Question

I declare macros which would make it easy to replicate the logic of writing to a file Log
I end up getting the error C2065: ‘flog’ : undeclared identifier.
But I don’t get this error for log_buffer.

I am using Visual Studios 2008 IDE.

What am i doing wrong?

#ifndef ERROR_LOG_MACRO

#define ERROR_LOG_MACRO 1

#define SETERRORPARAMS  char log_buffer[MAX_PATH]; \
                        char flog[MAX_PATH]; \
                        FILE *err_log_fp; 

/*
    Arguments: x (Name of the File) 
               y (File Path without the Filename)
               z (Mode) 
*/                  
#define OPENFILE(x,y,z) strcpy(flog,y); \
                        strcat(flog,"\\"); \
                        strcat(flog,x); \ 
                        err_log_fp = fopen(flog, z); 

#define WRITELOG(x)     if(err_log_fp) \
                            fwrite(log_buffer, sizeof(char), strlen(log_buffer), err_log_fp);

#define CLOSEFILE       if(err_log_fp) \
                            fclose(err_log_fp);

#endif

I even tried to do

#define OPENFILE(x,y,z)   SETERRORPARAMS \ 
                          ... \

But even this did not work.

Answer 1

You probably have trailing whitespaces after the first line of your macro:

#define SETERRORPARAMS  char log_buffer[MAX_PATH]; \______ <-- make sure you have no whitespaces
                    char flog[MAX_PATH]; \
                    FILE *err_log_fp; 

Either that, or you’re not using the macro and log_buffer is declared elsewhere.