From 637f73ec80fc8d4ea642ad409c0674d75cc68fb7 Mon Sep 17 00:00:00 2001
From: Nikolay Yakimov <root@livid.pp.ru>
Date: Wed, 24 Aug 2016 18:09:29 +0300
Subject: [PATCH] Don't build stack dependencies by default

Adds a global option `--stack-build-deps` to enable old behavior
---
 Language/Haskell/GhcMod/CabalHelper.hs     | 7 ++++---
 Language/Haskell/GhcMod/Options/Options.hs | 4 ++++
 Language/Haskell/GhcMod/Types.hs           | 2 ++
 3 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/Language/Haskell/GhcMod/CabalHelper.hs b/Language/Haskell/GhcMod/CabalHelper.hs
index 119f745..ac11a4b 100644
--- a/Language/Haskell/GhcMod/CabalHelper.hs
+++ b/Language/Haskell/GhcMod/CabalHelper.hs
@@ -208,7 +208,7 @@ withCabal action = do
                 -- "--flag PACKAGE:[-]FLAG Override flags set in stack.yaml
                 -- (applies to local packages and extra-deps)"
 
-                stackReconfigure crdl (optPrograms opts)
+                stackReconfigure (optStackBuildDeps opts) crdl (optPrograms opts)
             _ ->
                 error $ "withCabal: unsupported project type: " ++ show proj
 
@@ -234,12 +234,13 @@ withCabal action = do
             flagOpt = ["--flags", unwords $ map toFlag flgs]
 
         liftIO $ void $ readProc (T.cabalProgram progs) ("configure":progOpts) ""
-   stackReconfigure crdl progs = do
+   stackReconfigure deps crdl progs = do
      withDirectory_ (cradleRootDir crdl) $ do
        supported <- haveStackSupport
        if supported
           then do
-            spawn [T.stackProgram progs, "build", "--only-dependencies", "."]
+            when deps $
+              spawn [T.stackProgram progs, "build", "--only-dependencies", "."]
             spawn [T.stackProgram progs, "build", "--only-configure", "."]
           else
             gmLog GmWarning "" $ strDoc $ "Stack project configuration is out of date, please reconfigure manually using 'stack build' as your stack version is too old (need at least 0.1.4.0)"
diff --git a/Language/Haskell/GhcMod/Options/Options.hs b/Language/Haskell/GhcMod/Options/Options.hs
index 7d4aa3a..e648da1 100644
--- a/Language/Haskell/GhcMod/Options/Options.hs
+++ b/Language/Haskell/GhcMod/Options/Options.hs
@@ -146,6 +146,10 @@ globalArgSpec = Options
           <=> value "UTF-8"
           <=> showDefault
           <=> help "I/O encoding"
+      <*> switch
+          $$  long "stack-build-deps"
+          <=> showDefault
+          <=> help "Build dependencies if needed when using stack"
   where
     fileMappingSpec =
       getFileMapping . splitOn '=' <$> strOption
diff --git a/Language/Haskell/GhcMod/Types.hs b/Language/Haskell/GhcMod/Types.hs
index f73e01f..2be44cc 100644
--- a/Language/Haskell/GhcMod/Types.hs
+++ b/Language/Haskell/GhcMod/Types.hs
@@ -106,6 +106,7 @@ data Options = Options {
   , optGhcUserOptions :: [GHCOption]
   , optFileMappings   :: [(FilePath, Maybe FilePath)]
   , optEncoding       :: String
+  , optStackBuildDeps :: Bool
   } deriving (Show)
 
 -- | A default 'Options'.
@@ -126,6 +127,7 @@ defaultOptions = Options {
   , optGhcUserOptions = []
   , optFileMappings   = []
   , optEncoding       = "UTF-8"
+  , optStackBuildDeps = False
   }
 
 ----------------------------------------------------------------