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<p>Hello, </p>
<p>For the senior project in my undergraduate studies, my team and I
are developing a tool that will evaluate the format and code
conventions of a c++ program, outputting a score and displaying
useful messages, very much like pylint for python. <br>
</p>
<p>The idea is kind of like clang-format except no alterations to
the code should be made. The tool would be used as a teaching aid
and automatic grader. To handle the beautiful diversity of c++, it
shouldn't constrain the author to any particular style (although
it should be able to do that too). For example: open curly braces
on same line as function declaration compared to having them on a
new line. In this case, the tool could check for consistency only.
As long as the entire file has the same format, you will get a
perfect score. If, however, there are 10 places of braces on same
line and 9 on newline, there will be a penalty to the score,
larger than if 18 on same line and 1 on newline. The idea is to
enforce consistency without getting in the way of authors
preferred style. This should give professors a robust tool to
teach c++.</p>
<p>I was hoping the clang community could help me understand the
inner workings of clang a little bit better. Right now, my hangup
is trying to get format data to work in conjunction with clangs
AST. What I'm trying to do is get back the whitespace, comment,
and bracket information that is loss during AST buildup. Suppose I
want to check that all operators have consistent spacing format,
something like "(2 * 2)" verses "(2*2)" verses "(2* 2)". The AST
will be used to get the semantics of that particular operator so
as to not get it confused with the array pointer operator, but I
need to count the operator whitespace prefix and postfix. The same
concept will be applied to statement whitespace circumfixs. If
done right, I should be able to refer to all operators the same
way no matter the complexity of the expression. Something like "(x
- 4) / 3 * (2 +1)" would show an inconsistency in the end part "(2
+1)" because of a missing space. <br>
</p>
<p>My first thought was to use the SourceManager locational
information to point back to the source code, then process and
identify the whitespace from there; However, this seems wildly
inefficient and inelegant. My second thought was to somehow get
clang to keep the whitespace information and add it to the AST,
but I believe there are inherent difficulties with that.</p>
<p>My biggest problem is lack of expertise within clangs source
code. Does anybody have any ideas on how I can get clang to give
me the information I need to support the above functionality?</p>
<p>Thanks for any interest. I hope this is an appropriate mailing
list to post my question.</p>
<p>Daniel.<br>
</p>
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