[PATCH] function try block handler redeclarations

[Aaron Ballman]

On Thu, May 29, 2014 at 10:50 PM, Richard Smith <richard at metafoo.co.uk> wrote:
> On Tue, May 27, 2014 at 6:57 AM, Aaron Ballman <aaron at aaronballman.com>
> wrote:
>>
>> The exception-declaration for a function-try-block cannot redeclare a
>> function parameter. One of our existing test cases was XFAILed because
>> of this. This patch is an attempt to fix the issue and un-XFAIL the
>> test.
>>
>> I am getting this from [basic.lookup.unqual]p15, which says,
>>
>> A name used in the handler for a function-try-block (Clause 15) is
>> looked up as if the name was used in the outermost block of the
>> function definition. In particular, the function parameter names shall
>> not be redeclared in the exception-declaration nor in the outermost
>> block of a handler for the function-try-block.
>
>
> This looks like it might do the wrong thing for a function nested within
> another function:
>
> void f(int i) {
>   struct S {
>     void g() try {} catch (int i) {}; // shouldn't diagnose this, but I
> think you will
>   };
> }
>
> The way we generally handle this is in IdentifierResolver::isDeclInScope,
> and that's the right place for this fix. You should be able to detect a
> catch of a function try block by looking at the flags on the Scope.

That simplifies things, thank you for the information! New patch
attached, along with updated test case.

~Aaron
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