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Auto merge of #107542 - compiler-errors:param-envs-with-inference-vars-are-cursed, r=jackh726

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Don't call `with_reveal_all_normalized` in const-eval when `param_env` has inference vars in it

**what:** This slightly shifts the order of operations from an existing hack:

5b6ed253c4/compiler/rustc_middle/src/ty/consts/kind.rs (L225-L230)

in order to avoid calling a tcx query (`TyCtxt::reveal_opaque_types_in_bounds`, via `ParamEnv::with_reveal_all_normalized`) when a param-env has inference variables in it.

**why:** This allows us to enable fingerprinting of query keys/values outside of incr-comp in deubg mode, to make sure we catch other places where we're passing infer vars and other bad things into query keys. Currently that (bbf33836b9) crashes because we introduce inference vars into a param-env in the blanket-impl finder in rustdoc 😓

5b6ed253c4/src/librustdoc/clean/blanket_impl.rs (L43)

See the CI failure here: https://github.com/rust-lang/rust/actions/runs/4058194838/jobs/6984834619
This commit is contained in:
bors 2023-02-18 23:43:42 +00:00
commit f77f4d55bd
3 changed files with 23 additions and 7 deletions
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10
compiler/rustc_middle/src/ty/consts/kind.rs
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@ -217,23 +217,21 @@ impl<'tcx> ConstKind<'tcx> {
// Note that we erase regions *before* calling `with_reveal_all_normalized`,
// so that we don't try to invoke this query with
// any region variables.
let param_env_and = tcx
.erase_regions(param_env)
.with_reveal_all_normalized(tcx)
.and(tcx.erase_regions(unevaluated));
// HACK(eddyb) when the query key would contain inference variables,
// attempt using identity substs and `ParamEnv` instead, that will succeed
// when the expression doesn't depend on any parameters.
// FIXME(eddyb, skinny121) pass `InferCtxt` into here when it's available, so that
// we can call `infcx.const_eval_resolve` which handles inference variables.
let param_env_and = if param_env_and.needs_infer() {
let param_env_and = if (param_env, unevaluated).has_non_region_infer() {
tcx.param_env(unevaluated.def.did).and(ty::UnevaluatedConst {
def: unevaluated.def,
substs: InternalSubsts::identity_for_item(tcx, unevaluated.def.did),
})
} else {
param_env_and
tcx.erase_regions(param_env)
.with_reveal_all_normalized(tcx)
.and(tcx.erase_regions(unevaluated))
};
// FIXME(eddyb) maybe the `const_eval_*` methods should take