dllexport.h File Reference

(37a72b0150ec36b4ea27175039afc28c62207b0c)

Tweaking visibility of C variables/functions. More...

#include "ruby/internal/config.h"
#include "ruby/internal/compiler_is.h"

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Macros
#define	RUBY_EXTERN   extern
	Declaration of externally visible global variables. More...
#define	RBIMPL_SYMBOL_EXPORT_BEGIN()   /* void */
	Shortcut macro equivalent to RUBY_SYMBOL_EXPORT_BEGIN extern "C" {. More...
#define	RBIMPL_SYMBOL_EXPORT_END()   /* void */
	Counterpart of RBIMPL_SYMBOL_EXPORT_BEGIN. More...

Detailed Description

Tweaking visibility of C variables/functions.

Author

Ruby developers ruby-.nosp@m.core.nosp@m.@ruby.nosp@m.-lan.nosp@m.g.org

Copyright

This file is a part of the programming language Ruby. Permission is hereby granted, to either redistribute and/or modify this file, provided that the conditions mentioned in the file COPYING are met. Consult the file for details.

Warning

Symbols prefixed with either RBIMPL or rbimpl are implementation details. Don't take them as canon. They could rapidly appear then vanish. The name (path) of this header file is also an implementation detail. Do not expect it to persist at the place it is now. Developers are free to move it anywhere anytime at will.

Note

To ruby-core: remember that this header can be possibly recursively included from extension libraries written in C++. Do not expect for instance __VA_ARGS__ is always available. We assume C99 for ruby itself but we don't assume languages of extension libraries. They could be written in C++98.

Definition in file dllexport.h.

Macro Definition Documentation

RBIMPL_SYMBOL_EXPORT_BEGIN

#define RBIMPL_SYMBOL_EXPORT_BEGIN

(

)

/* void */

Shortcut macro equivalent to RUBY_SYMBOL_EXPORT_BEGIN extern "C" {.

@shyouhei finds it handy.

Definition at line 65 of file dllexport.h.

RBIMPL_SYMBOL_EXPORT_END

#define RBIMPL_SYMBOL_EXPORT_END

(

)

/* void */

Counterpart of RBIMPL_SYMBOL_EXPORT_BEGIN.

Definition at line 74 of file dllexport.h.

RUBY_EXTERN

#define RUBY_EXTERN   extern

Declaration of externally visible global variables.

Here "externally" means they should be visible from extension libraries. Depending on operating systems (dynamic linkers, to be precise), global variables inside of a DLL may or may not be visible form outside of that DLL by default. This declaration manually tweaks that default and ensures the declared variable be truly globally visible.

extern VALUE foo;      // hidden on some OS
RUBY_EXTERN VALUE foo; // ensure visible

Definition at line 45 of file dllexport.h.