cmake: find MySQL client lib

This change introduces a CMake-style FindMySQL.cmake properly looking for
libmysqlclient_r with mysql_config.  This also fixes linking on some
machines.

Change-Id: Ifdbfdc3c7440dead37a8b63aaa86732d636aa0e2

cmake/FindMySQL.cmake

@@ -0,0 +1,59 @@
+# Find the MySQL includes and client library
+# This module defines
+#  MYSQL_INCLUDE_DIR, where to find mysql.h
+#  MYSQL_LIBRARIES, the libraries needed to use MySQL.
+#  MYSQL_FOUND, If false, do not try to use MySQL.
+
+set(MYSQL_CONFIG_PREFER_PATH "$ENV{MYSQL_HOME}/bin" CACHE FILEPATH
+    "preferred path to MySQL (mysql_config)")
+find_program(MYSQL_CONFIG mysql_config
+    ${MYSQL_CONFIG_PREFER_PATH}
+    /usr/local/mysql/bin/
+    /usr/local/bin/
+    /usr/bin/
+    )
+
+if(MYSQL_CONFIG)
+    message(STATUS "Using mysql_config: ${MYSQL_CONFIG}")
+    # set INCLUDE_DIR
+    exec_program(${MYSQL_CONFIG}
+        ARGS --include
+        OUTPUT_VARIABLE MYSQL_INCLUDE_DIR)
+
+    # set LIBRARY_DIR
+    exec_program(${MYSQL_CONFIG}
+        ARGS --libs_r
+        OUTPUT_VARIABLE MYSQL_LIBRARIES)
+
+else(MYSQL_CONFIG)
+    # FIXME incomplete
+    find_path(MYSQL_INCLUDE_DIR mysql.h
+        /usr/local/include
+        /usr/local/include/mysql
+        /usr/local/mysql/include
+        /usr/local/mysql/include/mysql
+        /usr/include
+        /usr/include/mysql
+    #find_library(mysqlclient ...
+    #    PATHS
+    #    ${MYSQL_ADD_LIBRARY_PATH}
+    #    /usr/lib/mysql
+    #    /usr/local/lib
+    #    /usr/local/lib/mysql
+    #    /usr/local/mysql/lib
+    #)
+)
+endif(MYSQL_CONFIG)
+
+set(MYSQL_INCLUDE_DIR ${MYSQL_INCLUDE_DIR} CACHE FILEPATH INTERNAL)
+set(MYSQL_LIBRARIES ${MYSQL_LIBRARIES} CACHE FILEPATH INTERNAL)
+
+if(MYSQL_INCLUDE_DIR AND MYSQL_LIBRARIES)
+    set(MYSQL_FOUND TRUE CACHE INTERNAL "MySQL found")
+    message(STATUS "Found MySQL: ${MYSQL_INCLUDE_DIR}, ${MYSQL_LIBRARIES}")
+else(MYSQL_INCLUDE_DIR AND MYSQL_LIBRARIES)
+    set(MYSQL_FOUND FALSE CACHE INTERNAL "MySQL found")
+    message(STATUS "MySQL not found.")
+endif(MYSQL_INCLUDE_DIR AND MYSQL_LIBRARIES)
+
+mark_as_advanced(MYSQL_INCLUDE_DIR MYSQL_LIBRARIES)