comparison vendor/nikic/php-parser/lib/PhpParser/ParserAbstract.php @ 0:c75dbcec494b

Initial commit from drush-created site

+<?php declare(strict_types=1);
+
+namespace PhpParser;
+
+/*
+ * This parser is based on a skeleton written by Moriyoshi Koizumi, which in
+ * turn is based on work by Masato Bito.
+ */
+use PhpParser\Node\Expr;
+use PhpParser\Node\Name;
+use PhpParser\Node\Param;
+use PhpParser\Node\Scalar\LNumber;
+use PhpParser\Node\Scalar\String_;
+use PhpParser\Node\Stmt\Class_;
+use PhpParser\Node\Stmt\ClassConst;
+use PhpParser\Node\Stmt\ClassMethod;
+use PhpParser\Node\Stmt\Interface_;
+use PhpParser\Node\Stmt\Namespace_;
+use PhpParser\Node\Stmt\Property;
+use PhpParser\Node\Stmt\TryCatch;
+use PhpParser\Node\Stmt\UseUse;
+use PhpParser\Node\VarLikeIdentifier;
+
+abstract class ParserAbstract implements Parser
+{
+    const SYMBOL_NONE = -1;
+
+    /*
+     * The following members will be filled with generated parsing data:
+     */
+
+    /** @var int Size of $tokenToSymbol map */
+    protected $tokenToSymbolMapSize;
+    /** @var int Size of $action table */
+    protected $actionTableSize;
+    /** @var int Size of $goto table */
+    protected $gotoTableSize;
+
+    /** @var int Symbol number signifying an invalid token */
+    protected $invalidSymbol;
+    /** @var int Symbol number of error recovery token */
+    protected $errorSymbol;
+    /** @var int Action number signifying default action */
+    protected $defaultAction;
+    /** @var int Rule number signifying that an unexpected token was encountered */
+    protected $unexpectedTokenRule;
+
+    protected $YY2TBLSTATE;
+    /** @var int Number of non-leaf states */
+    protected $numNonLeafStates;
+
+    /** @var int[] Map of lexer tokens to internal symbols */
+    protected $tokenToSymbol;
+    /** @var string[] Map of symbols to their names */
+    protected $symbolToName;
+    /** @var array Names of the production rules (only necessary for debugging) */
+    protected $productions;
+
+    /** @var int[] Map of states to a displacement into the $action table. The corresponding action for this
+     *             state/symbol pair is $action[$actionBase[$state] + $symbol]. If $actionBase[$state] is 0, the
+                   action is defaulted, i.e. $actionDefault[$state] should be used instead. */
+    protected $actionBase;
+    /** @var int[] Table of actions. Indexed according to $actionBase comment. */
+    protected $action;
+    /** @var int[] Table indexed analogously to $action. If $actionCheck[$actionBase[$state] + $symbol] != $symbol
+     *             then the action is defaulted, i.e. $actionDefault[$state] should be used instead. */
+    protected $actionCheck;
+    /** @var int[] Map of states to their default action */
+    protected $actionDefault;
+    /** @var callable[] Semantic action callbacks */
+    protected $reduceCallbacks;
+
+    /** @var int[] Map of non-terminals to a displacement into the $goto table. The corresponding goto state for this
+     *             non-terminal/state pair is $goto[$gotoBase[$nonTerminal] + $state] (unless defaulted) */
+    protected $gotoBase;
+    /** @var int[] Table of states to goto after reduction. Indexed according to $gotoBase comment. */
+    protected $goto;
+    /** @var int[] Table indexed analogously to $goto. If $gotoCheck[$gotoBase[$nonTerminal] + $state] != $nonTerminal
+     *             then the goto state is defaulted, i.e. $gotoDefault[$nonTerminal] should be used. */
+    protected $gotoCheck;
+    /** @var int[] Map of non-terminals to the default state to goto after their reduction */
+    protected $gotoDefault;
+
+    /** @var int[] Map of rules to the non-terminal on their left-hand side, i.e. the non-terminal to use for
+     *             determining the state to goto after reduction. */
+    protected $ruleToNonTerminal;
+    /** @var int[] Map of rules to the length of their right-hand side, which is the number of elements that have to
+     *             be popped from the stack(s) on reduction. */
+    protected $ruleToLength;
+
+    /*
+     * The following members are part of the parser state:
+     */
+
+    /** @var Lexer Lexer that is used when parsing */
+    protected $lexer;
+    /** @var mixed Temporary value containing the result of last semantic action (reduction) */
+    protected $semValue;
+    /** @var array Semantic value stack (contains values of tokens and semantic action results) */
+    protected $semStack;
+    /** @var array[] Start attribute stack */
+    protected $startAttributeStack;
+    /** @var array[] End attribute stack */
+    protected $endAttributeStack;
+    /** @var array End attributes of last *shifted* token */
+    protected $endAttributes;
+    /** @var array Start attributes of last *read* token */
+    protected $lookaheadStartAttributes;
+
+    /** @var ErrorHandler Error handler */
+    protected $errorHandler;
+    /** @var int Error state, used to avoid error floods */
+    protected $errorState;
+
+    /**
+     * Initialize $reduceCallbacks map.
