dwarf_getcfi support in libdw is 15 years old. Make libdw imply
dwarf_getcfi support and simplify build logic.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/build/Makefile.feature            |  1 -
 tools/build/feature/Makefile            |  4 ----
 tools/build/feature/test-dwarf_getcfi.c |  9 ---------
 tools/build/feature/test-libdw.c        | 10 +++++++++-
 tools/perf/Makefile.config              |  8 +-------
 5 files changed, 10 insertions(+), 22 deletions(-)
 delete mode 100644 tools/build/feature/test-dwarf_getcfi.c

diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature
index cf6a967575ea..ef72aae3dd49 100644
--- a/tools/build/Makefile.feature
+++ b/tools/build/Makefile.feature
@@ -31,7 +31,6 @@ endef
 FEATURE_TESTS_BASIC :=                  \
         backtrace                       \
         libdw                           \
-        dwarf_getcfi                    \
         eventfd                         \
         fortify-source                  \
         get_current_dir_name            \
diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile
index 0af3e0255fed..d28ad7672a27 100644
--- a/tools/build/feature/Makefile
+++ b/tools/build/feature/Makefile
@@ -6,7 +6,6 @@ FILES=                                          \
          test-backtrace.bin                     \
          test-bionic.bin                        \
          test-libdw.bin                         \
-         test-dwarf_getcfi.bin                  \
          test-eventfd.bin                       \
          test-fortify-source.bin                \
          test-get_current_dir_name.bin          \
@@ -187,9 +186,6 @@ endif
 $(OUTPUT)test-libdw.bin:
 	$(BUILD) $(DWLIBS)
 
-$(OUTPUT)test-dwarf_getcfi.bin:
-	$(BUILD) $(DWLIBS)
-
 $(OUTPUT)test-libelf-getphdrnum.bin:
 	$(BUILD) -lelf
 
diff --git a/tools/build/feature/test-dwarf_getcfi.c b/tools/build/feature/test-dwarf_getcfi.c
deleted file mode 100644
index 50e7d7cb7bdf..000000000000
--- a/tools/build/feature/test-dwarf_getcfi.c
+++ /dev/null
@@ -1,9 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-#include <stdio.h>
-#include <elfutils/libdw.h>
-
-int main(void)
-{
-	Dwarf *dwarf = NULL;
-	return dwarf_getcfi(dwarf) == NULL;
-}
diff --git a/tools/build/feature/test-libdw.c b/tools/build/feature/test-libdw.c
index 83ea5d5f235d..71c6f8e3b0ee 100644
--- a/tools/build/feature/test-libdw.c
+++ b/tools/build/feature/test-libdw.c
@@ -34,7 +34,15 @@ int test_libdw_getlocations(void)
 	return (int)dwarf_getlocations(&attr, offset, &base, &start, &end, &op, &nops);
 }
 
+int test_libdw_getcfi(void)
+{
+	Dwarf *dwarf = NULL;
+
+	return dwarf_getcfi(dwarf) == NULL;
+}
+
 int main(void)
 {
-	return test_libdw() + test_libdw_unwind() + test_libdw_getlocations();
+	return test_libdw() + test_libdw_unwind() + test_libdw_getlocations() +
+	       test_libdw_getcfi();
 }
diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index fefa779041a0..6378811f2568 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -164,8 +164,6 @@ ifeq ($(findstring -static,${LDFLAGS}),-static)
 endif
 FEATURE_CHECK_CFLAGS-libdw := $(LIBDW_CFLAGS)
 FEATURE_CHECK_LDFLAGS-libdw := $(LIBDW_LDFLAGS) $(DWARFLIBS)
-FEATURE_CHECK_CFLAGS-dwarf_getcfi := $(LIBDW_CFLAGS)
-FEATURE_CHECK_LDFLAGS-dwarf_getcfi := $(LIBDW_LDFLAGS) $(DWARFLIBS)
 
 # for linking with debug library, run like:
 # make DEBUG=1 LIBBABELTRACE_DIR=/opt/libbabeltrace/
@@ -470,11 +468,7 @@ else
       endif
     else
       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
-        CFLAGS += -DHAVE_DWARF_CFI_SUPPORT
-      endif # dwarf_getcfi
+      CFLAGS += -DHAVE_DWARF_CFI_SUPPORT
     endif # Dwarf support
   endif # libelf support
 endif # NO_LIBELF
-- 
2.47.0.105.g07ac214952-goog