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-rw-r--r--compiler/rustc_ast_pretty/Cargo.toml11
-rw-r--r--compiler/rustc_ast_pretty/src/helpers.rs48
-rw-r--r--compiler/rustc_ast_pretty/src/lib.rs8
-rw-r--r--compiler/rustc_ast_pretty/src/pp.rs451
-rw-r--r--compiler/rustc_ast_pretty/src/pp/convenience.rs94
-rw-r--r--compiler/rustc_ast_pretty/src/pp/ring.rs77
-rw-r--r--compiler/rustc_ast_pretty/src/pprust/mod.rs86
-rw-r--r--compiler/rustc_ast_pretty/src/pprust/state.rs1770
-rw-r--r--compiler/rustc_ast_pretty/src/pprust/state/delimited.rs41
-rw-r--r--compiler/rustc_ast_pretty/src/pprust/state/expr.rs621
-rw-r--r--compiler/rustc_ast_pretty/src/pprust/state/item.rs708
-rw-r--r--compiler/rustc_ast_pretty/src/pprust/tests.rs63
12 files changed, 3978 insertions, 0 deletions
diff --git a/compiler/rustc_ast_pretty/Cargo.toml b/compiler/rustc_ast_pretty/Cargo.toml
new file mode 100644
index 000000000..5ad8714e9
--- /dev/null
+++ b/compiler/rustc_ast_pretty/Cargo.toml
@@ -0,0 +1,11 @@
+[package]
+name = "rustc_ast_pretty"
+version = "0.0.0"
+edition = "2021"
+
+[lib]
+doctest = false
+
+[dependencies]
+rustc_span = { path = "../rustc_span" }
+rustc_ast = { path = "../rustc_ast" }
diff --git a/compiler/rustc_ast_pretty/src/helpers.rs b/compiler/rustc_ast_pretty/src/helpers.rs
new file mode 100644
index 000000000..5ec71cddf
--- /dev/null
+++ b/compiler/rustc_ast_pretty/src/helpers.rs
@@ -0,0 +1,48 @@
+use crate::pp::Printer;
+use std::borrow::Cow;
+
+impl Printer {
+ pub fn word_space<W: Into<Cow<'static, str>>>(&mut self, w: W) {
+ self.word(w);
+ self.space();
+ }
+
+ pub fn popen(&mut self) {
+ self.word("(");
+ }
+
+ pub fn pclose(&mut self) {
+ self.word(")");
+ }
+
+ pub fn hardbreak_if_not_bol(&mut self) {
+ if !self.is_beginning_of_line() {
+ self.hardbreak()
+ }
+ }
+
+ pub fn space_if_not_bol(&mut self) {
+ if !self.is_beginning_of_line() {
+ self.space();
+ }
+ }
+
+ pub fn nbsp(&mut self) {
+ self.word(" ")
+ }
+
+ pub fn word_nbsp<S: Into<Cow<'static, str>>>(&mut self, w: S) {
+ self.word(w);
+ self.nbsp()
+ }
+
+ // Synthesizes a comment that was not textually present in the original
+ // source file.
+ pub fn synth_comment(&mut self, text: impl Into<Cow<'static, str>>) {
+ self.word("/*");
+ self.space();
+ self.word(text);
+ self.space();
+ self.word("*/")
+ }
+}
diff --git a/compiler/rustc_ast_pretty/src/lib.rs b/compiler/rustc_ast_pretty/src/lib.rs
new file mode 100644
index 000000000..79178830b
--- /dev/null
+++ b/compiler/rustc_ast_pretty/src/lib.rs
@@ -0,0 +1,8 @@
+#![feature(associated_type_bounds)]
+#![feature(box_patterns)]
+#![feature(with_negative_coherence)]
+#![recursion_limit = "256"]
+
+mod helpers;
+pub mod pp;
+pub mod pprust;
diff --git a/compiler/rustc_ast_pretty/src/pp.rs b/compiler/rustc_ast_pretty/src/pp.rs
new file mode 100644
index 000000000..c93022308
--- /dev/null
+++ b/compiler/rustc_ast_pretty/src/pp.rs
@@ -0,0 +1,451 @@
+//! This pretty-printer is a direct reimplementation of Philip Karlton's
+//! Mesa pretty-printer, as described in the appendix to
+//! Derek C. Oppen, "Pretty Printing" (1979),
+//! Stanford Computer Science Department STAN-CS-79-770,
+//! <http://i.stanford.edu/pub/cstr/reports/cs/tr/79/770/CS-TR-79-770.pdf>.
+//!
+//! The algorithm's aim is to break a stream into as few lines as possible
+//! while respecting the indentation-consistency requirements of the enclosing
+//! block, and avoiding breaking at silly places on block boundaries, for
+//! example, between "x" and ")" in "x)".
+//!
+//! I am implementing this algorithm because it comes with 20 pages of
+//! documentation explaining its theory, and because it addresses the set of
+//! concerns I've seen other pretty-printers fall down on. Weirdly. Even though
+//! it's 32 years old. What can I say?
+//!
+//! Despite some redundancies and quirks in the way it's implemented in that
+//! paper, I've opted to keep the implementation here as similar as I can,
+//! changing only what was blatantly wrong, a typo, or sufficiently
+//! non-idiomatic rust that it really stuck out.
+//!
+//! In particular you'll see a certain amount of churn related to INTEGER vs.
+//! CARDINAL in the Mesa implementation. Mesa apparently interconverts the two
+//! somewhat readily? In any case, I've used usize for indices-in-buffers and
+//! ints for character-sizes-and-indentation-offsets. This respects the need
+//! for ints to "go negative" while carrying a pending-calculation balance, and
+//! helps differentiate all the numbers flying around internally (slightly).
+//!
+//! I also inverted the indentation arithmetic used in the print stack, since
+//! the Mesa implementation (somewhat randomly) stores the offset on the print
+//! stack in terms of margin-col rather than col itself. I store col.
+//!
+//! I also implemented a small change in the String token, in that I store an
+//! explicit length for the string. For most tokens this is just the length of
+//! the accompanying string. But it's necessary to permit it to differ, for
+//! encoding things that are supposed to "go on their own line" -- certain
+//! classes of comment and blank-line -- where relying on adjacent
+//! hardbreak-like Break tokens with long blankness indication doesn't actually
+//! work. To see why, consider when there is a "thing that should be on its own
+//! line" between two long blocks, say functions. If you put a hardbreak after
+//! each function (or before each) and the breaking algorithm decides to break
+//! there anyways (because the functions themselves are long) you wind up with
+//! extra blank lines. If you don't put hardbreaks you can wind up with the
+//! "thing which should be on its own line" not getting its own line in the
+//! rare case of "really small functions" or such. This re-occurs with comments
+//! and explicit blank lines. So in those cases we use a string with a payload
+//! we want isolated to a line and an explicit length that's huge, surrounded
+//! by two zero-length breaks. The algorithm will try its best to fit it on a
+//! line (which it can't) and so naturally place the content on its own line to
+//! avoid combining it with other lines and making matters even worse.
+//!
+//! # Explanation
+//!
+//! In case you do not have the paper, here is an explanation of what's going
+//! on.
+//!
+//! There is a stream of input tokens flowing through this printer.
+//!
+//! The printer buffers up to 3N tokens inside itself, where N is linewidth.
+//! Yes, linewidth is chars and tokens are multi-char, but in the worst
+//! case every token worth buffering is 1 char long, so it's ok.
+//!
+//! Tokens are String, Break, and Begin/End to delimit blocks.
+//!
+//! Begin tokens can carry an offset, saying "how far to indent when you break
+//! inside here", as well as a flag indicating "consistent" or "inconsistent"
+//! breaking. Consistent breaking means that after the first break, no attempt
+//! will be made to flow subsequent breaks together onto lines. Inconsistent
+//! is the opposite. Inconsistent breaking example would be, say:
+//!
