php 部分语法的AST、栈、符号表、和指令集

break 语法的AST、栈、符号表和指令集

先写一个测试脚本 break.php

<?php
while(1){
    break;
}

gdb调试过程：

抽象语法树：

栈、符号表和常量

指令集

实战文件的引入实现

include语法
require语法
include_once语法
require_once语法

先编写两个文件 1.php

1 2	<?php echo 1;

2.php

1
2
3

<?php
include "1.php";
echo 2;

include gdb

(gdb) b zend_compile
Breakpoint 1 at 0x7f85f8: file Zend/zend_language_scanner.l, line 578.
(gdb) r 2.php
Starting program: /usr/local/bin/php71 2.php
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".

Breakpoint 1, zend_compile (type=2) at Zend/zend_language_scanner.l:578
578		zend_op_array *op_array = NULL;
(gdb)
(gdb) n
579		zend_bool original_in_compilation = CG(in_compilation);
(gdb)
581		CG(in_compilation) = 1;
(gdb)
582		CG(ast) = NULL;
(gdb)
583		CG(ast_arena) = zend_arena_create(1024 * 32);
(gdb)
585		if (!zendparse()) {
(gdb)
586			int last_lineno = CG(zend_lineno);
(gdb)
589			zend_op_array *original_active_op_array = CG(active_op_array);
(gdb) p compiler_globals.ast
$1 = (zend_ast *) 0x7ffff5e7a018
(gdb) p *compiler_globals.ast
$2 = {kind = 132, attr = 0, lineno = 1, child = {0x2}}
(gdb) p *(zend_ast_list)compiler_globals.ast
Structure has no component named operator*.
(gdb) p *(zend_ast_list*)compiler_globals.ast
$3 = {kind = 132, attr = 0, lineno = 1, children = 2, child = {0x7ffff5e7a060}}
(gdb) p $3.child[0]
$4 = (zend_ast *) 0x7ffff5e7a060
(gdb) p *$3.child[0]
$5 = {kind = 269, attr = 2, lineno = 2, child = {0x7ffff5e7a048}}
(gdb) p $5.child[0]
$6 = (zend_ast *) 0x7ffff5e7a048
(gdb) p *$5.child[0]
$7 = {kind = 64, attr = 0, lineno = 0, child = {0x7ffff5e5eac0}}
(gdb) p *(zend_ast_zval*)$5.child[0]
$8 = {kind = 64, attr = 0, val = {value = {lval = 140737318873792, dval = 6.9533474343345501e-310, counted = 0x7ffff5e5eac0,
      str = 0x7ffff5e5eac0, arr = 0x7ffff5e5eac0, obj = 0x7ffff5e5eac0, res = 0x7ffff5e5eac0, ref = 0x7ffff5e5eac0,
      ast = 0x7ffff5e5eac0, zv = 0x7ffff5e5eac0, ptr = 0x7ffff5e5eac0, ce = 0x7ffff5e5eac0, func = 0x7ffff5e5eac0, ww = {
        w1 = 4125485760, w2 = 32767}}, u1 = {v = {type = 6 '\006', type_flags = 20 '\024', const_flags = 0 '\000', reserved = 0 '\000'},
      type_info = 5126}, u2 = {next = 2, cache_slot = 2, lineno = 2, num_args = 2, fe_pos = 2, fe_iter_idx = 2, access_flags = 2,
      property_guard = 2}}}
(gdb) p $8.val.value.str
$9 = (zend_string *) 0x7ffff5e5eac0
(gdb) p *$8.val.value.str
$10 = {gc = {refcount = 1, u = {v = {type = 6 '\006', flags = 0 '\000', gc_info = 0}, type_info = 6}}, h = 0, len = 5, val = "1"}
(gdb) p *$8.val.value.str.val@5
$11 = "1.php"
(gdb) p $3.child[1]
$12 = (zend_ast *) 0x7ffff5e7a098
(gdb) p *$3.child[1]
$13 = {kind = 132, attr = 0, lineno = 3, child = {0x1}}
(gdb) p *(zend_ast_list*)$3.child[1]
$14 = {kind = 132, attr = 0, lineno = 3, children = 1, child = {0x7ffff5e7a088}}
(gdb) p $14.child[0]
$15 = (zend_ast *) 0x7ffff5e7a088
(gdb) p *$14.child[0]
$16 = {kind = 282, attr = 0, lineno = 3, child = {0x7ffff5e7a070}}
(gdb) p *$16.child[0]
$17 = {kind = 64, attr = 0, lineno = 0, child = {0x2}}
(gdb) p *(zend_ast_zval*)$16.child[0]
$18 = {kind = 64, attr = 0, val = {value = {lval = 2, dval = 9.8813129168249309e-324, counted = 0x2, str = 0x2, arr = 0x2, obj = 0x2,
      res = 0x2, ref = 0x2, ast = 0x2, zv = 0x2, ptr = 0x2, ce = 0x2, func = 0x2, ww = {w1 = 2, w2 = 0}}, u1 = {v = {type = 4 '\004',
        type_flags = 0 '\000', const_flags = 0 '\000', reserved = 0 '\000'}, type_info = 4}, u2 = {next = 3, cache_slot = 3, lineno = 3,
      num_args = 3, fe_pos = 3, fe_iter_idx = 3, access_flags = 3, property_guard = 3}}}
(gdb)

include AST

栈符号表和常量

指令集

条件判断语法实现

先编写文件 `condition.php`

<?php
$a = "php7";
if($a == "php5"){
    echo "PHP5 is good.\n";
}elseif($a == 'php7'){
    echo "PHP7 is better.\n";
}else{
    echo "Hoho~ PHP is the best language!\n";
}

