Put _start and main call into builtins

lib/Language/Elna/Architecture/RiscV.hs

@@ -148,7 +148,7 @@ data RelocationType
     deriving Eq
 
 data Instruction
-    = Instruction BaseOpcode Type
+    = BaseInstruction BaseOpcode Type
     | RelocatableInstruction BaseOpcode RelocationType
     | CallInstruction Text
     deriving Eq
@@ -305,11 +305,11 @@ relocationType (Higher20 rd _) = type' $ U rd 0
 
 instruction :: Instruction -> ByteString.Builder.Builder
 instruction = \case
-    (Instruction base instructionType) -> go base $ type' instructionType
+    (BaseInstruction base instructionType) -> go base $ type' instructionType
     (RelocatableInstruction base instructionType) -> go base $ relocationType instructionType
     (CallInstruction _) -> foldMap instruction
-        [ Instruction Auipc $ U RA 0
-        , Instruction Jalr $ I RA JALR RA 0
+        [ BaseInstruction Auipc $ U RA 0
+        , BaseInstruction Jalr $ I RA JALR RA 0
         ]
   where
     go base instructionType

lib/Language/Elna/CodeGenerator.hs

@@ -1,17 +1,28 @@
 module Language.Elna.CodeGenerator
-    ( generateCode
+    ( Asm(..)
+    , generateCode
     ) where
 
+import Data.Text (Text)
 import Data.Vector (Vector)
 import qualified Data.Vector as Vector
 import Language.Elna.Intermediate (Quadruple(..))
 import qualified Language.Elna.Architecture.RiscV as RiscV
 import Language.Elna.SymbolTable (SymbolTable)
 
-generateCode :: SymbolTable -> Vector Quadruple -> Vector RiscV.Instruction
+data Directive
+    = GlobalDirective
+    | FunctionDirective
+    deriving (Eq, Show)
+
+data Asm
+    = Instruction RiscV.Instruction
+    | JumpLabel Text [Directive]
+    deriving Eq
+
+generateCode :: SymbolTable -> Vector Quadruple -> Vector Asm
 generateCode _ _ = Vector.fromList
-    [ RiscV.CallInstruction "printi"
-    , RiscV.Instruction RiscV.OpImm $ RiscV.I RiscV.A0 RiscV.ADDI RiscV.Zero 0
-    , RiscV.Instruction RiscV.OpImm $ RiscV.I RiscV.A7 RiscV.ADDI RiscV.Zero 93
-    , RiscV.Instruction RiscV.System $ RiscV.Type RiscV.Zero RiscV.PRIV RiscV.Zero RiscV.ECALL
+    [ JumpLabel "main" [GlobalDirective, FunctionDirective]
+    , Instruction (RiscV.CallInstruction "printi")
+    , Instruction (RiscV.BaseInstruction RiscV.Jalr $ RiscV.I RiscV.RA RiscV.JALR RiscV.Zero 0)
     ]

lib/Language/Elna/NameAnalysis.hs

@@ -25,7 +25,23 @@ data Error
     | IdentifierAlreadyDefinedError Identifier
     | UndefinedSymbolError Identifier
     | UnexpectedArrayByValue Identifier
-    deriving (Eq, Show)
+    deriving Eq
+
+instance Show Error
+  where
+    show (UndefinedTypeError identifier) =
+        concat ["Type \"", show identifier, "\" is not defined"]
+    show (UnexpectedTypeInfoError info) = show info
+        <> " expected to be a type"
+    show (IdentifierAlreadyDefinedError identifier) =
+        concat ["The identifier \"", show identifier, "\" is already defined"]
+    show (UndefinedSymbolError identifier) =
+        concat ["Symbol \"", show identifier, "\" is not defined"]
+    show (UnexpectedArrayByValue identifier) = concat
+        [ "Array \""
+        , show identifier
+        , "\" cannot be passed by value, only by reference"
+        ]
 
 newtype NameAnalysis a = NameAnalysis
     { runNameAnalysis :: Except Error a
@@ -61,7 +77,7 @@ procedureDeclaration globalTable (AST.ProcedureDeclaration identifier parameters
             $ Vector.fromList parametersInfo
     maybe (NameAnalysis $ throwE $ IdentifierAlreadyDefinedError identifier) pure
         $ SymbolTable.enter identifier procedureInfo globalTable
-        
+
 declaration :: SymbolTable -> AST.Declaration -> NameAnalysis SymbolTable
 declaration globalTable (AST.ProcedureDeclaration identifier parameters variables body) = do
     variableInfo <- mapM (variableDeclaration globalTable) variables

