Debug PHP extensions using gdb

Source: Internet
Author: User
Tags zts
Debug PHP extensions using gdb

From: http://www.codefrom.com/paper/%E4%BD%BF%E7%94%A8gdb%E8%B0%83%E8%AF%95p...

Php extensions are developed using c/c ++ and can be easily debugged using gdb. The procedure is as follows:
Add the ** -- enable-debug ** parameter when compiling php.

./configure --enable-debugmake && make install

Tested on my ubuntu machine, the extended directory defaults to/usr/local/lib/php/extensions/debug-non-zts-20131226/
In this way, php source code debugging is also very convenient.
Next, create extension, go to the ext Directory of the php source code, and run

./ext_skel --extname=mydebug  

The current directory is automatically generated.MydebugDirectory, enter the directory, and editConfig. m4File, remove 10 ~ 12 rows of dnl, as shown below

PHP_ARG_WITH(mydebug, for mydebug support,Make sure that the comment is aligned:[  --with-mydebug             Include mydebug support])

Add

if test -z "$PHP_DEBUG"; then        AC_ARG_ENABLE(debug,                [--enable-debg  compile with debugging system],                [PHP_DEBUG=$enableval], [PHP_DEBUG=no]        )fi

This indicates that the extension can be debugged, then the extension is compiled, and the command is used.

phpize ./configure --enable-debugmake && make install

The phpize and php-config here need to configure the environment variables in advance and then load the extension. The address above my machine is/usr/local/lib/php/extensions/debug-non-zts-20131226 /. Go to the mydebug extension source code directory. the default generated function is confirm_mydebug_compiled, which is defined in mydebug. c. the automatically generated function is extended.

PHP_FUNCTION(confirm_mydebug_compiled){        char *arg = NULL;        int arg_len, len;        char *strg;        if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "s", &arg, &arg_len) == FAILURE) {                return;        }        len = spprintf(&strg, 0, "Congratulations! You have successfully modified ext/%.78s/config.m4. Module %.78s is now compiled into PHP.", "mydebug", arg);        RETURN_STRINGL(strg, len, 0);}

Obtain the string parameters and combine them into a string to return the result. Run the nm command to view the generated mydebug. so exported symbol.

Run nm mydebug. so and return zif_confirm_mydebug_compiled ......

PHP_FUNCTION is actually adding zif _ before the function name, and then performing gdb debugging

Step 1: run gdb php and then run: break zif_confirm_mydebug_compiled terminal prompt: Function "zif_confirm_mydebug_compiled" not defined. Make breakpoint pending on future shared library load? (Y or [n]) input: y input: run/tmp/test. php will echo: Breakpoint 1, timeout (ht = 1, return_value = 0xb7bf0d44, return_value_ptr = 0xb7bd6104, this_ptr = 0x0, return_value_used = 1) /..... /php-5.6.6/ext/mydebug. c: 56 then input: l Display: 54 PHP_FUNCTION (confirm_mydebug_compiled) 55 {56 char * arg = NULL; 57 int arg_len, len; 58 char * strg; 5960 if (zend_parse_parameters (ZEND_NUM_ARGS () TSRMLS_CC, "s", & arg, & arg_len) = FAILURE ){

The file/tmp/test. php contains the following content:

   

As you can see, the function source code has come out and can be debugged using the commonly used gdb command.

More exciting original content into http://www.codefrom.com/

Related Article

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.