我得到一些模板和g ++ -Os的警告。 为什么？ 如何使用-Os -Winline删除这些警告？
编辑1 ：g ++ v4.6.1如果我用 unsigned int 替换 uint32_t ，我的主要错误已得到纠正:(此错误已被删除报告：http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52888）
Event.h:109:12: attention : inlining failed in call to ‘uint32_t Event<ParamT>::attach(ListenerT*, bool (ListenerT::*)(ParamT)) [with ListenerT = Listener, ParamT = unsigned int, uint32_t = unsigned int]’: mismatched arguments [-Winline]
编辑2 ：以下警告似乎是g ++错误（http://gcc.gnu.org/ml/gcc-help/2012-07/msg00029.html）（我没有〜播放器（））inlining failed in call to ‘Player::~Player()’: call is unlikely and code size would grow [-Winline]
编辑3 ：要删除上一个警告，请添加Player::~Player() __attribute__ ((noinline)) {}
测试代码： Event.h
#ifndef EVENT_H
#define EVENT_H
#include <map>
#include <stdint.h>
/***************************************************************************//*!
* @brief Collect Listener
* @tparam ParamT Param type of the function
*/
template<typename ParamT>
class EventHandlerBase
{
public:
virtual bool notify( ParamT param ) = 0;
};
/***************************************************************************//*!
* @brief Conteneur d'un receveur d'event.
* @tparam ListenerT Object type
* @tparam ParamT Param type of the function
*/
template<typename ListenerT, typename ParamT>
class EventHandler : public EventHandlerBase<ParamT>
{
private:
typedef bool (ListenerT::*PtrMember)(ParamT);
private:
ListenerT* m_object;//!< Object listener
PtrMember m_member;//!< Function listener
public:
/********************************************************************//*!
* @brief Constructor
* @param[in] object Instance listener
* @param[in] member Function listener ( Function need to be a public member of {object} )
* @return[NONE]
*/
EventHandler( ListenerT* object, PtrMember member )
{
m_object = object;
m_member = member;
}
/*******************************************************************//*!
* @brief Emit a signal to listeners
* @param[in] param Data
* @return FALSE for breaking event loop
*/
bool notify( ParamT param )
{
return (m_object->*m_member)(param);
}
};
/***************************************************************************//*!
* @brief Event system
* @tparam ParamT Param type of the function
*/
template<typename ParamT>
class Event
{
private:
typedef typename std::map< uint32_t, EventHandlerBase<ParamT>* > HandlersMap;
private:
HandlersMap m_handlers;//!< Contient la liste des instances::fonctions en écoute sur cet event
uint32_t m_counter;//!< Permet de gérer les id
public:
/********************************************************************//*!
* @brief Constructor
* @return[NONE]
*/
Event()
{
m_counter = 0;
}
/********************************************************************//*!
* @brief Destructor
* @return[NONE]
*/
~Event()
{
typename HandlersMap::iterator it = m_handlers.begin();
for(; it != m_handlers.end(); it++)
{
if( it->second )
delete it->second;
}
}
/*******************************************************************//*!
* @brief Link a function and instance to this event
* @param[in] object Instance listener
* @param[in] PtrMember Function listener ( Function need to be a public member of {object} )
* @return Connection ID
*
* @warning DO NOT FORGET TO CALL Event::detach(uint32_t) if you delete {object}
*/
template<typename ListenerT>
uint32_t attach( ListenerT* object, bool (ListenerT::*PtrMember)(ParamT) )
{
m_handlers[m_counter] = new EventHandler<ListenerT,ParamT>(object, PtrMember);
m_counter++;
return m_counter-1;
}
/*******************************************************************//*!
* @brief Emit a signal to listeners
* @param[in] param Data
* @return[NONE]
*/
void notify( ParamT param )
{
typename HandlersMap::iterator it = m_handlers.begin();
for(; it != m_handlers.end(); it++)
{
if( !it->second->notify(param) )
return ;
}
}
/*******************************************************************//*!
* @brief Unlink a listener.
