1 /*
2 * Copyright (c) 2013, Red Hat Inc.
3 * Copyright (c) 1997, 2012, Oracle and/or its affiliates.
4 * All rights reserved.
5 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
6 *
7 * This code is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2 only, as
9 * published by the Free Software Foundation.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 *
25 */
26
27 #include "precompiled.hpp"
28 #include "asm/macroAssembler.hpp"
29 #include "interpreter/interpreter.hpp"
30 #include "interpreter/interpreterRuntime.hpp"
31 #include "memory/allocation.inline.hpp"
32 #include "prims/methodHandles.hpp"
33
34 #define __ _masm->
35
36 #ifdef PRODUCT
37 #define BLOCK_COMMENT(str) /* nothing */
38 #else
39 #define BLOCK_COMMENT(str) __ block_comment(str)
40 #endif
41
42 #define BIND(label) bind(label); BLOCK_COMMENT(#label ":")
43
44 void MethodHandles::load_klass_from_Class(MacroAssembler* _masm, Register klass_reg) {
45 if (VerifyMethodHandles)
46 verify_klass(_masm, klass_reg, SystemDictionary::WK_KLASS_ENUM_NAME(java_lang_Class),
47 "MH argument is a Class");
48 __ ldr(klass_reg, Address(klass_reg, java_lang_Class::klass_offset_in_bytes()));
49 }
50
51 #ifdef ASSERT
52 static int check_nonzero(const char* xname, int x) {
53 assert(x != 0, err_msg("%s should be nonzero", xname));
54 return x;
55 }
56 #define NONZERO(x) check_nonzero(#x, x)
57 #else //ASSERT
58 #define NONZERO(x) (x)
59 #endif //PRODUCT
60
61 #ifdef ASSERT
62 void MethodHandles::verify_klass(MacroAssembler* _masm,
63 Register obj, SystemDictionary::WKID klass_id,
64 const char* error_message) {
65 Klass** klass_addr = SystemDictionary::well_known_klass_addr(klass_id);
66 KlassHandle klass = SystemDictionary::well_known_klass(klass_id);
67 Register temp = rscratch2;
68 Register temp2 = rscratch1; // used by MacroAssembler::cmpptr
69 Label L_ok, L_bad;
70 BLOCK_COMMENT("verify_klass {");
71 __ verify_oop(obj);
72 __ cbz(obj, L_bad);
73 __ push(RegSet::of(temp, temp2), sp);
74 __ load_klass(temp, obj);
75 __ cmpptr(temp, ExternalAddress((address) klass_addr));
76 __ br(Assembler::EQ, L_ok);
77 intptr_t super_check_offset = klass->super_check_offset();
78 __ ldr(temp, Address(temp, super_check_offset));
79 __ cmpptr(temp, ExternalAddress((address) klass_addr));
80 __ br(Assembler::EQ, L_ok);
81 __ pop(RegSet::of(temp, temp2), sp);
82 __ bind(L_bad);
83 __ stop(error_message);
84 __ BIND(L_ok);
85 __ pop(RegSet::of(temp, temp2), sp);
86 BLOCK_COMMENT("} verify_klass");
87 }
88
89 void MethodHandles::verify_ref_kind(MacroAssembler* _masm, int ref_kind, Register member_reg, Register temp) { }
90
91 #endif //ASSERT
92
93 void MethodHandles::jump_from_method_handle(MacroAssembler* _masm, Register method, Register temp,
94 bool for_compiler_entry) {
95 assert(method == rmethod, "interpreter calling convention");
96 Label L_no_such_method;
97 __ cbz(rmethod, L_no_such_method);
98 __ verify_method_ptr(method);
99
100 if (!for_compiler_entry && JvmtiExport::can_post_interpreter_events()) {
101 Label run_compiled_code;
102 // JVMTI events, such as single-stepping, are implemented partly by avoiding running
103 // compiled code in threads for which the event is enabled. Check here for
104 // interp_only_mode if these events CAN be enabled.
