Commit 0c7b2a7bd5

mlugg <mlugg@mlugg.co.uk>
2025-09-08 15:03:11
fix compiler ftbfs from std.macho and std.dwarf changes
1 parent 202aeac
lib/std/debug/Dwarf/Unwind.zig
@@ -603,13 +603,13 @@ fn readEhPointerAbs(r: *Reader, enc_ty: EH.PE.Type, addr_size_bytes: u8, endian:
 /// Returns `error.InvalidDebugInfo` if the encoding is `EH.PE.omit`.
 fn readEhPointer(r: *Reader, enc: EH.PE, addr_size_bytes: u8, ctx: EhPointerContext, endian: Endian) !u64 {
     const offset = try readEhPointerAbs(r, enc.type, addr_size_bytes, endian);
+    if (enc.indirect) return bad(); // GCC extension; not supported
     const base = switch (enc.rel) {
         .abs, .aligned => 0,
         .pcrel => ctx.pc_rel_base,
         .textrel => ctx.text_rel_base orelse return bad(),
         .datarel => ctx.data_rel_base orelse return bad(),
         .funcrel => ctx.function_rel_base orelse return bad(),
-        .indirect => return bad(), // GCC extension; not supported
         _ => return bad(),
     };
     return switch (offset) {
lib/std/dwarf/EH.zig
@@ -1,6 +1,8 @@
 pub const PE = packed struct(u8) {
     type: Type,
     rel: Rel,
+    /// Undocumented GCC extension
+    indirect: bool = false,
 
     /// This is a special encoding which does not correspond to named `type`/`rel` values.
     pub const omit: PE = @bitCast(@as(u8, 0xFF));
@@ -18,15 +20,15 @@ pub const PE = packed struct(u8) {
         _,
     };
 
-    pub const Rel = enum(u4) {
+    /// The specification considers this a `u4`, but the GCC `indirect` field extension conflicts
+    /// with that, so we consider it a `u3` instead.
+    pub const Rel = enum(u3) {
         abs = 0x0,
         pcrel = 0x1,
         textrel = 0x2,
         datarel = 0x3,
         funcrel = 0x4,
         aligned = 0x5,
-        /// Undocumented GCC extension
-        indirect = 0x8,
         _,
     };
 };
src/link/Elf/eh_frame.zig
@@ -456,10 +456,10 @@ pub fn writeEhFrameRelocs(elf_file: *Elf, relocs: *std.array_list.Managed(elf.El
 
 pub fn writeEhFrameHdr(elf_file: *Elf, writer: anytype) !void {
     try writer.writeByte(1); // version
-    try writer.writeByte(DW_EH_PE.pcrel | DW_EH_PE.sdata4); // eh_frame_ptr_enc
+    try writer.writeByte(@bitCast(@as(DW_EH_PE, .{ .type = .sdata4, .rel = .pcrel }))); // eh_frame_ptr_enc
     // Building the lookup table would be expensive work on every `flush` -- omit it.
-    try writer.writeByte(DW_EH_PE.omit); // fde_count_enc
-    try writer.writeByte(DW_EH_PE.omit); // table_enc
+    try writer.writeByte(@bitCast(DW_EH_PE.omit)); // fde_count_enc
+    try writer.writeByte(@bitCast(DW_EH_PE.omit)); // table_enc
 
     const shdrs = elf_file.sections.items(.shdr);
     const eh_frame_shdr = shdrs[elf_file.section_indexes.eh_frame.?];
src/link/MachO/eh_frame.zig
@@ -26,24 +26,24 @@ pub const Cie = struct {
 
         for (aug[1..]) |ch| switch (ch) {
             'R' => {
-                const enc = try reader.takeByte();
-                if (enc != DW_EH_PE.pcrel | DW_EH_PE.absptr) {
+                const enc: DW.EH.PE = @bitCast(try reader.takeByte());
+                if (enc != @as(DW.EH.PE, .{ .type = .absptr, .rel = .pcrel })) {
                     @panic("unexpected pointer encoding"); // TODO error
                 }
             },
             'P' => {
-                const enc = try reader.takeByte();
-                if (enc != DW_EH_PE.pcrel | DW_EH_PE.indirect | DW_EH_PE.sdata4) {
+                const enc: DW.EH.PE = @bitCast(try reader.takeByte());
+                if (enc != @as(DW.EH.PE, .{ .type = .sdata4, .rel = .pcrel, .indirect = true })) {
                     @panic("unexpected personality pointer encoding"); // TODO error
                 }
                 _ = try reader.takeInt(u32, .little); // personality pointer
             },
             'L' => {
-                const enc = try reader.takeByte();
-                switch (enc & DW_EH_PE.type_mask) {
-                    DW_EH_PE.sdata4 => cie.lsda_size = .p32,
-                    DW_EH_PE.absptr => cie.lsda_size = .p64,
-                    else => unreachable, // TODO error
+                const enc: DW.EH.PE = @bitCast(try reader.takeByte());
+                switch (enc.type) {
+                    .sdata4 => cie.lsda_size = .p32,
+                    .absptr => cie.lsda_size = .p64,
+                    else => @panic("unexpected lsda encoding"), // TODO error
                 }
             },
             else => @panic("unexpected augmentation string"), // TODO error
@@ -505,7 +505,7 @@ const Writer = std.Io.Writer;
 
 const Allocator = std.mem.Allocator;
 const Atom = @import("Atom.zig");
-const DW_EH_PE = std.dwarf.EH.PE;
+const DW = std.dwarf;
 const File = @import("file.zig").File;
 const MachO = @import("../MachO.zig");
 const Object = @import("Object.zig");
src/link/MachO/file.zig
@@ -192,21 +192,21 @@ pub const File = union(enum) {
         assert(file == .object or file == .zig_object);
 
         for (file.getSymbols(), file.getNlists(), 0..) |*sym, nlist, i| {
-            if (!nlist.ext()) continue;
-            if (!nlist.undf()) continue;
+            if (!nlist.n_type.bits.ext) continue;
+            if (nlist.n_type.bits.type != .undf) continue;
 
             if (file.getSymbolRef(@intCast(i), macho_file).getFile(macho_file) != null) continue;
 
             const is_import = switch (macho_file.undefined_treatment) {
                 .@"error" => false,
-                .warn, .suppress => nlist.weakRef(),
+                .warn, .suppress => nlist.n_desc.weak_ref,
                 .dynamic_lookup => true,
             };
             if (is_import) {
                 sym.value = 0;
                 sym.atom_ref = .{ .index = 0, .file = 0 };
                 sym.flags.weak = false;
-                sym.flags.weak_ref = nlist.weakRef();
+                sym.flags.weak_ref = nlist.n_desc.weak_ref;
                 sym.flags.import = is_import;
                 sym.visibility = .global;
 
