Rebase work of cfraz89 and bgamari

Add (currently nonfunctional) new-show-build-info
Fix compile error
Make new-show-build-info functional
Use silent verbosity by default on showBuildInfo commands to keep output json clean
Make show-build-info commands hidden
Implement write-autogen-files
Make new-write-autogen-files work
Make new-write-autogen-files configure if necessary
Use target selectors for new-show-build-info
Don't prune plan for new-show-build-info
Only configure in new-show-build-info and new-write-autogen-files if no persist build info file is found
Wrap multiple target output of new-show-build-info in json list

cabal-install/Distribution/Client/CmdShowBuildInfo.hs

@@ -0,0 +1,254 @@
+-- | cabal-install CLI command: build
+--
+module Distribution.Client.CmdShowBuildInfo (
+    -- * The @build@ CLI and action
+    showBuildInfoCommand,
+    showBuildInfoAction
+  ) where
+
+import Distribution.Client.ProjectOrchestration
+import Distribution.Client.CmdErrorMessages
+import Distribution.Client.CmdInstall.ClientInstallFlags
+
+import Distribution.Client.Setup
+         ( GlobalFlags, ConfigFlags(..), ConfigExFlags, InstallFlags )
+import qualified Distribution.Client.Setup as Client
+import Distribution.Simple.Setup
+         ( HaddockFlags, fromFlagOrDefault, TestFlags )
+import Distribution.Simple.Command
+         ( CommandUI(..), usageAlternatives )
+import Distribution.Verbosity
+         ( Verbosity, silent )
+import Distribution.Simple.Utils
+         ( wrapText, die')
+import Distribution.Types.UnitId (UnitId)
+
+import qualified Data.Map as Map
+import qualified Distribution.Simple.Setup as Cabal
+import Distribution.Client.SetupWrapper
+import Distribution.Simple.Program ( defaultProgramDb )
+import qualified Distribution.Client.InstallPlan as InstallPlan
+import Distribution.Client.ProjectPlanning.Types
+import Distribution.Client.ProjectPlanning (
+  setupHsConfigureFlags, setupHsConfigureArgs,
+  setupHsBuildFlags, setupHsBuildArgs, 
+  setupHsScriptOptions
+  )
+import Distribution.Client.DistDirLayout (distBuildDirectory)
+import Distribution.Client.Types ( PackageLocation(..), GenericReadyPackage(..) )
+import Distribution.Client.JobControl (newLock, Lock)
+import Distribution.Simple.Configure (tryGetPersistBuildConfig)
+import Data.List (find)
+
+showBuildInfoCommand :: CommandUI (ConfigFlags, ConfigExFlags, InstallFlags, HaddockFlags, TestFlags)
+showBuildInfoCommand = Client.installCommand {
+  commandName         = "new-show-build-info",
+  commandSynopsis     = "Show project build information",
+  commandUsage        = usageAlternatives "new-show-build-info" [ "[TARGETS] [FLAGS]" ],
+  commandDescription  = Just $ \_ -> wrapText $
+        "Build one or more targets from within the project. The available "
+     ++ "targets are the packages in the project as well as individual "
+     ++ "components within those packages, including libraries, executables, "
+     ++ "test-suites or benchmarks. Targets can be specified by name or "
+     ++ "location. If no target is specified then the default is to build "
+     ++ "the package in the current directory.\n\n"
+
+     ++ "Dependencies are built or rebuilt as necessary. Additional "
+     ++ "configuration flags can be specified on the command line and these "
+     ++ "extend the project configuration from the 'cabal.project', "
+     ++ "'cabal.project.local' and other files.",
+  commandNotes        = Just $ \pname ->
+        "Examples:\n"
+     ++ "  " ++ pname ++ " new-build\n"
+     ++ "    Build the package in the current directory or all packages in the project\n"
+     ++ "  " ++ pname ++ " new-build pkgname\n"
+     ++ "    Build the package named pkgname in the project\n"
+     ++ "  " ++ pname ++ " new-build ./pkgfoo\n"
+     ++ "    Build the package in the ./pkgfoo directory\n"
+     ++ "  " ++ pname ++ " new-build cname\n"
+     ++ "    Build the component named cname module Distribution.Client.InstallPlanin the project\n"
+     ++ "  " ++ pname ++ " new-build cname --module Distribution.Client.InstallPlanenable-profiling\n"
+     ++ "    Build the component in profilingmodule Distribution.Client.InstallPlan mode (including dependencies as needed)\n\n"
+
+     ++ cmdCommonHelpTextNewBuildBeta
+   }
+
+
+-- | The @build@ command does a lot. It brings the install plan up to date,
+-- selects that part of the plan needed by the given or implicit targets and
+-- then executes the plan.
