Add symbol entry header structure

elna.cabal

@@ -19,6 +19,7 @@ common warnings
         base ^>=4.19.1.0,
         bytestring ^>= 0.12.1,
         megaparsec ^>= 9.6,
+        vector ^>= 0.13.1,
         text ^>= 2.0
     ghc-options: -Wall
     default-extensions:
@@ -37,7 +38,6 @@ library elna-internal
         hashable ^>= 1.4.3,
         parser-combinators ^>= 1.3,
         transformers ^>= 0.6.1,
-        vector ^>= 0.13.1,
         unordered-containers ^>= 0.2.20
     hs-source-dirs: lib
 

lib/Language/Elna/Object/Elf.hs

@@ -6,6 +6,7 @@ module Language.Elna.Object.Elf
     , Elf32_Sword
     , Elf32_Ehdr(..)
     , Elf32_Shdr(..)
+    , Elf32_Sym(..)
     , ElfIdentification(..)
     , ElfMachine(..)
     , ElfVersion(..)
@@ -19,12 +20,13 @@ module Language.Elna.Object.Elf
     , elf32Sword
     , elf32Word
     , elf32Ehdr
+    , elf32Sym
     , elfIdentification
     ) where
 
 import qualified Data.ByteString.Builder as ByteString.Builder
 import Data.Int (Int32)
-import Data.Word (Word16, Word32)
+import Data.Word (Word8, Word16, Word32)
 import qualified Data.ByteString as ByteString
 
 -- * Data types.
@@ -190,6 +192,17 @@ instance Enum ElfType
     fromEnum ET_LOPROC = 0xff00
     fromEnum ET_HIPROC = 0xffff
 
+data Elf32_Sym = Elf32_Sym
+    { st_name :: Elf32_Word
+    , st_value :: Elf32_Addr
+    , st_size :: Elf32_Word
+    , st_info :: Word8
+    , st_other :: Word8
+    , st_shndx :: Elf32_Half 
+    } deriving Eq
+
+-- * Help types.
+
 data ByteOrder = LSB | MSB
     deriving Eq
 
@@ -272,3 +285,12 @@ elf32Shdr byteOrder Elf32_Shdr{..}
     <> elf32Word byteOrder sh_info
     <> elf32Word byteOrder sh_addralign
     <> elf32Word byteOrder sh_entsize
+
+elf32Sym :: ByteOrder -> Elf32_Sym -> ByteString.Builder.Builder
+elf32Sym byteOrder Elf32_Sym{..}
+    = elf32Word byteOrder st_name
+    <> elf32Addr byteOrder st_value
+    <> elf32Word byteOrder st_size
+    <> ByteString.Builder.word8 st_info
+    <> ByteString.Builder.word8 st_other
+    <> elf32Half byteOrder st_shndx

src/Main.hs

@@ -2,9 +2,11 @@ module Main
     ( main
     ) where
 
-import Language.Elna.Object.Elf ()
+import Language.Elna.Object.Elf (Elf32_Sym(..))
 import Data.ByteString (ByteString)
 import qualified Data.ByteString as ByteString
+import Data.Vector (Vector)
+import qualified Data.Vector as Vector
 import Data.Bits (Bits(..))
 
 data Chunk
@@ -20,7 +22,7 @@ instance Show Chunk
     show (SymbolDefinitionChunk label chunk)
         = "SymbolDefinitionChunk "
         <> show label
-        <> "(Size: "
+        <> " (Size: "
         <> show (ByteString.length chunk)
         <> ")"
 
@@ -39,6 +41,22 @@ splitContents accumulator remaining
                  in splitContents (SymbolDefinitionChunk label chunk : accumulator) remaining'
             _ -> ExternSymbolChunk label : accumulator
 
+go
+    :: Chunk
+    -> (Vector Elf32_Sym, Vector ByteString)
+    -> (Vector Elf32_Sym, Vector ByteString)
+go (ExternSymbolChunk symbolName) (symbolEntries, stringTable) =
+    let symbolEntry = Elf32_Sym
+            { st_name = fromIntegral $ Vector.foldr ((+) . ByteString.length) 0 stringTable
+            , st_value = 0
+            , st_size = 0
+            , st_info = shiftL 1 4 -- STB_GLOBAL and STT_NOTYPE
+            , st_other = 0
+            , st_shndx = 0 -- SHN_UNDEF
+            }
+     in (Vector.snoc symbolEntries symbolEntry, Vector.snoc stringTable symbolName)
+go (SymbolDefinitionChunk _ _) _acc = undefined
+
 main :: IO ()
 main = do
     contents <- ByteString.getContents