6.4 Running the Compiler
To check for a syntax feature of the current language's (see Language Choice) compiler, such as whether it recognizes a certain keyword, or
simply to try some library feature, use
AC_COMPILE_IFELSE to try
to compile a small program that uses that feature.
— Macro: AC_COMPILE_IFELSE
(input, [action-if-true], [action-if-false]
Run the compiler and compilation flags of the current language
(see Language Choice) on the input, run the shell commands
action-if-true on success, action-if-false otherwise. The
input can be made by
AC_LANG_PROGRAM and friends.
It is customary to report unexpected failures with
AC_MSG_FAILURE. This macro does not try to link; use
AC_LINK_IFELSE if you need to do that (see Running the Linker).
For tests in Erlang, the input must be the source code of a module named
AC_COMPILE_IFELSE generates a conftest.beam
file that can be interpreted by the Erlang virtual machine (
ERL). It is
recommended to use
AC_LANG_PROGRAM to specify the test program, to ensure
that the Erlang module has the right name.