+     */
+    abstract protected function initReduceCallbacks();
+
+    /**
+     * Creates a parser instance.
+     *
+     * Options: Currently none.
+     *
+     * @param Lexer $lexer A lexer
+     * @param array $options Options array.
+     */
+    public function __construct(Lexer $lexer, array $options = []) {
+        $this->lexer = $lexer;
+
+        if (isset($options['throwOnError'])) {
+            throw new \LogicException(
+                '"throwOnError" is no longer supported, use "errorHandler" instead');
+        }
+
+        $this->initReduceCallbacks();
+    }
+
+    /**
+     * Parses PHP code into a node tree.
+     *
+     * If a non-throwing error handler is used, the parser will continue parsing after an error
+     * occurred and attempt to build a partial AST.
+     *
+     * @param string $code The source code to parse
+     * @param ErrorHandler|null $errorHandler Error handler to use for lexer/parser errors, defaults
+     *                                        to ErrorHandler\Throwing.
+     *
+     * @return Node\Stmt[]|null Array of statements (or null non-throwing error handler is used and
+     *                          the parser was unable to recover from an error).
+     */
+    public function parse(string $code, ErrorHandler $errorHandler = null) {
+        $this->errorHandler = $errorHandler ?: new ErrorHandler\Throwing;
+
+        $this->lexer->startLexing($code, $this->errorHandler);
+        $result = $this->doParse();
+
+        // Clear out some of the interior state, so we don't hold onto unnecessary
+        // memory between uses of the parser
+        $this->startAttributeStack = [];
+        $this->endAttributeStack = [];
+        $this->semStack = [];
+        $this->semValue = null;
+
+        return $result;
+    }
+
+    protected function doParse() {
+        // We start off with no lookahead-token
+        $symbol = self::SYMBOL_NONE;
+
+        // The attributes for a node are taken from the first and last token of the node.
+        // From the first token only the startAttributes are taken and from the last only
+        // the endAttributes. Both are merged using the array union operator (+).
+        $startAttributes = [];
+        $endAttributes = [];
+        $this->endAttributes = $endAttributes;
+
+        // Keep stack of start and end attributes
+        $this->startAttributeStack = [];
+        $this->endAttributeStack = [$endAttributes];
+
+        // Start off in the initial state and keep a stack of previous states
+        $state = 0;
+        $stateStack = [$state];
+
+        // Semantic value stack (contains values of tokens and semantic action results)
+        $this->semStack = [];
+
+        // Current position in the stack(s)
+        $stackPos = 0;
+
+        $this->errorState = 0;
+
+        for (;;) {
+            //$this->traceNewState($state, $symbol);
+
+            if ($this->actionBase[$state] === 0) {
+                $rule = $this->actionDefault[$state];
+            } else {
+                if ($symbol === self::SYMBOL_NONE) {
+                    // Fetch the next token id from the lexer and fetch additional info by-ref.
+                    // The end attributes are fetched into a temporary variable and only set once the token is really
+                    // shifted (not during read). Otherwise you would sometimes get off-by-one errors, when a rule is
+                    // reduced after a token was read but not yet shifted.
