79 lines
3.5 KiB
C
79 lines
3.5 KiB
C
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// Copyright 2010 the V8 project authors. All rights reserved.
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// Redistribution and use in source and binary forms, with or without
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// modification, are permitted provided that the following conditions are
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// met:
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//
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// * Redistributions of source code must retain the above copyright
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// notice, this list of conditions and the following disclaimer.
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// * Redistributions in binary form must reproduce the above
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// copyright notice, this list of conditions and the following
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// disclaimer in the documentation and/or other materials provided
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// with the distribution.
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// * Neither the name of Google Inc. nor the names of its
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// contributors may be used to endorse or promote products derived
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// from this software without specific prior written permission.
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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#ifndef V8_LIVEEDIT_H_
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#define V8_LIVEEDIT_H_
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// Live Edit feature implementation.
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// User should be able to change script on already running VM. This feature
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// matches hot swap features in other frameworks.
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//
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// The basic use-case is when user spots some mistake in function body
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// from debugger and wishes to change the algorithm without restart.
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//
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// A single change always has a form of a simple replacement (in pseudo-code):
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// script.source[positions, positions+length] = new_string;
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// Implementation first determines, which function's body includes this
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// change area. Then both old and new versions of script are fully compiled
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// in order to analyze, whether the function changed its outer scope
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// expectations (or number of parameters). If it didn't, function's code is
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// patched with a newly compiled code. If it did change, enclosing function
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// gets patched. All inner functions are left untouched, whatever happened
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// to them in a new script version. However, new version of code will
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// instantiate newly compiled functions.
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#include "compiler.h"
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namespace v8 {
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namespace internal {
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// This class collects some specific information on structure of functions
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// in a particular script. It gets called from compiler all the time, but
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// actually records any data only when liveedit operation is in process;
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// in any other time this class is very cheap.
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//
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// The primary interest of the Tracker is to record function scope structures
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// in order to analyze whether function code maybe safely patched (with new
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// code successfully reading existing data from function scopes). The Tracker
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// also collects compiled function codes.
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class LiveEditFunctionTracker {
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public:
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LiveEditFunctionTracker(FunctionLiteral* fun);
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~LiveEditFunctionTracker();
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void RecordFunctionCode(Handle<Code> code);
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void RecordFunctionScope(Scope* scope);
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static bool IsActive();
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};
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} } // namespace v8::internal
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#endif /* V*_LIVEEDIT_H_ */
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