1 // Copyright 2014 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_AST_AST_NUMBERING_H_ 6 #define V8_AST_AST_NUMBERING_H_ 7 8 #include <stdint.h> 9 10 namespace v8 { 11 namespace internal { 12 13 // Forward declarations. 14 class FunctionLiteral; 15 class Isolate; 16 class Zone; 17 template <typename T> 18 class ThreadedList; 19 template <typename T> 20 class ThreadedListZoneEntry; 21 template <typename T> 22 class ZoneVector; 23 24 namespace AstNumbering { 25 // Assign type feedback IDs, bailout IDs, and generator yield IDs to an AST node 26 // tree; perform catch prediction for TryStatements. If |eager_literals| is 27 // non-null, adds any eager inner literal functions into it. 28 bool Renumber( 29 uintptr_t stack_limit, Zone* zone, FunctionLiteral* function, 30 ThreadedList<ThreadedListZoneEntry<FunctionLiteral*>>* eager_literals); 31 } 32 33 // Some details on yield IDs 34 // ------------------------- 35 // 36 // In order to assist Ignition in generating bytecode for a generator function, 37 // we assign a unique number (the yield ID) to each Yield node in its AST. We 38 // also annotate loops with the number of yields they contain (loop.yield_count) 39 // and the smallest ID of those (loop.first_yield_id), and we annotate the 40 // function itself with the number of yields it contains (function.yield_count). 41 // 42 // The way in which we choose the IDs is simply by enumerating the Yield nodes. 43 // Ignition relies on the following properties: 44 // - For each loop l and each yield y of l: 45 // l.first_yield_id <= y.yield_id < l.first_yield_id + l.yield_count 46 // - For the generator function f itself and each yield y of f: 47 // 0 <= y.yield_id < f.yield_count 48 49 } // namespace internal 50 } // namespace v8 51 52 #endif // V8_AST_AST_NUMBERING_H_ 53