From 4be041a2cd9f134ee42579beb14840b9abebcb75 Mon Sep 17 00:00:00 2001
From: Zachary S <zasample18+github@gmail.com>
Date: Wed, 15 May 2024 10:00:42 -0500
Subject: [PATCH 01/21] Also apply `warn(for_loops_over_fallibles)` to &T and
 &mut T, not just T = Result/Option.

---
 compiler/rustc_lint/src/for_loops_over_fallibles.rs | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/compiler/rustc_lint/src/for_loops_over_fallibles.rs b/compiler/rustc_lint/src/for_loops_over_fallibles.rs
index a6876d8aae793..d766393db29a5 100644
--- a/compiler/rustc_lint/src/for_loops_over_fallibles.rs
+++ b/compiler/rustc_lint/src/for_loops_over_fallibles.rs
@@ -52,7 +52,15 @@ impl<'tcx> LateLintPass<'tcx> for ForLoopsOverFallibles {
 
         let ty = cx.typeck_results().expr_ty(arg);
 
-        let &ty::Adt(adt, args) = ty.kind() else { return };
+        // let &ty::Adt(adt, args) = ty.kind() else { return };
+        let (adt, args, _) = match ty.kind() {
+            &ty::Adt(adt, args) => (adt, args, None),
+            &ty::Ref(_, ty, mutability) => match ty.kind() {
+                &ty::Adt(adt, args) => (adt, args, Some(mutability)),
+                _ => return,
+            },
+            _ => return,
+        };
 
         let (article, ty, var) = match adt.did() {
             did if cx.tcx.is_diagnostic_item(sym::Option, did) => ("an", "Option", "Some"),

From 7d7eb973d0118a52209e5ee7adafc29b341957f0 Mon Sep 17 00:00:00 2001
From: Zachary S <zasample18+github@gmail.com>
Date: Wed, 15 May 2024 10:01:06 -0500
Subject: [PATCH 02/21] Fix new for_loops_over_fallibles hits in compiler.

---
 compiler/rustc_builtin_macros/src/deriving/default.rs | 4 ++--
 compiler/rustc_resolve/src/late.rs                    | 8 ++++----
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/compiler/rustc_builtin_macros/src/deriving/default.rs b/compiler/rustc_builtin_macros/src/deriving/default.rs
index bf92ddb33701c..577523a1d5a32 100644
--- a/compiler/rustc_builtin_macros/src/deriving/default.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/default.rs
@@ -3,7 +3,7 @@ use crate::deriving::generic::*;
 use crate::errors;
 use core::ops::ControlFlow;
 use rustc_ast as ast;
-use rustc_ast::visit::walk_list;
+use rustc_ast::visit::visit_opt;
 use rustc_ast::{attr, EnumDef, VariantData};
 use rustc_expand::base::{Annotatable, DummyResult, ExtCtxt};
 use rustc_span::symbol::Ident;
@@ -224,7 +224,7 @@ impl<'a, 'b> rustc_ast::visit::Visitor<'a> for DetectNonVariantDefaultAttr<'a, '
         self.visit_ident(v.ident);
         self.visit_vis(&v.vis);
         self.visit_variant_data(&v.data);
-        walk_list!(self, visit_anon_const, &v.disr_expr);
+        visit_opt!(self, visit_anon_const, &v.disr_expr);
         for attr in &v.attrs {
             rustc_ast::visit::walk_attribute(self, attr);
         }
diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs
index 322f2922f9253..796e3e38aebfb 100644
--- a/compiler/rustc_resolve/src/late.rs
+++ b/compiler/rustc_resolve/src/late.rs
@@ -12,7 +12,7 @@ use crate::{Module, ModuleOrUniformRoot, NameBinding, ParentScope, PathResult};
 use crate::{ResolutionError, Resolver, Segment, UseError};
 
 use rustc_ast::ptr::P;
-use rustc_ast::visit::{walk_list, AssocCtxt, BoundKind, FnCtxt, FnKind, Visitor};
+use rustc_ast::visit::{visit_opt, walk_list, AssocCtxt, BoundKind, FnCtxt, FnKind, Visitor};
 use rustc_ast::*;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap};
 use rustc_errors::{codes::*, Applicability, DiagArgValue, IntoDiagArg, StashKey};
@@ -3286,7 +3286,7 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
     fn resolve_local(&mut self, local: &'ast Local) {
         debug!("resolving local ({:?})", local);
         // Resolve the type.
-        walk_list!(self, visit_ty, &local.ty);
+        visit_opt!(self, visit_ty, &local.ty);
 
         // Resolve the initializer.
         if let Some((init, els)) = local.kind.init_else_opt() {
@@ -3485,8 +3485,8 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
     fn resolve_arm(&mut self, arm: &'ast Arm) {
         self.with_rib(ValueNS, RibKind::Normal, |this| {
             this.resolve_pattern_top(&arm.pat, PatternSource::Match);
-            walk_list!(this, visit_expr, &arm.guard);
-            walk_list!(this, visit_expr, &arm.body);
+            visit_opt!(this, visit_expr, &arm.guard);
+            visit_opt!(this, visit_expr, &arm.body);
         });
     }
 

From 77f288c18d638f3cfda91810e0c4fb6a6c7e6963 Mon Sep 17 00:00:00 2001
From: Zachary S <zasample18+github@gmail.com>
Date: Wed, 15 May 2024 10:59:13 -0500
Subject: [PATCH 03/21] Include reference in lint diagnostic

---
 compiler/rustc_lint/messages.ftl                    |  2 +-
 compiler/rustc_lint/src/for_loops_over_fallibles.rs | 10 +++++++---
 compiler/rustc_lint/src/lints.rs                    |  1 +
 3 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/compiler/rustc_lint/messages.ftl b/compiler/rustc_lint/messages.ftl
index 5180fce2eb378..8c9ad5b6c6b7a 100644
--- a/compiler/rustc_lint/messages.ftl
+++ b/compiler/rustc_lint/messages.ftl
@@ -215,7 +215,7 @@ lint_expectation = this lint expectation is unfulfilled
     .rationale = {$rationale}
 
 lint_for_loops_over_fallibles =
-    for loop over {$article} `{$ty}`. This is more readably written as an `if let` statement
+    for loop over {$article} `{$ref_prefix}{$ty}`. This is more readably written as an `if let` statement
     .suggestion = consider using `if let` to clear intent
     .remove_next = to iterate over `{$recv_snip}` remove the call to `next`
     .use_while_let = to check pattern in a loop use `while let`
diff --git a/compiler/rustc_lint/src/for_loops_over_fallibles.rs b/compiler/rustc_lint/src/for_loops_over_fallibles.rs
index d766393db29a5..12a790bb0faf5 100644
--- a/compiler/rustc_lint/src/for_loops_over_fallibles.rs
+++ b/compiler/rustc_lint/src/for_loops_over_fallibles.rs
@@ -52,8 +52,7 @@ impl<'tcx> LateLintPass<'tcx> for ForLoopsOverFallibles {
 
         let ty = cx.typeck_results().expr_ty(arg);
 
-        // let &ty::Adt(adt, args) = ty.kind() else { return };
-        let (adt, args, _) = match ty.kind() {
+        let (adt, args, ref_mutability) = match ty.kind() {
             &ty::Adt(adt, args) => (adt, args, None),
             &ty::Ref(_, ty, mutability) => match ty.kind() {
                 &ty::Adt(adt, args) => (adt, args, Some(mutability)),
@@ -68,6 +67,11 @@ impl<'tcx> LateLintPass<'tcx> for ForLoopsOverFallibles {
             _ => return,
         };
 
+        let ref_prefix = match ref_mutability {
+            None => "",
+            Some(ref_mutability) => ref_mutability.ref_prefix_str(),
+        };
+
         let sub = if let Some(recv) = extract_iterator_next_call(cx, arg)
             && let Ok(recv_snip) = cx.sess().source_map().span_to_snippet(recv.span)
         {
@@ -93,7 +97,7 @@ impl<'tcx> LateLintPass<'tcx> for ForLoopsOverFallibles {
         cx.emit_span_lint(
             FOR_LOOPS_OVER_FALLIBLES,
             arg.span,
-            ForLoopsOverFalliblesDiag { article, ty, sub, question_mark, suggestion },
+            ForLoopsOverFalliblesDiag { article, ref_prefix, ty, sub, question_mark, suggestion },
         );
     }
 }
diff --git a/compiler/rustc_lint/src/lints.rs b/compiler/rustc_lint/src/lints.rs
index 7efa5245baa20..382532b17880a 100644
--- a/compiler/rustc_lint/src/lints.rs
+++ b/compiler/rustc_lint/src/lints.rs
@@ -613,6 +613,7 @@ pub enum PtrNullChecksDiag<'a> {
 #[diag(lint_for_loops_over_fallibles)]
 pub struct ForLoopsOverFalliblesDiag<'a> {
     pub article: &'static str,
+    pub ref_prefix: &'static str,
     pub ty: &'static str,
     #[subdiagnostic]
     pub sub: ForLoopsOverFalliblesLoopSub<'a>,

From ea549fd1761c8f1fbc99df2ad7d3c1ac7d8f7824 Mon Sep 17 00:00:00 2001
From: Zachary S <zasample18+github@gmail.com>
Date: Wed, 15 May 2024 11:53:40 -0500
Subject: [PATCH 04/21] Add tests for 'Also apply
 `warn(for_loops_over_fallibles)` to &T and &mut T, not just T =
 Result/Option.'

---
 tests/ui/lint/for_loop_over_fallibles.rs     | 22 +++++++
 tests/ui/lint/for_loop_over_fallibles.stderr | 62 +++++++++++++++++++-
 2 files changed, 83 insertions(+), 1 deletion(-)

diff --git a/tests/ui/lint/for_loop_over_fallibles.rs b/tests/ui/lint/for_loop_over_fallibles.rs
index 52c3b8f2aae5f..76049453126b2 100644
--- a/tests/ui/lint/for_loop_over_fallibles.rs
+++ b/tests/ui/lint/for_loop_over_fallibles.rs
@@ -41,3 +41,25 @@ fn _returns_result() -> Result<(), ()> {
 
     Ok(())
 }
+
+fn _by_ref() {
+    // Shared refs
+    for _ in &Some(1) {}
+    //~^ WARN for loop over an `&Option`. This is more readably written as an `if let` statement
+    //~| HELP to check pattern in a loop use `while let`
+    //~| HELP consider using `if let` to clear intent
+    for _ in &Ok::<_, ()>(1) {}
+    //~^ WARN for loop over a `&Result`. This is more readably written as an `if let` statement
+    //~| HELP to check pattern in a loop use `while let`
+    //~| HELP consider using `if let` to clear intent
+
+    // Mutable refs
+    for _ in &mut Some(1) {}
+    //~^ WARN for loop over an `&mut Option`. This is more readably written as an `if let` statement
+    //~| HELP to check pattern in a loop use `while let`
+    //~| HELP consider using `if let` to clear intent
+    for _ in &mut Ok::<_, ()>(1) {}
+    //~^ WARN for loop over a `&mut Result`. This is more readably written as an `if let` statement
+    //~| HELP to check pattern in a loop use `while let`
+    //~| HELP consider using `if let` to clear intent
+}
diff --git a/tests/ui/lint/for_loop_over_fallibles.stderr b/tests/ui/lint/for_loop_over_fallibles.stderr
index 96efdf85c4901..00134e468ba65 100644
--- a/tests/ui/lint/for_loop_over_fallibles.stderr
+++ b/tests/ui/lint/for_loop_over_fallibles.stderr
@@ -97,5 +97,65 @@ help: consider using `if let` to clear intent
 LL |     if let Ok(_) = Ok::<_, ()>([0; 0]) {}
    |     ~~~~~~~~~~ ~~~
 
