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android / toolchain / rustc / 983137f038c4d4b95a0cd86b7c42d0313b50de67 / . / src / librustc_ast_pretty / pprust.rs
blob: 2d803262f79e1cf2ffeeb523035f1e59ed395942 [file] [log] [blame]
use crate::pp::Breaks::{Consistent, Inconsistent};
use crate::pp::{self, Breaks};
use rustc_ast::ast::{self, BlockCheckMode, PatKind, RangeEnd, RangeSyntax};
use rustc_ast::ast::{Attribute, GenericArg, MacArgs};
use rustc_ast::ast::{GenericBound, SelfKind, TraitBoundModifier};
use rustc_ast::ast::{InlineAsmOperand, InlineAsmRegOrRegClass};
use rustc_ast::ast::{InlineAsmOptions, InlineAsmTemplatePiece};
use rustc_ast::attr;
use rustc_ast::ptr::P;
use rustc_ast::token::{self, BinOpToken, DelimToken, Nonterminal, Token, TokenKind};
use rustc_ast::tokenstream::{TokenStream, TokenTree};
use rustc_ast::util::parser::{self, AssocOp, Fixity};
use rustc_ast::util::{classify, comments};
use rustc_span::edition::Edition;
use rustc_span::source_map::{SourceMap, Spanned};
use rustc_span::symbol::{kw, sym, Ident, IdentPrinter, Symbol};
use rustc_span::{BytePos, FileName, Span};
use std::borrow::Cow;
#[cfg(test)]
mod tests;
pub enum MacHeader<'a> {
Path(&'a ast::Path),
Keyword(&'static str),
}
pub enum AnnNode<'a> {
Ident(&'a Ident),
Name(&'a Symbol),
Block(&'a ast::Block),
Item(&'a ast::Item),
SubItem(ast::NodeId),
Expr(&'a ast::Expr),
Pat(&'a ast::Pat),
Crate(&'a ast::Crate),
}
pub trait PpAnn {
fn pre(&self, _state: &mut State<'_>, _node: AnnNode<'_>) {}
fn post(&self, _state: &mut State<'_>, _node: AnnNode<'_>) {}
}
#[derive(Copy, Clone)]
pub struct NoAnn;
impl PpAnn for NoAnn {}
pub struct Comments<'a> {
sm: &'a SourceMap,
comments: Vec<comments::Comment>,
current: usize,
}
impl<'a> Comments<'a> {
pub fn new(sm: &'a SourceMap, filename: FileName, input: String) -> Comments<'a> {
let comments = comments::gather_comments(sm, filename, input);
Comments { sm, comments, current: 0 }
}
pub fn next(&self) -> Option<comments::Comment> {
self.comments.get(self.current).cloned()
}
pub fn trailing_comment(
&mut self,
span: rustc_span::Span,
next_pos: Option<BytePos>,
) -> Option<comments::Comment> {
if let Some(cmnt) = self.next() {
if cmnt.style != comments::Trailing {
return None;
}
let span_line = self.sm.lookup_char_pos(span.hi());
let comment_line = self.sm.lookup_char_pos(cmnt.pos);
let next = next_pos.unwrap_or_else(|| cmnt.pos + BytePos(1));
if span.hi() < cmnt.pos && cmnt.pos < next && span_line.line == comment_line.line {
return Some(cmnt);
}
}
None
}
}
pub struct State<'a> {
pub s: pp::Printer,
comments: Option<Comments<'a>>,
ann: &'a (dyn PpAnn + 'a),
is_expanded: bool,
}
crate const INDENT_UNIT: usize = 4;
/// Requires you to pass an input filename and reader so that
/// it can scan the input text for comments to copy forward.
pub fn print_crate<'a>(
sm: &'a SourceMap,
krate: &ast::Crate,
filename: FileName,
input: String,
ann: &'a dyn PpAnn,
is_expanded: bool,
edition: Edition,
has_injected_crate: bool,
) -> String {
let mut s = State {
s: pp::mk_printer(),
comments: Some(Comments::new(sm, filename, input)),
ann,
is_expanded,
};
if is_expanded && has_injected_crate {
// We need to print `#![no_std]` (and its feature gate) so that
// compiling pretty-printed source won't inject libstd again.
// However, we don't want these attributes in the AST because
// of the feature gate, so we fake them up here.
// `#![feature(prelude_import)]`
let pi_nested = attr::mk_nested_word_item(Ident::with_dummy_span(sym::prelude_import));
let list = attr::mk_list_item(Ident::with_dummy_span(sym::feature), vec![pi_nested]);
let fake_attr = attr::mk_attr_inner(list);
s.print_attribute(&fake_attr);
// Currently, in Rust 2018 we don't have `extern crate std;` at the crate
// root, so this is not needed, and actually breaks things.
if edition == Edition::Edition2015 {
// `#![no_std]`
let no_std_meta = attr::mk_word_item(Ident::with_dummy_span(sym::no_std));
let fake_attr = attr::mk_attr_inner(no_std_meta);
s.print_attribute(&fake_attr);
}
}
s.print_mod(&krate.module, &krate.attrs);
s.print_remaining_comments();
s.ann.post(&mut s, AnnNode::Crate(krate));
s.s.eof()
}
pub fn to_string(f: impl FnOnce(&mut State<'_>)) -> String {
let mut printer =
State { s: pp::mk_printer(), comments: None, ann: &NoAnn, is_expanded: false };
f(&mut printer);
printer.s.eof()
}
// This makes printed token streams look slightly nicer,
// and also addresses some specific regressions described in #63896 and #73345.
fn tt_prepend_space(tt: &TokenTree, prev: &TokenTree) -> bool {
if let TokenTree::Token(token) = prev {
if let token::DocComment(s) = token.kind {
return !s.as_str().starts_with("//");
}
}
match tt {
TokenTree::Token(token) => match token.kind {
token::Comma => false,
_ => true,
},
TokenTree::Delimited(_, DelimToken::Paren, _) => match prev {
TokenTree::Token(token) => match token.kind {
token::Ident(_, _) => false,
_ => true,
},
_ => true,
},
TokenTree::Delimited(_, DelimToken::Bracket, _) => match prev {
TokenTree::Token(token) => match token.kind {
token::Pound => false,
_ => true,
},
_ => true,
},
TokenTree::Delimited(..) => true,
}
}
fn binop_to_string(op: BinOpToken) -> &'static str {
match op {
token::Plus => "+",
token::Minus => "-",
token::Star => "*",
token::Slash => "/",
token::Percent => "%",
token::Caret => "^",
token::And => "&",
token::Or => "|",
token::Shl => "<<",
token::Shr => ">>",
}
}
pub fn literal_to_string(lit: token::Lit) -> String {
let token::Lit { kind, symbol, suffix } = lit;
let mut out = match kind {
token::Byte => format!("b'{}'", symbol),
token::Char => format!("'{}'", symbol),
token::Str => format!("\"{}\"", symbol),
token::StrRaw(n) => {
format!("r{delim}\"{string}\"{delim}", delim = "#".repeat(n as usize), string = symbol)
}
token::ByteStr => format!("b\"{}\"", symbol),
token::ByteStrRaw(n) => {
format!("br{delim}\"{string}\"{delim}", delim = "#".repeat(n as usize), string = symbol)
}
token::Integer | token::Float | token::Bool | token::Err => symbol.to_string(),
};
if let Some(suffix) = suffix {
out.push_str(&suffix.as_str())
}
out
}
/// Print the token kind precisely, without converting `$crate` into its respective crate name.
pub fn token_kind_to_string(tok: &TokenKind) -> String {
token_kind_to_string_ext(tok, None)
}
fn token_kind_to_string_ext(tok: &TokenKind, convert_dollar_crate: Option<Span>) -> String {
match *tok {
token::Eq => "=".to_string(),
token::Lt => "<".to_string(),
token::Le => "<=".to_string(),
token::EqEq => "==".to_string(),
token::Ne => "!=".to_string(),
token::Ge => ">=".to_string(),
token::Gt => ">".to_string(),
token::Not => "!".to_string(),
token::Tilde => "~".to_string(),
token::OrOr => "||".to_string(),
token::AndAnd => "&&".to_string(),
token::BinOp(op) => binop_to_string(op).to_string(),
token::BinOpEq(op) => format!("{}=", binop_to_string(op)),
/* Structural symbols */
token::At => "@".to_string(),
token::Dot => ".".to_string(),
token::DotDot => "..".to_string(),
token::DotDotDot => "...".to_string(),
token::DotDotEq => "..=".to_string(),
token::Comma => ",".to_string(),
token::Semi => ";".to_string(),
token::Colon => ":".to_string(),
token::ModSep => "::".to_string(),
token::RArrow => "->".to_string(),
token::LArrow => "<-".to_string(),
token::FatArrow => "=>".to_string(),
token::OpenDelim(token::Paren) => "(".to_string(),
token::CloseDelim(token::Paren) => ")".to_string(),
token::OpenDelim(token::Bracket) => "[".to_string(),
token::CloseDelim(token::Bracket) => "]".to_string(),
token::OpenDelim(token::Brace) => "{".to_string(),
token::CloseDelim(token::Brace) => "}".to_string(),
token::OpenDelim(token::NoDelim) | token::CloseDelim(token::NoDelim) => "".to_string(),
token::Pound => "#".to_string(),
token::Dollar => "$".to_string(),
token::Question => "?".to_string(),
token::SingleQuote => "'".to_string(),
/* Literals */
token::Literal(lit) => literal_to_string(lit),
/* Name components */
token::Ident(s, is_raw) => IdentPrinter::new(s, is_raw, convert_dollar_crate).to_string(),
token::Lifetime(s) => s.to_string(),
/* Other */
token::DocComment(s) => s.to_string(),
token::Eof => "<eof>".to_string(),
token::Whitespace => " ".to_string(),
token::Comment => "/* */".to_string(),
token::Shebang(s) => format!("/* shebang: {}*/", s),
token::Unknown(s) => s.to_string(),
token::Interpolated(ref nt) => nonterminal_to_string(nt),
}
}
/// Print the token precisely, without converting `$crate` into its respective crate name.
