Merge pull request #7347 from fgaz/download-only

--only-download flag

Author: emilypi

cabal-install/src/Distribution/Client/Config.hs

@@ -294,6 +294,7 @@ instance Semigroup SavedConfig where
         installDocumentation         = combine installDocumentation,
         installHaddockIndex          = combine installHaddockIndex,
         installDryRun                = combine installDryRun,
+        installOnlyDownload          = combine installOnlyDownload,
         installDest                  = combine installDest,
         installMaxBackjumps          = combine installMaxBackjumps,
         installReorderGoals          = combine installReorderGoals,

cabal-install/src/Distribution/Client/ProjectBuilding.hs

@@ -652,8 +652,14 @@ rebuildTarget verbosity
               registerLock cacheLock
               sharedPackageConfig
               plan rpkg@(ReadyPackage pkg)
-              pkgBuildStatus =
-
+              pkgBuildStatus
+    | buildSettingOnlyDownload buildSettings = do
+        case pkgBuildStatus of
+          BuildStatusDownload ->
+            void $ waitAsyncPackageDownload verbosity downloadMap pkg
+          _ -> return ()
+        return $ BuildResult DocsNotTried TestsNotTried Nothing
+    | otherwise =
     -- We rely on the 'BuildStatus' to decide which phase to start from:
     case pkgBuildStatus of
       BuildStatusDownload              -> downloadPhase

cabal-install/src/Distribution/Client/ProjectConfig.hs

@@ -303,6 +303,7 @@ resolveBuildTimeSettings verbosity
   where
     buildSettingDryRun        = fromFlag    projectConfigDryRun
     buildSettingOnlyDeps      = fromFlag    projectConfigOnlyDeps
+    buildSettingOnlyDownload  = fromFlag    projectConfigOnlyDownload
     buildSettingSummaryFile   = fromNubList projectConfigSummaryFile
     --buildSettingLogFile       -- defined below, more complicated
     --buildSettingLogVerbosity  -- defined below, more complicated
@@ -328,6 +329,7 @@ resolveBuildTimeSettings verbosity
     defaults = mempty {
       projectConfigDryRun                = toFlag False,
       projectConfigOnlyDeps              = toFlag False,
+      projectConfigOnlyDownload          = toFlag False,
       projectConfigBuildReports          = toFlag NoReports,
       projectConfigReportPlanningFailure = toFlag False,
       projectConfigKeepGoing             = toFlag False,

cabal-install/src/Distribution/Client/ProjectConfig/Legacy.hs

@@ -509,6 +509,7 @@ convertLegacyBuildOnlyFlags globalFlags configFlags
 
     InstallFlags {
       installDryRun             = projectConfigDryRun,
+      installOnlyDownload       = projectConfigOnlyDownload,
       installOnly               = _,
       installOnlyDeps           = projectConfigOnlyDeps,
       installRootCmd            = _,
@@ -612,6 +613,7 @@ convertToLegacySharedConfig
       installHaddockIndex      = projectConfigHaddockIndex,
       installDest              = Flag NoCopyDest,
       installDryRun            = projectConfigDryRun,
+      installOnlyDownload      = projectConfigOnlyDownload,
       installReinstall         = mempty, --projectConfigReinstall,
       installAvoidReinstalls   = mempty, --projectConfigAvoidReinstalls,
       installOverrideReinstall = mempty, --projectConfigOverrideReinstall,

cabal-install/src/Distribution/Client/ProjectConfig/Types.hs

@@ -136,6 +136,7 @@ data ProjectConfigBuildOnly
        projectConfigVerbosity             :: Flag Verbosity,
        projectConfigDryRun                :: Flag Bool,
        projectConfigOnlyDeps              :: Flag Bool,
+       projectConfigOnlyDownload          :: Flag Bool,
        projectConfigSummaryFile           :: NubList PathTemplate,
        projectConfigLogFile               :: Flag PathTemplate,
        projectConfigBuildReports          :: Flag ReportLevel,
@@ -436,6 +437,7 @@ data BuildTimeSettings
    = BuildTimeSettings {
        buildSettingDryRun                :: Bool,
        buildSettingOnlyDeps              :: Bool,
+       buildSettingOnlyDownload          :: Bool,
        buildSettingSummaryFile           :: [PathTemplate],
        buildSettingLogFile               :: Maybe (Compiler  -> Platform
                                                 -> PackageId -> UnitId

