Auto merge of #125507 - compiler-errors:type-length-limit, r=lcnr

Re-implement a type-size based limit

r? lcnr

This PR reintroduces the type length limit added in #37789, which was accidentally made practically useless by the caching changes to `Ty::walk` in #72412, which caused the `walk` function to no longer walk over identical elements.

Hitting this length limit is not fatal unless we are in codegen -- so it shouldn't affect passes like the mir inliner which creates potentially very large types (which we observed, for example, when the new trait solver compiles `itertools` in `--release` mode).

This also increases the type length limit from `1048576 == 2 ** 20` to `2 ** 24`, which covers all of the code that can be reached with craterbot-check. Individual crates can increase the length limit further if desired.

Perf regression is mild and I think we should accept it -- reinstating this limit is important for the new trait solver and to make sure we don't accidentally hit more type-size related regressions in the future.

Fixes #125460
This commit is contained in:
bors 2024-07-03 11:56:36 +00:00
commit b52ac9a89a
2 changed files with 3 additions and 3 deletions

View File

@ -103,7 +103,7 @@ fn extract_call<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) -> Option<
let args = cx.typeck_results().node_args(expr.hir_id); let args = cx.typeck_results().node_args(expr.hir_id);
// If we could not resolve the method, don't apply the lint // If we could not resolve the method, don't apply the lint
let Ok(Some(resolved_method)) = Instance::resolve(cx.tcx, cx.param_env, fn_def_id, args) else { let Ok(Some(resolved_method)) = Instance::try_resolve(cx.tcx, cx.param_env, fn_def_id, args) else {
return None; return None;
}; };
if is_trait_method(cx, expr, sym::Clone) && path.ident.name == sym::clone { if is_trait_method(cx, expr, sym::Clone) && path.ident.name == sym::clone {
@ -119,7 +119,7 @@ fn extract_call<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) -> Option<
// If we could not resolve the method, don't apply the lint // If we could not resolve the method, don't apply the lint
let Ok(Some(resolved_method)) = (match kind { let Ok(Some(resolved_method)) = (match kind {
ty::FnDef(_, args) => Instance::resolve(cx.tcx, cx.param_env, fn_def_id, args), ty::FnDef(_, args) => Instance::try_resolve(cx.tcx, cx.param_env, fn_def_id, args),
_ => Ok(None), _ => Ok(None),
}) else { }) else {
return None; return None;

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@ -293,7 +293,7 @@ pub fn const_eval_resolve(
ct: ty::UnevaluatedConst<'tcx>, ct: ty::UnevaluatedConst<'tcx>,
span: Span, span: Span,
) -> EvalToValTreeResult<'tcx> { ) -> EvalToValTreeResult<'tcx> {
match ty::Instance::resolve(tcx, param_env, ct.def, ct.args) { match ty::Instance::try_resolve(tcx, param_env, ct.def, ct.args) {
Ok(Some(instance)) => { Ok(Some(instance)) => {
let cid = GlobalId { let cid = GlobalId {
instance, instance,