From 56e1ae21e42b63ea4409b68950691fb89bfd1d21 Mon Sep 17 00:00:00 2001
From: Jakub Konka <kubkon@jakubkonka.com>
Date: Sun, 18 Aug 2024 14:54:12 +0200
Subject: [PATCH] elf: populate debug atoms on the linker side after
 Dwarf.flushModule

---
 src/link/Dwarf.zig         |  2 +-
 src/link/Elf/ZigObject.zig | 37 +++++++++++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/src/link/Dwarf.zig b/src/link/Dwarf.zig
index 60c0bac4a8..f74d8e82a4 100644
--- a/src/link/Dwarf.zig
+++ b/src/link/Dwarf.zig
@@ -201,7 +201,7 @@ const StringSection = struct {
 };
 
 /// A linker section containing a sequence of `Unit`s.
-const Section = struct {
+pub const Section = struct {
     dirty: bool,
     pad_to_ideal: bool,
     alignment: InternPool.Alignment,
diff --git a/src/link/Elf/ZigObject.zig b/src/link/Elf/ZigObject.zig
index f951e7ea71..a82d1f8809 100644
--- a/src/link/Elf/ZigObject.zig
+++ b/src/link/Elf/ZigObject.zig
@@ -181,6 +181,43 @@ pub fn flushModule(self: *ZigObject, elf_file: *Elf, tid: Zcu.PerThread.Id) !voi
         const pt: Zcu.PerThread = .{ .zcu = elf_file.base.comp.module.?, .tid = tid };
         try dwarf.flushModule(pt);
 
+        // TODO invert this logic so that we manage the output section with the atom, not the
+        // other way around
+        for ([_]u32{
+            self.debug_info_index.?,
+            self.debug_abbrev_index.?,
+            self.debug_str_index.?,
+            self.debug_aranges_index.?,
+            self.debug_line_index.?,
+            self.debug_line_str_index.?,
+            self.debug_loclists_index.?,
+            self.debug_rnglists_index.?,
+        }, [_]Dwarf.Section{
+            dwarf.debug_info.section,
+            dwarf.debug_abbrev.section,
+            dwarf.debug_str.section,
+            dwarf.debug_aranges.section,
+            dwarf.debug_line.section,
+            dwarf.debug_line_str.section,
+            dwarf.debug_loclists.section,
+            dwarf.debug_rnglists.section,
+        }) |sym_index, sect| {
+            const sym = self.symbol(sym_index);
+            const atom_ptr = self.atom(sym.ref.index).?;
+            if (!atom_ptr.alive) continue;
+            const shdr = elf_file.shdrs.items[sym.outputShndx(elf_file).?];
+            const esym = &self.symtab.items(.elf_sym)[sym.esym_index];
+            esym.st_size = shdr.sh_size;
+            atom_ptr.size = shdr.sh_size;
+            atom_ptr.alignment = Atom.Alignment.fromNonzeroByteUnits(shdr.sh_addralign);
+
+            const relocs = &self.relocs.items[atom_ptr.relocsShndx().?];
+            _ = relocs;
+            for (sect.units.items) |unit| {
+                _ = unit;
+            }
+        }
+
         self.debug_abbrev_section_dirty = false;
         self.debug_aranges_section_dirty = false;
         self.debug_rnglists_section_dirty = false;