Auto merge of rust-lang#126679 - fmease:rollup-njrv2py, r=fmease

Rollup of 6 pull requests

Successful merges:

 - rust-lang#125447 (Allow constraining opaque types during subtyping in the trait system)
 - rust-lang#125766 (MCDC Coverage: instrument last boolean RHS operands from condition coverage)
 - rust-lang#125880 (Remove `src/tools/rust-demangler`)
 - rust-lang#126154 (StorageLive: refresh storage (instead of UB) when local is already live)
 - rust-lang#126572 (override user defined channel when using precompiled rustc)
 - rust-lang#126662 (Unconditionally warn on usage of `wasm32-wasi`)

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

Diff for: Cargo.lock

@@ -3479,14 +3479,6 @@ dependencies = [
  "wasmparser",
 ]
 
-[[package]]
-name = "rust-demangler"
-version = "0.0.1"
-dependencies = [
- "regex",
- "rustc-demangle",
-]
-
 [[package]]
 name = "rustbook"
 version = "0.1.0"

Diff for: Cargo.toml

@@ -23,7 +23,6 @@ members = [
   "src/tools/remote-test-client",
   "src/tools/remote-test-server",
   "src/tools/rust-installer",
-  "src/tools/rust-demangler",
   "src/tools/rustdoc",
   "src/tools/rls",
   "src/tools/rustfmt",

Diff for: compiler/rustc_const_eval/messages.ftl

@@ -73,8 +73,6 @@ const_eval_division_by_zero =
     dividing by zero
 const_eval_division_overflow =
     overflow in signed division (dividing MIN by -1)
-const_eval_double_storage_live =
-    StorageLive on a local that was already live
 
 const_eval_dyn_call_not_a_method =
     `dyn` call trying to call something that is not a method

Diff for: compiler/rustc_const_eval/src/interpret/eval_context.rs

@@ -1100,11 +1100,9 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
             Operand::Immediate(Immediate::Uninit)
         });
 
-        // StorageLive expects the local to be dead, and marks it live.
+        // If the local is already live, deallocate its old memory.
         let old = mem::replace(&mut self.frame_mut().locals[local].value, local_val);
-        if !matches!(old, LocalValue::Dead) {
-            throw_ub_custom!(fluent::const_eval_double_storage_live);
-        }
+        self.deallocate_local(old)?;
         Ok(())
     }
 
@@ -1118,7 +1116,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
         assert!(local != mir::RETURN_PLACE, "Cannot make return place dead");
         trace!("{:?} is now dead", local);
 
-        // It is entirely okay for this local to be already dead (at least that's how we currently generate MIR)
+        // If the local is already dead, this is a NOP.
         let old = mem::replace(&mut self.frame_mut().locals[local].value, LocalValue::Dead);
         self.deallocate_local(old)?;
         Ok(())

Diff for: compiler/rustc_infer/src/infer/mod.rs

@@ -878,9 +878,9 @@ impl<'tcx> InferCtxt<'tcx> {
 
         self.enter_forall(predicate, |ty::SubtypePredicate { a_is_expected, a, b }| {
             if a_is_expected {
-                Ok(self.at(cause, param_env).sub(DefineOpaqueTypes::No, a, b))
+                Ok(self.at(cause, param_env).sub(DefineOpaqueTypes::Yes, a, b))
             } else {
-                Ok(self.at(cause, param_env).sup(DefineOpaqueTypes::No, b, a))
+                Ok(self.at(cause, param_env).sup(DefineOpaqueTypes::Yes, b, a))
             }
         })
     }

