[cfe-dev] Patch for compilation on msvc

[Ted Kremenek]

On Feb 16, 2008, at 2:21 PM, Cédric Venet wrote:

> Mainly project change but also a few missing std include header and  
> one
> compiler bug (or not, I don't know what the standard say):
>
> for (GRExprEngine::null_iterator I=CheckerState->null_begin(),
>         E=CheckerState->null_end(); I!=E; ++I) {
>
>      const PostStmt& L = cast<PostStmt>((*I)->getLocation());
>      Expr* E = cast<Expr>(L.getStmt());
>
>      Diag.Report(FullSourceLoc(E->getExprLoc(),  
> Ctx.getSourceManager()),
>                  diag::chkr_null_deref_after_check);
>    }
>
> Not Expr* E who redefine E from the for initialization. Is it the same
> scope? The strangest thing was that MSVC didn't complain about  
> redefinition
> but seemed to ignore the Expr* E; definition and was thinking E was a
> null_iterator. Took me some time to understand the problem.

I'm not as adroit in interpreting the C99 standard as others, but I  
believe that one could interpret the prose of the standard to say that  
the loop condition has a different scope than the loop body, or at  
least variables declared in within the parentheses of "for(...)" are  
visible to the other expressions in the for(...) (variables declared  
in the loop body are not visible to subexpression representing the  
loop condition or the optional "increment" expression) (6.8.5.3):

The statement

   for ( clause-1 ;expression-2 ;expression-3 ) statement

behaves as follows: The expression "expression-2" is the controlling  
expression that is  evaluated before each execution of the loop body.  
The expression "expression-3" is evaluated as a void expression after  
each execution of the loop body. If clause-1is a declaration, the  
scope of any variables it declares is the remainder of the declaration  
and  the entire loop, including the other two expressions; it is  
reached in the order of execution before the first evaluation of the  
controlling expression.
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