The following errors are showing up when compiling rtla with clang:

 $ make HOSTCC=clang CC=clang LLVM_IAS=1
 [...]

  clang -O -g -DVERSION=\"6.8.0-rc1\" -flto=auto -ffat-lto-objects
        -fexceptions -fstack-protector-strong
        -fasynchronous-unwind-tables -fstack-clash-protection  -Wall
        -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2
        -Wp,-D_GLIBCXX_ASSERTIONS -Wno-maybe-uninitialized
        $(pkg-config --cflags libtracefs)    -c -o src/utils.o src/utils.c

  clang: warning: optimization flag '-ffat-lto-objects' is not supported 
[-Wignored-optimization-argument]
  warning: unknown warning option '-Wno-maybe-uninitialized'; did you mean 
'-Wno-uninitialized'? [-Wunknown-warning-option]
  1 warning generated.

  clang -o rtla -ggdb  src/osnoise.o src/osnoise_hist.o src/osnoise_top.o
  src/rtla.o src/timerlat_aa.o src/timerlat.o src/timerlat_hist.o
  src/timerlat_top.o src/timerlat_u.o src/trace.o src/utils.o $(pkg-config 
--libs libtracefs)

  src/osnoise.o: file not recognized: file format not recognized
  clang: error: linker command failed with exit code 1 (use -v to see 
invocation)
  make: *** [Makefile:110: rtla] Error 1

Solve these issues by:
  - removing -ffat-lto-objects and -Wno-maybe-uninitialized if using clang
  - informing the linker about -flto=auto

Cc: sta...@vger.kernel.org
Fixes: 1a7b22ab15eb ("tools/rtla: Build with EXTRA_{C,LD}FLAGS")
Suggested-by: Donald Zickus <dzic...@redhat.com>
Signed-off-by: Daniel Bristot de Oliveira <bris...@kernel.org>
---
 tools/tracing/rtla/Makefile | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/tools/tracing/rtla/Makefile b/tools/tracing/rtla/Makefile
index 2456a399eb9a..afd18c678ff5 100644
--- a/tools/tracing/rtla/Makefile
+++ b/tools/tracing/rtla/Makefile
@@ -28,10 +28,15 @@ FOPTS       :=      -flto=auto -ffat-lto-objects 
-fexceptions -fstack-protector-strong \
                -fasynchronous-unwind-tables -fstack-clash-protection
 WOPTS  :=      -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 
-Wp,-D_GLIBCXX_ASSERTIONS -Wno-maybe-uninitialized
 
+ifeq ($(CC),clang)
+  FOPTS := $(filter-out -ffat-lto-objects, $(FOPTS))
+  WOPTS := $(filter-out -Wno-maybe-uninitialized, $(WOPTS))
+endif
+
 TRACEFS_HEADERS        := $$($(PKG_CONFIG) --cflags libtracefs)
 
 CFLAGS :=      -O -g -DVERSION=\"$(VERSION)\" $(FOPTS) $(MOPTS) $(WOPTS) 
$(TRACEFS_HEADERS) $(EXTRA_CFLAGS)
-LDFLAGS        :=      -ggdb $(EXTRA_LDFLAGS)
+LDFLAGS        :=      -flto=auto -ggdb $(EXTRA_LDFLAGS)
 LIBS   :=      $$($(PKG_CONFIG) --libs libtracefs)
 
 SRC    :=      $(wildcard src/*.c)
-- 
2.43.0


Reply via email to