-// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-use config::lists::*;
-use syntax::parse::classify;
-use syntax::source_map::Span;
-use syntax::{ast, ptr};
-
-use expr::{block_contains_comment, is_simple_block, is_unsafe_block, rewrite_cond};
-use items::{span_hi_for_arg, span_lo_for_arg};
-use lists::{definitive_tactic, itemize_list, write_list, ListFormatting, Separator};
-use overflow::OverflowableItem;
-use rewrite::{Rewrite, RewriteContext};
-use shape::Shape;
-use source_map::SpanUtils;
-use utils::{last_line_width, left_most_sub_expr, stmt_expr};
+use rustc_ast::{ast, ptr};
+use rustc_span::Span;
+
+use crate::attr::get_attrs_from_stmt;
+use crate::config::lists::*;
+use crate::config::Version;
+use crate::expr::{block_contains_comment, is_simple_block, is_unsafe_block, rewrite_cond};
+use crate::items::{span_hi_for_param, span_lo_for_param};
+use crate::lists::{definitive_tactic, itemize_list, write_list, ListFormatting, Separator};
+use crate::overflow::OverflowableItem;
+use crate::rewrite::{Rewrite, RewriteContext};
+use crate::shape::Shape;
+use crate::source_map::SpanUtils;
+use crate::utils::{last_line_width, left_most_sub_expr, stmt_expr, NodeIdExt};
// This module is pretty messy because of the rules around closures and blocks:
// FIXME - the below is probably no longer true in full.
// statement without needing a semi-colon), then adding or removing braces
// can change whether it is treated as an expression or statement.
-pub fn rewrite_closure(
+pub(crate) fn rewrite_closure(
capture: ast::CaptureBy,
- asyncness: ast::IsAsync,
+ is_async: &ast::Async,
movability: ast::Movability,
fn_decl: &ast::FnDecl,
body: &ast::Expr,
span: Span,
- context: &RewriteContext,
+ context: &RewriteContext<'_>,
shape: Shape,
) -> Option<String> {
debug!("rewrite_closure {:?}", body);
let (prefix, extra_offset) = rewrite_closure_fn_decl(
- capture, asyncness, movability, fn_decl, body, span, context, shape,
+ capture, is_async, movability, fn_decl, body, span, context, shape,
)?;
// 1 = space between `|...|` and body.
let body_shape = shape.offset_left(extra_offset)?;
- if let ast::ExprKind::Block(ref block, _) = body.node {
+ if let ast::ExprKind::Block(ref block, _) = body.kind {
// The body of the closure is an empty block.
- if block.stmts.is_empty() && !block_contains_comment(block, context.source_map) {
+ if block.stmts.is_empty() && !block_contains_comment(context, block) {
return body
.rewrite(context, shape)
.map(|s| format!("{} {}", prefix, s));
}
let result = match fn_decl.output {
- ast::FunctionRetTy::Default(_) => {
+ ast::FnRetTy::Default(_) if !context.inside_macro() => {
try_rewrite_without_block(body, &prefix, context, shape, body_shape)
}
_ => None,
fn try_rewrite_without_block(
expr: &ast::Expr,
prefix: &str,
- context: &RewriteContext,
+ context: &RewriteContext<'_>,
shape: Shape,
body_shape: Shape,
) -> Option<String> {
fn get_inner_expr<'a>(
expr: &'a ast::Expr,
prefix: &str,
- context: &RewriteContext,
+ context: &RewriteContext<'_>,
) -> &'a ast::Expr {
- if let ast::ExprKind::Block(ref block, _) = expr.node {
+ if let ast::ExprKind::Block(ref block, _) = expr.kind {
if !needs_block(block, prefix, context) {
- // block.stmts.len() == 1
- if let Some(expr) = stmt_expr(&block.stmts[0]) {
+ // block.stmts.len() == 1 except with `|| {{}}`;
+ // https://github.com/rust-lang/rustfmt/issues/3844
+ if let Some(expr) = block.stmts.first().and_then(stmt_expr) {
return get_inner_expr(expr, prefix, context);
}
}
}
// Figure out if a block is necessary.
