From d40e98ecef776b909af4d91ffa266a966290e73f Mon Sep 17 00:00:00 2001 From: Niels Lohmann Date: Mon, 12 Jul 2021 13:38:28 +0200 Subject: [PATCH] :bug: fix assertion failure #2838 --- include/nlohmann/json.hpp | 61 ++++++++++++++++++++++++++------ single_include/nlohmann/json.hpp | 61 ++++++++++++++++++++++++++------ test/src/unit-diagnostics.cpp | 57 +++++++++++++++++++++++++++++ 3 files changed, 157 insertions(+), 22 deletions(-) diff --git a/include/nlohmann/json.hpp b/include/nlohmann/json.hpp index c55bdf54b..0622d1a9c 100644 --- a/include/nlohmann/json.hpp +++ b/include/nlohmann/json.hpp @@ -5371,8 +5371,18 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec } // add element to array (move semantics) + const auto capacity = m_value.array->capacity(); m_value.array->push_back(std::move(val)); - set_parent(m_value.array->back()); + if (capacity == m_value.array->capacity()) + { + // capacity has not changed: updating parent of last element is sufficient + set_parent(m_value.array->back()); + } + else + { + // capacity has changed: update all elements' parents + set_parents(); + } // if val is moved from, basic_json move constructor marks it null so we do not call the destructor } @@ -5407,7 +5417,18 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec } // add element to array + const auto capacity = m_value.array->capacity(); m_value.array->push_back(val); + if (capacity == m_value.array->capacity()) + { + // capacity has not changed: updating parent of last element is sufficient + set_parent(m_value.array->back()); + } + else + { + // capacity has changed: update all elements' parents + set_parents(); + } set_parent(m_value.array->back()); } @@ -5562,12 +5583,18 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec } // add element to array (perfect forwarding) -#ifdef JSON_HAS_CPP_17 - return set_parent(m_value.array->emplace_back(std::forward(args)...)); -#else + const auto capacity = m_value.array->capacity(); m_value.array->emplace_back(std::forward(args)...); - return set_parent(m_value.array->back()); -#endif + + if (capacity == m_value.array->capacity()) + { + // capacity has not changed: updating parent of last element is sufficient + return set_parent(m_value.array->back()); + } + + // capacity has changed: update all elements' parents + set_parents(); + return m_value.array->back(); } /*! @@ -5630,12 +5657,13 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec /// @note: This uses std::distance to support GCC 4.8, /// see https://github.com/nlohmann/json/pull/1257 template - iterator insert_iterator(const_iterator pos, Args&& ... args) + iterator insert_iterator(const_iterator pos, typename iterator::difference_type cnt, Args&& ... args) { iterator result(this); JSON_ASSERT(m_value.array != nullptr); auto insert_pos = std::distance(m_value.array->begin(), pos.m_it.array_iterator); + const auto capacity = m_value.array->capacity(); m_value.array->insert(pos.m_it.array_iterator, std::forward(args)...); result.m_it.array_iterator = m_value.array->begin() + insert_pos; @@ -5643,6 +5671,17 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec // result.m_it.array_iterator = m_value.array->insert(pos.m_it.array_iterator, cnt, val); // but the return value of insert is missing in GCC 4.8, so it is written this way instead. + if (capacity == m_value.array->capacity()) + { + // capacity has not changed: updating parent of inserted elements is sufficient + set_parents(result, cnt); + } + else + { + // capacity has changed: update all elements' parents + set_parents(); + } + return result; } @@ -5680,7 +5719,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec } // insert to array and return iterator - return set_parents(insert_iterator(pos, val), static_cast(1)); + return insert_iterator(pos, static_cast(1), val); } JSON_THROW(type_error::create(309, "cannot use insert() with " + std::string(type_name()), *this)); @@ -5731,7 +5770,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec } // insert to array and return iterator - return set_parents(insert_iterator(pos, cnt, val), static_cast(cnt)); + return insert_iterator(pos, static_cast(cnt), cnt, val); } JSON_THROW(type_error::create(309, "cannot use insert() with " + std::string(type_name()), *this)); @@ -5793,7 +5832,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec } // insert to array and return iterator - return set_parents(insert_iterator(pos, first.m_it.array_iterator, last.m_it.array_iterator), std::distance(first, last)); + return insert_iterator(pos, std::distance(first, last), first.m_it.array_iterator, last.m_it.array_iterator); } /*! @@ -5835,7 +5874,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec } // insert to array and return iterator - return set_parents(insert_iterator(pos, ilist.begin(), ilist.end()), static_cast(ilist.size())); + return insert_iterator(pos, static_cast(ilist.size()), ilist.begin(), ilist.end()); } /*! diff --git a/single_include/nlohmann/json.hpp b/single_include/nlohmann/json.hpp index cbe69ef47..999d136aa 100644 --- a/single_include/nlohmann/json.hpp +++ b/single_include/nlohmann/json.hpp @@ -22406,8 +22406,18 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec } // add element to array (move semantics) + const auto capacity = m_value.array->capacity(); m_value.array->push_back(std::move(val)); - set_parent(m_value.array->back()); + if (capacity == m_value.array->capacity()) + { + // capacity has not changed: updating parent of last element is sufficient + set_parent(m_value.array->back()); + } + else + { + // capacity has changed: update all elements' parents + set_parents(); + } // if val is moved from, basic_json move constructor