[GHC] #12664: System.Environment.withArgs and friends leak memory

[GHC]

#12664: System.Environment.withArgs and friends leak memory
-------------------------------------+-------------------------------------
           Reporter:  simonmar       |             Owner:
               Type:  bug            |            Status:  new
           Priority:  normal         |         Milestone:  8.0.2
          Component:                 |           Version:  8.0.1
  libraries/base                     |
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  None/Unknown
  Unknown/Multiple                   |
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
-------------------------------------+-------------------------------------
 `ArgvLeak.hs`:

 {{{
 import System.Environment

 main :: IO ()
 main = withArgs ["a","b","c"] $ return ()
 }}}

 repro:

 {{{
 > ghc ArgvLeak.hs
 [1 of 1] Compiling Main             ( ArgvLeak.hs, ArgvLeak.o )
 Linking ArgvLeak ...
 > valgrind --leak-check=full ./ArgvLeak
 ==27227== Memcheck, a memory error detector
 ==27227== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al.
 ==27227== Using Valgrind-3.11.0 and LibVEX; rerun with -h for copyright
 info
 ==27227== Command: ./ArgvLeak
 ==27227==
 ==27227== Warning: set address range perms: large range [0x200000000,
 0x600100000) (noaccess)
 ==27227==
 ==27227== HEAP SUMMARY:
 ==27227==     in use at exit: 107 bytes in 9 blocks
 ==27227==   total heap usage: 62 allocs, 53 frees, 60,175 bytes allocated
 ==27227==
 ==27227== 55 (40 direct, 15 indirect) bytes in 1 blocks are definitely
 lost in loss record 6 of 6
 ==27227==    at 0x4C2FB55: calloc (in /usr/lib/valgrind
 /vgpreload_memcheck-amd64-linux.so)
 ==27227==    by 0x470057: stgCallocBytes (RtsUtils.c:107)
 ==27227==    by 0x4652C1: copyArgv (RtsFlags.c:1811)
 ==27227==    by 0x465FAE: setProgArgv (RtsFlags.c:1877)
 ==27227==    by 0x41CC4A: base_SystemziEnvironment_zdLr7BcsetProgArgv_info
 (in /home/smarlow/scratch/ArgvLeak)
 ==27227==
 ==27227== LEAK SUMMARY:
 ==27227==    definitely lost: 40 bytes in 1 blocks
 ==27227==    indirectly lost: 15 bytes in 4 blocks
 ==27227==      possibly lost: 0 bytes in 0 blocks
 ==27227==    still reachable: 52 bytes in 4 blocks
 ==27227==         suppressed: 0 bytes in 0 blocks
 ==27227== Reachable blocks (those to which a pointer was found) are not
 shown.
 ==27227== To see them, rerun with: --leak-check=full --show-leak-kinds=all
 ==27227==
 ==27227== For counts of detected and suppressed errors, rerun with: -v
 ==27227== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12664>
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