[debug-early,jit] Port of jit to debug-early

"jit" isn't part of "all" languages, and currently fails to build on
the aldyh/debug-early branch:

../../src/gcc/jit/jit-playback.c: In member function ‘void gcc::jit::playback::context::write_global_decls_2()’:
../../src/gcc/jit/jit-playback.c:710:20: error: ‘const struct gcc_debug_hooks’ has no member named ‘global_decl’
       debug_hooks->global_decl (decl);

This patch (on top of today's 1a07de5e93cc9e18d899a6a1b7d01436167ab1b1)
fixes the build of the jit.

"make check-jit" works, with:
      # of expected passes            7609

I verified the debuggability of jitted code by hand by

  (a) running jit.dg/test-using-globals.c
      and inspecting globals, and

  (b) running jit.dg/test-fibonacci.c and
      single-stepping through the code in gdb:

      (gdb) break my_fibonacci
      (gdb) run
      Breakpoint 1, my_fibonacci (x=10) at /home/david/coding-3/gcc-git-jit-early-debug/src/gcc/testsuite/jit.dg/test-fibonacci.c:19
      19	FIRST_LINE + 3:   if (x < 2)
      (gdb) next
      16	FIRST_LINE + 0: int
      (gdb) next
      19	FIRST_LINE + 3:   if (x < 2)
      (gdb) next
      22	FIRST_LINE + 6:     return my_fibonacci (x - 1) + my_fibonacci (x - 2);

OK for your branch?

gcc/jit/ChangeLog:
	* dummy-frontend.c (jit_langhook_write_globals): Rename to...
	(jit_langhook_post_compilation_parsing_cleanups): ...this, and
	eliminate calls to finalize_compilation_unit and
	write_global_decls_2.
	(LANG_HOOKS_WRITE_GLOBALS): Rename to...
	(LANG_HOOKS_POST_COMPILATION_PARSING_CLEANUPS): ...this and
	redirect from jit_langhook_write_globals to
	jit_langhook_post_compilation_parsing_cleanups.
	* jit-playback.c
	(gcc::jit::playback::context::write_global_decls_1): Rename to...
	(gcc::jit::playback::context::finalize_global_decls): ...this.
	(gcc::jit::playback::context::write_global_decls_1): Delete.
	* jit-playback.h
	(gcc::jit::playback::context::write_global_decls_1): Rename to...
	(gcc::jit::playback::context::finalize_global_decls): ...this.
	(gcc::jit::playback::context::write_global_decls_1): Delete.
---
 gcc/jit/dummy-frontend.c | 14 +++++---------
 gcc/jit/jit-playback.c   | 25 ++-----------------------
 gcc/jit/jit-playback.h   |  4 +---
 3 files changed, 8 insertions(+), 35 deletions(-)

On 06/05/2015 03:00 PM, David Malcolm wrote:
> "jit" isn't part of "all" languages, and currently fails to build on
> the aldyh/debug-early branch:

The debug-early work is now in mainline.  Feel free to commit when you 
deem appropriate, since you are the jit maintainer ;-).

>   static void
> -jit_langhook_write_globals (void)
> +jit_langhook_post_compilation_parsing_cleanups (void)
>   {
>     gcc::jit::playback::context *ctxt = gcc::jit::active_playback_ctxt;
>     gcc_assert (ctxt);
>     JIT_LOG_SCOPE (ctxt->get_logger ());
>
> -  ctxt->write_global_decls_1 ();
> -
> -  /* This is the hook that runs the middle and backends: */
> -  symtab->finalize_compilation_unit ();
> -
> -  ctxt->write_global_decls_2 ();
> +  ctxt->finalize_global_decls ();

This hook gets called after the compilation proper has run, and we're 
trying to avoid it.  We're trying to get all the front-ends to finish 
their thing and avoid depending on the compilation proper.

Can you not get this to work without running finalize_global_decls after 
the compilation proper?  If not, then I see no problem with your 
patch....after all, C++ is still using this hook :(.

Thanks for working on this.

Aldy

On Fri, 2015-06-05 at 15:37 -0400, Aldy Hernandez wrote:
> On 06/05/2015 03:00 PM, David Malcolm wrote:
> > "jit" isn't part of "all" languages, and currently fails to build on
> > the aldyh/debug-early branch:
> 
> The debug-early work is now in mainline.  Feel free to commit when you 
> deem appropriate, since you are the jit maintainer ;-).

Given that it fixes the build of the jit, I've gone ahead and committed
the patch as-is to trunk (r224170).

> >   static void
> > -jit_langhook_write_globals (void)
> > +jit_langhook_post_compilation_parsing_cleanups (void)
> >   {
> >     gcc::jit::playback::context *ctxt = gcc::jit::active_playback_ctxt;
> >     gcc_assert (ctxt);
> >     JIT_LOG_SCOPE (ctxt->get_logger ());
> >
> > -  ctxt->write_global_decls_1 ();
> > -
> > -  /* This is the hook that runs the middle and backends: */
> > -  symtab->finalize_compilation_unit ();
> > -
> > -  ctxt->write_global_decls_2 ();
> > +  ctxt->finalize_global_decls ();
> 
> This hook gets called after the compilation proper has run, and we're 
> trying to avoid it.  We're trying to get all the front-ends to finish 
> their thing and avoid depending on the compilation proper.
> 
> Can you not get this to work without running finalize_global_decls after 
> the compilation proper?  If not, then I see no problem with your 
> patch....after all, C++ is still using this hook :(.

Am investigating.

Thanks
Dave