+//! ```ignore (illustrative)
+//! foo(hello, there, good, friends)
+//! ```
+//!
+//! breaking inconsistently to become
+//!
+//! ```ignore (illustrative)
+//! foo(hello, there,
+//! good, friends);
+//! ```
+//!
+//! whereas a consistent breaking would yield:
+//!
+//! ```ignore (illustrative)
+//! foo(hello,
+//! there,
+//! good,
+//! friends);
+//! ```
+//!
+//! That is, in the consistent-break blocks we value vertical alignment
+//! more than the ability to cram stuff onto a line. But in all cases if it
+//! can make a block a one-liner, it'll do so.
+//!
+//! Carrying on with high-level logic:
+//!
+//! The buffered tokens go through a ring-buffer, 'tokens'. The 'left' and
+//! 'right' indices denote the active portion of the ring buffer as well as
+//! describing hypothetical points-in-the-infinite-stream at most 3N tokens
+//! apart (i.e., "not wrapped to ring-buffer boundaries"). The paper will switch
+//! between using 'left' and 'right' terms to denote the wrapped-to-ring-buffer
+//! and point-in-infinite-stream senses freely.
+//!
+//! There is a parallel ring buffer, `size`, that holds the calculated size of
+//! each token. Why calculated? Because for Begin/End pairs, the "size"
+//! includes everything between the pair. That is, the "size" of Begin is
+//! actually the sum of the sizes of everything between Begin and the paired
+//! End that follows. Since that is arbitrarily far in the future, `size` is
+//! being rewritten regularly while the printer runs; in fact most of the
+//! machinery is here to work out `size` entries on the fly (and give up when
+//! they're so obviously over-long that "infinity" is a good enough
+//! approximation for purposes of line breaking).
+//!
+//! The "input side" of the printer is managed as an abstract process called
+//! SCAN, which uses `scan_stack`, to manage calculating `size`. SCAN is, in
+//! other words, the process of calculating 'size' entries.
+//!
+//! The "output side" of the printer is managed by an abstract process called
+//! PRINT, which uses `print_stack`, `margin` and `space` to figure out what to
+//! do with each token/size pair it consumes as it goes. It's trying to consume
+//! the entire buffered window, but can't output anything until the size is >=
+//! 0 (sizes are set to negative while they're pending calculation).
+//!
+//! So SCAN takes input and buffers tokens and pending calculations, while
+//! PRINT gobbles up completed calculations and tokens from the buffer. The
+//! theory is that the two can never get more than 3N tokens apart, because
+//! once there's "obviously" too much data to fit on a line, in a size
+//! calculation, SCAN will write "infinity" to the size and let PRINT consume
+//! it.
+//!
+//! In this implementation (following the paper, again) the SCAN process is the
+//! methods called `Printer::scan_*`, and the 'PRINT' process is the
+//! method called `Printer::print`.
+
+mod convenience;
+mod ring;
+
+use ring::RingBuffer;
+use std::borrow::Cow;
+use std::cmp;
+use std::collections::VecDeque;
+use std::iter;
+
+/// How to break. Described in more detail in the module docs.
+#[derive(Clone, Copy, PartialEq)]
+pub enum Breaks {
+ Consistent,
+ Inconsistent,
+}
+
+#[derive(Clone, Copy, PartialEq)]
+enum IndentStyle {
+ /// Vertically aligned under whatever column this block begins at.
+ ///
+ /// fn demo(arg1: usize,
+ /// arg2: usize) {}
+ Visual,
+ /// Indented relative to the indentation level of the previous line.
+ ///
+ /// fn demo(
+ /// arg1: usize,
+ /// arg2: usize,
+ /// ) {}
+ Block { offset: isize },
+}
+
+#[derive(Clone, Copy, Default, PartialEq)]
+pub struct BreakToken {
+ offset: isize,
+ blank_space: isize,
+ pre_break: Option<char>,
+}
+
+#[derive(Clone, Copy, PartialEq)]
+pub struct BeginToken {
+ indent: IndentStyle,
+ breaks: Breaks,
+}
+
+#[derive(Clone, PartialEq)]
+pub enum Token {
+ // In practice a string token contains either a `&'static str` or a
+ // `String`. `Cow` is overkill for this because we never modify the data,
+ // but it's more convenient than rolling our own more specialized type.
+ String(Cow<'static, str>),
+ Break(BreakToken),
+ Begin(BeginToken),
+ End,
+}
+
+#[derive(Copy, Clone)]
+enum PrintFrame {
+ Fits,
+ Broken { indent: usize, breaks: Breaks },
+}
+
+const SIZE_INFINITY: isize = 0xffff;
+
+/// Target line width.
+const MARGIN: isize = 78;
+/// Every line is allowed at least this much space, even if highly indented.
+const MIN_SPACE: isize = 60;
+
+pub struct Printer {
+ out: String,
+ /// Number of spaces left on line
+ space: isize,
+ /// Ring-buffer of tokens and calculated sizes
+ buf: RingBuffer<BufEntry>,
+ /// Running size of stream "...left"
+ left_total: isize,
+ /// Running size of stream "...right"
+ right_total: isize,
+ /// Pseudo-stack, really a ring too. Holds the
+ /// primary-ring-buffers index of the Begin that started the
+ /// current block, possibly with the most recent Break after that
+ /// Begin (if there is any) on top of it. Stuff is flushed off the
+ /// bottom as it becomes irrelevant due to the primary ring-buffer
+ /// advancing.
+ scan_stack: VecDeque<usize>,
+ /// Stack of blocks-in-progress being flushed by print
+ print_stack: Vec<PrintFrame>,
+ /// Level of indentation of current line
+ indent: usize,
+ /// Buffered indentation to avoid writing trailing whitespace
+ pending_indentation: isize,
+ /// The token most recently popped from the left boundary of the
+ /// ring-buffer for printing
+ last_printed: Option<Token>,
+}
+
+#[derive(Clone)]
+struct BufEntry {
+ token: Token,
+ size: isize,
+}
+
+impl Printer {
+ pub fn new() -> Self {
+ Printer {
+ out: String::new(),
+ space: MARGIN,
+ buf: RingBuffer::new(),
+ left_total: 0,
+ right_total: 0,
+ scan_stack: VecDeque::new(),
+ print_stack: Vec::new(),
+ indent: 0,
+ pending_indentation: 0,
+ last_printed: None,
+ }
+ }
+
+ pub fn last_token(&self) -> Option<&Token> {
+ self.last_token_still_buffered().or_else(|| self.last_printed.as_ref())
+ }
+
+ pub fn last_token_still_buffered(&self) -> Option<&Token> {
+ self.buf.last().map(|last| &last.token)
+ }
+
+ /// Be very careful with this!
