Merge pull request rust-lang#3464 from topecongiro/issue-3463

Avoid duplication on the presence of spaces between macro name and !

Author: topecongiro

src/macros.rs

@@ -431,12 +431,10 @@ pub fn rewrite_macro_inner(
             // For macro invocations with braces, always put a space between
             // the `macro_name!` and `{ /* macro_body */ }` but skip modifying
             // anything in between the braces (for now).
-            let snippet = context.snippet(mac.span);
-            // to remove unnecessary space after macro name
-            let macro_raw = snippet.trim_start_matches(&macro_name).trim_start();
-            match trim_left_preserve_layout(macro_raw, shape.indent, &context.config) {
+            let snippet = context.snippet(mac.span).trim_start_matches(|c| c != '{');
+            match trim_left_preserve_layout(snippet, shape.indent, &context.config) {
                 Some(macro_body) => Some(format!("{} {}", macro_name, macro_body)),
-                None => Some(format!("{} {}", macro_name, macro_raw)),
+                None => Some(format!("{} {}", macro_name, snippet)),
             }
         }
         _ => unreachable!(),

tests/source/macros.rs

@@ -471,3 +471,7 @@ pub fn fold_abi<V: Fold + ?Sized>(_visitor: &mut V, _i: Abi) -> Abi {
         name: (_i.name).map(|it| _visitor.fold_lit_str(it)),
     }
 }
+
+// #3463
+x ! {()}
+x ! y {()}

tests/target/macros.rs

@@ -1048,3 +1048,7 @@ pub fn fold_abi<V: Fold + ?Sized>(_visitor: &mut V, _i: Abi) -> Abi {
         name: (_i.name).map(|it| _visitor.fold_lit_str(it)),
     }
 }
+
+// #3463
+x! {()}
+x! y {()}