I have been trying to use the dynamic loader package which I found from this question. I am very new to Haskell so excuse me if I am making some incredibly rookie mistakes. My problem is that when I attempt to use the resolveFunctions function I get the following error:
DyanmicLoad-exe: /home/ubuntu/DynamicLoadTest/Plugin.o: unknown symbol `ghczmprim_GHCziCString_unpackCStringzh_closure'
DyanmicLoad-exe: user error (Unable to resolve functions!)
I would love it if someone could tell me possibly where I am going wrong here.
Here is my code (I am using the basic stack new structure):
app/Main.hs
Just the main function.
module Main where
import Lib
main :: IO ()
main = libMain
src/Lib.hs
The module is loaded in here.
module Lib
( libMain
) where
import System.Plugins.DynamicLoader
import System.Directory
import Interface
libMain :: IO ()
libMain = do currentDir <- System.Directory.getCurrentDirectory
loadModuleFromPath (currentDir ++ "/Interface.o") Nothing
putStrLn "Loaded Interface"
loadedModule <- loadModuleFromPath (currentDir ++ "/Plugin.o") (Just currentDir)
putStrLn "Loaded Plugin Module!"
resolveFunctions
putStrLn "Resolved Functions"
plugin <- (loadFunction loadedModule "getPlugin") :: IO (JobInterface)
putStrLn "Loaded Plugin"
putStrLn (jobName plugin)
src/Interface.hs
This file is the "plugin interface"
module Interface (
JobInterface (..)
) where
data JobInterface =
JobInterface { jobName :: String
, runJob :: Int -> Int
}
src/Plugin.hs
An example plugin.
module Plugin (
getPlugin
) where
import Interface
getPlugin :: JobInterface
getPlugin = JobInterface "Hello" $ \x -> 1 * x
I am building with stack build followed by stack ghc src/Plugin.hs src/Interface.hs. I am running with stack exec DyanmicLoad-exe.
GHC version is 8.0.1
Full output:
$ stack exec DyanmicLoad-exe
Loaded Interface
Loaded Plugin Module!
DyanmicLoad-exe: /home/ubuntu/DynamicLoadTest/Plugin.o: unknown symbol `ghczmprim_GHCziCString_unpackCStringzh_closure'
DyanmicLoad-exe: user error (Unable to resolve functions!)
Edit 1:
Error with the -dynamic flag on build.
$ stack exec DyanmicLoad-exe
Loaded Interface
Loaded Plugin Module!
DyanmicLoad-exe: /home/ubuntu/DynamicLoadTest/Plugin.o: unhandled ELF relocation(RelA) type 42
DyanmicLoad-exe: user error (Unable to resolve functions!)
Edit 2 .cabal file
name: DyanmicLoad
version: 0.1.0.0
synopsis: Initial project template from stack
description: Please see README.md
homepage: https://github.com/githubuser/DyanmicLoad#readme
license: BSD3
license-file: LICENSE
author: Author name here
maintainer: example#example.com
copyright: 2017 Author name here
category: Web
build-type: Simple
extra-source-files: README.md
cabal-version: >=1.10
library
hs-source-dirs: src
exposed-modules: Lib
, Interface
build-depends: base >= 4.7 && < 5
, dynamic-loader
, directory
default-language: Haskell2010
executable DyanmicLoad-exe
hs-source-dirs: app
main-is: Main.hs
ghc-options: -dynamic -threaded -rtsopts -with-rtsopts=-N
build-depends: base
, DyanmicLoad
default-language: Haskell2010
test-suite DyanmicLoad-test
type: exitcode-stdio-1.0
hs-source-dirs: test
main-is: Spec.hs
build-depends: base
, DyanmicLoad
ghc-options: -threaded -rtsopts -with-rtsopts=-N
default-language: Haskell2010
source-repository head
type: git
location: https://github.com/githubuser/DyanmicLoad
I need a library to encode data in cp1251 to work with an api which use it.
I found only 2 libs for this purpose. The encoding lib and text-icu lib. The first one looks better just because it can be statically linked to my program.
But I can't even compile it! I am using stack so I add encoding to build-deps in my .cabal file, and then stack solver update my stack yaml file with encoding-0.8 in extra-deps.
but after running stack build I a got an error
Data/Encoding/Preprocessor/XMLMapping.hs:11:8:
Could not find module ‘Text.XML.HaXml.Types’
Use -v to see a list of the files searched for.
Data/Encoding/Preprocessor/XMLMappingBuilder.hs:15:8:
Could not find module ‘Text.XML.HaXml.OneOfN’
Use -v to see a list of the files searched for.
Data/Encoding/Preprocessor/XMLMappingBuilder.hs:16:8:
Could not find module ‘Text.XML.HaXml.XmlContent’
Use -v to see a list of the files searched for.
