Viewing file:  Lexer.php (10.43 KB) -rw-r--r--
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<?php
namespace PhpParser;
use PhpParser\Node\Scalar\LNumber;
use PhpParser\Parser\Tokens;
class Lexer
{
protected $code;
protected $tokens;
protected $pos;
protected $line;
protected $filePos;
protected $tokenMap;
protected $dropTokens;
protected $usedAttributes;
/**
* Creates a Lexer.
*
* @param array $options Options array. Currently only the 'usedAttributes' option is supported,
* which is an array of attributes to add to the AST nodes. Possible
* attributes are: 'comments', 'startLine', 'endLine', 'startTokenPos',
* 'endTokenPos', 'startFilePos', 'endFilePos'. The option defaults to the
* first three. For more info see getNextToken() docs.
*/
public function __construct(array $options = array()) {
// map from internal tokens to PhpParser tokens
$this->tokenMap = $this->createTokenMap();
// map of tokens to drop while lexing (the map is only used for isset lookup,
// that's why the value is simply set to 1; the value is never actually used.)
$this->dropTokens = array_fill_keys(
array(T_WHITESPACE, T_OPEN_TAG, T_COMMENT, T_DOC_COMMENT), 1
);
// the usedAttributes member is a map of the used attribute names to a dummy
// value (here "true")
$options += array(
'usedAttributes' => array('comments', 'startLine', 'endLine'),
);
$this->usedAttributes = array_fill_keys($options['usedAttributes'], true);
}
/**
* Initializes the lexer for lexing the provided source code.
*
* @param string $code The source code to lex
*
* @throws Error on lexing errors (unterminated comment or unexpected character)
*/
public function startLexing($code) {
$scream = ini_set('xdebug.scream', '0');
$this->resetErrors();
$this->tokens = @token_get_all($code);
$this->handleErrors();
if (false !== $scream) {
ini_set('xdebug.scream', $scream);
}
$this->code = $code; // keep the code around for __halt_compiler() handling
$this->pos = -1;
$this->line = 1;
$this->filePos = 0;
}
protected function resetErrors() {
if (function_exists('error_clear_last')) {
error_clear_last();
} else {
// set error_get_last() to defined state by forcing an undefined variable error
set_error_handler(function() { return false; }, 0);
@$undefinedVariable;
restore_error_handler();
}
}
protected function handleErrors() {
$error = error_get_last();
if (null === $error) {
return;
}
if (preg_match(
'~^Unterminated comment starting line ([0-9]+)$~',
$error['message'], $matches
)) {
throw new Error('Unterminated comment', (int) $matches[1]);
}
if (preg_match(
'~^Unexpected character in input: \'(.)\' \(ASCII=([0-9]+)\)~s',
$error['message'], $matches
)) {
throw new Error(sprintf(
'Unexpected character "%s" (ASCII %d)',
$matches[1], $matches[2]
));
}
// PHP cuts error message after null byte, so need special case
if (preg_match('~^Unexpected character in input: \'$~', $error['message'])) {
throw new Error('Unexpected null byte');
}
}
/**
* Fetches the next token.
*
* The available attributes are determined by the 'usedAttributes' option, which can
* be specified in the constructor. The following attributes are supported:
*
* * 'comments' => Array of PhpParser\Comment or PhpParser\Comment\Doc instances,
* representing all comments that occurred between the previous
* non-discarded token and the current one.
* * 'startLine' => Line in which the node starts.
* * 'endLine' => Line in which the node ends.
* * 'startTokenPos' => Offset into the token array of the first token in the node.
* * 'endTokenPos' => Offset into the token array of the last token in the node.
* * 'startFilePos' => Offset into the code string of the first character that is part of the node.
* * 'endFilePos' => Offset into the code string of the last character that is part of the node.
