From: Arthur Cohen <arthur.co...@embecosm.com>
gcc/rust/ChangeLog:
* expand/rust-derive-cmp-common.cc: New file.
* expand/rust-derive-cmp-common.h: New file.
* Make-lang.in: Compile them.
---
gcc/rust/Make-lang.in | 1 +
gcc/rust/expand/rust-derive-cmp-common.cc | 69 +++++++++++++++++++++++
gcc/rust/expand/rust-derive-cmp-common.h | 50 ++++++++++++++++
3 files changed, 120 insertions(+)
create mode 100644 gcc/rust/expand/rust-derive-cmp-common.cc
create mode 100644 gcc/rust/expand/rust-derive-cmp-common.h
diff --git a/gcc/rust/Make-lang.in b/gcc/rust/Make-lang.in
index c919b3d43e2..85614b3e224 100644
--- a/gcc/rust/Make-lang.in
+++ b/gcc/rust/Make-lang.in
@@ -94,6 +94,7 @@ GRS_OBJS = \
rust/rust-ast-builder.o \
rust/rust-ast-builder-type.o \
rust/rust-derive.o \
+ rust/rust-derive-cmp-common.o \
rust/rust-derive-clone.o \
rust/rust-derive-copy.o \
rust/rust-derive-debug.o \
diff --git a/gcc/rust/expand/rust-derive-cmp-common.cc
b/gcc/rust/expand/rust-derive-cmp-common.cc
new file mode 100644
index 00000000000..ba260c53291
--- /dev/null
+++ b/gcc/rust/expand/rust-derive-cmp-common.cc
@@ -0,0 +1,69 @@
+// Copyright (C) 2025 Free Software Foundation, Inc.
+
+// This file is part of GCC.
+
+// GCC is free software; you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free
+// Software Foundation; either version 3, or (at your option) any later
+// version.
+
+// GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+// for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with GCC; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+#include "rust-derive-cmp-common.h"
+#include "rust-ast-builder.h"
+
+namespace Rust {
+namespace AST {
+
+SelfOther
+SelfOther::index (Builder builder, int idx)
+{
+ return SelfOther{
+ builder.tuple_idx ("self", idx),
+ builder.tuple_idx ("other", idx),
+ };
+}
+
+std::vector<SelfOther>
+SelfOther::indexes (Builder builder, int limit)
+{
+ std::vector<SelfOther> vec;
+
+ for (int i = 0; i < limit; i++)
+ {
+ vec.emplace_back (SelfOther::index (builder, i));
+ }
+
+ return vec;
+}
+
+SelfOther
+SelfOther::field (Builder builder, const std::string &field_name)
+{
+ return SelfOther{
+ builder.field_access (builder.identifier ("self"), field_name),
+ builder.field_access (builder.identifier ("other"), field_name),
+ };
+}
+
+std::vector<SelfOther>
+SelfOther::fields (Builder builder, const std::vector<StructField> &fields)
+{
+ std::vector<SelfOther> vec;
+
+ for (auto &field : fields)
+ vec.emplace_back (
+ SelfOther::field (builder, field.get_field_name ().as_string ()));
+
+ return vec;
+}
+
+} // namespace AST
+} // namespace Rust
diff --git a/gcc/rust/expand/rust-derive-cmp-common.h
b/gcc/rust/expand/rust-derive-cmp-common.h
new file mode 100644
index 00000000000..2353c71292f
--- /dev/null
+++ b/gcc/rust/expand/rust-derive-cmp-common.h
@@ -0,0 +1,50 @@
+// Copyright (C) 2025 Free Software Foundation, Inc.
+
+// This file is part of GCC.
+
+// GCC is free software; you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free
+// Software Foundation; either version 3, or (at your option) any later
+// version.
+
+// GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+// for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with GCC; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+#ifndef RUST_DERIVE_CMP_COMMON_H
+#define RUST_DERIVE_CMP_COMMON_H
+
+#include "rust-ast.h"
+#include "rust-ast-builder.h"
+
+namespace Rust {
+namespace AST {
+
+/**
+ * A pair of two expressions from each instance being compared. E.g. this
+ * could be `self.0` and `other.0`, or `self.field` and `other.field`
+ */
+struct SelfOther
+{
+ std::unique_ptr<Expr> self_expr;
+ std::unique_ptr<Expr> other_expr;
+
+ /* Create a <self.i> and an <other.i> expression */
+ static SelfOther index (Builder builder, int idx);
+ static std::vector<SelfOther> indexes (Builder builder, int limit);
+
+ /* Create a <self.field> and an <other.field> expression */
+ static SelfOther field (Builder builder, const std::string &field_name);
+ static std::vector<SelfOther> fields (Builder builder,
+ const std::vector<StructField> &fields);
+};
+
+} // namespace AST
+} // namespace Rust
+
+#endif // ! RUST_DERIVE_CMP_COMMON_H
--
2.49.0
