1 files changed, 37 insertions, 53 deletions

diff --git a/crates/hir_expand/src/builtin_macro.rs b/crates/hir_expand/src/builtin_macro.rs
index 80b60d59f..eb57ea7d6 100644
--- a/crates/hir_expand/src/builtin_macro.rs
+++ b/crates/hir_expand/src/builtin_macro.rs
@@ -6,7 +6,7 @@ use crate::{
 
 use base_db::{AnchoredPath, FileId};
 use either::Either;
-use mbe::{parse_to_token_tree, ExpandResult};
+use mbe::{parse_exprs_with_sep, parse_to_token_tree, ExpandResult};
 use parser::FragmentKind;
 use syntax::ast::{self, AstToken};
 
@@ -182,25 +182,10 @@ fn assert_expand(
     // ```,
     // which is wrong but useful.
 
-    let mut args = Vec::new();
-    let mut current = Vec::new();
-    for tt in tt.token_trees.iter().cloned() {
-        match tt {
-            tt::TokenTree::Leaf(tt::Leaf::Punct(p)) if p.char == ',' => {
-                args.push(current);
-                current = Vec::new();
-            }
-            _ => {
-                current.push(tt);
-            }
-        }
-    }
-    if !current.is_empty() {
-        args.push(current);
-    }
+    let args = parse_exprs_with_sep(tt, ',');
 
     let arg_tts = args.into_iter().flat_map(|arg| {
-        quote! { &(##arg), }
+        quote! { &(#arg), }
     }.token_trees).collect::<Vec<_>>();
 
     let expanded = quote! {
@@ -238,35 +223,21 @@ fn format_args_expand(
     // ])
     // ```,
     // which is still not really correct, but close enough for now
-    let mut args = Vec::new();
-    let mut current = Vec::new();
-    for tt in tt.token_trees.iter().cloned() {
-        match tt {
-            tt::TokenTree::Leaf(tt::Leaf::Punct(p)) if p.char == ',' => {
-                args.push(current);
-                current = Vec::new();
-            }
-            _ => {
-                current.push(tt);
-            }
-        }
-    }
-    if !current.is_empty() {
-        args.push(current);
-    }
+    let mut args = parse_exprs_with_sep(tt, ',');
+
     if args.is_empty() {
         return ExpandResult::only_err(mbe::ExpandError::NoMatchingRule);
     }
     for arg in &mut args {
         // Remove `key =`.
-        if matches!(arg.get(1), Some(tt::TokenTree::Leaf(tt::Leaf::Punct(p))) if p.char == '=' && p.spacing != tt::Spacing::Joint)
+        if matches!(arg.token_trees.get(1), Some(tt::TokenTree::Leaf(tt::Leaf::Punct(p))) if p.char == '=' && p.spacing != tt::Spacing::Joint)
         {
-            arg.drain(..2);
+            arg.token_trees.drain(..2);
         }
     }
     let _format_string = args.remove(0);
     let arg_tts = args.into_iter().flat_map(|arg| {
-        quote! { std::fmt::ArgumentV1::new(&(##arg), std::fmt::Display::fmt), }
+        quote! { std::fmt::ArgumentV1::new(&(#arg), std::fmt::Display::fmt), }
     }.token_trees).collect::<Vec<_>>();
     let expanded = quote! {
         std::fmt::Arguments::new_v1(&[], &[##arg_tts])
@@ -327,17 +298,14 @@ fn concat_expand(
                 // concat works with string and char literals, so remove any quotes.
                 // It also works with integer, float and boolean literals, so just use the rest
                 // as-is.
-
-                text += it
-                    .text
-                    .trim_start_matches(|c| match c {
-                        'r' | '#' | '\'' | '"' => true,
-                        _ => false,
-                    })
-                    .trim_end_matches(|c| match c {
-                        '#' | '\'' | '"' => true,
-                        _ => false,
-                    });
+                let component = unquote_str(&it).unwrap_or_else(|| it.text.to_string());
+                text.push_str(&component);
+            }
+            // handle boolean literals
+            tt::TokenTree::Leaf(tt::Leaf::Ident(id))
+                if i % 2 == 0 && (id.text == "true" || id.text == "false") =>
+            {
+                text.push_str(id.text.as_str());
             }
             tt::TokenTree::Leaf(tt::Leaf::Punct(punct)) if i % 2 == 1 && punct.char == ',' => (),
             _ => {
@@ -345,7 +313,6 @@ fn concat_expand(
             }
         }
     }
-
     ExpandResult { value: Some((quote!(#text), FragmentKind::Expr)), err }
 }
 
@@ -724,6 +691,25 @@ mod tests {
     }
 
     #[test]
+    fn test_format_args_expand_with_comma_exprs() {
+        let expanded = expand_builtin_macro(
+            r#"
+            #[rustc_builtin_macro]
+            macro_rules! format_args {
+                ($fmt:expr) => ({ /* compiler built-in */ });
+                ($fmt:expr, $($args:tt)*) => ({ /* compiler built-in */ })
+            }
+            format_args!("{} {:?}", a::<A,B>(), b);
+            "#,
+        );
+
+        assert_eq!(
+            expanded,
+            r#"std::fmt::Arguments::new_v1(&[], &[std::fmt::ArgumentV1::new(&(a::<A,B>()),std::fmt::Display::fmt),std::fmt::ArgumentV1::new(&(b),std::fmt::Display::fmt),])"#
+        );
+    }
+
+    #[test]
     fn test_include_bytes_expand() {
         let expanded = expand_builtin_macro(
             r#"
@@ -745,12 +731,10 @@ mod tests {
             r##"
             #[rustc_builtin_macro]
             macro_rules! concat {}
-            concat!("foo", 0, r#"bar"#);
+            concat!("foo", "r", 0, r#"bar"#, false);
             "##,
         );
 
-        assert_eq!(expanded, r#""foo0bar""#);
-
-        // FIXME: `true`/`false` literals don't work.
+        assert_eq!(expanded, r#""foor0barfalse""#);
     }
 }