*
* @param mixed $value Variable to store token content in
* @param mixed $startAttributes Variable to store start attributes in
* @param mixed $endAttributes Variable to store end attributes in
*
* @return int Token id
*/
public function getNextToken(&$value = null, &$startAttributes = null, &$endAttributes = null) {
$startAttributes = array();
$endAttributes = array();
while (1) {
if (isset($this->tokens[++$this->pos])) {
$token = $this->tokens[$this->pos];
} else {
// EOF token with ID 0
$token = "\0";
}
if (isset($this->usedAttributes['startLine'])) {
$startAttributes['startLine'] = $this->line;
}
if (isset($this->usedAttributes['startTokenPos'])) {
$startAttributes['startTokenPos'] = $this->pos;
}
if (isset($this->usedAttributes['startFilePos'])) {
$startAttributes['startFilePos'] = $this->filePos;
}
if (\is_string($token)) {
$value = $token;
if (isset($token[1])) {
// bug in token_get_all
$this->filePos += 2;
$id = ord('"');
} else {
$this->filePos += 1;
$id = ord($token);
}
} elseif (!isset($this->dropTokens[$token[0]])) {
$value = $token[1];
$id = $this->tokenMap[$token[0]];
$this->line += substr_count($value, "\n");
$this->filePos += \strlen($value);
} else {
if (T_COMMENT === $token[0] || T_DOC_COMMENT === $token[0]) {
if (isset($this->usedAttributes['comments'])) {
$comment = T_DOC_COMMENT === $token[0]
? new Comment\Doc($token[1], $this->line, $this->filePos)
: new Comment($token[1], $this->line, $this->filePos);
$startAttributes['comments'][] = $comment;
}
}
$this->line += substr_count($token[1], "\n");
$this->filePos += \strlen($token[1]);
continue;
}
if (isset($this->usedAttributes['endLine'])) {
$endAttributes['endLine'] = $this->line;
}
if (isset($this->usedAttributes['endTokenPos'])) {
$endAttributes['endTokenPos'] = $this->pos;
}
if (isset($this->usedAttributes['endFilePos'])) {
$endAttributes['endFilePos'] = $this->filePos - 1;
}
return $id;
}
throw new \RuntimeException('Reached end of lexer loop');
}
/**
* Returns the token array for current code.
*
* The token array is in the same format as provided by the
* token_get_all() function and does not discard tokens (i.e.
* whitespace and comments are included). The token position
* attributes are against this token array.
*
* @return array Array of tokens in token_get_all() format
*/
public function getTokens() {
return $this->tokens;
}
/**
* Handles __halt_compiler() by returning the text after it.
*
* @return string Remaining text
*/
public function handleHaltCompiler() {
// text after T_HALT_COMPILER, still including ();
$textAfter = substr($this->code, $this->filePos);
// ensure that it is followed by ();
// this simplifies the situation, by not allowing any comments
// in between of the tokens.
if (!preg_match('~^\s*\(\s*\)\s*(?:;|\?>\r?\n?)~', $textAfter, $matches)) {
throw new Error('__HALT_COMPILER must be followed by "();"');
}
// prevent the lexer from returning any further tokens
$this->pos = count($this->tokens);
// return with (); removed
return (string) substr($textAfter, strlen($matches[0])); // (string) converts false to ''
}
/**
* Creates the token map.
*
* The token map maps the PHP internal token identifiers
* to the identifiers used by the Parser. Additionally it
* maps T_OPEN_TAG_WITH_ECHO to T_ECHO and T_CLOSE_TAG to ';'.
*
* @return array The token map
*/
protected function createTokenMap() {
$tokenMap = array();
// 256 is the minimum possible token number, as everything below
// it is an ASCII value
for ($i = 256; $i < 1000; ++$i) {
if (T_DOUBLE_COLON === $i) {
// T_DOUBLE_COLON is equivalent to T_PAAMAYIM_NEKUDOTAYIM
$tokenMap[$i] = Tokens::T_PAAMAYIM_NEKUDOTAYIM;
} elseif(T_OPEN_TAG_WITH_ECHO === $i) {
// T_OPEN_TAG_WITH_ECHO with dropped T_OPEN_TAG results in T_ECHO
$tokenMap[$i] = Tokens::T_ECHO;
} elseif(T_CLOSE_TAG === $i) {
// T_CLOSE_TAG is equivalent to ';'
$tokenMap[$i] = ord(';');
} elseif ('UNKNOWN' !== $name = token_name($i)) {
if ('T_HASHBANG' === $name) {
// HHVM uses a special token for #! hashbang lines
$tokenMap[$i] = Tokens::T_INLINE_HTML;
} else if (defined($name = 'PhpParser\Parser\Tokens::' . $name)) {
// Other tokens can be mapped directly
$tokenMap[$i] = constant($name);
}
}
}
// HHVM uses a special token for numbers that overflow to double
if (defined('T_ONUMBER')) {
$tokenMap[T_ONUMBER] = Tokens::T_DNUMBER;
}
// HHVM also has a separate token for the __COMPILER_HALT_OFFSET__ constant
if (defined('T_COMPILER_HALT_OFFSET')) {
$tokenMap[T_COMPILER_HALT_OFFSET] = Tokens::T_STRING;
}
return $tokenMap;
}
}
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