Replace #include guards with #pragma once

[c4rlo]

• Make the names of #include guards consistent across the project (with a special category for src/fdosecrets/*/*.h based on prevailing usage). I have left out headers that clearly originate from other projects.
• Also make the format of the comment after the #endif consistent.
• Remove one case of #pragma once, replacing it with an #include guard.

Per discussion below, this PR now replaces #include guards with #pragma once. This was done using the following script:

#!/usr/bin/python

import pathlib
import re


def replace(match, path, is_found):
    is_found[0] = True
    begin_newline = match.group(1)
    body = match.group(2)
    print(f"{path}: fixing")
    num_end_newlines = 0
    for c in reversed(body):
        if c == "\n":
            num_end_newlines += 1
        else:
            break
    if num_end_newlines > 1:
        body = body[:(1-num_end_newlines)]
    return (f"{begin_newline}#pragma once\n{body}")


def process(path):
    content = path.read_text()
    if re.search(r"^#pragma once", content, flags=re.MULTILINE):
        print(f"{path}: ok")
        return

    is_found = [False]
    processed = re.sub(
        r"(^|\n)#ifndef .+?\n#define .+?\n(.*\n)#endif.+?\n?$",
        lambda m: replace(m, path, is_found),
        content,
        count=1,
        flags=re.DOTALL,
    )
    if not is_found[0]:
        print(f"{path}: missing")
    else:
        path.write_text(processed)


def relevant_files():
    yield from pathlib.Path("src").walk()
    yield from pathlib.Path("tests").walk()


for dirpath, dirnames, filenames in relevant_files():
    if str(dirpath) == "src":
        dirnames.remove("thirdparty")
    for name in filenames:
        path = dirpath / name
        if path.suffix in (".h", ".h.cmake") and str(path) != "src/streams/qtiocompressor.h":
            process(path)

Testing strategy

TeamCity

Type of change

• ✅ Refactor (significant modification to existing code)

[droidmonkey]

Convince me why we shouldn't just switch everything over to #pragma once. @phoerious what are your thoughts?

[c4rlo]

Yeah, that was my other thought. But it's not standardised. I haven't tried to look into which compilers do or don't support it.

[droidmonkey]

Every compiler supports it on platforms we support. The only hold out was GCC prior to version 3.4 which is ancient.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 64.83%. Comparing base (a02ddc7) to head (b8fb916).

❗ Current head b8fb916 differs from pull request most recent head 9c9726b

Please upload reports for the commit 9c9726b to get more accurate results.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #9069      +/-   ##
===========================================
+ Coverage    63.74%   64.83%   +1.08%     
===========================================
  Files          362      342      -20     
  Lines        44733    44392     -341     
===========================================
+ Hits         28515    28778     +263     
+ Misses       16218    15614     -604     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[phoerious]

I think most people would expect include guards and its what IDEs tend to auto generate. Besides that I don't really care what we use. Consistency would be nice.

[droidmonkey]

I prefer #pragma once since it is (1) one line, (2) easy to understand, (3) doesn't require unique naming, (4) modern and hip 😉

@c4rlo do you mind making that switch?

[droidmonkey]

Bumping this

[c4rlo]

I can have another look at this, yes. Happy to go with #pragma once.

[c4rlo]

Updated to #pragma once.

[c4rlo]

The diff with this file and a few others is that Windows-style line endings were converted to Unix-style line endings.

[droidmonkey]

Not surprised these aren't fully normalized

[droidmonkey]

Cool script!