The Tor Browser: js/src/frontend/SyntaxParseHandler.h@6474c204b198

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

     1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-

     2  * vim: set ts=8 sts=4 et sw=4 tw=99:

     3  * This Source Code Form is subject to the terms of the Mozilla Public

     4  * License, v. 2.0. If a copy of the MPL was not distributed with this

     5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     7 #ifndef frontend_SyntaxParseHandler_h

     8 #define frontend_SyntaxParseHandler_h

    10 #include "frontend/ParseNode.h"

    11 #include "frontend/TokenStream.h"

    13 namespace js {

    14 namespace frontend {

    16 template <typename ParseHandler>

    17 class Parser;

    19 // Parse handler used when processing the syntax in a block of code, to generate

    20 // the minimal information which is required to detect syntax errors and allow

    21 // bytecode to be emitted for outer functions.

    22 //

    23 // When parsing, we start at the top level with a full parse, and when possible

    24 // only check the syntax for inner functions, so that they can be lazily parsed

    25 // into bytecode when/if they first run. Checking the syntax of a function is

    26 // several times faster than doing a full parse/emit, and lazy parsing improves

    27 // both performance and memory usage significantly when pages contain large

    28 // amounts of code that never executes (which happens often).

    29 class SyntaxParseHandler

    30 {

    31     // Remember the last encountered name or string literal during syntax parses.

    32     JSAtom *lastAtom;

    33     TokenPos lastStringPos;

    34     TokenStream &tokenStream;

    36   public:

    37     enum Node {

    38         NodeFailure = 0,

    39         NodeGeneric,

    40         NodeName,

    41         NodeGetProp,

    42         NodeString,

    43         NodeStringExprStatement,

    44         NodeLValue

    45     };

    46     typedef Definition::Kind DefinitionNode;

    48     SyntaxParseHandler(ExclusiveContext *cx, LifoAlloc &alloc,

    49                        TokenStream &tokenStream, bool foldConstants,

    50                        Parser<SyntaxParseHandler> *syntaxParser, LazyScript *lazyOuterFunction)

    51       : lastAtom(nullptr),

    52         tokenStream(tokenStream)

    53     {}

    55     static Node null() { return NodeFailure; }

    57     void trace(JSTracer *trc) {}

    59     Node newName(PropertyName *name, uint32_t blockid, const TokenPos &pos) {

    60         lastAtom = name;

    61         return NodeName;

    62     }

    64     DefinitionNode newPlaceholder(JSAtom *atom, uint32_t blockid, const TokenPos &pos) {

    65         return Definition::PLACEHOLDER;

    66     }

    68     Node newIdentifier(JSAtom *atom, const TokenPos &pos) { return NodeString; }

    69     Node newNumber(double value, DecimalPoint decimalPoint, const TokenPos &pos) { return NodeGeneric; }

    70     Node newBooleanLiteral(bool cond, const TokenPos &pos) { return NodeGeneric; }

    72     Node newStringLiteral(JSAtom *atom, const TokenPos &pos) {

    73         lastAtom = atom;

    74         lastStringPos = pos;

    75         return NodeString;

    76     }

    78     Node newThisLiteral(const TokenPos &pos) { return NodeGeneric; }

    79     Node newNullLiteral(const TokenPos &pos) { return NodeGeneric; }

    81     template <class Boxer>

    82     Node newRegExp(JSObject *reobj, const TokenPos &pos, Boxer &boxer) { return NodeGeneric; }

    84     Node newConditional(Node cond, Node thenExpr, Node elseExpr) { return NodeGeneric; }

    86     Node newElision() { return NodeGeneric; }

    88     Node newDelete(uint32_t begin, Node expr) { return NodeGeneric; }

    90     Node newUnary(ParseNodeKind kind, JSOp op, uint32_t begin, Node kid) {

    91         return NodeGeneric;

    92     }

    94     Node newBinary(ParseNodeKind kind, JSOp op = JSOP_NOP) { return NodeGeneric; }

    95     Node newBinary(ParseNodeKind kind, Node left, JSOp op = JSOP_NOP) { return NodeGeneric; }

    96     Node newBinary(ParseNodeKind kind, Node left, Node right, JSOp op = JSOP_NOP) {

    97         return NodeGeneric;

