blob: 3809c8d245bbe96ebbb682fe13ff81cdabfe0366 [file] [log] [blame]
use crate::middle::cstore::{ExternCrate, ExternCrateSource};
use crate::mir::interpret::{AllocId, ConstValue, GlobalAlloc, Pointer, Scalar};
use crate::ty::layout::IntegerExt;
use crate::ty::subst::{GenericArg, GenericArgKind, Subst};
use crate::ty::{self, ConstInt, DefIdTree, ParamConst, Ty, TyCtxt, TypeFoldable};
use rustc_apfloat::ieee::{Double, Single};
use rustc_apfloat::Float;
use rustc_ast::ast;
use rustc_attr::{SignedInt, UnsignedInt};
use rustc_hir as hir;
use rustc_hir::def::{CtorKind, DefKind, Namespace};
use rustc_hir::def_id::{CrateNum, DefId, CRATE_DEF_INDEX, LOCAL_CRATE};
use rustc_hir::definitions::{DefPathData, DisambiguatedDefPathData};
use rustc_span::symbol::{kw, Ident, Symbol};
use rustc_target::abi::{Integer, Size};
use rustc_target::spec::abi::Abi;
use std::cell::Cell;
use std::char;
use std::collections::BTreeMap;
use std::fmt::{self, Write as _};
use std::ops::{Deref, DerefMut};
// `pretty` is a separate module only for organization.
use super::*;
macro_rules! p {
(@write($($data:expr),+)) => {
write!(scoped_cx!(), $($data),+)?
};
(@print($x:expr)) => {
scoped_cx!() = $x.print(scoped_cx!())?
};
(@$method:ident($($arg:expr),*)) => {
scoped_cx!() = scoped_cx!().$method($($arg),*)?
};
($($kind:ident $data:tt),+) => {{
$(p!(@$kind $data);)+
}};
}
macro_rules! define_scoped_cx {
($cx:ident) => {
#[allow(unused_macros)]
macro_rules! scoped_cx {
() => {
$cx
};
}
};
}
thread_local! {
static FORCE_IMPL_FILENAME_LINE: Cell<bool> = Cell::new(false);
static SHOULD_PREFIX_WITH_CRATE: Cell<bool> = Cell::new(false);
static NO_QUERIES: Cell<bool> = Cell::new(false);
}
/// Avoids running any 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. `predicates_of`
/// for opaque types), to ensure that any debug printing that
/// occurs during the query computation does not end up recursively
/// calling the same query.
pub fn with_no_queries<F: FnOnce() -> R, R>(f: F) -> R {
NO_QUERIES.with(|no_queries| {
let old = no_queries.replace(true);
let result = f();
no_queries.set(old);
result
})
}
/// 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.
pub fn with_forced_impl_filename_line<F: FnOnce() -> R, R>(f: F) -> R {
FORCE_IMPL_FILENAME_LINE.with(|force| {
let old = force.replace(true);
let result = f();
force.set(old);
result
})
}
/// Adds the `crate::` prefix to paths where appropriate.
pub fn with_crate_prefix<F: FnOnce() -> R, R>(f: F) -> R {
SHOULD_PREFIX_WITH_CRATE.with(|flag| {
let old = flag.replace(true);
let result = f();
flag.set(old);
result
})
}
/// 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 {
/// If enabled, when we see the selected region, use "`'N`"
/// instead of the ordinary behavior.
highlight_regions: [Option<(ty::RegionKind, usize)>; 3],
/// If enabled, when printing a "free region" that originated from
/// the given `ty::BoundRegion`, 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::BoundRegion, usize)>,
}
impl RegionHighlightMode {
/// If `region` and `number` are both `Some`, invokes
/// `highlighting_region`.
pub fn maybe_highlighting_region(
&mut self,
region: Option<ty::Region<'_>>,
number: Option<usize>,
) {
if let Some(k) = region {
if 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<'_>, 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, vid: ty::RegionVid, number: usize) {
self.highlighting_region(&ty::ReVar(vid), number)
}
/// Returns `Some(n)` with the number to use for the given region, if any.
fn region_highlighted(&self, region: ty::Region<'_>) -> 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::BoundRegion, 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,
Error = fmt::Error,
Path = Self,
Region = Self,
Type = Self,
DynExistential = Self,
Const = Self,
> + fmt::Write
{
/// Like `print_def_path` but for value paths.
fn print_value_path(
self,
def_id: DefId,
substs: &'tcx [GenericArg<'tcx>],
) -> Result<Self::Path, Self::Error> {
self.print_def_path(def_id, substs)
}
fn in_binder<T>(self, value: &ty::Binder<T>) -> Result<Self, Self::Error>
where
T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<'tcx>,
{
value.as_ref().skip_binder().print(self)
}
/// Prints comma-separated elements.
fn comma_sep<T>(mut self, mut elems: impl Iterator<Item = T>) -> Result<Self, Self::Error>
where
T: Print<'tcx, Self, Output = Self, Error = Self::Error>,
{
if let Some(first) = elems.next() {
self = first.print(self)?;
for elem in elems {
self.write_str(", ")?;
self = elem.print(self)?;
}
}
Ok(self)
}
/// Prints `{f: t}` or `{f as t}` depending on the `cast` argument
fn typed_value(
mut self,
f: impl FnOnce(Self) -> Result<Self, Self::Error>,
t: impl FnOnce(Self) -> Result<Self, Self::Error>,
conversion: &str,
) -> Result<Self::Const, Self::Error> {
self.write_str("{")?;
self = f(self)?;
self.write_str(conversion)?;
self = t(self)?;
self.write_str("}")?;
Ok(self)
}
/// Prints `<...>` around what `f` prints.
fn generic_delimiters(
self,
f: impl FnOnce(Self) -> Result<Self, Self::Error>,
) -> Result<Self, Self::Error>;
/// Returns `true` if the region should be printed in
/// optional positions, e.g., `&'a T` or `dyn Tr + 'b`.
/// This is typically the case for all non-`'_` regions.
fn region_should_not_be_omitted(&self, region: ty::Region<'_>) -> bool;
// 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(self, def_id: DefId) -> Result<(Self, bool), Self::Error> {
let mut callers = Vec::new();
self.try_print_visible_def_path_recur(def_id, &mut callers)
}
/// 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.
fn try_print_visible_def_path_recur(
mut self,
def_id: DefId,
callers: &mut Vec<DefId>,
) -> Result<(Self, bool), Self::Error> {
define_scoped_cx!(self);
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 def_id.index == CRATE_DEF_INDEX {
let cnum = def_id.krate;
if cnum == LOCAL_CRATE {
return Ok((self.path_crate(cnum)?, 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(def_id) {
Some(&ExternCrate { src, dependency_of, span, .. }) => match (src, dependency_of) {
(ExternCrateSource::Extern(def_id), LOCAL_CRATE) => {
debug!("try_print_visible_def_path: def_id={:?}", def_id);
return Ok((
if !span.is_dummy() {
self.print_def_path(def_id, &[])?
} else {
self.path_crate(cnum)?
