Segments: normalize and validate.

While here mark mandatory and optional fields.

1 files changed, 29 insertions, 7 deletions

diff --git a/elf/segment.lua b/elf/segment.lua
index 662f42e..19cb6d0 100644
--- a/elf/segment.lua
+++ b/elf/segment.lua
@@ -3,17 +3,39 @@ local fmt = require("elf.fmt")
 
 ---@class Segment
 ---@field type SegmentType
----@field flags integer
----@field offset integer
----@field vaddr integer
----@field paddr integer
----@field filesz integer
----@field memsz integer
----@field align integer
+---@field flags? integer
+---@field offset? integer
+---@field vaddr? integer
+---@field paddr? integer
+---@field filesz? integer
+---@field memsz? integer
+---@field align? integer
+---@field first_section? string
+---@field last_section? string
 
 ---@class Segments
 local M = {}
 
+
+function M.normalize(phdrs)
+    for _, phdr in ipairs(phdrs) do
+        phdr.flags = phdr.flags or 0
+        phdr.offset = phdr.offset or 0
+        phdr.vaddr = phdr.vaddr or 0
+        phdr.paddr = phdr.paddr or 0
+        phdr.filesz = phdr.filesz or 0
+        phdr.memsz = phdr.memsz or 0
+        phdr.align = phdr.align or 1
+    end
+end
+
+function M.validate(phdrs)
+    for _, phdr in ipairs(phdrs) do
+        if not phdr.type then error("type is required in segment", 3) end
+        -- TODO additional validations
+    end
+end
+
 ---@param phdr Segment
 ---@param endian Endian
 ---@return string