From 729eb0a6e34842dba17b0be871ad961e8be6d328 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 19:19:21 +0000
Subject: [PATCH 01/36] mark first uncovered DefineOpaqueTypes in
 visit_implementation_of_dispatch_from_dyn

---
 compiler/rustc_hir_analysis/src/coherence/builtin.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/compiler/rustc_hir_analysis/src/coherence/builtin.rs b/compiler/rustc_hir_analysis/src/coherence/builtin.rs
index e5e192e0079bd..61fadc6b27395 100644
--- a/compiler/rustc_hir_analysis/src/coherence/builtin.rs
+++ b/compiler/rustc_hir_analysis/src/coherence/builtin.rs
@@ -165,6 +165,7 @@ fn visit_implementation_of_dispatch_from_dyn(tcx: TyCtxt<'_>, impl_did: LocalDef
     use rustc_type_ir::TyKind::*;
     match (source.kind(), target.kind()) {
         (&Ref(r_a, _, mutbl_a), Ref(r_b, _, mutbl_b))
+            // FIXME(DefineOpaqueTypes): no test exercizes using `DefineOpaqueTypes::Yes` below.
             if infcx.at(&cause, param_env).eq(DefineOpaqueTypes::No, r_a, *r_b).is_ok()
                 && mutbl_a == *mutbl_b => {}
         (&RawPtr(tm_a), &RawPtr(tm_b)) if tm_a.mutbl == tm_b.mutbl => (),

From c87df67088cd7e030f87474d875757d0c1b04d4c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 19:28:26 +0000
Subject: [PATCH 02/36] mark second uncovered DefineOpaqueTypes in
 visit_implementation_of_dispatch_from_dyn

---
 compiler/rustc_hir_analysis/src/coherence/builtin.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/compiler/rustc_hir_analysis/src/coherence/builtin.rs b/compiler/rustc_hir_analysis/src/coherence/builtin.rs
index 61fadc6b27395..fdc9b00544e49 100644
--- a/compiler/rustc_hir_analysis/src/coherence/builtin.rs
+++ b/compiler/rustc_hir_analysis/src/coherence/builtin.rs
@@ -204,6 +204,8 @@ fn visit_implementation_of_dispatch_from_dyn(tcx: TyCtxt<'_>, impl_did: LocalDef
                         }
                     }
 
+                    // FIXME(DefineOpaqueTypes): no test exercizes using `DefineOpaqueTypes::Yes`
+                    // below.
                     if let Ok(ok) =
                         infcx.at(&cause, param_env).eq(DefineOpaqueTypes::No, ty_a, ty_b)
                     {

From c794ec36bd7da1c8a51e01065a8bdbb3d4fc01fd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 19:33:39 +0000
Subject: [PATCH 03/36] mark first uncovered DefineOpaqueTypes in
 coerce_unsized_info

---
 compiler/rustc_hir_analysis/src/coherence/builtin.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/compiler/rustc_hir_analysis/src/coherence/builtin.rs b/compiler/rustc_hir_analysis/src/coherence/builtin.rs
index fdc9b00544e49..f81e95cc7408d 100644
--- a/compiler/rustc_hir_analysis/src/coherence/builtin.rs
+++ b/compiler/rustc_hir_analysis/src/coherence/builtin.rs
@@ -409,6 +409,8 @@ pub fn coerce_unsized_info<'tcx>(tcx: TyCtxt<'tcx>, impl_did: LocalDefId) -> Coe
                     // we may have to evaluate constraint
                     // expressions in the course of execution.)
                     // See e.g., #41936.
+                    // FIXME(DefineOpaqueTypes): no test exercizes using `DefineOpaqueTypes::Yes`
+                    // below.
                     if let Ok(ok) = infcx.at(&cause, param_env).eq(DefineOpaqueTypes::No, a, b) {
                         if ok.obligations.is_empty() {
                             return None;

From c5d5bf0232e5dd8a1374d94c0f29beb329130c6e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 19:37:13 +0000
Subject: [PATCH 04/36] mark first uncovered DefineOpaqueTypes in
 enforce_context_effects

