Auto merge of #94131 - Mark-Simulacrum:fmt-string, r=oli-obk

Always format to internal String in FmtPrinter

This avoids monomorphizing for different parameters, decreasing generic code
instantiated downstream from rustc_middle -- locally seeing 7% unoptimized LLVM IR
line wins on rustc_borrowck, for example.

We likely can't/shouldn't get rid of the Result-ness on most functions, though some
further cleanup avoiding fmt::Error where we now know it won't occur may be possible,
though somewhat painful -- fmt::Write is a pretty annoying API to work with in practice
when you're trying to use it infallibly.
This commit is contained in:
bors 2022-02-24 17:18:07 +00:00
commit 4b043faba3
10 changed files with 84 additions and 80 deletions

View File

@ -488,8 +488,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
/// Return the name of the provided `Ty` (that must be a reference) with a synthesized lifetime
/// name where required.
pub(super) fn get_name_for_ty(&self, ty: Ty<'tcx>, counter: usize) -> String {
let mut s = String::new();
let mut printer = ty::print::FmtPrinter::new(self.infcx.tcx, &mut s, Namespace::TypeNS);
let mut printer = ty::print::FmtPrinter::new(self.infcx.tcx, Namespace::TypeNS);
// We need to add synthesized lifetimes where appropriate. We do
// this by hooking into the pretty printer and telling it to label the
@ -504,15 +503,13 @@ pub(super) fn get_name_for_ty(&self, ty: Ty<'tcx>, counter: usize) -> String {
}
}
let _ = ty.print(printer);
s
ty.print(printer).unwrap().into_buffer()
}
/// Returns the name of the provided `Ty` (that must be a reference)'s region with a
/// synthesized lifetime name where required.
pub(super) fn get_region_name_for_ty(&self, ty: Ty<'tcx>, counter: usize) -> String {
let mut s = String::new();
let mut printer = ty::print::FmtPrinter::new(self.infcx.tcx, &mut s, Namespace::TypeNS);
let mut printer = ty::print::FmtPrinter::new(self.infcx.tcx, Namespace::TypeNS);
let region = if let ty::Ref(region, ..) = ty.kind() {
match **region {
@ -527,8 +524,7 @@ pub(super) fn get_region_name_for_ty(&self, ty: Ty<'tcx>, counter: usize) -> Str
bug!("ty for annotation of borrow region is not a reference");
};
let _ = region.print(printer);
s
region.print(printer).unwrap().into_buffer()
}
}

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@ -109,11 +109,11 @@ pub struct ImmTy<'tcx, Tag: Provenance = AllocId> {
impl<Tag: Provenance> std::fmt::Display for ImmTy<'_, Tag> {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
/// Helper function for printing a scalar to a FmtPrinter
fn p<'a, 'tcx, F: std::fmt::Write, Tag: Provenance>(
cx: FmtPrinter<'a, 'tcx, F>,
fn p<'a, 'tcx, Tag: Provenance>(
cx: FmtPrinter<'a, 'tcx>,
s: ScalarMaybeUninit<Tag>,
ty: Ty<'tcx>,
) -> Result<FmtPrinter<'a, 'tcx, F>, std::fmt::Error> {
) -> Result<FmtPrinter<'a, 'tcx>, std::fmt::Error> {
match s {
ScalarMaybeUninit::Scalar(Scalar::Int(int)) => {
cx.pretty_print_const_scalar_int(int, ty, true)
@ -138,8 +138,8 @@ fn p<'a, 'tcx, F: std::fmt::Write, Tag: Provenance>(
match self.imm {
Immediate::Scalar(s) => {
if let Some(ty) = tcx.lift(self.layout.ty) {
let cx = FmtPrinter::new(tcx, f, Namespace::ValueNS);
p(cx, s, ty)?;
let cx = FmtPrinter::new(tcx, Namespace::ValueNS);
f.write_str(&p(cx, s, ty)?.into_buffer())?;
return Ok(());
}
write!(f, "{:x}: {}", s, self.layout.ty)

View File

@ -988,8 +988,7 @@ fn cmp_fn_sig(
) -> (DiagnosticStyledString, DiagnosticStyledString) {
let get_lifetimes = |sig| {
use rustc_hir::def::Namespace;
let mut s = String::new();
let (_, sig, reg) = ty::print::FmtPrinter::new(self.tcx, &mut s, Namespace::TypeNS)
let (_, sig, reg) = ty::print::FmtPrinter::new(self.tcx, Namespace::TypeNS)
.name_all_regions(sig)
.unwrap();
let lts: Vec<String> = reg.into_iter().map(|(_, kind)| kind.to_string()).collect();