AST 语法树

栈符号表常量

指令集

实战：循环语法实现

foreach 语法
while 语法
for 语法
do while 语法

先编写文件 `foreach.php`

<?php
$a = [1, 2];
foreach($a as $k => $v){
    echo $v;
}

AST 语法树

栈符号表和常量

指令集

执行过程gdb

[root@yyl PHP]# gdb php71
GNU gdb (GDB) Red Hat Enterprise Linux 7.6.1-114.el7
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-redhat-linux-gnu".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>...
Reading symbols from /usr/local/php/php-7.1.0/bin/php...done.
(gdb) b zend_compile
Breakpoint 1 at 0x7f85f8: file Zend/zend_language_scanner.l, line 578.
(gdb) b zend_execute
Breakpoint 2 at 0x8aea82: file /root/php-7.1.0/Zend/zend_vm_execute.h, line 461.
(gdb) b execute_ex
Breakpoint 3 at 0x8aea15: file /root/php-7.1.0/Zend/zend_vm_execute.h, line 411.
(gdb) r foreach.php
Starting program: /usr/local/bin/php71 foreach.php
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".

Breakpoint 1, zend_compile (type=2) at Zend/zend_language_scanner.l:578
578		zend_op_array *op_array = NULL;
(gdb) c
Continuing.

Breakpoint 2, zend_execute (op_array=0x7ffff5e83000, return_value=0x0) at /root/php-7.1.0/Zend/zend_vm_execute.h:461
461		if (EG(exception) != NULL) {
(gdb) n
466			(zend_function*)op_array, 0, zend_get_called_scope(EG(current_execute_data)), zend_get_this_object(EG(current_execute_data)));
(gdb)
465		execute_data = zend_vm_stack_push_call_frame(ZEND_CALL_TOP_CODE | ZEND_CALL_HAS_SYMBOL_TABLE,
(gdb)
466			(zend_function*)op_array, 0, zend_get_called_scope(EG(current_execute_data)), zend_get_this_object(EG(current_execute_data)));
(gdb)
465		execute_data = zend_vm_stack_push_call_frame(ZEND_CALL_TOP_CODE | ZEND_CALL_HAS_SYMBOL_TABLE,
(gdb)
467		if (EG(current_execute_data)) {
(gdb)
470			execute_data->symbol_table = &EG(symbol_table);
(gdb)
472		EX(prev_execute_data) = EG(current_execute_data);
(gdb)
473		i_init_execute_data(execute_data, op_array, return_value);
(gdb)
474		zend_execute_ex(execute_data);
(gdb) s

