compiler/rustc_middle/src/util/bug.rs

   1 // These functions are used by macro expansion for bug! and span_bug!
   2
   3 use crate::ty::{tls, TyCtxt};
   4 use rustc_errors::MultiSpan;
   5 use rustc_span::Span;
   6 use std::fmt;
   7 use std::panic::{panic_any, Location};
   8
   9 #[cold]
  10 #[inline(never)]
  11 #[track_caller]
  12 pub fn bug_fmt(args: fmt::Arguments<'_>) -> ! {
  13     // this wrapper mostly exists so I don't have to write a fully
  14     // qualified path of None::<Span> inside the bug!() macro definition
  15     opt_span_bug_fmt(None::<Span>, args, Location::caller());
  16 }
  17
  18 #[cold]
  19 #[inline(never)]
  20 #[track_caller]
  21 pub fn span_bug_fmt<S: Into<MultiSpan>>(span: S, args: fmt::Arguments<'_>) -> ! {
  22     opt_span_bug_fmt(Some(span), args, Location::caller());
  23 }
  24
  25 #[track_caller]
  26 fn opt_span_bug_fmt<S: Into<MultiSpan>>(
  27     span: Option<S>,
  28     args: fmt::Arguments<'_>,
  29     location: &Location<'_>,
  30 ) -> ! {
  31     tls::with_opt(move |tcx| {
  32         let msg = format!("{}: {}", location, args);
  33         match (tcx, span) {
  34             (Some(tcx), Some(span)) => tcx.sess.diagnostic().span_bug(span, &msg),
  35             (Some(tcx), None) => tcx.sess.diagnostic().bug(&msg),
  36             (None, _) => panic_any(msg),
  37         }
  38     });
  39     unreachable!();
  40 }
  41
  42 /// A query to trigger a `delay_span_bug`. Clearly, if one has a `tcx` one can already trigger a
  43 /// `delay_span_bug`, so what is the point of this? It exists to help us test `delay_span_bug`'s
  44 /// interactions with the query system and incremental.
  45 pub fn trigger_delay_span_bug(tcx: TyCtxt<'_>, key: rustc_hir::def_id::DefId) {
  46     tcx.sess.delay_span_bug(
  47         tcx.def_span(key),
  48         "delayed span bug triggered by #[rustc_error(delay_span_bug_from_inside_query)]",
  49     );
  50 }
  51
  52 pub fn provide(providers: &mut crate::ty::query::Providers) {
  53     *providers = crate::ty::query::Providers { trigger_delay_span_bug, ..*providers };
  54 }