Fix handling non null-terminated string_views in LookupByKey (#8203)
* Reproduce the error in a unit test
Reproduces #8200
* Overload KeyCompareWithValue to work for string-like objects
This fixes #8200.
* Extra tests
---------
Co-authored-by: Derek Bailey <derekbailey@google.com>
diff --git a/include/flatbuffers/reflection_generated.h b/include/flatbuffers/reflection_generated.h
index 79e15a5..9035128 100644
--- a/include/flatbuffers/reflection_generated.h
+++ b/include/flatbuffers/reflection_generated.h
@@ -274,6 +274,12 @@
int KeyCompareWithValue(const char *_key) const {
return strcmp(key()->c_str(), _key);
}
+ template<typename StringType>
+ int KeyCompareWithValue(const StringType& _key) const {
+ if (key()->c_str() < _key) return -1;
+ if (_key < key()->c_str()) return 1;
+ return 0;
+ }
const ::flatbuffers::String *value() const {
return GetPointer<const ::flatbuffers::String *>(VT_VALUE);
}
@@ -464,6 +470,12 @@
int KeyCompareWithValue(const char *_name) const {
return strcmp(name()->c_str(), _name);
}
+ template<typename StringType>
+ int KeyCompareWithValue(const StringType& _name) const {
+ if (name()->c_str() < _name) return -1;
+ if (_name < name()->c_str()) return 1;
+ return 0;
+ }
const ::flatbuffers::Vector<::flatbuffers::Offset<reflection::EnumVal>> *values() const {
return GetPointer<const ::flatbuffers::Vector<::flatbuffers::Offset<reflection::EnumVal>> *>(VT_VALUES);
}
@@ -616,6 +628,12 @@
int KeyCompareWithValue(const char *_name) const {
return strcmp(name()->c_str(), _name);
}
+ template<typename StringType>
+ int KeyCompareWithValue(const StringType& _name) const {
+ if (name()->c_str() < _name) return -1;
+ if (_name < name()->c_str()) return 1;
+ return 0;
+ }
const reflection::Type *type() const {
return GetPointer<const reflection::Type *>(VT_TYPE);
}
@@ -834,6 +852,12 @@
int KeyCompareWithValue(const char *_name) const {
return strcmp(name()->c_str(), _name);
}
+ template<typename StringType>
+ int KeyCompareWithValue(const StringType& _name) const {
+ if (name()->c_str() < _name) return -1;
+ if (_name < name()->c_str()) return 1;
+ return 0;
+ }
const ::flatbuffers::Vector<::flatbuffers::Offset<reflection::Field>> *fields() const {
return GetPointer<const ::flatbuffers::Vector<::flatbuffers::Offset<reflection::Field>> *>(VT_FIELDS);
}
@@ -986,6 +1010,12 @@
int KeyCompareWithValue(const char *_name) const {
return strcmp(name()->c_str(), _name);
}
+ template<typename StringType>
+ int KeyCompareWithValue(const StringType& _name) const {
+ if (name()->c_str() < _name) return -1;
+ if (_name < name()->c_str()) return 1;
+ return 0;
+ }
const reflection::Object *request() const {
return GetPointer<const reflection::Object *>(VT_REQUEST);
}
@@ -1102,6 +1132,12 @@
int KeyCompareWithValue(const char *_name) const {
return strcmp(name()->c_str(), _name);
}
+ template<typename StringType>
+ int KeyCompareWithValue(const StringType& _name) const {
+ if (name()->c_str() < _name) return -1;
+ if (_name < name()->c_str()) return 1;
+ return 0;
+ }
const ::flatbuffers::Vector<::flatbuffers::Offset<reflection::RPCCall>> *calls() const {
return GetPointer<const ::flatbuffers::Vector<::flatbuffers::Offset<reflection::RPCCall>> *>(VT_CALLS);
}
@@ -1221,6 +1257,12 @@
int KeyCompareWithValue(const char *_filename) const {
return strcmp(filename()->c_str(), _filename);
}
+ template<typename StringType>
+ int KeyCompareWithValue(const StringType& _filename) const {
+ if (filename()->c_str() < _filename) return -1;
+ if (_filename < filename()->c_str()) return 1;
+ return 0;
+ }
/// Names of included files, relative to project root.
