chore(macos): remove code for dropped versions

src/platform/macos/permissions_manager.mm

@@ -10,17 +10,6 @@
 #include "src/logging.h"
 
 namespace platf {
-// Even though the following two functions are available starting in macOS 10.15, they weren't
-// actually in the Mac SDK until Xcode 12.2, the first to include the SDK for macOS 11
-#if __MAC_OS_X_VERSION_MAX_ALLOWED < 110000  // __MAC_11_0
-  // If they're not in the SDK then we can use our own function definitions.
-  // Need to use weak import so that this will link in macOS 10.14 and earlier
-  extern "C" bool
-  CGPreflightScreenCaptureAccess(void) __attribute__((weak_import));
-  extern "C" bool
-  CGRequestScreenCaptureAccess(void) __attribute__((weak_import));
-#endif
-
   namespace {
     auto
       screen_capture_allowed = std::atomic { false };
@@ -41,30 +30,12 @@
 
   bool
   PermissionsManager::request_screen_capture_permission() {
-    // This will generate a warning about CGPreflightScreenCaptureAccess and
-    // CGRequestScreenCaptureAccess being unavailable before macOS 10.15, but
-    // we have a guard to prevent it from being called on those earlier systems.
-    // Unfortunately the supported way to silence this warning, using @available,
-    // produces linker errors for __isPlatformVersionAtLeast, so we have to use
-    // a different method.
-    // We also ignore "tautological-pointer-compare" because when compiling with
-    // Xcode 12.2 and later, these functions are not weakly linked and will never
-    // be null, and therefore generate this warning. Since we are weakly linking
-    // when compiling with earlier Xcode versions, the check for null is
-    // necessary, and so we ignore the warning.
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wunguarded-availability-new"
-#pragma clang diagnostic ignored "-Wtautological-pointer-compare"
-    if ([[NSProcessInfo processInfo] isOperatingSystemAtLeastVersion:((NSOperatingSystemVersion) { 10, 15, 0 })] &&
-        // Double check that these weakly-linked symbols have been loaded:
-        CGPreflightScreenCaptureAccess != nullptr && CGRequestScreenCaptureAccess != nullptr &&
-        !CGPreflightScreenCaptureAccess()) {
+    if (!CGPreflightScreenCaptureAccess()) {
       BOOST_LOG(error) << "No screen capture permission!";
       BOOST_LOG(error) << "Please activate it in 'System Preferences' -> 'Privacy' -> 'Screen Recording'";
       CGRequestScreenCaptureAccess();
       return true;
     }
-#pragma clang diagnostic pop
     // Record that we determined that we have the screen capture permission.
     screen_capture_allowed = true;
     return false;