For calling some C functions, you need to link with a specific
OS-level library that contains that function. E.g., the sin
function requires linking a special library by using the command line
switch -lm. In our C iterface you do the equivalent thing by
calling add-lib as follows:
clear-libs s" m" add-lib \c #include <math.h> c-function sin sin r -- r
First, you clear any libraries that may have been declared earlier
(you don’t need them for sin); then you add the m
library (actually libm.so or somesuch) to the currently
declared libraries; you can add as many as you need. Finally you
declare the function as shown above. Typically you will use the same
set of library declarations for many function declarations; you need
to write only one set for that, right at the beginning.
Note that you must not call clear-libs inside
c-library...end-c-library; however, c-library performs
the function of clear-libs, so clear-libs is not
necessary, and you usually want to put add-lib calls inside
c-library...end-c-library.
clear-libs ( – ) gforth-0.7 “clear-libs”
Clear the list of libs
add-lib ( c-addr u – ) gforth-0.7 “add-lib”
Add library libstring to the list of libraries, where string is represented by c-addr u.
add-libpath ( c-addr u – ) gforth-0.7 “add-libpath”
Add path string to the list of library search pathes, where string is represented by c-addr u.
add-framework ( c-addr u – ) gforth-1.0 “add-framework”
Add framework libstring to the list of frameworks, where string is represented by c-addr u.
add-incdir ( c-addr u – ) gforth-1.0 “add-incdir”
Add path c-addr u to the list of include search pathes
add-cflags ( c-addr u – ) gforth-1.0 “add-cflags”
add any kind of cflags to compilation
add-ldflags ( c-addr u – ) gforth-1.0 “add-ldflags”
add flag to linker