marks it null so we do not call the destructor } @@ -22442,7 +22452,18 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec } // add element to array + const auto capacity = m_value.array->capacity(); m_value.array->push_back(val); + if (capacity == m_value.array->capacity()) + { + // capacity has not changed: updating parent of last element is sufficient + set_parent(m_value.array->back()); + } + else + { + // capacity has changed: update all elements' parents + set_parents(); + } set_parent(m_value.array->back()); } @@ -22597,12 +22618,18 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec } // add element to array (perfect forwarding) -#ifdef JSON_HAS_CPP_17 - return set_parent(m_value.array->emplace_back(std::forward(args)...)); -#else + const auto capacity = m_value.array->capacity(); m_value.array->emplace_back(std::forward(args)...); - return set_parent(m_value.array->back()); -#endif + + if (capacity == m_value.array->capacity()) + { + // capacity has not changed: updating parent of last element is sufficient + return set_parent(m_value.array->back()); + } + + // capacity has changed: update all elements' parents + set_parents(); + return m_value.array->back(); } /*! @@ -22665,12 +22692,13 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec /// @note: This uses std::distance to support GCC 4.8, /// see https://github.com/nlohmann/json/pull/1257 template - iterator insert_iterator(const_iterator pos, Args&& ... args) + iterator insert_iterator(const_iterator pos, typename iterator::difference_type cnt, Args&& ... args) { iterator result(this); JSON_ASSERT(m_value.array != nullptr); auto insert_pos = std::distance(m_value.array->begin(), pos.m_it.array_iterator); + const auto capacity = m_value.array->capacity(); m_value.array->insert(pos.m_it.array_iterator, std::forward(args)...); result.m_it.array_iterator = m_value.array->begin() + insert_pos; @@ -22678,6 +22706,17 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec // result.m_it.array_iterator = m_value.array->insert(pos.m_it.array_iterator, cnt, val); // but the return value of insert is missing in GCC 4.8, so it is written this way instead. + if (capacity == m_value.array->capacity()) + { + // capacity has not changed: updating parent of inserted elements is sufficient + set_parents(result, cnt); + } + else + { + // capacity has changed: update all elements' parents + set_parents(); + } + return result; } @@ -22715,7 +22754,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec } // insert to array and return iterator - return set_parents(insert_iterator(pos, val), static_cast(1)); + return insert_iterator(pos, static_cast(1), val); } JSON_THROW(type_error::create(309, "cannot use insert() with " + std::string(type_name()), *this)); @@ -22766,7 +22805,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec } // insert to array and return iterator - return set_parents(insert_iterator(pos, cnt, val), static_cast(cnt)); + return insert_iterator(pos, static_cast(cnt), cnt, val); } JSON_THROW(type_error::create(309, "cannot use insert() with " + std::string(type_name()), *this)); @@ -22828,7 +22867,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec } // insert to array and return iterator - return set_parents(insert_iterator(pos, first.m_it.array_iterator, last.m_it.array_iterator), std::distance(first, last)); + return insert_iterator(pos, std::distance(first, last), first.m_it.array_iterator, last.m_it.array_iterator); } /*! @@ -22870,7 +22909,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec } // insert to array and return iterator - return set_parents(insert_iterator(pos, ilist.begin(), ilist.end()), static_cast(ilist.size())); + return insert_iterator(pos, static_cast(ilist.size()), ilist.begin(), ilist.end()); } /*! diff --git a/test/src/unit-diagnostics.cpp b/test/src/unit-diagnostics.cpp index 21ced33b1..c0b5a6476 100644 --- a/test/src/unit-diagnostics.cpp +++ b/test/src/unit-diagnostics.cpp @@ -109,4 +109,61 @@ TEST_CASE("Better diagnostics") j["/foo"] = {1, 2, 3}; CHECK_THROWS_WITH_AS(j.unflatten(), "[json.exception.type_error.315] (/~1foo) values in object must be primitive", json::type_error); } + + SECTION("Regression test for https://github.com/nlohmann/json/issues/2838") + { + // void push_back(basic_json&& val) + { + json j_arr = json::array(); + j_arr.push_back(json::object()); + j_arr.push_back(json::object()); + json j_obj = json::object(); + j_obj["key"] = j_arr; + } + + // void push_back(const basic_json& val) + { + json j_arr = json::array(); + auto object = json::object(); + j_arr.push_back(object); + j_arr.push_back(object); + json j_obj = json::object(); + j_obj["key"] = j_arr; + } + + // reference emplace_back(Args&& ... args) + { + json j_arr = json::array(); + j_arr.emplace_back(json::object()); + j_arr.emplace_back(json::object()); + json j_obj = json::object(); + j_obj["key"] = j_arr; + } + + // iterator insert(const_iterator pos, const basic_json& val) + { + json j_arr = json::array(); + j_arr.insert(j_arr.begin(), json::object()); + j_arr.insert(j_arr.begin(), json::object()); + json j_obj = json::object(); + j_obj["key"] = j_arr; + } + + // iterator insert(const_iterator pos, size_type cnt, const basic_json& val) + { + json j_arr = json::array(); + j_arr.insert(j_arr.begin(), 2, json::object()); + json j_obj = json::object(); + j_obj["key"] = j_arr; + } + + // iterator insert(const_iterator pos, const_iterator first, const_iterator last) + { + json j_arr = json::array(); + json j_objects = {json::object(), json::object()}; + j_arr.insert(j_arr.begin(), j_objects.begin(), j_objects.end()); + json j_obj = json::object(); + j_obj["key"] = j_arr; + } + } }