Breakpoint 3, execute_ex (ex=0x7ffff5e14030) at /root/php-7.1.0/Zend/zend_vm_execute.h:411
411		const zend_op *orig_opline = opline;
(gdb) n
414		zend_execute_data *orig_execute_data = execute_data;
(gdb)
415		execute_data = ex;
(gdb)
421		LOAD_OPLINE();
(gdb)
422		ZEND_VM_LOOP_INTERRUPT_CHECK();
(gdb)
429			((opcode_handler_t)OPLINE->handler)(ZEND_OPCODE_HANDLER_ARGS_PASSTHRU);
(gdb) s
ZEND_ASSIGN_SPEC_CV_CONST_RETVAL_UNUSED_HANDLER () at /root/php-7.1.0/Zend/zend_vm_execute.h:39440
39440		SAVE_OPLINE();
(gdb) n
39441		value = EX_CONSTANT(opline->op2);
(gdb) p opline->op2
$1 = {constant = 0, var = 0, num = 0, opline_num = 0, jmp_offset = 0}
(gdb) n
39442		variable_ptr = _get_zval_ptr_cv_undef_BP_VAR_W(execute_data, opline->op1.var);
(gdb) p value
$2 = (zval *) 0x7ffff5e649c0
(gdb) p *value
$3 = {value = {lval = 140737318847520, dval = 6.9533474330365409e-310, counted = 0x7ffff5e58420, str = 0x7ffff5e58420,
    arr = 0x7ffff5e58420, obj = 0x7ffff5e58420, res = 0x7ffff5e58420, ref = 0x7ffff5e58420, ast = 0x7ffff5e58420, zv = 0x7ffff5e58420,
    ptr = 0x7ffff5e58420, ce = 0x7ffff5e58420, func = 0x7ffff5e58420, ww = {w1 = 4125459488, w2 = 32767}}, u1 = {v = {type = 7 '\a',
      type_flags = 28 '\034', const_flags = 0 '\000', reserved = 0 '\000'}, type_info = 7175}, u2 = {next = 4294967295,
    cache_slot = 4294967295, lineno = 4294967295, num_args = 4294967295, fe_pos = 4294967295, fe_iter_idx = 4294967295,
    access_flags = 4294967295, property_guard = 4294967295}}
(gdb) p $3.value.arr
$4 = (zend_array *) 0x7ffff5e58420
(gdb) p *$3.value.arr
$5 = {gc = {refcount = 1, u = {v = {type = 7 '\a', flags = 0 '\000', gc_info = 0}, type_info = 7}}, u = {v = {flags = 30 '\036',
      nApplyCount = 0 '\000', nIteratorsCount = 0 '\000', consistency = 0 '\000'}, flags = 30}, nTableMask = 4294967294,
  arData = 0x7ffff5e5fa08, nNumUsed = 2, nNumOfElements = 2, nTableSize = 8, nInternalPointer = 0, nNextFreeElement = 2,
  pDestructor = 0x84d18f <_zval_ptr_dtor_wrapper>}
(gdb) p $5.arData[0]
$6 = {val = {value = {lval = 1, dval = 4.9406564584124654e-324, counted = 0x1, str = 0x1, arr = 0x1, obj = 0x1, res = 0x1, ref = 0x1,
      ast = 0x1, zv = 0x1, ptr = 0x1, ce = 0x1, func = 0x1, ww = {w1 = 1, w2 = 0}}, u1 = {v = {type = 4 '\004', type_flags = 0 '\000',
        const_flags = 0 '\000', reserved = 0 '\000'}, type_info = 4}, u2 = {next = 0, cache_slot = 0, lineno = 0, num_args = 0,
      fe_pos = 0, fe_iter_idx = 0, access_flags = 0, property_guard = 0}}, h = 0, key = 0x0}
(gdb) p $5.arData[1]
$7 = {val = {value = {lval = 2, dval = 9.8813129168249309e-324, counted = 0x2, str = 0x2, arr = 0x2, obj = 0x2, res = 0x2, ref = 0x2,
      ast = 0x2, zv = 0x2, ptr = 0x2, ce = 0x2, func = 0x2, ww = {w1 = 2, w2 = 0}}, u1 = {v = {type = 4 '\004', type_flags = 0 '\000',
        const_flags = 0 '\000', reserved = 0 '\000'}, type_info = 4}, u2 = {next = 0, cache_slot = 0, lineno = 0, num_args = 0,
      fe_pos = 0, fe_iter_idx = 0, access_flags = 0, property_guard = 0}}, h = 1, key = 0x0}
(gdb) n
39450			value = zend_assign_to_variable(variable_ptr, value, IS_CONST);
(gdb) p opline->op1.var
$8 = 80
(gdb) p variable_ptr
$9 = (zval *) 0x7ffff5e14080
(gdb) n
39458		ZEND_VM_NEXT_OPCODE_CHECK_EXCEPTION();
(gdb) p *variable_ptr
$10 = {value = {lval = 140737318847520, dval = 6.9533474330365409e-310, counted = 0x7ffff5e58420, str = 0x7ffff5e58420,
    arr = 0x7ffff5e58420, obj = 0x7ffff5e58420, res = 0x7ffff5e58420, ref = 0x7ffff5e58420, ast = 0x7ffff5e58420, zv = 0x7ffff5e58420,
    ptr = 0x7ffff5e58420, ce = 0x7ffff5e58420, func = 0x7ffff5e58420, ww = {w1 = 4125459488, w2 = 32767}}, u1 = {v = {type = 7 '\a',
      type_flags = 28 '\034', const_flags = 0 '\000', reserved = 0 '\000'}, type_info = 7175}, u2 = {next = 0, cache_slot = 0,
    lineno = 0, num_args = 0, fe_pos = 0, fe_iter_idx = 0, access_flags = 0, property_guard = 0}}
(gdb) n
39459	}
(gdb)
execute_ex (ex=0x7ffff5e14030) at /root/php-7.1.0/Zend/zend_vm_execute.h:430
