mod delimited; mod expr; mod item; use crate::pp::Breaks::{Consistent, Inconsistent}; use crate::pp::{self, Breaks}; use rustc_ast::ptr::P; use rustc_ast::token::{self, BinOpToken, CommentKind, Delimiter, Nonterminal, Token, TokenKind}; use rustc_ast::tokenstream::{TokenStream, TokenTree}; use rustc_ast::util::classify; use rustc_ast::util::comments::{gather_comments, Comment, CommentStyle}; use rustc_ast::util::parser; use rustc_ast::{self as ast, BlockCheckMode, Mutability, PatKind, RangeEnd, RangeSyntax}; use rustc_ast::{attr, BindingAnnotation, ByRef, Term}; use rustc_ast::{GenericArg, MacArgs, MacArgsEq}; use rustc_ast::{GenericBound, SelfKind, TraitBoundModifier}; use rustc_ast::{InlineAsmOperand, InlineAsmRegOrRegClass}; use rustc_ast::{InlineAsmOptions, InlineAsmTemplatePiece}; 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 rustc_ast::attr::AttrIdGenerator; use std::borrow::Cow; pub use self::delimited::IterDelimited; 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, current: usize, } impl<'a> Comments<'a> { pub fn new(sm: &'a SourceMap, filename: FileName, input: String) -> Comments<'a> { let comments = gather_comments(sm, filename, input); Comments { sm, comments, current: 0 } } pub fn next(&self) -> Option { self.comments.get(self.current).cloned() } pub fn trailing_comment( &self, span: rustc_span::Span, next_pos: Option, ) -> Option { if let Some(cmnt) = self.next() { if cmnt.style != CommentStyle::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>, ann: &'a (dyn PpAnn + 'a), } pub(crate) const INDENT_UNIT: isize = 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, g: &AttrIdGenerator, ) -> String { let mut s = State { s: pp::Printer::new(), comments: Some(Comments::new(sm, filename, input)), ann }; if is_expanded && !krate.attrs.iter().any(|attr| attr.has_name(sym::no_core)) { // 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(g, 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(g, no_std_meta); s.print_attribute(&fake_attr); } } s.print_inner_attributes(&krate.attrs); for item in &krate.items { s.print_item(item); } s.print_remaining_comments(); s.ann.post(&mut s, AnnNode::Crate(krate)); s.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 matches!(token.kind, token::Dot | token::Dollar) { return false; } if let token::DocComment(comment_kind, ..) = token.kind { return comment_kind != CommentKind::Line; } } match tt { TokenTree::Token(token, _) => !matches!(token.kind, token::Comma | token::Not | token::Dot), TokenTree::Delimited(_, Delimiter::Parenthesis, _) => { !matches!(prev, TokenTree::Token(Token { kind: token::Ident(..), .. }, _)) } TokenTree::Delimited(_, Delimiter::Bracket, _) => { !matches!(prev, TokenTree::Token(Token { kind: token::Pound, .. }, _)) } 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 => ">>", } } fn doc_comment_to_string( comment_kind: CommentKind, attr_style: ast::AttrStyle, data: Symbol, ) -> String { match (comment_kind, attr_style) { (CommentKind::Line, ast::AttrStyle::Outer) => format!("///{}", data), (CommentKind::Line, ast::AttrStyle::Inner) => format!("//!{}", data), (CommentKind::Block, ast::AttrStyle::Outer) => format!("/**{}*/", data), (CommentKind::Block, ast::AttrStyle::Inner) => format!("/*!{}*/", data), } } 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 } 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 + std::ops::DerefMut { fn comments(&mut self) -> &mut Option>; fn print_ident(&mut self, ident: Ident); fn print_generic_args(&mut self, args: &ast::GenericArgs, colons_before_params: bool); fn strsep( &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(&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) -> bool { let mut has_comment = false; while let Some(ref cmnt) = self.next_comment() { if cmnt.pos < pos { has_comment = true; self.print_comment(cmnt); } else { break; } } has_comment } fn print_comment(&mut self, cmnt: &Comment) { match