Auto merge of #144087 - cuviper:beta-next, r=cuviper

[beta] backports

- Taint body on invalid call ABI #142983
- Fix rustdoc not correctly showing attributes with re-exports #143083
- trait_sel: `MetaSized` always holds temporarily #144016
- Ensure home directory exists #144003

r? cuviper

Author: bors

.github/workflows/ci.yml

@@ -190,6 +190,11 @@ jobs:
       - name: install MinGW
         run: src/ci/scripts/install-mingw.sh
 
+      # Workaround for spurious ci failures after mingw install
+      # see https://rust-lang.zulipchat.com/#narrow/channel/242791-t-infra/topic/Spurious.20bors.20CI.20failures/near/528915775
+      - name: ensure home dir exists
+        run: mkdir -p ~
+
       - name: install ninja
         run: src/ci/scripts/install-ninja.sh
 

compiler/rustc_abi/src/extern_abi.rs

@@ -36,6 +36,10 @@ pub enum ExternAbi {
     /// Stronger than just `#[cold]` because `fn` pointers might be incompatible.
     RustCold,
 
+    /// An always-invalid ABI that's used to test "this ABI is not supported by this platform"
+    /// in a platform-agnostic way.
+    RustInvalid,
+
     /// Unstable impl detail that directly uses Rust types to describe the ABI to LLVM.
     /// Even normally-compatible Rust types can become ABI-incompatible with this ABI!
     Unadjusted,
@@ -157,6 +161,7 @@ abi_impls! {
             RiscvInterruptS =><= "riscv-interrupt-s",
             RustCall =><= "rust-call",
             RustCold =><= "rust-cold",
+            RustInvalid =><= "rust-invalid",
             Stdcall { unwind: false } =><= "stdcall",
             Stdcall { unwind: true } =><= "stdcall-unwind",
             System { unwind: false } =><= "system",

compiler/rustc_ast_lowering/src/stability.rs

@@ -96,6 +96,9 @@ pub fn extern_abi_stability(abi: ExternAbi) -> Result<(), UnstableAbi> {
         ExternAbi::RustCold => {
             Err(UnstableAbi { abi, feature: sym::rust_cold_cc, explain: GateReason::Experimental })
         }
+        ExternAbi::RustInvalid => {
+            Err(UnstableAbi { abi, feature: sym::rustc_attrs, explain: GateReason::ImplDetail })
+        }
         ExternAbi::GpuKernel => Err(UnstableAbi {
             abi,
             feature: sym::abi_gpu_kernel,

compiler/rustc_hir_typeck/src/callee.rs

@@ -156,7 +156,16 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     pub(crate) fn check_call_abi(&self, abi: ExternAbi, span: Span) {
         let canon_abi = match AbiMap::from_target(&self.sess().target).canonize_abi(abi, false) {
             AbiMapping::Direct(canon_abi) | AbiMapping::Deprecated(canon_abi) => canon_abi,
-            AbiMapping::Invalid => return,
+            AbiMapping::Invalid => {
+                // This should be reported elsewhere, but we want to taint this body
+                // so that we don't try to evaluate calls to ABIs that are invalid.
+                let guar = self.dcx().span_delayed_bug(
+                    span,
+                    format!("invalid abi for platform should have reported an error: {abi}"),
+                );
+                self.set_tainted_by_errors(guar);
+                return;
+            }
         };
 
         let valid = match canon_abi {

compiler/rustc_middle/src/ty/layout.rs

@@ -1253,7 +1253,8 @@ pub fn fn_can_unwind(tcx: TyCtxt<'_>, fn_def_id: Option<DefId>, abi: ExternAbi)
         | CCmseNonSecureCall
         | CCmseNonSecureEntry
         | Custom
-        | Unadjusted => false,
+        | Unadjusted
+        | RustInvalid => false,
         Rust | RustCall | RustCold => tcx.sess.panic_strategy() == PanicStrategy::Unwind,
     }
 }

compiler/rustc_smir/src/rustc_internal/internal.rs

@@ -494,6 +494,7 @@ impl RustcInternal for Abi {
             Abi::RustCall => rustc_abi::ExternAbi::RustCall,
             Abi::Unadjusted => rustc_abi::ExternAbi::Unadjusted,
             Abi::RustCold => rustc_abi::ExternAbi::RustCold,
+            Abi::RustInvalid => rustc_abi::ExternAbi::RustInvalid,
             Abi::RiscvInterruptM => rustc_abi::ExternAbi::RiscvInterruptM,
             Abi::RiscvInterruptS => rustc_abi::ExternAbi::RiscvInterruptS,
             Abi::Custom => rustc_abi::ExternAbi::Custom,

compiler/rustc_smir/src/rustc_smir/convert/ty.rs

@@ -877,6 +877,7 @@ impl<'tcx> Stable<'tcx> for rustc_abi::ExternAbi {
             ExternAbi::RustCall => Abi::RustCall,
             ExternAbi::Unadjusted => Abi::Unadjusted,
             ExternAbi::RustCold => Abi::RustCold,
+            ExternAbi::RustInvalid => Abi::RustInvalid,
             ExternAbi::RiscvInterruptM => Abi::RiscvInterruptM,
             ExternAbi::RiscvInterruptS => Abi::RiscvInterruptS,
             ExternAbi::Custom => Abi::Custom,

compiler/rustc_smir/src/stable_mir/ty.rs

@@ -1126,6 +1126,7 @@ pub enum Abi {
     RustCold,
     RiscvInterruptM,
     RiscvInterruptS,
+    RustInvalid,
     Custom,
 }
 

compiler/rustc_target/src/spec/abi_map.rs

@@ -156,7 +156,8 @@ impl AbiMap {
                 | ExternAbi::Msp430Interrupt
                 | ExternAbi::RiscvInterruptM
                 | ExternAbi::RiscvInterruptS
-                | ExternAbi::X86Interrupt,
+                | ExternAbi::X86Interrupt
+                | ExternAbi::RustInvalid,
                 _,
             ) => return AbiMapping::Invalid,
         };

compiler/rustc_trait_selection/src/traits/util.rs

@@ -377,6 +377,13 @@ pub fn sizedness_fast_path<'tcx>(tcx: TyCtxt<'tcx>, predicate: ty::Predicate<'tc
             _ => return false,
         };
 
+        // FIXME(sized_hierarchy): this temporarily reverts the `sized_hierarchy` feature
+        // while a proper fix for `tests/ui/sized-hierarchy/incomplete-inference-issue-143992.rs`
+        // is pending a proper fix
+        if !tcx.features().sized_hierarchy() && matches!(sizedness, SizedTraitKind::MetaSized) {
+            return true;
+        }
+
         if trait_ref.self_ty().has_trivial_sizedness(tcx, sizedness) {
             debug!("fast path -- trivial sizedness");
             return true;