},
true,
));
}
(ExternCrateSource::Path, LOCAL_CRATE) => {
debug!("try_print_visible_def_path: def_id={:?}", def_id);
return Ok((self.path_crate(cnum)?, true));
}
_ => {}
},
None => {
return Ok((self.path_crate(cnum)?, true));
}
}
}
if def_id.is_local() {
return Ok((self, false));
}
let visible_parent_map = self.tcx().visible_parent_map(LOCAL_CRATE);
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 visible_parent = match visible_parent_map.get(&def_id).cloned() {
Some(parent) => parent,
None => return Ok((self, false)),
};
if callers.contains(&visible_parent) {
return Ok((self, false));
}
callers.push(visible_parent);
// HACK(eddyb) this bypasses `path_append`'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)? {
(cx, false) => return Ok((cx, false)),
(cx, true) => self = cx,
}
callers.pop();
let actual_parent = self.tcx().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` rexports 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 => {
let reexport = self
.tcx()
.item_children(visible_parent)
.iter()
.find(|child| child.res.opt_def_id() == Some(def_id))
.map(|child| child.ident.name);
if let Some(reexport) = reexport {
*name = reexport;
}
}
// Re-exported `extern crate` (#43189).
DefPathData::CrateRoot => {
data = DefPathData::TypeNs(self.tcx().original_crate_name(def_id.krate));
}
_ => {}
}
debug!("try_print_visible_def_path: data={:?}", data);
Ok((self.path_append(Ok, &DisambiguatedDefPathData { data, disambiguator: 0 })?, true))
}
fn pretty_path_qualified(
self,
self_ty: Ty<'tcx>,
trait_ref: Option<ty::TraitRef<'tcx>>,
) -> Result<Self::Path, Self::Error> {
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(|mut cx| {
define_scoped_cx!(cx);
p!(print(self_ty));
if let Some(trait_ref) = trait_ref {
p!(write(" as "), print(trait_ref.print_only_trait_path()));
}
Ok(cx)
})
}
fn pretty_path_append_impl(
mut self,
print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
self_ty: Ty<'tcx>,
trait_ref: Option<ty::TraitRef<'tcx>>,
) -> Result<Self::Path, Self::Error> {
self = print_prefix(self)?;
self.generic_delimiters(|mut cx| {
define_scoped_cx!(cx);
p!(write("impl "));
if let Some(trait_ref) = trait_ref {
p!(print(trait_ref.print_only_trait_path()), write(" for "));
}
p!(print(self_ty));
Ok(cx)
})
}
fn pretty_print_type(mut self, ty: Ty<'tcx>) -> Result<Self::Type, Self::Error> {
define_scoped_cx!(self);
match ty.kind {
ty::Bool => p!(write("bool")),
ty::Char => p!(write("char")),
ty::Int(t) => p!(write("{}", t.name_str())),
ty::Uint(t) => p!(write("{}", t.name_str())),
ty::Float(t) => p!(write("{}", t.name_str())),
ty::RawPtr(ref tm) => {
p!(write(
"*{} ",
match tm.mutbl {
hir::Mutability::Mut => "mut",
hir::Mutability::Not => "const",
}
));
p!(print(tm.ty))
}
ty::Ref(r, ty, mutbl) => {
p!(write("&"));
if self.region_should_not_be_omitted(r) {
p!(print(r), write(" "));
}
p!(print(ty::TypeAndMut { ty, mutbl }))
}
ty::Never => p!(write("!")),
ty::Tuple(ref tys) => {
p!(write("("), comma_sep(tys.iter()));
if tys.len() == 1 {
p!(write(","));
}
p!(write(")"))
}
ty::FnDef(def_id, substs) => {
let sig = self.tcx().fn_sig(def_id).subst(self.tcx(), substs);
p!(print(sig), write(" {{"), print_value_path(def_id, substs), write("}}"));
}
ty::FnPtr(ref bare_fn) => p!(print(bare_fn)),
ty::Infer(infer_ty) => {
if let ty::TyVar(ty_vid) = infer_ty {
if let Some(name) = self.infer_ty_name(ty_vid) {
p!(write("{}", name))
} else {
p!(write("{}", infer_ty))
}
} else {
p!(write("{}", infer_ty))
}
}
ty::Error(_) => p!(write("[type error]")),
ty::Param(ref param_ty) => p!(write("{}", param_ty)),
ty::Bound(debruijn, bound_ty) => match bound_ty.kind {
ty::BoundTyKind::Anon => self.pretty_print_bound_var(debruijn, bound_ty.var)?,
ty::BoundTyKind::Param(p) => p!(write("{}", p)),
},
ty::Adt(def, substs) => {
p!(print_def_path(def.did, substs));
}
ty::Dynamic(data, r) => {
let print_r = self.region_should_not_be_omitted(r);
if print_r {
p!(write("("));
}
p!(write("dyn "), print(data));
if print_r {
p!(write(" + "), print(r), write(")"));
}
}
ty::Foreign(def_id) => {
p!(print_def_path(def_id, &[]));
}
ty::Projection(ref data) => p!(print(data)),
ty::Placeholder(placeholder) => p!(write("Placeholder({:?})", placeholder)),
ty::Opaque(def_id, substs) => {
// FIXME(eddyb) print this with `print_def_path`.
// 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.
if self.tcx().sess.verbose() || NO_QUERIES.with(|q| q.get()) {
p!(write("Opaque({:?}, {:?})", def_id, substs));
return Ok(self);
}
return Ok(with_no_queries(|| {
let def_key = self.tcx().def_key(def_id);
if let Some(name) = def_key.disambiguated_data.data.get_opt_name() {
p!(write("{}", name));
// FIXME(eddyb) print this with `print_def_path`.
if !substs.is_empty() {
p!(write("::"));
p!(generic_delimiters(|cx| cx.comma_sep(substs.iter())));
}
return Ok(self);
}
// Grab the "TraitA + TraitB" from `impl TraitA + TraitB`,
// by looking up the projections associated with the def_id.
let bounds = self.tcx().predicates_of(def_id).instantiate(self.tcx(), substs);
let mut first = true;
let mut is_sized = false;
p!(write("impl"));
for predicate in bounds.predicates {
if let Some(trait_ref) = predicate.to_opt_poly_trait_ref() {
// Don't print +Sized, but rather +?Sized if absent.
if Some(trait_ref.def_id()) == self.tcx().lang_items().sized_trait() {
is_sized = true;
continue;
}
p!(
write("{}", if first { " " } else { "+" }),
print(trait_ref.print_only_trait_path())
);
first = false;
}
}
if !is_sized {
p!(write("{}?Sized", if first { " " } else { "+" }));
} else if first {
p!(write(" Sized"));
}
Ok(self)
})?);
}
ty::Str => p!(write("str")),
ty::Generator(did, substs, movability) => {
match movability {
hir::Movability::Movable => p!(write("[generator")),
hir::Movability::Static => p!(write("[static generator")),
}
// FIXME(eddyb) should use `def_span`.