-warning: 6 warnings emitted
+warning: for loop over an `&Option`. This is more readably written as an `if let` statement
+  --> $DIR/for_loop_over_fallibles.rs:47:14
+   |
+LL |     for _ in &Some(1) {}
+   |              ^^^^^^^^
+   |
+help: to check pattern in a loop use `while let`
+   |
+LL |     while let Some(_) = &Some(1) {}
+   |     ~~~~~~~~~~~~~~~ ~~~
+help: consider using `if let` to clear intent
+   |
+LL |     if let Some(_) = &Some(1) {}
+   |     ~~~~~~~~~~~~ ~~~
+
+warning: for loop over a `&Result`. This is more readably written as an `if let` statement
+  --> $DIR/for_loop_over_fallibles.rs:51:14
+   |
+LL |     for _ in &Ok::<_, ()>(1) {}
+   |              ^^^^^^^^^^^^^^^
+   |
+help: to check pattern in a loop use `while let`
+   |
+LL |     while let Ok(_) = &Ok::<_, ()>(1) {}
+   |     ~~~~~~~~~~~~~ ~~~
+help: consider using `if let` to clear intent
+   |
+LL |     if let Ok(_) = &Ok::<_, ()>(1) {}
+   |     ~~~~~~~~~~ ~~~
+
+warning: for loop over an `&mut Option`. This is more readably written as an `if let` statement
+  --> $DIR/for_loop_over_fallibles.rs:57:14
+   |
+LL |     for _ in &mut Some(1) {}
+   |              ^^^^^^^^^^^^
+   |
+help: to check pattern in a loop use `while let`
+   |
+LL |     while let Some(_) = &mut Some(1) {}
+   |     ~~~~~~~~~~~~~~~ ~~~
+help: consider using `if let` to clear intent
+   |
+LL |     if let Some(_) = &mut Some(1) {}
+   |     ~~~~~~~~~~~~ ~~~
+
+warning: for loop over a `&mut Result`. This is more readably written as an `if let` statement
+  --> $DIR/for_loop_over_fallibles.rs:61:14
+   |
+LL |     for _ in &mut Ok::<_, ()>(1) {}
+   |              ^^^^^^^^^^^^^^^^^^^
+   |
+help: to check pattern in a loop use `while let`
+   |
+LL |     while let Ok(_) = &mut Ok::<_, ()>(1) {}
+   |     ~~~~~~~~~~~~~ ~~~
+help: consider using `if let` to clear intent
+   |
+LL |     if let Ok(_) = &mut Ok::<_, ()>(1) {}
+   |     ~~~~~~~~~~ ~~~
+
+warning: 10 warnings emitted
 

From 0e467596ffa85c68504b94b951a0c32fefb3c889 Mon Sep 17 00:00:00 2001
From: Zachary S <zasample18+github@gmail.com>
Date: Wed, 15 May 2024 12:17:25 -0500
Subject: [PATCH 05/21] Fix more new for_loops_over_fallibles hits in compiler.

---
 compiler/rustc_hir_analysis/src/check/region.rs   | 4 ++--
 compiler/rustc_mir_build/src/build/matches/mod.rs | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/compiler/rustc_hir_analysis/src/check/region.rs b/compiler/rustc_hir_analysis/src/check/region.rs
index 4540310937d02..e51f95eed021b 100644
--- a/compiler/rustc_hir_analysis/src/check/region.rs
+++ b/compiler/rustc_hir_analysis/src/check/region.rs
@@ -6,7 +6,7 @@
 //!
 //! [rustc dev guide]: https://rustc-dev-guide.rust-lang.org/borrow_check.html
 
-use rustc_ast::visit::walk_list;
+use rustc_ast::visit::visit_opt;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
@@ -168,7 +168,7 @@ fn resolve_block<'tcx>(visitor: &mut RegionResolutionVisitor<'tcx>, blk: &'tcx h
                 hir::StmtKind::Expr(..) | hir::StmtKind::Semi(..) => visitor.visit_stmt(statement),
             }
         }
-        walk_list!(visitor, visit_expr, &blk.expr);
+        visit_opt!(visitor, visit_expr, &blk.expr);
     }
 
     visitor.cx = prev_cx;
diff --git a/compiler/rustc_mir_build/src/build/matches/mod.rs b/compiler/rustc_mir_build/src/build/matches/mod.rs
index 3fc719394bf9e..d948354bc4959 100644
--- a/compiler/rustc_mir_build/src/build/matches/mod.rs
+++ b/compiler/rustc_mir_build/src/build/matches/mod.rs
@@ -925,7 +925,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                 for subpattern in prefix.iter() {
                     self.visit_primary_bindings(subpattern, pattern_user_ty.clone().index(), f);
                 }
-                for subpattern in slice {
+                if let Some(subpattern) = slice {
                     self.visit_primary_bindings(
                         subpattern,
                         pattern_user_ty.clone().subslice(from, to),

From 66573b70a9b1807337f1980538d524e1dfd2aba1 Mon Sep 17 00:00:00 2001
From: Zachary S <zasample18+github@gmail.com>
Date: Wed, 15 May 2024 12:45:52 -0500
Subject: [PATCH 06/21] Use 'a' article for &Option.

---
 compiler/rustc_lint/src/for_loops_over_fallibles.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/compiler/rustc_lint/src/for_loops_over_fallibles.rs b/compiler/rustc_lint/src/for_loops_over_fallibles.rs
index 12a790bb0faf5..b05f5e7638b4e 100644
--- a/compiler/rustc_lint/src/for_loops_over_fallibles.rs
+++ b/compiler/rustc_lint/src/for_loops_over_fallibles.rs
@@ -62,6 +62,7 @@ impl<'tcx> LateLintPass<'tcx> for ForLoopsOverFallibles {
         };
 
         let (article, ty, var) = match adt.did() {
+            did if cx.tcx.is_diagnostic_item(sym::Option, did) && ref_mutability.is_some() => ("a", "Option", "Some"),
             did if cx.tcx.is_diagnostic_item(sym::Option, did) => ("an", "Option", "Some"),
             did if cx.tcx.is_diagnostic_item(sym::Result, did) => ("a", "Result", "Ok"),
             _ => return,

From 6b818ddac61e9771e3b97f17d8ab21cf9f7bc2de Mon Sep 17 00:00:00 2001
From: Zachary S <zasample18+github@gmail.com>
Date: Wed, 15 May 2024 13:15:59 -0500
Subject: [PATCH 07/21] Fix article in test

---
 tests/ui/lint/for_loop_over_fallibles.rs     | 4 ++--
 tests/ui/lint/for_loop_over_fallibles.stderr | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/tests/ui/lint/for_loop_over_fallibles.rs b/tests/ui/lint/for_loop_over_fallibles.rs
index 76049453126b2..89ac20c352178 100644
--- a/tests/ui/lint/for_loop_over_fallibles.rs
+++ b/tests/ui/lint/for_loop_over_fallibles.rs
@@ -45,7 +45,7 @@ fn _returns_result() -> Result<(), ()> {
 fn _by_ref() {
     // Shared refs
     for _ in &Some(1) {}
-    //~^ WARN for loop over an `&Option`. This is more readably written as an `if let` statement
+    //~^ WARN for loop over a `&Option`. This is more readably written as an `if let` statement
     //~| HELP to check pattern in a loop use `while let`
     //~| HELP consider using `if let` to clear intent
     for _ in &Ok::<_, ()>(1) {}
@@ -55,7 +55,7 @@ fn _by_ref() {
 
     // Mutable refs
     for _ in &mut Some(1) {}
-    //~^ WARN for loop over an `&mut Option`. This is more readably written as an `if let` statement
+    //~^ WARN for loop over a `&mut Option`. This is more readably written as an `if let` statement
     //~| HELP to check pattern in a loop use `while let`
     //~| HELP consider using `if let` to clear intent
     for _ in &mut Ok::<_, ()>(1) {}
diff --git a/tests/ui/lint/for_loop_over_fallibles.stderr b/tests/ui/lint/for_loop_over_fallibles.stderr
index 00134e468ba65..f695de082572a 100644
--- a/tests/ui/lint/for_loop_over_fallibles.stderr
+++ b/tests/ui/lint/for_loop_over_fallibles.stderr
@@ -97,7 +97,7 @@ help: consider using `if let` to clear intent
 LL |     if let Ok(_) = Ok::<_, ()>([0; 0]) {}
    |     ~~~~~~~~~~ ~~~
 
-warning: for loop over an `&Option`. This is more readably written as an `if let` statement
+warning: for loop over a `&Option`. This is more readably written as an `if let` statement
   --> $DIR/for_loop_over_fallibles.rs:47:14
    |
 LL |     for _ in &Some(1) {}
@@ -127,7 +127,7 @@ help: consider using `if let` to clear intent
 LL |     if let Ok(_) = &Ok::<_, ()>(1) {}
    |     ~~~~~~~~~~ ~~~
 
-warning: for loop over an `&mut Option`. This is more readably written as an `if let` statement
+warning: for loop over a `&mut Option`. This is more readably written as an `if let` statement
   --> $DIR/for_loop_over_fallibles.rs:57:14
    |
 LL |     for _ in &mut Some(1) {}

From 376a8c0ae5ad6cb8d0c5d6631874bdd3c950436f Mon Sep 17 00:00:00 2001
From: Zachary S <zasample18+github@gmail.com>
Date: Wed, 15 May 2024 13:51:16 -0500
Subject: [PATCH 08/21] Allow for_loops_over_fallibles in test that tests &mut
 Result as IntoIterator.

---
 library/core/tests/result.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/library/core/tests/result.rs b/library/core/tests/result.rs
index a47ef7aa1ebc6..00a6fd75b4f46 100644
--- a/library/core/tests/result.rs
+++ b/library/core/tests/result.rs
@@ -170,6 +170,7 @@ pub fn test_iter() {
 }
 
 #[test]
+#[allow(for_loops_over_fallibles)]
 pub fn test_iter_mut() {
     let mut ok: Result<isize, &'static str> = Ok(100);
     for loc in ok.iter_mut() {

From a59d071e9caa140ddaff4a9e1b747dba0d95f0cd Mon Sep 17 00:00:00 2001
From: zachs18 <8355914+zachs18@users.noreply.github.com>
Date: Thu, 16 May 2024 05:51:29 +0000
Subject: [PATCH 09/21] Fix `for_loops_over_fallibles` hits in
 compiletest/src/json.rs

---
 src/tools/compiletest/src/json.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/tools/compiletest/src/json.rs b/src/tools/compiletest/src/json.rs
index 10726b9842080..29e8809e5bd66 100644
--- a/src/tools/compiletest/src/json.rs
+++ b/src/tools/compiletest/src/json.rs
@@ -282,7 +282,7 @@ fn push_expected_errors(
 
     // Add notes for the backtrace
     for span in primary_spans {
-        for frame in &span.expansion {
+        if let Some(frame) = &span.expansion {
             push_backtrace(expected_errors, frame, file_name);
         }
     }
@@ -315,7 +315,7 @@ fn push_backtrace(
         });
     }
 
-    for previous_expansion in &expansion.span.expansion {
+    if let Some(previous_expansion) = &expansion.span.expansion {
         push_backtrace(expected_errors, previous_expansion, file_name);
     }
 }

From 3a21fb5cec07052cb664b6a051e233cd4776283a Mon Sep 17 00:00:00 2001
From: Jubilee Young <workingjubilee@gmail.com>
Date: Tue, 21 May 2024 18:55:12 -0700
Subject: [PATCH 10/21] Wrap Context.ext in AssertUnwindSafe

---
 library/core/src/task/wake.rs                 | 11 +++--
 tests/ui/async-await/async-is-unwindsafe.rs   |  1 -
 .../ui/async-await/async-is-unwindsafe.stderr | 43 +++----------------
 .../context-is-sorta-unwindsafe.rs            | 14 ++++++
 4 files changed, 27 insertions(+), 42 deletions(-)
 create mode 100644 tests/ui/async-await/context-is-sorta-unwindsafe.rs

diff --git a/library/core/src/task/wake.rs b/library/core/src/task/wake.rs
index 7691721b91e21..3d21b09fa8a02 100644
--- a/library/core/src/task/wake.rs
+++ b/library/core/src/task/wake.rs
@@ -5,6 +5,7 @@ use crate::mem::transmute;
 use crate::any::Any;
 use crate::fmt;
 use crate::marker::PhantomData;
+use crate::panic::AssertUnwindSafe;
 use crate::ptr;
 
