2 files changed, 63 insertions, 34 deletions

diff --git a/src/ir/comp.rs b/src/ir/comp.rs
index d57c272a..e554f9a8 100644
--- a/src/ir/comp.rs
+++ b/src/ir/comp.rs
@@ -1113,21 +1113,17 @@ impl CompInfo {
         }
 
         // empty union case
-        if self.fields().is_empty() {
+        if !self.has_fields() {
             return None;
         }
 
         let mut max_size = 0;
         // Don't allow align(0)
         let mut max_align = 1;
-        for field in self.fields() {
-            let field_layout = field.layout(ctx);
-
-            if let Some(layout) = field_layout {
-                max_size = cmp::max(max_size, layout.size);
-                max_align = cmp::max(max_align, layout.align);
-            }
-        }
+        self.each_known_field_layout(ctx, |layout| {
+            max_size = cmp::max(max_size, layout.size);
+            max_align = cmp::max(max_align, layout.align);
+        });
 
         Some(Layout::new(max_size, max_align))
     }
@@ -1139,12 +1135,49 @@ impl CompInfo {
             CompFields::AfterComputingBitfieldUnits { ref fields, .. } => {
                 fields
             }
-            CompFields::BeforeComputingBitfieldUnits(_) => {
+            CompFields::BeforeComputingBitfieldUnits(..) => {
                 panic!("Should always have computed bitfield units first");
             }
         }
     }
 
+    fn has_fields(&self) -> bool {
+        match self.fields {
+            CompFields::ErrorComputingBitfieldUnits => false,
+            CompFields::AfterComputingBitfieldUnits { ref fields, .. } => {
+                !fields.is_empty()
+            }
+            CompFields::BeforeComputingBitfieldUnits(ref raw_fields) => {
+                !raw_fields.is_empty()
+            }
+        }
+    }
+
+    fn each_known_field_layout(
+        &self,
+        ctx: &BindgenContext,
+        mut callback: impl FnMut(Layout),
+    ) {
+        match self.fields {
+            CompFields::ErrorComputingBitfieldUnits => return,
+            CompFields::AfterComputingBitfieldUnits { ref fields, .. } => {
+                for field in fields.iter() {
+                    if let Some(layout) = field.layout(ctx) {
+                        callback(layout);
+                    }
+                }
+            }
+            CompFields::BeforeComputingBitfieldUnits(ref raw_fields) => {
+                for field in raw_fields.iter() {
+                    let field_ty = ctx.resolve_type(field.0.ty);
+                    if let Some(layout) = field_ty.layout(ctx) {
+                        callback(layout);
+                    }
+                }
+            }
+        }
+    }
+
     fn has_bitfields(&self) -> bool {
         match self.fields {
             CompFields::ErrorComputingBitfieldUnits => false,
@@ -1598,23 +1631,17 @@ impl CompInfo {
         // Even though `libclang` doesn't expose `#pragma packed(...)`, we can
         // detect it through its effects.
         if let Some(parent_layout) = layout {
-            if self.fields().iter().any(|f| match *f {
-                Field::Bitfields(ref unit) => {
-                    unit.layout().align > parent_layout.align
-                }
-                Field::DataMember(ref data) => {
-                    let field_ty = ctx.resolve_type(data.ty());
-                    field_ty.layout(ctx).map_or(false, |field_ty_layout| {
-                        field_ty_layout.align > parent_layout.align
-                    })
-                }
-            }) {
+            let mut packed = false;
+            self.each_known_field_layout(ctx, |layout| {
+                packed = packed || layout.align > parent_layout.align;
+            });
+            if packed {
                 info!("Found a struct that was defined within `#pragma packed(...)`");
                 return true;
-            } else if self.has_own_virtual_method {
-                if parent_layout.align == 1 {
-                    return true;
-                }
+            }
+
+            if self.has_own_virtual_method && parent_layout.align == 1 {
+                return true;
             }
         }
 
@@ -1627,10 +1654,13 @@ impl CompInfo {
     }
 
     /// Compute this compound structure's bitfield allocation units.
-    pub fn compute_bitfield_units(&mut self, ctx: &BindgenContext) {
-        // TODO(emilio): If we could detect #pragma packed here we'd fix layout
-        // tests in divide-by-zero-in-struct-layout.rs
-        self.fields.compute_bitfield_units(ctx, self.packed_attr)
+    pub fn compute_bitfield_units(
+        &mut self,
+        ctx: &BindgenContext,
+        layout: Option<&Layout>,
+    ) {
+        let packed = self.is_packed(ctx, layout);
+        self.fields.compute_bitfield_units(ctx, packed)
     }
 
     /// Assign for each anonymous field a generated name.
diff --git a/src/ir/context.rs b/src/ir/context.rs
index 4faf6cd1..72ce06b1 100644
--- a/src/ir/context.rs
+++ b/src/ir/context.rs
@@ -981,12 +981,11 @@ If you encounter an error missing from this list, please file an issue or a PR!"
             mem::replace(&mut self.need_bitfield_allocation, vec![]);
         for id in need_bitfield_allocation {
             self.with_loaned_item(id, |ctx, item| {
-                item.kind_mut()
-                    .as_type_mut()
-                    .unwrap()
-                    .as_comp_mut()
+                let ty = item.kind_mut().as_type_mut().unwrap();
+                let layout = ty.layout(ctx);
+                ty.as_comp_mut()
                     .unwrap()
-                    .compute_bitfield_units(ctx);
+                    .compute_bitfield_units(ctx, layout.as_ref());
             });
         }
     }