blob: caf8220bbf43295d608821b1ae564dd41619baba [file] [log] [blame]
use rustc_target::spec::abi::Abi;
use syntax::ast;
use syntax::source_map::{SourceMap, Spanned};
use syntax::parse::ParseSess;
use syntax::print::pp::{self, Breaks};
use syntax::print::pp::Breaks::{Consistent, Inconsistent};
use syntax::print::pprust::{self, Comments, PrintState};
use syntax::symbol::kw;
use syntax::util::parser::{self, AssocOp, Fixity};
use syntax_pos::{self, BytePos, FileName};
use crate::hir;
use crate::hir::{PatKind, GenericBound, TraitBoundModifier, RangeEnd};
use crate::hir::{GenericParam, GenericParamKind, GenericArg};
use crate::hir::ptr::P;
use std::borrow::Cow;
use std::cell::Cell;
use std::vec;
pub enum AnnNode<'a> {
Name(&'a ast::Name),
Block(&'a hir::Block),
Item(&'a hir::Item),
SubItem(hir::HirId),
Expr(&'a hir::Expr),
Pat(&'a hir::Pat),
Arm(&'a hir::Arm),
}
pub enum Nested {
Item(hir::ItemId),
TraitItem(hir::TraitItemId),
ImplItem(hir::ImplItemId),
Body(hir::BodyId),
BodyArgPat(hir::BodyId, usize)
}
pub trait PpAnn {
fn nested(&self, _state: &mut State<'_>, _nested: Nested) {
}
fn pre(&self, _state: &mut State<'_>, _node: AnnNode<'_>) {
}
fn post(&self, _state: &mut State<'_>, _node: AnnNode<'_>) {
}
fn try_fetch_item(&self, _: hir::HirId) -> Option<&hir::Item> {
None
}
}
pub struct NoAnn;
impl PpAnn for NoAnn {}
pub const NO_ANN: &dyn PpAnn = &NoAnn;
impl PpAnn for hir::Crate {
fn try_fetch_item(&self, item: hir::HirId) -> Option<&hir::Item> {
Some(self.item(item))
}
fn nested(&self, state: &mut State<'_>, nested: Nested) {
match nested {
Nested::Item(id) => state.print_item(self.item(id.id)),
Nested::TraitItem(id) => state.print_trait_item(self.trait_item(id)),
Nested::ImplItem(id) => state.print_impl_item(self.impl_item(id)),
Nested::Body(id) => state.print_expr(&self.body(id).value),
Nested::BodyArgPat(id, i) => state.print_pat(&self.body(id).arguments[i].pat)
}
}
}
pub struct State<'a> {
pub s: pp::Printer,
comments: Option<Comments<'a>>,
ann: &'a (dyn PpAnn + 'a),
}
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
}
}
impl<'a> PrintState<'a> for State<'a> {
fn comments(&mut self) -> &mut Option<Comments<'a>> {
&mut self.comments
}
fn print_ident(&mut self, ident: ast::Ident) {
self.s.word(pprust::ast_ident_to_string(ident, ident.is_raw_guess()));
self.ann.post(self, AnnNode::Name(&ident.name))
}
fn print_generic_args(&mut self, args: &ast::GenericArgs, _colons_before_params: bool) {
span_bug!(args.span(), "AST generic args printed by HIR pretty-printer");
}
}
pub const INDENT_UNIT: usize = 4;
/// Requires you to pass an input filename and reader so that
/// it can scan the input text for comments to copy forward.
pub fn print_crate<'a>(cm: &'a SourceMap,
sess: &ParseSess,
krate: &hir::Crate,
filename: FileName,
input: String,
ann: &'a dyn PpAnn) -> String {
let mut s = State::new_from_input(cm, sess, filename, input, ann);
// When printing the AST, we sometimes need to inject `#[no_std]` here.
// Since you can't compile the HIR, it's not necessary.
s.print_mod(&krate.module, &krate.attrs);
s.print_remaining_comments();
s.s.eof()
}
impl<'a> State<'a> {
pub fn new_from_input(cm: &'a SourceMap,
sess: &ParseSess,
filename: FileName,
input: String,
ann: &'a dyn PpAnn)
-> State<'a> {
State {
s: pp::mk_printer(),
comments: Some(Comments::new(cm, sess, filename, input)),
ann,
}
}
}
pub fn to_string<F>(ann: &dyn PpAnn, f: F) -> String
where F: FnOnce(&mut State<'_>)
{
let mut printer = State {
s: pp::mk_printer(),
comments: None,
ann,
};
f(&mut printer);
printer.s.eof()
}
pub fn visibility_qualified<S: Into<Cow<'static, str>>>(vis: &hir::Visibility, w: S) -> String {
to_string(NO_ANN, |s| {
s.print_visibility(vis);
s.s.word(w)
})
}
impl<'a> State<'a> {
pub fn cbox(&mut self, u: usize) {
self.s.cbox(u);
}
pub fn nbsp(&mut self) {
self.s.word(" ")
}
pub fn word_nbsp<S: Into<Cow<'static, str>>>(&mut self, w: S) {
self.s.word(w);
self.nbsp()
}
pub fn head<S: Into<Cow<'static, str>>>(&mut self, w: S) {
let w = w.into();
// outer-box is consistent
self.cbox(INDENT_UNIT);
// head-box is inconsistent
self.ibox(w.len() + 1);
// keyword that starts the head
if !w.is_empty() {
self.word_nbsp(w);
}
}
pub fn bopen(&mut self) {
self.s.word("{");
self.end(); // close the head-box
}
pub fn bclose_maybe_open(&mut self,
span: syntax_pos::Span,
close_box: bool)
{
self.maybe_print_comment(span.hi());
self.break_offset_if_not_bol(1, -(INDENT_UNIT as isize));
self.s.word("}");
if close_box {
self.end(); // close the outer-box
}
}
pub fn bclose(&mut self, span: syntax_pos::Span) {
self.bclose_maybe_open(span, true)
}
pub fn space_if_not_bol(&mut self) {
if !self.s.is_beginning_of_line() {
self.s.space();
}
}
pub fn break_offset_if_not_bol(&mut self, n: usize, off: isize) {
if !self.s.is_beginning_of_line() {
self.s.break_offset(n, off)
} else {
if off != 0 && self.s.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.s.replace_last_token(pp::Printer::hardbreak_tok_offset(off));
}
}
}
// Synthesizes a comment that was not textually present in the original source
// file.
