Rollup of 6 pull requests

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"

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",

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

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(())

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))
             }
         })
     }

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.

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,
+        );
     }
 }

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| {

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 {}",

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

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";

src/bootstrap/src/core/build_steps/dist.rs

@@ -1459,62 +1459,6 @@ impl Step for Rustfmt {
     }
 }
 
-#[derive(Debug, PartialOrd, Ord, Clone, Hash, PartialEq, Eq)]
-pub struct RustDemangler {
-    pub compiler: Compiler,
-    pub target: TargetSelection,
-}
-
-impl Step for RustDemangler {
-    type Output = Option<GeneratedTarball>;
-    const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
-
-    fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
-        // While other tools use `should_build_extended_tool` to decide whether to be run by
-        // default or not, `rust-demangler` must be build when *either* it's enabled as a tool like
-        // the other ones or if `profiler = true`. Because we don't know the target at this stage
-        // we run the step by default when only `extended = true`, and decide whether to actually
-        // run it or not later.
-        let default = run.builder.config.extended;
-        run.alias("rust-demangler").default_condition(default)
-    }
-
-    fn make_run(run: RunConfig<'_>) {
-        run.builder.ensure(RustDemangler {
-            compiler: run.builder.compiler_for(
-                run.builder.top_stage,
-                run.builder.config.build,
-                run.target,
-            ),
-            target: run.target,
-        });
-    }
-
-    fn run(self, builder: &Builder<'_>) -> Option<GeneratedTarball> {
-        let compiler = self.compiler;
-        let target = self.target;
-
-        // Only build this extended tool if explicitly included in `tools`, or if `profiler = true`
-        let condition = should_build_extended_tool(builder, "rust-demangler")
-            || builder.config.profiler_enabled(target);
-        if builder.config.extended && !condition {
-            return None;
-        }
-
-        let rust_demangler =
-            builder.ensure(tool::RustDemangler { compiler, target, extra_features: Vec::new() });
-
-        // Prepare the image directory
-        let mut tarball = Tarball::new(builder, "rust-demangler", &target.triple);
-        tarball.set_overlay(OverlayKind::RustDemangler);
-        tarball.is_preview(true);
-        tarball.add_file(rust_demangler, "bin", 0o755);
-        tarball.add_legal_and_readme_to("share/doc/rust-demangler");
-        Some(tarball.generate())
-    }
-}
-
 #[derive(Debug, PartialOrd, Ord, Clone, Hash, PartialEq, Eq)]
 pub struct Extended {
     stage: u32,
@@ -1572,7 +1516,6 @@ impl Step for Extended {
 
         add_component!("rust-docs" => Docs { host: target });
         add_component!("rust-json-docs" => JsonDocs { host: target });
-        add_component!("rust-demangler"=> RustDemangler { compiler, target });
         add_component!("cargo" => Cargo { compiler, target });
         add_component!("rustfmt" => Rustfmt { compiler, target });
         add_component!("rls" => Rls { compiler, target });
@@ -1636,7 +1579,7 @@ impl Step for Extended {
 
         let xform = |p: &Path| {
             let mut contents = t!(fs::read_to_string(p));
-            for tool in &["rust-demangler", "miri", "rust-docs"] {
+            for tool in &["miri", "rust-docs"] {
                 if !built_tools.contains(tool) {
                     contents = filter(&contents, tool);
                 }
@@ -1677,7 +1620,7 @@ impl Step for Extended {
             prepare("rust-analysis");
             prepare("clippy");
             prepare("rust-analyzer");
-            for tool in &["rust-docs", "rust-demangler", "miri", "rustc-codegen-cranelift"] {
+            for tool in &["rust-docs", "miri", "rustc-codegen-cranelift"] {
                 if built_tools.contains(tool) {
                     prepare(tool);
                 }
@@ -1717,8 +1660,6 @@ impl Step for Extended {
                     "rust-analyzer-preview".to_string()
                 } else if name == "clippy" {
                     "clippy-preview".to_string()
-                } else if name == "rust-demangler" {
-                    "rust-demangler-preview".to_string()
                 } else if name == "miri" {
                     "miri-preview".to_string()
                 } else if name == "rustc-codegen-cranelift" {
@@ -1738,7 +1679,7 @@ impl Step for Extended {
             prepare("cargo");
             prepare("rust-analysis");
             prepare("rust-std");
-            for tool in &["clippy", "rust-analyzer", "rust-docs", "rust-demangler", "miri"] {
+            for tool in &["clippy", "rust-analyzer", "rust-docs", "miri"] {
                 if built_tools.contains(tool) {
                     prepare(tool);
                 }
@@ -1862,25 +1803,6 @@ impl Step for Extended {
                         .arg(etc.join("msi/remove-duplicates.xsl")),
                 );
             }
-            if built_tools.contains("rust-demangler") {
-                builder.run(
-                    Command::new(&heat)
-                        .current_dir(&exe)
-                        .arg("dir")
-                        .arg("rust-demangler")
-                        .args(heat_flags)
-                        .arg("-cg")
-                        .arg("RustDemanglerGroup")
-                        .arg("-dr")
-                        .arg("RustDemangler")
-                        .arg("-var")
-                        .arg("var.RustDemanglerDir")
-                        .arg("-out")
-                        .arg(exe.join("RustDemanglerGroup.wxs"))
-                        .arg("-t")
-                        .arg(etc.join("msi/remove-duplicates.xsl")),
-                );
-            }
             if built_tools.contains("miri") {
                 builder.run(
                     Command::new(&heat)
@@ -1958,9 +1880,6 @@ impl Step for Extended {
                 if built_tools.contains("rust-docs") {
                     cmd.arg("-dDocsDir=rust-docs");
                 }
-                if built_tools.contains("rust-demangler") {
-                    cmd.arg("-dRustDemanglerDir=rust-demangler");
-                }
                 if built_tools.contains("rust-analyzer") {
                     cmd.arg("-dRustAnalyzerDir=rust-analyzer");
                 }
@@ -1987,9 +1906,6 @@ impl Step for Extended {
             if built_tools.contains("miri") {
                 candle("MiriGroup.wxs".as_ref());
             }
-            if built_tools.contains("rust-demangler") {
-                candle("RustDemanglerGroup.wxs".as_ref());
-            }
             if built_tools.contains("rust-analyzer") {
                 candle("RustAnalyzerGroup.wxs".as_ref());
             }
@@ -2031,9 +1947,6 @@ impl Step for Extended {
             if built_tools.contains("rust-analyzer") {
                 cmd.arg("RustAnalyzerGroup.wixobj");
             }
-            if built_tools.contains("rust-demangler") {
-                cmd.arg("RustDemanglerGroup.wixobj");
-            }
             if built_tools.contains("rust-docs") {
                 cmd.arg("DocsGroup.wixobj");
             }

