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digitalmars.D.learn - Creating a .di file for a custom C library

reply Brad <bjazmoore outlook.com> writes:
I would like to use an updated version of the Termbox library 
(written in C) with D.  I have the .h file.  This is new 
territory for me (why try something easy - right?).  I think I 
need to create a .di file that corresponds to the .h file.  I 
also suspect that I need to put the library file (C code) into 
the project as a file somehow.  I am probably just not looking in 
the right place for the documentation, but I cannot seem to find 
a lot of guidance in this area.

Thanks in advance.
Mar 29 2021
next sibling parent evilrat <evilrat666 gmail.com> writes:
On Tuesday, 30 March 2021 at 04:01:12 UTC, Brad wrote:

 I would like to use an updated version of the Termbox library 
 (written in C) with D.  I have the .h file.  This is new 
 territory for me (why try something easy - right?).  I think I 
 need to create a .di file that corresponds to the .h file.  I 
 also suspect that I need to put the library file (C code) into 
 the project as a file somehow.  I am probably just not looking 
 in the right place for the documentation, but I cannot seem to 
 find a lot of guidance in this area.

 Thanks in advance.


No just convert C signatures to corresponding D signatures in 
regular .d file.
Then you need to build original C library, and then when building 
D program you link(pass produced .lib/.a files to 
compiler/linker) this stuff with C library.

After all your binaries is just language agnostic bytes, however 
there is calling conventions that exist for interop, your .h 
contains definitions (aka contract) of what it does, and produced 
binaries (.exe, .a, .lib, .dll, .so) contains actual machine 
code, so on D side you must match that contract and then tell the 
linker to embed the machine code from .a/.lib in your final 
executable/DLL.
Mar 30 2021
prev sibling next sibling parent Chris Piker <chris hoopjump.com> writes:
On Tuesday, 30 March 2021 at 04:01:12 UTC, Brad wrote:

 I would like to use an updated version of the Termbox library 
 (written in C) with D.  I have the .h file.  This is new 
 territory for me (why try something easy - right?).  I think I 
 need to create a .di file that corresponds to the .h file.  I 
 also suspect that I need to put the library file (C code) into 
 the project as a file somehow.  I am probably just not looking 
 in the right place for the documentation, but I cannot seem to 
 find a lot of guidance in this area.

 Thanks in advance.


Hi Brad

I used dstep https://code.dlang.org/packages/dstep to help me 
with this process.  Though I ended up checking the output and 
fixing a couple oddities in the "extern (C):" line, it was *huge* 
time saver.

The result was a D module file (i.e. thing.d, not thing.di) that 
I could include like any other, so long as the C library was 
specified on the compiler command line.

In addition, you might want to check out 
https://wiki.dlang.org/Deimos where standard patterns are 
discussed for D prototypes of C libraries.  I ended up using the 
command line:

   dub init --format=deimos

to start off the wrapper lib package, then copied in the C 
header, and then ran dstep.

Cheers,
Mar 30 2021
prev sibling parent Ferhat =?UTF-8?B?S3VydHVsbXXFnw==?= <aferust gmail.com> writes:
On Tuesday, 30 March 2021 at 04:01:12 UTC, Brad wrote:

 I would like to use an updated version of the Termbox library 
 (written in C) with D.  I have the .h file.  This is new 
 territory for me (why try something easy - right?).  I think I 
 need to create a .di file that corresponds to the .h file.  I 
 also suspect that I need to put the library file (C code) into 
 the project as a file somehow.  I am probably just not looking 
 in the right place for the documentation, but I cannot seem to 
 find a lot of guidance in this area.

 Thanks in advance.


I never needed or used .di files. Dstep[1] can create d modules 
containing c header definitions. Recently, I used to create a d 
binding [2] for shapelib[3]. I just added "module shapelib;" at 
the beginning of the file, nothing else. Some c headers may 
require extra steps IMO.


1: https://github.com/jacob-carlborg/dstep
2: https://github.com/aferust/shapelib-d/blob/main/shapelib.d
3: https://github.com/OSGeo/shapelib
Mar 30 2021