【php】使用gdb调试php程序

àì夳堔傛蜴生んèń 2023-10-05 16:25 1阅读 0赞

#### 1、简介 ####

GDB是GNU开源组织发布的一个强大的UNIX下的程序调试工具。如果你是在 UNIX平台下做软件，你会发现GDB这个调试工具有比VC、BCB的图形化调试器更强大的功能。同时GDB也具有例如ddd这样的图形化的调试端

#### 2、调试C/C++程序 ####

直接上代码了

编译

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 <td> 1 </td> 
 <td> <code>g++ k.cpp -g -Wall -Werror -o main</code> </td> 
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</table>

开始调试

设置断点 break linenumber

<table> 
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 <td> 1 2 3 4 5 6 7 8 </td> 
 <td> <code>(gdb) b 9</code> <code>Breakpoint 1 at 0x80486f9: file k.cpp, line 9.</code> <code>(gdb) r</code> <code>Starting program: /code/main</code> <code>4</code> &nbsp; <code>Breakpoint 1, main () at k.cpp:9</code> <code>9&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>long</code>&nbsp;<code>val=factorial(n);</code> </td> 
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设置观察点 watch var

<table> 
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 <td> 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 </td> 
 <td> <code>(gdb) s</code> <code>factorial (n=4) at k.cpp:17</code> <code>17&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>long</code>&nbsp;<code>result(1);</code> <code>(gdb) l</code> <code>12&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>return</code>&nbsp;<code>0;</code> <code>13&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; }</code> <code>14</code> <code>15&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>long</code>&nbsp;<code>factorial(</code><code>int</code>&nbsp;<code>n)</code> <code>16&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; { </code> <code>17&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>long</code>&nbsp;<code>result(1);</code> <code>18&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>while</code><code>(n--)</code> <code>19&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; { </code> <code>20&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; result*=n;</code> <code>21&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; }</code> <code>(gdb) watch n</code> <code>Hardware watchpoint 2: n</code> <code>(gdb) watch result</code> <code>Hardware watchpoint 3: result</code> <code>(gdb) c</code> <code>Continuing.</code> <code>Hardware watchpoint 3: result</code> &nbsp; <code>Old value = 0</code> <code>New value = 1</code> <code>factorial (n=4) at k.cpp:18</code> <code>18&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>while</code><code>(n--)</code> <code>(gdb)</code> <code>Continuing.</code> <code>Hardware watchpoint 2: n</code> &nbsp; <code>Old value = 4</code> <code>New value = 3</code> <code>0x08048764 in factorial (n=3) at k.cpp:18</code> <code>18&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>while</code><code>(n--)</code> <code>(gdb)</code> <code>Continuing.</code> <code>Hardware watchpoint 3: result</code> &nbsp; <code>Old value = 1</code> <code>New value = 3</code> <code>factorial (n=3) at k.cpp:18</code> <code>18&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>while</code><code>(n--)</code> <code>(gdb)</code> <code>Continuing.</code> <code>Hardware watchpoint 2: n</code> &nbsp; <code>Old value = 3</code> <code>New value = 2</code> <code>0x08048764 in factorial (n=2) at k.cpp:18</code> <code>18&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>while</code><code>(n--)</code> <code>(gdb)</code> <code>Continuing.</code> <code>Hardware watchpoint 3: result</code> &nbsp; <code>Old value = 3</code> <code>New value = 6</code> <code>factorial (n=2) at k.cpp:18</code> <code>18&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>while</code><code>(n--)</code> <code>(gdb)</code> <code>Continuing.</code> <code>Hardware watchpoint 2: n</code> &nbsp; <code>Old value = 2</code> <code>New value = 1</code> <code>0x08048764 in factorial (n=1) at k.cpp:18</code> <code>18&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>while</code><code>(n--)</code> <code>(gdb)</code> <code>Continuing.</code> <code>Hardware watchpoint 2: n</code> &nbsp; <code>Old value = 1</code> <code>New value = 0</code> <code>0x08048764 in factorial (n=0) at k.cpp:18</code> <code>18&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>while</code><code>(n--)</code> <code>(gdb)</code> <code>Continuing.</code> &nbsp; <code>Watchpoint 2 deleted because the program has left the block in</code> <code>which its expression is valid.</code> &nbsp; <code>Watchpoint 3 deleted because the program has left the block in</code> <code>which its expression is valid.</code> <code>0x08048705 in main () at k.cpp:9</code> <code>9&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>long</code>&nbsp;<code>val=factorial(n);</code> <code>(gdb) p val</code> <code>$1 = 11476980</code> <code>(gdb)</code> </td> 
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</table>

