Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1 | // Copyright 2015 the V8 project authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | #include "src/debug/debug-evaluate.h" |
| 6 | |
| 7 | #include "src/accessors.h" |
| 8 | #include "src/contexts.h" |
| 9 | #include "src/debug/debug.h" |
| 10 | #include "src/debug/debug-frames.h" |
| 11 | #include "src/debug/debug-scopes.h" |
| 12 | #include "src/frames-inl.h" |
| 13 | #include "src/isolate-inl.h" |
| 14 | |
| 15 | namespace v8 { |
| 16 | namespace internal { |
| 17 | |
| 18 | static inline bool IsDebugContext(Isolate* isolate, Context* context) { |
| 19 | return context->native_context() == *isolate->debug()->debug_context(); |
| 20 | } |
| 21 | |
| 22 | |
| 23 | MaybeHandle<Object> DebugEvaluate::Global( |
| 24 | Isolate* isolate, Handle<String> source, bool disable_break, |
| 25 | Handle<HeapObject> context_extension) { |
| 26 | // Handle the processing of break. |
| 27 | DisableBreak disable_break_scope(isolate->debug(), disable_break); |
| 28 | |
| 29 | // Enter the top context from before the debugger was invoked. |
| 30 | SaveContext save(isolate); |
| 31 | SaveContext* top = &save; |
| 32 | while (top != NULL && IsDebugContext(isolate, *top->context())) { |
| 33 | top = top->prev(); |
| 34 | } |
| 35 | if (top != NULL) isolate->set_context(*top->context()); |
| 36 | |
| 37 | // Get the native context now set to the top context from before the |
| 38 | // debugger was invoked. |
| 39 | Handle<Context> context = isolate->native_context(); |
| 40 | Handle<JSObject> receiver(context->global_proxy()); |
| 41 | Handle<SharedFunctionInfo> outer_info(context->closure()->shared(), isolate); |
| 42 | return Evaluate(isolate, outer_info, context, context_extension, receiver, |
| 43 | source); |
| 44 | } |
| 45 | |
| 46 | |
| 47 | MaybeHandle<Object> DebugEvaluate::Local(Isolate* isolate, |
| 48 | StackFrame::Id frame_id, |
| 49 | int inlined_jsframe_index, |
| 50 | Handle<String> source, |
| 51 | bool disable_break, |
| 52 | Handle<HeapObject> context_extension) { |
| 53 | // Handle the processing of break. |
| 54 | DisableBreak disable_break_scope(isolate->debug(), disable_break); |
| 55 | |
| 56 | // Get the frame where the debugging is performed. |
| 57 | JavaScriptFrameIterator it(isolate, frame_id); |
| 58 | JavaScriptFrame* frame = it.frame(); |
| 59 | |
| 60 | // Traverse the saved contexts chain to find the active context for the |
| 61 | // selected frame. |
| 62 | SaveContext* save = |
| 63 | DebugFrameHelper::FindSavedContextForFrame(isolate, frame); |
| 64 | SaveContext savex(isolate); |
| 65 | isolate->set_context(*(save->context())); |
| 66 | |
| 67 | // This is not a lot different than DebugEvaluate::Global, except that |
| 68 | // variables accessible by the function we are evaluating from are |
| 69 | // materialized and included on top of the native context. Changes to |
| 70 | // the materialized object are written back afterwards. |
| 71 | // Note that the native context is taken from the original context chain, |
| 72 | // which may not be the current native context of the isolate. |
| 73 | ContextBuilder context_builder(isolate, frame, inlined_jsframe_index); |
| 74 | if (isolate->has_pending_exception()) return MaybeHandle<Object>(); |
| 75 | |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 76 | Handle<Context> context = context_builder.evaluation_context(); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 77 | Handle<JSObject> receiver(context->global_proxy()); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 78 | MaybeHandle<Object> maybe_result = |
| 79 | Evaluate(isolate, context_builder.outer_info(), context, |
| 80 | context_extension, receiver, source); |
| 81 | if (!maybe_result.is_null()) context_builder.UpdateValues(); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 82 | return maybe_result; |
| 83 | } |
| 84 | |
| 85 | |
| 86 | // Compile and evaluate source for the given context. |
| 87 | MaybeHandle<Object> DebugEvaluate::Evaluate( |
| 88 | Isolate* isolate, Handle<SharedFunctionInfo> outer_info, |
| 89 | Handle<Context> context, Handle<HeapObject> context_extension, |
| 90 | Handle<Object> receiver, Handle<String> source) { |
| 91 | if (context_extension->IsJSObject()) { |
| 92 | Handle<JSObject> extension = Handle<JSObject>::cast(context_extension); |
| 93 | Handle<JSFunction> closure(context->closure(), isolate); |
| 94 | context = isolate->factory()->NewWithContext(closure, context, extension); |
| 95 | } |
| 96 | |
| 97 | Handle<JSFunction> eval_fun; |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 98 | ASSIGN_RETURN_ON_EXCEPTION( |
| 99 | isolate, eval_fun, |
| 100 | Compiler::GetFunctionFromEval( |
| 101 | source, outer_info, context, SLOPPY, NO_PARSE_RESTRICTION, |
| 102 | RelocInfo::kNoPosition, RelocInfo::kNoPosition), |
| 103 | Object); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 104 | |
| 105 | Handle<Object> result; |
| 106 | ASSIGN_RETURN_ON_EXCEPTION( |