-fn needs_block(block: &ast::Block, prefix: &str, context: &RewriteContext) -> bool {
+fn needs_block(block: &ast::Block, prefix: &str, context: &RewriteContext<'_>) -> bool {
+ let has_attributes = block.stmts.first().map_or(false, |first_stmt| {
+ !get_attrs_from_stmt(first_stmt).is_empty()
+ });
+
is_unsafe_block(block)
|| block.stmts.len() > 1
- || block_contains_comment(block, context.source_map)
+ || has_attributes
+ || block_contains_comment(context, block)
|| prefix.contains('\n')
}
fn veto_block(e: &ast::Expr) -> bool {
- match e.node {
+ match e.kind {
ast::ExprKind::Call(..)
| ast::ExprKind::Binary(..)
| ast::ExprKind::Cast(..)
}
// Rewrite closure with a single expression wrapping its body with block.
+// || { #[attr] foo() } -> Block { #[attr] foo() }
fn rewrite_closure_with_block(
body: &ast::Expr,
prefix: &str,
- context: &RewriteContext,
+ context: &RewriteContext<'_>,
shape: Shape,
) -> Option<String> {
let left_most = left_most_sub_expr(body);
- let veto_block = veto_block(body) && !classify::expr_requires_semi_to_be_stmt(left_most);
+ let veto_block = veto_block(body) && !expr_requires_semi_to_be_stmt(left_most);
if veto_block {
return None;
}
let block = ast::Block {
stmts: vec![ast::Stmt {
- id: ast::NodeId::new(0),
- node: ast::StmtKind::Expr(ptr::P(body.clone())),
+ id: ast::NodeId::root(),
+ kind: ast::StmtKind::Expr(ptr::P(body.clone())),
span: body.span,
}],
- id: ast::NodeId::new(0),
+ id: ast::NodeId::root(),
rules: ast::BlockCheckMode::Default,
- span: body.span,
- recovered: false,
+ tokens: None,
+ span: body
+ .attrs
+ .first()
+ .map(|attr| attr.span.to(body.span))
+ .unwrap_or(body.span),
+ could_be_bare_literal: false,
};
- let block = ::expr::rewrite_block_with_visitor(context, "", &block, None, None, shape, false)?;
+ let block = crate::expr::rewrite_block_with_visitor(
+ context,
+ "",
+ &block,
+ Some(&body.attrs),
+ None,
+ shape,
+ false,
+ )?;
Some(format!("{} {}", prefix, block))
}
fn rewrite_closure_expr(
expr: &ast::Expr,
prefix: &str,
- context: &RewriteContext,
+ context: &RewriteContext<'_>,
shape: Shape,
) -> Option<String> {
fn allow_multi_line(expr: &ast::Expr) -> bool {
- match expr.node {
+ match expr.kind {
ast::ExprKind::Match(..)
+ | ast::ExprKind::Async(..)
| ast::ExprKind::Block(..)
| ast::ExprKind::TryBlock(..)
| ast::ExprKind::Loop(..)
| ast::ExprKind::Struct(..) => true,
- 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)
fn rewrite_closure_block(
block: &ast::Block,
prefix: &str,
- context: &RewriteContext,
+ context: &RewriteContext<'_>,
shape: Shape,
) -> Option<String> {
Some(format!("{} {}", prefix, block.rewrite(context, shape)?))
// Return type is (prefix, extra_offset)
fn rewrite_closure_fn_decl(
capture: ast::CaptureBy,
- asyncness: ast::IsAsync,
+ asyncness: &ast::Async,
movability: ast::Movability,
fn_decl: &ast::FnDecl,
body: &ast::Expr,
span: Span,
- context: &RewriteContext,
+ context: &RewriteContext<'_>,
shape: Shape,
) -> Option<(String, usize)> {
- let is_async = if asyncness.is_async() { "async " } else { "" };
- let mover = if capture == ast::CaptureBy::Value {
- "move "
+ let immovable = if movability == ast::Movability::Static {
+ "static "
} else {
""
};
- let immovable = if movability == ast::Movability::Static {
- "static "
+ let is_async = if asyncness.is_async() { "async " } else { "" };
+ let mover = if capture == ast::CaptureBy::Value {
+ "move "
} else {
""
};
// 4 = "|| {".len(), which is overconservative when the closure consists of
// a single expression.
let nested_shape = shape
- .shrink_left(is_async.len() + mover.len() + immovable.len())?
+ .shrink_left(immovable.len() + is_async.len() + mover.len())?
