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[UFFI] How to get a string from the a void pointer

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kilon.alios

[UFFI] How to get a string from the a void pointer

So I managed to port all C++ functions to pharo, which basically includes the following

Not full definition of function

open()

lseek()

close()

mmap()

I have tested them all, they all return proper values from inside Pharo and Pharo does not crash.

it seems also that mmap works because it returns a void pointer as it should. This pointer points to the shared memory where I have put the string "hello" from another C++ program that has shared the memory .

So how can from Pharo take the void pointer

"(void*)@ 16rFFFFFFFF"

and retrieve the string "hello" that it points to ?

Essentially I want to dereference the pointer

I tried to send the message fromCString to the void pointer (ExternalData) but it crashed Pharo.

Another question, is it possible to cast a pointer ? (I do this with C++ programm)

so can I cast from pharo the void pointer to a string pointer ?

I have also no idea if the void pointer points to a proper memory address , the documentation says that all pointers live in head but I have no way to confirm this.

I am so close to sharing memory between Pharo and C++ that I can smell it :D

kilon.alios

Re: [UFFI] How to get a string from the a void pointer

AT LAST !!!! I DID IT!!!

The problem was that I was not storing a crucial value for an instance variable , so the void pointer was wrong. Corrected and I can see now the "hello" string inside Pharo :)

Now I can exchange data between C++ and Pharo and use that to call C++ functions/methods inside a C++ executable from Pharo. Unreal and Pharo can now become a reality.

Huge thank you for Esteban and UFFI, awesome :D

UFFI is far easier than I expected , but still I would like some more information for how to dereference pointer .

On Mon, Nov 7, 2016 at 10:30 PM Dimitris Chloupis <[hidden email]> wrote:

So I managed to port all C++ functions to pharo, which basically includes the following

Not full definition of function

open()
lseek()
close()
mmap()

I have tested them all, they all return proper values from inside Pharo and Pharo does not crash.

it seems also that mmap works because it returns a void pointer as it should. This pointer points to the shared memory where I have put the string "hello" from another C++ program that has shared the memory .

So how can from Pharo take the void pointer

"(void*)@ 16rFFFFFFFF"

and retrieve the string "hello" that it points to ?

Essentially I want to dereference the pointer

I tried to send the message fromCString to the void pointer (ExternalData) but it crashed Pharo.

Another question, is it possible to cast a pointer ? (I do this with C++ programm)
so can I cast from pharo the void pointer to a string pointer ?

I have also no idea if the void pointer points to a proper memory address , the documentation says that all pointers live in head but I have no way to confirm this.

I am so close to sharing memory between Pharo and C++ that I can smell it :D