1 /*
2 * Copyright (c) 2019, 2020, 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.
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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
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23 */
24
25 #include "precompiled.hpp"
26 #include "jvm.h"
27 #include "classfile/javaClasses.inline.hpp"
28 #include "classfile/resolutionErrors.hpp"
29 #include "interpreter/bootstrapInfo.hpp"
30 #include "interpreter/linkResolver.hpp"
31 #include "logging/log.hpp"
32 #include "logging/logStream.hpp"
33 #include "memory/oopFactory.hpp"
34 #include "oops/cpCache.inline.hpp"
35 #include "oops/objArrayOop.inline.hpp"
36 #include "oops/typeArrayOop.inline.hpp"
37 #include "runtime/handles.inline.hpp"
38 #include "runtime/thread.inline.hpp"
39 #include "runtime/vmThread.hpp"
40
41 //------------------------------------------------------------------------------------------------------------------------
42 // Implementation of BootstrapInfo
43
BootstrapInfo(const constantPoolHandle & pool,int bss_index,int indy_index)44 BootstrapInfo::BootstrapInfo(const constantPoolHandle& pool, int bss_index, int indy_index)
45 : _pool(pool),
46 _bss_index(bss_index),
47 _indy_index(indy_index),
48 // derived and eagerly cached:
49 _argc( pool->bootstrap_argument_count_at(bss_index) ),
50 _name( pool->uncached_name_ref_at(bss_index) ),
51 _signature( pool->uncached_signature_ref_at(bss_index) )
52 {
53 _is_resolved = false;
54 assert(pool->tag_at(bss_index).has_bootstrap(), "");
55 assert(indy_index == -1 || pool->invokedynamic_bootstrap_ref_index_at(indy_index) == bss_index, "invalid bootstrap specifier index");
56 }
57
58 // If there is evidence this call site was already linked, set the
59 // existing linkage data into result, or throw previous exception.
60 // Return true if either action is taken, else false.
resolve_previously_linked_invokedynamic(CallInfo & result,TRAPS)61 bool BootstrapInfo::resolve_previously_linked_invokedynamic(CallInfo& result, TRAPS) {
62 assert(_indy_index != -1, "");
63 ConstantPoolCacheEntry* cpce = invokedynamic_cp_cache_entry();
64 if (!cpce->is_f1_null()) {
65 methodHandle method( THREAD, cpce->f1_as_method());
66 Handle appendix( THREAD, cpce->appendix_if_resolved(_pool));
67 result.set_handle(method, appendix, THREAD);
68 Exceptions::wrap_dynamic_exception(/* is_indy */ true, CHECK_false);
69 return true;
70 } else if (cpce->indy_resolution_failed()) {
71 int encoded_index = ResolutionErrorTable::encode_cpcache_index(_indy_index);
72 ConstantPool::throw_resolution_error(_pool, encoded_index, CHECK_false);
73 return true;
74 } else {
75 return false;
76 }
77 }
78
79 // Resolve the bootstrap specifier in 3 steps:
80 // - unpack the BSM by resolving the MH constant
81 // - obtain the NameAndType description for the condy/indy
82 // - prepare the BSM's static arguments
resolve_bsm(TRAPS)83 Handle BootstrapInfo::resolve_bsm(TRAPS) {
84 if (_bsm.not_null()) {
85 return _bsm;
86 }
87
88 bool is_indy = is_method_call();
89 // The tag at the bootstrap method index must be a valid method handle or a method handle in error.
90 // If it is a MethodHandleInError, a resolution error will be thrown which will be wrapped if necessary
91 // with a BootstrapMethodError.
92 assert(_pool->tag_at(bsm_index()).is_method_handle() ||
93 _pool->tag_at(bsm_index()).is_method_handle_in_error(), "MH not present, classfile structural constraint");
94 oop bsm_oop = _pool->resolve_possibly_cached_constant_at(bsm_index(), THREAD);
95 Exceptions::wrap_dynamic_exception(is_indy, CHECK_NH);
96 guarantee(java_lang_invoke_MethodHandle::is_instance(bsm_oop), "classfile must supply a valid BSM");
97 _bsm = Handle(THREAD, bsm_oop);
98
99 // Obtain NameAndType information
100 resolve_bss_name_and_type(THREAD);
101 Exceptions::wrap_dynamic_exception(is_indy, CHECK_NH);
102
103 // Prepare static arguments
104 resolve_args(THREAD);
105 Exceptions::wrap_dynamic_exception(is_indy, CHECK_NH);
106
107 return _bsm;
108 }
109
110 // Resolve metadata from the JVM_Dynamic_info or JVM_InvokeDynamic_info's name and type information.