cmnt.style { CommentStyle::Mixed => { if !self.is_beginning_of_line() { self.zerobreak(); } if let Some((last, lines)) = cmnt.lines.split_last() { self.ibox(0); for line in lines { self.word(line.clone()); self.hardbreak() } self.word(last.clone()); self.space(); self.end(); } self.zerobreak() } CommentStyle::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(); } } CommentStyle::Trailing => { if !self.is_beginning_of_line() { self.word(" "); } if cmnt.lines.len() == 1 { self.word(cmnt.lines[0].clone()); self.hardbreak() } else { self.visual_align(); for line in &cmnt.lines { if !line.is_empty() { self.word(line.clone()); } self.hardbreak(); } self.end(); } } CommentStyle::BlankLine => { // We need to do at least one, possibly two hardbreaks. let twice = match self.last_token() { Some(pp::Token::String(s)) => ";" == s, Some(pp::Token::Begin(_)) => true, Some(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 { self.comments().as_mut().and_then(|c| c.next()) } fn maybe_print_trailing_comment(&mut self, span: rustc_span::Span, next_pos: Option) { if let Some(cmnts) = self.comments() { if let Some(cmnt) = cmnts.trailing_comment(span, next_pos) { self.print_comment(&cmnt); } } } 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.hardbreak(); } while let Some(ref cmnt) = self.next_comment() { self.print_comment(cmnt) } } fn print_literal(&mut self, lit: &ast::Lit) { self.maybe_print_comment(lit.span.lo()); self.word(lit.token_lit.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_symbol(&mut self, sym: Symbol, style: ast::StrStyle) { self.print_string(sym.as_str(), style); } fn print_inner_attributes(&mut self, attrs: &[ast::Attribute]) -> bool { self.print_either_attributes(attrs, ast::AttrStyle::Inner, false, true) } fn print_inner_attributes_no_trailing_hardbreak(&mut self, attrs: &[ast::Attribute]) -> bool { self.print_either_attributes(attrs, ast::AttrStyle::Inner, false, false) } fn print_outer_attributes(&mut self, attrs: &[ast::Attribute]) -> bool { self.print_either_attributes(attrs, ast::AttrStyle::Outer, false, true) } fn print_inner_attributes_inline(&mut self, attrs: &[ast::Attribute]) -> bool { self.print_either_attributes(attrs, ast::AttrStyle::Inner, true, true) } fn print_outer_attributes_inline(&mut self, attrs: &[ast::Attribute]) -> bool { 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, ) -> bool { let mut printed = false; for attr in attrs { if attr.style == kind { self.print_attribute_inline(attr, is_inline); if is_inline { self.nbsp(); } printed = true; } } if printed && trailing_hardbreak && !is_inline { self.hardbreak_if_not_bol(); } printed } 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 normal) => { match attr.style { ast::AttrStyle::Inner => self.word("#!["), ast::AttrStyle::Outer => self.word("#["), } self.print_attr_item(&normal.item, attr.span); self.word("]"); } ast::AttrKind::DocComment(comment_kind, data) => { self.word(doc_comment_to_string(comment_kind, attr.style, data)); 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, Some(delim.to_token()), tokens, true, span, ), MacArgs::Empty => { self.print_path(&item.path, false, 0); } MacArgs::Eq(_, MacArgsEq::Ast(expr)) => { self.print_path(&item.path, false, 0); self.space(); self.word_space("="); let token_str = self.expr_to_string(expr); self.word(token_str); } MacArgs::Eq(_, MacArgsEq::Hir(lit)) => { self.print_path(&item.path, false, 0); self.space(); self.word_space("="); let token_str = self.literal_to_string(lit); self.word(token_str); } } 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, _) => { let token_str = self.token_to_string_ext(&token, convert_dollar_crate); self.word(token_str); if let token::DocComment(..) = token.kind { self.hardbreak() } } TokenTree::Delimited(dspan, delim, tts) => { self.print_mac_common( None, false, None, Some(*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>, has_bang: bool, ident: Option, delim: Option, tts: &TokenStream, convert_dollar_crate: bool, span: Span, ) { if delim == Some(Delimiter::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 { Some(Delimiter::Brace) => { if header.is_some() || has_bang || ident.is_some() { self.nbsp(); } self.word("{"); if !tts.is_empty() { self.space(); } self.ibox(0); self.print_tts(tts, convert_dollar_crate); self.end(); let empty = tts.is_empty(); self.bclose(span, empty); } Some(delim) => { let token_str = self.token_kind_to_string(&token::OpenDelim(delim)); self.word(token_str); self.ibox(0); self.print_tts(tts, convert_dollar_crate); self.end(); let token_str = self.token_kind_to_string(&token::CloseDelim(delim)); self.word(token_str); } None => { self.ibox(0); self.print_tts(tts, convert_dollar_crate); self.end(); } } } fn print_mac_def( &mut self, macro_def: &ast::MacroDef, ident: &Ident, sp: Span, print_visibility: impl FnOnce(&mut Self), ) { let (kw, has_bang) = if macro_def.macro_rules { ("macro_rules", true) } else { print_visibility(self); ("macro", false) }; self.print_mac_common( Some(MacHeader::Keyword(kw)), has_bang, Some(*ident), macro_def.body.delim(), ¯o_def.body.inner_tokens(), true, sp, ); if macro_def.body.need_semicolon() { self.word(";"); } } 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>>(&mut self, w: S) { let w = w.into(); // Outer-box is consistent. self.cbox(INDENT_UNIT); // Head-box is inconsistent. self.ibox(0); // 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, empty: bool, close_box: bool) { let has_comment = self.maybe_print_comment(span.hi()); if !empty || has_comment { 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, empty: bool) { let close_box = true; self.bclose_maybe_open(span, empty, close_box) } 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 { if let Some(last_token) = self.last_token_still_buffered() { if 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_still_buffered(pp::Printer::hardbreak_tok_offset(off)); } } } } fn nonterminal_to_string(&self, nt: &Nonterminal) -> String { match *nt { token::NtExpr(ref e) => self.expr_to_string(e), token::NtMeta(ref e) => self.attr_item_to_string(e), token::NtTy(ref e) => self.ty_to_string(e), token::NtPath(ref e) => self.path_to_string(e), token::NtItem(ref e) => self.item_to_string(e), token::NtBlock(ref e) => self.block_to_string(e), token::NtStmt(ref e) => self.stmt_to_string(e), token::NtPat(ref e) => self.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) => self.expr_to_string(e), token::NtVis(ref e) => self.vis_to_string(e), } } /// Print the token kind precisely, without converting `$crate` into its respective crate name. fn token_kind_to_string(&self, tok: &TokenKind) -> Cow<'static, str> { self.token_kind_to_string_ext(tok, None) } fn token_kind_to_string_ext( &self, tok: &TokenKind, convert_dollar_crate: Option, ) -> Cow<'static, str> { match *tok { token::Eq => "=".into(), token::Lt => "<".into(), token::Le => "<=".into(), token::EqEq => "==".into(), token::Ne => "!=".into(), token::Ge => ">=".into(), token::Gt => ">".into(), token::Not => "!".into(), token::Tilde => "~".into(), token::OrOr => "||".into(), token::AndAnd => "&&".into(), token::BinOp(op) => binop_to_string(op).into(), token::BinOpEq(op) => format!("{}=", binop_to_string(op)).into(), /* Structural symbols */ token::At => "@".into(), token::Dot => ".".into(), token::DotDot => "..".into(), token::DotDotDot => "...".into(), token::DotDotEq => "..