const ::flatbuffers::Vector<::flatbuffers::Offset<::flatbuffers::String>> *included_filenames() const {
return GetPointer<const ::flatbuffers::Vector<::flatbuffers::Offset<::flatbuffers::String>> *>(VT_INCLUDED_FILENAMES);
diff --git a/src/idl_gen_cpp.cpp b/src/idl_gen_cpp.cpp
index 621ea19..301c08d 100644
--- a/src/idl_gen_cpp.cpp
+++ b/src/idl_gen_cpp.cpp
@@ -2417,8 +2417,20 @@
// Generate KeyCompareWithValue function
if (is_string) {
+ // Compares key against a null-terminated char array.
code_ += " int KeyCompareWithValue(const char *_{{FIELD_NAME}}) const {";
code_ += " return strcmp({{FIELD_NAME}}()->c_str(), _{{FIELD_NAME}});";
+ code_ += " }";
+ // Compares key against any string-like object (e.g. std::string_view or
+ // std::string) that implements operator< comparison with const char*.
+ code_ += " template<typename StringType>";
+ code_ +=
+ " int KeyCompareWithValue(const StringType& _{{FIELD_NAME}}) const "
+ "{";
+ code_ +=
+ " if ({{FIELD_NAME}}()->c_str() < _{{FIELD_NAME}}) return -1;";
+ code_ += " if (_{{FIELD_NAME}} < {{FIELD_NAME}}()->c_str()) return 1;";
+ code_ += " return 0;";
} else if (is_array) {
const auto &elem_type = field.value.type.VectorType();
std::string input_type = "::flatbuffers::Array<" +
diff --git a/tests/cpp17/generated_cpp17/monster_test_generated.h b/tests/cpp17/generated_cpp17/monster_test_generated.h
index be3371b..acbfb97 100644
--- a/tests/cpp17/generated_cpp17/monster_test_generated.h
+++ b/tests/cpp17/generated_cpp17/monster_test_generated.h
@@ -1436,6 +1436,12 @@
int KeyCompareWithValue(const char *_name) const {
return strcmp(name()->c_str(), _name);
}
+ template<typename StringType>
+ int KeyCompareWithValue(const StringType& _name) const {
+ if (name()->c_str() < _name) return -1;
+ if (_name < name()->c_str()) return 1;
+ return 0;
+ }
const ::flatbuffers::Vector<uint8_t> *inventory() const {
return GetPointer<const ::flatbuffers::Vector<uint8_t> *>(VT_INVENTORY);
}
diff --git a/tests/key_field/key_field_sample_generated.h b/tests/key_field/key_field_sample_generated.h
index ea8e041..b98eaeb 100644
--- a/tests/key_field/key_field_sample_generated.h
+++ b/tests/key_field/key_field_sample_generated.h
@@ -598,6 +598,12 @@
int KeyCompareWithValue(const char *_c) const {
return strcmp(c()->c_str(), _c);
}
+ template<typename StringType>
+ int KeyCompareWithValue(const StringType& _c) const {
+ if (c()->c_str() < _c) return -1;
+ if (_c < c()->c_str()) return 1;
+ return 0;
+ }
const ::flatbuffers::Vector<const keyfield::sample::Baz *> *d() const {
return GetPointer<const ::flatbuffers::Vector<const keyfield::sample::Baz *> *>(VT_D);
}
diff --git a/tests/monster_test.cpp b/tests/monster_test.cpp
index 8ec031a..b546d20 100644
--- a/tests/monster_test.cpp
+++ b/tests/monster_test.cpp
@@ -313,6 +313,33 @@
TEST_NOTNULL(vecoftables->LookupByKey("Fred"));
TEST_NOTNULL(vecoftables->LookupByKey("Wilma"));
+ // Verify the same objects are returned for char*-based and string-based
+ // lookups.
+ TEST_EQ(vecoftables->LookupByKey("Barney"),
+ vecoftables->LookupByKey(std::string("Barney")));
+ TEST_EQ(vecoftables->LookupByKey("Fred"),
+ vecoftables->LookupByKey(std::string("Fred")));
+ TEST_EQ(vecoftables->LookupByKey("Wilma"),
+ vecoftables->LookupByKey(std::string("Wilma")));
+
+#ifdef FLATBUFFERS_HAS_STRING_VIEW
+ // Tests for LookupByKey with a key that is a truncated
+ // version of a longer, invalid key.