lib/Language/Elna/PrinterWriter.hs

@@ -44,11 +44,12 @@ import qualified Language.Elna.Architecture.RiscV as RiscV
 import qualified Data.Text.Encoding as Text.Encoding
 import Control.Monad.IO.Class (MonadIO(..))
 import Control.Monad.Trans.State (get)
+import Language.Elna.CodeGenerator (Asm(..))
 
 data UnresolvedRelocation = UnresolvedRelocation ByteString Elf32_Addr Word8
 data UnresolvedRelocations = UnresolvedRelocations (Vector UnresolvedRelocation) Elf32_Word
 
-riscv32Elf :: Vector RiscV.Instruction -> Handle -> ElfWriter Elf32_Ehdr
+riscv32Elf :: Vector Asm -> Handle -> ElfWriter Elf32_Ehdr
 riscv32Elf code objectHandle = text
     >>= uncurry symrel
     >>= strtab
@@ -197,7 +198,7 @@ riscv32Elf code objectHandle = text
         pure (symbolResult, UnresolvedRelocations relocations $ fromIntegral $ Vector.length sectionHeaders)
     symbolEntry
         :: Elf32_Half
-        -> Vector RiscV.Instruction
+        -> Vector Asm
         -> (ElfHeaderResult Elf32_Sym, Elf32_Addr, Vector UnresolvedRelocation)
         -> ElfWriter (ElfHeaderResult Elf32_Sym, Elf32_Addr, Vector UnresolvedRelocation)
     symbolEntry shndx instructions (ElfHeaderResult names entries, offset, relocations) = do
@@ -216,14 +217,14 @@ riscv32Elf code objectHandle = text
                 , st_size = 0
                 , st_shndx = 0
                 , st_other = 0
-                , st_name = fromIntegral (ByteString.length names) + 7
+                , st_name = fromIntegral (ByteString.length names) + 5
                 , st_info = stInfo STB_GLOBAL STT_FUNC
                 }
         liftIO $ ByteString.hPut objectHandle $ LazyByteString.toStrict encoded
-        let newResult = ElfHeaderResult (names <> "_start\0printi\0")
+        let newResult = ElfHeaderResult (names <> "main\0printi\0")
                 $ Vector.snoc (Vector.snoc entries newEntry) printEntry
         pure (newResult, size, updatedRelocations)
-    encodeInstruction (instructions, offset, relocations) instruction =
+    encodeInstruction (instructions, offset, relocations) (Instruction instruction) =
         let unresolvedRelocation = case instruction of
                 RiscV.RelocatableInstruction _ instructionType
                     | RiscV.Higher20 _ symbolName <- instructionType
@@ -238,7 +239,7 @@ riscv32Elf code objectHandle = text
                 RiscV.CallInstruction symbolName
                     -> Just -- R_RISCV_CALL_PLT
                     $ UnresolvedRelocation (Text.Encoding.encodeUtf8 symbolName) offset 19
-                RiscV.Instruction _ _ -> Nothing
+                RiscV.BaseInstruction _ _ -> Nothing
             encoded = ByteString.Builder.toLazyByteString
                 $ RiscV.instruction instruction
          in
@@ -246,3 +247,4 @@ riscv32Elf code objectHandle = text
             , offset + fromIntegral (LazyByteString.length encoded)
             , maybe relocations (Vector.snoc relocations) unresolvedRelocation
             )
+    encodeInstruction accumulator (JumpLabel _ _) = accumulator

tools/builtin.s

@@ -1,6 +1,12 @@
+.global main
+.type main, @function
+
 .global printi
 .type printi, @function
 
+.global _start
+.type _start, @function
+
 .text
 printi:
     addi sp, sp, -8
@@ -27,3 +33,9 @@ printi:
     lw ra, 4(sp)
     addi sp, sp, 8
     ret
+
+_start:
+    call "main"
+    addi a0, zero, 0
+    addi a7, zero, 93
+    ecall