Merge `diagnostic_builder.rs` into `diagnostic.rs`.

Because:
- `diagnostic_builder.rs` is small (282 lines),
- `Diagnostic` and `DiagnosticBuilder` are closely related types, and
- there's already an `impl DiagnosticBuilder` block in `diagnostic.rs`.

At the same time, reorder a few of things already in `diagnostic.rs`,
e.g. move `struct Diagnostic` just before `impl Diagnostic`.

This commit only moves code around. There are no functional changes.
This commit is contained in:
Nicholas Nethercote 2024-02-21 09:37:30 +11:00
parent bb594538fc
commit 8f20a54c6d
5 changed files with 355 additions and 372 deletions

View File

@ -1,19 +1,22 @@
use crate::snippet::Style;
use crate::{
CodeSuggestion, DiagnosticBuilder, DiagnosticMessage, EmissionGuarantee, ErrCode, Level,
MultiSpan, SubdiagnosticMessage, Substitution, SubstitutionPart, SuggestionStyle,
CodeSuggestion, DiagCtxt, DiagnosticMessage, ErrCode, ErrorGuaranteed, ExplicitBug, Level,
MultiSpan, StashKey, SubdiagnosticMessage, Substitution, SubstitutionPart, SuggestionStyle,
};
use rustc_data_structures::fx::FxIndexMap;
use rustc_error_messages::fluent_value_from_str_list_sep_by_and;
use rustc_error_messages::FluentValue;
use rustc_lint_defs::{Applicability, LintExpectationId};
use rustc_span::source_map::Spanned;
use rustc_span::symbol::Symbol;
use rustc_span::{Span, DUMMY_SP};
use std::borrow::Cow;
use std::fmt::{self, Debug};
use std::hash::{Hash, Hasher};
use std::marker::PhantomData;
use std::ops::{Deref, DerefMut};
use std::panic::Location;
use std::panic;
use std::thread::panicking;
/// Error type for `Diagnostic`'s `suggestions` field, indicating that
/// `.disable_suggestions()` was called on the `Diagnostic`.
@ -40,6 +43,86 @@ pub enum DiagnosticArgValue {
StrListSepByAnd(Vec<Cow<'static, str>>),
}
/// Trait for types that `DiagnosticBuilder::emit` can return as a "guarantee"
/// (or "proof") token that the emission happened.
pub trait EmissionGuarantee: Sized {
/// This exists so that bugs and fatal errors can both result in `!` (an
/// abort) when emitted, but have different aborting behaviour.
type EmitResult = Self;
/// Implementation of `DiagnosticBuilder::emit`, fully controlled by each
/// `impl` of `EmissionGuarantee`, to make it impossible to create a value
/// of `Self::EmitResult` without actually performing the emission.
#[track_caller]
fn emit_producing_guarantee(db: DiagnosticBuilder<'_, Self>) -> Self::EmitResult;
}
impl EmissionGuarantee for ErrorGuaranteed {
fn emit_producing_guarantee(db: DiagnosticBuilder<'_, Self>) -> Self::EmitResult {
db.emit_producing_error_guaranteed()
}
}
impl EmissionGuarantee for () {
fn emit_producing_guarantee(db: DiagnosticBuilder<'_, Self>) -> Self::EmitResult {
db.emit_producing_nothing();
}
}
/// Marker type which enables implementation of `create_bug` and `emit_bug` functions for
/// bug diagnostics.
#[derive(Copy, Clone)]
pub struct BugAbort;
impl EmissionGuarantee for BugAbort {
type EmitResult = !;
fn emit_producing_guarantee(db: DiagnosticBuilder<'_, Self>) -> Self::EmitResult {
db.emit_producing_nothing();
panic::panic_any(ExplicitBug);
}
}
/// Marker type which enables implementation of `create_fatal` and `emit_fatal` functions for
/// fatal diagnostics.
#[derive(Copy, Clone)]
pub struct FatalAbort;
impl EmissionGuarantee for FatalAbort {
type EmitResult = !;
fn emit_producing_guarantee(db: DiagnosticBuilder<'_, Self>) -> Self::EmitResult {
db.emit_producing_nothing();
crate::FatalError.raise()
}
}
impl EmissionGuarantee for rustc_span::fatal_error::FatalError {
fn emit_producing_guarantee(db: DiagnosticBuilder<'_, Self>) -> Self::EmitResult {
db.emit_producing_nothing();
rustc_span::fatal_error::FatalError
}
}
/// Trait implemented by error types. This is rarely implemented manually. Instead, use
/// `#[derive(Diagnostic)]` -- see [rustc_macros::Diagnostic].
