[cfe-dev] #define keyword

[Seth Cantrell]

Correction, that's 17.6.4.3.1.

On Jun 20, 2013, at 12:53 PM, Seth Cantrell <seth.cantrell at gmail.com> wrote:

> C++11 [macro.names] 17.6.6.3.1 p2 states
>
>> A translation unit shall not #define or #undef names lexically identical to keywords, to the identifiers listed in Table 3, or to the attribute-tokens described in 7.6.
>
> As I understand it this means a program that does this is ill-formed,
> with a diagnostic required. Clang does not produce any diagnostics for
> such defines/undefs. Am I correct that a diagnostic is required? This
> doesn't sound like it would be too difficult to implement. Is there a
> reason not to have clang produce a warning for this (one that wouldn't
> trigger in system headers)?