Fix docstring comment for constants

Author: Nico Chatzi

src/codegen/mod.rs

@@ -618,12 +618,18 @@ impl CodeGenerator for Var {
             return;
         }
 
+        let mut attrs = vec![];
+        if let Some(comment) = item.comment(ctx) {
+            attrs.push(attributes::doc(comment));
+        }
+
         let ty = self.ty().to_rust_ty_or_opaque(ctx, &());
 
         if let Some(val) = self.val() {
             match *val {
                 VarType::Bool(val) => {
                     result.push(quote! {
+                        #(#attrs)*
                         pub const #canonical_ident : #ty = #val ;
                     });
                 }
@@ -643,6 +649,7 @@ impl CodeGenerator for Var {
                         helpers::ast_ty::uint_expr(val as _)
                     };
                     result.push(quote! {
+                        #(#attrs)*
                         pub const #canonical_ident : #ty = #val ;
                     });
                 }
@@ -660,12 +667,14 @@ impl CodeGenerator for Var {
                         Ok(string) => {
                             let cstr = helpers::ast_ty::cstr_expr(string);
                             result.push(quote! {
+                                #(#attrs)*
                                 pub const #canonical_ident : &'static #ty = #cstr ;
                             });
                         }
                         Err(..) => {
                             let bytes = helpers::ast_ty::byte_array_expr(bytes);
                             result.push(quote! {
+                                #(#attrs)*
                                 pub const #canonical_ident : #ty = #bytes ;
                             });
                         }
@@ -674,20 +683,20 @@ impl CodeGenerator for Var {
                 VarType::Float(f) => {
                     match helpers::ast_ty::float_expr(ctx, f) {
                         Ok(expr) => result.push(quote! {
+                            #(#attrs)*
                             pub const #canonical_ident : #ty = #expr ;
                         }),
                         Err(..) => return,
                     }
                 }
                 VarType::Char(c) => {
                     result.push(quote! {
+                        #(#attrs)*
                         pub const #canonical_ident : #ty = #c ;
                     });
                 }
             }
         } else {
-            let mut attrs = vec![];
-
             // If necessary, apply a `#[link_name]` attribute
             let link_name = self.mangled_name().unwrap_or(self.name());
             if !utils::names_will_be_identical_after_mangling(

tests/expectations/tests/issue-1995.rs

@@ -0,0 +1,37 @@
+#![allow(
+    dead_code,
+    non_snake_case,
+    non_camel_case_types,
+    non_upper_case_globals
+)]
+
+/// This is a constant that has a docstring
+///
+/// And expected to be found in generated bindings code too.
+pub const FOO: ::std::os::raw::c_int = 1;
+/// This is a constant that has a docstring
+///
+/// And expected to be found in generated bindings code too.
+#[repr(C)]
+#[derive(Debug, Default, Copy, Clone)]
+pub struct Bar {
+    pub baz: ::std::os::raw::c_int,
+}
+#[test]
+fn bindgen_test_layout_Bar() {
+    assert_eq!(
+        ::std::mem::size_of::<Bar>(),
+        4usize,
+        concat!("Size of: ", stringify!(Bar))
+    );
+    assert_eq!(
+        ::std::mem::align_of::<Bar>(),
+        4usize,
+        concat!("Alignment of ", stringify!(Bar))
+    );
+    assert_eq!(
+        unsafe { &(*(::std::ptr::null::<Bar>())).baz as *const _ as usize },
+        0usize,
+        concat!("Offset of field: ", stringify!(Bar), "::", stringify!(baz))
+    );
+}

tests/headers/issue-1995.h

@@ -0,0 +1,12 @@
+/// This is a constant that has a docstring
+///
+/// And expected to be found in generated bindings code too.
+const int FOO = 1;
+
+/// This is a constant that has a docstring
+///
+/// And expected to be found in generated bindings code too.
+struct Bar
+{
+    int baz;
+};