dnl handle various error-related things

dnl Thomas Vander Stichele <thomas@apestaart.org>

dnl Tim-Philipp Müller <tim centricular net>

dnl Last modification: 2008-02-18

dnl AG_GST_SET_ERROR_CFLAGS([ADD-WERROR], [MORE_FLAGS])

dnl AG_GST_SET_ERROR_CXXFLAGS([ADD-WERROR], [MORE_FLAGS])

dnl AG_GST_SET_LEVEL_DEFAULT([IS-GIT-VERSION])

dnl Sets WARNING_CFLAGS and ERROR_CFLAGS to something the compiler 

dnl will accept and AC_SUBST them so they are available in Makefile

dnl

dnl WARNING_CFLAGS will contain flags to make the compiler emit more

dnl   warnings.

dnl ERROR_CFLAGS will contain flags to make those warnings fatal,

dnl   unless ADD-WERROR is set to "no"

dnl 

dnl If MORE_FLAGS is set, tries to add each of the given flags

dnl to WARNING_CFLAGS if the compiler supports them. Each flag is 

dnl tested separately.

dnl

dnl These flags can be overridden at make time:

dnl make ERROR_CFLAGS=

AC_DEFUN([AG_GST_SET_ERROR_CFLAGS],

[

  AC_REQUIRE([AC_PROG_CC])

  AC_REQUIRE([AS_COMPILER_FLAG])

  WARNING_CFLAGS=""

  ERROR_CFLAGS=""

  dnl if we support -Wall, set it unconditionally

  AS_COMPILER_FLAG(-Wall,

                   WARNING_CFLAGS="$WARNING_CFLAGS -Wall")

  dnl Warn if declarations after statements are used (C99 extension)

  AS_COMPILER_FLAG(-Wdeclaration-after-statement,

        WARNING_CFLAGS="$WARNING_CFLAGS -Wdeclaration-after-statement")

  dnl Warn if variable length arrays are used (C99 extension)

  AS_COMPILER_FLAG(-Wvla,

        WARNING_CFLAGS="$WARNING_CFLAGS -Wvla")

  dnl Warn for invalid pointer arithmetic

  AS_COMPILER_FLAG(-Wpointer-arith,

        WARNING_CFLAGS="$WARNING_CFLAGS -Wpointer-arith")

  dnl if asked for, add -Werror if supported

  if test "x$1" != "xno"

  then

    AS_COMPILER_FLAG(-Werror, ERROR_CFLAGS="$ERROR_CFLAGS -Werror")

  fi

  if test "x$2" != "x"

  then

    UNSUPPORTED=""

    list="$2"

    for each in $list

    do

      AS_COMPILER_FLAG($each,

          WARNING_CFLAGS="$WARNING_CFLAGS $each",

          UNSUPPORTED="$UNSUPPORTED $each")

    done

    if test "X$UNSUPPORTED" != X ; then

      AC_MSG_NOTICE([unsupported compiler flags: $UNSUPPORTED])

    fi

  fi

  AC_SUBST(WARNING_CFLAGS)

  AC_SUBST(ERROR_CFLAGS)

  AC_MSG_NOTICE([set WARNING_CFLAGS to $WARNING_CFLAGS])

  AC_MSG_NOTICE([set ERROR_CFLAGS to $ERROR_CFLAGS])

])

dnl Sets WARNING_CXXFLAGS and ERROR_CXXFLAGS to something the compiler 

dnl will accept and AC_SUBST them so they are available in Makefile

dnl

dnl WARNING_CXXFLAGS will contain flags to make the compiler emit more

dnl   warnings.

dnl ERROR_CXXFLAGS will contain flags to make those warnings fatal,

dnl   unless ADD-WERROR is set to "no"

dnl 

dnl If MORE_FLAGS is set, tries to add each of the given flags

dnl to WARNING_CFLAGS if the compiler supports them. Each flag is 

dnl tested separately.

dnl

dnl These flags can be overridden at make time:

dnl make ERROR_CXXFLAGS=

AC_DEFUN([AG_GST_SET_ERROR_CXXFLAGS],

[

  AC_REQUIRE([AC_PROG_CXX])

  AC_REQUIRE([AS_CXX_COMPILER_FLAG])

  ERROR_CXXFLAGS=""

  WARNING_CXXFLAGS=""

  dnl if we support -Wall, set it unconditionally

  AS_CXX_COMPILER_FLAG(-Wall, WARNING_CXXFLAGS="$WARNING_CXXFLAGS -Wall")

  dnl if asked for, add -Werror if supported

  if test "x$1" != "xno"

  then

    AS_CXX_COMPILER_FLAG(-Werror, ERROR_CXXFLAGS="$ERROR_CXXFLAGS -Werror")

    if test "x$ERROR_CXXFLAGS" != "x"

    then

        dnl add exceptions

        AS_CXX_COMPILER_FLAG([-Wno-non-virtual-dtor], ERROR_CXXFLAGS="$ERROR_CXXFLAGS -Wno-non-virtual-dtor")

	dnl Add -fno-strict-aliasing for GLib versions before 2.19.8

	dnl as before G_LOCK and friends caused strict aliasing compiler

	dnl warnings.

