BUG: fix eplicit_padding when a struct ends in a bitfield.

A struct ending in a bitfield will have its trailing padding duplicated. This change skips adding the trailing padding if the last field was a bitfield, and thus, already has already been padded.
rust-lang · Feb 9, 2023 · d59c82a · d59c82a
1 parent ae68172
commit d59c82a
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diff --git a/bindgen-tests/tests/expectations/tests/explicit-padding.rs b/bindgen-tests/tests/expectations/tests/explicit-padding.rs
diff --git a/bindgen-tests/tests/headers/explicit-padding.h b/bindgen-tests/tests/headers/explicit-padding.h
@@ -15,3 +15,8 @@ union dont_pad_me {
         uint32_t second;
         uint16_t third;
 };
+
+struct also_pad_me {
+        uint16_t first;
+        uint8_t bits: 1;
+};
diff --git a/bindgen/codegen/struct_layout.rs b/bindgen/codegen/struct_layout.rs
@@ -285,6 +285,11 @@ impl<'a> StructLayoutTracker<'a> {
             return None;
         }
 
+        // If the last field was a bitfield, it will already have been padded.
+        if self.last_field_was_bitfield {
+            return None;
+        }
+
         // Padding doesn't make sense for rust unions.
         if self.is_rust_union {
             return None;