Abigail reader: update is-declaration-only handling comment

Under rare circumstances, libabigail, or perhaps only older versions of it, can
emit non-empty struct types with the `is-declaration-only` flag set. The flag in
turn comes from DWARF's `DW_AT_declaration` which cannot be interpreted in
isolation.

We also cannot rely on just the absence of children to detect forward declations
as this does not distinguish `struct foo;` from `struct foo {};`.

In any case, this comment is now clearer and shorter.

PiperOrigin-RevId: 528750564
Change-Id: Ie30b0229db7c6779619fee7f491d965be854d4f9

1 files changed, 2 insertions, 4 deletions

diff --git a/abigail_reader.cc b/abigail_reader.cc
index 0005af8..7329dc3 100644
--- a/abigail_reader.cc
+++ b/abigail_reader.cc
@@ -559,10 +559,8 @@ void Abigail::ProcessTypeDecl(Id id, xmlNodePtr type_decl) {
 
 void Abigail::ProcessStructUnion(Id id, bool is_struct,
                                  xmlNodePtr struct_union) {
-  // TODO
-  // Libabigail is reporting wrong information for is-declaration-only so it is
-  // not reliable. We are looking at the children of the element instead.
-  // It can be removed once the bug is fixed.
+  // Libabigail sometimes reports is-declaration-only but still provides some
+  // child elements. So we check both things.
   const bool forward =
       ReadAttribute<bool>(struct_union, "is-declaration-only", false)
       && Child(struct_union) == nullptr;