+--
+-- For more details on how this works, see the module
+-- "Distribution.Client.ProjectOrchestration"
+--
+showBuildInfoAction :: (ConfigFlags, ConfigExFlags, InstallFlags, HaddockFlags, TestFlags)
+            -> [String] -> GlobalFlags -> IO ()
+showBuildInfoAction (configFlags, configExFlags, installFlags, haddockFlags, testFlags)
+            targetStrings globalFlags = do
+
+  baseCtx <- establishProjectBaseContext verbosity cliConfig
+  let baseCtx' = baseCtx {
+                    buildSettings = (buildSettings baseCtx) {
+                      buildSettingDryRun = True
+                    }
+                  }
+
+  targetSelectors <- either (reportTargetSelectorProblems verbosity) return
+                  =<< readTargetSelectors (localPackages baseCtx') Nothing targetStrings
+
+  buildCtx <-
+    runProjectPreBuildPhase verbosity baseCtx' $ \elaboratedPlan -> do
+      -- Interpret the targets on the command line as build targets
+      -- (as opposed to say repl or haddock targets).
+      targets <- either (reportTargetProblems verbosity) return
+                $ resolveTargets
+                    selectPackageTargets
+                    selectComponentTarget
+                    TargetProblemCommon
+                    elaboratedPlan
+                    Nothing
+                    targetSelectors
+
+      -- Don't prune the plan though, as we want a list of all configured packages
+      return (elaboratedPlan, targets)
+
+  scriptLock <- newLock
+  showTargets verbosity baseCtx' buildCtx scriptLock
+
+  where
+    -- Default to silent verbosity otherwise it will pollute our json output
+    verbosity = fromFlagOrDefault silent (configVerbosity configFlags)
+    cliConfig = commandLineFlagsToProjectConfig
+                  globalFlags configFlags configExFlags
+                  installFlags defaultClientInstallFlags
+                  haddockFlags
+                  testFlags
+
+-- Pretty nasty piecemeal out of json, but I can't see a way to retrieve output of the setupWrapper'd tasks
+showTargets :: Verbosity -> ProjectBaseContext -> ProjectBuildContext -> Lock -> IO ()
+showTargets verbosity baseCtx buildCtx lock = do
+  putStr "["
+  mapM_ showSeparated (zip [0..] targets)
+  putStrLn "]"
+    where configured = [p | InstallPlan.Configured p <- InstallPlan.toList (elaboratedPlanOriginal buildCtx)]
+          targets = fst <$> (Map.toList . targetsMap $ buildCtx)
+          doShowInfo unitId = showInfo verbosity baseCtx buildCtx lock configured unitId
+          showSeparated (idx, unitId)
+              | idx == length targets - 1 = doShowInfo unitId
+              | otherwise = doShowInfo unitId >> putStrLn "," 
+
+showInfo :: Verbosity -> ProjectBaseContext -> ProjectBuildContext -> Lock -> [ElaboratedConfiguredPackage] -> UnitId -> IO ()
+showInfo verbosity baseCtx buildCtx lock pkgs targetUnitId
+  | Nothing <- mbPkg = die' verbosity $ "No unit " ++ show targetUnitId 
+  | Just pkg <- mbPkg = do
+    let shared = elaboratedShared buildCtx
+        install = elaboratedPlanOriginal buildCtx
+        dirLayout = distDirLayout baseCtx
+        buildDir = distBuildDirectory dirLayout (elabDistDirParams shared pkg)
+        flags = setupHsBuildFlags pkg shared verbosity buildDir
+        args = setupHsBuildArgs pkg
+        srcDir = case (elabPkgSourceLocation pkg) of
+          LocalUnpackedPackage fp -> fp
+          _ -> ""
+        scriptOptions = setupHsScriptOptions 
+            (ReadyPackage pkg) 
+            install 
+            shared 
+            dirLayout
+            srcDir 
+            buildDir 
+            False 
+            lock
+        configureFlags = setupHsConfigureFlags (ReadyPackage pkg) shared verbosity buildDir
+        configureArgs = setupHsConfigureArgs pkg
+    --Configure the package if there's no existing config
+    lbi <- tryGetPersistBuildConfig buildDir
+    case lbi of
+      Left _ -> setupWrapper 
+                  verbosity 
+                  scriptOptions 
+                  (Just $ elabPkgDescription pkg) 
+                  (Cabal.configureCommand defaultProgramDb) 
+                  (const $ configureFlags)
+                  (const configureArgs)
+      Right _ -> pure ()
+    setupWrapper 
+      verbosity 
+      scriptOptions 
+      (Just $ elabPkgDescription pkg) 
+      (Cabal.showBuildInfoCommand defaultProgramDb) 
+      (const flags) 
+      (const args)
+    where mbPkg = find ((targetUnitId ==) . elabUnitId) pkgs
+
+-- | This defines what a 'TargetSelector' means for the @write-autogen-files@ command.