---
 compiler/rustc_hir_typeck/src/callee.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/compiler/rustc_hir_typeck/src/callee.rs b/compiler/rustc_hir_typeck/src/callee.rs
index 6b6d1574b2bf6..ef54ea467ea52 100644
--- a/compiler/rustc_hir_typeck/src/callee.rs
+++ b/compiler/rustc_hir_typeck/src/callee.rs
@@ -799,6 +799,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         let param = callee_args.const_at(host_effect_index);
         let cause = self.misc(span);
+        // FIXME(DefineOpaqueTypes): no test exercizes using `DefineOpaqueTypes::Yes` below.
         match self.at(&cause, self.param_env).eq(infer::DefineOpaqueTypes::No, effect, param) {
             Ok(infer::InferOk { obligations, value: () }) => {
                 self.register_predicates(obligations);

From 408b8c071b40529a8bd785c04eac39eeb7eb76ea Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 19:40:59 +0000
Subject: [PATCH 05/36] mark first uncovered DefineOpaqueTypes in
 try_find_coercion_lub

---
 compiler/rustc_hir_typeck/src/coercion.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/compiler/rustc_hir_typeck/src/coercion.rs b/compiler/rustc_hir_typeck/src/coercion.rs
index 6c03bc3b57ac6..de376612b7f96 100644
--- a/compiler/rustc_hir_typeck/src/coercion.rs
+++ b/compiler/rustc_hir_typeck/src/coercion.rs
@@ -1139,6 +1139,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         // Don't reify if the function types have a LUB, i.e., they
                         // are the same function and their parameters have a LUB.
                         match self.commit_if_ok(|_| {
+                            // FIXME(DefineOpaqueTypes): no test exercizes using
+                            // `DefineOpaqueTypes::Yes` below.
                             self.at(cause, self.param_env).lub(
                                 DefineOpaqueTypes::No,
                                 prev_ty,

From f0b7ac0d08e140799266aba71b32c05412b7c294 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 19:43:50 +0000
Subject: [PATCH 06/36] mark second uncovered DefineOpaqueTypes in
 try_find_coercion_lub

---
 compiler/rustc_hir_typeck/src/coercion.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/compiler/rustc_hir_typeck/src/coercion.rs b/compiler/rustc_hir_typeck/src/coercion.rs
index de376612b7f96..ce7447edb3b96 100644
--- a/compiler/rustc_hir_typeck/src/coercion.rs
+++ b/compiler/rustc_hir_typeck/src/coercion.rs
@@ -1193,6 +1193,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             }
             // The signature must match.
             let (a_sig, b_sig) = self.normalize(new.span, (a_sig, b_sig));
+            // FIXME(DefineOpaqueTypes): no test exercizes using `DefineOpaqueTypes::Yes` below.
             let sig = self
                 .at(cause, self.param_env)
                 .trace(prev_ty, new_ty)

From b7fecd276aa5e66ca1861cfa77e90c56eb4613bd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 19:47:42 +0000
Subject: [PATCH 07/36] mark third uncovered DefineOpaqueTypes in
 try_find_coercion_lub

---
 compiler/rustc_hir_typeck/src/coercion.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/compiler/rustc_hir_typeck/src/coercion.rs b/compiler/rustc_hir_typeck/src/coercion.rs
index ce7447edb3b96..86da7cffd2312 100644
--- a/compiler/rustc_hir_typeck/src/coercion.rs
+++ b/compiler/rustc_hir_typeck/src/coercion.rs
@@ -1286,6 +1286,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
                 return self
                     .commit_if_ok(|_| {
+                        // FIXME(DefineOpaqueTypes): no test exercizes using
+                        // `DefineOpaqueTypes::Yes` below.
                         self.at(cause, self.param_env).lub(DefineOpaqueTypes::No, prev_ty, new_ty)
                     })
                     .map(|ok| self.register_infer_ok_obligations(ok));

From d759e2c13cbb74e20d3b3df74b512e301f427a5b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 19:50:24 +0000
Subject: [PATCH 08/36] mark fourth uncovered DefineOpaqueTypes in
 try_find_coercion_lub

---
 compiler/rustc_hir_typeck/src/coercion.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/compiler/rustc_hir_typeck/src/coercion.rs b/compiler/rustc_hir_typeck/src/coercion.rs
index 86da7cffd2312..8eee0c6f754a4 100644
--- a/compiler/rustc_hir_typeck/src/coercion.rs
+++ b/compiler/rustc_hir_typeck/src/coercion.rs
@@ -1301,6 +1301,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     Err(e)
                 } else {
                     self.commit_if_ok(|_| {
+                        // FIXME(DefineOpaqueTypes): no test exercizes using
+                        // `DefineOpaqueTypes::Yes` below.
                         self.at(cause, self.param_env).lub(DefineOpaqueTypes::No, prev_ty, new_ty)
                     })
                     .map(|ok| self.register_infer_ok_obligations(ok))