pub fn token_to_string(token: &Token) -> String {
token_to_string_ext(token, false)
}
fn token_to_string_ext(token: &Token, convert_dollar_crate: bool) -> String {
let convert_dollar_crate = convert_dollar_crate.then_some(token.span);
token_kind_to_string_ext(&token.kind, convert_dollar_crate)
}
pub fn nonterminal_to_string(nt: &Nonterminal) -> String {
match *nt {
token::NtExpr(ref e) => expr_to_string(e),
token::NtMeta(ref e) => attr_item_to_string(e),
token::NtTy(ref e) => ty_to_string(e),
token::NtPath(ref e) => path_to_string(e),
token::NtItem(ref e) => item_to_string(e),
token::NtBlock(ref e) => block_to_string(e),
token::NtStmt(ref e) => stmt_to_string(e),
token::NtPat(ref e) => pat_to_string(e),
token::NtIdent(e, is_raw) => IdentPrinter::for_ast_ident(e, is_raw).to_string(),
token::NtLifetime(e) => e.to_string(),
token::NtLiteral(ref e) => expr_to_string(e),
token::NtTT(ref tree) => tt_to_string(tree),
token::NtVis(ref e) => vis_to_string(e),
}
}
pub fn ty_to_string(ty: &ast::Ty) -> String {
to_string(|s| s.print_type(ty))
}
pub fn bounds_to_string(bounds: &[ast::GenericBound]) -> String {
to_string(|s| s.print_type_bounds("", bounds))
}
pub fn pat_to_string(pat: &ast::Pat) -> String {
to_string(|s| s.print_pat(pat))
}
pub fn expr_to_string(e: &ast::Expr) -> String {
to_string(|s| s.print_expr(e))
}
pub fn tt_to_string(tt: &TokenTree) -> String {
to_string(|s| s.print_tt(tt, false))
}
pub fn tts_to_string(tokens: &TokenStream) -> String {
to_string(|s| s.print_tts(tokens, false))
}
pub fn stmt_to_string(stmt: &ast::Stmt) -> String {
to_string(|s| s.print_stmt(stmt))
}
pub fn item_to_string(i: &ast::Item) -> String {
to_string(|s| s.print_item(i))
}
pub fn generic_params_to_string(generic_params: &[ast::GenericParam]) -> String {
to_string(|s| s.print_generic_params(generic_params))
}
pub fn path_to_string(p: &ast::Path) -> String {
to_string(|s| s.print_path(p, false, 0))
}
pub fn path_segment_to_string(p: &ast::PathSegment) -> String {
to_string(|s| s.print_path_segment(p, false))
}
pub fn vis_to_string(v: &ast::Visibility) -> String {
to_string(|s| s.print_visibility(v))
}
fn block_to_string(blk: &ast::Block) -> String {
to_string(|s| {
// Containing cbox, will be closed by `print_block` at `}`.
s.cbox(INDENT_UNIT);
// Head-ibox, will be closed by `print_block` after `{`.
s.ibox(0);
s.print_block(blk)
})
}
pub fn meta_list_item_to_string(li: &ast::NestedMetaItem) -> String {
to_string(|s| s.print_meta_list_item(li))
}
fn attr_item_to_string(ai: &ast::AttrItem) -> String {
to_string(|s| s.print_attr_item(ai, ai.path.span))
}
pub fn attribute_to_string(attr: &ast::Attribute) -> String {
to_string(|s| s.print_attribute(attr))
}
pub fn param_to_string(arg: &ast::Param) -> String {
to_string(|s| s.print_param(arg, false))
}
fn visibility_qualified(vis: &ast::Visibility, s: &str) -> String {
format!("{}{}", to_string(|s| s.print_visibility(vis)), s)
}
impl std::ops::Deref for State<'_> {
type Target = pp::Printer;
fn deref(&self) -> &Self::Target {
&self.s
}
}
impl std::ops::DerefMut for State<'_> {
fn deref_mut(&mut self) -> &mut Self::Target {
&mut self.s
}
}
pub trait PrintState<'a>: std::ops::Deref<Target = pp::Printer> + std::ops::DerefMut {
fn comments(&mut self) -> &mut Option<Comments<'a>>;
fn print_ident(&mut self, ident: Ident);
fn print_generic_args(&mut self, args: &ast::GenericArgs, colons_before_params: bool);
fn strsep<T, F>(
&mut self,
sep: &'static str,
space_before: bool,
b: Breaks,
elts: &[T],
mut op: F,
) where
F: FnMut(&mut Self, &T),
{
self.rbox(0, b);
if let Some((first, rest)) = elts.split_first() {
op(self, first);
for elt in rest {
if space_before {
self.space();
}
self.word_space(sep);
op(self, elt);
}
}
self.end();
}
fn commasep<T, F>(&mut self, b: Breaks, elts: &[T], op: F)
where
F: FnMut(&mut Self, &T),
{
self.strsep(",", false, b, elts, op)
}
fn maybe_print_comment(&mut self, pos: BytePos) {
while let Some(ref cmnt) = self.next_comment() {
if cmnt.pos < pos {
self.print_comment(cmnt);
} else {
break;
}
}
}
fn print_comment(&mut self, cmnt: &comments::Comment) {
match cmnt.style {
comments::Mixed => {
assert_eq!(cmnt.lines.len(), 1);
self.zerobreak();
self.word(cmnt.lines[0].clone());
self.zerobreak()
}
comments::Isolated => {
self.hardbreak_if_not_bol();
for line in &cmnt.lines {
// Don't print empty lines because they will end up as trailing
// whitespace.
if !line.is_empty() {
self.word(line.clone());
}
self.hardbreak();
}
}
comments::Trailing => {
if !self.is_beginning_of_line() {
self.word(" ");
}
if cmnt.lines.len() == 1 {
self.word(cmnt.lines[0].clone());
self.hardbreak()
} else {
self.ibox(0);
for line in &cmnt.lines {
if !line.is_empty() {
self.word(line.clone());
}
self.hardbreak();
}
self.end();
}
}
comments::BlankLine => {
// We need to do at least one, possibly two hardbreaks.
let twice = match self.last_token() {
pp::Token::String(s) => ";" == s,
pp::Token::Begin(_) => true,
pp::Token::End => true,
_ => false,
};
if twice {
self.hardbreak();
}
self.hardbreak();
}
}
if let Some(cmnts) = self.comments() {
cmnts.current += 1;
}
}
fn next_comment(&mut self) -> Option<comments::Comment> {
self.comments().as_mut().and_then(|c| c.next())
}
fn print_literal(&mut self, lit: &ast::Lit) {
self.maybe_print_comment(lit.span.lo());
self.word(lit.token.to_string())
}
fn print_string(&mut self, st: &str, style: ast::StrStyle) {
let st = match style {
ast::StrStyle::Cooked => (format!("\"{}\"", st.escape_debug())),
ast::StrStyle::Raw(n) => {
format!("r{delim}\"{string}\"{delim}", delim = "#".repeat(n as usize), string = st)
}
};
self.word(st)
}
fn print_inner_attributes(&mut self, attrs: &[ast::Attribute]) {
self.print_either_attributes(attrs, ast::AttrStyle::Inner, false, true)
}
fn print_inner_attributes_no_trailing_hardbreak(&mut self, attrs: &[ast::Attribute]) {
self.print_either_attributes(attrs, ast::AttrStyle::Inner, false, false)
}
fn print_outer_attributes(&mut self, attrs: &[ast::Attribute]) {
self.print_either_attributes(attrs, ast::AttrStyle::Outer, false, true)
}
fn print_inner_attributes_inline(&mut self, attrs: &[ast::Attribute]) {
self.print_either_attributes(attrs, ast::AttrStyle::Inner, true, true)
}
fn print_outer_attributes_inline(&mut self, attrs: &[ast::Attribute]) {
self.print_either_attributes(attrs, ast::AttrStyle::Outer, true, true)
}
fn print_either_attributes(
&mut self,
attrs: &[ast::Attribute],
kind: ast::AttrStyle,
is_inline: bool,
trailing_hardbreak: bool,
) {
let mut count = 0;
for attr in attrs {
if attr.style == kind {
self.print_attribute_inline(attr, is_inline);
if is_inline {
self.nbsp();
}
count += 1;
}
}
if count > 0 && trailing_hardbreak && !is_inline {
self.hardbreak_if_not_bol();
}
}
fn print_attribute(&mut self, attr: &ast::Attribute) {
self.print_attribute_inline(attr, false)
}
fn print_attribute_inline(&mut self, attr: &ast::Attribute, is_inline: bool) {
if !is_inline {
self.hardbreak_if_not_bol();
}
self.maybe_print_comment(attr.span.lo());
match attr.kind {
ast::AttrKind::Normal(ref item) => {
match attr.style {
ast::AttrStyle::Inner => self.word("#!["),
ast::AttrStyle::Outer => self.word("#["),
}
self.print_attr_item(&item, attr.span);
self.word("]");
}
ast::AttrKind::DocComment(comment) => {
self.word(comment.to_string());
self.hardbreak()
}
}
}
fn print_attr_item(&mut self, item: &ast::AttrItem, span: Span) {
self.ibox(0);
match &item.args {
MacArgs::Delimited(_, delim, tokens) => self.print_mac_common(
Some(MacHeader::Path(&item.path)),
false,
None,
delim.to_token(),
tokens,
true,
span,
),
MacArgs::Empty | MacArgs::Eq(..) => {
self.print_path(&item.path, false, 0);
if let MacArgs::Eq(_, tokens) = &item.args {
self.space();
self.word_space("=");
self.print_tts(tokens, true);
}
}
}
self.end();
}
fn print_meta_list_item(&mut self, item: &ast::NestedMetaItem) {
match item {
ast::NestedMetaItem::MetaItem(ref mi) => self.print_meta_item(mi),
ast::NestedMetaItem::Literal(ref lit) => self.print_literal(lit),
}
}
fn print_meta_item(&mut self, item: &ast::MetaItem) {
self.ibox(INDENT_UNIT);
match item.kind {
ast::MetaItemKind::Word => self.print_path(&item.path, false, 0),
ast::MetaItemKind::NameValue(ref value) => {
self.print_path(&item.path, false, 0);
self.space();
self.word_space("=");
self.print_literal(value);
}
ast::MetaItemKind::List(ref items) => {
self.print_path(&item.path, false, 0);
self.popen();
self.commasep(Consistent, &items[..], |s, i| s.print_meta_list_item(i));
self.pclose();
}
}
self.end();
}
/// This doesn't deserve to be called "pretty" printing, but it should be
/// meaning-preserving. A quick hack that might help would be to look at the
/// spans embedded in the TTs to decide where to put spaces and newlines.