    98     }

    99     Node newBinaryOrAppend(ParseNodeKind kind, Node left, Node right,

   100                            ParseContext<SyntaxParseHandler> *pc, JSOp op = JSOP_NOP) {

   101         return NodeGeneric;

   102     }

   104     Node newTernary(ParseNodeKind kind, Node first, Node second, Node third, JSOp op = JSOP_NOP) {

   105         return NodeGeneric;

   106     }

   108     // Expressions

   110     Node newArrayComprehension(Node body, unsigned blockid, const TokenPos &pos) {

   111         return NodeGeneric;

   112     }

   113     Node newArrayLiteral(uint32_t begin, unsigned blockid) { return NodeGeneric; }

   114     bool addElision(Node literal, const TokenPos &pos) { return true; }

   115     bool addSpreadElement(Node literal, uint32_t begin, Node inner) { return true; }

   116     bool addArrayElement(Node literal, Node element) { return true; }

   118     Node newObjectLiteral(uint32_t begin) { return NodeGeneric; }

   119     bool addPrototypeMutation(Node literal, uint32_t begin, Node expr) { return true; }

   120     bool addPropertyDefinition(Node literal, Node name, Node expr) { return true; }

   121     bool addShorthandPropertyDefinition(Node literal, Node name) { return true; }

   122     bool addAccessorPropertyDefinition(Node literal, Node name, Node fn, JSOp op) { return true; }

   124     // Statements

   126     Node newStatementList(unsigned blockid, const TokenPos &pos) { return NodeGeneric; }

   127     void addStatementToList(Node list, Node stmt, ParseContext<SyntaxParseHandler> *pc) {}

   128     Node newEmptyStatement(const TokenPos &pos) { return NodeGeneric; }

   130     Node newExprStatement(Node expr, uint32_t end) {

   131         return expr == NodeString ? NodeStringExprStatement : NodeGeneric;

   132     }

   134     Node newIfStatement(uint32_t begin, Node cond, Node then, Node else_) { return NodeGeneric; }

   135     Node newDoWhileStatement(Node body, Node cond, const TokenPos &pos) { return NodeGeneric; }

   136     Node newWhileStatement(uint32_t begin, Node cond, Node body) { return NodeGeneric; }

   137     Node newSwitchStatement(uint32_t begin, Node discriminant, Node caseList) { return NodeGeneric; }

   138     Node newCaseOrDefault(uint32_t begin, Node expr, Node body) { return NodeGeneric; }

   139     Node newContinueStatement(PropertyName *label, const TokenPos &pos) { return NodeGeneric; }

   140     Node newBreakStatement(PropertyName *label, const TokenPos &pos) { return NodeGeneric; }

   141     Node newReturnStatement(Node expr, const TokenPos &pos) { return NodeGeneric; }

   143     Node newLabeledStatement(PropertyName *label, Node stmt, uint32_t begin) {

   144         return NodeGeneric;

   145     }

   147     Node newThrowStatement(Node expr, const TokenPos &pos) { return NodeGeneric; }

   148     Node newTryStatement(uint32_t begin, Node body, Node catchList, Node finallyBlock) {

   149         return NodeGeneric;

   150     }

   151     Node newDebuggerStatement(const TokenPos &pos) { return NodeGeneric; }

   153     Node newPropertyAccess(Node pn, PropertyName *name, uint32_t end) {

   154         lastAtom = name;

   155         return NodeGetProp;

   156     }

   158     Node newPropertyByValue(Node pn, Node kid, uint32_t end) { return NodeLValue; }

   160     bool addCatchBlock(Node catchList, Node letBlock,

   161                        Node catchName, Node catchGuard, Node catchBody) { return true; }

   163     void setLastFunctionArgumentDefault(Node funcpn, Node pn) {}

   164     Node newFunctionDefinition() { return NodeGeneric; }

   165     void setFunctionBody(Node pn, Node kid) {}

   166     void setFunctionBox(Node pn, FunctionBox *funbox) {}

   167     void addFunctionArgument(Node pn, Node argpn) {}

   169     Node newForStatement(uint32_t begin, Node forHead, Node body, unsigned iflags) {

   170         return NodeGeneric;

