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Re: Why are GCC Internals not Specification Driven ?
On Sun, Dec 18, 2016 at 11:49 PM, NightStrike <nightstrike@gmail.com> wrote:
> On Sun, Dec 18, 2016 at 11:37 AM, Andrew Haley <aph@redhat.com> wrote:
>> On 18/12/16 02:33, Seima Rao wrote:
>>> Precisely, stuffs like GENERIC, GIMPLE, RTL, gas(inline assembly),
>>> GCC extensions internals, ... and gnu's own debugging tied to gcc
>>> (if such exist nowadays), ... are not documented in a specification
>>> driven way.
>>
>> That's interesting. Can you explain what you mean by a specification-
>> driven way?
>
> I believe he's referring to top down system design, where you start
> from requirements (a la IEEE 830 or IEEE 29148), make design documents
> that meet those requirements, model them with something like IEEE 1016
> (which is basically UML), and only at the end provide implementation.
> On GCC, the implementation tends to come earlier in the process. At
> least, there's probably no UML representation of GCC's design.
I was referring to one of three approaches:
i) Write a Specification document and a matching testsuite
ii) Document _all_ data and code together with file formats
(e.g. dumps).
iii) Both (i) & (ii)
(i) is easy
(ii) is difficult
(iii) doesnt sell the product well
Sincerely,
Seima Rao.