Google Git
Sign in
rust / rust-lang / rust / refs/heads/master / . / compiler / rustc_middle / src / ty / print / pretty.rs
blob: 4d1fcaeda5e26d462769d538eba309dba2d88596 [file] [log] [blame]
use std::cell::Cell;
use std::fmt::{self, Write as _};
use std::iter;
use std::ops::{Deref, DerefMut};
use rustc_abi::{ExternAbi, Size};
use rustc_apfloat::Float;
use rustc_apfloat::ieee::{Double, Half, Quad, Single};
use rustc_data_structures::fx::{FxIndexMap, IndexEntry};
use rustc_data_structures::unord::UnordMap;
use rustc_hir as hir;
use rustc_hir::LangItem;
use rustc_hir::def::{self, CtorKind, DefKind, Namespace};
use rustc_hir::def_id::{DefIdMap, DefIdSet, LOCAL_CRATE, ModDefId};
use rustc_hir::definitions::{DefKey, DefPathDataName};
use rustc_hir::limit::Limit;
use rustc_macros::{Lift, extension};
use rustc_session::cstore::{ExternCrate, ExternCrateSource};
use rustc_span::{FileNameDisplayPreference, Ident, Symbol, kw, sym};
use rustc_type_ir::{Upcast as _, elaborate};
use smallvec::SmallVec;
// `pretty` is a separate module only for organization.
use super::*;
use crate::mir::interpret::{AllocRange, GlobalAlloc, Pointer, Provenance, Scalar};
use crate::query::{IntoQueryParam, Providers};
use crate::ty::{
ConstInt, Expr, GenericArgKind, ParamConst, ScalarInt, Term, TermKind, TraitPredicate,
TypeFoldable, TypeSuperFoldable, TypeSuperVisitable, TypeVisitable, TypeVisitableExt,
};
thread_local! {
static FORCE_IMPL_FILENAME_LINE: Cell<bool> = const { Cell::new(false) };
static SHOULD_PREFIX_WITH_CRATE: Cell<bool> = const { Cell::new(false) };
static NO_TRIMMED_PATH: Cell<bool> = const { Cell::new(false) };
static FORCE_TRIMMED_PATH: Cell<bool> = const { Cell::new(false) };
static REDUCED_QUERIES: Cell<bool> = const { Cell::new(false) };
static NO_VISIBLE_PATH: Cell<bool> = const { Cell::new(false) };
static NO_VISIBLE_PATH_IF_DOC_HIDDEN: Cell<bool> = const { Cell::new(false) };
static RTN_MODE: Cell<RtnMode> = const { Cell::new(RtnMode::ForDiagnostic) };
}
/// Rendering style for RTN types.
#[derive(Copy, Clone, PartialEq, Eq, Debug)]
pub enum RtnMode {
/// Print the RTN type as an impl trait with its path, i.e.e `impl Sized { T::method(..) }`.
ForDiagnostic,
/// Print the RTN type as an impl trait, i.e. `impl Sized`.
ForSignature,
/// Print the RTN type as a value path, i.e. `T::method(..): ...`.
ForSuggestion,
}
macro_rules! define_helper {
($($(#[$a:meta])* fn $name:ident($helper:ident, $tl:ident);)+) => {
$(
#[must_use]
pub struct $helper(bool);
impl $helper {
pub fn new() -> $helper {
$helper($tl.replace(true))
}
}
$(#[$a])*
pub macro $name($e:expr) {
{
let _guard = $helper::new();
$e
}
}
impl Drop for $helper {
fn drop(&mut self) {
$tl.set(self.0)
}
}
pub fn $name() -> bool {
$tl.get()
}
)+
}
}
define_helper!(
/// Avoids running select queries during any prints that occur
/// during the closure. This may alter the appearance of some
/// types (e.g. forcing verbose printing for opaque types).
/// This method is used during some queries (e.g. `explicit_item_bounds`
/// for opaque types), to ensure that any debug printing that
/// occurs during the query computation does not end up recursively
/// calling the same query.
fn with_reduced_queries(ReducedQueriesGuard, REDUCED_QUERIES);
/// Force us to name impls with just the filename/line number. We
/// normally try to use types. But at some points, notably while printing
/// cycle errors, this can result in extra or suboptimal error output,
/// so this variable disables that check.
fn with_forced_impl_filename_line(ForcedImplGuard, FORCE_IMPL_FILENAME_LINE);
/// Adds the `crate::` prefix to paths where appropriate.
fn with_crate_prefix(CratePrefixGuard, SHOULD_PREFIX_WITH_CRATE);
/// Prevent path trimming if it is turned on. Path trimming affects `Display` impl
/// of various rustc types, for example `std::vec::Vec` would be trimmed to `Vec`,
/// if no other `Vec` is found.
fn with_no_trimmed_paths(NoTrimmedGuard, NO_TRIMMED_PATH);
fn with_forced_trimmed_paths(ForceTrimmedGuard, FORCE_TRIMMED_PATH);
/// Prevent selection of visible paths. `Display` impl of DefId will prefer
/// visible (public) reexports of types as paths.
fn with_no_visible_paths(NoVisibleGuard, NO_VISIBLE_PATH);
/// Prevent selection of visible paths if the paths are through a doc hidden path.
fn with_no_visible_paths_if_doc_hidden(NoVisibleIfDocHiddenGuard, NO_VISIBLE_PATH_IF_DOC_HIDDEN);
);
#[must_use]
pub struct RtnModeHelper(RtnMode);
impl RtnModeHelper {
pub fn with(mode: RtnMode) -> RtnModeHelper {
RtnModeHelper(RTN_MODE.with(|c| c.replace(mode)))
}
}
impl Drop for RtnModeHelper {
fn drop(&mut self) {
RTN_MODE.with(|c| c.set(self.0))
}
}
/// Print types for the purposes of a suggestion.
///
/// Specifically, this will render RPITITs as `T::method(..)` which is suitable for
/// things like where-clauses.
pub macro with_types_for_suggestion($e:expr) {{
let _guard = $crate::ty::print::pretty::RtnModeHelper::with(RtnMode::ForSuggestion);
$e
}}
/// Print types for the purposes of a signature suggestion.
///
/// Specifically, this will render RPITITs as `impl Trait` rather than `T::method(..)`.
pub macro with_types_for_signature($e:expr) {{
let _guard = $crate::ty::print::pretty::RtnModeHelper::with(RtnMode::ForSignature);
$e
}}
/// Avoids running any queries during prints.
pub macro with_no_queries($e:expr) {{
$crate::ty::print::with_reduced_queries!($crate::ty::print::with_forced_impl_filename_line!(
$crate::ty::print::with_no_trimmed_paths!($crate::ty::print::with_no_visible_paths!(
$crate::ty::print::with_forced_impl_filename_line!($e)
))
))
}}
#[derive(Copy, Clone, Debug, PartialEq, Eq)]
pub enum WrapBinderMode {
ForAll,
Unsafe,
}
impl WrapBinderMode {
pub fn start_str(self) -> &'static str {
match self {
WrapBinderMode::ForAll => "for<",
WrapBinderMode::Unsafe => "unsafe<",
}
}
}
/// The "region highlights" are used to control region printing during
/// specific error messages. When a "region highlight" is enabled, it
/// gives an alternate way to print specific regions. For now, we
/// always print those regions using a number, so something like "`'0`".
///
/// Regions not selected by the region highlight mode are presently
/// unaffected.
#[derive(Copy, Clone, Default)]
pub struct RegionHighlightMode<'tcx> {
/// If enabled, when we see the selected region, use "`'N`"
/// instead of the ordinary behavior.
highlight_regions: [Option<(ty::Region<'tcx>, usize)>; 3],
/// If enabled, when printing a "free region" that originated from
/// the given `ty::BoundRegionKind`, print it as "`'1`". Free regions that would ordinarily
/// have names print as normal.
///
/// This is used when you have a signature like `fn foo(x: &u32,
/// y: &'a u32)` and we want to give a name to the region of the
/// reference `x`.
highlight_bound_region: Option<(ty::BoundRegionKind, usize)>,
}
impl<'tcx> RegionHighlightMode<'tcx> {
/// If `region` and `number` are both `Some`, invokes
/// `highlighting_region`.
pub fn maybe_highlighting_region(
&mut self,
region: Option<ty::Region<'tcx>>,
number: Option<usize>,
) {
if let Some(k) = region
&& let Some(n) = number
{
self.highlighting_region(k, n);
}
}
/// Highlights the region inference variable `vid` as `'N`.
pub fn highlighting_region(&mut self, region: ty::Region<'tcx>, number: usize) {
let num_slots = self.highlight_regions.len();
let first_avail_slot =
self.highlight_regions.iter_mut().find(|s| s.is_none()).unwrap_or_else(|| {
bug!("can only highlight {} placeholders at a time", num_slots,)
});
*first_avail_slot = Some((region, number));
}
/// Convenience wrapper for `highlighting_region`.
pub fn highlighting_region_vid(
&mut self,
tcx: TyCtxt<'tcx>,
vid: ty::RegionVid,
number: usize,
) {
self.highlighting_region(ty::Region::new_var(tcx, vid), number)
}
/// Returns `Some(n)` with the number to use for the given region, if any.
fn region_highlighted(&self, region: ty::Region<'tcx>) -> Option<usize> {
self.highlight_regions.iter().find_map(|h| match h {
Some((r, n)) if *r == region => Some(*n),
_ => None,
})
}
/// Highlight the given bound region.
/// We can only highlight one bound region at a time. See
/// the field `highlight_bound_region` for more detailed notes.
pub fn highlighting_bound_region(&mut self, br: ty::BoundRegionKind, number: usize) {
assert!(self.highlight_bound_region.is_none());
self.highlight_bound_region = Some((br, number));
}
}
/// Trait for printers that pretty-print using `fmt::Write` to the printer.
pub trait PrettyPrinter<'tcx>: Printer<'tcx> + fmt::Write {
/// Like `print_def_path` but for value paths.
fn pretty_print_value_path(
&mut self,
def_id: DefId,
args: &'tcx [GenericArg<'tcx>],
) -> Result<(), PrintError> {
self.print_def_path(def_id, args)
}
fn pretty_print_in_binder<T>(&mut self, value: &ty::Binder<'tcx, T>) -> Result<(), PrintError>
where
T: Print<'tcx, Self> + TypeFoldable<TyCtxt<'tcx>>,
{
value.as_ref().skip_binder().print(self)
}
fn wrap_binder<T, F: FnOnce(&T, &mut Self) -> Result<(), fmt::Error>>(
&mut self,
value: &ty::Binder<'tcx, T>,
_mode: WrapBinderMode,
f: F,
) -> Result<(), PrintError>
where
T: TypeFoldable<TyCtxt<'tcx>>,
{
f(value.as_ref().skip_binder(), self)
}
/// Prints comma-separated elements.
fn comma_sep<T>(&mut self, mut elems: impl Iterator<Item = T>) -> Result<(), PrintError>
where
T: Print<'tcx, Self>,
{
if let Some(first) = elems.next() {
first.print(self)?;
for elem in elems {
self.write_str(", ")?;
elem.print(self)?;
}
}
Ok(())
}
/// Prints `{f: t}` or `{f as t}` depending on the `cast` argument
fn typed_value(
&mut self,
f: impl FnOnce(&mut Self) -> Result<(), PrintError>,
t: impl FnOnce(&mut Self) -> Result<(), PrintError>,
conversion: &str,
) -> Result<(), PrintError> {
self.write_str("{")?;
f(self)?;
self.write_str(conversion)?;
t(self)?;
self.write_str("}")?;
Ok(())
}
/// Prints `(...)` around what `f` prints.
fn parenthesized(
&mut self,
f: impl FnOnce(&mut Self) -> Result<(), PrintError>,
) -> Result<(), PrintError> {
self.write_str("(")?;
f(self)?;
self.write_str(")")?;
Ok(())
}
/// Prints `(...)` around what `f` prints if `parenthesized` is true, otherwise just prints `f`.
fn maybe_parenthesized(
&mut self,
f: impl FnOnce(&mut Self) -> Result<(), PrintError>,
parenthesized: bool,
) -> Result<(), PrintError> {
if parenthesized {
self.parenthesized(f)?;
} else {
f(self)?;
}
Ok(())
}
/// Prints `<...>` around what `f` prints.
fn generic_delimiters(
&mut self,
f: impl FnOnce(&mut Self) -> Result<(), PrintError>,
) -> Result<(), PrintError>;
fn should_truncate(&mut self) -> bool {
false
}
/// Returns `true` if the region should be printed in optional positions,
/// e.g., `&'a T` or `dyn Tr + 'b`. (Regions like the one in `Cow<'static, T>`
/// will always be printed.)
fn should_print_optional_region(&self, region: ty::Region<'tcx>) -> bool;
fn reset_type_limit(&mut self) {}
// Defaults (should not be overridden):
/// If possible, this returns a global path resolving to `def_id` that is visible
/// from at least one local module, and returns `true`. If the crate defining `def_id` is
/// declared with an `extern crate`, the path is guaranteed to use the `extern crate`.
fn try_print_visible_def_path(&mut self, def_id: DefId) -> Result<bool, PrintError> {
if with_no_visible_paths() {
return Ok(false);
}
let mut callers = Vec::new();
self.try_print_visible_def_path_recur(def_id, &mut callers)
}
// Given a `DefId`, produce a short name. For types and traits, it prints *only* its name,
// For associated items on traits it prints out the trait's name and the associated item's name.