/// But it'd be better to parse these according to the grammar of the
/// appropriate macro, transcribe back into the grammar we just parsed from,
/// and then pretty-print the resulting AST nodes (so, e.g., we print
/// expression arguments as expressions). It can be done! I think.
fn print_tt(&mut self, tt: &TokenTree, convert_dollar_crate: bool) {
match tt {
TokenTree::Token(token) => {
self.word(token_to_string_ext(&token, convert_dollar_crate));
if let token::DocComment(..) = token.kind {
self.hardbreak()
}
}
TokenTree::Delimited(dspan, delim, tts) => {
self.print_mac_common(
None,
false,
None,
*delim,
tts,
convert_dollar_crate,
dspan.entire(),
);
}
}
}
fn print_tts(&mut self, tts: &TokenStream, convert_dollar_crate: bool) {
let mut iter = tts.trees().peekable();
while let Some(tt) = iter.next() {
self.print_tt(&tt, convert_dollar_crate);
if let Some(next) = iter.peek() {
if tt_prepend_space(next, &tt) {
self.space();
}
}
}
}
fn print_mac_common(
&mut self,
header: Option<MacHeader<'_>>,
has_bang: bool,
ident: Option<Ident>,
delim: DelimToken,
tts: &TokenStream,
convert_dollar_crate: bool,
span: Span,
) {
if delim == DelimToken::Brace {
self.cbox(INDENT_UNIT);
}
match header {
Some(MacHeader::Path(path)) => self.print_path(path, false, 0),
Some(MacHeader::Keyword(kw)) => self.word(kw),
None => {}
}
if has_bang {
self.word("!");
}
if let Some(ident) = ident {
self.nbsp();
self.print_ident(ident);
}
match delim {
DelimToken::Brace => {
if header.is_some() || has_bang || ident.is_some() {
self.nbsp();
}
self.word("{");
if !tts.is_empty() {
self.space();
}
}
_ => self.word(token_kind_to_string(&token::OpenDelim(delim))),
}
self.ibox(0);
self.print_tts(tts, convert_dollar_crate);
self.end();
match delim {
DelimToken::Brace => self.bclose(span),
_ => self.word(token_kind_to_string(&token::CloseDelim(delim))),
}
}
fn print_path(&mut self, path: &ast::Path, colons_before_params: bool, depth: usize) {
self.maybe_print_comment(path.span.lo());
for (i, segment) in path.segments[..path.segments.len() - depth].iter().enumerate() {
if i > 0 {
self.word("::")
}
self.print_path_segment(segment, colons_before_params);
}
}
fn print_path_segment(&mut self, segment: &ast::PathSegment, colons_before_params: bool) {
if segment.ident.name != kw::PathRoot {
self.print_ident(segment.ident);
if let Some(ref args) = segment.args {
self.print_generic_args(args, colons_before_params);
}
}
}
fn head<S: Into<Cow<'static, str>>>(&mut self, w: S) {
let w = w.into();
// Outer-box is consistent.
self.cbox(INDENT_UNIT);
// Head-box is inconsistent.
self.ibox(w.len() + 1);
// Keyword that starts the head.
if !w.is_empty() {
self.word_nbsp(w);
}
}
fn bopen(&mut self) {
self.word("{");
self.end(); // Close the head-box.
}
fn bclose_maybe_open(&mut self, span: rustc_span::Span, close_box: bool) {
self.maybe_print_comment(span.hi());
self.break_offset_if_not_bol(1, -(INDENT_UNIT as isize));
self.word("}");
if close_box {
self.end(); // Close the outer-box.
}
}
fn bclose(&mut self, span: rustc_span::Span) {
self.bclose_maybe_open(span, true)
}
fn break_offset_if_not_bol(&mut self, n: usize, off: isize) {
if !self.is_beginning_of_line() {
self.break_offset(n, off)
} else {
if off != 0 && self.last_token().is_hardbreak_tok() {
// We do something pretty sketchy here: tuck the nonzero
// offset-adjustment we were going to deposit along with the
// break into the previous hardbreak.
self.replace_last_token(pp::Printer::hardbreak_tok_offset(off));
}
}
}
}
impl<'a> PrintState<'a> for State<'a> {
fn comments(&mut self) -> &mut Option<Comments<'a>> {
&mut self.comments
}
fn print_ident(&mut self, ident: Ident) {
self.s.word(IdentPrinter::for_ast_ident(ident, ident.is_raw_guess()).to_string());
self.ann.post(self, AnnNode::Ident(&ident))
}
fn print_generic_args(&mut self, args: &ast::GenericArgs, colons_before_params: bool) {
if colons_before_params {
self.s.word("::")
}
match *args {
ast::GenericArgs::AngleBracketed(ref data) => {
self.s.word("<");
self.commasep(Inconsistent, &data.args, |s, arg| match arg {
ast::AngleBracketedArg::Arg(a) => s.print_generic_arg(a),
ast::AngleBracketedArg::Constraint(c) => s.print_assoc_constraint(c),
});
self.s.word(">")
}
ast::GenericArgs::Parenthesized(ref data) => {
self.s.word("(");
self.commasep(Inconsistent, &data.inputs, |s, ty| s.print_type(ty));
self.s.word(")");
self.print_fn_ret_ty(&data.output);
}
}
}
}
impl<'a> State<'a> {
// Synthesizes a comment that was not textually present in the original source
// file.
pub fn synth_comment(&mut self, text: String) {
self.s.word("/*");
self.s.space();
self.s.word(text);
self.s.space();
self.s.word("*/")
}
crate fn commasep_cmnt<T, F, G>(&mut self, b: Breaks, elts: &[T], mut op: F, mut get_span: G)
where
F: FnMut(&mut State<'_>, &T),
G: FnMut(&T) -> rustc_span::Span,
{
self.rbox(0, b);
let len = elts.len();
let mut i = 0;
for elt in elts {
self.maybe_print_comment(get_span(elt).hi());
op(self, elt);
i += 1;
if i < len {
self.s.word(",");
self.maybe_print_trailing_comment(get_span(elt), Some(get_span(&elts[i]).hi()));
self.space_if_not_bol();
}
}
self.end();
}
crate fn commasep_exprs(&mut self, b: Breaks, exprs: &[P<ast::Expr>]) {
self.commasep_cmnt(b, exprs, |s, e| s.print_expr(e), |e| e.span)
}
pub fn print_mod(&mut self, _mod: &ast::Mod, attrs: &[ast::Attribute]) {
self.print_inner_attributes(attrs);
for item in &_mod.items {
self.print_item(item);
}
}
crate fn print_foreign_mod(&mut self, nmod: &ast::ForeignMod, attrs: &[Attribute]) {
self.print_inner_attributes(attrs);
for item in &nmod.items {
self.print_foreign_item(item);
}
}
pub fn print_opt_lifetime(&mut self, lifetime: &Option<ast::Lifetime>) {
if let Some(lt) = *lifetime {
self.print_lifetime(lt);
self.nbsp();
}
}
pub fn print_assoc_constraint(&mut self, constraint: &ast::AssocTyConstraint) {
self.print_ident(constraint.ident);
self.s.space();
match &constraint.kind {
ast::AssocTyConstraintKind::Equality { ty } => {
self.word_space("=");
self.print_type(ty);
}
ast::AssocTyConstraintKind::Bound { bounds } => {
self.print_type_bounds(":", &*bounds);
}
}
}
pub fn print_generic_arg(&mut self, generic_arg: &GenericArg) {
match generic_arg {
GenericArg::Lifetime(lt) => self.print_lifetime(*lt),
GenericArg::Type(ty) => self.print_type(ty),
GenericArg::Const(ct) => self.print_expr(&ct.value),
}
}
pub fn print_type(&mut self, ty: &ast::Ty) {
self.maybe_print_comment(ty.span.lo());
self.ibox(0);
match ty.kind {
ast::TyKind::Slice(ref ty) => {
self.s.word("[");
self.print_type(ty);
self.s.word("]");
}
ast::TyKind::Ptr(ref mt) => {
self.s.word("*");
self.print_mt(mt, true);
}
ast::TyKind::Rptr(ref lifetime, ref mt) => {
self.s.word("&");
self.print_opt_lifetime(lifetime);
self.print_mt(mt, false);
}
ast::TyKind::Never => {
self.s.word("!");
}
ast::TyKind::Tup(ref elts) => {
self.popen();
self.commasep(Inconsistent, &elts[..], |s, ty| s.print_type(ty));
if elts.len() == 1 {
self.s.word(",");
}
self.pclose();
}
ast::TyKind::Paren(ref typ) => {
self.popen();
self.print_type(typ);
self.pclose();
}
ast::TyKind::BareFn(ref f) => {
self.print_ty_fn(f.ext, f.unsafety, &f.decl, None, &f.generic_params);
}
ast::TyKind::Path(None, ref path) => {
self.print_path(path, false, 0);
}
ast::TyKind::Path(Some(ref qself), ref path) => self.print_qpath(path, qself, false),
ast::TyKind::TraitObject(ref bounds, syntax) => {
let prefix = if syntax == ast::TraitObjectSyntax::Dyn { "dyn" } else { "" };
self.print_type_bounds(prefix, &bounds[..]);
}
ast::TyKind::ImplTrait(_, ref bounds) => {
self.print_type_bounds("impl", &bounds[..]);
}
ast::TyKind::Array(ref ty, ref length) => {
self.s.word("[");
self.print_type(ty);
self.s.word("; ");
self.print_expr(&length.value);
self.s.word("]");
}
ast::TyKind::Typeof(ref e) => {
self.s.word("typeof(");
self.print_expr(&e.value);
self.s.word(")");
}
ast::TyKind::Infer => {
self.s.word("_");
}
ast::TyKind::Err => {
self.popen();
self.s.word("/*ERROR*/");
self.pclose();
}
ast::TyKind::ImplicitSelf => {
self.s.word("Self");
}
ast::TyKind::MacCall(ref m) => {
self.print_mac(m);
}
ast::TyKind::CVarArgs => {
self.s.word("...");
}
}
self.end();
}
crate fn print_foreign_item(&mut self, item: &ast::ForeignItem) {
let ast::Item { id, span, ident, ref attrs, ref kind, ref vis, tokens: _ } = *item;
self.ann.pre(self, AnnNode::SubItem(id));
self.hardbreak_if_not_bol();
self.maybe_print_comment(span.lo());
self.print_outer_attributes(attrs);
match kind {
ast::ForeignItemKind::Fn(def, sig, gen, body) => {
self.print_fn_full(sig, ident, gen, vis, *def, body.as_deref(), attrs);
}
ast::ForeignItemKind::Static(ty, mutbl, body) => {
let def = ast::Defaultness::Final;
self.print_item_const(ident, Some(*mutbl), ty, body.as_deref(), vis, def);
}
ast::ForeignItemKind::TyAlias(def, generics, bounds, ty) => {
self.print_associated_type(ident, generics, bounds, ty.as_deref(), vis, *def);
}
ast::ForeignItemKind::MacCall(m) => {
self.print_mac(m);
if m.args.need_semicolon() {
self.s.word(";");
}
}
}
self.ann.post(self, AnnNode::SubItem(id))
}
fn print_item_const(
&mut self,
ident: Ident,
mutbl: Option<ast::Mutability>,
ty: &ast::Ty,
body: Option<&ast::Expr>,
vis: &ast::Visibility,
defaultness: ast::Defaultness,
) {
self.head("");
self.print_visibility(vis);
self.print_defaultness(defaultness);
let leading = match mutbl {
None => "const",
Some(ast::Mutability::Not) => "static",
Some(ast::Mutability::Mut) => "static mut",
};
self.word_space(leading);
self.print_ident(ident);
self.word_space(":");
self.print_type(ty);
self.s.space();
self.end(); // end the head-ibox
if let Some(body) = body {
self.word_space("=");
self.print_expr(body);
}
self.s.word(";");
self.end(); // end the outer cbox
}
fn print_associated_type(
&mut self,
ident: Ident,
generics: &ast::Generics,
bounds: &ast::GenericBounds,
ty: Option<&ast::Ty>,
vis: &ast::Visibility,
defaultness: ast::Defaultness,
) {
self.head("");
self.print_visibility(vis);
self.print_defaultness(defaultness);
self.word_space("type");
self.print_ident(ident);
self.print_generic_params(&generics.params);
self.print_type_bounds(":", bounds);
self.print_where_clause(&generics.where_clause);
if let Some(ty) = ty {
self.s.space();
self.word_space("=");
self.print_type(ty);
}
self.s.word(";");
self.end(); // end inner head-block
self.end(); // end outer head-block
}
/// Pretty-prints an item.