+ pub fn replace_last_token_still_buffered(&mut self, token: Token) {
+ self.buf.last_mut().unwrap().token = token;
+ }
+
+ fn scan_eof(&mut self) {
+ if !self.scan_stack.is_empty() {
+ self.check_stack(0);
+ self.advance_left();
+ }
+ }
+
+ fn scan_begin(&mut self, token: BeginToken) {
+ if self.scan_stack.is_empty() {
+ self.left_total = 1;
+ self.right_total = 1;
+ self.buf.clear();
+ }
+ let right = self.buf.push(BufEntry { token: Token::Begin(token), size: -self.right_total });
+ self.scan_stack.push_back(right);
+ }
+
+ fn scan_end(&mut self) {
+ if self.scan_stack.is_empty() {
+ self.print_end();
+ } else {
+ let right = self.buf.push(BufEntry { token: Token::End, size: -1 });
+ self.scan_stack.push_back(right);
+ }
+ }
+
+ fn scan_break(&mut self, token: BreakToken) {
+ if self.scan_stack.is_empty() {
+ self.left_total = 1;
+ self.right_total = 1;
+ self.buf.clear();
+ } else {
+ self.check_stack(0);
+ }
+ let right = self.buf.push(BufEntry { token: Token::Break(token), size: -self.right_total });
+ self.scan_stack.push_back(right);
+ self.right_total += token.blank_space;
+ }
+
+ fn scan_string(&mut self, string: Cow<'static, str>) {
+ if self.scan_stack.is_empty() {
+ self.print_string(&string);
+ } else {
+ let len = string.len() as isize;
+ self.buf.push(BufEntry { token: Token::String(string), size: len });
+ self.right_total += len;
+ self.check_stream();
+ }
+ }
+
+ pub fn offset(&mut self, offset: isize) {
+ if let Some(BufEntry { token: Token::Break(token), .. }) = &mut self.buf.last_mut() {
+ token.offset += offset;
+ }
+ }
+
+ fn check_stream(&mut self) {
+ while self.right_total - self.left_total > self.space {
+ if *self.scan_stack.front().unwrap() == self.buf.index_of_first() {
+ self.scan_stack.pop_front().unwrap();
+ self.buf.first_mut().unwrap().size = SIZE_INFINITY;
+ }
+ self.advance_left();
+ if self.buf.is_empty() {
+ break;
+ }
+ }
+ }
+
+ fn advance_left(&mut self) {
+ while self.buf.first().unwrap().size >= 0 {
+ let left = self.buf.pop_first().unwrap();
+
+ match &left.token {
+ Token::String(string) => {
+ self.left_total += string.len() as isize;
+ self.print_string(string);
+ }
+ Token::Break(token) => {
+ self.left_total += token.blank_space;
+ self.print_break(*token, left.size);
+ }
+ Token::Begin(token) => self.print_begin(*token, left.size),
+ Token::End => self.print_end(),
+ }
+
+ self.last_printed = Some(left.token);
+
+ if self.buf.is_empty() {
+ break;
+ }
+ }
+ }
+
+ fn check_stack(&mut self, mut depth: usize) {
+ while let Some(&index) = self.scan_stack.back() {
+ let mut entry = &mut self.buf[index];
+ match entry.token {
+ Token::Begin(_) => {
+ if depth == 0 {
+ break;
+ }
+ self.scan_stack.pop_back().unwrap();
+ entry.size += self.right_total;
+ depth -= 1;
+ }
+ Token::End => {
+ // paper says + not =, but that makes no sense.
+ self.scan_stack.pop_back().unwrap();
+ entry.size = 1;
+ depth += 1;
+ }
+ _ => {
+ self.scan_stack.pop_back().unwrap();
+ entry.size += self.right_total;
+ if depth == 0 {
+ break;
+ }
+ }
+ }
+ }
+ }
+
+ fn get_top(&self) -> PrintFrame {
+ *self
+ .print_stack
+ .last()
+ .unwrap_or(&PrintFrame::Broken { indent: 0, breaks: Breaks::Inconsistent })
+ }
+
+ fn print_begin(&mut self, token: BeginToken, size: isize) {
+ if size > self.space {
+ self.print_stack.push(PrintFrame::Broken { indent: self.indent, breaks: token.breaks });
+ self.indent = match token.indent {
+ IndentStyle::Block { offset } => {
+ usize::try_from(self.indent as isize + offset).unwrap()
+ }
+ IndentStyle::Visual => (MARGIN - self.space) as usize,
+ };
+ } else {
+ self.print_stack.push(PrintFrame::Fits);
+ }
+ }
+
+ fn print_end(&mut self) {
+ if let PrintFrame::Broken { indent, .. } = self.print_stack.pop().unwrap() {
+ self.indent = indent;
+ }
+ }
+
+ fn print_break(&mut self, token: BreakToken, size: isize) {
+ let fits = match self.get_top() {
+ PrintFrame::Fits => true,
+ PrintFrame::Broken { breaks: Breaks::Consistent, .. } => false,
+ PrintFrame::Broken { breaks: Breaks::Inconsistent, .. } => size <= self.space,
+ };
+ if fits {
+ self.pending_indentation += token.blank_space;
+ self.space -= token.blank_space;
+ } else {
+ if let Some(pre_break) = token.pre_break {
+ self.out.push(pre_break);
+ }
+ self.out.push('\n');
+ let indent = self.indent as isize + token.offset;
+ self.pending_indentation = indent;
+ self.space = cmp::max(MARGIN - indent, MIN_SPACE);
+ }
+ }
+
+ fn print_string(&mut self, string: &str) {
+ // Write the pending indent. A more concise way of doing this would be:
+ //
+ // write!(self.out, "{: >n$}", "", n = self.pending_indentation as usize)?;
+ //
+ // But that is significantly slower. This code is sufficiently hot, and indents can get
+ // sufficiently large, that the difference is significant on some workloads.
+ self.out.reserve(self.pending_indentation as usize);
+ self.out.extend(iter::repeat(' ').take(self.pending_indentation as usize));
+ self.pending_indentation = 0;
+
+ self.out.push_str(string);
+ self.space -= string.len() as isize;
+ }
+}
diff --git a/compiler/rustc_ast_pretty/src/pp/convenience.rs b/compiler/rustc_ast_pretty/src/pp/convenience.rs
new file mode 100644
index 000000000..93310dd45
--- /dev/null
+++ b/compiler/rustc_ast_pretty/src/pp/convenience.rs
@@ -0,0 +1,94 @@
+use crate::pp::{BeginToken, BreakToken, Breaks, IndentStyle, Printer, Token, SIZE_INFINITY};
+use std::borrow::Cow;
+
+impl Printer {
+ /// "raw box"
+ pub fn rbox(&mut self, indent: isize, breaks: Breaks) {
+ self.scan_begin(BeginToken { indent: IndentStyle::Block { offset: indent }, breaks })
+ }
+
+ /// Inconsistent breaking box
+ pub fn ibox(&mut self, indent: isize) {
+ self.rbox(indent, Breaks::Inconsistent)
+ }
+
+ /// Consistent breaking box
+ pub fn cbox(&mut self, indent: isize) {
+ self.rbox(indent, Breaks::Consistent)
+ }
+
+ pub fn visual_align(&mut self) {
+ self.scan_begin(BeginToken { indent: IndentStyle::Visual, breaks: Breaks::Consistent });
+ }
+
+ pub fn break_offset(&mut self, n: usize, off: isize) {
+ self.scan_break(BreakToken {
+ offset: off,
+ blank_space: n as isize,
+ ..BreakToken::default()
+ });
+ }
+
+ pub fn end(&mut self) {
+ self.scan_end()
+ }
+
+ pub fn eof(mut self) -> String {
+ self.scan_eof();
+ self.out
+ }
+
+ pub fn word<S: Into<Cow<'static, str>>>(&mut self, wrd: S) {
+ let string = wrd.into();
+ self.scan_string(string)
+ }
+
+ fn spaces(&mut self, n: usize) {
+ self.break_offset(n, 0)
+ }
+
+ pub fn zerobreak(&mut self) {
+ self.spaces(0)
+ }
+
+ pub fn space(&mut self) {
+ self.spaces(1)
+ }
+
+ pub fn hardbreak(&mut self) {
+ self.spaces(SIZE_INFINITY as usize)
+ }
+
+ pub fn is_beginning_of_line(&self) -> bool {
+ match self.last_token() {
+ Some(last_token) => last_token.is_hardbreak_tok(),
+ None => true,
+ }
+ }
+
+ pub fn hardbreak_tok_offset(off: isize) -> Token {
+ Token::Break(BreakToken {
+ offset: off,
+ blank_space: SIZE_INFINITY,
+ ..BreakToken::default()
+ })
+ }
+
+ pub fn trailing_comma(&mut self) {
+ self.scan_break(BreakToken { pre_break: Some(','), ..BreakToken::default() });
+ }
+
+ pub fn trailing_comma_or_space(&mut self) {
+ self.scan_break(BreakToken {
+ blank_space: 1,
+ pre_break: Some(','),
+ ..BreakToken::default()
+ });
+ }
+}
+
+impl Token {
+ pub fn is_hardbreak_tok(&self) -> bool {
+ *self == Printer::hardbreak_tok_offset(0)
+ }
+}
diff --git a/compiler/rustc_ast_pretty/src/pp/ring.rs b/compiler/rustc_ast_pretty/src/pp/ring.rs
new file mode 100644
index 000000000..8187394fe
--- /dev/null
+++ b/compiler/rustc_ast_pretty/src/pp/ring.rs
@@ -0,0 +1,77 @@
+use std::collections::VecDeque;
+use std::ops::{Index, IndexMut};
+
+/// A view onto a finite range of an infinitely long sequence of T.