I tried to use older version of HaXml and encoding but got the same error.
For example I tried to use encoding-0.6.7 with HaXml-1.22.3, after reading changelog https://hackage.haskell.org/package/encoding-0.7.0.2/changelog but got the same error.
In hackage documentation all this modules which encoding can't import exists.
How can I compile this lib? I am using stack 1.0.4, lts-5.6 and ghc-7.10.3 on linux mint x64
stack.yaml
flags: {}
extra-package-dbs: []
packages:
- '.'
extra-deps:
- encoding-0.8
- text-1.2.2.0
resolver: lts-5.6
cabal:
name: hapidry
version: 0.1.1.0
synopsis: Initial project template from stack
description: Please see README.md
homepage: -
license: GPL-2
license-file: LICENSE
author: -
maintainer: -
copyright: GPL
category: network
build-type: Simple
-- extra-source-files:
cabal-version: >=1.10
library
hs-source-dirs: src
exposed-modules: Lib
build-depends: base >= 4.7 && < 5
default-language: Haskell2010
executable hapidry-exe
hs-source-dirs: app
main-is: Main.hs
ghc-options: -threaded -rtsopts -with-rtsopts=-N
build-depends: base
, hapidry
, wreq
, ConfigFile
, aeson
, lens
, cryptohash
, binary
, mtl
, base16-bytestring
, bytestring
, containers
, text
, lens-aeson
, data-default
, optparse-applicative
, encoding
default-language: Haskell2010
test-suite hapidry-test
type: exitcode-stdio-1.0
hs-source-dirs: test
main-is: Spec.hs
build-depends: base
, hapidry
ghc-options: -threaded -rtsopts -with-rtsopts=-N
default-language: Haskell2010
source-repository head
type: git
location: -
Finally I wrote my own funtion for encoding. It looks like acceptable workaround. And functions for another one-byte encodings can be implemented in the same way.
toCP1251 :: Text -> B.ByteString
toCP1251 = B.pack . T.unpack . T.map replace where
replace l = case (Map.lookup l table) of
(Just x) -> x
(Nothing) -> l
table = Map.fromList $ zip rus cpCodes
cpCodes = map toEnum (168:184:[192 .. 255]) :: [Char]
rus = ['Ё', 'ё', 'А', 'Б', 'В', 'Г', 'Д', 'Е', 'Ж', 'З', 'И', 'Й', 'К', 'Л', 'М',
'Н', 'О', 'П', 'Р', 'С', 'Т', 'У', 'Ф', 'Х', 'Ц', 'Ч', 'Ш', 'Щ', 'Ъ', 'Ы',
'Ь', 'Э', 'Ю', 'Я', 'а', 'б', 'в', 'г', 'д', 'е', 'ж', 'з', 'и', 'й', 'к',
'л', 'м', 'н', 'о', 'п', 'р', 'с', 'т', 'у', 'ф', 'х', 'ц', 'ч', 'ш', 'щ',
'ъ', 'ы', 'ь', 'э', 'ю', 'я'] :: [Char]
My Haskell file (pretty sure this is not the problem) is basically:
import System.IO
...
-- | Every Word is a String
type Word = String
...
-- | Some documentation for Haddock to see
main :: IO ()
main = do
...
My Setup.hs:
import Distribution.Simple
main = defaultMain
My grade.cabal:
name: grade
version: 0.1.0.0
...
build-type: Simple
cabal-version: >=1.8
executable grade
main-is: grade.hs
-- other-modules:
build-depends: base ==4.6.*, split ==0.2.*
hs-source-dirs: src
When I run cabal haddock --executables I get
...
Haddock coverage:
Warning: Not found in environment: Main.main
50% ( 1 / 2) in 'Main'
Warning: Main: could not find link destinations for:
Main.main
Documentation created: dist/doc/html/grade/grade/index.html
and the HTML contains main but no documentation for it. It does not even contain functions I defined other than main. Why is that?
You need to add a module declaration to generate documents for it.
module Main (main, Word) where
I've implemented a custom preprocessor which creates *.hs files form *.tpl files. It is specified in Setup.hs by using a Build-Type: Custom. Everything works fine, but I can't create tar.gz package from it (using cabal sdist).
Cabal complains, that it can not find the exposed modules which are generated by the preprocessor. The error message is
cabal: Error: Could not find module with any
suffix: ["gc","chs","hsc","x","y","ly","cpphs","hs","lhs"]
How can I make Cabal aware of the fact that the module is not missing, or maybe add tpl to the known file extensions, or something?
This is a known issue with cabal sdist. Use ./dist/setup/setup sdist instead.
