Migrate cpp_mstch_function properties to Whisker and delete class

Summary:
Migrate all 6 properties from `cpp_mstch_function` to the
`make_prototype_for_function` Whisker prototype, then delete the
`cpp_mstch_function` class entirely:

- `eb` → `event_based?` (renamed for clarity)
- `sync_returns_by_outparam?`
- `prefixed_name`
- `has_deprecated_header_client_methods`
- `virtual_client_methods?`
- `legacy_client_methods?`

The `interface()` mstch helper is replaced by
`context().get_function_parent()` in the Whisker properties.

Template changes:
- Renamed `function:eb` → `function:event_based?` across all cpp2 templates
- Converted mstch `{{#function:event_based?}}`/`{{^function:event_based?}}`
  conditional pairs to Whisker `{{#if}}`/`{{#else}}`/`{{/if}}` syntax
- Simplified nested negation conditions to `(not (or ...))` in
  `service_null.mustache` and `service_null_impl.mustache`

Reviewed By: praihan

Differential Revision: D95436828

fbshipit-source-id: d7e9ae825cffaacb3f53c69675dc17681f4cc5f9

Author: hchokshi

third-party/thrift/src/thrift/compiler/generate/t_mstch_cpp2_generator.cc

@@ -735,6 +735,57 @@ class t_mstch_cpp2_generator : public t_mstch_generator {
       return cpp2::is_stack_arguments(compiler_options(), function);
     });
 
+    def.property("event_based?", [this](const t_function& f) {
+      const t_interface* parent = context().get_function_parent(&f);
+      assert(parent != nullptr);
+      return f.get_unstructured_annotation("thread") == "eb" ||
+          f.has_structured_annotation(kCppProcessInEbThreadUri) ||
+          parent->has_unstructured_annotation("process_in_event_base") ||
+          parent->has_structured_annotation(kCppProcessInEbThreadUri);
+    });
+
+    def.property("sync_returns_by_outparam?", [](const t_function& f) {
+      return is_complex_return(f.return_type()->get_true_type()) &&
+          !f.interaction() && !f.sink_or_stream();
+    });
+
+    def.property("prefixed_name", [this](const t_function& f) {
+      const t_interface* parent = context().get_function_parent(&f);
+      assert(parent != nullptr);
+      const std::string& name = cpp2::get_name(&f);
+      return parent->is<t_interaction>()
+          ? fmt::format("{}_{}", parent->name(), name)
+          : name;
+    });
+
+    def.property(
+        "has_deprecated_header_client_methods", [this](const t_function& f) {
+          const t_interface* parent = context().get_function_parent(&f);
+          assert(parent != nullptr);
+          return f.has_structured_annotation(
+                     kCppGenerateDeprecatedHeaderClientMethodsUri) ||
+              f.has_unstructured_annotation(
+                  "cpp.generate_deprecated_header_client_methods") ||
+              parent->has_structured_annotation(
+                  kCppGenerateDeprecatedHeaderClientMethodsUri) ||
+              parent->has_unstructured_annotation(
+                  "cpp.generate_deprecated_header_client_methods");
+        });
+
+    def.property("virtual_client_methods?", [this](const t_function& f) {
+      const t_interface* parent = context().get_function_parent(&f);
+      assert(parent != nullptr);
+      return !generate_reduced_client(*parent) && !f.interaction() &&
+          !f.is_bidirectional_stream();
+    });
+
+    def.property("legacy_client_methods?", [this](const t_function& f) {
+      const t_interface* parent = context().get_function_parent(&f);
+      assert(parent != nullptr);
+      return !generate_reduced_client(*parent) && !f.interaction() &&
+          !f.is_bidirectional_stream();
+    });
+
     return std::move(def).make();
   }
 
