desugarize type definitions

src/Language/Wasm/Parser.y

@@ -2,9 +2,12 @@
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE ViewPatterns #-}
 {-# LANGUAGE DuplicateRecordFields #-}
+{-# LANGUAGE NamedFieldPuns #-}
 
 module Language.Wasm.Parser (
     parseModule,
+    parseModuleFields,
+    desugarize,
     ModuleField(..),
     DataSegment(..),
     ElemSegment(..),
@@ -44,6 +47,8 @@ import Language.Wasm.Structure (
         ValueType(..)
     )
 
+import qualified Language.Wasm.Structure as S
+
 import qualified Data.Text as T
 import qualified Data.Text.Lazy as TL
 import qualified Data.Text.Lazy.Encoding as TLEncoding
@@ -75,7 +80,8 @@ import Debug.Trace as Debug
 
 }
 
-%name parseModule modAsFields
+%name parseModule mod
+%name parseModuleFields modAsFields
 %tokentype { Lexeme }
 
 %token
@@ -263,7 +269,7 @@ import Debug.Trace as Debug
 'loop'                { Lexeme _ (TKeyword "loop") }
 'if'                  { Lexeme _ (TKeyword "if") }
 'else'                { Lexeme _ (TKeyword "else") }
-'end'                 { Lexeme _ (TKeyword "end") }
+-- unused now 'end'                 { Lexeme _ (TKeyword "end") }
 'then'                { Lexeme _ (TKeyword "then") }
 'table'               { Lexeme _ (TKeyword "table") }
 'memory'              { Lexeme _ (TKeyword "memory") }
@@ -836,6 +842,9 @@ modAsFields :: { [ModuleField] }
     : '(' 'module' list(modulefield) ')' EOF { concat $3 }
     | '(' modulefield1 list(modulefield) EOF { $2 ++ concat $3}
 
+mod :: { S.Module }
+    : modAsFields { desugarize $1 }
+
 -- utils
 
 rev_list(p)
@@ -1126,4 +1135,55 @@ happyError (Lexeme (AlexPn abs line col) tok : tokens) = error $
     "Token " ++ show tok ++ ". " ++
     "Token lookahed: " ++ show (take 3 tokens)
 
+funcTypesEq :: FuncType -> FuncType -> Bool
+funcTypesEq l r =
+    let paramTypes = map paramType . params in
+    paramTypes l == paramTypes r && results l == results r
+
+desugarize :: [ModuleField] -> S.Module
+desugarize fields =
+    let typeDefs = extractTypeDefs fields in
+    S.emptyModule {
+        S.types = map synTypeDefToStruct typeDefs
+    }
+    where
+        synTypeDefToStruct :: TypeDef -> S.FuncType
+        synTypeDefToStruct (TypeDef _ FuncType { params, results }) =
+            S.FuncType (map paramType params) results
+
+        extractTypeDefs :: [ModuleField] -> [TypeDef]
+        extractTypeDefs = reverse . foldl' extractTypeDef []
+
+        extractTypeDef :: [TypeDef] -> ModuleField -> [TypeDef]
+        extractTypeDef defs (MFType def) = def : defs
+        extractTypeDef defs (MFImport Import { desc = ImportFunc _ typeUse }) =
+            matchTypeUse defs typeUse
+        extractTypeDef defs (MFFunc Function { funcType, body }) =
+            extractTypeDefFromInstructions (matchTypeUse defs funcType) body
+        extractTypeDef defs (MFFunc Function { funcType, body }) =
+            extractTypeDefFromInstructions (matchTypeUse defs funcType) body
+        extractTypeDef defs (MFGlobal Global { initializer }) =
+            extractTypeDefFromInstructions defs initializer
+        extractTypeDef defs _ = defs
+
+        extractTypeDefFromInstructions :: [TypeDef] -> [Instruction] -> [TypeDef]
+        extractTypeDefFromInstructions = foldl' extractTypeDefFromInstruction
+
+        extractTypeDefFromInstruction :: [TypeDef] -> Instruction -> [TypeDef]
+        extractTypeDefFromInstruction defs (PlainInstr (CallIndirect typeUse)) =
+            matchTypeUse defs typeUse
+        extractTypeDefFromInstruction defs (BlockInstr { body }) =
+            extractTypeDefFromInstructions defs body
+        extractTypeDefFromInstruction defs (LoopInstr { body }) =
+            extractTypeDefFromInstructions defs body
+        extractTypeDefFromInstruction defs (IfInstr { trueBranch, falseBranch }) =
+            extractTypeDefFromInstructions defs $ trueBranch ++ falseBranch
+        extractTypeDefFromInstruction defs _ = defs
+
+        matchTypeUse :: [TypeDef] -> TypeUse -> [TypeDef]
+        matchTypeUse defs (AnonimousTypeUse funcType) =
+            if any (\(TypeDef _ ft) -> funcTypesEq ft funcType) defs
+            then defs
+            else (TypeDef Nothing funcType) : defs
+        matchTypeUse defs _ = defs
 }

