From b4ef2e3467d8e980ccf13c9dd342459c013b455f Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Fri, 25 Oct 2019 12:56:51 +0200 Subject: Makefile.flags: suppress some clang-9 warnings Signed-off-by: Denys Vlasenko --- Makefile.flags | 25 ++++++++++++++++++++++--- 1 file changed, 22 insertions(+), 3 deletions(-) diff --git a/Makefile.flags b/Makefile.flags index bea464753..e378fbad9 100644 --- a/Makefile.flags +++ b/Makefile.flags @@ -47,12 +47,28 @@ endif # gcc 3.x emits bogus "old style proto" warning on find.c:alloc_action() CFLAGS += $(call cc-ifversion, -ge, 0400, -Wold-style-definition) -CFLAGS += $(call cc-option,-fno-builtin-strlen -finline-limit=0 -fomit-frame-pointer -ffunction-sections -fdata-sections,) +ifneq ($(CC),clang) +# "clang-9: warning: optimization flag '-finline-limit=0' is not supported +CFLAGS += $(call cc-option,-finline-limit=0,) +endif + +CFLAGS += $(call cc-option,-fno-builtin-strlen -fomit-frame-pointer -ffunction-sections -fdata-sections,) # -fno-guess-branch-probability: prohibit pseudo-random guessing # of branch probabilities (hopefully makes bloatcheck more stable): CFLAGS += $(call cc-option,-fno-guess-branch-probability,) -CFLAGS += $(call cc-option,-funsigned-char -static-libgcc,) -CFLAGS += $(call cc-option,-falign-functions=1 -falign-jumps=1 -falign-labels=1 -falign-loops=1,) +CFLAGS += $(call cc-option,-funsigned-char,) + +ifneq ($(CC),clang) +# "clang-9: warning: argument unused during compilation: '-static-libgcc'" +CFLAGS += $(call cc-option,-static-libgcc,) +endif + +CFLAGS += $(call cc-option,-falign-functions=1,) +ifneq ($(CC),clang) +# "clang-9: warning: optimization flag '-falign-jumps=1' is not supported" (and same for other two) +CFLAGS += $(call cc-option,-falign-jumps=1 -falign-labels=1 -falign-loops=1,) +endif + # Defeat .eh_frame bloat (gcc 4.6.3 x86-32 defconfig: 20% smaller busybox binary): CFLAGS += $(call cc-option,-fno-unwind-tables,) CFLAGS += $(call cc-option,-fno-asynchronous-unwind-tables,) @@ -60,6 +76,9 @@ CFLAGS += $(call cc-option,-fno-asynchronous-unwind-tables,) # (try disabling this and comparing assembly, it's instructive) CFLAGS += $(call cc-option,-fno-builtin-printf,) +# clang-9 does not like "str" + N and "if (CONFIG_ITEM && cond)" constructs +CFLAGS += $(call cc-option,-Wno-string-plus-int -Wno-constant-logical-operand) + # FIXME: These warnings are at least partially to be concerned about and should # be fixed.. #CFLAGS += $(call cc-option,-Wconversion,) -- cgit v1.2.3