可以看到是while那里，导致n越界了，fix

<table> 
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 <td> 1 2 3 4 5 </td> 
 <td> <code>while</code><code>(n&gt;0)&nbsp;</code><code>//doesn't let n reach 0</code> <code>{ </code> <code>&nbsp;&nbsp;</code><code>result*=n;</code> <code>&nbsp;&nbsp;</code><code>n--;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>//decrements only after the evaluation</code> <code>}</code> </td> 
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</table>

一些快捷命令

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 <td> 1 2 3 4 5 6 7 8 9 </td> 
 <td> <code>l – list</code> <code>p – print print {variable}</code> <code>c –&nbsp;</code><code>continue</code> <code>s – step</code> <code>b -&nbsp;</code><code>break</code>&nbsp;&nbsp;<code>break</code>&nbsp;<code>line_number/</code><code>break</code>&nbsp;<code>[file_name]:line_number/</code><code>break</code>&nbsp;<code>[file_name]:func_name</code> <code>r - run</code> <code>set &lt;var&gt; = &lt;value&gt;</code> <code>watch &lt;var&gt;</code> <code>ENTER: pressing enter key would execute the previously executed command again.</code> </td> 
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c/n/s的区别

*  c or continue: Debugger will continue executing until the next break point.
 *  n or next: Debugger will execute the next line as single instruction.
 *  s or step: Same as next, but does not treats function as a single instruction, instead goes into the function and executes it line by line

#### 3、调试PHP程序 ####

PHP代码

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 <td> 1 2 3 4 5 6 7 8 9 10 </td> 
 <td> <code>&lt;?php.&nbsp;&nbsp;</code> <code>for</code><code>($i = 0; $i &lt; 10; $i++){ </code> <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>echo $i.</code><code>"\n"</code><code>;</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>sleep(3);</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>if</code><code>(in_array($i,[1,9,20])){ </code> <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>print_r($i*$i);</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>var_dump($i*$i);&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>print $i*$i;</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>}&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code> <code>}</code> </td> 
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</table>