crate fn print_item(&mut self, item: &ast::Item) {
self.hardbreak_if_not_bol();
self.maybe_print_comment(item.span.lo());
self.print_outer_attributes(&item.attrs);
self.ann.pre(self, AnnNode::Item(item));
match item.kind {
ast::ItemKind::ExternCrate(orig_name) => {
self.head(visibility_qualified(&item.vis, "extern crate"));
if let Some(orig_name) = orig_name {
self.print_name(orig_name);
self.s.space();
self.s.word("as");
self.s.space();
}
self.print_ident(item.ident);
self.s.word(";");
self.end(); // end inner head-block
self.end(); // end outer head-block
}
ast::ItemKind::Use(ref tree) => {
self.head(visibility_qualified(&item.vis, "use"));
self.print_use_tree(tree);
self.s.word(";");
self.end(); // end inner head-block
self.end(); // end outer head-block
}
ast::ItemKind::Static(ref ty, mutbl, ref body) => {
let def = ast::Defaultness::Final;
self.print_item_const(item.ident, Some(mutbl), ty, body.as_deref(), &item.vis, def);
}
ast::ItemKind::Const(def, ref ty, ref body) => {
self.print_item_const(item.ident, None, ty, body.as_deref(), &item.vis, def);
}
ast::ItemKind::Fn(def, ref sig, ref gen, ref body) => {
let body = body.as_deref();
self.print_fn_full(sig, item.ident, gen, &item.vis, def, body, &item.attrs);
}
ast::ItemKind::Mod(ref _mod) => {
self.head(visibility_qualified(&item.vis, "mod"));
self.print_ident(item.ident);
if _mod.inline || self.is_expanded {
self.nbsp();
self.bopen();
self.print_mod(_mod, &item.attrs);
self.bclose(item.span);
} else {
self.s.word(";");
self.end(); // end inner head-block
self.end(); // end outer head-block
}
}
ast::ItemKind::ForeignMod(ref nmod) => {
self.head("extern");
if let Some(abi) = nmod.abi {
self.print_literal(&abi.as_lit());
self.nbsp();
}
self.bopen();
self.print_foreign_mod(nmod, &item.attrs);
self.bclose(item.span);
}
ast::ItemKind::GlobalAsm(ref ga) => {
self.head(visibility_qualified(&item.vis, "global_asm!"));
self.s.word(ga.asm.to_string());
self.end();
}
ast::ItemKind::TyAlias(def, ref generics, ref bounds, ref ty) => {
let ty = ty.as_deref();
self.print_associated_type(item.ident, generics, bounds, ty, &item.vis, def);
}
ast::ItemKind::Enum(ref enum_definition, ref params) => {
self.print_enum_def(enum_definition, params, item.ident, item.span, &item.vis);
}
ast::ItemKind::Struct(ref struct_def, ref generics) => {
self.head(visibility_qualified(&item.vis, "struct"));
self.print_struct(struct_def, generics, item.ident, item.span, true);
}
ast::ItemKind::Union(ref struct_def, ref generics) => {
self.head(visibility_qualified(&item.vis, "union"));
self.print_struct(struct_def, generics, item.ident, item.span, true);
}
ast::ItemKind::Impl {
unsafety,
polarity,
defaultness,
constness,
ref generics,
ref of_trait,
ref self_ty,
ref items,
} => {
self.head("");
self.print_visibility(&item.vis);
self.print_defaultness(defaultness);
self.print_unsafety(unsafety);
self.word_nbsp("impl");
self.print_constness(constness);
if !generics.params.is_empty() {
self.print_generic_params(&generics.params);
self.s.space();
}
if let ast::ImplPolarity::Negative(_) = polarity {
self.s.word("!");
}
if let Some(ref t) = *of_trait {
self.print_trait_ref(t);
self.s.space();
self.word_space("for");
}
self.print_type(self_ty);
self.print_where_clause(&generics.where_clause);
self.s.space();
self.bopen();
self.print_inner_attributes(&item.attrs);
for impl_item in items {
self.print_assoc_item(impl_item);
}
self.bclose(item.span);
}
ast::ItemKind::Trait(is_auto, unsafety, ref generics, ref bounds, ref trait_items) => {
self.head("");
self.print_visibility(&item.vis);
self.print_unsafety(unsafety);
self.print_is_auto(is_auto);
self.word_nbsp("trait");
self.print_ident(item.ident);
self.print_generic_params(&generics.params);
let mut real_bounds = Vec::with_capacity(bounds.len());
for b in bounds.iter() {
if let GenericBound::Trait(ref ptr, ast::TraitBoundModifier::Maybe) = *b {
self.s.space();
self.word_space("for ?");
self.print_trait_ref(&ptr.trait_ref);
} else {
real_bounds.push(b.clone());
}
}
self.print_type_bounds(":", &real_bounds[..]);
self.print_where_clause(&generics.where_clause);
self.s.word(" ");
self.bopen();
self.print_inner_attributes(&item.attrs);
for trait_item in trait_items {
self.print_assoc_item(trait_item);
}
self.bclose(item.span);
}
ast::ItemKind::TraitAlias(ref generics, ref bounds) => {
self.head("");
self.print_visibility(&item.vis);
self.word_nbsp("trait");
self.print_ident(item.ident);
self.print_generic_params(&generics.params);
let mut real_bounds = Vec::with_capacity(bounds.len());
// FIXME(durka) this seems to be some quite outdated syntax
for b in bounds.iter() {
if let GenericBound::Trait(ref ptr, ast::TraitBoundModifier::Maybe) = *b {
self.s.space();
self.word_space("for ?");
self.print_trait_ref(&ptr.trait_ref);
} else {
real_bounds.push(b.clone());
}
}
self.nbsp();
self.print_type_bounds("=", &real_bounds[..]);
self.print_where_clause(&generics.where_clause);
self.s.word(";");
}
ast::ItemKind::MacCall(ref mac) => {
self.print_mac(mac);
if mac.args.need_semicolon() {
self.s.word(";");
}
}
ast::ItemKind::MacroDef(ref macro_def) => {
let (kw, has_bang) = if macro_def.macro_rules {
("macro_rules", true)
} else {
self.print_visibility(&item.vis);
("macro", false)
};
self.print_mac_common(
Some(MacHeader::Keyword(kw)),
has_bang,
Some(item.ident),
macro_def.body.delim(),
&macro_def.body.inner_tokens(),
true,
item.span,
);
}
}
self.ann.post(self, AnnNode::Item(item))
}
fn print_trait_ref(&mut self, t: &ast::TraitRef) {
self.print_path(&t.path, false, 0)
}
fn print_formal_generic_params(&mut self, generic_params: &[ast::GenericParam]) {
if !generic_params.is_empty() {
self.s.word("for");
self.print_generic_params(generic_params);
self.nbsp();
}
}
fn print_poly_trait_ref(&mut self, t: &ast::PolyTraitRef) {
self.print_formal_generic_params(&t.bound_generic_params);
self.print_trait_ref(&t.trait_ref)
}
crate fn print_enum_def(
&mut self,
enum_definition: &ast::EnumDef,
generics: &ast::Generics,
ident: Ident,
span: rustc_span::Span,
visibility: &ast::Visibility,
) {
self.head(visibility_qualified(visibility, "enum"));
self.print_ident(ident);
self.print_generic_params(&generics.params);
self.print_where_clause(&generics.where_clause);
self.s.space();
self.print_variants(&enum_definition.variants, span)
}
crate fn print_variants(&mut self, variants: &[ast::Variant], span: rustc_span::Span) {
self.bopen();
for v in variants {
self.space_if_not_bol();
self.maybe_print_comment(v.span.lo());
self.print_outer_attributes(&v.attrs);
self.ibox(INDENT_UNIT);
self.print_variant(v);
self.s.word(",");
self.end();
self.maybe_print_trailing_comment(v.span, None);
}
self.bclose(span)
}
crate fn print_visibility(&mut self, vis: &ast::Visibility) {
match vis.node {
ast::VisibilityKind::Public => self.word_nbsp("pub"),
ast::VisibilityKind::Crate(sugar) => match sugar {
ast::CrateSugar::PubCrate => self.word_nbsp("pub(crate)"),
ast::CrateSugar::JustCrate => self.word_nbsp("crate"),
},
ast::VisibilityKind::Restricted { ref path, .. } => {
let path = to_string(|s| s.print_path(path, false, 0));
if path == "self" || path == "super" {
self.word_nbsp(format!("pub({})", path))
} else {
self.word_nbsp(format!("pub(in {})", path))
}
}
ast::VisibilityKind::Inherited => {}
}
}
crate fn print_defaultness(&mut self, defaultness: ast::Defaultness) {
if let ast::Defaultness::Default(_) = defaultness {
self.word_nbsp("default");
}
}
crate fn print_struct(
&mut self,
struct_def: &ast::VariantData,
generics: &ast::Generics,
ident: Ident,
span: rustc_span::Span,
print_finalizer: bool,
) {
self.print_ident(ident);
self.print_generic_params(&generics.params);
match struct_def {
ast::VariantData::Tuple(..) | ast::VariantData::Unit(..) => {
if let ast::VariantData::Tuple(..) = struct_def {
self.popen();
self.commasep(Inconsistent, struct_def.fields(), |s, field| {
s.maybe_print_comment(field.span.lo());
s.print_outer_attributes(&field.attrs);
s.print_visibility(&field.vis);
s.print_type(&field.ty)
});
self.pclose();
}
self.print_where_clause(&generics.where_clause);
if print_finalizer {
self.s.word(";");
}
self.end();
self.end(); // Close the outer-box.
