177 Commits

Author	SHA1	Message	Date
Niels Lohmann	e5a89d671f	Fix lint debt: enum-macro NOLINTs, doctest as SYSTEM, no-op analyzer (#5737) ... * Drop stale LCOV_EXCL_LINE from the json_pointer out_of_range.410 throw The comment said the size_type overflow check in array_index() is only triggered on special platforms like 32-bit, and the throw was excluded from coverage. On 64-bit platforms the check is true for SIZE_MAX itself, and unit-json_pointer.cpp has asserted that case four times since #5395, so the line is executed in the coverage job. Reword the comment and remove the exclusion marker so the coverage report notices if the tests stop reaching it. Part of #5725 Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Name all three C-array check aliases in the enum-macro NOLINTs NLOHMANN_JSON_SERIALIZE_ENUM(_STRICT) suppressed the c-array warning under modernize-avoid-c-arrays only, but clang-tidy emits the same diagnostic under the aliases cppcoreguidelines-avoid-c-arrays and hicpp-avoid-c-arrays too. Any user running those checks got a false positive at every macro expansion, and our own tests needed a local NOLINT at each call site to work around it. Name all three aliases in the four macro comments instead, and drop the now-redundant c-array names from the five test call-site NOLINTs. Comment-only change; behavior, the public API, and the ABI do not change. Ran make amalgamate. Part of #5725 Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Include doctest as a SYSTEM directory instead of disabling warnings for all tests test_main added -Wno-deprecated and -Wno-float-equal as PUBLIC compile options for every non-MSVC compiler, so they were applied to every translation unit, library headers included, and silenced the CI warnings meant to check the library's own -Wfloat-equal pragmas. The only code that actually needed the suppression was the vendored doctest.h, which was included as a normal (non-SYSTEM) directory. Include thirdparty/doctest as SYSTEM for test_main, matching what tests/abi/CMakeLists.txt already does, and drop the two suppressions from both targets. Verified locally that unit-comparison, unit-conversions and unit-constructor1 compile clean with -Werror -Weverything and doctest as -isystem, and that CMake still configures with JSON_BuildTests=ON. Part of #5725 Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Remove the no-op ci_clang_analyze target ci_clang_analyze configured the build with the real compiler and only then wrapped ninja with scan-build. scan-build intercepts compiles by overriding CC/CXX, but build.ninja already had the compiler path baked in from the configure step, so every run bypassed the analyzer: CI logs show "No bugs found" after a normal build, never an analysis. The job also used Debian's frozen clang-tools-14 rather than the image's own clang, and CLANG_ANALYZER_CHECKS still named three valist.* checkers that current clang merged into security.VAList. ci_clang_tidy already runs every clang-analyzer-* check (via .clang-tidy's "Checks: '*'") with warnings as errors, so nothing is lost by removing the dead job. Delete ci_clang_analyze, CLANG_ANALYZER_CHECKS and the SCAN_BUILD_TOOL lookup from cmake/ci.cmake, drop it from the ubuntu.yml ci_static_analysis_clang matrix, and drop the now-unused clang-tools apt package (iwyu stays for ci_single_binaries). Reword quality_assurance.md and assurance_case.md, which described the dead job as a working control, to say the Clang Static Analyzer checks run through clang-tidy. Verified that `cmake -DJSON_CI=ON` still configures cleanly and that ci_clang_analyze no longer appears in the generated build or in any CMake/workflow file. Part of #5725 Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Re-enable portability-template-virtual-member-function; remove redundant forwards .clang-tidy disabled three checks "to get the CI going" (#4489, 2024-11-13): portability-template-virtual-member-function, bugprone-use-after-move and its alias hicpp-invalid-access-moved. portability-template-virtual-member-function only flagged output_stream_adapter::write_character/write_characters; annotate both with NOLINT and re-enable the check. bugprone-use-after-move flagged several double forwards that have no effect at runtime: - from_json.hpp calls std::forward<BasicJsonType>(j).at(Idx) inside pack expansions; at() has no ref-qualified overloads and always returns an lvalue reference, so the forward is a no-op. Replace with plain j.at(Idx) in all four places. - the move constructor forwards the whole object to its base class and then reads other's members. That is item 9 of #5724 (together with its cppcheck suppressions) and is left to that change. - input_adapters.hpp forwards the container twice on purpose, so the begin/end iterator types match adapter_type; annotate with NOLINT and a comment instead of changing behavior. The check still flags the move constructor (see above) and two sites in at(KeyType&&) (both overloads, json.hpp, in the throw's string_t(std::forward<KeyType>(key)) after find(std::forward<KeyType>(key))). Open PR #5689 rewrites that hunk, so bugprone-use-after-move (and hicpp-invalid-access-moved) stay disabled for now, with a comment explaining why; re-enable them once #5689 and the #5724 move-constructor change have landed. Also resolve the portability-avoid-pragma-once TODO: single_include never has #pragma once (amalgamate.py strips it) and every supported compiler accepts it in include/, so keep it disabled with an explanatory comment instead of a TODO. Fix the stale "json.hpp, around line 1265" comment in unit-class_parser.cpp, which now points at the move constructor's actual line. Behavior, the public API and the ABI do not change. Verified with clang-tidy 22.1.8 that portability-template-virtual-member-function now reports nothing, that bugprone-use-after-move/ hicpp-invalid-access-moved report only the known at(KeyType&&) and move-constructor sites, and that unit-custom-base-class, unit-constructor1, unit-conversions, unit-element_access2, unit-class_parser and unit-diagnostic-positions (JSON_DIAGNOSTIC_POSITIONS=1) compile under ASan/UBSan and pass with the same assertion counts as before. Ran make amalgamate. Part of #5725 Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Fix stale and malformed NOLINT comments json_sax.hpp named "-warnings-as-errors" in the NOLINT list on the two JSON_ASSERT(false) lines; that is the suffix clang-tidy appends to a diagnostic tag under WarningsAsErrors, not a check name, and every other JSON_ASSERT(false) omits it. unit-capacity.cpp carried 30 "// NOLINT(misc-const-correctness)" comments on "json j = ...;" declarations that are all used with non-const members afterwards, so the check has nothing to report there. unit-constructor2.cpp used a blanket "// NOLINT: access after move is OK here" on a use-after-move that hides every check on the line; naming bugprone-use-after-move and hicpp-invalid-access-moved keeps the intent once those checks are re-enabled (#5724). Signed-off-by: Niels Lohmann <mail@nlohmann.me> #5725 item 10 * Remove stale .clang-tidy entries -google-runtime-references disabled a check that neither clang-tidy 22.1.8 nor 23.1.2 lists under --list-checks -checks='*'; it was removed upstream. The commented-out HeaderFilterRegex line has been unused since the active HeaderFilterRegex was introduced in #2561 (2021). Signed-off-by: Niels Lohmann <mail@nlohmann.me> #5725 item 11 * Remove the GCC C++20 -Wignored-attributes pragma in json.hpp The pragma (added in #5164) claimed to work around the C++ modules redefinition errors of #5103, but #5103 is about hard errors (e.g. "redefinition of std::__is_constant_evaluated()", conflicting std::integral_constant) that ignoring a warning cannot suppress; they are traced to GCC PR 124430 and reproduce with <map> or <string> instead of json.hpp too. A GCC 16.2 -std=gnu++20 -fmodules build following #5103's repro steps still fails with the pragma in place, and a build of all test TUs with GCC_CXXFLAGS (which enable -Wignored-attributes) and the pragma removed produces no such warning. The block only hid a warning class from GCC C++20 users while suggesting #5103 was handled. Overlaps #5610, whose hunks touch the closing half of this pragma to insert the json_literals.hpp include. Signed-off-by: Niels Lohmann <mail@nlohmann.me> #5725 item 9 * Fix stale doxygen comments hidden by the -Wdocumentation pragma macro_scope.hpp ignores -Wdocumentation and -Wdocumentation-unknown-command for the whole library, which also hides genuine documentation mistakes: - detail::unescape() documented "@return unescaped string" but returns void and unescapes its argument in place; reworded to "@param[in,out] s string to unescape in place" and dropped the bogus @return. - basic_json::get()'s copy-conversion overload wrote "converted to @tparam ValueType" inside @return, which Doxygen and Clang parse as a second, malformed @tparam; changed to "@a ValueType", matching the two other get() overloads a few lines above that already use it. This narrows the gap the -Wdocumentation pragma needs to cover; fully replacing the Doxygen-only commands it also hides (item 2c) is left for after #5267. Signed-off-by: Niels Lohmann <mail@nlohmann.me> #5725 item 2 * Fix -Wextra-semi-stmt at its actual source, not assert() clang_flags.cmake blamed the global -Wno-extra-semi-stmt on assert(), but assert() expands to an expression under glibc and libc++ and does not trigger this warning. unit-assert_macro.cpp overrides JSON_ASSERT with "{if (!(x)) ++assert_counter; }", a bare block followed by a semicolon at every JSON_ASSERT(...) call site in the library; that was the actual source of 151 of the 208 -Wextra-semi-stmt sites found in a Clang 22 -Weverything sweep of the test suite with the flag removed. Switched to the standard do/while(false) macro idiom, which does not expand to a statement-plus-semicolon, and corrected the comment to name the remaining source instead: vendored Doctest's CAPTURE(x) shim, which already ends in a semicolon. Verified with clang++ -Wextra-semi-stmt (plus the file's other CI ignores) that unit-assert_macro.cpp now compiles without any -Wextra-semi-stmt diagnostic. Signed-off-by: Niels Lohmann <mail@nlohmann.me> #5725 item 8 (step 1 of 2; step 2 covers the CAPTURE() call sites) * Drop the redundant semicolon from CAPTURE() call sites; remove -Wno-extra-semi-stmt doctest_compatibility.h defines CAPTURE(x) as DOCTEST_CAPTURE(x); (with a trailing semicolon baked into the macro), specifically so call sites do not need to add one themselves; most of the ~267 call sites already follow that convention. The remaining 64 call sites across 20 files wrote "CAPTURE(x);" anyway, turning into a statement plus an empty statement and triggering -Wextra-semi-stmt. Dropped the redundant semicolon at each of those sites. With item 6 having already made vendored Doctest a SYSTEM include, and this the last known source of -Wextra-semi-stmt findings, removed the flag from clang_flags.cmake entirely. Verified with clang++ -Wextra-semi-stmt (plus the file's other CI ignores) that all 20 touched files, plus a file with no CAPTURE() use (unit-json_pointer.cpp), compile without any -Wextra-semi-stmt diagnostic. Signed-off-by: Niels Lohmann <mail@nlohmann.me> #5725 item 8 (step 2 of 2) * Switch ci_static_analysis_clang off the frozen LLVM 22 dev image ubuntu.yml pinned the clang-tidy/clang-tidy-sanitizer/single-binaries job to silkeh/clang:dev, a tag last pushed 2026-02-18 that reports "clang version 22.0.0 (...+20251015...)", a pre-release snapshot from before the LLVM 22 release; the maintainer now updates dev-unstable, 22, and latest instead. Switched to silkeh/clang:22, matching the other clang jobs on :latest. Verified with clang-tidy 22.1.8 (the image's actual version) against this repository's .clang-tidy and library headers what the release image newly reports compared to :dev: - readability-redundant-typename fires at ~250 sites across the _cpp20-relevant conversion/to_chars headers; the library targets C++11 and keeps the typenames, so the check is disabled in .clang-tidy, matching how the file already handles checks that don't fit a C++11 codebase. - misc-anonymous-namespace-in-header fires on the two anonymous namespaces in from_json.hpp and to_json.hpp; added the alias to their existing NOLINT (cert-dcl59-cpp, fuchsia-header-anon-namespaces, google-build-namespaces). - bugprone-std-namespace-modification fires on every addition to namespace std: the std::hash, std::formatter and std::swap overloads in json.hpp, and the std::tuple_size/std::tuple_element specializations in iteration_proxy.hpp (this last file is not named in #5725's item 5, found by actually running clang-tidy 22.1.8 against the current tree). All six are legal, deliberate additions to namespace std (explicit/partial specializations of std types, or the pre-C++20 std::swap overload); annotated each with the check name next to its existing cert-dcl58-cpp NOLINT. - modernize-avoid-c-style-cast reported nothing new. Also added clang++-22/21, clang-tidy-22/21, g++-16 and gcov-16 to the find_program search lists in ci.cmake so a local "maximal warnings" configure prefers the current toolchain version over an older one on PATH. #5725 item 5 Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Regenerate cmake/gcc_flags.cmake for GCC 16.2.0 GCC_CXXFLAGS was generated for GCC 15.1.0, but ci_test_gcc and ci_test_gcc_cxx{11..26} now run in gcc:latest, currently GCC 16.2.0, so the "maximal warnings" job was missing warnings introduced since 15.1.0 while carrying entries GCC 16 treats as duplicates or no-ops. Regenerated with https://github.com/nlohmann/gcc_flags (patched locally to not crash on an option whose "-x c++ <opt> -" probe fails before it reads stdin, e.g. -Wabi=; the tool otherwise raises BrokenPipeError instead of recording the option as an error) run against g++ 16.2.0 in the official gcc:16 Docker image, keeping the documented -Wno-* exclusions and the same alphabetical placement scheme as before. Also added three GCC 16 warnings the generator cannot discover on its own because it only probes value ranges/lists it finds in the -Q option name itself, not in the enum choices --help=warnings documents separately: - -Wbidi-chars=any, -Wleading-whitespace=spaces: manually verified these compile cleanly with g++ 16.2.0. - -Wstrict-flex-arrays: deliberately NOT added, unlike the other two. Without -fstrict-flex-arrays (which the library does not enable, as it would change codegen for flexible array members), GCC prints "'-Wstrict-flex-arrays' is ignored when '-fstrict-flex-arrays' is not present" on every translation unit, and under our -Werror that note itself aborts the build. This differs from the harmless no-op warnings already kept in the file (-Whsa, -Wsynth, -Wunreachable-code, -Wunsafe-loop-optimizations), which emit nothing; #5725 item 7 named -Wstrict-flex-arrays as one of the flags GCC 16 adds, but did not anticipate this failure mode. Verified: compiled the library header and a representative set of test translation units (including ones touched by items 1, 3, 8, 9, 10 of this issue) with the regenerated GCC_CXXFLAGS plus -Werror under g++ 16.2.0 at -std=c++11 through -std=c++26, with zero warnings; ran the full local test suite (129/129 passing, unrelated to this compiler) as a regression check. CI must still confirm the actual ci_test_gcc / ci_test_standards_gcc targets end to end, since this was verified with direct g++ invocations rather than through the CMake/ CXXFLAGS environment-variable plumbing in ci.cmake. #5725 item 7 Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Avoid std::basic_string<CharType> for non-character output_adapter CharType output_adapter<CharType, StringType> defaulted StringType to std::basic_string<CharType>, and (with JSON_NO_IO undefined) always declared a std::basic_ostream<CharType>&-taking constructor. For CharType with no non-deprecated std::char_traits specialization (only std::uint8_t is ever used this way, by the binary writers), simply naming either type - as an unused default template argument, or as an unused, never-called constructor's parameter type - instantiates std::char_traits<CharType> merely to name it, which some standard