430			if (UNEXPECTED(!OPLINE)) {
(gdb)
453		}
(gdb)
429			((opcode_handler_t)OPLINE->handler)(ZEND_OPCODE_HANDLER_ARGS_PASSTHRU);
(gdb) s
ZEND_FE_RESET_R_SPEC_CV_HANDLER () at /root/php-7.1.0/Zend/zend_vm_execute.h:35503
35503		SAVE_OPLINE();
(gdb) n
35505		array_ptr = _get_zval_ptr_cv_deref_BP_VAR_R(execute_data, opline->op1.var);
(gdb) p opline->op1.var
$11 = 80
(gdb) n
35506		if (EXPECTED(Z_TYPE_P(array_ptr) == IS_ARRAY)) {
(gdb) p array_ptr
$12 = (zval *) 0x7ffff5e14080
(gdb) n
35507			result = EX_VAR(opline->result.var);
(gdb)
35508			ZVAL_COPY_VALUE(result, array_ptr);
(gdb) p result
$13 = (zval *) 0x7ffff5e140c0
(gdb) n
35509			if (IS_CV != IS_TMP_VAR && Z_OPT_REFCOUNTED_P(result)) {
(gdb) p *result
$14 = {value = {lval = 140737318847520, dval = 6.9533474330365409e-310, counted = 0x7ffff5e58420, str = 0x7ffff5e58420,
    arr = 0x7ffff5e58420, obj = 0x7ffff5e58420, res = 0x7ffff5e58420, ref = 0x7ffff5e58420, ast = 0x7ffff5e58420, zv = 0x7ffff5e58420,
    ptr = 0x7ffff5e58420, ce = 0x7ffff5e58420, func = 0x7ffff5e58420, ww = {w1 = 4125459488, w2 = 32767}}, u1 = {v = {type = 7 '\a',
      type_flags = 28 '\034', const_flags = 0 '\000', reserved = 0 '\000'}, type_info = 7175}, u2 = {next = 0, cache_slot = 0,
    lineno = 0, num_args = 0, fe_pos = 0, fe_iter_idx = 0, access_flags = 0, property_guard = 0}}
(gdb) p $14.value.arr
$15 = (zend_array *) 0x7ffff5e58420
(gdb) p *$14.value.arr
$16 = {gc = {refcount = 2, u = {v = {type = 7 '\a', flags = 0 '\000', gc_info = 0}, type_info = 7}}, u = {v = {flags = 30 '\036',
      nApplyCount = 0 '\000', nIteratorsCount = 0 '\000', consistency = 0 '\000'}, flags = 30}, nTableMask = 4294967294,
  arData = 0x7ffff5e5fa08, nNumUsed = 2, nNumOfElements = 2, nTableSize = 8, nInternalPointer = 0, nNextFreeElement = 2,
  pDestructor = 0x84d18f <_zval_ptr_dtor_wrapper>}
(gdb) n
35510				Z_ADDREF_P(array_ptr);
(gdb)
35512			Z_FE_POS_P(result) = 0;
(gdb) p *$14.value.arr
$17 = {gc = {refcount = 3, u = {v = {type = 7 '\a', flags = 0 '\000', gc_info = 0}, type_info = 7}}, u = {v = {flags = 30 '\036',
      nApplyCount = 0 '\000', nIteratorsCount = 0 '\000', consistency = 0 '\000'}, flags = 30}, nTableMask = 4294967294,
  arData = 0x7ffff5e5fa08, nNumUsed = 2, nNumOfElements = 2, nTableSize = 8, nInternalPointer = 0, nNextFreeElement = 2,
  pDestructor = 0x84d18f <_zval_ptr_dtor_wrapper>}
(gdb) p *result
$18 = {value = {lval = 140737318847520, dval = 6.9533474330365409e-310, counted = 0x7ffff5e58420, str = 0x7ffff5e58420,
    arr = 0x7ffff5e58420, obj = 0x7ffff5e58420, res = 0x7ffff5e58420, ref = 0x7ffff5e58420, ast = 0x7ffff5e58420, zv = 0x7ffff5e58420,
    ptr = 0x7ffff5e58420, ce = 0x7ffff5e58420, func = 0x7ffff5e58420, ww = {w1 = 4125459488, w2 = 32767}}, u1 = {v = {type = 7 '\a',
      type_flags = 28 '\034', const_flags = 0 '\000', reserved = 0 '\000'}, type_info = 7175}, u2 = {next = 0, cache_slot = 0,
    lineno = 0, num_args = 0, fe_pos = 0, fe_iter_idx = 0, access_flags = 0, property_guard = 0}}
(gdb) n
35514			ZEND_VM_NEXT_OPCODE_CHECK_EXCEPTION();
(gdb)
35606	}
(gdb)
execute_ex (ex=0x7ffff5e14030) at /root/php-7.1.0/Zend/zend_vm_execute.h:430
430			if (UNEXPECTED(!OPLINE)) {
(gdb)
453		}
(gdb)
429			((opcode_handler_t)OPLINE->handler)(ZEND_OPCODE_HANDLER_ARGS_PASSTHRU);
(gdb) s
ZEND_FE_FETCH_R_SPEC_VAR_HANDLER () at /root/php-7.1.0/Zend/zend_vm_execute.h:16708
16708		array = EX_VAR(opline->op1.var);
(gdb) n
16709		SAVE_OPLINE();
(gdb) p array
$19 = (zval *) 0x7ffff5e140c0
(gdb) n
16710		if (EXPECTED(Z_TYPE_P(array) == IS_ARRAY)) {
(gdb)
16711			fe_ht = Z_ARRVAL_P(array);
(gdb)
16712			pos = Z_FE_POS_P(array);
(gdb) p fe_ht
$20 = (HashTable *) 0x7ffff5e58420
(gdb) n
16713			p = fe_ht->arData + pos;
(gdb) p pos
$21 = 0
(gdb) n
16715				if (UNEXPECTED(pos >= fe_ht->nNumUsed)) {
(gdb)
16719				value = &p->val;
(gdb)
16720				value_type = Z_TYPE_INFO_P(value);
(gdb) p value
$22 = (zval *) 0x7ffff5e5fa08