| 107 | isolate, result, Execution::Call(isolate, eval_fun, receiver, 0, NULL), |
| 108 | Object); |
| 109 | |
| 110 | // Skip the global proxy as it has no properties and always delegates to the |
| 111 | // real global object. |
| 112 | if (result->IsJSGlobalProxy()) { |
Ben Murdoch | 097c5b2 | 2016-05-18 11:27:45 +0100 | [diff] [blame] | 113 | PrototypeIterator iter(isolate, Handle<JSGlobalProxy>::cast(result)); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 114 | // TODO(verwaest): This will crash when the global proxy is detached. |
| 115 | result = PrototypeIterator::GetCurrent<JSObject>(iter); |
| 116 | } |
| 117 | |
| 118 | return result; |
| 119 | } |
| 120 | |
| 121 | |
| 122 | DebugEvaluate::ContextBuilder::ContextBuilder(Isolate* isolate, |
| 123 | JavaScriptFrame* frame, |
| 124 | int inlined_jsframe_index) |
| 125 | : isolate_(isolate), |
| 126 | frame_(frame), |
| 127 | inlined_jsframe_index_(inlined_jsframe_index) { |
| 128 | FrameInspector frame_inspector(frame, inlined_jsframe_index, isolate); |
| 129 | Handle<JSFunction> local_function = |
Ben Murdoch | 097c5b2 | 2016-05-18 11:27:45 +0100 | [diff] [blame] | 130 | Handle<JSFunction>::cast(frame_inspector.GetFunction()); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 131 | Handle<Context> outer_context(local_function->context()); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 132 | evaluation_context_ = outer_context; |
| 133 | outer_info_ = handle(local_function->shared()); |
| 134 | Factory* factory = isolate->factory(); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 135 | |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 136 | // To evaluate as if we were running eval at the point of the debug break, |
| 137 | // we reconstruct the context chain as follows: |
| 138 | // - To make stack-allocated variables visible, we materialize them and |
| 139 | // use a debug-evaluate context to wrap both the materialized object and |
| 140 | // the original context. |
| 141 | // - We use the original context chain from the function context to the |
| 142 | // native context. |
| 143 | // - Between the function scope and the native context, we only resolve |
| 144 | // variable names that the current function already uses. Only for these |
| 145 | // names we can be sure that they will be correctly resolved. For the |
| 146 | // rest, we only resolve to with, script, and native contexts. We use a |
| 147 | // whitelist to implement that. |
| 148 | // Context::Lookup has special handling for debug-evaluate contexts: |
| 149 | // - Look up in the materialized stack variables. |
| 150 | // - Look up in the original context. |
| 151 | // - Check the whitelist to find out whether to skip contexts during lookup. |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 152 | const ScopeIterator::Option option = ScopeIterator::COLLECT_NON_LOCALS; |
| 153 | for (ScopeIterator it(isolate, &frame_inspector, option); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 154 | !it.Failed() && !it.Done(); it.Next()) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 155 | ScopeIterator::ScopeType scope_type = it.Type(); |
| 156 | if (scope_type == ScopeIterator::ScopeTypeLocal) { |
| 157 | DCHECK_EQ(FUNCTION_SCOPE, it.CurrentScopeInfo()->scope_type()); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 158 | Handle<JSObject> materialized = factory->NewJSObjectWithNullProto(); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 159 | Handle<Context> local_context = |
| 160 | it.HasContext() ? it.CurrentContext() : outer_context; |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 161 | Handle<StringSet> non_locals = it.GetNonLocals(); |
| 162 | MaterializeReceiver(materialized, local_context, local_function, |
| 163 | non_locals); |
| 164 | frame_inspector.MaterializeStackLocals(materialized, local_function); |
| 165 | MaterializeArgumentsObject(materialized, local_function); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 166 | ContextChainElement context_chain_element; |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 167 | context_chain_element.scope_info = it.CurrentScopeInfo(); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 168 | context_chain_element.materialized_object = materialized; |
| 169 | // Non-locals that are already being referenced by the current function |
| 170 | // are guaranteed to be correctly resolved. |
| 171 | context_chain_element.whitelist = non_locals; |
| 172 | if (it.HasContext()) { |
| 173 | context_chain_element.wrapped_context = it.CurrentContext(); |
| 174 | } |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 175 | context_chain_.Add(context_chain_element); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 176 | evaluation_context_ = outer_context; |
| 177 | break; |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 178 | } else if (scope_type == ScopeIterator::ScopeTypeCatch || |
| 179 | scope_type == ScopeIterator::ScopeTypeWith) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 180 | ContextChainElement context_chain_element; |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 181 | Handle<Context> current_context = it.CurrentContext(); |
