makefiles: avoid building archives when compiling

Makefile.base

@@ -17,9 +17,9 @@ DIRS := $(sort $(abspath $(DIRS)))
 _MOD := $(shell basename $(CURDIR))
 MODULE ?= $(_MOD)
 
-.PHONY: all clean $(DIRS:%=ALL--%) $(DIRS:%=CLEAN--%)
+.PHONY: all clean $(DIRS:%=ALL--%) $(DIRS:%=CLEAN--%) $(MODULE).module
 
-all: $(BINDIR)/$(MODULE).a ..nothing
+all: $(MODULE).module ..nothing
 
 ..nothing:
 	@:
@@ -89,14 +89,12 @@ include $(RIOTMAKE)/tools/fixdep.inc.mk
 $(BINDIR)/$(MODULE)/:
 	$(Q)mkdir -p $@
 
-$(BINDIR)/$(MODULE).a $(OBJ): | $(BINDIR)/$(MODULE)/
+# only create the module folder when it's going to hold objects
+ifneq (,$(strip $(OBJ)))
+  $(MODULE).module $(OBJ): | $(BINDIR)/$(MODULE)/
+endif
 
-# Build the archive from the output directory to create relative thin archives
-# This allows having them valid in and outside of docker
-$(BINDIR)/$(MODULE).a: $(OBJ) | $(DIRS:%=ALL--%)
-	@# Recreate archive to cleanup deleted/non selected source files objects
-	$(Q)$(RM) $@
-	$(Q)cd $(@D) && $(AR) $(ARFLAGS) $(@F) $(subst $(@D)/,,$^)
+$(MODULE).module: $(OBJ) | $(DIRS:%=ALL--%)
 
 CXXFLAGS = $(filter-out $(CXXUWFLAGS), $(CFLAGS)) $(CXXEXFLAGS)
 CCASFLAGS = $(filter-out $(CCASUWFLAGS), $(CFLAGS)) $(CCASEXFLAGS)

Makefile.include

@@ -426,12 +426,6 @@ CFLAGS += -DBOARD_$(BOARDDEF)=\"$(BOARD)\" -DRIOT_BOARD=BOARD_$(BOARDDEF)
 CFLAGS += -DCPU_$(CPUDEF)=\"$(CPU)\" -DRIOT_CPU=CPU_$(CPUDEF)
 CFLAGS += -DMCU_$(MCUDEF)=\"$(MCU)\" -DRIOT_MCU=MCU_$(MCUDEF)
 
-# OSX fails to create empty archives. Provide a wrapper to catch that error.
-ifneq (0, $(shell mkdir -p $(BINDIR); $(AR) rc $(BINDIR)/empty-archive.a 2> /dev/null; \
-            echo $$?; rm -f $(BINDIR)/empty-archive.a 2>&1 > /dev/null))
-	AR := $(RIOTBASE)/dist/ar-wrapper $(AR)
-endif
-
 # Feature test default CFLAGS and LINKFLAGS for the set compiled.
 include $(RIOTMAKE)/cflags.inc.mk
 
@@ -452,7 +446,7 @@ endif
 APPLICATION_MODULE ?= application_$(APPLICATION)
 
 # the binaries to link
-BASELIBS += $(BINDIR)/$(APPLICATION_MODULE).a
+BASELIBS += $(APPLICATION_MODULE).module
 BASELIBS += $(APPDEPS)
 
 
@@ -567,11 +561,14 @@ BUILDDEPS += $(APPDEPS)
 _BASELIBS_VALUE_BEFORE_USAGE := $(BASELIBS)
 