@@ -223,13 +223,13 @@ pub const File = union(enum) {
         assert(file == .object or file == .zig_object);
 
         for (file.getSymbols(), file.getNlists(), 0..) |*sym, nlist, i| {
-            if (!nlist.ext()) continue;
-            if (!nlist.undf()) continue;
+            if (!nlist.n_type.bits.ext) continue;
+            if (nlist.n_type.bits.type != .undf) continue;
             if (file.getSymbolRef(@intCast(i), macho_file).getFile(macho_file) != null) continue;
 
             sym.value = 0;
             sym.atom_ref = .{ .index = 0, .file = 0 };
-            sym.flags.weak_ref = nlist.weakRef();
+            sym.flags.weak_ref = nlist.n_desc.weak_ref;
             sym.flags.import = true;
             sym.visibility = .global;
 
@@ -247,7 +247,7 @@ pub const File = union(enum) {
         for (file.getSymbols(), file.getNlists(), 0..) |sym, nlist, i| {
             if (sym.visibility != .global) continue;
             if (sym.flags.weak) continue;
-            if (nlist.undf()) continue;
+            if (nlist.n_type.bits.type == .undf) continue;
             const ref = file.getSymbolRef(@intCast(i), macho_file);
             const ref_file = ref.getFile(macho_file) orelse continue;
             if (ref_file.getIndex() == file.getIndex()) continue;
src/link/MachO/InternalObject.zig
@@ -69,9 +69,9 @@ pub fn initSymbols(self: *InternalObject, macho_file: *MachO) !void {
             const nlist = obj.symtab.addOneAssumeCapacity();
             nlist.* = .{
                 .n_strx = name.pos,
-                .n_type = args.type,
+                .n_type = @bitCast(args.type),
                 .n_sect = 0,
-                .n_desc = args.desc,
+                .n_desc = @bitCast(args.desc),
                 .n_value = 0,
             };
             symbol.nlist_idx = nlist_idx;
@@ -143,7 +143,7 @@ pub fn resolveSymbols(self: *InternalObject, macho_file: *MachO) !void {
         }
         global.* = gop.index;
 
-        if (nlist.undf()) continue;
+        if (nlist.n_type.bits.type == .undf) continue;
         if (gop.ref.getFile(macho_file) == null) {
             gop.ref.* = .{ .index = @intCast(i), .file = self.index };
             continue;
@@ -171,7 +171,7 @@ pub fn resolveBoundarySymbols(self: *InternalObject, macho_file: *MachO) !void {
         const object = macho_file.getFile(index).?.object;
         for (object.symbols.items, 0..) |sym, i| {
             const nlist = object.symtab.items(.nlist)[i];
-            if (!nlist.undf() or !nlist.ext()) continue;
+            if (nlist.n_type.bits.type != .undf or !nlist.n_type.bits.ext) continue;
             const ref = object.getSymbolRef(@intCast(i), macho_file);
             if (ref.getFile(macho_file) != null) continue;
             const name = sym.getName(macho_file);
@@ -206,9 +206,9 @@ pub fn resolveBoundarySymbols(self: *InternalObject, macho_file: *MachO) !void {
         const nlist = self.symtab.addOneAssumeCapacity();
         nlist.* = .{
             .n_strx = name_str.pos,
-            .n_type = macho.N_SECT,
+            .n_type = .{ .bits = .{ .ext = false, .type = .sect, .pext = false, .is_stab = 0 } },
             .n_sect = 0,
-            .n_desc = 0,
+            .n_desc = @bitCast(@as(u16, 0)),
             .n_value = 0,
         };
         sym.nlist_idx = nlist_idx;
@@ -226,7 +226,7 @@ pub fn markLive(self: *InternalObject, macho_file: *MachO) void {
 
     for (0..self.symbols.items.len) |i| {
         const nlist = self.symtab.items[i];
-        if (!nlist.ext()) continue;
+        if (!nlist.n_type.bits.ext) continue;
 
         const ref = self.getSymbolRef(@intCast(i), macho_file);
         const file = ref.getFile(macho_file) orelse continue;
@@ -273,9 +273,9 @@ fn addObjcMethnameSection(self: *InternalObject, methname: []const u8, macho_fil
     const nlist = try self.symtab.addOne(gpa);
     nlist.* = .{
         .n_strx = name_str.pos,
-        .n_type = macho.N_SECT,
+        .n_type = .{ .bits = .{ .ext = false, .type = .sect, .pext = false, .is_stab = 0 } },
         .n_sect = @intCast(n_sect + 1),
-        .n_desc = 0,
+        .n_desc = @bitCast(@as(u16, 0)),
         .n_value = 0,
     };
     sym.nlist_idx = nlist_idx;
@@ -326,9 +326,9 @@ fn addObjcSelrefsSection(self: *InternalObject, methname_sym_index: Symbol.Index
     const nlist = try self.symtab.addOne(gpa);
     nlist.* = .{
         .n_strx = 0,
-        .n_type = macho.N_SECT,
+        .n_type = .{ .bits = .{ .ext = false, .type = .sect, .pext = false, .is_stab = 0 } },
         .n_sect = @intCast(n_sect + 1),
-        .n_desc = 0,
+        .n_desc = @bitCast(@as(u16, 0)),
         .n_value = 0,
     };
     sym.nlist_idx = nlist_idx;
@@ -352,8 +352,8 @@ pub fn resolveObjcMsgSendSymbols(self: *InternalObject, macho_file: *MachO) !voi
 
