macho: fix invalid default dylib link behavior

src/MachO/Options.zig

@@ -220,8 +220,8 @@ pub fn parse(arena: Allocator, args: []const []const u8, ctx: anytype) !Options
             search_strategy = .paths_first;
         } else if (mem.eql(u8, arg, "-search_dylib_first")) {
             search_strategy = .dylibs_first;
-        } else if (mem.eql(u8, arg, "-framework") or mem.eql(u8, arg, "-weak_framework")) {
-            try frameworks.put(it.nextOrFatal(ctx), .{});
+        } else if (mem.eql(u8, arg, "-framework")) {
+            try frameworks.put(it.nextOrFatal(ctx), .{ .needed = false });
         } else if (mem.startsWith(u8, arg, "-F")) {
             try framework_dirs.append(arg[2..]);
         } else if (mem.startsWith(u8, arg, "-needed-l")) {
@@ -231,11 +231,11 @@ pub fn parse(arena: Allocator, args: []const []const u8, ctx: anytype) !Options
         } else if (mem.eql(u8, arg, "-needed_framework")) {
             try frameworks.put(it.nextOrFatal(ctx), .{ .needed = true });
         } else if (mem.startsWith(u8, arg, "-weak-l")) {
-            try libs.put(arg["-weak-l".len..], .{ .weak = true });
+            try libs.put(arg["-weak-l".len..], .{ .needed = false, .weak = true });
         } else if (mem.eql(u8, arg, "-weak_library")) {
-            try libs.put(it.nextOrFatal(ctx), .{ .weak = true });
+            try libs.put(it.nextOrFatal(ctx), .{ .needed = false, .weak = true });
         } else if (mem.eql(u8, arg, "-weak_framework")) {
-            try frameworks.put(it.nextOrFatal(ctx), .{ .weak = true });
+            try frameworks.put(it.nextOrFatal(ctx), .{ .needed = false, .weak = true });
         } else if (mem.eql(u8, arg, "-o")) {
             out_path = it.nextOrFatal(ctx);
         } else if (mem.eql(u8, arg, "-stack_size")) {
@@ -403,7 +403,7 @@ pub fn parse(arena: Allocator, args: []const []const u8, ctx: anytype) !Options
         } else if (mem.eql(u8, arg, "-demangle")) {
             std.log.debug("TODO unimplemented -demangle option", .{});
         } else if (mem.startsWith(u8, arg, "-l")) {
-            try libs.put(arg[2..], .{});
+            try libs.put(arg[2..], .{ .needed = false });
         } else if (mem.startsWith(u8, arg, "-L")) {
             try lib_dirs.append(arg[2..]);
         } else if (mem.eql(u8, arg, "-no_deduplicate")) {

test/macho.zig

@@ -8,6 +8,10 @@ pub const cases = [_]Case{
         .build_root = "test/macho/dead-strip",
         .import = @import("macho/dead-strip/build.zig"),
     },
+    .{
+        .build_root = "test/macho/dead-strip-dylibs",
+        .import = @import("macho/dead-strip-dylibs/build.zig"),
+    },
     .{
         .build_root = "test/macho/dylib",
         .import = @import("macho/dylib/build.zig"),

test/macho/dead-strip-dylibs/build.zig

@@ -0,0 +1,54 @@
+const std = @import("std");
+
+pub fn build(b: *std.Build) void {
+    const test_step = b.step("test", "Test it");
+    b.default_step = test_step;
+
+    {
+        const exe = b.addSystemCommand(&.{
+            "cc",
+            "-fno-lto",
+            "main.c",
+            "-framework",
+            "Cocoa",
+            "-B../../../zig-out/bin/",
+            "-o",
+            "a1.out",
+        });
+        test_step.dependOn(&exe.step);
+
+        const check = std.Build.Step.CheckObject.create(b, .{ .path = b.pathFromRoot("a1.out") }, .macho);
+        check.checkStart("cmd LOAD_DYLIB");
+        check.checkNext("name {*}Cocoa");
+        check.checkStart("cmd LOAD_DYLIB");
+        check.checkNext("name {*}libobjc{*}.dylib");
+        check.step.dependOn(&exe.step);
+        test_step.dependOn(&check.step);
+
+        const run = b.addSystemCommand(&.{"./a1.out"});
+        run.has_side_effects = true;
+        run.step.dependOn(&exe.step);
+        test_step.dependOn(&run.step);
+    }
+
+    {
+        const exe = b.addSystemCommand(&.{
+            "cc",
+            "-fno-lto",
+            "main.c",
+            "-Wl,-dead_strip_dylibs",
+            "-framework",
+            "Cocoa",
+            "-B../../../zig-out/bin/",
+            "-o",
+            "a2.out",
+        });
+        test_step.dependOn(&exe.step);
+
+        const run = b.addSystemCommand(&.{"./a2.out"});
+        run.has_side_effects = true;
+        run.expectExitCode(@as(u8, @bitCast(@as(i8, -2))));
+        run.step.dependOn(&exe.step);
+        test_step.dependOn(&run.step);
+    }
+}

test/macho/dead-strip-dylibs/main.c

@@ -0,0 +1,11 @@
+#include <objc/runtime.h>
+
+int main(int argc, char* argv[]) {
+  if (objc_getClass("NSObject") == 0) {
+    return -1;
+  }
+  if (objc_getClass("NSApplication") == 0) {
+    return -2;
+  }
+  return 0;
+}

test/macho/dead-strip/build.zig

@@ -4,24 +4,24 @@ pub fn build(b: *std.Build) void {
     const test_step = b.step("test", "Test it");
     b.default_step = test_step;
 
-    const exe_step = b.addSystemCommand(&.{
+    const exe = b.addSystemCommand(&.{
         "cc",
         "-fno-lto",
         "-dead_strip",
         "main.c",
         "-B../../../zig-out/bin/",
     });
-    test_step.dependOn(&exe_step.step);
+    test_step.dependOn(&exe.step);
 
-    const run_step = b.addSystemCommand(&.{"./a.out"});
-    run_step.has_side_effects = true;
-    run_step.expectStdOutEqual("Hello!\n");
-    run_step.step.dependOn(&exe_step.step);
-    test_step.dependOn(&run_step.step);
+    const run = b.addSystemCommand(&.{"./a.out"});
+    run.has_side_effects = true;
+    run.expectStdOutEqual("Hello!\n");
+    run.step.dependOn(&exe.step);
+    test_step.dependOn(&run.step);
 
-    const check_step = std.Build.Step.CheckObject.create(b, .{ .path = b.pathFromRoot("a.out") }, .macho);
-    check_step.checkInSymtab();
-    check_step.checkNotPresent("{*} (__TEXT,__text) external _iAmUnused");
-    check_step.step.dependOn(&exe_step.step);
-    test_step.dependOn(&check_step.step);
+    const check = std.Build.Step.CheckObject.create(b, .{ .path = b.pathFromRoot("a.out") }, .macho);
+    check.checkInSymtab();
+    check.checkNotPresent("{*} (__TEXT,__text) external _iAmUnused");
+    check.step.dependOn(&exe.step);
+    test_step.dependOn(&check.step);
 }