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PHP-Parser/lib/PhpParser/Lexer/Emulative.php
Nikita Popov bc21514ecf Move token constants into separate class
As these are shared between Php5 and Php7 parsers they should be
in some common place, otherwise we'd have to always reference either
one or the other.
2015-06-13 18:39:55 +02:00

206 lines
7.7 KiB
PHP

<?php
namespace PhpParser\Lexer;
use PhpParser\Parser\Tokens;
/**
* ATTENTION: This code is WRITE-ONLY. Do not try to read it.
*/
class Emulative extends \PhpParser\Lexer
{
protected $newKeywords;
protected $inObjectAccess;
const T_ELLIPSIS = 1001;
const T_POW = 1002;
const T_POW_EQUAL = 1003;
const T_COALESCE = 1004;
const T_SPACESHIP = 1005;
const T_YIELD_FROM = 1006;
const PHP_7_0 = '7.0.0dev';
const PHP_5_6 = '5.6.0rc1';
const PHP_5_5 = '5.5.0beta1';
public function __construct(array $options = array()) {
parent::__construct($options);
$newKeywordsPerVersion = array(
self::PHP_5_5 => array(
'finally' => Tokens::T_FINALLY,
'yield' => Tokens::T_YIELD,
),
);
$this->newKeywords = array();
foreach ($newKeywordsPerVersion as $version => $newKeywords) {
if (version_compare(PHP_VERSION, $version, '>=')) {
break;
}
$this->newKeywords += $newKeywords;
}
if (version_compare(PHP_VERSION, self::PHP_7_0, '>=')) {
return;
}
$this->tokenMap[self::T_COALESCE] = Tokens::T_COALESCE;
$this->tokenMap[self::T_SPACESHIP] = Tokens::T_SPACESHIP;
$this->tokenMap[self::T_YIELD_FROM] = Tokens::T_YIELD_FROM;
if (version_compare(PHP_VERSION, self::PHP_5_6, '>=')) {
return;
}
$this->tokenMap[self::T_ELLIPSIS] = Tokens::T_ELLIPSIS;
$this->tokenMap[self::T_POW] = Tokens::T_POW;
$this->tokenMap[self::T_POW_EQUAL] = Tokens::T_POW_EQUAL;
}
public function startLexing($code) {
$this->inObjectAccess = false;
$preprocessedCode = $this->preprocessCode($code);
parent::startLexing($preprocessedCode);
if ($preprocessedCode !== $code) {
$this->postprocessTokens();
}
// Set code property back to the original code, so __halt_compiler()
// handling and (start|end)FilePos attributes use the correct offsets
$this->code = $code;
}
/*
* Replaces new features in the code by ~__EMU__{NAME}__{DATA}__~ sequences.
* ~LABEL~ is never valid PHP code, that's why we can (to some degree) safely
* use it here.
* Later when preprocessing the tokens these sequences will either be replaced
* by real tokens or replaced with their original content (e.g. if they occurred
* inside a string, i.e. a place where they don't have a special meaning).
*/
protected function preprocessCode($code) {
if (version_compare(PHP_VERSION, self::PHP_7_0, '>=')) {
return $code;
}
$code = str_replace('??', '~__EMU__COALESCE__~', $code);
$code = str_replace('<=>', '~__EMU__SPACESHIP__~', $code);
$code = preg_replace_callback('(yield[ \n\r\t]+from)', function($matches) {
// Encoding $0 in order to preserve exact whitespace
return '~__EMU__YIELDFROM__' . bin2hex($matches[0]) . '__~';
}, $code);
if (version_compare(PHP_VERSION, self::PHP_5_6, '>=')) {
return $code;
}
$code = str_replace('...', '~__EMU__ELLIPSIS__~', $code);
$code = preg_replace('((?<!/)\*\*=)', '~__EMU__POWEQUAL__~', $code);
$code = preg_replace('((?<!/)\*\*(?!/))', '~__EMU__POW__~', $code);
return $code;
}
/*
* Replaces the ~__EMU__...~ sequences with real tokens or their original
* value.