}
ast::VariantData::Struct(..) => {
self.print_where_clause(&generics.where_clause);
self.nbsp();
self.bopen();
self.hardbreak_if_not_bol();
for field in struct_def.fields() {
self.hardbreak_if_not_bol();
self.maybe_print_comment(field.span.lo());
self.print_outer_attributes(&field.attrs);
self.print_visibility(&field.vis);
self.print_ident(field.ident.unwrap());
self.word_nbsp(":");
self.print_type(&field.ty);
self.s.word(",");
}
self.bclose(span)
}
}
}
crate fn print_variant(&mut self, v: &ast::Variant) {
self.head("");
self.print_visibility(&v.vis);
let generics = ast::Generics::default();
self.print_struct(&v.data, &generics, v.ident, v.span, false);
if let Some(ref d) = v.disr_expr {
self.s.space();
self.word_space("=");
self.print_expr(&d.value)
}
}
crate fn print_assoc_item(&mut self, item: &ast::AssocItem) {
let ast::Item { id, span, ident, ref attrs, ref kind, ref vis, tokens: _ } = *item;
self.ann.pre(self, AnnNode::SubItem(id));
self.hardbreak_if_not_bol();
self.maybe_print_comment(span.lo());
self.print_outer_attributes(attrs);
match kind {
ast::AssocItemKind::Fn(def, sig, gen, body) => {
self.print_fn_full(sig, ident, gen, vis, *def, body.as_deref(), attrs);
}
ast::AssocItemKind::Const(def, ty, body) => {
self.print_item_const(ident, None, ty, body.as_deref(), vis, *def);
}
ast::AssocItemKind::TyAlias(def, generics, bounds, ty) => {
self.print_associated_type(ident, generics, bounds, ty.as_deref(), vis, *def);
}
ast::AssocItemKind::MacCall(m) => {
self.print_mac(m);
if m.args.need_semicolon() {
self.s.word(";");
}
}
}
self.ann.post(self, AnnNode::SubItem(id))
}
crate fn print_stmt(&mut self, st: &ast::Stmt) {
self.maybe_print_comment(st.span.lo());
match st.kind {
ast::StmtKind::Local(ref loc) => {
self.print_outer_attributes(&loc.attrs);
self.space_if_not_bol();
self.ibox(INDENT_UNIT);
self.word_nbsp("let");
self.ibox(INDENT_UNIT);
self.print_local_decl(loc);
self.end();
if let Some(ref init) = loc.init {
self.nbsp();
self.word_space("=");
self.print_expr(init);
}
self.s.word(";");
self.end();
}
ast::StmtKind::Item(ref item) => self.print_item(item),
ast::StmtKind::Expr(ref expr) => {
self.space_if_not_bol();
self.print_expr_outer_attr_style(expr, false);
if classify::expr_requires_semi_to_be_stmt(expr) {
self.s.word(";");
}
}
ast::StmtKind::Semi(ref expr) => {
self.space_if_not_bol();
self.print_expr_outer_attr_style(expr, false);
self.s.word(";");
}
ast::StmtKind::Empty => {
self.space_if_not_bol();
self.s.word(";");
}
ast::StmtKind::MacCall(ref mac) => {
let (ref mac, style, ref attrs) = **mac;
self.space_if_not_bol();
self.print_outer_attributes(attrs);
self.print_mac(mac);
if style == ast::MacStmtStyle::Semicolon {
self.s.word(";");
}
}
}
self.maybe_print_trailing_comment(st.span, None)
}
crate fn print_block(&mut self, blk: &ast::Block) {
self.print_block_with_attrs(blk, &[])
}
crate fn print_block_unclosed_indent(&mut self, blk: &ast::Block) {
self.print_block_maybe_unclosed(blk, &[], false)
}
crate fn print_block_with_attrs(&mut self, blk: &ast::Block, attrs: &[ast::Attribute]) {
self.print_block_maybe_unclosed(blk, attrs, true)
}
crate fn print_block_maybe_unclosed(
&mut self,
blk: &ast::Block,
attrs: &[ast::Attribute],
close_box: bool,
) {
match blk.rules {
BlockCheckMode::Unsafe(..) => self.word_space("unsafe"),
BlockCheckMode::Default => (),
}
self.maybe_print_comment(blk.span.lo());
self.ann.pre(self, AnnNode::Block(blk));
self.bopen();
self.print_inner_attributes(attrs);
for (i, st) in blk.stmts.iter().enumerate() {
match st.kind {
ast::StmtKind::Expr(ref expr) if i == blk.stmts.len() - 1 => {
self.maybe_print_comment(st.span.lo());
self.space_if_not_bol();
self.print_expr_outer_attr_style(expr, false);
self.maybe_print_trailing_comment(expr.span, Some(blk.span.hi()));
}
_ => self.print_stmt(st),
}
}
self.bclose_maybe_open(blk.span, close_box);
self.ann.post(self, AnnNode::Block(blk))
}
/// Print a `let pat = scrutinee` expression.
crate fn print_let(&mut self, pat: &ast::Pat, scrutinee: &ast::Expr) {
self.s.word("let ");
self.print_pat(pat);
self.s.space();
self.word_space("=");
self.print_expr_cond_paren(
scrutinee,
Self::cond_needs_par(scrutinee)
|| parser::needs_par_as_let_scrutinee(scrutinee.precedence().order()),
)
}
fn print_else(&mut self, els: Option<&ast::Expr>) {
if let Some(_else) = els {
match _else.kind {
// Another `else if` block.
ast::ExprKind::If(ref i, ref then, ref e) => {
self.cbox(INDENT_UNIT - 1);
self.ibox(0);
self.s.word(" else if ");
self.print_expr_as_cond(i);
self.s.space();
self.print_block(then);
self.print_else(e.as_deref())
}
// Final `else` block.
ast::ExprKind::Block(ref b, _) => {
self.cbox(INDENT_UNIT - 1);
self.ibox(0);
self.s.word(" else ");
self.print_block(b)
}
// Constraints would be great here!
_ => {
panic!("print_if saw if with weird alternative");
}
}
}
}
crate fn print_if(&mut self, test: &ast::Expr, blk: &ast::Block, elseopt: Option<&ast::Expr>) {
self.head("if");
self.print_expr_as_cond(test);
self.s.space();
self.print_block(blk);
self.print_else(elseopt)
}
crate fn print_mac(&mut self, m: &ast::MacCall) {
self.print_mac_common(
Some(MacHeader::Path(&m.path)),
true,
None,
m.args.delim(),
&m.args.inner_tokens(),
true,
m.span(),
);
}
fn print_call_post(&mut self, args: &[P<ast::Expr>]) {
self.popen();
self.commasep_exprs(Inconsistent, args);
self.pclose()
}
crate fn print_expr_maybe_paren(&mut self, expr: &ast::Expr, prec: i8) {
self.print_expr_cond_paren(expr, expr.precedence().order() < prec)
}
/// Prints an expr using syntax that's acceptable in a condition position, such as the `cond` in
/// `if cond { ... }`.
crate fn print_expr_as_cond(&mut self, expr: &ast::Expr) {
self.print_expr_cond_paren(expr, Self::cond_needs_par(expr))
}
/// Does `expr` need parenthesis when printed in a condition position?
fn cond_needs_par(expr: &ast::Expr) -> bool {
match expr.kind {
// These cases need parens due to the parse error observed in #26461: `if return {}`
// parses as the erroneous construct `if (return {})`, not `if (return) {}`.
ast::ExprKind::Closure(..) | ast::ExprKind::Ret(..) | ast::ExprKind::Break(..) => true,
_ => parser::contains_exterior_struct_lit(expr),
}
}
/// Prints `expr` or `(expr)` when `needs_par` holds.
fn print_expr_cond_paren(&mut self, expr: &ast::Expr, needs_par: bool) {
if needs_par {
self.popen();
}
self.print_expr(expr);
if needs_par {
self.pclose();
}
}
fn print_expr_vec(&mut self, exprs: &[P<ast::Expr>], attrs: &[Attribute]) {
self.ibox(INDENT_UNIT);
self.s.word("[");
self.print_inner_attributes_inline(attrs);
self.commasep_exprs(Inconsistent, &exprs[..]);
self.s.word("]");
self.end();
}
fn print_expr_repeat(
&mut self,
element: &ast::Expr,
count: &ast::AnonConst,
attrs: &[Attribute],
) {
self.ibox(INDENT_UNIT);
self.s.word("[");
self.print_inner_attributes_inline(attrs);
self.print_expr(element);
self.word_space(";");
self.print_expr(&count.value);
self.s.word("]");
self.end();
}
fn print_expr_struct(
&mut self,
path: &ast::Path,
fields: &[ast::Field],
wth: &Option<P<ast::Expr>>,
attrs: &[Attribute],
) {
self.print_path(path, true, 0);
self.s.word("{");
self.print_inner_attributes_inline(attrs);
self.commasep_cmnt(
Consistent,
&fields[..],
|s, field| {
s.print_outer_attributes(&field.attrs);
s.ibox(INDENT_UNIT);
if !field.is_shorthand {
s.print_ident(field.ident);
s.word_space(":");
}
s.print_expr(&field.expr);
s.end();
},
|f| f.span,
);
match *wth {
Some(ref expr) => {
self.ibox(INDENT_UNIT);
if !fields.is_empty() {
self.s.word(",");
self.s.space();
}
self.s.word("..");
self.print_expr(expr);
self.end();
}
_ => {
if !fields.is_empty() {
self.s.word(",")
}
}
}
self.s.word("}");
}
fn print_expr_tup(&mut self, exprs: &[P<ast::Expr>], attrs: &[Attribute]) {
self.popen();
self.print_inner_attributes_inline(attrs);
self.commasep_exprs(Inconsistent, &exprs[..]);
if exprs.len() == 1 {
self.s.word(",");
}
self.pclose()
}
fn print_expr_call(&mut self, func: &ast::Expr, args: &[P<ast::Expr>]) {
let prec = match func.kind {
ast::ExprKind::Field(..) => parser::PREC_FORCE_PAREN,
_ => parser::PREC_POSTFIX,
};
self.print_expr_maybe_paren(func, prec);
self.print_call_post(args)
}
fn print_expr_method_call(&mut self, segment: &ast::PathSegment, args: &[P<ast::Expr>]) {
let base_args = &args[1..];
self.print_expr_maybe_paren(&args[0], parser::PREC_POSTFIX);
self.s.word(".");
self.print_ident(segment.ident);
if let Some(ref args) = segment.args {
self.print_generic_args(args, true);
}
self.print_call_post(base_args)
}
fn print_expr_binary(&mut self, op: ast::BinOp, lhs: &ast::Expr, rhs: &ast::Expr) {
let assoc_op = AssocOp::from_ast_binop(op.node);
let prec = assoc_op.precedence() as i8;
let fixity = assoc_op.fixity();
let (left_prec, right_prec) = match fixity {
Fixity::Left => (prec, prec + 1),
Fixity::Right => (prec + 1, prec),
Fixity::None => (prec + 1, prec + 1),
};
let left_prec = match (&lhs.kind, op.node) {
// These cases need parens: `x as i32 < y` has the parser thinking that `i32 < y` is
// the beginning of a path type. It starts trying to parse `x as (i32 < y ...` instead
// of `(x as i32) < ...`. We need to convince it _not_ to do that.