+///
+/// The Ts are indexed 0..infinity. A RingBuffer begins as a view of elements
+/// 0..0 (i.e. nothing). The user of the RingBuffer advances its left and right
+/// position independently, although only in the positive direction, and only
+/// with left <= right at all times.
+///
+/// Holding a RingBuffer whose view is elements left..right gives the ability to
+/// use Index and IndexMut to access elements i in the infinitely long queue for
+/// which left <= i < right.
+pub struct RingBuffer<T> {
+ data: VecDeque<T>,
+ // Abstract index of data[0] in the infinitely sized queue.
+ offset: usize,
+}
+
+impl<T> RingBuffer<T> {
+ pub fn new() -> Self {
+ RingBuffer { data: VecDeque::new(), offset: 0 }
+ }
+
+ pub fn is_empty(&self) -> bool {
+ self.data.is_empty()
+ }
+
+ pub fn push(&mut self, value: T) -> usize {
+ let index = self.offset + self.data.len();
+ self.data.push_back(value);
+ index
+ }
+
+ pub fn clear(&mut self) {
+ self.data.clear();
+ }
+
+ pub fn index_of_first(&self) -> usize {
+ self.offset
+ }
+
+ pub fn first(&self) -> Option<&T> {
+ self.data.front()
+ }
+
+ pub fn first_mut(&mut self) -> Option<&mut T> {
+ self.data.front_mut()
+ }
+
+ pub fn pop_first(&mut self) -> Option<T> {
+ let first = self.data.pop_front()?;
+ self.offset += 1;
+ Some(first)
+ }
+
+ pub fn last(&self) -> Option<&T> {
+ self.data.back()
+ }
+
+ pub fn last_mut(&mut self) -> Option<&mut T> {
+ self.data.back_mut()
+ }
+}
+
+impl<T> Index<usize> for RingBuffer<T> {
+ type Output = T;
+ fn index(&self, index: usize) -> &Self::Output {
+ &self.data[index.checked_sub(self.offset).unwrap()]
+ }
+}
+
+impl<T> IndexMut<usize> for RingBuffer<T> {
+ fn index_mut(&mut self, index: usize) -> &mut Self::Output {
+ &mut self.data[index.checked_sub(self.offset).unwrap()]
+ }
+}
diff --git a/compiler/rustc_ast_pretty/src/pprust/mod.rs b/compiler/rustc_ast_pretty/src/pprust/mod.rs
new file mode 100644
index 000000000..ac9e7d06c
--- /dev/null
+++ b/compiler/rustc_ast_pretty/src/pprust/mod.rs
@@ -0,0 +1,86 @@
+#[cfg(test)]
+mod tests;
+
+pub mod state;
+pub use state::{print_crate, AnnNode, Comments, PpAnn, PrintState, State};
+
+use rustc_ast as ast;
+use rustc_ast::token::{Nonterminal, Token, TokenKind};
+use rustc_ast::tokenstream::{TokenStream, TokenTree};
+
+use std::borrow::Cow;
+
+pub fn nonterminal_to_string(nt: &Nonterminal) -> String {
+ State::new().nonterminal_to_string(nt)
+}
+
+/// Print the token kind precisely, without converting `$crate` into its respective crate name.
+pub fn token_kind_to_string(tok: &TokenKind) -> Cow<'static, str> {
+ State::new().token_kind_to_string(tok)
+}
+
+/// Print the token precisely, without converting `$crate` into its respective crate name.
+pub fn token_to_string(token: &Token) -> Cow<'static, str> {
+ State::new().token_to_string(token)
+}
+
+pub fn ty_to_string(ty: &ast::Ty) -> String {
+ State::new().ty_to_string(ty)
+}
+
+pub fn bounds_to_string(bounds: &[ast::GenericBound]) -> String {
+ State::new().bounds_to_string(bounds)
+}
+
+pub fn pat_to_string(pat: &ast::Pat) -> String {
+ State::new().pat_to_string(pat)
+}
+
+pub fn expr_to_string(e: &ast::Expr) -> String {
+ State::new().expr_to_string(e)
+}
+
+pub fn tt_to_string(tt: &TokenTree) -> String {
+ State::new().tt_to_string(tt)
+}
+
+pub fn tts_to_string(tokens: &TokenStream) -> String {
+ State::new().tts_to_string(tokens)
+}
+
+pub fn item_to_string(i: &ast::Item) -> String {
+ State::new().item_to_string(i)
+}
+
+pub fn path_to_string(p: &ast::Path) -> String {
+ State::new().path_to_string(p)
+}
+
+pub fn path_segment_to_string(p: &ast::PathSegment) -> String {
+ State::new().path_segment_to_string(p)
+}
+
+pub fn vis_to_string(v: &ast::Visibility) -> String {
+ State::new().vis_to_string(v)
+}
+
+pub fn meta_list_item_to_string(li: &ast::NestedMetaItem) -> String {
+ State::new().meta_list_item_to_string(li)
+}
+
+pub fn attribute_to_string(attr: &ast::Attribute) -> String {
+ State::new().attribute_to_string(attr)
+}
+
+pub fn to_string(f: impl FnOnce(&mut State<'_>)) -> String {
+ State::to_string(f)
+}
+
+pub fn crate_to_string_for_macros(krate: &ast::Crate) -> String {
+ State::to_string(|s| {
+ s.print_inner_attributes(&krate.attrs);
+ for item in &krate.items {
+ s.print_item(item);
+ }
+ })
+}
diff --git a/compiler/rustc_ast_pretty/src/pprust/state.rs b/compiler/rustc_ast_pretty/src/pprust/state.rs
new file mode 100644
index 000000000..5eb7bf634
--- /dev/null
+++ b/compiler/rustc_ast_pretty/src/pprust/state.rs
@@ -0,0 +1,1770 @@
+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, PatKind, RangeEnd, RangeSyntax};
+use rustc_ast::{attr, 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 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<Comment>,
+ 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<Comment> {
+ self.comments.get(self.current).cloned()
+ }
+
+ pub fn trailing_comment(
+ &self,
+ span: rustc_span::Span,
+ next_pos: Option<BytePos>,
+ ) -> Option<Comment> {
+ 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<Comments<'a>>,
+ 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,
+) -> 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(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_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<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) -> 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<Comment> {
+ self.comments().as_mut().and_then(|c| c.next())
+ }
+
+ 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);
+ }
+ }
+ }
+
+ 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.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 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_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<MacHeader<'_>>,
+ has_bang: bool,
+ ident: Option<Ident>,
+ delim: Option<Delimiter>,
+ 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(),
+ &macro_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<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(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<Span>,
+ ) -> 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 => "$".into(),
+ token::Question => "?".into(),
+ token::SingleQuote => "'".into(),
+
+ /* Literals */
+ token::Literal(lit) => literal_to_string(lit).into(),
+
+ /* Name components */
+ token::Ident(s, is_raw) => {
+ IdentPrinter::new(s, is_raw, convert_dollar_crate).to_string().into()
+ }
+ token::Lifetime(s) => s.to_string().into(),
+
+ /* Other */
+ token::DocComment(comment_kind, attr_style, data) => {
+ doc_comment_to_string(comment_kind, attr_style, data).into()
+ }
+ token::Eof => "<eof>".into(),
+
+ token::Interpolated(ref nt) => self.nonterminal_to_string(nt).into(),
+ }
+ }
+
+ /// Print the token precisely, without converting `$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<Comments<'a>> {
+ &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<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.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<ast::Expr>]) {
+ self.commasep_cmnt(b, exprs, |s, e| s.print_expr(e), |e| e.span)
+ }
+