pub fn synth_comment(&mut self, text: String) {
self.s.word("/*");
self.s.space();
self.s.word(text);
self.s.space();
self.s.word("*/")
}
pub 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) -> syntax_pos::Span
{
self.rbox(0, b);
let len = elts.len();
let mut i = 0;
for elt in elts {
self.maybe_print_comment(get_span(elt).hi());
op(self, elt);
i += 1;
if i < len {
self.s.word(",");
self.maybe_print_trailing_comment(get_span(elt), Some(get_span(&elts[i]).hi()));
self.space_if_not_bol();
}
}
self.end();
}
pub fn commasep_exprs(&mut self, b: Breaks, exprs: &[hir::Expr]) {
self.commasep_cmnt(b, exprs, |s, e| s.print_expr(&e), |e| e.span)
}
pub fn print_mod(&mut self, _mod: &hir::Mod, attrs: &[ast::Attribute]) {
self.print_inner_attributes(attrs);
for &item_id in &_mod.item_ids {
self.ann.nested(self, Nested::Item(item_id));
}
}
pub fn print_foreign_mod(&mut self,
nmod: &hir::ForeignMod,
attrs: &[ast::Attribute])
{
self.print_inner_attributes(attrs);
for item in &nmod.items {
self.print_foreign_item(item);
}
}
pub fn print_opt_lifetime(&mut self, lifetime: &hir::Lifetime) {
if !lifetime.is_elided() {
self.print_lifetime(lifetime);
self.nbsp();
}
}
pub fn print_type(&mut self, ty: &hir::Ty) {
self.maybe_print_comment(ty.span.lo());
self.ibox(0);
match ty.node {
hir::TyKind::Slice(ref ty) => {
self.s.word("[");
self.print_type(&ty);
self.s.word("]");
}
hir::TyKind::Ptr(ref mt) => {
self.s.word("*");
match mt.mutbl {
hir::MutMutable => self.word_nbsp("mut"),
hir::MutImmutable => self.word_nbsp("const"),
}
self.print_type(&mt.ty);
}
hir::TyKind::Rptr(ref lifetime, ref mt) => {
self.s.word("&");
self.print_opt_lifetime(lifetime);
self.print_mt(mt);
}
hir::TyKind::Never => {
self.s.word("!");
},
hir::TyKind::Tup(ref elts) => {
self.popen();
self.commasep(Inconsistent, &elts[..], |s, ty| s.print_type(&ty));
if elts.len() == 1 {
self.s.word(",");
}
self.pclose();
}
hir::TyKind::BareFn(ref f) => {
self.print_ty_fn(f.abi, f.unsafety, &f.decl, None, &f.generic_params,
&f.arg_names[..]);
}
hir::TyKind::Def(..) => {},
hir::TyKind::Path(ref qpath) => {
self.print_qpath(qpath, false)
}
hir::TyKind::TraitObject(ref bounds, ref lifetime) => {
let mut first = true;
for bound in bounds {
if first {
first = false;
} else {
self.nbsp();
self.word_space("+");
}
self.print_poly_trait_ref(bound);
}
if !lifetime.is_elided() {
self.nbsp();
self.word_space("+");
self.print_lifetime(lifetime);
}
}
hir::TyKind::Array(ref ty, ref length) => {
self.s.word("[");
self.print_type(&ty);
self.s.word("; ");
self.print_anon_const(length);
self.s.word("]");
}
hir::TyKind::Typeof(ref e) => {
self.s.word("typeof(");
self.print_anon_const(e);
self.s.word(")");
}
hir::TyKind::Infer => {
self.s.word("_");
}
hir::TyKind::Err => {
self.popen();
self.s.word("/*ERROR*/");
self.pclose();
}
hir::TyKind::CVarArgs(_) => {
self.s.word("...");
}
}
self.end()
}
pub fn print_foreign_item(&mut self, item: &hir::ForeignItem) {
self.hardbreak_if_not_bol();
self.maybe_print_comment(item.span.lo());
self.print_outer_attributes(&item.attrs);
match item.node {
hir::ForeignItemKind::Fn(ref decl, ref arg_names, ref generics) => {
self.head("");
self.print_fn(decl,
hir::FnHeader {
unsafety: hir::Unsafety::Normal,
constness: hir::Constness::NotConst,
abi: Abi::Rust,
asyncness: hir::IsAsync::NotAsync,
},
Some(item.ident.name),
generics,
&item.vis,
arg_names,
None);
self.end(); // end head-ibox
self.s.word(";");
self.end() // end the outer fn box
}
hir::ForeignItemKind::Static(ref t, m) => {
self.head(visibility_qualified(&item.vis, "static"));
if m == hir::MutMutable {
self.word_space("mut");
}
self.print_ident(item.ident);
self.word_space(":");
self.print_type(&t);
self.s.word(";");
self.end(); // end the head-ibox
self.end() // end the outer cbox
}
hir::ForeignItemKind::Type => {
self.head(visibility_qualified(&item.vis, "type"));
self.print_ident(item.ident);
self.s.word(";");
self.end(); // end the head-ibox
self.end() // end the outer cbox
}
}
}
fn print_associated_const(&mut self,
ident: ast::Ident,
ty: &hir::Ty,
default: Option<hir::BodyId>,
vis: &hir::Visibility)
{
self.s.word(visibility_qualified(vis, ""));
self.word_space("const");
self.print_ident(ident);
self.word_space(":");
self.print_type(ty);
if let Some(expr) = default {
self.s.space();
self.word_space("=");
self.ann.nested(self, Nested::Body(expr));
}
self.s.word(";")
}
fn print_associated_type(&mut self,
ident: ast::Ident,
bounds: Option<&hir::GenericBounds>,
ty: Option<&hir::Ty>)
{
self.word_space("type");
self.print_ident(ident);
if let Some(bounds) = bounds {
self.print_bounds(":", bounds);
}
if let Some(ty) = ty {
self.s.space();
self.word_space("=");
self.print_type(ty);
}
self.s.word(";")
}
fn print_item_type(
&mut self,
item: &hir::Item,
generics: &hir::Generics,
inner: impl Fn(&mut Self),
) {
self.head(visibility_qualified(&item.vis, "type"));
self.print_ident(item.ident);
self.print_generic_params(&generics.params);
self.end(); // end the inner ibox
self.print_where_clause(&generics.where_clause);
self.s.space();
inner(self);
self.s.word(";");
self.end(); // end the outer ibox
}
/// Pretty-print an item
pub fn print_item(&mut self, item: &hir::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.node {
hir::ItemKind::ExternCrate(orig_name) => {
self.head(visibility_qualified(&item.vis, "extern crate"));
if let Some(orig_name) = orig_name {
self.print_name(orig_name);
self.s.space();
self.s.word("as");
self.s.space();
}
self.print_ident(item.ident);
self.s.word(";");
self.end(); // end inner head-block
self.end(); // end outer head-block
}
hir::ItemKind::Use(ref path, kind) => {
self.head(visibility_qualified(&item.vis, "use"));
self.print_path(path, false);
match kind {
hir::UseKind::Single => {
if path.segments.last().unwrap().ident != item.ident {
self.s.space();
self.word_space("as");
self.print_ident(item.ident);
}
self.s.word(";");
}
hir::UseKind::Glob => self.s.word("::*;"),
hir::UseKind::ListStem => self.s.word("::{};")
}
self.end(); // end inner head-block
self.end(); // end outer head-block
}
hir::ItemKind::Static(ref ty, m, expr) => {
self.head(visibility_qualified(&item.vis, "static"));
if m == hir::MutMutable {
self.word_space("mut");
}
self.print_ident(item.ident);
self.word_space(":");
self.print_type(&ty);
self.s.space();
self.end(); // end the head-ibox
self.word_space("=");
self.ann.nested(self, Nested::Body(expr));
self.s.word(";");
self.end(); // end the outer cbox
}
hir::ItemKind::Const(ref ty, expr) => {
self.head(visibility_qualified(&item.vis, "const"));
self.print_ident(item.ident);
self.word_space(":");
self.print_type(&ty);
self.s.space();
self.end(); // end the head-ibox
self.word_space("=");
self.ann.nested(self, Nested::Body(expr));
self.s.word(";");
self.end(); // end the outer cbox
}
hir::ItemKind::Fn(ref decl, header, ref param_names, body) => {
self.head("");
self.print_fn(decl,
header,
Some(item.ident.name),
param_names,
&item.vis,
&[],
Some(body));
self.s.word(" ");
self.end(); // need to close a box
self.end(); // need to close a box
self.ann.nested(self, Nested::Body(body));
}
hir::ItemKind::Mod(ref _mod) => {
self.head(visibility_qualified(&item.vis, "mod"));
self.print_ident(item.ident);
self.nbsp();
self.bopen();
self.print_mod(_mod, &item.attrs);
self.bclose(item.span);
}