(&ast::ExprKind::Cast { .. }, ast::BinOpKind::Lt | ast::BinOpKind::Shl) => {
parser::PREC_FORCE_PAREN
}
// We are given `(let _ = a) OP b`.
//
// - When `OP <= LAnd` we should print `let _ = a OP b` to avoid redundant parens
// as the parser will interpret this as `(let _ = a) OP b`.
//
// - Otherwise, e.g. when we have `(let a = b) < c` in AST,
// parens are required since the parser would interpret `let a = b < c` as
// `let a = (b < c)`. To achieve this, we force parens.
(&ast::ExprKind::Let { .. }, _) if !parser::needs_par_as_let_scrutinee(prec) => {
parser::PREC_FORCE_PAREN
}
_ => left_prec,
};
self.print_expr_maybe_paren(lhs, left_prec);
self.s.space();
self.word_space(op.node.to_string());
self.print_expr_maybe_paren(rhs, right_prec)
}
fn print_expr_unary(&mut self, op: ast::UnOp, expr: &ast::Expr) {
self.s.word(ast::UnOp::to_string(op));
self.print_expr_maybe_paren(expr, parser::PREC_PREFIX)
}
fn print_expr_addr_of(
&mut self,
kind: ast::BorrowKind,
mutability: ast::Mutability,
expr: &ast::Expr,
) {
self.s.word("&");
match kind {
ast::BorrowKind::Ref => self.print_mutability(mutability, false),
ast::BorrowKind::Raw => {
self.word_nbsp("raw");
self.print_mutability(mutability, true);
}
}
self.print_expr_maybe_paren(expr, parser::PREC_PREFIX)
}
pub fn print_expr(&mut self, expr: &ast::Expr) {
self.print_expr_outer_attr_style(expr, true)
}
fn print_expr_outer_attr_style(&mut self, expr: &ast::Expr, is_inline: bool) {
self.maybe_print_comment(expr.span.lo());
let attrs = &expr.attrs;
if is_inline {
self.print_outer_attributes_inline(attrs);
} else {
self.print_outer_attributes(attrs);
}
self.ibox(INDENT_UNIT);
self.ann.pre(self, AnnNode::Expr(expr));
match expr.kind {
ast::ExprKind::Box(ref expr) => {
self.word_space("box");
self.print_expr_maybe_paren(expr, parser::PREC_PREFIX);
}
ast::ExprKind::Array(ref exprs) => {
self.print_expr_vec(&exprs[..], attrs);
}
ast::ExprKind::Repeat(ref element, ref count) => {
self.print_expr_repeat(element, count, attrs);
}
ast::ExprKind::Struct(ref path, ref fields, ref wth) => {
self.print_expr_struct(path, &fields[..], wth, attrs);
}
ast::ExprKind::Tup(ref exprs) => {
self.print_expr_tup(&exprs[..], attrs);
}
ast::ExprKind::Call(ref func, ref args) => {
self.print_expr_call(func, &args[..]);
}
ast::ExprKind::MethodCall(ref segment, ref args, _) => {
self.print_expr_method_call(segment, &args[..]);
}
ast::ExprKind::Binary(op, ref lhs, ref rhs) => {
self.print_expr_binary(op, lhs, rhs);
}
ast::ExprKind::Unary(op, ref expr) => {
self.print_expr_unary(op, expr);
}
ast::ExprKind::AddrOf(k, m, ref expr) => {
self.print_expr_addr_of(k, m, expr);
}
ast::ExprKind::Lit(ref lit) => {
self.print_literal(lit);
}
ast::ExprKind::Cast(ref expr, ref ty) => {
let prec = AssocOp::As.precedence() as i8;
self.print_expr_maybe_paren(expr, prec);
self.s.space();
self.word_space("as");
self.print_type(ty);
}
ast::ExprKind::Type(ref expr, ref ty) => {
let prec = AssocOp::Colon.precedence() as i8;
self.print_expr_maybe_paren(expr, prec);
self.word_space(":");
self.print_type(ty);
}
ast::ExprKind::Let(ref pat, ref scrutinee) => {
self.print_let(pat, scrutinee);
}
ast::ExprKind::If(ref test, ref blk, ref elseopt) => {
self.print_if(test, blk, elseopt.as_deref())
}
ast::ExprKind::While(ref test, ref blk, opt_label) => {
if let Some(label) = opt_label {
self.print_ident(label.ident);
self.word_space(":");
}
self.head("while");
self.print_expr_as_cond(test);
self.s.space();
self.print_block_with_attrs(blk, attrs);
}
ast::ExprKind::ForLoop(ref pat, ref iter, ref blk, opt_label) => {
if let Some(label) = opt_label {
self.print_ident(label.ident);
self.word_space(":");
}
self.head("for");
self.print_pat(pat);
self.s.space();
self.word_space("in");
self.print_expr_as_cond(iter);
self.s.space();
self.print_block_with_attrs(blk, attrs);
}
ast::ExprKind::Loop(ref blk, opt_label) => {
if let Some(label) = opt_label {
self.print_ident(label.ident);
self.word_space(":");
}
self.head("loop");
self.s.space();
self.print_block_with_attrs(blk, attrs);
}
ast::ExprKind::Match(ref expr, ref arms) => {
self.cbox(INDENT_UNIT);
self.ibox(INDENT_UNIT);
self.word_nbsp("match");
self.print_expr_as_cond(expr);
self.s.space();
self.bopen();
self.print_inner_attributes_no_trailing_hardbreak(attrs);
for arm in arms {
self.print_arm(arm);
}
self.bclose(expr.span);
}
ast::ExprKind::Closure(
capture_clause,
asyncness,
movability,
ref decl,
ref body,
_,
) => {
self.print_movability(movability);
self.print_asyncness(asyncness);
self.print_capture_clause(capture_clause);
self.print_fn_params_and_ret(decl, true);
self.s.space();
self.print_expr(body);
self.end(); // need to close a box
// a box will be closed by print_expr, but we didn't want an overall
// wrapper so we closed the corresponding opening. so create an
// empty box to satisfy the close.
self.ibox(0);
}
ast::ExprKind::Block(ref blk, opt_label) => {
if let Some(label) = opt_label {
self.print_ident(label.ident);
self.word_space(":");
}
// containing cbox, will be closed by print-block at }
self.cbox(INDENT_UNIT);
// head-box, will be closed by print-block after {
self.ibox(0);
self.print_block_with_attrs(blk, attrs);
}
ast::ExprKind::Async(capture_clause, _, ref blk) => {
self.word_nbsp("async");
self.print_capture_clause(capture_clause);
self.s.space();
// cbox/ibox in analogy to the `ExprKind::Block` arm above
self.cbox(INDENT_UNIT);
self.ibox(0);
self.print_block_with_attrs(blk, attrs);
}
ast::ExprKind::Await(ref expr) => {
self.print_expr_maybe_paren(expr, parser::PREC_POSTFIX);
self.s.word(".await");
}
ast::ExprKind::Assign(ref lhs, ref rhs, _) => {
let prec = AssocOp::Assign.precedence() as i8;
self.print_expr_maybe_paren(lhs, prec + 1);
self.s.space();
self.word_space("=");
self.print_expr_maybe_paren(rhs, prec);
}
ast::ExprKind::AssignOp(op, ref lhs, ref rhs) => {
let prec = AssocOp::Assign.precedence() as i8;
self.print_expr_maybe_paren(lhs, prec + 1);
self.s.space();
self.s.word(op.node.to_string());
self.word_space("=");
self.print_expr_maybe_paren(rhs, prec);
}
ast::ExprKind::Field(ref expr, ident) => {
self.print_expr_maybe_paren(expr, parser::PREC_POSTFIX);
self.s.word(".");
self.print_ident(ident);
}
ast::ExprKind::Index(ref expr, ref index) => {
self.print_expr_maybe_paren(expr, parser::PREC_POSTFIX);
self.s.word("[");
self.print_expr(index);
self.s.word("]");
}
ast::ExprKind::Range(ref start, ref end, limits) => {
// Special case for `Range`. `AssocOp` claims that `Range` has higher precedence
// than `Assign`, but `x .. x = x` gives a parse error instead of `x .. (x = x)`.
// Here we use a fake precedence value so that any child with lower precedence than
// a "normal" binop gets parenthesized. (`LOr` is the lowest-precedence binop.)