+                    $tokenId = $this->lexer->getNextToken($tokenValue, $startAttributes, $endAttributes);
+
+                    // map the lexer token id to the internally used symbols
+                    $symbol = $tokenId >= 0 && $tokenId < $this->tokenToSymbolMapSize
+                        ? $this->tokenToSymbol[$tokenId]
+                        : $this->invalidSymbol;
+
+                    if ($symbol === $this->invalidSymbol) {
+                        throw new \RangeException(sprintf(
+                            'The lexer returned an invalid token (id=%d, value=%s)',
+                            $tokenId, $tokenValue
+                        ));
+                    }
+
+                    // This is necessary to assign some meaningful attributes to /* empty */ productions. They'll get
+                    // the attributes of the next token, even though they don't contain it themselves.
+                    $this->startAttributeStack[$stackPos+1] = $startAttributes;
+                    $this->endAttributeStack[$stackPos+1] = $endAttributes;
+                    $this->lookaheadStartAttributes = $startAttributes;
+
+                    //$this->traceRead($symbol);
+                }
+
+                $idx = $this->actionBase[$state] + $symbol;
+                if ((($idx >= 0 && $idx < $this->actionTableSize && $this->actionCheck[$idx] === $symbol)
+                     || ($state < $this->YY2TBLSTATE
+                         && ($idx = $this->actionBase[$state + $this->numNonLeafStates] + $symbol) >= 0
+                         && $idx < $this->actionTableSize && $this->actionCheck[$idx] === $symbol))
+                    && ($action = $this->action[$idx]) !== $this->defaultAction) {
+                    /*
+                     * >= numNonLeafStates: shift and reduce
+                     * > 0: shift
+                     * = 0: accept
+                     * < 0: reduce
+                     * = -YYUNEXPECTED: error
+                     */
+                    if ($action > 0) {
+                        /* shift */
+                        //$this->traceShift($symbol);
+
+                        ++$stackPos;
+                        $stateStack[$stackPos] = $state = $action;
+                        $this->semStack[$stackPos] = $tokenValue;
+                        $this->startAttributeStack[$stackPos] = $startAttributes;
+                        $this->endAttributeStack[$stackPos] = $endAttributes;
+                        $this->endAttributes = $endAttributes;
+                        $symbol = self::SYMBOL_NONE;
+
+                        if ($this->errorState) {
+                            --$this->errorState;
+                        }
+
+                        if ($action < $this->numNonLeafStates) {
+                            continue;
+                        }
+
+                        /* $yyn >= numNonLeafStates means shift-and-reduce */
+                        $rule = $action - $this->numNonLeafStates;
+                    } else {
+                        $rule = -$action;
+                    }
+                } else {
+                    $rule = $this->actionDefault[$state];
+                }
+            }
+
+            for (;;) {
+                if ($rule === 0) {
+                    /* accept */
+                    //$this->traceAccept();
+                    return $this->semValue;
+                } elseif ($rule !== $this->unexpectedTokenRule) {
+                    /* reduce */
+                    //$this->traceReduce($rule);
+
+                    try {
+                        $this->reduceCallbacks[$rule]($stackPos);
+                    } catch (Error $e) {
+                        if (-1 === $e->getStartLine() && isset($startAttributes['startLine'])) {
+                            $e->setStartLine($startAttributes['startLine']);
+                        }
+
+                        $this->emitError($e);
+                        // Can't recover from this type of error
+                        return null;
+                    }
+
+                    /* Goto - shift nonterminal */
+                    $lastEndAttributes = $this->endAttributeStack[$stackPos];
+                    $stackPos -= $this->ruleToLength[$rule];
+                    $nonTerminal = $this->ruleToNonTerminal[$rule];
+                    $idx = $this->gotoBase[$nonTerminal] + $stateStack[$stackPos];
+                    if ($idx >= 0 && $idx < $this->gotoTableSize && $this->gotoCheck[$idx] === $nonTerminal) {
+                        $state = $this->goto[$idx];
+                    } else {
+                        $state = $this->gotoDefault[$nonTerminal];
+                    }
+
+                    ++$stackPos;
+                    $stateStack[$stackPos]     = $state;
+                    $this->semStack[$stackPos] = $this->semValue;
+                    $this->endAttributeStack[$stackPos] = $lastEndAttributes;
+                } else {
+                    /* error */
