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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-06-07 05:48:48 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-06-07 05:48:48 +0000 |
commit | ef24de24a82fe681581cc130f342363c47c0969a (patch) | |
tree | 0d494f7e1a38b95c92426f58fe6eaa877303a86c /compiler/rustc_ast_pretty/src/pprust/state.rs | |
parent | Releasing progress-linux version 1.74.1+dfsg1-1~progress7.99u1. (diff) | |
download | rustc-ef24de24a82fe681581cc130f342363c47c0969a.tar.xz rustc-ef24de24a82fe681581cc130f342363c47c0969a.zip |
Merging upstream version 1.75.0+dfsg1.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'compiler/rustc_ast_pretty/src/pprust/state.rs')
-rw-r--r-- | compiler/rustc_ast_pretty/src/pprust/state.rs | 74 |
1 files changed, 43 insertions, 31 deletions
diff --git a/compiler/rustc_ast_pretty/src/pprust/state.rs b/compiler/rustc_ast_pretty/src/pprust/state.rs index 8b7e91882..48421ff71 100644 --- a/compiler/rustc_ast_pretty/src/pprust/state.rs +++ b/compiler/rustc_ast_pretty/src/pprust/state.rs @@ -146,37 +146,49 @@ pub fn print_crate<'a>( 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 { - // No space after these tokens, e.g. `x.y`, `$e` - // (The carets point to `prev`.) ^ ^ - if matches!(token.kind, token::Dot | token::Dollar) { - return false; - } - if let token::DocComment(comment_kind, ..) = token.kind { - return comment_kind != CommentKind::Line; - } - } - match tt { - // No space before these tokens, e.g. `foo,`, `println!`, `x.y` - // (The carets point to `token`.) ^ ^ ^ +/// Should two consecutive tokens be printed with a space between them? +/// +/// Note: some old proc macros parse pretty-printed output, so changes here can +/// break old code. For example: +/// - #63896: `#[allow(unused,` must be printed rather than `#[allow(unused ,` +/// - #73345: `#[allow(unused)] must be printed rather than `# [allow(unused)] +/// +fn space_between(tt1: &TokenTree, tt2: &TokenTree) -> bool { + use token::*; + use Delimiter::*; + use TokenTree::Delimited as Del; + use TokenTree::Token as Tok; + + // Each match arm has one or more examples in comments. The default is to + // insert space between adjacent tokens, except for the cases listed in + // this match. + match (tt1, tt2) { + // No space after line doc comments. + (Tok(Token { kind: DocComment(CommentKind::Line, ..), .. }, _), _) => false, + + // `.` + ANYTHING: `x.y`, `tup.0` + // `$` + ANYTHING: `$e` + (Tok(Token { kind: Dot | Dollar, .. }, _), _) => false, + + // ANYTHING + `,`: `foo,` + // ANYTHING + `.`: `x.y`, `tup.0` + // ANYTHING + `!`: `foo! { ... }` // - // FIXME: having `Not` here works well for macro invocations like - // `println!()`, but is bad when `!` means "logical not" or "the never - // type", where the lack of space causes ugliness like this: - // `Fn() ->!`, `x =! y`, `if! x { f(); }`. - TokenTree::Token(token, _) => !matches!(token.kind, token::Comma | token::Not | token::Dot), - // No space before parentheses if preceded by these tokens, e.g. `foo(...)` - TokenTree::Delimited(_, Delimiter::Parenthesis, _) => { - !matches!(prev, TokenTree::Token(Token { kind: token::Ident(..), .. }, _)) - } - // No space before brackets if preceded by these tokens, e.g. `#[...]` - TokenTree::Delimited(_, Delimiter::Bracket, _) => { - !matches!(prev, TokenTree::Token(Token { kind: token::Pound, .. }, _)) - } - TokenTree::Delimited(..) => true, + // FIXME: Incorrect cases: + // - Logical not: `x =! y`, `if! x { f(); }` + // - Never type: `Fn() ->!` + (_, Tok(Token { kind: Comma | Dot | Not, .. }, _)) => false, + + // IDENT + `(`: `f(3)` + // + // FIXME: Incorrect cases: + // - Let: `let(a, b) = (1, 2)` + (Tok(Token { kind: Ident(..), .. }, _), Del(_, Parenthesis, _)) => false, + + // `#` + `[`: `#[attr]` + (Tok(Token { kind: Pound, .. }, _), Del(_, Bracket, _)) => false, + + _ => true, } } @@ -575,7 +587,7 @@ pub trait PrintState<'a>: std::ops::Deref<Target = pp::Printer> + std::ops::Dere 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) { + if space_between(tt, next) { self.space(); } } |