diff --git a/include/swift/ABI/Task.h b/include/swift/ABI/Task.h
index d624dc0ba3004..5bbd120551ec5 100644
--- a/include/swift/ABI/Task.h
+++ b/include/swift/ABI/Task.h
@@ -736,9 +736,12 @@ static_assert(sizeof(AsyncTask) == NumWords_AsyncTask * sizeof(void*),
               "AsyncTask size is wrong");
 static_assert(alignof(AsyncTask) == 2 * alignof(void*),
               "AsyncTask alignment is wrong");
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Winvalid-offsetof"
 // Libc hardcodes this offset to extract the TaskID
 static_assert(offsetof(AsyncTask, Id) == 4 * sizeof(void *) + 4,
               "AsyncTask::Id offset is wrong");
+#pragma clang diagnostic pop
 
 SWIFT_CC(swiftasync)
 inline void Job::runInFullyEstablishedContext() {
diff --git a/include/swift/Remote/MetadataReader.h b/include/swift/Remote/MetadataReader.h
index 990648697286c..5c583d5ec1150 100644
--- a/include/swift/Remote/MetadataReader.h
+++ b/include/swift/Remote/MetadataReader.h
@@ -1481,7 +1481,7 @@ class MetadataReader {
       return 0;
     };
 
-    switch (auto kind = flags.getKind()) {
+    switch (flags.getKind()) {
     case ContextDescriptorKind::Module:
       baseSize = sizeof(TargetModuleContextDescriptor<Runtime>);
       break;
diff --git a/lib/Demangling/Demangler.cpp b/lib/Demangling/Demangler.cpp
index 6cd04157b500e..e77345d9e9897 100644
--- a/lib/Demangling/Demangler.cpp
+++ b/lib/Demangling/Demangler.cpp
@@ -2810,7 +2810,7 @@ NodePointer Demangler::demangleThunkOrSpecialization() {
   switch (char c = nextChar()) {
     // Thunks that are from a thunk inst. We take the TT namespace.
     case 'T': {
-      switch (char c = nextChar()) {
+      switch (nextChar()) {
       case 'I':
         return createWithChild(Node::Kind::SILThunkIdentity, popNode(isEntity));
       case 'H':
diff --git a/stdlib/public/Concurrency/TaskPrivate.h b/stdlib/public/Concurrency/TaskPrivate.h
index 82436a28cd7ab..361af35590ca3 100644
--- a/stdlib/public/Concurrency/TaskPrivate.h
+++ b/stdlib/public/Concurrency/TaskPrivate.h
@@ -865,8 +865,11 @@ struct AsyncTask::PrivateStorage {
 
 // It will be aligned to 2 words on all platforms. On arm64_32, we have an
 // additional requirement where it is aligned to 4 words.
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Winvalid-offsetof"
 static_assert(((offsetof(AsyncTask, Private) + offsetof(AsyncTask::PrivateStorage, StatusStorage)) % ACTIVE_TASK_STATUS_SIZE == 0),
    "StatusStorage is not aligned in the AsyncTask");
+#pragma clang diagnostic pop
 static_assert(sizeof(AsyncTask::PrivateStorage) <= sizeof(AsyncTask::OpaquePrivateStorage),
               "Task-private storage doesn't fit in reserved space");
 
diff --git a/stdlib/public/runtime/LibPrespecialized.cpp b/stdlib/public/runtime/LibPrespecialized.cpp
index 2d62bb7be7d5d..6303a7a80d3e1 100644
--- a/stdlib/public/runtime/LibPrespecialized.cpp
+++ b/stdlib/public/runtime/LibPrespecialized.cpp
@@ -686,7 +686,7 @@ void _swift_validatePrespecializedMetadata() {
 
     auto result = swift_getTypeByMangledName(MetadataState::Complete,
                                              mangledName, nullptr, {}, {});
-    if (auto *error = result.getError()) {
+    if (result.getError()) {
       fprintf(stderr,
               "Prespecializations library validation: unable to build metadata "
               "for mangled name '%s'\n",
diff --git a/stdlib/public/runtime/MetadataLookup.cpp b/stdlib/public/runtime/MetadataLookup.cpp
index 86149b66ab53c..ccb49f71e55b9 100644
--- a/stdlib/public/runtime/MetadataLookup.cpp
+++ b/stdlib/public/runtime/MetadataLookup.cpp
@@ -164,7 +164,7 @@ ResolveAsSymbolicReference::operator()(SymbolicReferenceKind kind,
       break;
         
     default:
-      if (auto typeContext = dyn_cast<TypeContextDescriptor>(descriptor)) {
+      if (isa<TypeContextDescriptor>(descriptor)) {
         nodeKind = Node::Kind::TypeSymbolicReference;
         isType = true;
         break;
diff --git a/stdlib/toolchain/Compatibility56/include/Concurrency/Task.h b/stdlib/toolchain/Compatibility56/include/Concurrency/Task.h
index 33a27c6ddda12..a812e97301484 100644
--- a/stdlib/toolchain/Compatibility56/include/Concurrency/Task.h
+++ b/stdlib/toolchain/Compatibility56/include/Concurrency/Task.h
@@ -605,9 +605,12 @@ static_assert(sizeof(AsyncTask) == NumWords_AsyncTask * sizeof(void*),
               "AsyncTask size is wrong");
 static_assert(alignof(AsyncTask) == 2 * alignof(void*),
               "AsyncTask alignment is wrong");
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Winvalid-offsetof"
 // Libc hardcodes this offset to extract the TaskID
 static_assert(offsetof(AsyncTask, Id) == 4 * sizeof(void *) + 4,
               "AsyncTask::Id offset is wrong");
+#pragma clang diagnostic pop
 
 SWIFT_CC(swiftasync)
 inline void Job::runInFullyEstablishedContext() {