Diff for: compiler/rustc_middle/src/mir/syntax.rs

@@ -361,16 +361,19 @@ pub enum StatementKind<'tcx> {
     /// At any point during the execution of a function, each local is either allocated or
     /// unallocated. Except as noted below, all locals except function parameters are initially
     /// unallocated. `StorageLive` statements cause memory to be allocated for the local while
-    /// `StorageDead` statements cause the memory to be freed. Using a local in any way (not only
-    /// reading/writing from it) while it is unallocated is UB.
+    /// `StorageDead` statements cause the memory to be freed. In other words,
+    /// `StorageLive`/`StorageDead` act like the heap operations `allocate`/`deallocate`, but for
+    /// stack-allocated local variables. Using a local in any way (not only reading/writing from it)
+    /// while it is unallocated is UB.
     ///
     /// Some locals have no `StorageLive` or `StorageDead` statements within the entire MIR body.
     /// These locals are implicitly allocated for the full duration of the function. There is a
     /// convenience method at `rustc_mir_dataflow::storage::always_storage_live_locals` for
     /// computing these locals.
     ///
-    /// If the local is already allocated, calling `StorageLive` again is UB. However, for an
-    /// unallocated local an additional `StorageDead` all is simply a nop.
+    /// If the local is already allocated, calling `StorageLive` again will implicitly free the
+    /// local and then allocate fresh uninitilized memory. If a local is already deallocated,
+    /// calling `StorageDead` again is a NOP.
     StorageLive(Local),
 
     /// See `StorageLive` above.

Diff for: compiler/rustc_mir_build/src/build/coverageinfo.rs

@@ -118,17 +118,35 @@ impl BranchInfoBuilder {
         }
     }
 
-    fn add_two_way_branch<'tcx>(
+    fn register_two_way_branch<'tcx>(
         &mut self,
+        tcx: TyCtxt<'tcx>,
         cfg: &mut CFG<'tcx>,
         source_info: SourceInfo,
         true_block: BasicBlock,
         false_block: BasicBlock,
     ) {
-        let true_marker = self.markers.inject_block_marker(cfg, source_info, true_block);
-        let false_marker = self.markers.inject_block_marker(cfg, source_info, false_block);
-
-        self.branch_spans.push(BranchSpan { span: source_info.span, true_marker, false_marker });
+        // Separate path for handling branches when MC/DC is enabled.
+        if let Some(mcdc_info) = self.mcdc_info.as_mut() {
+            let inject_block_marker =
+                |source_info, block| self.markers.inject_block_marker(cfg, source_info, block);
+            mcdc_info.visit_evaluated_condition(
+                tcx,
+                source_info,
+                true_block,
+                false_block,
+                inject_block_marker,
+            );
+        } else {
+            let true_marker = self.markers.inject_block_marker(cfg, source_info, true_block);
+            let false_marker = self.markers.inject_block_marker(cfg, source_info, false_block);
+
+            self.branch_spans.push(BranchSpan {
+                span: source_info.span,
+                true_marker,
+                false_marker,
+            });
+        }
     }
 
     pub(crate) fn into_done(self) -> Option<Box<mir::coverage::BranchInfo>> {
@@ -205,7 +223,14 @@ impl<'tcx> Builder<'_, 'tcx> {
             mir::TerminatorKind::if_(mir::Operand::Copy(place), true_block, false_block),
         );
 
-        branch_info.add_two_way_branch(&mut self.cfg, source_info, true_block, false_block);
+        // Separate path for handling branches when MC/DC is enabled.
+        branch_info.register_two_way_branch(
+            self.tcx,
+            &mut self.cfg,
+            source_info,
+            true_block,
+            false_block,
+        );
 
         let join_block = self.cfg.start_new_block();
         self.cfg.goto(true_block, source_info, join_block);
@@ -236,22 +261,13 @@ impl<'tcx> Builder<'_, 'tcx> {
 
         let source_info = SourceInfo { span: self.thir[expr_id].span, scope: self.source_scope };
 
-        // Separate path for handling branches when MC/DC is enabled.
-        if let Some(mcdc_info) = branch_info.mcdc_info.as_mut() {
-            let inject_block_marker = |source_info, block| {
-                branch_info.markers.inject_block_marker(&mut self.cfg, source_info, block)
-            };
-            mcdc_info.visit_evaluated_condition(
-                self.tcx,
-                source_info,
-                then_block,
-                else_block,
-                inject_block_marker,
-            );
-            return;
-        }
-
-        branch_info.add_two_way_branch(&mut self.cfg, source_info, then_block, else_block);
+        branch_info.register_two_way_branch(
+            self.tcx,
+            &mut self.cfg,
+            source_info,
+            then_block,
+            else_block,
+        );
     }
 
