C code compiles in Windows, gives compilation error on Linux

Question

Contents of somefile.h:

#ifndef __SOMEFILE_H
#define __SOMEFILE_H

#ifdef __cplusplus
extern "C" {
#endif

typedef struct _table_t
{
     void (*somefunction1)();
     void (*somefunction2)(int a);
     void (*somefunction3)(int a, int *b);
}table_t;

void doSomething1();
void doSomething2();

#ifdef __cplusplus
} // error at this line: expected constructor, destructor, or type conversion before '(' token
#endif
#endif

Shown above is the code snippet and the error I get when I compile my code on Linux. The same code compiles fine on Windows with no complaints.

About the source file:

all.h is a header file which includes:
#include "header1.h"
#include "header2.h"
#include "header3.h"
#include "somefile.h"

Here is the content of somefile.c

#include "all.h" 
#include "header4.h"
jumptable_t jumptable_a = 
{
       a_function1();
       a_function2(int a);
       a_function3(int a, int *b);
}

//more code
void function1()
{
     a_function1();
}

void function2(int a)
{
    a_function2(a);
}

void function3(int a, int *b)
{
    a_function3(a, b);
}


void doSomething1()
{

}
void doSomething2()
{

}

Answer 1

Macro with leading double underscores is illegal. You need to change your include guard.

Answer 2

You need a ; after the } of jumptable_a . And use commas instead of semicolons in the initializer of jumptable_a .

The braces make it look like a somethink function-like, but it's not.

Also, in somefile.h the struct is called table_t , but in somefile.c you are using jumptable_t , which I assume is an error introduced when writing the post here.