_cpcache(Bytecodes::Code bc) const {
 91     assert_same_format_as(bc); assert_index_size(2, bc); assert_native_index(bc);
 92     return Bytes::get_native_u2(addr_at(1)) + ConstantPool::CPCACHE_INDEX_TAG;
 93   }
 94   int get_index_u4(Bytecodes::Code bc) const {
 95     assert_same_format_as(bc); assert_index_size(4, bc);
 96     assert(can_use_native_byte_order(bc), "");
 97     return Bytes::get_native_u4(addr_at(1));
 98   }
 99   bool has_index_u4(Bytecodes::Code bc) const {
100     return bc == Bytecodes::_invokedynamic;
101   }
102 
103   int get_offset_s2(Bytecodes::Code bc) const {
104     assert_same_format_as(bc); assert_offset_size(2, bc);
105     return (jshort) Bytes::get_Java_u2(addr_at(1));
106   }
107   int get_offset_s4(Bytecodes::Code bc) const {
108     assert_same_format_as(bc); assert_offset_size(4, bc);
109     return (jint) Bytes::get_Java_u4(addr_at(1));
110   }
111 
112   int get_constant_u1(int offset, Bytecodes::Code bc) const {
113     assert_same_format_as(bc); assert_constant_size(1, offset, bc);
114     return *(jbyte*)addr_at(offset);
115   }
116   int get_constant_u2(int offset, Bytecodes::Code bc, bool is_wide = false) const {
117     assert_same_format_as(bc, is_wide); assert_constant_size(2, offset, bc, is_wide);
118     return (jshort) Bytes::get_Java_u2(addr_at(offset));
119   }
120 
121   // These are used locally and also from bytecode streams.
122   void assert_same_format_as(Bytecodes::Code testbc, bool is_wide = false) const NOT_DEBUG_RETURN;
123   static void assert_index_size(int required_size, Bytecodes::Code bc, bool is_wide = false) NOT_DEBUG_RETURN;
124   static void assert_offset_size(int required_size, Bytecodes::Code bc, bool is_wide = false) NOT_DEBUG_RETURN;
125   static void assert_constant_size(int required_size, int where, Bytecodes::Code bc, bool is_wide = false) NOT_DEBUG_RETURN;
126   static void assert_native_index(Bytecodes::Code bc, bool is_wide = false) NOT_DEBUG_RETURN;
127   static bool can_use_native_byte_order(Bytecodes::Code bc, bool is_wide = false) {
128     return (!Endian::is_Java_byte_ordering_different() || Bytecodes::native_byte_order(bc /*, is_wide*/));
129   }
130 };
131 
132 
133 // Abstractions for lookupswitch bytecode
134 class LookupswitchPair {
135  private:
136   const address _bcp;
137 
138   address addr_at            (int offset)        const     { return _bcp + offset; }
139   int     get_Java_u4_at     (int offset)        const     { return Bytes::get_Java_u4(addr_at(offset)); }
140 
141  public:
142   LookupswitchPair(address bcp): _bcp(bcp) {}
143   int  match() const                             { return get_Java_u4_at(0 * jintSize); }
144   int  offset() const                            { return get_Java_u4_at(1 * jintSize); }
145 };
146 
147 
148 class Bytecode_lookupswitch: public Bytecode {
149  public:
150   Bytecode_lookupswitch(Method* method, address bcp): Bytecode(method, bcp) { verify(); }
151   // Defined in ciStreams.hpp
152   inline Bytecode_lookupswitch(const ciBytecodeStream* stream);
153   void verify() const PRODUCT_RETURN;
154 
155   // Attributes
156   int  default_offset() const                    { return get_aligned_Java_u4_at(1 + 0*jintSize); }
157   int  number_of_pairs() const                   { return get_aligned_Java_u4_at(1 + 1*jintSize); }
158   LookupswitchPair pair_at(int i) const          {
159     assert(0 <= i && i < number_of_pairs(), "pair index out of bounds");
160     return LookupswitchPair(aligned_addr_at(1 + (1 + i)*2*jintSize));
161   }
162 };
163 
164 class Bytecode_tableswitch: public Bytecode {
165  public:
166   Bytecode_tableswitch(Method* method, address bcp): Bytecode(method, bcp) { verify(); }
167   // Defined in ciStreams.hpp
168   inline Bytecode_tableswitch(const ciBytecodeStream* stream);
169   void verify() const PRODUCT_RETURN;
170 
171   // Attributes
172   int  default_offset() const                    { return get_aligned_Java_u4_at(1 + 0*jintSize); }
173   int  low_key() const                           { return get_aligned_Java_u4_at(1 + 1*jintSize); }
174   int  high_key() const                          { return get_aligned_Java_u4_at(1 + 2*jintSize); }
175   int  dest_offset_at(int i) const;
176   int  length()                                  { return high_key()-low_key()+1; }
177 };
178 
179 // Common code for decoding invokes and field references.
