chore(apple): allow generating UniFFI bindings on Linux (#10600)

To generate the UniFFI bindings, we don't actually need to be on an
Apple device. To make cross-platform development a bit easier, we
extract the binding generation step into the Makefile.

swift/apple/Makefile

@@ -4,8 +4,14 @@ PLATFORM?=macOS
 ARCH=$(shell uname -m)
 CONFIGURATION?=Debug
 
-# Path to rust target directory (relative to this Makefile)
-RUST_TARGET_DIR=$(abspath ../../rust/target)
+# Paths
+RUST_DIR=$(abspath ../../rust)
+RUST_TARGET_DIR=$(RUST_DIR)/target
+CLIENT_FFI_DIR=$(RUST_DIR)/client-ffi
+GENERATED_DIR=$(abspath FirezoneNetworkExtension/Connlib/Generated)
+
+# Find all Rust source files in client-ffi
+CLIENT_FFI_SOURCES=$(shell find $(CLIENT_FFI_DIR)/src -name "*.rs" 2>/dev/null)
 
 # Set consistent environment to prevent Rust rebuilds
 # This must match the Xcode project setting
@@ -23,16 +29,38 @@ GIT_SHA=$(shell git rev-parse HEAD 2>/dev/null || echo "unknown")
 
 # Default target: build and install
 .PHONY: all
-all: build install
+all: uniffi-bindings build install
+
+# Generate UniFFI bindings from Rust source
+# This works on any platform (not just macOS)
+$(GENERATED_DIR)/connlib.swift $(GENERATED_DIR)/connlibFFI.h: $(CLIENT_FFI_SOURCES) $(CLIENT_FFI_DIR)/Cargo.toml
+	@echo "Generating UniFFI bindings..."
+	@mkdir -p $(GENERATED_DIR)
+	@cd $(RUST_DIR) && \
+		(test -f $(RUST_TARGET_DIR)/debug/libconnlib.a || cargo build -p client-ffi) && \
+		cargo run -p uniffi-bindgen -- generate \
+			--library $(RUST_TARGET_DIR)/debug/libconnlib.a \
+			--language swift \
+			--out-dir $(GENERATED_DIR)
+	@rm -f $(GENERATED_DIR)/*.modulemap
+	@if [ -f "$(GENERATED_DIR)/connlib.swift" ]; then \
+		sed -i.bak '/#if canImport(connlibFFI)/,/#endif/s/^/\/\/ /' $(GENERATED_DIR)/connlib.swift; \
+		rm -f $(GENERATED_DIR)/connlib.swift.bak; \
+	fi
+	@echo "✅ UniFFI bindings generated"
+
+.PHONY: uniffi-bindings
+uniffi-bindings: $(GENERATED_DIR)/connlib.swift $(GENERATED_DIR)/connlibFFI.h
 
 # Info for sourcekit-lsp (LSP server for other IDEs)
+.PHONY: lsp
 lsp:
 	@xcode-build-server config \
         -project Firezone.xcodeproj \
         -scheme Firezone
 
 .PHONY: build
-build:
+build: $(GENERATED_DIR)/connlib.swift $(GENERATED_DIR)/connlibFFI.h
 	@echo "Building Xcode project for ${PLATFORM}, ${ARCH}"
 	@echo "Git SHA: ${GIT_SHA}"
 	@xcodebuild build \
@@ -70,7 +98,7 @@ clean:
 		-sdk macosx
 	@echo "Cleaning Rust build artifacts"
 	@cd ../../rust/client-ffi && cargo clean
-	@echo "Removing Generated bindings"
+	@echo "Removing generated bindings"
 	@rm -rf FirezoneNetworkExtension/Connlib/Generated
 
 .PHONY: format

swift/apple/build-rust.sh

@@ -7,7 +7,6 @@ trap 'echo "ERROR: Build script failed at line $LINENO" >&2' ERR
 # Get script directory
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
 RUST_DIR="$SCRIPT_DIR/../../rust"
-GENERATED_DIR="$SCRIPT_DIR/FirezoneNetworkExtension/Connlib/Generated"
 
 # Sanitize the environment to prevent Xcode's shenanigans from leaking
 # into our highly evolved Rust-based build system.
@@ -136,9 +135,9 @@ for target in "${TARGETS[@]}"; do
     fi
 done
 
-# Step 1: Build Rust library
+# Build Rust library
 echo ""
-echo "Step 1/3: Building Rust library..."
+echo "Building Rust library..."
 
 # Build target list for cargo command
 target_list=""
@@ -158,47 +157,14 @@ for target in "${TARGETS[@]}"; do
     fi
 done
 
-# Step 2: Generate UniFFI bindings
+# Generate UniFFI bindings
 echo ""
-echo "Step 2/3: Generating UniFFI bindings..."
-mkdir -p "$GENERATED_DIR"
-
-# Use the first target's library for generating bindings (they're the same for all architectures)
-FIRST_TARGET="${TARGETS[0]}"
-LIBRARY_PATH="$CARGO_TARGET_DIR/$FIRST_TARGET/$BUILD_DIR"
-
-cargo run -p uniffi-bindgen -- generate \
-    --library "$LIBRARY_PATH/libconnlib.a" \
-    --language swift \
-    --out-dir "$GENERATED_DIR"
-
-# Remove module maps (we use bridging header instead)
-rm -f "$GENERATED_DIR"/*.modulemap
-
-# Fix imports in generated Swift file to use bridging header
-if [ -f "$GENERATED_DIR/connlib.swift" ]; then
-    # Comment out the #if canImport(connlibFFI) block
-    sed -i.bak '/#if canImport(connlibFFI)/,/#endif/s/^/\/\/ /' "$GENERATED_DIR/connlib.swift"
-    rm -f "$GENERATED_DIR/connlib.swift.bak"
-fi
-
-# Step 3: Verify generated files
-echo ""
-echo "Step 3/3: Verifying generated files..."
-if [ ! -f "$GENERATED_DIR/connlib.swift" ]; then
-    echo "ERROR: Generated Swift file not found" >&2
-    exit 1
-fi
-
-if [ ! -f "$GENERATED_DIR/connlibFFI.h" ]; then
-    echo "ERROR: Generated header file not found" >&2
-    exit 1
-fi
+echo "Generating UniFFI bindings..."
+cd "$SCRIPT_DIR"
+make uniffi-bindings
 
 echo ""
-echo "✅ Build completed successfully!"
-echo "   Swift bindings: $GENERATED_DIR/connlib.swift"
-echo "   C header: $GENERATED_DIR/connlibFFI.h"
+echo "✅ Rust library build completed successfully!"
 echo "   Built libraries:"
 for target in "${TARGETS[@]}"; do
     echo "     - $CARGO_TARGET_DIR/$target/$BUILD_DIR/libconnlib.a"