 # Linker rule
+# Only use --start-group when archives are defined
+ARCHIVES_GROUP = $(if $(ARCHIVES),$(LINKFLAGPREFIX)--start-group $(ARCHIVES) -lm $(LINKFLAGPREFIX)--end-group, -lm)
+
 $(ELFFILE): FORCE
 ifeq ($(BUILDOSXNATIVE),1)
-  _LINK = $(if $(CPPMIX),$(LINKXX),$(LINK)) $(UNDEF) $$(find $(BASELIBS) -size +8c) $(LINKFLAGS) $(LINKFLAGPREFIX)-no_pie
+  _LINK = $(if $(CPPMIX),$(LINKXX),$(LINK)) $$(find $(BASELIBS:%.module=$(BINDIR)/%/*.o) 2> /dev/null) $(ARCHIVES_GROUP) $(LINKFLAGS) $(LINKFLAGPREFIX)-no_pie
 else
-  _LINK = $(if $(CPPMIX),$(LINKXX),$(LINK)) $(UNDEF) $(LINKFLAGPREFIX)--start-group $(BASELIBS) -lm $(LINKFLAGPREFIX)--end-group $(LINKFLAGS) $(LINKFLAGPREFIX)-Map=$(BINDIR)/$(APPLICATION).map
+  _LINK = $(if $(CPPMIX),$(LINKXX),$(LINK)) $$(find $(BASELIBS:%.module=$(BINDIR)/%/*.o) 2> /dev/null) $(ARCHIVES_GROUP) $(LINKFLAGS) $(LINKFLAGPREFIX)-Map=$(BINDIR)/$(APPLICATION).map
 endif # BUILDOSXNATIVE
 
 ifeq ($(BUILD_IN_DOCKER),1)
@@ -580,20 +577,22 @@ else
 ifeq (,$(RIOTNOLINK))
 link: ..compiler-check ..build-message $(BUILD_FILES) print-size
 else
-link: ..compiler-check ..build-message $(BASELIBS)
+link: ..compiler-check ..build-message $(BASELIBS) $(ARCHIVES)
 endif # RIOTNOLINK
 
-$(ELFFILE): $(BASELIBS)
+$(ELFFILE): $(BASELIBS) $(ARCHIVES)
 	$(Q)$(_LINK) -o $@
 
-$(BINDIR)/$(APPLICATION_MODULE).a: pkg-build $(BUILDDEPS)
+.PHONY: $(APPLICATION_MODULE).module
+
+$(APPLICATION_MODULE).module: pkg-build $(BUILDDEPS)
 	$(Q)DIRS="$(DIRS)" APPLICATION_BLOBS="$(BLOBS)" \
 	  "$(MAKE)" -C $(APPDIR) -f $(RIOTMAKE)/application.inc.mk
-$(BINDIR)/$(APPLICATION_MODULE).a: FORCE
+$(APPLICATION_MODULE).module: FORCE
 
 # Other modules are built by application.inc.mk and packages building
-_SUBMAKE_LIBS = $(filter-out $(BINDIR)/$(APPLICATION_MODULE).a $(APPDEPS), $(BASELIBS))
-$(_SUBMAKE_LIBS): $(BINDIR)/$(APPLICATION_MODULE).a pkg-build
+_SUBMAKE_LIBS = $(filter-out $(APPLICATION_MODULE).module $(APPDEPS), $(BASELIBS) $(ARCHIVES))
+$(_SUBMAKE_LIBS): $(APPLICATION_MODULE).module pkg-build
 
 # 'print-size' triggers a rebuild. Use 'info-buildsize' if you do not need to rebuild.
 print-size: $(ELFFILE)
@@ -607,50 +606,6 @@ print-size: $(ELFFILE)
 
 endif # BUILD_IN_DOCKER
 
-# Rules to check the correctness of thin archives.
-
-# OS independant relpath as 'realpath --relative-to' is not supported on OSx
-relpath = $(shell python3 -c 'import pathlib; print(pathlib.Path("$1").relative_to("$(CURDIR)"))')
-
-# 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)$(COLOR_RESET)' ;\
-		exit 1;\
-	fi
-endif # BUILD_IN_DOCKER
-
 # Check given command is available in the path
 #   check_cmd 'command' 'description'
 define check_cmd
@@ -680,7 +635,7 @@ endif
 	@$(COLOR_ECHO)
 
 # The `clean` needs to be serialized before everything else.
-all $(BASELIBS) $(BUILDDEPS) ..in-docker-container: | $(CLEAN)
+all $(BASELIBS) $(ARCHIVES) $(BUILDDEPS) ..in-docker-container: | $(CLEAN)
 
