Mercurial > hg > isophonics-drupal-site
diff vendor/nikic/php-parser/lib/PhpParser/Lexer.php @ 0:4c8ae668cc8c
Initial import (non-working)
author | Chris Cannam |
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date | Wed, 29 Nov 2017 16:09:58 +0000 |
parents | |
children | 7a779792577d |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/vendor/nikic/php-parser/lib/PhpParser/Lexer.php Wed Nov 29 16:09:58 2017 +0000 @@ -0,0 +1,381 @@ +<?php + +namespace PhpParser; + +use PhpParser\Parser\Tokens; + +class Lexer +{ + protected $code; + protected $tokens; + protected $pos; + protected $line; + protected $filePos; + protected $prevCloseTagHasNewline; + + 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. + * + * This function does not throw if lexing errors occur. Instead, errors may be retrieved using + * the getErrors() method. + * + * @param string $code The source code to lex + * @param ErrorHandler|null $errorHandler Error handler to use for lexing errors. Defaults to + * ErrorHandler\Throwing + */ + public function startLexing($code, ErrorHandler $errorHandler = null) { + if (null === $errorHandler) { + $errorHandler = new ErrorHandler\Throwing(); + } + + $this->code = $code; // keep the code around for __halt_compiler() handling + $this->pos = -1; + $this->line = 1; + $this->filePos = 0; + + // If inline HTML occurs without preceding code, treat it as if it had a leading newline. + // This ensures proper composability, because having a newline is the "safe" assumption. + $this->prevCloseTagHasNewline = true; + + $scream = ini_set('xdebug.scream', '0'); + + $this->resetErrors(); + $this->tokens = @token_get_all($code); + $this->handleErrors($errorHandler); + + if (false !== $scream) { + ini_set('xdebug.scream', $scream); + } + } + + protected function resetErrors() { + if (function_exists('error_clear_last')) { + error_clear_last(); + } else { + // set error_get_last() to defined state by forcing an undefined variable error + set_error_handler(function() { return false; }, 0); + @$undefinedVariable; + restore_error_handler(); + } + } + + private function handleInvalidCharacterRange($start, $end, $line, ErrorHandler $errorHandler) { + for ($i = $start; $i < $end; $i++) { + $chr = $this->code[$i]; + if ($chr === 'b' || $chr === 'B') { + // HHVM does not treat b" tokens correctly, so ignore these + continue; + } + + if ($chr === "\0") { + // PHP cuts error message after null byte, so need special case + $errorMsg = 'Unexpected null byte'; + } else { + $errorMsg = sprintf( + 'Unexpected character "%s" (ASCII %d)', $chr, ord($chr) + ); + } + + $errorHandler->handleError(new Error($errorMsg, [ + 'startLine' => $line, + 'endLine' => $line, + 'startFilePos' => $i, + 'endFilePos' => $i, + ])); + } + } + + private function isUnterminatedComment($token) { + return ($token[0] === T_COMMENT || $token[0] === T_DOC_COMMENT) + && substr($token[1], 0, 2) === '/*' + && substr($token[1], -2) !== '*/'; + } + + private function errorMayHaveOccurred() { + if (defined('HHVM_VERSION')) { + // In HHVM token_get_all() does not throw warnings, so we need to conservatively + // assume that an error occurred + return true; + } + + $error = error_get_last(); + return null !== $error + && false === strpos($error['message'], 'Undefined variable'); + } + + protected function handleErrors(ErrorHandler $errorHandler) { + if (!$this->errorMayHaveOccurred()) { + return; + } + + // PHP's error handling for token_get_all() is rather bad, so if we want detailed + // error information we need to compute it ourselves. Invalid character errors are + // detected by finding "gaps" in the token array. Unterminated comments are detected + // by checking if a trailing comment has a "*/" at the end. + + $filePos = 0; + $line = 1; + foreach ($this->tokens as $i => $token) { + $tokenValue = \is_string($token) ? $token : $token[1]; + $tokenLen = \strlen($tokenValue); + + if (substr($this->code, $filePos, $tokenLen) !== $tokenValue) { + // Something is missing, must be an invalid character + $nextFilePos = strpos($this->code, $tokenValue, $filePos); + $this->handleInvalidCharacterRange( + $filePos, $nextFilePos, $line, $errorHandler); + $filePos = $nextFilePos; + } + + $filePos += $tokenLen; + $line += substr_count($tokenValue, "\n"); + } + + if ($filePos !== \strlen($this->code)) { + if (substr($this->code, $filePos, 2) === '/*') { + // Unlike PHP, HHVM will drop unterminated comments entirely + $comment = substr($this->code, $filePos); + $errorHandler->handleError(new Error('Unterminated comment', [ + 'startLine' => $line, + 'endLine' => $line + substr_count($comment, "\n"), + 'startFilePos' => $filePos, + 'endFilePos' => $filePos + \strlen($comment), + ])); + + // Emulate the PHP behavior + $isDocComment = isset($comment[3]) && $comment[3] === '*'; + $this->tokens[] = [$isDocComment ? T_DOC_COMMENT : T_COMMENT, $comment, $line]; + } else { + // Invalid characters at the end of the input + $this->handleInvalidCharacterRange( + $filePos, \strlen($this->code), $line, $errorHandler); + } + return; + } + + if (count($this->tokens) > 0) { + // Check for unterminated comment + $lastToken = $this->tokens[count($this->tokens) - 1]; + if ($this->isUnterminatedComment($lastToken)) { + $errorHandler->handleError(new Error('Unterminated comment', [ + 'startLine' => $line - substr_count($lastToken[1], "\n"), + 'endLine' => $line, + 'startFilePos' => $filePos - \strlen($lastToken[1]), + 'endFilePos' => $filePos, + ])); + } + } + } + + /** + * 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]]; + if (T_CLOSE_TAG === $token[0]) { + $this->prevCloseTagHasNewline = false !== strpos($token[1], "\n"); + } else if (T_INLINE_HTML === $token[0]) { + $startAttributes['hasLeadingNewline'] = $this->prevCloseTagHasNewline; + } + + $this->line += substr_count($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; + } +}