开始调试，加上断点

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 <td> 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 </td> 
 <td> <code>[root@localhost code]# gdb php&nbsp;&nbsp;&nbsp;</code> <code>GNU gdb (GDB) Red Hat Enterprise Linux (7.2-83.el6)</code> <code>Copyright (C) 2010 Free Software Foundation, Inc.</code> <code>License GPLv3+: GNU GPL version 3 or later &lt;http:</code><code>//gnu.org/licenses/gpl.html&gt;</code> <code>This is&nbsp;</code><code>free</code>&nbsp;<code>software: you are&nbsp;</code><code>free</code>&nbsp;<code>to change and redistribute it.</code> <code>There is NO WARRANTY, to the extent permitted by law.&nbsp; Type&nbsp;</code><code>"show copying"</code> <code>and&nbsp;</code><code>"show warranty"</code>&nbsp;<code>for</code>&nbsp;<code>details.</code> <code>This GDB was configured as&nbsp;</code><code>"i686-redhat-linux-gnu"</code><code>.</code> <code>For bug reporting instructions, please see:</code> <code>&lt;http:</code><code>//www.gnu.org/software/gdb/bugs/&gt;...</code> <code>Reading symbols from /usr/bin/php...done.</code> <code>(gdb) b zif_sleep</code> <code>Breakpoint 1 at 0x8435180: file /usr/local/src/php-5.5.23/ext/standard/basic_functions.c, line 4449.</code> <code>(gdb) b zif_in_array</code> <code>Breakpoint 2 at 0x8426923: file /usr/local/src/php-5.5.23/ext/standard/array.c, line 1215.</code> <code>(gdb) b zif_print_r</code> <code>Breakpoint 3 at 0x8438273: file /usr/local/src/php-5.5.23/ext/standard/basic_functions.c, line 5553.</code> <code>(gdb) b zif_var_dump</code> <code>Breakpoint 4 at 0x847d296: file /usr/local/src/php-5.5.23/ext/standard/var.c, line 178.</code> <code>(gdb) b zif_printf</code> <code>Function&nbsp;</code><code>"zif_printf"</code>&nbsp;<code>not defined.</code> <code>Make breakpoint pending on future shared library load? (y or [n]) n</code> <code>(gdb) b zif_sprintf</code> <code>Function&nbsp;</code><code>"zif_sprintf"</code>&nbsp;<code>not defined.</code> <code>Make breakpoint pending on future shared library load? (y or [n]) n</code> <code>(gdb) b&nbsp;</code><code>printf</code> <code>Breakpoint 5 at 0x806a390</code> <code>(gdb) b&nbsp;</code><code>memcpy</code> <code>Breakpoint 6 at 0x8069390</code> <code>(gdb) b zif_print</code> <code>Function&nbsp;</code><code>"zif_print"</code>&nbsp;<code>not defined.</code> <code>Make breakpoint pending on future shared library load? (y or [n]) n</code> <code>(gdb) b zif_echo</code> <code>Function&nbsp;</code><code>"zif_echo"</code>&nbsp;<code>not defined.</code> <code>Make breakpoint pending on future shared library load? (y or [n]) n</code> <code>(gdb) info b</code> <code>Num&nbsp;&nbsp;&nbsp;&nbsp; Type&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Disp Enb Address&nbsp;&nbsp;&nbsp; What</code> <code>1&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; breakpoint&nbsp;&nbsp;&nbsp;&nbsp; keep y&nbsp;&nbsp; 0x08435180 in zif_sleep at /usr/local/src/php-5.5.23/ext/standard/basic_functions.c:4449</code> <code>2&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; breakpoint&nbsp;&nbsp;&nbsp;&nbsp; keep y&nbsp;&nbsp; 0x08426923 in zif_in_array at /usr/local/src/php-5.5.23/ext/standard/array.c:1215</code> <code>3&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; breakpoint&nbsp;&nbsp;&nbsp;&nbsp; keep y&nbsp;&nbsp; 0x08438273 in zif_print_r at /usr/local/src/php-5.5.23/ext/standard/basic_functions.c:5553</code> <code>4&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; breakpoint&nbsp;&nbsp;&nbsp;&nbsp; keep y&nbsp;&nbsp; 0x0847d296 in zif_var_dump at /usr/local/src/php-5.5.23/ext/standard/var.c:178</code> <code>5&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; breakpoint&nbsp;&nbsp;&nbsp;&nbsp; keep y&nbsp;&nbsp; 0x0806a390 &lt;</code><code>printf</code><code>@plt&gt;</code> <code>6&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; breakpoint&nbsp;&nbsp;&nbsp;&nbsp; keep y&nbsp;&nbsp; 0x08069390 &lt;</code><code>memcpy</code><code>@plt&gt;</code> <code>(gdb)</code> </td> 
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加几个断点测试一下 syntax：break \[file\_name\]:func\_name，这里大致可以看一下 echo print等不是函数了

