Attached is a new version of the patch for review.
I have removed all of the textual parsing and replaced it with code that finds 
a DeclRefExpr if it exists.
Unfortunately, this will catch a lot less cases, but at least it will catch 
some common ones and display them nicely.

-Terry

Attachment: PR9243v2.patch
Description: Binary data


Am 15.05.2012 um 18:41 schrieb Douglas Gregor:

> 
> On May 15, 2012, at 3:28 PM, Terry Long <[email protected]> wrote:
> 
>> 
>> Am 15.05.2012 um 16:09 schrieb Douglas Gregor
>>> 
>>> 
>>> I'm a bit uncomfortable with the textual approach here. Why not analyze the 
>>> expressions to check whether they are references to named declarations, and 
>>> use those names in the diagnostic? It won't catch some macro cases, but 
>>> it's far simpler.
>> 
>> I was also uncomfortable with the textual approach, and in fact I first 
>> tried seeing if the case expression was a DeclRefExpr that refers to a valid 
>> NamedDecl. The problem I found with that approach was that it was not 
>> catching very many situations. Doing it that way only works for enums as far 
>> as I can tell. Macros, const ints, case overflows, casting, and more 
>> complicated expressions (like "case 2+2") are not DeclRefExprs, and I don't 
>> see any obvious way to grab the necessary diagnostic info without using a 
>> textual approach.
> 
> 
> You can look through implicit conversions (e.g., promotions) and parentheses 
> to find the underlying expression. We'll get a DeclRefExpr for enumerators 
> and variables that are constant ("const int x = 17;"), which are presumably 
> the common cases. We won't get macros, of course, but we might not want to: 
> it's probably more useful to show the value we get when the macro is 
> expanded, and let the macro-substitution backtrace show how we got there.
> 
>       - Doug

_______________________________________________
cfe-commits mailing list
[email protected]
http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits

Reply via email to