Opened 7 months ago

Last modified 7 months ago

#9348 new bug

"Symbol not found" when using a shared library

Reported by: alex.davis Owned by: simonmar
Priority: normal Milestone:
Component: Runtime System Version: 7.8.3
Keywords: Cc: simonmar
Operating System: MacOS X Architecture: x86
Type of failure: None/Unknown Test Case:
Blocked By: Blocking:
Related Tickets: Differential Revisions:

Description (last modified by alex.davis)

I'm trying to make a shared library from a simple program. It works fine on my Windows box, but gives an error on Mac OS X. Furthermore, the error seems to be generated from one of GHC's shared libraries.

What happens is this. I compile my shared library with GHC, which works fine. But when I try to use it from another program (specifically, R), I get an error message containing the following:
Symbol not found: _stg_IND_STATIC_info

Referenced from: /usr/local/lib/ghc-7.8.3/ghc-prim-0.3.1.0/libHSghc-prim-0.3.1.0-ghc7.8.3.dylib
Expected in: flat namespace

in /usr/local/lib/ghc-7.8.3/ghc-prim-0.3.1.0/libHSghc-prim-0.3.1.0-ghc7.8.3.dylib

More details:
The program I'm trying to use is R. In R, you load a shared library with the command "dyn.load". When I try this, the command I use is "dyn.load('final.dylib')", and the full error message is what follows:
---
Error in dyn.load("final.dylib") :

unable to load shared object '/Users/alexanderdavis/Desktop/illustrate bug copy/final.dylib':
dlopen(/Users/alexanderdavis/Desktop/illustrate bug copy/final.dylib, 6): Symbol not found: _stg_IND_STATIC_info
Referenced from: /usr/local/lib/ghc-7.8.3/ghc-prim-0.3.1.0/libHSghc-prim-0.3.1.0-ghc7.8.3.dylib
Expected in: flat namespace

in /usr/local/lib/ghc-7.8.3/ghc-prim-0.3.1.0/libHSghc-prim-0.3.1.0-ghc7.8.3.dylib

---

As I said, I have done all of this with no trouble on Windows. I compiled into a DLL, loaded the program into R, and was able to use the functions in it. However, on Windows I was also using an older version of GHC, and may have used the Haskell Platform and thus had more libraries installed - I don't have the computer with me, so I'm not sure.

My Mac OS version is 10.9.4.

My R version is 3.0.2. When loaded, it displays "Platform: x86_64-apple-darwin10.8.0 (64-bit)", but Sys.getev("R_ARCH") returns the empty string.

Command used for compiler:
ghc --make -dynamic -fPIC -shared SumRoots.hs StartEnd.c -o final.dylib

The code is attached. It is from a blog post by Neil Mitchelll (author of HLint) about calling Haskell from R: http://neilmitchell.blogspot.com/2011/10/calling-haskell-from-r.html

Attachments (3)

SumRoots.hs (396 bytes) - added by alex.davis 7 months ago.
Simple Haskell program
StartEnd.c (246 bytes) - added by alex.davis 7 months ago.
C code to start the runtime environment
errorFromC.c (214 bytes) - added by alex.davis 7 months ago.

Download all attachments as: .zip

Change History (6)

Changed 7 months ago by alex.davis

Simple Haskell program

Changed 7 months ago by alex.davis

C code to start the runtime environment

comment:1 Changed 7 months ago by alex.davis

  • Description modified (diff)

comment:2 Changed 7 months ago by alex.davis

  • Description modified (diff)

Changed 7 months ago by alex.davis

comment:3 Changed 7 months ago 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 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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