<?php declare(strict_types=1);
namespace PhpParser\Lexer;
use PhpParser\Error;
use PhpParser\ErrorHandler;
class Emulative extends \PhpParser\Lexer
{
const PHP_7_3 = '7.3.0dev';
/**
* @var array Patches used to reverse changes introduced in the code
*/
private $patches;
public function startLexing(string $code, ErrorHandler $errorHandler = null) {
$this->patches = [];
$preparedCode = $this->prepareCode($code);
if (null === $preparedCode) {
// Nothing to emulate, yay
parent::startLexing($code, $errorHandler);
return;
}
$collector = new ErrorHandler\Collecting();
parent::startLexing($preparedCode, $collector);
$this->fixupTokens();
$errors = $collector->getErrors();
if (!empty($errors)) {
$this->fixupErrors($errors);
foreach ($errors as $error) {
$errorHandler->handleError($error);
}
}
}
/**
* Prepares code for emulation. If nothing has to be emulated null is returned.
*
* @param string $code
* @return null|string
*/
private function prepareCode(string $code) {
if (version_compare(\PHP_VERSION, self::PHP_7_3, '>=')) {
return null;
}
if (strpos($code, '<<<') === false) {
// Definitely doesn't contain heredoc/nowdoc
return null;
}
$flexibleDocStringRegex = <<<'REGEX'
/<<<[ \t]*(['"]?)([a-zA-Z_\x80-\xff][a-zA-Z0-9_\x80-\xff]*)\1\r?\n
(?:.*\r?\n)*?
(?<indentation>\h*)\2(?![a-zA-Z_\x80-\xff])(?<separator>(?:;?[\r\n])?)/x
REGEX;
if (!preg_match_all($flexibleDocStringRegex, $code, $matches, PREG_SET_ORDER|PREG_OFFSET_CAPTURE)) {
// No heredoc/nowdoc found
return null;
}
// Keep track of how much we need to adjust string offsets due to the modifications we
// already made
$posDelta = 0;
foreach ($matches as $match) {
$indentation = $match['indentation'][0];
$indentationStart = $match['indentation'][1];
$separator = $match['separator'][0];
$separatorStart = $match['separator'][1];
if ($indentation === '' && $separator !== '') {
// Ordinary heredoc/nowdoc
continue;
}
if ($indentation !== '') {
// Remove indentation
$indentationLen = strlen($indentation);
$code = substr_replace($code, '', $indentationStart + $posDelta, $indentationLen);
$this->patches[] = [$indentationStart + $posDelta, 'add', $indentation];
$posDelta -= $indentationLen;
}
if ($separator === '') {
// Insert newline as separator
$code = substr_replace($code, "\n", $separatorStart + $posDelta, 0);
$this->patches[] = [$separatorStart + $posDelta, 'remove', "\n"];
$posDelta += 1;
}
}
if (empty($this->patches)) {
// We did not end up emulating anything
return null;
}
return $code;
}
private function fixupTokens() {
assert(count($this->patches) > 0);
// Load first patch
$patchIdx = 0;
list($patchPos, $patchType, $patchText) = $this->patches[$patchIdx];
// We use a manual loop over the tokens, because we modify the array on the fly
$pos = 0;
for ($i = 0, $c = \count($this->tokens); $i < $c; $i++) {
$token = $this->tokens[$i];
if (\is_string($token)) {
// We assume that patches don't apply to string tokens
$pos += \strlen($token);
continue;
}
$len = \strlen($token[1]);
$posDelta = 0;
while ($patchPos >= $pos && $patchPos < $pos + $len) {
$patchTextLen = \strlen($patchText);
if ($patchType === 'remove') {
if ($patchPos === $pos && $patchTextLen === $len) {
// Remove token entirely
array_splice($this->tokens, $i, 1, []);
$i--;
$c--;
} else {
// Remove from token string
$this->tokens[$i][1] = substr_replace(
$token[1], '', $patchPos - $pos + $posDelta, $patchTextLen
);
$posDelta -= $patchTextLen;
}
} elseif ($patchType === 'add') {
// Insert into the token string
$this->tokens[$i][1] = substr_replace(
$token[1], $patchText, $patchPos - $pos + $posDelta, 0
);
$posDelta += $patchTextLen;
} else {
assert(false);
}
// Fetch the next patch
$patchIdx++;
if ($patchIdx >= \count($this->patches)) {
// No more patches, we're done
return;
}
list($patchPos, $patchType, $patchText) = $this->patches[$patchIdx];
// Multiple patches may apply to the same token. Reload the current one to check
// If the new patch applies
$token = $this->tokens[$i];
}
$pos += $len;
}
// A patch did not apply
assert(false);
}
/**
* Fixup line and position information in errors.
*
* @param Error[] $errors
*/
private function fixupErrors(array $errors) {
foreach ($errors as $error) {
$attrs = $error->getAttributes();
$posDelta = 0;
$lineDelta = 0;
foreach ($this->patches as $patch) {
list($patchPos, $patchType, $patchText) = $patch;
if ($patchPos >= $attrs['startFilePos']) {
// No longer relevant
break;
}
if ($patchType === 'add') {
$posDelta += strlen($patchText);
$lineDelta += substr_count($patchText, "\n");
} else {
$posDelta -= strlen($patchText);
$lineDelta -= substr_count($patchText, "\n");
}
}
$attrs['startFilePos'] += $posDelta;
$attrs['endFilePos'] += $posDelta;
$attrs['startLine'] += $lineDelta;
$attrs['endLine'] += $lineDelta;
$error->setAttributes($attrs);
}
}
}