PHP kernel analysis (6)-opcode

01    // 一个opcode的结构    
02    struct _zend_op {    
03         const void *handler; // opcode对应的执行函数，每个opcode都有一个对应的执行函数    
04         znode_op op1;  // 执行参数的第一个元素    
05         znode_op op2;  //  执行参数的第二个元素    
06         znode_op result; // 执行结果    
07         uint32_t extended_value; // 额外扩展的字段和值    
08         uint32_t lineno; // 行数    
09         zend_uchar opcode;   // 操作码，具体操作码列表见 http://cn.php.net/manual/zh/internals2.opcodes.php    
10         zend_uchar op1_type; // 第一个元素的类型    
11         zend_uchar op2_type; // 第二个元素的类型    
12         zend_uchar result_type; // 结果的类型    
13    };

01    $ bin/phpdbg -f /home/xiaoju/software/php7/demo/echo.php    
02    prompt> list 100    
03    00001:  print exec    
11    [Context /home/xiaoju/software/php7/demo/echo.php (6 ops)]    
12    L1-7 {main}() /home/xiaoju/software/php7/demo/echo.php - 0x7fe3fae63300 + 6 ops    
13    L3    #0     ASSIGN                  $a                   1    
14    L4    #1     ASSIGN                  $b                   $a    
15    L5    #2     ADD                     $b                   1                    ~2    
16    L5    #3     ASSIGN                  $b                   ~2    
17    L6    #4     ECHO                    $b    
18    L7    #5     RETURN                  1

1    _zendop.lineno  op号   _zend_op.opcode       _zend_op.op1          _zend_op.op2          _zend_op.result    
2    L5              #2     ADD                     $b                   1                    ~2

 1 
Copy after login

/home/xiaoju/software/php7/bin/php

/home/xiaoju/webroot/php-src/php-src-master/

$ gdb /home/xiaoju/software/php7/bin/php

(gdb) source /home/xiaoju/webroot/php-src/php-src-master/.gdbinit

(gdb) b zend_execute_scripts

(gdb) run -f /home/xiaoju/software/php7/demo/echo.php

01    1452          for (i = 0; i < file_count; i++) {    
02    1453               file_handle = va_arg(files, zend_file_handle *);    
03    1454               if (!file_handle) {    
04    1455                    continue;    
05    1456               }    
06    1457    
07    1458               op_array = zend_compile_file(file_handle, type);    
08    1459               if (file_handle->opened_path) {    
09    1460                    zend_hash_add_empty_element(&EG(included_files), file_handle->opened_path);    
10    1461               }    
11    
12    (gdb) b 1459

1    (gdb) continue    
2    (gdb) s    
3    (gdb) s

1    (gdb) p *op_array    
2    $4 = {type = 2 '\002', arg_flags = "\000\000", fn_flags = 134217728, function_name = 0x0, scope = 0x0,    
3      prototype = 0x0, num_args = 0, required_num_args = 0, arg_info = 0x0, refcount = 0x7ffff6002000, last = 6,    
4      opcodes = 0x7ffff6076240, last_var = 2, T = 4, vars = 0x7ffff6079030, last_live_range = 0, last_try_catch = 0,    
5      live_range = 0x0, try_catch_array = 0x0, static_variables = 0x0, filename = 0x7ffff605c2d0, line_start = 1,    
6      line_end = 7, doc_comment = 0x0, early_binding = 4294967295, last_literal = 3, literals = 0x7ffff60030c0,    
7      cache_size = 0, run_time_cache = 0x0, reserved = {0x0, 0x0, 0x0, 0x0}}

01    (gdb) set print pretty on    
02    (gdb) p *op_array    
03    $5 = {    
04      type = 2 '\002',    
05      arg_flags = "\000\000",    
06      fn_flags = 134217728,    
07      function_name = 0x0,    
08      scope = 0x0,    
09      prototype = 0x0,    
10      num_args = 0,    
11      required_num_args = 0,    
12      arg_info = 0x0,    
13      refcount = 0x7ffff6002000,    
14      last = 6,    
15      opcodes = 0x7ffff6076240,    
16      last_var = 2,    
17      T = 4,    
18      vars = 0x7ffff6079030,    
19      last_live_range = 0,    
20      last_try_catch = 0,    
21      live_range = 0x0,    
22      try_catch_array = 0x0,    
23      static_variables = 0x0,    
24      filename = 0x7ffff605c2d0,    
25      line_start = 1,    
26      line_end = 7,    
27      doc_comment = 0x0,    
28      early_binding = 4294967295,    
29      last_literal = 3,    
30      literals = 0x7ffff60030c0,    
31      cache_size = 0,    
32      run_time_cache = 0x0,    
33      reserved = {0x0, 0x0, 0x0, 0x0}    
34    }

1    (gdb) p (op_array.filename.len)    
2    $12 = 40    
3    (gdb) p *(op_array.filename.val)@40    
4    $13 = "/home/xiaoju/software/php7/demo/echo.php"

01    // opcode组成的数组，编译的时候就是生成这个结构    
02    struct _zend_op_array {    
03         zend_uchar type;  // op array的类型，比如 ZEND_EVAL_CODE    
04         zend_uchar arg_flags[3]; /* bitset of arg_info.pass_by_reference */    
05         uint32_t fn_flags;    
06         zend_string *function_name;    
07         zend_class_entry *scope;    
08         zend_function *prototype;    
09         uint32_t num_args;  // 脚本的参数    
10         uint32_t required_num_args;    
11         zend_arg_info *arg_info;    
12         /* END of common elements */    
13    
14         uint32_t *refcount; // 这个结构的引用次数    
15    
16         uint32_t last;  // opcode的个数    
17         zend_op *opcodes;  // 存储所有的opcode    
18    
19         int last_var; // php变量的个数    
20         uint32_t T;    
21         zend_string **vars; // 被编译的php变量的个数    
22    
23         int last_live_range;    
24         int last_try_catch;  // try_catch的个数    
25         zend_live_range *live_range;    
26         zend_try_catch_element *try_catch_array; //    
27    
28         /* static variables support */    
29         HashTable *static_variables; // 静态变量    
30    
31         zend_string *filename;  // 执行的脚本的文件    
32         uint32_t line_start; // 开始于第几行    
33         uint32_t line_end; // 结束于第几行    
34         zend_string *doc_comment; // 文档的注释    
35         uint32_t early_binding; /* the linked list of delayed declarations */    
36    
37         int last_literal;    
38         zval *literals;    
39    
40         int  cache_size;    
41         void **run_time_cache;    
42    
43         void *reserved[ZEND_MAX_RESERVED_RESOURCES]; // 保留字段    
44    };