#[rustc_diagnostic_item = "IntoDiagnostic"]
pub trait IntoDiagnostic<'a, G: EmissionGuarantee = ErrorGuaranteed> {
/// Write out as a diagnostic out of `DiagCtxt`.
#[must_use]
fn into_diagnostic(self, dcx: &'a DiagCtxt, level: Level) -> DiagnosticBuilder<'a, G>;
}
impl<'a, T, G> IntoDiagnostic<'a, G> for Spanned<T>
where
T: IntoDiagnostic<'a, G>,
G: EmissionGuarantee,
{
fn into_diagnostic(self, dcx: &'a DiagCtxt, level: Level) -> DiagnosticBuilder<'a, G> {
self.node.into_diagnostic(dcx, level).with_span(self.span)
}
}
/// Converts a value of a type into a `DiagnosticArg` (typically a field of an `IntoDiagnostic`
/// struct). Implemented as a custom trait rather than `From` so that it is implemented on the type
/// being converted rather than on `DiagnosticArgValue`, which enables types from other `rustc_*`
@ -98,36 +181,6 @@ pub trait DecorateLint<'a, G: EmissionGuarantee> {
fn msg(&self) -> DiagnosticMessage;
}
/// The main part of a diagnostic. Note that `DiagnosticBuilder`, which wraps
/// this type, is used for most operations, and should be used instead whenever
/// possible. This type should only be used when `DiagnosticBuilder`'s lifetime
/// causes difficulties, e.g. when storing diagnostics within `DiagCtxt`.
#[must_use]
#[derive(Clone, Debug, Encodable, Decodable)]
pub struct Diagnostic {
// NOTE(eddyb) this is private to disallow arbitrary after-the-fact changes,
// outside of what methods in this crate themselves allow.
pub(crate) level: Level,
pub messages: Vec<(DiagnosticMessage, Style)>,
pub code: Option<ErrCode>,
pub span: MultiSpan,
pub children: Vec<SubDiagnostic>,
pub suggestions: Result<Vec<CodeSuggestion>, SuggestionsDisabled>,
args: FxIndexMap<DiagnosticArgName, DiagnosticArgValue>,
/// This is not used for highlighting or rendering any error message. Rather, it can be used
/// as a sort key to sort a buffer of diagnostics. By default, it is the primary span of
/// `span` if there is one. Otherwise, it is `DUMMY_SP`.
pub sort_span: Span,
pub is_lint: Option<IsLint>,
/// With `-Ztrack_diagnostics` enabled,
/// we print where in rustc this error was emitted.
pub(crate) emitted_at: DiagnosticLocation,
}
#[derive(Clone, Debug, Encodable, Decodable)]
pub struct DiagnosticLocation {
file: Cow<'static, str>,
@ -138,7 +191,7 @@ pub struct DiagnosticLocation {
impl DiagnosticLocation {
#[track_caller]
fn caller() -> Self {
let loc = Location::caller();
let loc = panic::Location::caller();
DiagnosticLocation { file: loc.file().into(), line: loc.line(), col: loc.column() }
}
}
@ -157,15 +210,6 @@ pub struct IsLint {
has_future_breakage: bool,
}
/// A "sub"-diagnostic attached to a parent diagnostic.
/// For example, a note attached to an error.
#[derive(Clone, Debug, PartialEq, Hash, Encodable, Decodable)]
pub struct SubDiagnostic {
pub level: Level,
pub messages: Vec<(DiagnosticMessage, Style)>,
pub span: MultiSpan,
}
#[derive(Debug, PartialEq, Eq)]
pub struct DiagnosticStyledString(pub Vec<StringPart>);
@ -215,6 +259,36 @@ impl StringPart {
}
}
/// The main part of a diagnostic. Note that `DiagnosticBuilder`, which wraps
/// this type, is used for most operations, and should be used instead whenever
/// possible. This type should only be used when `DiagnosticBuilder`'s lifetime
/// causes difficulties, e.g. when storing diagnostics within `DiagCtxt`.