// For enum variants, if they have an unique name, then we only print the name, otherwise we
// print the enum name and the variant name. Otherwise, we do not print anything and let the
// caller use the `print_def_path` fallback.
fn force_print_trimmed_def_path(&mut self, def_id: DefId) -> Result<bool, PrintError> {
let key = self.tcx().def_key(def_id);
let visible_parent_map = self.tcx().visible_parent_map(());
let kind = self.tcx().def_kind(def_id);
let get_local_name = |this: &Self, name, def_id, key: DefKey| {
if let Some(visible_parent) = visible_parent_map.get(&def_id)
&& let actual_parent = this.tcx().opt_parent(def_id)
&& let DefPathData::TypeNs(_) = key.disambiguated_data.data
&& Some(*visible_parent) != actual_parent
{
this.tcx()
// FIXME(typed_def_id): Further propagate ModDefId
.module_children(ModDefId::new_unchecked(*visible_parent))
.iter()
.filter(|child| child.res.opt_def_id() == Some(def_id))
.find(|child| child.vis.is_public() && child.ident.name != kw::Underscore)
.map(|child| child.ident.name)
.unwrap_or(name)
} else {
name
}
};
if let DefKind::Variant = kind
&& let Some(symbol) = self.tcx().trimmed_def_paths(()).get(&def_id)
{
// If `Assoc` is unique, we don't want to talk about `Trait::Assoc`.
self.write_str(get_local_name(self, *symbol, def_id, key).as_str())?;
return Ok(true);
}
if let Some(symbol) = key.get_opt_name() {
if let DefKind::AssocConst | DefKind::AssocFn | DefKind::AssocTy = kind
&& let Some(parent) = self.tcx().opt_parent(def_id)
&& let parent_key = self.tcx().def_key(parent)
&& let Some(symbol) = parent_key.get_opt_name()
{
// Trait
self.write_str(get_local_name(self, symbol, parent, parent_key).as_str())?;
self.write_str("::")?;
} else if let DefKind::Variant = kind
&& let Some(parent) = self.tcx().opt_parent(def_id)
&& let parent_key = self.tcx().def_key(parent)
&& let Some(symbol) = parent_key.get_opt_name()
{
// Enum
// For associated items and variants, we want the "full" path, namely, include
// the parent type in the path. For example, `Iterator::Item`.
self.write_str(get_local_name(self, symbol, parent, parent_key).as_str())?;
self.write_str("::")?;
} else if let DefKind::Struct
| DefKind::Union
| DefKind::Enum
| DefKind::Trait
| DefKind::TyAlias
| DefKind::Fn
| DefKind::Const
| DefKind::Static { .. } = kind
{
} else {
// If not covered above, like for example items out of `impl` blocks, fallback.
return Ok(false);
}
self.write_str(get_local_name(self, symbol, def_id, key).as_str())?;
return Ok(true);
}
Ok(false)
}
/// Try to see if this path can be trimmed to a unique symbol name.
fn try_print_trimmed_def_path(&mut self, def_id: DefId) -> Result<bool, PrintError> {
if with_forced_trimmed_paths() && self.force_print_trimmed_def_path(def_id)? {
return Ok(true);
}
if self.tcx().sess.opts.unstable_opts.trim_diagnostic_paths
&& self.tcx().sess.opts.trimmed_def_paths
&& !with_no_trimmed_paths()
&& !with_crate_prefix()
&& let Some(symbol) = self.tcx().trimmed_def_paths(()).get(&def_id)
{
write!(self, "{}", Ident::with_dummy_span(*symbol))?;
Ok(true)
} else {
Ok(false)
}
}
/// Does the work of `try_print_visible_def_path`, building the
/// full definition path recursively before attempting to
/// post-process it into the valid and visible version that
/// accounts for re-exports.
///
/// This method should only be called by itself or
/// `try_print_visible_def_path`.
///
/// `callers` is a chain of visible_parent's leading to `def_id`,
/// to support cycle detection during recursion.
///
/// This method returns false if we can't print the visible path, so
/// `print_def_path` can fall back on the item's real definition path.
fn try_print_visible_def_path_recur(
&mut self,
def_id: DefId,
callers: &mut Vec<DefId>,
) -> Result<bool, PrintError> {
debug!("try_print_visible_def_path: def_id={:?}", def_id);
// If `def_id` is a direct or injected extern crate, return the
// path to the crate followed by the path to the item within the crate.
if let Some(cnum) = def_id.as_crate_root() {
if cnum == LOCAL_CRATE {
self.print_crate_name(cnum)?;
return Ok(true);
}
// In local mode, when we encounter a crate other than
// LOCAL_CRATE, execution proceeds in one of two ways:
//
// 1. For a direct dependency, where user added an
// `extern crate` manually, we put the `extern
// crate` as the parent. So you wind up with
// something relative to the current crate.
// 2. For an extern inferred from a path or an indirect crate,
// where there is no explicit `extern crate`, we just prepend
// the crate name.
match self.tcx().extern_crate(cnum) {
Some(&ExternCrate { src, dependency_of, span, .. }) => match (src, dependency_of) {
(ExternCrateSource::Extern(def_id), LOCAL_CRATE) => {
// NOTE(eddyb) the only reason `span` might be dummy,
// that we're aware of, is that it's the `std`/`core`
// `extern crate` injected by default.
// FIXME(eddyb) find something better to key this on,
// or avoid ending up with `ExternCrateSource::Extern`,
// for the injected `std`/`core`.
if span.is_dummy() {
self.print_crate_name(cnum)?;
return Ok(true);
}
// Disable `try_print_trimmed_def_path` behavior within
// the `print_def_path` call, to avoid infinite recursion
// in cases where the `extern crate foo` has non-trivial
// parents, e.g. it's nested in `impl foo::Trait for Bar`
// (see also issues #55779 and #87932).
with_no_visible_paths!(self.print_def_path(def_id, &[])?);
return Ok(true);
}
(ExternCrateSource::Path, LOCAL_CRATE) => {
self.print_crate_name(cnum)?;
return Ok(true);
}
_ => {}
},
None => {
self.print_crate_name(cnum)?;
return Ok(true);
}
}
}
if def_id.is_local() {
return Ok(false);
}
let visible_parent_map = self.tcx().visible_parent_map(());
let mut cur_def_key = self.tcx().def_key(def_id);
debug!("try_print_visible_def_path: cur_def_key={:?}", cur_def_key);
// For a constructor, we want the name of its parent rather than <unnamed>.
if let DefPathData::Ctor = cur_def_key.disambiguated_data.data {
let parent = DefId {
krate: def_id.krate,
index: cur_def_key
.parent
.expect("`DefPathData::Ctor` / `VariantData` missing a parent"),
};
cur_def_key = self.tcx().def_key(parent);
}
let Some(visible_parent) = visible_parent_map.get(&def_id).cloned() else {
return Ok(false);
};
if self.tcx().is_doc_hidden(visible_parent) && with_no_visible_paths_if_doc_hidden() {
return Ok(false);
}
let actual_parent = self.tcx().opt_parent(def_id);
debug!(
"try_print_visible_def_path: visible_parent={:?} actual_parent={:?}",
visible_parent, actual_parent,
);
let mut data = cur_def_key.disambiguated_data.data;
debug!(
"try_print_visible_def_path: data={:?} visible_parent={:?} actual_parent={:?}",
data, visible_parent, actual_parent,
);
match data {
// In order to output a path that could actually be imported (valid and visible),
// we need to handle re-exports correctly.
//
// For example, take `std::os::unix::process::CommandExt`, this trait is actually
// defined at `std::sys::unix::ext::process::CommandExt` (at time of writing).
//
// `std::os::unix` reexports the contents of `std::sys::unix::ext`. `std::sys` is
// private so the "true" path to `CommandExt` isn't accessible.
//
// In this case, the `visible_parent_map` will look something like this:
//
// (child) -> (parent)
// `std::sys::unix::ext::process::CommandExt` -> `std::sys::unix::ext::process`
// `std::sys::unix::ext::process` -> `std::sys::unix::ext`
// `std::sys::unix::ext` -> `std::os`
//
// This is correct, as the visible parent of `std::sys::unix::ext` is in fact
// `std::os`.
//
// When printing the path to `CommandExt` and looking at the `cur_def_key` that
// corresponds to `std::sys::unix::ext`, we would normally print `ext` and then go
// to the parent - resulting in a mangled path like
// `std::os::ext::process::CommandExt`.
//
// Instead, we must detect that there was a re-export and instead print `unix`
// (which is the name `std::sys::unix::ext` was re-exported as in `std::os`). To
// do this, we compare the parent of `std::sys::unix::ext` (`std::sys::unix`) with
// the visible parent (`std::os`). If these do not match, then we iterate over
// the children of the visible parent (as was done when computing
// `visible_parent_map`), looking for the specific child we currently have and then
// have access to the re-exported name.
DefPathData::TypeNs(ref mut name) if Some(visible_parent) != actual_parent => {
// Item might be re-exported several times, but filter for the one
// that's public and whose identifier isn't `_`.
let reexport = self
.tcx()
// FIXME(typed_def_id): Further propagate ModDefId
.module_children(ModDefId::new_unchecked(visible_parent))
.iter()
.filter(|child| child.res.opt_def_id() == Some(def_id))
.find(|child| child.vis.is_public() && child.ident.name != kw::Underscore)
.map(|child| child.ident.name);
if let Some(new_name) = reexport {
*name = new_name;
} else {
// There is no name that is public and isn't `_`, so bail.
return Ok(false);
}
}
// Re-exported `extern crate` (#43189).
DefPathData::CrateRoot => {
data = DefPathData::TypeNs(self.tcx().crate_name(def_id.krate));
}
_ => {}
}
debug!("try_print_visible_def_path: data={:?}", data);
if callers.contains(&visible_parent) {
return Ok(false);
}
callers.push(visible_parent);
// HACK(eddyb) this bypasses `print_path_with_simple`'s prefix printing to avoid
// knowing ahead of time whether the entire path will succeed or not.
// To support printers that do not implement `PrettyPrinter`, a `Vec` or
// linked list on the stack would need to be built, before any printing.
match self.try_print_visible_def_path_recur(visible_parent, callers)? {
false => return Ok(false),
true => {}
}
callers.pop();
self.print_path_with_simple(
|_| Ok(()),
&DisambiguatedDefPathData { data, disambiguator: 0 },
)?;
Ok(true)
}
fn pretty_print_path_with_qualified(
&mut self,
self_ty: Ty<'tcx>,
trait_ref: Option<ty::TraitRef<'tcx>>,
) -> Result<(), PrintError> {
if trait_ref.is_none() {
// Inherent impls. Try to print `Foo::bar` for an inherent
// impl on `Foo`, but fallback to `<Foo>::bar` if self-type is
// anything other than a simple path.
match self_ty.kind() {
ty::Adt(..)
| ty::Foreign(_)
| ty::Bool
| ty::Char
| ty::Str
| ty::Int(_)
| ty::Uint(_)
| ty::Float(_) => {
return self_ty.print(self);
}
_ => {}
}
}
self.generic_delimiters(|p| {
self_ty.print(p)?;
if let Some(trait_ref) = trait_ref {
write!(p, " as ")?;
trait_ref.print_only_trait_path().print(p)?;
}
Ok(())
})
}
fn pretty_print_path_with_impl(
&mut self,
print_prefix: impl FnOnce(&mut Self) -> Result<(), PrintError>,
self_ty: Ty<'tcx>,
trait_ref: Option<ty::TraitRef<'tcx>>,
) -> Result<(), PrintError> {
print_prefix(self)?;
self.generic_delimiters(|p| {
write!(p, "impl ")?;
if let Some(trait_ref) = trait_ref {
trait_ref.print_only_trait_path().print(p)?;
write!(p, " for ")?;
}
self_ty.print(p)?;
Ok(())
})
}
fn pretty_print_type(&mut self, ty: Ty<'tcx>) -> Result<(), PrintError> {
match *ty.kind() {
ty::Bool => write!(self, "bool")?,
ty::Char => write!(self, "char")?,
ty::Int(t) => write!(self, "{}", t.name_str())?,
ty::Uint(t) => write!(self, "{}", t.name_str())?,
ty::Float(t) => write!(self, "{}", t.name_str())?,
ty::Pat(ty, pat) => {
write!(self, "(")?;
ty.print(self)?;
write!(self, ") is {pat:?}")?;
}
ty::RawPtr(ty, mutbl) => {
write!(self, "*{} ", mutbl.ptr_str())?;
ty.print(self)?;
}
ty::Ref(r, ty, mutbl) => {
write!(self, "&")?;
if self.should_print_optional_region(r) {
r.print(self)?;
write!(self, " ")?;
}
ty::TypeAndMut { ty, mutbl }.print(self)?;
}
ty::Never => write!(self, "!")?,
ty::Tuple(tys) => {
write!(self, "(")?;
self.comma_sep(tys.iter())?;
if tys.len() == 1 {
write!(self, ",")?;
}
write!(self, ")")?;
}
ty::FnDef(def_id, args) => {
if with_reduced_queries() {
self.print_def_path(def_id, args)?;
} else {
let mut sig = self.tcx().fn_sig(def_id).instantiate(self.tcx(), args);
if self.tcx().codegen_fn_attrs(def_id).safe_target_features {
write!(self, "#[target_features] ")?;
sig = sig.map_bound(|mut sig| {
sig.safety = hir::Safety::Safe;
sig
});
}
sig.print(self)?;
write!(self, " {{")?;
self.pretty_print_value_path(def_id, args)?;
write!(self, "}}")?;
}
}
ty::FnPtr(ref sig_tys, hdr) => sig_tys.with(hdr).print(self)?,
ty::UnsafeBinder(ref bound_ty) => {
self.wrap_binder(bound_ty, WrapBinderMode::Unsafe, |ty, p| {
p.pretty_print_type(*ty)
})?;
}
ty::Infer(infer_ty) => {
if self.should_print_verbose() {
write!(self, "{:?}", ty.kind())?;
return Ok(());
}
if let ty::TyVar(ty_vid) = infer_ty {
if let Some(name) = self.ty_infer_name(ty_vid) {
write!(self, "{name}")?;
} else {
write!(self, "{infer_ty}")?;
}
} else {
write!(self, "{infer_ty}")?;
}
}
ty::Error(_) => write!(self, "{{type error}}")?,
ty::Param(ref param_ty) => param_ty.print(self)?,
ty::Bound(debruijn, bound_ty) => match bound_ty.kind {
ty::BoundTyKind::Anon => {
rustc_type_ir::debug_bound_var(self, debruijn, bound_ty.var)?
}
ty::BoundTyKind::Param(def_id) => match self.should_print_verbose() {
true => write!(self, "{:?}", ty.kind())?,
false => write!(self, "{}", self.tcx().item_name(def_id))?,
},
},
ty::Adt(def, args) => self.print_def_path(def.did(), args)?,
ty::Dynamic(data, r) => {
let print_r = self.should_print_optional_region(r);
if print_r {
write!(self, "(")?;
}
write!(self, "dyn ")?;
data.print(self)?;
if print_r {
write!(self, " + ")?;
r.print(self)?;
write!(self, ")")?;
}
}
ty::Foreign(def_id) => self.print_def_path(def_id, &[])?,
ty::Alias(ty::Projection | ty::Inherent | ty::Free, ref data) => data.print(self)?,
ty::Placeholder(placeholder) => placeholder.print(self)?,
ty::Alias(ty::Opaque, ty::AliasTy { def_id, args, .. }) => {
// We use verbose printing in 'NO_QUERIES' mode, to
// avoid needing to call `predicates_of`. This should
// only affect certain debug messages (e.g. messages printed
// from `rustc_middle::ty` during the computation of `tcx.predicates_of`),
// and should have no effect on any compiler output.
