Make extern Swift functions public to prevent stripping in Release builds

SwiftRustIntegrationTestRunner/test-release-fails/.gitignore

@@ -0,0 +1,5 @@
+generated/*
+.build/*
+target/*
+Cargo.lock
+TestReleaseFails/*

SwiftRustIntegrationTestRunner/test-release-fails/Cargo.toml

@@ -0,0 +1,20 @@
+[package]
+name = "test-release-fails"
+version = "0.1.0"
+edition = "2021"
+publish = []
+
+build = "build.rs"
+
+[lib]
+crate-type = ["staticlib"]
+
+[build-dependencies]
+swift-bridge-build = { git = "https://github.com/chinedufn/swift-bridge.git", branch = "master" }
+
+[dependencies]
+swift-bridge = { git = "https://github.com/chinedufn/swift-bridge.git", branch = "master", features = [
+    "async",
+] }
+
+[workspace]

SwiftRustIntegrationTestRunner/test-release-fails/Package.swift

@@ -0,0 +1,26 @@
+// swift-tools-version:5.5.0
+import PackageDescription
+let package = Package(
+	name: "TestReleaseFails",
+	products: [
+		.library(
+			name: "TestReleaseFails",
+			targets: ["TestReleaseFails"]),
+        .executable(
+            name: "TestReleaseFailsRunner",
+            targets: ["TestReleaseFailsRunner"]),
+	],
+	dependencies: [],
+	targets: [
+		.binaryTarget(
+			name: "RustXcframework",
+			path: "RustXcframework.xcframework"
+		),
+		.target(
+			name: "TestReleaseFails",
+			dependencies: ["RustXcframework"]),
+        .executableTarget(
+            name: "TestReleaseFailsRunner",
+            dependencies: ["TestReleaseFails"])
+	]
+)	

SwiftRustIntegrationTestRunner/test-release-fails/README.md

@@ -0,0 +1,7 @@
+# Test Release Builds Fail
+
+This test is a reproduction case for when building for release,
+previously as `extern "Swift"` functions were `internal`
+the Swift compiler would strip these, as it would infer
+that they were dead code, even though these need to be accessible
+from the Rust side of the FFI.

SwiftRustIntegrationTestRunner/test-release-fails/SwiftExterns.swift

@@ -0,0 +1,5 @@
+import Foundation
+
+func add(lhs: Int32, rhs: Int32) -> Int32 {
+    lhs + rhs
+}

SwiftRustIntegrationTestRunner/test-release-fails/build.rs

@@ -0,0 +1,13 @@
+use std::path::PathBuf;
+
+fn main() {
+    let out_dir = PathBuf::from("./generated");
+
+    let bridges = vec!["src/lib.rs"];
+    for path in &bridges {
+        println!("cargo:rerun-if-changed={}", path);
+    }
+
+    swift_bridge_build::parse_bridges(bridges)
+        .write_all_concatenated(out_dir, env!("CARGO_PKG_NAME"));
+}

SwiftRustIntegrationTestRunner/test-release-fails/build.sh

@@ -0,0 +1,44 @@
+#!/bin/bash
+
+PACKAGE_NAME=test-release-fails
+LIBRARY_NAME=test_release_fails
+SWIFT_PACKAGE_NAME=TestReleaseFails
+EXECUTABLE_TARGET_NAME="$SWIFT_PACKAGE_NAME"Runner
+
+set -e
+
+THISDIR=$(dirname $0)
+cd $THISDIR
+
+echo "Building for macOS..."
+rustup target add x86_64-apple-darwin aarch64-apple-darwin
+cargo build --target x86_64-apple-darwin --release
+cargo build --target aarch64-apple-darwin --release
+mkdir -p ./target/universal-macos/release
+lipo \
+    ./target/aarch64-apple-darwin/release/lib$LIBRARY_NAME.a \
+    ./target/x86_64-apple-darwin/release/lib$LIBRARY_NAME.a -create -output \
+    ./target/universal-macos/release/lib$LIBRARY_NAME.a
+
+function create_package {
+  swift-bridge-cli create-package \
+        --bridges-dir ./generated \
+        --out-dir $SWIFT_PACKAGE_NAME \
+        --ios ./target/universal-macos/release/lib$LIBRARY_NAME.a \
+        --name $SWIFT_PACKAGE_NAME
+}
+
+function patch_package {
+    cp Package.swift $SWIFT_PACKAGE_NAME/Package.swift
+    mkdir -p $SWIFT_PACKAGE_NAME/Sources/$EXECUTABLE_TARGET_NAME
+    cp main.swift $SWIFT_PACKAGE_NAME/Sources/$EXECUTABLE_TARGET_NAME/main.swift
+    cp SwiftExterns.swift $SWIFT_PACKAGE_NAME/Sources/$SWIFT_PACKAGE_NAME/SwiftExterns.swift
+}
+
+echo "Creating Swift package..."
+create_package
+patch_package
+
+echo "Building for release..."
+cd $SWIFT_PACKAGE_NAME
+xcodebuild archive -scheme $EXECUTABLE_TARGET_NAME -archivePath ./build/$EXECUTABLE_TARGET_NAME.xcarchive -destination "platform=macOS"