=".into(), token::Comma => ",".into(), token::Semi => ";".into(), token::Colon => ":".into(), token::ModSep => "::".into(), token::RArrow => "->".into(), token::LArrow => "<-".into(), token::FatArrow => "=>".into(), token::OpenDelim(Delimiter::Parenthesis) => "(".into(), token::CloseDelim(Delimiter::Parenthesis) => ")".into(), token::OpenDelim(Delimiter::Bracket) => "[".into(), token::CloseDelim(Delimiter::Bracket) => "]".into(), token::OpenDelim(Delimiter::Brace) => "{".into(), token::CloseDelim(Delimiter::Brace) => "}".into(), token::OpenDelim(Delimiter::Invisible) | token::CloseDelim(Delimiter::Invisible) => { "".into() } token::Pound => "#".into(), token::Dollar => "$".into(), token::Question => "?".into(), token::SingleQuote => "'".into(), /* Literals */ token::Literal(lit) => literal_to_string(lit).into(), /* Name components */ token::Ident(s, is_raw) => { IdentPrinter::new(s, is_raw, convert_dollar_crate).to_string().into() } token::Lifetime(s) => s.to_string().into(), /* Other */ token::DocComment(comment_kind, attr_style, data) => { doc_comment_to_string(comment_kind, attr_style, data).into() } token::Eof => "".into(), token::Interpolated(ref nt) => self.nonterminal_to_string(nt).into(), } } /// Print the token precisely, without converting `$crate` into its respective crate name. fn token_to_string(&self, token: &Token) -> Cow<'static, str> { self.token_to_string_ext(token, false) } fn token_to_string_ext(&self, token: &Token, convert_dollar_crate: bool) -> Cow<'static, str> { let convert_dollar_crate = convert_dollar_crate.then_some(token.span); self.token_kind_to_string_ext(&token.kind, convert_dollar_crate) } fn ty_to_string(&self, ty: &ast::Ty) -> String { Self::to_string(|s| s.print_type(ty)) } fn bounds_to_string(&self, bounds: &[ast::GenericBound]) -> String { Self::to_string(|s| s.print_type_bounds(bounds)) } fn pat_to_string(&self, pat: &ast::Pat) -> String { Self::to_string(|s| s.print_pat(pat)) } fn expr_to_string(&self, e: &ast::Expr) -> String { Self::to_string(|s| s.print_expr(e)) } fn literal_to_string(&self, lit: &ast::Lit) -> String { Self::to_string(|s| s.print_literal(lit)) } fn tt_to_string(&self, tt: &TokenTree) -> String { Self::to_string(|s| s.print_tt(tt, false)) } fn tts_to_string(&self, tokens: &TokenStream) -> String { Self::to_string(|s| s.print_tts(tokens, false)) } fn stmt_to_string(&self, stmt: &ast::Stmt) -> String { Self::to_string(|s| s.print_stmt(stmt)) } fn item_to_string(&self, i: &ast::Item) -> String { Self::to_string(|s| s.print_item(i)) } fn assoc_item_to_string(&self, i: &ast::AssocItem) -> String { Self::to_string(|s| s.print_assoc_item(i)) } fn foreign_item_to_string(&self, i: &ast::ForeignItem) -> String { Self::to_string(|s| s.print_foreign_item(i)) } fn generic_params_to_string(&self, generic_params: &[ast::GenericParam]) -> String { Self::to_string(|s| s.print_generic_params(generic_params)) } fn path_to_string(&self, p: &ast::Path) -> String { Self::to_string(|s| s.print_path(p, false, 0)) } fn path_segment_to_string(&self, p: &ast::PathSegment) -> String { Self::to_string(|s| s.print_path_segment(p, false)) } fn vis_to_string(&self, v: &ast::Visibility) -> String { Self::to_string(|s| s.print_visibility(v)) } fn block_to_string(&self, blk: &ast::Block) -> String { Self::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) }) } fn meta_list_item_to_string(&self, li: &ast::NestedMetaItem) -> String { Self::to_string(|s| s.print_meta_list_item(li)) } fn attr_item_to_string(&self, ai: &ast::AttrItem) -> String { Self::to_string(|s| s.print_attr_item(ai, ai.path.span)) } fn attribute_to_string(&self, attr: &ast::Attribute) -> String { Self::to_string(|s| s.print_attribute(attr)) } fn param_to_string(&self, arg: &ast::Param) -> String { Self::to_string(|s| s.print_param(arg, false)) } fn to_string(f: impl FnOnce(&mut State<'_>)) -> String { let mut printer = State::new(); f(&mut printer); printer.s.eof() } } impl<'a> PrintState<'a> for State<'a> { fn comments(&mut self) -> &mut Option> { &mut self.comments } fn print_ident(&mut self, ident: Ident) { self.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.word("::") } match *args { ast::GenericArgs::AngleBracketed(ref data) => { self.