Deliverer, the savior of PHP's ancestral code, here comes!

A few days ago, a group friend took over a piece of ancestral code. The investigation has not been solved for a long time. He is ready to take the bucket and run away, and finally help him solve it. For the complete process, see https://mengkang.net/1470.html but the final code location I have some based on personal experience that the actual calling link is different from what I expected. It is all based on guessing. I didn't see the complete call chain, so I thought I needed a tool to assist in the clear query of the entire call chain.

160d42d851e520 so I made such a tool, mainly for some unfamiliar projects, and the daily environment is not

deliverer Ancestral Code https://github.com/zhoumengkang/deliverer

If your project is not that bad and the daily environment is ok, then the best way to get familiar with a project is xdebug. This tool is mainly to troubleshoot online problems.
Similar tools are 360's phptrace. The implementation principle is slightly different.

function points

• can be filtered according to 160d42d851e68b function name, class name, method name, route
• You can exit after querying the specified filtering content n times
• You can take a closer look at the entire call chain according to the request id playback
• The filtered content will be highlighted
• If the call stack is deeper, you can specify -l to hide the display of deep calls

principle

In fact, it is relatively simple, divided into two steps, the first step is to collect logs, and the second step is to analyze the logs.

first step

In PHP_MINIT stage, by zend_set_user_opcode_handler to set ZEND_DO_UCALL , ZEND_DO_FCALL_BY_NAME , ZEND_DO_FCALL three opcode processing and analysis.

Note that it will cover some built-in functions and method calls, and we can filter by type.

Then create a new log file in the PHP_RINIT stage and write the requested information

pid-ts sapi http_method http_url

Print the call stack information in the custom handler during the request

Finally, close the log file writing PHP_RSHUTDOWN

Second step

bin/deliverer to analyze and sort the collected logs. This is a php script, so I won’t go into details.

Install and use

Compile

$ phpize
$ ./configure --with-php-config=/usr/local/php/bin/php-config
$ make && sudo make install

Configure php.ini

Append

[deliverer]
extension=deliverer.so

Restart php-fpm

sudo service php-fpm restart

Use analysis tools

You can move ./bin/deliverer to the directory you think is appropriate, if in the current directory

$ chmod +x deliverer

Run with a piece of my own ancestral code long ago (my blog)

$ ./bin/deliverer -t

This will always monitor the execution of all php processes

$ ./bin/deliverer -tAction::initUser -n3 -l5




parameter	value	Explanation
-t	Action::initUser	Filter the requests that contain the call
-n	3	Count three times and then exit
-l	5	Function (method) call depth display, up to 5 levels are displayed, the excess part is marked at the end

$ ./bin/deliverer -v7979-1624369150991941

View the complete call stack in detail through -v requestId

$ ./bin/deliverer -tSqlExecute::getAll -n1 -l3

When a method is to be queried, the function call stack is too deep and not within the scope of the hierarchical query, the outer call is displayed in red