libraries mark deprecated: with the library-wide -Wdocumentation pragma (item 2's other half, left for a later commit) temporarily removed, an Apple clang 21 / libc++ TU calling json::to_cbor(j, vec) with std::vector<std::uint8_t>& got one -Wdeprecated-declarations warning per binary writer at the old output_adapters.hpp:193. Replaced the eager std::basic_string<CharType> / std::basic_ostream <CharType> defaults with a bool-tagged partial specialization (not std::conditional, which requires naming both branches' types up front regardless of which is selected, reproducing the same warning) that only ever names std::basic_string<CharType> / std::basic_ostream <CharType> when CharType is actually one of char, wchar_t, char16_t, char32_t, or (with __cpp_lib_char8_t) char8_t. For any other CharType, output_adapter's StringType and ostream-constructor parameter fall back to two distinct empty placeholder types, kept distinct so the two constructor overloads do not collide into a single redeclaration. Public API / behavior: passing a std::basic_string<std::uint8_t>& or std::basic_ostream<std::uint8_t>& directly to a binary writer's output_adapter now fails to compile instead of compiling with a deprecation warning; this was neither documented nor tested. All documented uses (std::vector<CharType>, std::basic_ostream<CharType> and StringType for character CharType) are unaffected. Verified with Apple clang 21 / libc++, with the two -Wdocumentation* "ignored" pragma lines in macro_scope.hpp temporarily removed and -std=c++11/c++20 plus the project's -Weverything flag set: calling to_cbor/to_msgpack/to_ubjson/to_bjdata/to_bson/to_bon8 on a std::vector<std::uint8_t> now produces no char_traits<unsigned char> (or any other) deprecation warning, while the char-based string- and ostream-adapter paths, and a to_cbor/from_cbor round trip, still compile and run correctly; also verified with GCC 16.2.0. Ran the full local test suite, including the binary-format unit tests (unit-cbor, unit-msgpack, unit-ubjson, unit-bjdata, unit-bson, unit-bon8, unit-binary_writer_sinks, unit-binary_formats, unit-custom-binary-type): 129/129 passing. #5725 item 2 (step a) Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Remove the library-wide -Wdocumentation pragma; fix what it hid macro_scope.hpp / macro_unscope.hpp pushed and popped a Clang diagnostic region over the entire library that ignored -Wdocumentation and -Wdocumentation-unknown-command. Removed both pragmas and fixed every finding a full -Wdocumentation (which implies -Wdocumentation-unknown-command and -Wdocumentation-deprecated-sync) build reports, so the library now compiles clean under Clang's documentation checks without a blanket suppression. Overlaps #5267, which is still open and edits a nearby doc block (json.hpp's get()/get_impl() @return, already fixed in the item 2 step (b) commit of this branch); this commit does not touch that block again. Unknown Doxygen alias commands (Doxyfile removed in #3071, so these were never rendered by anything) rewritten as plain prose, keeping the same information: - @requirement REQ-JSON-01 / REQ-JSON-02 (iter_impl.hpp, json_reverse_iterator.hpp): now "This class satisfies the following concept requirements (REQ-JSON-0N):". - @liveexample{prose,example-id} (three sites in json.hpp): kept the prose, dropped the command wrapper and the trailing example-id (docs/mkdocs/docs/examples/*.cpp still exist and are used directly by the rendered docs, not through this in-header alias) and unescaped the "\," commas that were only needed for the old alias's comma-separated argument syntax. - @complexity X (json.hpp x4, json_pointer.hpp x2, serializer.hpp x1): now "Complexity: X". Backslash sequences Clang's comment lexer tried to parse as commands, escaped to render as literal backslashes: - lexer.hpp get_codepoint(): two `\u` occurrences. - binary_reader.hpp get_bson_cstr() / get_bson_cstr_bulk(): two `\x00` occurrences. - serializer.hpp: three `\uXXXX` occurrences (constructor @param, append_codepoint_to_string_buffer() @brief, and the ensure_ascii member comment). One finding remained after all of the above: Clang reports "declaration is marked with '@deprecated' command but does not have a deprecation attribute" on the deprecated sax_parse(span_input_adapter&&, ...) overload, even though JSON_HEDLEY_DEPRECATED_FOR does expand to __attribute__((deprecated(...))) for Clang. Several isolated reproductions of this exact declaration shape - doc comment, template<>, two stacked __attribute__ macros, an overload set sharing the name - did not reproduce the warning, so this looks like a Clang comment/declaration-association quirk specific to this overload inside the much larger basic_json class template, not an actual documentation defect. Rather than keep the pragma library-wide for one Clang false positive, added a tightly scoped -Wdocumentation-deprecated-sync push/pop around just that overload. Verified with Apple clang 21 and the project's actual -Weverything flag set (cmake/clang_flags.cmake) on the full header at -std=c++11 and -std=c++20: zero -Wdocumentation* diagnostics. Also compiled clean with GCC 16.2.0 (the pragmas are already __clang__-gated, so this only confirms no unrelated breakage). Ran make check-amalgamation and the full local test suite: 129/129 passing. #5725 item 2 (step c) Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Take the JSON value by const reference in the array and tuple from_json paths Review feedback on #5737 (gregmarr): once the no-op std::forward calls are gone, the forwarding references have no purpose. from_json_fn passes the value as const BasicJsonType&, so these functions were only ever instantiated with a const lvalue anyway. The std::array, std::pair and std::tuple overloads of from_json and their helpers now take const BasicJsonType& and pass j on unchanged. Because the deduced BasicJsonType is now the plain type, tuple_type and the static_assert name const BasicJsonType& explicitly, so the reference checks are unchanged: get<std::tuple<const std::string&>>() still works, and get<std::tuple<std::string&>>() still fails the same static_assert. from_json_tuple_get_impl keeps its forwarding reference, since tuple_type calls it through std::declval. Behavior, the public API and the ABI do not change. unit-conversions, unit-constructor1, unit-udt, unit-udt_macro, unit-regression1/2/3, unit-deserialization, unit-noexcept, unit-items, unit-allocator, unit-custom-object-type, unit-ordered_json2 and unit-brace-init-copy-semantics pass at C++11, C++17 and C++20 with unchanged assertion counts. Ran make amalgamate. Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-10-01 07:37:47 +02:00
Niels Lohmann	cff0a61369	Share DOM SAX position handling; fix stale parser and lexer comments (#5731) ... * Share the diagnostic-position setter of the DOM SAX parsers json_sax_dom_parser and json_sax_dom_callback_parser each had a private copy of handle_diagnostic_positions_for_json_value(), identical except for comments. Move the body into one static member function, detail::diagnostic_positions::set_from_lexer(value, lexer), which both classes call with their lexer pointer. basic_json befriends the new struct (only when JSON_DIAGNOSTIC_POSITIONS is enabled), as the position members are private. The discarded case is reached through the callback parser, so the LCOV_EXCL markers that only the dom parser's copy had are gone. The NOLINT on the unreachable default case loses the stray "-warnings-as-errors", which is not a check name. The start-position setup in start_object()/start_array() is left alone, as #5706 is editing the callback parser's versions. Behavior, the public API and the ABI are unchanged. Part of #5712 Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Correct the parser comments on recursion and skip_to_state_evaluation The class documentation called the parser a recursive descent parser, but sax_parse_internal() is a loop that keeps the open containers on an explicit stack. The comment at the end of an array and of an object said the flag is set to false while the code below it sets it to true. Describe what the code does instead. Comments only; behavior, the public API and the ABI are unchanged. Part of #5712 Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Update the discard_number_values comments to the current number path The comments explaining the accept() shortcut in convert_number() and the member documentation still argued in terms of strtoull()/strtoll() and errno, which #5283 replaced with convert_integer(), and pointed at scan_number() instead of convert_number(). They also did not say that scan_number_bulk_contiguous() converts integers itself, so the shortcut is only reached for input without bulk access, with JSON_DIAGNOSTIC_POSITIONS, or when the bulk scanner falls back. Rewrite both comments to describe the digit-count check in front of convert_integer(), keeping the 18-digit bound and the json_sax_acceptor argument. The stale <cstdlib> comment is left for after #5616, which edits that include block. Comments only; behavior, the public API and the ABI are unchanged. Part of #5712 Signed-off-by: Niels Lohmann <mail@nlohmann.me> * List the UTF-8 validators instead of calling the DFA the only one The documentation of decode() called the Hoehrmann DFA the single source of truth for UTF-8 validation. It is used only by the serializer and by is_valid_utf8() (CBOR/MessagePack/BSON/UBJSON/BJData text strings). The lexer's scan_string() switch, validate_one_utf8() / valid_utf8_prefix() (bulk string scan, BON8 bulk path and BON8 writer) and the BON8 byte path in get_bon8_string() check the RFC 3629 ranges on their own. Replace the sentence with a list of the four validators, what each is used for, and a note that they must accept the same sequences. Sharing code between them was considered and dropped: it would save a few lines in a validator that is entangled with BON8 pushback, and #5677 is editing the BON8 byte path. Comments only; behavior, the public API and the ABI are unchanged. Part of #5712 Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Fix stale doc comments and include lists in the input headers input_adapters.hpp included <memory> and <numeric> for the removed shared_ptr-based adapter design but used neither; it called (std::min) without including <algorithm>. json_sax.hpp used std::numeric_limits without including <limits>. Also corrected comments that no longer matched the code: input_stream_adapter does not skip the input's BOM (the lexer's skip_bom() does), the span_input_adapter comment named the no-longer-existing input_buffer_adapter type, lexer::get_string() does not reset the token, binary_reader's get_number() doc opened with /* instead of /*! (so Doxygen skipped it) and omitted BON8 from its endianness note, and the UBJSON-binary-types note did not mention that BJData 'B' arrays are read as binary. Left out: the lgtm suppression on lexer.hpp's scan_number() (in #5616's hunk) and the "-1 if unknown" wording in json_sax.hpp's start_object/start_array docs (in draft #5267's hunk), per the verdict's conflict list. Part of #5712 Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Deduplicate the strict-EOF/release_lookahead/error block in parser::parse() json_sax_dom_callback_parser and json_sax_dom_parser branches of parser::parse() ran the same ~25 lines after sax_parse_internal(): the strict-mode EOF check (raising parse_error.101 through the SAX parser), release_lookahead() in non-strict mode, and mapping an errored SAX parser to a discarded result. The two copies had already drifted apart in formatting and in the second copy's "see above" comment. Add a private parse_dom(DomSax&, strict) member that runs this shared sequence once and returns whether the SAX parser did not error; both branches of parse() now only construct their DOM SAX parser, call parse_dom(), and (for the callback parser) map a discarded top-level value to null. sax_parse() is left untouched, since it only runs the EOF check and release_lookahead() when sax_parse_internal() succeeded, unlike parse(), which runs them unconditionally. Behavior-preserving: same operations in the same order for both SAX parser kinds. Verified with unit-class_parser (strict/non-strict, callback and non-callback), unit-deserialization and unit-disabled_exceptions (JSON_NOEXCEPTION), plus a clean make amalgamate / make check-amalgamation diff. Overlaps #5601, which touches the same lines. Signed-off-by: Niels Lohmann <mail@nlohmann.me> #5712 item 2 * Share the code point to UTF-8 encoding between the wide-string helpers and the lexer The 1/2/3/4-byte UTF-8 encoding ladder was written out by hand three times: in wide_string_input_helper<..., 4>::fill_buffer() for a UTF-32 code point, in the UTF-16 helper for both a BMP code unit and a valid surrogate pair, and in the lexer's \uXXXX/\uXXXX\uYYYY handling. The copies had drifted: the UTF-32 helper masked the leading bits of each byte (& 0x1Fu, & 0x0Fu, & 0x07u) where the others relied on the shift alone, even though both give the same result for a code point that is already known to be in range. Add detail::encode_utf8(cp, out) in string_utils.hpp, a single encoder that invokes a callable once per output byte, most significant byte first. Use it in the three valid-code-point branches (UTF-32 code points up to U+10FFFF, UTF-16 code units outside the surrogate range, and valid UTF-16 surrogate pairs) and in the lexer's \u handling, where out forwards to add(). The UTF-16 helper's deliberate pass-through of malformed surrogate units and the UTF-32 helper's 0xFF sentinel for code points above U+10FFFF are untouched, since neither reaches the new helper. Behavior-preserving: same bytes in the same order for every valid code point, verified with unit-class_lexer, unit-class_parser, unit-deserialization, unit-wstring and the non-test-data parts of unit-unicode1..5 (ASan/UBSan, C++11/17/20), and an escape-heavy parse microbenchmark that shows no change (about 73 ms either way, median of 3, 1M escape sequences). single_include/ regenerated with make amalgamate; make check-amalgamation leaves a clean tree. Overlaps #5704, which rewrites the wide_string_input_helper specializations touched here. Signed-off-by: Niels Lohmann <mail@nlohmann.me> #5712 item 6 --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-10-01 07:32:32 +02:00
