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i am trying to compile several literate haskell (.lhs) files to a shared object (.so), and then to link it with a main written in c. The issue here, though, is that 2 of the files used to create the .so are template haskell. i followed the rules for compiling a .so with template haskell, which means that i did the following steps:
1. I compiled each .lhs files ,statically
2. Then i compiled them all second time dynamically.
3. I created the shared object from the object files i got from steps 1 & 2.
4. I compiled the main.c into main.o
5. I created an executable from steps 3 & 4.

there are 3 files from which the .so is created. Dep1.lhs, Dep2.lhs & Dep3.lhs, and a main written in c

when i compile makefile i get this message:

my_directory >> make all
rm -f *.o *.hi *.so *.dyn_hi *.dyn_o main
ghc -c Dep3.lhs -XTemplateHaskell -XForeignFunctionInterface -o Dep3.o
ghc -c Dep3.lhs -dynamic -XTemplateHaskell -fPIC -no-hs-main -XForeignFunctionInterface -o Dep3.dyn_o -osuf dyn_o -hisuf dyn_hi ghc -c Dep2.lhs -XTemplateHaskell -XForeignFunctionInterface -o Dep2.o
ghc -c Dep2.lhs -dynamic -XTemplateHaskell -fPIC -no-hs-main -XForeignFunctionInterface -o Dep2.dyn_o -osuf dyn_o -hisuf dyn_hi
ghc -c Dep1.lhs -XTemplateHaskell -XForeignFunctionInterface -o Dep1.o

Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done.
Loading package base ... linking ... done.
Loading package pretty-1.1.1.0 ... linking ... done.
Loading package array-0.4.0.1 ... linking ... done.
Loading package deepseq-1.3.0.1 ... linking ... done.
Loading package containers-0.5.0.0 ... linking ... done.
Loading package template-haskell ... linking ... done.
ghc -c Dep1.lhs -dynamic -XTemplateHaskell -fPIC -no-hs-main -XForeignFunctionInterface -o Dep1.dyn_o -osuf dyn_o -hisuf dyn_hi
Loading package ghc-prim ... linking ... done.
Loading package integer-gmp ... linking ... done.
Loading package base ... linking ... done.
Loading package pretty-1.1.1.0 ... linking ... done.
Loading package array-0.4.0.1 ... linking ... done.
Loading package deepseq-1.3.0.1 ... linking ... done.
Loading package containers-0.5.0.0 ... linking ... done.
Loading package template-haskell ... linking ... done.
ghc -O2 -dynamic -shared -fPIC Dep1.dyn_o Dep2.dyn_o Dep3.dyn_o -o libShared.so -lHSrts-ghc7.6.3
gcc -O2 -I/usr/local/lib/ghc-7.6.3/include -L/usr/local/lib/ghc-7.6.3 -L/usr/local/lib/ghc-7.6.3/template-haskell-2.8.0.0/ -c Main.c -o main.o
gcc -o main main.o -L/usr/local/lib/ghc-7.6.3 -L/usr/local/lib/ghc-7.6.3/template-haskell-2.8.0.0/ -L. -lShared -Wl,-rpath,/usr/local/lib/ghc-7.6.3 -L/home/tal/a_prerequisites/new_haskell/ghc-7.6.3/libraries/base/dist-install/build/libHSbase-4.6.0.1-ghc7.6.3. -lHStemplate-haskell-2.8.0.0
/usr/bin/ld: dynamic variable `ghczmprim_GHCziTypes_True_closure' is zero size

/usr/bin/ld: dynamic variable `ghczmprim_GHCziTypes_ZMZN_closure' is zero size

/usr/bin/ld: /usr/local/lib/ghc-7.6.3/template-haskell-2.8.0.0//libHStemplate-haskell-2.8.0.0.a(Syntax__1744.o)(.text+0x77): unresolvable R_X86_64_32 relocation against symbol `ghczmprim_GHCziTypes_True_closure'

/usr/bin/ld: /usr/local/lib/ghc-7.6.3/template-haskell-2.8.0.0//libHStemplate-haskell-2.8.0.0.a(Lib__228.o)(.text+0x14): unresolvable R_X86_64_32S relocation against symbol `ghczmprim_GHCziTypes_ZMZN_closure'

/usr/bin/ld: /usr/local/lib/ghc-7.6.3/template-haskell-2.8.0.0//libHStemplate-haskell-2.8.0.0.a(Lib__137.o)(.text+0x14): unresolvable R_X86_64_32S relocation against symbol `ghczmprim_GHCziTypes_ZMZN_closure'

/usr/bin/ld: /usr/local/lib/ghc-7.6.3/template-haskell-2.8.0.0//libHStemplate-haskell-2.8.0.0.a(Lib__227.o)(.text+0x14): unresolvable R_X86_64_32S relocation against symbol `ghczmprim_GHCziTypes_ZMZN_closure'

/usr/bin/ld: /usr/local/lib/ghc-7.6.3/template-haskell-2.8.0.0//libHStemplate-haskell-2.8.0.0.a(Lib__124.o)(.text+0x14): unresolvable R_X86_64_32S relocation against symbol `ghczmprim_GHCziTypes_ZMZN_closure

and an executable 'main' is created, but when i try to run it, the following occurs:

host113@/home/tal/Documents/mfbus >> main
main: error while loading shared libraries: libHSbase-4.6.0.1-ghc7.6.3.so: cannot open shared object file: No such file or directory

i tried to include in the last rule (main) the directory of ' libHSbase-4.6.0.1-ghc7.6.3.so' in the '-l' option so that it will load it.but it doesnt seem to work. May someone have an insight to the error?

the code for Dep1.lhs: 