#[must_use]
#[derive(Clone, Debug, Encodable, Decodable)]
pub struct Diagnostic {
// NOTE(eddyb) this is private to disallow arbitrary after-the-fact changes,
// outside of what methods in this crate themselves allow.
pub(crate) level: Level,
pub messages: Vec<(DiagnosticMessage, Style)>,
pub code: Option<ErrCode>,
pub span: MultiSpan,
pub children: Vec<SubDiagnostic>,
pub suggestions: Result<Vec<CodeSuggestion>, SuggestionsDisabled>,
args: FxIndexMap<DiagnosticArgName, DiagnosticArgValue>,
/// This is not used for highlighting or rendering any error message. Rather, it can be used
/// as a sort key to sort a buffer of diagnostics. By default, it is the primary span of
/// `span` if there is one. Otherwise, it is `DUMMY_SP`.
pub sort_span: Span,
pub is_lint: Option<IsLint>,
/// With `-Ztrack_diagnostics` enabled,
/// we print where in rustc this error was emitted.
pub(crate) emitted_at: DiagnosticLocation,
}
impl Diagnostic {
#[track_caller]
pub fn new<M: Into<DiagnosticMessage>>(level: Level, message: M) -> Self {
@ -336,6 +410,120 @@ impl Diagnostic {
pub fn replace_args(&mut self, args: FxIndexMap<DiagnosticArgName, DiagnosticArgValue>) {
self.args = args;
}
/// Fields used for Hash, and PartialEq trait.
fn keys(
&self,
) -> (
&Level,
&[(DiagnosticMessage, Style)],
&Option<ErrCode>,
&MultiSpan,
&[SubDiagnostic],
&Result<Vec<CodeSuggestion>, SuggestionsDisabled>,
Vec<(&DiagnosticArgName, &DiagnosticArgValue)>,
&Option<IsLint>,
) {
(
&self.level,
&self.messages,
&self.code,
&self.span,
&self.children,
&self.suggestions,
self.args().collect(),
// omit self.sort_span
&self.is_lint,
// omit self.emitted_at
)
}
}
impl Hash for Diagnostic {
fn hash<H>(&self, state: &mut H)
where
H: Hasher,
{
self.keys().hash(state);
}
}
impl PartialEq for Diagnostic {
fn eq(&self, other: &Self) -> bool {
self.keys() == other.keys()
}
}
/// A "sub"-diagnostic attached to a parent diagnostic.
/// For example, a note attached to an error.
#[derive(Clone, Debug, PartialEq, Hash, Encodable, Decodable)]
pub struct SubDiagnostic {
pub level: Level,
pub messages: Vec<(DiagnosticMessage, Style)>,
pub span: MultiSpan,
}
/// Used for emitting structured error messages and other diagnostic information.
/// Wraps a `Diagnostic`, adding some useful things.
/// - The `dcx` field, allowing it to (a) emit itself, and (b) do a drop check
/// that it has been emitted or cancelled.
/// - The `EmissionGuarantee`, which determines the type returned from `emit`.
///
/// Each constructed `DiagnosticBuilder` must be consumed by a function such as
/// `emit`, `cancel`, `delay_as_bug`, or `into_diagnostic`. A panic occurrs if a
/// `DiagnosticBuilder` is dropped without being consumed by one of these
/// functions.
///
/// If there is some state in a downstream crate you would like to
/// access in the methods of `DiagnosticBuilder` here, consider
/// extending `DiagCtxtFlags`.
#[must_use]
pub struct DiagnosticBuilder<'a, G: EmissionGuarantee = ErrorGuaranteed> {
pub dcx: &'a DiagCtxt,
/// Why the `Option`? It is always `Some` until the `DiagnosticBuilder` is
/// consumed via `emit`, `cancel`, etc. At that point it is consumed and
/// replaced with `None`. Then `drop` checks that it is `None`; if not, it
/// panics because a diagnostic was built but not used.
///
/// Why the Box? `Diagnostic` is a large type, and `DiagnosticBuilder` is
/// often used as a return value, especially within the frequently-used
/// `PResult` type. In theory, return value optimization (RVO) should avoid
/// unnecessary copying. In practice, it does not (at the time of writing).
