Lint the compiler for extraneous LANGUAGE pragmas

2 files changed, 34 insertions, 4 deletions

diff --git a/hadrian/src/Main.hs b/hadrian/src/Main.hs
index e6bf015c0a..d75bc743a7 100644
--- a/hadrian/src/Main.hs
+++ b/hadrian/src/Main.hs
@@ -1,21 +1,21 @@
 module Main (main) where
 
-import System.Directory (getCurrentDirectory)
 import Development.Shake
 import Hadrian.Expression
 import Hadrian.Utilities
 import Settings.Parser
+import System.Directory (getCurrentDirectory)
 
 import qualified Base
 import qualified CommandLine
 import qualified Environment
 import qualified Rules
 import qualified Rules.Clean
-import qualified Rules.Lint
 import qualified Rules.Documentation
+import qualified Rules.Lint
 import qualified Rules.Nofib
-import qualified Rules.SourceDist
 import qualified Rules.Selftest
+import qualified Rules.SourceDist
 import qualified Rules.Test
 import qualified UserSettings
 
diff --git a/hadrian/src/Rules/Lint.hs b/hadrian/src/Rules/Lint.hs
index 39e047a4d4..76ee4a7028 100644
--- a/hadrian/src/Rules/Lint.hs
+++ b/hadrian/src/Rules/Lint.hs
@@ -7,7 +7,9 @@ import Settings.Builders.Common
 import System.Directory (findExecutable)
 
 lintRules :: Rules ()
-lintRules = "lint:base" ~> lint base
+lintRules = do
+  "lint:base" ~> lint base
+  "lint:compiler" ~> lint compiler
 
 lint :: Action () -> Action ()
 lint lintAction = do
@@ -43,3 +45,31 @@ base = do
                 " -h " <> hlintYaml <> " libraries/base"
   putBuild $ "| " <> cmdLine
   cmd_ cmdLine
+
+compiler :: Action ()
+compiler = do
+  topDir   <- topDirectory
+  buildDir <- buildRoot
+  let stage1Lib      = topDir </> buildDir </> "stage1/lib"
+  let stage1Compiler = topDir </> buildDir </> "stage1/compiler/build"
+  let machDeps       = topDir </> "includes/MachDeps.h"
+  let hsVersions     = topDir </> "compiler/HsVersions.h"
+  let compilerDir    = topDir </> "compiler"
+  let ghcautoconf    = stage1Lib </> "ghcautoconf.h"
+  let ghcplatform    = stage1Lib </> "ghcplatform.h"
+  let pmv            = stage1Compiler </> "primop-vector-uniques.hs-incl"
+  need [ghcautoconf, ghcplatform, machDeps, hsVersions, pmv]
+  let include0  = topDir </> "includes"
+  let include1  = stage1Lib
+  let hlintYaml = topDir </> "compiler/.hlint.yaml"
+  hostArch <- (<> "_HOST_ARCH") <$> setting HostArch
+  let cmdLine = "hlint -j --cpp-define " <> hostArch <>
+                " --cpp-include=" <> include0 <>
+                " --cpp-include=" <> include1 <>
+                " --cpp-include=" <> compilerDir <>
+                " --cpp-include=" <> ghcplatform <>
+                " --cpp-include=" <> stage1Compiler <>
+                " -h " <> hlintYaml <> " compiler"
+  putBuild $ "| " <> cmdLine
+  cmd_ cmdLine
+