         for (object.symbols.items, 0..) |sym, i| {
             const nlist = object.symtab.items(.nlist)[i];
-            if (!nlist.ext()) continue;
-            if (!nlist.undf()) continue;
+            if (!nlist.n_type.bits.ext) continue;
+            if (nlist.n_type.bits.type != .undf) continue;
 
             const ref = object.getSymbolRef(@intCast(i), macho_file);
             if (ref.getFile(macho_file) != null) continue;
@@ -381,9 +381,9 @@ pub fn resolveObjcMsgSendSymbols(self: *InternalObject, macho_file: *MachO) !voi
         const nlist = try self.symtab.addOne(gpa);
         nlist.* = .{
             .n_strx = name_str.pos,
-            .n_type = macho.N_SECT | macho.N_EXT | macho.N_PEXT,
+            .n_type = .{ .bits = .{ .ext = true, .type = .sect, .pext = true, .is_stab = 0 } },
             .n_sect = 0,
-            .n_desc = 0,
+            .n_desc = @bitCast(@as(u16, 0)),
             .n_value = 0,
         };
         sym.nlist_idx = nlist_idx;
src/link/MachO/Object.zig
@@ -179,7 +179,7 @@ pub fn parse(self: *Object, macho_file: *MachO) !void {
         idx: usize,
 
         fn rank(ctx: *const Object, nl: macho.nlist_64) u8 {
-            if (!nl.ext()) {
+            if (!nl.n_type.bits.ext) {
                 const name = ctx.getNStrx(nl.n_strx);
                 if (name.len == 0) return 5;
                 if (name[0] == 'l' or name[0] == 'L') return 4;
@@ -202,7 +202,7 @@ pub fn parse(self: *Object, macho_file: *MachO) !void {
     var nlists = try std.array_list.Managed(NlistIdx).initCapacity(gpa, self.symtab.items(.nlist).len);
     defer nlists.deinit();
     for (self.symtab.items(.nlist), 0..) |nlist, i| {
-        if (nlist.n_type.bits.is_stab != 0 or nlist.n_type.type != .sect) continue;
+        if (nlist.n_type.bits.is_stab != 0 or nlist.n_type.bits.type != .sect) continue;
         nlists.appendAssumeCapacity(.{ .nlist = nlist, .idx = i });
     }
     mem.sort(NlistIdx, nlists.items, self, NlistIdx.lessThan);
@@ -488,9 +488,9 @@ fn initCstringLiterals(self: *Object, allocator: Allocator, file: File.Handle, m
             self.symtab.set(nlist_index, .{
                 .nlist = .{
                     .n_strx = name_str.pos,
-                    .n_type = macho.N_SECT,
+                    .n_type = .{ .bits = .{ .ext = false, .type = .sect, .pext = false, .is_stab = 0 } },
                     .n_sect = @intCast(atom.n_sect + 1),
-                    .n_desc = 0,
+                    .n_desc = @bitCast(@as(u16, 0)),
                     .n_value = atom.getInputAddress(macho_file),
                 },
                 .size = atom.size,
@@ -555,9 +555,9 @@ fn initFixedSizeLiterals(self: *Object, allocator: Allocator, macho_file: *MachO
             self.symtab.set(nlist_index, .{
                 .nlist = .{
                     .n_strx = name_str.pos,
-                    .n_type = macho.N_SECT,
+                    .n_type = .{ .bits = .{ .ext = false, .type = .sect, .pext = false, .is_stab = 0 } },
                     .n_sect = @intCast(atom.n_sect + 1),
-                    .n_desc = 0,
+                    .n_desc = @bitCast(@as(u16, 0)),
                     .n_value = atom.getInputAddress(macho_file),
                 },
                 .size = atom.size,
@@ -613,9 +613,9 @@ fn initPointerLiterals(self: *Object, allocator: Allocator, macho_file: *MachO)
             self.symtab.set(nlist_index, .{
                 .nlist = .{
                     .n_strx = name_str.pos,
-                    .n_type = macho.N_SECT,
+                    .n_type = .{ .bits = .{ .ext = false, .type = .sect, .pext = false, .is_stab = 0 } },
                     .n_sect = @intCast(atom.n_sect + 1),
-                    .n_desc = 0,
+                    .n_desc = @bitCast(@as(u16, 0)),
                     .n_value = atom.getInputAddress(macho_file),
                 },
                 .size = atom.size,
@@ -805,7 +805,7 @@ fn linkNlistToAtom(self: *Object, macho_file: *MachO) !void {
     const tracy = trace(@src());
     defer tracy.end();
     for (self.symtab.items(.nlist), self.symtab.items(.atom)) |nlist, *atom| {
-        if (!nlist.n_type.bits.is_stab != 0 and nlist.n_type.type == .sect) {
+        if (nlist.n_type.bits.is_stab == 0 and nlist.n_type.bits.type == .sect) {
             const sect = self.sections.items(.header)[nlist.n_sect - 1];
             const subs = self.sections.items(.subsections)[nlist.n_sect - 1].items;
             if (nlist.n_value == sect.addr) {
@@ -852,30 +852,30 @@ fn initSymbols(self: *Object, allocator: Allocator, macho_file: *MachO) !void {
         symbol.extra = self.addSymbolExtraAssumeCapacity(.{});
 
         if (self.getAtom(atom_index)) |atom| {
-            assert(nlist.n_type.type != .abs);
+            assert(nlist.n_type.bits.type != .abs);
             symbol.value -= atom.getInputAddress(macho_file);
             symbol.atom_ref = .{ .index = atom_index, .file = self.index };
         }
 
         symbol.flags.weak = nlist.n_desc.weak_def_or_ref_to_weak;
-        symbol.flags.abs = nlist.n_type.type == .abs;
+        symbol.flags.abs = nlist.n_type.bits.type == .abs;
         symbol.flags.tentative = nlist.tentative();
         symbol.flags.no_dead_strip = symbol.flags.no_dead_strip or nlist.n_desc.discarded_or_no_dead_strip;
-        symbol.flags.dyn_ref = nlist.n_desc & macho.REFERENCED_DYNAMICALLY != 0;
+        symbol.flags.dyn_ref = nlist.n_desc.referenced_dynamically;
         symbol.flags.interposable = false;
         // TODO
-        // symbol.flags.interposable = nlist.ext() and (nlist.n_type.type == .sect or nlist.n_type.type == .abs) and macho_file.base.isDynLib() and macho_file.options.namespace == .flat and !nlist.pext();
+        // symbol.flags.interposable = nlist.ext() and (nlist.n_type.bits.type == .sect or nlist.n_type.bits.type == .abs) and macho_file.base.isDynLib() and macho_file.options.namespace == .flat and !nlist.pext();
 