// FIXME(nnethercote) Make private once this moves to diagnostic.rs.
pub(crate) diag: Option<Box<Diagnostic>>,
// FIXME(nnethercote) Make private once this moves to diagnostic.rs.
pub(crate) _marker: PhantomData<G>,
}
// Cloning a `DiagnosticBuilder` is a recipe for a diagnostic being emitted
// twice, which would be bad.
impl<G> !Clone for DiagnosticBuilder<'_, G> {}
rustc_data_structures::static_assert_size!(
DiagnosticBuilder<'_, ()>,
2 * std::mem::size_of::<usize>()
);
impl<G: EmissionGuarantee> Deref for DiagnosticBuilder<'_, G> {
type Target = Diagnostic;
fn deref(&self) -> &Diagnostic {
self.diag.as_ref().unwrap()
}
}
impl<G: EmissionGuarantee> DerefMut for DiagnosticBuilder<'_, G> {
fn deref_mut(&mut self) -> &mut Diagnostic {
self.diag.as_mut().unwrap()
}
}
impl<G: EmissionGuarantee> Debug for DiagnosticBuilder<'_, G> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
self.diag.fmt(f)
}
}
/// `DiagnosticBuilder` impls many `&mut self -> &mut Self` methods. Each one
@ -382,6 +570,20 @@ macro_rules! with_fn {
}
impl<'a, G: EmissionGuarantee> DiagnosticBuilder<'a, G> {
#[rustc_lint_diagnostics]
#[track_caller]
pub fn new<M: Into<DiagnosticMessage>>(dcx: &'a DiagCtxt, level: Level, message: M) -> Self {
Self::new_diagnostic(dcx, Diagnostic::new(level, message))
}
/// Creates a new `DiagnosticBuilder` with an already constructed
/// diagnostic.
#[track_caller]
pub(crate) fn new_diagnostic(dcx: &'a DiagCtxt, diag: Diagnostic) -> Self {
debug!("Created new diagnostic");
Self { dcx, diag: Some(Box::new(diag)), _marker: PhantomData }
}
/// Delay emission of this diagnostic as a bug.
///
/// This can be useful in contexts where an error indicates a bug but
@ -1040,48 +1242,115 @@ impl<'a, G: EmissionGuarantee> DiagnosticBuilder<'a, G> {
let sub = SubDiagnostic { level, messages, span };
self.children.push(sub);
}
}
impl Diagnostic {
/// Fields used for Hash, and PartialEq trait
fn keys(
&self,
) -> (
&Level,
&[(DiagnosticMessage, Style)],
&Option<ErrCode>,
&MultiSpan,
&[SubDiagnostic],
&Result<Vec<CodeSuggestion>, SuggestionsDisabled>,
Vec<(&DiagnosticArgName, &DiagnosticArgValue)>,
&Option<IsLint>,
) {
(
&self.level,
&self.messages,
&self.code,
&self.span,
&self.children,
&self.suggestions,
self.args().collect(),
// omit self.sort_span
&self.is_lint,
// omit self.emitted_at
)
/// Takes the diagnostic. For use by methods that consume the
/// DiagnosticBuilder: `emit`, `cancel`, etc. Afterwards, `drop` is the
/// only code that will be run on `self`.
// FIXME(nnethercote) Make private once this moves to diagnostic.rs.
pub(crate) fn take_diag(&mut self) -> Diagnostic {
Box::into_inner(self.diag.take().unwrap())
}
/// Most `emit_producing_guarantee` functions use this as a starting point.
// FIXME(nnethercote) Make private once this moves to diagnostic.rs.
pub(crate) fn emit_producing_nothing(mut self) {
let diag = self.take_diag();
self.dcx.emit_diagnostic(diag);
}
/// `ErrorGuaranteed::emit_producing_guarantee` uses this.
// FIXME(nnethercote) Make private once this moves to diagnostic.rs.
pub(crate) fn emit_producing_error_guaranteed(mut self) -> ErrorGuaranteed {
let diag = self.take_diag();
// The only error levels that produce `ErrorGuaranteed` are
// `Error` and `DelayedBug`. But `DelayedBug` should never occur here
// because delayed bugs have their level changed to `Bug` when they are
// actually printed, so they produce an ICE.
//
// (Also, even though `level` isn't `pub`, the whole `Diagnostic` could
// be overwritten with a new one thanks to `DerefMut`. So this assert
// protects against that, too.)
assert!(
matches!(diag.level, Level::Error | Level::DelayedBug),
"invalid diagnostic level ({:?})",
diag.level,
);
let guar = self.dcx.emit_diagnostic(diag);
guar.unwrap()
}
/// Emit and consume the diagnostic.