@@ -1266,11 +1317,10 @@ class cpp_mstch_service : public mstch_service {
       const t_service* service,
       mstch_context& ctx,
       mstch_element_position pos,
-      source_manager& sm,
       const t_service* containing_service = nullptr,
       int32_t split_id = 0,
       int32_t split_count = 1)
-      : mstch_service(service, ctx, pos, containing_service), sm_(sm) {
+      : mstch_service(service, ctx, pos, containing_service) {
     register_methods(
         this,
         {
@@ -1324,7 +1374,6 @@ class cpp_mstch_service : public mstch_service {
   }
 
   std::vector<const t_function*> split_functions_;
-  source_manager& sm_;
 };
 
 class cpp_mstch_interaction : public cpp_mstch_service {
@@ -1335,75 +1384,8 @@ class cpp_mstch_interaction : public cpp_mstch_service {
       const t_interaction* interaction,
       mstch_context& ctx,
       mstch_element_position pos,
-      const t_service* containing_service,
-      source_manager& sm)
-      : cpp_mstch_service(interaction, ctx, pos, sm, containing_service) {}
-};
-
-class cpp_mstch_function : public mstch_function {
- public:
-  cpp_mstch_function(
-      const t_function* function,
-      mstch_context& ctx,
-      mstch_element_position pos,
-      std::shared_ptr<cpp2_generator_context> cpp_ctx)
-      : mstch_function(function, ctx, pos), cpp_context_(std::move(cpp_ctx)) {
-    register_methods(
-        this,
-        {
-            {"function:eb", &cpp_mstch_function::event_based},
-            {"function:sync_returns_by_outparam?",
-             &cpp_mstch_function::sync_returns_by_outparam},
-            {"function:prefixed_name", &cpp_mstch_function::prefixed_name},
-            {"function:has_deprecated_header_client_methods",
-             &cpp_mstch_function::has_deprecated_header_client_methods},
-            {"function:virtual_client_methods?",
-             &cpp_mstch_function::virtual_client_methods},
-            {"function:legacy_client_methods?",
-             &cpp_mstch_function::legacy_client_methods},
-        });
-  }
-  mstch::node event_based() {
-    return function_->get_unstructured_annotation("thread") == "eb" ||
-        function_->has_structured_annotation(kCppProcessInEbThreadUri) ||
-        interface().has_unstructured_annotation("process_in_event_base") ||
-        interface().has_structured_annotation(kCppProcessInEbThreadUri);
-  }
-  mstch::node sync_returns_by_outparam() {
-    return is_complex_return(function_->return_type()->get_true_type()) &&
-        !function_->interaction() && !function_->sink_or_stream();
-  }
-
-  mstch::node prefixed_name() {
-    const std::string& name = cpp2::get_name(function_);
-    return interface().is<t_interaction>()
-        ? fmt::format("{}_{}", interface().name(), name)
-        : name;
-  }
-
-  mstch::node has_deprecated_header_client_methods() {
-    return function_->has_structured_annotation(
-               kCppGenerateDeprecatedHeaderClientMethodsUri) ||
-        function_->has_unstructured_annotation(
-            "cpp.generate_deprecated_header_client_methods") ||
-        interface().has_structured_annotation(
-            kCppGenerateDeprecatedHeaderClientMethodsUri) ||
-        interface().has_unstructured_annotation(
-            "cpp.generate_deprecated_header_client_methods");
-  }
-
-  mstch::node virtual_client_methods() {
-    return !generate_reduced_client(interface()) && !function_->interaction() &&
-        !function_->is_bidirectional_stream();
-  }
-
-  mstch::node legacy_client_methods() {
-    return !generate_reduced_client(interface()) && !function_->interaction() &&
-        !function_->is_bidirectional_stream();
-  }
-
- private:
-  std::shared_ptr<cpp2_generator_context> cpp_context_;
+      const t_service* containing_service)
+      : cpp_mstch_service(interaction, ctx, pos, containing_service) {}
 };
 
 bool needs_op_encode(const t_type& type);
@@ -2471,9 +2453,8 @@ void t_mstch_cpp2_generator::generate_program() {
 
 void t_mstch_cpp2_generator::set_mstch_factories() {
   mstch_context_.add<cpp_mstch_program>(std::ref(source_mgr_));
-  mstch_context_.add<cpp_mstch_service>(std::ref(source_mgr_));
-  mstch_context_.add<cpp_mstch_interaction>(std::ref(source_mgr_));
-  mstch_context_.add<cpp_mstch_function>(cpp_context_);
+  mstch_context_.add<cpp_mstch_service>();
+  mstch_context_.add<cpp_mstch_interaction>();
   mstch_context_.add<cpp_mstch_type>(cpp_context_);
   mstch_context_.add<cpp_mstch_struct>(cpp_context_);
   mstch_context_.add<cpp_mstch_field>(cpp_context_);
@@ -2637,7 +2618,6 @@ void t_mstch_cpp2_generator::generate_out_of_line_service(
           service,
           mstch_context_,
           mstch_element_position(),
-          source_mgr_,
           nullptr,
           split_id,
           split_count);

third-party/thrift/src/thrift/compiler/generate/templates/cpp2/service_cpp/processmap.mustache

