[PATCH] [WIP] clang-format: Enforce EOL at EOF as required by C standard

[Daniel Jasper]

On Sun, Oct 6, 2013 at 3:23 PM, Manuel Klimek <klimek at google.com> wrote:

> On Sun, Oct 6, 2013 at 3:13 PM, Daniel Jasper <djasper at google.com> wrote:
>
>> Actually, the C++11 standard says:
>> "A source file that is not empty and that does not end in a new-line
>> character, or that ends in a new-line character immediately preceded by a
>> backslash character before any such splicing takes place, shall be
>> processed as if an additional new-line character were appended to the file."
>>
>> I think this pretty much implies that source files are allowed to not end
>> in a newline. Also, I think it is fine for clang-format to not alter its
>> input file in this regard. If your VCS requires this, configure your editor
>> appropriately ..
>>
>
> One could argue that clang-format is supposed to be the editor
> configuration for how to handle whitespace for C++ files.
>

Yes, although to me this is on the border of whitespace handling and file
encoding.

It might make sense to have this as an option?
>

Sure.. At least I don't think it would hurt. I am just having trouble with
"forcing" it, as I can imagine that there is someone somewhere that likes
files without a newline at the end and thus would see this as a negative
change.

On Sun, Oct 6, 2013 at 2:10 PM, Alp Toker <alp at nuanti.com> wrote:
>>
>>> Hi,
>>>
>>> I'm just putting this patch out there for now as it's been useful to us
>>> in its current state. Some tweaks are needed before this can land:
>>>
>>> 1) It needs a lot of existing unit tests to be fixed. The tests could be
>>> fixed before this patch goes in if anyone has the time to volunteer(!)
>>>
>>> 2) I'm not convinced it's worth even having a 'AllowNoEOL' format flag
>>> for this. The spec is clear that it's mandatory and many VCS also expect
>>> EOL at EOF to work properly.
>>>
>>> 3) That means we might do better to add a command line flag to identify
>>> that the code is being formatted for snippets, which uses the
>>> forSnippets() internally, in which case AllowNoEOL would be made true.
>>>
>>> 4) There are other rules such as trailing slash in 5.5.1.2 that I'm not
>>> sure are handled yet, though these could be worked on subequent to this
>>> patch landing.
>>>
>>> Note also that this fixes a bug in clang-format where it was reporting
>>> an error code for an empty (zero-sized) file. There's no benefit to the
>>> special case so we can just remove that check now.
>>>
>>> Here's the change:
>>>
>>>     clang-format: Enforce EOL at EOF as required by C standard
>>>
>>>     This enables end-of-line correction as specified for C-family
>>> languages.
>>>
>>>     C11 5.5.1.2p2 "A source file that is not empty shall end in a
>>> new-line
>>>     character"
>>>
>>>     The new setting 'AllowNoEOL' and the fluent
>>> FormatStyle::forSnippets() helper
>>>     are provided for consumers that prefer the old behaviour, which is
>>> preferable
>>>     for inline code snippets in documentation.
>>>
>>> Alp.
>>>
>>> --
>>> http://www.nuanti.com
>>> the browser experts
>>>
>>>
>>
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>>
>
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