#[track_caller]
pub fn emit(self) -> G::EmitResult {
G::emit_producing_guarantee(self)
}
/// Emit the diagnostic unless `delay` is true,
/// in which case the emission will be delayed as a bug.
///
/// See `emit` and `delay_as_bug` for details.
#[track_caller]
pub fn emit_unless(mut self, delay: bool) -> G::EmitResult {
if delay {
self.downgrade_to_delayed_bug();
}
self.emit()
}
/// Cancel and consume the diagnostic. (A diagnostic must either be emitted or
/// cancelled or it will panic when dropped).
pub fn cancel(mut self) {
self.diag = None;
drop(self);
}
/// Stashes diagnostic for possible later improvement in a different,
/// later stage of the compiler. The diagnostic can be accessed with
/// the provided `span` and `key` through [`DiagCtxt::steal_diagnostic()`].
pub fn stash(mut self, span: Span, key: StashKey) {
self.dcx.stash_diagnostic(span, key, self.take_diag());
}
/// Delay emission of this diagnostic as a bug.
///
/// This can be useful in contexts where an error indicates a bug but
/// typically this only happens when other compilation errors have already
/// happened. In those cases this can be used to defer emission of this
/// diagnostic as a bug in the compiler only if no other errors have been
/// emitted.
///
/// In the meantime, though, callsites are required to deal with the "bug"
/// locally in whichever way makes the most sense.
#[track_caller]
pub fn delay_as_bug(mut self) -> G::EmitResult {
self.downgrade_to_delayed_bug();
self.emit()
}
}
impl Hash for Diagnostic {
fn hash<H>(&self, state: &mut H)
where
H: Hasher,
{
self.keys().hash(state);
/// Destructor bomb: every `DiagnosticBuilder` must be consumed (emitted,
/// cancelled, etc.) or we emit a bug.
impl<G: EmissionGuarantee> Drop for DiagnosticBuilder<'_, G> {
fn drop(&mut self) {
match self.diag.take() {
Some(diag) if !panicking() => {
self.dcx.emit_diagnostic(Diagnostic::new(
Level::Bug,
DiagnosticMessage::from("the following error was constructed but not emitted"),
));
self.dcx.emit_diagnostic(*diag);
panic!("error was constructed but not emitted");
}
_ => {}
}
}
}
impl PartialEq for Diagnostic {
fn eq(&self, other: &Self) -> bool {
self.keys() == other.keys()
}
#[macro_export]
macro_rules! struct_span_code_err {
($dcx:expr, $span:expr, $code:expr, $($message:tt)*) => ({
$dcx.struct_span_err($span, format!($($message)*)).with_code($code)
})
}

View File

@ -1,282 +0,0 @@
use crate::{
DiagCtxt, Diagnostic, DiagnosticMessage, ErrorGuaranteed, ExplicitBug, Level, StashKey,
};
use rustc_span::source_map::Spanned;
use rustc_span::Span;
use std::fmt::{self, Debug};
use std::marker::PhantomData;
use std::ops::{Deref, DerefMut};
use std::panic;
use std::thread::panicking;
/// Trait implemented by error types. This is rarely implemented manually. Instead, use
/// `#[derive(Diagnostic)]` -- see [rustc_macros::Diagnostic].
#[rustc_diagnostic_item = "IntoDiagnostic"]
pub trait IntoDiagnostic<'a, G: EmissionGuarantee = ErrorGuaranteed> {
/// Write out as a diagnostic out of `DiagCtxt`.
#[must_use]
fn into_diagnostic(self, dcx: &'a DiagCtxt, level: Level) -> DiagnosticBuilder<'a, G>;
}
impl<'a, T, G> IntoDiagnostic<'a, G> for Spanned<T>
where
T: IntoDiagnostic<'a, G>,
G: EmissionGuarantee,
{
fn into_diagnostic(self, dcx: &'a DiagCtxt, level: Level) -> DiagnosticBuilder<'a, G> {
self.node.into_diagnostic(dcx, level).with_span(self.span)
}
}
/// Used for emitting structured error messages and other diagnostic information.