src/bootstrap/src/core/build_steps/install.rs

@@ -265,22 +265,6 @@ install!((self, builder, _config),
             );
         }
     };
-    RustDemangler, alias = "rust-demangler", Self::should_build(_config), only_hosts: true, {
-        // NOTE: Even though `should_build` may return true for `extended` default tools,
-        // dist::RustDemangler may still return None, unless the target-dependent `profiler` config
-        // is also true, or the `tools` array explicitly includes "rust-demangler".
-        if let Some(tarball) = builder.ensure(dist::RustDemangler {
-            compiler: self.compiler,
-            target: self.target
-        }) {
-            install_sh(builder, "rust-demangler", self.compiler.stage, Some(self.target), &tarball);
-        } else {
-            builder.info(
-                &format!("skipping Install RustDemangler stage{} ({})",
-                         self.compiler.stage, self.target),
-            );
-        }
-    };
     Rustc, path = "compiler/rustc", true, only_hosts: true, {
         let tarball = builder.ensure(dist::Rustc {
             compiler: builder.compiler(builder.top_stage, self.target),

src/bootstrap/src/core/build_steps/test.rs

@@ -432,65 +432,6 @@ impl Step for Rustfmt {
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub struct RustDemangler {
-    stage: u32,
-    host: TargetSelection,
-}
-
-impl Step for RustDemangler {
-    type Output = ();
-    const ONLY_HOSTS: bool = true;
-
-    fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
-        run.path("src/tools/rust-demangler")
-    }
-
-    fn make_run(run: RunConfig<'_>) {
-        run.builder.ensure(RustDemangler { stage: run.builder.top_stage, host: run.target });
-    }
-
-    /// Runs `cargo test` for rust-demangler.
-    fn run(self, builder: &Builder<'_>) {
-        let stage = self.stage;
-        let host = self.host;
-        let compiler = builder.compiler(stage, host);
-
-        let rust_demangler = builder.ensure(tool::RustDemangler {
-            compiler,
-            target: self.host,
-            extra_features: Vec::new(),
-        });
-        let mut cargo = tool::prepare_tool_cargo(
-            builder,
-            compiler,
-            Mode::ToolRustc,
-            host,
-            "test",
-            "src/tools/rust-demangler",
-            SourceType::InTree,
-            &[],
-        );
-
-        let dir = testdir(builder, compiler.host);
-        t!(fs::create_dir_all(dir));
-
-        cargo.env("RUST_DEMANGLER_DRIVER_PATH", rust_demangler);
-        cargo.add_rustc_lib_path(builder);
-
-        run_cargo_test(
-            cargo,
-            &[],
-            &[],
-            "rust-demangler",
-            "rust-demangler",
-            compiler,
-            host,
-            builder,
-        );
-    }
-}
-
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct Miri {
     target: TargetSelection,

src/bootstrap/src/core/build_steps/tool.rs

@@ -964,7 +964,6 @@ tool_extended!((self, builder),
     // But `builder.cargo` doesn't know how to handle ToolBootstrap in stages other than 0,
     // and this is close enough for now.
     Rls, "src/tools/rls", "rls", stable=true, tool_std=true;
-    RustDemangler, "src/tools/rust-demangler", "rust-demangler", stable=false, tool_std=true;
     Rustfmt, "src/tools/rustfmt", "rustfmt", stable=true, add_bins_to_sysroot = ["rustfmt", "cargo-fmt"];
 );
 

src/bootstrap/src/core/builder.rs

@@ -736,7 +736,6 @@ impl<'a> Builder<'a> {
                 tool::Rls,
                 tool::RustAnalyzer,
                 tool::RustAnalyzerProcMacroSrv,
-                tool::RustDemangler,
                 tool::Rustdoc,
                 tool::Clippy,
                 tool::CargoClippy,
@@ -774,7 +773,6 @@ impl<'a> Builder<'a> {
                 clippy::RemoteTestServer,
                 clippy::Rls,
                 clippy::RustAnalyzer,
-                clippy::RustDemangler,
                 clippy::Rustdoc,
                 clippy::Rustfmt,
                 clippy::RustInstaller,
@@ -842,7 +840,6 @@ impl<'a> Builder<'a> {
                 test::Miri,
                 test::CargoMiri,
                 test::Clippy,
-                test::RustDemangler,
                 test::CompiletestTest,
                 test::CrateRunMakeSupport,
                 test::RustdocJSStd,
@@ -903,7 +900,6 @@ impl<'a> Builder<'a> {
                 dist::Rls,
                 dist::RustAnalyzer,
                 dist::Rustfmt,
-                dist::RustDemangler,
                 dist::Clippy,
                 dist::Miri,
                 dist::LlvmTools,
@@ -930,7 +926,6 @@ impl<'a> Builder<'a> {
                 install::Cargo,
                 install::RustAnalyzer,
                 install::Rustfmt,
-                install::RustDemangler,
                 install::Clippy,
                 install::Miri,
                 install::LlvmTools,
@@ -1036,23 +1031,12 @@ impl<'a> Builder<'a> {
     }
 
     pub fn doc_rust_lang_org_channel(&self) -> String {
-        // When using precompiled compiler from CI, we need to use CI rustc's channel and
-        // ignore `rust.channel` from the configuration. Otherwise most of the rustdoc tests
-        // will fail due to incompatible `DOC_RUST_LANG_ORG_CHANNEL`.
-        let channel = if let Some(commit) = self.config.download_rustc_commit() {
-            self.config
-                .read_file_by_commit(&PathBuf::from("src/ci/channel"), commit)
-                .trim()
-                .to_owned()
-        } else {
-            match &*self.config.channel {
-                "stable" => &self.version,
-                "beta" => "beta",
-                "nightly" | "dev" => "nightly",
-                // custom build of rustdoc maybe? link to the latest stable docs just in case
-                _ => "stable",
-            }
-            .to_owned()
+        let channel = match &*self.config.channel {
+            "stable" => &self.version,
+            "beta" => "beta",
+            "nightly" | "dev" => "nightly",
+            // custom build of rustdoc maybe? link to the latest stable docs just in case
+            _ => "stable",
         };
 
         format!("https://doc.rust-lang.org/{channel}")

src/bootstrap/src/core/config/config.rs

@@ -1718,7 +1718,23 @@ impl Config {
         config.omit_git_hash = omit_git_hash.unwrap_or(default);
         config.rust_info = GitInfo::new(config.omit_git_hash, &config.src);
 
