[cfe-commits] [PATCH] CallExprs returning references can be lvalues

[Zhongxing Xu]

On Thu, Jun 3, 2010 at 1:14 PM, Ted Kremenek <kremenek at apple.com> wrote:

>
> On Jun 2, 2010, at 10:11 PM, Zhongxing Xu wrote:
>
>
>
> On Thu, Jun 3, 2010 at 1:08 PM, Ted Kremenek <kremenek at apple.com> wrote:
>
>>
>> On Jun 2, 2010, at 10:04 PM, Zhongxing Xu wrote:
>>
>>
>>
>> On Thu, Jun 3, 2010 at 1:02 PM, Ted Kremenek <kremenek at apple.com> wrote:
>>
>>>
>>> On Jun 2, 2010, at 9:48 PM, Zhongxing Xu wrote:
>>>
>>> Is it necessary to add all RHS of assignment expr as block-level expr?
>>>>
>>>> +    return addStmt(B->getLHS(), AddStmtChoice::AsLValueNotAlwaysAdd);
>>>> +  }
>>>>
>>>
>>> Here better to use visitStmt, because addStmt() means we want to 'add'
>>> the statement. Maybe we should modify some of the existing code to emphasize
>>> this.
>>>
>>>
>>>>
>>>
>>>
>>> That's right.  The rest of the cases in that method use addStmt() because
>>> they introduce real control-flow dependencies.  For the assignment operator
>>> this isn't need.
>>>
>>> Zhongxing: I don't think any of the existing cases in that method need to
>>> be modified to use VisitStmt() instead of addStmt(), or do you see
>>> something?
>>>
>>
>> I suggest the following implementation of addStmt.
>>
>> CFGBlock *addStmt(Stmt *S) {
>>     return Visit(S, AddStmtChoice::AlwaysAdd);
>> }
>>
>>
>> That would break a fair number of the existing callers, as some use the
>> second argument to indicate that the expression should be treated as an
>> lvalue.
>>
>>
>> Maybe those could use VisitStmt directly?
>
>
> Hmm.  Maybe they all should then, and remove addStmt entirely?
>

Make sense. Now we have 4 choices when visit a stmt. So there leaves not
much point for addStmt().
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