[Cpp Parser] Support function param adjust and merge entity

cpp/libclang/integration_test/cases/forward_declared_interface_merge/BUILD

@@ -0,0 +1,25 @@
+# *******************************************************************************
+# Copyright (c) 2026 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
+# *******************************************************************************
+load("//cpp/libclang/integration_test:test_rules.bzl", "cpp_parser_integration_test")
+
+cc_library(
+    name = "forward_declared_interface_merge",
+    srcs = glob(["*.cpp"]),
+    visibility = ["//cpp/libclang:__subpackages__"],
+)
+
+cpp_parser_integration_test(
+    name = "test_forward_declared_interface_merge",
+    expected_output = ["expected.json"],
+    target = ":forward_declared_interface_merge",
+)

cpp/libclang/integration_test/cases/forward_declared_interface_merge/a_full_definition.cpp

@@ -0,0 +1,18 @@
+/********************************************************************************
+ * Copyright (c) 2026 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
+ ********************************************************************************/
+class IThing
+{
+  public:
+    virtual ~IThing() = default;
+    virtual void run() = 0;
+};

cpp/libclang/integration_test/cases/forward_declared_interface_merge/b_forward_declaration.cpp

@@ -0,0 +1,15 @@
+/********************************************************************************
+ * Copyright (c) 2026 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
+ ********************************************************************************/
+class IThing;
+
+void use_thing(IThing *thing) {}

cpp/libclang/integration_test/cases/forward_declared_interface_merge/expected.json

@@ -0,0 +1,84 @@
+{
+    "types": {
+        "IThing": {
+            "id": "IThing",
+            "name": "IThing",
+            "enclosing_namespace_id": null,
+            "stereotypes": [],
+            "entity_type": "Interface",
+            "type_aliases": [],
+            "variables": [],
+            "methods": [
+                {
+                    "name": "~IThing",
+                    "return_type": null,
+                    "visibility": "public",
+                    "parameters": [],
+                    "template_parameters": null,
+                    "modifiers": [
+                        "Virtual",
+                        "Destructor"
+                    ],
+                    "source_location": {
+                        "file": "cpp/libclang/integration_test/cases/forward_declared_interface_merge/a_full_definition.cpp",
+                        "line": 16
+                    }
+                },
+                {
+                    "name": "run",
+                    "return_type": "void",
+                    "visibility": "public",
+                    "parameters": [],
+                    "template_parameters": null,
+                    "modifiers": [
+                        "Virtual",
+                        "Abstract"
+                    ],
+                    "source_location": {
+                        "file": "cpp/libclang/integration_test/cases/forward_declared_interface_merge/a_full_definition.cpp",
+                        "line": 17
+                    }
+                }
+            ],
+            "template_parameters": null,
+            "enum_literals": [],
+            "relationships": [],
+            "source_location": {
+                "file": "cpp/libclang/integration_test/cases/forward_declared_interface_merge/a_full_definition.cpp",
+                "line": 13
+            }
+        }
+    },
+    "free_function_declarations": [
+        {
+            "name": "use_thing",
+            "enclosing_namespace_id": null,
+            "return_type": "void",
+            "parameters": [
+                {
+                    "name": "thing",
+                    "param_type": "IThing *",
+                    "is_variadic": false
+                }
+            ],
+            "template_parameters": null,
+            "source_location": {
+                "file": "cpp/libclang/integration_test/cases/forward_declared_interface_merge/b_forward_declaration.cpp",
+                "line": 15
+            }
+        }
+    ],
+    "functions": [
+        {
+            "id": {
+                "scope": "Global",
+                "name": "use_thing"
+            },
+            "kind": "Free",
+            "return_type": {
+                "Builtin": "void"
+            },
+            "body": []
+        }
+    ]
+}

cpp/libclang/integration_test/cases/forward_declared_interface_merge/run_test.rs

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+// *******************************************************************************
+// Copyright (c) 2026 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
+// *******************************************************************************
+
+use test_framework::run_parser_case;
+
+#[test]
+fn test_forward_declared_interface_merge() {
+    run_parser_case();
+}

cpp/libclang/integration_test/function_cases/overload_signedness_identity/BUILD

@@ -0,0 +1,26 @@
+# *******************************************************************************
+# Copyright (c) 2026 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
+# *******************************************************************************
+load("//cpp/libclang/integration_test:test_rules.bzl", "cpp_parser_integration_test")
+
+cc_library(
+    name = "overload_signedness_identity",
+    srcs = ["functions.cpp"],
+    hdrs = ["functions.hpp"],
+    visibility = ["//cpp/libclang:__subpackages__"],
+)
+
+cpp_parser_integration_test(
+    name = "test_overload_signedness_identity",
+    expected_output = ["expected.json"],
+    target = ":overload_signedness_identity",
+)

cpp/libclang/integration_test/function_cases/overload_signedness_identity/expected.json

