[PATCH v3 1/3] tools build: Add feature test for libelf with ZSTD

[Leo Yan]

The macro ELFCOMPRESS_ZSTD defines the compress algorithm, which was
introduced in the commit ("libelf: Document and make ELFCOMPRESS_ZSTD
usable with old system elf.h") of the repository elfutils-0.188-67.
Therefore, libelf 0.189 and later versions require to link the libzstd
library.

Add a test for checking if libelf supports ZSTD algorithm.  Pass the
macro ELFCOMPRESS_ZSTD as an argument to the elf_compress() function.
If the build succeeds, it means the feature is supported.

Signed-off-by: Leo Yan <leo.yan@xxxxxxx>
Tested-by: Quentin Monnet <qmo@xxxxxxxxxx>
Reviewed-by: Quentin Monnet <qmo@xxxxxxxxxx>
Tested-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
---
 tools/build/Makefile.feature           | 1 +
 tools/build/feature/Makefile           | 4 ++++
 tools/build/feature/test-all.c         | 4 ++++
 tools/build/feature/test-libelf-zstd.c | 9 +++++++++
 4 files changed, 18 insertions(+)
 create mode 100644 tools/build/feature/test-libelf-zstd.c

diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature
index e25cdb7db40e..ce2f37f62dfc 100644
--- a/tools/build/Makefile.feature
+++ b/tools/build/Makefile.feature
@@ -77,6 +77,7 @@ FEATURE_TESTS_BASIC :=                  \
         libelf-getphdrnum               \
         libelf-gelf_getnote             \
         libelf-getshdrstrndx            \
+        libelf-zstd                     \
         libnuma                         \
         numa_num_possible_cpus          \
         libperl                         \
diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile
index cbf751b6f0f7..680f9b07150f 100644
--- a/tools/build/feature/Makefile
+++ b/tools/build/feature/Makefile
@@ -28,6 +28,7 @@ FILES=                                          \
          test-libelf-getphdrnum.bin             \
          test-libelf-gelf_getnote.bin           \
          test-libelf-getshdrstrndx.bin          \
+         test-libelf-zstd.bin                   \
          test-libdebuginfod.bin                 \
          test-libnuma.bin                       \
          test-numa_num_possible_cpus.bin        \
@@ -196,6 +197,9 @@ $(OUTPUT)test-libelf-gelf_getnote.bin:
 $(OUTPUT)test-libelf-getshdrstrndx.bin:
 	$(BUILD) -lelf
 
+$(OUTPUT)test-libelf-zstd.bin:
+	$(BUILD) -lelf -lz -lzstd
+
 $(OUTPUT)test-libdebuginfod.bin:
 	$(BUILD) -ldebuginfod
 
diff --git a/tools/build/feature/test-all.c b/tools/build/feature/test-all.c
index 80ac297f8196..67125f967860 100644
--- a/tools/build/feature/test-all.c
+++ b/tools/build/feature/test-all.c
@@ -58,6 +58,10 @@
 # include "test-libelf-getshdrstrndx.c"
 #undef main
 
+#define main main_test_libelf_zstd
+# include "test-libelf-zstd.c"
+#undef main
+
 #define main main_test_libslang
 # include "test-libslang.c"
 #undef main
diff --git a/tools/build/feature/test-libelf-zstd.c b/tools/build/feature/test-libelf-zstd.c
new file mode 100644
index 000000000000..a1324a1db3bb
--- /dev/null
+++ b/tools/build/feature/test-libelf-zstd.c
@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stddef.h>
+#include <libelf.h>
+
+int main(void)
+{
+	elf_compress(NULL, ELFCOMPRESS_ZSTD, 0);
+	return 0;
+}
-- 
2.34.1