+                    switch ($this->errorState) {
+                        case 0:
+                            $msg = $this->getErrorMessage($symbol, $state);
+                            $this->emitError(new Error($msg, $startAttributes + $endAttributes));
+                            // Break missing intentionally
+                        case 1:
+                        case 2:
+                            $this->errorState = 3;
+
+                            // Pop until error-expecting state uncovered
+                            while (!(
+                                (($idx = $this->actionBase[$state] + $this->errorSymbol) >= 0
+                                    && $idx < $this->actionTableSize && $this->actionCheck[$idx] === $this->errorSymbol)
+                                || ($state < $this->YY2TBLSTATE
+                                    && ($idx = $this->actionBase[$state + $this->numNonLeafStates] + $this->errorSymbol) >= 0
+                                    && $idx < $this->actionTableSize && $this->actionCheck[$idx] === $this->errorSymbol)
+                            ) || ($action = $this->action[$idx]) === $this->defaultAction) { // Not totally sure about this
+                                if ($stackPos <= 0) {
+                                    // Could not recover from error
+                                    return null;
+                                }
+                                $state = $stateStack[--$stackPos];
+                                //$this->tracePop($state);
+                            }
+
+                            //$this->traceShift($this->errorSymbol);
+                            ++$stackPos;
+                            $stateStack[$stackPos] = $state = $action;
+
+                            // We treat the error symbol as being empty, so we reset the end attributes
+                            // to the end attributes of the last non-error symbol
+                            $this->endAttributeStack[$stackPos] = $this->endAttributeStack[$stackPos - 1];
+                            $this->endAttributes = $this->endAttributeStack[$stackPos - 1];
+                            break;
+
+                        case 3:
+                            if ($symbol === 0) {
+                                // Reached EOF without recovering from error
+                                return null;
+                            }
+
+                            //$this->traceDiscard($symbol);
+                            $symbol = self::SYMBOL_NONE;
+                            break 2;
+                    }
+                }
+
+                if ($state < $this->numNonLeafStates) {
+                    break;
+                }
+
+                /* >= numNonLeafStates means shift-and-reduce */
+                $rule = $state - $this->numNonLeafStates;
+            }
+        }
+
+        throw new \RuntimeException('Reached end of parser loop');
+    }
+
+    protected function emitError(Error $error) {
+        $this->errorHandler->handleError($error);
+    }
+
+    /**
+     * Format error message including expected tokens.
+     *
+     * @param int $symbol Unexpected symbol
+     * @param int $state  State at time of error
+     *
+     * @return string Formatted error message
+     */
+    protected function getErrorMessage(int $symbol, int $state) : string {
+        $expectedString = '';
+        if ($expected = $this->getExpectedTokens($state)) {
+            $expectedString = ', expecting ' . implode(' or ', $expected);
+        }
+
+        return 'Syntax error, unexpected ' . $this->symbolToName[$symbol] . $expectedString;
+    }
+
+    /**
+     * Get limited number of expected tokens in given state.
+     *
+     * @param int $state State
+     *
+     * @return string[] Expected tokens. If too many, an empty array is returned.
+     */
+    protected function getExpectedTokens(int $state) : array {
+        $expected = [];
+
+        $base = $this->actionBase[$state];
+        foreach ($this->symbolToName as $symbol => $name) {
+            $idx = $base + $symbol;
+            if ($idx >= 0 && $idx < $this->actionTableSize && $this->actionCheck[$idx] === $symbol
+                || $state < $this->YY2TBLSTATE
+                && ($idx = $this->actionBase[$state + $this->numNonLeafStates] + $symbol) >= 0
+                && $idx < $this->actionTableSize && $this->actionCheck[$idx] === $symbol
+            ) {
+                if ($this->action[$idx] !== $this->unexpectedTokenRule
+                    && $this->action[$idx] !== $this->defaultAction
+                    && $symbol !== $this->errorSymbol
+                ) {
+                    if (count($expected) === 4) {
+                        /* Too many expected tokens */
+                        return [];
+                    }
+
+                    $expected[] = $name;
+                }
+            }
+        }
+
+        return $expected;
+    }
+
+    /*
+     * Tracing functions used for debugging the parser.
+     */
+
+    /*
+    protected function traceNewState($state, $symbol) {
+        echo '% State ' . $state
+            . ', Lookahead ' . ($symbol == self::SYMBOL_NONE ? '--none--' : $this->symbolToName[$symbol]) . "\n";
+    }
+
+    protected function traceRead($symbol) {
+        echo '% Reading ' . $this->symbolToName[$symbol] . "\n";
+    }
+
+    protected function traceShift($symbol) {
+        echo '% Shift ' . $this->symbolToName[$symbol] . "\n";
+    }
+
+    protected function traceAccept() {
+        echo "% Accepted.\n";
+    }
+
+    protected function traceReduce($n) {
+        echo '% Reduce by (' . $n . ') ' . $this->productions[$n] . "\n";
+    }
+
+    protected function tracePop($state) {
+        echo '% Recovering, uncovered state ' . $state . "\n";
+    }
+
+    protected function traceDiscard($symbol) {
+        echo '% Discard ' . $this->symbolToName[$symbol] . "\n";
+    }
+    */
+
+    /*
+     * Helper functions invoked by semantic actions
+     */
+
+    /**
+     * Moves statements of semicolon-style namespaces into $ns->stmts and checks various error conditions.
+     *
+     * @param Node\Stmt[] $stmts
+     * @return Node\Stmt[]
+     */
+    protected function handleNamespaces(array $stmts) : array {
+        $hasErrored = false;
+        $style = $this->getNamespacingStyle($stmts);
+        if (null === $style) {
+            // not namespaced, nothing to do
+            return $stmts;
+        } elseif ('brace' === $style) {
+            // For braced namespaces we only have to check that there are no invalid statements between the namespaces
+            $afterFirstNamespace = false;
+            foreach ($stmts as $stmt) {
+                if ($stmt instanceof Node\Stmt\Namespace_) {
+                    $afterFirstNamespace = true;
+                } elseif (!$stmt instanceof Node\Stmt\HaltCompiler
+                        && !$stmt instanceof Node\Stmt\Nop
+                        && $afterFirstNamespace && !$hasErrored) {
+                    $this->emitError(new Error(
+                        'No code may exist outside of namespace {}', $stmt->getAttributes()));
+                    $hasErrored = true; // Avoid one error for every statement
+                }
+            }
+            return $stmts;
+        } else {
+            // For semicolon namespaces we have to move the statements after a namespace declaration into ->stmts
+            $resultStmts = [];
+            $targetStmts =& $resultStmts;
+            $lastNs = null;
+            foreach ($stmts as $stmt) {
+                if ($stmt instanceof Node\Stmt\Namespace_) {
+                    if ($lastNs !== null) {
+                        $this->fixupNamespaceAttributes($lastNs);
+                    }
+                    if ($stmt->stmts === null) {
+                        $stmt->stmts = [];
+                        $targetStmts =& $stmt->stmts;
+                        $resultStmts[] = $stmt;
+                    } else {
+                        // This handles the invalid case of mixed style namespaces
+                        $resultStmts[] = $stmt;
+                        $targetStmts =& $resultStmts;
+                    }
+                    $lastNs = $stmt;
+                } elseif ($stmt instanceof Node\Stmt\HaltCompiler) {
+                    // __halt_compiler() is not moved into the namespace
+                    $resultStmts[] = $stmt;
+                } else {
+                    $targetStmts[] = $stmt;
+                }
+            }
+            if ($lastNs !== null) {
+                $this->fixupNamespaceAttributes($lastNs);
+            }
+            return $resultStmts;
+        }
+    }
+
+    private function fixupNamespaceAttributes(Node\Stmt\Namespace_ $stmt) {
+        // We moved the statements into the namespace node, as such the end of the namespace node
+        // needs to be extended to the end of the statements.