	PKG_CHECK_EXISTS([glib-2.0 < 2.19.8], [

	  AS_CXX_COMPILER_FLAG([-fno-strict-aliasing],

	    ERROR_CXXFLAGS="$ERROR_CXXFLAGS -fno-strict-aliasing")

	  ])

    fi

  fi

  if test "x$2" != "x"

  then

    UNSUPPORTED=""

    list="$2"

    for each in $list

    do

      AS_CXX_COMPILER_FLAG($each,

          WARNING_CXXFLAGS="$WARNING_CXXFLAGS $each",

          UNSUPPORTED="$UNSUPPORTED $each")

    done

    if test "X$UNSUPPORTED" != X ; then

      AC_MSG_NOTICE([unsupported compiler flags: $UNSUPPORTED])

    fi

  fi

  AC_SUBST(WARNING_CXXFLAGS)

  AC_SUBST(ERROR_CXXFLAGS)

  AC_MSG_NOTICE([set WARNING_CXXFLAGS to $WARNING_CXXFLAGS])

  AC_MSG_NOTICE([set ERROR_CXXFLAGS to $ERROR_CXXFLAGS])

])

dnl Sets WARNING_OBJCFLAGS and ERROR_OBJCFLAGS to something the compiler 

dnl will accept and AC_SUBST them so they are available in Makefile

dnl

dnl WARNING_OBJCFLAGS will contain flags to make the compiler emit more

dnl   warnings.

dnl ERROR_OBJCFLAGS will contain flags to make those warnings fatal,

dnl   unless ADD-WERROR is set to "no"

dnl 

dnl If MORE_FLAGS is set, tries to add each of the given flags

dnl to WARNING_CFLAGS if the compiler supports them. Each flag is 

dnl tested separately.

dnl

dnl These flags can be overridden at make time:

dnl make ERROR_OBJCFLAGS=

AC_DEFUN([AG_GST_SET_ERROR_OBJCFLAGS],

[

  AC_REQUIRE([AC_PROG_OBJC])

  AC_REQUIRE([AS_OBJC_COMPILER_FLAG])

  ERROR_OBJCFLAGS=""

  WARNING_OBJCFLAGS=""

  dnl if we support -Wall, set it unconditionally

  AS_OBJC_COMPILER_FLAG(-Wall, WARNING_OBJCFLAGS="$WARNING_OBJCFLAGS -Wall")

  dnl if asked for, add -Werror if supported

  if test "x$1" != "xno"

  then

    AS_OBJC_COMPILER_FLAG(-Werror, ERROR_OBJCFLAGS="$ERROR_OBJCFLAGS -Werror")

    if test "x$ERROR_OBJCFLAGS" != "x"

    then

	dnl Add -fno-strict-aliasing for GLib versions before 2.19.8

	dnl as before G_LOCK and friends caused strict aliasing compiler

	dnl warnings.

	PKG_CHECK_EXISTS([glib-2.0 < 2.19.8], [

	  AS_OBJC_COMPILER_FLAG([-fno-strict-aliasing],

	    ERROR_OBJCFLAGS="$ERROR_OBJCFLAGS -fno-strict-aliasing")

	  ])

    fi

  fi

  if test "x$2" != "x"

  then

    UNSUPPORTED=""

    list="$2"

    for each in $list

    do

      AS_OBJC_COMPILER_FLAG($each,

          WARNING_OBJCFLAGS="$WARNING_OBJCFLAGS $each",

          UNSUPPORTED="$UNSUPPORTED $each")

    done

    if test "X$UNSUPPORTED" != X ; then

      AC_MSG_NOTICE([unsupported compiler flags: $UNSUPPORTED])

    fi

  fi

  AC_SUBST(WARNING_OBJCFLAGS)

  AC_SUBST(ERROR_OBJCFLAGS)

  AC_MSG_NOTICE([set WARNING_OBJCFLAGS to $WARNING_OBJCFLAGS])

  AC_MSG_NOTICE([set ERROR_OBJCFLAGS to $ERROR_OBJCFLAGS])

])

dnl Sets the default error level for debugging messages

AC_DEFUN([AG_GST_SET_LEVEL_DEFAULT],

[

  dnl define correct errorlevel for debugging messages. We want to have

  dnl GST_ERROR messages printed when running cvs builds

  if test "x[$1]" = "xyes"; then

    GST_LEVEL_DEFAULT=GST_LEVEL_ERROR

  else

    GST_LEVEL_DEFAULT=GST_LEVEL_NONE

  fi

  AC_DEFINE_UNQUOTED(GST_LEVEL_DEFAULT, $GST_LEVEL_DEFAULT,

    [Default errorlevel to use])

  dnl AC_SUBST so we can use it for win32/common/config.h

  AC_SUBST(GST_LEVEL_DEFAULT)

])