-- |
--
-- This modules provides functions for working with both the legacy
-- "build-tools" field, and its replacement, "build-tool-depends". Prefer using
-- the functions contained to access those fields directly.
module Distribution.Simple.BuildToolDepends where

import           Prelude ()
import           Distribution.Compat.Prelude

import qualified Data.Map as Map

import           Distribution.Package
import           Distribution.PackageDescription

-- | Desugar a "build-tools" entry into proper a executable dependency if
-- possible.
--
-- An entry can be so desguared in two cases:
--
-- 1. The name in build-tools matches a locally defined executable.  The
--    executable dependency produced is on that exe in the current package.
--
-- 2. The name in build-tools matches a hard-coded set of known tools.  For now,
--    the executable dependency produced is one an executable in a package of
--    the same, but the hard-coding could just as well be per-key.
--
-- The first cases matches first.
desugarBuildTool :: PackageDescription
                 -> LegacyExeDependency
                 -> Maybe ExeDependency
desugarBuildTool :: PackageDescription -> LegacyExeDependency -> Maybe ExeDependency
desugarBuildTool PackageDescription
pkg LegacyExeDependency
led =
  if Bool
foundLocal
  then forall a. a -> Maybe a
Just forall a b. (a -> b) -> a -> b
$ PackageName -> UnqualComponentName -> VersionRange -> ExeDependency
ExeDependency (forall pkg. Package pkg => pkg -> PackageName
packageName PackageDescription
pkg) UnqualComponentName
toolName VersionRange
reqVer
  else forall k a. Ord k => k -> Map k a -> Maybe a
Map.lookup String
name Map String ExeDependency
whiteMap
  where
    LegacyExeDependency String
name VersionRange
reqVer = LegacyExeDependency
led
    toolName :: UnqualComponentName
toolName = String -> UnqualComponentName
mkUnqualComponentName String
name
    foundLocal :: Bool
foundLocal = UnqualComponentName
toolName forall (t :: * -> *) a. (Foldable t, Eq a) => a -> t a -> Bool
`elem` forall a b. (a -> b) -> [a] -> [b]
map Executable -> UnqualComponentName
exeName (PackageDescription -> [Executable]
executables PackageDescription
pkg)
    whitelist :: [String]
whitelist = [ String
"hscolour", String
"haddock", String
"happy", String
"alex", String
"hsc2hs", String
"c2hs"
                , String
"cpphs", String
"greencard", String
"hspec-discover"
                ]
    whiteMap :: Map String ExeDependency
whiteMap  = forall k a. Ord k => [(k, a)] -> Map k a
Map.fromList forall a b. (a -> b) -> a -> b
$ forall a b c. (a -> b -> c) -> b -> a -> c
flip forall a b. (a -> b) -> [a] -> [b]
map [String]
whitelist forall a b. (a -> b) -> a -> b
$ \String
n ->
      (String
n, PackageName -> UnqualComponentName -> VersionRange -> ExeDependency
ExeDependency (String -> PackageName
mkPackageName String
n) (String -> UnqualComponentName
mkUnqualComponentName String
n) VersionRange
reqVer)

-- | Get everything from "build-tool-depends", along with entries from
-- "build-tools" that we know how to desugar.
--
-- This should almost always be used instead of just accessing the
-- `buildToolDepends` field directly.
getAllToolDependencies :: PackageDescription
                       -> BuildInfo
                       -> [ExeDependency]
getAllToolDependencies :: PackageDescription -> BuildInfo -> [ExeDependency]
getAllToolDependencies PackageDescription
pkg BuildInfo
bi =
  BuildInfo -> [ExeDependency]
buildToolDepends BuildInfo
bi forall a. [a] -> [a] -> [a]
++ forall a b. (a -> Maybe b) -> [a] -> [b]
mapMaybe (PackageDescription -> LegacyExeDependency -> Maybe ExeDependency
desugarBuildTool PackageDescription
pkg) (BuildInfo -> [LegacyExeDependency]
buildTools BuildInfo
bi)

-- | Does the given executable dependency map to this current package?
--
-- This is a tiny function, but used in a number of places.
--
-- This function is only sound to call on `BuildInfo`s from the given package
-- description. This is because it just filters the package names of each
-- dependency, and does not check whether version bounds in fact exclude the
-- current package, or the referenced components in fact exist in the current
-- package.
--
-- This is OK because when a package is loaded, it is checked (in
-- `Distribution.Package.Check`) that dependencies matching internal components
-- do indeed have version bounds accepting the current package, and any
-- depended-on component in the current package actually exists. In fact this
-- check is performed by gathering the internal tool dependencies of each
-- component of the package according to this module, and ensuring those
-- properties on each so-gathered dependency.
--
-- version bounds and components of the package are unchecked. This is because
-- we sanitize exe deps so that the matching name implies these other
-- conditions.
isInternal :: PackageDescription -> ExeDependency -> Bool
isInternal :: PackageDescription -> ExeDependency -> Bool
isInternal PackageDescription
pkg (ExeDependency PackageName
n UnqualComponentName
_ VersionRange
_) = PackageName
n forall a. Eq a => a -> a -> Bool
== forall pkg. Package pkg => pkg -> PackageName
packageName PackageDescription
pkg


-- | Get internal "build-tool-depends", along with internal "build-tools"
--
-- This is a tiny function, but used in a number of places. The same
-- restrictions that apply to `isInternal` also apply to this function.
getAllInternalToolDependencies :: PackageDescription
                               -> BuildInfo
                               -> [UnqualComponentName]
getAllInternalToolDependencies :: PackageDescription -> BuildInfo -> [UnqualComponentName]
getAllInternalToolDependencies PackageDescription
pkg BuildInfo
bi =
  [ UnqualComponentName
toolname
  | dep :: ExeDependency
dep@(ExeDependency PackageName
_ UnqualComponentName
toolname VersionRange
_) <- PackageDescription -> BuildInfo -> [ExeDependency]
getAllToolDependencies PackageDescription
pkg BuildInfo
bi
  , PackageDescription -> ExeDependency -> Bool
isInternal PackageDescription
pkg ExeDependency
dep
  ]