Here's an example:
$ cat preprocessor-test.cabal
name: preprocessor-test
version: 0.1.0.0
build-type: Custom
cabal-version: >=1.10
extra-source-files: PreprocessorTest/*.prepro
library
exposed-modules: PreprocessorTest.PreprocessorTest
build-depends: base ==4.5.*
-- hs-source-dirs:
default-language: Haskell2010
$ cat Setup.hs
#!/usr/bin/env runhaskell
import Distribution.Simple
import Distribution.Simple.PreProcess
import Distribution.Simple.Utils
import Distribution.PackageDescription
import Distribution.Simple.LocalBuildInfo
import System.Cmd (rawSystem)
import System.FilePath ((</>))
main = let hooks = simpleUserHooks
dummy = ("prepro", dummyPreprocessor)
in defaultMainWithHooks hooks
{ hookedPreProcessors = dummy:knownSuffixHandlers }
dummyPreprocessor :: BuildInfo -> LocalBuildInfo -> PreProcessor
dummyPreprocessor build local = PreProcessor {
platformIndependent = True,
runPreProcessor =
mkSimplePreProcessor $ \inFile outFile verbosity -> do
notice verbosity (inFile ++ " is being preprocessed to " ++ outFile)
rawSystem "cp" [inFile, outFile]
return ()
}
$ cat PreprocessorTest/PreprocessorTest.prepro
module PreprocessorTest.PreprocessorTest
where
preprocessorTest :: Int
preprocessorTest = 1
$ cabal configure
Resolving dependencies...
[1 of 1] Compiling Main ( Setup.hs, dist/setup/Main.o )
Linking ./dist/setup/setup ...
Configuring preprocessor-test-0.1.0.0...
$ cabal build
Building preprocessor-test-0.1.0.0...
Preprocessing library preprocessor-test-0.1.0.0...
PreprocessorTest/PreprocessorTest.prepro is being preprocessed to
dist/build/PreprocessorTest/PreprocessorTest.hs
[1 of 1] Compiling PreprocessorTest.PreprocessorTest ( dist/build/PreprocessorTest/PreprocessorTest.hs, dist/build/PreprocessorTest/PreprocessorTest.o )
Registering preprocessor-test-0.1.0.0...
$ ./dist/setup/setup sdist
Distribution quality errors:
No 'synopsis' or 'description' field.
The 'license' field is missing or specified as AllRightsReserved.
Distribution quality warnings:
No 'category' field.
No 'maintainer' field.
Note: the public hackage server would reject this package.
Building source dist for preprocessor-test-0.1.0.0...
Preprocessing library preprocessor-test-0.1.0.0...
PreprocessorTest/PreprocessorTest.prepro is being preprocessed to
dist/src/sdist.-6767/preprocessor-test-0.1.0.0/dist/build/PreprocessorTest/PreprocessorTest.hs
Source tarball created: dist/preprocessor-test-0.1.0.0.tar.gz
$ tar tzf dist/preprocessor-test-0.1.0.0.tar.gz
preprocessor-test-0.1.0.0/
preprocessor-test-0.1.0.0/dist/
preprocessor-test-0.1.0.0/dist/build/
preprocessor-test-0.1.0.0/dist/build/PreprocessorTest/
preprocessor-test-0.1.0.0/dist/build/PreprocessorTest/PreprocessorTest.hs
preprocessor-test-0.1.0.0/Setup.hs
preprocessor-test-0.1.0.0/PreprocessorTest/
preprocessor-test-0.1.0.0/PreprocessorTest/PreprocessorTest.prepro
preprocessor-test-0.1.0.0/preprocessor-test.cabal
I'm trying to get cabal test to run my HUnit test, without much luck. The problem is that it can't find one of my test modules — how do I fix this?
cabal configure --enable-tests && cabal build && cabal test fails with
tests/HUnit/Test.hs:4:18:
Could not find module `AmazonTest'
/tests/HUnit
AmazonTest.hs
module AmazonTest where
import Test.HUnit
import Lib.Amazon
tests = TestList [ "test sayHello" ~: "Hell!" ~=? sayHello ]
Test.hs
module Main where
import Test.HUnit
import qualified AmazonTest as Amazon
main = runTestTT Amazon.tests
\Lib\Amazon.hs
module Lib.Amazon where
sayHello :: String
sayHello = "Hello!"
test part of my .cabal file
test-suite test
type: exitcode-stdio-1.0
main-is: tests/HUnit/Test.hs
hs-source-dirs: .
ghc-options: -Wall
build-depends: base
, myapp
, yesod-test >= 0.3 && < 0.4
, yesod-default
, yesod-core
, persistent
, persistent-postgresql
, resourcet
, monad-logger
, HUnit
, text
Add tests/HUnit to hs-source-dirs. hs-source-dirs are not searched recursively.