Add ClangFormat to pre-commit

[hugovk]

Follow on from #4493 / #4770.

As reminded by #8011 (comment) we didn't add this to pre-commit/CI at the time. Let's add it now.

Update the others at the same time.

[Yay295]

This change looks technically correct, but also I'm pretty sure the previous indentation was intentional for readability.

[radarhere]

There is a clang setting to change this, https://stackoverflow.com/a/66004745, but I don't think the effect of the alternative settings on other files looks good.

[Yay295]

Here we lose the indentation with the other variable comments.

[radarhere]

See https://github.com/python-pillow/Pillow/pull/8015/files#r1582006590 for a possible solution.

[Yay295]

A lot of these changes don't really improve readability, imo.

[radarhere]

Suggested change

	int load_flags; /* FreeType load_flags parameter */
	int error;
	int error;
	int load_flags; /* FreeType load_flags parameter */

If the indentation is a concern, then this could be a solution - by grouping load_flags with the other commented lines, the indentation is kept.

[hugovk]

Or can we now declare on first use, a few lines below?

-    load_flags = FT_LOAD_DEFAULT;
+    /* FreeType load_flags parameter */
+    int load_flags = FT_LOAD_DEFAULT;

[radarhere]

Hmm, every variable in this function is declared at the top at the moment, and I think the consistency of that is good.

I'm happy just leaving it as it currently is in this PR.

[Yay295]

Currently in Python when a function declaration is split across multiple lines, the closing parenthesis is on the same level as the def.

Pillow/src/PIL/Image.py

Lines 3484 to 3488 in c250a44

	def register_open(
	id,
	factory: Callable[[IO[bytes], str | bytes], ImageFile.ImageFile],
	accept: Callable[[bytes], bool | str] | None = None,
	) -> None:

However with this change in C the closing parenthesis is on the same line as the last argument.

https://github.com/hugovk/Pillow/blob/5597f618a3b5cf8e208dded44a2107313c47122d/src/libImaging/BcnDecode.c#L825-L833

static int
decode_bcn(
    Imaging im,
    ImagingCodecState state,
    const UINT8 *src,
    int bytes,
    int N,
    int C,
    char *pixel_format) {

It's the same with function calls as well. It looks like this is changed with AlignAfterOpenBracket: BlockIndent.

[radarhere]

However with this change in C the closing parenthesis is on the same line as the last argument.

From what I can see, this is the style of C that is already in place. For the example you've cited, here how it is in main.

Pillow/src/libImaging/BcnDecode.c

Lines 827 to 829 in 58a4797

	static int
	decode_bcn(
	Imaging im, ImagingCodecState state, const UINT8 *src, int bytes, int N, int C, char *pixel_format) {

Here are some other examples.

Pillow/src/_imagingft.c

Lines 250 to 257 in 58a4797

	static size_t
	text_layout_raqm(
	PyObject *string,
	FontObject *self,
	const char *dir,
	PyObject *features,
	const char *lang,
	GlyphInfo **glyph_info) {

Pillow/src/_imagingcms.c

Lines 404 to 412 in 58a4797

	_buildProofTransform(
	cmsHPROFILE hInputProfile,
	cmsHPROFILE hOutputProfile,
	cmsHPROFILE hProofProfile,
	char *sInMode,
	char *sOutMode,
	int iRenderingIntent,
	int iProofIntent,
	cmsUInt32Number cmsFLAGS) {

Unless I've missed something in looking at the changes here, this PR isn't even moving any closing brackets from a newline onto the same line as the last argument - it's just making the existing style slightly more apparent because it's splitting up some long lines.

I'm not opposed to changing the style for its own sake, I just don't think the current state of this PR affects what you're describing.

[Yay295]

Ah, yeah that does seem to be the case. I didn't find any instances of ) { at the start of a line, other than three if blocks.

Pillow/src/_imagingcms.c

Line 220 in 58a4797

) {

Pillow/src/_imagingcms.c

Line 238 in 58a4797

) {

Pillow/src/libImaging/TiffDecode.c

Line 713 in 58a4797

) {

I would prefer the other format, but that could be a separate change.