 /// A `RawWaker` allows the implementor of a task executor to create a [`Waker`]
@@ -236,7 +237,7 @@ enum ExtData<'a> {
 pub struct Context<'a> {
     waker: &'a Waker,
     local_waker: &'a LocalWaker,
-    ext: ExtData<'a>,
+    ext: AssertUnwindSafe<ExtData<'a>>,
     // Ensure we future-proof against variance changes by forcing
     // the lifetime to be invariant (argument-position lifetimes
     // are contravariant while return-position lifetimes are
@@ -279,7 +280,9 @@ impl<'a> Context<'a> {
     #[unstable(feature = "context_ext", issue = "123392")]
     #[rustc_const_unstable(feature = "const_waker", issue = "102012")]
     pub const fn ext(&mut self) -> &mut dyn Any {
-        match &mut self.ext {
+        // FIXME: this field makes Context extra-weird about unwind safety
+        // can we justify AssertUnwindSafe if we stabilize this? do we care?
+        match &mut *self.ext {
             ExtData::Some(data) => *data,
             ExtData::None(unit) => unit,
         }
@@ -353,7 +356,7 @@ impl<'a> ContextBuilder<'a> {
     #[rustc_const_unstable(feature = "const_waker", issue = "102012")]
     #[unstable(feature = "context_ext", issue = "123392")]
     pub const fn from(cx: &'a mut Context<'_>) -> Self {
-        let ext = match &mut cx.ext {
+        let ext = match &mut *cx.ext {
             ExtData::Some(ext) => ExtData::Some(*ext),
             ExtData::None(()) => ExtData::None(()),
         };
@@ -396,7 +399,7 @@ impl<'a> ContextBuilder<'a> {
     #[rustc_const_unstable(feature = "const_waker", issue = "102012")]
     pub const fn build(self) -> Context<'a> {
         let ContextBuilder { waker, local_waker, ext, _marker, _marker2 } = self;
-        Context { waker, local_waker, ext, _marker, _marker2 }
+        Context { waker, local_waker, ext: AssertUnwindSafe(ext), _marker, _marker2 }
     }
 }
 
diff --git a/tests/ui/async-await/async-is-unwindsafe.rs b/tests/ui/async-await/async-is-unwindsafe.rs
index d0202f72f0086..53009b6e7410f 100644
--- a/tests/ui/async-await/async-is-unwindsafe.rs
+++ b/tests/ui/async-await/async-is-unwindsafe.rs
@@ -11,7 +11,6 @@ fn main() {
 
     is_unwindsafe(async {
         //~^ ERROR the type `&mut Context<'_>` may not be safely transferred across an unwind boundary
-        //~| ERROR the type `&mut (dyn Any + 'static)` may not be safely transferred across an unwind boundary
         use std::ptr::null;
         use std::task::{Context, RawWaker, RawWakerVTable, Waker};
         let waker = unsafe {
diff --git a/tests/ui/async-await/async-is-unwindsafe.stderr b/tests/ui/async-await/async-is-unwindsafe.stderr
index 6bb06df9f39e9..5d87fc747682a 100644
--- a/tests/ui/async-await/async-is-unwindsafe.stderr
+++ b/tests/ui/async-await/async-is-unwindsafe.stderr
@@ -6,18 +6,19 @@ LL |        is_unwindsafe(async {
    |  |_____|
    | ||
 LL | ||
-LL | ||
 LL | ||         use std::ptr::null;
+LL | ||         use std::task::{Context, RawWaker, RawWakerVTable, Waker};
 ...  ||
 LL | ||         drop(cx_ref);
 LL | ||     });
    | ||_____-^ `&mut Context<'_>` may not be safely transferred across an unwind boundary
    |  |_____|
-   |        within this `{async block@$DIR/async-is-unwindsafe.rs:12:19: 30:6}`
+   |        within this `{async block@$DIR/async-is-unwindsafe.rs:12:19: 29:6}`
    |
-   = help: within `{async block@$DIR/async-is-unwindsafe.rs:12:19: 30:6}`, the trait `UnwindSafe` is not implemented for `&mut Context<'_>`, which is required by `{async block@$DIR/async-is-unwindsafe.rs:12:19: 30:6}: UnwindSafe`
+   = help: within `{async block@$DIR/async-is-unwindsafe.rs:12:19: 29:6}`, the trait `UnwindSafe` is not implemented for `&mut Context<'_>`, which is required by `{async block@$DIR/async-is-unwindsafe.rs:12:19: 29:6}: UnwindSafe`
+   = note: `UnwindSafe` is implemented for `&Context<'_>`, but not for `&mut Context<'_>`
 note: future does not implement `UnwindSafe` as this value is used across an await
-  --> $DIR/async-is-unwindsafe.rs:26:18
+  --> $DIR/async-is-unwindsafe.rs:25:18
    |
 LL |         let cx_ref = &mut cx;
    |             ------ has type `&mut Context<'_>` which does not implement `UnwindSafe`
@@ -30,38 +31,6 @@ note: required by a bound in `is_unwindsafe`
 LL | fn is_unwindsafe(_: impl std::panic::UnwindSafe) {}
    |                          ^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `is_unwindsafe`
 
-error[E0277]: the type `&mut (dyn Any + 'static)` may not be safely transferred across an unwind boundary
-  --> $DIR/async-is-unwindsafe.rs:12:5
-   |
-LL |        is_unwindsafe(async {
-   |   _____^_____________-
-   |  |_____|
-   | ||
-LL | ||
-LL | ||
-LL | ||         use std::ptr::null;
-...  ||
-LL | ||         drop(cx_ref);
-LL | ||     });
-   | ||_____-^ `&mut (dyn Any + 'static)` may not be safely transferred across an unwind boundary
-   |  |_____|
-   |        within this `{async block@$DIR/async-is-unwindsafe.rs:12:19: 30:6}`
-   |
-   = help: within `{async block@$DIR/async-is-unwindsafe.rs:12:19: 30:6}`, the trait `UnwindSafe` is not implemented for `&mut (dyn Any + 'static)`, which is required by `{async block@$DIR/async-is-unwindsafe.rs:12:19: 30:6}: UnwindSafe`
-note: future does not implement `UnwindSafe` as this value is used across an await
-  --> $DIR/async-is-unwindsafe.rs:26:18
-   |
-LL |         let mut cx = Context::from_waker(&waker);
-   |             ------ has type `Context<'_>` which does not implement `UnwindSafe`
-...
-LL |         async {}.await; // this needs an inner await point
-   |                  ^^^^^ await occurs here, with `mut cx` maybe used later
-note: required by a bound in `is_unwindsafe`
-  --> $DIR/async-is-unwindsafe.rs:3:26
-   |
-LL | fn is_unwindsafe(_: impl std::panic::UnwindSafe) {}
-   |                          ^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `is_unwindsafe`
-
-error: aborting due to 2 previous errors
+error: aborting due to 1 previous error
 
 For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/async-await/context-is-sorta-unwindsafe.rs b/tests/ui/async-await/context-is-sorta-unwindsafe.rs
new file mode 100644
index 0000000000000..278476ea2379c
--- /dev/null
+++ b/tests/ui/async-await/context-is-sorta-unwindsafe.rs
@@ -0,0 +1,14 @@
+//@ run-pass
+// Tests against a regression surfaced by crater in https://github.com/rust-lang/rust/issues/125193
+// Unwind Safety is not a very coherent concept, but we'd prefer no regressions until we kibosh it
+// and this is an unstable feature anyways sooo...
+
+use std::panic::UnwindSafe;
+use std::task::Context;
+
+fn unwind_safe<T: UnwindSafe>() {}
+
+fn main() {
+    unwind_safe::<Context<'_>>(); // test UnwindSafe
+    unwind_safe::<&Context<'_>>(); // test RefUnwindSafe
+}

From 8fde7e3b64109f5ebfadef4a015e2cb055bed08c Mon Sep 17 00:00:00 2001
From: surechen <chenshuo17@huawei.com>
Date: Mon, 8 Apr 2024 16:19:09 +0800
Subject: [PATCH 11/21] For OutsideLoop we should not suggest add 'block label
 in if block, or we wiil get another err: block label not supported here.

fixes #123261
---
 compiler/rustc_passes/src/errors.rs           |   4 +-
 compiler/rustc_passes/src/loops.rs            | 172 +++++++++++++++---
 .../loop-if-else-break-issue-123261.fixed     |  31 ++++
 .../loops/loop-if-else-break-issue-123261.rs  |  31 ++++
 .../loop-if-else-break-issue-123261.stderr    |  59 ++++++
 .../break-in-unlabeled-block-in-macro.stderr  |  38 ++--
 6 files changed, 290 insertions(+), 45 deletions(-)
 create mode 100644 tests/ui/loops/loop-if-else-break-issue-123261.fixed
 create mode 100644 tests/ui/loops/loop-if-else-break-issue-123261.rs
 create mode 100644 tests/ui/loops/loop-if-else-break-issue-123261.stderr

diff --git a/compiler/rustc_passes/src/errors.rs b/compiler/rustc_passes/src/errors.rs
index b8586e7e974ad..a55187170937e 100644
--- a/compiler/rustc_passes/src/errors.rs
+++ b/compiler/rustc_passes/src/errors.rs
@@ -1103,7 +1103,7 @@ pub struct BreakInsideCoroutine<'a> {
 pub struct OutsideLoop<'a> {
     #[primary_span]
     #[label]
-    pub span: Span,
+    pub spans: Vec<Span>,
     pub name: &'a str,
     pub is_break: bool,
     #[subdiagnostic]
@@ -1115,7 +1115,7 @@ pub struct OutsideLoopSuggestion {
     #[suggestion_part(code = "'block: ")]
     pub block_span: Span,
     #[suggestion_part(code = " 'block")]
-    pub break_span: Span,
+    pub break_spans: Vec<Span>,
 }
 
 #[derive(Diagnostic)]
diff --git a/compiler/rustc_passes/src/loops.rs b/compiler/rustc_passes/src/loops.rs
index 3b20112eab7b9..2587a18b8c897 100644
--- a/compiler/rustc_passes/src/loops.rs
+++ b/compiler/rustc_passes/src/loops.rs
@@ -1,3 +1,5 @@
+use std::collections::BTreeMap;
+use std::fmt;
 use Context::*;
 
 use rustc_hir as hir;
@@ -25,22 +27,55 @@ enum Context {
     Closure(Span),
     Coroutine { coroutine_span: Span, kind: hir::CoroutineDesugaring, source: hir::CoroutineSource },
     UnlabeledBlock(Span),
+    UnlabeledIfBlock(Span),
     LabeledBlock,
     Constant,
 }
 
-#[derive(Copy, Clone)]
+#[derive(Clone)]
+struct BlockInfo {
+    name: String,
+    spans: Vec<Span>,
+    suggs: Vec<Span>,
+}
+
+#[derive(PartialEq)]
+enum BreakContextKind {
+    Break,
+    Continue,
+}
+
+impl fmt::Display for BreakContextKind {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            BreakContextKind::Break => "break",
+            BreakContextKind::Continue => "continue",
+        }
+        .fmt(f)
+    }
+}
+
+#[derive(Clone)]
 struct CheckLoopVisitor<'a, 'tcx> {
     sess: &'a Session,
     tcx: TyCtxt<'tcx>,
-    cx: Context,
+    // Keep track of a stack of contexts, so that suggestions
+    // are not made for contexts where it would be incorrect,
+    // such as adding a label for an `if`.
+    // e.g. `if 'foo: {}` would be incorrect.
+    cx_stack: Vec<Context>,
+    block_breaks: BTreeMap<Span, BlockInfo>,
 }
 
 fn check_mod_loops(tcx: TyCtxt<'_>, module_def_id: LocalModDefId) {
-    tcx.hir().visit_item_likes_in_module(
-        module_def_id,
-        &mut CheckLoopVisitor { sess: tcx.sess, tcx, cx: Normal },
-    );
+    let mut check = CheckLoopVisitor {
+        sess: tcx.sess,
+        tcx,
+        cx_stack: vec![Normal],
+        block_breaks: Default::default(),
+    };
+    tcx.hir().visit_item_likes_in_module(module_def_id, &mut check);
+    check.report_outside_loop_error();
 }
 
 pub(crate) fn provide(providers: &mut Providers) {
@@ -83,6 +118,45 @@ impl<'a, 'hir> Visitor<'hir> for CheckLoopVisitor<'a, 'hir> {
 
