Auto merge of #2607 - RalfJung:rustup, r=RalfJung

Rustup

9 files changed, 86 insertions, 113 deletions

diff --git a/compiler/rustc_mir_transform/src/check_const_item_mutation.rs b/compiler/rustc_mir_transform/src/check_const_item_mutation.rs
index 8838b14c53a..fa5f392fa74 100644
--- a/compiler/rustc_mir_transform/src/check_const_item_mutation.rs
+++ b/compiler/rustc_mir_transform/src/check_const_item_mutation.rs
@@ -1,4 +1,4 @@
-use rustc_errors::{DiagnosticBuilder, LintDiagnosticBuilder};
+use rustc_errors::{DiagnosticBuilder, DiagnosticMessage};
 use rustc_middle::mir::visit::Visitor;
 use rustc_middle::mir::*;
 use rustc_middle::ty::TyCtxt;
@@ -63,7 +63,10 @@ impl<'tcx> ConstMutationChecker<'_, 'tcx> {
         place: &Place<'tcx>,
         const_item: DefId,
         location: Location,
-        decorate: impl for<'b> FnOnce(LintDiagnosticBuilder<'b, ()>) -> DiagnosticBuilder<'b, ()>,
+        msg: impl Into<DiagnosticMessage>,
+        decorate: impl for<'a, 'b> FnOnce(
+            &'a mut DiagnosticBuilder<'b, ()>,
+        ) -> &'a mut DiagnosticBuilder<'b, ()>,
     ) {
         // Don't lint on borrowing/assigning when a dereference is involved.
         // If we 'leave' the temporary via a dereference, we must
@@ -84,10 +87,10 @@ impl<'tcx> ConstMutationChecker<'_, 'tcx> {
                 CONST_ITEM_MUTATION,
                 lint_root,
                 source_info.span,
+                msg,
                 |lint| {
                     decorate(lint)
                         .span_note(self.tcx.def_span(const_item), "`const` item defined here")
-                        .emit();
                 },
             );
         }
@@ -102,10 +105,8 @@ impl<'tcx> Visitor<'tcx> for ConstMutationChecker<'_, 'tcx> {
             // so emitting a lint would be redundant.
             if !lhs.projection.is_empty() {
                 if let Some(def_id) = self.is_const_item_without_destructor(lhs.local) {
-                    self.lint_const_item_usage(&lhs, def_id, loc, |lint| {
-                        let mut lint = lint.build("attempting to modify a `const` item");
-                        lint.note("each usage of a `const` item creates a new temporary; the original `const` item will not be modified");
-                        lint
+                    self.lint_const_item_usage(&lhs, def_id, loc, "attempting to modify a `const` item",|lint| {
+                        lint.note("each usage of a `const` item creates a new temporary; the original `const` item will not be modified")
                     })
                 }
             }
@@ -137,8 +138,7 @@ impl<'tcx> Visitor<'tcx> for ConstMutationChecker<'_, 'tcx> {
                 });
                 let lint_loc =
                     if method_did.is_some() { self.body.terminator_loc(loc.block) } else { loc };
-                self.lint_const_item_usage(place, def_id, lint_loc, |lint| {
-                    let mut lint = lint.build("taking a mutable reference to a `const` item");
+                self.lint_const_item_usage(place, def_id, lint_loc, "taking a mutable reference to a `const` item", |lint| {
                     lint
                         .note("each usage of a `const` item creates a new temporary")
                         .note("the mutable reference will refer to this temporary, not the original `const` item");
diff --git a/compiler/rustc_mir_transform/src/check_packed_ref.rs b/compiler/rustc_mir_transform/src/check_packed_ref.rs
index 3b7ba3f9a67..51abcf51189 100644
--- a/compiler/rustc_mir_transform/src/check_packed_ref.rs
+++ b/compiler/rustc_mir_transform/src/check_packed_ref.rs
@@ -33,21 +33,27 @@ struct PackedRefChecker<'a, 'tcx> {
 fn unsafe_derive_on_repr_packed(tcx: TyCtxt<'_>, def_id: LocalDefId) {
     let lint_hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
 
