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I have this C++ library that uses __LINE__ and _FILE__ preprocessor directives all over the place,
and I would like to disable it or turn it off without having to explicitly remove them myself.
They insert source code directories into my compiled files, making them much larger than they have to be.
Even in release mode, they're in there.
Are you sure that this is really a problem? /GF compiler option allows to have only one copy of every string in executable file. So, total number of strings added to executable by this library is equal to number of source files in the library.
__FILE__ and __LINE__ macros are very useful for error handling and diagnostics. It is a good idea to learn from library writers, how to use this feature, instead of removing it.
http://msdn.microsoft.com/en-us/libr...=vs.80%29.aspx
Thanks, I understand their purpose, but that doesn't diminish the fact I want them removed from my release build.Quote:
Originally Posted by Alex F
I take it from your response, there's no way to turn them off.
That's strange.
I just wrote a small test and __FILE__ resolves to a full path in debug builds but just to the filename in release builds.
Which version of VC++ are you using?
MSVC++ 2008. I can see the full filepaths in my hex editor. I'm compiling a dynamic library (.dll) if that matters.Quote:
Originally Posted by Marc G
I thought I just ask to see if there's an easy way to get rid of them, before I start digging into the source code
and remove them by hand.
Typically, I see most people use a #define switch and set them to empty values, but in some cases, I guess they're being lazy and
forget about it.
Never guess and forget before being sure.Quote:
Originally Posted by sinclaire
Be sure that "digging into the source code and remove them by hand" is "lazier" than using a #define preprocessor directive.Quote:
Originally Posted by sinclaire
That will not work on some compilers.Quote:
Originally Posted by sinclaire
For example:
or evenCode:#undef __FILE__
If you compile this with VC++2010, the compiler will issue a warning saying that __FILE__ is reserved and that it will simply ignore the #define or #undef.Code:#define __FILE__ ""
Good catch, Marc! :thumb:Quote:
Originally Posted by Marc G
Even the old VC6.0 gives a C4117 warning then ignores #define __FILE__.
The standard states:
Quote:
- The values of the predefined macros (except for_ _LINE_ _ and_ _FILE_ _) remain constant throughout the translation unit.
- If any of the predefined macro names in this subclause, or the identifier defined, is the subject of a #define or a #undef preprocessing directive, the behavior is undefined.
The easy way is to create your own define, and then do a global search and replace.Quote:
Originally Posted by sinclaire
And then replace __FILE_ with MY_FILE_MACRO, and __LINE__ with MY_LINE_MACRO.Code:#ifdef SHOW_FILE_LINE
#define MY_FILE_MACRO __FILE__
#define MY_LINE_MACRO __LINE__
#else
#define MY_FILE_MACRO
#define MY_LINE_MACRO
#endif
I have never seen this used. Who are these "most people"?Quote:
Typically, I see most people use a #define switch and set them to empty values,
You can't undefine a compiler preprocessor symbol such as __FILE__ and __LINE__ without invoking undefined behaviour. The __FILE__ and __LINE__ macros are not only compiler macros, they are mandated by the ANSI C++ rules to perform as described -- you can't change them.
Regards,
Paul McKenzie
I meant the macro or function that uses __FILE__ is set to a "do nothing" state. I didn't give an example, so you assumed wrong.
On the contrary, it's not my code. I'm not obligated to fix it. I'll hack and slash as I wish.Quote:
Be sure that "digging into the source code and remove them by hand" is "lazier" than using a #define preprocessor directive.
Thanks.
If you have a problem, it's good to provide as much as possible details.Quote:
Originally Posted by sinclaire
If you post a quiz, it's nice to specify that.
// Here is a discussion forum and not an interview.
Well then, don't do it!Quote:
Originally Posted by sinclaire
Not so fair...Quote:
Originally Posted by sinclaire
You are welcome!Quote:
Thanks.
I mentioned a "define switch". This is a define switch:
I didn't say a thing about redefining __FILE___. You guys brought that up.Code:#ifdef DEBUG
// do something
#else
// do nothing
#endif
Thanks.
Mmm, but you wrote "I have this C++ library that uses __LINE__ and _FILE__ preprocessor directives all over the place,Quote:
Originally Posted by sinclaire
and I would like to disable it or turn it off without having to explicitly remove them myself." in your first post...
Disabling or turning it off -> redefine.