19.opcode处理函数查找

ZEND_API void execute(zend_op_array *op_array TSRMLS_DC)
{
...
zend_vm_enter:
....
if ((ret = EX(opline)->handler(execute_data TSRMLS_CC)) > 0) {
switch (ret) {
                case 1:
                    EG(in_execution) = original_in_execution;
return;
                case 2:
                    op_array = EG(active_op_array);
                    goto zend_vm_enter;
                case 3:
                    execute_data = EG(current_execute_data);
                default:
break;
            }
｝
...
}

static opcode_handler_t
zend_vm_get_opcode_handler(zend_uchar opcode, zend_op* op)
{
static const int zend_vm_decode[] = {
            _UNUSED_CODE, /* 0 */
            _CONST_CODE,  /* 1 = IS_CONST */
            _TMP_CODE,    /* 2 = IS_TMP_VAR */
            _UNUSED_CODE, /* 3 */
            _VAR_CODE,    /* 4 = IS_VAR */
            _UNUSED_CODE, /* 5 */
            _UNUSED_CODE, /* 6 */
            _UNUSED_CODE, /* 7 */
            _UNUSED_CODE, /* 8 = IS_UNUSED */
            _UNUSED_CODE, /* 9 */
            _UNUSED_CODE, /* 10 */
            _UNUSED_CODE, /* 11 */
            _UNUSED_CODE, /* 12 */
            _UNUSED_CODE, /* 13 */
            _UNUSED_CODE, /* 14 */
            _UNUSED_CODE, /* 15 */
            _CV_CODE      /* 16 = IS_CV */
        };  
return zend_opcode_handlers[
             opcode * 25 + zend_vm_decode[op->op1.op_type] * 5
                     + zend_vm_decode[op->op2.op_type]];
}

//函数调用：
DO_FCALL  ==>  ZEND_DO_FCALL_SPEC_CONST_HANDLER

//变量赋值：
ASSIGN     =>      ZEND_ASSIGN_SPEC_VAR_CONST_HANDLER
                   ZEND_ASSIGN_SPEC_VAR_TMP_HANDLER
                   ZEND_ASSIGN_SPEC_VAR_VAR_HANDLER
                   ZEND_ASSIGN_SPEC_VAR_CV_HANDLER            
//变量加法：
ASSIGN_SUB =>   ZEND_ASSIGN_SUB_SPEC_VAR_CONST_HANDLER,
                    ZEND_ASSIGN_SUB_SPEC_VAR_TMP_HANDLER,
                    ZEND_ASSIGN_SUB_SPEC_VAR_VAR_HANDLER,
                    ZEND_ASSIGN_SUB_SPEC_VAR_UNUSED_HANDLER,
                    ZEND_ASSIGN_SUB_SPEC_VAR_CV_HANDLER,
                    ZEND_ASSIGN_SUB_SPEC_UNUSED_CONST_HANDLER,
                    ZEND_ASSIGN_SUB_SPEC_UNUSED_TMP_HANDLER,
                    ZEND_ASSIGN_SUB_SPEC_UNUSED_VAR_HANDLER,
                    ZEND_ASSIGN_SUB_SPEC_UNUSED_UNUSED_HANDLER,
                    ZEND_ASSIGN_SUB_SPEC_UNUSED_CV_HANDLER,
                    ZEND_ASSIGN_SUB_SPEC_CV_CONST_HANDLER,
                    ZEND_ASSIGN_SUB_SPEC_CV_TMP_HANDLER,
                    ZEND_ASSIGN_SUB_SPEC_CV_VAR_HANDLER,
                    ZEND_ASSIGN_SUB_SPEC_CV_UNUSED_HANDLER,
                    ZEND_ASSIGN_SUB_SPEC_CV_CV_HANDLER,

static opcode_handler_t
zend_vm_get_opcode_handler(zend_uchar opcode, zend_op* op)
{
static const int zend_vm_decode[] = {
            _UNUSED_CODE, /* 0 */
            _CONST_CODE,  /* 1 = IS_CONST */
            _TMP_CODE,    /* 2 = IS_TMP_VAR */
            _UNUSED_CODE, /* 3 */
            _VAR_CODE,    /* 4 = IS_VAR */
            _UNUSED_CODE, /* 5 */
            _UNUSED_CODE, /* 6 */
            _UNUSED_CODE, /* 7 */
            _UNUSED_CODE, /* 8 = IS_UNUSED */
            _UNUSED_CODE, /* 9 */
            _UNUSED_CODE, /* 10 */
            _UNUSED_CODE, /* 11 */
            _UNUSED_CODE, /* 12 */
            _UNUSED_CODE, /* 13 */
            _UNUSED_CODE, /* 14 */
            _UNUSED_CODE, /* 15 */
            _CV_CODE      /* 16 = IS_CV */
        };  

//很显然，我们把opcode和相对应的写到了/tmp/php.log文件中
int op_index;
     op_index = opcode * 25 + zend_vm_decode[op->op1.op_type] * 5 + zend_vm_decode[op->op2.op_type];

     FILE *stream;
if((stream = fopen("/tmp/php.log", "a+")) != NULL){
         fprintf(stream, "opcode: %d , zend_opcode_handlers_index:%d\n", opcode, op_index);
     }    
     fclose(stream);


return zend_opcode_handlers[
             opcode * 25 + zend_vm_decode[op->op1.op_type] * 5
                     + zend_vm_decode[op->op2.op_type]];
}

---

http://www.php-internals.com/book/?p=chapt02/02-03-03-from-opcode-to-handler