if let Some(did) = did.as_local() {
let hir_id = self.tcx().hir().as_local_hir_id(did);
let span = self.tcx().hir().span(hir_id);
p!(write("@{}", self.tcx().sess.source_map().span_to_string(span)));
if substs.as_generator().is_valid() {
let upvar_tys = substs.as_generator().upvar_tys();
let mut sep = " ";
for (&var_id, upvar_ty) in self
.tcx()
.upvars_mentioned(did)
.as_ref()
.iter()
.flat_map(|v| v.keys())
.zip(upvar_tys)
{
p!(write("{}{}:", sep, self.tcx().hir().name(var_id)), print(upvar_ty));
sep = ", ";
}
}
} else {
p!(write("@{}", self.tcx().def_path_str(did)));
if substs.as_generator().is_valid() {
let upvar_tys = substs.as_generator().upvar_tys();
let mut sep = " ";
for (index, upvar_ty) in upvar_tys.enumerate() {
p!(write("{}{}:", sep, index), print(upvar_ty));
sep = ", ";
}
}
}
if substs.as_generator().is_valid() {
p!(write(" "), print(substs.as_generator().witness()));
}
p!(write("]"))
}
ty::GeneratorWitness(types) => {
p!(in_binder(&types));
}
ty::Closure(did, substs) => {
p!(write("[closure"));
// FIXME(eddyb) should use `def_span`.
if let Some(did) = did.as_local() {
let hir_id = self.tcx().hir().as_local_hir_id(did);
if self.tcx().sess.opts.debugging_opts.span_free_formats {
p!(write("@"), print_def_path(did.to_def_id(), substs));
} else {
let span = self.tcx().hir().span(hir_id);
p!(write("@{}", self.tcx().sess.source_map().span_to_string(span)));
}
if substs.as_closure().is_valid() {
let upvar_tys = substs.as_closure().upvar_tys();
let mut sep = " ";
for (&var_id, upvar_ty) in self
.tcx()
.upvars_mentioned(did)
.as_ref()
.iter()
.flat_map(|v| v.keys())
.zip(upvar_tys)
{
p!(write("{}{}:", sep, self.tcx().hir().name(var_id)), print(upvar_ty));
sep = ", ";
}
}
} else {
p!(write("@{}", self.tcx().def_path_str(did)));
if substs.as_closure().is_valid() {
let upvar_tys = substs.as_closure().upvar_tys();
let mut sep = " ";
for (index, upvar_ty) in upvar_tys.enumerate() {
p!(write("{}{}:", sep, index), print(upvar_ty));
sep = ", ";
}
}
}
if self.tcx().sess.verbose() && substs.as_closure().is_valid() {
p!(write(" closure_kind_ty="), print(substs.as_closure().kind_ty()));
p!(
write(" closure_sig_as_fn_ptr_ty="),
print(substs.as_closure().sig_as_fn_ptr_ty())
);
}
p!(write("]"))
}
ty::Array(ty, sz) => {
p!(write("["), print(ty), write("; "));
if self.tcx().sess.verbose() {
p!(write("{:?}", sz));
} else if let ty::ConstKind::Unevaluated(..) = sz.val {
// Do not try to evaluate unevaluated constants. If we are const evaluating an
// array length anon const, rustc will (with debug assertions) print the
// constant's path. Which will end up here again.
p!(write("_"));
} else if let Some(n) = sz.val.try_to_bits(self.tcx().data_layout.pointer_size) {
p!(write("{}", n));
} else if let ty::ConstKind::Param(param) = sz.val {
p!(write("{}", param));
} else {
p!(write("_"));
}
p!(write("]"))
}
ty::Slice(ty) => p!(write("["), print(ty), write("]")),
}
Ok(self)
}
fn pretty_print_bound_var(
&mut self,
debruijn: ty::DebruijnIndex,
var: ty::BoundVar,
) -> Result<(), Self::Error> {
if debruijn == ty::INNERMOST {
write!(self, "^{}", var.index())
} else {
write!(self, "^{}_{}", debruijn.index(), var.index())
}
}
fn infer_ty_name(&self, _: ty::TyVid) -> Option<String> {
None
}
fn pretty_print_dyn_existential(
mut self,
predicates: &'tcx ty::List<ty::ExistentialPredicate<'tcx>>,
) -> Result<Self::DynExistential, Self::Error> {
define_scoped_cx!(self);
// Generate the main trait ref, including associated types.
let mut first = true;
if let Some(principal) = predicates.principal() {
p!(print_def_path(principal.def_id, &[]));
let mut resugared = false;
// Special-case `Fn(...) -> ...` and resugar it.
let fn_trait_kind = self.tcx().fn_trait_kind_from_lang_item(principal.def_id);
if !self.tcx().sess.verbose() && fn_trait_kind.is_some() {
if let ty::Tuple(ref args) = principal.substs.type_at(0).kind {
let mut projections = predicates.projection_bounds();
if let (Some(proj), None) = (projections.next(), projections.next()) {
let tys: Vec<_> = args.iter().map(|k| k.expect_ty()).collect();
p!(pretty_fn_sig(&tys, false, proj.ty));
resugared = true;
}
}
}
// HACK(eddyb) this duplicates `FmtPrinter`'s `path_generic_args`,
// in order to place the projections inside the `<...>`.
if !resugared {
// Use a type that can't appear in defaults of type parameters.
let dummy_self = self.tcx().mk_ty_infer(ty::FreshTy(0));
let principal = principal.with_self_ty(self.tcx(), dummy_self);
let args = self.generic_args_to_print(
self.tcx().generics_of(principal.def_id),
principal.substs,
);
// Don't print `'_` if there's no unerased regions.
let print_regions = args.iter().any(|arg| match arg.unpack() {
GenericArgKind::Lifetime(r) => *r != ty::ReErased,
_ => false,
});
let mut args = args.iter().cloned().filter(|arg| match arg.unpack() {
GenericArgKind::Lifetime(_) => print_regions,
_ => true,
});
let mut projections = predicates.projection_bounds();
let arg0 = args.next();
let projection0 = projections.next();
if arg0.is_some() || projection0.is_some() {
let args = arg0.into_iter().chain(args);
let projections = projection0.into_iter().chain(projections);
p!(generic_delimiters(|mut cx| {
cx = cx.comma_sep(args)?;
if arg0.is_some() && projection0.is_some() {
write!(cx, ", ")?;
}
cx.comma_sep(projections)
}));
}
}
first = false;
}
// Builtin bounds.
// FIXME(eddyb) avoid printing twice (needed to ensure
// that the auto traits are sorted *and* printed via cx).
let mut auto_traits: Vec<_> =
predicates.auto_traits().map(|did| (self.tcx().def_path_str(did), did)).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 that causing instabilities in compiletest
// output, sort the auto-traits alphabetically.