* @param[in] id Connection ID from Event::attach
* @return TRUE if removed
*/
bool detach( uint32_t id )
{
typename HandlersMap::iterator it = m_handlers.find(id);
if( it == m_handlers.end() )
return false;
delete it->second;
m_handlers.erase(it);
return true;
}
};
#endif // EVENT_H
Main.cpp的
#include <stdio.h>
#include "Event.h"
class Player
{
public:
Event<uint32_t> e_speed;
private:
uint32_t m_speed;
public:
Player()
{
m_speed = 15;
}
void setSpeed( uint32_t speed )
{
m_speed = speed;
e_speed.notify(speed);
}
};
class Listener
{
private:
Player m_player;
public:
Listener()
{
m_player.e_speed.attach(this, &Listener::SLOT_speed);
}
bool SLOT_speed( uint32_t speed )
{
printf("Speed changed to %u\n", speed);
return true;
}
Player* player()
{
return &m_player;
}
};
int main()
{
Listener l;
l.player()->setSpeed(42);
return 0;
}
使用以下代码编译此代码： g ++ -Os -W -Wall -Winline * .cpp 你会收到这些警告：
Event.h:109:12: attention : inlining failed in call to ‘uint32_t Event<ParamT>::attach(ListenerT*, bool (ListenerT::*)(ParamT)) [with ListenerT = Listener, ParamT = unsigned int, uint32_t = unsigned int]’: mismatched arguments [-Winline]
main.cpp:32:56: attention : appelé d'ici [-Winline]
main.cpp:4:7: attention : inlining failed in call to ‘Player::~Player()’: call is unlikely and code size would grow [-Winline]
main.cpp:31:3: attention : appelé d'ici [-Winline]
main.cpp:4:7: attention : inlining failed in call to ‘Player::~Player()’: call is unlikely and code size would grow [-Winline]
main.cpp:24:7: attention : appelé d'ici [-Winline]
main.cpp:4:7: attention : inlining failed in call to ‘Player::~Player()’: call is unlikely and code size would grow [-Winline]
main.cpp:24:7: attention : appelé d'ici [-Winline]
答案 0 :(得分：4)
你的动机有点不清楚......
你想要警告消失吗？删除-Winline选项。这就是它的作用：它警告非内联内联函数。
您是否希望内联这些函数，即使代码可能变得更大/更慢？您将不得不使用启发式内联。您可以尝试以下几种方法：
__attribute__(always_inline)添加到相关功能。-finline-limit=N与N进行编译。--param NAME=VALUE。有几十个参数可以控制内联（max-inline-insns-single，max-inline-insns-auto，large-function-insns，inline-unit-growth等。）您可以阅读info gcc来获取详细信息。< / LI>
答案 1 :(得分：0)
似乎g ++在将它们用作模板参数之前扩展了typedef，但是在将它们与前者进行比较时，无法扩展未用作模板参数的typedef。
更简单的代码版本说明了这一点：
#include <iostream>
typedef unsigned int uint32_t;
template <typename T>
class Foo {
public :
template <typename C>
void fun(C* c, void (C::*f)(T)) {
(c->*f)(42);
}
};
class BarBad {
private :
Foo<uint32_t> foo;
public :
BarBad() {
foo.fun(this, &BarBad::fun);
}
void fun(uint32_t t) {
std::cout << t << std::endl;
}
};
template <typename T>
class BarGood {
private :
Foo<T> foo;
public :
BarGood() {
foo.fun(this, &BarGood<T>::fun);
}
void fun(T t) {
std::cout << t << std::endl;
}
};
int main(void) {
BarBad bb;
BarGood<uint32_t> bg;
return 0;
}
此代码仅针对BarBad代码发出警告：
test.cpp: In function ‘int main()’:
test.cpp:9: warning: inlining failed in call to ‘void Foo<T>::fun(C*, void (C::*)(T)) [with C = BarBad, T = unsigned int]’: function not considered for inlining
test.cpp:20: warning: called from here
在BarBad中，当调用Foo<uint32_t>::fun时，第二个参数的类型为void (BarBad::*)(uint32_t)，但被调用的函数需要void (BarBad::*)(unsigned int)，并且无法看到{{1} }和uint32_t是相同的类型。
在unsigned int中，当调用BarGood<uint32_t>时，第二个参数的类型为Foo<uint32_t>::fun，它与被调用函数所期望的匹配。
这对我来说感觉像编译器错误。有点搜索出现了这个错误报告：
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52888
我还没有测试过那里的解决方案是否也解决了这个问题，但听起来确实如此。