(gdb) p *value
$23 = {value = {lval = 1, dval = 4.9406564584124654e-324, counted = 0x1, str = 0x1, arr = 0x1, obj = 0x1, res = 0x1, ref = 0x1,
    ast = 0x1, zv = 0x1, ptr = 0x1, ce = 0x1, func = 0x1, ww = {w1 = 1, w2 = 0}}, u1 = {v = {type = 4 '\004', type_flags = 0 '\000',
      const_flags = 0 '\000', reserved = 0 '\000'}, type_info = 4}, u2 = {next = 0, cache_slot = 0, lineno = 0, num_args = 0,
    fe_pos = 0, fe_iter_idx = 0, access_flags = 0, property_guard = 0}}
(gdb) n
16721				if (value_type == IS_UNDEF) {
(gdb)
16725				} else if (UNEXPECTED(value_type == IS_INDIRECT)) {
(gdb) p value_type
$24 = 4
(gdb) n
16734				break;
(gdb)
16736			Z_FE_POS_P(array) = pos + 1;
(gdb)
16737			if (opline->result_type & (IS_TMP_VAR|IS_CV)) {
(gdb)
16738				if (!p->key) {
(gdb)
16739					ZVAL_LONG(EX_VAR(opline->result.var), p->h);
(gdb) p opline->result.var
$25 = 160
(gdb) p ((zval*)(((char*)(execute_data)) + ((int)(opline->result.var))))
$26 = (zval *) 0x7ffff5e140d0
(gdb) n
16856		if (EXPECTED(opline->op2_type == IS_CV)) {
(gdb) n
16857			zval *variable_ptr = _get_zval_ptr_cv_undef_BP_VAR_W(execute_data, opline->op2.var);
(gdb)
16858			zend_assign_to_variable(variable_ptr, value, IS_CV);
(gdb) p variable_ptr
$27 = (zval *) 0x7ffff5e14090
(gdb) p value
$28 = (zval *) 0x7ffff5e5fa08
(gdb) p *value
$29 = {value = {lval = 1, dval = 4.9406564584124654e-324, counted = 0x1, str = 0x1, arr = 0x1, obj = 0x1, res = 0x1, ref = 0x1,
    ast = 0x1, zv = 0x1, ptr = 0x1, ce = 0x1, func = 0x1, ww = {w1 = 1, w2 = 0}}, u1 = {v = {type = 4 '\004', type_flags = 0 '\000',
      const_flags = 0 '\000', reserved = 0 '\000'}, type_info = 4}, u2 = {next = 0, cache_slot = 0, lineno = 0, num_args = 0,
    fe_pos = 0, fe_iter_idx = 0, access_flags = 0, property_guard = 0}}
(gdb) n
16868		ZEND_VM_NEXT_OPCODE();
(gdb)
16869	}
(gdb)
execute_ex (ex=0x7ffff5e14030) at /root/php-7.1.0/Zend/zend_vm_execute.h:430
430			if (UNEXPECTED(!OPLINE)) {
(gdb)
453		}
(gdb)
429			((opcode_handler_t)OPLINE->handler)(ZEND_OPCODE_HANDLER_ARGS_PASSTHRU);
(gdb) s
ZEND_ASSIGN_SPEC_CV_TMP_RETVAL_UNUSED_HANDLER () at /root/php-7.1.0/Zend/zend_vm_execute.h:40733
40733		SAVE_OPLINE();
(gdb) n
40734		value = _get_zval_ptr_tmp(opline->op2.var, execute_data, &free_op2);
(gdb)
40735		variable_ptr = _get_zval_ptr_cv_undef_BP_VAR_W(execute_data, opline->op1.var);
(gdb) p value
$30 = (zval *) 0x7ffff5e140d0
(gdb) p *value
$31 = {value = {lval = 0, dval = 0, counted = 0x0, str = 0x0, arr = 0x0, obj = 0x0, res = 0x0, ref = 0x0, ast = 0x0, zv = 0x0,
    ptr = 0x0, ce = 0x0, func = 0x0, ww = {w1 = 0, w2 = 0}}, u1 = {v = {type = 4 '\004', type_flags = 0 '\000', const_flags = 0 '\000',
      reserved = 0 '\000'}, type_info = 4}, u2 = {next = 0, cache_slot = 0, lineno = 0, num_args = 0, fe_pos = 0, fe_iter_idx = 0,
    access_flags = 0, property_guard = 0}}
(gdb) n
40743			value = zend_assign_to_variable(variable_ptr, value, IS_TMP_VAR);
(gdb) p variable_ptr
$32 = (zval *) 0x7ffff5e140a0
(gdb) n
40751		ZEND_VM_NEXT_OPCODE_CHECK_EXCEPTION();
(gdb)
40752	}
(gdb)
execute_ex (ex=0x7ffff5e14030) at /root/php-7.1.0/Zend/zend_vm_execute.h:430
430			if (UNEXPECTED(!OPLINE)) {
(gdb)
453		}
(gdb)
429			((opcode_handler_t)OPLINE->handler)(ZEND_OPCODE_HANDLER_ARGS_PASSTHRU);
(gdb) s
ZEND_ECHO_SPEC_CV_HANDLER () at /root/php-7.1.0/Zend/zend_vm_execute.h:34640
34640		SAVE_OPLINE();
(gdb) n
34641		z = _get_zval_ptr_cv_undef(execute_data, opline->op1.var);
(gdb)
34643		if (Z_TYPE_P(z) == IS_STRING) {
(gdb) p z
$33 = (zval *) 0x7ffff5e14090
(gdb) n
34650			zend_string *str = _zval_get_string_func(z);
(gdb)
34652			if (ZSTR_LEN(str) != 0) {
(gdb) p *z
$34 = {value = {lval = 1, dval = 4.9406564584124654e-324, counted = 0x1, str = 0x1, arr = 0x1, obj = 0x1, res = 0x1, ref = 0x1,
    ast = 0x1, zv = 0x1, ptr = 0x1, ce = 0x1, func = 0x1, ww = {w1 = 1, w2 = 0}}, u1 = {v = {type = 4 '\004', type_flags = 0 '\000',
