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7.2 Autoconf Macros

GNU Guile provides a pkg-config description file, installed as prefix/lib/pkgconfig/guile-1.8.pc, which contains all the information necessary to compile and link C applications that use Guile. The pkg-config program is able to read this file and provide this information to application programmers; it can be obtained at http://pkg-config.freedesktop.org/.

The following command lines give respectively the C compilation and link flags needed to build Guile-using programs: 

     pkg-config guile-1.8 --cflags
     pkg-config guile-1.8 --libs

To ease use of pkg-config with Autoconf, pkg-config comes with a convenient Autoconf macro. The following example looks for Guile and sets the GUILE_CFLAGS and GUILE_LIBS variables accordingly, or prints an error and exits if Guile was not found: 

     PKG_CHECK_MODULES([GUILE], [guile-1.8])

Guile comes with additional Autoconf macros providing more information, installed as prefix/share/aclocal/guile.m4. Their names all begin with GUILE_.

— Autoconf Macro: GUILE_PROGS

This macro looks for programs guile, guile-config and guile-tools, and sets variables GUILE, GUILE_CONFIG and GUILE_TOOLS, to their paths, respectively. If either of the first two is not found, signal error.

The variables are marked for substitution, as by AC_SUBST.

— Autoconf Macro: GUILE_FLAGS

This macro runs the guile-config script, installed with Guile, to find out where Guile's header files and libraries are installed. It sets two variables, GUILE_CFLAGS and GUILE_LDFLAGS.

GUILE_CFLAGS: flags to pass to a C or C++ compiler to build code that uses Guile header files. This is almost always just a -I flag.

GUILE_LDFLAGS: flags to pass to the linker to link a program against Guile. This includes -lguile for the Guile library itself, any libraries that Guile itself requires (like -lqthreads), and so on. It may also include a -L flag to tell the compiler where to find the libraries.

The variables are marked for substitution, as by AC_SUBST.

— Autoconf Macro: GUILE_SITE_DIR

This looks for Guile's "site" directory, usually something like PREFIX/share/guile/site, and sets var GUILE_SITE to the path. Note that the var name is different from the macro name.

The variable is marked for substitution, as by AC_SUBST.

— Autoconf Macro: GUILE_CHECK_RETVAL var check

var is a shell variable name to be set to the return value. check is a Guile Scheme expression, evaluated with "$GUILE -c", and returning either 0 or non-#f to indicate the check passed. Non-0 number or #f indicates failure. Avoid using the character "#" since that confuses autoconf.

— Autoconf Macro: GUILE_MODULE_CHECK var module featuretest description

var is a shell variable name to be set to "yes" or "no". module is a list of symbols, like: (ice-9 common-list). featuretest is an expression acceptable to GUILE_CHECK, q.v. description is a present-tense verb phrase (passed to AC_MSG_CHECKING).

— Autoconf Macro: GUILE_MODULE_AVAILABLE var module

var is a shell variable name to be set to "yes" or "no". module is a list of symbols, like: (ice-9 common-list).

— Autoconf Macro: GUILE_MODULE_REQUIRED symlist

symlist is a list of symbols, WITHOUT surrounding parens, like: ice-9 common-list.

— Autoconf Macro: GUILE_MODULE_EXPORTS var module modvar

var is a shell variable to be set to "yes" or "no". module is a list of symbols, like: (ice-9 common-list). modvar is the Guile Scheme variable to check.

— Autoconf Macro: GUILE_MODULE_REQUIRED_EXPORT module modvar

module is a list of symbols, like: (ice-9 common-list). modvar is the Guile Scheme variable to check.