'cabal repl': when there's no .cabal file, just start ghci.

Fixes haskell#1554.
gentoo-haskell · Dec 19, 2013 · b209238 · b209238
1 parent 2bbe274
commit b209238
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Showing 3 changed files with 67 additions and 29 deletions.
diff --git a/Cabal/Distribution/Simple/Build.hs b/Cabal/Distribution/Simple/Build.hs
@@ -47,6 +47,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. -}
 
 module Distribution.Simple.Build (
     build, repl,
+    startInterpreter,
 
     initialBuildSteps,
     writeAutogenFiles,
@@ -67,7 +68,8 @@ import Distribution.Package
          ( Package(..), PackageName(..), PackageIdentifier(..)
          , Dependency(..), thisPackageVersion )
 import Distribution.Simple.Compiler
-         ( CompilerFlavor(..), compilerFlavor, PackageDB(..) )
+         ( Compiler, CompilerFlavor(..), compilerFlavor
+         , PackageDB(..), PackageDBStack )
 import Distribution.PackageDescription
          ( PackageDescription(..), BuildInfo(..), Library(..), Executable(..)
          , TestSuite(..), TestSuiteInterface(..), Benchmark(..)
@@ -202,6 +204,13 @@ repl pkg_descr lbi flags suffixes args = do
    in replComponent verbosity pkg_descr lbi' suffixes comp clbi distPref
 
 
+-- | Start an interpreter without loading any package files.
+startInterpreter :: Verbosity -> ProgramDb -> Compiler -> PackageDBStack -> IO ()
+startInterpreter verbosity programDb comp packageDBs =
+  case compilerFlavor comp of
+    GHC -> GHC.startInterpreter verbosity programDb comp packageDBs
+    _   -> die "A REPL is not supported with this compiler."
+
 buildComponent :: Verbosity
                -> Flag (Maybe Int)
                -> PackageDescription

diff --git a/Cabal/Distribution/Simple/GHC.hs b/Cabal/Distribution/Simple/GHC.hs
@@ -65,6 +65,7 @@ module Distribution.Simple.GHC (
         configure, getInstalledPackages, getPackageDBContents,
         buildLib, buildExe,
         replLib, replExe,
+        startInterpreter,
         installLib, installExe,
         libAbiHash,
         initPackageDB,
@@ -917,6 +918,17 @@ buildOrReplLib forRepl verbosity numJobsFlag pkg_descr lbi lib clbi = do
     whenSharedLib False $
       runGhcProg ghcSharedLinkArgs
 
+-- | Start a REPL without loading any source files.
+startInterpreter :: Verbosity -> ProgramConfiguration -> Compiler
+                 -> PackageDBStack -> IO ()
+startInterpreter verbosity conf comp packageDBs = do
+  let replOpts = mempty {
+        ghcOptMode       = toFlag GhcModeInteractive,
+        ghcOptPackageDBs = packageDBs
+        }
+  checkPackageDbStack packageDBs
+  (ghcProg, _) <- requireProgram verbosity ghcProgram conf
+  runGHC verbosity ghcProg comp replOpts
 
 -- | Build an executable with GHC.
 --

diff --git a/cabal-install/Main.hs b/cabal-install/Main.hs
@@ -101,6 +101,8 @@ import Distribution.Client.Utils              (determineNumJobs
 
 import Distribution.PackageDescription
          ( Executable(..) )
+import Distribution.Simple.Build
+         ( startInterpreter )
 import Distribution.Simple.Command
          ( CommandParse(..), CommandUI(..), Command
          , commandsRun, commandAddAction, hiddenCommand )
@@ -114,7 +116,7 @@ import qualified Distribution.Simple.LocalBuildInfo as LBI
 import Distribution.Simple.Program (defaultProgramConfiguration)
 import qualified Distribution.Simple.Setup as Cabal
 import Distribution.Simple.Utils
-         ( cabalVersion, die, notice, info, topHandler )
+         ( cabalVersion, die, notice, info, topHandler, findPackageDesc )
 import Distribution.Text
          ( display )
 import Distribution.Verbosity as Verbosity
@@ -128,7 +130,7 @@ import System.Exit              (exitFailure)
 import System.FilePath          (splitExtension, takeExtension)
 import System.IO                (BufferMode(LineBuffering),
                                  hSetBuffering, stdout)
-import System.Directory         (doesFileExist)
+import System.Directory         (doesFileExist, getCurrentDirectory)
 import Data.List                (intercalate)
 import Data.Monoid              (Monoid(..))
 import Control.Monad            (when, unless)
@@ -326,32 +328,47 @@ filterBuildFlags version config buildFlags
 
