|  | # Kconfig helper macros | 
|  |  | 
|  | # Convenient variables | 
|  | comma       := , | 
|  | quote       := " | 
|  | squote      := ' | 
|  | empty       := | 
|  | space       := $(empty) $(empty) | 
|  | dollar      := $ | 
|  | right_paren := ) | 
|  | left_paren  := ( | 
|  |  | 
|  | # $(if-success,<command>,<then>,<else>) | 
|  | # Return <then> if <command> exits with 0, <else> otherwise. | 
|  | if-success = $(shell,{ $(1); } >/dev/null 2>&1 && echo "$(2)" || echo "$(3)") | 
|  |  | 
|  | # $(success,<command>) | 
|  | # Return y if <command> exits with 0, n otherwise | 
|  | success = $(if-success,$(1),y,n) | 
|  |  | 
|  | # $(cc-option,<flag>) | 
|  | # Return y if the compiler supports <flag>, n otherwise | 
|  | cc-option = $(success,$(CC) -Werror $(CLANG_FLAGS) $(1) -E -x c /dev/null -o /dev/null) | 
|  |  | 
|  | # $(ld-option,<flag>) | 
|  | # Return y if the linker supports <flag>, n otherwise | 
|  | ld-option = $(success,$(LD) -v $(1)) | 
|  |  | 
|  | # gcc version including patch level | 
|  | gcc-version := $(shell,$(srctree)/scripts/gcc-version.sh -p $(CC) | sed 's/^0*//') |