-        if (nlist.n_type.type == .sect and
+        if (nlist.n_type.bits.type == .sect and
             self.sections.items(.header)[nlist.n_sect - 1].type() == macho.S_THREAD_LOCAL_VARIABLES)
         {
             symbol.flags.tlv = true;
         }
 
-        if (nlist.ext()) {
-            if (nlist.n_type.type == .undf) {
+        if (nlist.n_type.bits.ext) {
+            if (nlist.n_type.bits.type == .undf) {
                 symbol.flags.weak_ref = nlist.n_desc.weak_ref;
-            } else if (nlist.pext() or (nlist.n_desc.weak_def_or_ref_to_weak and nlist.n_desc.weak_ref) or self.hidden) {
+            } else if (nlist.n_type.bits.pext or (nlist.n_desc.weak_def_or_ref_to_weak and nlist.n_desc.weak_ref) or self.hidden) {
                 symbol.visibility = .hidden;
             } else {
                 symbol.visibility = .global;
@@ -919,7 +919,7 @@ fn initSymbolStabs(self: *Object, allocator: Allocator, nlists: anytype, macho_f
     var addr_lookup = std.StringHashMap(u64).init(allocator);
     defer addr_lookup.deinit();
     for (syms) |sym| {
-        if (sym.n_type.type == .sect and (sym.ext() or sym.pext())) {
+        if (sym.n_type.bits.type == .sect and (sym.n_type.bits.ext or sym.n_type.bits.pext)) {
             try addr_lookup.putNoClobber(self.getNStrx(sym.n_strx), sym.n_value);
         }
     }
@@ -927,41 +927,43 @@ fn initSymbolStabs(self: *Object, allocator: Allocator, nlists: anytype, macho_f
     var i: u32 = start;
     while (i < end) : (i += 1) {
         const open = syms[i];
-        if (open.n_type != macho.N_SO) {
+        if (open.n_type.stab != .so) {
             try macho_file.reportParseError2(self.index, "unexpected symbol stab type 0x{x} as the first entry", .{
-                open.n_type,
+                @intFromEnum(open.n_type.stab),
             });
             return error.MalformedObject;
         }
 
-        while (i < end and syms[i].n_type == macho.N_SO and syms[i].n_sect != 0) : (i += 1) {}
+        while (i < end and syms[i].n_type.stab == .so and syms[i].n_sect != 0) : (i += 1) {}
 
         var sf: StabFile = .{ .comp_dir = i };
         // TODO validate
         i += 3;
 
-        while (i < end and syms[i].n_type != macho.N_SO) : (i += 1) {
+        while (i < end and syms[i].n_type.stab != .so) : (i += 1) {
             const nlist = syms[i];
             var stab: StabFile.Stab = .{};
-            switch (nlist.n_type) {
-                macho.N_BNSYM => {
+            switch (nlist.n_type.stab) {
+                .bnsym => {
                     stab.is_func = true;
                     stab.index = sym_lookup.find(nlist.n_value);
                     // TODO validate
                     i += 3;
                 },
-                macho.N_GSYM => {
+                .gsym => {
                     stab.is_func = false;
                     stab.index = sym_lookup.find(addr_lookup.get(self.getNStrx(nlist.n_strx)).?);
                 },
-                macho.N_STSYM => {
+                .stsym => {
                     stab.is_func = false;
                     stab.index = sym_lookup.find(nlist.n_value);
                 },
+                _ => {
+                    try macho_file.reportParseError2(self.index, "unhandled symbol stab type 0x{x}", .{@intFromEnum(nlist.n_type.stab)});
+                    return error.MalformedObject;
+                },
                 else => {
-                    try macho_file.reportParseError2(self.index, "unhandled symbol stab type 0x{x}", .{
-                        nlist.n_type,
-                    });
+                    try macho_file.reportParseError2(self.index, "unhandled symbol stab type '{t}'", .{nlist.n_type.stab});
                     return error.MalformedObject;
                 },
             }
@@ -1132,7 +1134,7 @@ fn initUnwindRecords(self: *Object, allocator: Allocator, sect_id: u8, file: Fil
         fn find(fs: @This(), addr: u64) ?Symbol.Index {
             for (0..fs.ctx.symbols.items.len) |i| {
                 const nlist = fs.ctx.symtab.items(.nlist)[i];
-                if (nlist.ext() and nlist.n_value == addr) return @intCast(i);
+                if (nlist.n_type.bits.ext and nlist.n_value == addr) return @intCast(i);
             }
             return null;
         }
@@ -1242,7 +1244,7 @@ fn parseUnwindRecords(self: *Object, allocator: Allocator, cpu_arch: std.Target.
     const slice = self.symtab.slice();
     for (slice.items(.nlist), slice.items(.atom), slice.items(.size)) |nlist, atom, size| {
         if (nlist.n_type.bits.is_stab != 0) continue;
-        if (nlist.n_type.type != .sect) continue;
+        if (nlist.n_type.bits.type != .sect) continue;
         const sect = self.sections.items(.header)[nlist.n_sect - 1];
         if (sect.isCode() and sect.size > 0) {
             try superposition.ensureUnusedCapacity(1);
@@ -1458,8 +1460,8 @@ pub fn resolveSymbols(self: *Object, macho_file: *MachO) !void {
     const gpa = macho_file.base.comp.gpa;
 
     for (self.symtab.items(.nlist), self.symtab.items(.atom), self.globals.items, 0..) |nlist, atom_index, *global, i| {
-        if (!nlist.ext()) continue;
-        if (nlist.n_type.type == .sect) {
+        if (!nlist.n_type.bits.ext) continue;
+        if (nlist.n_type.bits.type == .sect) {
             const atom = self.getAtom(atom_index).?;
             if (!atom.isAlive()) continue;
         }
@@ -1473,7 +1475,7 @@ pub fn resolveSymbols(self: *Object, macho_file: *MachO) !void {
         }
         global.* = gop.index;
 