105
106 __ ldrw(rscratch1, Address(rthread, JavaThread::interp_only_mode_offset()));
107 __ cbzw(rscratch1, run_compiled_code);
108 __ ldr(rscratch1, Address(method, Method::interpreter_entry_offset()));
109 __ br(rscratch1);
110 __ BIND(run_compiled_code);
111 }
112
113 const ByteSize entry_offset = for_compiler_entry ? Method::from_compiled_offset() :
114 Method::from_interpreted_offset();
115 __ ldr(rscratch1,Address(method, entry_offset));
116 __ br(rscratch1);
117 __ bind(L_no_such_method);
118 __ far_jump(RuntimeAddress(StubRoutines::throw_AbstractMethodError_entry()));
119 }
120
121 void MethodHandles::jump_to_lambda_form(MacroAssembler* _masm,
122 Register recv, Register method_temp,
123 Register temp2,
124 bool for_compiler_entry) {
125 BLOCK_COMMENT("jump_to_lambda_form {");
126 // This is the initial entry point of a lazy method handle.
127 // After type checking, it picks up the invoker from the LambdaForm.
128 assert_different_registers(recv, method_temp, temp2);
129 assert(recv != noreg, "required register");
130 assert(method_temp == rmethod, "required register for loading method");
131
132 //NOT_PRODUCT({ FlagSetting fs(TraceMethodHandles, true); trace_method_handle(_masm, "LZMH"); });
133
134 // Load the invoker, as MH -> MH.form -> LF.vmentry
135 __ verify_oop(recv);
136 __ load_heap_oop(method_temp, Address(recv, NONZERO(java_lang_invoke_MethodHandle::form_offset_in_bytes())));
137 __ verify_oop(method_temp);
138 __ load_heap_oop(method_temp, Address(method_temp, NONZERO(java_lang_invoke_LambdaForm::vmentry_offset_in_bytes())));
139 __ verify_oop(method_temp);
140 // the following assumes that a Method* is normally compressed in the vmtarget field:
141 __ ldr(method_temp, Address(method_temp, NONZERO(java_lang_invoke_MemberName::vmtarget_offset_in_bytes())));
142
143 if (VerifyMethodHandles && !for_compiler_entry) {
144 // make sure recv is already on stack
145 __ ldr(temp2, Address(method_temp, Method::const_offset()));
146 __ load_sized_value(temp2,
147 Address(temp2, ConstMethod::size_of_parameters_offset()),
148 sizeof(u2), /*is_signed*/ false);
149 // assert(sizeof(u2) == sizeof(Method::_size_of_parameters), "");
150 Label L;
151 __ ldr(rscratch1, __ argument_address(temp2, -1));
152 __ cmp(recv, rscratch1);
153 __ br(Assembler::EQ, L);
154 __ ldr(r0, __ argument_address(temp2, -1));
155 __ hlt(0);
156 __ BIND(L);
157 }
158
159 jump_from_method_handle(_masm, method_temp, temp2, for_compiler_entry);
160 BLOCK_COMMENT("} jump_to_lambda_form");
161 }
162
163 // Code generation
164 address MethodHandles::generate_method_handle_interpreter_entry(MacroAssembler* _masm,
165 vmIntrinsics::ID iid) {
166 const bool not_for_compiler_entry = false; // this is the interpreter entry
167 assert(is_signature_polymorphic(iid), "expected invoke iid");
168 if (iid == vmIntrinsics::_invokeGeneric ||
169 iid == vmIntrinsics::_compiledLambdaForm) {
170 // Perhaps surprisingly, the symbolic references visible to Java are not directly used.
171 // They are linked to Java-generated adapters via MethodHandleNatives.linkMethod.
172 // They all allow an appendix argument.
