From: Andi Kleen <[email protected]> gcc 5 supports a new -mcount-record option to generate ftrace tables directly. This avoids the need to run record_mcount manually.
Use this option when available. So far doesn't use -mcount-nop, which also exists now. This is needed to make ftrace work with LTO because the normal record-mcount script doesn't run over the link time output. It should also improve build times slightly in the general case. Cc: [email protected] Signed-off-by: Andi Kleen <[email protected]> --- scripts/Makefile.build | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/scripts/Makefile.build b/scripts/Makefile.build index cb8997ed0149..8179563bcd85 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -219,6 +219,11 @@ cmd_modversions_c = \ endif ifdef CONFIG_FTRACE_MCOUNT_RECORD +# gcc 5 supports generating the mcount tables directly +ifneq ($(call cc-option,-mrecord-mcount,y),y) +KBUILD_CFLAGS += -mrecord-mcount +else +# else do it all manually ifdef BUILD_C_RECORDMCOUNT ifeq ("$(origin RECORDMCOUNT_WARN)", "command line") RECORDMCOUNT_FLAGS = -w @@ -264,6 +269,7 @@ objtool_args += --no-unreachable else objtool_args += $(call cc-ifversion, -lt, 0405, --no-unreachable) endif +endif # 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory # 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file -- 2.13.6
