1、初始化 opcode处理器列表
// main实现在文件“php-5.6.26\sapi\cgi\cgi_main.c”
int main(int argc, char *argv[])
{
if (cgi_sapi_module.startup(&cgi_sapi_module){
// php_cgi_startup实现在文件“php-5.6.26\sapi\cgi\cgi_main.c”
static int php_cgi_startup(sapi_module_struct *sapi_module)
{
if (php_module_startup(sapi_module, &cgi_module_entry, 1){
// zend_startup实现在文件“php-5.6.26\sapi\cgi\cgi_main.c”
int php_module_startup(sapi_module_struct *sf, zend_module_entry *additional_modules, uint num_additional_modules)
{
// zend_startup实现在文件“php-5.6.26\Zend\zend.c”
zend_startup(&zuf, NULL TSRMLS_CC); // !!!!
{
int zend_startup(zend_utility_functions *utility_functions, char **extensions TSRMLS_DC)
{
...
// zend_init_opcodes_handlers实现在文件php-7.2.3\Zend\zend_vm_execute.h
zend_init_opcodes_handlers(); // !!! 初始化“opcodes处理器”列表 ------------ 初始化
{
static const opcode_handler_t labels[] = {
ZEND_NOP_SPEC_HANDLER,
ZEND_NOP_SPEC_HANDLER,
ZEND_NOP_SPEC_HANDLER,
ZEND_NOP_SPEC_HANDLER,
ZEND_NOP_SPEC_HANDLER,
...
ZEND_ASSIGN_POW_SPEC_CV_TMP_HANDLER,
ZEND_ASSIGN_POW_SPEC_CV_VAR_HANDLER,
ZEND_ASSIGN_POW_SPEC_CV_UNUSED_HANDLER,
ZEND_ASSIGN_POW_SPEC_CV_CV_HANDLER,
ZEND_NULL_HANDLER
};
zend_opcode_handlers = (opcode_handler_t*)labels;
}
...
}
}
}
} == FAILURE) {
return FAILURE;
}
return SUCCESS;
}
} == FAILURE) { // startup ---> php_cgi_startup ---> php_module_startup
#ifdef ZTS ---
tsrm_shutdown();
#endif
return FAILURE;
}
}
2、注入opcode处理器 & 执行opcode处理器
// 在文件 php-5.6.26\main\main.c
PHPAPI int php_execute_script(zend_file_handle *primary_file TSRMLS_DC)
{
...
/*
If cli primary file has shabang line and there is a prepend file,
the `start_lineno` will be used by prepend file but not primary file,
save it and restore after prepend file been executed.
*/
if (CG(start_lineno) && prepend_file_p) {
int orig_start_lineno = CG(start_lineno);
CG(start_lineno) = 0;
if (zend_execute_scripts(ZEND_REQUIRE TSRMLS_CC, NULL, 1, prepend_file_p) == SUCCESS) {
CG(start_lineno) = orig_start_lineno;
retval = (zend_execute_scripts(ZEND_REQUIRE TSRMLS_CC, NULL, 2, primary_file, append_file_p) == SUCCESS);
}
} else {
// 在文件 php-5.6.26\Zend\zend.c
retval = (zend_execute_scripts(ZEND_REQUIRE TSRMLS_CC, NULL, 3, prepend_file_p, primary_file, append_file_p) == SUCCESS); // 执行primary_file的php脚本
{
...
EG(active_op_array) = zend_compile_file(file_handle, type TSRMLS_CC); // 编译PHP文件成操作码 op_code ，zend_compile_file == compile_file
{
// 在文件 php-5.6.26\Zend\zend_language_scanner.c !!!编译文件，编译出opcode
ZEND_API zend_op_array *compile_file(zend_file_handle *file_handle, int type TSRMLS_DC)
{
...
if (retval) {
CG(active_op_array) = original_active_op_array; // 还原原来 op_code 现场（还原现场）
if (compilation_successful) { // !!!汇编成功
// 在文件 php-5.6.26\Zend\zend_opcode.c
pass_two(op_array TSRMLS_CC); // !!!! 给每个op_code注册“op_code处理器”
{
...
