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Re: [PATCH] Non-working jit patch for debug-early (was Re: [patch 0/10] debug-early merge)


On 05/08/2015 10:38 AM, David Malcolm wrote:

I tested your branch (at 09263eae7c260c305fa19ffa186afd1d89654fb8) with
the jit configuration from the docs:

../src/configure \
  --enable-host-shared \
    --enable-languages=jit,c++ \
    --disable-bootstrap \
    --enable-checking=release \
    --prefix=$PREFIX

Sadly, the jit "frontend" fails to compile:

Whoops. My bad. I was unaware `jit' needed to be added to --enable-languages. I thought it was tested automatically.


../../src/gcc/jit/jit-playback.c: In member function âvoid
gcc::jit::playback::context::write_global_decls_2()â:
../../src/gcc/jit/jit-playback.c:710:20: error: âconst struct
gcc_debug_hooksâ has no member named âglobal_declâ
        debug_hooks->global_decl (decl);

The basic idea is that if your globals do NOT make it to rest_of_decl_compilation(), you need to call debug_hooks->early_global_decl() on them manually after parsing.

On the other hand, if your functions do NOT make it to the symbol table then you also need to call debug_hooks->early_global_decl() on them after parsing (see finalize_compilation_unit()).

The call to debug_hooks->late_global_decl() should be handled automagically. I mean, I assume your symbols (functions and globals, etc) make it to the symbol table, in which case they'll be picked up by either compile_file() or by analyze_functions(). The latter in case the symbol was optimized away and is about to be removed from the symbol table.

Does this help?  If it doesn't, I can gladly take over this on Monday.

                     ^
since the "global_decl" debug hook has gone away.  I see that
   LANG_HOOKS_WRITE_GLOBALS
also is no more, and this leads to various code in the jit becoming
dead:
../../src/gcc/jit/dummy-frontend.c:225:1: warning: âvoid
jit_langhook_write_globals()â defined but not used [-Wunused-function]


The attached patch gets it to compile, and eliminates the now-dead code,
but it's not clear to me how global variables are meant to be created in
the debug-early world.

Thanks for working on this.

Aldy


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