auto_traits.sort();
for (_, def_id) in auto_traits {
if !first {
p!(write(" + "));
}
first = false;
p!(print_def_path(def_id, &[]));
}
Ok(self)
}
fn pretty_fn_sig(
mut self,
inputs: &[Ty<'tcx>],
c_variadic: bool,
output: Ty<'tcx>,
) -> Result<Self, Self::Error> {
define_scoped_cx!(self);
p!(write("("), comma_sep(inputs.iter().copied()));
if c_variadic {
if !inputs.is_empty() {
p!(write(", "));
}
p!(write("..."));
}
p!(write(")"));
if !output.is_unit() {
p!(write(" -> "), print(output));
}
Ok(self)
}
fn pretty_print_const(
mut self,
ct: &'tcx ty::Const<'tcx>,
print_ty: bool,
) -> Result<Self::Const, Self::Error> {
define_scoped_cx!(self);
if self.tcx().sess.verbose() {
p!(write("Const({:?}: {:?})", ct.val, ct.ty));
return Ok(self);
}
macro_rules! print_underscore {
() => {{
if print_ty {
self = self.typed_value(
|mut this| {
write!(this, "_")?;
Ok(this)
},
|this| this.print_type(ct.ty),
": ",
)?;
} else {
write!(self, "_")?;
}
}};
}
match ct.val {
ty::ConstKind::Unevaluated(did, substs, promoted) => {
if let Some(promoted) = promoted {
p!(print_value_path(did, substs));
p!(write("::{:?}", promoted));
} else {
match self.tcx().def_kind(did) {
DefKind::Static | DefKind::Const | DefKind::AssocConst => {
p!(print_value_path(did, substs))
}
_ => {
if did.is_local() {
let span = self.tcx().def_span(did);
if let Ok(snip) = self.tcx().sess.source_map().span_to_snippet(span)
{
p!(write("{}", snip))
} else {
print_underscore!()
}
} else {
print_underscore!()
}
}
}
}
}
ty::ConstKind::Infer(..) => print_underscore!(),
ty::ConstKind::Param(ParamConst { name, .. }) => p!(write("{}", name)),
ty::ConstKind::Value(value) => {
return self.pretty_print_const_value(value, ct.ty, print_ty);
}
ty::ConstKind::Bound(debruijn, bound_var) => {
self.pretty_print_bound_var(debruijn, bound_var)?
}
ty::ConstKind::Placeholder(placeholder) => p!(write("Placeholder({:?})", placeholder)),
ty::ConstKind::Error(_) => p!(write("[const error]")),
};
Ok(self)
}
fn pretty_print_const_scalar(
mut self,
scalar: Scalar,
ty: Ty<'tcx>,
print_ty: bool,
) -> Result<Self::Const, Self::Error> {
define_scoped_cx!(self);
match (scalar, &ty.kind) {
// Byte strings (&[u8; N])
(
Scalar::Ptr(ptr),
ty::Ref(
_,
ty::TyS {
kind:
ty::Array(
ty::TyS { kind: ty::Uint(ast::UintTy::U8), .. },
ty::Const {
val:
ty::ConstKind::Value(ConstValue::Scalar(Scalar::Raw {
data,
..
})),
..
},
),
..
},
_,
),
) => match self.tcx().get_global_alloc(ptr.alloc_id) {
Some(GlobalAlloc::Memory(alloc)) => {
if let Ok(byte_str) = alloc.get_bytes(&self.tcx(), ptr, Size::from_bytes(*data))
{
p!(pretty_print_byte_str(byte_str))
} else {
p!(write("<too short allocation>"))
}
}
// FIXME: for statics and functions, we could in principle print more detail.
Some(GlobalAlloc::Static(def_id)) => p!(write("<static({:?})>", def_id)),
Some(GlobalAlloc::Function(_)) => p!(write("<function>")),
None => p!(write("<dangling pointer>")),
},
// Bool
(Scalar::Raw { data: 0, .. }, ty::Bool) => p!(write("false")),
(Scalar::Raw { data: 1, .. }, ty::Bool) => p!(write("true")),
// Float
(Scalar::Raw { data, .. }, ty::Float(ast::FloatTy::F32)) => {
p!(write("{}f32", Single::from_bits(data)))
}
(Scalar::Raw { data, .. }, ty::Float(ast::FloatTy::F64)) => {
p!(write("{}f64", Double::from_bits(data)))
}
// Int
(Scalar::Raw { data, .. }, ty::Uint(ui)) => {
let size = Integer::from_attr(&self.tcx(), UnsignedInt(*ui)).size();
let int = ConstInt::new(data, size, false, ty.is_ptr_sized_integral());
if print_ty { p!(write("{:#?}", int)) } else { p!(write("{:?}", int)) }
}
(Scalar::Raw { data, .. }, ty::Int(i)) => {
let size = Integer::from_attr(&self.tcx(), SignedInt(*i)).size();
let int = ConstInt::new(data, size, true, ty.is_ptr_sized_integral());
if print_ty { p!(write("{:#?}", int)) } else { p!(write("{:?}", int)) }
}
// Char
(Scalar::Raw { data, .. }, ty::Char) if char::from_u32(data as u32).is_some() => {
p!(write("{:?}", char::from_u32(data as u32).unwrap()))
}
// Raw pointers
(Scalar::Raw { data, .. }, ty::RawPtr(_)) => {
self = self.typed_value(
|mut this| {
write!(this, "0x{:x}", data)?;
Ok(this)
},
|this| this.print_type(ty),
" as ",
)?;
}
(Scalar::Ptr(ptr), ty::FnPtr(_)) => {
// FIXME: this can ICE when the ptr is dangling or points to a non-function.
// 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).
let instance = self.tcx().global_alloc(ptr.alloc_id).unwrap_fn();
self = self.typed_value(
|this| this.print_value_path(instance.def_id(), instance.substs),
|this| this.print_type(ty),
" as ",
)?;
}
// For function type zsts just printing the path is enough
(Scalar::Raw { size: 0, .. }, ty::FnDef(d, s)) => p!(print_value_path(*d, s)),
// Nontrivial types with scalar bit representation
(Scalar::Raw { data, size }, _) => {
let print = |mut this: Self| {
if size == 0 {
write!(this, "transmute(())")?;
} else {
write!(this, "transmute(0x{:01$x})", data, size as usize * 2)?;
}
Ok(this)
};
self = if print_ty {
self.typed_value(print, |this| this.print_type(ty), ": ")?
} else {
print(self)?
};
}
// Any pointer values not covered by a branch above
(Scalar::Ptr(p), _) => {
self = self.pretty_print_const_pointer(p, ty, print_ty)?;
}
}
Ok(self)
}
/// 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(
mut self,
_: Pointer,
ty: Ty<'tcx>,
print_ty: bool,
) -> Result<Self::Const, Self::Error> {
if print_ty {
self.typed_value(
|mut this| {
this.write_str("&_")?;
Ok(this)
},
|this| this.print_type(ty),
": ",
)
} else {
self.write_str("&_")?;
Ok(self)
}
}
fn pretty_print_byte_str(mut self, byte_str: &'tcx [u8]) -> Result<Self::Const, Self::Error> {
define_scoped_cx!(self);
p!(write("b\""));
for &c in byte_str {
for e in std::ascii::escape_default(c) {
self.write_char(e as char)?;
}
}
p!(write("\""));
Ok(self)
}
fn pretty_print_const_value(
mut self,
ct: ConstValue<'tcx>,
ty: Ty<'tcx>,
print_ty: bool,
) -> Result<Self::Const, Self::Error> {
define_scoped_cx!(self);
if self.tcx().sess.verbose() {
p!(write("ConstValue({:?}: ", ct), print(ty), write(")"));
return Ok(self);
}
let u8_type = self.tcx().types.u8;
match (ct, &ty.kind) {
// Byte/string slices, printed as (byte) string literals.
