[fpc-devel] Staticaly link C/C++ library (.lib) into FreePascal on Windows

[silvioprog]

On Tue, Mar 14, 2017 at 9:30 AM, LacaK <lacak at zoznam.sk> wrote:

> Hi,
>
> I have C/C++ librarby (".lib" for Windows and ".a" for Linux) from Intel
> IPP package (they distribute ".lib" and also ".dll" for Windows and ".a"
> for Linux)
>
> Can I link in FPC (on Windows) at compile time to this ".lib" versions ?
> Or only possible way is link at runtime using ".dll" (and distribute DLLs
> with my EXE)?
> (I guess, that FPC can not link to libraries not created in FPC itself. So
> format of supplied ".lib" is not compatible with what FPC expects)
>
> I am trying do something like:
> {$linklib libippi}
> function ippiThreshold_LTValGTVal_8u_C1IR(pSrcDst: PIpp8u; srcDstStep:
> int;
>        roiSize: IppiSize; thresholdLT: Ipp8u; valueLT: Ipp8u; thresholdGT:
> Ipp8u;
>        valueGT: Ipp8u): IppStatus; external; // 'ippi.dll';
>
> (In Project Options I have path to libippi.a in -Fl)
>
> But I get error: test_IPP.lpr(24,1) Error: Undefined symbol:
> IPP_IPPITHRESHOLD_LTVALGTVAL_8U_C1IR$PIPP8U$LONGINT$IPPISIZE
> $BYTE$BYTE$BYTE$BYTE$$IPPSTATUS
>

test 1: are you on win32? If so, did you try using prefix "_"? eg:

function _ippiThreshold_LTValGTVal_8u_C1IR(pSrcDst: PIpp8u; srcDstStep: int;
       roiSize: IppiSize; thresholdLT: Ipp8u; valueLT: Ipp8u; thresholdGT:
Ipp8u;
       valueGT: Ipp8u): IppStatus; external;

test 2: put the library implementation below function declaration, eg:

function _ippiThreshold_LTValGTVal_8u_C1IR(pSrcDst: PIpp8u; srcDstStep: int;
       roiSize: IppiSize; thresholdLT: Ipp8u; valueLT: Ipp8u; thresholdGT:
Ipp8u;
       valueGT: Ipp8u): IppStatus; external;
{$linklib libippi}

fix 1: check which convention your library was compiled, supposing it was
compiled supporting CDECL, you need to specify it on your Pascal binding,
avoiding low-level errors at runtime:

function _ippiThreshold_LTValGTVal_8u_C1IR(pSrcDst: PIpp8u; srcDstStep: int;
       roiSize: IppiSize; thresholdLT: Ipp8u; valueLT: Ipp8u; thresholdGT:
Ipp8u;
       valueGT: Ipp8u): IppStatus; cdecl; external;

Anyway I've tried to use COFF objects on Windows, but I'm not sure if FPC
supports that because it returns a "illegal COFF magic while reading some
lib". :-/ (on Linux it works like a charm)


> I am doing something wrong or just this is not possible ?
>
> Thank you
> -Laco.


-- 
Silvio Clécio
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