From 68680bbd00ae43cd25d8c613d666bd1554d67131 Mon Sep 17 00:00:00 2001
From: kcbanner <kcbanner@gmail.com>
Date: Sat, 19 Sep 2026 17:06:14 -0400
Subject: [PATCH] link: fix not calling `makeWritable` for dynamic libs during
 updates

---
 src/Compilation.zig |  5 +++--
 src/link.zig        | 22 ++++++++++++++--------
 src/main.zig        | 10 ++--------
 3 files changed, 19 insertions(+), 18 deletions(-)

diff --git a/src/Compilation.zig b/src/Compilation.zig
index d94b7146b59afed2774f83d89b63604794a1ddbd..e7da1d5a790a8ac1c6a5e3f8edaab6341b7b77aa 100644
--- a/src/Compilation.zig
+++ b/src/Compilation.zig
@@ -3528,7 +3528,7 @@ fn emitFromCObject(
 /// Having the file open for writing is problematic as far as executing the
 /// binary is concerned. This will remove the write flag, or close the file,
 /// or whatever is needed so that it can be executed.
-/// After this, one must call` makeFileWritable` before calling `update`.
+/// After this, one must call `makeFileWritable` before calling `update`.
 pub fn makeBinFileExecutable(comp: *Compilation) !void {
     if (!dev.env.supports(.make_executable)) return;
     const lf = comp.bin_file orelse return;
@@ -3537,7 +3537,8 @@ pub fn makeBinFileExecutable(comp: *Compilation) !void {
 
 pub fn makeBinFileWritable(comp: *Compilation) !void {
     const lf = comp.bin_file orelse return;
-    return lf.makeWritable();
+    if (lf.canMakeExecutable())
+        try lf.makeWritable();
 }
 
 const Header = extern struct {
diff --git a/src/link.zig b/src/link.zig
index 0096023099d00dcdd59e42a4e3e1cae12e777e47..8dc5988ee05b247bede01e8e303d1ae9429a9e2c 100644
--- a/src/link.zig
+++ b/src/link.zig
@@ -689,18 +689,24 @@ pub const File = struct {
         return macho.reopenDebugInfo();
     }
 
+    pub fn canMakeExecutable(base: *File) bool {
+        const comp = base.comp;
+        return switch (comp.config.output_mode) {
+            .Obj => false,
+            .Lib => switch (comp.config.link_mode) {
+                .static => false,
+                .dynamic => true,
+            },
+            .Exe => true,
+        };
+    }
+
     pub fn makeExecutable(base: *File) !void {
         dev.check(.make_executable);
         const comp = base.comp;
         const io = comp.io;
-        switch (comp.config.output_mode) {
-            .Obj => return,
-            .Lib => switch (comp.config.link_mode) {
-                .static => return,
-                .dynamic => {},
-            },
-            .Exe => {},
-        }
+        if (!base.canMakeExecutable())
+            return;
         switch (base.tag) {
             .lld => assert(base.file == null),
             .elf => if (base.file) |f| {
diff --git a/src/main.zig b/src/main.zig
index 41b4e841d36f4bfe598cb23fd300d6ffe248b0f8..5323ea936fa88c1a611ef02d69f5855495e92b73 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -4440,12 +4440,8 @@ fn serve(
                     continue;
                 }
 
-                if (comp.config.output_mode == .Exe) {
-                    try comp.makeBinFileWritable();
-                }
-
+                try comp.makeBinFileWritable();
                 try comp.update(main_progress_node);
-
                 try comp.makeBinFileExecutable();
                 try serveUpdateResults(&server, comp);
             },
@@ -4476,9 +4472,7 @@ fn serve(
                     try comp.hotCodeSwap(main_progress_node, pid);
                     try serveUpdateResults(&server, comp);
                 } else {
-                    if (comp.config.output_mode == .Exe) {
-                        try comp.makeBinFileWritable();
-                    }
+                    try comp.makeBinFileWritable();
                     try comp.update(main_progress_node);
                     try comp.makeBinFileExecutable();
                     try serveUpdateResults(&server, comp);
-- 
2.54.0