From 1febe8a761000378c99dafab522910c3bb9bf207 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 19:53:40 +0000
Subject: [PATCH 09/36] mark first uncovered DefineOpaqueTypes in
 check_expr_struct_fields

---
 compiler/rustc_hir_typeck/src/expr.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/compiler/rustc_hir_typeck/src/expr.rs b/compiler/rustc_hir_typeck/src/expr.rs
index be225ceb84321..e8cbe92009b48 100644
--- a/compiler/rustc_hir_typeck/src/expr.rs
+++ b/compiler/rustc_hir_typeck/src/expr.rs
@@ -1745,6 +1745,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             if let Some(_) = remaining_fields.remove(&ident) {
                                 let target_ty = self.field_ty(base_expr.span, f, args);
                                 let cause = self.misc(base_expr.span);
+                                // FIXME(DefineOpaqueTypes): no test exercizes using
+                                // `DefineOpaqueTypes::Yes` below.
                                 match self.at(&cause, self.param_env).sup(
                                     DefineOpaqueTypes::No,
                                     target_ty,

From db707589003309e6083cef86722faa9aee0fa4f2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 20:00:11 +0000
Subject: [PATCH 10/36] mark first uncovered DefineOpaqueTypes in
 instantiate_value_path

---
 compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
index b5a07f0d3e9ec..614d06734a0bc 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
@@ -1422,6 +1422,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             // This also occurs for an enum variant on a type alias.
             let impl_ty = self.normalize(span, tcx.type_of(impl_def_id).instantiate(tcx, args));
             let self_ty = self.normalize(span, self_ty);
+            // FIXME(DefineOpaqueTypes): no test exercizes using `DefineOpaqueTypes::Yes` below.
             match self.at(&self.misc(span), self.param_env).eq(
                 DefineOpaqueTypes::No,
                 impl_ty,

From c30d3e2b736befce04dd6ed4ea215d507173f0f6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 20:05:41 +0000
Subject: [PATCH 11/36] mark first uncovered DefineOpaqueTypes in
 check_argument_types

---
 compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
index 33dfa16a651fb..7783de6a75889 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
@@ -300,6 +300,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
             // 3. Check if the formal type is a supertype of the checked one
             //    and register any such obligations for future type checks
+            // FIXME(DefineOpaqueTypes): no test exercizes using `DefineOpaqueTypes::Yes` below.
             let supertype_error = self.at(&self.misc(provided_arg.span), self.param_env).sup(
                 DefineOpaqueTypes::No,
                 formal_input_ty,

From 910446d36df5b691b4267077c74e8d4d307fa520 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 20:05:57 +0000
Subject: [PATCH 12/36] mark first uncovered DefineOpaqueTypes in
 report_arg_errors

---
 compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
index 7783de6a75889..028297b4adb65 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
@@ -595,6 +595,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             }
 
             // Using probe here, since we don't want this subtyping to affect inference.
+            // FIXME(DefineOpaqueTypes): no test exercizes using `DefineOpaqueTypes::Yes` below.
             let subtyping_error = self.probe(|_| {
                 self.at(&self.misc(arg_span), self.param_env)
                     .sup(DefineOpaqueTypes::No, formal_input_ty, coerced_ty)

From fe2163c9db390887d5ac1ba47196a2d2634a28f4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 20:10:23 +0000
Subject: [PATCH 13/36] mark first uncovered DefineOpaqueTypes in
 unify_receivers

---
 compiler/rustc_hir_typeck/src/method/confirm.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/compiler/rustc_hir_typeck/src/method/confirm.rs b/compiler/rustc_hir_typeck/src/method/confirm.rs
index 7c73f6a89cdb2..7c65f9f5df743 100644
--- a/compiler/rustc_hir_typeck/src/method/confirm.rs
+++ b/compiler/rustc_hir_typeck/src/method/confirm.rs
@@ -502,6 +502,7 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> {
                 args,
             })),
         );
+        // FIXME(DefineOpaqueTypes): no test exercizes using `DefineOpaqueTypes::Yes` below.
         match self.at(&cause, self.param_env).sup(DefineOpaqueTypes::No, method_self_ty, self_ty) {
             Ok(InferOk { obligations, value: () }) => {
                 self.register_predicates(obligations);