Niels Lohmann	c261578431	Deduplicate binary reader/writer helpers and fix stale comments (#5730) ... * Fix stale and missing comments in binary_writer The doc block of write_number() ended up above the byte_swap() helpers added in #5286, about 80 lines from the function. It was also a plain comment that Doxygen skips, said "write a number to output input", and left BON8 out of the big-endian formats. Move it back onto write_number() as a /*! block and fix the text. write_bson() documented "@pre j.type() == value_t::object", but it throws type_error.317 for every other type, and to_bson() relies on that. Document the exception instead. Explain why the CBOR binary subtype is always written with a 0xD8..0xDB head and never in the one-byte tag form: binary_reader with cbor_tag_handler_t::store only keeps those heads as a subtype, so switching to write_cbor_head() would break round trips for subtypes 0..23. Also fix the grammar of the to_char_type comment. Comments only; no change in behavior, API or ABI. Part of #5710 Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Merge the duplicated UBJSON/BJData integer marker ladders write_number_with_ubjson_prefix() (unsigned and signed overloads) and ubjson_prefix() (number_integer and number_unsigned cases) each picked the UBJSON/BJData integer marker (i, U, I, u, l, m, L, M, H) with their own independent if/else ladder, and the values beyond 64 bits were handled by a second, tag-dispatched pair of ladders. An optimized container announces the marker of its first element via ubjson_prefix() and then writes every element through write_number_with_ubjson_prefix(), so the two had to be kept in lockstep by hand across four call sites. Replace all of that with one ubjson_integer_prefix() built on value_in_range_of<T>, and one write_ubjson_integer_payload() that writes the value (or, for 'H', the decimal digits) for a given marker. write_number_with_ubjson_prefix() and ubjson_prefix() keep their signatures and now just call these two helpers. Behavior, the public API and the ABI are unchanged. Verified with a new regression test covering scalars and $-optimized arrays/objects at every int8/uint8/int16/uint16/int32/uint32/int64/uint64 boundary for to_ubjson/to_bjdata (both use_size/use_type settings), and by diffing to_ubjson/to_bjdata output before and after over the json_test_data corpus (bit-identical). Part of #5710 Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Remove dead get_char parameters in binary_reader The non-recursive rewrite of the binary readers (#5505, #5506, #5507) left parse_cbor_internal()'s and parse_ubjson_internal()'s get_char parameters dead: parse_cbor_internal() has one caller and it always passes true, and parse_ubjson_internal() has one caller and it always uses the true default. Both parameters, and the @param docs describing the "reuse the last character" mode they used to select, no longer correspond to anything. Drop both parameters, initialise fetch/prefix unconditionally, and update the two call sites in sax_parse(). parse_cbor_value()'s and get_ubjson_string()'s own get_char parameters are unrelated and are left alone; both still have a false caller. Also delete a stray `@return whether a valid MessagePack value was passed to the SAX parser` doxygen block that sits directly above parse_msgpack_value()'s real doc comment, a leftover of the same rewrite. Behavior, the public API and the ABI are unchanged; these are private members of detail::binary_reader. Verified by compiling with -Wunused-parameter and running unit-cbor, unit-ubjson, unit-bjdata and unit-msgpack (offline, against the stubbed test_data.hpp). Part of #5711 Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Share the IEEE half-precision decoder between CBOR and BJData binary_reader had two ~45-line copies of the IEEE 754 half-precision decoder: CBOR's case 0xF9 and BJData's case 'h'. Once formatting is normalised, the two blocks were identical except for the byte order used to assemble the 16-bit half (CBOR is big endian, BJData is little endian). Any future change to half-float decoding had to be made and kept in sync in both places. Add one get_half_float(format, little_endian) helper that does the two get()/unexpect_eof() reads, assembles the half in the requested byte order, decodes it per RFC 8949 Appendix D, and calls sax->number_float. Both cases now just call it with their byte order; the BJData case keeps its bjdata-only guard. Behavior, the public API and the ABI are unchanged. Verified with a scratch probe comparing the old and new decoders bit-for-bit (NaN by isnan()) over all 65536 wire byte pairs, in both formats, and by running unit-cbor and unit-bjdata (offline, against the stubbed test_data.hpp). Part of #5711 Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Deduplicate the MessagePack unsigned-integer writer ladder The number_integer (non-negative branch) and number_unsigned cases in write_msgpack() each held their own copy of the fixint/uint8/16/32/64 ladder, kept in lockstep only by a comment ("we used the code from the value_t::number_unsigned case here"). Both copies mixed union members: the signed copy compared number_unsigned but wrote number_integer, and vice versa. Extract write_msgpack_unsigned(std::uint64_t), mirroring how write_cbor_head() already avoids the same duplication for CBOR, and call it from both cases. Each case now reads only its own active union member. Output bytes are unchanged for the default 64-bit number types. #5710 item 3 Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Unify float marker selection and fix the long double compile error Four formats picked between a float32 and float64 marker through four different helper styles: dummy-argument overloads for CBOR and MessagePack, an std::is_same template for BON8, and a runtime if-chain on input_format_t for write_compact_float(). With number_float_t set to long double, to_cbor, to_msgpack and to_ubjson failed inside the library with "call to 'get_cbor_float_prefix' is ambiguous", while to_bson kept working because write_bson_double() takes a plain double. Change write_compact_float() to take the two marker bytes directly (each of its three callers already knows them at compile time) instead of an input_format_t it only forwarded, and delete the now-unused get_cbor_float_prefix(), get_msgpack_float_prefix(), get_bon8_float_prefix() and get_compact_float_prefix() helpers. Turn the two get_ubjson_float_prefix() overloads into one template. Both write_compact_float() and get_ubjson_float_prefix() now report an unsupported number_float_t with a static_assert naming the requirement, rather than an ambiguous-overload error; the assert lives in the function body, not the class scope, so to_bson with long double is unaffected. Verified with a probe basic_json<..., long double>: to_bson still compiles and round-trips, while to_cbor/to_msgpack/to_ubjson now fail to compile with the new static_assert message. This changes the text of an existing compile error for users with an unsupported number_float_t (documented as a public-API-visible change in #5710). #5710 item 1 Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Deduplicate the BJData ndarray writer's dtype dispatch and drop <map> write_bjdata_ndarray() built a 12-entry std::map<string_t, CharType> on every call just to translate the _ArrayType_ name to a dtype marker (the only reason binary_writer.hpp included <map>), then mapped dtype to C++ type twice more: once as a switch for the range-check pass and once as a separate if/else chain for the write pass, with nothing checking that the two agreed. The caller also ran three at() lookups, and the callee called value.at(key) about ten more times for the same three members. Replace the map with bjdata_ndarray_type_marker(), a plain string comparison chain (a C++11 constexpr function cannot contain a switch, so this mirrors binary_reader's own static table style). Replace the switch/if-chain pair with one write_bjdata_ndarray_elements() that switches on dtype once and calls a per-type helper - write_bjdata_ndarray_element<T>() for the eight integer dtypes and write_bjdata_ndarray_float_element() for 'd' - with a dry_run flag selecting the range check or the actual write, so the two passes can no longer disagree on the type. _ArrayType_, _ArraySize_ and _ArrayData_ are now looked up once into references, and the four header marker bytes ('[', '$', '#') are written through to_char_type() like the rest of the UBJSON/BJData writer. The 'd' (single-precision) rule is left exactly as before, since #5707 is expected to change it separately. Verified byte-for-byte identical output before/after for every dtype (including the Draft 2/Draft 3 'byte' fallback and the use_count/ use_type combinations) via a standalone probe, plus round-tripping through from_bjdata(). Overlaps #5707, which is expected to touch the 'd' dtype case, and #5518, which is expected to move the write_bjdata_ndarray() call site. #5710 item 4 Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Assert that write_bson_document() consumes every calc_bson_sizes() entry calc_bson_sizes() and write_bson_document() are a hand-synchronized pair of passes over the same object/array tree, introduced by #5553: the size pass appends to nested_sizes in visiting order, and the write pass consumes the table by position with nested_sizes[next_size++]. Nothing checked that the write pass consumed the whole table. If a future change touched only one of the two passes - for example to skip or reject an entry - every later size prefix in the document would be silently wrong. Add JSON_ASSERT(next_size == nested_sizes.size()) where write_bson_document() returns, so such a future drift between the two passes is caught immediately (JSON_ASSERT expands to nothing in release builds using assert(), and the fuzzers/tests already build with it enabled). The two passes agree today, so this changes nothing observable; it only guards against the risk described in #5710 item 5. Extracting a shared stepper for the two passes (the second half of the proposed change) is left for a follow-up: it only saves ~30 lines and the issue asks for it only if the result reads clearly, which needs more room to get right than a mechanical cleanup pass allows. #5710 item 5 Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Make the BJData lookup tables static functions instead of members binary_reader held bjd_optimized_type_markers and bjd_types_map as non-static const members (12 string_t objects for the type-name table), built and destroyed on every from_cbor/from_msgpack/from_bson/ from_ubjson/from_bon8/from_bjdata call even though only from_bjdata ever reads them. They also needed the #define/decltype/#undef workaround from #3637 and two NOLINTNEXTLINE suppressions, and binary_writer already carries the same two lists in another form (is_bjdata_excluded_type_marker() and a local std::map in write_bjdata_ndarray(), the latter removed by the item-4 commit), so the excluded-marker lists could drift apart. Replace bjd_optimized_type_markers with static constexpr is_bjd_excluded_optimized_type(char_int_type), using the same ||-chain as binary_writer's is_bjdata_excluded_type_marker(). Replace bjd_types_map with a non-constexpr static bjd_type_name(char_int_type) switch returning nullptr for an unknown marker (a C++11 constexpr function cannot contain a switch). Delete both JSON_BINARY_READER_MAKE_* macros, the bjd_type pair alias, the NOLINTNEXTLINE suppressions, detail::make_array() (no longer used anywhere), and the now-unused <algorithm> and <array> includes. Update the two call sites (the ND-array excluded-type check and the _ArrayType_ lookup) accordingly, and replace unit-bjdata.cpp's "LUT arrays are sorted" section, which only checked the two tables' internal ordering, with a check of all 12 type names and all 8 excluded markers against both new functions. #5711 item 1 Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Read CBOR's 1/2/4/8-byte argument through one helper parse_cbor_internal() hand-wrote the same "read a 1/2/4/8-byte big-endian unsigned integer" ladder four times over: - twice for tag numbers 0xD8-0xDB, once in the tag_handler::ignore branch and once, nearly identically, in the ::store branch (~90 lines to read one integer); - twice more for container lengths, once for array heads 0x98-0x9B and once for map heads 0xB8-0xBB, where the 1/2-byte forms called enter_array()/enter_object() directly and the 4/8-byte forms additionally went through get_cbor_container_size(). Add get_cbor_argument(std::uint64_t&), reading the width selected by current & 0x1F via the same get_number() calls as before (so EOF is reported exactly as before), and route all four sites through it: - 0xD8-0xDB now read the argument once per branch instead of switching on `current` a second time; behavior split cleanly from embedded tags 0xC0-0xD7 (tag value in the head, no argument to read), which is now its own case block that no longer has to fall into the ::store switch's "default" case to reach the same tag_pending = true; return true; outcome. - 0x98-0x9B and 0xB8-0xBB collapse into one case block each, always going through get_cbor_container_size() (harmless for 1/2-byte lengths, which already always fit). Verified byte-for-byte identical behavior before/after with a standalone probe covering embedded and multi-byte tags under all three tag_handler_t settings, a tag over a byte string (subtype path), truncated tag/length arguments of every width, and array/map lengths of every width, including the out_of_range.408 "excessive size" case: same exceptions, same messages, same chars_read, same successful results. Left the string/byte-string length ladders in get_cbor_string()/ get_cbor_binary() untouched, as noted in #5711 item 2, since #5325 is expected to touch them separately. Overlaps #5601 (adds a branch right above the embedded-tag case) and #5607 (touches the integer cases 0x18-0x1B, which share this ladder's shape in separate hunks). #5711 item 2 Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Add leave_container() to match enter_container() Every container is opened through enter_container(), whose docs promise that a check placed there runs before every start event. The close side had no equivalent: the same "container_stack.pop_back(); dispatch to end_object() or end_array()" sequence was written out separately in BSON, CBOR, MessagePack, UBJSON/BJData and BON8, each copying the pattern of keeping an is_object flag around the pop_back() that would otherwise invalidate a reference to it. A check needed on close would have had to be added in five places, and a sixth copy could go unnoticed. Add leave_container() next to enter_container(), doing the same pop-then-dispatch, and replace the five sites with it. Each site keeps its own surrounding logic (BSON's check_bson_document_size() call before popping, MessagePack's is_object copy used again below, UBJSON/BJData's remaining-container handling after popping, BON8's top used again below); only the repeated pop/dispatch line pair is now shared. Verified all six binary-format unit suites and unit-regression2's deep-nesting tests (dependent count/reuse count and the bjdata ndarray depth cases) still pass, compiled with -Wall -Wextra and ASan/UBSan. Overlaps #5601, which is expected to add a sixth close site in its own skip loop; that site can route through leave_container() too once it lands. #5711 item 4 Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Stop passing the input format to sax_parse() when the reader already has it binary_reader's constructor stores the format in the input_format member, and sax_parse(format, sax_, strict, tag_handler) took the same value again purely to dispatch on it. Every in-tree caller passed the same value both times (all 16 from_cbor/from_msgpack/from_ubjson/ from_bjdata/from_bon8/from_bson call sites in json.hpp, and the three public basic_json::sax_parse() overloads), so nothing was broken today, but a caller of the detail class directly (only reachable via JSON_PRIVATE_UNLESS_TESTED, as unit-bjdata.cpp already does) could pass a mismatched pair - say bjdata to the constructor and ubjson to sax_parse - and dispatch on one format while applying the other format's rules; the default-constructed input_format_t::json reader would additionally hit JSON_ASSERT(false) in exception_message() on its first error. Add sax_parse(json_sax_t*, bool, cbor_tag_handler_t) forwarding to the existing overload with the stored input_format, and switch every caller to it: the 16 from_*() sites (keeping their `// cppcheck-suppress[accessMoved]` comments) and the three basic_json::sax_parse() overloads, all of which already had the format available from their own `format` parameter. The four-argument overload is kept for anyone still calling it, now with JSON_ASSERT(format == input_format) so a mismatch fails immediately in a debug build (assert-enabled binaries, including the fuzzers and test suite) instead of misbehaving; verified with a probe that constructs a reader for one format and calls the explicit overload with another, which aborts on that assertion as expected. Removing or asserting against the constructor's input_format_t::json default, which would affect direct detail users, is left as a separate decision per #5711 item 5. Overlaps #5601, which is expected to add an AllowRecovery template parameter to sax_parse() and touch these same call sites in json.hpp. #5711 item 5 Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Deduplicate UBJSON/BJData signed-count handling, drop dead ndarray checks get_ubjson_size_value()'s 'i'/'I'/'l'/'L' cases each read a differently sized signed integer and then repeated the same "reject negative with error 113" check; only 'L' additionally checked value_in_range_of for the out_of_range.408 case. Any change to that error path had to be made four times. Add get_ubjson_signed_count<SignedType>(std::size_t&), doing the read, the negative check and the range check once, and route all four markers through it. The range check is a no-op for 'i'/'I'/'l' (their values always fit std::size_t) and only live for 'L' on a 32-bit std::size_t target, matching today's behavior exactly. In the ndarray dimension-product loop, the preceding loop already returns early on any zero dimension and result starts at 1, so `i > 0` in the pre-multiplication overflow check was always true, and `result == 0` in the post-multiplication check could not be reached either: two positive factors whose product does not overflow (as the pre-check already guarantees) cannot be zero. Drop the dead `i > 0 &&` and narrow the post-check to `result == npos`, the one case the pre-check cannot rule out (an exact, non-overflowing match with the sentinel reserved for unknown-size containers), with a comment explaining why. Verified byte-for-byte identical behavior before/after with a standalone probe covering negative counts for every marker, a matching positive count, and ndarray inputs, plus the full unit-ubjson and unit-bjdata suites (same assertion counts as before this change). Overlaps #5601 (rewrites the four parse_error calls and the overflow checks touched here) and #5607/#5707 (touch neighboring lines in the same functions). #5711 item 6 Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Drop redundant format parameter and dummy float argument (review) binary_reader::sax_parse(format, ...) only ever had to equal the format given to the constructor, which it asserted. With every caller already on the format-less overload, remove the four-argument overload and dispatch on the stored input_format directly. binary_reader is a detail class, so this is not a public API change. get_ubjson_float_prefix() took a value only to deduce its type; make the type an explicit template argument instead. Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-09-30 22:48:32 +02:00
