[PATCH][C] Always use TRANSLATION_UNIT_DECL as context

[Richard Guenther]

On Mon, 27 Sep 2010, Richard Guenther wrote:

> On Mon, 27 Sep 2010, Jie Zhang wrote:
> 
> > On 09/27/2010 05:25 PM, Richard Guenther wrote:
> > > so I guess we should instead try to not push builtins to the global
> > > scope.  Like with
> > > 
> > > Index: c-decl.c
> > > ===================================================================
> > > --- c-decl.c    (revision 164591)
> > > +++ c-decl.c    (working copy)
> > > @@ -1142,6 +1142,10 @@ pop_scope (void)
> > >                           "inline function %q+D declared but never
> > > defined", p);
> > >                DECL_EXTERNAL (p) = 1;
> > >              }
> > > +         else if (TREE_CODE (p) == FUNCTION_DECL
> > > +&&  DECL_BUILT_IN (p))
> > > +           /* Do not put builtin functions into the outermost BLOCK.  */
> > > +           continue;
> > > 
> > >            goto common_symbol;
> > > 
> > > 
> > > Joseph might have an idea here (I also see external_scope being used,
> > > but I'm not sure what functions actually end up in that).
> > > 
> > > Does the above help?
> > > 
> > This change fixed the original regression. But it caused some new ICEs. Like
> > 
> > Run cc1 under GDB:
> 
> Hm, I will later look into this.  Btw, as arm has vectorizing intrinsics
> it should better implement targetm.builtin_decl - that there is no
> LTO testcase using those builtins is no execuse for it to not do that ;)

It works on x86-64 if I comment its builtin_decl support with the
single expected FAIL of gcc.dg/lto/20090206-1_0.c
(which relies on proper target builtin streaming).

So I think this is ineed an issue of the backend not properly keeping
the builtins life if they are not used.

Richard.

> Richard.
> 
> > (gdb) set args -fpreprocessed memcpy-chk-lib.i -quiet -dumpbase
> > memcpy-chk-lib.c -auxbase memcpy-chk-lib -O3 -fomit-frame-pointer -o
> > memcpy-chk-lib.s
> > (gdb) r
> > Starting program: /home/jie/sources/gcc/builds/build-arm-eabi.git/gcc/cc1
> > -fpreprocessed memcpy-chk-lib.i -quiet -dumpbase memcpy-chk-lib.c -auxbase
> > memcpy-chk-lib -O3 -fomit-frame-pointer -o memcpy-chk-lib.s
> > 
> > Program received signal SIGSEGV, Segmentation fault.
> > 0x00000000004c0931 in gt_ggc_mx_c_binding (x_p=0x7ffff6f771e0) at
> > ./gt-c-decl.h:92
> > (gdb) bt
> > #0  0x00000000004c0931 in gt_ggc_mx_c_binding (x_p=0x7ffff6f771e0) at
> > ./gt-c-decl.h:92
> > #1  0x00000000004c3027 in gt_ggc_mx_lang_tree_node (x_p=0x7ffff6f40b90) at
> > ./gt-c-decl.h:561
> > #2  0x00000000004c215f in gt_ggc_mx_lang_tree_node (x_p=0x7ffff6f43700) at
> > ./gt-c-decl.h:370
> > #3  0x000000000084b4ff in gt_ggc_mx_cgraph_node (x_p=0x7ffff6f92000) at
> > gtype-desc.c:524
> > #4  0x0000000000851920 in gt_ggc_m_P11cgraph_node4htab (x_p=0x7ffff6e9e930) at
> > gtype-desc.c:2432
> > #5  0x00000000007e722f in ggc_mark_root_tab (rt=0x11afce0) at
> > ../../../git/gcc/ggc-common.c:159
> > #6  0x00000000007e72cb in ggc_mark_roots () at
> > ../../../git/gcc/ggc-common.c:178
> > #7  0x000000000059c45f in ggc_collect () at ../../../git/gcc/ggc-page.c:1950
> > #8  0x00000000008f74b9 in execute_todo (flags=2083) at
> > ../../../git/gcc/passes.c:1306
> > #9  0x00000000008f7cef in execute_one_pass (pass=0x166c180) at
> > ../../../git/gcc/passes.c:1592
> > #10 0x00000000008f7e1b in execute_pass_list (pass=0x166c180) at
> > ../../../git/gcc/passes.c:1624
> > #11 0x00000000008f7e3c in execute_pass_list (pass=0x166bfa0) at
> > ../../../git/gcc/passes.c:1625
> > #12 0x00000000008f7e3c in execute_pass_list (pass=0x166b640) at
> > ../../../git/gcc/passes.c:1625
> > #13 0x0000000000a7e6e4 in tree_rest_of_compilation (fndecl=0x7ffff6f2af00) at
> > ../../../git/gcc/tree-optimize.c:419
> > #14 0x0000000000cf1413 in cgraph_expand_function (node=0x7ffff6d952c0) at
> > ../../../git/gcc/cgraphunit.c:1477
> > #15 0x0000000000cf16ab in cgraph_expand_all_functions () at
> > ../../../git/gcc/cgraphunit.c:1556
> > #16 0x0000000000cf1cd0 in cgraph_optimize () at
> > ../../../git/gcc/cgraphunit.c:1812
> > #17 0x0000000000cef817 in cgraph_finalize_compilation_unit () at
> > ../../../git/gcc/cgraphunit.c:1020
> > #18 0x00000000004c044c in c_write_global_declarations () at
> > ../../../git/gcc/c-decl.c:9748
> > #19 0x00000000009eb15f in compile_file () at ../../../git/gcc/toplev.c:967
> > #20 0x00000000009ed64a in do_compile () at ../../../git/gcc/toplev.c:2394
> > #21 0x00000000009ed718 in toplev_main (argc=12, argv=0x7fffffffe1b8) at
> > ../../../git/gcc/toplev.c:2435
> > #22 0x0000000000593d8c in main (argc=12, argv=0x7fffffffe1b8) at
> > ../../../git/gcc/main.c:36
> > (gdb) l
> > 87	  struct c_binding * xlimit = x;
> > 88	  while (ggc_test_and_set_mark (xlimit))
> > 89	   xlimit = ((*xlimit).prev);
> > 90	  while (x != xlimit)
> > 91	    {
> > 92	      switch (TREE_CODE ((*x).decl) == LABEL_DECL)
> > 93	        {
> > 94	        case 0:
> > 95	          gt_ggc_m_9tree_node ((*x).u.type);
> > 96	          break;
> > (gdb) p *x
> > $1 = {u = {type = 0x0, label = 0x0}, decl = 0x0, id = 0x0, prev =
> > 0x7ffff6f77210, shadowed = 0x0, depth = 0, invisible = 0, nested = 0,
> > inner_comp = 0, in_struct = 0, locus = 0}
> > (gdb)
> > 
> > 
> > 
> 
> 

-- 
Richard Guenther <rguenther@suse.de>
Novell / SUSE Labs
SUSE LINUX Products GmbH - Nuernberg - AG Nuernberg - HRB 16746 - GF: Markus Rex