From eda93acc49e03988f6517153360fbea4850a1cfa Mon Sep 17 00:00:00 2001
From: Rodrigo Arias <rodrigo.arias@bsc.es>
Date: Thu, 2 Nov 2023 18:21:26 +0100
Subject: [PATCH] Use pkg-config to find nOS-V

---
 CHANGELOG.md                |  3 +++
 cmake/FindNosv.cmake        | 19 +++++++++++++++++++
 flake.nix                   |  2 +-
 test/rt/nosv/CMakeLists.txt | 17 ++++++-----------
 4 files changed, 29 insertions(+), 12 deletions(-)
 create mode 100644 cmake/FindNosv.cmake

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 24cb615..0eaf53f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Don't modify nOS-V subsystem state on task pause. The "Task: Running"
   state is now renamed to "Task: In body" to reflect the change.
+- Use pkg-config to locate the nOS-V library and get the version. Use
+  `PKG_CONFIG_LIBDIR=/path/to/nosv/install/lib/pkgconfig` to use a custom
+  installation path.
 
 ## [1.3.0] - 2023-09-07
 
diff --git a/cmake/FindNosv.cmake b/cmake/FindNosv.cmake
new file mode 100644
index 0000000..327d82a
--- /dev/null
+++ b/cmake/FindNosv.cmake
@@ -0,0 +1,19 @@
+# Copyright (c) 2023 Barcelona Supercomputing Center (BSC)
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+find_package(PkgConfig)
+
+if(NOT PKG_CONFIG_FOUND)
+  message(STATUS "pkg-config not found, required to locate nOSV-V")
+  return()
+endif()
+
+# Use PKG_CONFIG_LIBDIR=/path/to/nosv/install/lib/pkgconfig to use a custom
+# installation.
+pkg_search_module(NOSV IMPORTED_TARGET nos-v)
+
+if(NOT NOSV_FOUND)
+  message(STATUS "nOS-V not found")
+else()
+  message(STATUS "Found nOS-V ${NOSV_VERSION} at ${NOSV_LINK_LIBRARIES}")
+endif()
diff --git a/flake.nix b/flake.nix
index 35ea90f..a22b337 100644
--- a/flake.nix
+++ b/flake.nix
@@ -67,7 +67,7 @@
         # We need to be able to exit the chroot to run Nanos6 tests, as they
         # require access to /sys for hwloc
         __noChroot = true;
-        buildInputs = old.buildInputs ++ (with pkgs; [ nosv nanos6 nodes ]);
+        buildInputs = old.buildInputs ++ (with pkgs; [ pkg-config nosv nanos6 nodes ]);
         cmakeFlags = old.cmakeFlags ++ [ "-DENABLE_ALL_TESTS=ON" ];
         preConfigure = old.preConfigure or "" + ''
           export NODES_HOME="${pkgs.nodes}"
diff --git a/test/rt/nosv/CMakeLists.txt b/test/rt/nosv/CMakeLists.txt
index 12fa551..524558b 100644
--- a/test/rt/nosv/CMakeLists.txt
+++ b/test/rt/nosv/CMakeLists.txt
@@ -1,16 +1,13 @@
-# Copyright (c) 2021-2022 Barcelona Supercomputing Center (BSC)
+# Copyright (c) 2021-2023 Barcelona Supercomputing Center (BSC)
 # SPDX-License-Identifier: GPL-3.0-or-later
 
-find_library(nosv libnosv)
-find_path(NOSV_INCLUDE_DIR nosv.h)
+find_package(Nosv)
 
-check_library_exists(nosv nosv_init "nosv.h" HAVE_NOSV)
-
-if(NOT HAVE_NOSV)
+if(NOT NOSV_FOUND)
   if(ENABLE_ALL_TESTS)
-    message(FATAL_ERROR "nOS-V library not found, cannot enable nOS-V RT tests")
+    message(FATAL_ERROR "nOS-V not found, cannot enable nOS-V RT tests")
   else()
-    message(STATUS "nOS-V library not found, disabling nOS-V RT tests")
+    message(STATUS "nOS-V not found, disabling nOS-V RT tests")
   endif()
   return()
 else()
@@ -19,9 +16,7 @@ endif()
 
 function(nosv_test)
   ovni_test(${ARGN})
-  target_link_libraries("${OVNI_TEST_NAME}" PRIVATE nosv)
-  target_include_directories("${OVNI_TEST_NAME}"
-    PUBLIC ${NOSV_INCLUDE_DIR})
+  target_link_libraries("${OVNI_TEST_NAME}" PRIVATE PkgConfig::NOSV)
   set_property(TEST "${OVNI_TEST_NAME}" APPEND
     PROPERTY
       ENVIRONMENT "NOSV_CONFIG=${OVNI_TEST_SOURCE_DIR}/rt/nosv/nosv.toml")