SwiftRustIntegrationTestRunner/test-release-fails/main.swift

@@ -0,0 +1,4 @@
+import Foundation
+import TestReleaseFails
+
+call_swift_add()

SwiftRustIntegrationTestRunner/test-release-fails/src/lib.rs

@@ -0,0 +1,14 @@
+#[swift_bridge::bridge]
+mod ffi {
+    extern "Rust" {
+        fn call_swift_add();
+    }
+
+    extern "Swift" {
+        fn add(lhs: i32, rhs: i32) -> i32;
+    }
+}
+
+fn call_swift_add() {
+    assert!(ffi::add(1, 1) == 2);
+}

SwiftRustIntegrationTestRunner/test-release-succeeds/.gitignore

@@ -0,0 +1,5 @@
+generated/*
+.build/*
+target/*
+Cargo.lock
+TestReleaseSucceeds/*

SwiftRustIntegrationTestRunner/test-release-succeeds/Cargo.toml

@@ -0,0 +1,18 @@
+[package]
+name = "test-release-succeeds"
+version = "0.1.0"
+edition = "2021"
+publish = []
+
+build = "build.rs"
+
+[lib]
+crate-type = ["staticlib"]
+
+[build-dependencies]
+swift-bridge-build = { path = "../../crates/swift-bridge-build" }
+
+[dependencies]
+swift-bridge = { path = "../../", features = ["async"] }
+
+[workspace]

SwiftRustIntegrationTestRunner/test-release-succeeds/Package.swift

@@ -0,0 +1,26 @@
+// swift-tools-version:5.5.0
+import PackageDescription
+let package = Package(
+	name: "TestReleaseSucceeds",
+	products: [
+		.library(
+			name: "TestReleaseSucceeds",
+			targets: ["TestReleaseSucceeds"]),
+        .executable(
+            name: "TestReleaseSucceedsRunner",
+            targets: ["TestReleaseSucceedsRunner"]),
+	],
+	dependencies: [],
+	targets: [
+		.binaryTarget(
+			name: "RustXcframework",
+			path: "RustXcframework.xcframework"
+		),
+		.target(
+			name: "TestReleaseSucceeds",
+			dependencies: ["RustXcframework"]),
+        .executableTarget(
+            name: "TestReleaseSucceedsRunner",
+            dependencies: ["TestReleaseSucceeds"])
+	]
+)	

SwiftRustIntegrationTestRunner/test-release-succeeds/README.md

@@ -0,0 +1,7 @@
+# Test Release
+
+This test makes sure that when building for release,
+the Swift compiler doesn't strip functions that need to be accessible
+from the Rust side of the FFI.
+This test verifies that by making `extern "Swift"` functions `public`
+release builds now succeed.

SwiftRustIntegrationTestRunner/test-release-succeeds/SwiftExterns.swift

@@ -0,0 +1,5 @@
+import Foundation
+
+func add(lhs: Int32, rhs: Int32) -> Int32 {
+    lhs + rhs
+}

SwiftRustIntegrationTestRunner/test-release-succeeds/build.rs

@@ -0,0 +1,13 @@
+use std::path::PathBuf;
+
+fn main() {
+    let out_dir = PathBuf::from("./generated");
+
+    let bridges = vec!["src/lib.rs"];
+    for path in &bridges {
+        println!("cargo:rerun-if-changed={}", path);
+    }
+
+    swift_bridge_build::parse_bridges(bridges)
+        .write_all_concatenated(out_dir, env!("CARGO_PKG_NAME"));
+}