-    tcx.struct_span_lint_hir(UNALIGNED_REFERENCES, lint_hir_id, tcx.def_span(def_id), |lint| {
-        // FIXME: when we make this a hard error, this should have its
-        // own error code.
-        let extra = if tcx.generics_of(def_id).own_requires_monomorphization() {
-            "with type or const parameters"
-        } else {
-            "that does not derive `Copy`"
-        };
-        let message = format!(
-            "`{}` can't be derived on this `#[repr(packed)]` struct {}",
-            tcx.item_name(tcx.trait_id_of_impl(def_id.to_def_id()).expect("derived trait name")),
-            extra
-        );
-        lint.build(message).emit();
-    });
+    // FIXME: when we make this a hard error, this should have its
+    // own error code.
+
+    let extra = if tcx.generics_of(def_id).own_requires_monomorphization() {
+        "with type or const parameters"
+    } else {
+        "that does not derive `Copy`"
+    };
+    let message = format!(
+        "`{}` can't be derived on this `#[repr(packed)]` struct {}",
+        tcx.item_name(tcx.trait_id_of_impl(def_id.to_def_id()).expect("derived trait name")),
+        extra
+    );
+
+    tcx.struct_span_lint_hir(
+        UNALIGNED_REFERENCES,
+        lint_hir_id,
+        tcx.def_span(def_id),
+        message,
+        |lint| lint,
+    );
 }
 
 impl<'tcx> Visitor<'tcx> for PackedRefChecker<'_, 'tcx> {
@@ -86,8 +92,9 @@ impl<'tcx> Visitor<'tcx> for PackedRefChecker<'_, 'tcx> {
                         UNALIGNED_REFERENCES,
                         lint_root,
                         source_info.span,
+                        "reference to packed field is unaligned",
                         |lint| {
-                            lint.build("reference to packed field is unaligned")
+                            lint
                                 .note(
                                     "fields of packed structs are not properly aligned, and creating \
                                     a misaligned reference is undefined behavior (even if that \
@@ -98,7 +105,6 @@ impl<'tcx> Visitor<'tcx> for PackedRefChecker<'_, 'tcx> {
                                     reference with a raw pointer and use `read_unaligned`/`write_unaligned` \
                                     (loads and stores via `*p` must be properly aligned even when using raw pointers)"
                                 )
-                                .emit();
                         },
                     );
                 }
diff --git a/compiler/rustc_mir_transform/src/check_unsafety.rs b/compiler/rustc_mir_transform/src/check_unsafety.rs
index beff19a3ab2..4730be1244b 100644
--- a/compiler/rustc_mir_transform/src/check_unsafety.rs
+++ b/compiler/rustc_mir_transform/src/check_unsafety.rs
@@ -489,21 +489,20 @@ fn unsafety_check_result<'tcx>(
 
 fn report_unused_unsafe(tcx: TyCtxt<'_>, kind: UnusedUnsafe, id: HirId) {
     let span = tcx.sess.source_map().guess_head_span(tcx.hir().span(id));
-    tcx.struct_span_lint_hir(UNUSED_UNSAFE, id, span, |lint| {
-        let msg = "unnecessary `unsafe` block";
-        let mut db = lint.build(msg);
-        db.span_label(span, msg);
+    let msg = "unnecessary `unsafe` block";
+    tcx.struct_span_lint_hir(UNUSED_UNSAFE, id, span, msg, |lint| {
+        lint.span_label(span, msg);
         match kind {
             UnusedUnsafe::Unused => {}
             UnusedUnsafe::InUnsafeBlock(id) => {
-                db.span_label(
+                lint.span_label(
                     tcx.sess.source_map().guess_head_span(tcx.hir().span(id)),
                     "because it's nested under this `unsafe` block",
                 );
             }
         }
 
