Add option to select feature flags for codegen

frb_codegen/src/binary/commands.rs

@@ -172,6 +172,10 @@ pub(crate) struct GenerateCommandArgsPrimary {
     /// Dump all internal data. Same as `--dump` with all possible choices chosen.
     #[arg(long)]
     pub dump_all: bool,
+
+    /// List of cargo feature flags to enable when generating
+    #[arg(long)]
+    pub rust_features: Option<Vec<String>>,
 }
 
 #[derive(Debug, Args)]

frb_codegen/src/binary/commands_parser.rs

@@ -60,6 +60,7 @@ fn compute_codegen_config_from_naive_command_args(args: GenerateCommandArgsPrima
         stop_on_error: positive_bool_arg(args.stop_on_error),
         dump: args.dump,
         dump_all: positive_bool_arg(args.dump_all),
+        rust_features: args.rust_features,
     }
 }
 

frb_codegen/src/library/codegen/config/config.rs

@@ -38,6 +38,7 @@ pub struct Config {
     pub stop_on_error: Option<bool>,
     pub dump: Option<Vec<ConfigDumpContent>>,
     pub dump_all: Option<bool>,
+    pub rust_features: Option<Vec<String>>,
 }
 
 #[derive(Debug, Serialize, Deserialize, Default)]
@@ -93,4 +94,5 @@ generate_merge!(
     stop_on_error,
     dump,
     dump_all,
+    rust_features,
 );

frb_codegen/src/library/codegen/config/internal_config_parser/mod.rs

@@ -108,6 +108,7 @@ impl InternalConfig {
                     rust_crate_dir: rust_crate_dir.clone(),
                     rust_input_namespace_pack: rust_input_namespace_pack.clone(),
                     third_party_crate_names,
+                    rust_features: config.rust_features.clone(),
                 },
                 mir: ParserMirInternalConfig {
                     rust_input_namespace_pack: rust_input_namespace_pack.clone(),

frb_codegen/src/library/codegen/parser/hir/internal_config.rs

@@ -8,4 +8,5 @@ pub(crate) struct ParserHirInternalConfig {
     pub rust_input_namespace_pack: RustInputNamespacePack,
     pub rust_crate_dir: PathBuf,
     pub third_party_crate_names: Vec<CrateName>,
+    pub rust_features: Option<Vec<String>>,
 }

frb_codegen/src/library/codegen/parser/hir/raw/mod.rs

@@ -22,6 +22,7 @@ pub(crate) fn parse(
                 &config.rust_crate_dir,
                 (!crate_name.is_self_crate()).then_some(crate_name),
                 dumper,
+                config.rust_features.as_deref(),
             )?,
         })
     })

frb_codegen/src/library/codegen/parser/mod.rs

@@ -174,6 +174,7 @@ mod tests {
                 rust_input_namespace_pack: rust_input_namespace_pack.clone(),
                 rust_crate_dir: rust_crate_dir.clone(),
                 third_party_crate_names: vec![],
+                rust_features: None,
             },
             mir: ParserMirInternalConfig {
                 rust_input_namespace_pack: rust_input_namespace_pack.clone(),

frb_codegen/src/library/commands/cargo_expand/mod.rs

@@ -13,9 +13,10 @@ pub(crate) fn run_cargo_expand(
     rust_crate_dir: &Path,
     interest_crate_name: Option<&CrateName>,
     dumper: &Dumper,
+    features: Option<&[String]>,
 ) -> Result<syn::File> {
     if can_execute_real(rust_crate_dir)? {
-        real::run(rust_crate_dir, interest_crate_name, dumper)
+        real::run(rust_crate_dir, interest_crate_name, dumper, features)
     } else {
         pseudo::run(rust_crate_dir, interest_crate_name)
     }

frb_codegen/src/library/commands/cargo_expand/real.rs

@@ -10,27 +10,31 @@ use log::{debug, info};
 use regex::{Captures, Regex};
 use std::borrow::Cow;
 use std::env;
-use std::path::Path;
+use std::path::{Path, PathBuf};
+use std::str::FromStr;
 
 pub(super) fn run(
     rust_crate_dir: &Path,
     interest_crate_name: Option<&CrateName>,
     dumper: &Dumper,
+    features: Option<&[String]>,
 ) -> Result<syn::File> {
-    let text = run_with_frb_aware(rust_crate_dir, interest_crate_name)?;
+    let text = run_with_frb_aware(rust_crate_dir, interest_crate_name, features)?;
     (dumper.with_content(ConfigDumpContent::Source)).dump_str("cargo_expand.rs", &text)?;
     Ok(syn::parse_file(&text)?)
 }
 