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.word(">") } ast::GenericArgs::Parenthesized(ref data) => { self.word("("); self.commasep(Inconsistent, &data.inputs, |s, ty| s.print_type(ty)); self.word(")"); self.print_fn_ret_ty(&data.output); } } } } impl<'a> State<'a> { pub fn new() -> State<'a> { State { s: pp::Printer::new(), comments: None, ann: &NoAnn } } pub(crate) fn commasep_cmnt( &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.word(","); self.maybe_print_trailing_comment(get_span(elt), Some(get_span(&elts[i]).hi())); self.space_if_not_bol(); } } self.end(); } pub(crate) fn commasep_exprs(&mut self, b: Breaks, exprs: &[P]) { self.commasep_cmnt(b, exprs, |s, e| s.print_expr(e), |e| e.span) } pub fn print_opt_lifetime(&mut self, lifetime: &Option) { if let Some(lt) = *lifetime { self.print_lifetime(lt); self.nbsp(); } } pub fn print_assoc_constraint(&mut self, constraint: &ast::AssocConstraint) { self.print_ident(constraint.ident); constraint.gen_args.as_ref().map(|args| self.print_generic_args(args, false)); self.space(); match &constraint.kind { ast::AssocConstraintKind::Equality { term } => { self.word_space("="); match term { Term::Ty(ty) => self.print_type(ty), Term::Const(c) => self.print_expr_anon_const(c, &[]), } } ast::AssocConstraintKind::Bound { bounds } => { if !bounds.is_empty() { self.word_nbsp(":"); 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.word("["); self.print_type(ty); self.word("]"); } ast::TyKind::Ptr(ref mt) => { self.word("*"); self.print_mt(mt, true); } ast::TyKind::Rptr(ref lifetime, ref mt) => { self.word("&"); self.print_opt_lifetime(lifetime); self.print_mt(mt, false); } ast::TyKind::Never => { self.word("!"); } ast::TyKind::Tup(ref elts) => { self.popen(); self.commasep(Inconsistent, &elts, |s, ty| s.print_type(ty)); if elts.len() == 1 { self.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) => { if syntax == ast::TraitObjectSyntax::Dyn { self.word_nbsp("dyn"); } self.print_type_bounds(bounds); } ast::TyKind::ImplTrait(_, ref bounds) => { self.word_nbsp("impl"); self.print_type_bounds(bounds); } ast::TyKind::Array(ref ty, ref length) => { self.word("["); self.print_type(ty); self.word("; "); self.print_expr(&length.value); self.word("]"); } ast::TyKind::Typeof(ref e) => { self.word("typeof("); self.print_expr(&e.value); self.word(")"); } ast::TyKind::Infer => { self.word("_"); } ast::TyKind::Err => { self.popen(); self.word("/*ERROR*/"); self.pclose(); } ast::TyKind::ImplicitSelf => { self.word("Self"); } ast::TyKind::MacCall(ref m) => { self.print_mac(m); } ast::TyKind::CVarArgs => { self.word("..."); } } self.end(); } 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.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) } pub(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((init, els)) = loc.kind.init_else_opt() { self.nbsp(); self.word_space("="); self.print_expr(init); if let Some(els) = els { self.cbox(INDENT_UNIT); self.ibox(INDENT_UNIT); self.word(" else "); self.print_block(els); } } self.word(";"); self.end(); // `let` ibox } 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.word(";"); } } ast::StmtKind::Semi(ref expr) => { self.space_if_not_bol(); self.print_expr_outer_attr_style(expr, false); self.word(";"); } ast::StmtKind::Empty => { self.space_if_not_bol(); self.word(";"); } ast::StmtKind::MacCall(ref mac) => { self.space_if_not_bol(); self.print_outer_attributes(&mac.attrs); self.print_mac(&mac.mac); if mac.style == ast::MacStmtStyle::Semicolon { self.word(";"); } } } self.maybe_print_trailing_comment(st.span, None) } pub(crate) fn print_block(&mut self, blk: &ast::Block) { self.print_block_with_attrs(blk, &[]) } pub(crate) fn print_block_unclosed_indent(&mut self, blk: &ast::Block) { self.print_block_maybe_unclosed(blk, &[], false) } pub(crate) fn print_block_with_attrs(&mut self, blk: &ast::Block, attrs: &[ast::Attribute]) { self.print_block_maybe_unclosed(blk, attrs, true) } pub(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(); let has_attrs = 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), } } let empty = !has_attrs && blk.stmts.is_empty(); self.bclose_maybe_open(blk.span, empty, close_box); self.ann.post(self, AnnNode::Block(blk)) } /// Print a `let pat = expr` expression. pub(crate) fn print_let(&mut self, pat: &ast::Pat, expr: &ast::Expr) { self.word("let "); self.print_pat(pat); self.space(); self.word_space("="); let npals = || parser::needs_par_as_let_scrutinee(expr.precedence().order()); self.print_expr_cond_paren(expr, Self::cond_needs_par(expr) || npals()) } pub(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_inline_asm(&mut self, asm: &ast::InlineAsm) { enum AsmArg<'a> { Template(String), Operand(&'a InlineAsmOperand), ClobberAbi(Symbol), Options(InlineAsmOptions), } let mut args = vec![AsmArg::Template(InlineAsmTemplatePiece::to_string(&asm.template))]; args.extend(asm.operands.iter().map(|(o, _)| AsmArg::Operand(o))); for (abi, _) in &asm.clobber_abis { args.push(AsmArg::ClobberAbi(*abi)); } if !asm.options.is_empty() { args.push(AsmArg::Options(asm.options)); } 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_symbol(*r, 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 { anon_const } => { s.word("const"); s.space(); s.print_expr(&anon_const.value); } InlineAsmOperand::Sym { sym } => { s.word("sym"); s.space(); if let Some(qself) = &sym.qself { s.print_qpath(&sym.path, qself, true); } else { s.print_path(&sym.path, true, 0); } } } } AsmArg::ClobberAbi(abi) => { s.word("clobber_abi"); s.popen(); s.print_symbol(*abi, ast::StrStyle::Cooked); s.pclose(); } 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"); } if opts.contains(InlineAsmOptions::RAW) { options.push("raw"); } if opts.contains(InlineAsmOptions::MAY_UNWIND) { options.push("may_unwind"); } s.commasep(Inconsistent, &options, |s, &opt| { s.word(opt); }); s.pclose(); } }); self.pclose(); } pub(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(crate) fn print_name(&mut self, name: Symbol) { self.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.word("<"); self.print_type(&qself.ty); if qself.position > 0 { self.space(); self.word_space("as"); let depth = path.segments.len() - qself.position; self.print_path(path, false, depth); } self.word(">"); for item_segment in &path.segments[qself.position..] { self.word("::"); self.print_ident(item_segment.ident); if let Some(ref args) = item_segment.args { self.print_generic_args(args, colons_before_params) } } } pub(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.word("_"), PatKind::Ident(BindingAnnotation(by_ref, mutbl), ident, ref sub) => { if by_ref == ByRef::Yes { self.word_nbsp("ref"); } if mutbl == Mutability::Mut { self.word_nbsp("mut"); } self.print_ident(ident); if let Some(ref p) = *sub { self.space(); self.word_space("@"); self.print_pat(p); } } PatKind::TupleStruct(ref qself, ref path, ref elts) => { if let Some(qself) = qself { self.print_qpath(path, qself, true); } else { 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 qself, ref path, ref fields, etc) => { if let Some(qself) = qself { self.print_qpath(path, qself, true); } else { self.print_path(path, true, 0); } self.nbsp(); self.word("{"); let empty = fields.is_empty() && !etc; if !empty { self.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.word(".."); } if !empty { self.space(); } self.word("}"); } PatKind::Tuple(ref elts) => { self.popen(); self.commasep(Inconsistent, &elts, |s, p| s.print_pat(p)); if elts.len() == 1 { self.word(","); } self.pclose(); } PatKind::Box(ref inner) => { self.word("box "); self.print_pat(inner); } PatKind::Ref(ref inner, mutbl) => { self.word("&"); if mutbl == Mutability::Mut { self.word("mut "); } if let PatKind::Ident(ast::BindingAnnotation::MUT, ..) = inner.kind { self.popen(); self.print_pat(inner); self.pclose(); } else { 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); } match *end_kind { RangeEnd::Included(RangeSyntax::DotDotDot) => self.word("..."), RangeEnd::Included(RangeSyntax::DotDotEq) => self.word("..