Parser crashes when encountering property call inside string

[nevadascout]

So I have some code: echo "test: $this->prop->foo".

When trying to parse this code, the parser crashes without an error, however adding { } around the property call resolves the issue and it parses successfully.

So echo "test: {$this->prop->foo}" works.

Even if this behaviour is not allowed in PHP, the parser should throw an exception so it can be caught on the user side. Currently this code crashes my application without warning, regardless if I use a try/catch block or not.

[ichiriac]

Hi @nevadascout,

Seems to work with this :

Z:\php-parser\bin>node test.js -e "echo ""test: $this->prop"""

*** START TESTING ***

-- TOKENS :
T_ECHO " T_ENCAPSED_AND_WHITESPACE T_VARIABLE T_OBJECT_OPERATOR T_STRING "
-- AST :
[ 'program',
  [ [ 'sys',
      'echo',
      [ [ 'bin',
          '.',
          [ 'string', 'test: ' ],
          [ 'prop', [ 'var', '$this' ], [ 'string', 'prop' ] ] ] ] ] ] ]

But not with this :

Z:\php-parser\bin>node test.js -e "echo ""test: $this->prop->foo"""

*** START TESTING ***

-- TOKENS :
T_ECHO " T_ENCAPSED_AND_WHITESPACE T_VARIABLE T_OBJECT_OPERATOR T_STRING T_OBJECT_OPERATOR T_STRING "
Z:\php-parser\src\parser.js:218
        throw new Error(this.lastError.message);
              ^
Error: Parse Error : unexpected T_OBJECT_OPERATOR, expecting T_VARIABLE, T_CURLY_OPEN, T_DOLLAR_OPEN_CURLY_BRACES, T_ENCAPSED_AND_WHITESPACE at line 1
    at Object.api.error (Z:\php-parser\src\parser.js:218:15)
    at Object.api.expect (Z:\php-parser\src\parser.js:319:18)
    at Object.read_encapsed_string_item (Z:\php-parser\src\parser\scalar.js:142:14)
    at Object.read_encapsed_string (Z:\php-parser\src\parser\scalar.js:171:39)
    at Object.read_scalar (Z:\php-parser\src\parser\scalar.js:54:32)
    at Object.read_expr_item (Z:\php-parser\src\parser\expr.js:270:21)
    at Object.read_expr (Z:\php-parser\src\parser\expr.js:12:23)
    at Object.api.read_list (Z:\php-parser\src\parser.js:375:28)
    at Object.read_statement (Z:\php-parser\src\parser\statement.js:187:35)
    at Object.read_top_statement (Z:\php-parser\src\parser\statement.js:60:23)

It should pass and I'll fix it, but for me the error behaviour is normal, it's throwing an syntax error as expected. I can't reproduce the same crash error, could you isolate this behaviour in a self-contained js file ?

[nevadascout]

Hey thanks for the quick response, I just realised that my example was wrong.

It should have been echo "test: $this->foo->prop"

[ichiriac]

ok, i've got it, my implementation of this grammar was too simplified :
https://github.com/php/php-src/blob/493524454d66adde84e00d249d607ecd540de99f/Zend/zend_language_parser.y#L1228

[nevadascout]

Great! How easy is it to fix?

[ichiriac]

it's easy, but i wait that travis do it's job :
https://travis-ci.org/glayzzle/php-parser/builds/138464108

Since I've validate tokens over php7 I'm compiling php from sources and it takes a long time but I'm confident it will pass

[ichiriac]

I'm re-openning this issue until we figure out the crash error

[nevadascout]

I'll get you a code sample shortly

[ichiriac]

😂 build ✅ : https://travis-ci.org/glayzzle/php-parser/builds/138482518

[nevadascout]

Nice one! Do you still want a sample of broken code?

[ichiriac]

No, it's ok, maybe it's a problem with the silent error handler, if so it's not about encapsed strings parsing.

If you get another parsing problem with a crash you could open another issue.

I will close this issue, thanks for your reporting,

Best Regards,
Ioan

[nevadascout]

Thanks for fixing it so quickly!