ci/build_system_check: improve check for features only provided in Makefile.features

[aabadie]

Contribution description

This PR improves the build system sanity checks to be able to detect the use of FEATURES_PROVIDED in files other than Makefile.features: it nows checks for path other than only cpu/boards and it take into account potential spaces at the beginning of lines where it is used.

This allows for catching things like:

RIOT/drivers/Makefile.dep

Line 672 in 60def88

FEATURES_PROVIDED += periph_rtc

Testing procedure

• Static tests should pass. Without drivers/Makefile.dep: remove inappropriate use of FEATURES_PROVIDED for rtt_rtc #14497 being merged, the check correctly catch the problem mentioned above:

$ ./dist/tools/buildsystem_sanity_check/check.sh 
Invalid build system patterns found by ./dist/tools/buildsystem_sanity_check/check.sh:
Features in cpu and boards should only be provided in Makefile.features files
	drivers/Makefile.dep:  FEATURES_PROVIDED += periph_rtc

• One can also apply the following patches to verify there's no regression in the check:

Details

diff --git a/boards/6lowpan-clicker/Makefile.dep b/boards/6lowpan-clicker/Makefile.dep
index 2fa80dd76e..74b92b3e78 100644
--- a/boards/6lowpan-clicker/Makefile.dep
+++ b/boards/6lowpan-clicker/Makefile.dep
@@ -3,3 +3,5 @@ ifneq (,$(filter saul_default,$(USEMODULE)))
 endif
 
 USEMODULE += newlib_syscalls_mips_uhi
+
+FEATURES_PROVIDED += periph_uart
diff --git a/boards/6lowpan-clicker/Makefile.include b/boards/6lowpan-clicker/Makefile.include
index 9ac719b33b..e9e449090c 100644
--- a/boards/6lowpan-clicker/Makefile.include
+++ b/boards/6lowpan-clicker/Makefile.include
@@ -14,3 +14,5 @@ ifeq ($(PROGRAMMER),pic32prog)
   FLASHFILE ?= $(HEXFILE)
   include $(RIOTMAKE)/tools/pic32prog.inc.mk
 endif
+
+FEATURES_PROVIDED += periph_uart

results in:

./dist/tools/buildsystem_sanity_check/check.sh 
Invalid build system patterns found by ./dist/tools/buildsystem_sanity_check/check.sh:
Features should only be provided in Makefile.features files
	boards/6lowpan-clicker/Makefile.dep:FEATURES_PROVIDED += periph_uart
	boards/6lowpan-clicker/Makefile.include:FEATURES_PROVIDED += periph_uart
	drivers/Makefile.dep:  FEATURES_PROVIDED += periph_rtc

git diff
diff --git a/cpu/stm32/Makefile.dep b/cpu/stm32/Makefile.dep
index 56bbbc945b..96a3abc50b 100644
--- a/cpu/stm32/Makefile.dep
+++ b/cpu/stm32/Makefile.dep
@@ -17,3 +17,5 @@ ifneq (,$(filter periph_uart_nonblocking,$(USEMODULE)))
 endif
 
 include $(RIOTCPU)/cortexm_common/Makefile.dep
+
+FEATURES_PROVIDED += periph_wdt
diff --git a/cpu/stm32/Makefile.include b/cpu/stm32/Makefile.include
index b0f9a4a681..61057737fd 100644
--- a/cpu/stm32/Makefile.include
+++ b/cpu/stm32/Makefile.include
@@ -46,3 +46,5 @@ endif
 VECTORS_O ?= $(BINDIR)/stm32_vectors/vectors_$(CPU_FAM).o
 
 include $(RIOTMAKE)/arch/cortexm.inc.mk
+
+FEATURES_PROVIDED += periph_wdt

results in:

./dist/tools/buildsystem_sanity_check/check.sh 
Invalid build system patterns found by ./dist/tools/buildsystem_sanity_check/check.sh:
Features should only be provided in Makefile.features files
	cpu/stm32/Makefile.dep:FEATURES_PROVIDED += periph_wdt
	cpu/stm32/Makefile.include:FEATURES_PROVIDED += periph_wdt
	drivers/Makefile.dep:  FEATURES_PROVIDED += periph_rtc

Issues/PRs references

Will work when #14497 is merged

[fjmolinas]

Is there any reason for features to be provided by something else than BOARD'S or CPU'S?

[aabadie]

Is there any reason for features to be provided by something else than BOARD'S or CPU'S?

Apparently, there's still the question about modules that could provide features. I noticed something of this kind was merged into master for rtt_rtc:

RIOT/drivers/Makefile.dep

Line 672 in 60def88

FEATURES_PROVIDED += periph_rtc

This PR adds a check to prevent that.

[fjmolinas]

Discussed offline with @aabadie, I had an issue with the change since currently FEATURES should only be provided by BOARDS and CPUS. Since currently Makefile.feature only exist for those this change is OK.

[aabadie]

rebased now that #14497 is merged. It should pass the CI now.

[aabadie]

ping @fjmolinas

[fjmolinas]

ACK