@@ -49,7 +49,7 @@ apache::thrift::ServiceRequestInfoMap {{service:cpp_name}}ServiceInfoHolder::sta
   apache::thrift::ServiceRequestInfoMap requestInfoMap = {
     {{#service:functions}}{{#function:return_type}}{{^function:starts_interaction?}}
   {"{{function:name}}",
-    { {{#function:eb}}true{{/function:eb}}{{^function:eb}}false{{/function:eb}},
+    { {{#if function:event_based?}}true{{#else}}false{{/if}},
      {{> types/function_kind}},
      "{{service:parent_service_name}}.{{> common/function_name}}",
      std::nullopt,
@@ -59,7 +59,7 @@ apache::thrift::ServiceRequestInfoMap {{service:cpp_name}}ServiceInfoHolder::sta
 {{/function:starts_interaction?}}{{/function:return_type}}{{/service:functions}}
 {{#service:interactions}}{{#service:functions}}{{#function:return_type}}
   {"{{service:name}}.{{function:name}}",
-    { {{#function:eb}}true{{/function:eb}}{{^function:eb}}false{{/function:eb}},
+    { {{#if function:event_based?}}true{{#else}}false{{/if}},
      {{> types/function_kind}},
      "{{service:parent_service_name}}.{{> common/function_name}}",
      "{{service:name}}",

third-party/thrift/src/thrift/compiler/generate/templates/cpp2/service_cpp/service_interface_impl.mustache

@@ -27,7 +27,7 @@
 //
 // Method '{{function:name}}'
 //
-{{^function:eb}}
+{{#if (not function:event_based?)}}
 
 {{> service_common/sync_function_return_type_server}} {{> service_common/service_class_name}}::{{function:cpp_name}}({{> service_common/sync_function_return_param_server}}{{> service_common/function_param_list_server_commented_out}}) {
   apache::thrift::detail::si::throw_app_exn_unimplemented("{{function:name}}");
@@ -229,8 +229,7 @@ determineInvocationType:
     callback->exception(std::current_exception());
   }
 }
-{{/function:eb}}
-{{#function:eb}}{{!Event base codegen}}
+{{#else}}
 {{#function:oneway?}}
 
 void {{> service_common/service_class_name}}::async_eb_{{function:cpp_name}}(
@@ -246,7 +245,7 @@ void {{> service_common/service_class_name}}::async_eb_{{function:cpp_name}}(
       apache::thrift::detail::si::create_app_exn_unimplemented("{{function:name}}"));
 }
 {{/function:oneway?}}
-{{/function:eb}}
+{{/if (not function:event_based?)}}
 //
 // End of Method '{{function:name}}'
 //

third-party/thrift/src/thrift/compiler/generate/templates/cpp2/service_cpp/service_null_impl.mustache

@@ -14,7 +14,7 @@
   See the License for the specific language governing permissions and
   limitations under the License.
 
-}}{{#service:functions}}{{#function:return_type}}{{^function:starts_interaction?}}{{^function:creates_interaction?}}{{^function:eb}}{{^function:stream?}}
+}}{{#service:functions}}{{#function:return_type}}{{#if (not (or function:starts_interaction? function:creates_interaction? function:event_based? function:stream?))}}
 {{> service_common/sync_function_return_type_server}} {{service:cpp_name}}SvNull::{{function:cpp_name}}({{> service_common/sync_function_return_param_server}}{{> service_common/function_param_list_server_commented_out}}) { {{!
 }}{{#type:resolves_to_complex_return?}} }{{/type:resolves_to_complex_return?}}
 {{^type:resolves_to_complex_return?}}
@@ -33,4 +33,4 @@
 }
 {{/type:resolves_to_complex_return?}}
 