.sub_width(4)?;
// 1 = |
- let argument_offset = nested_shape.indent + 1;
- let arg_shape = nested_shape.offset_left(1)?.visual_indent(0);
- let ret_str = fn_decl.output.rewrite(context, arg_shape)?;
+ let param_offset = nested_shape.indent + 1;
+ let param_shape = nested_shape.offset_left(1)?.visual_indent(0);
+ let ret_str = fn_decl.output.rewrite(context, param_shape)?;
- let arg_items = itemize_list(
+ let param_items = itemize_list(
context.snippet_provider,
fn_decl.inputs.iter(),
"|",
",",
- |arg| span_lo_for_arg(arg),
- |arg| span_hi_for_arg(context, arg),
- |arg| arg.rewrite(context, arg_shape),
+ |param| span_lo_for_param(param),
+ |param| span_hi_for_param(context, param),
+ |param| param.rewrite(context, param_shape),
context.snippet_provider.span_after(span, "|"),
body.span.lo(),
false,
);
- let item_vec = arg_items.collect::<Vec<_>>();
- // 1 = space between arguments and return type.
+ let item_vec = param_items.collect::<Vec<_>>();
+ // 1 = space between parameters and return type.
let horizontal_budget = nested_shape.width.saturating_sub(ret_str.len() + 1);
let tactic = definitive_tactic(
&item_vec,
Separator::Comma,
horizontal_budget,
);
- let arg_shape = match tactic {
- DefinitiveListTactic::Horizontal => arg_shape.sub_width(ret_str.len() + 1)?,
- _ => arg_shape,
+ let param_shape = match tactic {
+ DefinitiveListTactic::Horizontal => param_shape.sub_width(ret_str.len() + 1)?,
+ _ => param_shape,
};
- let fmt = ListFormatting::new(arg_shape, context.config)
+ let fmt = ListFormatting::new(param_shape, context.config)
.tactic(tactic)
.preserve_newline(true);
let list_str = write_list(&item_vec, &fmt)?;
- let mut prefix = format!("{}{}{}|{}|", is_async, immovable, mover, list_str);
+ let mut prefix = format!("{}{}{}|{}|", immovable, is_async, mover, list_str);
if !ret_str.is_empty() {
if prefix.contains('\n') {
prefix.push('\n');
- prefix.push_str(&argument_offset.to_string(context.config));
+ prefix.push_str(¶m_offset.to_string(context.config));
} else {
prefix.push(' ');
}
// Rewriting closure which is placed at the end of the function call's arg.
// Returns `None` if the reformatted closure 'looks bad'.
-pub fn rewrite_last_closure(
- context: &RewriteContext,
+pub(crate) fn rewrite_last_closure(
+ context: &RewriteContext<'_>,
expr: &ast::Expr,
shape: Shape,
) -> Option<String> {
- if let ast::ExprKind::Closure(capture, asyncness, movability, ref fn_decl, ref body, _) =
- expr.node
+ if let ast::ExprKind::Closure(capture, ref is_async, movability, ref fn_decl, ref body, _) =
+ expr.kind
{
- let body = match body.node {
+ let body = match body.kind {
ast::ExprKind::Block(ref block, _)
if !is_unsafe_block(block)
- && is_simple_block(block, Some(&body.attrs), context.source_map) =>
+ && !context.inside_macro()
+ && is_simple_block(context, block, Some(&body.attrs)) =>
{
stmt_expr(&block.stmts[0]).unwrap_or(body)
}
_ => body,
};
let (prefix, extra_offset) = rewrite_closure_fn_decl(
- capture, asyncness, movability, fn_decl, body, expr.span, context, shape,
+ capture, is_async, movability, fn_decl, body, expr.span, context, shape,
)?;
// If the closure goes multi line before its body, do not overflow the closure.
if prefix.contains('\n') {
// We force to use block for the body of the closure for certain kinds of expressions.
if is_block_closure_forced(context, body) {
- return rewrite_closure_with_block(body, &prefix, context, body_shape).and_then(
+ return rewrite_closure_with_block(body, &prefix, context, body_shape).map(
|body_str| {
- // If the expression can fit in a single line, we need not force block closure.
- if body_str.lines().count() <= 7 {
- match rewrite_closure_expr(body, &prefix, context, shape) {
- Some(ref single_line_body_str)
- if !single_line_body_str.contains('\n') =>
- {
- Some(single_line_body_str.clone())
+ match fn_decl.output {
+ ast::FnRetTy::Default(..) if body_str.lines().count() <= 7 => {
+ // If the expression can fit in a single line, we need not force block
+ // closure. However, if the closure has a return type, then we must
+ // keep the blocks.
