Move BreakInfo into own module

while working on GHCi stuff, e.g. `GHC.Runtime.Eval.Types`, I observed a
fair amount of modules being recompiled that I didn’t expect to depend
on this, from byte code interpreters to linkers. Turns out that the
rather simple `BreakInfo` type is all these modules need from the
`GHC.Runtime.Eval.*` hierarchy, so by moving that into its own file we
make the dependency tree wider and shallower, which is probably worth
it.

6 files changed, 18 insertions, 10 deletions

diff --git a/compiler/GHC.hs b/compiler/GHC.hs
index 0e4f781a29..0488ccad11 100644
--- a/compiler/GHC.hs
+++ b/compiler/GHC.hs
@@ -321,7 +321,6 @@ import GHC.ByteCode.Types
 import qualified GHC.Linker.Loader as Loader
 import GHC.Runtime.Loader
 import GHC.Runtime.Eval
-import GHC.Runtime.Eval.Types
 import GHC.Runtime.Interpreter
 import GHC.Runtime.Context
 import GHCi.RemoteTypes
@@ -387,6 +386,7 @@ import GHC.Types.TyThing
 import GHC.Types.Name.Env
 import GHC.Types.Name.Ppr
 import GHC.Types.TypeEnv
+import GHC.Types.BreakInfo
 
 import GHC.Unit
 import GHC.Unit.Env
diff --git a/compiler/GHC/Runtime/Eval.hs b/compiler/GHC/Runtime/Eval.hs
index bceb9a4159..a4ddbbfd4a 100644
--- a/compiler/GHC/Runtime/Eval.hs
+++ b/compiler/GHC/Runtime/Eval.hs
@@ -106,6 +106,7 @@ import GHC.Types.SrcLoc
 import GHC.Types.Unique
 import GHC.Types.Unique.Supply
 import GHC.Types.TyThing
+import GHC.Types.BreakInfo
 
 import GHC.Unit
 import GHC.Unit.Module.Graph
diff --git a/compiler/GHC/Runtime/Eval/Types.hs b/compiler/GHC/Runtime/Eval/Types.hs
index c72c5c89ff..5706c037de 100644
--- a/compiler/GHC/Runtime/Eval/Types.hs
+++ b/compiler/GHC/Runtime/Eval/Types.hs
@@ -8,8 +8,7 @@
 
 module GHC.Runtime.Eval.Types (
         Resume(..), History(..), ExecResult(..),
-        SingleStep(..), isStep, ExecOptions(..),
-        BreakInfo(..)
+        SingleStep(..), isStep, ExecOptions(..)
         ) where
 
 import GHC.Prelude
@@ -19,7 +18,7 @@ import GHCi.Message (EvalExpr, ResumeContext)
 import GHC.Types.Id
 import GHC.Types.Name
 import GHC.Types.TyThing
-import GHC.Unit.Module
+import GHC.Types.BreakInfo
 import GHC.Types.Name.Reader
 import GHC.Types.SrcLoc
 import GHC.Utils.Exception
@@ -54,11 +53,6 @@ data ExecResult
        , breakInfo :: Maybe BreakInfo
        }
 
-data BreakInfo = BreakInfo
-  { breakInfo_module :: Module
-  , breakInfo_number :: Int
-  }
-
 data Resume = Resume
        { resumeStmt      :: String       -- the original statement
        , resumeContext   :: ForeignRef (ResumeContext [HValueRef])
diff --git a/compiler/GHC/Runtime/Interpreter.hs b/compiler/GHC/Runtime/Interpreter.hs
index 7dcc5fcd82..29c5592299 100644
--- a/compiler/GHC/Runtime/Interpreter.hs
+++ b/compiler/GHC/Runtime/Interpreter.hs
@@ -66,7 +66,7 @@ import GHCi.Message
 import GHCi.RemoteTypes
 import GHCi.ResolvedBCO
 import GHCi.BreakArray (BreakArray)
-import GHC.Runtime.Eval.Types(BreakInfo(..))
+import GHC.Types.BreakInfo (BreakInfo(..))
 import GHC.ByteCode.Types
 
 import GHC.Linker.Types
diff --git a/compiler/GHC/Types/BreakInfo.hs b/compiler/GHC/Types/BreakInfo.hs
new file mode 100644
index 0000000000..d08ccda0bf
--- /dev/null
+++ b/compiler/GHC/Types/BreakInfo.hs
@@ -0,0 +1,12 @@
+-- | A module for the BreakInfo type. Used by both the GHC.Runtime.Eval and
+-- GHC.Runtime.Interpreter hierarchy, so put here to have a less deep module
+-- dependency tree
+module GHC.Types.BreakInfo (BreakInfo(..)) where
+
+import GHC.Prelude
+import GHC.Unit.Module
+
+data BreakInfo = BreakInfo
+  { breakInfo_module :: Module
+  , breakInfo_number :: Int
+  }
diff --git a/compiler/ghc.cabal.in b/compiler/ghc.cabal.in
index 25833017d1..668642af80 100644
--- a/compiler/ghc.cabal.in
+++ b/compiler/ghc.cabal.in
@@ -679,6 +679,7 @@ Library
         GHC.Types.Annotations
         GHC.Types.Avail
         GHC.Types.Basic
+        GHC.Types.BreakInfo
         GHC.Types.CompleteMatch
         GHC.Types.CostCentre
         GHC.Types.CostCentre.State