Makefile.base: use thin static archives.

Makefile.base

@@ -67,10 +67,12 @@ $(BINDIR)/$(MODULE)/:
 
 $(BINDIR)/$(MODULE).a $(OBJ): | $(BINDIR)/$(MODULE)/
 
+relpath = $(shell realpath --relative-to=$(abspath .) $(1))
+
 $(BINDIR)/$(MODULE).a: $(OBJ) | $(DIRS:%=ALL--%)
 	@# Recreate archive to cleanup deleted/non selected source files objects
 	$(Q)$(RM) $@
-	$(Q)$(AR) $(ARFLAGS) $@ $^
+	$(Q)$(AR) $(ARFLAGS) $(foreach f,$@ $^,$(call relpath,$f))
 
 CXXFLAGS = $(filter-out $(CXXUWFLAGS), $(CFLAGS)) $(CXXEXFLAGS)
 CCASFLAGS = $(filter-out $(CCASUWFLAGS), $(CFLAGS)) $(CCASEXFLAGS)

Makefile.include

@@ -498,6 +498,49 @@ print-size: $(ELFFILE)
 
 endif # BUILD_IN_DOCKER
 
+# Rules to check the correctness of thin archives.
+
+relpath = $(shell realpath --relative-to=$(abspath .) $(1))
+
+# Each ARCHECK file contains all the absolute paths found inside the archive.
+BASELIB_ARCHECKS = $(patsubst %.a,%.a-check,$(filter %.a,$(BASELIBS)))
+
+# For each a file, print the absolute paths found inside it
+# If "ar t" is called with an absolute path it will print an abs path regardless
+# of how the archive is internally
+# In case of a malformed archive, ar prints to stderr (and sets an error code).
+# Doing `2>&1` is hacky, the correct thing would be to get the exit code.
+# The `| %.a` is necessary to be able to check file produced in docker.
+%.a-check: %.a
+	$(Q)$(AR) t $(call relpath,$<) 2>&1 | grep '^/' | '$(LAZYSPONGE)' $(LAZYSPONGE_FLAGS) '$@'
+
+# There's no point on keeping files whose content is later copied to another file
+.INTERMEDIATE: $(BASELIB_ARCHECKS)
+
+ARCHIVE_CHECK = $(BINDIR)/$(APPLICATION).archive-check
+
+$(ARCHIVE_CHECK): $(BASELIB_ARCHECKS)
+	$(Q)cat $^ | '$(LAZYSPONGE)' $(LAZYSPONGE_FLAGS) '$@'
+
+# Rule to check if thin archives are correctly produced, that is, with a correct
+# relative path.
+ifeq ($(BUILD_IN_DOCKER),1)
+archive-check: ..in-docker-container
+else
+archive-check: $(ARCHIVE_CHECK) FORCE
+	@if [ -s '$<' ] ; then \
+		$(COLOR_ECHO) '$(COLOR_RED)Found the following absolute paths in archives' ;\
+		cat '$<';\
+		$(COLOR_ECHO) '$(COLOR_RESET)' ;\
+		exit 1;\
+	elif [ -f '$<' ] ; then \
+		$(COLOR_ECHO) '$(COLOR_GREEN)Archives correctly formed$(COLOR_RESET)' ;\
+	else \
+		$(COLOR_ECHO) '$(COLOR_RED)Unexpected error (file not found)$(COLOR_RESET)' ;\
+		exit 1;\
+	fi
+endif # BUILD_IN_DOCKER
+
 # Check given command is available in the path
 #   check_cmd 'command' 'description'
 define check_cmd

makefiles/cflags.inc.mk

@@ -65,5 +65,5 @@ CFLAGS += $(filter-out $(OPTIONAL_CFLAGS_BLACKLIST),$(OPTIONAL_CFLAGS))
 # Default ARFLAGS for platforms which do not specify it.
 # Note: make by default provides ARFLAGS=rv which we want to override
 ifeq ($(origin ARFLAGS),default)
-  ARFLAGS = rcs
+  ARFLAGS = rcTs
 endif

makefiles/docker.inc.mk

@@ -9,6 +9,7 @@ export DOCKER_MAKECMDGOALS_POSSIBLE = \
   scan-build \
   scan-build-analyze \
   tests-% \
+  archive-check \
   #
 export DOCKER_MAKECMDGOALS = $(filter $(DOCKER_MAKECMDGOALS_POSSIBLE),$(MAKECMDGOALS))
 

sys/arduino/Makefile.include

@@ -2,7 +2,7 @@
 
 # Define application sketches module, it will be generated into $(BINDIR)
 SKETCH_MODULE     ?= arduino_sketches
-SKETCH_MODULE_DIR ?= $(BINDIR)/$(SKETCH_MODULE)
+SKETCH_MODULE_DIR ?= $(BINDIR)/$(SKETCH_MODULE)_src
 SKETCHES           = $(wildcard $(APPDIR)/*.sketch)
 include $(RIOTBASE)/sys/arduino/sketches.inc.mk
 

sys/arduino/sketches.inc.mk

@@ -19,7 +19,8 @@ SKETCH_GENERATED_FILES = $(SKETCH_MODULE_DIR)/Makefile $(SKETCH_MODULE_DIR)/$(SK
 # Building the module files
 #   Do not use $^ in receipes as Makefile is also a prerequisite
 $(SKETCH_MODULE_DIR)/Makefile: $(SKETCH_MODULE_DIR)/$(SKETCH_CPP)
-	$(Q)echo 'SRCXX = $(SKETCH_CPP)'               > $@
+	$(Q)echo 'MODULE = $(SKETCH_MODULE)'           > $@
+	$(Q)echo 'SRCXX = $(SKETCH_CPP)'              >> $@
 	$(Q)echo 'include $$(RIOTBASE)/Makefile.base' >> $@
 $(SKETCH_MODULE_DIR)/$(SKETCH_CPP): $(SKETCHES_ALL)
 	@mkdir -p $(@D)