 fn run_with_frb_aware(
     rust_crate_dir: &Path,
     interest_crate_name: Option<&CrateName>,
+    features: Option<&[String]>,
 ) -> Result<String> {
     Ok(decode_macro_frb_encoded_comments(&run_raw(
         rust_crate_dir,
         interest_crate_name,
         "--cfg frb_expand",
         true,
+        features,
     )?)
     .into_owned())
 }
@@ -55,6 +59,7 @@ fn run_raw(
     interest_crate_name: Option<&CrateName>,
     extra_rustflags: &str,
     allow_auto_install: bool,
+    features: Option<&[String]>,
 ) -> Result<String> {
     // let _pb = simple_progress("Run cargo-expand".to_owned(), 1);
     debug!("Running cargo expand in '{rust_crate_dir:?}'");
@@ -65,13 +70,22 @@ fn run_raw(
         vec![]
     };
 
+    let args_features: Vec<PathBuf> = features
+        .unwrap_or_default()
+        .iter()
+        .flat_map(|feature| vec!["--features", feature])
+        .map(PathBuf::from_str)
+        .try_collect()?;
+
     let args = command_args!(
         "expand",
         "--lib",
         "--theme=none",
         "--ugly",
         *args_choosing_crate,
+        *args_features
     );
+
     let extra_env = [(
         "RUSTFLAGS".to_owned(),
         env::var("RUSTFLAGS").map(|x| x + " ").unwrap_or_default() + extra_rustflags,
@@ -88,7 +102,13 @@ fn run_raw(
         if stderr.contains("no such command: `expand`") && allow_auto_install {
             info!("Cargo expand is not installed. Automatically install and re-run.");
             install_cargo_expand()?;
-            return run_raw(rust_crate_dir, interest_crate_name, extra_rustflags, false);
+            return run_raw(
+                rust_crate_dir,
+                interest_crate_name,
+                extra_rustflags,
+                false,
+                features,
+            );
         }
         // This will stop the whole generator and tell the users, so we do not care about testing it
         // frb-coverage:ignore-start

frb_codegen/test_fixtures/library/codegen/config/internal_config_parser/single_rust_input/expect_output.json

@@ -1,13 +1,9 @@
 {
   "controller": {
-    "exclude_paths": [
-      "{the-working-directory}/src/frb_generated.rs"
-    ],
+    "exclude_paths": ["{the-working-directory}/src/frb_generated.rs"],
     "max_count": null,
     "watch": false,
-    "watching_paths": [
-      "{the-working-directory}/src"
-    ]
+    "watching_paths": ["{the-working-directory}/src"]
   },
   "dumper": {
     "dump_contents": [],
@@ -91,12 +87,11 @@
     "hir": {
       "rust_crate_dir": "{the-working-directory}",
       "rust_input_namespace_pack": {
-        "rust_input_namespace_prefixes": [
-          "crate::api"
-        ],
+        "rust_input_namespace_prefixes": ["crate::api"],
         "rust_output_path_namespace": "crate::frb_generated"
       },
-      "third_party_crate_names": []
+      "third_party_crate_names": [],
+      "rust_features": null
     },
     "mir": {
       "default_dart_async": true,
@@ -108,9 +103,7 @@
         "rust2dart": "Pde"
       },
       "rust_input_namespace_pack": {
-        "rust_input_namespace_prefixes": [
-          "crate::api"
-        ],
+        "rust_input_namespace_prefixes": ["crate::api"],
         "rust_output_path_namespace": "crate::frb_generated"
       },
       "stop_on_error": false,
@@ -134,4 +127,4 @@
     "deps_check": true,
     "needs_ffigen": false
   }
-}
+}

frb_codegen/test_fixtures/library/codegen/config/internal_config_parser/wildcard_rust_input/expect_output.json

