protoc: validate that reserved range start is before end (#13474)

This addresses #13442. This also backfills the tests to add tests for the two checks that were already implemented as well as one for the newly added check.

Finally, this fixes the location information so that positions for reserved ranges are correctly reported. (The previous check that already existed, for enums, failed to show line and column info.)

Closes #13474

COPYBARA_INTEGRATE_REVIEW=#13474 from jhump:jh/validate-msg-reserved-range-order 661adc7
PiperOrigin-RevId: 556979032

src/google/protobuf/compiler/parser.cc

@@ -661,9 +661,8 @@ bool Parser::Parse(io::Tokenizer* input, FileDescriptorProto* file) {
     root_location.RecordLegacyLocation(file,
                                        DescriptorPool::ErrorCollector::OTHER);
 
-    if (require_syntax_identifier_ || LookingAt("syntax")
-        || LookingAt("edition")
-    ) {
+    if (require_syntax_identifier_ || LookingAt("syntax") ||
+        LookingAt("edition")) {
       if (!ParseSyntaxIdentifier(file, root_location)) {
         // Don't attempt to parse the file if we didn't recognize the syntax
         // identifier.
@@ -1853,6 +1852,8 @@ bool Parser::ParseReservedNumbers(DescriptorProto* message,
     LocationRecorder location(parent_location, message->reserved_range_size());
 
     DescriptorProto::ReservedRange* range = message->add_reserved_range();
+    location.RecordLegacyLocation(range,
+                                  DescriptorPool::ErrorCollector::NUMBER);
     int start, end;
     io::Tokenizer::Token start_token;
     {
@@ -1959,6 +1960,8 @@ bool Parser::ParseReservedNumbers(EnumDescriptorProto* proto,
     LocationRecorder location(parent_location, proto->reserved_range_size());
 
     EnumDescriptorProto::EnumReservedRange* range = proto->add_reserved_range();
+    location.RecordLegacyLocation(range,
+                                  DescriptorPool::ErrorCollector::NUMBER);
     int start, end;
     io::Tokenizer::Token start_token;
     {

src/google/protobuf/compiler/parser_unittest.cc

@@ -2135,6 +2135,22 @@ TEST_F(ParserValidationErrorTest, ExtensionRangeNumberError) {
       "1:13: Suggested field numbers for Foo: 1\n");
 }
 
+TEST_F(ParserValidationErrorTest, ExtensionRangeNumberOrderError) {
+  ExpectHasValidationErrors(
+      "message Foo {\n"
+      "  extensions 2 to 1;\n"
+      "}\n",
+      "1:13: Extension range end number must be greater than start number.\n");
+}
+
+TEST_F(ParserValidationErrorTest, ReservedRangeError) {
+  ExpectHasValidationErrors(
+      "message Foo {\n"
+      "  reserved 2 to 1;\n"
+      "}\n",
+      "1:11: Reserved range end number must be greater than start number.\n");
+}
+
 TEST_F(ParserValidationErrorTest, Proto3ExtensionError) {
   ExpectHasValidationErrors(
       "syntax = 'proto3';\n"
@@ -2331,6 +2347,15 @@ TEST_F(ParserValidationErrorTest, EnumValueAliasError) {
       "definition. The next available enum value is 2.\n");
 }
 
+TEST_F(ParserValidationErrorTest, EnumReservedRangeError) {
+  ExpectHasValidationErrors(
+      "enum Foo {\n"
+      "  BAR = 1;\n"
+      "  reserved 2 to 1;\n"
+      "}\n",
+      "2:11: Reserved range end number must be greater than start number.\n");
+}
+
 TEST_F(ParserValidationErrorTest, ExplicitlyMapEntryError) {
   ExpectHasValidationErrors(
       "message Foo {\n"
@@ -3047,7 +3072,7 @@ class SourceInfoTest : public ParserTest {
       }
     }
 
-      return false;
+    return false;
   }
 
  private:
@@ -4240,7 +4265,6 @@ TEST_F(ParseEditionsTest, FeaturesWithoutEditions) {
 }
 
