<div dir="ltr"><div>Hi,</div><div><br></div><div>Would it be possible to upload your full repo somewhere so people could see everything and possibly reproduce this?</div><div><br></div><div>Thanks,</div><div><br></div><div>toz</div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, May 25, 2020 at 5:03 AM <<a href="mailto:beginners-request@haskell.org">beginners-request@haskell.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Send Beginners mailing list submissions to<br>
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Today's Topics:<br>
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1. Linking C++ in Cabal (Leonhard Applis)<br>
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Message: 1<br>
Date: Sun, 24 May 2020 16:30:22 +0000<br>
From: Leonhard Applis <<a href="mailto:Leonhard.Applis@protonmail.com" target="_blank">Leonhard.Applis@protonmail.com</a>><br>
To: "<a href="mailto:beginners@haskell.org" target="_blank">beginners@haskell.org</a>" <<a href="mailto:beginners@haskell.org" target="_blank">beginners@haskell.org</a>><br>
Subject: [Haskell-beginners] Linking C++ in Cabal<br>
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Hello,<br>
<br>
I want to use a foreign C++ Function in a Haskell Library, and the Library in a Haskell Program.<br>
The C++ function is separate in a file and I have a header file. <br>
I made a minimal reproducing repository.<br>
<br>
The closes I have found is this repository which wraps the c++ in c and makes a full library, needing a makefile etc.<br>
So while I think I'd get it working like that, it looks to be quite a lot to do for my simple task.<br>
<br>
the repository structure looks as follows:<br>
<br>
Projekt<br>
<br>
- cpp-src<br>
<br>
- some.cpp<br>
- some.h<br>
<br>
- lib-src<br>
<br>
- CPPLib.hs<br>
<br>
- program-src<br>
<br>
- program.hs<br>
<br>
- project.cabal<br>
<br>
<br>
<br>
And my (currently failing) project.cabal the following:<br>
<br>
cabal-version: 3.0<br>
name: cpp_lib<br>
[...]<br>
library<br>
exposed-modules: CPPLib<br>
other-extensions: ForeignFunctionInterface<br>
build-depends: base<br>
hs-source-dirs: lib-src<br>
default-language: Haskell2010<br>
include-dirs: ./cpp-src<br>
cxx-sources: ./cpp-src/some.cpp<br>
install-includes: ./cpp-src/some.h<br>
<br>
executable CPPApp<br>
main-is: program.hs<br>
default-language: Haskell2010<br>
build-depends: HaskellForeignCPP,<br>
base<br>
hs-source-dirs: program-src<br>
<br>
The some.cpp is trivial for this case lets assume its a function multiply :: Int -> Int -> Int, and both .cpp and .h are well-formed and don't have further dependencies.<br>
<br>
The library compiles fine, but when building the executable it fails telling me<br>
<br>
collect2: error: ld returned 1 exit status<br>
`gcc' failed in phase `Linker'. (Exit code: 1)<br>
<br>
Can someone help me out?<br>
I find very little documentation on this topic.<br>
<br>
I know there is Inline-CPP which would help as well, but I just very much like the idea of having a nice separate file and interface for modularity.<br>
<br>
best<br>
Leonhard<br>
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</blockquote></div></div>