C预处理器中的双氧，如果

Question

I document my C-Code with Doxygen and got a problem. Consider following example:

in defines.h:

#ifndef DEFINES_H_
#define DEFINES_H_

#define ENABLED 1

#endif

in test.c

#include <defines.h>

/**
 *  @brief  This is the first testfunction
 *  @return   void
 */
void testFunc1(void)
{
    //...do stuff
}

#if ENABLED
/**
 *  @brief  This is the second testfunction
 *  @return   void
 */
void testFunc2(void)
{
    //...do stuff
}
#endif

Doxygen finds testFunc1 and documents it well, but it cannot find testFunc2. To define ENABLED in the .doxyfile wont fix my problem.

Is there a way to get this running? (Note, I need to define ENABLED inside my c-Project!)

Answer 1

[misread the source snippet]

You probably want #ifdef instead of #if .

From the docs for #if :

The '#if' directive allows you to test the value of an arithmetic expression, rather than the mere existence of one macro. Its syntax is

 
  
  
   
   #if expression controlled text #endif /* expression */
  
   

expression is a C expression of integer type, subject to stringent restrictions.

and for #ifdef :

The simplest sort of conditional is

 #ifdef MACRO controlled text #endif /* MACRO */ 

This block is called a conditional group . controlled text will be included in the output of the preprocessor if and only if MACRO is defined. We say that the conditional succeeds if MACRO is defined, fails if it is not.