From f5e9e1a4f5680476d265850262c908dda051db92 Mon Sep 17 00:00:00 2001
From: Kefu Chai <tchaikov@gmail.com>
Date: Wed, 10 Aug 2022 20:10:42 +0800
Subject: [PATCH] cmake: find motr libraries and header before using them

cmake should fail when generating the building system, if the necessary
development libraries or the header files are missing.

in this change, Findmotr.cmake is added to detect the motr library
and header so that we can use it to find the motr package before using
it.

See-also: https://tracker.ceph.com/issues/57079
Signed-off-by: Kefu Chai <tchaikov@gmail.com>
---
 cmake/modules/Findmotr.cmake | 50 ++++++++++++++++++++++++++++++++++++
 src/rgw/CMakeLists.txt       |  7 ++---
 2 files changed, 52 insertions(+), 5 deletions(-)
 create mode 100644 cmake/modules/Findmotr.cmake

diff --git a/cmake/modules/Findmotr.cmake b/cmake/modules/Findmotr.cmake
new file mode 100644
index 00000000000..5ac0ef697e1
--- /dev/null
+++ b/cmake/modules/Findmotr.cmake
@@ -0,0 +1,50 @@
+# - Find libmotr
+# Find the motr and motrhl libraries and includes
+#
+# motr_INCLUDE_DIR - where to find motr.hpp etc.
+# motr_LIBRARIES - List of libraries when using motr.
+# motr_FOUND - True if motr found.
+
+find_package(PkgConfig QUIET REQUIRED)
+pkg_search_module(PC_motr QUIET motr)
+
+find_path(motr_INCLUDE_DIR
+  NAMES motr/config.h
+  HINTS ${PC_motr_INCLUDE_DIRS})
+find_library(motr_LIBRARY
+  NAMES motr
+  HINTS ${PC_motr_LIBRARY_DIRS})
+find_library(motr_helpers_LIBRARY
+  NAMES motr-helpers
+  HINTS ${PC_motr_LIBRARY_DIRS})
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(motr
+  DEFAULT_MSG
+  motr_INCLUDE_DIR
+  motr_LIBRARY
+  motr_helpers_LIBRARY)
+
+mark_as_advanced(
+  motr_INCLUDE_DIR
+  motr_LIBRARY
+  motr_helpers_LIBRARY)
+
+if(motr_FOUND)
+  set(motr_LIBRARIES ${motr_LIBRARY} ${motr_helpers_LIBRARY})
+  if(NOT (TARGET motr::helpers))
+    add_library(motr::helpers UNKNOWN IMPORTED)
+    set_target_properties(motr::helpers PROPERTIES
+      IMPORTED_LOCATION "${motr_helpers_LIBRARY}")
+  endif()
+  if(NOT (TARGET motr::motr))
+    add_library(motr::motr UNKNOWN IMPORTED)
+    set_target_properties(motr::motr PROPERTIES
+      INTERFACE_COMPILE_DEFINITIONS "M0_EXTERN=extern;M0_INTERNAL="
+      INTERFACE_COMPILE_OPTIONS "-Wno-attributes"
+      INTERFACE_INCLUDE_DIRECTORIES "${motr_INCLUDE_DIR}"
+      INTERFACE_LINK_LIBRARIES motr::helpers
+      IMPORTED_LINK_INTERFACE_LANGUAGES "C"
+      IMPORTED_LOCATION "${motr_LIBRARY}")
+  endif()
+endif()
diff --git a/src/rgw/CMakeLists.txt b/src/rgw/CMakeLists.txt
index 1b392cdf795..3ac721f0fd6 100644
--- a/src/rgw/CMakeLists.txt
+++ b/src/rgw/CMakeLists.txt
@@ -264,11 +264,8 @@ if(WITH_RADOSGW_DBSTORE)
 endif()
 
 if(WITH_RADOSGW_MOTR)
-  target_include_directories(rgw_common PRIVATE "/usr/include/motr")
-  target_compile_options(rgw_common PRIVATE "-Wno-attributes")
-  target_compile_definitions(rgw_common
-    PRIVATE "M0_EXTERN=extern" "M0_INTERNAL=")
-  target_link_libraries(rgw_common PRIVATE motr motr-helpers)
+  find_package(motr REQUIRED)
+  target_link_libraries(rgw_common PRIVATE motr::motr)
 endif()
 
 set(rgw_a_srcs
-- 
2.39.5