From e3090499385bf6fa40bcabb4f95ad94af46f73a6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 20:14:05 +0000
Subject: [PATCH 14/36] mark first uncovered DefineOpaqueTypes in
 matches_return_type

---
 compiler/rustc_hir_typeck/src/method/probe.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/compiler/rustc_hir_typeck/src/method/probe.rs b/compiler/rustc_hir_typeck/src/method/probe.rs
index 74f469cb39cbf..2224274e248fd 100644
--- a/compiler/rustc_hir_typeck/src/method/probe.rs
+++ b/compiler/rustc_hir_typeck/src/method/probe.rs
@@ -933,6 +933,8 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
                 let fty = self.instantiate_binder_with_fresh_vars(self.span, infer::FnCall, fty);
 
                 if let Some(self_ty) = self_ty {
+                    // FIXME(DefineOpaqueTypes): no test exercizes using `DefineOpaqueTypes::Yes`
+                    // below.
                     if self
                         .at(&ObligationCause::dummy(), self.param_env)
                         .sup(DefineOpaqueTypes::No, fty.inputs()[0], self_ty)

From c27ac58683c89c2c966fdd93d49f7630a5fc78a0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 20:21:11 +0000
Subject: [PATCH 15/36] mark first uncovered DefineOpaqueTypes in
 candidate_source

---
 compiler/rustc_hir_typeck/src/method/probe.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/compiler/rustc_hir_typeck/src/method/probe.rs b/compiler/rustc_hir_typeck/src/method/probe.rs
index 2224274e248fd..d5f033a964b89 100644
--- a/compiler/rustc_hir_typeck/src/method/probe.rs
+++ b/compiler/rustc_hir_typeck/src/method/probe.rs
@@ -1455,6 +1455,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
                 CandidateSource::Trait(candidate.item.container_id(self.tcx))
             }
             TraitCandidate(trait_ref) => self.probe(|_| {
+                // FIXME(DefineOpaqueTypes): no test exercizes using `DefineOpaqueTypes::Yes` below.
                 let _ = self.at(&ObligationCause::dummy(), self.param_env).sup(
                     DefineOpaqueTypes::No,
                     candidate.xform_self_ty,

From 1d9b5a1133036cd5119209b08da3c3b3b2cea9ec Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 20:29:07 +0000
Subject: [PATCH 16/36] mark first uncovered DefineOpaqueTypes in
 consider_probe

---
 compiler/rustc_hir_typeck/src/method/probe.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/compiler/rustc_hir_typeck/src/method/probe.rs b/compiler/rustc_hir_typeck/src/method/probe.rs
index d5f033a964b89..c76b9a36f7fa7 100644
--- a/compiler/rustc_hir_typeck/src/method/probe.rs
+++ b/compiler/rustc_hir_typeck/src/method/probe.rs
@@ -1693,6 +1693,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
                 }
 
                 debug!("comparing return_ty {:?} with xform ret ty {:?}", return_ty, xform_ret_ty);
+                // FIXME(DefineOpaqueTypes): no test exercizes using `DefineOpaqueTypes::Yes` below.
                 if let ProbeResult::Match = result
                     && self
                         .at(&ObligationCause::dummy(), self.param_env)

From 25e59abece82bda43255ddb856535c8afbe610e8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 20:33:09 +0000
Subject: [PATCH 17/36] mark first uncovered DefineOpaqueTypes in can_sub

---
 compiler/rustc_infer/src/infer/mod.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/compiler/rustc_infer/src/infer/mod.rs b/compiler/rustc_infer/src/infer/mod.rs
index 4ee897ffe9843..993c2291358fb 100644
--- a/compiler/rustc_infer/src/infer/mod.rs
+++ b/compiler/rustc_infer/src/infer/mod.rs
@@ -908,6 +908,7 @@ impl<'tcx> InferCtxt<'tcx> {
         T: at::ToTrace<'tcx>,
     {
         let origin = &ObligationCause::dummy();
+        // FIXME(DefineOpaqueTypes): no test exercizes using `DefineOpaqueTypes::Yes` below.
         self.probe(|_| self.at(origin, param_env).sub(DefineOpaqueTypes::No, a, b).is_ok())
     }
 