SwiftRustIntegrationTestRunner/test-release-succeeds/build.sh

@@ -0,0 +1,44 @@
+#!/bin/bash
+
+PACKAGE_NAME=test-release-succeeds
+LIBRARY_NAME=test_release_succeeds
+SWIFT_PACKAGE_NAME=TestReleaseSucceeds
+EXECUTABLE_TARGET_NAME="$SWIFT_PACKAGE_NAME"Runner
+
+set -e
+
+THISDIR=$(dirname $0)
+cd $THISDIR
+
+echo "Building for macOS..."
+rustup target add x86_64-apple-darwin aarch64-apple-darwin
+cargo build --target x86_64-apple-darwin --release
+cargo build --target aarch64-apple-darwin --release
+mkdir -p ./target/universal-macos/release
+lipo \
+    ./target/aarch64-apple-darwin/release/lib$LIBRARY_NAME.a \
+    ./target/x86_64-apple-darwin/release/lib$LIBRARY_NAME.a -create -output \
+    ./target/universal-macos/release/lib$LIBRARY_NAME.a
+
+function create_package {
+  swift-bridge-cli create-package \
+        --bridges-dir ./generated \
+        --out-dir $SWIFT_PACKAGE_NAME \
+        --ios ./target/universal-macos/release/lib$LIBRARY_NAME.a \
+        --name $SWIFT_PACKAGE_NAME
+}
+
+function patch_package {
+    cp Package.swift $SWIFT_PACKAGE_NAME/Package.swift
+    mkdir -p $SWIFT_PACKAGE_NAME/Sources/$EXECUTABLE_TARGET_NAME
+    cp main.swift $SWIFT_PACKAGE_NAME/Sources/$EXECUTABLE_TARGET_NAME/main.swift
+    cp SwiftExterns.swift $SWIFT_PACKAGE_NAME/Sources/$SWIFT_PACKAGE_NAME/SwiftExterns.swift
+}
+
+echo "Creating Swift package..."
+create_package
+patch_package
+
+echo "Building for release..."
+cd $SWIFT_PACKAGE_NAME
+xcodebuild archive -scheme $EXECUTABLE_TARGET_NAME -archivePath ./build/$EXECUTABLE_TARGET_NAME.xcarchive -destination "platform=macOS"

SwiftRustIntegrationTestRunner/test-release-succeeds/main.swift

@@ -0,0 +1,4 @@
+import Foundation
+import TestReleaseSucceeds
+
+call_swift_add()

SwiftRustIntegrationTestRunner/test-release-succeeds/src/lib.rs

@@ -0,0 +1,14 @@
+#[swift_bridge::bridge]
+mod ffi {
+    extern "Rust" {
+        fn call_swift_add();
+    }
+
+    extern "Swift" {
+        fn add(lhs: i32, rhs: i32) -> i32;
+    }
+}
+
+fn call_swift_add() {
+    assert!(ffi::add(1, 1) == 2);
+}

crates/swift-bridge-ir/src/codegen/codegen_tests.rs

@@ -52,6 +52,7 @@ mod string_codegen_tests;
 mod transparent_enum_codegen_tests;
 mod transparent_struct_codegen_tests;
 mod vec_codegen_tests;
+mod visibility_codegen_tests;
 
