1 files changed, 94 insertions, 0 deletions
diff --git a/macros/src/codegen/locals.rs b/macros/src/codegen/locals.rs
new file mode 100644
index 00000000..96635637
--- /dev/null
+++ b/macros/src/codegen/locals.rs
@@ -0,0 +1,94 @@
+use proc_macro2::TokenStream as TokenStream2;
+use quote::quote;
+use rtfm_syntax::{
+    ast::{App, Local},
+    Context, Map,
+};
+
+use crate::codegen::util;
+
+pub fn codegen(
+    ctxt: Context,
+    locals: &Map<Local>,
+    app: &App,
+) -> (
+    // locals
+    TokenStream2,
+    // pat
+    TokenStream2,
+) {
+    assert!(!locals.is_empty());
+
+    let runs_once = ctxt.runs_once();
+    let ident = util::locals_ident(ctxt, app);
+
+    let mut lt = None;
+    let mut fields = vec![];
+    let mut items = vec![];
+    let mut names = vec![];
+    let mut values = vec![];
+    let mut pats = vec![];
+    let mut has_cfgs = false;
+
+    for (name, local) in locals {
+        let lt = if runs_once {
+            quote!('static)
+        } else {
+            lt = Some(quote!('a));
+            quote!('a)
+        };
+
+        let cfgs = &local.cfgs;
+        has_cfgs |= !cfgs.is_empty();
+
+        let expr = &local.expr;
+        let ty = &local.ty;
+        fields.push(quote!(
+            #(#cfgs)*
+            #name: &#lt mut #ty
+        ));
+        items.push(quote!(
+            #(#cfgs)*
+            static mut #name: #ty = #expr
+        ));
+        values.push(quote!(
+            #(#cfgs)*
+            #name: &mut #name
+        ));
+        names.push(name);
+        pats.push(quote!(
+            #(#cfgs)*
+            #name
+        ));
+    }
+
+    if lt.is_some() && has_cfgs {
+        fields.push(quote!(__marker__: core::marker::PhantomData<&'a mut ()>));
+        values.push(quote!(__marker__: core::marker::PhantomData));
+    }
+
+    let locals = quote!(
+        #[allow(non_snake_case)]
+        #[doc(hidden)]
+        pub struct #ident<#lt> {
+            #(#fields),*
+        }
+
+        impl<#lt> #ident<#lt> {
+            #[inline(always)]
+            unsafe fn new() -> Self {
+                #(#items;)*
+
+                #ident {
+                    #(#values),*
+                }
+            }
+        }
+    );
+
+    let ident = ctxt.ident(app);
+    (
+        locals,
+        quote!(#ident::Locals { #(#pats,)* .. }: #ident::Locals),
+    )
+}