link/macho: fix perf bug in DWARF parsing

CMakeLists.txt

@@ -613,7 +613,6 @@ set(ZIG_STAGE2_SOURCES
     src/link/MachO/Atom.zig
     src/link/MachO/CodeSignature.zig
     src/link/MachO/DebugSymbols.zig
-    src/link/MachO/DwarfInfo.zig
     src/link/MachO/Dylib.zig
     src/link/MachO/InternalObject.zig
     src/link/MachO/Object.zig
@@ -625,6 +624,7 @@ set(ZIG_STAGE2_SOURCES
     src/link/MachO/dyld_info/Rebase.zig
     src/link/MachO/dyld_info/Trie.zig
     src/link/MachO/dyld_info/bind.zig
+    src/link/MachO/dwarf.zig
     src/link/MachO/eh_frame.zig
     src/link/MachO/fat.zig
     src/link/MachO/file.zig

lib/std/Build/Step/CheckObject.zig

@@ -1087,9 +1087,25 @@ const MachODumper = struct {
             try writer.writeAll(symtab_label ++ "\n");
 
             for (ctx.symtab.items) |sym| {
-                if (sym.stab()) continue;
                 const sym_name = ctx.getString(sym.n_strx);
-                if (sym.sect()) {
+                if (sym.stab()) {
+                    const tt = switch (sym.n_type) {
+                        macho.N_SO => "SO",
+                        macho.N_OSO => "OSO",
+                        macho.N_BNSYM => "BNSYM",
+                        macho.N_ENSYM => "ENSYM",
+                        macho.N_FUN => "FUN",
+                        macho.N_GSYM => "GSYM",
+                        macho.N_STSYM => "STSYM",
+                        else => "UNKNOWN STAB",
+                    };
+                    try writer.print("{x}", .{sym.n_value});
+                    if (sym.n_sect > 0) {
+                        const sect = ctx.sections.items[sym.n_sect - 1];
+                        try writer.print(" ({s},{s})", .{ sect.segName(), sect.sectName() });
+                    }
+                    try writer.print(" {s} (stab) {s}\n", .{ tt, sym_name });
+                } else if (sym.sect()) {
                     const sect = ctx.sections.items[sym.n_sect - 1];
                     try writer.print("{x} ({s},{s})", .{
                         sym.n_value,

src/link/MachO.zig

@@ -535,6 +535,7 @@ pub fn flushModule(self: *MachO, arena: Allocator, prog_node: *std.Progress.Node
 
     try self.addUndefinedGlobals();
     try self.resolveSymbols();
+    try self.parseDebugInfo();
     try self.resolveSyntheticSymbols();
 
     try self.convertTentativeDefinitions();
@@ -1409,6 +1410,12 @@ fn markLive(self: *MachO) void {
     }
 }
 
+pub fn parseDebugInfo(self: *MachO) !void {
+    for (self.objects.items) |index| {
+        try self.getFile(index).?.object.parseDebugInfo(self);
+    }
+}
+
 fn resolveSyntheticSymbols(self: *MachO) !void {
     const internal = self.getInternalObject() orelse return;
 
@@ -4840,7 +4847,6 @@ const Cache = std.Build.Cache;
 const CodeSignature = @import("MachO/CodeSignature.zig");
 const Compilation = @import("../Compilation.zig");
 pub const DebugSymbols = @import("MachO/DebugSymbols.zig");
-const DwarfInfo = @import("MachO/DwarfInfo.zig");
 const Dylib = @import("MachO/Dylib.zig");
 const ExportTrieSection = synthetic.ExportTrieSection;
 const File = @import("MachO/file.zig").File;