hadrian: Introduce linting flavour transformer (+lint)

The linting flavour enables -dlint uniformly across anything build by
the stage1 compiler.

-dcmm-lint is not currently enabled because it fails on i386 (see #21563)

2 files changed, 19 insertions, 0 deletions

diff --git a/hadrian/doc/flavours.md b/hadrian/doc/flavours.md
index 5f406364a8..ad80962dbf 100644
--- a/hadrian/doc/flavours.md
+++ b/hadrian/doc/flavours.md
@@ -276,6 +276,11 @@ The supported transformers are listed below:
         <td>Collects timings while building the stage2+ compiler by adding the
         flags <code>-ddump-to-file -ddump-timings</code>.</td>
     </tr>
+    <tr>
+        <td><code>lint</code></td>
+        <td>Enable Core, STG, and C-- linting in all compilation with the stage1
+        compiler.</td>
+    </tr>
 </table>
 
 ### Static
diff --git a/hadrian/src/Flavour.hs b/hadrian/src/Flavour.hs
index 41d2f66f19..9344563ba5 100644
--- a/hadrian/src/Flavour.hs
+++ b/hadrian/src/Flavour.hs
@@ -52,6 +52,7 @@ flavourTransformers = M.fromList
     , "assertions" =: enableAssertions
     , "debug_ghc" =: debugGhc Stage1
     , "debug_stage1_ghc" =: debugGhc Stage0
+    , "lint" =: enableLinting
     ]
   where (=:) = (,)
 
@@ -130,6 +131,19 @@ enableTickyGhc =
       , arg "-ddump-stg-final"
       ]
 
+-- | Enable Core, STG, and (not C--) linting in all compilations with the stage1 compiler.
+enableLinting :: Flavour -> Flavour
+enableLinting =
+    addArgs $ stage1 ? mconcat
+      [ builder (Ghc CompileHs) ? lint
+      ]
+  where
+    lint = mconcat
+      [ arg "-dcore-lint"
+      , arg "-dstg-lint"
+      -- Should be -dlint but currently -dcmm-lint fails due to #21563
+      ]
+
 -- | Transform the input 'Flavour' so as to build with
 --   @-split-sections@ whenever appropriate. You can
 --   select which package gets built with split sections