/// Wraps a `Diagnostic`, adding some useful things.
/// - The `dcx` field, allowing it to (a) emit itself, and (b) do a drop check
/// that it has been emitted or cancelled.
/// - The `EmissionGuarantee`, which determines the type returned from `emit`.
///
/// Each constructed `DiagnosticBuilder` must be consumed by a function such as
/// `emit`, `cancel`, `delay_as_bug`, or `into_diagnostic`. A panic occurrs if a
/// `DiagnosticBuilder` is dropped without being consumed by one of these
/// functions.
///
/// If there is some state in a downstream crate you would like to
/// access in the methods of `DiagnosticBuilder` here, consider
/// extending `DiagCtxtFlags`.
#[must_use]
pub struct DiagnosticBuilder<'a, G: EmissionGuarantee = ErrorGuaranteed> {
pub dcx: &'a DiagCtxt,
/// Why the `Option`? It is always `Some` until the `DiagnosticBuilder` is
/// consumed via `emit`, `cancel`, etc. At that point it is consumed and
/// replaced with `None`. Then `drop` checks that it is `None`; if not, it
/// panics because a diagnostic was built but not used.
///
/// Why the Box? `Diagnostic` is a large type, and `DiagnosticBuilder` is
/// often used as a return value, especially within the frequently-used
/// `PResult` type. In theory, return value optimization (RVO) should avoid
/// unnecessary copying. In practice, it does not (at the time of writing).
// FIXME(nnethercote) Make private once this moves to diagnostic.rs.
pub(crate) diag: Option<Box<Diagnostic>>,
// FIXME(nnethercote) Make private once this moves to diagnostic.rs.
pub(crate) _marker: PhantomData<G>,
}
// Cloning a `DiagnosticBuilder` is a recipe for a diagnostic being emitted
// twice, which would be bad.
impl<G> !Clone for DiagnosticBuilder<'_, G> {}
rustc_data_structures::static_assert_size!(
DiagnosticBuilder<'_, ()>,
2 * std::mem::size_of::<usize>()
);
/// Trait for types that `DiagnosticBuilder::emit` can return as a "guarantee"
/// (or "proof") token that the emission happened.
pub trait EmissionGuarantee: Sized {
/// This exists so that bugs and fatal errors can both result in `!` (an
/// abort) when emitted, but have different aborting behaviour.
type EmitResult = Self;
/// Implementation of `DiagnosticBuilder::emit`, fully controlled by each
/// `impl` of `EmissionGuarantee`, to make it impossible to create a value
/// of `Self::EmitResult` without actually performing the emission.
#[track_caller]
fn emit_producing_guarantee(db: DiagnosticBuilder<'_, Self>) -> Self::EmitResult;
}
impl<'a, G: EmissionGuarantee> DiagnosticBuilder<'a, G> {
/// Takes the diagnostic. For use by methods that consume the
/// DiagnosticBuilder: `emit`, `cancel`, etc. Afterwards, `drop` is the
/// only code that will be run on `self`.
// FIXME(nnethercote) Make private once this moves to diagnostic.rs.
pub(crate) fn take_diag(&mut self) -> Diagnostic {
Box::into_inner(self.diag.take().unwrap())
}
/// Most `emit_producing_guarantee` functions use this as a starting point.
// FIXME(nnethercote) Make private once this moves to diagnostic.rs.
pub(crate) fn emit_producing_nothing(mut self) {
let diag = self.take_diag();
self.dcx.emit_diagnostic(diag);
}
/// `ErrorGuaranteed::emit_producing_guarantee` uses this.
// FIXME(nnethercote) Make private once this moves to diagnostic.rs.
pub(crate) fn emit_producing_error_guaranteed(mut self) -> ErrorGuaranteed {
let diag = self.take_diag();
// The only error levels that produce `ErrorGuaranteed` are
// `Error` and `DelayedBug`. But `DelayedBug` should never occur here
// because delayed bugs have their level changed to `Bug` when they are
// actually printed, so they produce an ICE.
