From: hlu@yoda.eecs.wsu.edu (H.J. Lu)
Newsgroups: comp.os.linux
Subject: Answer: HELP!!!  _---GCC QUESTION---
Date: 29 Sep 92 08:29:02 GMT
Article-I.D.: serval.1992Sep29.082902.17019
Organization: Washington State University

In article <1a8pptINN1kb@matt.ksu.ksu.edu> gbh@matt.ksu.ksu.edu (Da Hubster!!!) writes:
>I just got linux installed onto my 486 and now want to 
>compile some things for it 
>
>My question is what is the name for the complete gcc compplier and
>any good locations to obtain it
>
>any help would be greatly thanked!!!!!
>
>
>gbh@matt.ksu.ksu.edu


QUESTION: What compiler should I use for Linux?

ANSWER: You should only use the same version on tsx-11.mit.edu or
fgb1.fgb.mw.tu-muenchen.de under /pub/linux/GCC. If you want to use
the testing release, first join the GCC channel on the Linux mailing
list, and then send a note to hlu@eecs.wsu.edu. Don't use gcc older
than the one on tsx-11.mit.edu or fgb1.fgb.mw.tu-muenchen.de.

QUESTION: Where is the latest official gcc 2.xx for Linux?

ANSWER: It's on tsx-11.mit.edu under /pub/Linux/GCC and
fgb1.fgb.mw.tu-muenchen.de under pub/linux/GCC. You may find it on the
other sites.

QUESTION: What are the contents of them?

ANSWER: Please read the current release note and ChangeLog for
details.

QUESTION: How do I install it?

ANSWER: Read README and release notes.

QUESTION: What are the main differences with the old release?

ANSWER: Read README and release notes.

QUESTION: Can I use the old version of gcc?

ANSWER: Please get rid of gcc older than gcc 2.2.2. Starting from
gcc 2.2.2, you can do

	gcc -V xxxx

where xxxx is the version number. Please read `release.xxxx' for
detail. There is one catch in gcc 2.2.2d, setjmp/longjmp is changed,
so the old header files is not compatible with gcc 2.2.2. Before you
install gcc 2.2.2d, please do

cp /usr/include/setjmp.h /usr/lib/gcc-lib/i386-linux/2.2.2/include

where /usr/include/setjmp.h is come with gcc 2.2.2.

QUESTION: Is stdio ANSI compatible?

ANSWER: Yes, please test it.

QUESTION: Is g++ in 2.xx?

ANSWER: Yes.

QUESTION: How do I use gcc?

ANSWER: Read manual page, gcc.ps or gcc.man in /usr/install/gcc2.

QUESTION: What options can I use for gcc?

ANSWER: Read manual page, gcc.ps or gcc.man. Also -static tells gcc
to use the static libraries, -nojump forces gcc to use the classic
shared libraries. The default is the jump table version of shared
libraries. The shared libraries for X are linked with the jump table
version of shared C library.

QUESTION: Where is the source code of the new libc.a?

ANSWER: The same place you find this file. It is called 
lib-src-yy.xx.TZ.

QUESTION: Why does g++ complain, even die?

ANSWER: You need "expr", which is in GNU shell utilities 1.6, echo (?)
and sed.

QUESTION: How do I generate code for 486?

ANSWER: Add -m486 to CFLAGS.

QUESTION: I heard malloc (0) wouldn't work with Linux, what should I
do?

ANSWER: It *does* work in a manner which POSIX allows; unfortunately,
pre-POSIX code frequently assumes that malloc(0) will not return
0 -- the standard version of malloc under Linux *does* return 0.
By including <stdlib.h>, you get a definition of malloc which behaves
more traditionally.  If you define NO_FIX_MALLOC, then you will get
the default (non-traditional) form.  If you are trying to develop POSIX
compliant code under Linux, you should probably define NO_FIX_MALLOC to
ensure that your code doesn't make assumptions about malloc() which
will not work on other systems.  (Note: NO_FIX_MALLOC is specific to
Linux.)

(Provided by Phil.Richards@prg.oxford.ac.uk. Thanks.)

QUESTION: Why does gcc say "xxxxx..h not found"?

ANSWER: see QUESTION: What are the contents of them?

QUESTION: I really followed every step in the documentation, but when
I do "make", why does it say "don't how to make xxxxxx"?

ANSWER: The dependency in Makefile is dated, you need to make a new
one. Please get some guide on make and read Makefile. For the kernel
sources, please do

cd src/linux
make dep

QUESTION: How do I compile programs under Linux?

ANSWER: The Linux C library is trying to be ANSI/POSIX compliant. It
is also very compatible with SYSV and BSD. The C library is loaded
with SYSV and BSD functions. There are three exceptions:

1. signal in Linux is POSIX.
2. tty in Linux is POSIX.
3. time functions are POSIX, plus a few BSD and SYSV extensions.
4. setjmp/longjmp functions are POSIX. But you can use -D__FAVOR_BSD
   to make it BSD or use sigsigjmp/siglongjmp.

When you compile a program under Linux, your best bet is include all
the appropriate header files and use -Wall. All the usable functions
and global variables are declared in the corresponding header files.
YOU SHOULD NOT DEFINE ANY functions or global variables OF THE LINUX C
LIBRARY IN YOUR CODE IF YOU WANT TO USE THE SHARED LIBRARIES.

After saying all those, you now should know you can compile a program
with -D_POSIX_SOURCE or -D_GNU_SOURCE (read <features.h> for details).
With a few modifications you can even use -DSYSV, -DUSG or -DBSD. Some
codes need to define -DSTDC_HEADERS for ANSI C compiler like gcc here.

To use malloc () and calloc () safely under Linux, please include

<stdlib.h> and don't define NO_FIX_MALLOC.

BTW, gcc -traditional should work with gcc 2.2.2d or above.

Please also read ChangeLog for the latest enhencement.

Please read the header files for details. Maybe you should get a book
on POSIX. Any suggestion of the book list?

From Steve Robbins  --  steve@nyongwa.cam.org

--------
I like "POSIX Programmer's Guide", by Donald Lewine.  Its essentially
a list of POSIX functions' man pages, with a very brief guide in the
beginning of a few things.  It's published by O'Reilly & Associates,
Inc.
--------
Newsgroups: comp.os.linux