hir::ItemKind::ForeignMod(ref nmod) => {
self.head("extern");
self.word_nbsp(nmod.abi.to_string());
self.bopen();
self.print_foreign_mod(nmod, &item.attrs);
self.bclose(item.span);
}
hir::ItemKind::GlobalAsm(ref ga) => {
self.head(visibility_qualified(&item.vis, "global asm"));
self.s.word(ga.asm.as_str().to_string());
self.end()
}
hir::ItemKind::TyAlias(ref ty, ref generics) => {
self.print_item_type(item, &generics, |state| {
state.word_space("=");
state.print_type(&ty);
});
}
hir::ItemKind::OpaqueTy(ref opaque_ty) => {
self.print_item_type(item, &opaque_ty.generics, |state| {
let mut real_bounds = Vec::with_capacity(opaque_ty.bounds.len());
for b in opaque_ty.bounds.iter() {
if let GenericBound::Trait(ref ptr, hir::TraitBoundModifier::Maybe) = *b {
state.s.space();
state.word_space("for ?");
state.print_trait_ref(&ptr.trait_ref);
} else {
real_bounds.push(b);
}
}
state.print_bounds("= impl", real_bounds);
});
}
hir::ItemKind::Enum(ref enum_definition, ref params) => {
self.print_enum_def(enum_definition, params, item.ident.name, item.span, &item.vis);
}
hir::ItemKind::Struct(ref struct_def, ref generics) => {
self.head(visibility_qualified(&item.vis, "struct"));
self.print_struct(struct_def, generics, item.ident.name, item.span, true);
}
hir::ItemKind::Union(ref struct_def, ref generics) => {
self.head(visibility_qualified(&item.vis, "union"));
self.print_struct(struct_def, generics, item.ident.name, item.span, true);
}
hir::ItemKind::Impl(unsafety,
polarity,
defaultness,
ref generics,
ref opt_trait,
ref ty,
ref impl_items) => {
self.head("");
self.print_visibility(&item.vis);
self.print_defaultness(defaultness);
self.print_unsafety(unsafety);
self.word_nbsp("impl");
if !generics.params.is_empty() {
self.print_generic_params(&generics.params);
self.s.space();
}
if let hir::ImplPolarity::Negative = polarity {
self.s.word("!");
}
if let Some(ref t) = opt_trait {
self.print_trait_ref(t);
self.s.space();
self.word_space("for");
}
self.print_type(&ty);
self.print_where_clause(&generics.where_clause);
self.s.space();
self.bopen();
self.print_inner_attributes(&item.attrs);
for impl_item in impl_items {
self.ann.nested(self, Nested::ImplItem(impl_item.id));
}
self.bclose(item.span);
}
hir::ItemKind::Trait(is_auto, unsafety, ref generics, ref bounds, ref trait_items) => {
self.head("");
self.print_visibility(&item.vis);
self.print_is_auto(is_auto);
self.print_unsafety(unsafety);
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, hir::TraitBoundModifier::Maybe) = *b {
self.s.space();
self.word_space("for ?");
self.print_trait_ref(&ptr.trait_ref);
} else {
real_bounds.push(b);
}
}
self.print_bounds(":", real_bounds);
self.print_where_clause(&generics.where_clause);
self.s.word(" ");
self.bopen();
for trait_item in trait_items {
self.ann.nested(self, Nested::TraitItem(trait_item.id));
}
self.bclose(item.span);
}
hir::ItemKind::TraitAlias(ref generics, ref bounds) => {
self.head("");
self.print_visibility(&item.vis);
self.word_nbsp("trait");
self.print_ident(item.ident);
self.print_generic_params(&generics.params);
let mut real_bounds = Vec::with_capacity(bounds.len());
// FIXME(durka) this seems to be some quite outdated syntax
for b in bounds.iter() {
if let GenericBound::Trait(ref ptr, hir::TraitBoundModifier::Maybe) = *b {
self.s.space();
self.word_space("for ?");
self.print_trait_ref(&ptr.trait_ref);
} else {
real_bounds.push(b);
}
}
self.nbsp();
self.print_bounds("=", real_bounds);
self.print_where_clause(&generics.where_clause);
self.s.word(";");
}
}
self.ann.post(self, AnnNode::Item(item))
}
pub fn print_trait_ref(&mut self, t: &hir::TraitRef) {
self.print_path(&t.path, false)
}
fn print_formal_generic_params(
&mut self,
generic_params: &[hir::GenericParam]
) {
if !generic_params.is_empty() {
self.s.word("for");
self.print_generic_params(generic_params);
self.nbsp();
}
}
fn print_poly_trait_ref(&mut self, t: &hir::PolyTraitRef) {
self.print_formal_generic_params(&t.bound_generic_params);
self.print_trait_ref(&t.trait_ref)
}
pub fn print_enum_def(&mut self,
enum_definition: &hir::EnumDef,
generics: &hir::Generics,
name: ast::Name,
span: syntax_pos::Span,
visibility: &hir::Visibility)
{
self.head(visibility_qualified(visibility, "enum"));
self.print_name(name);
self.print_generic_params(&generics.params);
self.print_where_clause(&generics.where_clause);
self.s.space();
self.print_variants(&enum_definition.variants, span)
}
pub fn print_variants(&mut self,
variants: &[hir::Variant],
span: syntax_pos::Span)
{
self.bopen();
for v in variants {
self.space_if_not_bol();
self.maybe_print_comment(v.span.lo());
self.print_outer_attributes(&v.attrs);
self.ibox(INDENT_UNIT);
self.print_variant(v);
self.s.word(",");
self.end();
self.maybe_print_trailing_comment(v.span, None);
}
self.bclose(span)
}
pub fn print_visibility(&mut self, vis: &hir::Visibility) {
match vis.node {
hir::VisibilityKind::Public => self.word_nbsp("pub"),
hir::VisibilityKind::Crate(ast::CrateSugar::JustCrate) => self.word_nbsp("crate"),
hir::VisibilityKind::Crate(ast::CrateSugar::PubCrate) => self.word_nbsp("pub(crate)"),
hir::VisibilityKind::Restricted { ref path, .. } => {
self.s.word("pub(");
if path.segments.len() == 1 &&
path.segments[0].ident.name == kw::Super {
// Special case: `super` can print like `pub(super)`.
self.s.word("super");
} else {
// Everything else requires `in` at present.
self.word_nbsp("in");
self.print_path(path, false);
}
self.word_nbsp(")");
}
hir::VisibilityKind::Inherited => ()
}
}
pub fn print_defaultness(&mut self, defaultness: hir::Defaultness) {
match defaultness {
hir::Defaultness::Default { .. } => self.word_nbsp("default"),
hir::Defaultness::Final => (),
}
}
pub fn print_struct(&mut self,
struct_def: &hir::VariantData,
generics: &hir::Generics,
name: ast::Name,
span: syntax_pos::Span,
print_finalizer: bool)
{
self.print_name(name);
self.print_generic_params(&generics.params);
match struct_def {
hir::VariantData::Tuple(..) | hir::VariantData::Unit(..) => {
if let hir::VariantData::Tuple(..) = struct_def {
self.popen();
self.commasep(Inconsistent, struct_def.fields(), |s, field| {
s.maybe_print_comment(field.span.lo());
s.print_outer_attributes(&field.attrs);
s.print_visibility(&field.vis);
s.print_type(&field.ty)
});
self.pclose();
}
self.print_where_clause(&generics.where_clause);
if print_finalizer {
self.s.word(";");
}
self.end();
self.end() // close the outer-box
}
hir::VariantData::Struct(..) => {
self.print_where_clause(&generics.where_clause);
self.nbsp();
self.bopen();
self.hardbreak_if_not_bol();
for field in struct_def.fields() {
self.hardbreak_if_not_bol();
self.maybe_print_comment(field.span.lo());
self.print_outer_attributes(&field.attrs);
self.print_visibility(&field.vis);
self.print_ident(field.ident);
self.word_nbsp(":");
self.print_type(&field.ty);
self.s.word(",");
}
self.bclose(span)
}
}
}
pub fn print_variant(&mut self, v: &hir::Variant) {
self.head("");
let generics = hir::Generics::empty();
self.print_struct(&v.data, &generics, v.ident.name, v.span, false);
if let Some(ref d) = v.disr_expr {
self.s.space();
self.word_space("=");
self.print_anon_const(d);
}
}
pub fn print_method_sig(&mut self,
ident: ast::Ident,
m: &hir::MethodSig,
generics: &hir::Generics,
vis: &hir::Visibility,
arg_names: &[ast::Ident],
body_id: Option<hir::BodyId>)
{