Niels Lohmann	9e1a09eec0	Name the key type when rejecting non-string CBOR/MessagePack map keys (#5594) ... * Name the key type when rejecting non-string CBOR/MessagePack map keys CBOR and MessagePack allow map keys of any type, but JSON object keys are always strings, so such maps are rejected. The error so far was the one for a malformed string (e.g. "expected length specification (0xA0-0xBF, 0xD9-0xDB); last byte: 0xC0" for a nil key), which does not tell the user what went wrong. Report the type of the key instead: syntax error while parsing MessagePack object key: only string keys are supported, but found nil; last byte: 0xC0 The exception id (parse_error.113) and type are unchanged. Malformed string keys and a missing key keep their previous messages. Document the restriction on the CBOR and MessagePack pages. Refs #2766, #3381 Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Point the MessagePack key note to the spec's profile section The note linked to "Serialization: type to format conversion", which says nothing about key types. Restricting map keys to strings is only mentioned in the "Profile" section (under "Future discussion") as an example of a JSON-compatible profile, so link there and describe it as such instead of as a permission. Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-09-28 17:51:07 +02:00
Niels Lohmann	1e101ecac1	Add BON8 support (#2998) ... * Add BON8 support Add to_bon8/from_bon8 and input_format_t::bon8 for BON8, a binary format that uses the byte values that cannot begin a UTF-8 character as type markers, so strings need no length prefix. It is the most compact of the supported binary formats on the benchmark files. The reader is non-recursive like the other binary readers. A string ends at the first byte that cannot continue it, so the reader hands the one or two bytes it reads past a string back to the value that follows. The writer produces the canonical representation of the specification, except for NFC normalization; its output is identical to that of the reference implementation (HikoGUI) on all files of the test data. The round-trip tests need the .bon8 files of json_test_data 3.2.0. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Address review comments - Reuse detail::validate_one_utf8 to check strings in to_bon8; the error now names the first byte of the invalid sequence. - Document that to_bon8 leaves bytes in the output adapter on an exception, and that string_open is only an output of write_bon8_marker. - Explain why the pushback buffer of the BON8 reader cannot overflow. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Select the BON8 float prefix by type get_bon8_float_prefix only depends on the type of its argument, so make the type a template parameter instead of passing an unused value. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Rename a test variable that Flawfinder mistakes for read() Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Fix the BON8 CI failures - compare the float in write_bon8_float with number_float_t constants, so GCC does not warn about a float-to-double conversion - mark check_bon8_utf8's context as used when exceptions are disabled - choose the compact float prefix in a helper rather than with nested conditional operators (clang-tidy) - use auto for the cast in the BON8 integer reader (clang-tidy) - write the int32 minimum test values as long long literals (MSVC C4146) Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Amalgamate Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Read BON8 strings in bulk from contiguous input - copy the valid UTF-8 of a string in one step when the input is contiguous (twitter.json is read in 1.68 instead of 2.52 ms, jeopardy.json in 196 instead of 297 ms, close to CBOR and MessagePack) - share the new valid_utf8_prefix() with the writer's UTF-8 check, which now skips ASCII 8 bytes at a time - let the fuzzer check that contiguous and stream input give the same value or error, and test both paths in the unit tests - clarify that a second 0xFF after a string is an empty string Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Link the BON8 functions from the other binary format pages Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Name the bulk scan flag after the input, not BON8 Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Read BSON keys in bulk from contiguous input BSON keys (and array indices) are C-style strings, which were read byte by byte. For contiguous input they are now read up to their \x00-byte in one step, using the same bulk_scan flag as BON8 strings: twitter.json is read in 1.46 instead of 2.01 ms, citm_catalog.json in 2.93 instead of 3.33 ms, jeopardy.json in 182 instead of 207 ms. canada.json, whose keys are almost all one-digit array indices, takes 2 % longer. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Fix the BON8 CI failures of the bulk-read tests - skip the contiguous-versus-stream tests of BON8 strings and BSON keys when exceptions are disabled: they catch the parse errors of invalid input, and without exceptions the library aborts instead - use static_cast for the int64 test value (google-readability-casting) Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Move the explicit basic_json instantiation into its own test file Linking test-regression3_cpp20 with clang and MinGW failed with "relocation truncated to fit: IMAGE_REL_AMD64_REL32 against `.rdata'", as test-regression2 did before #5511. The explicit instantiation of basic_json<> for #4825 compiles every member function, including the BON8 reader and writer, into that object, and it was already close to the limit (2,226,104 bytes on develop, 2,234,960 with BON8; clang -O1, C++20). Give the instantiation a file of its own: unit-regression3 is now 1,594,736 bytes and unit-explicit_instantiation 1,095,064. The new file mentions JSON_HAS_CPP_17 and JSON_HAS_CPP_20 so it keeps being built for the C++17 standard the regression was about. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Convert the bytes of the BON8 test strings explicitly The str() helper constructed a std::string from a byte range, which converts each unsigned char implicitly; -fsanitize=integer reports that for bytes of 0x80 and above (ci_test_clang_sanitizer). Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-09-27 16:56:21 +02:00
Kartikey Negi	6bd106893a	Fix CBOR tag handling in cbor_tag_handler_t::store for non-binary items (#5559) ... When using cbor_tag_handler_t::store, tags 0xD8-0xDB previously assumed that the tagged item was a byte string, unconditionally attempting to parse binary data and failing on valid CBOR documents containing tags applied to integers, strings, arrays, or objects (such as self-describe tag 55799). Check whether the tagged data item is a byte string (0x40-0x5B or 0x5F). If it is a byte string, store the subtype on the binary value as before. Otherwise, iteratively process the tagged value in the driver loop using item_read so that chained tags do not consume native stack space. Part of #5316. Signed-off-by: ReturnKartikey <kartikeynegi2000.work@gmail.com>	2026-09-27 14:28:55 +02:00
Niels Lohmann	d19f7f5dce	Fix BSON conformance issue (#5185) ... * 🐛 fix BSON conformance issue Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 🐛 fix BSON conformance issue Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 🐛 reject ill-formed UTF-8 in CBOR/MessagePack/BSON text strings at decode time (#5531) from_cbor()/from_msgpack()/from_bson() copied the raw bytes of a decoded text string into the resulting json value without any UTF-8 validation, even though RFC 8949 §3.1 (CBOR) and the MessagePack/BSON specifications all require text strings to be valid UTF-8. Malformed input only failed later, if the value was dump()'d, with a type_error.316 - so the allow_exceptions=false pattern used specifically to get a discarded sentinel instead of an exception did not discard this category of malformed input, unlike every other kind of malformed binary input this library rejects at decode time (see #5529). Fix this at the single choke point shared by BSON/CBOR/MessagePack/UBJSON string reads, binary_reader::get_string(): validate the bytes with the UTF-8 DFA right after they are read, and report failures the same way as every other binary_reader error (parse_error.113), so allow_exceptions and strict discarding behave consistently. get_binary()/binary blob reads are untouched and still accept arbitrary bytes, since only text strings are required to be UTF-8. There were two independent implementations of a UTF-8 validator: the lexer's streaming scanner, and the serializer's Hoehrmann DFA used by dump_escaped_impl(). Rather than write a third, the serializer's decode() function, its utf8d table and the UTF8_ACCEPT/UTF8_REJECT constants are extracted into detail/string_utils.hpp (a low-level header already included before both detail/input/ and detail/output/), alongside a new is_valid_utf8() helper built on the same decode() step. serializer.hpp's dump_escaped_impl() now calls the shared decode(), so there is exactly one UTF-8 validator in the codebase; dump()'s exact type_error.316 messages and byte-index reporting are unchanged (see the added regression-guard test in unit-serialization.cpp). Claude-Session: https://claude.ai/code/session_01N4RQ1Ahan5YAGbnAQGjZTY Signed-off-by: Niels Lohmann <mail@nlohmann.me> Co-authored-by: Claude Sonnet 5 <noreply@anthropic.com> * ⚡ validate only newly read bytes of binary-format strings get_string() validated the whole result after each call, but get_bytes() appends to it and CBOR indefinite-length strings collect all chunks in the same result, so every chunk re-validated everything read before it. An input of many small chunks took quadratic time (80000 one-byte chunks, 160 KB of input, took about 7 seconds). Only the newly read bytes are validated now, which also matches RFC 8949's requirement that every chunk is valid UTF-8 on its own. Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me> Co-authored-by: Claude Sonnet 5 <noreply@anthropic.com>	2026-09-25 20:45:28 +02:00
Niels Lohmann	c72f37a40d	Support custom object/array types and improve template parameter handling (#5443) ... * docs: document the implicit requirements on basic_json's template parameters The requirements that basic_json places on its eleven template parameters were only implied by how the library uses the resulting object_t, array_t, string_t, etc. Consumers had to discover them by trial and error. Add "Template Parameter Requirements" collecting them, split into what is always required and what is only required when a particular part of the API is instantiated. Notable findings that were previously undocumented: - ObjectType must provide a key_compare member type (actual_object_comparator names object_t::key_compare in both arms of a std::conditional), and its third template parameter is used as a comparator, so std::unordered_map cannot be used without a wrapper. - ArrayType must provide capacity() -- push_back(), emplace_back(), operator+=(), and operator[](size_type) call it unconditionally -- and needs random-access iterators, so std::deque and std::list do not work. - StringType needs contiguous, null-terminated data(), a one-byte value_type, and either assignability from std::to_string or an ADL int_to_string(). - NumberFloatType must be float, double, or long double for parsing and serialization; the integer types must satisfy std::is_integral. - AllocatorType must be stateless, support incomplete types, and use plain pointers. - BooleanType and the number types are union members and must be trivial. Link the new page from the basic_json overview, the types feature page, and the individual type alias pages, and correct the container examples given for ObjectType (std::unordered_map) and ArrayType (std::list), which do not work. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_018hxZxz8svM54c6ATEvXp5E Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Fix object_comparator_t for object types without key_compare detail::actual_object_comparator selected between object_t::key_compare and default_object_comparator_t with std::conditional. Both type arguments of std::conditional are named eagerly, so object_t::key_compare had to exist regardless of the condition, and the has_key_compare guard added in 3.11.0 never took effect: any ObjectType without a key_compare member type failed to compile while instantiating basic_json itself. Use detected_or_t instead, which resolves through a SFINAE partial specialization and only names object_t::key_compare when it exists. The selected type is unchanged for every object type that compiled before, so object_comparator_t -- a public member type -- keeps its meaning and ABI. has_key_compare had no other users and is removed. Add a regression test using an adapter around std::unordered_map, which has no key_compare; it fails to compile without this change. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_018hxZxz8svM54c6ATEvXp5E Signed-off-by: Niels Lohmann <mail@nlohmann.me> * docs: list the types that are known to work for each template parameter Follow up on the template parameter requirements page: state, for every template parameter, which concrete types work and where they stop working. Each entry was verified by compiling and running a common workload (DOM access, dump, parse, CBOR/MessagePack round-trip, flatten, hash) against that instantiation. Findings worth calling out: - ObjectType no longer needs a key_compare member type, so the std::unordered_map adapter only has to restore the template argument order. A hash-ordered ObjectType works everywhere except unflatten(), which reconstructs an array only when it meets the reference token 0 before the other indices. - ArrayType: std::deque works when wrapped to add capacity(); std::list does not. - StringType: std::pmr::string and std::basic_string with a custom allocator compile for the DOM, dump, and parse, but not for the binary readers, flatten, or diff, because the library assigns std::string values to string_t and int_to_string cannot be overloaded for a type in namespace std. - NumberFloatType: long double works for dump and parse but not for the binary formats, which have no encoding for it. - BinaryType: std::vector<std::byte> supports assignment, get, and the binary formats, but neither dump nor std::hash<basic_json>. Also record the object_comparator_t fix in its version history. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_018hxZxz8svM54c6ATEvXp5E Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Fix unflatten and binary dumping for non-default configurations unflatten() decided between array and object by looking at the first reference token it happened to see for a node: it started an array only when that token was 0. With a sorted object type the token 0 always arrives first, so the result was correct by accident; with an object type whose iteration order is unspecified, {"/c/2":3,"/c/1":2,"/c/0":1} unflattened to an object with the keys "0", "1", and "2" instead of an array. Collect the pointer prefixes that have a reference token 0 among their children before building the result, and let get_and_create() consult that set. The outcome is now independent of the iteration order and matches, for every input, what a sorted object type produced before: a value is restored as an array if and only if one of its keys is 0. Iterating the flattened object in a different order would have been simpler, but it would have changed the key order of the result for insertion-ordered object types. The serializer, std::hash, and the UBJSON writer converted the elements of a binary value to an integer implicitly, which does not compile for a BinaryType whose value type is std::byte, and which made dump() write the bytes of a signed value type as negative numbers. Convert to std::uint8_t explicitly in all three places, so every byte type dumps as 0..255. The default std::vector<std::uint8_t> configuration is unaffected. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_018hxZxz8svM54c6ATEvXp5E Signed-off-by: Niels Lohmann <mail@nlohmann.me> * docs: note which Abseil containers can be used as template arguments Checked against Abseil release 20250127.0 with the same workload as the other entries on the page (DOM access, dump, parse, CBOR/MessagePack/UBJSON round-trip, flatten, hash), with and without JSON_DIAGNOSTICS. absl::flat_hash_map and absl::node_hash_map work as ObjectType through an adapter that restores the template argument order and makes erase(iterator) return the following iterator, which Abseil's returns as void. The page now carries that adapter, and notes that absl::flat_hash_map does not keep references to the mapped values valid across insertions while absl::node_hash_map does. Both have a capacity() member, so JSON_DIAGNOSTICS already refreshes the parent pointers conservatively for them. absl::btree_map and absl::InlinedVector cannot be used at all: object_t and array_t are formed while basic_json is still incomplete, and both inspect their value type at class scope. std::map and std::vector are required by the standard to tolerate this, third-party containers generally are not, so the page states the constraint on its own rather than only per container. absl::InlinedVector does work as BinaryType, where it is instantiated with a complete type. absl::FixedArray and absl::Cord are not usable. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_018hxZxz8svM54c6ATEvXp5E Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Relax the ArrayType and ObjectType requirements Two requirements forced users of otherwise suitable containers to write a wrapper, and neither was load-bearing. array_t::capacity() was read in push_back(), emplace_back(), operator+=(), and operator[](size_type), but set_parent() only looks at the value under JSON_DIAGNOSTICS; without diagnostics it was computed and discarded. Read it through array_capacity(), which reports unknown_size() when diagnostics are off or when the array type has no capacity() at all, and treat an unknown capacity as "the elements may have moved" so the parent pointers are refreshed conservatively. std::deque now works as ArrayType, in both builds, and capacity() is no longer named at all in a default build. Since the capacity is now only meaningful for array insertions, it moves out of set_parent() into set_parent_after_array_insert(). basic_json::erase(iterator) assigned the object's erase() return value, which requires the container to return the following iterator. Abseil's hash maps return void to avoid computing a successor the caller may not need. Detect that and compute the successor before erasing; containers that return an iterator, including the vector-backed ordered_map where a precomputed successor would be wrong, keep the existing path. Together these leave an Abseil hash map needing only an alias that restores the template argument order, and no adapter at all for std::deque. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_018hxZxz8svM54c6ATEvXp5E Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Do not require string_t to be convertible from std::string Three places built a std::string and handed it to something expecting a string_t: the UBJSON high-precision number reader, which every binary reader instantiates, and the BSON writer's array element size calculation and write. That silently required string_t to be implicitly convertible from std::string, which std::string itself and types with a string_view conversion satisfy, but many string types do not. Construct the string_t explicitly from the data and size, which the requirements already cover. This makes boost::container::string, eastl::string, std::pmr::string, and std::basic_string with a custom allocator work as StringType, none of which could previously be used with any binary format. Add binary format coverage to the alt_string test, which had none, including a UBJSON high-precision number -- the case that goes through the reader path. BSON stays uncovered there: it additionally needs string_t::find(value_type), which alt_string does not provide. Also record which containers from Boost, Abseil, and EASTL work for each template parameter, and correct two claims: std::pmr::string is usable after this change, and tsl::ordered_map is not usable at all, because its iterators expose the mapped value as const while basic_json modifies it in place. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * docs: record compatibility for the common header-only hash maps ankerl::unordered_dense (map and segmented_map), phmap (flat_hash_map and node_hash_map), and robin_hood::unordered_flat_map all work as ObjectType through the same adapter as Abseil's and Boost's hash maps, which only has to restore the template argument order. phmap::btree_map and robin_hood::unordered_node_map do not: like the other btree containers they require a complete value type. Note that none of these hash maps defines key_compare, so every one of them depends on object_comparator_t falling back to default_object_comparator_t. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * docs: record Folly and the remaining vector replacements Folly works, with the caveat that its headers need C++20: folly::fbstring as StringType, folly::fbvector and folly::small_vector as ArrayType, folly::fbvector<std::uint8_t> as BinaryType, and folly::F14NodeMap as ObjectType through the usual argument-order adapter. folly::F14FastMap is the exception and requires a complete value type. For ArrayType, boost::container::devector, boost::container::static_vector (within its fixed capacity), and std::pmr::vector work as well. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * docs: cover fifo_map, gtl, folly::sorted_vector_map, and Qt nlohmann::fifo_map works through the adapter that has always been documented for it, and preserves the insertion order. Restore its mention in the object order page, which was dropped together with the tsl::ordered_map one: unlike ordered_map it keeps a lookup index, so it is the insertion-ordered option without the quadratic cost. gtl::flat_hash_map and folly::sorted_vector_map work as well, the latter through an alias that drops the allocator, whose value type it disagrees on. gtl::btree_map does not, for the same reason as the other btree containers. None of the Qt containers can be used, each for its own reason: QMap has no value_type, QHash iterators yield the mapped value rather than a pair, QList has no max_size(), QByteArray spells empty() as isEmpty(), and QString is UTF-16. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * docs: qualify the std::pmr::string support claim Listing std::pmr::string as fully supported was an overclaim: it was only ever checked with the default memory resource, which is not what PMR is for. basic_json cannot be given an allocator or a memory resource, so a pmr string inside a value always allocates from std::pmr::get_default_resource(), and assigning an arena-backed string into a value silently drops its resource, because polymorphic_allocator does not propagate on copy construction. Passing polymorphic_allocator as AllocatorType does not compile either. Only the process-global set_default_resource() redirects these allocations. Say so, and separate the row from std::basic_string with a custom stateless allocator, which is unaffected. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * docs: remove a duplicated StringType compatibility section The StringType section carried two 'Compatible types' tables and two copies of the reference-implementation tip. The second table was a stale copy from before the binary format string fixes and still listed std::pmr::string and std::basic_string with a custom allocator as unusable, contradicting the corrected table a few lines above it, and it dragged along the old explanation that blamed int_to_string. Drop the stale copy and put the surviving table before the notes, so the 'see below' in the std::pmr::string row points forwards. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * docs: correct the template parameter requirements after independent verification Every claim on the page was re-checked by compiling and running it, including the rows that say a type cannot be used, which were checked to fail for the documented reason and not merely to fail. Twenty-four claims were wrong. The most consequential: the incomplete-type constraint applies to ObjectType only. object_t is instantiated inside the class definition, because it is probed for key_compare; array_t is only named there and is not instantiated until basic_json is complete. So eastl::vector, QList and QVector are not excluded by incomplete types at all -- they simply have no max_size() -- and absl::InlinedVector is excluded for a subtler reason of its own. Further corrections: ObjectType does not need erase(key), which has a fallback, but does need at(key) for UBJSON output; only == and < are used, or == and <=> under C++20, not all six; the documented adapter does not fit ankerl or robin_hood. ArrayType needs no initializer-list insert, and value_type, the (count, value) constructor and swappability are per-function, not always. BinaryType needs a range insert for CBOR indefinite-length byte strings and does not need push_back. StringType needs append(const StringType&) unconditionally, and does not need operator!= or operator== against const char*; empty(), resize(n) and reserve(n) are per-subsystem; int_to_string is needed by diff, items and std::hash rather than by JSON Pointer or flatten. BooleanType must be implicitly convertible from bool, and JSONSerializer's second parameter need not carry a default. std::pmr::string was wrong in the other direction this time: a moved-in string does keep its memory resource, and later growth allocates from it. Only copies land on the default resource. Five requirement violations are not caught at compile time rather than the two the page claimed; they are now listed together up front. Split every compatibility table into what works and what does not, as the reasons in the second half are the useful part. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Reduce the string_t and array_t members the library requires Several members were required only because of how the library happened to be written, not because the functionality needs them. Dropping them widens the set of usable string and array types, and one of them was also a performance problem. string_t: - c_str() is gone. Every call site already knew the length and passed it along, so data() is enough. The one place that did not, the diagnostics path in exceptions.hpp, now builds the token from data() and size(), which also stops it from truncating keys that contain a null byte. - back() is gone; the serializer indexes the last character instead. - find(str, pos), replace(), and substr() are gone. escape() and unescape() rebuilt the string with one replace() per escaped character, which moves the tail every time: escaping a string of n characters that all need escaping cost O(n^2). Both now scan with find_first_of() -- a member the pointer parser already required -- and append whole runs, so the common case is one search and one copy. Escaping 64000 tildes drops from 717 ms to 20 ms; a string with nothing to escape gets faster too (8.4 ms to 5.8 ms), because the scan is still a single memchr per pass. json_pointer::split() takes its reference tokens with the (const char*, size_type) constructor rather than substr(). - json_pointer::to_string() accumulates with concat<string_t> instead of letting concat default to std::string and converting afterwards, so streaming a json_pointer no longer requires string_t to be assignable from a std::string. array_t: - at(size_type) is gone. basic_json::at(size_type) checked the index by calling array_t::at() and translating std::out_of_range, which also required the array type to throw that exact exception. It now compares against size() and uses operator[]. The thrown exception, its message, and the behaviour under JSON_NOEXCEPTION are unchanged. The BSON writer wrote the terminating null byte out of the string's own buffer (size() + 1). It now writes the byte itself, so string_t::data() need not be null-terminated for to_bson(). The tests pin the reduced API: alt_string loses the five dropped members and gains coverage of the escaping paths, and a std::vector whose at() is hidden is used as an ArrayType. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * docs: record the reduced string_t and array_t requirements Drop c_str(), back(), find(str, pos), replace(), and substr() from the StringType requirements and at(size_type) from the ArrayType ones, and note the string assignment the JSON pointer code performs. Streaming a json_pointer no longer needs assignability from a std::string. Add the non-null-terminated data() to the list of violations that are not diagnosed at compile time -- it was described in the StringType section but missing from the summary at the top -- and correct the QString row, which no longer fails for the c_str() it lacks. JSON_CATCH_USER no longer wraps a catch of std::out_of_range: the last one went away with array_t::at(). Describe what the library actually catches. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Use character literals for the signed BinaryType test MSVC rejects char(0xFF) with C4310 (cast truncates constant value), which the Windows workflow treats as an error. The character literals carry the same byte values without a narrowing cast. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Do not instantiate a hash map with an incomplete basic_json in the tests object_t is probed for key_compare inside the definition of basic_json, so it is instantiated while basic_json is still incomplete. Whether a hash map survives that depends on the standard library: libstdc++ 9 needs the size of the mapped type to instantiate std::unordered_map's node type and rejects the adapter, which broke the GCC 9 builds. The test now derives its no-key_compare object type from std::map -- which does cope -- and shadows the inherited key_compare member type with an entity that is not a type, so the library's probe finds none, exactly as for a hash map. The unflatten() order-independence checks in unit-json_pointer already cover the behaviour that the unordered object type was there for. The limitation is documented for std::unordered_map. Also address two Clang-Tidy findings the earlier commits introduced: erase_from_object() declares its iterator with auto, and at(size_type) checks the type first and then falls through to the return instead of throwing from an else branch. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Keep diagnostic key paths null-terminated Building the token from data() and size() kept an embedded null byte in the key, and since what() hands out a C string, that truncated the whole message rather than just the key: to_bson() on a key containing U+0000 reported "[json.exception.out_of_range.409] (/en" instead of the full explanation. This broke test-bson under JSON_DIAGNOSTICS. Constructing from data() alone stops at the first null byte, which is what c_str() did before, so the message is unchanged -- without requiring string_t to provide c_str(). Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Do not parse the value in the array-at() test JSON_DIAGNOSTIC_POSITIONS adds the byte range of the value to the exception message, which a parsed value has and an in-memory one does not, so the two message checks failed in that configuration. Build the array in memory instead of parsing it; the test is about at(size_type) not needing array_t::at(), and the byte range is beside the point. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Move the custom BinaryType tests into their own translation unit The two sections added to unit-regression2.cpp brought a third full basic_json instantiation into a translation unit that was already large. With Clang on MinGW that pushed the object over the reach of a 32-bit relocation and test-regression2_cpp20.exe failed to link: relocation truncated to fit: IMAGE_REL_AMD64_REL32 against `.rdata' unit-regression2.cpp is restored to exactly what it was before, and the coverage moves to unit-custom-binary-type.cpp, next to the object and array type tests it belongs with. The signed value type is now also covered in C++11, where std::byte is not available. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Do not require the container iterators to be nothrow move constructible iter_impl declared its defaulted move operations noexcept. The exception specification a defaulted function gets implicitly follows from its members, here internal_iterator, which holds the object and array iterators. libstdc++ gives std::deque's iterator a user-provided copy constructor without noexcept before version 11, so the implicit specification is noexcept(false) and does not match the declared one. That deletes the function -- and with g++ 4.8, which predates CWG 1778, it is an error outright: error: function 'iter_impl<basic_json<std::map, std::deque> >::iter_impl( iter_impl&&)' defaulted on its first declaration with an exception-specification that differs from the implicit declaration So std::deque, which this branch documents as a usable array type, could not be used with an older standard library. Leaving the specification to be computed cannot mismatch; iteration_proxy_value already spells out the same condition next door. The default configuration is unaffected: json::iterator, json::const_iterator and ordered_json::iterator stay nothrow move constructible and move assignable, which the test now checks so it cannot regress unnoticed. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Address two Clang-Tidy findings the custom container tests exposed Both come from instantiating basic_json with containers other than the default ones, and neither shows up with the Clang-Tidy version available outside CI: - insert(const_iterator, basic_json&&) forwards its by-value iterator to the const-reference overload. performance-unnecessary-value-param asks for the copy to be a move; it only fires for an iterator that is not trivially copyable, as std::deque's is not. The NOLINT on the function does not cover it, because the finding is reported where the parameter is used rather than where it is declared. Move it, which is what the check asks for and is a (very small) improvement in its own right. - cppcoreguidelines-use-enum-class rejects the unnamed enum that shadowed the inherited key_compare member type. An enum class would not do, since it declares a type of that name and the probe would find it again; a member function declaration hides the name just as well. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Assert the iterators' exception specification relative to the container The test pinned that nlohmann::json's iterators stay nothrow movable after iter_impl's defaulted move operations lost their declared noexcept. That is not a property of the library, though: the exception specification is now computed from the container iterators, so it holds only for standard library implementations whose iterators are themselves nothrow movable. MSVC's checked iterators before VS2017 are not -- _Iterator_base12 registers the iterator with the container's debug proxy in a copy constructor that carries no noexcept -- so the assertions fail on a Visual Studio 2015 debug build, which is the one debug configuration in the AppVeyor matrix and has no counterpart in the GitHub Actions matrix. Assert what the change actually guarantees instead: the iterators are nothrow movable exactly when the object and array iterators they are built from are. That still pins the default configuration against a silent regression, and it is true whatever the standard library provides. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Detect a void-returning erase() through a named trait erase_from_object() distinguished its two overloads with a decltype of a member call written inline in a default template argument. Every other detection in the library goes through the detector machinery in detected.hpp instead -- has_erase_with_key_type is the same question about the same member function -- and the inline form is the one shape older compilers are least reliable about. Express it the same way: detect_erase_with_iterator plus is_detected_exact, both of which the library already relies on elsewhere. No behaviour changes. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Give the custom container types only the constructors the library uses The three container types in the new tests inherited every constructor of their base with using Base::Base. That asks for more than the test needs: the library builds an object or an array by default construction, by copy or move, and -- when converting between two basic_json types or from an initializer list -- from an iterator range. Declaring those directly makes the requirement visible in the test, and keeps object types out of a corner where a compiler has to declare std::map's whole constructor set for a derived class while basic_json is still incomplete. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Temporarily disable the new custom container tests AppVeyor is the only CI that builds MSVC 2015 and 2017, and it has now rejected three heads of this branch. Its build log is not reachable from where this is being worked on, so the verdict is a single bit and the cause has to be narrowed down by bisection. Everything else stays: the library changes, the reduced alt_string, and the unflatten() tests. If AppVeyor passes with these three translation units disabled, the cause is one of the six basic_json instantiations they add; if it fails, it is in the library. Either way this commit is reverted. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Guard the disabled tests with a macro rather than #if 0 Clang-Tidy's readability-avoid-unconditional-preprocessor-if rejects a literal #if 0. Use a macro that is never defined instead, which the check does not look at. Still temporary, and reverted together with the previous commit. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Re-enable the array and binary container tests AppVeyor passed with all three new translation units disabled, so the library changes, the reduced alt_string, and the unflatten() tests are fine on MSVC 2015 and 2017; the cause is one of the six basic_json instantiations the new tests add. Bring back two of the three. If AppVeyor passes again, the cause is in unit-custom-object-type.cpp, which is the one still disabled; if it fails, it is in one of these two and needs one more split. Still temporary. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Diagnose two silently violated template parameter requirements Both were on the list of requirements that are not caught at compile time and corrupt values rather than failing, and both are a plain size comparison: - A BinaryType whose value_type is wider than one byte, which the readers and writers reinterpret as raw bytes anyway. - A NumberUnsignedType too narrow to hold the absolute value of every NumberIntegerType value, which makes basic_json(INT64_MIN).dump() yield -0 for std::int64_t with std::uint32_t. Neither static_assert rejects a configuration that worked before: both only fire where the result was already wrong. Also add the two comments the review asked for, in write_bson_string() and calc_bson_array_size(), matching the ones their counterparts already carry. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Align the template parameter tables and record what is now diagnosed Every table in the page is reformatted so each column is exactly as wide as its widest cell, which is what the review asked for in a dozen places: the separator rows that ran two dashes long, the stray spaces, and the columns padded well past their content. The row listing six containers that require a complete mapped type is split in two so that one cell no longer sets the width of the whole table. Content changes: NumberUnsignedType is described as any unsigned integer type at least as wide as NumberIntegerType rather than any unsigned integer type; the two requirements that are now static_asserts move out of the list of violations that are not caught at compile time; and the two places that require a non-const operator[] say why data() will not do (std::string has no non-const data() before C++17). Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Bisect the other way: only the object container tests The previous head touched only docs/, which AppVeyor's only_commits filter skips, so it produced no build and no status at all -- the pull request looked green without ever having been built on MSVC 2015 or 2017. Swap the guards instead of repeating that step: unit-custom-object-type.cpp is enabled and the array and binary translation units are disabled. AppVeyor already passed with all three disabled, so a failure here pins the cause on no_key_compare_json or void_erase_json, and a pass pins it on the array or binary file. Still temporary. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Split the two object types apart AppVeyor failed with only unit-custom-object-type.cpp enabled and passed with all three new translation units disabled, so the cause is one of the two object types in this file and not the array or binary ones. Guard out void_erase_map and leave no_key_compare_map, which separates the two constructs under suspicion: shadowing the inherited key_compare member type with an entity that is not a type, and hiding the inherited erase with a void-returning overload. A failure here points at the first, a pass at the second. Still temporary. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Build the no-key_compare object type by composition, not inheritance The "object type without key_compare" test failed on AppVeyor's MSVC 2017 jobs (/std:c++17): its no_key_compare_map derived publicly from std::map and shadowed the inherited key_compare type with a same-named member function, relying on ordinary member hiding to make key_compare unreachable as a type for the library's detection trait. MSVC 2017 does not honor that hiding for a typename-qualified lookup performed from outside the class and still resolves key_compare to the base's comparator type, so object_comparator_t incorrectly picked it up instead of falling back to default_object_comparator_t. Wrapping a std::map by composition instead removes the base class entirely, so there is no key_compare to find under any lookup rule, on any compiler. Also drops the now-unneeded JSON_BISECT_CUSTOM_CONTAINER_TESTS guard left over from narrowing this down: the void_erase_map test in the same file was never the cause and is re-enabled unconditionally. Verified locally with clang++ and g++ under C++17 and C++20. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Re-enable the array and binary custom-container tests unit-custom-array-type.cpp and unit-custom-binary-type.cpp were still guarded behind JSON_BISECT_CUSTOM_CONTAINER_TESTS from bisecting the AppVeyor failure fixed in 7c39f3227, which was unrelated to either file. The macro was never defined, so none of these tests actually ran in CI. Verified locally with clang++ and g++ under C++17 and C++20 before removing the guards. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Fix indentation of custom_object_type per astyle The one-line function bodies in the composition-based no_key_compare_map (7c39f3227) do not match the project's Allman brace style, which the ci_test_amalgamation job enforces with astyle. Reformatted with the pinned astyle 3.4.13; no functional change. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * docs: add compiled reference implementations for the container template parameters Each of ObjectType, ArrayType, StringType, and BinaryType now links to a minimal, self-contained header (docs/mkdocs/docs/examples/custom_*_type.hpp) that wraps the corresponding standard container by composition and satisfies every "Always required" member listed on that page. Unlike the prose requirement lists, these are real code: each header has a companion .cpp that instantiates a basic_json specialization with it and is compiled and run by the existing ci_test_examples check (docs/Makefile's check_output_portable), so the reference implementations cannot silently drift from what the library actually requires. The .output files were generated with that same target. StringType's existing pointer to tests/src/unit-alt-string.cpp's alt_string is kept alongside the new header as a more thorough, battle-tested example. Verified locally: astyle (pinned 3.4.13, project .astylerc) on the new files; clang++/g++ under C++11/17/20 for each example against the amalgamated header; `make check_output_portable` in docs/; `mkdocs build --strict` and scripts/check_structure.py for the page itself. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Declare no_key_compare_map's accessors noexcept The GCC C++20 job builds with -Wnoexcept and -Werror, and the standard library takes noexcept(c.begin()) and noexcept(c.end()) in ranges_base.h and range_access.h. Forwarding to std::map without repeating its noexcept made those expressions false, which the warning reports as an error: error: noexcept-expression evaluates to 'false' because of a call to no_key_compare_map<...>::begin() [-Werror=noexcept] note: but ... does not throw; perhaps it should be declared 'noexcept' Give the accessors the exception specification of what they forward to. std::map declares begin, end, cbegin, cend, empty, size, max_size, and clear noexcept, so the wrapper does too. swap is left alone: std::map's is only conditionally noexcept, and nothing asks for it. void_erase_map is unaffected because it still derives from std::map and inherits accessors that already carry the specification. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_018hxZxz8svM54c6ATEvXp5E Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Write out what the defaulted constructor of no_key_compare_map implied ci_test_gcc builds with -Weffc++, which asks for data to be initialized in a member initialization list; a defaulted default constructor does not do that: error: 'no_key_compare_map<...>::data' should be initialized in the member initialization list [-Werror=effc++] Writing the constructor out satisfies that but drops the exception specification the defaulted one carried, which -Wnoexcept then objects to where the standard library takes noexcept(construct(...)). Declare it the way the defaulted constructor was: noexcept when the wrapped map's default constructor is. This is the cost of composition -- inheritance carried std::map's exception specifications and initialization for free, and forwarding by hand has to restate them. Checked with the repository's own GCC warning set from cmake/gcc_flags.cmake, all 346 flags, at C++11, C++17 and C++20: no diagnostics for this file, nor for the two custom container translation units that were disabled while the MSVC failure was narrowed down and are built again now. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_018hxZxz8svM54c6ATEvXp5E Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Mark no_key_compare_map::swap noexcept Clang-Tidy rejects a swap that is not: error: swap functions should be marked noexcept [cppcoreguidelines-noexcept-swap,performance-noexcept-swap] It was left unmarked on the grounds that std::map::swap is only conditionally noexcept, so an unconditional promise would be wrong for a comparator or allocator that can throw while swapping. Both concerns are met by taking the specification from the wrapped map rather than asserting one: noexcept(noexcept(data.swap(other.data))). Clang-Tidy accepts that, and no NOLINT is needed. Last in the series of specifications that inheritance used to supply and composition has to write out by hand. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_018hxZxz8svM54c6ATEvXp5E Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me> Co-authored-by: Claude Opus 5 <noreply@anthropic.com>	2026-09-15 20:46:37 +02:00