From cc1bd62d3a60f16330f0a43159ca19c4b9dbef8c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 20:37:56 +0000
Subject: [PATCH 18/36] mark first uncovered DefineOpaqueTypes in can_eq

---
 compiler/rustc_infer/src/infer/mod.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/compiler/rustc_infer/src/infer/mod.rs b/compiler/rustc_infer/src/infer/mod.rs
index 993c2291358fb..ca140da3e7e8f 100644
--- a/compiler/rustc_infer/src/infer/mod.rs
+++ b/compiler/rustc_infer/src/infer/mod.rs
@@ -917,6 +917,7 @@ impl<'tcx> InferCtxt<'tcx> {
         T: at::ToTrace<'tcx>,
     {
         let origin = &ObligationCause::dummy();
+        // FIXME(DefineOpaqueTypes): no test exercizes using `DefineOpaqueTypes::Yes` below.
         self.probe(|_| self.at(origin, param_env).eq(DefineOpaqueTypes::No, a, b).is_ok())
     }
 

From b5c08453d0958cc999a41b01efccf6f4f0f1cd65 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 20:43:25 +0000
Subject: [PATCH 19/36] mark first uncovered DefineOpaqueTypes in
 subtype_predicate

---
 compiler/rustc_infer/src/infer/mod.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/compiler/rustc_infer/src/infer/mod.rs b/compiler/rustc_infer/src/infer/mod.rs
index ca140da3e7e8f..33eada32414fc 100644
--- a/compiler/rustc_infer/src/infer/mod.rs
+++ b/compiler/rustc_infer/src/infer/mod.rs
@@ -1013,6 +1013,7 @@ impl<'tcx> InferCtxt<'tcx> {
             let ty::SubtypePredicate { a_is_expected, a, b } =
                 self.instantiate_binder_with_placeholders(predicate);
 
+            // FIXME(DefineOpaqueTypes): no test exercizes using `DefineOpaqueTypes::Yes` below.
             let ok =
                 self.at(cause, param_env).sub_exp(DefineOpaqueTypes::No, a_is_expected, a, b)?;
 

From a247d09a245fb3dd548398360f41bb60d939c2f7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 20:47:18 +0000
Subject: [PATCH 20/36] mark first uncovered DefineOpaqueTypes in
 evaluate_nested_obligations

---
 compiler/rustc_trait_selection/src/traits/auto_trait.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/compiler/rustc_trait_selection/src/traits/auto_trait.rs b/compiler/rustc_trait_selection/src/traits/auto_trait.rs
index 8096d7969f397..1704f743733b2 100644
--- a/compiler/rustc_trait_selection/src/traits/auto_trait.rs
+++ b/compiler/rustc_trait_selection/src/traits/auto_trait.rs
@@ -804,6 +804,8 @@ impl<'tcx> AutoTraitFinder<'tcx> {
 
                     match (evaluate(c1), evaluate(c2)) {
                         (Ok(c1), Ok(c2)) => {
+                            // FIXME(DefineOpaqueTypes): no test exercizes using
+                            // `DefineOpaqueTypes::Yes` below.
                             match selcx.infcx.at(&obligation.cause, obligation.param_env).eq(DefineOpaqueTypes::No,c1, c2)
                             {
                                 Ok(_) => (),

From 53030de69d34f9eab9a8a1161c4f3a63a79f7909 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 20:51:26 +0000
Subject: [PATCH 21/36] mark first uncovered DefineOpaqueTypes in
 compute_inherent_assoc_ty_args

---
 compiler/rustc_trait_selection/src/traits/project.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/compiler/rustc_trait_selection/src/traits/project.rs b/compiler/rustc_trait_selection/src/traits/project.rs
index 20aa3cec87335..d085bcc1f8eb1 100644
--- a/compiler/rustc_trait_selection/src/traits/project.rs
+++ b/compiler/rustc_trait_selection/src/traits/project.rs
@@ -1441,6 +1441,7 @@ pub fn compute_inherent_assoc_ty_args<'a, 'b, 'tcx>(
     // Infer the generic parameters of the impl by unifying the
     // impl type with the self type of the projection.
     let self_ty = alias_ty.self_ty();
+    // FIXME(DefineOpaqueTypes): no test exercizes using `DefineOpaqueTypes::Yes` below.
     match selcx.infcx.at(&cause, param_env).eq(DefineOpaqueTypes::No, impl_ty, self_ty) {
         Ok(mut ok) => obligations.append(&mut ok.obligations),
         Err(_) => {