      const_flags = 0 '\000', reserved = 0 '\000'}, type_info = 4}, u2 = {next = 0, cache_slot = 0, lineno = 0, num_args = 0,
    fe_pos = 0, fe_iter_idx = 0, access_flags = 0, property_guard = 0}}
(gdb) n
34653				zend_write(ZSTR_VAL(str), ZSTR_LEN(str));
(gdb)
134657			zend_string_release(str);
(gdb) n
34660		ZEND_VM_NEXT_OPCODE_CHECK_EXCEPTION();
(gdb)
34661	}
(gdb)
execute_ex (ex=0x7ffff5e14030) at /root/php-7.1.0/Zend/zend_vm_execute.h:430
430			if (UNEXPECTED(!OPLINE)) {
(gdb)
453		}
(gdb)
429			((opcode_handler_t)OPLINE->handler)(ZEND_OPCODE_HANDLER_ARGS_PASSTHRU);
(gdb) s
ZEND_JMP_SPEC_HANDLER () at /root/php-7.1.0/Zend/zend_vm_execute.h:607
607		ZEND_VM_SET_OPCODE(OP_JMP_ADDR(opline, opline->op1));
(gdb) p ((zend_op*)(((char*)(opline)) + (int)(opline->op1).jmp_offset))
$35 = (zend_op *) 0x7ffff5e5fcc0
(gdb) n
608		ZEND_VM_CONTINUE();
(gdb)
609	}
(gdb)
execute_ex (ex=0x7ffff5e14030) at /root/php-7.1.0/Zend/zend_vm_execute.h:430
430			if (UNEXPECTED(!OPLINE)) {
(gdb) n
453		}
(gdb)
429			((opcode_handler_t)OPLINE->handler)(ZEND_OPCODE_HANDLER_ARGS_PASSTHRU);
(gdb) s
ZEND_FE_FETCH_R_SPEC_VAR_HANDLER () at /root/php-7.1.0/Zend/zend_vm_execute.h:16708
16708		array = EX_VAR(opline->op1.var);
(gdb) n
16709		SAVE_OPLINE();
(gdb) p array
$36 = (zval *) 0x7ffff5e140c0
(gdb) n
16710		if (EXPECTED(Z_TYPE_P(array) == IS_ARRAY)) {
(gdb)
16711			fe_ht = Z_ARRVAL_P(array);
(gdb)
16712			pos = Z_FE_POS_P(array);
(gdb)
16713			p = fe_ht->arData + pos;
(gdb) p pos
$37 = 1
(gdb) n
16715				if (UNEXPECTED(pos >= fe_ht->nNumUsed)) {
(gdb)
16719				value = &p->val;
(gdb)
16720				value_type = Z_TYPE_INFO_P(value);
(gdb)
16721				if (value_type == IS_UNDEF) {
(gdb)
16725				} else if (UNEXPECTED(value_type == IS_INDIRECT)) {
(gdb)
16734				break;
(gdb)
16736			Z_FE_POS_P(array) = pos + 1;
(gdb)
16737			if (opline->result_type & (IS_TMP_VAR|IS_CV)) {
(gdb) p array
$38 = (zval *) 0x7ffff5e140c0
(gdb) p *array
$39 = {value = {lval = 140737318847520, dval = 6.9533474330365409e-310, counted = 0x7ffff5e58420, str = 0x7ffff5e58420,
    arr = 0x7ffff5e58420, obj = 0x7ffff5e58420, res = 0x7ffff5e58420, ref = 0x7ffff5e58420, ast = 0x7ffff5e58420, zv = 0x7ffff5e58420,
    ptr = 0x7ffff5e58420, ce = 0x7ffff5e58420, func = 0x7ffff5e58420, ww = {w1 = 4125459488, w2 = 32767}}, u1 = {v = {type = 7 '\a',
      type_flags = 28 '\034', const_flags = 0 '\000', reserved = 0 '\000'}, type_info = 7175}, u2 = {next = 2, cache_slot = 2,
    lineno = 2, num_args = 2, fe_pos = 2, fe_iter_idx = 2, access_flags = 2, property_guard = 2}}
(gdb) n
16738				if (!p->key) {
(gdb)
16739					ZVAL_LONG(EX_VAR(opline->result.var), p->h);
(gdb) p p->h
$40 = 1
(gdb) p opline->result.var
$41 = 160
(gdb) p ((zval*)(((char*)(execute_data)) + ((int)(opline->result.var))))
$42 = (zval *) 0x7ffff5e140d0
(gdb) n
16856		if (EXPECTED(opline->op2_type == IS_CV)) {
(gdb)
16857			zval *variable_ptr = _get_zval_ptr_cv_undef_BP_VAR_W(execute_data, opline->op2.var);
(gdb)
16858			zend_assign_to_variable(variable_ptr, value, IS_CV);
(gdb) p variable_ptr
$43 = (zval *) 0x7ffff5e14090
(gdb) p *variable_ptr
$44 = {value = {lval = 1, dval = 4.9406564584124654e-324, counted = 0x1, str = 0x1, arr = 0x1, obj = 0x1, res = 0x1, ref = 0x1,
    ast = 0x1, zv = 0x1, ptr = 0x1, ce = 0x1, func = 0x1, ww = {w1 = 1, w2 = 0}}, u1 = {v = {type = 4 '\004', type_flags = 0 '\000',
      const_flags = 0 '\000', reserved = 0 '\000'}, type_info = 4}, u2 = {next = 0, cache_slot = 0, lineno = 0, num_args = 0,
    fe_pos = 0, fe_iter_idx = 0, access_flags = 0, property_guard = 0}}
(gdb) n
16868		ZEND_VM_NEXT_OPCODE();
(gdb) p *(zval*)0x7ffff5e14090
$45 = {value = {lval = 2, dval = 9.8813129168249309e-324, counted = 0x2, str = 0x2, arr = 0x2, obj = 0x2, res = 0x2, ref = 0x2,
    ast = 0x2, zv = 0x2, ptr = 0x2, ce = 0x2, func = 0x2, ww = {w1 = 2, w2 = 0}}, u1 = {v = {type = 4 '\004', type_flags = 0 '\000',
      const_flags = 0 '\000', reserved = 0 '\000'}, type_info = 4}, u2 = {next = 0, cache_slot = 0, lineno = 0, num_args = 0,
