Code format uncrustify

.Makefile.mk

@@ -8,6 +8,14 @@ VARIABLE+=ESPPORT
 HELP_ESPPORT=which device to flash/monitor
 export ESPPORT
 
+VARIABLE+=FORMAT
+HELP_FORMAT=patterns of files to format
+ifndef FORMAT
+FORMAT += **/*.h
+FORMAT += **/*.c
+FORMAT += !**/build/**/*
+endif
+
 ### internal variables ###
 
 # assume /etc/passwd holds right shell of user
@@ -31,6 +39,8 @@ TEMPLATEPATH=../.Makefile.template
 ### default target ###
 DEFAULT += help
 
+UNCRUSTIFY_CFG = ./.uncrustify.cfg
+
 ### menuconfig targets ###
 
 .PHONY: menuconfig
@@ -107,6 +117,28 @@ CHECK += check-monitor
 HELP_check-monitor = check env if monitor is possible
 check-monitor: | check-docker check-dev
 
+### code format
+
+.PHONY: format
+TARGET += format
+HELP_format = formats code with uncrustify
+format: | check-docker
+	@make --no-print-directory -C $(DOCKERDIR) uncrustify \
+	EXEC="git ls-files -ico $(foreach PATTERN,$(FORMAT),-x $(PATTERN)) \
+	      | xargs -I % uncrustify -c $(UNCRUSTIFY_CFG) --replace --no-backup %"
+
+.PHONY: check-format
+TARGET += check-format
+HELP_check-format = check if formatting code with uncrustify is necessary
+check-format: | check-docker
+	@make --no-print-directory -C $(DOCKERDIR) uncrustify \
+	EXEC="git ls-files -ico $(foreach PATTERN,$(FORMAT),-x $(PATTERN)) \
+	      | xargs -I % sh -c \"uncrustify -c $(UNCRUSTIFY_CFG) -f % \
+	                          | git diff --exit-code \
+	                                     --no-index \
+	                                     --color \
+	                                     % - \""
+
 ### vscode ###
 
 .PHONY: vscode

.github/workflows/formatting.yml

@@ -0,0 +1,15 @@
+name: Check code format
+
+on: [push, pull_request]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v1
+    - name: build uncrustify image
+      run: make -C docker uncrustify-image
+    - name: check code format
+      run: make -C lifesensor DOCKEROPTS=--tty=false check-format