+        if (empty($stmt->stmts)) {
+            return;
+        }
+
+        // We only move the builtin end attributes here. This is the best we can do with the
+        // knowledge we have.
+        $endAttributes = ['endLine', 'endFilePos', 'endTokenPos'];
+        $lastStmt = $stmt->stmts[count($stmt->stmts) - 1];
+        foreach ($endAttributes as $endAttribute) {
+            if ($lastStmt->hasAttribute($endAttribute)) {
+                $stmt->setAttribute($endAttribute, $lastStmt->getAttribute($endAttribute));
+            }
+        }
+    }
+
+    /**
+     * Determine namespacing style (semicolon or brace)
+     *
+     * @param Node[] $stmts Top-level statements.
+     *
+     * @return null|string One of "semicolon", "brace" or null (no namespaces)
+     */
+    private function getNamespacingStyle(array $stmts) {
+        $style = null;
+        $hasNotAllowedStmts = false;
+        foreach ($stmts as $i => $stmt) {
+            if ($stmt instanceof Node\Stmt\Namespace_) {
+                $currentStyle = null === $stmt->stmts ? 'semicolon' : 'brace';
+                if (null === $style) {
+                    $style = $currentStyle;
+                    if ($hasNotAllowedStmts) {
+                        $this->emitError(new Error(
+                            'Namespace declaration statement has to be the very first statement in the script',
+                            $stmt->getLine() // Avoid marking the entire namespace as an error
+                        ));
+                    }
+                } elseif ($style !== $currentStyle) {
+                    $this->emitError(new Error(
+                        'Cannot mix bracketed namespace declarations with unbracketed namespace declarations',
+                        $stmt->getLine() // Avoid marking the entire namespace as an error
+                    ));
+                    // Treat like semicolon style for namespace normalization
+                    return 'semicolon';
+                }
+                continue;
+            }
+
+            /* declare(), __halt_compiler() and nops can be used before a namespace declaration */
+            if ($stmt instanceof Node\Stmt\Declare_
+                || $stmt instanceof Node\Stmt\HaltCompiler
+                || $stmt instanceof Node\Stmt\Nop) {
+                continue;
+            }
+
+            /* There may be a hashbang line at the very start of the file */
+            if ($i === 0 && $stmt instanceof Node\Stmt\InlineHTML && preg_match('/\A#!.*\r?\n\z/', $stmt->value)) {
+                continue;
+            }
+
+            /* Everything else if forbidden before namespace declarations */
+            $hasNotAllowedStmts = true;
+        }
+        return $style;
+    }
+
+    /**
+     * Fix up parsing of static property calls in PHP 5.
+     *
+     * In PHP 5 A::$b[c][d] and A::$b[c][d]() have very different interpretation. The former is
+     * interpreted as (A::$b)[c][d], while the latter is the same as A::{$b[c][d]}(). We parse the
+     * latter as the former initially and this method fixes the AST into the correct form when we
+     * encounter the "()".
+     *
+     * @param  Node\Expr\StaticPropertyFetch|Node\Expr\ArrayDimFetch $prop
+     * @param  Node\Arg[] $args
+     * @param  array      $attributes
+     *
+     * @return Expr\StaticCall
+     */
+    protected function fixupPhp5StaticPropCall($prop, array $args, array $attributes) : Expr\StaticCall {
+        if ($prop instanceof Node\Expr\StaticPropertyFetch) {
+            $name = $prop->name instanceof VarLikeIdentifier
+                ? $prop->name->toString() : $prop->name;
+            $var = new Expr\Variable($name, $prop->name->getAttributes());
+            return new Expr\StaticCall($prop->class, $var, $args, $attributes);
+        } elseif ($prop instanceof Node\Expr\ArrayDimFetch) {
+            $tmp = $prop;
+            while ($tmp->var instanceof Node\Expr\ArrayDimFetch) {
+                $tmp = $tmp->var;
+            }
+
+            /** @var Expr\StaticPropertyFetch $staticProp */
+            $staticProp = $tmp->var;
+
+            // Set start attributes to attributes of innermost node
+            $tmp = $prop;
+            $this->fixupStartAttributes($tmp, $staticProp->name);
+            while ($tmp->var instanceof Node\Expr\ArrayDimFetch) {
+                $tmp = $tmp->var;