173 __ hlt(0); // empty stubs make SG sick
174 return NULL;
175 }
176
177 // r13: sender SP (must preserve; see prepare_to_jump_from_interpreted)
178 // rmethod: Method*
179 // r3: argument locator (parameter slot count, added to rsp)
180 // r1: used as temp to hold mh or receiver
181 // r0, r11: garbage temps, blown away
182 Register argp = r3; // argument list ptr, live on error paths
183 Register temp = r0;
184 Register mh = r1; // MH receiver; dies quickly and is recycled
185
186 // here's where control starts out:
187 __ align(CodeEntryAlignment);
188 address entry_point = __ pc();
189
190 if (VerifyMethodHandles) {
191 Label L;
192 BLOCK_COMMENT("verify_intrinsic_id {");
193 __ ldrb(rscratch1, Address(rmethod, Method::intrinsic_id_offset_in_bytes()));
194 __ cmp(rscratch1, (int) iid);
195 __ br(Assembler::EQ, L);
196 if (iid == vmIntrinsics::_linkToVirtual ||
197 iid == vmIntrinsics::_linkToSpecial) {
198 // could do this for all kinds, but would explode assembly code size
199 trace_method_handle(_masm, "bad Method*::intrinsic_id");
200 }
201 __ hlt(0);
202 __ bind(L);
203 BLOCK_COMMENT("} verify_intrinsic_id");
204 }
205
206 // First task: Find out how big the argument list is.
207 Address r3_first_arg_addr;
208 int ref_kind = signature_polymorphic_intrinsic_ref_kind(iid);
209 assert(ref_kind != 0 || iid == vmIntrinsics::_invokeBasic, "must be _invokeBasic or a linkTo intrinsic");
210 if (ref_kind == 0 || MethodHandles::ref_kind_has_receiver(ref_kind)) {
211 __ ldr(argp, Address(rmethod, Method::const_offset()));
212 __ load_sized_value(argp,
213 Address(argp, ConstMethod::size_of_parameters_offset()),
214 sizeof(u2), /*is_signed*/ false);
215 // assert(sizeof(u2) == sizeof(Method::_size_of_parameters), "");
216 r3_first_arg_addr = __ argument_address(argp, -1);
217 } else {
218 DEBUG_ONLY(argp = noreg);
219 }
220
221 if (!is_signature_polymorphic_static(iid)) {
222 __ ldr(mh, r3_first_arg_addr);
223 DEBUG_ONLY(argp = noreg);
224 }
225
226 // r3_first_arg_addr is live!
227
228 trace_method_handle_interpreter_entry(_masm, iid);
229 if (iid == vmIntrinsics::_invokeBasic) {
230 generate_method_handle_dispatch(_masm, iid, mh, noreg, not_for_compiler_entry);
231
232 } else {
233 // Adjust argument list by popping the trailing MemberName argument.
234 Register recv = noreg;
235 if (MethodHandles::ref_kind_has_receiver(ref_kind)) {
236 // Load the receiver (not the MH; the actual MemberName's receiver) up from the interpreter stack.
237 __ ldr(recv = r2, r3_first_arg_addr);
238 }
239 DEBUG_ONLY(argp = noreg);
240 Register rmember = rmethod; // MemberName ptr; incoming method ptr is dead now
241 __ pop(rmember); // extract last argument
242 generate_method_handle_dispatch(_masm, iid, recv, rmember, not_for_compiler_entry);
243 }
244
245 return entry_point;
246 }
247
248
249 void MethodHandles::generate_method_handle_dispatch(MacroAssembler* _masm,
250 vmIntrinsics::ID iid,
251 Register receiver_reg,
252 Register member_reg,
253 bool for_compiler_entry) {
254 assert(is_signature_polymorphic(iid), "expected invoke iid");
255 // temps used in this code are not used in *either* compiled or interpreted calling sequences
256 Register temp1 = r10;
257 Register temp2 = r11;
258 Register temp3 = r14; // r13 is live by this point: it contains the sender SP
259 if (for_compiler_entry) {
260 assert(receiver_reg == (iid == vmIntrinsics::_linkToStatic ? noreg : j_rarg0), "only valid assignment");
261 assert_different_registers(temp1, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5, j_rarg6, j_rarg7);
262 assert_different_registers(temp2, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5, j_rarg6, j_rarg7);
263 assert_different_registers(temp3, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5, j_rarg6, j_rarg7);
264 }
265
266 assert_different_registers(temp1, temp2, temp3, receiver_reg);
267 assert_different_registers(temp1, temp2, temp3, member_reg);
268
269 if (iid == vmIntrinsics::_invokeBasic) {
270 // indirect through MH.form.vmentry.vmtarget
271 jump_to_lambda_form(_masm, receiver_reg, rmethod, temp1, for_compiler_entry);
272
273 } else {
274 // The method is a member invoker used by direct method handles.
