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From: Michael S <already5chosen@yahoo.com>
Newsgroups: comp.lang.c
Subject: Re: C23 thoughts and opinions
Date: Thu, 30 May 2024 17:51:07 +0300
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On Thu, 30 May 2024 17:08:36 +0300
Michael S <already5chosen@yahoo.com> wrote:

> On Thu, 30 May 2024 14:34:00 +0100
> bart <bc@freeuk.com> wrote:
> 
> > On 30/05/2024 03:32, Lawrence D'Oliveiro wrote:  
> > > On Wed, 29 May 2024 13:58:20 +0200, Bonita Montero wrote:
> > >     
> > >> I've got a small commandline-tool that makes a const'd char
> > >> -array from any binary file.    
> > > 
> > > It seems to me it would be more efficient to use objcopy to turn
> > > that binary file directly into an object file with symbols
> > > accessible from C code defining its beginning and ending points.
> > > Then just link it into the executable.    
> > 
> > None of my compilers, whether for C or anything else, generate
> > object files.
> > 
> > However, suppose I wanted to link a file called 'logo.bmp' say, into
> > my program, which consisted of a file called main.c.
> > 
> > What is the entire process using your suggestion? What do I put
> > into main.c? Assume the data is represented by a char-array.
> >   
> 
> extern unsigned char _binary_logo_bmp_start[];
> extern unsigned char _binary_logo_bmp_size[];
> 
> The first symbol is an array itself.
> The seconded symbol contains the length of array. You use it in
> somewhat non-intuitive way:
>   size_t my_size = (size_t)_binary_logo_bmp_size;
> 
> Pay attention that I never used this method myself, just took a look
> at the output of objcopy with 'objdump -t', so please don't take my
> words as a sure thing.
> 
> BTW, options in this case are rather simple:
> objcopy -I binary -O elf32-little logo.bmp logo_bmp.o
> Replace elf32-little with relevant format for your software. However I
> am not sure that it would work for none-elf output formats. 
>

Tested it.
On msys2 it can produce correct pe-x86-64 format but does it in
counter-intuitive way: you have to ask for elf64-x86-64 instead of
pe-x86-64.
I don't know why it works like that. 

The rest of what I wrote above was correct.