然后开始调试

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 <td> <code>(gdb) run kk.php ( or set args ./kk.php &amp;&amp; r)</code> <code>Starting program: /usr/bin/php kk.php</code> <code>[Thread debugging&nbsp;</code><code>using</code>&nbsp;<code>libthread_db enabled]</code> <code>0</code> &nbsp; <code>Breakpoint 3, zif_sleep (ht=1, return_value=0xb7fbd6f0, return_value_ptr=0x0, this_ptr=0x0, return_value_used=0)</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>at /usr/local/src/php-5.5.23/ext/standard/basic_functions.c:4449</code> <code>4449&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>if</code>&nbsp;<code>(zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC,&nbsp;</code><code>"l"</code><code>, &amp;num) == FAILURE) { </code> <code>(gdb)</code> </td> 
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这里我们可以看一下zif\_sleep 函数 return\_value 返回的是什么

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 <td> 1 2 3 4 5 6 7 8 </td> 
 <td> <code>(gdb) p *return_value</code> <code>$1 = {value = {lval = 1515870810, dval = 1.7838867517321418e+127, str = {val = 0x5a5a5a5a &lt;Address 0x5a5a5a5a out of bounds&gt;,</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>len = 1515870810}, ht = 0x5a5a5a5a, obj = {handle = 1515870810, handlers = 0x5a5a5a5a}}, refcount__gc = 1, type = 0&nbsp;</code><code>'\000'</code><code>, is_ref__gc = 0&nbsp;</code><code>'\000'</code><code>}</code> <code>(gdb) p return_value-&gt;value</code> <code>$2 = {lval = 1515870810, dval = 1.7838867517321418e+127, str = {val = 0x5a5a5a5a &lt;Address 0x5a5a5a5a out of bounds&gt;,</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>len = 1515870810}, ht = 0x5a5a5a5a, obj = {handle = 1515870810, handlers = 0x5a5a5a5a}}</code> <code>(gdb) p return_value-&gt;value-&gt;lval</code> <code>$3 = 1515870810</code> </td> 
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我们还可以使用内置的gdbinit来调试

<table> 
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 <td> 1 2 3 </td> 
 <td> <code>(gdb) source /usr/local/src/php-5.5.23/.gdbinit</code> <code>(gdb) zbacktrace</code> <code>[0xb7fa1144] sleep(3) /code/kk.php:4</code> </td> 
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</table>

查看当前堆栈，PHP内核的执行过程

查看代码段

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 <td> 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 </td> 
 <td> <code>(gdb) l</code> <code>4444&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Delay&nbsp;</code><code>for</code>&nbsp;<code>a given number of seconds */</code> <code>4445&nbsp;&nbsp;&nbsp; PHP_FUNCTION(sleep)</code> <code>4446&nbsp;&nbsp;&nbsp; { </code> <code>4447&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>long</code>&nbsp;<code>num;</code> <code>4448</code> <code>4449&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>if</code>&nbsp;<code>(zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC,&nbsp;</code><code>"l"</code><code>, &amp;num) == FAILURE) { </code> <code>4450&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; RETURN_FALSE;</code> <code>4451&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; }</code> <code>4452&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>if</code>&nbsp;<code>(num &lt; 0) { </code> <code>4453&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; php_error_docref(NULL TSRMLS_CC, E_WARNING,&nbsp;</code><code>"Number of seconds must be greater than or equal to 0"</code><code>);</code> <code>(gdb) l 4450</code> <code>4445&nbsp;&nbsp;&nbsp; PHP_FUNCTION(sleep)</code> <code>4446&nbsp;&nbsp;&nbsp; { </code> <code>4447&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>long</code>&nbsp;<code>num;</code> <code>4448</code> <code>4449&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>if</code>&nbsp;<code>(zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC,&nbsp;</code><code>"l"</code><code>, &amp;num) == FAILURE) { </code> <code>4450&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; RETURN_FALSE;</code> <code>4451&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; }</code> <code>4452&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>if</code>&nbsp;<code>(num &lt; 0) { </code> <code>4453&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; php_error_docref(NULL TSRMLS_CC, E_WARNING,&nbsp;</code><code>"Number of seconds must be greater than or equal to 0"</code><code>);</code> <code>4454&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; RETURN_FALSE;</code> <code>(gdb) l zif_usleep</code> <code>4463&nbsp;&nbsp;&nbsp;&nbsp;</code><code>/* }}} */</code> <code>4464</code> <code>4465&nbsp;&nbsp;&nbsp;&nbsp;</code><code>/* { { { proto void usleep(int micro_seconds)</code> <code>4466&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Delay for a given number of micro seconds */</code> <code>4467&nbsp;&nbsp;&nbsp; PHP_FUNCTION(usleep)</code> <code>4468&nbsp;&nbsp;&nbsp; { </code> <code>4469&nbsp;&nbsp;&nbsp; #</code><code>if</code>&nbsp;<code>HAVE_USLEEP</code> <code>4470&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>long</code>&nbsp;<code>num;</code> <code>4471</code> <code>4472&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>if</code>&nbsp;<code>(zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC,&nbsp;</code><code>"l"</code><code>, &amp;num) == FAILURE) { </code> </td> 
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继续执行