+ 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::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(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.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 == ast::Mutability::Mut {
+ self.word("mut ");
+ }
+ if let PatKind::Ident(ast::BindingMode::ByValue(ast::Mutability::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(&param.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(&param.bounds)
+ }
+ }
+ ast::GenericParamKind::Type { ref default } => {
+ s.print_ident(param.ident);
+ if !param.bounds.is_empty() {
+ s.word_nbsp(":");
+ s.print_type_bounds(&param.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(&param.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<Ident>,
+ 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 => {}
+ }
+ }
+}
diff --git a/compiler/rustc_ast_pretty/src/pprust/state/delimited.rs b/compiler/rustc_ast_pretty/src/pprust/state/delimited.rs
new file mode 100644
index 000000000..fe0640baa
--- /dev/null
+++ b/compiler/rustc_ast_pretty/src/pprust/state/delimited.rs
@@ -0,0 +1,41 @@
+use std::iter::Peekable;
+use std::mem;
+use std::ops::Deref;
+
+pub struct Delimited<I: Iterator> {
+ is_first: bool,
+ iter: Peekable<I>,
+}
+
+pub trait IterDelimited: Iterator + Sized {
+ fn delimited(self) -> Delimited<Self> {
+ Delimited { is_first: true, iter: self.peekable() }
+ }
+}
+
+impl<I: Iterator> IterDelimited for I {}
+
+pub struct IteratorItem<T> {
+ value: T,
+ pub is_first: bool,
+ pub is_last: bool,
+}
+
+impl<I: Iterator> Iterator for Delimited<I> {
+ type Item = IteratorItem<I::Item>;
+
+ fn next(&mut self) -> Option<Self::Item> {
+ let value = self.iter.next()?;
+ let is_first = mem::replace(&mut self.is_first, false);
+ let is_last = self.iter.peek().is_none();
+ Some(IteratorItem { value, is_first, is_last })
+ }
+}
+
+impl<T> Deref for IteratorItem<T> {
+ type Target = T;
+
+ fn deref(&self) -> &Self::Target {
+ &self.value
+ }
+}
diff --git a/compiler/rustc_ast_pretty/src/pprust/state/expr.rs b/compiler/rustc_ast_pretty/src/pprust/state/expr.rs
new file mode 100644
index 000000000..ead38caee
--- /dev/null
+++ b/compiler/rustc_ast_pretty/src/pprust/state/expr.rs
@@ -0,0 +1,621 @@
+use crate::pp::Breaks::Inconsistent;
+use crate::pprust::state::{AnnNode, IterDelimited, PrintState, State, INDENT_UNIT};
+
+use rustc_ast::ptr::P;
+use rustc_ast::util::parser::{self, AssocOp, Fixity};
+use rustc_ast::{self as ast, BlockCheckMode};
+
+impl<'a> State<'a> {
+ 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.word(" else if ");
+ self.print_expr_as_cond(i);
+ self.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.word(" else ");
+ self.print_block(b)
+ }
+ // Constraints would be great here!
+ _ => {
+ panic!("print_if saw if with weird alternative");
+ }
+ }
+ }
+ }
+
+ 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.space();
+ self.print_block(blk);
+ self.print_else(elseopt)
+ }
+
+ fn print_call_post(&mut self, args: &[P<ast::Expr>]) {
+ self.popen();
+ self.commasep_exprs(Inconsistent, args);
+ self.pclose()
+ }
+
+ 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 { ... }`.
+ fn print_expr_as_cond(&mut self, expr: &ast::Expr) {
+ self.print_expr_cond_paren(expr, Self::cond_needs_par(expr))
+ }
+
+ // Does `expr` need parentheses when printed in a condition position?
+ //
+ // These cases need parens due to the parse error observed in #26461: `if return {}`
+ // parses as the erroneous construct `if (return {})`, not `if (return) {}`.
+ pub(super) fn cond_needs_par(expr: &ast::Expr) -> bool {
+ match expr.kind {
+ ast::ExprKind::Break(..)
+ | ast::ExprKind::Closure(..)
+ | ast::ExprKind::Ret(..)
+ | ast::ExprKind::Yeet(..) => true,
+ _ => parser::contains_exterior_struct_lit(expr),
+ }
+ }
+
+ /// Prints `expr` or `(expr)` when `needs_par` holds.
+ pub(super) 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>]) {
+ self.ibox(INDENT_UNIT);
+ self.word("[");
+ self.commasep_exprs(Inconsistent, exprs);
+ self.word("]");
+ self.end();
+ }
+
+ pub(super) fn print_expr_anon_const(
+ &mut self,
+ expr: &ast::AnonConst,
+ attrs: &[ast::Attribute],
+ ) {
+ self.ibox(INDENT_UNIT);
+ self.word("const");
+ self.nbsp();
+ if let ast::ExprKind::Block(block, None) = &expr.value.kind {
+ self.cbox(0);
+ self.ibox(0);
+ self.print_block_with_attrs(block, attrs);
+ } else {
+ self.print_expr(&expr.value);
+ }
+ self.end();
+ }
+
+ fn print_expr_repeat(&mut self, element: &ast::Expr, count: &ast::AnonConst) {
+ self.ibox(INDENT_UNIT);
+ self.word("[");
+ self.print_expr(element);
+ self.word_space(";");
+ self.print_expr(&count.value);
+ self.word("]");
+ self.end();
+ }
+
+ fn print_expr_struct(
+ &mut self,
+ qself: &Option<ast::QSelf>,
+ path: &ast::Path,
+ fields: &[ast::ExprField],
+ rest: &ast::StructRest,
+ ) {
+ if let Some(qself) = qself {
+ self.print_qpath(path, qself, true);
+ } else {
+ self.print_path(path, true, 0);
+ }
+ self.nbsp();
+ self.word("{");
+ let has_rest = match rest {
+ ast::StructRest::Base(_) | ast::StructRest::Rest(_) => true,
+ ast::StructRest::None => false,
+ };
+ if fields.is_empty() && !has_rest {
+ self.word("}");
+ return;
+ }
+ self.cbox(0);
+ for field in fields.iter().delimited() {
+ self.maybe_print_comment(field.span.hi());
+ self.print_outer_attributes(&field.attrs);
+ if field.is_first {
+ self.space_if_not_bol();
+ }
+ if !field.is_shorthand {
+ self.print_ident(field.ident);
+ self.word_nbsp(":");
+ }
+ self.print_expr(&field.expr);
+ if !field.is_last || has_rest {
+ self.word_space(",");
+ } else {
+ self.trailing_comma_or_space();
+ }
+ }
+ if has_rest {
+ if fields.is_empty() {
+ self.space();
+ }
+ self.word("..");
+ if let ast::StructRest::Base(expr) = rest {
+ self.print_expr(expr);
+ }
+ self.space();
+ }
+ self.offset(-INDENT_UNIT);
+ self.end();
+ self.word("}");
+ }
+
+ fn print_expr_tup(&mut self, exprs: &[P<ast::Expr>]) {
+ self.popen();
+ self.commasep_exprs(Inconsistent, exprs);
+ if exprs.len() == 1 {
+ self.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.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.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.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.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)
+ }
+
+ pub(super) 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);
+ }
+ ast::ExprKind::ConstBlock(ref anon_const) => {
+ self.print_expr_anon_const(anon_const, attrs);
+ }
+ ast::ExprKind::Repeat(ref element, ref count) => {
+ self.print_expr_repeat(element, count);
+ }
+ ast::ExprKind::Struct(ref se) => {
+ self.print_expr_struct(&se.qself, &se.path, &se.fields, &se.rest);
+ }
+ ast::ExprKind::Tup(ref exprs) => {
+ self.print_expr_tup(exprs);
+ }
+ 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.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.cbox(0);
+ self.ibox(0);
+ self.word_nbsp("while");
+ self.print_expr_as_cond(test);
+ self.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.cbox(0);
+ self.ibox(0);
+ self.word_nbsp("for");
+ self.print_pat(pat);
+ self.space();
+ self.word_space("in");
+ self.print_expr_as_cond(iter);