-{{/function:stream?}}{{/function:eb}}{{/function:creates_interaction?}}{{/function:starts_interaction?}}{{/function:return_type}}{{/service:functions}}
+{{/if (not (or function:starts_interaction? function:creates_interaction? function:event_based? function:stream?))}}{{/function:return_type}}{{/service:functions}}

third-party/thrift/src/thrift/compiler/generate/templates/cpp2/service_h/service_interface_functions.mustache

@@ -19,7 +19,7 @@
 }}{{#let function_comma = (if function:params.fields? ", " null)}}
 {{#if (not function:starts_interaction?)}}
 {{#function:return_type}}
-{{^function:eb}}
+{{#if (not function:event_based?)}}
   virtual {{> service_common/sync_function_return_type_server}} sync_{{function:cpp_name}}({{> service_common/sync_function_return_param_server}}{{> service_common/function_param_list_server_commented_out}});
   [[deprecated("Use sync_{{function:cpp_name}} instead")]] virtual {{> service_common/sync_function_return_type_server}} {{function:cpp_name}}({{> service_common/sync_function_return_param_server}}{{> service_common/function_param_list_server_commented_out}});
 {{^service:interaction?}}
@@ -30,12 +30,12 @@
   virtual folly::coro::Task<{{> types/return_type_server}}> co_{{function:cpp_name}}({{> service_common/function_param_list_server}});
   virtual folly::coro::Task<{{> types/return_type_server}}> co_{{function:cpp_name}}(apache::thrift::RequestParams params{{function_comma}}{{> service_common/function_param_list_server}});
 #endif
-{{/function:eb}}
+{{/if (not function:event_based?)}}
 {{#function:oneway?}}
-  virtual void async_{{#function:eb}}eb{{/function:eb}}{{^function:eb}}tm{{/function:eb}}_{{function:cpp_name}}(apache::thrift::HandlerCallbackOneWay::Ptr callback{{function_comma}}{{> service_common/function_param_list_server}});
+  virtual void async_{{#if function:event_based?}}eb{{#else}}tm{{/if}}_{{function:cpp_name}}(apache::thrift::HandlerCallbackOneWay::Ptr callback{{function_comma}}{{> service_common/function_param_list_server}});
 {{/function:oneway?}}
 {{^function:oneway?}}
-  virtual void async_{{#function:eb}}eb{{/function:eb}}{{^function:eb}}tm{{/function:eb}}_{{function:cpp_name}}(apache::thrift::HandlerCallbackPtr<{{> types/return_type_server}}> callback{{function_comma}}{{> service_common/function_param_list_server}});
+  virtual void async_{{#if function:event_based?}}eb{{#else}}tm{{/if}}_{{function:cpp_name}}(apache::thrift::HandlerCallbackPtr<{{> types/return_type_server}}> callback{{function_comma}}{{> service_common/function_param_list_server}});
 {{/function:oneway?}}
 {{/function:return_type}}
 {{#else}}
@@ -47,7 +47,7 @@
   static {{service:qualified_name}}ServiceInfoHolder __fbthrift_serviceInfoHolder;
 {{/service:interaction?}}
 {{#service:functions}}
-{{^function:eb}}
+{{#if (not function:event_based?)}}
   std::atomic<apache::thrift::detail::si::InvocationType> __fbthrift_invocation_{{function:cpp_name}}{apache::thrift::detail::si::InvocationType::AsyncTm};
-{{/function:eb}}
+{{/if (not function:event_based?)}}
 {{/service:functions}}

third-party/thrift/src/thrift/compiler/generate/templates/cpp2/service_h/service_null.mustache

@@ -16,7 +16,7 @@
 
 }}class {{service:cpp_name}}SvNull : public ::apache::thrift::ServiceHandler<{{service:cpp_name}}>{{#service:extends}}, virtual public ::apache::thrift::ServiceHandler<::{{service:cpp_qualified_namespace}}::{{service:cpp_name}}>{{/service:extends}} {
  public:
-{{#service:functions}}{{#function:return_type}}{{^function:starts_interaction?}}{{^function:creates_interaction?}}{{^function:eb}}{{^function:stream?}}
+{{#service:functions}}{{#function:return_type}}{{#if (not (or function:starts_interaction? function:creates_interaction? function:event_based? function:stream?))}}
   {{> service_common/sync_function_return_type_server}} {{function:cpp_name}}({{> service_common/sync_function_return_param_server}}{{> service_common/function_param_list_server_commented_out}}) override;
-{{/function:stream?}}{{/function:eb}}{{/function:creates_interaction?}}{{/function:starts_interaction?}}{{/function:return_type}}{{/service:functions}}
+{{/if (not (or function:starts_interaction? function:creates_interaction? function:event_based? function:stream?))}}{{/function:return_type}}{{/service:functions}}
 };

third-party/thrift/src/thrift/compiler/generate/templates/cpp2/service_tcc/process_and_return.mustache

