dnl Macro to add --enable-coverage option (disabled by default) and add

dnl appropriate compiler flags to permit usage of gcov if that option is

dnl enabled.  If WRAPPER_xFLAGS variables are set then the flags will also be

dnl added to those variables.

dnl

dnl Sets "pac_cv_use_coverage=yes" and AC_DEFINEs USE_COVERAGE if coverage was

dnl successfully enabled.  Also creates an AM_CONDITIONAL with the name

dnl "BUILD_COVERAGE" that is true iff pac_cv_use_coverage=yes.

dnl

dnl Usage: PAC_CONFIG_SUBDIR_ARGS

dnl

dnl Assumes that all of the compiler macros have already been invoked

dnl (AC_PROG_CC and friends).

AC_DEFUN([PAC_ENABLE_COVERAGE],[

AC_ARG_VAR([GCOV],[name/path for the gcov utility])

AC_CHECK_PROGS([GCOV],[gcov])

AC_ARG_ENABLE([coverage],

              [AC_HELP_STRING([--enable-coverage],

                              [Turn on coverage analysis using gcc and gcov])],

              [],[enable_coverage=no])

if test "$enable_coverage" = "yes" ; then

    if test "$ac_cv_prog_gcc" = "yes" ; then

        CFLAGS="$CFLAGS -fprofile-arcs -ftest-coverage"

        LIBS="$LIBS -lgcov"

        if test ${WRAPPER_CFLAGS+set} = set ; then

            WRAPPER_CFLAGS="$WRAPPER_CFLAGS -fprofile-arcs -ftest-coverage"

        fi

    else

        AC_MSG_WARN([--enable-coverage only supported for GCC])

    fi

    if test "$enable_cxx" = "yes" ; then

        if test "$ac_cv_cxx_compiler_gnu" = "yes" ; then

            CXXFLAGS="$CXXFLAGS -fprofile-arcs -ftest-coverage"

            LIBS="$LIBS -lgcov"

            if test ${WRAPPER_CXXFLAGS+set} = set ; then

                WRAPPER_CXXFLAGS="$WRAPPER_CXXFLAGS -fprofile-arcs -ftest-coverage"

            fi

        else

            AC_MSG_WARN([--enable-coverage only supported for GCC])

        fi

    fi

    # Add similar options for g77 so that the Fortran tests will also

    # 

    if test "$enable_f77" = yes ; then

        if test "$ac_cv_f77_compiler_gnu" = "yes" ; then

             FFLAGS="$FFLAGS -fprofile-arcs -ftest-coverage"

             LIBS="$LIBS -lgcov"

             if test ${WRAPPER_FFLAGS+set} = set ; then

                 WRAPPER_FFLAGS="$WRAPPER_FFLAGS -fprofile-arcs -ftest-coverage"

             fi

        else

            AC_MSG_WARN([--enable-coverage only supported for G77/GFORTRAN])

        fi

    fi

    if test "$enable_fc" = yes ; then

        if test "$ac_cv_fc_compiler_gnu" = "yes" ; then

             FCFLAGS="$FCFLAGS -fprofile-arcs -ftest-coverage"

             LIBS="$LIBS -lgcov"

             if test ${WRAPPER_FCFLAGS+set} = set ; then

                 WRAPPER_FCFLAGS="$WRAPPER_FCFLAGS -fprofile-arcs -ftest-coverage"

             fi

        else

            AC_MSG_WARN([--enable-coverage only supported for GFORTRAN])

        fi

    fi

    # On some platforms (e.g., Mac Darwin), we must also *link* 

    # with the -fprofile-args -ftest-coverage option.

    AC_MSG_CHECKING([whether compilation with coverage analysis enabled works])

    AC_LINK_IFELSE([AC_LANG_SOURCE([int main(int argc, char **argv){return 1;}])],

                   [AC_MSG_RESULT([yes])],

                   [AC_MSG_RESULT([no])

                    AC_MSG_ERROR([Unable to link programs when coverage analysis enabled])])

    # Test for the routines that we need to use to ensure that the

    # data files are (usually) written out

    # FIXME: Some versions of Linux provide usleep, but it rounds times

    # up to the next second (!)

    AC_CHECK_FUNCS([usleep])

    # NOTE: using a "pac_cv_" prefix but not caching because of xFLAGS "side effects"

    pac_cv_use_coverage=yes

    AC_DEFINE([USE_COVERAGE],[1],[Define if performing coverage tests])

fi

AM_CONDITIONAL([BUILD_COVERAGE],[test "X$pac_cv_use_coverage" = "Xyes"])

])