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Converting C header file statements to Delphi

I need help converting two statements from a C header file to their Delphi equivalents. The first one is the extern const statement below. I'm not sure if this should be defined as a pointer or what.

The second statement is the typedef that I've attempted to convert...I just wanted someone to check it and let me know if it is correct.

Thanks

1.
/* Memory function tables */
extern const BioAPI_MEMORY_FUNCS BioAPIMemoryFuncs;

2. Original C statement...

typedef void * (BioAPI *BioAPI_MALLOC) ( uint32 Size,
void * Allocref,
const char * File,
uint32 Line);

My converted Delphi equivalent.....

type
BioApi_Malloc = procedure( Size: Cardinal;
Allocref: Pointer;
Const _File: Char;
Line: Cardinal);

ASKER CERTIFIED SOLUTION

Russell Libby

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Russell Libby

This also returns a void (generic) pointer, so it is not a procedure

type
BioApi_Malloc = function(Size: Cardinal;
Allocref: Pointer;
Const _File: PChar;
Line: Cardinal): Pointer;

Russell

robert_marquardt

type
BioApi_Malloc = function(Size: Cardinal;
Allocref: Pointer;
Const _File: PChar;
Line: Cardinal): Pointer; stdcall;

To guess at the calling convention.

The other declaration is a global variable which is not easily accessible in Delphi.

rwcochran

ASKER

Thanks for the help guys. I found the BioAPIMemoryFuncs definition in another source file (see below)...how would this be converted to Delphi?

Thanks again....

/* Memory function tables */
const BioAPI_MEMORY_FUNCS BioAPIMemoryFuncs =
{
      _BioAPI_malloc,
      _BioAPI_free,
      _BioAPI_realloc,
      _BioAPI_calloc,
      NULL
};

Russell Libby

Here is the delphi translation based on C source I found on the Net. Appears uou might have a newer definition, as the malloc function takes more parameters than the version I looked at. Also, are YOU are supposed to implement the memory functions on your side of this?? Hard to tell without seeing the full source, so I declared _BioPAPI_XXXX calls as variable types.

type
TBioAPI_MALLOC = function(Size: Cardinal; Allocref: Pointer): Pointer; stdcall;
TBioAPI_FREE = procedure(MemBlock: Pointer; Allocref: Pointer); stdcall;
TBioAPI_REALLOC = function(Memblock: Pointer; Size: Cardinal; Allocref: Pointer): Pointer; stdcall;
TBioAPI_CALLOC = function(Num: Cardinal; Size: Cardinal; AllocRef: Pointer): Pointer; stdcall;

type
TBioAPI_MEMORY_FUNCS = packed record
Malloc_func: TBioAPI_MALLOC;
Free_func: TBioAPI_FREE;
Realloc_func: TBioAPI_REALLOC;
Calloc_func: TBioAPI_CALLOC;
AllocRef: Pointer;
end;

var
_BioAPI_malloc: TBioAPI_MALLOC; // These obviously need to be set
_BioAPI_free: TBioAPI_FREE;
_BioAPI_realloc: TBioAPI_REALLOC;
_BioAPI_calloc: TBioAPI_CALLOC;

BioAPI_MEMORY_FUNCS: TBioAPI_MEMORY_FUNCS;

initialization

BioAPI_MEMORY_FUNCS.Malloc_func:=@_BioAPI_malloc;
BioAPI_MEMORY_FUNCS.Free_func:=@_BioAPI_free;
BioAPI_MEMORY_FUNCS.Realloc_func:=@_BioAPI_realloc;
BioAPI_MEMORY_FUNCS.Calloc_func:=@_BioAPI_calloc;
BioAPI_MEMORY_FUNCS.Allocref:=nil;

end.

rwcochran

ASKER

Very helpful....thanks. As far as whether I have to implement the memory functions on my side or not, at this point I'm not sure.

I'm just slowing working through the basic BioApi functions.... I'm trying to get to the point where I can talk to the fingerprint reader. I ran into the BioAPIMemoryFuncs reference when working on the following function:

bioReturn := BioAPI_ModuleAttach(uuid, bioVersion, BioAPIMemoryFuncs, 0,
0, 0, 0, NULL, 0, NULL, &hModule);

I've already implemented the following BioApi functions and they seem to work fine.
bioReturn := BioAPI_Init( bioVersion, 0, nil, 0, nil );
bioReturn := BioAPI_ModuleLoad( uuid, 0, nil, nil);

The next BioApi function I'll be woking on is:
bioReturn = BioAPI_SetGUICallbacks(hModule,
NULL, NULL,
state_callback, &callbac_ctx);

I really appreciate all the help.

asiasker

hi rllibby,
"Here is the delphi translation based on C source I found on the Net"
i need translations of other files.. if you see them i wil be Thankfull.

asiasker

hi rllibby and rwcochran ,

rllibby :"Here is the delphi translation based on C source I found on the Net"
i need translations of other files.. if you see them i wil be Thankfull.

rwcochran , can you help to me same problem as you already solved?