// [Unless `-Zverbose-internals` is used, e.g. in the output of
// `tests/ui/nll/ty-outlives/impl-trait-captures.rs`, for
// example.]
if self.should_print_verbose() {
// FIXME(eddyb) print this with `print_def_path`.
write!(self, "Opaque({:?}, {})", def_id, args.print_as_list())?;
return Ok(());
}
let parent = self.tcx().parent(def_id);
match self.tcx().def_kind(parent) {
DefKind::TyAlias | DefKind::AssocTy => {
// NOTE: I know we should check for NO_QUERIES here, but it's alright.
// `type_of` on a type alias or assoc type should never cause a cycle.
if let ty::Alias(ty::Opaque, ty::AliasTy { def_id: d, .. }) =
*self.tcx().type_of(parent).instantiate_identity().kind()
{
if d == def_id {
// If the type alias directly starts with the `impl` of the
// opaque type we're printing, then skip the `::{opaque#1}`.
self.print_def_path(parent, args)?;
return Ok(());
}
}
// Complex opaque type, e.g. `type Foo = (i32, impl Debug);`
self.print_def_path(def_id, args)?;
return Ok(());
}
_ => {
if with_reduced_queries() {
self.print_def_path(def_id, &[])?;
return Ok(());
} else {
return self.pretty_print_opaque_impl_type(def_id, args);
}
}
}
}
ty::Str => write!(self, "str")?,
ty::Coroutine(did, args) => {
write!(self, "{{")?;
let coroutine_kind = self.tcx().coroutine_kind(did).unwrap();
let should_print_movability = self.should_print_verbose()
|| matches!(coroutine_kind, hir::CoroutineKind::Coroutine(_));
if should_print_movability {
match coroutine_kind.movability() {
hir::Movability::Movable => {}
hir::Movability::Static => write!(self, "static ")?,
}
}
if !self.should_print_verbose() {
write!(self, "{coroutine_kind}")?;
if coroutine_kind.is_fn_like() {
// If we are printing an `async fn` coroutine type, then give the path
// of the fn, instead of its span, because that will in most cases be
// more helpful for the reader than just a source location.
//
// This will look like:
// {async fn body of some_fn()}
let did_of_the_fn_item = self.tcx().parent(did);
write!(self, " of ")?;
self.print_def_path(did_of_the_fn_item, args)?;
write!(self, "()")?;
} else if let Some(local_did) = did.as_local() {
let span = self.tcx().def_span(local_did);
write!(
self,
"@{}",
// This may end up in stderr diagnostics but it may also be emitted
// into MIR. Hence we use the remapped path if available
self.tcx().sess.source_map().span_to_embeddable_string(span)
)?;
} else {
write!(self, "@")?;
self.print_def_path(did, args)?;
}
} else {
self.print_def_path(did, args)?;
write!(self, " upvar_tys=")?;
args.as_coroutine().tupled_upvars_ty().print(self)?;
write!(self, " resume_ty=")?;
args.as_coroutine().resume_ty().print(self)?;
write!(self, " yield_ty=")?;
args.as_coroutine().yield_ty().print(self)?;
write!(self, " return_ty=")?;
args.as_coroutine().return_ty().print(self)?;
}
write!(self, "}}")?
}
ty::CoroutineWitness(did, args) => {
write!(self, "{{")?;
if !self.tcx().sess.verbose_internals() {
write!(self, "coroutine witness")?;
if let Some(did) = did.as_local() {
let span = self.tcx().def_span(did);
write!(
self,
"@{}",
// This may end up in stderr diagnostics but it may also be emitted
// into MIR. Hence we use the remapped path if available
self.tcx().sess.source_map().span_to_embeddable_string(span)
)?;
} else {
write!(self, "@")?;
self.print_def_path(did, args)?;
}
} else {
self.print_def_path(did, args)?;
}
write!(self, "}}")?
}
ty::Closure(did, args) => {
write!(self, "{{")?;
if !self.should_print_verbose() {
write!(self, "closure")?;
if self.should_truncate() {
write!(self, "@...}}")?;
return Ok(());
} else {
if let Some(did) = did.as_local() {
if self.tcx().sess.opts.unstable_opts.span_free_formats {
write!(self, "@")?;
self.print_def_path(did.to_def_id(), args)?;
} else {
let span = self.tcx().def_span(did);
let preference = if with_forced_trimmed_paths() {
FileNameDisplayPreference::Short
} else {
FileNameDisplayPreference::Remapped
};
write!(
self,
"@{}",
// This may end up in stderr diagnostics but it may also be
// emitted into MIR. Hence we use the remapped path if
// available
self.tcx().sess.source_map().span_to_string(span, preference)
)?;
}
} else {
write!(self, "@")?;
self.print_def_path(did, args)?;
}
}
} else {
self.print_def_path(did, args)?;
write!(self, " closure_kind_ty=")?;
args.as_closure().kind_ty().print(self)?;
write!(self, " closure_sig_as_fn_ptr_ty=")?;
args.as_closure().sig_as_fn_ptr_ty().print(self)?;
write!(self, " upvar_tys=")?;
args.as_closure().tupled_upvars_ty().print(self)?;
}
write!(self, "}}")?;
}
ty::CoroutineClosure(did, args) => {
write!(self, "{{")?;
if !self.should_print_verbose() {
match self.tcx().coroutine_kind(self.tcx().coroutine_for_closure(did)).unwrap()
{
hir::CoroutineKind::Desugared(
hir::CoroutineDesugaring::Async,
hir::CoroutineSource::Closure,
) => write!(self, "async closure")?,
hir::CoroutineKind::Desugared(
hir::CoroutineDesugaring::AsyncGen,
hir::CoroutineSource::Closure,
) => write!(self, "async gen closure")?,
hir::CoroutineKind::Desugared(
hir::CoroutineDesugaring::Gen,
hir::CoroutineSource::Closure,
) => write!(self, "gen closure")?,
_ => unreachable!(
"coroutine from coroutine-closure should have CoroutineSource::Closure"
),
}
if let Some(did) = did.as_local() {
if self.tcx().sess.opts.unstable_opts.span_free_formats {
write!(self, "@")?;
self.print_def_path(did.to_def_id(), args)?;
} else {
let span = self.tcx().def_span(did);
let preference = if with_forced_trimmed_paths() {
FileNameDisplayPreference::Short
} else {
FileNameDisplayPreference::Remapped
};
write!(
self,
"@{}",
// This may end up in stderr diagnostics but it may also be emitted
// into MIR. Hence we use the remapped path if available
self.tcx().sess.source_map().span_to_string(span, preference)
)?;
}
} else {
write!(self, "@")?;
self.print_def_path(did, args)?;
}
} else {
self.print_def_path(did, args)?;
write!(self, " closure_kind_ty=")?;
args.as_coroutine_closure().kind_ty().print(self)?;
write!(self, " signature_parts_ty=")?;
args.as_coroutine_closure().signature_parts_ty().print(self)?;
write!(self, " upvar_tys=")?;
args.as_coroutine_closure().tupled_upvars_ty().print(self)?;
write!(self, " coroutine_captures_by_ref_ty=")?;
args.as_coroutine_closure().coroutine_captures_by_ref_ty().print(self)?;
}
write!(self, "}}")?;
}
ty::Array(ty, sz) => {
write!(self, "[")?;
ty.print(self)?;
write!(self, "; ")?;
sz.print(self)?;
write!(self, "]")?;
}
ty::Slice(ty) => {
write!(self, "[")?;
ty.print(self)?;
write!(self, "]")?;
}
}
Ok(())
}
fn pretty_print_opaque_impl_type(
&mut self,
def_id: DefId,
args: ty::GenericArgsRef<'tcx>,
) -> Result<(), PrintError> {
let tcx = self.tcx();
// Grab the "TraitA + TraitB" from `impl TraitA + TraitB`,
// by looking up the projections associated with the def_id.
let bounds = tcx.explicit_item_bounds(def_id);
let mut traits = FxIndexMap::default();
let mut fn_traits = FxIndexMap::default();
let mut lifetimes = SmallVec::<[ty::Region<'tcx>; 1]>::new();
let mut has_sized_bound = false;
let mut has_negative_sized_bound = false;
let mut has_meta_sized_bound = false;
for (predicate, _) in bounds.iter_instantiated_copied(tcx, args) {
let bound_predicate = predicate.kind();
match bound_predicate.skip_binder() {
ty::ClauseKind::Trait(pred) => {
// With `feature(sized_hierarchy)`, don't print `?Sized` as an alias for
// `MetaSized`, and skip sizedness bounds to be added at the end.
match tcx.as_lang_item(pred.def_id()) {
Some(LangItem::Sized) => match pred.polarity {
ty::PredicatePolarity::Positive => {
has_sized_bound = true;
continue;
}
ty::PredicatePolarity::Negative => has_negative_sized_bound = true,
},
Some(LangItem::MetaSized) => {
has_meta_sized_bound = true;
continue;
}
Some(LangItem::PointeeSized) => {
bug!("`PointeeSized` is removed during lowering");
}
_ => (),
}
self.insert_trait_and_projection(
bound_predicate.rebind(pred),
None,
&mut traits,
&mut fn_traits,
);
}
ty::ClauseKind::Projection(pred) => {
let proj = bound_predicate.rebind(pred);
let trait_ref = proj.map_bound(|proj| TraitPredicate {
trait_ref: proj.projection_term.trait_ref(tcx),
polarity: ty::PredicatePolarity::Positive,
});
self.insert_trait_and_projection(
trait_ref,
Some((proj.item_def_id(), proj.term())),
&mut traits,
&mut fn_traits,
);
}
ty::ClauseKind::TypeOutlives(outlives) => {
lifetimes.push(outlives.1);
}
_ => {}
}
}
write!(self, "impl ")?;
let mut first = true;
// Insert parenthesis around (Fn(A, B) -> C) if the opaque ty has more than one other trait
let paren_needed = fn_traits.len() > 1 || traits.len() > 0 || !has_sized_bound;
for ((bound_args_and_self_ty, is_async), entry) in fn_traits {
write!(self, "{}", if first { "" } else { " + " })?;
write!(self, "{}", if paren_needed { "(" } else { "" })?;
let trait_def_id = if is_async {
tcx.async_fn_trait_kind_to_def_id(entry.kind).expect("expected AsyncFn lang items")
} else {
tcx.fn_trait_kind_to_def_id(entry.kind).expect("expected Fn lang items")
};
if let Some(return_ty) = entry.return_ty {
self.wrap_binder(
&bound_args_and_self_ty,
WrapBinderMode::ForAll,
|(args, _), p| {
write!(p, "{}", tcx.item_name(trait_def_id))?;
write!(p, "(")?;
for (idx, ty) in args.iter().enumerate() {
if idx > 0 {
write!(p, ", ")?;
}
ty.print(p)?;
}
write!(p, ")")?;
if let Some(ty) = return_ty.skip_binder().as_type() {
if !ty.is_unit() {
write!(p, " -> ")?;
return_ty.print(p)?;
}
}
write!(p, "{}", if paren_needed { ")" } else { "" })?;
first = false;
Ok(())
},
)?;
} else {
// Otherwise, render this like a regular trait.
traits.insert(
bound_args_and_self_ty.map_bound(|(args, self_ty)| ty::TraitPredicate {
polarity: ty::PredicatePolarity::Positive,
trait_ref: ty::TraitRef::new(
tcx,
trait_def_id,
[self_ty, Ty::new_tup(tcx, args)],
),
}),
FxIndexMap::default(),
);
}
}
// Print the rest of the trait types (that aren't Fn* family of traits)
for (trait_pred, assoc_items) in traits {
write!(self, "{}", if first { "" } else { " + " })?;
self.wrap_binder(&trait_pred, WrapBinderMode::ForAll, |trait_pred, p| {
if trait_pred.polarity == ty::PredicatePolarity::Negative {
write!(p, "!")?;
}
trait_pred.trait_ref.print_only_trait_name().print(p)?;
let generics = tcx.generics_of(trait_pred.def_id());
let own_args = generics.own_args_no_defaults(tcx, trait_pred.trait_ref.args);
if !own_args.is_empty() || !assoc_items.is_empty() {
let mut first = true;
for ty in own_args {
if first {
write!(p, "<")?;
first = false;
} else {
write!(p, ", ")?;
}
ty.print(p)?;
}
for (assoc_item_def_id, term) in assoc_items {
if first {
write!(p, "<")?;
first = false;
} else {
write!(p, ", ")?;
}
write!(p, "{} = ", tcx.associated_item(assoc_item_def_id).name())?;
match term.skip_binder().kind() {
TermKind::Ty(ty) => ty.print(p)?,
TermKind::Const(c) => c.print(p)?,
};
}
if !first {
write!(p, ">")?;
}
}
first = false;
Ok(())
})?;
}
let using_sized_hierarchy = self.tcx().features().sized_hierarchy();
let add_sized = has_sized_bound && (first || has_negative_sized_bound);
let add_maybe_sized =
has_meta_sized_bound && !has_negative_sized_bound && !using_sized_hierarchy;
// Set `has_pointee_sized_bound` if there were no `Sized` or `MetaSized` bounds.
let has_pointee_sized_bound =
!has_sized_bound && !has_meta_sized_bound && !has_negative_sized_bound;
if add_sized || add_maybe_sized {
if !first {
write!(self, " + ")?;
}
if add_maybe_sized {
write!(self, "?")?;
}
write!(self, "Sized")?;
} else if has_meta_sized_bound && using_sized_hierarchy {
if !first {
write!(self, " + ")?;
}
write!(self, "MetaSized")?;
} else if has_pointee_sized_bound && using_sized_hierarchy {
if !first {
write!(self, " + ")?;
}
write!(self, "PointeeSized")?;
}
if !with_forced_trimmed_paths() {
for re in lifetimes {
write!(self, " + ")?;
self.print_region(re)?;
}
}
Ok(())
}
/// Insert the trait ref and optionally a projection type associated with it into either the
/// traits map or fn_traits map, depending on if the trait is in the Fn* family of traits.
