]> git.lizzy.rs Git - rust.git/blobdiff - src/expr.rs
fix: don't force a newline after an empty where clause
[rust.git] / src / expr.rs
index 2a1d40c956464fbb73f37d4753aa466c5dc2baf0..1ba879ccc1d315d1180bb1e8af612bf05574f36c 100644 (file)
@@ -2,15 +2,15 @@
 use std::cmp::min;
 
 use itertools::Itertools;
-use syntax::parse::token::DelimToken;
-use syntax::source_map::{BytePos, SourceMap, Span};
-use syntax::{ast, ptr};
+use rustc_ast::token::{DelimToken, LitKind};
+use rustc_ast::{ast, ptr};
+use rustc_span::{BytePos, Span};
 
 use crate::chains::rewrite_chain;
 use crate::closures;
 use crate::comment::{
-    combine_strs_with_missing_comments, contains_comment, recover_comment_removed, rewrite_comment,
-    rewrite_missing_comment, CharClasses, FindUncommented,
+    combine_strs_with_missing_comments, comment_style, contains_comment, recover_comment_removed,
+    rewrite_comment, rewrite_missing_comment, CharClasses, FindUncommented,
 };
 use crate::config::lists::*;
 use crate::config::{Config, ControlBraceStyle, IndentStyle, Version};
@@ -65,7 +65,7 @@ pub(crate) fn format_expr(
         shape
     };
 
-    let expr_rw = match expr.node {
+    let expr_rw = match expr.kind {
         ast::ExprKind::Array(ref expr_vec) => rewrite_array(
             "",
             expr_vec.iter(),
@@ -75,7 +75,17 @@ pub(crate) fn format_expr(
             choose_separator_tactic(context, expr.span),
             None,
         ),
-        ast::ExprKind::Lit(ref l) => rewrite_literal(context, l, shape),
+        ast::ExprKind::Lit(ref l) => {
+            if let Some(expr_rw) = rewrite_literal(context, l, shape) {
+                Some(expr_rw)
+            } else {
+                if let LitKind::StrRaw(_) = l.token.kind {
+                    Some(context.snippet(l.span).trim().into())
+                } else {
+                    None
+                }
+            }
+        }
         ast::ExprKind::Call(ref callee, ref args) => {
             let inner_span = mk_sp(callee.span.hi(), expr.span.hi());
             let callee_str = callee.rewrite(context, shape)?;
@@ -114,6 +124,9 @@ pub(crate) fn format_expr(
         | ast::ExprKind::Loop(..)
         | ast::ExprKind::While(..) => to_control_flow(expr, expr_type)
             .and_then(|control_flow| control_flow.rewrite(context, shape)),
+        ast::ExprKind::ConstBlock(ref anon_const) => {
+            Some(format!("const {}", anon_const.rewrite(context, shape)?))
+        }
         ast::ExprKind::Block(ref block, opt_label) => {
             match expr_type {
                 ExprType::Statement => {
@@ -149,7 +162,7 @@ pub(crate) fn format_expr(
         ast::ExprKind::Path(ref qself, ref path) => {
             rewrite_path(context, PathContext::Expr, qself.as_ref(), path, shape)
         }
-        ast::ExprKind::Assign(ref lhs, ref rhs) => {
+        ast::ExprKind::Assign(ref lhs, ref rhs, _) => {
             rewrite_assignment(context, lhs, rhs, None, shape)
         }
         ast::ExprKind::AssignOp(ref op, ref lhs, ref rhs) => {
@@ -189,7 +202,7 @@ pub(crate) fn format_expr(
         ast::ExprKind::Try(..) | ast::ExprKind::Field(..) | ast::ExprKind::MethodCall(..) => {
             rewrite_chain(expr, context, shape)
         }
-        ast::ExprKind::Mac(ref mac) => {
+        ast::ExprKind::MacCall(ref mac) => {
             rewrite_macro(mac, None, context, shape, MacroPosition::Expression).or_else(|| {
                 wrap_str(
                     context.snippet(expr.span).to_owned(),
@@ -203,8 +216,8 @@ pub(crate) fn format_expr(
             rewrite_unary_prefix(context, "return ", &**expr, shape)
         }
         ast::ExprKind::Box(ref expr) => rewrite_unary_prefix(context, "box ", &**expr, shape),
-        ast::ExprKind::AddrOf(mutability, ref expr) => {
-            rewrite_expr_addrof(context, mutability, expr, shape)
+        ast::ExprKind::AddrOf(borrow_kind, mutability, ref expr) => {
+            rewrite_expr_addrof(context, borrow_kind, mutability, expr, shape)
         }
         ast::ExprKind::Cast(ref expr, ref ty) => rewrite_pair(
             &**expr,
@@ -240,19 +253,20 @@ pub(crate) fn format_expr(
             };
 