-        if (nlist.n_type.type == .undf and !nlist.tentative()) continue;
+        if (nlist.n_type.bits.type == .undf and !nlist.tentative()) continue;
         if (gop.ref.getFile(macho_file) == null) {
             gop.ref.* = .{ .index = @intCast(i), .file = self.index };
             continue;
@@ -1495,12 +1497,12 @@ pub fn markLive(self: *Object, macho_file: *MachO) void {
 
     for (0..self.symbols.items.len) |i| {
         const nlist = self.symtab.items(.nlist)[i];
-        if (!nlist.ext()) continue;
+        if (!nlist.n_type.bits.ext) continue;
 
         const ref = self.getSymbolRef(@intCast(i), macho_file);
         const file = ref.getFile(macho_file) orelse continue;
         const sym = ref.getSymbol(macho_file).?;
-        const should_keep = nlist.n_type.type == .undf or (nlist.tentative() and !sym.flags.tentative);
+        const should_keep = nlist.n_type.bits.type == .undf or (nlist.tentative() and !sym.flags.tentative);
         if (should_keep and file == .object and !file.object.alive) {
             file.object.alive = true;
             file.object.markLive(macho_file);
@@ -1565,7 +1567,7 @@ pub fn convertTentativeDefinitions(self: *Object, macho_file: *MachO) !void {
         const name = try std.fmt.allocPrintSentinel(gpa, "__DATA$__common${s}", .{sym.getName(macho_file)}, 0);
         defer gpa.free(name);
 
-        const alignment = (nlist.n_desc >> 8) & 0x0f;
+        const alignment = (@as(u16, @bitCast(nlist.n_desc)) >> 8) & 0x0f;
         const n_sect = try self.addSection(gpa, "__DATA", "__common");
         const atom_index = try self.addAtom(gpa, .{
             .name = try self.addString(gpa, name),
@@ -1589,9 +1591,9 @@ pub fn convertTentativeDefinitions(self: *Object, macho_file: *MachO) !void {
         sym.visibility = .global;
 
