Packages that use both C and C++ need to test features of both
compilers. Autoconf-generated configure
scripts check for C
features by default. The following macros determine which language's
compiler is used in tests that follow in `configure.in'.
CC
and CPP
and use extension
`.c' for test programs.
CXX
and CXXCPP
and use
extension `.C' for test programs.
AC_LANG_C
or
AC_LANG_CPLUSPLUS
) on a stack. Does not change which language is
current. Use this macro and AC_LANG_RESTORE
in macros that need
to temporarily switch to a particular language.
AC_LANG_SAVE
, and remove it from the stack. This macro is
equivalent to either AC_LANG_C
or AC_LANG_CPLUSPLUS
,
whichever had been run most recently when AC_LANG_SAVE
was last
called.
Do not call this macro more times than AC_LANG_SAVE
.
AC_REQUIRE
(see section Prerequisite Macros) with an
argument of either AC_PROG_CPP
or AC_PROG_CXXCPP
,
depending on which language is current.