fn insert_trait_and_projection(
&mut self,
trait_pred: ty::PolyTraitPredicate<'tcx>,
proj_ty: Option<(DefId, ty::Binder<'tcx, Term<'tcx>>)>,
traits: &mut FxIndexMap<
ty::PolyTraitPredicate<'tcx>,
FxIndexMap<DefId, ty::Binder<'tcx, Term<'tcx>>>,
>,
fn_traits: &mut FxIndexMap<
(ty::Binder<'tcx, (&'tcx ty::List<Ty<'tcx>>, Ty<'tcx>)>, bool),
OpaqueFnEntry<'tcx>,
>,
) {
let tcx = self.tcx();
let trait_def_id = trait_pred.def_id();
let fn_trait_and_async = if let Some(kind) = tcx.fn_trait_kind_from_def_id(trait_def_id) {
Some((kind, false))
} else if let Some(kind) = tcx.async_fn_trait_kind_from_def_id(trait_def_id) {
Some((kind, true))
} else {
None
};
if trait_pred.polarity() == ty::PredicatePolarity::Positive
&& let Some((kind, is_async)) = fn_trait_and_async
&& let ty::Tuple(types) = *trait_pred.skip_binder().trait_ref.args.type_at(1).kind()
{
let entry = fn_traits
.entry((trait_pred.rebind((types, trait_pred.skip_binder().self_ty())), is_async))
.or_insert_with(|| OpaqueFnEntry { kind, return_ty: None });
if kind.extends(entry.kind) {
entry.kind = kind;
}
if let Some((proj_def_id, proj_ty)) = proj_ty
&& tcx.item_name(proj_def_id) == sym::Output
{
entry.return_ty = Some(proj_ty);
}
return;
}
// Otherwise, just group our traits and projection types.
traits.entry(trait_pred).or_default().extend(proj_ty);
}
fn pretty_print_inherent_projection(
&mut self,
alias_ty: ty::AliasTerm<'tcx>,
) -> Result<(), PrintError> {
let def_key = self.tcx().def_key(alias_ty.def_id);
self.print_path_with_generic_args(
|p| {
p.print_path_with_simple(
|p| p.print_path_with_qualified(alias_ty.self_ty(), None),
&def_key.disambiguated_data,
)
},
&alias_ty.args[1..],
)
}
fn pretty_print_rpitit(
&mut self,
def_id: DefId,
args: ty::GenericArgsRef<'tcx>,
) -> Result<(), PrintError> {
let fn_args = if self.tcx().features().return_type_notation()
&& let Some(ty::ImplTraitInTraitData::Trait { fn_def_id, .. }) =
self.tcx().opt_rpitit_info(def_id)
&& let ty::Alias(_, alias_ty) =
self.tcx().fn_sig(fn_def_id).skip_binder().output().skip_binder().kind()
&& alias_ty.def_id == def_id
&& let generics = self.tcx().generics_of(fn_def_id)
// FIXME(return_type_notation): We only support lifetime params for now.
&& generics.own_params.iter().all(|param| matches!(param.kind, ty::GenericParamDefKind::Lifetime))
{
let num_args = generics.count();
Some((fn_def_id, &args[..num_args]))
} else {
None
};
match (fn_args, RTN_MODE.with(|c| c.get())) {
(Some((fn_def_id, fn_args)), RtnMode::ForDiagnostic) => {
self.pretty_print_opaque_impl_type(def_id, args)?;
write!(self, " {{ ")?;
self.print_def_path(fn_def_id, fn_args)?;
write!(self, "(..) }}")?;
}
(Some((fn_def_id, fn_args)), RtnMode::ForSuggestion) => {
self.print_def_path(fn_def_id, fn_args)?;
write!(self, "(..)")?;
}
_ => {
self.pretty_print_opaque_impl_type(def_id, args)?;
}
}
Ok(())
}
fn ty_infer_name(&self, _: ty::TyVid) -> Option<Symbol> {
None
}
fn const_infer_name(&self, _: ty::ConstVid) -> Option<Symbol> {
None
}
fn pretty_print_dyn_existential(
&mut self,
predicates: &'tcx ty::List<ty::PolyExistentialPredicate<'tcx>>,
) -> Result<(), PrintError> {
// Generate the main trait ref, including associated types.
let mut first = true;
if let Some(bound_principal) = predicates.principal() {
self.wrap_binder(&bound_principal, WrapBinderMode::ForAll, |principal, p| {
p.print_def_path(principal.def_id, &[])?;
let mut resugared = false;
// Special-case `Fn(...) -> ...` and re-sugar it.
let fn_trait_kind = p.tcx().fn_trait_kind_from_def_id(principal.def_id);
if !p.should_print_verbose() && fn_trait_kind.is_some() {
if let ty::Tuple(tys) = principal.args.type_at(0).kind() {
let mut projections = predicates.projection_bounds();
if let (Some(proj), None) = (projections.next(), projections.next()) {
p.pretty_print_fn_sig(
tys,
false,
proj.skip_binder().term.as_type().expect("Return type was a const"),
)?;
resugared = true;
}
}
}
// HACK(eddyb) this duplicates `FmtPrinter`'s `print_path_with_generic_args`,
// in order to place the projections inside the `<...>`.
if !resugared {
let principal_with_self =
principal.with_self_ty(p.tcx(), p.tcx().types.trait_object_dummy_self);
let args = p
.tcx()
.generics_of(principal_with_self.def_id)
.own_args_no_defaults(p.tcx(), principal_with_self.args);
let bound_principal_with_self = bound_principal
.with_self_ty(p.tcx(), p.tcx().types.trait_object_dummy_self);
let clause: ty::Clause<'tcx> = bound_principal_with_self.upcast(p.tcx());
let super_projections: Vec<_> = elaborate::elaborate(p.tcx(), [clause])
.filter_only_self()
.filter_map(|clause| clause.as_projection_clause())
.collect();
let mut projections: Vec<_> = predicates
.projection_bounds()
.filter(|&proj| {
// Filter out projections that are implied by the super predicates.
let proj_is_implied = super_projections.iter().any(|&super_proj| {
let super_proj = super_proj.map_bound(|super_proj| {
ty::ExistentialProjection::erase_self_ty(p.tcx(), super_proj)
});
// This function is sometimes called on types with erased and
// anonymized regions, but the super projections can still
// contain named regions. So we erase and anonymize everything
// here to compare the types modulo regions below.
let proj = p.tcx().erase_and_anonymize_regions(proj);
let super_proj = p.tcx().erase_and_anonymize_regions(super_proj);
proj == super_proj
});
!proj_is_implied
})
.map(|proj| {
// Skip the binder, because we don't want to print the binder in
// front of the associated item.
proj.skip_binder()
})
.collect();
projections
.sort_by_cached_key(|proj| p.tcx().item_name(proj.def_id).to_string());
if !args.is_empty() || !projections.is_empty() {
p.generic_delimiters(|p| {
p.comma_sep(args.iter().copied())?;
if !args.is_empty() && !projections.is_empty() {
write!(p, ", ")?;
}
p.comma_sep(projections.iter().copied())
})?;
}
}
Ok(())
})?;
first = false;
}
// Builtin bounds.
// FIXME(eddyb) avoid printing twice (needed to ensure
// that the auto traits are sorted *and* printed via p).
let mut auto_traits: Vec<_> = predicates.auto_traits().collect();
// The auto traits come ordered by `DefPathHash`. While
// `DefPathHash` is *stable* in the sense that it depends on
// neither the host nor the phase of the moon, it depends
// "pseudorandomly" on the compiler version and the target.
//
// To avoid causing instabilities in compiletest
// output, sort the auto-traits alphabetically.
auto_traits.sort_by_cached_key(|did| with_no_trimmed_paths!(self.tcx().def_path_str(*did)));
for def_id in auto_traits {
if !first {
write!(self, " + ")?;
}
first = false;
self.print_def_path(def_id, &[])?;
}
Ok(())
}
fn pretty_print_fn_sig(
&mut self,
inputs: &[Ty<'tcx>],
c_variadic: bool,
output: Ty<'tcx>,
) -> Result<(), PrintError> {
write!(self, "(")?;
self.comma_sep(inputs.iter().copied())?;
if c_variadic {
if !inputs.is_empty() {
write!(self, ", ")?;
}
write!(self, "...")?;
}
write!(self, ")")?;
if !output.is_unit() {
write!(self, " -> ")?;
output.print(self)?;
}
Ok(())
}
fn pretty_print_const(
&mut self,
ct: ty::Const<'tcx>,
print_ty: bool,
) -> Result<(), PrintError> {
if self.should_print_verbose() {
write!(self, "{ct:?}")?;
return Ok(());
}
match ct.kind() {
ty::ConstKind::Unevaluated(ty::UnevaluatedConst { def, args }) => {
match self.tcx().def_kind(def) {
DefKind::Const | DefKind::AssocConst => {
self.pretty_print_value_path(def, args)?;
}
DefKind::AnonConst => {
if def.is_local()
&& let span = self.tcx().def_span(def)
&& let Ok(snip) = self.tcx().sess.source_map().span_to_snippet(span)
{
write!(self, "{snip}")?;
} else {
// Do not call `pretty_print_value_path` as if a parent of this anon
// const is an impl it will attempt to print out the impl trait ref
// i.e. `<T as Trait>::{constant#0}`. This would cause printing to
// enter an infinite recursion if the anon const is in the self type
// i.e. `impl<T: Default> Default for [T; 32 - 1 - 1 - 1] {` where we
// would try to print `<[T; /* print constant#0 again */] as //
// Default>::{constant#0}`.
write!(
self,
"{}::{}",
self.tcx().crate_name(def.krate),
self.tcx().def_path(def).to_string_no_crate_verbose()
)?;
}
}
defkind => bug!("`{:?}` has unexpected defkind {:?}", ct, defkind),
}
}
ty::ConstKind::Infer(infer_ct) => match infer_ct {
ty::InferConst::Var(ct_vid) if let Some(name) = self.const_infer_name(ct_vid) => {
write!(self, "{name}")?;
}
_ => write!(self, "_")?,
},
ty::ConstKind::Param(ParamConst { name, .. }) => write!(self, "{name}")?,
ty::ConstKind::Value(cv) => {
return self.pretty_print_const_valtree(cv, print_ty);
}
ty::ConstKind::Bound(debruijn, bound_var) => {
rustc_type_ir::debug_bound_var(self, debruijn, bound_var)?
}
ty::ConstKind::Placeholder(placeholder) => write!(self, "{placeholder:?}")?,
// FIXME(generic_const_exprs):
// write out some legible representation of an abstract const?
ty::ConstKind::Expr(expr) => self.pretty_print_const_expr(expr, print_ty)?,
ty::ConstKind::Error(_) => write!(self, "{{const error}}")?,
};
Ok(())
}
fn pretty_print_const_expr(
&mut self,
expr: Expr<'tcx>,
print_ty: bool,
) -> Result<(), PrintError> {
match expr.kind {
ty::ExprKind::Binop(op) => {
let (_, _, c1, c2) = expr.binop_args();
let precedence = |binop: crate::mir::BinOp| binop.to_hir_binop().precedence();
let op_precedence = precedence(op);
let formatted_op = op.to_hir_binop().as_str();
let (lhs_parenthesized, rhs_parenthesized) = match (c1.kind(), c2.kind()) {
(
ty::ConstKind::Expr(ty::Expr { kind: ty::ExprKind::Binop(lhs_op), .. }),
ty::ConstKind::Expr(ty::Expr { kind: ty::ExprKind::Binop(rhs_op), .. }),
) => (precedence(lhs_op) < op_precedence, precedence(rhs_op) < op_precedence),
(
ty::ConstKind::Expr(ty::Expr { kind: ty::ExprKind::Binop(lhs_op), .. }),
ty::ConstKind::Expr(_),
) => (precedence(lhs_op) < op_precedence, true),
(
ty::ConstKind::Expr(_),
ty::ConstKind::Expr(ty::Expr { kind: ty::ExprKind::Binop(rhs_op), .. }),
) => (true, precedence(rhs_op) < op_precedence),
(ty::ConstKind::Expr(_), ty::ConstKind::Expr(_)) => (true, true),
(
ty::ConstKind::Expr(ty::Expr { kind: ty::ExprKind::Binop(lhs_op), .. }),
_,
) => (precedence(lhs_op) < op_precedence, false),
(
_,
ty::ConstKind::Expr(ty::Expr { kind: ty::ExprKind::Binop(rhs_op), .. }),
) => (false, precedence(rhs_op) < op_precedence),
(ty::ConstKind::Expr(_), _) => (true, false),
(_, ty::ConstKind::Expr(_)) => (false, true),
_ => (false, false),
};
self.maybe_parenthesized(
|this| this.pretty_print_const(c1, print_ty),
lhs_parenthesized,
)?;
write!(self, " {formatted_op} ")?;
self.maybe_parenthesized(
|this| this.pretty_print_const(c2, print_ty),
rhs_parenthesized,
)?;
}
ty::ExprKind::UnOp(op) => {
let (_, ct) = expr.unop_args();
use crate::mir::UnOp;
let formatted_op = match op {
UnOp::Not => "!",
UnOp::Neg => "-",
UnOp::PtrMetadata => "PtrMetadata",
};
let parenthesized = match ct.kind() {
_ if op == UnOp::PtrMetadata => true,
ty::ConstKind::Expr(ty::Expr { kind: ty::ExprKind::UnOp(c_op), .. }) => {
c_op != op
}
ty::ConstKind::Expr(_) => true,
_ => false,
};
write!(self, "{formatted_op}")?;
self.maybe_parenthesized(
|this| this.pretty_print_const(ct, print_ty),
parenthesized,
)?
}
ty::ExprKind::FunctionCall => {
let (_, fn_def, fn_args) = expr.call_args();
write!(self, "(")?;
self.pretty_print_const(fn_def, print_ty)?;
write!(self, ")(")?;
self.comma_sep(fn_args)?;
write!(self, ")")?;
}
ty::ExprKind::Cast(kind) => {
let (_, value, to_ty) = expr.cast_args();
use ty::abstract_const::CastKind;
if kind == CastKind::As || (kind == CastKind::Use && self.should_print_verbose()) {
let parenthesized = match value.kind() {
ty::ConstKind::Expr(ty::Expr {
kind: ty::ExprKind::Cast { .. }, ..
}) => false,
ty::ConstKind::Expr(_) => true,
_ => false,
};
self.maybe_parenthesized(
|this| {
this.typed_value(
|this| this.pretty_print_const(value, print_ty),
|this| this.pretty_print_type(to_ty),
" as ",
)
},
parenthesized,
)?;
} else {
self.pretty_print_const(value, print_ty)?
