From 6b53dc946117110907867ee67425585ae3729750 Mon Sep 17 00:00:00 2001
From: Jakub Konka <kubkon@jakubkonka.com>
Date: Mon, 2 Sep 2024 09:08:37 +0200
Subject: [PATCH] elf: actually allocate atoms within each section chunk

---
 src/link/Elf.zig        | 6 +++++-
 src/link/Elf/Object.zig | 8 +++++++-
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/link/Elf.zig b/src/link/Elf.zig
index 752d0082c8..b6efa66247 100644
--- a/src/link/Elf.zig
+++ b/src/link/Elf.zig
@@ -3505,8 +3505,12 @@ fn resetShdrIndexes(self: *Elf, backlinks: []const u32) void {
     }
 
     for (self.objects.items) |index| {
-        for (self.file(index).?.object.section_chunks.items) |*chunk| {
+        const object = self.file(index).?.object;
+        for (object.section_chunks.items) |*chunk| {
             chunk.output_section_index = backlinks[chunk.output_section_index];
+            for (chunk.atoms.items) |atom_index| {
+                object.atom(atom_index).?.output_section_index = chunk.output_section_index;
+            }
         }
     }
 
diff --git a/src/link/Elf/Object.zig b/src/link/Elf/Object.zig
index 590f7b6762..dd58727202 100644
--- a/src/link/Elf/Object.zig
+++ b/src/link/Elf/Object.zig
@@ -975,6 +975,12 @@ pub fn allocateAtoms(self: *Object, elf_file: *Elf) !void {
         shdr.sh_addralign = @max(shdr.sh_addralign, chunk.alignment.toByteUnits().?);
 
         // TODO create back and forward links
+        // TODO if we had a link from Atom to parent Chunk we would not need to update Atom's value or osec index
+        for (chunk.atoms.items) |atom_index| {
+            const atom_ptr = self.atom(atom_index).?;
+            atom_ptr.output_section_index = chunk.output_section_index;
+            atom_ptr.value += chunk.value;
+        }
     }
 }
 
@@ -1008,7 +1014,7 @@ pub fn writeAtoms(self: *Object, elf_file: *Elf) !void {
             const atom_ptr = self.atom(atom_index).?;
             assert(atom_ptr.alive);
 
-            const offset = math.cast(usize, atom_ptr.value) orelse return error.Overflow;
+            const offset = math.cast(usize, atom_ptr.value - chunk.value) orelse return error.Overflow;
             const size = math.cast(usize, atom_ptr.size) orelse return error.Overflow;
 
             log.debug("    * atom({d}) at 0x{x}", .{ atom_index, chunk.offset(elf_file) + offset });