self.print_fn(&m.decl,
m.header,
Some(ident.name),
generics,
vis,
arg_names,
body_id)
}
pub fn print_trait_item(&mut self, ti: &hir::TraitItem) {
self.ann.pre(self, AnnNode::SubItem(ti.hir_id));
self.hardbreak_if_not_bol();
self.maybe_print_comment(ti.span.lo());
self.print_outer_attributes(&ti.attrs);
match ti.node {
hir::TraitItemKind::Const(ref ty, default) => {
let vis = Spanned { span: syntax_pos::DUMMY_SP,
node: hir::VisibilityKind::Inherited };
self.print_associated_const(ti.ident, &ty, default, &vis);
}
hir::TraitItemKind::Method(ref sig, hir::TraitMethod::Required(ref arg_names)) => {
let vis = Spanned { span: syntax_pos::DUMMY_SP,
node: hir::VisibilityKind::Inherited };
self.print_method_sig(ti.ident, sig, &ti.generics, &vis, arg_names, None);
self.s.word(";");
}
hir::TraitItemKind::Method(ref sig, hir::TraitMethod::Provided(body)) => {
let vis = Spanned { span: syntax_pos::DUMMY_SP,
node: hir::VisibilityKind::Inherited };
self.head("");
self.print_method_sig(ti.ident, sig, &ti.generics, &vis, &[], Some(body));
self.nbsp();
self.end(); // need to close a box
self.end(); // need to close a box
self.ann.nested(self, Nested::Body(body));
}
hir::TraitItemKind::Type(ref bounds, ref default) => {
self.print_associated_type(ti.ident,
Some(bounds),
default.as_ref().map(|ty| &**ty));
}
}
self.ann.post(self, AnnNode::SubItem(ti.hir_id))
}
pub fn print_impl_item(&mut self, ii: &hir::ImplItem) {
self.ann.pre(self, AnnNode::SubItem(ii.hir_id));
self.hardbreak_if_not_bol();
self.maybe_print_comment(ii.span.lo());
self.print_outer_attributes(&ii.attrs);
self.print_defaultness(ii.defaultness);
match ii.node {
hir::ImplItemKind::Const(ref ty, expr) => {
self.print_associated_const(ii.ident, &ty, Some(expr), &ii.vis);
}
hir::ImplItemKind::Method(ref sig, body) => {
self.head("");
self.print_method_sig(ii.ident, sig, &ii.generics, &ii.vis, &[], Some(body));
self.nbsp();
self.end(); // need to close a box
self.end(); // need to close a box
self.ann.nested(self, Nested::Body(body));
}
hir::ImplItemKind::TyAlias(ref ty) => {
self.print_associated_type(ii.ident, None, Some(ty));
}
hir::ImplItemKind::OpaqueTy(ref bounds) => {
self.word_space("type");
self.print_ident(ii.ident);
self.print_bounds("= impl", bounds);
self.s.word(";");
}
}
self.ann.post(self, AnnNode::SubItem(ii.hir_id))
}
pub fn print_local(
&mut self,
init: Option<&hir::Expr>,
decl: impl Fn(&mut Self)
) {
self.space_if_not_bol();
self.ibox(INDENT_UNIT);
self.word_nbsp("let");
self.ibox(INDENT_UNIT);
decl(self);
self.end();
if let Some(ref init) = init {
self.nbsp();
self.word_space("=");
self.print_expr(&init);
}
self.end()
}
pub fn print_stmt(&mut self, st: &hir::Stmt) {
self.maybe_print_comment(st.span.lo());
match st.node {
hir::StmtKind::Local(ref loc) => {
self.print_local(loc.init.as_deref(), |this| this.print_local_decl(&loc));
}
hir::StmtKind::Item(item) => {
self.ann.nested(self, Nested::Item(item))
}
hir::StmtKind::Expr(ref expr) => {
self.space_if_not_bol();
self.print_expr(&expr);
}
hir::StmtKind::Semi(ref expr) => {
self.space_if_not_bol();
self.print_expr(&expr);
self.s.word(";");
}
}
if stmt_ends_with_semi(&st.node) {
self.s.word(";");
}
self.maybe_print_trailing_comment(st.span, None)
}
pub fn print_block(&mut self, blk: &hir::Block) {
self.print_block_with_attrs(blk, &[])
}
pub fn print_block_unclosed(&mut self, blk: &hir::Block) {
self.print_block_maybe_unclosed(blk, &[], false)
}
pub fn print_block_with_attrs(&mut self,
blk: &hir::Block,
attrs: &[ast::Attribute])
{
self.print_block_maybe_unclosed(blk, attrs, true)
}
pub fn print_block_maybe_unclosed(&mut self,
blk: &hir::Block,
attrs: &[ast::Attribute],
close_box: bool)
{
match blk.rules {
hir::UnsafeBlock(..) => self.word_space("unsafe"),
hir::PushUnsafeBlock(..) => self.word_space("push_unsafe"),
hir::PopUnsafeBlock(..) => self.word_space("pop_unsafe"),
hir::DefaultBlock => (),
}
self.maybe_print_comment(blk.span.lo());
self.ann.pre(self, AnnNode::Block(blk));
self.bopen();
self.print_inner_attributes(attrs);
for st in &blk.stmts {
self.print_stmt(st);
}
if let Some(ref expr) = blk.expr {
self.space_if_not_bol();
self.print_expr(&expr);
self.maybe_print_trailing_comment(expr.span, Some(blk.span.hi()));
}
self.bclose_maybe_open(blk.span, close_box);
self.ann.post(self, AnnNode::Block(blk))
}
pub fn print_anon_const(&mut self, constant: &hir::AnonConst) {
self.ann.nested(self, Nested::Body(constant.body))
}
fn print_call_post(&mut self, args: &[hir::Expr]) {
self.popen();
self.commasep_exprs(Inconsistent, args);
self.pclose()
}
pub fn print_expr_maybe_paren(&mut self, expr: &hir::Expr, prec: i8) {
let needs_par = expr.precedence().order() < prec;
if needs_par {
self.popen();
}
self.print_expr(expr);
if needs_par {
self.pclose();
}
}
/// Print an expr using syntax that's acceptable in a condition position, such as the `cond` in
/// `if cond { ... }`.
pub fn print_expr_as_cond(&mut self, expr: &hir::Expr) {
let needs_par = match expr.node {
// These cases need parens due to the parse error observed in #26461: `if return {}`
// parses as the erroneous construct `if (return {})`, not `if (return) {}`.
hir::ExprKind::Closure(..) |
hir::ExprKind::Ret(..) |
hir::ExprKind::Break(..) => true,
_ => contains_exterior_struct_lit(expr),
};
if needs_par {
self.popen();
}
self.print_expr(expr);
if needs_par {
self.pclose();
}
}
fn print_expr_vec(&mut self, exprs: &[hir::Expr]) {
self.ibox(INDENT_UNIT);
self.s.word("[");
self.commasep_exprs(Inconsistent, exprs);
self.s.word("]");
self.end()
}
fn print_expr_repeat(&mut self, element: &hir::Expr, count: &hir::AnonConst) {
self.ibox(INDENT_UNIT);
self.s.word("[");
self.print_expr(element);
self.word_space(";");
self.print_anon_const(count);
self.s.word("]");
self.end()
}
fn print_expr_struct(&mut self,
qpath: &hir::QPath,
fields: &[hir::Field],
wth: &Option<P<hir::Expr>>)
{
self.print_qpath(qpath, true);
self.s.word("{");
self.commasep_cmnt(Consistent,
&fields[..],
|s, field| {
s.ibox(INDENT_UNIT);
if !field.is_shorthand {
s.print_ident(field.ident);
s.word_space(":");
}
s.print_expr(&field.expr);
s.end()
},
|f| f.span);
match *wth {
Some(ref expr) => {
self.ibox(INDENT_UNIT);
if !fields.is_empty() {
self.s.word(",");
self.s.space();
}
self.s.word("..");
self.print_expr(&expr);
self.end();
}
_ => if !fields.is_empty() {
self.s.word(",")
},
}
self.s.word("}");
}
fn print_expr_tup(&mut self, exprs: &[hir::Expr]) {
self.popen();
self.commasep_exprs(Inconsistent, exprs);
if exprs.len() == 1 {
self.s.word(",");
}
self.pclose()
}
fn print_expr_call(&mut self, func: &hir::Expr, args: &[hir::Expr]) {
let prec =
match func.node {
hir::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: &hir::PathSegment,
args: &[hir::Expr])
{
let base_args = &args[1..];
self.print_expr_maybe_paren(&args[0], parser::PREC_POSTFIX);
self.s.word(".");
self.print_ident(segment.ident);
let generic_args = segment.generic_args();
if !generic_args.args.is_empty() || !generic_args.bindings.is_empty() {
self.print_generic_args(generic_args, segment.infer_args, true);
}
self.print_call_post(base_args)
}
fn print_expr_binary(&mut self,
op: hir::BinOp,
lhs: &hir::Expr,
rhs: &hir::Expr)
{
let assoc_op = bin_op_to_assoc_op(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.node, 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.
