[PHP] PHP fails with no error

Question

Hi all. I am building a template parser. The template parser works like this:

• Tokenize (make for each part of the template code a token)
• Parse
  • Use my ParserHelper class. You can add rules for this system, and then it checks the token list for a valid grammar.
  • Add / change some tokens for extra functionality
• Compile (translate to php (for fast transforming to html))

The parser helper is a class with this structure:

• protected function parseRecursive(&$offset, $ruleName)
• protected function tryOption(&$offset, vdParserHelperRuleOption& $option)
• protected function tryItem(&$offset, vdParserHelperRuleOptionItem& $item, $count)

Offset stands for the token offset (so offset=0 means the first token to parse, etc.)

My parser helper rules have this structure:

• Rule
  • Options
    • Items

For the people how knows what a context free grammer is:

rule -> < option1 > | < option2 > | ... | < optionN >

with optionX is labda (empty option) or a list of:

• a 'rule link' (a link to an other rule (can be recursion)) or
• a 'token'

So the function parseRecursive calls tryOption, tryOption calls tryItem and tryItem can call parseRecursive agian.

The error is in the function tryItem:

...
// Try item
if($item->getType()==vdParserHelperRuleOptionItem::RuleLink){
    ///// The next line !!!!!!!!!!!!!
    if(!$this->parseRecursive($currentOffset, $item->getData())){
    ///// The previous line !!!!!!!!!

        return $item->isOptional();
    }
}else if($item->getType()==vdParserHelperRuleOptionItem::Type){
    ...
}
...

When I remove (replace it for if(true){ or so) the line between 'the' comments the php code is executed. But when I dont remove that line php dont execute my code and outputs nothing and I get no error at all. When I look in the apache log file I get this error:

[notice] child pid 11957 exit signal Segmentation fault (11)

Is this a fault in php, or can php not handle in-direct recursion? Or is it something else?

Answer 1

I'm sure this is an oversight in your code cleanup for posting, but you have an extra { that's not closed.