Niels Lohmann	aa391dc0a5	Fix two develop CI regressions: dump() nodiscard warning and binary-reader const-correctness (#5520) ... * Discard dump()'s [[nodiscard]] return value in an exception-only check CHECK_THROWS_WITH_AS(j.dump(), ...) called dump() only to trigger and catch the exception, but never used the return value. dump() is warn_unused_result, so GCC's pedantic build (-Werror --all-warnings) rejected it as -Werror=unused-result, breaking ci_test_gcc. Wrapped in utils::ignore_return_value(), matching every other such call in this file. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Mark container_frame top as const in CBOR/UBJSON readers clang-tidy's misc-const-correctness flagged these on PR #5520's CI: the BSON sibling copy was already const, but these two were left mutable even though only container_stack.back().remaining is ever written. Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-09-11 17:55:46 +02:00
Niels Lohmann	0452641c18	Read BSON documents without recursing per nesting level (#5508) ... * Read BSON documents without recursing per nesting level An embedded document (record type 0x03) or array (0x04) was read by calling back into the document reader, which read its element list, which called the element reader again for the next embedded one. The native call stack therefore grew with the nesting depth of the input, and about seven bytes buy a level, so a document of a few hundred kilobytes crashes the process (#5104). This is the last of the four binary formats to still do that. Apply the same shape as the other three: open_bson_document() reads the size prefix and opens the document, parse_bson_element_internal() calls it for both record types instead of recursing, and parse_bson_internal() loops over the element list of whichever document is innermost, closing it when its terminator is reached and resuming the one below. check_bson_document_size() is unchanged, and so is when it runs: a document is still measured from the byte before its size prefix to the byte after its terminator, and still reported before the end event. The frame carries those two values, which is what a per-document check needs once the reads are interleaved rather than nested. Nothing else about the element reader changes. unit-bson passes unchanged. Round trips through to_bson of nested objects, arrays, arrays of objects and mixed nesting are identical to the previous commit, as are the errors for a truncated document, an unsupported record type, a negative size and a size that does not match, including their byte offsets. A 30,000-level document built by to_bson is now read to completion where it used to crash. Note for sequencing: #5185 changes parse_bson_internal(), the element list and the array reader, which are the functions this commit restructures. It should land first; this commit then keeps its checks and moves them onto the loop. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Make parse_bson_internal's end-of-document top a copy, not a reference Same issue as the CBOR and UBJSON/BJData readers: top aliased container_stack.back() and was read (top.is_object) right after container_stack.pop_back() ended its lifetime. A copy stays valid regardless of what happens to the stack; nothing here mutates the live entry, so no field needs to go through container_stack.back() directly. Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-09-11 08:34:45 +02:00
Niels Lohmann	a14619b354	Read UBJSON and BJData containers without recursing per nesting level (#5507) ... * Read UBJSON and BJData containers without recursing per nesting level get_ubjson_array() and get_ubjson_object() read their elements by calling back into the value reader, which called them again for a nested container, so the native call stack grew with the nesting depth of the input. '[' alone opens a container, so half a million of them crashes the process before the input runs out (#5104). The optimized forms reach the same path through a size or type annotation, and in plain UBJSON '[' and '{' are permitted as the type of an optimized container, so "[$[#i\x01" repeated nests just as deeply at six bytes a level. Both readers now only open their container, and parse_ubjson_internal() loops: it closes the containers that have ended, claims the next element of the innermost one, reads its key when it is an object, and works out the marker of the value to read next. That last part is where the formats differ, and the loop follows what the four element loops used to do: - a sized, typed container gives its elements no marker of their own - a sized, untyped container reads one for each element - a container that ends at a marker has the byte already, from the test against ']' or '}'; for an object it is the first byte of the key The ND-array wrapper and the 'B' binary shortcut stay as they are. Both read a complete value rather than opening a container, and their elements are always scalars: BJData does not permit '[' or '{' as an optimized type, which is also why only plain UBJSON needed the type-marker case above. A container of no-ops keeps its behaviour of holding no elements while still announcing its declared size to the SAX parser, by opening it and then setting its count to zero. unit-ubjson and unit-bjdata pass unchanged, 1.39 million assertions between them, and a behaviour comparison against the previous commit over every container form -- sized, unsized, typed, untyped, empty, no-op, ND-array, binary, and the forms nested inside one another -- gives identical values, error codes, messages and byte offsets. 500,000 levels of each vector now report a parse error instead of crashing, and a well-formed 100,000-level value is read to completion. The driver costs about 3 % on parsing 60,000 small objects and one array of a million integers, for the reason given in the previous commit; reading the frame once per element rather than per branch halved what it cost before. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Make the UBJSON/BJData advance loop's top a copy, not a reference Same issue as the CBOR reader: top aliased container_stack.back() and was read (top.is_object) right after container_stack.pop_back() ended its lifetime. A copy stays valid regardless of what happens to the stack; the one place that mutates the live entry (--top.remaining) now goes through container_stack.back() directly. Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-09-11 08:34:44 +02:00
Niels Lohmann	91ab3e81f5	Read CBOR containers and tags without recursing per nesting level (#5506) ... * Read CBOR containers and tags without recursing per nesting level get_cbor_array() and get_cbor_object() read their elements by calling back into the value reader, which called them again for a nested container, and a tag was handled by reading the tagged value the same way. All three cost native stack, and all three cost a single byte to encode: 0x9F opens an indefinite-length array, 0x81 a one-element array, and 0xC2 is a tag. Half a million of any of them crashes the process before the input runs out (#5104). Apply the shape the MessagePack reader already uses: the open containers live on the heap stack, parse_cbor_value() reads a single value and only opens a container rather than reading it to its end, and parse_cbor_internal() loops, resuming the innermost container after each element. Two things are specific to CBOR. An indefinite-length container ends at a break marker rather than at a count, and testing for that marker consumes a byte which is the first byte of the next element when it is not one; the frame's count is npos for those, and the driver tracks whether the next value starts at a fresh byte. And a tag is not a value of its own: instead of reading the tagged value by recursing, the value reader reports that a tag was read and the driver reads on, so a chain of tags costs no stack at all. The switch that decodes a value is unchanged apart from the twelve container cases and the two tag sites. Verified against the previous commit over definite and indefinite arrays and maps, all four counted forms, empty containers, nesting of the forms inside each other, truncated inputs, and all three tag handlers: identical values, error codes, messages and byte offsets. 500,000 levels of each of the three vectors now report parse_error.110 instead of crashing, and a well-formed 200,000-level value is read to completion. On performance: the driver does per element what a counted loop used to do per container, and CBOR pays for it more than MessagePack because the value reader also has to be told whether to fetch a byte. Parsing 60,000 small objects and one array of a million integers is 3 to 4 % slower than the recursive reader, measured over five alternating runs. Against develop the same two inputs are about 44 % faster, because the entry point no longer copies the value it parsed; the earlier commit in this series is what pays for that. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Make parse_cbor_internal's top a copy so it survives pop_back() top aliased container_stack.back(), and was still read (top.is_object) right after container_stack.pop_back() destroyed the element it aliased. Nothing currently reorders those two lines, but the comment claiming the reference's lifetime was already fine only accounted for reallocation from a push, not this. A trivially-copyable container_frame makes top a copy instead, so reads of it stay valid regardless of what happens to the stack; the one place that mutates the live entry now does so through container_stack.back() directly rather than through top. Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-09-11 08:34:44 +02:00
Niels Lohmann	0dd8ca9023	Read MessagePack containers without recursing per nesting level (#5505) ... get_msgpack_array() and get_msgpack_object() read their elements by calling back into parse_msgpack_internal(), which calls them again for a nested container. The native call stack therefore grew with the nesting depth of the input, and each level costs only one byte to encode: 0x91 is a one-element array, so a few hundred thousand of them crash the process before any of the input is rejected (#5104). Keep the open containers on a heap stack instead, the way parser::sax_parse_internal() has always done for JSON text. A frame records how many elements are left and whether to close with end_object() or end_array(); parse_msgpack_value() reads a single value and, for a container, only opens it; and parse_msgpack_internal() loops, resuming the innermost container after each element and closing it when its count runs out. Whether the value that was begun is complete is answered by the stack being empty, so no separate bookkeeping is needed. The switch that decodes a value is untouched apart from the six container cases, which now call enter_container() rather than a reader that loops. That keeps this diff to the control flow and leaves the decoding of every other type byte-identical. enter_container() is the only place a binary reader emits start_object() or start_array(), so a check that rejects a container can be added there once and is guaranteed to run before the start event. The frame type and the stack are shared, ready for the other three formats. Verified against develop over empty, nested, counted (array 16/32, map 16/32) and truncated inputs: identical values, error codes, messages and byte offsets. 300,000 levels now report parse_error.110 instead of crashing, and a well-formed 300,000-level value is read to completion through the SAX interface, where develop crashes. Reading such a value into a basic_json needs the return-by-move change as well, without which the recursive copy constructor overflows on the way out; that is the parent commit, and the test for the value path covers the two together. Timing is unchanged: parsing 60,000 small objects and one array of a million integers is within run-to-run noise of develop either way. Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-09-11 08:34:43 +02:00
Niels Lohmann	44f8ec30e9	Bound UBJSON optimized arrays of a valueless type (#5504) ... * Bound UBJSON optimized arrays of a valueless type An element of type 'Z' (null), 'T' (true) or 'F' (false) is encoded by its type marker alone, so an optimized UBJSON array of one of those has no payload: reading an element consumes no input at all. Its declared count is therefore the only thing that decides how much is allocated, and nothing bounded it. "[$Z#l" and a four-byte count is nine bytes of input describing two billion values; #2793 reports 35 GB and 150 seconds from ten bytes, and OSS-Fuzz has an out-of-memory and a timeout report for the same shape. Every other type costs at least one byte per element, so the end of the input bounds it. 'N' (no-op) is already skipped rather than stored. Objects are not affected either: each element is preceded by its key, which costs bytes. And BJData already refuses these markers as an optimized type, so this is a plain UBJSON matter. Reject a count above 1,048,576 elements for those three types with out_of_range.408, the code this reader already uses for a declared size it will not honour. The check runs before the SAX start event, so no container is opened and then abandoned. Rejecting on the read side alone would break the guarantee that anything to_ubjson() writes can be read back, and would trip the round-trip assertion in fuzzer-parse_ubjson.cpp. So the writer falls back to the unoptimized encoding, one byte per element, for arrays of these types above the same limit. Its decision depends only on the array's size, which is identical for a value and for anything parsed back from it, so the round trip is stable. No existing test changes: the largest such count in the test suite is 65,793. The excessive-size test that already used this shape still passes, now rejected a little earlier than by the max_size() check it used to reach. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Note the 1,048,576 valueless-array limit as (1 << 20) in the docs Addresses review feedback from @gregmarr on PR #5504: spell out the binary/hex form next to the decimal count so it reads as the round power-of-two it is, matching how include/nlohmann/detail/input/binary_reader.hpp defines max_valueless_container_size. Applied in both docs/exceptions.md and ubjson.md, as requested. Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-09-11 08:34:42 +02:00
