ac_prog_cc_for_build

This macro searches for a C compiler that generates native executables, that is a C compiler that surely is not a cross-compiler. This can be useful if you have to generate source code at compile-time like for example GCC does.

The macro sets the CC_FOR_BUILD and CPP_FOR_BUILD macros to anything needed to compile or link (CC_FOR_BUILD) and preprocess (CPP_FOR_BUILD). The value of these variables can be overridden by the user by specifying a compiler with an environment variable (like you do for standard CC).

It also sets BUILD_EXEEXT and BUILD_OBJEXT to the executable and object file extensions for the build platform, and GCC_FOR_BUILD to `yes' if the compiler we found is GCC. All these variables but GCC_FOR_BUILD are substituted in the Makefile.

AC_DEFUN([AC_PROG_CC_FOR_BUILD], [dnl
AC_REQUIRE([AC_PROG_CC])dnl
AC_REQUIRE([AC_PROG_CPP])dnl
AC_REQUIRE([AC_EXEEXT])dnl
AC_REQUIRE([AC_CANONICAL_SYSTEM])dnl
dnl
pushdef([AC_TRY_COMPILER], [
cat > conftest.$ac_ext << EOF
#line __oline__ "configure"
#include "confdefs.h"
[$1]
EOF
# If we can't run a trivial program, we are probably using a cross
compiler.
# Fail miserably.
if AC_TRY_EVAL(ac_link) && test -s conftest${ac_exeext} && (./conftest;
exit) 2>/dev/null; then
  [$2]=yes
else
  echo "configure: failed program was:" >&AC_FD_CC
  cat conftest.$ac_ext >&AC_FD_CC
  [$2]=no
fi
[$3]=no
rm -fr conftest*])dnl

dnl Use the standard macros, but make them use other variable names
dnl
pushdef([cross_compiling], [#])dnl
pushdef([ac_cv_prog_CPP], ac_cv_build_prog_CPP)dnl
pushdef([ac_cv_prog_gcc], ac_cv_build_prog_gcc)dnl
pushdef([ac_cv_prog_cc_works], ac_cv_build_prog_cc_works)dnl
pushdef([ac_cv_prog_cc_cross], ac_cv_build_prog_cc_cross)dnl
pushdef([ac_cv_prog_cc_g], ac_cv_build_prog_cc_g)dnl
pushdef([ac_cv_exeext], ac_cv_build_exeext)dnl
pushdef([ac_cv_objext], ac_cv_build_objext)dnl
pushdef([ac_exeext], ac_build_exeext)dnl
pushdef([ac_objext], ac_build_objext)dnl
pushdef([CC], CC_FOR_BUILD)dnl
pushdef([CPP], CPP_FOR_BUILD)dnl
pushdef([CFLAGS], CFLAGS_FOR_BUILD)dnl
pushdef([CPPFLAGS], CPPFLAGS_FOR_BUILD)dnl
pushdef([host], build)dnl
pushdef([host_alias], build_alias)dnl
pushdef([host_cpu], build_cpu)dnl
pushdef([host_vendor], build_vendor)dnl
pushdef([host_os], build_os)dnl
pushdef([ac_cv_host], ac_cv_build)dnl
pushdef([ac_cv_host_alias], ac_cv_build_alias)dnl
pushdef([ac_cv_host_cpu], ac_cv_build_cpu)dnl
pushdef([ac_cv_host_vendor], ac_cv_build_vendor)dnl
pushdef([ac_cv_host_os], ac_cv_build_os)dnl
pushdef([ac_cpp], ac_build_cpp)dnl
pushdef([ac_compile], ac_build_compile)dnl
pushdef([ac_link], ac_build_link)dnl

dnl Defeat the anti-duplication mechanism
dnl
undefine([AC_PROVIDE_AC_PROG_CPP])dnl
undefine([AC_PROVIDE_AC_PROG_C])dnl
undefine([AC_PROVIDE_AC_EXEEXT])dnl

AC_PROG_CC
AC_PROG_CPP
AC_EXEEXT

dnl Restore the old definitions
dnl
popdef([AC_TRY_COMPILER])dnl
popdef([ac_link])dnl
popdef([ac_compile])dnl
popdef([ac_cpp])dnl
popdef([ac_cv_host_os])dnl
popdef([ac_cv_host_vendor])dnl
popdef([ac_cv_host_cpu])dnl
popdef([ac_cv_host_alias])dnl
popdef([ac_cv_host])dnl
popdef([host_os])dnl
popdef([host_vendor])dnl
popdef([host_cpu])dnl
popdef([host_alias])dnl
popdef([host])dnl
popdef([CPPFLAGS])dnl
popdef([CFLAGS])dnl
popdef([CPP])dnl
popdef([CC])dnl
popdef([ac_objext])dnl
popdef([ac_exeext])dnl
popdef([ac_cv_objext])dnl
popdef([ac_cv_exeext])dnl
popdef([ac_cv_prog_cc_g])dnl
popdef([ac_cv_prog_cc_works])dnl
popdef([ac_cv_prog_cc_cross])dnl
popdef([ac_cv_prog_gcc])dnl
popdef([ac_cv_prog_cc])dnl
popdef([cross_compiling])dnl

dnl Finally, set Makefile variables
dnl
BUILD_EXEEXT=$ac_build_exeext
BUILD_OBJEXT=$ac_build_objext
AC_SUBST(BUILD_EXEEXT)dnl
AC_SUBST(BUILD_OBJEXT)dnl
AC_SUBST([CFLAGS_FOR_BUILD])dnl
AC_SUBST([CPPFLAGS_FOR_BUILD])dnl
])