unresolved external symbol

Oct 14, 2011 at 8:33am
sunaj (5)
Hardly a new error message :) I would really appreciate some help in cracking this nut thought...

I have 2 projects; the first contains a header file and a .c file. I have not written this code. The c file is +16000 lines. The header file is simple:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
 
#define ANSI_DECLARATORS

#define SINGLE

#ifdef SINGLE
#define REAL float
#else /* not SINGLE */
#define REAL double
#endif /* not SINGLE */


struct triangulateio {
  REAL *pointlist;                                               /* In / out */
  REAL *pointattributelist;                                      /* In / out */
  int *pointmarkerlist;                                          /* In / out */
  int numberofpoints;                                            /* In / out */
  int numberofpointattributes;                                   /* In / out */

  int *trianglelist;                                             /* In / out */
  REAL *triangleattributelist;                                   /* In / out */
  REAL *trianglearealist;                                         /* In only */
  int *neighborlist;                                             /* Out only */
  int numberoftriangles;                                         /* In / out */
  int numberofcorners;                                           /* In / out */
  int numberoftriangleattributes;                                /* In / out */

  int *segmentlist;                                              /* In / out */
  int *segmentmarkerlist;                                        /* In / out */
  int numberofsegments;                                          /* In / out */

  REAL *holelist;                        /* In / pointer to array copied out */
  int numberofholes;                                      /* In / copied out */

  REAL *regionlist;                      /* In / pointer to array copied out */
  int numberofregions;                                    /* In / copied out */

  int *edgelist;                                                 /* Out only */
  int *edgemarkerlist;            /* Not used with Voronoi diagram; out only */
  REAL *normlist;                /* Used only with Voronoi diagram; out only */
  int numberofedges;                                             /* Out only */
};

#ifdef ANSI_DECLARATORS
extern void triangulate(char *, struct triangulateio *, struct triangulateio *, struct triangulateio *);
extern void trifree(void *memptr);
#else /* not ANSI_DECLARATORS */
void triangulate();
void trifree();
#endif /* not ANSI_DECLARATORS */


I have compiled this as a static lib (.lib).

The second project contains a cpp class with a header file and a .cpp file. I have linked to the first project by
1) adding #include to the header file from the first project (see above)
2) linking to the .lib file

When I compile (I have tried with both Visual studio and gcc) I get 'unresolved external symbol' when using the triangulate method.

Can anybody see that the problem is?

Thx in advance
Oct 14, 2011 at 9:16am
Moschops (7244)
Where is the definition of the function void triangulate(char *, struct triangulateio *, struct triangulateio *, struct triangulateio *); ?
Oct 14, 2011 at 9:24am
sunaj (5)
It's in the +16000 lines triangle.c file.
I've just tried changing the extension of the file (triangle.c -> triangle.cpp) and now it compiles fine in both vc++ and gcc. I have no idea why, but it took me all morning to figure it out.
Thx for you interest.
Oct 14, 2011 at 11:08am
Moschops (7244)
If you don't specify the language used, the compilers will guess based on the filename extension.

C and C++ use different naming conventions for the symbols in the object files - http://en.wikipedia.org/wiki/Name_mangling

Topic archived. No new replies allowed.