(&hir::ExprKind::Cast { .. }, hir::BinOpKind::Lt) |
(&hir::ExprKind::Cast { .. }, hir::BinOpKind::Shl) => parser::PREC_FORCE_PAREN,
_ => left_prec,
};
self.print_expr_maybe_paren(lhs, left_prec);
self.s.space();
self.word_space(op.node.as_str());
self.print_expr_maybe_paren(rhs, right_prec)
}
fn print_expr_unary(&mut self, op: hir::UnOp, expr: &hir::Expr) {
self.s.word(op.as_str());
self.print_expr_maybe_paren(expr, parser::PREC_PREFIX)
}
fn print_expr_addr_of(&mut self,
mutability: hir::Mutability,
expr: &hir::Expr)
{
self.s.word("&");
self.print_mutability(mutability);
self.print_expr_maybe_paren(expr, parser::PREC_PREFIX)
}
fn print_literal(&mut self, lit: &hir::Lit) {
self.maybe_print_comment(lit.span.lo());
self.word(lit.node.to_lit_token().to_string())
}
pub fn print_expr(&mut self, expr: &hir::Expr) {
self.maybe_print_comment(expr.span.lo());
self.print_outer_attributes(&expr.attrs);
self.ibox(INDENT_UNIT);
self.ann.pre(self, AnnNode::Expr(expr));
match expr.node {
hir::ExprKind::Box(ref expr) => {
self.word_space("box");
self.print_expr_maybe_paren(expr, parser::PREC_PREFIX);
}
hir::ExprKind::Array(ref exprs) => {
self.print_expr_vec(exprs);
}
hir::ExprKind::Repeat(ref element, ref count) => {
self.print_expr_repeat(&element, count);
}
hir::ExprKind::Struct(ref qpath, ref fields, ref wth) => {
self.print_expr_struct(qpath, &fields[..], wth);
}
hir::ExprKind::Tup(ref exprs) => {
self.print_expr_tup(exprs);
}
hir::ExprKind::Call(ref func, ref args) => {
self.print_expr_call(&func, args);
}
hir::ExprKind::MethodCall(ref segment, _, ref args) => {
self.print_expr_method_call(segment, args);
}
hir::ExprKind::Binary(op, ref lhs, ref rhs) => {
self.print_expr_binary(op, &lhs, &rhs);
}
hir::ExprKind::Unary(op, ref expr) => {
self.print_expr_unary(op, &expr);
}
hir::ExprKind::AddrOf(m, ref expr) => {
self.print_expr_addr_of(m, &expr);
}
hir::ExprKind::Lit(ref lit) => {
self.print_literal(&lit);
}
hir::ExprKind::Cast(ref expr, ref ty) => {
let prec = AssocOp::As.precedence() as i8;
self.print_expr_maybe_paren(&expr, prec);
self.s.space();
self.word_space("as");
self.print_type(&ty);
}
hir::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);
}
hir::ExprKind::DropTemps(ref init) => {
// Print `{`:
self.cbox(INDENT_UNIT);
self.ibox(0);
self.bopen();
// Print `let _t = $init;`:
let temp = ast::Ident::from_str("_t");
self.print_local(Some(init), |this| this.print_ident(temp));
self.s.word(";");
// Print `_t`:
self.space_if_not_bol();
self.print_ident(temp);
// Print `}`:
self.bclose_maybe_open(expr.span, true);
}
hir::ExprKind::Loop(ref blk, opt_label, _) => {
if let Some(label) = opt_label {
self.print_ident(label.ident);
self.word_space(":");
}
self.head("loop");
self.s.space();
self.print_block(&blk);
}
hir::ExprKind::Match(ref expr, ref arms, _) => {
self.cbox(INDENT_UNIT);
self.ibox(INDENT_UNIT);
self.word_nbsp("match");
self.print_expr_as_cond(&expr);
self.s.space();
self.bopen();
for arm in arms {
self.print_arm(arm);
}
self.bclose(expr.span);
}
hir::ExprKind::Closure(capture_clause, ref decl, body, _fn_decl_span, _gen) => {
self.print_capture_clause(capture_clause);
self.print_closure_args(&decl, body);
self.s.space();
// this is a bare expression
self.ann.nested(self, Nested::Body(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);
}
hir::ExprKind::Block(ref blk, opt_label) => {
if let Some(label) = opt_label {
self.print_ident(label.ident);
self.word_space(":");
}
// containing cbox, will be closed by print-block at }
self.cbox(INDENT_UNIT);
// head-box, will be closed by print-block after {
self.ibox(0);
self.print_block(&blk);
}
hir::ExprKind::Assign(ref lhs, ref rhs) => {
let prec = AssocOp::Assign.precedence() as i8;
self.print_expr_maybe_paren(&lhs, prec + 1);
self.s.space();
self.word_space("=");
self.print_expr_maybe_paren(&rhs, prec);
}
hir::ExprKind::AssignOp(op, ref lhs, ref rhs) => {
let prec = AssocOp::Assign.precedence() as i8;
self.print_expr_maybe_paren(&lhs, prec + 1);
self.s.space();
self.s.word(op.node.as_str());
self.word_space("=");
self.print_expr_maybe_paren(&rhs, prec);
}
hir::ExprKind::Field(ref expr, ident) => {
self.print_expr_maybe_paren(expr, parser::PREC_POSTFIX);
self.s.word(".");
self.print_ident(ident);
}
hir::ExprKind::Index(ref expr, ref index) => {
self.print_expr_maybe_paren(&expr, parser::PREC_POSTFIX);
self.s.word("[");
self.print_expr(&index);
self.s.word("]");
}
hir::ExprKind::Path(ref qpath) => {
self.print_qpath(qpath, true)
}
hir::ExprKind::Break(destination, ref opt_expr) => {
self.s.word("break");
self.s.space();
if let Some(label) = destination.label {
self.print_ident(label.ident);
self.s.space();
}
if let Some(ref expr) = *opt_expr {
self.print_expr_maybe_paren(expr, parser::PREC_JUMP);
self.s.space();
}
}
hir::ExprKind::Continue(destination) => {
self.s.word("continue");
self.s.space();
if let Some(label) = destination.label {
self.print_ident(label.ident);
self.s.space()
}
}
hir::ExprKind::Ret(ref result) => {
self.s.word("return");
if let Some(ref expr) = *result {
self.s.word(" ");
self.print_expr_maybe_paren(&expr, parser::PREC_JUMP);
}
}
hir::ExprKind::InlineAsm(ref a, ref outputs, ref inputs) => {
self.s.word("asm!");
self.popen();
self.print_string(&a.asm.as_str(), a.asm_str_style);
self.word_space(":");
let mut out_idx = 0;
self.commasep(Inconsistent, &a.outputs, |s, out| {
let constraint = out.constraint.as_str();
let mut ch = constraint.chars();
match ch.next() {
Some('=') if out.is_rw => {
s.print_string(&format!("+{}", ch.as_str()),
ast::StrStyle::Cooked)
}
_ => s.print_string(&constraint, ast::StrStyle::Cooked),
}
s.popen();
s.print_expr(&outputs[out_idx]);
s.pclose();
out_idx += 1;
});
self.s.space();
self.word_space(":");
let mut in_idx = 0;
self.commasep(Inconsistent, &a.inputs, |s, co| {
s.print_string(&co.as_str(), ast::StrStyle::Cooked);
s.popen();
s.print_expr(&inputs[in_idx]);
s.pclose();
in_idx += 1;
});
self.s.space();
self.word_space(":");
self.commasep(Inconsistent, &a.clobbers, |s, co| {
s.print_string(&co.as_str(), ast::StrStyle::Cooked);
});
let mut options = vec![];
if a.volatile {
options.push("volatile");
}
if a.alignstack {
options.push("alignstack");
}
if a.dialect == ast::AsmDialect::Intel {
options.push("intel");
}
if !options.is_empty() {