-        if config.rust_info.is_from_tarball() && !is_user_configured_rust_channel {
+        // We need to override `rust.channel` if it's manually specified when using the CI rustc.
+        // This is because if the compiler uses a different channel than the one specified in config.toml,
+        // tests may fail due to using a different channel than the one used by the compiler during tests.
+        if let Some(commit) = &config.download_rustc_commit {
+            if is_user_configured_rust_channel {
+                println!(
+                    "WARNING: `rust.download-rustc` is enabled. The `rust.channel` option will be overridden by the CI rustc's channel."
+                );
+
+                let channel = config
+                    .read_file_by_commit(&PathBuf::from("src/ci/channel"), commit)
+                    .trim()
+                    .to_owned();
+
+                config.channel = channel;
+            }
+        } else if config.rust_info.is_from_tarball() && !is_user_configured_rust_channel {
             ci_channel.clone_into(&mut config.channel);
         }
 

src/bootstrap/src/utils/tarball.rs

@@ -23,7 +23,6 @@ pub(crate) enum OverlayKind {
     Clippy,
     Miri,
     Rustfmt,
-    RustDemangler,
     Rls,
     RustAnalyzer,
     RustcCodegenCranelift,
@@ -58,9 +57,6 @@ impl OverlayKind {
                 "src/tools/rustfmt/LICENSE-APACHE",
                 "src/tools/rustfmt/LICENSE-MIT",
             ],
-            OverlayKind::RustDemangler => {
-                &["src/tools/rust-demangler/README.md", "LICENSE-APACHE", "LICENSE-MIT"]
-            }
             OverlayKind::Rls => &["src/tools/rls/README.md", "LICENSE-APACHE", "LICENSE-MIT"],
             OverlayKind::RustAnalyzer => &[
                 "src/tools/rust-analyzer/README.md",
@@ -85,7 +81,6 @@ impl OverlayKind {
         match self {
             OverlayKind::Rust => builder.rust_version(),
             OverlayKind::Llvm => builder.rust_version(),
-            OverlayKind::RustDemangler => builder.release_num("rust-demangler"),
             OverlayKind::Cargo => {
                 builder.cargo_info.version(builder, &builder.release_num("cargo"))
             }

