Re: Bootstraping compilers ?

I think it is very beneficial to have a compiler be able to compile
itself.  It is an excellent test of the quality of the compiler.  (I
suggest starting with the C99 compiler written in C89, then migrate
the source to C99 when you have a functioning C99 compiler.)

Do not stop at simply compiling, but also using the resulting compiler to
compile itself again and again and again.
I suggest at least 3 generations of compiles.  Some say you should need 5
generations.
1st - finds compile-time errors
2nd - finds run-time errors
3rd - finds errors where the compiler ran improperly
4th - finds errors where the program ran correctly, but produced incorrect
results
5th - ?

The 3rd generation bugs are the hardest to find and diagnose.  I think
I've fixed one or two 4th generation bugs, but I've never seen a 5th
generation bug.  The exercise is well worth the effort.

Damian Thomas
Not speaking for my employer.


"Paulo Jorge de O. C. de Matos" <pocm@[EMAIL PROTECTED]
> wrote in message
> itself. gcc for example seems to do it, but is this good practice or
> should this always happen?