Merge pull request rust-lang#3177 from kestred/kstenerson/preserve-brace-leading-ws

Format brace-delimited macros with a space after the name

Author: nrc

src/macros.rs

@@ -256,7 +256,7 @@ pub fn rewrite_macro_inner(
             }
             DelimToken::Paren => Some(format!("{}()", macro_name)),
             DelimToken::Bracket => Some(format!("{}[]", macro_name)),
-            DelimToken::Brace => Some(format!("{}{{}}", macro_name)),
+            DelimToken::Brace => Some(format!("{} {{}}", macro_name)),
             _ => unreachable!(),
         };
     }
@@ -416,8 +416,15 @@ pub fn rewrite_macro_inner(
             }
         }
         DelimToken::Brace => {
-            // Skip macro invocations with braces, for now.
-            trim_left_preserve_layout(context.snippet(mac.span), shape.indent, &context.config)
+            // 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);
+            let macro_raw = snippet.split_at(snippet.find('!')? + 1).1.trim_start();
+            match trim_left_preserve_layout(macro_raw, &shape.indent, &context.config) {
+                Some(macro_body) => Some(format!("{} {}", macro_name, macro_body)),
+                None => Some(format!("{} {}", macro_name, macro_raw)),
+            }
         }
         _ => unreachable!(),
     }

tests/source/macros.rs

@@ -4,7 +4,7 @@ itemmacro!(this, is.now() .formatted(yay));
 
 itemmacro!(really, long.aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaabbb() .is.formatted());
 
-itemmacro!{this, is.bracket().formatted()}
+itemmacro!{this, is.brace().formatted()}
 
 peg_file!   modname  ("mygrammarfile.rustpeg");
 
@@ -106,6 +106,7 @@ fn main() {
 
 impl X {
     empty_invoc!{}
+    empty_invoc! {}
 }
 
 fn issue_1279() {

tests/target/issue-2917/packed_simd.rs

@@ -31,7 +31,7 @@ macro_rules! impl_from_vector {
         }
         */
 
-        test_if!{
+        test_if! {
             $test_tt:
             interpolate_idents! {
                 mod [$id _from_ $source] {

tests/target/lazy_static.rs

@@ -10,7 +10,7 @@ lazy_static! {
 // We need to be able to format `lazy_static!` without known syntax.
 lazy_static!(xxx, yyyy, zzzzz);
 
-lazy_static!{}
+lazy_static! {}
 
 // #2354
 lazy_static! {

tests/target/macros.rs

@@ -9,7 +9,7 @@ itemmacro!(
         .formatted()
 );
 
-itemmacro!{this, is.bracket().formatted()}
+itemmacro! {this, is.brace().formatted()}
 
 peg_file! modname("mygrammarfile.rustpeg");
 
@@ -94,7 +94,7 @@ fn main() {
 
     foo(makro!(1, 3));
 
-    hamkaas!{ () };
+    hamkaas! { () };
 
     macrowithbraces! {dont,    format, me}
 
@@ -104,11 +104,11 @@ fn main() {
 
     some_macro![];
 
-    some_macro!{
+    some_macro! {
         // comment
     };
 
-    some_macro!{
+    some_macro! {
         // comment
     };
 
@@ -131,7 +131,8 @@ fn main() {
 }
 
 impl X {
-    empty_invoc!{}
+    empty_invoc! {}
+    empty_invoc! {}
 }
 
 fn issue_1279() {
@@ -949,7 +950,7 @@ macro_rules! m {
     };
 }
 fn foo() {
-    f!{r#"
+    f! {r#"
             test
        "#};
 }

tests/target/match.rs

@@ -204,19 +204,19 @@ fn issue355() {
             vec![3; 4]
         }
         // Funky bracketing styles
-        t => println!{"a", b},
+        t => println! {"a", b},
         u => vec![1, 2],
         v => vec![3; 4],
         w => println!["a", b],
         x => vec![1, 2],
         y => vec![3; 4],
         // Brackets with comments
-        tc => println!{"a", b}, // comment
-        uc => vec![1, 2],       // comment
-        vc => vec![3; 4],       // comment
-        wc => println!["a", b], // comment
-        xc => vec![1, 2],       // comment
-        yc => vec![3; 4],       // comment
+        tc => println! {"a", b}, // comment
+        uc => vec![1, 2],        // comment
+        vc => vec![3; 4],        // comment
+        wc => println!["a", b],  // comment
+        xc => vec![1, 2],        // comment
+        yc => vec![3; 4],        // comment
         yd => looooooooooooooooooooooooooooooooooooooooooooooooooooooooong_func(
             aaaaaaaaaa, bbbbbbbbbb, cccccccccc, dddddddddd,
         ),