         nlist.n_value = 0;
-        nlist.n_type = macho.N_EXT | macho.N_SECT;
+        nlist.n_type = .{ .bits = .{ .ext = true, .type = .sect, .pext = false, .is_stab = 0 } };
         nlist.n_sect = 0;
-        nlist.n_desc = 0;
+        nlist.n_desc = @bitCast(@as(u16, 0));
         nlist_atom.* = atom_index;
     }
 }
@@ -1685,7 +1687,7 @@ pub fn parseAr(self: *Object, macho_file: *MachO) !void {
 pub fn updateArSymtab(self: Object, ar_symtab: *Archive.ArSymtab, macho_file: *MachO) error{OutOfMemory}!void {
     const gpa = macho_file.base.comp.gpa;
     for (self.symtab.items(.nlist)) |nlist| {
-        if (!nlist.ext() or (nlist.n_type.type == .undf and !nlist.tentative())) continue;
+        if (!nlist.n_type.bits.ext or (nlist.n_type.bits.type == .undf and !nlist.tentative())) continue;
         const off = try ar_symtab.strtab.insert(gpa, self.getNStrx(nlist.n_strx));
         try ar_symtab.entries.append(gpa, .{ .off = off, .file = self.index });
     }
@@ -2028,30 +2030,30 @@ pub fn writeStabs(self: Object, stroff: u32, macho_file: *MachO, ctx: anytype) v
         ) void {
             context.symtab.items[index] = .{
                 .n_strx = 0,
-                .n_type = macho.N_BNSYM,
+                .n_type = .{ .stab = .bnsym },
                 .n_sect = n_sect,
-                .n_desc = 0,
+                .n_desc = @bitCast(@as(u16, 0)),
                 .n_value = n_value,
             };
             context.symtab.items[index + 1] = .{
                 .n_strx = n_strx,
-                .n_type = macho.N_FUN,
+                .n_type = .{ .stab = .fun },
                 .n_sect = n_sect,
-                .n_desc = 0,
+                .n_desc = @bitCast(@as(u16, 0)),
                 .n_value = n_value,
             };
             context.symtab.items[index + 2] = .{
                 .n_strx = 0,
-                .n_type = macho.N_FUN,
+                .n_type = .{ .stab = .fun },
                 .n_sect = 0,
-                .n_desc = 0,
+                .n_desc = @bitCast(@as(u16, 0)),
                 .n_value = size,
             };
             context.symtab.items[index + 3] = .{
                 .n_strx = 0,
-                .n_type = macho.N_ENSYM,
+                .n_type = .{ .stab = .ensym },
                 .n_sect = n_sect,
-                .n_desc = 0,
+                .n_desc = @bitCast(@as(u16, 0)),
                 .n_value = size,
             };
         }
@@ -2068,9 +2070,9 @@ pub fn writeStabs(self: Object, stroff: u32, macho_file: *MachO, ctx: anytype) v
         // N_SO comp_dir
         ctx.symtab.items[index] = .{
             .n_strx = n_strx,
-            .n_type = macho.N_SO,
+            .n_type = .{ .stab = .so },
             .n_sect = 0,
-            .n_desc = 0,
+            .n_desc = @bitCast(@as(u16, 0)),
             .n_value = 0,
         };
         index += 1;
@@ -2081,9 +2083,9 @@ pub fn writeStabs(self: Object, stroff: u32, macho_file: *MachO, ctx: anytype) v
         // N_SO tu_name
         macho_file.symtab.items[index] = .{
             .n_strx = n_strx,
-            .n_type = macho.N_SO,
+            .n_type = .{ .stab = .so },
             .n_sect = 0,
-            .n_desc = 0,
+            .n_desc = @bitCast(@as(u16, 0)),
             .n_value = 0,
         };
         index += 1;
@@ -2094,9 +2096,9 @@ pub fn writeStabs(self: Object, stroff: u32, macho_file: *MachO, ctx: anytype) v
         // N_OSO path
         ctx.symtab.items[index] = .{
             .n_strx = n_strx,
-            .n_type = macho.N_OSO,
+            .n_type = .{ .stab = .oso },
             .n_sect = 0,
-            .n_desc = 1,
+            .n_desc = @bitCast(@as(u16, 1)),
             .n_value = self.mtime,
         };
         index += 1;
@@ -2159,18 +2161,18 @@ pub fn writeStabs(self: Object, stroff: u32, macho_file: *MachO, ctx: anytype) v
             } else if (sym.visibility == .global) {
                 ctx.symtab.items[index] = .{
                     .n_strx = sym_n_strx,
-                    .n_type = macho.N_GSYM,
+                    .n_type = .{ .stab = .gsym },
                     .n_sect = sym_n_sect,
-                    .n_desc = 0,
+                    .n_desc = @bitCast(@as(u16, 0)),
                     .n_value = 0,
                 };
                 index += 1;
             } else {
                 ctx.symtab.items[index] = .{
                     .n_strx = sym_n_strx,
-                    .n_type = macho.N_STSYM,
+                    .n_type = .{ .stab = .stsym },
                     .n_sect = sym_n_sect,
-                    .n_desc = 0,
+                    .n_desc = @bitCast(@as(u16, 0)),
                     .n_value = sym_n_value,
                 };
                 index += 1;
@@ -2181,9 +2183,9 @@ pub fn writeStabs(self: Object, stroff: u32, macho_file: *MachO, ctx: anytype) v
         // N_SO
         ctx.symtab.items[index] = .{
             .n_strx = 0,
-            .n_type = macho.N_SO,
+            .n_type = .{ .stab = .so },
             .n_sect = 0,
-            .n_desc = 0,
+            .n_desc = @bitCast(@as(u16, 0)),
             .n_value = 0,
         };
     } else {
@@ -2198,9 +2200,9 @@ pub fn writeStabs(self: Object, stroff: u32, macho_file: *MachO, ctx: anytype) v
             // N_SO comp_dir
             ctx.symtab.items[index] = .{
                 .n_strx = n_strx,
-                .n_type = macho.N_SO,
+                .n_type = .{ .stab = .so },
                 .n_sect = 0,
-                .n_desc = 0,
+                .n_desc = @bitCast(@as(u16, 0)),
                 .n_value = 0,
             };
             index += 1;
@@ -2211,9 +2213,9 @@ pub fn writeStabs(self: Object, stroff: u32, macho_file: *MachO, ctx: anytype) v
             // N_SO tu_name
             ctx.symtab.items[index] = .{
                 .n_strx = n_strx,
-                .n_type = macho.N_SO,
+                .n_type = .{ .stab = .so },
                 .n_sect = 0,
-                .n_desc = 0,
+                .n_desc = @bitCast(@as(u16, 0)),
                 .n_value = 0,
             };
             index += 1;
@@ -2224,9 +2226,9 @@ pub fn writeStabs(self: Object, stroff: u32, macho_file: *MachO, ctx: anytype) v
             // N_OSO path
             ctx.symtab.items[index] = .{
                 .n_strx = n_strx,
-                .n_type = macho.N_OSO,
+                .n_type = .{ .stab = .so },
                 .n_sect = 0,
-                .n_desc = 1,
+                .n_desc = @bitCast(@as(u16, 1)),
                 .n_value = sf.getOsoModTime(self),
             };
             index += 1;
@@ -2254,18 +2256,18 @@ pub fn writeStabs(self: Object, stroff: u32, macho_file: *MachO, ctx: anytype) v
                 } else if (sym.visibility == .global) {
                     ctx.symtab.items[index] = .{
                         .n_strx = sym_n_strx,
-                        .n_type = macho.N_GSYM,
+                        .n_type = .{ .stab = .gsym },
                         .n_sect = sym_n_sect,
-                        .n_desc = 0,
+                        .n_desc = @bitCast(@as(u16, 0)),
                         .n_value = 0,
                     };
                     index += 1;
                 } else {
                     ctx.symtab.items[index] = .{
                         .n_strx = sym_n_strx,
-                        .n_type = macho.N_STSYM,
+                        .n_type = .{ .stab = .stsym },
                         .n_sect = sym_n_sect,
-                        .n_desc = 0,
+                        .n_desc = @bitCast(@as(u16, 0)),
                         .n_value = sym_n_value,
                     };
                     index += 1;
@@ -2276,9 +2278,9 @@ pub fn writeStabs(self: Object, stroff: u32, macho_file: *MachO, ctx: anytype) v
             // N_SO
             ctx.symtab.items[index] = .{
                 .n_strx = 0,
-                .n_type = macho.N_SO,
+                .n_type = .{ .stab = .so },
                 .n_sect = 0,
-                .n_desc = 0,
+                .n_desc = @bitCast(@as(u16, 0)),
                 .n_value = 0,
             };
             index += 1;
src/link/MachO/Symbol.zig
@@ -36,7 +36,7 @@ pub fn isLocal(symbol: Symbol) bool {
 pub fn isSymbolStab(symbol: Symbol, macho_file: *MachO) bool {
     const file = symbol.getFile(macho_file) orelse return false;
     return switch (file) {
-        .object => symbol.getNlist(macho_file).stab(),
+        .object => symbol.getNlist(macho_file).n_type.bits.is_stab != 0,
         else => false,
     };
 }
@@ -233,35 +233,49 @@ pub inline fn setExtra(symbol: Symbol, extra: Extra, macho_file: *MachO) void {
 
