Stub the implementation for all phases

lib/Language/Elna/Object/Elf.hs

@@ -33,6 +33,7 @@ module Language.Elna.Object.Elf
     , elfHeaderSize
     , elfIdentification
     , elfObject
+    , elfSectionsSize
     , rInfo
     , stInfo
     ) where
@@ -469,11 +470,23 @@ instance Exception ElfEncodingError
 fromIntegralEnum :: (Enum a, Num b) => a -> b
 fromIntegralEnum = fromIntegral . fromEnum
 
+-- * Object file generation.
+
+-- | ELF header size.
 elfHeaderSize :: Elf32_Off
 elfHeaderSize = 52
 
+-- | Calculates the size of all sections based on the 'sh_size' in the given
+-- headers and adds 'elfHeaderSize' to it.
+elfSectionsSize :: Vector Elf32_Shdr -> Elf32_Off
+elfSectionsSize = (elfHeaderSize +)
+    . Vector.foldr ((+) . sh_size) 0
+
 -- Writes an ELF object with the given header to the provided file path.
 -- The callback writes the sections and returns headers for those sections.
+--
+-- It updates some of the header header according to the given headers and
+-- expects .shstrtab be the last header in the list.
 elfObject :: FilePath -> Elf32_Ehdr -> (Handle -> IO (Vector Elf32_Shdr)) -> IO ()
 elfObject outFile header putContents = withFile outFile WriteMode withObjectFile
   where
@@ -484,7 +497,9 @@ elfObject outFile header putContents = withFile outFile WriteMode withObjectFile
     afterContents objectHandle headers =
         let headerEncodingResult = elf32Ehdr
                 $ header
-                    { e_shoff = elfHeaderSize + Vector.foldr ((+) . sh_size) 0 headers
+                    { e_shoff = elfSectionsSize headers
+                    , e_shnum = fromIntegral $ Vector.length headers
+                    , e_shstrndx = fromIntegral (Vector.length headers) - 1
                     }
          in traverse_ (ByteString.Builder.hPutBuilder objectHandle . elf32Shdr LSB) headers
             >> either throwIO (putHeaders objectHandle) headerEncodingResult