Attach the respective metatables to loaded the config.

This simplifies calling pack() on respective tables.

4 files changed, 19 insertions, 15 deletions

diff --git a/elf/header.lua b/elf/header.lua
index 2a9ec68..6baf327 100644
--- a/elf/header.lua
+++ b/elf/header.lua
@@ -1,7 +1,5 @@
 local fmt = require("elf.fmt")
 
-local M = {}
-
 ---@alias Magic [integer, integer, integer, integer]
 
 ---@class Header
@@ -24,6 +22,7 @@ local M = {}
 ---@field shentsize integer
 ---@field shnum integer
 ---@field shstrndx integer
+local M = {}
 
 ---@param hdr Header
 ---@return string
diff --git a/elf/section.lua b/elf/section.lua
index 64a91b2..5e185fd 100644
--- a/elf/section.lua
+++ b/elf/section.lua
@@ -1,14 +1,15 @@
 local fmt = require("elf.fmt")
 
-local M = {}
-
 ---@class Section
 
----@param section Section
+---@class Sections
+local M = {}
+
+---@param sections Sections
 ---@param endian Endian
 ---@return string
 ---@nodiscard
-function M.pack(section, endian)
+function M.pack(sections, endian)
     -- TODO
     return string.pack("B", 0x1)
 end
diff --git a/elf/segment.lua b/elf/segment.lua
index da8e9c6..662f42e 100644
--- a/elf/segment.lua
+++ b/elf/segment.lua
@@ -1,8 +1,6 @@
 local ec = require("elf.constants")
 local fmt = require("elf.fmt")
 
-local M = {}
-
 ---@class Segment
 ---@field type SegmentType
 ---@field flags integer
@@ -13,6 +11,9 @@ local M = {}
 ---@field memsz integer
 ---@field align integer
 
+---@class Segments
+local M = {}
+
 ---@param phdr Segment
 ---@param endian Endian
 ---@return string
diff --git a/mkelf.lua b/mkelf.lua
index 6edeebb..7dd32c6 100644
--- a/mkelf.lua
+++ b/mkelf.lua
@@ -11,9 +11,12 @@ local function usage()
 end
 
 ---@param fn string|nil
----@return Header, Segment[], Section[]
+---@return Header, Segments, Sections
 local function loadconfig(fn)
     local header, segments, sections = {}, {}, {}
+    local header_mt = { __index = elf.header }
+    local segments_mt = { __index = elf.segment }
+    local sections_mt = { __index = elf.section }
     local env = {
         -- Keep in sync with types/elf.d.lua
         Class = elf.Class,
@@ -25,9 +28,9 @@ local function loadconfig(fn)
         SegmentFlags = elf.SegmentFlags,
         ELFVERSION = elf.VERSION,
 
-        header = function(t) header = t end,
-        segments = function(t) segments = t end,
-        sections = function(t) sections = t end,
+        header = function(t) header = setmetatable(t, header_mt) end,
+        segments = function(t) segments = setmetatable(t, segments_mt) end,
+        sections = function(t) sections = setmetatable(t, sections_mt) end,
     }
     -- TODO error check for multiple headers
     local chunk, err = loadfile(fn, "t", env)
@@ -56,10 +59,10 @@ local function main()
     header.phentsize = (header.class == ec.Class.bit64) and 0x38 or 0x20
     -- TODO write to a temp file and atomic rename to outfn.
     local out <close> = assert(io.open(outfn, "wb"))
-    out:write(elf.header.pack(header))
-    out:write(elf.segment.pack(segments, header.data, header.class))
+    out:write(header:pack())
+    out:write(segments:pack(header.data, header.class))
     -- TODO finish section.pack
-    -- out:write(elf.section.pack(c.sections, c.header.data))
+    out:write(sections:pack(header.data))
 end
 
 main()