Brem methods dont copy return

score/mw/com/impl/methods/BUILD

@@ -28,6 +28,17 @@ cc_library(
     ],
 )
 
+cc_library(
+    name = "method_handler_checker",
+    srcs = ["method_handler_checker.cpp"],
+    hdrs = ["method_handler_checker.h"],
+    features = COMPILER_WARNING_FEATURES,
+    tags = ["FFI"],
+    visibility = [
+        "//score/mw/com:__subpackages__",
+    ],
+)
+
 cc_library(
     name = "proxy_method_base",
     srcs = ["proxy_method_base.cpp"],
@@ -186,6 +197,7 @@ cc_gtest_unit_test(
         ":skeleton_method",
         "//score/mw/com/impl/bindings/mock_binding",
         "//score/mw/com/impl/plumbing:skeleton_method_binding_factory_mock",
+        "//score/mw/com/impl/test:binding_factory_resources",
         "@score_baselibs//score/language/futurecpp",
     ],
 )

score/mw/com/impl/methods/compile_tests/BUILD

@@ -0,0 +1,19 @@
+load(":compile_fail.bzl", "compile_fail_test")
+load("@score_baselibs//:bazel/unit_tests.bzl", "cc_unit_test_suites_for_host_and_qnx")
+
+compile_fail_test(
+    name = "method_handler_checker_compile_fail_test",
+    src = "method_handler_checker_test.cpp",
+    src_path = "score/mw/com/impl/methods/compile_tests/method_handler_checker_test.cpp",
+    deps = [
+        "//score/mw/com/impl/methods:method_handler_checker",
+    ],
+)
+
+cc_unit_test_suites_for_host_and_qnx(
+    name = "unit_test_suite",
+    cc_unit_tests = [
+        ":method_handler_checker_compile_fail_test",
+    ],
+    visibility = ["//score/mw/com/impl/methods:__pkg__"],
+)