 replAction :: ReplFlags -> [String] -> GlobalFlags -> IO ()
 replAction replFlags extraArgs globalFlags = do
-  let distPref    = fromFlagOrDefault (useDistPref defaultSetupScriptOptions)
-                    (replDistPref replFlags)
-      verbosity   = fromFlagOrDefault normal (replVerbosity replFlags)
-      noAddSource = case replReload replFlags of
-                      Flag True -> SkipAddSourceDepsCheck
-                      _         -> DontSkipAddSourceDepsCheck
-
-  -- Calls 'configureAction' to do the real work, so nothing special has to be
-  -- done to support sandboxes.
-  (useSandbox, _config) <- reconfigure verbosity distPref
-                           mempty [] globalFlags noAddSource NoFlag
-                           (const Nothing)
-
-  maybeWithSandboxDirOnSearchPath useSandbox $
-    let progConf     = defaultProgramConfiguration
-        setupOptions = defaultSetupScriptOptions
-          { useCabalVersion = orLaterVersion $ Version [1,18,0] []
-          , useDistPref     = distPref
-          }
-        replFlags'   = replFlags
-          { replVerbosity = toFlag verbosity
-          , replDistPref  = toFlag distPref
-          }
-    in setupWrapper verbosity setupOptions Nothing
-         (Cabal.replCommand progConf) (const replFlags') extraArgs
-
+  cwd     <- getCurrentDirectory
+  pkgDesc <- findPackageDesc cwd
+  either (const onNoPkgDesc) (const onPkgDesc) pkgDesc
+  where
+    verbosity = fromFlagOrDefault normal (replVerbosity replFlags)
+
+    -- There is a .cabal file in the current directory: start a REPL and load
+    -- the project's modules.
+    onPkgDesc = do
+      let distPref    = fromFlagOrDefault (useDistPref defaultSetupScriptOptions)
+                        (replDistPref replFlags)
+          noAddSource = case replReload replFlags of
+                          Flag True -> SkipAddSourceDepsCheck
+                          _         -> DontSkipAddSourceDepsCheck
+          progConf     = defaultProgramConfiguration
+          setupOptions = defaultSetupScriptOptions
+            { useCabalVersion = orLaterVersion $ Version [1,18,0] []
+            , useDistPref     = distPref
+            }
+          replFlags'   = replFlags
+            { replVerbosity = toFlag verbosity
+            , replDistPref  = toFlag distPref
+            }
+      -- Calls 'configureAction' to do the real work, so nothing special has to
+      -- be done to support sandboxes.
+      (useSandbox, _config) <- reconfigure verbosity distPref
+                               mempty [] globalFlags noAddSource NoFlag
+                               (const Nothing)
+
+      maybeWithSandboxDirOnSearchPath useSandbox $
+        setupWrapper verbosity setupOptions Nothing
+        (Cabal.replCommand progConf) (const replFlags') extraArgs
+
+    -- No .cabal file in the current directory: just start the REPL (possibly
+    -- using the sandbox package DB).
+    onNoPkgDesc = do
+      (_useSandbox, config) <- loadConfigOrSandboxConfig verbosity globalFlags
+                               mempty
+      let configFlags = savedConfigureFlags config
+      (comp, _platform, programDb) <- configCompilerAux' configFlags
+      startInterpreter verbosity programDb comp (configPackageDB' configFlags)
 
 -- | Re-configure the package in the current directory if needed. Deciding
 -- when to reconfigure and with which options is convoluted: