[gcc r16-2977] gccrs: Fix AttrInputMacro operator= overloading.

[Arthur Cohen via Gcc-cvs]

https://gcc.gnu.org/g:e705ad248a22d4a6d7bb54655bf71d5b6404382d

commit r16-2977-ge705ad248a22d4a6d7bb54655bf71d5b6404382d
Author: Pierre-Emmanuel Patry <pierre-emmanuel.pa...@embecosm.com>
Date:   Thu Jul 31 13:19:22 2025 +0200

    gccrs: Fix AttrInputMacro operator= overloading.
    
    gcc/rust/ChangeLog:
    
            * ast/rust-ast.cc (AttrInputMacro::operator=): Add return type.
            * ast/rust-expr.h: Likewise.
    
    Signed-off-by: Pierre-Emmanuel Patry <pierre-emmanuel.pa...@embecosm.com>

Diff:
---
 gcc/rust/ast/rust-ast.cc | 3 ++-
 gcc/rust/ast/rust-expr.h | 8 ++++++--
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/gcc/rust/ast/rust-ast.cc b/gcc/rust/ast/rust-ast.cc
index ec1596bfb978..20a41d72cdfc 100644
--- a/gcc/rust/ast/rust-ast.cc
+++ b/gcc/rust/ast/rust-ast.cc
@@ -4339,11 +4339,12 @@ AttrInputMacro::AttrInputMacro (const AttrInputMacro 
&oth)
   : macro (oth.macro->clone_macro_invocation_impl ())
 {}
 
-void
+AttrInputMacro &
 AttrInputMacro::operator= (const AttrInputMacro &oth)
 {
   macro = std::unique_ptr<MacroInvocation> (
     oth.macro->clone_macro_invocation_impl ());
+  return *this;
 }
 
 /* Visitor implementations - these are short but inlining can't happen anyway
diff --git a/gcc/rust/ast/rust-expr.h b/gcc/rust/ast/rust-expr.h
index 4644e8dcec77..c8f776481b58 100644
--- a/gcc/rust/ast/rust-expr.h
+++ b/gcc/rust/ast/rust-expr.h
@@ -183,9 +183,13 @@ public:
 
   AttrInputMacro (AttrInputMacro &&oth) : macro (std::move (oth.macro)) {}
 
-  void operator= (const AttrInputMacro &oth);
+  AttrInputMacro &operator= (const AttrInputMacro &oth);
 
-  void operator= (AttrInputMacro &&oth) { macro = std::move (oth.macro); }
+  AttrInputMacro &operator= (AttrInputMacro &&oth)
+  {
+    macro = std::move (oth.macro);
+    return *this;
+  }
 
   std::string as_string () const override;