-        db.emit();
+        lint
     });
 }
 
@@ -543,15 +542,8 @@ pub fn check_unsafety(tcx: TyCtxt<'_>, def_id: LocalDefId) {
                 UNSAFE_OP_IN_UNSAFE_FN,
                 lint_root,
                 source_info.span,
-                |lint| {
-                    lint.build(&format!(
-                        "{} is unsafe and requires unsafe block (error E0133)",
-                        description,
-                    ))
-                    .span_label(source_info.span, description)
-                    .note(note)
-                    .emit();
-                },
+                format!("{} is unsafe and requires unsafe block (error E0133)", description,),
+                |lint| lint.span_label(source_info.span, description).note(note),
             ),
         }
     }
diff --git a/compiler/rustc_mir_transform/src/const_prop_lint.rs b/compiler/rustc_mir_transform/src/const_prop_lint.rs
index 2885f06b19c..6bddbdb8e6a 100644
--- a/compiler/rustc_mir_transform/src/const_prop_lint.rs
+++ b/compiler/rustc_mir_transform/src/const_prop_lint.rs
@@ -16,9 +16,9 @@ use rustc_index::bit_set::BitSet;
 use rustc_index::vec::IndexVec;
 use rustc_middle::mir::visit::Visitor;
 use rustc_middle::mir::{
-    AssertKind, BinOp, Body, Constant, ConstantKind, Local, LocalDecl, Location, Operand, Place,
-    Rvalue, SourceInfo, SourceScope, SourceScopeData, Statement, StatementKind, Terminator,
-    TerminatorKind, UnOp, RETURN_PLACE,
+    AssertKind, BinOp, Body, Constant, Local, LocalDecl, Location, Operand, Place, Rvalue,
+    SourceInfo, SourceScope, SourceScopeData, Statement, StatementKind, Terminator, TerminatorKind,
+    UnOp, RETURN_PLACE,
 };
 use rustc_middle::ty::layout::{LayoutError, LayoutOf, LayoutOfHelpers, TyAndLayout};
 use rustc_middle::ty::InternalSubsts;
@@ -286,7 +286,11 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
     }
 
     /// Returns the value, if any, of evaluating `c`.
-    fn eval_constant(&mut self, c: &Constant<'tcx>, source_info: SourceInfo) -> Option<OpTy<'tcx>> {
+    fn eval_constant(
+        &mut self,
+        c: &Constant<'tcx>,
+        _source_info: SourceInfo,
+    ) -> Option<OpTy<'tcx>> {
         // FIXME we need to revisit this for #67176
         if c.needs_subst() {
             return None;
@@ -297,28 +301,7 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
             Err(error) => {
                 let tcx = self.ecx.tcx.at(c.span);
                 let err = ConstEvalErr::new(&self.ecx, error, Some(c.span));
-                if let Some(lint_root) = self.lint_root(source_info) {
-                    let lint_only = match c.literal {
-                        ConstantKind::Ty(ct) => ct.needs_subst(),
-                        ConstantKind::Unevaluated(
-                            ty::Unevaluated { def: _, substs: _, promoted: Some(_) },
-                            _,
-                        ) => {
-                            // Promoteds must lint and not error as the user didn't ask for them
-                            true
-                        }
-                        ConstantKind::Unevaluated(..) | ConstantKind::Val(..) => c.needs_subst(),
-                    };
-                    if lint_only {
-                        // Out of backwards compatibility we cannot report hard errors in unused
-                        // generic functions using associated constants of the generic parameters.
-                        err.report_as_lint(tcx, "erroneous constant used", lint_root, Some(c.span));
-                    } else {
-                        err.report_as_error(tcx, "erroneous constant used");
-                    }
-                } else {
-                    err.report_as_error(tcx, "erroneous constant used");
-                }
+                err.report_as_error(tcx, "erroneous constant used");
                 None
             }
         }
@@ -347,10 +330,8 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
         panic: AssertKind<impl std::fmt::Debug>,
     ) {
         if let Some(lint_root) = self.lint_root(source_info) {
-            self.tcx.struct_span_lint_hir(lint, lint_root, source_info.span, |lint| {
-                let mut err = lint.build(message);
-                err.span_label(source_info.span, format!("{:?}", panic));
-                err.emit();
+            self.tcx.struct_span_lint_hir(lint, lint_root, source_info.span, message, |lint| {
+                lint.span_label(source_info.span, format!("{:?}", panic))
             });
         }
     }
diff --git a/compiler/rustc_mir_transform/src/coverage/test_macros/Cargo.toml b/compiler/rustc_mir_transform/src/coverage/test_macros/Cargo.toml
index f5e8b65656a..f753caa9124 100644
--- a/compiler/rustc_mir_transform/src/coverage/test_macros/Cargo.toml
+++ b/compiler/rustc_mir_transform/src/coverage/test_macros/Cargo.toml
@@ -5,4 +5,3 @@ edition = "2021"
 