resolve_bss_name_and_type(TRAPS)111 void BootstrapInfo::resolve_bss_name_and_type(TRAPS) {
112 assert(_bsm.not_null(), "resolve_bsm first");
113 Symbol* name = this->name();
114 Symbol* type = this->signature();
115 _name_arg = java_lang_String::create_from_symbol(name, CHECK);
116 if (type->char_at(0) == '(') {
117 _type_arg = SystemDictionary::find_method_handle_type(type, caller(), CHECK);
118 } else {
119 _type_arg = SystemDictionary::find_java_mirror_for_type(type, caller(), SignatureStream::NCDFError, CHECK);
120 }
121 }
122
123 // Resolve the bootstrap method's static arguments and store the result in _arg_values.
resolve_args(TRAPS)124 void BootstrapInfo::resolve_args(TRAPS) {
125 assert(_bsm.not_null(), "resolve_bsm first");
126
127 // if there are no static arguments, return leaving _arg_values as null
128 if (_argc == 0 && UseBootstrapCallInfo < 2) return;
129
130 bool use_BSCI;
131 switch (UseBootstrapCallInfo) {
132 default: use_BSCI = true; break; // stress mode
133 case 0: use_BSCI = false; break; // stress mode
134 case 1: // normal mode
135 // If we were to support an alternative mode of BSM invocation,
136 // we'd convert to pull mode here if the BSM could be a candidate
137 // for that alternative mode. We can't easily test for things
138 // like varargs here, but we can get away with approximate testing,
139 // since the JDK runtime will make up the difference either way.
140 // For now, exercise the pull-mode path if the BSM is of arity 2,
141 // or if there is a potential condy loop (see below).
142 oop mt_oop = java_lang_invoke_MethodHandle::type(_bsm());
143 use_BSCI = (java_lang_invoke_MethodType::ptype_count(mt_oop) == 2);
144 break;
145 }
146
147 // Here's a reason to use BSCI even if it wasn't requested:
148 // If a condy uses a condy argument, we want to avoid infinite
149 // recursion (condy loops) in the C code. It's OK in Java,
150 // because Java has stack overflow checking, so we punt
151 // potentially cyclic cases from C to Java.
152 if (!use_BSCI && _pool->tag_at(_bss_index).is_dynamic_constant()) {
153 bool found_unresolved_condy = false;
154 for (int i = 0; i < _argc; i++) {
155 int arg_index = _pool->bootstrap_argument_index_at(_bss_index, i);
156 if (_pool->tag_at(arg_index).is_dynamic_constant()) {
157 // potential recursion point condy -> condy
158 bool found_it = false;
159 _pool->find_cached_constant_at(arg_index, found_it, CHECK);
160 if (!found_it) { found_unresolved_condy = true; break; }
161 }
162 }
163 if (found_unresolved_condy)
164 use_BSCI = true;
165 }
166
167 const int SMALL_ARITY = 5;
168 if (use_BSCI && _argc <= SMALL_ARITY && UseBootstrapCallInfo <= 2) {
169 // If there are only a few arguments, and none of them need linking,
170 // push them, instead of asking the JDK runtime to turn around and
171 // pull them, saving a JVM/JDK transition in some simple cases.