src/doc/rustc/src/instrument-coverage.md

@@ -49,12 +49,6 @@ One option for a Rust demangler is [`rustfilt`], which can be installed with:
 cargo install rustfilt
 ```
 
-Another option, if you are building from the Rust compiler source distribution, is to use the `rust-demangler` tool included in the Rust source distribution, which can be built with:
-
-```shell
-$ ./x.py build rust-demangler
-```
-
 [`rustfilt`]: https://crates.io/crates/rustfilt
 
 ## Compiling with coverage enabled
@@ -164,7 +158,7 @@ $ llvm-cov show -Xdemangler=rustfilt target/debug/examples/formatjson5 \
 
 Some of the more notable options in this example include:
 
--   `--Xdemangler=rustfilt` - the command name or path used to demangle Rust symbols (`rustfilt` in the example, but this could also be a path to the `rust-demangler` tool)
+-   `--Xdemangler=rustfilt` - the command name or path used to demangle Rust symbols (`rustfilt` in the example)
 -   `target/debug/examples/formatjson5` - the instrumented binary (from which to extract the coverage map)
 -   `--instr-profile=<path-to-file>.profdata` - the location of the `.profdata` file created by `llvm-profdata merge` (from the `.profraw` file generated by the instrumented binary)
 -   `--name=<exact-function-name>` - to show coverage for a specific function (or, consider using another filter option, such as `--name-regex=<pattern>`)

src/tools/miri/tests/fail/storage-live-dead-var.rs

@@ -0,0 +1,14 @@
+#![feature(core_intrinsics, custom_mir)]
+use std::intrinsics::mir::*;
+
+#[custom_mir(dialect = "runtime")]
+fn main() {
+    mir! {
+        let val: i32;
+        {
+            val = 42; //~ERROR: accessing a dead local variable
+            StorageLive(val); // too late... (but needs to be here to make `val` not implicitly live)
+            Return()
+        }
+    }
+}

src/tools/miri/tests/fail/storage-live-dead-var.stderr

@@ -0,0 +1,15 @@
+error: Undefined Behavior: accessing a dead local variable
+  --> $DIR/storage-live-dead-var.rs:LL:CC
+   |
+LL |             val = 42;
+   |             ^^^^^^^^ accessing a dead local variable
+   |
+   = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
+   = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information
+   = note: BACKTRACE:
+   = note: inside `main` at $DIR/storage-live-dead-var.rs:LL:CC
+
+note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
+
+error: aborting due to 1 previous error
+

src/tools/miri/tests/fail/storage-live-resets-var.rs

@@ -0,0 +1,17 @@
+#![feature(core_intrinsics, custom_mir)]
+use std::intrinsics::mir::*;
+
+#[custom_mir(dialect = "runtime")]
+fn main() {
+    mir! {
+        let val: i32;
+        let _val2: i32;
+        {
+            StorageLive(val);
+            val = 42;
+            StorageLive(val); // reset val to `uninit`
+            _val2 = val; //~ERROR: uninitialized
+            Return()
+        }
+    }
+}

src/tools/miri/tests/fail/storage-live-resets-var.stderr

@@ -0,0 +1,15 @@
+error: Undefined Behavior: constructing invalid value: encountered uninitialized memory, but expected an integer
+  --> $DIR/storage-live-resets-var.rs:LL:CC
+   |
+LL |             _val2 = val;
+   |             ^^^^^^^^^^^ constructing invalid value: encountered uninitialized memory, but expected an integer
+   |
+   = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
+   = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information
+   = note: BACKTRACE:
+   = note: inside `main` at $DIR/storage-live-resets-var.rs:LL:CC
+
+note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
+
+error: aborting due to 1 previous error
+

tests/coverage/mcdc_non_control_flow.cov-map

@@ -0,0 +1,204 @@
+Function name: mcdc_non_control_flow::assign_3
+Raw bytes (89): 0x[01, 01, 09, 05, 07, 0b, 11, 09, 0d, 01, 05, 01, 05, 22, 11, 01, 05, 22, 11, 01, 05, 0a, 01, 16, 01, 00, 28, 03, 01, 09, 00, 0a, 01, 00, 0d, 00, 0e, 28, 00, 03, 00, 0d, 00, 18, 30, 05, 22, 01, 00, 02, 00, 0d, 00, 0e, 22, 00, 12, 00, 13, 30, 1e, 11, 02, 03, 00, 00, 12, 00, 13, 1e, 00, 17, 00, 18, 30, 09, 0d, 03, 00, 00, 00, 17, 00, 18, 03, 01, 05, 01, 02]
+Number of files: 1
+- file 0 => global file 1
+Number of expressions: 9
+- expression 0 operands: lhs = Counter(1), rhs = Expression(1, Add)
+- expression 1 operands: lhs = Expression(2, Add), rhs = Counter(4)
+- expression 2 operands: lhs = Counter(2), rhs = Counter(3)
+- expression 3 operands: lhs = Counter(0), rhs = Counter(1)
+- expression 4 operands: lhs = Counter(0), rhs = Counter(1)
+- expression 5 operands: lhs = Expression(8, Sub), rhs = Counter(4)
+- expression 6 operands: lhs = Counter(0), rhs = Counter(1)
+- expression 7 operands: lhs = Expression(8, Sub), rhs = Counter(4)
+- expression 8 operands: lhs = Counter(0), rhs = Counter(1)
+Number of file 0 mappings: 10
+- Code(Counter(0)) at (prev + 22, 1) to (start + 0, 40)
+- Code(Expression(0, Add)) at (prev + 1, 9) to (start + 0, 10)
+    = (c1 + ((c2 + c3) + c4))
+- Code(Counter(0)) at (prev + 0, 13) to (start + 0, 14)
+- MCDCDecision { bitmap_idx: 0, conditions_num: 3 } at (prev + 0, 13) to (start + 0, 24)
+- MCDCBranch { true: Counter(1), false: Expression(8, Sub), condition_id: 1, true_next_id: 0, false_next_id: 2 } at (prev + 0, 13) to (start + 0, 14)
+    true  = c1
+    false = (c0 - c1)
+- Code(Expression(8, Sub)) at (prev + 0, 18) to (start + 0, 19)
+    = (c0 - c1)
+- MCDCBranch { true: Expression(7, Sub), false: Counter(4), condition_id: 2, true_next_id: 3, false_next_id: 0 } at (prev + 0, 18) to (start + 0, 19)
+    true  = ((c0 - c1) - c4)
+    false = c4
+- Code(Expression(7, Sub)) at (prev + 0, 23) to (start + 0, 24)
+    = ((c0 - c1) - c4)
+- MCDCBranch { true: Counter(2), false: Counter(3), condition_id: 3, true_next_id: 0, false_next_id: 0 } at (prev + 0, 23) to (start + 0, 24)
