[BUILDROBOT] Selftest failed for i686-wrs-vxworks

[David Malcolm]

On Thu, 2016-06-30 at 08:38 -0400, Nathan Sidwell wrote:
> Jan-Benedict,
> 
> > I haven't given it any additional manual testing so far. It's
> > pre-installation though. Maybe I'd just set WIND_BASE to some
> > arbitrary value, just to make xgcc pass it's initial start-up test
> > so
> > that it can continue with self-testing? Or shall we set some value
> > in gcc/Makefile.in for running the self-test?
> 
> As I recall, WIND_BASE is expected to point at a vxworks install to
> pick up 
> header files.  It is an error not to have it set (silently skipping
> it leads to 
> user confusion).
> 
> If that's irrelevant for this testing environment, then setting it to
> something 
> (probably just "", but safer might be 
> "/These.are.not.the.dirs.you.are.looking.for") should be fine.

Sorry about the breakage.

The error message appears to affect a few other targets within
gcc/Makefile.in.

For example:

$ make s-macro_list 
echo |  ./xgcc -B./ -B/usr/local/i686-wrs-vxworks/bin/ -isystem
/usr/local/i686-wrs-vxworks/include -isystem /usr/local/i686-wrs
-vxworks/sys-include -L/home/david/archive/huge/gcc-git-all
-configs/selftest-multi-mk/i686-wrs-vxworks/gcc/../ld -E -dM - | \
  sed -n -e 's/^#define \([^_][a-zA-Z0-9_]*\).*/\1/p' \
	 -e 's/^#define \(_[^_A-Z][a-zA-Z0-9_]*\).*/\1/p' | \
  sort -u > tmp-macro_list
xgcc: fatal error: environment variable ‘WIND_BASE’ not defined
compilation terminated.
/bin/sh /home/david/coding-3/gcc-git-unittests/src/gcc/../move-if
-change tmp-macro_list macro_list
cmp: EOF on tmp-macro_list
echo timestamp > s-macro_list


However the above issue doesn't fail the build:

$ echo $?
0

It can be trivially reproduced like this:

$ ./xgcc -B. -E -
xgcc: fatal error: environment variable ‘WIND_BASE’ not defined
compilation terminated.


It happens due to evaluating this spec function:
  "getenv(WIND_BASE /target/h)"
from this within gcc/config/vxworks.h:

/* Since we provide a default -isystem, expand -isystem on the command
   line early.  */
#undef VXWORKS_ADDITIONAL_CPP_SPEC
#define VXWORKS_ADDITIONAL_CPP_SPEC		\
 "%{!nostdinc:					\
    %{isystem*} -idirafter			\
    %{mrtp: %:getenv(WIND_USR /h)		\
      ;:    %:getenv(WIND_BASE /target/h)}}"


Hence it appears that passing "-nostdinc" as a param will avoid the
error:

$ echo | ./xgcc -B. -E - -nostdinc
# 1 "<stdin>"
# 1 "<built-in>"
# 1 "<command-line>"
# 1 "<stdin>"

$ echo $?
0

Presumably if you're explicitly building for vxworks you have a vxworks
install, so there is a meaningful value to set WIND_BASE to, whereas if
you don't have a vxworks install (and are merely building everything as
a smoketest), you presumably only want to build the "gcc" subdir, since
AFAIK you can't run then driver.

So there are at least 2 ways of fixing this:

(a) add "-nostdinc" when running the selftests i.e. to the invocations
of GCC_FOR_TARGET in the "s-selftest" and "selftest-gdb" clauses of
gcc/Makefile.in.
I've verified that this fixes the issue for --target=i686-wrs-vxworks.

(b) set WIND_BASE to a dummy value in contrib/config-list.mk (if not
already set) so that the vxworks targets are able to at least build all
of "gcc" without needing a vxworks install.


Thoughts?