add better error handler

lvtrun/app/Errors.hs

@@ -4,16 +4,23 @@
 -- File description:
 -- Errors
 -}
-
+ 
 module Errors
   (
-    exitWithError
+    CustomException(..),
+    handleException
   )
 where
 
-import System.Exit (exitWith, ExitCode(..))
+import Control.Exception (Exception(..), SomeException, displayException)
+
+data CustomException =
+    ParseError String |
+    WasmError String |
+    RuntimeError String
+  deriving (Show, Eq)
+
+instance Exception CustomException
 
-exitWithError :: String -> IO a
-exitWithError msg = do
-  putStrLn msg
-  exitWith $ ExitFailure 84
+handleException :: SomeException -> IO ()
+handleException e = putStrLn $ "Error: " ++ displayException e

lvtrun/app/Main.hs

@@ -5,11 +5,15 @@
 -- Main
 -}
 
+
 module Main (main) where
 
+import Control.Exception (try)
 import WasmMod.Module
+import Errors
 
 main :: IO ()
-main = do
-    wasmMod <- loadModule "./test/test.wasm"
-    print wasmMod
+main = try (loadModule "./test/test.wasm") >>= \result ->
+    case result of
+        Left err -> handleException err
+        Right wasmMod -> print wasmMod

lvtrun/app/WasmMod/Module.hs

@@ -13,12 +13,14 @@ module WasmMod.Module
 where
 
 import qualified Data.ByteString.Lazy as BS (ByteString, unpack, readFile)
+import Control.Exception (throwIO)
 import Control.Monad (when)
 import Numeric (showHex)
 
+import Errors
 import WasmMod.Header
 import WasmMod.Sections
-import Errors
+import WasmMod.Sections.Types
 
 data WasmModule = WasmModule {
   header :: ModHeader,
@@ -40,7 +42,9 @@ loadModule :: String -> IO WasmModule
 loadModule filePath = do
   bytes <- getFileContent filePath
   let modHeader = getModHeader bytes
-  when (not $ isHeaderValid modHeader) $ exitWithError "Invalid header"
+  when (not $ isHeaderValid modHeader) $ throwIO (WasmError "Invalid header")
   let modSections = getModSections bytes
-  when (not $ areSectionsValid modSections) $ exitWithError "Invalid sections"
+  when (not $ areSectionsValid modSections) $ throwIO (WasmError "Invalid sections")
+  let funcType = parseTypes $ head modSections
+  print funcType
   return $ WasmModule modHeader modSections

lvtrun/app/WasmMod/Sections.hs

@@ -15,29 +15,26 @@ module WasmMod.Sections
 where
 
 import qualified Data.ByteString.Lazy as BS (ByteString, head, drop, take, null, unpack)
-import Data.Binary.Get
-import Data.Bits
-import Data.Int (Int32, Int64)
+import Data.Word (Word8)
 import Numeric (showHex)
 import WasmMod.Leb128
-import Data.Word
-import WasmMod.Leb128
+import Data.Bits
 
 data SectionID =
   Custom
-  | Type
-  | Import
-  | Function
-  | Table
-  | Memory
-  | Global
-  | Export
-  | Start
-  | Element
-  | Code
-  | Data
-  | DataCount
-  | Invalid
+  | TypeID
+  | ImportID
+  | FunctionID
+  | TableID
+  | MemoryID
+  | GlobalID
+  | ExportID
+  | StartID
+  | ElementID
+  | CodeID
+  | DataID
+  | DataCountID
+  | InvalidID
   deriving (Show, Eq)
 
 data Section = Section {
@@ -56,19 +53,19 @@ areSectionsValid :: [Section] -> Bool
 areSectionsValid sections = True
 
 getSectionID :: Word8 -> SectionID
-getSectionID 1 = Type
-getSectionID 2 = Import
-getSectionID 3 = Function
-getSectionID 4 = Table
-getSectionID 5 = Memory
-getSectionID 6 = Global
-getSectionID 7 = Export
-getSectionID 8 = Start
-getSectionID 9 = Element
-getSectionID 10 = Code
-getSectionID 11 = Data
-getSectionID 12 = DataCount
-getSectionID _ = Invalid
+getSectionID 1 = TypeID
+getSectionID 2 = ImportID
+getSectionID 3 = FunctionID
+getSectionID 4 = TableID
+getSectionID 5 = MemoryID
+getSectionID 6 = GlobalID
+getSectionID 7 = ExportID
+getSectionID 8 = StartID
+getSectionID 9 = ElementID
+getSectionID 10 = CodeID
+getSectionID 11 = DataID
+getSectionID 12 = DataCountID
+getSectionID _ = InvalidID
 
 getSection :: BS.ByteString -> (Section, BS.ByteString)
 getSection bytes = do
@@ -90,5 +87,6 @@ getModSections' = do
             in section : getModSections'' rest
   getModSections''
 
+-- Todo: Check if sections are valid
 getModSections :: BS.ByteString -> [Section]
 getModSections bytes = getModSections' (removeHeader bytes)

lvtrun/app/WasmMod/Sections/Types.hs

@@ -0,0 +1,43 @@
+{-
+-- EPITECH PROJECT, 2023
+-- Leviator Run
+-- File description:
+-- Types
+-}
+
+module WasmMod.Sections.Types
+  (
+    parseTypes,
+    Type(..),
+    FuncType(..)
+  )
+where
+
+import WasmMod.Sections
+import WasmMod.Leb128
+import Data.Int
+import Errors
+import Control.Exception
+import qualified Data.ByteString.Lazy as Bs
+
+data Type = I32 | I64 | F32 | F64 deriving (Show, Eq)
+
+data FuncType = FuncType {
+  typeId :: Int,
+  params :: [Type],
+  results :: [Type]
+}
+
+instance Show FuncType where
+  show funcType = "(type " ++ (show $ typeId funcType) ++ " (func " ++
+    (show $ params funcType) ++ ") " ++ (show $ results funcType) ++ ")"
+
+parseFuncTypes :: Int64 -> Bs.ByteString -> [FuncType]
+parseFuncTypes 0 _ = []
+parseFuncTypes idx content = throw $ (WasmError "Not implemented")
+
+parseTypes :: Section -> [FuncType]
+parseTypes (Section TypeID _ content) = do
+  let (vecSize, rest) = extractLEB128 content
+  parseFuncTypes vecSize rest
+parseTypes _ = []

lvtrun/lvtrun.cabal

@@ -47,6 +47,7 @@ executable lvtrun-exe
       WasmMod.Leb128
       WasmMod.Module
       WasmMod.Sections
+      WasmMod.Sections.Types
       Paths_lvtrun
   autogen-modules:
       Paths_lvtrun