+                $this->fixupStartAttributes($tmp, $staticProp->name);
+            }
+
+            $name = $staticProp->name instanceof VarLikeIdentifier
+                ? $staticProp->name->toString() : $staticProp->name;
+            $tmp->var = new Expr\Variable($name, $staticProp->name->getAttributes());
+            return new Expr\StaticCall($staticProp->class, $prop, $args, $attributes);
+        } else {
+            throw new \Exception;
+        }
+    }
+
+    protected function fixupStartAttributes(Node $to, Node $from) {
+        $startAttributes = ['startLine', 'startFilePos', 'startTokenPos'];
+        foreach ($startAttributes as $startAttribute) {
+            if ($from->hasAttribute($startAttribute)) {
+                $to->setAttribute($startAttribute, $from->getAttribute($startAttribute));
+            }
+        }
+    }
+
+    protected function handleBuiltinTypes(Name $name) {
+        $scalarTypes = [
+            'bool'     => true,
+            'int'      => true,
+            'float'    => true,
+            'string'   => true,
+            'iterable' => true,
+            'void'     => true,
+            'object'   => true,
+        ];
+
+        if (!$name->isUnqualified()) {
+            return $name;
+        }
+
+        $lowerName = $name->toLowerString();
+        if (!isset($scalarTypes[$lowerName])) {
+            return $name;
+        }
+
+        return new Node\Identifier($lowerName, $name->getAttributes());
+    }
+
+    /**
+     * Get combined start and end attributes at a stack location
+     *
+     * @param int $pos Stack location
+     *
+     * @return array Combined start and end attributes
+     */
+    protected function getAttributesAt(int $pos) : array {
+        return $this->startAttributeStack[$pos] + $this->endAttributeStack[$pos];
+    }
+
+    protected function parseLNumber($str, $attributes, $allowInvalidOctal = false) {
+        try {
+            return LNumber::fromString($str, $attributes, $allowInvalidOctal);
+        } catch (Error $error) {
+            $this->emitError($error);
+            // Use dummy value
+            return new LNumber(0, $attributes);
+        }
+    }
+
+    /**
+     * Parse a T_NUM_STRING token into either an integer or string node.
+     *
+     * @param string $str        Number string
+     * @param array  $attributes Attributes
+     *
+     * @return LNumber|String_ Integer or string node.
+     */
+    protected function parseNumString(string $str, array $attributes) {
+        if (!preg_match('/^(?:0|-?[1-9][0-9]*)$/', $str)) {
+            return new String_($str, $attributes);
+        }
+
+        $num = +$str;
+        if (!is_int($num)) {
+            return new String_($str, $attributes);
+        }
+
+        return new LNumber($num, $attributes);
+    }
+
+    protected function checkModifier($a, $b, $modifierPos) {
+        // Jumping through some hoops here because verifyModifier() is also used elsewhere
+        try {
+            Class_::verifyModifier($a, $b);
+        } catch (Error $error) {
+            $error->setAttributes($this->getAttributesAt($modifierPos));
+            $this->emitError($error);
+        }
+    }
+
+    protected function checkParam(Param $node) {
+        if ($node->variadic && null !== $node->default) {
+            $this->emitError(new Error(
+                'Variadic parameter cannot have a default value',
+                $node->default->getAttributes()
+            ));
+        }
+    }
+
+    protected function checkTryCatch(TryCatch $node) {
+        if (empty($node->catches) && null === $node->finally) {
+            $this->emitError(new Error(
+                'Cannot use try without catch or finally', $node->getAttributes()
+            ));
+        }
+    }
+
+    protected function checkNamespace(Namespace_ $node) {
+        if ($node->name && $node->name->isSpecialClassName()) {
+            $this->emitError(new Error(
+                sprintf('Cannot use \'%s\' as namespace name', $node->name),
+                $node->name->getAttributes()
+            ));
+        }
+
+        if (null !== $node->stmts) {
+            foreach ($node->stmts as $stmt) {
+                if ($stmt instanceof Namespace_) {
+                    $this->emitError(new Error(
+                        'Namespace declarations cannot be nested', $stmt->getAttributes()
+                    ));
+                }
+            }
