<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> </head> <body> <div class="moz-cite-prefix">On 11/7/21 21:43, Juan Vuletich wrote: </div> <blockquote type="cite" cite="mid:61883A61.8050109@jvuletich.org"> <meta content="text/html; charset=UTF-8" http-equiv="Content-Type"> On 11/6/2021 3:01 PM, Nicola Mingotti via Cuis-dev wrote: <blockquote cite="mid:66440e94-1015-d445-2e74-19a2ed47180c@gmail.com" type="cite"> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> Hi guys, I was trying to develop my first FFI calls in Cuis today but I am stuck, i hope some of you can give me some guidance. In the attached package there are implemented 2 foreign functions TestClass (class) >> time # working TestClass (class) >> localtime # broken ---- interactions ---------- TestClass time. " ok " TestClass localtime2: (TestClass time). " broken " ----------------------------- The error i get is "can not use integer as pointer". Any ideas ? bye Nicola </blockquote> The C declaration says argument is a pointer, but you are passing an integer. If you want a pointer, you need to set up a byte array with the correct bytes, and pass that. The FFI will pass the pointer. There are several packages using FFI you can use as examples of working code. I'm pretty sure there is a lot of documentation on Squeak / Cuis FFI if you google a bit. As general advice, I'd say that if you really need FFI, it is best to spend the time in reading about it and playing with existing code. You'll have to spend at least several hours on that. But if you can live in the the happy Smalltalk land instead, it is of course easier. Also, depending on your needs, and the availability of time to spend on this, you might prefer a VM plugin: It builds the C stack for you. HTH, <pre class="moz-signature" cols="72">-- Juan Vuletich <a class="moz-txt-link-abbreviated" href="http://www.cuis-smalltalk.org" moz-do-not-send="true">www.cuis-smalltalk.org</a> <a class="moz-txt-link-freetext" href="https://github.com/Cuis-Smalltalk/Cuis-Smalltalk-Dev" moz-do-not-send="true">https://github.com/Cuis-Smalltalk/Cuis-Smalltalk-Dev</a> <a class="moz-txt-link-freetext" href="https://github.com/jvuletich" moz-do-not-send="true">https://github.com/jvuletich</a> <a class="moz-txt-link-freetext" href="https://www.linkedin.com/in/juan-vuletich-75611b3" moz-do-not-send="true">https://www.linkedin.com/in/juan-vuletich-75611b3</a> @JuanVuletich</pre> </blockquote> Hi Juan, thank you! I will try as soon as possible. I tried to read all what i could find about Squeak and Cuis, also a little bit on Pharo. With that was able to get started, but then, just a little problem like this could put me in the angle. As next step I will try to dig more into existing Squeak/Cuis FFI examples. I red about the VM plugin option, that seems more challenging, so i though i would be better to investigate first the FFI. Sooner or later I will need to invest some time to understand also the plugins. Anyway, when will be able to master the technique i will make docs/video so that it will be less difficult for future users. Bye Nicola </body> </html>