Enforce bound checking in some functions in FieldDescriptor.

This enum value is user provided and they might have bugs.

PiperOrigin-RevId: 952911412

Author: sbenzaquen

src/google/protobuf/descriptor.cc

@@ -690,6 +690,21 @@ Descriptor::WellKnownType FindWellKnownType(absl::string_view name) {
 
 }  // namespace
 
+FieldDescriptor::CppType FieldDescriptor::TypeToCppType(Type type) {
+  ABSL_CHECK(type > 0 && type <= MAX_TYPE) << "Invalid input value.";
+  return kTypeToCppTypeMap[type];
+}
+
+absl::string_view FieldDescriptor::TypeName(Type type) {
+  ABSL_CHECK(type > 0 && type <= MAX_TYPE) << "Invalid input value.";
+  return kTypeToName[type];
+}
+
+absl::string_view FieldDescriptor::CppTypeName(CppType cpp_type) {
+  ABSL_CHECK(cpp_type > 0 && cpp_type <= MAX_CPPTYPE) << "Invalid input value.";
+  return kCppTypeToName[cpp_type];
+}
+
 const FieldDescriptor::CppType
     FieldDescriptor::kTypeToCppTypeMap[MAX_TYPE + 1] = {
         static_cast<CppType>(0),  // 0 is reserved for errors

src/google/protobuf/descriptor.h

@@ -3212,18 +3212,6 @@ inline absl::string_view FieldDescriptor::cpp_type_name() const {
   return kCppTypeToName[kTypeToCppTypeMap[type()]];
 }
 
-inline FieldDescriptor::CppType FieldDescriptor::TypeToCppType(Type type) {
-  return kTypeToCppTypeMap[type];
-}
-
-inline absl::string_view FieldDescriptor::TypeName(Type type) {
-  return kTypeToName[type];
-}
-
-inline absl::string_view FieldDescriptor::CppTypeName(CppType cpp_type) {
-  return kCppTypeToName[cpp_type];
-}
-
 inline bool FieldDescriptor::IsTypePackable(Type field_type) {
   return (field_type != FieldDescriptor::TYPE_STRING &&
           field_type != FieldDescriptor::TYPE_GROUP &&

src/google/protobuf/descriptor_unittest.cc

@@ -3177,6 +3177,9 @@ TEST_F(MiscTest, StaticTypeNames) {
   EXPECT_EQ(absl::string_view("sfixed64"), FD::TypeName(FD::TYPE_SFIXED64));
   EXPECT_EQ(absl::string_view("sint32"), FD::TypeName(FD::TYPE_SINT32));
   EXPECT_EQ(absl::string_view("sint64"), FD::TypeName(FD::TYPE_SINT64));
+
+  EXPECT_DEATH(FD::TypeName(static_cast<FD::Type>(FD::MAX_TYPE + 1)),
+               "Invalid input value");
 }
 
 TEST_F(MiscTest, CppTypes) {
@@ -3262,6 +3265,35 @@ TEST_F(MiscTest, StaticCppTypeNames) {
   EXPECT_EQ(absl::string_view("enum"), FD::CppTypeName(FD::CPPTYPE_ENUM));
   EXPECT_EQ(absl::string_view("string"), FD::CppTypeName(FD::CPPTYPE_STRING));
   EXPECT_EQ(absl::string_view("message"), FD::CppTypeName(FD::CPPTYPE_MESSAGE));
+
+  EXPECT_DEATH(FD::CppTypeName(static_cast<FD::CppType>(FD::MAX_CPPTYPE + 1)),
+               "Invalid input value");
+}
+
+TEST_F(MiscTest, StaticTypeToCppType) {
+  typedef FieldDescriptor FD;  // avoid ugly line wrapping
+                               //
+  EXPECT_EQ(FD::CPPTYPE_DOUBLE, FD::TypeToCppType(FD::TYPE_DOUBLE));
+  EXPECT_EQ(FD::CPPTYPE_FLOAT, FD::TypeToCppType(FD::TYPE_FLOAT));
+  EXPECT_EQ(FD::CPPTYPE_INT64, FD::TypeToCppType(FD::TYPE_INT64));
+  EXPECT_EQ(FD::CPPTYPE_UINT64, FD::TypeToCppType(FD::TYPE_UINT64));
+  EXPECT_EQ(FD::CPPTYPE_INT32, FD::TypeToCppType(FD::TYPE_INT32));
+  EXPECT_EQ(FD::CPPTYPE_UINT64, FD::TypeToCppType(FD::TYPE_FIXED64));
+  EXPECT_EQ(FD::CPPTYPE_UINT32, FD::TypeToCppType(FD::TYPE_FIXED32));
+  EXPECT_EQ(FD::CPPTYPE_BOOL, FD::TypeToCppType(FD::TYPE_BOOL));
+  EXPECT_EQ(FD::CPPTYPE_STRING, FD::TypeToCppType(FD::TYPE_STRING));
+  EXPECT_EQ(FD::CPPTYPE_MESSAGE, FD::TypeToCppType(FD::TYPE_GROUP));
+  EXPECT_EQ(FD::CPPTYPE_MESSAGE, FD::TypeToCppType(FD::TYPE_MESSAGE));
+  EXPECT_EQ(FD::CPPTYPE_STRING, FD::TypeToCppType(FD::TYPE_BYTES));
+  EXPECT_EQ(FD::CPPTYPE_UINT32, FD::TypeToCppType(FD::TYPE_UINT32));
+  EXPECT_EQ(FD::CPPTYPE_ENUM, FD::TypeToCppType(FD::TYPE_ENUM));
+  EXPECT_EQ(FD::CPPTYPE_INT32, FD::TypeToCppType(FD::TYPE_SFIXED32));
+  EXPECT_EQ(FD::CPPTYPE_INT64, FD::TypeToCppType(FD::TYPE_SFIXED64));
+  EXPECT_EQ(FD::CPPTYPE_INT32, FD::TypeToCppType(FD::TYPE_SINT32));
+  EXPECT_EQ(FD::CPPTYPE_INT64, FD::TypeToCppType(FD::TYPE_SINT64));
+
+  EXPECT_DEATH(FD::TypeToCppType(static_cast<FD::Type>(FD::MAX_TYPE + 1)),
+               "Invalid input value");
 }
 
 TEST_F(MiscTest, MessageType) {