+    true  = c2
+    false = c3
+- Code(Expression(0, Add)) at (prev + 1, 5) to (start + 1, 2)
+    = (c1 + ((c2 + c3) + c4))
+
+Function name: mcdc_non_control_flow::assign_3_bis
+Raw bytes (85): 0x[01, 01, 07, 07, 11, 09, 0d, 01, 05, 05, 09, 16, 1a, 05, 09, 01, 05, 0a, 01, 1b, 01, 00, 2c, 03, 01, 09, 00, 0a, 01, 00, 0d, 00, 0e, 28, 00, 03, 00, 0d, 00, 18, 30, 05, 1a, 01, 03, 02, 00, 0d, 00, 0e, 05, 00, 12, 00, 13, 30, 09, 16, 03, 00, 02, 00, 12, 00, 13, 13, 00, 17, 00, 18, 30, 0d, 11, 02, 00, 00, 00, 17, 00, 18, 03, 01, 05, 01, 02]
+Number of files: 1
+- file 0 => global file 1
+Number of expressions: 7
+- expression 0 operands: lhs = Expression(1, Add), rhs = Counter(4)
+- expression 1 operands: lhs = Counter(2), rhs = Counter(3)
+- expression 2 operands: lhs = Counter(0), rhs = Counter(1)
+- expression 3 operands: lhs = Counter(1), rhs = Counter(2)
+- expression 4 operands: lhs = Expression(5, Sub), rhs = Expression(6, Sub)
+- expression 5 operands: lhs = Counter(1), rhs = Counter(2)
+- expression 6 operands: lhs = Counter(0), rhs = Counter(1)
+Number of file 0 mappings: 10
+- Code(Counter(0)) at (prev + 27, 1) to (start + 0, 44)
+- Code(Expression(0, Add)) at (prev + 1, 9) to (start + 0, 10)
+    = ((c2 + c3) + c4)
+- Code(Counter(0)) at (prev + 0, 13) to (start + 0, 14)
+- MCDCDecision { bitmap_idx: 0, conditions_num: 3 } at (prev + 0, 13) to (start + 0, 24)
+- MCDCBranch { true: Counter(1), false: Expression(6, Sub), condition_id: 1, true_next_id: 3, false_next_id: 2 } at (prev + 0, 13) to (start + 0, 14)
+    true  = c1
+    false = (c0 - c1)
+- Code(Counter(1)) at (prev + 0, 18) to (start + 0, 19)
+- MCDCBranch { true: Counter(2), false: Expression(5, Sub), condition_id: 3, true_next_id: 0, false_next_id: 2 } at (prev + 0, 18) to (start + 0, 19)
+    true  = c2
+    false = (c1 - c2)
+- Code(Expression(4, Add)) at (prev + 0, 23) to (start + 0, 24)
+    = ((c1 - c2) + (c0 - c1))
+- MCDCBranch { true: Counter(3), false: Counter(4), condition_id: 2, true_next_id: 0, false_next_id: 0 } at (prev + 0, 23) to (start + 0, 24)
+    true  = c3
+    false = c4
+- Code(Expression(0, Add)) at (prev + 1, 5) to (start + 1, 2)
+    = ((c2 + c3) + c4)
+
+Function name: mcdc_non_control_flow::assign_and
+Raw bytes (64): 0x[01, 01, 04, 07, 0e, 09, 0d, 01, 05, 01, 05, 08, 01, 0c, 01, 00, 21, 03, 01, 09, 00, 0a, 01, 00, 0d, 00, 0e, 28, 00, 02, 00, 0d, 00, 13, 30, 05, 0e, 01, 02, 00, 00, 0d, 00, 0e, 05, 00, 12, 00, 13, 30, 09, 0d, 02, 00, 00, 00, 12, 00, 13, 03, 01, 05, 01, 02]
+Number of files: 1
+- file 0 => global file 1
+Number of expressions: 4
+- expression 0 operands: lhs = Expression(1, Add), rhs = Expression(3, Sub)
+- expression 1 operands: lhs = Counter(2), rhs = Counter(3)
+- expression 2 operands: lhs = Counter(0), rhs = Counter(1)
+- expression 3 operands: lhs = Counter(0), rhs = Counter(1)
+Number of file 0 mappings: 8
+- Code(Counter(0)) at (prev + 12, 1) to (start + 0, 33)
+- Code(Expression(0, Add)) at (prev + 1, 9) to (start + 0, 10)
+    = ((c2 + c3) + (c0 - c1))
+- Code(Counter(0)) at (prev + 0, 13) to (start + 0, 14)
+- MCDCDecision { bitmap_idx: 0, conditions_num: 2 } at (prev + 0, 13) to (start + 0, 19)
+- MCDCBranch { true: Counter(1), false: Expression(3, Sub), condition_id: 1, true_next_id: 2, false_next_id: 0 } at (prev + 0, 13) to (start + 0, 14)
+    true  = c1
+    false = (c0 - c1)
+- Code(Counter(1)) at (prev + 0, 18) to (start + 0, 19)
+- MCDCBranch { true: Counter(2), false: Counter(3), condition_id: 2, true_next_id: 0, false_next_id: 0 } at (prev + 0, 18) to (start + 0, 19)
+    true  = c2
+    false = c3
+- Code(Expression(0, Add)) at (prev + 1, 5) to (start + 1, 2)
+    = ((c2 + c3) + (c0 - c1))
+
+Function name: mcdc_non_control_flow::assign_or
+Raw bytes (64): 0x[01, 01, 04, 07, 0d, 05, 09, 01, 05, 01, 05, 08, 01, 11, 01, 00, 20, 03, 01, 09, 00, 0a, 01, 00, 0d, 00, 0e, 28, 00, 02, 00, 0d, 00, 13, 30, 05, 0e, 01, 00, 02, 00, 0d, 00, 0e, 0e, 00, 12, 00, 13, 30, 09, 0d, 02, 00, 00, 00, 12, 00, 13, 03, 01, 05, 01, 02]
+Number of files: 1
+- file 0 => global file 1
+Number of expressions: 4
+- expression 0 operands: lhs = Expression(1, Add), rhs = Counter(3)
+- expression 1 operands: lhs = Counter(1), rhs = Counter(2)
+- expression 2 operands: lhs = Counter(0), rhs = Counter(1)
+- expression 3 operands: lhs = Counter(0), rhs = Counter(1)
+Number of file 0 mappings: 8
+- Code(Counter(0)) at (prev + 17, 1) to (start + 0, 32)
+- Code(Expression(0, Add)) at (prev + 1, 9) to (start + 0, 10)
+    = ((c1 + c2) + c3)
+- Code(Counter(0)) at (prev + 0, 13) to (start + 0, 14)
+- MCDCDecision { bitmap_idx: 0, conditions_num: 2 } at (prev + 0, 13) to (start + 0, 19)
+- MCDCBranch { true: Counter(1), false: Expression(3, Sub), condition_id: 1, true_next_id: 0, false_next_id: 2 } at (prev + 0, 13) to (start + 0, 14)
+    true  = c1
+    false = (c0 - c1)
+- Code(Expression(3, Sub)) at (prev + 0, 18) to (start + 0, 19)
+    = (c0 - c1)
+- MCDCBranch { true: Counter(2), false: Counter(3), condition_id: 2, true_next_id: 0, false_next_id: 0 } at (prev + 0, 18) to (start + 0, 19)
+    true  = c2
+    false = c3
+- Code(Expression(0, Add)) at (prev + 1, 5) to (start + 1, 2)
+    = ((c1 + c2) + c3)
+
+Function name: mcdc_non_control_flow::foo
+Raw bytes (9): 0x[01, 01, 00, 01, 01, 25, 01, 02, 02]
+Number of files: 1
+- file 0 => global file 1
+Number of expressions: 0
+Number of file 0 mappings: 1
+- Code(Counter(0)) at (prev + 37, 1) to (start + 2, 2)
+
+Function name: mcdc_non_control_flow::func_call
+Raw bytes (52): 0x[01, 01, 03, 01, 05, 0b, 02, 09, 0d, 06, 01, 29, 01, 01, 0a, 28, 00, 02, 01, 09, 00, 0f, 30, 05, 02, 01, 02, 00, 00, 09, 00, 0a, 05, 00, 0e, 00, 0f, 30, 09, 0d, 02, 00, 00, 00, 0e, 00, 0f, 07, 01, 01, 00, 02]