     fn visit_expr(&mut self, e: &'hir hir::Expr<'hir>) {
         match e.kind {
+            hir::ExprKind::If(cond, then, else_opt) => {
+                self.visit_expr(cond);
+
+                let get_block = |ck_loop: &CheckLoopVisitor<'a, 'hir>,
+                                 expr: &hir::Expr<'hir>|
+                 -> Option<&hir::Block<'hir>> {
+                    if let hir::ExprKind::Block(b, None) = expr.kind
+                        && matches!(
+                            ck_loop.cx_stack.last(),
+                            Some(&Normal)
+                                | Some(&Constant)
+                                | Some(&UnlabeledBlock(_))
+                                | Some(&UnlabeledIfBlock(_))
+                        )
+                    {
+                        Some(b)
+                    } else {
+                        None
+                    }
+                };
+
+                if let Some(b) = get_block(self, then) {
+                    self.with_context(UnlabeledIfBlock(b.span.shrink_to_lo()), |v| {
+                        v.visit_block(b)
+                    });
+                } else {
+                    self.visit_expr(then);
+                }
+
+                if let Some(else_expr) = else_opt {
+                    if let Some(b) = get_block(self, else_expr) {
+                        self.with_context(UnlabeledIfBlock(b.span.shrink_to_lo()), |v| {
+                            v.visit_block(b)
+                        });
+                    } else {
+                        self.visit_expr(else_expr);
+                    }
+                }
+            }
             hir::ExprKind::Loop(ref b, _, source, _) => {
                 self.with_context(Loop(source), |v| v.visit_block(b));
             }
@@ -101,11 +175,14 @@ impl<'a, 'hir> Visitor<'hir> for CheckLoopVisitor<'a, 'hir> {
             hir::ExprKind::Block(ref b, Some(_label)) => {
                 self.with_context(LabeledBlock, |v| v.visit_block(b));
             }
-            hir::ExprKind::Block(ref b, None) if matches!(self.cx, Fn) => {
+            hir::ExprKind::Block(ref b, None) if matches!(self.cx_stack.last(), Some(&Fn)) => {
                 self.with_context(Normal, |v| v.visit_block(b));
             }
             hir::ExprKind::Block(ref b, None)
-                if matches!(self.cx, Normal | Constant | UnlabeledBlock(_)) =>
+                if matches!(
+                    self.cx_stack.last(),
+                    Some(&Normal) | Some(&Constant) | Some(&UnlabeledBlock(_))
+                ) =>
             {
                 self.with_context(UnlabeledBlock(b.span.shrink_to_lo()), |v| v.visit_block(b));
             }
@@ -178,7 +255,12 @@ impl<'a, 'hir> Visitor<'hir> for CheckLoopVisitor<'a, 'hir> {
                     Some(label) => sp_lo.with_hi(label.ident.span.hi()),
                     None => sp_lo.shrink_to_lo(),
                 };
-                self.require_break_cx("break", e.span, label_sp);
+                self.require_break_cx(
+                    BreakContextKind::Break,
+                    e.span,
+                    label_sp,
+                    self.cx_stack.len() - 1,
+                );
             }
             hir::ExprKind::Continue(destination) => {
                 self.require_label_in_labeled_block(e.span, &destination, "continue");
@@ -200,7 +282,12 @@ impl<'a, 'hir> Visitor<'hir> for CheckLoopVisitor<'a, 'hir> {
                     }
                     Err(_) => {}
                 }
-                self.require_break_cx("continue", e.span, e.span)
+                self.require_break_cx(
+                    BreakContextKind::Continue,
+                    e.span,
+                    e.span,
+                    self.cx_stack.len() - 1,
+                )
             }
             _ => intravisit::walk_expr(self, e),
         }
@@ -212,18 +299,26 @@ impl<'a, 'hir> CheckLoopVisitor<'a, 'hir> {
     where
         F: FnOnce(&mut CheckLoopVisitor<'a, 'hir>),
     {
-        let old_cx = self.cx;
-        self.cx = cx;
+        self.cx_stack.push(cx);
         f(self);
-        self.cx = old_cx;
+        self.cx_stack.pop();
     }
 
-    fn require_break_cx(&self, name: &str, span: Span, break_span: Span) {
-        let is_break = name == "break";
-        match self.cx {
+    fn require_break_cx(
+        &mut self,
+        br_cx_kind: BreakContextKind,
+        span: Span,
+        break_span: Span,
+        cx_pos: usize,
+    ) {
+        match self.cx_stack[cx_pos] {
             LabeledBlock | Loop(_) => {}
             Closure(closure_span) => {
-                self.sess.dcx().emit_err(BreakInsideClosure { span, closure_span, name });
+                self.sess.dcx().emit_err(BreakInsideClosure {
+                    span,
+                    closure_span,
+                    name: &br_cx_kind.to_string(),
+                });
             }
             Coroutine { coroutine_span, kind, source } => {
                 let kind = match kind {
@@ -239,17 +334,32 @@ impl<'a, 'hir> CheckLoopVisitor<'a, 'hir> {
                 self.sess.dcx().emit_err(BreakInsideCoroutine {
                     span,
                     coroutine_span,
-                    name,
+                    name: &br_cx_kind.to_string(),
                     kind,
                     source,
                 });
             }
-            UnlabeledBlock(block_span) if is_break && block_span.eq_ctxt(break_span) => {
-                let suggestion = Some(OutsideLoopSuggestion { block_span, break_span });
-                self.sess.dcx().emit_err(OutsideLoop { span, name, is_break, suggestion });
+            UnlabeledBlock(block_span)
+                if br_cx_kind == BreakContextKind::Break && block_span.eq_ctxt(break_span) =>
+            {
+                let block = self.block_breaks.entry(block_span).or_insert_with(|| BlockInfo {
+                    name: br_cx_kind.to_string(),
+                    spans: vec![],
+                    suggs: vec![],
+                });
+                block.spans.push(span);
+                block.suggs.push(break_span);
+            }
+            UnlabeledIfBlock(_) if br_cx_kind == BreakContextKind::Break => {
+                self.require_break_cx(br_cx_kind, span, break_span, cx_pos - 1);
             }
-            Normal | Constant | Fn | UnlabeledBlock(_) => {
-                self.sess.dcx().emit_err(OutsideLoop { span, name, is_break, suggestion: None });
+            Normal | Constant | Fn | UnlabeledBlock(_) | UnlabeledIfBlock(_) => {
+                self.sess.dcx().emit_err(OutsideLoop {
+                    spans: vec![span],
+                    name: &br_cx_kind.to_string(),
+                    is_break: br_cx_kind == BreakContextKind::Break,
+                    suggestion: None,
+                });
             }
         }
     }
@@ -261,7 +371,7 @@ impl<'a, 'hir> CheckLoopVisitor<'a, 'hir> {
         cf_type: &str,
     ) -> bool {
         if !span.is_desugaring(DesugaringKind::QuestionMark)
-            && self.cx == LabeledBlock
+            && self.cx_stack.last() == Some(&LabeledBlock)
             && label.label.is_none()
         {
             self.sess.dcx().emit_err(UnlabeledInLabeledBlock { span, cf_type });
@@ -269,4 +379,18 @@ impl<'a, 'hir> CheckLoopVisitor<'a, 'hir> {
         }
         false
     }
+
+    fn report_outside_loop_error(&mut self) {
+        for (s, block) in &self.block_breaks {
+            self.sess.dcx().emit_err(OutsideLoop {
+                spans: block.spans.clone(),
+                name: &block.name,
+                is_break: true,
+                suggestion: Some(OutsideLoopSuggestion {
+                    block_span: *s,
+                    break_spans: block.suggs.clone(),
+                }),
+            });
+        }
+    }
 }
diff --git a/tests/ui/loops/loop-if-else-break-issue-123261.fixed b/tests/ui/loops/loop-if-else-break-issue-123261.fixed
new file mode 100644
index 0000000000000..f9e88c18ad02c
--- /dev/null
+++ b/tests/ui/loops/loop-if-else-break-issue-123261.fixed
@@ -0,0 +1,31 @@
+//@ run-rustfix
+
+#![allow(unused)]
+
+fn main() {
+    let n = 1;
+    let m = 2;
+    let x = 'block: {
+        if n == 0 {
+            break 'block 1; //~ ERROR [E0268]
+        } else {
+            break 'block 2;
+        }
+    };
+
+    let y = 'block: {
+        if n == 0 {
+            break 'block 1; //~ ERROR [E0268]
+        }
+        break 'block 0;
+    };
+
+    let z = 'block: {
+        if n == 0 {
+            if m > 1 {
+                break 'block 3; //~ ERROR [E0268]
+            }
+        }
+        break 'block 1;
+    };
+}
diff --git a/tests/ui/loops/loop-if-else-break-issue-123261.rs b/tests/ui/loops/loop-if-else-break-issue-123261.rs
new file mode 100644
index 0000000000000..a1f9dabe891fd
--- /dev/null
+++ b/tests/ui/loops/loop-if-else-break-issue-123261.rs
@@ -0,0 +1,31 @@
+//@ run-rustfix
+
+#![allow(unused)]
+
+fn main() {
+    let n = 1;
+    let m = 2;
+    let x = {
+        if n == 0 {
+            break 1; //~ ERROR [E0268]
+        } else {
+            break 2;
+        }
+    };
+
+    let y = {
+        if n == 0 {
+            break 1; //~ ERROR [E0268]
+        }
+        break 0;
+    };
+
+    let z = {
+        if n == 0 {
+            if m > 1 {
+                break 3; //~ ERROR [E0268]
+            }
+        }
+        break 1;
+    };
+}
diff --git a/tests/ui/loops/loop-if-else-break-issue-123261.stderr b/tests/ui/loops/loop-if-else-break-issue-123261.stderr
new file mode 100644
index 0000000000000..7bd192fc00b0d
--- /dev/null
+++ b/tests/ui/loops/loop-if-else-break-issue-123261.stderr
@@ -0,0 +1,59 @@
+error[E0268]: `break` outside of a loop or labeled block
+  --> $DIR/loop-if-else-break-issue-123261.rs:10:13
+   |
+LL |             break 1;
+   |             ^^^^^^^ cannot `break` outside of a loop or labeled block
+LL |         } else {
+LL |             break 2;
+   |             ^^^^^^^ cannot `break` outside of a loop or labeled block
+   |
+help: consider labeling this block to be able to break within it
+   |
+LL ~     let x = 'block: {
+LL |         if n == 0 {
+LL ~             break 'block 1;
+LL |         } else {
+LL ~             break 'block 2;
+   |
+
+error[E0268]: `break` outside of a loop or labeled block
+  --> $DIR/loop-if-else-break-issue-123261.rs:18:13
+   |
+LL |             break 1;
+   |             ^^^^^^^ cannot `break` outside of a loop or labeled block
+LL |         }
+LL |         break 0;
+   |         ^^^^^^^ cannot `break` outside of a loop or labeled block
+   |
+help: consider labeling this block to be able to break within it
+   |
+LL ~     let y = 'block: {
+LL |         if n == 0 {
+LL ~             break 'block 1;
+LL |         }
+LL ~         break 'block 0;
+   |
+
+error[E0268]: `break` outside of a loop or labeled block
+  --> $DIR/loop-if-else-break-issue-123261.rs:26:17
+   |
+LL |                 break 3;
+   |                 ^^^^^^^ cannot `break` outside of a loop or labeled block
+...
+LL |         break 1;
+   |         ^^^^^^^ cannot `break` outside of a loop or labeled block
+   |
+help: consider labeling this block to be able to break within it
+   |
+LL ~     let z = 'block: {
+LL |         if n == 0 {
+LL |             if m > 1 {
+LL ~                 break 'block 3;
+LL |             }
+LL |         }
+LL ~         break 'block 1;
+   |
+
+error: aborting due to 3 previous errors
+
+For more information about this error, try `rustc --explain E0268`.
diff --git a/tests/ui/parser/break-in-unlabeled-block-in-macro.stderr b/tests/ui/parser/break-in-unlabeled-block-in-macro.stderr
index 9407e8ac0029d..2f46cb36750be 100644
--- a/tests/ui/parser/break-in-unlabeled-block-in-macro.stderr
+++ b/tests/ui/parser/break-in-unlabeled-block-in-macro.stderr
@@ -21,16 +21,21 @@ LL |         foo!(());
    = note: this error originates in the macro `foo` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0268]: `break` outside of a loop or labeled block
-  --> $DIR/break-in-unlabeled-block-in-macro.rs:27:19
-   |
-LL |         foo!(stmt break ());
-   |                   ^^^^^^^^ cannot `break` outside of a loop or labeled block
+  --> $DIR/break-in-unlabeled-block-in-macro.rs:33:17
    |
-help: consider labeling this block to be able to break within it
+LL |         foo!(=> break ());
+   |                 ^^^^^^^^ cannot `break` outside of a loop or labeled block
+
+error[E0268]: `break` outside of a loop or labeled block
+  --> $DIR/break-in-unlabeled-block-in-macro.rs:38:17
    |
-LL ~     'block: {
-LL ~         foo!(stmt break 'block ());
+LL |                 break ()
+   |                 ^^^^^^^^ cannot `break` outside of a loop or labeled block
+...
+LL |         bar!()
+   |         ------ in this macro invocation
    |
+   = note: this error originates in the macro `bar` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0268]: `break` outside of a loop or labeled block
   --> $DIR/break-in-unlabeled-block-in-macro.rs:12:11
@@ -48,21 +53,16 @@ LL |         'block: { break 'block $e; }
    |         +++++++         ++++++
 
 error[E0268]: `break` outside of a loop or labeled block
-  --> $DIR/break-in-unlabeled-block-in-macro.rs:33:17
+  --> $DIR/break-in-unlabeled-block-in-macro.rs:27:19
    |
-LL |         foo!(=> break ());
-   |                 ^^^^^^^^ cannot `break` outside of a loop or labeled block
-
-error[E0268]: `break` outside of a loop or labeled block
-  --> $DIR/break-in-unlabeled-block-in-macro.rs:38:17
+LL |         foo!(stmt break ());
+   |                   ^^^^^^^^ cannot `break` outside of a loop or labeled block
    |
-LL |                 break ()
-   |                 ^^^^^^^^ cannot `break` outside of a loop or labeled block
-...
-LL |         bar!()
-   |         ------ in this macro invocation
+help: consider labeling this block to be able to break within it
+   |
+LL ~     'block: {
+LL ~         foo!(stmt break 'block ());
    |
-   = note: this error originates in the macro `bar` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: aborting due to 6 previous errors
 