 pub fn setOutputSym(symbol: Symbol, macho_file: *MachO, out: *macho.nlist_64) void {
     if (symbol.isLocal()) {
-        out.n_type = if (symbol.flags.abs) macho.N_ABS else macho.N_SECT;
+        out.n_type = .{ .bits = .{
+            .ext = false,
+            .type = if (symbol.flags.abs) .abs else .sect,
+            .pext = false,
+            .is_stab = 0,
+        } };
         out.n_sect = if (symbol.flags.abs) 0 else @intCast(symbol.getOutputSectionIndex(macho_file) + 1);
-        out.n_desc = 0;
+        out.n_desc = @bitCast(@as(u16, 0));
         out.n_value = symbol.getAddress(.{ .stubs = false }, macho_file);
 
         switch (symbol.visibility) {
-            .hidden => out.n_type |= macho.N_PEXT,
+            .hidden => out.n_type.bits.pext = true,
             else => {},
         }
     } else if (symbol.flags.@"export") {
         assert(symbol.visibility == .global);
-        out.n_type = macho.N_EXT;
-        out.n_type |= if (symbol.flags.abs) macho.N_ABS else macho.N_SECT;
+        out.n_type = .{ .bits = .{
+            .ext = true,
+            .type = if (symbol.flags.abs) .abs else .sect,
+            .pext = false,
+            .is_stab = 0,
+        } };
         out.n_sect = if (symbol.flags.abs) 0 else @intCast(symbol.getOutputSectionIndex(macho_file) + 1);
         out.n_value = symbol.getAddress(.{ .stubs = false }, macho_file);
-        out.n_desc = 0;
+        out.n_desc = @bitCast(@as(u16, 0));
 
         if (symbol.flags.weak) {
-            out.n_desc |= macho.N_WEAK_DEF;
+            out.n_desc.weak_def_or_ref_to_weak = true;
         }
         if (symbol.flags.dyn_ref) {
-            out.n_desc |= macho.REFERENCED_DYNAMICALLY;
+            out.n_desc.referenced_dynamically = true;
         }
     } else {
         assert(symbol.visibility == .global);
-        out.n_type = macho.N_EXT;
+        out.n_type = .{ .bits = .{
+            .ext = true,
+            .type = .undf,
+            .pext = false,
+            .is_stab = 0,
+        } };
         out.n_sect = 0;
         out.n_value = 0;
-        out.n_desc = 0;
+        out.n_desc = @bitCast(@as(u16, 0));
 
         // TODO:
         // const ord: u16 = if (macho_file.options.namespace == .flat)
@@ -274,14 +288,14 @@ pub fn setOutputSym(symbol: Symbol, macho_file: *MachO, out: *macho.nlist_64) vo
             ord
         else
             macho.BIND_SPECIAL_DYLIB_SELF;
-        out.n_desc = macho.N_SYMBOL_RESOLVER * ord;
+        out.n_desc = @bitCast(macho.N_SYMBOL_RESOLVER * ord);
 
         if (symbol.flags.weak) {
-            out.n_desc |= macho.N_WEAK_DEF;
+            out.n_desc.weak_def_or_ref_to_weak = true;
         }
 
         if (symbol.weakRef(macho_file)) {
-            out.n_desc |= macho.N_WEAK_REF;
+            out.n_desc.weak_ref = true;
         }
     }
 }
src/link/MachO/Thunk.zig
@@ -56,10 +56,10 @@ pub fn writeSymtab(thunk: Thunk, macho_file: *MachO, ctx: anytype) void {
         n_strx += @intCast("__thunk".len);
         ctx.strtab.items[n_strx] = 0;
         n_strx += 1;
-        out_sym.n_type = macho.N_SECT;
+        out_sym.n_type = .{ .bits = .{ .ext = false, .type = .sect, .pext = false, .is_stab = 0 } };
         out_sym.n_sect = @intCast(thunk.out_n_sect + 1);
         out_sym.n_value = @intCast(thunk.getTargetAddress(ref, macho_file));
-        out_sym.n_desc = 0;
+        out_sym.n_desc = @bitCast(@as(u16, 0));
     }
 }
 
src/link/MachO/ZigObject.zig
@@ -123,9 +123,9 @@ fn newSymbol(self: *ZigObject, allocator: Allocator, name: MachO.String, args: s
     self.symtab.set(nlist_idx, .{
         .nlist = .{
             .n_strx = name.pos,
-            .n_type = args.type,
+            .n_type = @bitCast(args.type),
             .n_sect = 0,
-            .n_desc = args.desc,
+            .n_desc = @bitCast(args.desc),
             .n_value = 0,
         },
         .size = 0,
@@ -206,8 +206,8 @@ pub fn resolveSymbols(self: *ZigObject, macho_file: *MachO) !void {
     const gpa = macho_file.base.comp.gpa;
 
     for (self.symtab.items(.nlist), self.symtab.items(.atom), self.globals.items, 0..) |nlist, atom_index, *global, i| {
-        if (!nlist.ext()) continue;
-        if (nlist.sect()) {
+        if (!nlist.n_type.bits.ext) continue;
+        if (nlist.n_type.bits.type == .sect) {
             const atom = self.getAtom(atom_index).?;
             if (!atom.isAlive()) continue;
         }
@@ -221,7 +221,7 @@ pub fn resolveSymbols(self: *ZigObject, macho_file: *MachO) !void {
         }
         global.* = gop.index;
 