="), RangeEnd::Excluded => self.word(".."), } if let Some(e) = end { self.print_expr(e); } } PatKind::Slice(ref elts) => { self.word("["); self.commasep(Inconsistent, &elts, |s, p| s.print_pat(p)); self.word("]"); } PatKind::Rest => self.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_explicit_self(&mut self, explicit_self: &ast::ExplicitSelf) { match explicit_self.node { SelfKind::Value(m) => { self.print_mutability(m, false); self.word("self") } SelfKind::Region(ref lt, m) => { self.word("&"); self.print_opt_lifetime(lt); self.print_mutability(m, false); self.word("self") } SelfKind::Explicit(ref typ, m) => { self.print_mutability(m, false); self.word("self"); self.word_space(":"); self.print_type(typ) } } } pub(crate) fn print_asyncness(&mut self, asyncness: ast::Async) { if asyncness.is_async() { self.word_nbsp("async"); } } pub fn print_type_bounds(&mut self, bounds: &[ast::GenericBound]) { let mut first = true; for bound in bounds { if first { first = false; } else { self.nbsp(); self.word_space("+"); } match bound { GenericBound::Trait(tref, modifier) => { if modifier == &TraitBoundModifier::Maybe { self.word("?"); } self.print_poly_trait_ref(tref); } GenericBound::Outlives(lt) => self.print_lifetime(*lt), } } } pub(crate) fn print_lifetime(&mut self, lifetime: ast::Lifetime) { self.print_name(lifetime.ident.name) } pub(crate) fn print_lifetime_bounds(&mut self, bounds: &ast::GenericBounds) { for (i, bound) in bounds.iter().enumerate() { if i != 0 { self.word(" + "); } match bound { ast::GenericBound::Outlives(lt) => self.print_lifetime(*lt), _ => panic!(), } } } pub(crate) fn print_generic_params(&mut self, generic_params: &[ast::GenericParam]) { if generic_params.is_empty() { return; } self.word("<"); self.commasep(Inconsistent, &generic_params, |s, param| { s.print_outer_attributes_inline(¶m.attrs); match param.kind { ast::GenericParamKind::Lifetime => { let lt = ast::Lifetime { id: param.id, ident: param.ident }; s.print_lifetime(lt); if !param.bounds.is_empty() { s.word_nbsp(":"); s.print_lifetime_bounds(¶m.bounds) } } ast::GenericParamKind::Type { ref default } => { s.print_ident(param.ident); if !param.bounds.is_empty() { s.word_nbsp(":"); s.print_type_bounds(¶m.bounds); } if let Some(ref default) = default { s.space(); s.word_space("="); s.print_type(default) } } ast::GenericParamKind::Const { ref ty, kw_span: _, ref default } => { s.word_space("const"); s.print_ident(param.ident); s.space(); s.word_space(":"); s.print_type(ty); if !param.bounds.is_empty() { s.word_nbsp(":"); s.print_type_bounds(¶m.bounds); } if let Some(ref default) = default { s.space(); s.word_space("="); s.print_expr(&default.value); } } } }); self.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"); } } } } pub(crate) fn print_mt(&mut self, mt: &ast::MutTy, print_const: bool) { self.print_mutability(mt.mutbl, print_const); self.print_type(&mt.ty) } pub(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::Empty } else { false }; if !invalid { self.print_pat(&input.pat); self.word(":"); self.space(); } self.print_type(&input.ty); } } } self.end(); } pub(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()); } } pub(crate) fn print_ty_fn( &mut self, ext: ast::Extern, unsafety: ast::Unsafe, decl: &ast::FnDecl, name: Option, generic_params: &[ast::GenericParam], ) { self.ibox(INDENT_UNIT); self.print_formal_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(); } pub(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.word("fn") } pub(crate) fn print_unsafety(&mut self, s: ast::Unsafe) { match s { ast::Unsafe::No => {} ast::Unsafe::Yes(_) => self.word_nbsp("unsafe"), } } pub(crate) fn print_constness(&mut self, s: ast::Const) { match s { ast::Const::No => {} ast::Const::Yes(_) => self.word_nbsp("const"), } } pub(crate) fn print_is_auto(&mut self, s: ast::IsAuto) { match s { ast::IsAuto::Yes => self.word_nbsp("auto"), ast::IsAuto::No => {} } } }