180 
181 class Bytecode_member_ref: public Bytecode {
182  protected:
183   const Method* _method;                          // method containing the bytecode
184 
185   Bytecode_member_ref(const methodHandle& method, int bci)  : Bytecode(method(), method()->bcp_from(bci)), _method(method()) {}
186 
187   const Method* method() const                 { return _method; }
188   ConstantPool* constants() const              { return _method->constants(); }
189   ConstantPoolCache* cpcache() const           { return _method->constants()->cache(); }
190   ConstantPoolCacheEntry* cpcache_entry() const;
191 
192  public:
193   int          index() const;                    // cache index (loaded from instruction)
194   int          pool_index() const;               // constant pool index
195   Symbol*      klass() const;                    // returns the klass of the method or field
196   Symbol*      name() const;                     // returns the name of the method or field
197   Symbol*      signature() const;                // returns the signature of the method or field
198 
199   BasicType    result_type() const;              // returns the result type of the getfield or invoke
200 };
201 
202 // Abstraction for invoke_{virtual, static, interface, special, dynamic, handle}
203 
204 class Bytecode_invoke: public Bytecode_member_ref {
205  protected:
206   // Constructor that skips verification
207   Bytecode_invoke(const methodHandle& method, int bci, bool unused)  : Bytecode_member_ref(method, bci) {}
208 
209  public:
210   Bytecode_invoke(const methodHandle& method, int bci)  : Bytecode_member_ref(method, bci) { verify(); }
211   void verify() const;
212 
213   // Attributes
214   Method* static_target(TRAPS);                  // "specified" method   (from constant pool)
215 
216   // Testers
217   bool is_invokeinterface() const                { return invoke_code() == Bytecodes::_invokeinterface; }
218   bool is_invokevirtual() const                  { return invoke_code() == Bytecodes::_invokevirtual; }
219   bool is_invokestatic() const                   { return invoke_code() == Bytecodes::_invokestatic; }
220   bool is_invokespecial() const                  { return invoke_code() == Bytecodes::_invokespecial; }
221   bool is_invokedynamic() const                  { return invoke_code() == Bytecodes::_invokedynamic; }
222   bool is_invokehandle() const                   { return invoke_code() == Bytecodes::_invokehandle; }
223 
224   bool has_receiver() const                      { return !is_invokestatic() && !is_invokedynamic(); }
225 
226   bool is_valid() const                          { return is_invokeinterface() ||
227                                                           is_invokevirtual()   ||
228                                                           is_invokestatic()    ||
229                                                           is_invokespecial()   ||
230                                                           is_invokedynamic()   ||
231                                                           is_invokehandle(); }
232 
233   bool has_appendix();
234 
235   int size_of_parameters() const;
236 
237  private:
238   // Helper to skip verification.   Used is_valid() to check if the result is really an invoke
239   inline friend Bytecode_invoke Bytecode_invoke_check(const methodHandle& method, int bci);
240 };
241 
242 inline Bytecode_invoke Bytecode_invoke_check(const methodHandle& method, int bci) {
243   return Bytecode_invoke(method, bci, false);
244 }
245 
246 
247 // Abstraction for all field accesses (put/get field/static)
248 class Bytecode_field: public Bytecode_member_ref {
249  public:
250   Bytecode_field(const methodHandle& method, int bci)  : Bytecode_member_ref(method, bci) { verify(); }
251 
252   // Testers
253   bool is_getfield() const                       { return java_code() == Bytecodes::_getfield; }
254   bool is_putfield() const                       { return java_code() == Bytecodes::_putfield; }
255   bool is_getstatic() const                      { return java_code() == Bytecodes::_getstatic; }
256   bool is_putstatic() const                      { return java_code() == Bytecodes::_putstatic; }