self.s.space();
self.word_space(":");
self.commasep(Inconsistent, &options, |s, &co| {
s.print_string(co, ast::StrStyle::Cooked);
});
}
self.pclose();
}
hir::ExprKind::Yield(ref expr, _) => {
self.word_space("yield");
self.print_expr_maybe_paren(&expr, parser::PREC_JUMP);
}
hir::ExprKind::Err => {
self.popen();
self.s.word("/*ERROR*/");
self.pclose();
}
}
self.ann.post(self, AnnNode::Expr(expr));
self.end()
}
pub fn print_local_decl(&mut self, loc: &hir::Local) {
self.print_pat(&loc.pat);
if let Some(ref ty) = loc.ty {
self.word_space(":");
self.print_type(&ty);
}
}
pub fn print_usize(&mut self, i: usize) {
self.s.word(i.to_string())
}
pub fn print_name(&mut self, name: ast::Name) {
self.print_ident(ast::Ident::with_empty_ctxt(name))
}
pub fn print_for_decl(&mut self, loc: &hir::Local, coll: &hir::Expr) {
self.print_local_decl(loc);
self.s.space();
self.word_space("in");
self.print_expr(coll)
}
pub fn print_path(&mut self,
path: &hir::Path,
colons_before_params: bool)
{
self.maybe_print_comment(path.span.lo());
for (i, segment) in path.segments.iter().enumerate() {
if i > 0 {
self.s.word("::")
}
if segment.ident.name != kw::PathRoot {
self.print_ident(segment.ident);
self.print_generic_args(segment.generic_args(), segment.infer_args,
colons_before_params);
}
}
}
pub fn print_path_segment(&mut self, segment: &hir::PathSegment) {
if segment.ident.name != kw::PathRoot {
self.print_ident(segment.ident);
self.print_generic_args(segment.generic_args(), segment.infer_args, false);
}
}
pub fn print_qpath(&mut self,
qpath: &hir::QPath,
colons_before_params: bool)
{
match *qpath {
hir::QPath::Resolved(None, ref path) => {
self.print_path(path, colons_before_params)
}
hir::QPath::Resolved(Some(ref qself), ref path) => {
self.s.word("<");
self.print_type(qself);
self.s.space();
self.word_space("as");
for (i, segment) in path.segments[..path.segments.len() - 1].iter().enumerate() {
if i > 0 {
self.s.word("::")
}
if segment.ident.name != kw::PathRoot {
self.print_ident(segment.ident);
self.print_generic_args(segment.generic_args(),
segment.infer_args,
colons_before_params);
}
}
self.s.word(">");
self.s.word("::");
let item_segment = path.segments.last().unwrap();
self.print_ident(item_segment.ident);
self.print_generic_args(item_segment.generic_args(),
item_segment.infer_args,
colons_before_params)
}
hir::QPath::TypeRelative(ref qself, ref item_segment) => {
self.s.word("<");
self.print_type(qself);
self.s.word(">");
self.s.word("::");
self.print_ident(item_segment.ident);
self.print_generic_args(item_segment.generic_args(),
item_segment.infer_args,
colons_before_params)
}
}
}
fn print_generic_args(&mut self,
generic_args: &hir::GenericArgs,
infer_args: bool,
colons_before_params: bool)
{
if generic_args.parenthesized {
self.s.word("(");
self.commasep(Inconsistent, generic_args.inputs(), |s, ty| s.print_type(&ty));
self.s.word(")");
self.space_if_not_bol();
self.word_space("->");
self.print_type(generic_args.bindings[0].ty());
} else {
let start = if colons_before_params { "::<" } else { "<" };
let empty = Cell::new(true);
let start_or_comma = |this: &mut Self| {
if empty.get() {
empty.set(false);
this.s.word(start)
} else {
this.word_space(",")
}
};
let mut nonelided_generic_args: bool = false;
let elide_lifetimes = generic_args.args.iter().all(|arg| match arg {
GenericArg::Lifetime(lt) => lt.is_elided(),
_ => {
nonelided_generic_args = true;
true
}
});
if nonelided_generic_args {
start_or_comma(self);
self.commasep(Inconsistent, &generic_args.args, |s, generic_arg| {
match generic_arg {
GenericArg::Lifetime(lt) if !elide_lifetimes => s.print_lifetime(lt),
GenericArg::Lifetime(_) => {},
GenericArg::Type(ty) => s.print_type(ty),
GenericArg::Const(ct) => s.print_anon_const(&ct.value),
}
});
}
// FIXME(eddyb): this would leak into error messages (e.g.,
// "non-exhaustive patterns: `Some::<..>(_)` not covered").
if infer_args && false {
start_or_comma(self);
self.s.word("..");
}
for binding in generic_args.bindings.iter() {
start_or_comma(self);
self.print_ident(binding.ident);
self.s.space();
match generic_args.bindings[0].kind {
hir::TypeBindingKind::Equality { ref ty } => {
self.word_space("=");
self.print_type(ty);
}
hir::TypeBindingKind::Constraint { ref bounds } => {
self.print_bounds(":", bounds);
}
}
}
if !empty.get() {
self.s.word(">")
}
}
}
pub fn print_pat(&mut self, pat: &hir::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.node {
PatKind::Wild => self.s.word("_"),
PatKind::Binding(binding_mode, _, ident, ref sub) => {
match binding_mode {
hir::BindingAnnotation::Ref => {
self.word_nbsp("ref");
self.print_mutability(hir::MutImmutable);
}
hir::BindingAnnotation::RefMut => {
self.word_nbsp("ref");
self.print_mutability(hir::MutMutable);
}
hir::BindingAnnotation::Unannotated => {}
hir::BindingAnnotation::Mutable => {
self.word_nbsp("mut");
}
}
self.print_ident(ident);
if let Some(ref p) = *sub {
self.s.word("@");
self.print_pat(&p);
}
}
PatKind::TupleStruct(ref qpath, ref elts, ddpos) => {
self.print_qpath(qpath, true);
self.popen();
if let Some(ddpos) = ddpos {
self.commasep(Inconsistent, &elts[..ddpos], |s, p| s.print_pat(&p));
if ddpos != 0 {
self.word_space(",");
}
self.s.word("..");
if ddpos != elts.len() {
self.s.word(",");
self.commasep(Inconsistent, &elts[ddpos..], |s, p| s.print_pat(&p));
}
} else {
self.commasep(Inconsistent, &elts[..], |s, p| s.print_pat(&p));
}
self.pclose();
}
PatKind::Path(ref qpath) => {
self.print_qpath(qpath, true);
}
PatKind::Struct(ref qpath, ref fields, etc) => {
self.print_qpath(qpath, true);
self.nbsp();
self.word_space("{");
self.commasep_cmnt(Consistent,
&fields[..],
|s, f| {
s.cbox(INDENT_UNIT);
if !f.is_shorthand {
s.print_ident(f.ident);
s.word_nbsp(":");
}
s.print_pat(&f.pat);
s.end()
},
|f| f.pat.span);
if etc {
if !fields.is_empty() {
self.word_space(",");
}
self.s.word("..");
}
self.s.space();
self.s.word("}");
}
PatKind::Tuple(ref elts, ddpos) => {
self.popen();
if let Some(ddpos) = ddpos {
self.commasep(Inconsistent, &elts[..ddpos], |s, p| s.print_pat(&p));
if ddpos != 0 {
self.word_space(",");
}
self.s.word("..");
if ddpos != elts.len() {
self.s.word(",");
self.commasep(Inconsistent, &elts[ddpos..], |s, p| s.print_pat(&p));
}
} else {
self.commasep(Inconsistent, &elts[..], |s, p| s.print_pat(&p));