 
-
 }  // anonymous namespace
 
 }  // namespace compiler

src/google/protobuf/descriptor.cc

@@ -353,7 +353,7 @@ class FlatAllocation {
   template <typename U>
   bool Destroy() {
     if (std::is_trivially_destructible<U>::value) return true;
-    for (U* it = Begin<U>(), *end = End<U>(); it != end; ++it) {
+    for (U *it = Begin<U>(), *end = End<U>(); it != end; ++it) {
       it->~U();
     }
     return true;
@@ -6125,8 +6125,7 @@ void DescriptorBuilder::BuildMessage(const DescriptorProto& proto,
   result->reserved_names_ =
       alloc.AllocateArray<const std::string*>(reserved_name_count);
   for (int i = 0; i < reserved_name_count; ++i) {
-    result->reserved_names_[i] =
-        alloc.AllocateStrings(proto.reserved_name(i));
+    result->reserved_names_[i] = alloc.AllocateStrings(proto.reserved_name(i));
   }
 
   // Copy options.
@@ -6676,6 +6675,10 @@ void DescriptorBuilder::BuildReservedRange(
     AddError(parent->full_name(), proto, DescriptorPool::ErrorCollector::NUMBER,
              "Reserved numbers must be positive integers.");
   }
+  if (result->start >= result->end) {
+    AddError(parent->full_name(), proto, DescriptorPool::ErrorCollector::NUMBER,
+             "Reserved range end number must be greater than start number.");
+  }
 }
 
 void DescriptorBuilder::BuildReservedRange(
@@ -6824,8 +6827,7 @@ void DescriptorBuilder::BuildEnum(const EnumDescriptorProto& proto,
   result->reserved_names_ =
       alloc.AllocateArray<const std::string*>(reserved_name_count);
   for (int i = 0; i < reserved_name_count; ++i) {
-    result->reserved_names_[i] =
-        alloc.AllocateStrings(proto.reserved_name(i));
+    result->reserved_names_[i] = alloc.AllocateStrings(proto.reserved_name(i));
   }
 
   // Copy options.
@@ -7570,8 +7572,7 @@ void DescriptorBuilder::SuggestFieldNumbers(FileDescriptor* file,
     std::vector<Range> used_ordinals;
     auto add_ordinal = [&](int ordinal) {
       if (ordinal <= 0 || ordinal > FieldDescriptor::kMaxNumber) return;
-      if (!used_ordinals.empty() &&
-          ordinal == used_ordinals.back().to) {
+      if (!used_ordinals.empty() && ordinal == used_ordinals.back().to) {
         used_ordinals.back().to = ordinal + 1;
       } else {
         used_ordinals.push_back({ordinal, ordinal + 1});
@@ -8784,23 +8785,24 @@ bool DescriptorBuilder::OptionInterpreter::ExamineIfOptionIsSet(
 namespace {
 // Helpers for method below
 
-template <typename T> std::string ValueOutOfRange(
-    absl::string_view type_name, absl::string_view option_name) {
-  return absl::StrFormat(
-    "Value out of range, %d to %d, for %s option \"%s\".", \
-    std::numeric_limits<T>::min(), std::numeric_limits<T>::max(),
-    type_name, option_name);
+template <typename T>
+std::string ValueOutOfRange(absl::string_view type_name,
+                            absl::string_view option_name) {
+  return absl::StrFormat("Value out of range, %d to %d, for %s option \"%s\".",
+                         std::numeric_limits<T>::min(),
+                         std::numeric_limits<T>::max(), type_name, option_name);
 }
 
-template <typename T> std::string ValueMustBeInt(
-    absl::string_view type_name, absl::string_view option_name) {
+template <typename T>
+std::string ValueMustBeInt(absl::string_view type_name,
+                           absl::string_view option_name) {
   return absl::StrFormat(
-    "Value must be integer, from %d to %d, for %s option \"%s\".", \
-    std::numeric_limits<T>::min(), std::numeric_limits<T>::max(),
-    type_name, option_name);
+      "Value must be integer, from %d to %d, for %s option \"%s\".",
+      std::numeric_limits<T>::min(), std::numeric_limits<T>::max(), type_name,
+      option_name);
 }
 
-} // namespace
+}  // namespace
 
 bool DescriptorBuilder::OptionInterpreter::SetOptionValue(
     const FieldDescriptor* option_field, UnknownFieldSet* unknown_fields) {