Flesh out disassembleFn a bit more

macaw-ppc/src/Data/Macaw/PPC.hs

@@ -1,4 +1,5 @@
 {-# LANGUAGE DataKinds #-}
+{-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE GADTs #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE ScopedTypeVariables #-}
@@ -164,7 +165,10 @@ ppc64_linux_info = ppc_linux_info (Proxy @PPC64.PPC)
 ppc32_linux_info :: MI.ArchitectureInfo PPC32.PPC
 ppc32_linux_info = ppc_linux_info (Proxy @PPC32.PPC)
 
-ppc_linux_info :: (ArchReg ppc ~ PPCReg ppc) => proxy ppc -> MI.ArchitectureInfo ppc
+ppc_linux_info :: (ArchReg ppc ~ PPCReg ppc,
+                  MM.MemWidth (RegAddrWidth (ArchReg ppc)))
+               => proxy ppc
+               -> MI.ArchitectureInfo ppc
 ppc_linux_info proxy =
   MI.ArchitectureInfo { MI.withArchConstraints = undefined
                       , MI.archAddrWidth = undefined

macaw-ppc/src/Data/Macaw/PPC/Disassemble.hs

@@ -1,6 +1,10 @@
+{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
 module Data.Macaw.PPC.Disassemble ( disassembleFn ) where
 
+import qualified Control.Monad.Except as ET
 import           Control.Monad.ST ( ST )
+import           Control.Monad.Trans ( lift )
 
 import           Data.Macaw.AbsDomain.AbsState as MA
 import           Data.Macaw.CFG
@@ -8,11 +12,43 @@ import           Data.Macaw.CFG.Block
 import qualified Data.Macaw.Memory as MM
 import qualified Data.Parameterized.Nonce as NC
 
-disassembleFn :: proxy ppc
+newtype DisM s a = DisM { unDisM :: ET.ExceptT DisassembleException (ST s) a }
+  deriving (Functor,
+            Applicative,
+            Monad,
+            ET.MonadError DisassembleException)
+
+data DisassembleException = DisassembleException
+  deriving (Show)
+
+liftST :: ST s a -> DisM s a
+liftST = DisM . lift
+
+tryDisassembleBlock :: MM.Memory (ArchAddrWidth ppc)
+                    -> NC.NonceGenerator (ST ids) ids
+                    -> ArchSegmentOff ppc
+                    -> ArchAddrWord ppc
+                    -> DisM s ([Block ppc ids], MM.MemWord (ArchAddrWidth ppc))
+tryDisassembleBlock = undefined
+
+-- | Disassemble a block from the given start address (which points into the
+-- 'MM.Memory').
+--
+-- Return a list of disassembled blocks as well as the total number of bytes
+-- occupied by those blocks.
+disassembleFn :: (MM.MemWidth (RegAddrWidth (ArchReg ppc)))
+              => proxy ppc
               -> MM.Memory (ArchAddrWidth ppc)
               -> NC.NonceGenerator (ST ids) ids
               -> ArchSegmentOff ppc
+              -- ^ The address to disassemble from
               -> ArchAddrWord ppc
+              -- ^ Maximum size of the block (a safeguard)
               -> MA.AbsBlockState (ArchReg ppc)
+              -- ^ Abstract state of the processor at the start of the block
               -> ST ids ([Block ppc ids], MM.MemWord (ArchAddrWidth ppc), Maybe String)
-disassembleFn = undefined
+disassembleFn _ mem nonceGen startAddr maxSize _  = do
+  mr <- ET.runExceptT (unDisM (tryDisassembleBlock mem nonceGen startAddr maxSize))
+  case mr of
+    Left exn -> return ([], 0, Just (show exn))
+    Right (blocks, bytes) -> return (blocks, bytes, Nothing)