Use preprocessor in header

[Bryan Parkoff]

I plan to create a library when I complete the implementation in both
header code and source code. I declare variable and function in header code
and I define variable and function in source code.
Do I truly need to use preprocessor if C Compiler does not need to
recompile unmodified header code and source code? What about pragma? I
often modify main.cpp to do more implementation while both Test.h and
Test.cpp are seldom modified.

For Example

/* Test.h */

#ifndef TEST_H
#define TEST_H

/* Declare global variable using extern or static */
/* Declare global function */

extern int a;
void do_test (void);

#endif /* TEST_H */

/* Test.cpp */
#include "Test.h"

int a = 0;

void do_test (void)
{
/* do something */
}

/* Main.cpp */
#include "Test.h"

int main (void)
{
do_test (void);

return 0;
}

--

Yours Truly,
Bryan Parkoff

[Thad Smith]

Re: Use preprocessor in header

Bryan Parkoff wrote:

I plan to create a library when I complete the implementation in both
header code and source code. I declare variable and function in header code
and I define variable and function in source code.
Do I truly need to use preprocessor if C Compiler does not need to
recompile unmodified header code and source code?

Yes, if you want the compiler to include the header files.

What about pragma?

Yes, what about pragma?


--
Thad

[santosh]

Re: Use preprocessor in header

Bryan Parkoff wrote:

I plan to create a library when I complete the implementation in
both
header code and source code. I declare variable and function in
header code and I define variable and function in source code.
Do I truly need to use preprocessor if C Compiler does not need to
recompile unmodified header code and source code?

Some compilers have options for creating and using precompiled headers.
Also you can skip the preprocessor stage in many compilers, but the
details of how to do that are compiler specific. You'll need to ask in
group for your compiler or platform.

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