Auto merge of #17609 - lnicola:sync-from-rust, r=lnicola

minor: Sync from downstream

3 files changed, 11 insertions, 16 deletions

diff --git a/compiler/rustc_codegen_llvm/src/attributes.rs b/compiler/rustc_codegen_llvm/src/attributes.rs
index cd82894af18..e7669470026 100644
--- a/compiler/rustc_codegen_llvm/src/attributes.rs
+++ b/compiler/rustc_codegen_llvm/src/attributes.rs
@@ -6,7 +6,6 @@ use rustc_middle::middle::codegen_fn_attrs::{CodegenFnAttrFlags, PatchableFuncti
 use rustc_middle::ty::{self, TyCtxt};
 use rustc_session::config::{FunctionReturn, OptLevel};
 use rustc_span::symbol::sym;
-use rustc_target::spec::abi::Abi;
 use rustc_target::spec::{FramePointer, SanitizerSet, StackProbeType, StackProtector};
 use smallvec::SmallVec;
 
@@ -482,7 +481,7 @@ pub fn from_fn_attrs<'ll, 'tcx>(
         return;
     }
 
-    let mut function_features = function_features
+    let function_features = function_features
         .iter()
         .flat_map(|feat| {
             llvm_util::to_llvm_features(cx.tcx.sess, feat).into_iter().map(|f| format!("+{f}"))
@@ -504,17 +503,6 @@ pub fn from_fn_attrs<'ll, 'tcx>(
             let name = name.as_str();
             to_add.push(llvm::CreateAttrStringValue(cx.llcx, "wasm-import-name", name));
         }
-
-        // The `"wasm"` abi on wasm targets automatically enables the
-        // `+multivalue` feature because the purpose of the wasm abi is to match
-        // the WebAssembly specification, which has this feature. This won't be
-        // needed when LLVM enables this `multivalue` feature by default.
-        if !cx.tcx.is_closure_like(instance.def_id()) {
-            let abi = cx.tcx.fn_sig(instance.def_id()).skip_binder().abi();
-            if abi == Abi::Wasm {
-                function_features.push("+multivalue".to_string());
-            }
-        }
     }
 
     let global_features = cx.tcx.global_backend_features(()).iter().map(|s| s.as_str());
diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/map_data.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/map_data.rs
index b969fe27a99..14a94468587 100644
--- a/compiler/rustc_codegen_llvm/src/coverageinfo/map_data.rs
+++ b/compiler/rustc_codegen_llvm/src/coverageinfo/map_data.rs
@@ -66,8 +66,15 @@ impl<'tcx> FunctionCoverageCollector<'tcx> {
         // For each expression ID that is directly used by one or more mappings,
         // mark it as not-yet-seen. This indicates that we expect to see a
         // corresponding `ExpressionUsed` statement during MIR traversal.
-        for term in function_coverage_info.mappings.iter().flat_map(|m| m.kind.terms()) {
-            if let CovTerm::Expression(id) = term {
+        for mapping in function_coverage_info.mappings.iter() {
+            // Currently we only worry about ordinary code mappings.
+            // For branch and MC/DC mappings, expressions might not correspond
+            // to any particular point in the control-flow graph.
+            // (Keep this in sync with the injection of `ExpressionUsed`
+            // statements in the `InstrumentCoverage` MIR pass.)
+            if let MappingKind::Code(term) = mapping.kind
+                && let CovTerm::Expression(id) = term
+            {
                 expressions_seen.remove(id);
             }
         }
diff --git a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
index 08e9e312827..e0bf6110cdf 100644
--- a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
@@ -2057,7 +2057,7 @@ extern "C" {
         AddrOpsCount: c_uint,
         DL: &'a DILocation,
         InsertAtEnd: &'a BasicBlock,
-    ) -> &'a Value;
+    );
 
     pub fn LLVMRustDIBuilderCreateEnumerator<'a>(
         Builder: &DIBuilder<'a>,