From a244a5f1ae5a652f421fa5e7f96048f8556d34af Mon Sep 17 00:00:00 2001
From: Baidyanath Kundu <kundubaidya99@gmail.com>
Date: Sat, 8 Jul 2023 14:08:09 +0530
Subject: [PATCH] Add test for GetFunctionUsingArgs

---
 include/clang/Interpreter/CppInterOp.h        | 13 ++++
 .../CppInterOp/FunctionReflectionTest.cpp     | 65 +++++++++++++++++++
 2 files changed, 78 insertions(+)

diff --git a/include/clang/Interpreter/CppInterOp.h b/include/clang/Interpreter/CppInterOp.h
index 12e16eecb..8cb3c6702 100644
--- a/include/clang/Interpreter/CppInterOp.h
+++ b/include/clang/Interpreter/CppInterOp.h
@@ -35,6 +35,14 @@ namespace Cpp {
   using TCppFuncAddr_t = void*;
   using TInterp_t = void*;
   using TCppObject_t = void*;
+
+  struct TemplateArgInfo {
+    TCppType_t m_Type;
+    const char* m_IntegralValue;
+    TemplateArgInfo(TCppScope_t type, const char* integral_value = nullptr)
+        : m_Type(type), m_IntegralValue(integral_value) {}
+  };
+
   /// A class modeling function calls for functions produced by the interpreter
   /// in compiled code. It provides an information if we are calling a standard
   /// function, constructor or destructor.
@@ -318,6 +326,11 @@ namespace Cpp {
   CPPINTEROP_API std::vector<TCppFunction_t>
   GetFunctionsUsingName(TCppScope_t scope, const std::string& name);
 
+  TCppFunction_t GetFunctionUsingArgs(
+      TCppScope_t scope, const std::string& name,
+      TCppType_t* arg_types, size_t arg_types_size,
+      TemplateArgInfo* template_args, size_t template_args_size);
+
   /// Gets the return type of the provided function.
   CPPINTEROP_API TCppType_t GetFunctionReturnType(TCppFunction_t func);
 
diff --git a/unittests/CppInterOp/FunctionReflectionTest.cpp b/unittests/CppInterOp/FunctionReflectionTest.cpp
index 5b76e1001..e53d36260 100644
--- a/unittests/CppInterOp/FunctionReflectionTest.cpp
+++ b/unittests/CppInterOp/FunctionReflectionTest.cpp
@@ -277,6 +277,71 @@ TEST(FunctionReflectionTest, GetClassDecls) {
   EXPECT_EQ(Cpp::GetName(methods[3])         , Cpp::GetName(SubDecls[8]));
 }
 
+TEST(FunctionReflectionTest, GetFunctionUsingArgs) {
+  std::vector<Decl*> Decls;
+  std::string code = R"(
+    // Overloaded functions
+    void f1(int a) {}
+    void f1() {}
+
+    // Templated functions
+    template <typename T>
+    void f2() { T t; }
+
+    // Templated functions deducible from args
+    template <typename T>
+    void f3(const T& t1, T* t2) {}
+
+    // Overloaded templated functions
+    template <typename T>
+    void f4() { T t; }
+    template <typename T1, typename T2>
+    void f4() { T1 t1; T2 t2; }
+    )";
+
+  auto get_function_name_using_args =
+      [&](Cpp::TCppScope_t scope, const std::string& name,
+          std::vector<Cpp::TCppType_t> arg_types,
+          std::vector<Cpp::TemplateArgInfo> template_args = {}){
+        Cpp::TCppFunction_t function = Cpp::GetFunctionUsingArgs(
+            scope, name,
+            arg_types.data(), arg_types.size(),
+            template_args.data(), template_args.size());
+
+        if (function == (void *) -1 || function == 0)
+          return std::string("");
+
+        return Cpp::GetFunctionSignature(function);
+  };
+
+  std::vector<Cpp::TCppType_t> arg_types;
+  std::vector<Cpp::TemplateArgInfo> template_args;
+
+  arg_types = {};
+  EXPECT_EQ(get_function_name_using_args(nullptr, "f1", arg_types), "void f1()");
+  arg_types = {Cpp::GetType("int")};
+  EXPECT_EQ(get_function_name_using_args(nullptr, "f1", arg_types), "void f1(int a)");
+
+  arg_types = {};
+  template_args = {{Cpp::GetType("int")}};
+  EXPECT_EQ(get_function_name_using_args(nullptr, "f2", arg_types, template_args), "void f2()");
+  arg_types = {};
+  template_args = {{Cpp::GetType("double")}};
+  EXPECT_EQ(get_function_name_using_args(nullptr, "f2", arg_types, template_args), "void f2()");
+
+  arg_types = {Cpp::GetType("const std::string &"), Cpp::GetType("std::string *")};
+  EXPECT_EQ(get_function_name_using_args(nullptr, "f3", arg_types), "void f3(const std::string &t1, std::string *t2)");
+  arg_types = {Cpp::GetType("const int &"), Cpp::GetType("int *")};
+  EXPECT_EQ(get_function_name_using_args(nullptr, "f3", arg_types), "void f3(const int &t1, int *t2)");
+
+  arg_types = {};
+  template_args = {{Cpp::GetType("double")}};
+  EXPECT_EQ(get_function_name_using_args(nullptr, "f4", arg_types, template_args), "void f4()");
+  arg_types = {};
+  template_args = {{Cpp::GetType("double")}, {Cpp::GetType("int")}};
+  EXPECT_EQ(get_function_name_using_args(nullptr, "f4", arg_types, template_args), "void f4()");
+}
+
 TEST(FunctionReflectionTest, GetFunctionReturnType) {
   std::vector<Decl*> Decls, SubDecls, TemplateSubDecls;
   std::string code = R"(