> {-# LANGUAGE TemplateHaskell #-} <br/>
> {-# LANGUAGE ForeignFunctionInterface #-} <br/>

> module Dep1 where

> import Foreign <br/>
> import Foreign.C.Types <br/>
> import Dep3 <br/>

> data MyData = MyData
>    { foo :: String
>    , bar :: Int
>    }

> emptyShow ''MyData

> foreign export ccall some_func :: IO () <br/>
> foreign export ccall factorial :: Int -> Int

> some_func :: IO () <br/>
> some_func = print $ MyData { foo = "bar", bar = 5 }

> factorial :: Int -> Int <br/>
> factorial 0 = 1  <br/>
> factorial n = n *(factorial $ n - 1)

the code for Dep3.lhs (comes here because Dep1.lhs imports it):

> {-# LANGUAGE TemplateHaskell, FlexibleInstances #-}

> module Dep3 where

> import Language.Haskell.TH

> emptyShow :: Name -> Q [Dec] <br/>
> emptyShow name = [d|instance Show $(conT name) where show _ = "some meaningful sentence"|]

the code for Dep2.lhs:

> {-# LANGUAGE ForeignFunctionInterface #-}

> module Dep2 where <br/>

> import Foreign    <br/>
> import Foreign.C.Types

> foreign export ccall power :: CInt -> CInt

> power :: CInt -> CInt
> power n = n*n

the code for Main.c: 

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <HsFFI.h>

#ifdef __GLASGOW_HASKELL__
#include "Tal2_stub.h"
#endif

#ifdef __GLASGOW_HASKELL__
extern void __stginit_power ( void );
#endif

// int power(int i){ return i*i; }

int fact(int i){
  if (i == 0) return 1;
  else return i * fact(i-1);
}
nt main(int argc, char *argv[]){
  hs_init(&argc, &argv);

#ifdef __GLASGOW_HASKELL__
  hs_add_root(__stginit_power);
#endif

 printf("what is 5!?\n");
 char buf[2048];
 scanf("%s",buf);
 int x = atoi(buf);
 if(x == fact(5)){
   printf("You're right!\n");
 } else {
   printf("You're wrong!\n");
 }
 printf("what is the power of 2?\n");
 scanf("%s",buf);
 x = atoi(buf);
 if(x == power(2)){
   printf("You're right!\n");
 } else {
   printf("You're wrong!\n");
 }
 hs_exit();
 return 0;
}

my makefile code: 

all : clean main

main : shared main.o
        gcc -o main main.o -L/usr/local/lib/ghc-7.6.3 -L/usr/local/lib/ghc-7.6.3/template-haskell-2.8.0.0/ -L. -lShared -Wl,-rpath,/usr/local/lib/ghc-7.6.3 -L/home/tal/a_prerequisites/new_haskell/ghc-7.6.3/libraries/base/dist-install/build/libHSbase-4.6.0.1-ghc7.6.3. -lHStemplate-haskell-2.8.0.0 

main.o : 
    gcc -O2 -I/usr/local/lib/ghc-7.6.3/include -L/usr/local/lib/ghc-7.6.3 -L/usr/local/lib/ghc-7.6.3/template-haskell-2.8.0.0/ -c Main.c -o main.o 

shared : dep3second dep2second dep1second
        ghc -O2 -dynamic -shared -fPIC Dep1.dyn_o Dep2.dyn_o Dep3.dyn_o -o    libShared.so -lHSrts-ghc7.6.3

dep1second : dep1first
    ghc -c Dep1.lhs -dynamic -XTemplateHaskell -fPIC -no-hs-main -XForeignFunctionInterface -o Dep1.dyn_o -osuf dyn_o -hisuf dyn_hi   

dep2second : dep2first
    ghc -c Dep2.lhs -dynamic -XTemplateHaskell -fPIC -no-hs-main -XForeignFunctionInterface -o Dep2.dyn_o -osuf dyn_o -hisuf dyn_hi

dep3second: dep3first
    ghc -c Dep3.lhs -dynamic -XTemplateHaskell -fPIC -no-hs-main    -XForeignFunctionInterface -o Dep3.dyn_o -osuf dyn_o -hisuf dyn_hi

dep1first :
    ghc -c Dep1.lhs -XTemplateHaskell -XForeignFunctionInterface -o Dep1.o  

dep2first :
    ghc -c Dep2.lhs -XTemplateHaskell -XForeignFunctionInterface -o Dep2.o

dep3first :
    ghc -c Dep3.lhs -XTemplateHaskell -XForeignFunctionInterface -o Dep3.o

.PHONY : clean
clean :
    -rm -f *.o *.hi *.so *.dyn_hi *.dyn_o main
user3110305
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1 Answers1

1

Note: my knowledge of Haskell is limited and this answer doesn't assume anything about Haskell at all.

The error says:

<executable>: error while loading shared libraries: <shared lib>.so: cannot open shared object file: No such file or directory

which means that when trying to execute your program, the shared object wasn't found. Note the difference between finding the shared object during link and during execution.

Roughly speaking, when you use -L and -l to link to a shared object, the link is not completely done, but remembered to be done at runtime. When you execute the executable that depends on that shared object, somebody else (not the compiler) must be able to find the shared object and do the linking: again roughly speaking, Linux.

So you need to have Linux find your shared object too. There are several ways to do so, some of which are deprecated. The way I would recommend is to write a file with the path of the shared object and put it under /etc/ld.so.conf.d/. Then, execute ldconfig as root (e.g. with sudo) and Linux should be able to find the shared object.

I haven't tested this, but if you just edit /etc/ld.so.conf and add a line containing ., the Linux should be able to find the shared object if it's located in the same directory the executable is being executed from. This could be ok for development, but I would not recommend it if the shared object is to be installed.

Shahbaz
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