 .PHONY: pkg-prepare pkg-build pkg-build-%
 pkg-prepare:

boards/native/Makefile.include

@@ -169,5 +169,3 @@ eval-gprof:
 
 eval-cachegrind:
 	$(CGANNOTATE) $(shell ls -rt cachegrind.out* | tail -1)
-
-UNDEF += $(BINDIR)/cpu/startup.o

cpu/arm7_common/Makefile.include

@@ -17,5 +17,3 @@ ASFLAGS     += $(CFLAGS_CPU) $(CFLAGS_DBG)
 LINKFLAGS   += -T$(RIOTCPU)/$(CPU)/ldscripts/$(CPU).ld
 LINKFLAGS   += $(CFLAGS_CPU) $(CFLAGS_DBG) $(CFLAGS_OPT) -static -lgcc -nostartfiles
 LINKFLAGS   += -Wl,--gc-sections
-
-UNDEF += $(BINDIR)/cpu/startup.o

cpu/cc26x0/Makefile.include

@@ -1,7 +1,5 @@
 CPU_VARIANT = x0
 
-VECTORS_O = $(BINDIR)/cc26xx_cc13xx/vectors.o
-
 ROM_START_ADDR ?= 0x00000000
 RAM_START_ADDR ?= 0x20000000
 

cpu/cc26x2_cc13x2/Makefile.include

@@ -1,7 +1,5 @@
 CPU_VARIANT = x2
 
-VECTORS_O = $(BINDIR)/cc26xx_cc13xx/vectors.o
-
 ROM_START_ADDR ?= 0x00000000
 RAM_START_ADDR ?= 0x20000000
 ROM_LEN ?= 352K

cpu/efm32/families/efm32gg/Makefile.include

@@ -3,8 +3,5 @@
 # as easy as adding the header file only.
 EFM32_HEADER = $(wildcard $(RIOTCPU)/efm32/families/efm32gg/include/vendor/$(CPU_MODEL).h)
 
-# vectors.o is provided by 'cpu_$(CPU_FAM)' module and not by 'cpu'
-VECTORS_O = $(BINDIR)/cpu_efm32gg/vectors.o
-
 # include vendor device headers
 INCLUDES += -I$(RIOTCPU)/efm32/families/efm32gg/include/vendor

cpu/efm32/families/efm32lg/Makefile.include

@@ -3,8 +3,5 @@
 # as easy as adding the header file only.
 EFM32_HEADER = $(wildcard $(RIOTCPU)/efm32/families/efm32lg/include/vendor/$(CPU_MODEL).h)
 
-# vectors.o is provided by 'cpu_$(CPU_FAM)' module and not by 'cpu'
-VECTORS_O = $(BINDIR)/cpu_efm32lg/vectors.o
-
 # include vendor device headers
 INCLUDES += -I$(RIOTCPU)/efm32/families/efm32lg/include/vendor

cpu/efm32/families/efm32pg12b/Makefile.include

@@ -3,8 +3,5 @@
 # as easy as adding the header file only.
 EFM32_HEADER = $(wildcard $(RIOTCPU)/efm32/families/efm32pg12b/include/vendor/$(CPU_MODEL).h)
 
-# vectors.o is provided by 'cpu_$(CPU_FAM)' module and not by 'cpu'
-VECTORS_O = $(BINDIR)/cpu_efm32pg12b/vectors.o
-
 # include vendor device headers
 INCLUDES += -I$(RIOTCPU)/efm32/families/efm32pg12b/include/vendor

cpu/efm32/families/efm32pg1b/Makefile.include

@@ -3,8 +3,5 @@
 # as easy as adding the header file only.
 EFM32_HEADER = $(wildcard $(RIOTCPU)/efm32/families/efm32pg1b/include/vendor/$(CPU_MODEL).h)
 
-# vectors.o is provided by 'cpu_$(CPU_FAM)' module and not by 'cpu'
-VECTORS_O = $(BINDIR)/cpu_efm32pg1b/vectors.o
-
 # include vendor device headers
 INCLUDES += -I$(RIOTCPU)/efm32/families/efm32pg1b/include/vendor

cpu/efm32/families/efr32mg12p/Makefile.include

@@ -3,8 +3,5 @@
 # as easy as adding the header file only.
 EFM32_HEADER = $(wildcard $(RIOTCPU)/efm32/families/efr32mg12p/include/vendor/$(CPU_MODEL).h)
 
