Re: Building PCC for "tools" is broken (missing symbol __USE)- PCC bug or NetBSD source tree error?

["William D. Jones" <thor0505%comcast.net@localhost>]

-----Original Message----- 
From: Iain Hibbert
Sent: Saturday, July 19, 2014 1:33 PM
To: William D. Jones
Cc: current-users%netbsd.org@localhost
Subject: Re: Building PCC for "tools" is broken (missing symbol __USE)- PCC 
bug or NetBSD source tree error?

> it certainly is. I think I remember that __USE() now, it was a local
> (NetBSD) addition due to a set but unused variable, which is changed in
> upstream versions now.
Alright then. What do you suggest I do to reconcile the NetBSD version with 
the current upstream tree? Should I wait for the next major release of PCC, 
and then attempt to integrate the changes, or is there something I can do 
now (to start)?

> It does handle most of the NetBSD source tree lately, the main problems
> currently are things which GCC accepts (or encourages) which are not
> supported. Personally, I think it would be good for PCC to be able to
> build GCC, perhaps that would be enough compatibility.
I would be ecstatic to find another compiler that can compile GCC- even if 
only the first stage. It doesn't solve the difficult problem of finding a 
100% compatible GCC compiler that's not a nightmare to port, but it's a 
start.

> I have not tried application sources (eg pkgsrc) due to lack of time.
Join the club :P.

> I am not sure, but it may not.. predictably the GCC developers use GCC
> language features within their code, and these are not always supported. I
> have been concentrating on other things lately and have not tried to build
> GCC with PCC. At least I know that the binutils we have in tree won't
> build, as there is an unsupported feature which causes an error (restrict
> keyword in array declaration).
GCC 4.7.3 and below can in theory (emphasis on theory) be built with a pure 
ANSI C compiler that has a working libc. The first stage of GCC will use the 
host C compiler to build a cross-gcc from pure ANSI C. The cross-gcc can 
compile the remaining source code that relies on GCC's extensions. In 
practice, I have seen GCC 4.7.3 emit a number of warnings for 
standards-violating code when -pedantic is set.
For perspective, from my own experimentation, TinyCC is capable of compiling 
the cross-gcc which then builds the remaining extensions (with minor source 
code tweaks in 3 or so file)... sadly the cross-gcc segfaults :P, and I 
haven't had the time to figure out what goes wrong. So I don't think it's an 
impractical goal.

Versions above 4.7.3 sadly require a C++ compiler. Still, one could compile 
GCC 4.7.3 and use that to create the C++ compiler.

--
William D. Jones