parse error before "extern"

[Sonya Blade]

Dear All,

I've the working C code just before 1 day back, but when I try to compile the project 
as of now I receive the following error. What could be the possible reason of that ?

C:\Users\......\Downloads\petsc-3.3-p6\include\mpiuni\mpi.h|119|error: parse error before "extern"|
D:\TEST_FOLDER_dell\PROJECTS\CBFortran\Slepc_C\main.c||In function `main':|
||=== Build finished: 1 errors, 6 warnings (0 minutes, 2 seconds) ===|



The code snippet that corresponds to possible are is follow, 

// CODE SNIPPET 
#if defined(__cplusplus)
extern "C" {
#endif

/* require an int variable large enough to hold a pointer */
#if !defined(MPIUNI_INTPTR)
#define MPIUNI_INTPTR long
#endif

/* MPIUNI_TMP is used in the macros below only to stop various C/C++ compilers
from generating warning messages about unused variables while compiling PETSc.
*/

 extern void *MPIUNI_TMP;     // CARET POSITION OF COMPILER POINTS HERE 

#define MPI_COMM_WORLD       1
....
.....
....
// CODE SNIPPET END