Re: [Haskell-beginners] using Shake to compile c++

Sorry that should have been command, not command_ which is very different. On Sat, Jul 8, 2017 at 7:37 AM, David McBride wrote:

The easy option is to just use command instead of cmd. Variadic functions are always a little weird to type check.

command_ [] "pkg-config" ["glib-2.0","--cflags"]

That will *probably* solve the ambiguity in both lines, but I haven't tested.

On Sat, Jul 8, 2017 at 7:19 AM, Roger Mason wrote:

...

Hello,

I am trying the Shake build system to compile some c++. I would appreciate some advice on how to use the result of a call to pkg-config in constructing a compiler command. This is what I have currently in Build.hs:

import Development.Shake import Development.Shake.Command import Development.Shake.FilePath import Development.Shake.Util

main :: IO () main = shakeArgs shakeOptions{shakeFiles="bin"} $ do want ["bin/makelist", "bin/makejpeg" <.> exe]

phony "clean" $ do putNormal "Cleaning files in _build" removeFilesAfter "bin" ["//*"]

"bin/makelist" <.> exe %> \out -> do cs <- getDirectoryFiles "" ["src/MakeList.cxx"] let os = ["objects" c -<.> "o" | c <- cs] need os cmd "c++ -o" [out] os

"bin/makejpeg" <.> exe %> \out -> do cs <- getDirectoryFiles "" ["src/MakeJpeg.cxx"] let os = ["objects" c -<.> "o" | c <- cs] need os cmd "c++ -o" [out] os

"objects//*.o" %> \out -> do let c = dropDirectory1 $ out -<.> "cxx" let m = out -<.> "m" let i = cmd "pkg-config glib-2.0 --cflags" () <- cmd "c++ -c" [c] "-o" [out] "-MMD -MF" [m] [i] needMakefileDependencies m

This is the output from 'stack runhaskell Build.sh':

Build.hs:29:17: error: * Ambiguous type variable `t0' arising from a use of `cmd' prevents the constraint `(CmdArguments t0)' from being solved. Relevant bindings include i :: t0 (bound at Build.hs:29:13) Probable fix: use a type annotation to specify what `t0' should be. These potential instances exist: instance CmdResult r => CmdArguments (IO r) -- Defined in `Development.Shake.Command' instance CmdResult r => CmdArguments (Action r) -- Defined in `Development.Shake.Command' instance (Development.Shake.Command.Arg a, CmdArguments r) => CmdArguments (a -> r) -- Defined in `Development.Shake.Command' ...plus one other (use -fprint-potential-instances to see them all) * In the expression: cmd "pkg-config glib-2.0 --cflags" In an equation for `i': i = cmd "pkg-config glib-2.0 --cflags" In the expression: do { let c = dropDirectory1 $ out -<.> "cxx"; let m = out -<.> "m"; let i = cmd "pkg-config glib-2.0 --cflags"; () <- cmd "c++ -c" [c] "-o" [out] "-MMD -MF" [m] [i]; .... }

Build.hs:30:15: error: * Ambiguous type variable `t0' arising from a use of `cmd' prevents the constraint `(Development.Shake.Command.Arg [t0])' from being solved. Relevant bindings include i :: t0 (bound at Build.hs:29:13) Probable fix: use a type annotation to specify what `t0' should be. These potential instances exist: instance Development.Shake.Command.Arg [CmdOption] -- Defined in `Development.Shake.Command' instance Development.Shake.Command.Arg [String] -- Defined in `Development.Shake.Command' instance Development.Shake.Command.Arg String -- Defined in `Development.Shake.Command' * In a stmt of a 'do' block: () <- cmd "c++ -c" [c] "-o" [out] "-MMD -MF" [m] [i] In the expression: do { let c = dropDirectory1 $ out -<.> "cxx"; let m = out -<.> "m"; let i = cmd "pkg-config glib-2.0 --cflags"; () <- cmd "c++ -c" [c] "-o" [out] "-MMD -MF" [m] [i]; .... } In the second argument of `(%>)', namely `\ out -> do { let ...; let ...; .... }'

I would appreciate any help in getting the output of the call to pkg-config into the compiler invocation.

Thanks, Roger _______________________________________________ Beginners mailing list Beginners@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners