On Thu, Jul 15, 2021 at 12:35 PM Hafiz Abid Qadeer
<[email protected]> 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.
>
> --
> Hafiz Abid Qadeer
> Mentor, a Siemens Business