+Number of files: 1
+- file 0 => global file 1
+Number of expressions: 3
+- expression 0 operands: lhs = Counter(0), rhs = Counter(1)
+- expression 1 operands: lhs = Expression(2, Add), rhs = Expression(0, Sub)
+- expression 2 operands: lhs = Counter(2), rhs = Counter(3)
+Number of file 0 mappings: 6
+- Code(Counter(0)) at (prev + 41, 1) to (start + 1, 10)
+- MCDCDecision { bitmap_idx: 0, conditions_num: 2 } at (prev + 1, 9) to (start + 0, 15)
+- MCDCBranch { true: Counter(1), false: Expression(0, Sub), condition_id: 1, true_next_id: 2, false_next_id: 0 } at (prev + 0, 9) to (start + 0, 10)
+    true  = c1
+    false = (c0 - c1)
+- Code(Counter(1)) at (prev + 0, 14) to (start + 0, 15)
+- MCDCBranch { true: Counter(2), false: Counter(3), condition_id: 2, true_next_id: 0, false_next_id: 0 } at (prev + 0, 14) to (start + 0, 15)
+    true  = c2
+    false = c3
+- Code(Expression(1, Add)) at (prev + 1, 1) to (start + 0, 2)
+    = ((c2 + c3) + (c0 - c1))
+
+Function name: mcdc_non_control_flow::right_comb_tree
+Raw bytes (139): 0x[01, 01, 13, 07, 1a, 0b, 19, 0f, 15, 13, 11, 09, 0d, 01, 05, 01, 05, 05, 19, 05, 19, 4a, 15, 05, 19, 4a, 15, 05, 19, 46, 11, 4a, 15, 05, 19, 46, 11, 4a, 15, 05, 19, 0e, 01, 20, 01, 00, 41, 03, 01, 09, 00, 0a, 01, 00, 0d, 00, 0e, 28, 00, 05, 00, 0d, 00, 2a, 30, 05, 1a, 01, 02, 00, 00, 0d, 00, 0e, 05, 00, 13, 00, 14, 30, 4a, 19, 02, 03, 00, 00, 13, 00, 14, 4a, 00, 19, 00, 1a, 30, 46, 15, 03, 04, 00, 00, 19, 00, 1a, 46, 00, 1f, 00, 20, 30, 42, 11, 04, 05, 00, 00, 1f, 00, 20, 42, 00, 24, 00, 27, 30, 09, 0d, 05, 00, 00, 00, 24, 00, 27, 03, 01, 05, 01, 02]
+Number of files: 1
+- file 0 => global file 1
+Number of expressions: 19
+- expression 0 operands: lhs = Expression(1, Add), rhs = Expression(6, Sub)
+- expression 1 operands: lhs = Expression(2, Add), rhs = Counter(6)
+- expression 2 operands: lhs = Expression(3, Add), rhs = Counter(5)
+- expression 3 operands: lhs = Expression(4, Add), rhs = Counter(4)
+- expression 4 operands: lhs = Counter(2), rhs = Counter(3)
+- expression 5 operands: lhs = Counter(0), rhs = Counter(1)
+- expression 6 operands: lhs = Counter(0), rhs = Counter(1)
+- expression 7 operands: lhs = Counter(1), rhs = Counter(6)
+- expression 8 operands: lhs = Counter(1), rhs = Counter(6)
+- expression 9 operands: lhs = Expression(18, Sub), rhs = Counter(5)
+- expression 10 operands: lhs = Counter(1), rhs = Counter(6)
+- expression 11 operands: lhs = Expression(18, Sub), rhs = Counter(5)
+- expression 12 operands: lhs = Counter(1), rhs = Counter(6)
+- expression 13 operands: lhs = Expression(17, Sub), rhs = Counter(4)
+- expression 14 operands: lhs = Expression(18, Sub), rhs = Counter(5)
+- expression 15 operands: lhs = Counter(1), rhs = Counter(6)
+- expression 16 operands: lhs = Expression(17, Sub), rhs = Counter(4)
+- expression 17 operands: lhs = Expression(18, Sub), rhs = Counter(5)
+- expression 18 operands: lhs = Counter(1), rhs = Counter(6)
+Number of file 0 mappings: 14
+- Code(Counter(0)) at (prev + 32, 1) to (start + 0, 65)
+- Code(Expression(0, Add)) at (prev + 1, 9) to (start + 0, 10)
+    = (((((c2 + c3) + c4) + c5) + c6) + (c0 - c1))
+- Code(Counter(0)) at (prev + 0, 13) to (start + 0, 14)
+- MCDCDecision { bitmap_idx: 0, conditions_num: 5 } at (prev + 0, 13) to (start + 0, 42)
+- MCDCBranch { true: Counter(1), false: Expression(6, Sub), condition_id: 1, true_next_id: 2, false_next_id: 0 } at (prev + 0, 13) to (start + 0, 14)
+    true  = c1
+    false = (c0 - c1)
+- Code(Counter(1)) at (prev + 0, 19) to (start + 0, 20)
+- MCDCBranch { true: Expression(18, Sub), false: Counter(6), condition_id: 2, true_next_id: 3, false_next_id: 0 } at (prev + 0, 19) to (start + 0, 20)
+    true  = (c1 - c6)
+    false = c6
+- Code(Expression(18, Sub)) at (prev + 0, 25) to (start + 0, 26)
+    = (c1 - c6)
+- MCDCBranch { true: Expression(17, Sub), false: Counter(5), condition_id: 3, true_next_id: 4, false_next_id: 0 } at (prev + 0, 25) to (start + 0, 26)
+    true  = ((c1 - c6) - c5)
+    false = c5
+- Code(Expression(17, Sub)) at (prev + 0, 31) to (start + 0, 32)
+    = ((c1 - c6) - c5)
+- MCDCBranch { true: Expression(16, Sub), false: Counter(4), condition_id: 4, true_next_id: 5, false_next_id: 0 } at (prev + 0, 31) to (start + 0, 32)
+    true  = (((c1 - c6) - c5) - c4)
+    false = c4
+- Code(Expression(16, Sub)) at (prev + 0, 36) to (start + 0, 39)
+    = (((c1 - c6) - c5) - c4)
+- MCDCBranch { true: Counter(2), false: Counter(3), condition_id: 5, true_next_id: 0, false_next_id: 0 } at (prev + 0, 36) to (start + 0, 39)
+    true  = c2
+    false = c3
+- Code(Expression(0, Add)) at (prev + 1, 5) to (start + 1, 2)
+    = (((((c2 + c3) + c4) + c5) + c6) + (c0 - c1))
+

tests/coverage/mcdc_non_control_flow.coverage

@@ -0,0 +1,202 @@
+   LL|       |#![feature(coverage_attribute)]
+   LL|       |//@ edition: 2021
+   LL|       |//@ min-llvm-version: 18
+   LL|       |//@ compile-flags: -Zcoverage-options=mcdc
+   LL|       |//@ llvm-cov-flags: --show-mcdc
+   LL|       |
+   LL|       |// This test ensures that boolean expressions that are not inside control flow
+   LL|       |// decisions are correctly instrumented.
+   LL|       |
+   LL|       |use core::hint::black_box;
+   LL|       |
+   LL|      3|fn assign_and(a: bool, b: bool) {
+   LL|      3|    let x = a && b;
+                               ^2
+  ------------------
+  |---> MC/DC Decision Region (LL:13) to (LL:19)
+  |
+  |  Number of Conditions: 2
+  |     Condition C1 --> (LL:13)
+  |     Condition C2 --> (LL:18)
+  |
+  |  Executed MC/DC Test Vectors:
+  |
+  |     C1, C2    Result
+  |  1 { F,  -  = F      }
+  |  2 { T,  F  = F      }
+  |  3 { T,  T  = T      }
+  |
+  |  C1-Pair: covered: (1,3)
+  |  C2-Pair: covered: (2,3)
+  |  MC/DC Coverage for Decision: 100.00%
