Calling C functions?

[ghost]

Something like this?

https://www.nongnu.org/gm2/11/interface_to_c.html

Is it possible? What's the syntax? I prefer writing by hand like I could do with gm2 instead of relying on demoitem's swig for cm3.

[demoitem]

To call C functions you use the EXTERNAL pragma

It can be used to reference an entire interface as in

<EXTERNAL> INTERFACE LLVM;

(* lots of declarations - all of which are external *)
END LLVM.

or to declare an individual external procedure, constant or variable as in

INTERFACE SomeInterface

<*EXTERNAL UnixName : C *> PROCEDURE LocalName(someparm : INTEGER) : BOOLEAN;
<*EXTERNAL ErrorNo *> VAR err : [0.255];
END SomeInterface.

The ":C" can be omitted and the system uses the default external language. (which is C the only language)

A call to SomeInterface.LocalName(99); for example will call UnixName in some library or object which is linked in.
Similarly for SomeInterface.err;

If the name in the EXTERNAL pragma is absent the local name use used.

[RodneyBates]

Also, you can use the declarations in m3-libs/m3core/src/C/Common/Ctypes.i3 for the parameter types. These are Modula-3 type declarations designed to be binary-identical to various types in C. They refer indirectly to other interfaces, in an effort to make them platform-independent, largely successfully, I believe. You can use them to refer to global variables as well.

…

On 9/8/22 09:22, peter mckinna wrote: To call C functions you use the EXTERNAL pragma It can be used to reference an entire interface as in </EXTERNAL/> INTERFACE LLVM; (* lots of declarations - all of which are external *) END LLVM. or to declare an individual external procedure, constant or variable as in INTERFACE SomeInterface <*EXTERNAL UnixName : C *> PROCEDURE LocalName(someparm : INTEGER) : BOOLEAN; <*EXTERNAL ErrorNo *> VAR err : [0.255]; END SomeInterface. The ":C" can be omitted and the system uses the default external language. (which is C the only language) A call to SomeInterface.LocalName(99); for example will call UnixName in some library or object which is linked in. Similarly for SomeInterface.err; If the name in the EXTERNAL pragma is absent the local name use used. — Reply to this email directly, view it on GitHub <#1059 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABSVZNFT6WE22OWI3O5E7YDV5HZBXANCNFSM6AAAAAAQGJ5MDQ>. You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[mikanystrom]

It's easy. Make an interface with pragma <*EXTERNAL*> Example https://github.com/modula3/cm3/blob/master/m3-libs/m3core/src/coroutine/UCONTEXT/ContextC.i3 Compare https://github.com/modula3/cm3/blob/master/m3-libs/m3core/src/coroutine/UCONTEXT/ContextC.c Mika

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On Wed, Sep 7, 2022, 3:08 AM pwd96m4a ***@***.***> wrote: Something like this? https://www.nongnu.org/gm2/11/interface_to_c.html Is it possible? What's the syntax? I prefer writing by hand like I could do with gm2 instead of relying on demoitem's swig for cm3. — Reply to this email directly, view it on GitHub <#1059>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABKYNJJSILI6G2YTOWNMMYTV47TKLANCNFSM6AAAAAAQGJ5MDQ> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>