cabal-install/src/Distribution/Client/Setup.hs

@@ -1623,6 +1623,7 @@ data InstallFlags = InstallFlags {
     installHaddockIndex     :: Flag PathTemplate,
     installDest             :: Flag Cabal.CopyDest,
     installDryRun           :: Flag Bool,
+    installOnlyDownload     :: Flag Bool,
     installMaxBackjumps     :: Flag Int,
     installReorderGoals     :: Flag ReorderGoals,
     installCountConflicts   :: Flag CountConflicts,
@@ -1665,6 +1666,7 @@ defaultInstallFlags = InstallFlags {
     installHaddockIndex    = Flag docIndexFile,
     installDest            = Flag Cabal.NoCopyDest,
     installDryRun          = Flag False,
+    installOnlyDownload    = Flag False,
     installMaxBackjumps    = Flag defaultMaxBackjumps,
     installReorderGoals    = Flag (ReorderGoals False),
     installCountConflicts  = Flag (CountConflicts True),
@@ -1878,6 +1880,11 @@ installOptions showOrParseArgs =
           installDryRun (\v flags -> flags { installDryRun = v })
           trueArg
 
+      , option [] ["only-download"]
+          "Do not build anything, only fetch the packages."
+          installOnlyDownload (\v flags -> flags { installOnlyDownload = v })
+          trueArg
+
       , option "" ["target-package-db"]
          "package database to install into. Required when using ${pkgroot} prefix."
          installDest (\v flags -> flags { installDest = v })

cabal-install/tests/UnitTests/Distribution/Client/ProjectConfig.hs

@@ -201,10 +201,11 @@ prop_roundtrip_printparse_buildonly config =
 hackProjectConfigBuildOnly :: ProjectConfigBuildOnly -> ProjectConfigBuildOnly
 hackProjectConfigBuildOnly config =
     config {
-      -- These two fields are only command line transitory things, not
+      -- These fields are only command line transitory things, not
       -- something to be recorded persistently in a config file
-      projectConfigOnlyDeps = mempty,
-      projectConfigDryRun   = mempty
+      projectConfigOnlyDeps     = mempty,
+      projectConfigOnlyDownload = mempty,
+      projectConfigDryRun       = mempty
     }
 
 prop_roundtrip_printparse_shared :: ProjectConfigShared -> Property
@@ -377,6 +378,7 @@ instance Arbitrary ProjectConfigBuildOnly where
         <$> arbitrary
         <*> arbitrary
         <*> arbitrary
+        <*> arbitrary
         <*> (toNubList <$> shortListOf 2 arbitrary)
         <*> arbitrary
         <*> arbitrary
@@ -398,6 +400,7 @@ instance Arbitrary ProjectConfigBuildOnly where
     shrink ProjectConfigBuildOnly { projectConfigVerbosity = x00
                                   , projectConfigDryRun = x01
                                   , projectConfigOnlyDeps = x02
+                                  , projectConfigOnlyDownload = x18
                                   , projectConfigSummaryFile = x03
                                   , projectConfigLogFile = x04
                                   , projectConfigBuildReports = x05
@@ -416,6 +419,7 @@ instance Arbitrary ProjectConfigBuildOnly where
       [ ProjectConfigBuildOnly { projectConfigVerbosity = x00'
                                , projectConfigDryRun = x01'
                                , projectConfigOnlyDeps = x02'
+                               , projectConfigOnlyDownload = x18'
                                , projectConfigSummaryFile = x03'
                                , projectConfigLogFile = x04'
                                , projectConfigBuildReports = x05'
@@ -434,12 +438,12 @@ instance Arbitrary ProjectConfigBuildOnly where
       | ((x00', x01', x02', x03', x04'),
          (x05', x06', x07', x08', x09'),
          (x10', x11', x12',       x14'),
-         (            x17'            ))
+         (            x17', x18'      ))
           <- shrink
                ((x00, x01, x02, x03, x04),
                 (x05, x06, x07, x08, preShrink_NumJobs x09),
                 (x10, x11, x12,      x14),
-                (          x17          ))
+                (          x17, x18     ))
       ]
       where
         preShrink_NumJobs  = fmap (fmap Positive)

changelog.d/only-download

@@ -0,0 +1,4 @@
+synopsis: Add a --only-download flag
+packages: cabal-install
+prs: #7347
+issues: #7323

doc/cabal-project.rst

@@ -269,6 +269,31 @@ package, and thus apply globally:
 
     Specifies the name of the directory of the global package store.
 
+Phase control
+-------------
+
+The following settings apply to commands that result in build actions
+(``build``, ``run``, ``repl``, ``test``...), and control which phases of the
+build are executed.
+
+.. option:: --dry-run
+
+    Do not download, build, or install anything, only print what would happen.
+
+.. option:: --only-configure
+
+    Instead of performing a full build just run the configure step.
+    Only accepted by the ``build`` command.
+
+.. option:: --only-download
+
+    Do not build anything, only fetch the packages.
+
+.. option:: --only-dependencies
+
+    Install only the dependencies necessary to build the given packages.
+    Not accepted by the ``repl`` command.
+
 Solver configuration options
 ----------------------------