             fn needs_space_before_range(context: &RewriteContext<'_>, lhs: &ast::Expr) -> bool {
-                match lhs.node {
-                    ast::ExprKind::Lit(ref lit) => match lit.node {
-                        ast::LitKind::FloatUnsuffixed(..) => {
+                match lhs.kind {
+                    ast::ExprKind::Lit(ref lit) => match lit.kind {
+                        ast::LitKind::Float(_, ast::LitFloatType::Unsuffixed) => {
                             context.snippet(lit.span).ends_with('.')
                         }
                         _ => false,
                     },
+                    ast::ExprKind::Unary(_, ref expr) => needs_space_before_range(context, &expr),
                     _ => false,
                 }
             }
 
             fn needs_space_after_range(rhs: &ast::Expr) -> bool {
-                match rhs.node {
+                match rhs.kind {
                     // Don't format `.. ..` into `....`, which is invalid.
                     //
                     // This check is unnecessary for `lhs`, because a range
@@ -311,7 +325,11 @@ fn needs_space_after_range(rhs: &ast::Expr) -> bool {
         }
         // We do not format these expressions yet, but they should still
         // satisfy our width restrictions.
-        ast::ExprKind::InlineAsm(..) => Some(context.snippet(expr.span).to_owned()),
+        // Style Guide RFC for InlineAsm variant pending
+        // https://github.com/rust-dev-tools/fmt-rfcs/issues/152
+        ast::ExprKind::LlvmInlineAsm(..) | ast::ExprKind::InlineAsm(..) => {
+            Some(context.snippet(expr.span).to_owned())
+        }
         ast::ExprKind::TryBlock(ref block) => {
             if let rw @ Some(_) =
                 rewrite_single_line_block(context, "try ", block, Some(&expr.attrs), None, shape)
@@ -419,7 +437,7 @@ fn rewrite_empty_block(
         return None;
     }
 
-    if !block_contains_comment(block, context.source_map) && shape.width >= 2 {
+    if !block_contains_comment(context, block) && shape.width >= 2 {
         return Some(format!("{}{}{{}}", prefix, label_str));
     }
 
@@ -476,7 +494,7 @@ fn rewrite_single_line_block(
     label: Option<ast::Label>,
     shape: Shape,
 ) -> Option<String> {
-    if is_simple_block(block, attrs, context.source_map) {
+    if is_simple_block(context, block, attrs) {
         let expr_shape = shape.offset_left(last_line_width(prefix))?;
         let expr_str = block.stmts[0].rewrite(context, expr_shape)?;
         let label_str = rewrite_label(label);
@@ -565,7 +583,7 @@ pub(crate) fn rewrite_cond(
     expr: &ast::Expr,
     shape: Shape,
 ) -> Option<String> {
-    match expr.node {
+    match expr.kind {
         ast::ExprKind::Match(ref cond, _) => {
             // `match `cond` {`
             let cond_shape = match context.config.indent_style() {
@@ -602,7 +620,7 @@ struct ControlFlow<'a> {
 }
 
 fn extract_pats_and_cond(expr: &ast::Expr) -> (Option<&ast::Pat>, &ast::Expr) {
-    match expr.node {
+    match expr.kind {
         ast::ExprKind::Let(ref pat, ref cond) => (Some(pat), cond),
         _ => (None, expr),
     }
@@ -610,7 +628,7 @@ fn extract_pats_and_cond(expr: &ast::Expr) -> (Option<&ast::Pat>, &ast::Expr) {
 
