bjoernager/rust
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Rollup merge of #121208 - nnethercote:delayed_bug-to-bug, r=lcnr

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Convert `delayed_bug`s to `bug`s.

I have a suspicion that quite a few delayed bug paths are impossible to reach, so I did an experiment.

I converted every `delayed_bug` to a `bug`, ran the full test suite, then converted back every `bug` that was hit. A surprising number were never hit.

This is too dangerous to merge. Increased coverage (fuzzing or a crater run) would likely hit more cases. But it might be useful for people to look at and think about which paths are genuinely unreachable.

r? `@ghost`
This commit is contained in:
Dylan DPC 2024-02-21 08:55:56 +00:00 • committed by GitHub
commit d5206c6ecd
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39 changed files with 130 additions and 155 deletions
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15
compiler/rustc_mir_build/src/build/expr/as_constant.rs
View file

@ -110,15 +110,12 @@ fn lit_to_mir_constant<'tcx>(
let LitToConstInput { lit, ty, neg } = lit_input;
let trunc = |n| {
let param_ty = ty::ParamEnv::reveal_all().and(ty);
let width =
tcx.layout_of(param_ty)
.map_err(|_| {
LitToConstError::Reported(tcx.dcx().delayed_bug(format!(
"couldn't compute width of literal: {:?}",
lit_input.lit
)))
})?
.size;
let width = match tcx.layout_of(param_ty) {
Ok(layout) => layout.size,
Err(_) => {
tcx.dcx().bug(format!("couldn't compute width of literal: {:?}", lit_input.lit))
}
};
trace!("trunc {} with size {} and shift {}", n, width.bits(), 128 - width.bits());
let result = width.truncate(n);
trace!("trunc result: {}", result);

29
compiler/rustc_mir_build/src/thir/constant.rs
View file

@ -12,15 +12,12 @@ pub(crate) fn lit_to_const<'tcx>(
let trunc = |n| {
let param_ty = ParamEnv::reveal_all().and(ty);
let width =
tcx.layout_of(param_ty)
.map_err(|_| {
LitToConstError::Reported(tcx.dcx().delayed_bug(format!(
"couldn't compute width of literal: {:?}",
lit_input.lit
)))
})?
.size;
let width = match tcx.layout_of(param_ty) {
Ok(layout) => layout.size,
Err(_) => {
tcx.dcx().bug(format!("couldn't compute width of literal: {:?}", lit_input.lit))
}
};
trace!("trunc {} with size {} and shift {}", n, width.bits(), 128 - width.bits());
let result = width.truncate(n);
trace!("trunc result: {}", result);
@ -59,15 +56,11 @@ pub(crate) fn lit_to_const<'tcx>(
}
(ast::LitKind::Bool(b), ty::Bool) => ty::ValTree::from_scalar_int((*b).into()),
(ast::LitKind::Float(n, _), ty::Float(fty)) => {
let bits =
parse_float_into_scalar(*n, *fty, neg)
.ok_or_else(|| {
LitToConstError::Reported(tcx.dcx().delayed_bug(format!(
"couldn't parse float literal: {:?}",
lit_input.lit
)))
})?
.assert_int();
let bits = parse_float_into_scalar(*n, *fty, neg)
.ok_or_else(|| {
tcx.dcx().bug(format!("couldn't parse float literal: {:?}", lit_input.lit))
})?
.assert_int();
ty::ValTree::from_scalar_int(bits)
}
(ast::LitKind::Char(c), ty::Char) => ty::ValTree::from_scalar_int((*c).into()),

2
compiler/rustc_mir_build/src/thir/pattern/mod.rs
View file

@ -175,7 +175,7 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> {
) -> Result<PatKind<'tcx>, ErrorGuaranteed> {
if lo_expr.is_none() && hi_expr.is_none() {
let msg = "found twice-open range pattern (`..`) outside of error recovery";
return Err(self.tcx.dcx().span_delayed_bug(span, msg));
self.tcx.dcx().span_bug(span, msg);
}
let (lo, lo_ascr, lo_inline) = self.lower_pattern_range_endpoint(lo_expr)?;