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AX_GCC_OPTION(OPTION,EXTRA-OPTIONS,TEST-PROGRAM,ACTION-IF-SUCCESSFUL,ACTION-IF-NOT-SUCCESFUL)
AX_GCC_OPTION checks wheter gcc accepts the passed OPTION. If it accepts the OPTION then ACTION-IF-SUCCESSFUL will be executed, otherwise ACTION-IF-UNSUCCESSFUL.
NOTE: This macro will be obsoleted by AX_C_CHECK_FLAG AX_CXX_CHECK_FLAG, AX_CPP_CHECK_FLAG, AX_CXXCPP_CHECK_FLAG and AX_LD_CHECK_FLAG.
A typical usage should be the following one:
AX_GCC_OPTION([-fomit-frame-pointer],[],[],[ AC_MSG_NOTICE([The option is supported])],[ AC_MSG_NOTICE([No luck this time]) ])
The macro doesn't discriminate between languages so, if you are testing for an option that works for C++ but not for C you should use '-x c++' as EXTRA-OPTIONS:
AX_GCC_OPTION([-fno-rtti],[-x c++],[],[ ... ],[ ... ])
OPTION is tested against the following code:
int main() { return 0; }
The optional TEST-PROGRAM comes handy when the default main() is not suited for the option being checked
So, if you need to test for -fstrict-prototypes option you should probably use the macro as follows:
AX_GCC_OPTION([-fstrict-prototypes],[-x c++],[ int main(int argc, char ** argv) { (void) argc; (void) argv; return 0; } ],[ ... ],[ ... ])
Note that the macro compiles but doesn't link the test program so it is not suited for checking options that are passed to the linker, like:
-Wl,-L<a-library-path>
In order to avoid such kind of problems you should think about usinguse the AX_*_CHECK_FLAG family macros
http://autoconf-archive.cryp.to/ax_gcc_option.m4
Copyright © 2008 Francesco Salvestrini
<salvestrini@users.sourceforge.net>
Copyright © 2008 Bogdan Drozdowski <bogdandr@op.pl>
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