 // FIXME: Refactor this.
 fn to_control_flow(expr: &ast::Expr, expr_type: ExprType) -> Option<ControlFlow<'_>> {
-    match expr.node {
+    match expr.kind {
         ast::ExprKind::If(ref cond, ref if_block, ref else_block) => {
             let (pat, cond) = extract_pats_and_cond(cond);
             Some(ControlFlow::new_if(
@@ -738,9 +756,9 @@ fn rewrite_single_line(
         let else_block = self.else_block?;
         let fixed_cost = self.keyword.len() + "  {  } else {  }".len();
 
-        if let ast::ExprKind::Block(ref else_node, _) = else_block.node {
-            if !is_simple_block(self.block, None, context.source_map)
-                || !is_simple_block(else_node, None, context.source_map)
+        if let ast::ExprKind::Block(ref else_node, _) = else_block.kind {
+            if !is_simple_block(context, self.block, None)
+                || !is_simple_block(context, else_node, None)
                 || pat_expr_str.contains('\n')
             {
                 return None;
@@ -797,7 +815,7 @@ fn rewrite_pat_expr(
         debug!("rewrite_pat_expr {:?} {:?} {:?}", shape, self.pat, expr);
 
         let cond_shape = shape.offset_left(offset)?;
-        if !self.pat.is_none() {
+        if let Some(pat) = self.pat {
             let matcher = if self.matcher.is_empty() {
                 self.matcher.to_owned()
             } else {
@@ -806,12 +824,41 @@ fn rewrite_pat_expr(
             let pat_shape = cond_shape
                 .offset_left(matcher.len())?
                 .sub_width(self.connector.len())?;
-            let pat_string = if let Some(pat) = self.pat {
-                pat.rewrite(context, pat_shape)?
+            let pat_string = pat.rewrite(context, pat_shape)?;
+            let comments_lo = context
+                .snippet_provider
+                .span_after(self.span, self.connector.trim());
+            let missing_comments = if let Some(comment) =
+                rewrite_missing_comment(mk_sp(comments_lo, expr.span.lo()), cond_shape, context)
+            {
+                if !self.connector.is_empty() && !comment.is_empty() {
+                    if comment_style(&comment, false).is_line_comment() || comment.contains("\n") {
+                        let newline = &pat_shape
+                            .indent
+                            .block_indent(context.config)
+                            .to_string_with_newline(context.config);
+                        // An extra space is added when the lhs and rhs are joined
+                        // so we need to remove one space from the end to ensure
+                        // the comment and rhs are aligned.
+                        let mut suffix = newline.as_ref().to_string();
+                        if !suffix.is_empty() {
+                            suffix.truncate(suffix.len() - 1);
+                        }
+                        format!("{}{}{}", newline, comment, suffix)
+                    } else {
+                        format!(" {}", comment)
+                    }
+                } else {
+                    comment
+                }
             } else {
                 "".to_owned()
             };
-            let result = format!("{}{}{}", matcher, pat_string, self.connector);
+
+            let result = format!(
+                "{}{}{}{}",
+                matcher, pat_string, self.connector, missing_comments
+            );
             return rewrite_assign_rhs(context, result, expr, cond_shape);
         }
 
@@ -1004,7 +1051,7 @@ fn rewrite(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<String>
         if let Some(else_block) = self.else_block {
             let shape = Shape::indented(shape.indent, context.config);
             let mut last_in_chain = false;
-            let rewrite = match else_block.node {
+            let rewrite = match else_block.kind {
                 // If the else expression is another if-else expression, prevent it
                 // from being formatted on a single line.
                 // Note how we're passing the original shape, as the
@@ -1094,9 +1141,8 @@ fn extract_comment(span: Span, context: &RewriteContext<'_>, shape: Shape) -> Op
     }
 }
 
-pub(crate) fn block_contains_comment(block: &ast::Block, source_map: &SourceMap) -> bool {
-    let snippet = source_map.span_to_snippet(block.span).unwrap();
-    contains_comment(&snippet)
+pub(crate) fn block_contains_comment(context: &RewriteContext<'_>, block: &ast::Block) -> bool {
+    contains_comment(context.snippet(block.span))
 }
 