}
}
}
Ok(())
}
fn pretty_print_const_scalar(
&mut self,
scalar: Scalar,
ty: Ty<'tcx>,
) -> Result<(), PrintError> {
match scalar {
Scalar::Ptr(ptr, _size) => self.pretty_print_const_scalar_ptr(ptr, ty),
Scalar::Int(int) => {
self.pretty_print_const_scalar_int(int, ty, /* print_ty */ true)
}
}
}
fn pretty_print_const_scalar_ptr(
&mut self,
ptr: Pointer,
ty: Ty<'tcx>,
) -> Result<(), PrintError> {
let (prov, offset) = ptr.prov_and_relative_offset();
match ty.kind() {
// Byte strings (&[u8; N])
ty::Ref(_, inner, _) => {
if let ty::Array(elem, ct_len) = inner.kind()
&& let ty::Uint(ty::UintTy::U8) = elem.kind()
&& let Some(len) = ct_len.try_to_target_usize(self.tcx())
{
match self.tcx().try_get_global_alloc(prov.alloc_id()) {
Some(GlobalAlloc::Memory(alloc)) => {
let range = AllocRange { start: offset, size: Size::from_bytes(len) };
if let Ok(byte_str) =
alloc.inner().get_bytes_strip_provenance(&self.tcx(), range)
{
self.pretty_print_byte_str(byte_str)?;
} else {
write!(self, "<too short allocation>")?;
}
}
// FIXME: for statics, vtables, and functions, we could in principle print more detail.
Some(GlobalAlloc::Static(def_id)) => {
write!(self, "<static({def_id:?})>")?;
}
Some(GlobalAlloc::Function { .. }) => write!(self, "<function>")?,
Some(GlobalAlloc::VTable(..)) => write!(self, "<vtable>")?,
Some(GlobalAlloc::TypeId { .. }) => write!(self, "<typeid>")?,
None => write!(self, "<dangling pointer>")?,
}
return Ok(());
}
}
ty::FnPtr(..) => {
// FIXME: We should probably have a helper method to share code with the "Byte strings"
// printing above (which also has to handle pointers to all sorts of things).
if let Some(GlobalAlloc::Function { instance, .. }) =
self.tcx().try_get_global_alloc(prov.alloc_id())
{
self.typed_value(
|this| this.pretty_print_value_path(instance.def_id(), instance.args),
|this| this.print_type(ty),
" as ",
)?;
return Ok(());
}
}
_ => {}
}
// Any pointer values not covered by a branch above
self.pretty_print_const_pointer(ptr, ty)?;
Ok(())
}
fn pretty_print_const_scalar_int(
&mut self,
int: ScalarInt,
ty: Ty<'tcx>,
print_ty: bool,
) -> Result<(), PrintError> {
match ty.kind() {
// Bool
ty::Bool if int == ScalarInt::FALSE => write!(self, "false")?,
ty::Bool if int == ScalarInt::TRUE => write!(self, "true")?,
// Float
ty::Float(fty) => match fty {
ty::FloatTy::F16 => {
let val = Half::try_from(int).unwrap();
write!(self, "{}{}f16", val, if val.is_finite() { "" } else { "_" })?;
}
ty::FloatTy::F32 => {
let val = Single::try_from(int).unwrap();
write!(self, "{}{}f32", val, if val.is_finite() { "" } else { "_" })?;
}
ty::FloatTy::F64 => {
let val = Double::try_from(int).unwrap();
write!(self, "{}{}f64", val, if val.is_finite() { "" } else { "_" })?;
}
ty::FloatTy::F128 => {
let val = Quad::try_from(int).unwrap();
write!(self, "{}{}f128", val, if val.is_finite() { "" } else { "_" })?;
}
},
// Int
ty::Uint(_) | ty::Int(_) => {
let int =
ConstInt::new(int, matches!(ty.kind(), ty::Int(_)), ty.is_ptr_sized_integral());
if print_ty { write!(self, "{int:#?}")? } else { write!(self, "{int:?}")? }
}
// Char
ty::Char if char::try_from(int).is_ok() => {
write!(self, "{:?}", char::try_from(int).unwrap())?;
}
// Pointer types
ty::Ref(..) | ty::RawPtr(_, _) | ty::FnPtr(..) => {
let data = int.to_bits(self.tcx().data_layout.pointer_size());
self.typed_value(
|this| {
write!(this, "0x{data:x}")?;
Ok(())
},
|this| this.print_type(ty),
" as ",
)?;
}
ty::Pat(base_ty, pat) if self.tcx().validate_scalar_in_layout(int, ty) => {
self.pretty_print_const_scalar_int(int, *base_ty, print_ty)?;
write!(self, " is {pat:?}")?;
}
// Nontrivial types with scalar bit representation
_ => {
let print = |this: &mut Self| {
if int.size() == Size::ZERO {
write!(this, "transmute(())")?;
} else {
write!(this, "transmute(0x{int:x})")?;
}
Ok(())
};
if print_ty {
self.typed_value(print, |this| this.print_type(ty), ": ")?
} else {
print(self)?
};
}
}
Ok(())
}
/// This is overridden for MIR printing because we only want to hide alloc ids from users, not
/// from MIR where it is actually useful.
fn pretty_print_const_pointer<Prov: Provenance>(
&mut self,
_: Pointer<Prov>,
ty: Ty<'tcx>,
) -> Result<(), PrintError> {
self.typed_value(
|this| {
this.write_str("&_")?;
Ok(())
},
|this| this.print_type(ty),
": ",
)
}
fn pretty_print_byte_str(&mut self, byte_str: &'tcx [u8]) -> Result<(), PrintError> {
write!(self, "b\"{}\"", byte_str.escape_ascii())?;
Ok(())
}
fn pretty_print_const_valtree(
&mut self,
cv: ty::Value<'tcx>,
print_ty: bool,
) -> Result<(), PrintError> {
if with_reduced_queries() || self.should_print_verbose() {
write!(self, "ValTree({:?}: ", cv.valtree)?;
cv.ty.print(self)?;
write!(self, ")")?;
return Ok(());
}
let u8_type = self.tcx().types.u8;
match (*cv.valtree, *cv.ty.kind()) {
(ty::ValTreeKind::Branch(_), ty::Ref(_, inner_ty, _)) => match inner_ty.kind() {
ty::Slice(t) if *t == u8_type => {
let bytes = cv.try_to_raw_bytes(self.tcx()).unwrap_or_else(|| {
bug!(
"expected to convert valtree {:?} to raw bytes for type {:?}",
cv.valtree,
t
)
});
return self.pretty_print_byte_str(bytes);
}
ty::Str => {
let bytes = cv.try_to_raw_bytes(self.tcx()).unwrap_or_else(|| {
bug!("expected to convert valtree to raw bytes for type {:?}", cv.ty)
});
write!(self, "{:?}", String::from_utf8_lossy(bytes))?;
return Ok(());
}
_ => {
let cv = ty::Value { valtree: cv.valtree, ty: inner_ty };
write!(self, "&")?;
self.pretty_print_const_valtree(cv, print_ty)?;
return Ok(());
}
},
(ty::ValTreeKind::Branch(_), ty::Array(t, _)) if t == u8_type => {
let bytes = cv.try_to_raw_bytes(self.tcx()).unwrap_or_else(|| {
bug!("expected to convert valtree to raw bytes for type {:?}", t)
});
write!(self, "*")?;
self.pretty_print_byte_str(bytes)?;
return Ok(());
}
// Aggregates, printed as array/tuple/struct/variant construction syntax.
(ty::ValTreeKind::Branch(_), ty::Array(..) | ty::Tuple(..) | ty::Adt(..)) => {
let contents = self.tcx().destructure_const(ty::Const::new_value(
self.tcx(),
cv.valtree,
cv.ty,
));
let fields = contents.fields.iter().copied();
match *cv.ty.kind() {
ty::Array(..) => {
write!(self, "[")?;
self.comma_sep(fields)?;
write!(self, "]")?;
}
ty::Tuple(..) => {
write!(self, "(")?;
self.comma_sep(fields)?;
if contents.fields.len() == 1 {
write!(self, ",")?;
}
write!(self, ")")?;
}
ty::Adt(def, _) if def.variants().is_empty() => {
self.typed_value(
|this| {
write!(this, "unreachable()")?;
Ok(())
},
|this| this.print_type(cv.ty),
": ",
)?;
}
ty::Adt(def, args) => {
let variant_idx =
contents.variant.expect("destructed const of adt without variant idx");
let variant_def = &def.variant(variant_idx);
self.pretty_print_value_path(variant_def.def_id, args)?;
match variant_def.ctor_kind() {
Some(CtorKind::Const) => {}
Some(CtorKind::Fn) => {
write!(self, "(")?;
self.comma_sep(fields)?;
write!(self, ")")?;
}
None => {
write!(self, " {{ ")?;
let mut first = true;
for (field_def, field) in iter::zip(&variant_def.fields, fields) {
if !first {
write!(self, ", ")?;
}
write!(self, "{}: ", field_def.name)?;
field.print(self)?;
first = false;
}
write!(self, " }}")?;
}
}
}
_ => unreachable!(),
}
return Ok(());
}
(ty::ValTreeKind::Leaf(leaf), ty::Ref(_, inner_ty, _)) => {
write!(self, "&")?;
return self.pretty_print_const_scalar_int(*leaf, inner_ty, print_ty);
}
(ty::ValTreeKind::Leaf(leaf), _) => {
return self.pretty_print_const_scalar_int(*leaf, cv.ty, print_ty);
}
(_, ty::FnDef(def_id, args)) => {
// Never allowed today, but we still encounter them in invalid const args.
self.pretty_print_value_path(def_id, args)?;
return Ok(());
}
// FIXME(oli-obk): also pretty print arrays and other aggregate constants by reading
// their fields instead of just dumping the memory.
_ => {}
}
// fallback
if cv.valtree.is_zst() {
write!(self, "<ZST>")?;
} else {
write!(self, "{:?}", cv.valtree)?;
}
if print_ty {
write!(self, ": ")?;
cv.ty.print(self)?;
}
Ok(())
}
fn pretty_print_closure_as_impl(
&mut self,
closure: ty::ClosureArgs<TyCtxt<'tcx>>,
) -> Result<(), PrintError> {
let sig = closure.sig();
let kind = closure.kind_ty().to_opt_closure_kind().unwrap_or(ty::ClosureKind::Fn);
write!(self, "impl ")?;
self.wrap_binder(&sig, WrapBinderMode::ForAll, |sig, p| {
write!(p, "{kind}(")?;
for (i, arg) in sig.inputs()[0].tuple_fields().iter().enumerate() {
if i > 0 {
write!(p, ", ")?;
}
arg.print(p)?;
}
write!(p, ")")?;
if !sig.output().is_unit() {
write!(p, " -> ")?;
sig.output().print(p)?;
}
Ok(())
})
}
fn pretty_print_bound_constness(
&mut self,
constness: ty::BoundConstness,
) -> Result<(), PrintError> {
match constness {
ty::BoundConstness::Const => write!(self, "const ")?,
ty::BoundConstness::Maybe => write!(self, "[const] ")?,
}
Ok(())
}
fn should_print_verbose(&self) -> bool {
self.tcx().sess.verbose_internals()
}
}
pub(crate) fn pretty_print_const<'tcx>(
c: ty::Const<'tcx>,
fmt: &mut fmt::Formatter<'_>,
print_types: bool,
) -> fmt::Result {
ty::tls::with(|tcx| {
let literal = tcx.lift(c).unwrap();
let mut p = FmtPrinter::new(tcx, Namespace::ValueNS);
p.print_alloc_ids = true;
p.pretty_print_const(literal, print_types)?;
fmt.write_str(&p.into_buffer())?;
Ok(())
})
}
// HACK(eddyb) boxed to avoid moving around a large struct by-value.
pub struct FmtPrinter<'a, 'tcx>(Box<FmtPrinterData<'a, 'tcx>>);
pub struct FmtPrinterData<'a, 'tcx> {
tcx: TyCtxt<'tcx>,
fmt: String,
empty_path: bool,
in_value: bool,
pub print_alloc_ids: bool,
// set of all named (non-anonymous) region names
used_region_names: FxHashSet<Symbol>,
region_index: usize,
binder_depth: usize,
printed_type_count: usize,
type_length_limit: Limit,
pub region_highlight_mode: RegionHighlightMode<'tcx>,
pub ty_infer_name_resolver: Option<Box<dyn Fn(ty::TyVid) -> Option<Symbol> + 'a>>,
pub const_infer_name_resolver: Option<Box<dyn Fn(ty::ConstVid) -> Option<Symbol> + 'a>>,
}
impl<'a, 'tcx> Deref for FmtPrinter<'a, 'tcx> {
type Target = FmtPrinterData<'a, 'tcx>;
fn deref(&self) -> &Self::Target {
&self.0
}
}
impl DerefMut for FmtPrinter<'_, '_> {
fn deref_mut(&mut self) -> &mut Self::Target {
&mut self.0
}
}
impl<'a, 'tcx> FmtPrinter<'a, 'tcx> {
pub fn new(tcx: TyCtxt<'tcx>, ns: Namespace) -> Self {
let limit =
if with_reduced_queries() { Limit::new(1048576) } else { tcx.type_length_limit() };
Self::new_with_limit(tcx, ns, limit)
}
pub fn print_string(
tcx: TyCtxt<'tcx>,
ns: Namespace,
f: impl FnOnce(&mut Self) -> Result<(), PrintError>,
) -> Result<String, PrintError> {
let mut c = FmtPrinter::new(tcx, ns);
f(&mut c)?;
Ok(c.into_buffer())
}
pub fn new_with_limit(tcx: TyCtxt<'tcx>, ns: Namespace, type_length_limit: Limit) -> Self {
FmtPrinter(Box::new(FmtPrinterData {
tcx,
// Estimated reasonable capacity to allocate upfront based on a few
// benchmarks.
fmt: String::with_capacity(64),
empty_path: false,
in_value: ns == Namespace::ValueNS,
print_alloc_ids: false,
used_region_names: Default::default(),
region_index: 0,
binder_depth: 0,
printed_type_count: 0,
type_length_limit,
region_highlight_mode: RegionHighlightMode::default(),
ty_infer_name_resolver: None,
const_infer_name_resolver: None,
}))
}
pub fn into_buffer(self) -> String {
self.0.fmt
}
}
fn guess_def_namespace(tcx: TyCtxt<'_>, def_id: DefId) -> Namespace {
match tcx.def_key(def_id).disambiguated_data.data {
DefPathData::TypeNs(..) | DefPathData::CrateRoot | DefPathData::OpaqueTy => {
Namespace::TypeNS
}
DefPathData::ValueNs(..)
