Can I relink a executable to collapse multiple sections into one

Can I relink a executable to collapse multiple sections into one

[陈云星]

After Linker linked the executable contains following sections:

27 .data.rel.ro.local 002a2660  000000000ad74f40  000000000ad74f40  0a974f40  2**6                                                           
                  CONTENTS, ALLOC, LOAD, DATA
 28 memory_context_static_id 00000008  000000000b0175a0  000000000b0175a0  0ac175a0  2**3                                                     
                  CONTENTS, ALLOC, LOAD, DATA
 29 memory_context_static_idz 00000008  000000000b0175a8  000000000b0175a8  0ac175a8  2**3                                                    
                  CONTENTS, ALLOC, LOAD, DATA
 30 memory_context_static_id5 00000010  000000000b0175b0  000000000b0175b0  0ac175b0  2**3                                                    
                  CONTENTS, ALLOC, LOAD, DATA
 31 memory_context_static_id8 000000d8  000000000b0175c0  000000000b0175c0  0ac175c0  2**3                                                    
                  CONTENTS, ALLOC, LOAD, DATA
 32 memory_context_static_id2 00000020  000000000b017698  000000000b017698  0ac17698  2**3                                                    
                  CONTENTS, ALLOC, LOAD, DATA
 33 CO_HOOK_BEGIN 00000020  000000000b0176c0  000000000b0176c0  0ac176c0  2**5                                                                
                  CONTENTS, ALLOC, LOAD, DATA
 34 CO_HOOK_END   00000020  000000000b0176e0  000000000b0176e0  0ac176e0  2**5                                                                
                  CONTENTS, ALLOC, LOAD, DATA
 35 memory_context_static_id0 00000008  000000000b017700  000000000b017700  0ac17700  2**3                                                    
                  CONTENTS, ALLOC, LOAD, DATA  
 36 memory_context_static_id11 00000060  000000000b017708  000000000b017708  0ac17708  2**3                                                   
                  CONTENTS, ALLOC, LOAD, DATA  
 37 memory_context_static_id17 00000008  000000000b017768  000000000b017768  0ac17768  2**3                                                   
                  CONTENTS, ALLOC, LOAD, DATA  
 38 memory_context_static_id9 00000010  000000000b017770  000000000b017770  0ac17770  2**3                                                    
                  CONTENTS, ALLOC, LOAD, DATA  
 39 memory_context_static_id12 00000008  000000000b017780  000000000b017780  0ac17780  2**3                                                   
                  CONTENTS, ALLOC, LOAD, DATA  
 40 memory_context_static_id14 00000008  000000000b017788  000000000b017788  0ac17788  2**3                                                   
                  CONTENTS, ALLOC, LOAD, DATA  
 41 CO_BUFFER_BEGIN 00000004  000000000b017790  000000000b017790  0ac17790  2**2                                                              
                  CONTENTS, ALLOC, LOAD, DATA  
 42 CO_BUFFER_END 00000004  000000000b017794  000000000b017794  0ac17794  2**2

What I want to do was collapse “memory_context_static_*”  into one section “memory_context_static”;

Is there some method let the linker to relink this executable file to do such job ?

Re: Can I relink a executable to collapse multiple sections into one

[Nick Clifton]

Hi 陈云星

> After Linker linked the executable contains following sections:
> What I want to do was collapse “memory_context_static_*”  into one section “memory_context_static”;
> 
> Is there some method let the linker to relink this executable file to do such job ?

It would be better to have this happen during the initial link, if at all possible.
To do this simply create a linker script fragment like this:

   SECTIONS {
    .memory_context_static_id : { *(.memory_context_static_id .memory_context_static_id*) }
   }

and then include it on the linker command line.

Relinking an already fully linked binary is going to be difficult, and I would not
recommend it if you can avoid it.

Cheers
   Nick

Re: Can I relink a executable to collapse multiple sections into one

[陈云星]

because we want use another linker to do some work the current linker not supported；

i use gold linker to reorder functiom sections which bfd linker not supported，and than use lld or bfd to collect several  special section into one section this step can not be done with gold linker, because of its not support custom ld script; 

发自我的iPhone

> 在 2021年5月18日，上午12:36，Nick Clifton <nickc@redhat.com> 写道：
> 
> Hi 陈云星
> 
>> After Linker linked the executable contains following sections:
>> What I want to do was collapse “memory_context_static_*”  into one section “memory_context_static”;
>> Is there some method let the linker to relink this executable file to do such job ?
> 
> It would be better to have this happen during the initial link, if at all possible.
> To do this simply create a linker script fragment like this:
> 
>  SECTIONS {
>   .memory_context_static_id : { *(.memory_context_static_id .memory_context_static_id*) }
>  }
> 
> and then include it on the linker command line.
> 
> Relinking an already fully linked binary is going to be difficult, and I would not
> recommend it if you can avoid it.
> 
> Cheers
>  Nick
> 
> 

Re: Can I relink a executable to collapse multiple sections into one

[Alan Modra]

On Sat, May 15, 2021 at 03:35:29PM +0800, 陈云星 via Binutils wrote:
> Is there some method let the linker to relink this executable file to do such job ?

No, not unless you have the relocatable objects and libraries
available that created this executable.

-- 
Alan Modra
Australia Development Lab, IBM