Fix handling of member function pointers in the API snapshot (#56069)

scripts/cxx-api/parser/builders.py

@@ -249,7 +249,7 @@ def get_variable_member(
         if initializer_type == InitializerType.BRACE:
             is_brace_initializer = True
 
-    return VariableMember(
+    member = VariableMember(
         variable_name,
         variable_type,
         visibility,
@@ -263,6 +263,10 @@ def get_variable_member(
         is_brace_initializer,
     )
 
+    member.add_template(get_template_params(member_def))
+
+    return member
+
 
 def get_doxygen_params(
     function_def: compound.MemberdefType,
@@ -313,6 +317,21 @@ def get_doxygen_params(
             else:
                 param_type += param_array
 
+        # Handle pointer-to-member-function types where the name must be
+        # embedded inside the declarator group.  Doxygen gives:
+        #   type = "void(ns::*)() const", name = "asFoo"
+        # We need to produce:
+        #   "void(ns::*asFoo)() const"
+        if param_name:
+            m = re.search(r"\([^)]*::\*\)", param_type)
+            if m:
+                # Insert name before the closing ')' of the ptr-to-member group
+                insert_pos = m.end() - 1
+                param_type = (
+                    param_type[:insert_pos] + param_name + param_type[insert_pos:]
+                )
+                param_name = None
+
         qualifiers, core_type = extract_qualifiers(param_type)
         arguments.append((qualifiers, core_type, param_name, param_default))
 

scripts/cxx-api/parser/member.py

@@ -162,6 +162,9 @@ def to_string(
 
         result = " " * indent
 
+        if self.template_list is not None:
+            result += self.template_list.to_string() + "\n" + " " * indent
+
         if not hide_visibility:
             result += self.visibility + " "
 

scripts/cxx-api/tests/snapshots/should_handle_pointer_to_member_function_param/snapshot.api

@@ -0,0 +1,6 @@
+struct folly::dynamic {
+}
+
+
+template <typename R, typename... T>
+R test::jsArg(const folly::dynamic& arg, R(folly::dynamic::*asFoo)() const, const T &... desc);

scripts/cxx-api/tests/snapshots/should_handle_pointer_to_member_function_param/test.h

@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#pragma once
+
+namespace folly {
+
+struct dynamic {};
+
+} // namespace folly
+
+namespace test {
+
+template <typename R, typename... T>
+R jsArg(const folly::dynamic &arg, R (folly::dynamic::*asFoo)() const, const T &...desc);
+
+} // namespace test

scripts/cxx-api/tests/snapshots/should_handle_template_variable/snapshot.api

@@ -0,0 +1,7 @@
+template <typename T>
+const test::Strct<T> test::Strct<T>::VALUE;
+
+template <typename T>
+struct test::Strct {
+  public static const test::Strct<T> VALUE;
+}

scripts/cxx-api/tests/snapshots/should_handle_template_variable/test.h

@@ -0,0 +1,20 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#pragma once
+
+namespace test {
+
+template <typename T>
+struct Strct {
+  static const Strct<T> VALUE;
+};
+
+template <typename T>
+const Strct<T> Strct<T>::VALUE = {};
+
+} // namespace test

scripts/cxx-api/tests/snapshots/should_qualify_variable_template_specialization/snapshot.api

@@ -1,5 +1,7 @@
-constexpr T test::default_value;
 constexpr test::MyType test::default_value<test::MyType>;
+template <typename T>
+constexpr T test::default_value;
+template <typename T>
 T* test::null_ptr;
 test::MyType* test::null_ptr<test::MyType>;