     /// If branch coverage is enabled, inject marker statements into `true_block`
@@ -270,6 +286,12 @@ impl<'tcx> Builder<'_, 'tcx> {
         // FIXME(#124144) This may need special handling when MC/DC is enabled.
 
         let source_info = SourceInfo { span: pattern.span, scope: self.source_scope };
-        branch_info.add_two_way_branch(&mut self.cfg, source_info, true_block, false_block);
+        branch_info.register_two_way_branch(
+            self.tcx,
+            &mut self.cfg,
+            source_info,
+            true_block,
+            false_block,
+        );
     }
 }

Diff for: compiler/rustc_mir_build/src/build/expr/into.rs

@@ -150,6 +150,9 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
             ExprKind::LogicalOp { op, lhs, rhs } => {
                 let condition_scope = this.local_scope();
                 let source_info = this.source_info(expr.span);
+
+                this.visit_coverage_branch_operation(op, expr.span);
+
                 // We first evaluate the left-hand side of the predicate ...
                 let (then_block, else_block) =
                     this.in_if_then_scope(condition_scope, expr.span, |this| {

Diff for: compiler/rustc_session/src/config.rs

@@ -1311,6 +1311,20 @@ pub fn build_target_config(early_dcx: &EarlyDiagCtxt, opts: &Options, sysroot: &
             for warning in warnings.warning_messages() {
                 early_dcx.early_warn(warning)
             }
+
+            // The `wasm32-wasi` target is being renamed to `wasm32-wasip1` as
+            // part of rust-lang/compiler-team#607 and
+            // rust-lang/compiler-team#695. Warn unconditionally on usage to
+            // raise awareness of the renaming. This code will be deleted in
+            // October 2024.
+            if opts.target_triple.triple() == "wasm32-wasi" {
+                early_dcx.early_warn(
+                    "the `wasm32-wasi` target is being renamed to \
+                    `wasm32-wasip1` and the `wasm32-wasi` target will be \
+                    removed from nightly in October 2024 and removed from \
+                    stable Rust in January 2025",
+                )
+            }
             if !matches!(target.pointer_width, 16 | 32 | 64) {
                 early_dcx.early_fatal(format!(
                     "target specification was invalid: unrecognized target-pointer-width {}",

Diff for: config.example.toml

@@ -321,8 +321,7 @@
 #
 # If `extended = false`, the only one of these built by default is rustdoc.
 #
-# If `extended = true`, they're all included, with the exception of
-# rust-demangler which additionally requires `profiler = true` to be set.
+# If `extended = true`, they are all included.
 #
 # If any enabled tool fails to build, the installation fails.
 #tools = [
@@ -334,7 +333,6 @@
 #    "rust-analyzer-proc-macro-srv",
 #    "analysis",
 #    "src",
-#    "rust-demangler",  # if profiler = true
 #]
 
 # Verbosity level: 0 == not verbose, 1 == verbose, 2 == very verbose, 3 == print environment variables on each rustc invocation

Diff for: src/bootstrap/src/core/build_steps/clippy.rs

@@ -322,7 +322,6 @@ lint_any!(
     RemoteTestServer, "src/tools/remote-test-server", "remote-test-server";
     Rls, "src/tools/rls", "rls";
     RustAnalyzer, "src/tools/rust-analyzer", "rust-analyzer";
-    RustDemangler, "src/tools/rust-demangler", "rust-demangler";
     Rustdoc, "src/tools/rustdoc", "clippy";
     Rustfmt, "src/tools/rustfmt", "rustfmt";
     RustInstaller, "src/tools/rust-installer", "rust-installer";