172 bool all_resolved = true;
173 for (int i = 0; i < _argc; i++) {
174 bool found_it = false;
175 int arg_index = _pool->bootstrap_argument_index_at(_bss_index, i);
176 _pool->find_cached_constant_at(arg_index, found_it, CHECK);
177 if (!found_it) { all_resolved = false; break; }
178 }
179 if (all_resolved)
180 use_BSCI = false;
181 }
182
183 if (!use_BSCI) {
184 // return {arg...}; resolution of arguments is done immediately, before JDK code is called
185 objArrayOop args_oop = oopFactory::new_objArray(SystemDictionary::Object_klass(), _argc, CHECK);
186 objArrayHandle args(THREAD, args_oop);
187 _pool->copy_bootstrap_arguments_at(_bss_index, 0, _argc, args, 0, true, Handle(), CHECK);
188 oop arg_oop = ((_argc == 1) ? args->obj_at(0) : (oop)NULL);
189 // try to discard the singleton array
190 if (arg_oop != NULL && !arg_oop->is_array()) {
191 // JVM treats arrays and nulls specially in this position,
192 // but other things are just single arguments
193 _arg_values = Handle(THREAD, arg_oop);
194 } else {
195 _arg_values = args;
196 }
197 } else {
198 // return {arg_count, pool_index}; JDK code must pull the arguments as needed
199 typeArrayOop ints_oop = oopFactory::new_typeArray(T_INT, 2, CHECK);
200 ints_oop->int_at_put(0, _argc);
201 ints_oop->int_at_put(1, _bss_index);
202 _arg_values = Handle(THREAD, ints_oop);
203 }
204 }
205
206 // there must be a LinkageError pending; try to save it and then throw
save_and_throw_indy_exc(TRAPS)207 bool BootstrapInfo::save_and_throw_indy_exc(TRAPS) {
208 assert(HAS_PENDING_EXCEPTION, "");
209 assert(_indy_index != -1, "");
210 ConstantPoolCacheEntry* cpce = invokedynamic_cp_cache_entry();
211 int encoded_index = ResolutionErrorTable::encode_cpcache_index(_indy_index);
212 bool recorded_res_status = cpce->save_and_throw_indy_exc(_pool, _bss_index,
213 encoded_index,
214 pool()->tag_at(_bss_index),
215 CHECK_false);
216 return recorded_res_status;
217 }
218
resolve_newly_linked_invokedynamic(CallInfo & result,TRAPS)219 void BootstrapInfo::resolve_newly_linked_invokedynamic(CallInfo& result, TRAPS) {
220 assert(is_resolved(), "");
221 result.set_handle(resolved_method(), resolved_appendix(), CHECK);
222 }
223
print_msg_on(outputStream * st,const char * msg)224 void BootstrapInfo::print_msg_on(outputStream* st, const char* msg) {
225 ResourceMark rm;
226 char what[20];
227 st = st ? st : tty;
228
229 if (_indy_index != -1)
230 sprintf(what, "indy#%d", decode_indy_index());
231 else
232 sprintf(what, "condy");
233 bool have_msg = (msg != NULL && strlen(msg) > 0);
234 st->print_cr("%s%sBootstrap in %s %s@CP[%d] %s:%s%s BSMS[%d] BSM@CP[%d]%s argc=%d%s",
235 (have_msg ? msg : ""), (have_msg ? " " : ""),
236 caller()->name()->as_C_string(),
237 what, // "indy#42" or "condy"
238 _bss_index,
239 _name->as_C_string(),
240 _signature->as_C_string(),
241 (_type_arg.is_null() ? "" : "(resolved)"),
242 bsms_attr_index(),
243 bsm_index(), (_bsm.is_null() ? "" : "(resolved)"),
244 _argc, (_arg_values.is_null() ? "" : "(resolved)"));
245 if (_argc > 0) {
246 char argbuf[80];
247 argbuf[0] = 0;
248 for (int i = 0; i < _argc; i++) {
249 int pos = (int) strlen(argbuf);
250 if (pos + 20 > (int)sizeof(argbuf)) {
251 sprintf(argbuf + pos, "...");
252 break;
253 }
254 if (i > 0) argbuf[pos++] = ',';
255 sprintf(argbuf+pos, "%d", arg_index(i));
256 }
257 st->print_cr(" argument indexes: {%s}", argbuf);
258 }
259 if (_bsm.not_null()) {
260 st->print(" resolved BSM: "); _bsm->print_on(st);
261 }
262
263 // How the array of resolved arguments is printed depends highly
264 // on how BootstrapInfo::resolve_args structures the array based on
265 // the use_BSCI setting.
266 if (_arg_values.not_null()) {
267 // Find the static arguments within the first element of _arg_values.
268 objArrayOop static_args = (objArrayOop)_arg_values();
269 if (!static_args->is_array()) {
270 assert(_argc == 1, "Invalid BSM _arg_values for non-array");
271 st->print(" resolved arg[0]: "); static_args->print_on(st);
272 } else if (static_args->is_objArray()) {
273 int lines = 0;
274 for (int i = 0; i < _argc; i++) {
275 oop x = static_args->obj_at(i);
276 if (x != NULL) {
277 if (++lines > 6) {
278 st->print_cr(" resolved arg[%d]: ...", i);
279 break;
280 }
281 st->print(" resolved arg[%d]: ", i); x->print_on(st);
282 }
283 }
284 } else if (static_args->is_typeArray()) {
285 typeArrayOop tmp_array = (typeArrayOop) static_args;
286 assert(tmp_array->length() == 2, "Invalid BSM _arg_values type array");
287 st->print_cr(" resolved arg[0]: %d", tmp_array->int_at(0));
288 st->print_cr(" resolved arg[1]: %d", tmp_array->int_at(1));
289 }
290 }
291 }
292