+        }
+    }
+
+    protected function checkClass(Class_ $node, $namePos) {
+        if (null !== $node->name && $node->name->isSpecialClassName()) {
+            $this->emitError(new Error(
+                sprintf('Cannot use \'%s\' as class name as it is reserved', $node->name),
+                $this->getAttributesAt($namePos)
+            ));
+        }
+
+        if ($node->extends && $node->extends->isSpecialClassName()) {
+            $this->emitError(new Error(
+                sprintf('Cannot use \'%s\' as class name as it is reserved', $node->extends),
+                $node->extends->getAttributes()
+            ));
+        }
+
+        foreach ($node->implements as $interface) {
+            if ($interface->isSpecialClassName()) {
+                $this->emitError(new Error(
+                    sprintf('Cannot use \'%s\' as interface name as it is reserved', $interface),
+                    $interface->getAttributes()
+                ));
+            }
+        }
+    }
+
+    protected function checkInterface(Interface_ $node, $namePos) {
+        if (null !== $node->name && $node->name->isSpecialClassName()) {
+            $this->emitError(new Error(
+                sprintf('Cannot use \'%s\' as class name as it is reserved', $node->name),
+                $this->getAttributesAt($namePos)
+            ));
+        }
+
+        foreach ($node->extends as $interface) {
+            if ($interface->isSpecialClassName()) {
+                $this->emitError(new Error(
+                    sprintf('Cannot use \'%s\' as interface name as it is reserved', $interface),
+                    $interface->getAttributes()
+                ));
+            }
+        }
+    }
+
+    protected function checkClassMethod(ClassMethod $node, $modifierPos) {
+        if ($node->flags & Class_::MODIFIER_STATIC) {
+            switch ($node->name->toLowerString()) {
+                case '__construct':
+                    $this->emitError(new Error(
+                        sprintf('Constructor %s() cannot be static', $node->name),
+                        $this->getAttributesAt($modifierPos)));
+                    break;
+                case '__destruct':
+                    $this->emitError(new Error(
+                        sprintf('Destructor %s() cannot be static', $node->name),
+                        $this->getAttributesAt($modifierPos)));
+                    break;
+                case '__clone':
+                    $this->emitError(new Error(
+                        sprintf('Clone method %s() cannot be static', $node->name),
+                        $this->getAttributesAt($modifierPos)));
+                    break;
+            }
+        }
+    }
+
+    protected function checkClassConst(ClassConst $node, $modifierPos) {
+        if ($node->flags & Class_::MODIFIER_STATIC) {
+            $this->emitError(new Error(
+                "Cannot use 'static' as constant modifier",
+                $this->getAttributesAt($modifierPos)));
+        }
+        if ($node->flags & Class_::MODIFIER_ABSTRACT) {
+            $this->emitError(new Error(
+                "Cannot use 'abstract' as constant modifier",
+                $this->getAttributesAt($modifierPos)));
+        }
+        if ($node->flags & Class_::MODIFIER_FINAL) {
+            $this->emitError(new Error(
+                "Cannot use 'final' as constant modifier",
+                $this->getAttributesAt($modifierPos)));
+        }
+    }
+
+    protected function checkProperty(Property $node, $modifierPos) {
+        if ($node->flags & Class_::MODIFIER_ABSTRACT) {
+            $this->emitError(new Error('Properties cannot be declared abstract',
+                $this->getAttributesAt($modifierPos)));
+        }
+
+        if ($node->flags & Class_::MODIFIER_FINAL) {
+            $this->emitError(new Error('Properties cannot be declared final',
+                $this->getAttributesAt($modifierPos)));
+        }
+    }
+
+    protected function checkUseUse(UseUse $node, $namePos) {
+        if ($node->alias && $node->alias->isSpecialClassName()) {
+            $this->emitError(new Error(
+                sprintf(
+                    'Cannot use %s as %s because \'%2$s\' is a special class name',
+                    $node->name, $node->alias
+                ),
+                $this->getAttributesAt($namePos)
+            ));
+        }
+    }
+}