    fe_pos = 0, fe_iter_idx = 0, access_flags = 0, property_guard = 0}}
(gdb) n
16869	}
(gdb)
execute_ex (ex=0x7ffff5e14030) at /root/php-7.1.0/Zend/zend_vm_execute.h:430
430			if (UNEXPECTED(!OPLINE)) {
(gdb)
453		}
(gdb)
429			((opcode_handler_t)OPLINE->handler)(ZEND_OPCODE_HANDLER_ARGS_PASSTHRU);
(gdb) s
ZEND_ASSIGN_SPEC_CV_TMP_RETVAL_UNUSED_HANDLER () at /root/php-7.1.0/Zend/zend_vm_execute.h:40733
40733		SAVE_OPLINE();
(gdb) n
40734		value = _get_zval_ptr_tmp(opline->op2.var, execute_data, &free_op2);
(gdb)
40735		variable_ptr = _get_zval_ptr_cv_undef_BP_VAR_W(execute_data, opline->op1.var);
(gdb) p value
$46 = (zval *) 0x7ffff5e140d0
(gdb) p *value
$47 = {value = {lval = 1, dval = 4.9406564584124654e-324, counted = 0x1, str = 0x1, arr = 0x1, obj = 0x1, res = 0x1, ref = 0x1,
    ast = 0x1, zv = 0x1, ptr = 0x1, ce = 0x1, func = 0x1, ww = {w1 = 1, w2 = 0}}, u1 = {v = {type = 4 '\004', type_flags = 0 '\000',
      const_flags = 0 '\000', reserved = 0 '\000'}, type_info = 4}, u2 = {next = 0, cache_slot = 0, lineno = 0, num_args = 0,
    fe_pos = 0, fe_iter_idx = 0, access_flags = 0, property_guard = 0}}
(gdb) n
40743			value = zend_assign_to_variable(variable_ptr, value, IS_TMP_VAR);
(gdb) p variable_ptr
$48 = (zval *) 0x7ffff5e140a0
(gdb) n
40751		ZEND_VM_NEXT_OPCODE_CHECK_EXCEPTION();
(gdb)
40752	}
(gdb)
execute_ex (ex=0x7ffff5e14030) at /root/php-7.1.0/Zend/zend_vm_execute.h:430
430			if (UNEXPECTED(!OPLINE)) {
(gdb)
453		}
(gdb)
429			((opcode_handler_t)OPLINE->handler)(ZEND_OPCODE_HANDLER_ARGS_PASSTHRU);
(gdb) s
ZEND_ECHO_SPEC_CV_HANDLER () at /root/php-7.1.0/Zend/zend_vm_execute.h:34640
34640		SAVE_OPLINE();
(gdb) n
34641		z = _get_zval_ptr_cv_undef(execute_data, opline->op1.var);
(gdb)
34643		if (Z_TYPE_P(z) == IS_STRING) {
(gdb) p z
$49 = (zval *) 0x7ffff5e14090
(gdb) p *z
$50 = {value = {lval = 2, dval = 9.8813129168249309e-324, counted = 0x2, str = 0x2, arr = 0x2, obj = 0x2, res = 0x2, ref = 0x2,
    ast = 0x2, zv = 0x2, ptr = 0x2, ce = 0x2, func = 0x2, ww = {w1 = 2, w2 = 0}}, u1 = {v = {type = 4 '\004', type_flags = 0 '\000',
      const_flags = 0 '\000', reserved = 0 '\000'}, type_info = 4}, u2 = {next = 0, cache_slot = 0, lineno = 0, num_args = 0,
    fe_pos = 0, fe_iter_idx = 0, access_flags = 0, property_guard = 0}}
(gdb) n
34650			zend_string *str = _zval_get_string_func(z);
(gdb)
34652			if (ZSTR_LEN(str) != 0) {
(gdb)
34653				zend_write(ZSTR_VAL(str), ZSTR_LEN(str));
(gdb)
234657			zend_string_release(str);
(gdb)
34660		ZEND_VM_NEXT_OPCODE_CHECK_EXCEPTION();
(gdb)
34661	}
(gdb)
execute_ex (ex=0x7ffff5e14030) at /root/php-7.1.0/Zend/zend_vm_execute.h:430
430			if (UNEXPECTED(!OPLINE)) {
(gdb)
453		}
(gdb)
429			((opcode_handler_t)OPLINE->handler)(ZEND_OPCODE_HANDLER_ARGS_PASSTHRU);
(gdb) s
ZEND_JMP_SPEC_HANDLER () at /root/php-7.1.0/Zend/zend_vm_execute.h:607
607		ZEND_VM_SET_OPCODE(OP_JMP_ADDR(opline, opline->op1));
(gdb) p ((zend_op*)(((char*)(opline)) + (int)(opline->op1).jmp_offset))
$51 = (zend_op *) 0x7ffff5e5fcc0
(gdb) n
608		ZEND_VM_CONTINUE();
(gdb)
609	}
(gdb)
execute_ex (ex=0x7ffff5e14030) at /root/php-7.1.0/Zend/zend_vm_execute.h:430
430			if (UNEXPECTED(!OPLINE)) {
(gdb)
453		}
(gdb)
429			((opcode_handler_t)OPLINE->handler)(ZEND_OPCODE_HANDLER_ARGS_PASSTHRU);
(gdb) s
ZEND_FE_FETCH_R_SPEC_VAR_HANDLER () at /root/php-7.1.0/Zend/zend_vm_execute.h:16708
16708		array = EX_VAR(opline->op1.var);
(gdb) n
16709		SAVE_OPLINE();
(gdb)
16710		if (EXPECTED(Z_TYPE_P(array) == IS_ARRAY)) {
(gdb)
16711			fe_ht = Z_ARRVAL_P(array);
(gdb)
16712			pos = Z_FE_POS_P(array);
(gdb)
16713			p = fe_ht->arData + pos;
(gdb) p pos
$52 = 2
(gdb) p p
$53 = (Bucket *) 0x7ffff5e64980
(gdb) p *p
$54 = {val = {value = {lval = 140737318898176, dval = 6.9533474355392798e-310, counted = 0x7ffff5e64a00, str = 0x7ffff5e64a00,
      arr = 0x7ffff5e64a00, obj = 0x7ffff5e64a00, res = 0x7ffff5e64a00, ref = 0x7ffff5e64a00, ast = 0x7ffff5e64a00, zv = 0x7ffff5e64a00,
