kbuild: Allow for ',$ in commands

Quote ',$ before passing them to the shell - ' must be escaped for
echo, $$ will be converted to $ by make.

This allows to use e.g. perl commands in the build with support
from the generic $(call if_changed,...).

by Konrad Eisele

Makefile

@@ -885,9 +885,9 @@ if_changed_dep = $(if $(strip $? $(filter-out FORCE $(wildcard $^),$^)\
 		          $(filter-out $(cmd_$(1)),$(cmd_$@))\
 			  $(filter-out $(cmd_$@),$(cmd_$(1)))),\
 	@set -e; \
-	$(if $($(quiet)cmd_$(1)),echo '  $($(quiet)cmd_$(1))';) \
+	$(if $($(quiet)cmd_$(1)),echo '  $(subst ','\'',$($(quiet)cmd_$(1)))';) \
 	$(cmd_$(1)); \
-	scripts/fixdep $(depfile) $@ '$(cmd_$(1))' > $(@D)/.$(@F).tmp; \
+	scripts/fixdep $(depfile) $@ '$(subst $$,$$$$,$(subst ','\'',$(cmd_$(1))))' > $(@D)/.$(@F).tmp; \
 	rm -f $(depfile); \
 	mv -f $(@D)/.$(@F).tmp $(@D)/.$(@F).cmd)
 

scripts/Makefile.lib

@@ -178,14 +178,16 @@ cmd_gzip = gzip -f -9 < $< > $@
 # ===========================================================================
 
 # function to only execute the passed command if necessary
+# >'< substitution is for echo to work, >$< substitution to preserve $ when reloading .cmd file
+# note: when using inline perl scripts [perl -e '...$$t=1;...'] in $(cmd_xxx) double $$ your perl vars
 
 if_changed = $(if $(strip $? \
 		          $(filter-out $(cmd_$(1)),$(cmd_$@))\
 			  $(filter-out $(cmd_$@),$(cmd_$(1)))),\
 	@set -e; \
-	$(if $($(quiet)cmd_$(1)),echo '  $($(quiet)cmd_$(1))';) \
+	$(if $($(quiet)cmd_$(1)),echo '  $(subst ','\'',$($(quiet)cmd_$(1)))';) \
 	$(cmd_$(1)); \
-	echo 'cmd_$@ := $(cmd_$(1))' > $(@D)/.$(@F).cmd)
+	echo 'cmd_$@ := $(subst $$,$$$$,$(subst ','\'',$(cmd_$(1))))' > $(@D)/.$(@F).cmd)
 
 
 # execute the command and also postprocess generated .d dependencies
@@ -195,9 +197,9 @@ if_changed_dep = $(if $(strip $? $(filter-out FORCE $(wildcard $^),$^)\
 		          $(filter-out $(cmd_$(1)),$(cmd_$@))\
 			  $(filter-out $(cmd_$@),$(cmd_$(1)))),\
 	@set -e; \
-	$(if $($(quiet)cmd_$(1)),echo '  $($(quiet)cmd_$(1))';) \
+	$(if $($(quiet)cmd_$(1)),echo '  $(subst ','\'',$($(quiet)cmd_$(1)))';) \
 	$(cmd_$(1)); \
-	scripts/fixdep $(depfile) $@ '$(cmd_$(1))' > $(@D)/.$(@F).tmp; \
+	scripts/fixdep $(depfile) $@ '$(subst $$,$$$$,$(subst ','\'',$(cmd_$(1))))' > $(@D)/.$(@F).tmp; \
 	rm -f $(depfile); \
 	mv -f $(@D)/.$(@F).tmp $(@D)/.$(@F).cmd)