Re: [PATCH 2/2] dtc: cpp co-existence: add support for #line directives

On 09/25/2012 10:34 PM, David Gibson wrote:

On Mon, Sep 24, 2012 at 04:51:17PM -0600, Stephen Warren wrote:

quoted

From: Stephen Warren <redacted>

Line control directives of the following formats are supported:
    #line LINE "FILE"
    # LINE FILE [FLAGS]

This allows dtc to consume the output of pre-processors, and to provide
error messages that refer to the original filename, including taking
into account any #include directives that the pre-processor may have
performed.

I like the idea of handling line directives, whichever way we go with
the other cpp-related proposals.  The fact that these are
distinguished from a propnodename beginning with # only by the
following digits is more subtle than I'd ideally like, but I think
it's wirth it.

The only thing I would like to see change is to only recognize line
directives at the beginning of the line (in fact, preferably in column
0 only).  Unfortunately that is going to mean some mucky flex work,
including a new start state, I expect.

That turns out to be exceedingly easy; just put ^ at the start of the
regex (after the start state specification), and Flex takes care of
everything:-)