let fake_prec = AssocOp::LOr.precedence() as i8;
if let Some(ref e) = *start {
self.print_expr_maybe_paren(e, fake_prec);
}
if limits == ast::RangeLimits::HalfOpen {
self.s.word("..");
} else {
self.s.word("..=");
}
if let Some(ref e) = *end {
self.print_expr_maybe_paren(e, fake_prec);
}
}
ast::ExprKind::Path(None, ref path) => self.print_path(path, true, 0),
ast::ExprKind::Path(Some(ref qself), ref path) => self.print_qpath(path, qself, true),
ast::ExprKind::Break(opt_label, ref opt_expr) => {
self.s.word("break");
self.s.space();
if let Some(label) = opt_label {
self.print_ident(label.ident);
self.s.space();
}
if let Some(ref expr) = *opt_expr {
self.print_expr_maybe_paren(expr, parser::PREC_JUMP);
self.s.space();
}
}
ast::ExprKind::Continue(opt_label) => {
self.s.word("continue");
self.s.space();
if let Some(label) = opt_label {
self.print_ident(label.ident);
self.s.space()
}
}
ast::ExprKind::Ret(ref result) => {
self.s.word("return");
if let Some(ref expr) = *result {
self.s.word(" ");
self.print_expr_maybe_paren(expr, parser::PREC_JUMP);
}
}
ast::ExprKind::InlineAsm(ref a) => {
enum AsmArg<'a> {
Template(String),
Operand(&'a InlineAsmOperand),
Options(InlineAsmOptions),
}
let mut args = vec![];
args.push(AsmArg::Template(InlineAsmTemplatePiece::to_string(&a.template)));
args.extend(a.operands.iter().map(|(o, _)| AsmArg::Operand(o)));
if !a.options.is_empty() {
args.push(AsmArg::Options(a.options));
}
self.word("asm!");
self.popen();
self.commasep(Consistent, &args, |s, arg| match arg {
AsmArg::Template(template) => s.print_string(&template, ast::StrStyle::Cooked),
AsmArg::Operand(op) => {
let print_reg_or_class = |s: &mut Self, r: &InlineAsmRegOrRegClass| match r
{
InlineAsmRegOrRegClass::Reg(r) => {
s.print_string(&r.as_str(), ast::StrStyle::Cooked)
}
InlineAsmRegOrRegClass::RegClass(r) => s.word(r.to_string()),
};
match op {
InlineAsmOperand::In { reg, expr } => {
s.word("in");
s.popen();
print_reg_or_class(s, reg);
s.pclose();
s.space();
s.print_expr(expr);
}
InlineAsmOperand::Out { reg, late, expr } => {
s.word(if *late { "lateout" } else { "out" });
s.popen();
print_reg_or_class(s, reg);
s.pclose();
s.space();
match expr {
Some(expr) => s.print_expr(expr),
None => s.word("_"),
}
}
InlineAsmOperand::InOut { reg, late, expr } => {
s.word(if *late { "inlateout" } else { "inout" });
s.popen();
print_reg_or_class(s, reg);
s.pclose();
s.space();
s.print_expr(expr);
}
InlineAsmOperand::SplitInOut { reg, late, in_expr, out_expr } => {
s.word(if *late { "inlateout" } else { "inout" });
s.popen();
print_reg_or_class(s, reg);
s.pclose();
s.space();
s.print_expr(in_expr);
s.space();
s.word_space("=>");
match out_expr {
Some(out_expr) => s.print_expr(out_expr),
None => s.word("_"),
}
}
InlineAsmOperand::Const { expr } => {
s.word("const");
s.space();
s.print_expr(expr);
}
InlineAsmOperand::Sym { expr } => {
s.word("sym");
s.space();
s.print_expr(expr);
}
}
}
AsmArg::Options(opts) => {
s.word("options");
s.popen();
let mut options = vec![];
if opts.contains(InlineAsmOptions::PURE) {
options.push("pure");
}
if opts.contains(InlineAsmOptions::NOMEM) {
options.push("nomem");
}
if opts.contains(InlineAsmOptions::READONLY) {
options.push("readonly");
}
if opts.contains(InlineAsmOptions::PRESERVES_FLAGS) {
options.push("preserves_flags");
}
if opts.contains(InlineAsmOptions::NORETURN) {
options.push("noreturn");
}
if opts.contains(InlineAsmOptions::NOSTACK) {
options.push("nostack");
}
if opts.contains(InlineAsmOptions::ATT_SYNTAX) {
options.push("att_syntax");
}
s.commasep(Inconsistent, &options, |s, &opt| {
s.word(opt);
});
s.pclose();
}
});
self.pclose();
}
ast::ExprKind::LlvmInlineAsm(ref a) => {
self.s.word("llvm_asm!");
self.popen();
self.print_string(&a.asm.as_str(), a.asm_str_style);
self.word_space(":");
self.commasep(Inconsistent, &a.outputs, |s, out| {
let constraint = out.constraint.as_str();
let mut ch = constraint.chars();
match ch.next() {
Some('=') if out.is_rw => {
s.print_string(&format!("+{}", ch.as_str()), ast::StrStyle::Cooked)
}
_ => s.print_string(&constraint, ast::StrStyle::Cooked),
}
s.popen();
s.print_expr(&out.expr);
s.pclose();
});
self.s.space();
self.word_space(":");
self.commasep(Inconsistent, &a.inputs, |s, &(co, ref o)| {
s.print_string(&co.as_str(), ast::StrStyle::Cooked);
s.popen();
s.print_expr(o);
s.pclose();
});
self.s.space();
self.word_space(":");
self.commasep(Inconsistent, &a.clobbers, |s, co| {
s.print_string(&co.as_str(), ast::StrStyle::Cooked);
});
let mut options = vec![];
if a.volatile {
options.push("volatile");
}
if a.alignstack {
options.push("alignstack");
}
if a.dialect == ast::LlvmAsmDialect::Intel {
options.push("intel");
}
if !options.is_empty() {
self.s.space();
self.word_space(":");
self.commasep(Inconsistent, &options, |s, &co| {
s.print_string(co, ast::StrStyle::Cooked);
});
}
self.pclose();
}
ast::ExprKind::MacCall(ref m) => self.print_mac(m),
ast::ExprKind::Paren(ref e) => {
self.popen();
self.print_inner_attributes_inline(attrs);
self.print_expr(e);
self.pclose();
}
ast::ExprKind::Yield(ref e) => {
self.s.word("yield");
if let Some(ref expr) = *e {
self.s.space();
self.print_expr_maybe_paren(expr, parser::PREC_JUMP);
}
}
ast::ExprKind::Try(ref e) => {
self.print_expr_maybe_paren(e, parser::PREC_POSTFIX);
self.s.word("?")
}
ast::ExprKind::TryBlock(ref blk) => {
self.head("try");
self.s.space();
self.print_block_with_attrs(blk, attrs)
}
ast::ExprKind::Err => {
self.popen();
self.s.word("/*ERROR*/");
self.pclose()
}
}
self.ann.post(self, AnnNode::Expr(expr));
self.end();
}
crate fn print_local_decl(&mut self, loc: &ast::Local) {
self.print_pat(&loc.pat);
if let Some(ref ty) = loc.ty {
self.word_space(":");
self.print_type(ty);
}
}
pub fn print_usize(&mut self, i: usize) {
self.s.word(i.to_string())
}
crate fn print_name(&mut self, name: Symbol) {
self.s.word(name.to_string());
self.ann.post(self, AnnNode::Name(&name))
}
fn print_qpath(&mut self, path: &ast::Path, qself: &ast::QSelf, colons_before_params: bool) {
self.s.word("<");
self.print_type(&qself.ty);
if qself.position > 0 {
self.s.space();
self.word_space("as");
let depth = path.segments.len() - qself.position;
self.print_path(path, false, depth);
}
self.s.word(">");
self.s.word("::");
let item_segment = path.segments.last().unwrap();
self.print_ident(item_segment.ident);
if let Some(ref args) = item_segment.args {
self.print_generic_args(args, colons_before_params)
}
}
crate fn print_pat(&mut self, pat: &ast::Pat) {
self.maybe_print_comment(pat.span.lo());
self.ann.pre(self, AnnNode::Pat(pat));
/* Pat isn't normalized, but the beauty of it
is that it doesn't matter */
match pat.kind {
PatKind::Wild => self.s.word("_"),
PatKind::Ident(binding_mode, ident, ref sub) => {
match binding_mode {
ast::BindingMode::ByRef(mutbl) => {
self.word_nbsp("ref");
self.print_mutability(mutbl, false);
}
ast::BindingMode::ByValue(ast::Mutability::Not) => {}
ast::BindingMode::ByValue(ast::Mutability::Mut) => {
self.word_nbsp("mut");
}
}
self.print_ident(ident);
if let Some(ref p) = *sub {
self.s.space();
self.s.word_space("@");
self.print_pat(p);
}
}
PatKind::TupleStruct(ref path, ref elts) => {
self.print_path(path, true, 0);
self.popen();
self.commasep(Inconsistent, &elts[..], |s, p| s.print_pat(p));
self.pclose();
}
PatKind::Or(ref pats) => {
self.strsep("|", true, Inconsistent, &pats[..], |s, p| s.print_pat(p));
}
PatKind::Path(None, ref path) => {
self.print_path(path, true, 0);
}
PatKind::Path(Some(ref qself), ref path) => {
self.print_qpath(path, qself, false);
}
PatKind::Struct(ref path, ref fields, etc) => {
self.print_path(path, true, 0);
self.nbsp();
self.word_space("{");
self.commasep_cmnt(
Consistent,
&fields[..],
|s, f| {
s.cbox(INDENT_UNIT);
if !f.is_shorthand {
s.print_ident(f.ident);
s.word_nbsp(":");
}
s.print_pat(&f.pat);
s.end();
},
|f| f.pat.span,
);
if etc {
if !fields.is_empty() {
self.word_space(",");
}
self.s.word("..");
}
self.s.space();
self.s.word("}");
}
PatKind::Tuple(ref elts) => {
self.popen();
self.commasep(Inconsistent, &elts[..], |s, p| s.print_pat(p));
if elts.len() == 1 {
self.s.word(",");
}
self.pclose();
}
PatKind::Box(ref inner) => {
self.s.word("box ");
self.print_pat(inner);
}
PatKind::Ref(ref inner, mutbl) => {
self.s.word("&");
if mutbl == ast::Mutability::Mut {
self.s.word("mut ");
}
self.print_pat(inner);
}
PatKind::Lit(ref e) => self.print_expr(&**e),
PatKind::Range(ref begin, ref end, Spanned { node: ref end_kind, .. }) => {
if let Some(e) = begin {
self.print_expr(e);
self.s.space();
}
match *end_kind {
RangeEnd::Included(RangeSyntax::DotDotDot) => self.s.word("..."),
RangeEnd::Included(RangeSyntax::DotDotEq) => self.s.word("..="),
RangeEnd::Excluded => self.s.word(".."),
}
if let Some(e) = end {
self.print_expr(e);
}
}
PatKind::Slice(ref elts) => {
self.s.word("[");
self.commasep(Inconsistent, &elts[..], |s, p| s.print_pat(p));
self.s.word("]");
}
PatKind::Rest => self.s.word(".."),
PatKind::Paren(ref inner) => {
self.popen();
self.print_pat(inner);
self.pclose();
}
PatKind::MacCall(ref m) => self.print_mac(m),
}
self.ann.post(self, AnnNode::Pat(pat))
}
fn print_arm(&mut self, arm: &ast::Arm) {
// Note, I have no idea why this check is necessary, but here it is.
if arm.attrs.is_empty() {
self.s.space();
}
self.cbox(INDENT_UNIT);
self.ibox(0);
self.maybe_print_comment(arm.pat.span.lo());
self.print_outer_attributes(&arm.attrs);
self.print_pat(&arm.pat);
self.s.space();
if let Some(ref e) = arm.guard {
self.word_space("if");
self.print_expr(e);
self.s.space();
}
self.word_space("=>");
match arm.body.kind {
ast::ExprKind::Block(ref blk, opt_label) => {
if let Some(label) = opt_label {
self.print_ident(label.ident);
self.word_space(":");
}
// The block will close the pattern's ibox.
self.print_block_unclosed_indent(blk);
// If it is a user-provided unsafe block, print a comma after it.
if let BlockCheckMode::Unsafe(ast::UserProvided) = blk.rules {
self.s.word(",");
}
}
_ => {
self.end(); // Close the ibox for the pattern.
self.print_expr(&arm.body);
self.s.word(",");
}
}
self.end(); // Close enclosing cbox.
