http://www.laruence.com/2008/09/23/539.html
PHP提供了一個Embed SAPI，也就是說，PHP容許你在C/C++語言中調用PHP/ZE提供的函數。本文就通過基于Embed SAPI實現一個PHP的opcodes查看器。
首先，下載PHP源碼以供編譯， 我現在使用的是PHP5.3 alpha2
進入源碼目錄：
- ./configure --enable-embed --with-config-file-scan-dir=/etc/php.d --with-mysql --with-config-file-path=/etc/
- ./make
- ./make instal
最后，記得要將生成的libphp5.so復制到運行時庫的目錄，我直接拷貝到了/lib/, 否則會在運行你自己的embed程序的時候報錯：
- ./embed: error while loading shared libraries: libphp5.so: cannot open shared object file: No such file or director
如果你對PHP的SAPI還不熟悉的話，我建議你看看我的這篇文章：深入理解Zend SAPIs(Zend SAPI Internals)
這個時候，你就可以在你的C代碼中，嵌入PHP腳本解析器了， 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，一個簡單的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) $(LDFLAGS
編譯成功以后， 運行，我們可以看到， stdout輸出 Hello World！
基于這個，我們就可以很容易的實現一個類似于vld的Opcodes dumper：
首先我們定義opcode的轉換函數（全部的opcodes可以查看Zend/zend_vm_opcodes.h）；
- char *opname(zend_uchar opcode){
- switch(opcode) {
- case ZEND_NOP: return "ZEND_NOP"; break;
- case ZEND_ADD: return "ZEND_ADD"; break;
- case ZEND_SUB: return "ZEND_SUB"; break;
- case ZEND_MUL: return "ZEND_MUL"; break;
- case ZEND_DIV: return "ZEND_DIV"; break;
- case ZEND_MOD: return "ZEND_MOD"; break;
- case ZEND_SL: return "ZEND_SL"; break;
- case ZEND_SR: return "ZEND_SR"; break;
- case ZEND_CONCAT: return "ZEND_CONCAT"; break;
- case ZEND_BW_OR: return "ZEND_BW_OR"; break;
- case ZEND_BW_AND: return "ZEND_BW_AND"; break;
- case ZEND_BW_XOR: return "ZEND_BW_XOR"; break;
- case ZEND_BW_NOT: return "ZEND_BW_NOT"; break;
-
- default : return "UNKNOW"; break;
然后定義zval和znode的輸出函數：
- char *format_zval(zval *z)
- {
- static char buffer[BUFFER_LEN];
- int len;
-
- switch(z->type) {
- case IS_NULL:
- return "NULL";
- case IS_LONG:
- case IS_BOOL:
- snprintf(buffer, BUFFER_LEN, "%d", z->value.lval);
- return buffer;
- case IS_DOUBLE:
- snprintf(buffer, BUFFER_LEN, "%f", z->value.dval);
- return buffer;
- case IS_STRING:
- snprintf(buffer, BUFFER_LEN, "\"%s\"", z->value.str.val);
- return buffer;
- case IS_ARRAY:
- case IS_OBJECT:
- case IS_RESOURCE:
- case IS_CONSTANT:
- case IS_CONSTANT_ARRAY:
- return "";
- default:
- return "unknown";
- }
- }
-
- char * format_znode(znode *n){
- static char buffer[BUFFER_LEN];
-
- switch (n->op_type) {
- case IS_CONST:
- return format_zval(&n->u.constant);
- break;
- case IS_VAR:
- snprintf(buffer, BUFFER_LEN, "$%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;
- }
- }
-
然后定義op_array的輸出函數：
- 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，就是程序的主函數了：
- 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;
- }
編譯，運行測試腳本(sample.php):
sample.php:
- echo "laruence";
命令：
- ./opcodes_dumper sample.ph
得到輸出結果(如果你對下面的結果很迷惑，那么建議你再看看我的這篇文章：深入理解PHP原理之Opcodes）：
- Script: sample.php
- opnum line opcode op1 op2 result
- 0 2 ZEND_ECHO "laruence"
- 1 4 ZEND_RETURN
呵呵，怎么樣，是不是很好玩呢？
源碼地址：http://code.google.com/p/opcodesdumper/