@@ -1,13 +1,9 @@
 {
   "controller": {
-    "exclude_paths": [
-      "{the-working-directory}/src/frb_generated.rs"
-    ],
+    "exclude_paths": ["{the-working-directory}/src/frb_generated.rs"],
     "max_count": null,
     "watch": false,
-    "watching_paths": [
-      "{the-working-directory}/src"
-    ]
+    "watching_paths": ["{the-working-directory}/src"]
   },
   "dumper": {
     "dump_contents": [],
@@ -91,12 +87,11 @@
     "hir": {
       "rust_crate_dir": "{the-working-directory}",
       "rust_input_namespace_pack": {
-        "rust_input_namespace_prefixes": [
-          "crate::api"
-        ],
+        "rust_input_namespace_prefixes": ["crate::api"],
         "rust_output_path_namespace": "crate::frb_generated"
       },
-      "third_party_crate_names": []
+      "third_party_crate_names": [],
+      "rust_features": null
     },
     "mir": {
       "default_dart_async": true,
@@ -108,9 +103,7 @@
         "rust2dart": "Pde"
       },
       "rust_input_namespace_pack": {
-        "rust_input_namespace_prefixes": [
-          "crate::api"
-        ],
+        "rust_input_namespace_prefixes": ["crate::api"],
         "rust_output_path_namespace": "crate::frb_generated"
       },
       "stop_on_error": false,
@@ -134,4 +127,4 @@
     "deps_check": true,
     "needs_ffigen": false
   }
-}
+}

frb_dart/lib/src/cli/build_web/executor.dart

@@ -36,17 +36,20 @@ class BuildWebArgs {
   final String? dartCompileJsEntrypoint;
 
   /// {@macro flutter_rust_bridge.cli}
-  const BuildWebArgs({
-    required this.output,
-    required this.release,
-    required this.verbose,
-    required this.rustCrateDir,
-    required this.cargoBuildArgs,
-    required this.wasmBindgenArgs,
-    required this.wasmPackRustupToolchain,
-    required this.wasmPackRustflags,
-    required this.dartCompileJsEntrypoint,
-  });
+  final List<String> features;
+
+  /// {@macro flutter_rust_bridge.cli}
+  const BuildWebArgs(
+      {required this.output,
+      required this.release,
+      required this.verbose,
+      required this.rustCrateDir,
+      required this.cargoBuildArgs,
+      required this.wasmBindgenArgs,
+      required this.wasmPackRustupToolchain,
+      required this.wasmPackRustflags,
+      required this.dartCompileJsEntrypoint,
+      this.features = const []});
 }
 
 extension on BuildWebArgs {

frb_example/pure_dart/build.dart

@@ -1,3 +1,5 @@
 import 'package:flutter_rust_bridge_utils/flutter_rust_bridge_utils.dart';
 
-void main(List<String> args) async => simpleBuild(args);
+void main(List<String> args) async => simpleBuild(args,
+    // This is solely used for testing
+    features: ['internal_feature_for_testing']);

frb_example/pure_dart/flutter_rust_bridge.yaml

@@ -19,3 +19,5 @@ enable_lifetime: true
 dump_all: true
 # only for development of flutter_rust_bridge, not for normal users (use local dependency)
 local: true
+rust_features:
+  - internal_feature_for_testing

frb_example/pure_dart/frb_generated.h

@@ -4296,6 +4296,8 @@ void frbgen_frb_example_pure_dart_wire__crate__api__misc_no_twin_example_a__func
 
 void frbgen_frb_example_pure_dart_wire__crate__api__misc_no_twin_example_a__function_with_custom_name_twin_normal(int64_t port_);
 
+void frbgen_frb_example_pure_dart_wire__crate__api__misc_no_twin_example_a__getFeatureTest(int64_t port_);
+
 void frbgen_frb_example_pure_dart_wire__crate__api__misc_no_twin_example_a__item_container_solution_two_twin_normal_create_twin_normal(int64_t port_);
 
 void frbgen_frb_example_pure_dart_wire__crate__api__misc_no_twin_example_a__item_container_solution_two_twin_normal_get_item_contents_twin_normal(int64_t port_,
@@ -16406,6 +16408,7 @@ static int64_t dummy_method_to_enforce_bundling(void) {
     dummy_var ^= ((int64_t) (void*) frbgen_frb_example_pure_dart_wire__crate__api__misc_no_twin_example_a__StructWithSimpleSetterTwinNormal_simple_setter);
     dummy_var ^= ((int64_t) (void*) frbgen_frb_example_pure_dart_wire__crate__api__misc_no_twin_example_a__function_with_arg_type_name_override);
     dummy_var ^= ((int64_t) (void*) frbgen_frb_example_pure_dart_wire__crate__api__misc_no_twin_example_a__function_with_custom_name_twin_normal);
+    dummy_var ^= ((int64_t) (void*) frbgen_frb_example_pure_dart_wire__crate__api__misc_no_twin_example_a__getFeatureTest);
     dummy_var ^= ((int64_t) (void*) frbgen_frb_example_pure_dart_wire__crate__api__misc_no_twin_example_a__item_container_solution_two_twin_normal_create_twin_normal);
     dummy_var ^= ((int64_t) (void*) frbgen_frb_example_pure_dart_wire__crate__api__misc_no_twin_example_a__item_container_solution_two_twin_normal_get_item_contents_twin_normal);
     dummy_var ^= ((int64_t) (void*) frbgen_frb_example_pure_dart_wire__crate__api__misc_no_twin_example_a__my_struct_with_sync_sync);