From 5da41f59dafc7356dedba9c1e0fbd1cc1aa55491 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Wed, 22 May 2024 16:37:12 +0000
Subject: [PATCH 12/21] self-contained linker: retry without -fuse-ld=lld on
 older GCCs

---
 compiler/rustc_codegen_ssa/src/back/link.rs | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/compiler/rustc_codegen_ssa/src/back/link.rs b/compiler/rustc_codegen_ssa/src/back/link.rs
index 37b8f81ad9465..c973bda1ef14f 100644
--- a/compiler/rustc_codegen_ssa/src/back/link.rs
+++ b/compiler/rustc_codegen_ssa/src/back/link.rs
@@ -799,6 +799,27 @@ fn link_natively(
             continue;
         }
 
+        // Check if linking failed with an error message that indicates the driver didn't recognize
+        // the `-fuse-ld=lld` option. If so, re-perform the link step without it. This avoids having
+        // to spawn multiple instances on the happy path to do version checking, and ensures things
+        // keep working on the tier 1 baseline of GLIBC 2.17+. That is generally understood as GCCs
+        // circa RHEL/CentOS 7, 4.5 or so, whereas lld support was added in GCC 9.
+        if matches!(flavor, LinkerFlavor::Gnu(Cc::Yes, Lld::Yes))
+            && unknown_arg_regex.is_match(&out)
+            && out.contains("-fuse-ld=lld")
+            && cmd.get_args().iter().any(|e| e.to_string_lossy() == "-fuse-ld=lld")
+        {
+            info!("linker output: {:?}", out);
+            warn!("The linker driver does not support `-fuse-ld=lld`. Retrying without it.");
+            for arg in cmd.take_args() {
+                if arg.to_string_lossy() != "-fuse-ld=lld" {
+                    cmd.arg(arg);
+                }
+            }
+            info!("{:?}", &cmd);
+            continue;
+        }
+
         // Detect '-static-pie' used with an older version of gcc or clang not supporting it.
         // Fallback from '-static-pie' to '-static' in that case.
         if matches!(flavor, LinkerFlavor::Gnu(Cc::Yes, _))

From c8844dfdc00fbfe4b5e7839635214b744410312f Mon Sep 17 00:00:00 2001
From: Nicholas Nethercote <n.nethercote@gmail.com>
Date: Mon, 20 May 2024 08:45:54 +1000
Subject: [PATCH 13/21] Clarify the meaning of the span within
 `mbe::TokenTree::MetaVar`.

---
 compiler/rustc_expand/src/mbe.rs        |  3 ++-
 compiler/rustc_expand/src/mbe/quoted.rs | 19 +++++++++++--------
 2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/compiler/rustc_expand/src/mbe.rs b/compiler/rustc_expand/src/mbe.rs
index a805c4fcf7b97..32d12c4fd0cc9 100644
--- a/compiler/rustc_expand/src/mbe.rs
+++ b/compiler/rustc_expand/src/mbe.rs
@@ -73,7 +73,8 @@ enum TokenTree {
     Delimited(DelimSpan, DelimSpacing, Delimited),
     /// A kleene-style repetition sequence, e.g. `$($e:expr)*` (RHS) or `$($e),*` (LHS).
     Sequence(DelimSpan, SequenceRepetition),
-    /// e.g., `$var`.
+    /// e.g., `$var`. The span covers the leading dollar and the ident. (The span within the ident
+    /// only covers the ident, e.g. `var`.)
     MetaVar(Span, Ident),
     /// e.g., `$var:expr`. Only appears on the LHS.
     MetaVarDecl(Span, Ident /* name to bind */, Option<NonterminalKind>),
diff --git a/compiler/rustc_expand/src/mbe/quoted.rs b/compiler/rustc_expand/src/mbe/quoted.rs
index d3ea48e2e2a8e..2e37fd70df9a7 100644
--- a/compiler/rustc_expand/src/mbe/quoted.rs
+++ b/compiler/rustc_expand/src/mbe/quoted.rs
@@ -176,7 +176,7 @@ fn parse_tree<'a>(
     // Depending on what `tree` is, we could be parsing different parts of a macro
     match tree {
         // `tree` is a `$` token. Look at the next token in `trees`
-        &tokenstream::TokenTree::Token(Token { kind: token::Dollar, span }, _) => {
+        &tokenstream::TokenTree::Token(Token { kind: token::Dollar, span: dollar_span }, _) => {
             // FIXME: Handle `Invisible`-delimited groups in a more systematic way
             // during parsing.
             let mut next = outer_trees.next();
@@ -209,7 +209,7 @@ fn parse_tree<'a>(
                                         err.emit();
                                         // Returns early the same read `$` to avoid spanning
                                         // unrelated diagnostics that could be performed afterwards
-                                        return TokenTree::token(token::Dollar, span);
+                                        return TokenTree::token(token::Dollar, dollar_span);
                                     }
                                     Ok(elem) => {
                                         maybe_emit_macro_metavar_expr_feature(
@@ -251,7 +251,7 @@ fn parse_tree<'a>(
                 // special metavariable that names the crate of the invocation.
                 Some(tokenstream::TokenTree::Token(token, _)) if token.is_ident() => {
                     let (ident, is_raw) = token.ident().unwrap();
-                    let span = ident.span.with_lo(span.lo());
+                    let span = ident.span.with_lo(dollar_span.lo());
                     if ident.name == kw::Crate && matches!(is_raw, IdentIsRaw::No) {
                         TokenTree::token(token::Ident(kw::DollarCrate, is_raw), span)
                     } else {
@@ -260,16 +260,19 @@ fn parse_tree<'a>(
                 }
 
                 // `tree` is followed by another `$`. This is an escaped `$`.
-                Some(&tokenstream::TokenTree::Token(Token { kind: token::Dollar, span }, _)) => {
+                Some(&tokenstream::TokenTree::Token(
+                    Token { kind: token::Dollar, span: dollar_span2 },
+                    _,
+                )) => {
                     if parsing_patterns {
                         span_dollar_dollar_or_metavar_in_the_lhs_err(
                             sess,
-                            &Token { kind: token::Dollar, span },
+                            &Token { kind: token::Dollar, span: dollar_span2 },
                         );
                     } else {
-                        maybe_emit_macro_metavar_expr_feature(features, sess, span);
+                        maybe_emit_macro_metavar_expr_feature(features, sess, dollar_span2);
                     }
-                    TokenTree::token(token::Dollar, span)
+                    TokenTree::token(token::Dollar, dollar_span2)
                 }
 
                 // `tree` is followed by some other token. This is an error.
@@ -281,7 +284,7 @@ fn parse_tree<'a>(
                 }
 
                 // There are no more tokens. Just return the `$` we already have.
-                None => TokenTree::token(token::Dollar, span),
+                None => TokenTree::token(token::Dollar, dollar_span),
             }
         }
 

From 3fc8f8998c45fbc211b98b5bae04cc87f8eb1619 Mon Sep 17 00:00:00 2001
From: Nicholas Nethercote <n.nethercote@gmail.com>
Date: Mon, 20 May 2024 09:20:49 +1000
Subject: [PATCH 14/21] Clarify `parse` a little.

- Name the colon span as `colon_span` to distinguish it from the other
  `span` local variable.
- Just use basic pattern matching, which is easier to read than `map_or`.
---
 compiler/rustc_expand/src/mbe/quoted.rs | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/compiler/rustc_expand/src/mbe/quoted.rs b/compiler/rustc_expand/src/mbe/quoted.rs
index 2e37fd70df9a7..8ad7cb15c92a9 100644
--- a/compiler/rustc_expand/src/mbe/quoted.rs
+++ b/compiler/rustc_expand/src/mbe/quoted.rs
@@ -62,7 +62,10 @@ pub(super) fn parse(
         match tree {
             TokenTree::MetaVar(start_sp, ident) if parsing_patterns => {
                 let span = match trees.next() {
-                    Some(&tokenstream::TokenTree::Token(Token { kind: token::Colon, span }, _)) => {
+                    Some(&tokenstream::TokenTree::Token(
+                        Token { kind: token::Colon, span: colon_span },
+                        _,
+                    )) => {
                         match trees.next() {
                             Some(tokenstream::TokenTree::Token(token, _)) => match token.ident() {
                                 Some((fragment, _)) => {
@@ -126,10 +129,12 @@ pub(super) fn parse(
                                 }
                                 _ => token.span,
                             },
-                            tree => tree.map_or(span, tokenstream::TokenTree::span),
+                            Some(tree) => tree.span(),
+                            None => colon_span,
                         }
                     }
-                    tree => tree.map_or(start_sp, tokenstream::TokenTree::span),
+                    Some(tree) => tree.span(),
+                    None => start_sp,
                 };
 
                 result.push(TokenTree::MetaVarDecl(span, ident, None));

From b6de7821982caf99f58e2925ae3cb78673b31e24 Mon Sep 17 00:00:00 2001
From: Nicholas Nethercote <n.nethercote@gmail.com>
Date: Fri, 17 May 2024 09:54:53 +1000
Subject: [PATCH 15/21] Clarify a comment.

---
 compiler/rustc_expand/src/proc_macro_server.rs | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/compiler/rustc_expand/src/proc_macro_server.rs b/compiler/rustc_expand/src/proc_macro_server.rs
index 1f3547c841a90..ec7e4416b9130 100644
--- a/compiler/rustc_expand/src/proc_macro_server.rs
+++ b/compiler/rustc_expand/src/proc_macro_server.rs
@@ -309,10 +309,10 @@ impl ToInternal<SmallVec<[tokenstream::TokenTree; 2]>>
         use rustc_ast::token::*;
 
         // The code below is conservative, using `token_alone`/`Spacing::Alone`
-        // in most places. When the resulting code is pretty-printed by
-        // `print_tts` it ends up with spaces between most tokens, which is
-        // safe but ugly. It's hard in general to do better when working at the
-        // token level.
+        // in most places. It's hard in general to do better when working at
+        // the token level. When the resulting code is pretty-printed by
+        // `print_tts` the `space_between` function helps avoid a lot of
+        // unnecessary whitespace, so the results aren't too bad.
         let (tree, rustc) = self;
         match tree {
             TokenTree::Punct(Punct { ch, joint, span }) => {

From c679a5510222cb861a2a23088d1365707d1e0d6f Mon Sep 17 00:00:00 2001
From: Nicholas Nethercote <n.nethercote@gmail.com>
Date: Fri, 17 May 2024 09:49:09 +1000
Subject: [PATCH 16/21] Convert some `token_joint_hidden` calls to
 `token_joint`.

This has no noticeable effect, but it makes these cases follow the
guidelines in the comments on `Spacing`, which say that `Joint` should
be used "for each token that (a) should be pretty-printed without a
space after it, and (b) is followed by a punctuation token".

These two tokens are both followed by a comma, which is a punctuation
token.
---
 compiler/rustc_builtin_macros/src/assert/context.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/compiler/rustc_builtin_macros/src/assert/context.rs b/compiler/rustc_builtin_macros/src/assert/context.rs
index 085ea3458bbfa..7814422611439 100644
--- a/compiler/rustc_builtin_macros/src/assert/context.rs
+++ b/compiler/rustc_builtin_macros/src/assert/context.rs
@@ -153,7 +153,7 @@ impl<'cx, 'a> Context<'cx, 'a> {
     fn build_panic(&self, expr_str: &str, panic_path: Path) -> P<Expr> {
         let escaped_expr_str = escape_to_fmt(expr_str);
         let initial = [
-            TokenTree::token_joint_hidden(
+            TokenTree::token_joint(
                 token::Literal(token::Lit {
                     kind: token::LitKind::Str,
                     symbol: Symbol::intern(&if self.fmt_string.is_empty() {
@@ -172,7 +172,7 @@ impl<'cx, 'a> Context<'cx, 'a> {
         ];
         let captures = self.capture_decls.iter().flat_map(|cap| {
             [
-                TokenTree::token_joint_hidden(
+                TokenTree::token_joint(
                     token::Ident(cap.ident.name, IdentIsRaw::No),
                     cap.ident.span,
                 ),

From a1b6d46e040176e63954ba3ba5bb18cd4ed3691a Mon Sep 17 00:00:00 2001
From: Nicholas Nethercote <n.nethercote@gmail.com>
Date: Fri, 17 May 2024 08:23:24 +1000
Subject: [PATCH 17/21] Use `JointHidden` in a couple of suitable places.

This has no notable effect, but it's appropriate because the relevant
tokens are followed by delimiters.
---
 compiler/rustc_ast/src/tokenstream.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/compiler/rustc_ast/src/tokenstream.rs b/compiler/rustc_ast/src/tokenstream.rs
index fb666550e9302..3d46415507def 100644
--- a/compiler/rustc_ast/src/tokenstream.rs
+++ b/compiler/rustc_ast/src/tokenstream.rs
@@ -661,11 +661,11 @@ impl TokenStream {
             if attr_style == AttrStyle::Inner {
                 vec![
                     TokenTree::token_joint(token::Pound, span),
-                    TokenTree::token_alone(token::Not, span),
+                    TokenTree::token_joint_hidden(token::Not, span),
                     body,
                 ]
             } else {
-                vec![TokenTree::token_alone(token::Pound, span), body]
+                vec![TokenTree::token_joint_hidden(token::Pound, span), body]
             }
         }
     }

From 4d513cb4bf7d8c3151594096e97cd848f5fcab77 Mon Sep 17 00:00:00 2001
From: Nicholas Nethercote <n.nethercote@gmail.com>
Date: Mon, 20 May 2024 12:54:38 +1000
Subject: [PATCH 18/21] Add some comments.

---
 compiler/rustc_ast_pretty/src/pprust/state.rs | 40 ++++++++++++++-----
 compiler/rustc_expand/src/mbe.rs              |  2 +
 compiler/rustc_expand/src/mbe/transcribe.rs   | 15 +++++++
 3 files changed, 46 insertions(+), 11 deletions(-)

diff --git a/compiler/rustc_ast_pretty/src/pprust/state.rs b/compiler/rustc_ast_pretty/src/pprust/state.rs
index 545b98a9135af..f02fe4cf0a728 100644
--- a/compiler/rustc_ast_pretty/src/pprust/state.rs
+++ b/compiler/rustc_ast_pretty/src/pprust/state.rs
@@ -681,22 +681,40 @@ pub trait PrintState<'a>: std::ops::Deref<Target = pp::Printer> + std::ops::Dere
         }
     }
 
+    // The easiest way to implement token stream pretty printing would be to
+    // print each token followed by a single space. But that would produce ugly
+    // output, so we go to some effort to do better.
+    //
+    // First, we track whether each token that appears in source code is
+    // followed by a space, with `Spacing`, and reproduce that in the output.
+    // This works well in a lot of cases. E.g. `stringify!(x + y)` produces
+    // "x + y" and `stringify!(x+y)` produces "x+y".
+    //
+    // But this doesn't work for code produced by proc macros (which have no
+    // original source text representation) nor for code produced by decl
+    // macros (which are tricky because the whitespace after tokens appearing
+    // in macro rules isn't always what you want in the produced output). For
+    // these we mostly use `Spacing::Alone`, which is the conservative choice.
+    //
+    // So we have a backup mechanism for when `Spacing::Alone` occurs between a
+    // pair of tokens: we check if that pair of tokens can obviously go
+    // together without a space between them. E.g. token `x` followed by token
+    // `,` is better printed as `x,` than `x ,`. (Even if the original source
+    // code was `x ,`.)
+    //
+    // Finally, we must be careful about changing the output. Token pretty
+    // printing is used by `stringify!` and `impl Display for
+    // proc_macro::TokenStream`, and some programs rely on the output having a
+    // particular form, even though they shouldn't. In particular, some proc
+    // macros do `format!({stream})` on a token stream and then "parse" the
+    // output with simple string matching that can't handle whitespace changes.
+    // E.g. we have seen cases where a proc macro can handle `a :: b` but not
+    // `a::b`. See #117433 for some examples.
     fn print_tts(&mut self, tts: &TokenStream, convert_dollar_crate: bool) {
         let mut iter = tts.trees().peekable();
         while let Some(tt) = iter.next() {
             let spacing = self.print_tt(tt, convert_dollar_crate);
             if let Some(next) = iter.peek() {
-                // Should we print a space after `tt`? There are two guiding
-                // factors.
-                // - `spacing` is the more important and accurate one. Most
-                //   tokens have good spacing information, and
-                //   `Joint`/`JointHidden` get used a lot.
-                // - `space_between` is the backup. Code produced by proc
-                //   macros has worse spacing information, with no
-                //   `JointHidden` usage and too much `Alone` usage, which
-                //   would result in over-spaced output such as
-                //   `( x () , y . z )`. `space_between` avoids some of the
-                //   excess whitespace.
                 if spacing == Spacing::Alone && space_between(tt, next) {
                     self.space();
                 }
diff --git a/compiler/rustc_expand/src/mbe.rs b/compiler/rustc_expand/src/mbe.rs
index 32d12c4fd0cc9..08d4a03945489 100644
--- a/compiler/rustc_expand/src/mbe.rs
+++ b/compiler/rustc_expand/src/mbe.rs
@@ -68,6 +68,8 @@ pub(crate) enum KleeneOp {
 /// `MetaVarExpr` are "first-class" token trees. Useful for parsing macros.
 #[derive(Debug, PartialEq, Encodable, Decodable)]
 enum TokenTree {
+    /// A token. Unlike `tokenstream::TokenTree::Token` this lacks a `Spacing`.
+    /// See the comments about `Spacing` in the `transcribe` function.
     Token(Token),
     /// A delimited sequence, e.g. `($e:expr)` (RHS) or `{ $e }` (LHS).
     Delimited(DelimSpan, DelimSpacing, Delimited),
diff --git a/compiler/rustc_expand/src/mbe/transcribe.rs b/compiler/rustc_expand/src/mbe/transcribe.rs
index 3901b82eb52ec..8a084dcb4fe3a 100644
--- a/compiler/rustc_expand/src/mbe/transcribe.rs
+++ b/compiler/rustc_expand/src/mbe/transcribe.rs
@@ -253,8 +253,23 @@ pub(super) fn transcribe<'a>(
             mbe::TokenTree::MetaVar(mut sp, mut original_ident) => {
                 // Find the matched nonterminal from the macro invocation, and use it to replace
                 // the meta-var.
+                //
+                // We use `Spacing::Alone` everywhere here, because that's the conservative choice
+                // and spacing of declarative macros is tricky. E.g. in this macro:
+                // ```
+                // macro_rules! idents {
+                //     ($($a:ident,)*) => { stringify!($($a)*) }
+                // }
+                // ```
+                // `$a` has no whitespace after it and will be marked `JointHidden`. If you then
+                // call `idents!(x,y,z,)`, each of `x`, `y`, and `z` will be marked as `Joint`. So
+                // if you choose to use `$x`'s spacing or the identifier's spacing, you'll end up
+                // producing "xyz", which is bad because it effectively merges tokens.
+                // `Spacing::Alone` is the safer option. Fortunately, `space_between` will avoid
+                // some of the unnecessary whitespace.
                 let ident = MacroRulesNormalizedIdent::new(original_ident);
                 if let Some(cur_matched) = lookup_cur_matched(ident, interp, &repeats) {
+                    // njn: explain the use of alone here
                     let tt = match cur_matched {
                         MatchedSingle(ParseNtResult::Tt(tt)) => {
                             // `tt`s are emitted into the output stream directly as "raw tokens",

From 07b7cd62c70ef6ec111e9a7182cb83ec0209460e Mon Sep 17 00:00:00 2001
From: Eric Huss <eric@huss.org>
Date: Sun, 17 Mar 2024 15:46:40 -0700
Subject: [PATCH 19/21] Add some tests for public-private dependencies.

---
 .../auxiliary/diamond_priv_dep.rs             |  9 +++
 .../pub-priv-dep/auxiliary/diamond_pub_dep.rs |  9 +++
 .../pub-priv-dep/auxiliary/indirect1.rs       |  4 ++
 .../pub-priv-dep/auxiliary/indirect2.rs       |  4 ++
 tests/ui/privacy/pub-priv-dep/auxiliary/pm.rs | 22 ++++++
 .../pub-priv-dep/auxiliary/priv_dep.rs        |  9 +++
 .../pub-priv-dep/auxiliary/reexport.rs        |  5 ++
 .../privacy/pub-priv-dep/auxiliary/shared.rs  |  1 +
 tests/ui/privacy/pub-priv-dep/diamond_deps.rs | 48 +++++++++++++
 .../privacy/pub-priv-dep/diamond_deps.stderr  | 14 ++++
 tests/ui/privacy/pub-priv-dep/pub-priv1.rs    | 67 ++++++++++++++++++-
 .../ui/privacy/pub-priv-dep/pub-priv1.stderr  | 62 +++++++++++++++--
 .../pub-priv-dep/reexport_from_priv.rs        | 15 +++++
 .../pub-priv-dep/shared_both_private.rs       | 32 +++++++++
 .../pub-priv-dep/shared_direct_private.rs     | 39 +++++++++++
 .../privacy/pub-priv-dep/shared_indirect.rs   | 29 ++++++++
 16 files changed, 360 insertions(+), 9 deletions(-)
 create mode 100644 tests/ui/privacy/pub-priv-dep/auxiliary/diamond_priv_dep.rs
 create mode 100644 tests/ui/privacy/pub-priv-dep/auxiliary/diamond_pub_dep.rs
 create mode 100644 tests/ui/privacy/pub-priv-dep/auxiliary/indirect1.rs
 create mode 100644 tests/ui/privacy/pub-priv-dep/auxiliary/indirect2.rs
 create mode 100644 tests/ui/privacy/pub-priv-dep/auxiliary/pm.rs
 create mode 100644 tests/ui/privacy/pub-priv-dep/auxiliary/reexport.rs
 create mode 100644 tests/ui/privacy/pub-priv-dep/auxiliary/shared.rs
 create mode 100644 tests/ui/privacy/pub-priv-dep/diamond_deps.rs
 create mode 100644 tests/ui/privacy/pub-priv-dep/diamond_deps.stderr
 create mode 100644 tests/ui/privacy/pub-priv-dep/reexport_from_priv.rs
 create mode 100644 tests/ui/privacy/pub-priv-dep/shared_both_private.rs
 create mode 100644 tests/ui/privacy/pub-priv-dep/shared_direct_private.rs
 create mode 100644 tests/ui/privacy/pub-priv-dep/shared_indirect.rs