 [lib]
 proc-macro = true
-doctest = false
diff --git a/compiler/rustc_mir_transform/src/ffi_unwind_calls.rs b/compiler/rustc_mir_transform/src/ffi_unwind_calls.rs
index 7522a50a8c6..1244c18020d 100644
--- a/compiler/rustc_mir_transform/src/ffi_unwind_calls.rs
+++ b/compiler/rustc_mir_transform/src/ffi_unwind_calls.rs
@@ -106,14 +106,12 @@ fn has_ffi_unwind_calls(tcx: TyCtxt<'_>, local_def_id: LocalDefId) -> bool {
                 .lint_root;
             let span = terminator.source_info.span;
 
-            tcx.struct_span_lint_hir(FFI_UNWIND_CALLS, lint_root, span, |lint| {
-                let msg = match fn_def_id {
-                    Some(_) => "call to foreign function with FFI-unwind ABI",
-                    None => "call to function pointer with FFI-unwind ABI",
-                };
-                let mut db = lint.build(msg);
-                db.span_label(span, msg);
-                db.emit();
+            let msg = match fn_def_id {
+                Some(_) => "call to foreign function with FFI-unwind ABI",
+                None => "call to function pointer with FFI-unwind ABI",
+            };
+            tcx.struct_span_lint_hir(FFI_UNWIND_CALLS, lint_root, span, msg, |lint| {
+                lint.span_label(span, msg)
             });
 
             tainted = true;
diff --git a/compiler/rustc_mir_transform/src/function_item_references.rs b/compiler/rustc_mir_transform/src/function_item_references.rs
index 0568eb2ffa6..469566694a3 100644
--- a/compiler/rustc_mir_transform/src/function_item_references.rs
+++ b/compiler/rustc_mir_transform/src/function_item_references.rs
@@ -179,11 +179,15 @@ impl<'tcx> FunctionItemRefChecker<'_, 'tcx> {
         let num_args = fn_sig.inputs().map_bound(|inputs| inputs.len()).skip_binder();
         let variadic = if fn_sig.c_variadic() { ", ..." } else { "" };
         let ret = if fn_sig.output().skip_binder().is_unit() { "" } else { " -> _" };
-        self.tcx.struct_span_lint_hir(FUNCTION_ITEM_REFERENCES, lint_root, span, |lint| {
-            lint.build("taking a reference to a function item does not give a function pointer")
-                .span_suggestion(
+        self.tcx.struct_span_lint_hir(
+            FUNCTION_ITEM_REFERENCES,
+            lint_root,
+            span,
+            "taking a reference to a function item does not give a function pointer",
+            |lint| {
+                lint.span_suggestion(
                     span,
-                    &format!("cast `{}` to obtain a function pointer", ident),
+                    format!("cast `{}` to obtain a function pointer", ident),
                     format!(
                         "{} as {}{}fn({}{}){}",
                         if params.is_empty() { ident } else { format!("{}::<{}>", ident, params) },
@@ -195,7 +199,7 @@ impl<'tcx> FunctionItemRefChecker<'_, 'tcx> {
                     ),
                     Applicability::Unspecified,
                 )
-                .emit();
-        });
+            },
+        );
     }
 }
diff --git a/compiler/rustc_mir_transform/src/inline.rs b/compiler/rustc_mir_transform/src/inline.rs
index b60bd3cea23..780b91d9215 100644
--- a/compiler/rustc_mir_transform/src/inline.rs
+++ b/compiler/rustc_mir_transform/src/inline.rs
@@ -605,7 +605,7 @@ impl<'tcx> Inliner<'tcx> {
                 caller_body.required_consts.extend(
                     callee_body.required_consts.iter().copied().filter(|&ct| match ct.literal {
                         ConstantKind::Ty(_) => {
-                            bug!("should never encounter ty::Unevaluated in `required_consts`")
+                            bug!("should never encounter ty::UnevaluatedConst in `required_consts`")
                         }
                         ConstantKind::Val(..) | ConstantKind::Unevaluated(..) => true,
                     }),
@@ -977,6 +977,21 @@ impl Integrator<'_, '_> {
         trace!("mapping block `{:?}` to `{:?}`", block, new);
         new
     }
+
+    fn map_unwind(&self, unwind: Option<BasicBlock>) -> Option<BasicBlock> {
+        if self.in_cleanup_block {
+            if unwind.is_some() {
+                bug!("cleanup on cleanup block");
+            }
+            return unwind;
+        }
+
+        match unwind {
+            Some(target) => Some(self.map_block(target)),
+            // Add an unwind edge to the original call's cleanup block
+            None => self.cleanup_block,
+        }
+    }
 }
 
