Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

3 files changed, 1370 insertions, 0 deletions

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();
+                }
+            }
+        }
+    }
+}