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| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
  Niels LohmannandClaude Opus 4.8
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4a93aa4e2f |
Speed up parsing of contiguous input (numbers, strings, UTF-8) (#5283)
* Speed up number parsing in the lexer (fast paths from the fast_float/simdjson world) The number scanner converted its already-validated digit buffer with std::strtoull/std::strtoll/std::strtod. Those pull in locale and errno machinery and dominate number-heavy parsing (strtod runs at ~6 M/s). Replace them with dedicated parsers over the validated buffer: - parse_integer_unsigned / parse_integer_signed: accumulate digits with overflow detection, falling back to the float path on overflow exactly as the strtoull/strtoll round-trip check did. Overflow behavior is unchanged for narrower or wider custom number types. - parse_float_fast: Clinger's exact fast path for `double` (<=19 significant digits, |exp10| <= 22, significand < 2^53), where significand * 10^exp is exact under IEEE round-to-nearest. This is the same fast path used by fast_float/simdjson. It is bit-identical to strtod on this subset and declines (falling back to strtod) otherwise. Only `double` uses it; float and long double keep std::strtof/std::strtold via a templated overload. Measured on representative data (g++ 13, -O3): - integers: DOM parse +11%, SAX +25-34% - floats: DOM parse +37%, SAX +70% (clang: float DOM ~1.9x) No dependencies added; header-only and C++11-clean. Existing parser, lexer, conversion and deserialization unit tests pass unchanged; a 3M-value random-double fuzz matches strtod bit-for-bit. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AXcDtEma2PjxgmPS9cQGzA Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Add SWAR bulk string scanning for contiguous input (simdjson-style) scan_string() read the input one character at a time through the input adapter and classified every byte with a large switch. For contiguous byte buffers we can instead scan 8 bytes at a time with a SWAR word test that finds the first byte needing individual handling (the closing quote, an escape, a control character, or a non-ASCII UTF-8 byte) and bulk-append the ordinary run in one go. - input adapters expose supports_bulk_scan / bulk_data / bulk_remaining / bulk_skip for provably-contiguous, same-type, 1-byte iterator ranges (raw pointers in every standard; std::string/std::vector/std::array and friends additionally in C++20 via std::contiguous_iterator). - the lexer gains a bulk_scan capability (gated on lazy_token_string so bypassing the per-character capture cannot lose error diagnostics) and a scan_string_bulk() fast path; streaming/wide/user adapters are unchanged and keep the byte-at-a-time scanner. The run contains no newline (all bytes < 0x20 are treated as special), so position bookkeeping stays exact, and error tokens are still reconstructed lazily from the consumed byte range. The SWAR special-byte test is pure uint64_t arithmetic - no intrinsics, no runtime dispatch, C++11-clean. Measured on representative data, pointer input, g++ 13 -O3 (string values discarded by accept() see the largest gains): long ASCII strings: DOM +4.5x, SAX +14x, accept +17x (to ~2 GB/s) short strings: DOM +15%, SAX +62%, accept +85% escape-heavy: DOM +31%, SAX +26%, accept +28% Same-input parity verified: 200k randomized documents (escapes, multibyte UTF-8, surrogate pairs) accept/parse identically via the contiguous SWAR path and the streaming byte path; unit lexer/parser/diagnostic-position/ deserialization/conversions suites pass unchanged. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AXcDtEma2PjxgmPS9cQGzA Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Validate UTF-8 in the bulk string scanner (portable ~2-3x on non-ASCII text) The SWAR bulk string path stopped at the first non-ASCII byte and handed every multibyte character to the byte-at-a-time scanner, whose per-byte get()/next_byte_in_range()/add() machinery runs at roughly half the speed of validating straight from the buffer. As a result, dense non-ASCII text (CJK, emoji, accented Latin) parsed ~10-15x slower than ASCII. Fold well-formed UTF-8 into the bulk run: scan_string_bulk() now, on a non-ASCII lead byte, validates one sequence with validate_one_utf8() - which mirrors scan_string()'s per-byte switch ranges exactly (rejecting overlong forms, surrogates, and out-of-range code points) - and appends it in place, continuing until the closing quote, an escape, a control byte, or an ill-formed sequence. All error handling still defers to the byte path, so error messages and positions are byte-for-byte unchanged. Because only well-formed content is fast-pathed and every rejection falls through to the existing scanner, behavior is identical; the win is purely throughput. Measured on pointer input (accept, string values discarded): content g++ 13 clang 18 dense CJK 277 -> 648 ~605 MB/s (~2.3x) dense emoji 299 -> 857 ~702 MB/s (~2.6-2.9x) mixed 90% ASCII 246 -> 331 ~334 MB/s (~1.35x) pure ASCII unchanged (~3.2 / 4.1 GB/s) Verified: 2,000,000 randomized documents built from arbitrary bytes (overlong, surrogate, truncated, out-of-range sequences) accept/reject and parse identically via the contiguous path and the streaming byte path; lexer/parser/diagnostic-position/deserialization/conversions suites pass unchanged. Pure C++11, no intrinsics. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AXcDtEma2PjxgmPS9cQGzA Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Route contiguous byte containers through the pointer adapter (fast paths in C++11) json::parse(std::string) - the most common entry point - did not benefit from the contiguous fast paths (bulk string scanning, UTF-8 bulk validation, memcpy for binary formats) in C++11..17: std::string::iterator is a library wrapper, not a raw pointer, and pre-C++20 there is no portable way to prove it contiguous, so supports_bulk_scan was false. Only raw pointers, string literals, and C-arrays (and, in C++20, anything modelling std::contiguous_iterator) took the fast path. Detect contiguous single-byte containers (std::string, std::vector<char>, std::vector<std::uint8_t>, std::string_view, ...) via is_contiguous_byte_ container and route them through an iterator_input_adapter built from data()/data()+size(). The generic iterator-based container overload is constrained to exclude these, so the two overloads are disjoint and there is no ambiguity (a plain competing overload loses to the greedy forwarding-reference container overload on reference binding, and a factory partial-specialization is ambiguous - both were tried and rejected). The pointer keeps the container's own element type, so char_type - and therefore all parsing behavior - is byte-for-byte identical to the iterator path (const char* for std::string, const std::uint8_t* for std::vector<std::uint8_t>); only the raw pointer additionally turns on the fast paths. Lifetimes are unchanged: the container outlives the adapter for the full parse expression, exactly as the iterators it replaces did. Measured, C++11, json::parse/accept(std::string), g++ 13: long ASCII strings: accept 201 -> 3200 MB/s (~16x), parse 174 -> 1444 dense CJK: accept 263 -> 697 MB/s (~2.6x) short strings: accept 163 -> 243 MB/s (~1.5x) Verified: char_type preserved for std::string (char) and std::vector<std::uint8_t> (uint8_t); CBOR/MsgPack round-trips from std::vector<std::uint8_t> unchanged; 1,000,000 randomized documents accept and parse identically via std::string and via std::istream; deserialization/user-defined-input/parser/lexer/conversions/diagnostic- position suites pass (20,480 assertions); warning-clean on g++ and clang in C++11/17/20. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AXcDtEma2PjxgmPS9cQGzA Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Add optional simdutf backend for bulk UTF-8 validation (JSON_USE_SIMDUTF) The bulk string scanner validates UTF-8 straight from a contiguous buffer. The scalar validator caps at ~0.3-0.7 GB/s on non-ASCII text; a SIMD validator reaches several GB/s. Rather than hand-rolling SIMD UTF-8 validation (easy to get subtly wrong - a from-scratch SSE attempt rejected valid CJK), wire in the vetted simdutf library behind an opt-in switch. simdutf is not header-only (it ships simdutf.cpp and uses runtime CPU dispatch), so it is not vendored: defining JSON_USE_SIMDUTF includes <simdutf.h> and routes the bulk validator through simdutf::validate_utf8; the project supplies and links simdutf. Undefined (the default), nothing external is included and the portable C++11 scalar path is used, so the library stays header-only and its baseline behavior is unchanged. Design keeps behavior identical either way: - scan_string_bulk() now finds the run up to the next quote/escape/control byte (non-ASCII allowed) and validates it in one shot; on the rare validation failure it recomputes the exact valid prefix with the scalar helper, so ill-formed input still falls through to the byte path and is reported at the same position with the same message. - the per-sequence scalar path is factored into scalar_string_bulk_run() and is the default backend; the refactor is behavior-preserving and does not change scalar throughput. Verified: default and JSON_USE_SIMDUTF builds accept/reject/parse identically across 2,000,000 arbitrary-byte documents and 1,000,000 mixed-escape/UTF-8 documents (differential fuzz vs the streaming byte path); lexer/parser/diagnostic-position/deserialization suites pass under both configurations (20,188 assertions with the backend enabled); warning-clean on g++ and clang, C++11 and C++20, both configurations. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AXcDtEma2PjxgmPS9cQGzA Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Add a contiguous fast path for scanning numbers scan_number() reads a number one character at a time through the input adapter (get()) and appends each byte to token_buffer (add()) before converting. For contiguous input, the per-character get()/add() overhead dominates: it is roughly two thirds of the time spent on number-heavy parsing, far more than the value conversion itself. Add scan_number_bulk_contiguous(), which parses the whole number token straight from the input buffer: it validates and classifies the extent with the same grammar as scan_number()'s state machine, materializes token_buffer in one copy (substituting the locale decimal point exactly as scan_number() does), advances the adapter, and reuses the shared convert_number() tail. On anything it does not recognize as a well-formed number it makes no state change and returns token_type::uninitialized, so the caller falls back to scan_number(), which then produces the exact diagnostic. Errors and their positions are therefore unchanged. The conversion tail is factored out of scan_number() into convert_number() so both scanners share it; the fast path is selected by tag dispatch on the existing bulk_scan capability, so streaming/wide/user adapters are unaffected. Measured on pointer input, g++ 13 -O3: - integers: parse +65%, accept +98% - floats: parse +39%, accept +70% Verified: 2,000,000 randomized number documents (including overflow-range integers, long digit strings and %.17g doubles) parse identically via the contiguous path and the streaming byte path, matching value, type and round-trip text; the locale suite and existing parser/lexer/conversions/ deserialization tests pass; a new "lexer number fast path" test checks contiguous-vs-streaming parity, token classification, and that malformed numbers are rejected identically. Pure C++11, no intrinsics. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AXcDtEma2PjxgmPS9cQGzA Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Move byte-level scan/parse helpers out of lexer.hpp lexer.hpp had grown by ~600 lines of byte-level helpers that have no dependency on the lexer's template parameters and clutter the state machine. Move them, unchanged, into two focused headers as free functions in namespace detail: - number_parse.hpp: parse_integer_unsigned/parse_integer_signed (now templated on the number type) and parse_float_fast (Clinger's exact double fast path, with the decimal point passed as an argument instead of read from a lexer member). - string_scan.hpp: the SWAR string helpers (is_string_special, swar_string_special, find_string_special, validate_one_utf8, scalar_string_bulk_run) and the backend-dispatched string_bulk_run, including the optional simdutf include and find_string_delimiter. lexer.hpp now includes these and calls the free functions; the methods that touch lexer state (scan_string, scan_number, scan_string_bulk, scan_number_bulk_contiguous, convert_number) stay put. This is a pure code move with no behavior change: lexer.hpp drops from 2357 to 1934 lines, the now-unused <cstdint>/<cstring>/<limits> includes are removed, and the free-function form makes the SWAR helpers reusable elsewhere (e.g. the serializer's string escaping). Verified: default and JSON_USE_SIMDUTF builds compile; 2,000,000 number and 2,000,000 arbitrary-byte-string differential-fuzz documents parse identically to before; lexer/parser/conversions/deserialization/locale/ diagnostic-position suites pass (20,576 assertions); warning-clean on g++ and clang in C++11/17/20; the amalgamation regenerates and passes check-amalgamation. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AXcDtEma2PjxgmPS9cQGzA Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Fix clang-tidy findings and document JSON_USE_SIMDUTF in the nav - number_parse.hpp: use std::array for the powers-of-ten table (avoid-c-arrays) and `auto` for the cast-initialized result (modernize-use-auto), matching the codebase style (cf. the serializer's utf8d table). Indexing casts keep the -Wsign-conversion build clean. - add JSON_USE_SIMDUTF to the mkdocs navigation so the macro page is reachable. No behavior change; clang-tidy is clean on the new headers and the amalgamation is regenerated. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AXcDtEma2PjxgmPS9cQGzA Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Fix number fast path for custom string types without assign() The contiguous number fast path materialized token_buffer with token_buffer.assign(data, len), but string_t is only required to provide the minimal interface the rest of the lexer uses (push_back, append, clear, operator[], ...). Custom string types such as the test's alt_string do not implement assign(), so scan_number_bulk_contiguous() failed to compile for them (unit-alt-string), breaking the gcc/clang standards and old-compiler CI jobs. reset() already clears token_buffer, so fill it with append() - which alt_string and std::string both provide and which the string fast path already relies on - instead of assign(). Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AXcDtEma2PjxgmPS9cQGzA Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Satisfy clang-tidy: parenthesize math and drop unused forwarding reference The CI clang-tidy (newer than the locally available version) reported two additional checks on the new code: - readability-math-missing-parentheses: parenthesize the (a * b) + c digit accumulations in number_parse.hpp. - cppcoreguidelines-missing-std-forward: the contiguous-byte-container input_adapter overload took a forwarding reference but only reads data()/size() and never forwards it. It is already disjoint from the generic container overload via SFINAE, so a plain const& is correct and clearer (and keeps the container alive for the whole parse just as before). No behavior change; char_type and routing are unchanged (std::string and std::vector<std::uint8_t> still take the pointer adapter with char/uint8_t char_type), CBOR/MsgPack round-trips and the 2M number fuzz still pass. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AXcDtEma2PjxgmPS9cQGzA Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Use std::from_chars (Eisel-Lemire) for float conversion when available The Clinger fast path is exact only for the "easy" subset (<=19 significant digits, |exp10| <= 22); high-precision and scientific floats fall through to strtod, where the failed Clinger attempt actually makes parsing a net loss. std::from_chars implements the Eisel-Lemire algorithm in modern standard libraries: locale-independent, correctly rounded, and fast over the whole value range. convert_number() now tries parse_float_from_chars() first (guarded by __cpp_lib_to_chars, so C++11 and libc++-without-float-support keep the Clinger + strtod path unchanged), then Clinger, then strtof. from_chars is used only when it consumes the entire token; a partial parse means a non-'.' locale decimal point, and an under-/overflow (result_out_of_range) also declines - in both cases the existing strtod fallback supplies the exact value and the well-defined +/-inf/0 the parser expects, side-stepping the P4168 divergence between implementations. float and long double now get the fast path too (Clinger was double-only). Measured, C++17, g++ 13 -O3, json::parse/accept: - canada-style floats: ~unchanged (Clinger already covered them) - high-precision (17 digits): parse 2.1x, accept 2.5x - scientific (17 digits + exp): parse 3.6x, accept 4.1x Verified: C++11 (Clinger/strtod) and C++17 (from_chars) parse every value - including subnormals, boundary values, and 1e9999/1e-9999 over-/underflow - to bit-identical results; 2M number-fuzz clean; conversions/deserialization/ locale/number-fast-path suites pass in both C++11 and C++17; clang-tidy clean; warning-clean on g++ and clang in C++11/17/20. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AXcDtEma2PjxgmPS9cQGzA Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Guard from_chars use on JSON_HAS_CPP_17, not just __cpp_lib_to_chars libstdc++ 15 defines __cpp_lib_to_chars even in C++14 mode (via bits/version.h pulled in by other headers), but <charconv> is only included under JSON_HAS_CPP_17. That made parse_float_from_chars() reference std::from_chars without the header in C++14 builds, breaking gcc-latest, icpx, and the offline-testdata jobs. Gate the use on JSON_HAS_CPP_17 && __cpp_lib_to_chars so it matches the include condition exactly; C++11/14 always take the scalar fallback. Verified by forcing __cpp_lib_to_chars in a C++14 build: the guard suppresses std::from_chars and it compiles. C++17 behavior is unchanged. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AXcDtEma2PjxgmPS9cQGzA Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Disable Clinger float fast path under extended FP precision (x87) The contiguous number fast path uses a Clinger-style exact algorithm (significand * 10^scale in double arithmetic), which is only correctly rounded when double operations are evaluated in true 53-bit precision. On the x87 FPU used by 32-bit x86 (FLT_EVAL_METHOD == 2) the single multiply/divide is computed in 80-bit and then double-rounded to double, so a small fraction of values land 1 ULP off. This surfaced as test-cbor_cpp11 and test-msgpack_cpp11 failing on the mingw (x86) job for regression/floats.json: the C++17 builds pass because they take the correctly-rounded std::from_chars path, while C++11 falls back to parse_float_fast(). A 5M-sample check over shortest round-trip decimals reproduces it: 0 divergences with 53-bit doubles, ~1 in 25 000 with 80-bit intermediates; declining to std::strtod fixes all of them. Guard parse_float_fast() on FLT_EVAL_METHOD so it declines whenever the platform evaluates doubles in extended precision, letting the caller use the correctly-rounded std::from_chars / std::strtod path instead. On mainstream x86-64/ARM64 (FLT_EVAL_METHOD == 0) the fast path is unchanged. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AXcDtEma2PjxgmPS9cQGzA Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Guard <charconv> include with __has_include for GCC 7 GCC 7 sets __cplusplus to the C++17 value under -std=gnu++1z, so JSON_HAS_CPP_17 is defined, but its libstdc++ ships no <charconv> header (added in GCC 8; floating-point from_chars in GCC 11). The unconditional "#if defined(JSON_HAS_CPP_17) #include <charconv>" therefore failed to compile there: "fatal error: charconv: No such file or directory" in the ci_test_compilers_gcc (7) job. Wrap the include in __has_include(<charconv>), mirroring the library's existing handling of <version> and <filesystem> in macro_scope.hpp. When the header is absent, __cpp_lib_to_chars stays undefined and parse_float_from_chars() takes its scalar fallback, so the from_chars use site (already gated on __cpp_lib_to_chars) is never reached. GCC 8-10, which have <charconv> but no floating-point from_chars, are unaffected: they include the header but still take the fallback. GCC 11+ is unchanged. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AXcDtEma2PjxgmPS9cQGzA Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Restore the column when ungetting a newline The contiguous number fast path never reads the character that terminates a number token, while scan_number() reads it and then ungets it. When that character is a newline, get() has already cleared chars_read_current_line, and unget() could only restore lines_read - leaving the column at 0. The two paths therefore reported different columns for the same document: json::parse("[01\n]") -> line 1, column 3 json::parse(stringstream) -> line 1, column 0 Remember the column the newline was read at so unget() can restore it. Both paths now report the position the offending token actually starts at, which also fixes the pre-existing column-0 artifact for streaming input. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Extend the bulk scan fast paths to sized sentinels supports_bulk_scan required IteratorType and SentinelType to be the same type, which excluded std::counted_iterator paired with std::default_sentinel_t - the combination #5268 had already enabled for the memcpy fast path. Such input fell back to the byte-at-a-time scanner even though it is contiguous and its remaining length is computable in O(1). Factor the "distance is computable in O(1)" test into sentinel_is_sized and use it for iterator_is_contiguous, supports_seek, and supports_bulk_scan alike, and share the std::ranges::distance/std::distance dispatch through a remaining_count() helper. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Document JSON_USE_SIMDUTF on the macro overview page The macro was only listed in the API macro index; add it to the supported macros overview alongside the other JSON_USE_* macros, and note that it selects between two definitions of the same inline function and so must be defined identically in every translation unit. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Amalgamate source code Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Cover the counted-iterator bulk scan paths Sized sentinels newly reach the bulk string/number scanners and the seek-based token reconstruction, so exercise both: - diagnostics that quote the offending token, which are rebuilt from the consumed input via copy_consumed_range() - inputs whose count ends before the underlying buffer does, including a closing quote that exists only behind the count, a cut inside an 8-byte SWAR stride, and a cut inside a UTF-8 sequence Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Fix the SentinelType example on iterator_input_adapter The comment offered "a C++20 sentinel or counted_iterator" as examples of a SentinelType, but std::counted_iterator is the IteratorType - the sentinel it pairs with is std::default_sentinel_t. #5268 corrected the same wording in the API documentation and left the code comment behind. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Do not discard the parse result in the error position check json::parse is declared warn_unused_result, and CHECK_THROWS_WITH_AS evaluates its expression as a discarded statement, so the assertion broke the -Werror builds (GCC -Werror=unused-result, MSVC C4834 under /WX). Compare against the helper that already captures the message instead. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Lock the two number grammars together with a parity test The JSON number grammar is encoded twice: as the scan_number() state machine and as the contiguous fast path. The fast path declining on anything it does not recognize keeps most divergence harmless, but if it ever accepted something the state machine rejects the result would be a silent correctness bug, and the existing test only pinned a hand-written list of numbers. Enumerate every string of length 1..4 over "01.eE+-" (2800 tokens) and require both paths to agree on the parsed value and on the exact error message. Verified to fail if the fast path's grammar is perturbed. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Skip token_buffer for integers on the contiguous path An integer token does not need token_buffer: the number_integer and number_unsigned SAX callbacks take only the value, and the overflow diagnostic rebuilds the text from the input via get_token_string(). Convert straight from the input buffer and materialize the token only for the floating-point tail, which still needs a NUL-terminated buffer for strtod. JSON_DIAGNOSTIC_POSITIONS derives a number's start position from get_string().size(), so the copy is kept when that is enabled. The integer dispatch is factored into convert_integer() and shared with convert_number(), so both scanners keep using one implementation. Integer-heavy input, 400k values, -O3: parse accept gcc 16 +14% +23% clang +15% +22% Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Amalgamate source code Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Cover the bulk string and UTF-8 scanners These paths had no dedicated tests and rested on differential fuzzing only. Add three sections, all