(
ConstValue::Slice { data, start, end },
ty::Ref(_, ty::TyS { kind: ty::Slice(t), .. }, _),
) if *t == u8_type => {
// The `inspect` here is okay since we checked the bounds, and there are
// no relocations (we have an active slice reference here). We don't use
// this result to affect interpreter execution.
let byte_str = data.inspect_with_undef_and_ptr_outside_interpreter(start..end);
self.pretty_print_byte_str(byte_str)
}
(
ConstValue::Slice { data, start, end },
ty::Ref(_, ty::TyS { kind: ty::Str, .. }, _),
) => {
// The `inspect` here is okay since we checked the bounds, and there are no
// relocations (we have an active `str` reference here). We don't use this
// result to affect interpreter execution.
let slice = data.inspect_with_undef_and_ptr_outside_interpreter(start..end);
let s = ::std::str::from_utf8(slice).expect("non utf8 str from miri");
p!(write("{:?}", s));
Ok(self)
}
(ConstValue::ByRef { alloc, offset }, ty::Array(t, n)) if *t == u8_type => {
let n = n.val.try_to_bits(self.tcx().data_layout.pointer_size).unwrap();
// cast is ok because we already checked for pointer size (32 or 64 bit) above
let n = Size::from_bytes(n);
let ptr = Pointer::new(AllocId(0), offset);
let byte_str = alloc.get_bytes(&self.tcx(), ptr, n).unwrap();
p!(write("*"));
p!(pretty_print_byte_str(byte_str));
Ok(self)
}
// Aggregates, printed as array/tuple/struct/variant construction syntax.
//
// NB: the `has_param_types_or_consts` check ensures that we can use
// the `destructure_const` query with an empty `ty::ParamEnv` without
// introducing ICEs (e.g. via `layout_of`) from missing bounds.
// E.g. `transmute([0usize; 2]): (u8, *mut T)` needs to know `T: Sized`
// to be able to destructure the tuple into `(0u8, *mut T)
//
// FIXME(eddyb) for `--emit=mir`/`-Z dump-mir`, we should provide the
// correct `ty::ParamEnv` to allow printing *all* constant values.
(_, ty::Array(..) | ty::Tuple(..) | ty::Adt(..)) if !ty.has_param_types_or_consts() => {
let contents = self.tcx().destructure_const(
ty::ParamEnv::reveal_all()
.and(self.tcx().mk_const(ty::Const { val: ty::ConstKind::Value(ct), ty })),
);
let fields = contents.fields.iter().copied();
match ty.kind {
ty::Array(..) => {
p!(write("["), comma_sep(fields), write("]"));
}
ty::Tuple(..) => {
p!(write("("), comma_sep(fields));
if contents.fields.len() == 1 {
p!(write(","));
}
p!(write(")"));
}
ty::Adt(def, substs) if def.variants.is_empty() => {
p!(print_value_path(def.did, substs));
}
ty::Adt(def, substs) => {
let variant_id =
contents.variant.expect("destructed const of adt without variant id");
let variant_def = &def.variants[variant_id];
p!(print_value_path(variant_def.def_id, substs));
match variant_def.ctor_kind {
CtorKind::Const => {}
CtorKind::Fn => {
p!(write("("), comma_sep(fields), write(")"));
}
CtorKind::Fictive => {
p!(write(" {{ "));
let mut first = true;
for (field_def, field) in variant_def.fields.iter().zip(fields) {
if !first {
p!(write(", "));
}
p!(write("{}: ", field_def.ident), print(field));
first = false;
}
p!(write(" }}"));
}
}
}
_ => unreachable!(),
}
Ok(self)
}
(ConstValue::Scalar(scalar), _) => self.pretty_print_const_scalar(scalar, ty, print_ty),
// FIXME(oli-obk): also pretty print arrays and other aggregate constants by reading
// their fields instead of just dumping the memory.
_ => {
// fallback
p!(write("{:?}", ct));
if print_ty {
p!(write(": "), print(ty));
}
Ok(self)
}
}
}
}
// HACK(eddyb) boxed to avoid moving around a large struct by-value.
pub struct FmtPrinter<'a, 'tcx, F>(Box<FmtPrinterData<'a, 'tcx, F>>);
pub struct FmtPrinterData<'a, 'tcx, F> {
tcx: TyCtxt<'tcx>,
fmt: F,
empty_path: bool,
in_value: bool,
pub print_alloc_ids: bool,
used_region_names: FxHashSet<Symbol>,
region_index: usize,
binder_depth: usize,
pub region_highlight_mode: RegionHighlightMode,
pub name_resolver: Option<Box<&'a dyn Fn(ty::sty::TyVid) -> Option<String>>>,
}
impl<F> Deref for FmtPrinter<'a, 'tcx, F> {
type Target = FmtPrinterData<'a, 'tcx, F>;
fn deref(&self) -> &Self::Target {
&self.0
}
}
impl<F> DerefMut for FmtPrinter<'_, '_, F> {
fn deref_mut(&mut self) -> &mut Self::Target {
&mut self.0
}
}
impl<F> FmtPrinter<'a, 'tcx, F> {
pub fn new(tcx: TyCtxt<'tcx>, fmt: F, ns: Namespace) -> Self {
FmtPrinter(Box::new(FmtPrinterData {
tcx,
fmt,
empty_path: false,
in_value: ns == Namespace::ValueNS,
print_alloc_ids: false,
used_region_names: Default::default(),
region_index: 0,
binder_depth: 0,
region_highlight_mode: RegionHighlightMode::default(),
name_resolver: None,
}))
}
}
// HACK(eddyb) get rid of `def_path_str` and/or pass `Namespace` explicitly always
// (but also some things just print a `DefId` generally so maybe we need this?)
fn guess_def_namespace(tcx: TyCtxt<'_>, def_id: DefId) -> Namespace {
match tcx.def_key(def_id).disambiguated_data.data {
DefPathData::TypeNs(..) | DefPathData::CrateRoot | DefPathData::ImplTrait => {
Namespace::TypeNS
}
DefPathData::ValueNs(..)
| DefPathData::AnonConst
| DefPathData::ClosureExpr
| DefPathData::Ctor => Namespace::ValueNS,
DefPathData::MacroNs(..) => Namespace::MacroNS,
_ => Namespace::TypeNS,
}
}
impl TyCtxt<'t> {
/// Returns a string identifying this `DefId`. This string is
/// suitable for user output.
pub fn def_path_str(self, def_id: DefId) -> String {
self.def_path_str_with_substs(def_id, &[])
}
pub fn def_path_str_with_substs(self, def_id: DefId, substs: &'t [GenericArg<'t>]) -> String {
let ns = guess_def_namespace(self, def_id);
debug!("def_path_str: def_id={:?}, ns={:?}", def_id, ns);
let mut s = String::new();
let _ = FmtPrinter::new(self, &mut s, ns).print_def_path(def_id, substs);
s
}
}
impl<F: fmt::Write> fmt::Write for FmtPrinter<'_, '_, F> {
fn write_str(&mut self, s: &str) -> fmt::Result {
self.fmt.write_str(s)
}
}
impl<F: fmt::Write> Printer<'tcx> for FmtPrinter<'_, 'tcx, F> {
type Error = fmt::Error;
type Path = Self;
type Region = Self;
type Type = Self;
type DynExistential = Self;
type Const = Self;
fn tcx(&'a self) -> TyCtxt<'tcx> {
self.tcx
}
fn print_def_path(
mut self,
def_id: DefId,
substs: &'tcx [GenericArg<'tcx>],
) -> Result<Self::Path, Self::Error> {
define_scoped_cx!(self);
if substs.is_empty() {
match self.try_print_visible_def_path(def_id)? {
(cx, true) => return Ok(cx),
(cx, false) => self = cx,
}
}
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 = FORCE_IMPL_FILENAME_LINE.with(|f| f.get());
!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 = self.print_def_path(parent_def_id, &[])?;
// HACK(eddyb) copy of `path_append` to avoid
// constructing a `DisambiguatedDefPathData`.
