Merge pull request swiftlang#71953 from tshortli/safe-platform-kind-deserialization

Serialization: Error when decoding invalid PlatformKind values

Author: tshortli

include/swift/AST/PlatformKind.h

@@ -42,6 +42,10 @@ StringRef platformString(PlatformKind platform);
 /// or None if such a platform kind does not exist.
 std::optional<PlatformKind> platformFromString(StringRef Name);
 
+/// Safely converts the given unsigned value to a valid \c PlatformKind value or
+/// \c nullopt otherwise.
+std::optional<PlatformKind> platformFromUnsigned(unsigned value);
+
 /// Returns a valid platform string that is closest to the candidate string
 /// based on edit distance. Returns \c None if the closest valid platform
 /// distance is not within a minimum threshold.

lib/AST/PlatformKind.cpp

@@ -58,6 +58,17 @@ std::optional<PlatformKind> swift::platformFromString(StringRef Name) {
       .Default(std::optional<PlatformKind>());
 }
 
+std::optional<PlatformKind> swift::platformFromUnsigned(unsigned value) {
+  PlatformKind platform = PlatformKind(value);
+  switch (platform) {
+  case PlatformKind::none:
+#define AVAILABILITY_PLATFORM(X, PrettyName) case PlatformKind::X:
+#include "swift/AST/PlatformKinds.def"
+    return platform;
+  }
+  return std::nullopt;
+}
+
 std::optional<StringRef>
 swift::closestCorrectedPlatformString(StringRef candidate) {
   auto lowerCasedCandidate = candidate.lower();

lib/Serialization/Deserialization.cpp

@@ -163,6 +163,8 @@ const char UnsafeDeserializationError::ID = '\0';
 void UnsafeDeserializationError::anchor() {}
 const char ModularizationError::ID = '\0';
 void ModularizationError::anchor() {}
+const char InvalidEnumValueError::ID = '\0';
+void InvalidEnumValueError::anchor() {}
 
 /// Skips a single record in the bitstream.
 ///
@@ -5295,8 +5297,9 @@ class DeclDeserializer {
     return macro;
   }
 
-  AvailableAttr *readAvailable_DECL_ATTR(SmallVectorImpl<uint64_t> &scratch,
-                                         StringRef blobData);
+  Expected<AvailableAttr *>
+  readAvailable_DECL_ATTR(SmallVectorImpl<uint64_t> &scratch,
+                          StringRef blobData);
 };
 }
 
@@ -5349,7 +5352,7 @@ ModuleFile::getDeclChecked(
   return declOrOffset;
 }
 
-AvailableAttr *
+Expected<AvailableAttr *>
 DeclDeserializer::readAvailable_DECL_ATTR(SmallVectorImpl<uint64_t> &scratch,
                                           StringRef blobData) {
   bool isImplicit;
@@ -5362,14 +5365,21 @@ DeclDeserializer::readAvailable_DECL_ATTR(SmallVectorImpl<uint64_t> &scratch,
   DEF_VER_TUPLE_PIECES(Deprecated);
   DEF_VER_TUPLE_PIECES(Obsoleted);
   DeclID renameDeclID;
-  unsigned platform, messageSize, renameSize;
+  unsigned rawPlatform, messageSize, renameSize;
 
   // Decode the record, pulling the version tuple information.
   serialization::decls_block::AvailableDeclAttrLayout::readRecord(
       scratch, isImplicit, isUnavailable, isDeprecated, isNoAsync,
-      isPackageDescriptionVersionSpecific, isSPI, LIST_VER_TUPLE_PIECES(Introduced),
-      LIST_VER_TUPLE_PIECES(Deprecated), LIST_VER_TUPLE_PIECES(Obsoleted),
-      platform, renameDeclID, messageSize, renameSize);
+      isPackageDescriptionVersionSpecific, isSPI,
+      LIST_VER_TUPLE_PIECES(Introduced), LIST_VER_TUPLE_PIECES(Deprecated),
+      LIST_VER_TUPLE_PIECES(Obsoleted), rawPlatform, renameDeclID, messageSize,
+      renameSize);
+
+  auto maybePlatform = platformFromUnsigned(rawPlatform);
+  if (!maybePlatform.has_value())
+    return llvm::make_error<InvalidEnumValueError>(rawPlatform, "PlatformKind");
+
+  PlatformKind platform = maybePlatform.value();
 