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 <td> 1 2 3 4 5 6 7 8 9 10 11 </td> 
 <td> <code>(gdb) n</code> <code>4452&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>if</code>&nbsp;<code>(num &lt; 0) { </code> <code>(gdb) p num</code> <code>$6 = 3</code> <code>(gdb) n</code> <code>4457&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; RETURN_LONG(php_sleep(num));</code> <code>(gdb) n</code> <code>4462&nbsp;&nbsp;&nbsp; }</code> <code>(gdb) n</code> <code>execute_internal (execute_data_ptr=0xb7fa1144, fci=0x0, return_value_used=0) at /usr/local/src/php-5.5.23/Zend/zend_execute.c:1488</code> <code>1488&nbsp;&nbsp;&nbsp; }</code> </td> 
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</table>

到了execute\_internal ，可以查看一下当前函数的一个状态

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 <td> 1 2 3 4 5 6 7 8 9 10 11 12 13 </td> 
 <td> <code>(gdb) p execute_data_ptr</code> <code>$7 = (zend_execute_data *) 0xb7fa1144</code> <code>(gdb) p *execute_data_ptr</code> <code>$8 = {opline = 0xb7fbcacc, function_state = {function = 0x8bcf3e8, arguments = 0xb7fa119c}, op_array = 0xb7fbc7b4, object = 0x0,</code> <code>&nbsp;&nbsp;</code><code>symbol_table = 0x8b99cdc, prev_execute_data = 0x0, old_error_reporting = 0x0, nested = 0&nbsp;</code><code>'\000'</code><code>,</code> <code>&nbsp;&nbsp;</code><code>original_return_value = 0x38b4ac9, current_scope = 0x49, current_called_scope = 0x45, current_this = 0x0, fast_ret = 0x0,</code> <code>&nbsp;&nbsp;</code><code>call_slots = 0xb7fa1188, call = 0xb7fa1188}</code> <code>(gdb) p *execute_data_ptr-&gt;function_state.function-&gt;common-&gt;function_name</code> <code>$9 = 115&nbsp;</code><code>'s'</code> <code>(gdb) p execute_data_ptr-&gt;function_state.function-&gt;common-&gt;function_name</code> <code>$10 = 0x8af03c9&nbsp;</code><code>"sleep"</code> <code>(gdb) p execute_data_ptr-&gt;op_array-&gt;filename</code> <code>$11 = 0xb7fbc8e8&nbsp;</code><code>"/code/kk.php"</code> </td> 
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 </tbody> 
</table>

查看当前hashtable

<table> 
 <tbody> 
 <tr> 
 <td> 1 2 3 4 </td> 
 <td> <code>(gdb) p *execute_data_ptr-&gt;symbol_table</code> <code>$16 = {nTableSize = 64, nTableMask = 63, nNumOfElements = 8, nNextFreeElement = 0, pInternalPointer = 0xb7fb924c,</code> <code>&nbsp;&nbsp;</code><code>pListHead = 0xb7fb924c, pListTail = 0xb7fbd228, arBuckets = 0xb7fb9120, pDestructor = 0x85bf06f &lt;_zval_ptr_dtor_wrapper&gt;,</code> <code>&nbsp;&nbsp;</code><code>persistent = 0&nbsp;</code><code>'\000'</code><code>, nApplyCount = 0&nbsp;</code><code>'\000'</code><code>, bApplyProtection = 1&nbsp;</code><code>'\001'</code><code>, inconsistent = 0}</code> </td> 
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 </tbody> 
</table>