+ match rewrite_closure_expr(body, &prefix, context, shape) {
+ Some(single_line_body_str)
+ if !single_line_body_str.contains('\n') =>
+ {
+ single_line_body_str
+ }
+ _ => body_str,
}
- _ => Some(body_str),
}
- } else {
- Some(body_str)
+ _ => body_str,
}
},
);
// When overflowing the closure which consists of a single control flow expression,
// force to use block if its condition uses multi line.
- let is_multi_lined_cond = rewrite_cond(context, body, body_shape)
- .map(|cond| cond.contains('\n') || cond.len() > body_shape.width)
- .unwrap_or(false);
+ let is_multi_lined_cond = rewrite_cond(context, body, body_shape).map_or(false, |cond| {
+ cond.contains('\n') || cond.len() > body_shape.width
+ });
if is_multi_lined_cond {
return rewrite_closure_with_block(body, &prefix, context, body_shape);
}
None
}
-/// Returns true if the given vector of arguments has more than one `ast::ExprKind::Closure`.
-pub fn args_have_many_closure(args: &[OverflowableItem]) -> bool {
+/// Returns `true` if the given vector of arguments has more than one `ast::ExprKind::Closure`.
+pub(crate) fn args_have_many_closure(args: &[OverflowableItem<'_>]) -> bool {
args.iter()
- .filter(|arg| {
- arg.to_expr()
- .map(|e| match e.node {
- ast::ExprKind::Closure(..) => true,
- _ => false,
- })
- .unwrap_or(false)
- })
+ .filter_map(OverflowableItem::to_expr)
+ .filter(|expr| matches!(expr.kind, ast::ExprKind::Closure(..)))
.count()
> 1
}
-fn is_block_closure_forced(context: &RewriteContext, expr: &ast::Expr) -> bool {
+fn is_block_closure_forced(context: &RewriteContext<'_>, expr: &ast::Expr) -> bool {
// If we are inside macro, we do not want to add or remove block from closure body.
if context.inside_macro() {
false
} else {
- is_block_closure_forced_inner(expr)
+ is_block_closure_forced_inner(expr, context.config.version())
}
}
-fn is_block_closure_forced_inner(expr: &ast::Expr) -> bool {
- match expr.node {
- ast::ExprKind::If(..)
- | ast::ExprKind::IfLet(..)
- | ast::ExprKind::While(..)
- | ast::ExprKind::WhileLet(..)
- | ast::ExprKind::ForLoop(..) => true,
- ast::ExprKind::AddrOf(_, ref expr)
+fn is_block_closure_forced_inner(expr: &ast::Expr, version: Version) -> bool {
+ match expr.kind {
+ ast::ExprKind::If(..) | ast::ExprKind::While(..) | ast::ExprKind::ForLoop(..) => true,
+ ast::ExprKind::Loop(..) if version == Version::Two => true,
+ ast::ExprKind::AddrOf(_, _, ref expr)
| ast::ExprKind::Box(ref expr)
| ast::ExprKind::Try(ref expr)
| ast::ExprKind::Unary(_, ref expr)
- | ast::ExprKind::Cast(ref expr, _) => is_block_closure_forced_inner(expr),
+ | ast::ExprKind::Cast(ref expr, _) => is_block_closure_forced_inner(expr, version),
_ => false,
}
}
+
+/// Does this expression require a semicolon to be treated
+/// as a statement? The negation of this: 'can this expression
+/// be used as a statement without a semicolon' -- is used
+/// as an early-bail-out in the parser so that, for instance,
+/// if true {...} else {...}
+/// |x| 5
+/// isn't parsed as (if true {...} else {...} | x) | 5
+// From https://github.com/rust-lang/rust/blob/master/src/libsyntax/parse/classify.rs.
+fn expr_requires_semi_to_be_stmt(e: &ast::Expr) -> bool {
+ match e.kind {
+ ast::ExprKind::If(..)
+ | ast::ExprKind::Match(..)
+ | ast::ExprKind::Block(..)
+ | ast::ExprKind::While(..)
+ | ast::ExprKind::Loop(..)
+ | ast::ExprKind::ForLoop(..)
+ | ast::ExprKind::TryBlock(..) => false,
+ _ => true,
+ }
+}
projects / rust.git / blobdiff