[GHC] #7097: linker fails to load package with binding to foreign library

[GHC]

#7097: linker fails to load package with binding to foreign library
--------------------------+-------------------------------------------------
 Reporter:  nus           |          Owner:                
     Type:  bug           |         Status:  new           
 Priority:  normal        |      Component:  Runtime System
  Version:  7.4.2         |       Keywords:                
       Os:  Windows       |   Architecture:  x86           
  Failure:  None/Unknown  |       Testcase:                
Blockedby:                |       Blocking:                
  Related:  2283          |  
--------------------------+-------------------------------------------------
Changes (by nus):

  * related:  => 2283


Comment:

 `WSACleanup` is declared `__declspec(dllimport)` in the MinGW CRT headers.
 That makes the object file to refer to `__imp__WSACleanup at 0`, to be
 resolved through a stub library of MinGW named `libws2_32.a`. `ws2_32` is
 mentioned in the `extra-libraries` field of the `network` package entry in
 the ghc package configuration database, so `-lws2_32` is added to the
 linker command arguments. From the linker documentation:
 {{{
      For instance, when ld is called with the argument `-lxxx' it will
      attempt to find, in the first directory of its search path,

           libxxx.dll.a
           xxx.dll.a
           libxxx.a
           xxx.lib
           cygxxx.dll (*)
           libxxx.dll
           xxx.dll

      before moving on to the next directory in the search path.
 }}}
 So the linker finds `libws2_32.a` in one of the search paths passed on on
 the command line (through the built-in gcc specs, cf.
 `link_gcc_c_sequence`).

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7097#comment:1>
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