Re: Incremental compilation

[Basile Starynkevitch <basile@starynkevitch.net>]

On 12/30/18 4:04 PM, Marc Nieper-Wißkirchen wrote:
> Am So., 30. Dez. 2018 um 13:28 Uhr schrieb Basile Starynkevitch
> <basile@starynkevitch.net>:
>
>
> You could, once all macros have been compiled, regenerate a single
> "shared object" for all your library, but that is an optimization. The
> main reason to do so would be to avoid wasting virtual address space by
> having many thousands of shared objects. I am not sure it is worthwhile.
> The reason why I would like to have a single shared object is for the
> convenience of the user. The compiler should produce a single shared
> object from a Scheme library definition which can then later be
> visited/invoked in lieu of loading the Scheme source code of the
> library.

Then you could compile twice the code.

Alternatively, you could compile each function once into a .pic.o
position-independent code object file. When doing the incremental compilation, you also need to convert each of these into its own .so file
(and you would fork a ld or gcc process for that; it should run quickly).

BTW, since libgccjit is really a wrapper above GCC, you could generate once the position-indenpendent code object files
(so usinggcc_jit_context_add_command_line_option to ask for -fPIC then using 
gcc_jit_context_compile_to_file) of each function. Then you would fork a 
gcc or ld process to link all these *.pic.o into a single .so; this 
would be reasonably quick. Take advantage that libgccjit is just a 
front-end to GCC. It fakes to be a JIT compiler, but it is not really 
one. Its main advantage is to avoid requiring you to emit C code in 
files. Cheers.
-- 
Basile STARYNKEVITCH   == http://starynkevitch.net/Basile
opinions are mine only - les opinions sont seulement miennes
Bourg La Reine, France