driver: remove unsecessary isOneof function

update `getPICMode` comment

src/aro/Driver.zig

@@ -25,6 +25,17 @@ pub const Linker = enum {
 
 const Driver = @This();
 
+const pic_related_options = StaticStringSet.initComptime(.{
+    .{"-fpic"},
+    .{"-fno-pic"},
+    .{"-fPIC"},
+    .{"-fno-PIC"},
+    .{"-fpie"},
+    .{"-fno-pie"},
+    .{"-fPIE"},
+    .{"-fno-PIE"},
+});
+
 comp: *Compilation,
 inputs: std.ArrayListUnmanaged(Source) = .{},
 link_objects: std.ArrayListUnmanaged([]const u8) = .{},
@@ -308,16 +319,6 @@ pub fn parseArgs(
                 d.comp.langopts.use_native_half_type = true;
             } else if (mem.eql(u8, arg, "-fnative-half-arguments-and-returns")) {
                 d.comp.langopts.allow_half_args_and_returns = true;
-            } else if (mem.eql(u8, arg, "-fno-pic") or mem.eql(u8, arg, "-fno-PIC") or mem.eql(u8, arg, "-fno-pie") or mem.eql(u8, arg, "-fno-PIE")) {
-                //
-            } else if (mem.eql(u8, arg, "-fpic")) {
-                //
-            } else if (mem.eql(u8, arg, "-fPIC")) {
-                //
-            } else if (mem.eql(u8, arg, "-fpie")) {
-                //
-            } else if (mem.eql(u8, arg, "-fPIE")) {
-                //
             } else if (mem.eql(u8, arg, "-fshort-enums")) {
                 d.comp.langopts.short_enums = true;
             } else if (mem.eql(u8, arg, "-fno-short-enums")) {
@@ -500,7 +501,8 @@ pub fn parseArgs(
                     try d.comp.addDiagnostic(.{ .tag = .invalid_unwindlib, .extra = .{ .str = unwindlib } }, &.{});
                 }
             } else {
-                try d.comp.addDiagnostic(.{ .tag = .cli_unknown_arg, .extra = .{ .str = arg } }, &.{});
+                if (!pic_related_options.has(arg))
+                    try d.comp.addDiagnostic(.{ .tag = .cli_unknown_arg, .extra = .{ .str = arg } }, &.{});
             }
         } else if (std.mem.endsWith(u8, arg, ".o") or std.mem.endsWith(u8, arg, ".obj")) {
             try d.link_objects.append(d.comp.gpa, arg);
@@ -898,7 +900,10 @@ fn exitWithCleanup(d: *Driver, code: u8) noreturn {
     std.process.exit(code);
 }
 
-/// This currently just returns the desired settings without considering target defaults / requirements
+/// Parses the various -fpic/-fPIC/-fpie/-fPIE arguments.
+/// Then, smooshes them together with platform defaults, to decide whether
+/// this compile should be using PIC mode or not.
+/// Returns a tuple of ( backend.CodeGenOptions.PicLevel, IsPIE).
 pub fn getPICMode(d: *Driver, args: []const []const u8) !struct { backend.CodeGenOptions.PicLevel, bool } {
     const eqlIgnoreCase = std.ascii.eqlIgnoreCase;
 
@@ -975,16 +980,7 @@ pub fn getPICMode(d: *Driver, args: []const []const u8) !struct { backend.CodeGe
     // other argument is used. If the last argument is any flavor of the
     // '-fno-...' arguments, both PIC and PIE are disabled. Any PIE
     // option implicitly enables PIC at the same level.
-    const lastpic_arg_idx = getLastArg(args, StaticStringSet.initComptime(.{
-        .{"-fpic"},
-        .{"-fno-pic"},
-        .{"-fPIC"},
-        .{"-fno-PIC"},
-        .{"-fpie"},
-        .{"-fno-pie"},
-        .{"-fPIE"},
-        .{"-fno-PIE"},
-    }));
+    const lastpic_arg_idx = getLastArg(args, pic_related_options);
     if (target.os.tag == .windows and
         !target_util.isCygwinMinGW(target) and
         lastpic_arg_idx != null and
@@ -1006,10 +1002,10 @@ pub fn getPICMode(d: *Driver, args: []const []const u8) !struct { backend.CodeGe
     if (!forced) {
         if (lastpic_arg_idx) |idx| {
             const arg = args[idx];
-            if (isOneOf(arg, StaticStringSet.initComptime(.{ .{"-fPIC"}, .{"-fpic"}, .{"-fpie"}, .{"-fPIE"} }))) {
-                pie = isOneOf(arg, StaticStringSet.initComptime(.{ .{"-fpie"}, .{"-fPIE"} }));
-                pic = pie or isOneOf(arg, StaticStringSet.initComptime(.{ .{"-fpic"}, .{"-fPIC"} }));
-                is_piclevel_two = isOneOf(arg, StaticStringSet.initComptime(.{ .{"-fPIE"}, .{"-fPIC"} }));
+            if (StaticStringSet.initComptime(.{ .{"-fPIC"}, .{"-fpic"}, .{"-fpie"}, .{"-fPIE"} }).has(arg)) {
+                pie = StaticStringSet.initComptime(.{ .{"-fpie"}, .{"-fPIE"} }).has(arg);
+                pic = pie or StaticStringSet.initComptime(.{ .{"-fpic"}, .{"-fPIC"} }).has(arg);
+                is_piclevel_two = StaticStringSet.initComptime(.{ .{"-fPIE"}, .{"-fPIC"} }).has(arg);
             } else {
                 pic, pie = .{ false, false };
                 if (target_util.isPS(target)) {
@@ -1125,7 +1121,3 @@ fn getLastArg(args: []const []const u8, options: StaticStringSet) ?usize {
     }
     return last_index;
 }
-
-fn isOneOf(arg: []const u8, options: StaticStringSet) bool {
-    return options.has(arg);
-}