 // Checks that a block contains no statements, an expression and no comments or
@@ -1104,42 +1150,42 @@ pub(crate) fn block_contains_comment(block: &ast::Block, source_map: &SourceMap)
 // FIXME: incorrectly returns false when comment is contained completely within
 // the expression.
 pub(crate) fn is_simple_block(
+    context: &RewriteContext<'_>,
     block: &ast::Block,
     attrs: Option<&[ast::Attribute]>,
-    source_map: &SourceMap,
 ) -> bool {
-    (block.stmts.len() == 1
+    block.stmts.len() == 1
         && stmt_is_expr(&block.stmts[0])
-        && !block_contains_comment(block, source_map)
-        && attrs.map_or(true, |a| a.is_empty()))
+        && !block_contains_comment(context, block)
+        && attrs.map_or(true, |a| a.is_empty())
 }
 
 /// Checks whether a block contains at most one statement or expression, and no
 /// comments or attributes.
 pub(crate) fn is_simple_block_stmt(
+    context: &RewriteContext<'_>,
     block: &ast::Block,
     attrs: Option<&[ast::Attribute]>,
-    source_map: &SourceMap,
 ) -> bool {
     block.stmts.len() <= 1
-        && !block_contains_comment(block, source_map)
+        && !block_contains_comment(context, block)
         && attrs.map_or(true, |a| a.is_empty())
 }
 
 /// Checks whether a block contains no statements, expressions, comments, or
 /// inner attributes.
 pub(crate) fn is_empty_block(
+    context: &RewriteContext<'_>,
     block: &ast::Block,
     attrs: Option<&[ast::Attribute]>,
-    source_map: &SourceMap,
 ) -> bool {
     block.stmts.is_empty()
-        && !block_contains_comment(block, source_map)
+        && !block_contains_comment(context, block)
         && attrs.map_or(true, |a| inner_attributes(a).is_empty())
 }
 
 pub(crate) fn stmt_is_expr(stmt: &ast::Stmt) -> bool {
-    match stmt.node {
+    match stmt.kind {
         ast::StmtKind::Expr(..) => true,
         _ => false,
     }
@@ -1158,7 +1204,7 @@ pub(crate) fn rewrite_literal(
     l: &ast::Lit,
     shape: Shape,
 ) -> Option<String> {
-    match l.node {
+    match l.kind {
         ast::LitKind::Str(_, ast::StrStyle::Cooked) => rewrite_string_lit(context, l.span, shape),
         _ => wrap_str(
             context.snippet(l.span).to_owned(),
@@ -1176,27 +1222,9 @@ fn rewrite_string_lit(context: &RewriteContext<'_>, span: Span, shape: Shape) ->
             .lines()
             .dropping_back(1)
             .all(|line| line.ends_with('\\'))
+            && context.config.version() == Version::Two
         {
-            let new_indent = shape.visual_indent(1).indent;
-            let indented_string_lit = String::from(
-                string_lit
-                    .lines()
-                    .map(|line| {
-                        format!(
-                            "{}{}",
-                            new_indent.to_string(context.config),
-                            line.trim_start()
-                        )
-                    })
-                    .collect::<Vec<_>>()
-                    .join("\n")
-                    .trim_start(),
-            );
-            return if context.config.version() == Version::Two {
-                Some(indented_string_lit)
-            } else {
-                wrap_str(indented_string_lit, context.config.max_width(), shape)
-            };
+            return Some(string_lit.to_owned());
         } else {
             return wrap_str(string_lit.to_owned(), context.config.max_width(), shape);
         }
@@ -1243,10 +1271,10 @@ pub(crate) fn rewrite_call(
 }
 
