Sema: Diagnose invalid OS versions in if #available queries.

Part of rdar://155558161.

Author: tshortli

lib/Sema/MiscDiagnostics.cpp

@@ -5195,8 +5195,8 @@ static bool diagnoseAvailabilityCondition(PoundAvailableInfo *info,
       return true;
     }
 
+    auto rawVersion = parsedSpec->getRawVersion();
     if (hasVersion) {
-      auto rawVersion = parsedSpec->getRawVersion();
       if (!VersionRange::isValidVersion(rawVersion)) {
         diags
             .diagnose(loc, diag::availability_unsupported_version_number,
@@ -5211,6 +5211,12 @@ static bool diagnoseAvailabilityCondition(PoundAvailableInfo *info,
         diags.diagnose(loc, diag::avail_query_expected_version_number);
         return true;
       }
+
+      if (!domain.isVersionValid(rawVersion)) {
+        diags.diagnose(loc,
+                       diag::availability_invalid_version_number_for_domain,
+                       rawVersion, domain);
+      }
     } else if (hasVersion) {
       diags.diagnose(loc, diag::availability_unexpected_version, domain)
           .highlight(parsedSpec->getVersionSrcRange());

test/Availability/availability_versions_canonical.swift

@@ -94,6 +94,11 @@ func useUnderPoundAvailable() {
   }
 
   if #available(macOS 17.0, iOS 20.0, watchOS 13.0, tvOS 20.0, visionOS 4.0, *) {
+    // expected-warning@-1 {{'17.0' is not a valid version number for macOS}}
+    // expected-warning@-2 {{'20.0' is not a valid version number for iOS}}
+    // expected-warning@-3 {{'13.0' is not a valid version number for watchOS}}
+    // expected-warning@-4 {{'20.0' is not a valid version number for tvOS}}
+    // expected-warning@-5 {{'4.0' is not a valid version number for visionOS}}
     introducedInVersionsMappingTo27_0()
     introducedIn27_0()
   }