Scripts: collect and reprint warnings

Closes #73

BUILD/capture_warnings.sh

@@ -0,0 +1,17 @@
+#!/bin/bash
+
+warn_path=$1
+shift
+warn_file="$warn_path/compile.warnings"
+
+set -o pipefail
+exec 3>&1
+x=$(("$@" >&2) 2>&1 1>&3)
+error=${PIPESTATUS}
+
+if ! [[ -z "$x" ]]; then
+    echo -n "$x" >> $warn_file
+    echo -n "$x" >&2
+fi
+
+exit ${error}

CMakeLists.txt

@@ -480,3 +480,17 @@ IF(NON_DISTRIBUTABLE_WARNING)
   MESSAGE(WARNING "
 You have linked MariaDB with GPLv3 libraries!  You may not distribute the resulting binary. If you do, you will put yourself into a legal problem with Free Software Foundation.")
 ENDIF()
+
+IF (CMAKE_BUILD_TYPE MATCHES "Debug")
+  SET_DIRECTORY_PROPERTIES(PROPERTIES RULE_LAUNCH_COMPILE
+    "bash ${CMAKE_SOURCE_DIR}/BUILD/capture_warnings.sh ${CMAKE_BINARY_DIR}")
+  SET_DIRECTORY_PROPERTIES(PROPERTY ADDITIONAL_MAKE_CLEAN_FILES
+    "${CMAKE_BINARY_DIR}/compile.warnings")
+  ADD_CUSTOM_TARGET(REMOVE_WARNINGS_FILE ALL
+    COMMAND rm -f "compile.warnings"
+    WORKING_DIRECTORY ${CMAKE_BINARY_DIR})
+  ADD_CUSTOM_TARGET(REPRINT ALL
+    COMMAND if [ -f "compile.warnings" ]; then cat "compile.warnings" \; fi
+    DEPENDS mysql udf_example explain_filename-t REMOVE_WARNINGS_FILE
+    WORKING_DIRECTORY "${CMAKE_BINARY_DIR}")
+ENDIF()