+ self.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.cbox(0);
+ self.ibox(0);
+ self.word_nbsp("loop");
+ self.print_block_with_attrs(blk, attrs);
+ }
+ ast::ExprKind::Match(ref expr, ref arms) => {
+ self.cbox(0);
+ self.ibox(0);
+ self.word_nbsp("match");
+ self.print_expr_as_cond(expr);
+ self.space();
+ self.bopen();
+ self.print_inner_attributes_no_trailing_hardbreak(attrs);
+ for arm in arms {
+ self.print_arm(arm);
+ }
+ let empty = attrs.is_empty() && arms.is_empty();
+ self.bclose(expr.span, empty);
+ }
+ ast::ExprKind::Closure(
+ ref binder,
+ capture_clause,
+ asyncness,
+ movability,
+ ref decl,
+ ref body,
+ _,
+ ) => {
+ self.print_closure_binder(binder);
+ self.print_movability(movability);
+ self.print_asyncness(asyncness);
+ self.print_capture_clause(capture_clause);
+
+ self.print_fn_params_and_ret(decl, true);
+ self.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(0);
+ // 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);
+ // cbox/ibox in analogy to the `ExprKind::Block` arm above
+ self.cbox(0);
+ 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.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.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.space();
+ self.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.word(".");
+ self.print_ident(ident);
+ }
+ ast::ExprKind::Index(ref expr, ref index) => {
+ self.print_expr_maybe_paren(expr, parser::PREC_POSTFIX);
+ self.word("[");
+ self.print_expr(index);
+ self.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.word("..");
+ } else {
+ self.word("..=");
+ }
+ if let Some(ref e) = *end {
+ self.print_expr_maybe_paren(e, fake_prec);
+ }
+ }
+ ast::ExprKind::Underscore => self.word("_"),
+ 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.word("break");
+ if let Some(label) = opt_label {
+ self.space();
+ self.print_ident(label.ident);
+ }
+ if let Some(ref expr) = *opt_expr {
+ self.space();
+ self.print_expr_maybe_paren(expr, parser::PREC_JUMP);
+ }
+ }
+ ast::ExprKind::Continue(opt_label) => {
+ self.word("continue");
+ if let Some(label) = opt_label {
+ self.space();
+ self.print_ident(label.ident);
+ }
+ }
+ ast::ExprKind::Ret(ref result) => {
+ self.word("return");
+ if let Some(ref expr) = *result {
+ self.word(" ");
+ self.print_expr_maybe_paren(expr, parser::PREC_JUMP);
+ }
+ }
+ ast::ExprKind::Yeet(ref result) => {
+ self.word("do");
+ self.word(" ");
+ self.word("yeet");
+ if let Some(ref expr) = *result {
+ self.word(" ");
+ self.print_expr_maybe_paren(expr, parser::PREC_JUMP);
+ }
+ }
+ ast::ExprKind::InlineAsm(ref a) => {
+ self.word("asm!");
+ self.print_inline_asm(a);
+ }
+ ast::ExprKind::MacCall(ref m) => self.print_mac(m),
+ ast::ExprKind::Paren(ref e) => {
+ self.popen();
+ self.print_expr(e);
+ self.pclose();
+ }
+ ast::ExprKind::Yield(ref e) => {
+ self.word("yield");
+
+ if let Some(ref expr) = *e {
+ self.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.word("?")
+ }
+ ast::ExprKind::TryBlock(ref blk) => {
+ self.cbox(0);
+ self.ibox(0);
+ self.word_nbsp("try");
+ self.print_block_with_attrs(blk, attrs)
+ }
+ ast::ExprKind::Err => {
+ self.popen();
+ self.word("/*ERROR*/");
+ self.pclose()
+ }
+ }
+ self.ann.post(self, AnnNode::Expr(expr));
+ self.end();
+ }
+
+ 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.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.space();
+ if let Some(ref e) = arm.guard {
+ self.word_space("if");
+ self.print_expr(e);
+ self.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.word(",");
+ }
+ }
+ _ => {
+ self.end(); // Close the ibox for the pattern.
+ self.print_expr(&arm.body);
+ self.word(",");
+ }
+ }
+ self.end(); // Close enclosing cbox.
+ }
+
+ fn print_closure_binder(&mut self, binder: &ast::ClosureBinder) {
+ match binder {
+ ast::ClosureBinder::NotPresent => {}
+ ast::ClosureBinder::For { generic_params, .. } => {
+ self.print_formal_generic_params(&generic_params)
+ }
+ }
+ }
+
+ fn print_movability(&mut self, movability: ast::Movability) {
+ match movability {
+ ast::Movability::Static => self.word_space("static"),
+ ast::Movability::Movable => {}
+ }
+ }
+
+ fn print_capture_clause(&mut self, capture_clause: ast::CaptureBy) {
+ match capture_clause {
+ ast::CaptureBy::Value => self.word_space("move"),
+ ast::CaptureBy::Ref => {}
+ }
+ }
+}
diff --git a/compiler/rustc_ast_pretty/src/pprust/state/item.rs b/compiler/rustc_ast_pretty/src/pprust/state/item.rs
new file mode 100644
index 000000000..f1caf22f3
--- /dev/null
+++ b/compiler/rustc_ast_pretty/src/pprust/state/item.rs
@@ -0,0 +1,708 @@
+use crate::pp::Breaks::Inconsistent;
+use crate::pprust::state::delimited::IterDelimited;
+use crate::pprust::state::{AnnNode, PrintState, State, INDENT_UNIT};
+
+use rustc_ast as ast;
+use rustc_ast::GenericBound;
+use rustc_ast::ModKind;
+use rustc_span::symbol::Ident;
+
+fn visibility_qualified(vis: &ast::Visibility, s: &str) -> String {
+ format!("{}{}", State::to_string(|s| s.print_visibility(vis)), s)
+}
+
+impl<'a> State<'a> {
+ fn print_foreign_mod(&mut self, nmod: &ast::ForeignMod, attrs: &[ast::Attribute]) {
+ self.print_inner_attributes(attrs);
+ for item in &nmod.items {
+ self.print_foreign_item(item);
+ }
+ }
+
+ pub(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(box ast::Fn { defaultness, sig, generics, body }) => {
+ self.print_fn_full(sig, ident, generics, vis, *defaultness, 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(box ast::TyAlias {
+ defaultness,
+ generics,
+ where_clauses,
+ where_predicates_split,
+ bounds,
+ ty,
+ }) => {
+ self.print_associated_type(
+ ident,
+ generics,
+ *where_clauses,
+ *where_predicates_split,
+ bounds,
+ ty.as_deref(),
+ vis,
+ *defaultness,
+ );
+ }
+ ast::ForeignItemKind::MacCall(m) => {
+ self.print_mac(m);
+ if m.args.need_semicolon() {
+ self.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);
+ if body.is_some() {
+ self.space();
+ }
+ self.end(); // end the head-ibox
+ if let Some(body) = body {
+ self.word_space("=");
+ self.print_expr(body);
+ }
+ self.word(";");
+ self.end(); // end the outer cbox
+ }
+
+ fn print_associated_type(
+ &mut self,
+ ident: Ident,
+ generics: &ast::Generics,
+ where_clauses: (ast::TyAliasWhereClause, ast::TyAliasWhereClause),
+ where_predicates_split: usize,
+ bounds: &ast::GenericBounds,
+ ty: Option<&ast::Ty>,
+ vis: &ast::Visibility,
+ defaultness: ast::Defaultness,
+ ) {
+ let (before_predicates, after_predicates) =
+ generics.where_clause.predicates.split_at(where_predicates_split);
+ self.head("");
+ self.print_visibility(vis);
+ self.print_defaultness(defaultness);
+ self.word_space("type");
+ self.print_ident(ident);
+ self.print_generic_params(&generics.params);
+ if !bounds.is_empty() {
+ self.word_nbsp(":");
+ self.print_type_bounds(bounds);
+ }
+ self.print_where_clause_parts(where_clauses.0.0, before_predicates);
+ if let Some(ty) = ty {
+ self.space();
+ self.word_space("=");
+ self.print_type(ty);
+ }
+ self.print_where_clause_parts(where_clauses.1.0, after_predicates);
+ self.word(";");
+ self.end(); // end inner head-block
+ self.end(); // end outer head-block
+ }
+
+ /// Pretty-prints an item.
