Re: [patch 10/10] debug-early merge: compiler proper

[Aldy Hernandez <aldyh@redhat.com>]

On 05/20/2015 05:01 PM, Jan Hubicka wrote:
>>
>> commit 8824b5ecba26cef065e47b34609c72677c3c36fc
>> Author: Aldy Hernandez <aldyh@redhat.com>
>> Date:   Wed May 20 16:31:14 2015 -0400
>>
>>      Set DECL_IGNORED_P on temporary arrays created in the switch
>>      conversion pass.
>>
>> diff --git a/gcc/tree-switch-conversion.c b/gcc/tree-switch-conversion.c
>> index 6b68a16..a4bcdba 100644
>> --- a/gcc/tree-switch-conversion.c
>> +++ b/gcc/tree-switch-conversion.c
>> @@ -1097,6 +1097,7 @@ build_one_array (gswitch *swtch, int num, tree
>> arr_index_type,
>>         DECL_ARTIFICIAL (decl) = 1;
>>         TREE_CONSTANT (decl) = 1;
>>         TREE_READONLY (decl) = 1;
>> +      DECL_IGNORED_P (decl) = 1;
>>         varpool_node::finalize_decl (decl);
>
> This looks obvious enough to me.  Technically speaking the array type constructed
> probalby should be TREE_ARTIFICAIL, but probably it does not matter.

Yeah, that's what I thought.  I ignored the type because it won't make 
it to the debugging back end if we stop things at the DECL itself.

FWIW, Ada is filled with these temporaries and/or types that should 
really be ignored, and are currently causing grief.

> If you grep for finalize_decl, there are several other calls:
> asan.c:      varpool_node::finalize_decl (var);
> asan.c:      varpool_node::finalize_decl (var);
> cgraphbuild.c:      varpool_node::finalize_decl (decl);
> cgraphunit.c:    - varpool_finalize_decl
> cgraphunit.c:   varpool_node::finalize_decl (decl);
> cgraphunit.c:varpool_node::finalize_decl (tree decl)
> coverage.c:           varpool_node::finalize_decl (var);
> coverage.c:  varpool_node::finalize_decl (var);

Etc etc.

Hmmm, I bet mainline is generating dwarf for all this.  I don't feel 
comfortable touching all this (ok, I'm lazy), but it would seem like 
almost all of these calls would benefit from DECL_IGNORED_P.  Perhaps we 
could add an argument to finalize_decl() and do it in there.

Aldy

> coverage.c:  varpool_node::finalize_decl (fn_info_ary);
> coverage.c:  varpool_node::finalize_decl (gcov_info_var);
> omp-low.c:        varpool_node::finalize_decl (t);
> omp-low.c:        varpool_node::finalize_decl (t);
> omp-low.c:        varpool_node::finalize_decl (decl);
> omp-low.c:      varpool_node::finalize_decl (vars_decl);
> omp-low.c:      varpool_node::finalize_decl (funcs_decl);
> passes.c:           varpool_node::finalize_decl (decl);
> tree-chkp.c:  varpool_node::finalize_decl (var);
> tree-chkp.c:  varpool_node::finalize_decl (bnd_var);
> tree-profile.c:  varpool_node::finalize_decl (ic_void_ptr_var);
> tree-profile.c:  varpool_node::finalize_decl (ic_gcov_type_ptr_var);
> tree-switch-conversion.c:      varpool_node::finalize_decl (decl);
> ubsan.c:  varpool_node::finalize_decl (decl);
> ubsan.c:  varpool_node::finalize_decl (var);
> ubsan.c:      varpool_node::finalize_decl (array);
> varasm.c:  varpool_node::finalize_decl (decl);
> varpool.c:   Unlike finalize_decl function is intended to be used
> varpool.c:  varpool_node::finalize_decl (decl);
>
> I would say most of them needs similar treatment (I am not 100% sure about OMP
> ones that may be user visible)
>
> Honza
>>
>>         fetch = build4 (ARRAY_REF, value_type, decl, tidx, NULL_TREE,