Remove pretty printer space inside block with only outer attrs

compiler/rustc_ast_pretty/src/pprust/state.rs

@@ -387,23 +387,23 @@ fn print_symbol(&mut self, sym: Symbol, style: ast::StrStyle) {
         self.print_string(sym.as_str(), style);
     }
 
-    fn print_inner_attributes(&mut self, attrs: &[ast::Attribute]) {
+    fn print_inner_attributes(&mut self, attrs: &[ast::Attribute]) -> bool {
         self.print_either_attributes(attrs, ast::AttrStyle::Inner, false, true)
     }
 
-    fn print_inner_attributes_no_trailing_hardbreak(&mut self, attrs: &[ast::Attribute]) {
+    fn print_inner_attributes_no_trailing_hardbreak(&mut self, attrs: &[ast::Attribute]) -> bool {
         self.print_either_attributes(attrs, ast::AttrStyle::Inner, false, false)
     }
 
-    fn print_outer_attributes(&mut self, attrs: &[ast::Attribute]) {
+    fn print_outer_attributes(&mut self, attrs: &[ast::Attribute]) -> bool {
         self.print_either_attributes(attrs, ast::AttrStyle::Outer, false, true)
     }
 
-    fn print_inner_attributes_inline(&mut self, attrs: &[ast::Attribute]) {
+    fn print_inner_attributes_inline(&mut self, attrs: &[ast::Attribute]) -> bool {
         self.print_either_attributes(attrs, ast::AttrStyle::Inner, true, true)
     }
 
-    fn print_outer_attributes_inline(&mut self, attrs: &[ast::Attribute]) {
+    fn print_outer_attributes_inline(&mut self, attrs: &[ast::Attribute]) -> bool {
         self.print_either_attributes(attrs, ast::AttrStyle::Outer, true, true)
     }
 
@@ -413,20 +413,21 @@ fn print_either_attributes(
         kind: ast::AttrStyle,
         is_inline: bool,
         trailing_hardbreak: bool,
-    ) {
+    ) -> bool {
-        let mut count = 0;
+        let mut printed = false;
         for attr in attrs {
             if attr.style == kind {
                 self.print_attribute_inline(attr, is_inline);
                 if is_inline {
                     self.nbsp();
                 }
-                count += 1;
+                printed = true;
             }
         }
-        if count > 0 && trailing_hardbreak && !is_inline {
+        if printed && trailing_hardbreak && !is_inline {
             self.hardbreak_if_not_bol();
         }
+        printed
     }
 
     fn print_attribute(&mut self, attr: &ast::Attribute) {
@@ -1646,7 +1647,7 @@ fn print_poly_trait_ref(&mut self, t: &ast::PolyTraitRef) {
         self.ann.pre(self, AnnNode::Block(blk));
         self.bopen();
 
-        self.print_inner_attributes(attrs);
+        let has_attrs = self.print_inner_attributes(attrs);
 
         for (i, st) in blk.stmts.iter().enumerate() {
             match st.kind {
@@ -1660,7 +1661,7 @@ fn print_poly_trait_ref(&mut self, t: &ast::PolyTraitRef) {
             }
         }
 
-        let empty = attrs.is_empty() && blk.stmts.is_empty();
+        let empty = !has_attrs && blk.stmts.is_empty();
         self.bclose_maybe_open(blk.span, empty, close_box);
         self.ann.post(self, AnnNode::Block(blk))
     }

src/test/pretty/attr-fn-inner.rs

@@ -9,8 +9,8 @@
 fn main() {
     #![rustc_dummy]
     #[rustc_dummy]
-    fn f() { }
+    fn f() {}
 
     #[rustc_dummy]
-    fn g() { }
+    fn g() {}
 }

src/test/pretty/attr-literals.rs

@@ -7,8 +7,8 @@
 fn main() {
     #![rustc_dummy("hi", 1, 2, 1.012, pi = 3.14, bye, name("John"))]
     #[rustc_dummy = 8]
-    fn f() { }
+    fn f() {}
 
     #[rustc_dummy(1, 2, 3)]
-    fn g() { }
+    fn g() {}
 }

src/test/pretty/attr-tokens-raw-ident.rs

@@ -4,4 +4,4 @@
 // pp-exact
 
 #[rustfmt::r#final(final)]
-fn main() { }
+fn main() {}

src/test/pretty/delimited-token-groups.rs

@@ -45,4 +45,4 @@ fn clone() -> S
   }]
 #[rustc_dummy =
   "aaaaaaaa aaaaaaaa aaaaaaaa aaaaaaaa aaaaaaaa aaaaaaaa aaaaaaaa aaaaaaaa aaaaaaaa aaaaaaaa"]
-fn main() { }
+fn main() {}

src/test/pretty/doc-comments.rs

@@ -5,7 +5,7 @@
 // some single-line non-doc comment
 
 /// some single line outer-docs
-fn a() { }
+fn a() {}
 
 fn b() {
     //! some single line inner-docs
@@ -17,7 +17,7 @@ fn b() {
 //////////////////////////////////
 /// some single-line outer-docs preceded by a separator
 /// (and trailing whitespaces)
-fn c() { }
+fn c() {}
 
 /*
  * some multi-line non-doc comment
@@ -26,7 +26,7 @@ fn c() { }
 /**
  * some multi-line outer-docs
  */
-fn d() { }
+fn d() {}
 
 fn e() {
     /*!
@@ -43,10 +43,10 @@ fn e() {
 /**
  * some multi-line outer-docs preceded by a separator
  */
-fn f() { }
+fn f() {}
 
 #[doc = "unsugared outer doc-comments work also"]
-fn g() { }
+fn g() {}
 
 fn h() {
     #![doc = "as do inner ones"]

src/test/ui/macros/stringify.rs

@@ -235,7 +235,7 @@ fn test_expr() {
             #[attr]
             {}
         ),
-        "#[attr] { }", // FIXME
+        "#[attr] {}",
     );
     assert_eq!(
         stringify_expr!(