| DefPathData::AnonConst
| DefPathData::Closure
| DefPathData::Ctor => Namespace::ValueNS,
DefPathData::MacroNs(..) => Namespace::MacroNS,
_ => Namespace::TypeNS,
}
}
impl<'t> TyCtxt<'t> {
/// Returns a string identifying this `DefId`. This string is
/// suitable for user output.
pub fn def_path_str(self, def_id: impl IntoQueryParam<DefId>) -> String {
self.def_path_str_with_args(def_id, &[])
}
/// For this one we determine the appropriate namespace for the `def_id`.
pub fn def_path_str_with_args(
self,
def_id: impl IntoQueryParam<DefId>,
args: &'t [GenericArg<'t>],
) -> String {
let def_id = def_id.into_query_param();
let ns = guess_def_namespace(self, def_id);
debug!("def_path_str: def_id={:?}, ns={:?}", def_id, ns);
FmtPrinter::print_string(self, ns, |p| p.print_def_path(def_id, args)).unwrap()
}
/// For this one we always use value namespace.
pub fn value_path_str_with_args(
self,
def_id: impl IntoQueryParam<DefId>,
args: &'t [GenericArg<'t>],
) -> String {
let def_id = def_id.into_query_param();
let ns = Namespace::ValueNS;
debug!("value_path_str: def_id={:?}, ns={:?}", def_id, ns);
FmtPrinter::print_string(self, ns, |p| p.print_def_path(def_id, args)).unwrap()
}
}
impl fmt::Write for FmtPrinter<'_, '_> {
fn write_str(&mut self, s: &str) -> fmt::Result {
self.fmt.push_str(s);
Ok(())
}
}
impl<'tcx> Printer<'tcx> for FmtPrinter<'_, 'tcx> {
fn tcx<'a>(&'a self) -> TyCtxt<'tcx> {
self.tcx
}
fn print_def_path(
&mut self,
def_id: DefId,
args: &'tcx [GenericArg<'tcx>],
) -> Result<(), PrintError> {
if args.is_empty() {
match self.try_print_trimmed_def_path(def_id)? {
true => return Ok(()),
false => {}
}
match self.try_print_visible_def_path(def_id)? {
true => return Ok(()),
false => {}
}
}
let key = self.tcx.def_key(def_id);
if let DefPathData::Impl = key.disambiguated_data.data {
// Always use types for non-local impls, where types are always
// available, and filename/line-number is mostly uninteresting.
let use_types = !def_id.is_local() || {
// Otherwise, use filename/line-number if forced.
let force_no_types = with_forced_impl_filename_line();
!force_no_types
};
if !use_types {
// If no type info is available, fall back to
// pretty printing some span information. This should
// only occur very early in the compiler pipeline.
let parent_def_id = DefId { index: key.parent.unwrap(), ..def_id };
let span = self.tcx.def_span(def_id);
self.print_def_path(parent_def_id, &[])?;
// HACK(eddyb) copy of `print_path_with_simple` to avoid
// constructing a `DisambiguatedDefPathData`.
if !self.empty_path {
write!(self, "::")?;
}
write!(
self,
"<impl at {}>",
// This may end up in stderr diagnostics but it may also be emitted
// into MIR. Hence we use the remapped path if available
self.tcx.sess.source_map().span_to_embeddable_string(span)
)?;
self.empty_path = false;
return Ok(());
}
}
self.default_print_def_path(def_id, args)
}
fn print_region(&mut self, region: ty::Region<'tcx>) -> Result<(), PrintError> {
self.pretty_print_region(region)
}
fn print_type(&mut self, ty: Ty<'tcx>) -> Result<(), PrintError> {
match ty.kind() {
ty::Tuple(tys) if tys.len() == 0 && self.should_truncate() => {
// Don't truncate `()`.
self.printed_type_count += 1;
self.pretty_print_type(ty)
}
ty::Adt(..)
| ty::Foreign(_)
| ty::Pat(..)
| ty::RawPtr(..)
| ty::Ref(..)
| ty::FnDef(..)
| ty::FnPtr(..)
| ty::UnsafeBinder(..)
| ty::Dynamic(..)
| ty::Closure(..)
| ty::CoroutineClosure(..)
| ty::Coroutine(..)
| ty::CoroutineWitness(..)
| ty::Tuple(_)
| ty::Alias(..)
| ty::Param(_)
| ty::Bound(..)
| ty::Placeholder(_)
| ty::Error(_)
if self.should_truncate() =>
{
// We only truncate types that we know are likely to be much longer than 3 chars.
// There's no point in replacing `i32` or `!`.
write!(self, "...")?;
Ok(())
}
_ => {
self.printed_type_count += 1;
self.pretty_print_type(ty)
}
}
}
fn print_dyn_existential(
&mut self,
predicates: &'tcx ty::List<ty::PolyExistentialPredicate<'tcx>>,
) -> Result<(), PrintError> {
self.pretty_print_dyn_existential(predicates)
}
fn print_const(&mut self, ct: ty::Const<'tcx>) -> Result<(), PrintError> {
self.pretty_print_const(ct, false)
}
fn print_crate_name(&mut self, cnum: CrateNum) -> Result<(), PrintError> {
self.empty_path = true;
if cnum == LOCAL_CRATE {
if self.tcx.sess.at_least_rust_2018() {
// We add the `crate::` keyword on Rust 2018, only when desired.
if with_crate_prefix() {
write!(self, "{}", kw::Crate)?;
self.empty_path = false;
}
}
} else {
write!(self, "{}", self.tcx.crate_name(cnum))?;
self.empty_path = false;
}
Ok(())
}
fn print_path_with_qualified(
&mut self,
self_ty: Ty<'tcx>,
trait_ref: Option<ty::TraitRef<'tcx>>,
) -> Result<(), PrintError> {
self.pretty_print_path_with_qualified(self_ty, trait_ref)?;
self.empty_path = false;
Ok(())
}
fn print_path_with_impl(
&mut self,
print_prefix: impl FnOnce(&mut Self) -> Result<(), PrintError>,
self_ty: Ty<'tcx>,
trait_ref: Option<ty::TraitRef<'tcx>>,
) -> Result<(), PrintError> {
self.pretty_print_path_with_impl(
|p| {
print_prefix(p)?;
if !p.empty_path {
write!(p, "::")?;
}
Ok(())
},
self_ty,
trait_ref,
)?;
self.empty_path = false;
Ok(())
}
fn print_path_with_simple(
&mut self,
print_prefix: impl FnOnce(&mut Self) -> Result<(), PrintError>,
disambiguated_data: &DisambiguatedDefPathData,
) -> Result<(), PrintError> {
print_prefix(self)?;
// Skip `::{{extern}}` blocks and `::{{constructor}}` on tuple/unit structs.
if let DefPathData::ForeignMod | DefPathData::Ctor = disambiguated_data.data {
return Ok(());
}
let name = disambiguated_data.data.name();
if !self.empty_path {
write!(self, "::")?;
}
if let DefPathDataName::Named(name) = name {
if Ident::with_dummy_span(name).is_raw_guess() {
write!(self, "r#")?;
}
}
let verbose = self.should_print_verbose();
write!(self, "{}", disambiguated_data.as_sym(verbose))?;
self.empty_path = false;
Ok(())
}
fn print_path_with_generic_args(
&mut self,
print_prefix: impl FnOnce(&mut Self) -> Result<(), PrintError>,
args: &[GenericArg<'tcx>],
) -> Result<(), PrintError> {
print_prefix(self)?;
if !args.is_empty() {
if self.in_value {
write!(self, "::")?;
}
self.generic_delimiters(|p| p.comma_sep(args.iter().copied()))
} else {
Ok(())
}
}
}
impl<'tcx> PrettyPrinter<'tcx> for FmtPrinter<'_, 'tcx> {
fn ty_infer_name(&self, id: ty::TyVid) -> Option<Symbol> {
self.0.ty_infer_name_resolver.as_ref().and_then(|func| func(id))
}
fn reset_type_limit(&mut self) {
self.printed_type_count = 0;
}
fn const_infer_name(&self, id: ty::ConstVid) -> Option<Symbol> {
self.0.const_infer_name_resolver.as_ref().and_then(|func| func(id))
}
fn pretty_print_value_path(
&mut self,
def_id: DefId,
args: &'tcx [GenericArg<'tcx>],
) -> Result<(), PrintError> {
let was_in_value = std::mem::replace(&mut self.in_value, true);
self.print_def_path(def_id, args)?;
self.in_value = was_in_value;
Ok(())
}
fn pretty_print_in_binder<T>(&mut self, value: &ty::Binder<'tcx, T>) -> Result<(), PrintError>
where
T: Print<'tcx, Self> + TypeFoldable<TyCtxt<'tcx>>,
{
self.wrap_binder(value, WrapBinderMode::ForAll, |new_value, this| new_value.print(this))
}
fn wrap_binder<T, C: FnOnce(&T, &mut Self) -> Result<(), PrintError>>(
&mut self,
value: &ty::Binder<'tcx, T>,
mode: WrapBinderMode,
f: C,
) -> Result<(), PrintError>
where
T: TypeFoldable<TyCtxt<'tcx>>,
{
let old_region_index = self.region_index;
let (new_value, _) = self.name_all_regions(value, mode)?;
f(&new_value, self)?;
self.region_index = old_region_index;
self.binder_depth -= 1;
Ok(())
}
fn typed_value(
&mut self,
f: impl FnOnce(&mut Self) -> Result<(), PrintError>,
t: impl FnOnce(&mut Self) -> Result<(), PrintError>,
conversion: &str,
) -> Result<(), PrintError> {
self.write_str("{")?;
f(self)?;
self.write_str(conversion)?;
let was_in_value = std::mem::replace(&mut self.in_value, false);
t(self)?;
self.in_value = was_in_value;
self.write_str("}")?;
Ok(())
}
fn generic_delimiters(
&mut self,
f: impl FnOnce(&mut Self) -> Result<(), PrintError>,
) -> Result<(), PrintError> {
write!(self, "<")?;
let was_in_value = std::mem::replace(&mut self.in_value, false);
f(self)?;
self.in_value = was_in_value;
write!(self, ">")?;
Ok(())
}
fn should_truncate(&mut self) -> bool {
!self.type_length_limit.value_within_limit(self.printed_type_count)
}
fn should_print_optional_region(&self, region: ty::Region<'tcx>) -> bool {
let highlight = self.region_highlight_mode;
if highlight.region_highlighted(region).is_some() {
return true;
}
if self.should_print_verbose() {
return true;
}
if with_forced_trimmed_paths() {
return false;
}
let identify_regions = self.tcx.sess.opts.unstable_opts.identify_regions;
match region.kind() {
ty::ReEarlyParam(ref data) => data.is_named(),
ty::ReLateParam(ty::LateParamRegion { kind, .. }) => kind.is_named(self.tcx),
ty::ReBound(_, ty::BoundRegion { kind: br, .. })
| ty::RePlaceholder(ty::Placeholder {
bound: ty::BoundRegion { kind: br, .. }, ..
}) => {
if br.is_named(self.tcx) {
return true;
}
if let Some((region, _)) = highlight.highlight_bound_region {
if br == region {
return true;
}
}
false
}
ty::ReVar(_) if identify_regions => true,
ty::ReVar(_) | ty::ReErased | ty::ReError(_) => false,
ty::ReStatic => true,
}
}
fn pretty_print_const_pointer<Prov: Provenance>(
&mut self,
p: Pointer<Prov>,
ty: Ty<'tcx>,
) -> Result<(), PrintError> {
let print = |this: &mut Self| {
if this.print_alloc_ids {
write!(this, "{p:?}")?;
} else {
write!(this, "&_")?;
}
Ok(())
};
self.typed_value(print, |this| this.print_type(ty), ": ")
}
}
// HACK(eddyb) limited to `FmtPrinter` because of `region_highlight_mode`.
impl<'tcx> FmtPrinter<'_, 'tcx> {
pub fn pretty_print_region(&mut self, region: ty::Region<'tcx>) -> Result<(), fmt::Error> {
// Watch out for region highlights.
let highlight = self.region_highlight_mode;
if let Some(n) = highlight.region_highlighted(region) {
write!(self, "'{n}")?;
return Ok(());
}
if self.should_print_verbose() {
write!(self, "{region:?}")?;
return Ok(());
}
let identify_regions = self.tcx.sess.opts.unstable_opts.identify_regions;
// These printouts are concise. They do not contain all the information
// the user might want to diagnose an error, but there is basically no way
// to fit that into a short string. Hence the recommendation to use
// `explain_region()` or `note_and_explain_region()`.
match region.kind() {
ty::ReEarlyParam(data) => {
write!(self, "{}", data.name)?;
return Ok(());
}
ty::ReLateParam(ty::LateParamRegion { kind, .. }) => {
if let Some(name) = kind.get_name(self.tcx) {
write!(self, "{name}")?;
return Ok(());
}
}
ty::ReBound(_, ty::BoundRegion { kind: br, .. })
| ty::RePlaceholder(ty::Placeholder {
bound: ty::BoundRegion { kind: br, .. }, ..
