perf tools: Propagate CFLAGS to libperf

Andi reported that 'make DEBUG=1' does not propagate to the libbperf
code. It's true also for the other flags. Changing the code to propagate
the global build flags to libperf compilation.

Reported-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20191011122155.15738-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/Makefile.config

@@ -188,7 +188,7 @@ endif
 
 # Treat warnings as errors unless directed not to
 ifneq ($(WERROR),0)
-  CFLAGS += -Werror
+  CORE_CFLAGS += -Werror
   CXXFLAGS += -Werror
 endif
 
@@ -198,9 +198,9 @@ endif
 
 ifeq ($(DEBUG),0)
 ifeq ($(CC_NO_CLANG), 0)
-  CFLAGS += -O3
+  CORE_CFLAGS += -O3
 else
-  CFLAGS += -O6
+  CORE_CFLAGS += -O6
 endif
 endif
 
@@ -245,12 +245,12 @@ FEATURE_CHECK_LDFLAGS-libaio = -lrt
 
 FEATURE_CHECK_LDFLAGS-disassembler-four-args = -lbfd -lopcodes -ldl
 
-CFLAGS += -fno-omit-frame-pointer
-CFLAGS += -ggdb3
-CFLAGS += -funwind-tables
-CFLAGS += -Wall
-CFLAGS += -Wextra
-CFLAGS += -std=gnu99
+CORE_CFLAGS += -fno-omit-frame-pointer
+CORE_CFLAGS += -ggdb3
+CORE_CFLAGS += -funwind-tables
+CORE_CFLAGS += -Wall
+CORE_CFLAGS += -Wextra
+CORE_CFLAGS += -std=gnu99
 
 CXXFLAGS += -std=gnu++11 -fno-exceptions -fno-rtti
 CXXFLAGS += -Wall
@@ -272,12 +272,12 @@ include $(FEATURES_DUMP)
 endif
 
 ifeq ($(feature-stackprotector-all), 1)
-  CFLAGS += -fstack-protector-all
+  CORE_CFLAGS += -fstack-protector-all
 endif
 
 ifeq ($(DEBUG),0)
   ifeq ($(feature-fortify-source), 1)
-    CFLAGS += -D_FORTIFY_SOURCE=2
+    CORE_CFLAGS += -D_FORTIFY_SOURCE=2
   endif
 endif
 
@@ -301,10 +301,12 @@ INC_FLAGS += -I$(src-perf)/util
 INC_FLAGS += -I$(src-perf)
 INC_FLAGS += -I$(srctree)/tools/lib/
 
-CFLAGS   += $(INC_FLAGS)
+CORE_CFLAGS += -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -D_GNU_SOURCE
+
+CFLAGS   += $(CORE_CFLAGS) $(INC_FLAGS)
 CXXFLAGS += $(INC_FLAGS)
 
-CFLAGS += -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -D_GNU_SOURCE
+LIBPERF_CFLAGS := $(CORE_CFLAGS) $(EXTRA_CFLAGS)
 
 ifeq ($(feature-sync-compare-and-swap), 1)
   CFLAGS += -DHAVE_SYNC_COMPARE_AND_SWAP_SUPPORT

tools/perf/Makefile.perf

@@ -769,7 +769,7 @@ $(LIBBPF)-clean:
 	$(Q)$(MAKE) -C $(BPF_DIR) O=$(OUTPUT) clean >/dev/null
 
 $(LIBPERF): FORCE
-	$(Q)$(MAKE) -C $(LIBPERF_DIR) O=$(OUTPUT) $(OUTPUT)libperf.a
+	$(Q)$(MAKE) -C $(LIBPERF_DIR) EXTRA_CFLAGS="$(LIBPERF_CFLAGS)" O=$(OUTPUT) $(OUTPUT)libperf.a
 
 $(LIBPERF)-clean:
 	$(call QUIET_CLEAN, libperf)

tools/perf/lib/core.c

@@ -5,11 +5,12 @@
 #include <stdio.h>
 #include <stdarg.h>
 #include <unistd.h>
+#include <linux/compiler.h>
 #include <perf/core.h>
 #include <internal/lib.h>
 #include "internal.h"
 
-static int __base_pr(enum libperf_print_level level, const char *format,
+static int __base_pr(enum libperf_print_level level __maybe_unused, const char *format,
 		     va_list args)
 {
 	return vfprintf(stderr, format, args);