      ptr = 0x7ffff5e64a00, ce = 0x7ffff5e64a00, func = 0x7ffff5e64a00, ww = {w1 = 4125510144, w2 = 32767}}, u1 = {v = {type = 0 '\000',
        type_flags = 0 '\000', const_flags = 0 '\000', reserved = 0 '\000'}, type_info = 0}, u2 = {next = 0, cache_slot = 0, lineno = 0,
      num_args = 0, fe_pos = 0, fe_iter_idx = 0, access_flags = 0, property_guard = 0}}, h = 1, key = 0x32}
(gdb) n
16715				if (UNEXPECTED(pos >= fe_ht->nNumUsed)) {
(gdb) p pos
$55 = 2
(gdb) p fe_ht->nNumUsed
$56 = 2
(gdb) n
16717					goto fe_fetch_r_exit;
(gdb) n
16852			ZEND_VM_SET_RELATIVE_OPCODE(opline, opline->extended_value);
(gdb) p opline
$57 = (const zend_op * volatile) 0x7ffff5e5fcc0
(gdb) p *opline
$58 = {handler = 0x8d27fe <ZEND_FE_FETCH_R_SPEC_VAR_HANDLER>, op1 = {constant = 144, var = 144, num = 144, opline_num = 144,
    jmp_offset = 144}, op2 = {constant = 96, var = 96, num = 96, opline_num = 96, jmp_offset = 96}, result = {constant = 160, var = 160,
    num = 160, opline_num = 160, jmp_offset = 160}, extended_value = 128, lineno = 3, opcode = 78 'N', op1_type = 4 '\004',
  op2_type = 16 '\020', result_type = 2 '\002'}
(gdb) p ((zend_op*)(((char*)(opline)) + (int)opline->extended_value))
$59 = (zend_op *) 0x7ffff5e5fd40
(gdb) p ((zend_op*)(((char*)(opline)) + (int)128))
$60 = (zend_op *) 0x7ffff5e5fd40
(gdb) n
16853			ZEND_VM_CONTINUE();
(gdb)
16869	}
(gdb)
execute_ex (ex=0x7ffff5e14030) at /root/php-7.1.0/Zend/zend_vm_execute.h:430
430			if (UNEXPECTED(!OPLINE)) {
(gdb)
453		}
(gdb)
429			((opcode_handler_t)OPLINE->handler)(ZEND_OPCODE_HANDLER_ARGS_PASSTHRU);
(gdb) s
ZEND_FE_FREE_SPEC_TMPVAR_HANDLER () at /root/php-7.1.0/Zend/zend_vm_execute.h:51425
51425		SAVE_OPLINE();
(gdb) n
51426		var = EX_VAR(opline->op1.var);
(gdb)
51427		if (Z_TYPE_P(var) != IS_ARRAY && Z_FE_ITER_P(var) != (uint32_t)-1) {
(gdb) p var
$61 = (zval *) 0x7ffff5e140c0
(gdb) n
51430		zval_ptr_dtor_nogc(var);
(gdb)
51431		ZEND_VM_NEXT_OPCODE_CHECK_EXCEPTION();
(gdb) p var
$62 = (zval *) 0x7ffff5e140c0
(gdb) p *var
$63 = {value = {lval = 140737318847520, dval = 6.9533474330365409e-310, counted = 0x7ffff5e58420, str = 0x7ffff5e58420,
    arr = 0x7ffff5e58420, obj = 0x7ffff5e58420, res = 0x7ffff5e58420, ref = 0x7ffff5e58420, ast = 0x7ffff5e58420, zv = 0x7ffff5e58420,
    ptr = 0x7ffff5e58420, ce = 0x7ffff5e58420, func = 0x7ffff5e58420, ww = {w1 = 4125459488, w2 = 32767}}, u1 = {v = {type = 7 '\a',
      type_flags = 28 '\034', const_flags = 0 '\000', reserved = 0 '\000'}, type_info = 7175}, u2 = {next = 2, cache_slot = 2,
    lineno = 2, num_args = 2, fe_pos = 2, fe_iter_idx = 2, access_flags = 2, property_guard = 2}}
(gdb) p $63.value.arr
$64 = (zend_array *) 0x7ffff5e58420
(gdb) p *$63.value.arr
$65 = {gc = {refcount = 2, u = {v = {type = 7 '\a', flags = 0 '\000', gc_info = 0}, type_info = 7}}, u = {v = {flags = 30 '\036',
      nApplyCount = 0 '\000', nIteratorsCount = 0 '\000', consistency = 0 '\000'}, flags = 30}, nTableMask = 4294967294,
  arData = 0x7ffff5e5fa08, nNumUsed = 2, nNumOfElements = 2, nTableSize = 8, nInternalPointer = 0, nNextFreeElement = 2,
  pDestructor = 0x84d18f <_zval_ptr_dtor_wrapper>}
(gdb) n
51432	}
(gdb)
execute_ex (ex=0x7ffff5e14030) at /root/php-7.1.0/Zend/zend_vm_execute.h:430
430			if (UNEXPECTED(!OPLINE)) {
(gdb)
453		}
(gdb)
429			((opcode_handler_t)OPLINE->handler)(ZEND_OPCODE_HANDLER_ARGS_PASSTHRU);
(gdb) s
ZEND_RETURN_SPEC_CONST_HANDLER () at /root/php-7.1.0/Zend/zend_vm_execute.h:2858
2858		retval_ptr = EX_CONSTANT(opline->op1);
(gdb)

php 部分语法的AST、栈、符号表、和指令集

php 部分语法的AST、栈、符号表、和指令集

break 语法的AST、栈、符号表和指令集

先写一个测试脚本 break.php

gdb调试过程：

抽象语法树：

栈、符号表和常量

指令集

实战 文件的引入实现

先编写两个文件 1.php

include gdb

include AST

栈 符号表 和常量

指令集

条件判断语法实现

先编写文件 condition.php

AST 语法树

栈 符号表 常量

指令集

实战：循环语法实现

先编写文件 foreach.php

AST 语法树

栈 符号表 和 常量

指令集

执行过程gdb

实战文件的引入实现

栈符号表和常量

先编写文件 `condition.php`

栈符号表常量

先编写文件 `foreach.php`

栈符号表和常量