From 1e39afdcc0b42e228f59a1c1dfd178aae9e8a0a8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 20:54:48 +0000
Subject: [PATCH 22/36] mark first uncovered DefineOpaqueTypes in
 confirm_param_env_candidate

---
 compiler/rustc_trait_selection/src/traits/project.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/compiler/rustc_trait_selection/src/traits/project.rs b/compiler/rustc_trait_selection/src/traits/project.rs
index d085bcc1f8eb1..2a41b957d54e7 100644
--- a/compiler/rustc_trait_selection/src/traits/project.rs
+++ b/compiler/rustc_trait_selection/src/traits/project.rs
@@ -2354,6 +2354,7 @@ fn confirm_param_env_candidate<'cx, 'tcx>(
 
     debug!(?cache_projection, ?obligation_projection);
 
+    // FIXME(DefineOpaqueTypes): no test exercizes using `DefineOpaqueTypes::Yes` below.
     match infcx.at(cause, param_env).eq(
         DefineOpaqueTypes::No,
         cache_projection,

From e4690120292ecdec40d5fab2a32c967a24511f25 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 20:59:46 +0000
Subject: [PATCH 23/36] mark first uncovered DefineOpaqueTypes in
 confirm_projection_candidate

---
 compiler/rustc_trait_selection/src/traits/select/confirmation.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
index 952184175f4dd..8ace554dca968 100644
--- a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
@@ -173,6 +173,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         );
 
         obligations.extend(self.infcx.commit_if_ok(|_| {
+            // FIXME(DefineOpaqueTypes): no test exercizes using `DefineOpaqueTypes::Yes` below.
             self.infcx
                 .at(&obligation.cause, obligation.param_env)
                 .sup(DefineOpaqueTypes::No, placeholder_trait_predicate, candidate)

From bc6de16b1d4cc2a16ba4256be2f1cc1bc2edacba Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 21:02:45 +0000
Subject: [PATCH 24/36] mark first uncovered DefineOpaqueTypes in
 confirm_object_candidate

---
 compiler/rustc_trait_selection/src/traits/select/confirmation.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
index 8ace554dca968..5175ddd76f434 100644
--- a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
@@ -512,6 +512,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         );
 
         nested.extend(self.infcx.commit_if_ok(|_| {
+            // FIXME(DefineOpaqueTypes): no test exercizes using `DefineOpaqueTypes::Yes` below.
             self.infcx
                 .at(&obligation.cause, obligation.param_env)
                 .sup(DefineOpaqueTypes::No, obligation_trait_ref, upcast_trait_ref)

From ad30b48529bb266ec98e20af987b27a43784e14a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 21:06:10 +0000
Subject: [PATCH 25/36] mark first uncovered DefineOpaqueTypes in
 confirm_builtin_unsize_candidate

---
 compiler/rustc_trait_selection/src/traits/select/confirmation.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
index 5175ddd76f434..0e1f0a0b1881b 100644
--- a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
@@ -1012,6 +1012,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
 
                 // Require that the traits involved in this upcast are **equal**;
                 // only the **lifetime bound** is changed.
+                // FIXME(DefineOpaqueTypes): no test exercizes using `DefineOpaqueTypes::Yes` below.
                 let InferOk { mut obligations, .. } = self
                     .infcx
                     .at(&obligation.cause, obligation.param_env)

From d1f9f8431b4388edb1ba761167010b26a8588b0a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 21:11:10 +0000
Subject: [PATCH 26/36] mark second uncovered DefineOpaqueTypes in
 confirm_builtin_unsize_candidate

---
 compiler/rustc_trait_selection/src/traits/select/confirmation.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
index 0e1f0a0b1881b..ebf169da69cbe 100644
--- a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
@@ -1081,6 +1081,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
 
             // `[T; n]` -> `[T]`
             (&ty::Array(a, _), &ty::Slice(b)) => {
+                // FIXME(DefineOpaqueTypes): no test exercizes using `DefineOpaqueTypes::Yes` below.
                 let InferOk { obligations, .. } = self
                     .infcx
                     .at(&obligation.cause, obligation.param_env)

From d21c0e8a36c9543a8e8a487add90716f4048060f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 21:12:23 +0000
Subject: [PATCH 27/36] mark third uncovered DefineOpaqueTypes in
 confirm_builtin_unsize_candidate