+  |
+  ------------------
+   LL|      3|    black_box(x);
+   LL|      3|}
+   LL|       |
+   LL|      3|fn assign_or(a: bool, b: bool) {
+   LL|      3|    let x = a || b;
+                               ^1
+  ------------------
+  |---> MC/DC Decision Region (LL:13) to (LL:19)
+  |
+  |  Number of Conditions: 2
+  |     Condition C1 --> (LL:13)
+  |     Condition C2 --> (LL:18)
+  |
+  |  Executed MC/DC Test Vectors:
+  |
+  |     C1, C2    Result
+  |  1 { F,  F  = F      }
+  |  2 { T,  -  = T      }
+  |
+  |  C1-Pair: covered: (1,2)
+  |  C2-Pair: not covered
+  |  MC/DC Coverage for Decision: 50.00%
+  |
+  ------------------
+   LL|      3|    black_box(x);
+   LL|      3|}
+   LL|       |
+   LL|      4|fn assign_3(a: bool, b: bool, c: bool) {
+   LL|      4|    let x = a || b && c;
+                               ^2   ^1
+  ------------------
+  |---> MC/DC Decision Region (LL:13) to (LL:24)
+  |
+  |  Number of Conditions: 3
+  |     Condition C1 --> (LL:13)
+  |     Condition C2 --> (LL:18)
+  |     Condition C3 --> (LL:23)
+  |
+  |  Executed MC/DC Test Vectors:
+  |
+  |     C1, C2, C3    Result
+  |  1 { F,  F,  -  = F      }
+  |  2 { T,  -,  -  = T      }
+  |  3 { F,  T,  T  = T      }
+  |
+  |  C1-Pair: covered: (1,2)
+  |  C2-Pair: covered: (1,3)
+  |  C3-Pair: not covered
+  |  MC/DC Coverage for Decision: 66.67%
+  |
+  ------------------
+   LL|      4|    black_box(x);
+   LL|      4|}
+   LL|       |
+   LL|      4|fn assign_3_bis(a: bool, b: bool, c: bool) {
+   LL|      4|    let x = a && b || c;
+                               ^2   ^3
+  ------------------
+  |---> MC/DC Decision Region (LL:13) to (LL:24)
+  |
+  |  Number of Conditions: 3
+  |     Condition C1 --> (LL:13)
+  |     Condition C2 --> (LL:18)
+  |     Condition C3 --> (LL:23)
+  |
+  |  Executed MC/DC Test Vectors:
+  |
+  |     C1, C2, C3    Result
+  |  1 { T,  F,  F  = F      }
+  |  2 { F,  -,  T  = T      }
+  |  3 { T,  T,  -  = T      }
+  |
+  |  C1-Pair: not covered
+  |  C2-Pair: covered: (1,3)
+  |  C3-Pair: not covered
+  |  MC/DC Coverage for Decision: 33.33%
+  |
+  ------------------
+   LL|      4|    black_box(x);
+   LL|      4|}
+   LL|       |
+   LL|      3|fn right_comb_tree(a: bool, b: bool, c: bool, d: bool, e: bool) {
+   LL|      3|    let x = a && (b && (c && (d && (e))));
+                                ^2    ^1    ^1   ^1
+  ------------------
+  |---> MC/DC Decision Region (LL:13) to (LL:42)
+  |
+  |  Number of Conditions: 5
+  |     Condition C1 --> (LL:13)
+  |     Condition C2 --> (LL:19)
+  |     Condition C3 --> (LL:25)
+  |     Condition C4 --> (LL:31)
+  |     Condition C5 --> (LL:36)
+  |
+  |  Executed MC/DC Test Vectors:
+  |
+  |     C1, C2, C3, C4, C5    Result
+  |  1 { F,  -,  -,  -,  -  = F      }
+  |  2 { T,  F,  -,  -,  -  = F      }
+  |  3 { T,  T,  T,  T,  T  = T      }
+  |
+  |  C1-Pair: covered: (1,3)
+  |  C2-Pair: covered: (2,3)
+  |  C3-Pair: not covered
+  |  C4-Pair: not covered
+  |  C5-Pair: not covered
+  |  MC/DC Coverage for Decision: 40.00%
+  |
+  ------------------
+   LL|      3|    black_box(x);
+   LL|      3|}
+   LL|       |
+   LL|      3|fn foo(a: bool) -> bool {
+   LL|      3|    black_box(a)
+   LL|      3|}
+   LL|       |
+   LL|      3|fn func_call(a: bool, b: bool) {
+   LL|      3|    foo(a && b);
+                           ^2
+  ------------------
+  |---> MC/DC Decision Region (LL:9) to (LL:15)
+  |
+  |  Number of Conditions: 2
+  |     Condition C1 --> (LL:9)
+  |     Condition C2 --> (LL:14)
+  |
+  |  Executed MC/DC Test Vectors:
+  |
+  |     C1, C2    Result
+  |  1 { F,  -  = F      }
+  |  2 { T,  F  = F      }
+  |  3 { T,  T  = T      }
+  |
+  |  C1-Pair: covered: (1,3)
+  |  C2-Pair: covered: (2,3)
+  |  MC/DC Coverage for Decision: 100.00%
+  |
+  ------------------
+   LL|      3|}
+   LL|       |
+   LL|       |#[coverage(off)]
+   LL|       |fn main() {
+   LL|       |    assign_and(true, false);
+   LL|       |    assign_and(true, true);
+   LL|       |    assign_and(false, false);
+   LL|       |
+   LL|       |    assign_or(true, false);
+   LL|       |    assign_or(true, true);
+   LL|       |    assign_or(false, false);
+   LL|       |
+   LL|       |    assign_3(true, false, false);
+   LL|       |    assign_3(true, true, false);
+   LL|       |    assign_3(false, false, true);
+   LL|       |    assign_3(false, true, true);
+   LL|       |
+   LL|       |    assign_3_bis(true, false, false);
+   LL|       |    assign_3_bis(true, true, false);
+   LL|       |    assign_3_bis(false, false, true);
+   LL|       |    assign_3_bis(false, true, true);
+   LL|       |
+   LL|       |    right_comb_tree(false, false, false, true, true);
+   LL|       |    right_comb_tree(true, false, false, true, true);
+   LL|       |    right_comb_tree(true, true, true, true, true);
+   LL|       |
+   LL|       |    func_call(true, false);
+   LL|       |    func_call(true, true);
+   LL|       |    func_call(false, false);
+   LL|       |}
+

tests/coverage/mcdc_non_control_flow.rs

@@ -0,0 +1,72 @@
+#![feature(coverage_attribute)]
+//@ edition: 2021
+//@ min-llvm-version: 18
+//@ compile-flags: -Zcoverage-options=mcdc
+//@ llvm-cov-flags: --show-mcdc
+
+// This test ensures that boolean expressions that are not inside control flow
+// decisions are correctly instrumented.
+
+use core::hint::black_box;
+
+fn assign_and(a: bool, b: bool) {
+    let x = a && b;
+    black_box(x);
+}
+
+fn assign_or(a: bool, b: bool) {
+    let x = a || b;
+    black_box(x);
+}
+
+fn assign_3(a: bool, b: bool, c: bool) {
+    let x = a || b && c;
+    black_box(x);
+}
+
+fn assign_3_bis(a: bool, b: bool, c: bool) {
+    let x = a && b || c;
+    black_box(x);
+}
+