if elts.len() == 1 {
self.s.word(",");
}
}
self.pclose();
}
PatKind::Box(ref inner) => {
let is_range_inner = match inner.node {
PatKind::Range(..) => true,
_ => false,
};
self.s.word("box ");
if is_range_inner {
self.popen();
}
self.print_pat(&inner);
if is_range_inner {
self.pclose();
}
}
PatKind::Ref(ref inner, mutbl) => {
let is_range_inner = match inner.node {
PatKind::Range(..) => true,
_ => false,
};
self.s.word("&");
if mutbl == hir::MutMutable {
self.s.word("mut ");
}
if is_range_inner {
self.popen();
}
self.print_pat(&inner);
if is_range_inner {
self.pclose();
}
}
PatKind::Lit(ref e) => self.print_expr(&e),
PatKind::Range(ref begin, ref end, ref end_kind) => {
self.print_expr(&begin);
self.s.space();
match *end_kind {
RangeEnd::Included => self.s.word("..."),
RangeEnd::Excluded => self.s.word(".."),
}
self.print_expr(&end);
}
PatKind::Slice(ref before, ref slice, ref after) => {
self.s.word("[");
self.commasep(Inconsistent, &before[..], |s, p| s.print_pat(&p));
if let Some(ref p) = *slice {
if !before.is_empty() {
self.word_space(",");
}
if let PatKind::Wild = p.node {
// Print nothing
} else {
self.print_pat(&p);
}
self.s.word("..");
if !after.is_empty() {
self.word_space(",");
}
}
self.commasep(Inconsistent, &after[..], |s, p| s.print_pat(&p));
self.s.word("]");
}
}
self.ann.post(self, AnnNode::Pat(pat))
}
pub fn print_arg(&mut self, arg: &hir::Arg) {
self.print_outer_attributes(&arg.attrs);
self.print_pat(&arg.pat);
}
pub fn print_arm(&mut self, arm: &hir::Arm) {
// I have no idea why this check is necessary, but here it
// is :(
if arm.attrs.is_empty() {
self.s.space();
}
self.cbox(INDENT_UNIT);
self.ann.pre(self, AnnNode::Arm(arm));
self.ibox(0);
self.print_outer_attributes(&arm.attrs);
let mut first = true;
for p in &arm.pats {
if first {
first = false;
} else {
self.s.space();
self.word_space("|");
}
self.print_pat(&p);
}
self.s.space();
if let Some(ref g) = arm.guard {
match g {
hir::Guard::If(e) => {
self.word_space("if");
self.print_expr(&e);
self.s.space();
}
}
}
self.word_space("=>");
match arm.body.node {
hir::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(&blk);
// If it is a user-provided unsafe block, print a comma after it
if let hir::UnsafeBlock(hir::UserProvided) = blk.rules {
self.s.word(",");
}
}
_ => {
self.end(); // close the ibox for the pattern
self.print_expr(&arm.body);
self.s.word(",");
}
}
self.ann.post(self, AnnNode::Arm(arm));
self.end() // close enclosing cbox
}
pub fn print_fn(&mut self,
decl: &hir::FnDecl,
header: hir::FnHeader,
name: Option<ast::Name>,
generics: &hir::Generics,
vis: &hir::Visibility,
arg_names: &[ast::Ident],
body_id: Option<hir::BodyId>)
{
self.print_fn_header_info(header, vis);
if let Some(name) = name {
self.nbsp();
self.print_name(name);
}
self.print_generic_params(&generics.params);
self.popen();
let mut i = 0;
// Make sure we aren't supplied *both* `arg_names` and `body_id`.
assert!(arg_names.is_empty() || body_id.is_none());
self.commasep(Inconsistent, &decl.inputs, |s, ty| {
s.ibox(INDENT_UNIT);
if let Some(arg_name) = arg_names.get(i) {
s.s.word(arg_name.as_str().to_string());
s.s.word(":");
s.s.space();
} else if let Some(body_id) = body_id {
s.ann.nested(s, Nested::BodyArgPat(body_id, i));
s.s.word(":");
s.s.space();
}
i += 1;
s.print_type(ty);
s.end()
});
if decl.c_variadic {
self.s.word(", ...");
}
self.pclose();
self.print_fn_output(decl);
self.print_where_clause(&generics.where_clause)
}
fn print_closure_args(&mut self, decl: &hir::FnDecl, body_id: hir::BodyId) {
self.s.word("|");
let mut i = 0;
self.commasep(Inconsistent, &decl.inputs, |s, ty| {
s.ibox(INDENT_UNIT);
s.ann.nested(s, Nested::BodyArgPat(body_id, i));
i += 1;
if let hir::TyKind::Infer = ty.node {
// Print nothing
} else {
s.s.word(":");
s.s.space();
s.print_type(ty);
}
s.end();
});
self.s.word("|");
if let hir::DefaultReturn(..) = decl.output {
return;
}
self.space_if_not_bol();
self.word_space("->");
match decl.output {
hir::Return(ref ty) => {
self.print_type(&ty);
self.maybe_print_comment(ty.span.lo())
}
hir::DefaultReturn(..) => unreachable!(),
}
}
pub fn print_capture_clause(&mut self, capture_clause: hir::CaptureClause) {
match capture_clause {
hir::CaptureByValue => self.word_space("move"),
hir::CaptureByRef => {},
}
}
pub fn print_bounds<'b>(
&mut self,
prefix: &'static str,
bounds: impl IntoIterator<Item = &'b hir::GenericBound>,
) {
let mut first = true;
for bound in bounds {
if first {
self.s.word(prefix);
}
if !(first && prefix.is_empty()) {
self.nbsp();
}
if first {
first = false;
} else {
self.word_space("+");
}
match bound {
GenericBound::Trait(tref, modifier) => {
if modifier == &TraitBoundModifier::Maybe {
self.s.word("?");
}
self.print_poly_trait_ref(tref);
}
GenericBound::Outlives(lt) => {
self.print_lifetime(lt);
}
}
}
}
pub fn print_generic_params(&mut self, generic_params: &[GenericParam]) {
if !generic_params.is_empty() {
self.s.word("<");
self.commasep(Inconsistent, generic_params, |s, param| {
s.print_generic_param(param)
});
self.s.word(">");
}
}
pub fn print_generic_param(&mut self, param: &GenericParam) {
if let GenericParamKind::Const { .. } = param.kind {
self.word_space("const");
}
self.print_ident(param.name.ident());
match param.kind {
GenericParamKind::Lifetime { .. } => {
let mut sep = ":";
for bound in &param.bounds {
match bound {
GenericBound::Outlives(lt) => {
self.s.word(sep);
self.print_lifetime(lt);
sep = "+";
}
_ => bug!(),
}
}
}
GenericParamKind::Type { ref default, .. } => {
self.print_bounds(":", &param.bounds);
match default {
Some(default) => {
self.s.space();
self.word_space("=");
self.print_type(&default)
}
_ => {}
}
}
GenericParamKind::Const { ref ty } => {
self.word_space(":");
self.print_type(ty)
}
}
}
pub fn print_lifetime(&mut self, lifetime: &hir::Lifetime) {
self.print_ident(lifetime.name.ident())
}
pub fn print_where_clause(&mut self, where_clause: &hir::WhereClause) {
if where_clause.predicates.is_empty() {
return;
}
self.s.space();
self.word_space("where");
for (i, predicate) in where_clause.predicates.iter().enumerate() {
if i != 0 {
self.word_space(",");
}
match predicate {
&hir::WherePredicate::BoundPredicate(hir::WhereBoundPredicate {
ref bound_generic_params,
ref bounded_ty,
ref bounds,
..