if !self.empty_path {
write!(self, "::")?;
}
write!(self, "<impl at {}>", self.tcx.sess.source_map().span_to_string(span))?;
self.empty_path = false;
return Ok(self);
}
}
self.default_print_def_path(def_id, substs)
}
fn print_region(self, region: ty::Region<'_>) -> Result<Self::Region, Self::Error> {
self.pretty_print_region(region)
}
fn print_type(self, ty: Ty<'tcx>) -> Result<Self::Type, Self::Error> {
self.pretty_print_type(ty)
}
fn print_dyn_existential(
self,
predicates: &'tcx ty::List<ty::ExistentialPredicate<'tcx>>,
) -> Result<Self::DynExistential, Self::Error> {
self.pretty_print_dyn_existential(predicates)
}
fn print_const(self, ct: &'tcx ty::Const<'tcx>) -> Result<Self::Const, Self::Error> {
self.pretty_print_const(ct, true)
}
fn path_crate(mut self, cnum: CrateNum) -> Result<Self::Path, Self::Error> {
self.empty_path = true;
if cnum == LOCAL_CRATE {
if self.tcx.sess.rust_2018() {
// We add the `crate::` keyword on Rust 2018, only when desired.
if SHOULD_PREFIX_WITH_CRATE.with(|flag| flag.get()) {
write!(self, "{}", kw::Crate)?;
self.empty_path = false;
}
}
} else {
write!(self, "{}", self.tcx.crate_name(cnum))?;
self.empty_path = false;
}
Ok(self)
}
fn path_qualified(
mut self,
self_ty: Ty<'tcx>,
trait_ref: Option<ty::TraitRef<'tcx>>,
) -> Result<Self::Path, Self::Error> {
self = self.pretty_path_qualified(self_ty, trait_ref)?;
self.empty_path = false;
Ok(self)
}
fn path_append_impl(
mut self,
print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
_disambiguated_data: &DisambiguatedDefPathData,
self_ty: Ty<'tcx>,
trait_ref: Option<ty::TraitRef<'tcx>>,
) -> Result<Self::Path, Self::Error> {
self = self.pretty_path_append_impl(
|mut cx| {
cx = print_prefix(cx)?;
if !cx.empty_path {
write!(cx, "::")?;
}
Ok(cx)
},
self_ty,
trait_ref,
)?;
self.empty_path = false;
Ok(self)
}
fn path_append(
mut self,
print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
disambiguated_data: &DisambiguatedDefPathData,
) -> Result<Self::Path, Self::Error> {
self = print_prefix(self)?;
// Skip `::{{constructor}}` on tuple/unit structs.
if let DefPathData::Ctor = disambiguated_data.data {
return Ok(self);
}
// FIXME(eddyb) `name` should never be empty, but it
// currently is for `extern { ... }` "foreign modules".
let name = disambiguated_data.data.as_symbol().as_str();
if !name.is_empty() {
if !self.empty_path {
write!(self, "::")?;
}
if Ident::from_str(&name).is_raw_guess() {
write!(self, "r#")?;
}
write!(self, "{}", name)?;
// FIXME(eddyb) this will print e.g. `{{closure}}#3`, but it
// might be nicer to use something else, e.g. `{closure#3}`.
let dis = disambiguated_data.disambiguator;
let print_dis = disambiguated_data.data.get_opt_name().is_none()
|| dis != 0 && self.tcx.sess.verbose();
if print_dis {
write!(self, "#{}", dis)?;
}
self.empty_path = false;
}
Ok(self)
}
fn path_generic_args(
mut self,
print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
args: &[GenericArg<'tcx>],
) -> Result<Self::Path, Self::Error> {
self = print_prefix(self)?;
// Don't print `'_` if there's no unerased regions.
let print_regions = args.iter().any(|arg| match arg.unpack() {
GenericArgKind::Lifetime(r) => *r != ty::ReErased,
_ => false,
});
let args = args.iter().cloned().filter(|arg| match arg.unpack() {
GenericArgKind::Lifetime(_) => print_regions,
_ => true,
});
if args.clone().next().is_some() {
if self.in_value {
write!(self, "::")?;
}
self.generic_delimiters(|cx| cx.comma_sep(args))
} else {
Ok(self)
}
}
}
impl<F: fmt::Write> PrettyPrinter<'tcx> for FmtPrinter<'_, 'tcx, F> {
fn infer_ty_name(&self, id: ty::TyVid) -> Option<String> {
self.0.name_resolver.as_ref().and_then(|func| func(id))
}
fn print_value_path(
mut self,
def_id: DefId,
substs: &'tcx [GenericArg<'tcx>],
) -> Result<Self::Path, Self::Error> {
let was_in_value = std::mem::replace(&mut self.in_value, true);
self = self.print_def_path(def_id, substs)?;
self.in_value = was_in_value;
Ok(self)
}
fn in_binder<T>(self, value: &ty::Binder<T>) -> Result<Self, Self::Error>
where
T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<'tcx>,
{
self.pretty_in_binder(value)
}
fn typed_value(
mut self,
f: impl FnOnce(Self) -> Result<Self, Self::Error>,
t: impl FnOnce(Self) -> Result<Self, Self::Error>,
conversion: &str,
) -> Result<Self::Const, Self::Error> {
self.write_str("{")?;
self = f(self)?;
self.write_str(conversion)?;
let was_in_value = std::mem::replace(&mut self.in_value, false);
self = t(self)?;
self.in_value = was_in_value;
self.write_str("}")?;
Ok(self)
}
fn generic_delimiters(
mut self,
f: impl FnOnce(Self) -> Result<Self, Self::Error>,
) -> Result<Self, Self::Error> {
write!(self, "<")?;
let was_in_value = std::mem::replace(&mut self.in_value, false);
let mut inner = f(self)?;
inner.in_value = was_in_value;
write!(inner, ">")?;
Ok(inner)
}
fn region_should_not_be_omitted(&self, region: ty::Region<'_>) -> bool {
let highlight = self.region_highlight_mode;
if highlight.region_highlighted(region).is_some() {
return true;
}
if self.tcx.sess.verbose() {
return true;
}
let identify_regions = self.tcx.sess.opts.debugging_opts.identify_regions;
match *region {
ty::ReEarlyBound(ref data) => {
data.name != kw::Invalid && data.name != kw::UnderscoreLifetime
}
ty::ReLateBound(_, br)
| ty::ReFree(ty::FreeRegion { bound_region: br, .. })
| ty::RePlaceholder(ty::Placeholder { name: br, .. }) => {
if let ty::BrNamed(_, name) = br {
if name != kw::Invalid && name != kw::UnderscoreLifetime {
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 => false,
ty::ReStatic | ty::ReEmpty(_) => true,
}
}
fn pretty_print_const_pointer(
self,
p: Pointer,
ty: Ty<'tcx>,
print_ty: bool,
) -> Result<Self::Const, Self::Error> {
let print = |mut this: Self| {
define_scoped_cx!(this);
if this.print_alloc_ids {
p!(write("{:?}", p));
} else {
p!(write("&_"));
}
Ok(this)
};
if print_ty {
self.typed_value(print, |this| this.print_type(ty), ": ")
} else {
print(self)
}
}
}
// HACK(eddyb) limited to `FmtPrinter` because of `region_highlight_mode`.
