Switched off Maintainer mode by default as it gave wrong compiler warnings (as it added -Wall after some switches was already turned off)

cmake/maintainer.cmake:
  Add -DFORCE_INIT_OF_VARS to not get warnings generated by -Wall
configure.cmake:
  Don't add -Wall if we already have it. This is to not enable options that are already turned off.
support-files/compiler_warnings.supp:
  Removed suppression that is not needed anymore

CMakeLists.txt

@@ -105,7 +105,7 @@ ENDIF()
 #
 INCLUDE(maintainer)
 
-SET(MYSQL_MAINTAINER_MODE "AUTO" CACHE STRING "MySQL maintainer-specific development environment. Options are: ON OFF AUTO.")
+SET(MYSQL_MAINTAINER_MODE "OFF" CACHE STRING "MySQL maintainer-specific development environment. Options are: ON OFF AUTO.")
 MARK_AS_ADVANCED(MYSQL_MAINTAINER_MODE)
 
 # Whether the maintainer mode compiler options should be enabled.
@@ -261,16 +261,18 @@ MYSQL_CHECK_SSL()
 MYSQL_CHECK_READLINE()
 
 #
-# Setup maintainer mode options by the end. Platform checks are
+# Setup maintainer mode options. Platform checks are
 # not run with the warning options as to not perturb fragile checks
 # (i.e. do not make warnings into errors).
+# We have to add MAINTAINER_C_WARNINGS first to ensure that the flags
+# given by the invoking user are honored
 #
 IF(MYSQL_MAINTAINER_MODE MATCHES "ON")
-  SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${MY_MAINTAINER_C_WARNINGS}")
-  SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${MY_MAINTAINER_CXX_WARNINGS}")
+  SET(CMAKE_C_FLAGS "${MY_MAINTAINER_C_WARNINGS} ${CMAKE_C_FLAGS}")
+  SET(CMAKE_CXX_FLAGS "${MY_MAINTAINER_CXX_WARNINGS} ${CMAKE_CXX_FLAGS}")
 ELSEIF(MYSQL_MAINTAINER_MODE MATCHES "AUTO")
-  SET(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} ${MY_MAINTAINER_C_WARNINGS}")
-  SET(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} ${MY_MAINTAINER_CXX_WARNINGS}")
+  SET(CMAKE_C_FLAGS_DEBUG "${MY_MAINTAINER_C_WARNINGS} ${CMAKE_C_FLAGS_DEBUG}")
+  SET(CMAKE_CXX_FLAGS_DEBUG "${MY_MAINTAINER_CXX_WARNINGS} ${CMAKE_CXX_FLAGS_DEBUG}")
 ENDIF()
 
 IF(WITH_UNIT_TESTS)

cmake/maintainer.cmake

@@ -18,7 +18,7 @@ INCLUDE(CheckCCompilerFlag)
 # Setup GCC (GNU C compiler) warning options.
 MACRO(SET_MYSQL_MAINTAINER_GNU_C_OPTIONS)
   SET(MY_MAINTAINER_WARNINGS
-      "-Wall -Wextra -Wunused -Wwrite-strings -Wno-strict-aliasing")
+      "-Wall -Wextra -Wunused -Wwrite-strings -Wno-strict-aliasing -DFORCE_INIT_OF_VARS")
 
   CHECK_C_COMPILER_FLAG("-Wno-missing-field-initializers"
     HAVE_NO_MISSING_FIELD_INITIALIZERS)

configure.cmake

@@ -55,10 +55,10 @@ ENDIF()
 
 
 # Always enable -Wall for gnu C/C++
-IF(CMAKE_COMPILER_IS_GNUCXX)
+IF(CMAKE_COMPILER_IS_GNUCXX AND NOT CMAKE_CXX_FLAGS MATCHES ".*-Wall.*")
   SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wno-unused-parameter")
 ENDIF()
-IF(CMAKE_COMPILER_IS_GNUCC)
+IF(CMAKE_COMPILER_IS_GNUCC AND NOT CMAKE_C_FLAGS MATCHES ".*-Wall.*")
   SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall")
 ENDIF()
 

support-files/compiler_warnings.supp

@@ -129,10 +129,6 @@ signal\.c : .*unused parameter.*
 # Aria warning that is ok in debug builds
 #
 storage/maria/ma_pagecache.c: .*'info_check_pin' defined but not used
-#
-# This warning is strange; We should not get it with -DFORCE_INIT_OF_VARS
-# I added the suprression as I was not able to remove this warning :(
-storage/maria/ma_check.c: may be used uninitialized in this function : 1200-1500
 
 #
 # Pbxt