make: add coverage target (#307)

Add coverage target for getting csv code-coverage output

Signed-off-by: Eric Ernst <eric_ernst@apple.com>

Makefile

@@ -22,6 +22,8 @@ SWIFT_CONFIGURATION = $(if $(filter-out false,$(WARNINGS_AS_ERRORS)),-Xswiftc -w
 SWIFT := "/usr/bin/swift"
 ROOT_DIR := $(shell git rev-parse --show-toplevel)
 BUILD_BIN_DIR = $(shell $(SWIFT) build -c $(BUILD_CONFIGURATION) --show-bin-path)
+COV_DATA_DIR = $(shell $(SWIFT) test --show-coverage-path | xargs dirname)
+COV_REPORT_FILE = $(ROOT_DIR)/code-coverage-report
 
 # Variables for libarchive integration
 LIBARCHIVE_UPSTREAM_REPO := https://github.com/libarchive/libarchive
@@ -90,6 +92,18 @@ test:
 	@echo Testing all test targets...
 	@$(SWIFT) test --enable-code-coverage $(SWIFT_CONFIGURATION)
 
+.PHONY: coverage
+coverage: test
+	@echo Generating code coverage report...
+	@xcrun llvm-cov show --compilation-dir=`pwd` \
+		-instr-profile=$(COV_DATA_DIR)/default.profdata \
+		--ignore-filename-regex=".build/" \
+		--ignore-filename-regex=".pb.swift" \
+		--ignore-filename-regex=".proto" \
+		--ignore-filename-regex=".grpc.swift" \
+		$(BUILD_BIN_DIR)/ContainerizationPackageTests.xctest/Contents/MacOS/ContainerizationPackageTests > $(COV_REPORT_FILE)
+	@echo Code coverage report generated: $(COV_REPORT_FILE)
+
 .PHONY: integration
 integration:
 ifeq (,$(wildcard bin/vmlinux))
@@ -159,5 +173,6 @@ clean:
 	@rm -rf bin/
 	@rm -rf _site/
 	@rm -rf _serve/
+	@rm -f $(COV_REPORT_FILE)
 	@$(SWIFT) package clean
 	@"$(MAKE)" -C vminitd clean