impl<F: fmt::Write> FmtPrinter<'_, '_, F> {
pub fn pretty_print_region(mut self, region: ty::Region<'_>) -> Result<Self, fmt::Error> {
define_scoped_cx!(self);
// Watch out for region highlights.
let highlight = self.region_highlight_mode;
if let Some(n) = highlight.region_highlighted(region) {
p!(write("'{}", n));
return Ok(self);
}
if self.tcx.sess.verbose() {
p!(write("{:?}", region));
return Ok(self);
}
let identify_regions = self.tcx.sess.opts.debugging_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 {
ty::ReEarlyBound(ref data) => {
if data.name != kw::Invalid {
p!(write("{}", data.name));
return Ok(self);
}
}
ty::ReLateBound(_, br)
| ty::ReFree(ty::FreeRegion { bound_region: br, .. })
| ty::RePlaceholder(ty::Placeholder { name: br, .. }) => {
if let ty::BrNamed(_, name) = br {
if name != kw::Invalid && name != kw::UnderscoreLifetime {
p!(write("{}", name));
return Ok(self);
}
}
if let Some((region, counter)) = highlight.highlight_bound_region {
if br == region {
p!(write("'{}", counter));
return Ok(self);
}
}
}
ty::ReVar(region_vid) if identify_regions => {
p!(write("{:?}", region_vid));
return Ok(self);
}
ty::ReVar(_) => {}
ty::ReErased => {}
ty::ReStatic => {
p!(write("'static"));
return Ok(self);
}
ty::ReEmpty(ty::UniverseIndex::ROOT) => {
p!(write("'<empty>"));
return Ok(self);
}
ty::ReEmpty(ui) => {
p!(write("'<empty:{:?}>", ui));
return Ok(self);
}
}
p!(write("'_"));
Ok(self)
}
}
// HACK(eddyb) limited to `FmtPrinter` because of `binder_depth`,
// `region_index` and `used_region_names`.
impl<F: fmt::Write> FmtPrinter<'_, 'tcx, F> {
pub fn name_all_regions<T>(
mut self,
value: &ty::Binder<T>,
) -> Result<(Self, (T, BTreeMap<ty::BoundRegion, ty::Region<'tcx>>)), fmt::Error>
where
T: Print<'tcx, Self, Output = Self, Error = fmt::Error> + TypeFoldable<'tcx>,
{
fn name_by_region_index(index: usize) -> Symbol {
match index {
0 => Symbol::intern("'r"),
1 => Symbol::intern("'s"),
i => Symbol::intern(&format!("'t{}", i - 2)),
}
}
// 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_late_bound_region_info(value);
}
let mut empty = true;
let mut start_or_continue = |cx: &mut Self, start: &str, cont: &str| {
write!(
cx,
"{}",
if empty {
empty = false;
start
} else {
cont
}
)
};
define_scoped_cx!(self);
let mut region_index = self.region_index;
let new_value = self.tcx.replace_late_bound_regions(value, |br| {
let _ = start_or_continue(&mut self, "for<", ", ");
let br = match br {
ty::BrNamed(_, name) => {
let _ = write!(self, "{}", name);
br
}
ty::BrAnon(_) | ty::BrEnv => {
let name = loop {
let name = name_by_region_index(region_index);
region_index += 1;
if !self.used_region_names.contains(&name) {
break name;
}
};
let _ = write!(self, "{}", name);
ty::BrNamed(DefId::local(CRATE_DEF_INDEX), name)
}
};
self.tcx.mk_region(ty::ReLateBound(ty::INNERMOST, br))
});
start_or_continue(&mut self, "", "> ")?;
self.binder_depth += 1;
self.region_index = region_index;
Ok((self, new_value))
}
pub fn pretty_in_binder<T>(self, value: &ty::Binder<T>) -> Result<Self, fmt::Error>
where
T: Print<'tcx, Self, Output = Self, Error = fmt::Error> + TypeFoldable<'tcx>,
{
let old_region_index = self.region_index;
let (new, new_value) = self.name_all_regions(value)?;
let mut inner = new_value.0.print(new)?;
inner.region_index = old_region_index;
inner.binder_depth -= 1;
Ok(inner)
}
fn prepare_late_bound_region_info<T>(&mut self, value: &ty::Binder<T>)
where
T: TypeFoldable<'tcx>,
{
struct LateBoundRegionNameCollector<'a>(&'a mut FxHashSet<Symbol>);
impl<'tcx> ty::fold::TypeVisitor<'tcx> for LateBoundRegionNameCollector<'_> {
fn visit_region(&mut self, r: ty::Region<'tcx>) -> bool {
if let ty::ReLateBound(_, ty::BrNamed(_, name)) = *r {
self.0.insert(name);
}
r.super_visit_with(self)
}
}
self.used_region_names.clear();
let mut collector = LateBoundRegionNameCollector(&mut self.used_region_names);
value.visit_with(&mut collector);
self.region_index = 0;
}
}
impl<'tcx, T, P: PrettyPrinter<'tcx>> Print<'tcx, P> for ty::Binder<T>
where
T: Print<'tcx, P, Output = P, Error = P::Error> + TypeFoldable<'tcx>,
{
type Output = P;
type Error = P::Error;
fn print(&self, cx: P) -> Result<Self::Output, Self::Error> {
cx.in_binder(self)
}
}
impl<'tcx, T, U, P: PrettyPrinter<'tcx>> Print<'tcx, P> for ty::OutlivesPredicate<T, U>
where
T: Print<'tcx, P, Output = P, Error = P::Error>,
U: Print<'tcx, P, Output = P, Error = P::Error>,
{
type Output = P;
type Error = P::Error;
fn print(&self, mut cx: P) -> Result<Self::Output, Self::Error> {
define_scoped_cx!(cx);
p!(print(self.0), write(": "), print(self.1));
Ok(cx)
}
}
macro_rules! forward_display_to_print {
($($ty:ty),+) => {
$(impl fmt::Display for $ty {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
ty::tls::with(|tcx| {
tcx.lift(self)
.expect("could not lift for printing")
.print(FmtPrinter::new(tcx, f, Namespace::TypeNS))?;
Ok(())
})
}
})+
};
}
macro_rules! define_print_and_forward_display {
(($self:ident, $cx:ident): $($ty:ty $print:block)+) => {
$(impl<'tcx, P: PrettyPrinter<'tcx>> Print<'tcx, P> for $ty {
type Output = P;
type Error = fmt::Error;
fn print(&$self, $cx: P) -> Result<Self::Output, Self::Error> {
#[allow(unused_mut)]
let mut $cx = $cx;
define_scoped_cx!($cx);
let _: () = $print;
#[allow(unreachable_code)]
Ok($cx)
}
})+
forward_display_to_print!($($ty),+);
};
}
// HACK(eddyb) this is separate because `ty::RegionKind` doesn't need lifting.