| 182 | if (!current_context->IsDebugEvaluateContext()) { |
| 183 | context_chain_element.wrapped_context = current_context; |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 184 | } |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 185 | context_chain_.Add(context_chain_element); |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 186 | } else if (scope_type == ScopeIterator::ScopeTypeBlock || |
| 187 | scope_type == ScopeIterator::ScopeTypeEval) { |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 188 | Handle<JSObject> materialized = factory->NewJSObjectWithNullProto(); |
| 189 | frame_inspector.MaterializeStackLocals(materialized, |
| 190 | it.CurrentScopeInfo()); |
| 191 | ContextChainElement context_chain_element; |
| 192 | context_chain_element.scope_info = it.CurrentScopeInfo(); |
| 193 | context_chain_element.materialized_object = materialized; |
| 194 | if (it.HasContext()) { |
| 195 | context_chain_element.wrapped_context = it.CurrentContext(); |
| 196 | } |
| 197 | context_chain_.Add(context_chain_element); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 198 | } else { |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 199 | break; |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 200 | } |
| 201 | } |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 202 | |
| 203 | for (int i = context_chain_.length() - 1; i >= 0; i--) { |
| 204 | evaluation_context_ = factory->NewDebugEvaluateContext( |
| 205 | evaluation_context_, context_chain_[i].materialized_object, |
| 206 | context_chain_[i].wrapped_context, context_chain_[i].whitelist); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 207 | } |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 208 | } |
| 209 | |
| 210 | |
| 211 | void DebugEvaluate::ContextBuilder::UpdateValues() { |
| 212 | // TODO(yangguo): remove updating values. |
| 213 | for (int i = 0; i < context_chain_.length(); i++) { |
| 214 | ContextChainElement element = context_chain_[i]; |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 215 | if (!element.materialized_object.is_null()) { |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 216 | // Write back potential changes to materialized stack locals to the stack. |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 217 | FrameInspector(frame_, inlined_jsframe_index_, isolate_) |
| 218 | .UpdateStackLocalsFromMaterializedObject(element.materialized_object, |
| 219 | element.scope_info); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 220 | } |
| 221 | } |
| 222 | } |
| 223 | |
| 224 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 225 | void DebugEvaluate::ContextBuilder::MaterializeArgumentsObject( |
| 226 | Handle<JSObject> target, Handle<JSFunction> function) { |
| 227 | // Do not materialize the arguments object for eval or top-level code. |
| 228 | // Skip if "arguments" is already taken. |
| 229 | if (!function->shared()->is_function()) return; |
| 230 | Maybe<bool> maybe = JSReceiver::HasOwnProperty( |
| 231 | target, isolate_->factory()->arguments_string()); |
| 232 | DCHECK(maybe.IsJust()); |
| 233 | if (maybe.FromJust()) return; |
| 234 | |
| 235 | // FunctionGetArguments can't throw an exception. |
Ben Murdoch | 097c5b2 | 2016-05-18 11:27:45 +0100 | [diff] [blame] | 236 | Handle<JSObject> arguments = Accessors::FunctionGetArguments(function); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 237 | Handle<String> arguments_str = isolate_->factory()->arguments_string(); |
| 238 | JSObject::SetOwnPropertyIgnoreAttributes(target, arguments_str, arguments, |
| 239 | NONE) |
| 240 | .Check(); |
| 241 | } |
| 242 | |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 243 | void DebugEvaluate::ContextBuilder::MaterializeReceiver( |
| 244 | Handle<JSObject> target, Handle<Context> local_context, |
| 245 | Handle<JSFunction> local_function, Handle<StringSet> non_locals) { |
| 246 | Handle<Object> recv = isolate_->factory()->undefined_value(); |
| 247 | Handle<String> name = isolate_->factory()->this_string(); |
| 248 | if (non_locals->Has(name)) { |
| 249 | // 'this' is allocated in an outer context and is is already being |
| 250 | // referenced by the current function, so it can be correctly resolved. |
| 251 | return; |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 252 | } else if (local_function->shared()->scope_info()->HasReceiver() && |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 253 | !frame_->receiver()->IsTheHole(isolate_)) { |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 254 | recv = handle(frame_->receiver(), isolate_); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 255 | } |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 256 | JSObject::SetOwnPropertyIgnoreAttributes(target, name, recv, NONE).Check(); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 257 | } |
| 258 | |
| 259 | } // namespace internal |
| 260 | } // namespace v8 |