View File

@ -397,14 +397,13 @@ pub fn extract_inference_diagnostics_data(
}
}
let mut s = String::new();
let mut printer = ty::print::FmtPrinter::new(self.tcx, &mut s, Namespace::TypeNS);
let mut printer = ty::print::FmtPrinter::new(self.tcx, Namespace::TypeNS);
if let Some(highlight) = highlight {
printer.region_highlight_mode = highlight;
}
let _ = ty.print(printer);
let name = ty.print(printer).unwrap().into_buffer();
InferenceDiagnosticsData {
name: s,
name,
span: None,
kind: UnderspecifiedArgKind::Type { prefix: ty.prefix_string(self.tcx) },
parent: None,
@ -433,15 +432,13 @@ pub fn extract_inference_diagnostics_data(
}
debug_assert!(!origin.span.is_dummy());
let mut s = String::new();
let mut printer =
ty::print::FmtPrinter::new(self.tcx, &mut s, Namespace::ValueNS);
let mut printer = ty::print::FmtPrinter::new(self.tcx, Namespace::ValueNS);
if let Some(highlight) = highlight {
printer.region_highlight_mode = highlight;
}
let _ = ct.print(printer);
let name = ct.print(printer).unwrap().into_buffer();
InferenceDiagnosticsData {
name: s,
name,
span: Some(origin.span),
kind: UnderspecifiedArgKind::Const { is_parameter: false },
parent: None,
@ -497,8 +494,7 @@ pub fn emit_inference_failure_err(
let mut local_visitor = FindHirNodeVisitor::new(&self, arg, span);
let ty_to_string = |ty: Ty<'tcx>| -> String {
let mut s = String::new();
let mut printer = ty::print::FmtPrinter::new(self.tcx, &mut s, Namespace::TypeNS);
let mut printer = ty::print::FmtPrinter::new(self.tcx, Namespace::TypeNS);
let ty_getter = move |ty_vid| {
if let TypeVariableOriginKind::TypeParameterDefinition(name, _) =
self.inner.borrow_mut().type_variables().var_origin(ty_vid).kind
@ -525,14 +521,13 @@ pub fn emit_inference_failure_err(
};
printer.const_infer_name_resolver = Some(Box::new(const_getter));
let _ = if let ty::FnDef(..) = ty.kind() {
if let ty::FnDef(..) = ty.kind() {
// We don't want the regular output for `fn`s because it includes its path in
// invalid pseudo-syntax, we want the `fn`-pointer output instead.
ty.fn_sig(self.tcx).print(printer)
ty.fn_sig(self.tcx).print(printer).unwrap().into_buffer()
} else {
ty.print(printer)
};
s
ty.print(printer).unwrap().into_buffer()
}
};
if let Some(body_id) = body_id {

View File

@ -335,18 +335,19 @@ fn map<U>(self, f: impl FnOnce(T) -> U) -> Highlighted<'tcx, U> {
impl<'tcx, T> fmt::Display for Highlighted<'tcx, T>
where
T: for<'a, 'b, 'c> Print<
T: for<'a> Print<
'tcx,
FmtPrinter<'a, 'tcx, &'b mut fmt::Formatter<'c>>,
FmtPrinter<'a, 'tcx>,
Error = fmt::Error,
Output = FmtPrinter<'a, 'tcx>,
>,
{
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let mut printer = ty::print::FmtPrinter::new(self.tcx, f, Namespace::TypeNS);
let mut printer = ty::print::FmtPrinter::new(self.tcx, Namespace::TypeNS);
printer.region_highlight_mode = self.highlight;
self.value.print(printer)?;
Ok(())
let s = self.value.print(printer)?.into_buffer();
f.write_str(&s)
}
}

