dnl xiph_compiler.m4

dnl $Id: xiph_compiler.m4 8320 2004-11-30 20:36:09Z karl $

dnl XIPH_FUNC_VA_COPY

dnl Karl Heyes

dnl

# XIPH_FUNC_VA_COPY

# Test for implementation of va_copy, or define appropriately if missing

AC_DEFUN([XIPH_FUNC_VA_COPY],

[dnl

AC_MSG_CHECKING([for va_copy])

AC_TRY_LINK([#include <stdarg.h>], [va_list ap1, ap2; va_copy(ap1, ap2);],

  AC_MSG_RESULT([va_copy]),

  [dnl

  AH_TEMPLATE([va_copy], [define if va_copy is not available])

  AC_TRY_LINK([#include <stdarg.h>], [va_list ap1, ap2; __va_copy(ap1, ap2);],

    [dnl

    AC_DEFINE([va_copy], [__va_copy])

    AC_MSG_RESULT([__va_copy])],

    [dnl

    AC_DEFINE([va_copy(dest,src)], [memcpy(&dest,&src,sizeof(va_list))])

    AC_MSG_RESULT([memcpy])

    ])

  ])

])

])dnl XIPH_FUNC_VA_COPY

dnl XIPH_C_ATTRIBUTE

dnl Karl Heyes

dnl

# XIPH_C_ATTRIBUTE

# Define __attribute__ to be empty if the compiler does not support it

AC_DEFUN([XIPH_C_ATTRIBUTE],

[dnl

AC_TRY_COMPILE([int func(void) __attribute__((unused));],

  [int x __attribute__ ((unused));],,[dnl

  AH_TEMPLATE([__attribute__],[Define to empty if __attribute__ is not supported])

  AC_DEFINE([__attribute__(x)],[])

])

])dnl XIPH_C_ATTRIBUTE

dnl XIPH_GCC_WARNING

dnl Karl Heyes

dnl

# XIPH_GCC_WARNING(flag, action-if-warning, action-if-not)

# Tests whether GCC emits a warning if explicitly asked to use flag.

# Useful for eg system default include paths

AC_DEFUN([XIPH_GCC_WARNING],

[AC_REQUIRE([AC_PROG_CC])

xt_warning=no

if test x"$GCC" = "xyes"

then

  save_cflags="$CFLAGS"

  CFLAGS="-Werror $1"

  AC_TRY_COMPILE(,,,xt_warning=yes)

  CFLAGS="$save_cflags"

fi

if test "$xt_warning" = "yes"

then

  ifelse([$2],,:,[$2])

else

  ifelse([$3],,:,[$3])

fi

])dnl XIPH_GCC_WARNING

dnl XIPH_CLEAN_CCFLAGS

dnl Brendan Cully <brendan@xiph.org> 20030612

dnl

# XIPH_CLEAN_CCFLAGS(flag-list, dest-shell-var-name)

# Filters out duplicate compiler flags, and -I flags if XIPH_GCC_WARNING

# complains about them

# Operates right-to-left on -l flags, left-to-right on everything else

# eg XIPH_CLEAN_CCFLAGS([-L/opt/lib -lfoo -lm -L/opt/lib -lbar -lm], [MY_LDFLAGS])

# => MY_LDFLAGS="-L/opt/lib -lfoo -lbar -lm"

# the cat<

AC_DEFUN([XIPH_CLEAN_CCFLAGS],

[AC_REQUIRE([AC_PROG_FGREP])

xt_FLAGS=''

for flag in $1

do

  case "$flag" in

  -l*)

    xt_FLAGS="$flag $xt_FLAGS"

    ;;

  *)

    if { cat <

 $xt_FLAGS x

EOF

} | $FGREP -v -e " $flag " > /dev/null

    then

      xt_FLAGS="$flag $xt_FLAGS"

    fi

    ;;

  esac

done

$2=''

for flag in $xt_FLAGS

do

  if { cat <

 $$2 x

EOF

} | $FGREP -v -e " $flag " > /dev/null

  then

    $2="$flag $$2"

  fi

done

# Prune -I flags if $CC warns about them

xt_FLAGS=''

for flag in $$2

do

  case "$flag" in

  -I*)

    XIPH_GCC_WARNING([$flag], [], [xt_FLAGS="$xt_FLAGS $flag"])

    ;;

  *)

    xt_FLAGS="$xt_FLAGS $flag"

    ;;

  esac

done

$2="$xt_FLAGS"

])dnl XIPH_CLEAN_CCFLAGS

dnl XIPH_VAR_APPEND

dnl Karl Heyes

dnl

# XIPH_VAR_APPEND(shell-var, list)

# Append each item in list to shell-var iff shell-var doesn't already have it

# eg XIPH_VAR_APPEND([CFLAGS], [-O2 -I/opt/packages/include])

AC_DEFUN([XIPH_VAR_APPEND],

[dnl

AC_REQUIRE([AC_PROG_FGREP])

for arg in $2

do

  if { cat <

 $$1 x

EOF

} | $FGREP -v -e " $arg " > /dev/null

  then

    $1="$$1 $arg"

  fi

done

])dnl XIPH_VAR_APPEND

dnl XIPH_VAR_PREPEND

dnl Karl Heyes

dnl

# XIPH_VAR_PREPEND(shell-var, list)

# see XIPH_VAR_APPEND

AC_DEFUN([XIPH_VAR_PREPEND],

[dnl

AC_REQUIRE([AC_PROG_FGREP])

xt_compare="$$1"

xt_filtered=""   

for arg in $2

do

  if { cat <

 $xt_compare x

EOF

} | $FGREP -v -e " $arg " > /dev/null

  then

    xt_compare="$arg $xt_compare"

    xt_filtered="$xt_filtered $arg"

  fi

done

$1="$xt_filtered $$1"

])dnl XIPH_VAR_PREPEND

dnl XIPH_C__FUNC__

dnl Karl Heyes <karl@xiph.org> 07/2004

AC_DEFUN([XIPH_C__FUNC__],

[dnl

AC_MSG_CHECKING([for __func__])

AC_COMPILE_IFELSE([AC_LANG_PROGRAM(,[const char *x = __func__;])],

    [ AC_MSG_RESULT([yes])],

    [ AH_TEMPLATE([__func__], [Replace __func__ if not supported])

    AC_COMPILE_IFELSE([AC_LANG_PROGRAM([],[const char *x = __FUNCTION__;])],

        [ AC_DEFINE([__func__],[__FUNCTION__])

        AC_MSG_RESULT([yes])],

        [ AC_DEFINE([__func__],[""])

        AC_MSG_RESULT([no])

        ])

    ])

])dnl XIPH_C__FUNC__