From 187904550f883ca9fed2759e5ad68fa7a546dda6 Mon Sep 17 00:00:00 2001
From: Simon Hengel <sol@typeful.net>
Date: Mon, 26 Dec 2022 18:48:25 +0700
Subject: [PATCH] Use `ghc` instead of `ghc-lib-parser` when possible

This significantly reduces the build time with recent version of GHC.
---
 app/Main.hs                   |  9 ++++++++-
 ormolu.cabal                  | 30 ++++++++++++++++++++++++++----
 tests/Ormolu/CabalInfoSpec.hs |  4 ++--
 3 files changed, 36 insertions(+), 7 deletions(-)

diff --git a/app/Main.hs b/app/Main.hs
index 79311c226..c5a8441b4 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -230,7 +230,7 @@ optsParserInfo =
               $gitBranch,
               $gitHash
             ],
-          "using ghc-lib-parser " ++ VERSION_ghc_lib_parser
+          ghcApiVersion
         ]
     exts :: Parser (a -> a)
     exts =
@@ -240,6 +240,13 @@ optsParserInfo =
         ]
     displayExts = unlines $ sort (showOutputable <$> manualExts)
 
+ghcApiVersion :: String
+#ifdef VERSION_ghc_lib_parser
+ghcApiVersion = "using ghc-lib-parser " ++ VERSION_ghc_lib_parser
+#else
+ghcApiVersion = "using ghc " ++ VERSION_ghc
+#endif
+
 optsParser :: Parser Opts
 optsParser =
   Opts
diff --git a/ormolu.cabal b/ormolu.cabal
index 867822b5c..50aa0ff9b 100644
--- a/ormolu.cabal
+++ b/ormolu.cabal
@@ -105,7 +105,6 @@ library
         dlist >=0.8 && <2.0,
         exceptions >=0.6 && <0.11,
         filepath >=1.2 && <1.5,
-        ghc-lib-parser >=9.4 && <9.5,
         megaparsec >=9.0,
         mtl >=2.0 && <3.0,
         syb >=0.7 && <0.8,
@@ -113,7 +112,16 @@ library
         text >=0.2 && <3.0,
         th-lift-instances >=0.1 && <0.2
 
-    mixins:           ghc-lib-parser hiding (Language.Haskell.TH.Syntax)
+    if impl(ghc >=9.4 && <9.5)
+        build-depends:
+            ghc,
+            ghc-boot-th
+
+        mixins:        ghc hiding (Language.Haskell.TH.Syntax)
+
+    else
+        build-depends: ghc-lib-parser >=9.4 && <9.5
+        mixins:        ghc-lib-parser hiding (Language.Haskell.TH.Syntax)
 
     if (flag(fixity-th) && impl(ghc <9.4))
         cpp-options: -DFIXITY_TH
@@ -140,12 +148,19 @@ executable ormolu
         base >=4.12 && <5.0,
         containers >=0.5 && <0.7,
         filepath >=1.2 && <1.5,
-        ghc-lib-parser >=9.4 && <9.5,
         gitrev >=1.3 && <1.4,
         optparse-applicative >=0.14 && <0.18,
         ormolu,
         text >=0.2 && <3.0
 
+    if impl(ghc >=9.4 && <9.5)
+        build-depends:
+            ghc,
+            ghc-boot-th
+
+    else
+        build-depends: ghc-lib-parser >=9.4 && <9.5
+
     if flag(dev)
         ghc-options:
             -Wall -Werror -Wcompat -Wincomplete-record-updates
@@ -179,7 +194,6 @@ test-suite tests
         containers >=0.5 && <0.7,
         directory ^>=1.3,
         filepath >=1.2 && <1.5,
-        ghc-lib-parser >=9.4 && <9.5,
         hspec >=2.0 && <3.0,
         hspec-megaparsec >=2.2,
         megaparsec >=9.0,
@@ -189,6 +203,14 @@ test-suite tests
         temporary ^>=1.3,
         text >=0.2 && <3.0
 
+    if impl(ghc >=9.4 && <9.5)
+        build-depends:
+            ghc,
+            ghc-boot-th
+
+    else
+        build-depends: ghc-lib-parser >=9.4 && <9.5
+
     if flag(dev)
         ghc-options: -Wall -Werror
 
diff --git a/tests/Ormolu/CabalInfoSpec.hs b/tests/Ormolu/CabalInfoSpec.hs
index 2eb7bd34e..0d04a033f 100644
--- a/tests/Ormolu/CabalInfoSpec.hs
+++ b/tests/Ormolu/CabalInfoSpec.hs
@@ -38,10 +38,10 @@ spec = do
       ciDynOpts `shouldBe` [DynOption "-XHaskell2010"]
     it "extracts correct dependencies from ormolu.cabal (src/Ormolu/Config.hs)" $ do
       CabalInfo {..} <- parseCabalInfo "ormolu.cabal" "src/Ormolu/Config.hs"
-      ciDependencies `shouldBe` Set.fromList ["Cabal-syntax", "Diff", "MemoTrie", "aeson", "ansi-terminal", "array", "base", "bytestring", "containers", "directory", "dlist", "exceptions", "file-embed", "filepath", "ghc-lib-parser", "megaparsec", "mtl", "syb", "template-haskell", "text", "th-lift-instances"]
+      ciDependencies `shouldBe` Set.fromList ["Cabal-syntax", "Diff", "MemoTrie", "aeson", "ansi-terminal", "array", "base", "bytestring", "containers", "directory", "dlist", "exceptions", "file-embed", "filepath", "ghc", "ghc-boot-th", "ghc-lib-parser", "megaparsec", "mtl", "syb", "template-haskell", "text", "th-lift-instances"]
     it "extracts correct dependencies from ormolu.cabal (tests/Ormolu/PrinterSpec.hs)" $ do
       CabalInfo {..} <- parseCabalInfo "ormolu.cabal" "tests/Ormolu/PrinterSpec.hs"
-      ciDependencies `shouldBe` Set.fromList ["QuickCheck", "base", "containers", "directory", "filepath", "ghc-lib-parser", "hspec", "hspec-megaparsec", "megaparsec", "ormolu", "path", "path-io", "temporary", "text"]
+      ciDependencies `shouldBe` Set.fromList ["QuickCheck", "base", "containers", "directory", "filepath", "ghc", "ghc-boot-th", "ghc-lib-parser", "hspec", "hspec-megaparsec", "megaparsec", "ormolu", "path", "path-io", "temporary", "text"]
 
     it "handles `hs-source-dirs: .`" $ do
       CabalInfo {..} <- parseTestCabalInfo "Foo.hs"