score/mw/com/impl/methods/compile_tests/compile_fail.bzl

@@ -0,0 +1,158 @@
+"""Rule for compile-fail tests: a test passes if and only if its source file fails to compile."""
+
+load("@bazel_tools//tools/cpp:toolchain_utils.bzl", "find_cpp_toolchain", "use_cpp_toolchain")
+
+# Stable action-name string; avoids a dep on @rules_cc//cc:action_names.bzl.
+_CPP_COMPILE_ACTION = "c++-compile"
+
+def _compile_fail_test_impl(ctx):
+    cc_toolchain = find_cpp_toolchain(ctx)
+    feature_configuration = cc_common.configure_features(
+        ctx = ctx,
+        cc_toolchain = cc_toolchain,
+        requested_features = ctx.features,
+        unsupported_features = ctx.disabled_features,
+    )
+
+    compiler = cc_common.get_tool_for_action(
+        feature_configuration = feature_configuration,
+        action_name = _CPP_COMPILE_ACTION,
+    )
+
+    compilation_contexts = [
+        dep[CcInfo].compilation_context
+        for dep in ctx.attr.deps
+        if CcInfo in dep
+    ]
+    merged = cc_common.merge_compilation_contexts(
+        compilation_contexts = compilation_contexts,
+    )
+
+    # Include paths from the compilation context are exec-root-relative.
+    # At test time, we resolve them against runfiles.
+    flag_lines = ["flags=()"]
+    for path in merged.includes.to_list():
+        flag_lines.append('flags+=( -I"$(resolve_data_path \"{p}\")" )'.format(p = path))
+    for path in merged.quote_includes.to_list():
+        flag_lines.append('flags+=( -iquote "$(resolve_data_path \"{p}\")" )'.format(p = path))
+    for path in merged.system_includes.to_list():
+        flag_lines.append('flags+=( -isystem "$(resolve_data_path \"{p}\")" )'.format(p = path))
+    for define in merged.defines.to_list():
+        flag_lines.append('flags+=( -D"{d}" )'.format(d = define))
+    for copt in ctx.attr.copts:
+        flag_lines.append("flags+=( {c} )".format(c = copt))
+
+    # Add generic include roots for workspace headers.
+    flag_lines.append('flags+=( -iquote "$(resolve_data_path .)" )')
+    flag_lines.append('flags+=( -iquote "$TEST_SRCDIR/$TEST_WORKSPACE" )')
+
+    # The test script inverts the compiler exit code:
+    #   compile succeeds → test fails
+    #   compile fails    → test passes
+    test_script = ctx.actions.declare_file(ctx.label.name)
+    ctx.actions.write(
+        output = test_script,
+        content = """\
+#!/usr/bin/env bash
+set -uo pipefail
+
+resolve_data_path() {{
+    local p="$1"
+    if [[ -e "$TEST_SRCDIR/$p" ]]; then
+        echo "$TEST_SRCDIR/$p"
+        return 0
+    fi
+    if [[ -n "${{TEST_WORKSPACE:-}}" && -e "$TEST_SRCDIR/$TEST_WORKSPACE/$p" ]]; then
+        echo "$TEST_SRCDIR/$TEST_WORKSPACE/$p"
+        return 0
+    fi
+    echo "$TEST_SRCDIR/$p"
+    return 0
+}}
+
+resolve_exec_path() {{
+    local p="$1"
+    if [[ -x "$p" ]]; then
+        echo "$p"
+        return 0
+    fi
+    if [[ -x "$TEST_SRCDIR/$p" ]]; then
+        echo "$TEST_SRCDIR/$p"
+        return 0
+    fi
+    if [[ -n "${{TEST_WORKSPACE:-}}" && -x "$TEST_SRCDIR/$TEST_WORKSPACE/$p" ]]; then
+        echo "$TEST_SRCDIR/$TEST_WORKSPACE/$p"
+        return 0
+    fi
+    return 1
+}}
+
+src="$(resolve_data_path \"{src}\")"
+compiler=""
+if compiler_candidate="$(resolve_exec_path \"{compiler}\")"; then
+    compiler="$compiler_candidate"
+else
+    compiler="$(command -v c++ || command -v g++)"
+fi
+
+if [[ -z "$compiler" ]]; then
+    echo "FAILED: compiler '{compiler}' not found/executable in runfiles and no c++/g++ in PATH."
+    exit 2
+fi
+
+if [[ ! -f "$src" ]]; then
+    echo "FAILED: source '{src}' not found in runfiles."
+    exit 2
+fi
+
+{flag_lines}
+if "$compiler" "${{flags[@]}}" -c "$src" -o /dev/null 2>/dev/null; then
+    echo "FAILED: expected a compile error, but '{src}' compiled successfully."
+    exit 1
+fi
+echo "PASSED: '{src}' failed to compile as expected."
+exit 0
+""".format(
+            src = ctx.attr.src_path,
+            compiler = compiler,
+            flag_lines = "\n".join(flag_lines),
+        ),
+        is_executable = True,
+    )
+
+    runfiles = ctx.runfiles(
+        files = [ctx.file.src],
+        transitive_files = depset(transitive = [
+            cc_toolchain.all_files,
+            merged.headers,
+        ]),
+    )
+    return [DefaultInfo(executable = test_script, runfiles = runfiles)]
+
+compile_fail_test = rule(
+    implementation = _compile_fail_test_impl,
+    attrs = {
+        "src": attr.label(
+            mandatory = True,
+            allow_single_file = [".cpp", ".cc", ".cxx"],
+            doc = "The C++ source file expected to fail compilation.",
+        ),
+        "src_path": attr.string(
+            mandatory = True,
+            doc = "Runfiles-relative path of the source file to compile.",
+        ),
+        "deps": attr.label_list(
+            providers = [CcInfo],
+            doc = "C++ library dependencies.",
+        ),
+        "copts": attr.string_list(
+            doc = "Additional compiler flags.",
+        ),
+        "_cc_toolchain": attr.label(
+            default = Label("@bazel_tools//tools/cpp:current_cc_toolchain"),
+        ),
+    },
+    test = True,
+    fragments = ["cpp"],
+    toolchains = use_cpp_toolchain(),
+)

score/mw/com/impl/methods/compile_tests/method_handler_checker_test.cpp

@@ -0,0 +1,10 @@
+#include "score/mw/com/impl/methods/method_handler_checker.h"
+
+#include <functional>
+
+int main()
+{
+    score::mw::com::impl::
+        AssertCallableMatchesMethodSignature<std::function<void(int&, const int&, const double&)>, int, int, double>();
+    return 0;
+}

score/mw/com/impl/methods/method_handler_checker.cpp

@@ -0,0 +1,13 @@
+/********************************************************************************
+ * Copyright (c) 2025 Contributors to the Eclipse Foundation
+ *
+ * See the NOTICE file(s) distributed with this work for additional
+ * information regarding copyright ownership.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ********************************************************************************/
+#include "score/mw/com/impl/methods/method_handler_checker.h"