}) => {
if let Some(name) = br.get_name(self.tcx) {
write!(self, "{name}")?;
return Ok(());
}
if let Some((region, counter)) = highlight.highlight_bound_region {
if br == region {
write!(self, "'{counter}")?;
return Ok(());
}
}
}
ty::ReVar(region_vid) if identify_regions => {
write!(self, "{region_vid:?}")?;
return Ok(());
}
ty::ReVar(_) => {}
ty::ReErased => {}
ty::ReError(_) => {}
ty::ReStatic => {
write!(self, "'static")?;
return Ok(());
}
}
write!(self, "'_")?;
Ok(())
}
}
/// Folds through bound vars and placeholders, naming them
struct RegionFolder<'a, 'tcx> {
tcx: TyCtxt<'tcx>,
current_index: ty::DebruijnIndex,
region_map: UnordMap<ty::BoundRegion, ty::Region<'tcx>>,
name: &'a mut (
dyn FnMut(
Option<ty::DebruijnIndex>, // Debruijn index of the folded late-bound region
ty::DebruijnIndex, // Index corresponding to binder level
ty::BoundRegion,
) -> ty::Region<'tcx>
+ 'a
),
}
impl<'a, 'tcx> ty::TypeFolder<TyCtxt<'tcx>> for RegionFolder<'a, 'tcx> {
fn cx(&self) -> TyCtxt<'tcx> {
self.tcx
}
fn fold_binder<T: TypeFoldable<TyCtxt<'tcx>>>(
&mut self,
t: ty::Binder<'tcx, T>,
) -> ty::Binder<'tcx, T> {
self.current_index.shift_in(1);
let t = t.super_fold_with(self);
self.current_index.shift_out(1);
t
}
fn fold_ty(&mut self, t: Ty<'tcx>) -> Ty<'tcx> {
match *t.kind() {
_ if t.has_vars_bound_at_or_above(self.current_index) || t.has_placeholders() => {
return t.super_fold_with(self);
}
_ => {}
}
t
}
fn fold_region(&mut self, r: ty::Region<'tcx>) -> ty::Region<'tcx> {
let name = &mut self.name;
let region = match r.kind() {
ty::ReBound(ty::BoundVarIndexKind::Bound(db), br) if db >= self.current_index => {
*self.region_map.entry(br).or_insert_with(|| name(Some(db), self.current_index, br))
}
ty::RePlaceholder(ty::PlaceholderRegion {
bound: ty::BoundRegion { kind, .. },
..
}) => {
// If this is an anonymous placeholder, don't rename. Otherwise, in some
// async fns, we get a `for<'r> Send` bound
match kind {
ty::BoundRegionKind::Anon | ty::BoundRegionKind::ClosureEnv => r,
_ => {
// Index doesn't matter, since this is just for naming and these never get bound
let br = ty::BoundRegion { var: ty::BoundVar::ZERO, kind };
*self
.region_map
.entry(br)
.or_insert_with(|| name(None, self.current_index, br))
}
}
}
_ => return r,
};
if let ty::ReBound(ty::BoundVarIndexKind::Bound(debruijn1), br) = region.kind() {
assert_eq!(debruijn1, ty::INNERMOST);
ty::Region::new_bound(self.tcx, self.current_index, br)
} else {
region
}
}
}
// HACK(eddyb) limited to `FmtPrinter` because of `binder_depth`,
// `region_index` and `used_region_names`.
impl<'tcx> FmtPrinter<'_, 'tcx> {
pub fn name_all_regions<T>(
&mut self,
value: &ty::Binder<'tcx, T>,
mode: WrapBinderMode,
) -> Result<(T, UnordMap<ty::BoundRegion, ty::Region<'tcx>>), fmt::Error>
where
T: TypeFoldable<TyCtxt<'tcx>>,
{
fn name_by_region_index(
index: usize,
available_names: &mut Vec<Symbol>,
num_available: usize,
) -> Symbol {
if let Some(name) = available_names.pop() {
name
} else {
Symbol::intern(&format!("'z{}", index - num_available))
}
}
debug!("name_all_regions");
// Replace any anonymous late-bound regions with named
// variants, using new unique identifiers, so that we can
// clearly differentiate between named and unnamed regions in
// the output. We'll probably want to tweak this over time to
// decide just how much information to give.
if self.binder_depth == 0 {
self.prepare_region_info(value);
}
debug!("self.used_region_names: {:?}", self.used_region_names);
let mut empty = true;
let mut start_or_continue = |p: &mut Self, start: &str, cont: &str| {
let w = if empty {
empty = false;
start
} else {
cont
};
let _ = write!(p, "{w}");
};
let do_continue = |p: &mut Self, cont: Symbol| {
let _ = write!(p, "{cont}");
};
let possible_names = ('a'..='z').rev().map(|s| Symbol::intern(&format!("'{s}")));
let mut available_names = possible_names
.filter(|name| !self.used_region_names.contains(name))
.collect::<Vec<_>>();
debug!(?available_names);
let num_available = available_names.len();
let mut region_index = self.region_index;
let mut next_name = |this: &Self| {
let mut name;
loop {
name = name_by_region_index(region_index, &mut available_names, num_available);
region_index += 1;
if !this.used_region_names.contains(&name) {
break;
}
}
name
};
// If we want to print verbosely, then print *all* binders, even if they
// aren't named. Eventually, we might just want this as the default, but
// this is not *quite* right and changes the ordering of some output
// anyways.
let (new_value, map) = if self.should_print_verbose() {
for var in value.bound_vars().iter() {
start_or_continue(self, mode.start_str(), ", ");
write!(self, "{var:?}")?;
}
// Unconditionally render `unsafe<>`.
if value.bound_vars().is_empty() && mode == WrapBinderMode::Unsafe {
start_or_continue(self, mode.start_str(), "");
}
start_or_continue(self, "", "> ");
(value.clone().skip_binder(), UnordMap::default())
} else {
let tcx = self.tcx;
let trim_path = with_forced_trimmed_paths();
// Closure used in `RegionFolder` to create names for anonymous late-bound
// regions. We use two `DebruijnIndex`es (one for the currently folded
// late-bound region and the other for the binder level) to determine
// whether a name has already been created for the currently folded region,
// see issue #102392.
let mut name = |lifetime_idx: Option<ty::DebruijnIndex>,
binder_level_idx: ty::DebruijnIndex,
br: ty::BoundRegion| {
let (name, kind) = if let Some(name) = br.kind.get_name(tcx) {
(name, br.kind)
} else {
let name = next_name(self);
(name, ty::BoundRegionKind::NamedAnon(name))
};
if let Some(lt_idx) = lifetime_idx {
if lt_idx > binder_level_idx {
return ty::Region::new_bound(
tcx,
ty::INNERMOST,
ty::BoundRegion { var: br.var, kind },
);
}
}
// Unconditionally render `unsafe<>`.
if !trim_path || mode == WrapBinderMode::Unsafe {
start_or_continue(self, mode.start_str(), ", ");
do_continue(self, name);
}
ty::Region::new_bound(tcx, ty::INNERMOST, ty::BoundRegion { var: br.var, kind })
};
let mut folder = RegionFolder {
tcx,
current_index: ty::INNERMOST,
name: &mut name,
region_map: UnordMap::default(),
};
let new_value = value.clone().skip_binder().fold_with(&mut folder);
let region_map = folder.region_map;
if mode == WrapBinderMode::Unsafe && region_map.is_empty() {
start_or_continue(self, mode.start_str(), "");
}
start_or_continue(self, "", "> ");
(new_value, region_map)
};
self.binder_depth += 1;
self.region_index = region_index;
Ok((new_value, map))
}
fn prepare_region_info<T>(&mut self, value: &ty::Binder<'tcx, T>)
where
T: TypeFoldable<TyCtxt<'tcx>>,
{
struct RegionNameCollector<'tcx> {
tcx: TyCtxt<'tcx>,
used_region_names: FxHashSet<Symbol>,
type_collector: SsoHashSet<Ty<'tcx>>,
}
impl<'tcx> RegionNameCollector<'tcx> {
fn new(tcx: TyCtxt<'tcx>) -> Self {
RegionNameCollector {
tcx,
used_region_names: Default::default(),
type_collector: SsoHashSet::new(),
}
}
}
impl<'tcx> ty::TypeVisitor<TyCtxt<'tcx>> for RegionNameCollector<'tcx> {
fn visit_region(&mut self, r: ty::Region<'tcx>) {
trace!("address: {:p}", r.0.0);
// Collect all named lifetimes. These allow us to prevent duplication
// of already existing lifetime names when introducing names for
// anonymous late-bound regions.
if let Some(name) = r.get_name(self.tcx) {
self.used_region_names.insert(name);
}
}
// We collect types in order to prevent really large types from compiling for
// a really long time. See issue #83150 for why this is necessary.
fn visit_ty(&mut self, ty: Ty<'tcx>) {
let not_previously_inserted = self.type_collector.insert(ty);
if not_previously_inserted {
ty.super_visit_with(self)
}
}
}
let mut collector = RegionNameCollector::new(self.tcx());
value.visit_with(&mut collector);
self.used_region_names = collector.used_region_names;
self.region_index = 0;
}
}
impl<'tcx, T, P: PrettyPrinter<'tcx>> Print<'tcx, P> for ty::Binder<'tcx, T>
where
T: Print<'tcx, P> + TypeFoldable<TyCtxt<'tcx>>,
{
fn print(&self, p: &mut P) -> Result<(), PrintError> {
p.pretty_print_in_binder(self)
}
}
impl<'tcx, T, P: PrettyPrinter<'tcx>> Print<'tcx, P> for ty::OutlivesPredicate<'tcx, T>
where
T: Print<'tcx, P>,
{
fn print(&self, p: &mut P) -> Result<(), PrintError> {
self.0.print(p)?;
write!(p, ": ")?;
self.1.print(p)?;
Ok(())
}
}
/// Wrapper type for `ty::TraitRef` which opts-in to pretty printing only
/// the trait path. That is, it will print `Trait<U>` instead of
/// `<T as Trait<U>>`.
#[derive(Copy, Clone, TypeFoldable, TypeVisitable, Lift, Hash)]
pub struct TraitRefPrintOnlyTraitPath<'tcx>(ty::TraitRef<'tcx>);
impl<'tcx> rustc_errors::IntoDiagArg for TraitRefPrintOnlyTraitPath<'tcx> {
fn into_diag_arg(self, path: &mut Option<std::path::PathBuf>) -> rustc_errors::DiagArgValue {
ty::tls::with(|tcx| {
let trait_ref = tcx.short_string(self, path);
rustc_errors::DiagArgValue::Str(std::borrow::Cow::Owned(trait_ref))
})
}
}
impl<'tcx> fmt::Debug for TraitRefPrintOnlyTraitPath<'tcx> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Display::fmt(self, f)
}
}
/// Wrapper type for `ty::TraitRef` which opts-in to pretty printing only
/// the trait path, and additionally tries to "sugar" `Fn(...)` trait bounds.
#[derive(Copy, Clone, TypeFoldable, TypeVisitable, Lift, Hash)]
pub struct TraitRefPrintSugared<'tcx>(ty::TraitRef<'tcx>);
impl<'tcx> rustc_errors::IntoDiagArg for TraitRefPrintSugared<'tcx> {
fn into_diag_arg(self, path: &mut Option<std::path::PathBuf>) -> rustc_errors::DiagArgValue {
ty::tls::with(|tcx| {
let trait_ref = tcx.short_string(self, path);
rustc_errors::DiagArgValue::Str(std::borrow::Cow::Owned(trait_ref))
})
}
}
impl<'tcx> fmt::Debug for TraitRefPrintSugared<'tcx> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Display::fmt(self, f)
}
}
/// Wrapper type for `ty::TraitRef` which opts-in to pretty printing only
/// the trait name. That is, it will print `Trait` instead of
/// `<T as Trait<U>>`.
