From 68aa8a8d0b3f219551a004ea9a637768e6a38755 Mon Sep 17 00:00:00 2001
From: Quentin JEROME <qjerome@users.noreply.github.com>
Date: Fri, 24 Feb 2023 21:23:10 +0100
Subject: [PATCH] Fixed bug:  - duplicated members under some conditions (it
 was not causing any functional issue)

Signed-off-by: Quentin JEROME <qjerome@users.noreply.github.com>
---
 aya-obj/src/btf/helpers.rs | 29 +++++++++++++++++++----------
 1 file changed, 19 insertions(+), 10 deletions(-)

diff --git a/aya-obj/src/btf/helpers.rs b/aya-obj/src/btf/helpers.rs
index 17df2f5b..fd289a2f 100644
--- a/aya-obj/src/btf/helpers.rs
+++ b/aya-obj/src/btf/helpers.rs
@@ -78,13 +78,20 @@ impl StructHelper {
 
                 match member_type {
                     BtfType::Struct(_) => {
-                        // we push the structure name
-                        self.members.push(MemberHelper::new(
-                            p.clone(),
-                            member_offset,
-                            member_type.clone(),
-                            None,
-                        ));
+                        // in case of structure containing an unamed union and again
+                        // a struct the algorithm creates duplicates members so
+                        // we need to check if we aleady have the member before insertion.
+                        // this is not optimal, it would be better in a hashmap
+                        if !self.contains_member(p.to_string()) {
+                            // we push the structure name
+                            self.members.push(MemberHelper::new(
+                                p.clone(),
+                                member_offset,
+                                member_type.clone(),
+                                None,
+                            ));
+                        }
+
                         // we process all members of the structure
                         self.resolve_members_rec(btf, member_type, &p, member_offset)?;
                     }
@@ -121,9 +128,6 @@ impl StructHelper {
 
                 // members of unions all have the same offset
                 if !matches!(t.kind(), BtfKind::Union) {
-                    // a zero member_size is an issue as two members
-                    // will have the same offsets
-                    debug_assert_ne!(member_size, 0);
                     member_offset += member_size;
                 }
             }
@@ -155,6 +159,11 @@ impl StructHelper {
         self.members.iter().find(|m| m.is_path(path))
     }
 
+    #[inline]
+    pub(crate) fn contains_member<P: AsRef<str>>(&self, path: P) -> bool {
+        self.get_member(path).is_some()
+    }
+
     /// Returns the size of the [`StructHelper`]. This might not be the real size of
     /// the structure as it does not take alignement into account. In order to have
     /// the size of aligned structure use [`size_of_aligned`] method.