impl fmt::Display for ty::RegionKind {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
ty::tls::with(|tcx| {
self.print(FmtPrinter::new(tcx, f, Namespace::TypeNS))?;
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, Lift)]
pub struct TraitRefPrintOnlyTraitPath<'tcx>(ty::TraitRef<'tcx>);
impl fmt::Debug for TraitRefPrintOnlyTraitPath<'tcx> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Display::fmt(self, f)
}
}
impl ty::TraitRef<'tcx> {
pub fn print_only_trait_path(self) -> TraitRefPrintOnlyTraitPath<'tcx> {
TraitRefPrintOnlyTraitPath(self)
}
}
impl ty::Binder<ty::TraitRef<'tcx>> {
pub fn print_only_trait_path(self) -> ty::Binder<TraitRefPrintOnlyTraitPath<'tcx>> {
self.map_bound(|tr| tr.print_only_trait_path())
}
}
forward_display_to_print! {
Ty<'tcx>,
&'tcx ty::List<ty::ExistentialPredicate<'tcx>>,
&'tcx ty::Const<'tcx>,
// HACK(eddyb) these are exhaustive instead of generic,
// because `for<'tcx>` isn't possible yet.
ty::Binder<&'tcx ty::List<ty::ExistentialPredicate<'tcx>>>,
ty::Binder<ty::TraitRef<'tcx>>,
ty::Binder<TraitRefPrintOnlyTraitPath<'tcx>>,
ty::Binder<ty::FnSig<'tcx>>,
ty::Binder<ty::TraitPredicate<'tcx>>,
ty::Binder<ty::SubtypePredicate<'tcx>>,
ty::Binder<ty::ProjectionPredicate<'tcx>>,
ty::Binder<ty::OutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>>>,
ty::Binder<ty::OutlivesPredicate<ty::Region<'tcx>, ty::Region<'tcx>>>,
ty::OutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>>,
ty::OutlivesPredicate<ty::Region<'tcx>, ty::Region<'tcx>>
}
define_print_and_forward_display! {
(self, cx):
&'tcx ty::List<Ty<'tcx>> {
p!(write("{{"), comma_sep(self.iter()), write("}}"))
}
ty::TypeAndMut<'tcx> {
p!(write("{}", self.mutbl.prefix_str()), print(self.ty))
}
ty::ExistentialTraitRef<'tcx> {
// Use a type that can't appear in defaults of type parameters.
let dummy_self = cx.tcx().mk_ty_infer(ty::FreshTy(0));
let trait_ref = self.with_self_ty(cx.tcx(), dummy_self);
p!(print(trait_ref.print_only_trait_path()))
}
ty::ExistentialProjection<'tcx> {
let name = cx.tcx().associated_item(self.item_def_id).ident;
p!(write("{} = ", name), print(self.ty))
}
ty::ExistentialPredicate<'tcx> {
match *self {
ty::ExistentialPredicate::Trait(x) => p!(print(x)),
ty::ExistentialPredicate::Projection(x) => p!(print(x)),
ty::ExistentialPredicate::AutoTrait(def_id) => {
p!(print_def_path(def_id, &[]));
}
}
}
ty::FnSig<'tcx> {
p!(write("{}", self.unsafety.prefix_str()));
if self.abi != Abi::Rust {
p!(write("extern {} ", self.abi));
}
p!(write("fn"), pretty_fn_sig(self.inputs(), self.c_variadic, self.output()));
}
ty::InferTy {
if cx.tcx().sess.verbose() {
p!(write("{:?}", self));
return Ok(cx);
}
match *self {
ty::TyVar(_) => p!(write("_")),
ty::IntVar(_) => p!(write("{}", "{integer}")),
ty::FloatVar(_) => p!(write("{}", "{float}")),
ty::FreshTy(v) => p!(write("FreshTy({})", v)),
ty::FreshIntTy(v) => p!(write("FreshIntTy({})", v)),
ty::FreshFloatTy(v) => p!(write("FreshFloatTy({})", v))
}
}
ty::TraitRef<'tcx> {
p!(write("<{} as {}>", self.self_ty(), self.print_only_trait_path()))
}
TraitRefPrintOnlyTraitPath<'tcx> {
p!(print_def_path(self.0.def_id, self.0.substs));
}
ty::ParamTy {
p!(write("{}", self.name))
}
ty::ParamConst {
p!(write("{}", self.name))
}
ty::SubtypePredicate<'tcx> {
p!(print(self.a), write(" <: "), print(self.b))
}
ty::TraitPredicate<'tcx> {
p!(print(self.trait_ref.self_ty()), write(": "),
print(self.trait_ref.print_only_trait_path()))
}
ty::ProjectionPredicate<'tcx> {
p!(print(self.projection_ty), write(" == "), print(self.ty))
}
ty::ProjectionTy<'tcx> {
p!(print_def_path(self.item_def_id, self.substs));
}
ty::ClosureKind {
match *self {
ty::ClosureKind::Fn => p!(write("Fn")),
ty::ClosureKind::FnMut => p!(write("FnMut")),
ty::ClosureKind::FnOnce => p!(write("FnOnce")),
}
}
ty::Predicate<'tcx> {
match self.kind() {
&ty::PredicateKind::Trait(ref data, constness) => {
if let hir::Constness::Const = constness {
p!(write("const "));
}
p!(print(data))
}
ty::PredicateKind::Subtype(predicate) => p!(print(predicate)),
ty::PredicateKind::RegionOutlives(predicate) => p!(print(predicate)),
ty::PredicateKind::TypeOutlives(predicate) => p!(print(predicate)),
ty::PredicateKind::Projection(predicate) => p!(print(predicate)),
ty::PredicateKind::WellFormed(arg) => p!(print(arg), write(" well-formed")),
&ty::PredicateKind::ObjectSafe(trait_def_id) => {
p!(write("the trait `"),
print_def_path(trait_def_id, &[]),
write("` is object-safe"))
}
&ty::PredicateKind::ClosureKind(closure_def_id, _closure_substs, kind) => {
p!(write("the closure `"),
print_value_path(closure_def_id, &[]),
write("` implements the trait `{}`", kind))
}
&ty::PredicateKind::ConstEvaluatable(def_id, substs) => {
p!(write("the constant `"),
print_value_path(def_id, substs),
write("` can be evaluated"))
}
ty::PredicateKind::ConstEquate(c1, c2) => {
p!(write("the constant `"),
print(c1),
write("` equals `"),
print(c2),
write("`"))
}
}
}
GenericArg<'tcx> {
match self.unpack() {
GenericArgKind::Lifetime(lt) => p!(print(lt)),
GenericArgKind::Type(ty) => p!(print(ty)),
GenericArgKind::Const(ct) => p!(print(ct)),
}
}
}