+ pub(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.space();
+ self.word("as");
+ self.space();
+ }
+ self.print_ident(item.ident);
+ self.word(";");
+ self.end(); // end inner head-block
+ self.end(); // end outer head-block
+ }
+ ast::ItemKind::Use(ref tree) => {
+ self.print_visibility(&item.vis);
+ self.word_nbsp("use");
+ self.print_use_tree(tree);
+ self.word(";");
+ }
+ 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(box ast::Fn { defaultness, ref sig, ref generics, ref body }) => {
+ let body = body.as_deref();
+ self.print_fn_full(
+ sig,
+ item.ident,
+ generics,
+ &item.vis,
+ defaultness,
+ body,
+ &item.attrs,
+ );
+ }
+ ast::ItemKind::Mod(unsafety, ref mod_kind) => {
+ self.head(Self::to_string(|s| {
+ s.print_visibility(&item.vis);
+ s.print_unsafety(unsafety);
+ s.word("mod");
+ }));
+ self.print_ident(item.ident);
+
+ match mod_kind {
+ ModKind::Loaded(items, ..) => {
+ self.nbsp();
+ self.bopen();
+ self.print_inner_attributes(&item.attrs);
+ for item in items {
+ self.print_item(item);
+ }
+ let empty = item.attrs.is_empty() && items.is_empty();
+ self.bclose(item.span, empty);
+ }
+ ModKind::Unloaded => {
+ self.word(";");
+ self.end(); // end inner head-block
+ self.end(); // end outer head-block
+ }
+ }
+ }
+ ast::ItemKind::ForeignMod(ref nmod) => {
+ self.head(Self::to_string(|s| {
+ s.print_unsafety(nmod.unsafety);
+ s.word("extern");
+ }));
+ if let Some(abi) = nmod.abi {
+ self.print_literal(&abi.as_lit());
+ self.nbsp();
+ }
+ self.bopen();
+ self.print_foreign_mod(nmod, &item.attrs);
+ let empty = item.attrs.is_empty() && nmod.items.is_empty();
+ self.bclose(item.span, empty);
+ }
+ ast::ItemKind::GlobalAsm(ref asm) => {
+ self.head(visibility_qualified(&item.vis, "global_asm!"));
+ self.print_inline_asm(asm);
+ self.end();
+ }
+ ast::ItemKind::TyAlias(box ast::TyAlias {
+ defaultness,
+ ref generics,
+ where_clauses,
+ where_predicates_split,
+ ref bounds,
+ ref ty,
+ }) => {
+ let ty = ty.as_deref();
+ self.print_associated_type(
+ item.ident,
+ generics,
+ where_clauses,
+ where_predicates_split,
+ bounds,
+ ty,
+ &item.vis,
+ defaultness,
+ );
+ }
+ 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(box ast::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("impl");
+
+ if generics.params.is_empty() {
+ self.nbsp();
+ } else {
+ self.print_generic_params(&generics.params);
+ self.space();
+ }
+
+ self.print_constness(constness);
+
+ if let ast::ImplPolarity::Negative(_) = polarity {
+ self.word("!");
+ }
+
+ if let Some(ref t) = *of_trait {
+ self.print_trait_ref(t);
+ self.space();
+ self.word_space("for");
+ }
+
+ self.print_type(self_ty);
+ self.print_where_clause(&generics.where_clause);
+
+ self.space();
+ self.bopen();
+ self.print_inner_attributes(&item.attrs);
+ for impl_item in items {
+ self.print_assoc_item(impl_item);
+ }
+ let empty = item.attrs.is_empty() && items.is_empty();
+ self.bclose(item.span, empty);
+ }
+ ast::ItemKind::Trait(box ast::Trait {
+ is_auto,
+ unsafety,
+ ref generics,
+ ref bounds,
+ ref 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.space();
+ self.word_space("for ?");
+ self.print_trait_ref(&ptr.trait_ref);
+ } else {
+ real_bounds.push(b.clone());
+ }
+ }
+ if !real_bounds.is_empty() {
+ self.word_nbsp(":");
+ self.print_type_bounds(&real_bounds);
+ }
+ self.print_where_clause(&generics.where_clause);
+ self.word(" ");
+ self.bopen();
+ self.print_inner_attributes(&item.attrs);
+ for trait_item in items {
+ self.print_assoc_item(trait_item);
+ }
+ let empty = item.attrs.is_empty() && items.is_empty();
+ self.bclose(item.span, empty);
+ }
+ ast::ItemKind::TraitAlias(ref generics, ref bounds) => {
+ self.head(visibility_qualified(&item.vis, "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.space();
+ self.word_space("for ?");
+ self.print_trait_ref(&ptr.trait_ref);
+ } else {
+ real_bounds.push(b.clone());
+ }
+ }
+ self.nbsp();
+ if !real_bounds.is_empty() {
+ self.word_nbsp("=");
+ self.print_type_bounds(&real_bounds);
+ }
+ self.print_where_clause(&generics.where_clause);
+ self.word(";");
+ self.end(); // end inner head-block
+ self.end(); // end outer head-block
+ }
+ ast::ItemKind::MacCall(ref mac) => {
+ self.print_mac(mac);
+ if mac.args.need_semicolon() {
+ self.word(";");
+ }
+ }
+ ast::ItemKind::MacroDef(ref macro_def) => {
+ self.print_mac_def(macro_def, &item.ident, item.span, |state| {
+ state.print_visibility(&item.vis)
+ });
+ }
+ }
+ self.ann.post(self, AnnNode::Item(item))
+ }
+
+ 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.space();
+ self.print_variants(&enum_definition.variants, span)
+ }
+
+ 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(0);
+ self.print_variant(v);
+ self.word(",");
+ self.end();
+ self.maybe_print_trailing_comment(v.span, None);
+ }
+ let empty = variants.is_empty();
+ self.bclose(span, empty)
+ }
+
+ pub(crate) fn print_visibility(&mut self, vis: &ast::Visibility) {
+ match vis.kind {
+ ast::VisibilityKind::Public => self.word_nbsp("pub"),
+ ast::VisibilityKind::Restricted { ref path, .. } => {
+ let path = Self::to_string(|s| s.print_path(path, false, 0));
+ if path == "crate" || path == "self" || path == "super" {
+ self.word_nbsp(format!("pub({})", path))
+ } else {
+ self.word_nbsp(format!("pub(in {})", path))
+ }
+ }
+ ast::VisibilityKind::Inherited => {}
+ }
+ }
+
+ fn print_defaultness(&mut self, defaultness: ast::Defaultness) {
+ if let ast::Defaultness::Default(_) = defaultness {
+ self.word_nbsp("default");
+ }
+ }
+
+ fn print_record_struct_body(&mut self, fields: &[ast::FieldDef], span: rustc_span::Span) {
+ self.nbsp();
+ self.bopen();
+
+ let empty = fields.is_empty();
+ if !empty {
+ self.hardbreak_if_not_bol();
+
+ for field in 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.word(",");
+ }
+ }
+
+ self.bclose(span, empty);
+ }
+
+ 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.word(";");
+ }
+ self.end();
+ self.end(); // Close the outer-box.