257   bool is_withfield() const                      { return java_code() == Bytecodes::_withfield; }
258 
259   bool is_getter() const                         { return is_getfield()  || is_getstatic(); }
260   bool is_static() const                         { return is_getstatic() || is_putstatic(); }
261 
262   bool is_valid() const                          { return is_getfield()   ||
263                                                           is_putfield()   ||
264                                                           is_getstatic()  ||
265                                                           is_putstatic()  ||
266                                                           is_withfield(); }
267   void verify() const;
268 };
269 
270 // Abstraction for checkcast
271 class Bytecode_checkcast: public Bytecode {
272  public:
273   Bytecode_checkcast(Method* method, address bcp): Bytecode(method, bcp) { verify(); }
274   void verify() const { assert(Bytecodes::java_code(code()) == Bytecodes::_checkcast, "check checkcast"); }
275 
276   // Returns index
277   long index() const   { return get_index_u2(Bytecodes::_checkcast); };
278 };
279 
280 // Abstraction for instanceof
281 class Bytecode_instanceof: public Bytecode {
282  public:
283   Bytecode_instanceof(Method* method, address bcp): Bytecode(method, bcp) { verify(); }
284   void verify() const { assert(code() == Bytecodes::_instanceof, "check instanceof"); }
285 
286   // Returns index
287   long index() const   { return get_index_u2(Bytecodes::_instanceof); };
288 };
289 
290 class Bytecode_new: public Bytecode {
291  public:
292   Bytecode_new(Method* method, address bcp): Bytecode(method, bcp) { verify(); }
293   void verify() const { assert(java_code() == Bytecodes::_new, "check new"); }
294 
295   // Returns index
296   long index() const   { return get_index_u2(Bytecodes::_new); };
297 };
298 
299 class Bytecode_aconst_init: public Bytecode {
300  public:
301   Bytecode_aconst_init(Method* method, address bcp): Bytecode(method, bcp) { verify(); }
302   void verify() const { assert(java_code() == Bytecodes::_aconst_init, "check aconst_init"); }
303 
304   // Returns index
305   long index() const   { return get_index_u2(Bytecodes::_aconst_init); };
306 };
307 
308 class Bytecode_multianewarray: public Bytecode {
309  public:
310   Bytecode_multianewarray(Method* method, address bcp): Bytecode(method, bcp) { verify(); }
311   void verify() const { assert(java_code() == Bytecodes::_multianewarray, "check new"); }
312 
313   // Returns index
314   long index() const   { return get_index_u2(Bytecodes::_multianewarray); };
315 };
316 
317 class Bytecode_anewarray: public Bytecode {
318  public:
319   Bytecode_anewarray(Method* method, address bcp): Bytecode(method, bcp) { verify(); }
320   void verify() const { assert(java_code() == Bytecodes::_anewarray, "check anewarray"); }
321 
322   // Returns index
323   long index() const   { return get_index_u2(Bytecodes::_anewarray); };
324 };
325 
326 // Abstraction for ldc, ldc_w and ldc2_w
327 class Bytecode_loadconstant: public Bytecode {
328  private:
329   const Method* _method;
330 
331   int raw_index() const;
332 
333  public:
334   Bytecode_loadconstant(const methodHandle& method, int bci): Bytecode(method(), method->bcp_from(bci)), _method(method()) { verify(); }
335 
336   void verify() const {
337     assert(_method != NULL, "must supply method");
338     Bytecodes::Code stdc = Bytecodes::java_code(code());
339     assert(stdc == Bytecodes::_ldc ||
340            stdc == Bytecodes::_ldc_w ||
341            stdc == Bytecodes::_ldc2_w, "load constant");
342   }
343 
344   // Only non-standard bytecodes (fast_aldc) have reference cache indexes.
345   bool has_cache_index() const { return code() >= Bytecodes::number_of_java_codes; }
346 
347   int pool_index() const;               // index into constant pool
348   int cache_index() const {             // index into reference cache (or -1 if none)
349     return has_cache_index() ? raw_index() : -1;
350   }
351 
352   BasicType result_type() const;        // returns the result type of the ldc
353 
354   oop resolve_constant(TRAPS) const;
355 };
356 
357 #endif // SHARE_INTERPRETER_BYTECODE_HPP