 impl<'tcx> MutVisitor<'tcx> for Integrator<'_, 'tcx> {
@@ -1085,35 +1100,17 @@ impl<'tcx> MutVisitor<'tcx> for Integrator<'_, 'tcx> {
             TerminatorKind::Drop { ref mut target, ref mut unwind, .. }
             | TerminatorKind::DropAndReplace { ref mut target, ref mut unwind, .. } => {
                 *target = self.map_block(*target);
-                if let Some(tgt) = *unwind {
-                    *unwind = Some(self.map_block(tgt));
-                } else if !self.in_cleanup_block {
-                    // Unless this drop is in a cleanup block, add an unwind edge to
-                    // the original call's cleanup block
-                    *unwind = self.cleanup_block;
-                }
+                *unwind = self.map_unwind(*unwind);
             }
             TerminatorKind::Call { ref mut target, ref mut cleanup, .. } => {
                 if let Some(ref mut tgt) = *target {
                     *tgt = self.map_block(*tgt);
                 }
-                if let Some(tgt) = *cleanup {
-                    *cleanup = Some(self.map_block(tgt));
-                } else if !self.in_cleanup_block {
-                    // Unless this call is in a cleanup block, add an unwind edge to
-                    // the original call's cleanup block
-                    *cleanup = self.cleanup_block;
-                }
+                *cleanup = self.map_unwind(*cleanup);
             }
             TerminatorKind::Assert { ref mut target, ref mut cleanup, .. } => {
                 *target = self.map_block(*target);
-                if let Some(tgt) = *cleanup {
-                    *cleanup = Some(self.map_block(tgt));
-                } else if !self.in_cleanup_block {
-                    // Unless this assert is in a cleanup block, add an unwind edge to
-                    // the original call's cleanup block
-                    *cleanup = self.cleanup_block;
-                }
+                *cleanup = self.map_unwind(*cleanup);
             }
             TerminatorKind::Return => {
                 terminator.kind = if let Some(tgt) = self.callsite.target {
@@ -1141,11 +1138,8 @@ impl<'tcx> MutVisitor<'tcx> for Integrator<'_, 'tcx> {
             TerminatorKind::InlineAsm { ref mut destination, ref mut cleanup, .. } => {
                 if let Some(ref mut tgt) = *destination {
                     *tgt = self.map_block(*tgt);
-                } else if !self.in_cleanup_block {
-                    // Unless this inline asm is in a cleanup block, add an unwind edge to
-                    // the original call's cleanup block
-                    *cleanup = self.cleanup_block;
                 }
+                *cleanup = self.map_unwind(*cleanup);
             }
         }
     }
diff --git a/compiler/rustc_mir_transform/src/lib.rs b/compiler/rustc_mir_transform/src/lib.rs
index e6fc8559571..2230c3399f0 100644
--- a/compiler/rustc_mir_transform/src/lib.rs
+++ b/compiler/rustc_mir_transform/src/lib.rs
@@ -1,7 +1,6 @@
 #![allow(rustc::potential_query_instability)]
 #![feature(box_patterns)]
 #![feature(let_chains)]
-#![cfg_attr(bootstrap, feature(let_else))]
 #![feature(map_try_insert)]
 #![feature(min_specialization)]
 #![feature(never_type)]