Makefile.lib: cmd_dtc: warning: missing whitespace after the macro name

[Antony Pavlov <antonynpavlov@gmail.com>]

Hi Everyone!

During MIPS ath79_defconfig build I have a 'missing whitespace after the macro name' warning:

  AS [P]  arch/mips/dts/ar9331_tl_mr3020.dtb.pbl.o
  DTC     arch/mips/dts/ar9344-tl-wdr4300-v1.7.dtb
<stdin>:1:9: warning: missing whitespace after the macro name
  XZKERN  arch/mips/dts/ar9344-tl-wdr4300-v1.7.dtb.z

E.g. see https://gitlab.com/frantony/barebox/-/jobs/2969826747#L47

The reason is the scripts/Makefile.lib generates a C macro with the point symbol in the macro name because the arch/mips/dts/ar9344-tl-wdr4300-v1.7.dts file name contains the point symbol before '.dts', as a result we have:

  #define ar9344_tl_wdr4300_v1.7_dts 1

e.g.

  barebox$ grep -RHn -o "define ar9344_tl_wdr4300_v1.* 1" . 2>/dev/null
  ./arch/mips/dts/.ar9344-tl-wdr4300-v1.7.dtb.cmd:1:define ar9344_tl_wdr4300_v1.7_dts 1

cmd_dtc in scripts/Makefile.lib substitutes the '-' symbols with the '_' symbols but do nothing with other unwanted C preprocessor macro name symbols.

It looks like the linux kernel has no problems with extra point symbols in dts file names, there are several files with extra dot in dts:

  barebox$ find dts/ -iname '*.*.dts' | wc -l
  33

So we have to fix Makefile.lib.

This simple patch fixes the warning problem:

diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 16308497b84..2f79656c1e9 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -363,7 +363,7 @@ $(obj)/%.dtb.z: $(obj)/%.dtb FORCE
 dts-frags = $(subst $(quote),,$(CONFIG_EXTERNAL_DTS_FRAGMENTS))
 quiet_cmd_dtc = DTC     $@
 # For compatibility between make 4.2 and 4.3
-cmd_dtc = /usr/bin/env echo -e '$(pound)define $(subst -,_,$(*F))_dts 1\n'$(foreach f,$< $(dts-frags),'$(pound)include "$(f)"\n') | \
+cmd_dtc = /usr/bin/env echo -e '$(pound)define $(subst -,_,$(subst .,_,$(*F)))_dts 1\n'$(foreach f,$< $(dts-frags),'$(pound)include "$(f)"\n') | \
 	$(CPP) $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) - ; \
 	$(objtree)/scripts/dtc/dtc -O dtb -o $@ -b 0 \
 		-i $(srctree)/arch/$(SRCARCH)/dts $(DTC_FLAGS) \

I suppose that this simple patch may lead to some undesirable side effects.

Any suggestions?

-- 
Best regards,
  Antony Pavlov