On July 19, 2021 6:13:40 PM GMT+02:00, Hafiz Abid Qadeer
<abid_qad...@mentor.com> wrote:
>On 19/07/2021 11:45, Richard Biener wrote:
>> On Fri, Jul 16, 2021 at 10:23 PM Hafiz Abid Qadeer
>> <abid_qad...@mentor.com> wrote:
>>>
>>> On 15/07/2021 13:09, Richard Biener wrote:
>>>> On Thu, Jul 15, 2021 at 12:35 PM Hafiz Abid Qadeer
>>>> <abid_qad...@mentor.com> wrote:
>>>>>
>>>>> On 15/07/2021 11:33, Thomas Schwinge wrote:
>>>>>>
>>>>>>> Note that the "parent" should be abstract but I don't think
>dwarf has a
>>>>>>> way to express a fully abstract parent of a concrete instance
>child - or
>>>>>>> at least how GCC expresses this causes consumers to
>"misinterpret"
>>>>>>> that. I wonder if adding a DW_AT_declaration to the late DWARF
>>>>>>> emitted "parent" would fix things as well here?
>>>>>>
>>>>>> (I suppose not, Abid?)
>>>>>>
>>>>>
>>>>> Yes, adding DW_AT_declaration does not fix the problem.
>>>>
>>>> Does emitting
>>>>
>>>> DW_TAG_compile_unit
>>>> DW_AT_name ("<artificial>")
>>>>
>>>> DW_TAG_subprogram // notional parent function (foo) with no code
>range
>>>> DW_AT_declaration 1
>>>> a: DW_TAG_subprogram // offload function foo._omp_fn.0
>>>> DW_AT_declaration 1
>>>>
>>>> DW_TAG_subprogram // offload function
>>>> DW_AT_abstract_origin a
>>>> ...
>>>>
>>>> do the trick? The following would do this, flattening function
>definitions
>>>> for the concrete copies:
>>>>
>>>> diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
>>>> index 82783c4968b..a9c8bc43e88 100644
>>>> --- a/gcc/dwarf2out.c
>>>> +++ b/gcc/dwarf2out.c
>>>> @@ -6076,6 +6076,11 @@ maybe_create_die_with_external_ref (tree
>decl)
>>>> /* Peel types in the context stack. */
>>>> while (ctx && TYPE_P (ctx))
>>>> ctx = TYPE_CONTEXT (ctx);
>>>> + /* For functions peel the context up to namespace/TU scope. The
>abstract
>>>> + copies reveal the true nesting. */
>>>> + if (TREE_CODE (decl) == FUNCTION_DECL)
>>>> + while (ctx && TREE_CODE (ctx) == FUNCTION_DECL)
>>>> + ctx = DECL_CONTEXT (ctx);
>>>> /* Likewise namespaces in case we do not want to emit DIEs for
>them. */
>>>> if (debug_info_level <= DINFO_LEVEL_TERSE)
>>>> while (ctx && TREE_CODE (ctx) == NAMESPACE_DECL)
>>>> @@ -6099,8 +6104,7 @@ maybe_create_die_with_external_ref (tree
>decl)
>>>> /* Leave function local entities parent determination to
>when
>>>> we process scope vars. */
>>>> ;
>>>> - else
>>>> - parent = lookup_decl_die (ctx);
>>>> + parent = lookup_decl_die (ctx);
>>>> }
>>>> else
>>>> /* In some cases the FEs fail to set DECL_CONTEXT properly.
>>>>
>>>
>>> Thanks. This solves the problem. Only the first hunk was required.
>Second hunk
>>> actually causes an ICE when TREE_CODE (ctx) == BLOCK.
>>> OK to commit the attached patch?
>>
>> I think we need to merge the TYPE_P peeling and FUNCTION_DECL peeling
>into
>> one loop since I suppose we can have a nested function in class
>scope.
>> So sth like
>>
>> diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
>> index 82783c4968b..61228410b51 100644
>> --- a/gcc/dwarf2out.c
>> +++ b/gcc/dwarf2out.c
>> @@ -6073,8 +6073,12 @@ maybe_create_die_with_external_ref (tree decl)
>> }
>> else
>> ctx = DECL_CONTEXT (decl);
>> - /* Peel types in the context stack. */
>> - while (ctx && TYPE_P (ctx))
>> + /* Peel types in the context stack. For functions peel the
>context up
>> + to namespace/TU scope. The abstract copies reveal the true
>nesting. */
>> + while (ctx
>> + && (TYPE_P (ctx)
>> + || (TREE_CODE (decl) == FUNCTION_DECL
>> + && TREE_CODE (ctx) == FUNCTION_DECL)))
>> ctx = TYPE_CONTEXT (ctx);
>> /* Likewise namespaces in case we do not want to emit DIEs for
>them. */
>> if (debug_info_level <= DINFO_LEVEL_TERSE)
>>
>This causes an ICE,
>internal compiler error: tree check: expected class 'type', have
>'declaration' (function_decl)
>
>Did you intend something like this:
>
>diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
>index 561f8b23517..c61f0041fba 100644
>--- a/gcc/dwarf2out.c
>+++ b/gcc/dwarf2out.c
>@@ -6121,3 +6121,8 @@ maybe_create_die_with_external_ref (tree decl)
>- /* Peel types in the context stack. */
>- while (ctx && TYPE_P (ctx))
>- ctx = TYPE_CONTEXT (ctx);
>+ /* Peel types in the context stack. For functions peel the context
>up
>+ to namespace/TU scope. The abstract copies reveal the true
>nesting. */
>+ while (ctx
>+ && (TYPE_P (ctx)
>+ || (TREE_CODE (decl) == FUNCTION_DECL
>+ && TREE_CODE (ctx) == FUNCTION_DECL)))
>+ ctx = TYPE_P (ctx) ? TYPE_CONTEXT (ctx) : DECL_CONTEXT (ctx);
>+
Yes, of course.
>
>> if that works it's OK. Can you run it on the gdb testsuite with
>-flto added
>> as well please (you need to do before/after comparison since IIRC
>adding
>> -flto will add a few fails).
>>
>> Thanks,
>> Richard.
>>
