Any script to strip out the compiled source in C++

In my C++ file, I have

#ifdef DEBUG 
    then blah
#else 
    blooh. 

I want to strip out all text that does not get compiled after preprocessing, so that if DEBUG is not defined, then all statement of the form:

#ifdef DBU开发者_如何学GoG 
    /* some debug code */ 
#endif

gets stripped out of the source.

EDIT: Here is an example :

#include <iostream>
//#define DEBUG
int main(){
  #ifdef DEBUG
      cout << "In debug\n";
  #endif
     cout << "hello\n";
  return 0;
 }

And after running the script , the output should be

#include <iostream>
//#define DEBUG
int main(){
  cout << "hello\n";
 return 0;
}

Is just running the preprocessor not good enough? For example g++ -E?

Just run your compiler's preprocessor with the appropriate defines. On Windows, this would be cl /EP file and on Linux gcc -E. Most likely, you'll have to pass your defines as well, using -DFoo.

I don't know the answer to your question, but Google does:

• A Partial Preprocessor for C
• cpp-partial -- preprocessor directive partial evaluator

The preprocessor does this.

You can use g++ -E somefile.cpp to see what it generates.