comparing the contiguous scanner against the byte-at-a-time one on the parsed value and on the exact error message: - every string of length 1..3 over an alphabet of ordinary ASCII, both specials, a control byte, escape characters, UTF-8 lead and continuation bytes, and a byte that is never valid - each at offset 0 and offset 9, so the bulk scanner sees them with and without a run behind them - every kind of run-ending byte at each offset across two 8-byte SWAR words, so multibyte sequences also straddle the word boundary - the boundaries of every range validate_one_utf8() recognizes: shortest and longest encodings, overlongs, both ends of the surrogate block, U+10FFFF and just past it, and truncated sequences Verified to fail if the bulk validator accepts surrogates, and if the SWAR word test stops detecting control characters. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Format the new string fast path test with astyle The pinned astyle expands a braced-init-list used as a range-for range onto several lines; hoist the two offsets into a named vector instead, which reads better and leaves nothing for astyle to reformat. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Fix shadowed locals and guard the exception-dependent tests Two problems in the tests added for the bulk scanners, both found by CI: - the inner `const json j` in the counted-iterator diagnostics shadowed the one declared at test-case scope, which -Wshadow rejects on GCC and clang and C4456 rejects on MSVC under /WX; rename them - the new parity checks parse deliberately invalid input, which calls std::abort() rather than throwing when JSON_NOEXCEPTION is defined, so they would have crashed the no-exception build; guard them the way the other tests do json::accept() does not abort, so the UTF-8 range assertions stay compiled without exceptions and keep covering validate_one_utf8() there. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Gate the C++20 iterator classification on JSON_HAS_RANGES Making supports_bulk_scan depend on iterator_is_contiguous meant the trait is now instantiated for every adapter, not only when get_elements() is called. On standard libraries with an incomplete <ranges> that is fatal: libstdc++ 10 evaluates std::contiguous_iterator<std::counted_iterator<T*>> by calling std::to_address, which needs an operator-> its counted_iterator does not have, so satisfaction checking is a hard error rather than false. Reported by clang 14 + libstdc++ 10. JSON_HAS_RANGES already encodes exactly this ("libstdc++ < 11 has incomplete C++20 ranges", #4440), so require it for the C++20 branch. Affected toolchains fall back to the pointer-only test and the byte-at-a-time scanner, which parses identically, just without the bulk fast paths. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Amalgamate source code Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Satisfy clang-tidy in the new bulk scanner tests - give the helper lambdas an explicit std::string return type and return braced initializer lists (modernize-return-braced-init-list) - replace the C-style array of test cases with a std::vector (modernize-avoid-c-arrays) - silence pro-type-member-init on the two brace-initialized aggregates; default member initializers would stop them being aggregates in C++11 Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Avoid escaped literals in the counted-iterator diagnostics list clang-tidy reads "[\"\\ud834\"]" as a literal better written raw, and the two literals written next to each other in "[\"a\x01""b\"]" as a missing comma. The concatenation was there to stop the hex escape swallowing the following character; build those documents from explicit bytes instead and use raw strings elsewhere. The byte sequences are unchanged. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Reattach convert_number's documentation @gregmarr spotted that convert_integer() was inserted between convert_number() and its doc block, leaving convert_integer() with two stacked blocks and convert_number() with none. Comment only; no code change. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Address review comments on the simdutf backend string_bulk_run() had the same `return scalar_string_bulk_run(...)` in both arms of the `#if`. The simdutf arm already falls through when validation fails, so a single return after the `#endif` says the same thing. The JSON_USE_SIMDUTF example showed `#include <simdutf.h>`, which string_scan.hpp already does under the same guard; users only have to put the header on the include path and link the library, not include it themselves. Set the version history entry to 3.13.0, matching the other macro pages documenting unreleased features. Co-Authored-By: Claude <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01MXDi7NTMKAmoArUZSKMc4T Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Pin the number error position against a non-newline terminator The comment claimed the reported column is the one the offending token starts at. It is the column reached after the token's last character - which is the actual point of the unget() change: a number terminated by a newline now reports