build: remove generated artifacts and unsafe scripts

Makefile

@@ -5,6 +5,8 @@ PKG_LIBS = $(shell pkg-config --libs dbus-1 wayland-client xkbcommon)
 CFLAGS = -Wall -Wextra -O2 -g $(PKG_CFLAGS)
 PROG = strans
 DOCKER_IMAGE = strans-build
+DOCKER_RUN = docker run --rm --user "$$(id -u):$$(id -g)" \
+	-v "$(CURDIR):/src" $(DOCKER_IMAGE)
 
 SRCS = $(wildcard *.c)
 OBJS = $(SRCS:.c=.o)
@@ -37,16 +39,20 @@ gtk:
 bench:
 	$(MAKE) -C bench/
 
-docker: Dockerfile
+docker-image: Dockerfile
 	docker build -t $(DOCKER_IMAGE) - < Dockerfile
-	docker run --rm --user "$$(id -u):$$(id -g)" \
-		-v "$(CURDIR):/src" $(DOCKER_IMAGE) \
-		sh -c 'make clean && make all'
 
-docker-check: docker
-	docker run --rm --user "$$(id -u):$$(id -g)" \
-		-e TESTARGS="$(TESTARGS)" -v "$(CURDIR):/src" \
-		$(DOCKER_IMAGE) make check
+docker-build:
+	$(DOCKER_RUN) make all
+
+docker-check:
+	$(DOCKER_RUN) make check TESTARGS="$(TESTARGS)"
+
+docker-bench:
+	$(DOCKER_RUN) make bench
+
+docker: docker-image
+	$(MAKE) docker-build
 
 check: verify-map test
 	$(MAKE) -C xim check
@@ -61,4 +67,5 @@ verify-map:
 	python3 -B tests/mkemoji_test.py
 	python3 -B tests/skk2ktrans_test.py
 
-.PHONY: all check test verify-map clean xim gtk bench docker docker-check
+.PHONY: all check test verify-map clean xim gtk bench docker docker-image \
+	docker-build docker-check docker-bench