-# vectors.o is provided by 'cpu_$(CPU_FAM)' module and not by 'cpu'
-VECTORS_O = $(BINDIR)/cpu_efr32mg12p/vectors.o
-
 # include vendor device headers
 INCLUDES += -I$(RIOTCPU)/efm32/families/efr32mg12p/include/vendor

cpu/efm32/families/efr32mg1p/Makefile.include

@@ -3,8 +3,5 @@
 # as easy as adding the header file only.
 EFM32_HEADER = $(wildcard $(RIOTCPU)/efm32/families/efr32mg1p/include/vendor/$(CPU_MODEL).h)
 
-# vectors.o is provided by 'cpu_$(CPU_FAM)' module and not by 'cpu'
-VECTORS_O = $(BINDIR)/cpu_efr32mg1p/vectors.o
-
 # include vendor device headers
 INCLUDES += -I$(RIOTCPU)/efm32/families/efr32mg1p/include/vendor

cpu/esp32/Makefile.include

@@ -59,19 +59,19 @@ LINKFLAGS += -T$(RIOTCPU)/$(CPU)/ld/esp32.rom.ld
 LINKFLAGS += -T$(RIOTCPU)/$(CPU)/ld/esp32.rom.nanofmt.ld
 LINKFLAGS += -nostdlib -lgcc -Wl,-gc-sections
 
-# Baselibs needed when using esp_wifi_any pseudomodule
+# Libraries needed when using esp_wifi_any pseudomodule
 ifneq (,$(filter esp_wifi_any,$(USEMODULE)))
-  BASELIBS += -lcore -lrtc -lnet80211 -lpp -lcoexist -lwps -lwpa -lwpa2
-  BASELIBS += -lphy -lstdc++
+  ARCHIVES += -lcore -lrtc -lnet80211 -lpp -lcoexist -lwps -lwpa -lwpa2
+  ARCHIVES += -lphy -lstdc++
 endif
 
-# Baselibs needed when using esp_now module
+# Libraries needed when using esp_now module
 ifneq (,$(filter esp_now,$(USEMODULE)))
-  BASELIBS += -lespnow -lmesh
+  ARCHIVES += -lespnow -lmesh
 endif
 
 ifneq (,$(filter cpp,$(FEATURES_USED)))
-  BASELIBS += -lstdc++
+  ARCHIVES += -lstdc++
 endif
 
 # additional flasher configuration for ESP32 QEMU

cpu/esp8266/Makefile.include

@@ -55,10 +55,10 @@ ifneq (,$(filter esp_gdbstub,$(USEMODULE)))
 endif
 
 ifneq (,$(filter esp_now,$(USEMODULE)))
-  BASELIBS += -lespnow
+  ARCHIVES += -lespnow
 endif
 
-BASELIBS += -lgcc -lwpa -lcore -lnet80211 -lphy -lpp -lstdc++
+ARCHIVES += -lgcc -lwpa -lcore -lnet80211 -lphy -lpp -lstdc++
 
 LINKFLAGS += -T$(RIOTCPU)/$(CPU)/ld/esp8266.rom.ld
 LINKFLAGS += -T$(RIOTCPU)/$(CPU)/ld/esp8266.riot-os.ld

cpu/esp_common/Makefile.include

@@ -36,9 +36,6 @@ OPTIONAL_CFLAGS_BLACKLIST += -gz
 
 ASFLAGS += --longcalls --text-section-literals
 
-# thin archives trigger a reboot loop - see #12258, #12035, #12346
-ARFLAGS = rcs
-
 CFLAGS_DBG ?= -ggdb -g3
 
 # override default CFLAGS_OPT in case module esp_gdb is enabled
@@ -80,7 +77,7 @@ CFLAGS += $(if $(findstring qio,$(FLASH_MODE)),-DFLASH_MODE_QIO=1)
 CFLAGS += $(if $(findstring dio,$(FLASH_MODE)),-DFLASH_MODE_DIO=1)
 CFLAGS += $(if $(findstring dout,$(FLASH_MODE)),-DFLASH_MODE_DOUT=1)
 
