[GHC] #9348: "Symbol not found" when using a shared library

[GHC]

#9348: "Symbol not found" when using a shared library
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              Reporter:  alex.davis      |            Owner:  simonmar
                  Type:  bug             |           Status:  new
              Priority:  normal          |        Milestone:
             Component:  Runtime System  |          Version:  7.8.3
            Resolution:                  |         Keywords:
      Operating System:  MacOS X         |     Architecture:  x86
       Type of failure:  None/Unknown    |       Difficulty:  Unknown
             Test Case:                  |       Blocked By:
              Blocking:                  |  Related Tickets:
Differential Revisions:                  |
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Comment (by alex.davis):

 Shea Levy figured out the problem and its solution.

 First of all, its not a problem with R, you get the same error from C.
 I've attached Shea's C code, which I've titled "errorFromC.c". This code
 tries to load the Haskell shared library, which it assumes is named
 "test.dylib", and gives the same error as R.

 Second, the problem is solved by adding to the compilation the flag
 "-lHSrts-ghc7.8.3". This links the Haskell runtime system to the resulting
 file.
 (although, on my computer I still get errors due to the use if Int instead
 of CInt in the Haskell code. But the problem of not being able to access
 the Haskell code at all is solved.)

 This represents a mismatch between the behavior of the compiler and its
 documentation. People looking to make shared libraries will read
 [https://www.haskell.org/ghc/docs/latest/html/users_guide/using-shared-
 libs.html#idp12506320 section 4.13.3 of the GHC user's guide]. They will
 see "To build Haskell modules that export a C API into a shared library
 use the -dynamic, -fPIC and -shared flag". No mention of linking the
 runtime system. I'm not sure if this a problem with the compiler or the
 documentation, but either way it should be fixed.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9348#comment:3>
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