---
 compiler/rustc_trait_selection/src/traits/select/confirmation.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
index ebf169da69cbe..c5078a2ce79f6 100644
--- a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
@@ -1130,6 +1130,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                         if unsizing_params.contains(i as u32) { args_b[i] } else { k }
                     }));
                 let new_struct = Ty::new_adt(tcx, def, args);
+                // FIXME(DefineOpaqueTypes): no test exercizes using `DefineOpaqueTypes::Yes` below.
                 let InferOk { obligations, .. } = self
                     .infcx
                     .at(&obligation.cause, obligation.param_env)

From 2232f6ba0dae55b3bef4803c405af40bacaddc5e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 21:13:17 +0000
Subject: [PATCH 28/36] mark fourth uncovered DefineOpaqueTypes in
 confirm_builtin_unsize_candidate

---
 compiler/rustc_trait_selection/src/traits/select/confirmation.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
index c5078a2ce79f6..4383c53f61416 100644
--- a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
@@ -1164,6 +1164,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 // last element is equal to the target.
                 let new_tuple =
                     Ty::new_tup_from_iter(tcx, a_mid.iter().copied().chain(iter::once(b_last)));
+                // FIXME(DefineOpaqueTypes): no test exercizes using `DefineOpaqueTypes::Yes` below.
                 let InferOk { mut obligations, .. } = self
                     .infcx
                     .at(&obligation.cause, obligation.param_env)

From 846be8cab60dac3209f881075135f728202690b1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 21:26:09 +0000
Subject: [PATCH 29/36] mark first uncovered DefineOpaqueTypes in
 evaluate_predicate_recursively

---
 compiler/rustc_trait_selection/src/traits/select/mod.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs
index cf52e6726a17c..32cbbd4fa085f 100644
--- a/compiler/rustc_trait_selection/src/traits/select/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs
@@ -933,6 +933,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                             (Unevaluated(a), Unevaluated(b))
                                 if a.def == b.def && tcx.def_kind(a.def) == DefKind::AssocConst =>
                             {
+                                // FIXME(DefineOpaqueTypes): no test exercizes using
+                                // `DefineOpaqueTypes::Yes` below.
                                 if let Ok(InferOk { obligations, value: () }) = self
                                     .infcx
                                     .at(&obligation.cause, obligation.param_env)

From 8bb12337d746fb139d0327cb03a8380ac6b82bc5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 21:26:46 +0000
Subject: [PATCH 30/36] mark second uncovered DefineOpaqueTypes in
 evaluate_predicate_recursively

---
 compiler/rustc_trait_selection/src/traits/select/mod.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs
index 32cbbd4fa085f..41571a52b1097 100644
--- a/compiler/rustc_trait_selection/src/traits/select/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs
@@ -949,6 +949,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                             }
                             (_, Unevaluated(_)) | (Unevaluated(_), _) => (),
                             (_, _) => {
+                                // FIXME(DefineOpaqueTypes): no test exercizes using
+                                // `DefineOpaqueTypes::Yes` below.
                                 if let Ok(InferOk { obligations, value: () }) = self
                                     .infcx
                                     .at(&obligation.cause, obligation.param_env)

From 1f474bf3dc91a2b2030da75c12af6365ca1e4de9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 21:27:56 +0000
Subject: [PATCH 31/36] mark third uncovered DefineOpaqueTypes in
 evaluate_predicate_recursively

---
 compiler/rustc_trait_selection/src/traits/select/mod.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs
index 41571a52b1097..6c6964d2aa366 100644
--- a/compiler/rustc_trait_selection/src/traits/select/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs
@@ -983,6 +983,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
 
                     match (evaluate(c1), evaluate(c2)) {
                         (Ok(c1), Ok(c2)) => {
+                            // FIXME(DefineOpaqueTypes): no test exercizes using
+                            // `DefineOpaqueTypes::Yes` below.
                             match self.infcx.at(&obligation.cause, obligation.param_env).eq(
                                 DefineOpaqueTypes::No,
                                 c1,

From 48c5a069b8fbb5bdd4c75c5ed172ec260358eb93 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 21:28:37 +0000
Subject: [PATCH 32/36] mark fourth uncovered DefineOpaqueTypes in
 evaluate_predicate_recursively

