Building XFree86 for Raspberry Pi Zero - Problem with Includes

[Computer Nerd Kev]

First, yes I have heard of X.Org. Unfortunately its changelog shows
that they removed the XAA subsystem, saying that it had been broken
for some unspecified period of time before that as well. I
specifically want to use/hack XAA, so I want to start with code
where it's working from the outset, hence XFree86.

As XFree86 supports building on 32bit ARM, I thought building on a
Pi Zero running RPi OS 10 would be... Well not easy, but I wasn't
expecting this. So far I haven't got past the makedepend stage.

The main problem is that I haven't been able to find a good place
for setting extra system include directories to be checked by
makedepend (more "-I<dir>" options). I tried adding PreIncDir and
ExtraIncDir defines in config/cf/linux.cf, based on other
config/cf/*.cf files, but that did nothing. So it fails to find
a whole heap of header files that _aren't_ in /usr/include (or the
right position therein).

I'm also a bit unclear about which directories should be looked in
for those headers. I've found various headers (often multiple files
with the same name) that it complains are missing in:
/usr/include/arm-linux-gnueabihf
/usr/src/linux-headers-5.4.51+
/usr/lib/gcc/arm-linux-gnueabihf/8/include

But there's also issues with it looking for includes such as
"asm/mmiowb.h" which actually are only found in eg.
"asm-generic/mmiowb.h" or "generated/asm/mmiowb.h" (which just
includes "asm-generic/mmiowb.h").

I've been having some apparent success by adding symlinks to other
system include directories in xc/exports/include, then running "make
Everything" (the links there all get deleted when you do a "make
World"). But the problems I'm having now are screaming that I'm
doing it the wrong way, with "conflicting type" errors and an
apparantly broken macro, etc.

So my key questions are:

1. Where do I specifiy additional include paths to be passed to
imake/makedepend when I do a "make World" for XFree86?

2. Am I including headers from the right directories? Or is there
another kernel header package that I need to install (currently
I've just got raspberrypi-kernel-headers)?

Here's a bit from the end of the compile log where the build
currently fails, giving an example of the multiple problems from
the kernel header includes (the build has got a lot further than
this before, but then it reports lots of "cannot find include
file" warnings, and eventually dies with "Floating point exception"
after:
"
../../../../../config/makedepend/makedepend: warning: mmapr.c
(reading ../../../../../exports/include/linux/jiffies.h), line 42:
# error Invalid value of HZ.
"
, and adding symlinks in xc/exports/include to fix that leads to
this):


../../exports/include/linux/types.h:26:26: error: conflicting types for 'timer_t
'
typedef __kernel_timer_t timer_t;
^~~~~~~
In file included from ../../exports/include/sys/types.h:130,
from /usr/include/stdlib.h:394,
from imake.c:154:
../../exports/include/bits/types/timer_t.h:7:19: note: previous declaration of '
timer_t' was here
typedef __timer_t timer_t;
^~~~~~~
In file included from ../../exports/include/linux/limits.h:6,
from ../../exports/include/bits/local_lim.h:38,
from ../../exports/include/bits/posix1_lim.h:161,
from /usr/include/limits.h:183,
from /usr/lib/gcc/arm-linux-gnueabihf/8/include-fixed/limits.h:
194,
from /usr/lib/gcc/arm-linux-gnueabihf/8/include-fixed/syslimits.h:7,
from /usr/lib/gcc/arm-linux-gnueabihf/8/include-fixed/limits.h:34,
from imake.c:255:
../../exports/include/linux/types.h:131:13: error: conflicting types for 'blkcnt_t'
typedef u64 blkcnt_t;
^~~~~~~~
In file included from /usr/include/stdlib.h:394,
from imake.c:154:
../../exports/include/sys/types.h:209:20: note: previous declaration of 'blkcnt_t' was here
typedef __blkcnt_t blkcnt_t; /* Type to count number of disk blocks. */
^~~~~~~~
In file included from ../../exports/include/bits/local_lim.h:38,
from ../../exports/include/bits/posix1_lim.h:161,
from /usr/include/limits.h:183,
from /usr/lib/gcc/arm-linux-gnueabihf/8/include-fixed/limits.h:194,
from /usr/lib/gcc/arm-linux-gnueabihf/8/include-fixed/syslimits.h:7,
from /usr/lib/gcc/arm-linux-gnueabihf/8/include-fixed/limits.h:34,
from imake.c:255:
../../exports/include/bits/xopen_lim.h:99:5: error: missing binary operator before token "("
#if INT_MAX == 32767
^~~~~~~
../../exports/include/bits/xopen_lim.h:102:5: error: missing binary operator before token "("
#if INT_MAX == 2147483647
^~~~~~~
../../exports/include/bits/xopen_lim.h:126:5: error: missing binary operator before token "("
#if LONG_MAX == 2147483647
^~~~~~~~
make[2]: *** [<builtin>: imake.o] Error 1

--
__ __
#_ < |\| |< _#

[Computer Nerd Kev]

In comp.sys.raspberry-pi Computer Nerd Kev <n...@telling.you.invalid> wrote:
>
> The main problem is that I haven't been able to find a good place
> for setting extra system include directories to be checked by
> makedepend (more "-I<dir>" options). I tried adding PreIncDir and
> ExtraIncDir defines in config/cf/linux.cf, based on other
> config/cf/*.cf files, but that did nothing.

It turns out the makedpend executable wasn't getting recompiled,
and the include paths are actually compiled into it, so that's why
the changes to linux.cf weren't doing anything.

> I'm also a bit unclear about which directories should be looked in
> for those headers. I've found various headers (often multiple files
> with the same name) that it complains are missing in:
> /usr/include/arm-linux-gnueabihf
> /usr/src/linux-headers-5.4.51+
> /usr/lib/gcc/arm-linux-gnueabihf/8/include

"gcc -xc -E -v -" shows default include paths that GCC would use.
"/usr/src/linux-headers-5.4.51+" isn't among them, but I got past
the makedepend stage by adding header paths to lib/Xaw6/Imakefile.
But then it started with compiler errors about wrong types, etc.

It seems those problems are all in lib/Xaw/OS.c which includes
<asm/page.h> as a fall-back method of determining the page size.
This include has been commented out in the X.Org version of the
file:
https://gitlab.freedesktop.org/xorg/lib/libxaw/-/blob/master/src/OS.c
so I just did that too and it worked (plus it no longer needs the
extra include paths in lib/Xaw6/Imakefile).

Actually it's still compiling now, but it got me further at the
very least... Now it's stopped in lib/GLU/libnurbs/internals with
a bunch of compiler errors related to this first one:

"In file included from arc.cc:49:
simplemath.h:56:13: error: 'REAL abs(REAL)' conflicts with a
previous declaration
abs( REAL x ) { return ( x < 0.0 ) ? -x : x; }
^
"

Removing the "#if" around this in
extras/ogl-sample/main/gfx/lib/glu/libnurbs/internals/simplemath.h
"#if defined(_SCO_DS) || defined(__SCO__)
#define abs __gluabs
#endif
"
seems to fix that. Looks like I might get there eventually...

[Eli the Bearded]

In comp.windows.x, Computer Nerd Kev <n...@telling.you.invalid> wrote:
> It turns out the makedpend executable wasn't getting recompiled,
> and the include paths are actually compiled into it, so that's why
> the changes to linux.cf weren't doing anything.

Heh. Computers are so thoughtful.

[snip tales of stumbling blocks]

> seems to fix that. Looks like I might get there eventually...

Sounds like fun times.

Elijah
------
coercing something to compile can be so satisfying