+ const std::string invalid_key = "Barney123";
+ std::string_view valid_truncated_key = invalid_key;
+ valid_truncated_key.remove_suffix(3); // "Barney"
+ TEST_NOTNULL(vecoftables->LookupByKey(valid_truncated_key));
+ TEST_EQ(vecoftables->LookupByKey("Barney"),
+ vecoftables->LookupByKey(valid_truncated_key));
+
+ // Tests for LookupByKey with a key that is a truncated
+ // version of a longer, valid key.
+ const std::string valid_key = "Barney";
+ std::string_view invalid_truncated_key = valid_key;
+ invalid_truncated_key.remove_suffix(3); // "Bar"
+ TEST_NULL(vecoftables->LookupByKey(invalid_truncated_key));
+#endif // FLATBUFFERS_HAS_STRING_VIEW
+
// Test accessing a vector of sorted structs
auto vecofstructs = monster->testarrayofsortedstruct();
if (vecofstructs) { // not filled in monster_test.bfbs
diff --git a/tests/monster_test_generated.h b/tests/monster_test_generated.h
index e93010e..9232029 100644
--- a/tests/monster_test_generated.h
+++ b/tests/monster_test_generated.h
@@ -1432,6 +1432,12 @@
int KeyCompareWithValue(const char *_name) const {
return strcmp(name()->c_str(), _name);
}
+ template<typename StringType>
+ int KeyCompareWithValue(const StringType& _name) const {
+ if (name()->c_str() < _name) return -1;
+ if (_name < name()->c_str()) return 1;
+ return 0;
+ }
const ::flatbuffers::Vector<uint8_t> *inventory() const {
return GetPointer<const ::flatbuffers::Vector<uint8_t> *>(VT_INVENTORY);
}
diff --git a/tests/monster_test_suffix/ext_only/monster_test_generated.hpp b/tests/monster_test_suffix/ext_only/monster_test_generated.hpp
index bfd7a71..64e5065 100644
--- a/tests/monster_test_suffix/ext_only/monster_test_generated.hpp
+++ b/tests/monster_test_suffix/ext_only/monster_test_generated.hpp
@@ -1423,6 +1423,12 @@
int KeyCompareWithValue(const char *_name) const {
return strcmp(name()->c_str(), _name);
}
+ template<typename StringType>
+ int KeyCompareWithValue(const StringType& _name) const {
+ if (name()->c_str() < _name) return -1;
+ if (_name < name()->c_str()) return 1;
+ return 0;
+ }
const ::flatbuffers::Vector<uint8_t> *inventory() const {
return GetPointer<const ::flatbuffers::Vector<uint8_t> *>(VT_INVENTORY);
}
diff --git a/tests/monster_test_suffix/filesuffix_only/monster_test_suffix.h b/tests/monster_test_suffix/filesuffix_only/monster_test_suffix.h
index bfd7a71..64e5065 100644
--- a/tests/monster_test_suffix/filesuffix_only/monster_test_suffix.h
+++ b/tests/monster_test_suffix/filesuffix_only/monster_test_suffix.h
@@ -1423,6 +1423,12 @@
int KeyCompareWithValue(const char *_name) const {
return strcmp(name()->c_str(), _name);
}
+ template<typename StringType>
+ int KeyCompareWithValue(const StringType& _name) const {
+ if (name()->c_str() < _name) return -1;
+ if (_name < name()->c_str()) return 1;
+ return 0;
+ }
const ::flatbuffers::Vector<uint8_t> *inventory() const {
return GetPointer<const ::flatbuffers::Vector<uint8_t> *>(VT_INVENTORY);
}
diff --git a/tests/monster_test_suffix/monster_test_suffix.hpp b/tests/monster_test_suffix/monster_test_suffix.hpp
index bfd7a71..64e5065 100644
--- a/tests/monster_test_suffix/monster_test_suffix.hpp
+++ b/tests/monster_test_suffix/monster_test_suffix.hpp
@@ -1423,6 +1423,12 @@
int KeyCompareWithValue(const char *_name) const {
return strcmp(name()->c_str(), _name);
}
+ template<typename StringType>
+ int KeyCompareWithValue(const StringType& _name) const {
+ if (name()->c_str() < _name) return -1;
+ if (_name < name()->c_str()) return 1;
+ return 0;
+ }
const ::flatbuffers::Vector<uint8_t> *inventory() const {
return GetPointer<const ::flatbuffers::Vector<uint8_t> *>(VT_INVENTORY);
}