275 if (VerifyMethodHandles) {
276 // make sure the trailing argument really is a MemberName (caller responsibility)
277 verify_klass(_masm, member_reg, SystemDictionary::WK_KLASS_ENUM_NAME(java_lang_invoke_MemberName),
278 "MemberName required for invokeVirtual etc.");
279 }
280
281 Address member_clazz( member_reg, NONZERO(java_lang_invoke_MemberName::clazz_offset_in_bytes()));
282 Address member_vmindex( member_reg, NONZERO(java_lang_invoke_MemberName::vmindex_offset_in_bytes()));
283 Address member_vmtarget( member_reg, NONZERO(java_lang_invoke_MemberName::vmtarget_offset_in_bytes()));
284
285 Register temp1_recv_klass = temp1;
286 if (iid != vmIntrinsics::_linkToStatic) {
287 __ verify_oop(receiver_reg);
288 if (iid == vmIntrinsics::_linkToSpecial) {
289 // Don't actually load the klass; just null-check the receiver.
290 __ null_check(receiver_reg);
291 } else {
292 // load receiver klass itself
293 __ null_check(receiver_reg, oopDesc::klass_offset_in_bytes());
294 __ load_klass(temp1_recv_klass, receiver_reg);
295 __ verify_klass_ptr(temp1_recv_klass);
296 }
297 BLOCK_COMMENT("check_receiver {");
298 // The receiver for the MemberName must be in receiver_reg.
299 // Check the receiver against the MemberName.clazz
300 if (VerifyMethodHandles && iid == vmIntrinsics::_linkToSpecial) {
301 // Did not load it above...
302 __ load_klass(temp1_recv_klass, receiver_reg);
303 __ verify_klass_ptr(temp1_recv_klass);
304 }
305 if (VerifyMethodHandles && iid != vmIntrinsics::_linkToInterface) {
306 Label L_ok;
307 Register temp2_defc = temp2;
308 __ load_heap_oop(temp2_defc, member_clazz);
309 load_klass_from_Class(_masm, temp2_defc);
310 __ verify_klass_ptr(temp2_defc);
311 __ check_klass_subtype(temp1_recv_klass, temp2_defc, temp3, L_ok);
312 // If we get here, the type check failed!
313 __ hlt(0);
314 // __ STOP("receiver class disagrees with MemberName.clazz");
315 __ bind(L_ok);
316 }
317 BLOCK_COMMENT("} check_receiver");
318 }
319 if (iid == vmIntrinsics::_linkToSpecial ||
320 iid == vmIntrinsics::_linkToStatic) {
321 DEBUG_ONLY(temp1_recv_klass = noreg); // these guys didn't load the recv_klass
322 }
323
324 // Live registers at this point:
325 // member_reg - MemberName that was the trailing argument
326 // temp1_recv_klass - klass of stacked receiver, if needed
327 // r13 - interpreter linkage (if interpreted) ??? FIXME
328 // r1 ... r0 - compiler arguments (if compiled)
329
330 Label L_incompatible_class_change_error;
331 switch (iid) {
332 case vmIntrinsics::_linkToSpecial:
333 if (VerifyMethodHandles) {
334 verify_ref_kind(_masm, JVM_REF_invokeSpecial, member_reg, temp3);
335 }
336 __ ldr(rmethod, member_vmtarget);
337 break;
338
339 case vmIntrinsics::_linkToStatic:
340 if (VerifyMethodHandles) {
341 verify_ref_kind(_masm, JVM_REF_invokeStatic, member_reg, temp3);
342 }
343 __ ldr(rmethod, member_vmtarget);
344 break;
345
346 case vmIntrinsics::_linkToVirtual:
347 {
348 // same as TemplateTable::invokevirtual,
349 // minus the CP setup and profiling:
350
351 if (VerifyMethodHandles) {
352 verify_ref_kind(_masm, JVM_REF_invokeVirtual, member_reg, temp3);
353 }
354
355 // pick out the vtable index from the MemberName, and then we can discard it:
356 Register temp2_index = temp2;
357 __ ldr(temp2_index, member_vmindex);
358
359 if (VerifyMethodHandles) {
360 Label L_index_ok;
361 __ cmpw(temp2_index, 0U);
362 __ br(Assembler::GE, L_index_ok);
363 __ hlt(0);
364 __ BIND(L_index_ok);
365 }
366
367 // Note: The verifier invariants allow us to ignore MemberName.clazz and vmtarget
368 // at this point. And VerifyMethodHandles has already checked clazz, if needed.