   ValueDecl *renameDecl = nullptr;
   if (renameDeclID) {
@@ -5391,7 +5401,7 @@ DeclDeserializer::readAvailable_DECL_ATTR(SmallVectorImpl<uint64_t> &scratch,
     platformAgnostic = PlatformAgnosticAvailabilityKind::Deprecated;
   else if (isNoAsync)
     platformAgnostic = PlatformAgnosticAvailabilityKind::NoAsync;
-  else if (((PlatformKind)platform) == PlatformKind::none &&
+  else if (platform == PlatformKind::none &&
            (!Introduced.empty() || !Deprecated.empty() || !Obsoleted.empty()))
     platformAgnostic =
         isPackageDescriptionVersionSpecific
@@ -5402,9 +5412,9 @@ DeclDeserializer::readAvailable_DECL_ATTR(SmallVectorImpl<uint64_t> &scratch,
     platformAgnostic = PlatformAgnosticAvailabilityKind::None;
 
   auto attr = new (ctx) AvailableAttr(
-      SourceLoc(), SourceRange(), (PlatformKind)platform, message, rename,
-      renameDecl, Introduced, SourceRange(), Deprecated, SourceRange(),
-      Obsoleted, SourceRange(), platformAgnostic, isImplicit, isSPI);
+      SourceLoc(), SourceRange(), platform, message, rename, renameDecl,
+      Introduced, SourceRange(), Deprecated, SourceRange(), Obsoleted,
+      SourceRange(), platformAgnostic, isImplicit, isSPI);
   return attr;
 }
 
@@ -5643,7 +5653,11 @@ llvm::Error DeclDeserializer::deserializeDeclCommon() {
       }
 
       case decls_block::Available_DECL_ATTR: {
-        Attr = readAvailable_DECL_ATTR(scratch, blobData);
+        auto attrOrError = readAvailable_DECL_ATTR(scratch, blobData);
+        if (!attrOrError)
+          return MF.diagnoseFatal(attrOrError.takeError());
+
+        Attr = attrOrError.get();
         break;
       }
 
@@ -5753,7 +5767,10 @@ llvm::Error DeclDeserializer::deserializeDeclCommon() {
           }
 
           auto attr = readAvailable_DECL_ATTR(scratch, blobData);
-          availabilityAttrs.push_back(attr);
+          if (!attr)
+            return MF.diagnoseFatal(attr.takeError());
+
+          availabilityAttrs.push_back(attr.get());
           restoreOffset2.cancel();
           --numAvailabilityAttrs;
         }

lib/Serialization/DeserializationErrors.h

@@ -646,6 +646,32 @@ class UnsafeDeserializationError : public llvm::ErrorInfo<UnsafeDeserializationE
   }
 };
 
+class InvalidEnumValueError
+    : public llvm::ErrorInfo<InvalidEnumValueError, DeclDeserializationError> {
+  friend ErrorInfo;
+  static const char ID;
+  void anchor() override;
+
+  unsigned enumValue;
+  const char *enumDescription;
+
+public:
+  explicit InvalidEnumValueError(unsigned enumValue,
+                                 const char *enumDescription) {
+    this->enumValue = enumValue;
+    this->enumDescription = enumDescription;
+  }
+
+  void log(raw_ostream &OS) const override {
+    OS << "invalid value " << enumValue << " for enumeration "
+       << enumDescription;
+  }
+
+  std::error_code convertToErrorCode() const override {
+    return llvm::inconvertibleErrorCode();
+  }
+};
+
 class PrettyStackTraceModuleFile : public llvm::PrettyStackTraceEntry {
   const char *Action;
   const ModuleFile &MF;