+fn right_comb_tree(a: bool, b: bool, c: bool, d: bool, e: bool) {
+    let x = a && (b && (c && (d && (e))));
+    black_box(x);
+}
+
+fn foo(a: bool) -> bool {
+    black_box(a)
+}
+
+fn func_call(a: bool, b: bool) {
+    foo(a && b);
+}
+
+#[coverage(off)]
+fn main() {
+    assign_and(true, false);
+    assign_and(true, true);
+    assign_and(false, false);
+
+    assign_or(true, false);
+    assign_or(true, true);
+    assign_or(false, false);
+
+    assign_3(true, false, false);
+    assign_3(true, true, false);
+    assign_3(false, false, true);
+    assign_3(false, true, true);
+
+    assign_3_bis(true, false, false);
+    assign_3_bis(true, true, false);
+    assign_3_bis(false, false, true);
+    assign_3_bis(false, true, true);
+
+    right_comb_tree(false, false, false, true, true);
+    right_comb_tree(true, false, false, true, true);
+    right_comb_tree(true, true, true, true, true);
+
+    func_call(true, false);
+    func_call(true, true);
+    func_call(false, false);
+}

tests/ui/impl-trait/lazy_subtyping_of_opaques.rs

@@ -2,58 +2,23 @@
 //! No hidden types are being constrained in the subtyping predicate, but type and
 //! lifetime variables get subtyped in the generic parameter list of the opaque.
 
-use std::iter;
-
-mod either {
-    pub enum Either<L, R> {
-        Left(L),
-        Right(R),
-    }
-
-    impl<L: Iterator, R: Iterator<Item = L::Item>> Iterator for Either<L, R> {
-        type Item = L::Item;
-        fn next(&mut self) -> Option<Self::Item> {
-            todo!()
-        }
-    }
-    pub use self::Either::{Left, Right};
-}
-
-pub enum BabeConsensusLogRef<'a> {
-    NextEpochData(BabeNextEpochRef<'a>),
-    NextConfigData,
-}
-
-impl<'a> BabeConsensusLogRef<'a> {
-    pub fn scale_encoding(
-        &self,
-    ) -> impl Iterator<Item = impl AsRef<[u8]> + Clone + 'a> + Clone + 'a {
-        //~^ ERROR is not satisfied
-        //~| ERROR is not satisfied
-        //~| ERROR is not satisfied
-        match self {
-            BabeConsensusLogRef::NextEpochData(digest) => either::Left(either::Left(
-                digest.scale_encoding().map(either::Left).map(either::Left),
-            )),
-            BabeConsensusLogRef::NextConfigData => either::Right(
-                // The Opaque type from ``scale_encoding` gets used opaquely here, while the `R`
-                // generic parameter of `Either` contains type variables that get subtyped and the
-                // opaque type contains lifetime variables that get subtyped.
-                iter::once(either::Right(either::Left([1])))
-                    .chain(std::iter::once([1]).map(either::Right).map(either::Right)),
-            ),
-        }
-    }
-}
-
-pub struct BabeNextEpochRef<'a>(&'a ());
-
-impl<'a> BabeNextEpochRef<'a> {
-    pub fn scale_encoding(
-        &self,
-    ) -> impl Iterator<Item = impl AsRef<[u8]> + Clone + 'a> + Clone + 'a {
-        std::iter::once([1])
+//@ check-pass
+
+fn foo() -> impl Default + Copy {
+    if false {
+        let x = Default::default();
+        // add `Subtype(?x, ?y)` obligation
+        let y = x;
+
+        // Make a tuple `(?x, ?y)` and equate it with `(impl Default, u32)`.
+        // For us to try and prove a `Subtype(impl Default, u32)` obligation,
+        // we have to instantiate both `?x` and `?y` without any
+        // `select_where_possible` calls inbetween.
+        let mut tup = &mut (x, y);
+        let assign_tup = &mut (foo(), 1u32);
+        tup = assign_tup;
     }
+    1u32
 }
 
 fn main() {}

tests/ui/type-alias-impl-trait/lazy_subtyping_of_opaques.rs

@@ -7,9 +7,10 @@
 type Tait = impl FnOnce() -> ();
 
 fn reify_as_tait() -> Thunk<Tait> {
+    //~^ ERROR: expected a `FnOnce()` closure, found `()`
     Thunk::new(|cont| cont)
     //~^ ERROR: mismatched types
-    //~| ERROR: mismatched types
+    //~| ERROR: expected a `FnOnce()` closure, found `()`
 }
 
 struct Thunk<F>(F);

tests/ui/type-alias-impl-trait/lazy_subtyping_of_opaques.stderr

@@ -1,26 +1,31 @@
-error[E0308]: mismatched types
-  --> $DIR/lazy_subtyping_of_opaques.rs:10:23
+error[E0277]: expected a `FnOnce()` closure, found `()`
+  --> $DIR/lazy_subtyping_of_opaques.rs:11:23
    |
-LL | type Tait = impl FnOnce() -> ();
-   |             ------------------- the found opaque type
-...
 LL |     Thunk::new(|cont| cont)
-   |                       ^^^^ expected `()`, found opaque type
+   |                       ^^^^ expected an `FnOnce()` closure, found `()`
    |
-   = note: expected unit type `()`
-            found opaque type `Tait`
+   = help: the trait `FnOnce()` is not implemented for `()`
+   = note: wrap the `()` in a closure with no arguments: `|| { /* code */ }`
 
-error[E0308]: mismatched types
-  --> $DIR/lazy_subtyping_of_opaques.rs:10:5
+error[E0277]: expected a `FnOnce()` closure, found `()`
+  --> $DIR/lazy_subtyping_of_opaques.rs:9:23
    |
 LL | fn reify_as_tait() -> Thunk<Tait> {
-   |                       ----------- expected `Thunk<_>` because of return type
+   |                       ^^^^^^^^^^^ expected an `FnOnce()` closure, found `()`
+   |
+   = help: the trait `FnOnce()` is not implemented for `()`
+   = note: wrap the `()` in a closure with no arguments: `|| { /* code */ }`
+
+error[E0308]: mismatched types
+  --> $DIR/lazy_subtyping_of_opaques.rs:11:5
+   |
 LL |     Thunk::new(|cont| cont)
    |     ^^^^^^^^^^^^^^^^^^^^^^^ expected `Thunk<_>`, found `()`
    |
    = note: expected struct `Thunk<_>`
            found unit type `()`
 
-error: aborting due to 2 previous errors
+error: aborting due to 3 previous errors
 
-For more information about this error, try `rustc --explain E0308`.
+Some errors have detailed explanations: E0277, E0308.
+For more information about an error, try `rustc --explain E0277`.