我最近开始研究编写 PHP 扩展,并通读了这篇文章,它描述了使用 C++ 构建扩展的起点。当我开始定制时,我遇到了一个麻烦,试图将一些功能拆分到一个单独的文件中。一切编译和链接都没有问题,但是当我尝试实际使用扩展时出现错误。确切的信息是:
$ php -dextension=test.so -r "var_dump( new Test );"
php: symbol lookup error: /etc/php/ext/test.so: undefined symbol: _ZN9ContainerI4TestEC1EP17_zend_class_entry
我在两台电脑上试过,都遇到同样的问题。我知道它找不到 Container 构造函数的实际实现,但我不知道如何让它在正确的位置找到。
在发布到这里之前,我已经尝试尽可能多地去除绒毛,但是 php 接口代码中仍然存在很多杂乱无章的地方。代码如下:
配置.m4:
PHP_ARG_ENABLE(test,
[Whether to enable the "test" extension],
[ --enable-test Enable "test" extension support])
if test $PHP_TEST != "no"; then
PHP_REQUIRE_CXX()
PHP_SUBST(TEST_SHARED_LIBADD)
PHP_ADD_LIBRARY(stdc++, 1, TEST_SHARED_LIBADD)
PHP_NEW_EXTENSION(test, interface.cpp internals.cpp, $ext_shared)
fi
接口.h:
#ifndef INTERFACE_H_
#define INTERFACE_H_
#define PHP_TEST_EXTNAME "test"
#define PHP_TEST_EXTVER "0.1"
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#endif
接口.cpp:
#include "interface.h"
#include "internals.h"
#include "php.h"
class Test {};
extern zend_module_entry test_module_entry;
zend_object_handlers test_object_handlers;
zend_class_entry *test_ce;
void test_free_storage(void *object TSRMLS_DC)
{
delete (Container<Test> *) object;
}
zend_object_value test_create_handler( zend_class_entry* classInfo TSRMLS_DC )
{
Container<Test> *obj = new Container<Test>( classInfo );
zend_object_value retval;
retval.handle = zend_objects_store_put(
obj, NULL, test_free_storage, NULL TSRMLS_CC
);
retval.handlers = &test_object_handlers;
return retval;
}
PHP_METHOD(Test, __construct)
{
Test* test = new Test;
Container<Test> *obj = (Container<Test> *) zend_object_store_get_object(getThis() TSRMLS_CC);
obj->cpp = test;
}
function_entry test_methods[] = {
PHP_ME(Test, __construct, NULL, ZEND_ACC_PUBLIC | ZEND_ACC_CTOR)
{NULL, NULL, NULL}
};
PHP_MINIT_FUNCTION(test)
{
zend_class_entry ce;
INIT_CLASS_ENTRY(ce, "Test", test_methods);
test_ce = zend_register_internal_class(&ce TSRMLS_CC);
test_ce->create_object = test_create_handler;
memcpy(
&test_object_handlers,
zend_get_std_object_handlers(),
sizeof(zend_object_handlers)
);
test_object_handlers.clone_obj = NULL;
return SUCCESS;
}
zend_module_entry test_module_entry = {
STANDARD_MODULE_HEADER,
PHP_TEST_EXTNAME,
NULL, /* Functions */
PHP_MINIT(test), /* MINIT */
NULL, /* MSHUTDOWN */
NULL, /* RINIT */
NULL, /* RSHUTDOWN */
NULL, /* MINFO */
PHP_TEST_EXTVER,
STANDARD_MODULE_PROPERTIES
};
#ifdef COMPILE_DL_TEST
extern "C" {
ZEND_GET_MODULE(test)
}
#endif
内部结构.h:
#ifndef INTERNALS_H_
#define INTERNALS_H_
#include "zend.h"
template <class T>
class Container
{
private:
zend_object zend;
public:
T* cpp;
Container ( zend_class_entry* classInfo );
};
#endif /* INTERNALS_H_ */
内部结构.cpp
#include "internals.h"
#include "zend.h"
template <class T>
Container<T>::Container ( zend_class_entry* classInfo )
: zend()
{
zend.ce = classInfo;
}
我正在使用以下命令构建它:
$ phpize
$ ./configure --enable-test
$ make && make install
$ php -dextension=test.so -r "var_dump( new Test );"
谢谢你尽你所能的帮助