[Cpp Parser] Support function param adjust and merge entity

cpp/libclang/integration_test/function_cases/parameter_adjustment_dedup/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 = "parameter_adjustment_dedup",
+    srcs = ["functions.cpp"],
+    hdrs = ["functions.hpp"],
+    visibility = ["//cpp/libclang:__subpackages__"],
+)
+
+cpp_parser_integration_test(
+    name = "test_parameter_adjustment_dedup",
+    expected_output = ["expected.json"],
+    target = ":parameter_adjustment_dedup",
+)

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

@@ -0,0 +1,203 @@
+{
+  "free_function_declarations": [
+    {
+      "name": "alias_fn",
+      "enclosing_namespace_id": null,
+      "return_type": "void",
+      "parameters": [
+        {
+          "name": "",
+          "param_type": "MyInt",
+          "is_variadic": false
+        }
+      ],
+      "template_parameters": null,
+      "source_location": {
+        "file": "cpp/libclang/integration_test/function_cases/parameter_adjustment_dedup/functions.hpp",
+        "line": 19
+      }
+    },
+    {
+      "name": "typedef_fn",
+      "enclosing_namespace_id": null,
+      "return_type": "void",
+      "parameters": [
+        {
+          "name": "",
+          "param_type": "OldInt",
+          "is_variadic": false
+        }
+      ],
+      "template_parameters": null,
+      "source_location": {
+        "file": "cpp/libclang/integration_test/function_cases/parameter_adjustment_dedup/functions.hpp",
+        "line": 20
+      }
+    },
+    {
+      "name": "arr_fn",
+      "enclosing_namespace_id": null,
+      "return_type": "void",
+      "parameters": [
+        {
+          "name": "",
+          "param_type": "int[5]",
+          "is_variadic": false
+        }
+      ],
+      "template_parameters": null,
+      "source_location": {
+        "file": "cpp/libclang/integration_test/function_cases/parameter_adjustment_dedup/functions.hpp",
+        "line": 21
+      }
+    },
+    {
+      "name": "incomplete_arr_fn",
+      "enclosing_namespace_id": null,
+      "return_type": "void",
+      "parameters": [
+        {
+          "name": "",
+          "param_type": "int[]",
+          "is_variadic": false
+        }
+      ],
+      "template_parameters": null,
+      "source_location": {
+        "file": "cpp/libclang/integration_test/function_cases/parameter_adjustment_dedup/functions.hpp",
+        "line": 22
+      }
+    },
+    {
+      "name": "callback_fn",
+      "enclosing_namespace_id": null,
+      "return_type": "void",
+      "parameters": [
+        {
+          "name": "callback",
+          "param_type": "void (int)",
+          "is_variadic": false
+        }
+      ],
+      "template_parameters": null,
+      "source_location": {
+        "file": "cpp/libclang/integration_test/function_cases/parameter_adjustment_dedup/functions.hpp",
+        "line": 23
+      }
+    },
+    {
+      "name": "callback_noexcept_identity",
+      "enclosing_namespace_id": null,
+      "return_type": "void",
+      "parameters": [
+        {
+          "name": "",
+          "param_type": "void (*)()",
+          "is_variadic": false
+        }
+      ],
+      "template_parameters": null,
+      "source_location": {
+        "file": "cpp/libclang/integration_test/function_cases/parameter_adjustment_dedup/functions.hpp",
+        "line": 24
+      }
+    },
+    {
+      "name": "callback_noexcept_identity",
+      "enclosing_namespace_id": null,
+      "return_type": "void",
+      "parameters": [
+        {
+          "name": "",
+          "param_type": "void (*)() noexcept",
+          "is_variadic": false
+        }
+      ],
+      "template_parameters": null,
+      "source_location": {
+        "file": "cpp/libclang/integration_test/function_cases/parameter_adjustment_dedup/functions.hpp",
+        "line": 25
+      }
+    }
+  ],
+  "functions": [
+    {
+      "id": {
+        "name": "alias_fn",
+        "scope": "Global"
+      },
+      "kind": "Free",
+      "return_type": {
+        "Builtin": "void"
+      },
+      "body": []
+    },
+    {
+      "id": {
+        "name": "typedef_fn",
+        "scope": "Global"
+      },
+      "kind": "Free",
+      "return_type": {
+        "Builtin": "void"
+      },
+      "body": []
+    },
+    {
+      "id": {
+        "name": "arr_fn",
+        "scope": "Global"
+      },
+      "kind": "Free",
+      "return_type": {
+        "Builtin": "void"
+      },
+      "body": []
+    },
+    {
+      "id": {
+        "name": "incomplete_arr_fn",
+        "scope": "Global"
+      },
+      "kind": "Free",
+      "return_type": {
+        "Builtin": "void"
+      },
+      "body": []
+    },
+    {
+      "id": {
+        "name": "callback_fn",
+        "scope": "Global"
+      },
+      "kind": "Free",
+      "return_type": {
+        "Builtin": "void"
+      },
+      "body": []
+    },
+    {
+      "id": {
+        "name": "callback_noexcept_identity",
+        "scope": "Global"
+      },
+      "kind": "Free",
+      "return_type": {
+        "Builtin": "void"
+      },
+      "body": []
+    },
+    {
+      "id": {
+        "name": "callback_noexcept_identity",
+        "scope": "Global"
+      },
+      "kind": "Free",
+      "return_type": {
+        "Builtin": "void"
+      },
+      "body": []
+    }
+  ],
+  "types": {}
+}