@@ -0,0 +1,119 @@
+{
+    "types": {},
+    "free_function_declarations": [
+        {
+            "name": "fixed_width",
+            "enclosing_namespace_id": null,
+            "return_type": "void",
+            "parameters": [
+                {
+                    "name": "",
+                    "param_type": "std::int32_t",
+                    "is_variadic": false
+                }
+            ],
+            "template_parameters": null,
+            "source_location": {
+                "file": "cpp/libclang/integration_test/function_cases/overload_signedness_identity/functions.hpp",
+                "line": 19
+            }
+        },
+        {
+            "name": "fixed_width",
+            "enclosing_namespace_id": null,
+            "return_type": "void",
+            "parameters": [
+                {
+                    "name": "",
+                    "param_type": "std::uint32_t",
+                    "is_variadic": false
+                }
+            ],
+            "template_parameters": null,
+            "source_location": {
+                "file": "cpp/libclang/integration_test/function_cases/overload_signedness_identity/functions.hpp",
+                "line": 20
+            }
+        },
+        {
+            "name": "size_vs_long",
+            "enclosing_namespace_id": null,
+            "return_type": "void",
+            "parameters": [
+                {
+                    "name": "",
+                    "param_type": "long",
+                    "is_variadic": false
+                }
+            ],
+            "template_parameters": null,
+            "source_location": {
+                "file": "cpp/libclang/integration_test/function_cases/overload_signedness_identity/functions.hpp",
+                "line": 21
+            }
+        },
+        {
+            "name": "size_vs_long",
+            "enclosing_namespace_id": null,
+            "return_type": "void",
+            "parameters": [
+                {
+                    "name": "",
+                    "param_type": "std::size_t",
+                    "is_variadic": false
+                }
+            ],
+            "template_parameters": null,
+            "source_location": {
+                "file": "cpp/libclang/integration_test/function_cases/overload_signedness_identity/functions.hpp",
+                "line": 22
+            }
+        }
+    ],
+    "functions": [
+        {
+            "id": {
+                "scope": "Global",
+                "name": "fixed_width"
+            },
+            "kind": "Free",
+            "return_type": {
+                "Builtin": "void"
+            },
+            "body": []
+        },
+        {
+            "id": {
+                "scope": "Global",
+                "name": "fixed_width"
+            },
+            "kind": "Free",
+            "return_type": {
+                "Builtin": "void"
+            },
+            "body": []
+        },
+        {
+            "id": {
+                "scope": "Global",
+                "name": "size_vs_long"
+            },
+            "kind": "Free",
+            "return_type": {
+                "Builtin": "void"
+            },
+            "body": []
+        },
+        {
+            "id": {
+                "scope": "Global",
+                "name": "size_vs_long"
+            },
+            "kind": "Free",
+            "return_type": {
+                "Builtin": "void"
+            },
+            "body": []
+        }
+    ]
+}

cpp/libclang/integration_test/function_cases/overload_signedness_identity/functions.cpp

@@ -0,0 +1,19 @@
+/********************************************************************************
+ * Copyright (c) 2026 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 "functions.hpp"
+
+void fixed_width(std::int32_t value) {}
+void fixed_width(std::uint32_t value) {}
+void size_vs_long(long value) {}
+void size_vs_long(std::size_t value) {}

cpp/libclang/integration_test/function_cases/overload_signedness_identity/functions.hpp

@@ -0,0 +1,22 @@
+/********************************************************************************
+ * Copyright (c) 2026 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
+ ********************************************************************************/
+
+#pragma once
+
+#include <cstddef>
+#include <cstdint>
+
+void fixed_width(std::int32_t);
+void fixed_width(std::uint32_t);
+void size_vs_long(long);
+void size_vs_long(std::size_t);

cpp/libclang/integration_test/function_cases/overload_signedness_identity/run_test.rs

@@ -0,0 +1,19 @@
+// *******************************************************************************
+// Copyright (c) 2026 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
+// *******************************************************************************
+
+use test_framework::run_parser_case;
+
+#[test]
+fn test_overload_signedness_identity() {
+    run_parser_case();
+}