}
fn print_explicit_self(&mut self, explicit_self: &ast::ExplicitSelf) {
match explicit_self.node {
SelfKind::Value(m) => {
self.print_mutability(m, false);
self.s.word("self")
}
SelfKind::Region(ref lt, m) => {
self.s.word("&");
self.print_opt_lifetime(lt);
self.print_mutability(m, false);
self.s.word("self")
}
SelfKind::Explicit(ref typ, m) => {
self.print_mutability(m, false);
self.s.word("self");
self.word_space(":");
self.print_type(typ)
}
}
}
fn print_fn_full(
&mut self,
sig: &ast::FnSig,
name: Ident,
generics: &ast::Generics,
vis: &ast::Visibility,
defaultness: ast::Defaultness,
body: Option<&ast::Block>,
attrs: &[ast::Attribute],
) {
if body.is_some() {
self.head("");
}
self.print_visibility(vis);
self.print_defaultness(defaultness);
self.print_fn(&sig.decl, sig.header, Some(name), generics);
if let Some(body) = body {
self.nbsp();
self.print_block_with_attrs(body, attrs);
} else {
self.s.word(";");
}
}
crate fn print_fn(
&mut self,
decl: &ast::FnDecl,
header: ast::FnHeader,
name: Option<Ident>,
generics: &ast::Generics,
) {
self.print_fn_header_info(header);
if let Some(name) = name {
self.nbsp();
self.print_ident(name);
}
self.print_generic_params(&generics.params);
self.print_fn_params_and_ret(decl, false);
self.print_where_clause(&generics.where_clause)
}
crate fn print_fn_params_and_ret(&mut self, decl: &ast::FnDecl, is_closure: bool) {
let (open, close) = if is_closure { ("|", "|") } else { ("(", ")") };
self.word(open);
self.commasep(Inconsistent, &decl.inputs, |s, param| s.print_param(param, is_closure));
self.word(close);
self.print_fn_ret_ty(&decl.output)
}
crate fn print_movability(&mut self, movability: ast::Movability) {
match movability {
ast::Movability::Static => self.word_space("static"),
ast::Movability::Movable => {}
}
}
crate fn print_asyncness(&mut self, asyncness: ast::Async) {
if asyncness.is_async() {
self.word_nbsp("async");
}
}
crate fn print_capture_clause(&mut self, capture_clause: ast::CaptureBy) {
match capture_clause {
ast::CaptureBy::Value => self.word_space("move"),
ast::CaptureBy::Ref => {}
}
}
pub fn print_type_bounds(&mut self, prefix: &'static str, bounds: &[ast::GenericBound]) {
if !bounds.is_empty() {
self.s.word(prefix);
let mut first = true;
for bound in bounds {
if !(first && prefix.is_empty()) {
self.nbsp();
}
if first {
first = false;
} else {
self.word_space("+");
}
match bound {
GenericBound::Trait(tref, modifier) => {
if modifier == &TraitBoundModifier::Maybe {
self.s.word("?");
}
self.print_poly_trait_ref(tref);
}
GenericBound::Outlives(lt) => self.print_lifetime(*lt),
}
}
}
}
crate fn print_lifetime(&mut self, lifetime: ast::Lifetime) {
self.print_name(lifetime.ident.name)
}
crate fn print_lifetime_bounds(
&mut self,
lifetime: ast::Lifetime,
bounds: &ast::GenericBounds,
) {
self.print_lifetime(lifetime);
if !bounds.is_empty() {
self.s.word(": ");
for (i, bound) in bounds.iter().enumerate() {
if i != 0 {
self.s.word(" + ");
}
match bound {
ast::GenericBound::Outlives(lt) => self.print_lifetime(*lt),
_ => panic!(),
}
}
}
}
crate fn print_generic_params(&mut self, generic_params: &[ast::GenericParam]) {
if generic_params.is_empty() {
return;
}
self.s.word("<");
self.commasep(Inconsistent, &generic_params, |s, param| {
s.print_outer_attributes_inline(&param.attrs);
match param.kind {
ast::GenericParamKind::Lifetime => {
let lt = ast::Lifetime { id: param.id, ident: param.ident };
s.print_lifetime_bounds(lt, &param.bounds)
}
ast::GenericParamKind::Type { ref default } => {
s.print_ident(param.ident);
s.print_type_bounds(":", &param.bounds);
if let Some(ref default) = default {
s.s.space();
s.word_space("=");
s.print_type(default)
}
}
ast::GenericParamKind::Const { ref ty, kw_span: _ } => {
s.word_space("const");
s.print_ident(param.ident);
s.s.space();
s.word_space(":");
s.print_type(ty);
s.print_type_bounds(":", &param.bounds)
}
}
});
self.s.word(">");
}
crate fn print_where_clause(&mut self, where_clause: &ast::WhereClause) {
if where_clause.predicates.is_empty() && !where_clause.has_where_token {
return;
}
self.s.space();
self.word_space("where");
for (i, predicate) in where_clause.predicates.iter().enumerate() {
if i != 0 {
self.word_space(",");
}
match *predicate {
ast::WherePredicate::BoundPredicate(ast::WhereBoundPredicate {
ref bound_generic_params,
ref bounded_ty,
ref bounds,
..
}) => {
self.print_formal_generic_params(bound_generic_params);
self.print_type(bounded_ty);
self.print_type_bounds(":", bounds);
}
ast::WherePredicate::RegionPredicate(ast::WhereRegionPredicate {
ref lifetime,
ref bounds,
..
}) => {
self.print_lifetime_bounds(*lifetime, bounds);
}
ast::WherePredicate::EqPredicate(ast::WhereEqPredicate {
ref lhs_ty,
ref rhs_ty,
..
}) => {
self.print_type(lhs_ty);
self.s.space();
self.word_space("=");
self.print_type(rhs_ty);
}
}
}
}
crate fn print_use_tree(&mut self, tree: &ast::UseTree) {
match tree.kind {
ast::UseTreeKind::Simple(rename, ..) => {
self.print_path(&tree.prefix, false, 0);
if let Some(rename) = rename {
self.s.space();
self.word_space("as");
self.print_ident(rename);
}
}
ast::UseTreeKind::Glob => {
if !tree.prefix.segments.is_empty() {
self.print_path(&tree.prefix, false, 0);
self.s.word("::");
}
self.s.word("*");
}
ast::UseTreeKind::Nested(ref items) => {
if tree.prefix.segments.is_empty() {
self.s.word("{");
} else {
self.print_path(&tree.prefix, false, 0);
self.s.word("::{");
}
self.commasep(Inconsistent, &items[..], |this, &(ref tree, _)| {
this.print_use_tree(tree)
});
self.s.word("}");
}
}
}
pub fn print_mutability(&mut self, mutbl: ast::Mutability, print_const: bool) {
match mutbl {
ast::Mutability::Mut => self.word_nbsp("mut"),
ast::Mutability::Not => {
if print_const {
self.word_nbsp("const");
}
}
}
}
crate fn print_mt(&mut self, mt: &ast::MutTy, print_const: bool) {
self.print_mutability(mt.mutbl, print_const);
self.print_type(&mt.ty)
}
crate fn print_param(&mut self, input: &ast::Param, is_closure: bool) {
self.ibox(INDENT_UNIT);
self.print_outer_attributes_inline(&input.attrs);
match input.ty.kind {
ast::TyKind::Infer if is_closure => self.print_pat(&input.pat),
_ => {
if let Some(eself) = input.to_self() {
self.print_explicit_self(&eself);
} else {
let invalid = if let PatKind::Ident(_, ident, _) = input.pat.kind {
ident.name == kw::Invalid
} else {
false
};
if !invalid {
self.print_pat(&input.pat);
self.s.word(":");
self.s.space();
}
self.print_type(&input.ty);
}
}
}
self.end();
}
crate fn print_fn_ret_ty(&mut self, fn_ret_ty: &ast::FnRetTy) {
if let ast::FnRetTy::Ty(ty) = fn_ret_ty {
self.space_if_not_bol();
self.ibox(INDENT_UNIT);
self.word_space("->");
self.print_type(ty);
self.end();
self.maybe_print_comment(ty.span.lo());
}
}
crate fn print_ty_fn(
&mut self,
ext: ast::Extern,
unsafety: ast::Unsafe,
decl: &ast::FnDecl,
name: Option<Ident>,
generic_params: &[ast::GenericParam],
) {
self.ibox(INDENT_UNIT);
if !generic_params.is_empty() {
self.s.word("for");
self.print_generic_params(generic_params);
}
let generics = ast::Generics {
params: Vec::new(),
where_clause: ast::WhereClause {
has_where_token: false,
predicates: Vec::new(),
span: rustc_span::DUMMY_SP,
},
span: rustc_span::DUMMY_SP,
};
let header = ast::FnHeader { unsafety, ext, ..ast::FnHeader::default() };
self.print_fn(decl, header, name, &generics);
self.end();
}
crate fn maybe_print_trailing_comment(
&mut self,
span: rustc_span::Span,
next_pos: Option<BytePos>,
) {
if let Some(cmnts) = self.comments() {
if let Some(cmnt) = cmnts.trailing_comment(span, next_pos) {
self.print_comment(&cmnt);
}
}
}
crate fn print_remaining_comments(&mut self) {
// If there aren't any remaining comments, then we need to manually
// make sure there is a line break at the end.
if self.next_comment().is_none() {
self.s.hardbreak();
}
while let Some(ref cmnt) = self.next_comment() {
self.print_comment(cmnt);
}
}
crate fn print_fn_header_info(&mut self, header: ast::FnHeader) {
self.print_constness(header.constness);
self.print_asyncness(header.asyncness);
self.print_unsafety(header.unsafety);
match header.ext {
ast::Extern::None => {}
ast::Extern::Implicit => {
self.word_nbsp("extern");
}
ast::Extern::Explicit(abi) => {
self.word_nbsp("extern");
self.print_literal(&abi.as_lit());
self.nbsp();
}
}
self.s.word("fn")
}
crate fn print_unsafety(&mut self, s: ast::Unsafe) {
match s {
ast::Unsafe::No => {}
ast::Unsafe::Yes(_) => self.word_nbsp("unsafe"),
}
}
crate fn print_constness(&mut self, s: ast::Const) {
match s {
ast::Const::No => {}
ast::Const::Yes(_) => self.word_nbsp("const"),
}
}
crate fn print_is_auto(&mut self, s: ast::IsAuto) {
match s {
ast::IsAuto::Yes => self.word_nbsp("auto"),
ast::IsAuto::No => {}
}
}
}