embedding C code

[jassing]

With the C backend, is it possible to embed C code like you can with ASM?

[Demivec]

With the C backend, is it possible to embed C code like you can with ASM?

Yes.

[jassing]

OK, how do I pass a variable between PB and C?

[Demivec]

OK, how do I pass a variable between PB and C?

The same as described in the help file under 'Inline x86 ASM'.

https://www.purebasic.com/documentation/reference/inlinedasm.html

Here's an excerpt:

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- The used variables or pointers must be declared before to use them in an assembler keyword. Their names in assembler are 'v_variablename' and 'p_pointername', and in a procedure their names are 'p.v_variablename' and 'p.p_pointername'.
- Labels: The labels need to be referenced in lowercase when using the in-line ASM. When you reference a label, you must put the prefix 'l_' before the name.
If the label is defined in a procedure, then its prefix is 'll_procedurename_', in lowercase.
When you reference a module item, you must put the prefix 'module_name.l_' all in lowercase before the item.
If the label is defined in a procedure inside a module, then its prefix is 'module_name.ll_procedurename_', in lowercase.

[jassing]

The same as described in the help file under 'Inline x86 ASM'.

well that explains why I couldn't find it - I was searching for "C" in help, not asm.

thanks.

[idle]

inline c is useful but it's limited depending upon what your trying to do

take a look at the Raylib4 example in pbcex for instance, it facilitates you to use the library without importing the whole lib

viewtopic.php?t=79332

if you try to embed any c that has #include in it, pb adds it to the main {} which will lead to errors

[mk-soft]

Global vars was change from v_xxx to g_xxx

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Global iVal.i
Define lVal.l

!g_ival = 100;
!v_lval = 200;

Debug iVal
Debug lVal

Procedure foo(p1, p2)
  Protected r1
  ;r1 = p1 + p2
  !v_r1 = v_p1 + v_p2;
  ProcedureReturn r1
EndProcedure

iVal = foo(1, 2)
Debug iVal

Best way is is show "--commented" c-code

[idle]

Global vars was change from v_xxx to g_xxx

Code: Select all

Global iVal.i
Define lVal.l

!g_ival = 100;
!v_lval = 200;

Debug iVal
Debug lVal

Procedure foo(p1, p2)
  Protected r1
  ;r1 = p1 + p2
  !v_r1 = v_p1 + v_p2;
  ProcedureReturn r1
EndProcedure

iVal = foo(1, 2)
Debug iVal

Best way is is show "--commented" c-code

that will make things a bit harder, I was quite happily abusing it to get unsigned types and now it probably won't work.

[mk-soft]

Type conversion from signed to unsigned is also possible.

Code: Select all

Global iVal.i
Procedure foo(p1.l, p2.l)
  Protected r1
  ;r1 = p1 + p2
  !v_r1 = (unsigned long)((unsigned long)v_p1 + (unsigned long)v_p2);
  ProcedureReturn r1
EndProcedure

iVal = foo(1, -2)
Debug iVal

Or misunderstood what you mean

[idle]

That will work to, I was redefining a variable so it became unsigned and I haven't checked to see if it still works since the bug fix was done. 6.02

[jassing]

or just simply...

Code: Select all

t=-3 
! v_t = (unsigned int) v_t;

seems to work nicely...

[idle]

it still works

Code: Select all

Global a.l 
Global b.l 
!unsigned long g_a; 
a = -1 
b = -1 

Debug a 
Debug b 

[jassing]

Even simpler! how the obvious escapes us...

Of course,you could keep it one line to make it a little more 'together'

Code: Select all

Global a.l  : !unsigned long g_a; 

[jassing]

How do you access global variables declared inside a module?

This works as expected.

Code: Select all

Global myval1=4096
DeclareModule abc
  Declare test()
EndDeclareModule
Module abc
  Procedure test()
    ! int test1 = g_myval1;
  EndProcedure
EndModule
abc::test()

But I can't access a global var in a module...

Code: Select all

DeclareModule xyz
  Declare test()
EndDeclareModule
Module xyz
  Global myval2=1024
  Procedure test()
    ! int test2 = g_myval2; 
  EndProcedure
EndModule
xyz::test()

Somewhat related, this shouldn't work, right?

Code: Select all

Global myval1 = 2048
DeclareModule xyz
  Declare test()
EndDeclareModule
Module xyz
  Procedure test()
    Protected size
    !v_size = g_myval1;
    Debug size
  EndProcedure
EndModule
xyz::test()

Or this:

Code: Select all

Define myval1 = 2048
DeclareModule xyz
  Declare test()
EndDeclareModule
Module xyz
  Procedure test()
    Protected size
    !v_size = v_myval1;
    Debug size
  EndProcedure
EndModule
xyz::test()

[jassing]

Can you call a function defined in C directly from PB?
or
can you call a PB procedure from w/in C? (Declare with procedurec)?