Migrate MIME-type lookup to UTType (UniformTypeIdentifiers)

Replace the deprecated CoreServices UTI calls
(UTTypeCreatePreferredIdentifierForTag / UTTypeCopyPreferredTagWithClass)
in GCDWebServerGetMimeTypeForExtension with the modern
[UTType typeWithFilenameExtension:].preferredMIMEType, removing the
-Wdeprecated-declarations pragma. Behavior is unchanged: known
extensions map to the same MIME type, unknown ones fall back to the
default.

The UniformTypeIdentifiers framework (macOS 11+ / iOS 14+ / tvOS 14+,
within the project's deployment targets) is now linked in all three
build systems: Xcode (OTHER_LDFLAGS), CocoaPods (Core subspec
frameworks), and SwiftPM (linkedFramework).

Verified: Run-Tests.sh, swift build, and pod lib lint all pass.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

CLAUDE.md

@@ -44,7 +44,7 @@ This script was originally written for Xcode 11.3 and was updated for current Xc
 - The `webUploader` fixture test is **commented out**: this fork customized `GCDWebUploader` (delete/move/create disabled in commit `ef4b622`), so the recorded `Tests/WebUploader` fixtures no longer match. Re-record them or re-enable the line if those features are restored.
 - The **tvOS build step is commented out** because it requires the tvOS Simulator runtime to be installed (`xcodebuild -downloadPlatform tvOS`); without it the storyboard compile fails with "tvOS … Platform Not Installed". Re-enable once the runtime is present.
 
-Two project/source adjustments were also needed for the suite to build under current Xcode: the `Tests (Mac)` target sets `GENERATE_INFOPLIST_FILE = YES`, and the deprecated CoreServices UTI calls in `GCDWebServerFunctions.m` are wrapped in a `-Wdeprecated-declarations` pragma (the project builds Release with `-Werror`).
+A project adjustment was also needed for the suite to build under current Xcode: the `Tests (Mac)` target sets `GENERATE_INFOPLIST_FILE = YES`. MIME-type lookup in `GCDWebServerFunctions.m` uses the modern `UTType` API (UniformTypeIdentifiers), so that framework is linked in all three build systems (Xcode `OTHER_LDFLAGS`, the podspec Core subspec, and `Package.swift`).
 
 ### How the fixture-replay tests work
 

GCDWebServer.podspec

@@ -16,6 +16,7 @@ Pod::Spec.new do |s|
   s.subspec 'Core' do |cs|
     cs.source_files = 'GCDWebServer/**/*.{h,m}'
     cs.private_header_files = "GCDWebServer/Core/GCDWebServerPrivate.h"
+    cs.frameworks = 'UniformTypeIdentifiers'
     cs.ios.library = 'z'
     cs.ios.frameworks = 'CoreServices', 'CFNetwork'
     cs.tvos.library = 'z'

GCDWebServer.xcodeproj/project.pbxproj

@@ -1169,6 +1169,7 @@
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
 				BUNDLE_VERSION_STRING = 3.5.4;
+				OTHER_LDFLAGS = "-framework UniformTypeIdentifiers";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BLOCK_CAPTURE_AUTORELEASING = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
@@ -1239,6 +1240,7 @@
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
 				BUNDLE_VERSION_STRING = 3.5.4;
+				OTHER_LDFLAGS = "-framework UniformTypeIdentifiers";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BLOCK_CAPTURE_AUTORELEASING = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;

GCDWebServer/Core/GCDWebServerFunctions.m

@@ -35,6 +35,7 @@
 #else
 #import <SystemConfiguration/SystemConfiguration.h>
 #endif
+#import <UniformTypeIdentifiers/UniformTypeIdentifiers.h>
 #import <CommonCrypto/CommonDigest.h>
 
 #import <ifaddrs.h>
@@ -176,17 +177,7 @@ NSString* GCDWebServerGetMimeTypeForExtension(NSString* extension, NSDictionary<
       mimeType = [builtInOverrides objectForKey:extension];
     }
     if (mimeType == nil) {
-      // These CoreServices UTI functions are deprecated since macOS 12 / iOS 15 in favor of the
+      mimeType = [UTType typeWithFilenameExtension:extension].preferredMIMEType;
-      // UniformTypeIdentifiers UTType class, but they still work and avoid pulling in a new framework
-      // dependency across the Xcode/CocoaPods/SPM builds. Silence the deprecation under -Werror.
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wdeprecated-declarations"
-      CFStringRef uti = UTTypeCreatePreferredIdentifierForTag(kUTTagClassFilenameExtension, (__bridge CFStringRef)extension, NULL);
-      if (uti) {
-        mimeType = CFBridgingRelease(UTTypeCopyPreferredTagWithClass(uti, kUTTagClassMIMEType));
-        CFRelease(uti);
-      }
-#pragma clang diagnostic pop
     }
   }
   return mimeType ? mimeType : kGCDWebServerDefaultMimeType;

Package.swift

@@ -27,6 +27,7 @@ let package = Package(
       ],
       linkerSettings: [
         .linkedLibrary("z"),
+        .linkedFramework("UniformTypeIdentifiers"),
         .linkedFramework("CoreServices", .when(platforms: [.iOS, .tvOS])),
         .linkedFramework("CFNetwork", .when(platforms: [.iOS, .tvOS])),
         .linkedFramework("SystemConfiguration", .when(platforms: [.macOS])),