Rollup merge of rust-lang#139782 - xizheyin:issue-139627, r=wesleywiser

Consistent with treating Ctor Call as Struct in liveness analysis

Fixes rust-lang#139627

When `ExprKind::Call` is a `Ctor`, skips the checking of `expr` and only checks the arguments, thus being consistent with `ExprKind::Struct`.

r? compiler

Author: matthiaskrgr

compiler/rustc_passes/src/liveness.rs

@@ -1020,7 +1020,10 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {
             }
 
             hir::ExprKind::Call(ref f, args) => {
-                let succ = self.check_is_ty_uninhabited(expr, succ);
+                let is_ctor = |f: &Expr<'_>| matches!(f.kind, hir::ExprKind::Path(hir::QPath::Resolved(_, path)) if matches!(path.res, rustc_hir::def::Res::Def(rustc_hir::def::DefKind::Ctor(_, _), _)));
+                let succ =
+                    if !is_ctor(f) { self.check_is_ty_uninhabited(expr, succ) } else { succ };
+
                 let succ = self.propagate_through_exprs(args, succ);
                 self.propagate_through_expr(f, succ)
             }

tests/ui/reachable/unreachable-by-call-arguments-issue-139627.rs

@@ -0,0 +1,16 @@
+//@ check-pass
+#![deny(unreachable_code)]
+#![deny(unused)]
+
+pub enum Void {}
+
+pub struct S<T>(T);
+
+pub fn foo(void: Void, void1: Void) {
+    let s = S(void);
+    drop(s);
+    let s1 = S { 0: void1 };
+    drop(s1);
+}
+
+fn main() {}