From 2dd178443abcbd91a923c64a4fd066caef974a82 Mon Sep 17 00:00:00 2001
From: Jakub Konka <kubkon@jakubkonka.com>
Date: Sat, 1 Apr 2023 06:49:01 +0200
Subject: [PATCH] macho: do not assume entrypoint is defined

---
 src/link/MachO/dead_strip.zig | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/src/link/MachO/dead_strip.zig b/src/link/MachO/dead_strip.zig
index cd64e72170..66c644ec04 100644
--- a/src/link/MachO/dead_strip.zig
+++ b/src/link/MachO/dead_strip.zig
@@ -43,15 +43,19 @@ fn collectRoots(zld: *Zld, roots: *AtomTable) !void {
         .Exe => {
             // Add entrypoint as GC root
             const global: SymbolWithLoc = zld.getEntryPoint();
-            const object = zld.objects.items[global.getFile().?];
-            const atom_index = object.getAtomIndexForSymbol(global.sym_index).?; // panic here means fatal error
-            _ = try roots.getOrPut(atom_index);
+            if (global.getFile()) |file| {
+                const object = zld.objects.items[file];
+                const atom_index = object.getAtomIndexForSymbol(global.sym_index).?; // panic here means fatal error
+                _ = try roots.getOrPut(atom_index);
 
-            log.debug("root(ATOM({d}, %{d}, {?d}))", .{
-                atom_index,
-                zld.getAtom(atom_index).sym_index,
-                zld.getAtom(atom_index).getFile(),
-            });
+                log.debug("root(ATOM({d}, %{d}, {?d}))", .{
+                    atom_index,
+                    zld.getAtom(atom_index).sym_index,
+                    zld.getAtom(atom_index).getFile(),
+                });
+            } else {
+                assert(zld.getSymbol(global).undf()); // Stub as our entrypoint is in a dylib.
+            }
         },
         else => |other| {
             assert(other == .Lib);