   171     }

   173     Node newForHead(ParseNodeKind kind, Node decls, Node lhs, Node rhs, const TokenPos &pos) {

   174         return NodeGeneric;

   175     }

   177     Node newLexicalScope(ObjectBox *blockbox) { return NodeGeneric; }

   178     void setLexicalScopeBody(Node block, Node body) {}

   180     bool isOperationWithoutParens(Node pn, ParseNodeKind kind) {

   181         // It is OK to return false here, callers should only use this method

   182         // for reporting strict option warnings and parsing code which the

   183         // syntax parser does not handle.

   184         return false;

   185     }

   187     bool finishInitializerAssignment(Node pn, Node init, JSOp op) { return true; }

   189     void setBeginPosition(Node pn, Node oth) {}

   190     void setBeginPosition(Node pn, uint32_t begin) {}

   192     void setEndPosition(Node pn, Node oth) {}

   193     void setEndPosition(Node pn, uint32_t end) {}

   196     void setPosition(Node pn, const TokenPos &pos) {}

   197     TokenPos getPosition(Node pn) {

   198         return tokenStream.currentToken().pos;

   199     }

   201     Node newList(ParseNodeKind kind, Node kid = NodeGeneric, JSOp op = JSOP_NOP) {

   202         return NodeGeneric;

   203     }

   204     void addList(Node pn, Node kid) {}

   205     bool isUnparenthesizedYield(Node pn) { return false; }

   207     void setOp(Node pn, JSOp op) {}

   208     void setBlockId(Node pn, unsigned blockid) {}

   209     void setFlag(Node pn, unsigned flag) {}

   210     void setListFlag(Node pn, unsigned flag) {}

   211     Node setInParens(Node pn) {

   212         // String literals enclosed by parentheses are ignored during

   213         // strict mode parsing.

   214         return NodeGeneric;

   215     }

   216     void setPrologue(Node pn) {}

   218     bool isConstant(Node pn) { return false; }

   219     PropertyName *isName(Node pn) {

   220         return (pn == NodeName) ? lastAtom->asPropertyName() : nullptr;

   221     }

   222     PropertyName *isGetProp(Node pn) {

   223         return (pn == NodeGetProp) ? lastAtom->asPropertyName() : nullptr;

   224     }

   225     JSAtom *isStringExprStatement(Node pn, TokenPos *pos) {

   226         if (pn == NodeStringExprStatement) {

   227             *pos = lastStringPos;

   228             return lastAtom;

   229         }

   230         return nullptr;

   231     }

   233     Node makeAssignment(Node pn, Node rhs) { return NodeGeneric; }

   235     static Node getDefinitionNode(DefinitionNode dn) { return NodeGeneric; }

   236     static Definition::Kind getDefinitionKind(DefinitionNode dn) { return dn; }

   237     void linkUseToDef(Node pn, DefinitionNode dn) {}

   238     DefinitionNode resolve(DefinitionNode dn) { return dn; }

   239     void deoptimizeUsesWithin(DefinitionNode dn, const TokenPos &pos) {}

   240     bool dependencyCovered(Node pn, unsigned blockid, bool functionScope) {

   241         // Only resolve lexical dependencies in cases where a definition covers

   242         // the entire function. Not enough information is kept to compare the

   243         // dependency location with blockid.

   244         return functionScope;

   245     }

   247     static uintptr_t definitionToBits(DefinitionNode dn) {

   248         // Use a shift, as DefinitionList tags the lower bit of its associated union.

   249         return uintptr_t(dn << 1);

   250     }

   251     static DefinitionNode definitionFromBits(uintptr_t bits) {

   252         return (DefinitionNode) (bits >> 1);

   253     }

   254     static DefinitionNode nullDefinition() {

   255         return Definition::MISSING;

   256     }

   257     void disableSyntaxParser() {

   258     }

   259 };

   261 } // namespace frontend

   262 } // namespace js

   264 #endif /* frontend_SyntaxParseHandler_h */

The Tor Browser / file revision

js/src/frontend/SyntaxParseHandler.h@6474c204b198

js/src/frontend/SyntaxParseHandler.h