perf build: Combine test-dwarf-getlocations into test-libdw

dwarf_getlocations support in libdw is more than 10 years old. Make
libdw imply dwarf_getlocations support and simplify build logic.

Signed-off-by: Ian Rogers <[e-mail]>
Acked-by: Namhyung Kim <[e-mail]>
Tested-by: Leo Yan <[e-mail]>
Cc: Anup Patel <[e-mail]>
Cc: Yang Jihong <[e-mail]>
Cc: Palmer Dabbelt <[e-mail]>
Cc: David S. Miller <[e-mail]>
Cc: Albert Ou <[e-mail]>
Cc: Shenlin Liang <[e-mail]>
Cc: Nick Terrell <[e-mail]>
Cc: Guilherme Amadio <[e-mail]>
Cc: Steinar H. Gunderson <[e-mail]>
Cc: Changbin Du <[e-mail]>
Cc: Alexander Lobakin <[e-mail]>
Cc: Przemek Kitszel <[e-mail]>
Cc: Huacai Chen <[e-mail]>
Cc: Guo Ren <[e-mail]>
Cc: Masahiro Yamada <[e-mail]>
Cc: Masami Hiramatsu (Google) <[e-mail]>
Cc: Will Deacon <[e-mail]>
Cc: James Clark <[e-mail]>
Cc: Mike Leach <[e-mail]>
Cc: Chen Pei <[e-mail]>
Cc: Leo Yan <[e-mail]>
Cc: Oliver Upton <[e-mail]>
Cc: Aditya Gupta <[e-mail]>
Cc: Kajol Jain <[e-mail]>
Cc: Athira Rajeev <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Cc: Bibo Mao <[e-mail]>
Cc: John Garry <[e-mail]>
Cc: Atish Patra <[e-mail]>
Cc: Dima Kogan <[e-mail]>
Cc: Paul Walmsley <[e-mail]>
Cc: Dr. David Alan Gilbert <[e-mail]>
Cc: [e-mail]
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Namhyung Kim <[e-mail]>

tools/build/Makefile.feature

···
 FEATURE_TESTS_BASIC :=                  \
         backtrace                       \
         libdw                           \
-        dwarf_getlocations              \
         dwarf_getcfi                    \
         eventfd                         \
         fortify-source                  \
···
 
 FEATURE_DISPLAY ?=              \
          libdw                  \
-         dwarf_getlocations     \
          glibc                  \
          libbfd                 \
          libbfd-buildid		\

tools/build/feature/Makefile

···
          test-backtrace.bin                     \
          test-bionic.bin                        \
          test-libdw.bin                         \
-         test-dwarf_getlocations.bin            \
          test-dwarf_getcfi.bin                  \
          test-eventfd.bin                       \
          test-fortify-source.bin                \
···
 endif
 
 $(OUTPUT)test-libdw.bin:
-	$(BUILD) $(DWLIBS)
-
-$(OUTPUT)test-dwarf_getlocations.bin:
 	$(BUILD) $(DWLIBS)
 
 $(OUTPUT)test-dwarf_getcfi.bin:

tools/build/feature/test-all.c

···
 # include "test-libdw.c"
 #undef main
 
-#define main main_test_dwarf_getlocations
-# include "test-dwarf_getlocations.c"
-#undef main
-
 #define main main_test_eventfd
 # include "test-eventfd.c"
 #undef main
···
 	main_test_gettid();
 	main_test_glibc();
 	main_test_libdw();
-	main_test_dwarf_getlocations();
 	main_test_eventfd();
 	main_test_libelf_getphdrnum();
 	main_test_libelf_gelf_getnote();

tools/build/feature/test-dwarf_getlocations.c

···
-// SPDX-License-Identifier: GPL-2.0
-#include <stdlib.h>
-#include <elfutils/libdw.h>
-
-int main(void)
-{
-	Dwarf_Addr base, start, end;
-	Dwarf_Attribute attr;
-	Dwarf_Op *op;
-        size_t nops;
-	ptrdiff_t offset = 0;
-        return (int)dwarf_getlocations(&attr, offset, &base, &start, &end, &op, &nops);
-}

tools/build/feature/test-libdw.c

···
 // SPDX-License-Identifier: GPL-2.0
+#include <stdlib.h>
 #include <dwarf.h>
 #include <elfutils/libdw.h>
 #include <elfutils/libdwfl.h>
···
 	return 0;
 }
 
+int test_libdw_getlocations(void)
+{
+	Dwarf_Addr base, start, end;
+	Dwarf_Attribute attr;
+	Dwarf_Op *op;
+	size_t nops;
+	ptrdiff_t offset = 0;
+
+	return (int)dwarf_getlocations(&attr, offset, &base, &start, &end, &op, &nops);
+}
+
 int main(void)
 {
-	return test_libdw() + test_libdw_unwind();
+	return test_libdw() + test_libdw_unwind() + test_libdw_getlocations();
 }

tools/perf/Makefile.config

···
 endif
 FEATURE_CHECK_CFLAGS-libdw := $(LIBDW_CFLAGS)
 FEATURE_CHECK_LDFLAGS-libdw := $(LIBDW_LDFLAGS) $(DWARFLIBS)
-FEATURE_CHECK_CFLAGS-dwarf_getlocations := $(LIBDW_CFLAGS)
-FEATURE_CHECK_LDFLAGS-dwarf_getlocations := $(LIBDW_LDFLAGS) $(DWARFLIBS)
 FEATURE_CHECK_CFLAGS-dwarf_getcfi := $(LIBDW_CFLAGS)
 FEATURE_CHECK_LDFLAGS-dwarf_getcfi := $(LIBDW_LDFLAGS) $(DWARFLIBS)
 
···
   else
     ifneq ($(feature-libdw), 1)
       ifndef NO_LIBDW
-        $(warning No libdw.h found or old libdw.h found or elfutils is older than 0.138, disables dwarf support. Please install new elfutils-devel/libdw-dev)
+        $(warning No libdw.h found or old libdw.h found or elfutils is older than 0.157, disables dwarf support. Please install new elfutils-devel/libdw-dev)
         NO_LIBDW := 1
       endif
     else
-      ifneq ($(feature-dwarf_getlocations), 1)
-        $(warning Old libdw.h, finding variables at given 'perf probe' point will not work, install elfutils-devel/libdw-dev >= 0.157)
-      else
-        CFLAGS += -DHAVE_DWARF_GETLOCATIONS_SUPPORT
-      endif # dwarf_getlocations
+      CFLAGS += -DHAVE_DWARF_GETLOCATIONS_SUPPORT
       ifneq ($(feature-dwarf_getcfi), 1)
         $(warning Old libdw.h, finding variables at given 'perf probe' point will not work, install elfutils-devel/libdw-dev >= 0.142)
       else