//
// (Also, even though `level` isn't `pub`, the whole `Diagnostic` could
// be overwritten with a new one thanks to `DerefMut`. So this assert
// protects against that, too.)
assert!(
matches!(diag.level, Level::Error | Level::DelayedBug),
"invalid diagnostic level ({:?})",
diag.level,
);
let guar = self.dcx.emit_diagnostic(diag);
guar.unwrap()
}
}
impl EmissionGuarantee for ErrorGuaranteed {
fn emit_producing_guarantee(db: DiagnosticBuilder<'_, Self>) -> Self::EmitResult {
db.emit_producing_error_guaranteed()
}
}
impl EmissionGuarantee for () {
fn emit_producing_guarantee(db: DiagnosticBuilder<'_, Self>) -> Self::EmitResult {
db.emit_producing_nothing();
}
}
/// Marker type which enables implementation of `create_bug` and `emit_bug` functions for
/// bug diagnostics.
#[derive(Copy, Clone)]
pub struct BugAbort;
impl EmissionGuarantee for BugAbort {
type EmitResult = !;
fn emit_producing_guarantee(db: DiagnosticBuilder<'_, Self>) -> Self::EmitResult {
db.emit_producing_nothing();
panic::panic_any(ExplicitBug);
}
}
/// Marker type which enables implementation of `create_fatal` and `emit_fatal` functions for
/// fatal diagnostics.
#[derive(Copy, Clone)]
pub struct FatalAbort;
impl EmissionGuarantee for FatalAbort {
type EmitResult = !;
fn emit_producing_guarantee(db: DiagnosticBuilder<'_, Self>) -> Self::EmitResult {
db.emit_producing_nothing();
crate::FatalError.raise()
}
}
impl EmissionGuarantee for rustc_span::fatal_error::FatalError {
fn emit_producing_guarantee(db: DiagnosticBuilder<'_, Self>) -> Self::EmitResult {
db.emit_producing_nothing();
rustc_span::fatal_error::FatalError
}
}
impl<G: EmissionGuarantee> Deref for DiagnosticBuilder<'_, G> {
type Target = Diagnostic;
fn deref(&self) -> &Diagnostic {
self.diag.as_ref().unwrap()
}
}
impl<G: EmissionGuarantee> DerefMut for DiagnosticBuilder<'_, G> {
fn deref_mut(&mut self) -> &mut Diagnostic {
self.diag.as_mut().unwrap()
}
}
impl<'a, G: EmissionGuarantee> DiagnosticBuilder<'a, G> {
#[rustc_lint_diagnostics]
#[track_caller]
pub fn new<M: Into<DiagnosticMessage>>(dcx: &'a DiagCtxt, level: Level, message: M) -> Self {
Self::new_diagnostic(dcx, Diagnostic::new(level, message))
}
/// Creates a new `DiagnosticBuilder` with an already constructed
/// diagnostic.
#[track_caller]
pub(crate) fn new_diagnostic(dcx: &'a DiagCtxt, diag: Diagnostic) -> Self {
debug!("Created new diagnostic");
Self { dcx, diag: Some(Box::new(diag)), _marker: PhantomData }
}
/// Emit and consume the diagnostic.
#[track_caller]
pub fn emit(self) -> G::EmitResult {
G::emit_producing_guarantee(self)
}
/// Emit the diagnostic unless `delay` is true,
/// in which case the emission will be delayed as a bug.
///
/// See `emit` and `delay_as_bug` for details.
#[track_caller]
pub fn emit_unless(mut self, delay: bool) -> G::EmitResult {
if delay {
self.downgrade_to_delayed_bug();
}
self.emit()
}
/// Cancel and consume the diagnostic. (A diagnostic must either be emitted or
/// cancelled or it will panic when dropped).
pub fn cancel(mut self) {
self.diag = None;
drop(self);
}
/// Stashes diagnostic for possible later improvement in a different,
/// later stage of the compiler. The diagnostic can be accessed with
/// the provided `span` and `key` through [`DiagCtxt::steal_diagnostic()`].
pub fn stash(mut self, span: Span, key: StashKey) {
self.dcx.stash_diagnostic(span, key, self.take_diag());
}
/// Delay emission of this diagnostic as a bug.
///
/// This can be useful in contexts where an error indicates a bug but
/// typically this only happens when other compilation errors have already
/// happened. In those cases this can be used to defer emission of this
/// diagnostic as a bug in the compiler only if no other errors have been
/// emitted.
///
/// In the meantime, though, callsites are required to deal with the "bug"
/// locally in whichever way makes the most sense.