Niels Lohmann	4bb2de8cc5	Reject a nested BJData ndarray dimension vector where it is read (#5503) ... get_ubjson_size_type() takes an inside_ndarray parameter saying whether it is being called for an ndarray's dimension vector, where another ndarray is not allowed. It then seeded the flag it passes down to get_ubjson_size_value() with `false` rather than with that parameter, and only consulted inside_ndarray afterwards, on the '$' branch. So on the '#' branch nothing stopped the descent: every "#[" pair of an input like "[" followed by "#[#[#[..." opened another dimension vector, several native stack frames deeper each time, and the recursion was only reported on the way back out. 100,000 pairs crash the process. This is #5104 again, in a path that has nothing to do with containers. Seed the flag with inside_ndarray, which is what get_ubjson_size_value() documents it wants: "for input, `true` means already inside an ndarray vector or ndarray dimension is not allowed". The nested '[' is then refused where it is read, so the length of the chain no longer matters. Both post-checks gain `&& !inside_ndarray`, because an ndarray was found *here* only if the flag flipped -- get_ubjson_size_value() only ever returns `true` when its initial value was `false`, as its documentation says. With that, the "ndarray can not be recursive" branch is unreachable: a recursive ndarray is now caught one level earlier, and reported as "ndarray dimensional vector is not allowed" like every other nested dimension vector. Three existing expectations move accordingly (vR2, vR4, vR6). All three now fail earlier, and all three now report the same error that vR1, vR5 and vH already reported for the same shape, which is the more consistent outcome. Everything else is unchanged: valid 1D and 2D ndarrays, optimized containers and plain arrays produce identical results, and unit-ubjson is untouched. Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-09-11 08:34:41 +02:00
Niels Lohmann	dd50f0eb16	Stop CBOR indefinite-length strings from recursing per chunk (#5502) ... get_cbor_string() and get_cbor_binary() handled the indefinite-length forms (0x7F and 0x5F) by calling themselves once per chunk. Each chunk therefore cost a native stack frame, and since a chunk may itself be an indefinite- length string, an input of repeated 0x7F bytes reached one frame per input byte: 200,000 of them crash the process with SIGSEGV before a single byte is rejected. This is the same defect as #5104, in a path the container-level work does not touch. Count the open levels instead of recursing through them. That is enough here because every chunk is appended to the same result -- get_bytes() writes at result.size() -- so there is no per-level state to keep. The temporary chunk string and its copy into the result go away with the recursion. The definite-length cases move to get_cbor_string_chunk() and get_cbor_binary_chunk() unchanged, including their error messages, which still name 0x7F and 0x5F because those are handled one level up. Behaviour is unchanged. Comparing against develop over the interesting byte sequences -- empty, single-chunk, nested, over-closed and truncated forms, both strings and byte arrays, and an indefinite-length map key -- produces identical values, error codes, messages and byte offsets. The 200,000-level input now reports parse_error.110 at byte 200001 instead of crashing. Note that nesting these is not valid CBOR: RFC 8949, Section 3.2.3 forbids it. This does not change that either way -- it has always been accepted, and rejecting it is a separate decision (#5317, #5325). Should it be rejected later, that is now one condition on the level counter rather than a change to the control flow. Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-09-11 08:34:41 +02:00
Sahil_Kamate	b5378e8deb	Fix CBOR tag handlers not recognizing tags 0-5 and 21-23 (#5331) ... * Fix CBOR tag handlers not recognizing tags 0-5 and 21-23 The tagged-item switch in binary_reader::parse_cbor_internal() only handled head bytes 0xC6-0xD4 and 0xD8-0xDB. Bytes 0xC0-0xC5 (tags 0-5: date/time, epoch, bignum, decimal, bigfloat) and 0xD5-0xD7 (tags 21-23: base64url, base64, base16 conversion hints) fell through to the default case and were reported as invalid bytes, even under cbor_tag_handler_t::ignore and ::store, despite being valid CBOR major-type-6 tags per RFC 8949. Add the missing case labels so the full 0xC0-0xDB range is handled uniformly. Extend the "Tagged values" test in unit-cbor.cpp to cover 0xC0-0xD7, and update the CBOR docs to state the corrected tag range. Fixes #5315 Signed-off-by: sahilkamate03 <45514385+sahilkamate03@users.noreply.github.com> * Fix stale CBOR tag docs and add store-mode binary-payload test The "Incomplete mapping" warning still listed tags 0-5 (date/time, bignum, decimal fraction, bigfloat) and 21-23 (expected conversions) as unsupported, even though they now parse correctly under cbor_tag_handler_t::ignore/store, same as 0xC6..0xD4/0xD8..0xDB. Remove those five bullets and cross-reference the "Tagged items" warning below, matching the equivalent docs fix landed independently in PR #5367. Also add a cbor_tag_handler_t::store test that wraps a binary payload (not just a string) for every byte in 0xC0..0xD7, confirming these tags are unwrapped the same way as 0xC6..0xD4 rather than mistaken for the 0xD8..0xDB binary-subtype marker syntax, per review feedback on #5331. Signed-off-by: sahilkamate03 <45514385+sahilkamate03@users.noreply.github.com> --------- Signed-off-by: sahilkamate03 <45514385+sahilkamate03@users.noreply.github.com>	2026-08-19 20:19:47 +02:00
Dmitry	1c136a66c4	Move the CBOR doc block to the function it describes (#5363) ... The block documenting get_char and tag_handler sat above get_cbor_negative_integer(), which takes neither, so Doxygen attached it there and parse_cbor_internal() was left undocumented. Comment placement only. Signed-off-by: Dmitry <45711841+darkdi@users.noreply.github.com>	2026-08-06 08:30:15 +02:00
Niels Lohmann	d5647e6a3b	Resolve the TODO(niels) in get_ubjson_string (#5355) ... The comment asked whether the no-op marker 'N' may be ignored when a string is read. It may not: at that point the next byte must be a string length type specification, and 'N' is not one. No-ops at positions where a value may start are already consumed by the callers through get_ignore_noop(), so nothing is lost by not skipping them here. Replace the TODO with a comment stating that, and add regression tests pinning both directions: a no-op is accepted at top level (also repeated), before and after an array element, and before an object key, between key and value, and before the closing brace of an object of unknown size; it is rejected where a length type specification is expected, i.e. after the 'S' marker of a string value and as the key length of an object of known size. Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-08-05 14:47:40 +02:00
tomatotomata	2222d386c9	fix: check CBOR tagged subtype reads (#5339)	2026-07-31 22:06:55 +02:00
Angadi56	d94cbd99dc	reject CBOR array/map length equal to the indefinite-length marker (#5274) ... * reject CBOR array/map length equal to the indefinite-length marker Signed-off-by: Angadi Yashaswini <angadi@digiscrypt.com> * reject CBOR lengths that do not fit in std::size_t via value_in_range_of Signed-off-by: Angadi Yashaswini <angadi@digiscrypt.com> --------- Signed-off-by: Angadi Yashaswini <angadi@digiscrypt.com>	2026-07-31 18:04:30 +02:00
hum4nBeing	bc48951128	Fix UBJSON high-precision floating-point overflow handling (#5323) ... This adds a std::isfinite check to the UBJSON floating-point parsing path, throwing out_of_range.406 on overflow. This makes the UBJSON parser's behavior consistent with the normal JSON parser. Fixes #5322. Signed-off-by: AJ369ninja <abhishek.j@iitg.ac.in> Co-authored-by: AJ369ninja <abhishek.j@iitg.ac.in>	2026-07-31 18:04:13 +02:00
Yash Bavadiya	dd24e2dffd	check all BSON reads and add an EOF check for booleans (#5332) ... Signed-off-by: Yash Bavadiya <krbavadiya11@gmail.com>	2026-07-30 23:44:31 +02:00
Patrick10199	868506dcc0	Fix CBOR half-float assertion bounds (#5335) ... Signed-off-by: Patrick Armstrong <patrick@erpassistant.ai>	2026-07-30 23:38:13 +02:00
Angadi56	9a3ebb9456	validate BSON document size against the bytes read (#5287)	2026-07-23 19:51:40 +00:00
Angadi56	3565f40229	reject negative UBJSON/BJData string length (#5284)	2026-07-20 20:32:38 +00:00
Niels Lohmann	83c87cb9e0	Read binary strings/blobs in bulk chunks with a memcpy fast path (#5233)	2026-07-05 19:26:02 +02:00
Ville Vesilehto	457bc283ff	fix(cbor): reject overflowing negative integers (#5039) ... * fix(cbor): reject negative ints overflowing int64 CBOR encodes negative integers as "-1 - n" where n is uint64_t. When n > INT64_MAX, casting to int64_t caused undefined behavior and silent data corruption. Large negative values were incorrectly parsed as positive integers (e.g., -9223372036854775809 became 9223372036854775807). Add bounds check for to reject values that exceed int64_t representable range, returning parse_error instead of silently corrupting data. Added regression test cases to verify. Signed-off-by: Ville Vesilehto <ville@vesilehto.fi> * chore: clarify tests Add test for "n=0" case (result=-1) to cover the smallest magnitude boundary. Update comments to explain CBOR 0x3B encoding and why "result=0" is not possible. Clarify that n is an unsigned integer in the formula "result = -1 - n" to help understanding the tests. Signed-off-by: Ville Vesilehto <ville@vesilehto.fi> * fix(cbor): extend overflow checks for other types Extend negative integer overflow detection to all CBOR negative integer cases (0x38, 0x39, 0x3A) for consistency with the existing 0x3B check. Signed-off-by: Ville Vesilehto <ville@vesilehto.fi> --------- Signed-off-by: Ville Vesilehto <ville@vesilehto.fi>	2026-01-12 10:17:47 +01:00
Niels Lohmann	515d994acb	📄 adjust year (#5044) ... Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-01-01 20:00:39 +01:00
Niels Lohmann	54be9b04f0	📄 update REUSE (#4960)	2025-10-23 06:56:36 +02:00
Niels Lohmann	cf16c5ab9f	Use binary_t::value_type (#4805)	2025-06-02 06:35:27 +02:00
Niels Lohmann	9110918cf8	Fix typos (#4748) ... * ✏️ fix typos Signed-off-by: Niels Lohmann <mail@nlohmann.me> * ✏️ address review comments Signed-off-by: Niels Lohmann <mail@nlohmann.me> * ✏️ address review comments Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2025-05-04 10:28:24 +02:00
Ville Vesilehto	dff2b4756c	fix: BJData size calculation overflow (#4765) ... Adds pre-multiplication overflow detection to catch cases where dimension products would exceed size_t max. The previous check only detected when overflow resulted in exactly 0 or SIZE_MAX, missing other cases. Retains the original post-multiplication check for backward compatibility. Adds tests verifying overflow detection with dimensions (2^32+1)×(2^32), which previously overflowed silently to 2^32. This prevents custom SAX handlers from receiving incorrect array sizes that could lead to buffer overflows. Signed-off-by: Ville Vesilehto <ville@vesilehto.fi>	2025-04-29 10:17:50 +02:00
Niels Lohmann	eef76c200e	Make library work with C++20 modules (#4764) ... * ✅ add test for C++20 modules Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 🚨 fix warning Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Add missing header (#4763) * 🐛 add missing header Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 🚨 fix warning Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 🚨 fix warning Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2025-04-28 21:52:26 +02:00
Niels Lohmann	c67d538274	Fix C4702 warning and extend MSVC CI job (#4749) ... * ⚗️ try matrix for latest Signed-off-by: Niels Lohmann <mail@nlohmann.me> * ♻️ refactor from https://github.com/nlohmann/json/issues/4745#issuecomment-2810128420 Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 👷 simplify CI Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 👷 simplify CI Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 🚨 fix cpplint warning Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 👷 simplify CI Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2025-04-17 18:04:09 +02:00
Niels Lohmann	1705bfe914	🔖 set version to 3.12.0 (#4727) ... Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2025-04-11 10:41:14 +02:00
Niels Lohmann	f06604fce0	Bump the copyright years (#4606) ... * 📄 bump the copyright years Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 📄 bump the copyright years Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 📄 bump the copyright years Signed-off-by: Niels Lohmann <niels.lohmann@gmail.com> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me> Signed-off-by: Niels Lohmann <niels.lohmann@gmail.com>	2025-01-19 17:04:17 +01:00
Michael Valladolid	2d42229f4d	Support BSON uint64 de/serialization (#4590) ... * Support BSON uint64 de/serialization Signed-off-by: Michael Valladolid <mikevalladolid@gmail.com> * Treat 0x11 as uint64 and not timestamp specific Signed-off-by: Michael Valladolid <mikevalladolid@gmail.com> --------- Signed-off-by: Michael Valladolid <mikevalladolid@gmail.com>	2025-01-10 14:59:55 +01:00
Nebojša Cvetković	2e50d5b2f3	BJData optimized binary array type (#4513)	2025-01-07 18:09:19 +01:00
Michael Valladolid	4f64d8d0b4	Modernize integer comparison (#4577) ... Replace static_cast<size_t>(-1) with std::numeric_limits<std::size_t>::max() via the detail::unknown_size() function	2025-01-01 17:01:38 +01:00
Sushrut Shringarputale	58f5f25968	json start/end position implementation (#4517) ... * Add implementation to retrieve start and end positions of json during parse * Add more unit tests and add start/stop parsing for arrays * Add raw value for all types * Add more tests and fix compiler warning * Amalgamate * Fix CLang GCC warnings * Fix error in build * Style using astyle 3.1 * Fix whitespace changes * revert * more whitespace reverts * Address PR comments * Fix failing issues * More whitespace reverts * Address remaining PR comments * Address comments * Switch to using custom base class instead of default basic_json * Adding a basic using for a json using the new base class. Also address PR comments and fix CI failures * Address decltype comments * Diagnostic positions macro (#4) Co-authored-by: Sush Shringarputale <sushring@linux.microsoft.com> * Fix missed include deletion * Add docs and address other PR comments (#5) * Add docs and address other PR comments --------- Co-authored-by: Sush Shringarputale <sushring@linux.microsoft.com> * Address new PR comments and fix CI tests for documentation * Update documentation based on feedback (#6) --------- Co-authored-by: Sush Shringarputale <sushring@linux.microsoft.com> * Address std::size_t and other comments * Fix new CI issues * Fix lcov * Improve lcov case with update to handle_diagnostic_positions call for discarded values * Fix indentation of LCOV_EXCL_STOP comments * fix amalgamation astyle issue --------- Co-authored-by: Sush Shringarputale <sushring@linux.microsoft.com>	2024-12-18 22:46:14 +01:00
Niels Lohmann	1b9a9d1f21	Update licenses (#4521) ... * 📄 update licenses * 📄 update licenses	2024-11-29 17:38:42 +01:00
Tianyi Chen	935c6eeb5a	Optimize binary get_number implementation by reading multiple bytes at once (#4391) ... * multibyte binary reader * wide_string_input_adapter fallback to get_character Update input_adapters.hpp * Update json.hpp * Add from msgpack test * Test for broken msgpack with stream, address some warnings * Reading binary number from wchar as an error, address warnings * Not casting float to int, it violates strict aliasing rule	2024-11-29 09:19:58 +01:00
Niels Lohmann	9cca280a4d	JSON for Modern C++ 3.11.3 (#4222)	2023-11-28 22:36:31 +01:00
Colby Haskell	1d597743d8	Fix char_traits deprecation warning (#4179)	2023-11-27 06:51:25 +01:00
Niels Lohmann	f56c6e2e30	Update documentation for the next release (#4216)	2023-11-26 15:51:19 +01:00
Niels Lohmann	836b7beca4	Fix CI, again (#4083)	2023-09-07 20:41:12 +02:00
Dirk Stolle	4b2c8ce6bc	Fix some typos for n-dimensional arrays (#3767)	2022-09-26 06:23:18 +02:00
Niels Lohmann	58bd97e2b1	Add clang-tools to required tools for ci_static_analysis_clang (#3724) ... * 💚 add clang-tools to required tools for ci_static_analysis_clang * 🚨 update Clang-Tidy warning selection * 🚨 fix Clang-Tidy warnings * 🚨 fix Clang-Tidy warnings * 🚨 fix Clang-Tidy warnings * 🚨 fix Clang-Tidy warnings * 🚨 fix Clang-Tidy warnings * 🚨 fix Clang-Tidy warnings * 🚨 fix Clang-Tidy warnings * 🚨 fix Clang-Tidy warnings * 🚨 fix Clang-Tidy warnings * 🚨 fix Clang-Tidy warnings * 🚨 fix Clang-Tidy warnings (#3738) * ⏪ revert fix * ⏪ revert fix * 🚨 fix Clang-Tidy warnings (#3739) Co-authored-by: Florian Albrechtskirchinger <falbrechtskirchinger@gmail.com>	2022-09-13 12:58:26 +02:00
Niels Lohmann	9d69186291	🔖 set version to 3.11.2	2022-08-12 15:04:06 +02:00