Add code coverage report generation

.gitignore

@@ -1,2 +1,3 @@
 bin/
 obj/
+coverage/

.vscode/tasks.json

@@ -74,7 +74,24 @@
         {
             "label": "exec_unit_test",
             "type":"shell",
-            "command": "make exec_unit_test",
+            "command": "make exec_unit_test -j1",
+            "problemMatcher": {
+                "base": "$gcc",
+                "owner": "gcc",
+                "fileLocation": [
+                    "relative",
+                    "${workspaceFolder}"
+                ]
+            },
+            "group": {
+                "kind": "build",
+                "isDefault": true
+            }
+        },
+        {
+            "label": "coverage",
+            "type":"shell",
+            "command": "make coverage -j1",
             "problemMatcher": {
                 "base": "$gcc",
                 "owner": "gcc",

Makefile

@@ -5,26 +5,32 @@ TARGET_FILE ?= ftdi_gpio
 CC = $(CROSS_COMPILE)gcc
 CPP = $(CROSS_COMPILE)cpp
 CHECK = cppcheck
+LCOV = lcov
+GENHTML = genhtml
 
 SRC_DIR = src
 OBJ_DIR = obj
 BIN_DIR = bin
+COVERAGE_DIR = coverage
 UNIT_TEST_SRC_DIR = test/unit
 UNIT_TEST_OBJ_DIR = $(OBJ_DIR)/$(UNIT_TEST_SRC_DIR)
 
 INCLUDES := inc
 INCLUDES += /usr/include/libftdi1
 
-ifneq "$(findstring $(MAKECMDGOALS), build_unit_test exec_unit_test)" ""
+ifneq "$(findstring $(MAKECMDGOALS), build_unit_test exec_unit_test coverage)" ""
 INCLUDES += test/inc
+
+C_FLAGS += --coverage
+L_FLAGS += --coverage
+
 else
 LIBS := ftdi1
 endif
 
-LD_FLAGS :=
-C_FLAGS := -O0 -g -Wall -Wextra -Werror
-CPP_FLAGS := $(addprefix -I, $(INCLUDES))
-CHECK_CLAGS := --enable=all --template=gcc --error-exitcode=1 --suppress=missingIncludeSystem
+C_FLAGS += -O0 -g -Wall -Wextra -Werror
+CPP_FLAGS += $(addprefix -I, $(INCLUDES))
+CHECK_FLAGS = --enable=all --template=gcc --error-exitcode=1 --suppress=missingIncludeSystem
 
 C_SRCS = $(wildcard $(SRC_DIR)/*.c)
 C_OBJS = $(patsubst $(SRC_DIR)%,$(OBJ_DIR)%,$(patsubst %.c,%.o,$(C_SRCS)))
@@ -42,6 +48,25 @@ THIS_MAKEFILE := $(lastword $(MAKEFILE_LIST))
 .PHONY: all
 all: $(TARGET)
 
+.PHONY: coverage
+coverage: _cov_genhtml
+	$(eval COVERAGE:=$(shell grep 'lines' .coverage.tmp | egrep -o '[0-9]+.[0-9]+%'))
+	@echo
+	@echo Line coverage: $(COVERAGE)
+	@echo
+	@rm -f .coverage.tmp
+
+.PHONY: _cov_lcov
+_cov_lcov: exec_unit_test
+	@rm -f $(UNIT_TEST_OBJ_DIR)/*.gcda
+	@rm -f $(UNIT_TEST_OBJ_DIR)/*.gcno
+	@mkdir -p $(COVERAGE_DIR)
+	$(LCOV) -c -d $(OBJ_DIR) -o $(COVERAGE_DIR)/coverage.info
+
+.PHONY: _cov_genhtml
+_cov_genhtml: _cov_lcov
+	$(GENHTML) -o $(COVERAGE_DIR)/html $(COVERAGE_DIR)/coverage.info > .coverage.tmp
+
 .PHONY: unit_test
 build_unit_test: $(UNIT_TEST_TARGET)
 
@@ -51,7 +76,7 @@ exec_unit_test: $(UNIT_TEST_TARGET)
 
 .PHONY: check
 check: $(C_SRCS)
-	$(CHECK) $(CPP_FLAGS) $(CHECK_CLAGS) $(C_SRCS)
+	$(CHECK) $(CPP_FLAGS) $(CHECK_FLAGS) $(C_SRCS)
 
 $(UNIT_TEST_TARGET): $(UNIT_TEST_OBJS) $(THIS_MAKEFILE)
 	@mkdir -p $(BIN_DIR)/$(UNIT_TEST_SRC_DIR)
@@ -81,8 +106,10 @@ $(UNIT_TEST_OBJ_DIR)/%.o: $(UNIT_TEST_SRC_DIR)/%.c $(UNIT_TEST_OBJ_DIR)/%.d
 
 .PHONY: clean
 clean:
-	rm -rf $(OBJS) $(patsubst %.o,%.d,$(OBJS)) $(TARGET)
-	rm -rf $(UNIT_TEST_OBJS) $(patsubst %.o,%.d,$(UNIT_TEST_OBJS)) $(UNIT_TEST_TARGET)
+	rm -f $(OBJS) $(patsubst %.o,%.d,$(OBJS)) $(TARGET)
+	rm -f $(UNIT_TEST_OBJS) $(patsubst %.o,%.d,$(UNIT_TEST_OBJS)) $(UNIT_TEST_TARGET)
+	rm -f $(OBJ_DIR)/*.gcda $(OBJ_DIR)/*.gcno
+	rm -fr $(COVERAGE_DIR)
 
 ifneq ($(MAKECMDGOALS),clean)
 -include $(patsubst %.o,%.d,$(OBJS))