Re: Re: GCC link problem help!

[桂永林 <guiyonglin@huaqin.com>]

Hello Xi Ruoyao,
   Thanks for your reply! I can confirm that our hardware can work well, since if I link another C lib to replace the C++ lib with same function, the program can work well. So, I guess this problem maybe related with my c++ lib, and the only difference is that the c++ lib is build by G++ and g++linker. 
   If there is some special parameter we need check, when we link the c++ lib to C program with C linker? 
Thanks!
Best regards, 
Operagui




发件人：Xi Ruoyao <xry111@mengyan1223.wang>
发送时间：2021-10-21 00:17
主题：Re: GCC link problem help!
收件人："桂永林/图灵研究院软件三部/图灵研究院"<guiyonglin@huaqin.com>,"LIU Hao"<lh_mouse@126.com>,"Tom Kacvinsky"<tkacvins@gmail.com>
抄送："gcc-help"<gcc-help@gcc.gnu.org>,"柳茂昕/图灵研究院软件三部/图灵研究院"<liumaoxin@huaqin.com>,"李闯闯/图灵研究院软件三部/图灵研究院"<lichuangchuang@huaqin.com>,"汤汝/图灵研究院软件三部/图灵研究院"<tangru@huaqin.com>
 
On Wed, 2021-10-20 at 22:53 +0800, 桂永林 wrote: 
> Hellow Tom and Liu Hao, 
>    We encounter another GCC link problem. Our hardware is cotex-M33 
> platform,  our software project development on windows environment and 
> use GCC compiler and the gcc-linker as bellow: 
>  
>  
>    gcc version 7.3.1 20180622 (release) [ARM/embedded-7-branch 
> revision 261907] (GNU Tools for Arm Embedded Processors 7-2018-q2- 
> update) 
>  
>    GCC: GNU ISO C11  7 2018-q2-update  
>  
>    GCC parameter:  -std=gnu11 
>  
>    gcc-linker parameter: --specs=nano.specs --specs=nosys.specs 
>     
>    Our project need link a C++ static lib into our project. The C++ 
> lib build enviroment as bellow: 
>    G++：GNU ISO 2011 C++ 
>    G++ parameter：-std=gnu++11 -fabi-version=0 -fno-exceptions -fno- 
> rtti -fno-use-cxa-atexit -fno-non-call-exceptions 
>  
>  
>  
>    But we found that if we linked the C++ static lib to our program, 
> then the program have runtime logic problem sometimes. If we do not 
> link the C++ lib, it can run well. We can not understand why the 
> reason. We guess, if maybe some gcc linker parameter need used when we 
> need link the C++ lib?  
 
>    Can you give us some suggest about how to fix this problem!    
 
I think it will be very difficult to tell. Maybe there is some 
undefined behavior (for example, out-of-bound access) in your program 
and linking in libstdc++ just changes the memory layout or something and 
exploits the issue. The undefined behavior may be even triggered by 
some hardware problem for a embedded system... (I once debugged my 
program for one day and then found out one capacitor was simply too 
small!) 
--  
Xi Ruoyao <xry111@mengyan1223.wang> 
School of Aerospace Science and Technology, Xidian University