}) => {
self.print_formal_generic_params(bound_generic_params);
self.print_type(&bounded_ty);
self.print_bounds(":", bounds);
}
&hir::WherePredicate::RegionPredicate(hir::WhereRegionPredicate{ref lifetime,
ref bounds,
..}) => {
self.print_lifetime(lifetime);
self.s.word(":");
for (i, bound) in bounds.iter().enumerate() {
match bound {
GenericBound::Outlives(lt) => {
self.print_lifetime(lt);
}
_ => bug!(),
}
if i != 0 {
self.s.word(":");
}
}
}
&hir::WherePredicate::EqPredicate(hir::WhereEqPredicate{ref lhs_ty,
ref rhs_ty,
..}) => {
self.print_type(lhs_ty);
self.s.space();
self.word_space("=");
self.print_type(rhs_ty);
}
}
}
}
pub fn print_mutability(&mut self, mutbl: hir::Mutability) {
match mutbl {
hir::MutMutable => self.word_nbsp("mut"),
hir::MutImmutable => {},
}
}
pub fn print_mt(&mut self, mt: &hir::MutTy) {
self.print_mutability(mt.mutbl);
self.print_type(&mt.ty)
}
pub fn print_fn_output(&mut self, decl: &hir::FnDecl) {
if let hir::DefaultReturn(..) = decl.output {
return;
}
self.space_if_not_bol();
self.ibox(INDENT_UNIT);
self.word_space("->");
match decl.output {
hir::DefaultReturn(..) => unreachable!(),
hir::Return(ref ty) => self.print_type(&ty),
}
self.end();
match decl.output {
hir::Return(ref output) => self.maybe_print_comment(output.span.lo()),
_ => {},
}
}
pub fn print_ty_fn(&mut self,
abi: Abi,
unsafety: hir::Unsafety,
decl: &hir::FnDecl,
name: Option<ast::Name>,
generic_params: &[hir::GenericParam],
arg_names: &[ast::Ident])
{
self.ibox(INDENT_UNIT);
if !generic_params.is_empty() {
self.s.word("for");
self.print_generic_params(generic_params);
}
let generics = hir::Generics {
params: hir::HirVec::new(),
where_clause: hir::WhereClause {
predicates: hir::HirVec::new(),
span: syntax_pos::DUMMY_SP,
},
span: syntax_pos::DUMMY_SP,
};
self.print_fn(decl,
hir::FnHeader {
unsafety,
abi,
constness: hir::Constness::NotConst,
asyncness: hir::IsAsync::NotAsync,
},
name,
&generics,
&Spanned { span: syntax_pos::DUMMY_SP,
node: hir::VisibilityKind::Inherited },
arg_names,
None);
self.end();
}
pub fn maybe_print_trailing_comment(&mut self,
span: syntax_pos::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);
}
}
}
pub fn print_remaining_comments(&mut self) {
// If there aren't any remaining comments, then we need to manually
// make sure there is a line break at the end.
if self.next_comment().is_none() {
self.s.hardbreak();
}
while let Some(ref cmnt) = self.next_comment() {
self.print_comment(cmnt)
}
}
pub fn print_opt_abi_and_extern_if_nondefault(&mut self,
opt_abi: Option<Abi>)
{
match opt_abi {
Some(Abi::Rust) => {},
Some(abi) => {
self.word_nbsp("extern");
self.word_nbsp(abi.to_string())
}
None => {},
}
}
pub fn print_extern_opt_abi(&mut self, opt_abi: Option<Abi>) {
match opt_abi {
Some(abi) => {
self.word_nbsp("extern");
self.word_nbsp(abi.to_string())
}
None => {},
}
}
pub fn print_fn_header_info(&mut self,
header: hir::FnHeader,
vis: &hir::Visibility)
{
self.s.word(visibility_qualified(vis, ""));
match header.constness {
hir::Constness::NotConst => {}
hir::Constness::Const => self.word_nbsp("const"),
}
match header.asyncness {
hir::IsAsync::NotAsync => {}
hir::IsAsync::Async => self.word_nbsp("async"),
}
self.print_unsafety(header.unsafety);
if header.abi != Abi::Rust {
self.word_nbsp("extern");
self.word_nbsp(header.abi.to_string());
}
self.s.word("fn")
}
pub fn print_unsafety(&mut self, s: hir::Unsafety) {
match s {
hir::Unsafety::Normal => {}
hir::Unsafety::Unsafe => self.word_nbsp("unsafe"),
}
}
pub fn print_is_auto(&mut self, s: hir::IsAuto) {
match s {
hir::IsAuto::Yes => self.word_nbsp("auto"),
hir::IsAuto::No => {},
}
}
}
// Dup'ed from parse::classify, but adapted for the HIR.
/// Does this expression require a semicolon to be treated
/// as a statement? The negation of this: 'can this expression
/// be used as a statement without a semicolon' -- is used
/// as an early-bail-out in the parser so that, for instance,
/// if true {...} else {...}
/// |x| 5
/// isn't parsed as (if true {...} else {...} | x) | 5
fn expr_requires_semi_to_be_stmt(e: &hir::Expr) -> bool {
match e.node {
hir::ExprKind::Match(..) |
hir::ExprKind::Block(..) |
hir::ExprKind::Loop(..) => false,
_ => true,
}
}
/// this statement requires a semicolon after it.
/// note that in one case (stmt_semi), we've already
/// seen the semicolon, and thus don't need another.
fn stmt_ends_with_semi(stmt: &hir::StmtKind) -> bool {
match *stmt {
hir::StmtKind::Local(_) => true,
hir::StmtKind::Item(_) => false,
hir::StmtKind::Expr(ref e) => expr_requires_semi_to_be_stmt(&e),
hir::StmtKind::Semi(..) => false,
}
}
fn bin_op_to_assoc_op(op: hir::BinOpKind) -> AssocOp {
use crate::hir::BinOpKind::*;
match op {
Add => AssocOp::Add,
Sub => AssocOp::Subtract,
Mul => AssocOp::Multiply,
Div => AssocOp::Divide,
Rem => AssocOp::Modulus,
And => AssocOp::LAnd,
Or => AssocOp::LOr,
BitXor => AssocOp::BitXor,
BitAnd => AssocOp::BitAnd,
BitOr => AssocOp::BitOr,
Shl => AssocOp::ShiftLeft,
Shr => AssocOp::ShiftRight,
Eq => AssocOp::Equal,
Lt => AssocOp::Less,
Le => AssocOp::LessEqual,
Ne => AssocOp::NotEqual,
Ge => AssocOp::GreaterEqual,
Gt => AssocOp::Greater,
}
}
/// Expressions that syntactically contain an "exterior" struct literal i.e., not surrounded by any
/// parens or other delimiters, e.g., `X { y: 1 }`, `X { y: 1 }.method()`, `foo == X { y: 1 }` and
/// `X { y: 1 } == foo` all do, but `(X { y: 1 }) == foo` does not.
fn contains_exterior_struct_lit(value: &hir::Expr) -> bool {
match value.node {
hir::ExprKind::Struct(..) => true,
hir::ExprKind::Assign(ref lhs, ref rhs) |
hir::ExprKind::AssignOp(_, ref lhs, ref rhs) |
hir::ExprKind::Binary(_, ref lhs, ref rhs) => {
// X { y: 1 } + X { y: 2 }
contains_exterior_struct_lit(&lhs) || contains_exterior_struct_lit(&rhs)
}
hir::ExprKind::Unary(_, ref x) |
hir::ExprKind::Cast(ref x, _) |
hir::ExprKind::Type(ref x, _) |
hir::ExprKind::Field(ref x, _) |
hir::ExprKind::Index(ref x, _) => {
// &X { y: 1 }, X { y: 1 }.y
contains_exterior_struct_lit(&x)
}
hir::ExprKind::MethodCall(.., ref exprs) => {
// X { y: 1 }.bar(...)
contains_exterior_struct_lit(&exprs[0])
}
_ => false,
}
}