[P4-dev] typedef, P4-16 & p4c compiler

Andy Fingerhut andy.fingerhut at gmail.com
Thu Jun 8 20:52:09 EDT 2017


I believe the string "header" is a keyword in P4-16, and probably cannot be
the name of a type.

You can define a header type with name "ipv4_t", and then typedef another
type name to be the same as that one like so:

header ipv4_t {
    // your fields here
}
typedef ipv4_t another_type_name_t;

then use 'another_type_name_t' any place that you would otherwise use
'ipv4_t'.

Andy

On Thu, Jun 8, 2017 at 1:42 PM, <hemant at mnkcg.com> wrote:

> typedef header foo_t;
>
>
>
> *From:* Mihai Budiu [mailto:mbudiu at vmware.com]
> *Sent:* Thursday, June 08, 2017 4:40 PM
> *To:* hemant at mnkcg.com; 'p4-dev' <p4-dev at lists.p4.org>
> *Subject:* RE: typedef, P4-16 & p4c compiler
>
>
>
> Can you post a code fragment (even if it does not work) showing what you
> want to achieve?
>
>
>
> Mihai
>
>
>
> *From: *hemant at mnkcg.com
> *Sent: *Thursday, June 8, 2017 1:19 PM
> *To: *'p4-dev' <p4-dev at lists.p4.org>
> *Cc: *Mihai Budiu <mbudiu at vmware.com>
> *Subject: *typedef, P4-16 & p4c compiler
>
>
>
> If C preprocessing is supported in P4, including P4-16, is the P4-16
> “header” possible to be typedefed?  I am not sure what the type is because
> the header is in the P4 library.  If a C preprocessor allows any C type
> such as “int” to be typdefed, why not the P4-16 header?
>
>
>
> Thanks,
>
>
>
> Hemant
>
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> P4-dev mailing list
> P4-dev at lists.p4.org
> http://lists.p4.org/mailman/listinfo/p4-dev_lists.p4.org
>
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