---
 compiler/rustc_trait_selection/src/traits/select/mod.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs
index 6c6964d2aa366..c3702726e11f5 100644
--- a/compiler/rustc_trait_selection/src/traits/select/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs
@@ -1015,6 +1015,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 }
                 ty::PredicateKind::Ambiguous => Ok(EvaluatedToAmbig),
                 ty::PredicateKind::Clause(ty::ClauseKind::ConstArgHasType(ct, ty)) => {
+                    // FIXME(DefineOpaqueTypes): no test exercizes using `DefineOpaqueTypes::Yes`
+                    // below.
                     match self.infcx.at(&obligation.cause, obligation.param_env).eq(
                         DefineOpaqueTypes::No,
                         ct.ty(),

From 278ba7aec44fc32659f91653d6fbff251a7163d8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 21:29:30 +0000
Subject: [PATCH 33/36] mark first uncovered DefineOpaqueTypes in
 match_normalize_trait_ref

---
 compiler/rustc_trait_selection/src/traits/select/mod.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs
index c3702726e11f5..fb3b0033ce682 100644
--- a/compiler/rustc_trait_selection/src/traits/select/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs
@@ -1716,6 +1716,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 trait_bound,
             )
         });
+        // FIXME(DefineOpaqueTypes): no test exercizes using `DefineOpaqueTypes::Yes` below.
         self.infcx
             .at(&obligation.cause, obligation.param_env)
             .sup(DefineOpaqueTypes::No, ty::Binder::dummy(placeholder_trait_ref), trait_bound)

From a9b5f662a95d308ecff46042944e646195fa5797 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 21:30:07 +0000
Subject: [PATCH 34/36] mark first uncovered DefineOpaqueTypes in
 match_upcast_principal

---
 compiler/rustc_trait_selection/src/traits/select/mod.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs
index fb3b0033ce682..39b380e8e155a 100644
--- a/compiler/rustc_trait_selection/src/traits/select/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs
@@ -2539,6 +2539,8 @@ impl<'tcx> SelectionContext<'_, 'tcx> {
                 // Check that a_ty's supertrait (upcast_principal) is compatible
                 // with the target (b_ty).
                 ty::ExistentialPredicate::Trait(target_principal) => {
+                    // FIXME(DefineOpaqueTypes): no test exercizes using `DefineOpaqueTypes::Yes`
+                    // below.
                     nested.extend(
                         self.infcx
                             .at(&obligation.cause, obligation.param_env)

From d6fa5d9537fafd39dea1cb2c29a41adb5b7e3fb4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 21:30:50 +0000
Subject: [PATCH 35/36] mark second uncovered DefineOpaqueTypes in
 match_upcast_principal

---
 compiler/rustc_trait_selection/src/traits/select/mod.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs
index 39b380e8e155a..18d5b2972f681 100644
--- a/compiler/rustc_trait_selection/src/traits/select/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs
@@ -2579,6 +2579,8 @@ impl<'tcx> SelectionContext<'_, 'tcx> {
                     if matching_projections.next().is_some() {
                         return Ok(None);
                     }
+                    // FIXME(DefineOpaqueTypes): no test exercizes using `DefineOpaqueTypes::Yes`
+                    // below.
                     nested.extend(
                         self.infcx
                             .at(&obligation.cause, obligation.param_env)

From b82ba573178ff12e2fcbe8eedc0f4da4afab31d1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sun, 29 Oct 2023 21:35:17 +0000
Subject: [PATCH 36/36] mark first uncovered DefineOpaqueTypes in
 fulfill_implication

---
 compiler/rustc_trait_selection/src/traits/specialize/mod.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/compiler/rustc_trait_selection/src/traits/specialize/mod.rs b/compiler/rustc_trait_selection/src/traits/specialize/mod.rs
index efab29743f4e9..c0ed3a1579fb7 100644
--- a/compiler/rustc_trait_selection/src/traits/specialize/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/specialize/mod.rs
@@ -221,6 +221,7 @@ fn fulfill_implication<'tcx>(
         util::impl_subject_and_oblig(selcx, param_env, target_impl, target_args, error_cause);
 
     // do the impls unify? If not, no specialization.
+    // FIXME(DefineOpaqueTypes): no test exercizes using `DefineOpaqueTypes::Yes` below.
     let Ok(InferOk { obligations: more_obligations, .. }) = infcx
         .at(&ObligationCause::dummy(), param_env)
         .eq(DefineOpaqueTypes::No, source_trait, target_trait)