Repair header file include guards

[haukepetersen]

As we were pointed out a while ago, defines that start with underscores are not allowed by the C standard (I forgot the PR number where we discussed this -> could somebody help here?).

So the following style

#ifndef __MSG_H_
#define __MSG_H_

...

#endif /* __MSG_H_ */

would need to be changed to something like

#ifndef MSG_H
#define MSG_H
...
#endif /* MSG_H */

Git grep tells me there are a lot of files that need to be adjusted. So if anyone is taking this on, please do it in small, easily reviewable and logical grouped chunks...

[jnohlgard]

Use the following command to find the offending include guards:

git grep -E 'ifndef\s*__'

[BigDaddyD]

So writing a script for this change is out of the question?

[jnohlgard]

You may choose whatever method you like, a script is fine as long as it does the right thing. We will still need to do a manual code review for the change if/when you open a PR.

[kushalsingh007]

working on this one :)

[shrenikjain38]

Do we have to edit the defines starting with single underscores as well?
And by defines is it meant that it has to be done for #define and #ifdef as well?

[jnohlgard]

@shrenikjain38 Changing _FOO is a good idea. Identifiers beginning in single underscore followed by a upper case letter is also reserved.

btw, your scripted commit https://github.com/shrenikjain38/RIOT/commit/fd40ba441aa3ac6e1223d14ba275b5ee15d5e5eb breaks the C++ checks (don't modify #ifdef __cplusplus)

The #ifdef HEADER_FILE_NAME_H_ and #define HEADER_FILE_NAME_H_ are include guards that protect against multiple inclusion of the same file, both #define and #ifdef must be changed together.
Also, don't forget that there is usually a comment at the #endif containing the same symbol name as well which should be updated for consistency. e.g. #endif /* HEADER_FILE_NAME_H_ */

[jnohlgard]

another hint for anyone preparing pull requests for this issue: Read the description at the top, we won't be able to merge the changes if you don't split them into small logical groups, we need to be able to review the changes manually before we merge them.

So if anyone is taking this on, please to it in small, easily reviewable and logical grouped chunks...

[shrenikjain38]

Changing _FOO is a good idea. Identifiers beginning in single underscore followed by a upper case letter is also reserved.

Can you please elaborate it a bit more if the identifiers beginning with a single underscore are to be changed and if they are, whether those followed by an upper case letter after an underscore to be modified or not?

Also, don't forget that there is usually a comment at the #endif containing the same symbol name as well which should be updated for consistency. e.g. #endif /* HEADER_FILE_NAME_H_ */

This issue has already been taken into consideration.

Is it okay if the changes are made in a specific directory to divide the whole procedure in easily reviewable and logically grouped chunks?

[BigDaddyD]

I am currently working on fixing all headers under the boards directory. I managed to use git grep and sed to find and fix all ifndefs and defines. I was wondering if that can be used to fix the comments as well

[PeterKietzmann]

@BigDaddyD what's the status? Are you still working on it?

[miri64]

There are still some of these macros left. In sys in particular.

[zhuoshuguo]

@miri64 Will find time to handle.

[miri64]

Some are still left by git's non-concurrency ;-):

[mlenders@mk RIOT]<3 git grep "H_$"
boards/nucleo32-f303/include/board.h:#ifndef BOARD_H_
boards/nucleo32-f303/include/board.h:#define BOARD_H_
boards/nucleo32-f303/include/periph_conf.h:#ifndef PERIPH_CONF_H_
boards/nucleo32-f303/include/periph_conf.h:#define PERIPH_CONF_H_
cpu/k60/include/MK60D10.h:#define MK60D10_H_
cpu/k64f/include/MK64F12.h:#define MK64F12_H_
cpu/kw2x/include/MKW22D5.h:#define MK22D5_H_
cpu/native/include/netdev2_tap_params.h:#ifndef NETDEV2_TAP_PARAMS_H_
cpu/native/include/netdev2_tap_params.h:#define NETDEV2_TAP_PARAMS_H_
examples/ccn-lite-relay/Makefile:CFLAGS += -DCCNL_UAPI_H_
Binary file pkg/emb6/patches/0002-Rename-colliding-files-and-functions.patch matches
Binary file pkg/oonf_api/patches/0001-add-RIOT-support.patch matches
Binary file pkg/oonf_api/patches/0009-Add-missing-include.patch matches
sys/include/uuid.h:#ifndef UUID_H_
sys/include/uuid.h:#define UUID_H_