cpp/libclang/integration_test/function_cases/parameter_adjustment_dedup/functions.cpp

@@ -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
+ ********************************************************************************/
+
+#include "functions.hpp"
+
+void alias_fn(int value) {}
+void typedef_fn(int value) {}
+void arr_fn(int* values) {}
+void incomplete_arr_fn(int* values) {}
+void callback_fn(void (*callback)(int)) {}
+void callback_noexcept_identity(void (*)()) {}
+void callback_noexcept_identity(void (*)() noexcept) {}

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

@@ -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
+ ********************************************************************************/
+
+#pragma once
+
+using MyInt = int;
+typedef int OldInt;
+
+void alias_fn(MyInt);
+void typedef_fn(OldInt);
+void arr_fn(int[5]);
+void incomplete_arr_fn(int[]);
+void callback_fn(void callback(int));
+void callback_noexcept_identity(void (*)());
+void callback_noexcept_identity(void (*)() noexcept);

cpp/libclang/integration_test/function_cases/parameter_adjustment_dedup/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_parameter_adjustment_dedup() {
+    run_parser_case();
+}

cpp/libclang/src/semantics/src/resolved_type.rs

@@ -28,6 +28,8 @@ pub enum ResolvedType {
         return_type: Box<ResolvedType>,
         parameter_types: Vec<ResolvedType>,
         is_variadic: bool,
+        #[serde(default, skip_serializing_if = "is_false")]
+        is_noexcept: bool,
     },
     FunctionPointer(Box<ResolvedType>),
     FunctionReference(Box<ResolvedType>),
@@ -173,12 +175,18 @@ impl ResolvedType {
                 return_type,
                 parameter_types,
                 is_variadic,
+                is_noexcept,
             } => {
                 let mut parameters = parameter_types.iter().map(Self::render).collect::<Vec<_>>();
                 if *is_variadic {
                     parameters.push("...".to_string());
                 }
-                format!("{}({})", return_type.render(), parameters.join(", "))
+                let noexcept = if *is_noexcept { " noexcept" } else { "" };
+                format!(
+                    "{}({}){noexcept}",
+                    return_type.render(),
+                    parameters.join(", ")
+                )
             }
             Self::FunctionPointer(inner) => render_function_wrapper(inner, "*"),
             Self::FunctionReference(inner) => render_function_wrapper(inner, "&"),
@@ -198,11 +206,16 @@ impl ResolvedType {
     }
 }
 
+fn is_false(value: &bool) -> bool {
+    !value
+}
+
 fn render_function_wrapper(inner: &ResolvedType, marker: &str) -> String {
     if let ResolvedType::Function {
         return_type,
         parameter_types,
         is_variadic,
+        is_noexcept,
     } = inner
     {
         let mut parameters = parameter_types
@@ -212,8 +225,9 @@ fn render_function_wrapper(inner: &ResolvedType, marker: &str) -> String {
         if *is_variadic {
             parameters.push("...".to_string());
         }
+        let noexcept = if *is_noexcept { " noexcept" } else { "" };
         format!(
-            "{} ({marker})({})",
+            "{} ({marker})({}){noexcept}",
             return_type.render(),
             parameters.join(", ")
         )
@@ -335,6 +349,7 @@ mod tests {
             return_type: Box::new(ResolvedType::Builtin("void".to_string())),
             parameter_types: vec![ResolvedType::UserDefined("Engine".to_string())],
             is_variadic: false,
+            is_noexcept: false,
         };
         assert_eq!(
             ResolvedType::FunctionPointer(Box::new(function)).render_for_display(),

cpp/libclang/src/visitor/BUILD

@@ -16,6 +16,7 @@ rust_library(
     name = "visit_tu",
     srcs = [
         "src/callable_declaration.rs",
+        "src/clang_adapter/exception_specification.rs",
         "src/clang_adapter/mod.rs",
         "src/clang_adapter/scope.rs",
         "src/clang_adapter/source_filter.rs",