diff --git a/tests/ui/privacy/pub-priv-dep/auxiliary/diamond_priv_dep.rs b/tests/ui/privacy/pub-priv-dep/auxiliary/diamond_priv_dep.rs
new file mode 100644
index 0000000000000..ed76815a6ac8e
--- /dev/null
+++ b/tests/ui/privacy/pub-priv-dep/auxiliary/diamond_priv_dep.rs
@@ -0,0 +1,9 @@
+//@ aux-crate:shared=shared.rs
+
+extern crate shared;
+
+pub use shared::Shared;
+
+pub struct SharedInType {
+    pub f: Shared
+}
diff --git a/tests/ui/privacy/pub-priv-dep/auxiliary/diamond_pub_dep.rs b/tests/ui/privacy/pub-priv-dep/auxiliary/diamond_pub_dep.rs
new file mode 100644
index 0000000000000..ed76815a6ac8e
--- /dev/null
+++ b/tests/ui/privacy/pub-priv-dep/auxiliary/diamond_pub_dep.rs
@@ -0,0 +1,9 @@
+//@ aux-crate:shared=shared.rs
+
+extern crate shared;
+
+pub use shared::Shared;
+
+pub struct SharedInType {
+    pub f: Shared
+}
diff --git a/tests/ui/privacy/pub-priv-dep/auxiliary/indirect1.rs b/tests/ui/privacy/pub-priv-dep/auxiliary/indirect1.rs
new file mode 100644
index 0000000000000..0e4a73c7fc011
--- /dev/null
+++ b/tests/ui/privacy/pub-priv-dep/auxiliary/indirect1.rs
@@ -0,0 +1,4 @@
+//@ aux-crate:priv:indirect2=indirect2.rs
+//@ compile-flags: -Zunstable-options
+
+extern crate indirect2;
diff --git a/tests/ui/privacy/pub-priv-dep/auxiliary/indirect2.rs b/tests/ui/privacy/pub-priv-dep/auxiliary/indirect2.rs
new file mode 100644
index 0000000000000..5f6b289eb1414
--- /dev/null
+++ b/tests/ui/privacy/pub-priv-dep/auxiliary/indirect2.rs
@@ -0,0 +1,4 @@
+//@ aux-crate:shared=shared.rs
+
+// This is public.
+extern crate shared;
diff --git a/tests/ui/privacy/pub-priv-dep/auxiliary/pm.rs b/tests/ui/privacy/pub-priv-dep/auxiliary/pm.rs
new file mode 100644
index 0000000000000..9e2aa898afe8d
--- /dev/null
+++ b/tests/ui/privacy/pub-priv-dep/auxiliary/pm.rs
@@ -0,0 +1,22 @@
+//@ force-host
+//@ no-prefer-dynamic
+
+#![crate_type = "proc-macro"]
+
+extern crate proc_macro;
+use proc_macro::TokenStream;
+
+#[proc_macro]
+pub fn fn_like(input: TokenStream) -> TokenStream {
+    "".parse().unwrap()
+}
+
+#[proc_macro_derive(PmDerive)]
+pub fn pm_derive(item: TokenStream) -> TokenStream {
+    "".parse().unwrap()
+}
+
+#[proc_macro_attribute]
+pub fn pm_attr(attr: TokenStream, item: TokenStream) -> TokenStream {
+    "".parse().unwrap()
+}
diff --git a/tests/ui/privacy/pub-priv-dep/auxiliary/priv_dep.rs b/tests/ui/privacy/pub-priv-dep/auxiliary/priv_dep.rs
index e7afeb84fb4f4..4eeecdc056972 100644
--- a/tests/ui/privacy/pub-priv-dep/auxiliary/priv_dep.rs
+++ b/tests/ui/privacy/pub-priv-dep/auxiliary/priv_dep.rs
@@ -1,2 +1,11 @@
 pub struct OtherType;
 pub trait OtherTrait {}
+
+#[macro_export]
+macro_rules! m {
+    () => {};
+}
+
+pub enum E {
+    V1
+}
diff --git a/tests/ui/privacy/pub-priv-dep/auxiliary/reexport.rs b/tests/ui/privacy/pub-priv-dep/auxiliary/reexport.rs
new file mode 100644
index 0000000000000..0655e3ae2cfdb
--- /dev/null
+++ b/tests/ui/privacy/pub-priv-dep/auxiliary/reexport.rs
@@ -0,0 +1,5 @@
+//@ aux-crate:shared=shared.rs
+
+extern crate shared;
+
+pub use shared::Shared;
diff --git a/tests/ui/privacy/pub-priv-dep/auxiliary/shared.rs b/tests/ui/privacy/pub-priv-dep/auxiliary/shared.rs
new file mode 100644
index 0000000000000..efc4daa7befb8
--- /dev/null
+++ b/tests/ui/privacy/pub-priv-dep/auxiliary/shared.rs
@@ -0,0 +1 @@
+pub struct Shared;
diff --git a/tests/ui/privacy/pub-priv-dep/diamond_deps.rs b/tests/ui/privacy/pub-priv-dep/diamond_deps.rs
new file mode 100644
index 0000000000000..0e1f6f36bc8cc
--- /dev/null
+++ b/tests/ui/privacy/pub-priv-dep/diamond_deps.rs
@@ -0,0 +1,48 @@
+//@ aux-crate:priv:diamond_priv_dep=diamond_priv_dep.rs
+//@ aux-crate:diamond_pub_dep=diamond_pub_dep.rs
+//@ compile-flags: -Zunstable-options
+
+// A diamond dependency:
+//
+//           diamond_reepxort
+//                  /\
+//        (public) /  \ (PRIVATE)
+//                /    \
+//   diamond_pub_dep  diamond_priv_dep
+//                \    /
+//        (public) \  /  (public)
+//                  \/
+//                shared
+//
+// Where the pub and private crates reexport something from the shared crate.
+//
+// Checks the behavior when the same shared item appears in the public API,
+// depending on whether it comes from the public side or the private side.
+//
+// NOTE: compiletest does not support deduplicating shared dependencies.
+// However, it should work well enough for this test, the only downside is
+// that diamond_shared gets built twice.
+
+#![crate_type = "lib"]
+#![deny(exported_private_dependencies)]
+
+extern crate diamond_priv_dep;
+extern crate diamond_pub_dep;
+
+// FIXME: This should trigger.
+pub fn leaks_priv() -> diamond_priv_dep::Shared {
+    diamond_priv_dep::Shared
+}
+
+pub fn leaks_pub() -> diamond_pub_dep::Shared {
+    diamond_pub_dep::Shared
+}
+
+pub struct PrivInStruct {
+    pub f: diamond_priv_dep::SharedInType
+//~^ ERROR type `diamond_priv_dep::SharedInType` from private dependency 'diamond_priv_dep' in public interface
+}
+
+pub struct PubInStruct {
+    pub f: diamond_pub_dep::SharedInType
+}
diff --git a/tests/ui/privacy/pub-priv-dep/diamond_deps.stderr b/tests/ui/privacy/pub-priv-dep/diamond_deps.stderr
new file mode 100644
index 0000000000000..8a6d35a747b63
--- /dev/null
+++ b/tests/ui/privacy/pub-priv-dep/diamond_deps.stderr
@@ -0,0 +1,14 @@
+error: type `diamond_priv_dep::SharedInType` from private dependency 'diamond_priv_dep' in public interface
+  --> $DIR/diamond_deps.rs:42:5
+   |
+LL |     pub f: diamond_priv_dep::SharedInType
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: the lint level is defined here
+  --> $DIR/diamond_deps.rs:27:9
+   |
+LL | #![deny(exported_private_dependencies)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/privacy/pub-priv-dep/pub-priv1.rs b/tests/ui/privacy/pub-priv-dep/pub-priv1.rs
index f26dbb47ba5e9..112eaf528be27 100644
--- a/tests/ui/privacy/pub-priv-dep/pub-priv1.rs
+++ b/tests/ui/privacy/pub-priv-dep/pub-priv1.rs
@@ -1,12 +1,20 @@
 //@ aux-crate:priv:priv_dep=priv_dep.rs
 //@ aux-build:pub_dep.rs
+//@ aux-crate:priv:pm=pm.rs
 //@ compile-flags: -Zunstable-options
+
+// Basic behavior check of exported_private_dependencies from either a public
+// dependency or a private one.
+
 #![deny(exported_private_dependencies)]
 
 // This crate is a private dependency
-extern crate priv_dep;
+// FIXME: This should trigger.
+pub extern crate priv_dep;
 // This crate is a public dependency
 extern crate pub_dep;
+// This crate is a private dependency
+extern crate pm;
 
 use priv_dep::{OtherTrait, OtherType};
 use pub_dep::PubType;
@@ -25,7 +33,10 @@ pub struct PublicType {
 }
 
 impl PublicType {
-    pub fn pub_fn(param: OtherType) {}
+    pub fn pub_fn_param(param: OtherType) {}
+    //~^ ERROR type `OtherType` from private dependency 'priv_dep' in public interface
+
+    pub fn pub_fn_return() -> OtherType { OtherType }
     //~^ ERROR type `OtherType` from private dependency 'priv_dep' in public interface
 
     fn priv_fn(param: OtherType) {}
@@ -36,9 +47,61 @@ pub trait MyPubTrait {
 }
 //~^^ ERROR trait `OtherTrait` from private dependency 'priv_dep' in public interface
 
+pub trait WithSuperTrait: OtherTrait {}
+//~^ ERROR trait `OtherTrait` from private dependency 'priv_dep' in public interface
+
+pub trait PubLocalTraitWithAssoc {
+    type X;
+}
+
+pub struct PrivateAssoc;
+impl PubLocalTraitWithAssoc for PrivateAssoc {
+    type X = OtherType;
+//~^ ERROR type `OtherType` from private dependency 'priv_dep' in public interface
+}
+
+pub fn in_bounds<T: OtherTrait>(x: T) { unimplemented!() }
+//~^ ERROR trait `OtherTrait` from private dependency 'priv_dep' in public interface
+
+pub fn private_in_generic() -> std::num::Saturating<OtherType> { unimplemented!() }
+//~^ ERROR type `OtherType` from private dependency 'priv_dep' in public interface
+
+pub static STATIC: OtherType = OtherType;
+//~^ ERROR type `OtherType` from private dependency 'priv_dep' in public interface
+
+pub const CONST: OtherType = OtherType;
+//~^ ERROR type `OtherType` from private dependency 'priv_dep' in public interface
+
+pub type Alias = OtherType;
+//~^ ERROR type `OtherType` from private dependency 'priv_dep' in public interface
+
+pub struct PublicWithPrivateImpl;
+
+// FIXME: This should trigger.
+// See https://github.com/rust-lang/rust/issues/71043
+impl OtherTrait for PublicWithPrivateImpl {}
+
+pub trait PubTraitOnPrivate {}
+
+// FIXME: This should trigger.
+// See https://github.com/rust-lang/rust/issues/71043
+impl PubTraitOnPrivate for OtherType {}
+
 pub struct AllowedPrivType {
     #[allow(exported_private_dependencies)]
     pub allowed: OtherType,
 }
 
+// FIXME: This should trigger.
+pub use priv_dep::m;
+// FIXME: This should trigger.
+pub use pm::fn_like;
+// FIXME: This should trigger.
+pub use pm::PmDerive;
+// FIXME: This should trigger.
+pub use pm::pm_attr;
+
+// FIXME: This should trigger.
+pub use priv_dep::E::V1;
+
 fn main() {}
diff --git a/tests/ui/privacy/pub-priv-dep/pub-priv1.stderr b/tests/ui/privacy/pub-priv-dep/pub-priv1.stderr
index e62a440d8f568..53d461a5774a0 100644
--- a/tests/ui/privacy/pub-priv-dep/pub-priv1.stderr
+++ b/tests/ui/privacy/pub-priv-dep/pub-priv1.stderr
@@ -1,26 +1,74 @@
 error: type `OtherType` from private dependency 'priv_dep' in public interface
-  --> $DIR/pub-priv1.rs:21:5
+  --> $DIR/pub-priv1.rs:29:5
    |
 LL |     pub field: OtherType,
    |     ^^^^^^^^^^^^^^^^^^^^
    |
 note: the lint level is defined here
-  --> $DIR/pub-priv1.rs:4:9
+  --> $DIR/pub-priv1.rs:9:9
    |
 LL | #![deny(exported_private_dependencies)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: type `OtherType` from private dependency 'priv_dep' in public interface
-  --> $DIR/pub-priv1.rs:28:5
+  --> $DIR/pub-priv1.rs:36:5
    |
-LL |     pub fn pub_fn(param: OtherType) {}
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL |     pub fn pub_fn_param(param: OtherType) {}
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: type `OtherType` from private dependency 'priv_dep' in public interface
+  --> $DIR/pub-priv1.rs:39:5
+   |
+LL |     pub fn pub_fn_return() -> OtherType { OtherType }
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: trait `OtherTrait` from private dependency 'priv_dep' in public interface
-  --> $DIR/pub-priv1.rs:35:5
+  --> $DIR/pub-priv1.rs:46:5
    |
 LL |     type Foo: OtherTrait;
    |     ^^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to 3 previous errors
+error: trait `OtherTrait` from private dependency 'priv_dep' in public interface
+  --> $DIR/pub-priv1.rs:50:1
+   |
+LL | pub trait WithSuperTrait: OtherTrait {}
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: type `OtherType` from private dependency 'priv_dep' in public interface
+  --> $DIR/pub-priv1.rs:59:5
+   |
+LL |     type X = OtherType;
+   |     ^^^^^^
+
+error: trait `OtherTrait` from private dependency 'priv_dep' in public interface
+  --> $DIR/pub-priv1.rs:63:1
+   |
+LL | pub fn in_bounds<T: OtherTrait>(x: T) { unimplemented!() }
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: type `OtherType` from private dependency 'priv_dep' in public interface
+  --> $DIR/pub-priv1.rs:66:1
+   |
+LL | pub fn private_in_generic() -> std::num::Saturating<OtherType> { unimplemented!() }
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: type `OtherType` from private dependency 'priv_dep' in public interface
+  --> $DIR/pub-priv1.rs:69:1
+   |
+LL | pub static STATIC: OtherType = OtherType;
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: type `OtherType` from private dependency 'priv_dep' in public interface
+  --> $DIR/pub-priv1.rs:72:1
+   |
+LL | pub const CONST: OtherType = OtherType;
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: type `OtherType` from private dependency 'priv_dep' in public interface
+  --> $DIR/pub-priv1.rs:75:1
+   |
+LL | pub type Alias = OtherType;
+   | ^^^^^^^^^^^^^^
+
+error: aborting due to 11 previous errors
 