369
370 // get target Method* & entry point
371 __ lookup_virtual_method(temp1_recv_klass, temp2_index, rmethod);
372 break;
373 }
374
375 case vmIntrinsics::_linkToInterface:
376 {
377 // same as TemplateTable::invokeinterface
378 // (minus the CP setup and profiling, with different argument motion)
379 if (VerifyMethodHandles) {
380 verify_ref_kind(_masm, JVM_REF_invokeInterface, member_reg, temp3);
381 }
382
383 Register temp3_intf = temp3;
384 __ load_heap_oop(temp3_intf, member_clazz);
385 load_klass_from_Class(_masm, temp3_intf);
386 __ verify_klass_ptr(temp3_intf);
387
388 Register rindex = rmethod;
389 __ ldr(rindex, member_vmindex);
390 if (VerifyMethodHandles) {
391 Label L;
392 __ cmpw(rindex, 0U);
393 __ br(Assembler::GE, L);
394 __ hlt(0);
395 __ bind(L);
396 }
397
398 // given intf, index, and recv klass, dispatch to the implementation method
399 __ lookup_interface_method(temp1_recv_klass, temp3_intf,
400 // note: next two args must be the same:
401 rindex, rmethod,
402 temp2,
403 L_incompatible_class_change_error);
404 break;
405 }
406
407 default:
408 fatal(err_msg_res("unexpected intrinsic %d: %s", iid, vmIntrinsics::name_at(iid)));
409 break;
410 }
411
412 // live at this point: rmethod, r13 (if interpreted)
413
414 // After figuring out which concrete method to call, jump into it.
415 // Note that this works in the interpreter with no data motion.
416 // But the compiled version will require that r2_recv be shifted out.
417 __ verify_method_ptr(rmethod);
418 jump_from_method_handle(_masm, rmethod, temp1, for_compiler_entry);
419 if (iid == vmIntrinsics::_linkToInterface) {
420 __ bind(L_incompatible_class_change_error);
421 __ far_jump(RuntimeAddress(StubRoutines::throw_IncompatibleClassChangeError_entry()));
422 }
423 }
424 }
425
426 #ifndef PRODUCT
427 void trace_method_handle_stub(const char* adaptername,
428 oop mh,
429 intptr_t* saved_regs,
430 intptr_t* entry_sp) { }
431
432 // The stub wraps the arguments in a struct on the stack to avoid
433 // dealing with the different calling conventions for passing 6
434 // arguments.
435 struct MethodHandleStubArguments {
436 const char* adaptername;
437 oopDesc* mh;
438 intptr_t* saved_regs;
439 intptr_t* entry_sp;
440 };
441 void trace_method_handle_stub_wrapper(MethodHandleStubArguments* args) { }
442
443 void MethodHandles::trace_method_handle(MacroAssembler* _masm, const char* adaptername) { }
444 #endif //PRODUCT