[PATCH v1 1/3] perf build: Add libnvme feature detection

[Ian Rogers <irogers@google.com>]

Introduce a feature check for libnvme so that we can conditionally
compile the NVMe PMU driver. This checks for the availability of the
libnvme headers and library using pkg-config.

Signed-off-by: Ian Rogers <irogers@google.com>
CONV=ca4c5d09-4ef8-405a-80bb-aa988020b436
TAG=agy
---
 tools/build/Makefile.feature       |  2 ++
 tools/build/feature/Makefile       |  3 +++
 tools/build/feature/test-libnvme.c | 11 +++++++++++
 tools/perf/Makefile.config         | 12 ++++++++++++
 4 files changed, 28 insertions(+)
 create mode 100644 tools/build/feature/test-libnvme.c

diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature
index ed1374af31c1..bf8503241539 100644
--- a/tools/build/Makefile.feature
+++ b/tools/build/Makefile.feature
@@ -73,6 +73,7 @@ FEATURE_TESTS_BASIC :=                  \
         libbfd                          \
 	libbfd-threadsafe		\
         libelf                          \
+        libnvme                         \
         libelf-getphdrnum               \
         libelf-gelf_getnote             \
         libelf-getshdrstrndx            \
@@ -146,6 +147,7 @@ FEATURE_DISPLAY ?=              \
          libdw                  \
          glibc                  \
          libelf                 \
+         libnvme                \
          libnuma                \
          numa_num_possible_cpus \
          libpython              \
diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile
index 62909a9c799d..fd00e0be6069 100644
--- a/tools/build/feature/Makefile
+++ b/tools/build/feature/Makefile
@@ -147,6 +147,9 @@ $(OUTPUT)test-libcap.bin:
 $(OUTPUT)test-libelf.bin:
 	$(BUILD) -lelf
 
+$(OUTPUT)test-libnvme.bin:
+	$(BUILD) -lnvme
+
 $(OUTPUT)test-eventfd.bin:
 	$(BUILD)
 
diff --git a/tools/build/feature/test-libnvme.c b/tools/build/feature/test-libnvme.c
new file mode 100644
index 000000000000..3fefad70a680
--- /dev/null
+++ b/tools/build/feature/test-libnvme.c
@@ -0,0 +1,11 @@
+// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
+#include <libnvme.h>
+
+int main(void)
+{
+	nvme_root_t r = nvme_scan(NULL);
+
+	if (r)
+		nvme_free_tree(r);
+	return 0;
+}
diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index 6e7b15fab2ec..79c4ad10bc18 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -1060,6 +1060,18 @@ ifndef NO_CAPSTONE
   endif
 endif
 
+ifndef NO_LIBNVME
+  $(call feature_check,libnvme)
+  ifeq ($(feature-libnvme), 1)
+    CFLAGS += -DHAVE_LIBNVME_SUPPORT $(shell $(PKG_CONFIG) --cflags libnvme)
+    LDFLAGS += $(shell $(PKG_CONFIG) --libs-only-L libnvme)
+    EXTLIBS += $(shell $(PKG_CONFIG) --libs-only-l libnvme)
+    $(call detected,CONFIG_LIBNVME)
+  else
+    msg := $(warning No libnvme found, disables NVMe PMU support, please install libnvme-dev/libnvme-devel);
+  endif
+endif
+
 ifdef EXTRA_TESTS
     $(call detected,CONFIG_EXTRA_TESTS)
     CFLAGS += -DHAVE_EXTRA_TESTS
-- 
2.54.0.1064.gd145956f57-goog