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@ -2421,11 +2421,11 @@ fn fmt(&self, fmt: &mut Formatter<'_>) -> fmt::Result {
AggregateKind::Adt(adt_did, variant, substs, _user_ty, _) => {
ty::tls::with(|tcx| {
let mut name = String::new();
let variant_def = &tcx.adt_def(adt_did).variants[variant];
let substs = tcx.lift(substs).expect("could not lift for printing");
FmtPrinter::new(tcx, &mut name, Namespace::ValueNS)
.print_def_path(variant_def.def_id, substs)?;
let name = FmtPrinter::new(tcx, Namespace::ValueNS)
.print_def_path(variant_def.def_id, substs)?
.into_buffer();
match variant_def.ctor_kind {
CtorKind::Const => fmt.write_str(&name),
@ -2847,9 +2847,10 @@ fn pretty_print_const<'tcx>(
use crate::ty::print::PrettyPrinter;
ty::tls::with(|tcx| {
let literal = tcx.lift(c).unwrap();
let mut cx = FmtPrinter::new(tcx, fmt, Namespace::ValueNS);
let mut cx = FmtPrinter::new(tcx, Namespace::ValueNS);
cx.print_alloc_ids = true;
cx.pretty_print_const(literal, print_types)?;
let cx = cx.pretty_print_const(literal, print_types)?;
fmt.write_str(&cx.into_buffer())?;
Ok(())
})
}
@ -2864,9 +2865,10 @@ fn pretty_print_const_value<'tcx>(
ty::tls::with(|tcx| {
let val = tcx.lift(val).unwrap();
let ty = tcx.lift(ty).unwrap();
let mut cx = FmtPrinter::new(tcx, fmt, Namespace::ValueNS);
let mut cx = FmtPrinter::new(tcx, Namespace::ValueNS);
cx.print_alloc_ids = true;
cx.pretty_print_const_value(val, ty, print_types)?;
let cx = cx.pretty_print_const_value(val, ty, print_types)?;
fmt.write_str(&cx.into_buffer())?;
Ok(())
})
}

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@ -983,10 +983,9 @@ fn constrain_associated_type_structured_suggestion(
}
fn format_generic_args(self, args: &[ty::GenericArg<'tcx>]) -> String {
let mut item_args = String::new();
FmtPrinter::new(self, &mut item_args, hir::def::Namespace::TypeNS)
FmtPrinter::new(self, hir::def::Namespace::TypeNS)
.path_generic_args(Ok, args)
.expect("could not write to `String`.");
item_args
.expect("could not write to `String`.")
.into_buffer()
}
}

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@ -279,9 +279,10 @@ impl<'tcx> fmt::Display for Instance<'tcx> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
ty::tls::with(|tcx| {
let substs = tcx.lift(self.substs).expect("could not lift for printing");
FmtPrinter::new(tcx, &mut *f, Namespace::ValueNS)
.print_def_path(self.def_id(), substs)?;
Ok(())
let s = FmtPrinter::new(tcx, Namespace::ValueNS)
.print_def_path(self.def_id(), substs)?
.into_buffer();
f.write_str(&s)
})?;
match self.def {