@@ -38,10 +38,10 @@ void {{service:parent_service_cpp_name}}AsyncProcessor::setUpAndProcess_{{functi
     folly::EventBase* eb,
     [[maybe_unused]] apache::thrift::concurrency::ThreadManager* tm) {
   if (!setUpRequestProcessing(
-          req, ctx, eb, {{#if function:eb}}nullptr{{#else}}tm{{/if}}, {{> types/function_kind}}, iface_{{#if service:interaction?}}, "{{interaction:name}}"{{/if}}{{#if function:creates_interaction?}}, "{{function:created_interaction.cpp_name}}", true{{/if}})) {
+          req, ctx, eb, {{#if function:event_based?}}nullptr{{#else}}tm{{/if}}, {{> types/function_kind}}, iface_{{#if service:interaction?}}, "{{interaction:name}}"{{/if}}{{#if function:creates_interaction?}}, "{{function:created_interaction.cpp_name}}", true{{/if}})) {
     return;
   }
-{{^function:eb}}
+{{#if (not function:event_based?)}}
   auto scope = iface_->getRequestExecutionScope(
       ctx, apache::thrift::concurrency::{{function:priority}});
   ctx->setRequestExecutionScope(std::move(scope));
@@ -55,7 +55,7 @@ void {{service:parent_service_cpp_name}}AsyncProcessor::setUpAndProcess_{{functi
       &{{service:parent_service_cpp_name}}AsyncProcessor::
           executeRequest_{{function:prefixed_name}}<ProtocolIn_, ProtocolOut_>,
       this);
-{{/function:eb}}{{#function:eb}}
+{{#else}}
   {{#if in_or_creates_interaction?}}
   processInThread(
       std::move(req),
@@ -86,7 +86,7 @@ void {{service:parent_service_cpp_name}}AsyncProcessor::setUpAndProcess_{{functi
       {}};
   executeRequest_{{function:prefixed_name}}<ProtocolIn_, ProtocolOut_>(std::move(serverRequest));
   {{/if in_or_creates_interaction?}}
-{{/function:eb}}
+{{/if (not function:event_based?)}}
 }
 
 template <typename ProtocolIn_, typename ProtocolOut_>
@@ -253,7 +253,7 @@ void {{service:parent_service_cpp_name}}AsyncProcessor::executeRequest_{{#servic
           throw_wrapped_{{#service:interaction?}}{{service:name}}_{{/service:interaction?}}{{function:cpp_name}}<ProtocolIn_, ProtocolOut_>,
           serverRequest.requestContext()->getProtoSeqId(),
           apache::thrift::detail::ServerRequestHelper::eventBase(serverRequest),
-          {{^function:eb}}apache::thrift::detail::ServerRequestHelper::executor(serverRequest){{/function:eb}}{{#function:eb}}nullptr{{/function:eb}},
+          {{#if function:event_based?}}nullptr{{#else}}apache::thrift::detail::ServerRequestHelper::executor(serverRequest){{/if}},
           serverRequest.requestContext(),
           requestPileNotification,
           concurrencyControllerNotification,
@@ -278,7 +278,7 @@ void {{service:parent_service_cpp_name}}AsyncProcessor::executeRequest_{{#servic
         return;
       }
 {{/if service:self.interaction?}}
-      ifacePtr->{{#function:eb}}async_eb{{/function:eb}}{{^function:eb}}async_tm{{/function:eb}}_{{function:cpp_name}}(std::move(cb){{> service_tcc/get_args_ref}});
+      ifacePtr->{{#if function:event_based?}}async_eb{{#else}}async_tm{{/if}}_{{function:cpp_name}}(std::move(cb){{> service_tcc/get_args_ref}});
     };
   };
 #if FOLLY_HAS_COROUTINES