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4953 :: [FFI] Reference xxx without definition

• mantielero (orginal) [2019-06-20T12:33:41+02:00] view original

  I am playing with nim FFI (newbie speaking). I am trying to wrap minizip for the sake of learning a bit. I have minizip installed under ArchLinux.

  What I have so far is:

  #proc fmi_zip_unzip*(zip_file_path: cstring; output_folder: cstring;
  #                   callbacks: ptr jm_callbacks): jm_status_enu_t
  #int unzip(const char *zipfilename, const char *dirname);
  {.deadCodeElim: on.}
  const libname = "/usr/lib/libminizip.so"
  
  #type
  #  unzFile* = pointer
  
  {.passl: gorge("pkg-config --cflags minizip") .}
  {.passc: gorge("pkg-config --cflags minizip") .}
  #{.push importc.}
  #{.push header:"unzip.h"}
  
  {.push dynlib:libname.}
  #unzFile ZEXPORT unzOpen64 OF((const void *path));
  #proc unzOpen64*(zipfilename: cstring): pointer #{.header:"<minizip-master/include/miniunz.h>".}
  proc unzOpen64*(zipfilename: cstring): pointer {.header:"unzip.h" importc:"unzOpen64"}
  {.pop.} # dynlib
  #{.pop.}
  #{.pop.} # importc
  
  #var error:cint
  #var uf:unzFile
  var uf = unzOpen64("./test.zip")
  Run

  And what I get is:

  $ nim c -r minizip2.nim
  ....
  minizip2.nim.c:(.text+0x20e): referencia a `unzOpen64' sin definir
  collect2: error: ld devolvió el estado de salida 1
  ....

  Which means something like unzOpen64 is a reference without a definition.

  Any clue about what am I doing wrong?

  Kind regards, José M.

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• yglukhov (orginal) [2019-06-20T14:40:34+02:00] view original

  This line looks wrong, should be --libs.

  {.passl: gorge("pkg-config --cflags minizip") .}
  Run

  Also header pragma is not required for C interop as long as you define the function signatures correctly.

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• mantielero (orginal) [2019-06-21T12:26:34+02:00] view original

  That worked. Thanks mate.

  For the record:

  {.deadCodeElim: on.}
  {.passl: gorge("pkg-config --libs minizip") .}
  {.passc: gorge("pkg-config --cflags minizip") .}
   
   proc unzOpen64*(zipfilename: cstring): pointer {. importc:"unzOpen64"}
   var uf = unzOpen64("./test.zip")
  Run

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