+ }
+ ast::VariantData::Struct(ref fields, ..) => {
+ self.print_where_clause(&generics.where_clause);
+ self.print_record_struct_body(fields, span);
+ }
+ }
+ }
+
+ pub(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.space();
+ self.word_space("=");
+ self.print_expr(&d.value)
+ }
+ }
+
+ pub(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(box ast::Fn { defaultness, sig, generics, body }) => {
+ self.print_fn_full(sig, ident, generics, vis, *defaultness, 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(box ast::TyAlias {
+ defaultness,
+ generics,
+ where_clauses,
+ where_predicates_split,
+ bounds,
+ ty,
+ }) => {
+ self.print_associated_type(
+ ident,
+ generics,
+ *where_clauses,
+ *where_predicates_split,
+ bounds,
+ ty.as_deref(),
+ vis,
+ *defaultness,
+ );
+ }
+ ast::AssocItemKind::MacCall(m) => {
+ self.print_mac(m);
+ if m.args.need_semicolon() {
+ self.word(";");
+ }
+ }
+ }
+ self.ann.post(self, AnnNode::SubItem(id))
+ }
+
+ 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.word(";");
+ }
+ }
+
+ pub(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)
+ }
+
+ pub(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)
+ }
+
+ fn print_where_clause(&mut self, where_clause: &ast::WhereClause) {
+ self.print_where_clause_parts(where_clause.has_where_token, &where_clause.predicates);
+ }
+
+ pub(crate) fn print_where_clause_parts(
+ &mut self,
+ has_where_token: bool,
+ predicates: &[ast::WherePredicate],
+ ) {
+ if predicates.is_empty() && !has_where_token {
+ return;
+ }
+
+ self.space();
+ self.word_space("where");
+
+ for (i, predicate) in predicates.iter().enumerate() {
+ if i != 0 {
+ self.word_space(",");
+ }
+
+ self.print_where_predicate(predicate);
+ }
+ }
+
+ pub fn print_where_predicate(&mut self, predicate: &ast::WherePredicate) {
+ match predicate {
+ ast::WherePredicate::BoundPredicate(ast::WhereBoundPredicate {
+ bound_generic_params,
+ bounded_ty,
+ bounds,
+ ..
+ }) => {
+ self.print_formal_generic_params(bound_generic_params);
+ self.print_type(bounded_ty);
+ self.word(":");
+ if !bounds.is_empty() {
+ self.nbsp();
+ self.print_type_bounds(bounds);
+ }
+ }
+ ast::WherePredicate::RegionPredicate(ast::WhereRegionPredicate {
+ lifetime,
+ bounds,
+ ..
+ }) => {
+ self.print_lifetime(*lifetime);
+ self.word(":");
+ if !bounds.is_empty() {
+ self.nbsp();
+ self.print_lifetime_bounds(bounds);
+ }
+ }
+ ast::WherePredicate::EqPredicate(ast::WhereEqPredicate { lhs_ty, rhs_ty, .. }) => {
+ self.print_type(lhs_ty);
+ self.space();
+ self.word_space("=");
+ self.print_type(rhs_ty);
+ }
+ }
+ }
+
+ 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.nbsp();
+ self.word_nbsp("as");
+ self.print_ident(rename);
+ }
+ }
+ ast::UseTreeKind::Glob => {
+ if !tree.prefix.segments.is_empty() {
+ self.print_path(&tree.prefix, false, 0);
+ self.word("::");
+ }
+ self.word("*");
+ }
+ ast::UseTreeKind::Nested(ref items) => {
+ if !tree.prefix.segments.is_empty() {
+ self.print_path(&tree.prefix, false, 0);
+ self.word("::");
+ }
+ if items.is_empty() {
+ self.word("{}");
+ } else if items.len() == 1 {
+ self.print_use_tree(&items[0].0);
+ } else {
+ self.cbox(INDENT_UNIT);
+ self.word("{");
+ self.zerobreak();
+ self.ibox(0);
+ for use_tree in items.iter().delimited() {
+ self.print_use_tree(&use_tree.0);
+ if !use_tree.is_last {
+ self.word(",");
+ if let ast::UseTreeKind::Nested(_) = use_tree.0.kind {
+ self.hardbreak();
+ } else {
+ self.space();
+ }
+ }
+ }
+ self.end();
+ self.trailing_comma();
+ self.offset(-INDENT_UNIT);
+ self.word("}");
+ self.end();
+ }
+ }
+ }
+ }
+}
diff --git a/compiler/rustc_ast_pretty/src/pprust/tests.rs b/compiler/rustc_ast_pretty/src/pprust/tests.rs
new file mode 100644
index 000000000..6c8d42f33
--- /dev/null
+++ b/compiler/rustc_ast_pretty/src/pprust/tests.rs
@@ -0,0 +1,63 @@
+use super::*;
+
+use rustc_ast as ast;
+use rustc_span::create_default_session_globals_then;
+use rustc_span::symbol::Ident;
+
+fn fun_to_string(
+ decl: &ast::FnDecl,
+ header: ast::FnHeader,
+ name: Ident,
+ generics: &ast::Generics,
+) -> String {
+ to_string(|s| {
+ s.head("");
+ s.print_fn(decl, header, Some(name), generics);
+ s.end(); // Close the head box.
+ s.end(); // Close the outer box.
+ })
+}
+
+fn variant_to_string(var: &ast::Variant) -> String {
+ to_string(|s| s.print_variant(var))
+}
+
+#[test]
+fn test_fun_to_string() {
+ create_default_session_globals_then(|| {
+ let abba_ident = Ident::from_str("abba");
+
+ let decl =
+ ast::FnDecl { inputs: Vec::new(), output: ast::FnRetTy::Default(rustc_span::DUMMY_SP) };
+ let generics = ast::Generics::default();
+ assert_eq!(
+ fun_to_string(&decl, ast::FnHeader::default(), abba_ident, &generics),
+ "fn abba()"
+ );
+ })
+}
+
+#[test]
+fn test_variant_to_string() {
+ create_default_session_globals_then(|| {
+ let ident = Ident::from_str("principal_skinner");
+
+ let var = ast::Variant {
+ ident,
+ vis: ast::Visibility {
+ span: rustc_span::DUMMY_SP,
+ kind: ast::VisibilityKind::Inherited,
+ tokens: None,
+ },
+ attrs: ast::AttrVec::new(),
+ id: ast::DUMMY_NODE_ID,
+ data: ast::VariantData::Unit(ast::DUMMY_NODE_ID),
+ disr_expr: None,
+ span: rustc_span::DUMMY_SP,
+ is_placeholder: false,
+ };
+
+ let varstr = variant_to_string(&var);
+ assert_eq!(varstr, "principal_skinner");
+ })
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-23 03:17:58 +0000