Faliure building unregistered GHC: pprGlobalReg: Unsupported register: CCCS

[nomeata]

Hi,

the 7.4.1 release candidate failed to build on arm; previous versions built fine. It would be great if arm support would not be dropped, if it can be helped:

"inplace/bin/ghc-stage1"   -H32m -O -lffi -optl-pthread -optc-mlong-calls    -package-name ghc-prim-0.2.0.0 -hide-all-packages -i -ilibraries/ghc-prim/. -ilibraries/ghc-prim/dist-install/build -ilibraries/ghc-prim/dist-install/build/autogen -Ilibraries/ghc-prim/dist-install/build -Ilibraries/ghc-prim/dist-install/build/autogen -Ilibraries/ghc-prim/.    -optP-include -optPlibraries/ghc-prim/dist-install/build/autogen/cabal_macros.h -package rts-1.0  -package-name ghc-prim -XHaskell98 -XCPP -XMagicHash -XForeignFunctionInterface -XUnliftedFFITypes -XUnboxedTuples -XEmptyDataDecls -XNoImplicitPrelude -O2  -no-user-package-conf -rtsopts     -odir libraries/ghc-prim/dist-install/build -hidir libraries/ghc-prim/dist-install/build -stubdir libraries/ghc-prim/dist-install/build -hisuf hi -osuf  o -hcsuf hc -c libraries/ghc-prim/dist-install/build/GHC/PrimopWrappers.hs -o libraries/ghc-prim/dist-install/build/GHC/PrimopWrappers.o
ghc-stage1: panic! (the 'impossible' happened)
  (GHC version 7.4.0.20111219 for arm-unknown-linux):
	pprGlobalReg: Unsupported register: CCCS

Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug

make[2]: *** [libraries/ghc-prim/dist-install/build/GHC/PrimopWrappers.o] Error 1

(Full log at  https://buildd.debian.org/status/fetch.php?pkg=ghc&arch=armel&ver=7.4.0.20111219-2&stamp=1324673390)

Thanks, Joachim on behalf of the Debian Haskell Team

[nomeata]

This bug, after fixing more trivial bugs, now appears on mips, s390(x), sparc, armel, but not on powerpc, i386 and amd64 – precisely the unregistered arches. So this does not seem to be arch-specific, but rather a general breakage of unregistered building.

[nomeata]

Judging from the logs, this might have been caused by this patch by Simon Marlow: [50de6034343abc93a7b01daccff34121042c0e7c]

[nomeata]

Yes, this is reproducible even on i386, e.g. with this mk/build.mk:

GhcLibWays = v

GhcUnregisterised    = YES
GhcWithNativeCodeGen = NO

SRC_HC_OPTS          = -O -H64m
GhcStage1HcOpts      = -O
GhcStage2HcOpts      = -O2
GhcHcOpts            = -Rghc-timing
GhcLibHcOpts         = -O2
SplitObjs            = NO
HADDOCK_DOCS         = NO
BUILD_DOCBOOK_HTML   = NO
BUILD_DOCBOOK_PS     = NO
BUILD_DOCBOOK_PDF    = NO
GhcLibWays     += p

# NoFib settings
NoFibWays =
STRIP_CMD = :

It would be helpful for us if you could include such a build in your automatic build tests.

[simonmar]

Thanks, I'll fix.

[simonmar]

Fixed:

commit d7d56f5852b975c865535495b45a8aba9a397c86

Author: Simon Marlow <marlowsd@gmail.com>
Date:   Tue Jan 3 16:21:41 2012 +0000

    Fix the C backend after making CCCS an STG register

[igloo]

Merged as f106b17347e6822b857b5ee3563b99b64d0a4c79