Auto merge of #1271 - emilio:repr-align, r=xidorn

codegen: Support repr(align)

Fixes #917.

1 files changed, 20 insertions, 4 deletions

diff --git a/src/codegen/mod.rs b/src/codegen/mod.rs
index 1801520a..a6ab3997 100644
--- a/src/codegen/mod.rs
+++ b/src/codegen/mod.rs
@@ -1527,6 +1527,7 @@ impl CodeGenerator for CompInfo {
             });
         }
 
+        let mut explicit_align = None;
         if is_opaque {
             // Opaque item should not have generated methods, fields.
             debug_assert!(fields.is_empty());
@@ -1534,6 +1535,8 @@ impl CodeGenerator for CompInfo {
 
             match layout {
                 Some(l) => {
+                    explicit_align = Some(l.align);
+
                     let ty = helpers::blob(l);
                     fields.push(quote! {
                         pub _bindgen_opaque_blob: #ty ,
@@ -1555,6 +1558,7 @@ impl CodeGenerator for CompInfo {
                     if layout.align == 1 {
                         packed = true;
                     } else {
+                        explicit_align = Some(layout.align);
                         let ty = helpers::blob(Layout::new(0, layout.align));
                         fields.push(quote! {
                             pub __bindgen_align: #ty ,
@@ -1637,6 +1641,18 @@ impl CodeGenerator for CompInfo {
             attributes.push(attributes::repr("C"));
         }
 
+        if ctx.options().rust_features().repr_align {
+            if let Some(explicit) = explicit_align {
+                // Ensure that the struct has the correct alignment even in
+                // presence of alignas.
+                let explicit = helpers::ast_ty::int_expr(explicit as i64);
+                attributes.push(quote! {
+                    #[repr(align(#explicit))]
+                });
+            }
+        }
+
+
         let mut derives = vec![];
         if item.can_derive_debug(ctx) {
             derives.push("Debug");
@@ -1655,7 +1671,7 @@ impl CodeGenerator for CompInfo {
         if item.can_derive_copy(ctx) && !item.annotations().disallow_copy() {
             derives.push("Copy");
 
-            if ctx.options().rust_features().builtin_clone_impls() ||
+            if ctx.options().rust_features().builtin_clone_impls ||
                 used_template_params.is_some()
             {
                 // FIXME: This requires extra logic if you have a big array in a
@@ -1996,7 +2012,7 @@ impl MethodCodegen for Method {
             _ => panic!("How in the world?"),
         };
 
-        if let (Abi::ThisCall, false) = (signature.abi(), ctx.options().rust_features().thiscall_abi()) {
+        if let (Abi::ThisCall, false) = (signature.abi(), ctx.options().rust_features().thiscall_abi) {
             return;
         }
 
@@ -3167,7 +3183,7 @@ impl TryToRustTy for FunctionSig {
         let abi = self.abi();
 
         match abi {
-            Abi::ThisCall if !ctx.options().rust_features().thiscall_abi() => {
+            Abi::ThisCall if !ctx.options().rust_features().thiscall_abi => {
                 warn!("Skipping function with thiscall ABI that isn't supported by the configured Rust target");
                 Ok(quote::Tokens::new())
             }
@@ -3264,7 +3280,7 @@ impl CodeGenerator for Function {
         }
 
         let abi = match signature.abi() {
-            Abi::ThisCall if !ctx.options().rust_features().thiscall_abi() => {
+            Abi::ThisCall if !ctx.options().rust_features().thiscall_abi => {
                 warn!("Skipping function with thiscall ABI that isn't supported by the configured Rust target");
                 return;
             }