src/Language/Wasm/Structure.hs

@@ -28,7 +28,8 @@ module Language.Wasm.Structure (
     Limit(..),
     GlobalType(..),
     FuncType(..),
-    ValueType(..)
+    ValueType(..),
+    emptyModule
 ) where
 
 import Numeric.Natural (Natural)
@@ -183,24 +184,21 @@ data Memory = Memory Limit deriving (Show, Eq)
 data GlobalType = Const ValueType | Mut ValueType deriving (Show, Eq)
 
 data Global = Global {
-        globalType :: GlobalType,
-        initializer :: Expression
-    }
-    deriving (Show, Eq)
+    globalType :: GlobalType,
+    initializer :: Expression
+} deriving (Show, Eq)
 
 data ElemSegment = ElemSegment {
-        tableIndex :: TableIndex,
-        offset :: [Instruction],
-        funcIndexes :: [FuncIndex]
-    }
-    deriving (Show, Eq)
+    tableIndex :: TableIndex,
+    offset :: [Instruction],
+    funcIndexes :: [FuncIndex]
+} deriving (Show, Eq)
 
 data DataSegment = DataSegment {
-        memIndex :: MemoryIndex,
-        offset :: Expression,
-        initializer :: LBS.ByteString
-    }
-    deriving (Show, Eq)
+    memIndex :: MemoryIndex,
+    offset :: Expression,
+    initializer :: LBS.ByteString
+} deriving (Show, Eq)
 
 data StartFunction = StartFunction FuncIndex deriving (Show, Eq)
 
@@ -212,10 +210,9 @@ data ExportDesc =
     deriving (Show, Eq)
 
 data Export = Export {
-        name :: TL.Text,
-        desc :: ExportDesc
-    }
-    deriving (Show, Eq)
+    name :: TL.Text,
+    desc :: ExportDesc
+} deriving (Show, Eq)
 
 data ImportDesc =
     ImportFunc TypeIndex
@@ -225,20 +222,34 @@ data ImportDesc =
     deriving (Show, Eq)
 
 data Import = Import {
-        sourceModule :: TL.Text,
-        name :: TL.Text,
-        desc :: ImportDesc
-    } deriving (Show, Eq)
+    sourceModule :: TL.Text,
+    name :: TL.Text,
+    desc :: ImportDesc
+} deriving (Show, Eq)
 
 data Module = Module {
-        types :: [FuncType],
-        functions :: [Function],
-        tables :: [Table],
-        mems :: [Memory],
-        globals :: [Global],
-        elems :: [ElemSegment],
-        datas :: [DataSegment],
-        start :: Maybe StartFunction,
-        imports :: [Import],
-        exports :: [Export]
-    } deriving (Show, Eq)
+    types :: [FuncType],
+    functions :: [Function],
+    tables :: [Table],
+    mems :: [Memory],
+    globals :: [Global],
+    elems :: [ElemSegment],
+    datas :: [DataSegment],
+    start :: Maybe StartFunction,
+    imports :: [Import],
+    exports :: [Export]
+} deriving (Show, Eq)
+
+emptyModule :: Module
+emptyModule = Module {
+    types = [],
+    functions = [],
+    tables = [],
+    mems = [],
+    globals = [],
+    elems = [],
+    datas = [],
+    start = Nothing,
+    imports = [],
+    exports = []
+}