while (opline < end) { // 迭代所有操作码
if (opline->op1_type == IS_CONST) { // 如果是是常量
opline->op1.zv = &op_array->literals[opline->op1.constant].constant;
}
if (opline->op2_type == IS_CONST) {
opline->op2.zv = &op_array->literals[opline->op2.constant].constant;
}
switch (opline->opcode) {
case ZEND_GOTO:
if (Z_TYPE_P(opline->op2.zv) != IS_LONG) {
zend_resolve_goto_label(op_array, opline, 1 TSRMLS_CC);
}
/* break omitted intentionally */
case ZEND_JMP:
case ZEND_FAST_CALL:
opline->op1.jmp_addr = &op_array->opcodes[opline->op1.opline_num];
break;
case ZEND_JMPZ:
case ZEND_JMPNZ:
case ZEND_JMPZ_EX:
case ZEND_JMPNZ_EX:
case ZEND_JMP_SET:
case ZEND_JMP_SET_VAR:
opline->op2.jmp_addr = &op_array->opcodes[opline->op2.opline_num];
break;
case ZEND_RETURN:
case ZEND_RETURN_BY_REF:
if (op_array->fn_flags & ZEND_ACC_GENERATOR) {
if (opline->op1_type != IS_CONST || Z_TYPE_P(opline->op1.zv) != IS_NULL) {
CG(zend_lineno) = opline->lineno;
zend_error_noreturn(E_COMPILE_ERROR, "Generators cannot return values using \"return\"");
}
opline->opcode = ZEND_GENERATOR_RETURN;
}
break;
}
ZEND_VM_SET_OPCODE_HANDLER(opline); // 设置“opcode处理器” ------------ 注入
{
// 宏定义在文件 “php-5.6.26\Zend\zend_vm.h ”
#define ZEND_VM_SET_OPCODE_HANDLER(opline) zend_vm_set_opcode_handler(opline)
{
// zend_vm_set_opcode_handler 实现在文件“php-5.6.26\Zend\zend_vm_execute.h”，
ZEND_API void zend_vm_set_opcode_handler(zend_op* op) // 获取“opcode处理器”
{
op->handler = zend_vm_get_opcode_handler(zend_user_opcodes[op->opcode], op);
{
// zend_vm_get_opcode_handler实现在文件“php-5.6.26\Zend\zend_vm_execute.h”，
static opcode_handler_t zend_vm_get_opcode_handler(zend_uchar opcode, zend_op* op) // 获取“opcode处理器”
{
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_type] * 5 + zend_vm_decode[op->op2_type]];
}
}
}
}
}
opline++;
}
op_array->fn_flags |= ZEND_ACC_DONE_PASS_TWO;
return 0;
...
}
zend_release_labels(0 TSRMLS_CC);
} else {
efree(op_array);
retval = NULL;
}
}
...
}
// !!! 执行 opcode 列表
if (EG(active_op_array)) { // “操作码”数组
EG(return_value_ptr_ptr) = retval ? retval : NULL;
// 在文件 php-5.6.26\Zend\zend_vm_execute.c
zend_execute(EG(active_op_array) TSRMLS_CC); // 执行编译后的操作码 op_code ， zend_execute == execute_ex
{
if (EG(exception)) {
return;
}
// 在文件 php-5.6.26\Zend\zend_vm_execute.c
zend_execute_ex(i_create_execute_data_from_op_array(op_array, 0 TSRMLS_CC) TSRMLS_CC); // zend_execute_ex = execute_ex
{
DCL_OPLINE
zend_bool original_in_execution;
original_in_execution = EG(in_execution); // 保存现场
EG(in_execution) = 1; // 正在执行中
if (0) {
zend_vm_enter:
execute_data = i_create_execute_data_from_op_array(EG(active_op_array), 1 TSRMLS_CC);
}
LOAD_REGS();
LOAD_OPLINE();
while (1) {
int ret;
#ifdef ZEND_WIN32
if (EG(timed_out)) {
zend_timeout(0);
}
#endif
/*
OPLINE->handler(execute_data TSRMLS_CC)
EX(opline)->handler(execute_data TSRMLS_CC)
execute_data.opline->handler(execute_data TSRMLS_CC)
*/
if ((ret = OPLINE->handler(execute_data TSRMLS_CC)) > 0) { // execute_data.opline->handler(execute_data TSRMLS_CC) // 调用“opcode对应的处理函数” ------------调用
switch (ret) {
case 1:
EG(in_execution) = original_in_execution; // 还原现场
return;
case 2:
goto zend_vm_enter; // 进入虚拟机
break;
case 3:
execute_data = EG(current_execute_data); // 当前正在执行的数据
break;
default:
break;
}
}
}
zend_error_noreturn(E_ERROR, "Arrived at end of main loop which shouldn't happen");
}
}
...
}
...
}
...
}
}
...
}
