[llvm-dev] changing variable naming rules in LLVM codebase

[David Greene via llvm-dev]

It very much depends on what is following the code snippit.  If the
second "if" is guarding a substantial block of code, "constantExpr"
might very well be a good name.  Otherwise something like "cExpr" or
"constExpr" might be fine.

In the past when I have seen things like "CE" in the code, it's not
always immediately clear to me what it is.  I have to go find the
declaration.

                             -David


Krzysztof Parzyszek via llvm-dev <llvm-dev at lists.llvm.org> writes:

> The reason is clear: the variable name in such a context doesn't add
> anything, since it's obvious what it is. Long names should be used
> where meaning needs to be conveyed, otherwise they just obfuscate the
> code needlessly.
>
> -Krzysztof
>
> On 2/12/2019 3:17 PM, Alex Denisov via llvm-dev wrote:
>> I would assume that the proper name in this case is constantExpr, and not CE.
>> This is not really an acronym, but rather a shortcut taken for some unclear reason.
>>
>>> On 12. Feb 2019, at 13:02, Björn Pettersson A via llvm-dev <llvm-dev at lists.llvm.org> wrote:
>>>
>>> (Sorry if this subject already has been discussed, but I could not find any clear rules/recommendations.)
>>>   What would the recommendation be for acronyms (I’ve seen the rule
>>> about avoiding them unless they are “well known”,
>>> but sometimes an acronym is useful, and we at least need to have some recommendation for the “well known” ones).
>>>   Example:
>>>        if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V))
>>>        if (CE->getOpcode() == Instruction::GetElementPtr &&
>>>            CE->getOperand(0)->isNullValue()) {
>>>   In the above example, is the recommendation to use “ce” instead
>>> of “CE” now? Or should it be “cE”?
>>> With lowerCamelCase one might think that “cE” is the correct one (although I personally think that one looks quite ugly).
>>>   Maybe there should be an exception that variable names that start
>>> with an acronym still should start with an upper case letter?
>>>   /Björn
>>>     From: llvm-dev <llvm-dev-bounces at lists.llvm.org> On Behalf Of
>>> Michael Platings via llvm-dev
>>> Sent: den 7 februari 2019 23:11
>>> To: llvm-dev at lists.llvm.org
>>> Cc: nd <nd at arm.com>
>>> Subject: [llvm-dev] RFC: changing variable naming rules in LLVM codebase
>>>   TL;DR: change the rule for variable names from UpperCamelCase to
>>> lowerCamelCase.
>>>
>>>   
>>>
>>> Just to get wider visibility on this, I'm raising this again as an RFC, as suggested by Roman Lebedev.
>>>
>>>   
>>>
>>> My original post from last week is here and gives a rationale: http://lists.llvm.org/pipermail/llvm-dev/2019-February/129854.html. There seemed to be general agreement that the status quo is not ideal.
>>>
>>>   
>>>
>>> Chris Lattner pointed out that this came up in 2014 as well: http://lists.llvm.org/pipermail/llvm-dev/2014-October/077685.html>>
>>>   
>>>
>>> I've created a patch to implement the change. Review and comments welcome: https://reviews.llvm.org/D57896>>
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