#[derive(Copy, Clone, TypeFoldable, TypeVisitable, Lift)]
pub struct TraitRefPrintOnlyTraitName<'tcx>(ty::TraitRef<'tcx>);
impl<'tcx> fmt::Debug for TraitRefPrintOnlyTraitName<'tcx> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Display::fmt(self, f)
}
}
#[extension(pub trait PrintTraitRefExt<'tcx>)]
impl<'tcx> ty::TraitRef<'tcx> {
fn print_only_trait_path(self) -> TraitRefPrintOnlyTraitPath<'tcx> {
TraitRefPrintOnlyTraitPath(self)
}
fn print_trait_sugared(self) -> TraitRefPrintSugared<'tcx> {
TraitRefPrintSugared(self)
}
fn print_only_trait_name(self) -> TraitRefPrintOnlyTraitName<'tcx> {
TraitRefPrintOnlyTraitName(self)
}
}
#[extension(pub trait PrintPolyTraitRefExt<'tcx>)]
impl<'tcx> ty::Binder<'tcx, ty::TraitRef<'tcx>> {
fn print_only_trait_path(self) -> ty::Binder<'tcx, TraitRefPrintOnlyTraitPath<'tcx>> {
self.map_bound(|tr| tr.print_only_trait_path())
}
fn print_trait_sugared(self) -> ty::Binder<'tcx, TraitRefPrintSugared<'tcx>> {
self.map_bound(|tr| tr.print_trait_sugared())
}
}
#[derive(Copy, Clone, TypeFoldable, TypeVisitable, Lift, Hash)]
pub struct TraitPredPrintModifiersAndPath<'tcx>(ty::TraitPredicate<'tcx>);
impl<'tcx> fmt::Debug for TraitPredPrintModifiersAndPath<'tcx> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Display::fmt(self, f)
}
}
#[extension(pub trait PrintTraitPredicateExt<'tcx>)]
impl<'tcx> ty::TraitPredicate<'tcx> {
fn print_modifiers_and_trait_path(self) -> TraitPredPrintModifiersAndPath<'tcx> {
TraitPredPrintModifiersAndPath(self)
}
}
#[derive(Copy, Clone, TypeFoldable, TypeVisitable, Lift, Hash)]
pub struct TraitPredPrintWithBoundConstness<'tcx>(
ty::TraitPredicate<'tcx>,
Option<ty::BoundConstness>,
);
impl<'tcx> fmt::Debug for TraitPredPrintWithBoundConstness<'tcx> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Display::fmt(self, f)
}
}
#[extension(pub trait PrintPolyTraitPredicateExt<'tcx>)]
impl<'tcx> ty::PolyTraitPredicate<'tcx> {
fn print_modifiers_and_trait_path(
self,
) -> ty::Binder<'tcx, TraitPredPrintModifiersAndPath<'tcx>> {
self.map_bound(TraitPredPrintModifiersAndPath)
}
fn print_with_bound_constness(
self,
constness: Option<ty::BoundConstness>,
) -> ty::Binder<'tcx, TraitPredPrintWithBoundConstness<'tcx>> {
self.map_bound(|trait_pred| TraitPredPrintWithBoundConstness(trait_pred, constness))
}
}
#[derive(Debug, Copy, Clone, Lift)]
pub struct PrintClosureAsImpl<'tcx> {
pub closure: ty::ClosureArgs<TyCtxt<'tcx>>,
}
macro_rules! forward_display_to_print {
($($ty:ty),+) => {
// Some of the $ty arguments may not actually use 'tcx
$(#[allow(unused_lifetimes)] impl<'tcx> fmt::Display for $ty {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
ty::tls::with(|tcx| {
let mut p = FmtPrinter::new(tcx, Namespace::TypeNS);
tcx.lift(*self)
.expect("could not lift for printing")
.print(&mut p)?;
f.write_str(&p.into_buffer())?;
Ok(())
})
}
})+
};
}
macro_rules! define_print {
(($self:ident, $p:ident): $($ty:ty $print:block)+) => {
$(impl<'tcx, P: PrettyPrinter<'tcx>> Print<'tcx, P> for $ty {
fn print(&$self, $p: &mut P) -> Result<(), PrintError> {
let _: () = $print;
Ok(())
}
})+
};
}
macro_rules! define_print_and_forward_display {
(($self:ident, $p:ident): $($ty:ty $print:block)+) => {
define_print!(($self, $p): $($ty $print)*);
forward_display_to_print!($($ty),+);
};
}
forward_display_to_print! {
ty::Region<'tcx>,
Ty<'tcx>,
&'tcx ty::List<ty::PolyExistentialPredicate<'tcx>>,
ty::Const<'tcx>
}
define_print! {
(self, p):
ty::FnSig<'tcx> {
write!(p, "{}", self.safety.prefix_str())?;
if self.abi != ExternAbi::Rust {
write!(p, "extern {} ", self.abi)?;
}
write!(p, "fn")?;
p.pretty_print_fn_sig(self.inputs(), self.c_variadic, self.output())?;
}
ty::TraitRef<'tcx> {
write!(p, "<{} as {}>", self.self_ty(), self.print_only_trait_path())?;
}
ty::AliasTy<'tcx> {
let alias_term: ty::AliasTerm<'tcx> = (*self).into();
alias_term.print(p)?;
}
ty::AliasTerm<'tcx> {
match self.kind(p.tcx()) {
ty::AliasTermKind::InherentTy | ty::AliasTermKind::InherentConst => p.pretty_print_inherent_projection(*self)?,
ty::AliasTermKind::ProjectionTy => {
if !(p.should_print_verbose() || with_reduced_queries())
&& p.tcx().is_impl_trait_in_trait(self.def_id)
{
p.pretty_print_rpitit(self.def_id, self.args)?;
} else {
p.print_def_path(self.def_id, self.args)?;
}
}
ty::AliasTermKind::FreeTy
| ty::AliasTermKind::FreeConst
| ty::AliasTermKind::OpaqueTy
| ty::AliasTermKind::UnevaluatedConst
| ty::AliasTermKind::ProjectionConst => {
p.print_def_path(self.def_id, self.args)?;
}
}
}
ty::TraitPredicate<'tcx> {
self.trait_ref.self_ty().print(p)?;
write!(p, ": ")?;
if let ty::PredicatePolarity::Negative = self.polarity {
write!(p, "!")?;
}
self.trait_ref.print_trait_sugared().print(p)?;
}
ty::HostEffectPredicate<'tcx> {
let constness = match self.constness {
ty::BoundConstness::Const => { "const" }
ty::BoundConstness::Maybe => { "[const]" }
};
self.trait_ref.self_ty().print(p)?;
write!(p, ": {constness} ")?;
self.trait_ref.print_trait_sugared().print(p)?;
}
ty::TypeAndMut<'tcx> {
write!(p, "{}", self.mutbl.prefix_str())?;
self.ty.print(p)?;
}
ty::ClauseKind<'tcx> {
match *self {
ty::ClauseKind::Trait(ref data) => data.print(p)?,
ty::ClauseKind::RegionOutlives(predicate) => predicate.print(p)?,
ty::ClauseKind::TypeOutlives(predicate) => predicate.print(p)?,
ty::ClauseKind::Projection(predicate) => predicate.print(p)?,
ty::ClauseKind::HostEffect(predicate) => predicate.print(p)?,
ty::ClauseKind::ConstArgHasType(ct, ty) => {
write!(p, "the constant `")?;
ct.print(p)?;
write!(p, "` has type `")?;
ty.print(p)?;
write!(p, "`")?;
},
ty::ClauseKind::WellFormed(term) => {
term.print(p)?;
write!(p, " well-formed")?;
}
ty::ClauseKind::ConstEvaluatable(ct) => {
write!(p, "the constant `")?;
ct.print(p)?;
write!(p, "` can be evaluated")?;
}
ty::ClauseKind::UnstableFeature(symbol) => {
write!(p, "feature({symbol}) is enabled")?;
}
}
}
ty::PredicateKind<'tcx> {
match *self {
ty::PredicateKind::Clause(data) => data.print(p)?,
ty::PredicateKind::Subtype(predicate) => predicate.print(p)?,
ty::PredicateKind::Coerce(predicate) => predicate.print(p)?,
ty::PredicateKind::DynCompatible(trait_def_id) => {
write!(p, "the trait `")?;
p.print_def_path(trait_def_id, &[])?;
write!(p, "` is dyn-compatible")?;
}
ty::PredicateKind::ConstEquate(c1, c2) => {
write!(p, "the constant `")?;
c1.print(p)?;
write!(p, "` equals `")?;
c2.print(p)?;
write!(p, "`")?;
}
ty::PredicateKind::Ambiguous => write!(p, "ambiguous")?,
ty::PredicateKind::NormalizesTo(data) => data.print(p)?,
ty::PredicateKind::AliasRelate(t1, t2, dir) => {
t1.print(p)?;
write!(p, " {dir} ")?;
t2.print(p)?;
}
}
}
ty::ExistentialPredicate<'tcx> {
match *self {
ty::ExistentialPredicate::Trait(x) => x.print(p)?,
ty::ExistentialPredicate::Projection(x) => x.print(p)?,
ty::ExistentialPredicate::AutoTrait(def_id) => p.print_def_path(def_id, &[])?,
}
}
ty::ExistentialTraitRef<'tcx> {
// Use a type that can't appear in defaults of type parameters.
let dummy_self = Ty::new_fresh(p.tcx(), 0);
let trait_ref = self.with_self_ty(p.tcx(), dummy_self);
trait_ref.print_only_trait_path().print(p)?;
}
ty::ExistentialProjection<'tcx> {
let name = p.tcx().associated_item(self.def_id).name();
// The args don't contain the self ty (as it has been erased) but the corresp.
// generics do as the trait always has a self ty param. We need to offset.
let args = &self.args[p.tcx().generics_of(self.def_id).parent_count - 1..];
p.print_path_with_generic_args(|p| write!(p, "{name}"), args)?;
write!(p, " = ")?;
self.term.print(p)?;
}
ty::ProjectionPredicate<'tcx> {
self.projection_term.print(p)?;
write!(p, " == ")?;
p.reset_type_limit();
self.term.print(p)?;
}
ty::SubtypePredicate<'tcx> {
self.a.print(p)?;
write!(p, " <: ")?;
p.reset_type_limit();
self.b.print(p)?;
}
ty::CoercePredicate<'tcx> {
self.a.print(p)?;
write!(p, " -> ")?;
p.reset_type_limit();
self.b.print(p)?;
}
ty::NormalizesTo<'tcx> {
self.alias.print(p)?;
write!(p, " normalizes-to ")?;
p.reset_type_limit();
self.term.print(p)?;
}
}
define_print_and_forward_display! {
(self, p):
&'tcx ty::List<Ty<'tcx>> {
write!(p, "{{")?;
p.comma_sep(self.iter())?;
write!(p, "}}")?;
}
TraitRefPrintOnlyTraitPath<'tcx> {
p.print_def_path(self.0.def_id, self.0.args)?;
}
TraitRefPrintSugared<'tcx> {
if !with_reduced_queries()
&& p.tcx().trait_def(self.0.def_id).paren_sugar
&& let ty::Tuple(args) = self.0.args.type_at(1).kind()
{
write!(p, "{}(", p.tcx().item_name(self.0.def_id))?;
for (i, arg) in args.iter().enumerate() {
if i > 0 {
write!(p, ", ")?;
}
arg.print(p)?;
}
write!(p, ")")?;
} else {
p.print_def_path(self.0.def_id, self.0.args)?;
}
}
TraitRefPrintOnlyTraitName<'tcx> {
p.print_def_path(self.0.def_id, &[])?;
}
TraitPredPrintModifiersAndPath<'tcx> {
if let ty::PredicatePolarity::Negative = self.0.polarity {
write!(p, "!")?;
}
self.0.trait_ref.print_trait_sugared().print(p)?;
}
TraitPredPrintWithBoundConstness<'tcx> {
self.0.trait_ref.self_ty().print(p)?;
write!(p, ": ")?;
if let Some(constness) = self.1 {
p.pretty_print_bound_constness(constness)?;
}
if let ty::PredicatePolarity::Negative = self.0.polarity {
write!(p, "!")?;
}
self.0.trait_ref.print_trait_sugared().print(p)?;
}
PrintClosureAsImpl<'tcx> {
p.pretty_print_closure_as_impl(self.closure)?;
}
ty::ParamTy {
write!(p, "{}", self.name)?;
}
ty::PlaceholderType {
match self.bound.kind {
ty::BoundTyKind::Anon => write!(p, "{self:?}")?,
ty::BoundTyKind::Param(def_id) => match p.should_print_verbose() {
true => write!(p, "{self:?}")?,
false => write!(p, "{}", p.tcx().item_name(def_id))?,
},
}
}
ty::ParamConst {
write!(p, "{}", self.name)?;
}
ty::Term<'tcx> {
match self.kind() {
ty::TermKind::Ty(ty) => ty.print(p)?,
ty::TermKind::Const(c) => c.print(p)?,
}
}
ty::Predicate<'tcx> {
self.kind().print(p)?;
}
ty::Clause<'tcx> {
self.kind().print(p)?;
}
GenericArg<'tcx> {
match self.kind() {
GenericArgKind::Lifetime(lt) => lt.print(p)?,
GenericArgKind::Type(ty) => ty.print(p)?,
GenericArgKind::Const(ct) => ct.print(p)?,
}
}
}
fn for_each_def(tcx: TyCtxt<'_>, mut collect_fn: impl for<'b> FnMut(&'b Ident, Namespace, DefId)) {
// Iterate all (non-anonymous) local crate items no matter where they are defined.
for id in tcx.hir_free_items() {
if matches!(tcx.def_kind(id.owner_id), DefKind::Use) {
continue;
}
let item = tcx.hir_item(id);
let Some(ident) = item.kind.ident() else { continue };
let def_id = item.owner_id.to_def_id();
let ns = tcx.def_kind(def_id).ns().unwrap_or(Namespace::TypeNS);
collect_fn(&ident, ns, def_id);
}
// Now take care of extern crate items.
let queue = &mut Vec::new();
let mut seen_defs: DefIdSet = Default::default();
for &cnum in tcx.crates(()).iter() {
// Ignore crates that are not direct dependencies.
match tcx.extern_crate(cnum) {
None => continue,
Some(extern_crate) => {
if !extern_crate.is_direct() {
continue;
}
}
}
queue.push(cnum.as_def_id());
}
// Iterate external crate defs but be mindful about visibility
while let Some(def) = queue.pop() {
for child in tcx.module_children(def).iter() {
if !child.vis.is_public() {
continue;
}
match child.res {
def::Res::Def(DefKind::AssocTy, _) => {}
def::Res::Def(DefKind::TyAlias, _) => {}
def::Res::Def(defkind, def_id) => {
if let Some(ns) = defkind.ns() {
collect_fn(&child.ident, ns, def_id);
}
if defkind.is_module_like() && seen_defs.insert(def_id) {
queue.push(def_id);
}
}
_ => {}
}
}
}
}
/// The purpose of this function is to collect public symbols names that are unique across all
/// crates in the build. Later, when printing about types we can use those names instead of the
/// full exported path to them.
///
/// So essentially, if a symbol name can only be imported from one place for a type, and as
/// long as it was not glob-imported anywhere in the current crate, we can trim its printed
/// path and print only the name.
///
/// This has wide implications on error messages with types, for example, shortening
/// `std::vec::Vec` to just `Vec`, as long as there is no other `Vec` importable anywhere.
///
/// The implementation uses similar import discovery logic to that of 'use' suggestions.
///
/// See also [`with_no_trimmed_paths!`].
// this is pub to be able to intra-doc-link it
pub fn trimmed_def_paths(tcx: TyCtxt<'_>, (): ()) -> DefIdMap<Symbol> {
// Trimming paths is expensive and not optimized, since we expect it to only be used for error
// reporting. Record the fact that we did it, so we can abort if we later found it was
// unnecessary.
//
// The `rustc_middle::ty::print::with_no_trimmed_paths` wrapper can be used to suppress this
// checking, in exchange for full paths being formatted.
tcx.sess.record_trimmed_def_paths();
// Once constructed, unique namespace+symbol pairs will have a `Some(_)` entry, while
// non-unique pairs will have a `None` entry.
let unique_symbols_rev: &mut FxIndexMap<(Namespace, Symbol), Option<DefId>> =
&mut FxIndexMap::default();
for symbol_set in tcx.resolutions(()).glob_map.values() {
for symbol in symbol_set {
unique_symbols_rev.insert((Namespace::TypeNS, *symbol), None);
unique_symbols_rev.insert((Namespace::ValueNS, *symbol), None);
unique_symbols_rev.insert((Namespace::MacroNS, *symbol), None);
}
}
for_each_def(tcx, |ident, ns, def_id| match unique_symbols_rev.entry((ns, ident.name)) {
IndexEntry::Occupied(mut v) => match v.get() {
None => {}
Some(existing) => {
if *existing != def_id {
v.insert(None);
}
}
},
IndexEntry::Vacant(v) => {
v.insert(Some(def_id));
}
});
// Put the symbol from all the unique namespace+symbol pairs into `map`.
let mut map: DefIdMap<Symbol> = Default::default();
for ((_, symbol), opt_def_id) in unique_symbols_rev.drain(..) {
use std::collections::hash_map::Entry::{Occupied, Vacant};
if let Some(def_id) = opt_def_id {
match map.entry(def_id) {
Occupied(mut v) => {
// A single DefId can be known under multiple names (e.g.,
// with a `pub use ... as ...;`). We need to ensure that the
// name placed in this map is chosen deterministically, so
// if we find multiple names (`symbol`) resolving to the
// same `def_id`, we prefer the lexicographically smallest
// name.
//
// Any stable ordering would be fine here though.
if *v.get() != symbol && v.get().as_str() > symbol.as_str() {
v.insert(symbol);
}
}
Vacant(v) => {
v.insert(symbol);
}
}
}
}
map
}
pub fn provide(providers: &mut Providers) {
*providers = Providers { trimmed_def_paths, ..*providers };
}
pub struct OpaqueFnEntry<'tcx> {
kind: ty::ClosureKind,
return_ty: Option<ty::Binder<'tcx, Term<'tcx>>>,
}