 pub(crate) fn is_simple_expr(expr: &ast::Expr) -> bool {
-    match expr.node {
+    match expr.kind {
         ast::ExprKind::Lit(..) => true,
         ast::ExprKind::Path(ref qself, ref path) => qself.is_none() && path.segments.len() <= 1,
-        ast::ExprKind::AddrOf(_, ref expr)
+        ast::ExprKind::AddrOf(_, _, ref expr)
         | ast::ExprKind::Box(ref expr)
         | ast::ExprKind::Cast(ref expr, _)
         | ast::ExprKind::Field(ref expr, _)
@@ -1269,7 +1297,7 @@ pub(crate) fn can_be_overflowed_expr(
     expr: &ast::Expr,
     args_len: usize,
 ) -> bool {
-    match expr.node {
+    match expr.kind {
         _ if !expr.attrs.is_empty() => false,
         ast::ExprKind::Match(..) => {
             (context.use_block_indent() && args_len == 1)
@@ -1291,9 +1319,13 @@ pub(crate) fn can_be_overflowed_expr(
             context.config.overflow_delimited_expr()
                 || (context.use_block_indent() && args_len == 1)
         }
-        ast::ExprKind::Mac(ref mac) => {
-            match (mac.delim, context.config.overflow_delimited_expr()) {
-                (ast::MacDelimiter::Bracket, true) | (ast::MacDelimiter::Brace, true) => true,
+        ast::ExprKind::MacCall(ref mac) => {
+            match (
+                rustc_ast::ast::MacDelimiter::from_token(mac.args.delim()),
+                context.config.overflow_delimited_expr(),
+            ) {
+                (Some(ast::MacDelimiter::Bracket), true)
+                | (Some(ast::MacDelimiter::Brace), true) => true,
                 _ => context.use_block_indent() && args_len == 1,
             }
         }
@@ -1304,7 +1336,7 @@ pub(crate) fn can_be_overflowed_expr(
         }
 
         // Handle unary-like expressions
-        ast::ExprKind::AddrOf(_, ref expr)
+        ast::ExprKind::AddrOf(_, _, ref expr)
         | ast::ExprKind::Box(ref expr)
         | ast::ExprKind::Try(ref expr)
         | ast::ExprKind::Unary(_, ref expr)
@@ -1314,9 +1346,9 @@ pub(crate) fn can_be_overflowed_expr(
 }
 
 pub(crate) fn is_nested_call(expr: &ast::Expr) -> bool {
-    match expr.node {
-        ast::ExprKind::Call(..) | ast::ExprKind::Mac(..) => true,
-        ast::ExprKind::AddrOf(_, ref expr)
+    match expr.kind {
+        ast::ExprKind::Call(..) | ast::ExprKind::MacCall(..) => true,
+        ast::ExprKind::AddrOf(_, _, ref expr)
         | ast::ExprKind::Box(ref expr)
         | ast::ExprKind::Try(ref expr)
         | ast::ExprKind::Unary(_, ref expr)
@@ -1370,7 +1402,7 @@ fn rewrite_paren(
         post_comment = rewrite_missing_comment(post_span, shape, context)?;
 
         // Remove nested parens if there are no comments.
-        if let ast::ExprKind::Paren(ref subsubexpr) = subexpr.node {
+        if let ast::ExprKind::Paren(ref subsubexpr) = subexpr.kind {
             if remove_nested_parens && pre_comment.is_empty() && post_comment.is_empty() {
                 span = subexpr.span;
                 subexpr = subsubexpr;
@@ -1963,21 +1995,24 @@ pub(crate) fn prefer_next_line(
 
 fn rewrite_expr_addrof(
     context: &RewriteContext<'_>,
+    borrow_kind: ast::BorrowKind,
     mutability: ast::Mutability,
     expr: &ast::Expr,
     shape: Shape,
 ) -> Option<String> {
-    let operator_str = match mutability {
-        ast::Mutability::Immutable => "&",
-        ast::Mutability::Mutable => "&mut ",
+    let operator_str = match (mutability, borrow_kind) {
+        (ast::Mutability::Not, ast::BorrowKind::Ref) => "&",
+        (ast::Mutability::Not, ast::BorrowKind::Raw) => "&raw const ",
+        (ast::Mutability::Mut, ast::BorrowKind::Ref) => "&mut ",
+        (ast::Mutability::Mut, ast::BorrowKind::Raw) => "&raw mut ",
     };
     rewrite_unary_prefix(context, operator_str, expr, shape)
 }
 
 pub(crate) fn is_method_call(expr: &ast::Expr) -> bool {
-    match expr.node {
+    match expr.kind {
         ast::ExprKind::MethodCall(..) => true,
-        ast::ExprKind::AddrOf(_, ref expr)
+        ast::ExprKind::AddrOf(_, _, ref expr)
         | ast::ExprKind::Box(ref expr)
         | ast::ExprKind::Cast(ref expr, _)
         | ast::ExprKind::Try(ref expr)