Calling C function in .o file from lazarus.

[BSaidus]

Hello, I have written a little C program composed in 2 c files
One containe

Code: [Select]

main function and the second one containe my function called "CopyFile".
I compiled a project and it work fine.
Then I decided to include the object file in my lazarus project using this code

Code: Pascal  [Select][+][-]

1. {$L copyfuncs.o}
2. function fBinFileCopyC(const infile: PChar;
3.   const outfile: PChar; fp: TfCopyCallback ): Integer; cdecl; external;    
4.  

.

After compiling I have these error in compile time :

Code: Pascal  [Select][+][-]

1. Compile Project, Target: testcopc.exe: Exit code 1, Errors: 8
2. testcopc.lpr(21,1) Error: Undefined symbol: _fopen
3. testcopc.lpr(21,1) Error: Undefined symbol: _fseek
4. testcopc.lpr(21,1) Error: Undefined symbol: _fread
5. testcopc.lpr(21,1) Error: Undefined symbol: _fwrite
6. testcopc.lpr(21,1) Error: Undefined symbol: _fclose
7. testcopc.lpr(21,1) Error: Undefined symbol: _ftell
8. testcopc.lpr(21,1) Error: Undefined symbol: _malloc
9. testcopc.lpr(21,1) Error: Undefined symbol: _free
10.  

C function code is

Code: C  [Select][+][-]

1. int fBinFileCopyC(const char *infile, const char *outfile, fCopyCallback fp ) {
2.   char *aBuff;
3.   int iRead,
4.     bSize,
5.     ifsize = 0, /* size of the file */
6.     iftotread = 0;
7.   FILE *fin  = NULL,
8.        *fout = NULL;
9.   /* */
10.   bSize = 64*1024*1024;
11.   aBuff = NULL;
12.   aBuff = (char*)malloc( bSize*sizeof(char) );
13.   if ( aBuff == NULL) { return -10; }
14.   if ( (fin  = fopen(infile,  "rb")) == NULL ) {  return -11; }
15.   if ( (fout = fopen(outfile, "wb")) == NULL ) {  return -12; }
16.   /* get size of file */
17.   /*fsetpos(fin, )*/
18.   if ( fseek(fin, 0, SEEK_END) == 0 ) {
19.     ifsize = ftell(fin);
20.   }
21.   fseek(fin, 0, SEEK_SET);
22.   /*--------------------------------*/
23.   while (1) {
24.     iRead = fread( aBuff, sizeof(char), bSize*sizeof(char), fin );
25.     if (iRead != 0) {
26.       fwrite( aBuff, sizeof(char), iRead, fout);
27.       iftotread += iRead;
28.       /* put backup fonction here */
29.       if (fp) { fp( infile, outfile, ifsize, iftotread, iRead ); }
30.     } else {  break;  }
31.   }
32.   free(aBuff);
33.   fclose(fin);
34.   fclose(fout);
35.   return 0;
36. }
37.  

So any one have experimented this issue,
Thanks for help.

[Peter H]

I think these undefined symbols are from C runtime library, so the C runtime library must be linked.
Not that I have any experience doing this with pascal, I am unsure if the program will work.

[BSaidus]

@Piter H
The C program work fine and yes the symbols are from msvcrt C library .
Bjr how to compile a C file into object one without need to external libs

[BlueIcaro]

Hi, I don't have any experince, but I found this document, that may can help you.

https://github.com/williamhunter/pascal-bindings-for-c/blob/master/docs/Creating%20Pascal%20bindings%20for%20C%20(v1.0).pdf

/BlueIcaro

[PascalDragon]

@Piter H
The C program work fine and yes the symbols are from msvcrt C library .
Bjr how to compile a C file into object one without need to external libs

You either need to provide those functions yourself or you need to link against the C library. That are the only two choices you have in this case.

Or implement your code in Pascal.

[Peter H]

I think the C RTL will use its own memory allocator, so there are two heaps and this could give problems.

[BSaidus]

Hi, I don't have any experince, but I found this document, that may can help you.

https://github.com/williamhunter/pascal-bindings-for-c/blob/master/docs/Creating%20Pascal%20bindings%20for%20C%20(v1.0).pdf

/BlueIcaro

Thank you for infos, it help me a lot.
Just do link with libmsvcrt from mingw distro.

Code: [Select]

{$link copy.o}
{$linklib libmsvcrt.a}

It do the work