[GHC] #7411: Exceptions are optimized away in certain situations

[GHC]

#7411: Exceptions are optimized away in certain situations
-------------------------------------+-------------------------------------
        Reporter:  SimonHengel       |                Owner:  tdammers
            Type:  bug               |               Status:  new
        Priority:  high              |            Milestone:  8.8.1
       Component:  Compiler          |              Version:  7.6.1
      Resolution:                    |             Keywords:  seq, deepseq,
                                     |  evaluate, exceptions
Operating System:  Linux             |         Architecture:  x86_64
                                     |  (amd64)
 Type of failure:  Incorrect result  |            Test Case:
  at runtime                         |  simplCore/should_fail/T7411
      Blocked By:                    |             Blocking:
 Related Tickets:  #5129 #15225      |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by tdammers):

 Did 4 full runs of compiling GHC from scratch and then compiling and
 running nofib, with different configurations. Here's what happened.

 1. "vanilla": compile everything normally (the `prof` build that comes
 with GHC). Everything works as expected.
 2. "nsh": compile everything with `-fno-state-hack` (GHC itself,
 libraries, nofib). Everything works as expected.
 3. "stage1": compile GHC normally, nofib with `-fno-state-hack`, but use
 stage1 compiler instead of stage2. Everything works as expected.
 4. "nofib-nsh": compile GHC normally, nofib with `-fno-state-hack`. GHC
 segfaults while compiling `Main.hs` from the bernouilli program (which
 simply happens to be the first one it encounters). Despite passing
 `-dcore-lint`, I get no linter output.

 Here's the log:

 {{{
 ------------------------------------------------------------------------
 == Recursively making `all' in runstdtest nofib-analyse imaginary spectral
 real shootout ...
 PWD = /home/tobias/well-typed/devel/ghc/HEAD/nofib
 ------------------------------------------------------------------------
 ------------------------------------------------------------------------
 == make all ;
  in /home/tobias/well-typed/devel/ghc/HEAD/nofib/runstdtest
 ------------------------------------------------------------------------
 rm -f -f runstdtest
 echo '#!/usr/bin/perl'                               >> runstdtest
 echo '$RM             = "rm -f";'             >> runstdtest
 echo '$CONTEXT_DIFF   = "diff -U 1";'   >> runstdtest
 cat runstdtest.prl                                >> runstdtest
 chmod +x runstdtest
 Finished making all in runstdtest: 0
 ------------------------------------------------------------------------
 == make all ;
  in /home/tobias/well-typed/devel/ghc/HEAD/nofib/nofib-analyse
 ------------------------------------------------------------------------
 make[1]: Nothing to be done for 'all'.
 Finished making all in nofib-analyse: 0
 ------------------------------------------------------------------------
 == make all ;
  in /home/tobias/well-typed/devel/ghc/HEAD/nofib/imaginary
 ------------------------------------------------------------------------
 ------------------------------------------------------------------------
 == Recursively making `all' in bernouilli digits-of-e1 digits-of-e2 exp3_8
 gen_regexps integrate paraffins primes queens rfib tak wheel-sieve1 wheel-
 sieve2 x2n1 kahan ...
 PWD = /home/tobias/well-typed/devel/ghc/HEAD/nofib/imaginary
 ------------------------------------------------------------------------
 ------------------------------------------------------------------------
 == make all --no-print-directory;
  in /home/tobias/well-typed/devel/ghc/HEAD/nofib/imaginary/bernouilli
 ------------------------------------------------------------------------
 HC = /home/tobias/well-typed/devel/ghc/HEAD/inplace/bin/ghc-stage2
 HC_OPTS = -O2 -Rghc-timing -H32m -hisuf hi -fno-state-hack -O2 -dcore-lint
 -rtsopts
 RUNTEST_OPTS = -ghc-timing
 ==nofib== bernouilli: time to compile Main follows...
 /home/tobias/well-typed/devel/ghc/HEAD/inplace/bin/ghc-stage2 -O2 -Rghc-
 timing -H32m -hisuf hi -fno-state-hack -O2 -dcore-lint -rtsopts -c Main.hs
 -o Main.o
 ../../mk/suffix.mk:23: recipe for target 'Main.o' failed
 make[2]: *** [Main.o] Segmentation fault (core dumped)
 Failed making all in bernouilli: 1
 ../mk/ghc-recurse.mk:65: recipe for target 'all' failed
 make[1]: *** [all] Error 1
 Failed making all in imaginary: 1
 mk/ghc-recurse.mk:65: recipe for target 'all' failed
 make: *** [all] Error 1
 }}}

 Unfortunately I hadn't done a run with GHC stage1 compiled with `-fno-
 state-hack`; I'll do that next.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7411#comment:41>
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