Avoid poor-formatting of the rhs of lazy_static macro (#4016)

Author: topecongiro

rustfmt-core/rustfmt-lib/src/expr.rs

@@ -127,9 +127,7 @@ pub(crate) fn format_expr(
         ast::ExprKind::Block(ref block, opt_label) => {
             match expr_type {
                 ExprType::Statement => {
-                    if is_unsafe_block(block) {
-                        rewrite_block(block, Some(&expr.attrs), opt_label, context, shape)
-                    } else if let rw @ Some(_) =
+                    if let rw @ Some(_) =
                         rewrite_empty_block(context, block, Some(&expr.attrs), opt_label, "", shape)
                     {
                         // Rewrite block without trying to put it in a single line.

rustfmt-core/rustfmt-lib/src/macros.rs

@@ -31,8 +31,8 @@ use crate::shape::{Indent, Shape};
 use crate::source_map::SpanUtils;
 use crate::spanned::Spanned;
 use crate::utils::{
-    format_visibility, indent_next_line, is_empty_line, mk_sp, remove_trailing_white_spaces,
-    rewrite_ident, trim_left_preserve_layout, wrap_str, NodeIdExt,
+    count_newlines, format_visibility, indent_next_line, is_empty_line, mk_sp,
+    remove_trailing_white_spaces, rewrite_ident, trim_left_preserve_layout, wrap_str, NodeIdExt,
 };
 use crate::visitor::FmtVisitor;
 
@@ -1473,7 +1473,7 @@ fn format_lazy_static(
         parser.eat(&TokenKind::Colon);
         let ty = parse_or!(parse_ty);
         parser.eat(&TokenKind::Eq);
-        let expr = parse_or!(parse_expr);
+        let expr = parse_or!(parse_stmt)?;
         parser.eat(&TokenKind::Semi);
 
         // Rewrite as a static item.
@@ -1487,11 +1487,15 @@ fn format_lazy_static(
         result.push_str(&crate::expr::rewrite_assign_rhs(
             context,
             stmt,
-            &*expr,
+            &expr,
             nested_shape.sub_width(1)?,
         )?);
         result.push(';');
         if parser.token.kind != TokenKind::Eof {
+            let snippet = context.snippet(mk_sp(parser.prev_span.hi(), parser.token.span.lo()));
+            if count_newlines(snippet) >= 2 {
+                result.push('\n');
+            }
             result.push_str(&nested_shape.indent.to_string_with_newline(context.config));
         }
     }

rustfmt-core/rustfmt-lib/tests/source/lazy_static.rs

@@ -43,3 +43,13 @@ static ref FOO: HashMap<String,
 fn(Foo) -> Result<Box<Bar>, Either<FooError, BarError>>
 ),> = HashMap::new();
 }
+
+lazy_static! {
+    pub static ref BLOCKING_POOL: tokio_threadpool::ThreadPool = {
+        tokio_threadpool::Builder::new().pool_size(1).build()
+    };
+
+    static ref FOO: Foo = unsafe {
+        very_long_function_name().another_function_with_really_long_name()
+    };
+}

rustfmt-core/rustfmt-lib/tests/target/catch.rs

@@ -6,7 +6,9 @@ fn main() {
 
     let x = try /* Invisible comment */ { foo()? };
 
-    let x = try { unsafe { foo()? } };
+    let x = try {
+        unsafe { foo()? }
+    };
 
     let y = match (try { foo()? }) {
         _ => (),

rustfmt-core/rustfmt-lib/tests/target/expr.rs

@@ -152,7 +152,9 @@ fn baz() {
         // Regular unsafe block
     }
 
-    unsafe { foo() }
+    unsafe {
+        foo()
+    }
 
     unsafe {
         foo();

rustfmt-core/rustfmt-lib/tests/target/lazy_static.rs

@@ -47,3 +47,13 @@ lazy_static! {
         ),
     > = HashMap::new();
 }
+
+lazy_static! {
+    pub static ref BLOCKING_POOL: tokio_threadpool::ThreadPool = {
+        tokio_threadpool::Builder::new().pool_size(1).build()
+    };
+
+    static ref FOO: Foo = unsafe {
+        very_long_function_name().another_function_with_really_long_name()
+    };
+}

rustfmt-core/rustfmt-lib/tests/target/match.rs

@@ -243,7 +243,9 @@ fn issue383() {
 
 fn issue507() {
     match 1 {
-        1 => unsafe { std::intrinsics::abort() },
+        1 => unsafe {
+            std::intrinsics::abort()
+        },
         _ => (),
     }
 }