include-guard-convert 1.0.1

Converts C/C++ preprocessor include guards from the `#ifndef XY_H`, `#define XY_H` to the `#pragma once` paradigm.

include-guard-convert

Converts C/C++ preprocessor include guards from the #ifndef XY_H, #define XY_H to the #pragma once paradigm.

Header files have the problem that they should be included once per compile unit; thus, they usually deploy a scheme that looks like this

/*
 * some funky comment, doxygen, copyright info
 */
#ifndef MY_HEADERFILE_H
#define MY_HEADERFILE_H

class declare_and_define_whatever_you_want
{
...
};
#endif /* maybe a comment that this belongs to MY_HEADERFILE_H */

Since this lead to a few bugs (namely, sometimes there are #define naming conflicts, or copy&paste errors), I've wrote a script to make the same file look like this:

/*
 * some funky comment, doxygen, copyright info
 */
#pragma once

class declare_and_define_whatever_you_want
{
...
};

Dependencies

• C preprocessor (only tested with the GCC cpp; clang's clang-cpp should work as well)
• Python 3 >= 3.10

Installation

pip install include-guard-convert

or run directly using uvx or pipx (replace as wanted)

uvx include-guard-convert FILE1.H FILE2.HPP FILE3.HH

Caveats

• The include guards should be the surround the whole semantic content of the file. That means that #ifndef must be on the first non-comment, non-whitespace, non-empty line of your source code and that it must end with the matching #ifndef line, which may only be followed by empty or whitespace-only lines.
• The #define constants must be UPPERCASE_UNDERSCORE_0_TO_9_ONLY style.