what the same number terminated by a space always did. Assert that equality directly, and add a multi-character token where the start and end columns differ, so the invariant cannot be read off a single-character example. Co-Authored-By: Claude <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01MXDi7NTMKAmoArUZSKMc4T Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Do not repeat the integer conversion that just failed scan_number_bulk_contiguous() converts an integer token straight from the input buffer. When the value does not fit, it materializes token_buffer and calls convert_number(), which tried the very same integer conversion again before falling back to floating point. Recording the outcome in number_type skips the second attempt. The resulting token type and value are unchanged: convert_number() reached the float tail either way. Co-Authored-By: Claude <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01MXDi7NTMKAmoArUZSKMc4T Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Require a container's value_type to match what data() points at is_contiguous_byte_container accepted any type with a data() returning a pointer to a single-byte integral plus a size(). That is duck typing: the two members say nothing about size() counting the units data() points at. A type where it does not - fixed-size records, say - was routed to the pointer-based adapter and parsed as [data(), data() + size()) bytes, silently truncating input the iterator-based adapter had read in full: struct record_buffer { using value_type = std::array<char, 4>; std::string bytes; const char* data() const; // raw bytes std::size_t size() const; // in records const char* begin() const; const char* end() const; }; json::parse(record_buffer{"[1,2,3,4,5]"}); // parse error at column 3 Requiring the container's own value_type to be that same element type ties the two together. Every contiguous standard container satisfies it, so std::string, std::vector<char>, std::array<char, N> and std::string_view keep the fast path; anything else falls back to the iterator-based adapter, which is always correct. Co-Authored-By: Claude <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01MXDi7NTMKAmoArUZSKMc4T Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Only compile the simdutf backend from C++17 on simdutf.h rejects anything below C++17 with an #error, so defining JSON_USE_SIMDUTF in a C++11 or C++14 translation unit did not fail with a message about simdutf being unavailable - it failed to compile at all, taking the library's C++11 support with it. Nothing caught this because no build ever compiled that path. Gate the include and both uses on JSON_HAS_CPP_17, the same way number_parse.hpp gates std::from_chars. Below C++17 the macro now has no effect and the scalar validator runs; it accepts and rejects exactly the same input, so the macro is safe to set project-wide even when some translation units use an older standard. Co-Authored-By: Claude <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01MXDi7NTMKAmoArUZSKMc4T Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Test the simdutf backend in CI JSON_USE_SIMDUTF was documented and shipped but never compiled by anything in the repository, so nothing held the backend to the behavior the docs promise. Add JSON_TestSimdutf (OFF by default), which fetches simdutf and defines JSON_USE_SIMDUTF for every test target, and a ci_test_simdutf target that runs the whole suite in that configuration. Because simdutf needs C++17, the suite is built at C++11 as well, so one job covers both the scalar fallback with the macro defined and simdutf itself. The dependency hangs off test_main, whose usage requirements every test target inherits. The library target and the installed CMake package are deliberately untouched: making nlohmann_json link simdutf would put a find_dependency() in the exported package, which is a separate decision. Co-Authored-By: Claude <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01MXDi7NTMKAmoArUZSKMc4T Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Warn when JSON_TestSimdutf cannot reach the simdutf backend simdutf needs C++17: without it the dependency does not even compile, and with a C++17 compiler but no C++17-or-later standard under test it builds and then goes unused. Either way the option silently did nothing useful, or broke the configure step outright. Resolve the tested standards first, then check them: when none of them can reach simdutf, skip the dependency and say so, naming which of the two reasons applies and how to fix it. The tests then run against the scalar validator, which is what would have happened anyway. Co-Authored-By: Claude <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01MXDi7NTMKAmoArUZSKMc4T Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Use record_buffer::data() so clang does not flag it unneeded The record_buffer test type declares data() and size() so the is_contiguous_byte_container trait can see both and still reject the type on its value_type. data() was never called, so clang's -Wunneeded-member-function (under -Weverything -Werror) failed the C++20 build. Assert that data() points at