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@ -1543,11 +1543,11 @@ fn pretty_print_const_value(
}
// 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 FmtPrinter<'a, 'tcx>(Box<FmtPrinterData<'a, 'tcx>>);
pub struct FmtPrinterData<'a, 'tcx, F> {
pub struct FmtPrinterData<'a, 'tcx> {
tcx: TyCtxt<'tcx>,
fmt: F,
fmt: String,
empty_path: bool,
in_value: bool,
@ -1564,24 +1564,26 @@ pub struct FmtPrinterData<'a, 'tcx, F> {
pub const_infer_name_resolver: Option<Box<dyn Fn(ty::ConstVid<'tcx>) -> Option<String> + 'a>>,
}
impl<'a, 'tcx, F> Deref for FmtPrinter<'a, 'tcx, F> {
type Target = FmtPrinterData<'a, 'tcx, F>;
impl<'a, 'tcx> Deref for FmtPrinter<'a, 'tcx> {
type Target = FmtPrinterData<'a, 'tcx>;
fn deref(&self) -> &Self::Target {
&self.0
}
}
impl<F> DerefMut for FmtPrinter<'_, '_, F> {
impl DerefMut for FmtPrinter<'_, '_> {
fn deref_mut(&mut self) -> &mut Self::Target {
&mut self.0
}
}
impl<'a, 'tcx, F> FmtPrinter<'a, 'tcx, F> {
pub fn new(tcx: TyCtxt<'tcx>, fmt: F, ns: Namespace) -> Self {
impl<'a, 'tcx> FmtPrinter<'a, 'tcx> {
pub fn new(tcx: TyCtxt<'tcx>, ns: Namespace) -> Self {
FmtPrinter(Box::new(FmtPrinterData {
tcx,
fmt,
// 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,
@ -1594,6 +1596,10 @@ pub fn new(tcx: TyCtxt<'tcx>, fmt: F, ns: Namespace) -> Self {
const_infer_name_resolver: None,
}))
}
pub fn into_buffer(self) -> String {
self.0.fmt
}
}
// HACK(eddyb) get rid of `def_path_str` and/or pass `Namespace` explicitly always
@ -1625,19 +1631,18 @@ pub fn def_path_str(self, def_id: DefId) -> String {
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
FmtPrinter::new(self, ns).print_def_path(def_id, substs).unwrap().into_buffer()
}
}
impl<F: fmt::Write> fmt::Write for FmtPrinter<'_, '_, F> {
impl fmt::Write for FmtPrinter<'_, '_> {
fn write_str(&mut self, s: &str) -> fmt::Result {
self.fmt.write_str(s)
self.fmt.push_str(s);
Ok(())
}
}
impl<'tcx, F: fmt::Write> Printer<'tcx> for FmtPrinter<'_, 'tcx, F> {
impl<'tcx> Printer<'tcx> for FmtPrinter<'_, 'tcx> {
type Error = fmt::Error;
type Path = Self;
@ -1845,7 +1850,7 @@ fn path_generic_args(
}
}
impl<'tcx, F: fmt::Write> PrettyPrinter<'tcx> for FmtPrinter<'_, 'tcx, F> {
impl<'tcx> PrettyPrinter<'tcx> for FmtPrinter<'_, 'tcx> {
fn ty_infer_name(&self, id: ty::TyVid) -> Option<String> {
self.0.ty_infer_name_resolver.as_ref().and_then(|func| func(id))
}
@ -1981,7 +1986,7 @@ fn pretty_print_const_pointer<Tag: Provenance>(
}
// HACK(eddyb) limited to `FmtPrinter` because of `region_highlight_mode`.
impl<F: fmt::Write> FmtPrinter<'_, '_, F> {
impl FmtPrinter<'_, '_> {
pub fn pretty_print_region(mut self, region: ty::Region<'_>) -> Result<Self, fmt::Error> {
define_scoped_cx!(self);
@ -2115,7 +2120,7 @@ fn fold_region(&mut self, r: ty::Region<'tcx>) -> ty::Region<'tcx> {
// HACK(eddyb) limited to `FmtPrinter` because of `binder_depth`,
// `region_index` and `used_region_names`.
impl<'tcx, F: fmt::Write> FmtPrinter<'_, 'tcx, F> {
impl<'tcx> FmtPrinter<'_, 'tcx> {
pub fn name_all_regions<T>(
mut self,
value: &ty::Binder<'tcx, T>,
@ -2367,9 +2372,10 @@ macro_rules! forward_display_to_print {
$(#[allow(unused_lifetimes)] impl<'tcx> fmt::Display for $ty {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
ty::tls::with(|tcx| {
tcx.lift(*self)
let cx = tcx.lift(*self)
.expect("could not lift for printing")
.print(FmtPrinter::new(tcx, f, Namespace::TypeNS))?;
.print(FmtPrinter::new(tcx, Namespace::TypeNS))?;
f.write_str(&cx.into_buffer())?;
Ok(())
})
}
@ -2400,8 +2406,7 @@ fn print(&$self, $cx: P) -> Result<Self::Output, Self::Error> {
impl<'tcx> fmt::Display for ty::Region<'tcx> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
ty::tls::with(|tcx| {
self.print(FmtPrinter::new(tcx, f, Namespace::TypeNS))?;
Ok(())
f.write_str(&self.print(FmtPrinter::new(tcx, Namespace::TypeNS))?.into_buffer())
})
}
}

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@ -22,10 +22,13 @@
impl fmt::Debug for ty::TraitDef {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
ty::tls::with(|tcx| {
with_no_trimmed_paths!(
FmtPrinter::new(tcx, f, Namespace::TypeNS).print_def_path(self.def_id, &[])?
);
Ok(())
with_no_trimmed_paths!({
f.write_str(
&FmtPrinter::new(tcx, Namespace::TypeNS)
.print_def_path(self.def_id, &[])?
.into_buffer(),
)
})
})
}
}
@ -33,10 +36,13 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
impl fmt::Debug for ty::AdtDef {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
ty::tls::with(|tcx| {
with_no_trimmed_paths!(
FmtPrinter::new(tcx, f, Namespace::TypeNS).print_def_path(self.did, &[])?
);
Ok(())
with_no_trimmed_paths!({
f.write_str(
&FmtPrinter::new(tcx, Namespace::TypeNS)
.print_def_path(self.did, &[])?
.into_buffer(),
)
})
})
}
}