895 endif
 896 
 897 ################################################################################
 898 # Write to and read from file
 899 
 900 # Param 1 - File to read
 901 ReadFile = \
 902     $(shell $(CAT) $1)
 903 
 904 # Param 1 - Text to write
 905 # Param 2 - File to write to
 906 ifeq ($(HAS_FILE_FUNCTION), true)
 907   WriteFile = \
 908       $(file >$2,$(strip $1))
 909 else
 910   # Use printf to get consistent behavior on all platforms.
 911   WriteFile = \
 912       $(shell $(PRINTF) "%s" $(call ShellQuote, $1) > $2)
 913 endif
 914 











 915 ################################################################################
 916 # DependOnVariable
 917 #
 918 # This macro takes a variable name and puts the value in a file only if the
 919 # value has changed since last. The name of the file is returned. This can be
 920 # used to create rule dependencies on make variable values. The following
 921 # example would get rebuilt if the value of SOME_VAR was changed:
 922 #
 923 # path/to/some-file: $(call DependOnVariable, SOME_VAR)
 924 #         echo $(SOME_VAR) > $@
 925 #
 926 # Note that leading and trailing white space in the value is ignored.
 927 #
 928 
 929 # Defines the sub directory structure to store variable value file in
 930 DependOnVariableDirName = \
 931     $(strip $(addsuffix $(if $(MODULE),/$(MODULE)), \
 932         $(subst $(TOPDIR)/,, $(if $(filter /%, $(firstword $(MAKEFILE_LIST))), \
 933           $(firstword $(MAKEFILE_LIST)), \
 934           $(CURDIR)/$(firstword $(MAKEFILE_LIST))))))

 895 endif
 896 
 897 ################################################################################
 898 # Write to and read from file
 899 
 900 # Param 1 - File to read
 901 ReadFile = \
 902     $(shell $(CAT) $1)
 903 
 904 # Param 1 - Text to write
 905 # Param 2 - File to write to
 906 ifeq ($(HAS_FILE_FUNCTION), true)
 907   WriteFile = \
 908       $(file >$2,$(strip $1))
 909 else
 910   # Use printf to get consistent behavior on all platforms.
 911   WriteFile = \
 912       $(shell $(PRINTF) "%s" $(call ShellQuote, $1) > $2)
 913 endif
 914 
 915 # Param 1 - Text to write
 916 # Param 2 - File to write to
 917 ifeq ($(HAS_FILE_FUNCTION), true)
 918   AppendFile = \
 919       $(file >>$2,$(strip $1))
 920 else
 921   # Use printf to get consistent behavior on all platforms.
 922   AppendFile = \
 923       $(shell $(PRINTF) "%s" $(call ShellQuote, $1) >> $2)
 924 endif
 925 
 926 ################################################################################
 927 # DependOnVariable
 928 #
 929 # This macro takes a variable name and puts the value in a file only if the
 930 # value has changed since last. The name of the file is returned. This can be
 931 # used to create rule dependencies on make variable values. The following
 932 # example would get rebuilt if the value of SOME_VAR was changed:
 933 #
 934 # path/to/some-file: $(call DependOnVariable, SOME_VAR)
 935 #         echo $(SOME_VAR) > $@
 936 #
 937 # Note that leading and trailing white space in the value is ignored.
 938 #
 939 
 940 # Defines the sub directory structure to store variable value file in
 941 DependOnVariableDirName = \
 942     $(strip $(addsuffix $(if $(MODULE),/$(MODULE)), \
 943         $(subst $(TOPDIR)/,, $(if $(filter /%, $(firstword $(MAKEFILE_LIST))), \
 944           $(firstword $(MAKEFILE_LIST)), \
 945           $(CURDIR)/$(firstword $(MAKEFILE_LIST))))))