-BASELIBS += -lhal -lg -lc
+ARCHIVES += -lhal -lg -lc
 
 LINKFLAGS += $(CFLAGS_OPT) $(CFLAGS_DBG)
 LINKFLAGS += -L$(ESP_SDK_DIR)/components/$(CPU)

cpu/kinetis/Makefile.include

@@ -37,7 +37,4 @@ CFLAGS += \
   -DKINETIS_ROMSIZE=$(KINETIS_ROMSIZE) \
   #
 
-# add the CPU specific flash configuration field for the linker
-UNDEF += $(BINDIR)/cpu/fcfield.o
-
 include $(RIOTMAKE)/arch/cortexm.inc.mk

cpu/mips32r2_common/newlib_syscalls_mips_uhi/syscalls.c

@@ -46,6 +46,8 @@ extern char _sheap; /* start of the heap */
 extern char _eheap; /* end of the heap */
 char *heap_top = &_sheap + 4;
 
+/* Only need to define these when MIPS newlib is not used */
+#ifndef __mips__
 /**
  * @brief Free resources on NewLib de-initialization, not used for RIOT
  */
@@ -97,6 +99,7 @@ void *_sbrk_r(struct _reent *r, ptrdiff_t incr)
     irq_restore(state);
     return res;
 }
+#endif /*__mips__*/
 
 /**
 * @brief Get the process-ID of the current thread

cpu/msp430_common/Makefile.include

@@ -2,7 +2,5 @@ INCLUDES += -I$(RIOTCPU)/msp430_common/include/
 
 CFLAGS += -DCPU_MODEL_$(call uppercase_and_underscore,$(CPU_MODEL))
 
-UNDEF += $(BINDIR)/msp430_common/startup.o
-
 # include the msp430 common Makefile
 include $(RIOTMAKE)/arch/msp430.inc.mk

cpu/native/Makefile

@@ -1,7 +1,10 @@
 MODULE = cpu
 
 DIRS += periph
-DIRS += vfs
+
+ifneq (,$(filter native_vfs,$(USEMODULE)))
+  DIRS += vfs
+endif
 
 ifeq ($(OS),Darwin)
   CFLAGS += -D_XOPEN_SOURCE=600 -D_DARWIN_C_SOURCE

makefiles/arch/atmega.inc.mk

@@ -11,10 +11,6 @@ ASFLAGS   += $(CFLAGS_CPU) $(CFLAGS_DBG)
 LINKFLAGS += $(CFLAGS_CPU) $(CFLAGS_DBG) $(CFLAGS_OPT) -static -lgcc -e reset_handler -Wl,--gc-sections
 OFLAGS    += -j .text -j .data
 
-# explicitly tell the linker to link the syscalls and startup code.
-# without this the interrupt vectors will not be linked correctly!
-UNDEF += $(BINDIR)/atmega_common/startup.o
-
 # Use ROM_LEN and RAM_LEN during link
 $(if $(ROM_LEN),,$(error ROM_LEN is not defined))
 $(if $(RAM_LEN),,$(error RAM_LEN is not defined))

makefiles/arch/cortexm.inc.mk

@@ -102,13 +102,6 @@ ifneq (,$(filter cmsis-dsp,$(USEPKG)))
   endif
 endif
 
-# Explicitly tell the linker to link the startup code.
-#   Without this the interrupt vectors will not be linked correctly!
-VECTORS_O ?= $(BINDIR)/cpu/vectors.o
-ifeq ($(COMMON_STARTUP),)
-  UNDEF += $(VECTORS_O)
-endif
-
 # CPU depends on the cortex-m common module, so include it:
 include $(RIOTCPU)/cortexm_common/Makefile.include
 

makefiles/cflags.inc.mk

@@ -38,6 +38,10 @@ endif
 # Forbid common symbols to prevent accidental aliasing.
 CFLAGS += -fno-common
 
+# Place data and functions into their own sections. This helps the linker
+# garbage collection to remove unused symbols when linking statically.
+CFLAGS += -ffunction-sections -fdata-sections
+
 # Compress debug info. This saves approximately 50% of disk usage.
 # It has no effect if debugging information is not emitted, so it can be left
 # on unconditionally.
@@ -61,9 +65,3 @@ endif
 
 # Add the optional flags that are not architecture/toolchain blacklisted
 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 = rcTs
-endif