@@ -1,19 +1,29 @@
# SPDX-License-Identifier: GPL-2.0
# Copyright (C) 2020 ARM Limited
-# preserve CC value from top level Makefile
-ifeq ($(CC),cc)
-CC := $(CROSS_COMPILE)gcc
-endif
-
CFLAGS += -std=gnu99 -I. -pthread
LDFLAGS += -pthread
SRCS := $(filter-out mte_common_util.c,$(wildcard *.c))
PROGS := $(patsubst %.c,%,$(SRCS))
+ifeq ($(LLVM),)
+# For GCC check that the toolchain has MTE support.
+
+# preserve CC value from top level Makefile
+ifeq ($(CC),cc)
+CC := $(CROSS_COMPILE)gcc
+endif
+
#check if the compiler works well
mte_cc_support := $(shell if ($(CC) $(CFLAGS) -march=armv8.5-a+memtag -E -x c /dev/null -o /dev/null 2>&1) then echo "1"; fi)
+else
+
+# All supported clang versions also support MTE.
+mte_cc_support := 1
+
+endif
+
ifeq ($(mte_cc_support),1)
# Generated binaries to be installed by top KSFT script
TEST_GEN_PROGS := $(PROGS)
The assembly portions of the MTE selftests need to be built with a toolchain supporting MTE. Since we support GCC versions that lack MTE support we have logic to suppress build of these tests when using such a toolchain but that logic is broken for LLVM=1 builds, it uses CC but CC is only set for LLVM builds in libs.mk which needs to be included after we have selected which test programs to build. Since all supported LLVM versions support MTE we can simply assume MTE support when LLVM is set. This is not a thing of beauty but it does the job. Signed-off-by: Mark Brown <broonie@kernel.org> --- tools/testing/selftests/arm64/mte/Makefile | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-)