From 5a2943300b9010acf3913c535c983f10af4c9ec7 Mon Sep 17 00:00:00 2001
From: Markus Westerlind <marwes91@gmail.com>
Date: Sat, 5 Oct 2019 21:26:03 +0200
Subject: [PATCH] fix: Expand macros inside macros

---
 vm/src/macros.rs | 36 ++++++++++++++----------------------
 1 file changed, 14 insertions(+), 22 deletions(-)

diff --git a/vm/src/macros.rs b/vm/src/macros.rs
index b0e64f1b8e..b39faf1999 100644
--- a/vm/src/macros.rs
+++ b/vm/src/macros.rs
@@ -9,7 +9,7 @@ use std::{
 use {
     codespan_reporting::Diagnostic,
     downcast_rs::{impl_downcast, Downcast},
-    futures::{stream, Future, Stream},
+    futures::Future,
 };
 
 use crate::base::{
@@ -325,39 +325,31 @@ impl<'a> MacroExpander<'a> {
 
     pub fn run(&mut self, symbols: &mut Symbols, expr: &mut SpannedExpr<Symbol>) {
         {
-            let exprs = {
-                let mut visitor = MacroVisitor {
-                    expander: self,
-                    symbols,
-                    exprs: Vec::new(),
-                };
-                visitor.visit_expr(expr);
-                visitor.exprs
+            let mut visitor = MacroVisitor {
+                expander: self,
+                symbols,
+                exprs: Vec::new(),
             };
-            let _ = stream::futures_ordered(exprs.into_iter().map(move |(expr, future)| {
-                future.then(move |result| -> Result<_, ()> {
-                    match result {
+            let visitor = &mut visitor;
+            visitor.visit_expr(expr);
+
+            while !visitor.exprs.is_empty() {
+                for (expr, future) in mem::replace(&mut visitor.exprs, Vec::new()) {
+                    match future.wait() {
                         Ok(mut replacement) => {
                             replacement.span = expr.span;
                             replace_expr(expr, replacement);
-                            Ok(None)
+                            visitor.visit_expr(expr);
                         }
                         Err(err) => {
                             let expr_span = expr.span;
                             replace_expr(expr, pos::spanned(expr_span, Expr::Error(None)));
 
-                            Ok(Some(pos::spanned(expr.span, err)))
+                            visitor.expander.errors.push(pos::spanned(expr.span, err));
                         }
                     }
-                })
-            }))
-            .for_each(|err| -> Result<(), ()> {
-                if let Some(err) = err {
-                    self.errors.push(err);
                 }
-                Ok(())
-            })
-            .wait();
+            }
         }
         if self.errors.has_errors() {
             info!("Macro errors: {}", self.errors);