*/
protected function postprocessTokens() {
// we need to manually iterate and manage a count because we'll change
// the tokens array on the way
for ($i = 0, $c = count($this->tokens); $i < $c; ++$i) {
// first check that the following tokens are of form ~LABEL~,
// then match the __EMU__... sequence.
if ('~' === $this->tokens[$i]
&& isset($this->tokens[$i + 2])
&& '~' === $this->tokens[$i + 2]
&& T_STRING === $this->tokens[$i + 1][0]
&& preg_match('(^__EMU__([A-Z]++)__(?:([A-Za-z0-9]++)__)?$)', $this->tokens[$i + 1][1], $matches)
) {
if ('ELLIPSIS' === $matches[1]) {
$replace = array(
array(self::T_ELLIPSIS, '...', $this->tokens[$i + 1][2])
);
} else if ('POW' === $matches[1]) {
$replace = array(
array(self::T_POW, '**', $this->tokens[$i + 1][2])
);
} else if ('POWEQUAL' === $matches[1]) {
$replace = array(
array(self::T_POW_EQUAL, '**=', $this->tokens[$i + 1][2])
);
} else if ('COALESCE' === $matches[1]) {
$replace = array(
array(self::T_COALESCE, '??', $this->tokens[$i + 1][2])
);
} else if ('SPACESHIP' === $matches[1]) {
$replace = array(
array(self::T_SPACESHIP, '<=>', $this->tokens[$i + 1][2]),
);
} else if ('YIELDFROM' === $matches[1]) {
$content = hex2bin($matches[2]);
$replace = array(
array(self::T_YIELD_FROM, $content, $this->tokens[$i + 1][2] - substr_count($content, "\n"))
);
} else {
throw new \RuntimeException('Invalid __EMU__ sequence');
}
array_splice($this->tokens, $i, 3, $replace);
$c -= 3 - count($replace);
// for multichar tokens (e.g. strings) replace any ~__EMU__...~ sequences
// in their content with the original character sequence
} elseif (is_array($this->tokens[$i])
&& 0 !== strpos($this->tokens[$i][1], '__EMU__')
) {
$this->tokens[$i][1] = preg_replace_callback(
'(~__EMU__([A-Z]++)__(?:([A-Za-z0-9]++)__)?~)',
array($this, 'restoreContentCallback'),
$this->tokens[$i][1]
);
}
}
}
/*
* This method is a callback for restoring EMU sequences in
* multichar tokens (like strings) to their original value.
*/
public function restoreContentCallback(array $matches) {
if ('ELLIPSIS' === $matches[1]) {
return '...';
} else if ('POW' === $matches[1]) {
return '**';
} else if ('POWEQUAL' === $matches[1]) {
return '**=';
} else if ('COALESCE' === $matches[1]) {
return '??';
} else if ('SPACESHIP' === $matches[1]) {
return '<=>';
} else if ('YIELDFROM' === $matches[1]) {
return hex2bin($matches[2]);
} else {
return $matches[0];
}
}
public function getNextToken(&$value = null, &$startAttributes = null, &$endAttributes = null) {
$token = parent::getNextToken($value, $startAttributes, $endAttributes);
// replace new keywords by their respective tokens. This is not done
// if we currently are in an object access (e.g. in $obj->namespace
// "namespace" stays a T_STRING tokens and isn't converted to T_NAMESPACE)
if (Tokens::T_STRING === $token && !$this->inObjectAccess) {
if (isset($this->newKeywords[strtolower($value)])) {
return $this->newKeywords[strtolower($value)];
}
} else {
// keep track of whether we currently are in an object access (after ->)
$this->inObjectAccess = Tokens::T_OBJECT_OPERATOR === $token;
}
return $token;
}
}