#[track_caller]
pub fn delay_as_bug(mut self) -> G::EmitResult {
self.downgrade_to_delayed_bug();
self.emit()
}
}
impl<G: EmissionGuarantee> Debug for DiagnosticBuilder<'_, G> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
self.diag.fmt(f)
}
}
/// Destructor bomb: every `DiagnosticBuilder` must be consumed (emitted,
/// cancelled, etc.) or we emit a bug.
impl<G: EmissionGuarantee> Drop for DiagnosticBuilder<'_, G> {
fn drop(&mut self) {
match self.diag.take() {
Some(diag) if !panicking() => {
self.dcx.emit_diagnostic(Diagnostic::new(
Level::Bug,
DiagnosticMessage::from("the following error was constructed but not emitted"),
));
self.dcx.emit_diagnostic(*diag);
panic!("error was constructed but not emitted");
}
_ => {}
}
}
}
#[macro_export]
macro_rules! struct_span_code_err {
($dcx:expr, $span:expr, $code:expr, $($message:tt)*) => ({
$dcx.struct_span_err($span, format!($($message)*)).with_code($code)
})
}

View File

@ -37,12 +37,9 @@ extern crate self as rustc_errors;
pub use codes::*;
pub use diagnostic::{
AddToDiagnostic, DecorateLint, Diagnostic, DiagnosticArg, DiagnosticArgName,
DiagnosticArgValue, DiagnosticStyledString, IntoDiagnosticArg, StringPart, SubDiagnostic,
SubdiagnosticMessageOp,
};
pub use diagnostic_builder::{
BugAbort, DiagnosticBuilder, EmissionGuarantee, FatalAbort, IntoDiagnostic,
AddToDiagnostic, BugAbort, DecorateLint, Diagnostic, DiagnosticArg, DiagnosticArgName,
DiagnosticArgValue, DiagnosticBuilder, DiagnosticStyledString, EmissionGuarantee, FatalAbort,
IntoDiagnostic, IntoDiagnosticArg, StringPart, SubDiagnostic, SubdiagnosticMessageOp,
};
pub use diagnostic_impls::{
DiagnosticArgFromDisplay, DiagnosticSymbolList, ExpectedLifetimeParameter,
@ -87,7 +84,6 @@ use Level::*;
pub mod annotate_snippet_emitter_writer;
pub mod codes;
mod diagnostic;
mod diagnostic_builder;
mod diagnostic_impls;
pub mod emitter;
pub mod error;

View File

@ -8,7 +8,7 @@ LL | arg: NotIntoDiagnosticArg,
| ^^^^^^^^^^^^^^^^^^^^ the trait `IntoDiagnosticArg` is not implemented for `NotIntoDiagnosticArg`
|
= help: normalized in stderr
note: required by a bound in `rustc_errors::diagnostic::<impl DiagnosticBuilder<'a, G>>::arg`
note: required by a bound in `DiagnosticBuilder::<'a, G>::arg`
--> $COMPILER_DIR/rustc_errors/src/diagnostic.rs:LL:CC
= note: this error originates in the macro `with_fn` (in Nightly builds, run with -Z macro-backtrace for more info)
@ -22,7 +22,7 @@ LL | arg: NotIntoDiagnosticArg,
| ^^^^^^^^^^^^^^^^^^^^ the trait `IntoDiagnosticArg` is not implemented for `NotIntoDiagnosticArg`
|
= help: normalized in stderr
note: required by a bound in `rustc_errors::diagnostic::<impl DiagnosticBuilder<'a, G>>::arg`
note: required by a bound in `DiagnosticBuilder::<'a, G>::arg`
--> $COMPILER_DIR/rustc_errors/src/diagnostic.rs:LL:CC
= note: this error originates in the macro `with_fn` (in Nightly builds, run with -Z macro-backtrace for more info)

View File

@ -628,7 +628,7 @@ LL | other: Hello,
| ^^^^^ the trait `IntoDiagnosticArg` is not implemented for `Hello`
|
= help: normalized in stderr
note: required by a bound in `rustc_errors::diagnostic::<impl DiagnosticBuilder<'a, G>>::arg`
note: required by a bound in `DiagnosticBuilder::<'a, G>::arg`
--> $COMPILER_DIR/rustc_errors/src/diagnostic.rs:LL:CC
= note: this error originates in the macro `with_fn` (in Nightly builds, run with -Z macro-backtrace for more info)