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 | #ifndef V8_DEBUG_DEBUG_EVALUATE_H_ |
| 6 | #define V8_DEBUG_DEBUG_EVALUATE_H_ |
| 7 | |
| 8 | #include "src/frames.h" |
| 9 | #include "src/objects.h" |
| 10 | |
| 11 | namespace v8 { |
| 12 | namespace internal { |
| 13 | |
| 14 | class DebugEvaluate : public AllStatic { |
| 15 | public: |
| 16 | static MaybeHandle<Object> Global(Isolate* isolate, Handle<String> source, |
| 17 | bool disable_break, |
| 18 | Handle<HeapObject> context_extension); |
| 19 | |
| 20 | // Evaluate a piece of JavaScript in the context of a stack frame for |
| 21 | // debugging. Things that need special attention are: |
| 22 | // - Parameters and stack-allocated locals need to be materialized. Altered |
| 23 | // values need to be written back to the stack afterwards. |
| 24 | // - The arguments object needs to materialized. |
| 25 | static MaybeHandle<Object> Local(Isolate* isolate, StackFrame::Id frame_id, |
| 26 | int inlined_jsframe_index, |
| 27 | Handle<String> source, bool disable_break, |
| 28 | Handle<HeapObject> context_extension); |
| 29 | |
| 30 | private: |
| 31 | // This class builds a context chain for evaluation of expressions |
| 32 | // in debugger. |
| 33 | // The scope chain leading up to a breakpoint where evaluation occurs |
| 34 | // looks like: |
| 35 | // - [a mix of with, catch and block scopes] |
| 36 | // - [function stack + context] |
| 37 | // - [outer context] |
| 38 | // The builder materializes all stack variables into properties of objects; |
| 39 | // the expression is then evaluated as if it is inside a series of 'with' |
| 40 | // statements using those objects. To this end, the builder builds a new |
| 41 | // context chain, based on a scope chain: |
| 42 | // - every With and Catch scope begets a cloned context |
| 43 | // - Block scope begets one or two contexts: |
| 44 | // - if a block has context-allocated varaibles, its context is cloned |
| 45 | // - stack locals are materizalized as a With context |
| 46 | // - Local scope begets a With context for materizalized locals, chained to |
| 47 | // original function context. Original function context is the end of |
| 48 | // the chain. |
| 49 | class ContextBuilder { |
| 50 | public: |
| 51 | ContextBuilder(Isolate* isolate, JavaScriptFrame* frame, |
| 52 | int inlined_jsframe_index); |
| 53 | |
| 54 | void UpdateValues(); |
| 55 | |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 56 | Handle<Context> evaluation_context() const { return evaluation_context_; } |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 57 | Handle<SharedFunctionInfo> outer_info() const { return outer_info_; } |
| 58 | |
| 59 | private: |
| 60 | struct ContextChainElement { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 61 | Handle<ScopeInfo> scope_info; |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 62 | Handle<Context> wrapped_context; |
| 63 | Handle<JSObject> materialized_object; |
| 64 | Handle<StringSet> whitelist; |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 65 | }; |
| 66 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 67 | // Helper function to find or create the arguments object for |
| 68 | // Runtime_DebugEvaluate. |
| 69 | void MaterializeArgumentsObject(Handle<JSObject> target, |
| 70 | Handle<JSFunction> function); |
| 71 | |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 72 | void MaterializeReceiver(Handle<JSObject> target, |
| 73 | Handle<Context> local_context, |
| 74 | Handle<JSFunction> local_function, |
| 75 | Handle<StringSet> non_locals); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 76 | |
| 77 | Handle<SharedFunctionInfo> outer_info_; |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 78 | Handle<Context> evaluation_context_; |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 79 | List<ContextChainElement> context_chain_; |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 80 | Isolate* isolate_; |
| 81 | JavaScriptFrame* frame_; |
| 82 | int inlined_jsframe_index_; |
| 83 | }; |
| 84 | |
| 85 | static MaybeHandle<Object> Evaluate(Isolate* isolate, |
| 86 | Handle<SharedFunctionInfo> outer_info, |
| 87 | Handle<Context> context, |
| 88 | Handle<HeapObject> context_extension, |
| 89 | Handle<Object> receiver, |
| 90 | Handle<String> source); |
| 91 | }; |
| 92 | |
| 93 | |
| 94 | } // namespace internal |
| 95 | } // namespace v8 |
| 96 | |
| 97 | #endif // V8_DEBUG_DEBUG_EVALUATE_H_ |