-        if (nlist.undf() and !nlist.tentative()) continue;
+        if (nlist.n_type.bits.type == .undf and !nlist.tentative()) continue;
         if (gop.ref.getFile(macho_file) == null) {
             gop.ref.* = .{ .index = @intCast(i), .file = self.index };
             continue;
@@ -229,7 +229,7 @@ pub fn resolveSymbols(self: *ZigObject, macho_file: *MachO) !void {
 
         if (self.asFile().getSymbolRank(.{
             .archive = false,
-            .weak = nlist.weakDef(),
+            .weak = nlist.n_desc.weak_def_or_ref_to_weak,
             .tentative = nlist.tentative(),
         }) < gop.ref.getSymbol(macho_file).?.getSymbolRank(macho_file)) {
             gop.ref.* = .{ .index = @intCast(i), .file = self.index };
@@ -243,12 +243,12 @@ pub fn markLive(self: *ZigObject, macho_file: *MachO) void {
 
     for (0..self.symbols.items.len) |i| {
         const nlist = self.symtab.items(.nlist)[i];
-        if (!nlist.ext()) continue;
+        if (!nlist.n_type.bits.ext) continue;
 
         const ref = self.getSymbolRef(@intCast(i), macho_file);
         const file = ref.getFile(macho_file) orelse continue;
         const sym = ref.getSymbol(macho_file).?;
-        const should_keep = nlist.undf() or (nlist.tentative() and !sym.flags.tentative);
+        const should_keep = nlist.n_type.bits.type == .undf or (nlist.tentative() and !sym.flags.tentative);
         if (should_keep and file == .object and !file.object.alive) {
             file.object.alive = true;
             file.object.markLive(macho_file);
@@ -331,8 +331,8 @@ pub fn claimUnresolved(self: *ZigObject, macho_file: *MachO) void {
 
     for (self.symbols.items, 0..) |*sym, i| {
         const nlist = self.symtab.items(.nlist)[i];
-        if (!nlist.ext()) continue;
-        if (!nlist.undf()) continue;
+        if (!nlist.n_type.bits.ext) continue;
+        if (nlist.n_type.bits.type != .undf) continue;
 
         if (self.getSymbolRef(@intCast(i), macho_file).getFile(macho_file) != null) continue;
 
@@ -974,7 +974,7 @@ fn updateNavCode(
     atom.setAlive(true);
     atom.name = sym.name;
     nlist.n_strx = sym.name.pos;
-    nlist.n_type = macho.N_SECT;
+    nlist.n_type = .{ .bits = .{ .ext = false, .type = .sect, .pext = false, .is_stab = 0 } };
     nlist.n_sect = sect_index + 1;
     self.symtab.items(.size)[sym.nlist_idx] = code.len;
 
@@ -1115,7 +1115,7 @@ fn createTlvDescriptor(
     atom.name = sym.name;
     nlist.n_strx = sym.name.pos;
     nlist.n_sect = sect_index + 1;
-    nlist.n_type = macho.N_SECT;
+    nlist.n_type = .{ .bits = .{ .ext = false, .type = .sect, .pext = false, .is_stab = 0 } };
     nlist.n_value = 0;
     self.symtab.items(.size)[sym.nlist_idx] = size;
 
@@ -1322,7 +1322,7 @@ pub fn updateExports(
         const global_sym = &self.symbols.items[global_nlist_index];
         global_nlist.n_value = nlist.n_value;
         global_nlist.n_sect = nlist.n_sect;
-        global_nlist.n_type = macho.N_EXT | macho.N_SECT;
+        global_nlist.n_type = .{ .bits = .{ .ext = true, .type = .sect, .pext = false, .is_stab = 0 } };
         self.symtab.items(.size)[global_nlist_index] = self.symtab.items(.size)[nlist_idx];
         self.symtab.items(.atom)[global_nlist_index] = atom_index;
         global_sym.atom_ref = .{ .index = atom_index, .file = self.index };
@@ -1330,7 +1330,7 @@ pub fn updateExports(
         switch (exp.opts.linkage) {
             .internal => {
                 // Symbol should be hidden, or in MachO lingo, private extern.
-                global_nlist.n_type |= macho.N_PEXT;
+                global_nlist.n_type.bits.pext = true;
                 global_sym.visibility = .hidden;
             },
             .strong => {
@@ -1339,7 +1339,7 @@ pub fn updateExports(
             .weak => {
                 // Weak linkage is specified as part of n_desc field.
                 // Symbol's n_type is like for a symbol with strong linkage.
-                global_nlist.n_desc |= macho.N_WEAK_DEF;
+                global_nlist.n_desc.weak_def_or_ref_to_weak = true;
                 global_sym.visibility = .global;
                 global_sym.flags.weak = true;
             },
@@ -1394,7 +1394,7 @@ fn updateLazySymbol(
 
     const nlist = &self.symtab.items(.nlist)[sym.nlist_idx];
     nlist.n_strx = name_str.pos;
-    nlist.n_type = macho.N_SECT;
+    nlist.n_type = .{ .bits = .{ .ext = false, .type = .sect, .pext = false, .is_stab = 0 } };
     nlist.n_sect = output_section_index + 1;
     self.symtab.items(.size)[sym.nlist_idx] = code.len;
 
src/link/Dwarf.zig
@@ -4852,7 +4852,7 @@ fn flushWriterError(dwarf: *Dwarf, pt: Zcu.PerThread) (FlushError || Writer.Erro
                         hw.writeSleb128(dwarf.debug_frame.header.data_alignment_factor) catch unreachable;
                         hw.writeUleb128(dwarf.debug_frame.header.return_address_register) catch unreachable;
                         hw.writeUleb128(1) catch unreachable;
-                        hw.writeByte(DW.EH.PE.pcrel | DW.EH.PE.sdata4) catch unreachable;
+                        hw.writeByte(@bitCast(@as(DW.EH.PE, .{ .type = .sdata4, .rel = .pcrel }))) catch unreachable;
                         hw.writeByte(DW.CFA.def_cfa_sf) catch unreachable;
                         hw.writeUleb128(Register.rsp.dwarfNum()) catch unreachable;
                         hw.writeSleb128(-1) catch unreachable;
src/link/MachO.zig
@@ -4149,9 +4149,9 @@ pub const SymtabCtx = struct {
 
 pub const null_sym = macho.nlist_64{
     .n_strx = 0,
-    .n_type = 0,
+    .n_type = @bitCast(@as(u8, 0)),
     .n_sect = 0,
-    .n_desc = 0,
+    .n_desc = @bitCast(@as(u16, 0)),
     .n_value = 0,
 };