diff --git a/tests/ui/privacy/pub-priv-dep/reexport_from_priv.rs b/tests/ui/privacy/pub-priv-dep/reexport_from_priv.rs
new file mode 100644
index 0000000000000..3c6e9825e7288
--- /dev/null
+++ b/tests/ui/privacy/pub-priv-dep/reexport_from_priv.rs
@@ -0,0 +1,15 @@
+//@ aux-crate:priv:reexport=reexport.rs
+//@ compile-flags: -Zunstable-options
+//@ check-pass
+
+// Checks the behavior of a reexported item from a private dependency.
+
+#![crate_type = "lib"]
+#![deny(exported_private_dependencies)]
+
+extern crate reexport;
+
+// FIXME: This should trigger.
+pub fn leaks_priv() -> reexport::Shared {
+    reexport::Shared
+}
diff --git a/tests/ui/privacy/pub-priv-dep/shared_both_private.rs b/tests/ui/privacy/pub-priv-dep/shared_both_private.rs
new file mode 100644
index 0000000000000..20a4b85c01e8d
--- /dev/null
+++ b/tests/ui/privacy/pub-priv-dep/shared_both_private.rs
@@ -0,0 +1,32 @@
+//@ aux-crate:priv:shared=shared.rs
+//@ aux-crate:reexport=reexport.rs
+//@ compile-flags: -Zunstable-options
+//@ check-pass
+
+// A shared dependency, where a private dependency reexports a public dependency.
+//
+//         shared_both_private
+//                  /\
+//       (PRIVATE) /  | (PRIVATE)
+//                /   |
+//        reexport    |
+//                \   |
+//        (public) \  /
+//                  \/
+//                shared
+
+#![crate_type = "lib"]
+#![deny(exported_private_dependencies)]
+
+extern crate shared;
+extern crate reexport;
+
+// FIXME: This should trigger.
+pub fn leaks_priv() -> shared::Shared {
+    shared::Shared
+}
+
+// FIXME: This should trigger.
+pub fn leaks_priv_reexport() -> reexport::Shared {
+    reexport::Shared
+}
diff --git a/tests/ui/privacy/pub-priv-dep/shared_direct_private.rs b/tests/ui/privacy/pub-priv-dep/shared_direct_private.rs
new file mode 100644
index 0000000000000..b329a7acb5834
--- /dev/null
+++ b/tests/ui/privacy/pub-priv-dep/shared_direct_private.rs
@@ -0,0 +1,39 @@
+//@ aux-crate:priv:shared=shared.rs
+//@ aux-crate:reexport=reexport.rs
+//@ compile-flags: -Zunstable-options
+//@ check-pass
+
+// A shared dependency, where the public side reexports the same item as a
+// direct private dependency.
+//
+//          shared_direct_private
+//                  /\
+//        (public) /  | (PRIVATE)
+//                /   |
+//        reexport    |
+//                \   |
+//        (public) \  /
+//                  \/
+//                shared
+//
+
+#![crate_type = "lib"]
+#![deny(exported_private_dependencies)]
+
+extern crate shared;
+extern crate reexport;
+
+// FIXME: Should this trigger?
+//
+// One could make an argument that I said I want "reexport" to be public, and
+// since "reexport" says "shared_direct_private" is public, then it should
+// transitively be public for me. However, as written, this is explicitly
+// referring to a dependency that is marked "private", which I think is
+// confusing.
+pub fn leaks_priv() -> shared::Shared {
+    shared::Shared
+}
+
+pub fn leaks_pub() -> reexport::Shared {
+    reexport::Shared
+}
diff --git a/tests/ui/privacy/pub-priv-dep/shared_indirect.rs b/tests/ui/privacy/pub-priv-dep/shared_indirect.rs
new file mode 100644
index 0000000000000..34b624b4a1a40
--- /dev/null
+++ b/tests/ui/privacy/pub-priv-dep/shared_indirect.rs
@@ -0,0 +1,29 @@
+//@ aux-crate:priv:shared=shared.rs
+//@ aux-crate:priv:indirect1=indirect1.rs
+//@ compile-flags: -Zunstable-options
+//@ check-pass
+
+// A shared dependency, where it is only indirectly public.
+//
+//            shared_indirect
+//                  /\
+//       (PRIVATE) /  | (PRIVATE)
+//                /   |
+//     indirect1 |    |
+//     (PRIVATE) |    |
+//     indirect2 |    |
+//                \   |
+//        (public) \  /
+//                  \/
+//                shared
+
+#![crate_type = "lib"]
+#![deny(exported_private_dependencies)]
+
+extern crate shared;
+extern crate indirect1;
+
+// FIXME: This should trigger.
+pub fn leaks_priv() -> shared::Shared {
+    shared::Shared
+}

From 5f4424bfaf6fc9c66df6e19a3f5e96b0fc9a1441 Mon Sep 17 00:00:00 2001
From: Nicholas Nethercote <n.nethercote@gmail.com>
Date: Mon, 13 May 2024 08:59:02 +1000
Subject: [PATCH 20/21] Handle `ReVar` in `note_and_explain_region`.

PR #124918 made this path abort. The added test, from fuzzing,
identified that it is reachable.
---
 .../rustc_infer/src/infer/error_reporting/mod.rs    |  5 ++++-
 tests/ui/inference/note-and-explain-ReVar-124973.rs |  8 ++++++++
 .../inference/note-and-explain-ReVar-124973.stderr  | 13 +++++++++++++
 3 files changed, 25 insertions(+), 1 deletion(-)
 create mode 100644 tests/ui/inference/note-and-explain-ReVar-124973.rs
 create mode 100644 tests/ui/inference/note-and-explain-ReVar-124973.stderr

diff --git a/compiler/rustc_infer/src/infer/error_reporting/mod.rs b/compiler/rustc_infer/src/infer/error_reporting/mod.rs
index 46a7e7b239965..e0894ed31bfc3 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/mod.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/mod.rs
@@ -173,7 +173,10 @@ pub(super) fn note_and_explain_region<'tcx>(
 
         ty::ReError(_) => return,
 
-        ty::ReVar(_) | ty::ReBound(..) | ty::ReErased => {
+        // FIXME(#125431): `ReVar` shouldn't reach here.
+        ty::ReVar(_) => (format!("lifetime `{region}`"), alt_span),
+
+        ty::ReBound(..) | ty::ReErased => {
             bug!("unexpected region for note_and_explain_region: {:?}", region);
         }
     };
diff --git a/tests/ui/inference/note-and-explain-ReVar-124973.rs b/tests/ui/inference/note-and-explain-ReVar-124973.rs
new file mode 100644
index 0000000000000..f1e2464563699
--- /dev/null
+++ b/tests/ui/inference/note-and-explain-ReVar-124973.rs
@@ -0,0 +1,8 @@
+//@ edition:2018
+
+#![feature(c_variadic)]
+
+async unsafe extern "C" fn multiple_named_lifetimes<'a, 'b>(_: u8, ...) {}
+//~^ ERROR hidden type for `impl Future<Output = ()>` captures lifetime that does not appear in bounds
+
+fn main() {}
diff --git a/tests/ui/inference/note-and-explain-ReVar-124973.stderr b/tests/ui/inference/note-and-explain-ReVar-124973.stderr
new file mode 100644
index 0000000000000..574f6508e4c78
--- /dev/null
+++ b/tests/ui/inference/note-and-explain-ReVar-124973.stderr
@@ -0,0 +1,13 @@
+error[E0700]: hidden type for `impl Future<Output = ()>` captures lifetime that does not appear in bounds
+  --> $DIR/note-and-explain-ReVar-124973.rs:5:73
+   |
+LL | async unsafe extern "C" fn multiple_named_lifetimes<'a, 'b>(_: u8, ...) {}
+   | ----------------------------------------------------------------------- ^^
+   | |
+   | opaque type defined here
+   |
+   = note: hidden type `{async fn body of multiple_named_lifetimes<'a, 'b>()}` captures lifetime `'_`
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0700`.

From ddb81ce68047d6383a789c8da514e443faea8349 Mon Sep 17 00:00:00 2001
From: Oneirical <manchot@videotron.ca>
Date: Fri, 17 May 2024 15:05:36 -0400
Subject: [PATCH 21/21] rewrite and rename issue-46239

---
 src/tools/run-make-support/src/rustc.rs       |  6 ++++++
 .../tidy/src/allowed_run_make_makefiles.txt   |  1 -
 tests/codegen/noalias-freeze.rs               | 21 +++++++++++++++++++
 tests/run-make/issue-46239/Makefile           |  6 ------
 tests/run-make/issue-46239/main.rs            |  8 -------
 5 files changed, 27 insertions(+), 15 deletions(-)
 create mode 100644 tests/codegen/noalias-freeze.rs
 delete mode 100644 tests/run-make/issue-46239/Makefile
 delete mode 100644 tests/run-make/issue-46239/main.rs

diff --git a/src/tools/run-make-support/src/rustc.rs b/src/tools/run-make-support/src/rustc.rs
index d034826a830b4..f581204d5f1cb 100644
--- a/src/tools/run-make-support/src/rustc.rs
+++ b/src/tools/run-make-support/src/rustc.rs
@@ -64,6 +64,12 @@ impl Rustc {
         self
     }
 
+    /// Specify a specific optimization level.
+    pub fn opt_level(&mut self, option: &str) -> &mut Self {
+        self.cmd.arg(format!("-Copt-level={option}"));
+        self
+    }
+
     /// Specify type(s) of output files to generate.
     pub fn emit(&mut self, kinds: &str) -> &mut Self {
         self.cmd.arg(format!("--emit={kinds}"));
diff --git a/src/tools/tidy/src/allowed_run_make_makefiles.txt b/src/tools/tidy/src/allowed_run_make_makefiles.txt
index 1a3d6f8d81360..379d07ed22ded 100644
--- a/src/tools/tidy/src/allowed_run_make_makefiles.txt
+++ b/src/tools/tidy/src/allowed_run_make_makefiles.txt
@@ -112,7 +112,6 @@ run-make/issue-37839/Makefile
 run-make/issue-37893/Makefile
 run-make/issue-38237/Makefile
 run-make/issue-40535/Makefile
-run-make/issue-46239/Makefile
 run-make/issue-47384/Makefile
 run-make/issue-47551/Makefile
 run-make/issue-51671/Makefile
diff --git a/tests/codegen/noalias-freeze.rs b/tests/codegen/noalias-freeze.rs
new file mode 100644
index 0000000000000..8086f3afbbc87
--- /dev/null
+++ b/tests/codegen/noalias-freeze.rs
@@ -0,0 +1,21 @@
+//@ compile-flags: -Copt-level=1
+
+// References returned by a Frozen pointer type
+// could be marked as "noalias", which caused miscompilation errors.
+// This test runs the most minimal possible code that can reproduce this bug,
+// and checks that noalias does not appear.
+// See https://github.com/rust-lang/rust/issues/46239
+
+#![crate_type = "lib"]
+
+fn project<T>(x: &(T,)) -> &T { &x.0 }
+
+fn dummy() {}
+
+// CHECK-LABEL: @foo(
+// CHECK-NOT: noalias
+#[no_mangle]
+pub fn foo() {
+    let f = (dummy as fn(),);
+    (*project(&f))();
+}
diff --git a/tests/run-make/issue-46239/Makefile b/tests/run-make/issue-46239/Makefile
deleted file mode 100644
index 0006ced25156a..0000000000000
--- a/tests/run-make/issue-46239/Makefile
+++ /dev/null
@@ -1,6 +0,0 @@
-# ignore-cross-compile
-include ../tools.mk
-
-all:
-	$(RUSTC) main.rs -C opt-level=1
-	$(call RUN,main)
diff --git a/tests/run-make/issue-46239/main.rs b/tests/run-make/issue-46239/main.rs
deleted file mode 100644
index b7df5cf4d8128..0000000000000
--- a/tests/run-make/issue-46239/main.rs
+++ /dev/null
@@ -1,8 +0,0 @@
-fn project<T>(x: &(T,)) -> &T { &x.0 }
-
-fn dummy() {}
-
-fn main() {
-    let f = (dummy as fn(),);
-    (*project(&f))();
-}