调用al_draw_filled_rectangle时触发Segmentation fault问题求助

我编写了一个在蓝色背景上绘制黑色正方形的简单Allegro测试程序，用于验证环境安装配置是否正确，编译命令如下：

g++ -I "C:\msys64\mingw64\include\" test.cpp -o test.exe -g -lallegro -lallegro_primitives

测试代码：

#include <allegro5/allegro5.h>
#include <allegro5/allegro_primitives.h>

#include <iostream>

int main(int argc, char* argv[])
{
    al_init();
    
    ALLEGRO_DISPLAY* d = al_create_display(256, 256);
    
    if (d == NULL)
        std::cout << "Error in initializing display" << std::endl;
    
    al_clear_to_color(al_map_rgb(0, 0, 255));
    al_draw_filled_rectangle(64, 64, 192, 192, al_map_rgb(0, 0, 0));
    al_flip_display();
    
    al_rest(30);
    
    al_destroy_display(d);
    al_uninstall_system();
    return 0;
}

但使用gdb .\test.exe运行程序时，触发Segmentation fault错误，错误信息如下：

Thread 1 received signal SIGSEGV, Segmentation fault.
al_lock_mutex (mutex=0x0) at C:/dev/allegro_winpkg/universal/allegro/src/threads.c:325
warning: 325    C:/dev/allegro_winpkg/universal/allegro/src/threads.c: No such file or directory

完整堆栈跟踪：

#0  al_lock_mutex (mutex=0x0) at C:/dev/allegro_winpkg/universal/allegro/src/threads.c:325
#1  0x00007ffc351282bc in get_display_local_data (display=display@entry=0x616fa0)
    at C:/dev/allegro_winpkg/universal/allegro/addons/primitives/prim_directx.cpp:138
#2  0x00007ffc35129a4b in draw_prim_raw (target=0x617280, texture=0x0, vtx=0x5ffd90, decl=0x0, indices=0x0, num_vtx=4,
    type=5) at C:/dev/allegro_winpkg/universal/allegro/addons/primitives/prim_directx.cpp:500
#3  0x00007ffc3512a011 in _al_draw_prim_directx (target=target@entry=0x617280, texture=texture@entry=0x0,
    vtxs=vtxs@entry=0x5ffd90, decl=decl@entry=0x0, start=<optimized out>, start@entry=0, end=<optimized out>,
    end@entry=4, type=<optimized out>, type@entry=5)
    at C:/dev/allegro_winpkg/universal/allegro/addons/primitives/prim_directx.cpp:656
#4  0x00007ffc3512e048 in al_draw_prim (vtxs=0x5ffd90, decl=0x0, texture=0x0, start=0, end=4, type=5)
    at C:/dev/allegro_winpkg/universal/allegro/addons/primitives/primitives.c:104
#5  0x00007ffc35122784 in al_draw_filled_rectangle (x1=<optimized out>, y1=0, x2=<optimized out>, y2=0, color=...)
    at C:/dev/allegro_winpkg/universal/allegro/addons/primitives/high_primitives.c:422
#6  0x00007ff7a78f1553 in main (argc=1, argv=0xf61b60) at test.cpp:16

我猜测是MinGW配置过程中遗漏了某些步骤，但不知如何修复，恳请各位提供解决方案。

解决办法 #

从堆栈跟踪可以明确，崩溃的根源是未初始化Allegro的primitives附加库。Allegro的核心初始化al_init()只会初始化基础模块，像primitives这类附加库需要单独调用初始化函数。

具体修复步骤： #

1. 在al_init()之后添加al_init_primitives_addon();，完成primitives模块的初始化
2. 完善显示创建失败的处理逻辑——如果d == NULL，直接退出程序，避免后续调用依赖显示的函数引发更多错误

修改后的代码：

#include <allegro5/allegro5.h>
#include <allegro5/allegro_primitives.h>

#include <iostream>

int main(int argc, char* argv[])
{
    al_init();
    // 初始化primitives附加库
    al_init_primitives_addon();
    
    ALLEGRO_DISPLAY* d = al_create_display(256, 256);
    
    if (d == NULL) {
        std::cout << "Error in initializing display" << std::endl;
        // 显示创建失败，直接退出
        return 1;
    }
    
    al_clear_to_color(al_map_rgb(0, 0, 255));
    al_draw_filled_rectangle(64, 64, 192, 192, al_map_rgb(0, 0, 0));
    al_flip_display();
    
    al_rest(30);
    
    al_destroy_display(d);
    al_uninstall_system();
    return 0;
}

额外注意事项： #

• 确保编译时链接的库版本与头文件版本完全匹配，避免混合32位和64位库
• 如果仍然有问题，检查MinGW环境变量是否正确配置，确保编译器能找到Allegro的头文件和库文件

内容的提问来源于stack exchange，提问作者Jake Revell