当前位置：首页 → 问答吧 → 使用PHP Embed SAPI实现Opcodes查看器

使用PHP Embed SAPI实现Opcodes查看器

时间：2008-09-23

来源：互联网

· 作者:laruence(http://www.laruence.com/)
· 本文地址: http://www.laruence.com/2008/09/23/539.html
· 转载请注明出处
PHP提供了一个Embed SAPI，也就是说，PHP容许你在C/C++语言中调用PHP/ZE提供的函数。本文就通过基于Embed SAPI实现一个PHP的opcodes查看器。
首先，下载PHP源码以供编译，我现在使用的是PHP5.3 alpha2
进入源码目录：

./configure --enable-embed
./make
./make install

最后，记得要将生成的libphp5.so复制到运行时库的目录，我直接拷贝到了/lib/, 否则会在运行你自己的embed程序的时候报错：

./embed: error while loading shared libraries: libphp5.so: cannot open shared object file: No such file or directory

如果你对PHP的SAPI还不熟悉的话，我建议你看看我的这篇文章：深入理解Zend SAPIs(Zend SAPI Internals)
这个时候，你就可以在你的C代码中，嵌入PHP脚本解析器了，我的例子：

#include "sapi/embed/php_embed.h"

int main(int argc, char * argv[]){
   PHP_EMBED_START_BLOCK(argc,argv);
   char * script = " print 'Hello World!';";
   zend_eval_string(script, NULL,
   "Simple Hello World App" TSRMLS_CC);
   PHP_EMBED_END_BLOCK();
   return 0;
}

然后就是要指明include path了，一个简单的Makefile

CC = gcc
CFLAGS = -I/usr/local/include/php/ \
   -I/usr/local/include/php/main \
   -I/usr/local/include/php/Zend \
   -I/usr/local/include/php/TSRM \
   -Wall -g
LDFLAGS = -lstdc++ -L/usr/local/lib -lphp5
ALL:
   $(CC) -o embed embed.cpp $(CFLAGS) $(LDFLAGS)

编译成功以后，运行，我们可以看到， stdout输出 Hello World！
基于这个，我们就可以很容易的实现一个类似于vld的Opcodes dumper：
首先我们定义opcode的转换函数（全部的opcodes可以查看Zend/zend_vm_opcodes.h）；

char *opname(zend_uchar opcode){
   switch(opcode) {
   case ZEND_NOP: return "ZEND_NOP"; break;
   case ZEND_ADD: return "ZEND_ADD"; break;
   case ZEND_SUB: return "ZEND_SUB"; break;
   case ZEND_MUL: return "ZEND_MUL"; break;
   case ZEND_DIV: return "ZEND_DIV"; break;
   case ZEND_MOD: return "ZEND_MOD"; break;
   case ZEND_SL: return "ZEND_SL"; break;
   case ZEND_SR: return "ZEND_SR"; break;
   case ZEND_CONCAT: return "ZEND_CONCAT"; break;
   case ZEND_BW_OR: return "ZEND_BW_OR"; break;
   case ZEND_BW_AND: return "ZEND_BW_AND"; break;
   case ZEND_BW_XOR: return "ZEND_BW_XOR"; break;
   case ZEND_BW_NOT: return "ZEND_BW_NOT"; break;
   /*...省略 ....*/
   default : return "UNKNOW"; break;

然后定义zval和znode的输出函数：

char *format_zval(zval *z)
{
   static char buffer[BUFFER_LEN];
   int len;

   switch(z->type) {
   case IS_NULL:
   return "NULL";
   case IS_LONG:
   case IS_BOOL:
   snprintf(buffer, BUFFER_LEN, "%d", z->value.lval);
   return buffer;
   case IS_DOUBLE:
   snprintf(buffer, BUFFER_LEN, "%f", z->value.dval);
   return buffer;
   case IS_STRING:
   snprintf(buffer, BUFFER_LEN, "\"%s\"", z->value.str.val);
   return buffer;
   case IS_ARRAY:
   case IS_OBJECT:
   case IS_RESOURCE:
   case IS_CONSTANT:
   case IS_CONSTANT_ARRAY:
   return "";
   default:
   return "unknown";
   }
}

char * format_znode(znode *n){
   static char buffer[BUFFER_LEN];

   switch (n->op_type) {
   case IS_CONST:
   return format_zval(&n->u.constant);
   break;
   case IS_VAR:
   snprintf(buffer, BUFFER_LEN, "$%d",  n->u.var/sizeof(temp_variable));
   return buffer;
   break;
   case IS_TMP_VAR:
   snprintf(buffer, BUFFER_LEN, "~%d",  n->u.var/sizeof(temp_variable));
   return buffer;
   break;
   default:
   return "";
   break;
   }
}

然后定义op_array的输出函数：

void dump_op(zend_op *op, int num){
   printf("%5d %5d %30s %040s %040s %040s\n", num, op->lineno,
   opname(op->opcode),
   format_znode(&op->op1),
   format_znode(&op->op2),
   format_znode(&op->result)) ;
}

void dump_op_array(zend_op_array *op_array){
   if(op_array) {
   int i;
   printf("%5s %5s %30s %040s %040s %040s\n", "opnum", "line", "opcode", "op1", "op2", "result");
   for(i = 0; i < op_array->last; i++) {
   dump_op(&op_array->opcodes[i], i);
   }
   }
}

最后，就是程序的主函数了：

int main(int argc, char **argv){
   zend_op_array *op_array;
   zend_file_handle file_handle;

   if(argc != 2) {
   printf("usage: op_dumper <script>\n");
   return 1;
   }
   PHP_EMBED_START_BLOCK(argc,argv);
   printf("Script: %s\n", argv[1]);
   file_handle.filename = argv[1];
   file_handle.free_filename = 0;
   file_handle.type = ZEND_HANDLE_FILENAME;
   file_handle.opened_path = NULL;
   op_array =  zend_compile_file(&file_handle, ZEND_INCLUDE TSRMLS_CC);
   if(!op_array) {
   printf("Error parsing script: %s\n", file_handle.filename);
   return 1;
   }
   dump_op_array(op_array);
   PHP_EMBED_END_BLOCK();
   return 0;
}