Re: [Tinycc-devel] libtcc (dll) doesn't work for memory output...

[grischka]

Gabriel Corneanu wrote:
> Hello,
>
> I am using libtcc to generate some dynamic code; simple example:
>
> int foo(int n1, int n2){ return n1+n2; }
>
> It used to work using tcc_set_options(FState, "-nostdlib"), 
> tcc_compile_string, tcc_get_symbol("foo") then call it...
>
> The current state doesn't work anymore like before...
>
> 1. "nostdlib" is not properly used somewhere in pe_output_file / 
> pe_add_runtime; it always searches for some startup code (start_symbol).
> the error is 'tcc: error: _runmain not defined', and then it calls 
> tcc_error as explained at #2 (exit!)
> 2. some compile errors (see #1) reach "tcc_error" where 
> error_set_jmp_enabled is 0, therefore terminating my program!
>
> I modified pe_output_file by using
> if(!s1->nostdlib) pe_add_runtime(s1, &pe);
> This seems to work for me, but I'm not sure if it's the best solution.
> E.g if I still need the stdlib for "printf", I get back to the same problem
>
> 3. Why do I NEED a startup code for memory output? I extract my symbols 
> and call the functions directly.
> The workaround is to have dummy "runmain", and "main" ...

Yes, there is the problem because for TCC_OUTPUT_MEMORY the
pe_add_runtime() function is supposed to serve two different
cases, that is
1) "tcc -run" or tcc_run() (which is expected to define main)
2) usage of libtcc with custom function as in libtcc_test.
Unfortunately pe_add_runtime() cannot know whether 1) or 2) is
wanted.

Anyway, it should now work again as it did before:
    http://repo.or.cz/w/tinycc.git/commitdiff/13b997668e32a4

There are probably still some odd cases, for example you cannot
use -nostdlib and still link the startup code from libtcc1, as
in
    tcc foo.c -nostdlib -ltcc1

--- grischka

> Regards,
> Gabriel