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C.includes does not track changes #152
Description
I am not sure if this is a cabal only issue or if it is an issue with inline-c too, but like with test.h under inline-c-cpp/test, I have a local header file that I include in my hs file, however when I make changes to it, there is no recompilation.
There seems to be an open issue for "cabal new-build does not track files added via TH’s addDependentFile", but in it there is also a comment that says that even if the issue is closed, that wouldn't fix inline-c's use case.
What is the best solution at the moment to deal with this issue? Is there a manual way that users of inline-c can tell cabal to watch specific files for changes?
Activity
junjihashimoto commentedon Jan 5, 2024
Hi @MathiasSven ,
I tried it with ghc-9.6.3 and caba-3.10.2.0.
At first, compile inline-c-cpp, next add comments to test.h, then ghc recompiles c++ sources.
Without adding comments, ghc does not recompile them.
MathiasSven commentedon Jan 7, 2024
@junjihashimoto I have made a minimal rep repo with nix at https://github.com/MathiasSven/inline-c-152-rep, perhaps I am missing some configuration, but from looking at the
inline-c-cpp/inline-c-cpp.cabalthe only thing that mentions the header file isextra-source-fileswhich I have added to my cabal file.Steps I took:
junjihashimoto commentedon Jan 7, 2024
@MathiasSven Thank you for creating the example.
I also tried it.
https://github.com/proxy/gist.github.com/junjihashimoto/827d51d5a9de639280a7e7bb2ea6ce7a
Cabal detects updating src/test.hpp, and it reruns ghc, but the binary is not updated.
https://github.com/proxy/gist.github.com/junjihashimoto/827d51d5a9de639280a7e7bb2ea6ce7a#file-gistfile1-txt-L25
So it seems that the issue is ghc not cabal.
junjihashimoto commentedon Jan 7, 2024
When you pass the
-fforce-recompoption to ghc, it seems to work as expected.Recompilation will not be executed if cabal determines that there is no update.
MathiasSven commentedon Jan 7, 2024
@junjihashimoto That would make so whenever there are any changes in an included file, all modules would be recompiled. Couldn't
inline-caddLanguage.Haskell.TH.Syntax.addDependentFilelogic to itsC.include? I have tested usingaddDependentFileby adding this to myMain.hsand it seems to work:I have added a branch to the example repo which uses
filepathanddirectorypackages in order to turnaddDependentFileinto a relative import (likeC.include) and it seems to behave exactly like I would expect. As in:extra-source-files: src/*.hppin cabal file.src/test.hpptriggers a recompile ofsrc/Main.hsbut not ofsrc/Large.hssrc/dummy_file.hpptriggers no recompilation.MathiasSven commentedon Jan 8, 2024
For my use case, it seems to work just fine to simply add
addDependentFiletoinclude:{-# LANGUAGE PackageImports #-} module Language.C.Inline.Cpp ( module Upstream , include ) where import "inline-c-cpp" Language.C.Inline.Cpp as Upstream hiding (include) import Language.Haskell.TH.Syntax (addDependentFile) import Language.Haskell.TH (DecsQ, runIO, location, loc_filename) import System.FilePath ((</>), takeDirectory) import System.Directory (getCurrentDirectory) import Control.Monad (void) include :: String -> DecsQ include s | null s = fail "inline-c: empty string (include)" | head s == '<' = verbatim $ "#include " ++ s | otherwise = do void $ addDependentFileRelative s verbatim $ "#include \"" ++ s ++ "\"" addDependentFileRelative :: FilePath -> DecsQ addDependentFileRelative relativeFile = do currentFilename <- loc_filename <$> location pwd <- runIO getCurrentDirectory let invocationRelativePath = takeDirectory (pwd </> currentFilename) </> relativeFile addDependentFile invocationRelativePath return []branch for reference
junjihashimoto commentedon Jan 14, 2024
@MathiasSven Thank you for finding the solution!
The PR is welcome.
MathiasSven commentedon Jan 14, 2024
I will make a draft PR, although this works for my use case specifically, I don't know if it would be appropriate for every use case.