frb_example/pure_dart/lib/src/rust/api/misc_no_twin_example_a.dart

@@ -25,6 +25,9 @@ Future<void> functionWithArgTypeNameOverride(
     RustLib.instance.api
         .crateApiMiscNoTwinExampleAFunctionWithArgTypeNameOverride(a: a);
 
+Future<String> getFeatureTest() =>
+    RustLib.instance.api.crateApiMiscNoTwinExampleAGetFeatureTest();
+
 // Rust type: RustOpaqueNom<flutter_rust_bridge::for_generated::RustAutoOpaqueInner<Box < dyn Any + Send + Sync + 'static >>>
 abstract class BoxAnyMyDartTypeRename implements RustOpaqueInterface {}
 

frb_example/pure_dart/lib/src/rust/frb_generated.dart

@@ -339,7 +339,7 @@ class RustLib extends BaseEntrypoint<RustLibApi, RustLibApiImpl, RustLibWire> {
   String get codegenVersion => '2.4.0';
 
   @override
-  int get rustContentHash => -952199392;
+  int get rustContentHash => 2008667945;
 
   static const kDefaultExternalLibraryLoaderConfig =
       ExternalLibraryLoaderConfig(
@@ -1251,6 +1251,8 @@ abstract class RustLibApi extends BaseApi {
 
   Future<void> crateApiMiscNoTwinExampleAFunctionWithCustomNameTwinNormal();
 
+  Future<String> crateApiMiscNoTwinExampleAGetFeatureTest();
+
   Future<ItemContainerSolutionTwoTwinNormal>
       crateApiMiscNoTwinExampleAItemContainerSolutionTwoTwinNormalCreateTwinNormal();
 
@@ -20300,6 +20302,29 @@ class RustLibApiImpl extends RustLibApiImplPlatform implements RustLibApi {
             argNames: [],
           );
 
+  @override
+  Future<String> crateApiMiscNoTwinExampleAGetFeatureTest() {
+    return handler.executeNormal(NormalTask(
+      callFfi: (port_) {
+        return wire
+            .wire__crate__api__misc_no_twin_example_a__getFeatureTest(port_);
+      },
+      codec: DcoCodec(
+        decodeSuccessData: dco_decode_String,
+        decodeErrorData: null,
+      ),
+      constMeta: kCrateApiMiscNoTwinExampleAGetFeatureTestConstMeta,
+      argValues: [],
+      apiImpl: this,
+    ));
+  }
+
+  TaskConstMeta get kCrateApiMiscNoTwinExampleAGetFeatureTestConstMeta =>
+      const TaskConstMeta(
+        debugName: "getFeatureTest",
+        argNames: [],
+      );
+
   @override
   Future<ItemContainerSolutionTwoTwinNormal>
       crateApiMiscNoTwinExampleAItemContainerSolutionTwoTwinNormalCreateTwinNormal() {

frb_example/pure_dart/lib/src/rust/frb_generated.io.dart

@@ -48300,6 +48300,21 @@ class RustLibWire implements BaseWire {
       _wire__crate__api__misc_no_twin_example_a__function_with_custom_name_twin_normalPtr
           .asFunction<void Function(int)>();
 
+  void wire__crate__api__misc_no_twin_example_a__getFeatureTest(
+    int port_,
+  ) {
+    return _wire__crate__api__misc_no_twin_example_a__getFeatureTest(
+      port_,
+    );
+  }
+
+  late final _wire__crate__api__misc_no_twin_example_a__getFeatureTestPtr =
+      _lookup<ffi.NativeFunction<ffi.Void Function(ffi.Int64)>>(
+          'frbgen_frb_example_pure_dart_wire__crate__api__misc_no_twin_example_a__getFeatureTest');
+  late final _wire__crate__api__misc_no_twin_example_a__getFeatureTest =
+      _wire__crate__api__misc_no_twin_example_a__getFeatureTestPtr
+          .asFunction<void Function(int)>();
+
   void
       wire__crate__api__misc_no_twin_example_a__item_container_solution_two_twin_normal_create_twin_normal(
     int port_,