+-- It selects the 'AvailableTarget's that the 'TargetSelector' refers to,
+-- or otherwise classifies the problem.
+--
+-- For the @write-autogen-files@ command select all components except non-buildable and disabled
+-- tests\/benchmarks, fail if there are no such components
+--
+selectPackageTargets :: TargetSelector
+                     -> [AvailableTarget k] -> Either TargetProblem [k]
+selectPackageTargets targetSelector targets
+
+    -- If there are any buildable targets then we select those
+  | not (null targetsBuildable)
+  = Right targetsBuildable
+
+    -- If there are targets but none are buildable then we report those
+  | not (null targets)
+  = Left (TargetProblemNoneEnabled targetSelector targets')
+
+    -- If there are no targets at all then we report that
+  | otherwise
+  = Left (TargetProblemNoTargets targetSelector)
+  where
+    targets'         = forgetTargetsDetail targets
+    targetsBuildable = selectBuildableTargetsWith
+                         (buildable targetSelector)
+                         targets
+
+    -- When there's a target filter like "pkg:tests" then we do select tests,
+    -- but if it's just a target like "pkg" then we don't build tests unless
+    -- they are requested by default (i.e. by using --enable-tests)
+    buildable (TargetPackage _ _  Nothing) TargetNotRequestedByDefault = False
+    buildable (TargetAllPackages  Nothing) TargetNotRequestedByDefault = False
+    buildable _ _ = True
+
+-- | For a 'TargetComponent' 'TargetSelector', check if the component can be
+-- selected.
+--
+-- For the @build@ command we just need the basic checks on being buildable etc.
+--
+selectComponentTarget :: SubComponentTarget
+                      -> AvailableTarget k -> Either TargetProblem k
+selectComponentTarget subtarget =
+    either (Left . TargetProblemCommon) Right
+  . selectComponentTargetBasic subtarget
+
+
+-- | The various error conditions that can occur when matching a
+-- 'TargetSelector' against 'AvailableTarget's for the @build@ command.
+--
+data TargetProblem =
+     TargetProblemCommon       TargetProblemCommon
+
+     -- | The 'TargetSelector' matches targets but none are buildable
+   | TargetProblemNoneEnabled TargetSelector [AvailableTarget ()]
+
+     -- | There are no targets at all
+   | TargetProblemNoTargets   TargetSelector
+  deriving (Eq, Show)
+
+reportTargetProblems :: Verbosity -> [TargetProblem] -> IO a
+reportTargetProblems verbosity =
+    die' verbosity . unlines . map renderTargetProblem
+
+renderTargetProblem :: TargetProblem -> String
+renderTargetProblem (TargetProblemCommon problem) =
+    renderTargetProblemCommon "build" problem
+renderTargetProblem (TargetProblemNoneEnabled targetSelector targets) =
+    renderTargetProblemNoneEnabled "build" targetSelector targets
+renderTargetProblem(TargetProblemNoTargets targetSelector) =
+    renderTargetProblemNoTargets "build" targetSelector