 struct CodegenTest {
     bridge_module: BridgeModule,

crates/swift-bridge-ir/src/codegen/codegen_tests/boxed_fnonce_codegen_tests.rs

@@ -55,7 +55,7 @@ mod test_swift_takes_no_args_no_return_callback {
         ExpectedSwiftCode::ContainsAfterTrim(
             r#"
 @_cdecl("__swift_bridge__$some_function")
-func __swift_bridge__some_function (_ callback: UnsafeMutableRawPointer) {
+public func __swift_bridge__some_function (_ callback: UnsafeMutableRawPointer) {
     { let cb0 = __private__RustFnOnceCallbackNoArgsNoRet(ptr: callback); let _ = some_function(callback: { cb0.call() }) }()
 }
 "#,
@@ -149,7 +149,7 @@ class __private__RustFnOnceCallback$some_function$param0 {
             "#,
             r#"
 @_cdecl("__swift_bridge__$some_function")
-func __swift_bridge__some_function (_ callback: UnsafeMutableRawPointer) {
+public func __swift_bridge__some_function (_ callback: UnsafeMutableRawPointer) {
     { let cb0 = __private__RustFnOnceCallback$some_function$param0(ptr: callback); let _ = some_function(callback: { arg0 in cb0.call(arg0) }) }()
 }
 "#,
@@ -248,7 +248,7 @@ class __private__RustFnOnceCallback$some_function$param0 {
             "#,
             r#"
 @_cdecl("__swift_bridge__$some_function")
-func __swift_bridge__some_function (_ callback: UnsafeMutableRawPointer) {
+public func __swift_bridge__some_function (_ callback: UnsafeMutableRawPointer) {
     { let cb0 = __private__RustFnOnceCallback$some_function$param0(ptr: callback); let _ = some_function(callback: { cb0.call() }) }()
 }
 "#,
@@ -351,7 +351,7 @@ class __private__RustFnOnceCallback$some_function$param0 {
             "#,
             r#"
 @_cdecl("__swift_bridge__$some_function")
-func __swift_bridge__some_function (_ callback: UnsafeMutableRawPointer) {
+public func __swift_bridge__some_function (_ callback: UnsafeMutableRawPointer) {
     { let cb0 = __private__RustFnOnceCallback$some_function$param0(ptr: callback); let _ = some_function(callback: { arg0 in cb0.call(arg0) }) }()
 }
 "#,
@@ -457,7 +457,7 @@ class __private__RustFnOnceCallback$some_function$param0 {
             "#,
             r#"
 @_cdecl("__swift_bridge__$some_function")
-func __swift_bridge__some_function (_ callback: UnsafeMutableRawPointer) {
+public func __swift_bridge__some_function (_ callback: UnsafeMutableRawPointer) {
     { let cb0 = __private__RustFnOnceCallback$some_function$param0(ptr: callback); let _ = some_function(callback: { cb0.call() }) }()
 }
 "#,
@@ -566,7 +566,7 @@ class __private__RustFnOnceCallback$some_function$param0 {
             "#,
             r#"
 @_cdecl("__swift_bridge__$some_function")
-func __swift_bridge__some_function (_ callback: UnsafeMutableRawPointer) {
+public func __swift_bridge__some_function (_ callback: UnsafeMutableRawPointer) {
     { let cb0 = __private__RustFnOnceCallback$some_function$param0(ptr: callback); let _ = some_function(callback: { arg0 in cb0.call(arg0) }) }()
 }
 "#,
@@ -690,7 +690,7 @@ class __private__RustFnOnceCallback$some_function$param1 {
             "#,
             r#"
 @_cdecl("__swift_bridge__$some_function")
-func __swift_bridge__some_function (_ arg0: UnsafeMutableRawPointer, _ arg1: UnsafeMutableRawPointer, _ arg2: UnsafeMutableRawPointer) {
+public func __swift_bridge__some_function (_ arg0: UnsafeMutableRawPointer, _ arg1: UnsafeMutableRawPointer, _ arg2: UnsafeMutableRawPointer) {
     { let cb0 = __private__RustFnOnceCallbackNoArgsNoRet(ptr: arg0); let cb1 = __private__RustFnOnceCallback$some_function$param1(ptr: arg1); let cb2 = __private__RustFnOnceCallbackNoArgsNoRet(ptr: arg2); let _ = some_function(arg0: { cb0.call() }, arg1: { arg0 in cb1.call(arg0) }, arg2: { cb2.call() }) }()
 }
 "#,
@@ -793,7 +793,7 @@ class __private__RustFnOnceCallback$some_function$param0 {
             "#,
             r#"
 @_cdecl("__swift_bridge__$some_function")
-func __swift_bridge__some_function (_ callback: UnsafeMutableRawPointer) {
+public func __swift_bridge__some_function (_ callback: UnsafeMutableRawPointer) {
     { let cb0 = __private__RustFnOnceCallback$some_function$param0(ptr: callback); let _ = some_function(callback: { arg0, arg1 in cb0.call(arg0, arg1) }) }()
 }
 "#,
@@ -865,7 +865,7 @@ mod test_swift_method_takes_no_args_no_return_callback {
         ExpectedSwiftCode::ContainsAfterTrim(
             r#"
 @_cdecl("__swift_bridge__$SomeType$some_method")
-func __swift_bridge__SomeType_some_method (_ this: UnsafeMutableRawPointer, _ callback: UnsafeMutableRawPointer) {
+public func __swift_bridge__SomeType_some_method (_ this: UnsafeMutableRawPointer, _ callback: UnsafeMutableRawPointer) {
     { let cb1 = __private__RustFnOnceCallbackNoArgsNoRet(ptr: callback); let _ = Unmanaged<SomeType>.fromOpaque(this).takeUnretainedValue().some_method(callback: { cb1.call() }) }()
 }
 "#,
@@ -967,7 +967,7 @@ class __private__RustFnOnceCallback$SomeType$some_method$param1 {
             "#,
             r#"
 @_cdecl("__swift_bridge__$SomeType$some_method")
-func __swift_bridge__SomeType_some_method (_ this: UnsafeMutableRawPointer, _ callback: UnsafeMutableRawPointer) {
+public func __swift_bridge__SomeType_some_method (_ this: UnsafeMutableRawPointer, _ callback: UnsafeMutableRawPointer) {
     { let cb1 = __private__RustFnOnceCallback$SomeType$some_method$param1(ptr: callback); let _ = Unmanaged<SomeType>.fromOpaque(this).takeUnretainedValue().some_method(callback: { arg0 in cb1.call(arg0) }) }()
 }
 "#,