继续执行输出c之后，回车即可，同样可以看到in\_array的执行信息

<table> 
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 <tr> 
 <td> 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 </td> 
 <td> <code>(gdb) p *execute_data_ptr-&gt;function_state.function</code> <code>$24 = {type = 1&nbsp;</code><code>'\001'</code><code>, common = {type = 1&nbsp;</code><code>'\001'</code><code>, function_name = 0x8af1841&nbsp;</code><code>"in_array"</code><code>, scope = 0x0, fn_flags = 256,</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>prototype = 0x0, num_args = 3, required_num_args = 2, arg_info = 0x8ae7554}, op_array = {type = 1&nbsp;</code><code>'\001'</code><code>,</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>function_name = 0x8af1841&nbsp;</code><code>"in_array"</code><code>, scope = 0x0, fn_flags = 256, prototype = 0x0, num_args = 3, required_num_args = 2,</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>arg_info = 0x8ae7554, refcount = 0x842691d, opcodes = 0x8bcf120, last = 0, vars = 0x0, last_var = 0, T = 1,</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>nested_calls = 3086618796, used_stack = 0, brk_cont_array = 0x0, last_brk_cont = 1, try_catch_array = 0xb7fa10dd,</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>last_try_catch = 96, has_finally_block = 160&nbsp;</code><code>'\240'</code><code>, static_variables = 0x0, this_var = 11482064,</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>filename = 0xaf1ff4&nbsp;</code><code>"|\035\257"</code><code>, line_start = 11482016, line_end = 146381272,</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>doc_comment = 0xbffff238&nbsp;</code><code>"x\362\377\277\244\aY\b\021"</code><code>, doc_comment_len = 10305959, early_binding = 11085989,</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>literals = 0x8b7a0a0, last_literal = 140062666, run_time_cache = 0xb7fa10d4, last_cache_slot = 90, reserved = {0x9, 0x8b5f7ac,</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>0x796, 0x0}}, internal_function = {type = 1&nbsp;</code><code>'\001'</code><code>, function_name = 0x8af1841&nbsp;</code><code>"in_array"</code><code>, scope = 0x0, fn_flags = 256,</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>prototype = 0x0, num_args = 3, required_num_args = 2, arg_info = 0x8ae7554, handler = 0x842691d &lt;zif_in_array&gt;,</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>module = 0x8bcf120}}</code> <code>(gdb) p execute_data_ptr-&gt;function_state.function-&gt;common-&gt;function_name</code> <code>$26 = 0x8af1841&nbsp;</code><code>"in_array"</code> <code>(gdb) p execute_data_ptr-&gt;op_array-&gt;filename&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code> <code>$27 = 0xb7fbc8e8&nbsp;</code><code>"/code/kk.php"</code> </td> 
 </tr> 
 </tbody> 
</table>

还可以加一下监控watch、设置一些调试变量set 等等

其他的调试工具还有 strace 查看系统调用、ltrace 查看类库的调用、vld查看opcode

参考文章

http://www.cprogramming.com/gcc.html

http://www.thegeekstuff.com/2010/03/debug-c-program-using-gdb/

http://www.cprogramming.com/gdb.html

http://www.laruence.com/2011/06/23/2057.html

http://derickrethans.nl/what-is-php-doing.html

来源：[https://www.cnblogs.com/chenpingzhao/p/5027984.html][https_www.cnblogs.com_chenpingzhao_p_5027984.html]

[https_www.cnblogs.com_chenpingzhao_p_5027984.html]: https://www.cnblogs.com/chenpingzhao/p/5027984.html