the underlying bytes: it ODR-uses the member and documents the property the type is meant to demonstrate. Co-Authored-By: Claude <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01XAYM1qhSA2FDaDcGfPW3fG Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Skip the float fast path when it cannot succeed parse_float_fast() (Clinger) needs a significand below 2^53, so it always declines once the mantissa has 17 or more significant digits. convert_number() called it unconditionally, so those numbers were walked an extra time before strtod had to run anyway. On streaming input, where scanning is byte-at-a-time and there is no compensating win, that made canada.json about 6% slower than develop. Derive the significant-digit count from token_buffer indices - the digits are not scanned again - and skip the call when it is guaranteed to decline. Both scanners pass the offset where the mantissa ends; the count only has to be corrected for a leading "0", which the JSON grammar admits nowhere else. The integer path returns before the check, so integer-heavy input is unaffected. Values are unchanged: this only avoids an attempt that would have failed. Verified bit-exact against develop over every number in canada.json, floats.json, signed_ints.json, unsigned_ints.json, small_signed_ints.json, citm_catalog.json and twitter.json, for both the contiguous and the streaming scanner. parse, streaming develop before after canada.json 19.4ms 20.5ms 19.3ms floats.json 135.9ms 131.8ms 128.0ms parse, contiguous develop before after canada.json 15.5ms 12.9ms 11.7ms floats.json 98.6ms 69.8ms 66.7ms Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me> Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com> |
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Niels Lohmann
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6d86cc0f6b |
Speed up whitespace skipping in the lexer (#5490)
* Speed up whitespace skipping in the lexer lexer::skip_whitespace() called get() for every whitespace byte, and get() checks the (almost always false, once past the first character) next_unget flag on every call. skip_whitespace() now reads its first character with get() (needed to honor a pending unget() left over from finishing the previous token, e.g. scan_number() always ungets the character that terminated the number) and every further whitespace character with a new get_ignoring_pending_unget() variant that skips that branch, since nothing in the loop calls unget(). This is a narrower fix than the full contiguous-buffer bulk-skip suggested in the issue (scan a run of whitespace directly in the adapter's buffer and update position counters once per run). That approach depends on bulk-scan adapter infrastructure (supports_bulk_scan/bulk_data()/bulk_skip()) introduced by the open, unmerged parser-performance PR #5283, which this change intentionally does not depend on or replicate. Building new bulk-scan adapter infrastructure from scratch was judged out of scope/riskier than warranted here, so this change is limited to the safe, always-correct improvement of removing redundant per-character bookkeeping from the existing byte-at-a-time loop; full bulk-skipping is left as future work once #5283 (or equivalent adapter support) lands. Line/column/byte-offset bookkeeping is untouched and verified bit-for-bit identical before and after this change, including for pretty-printed (dump(4)) input with embedded newlines. Fixes #5412 Stacked on top of the PR for #5411 (branch issue-5411-lexer-skip-conversion). Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Fix codegen regression in skip_whitespace() from #5490 Benchmarking found the get()/get_ignoring_pending_unget() split in skip_whitespace() made long whitespace runs (e.g. indentation in pretty-printed JSON) 1.75x-3.2x SLOWER instead of faster, reproducible with both Apple Clang and GCC. Root cause: rewriting the loop from a plain do-while into an initial get() followed by a while-loop defeated the compiler's ability to keep the input adapter's read/end pointers in registers across iterations; both compilers instead reloaded them from memory on every character. The function split itself was not the problem (it still fully inlines); the loop's control-flow shape was. The fix keeps the same two-function structure but restores a do-while shape (guarded by an if for the "first char not whitespace" case), which lets both compilers hoist the pointers back into registers, matching or beating pre-#5490 performance. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Share the position-counter bump between get() and get_ignoring_pending_unget() Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Extract current_is_whitespace() to deduplicate skip_whitespace()'s two whitespace checks Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Use a raw string literal for the multi-line error-position test input Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Fix clang-tidy raw-string-literal finding and guard a new test against JSON_NOEXCEPTION The issue #5412 whitespace-skipping test added a check_error() helper that relies on catching json::parse_error to verify the exception message; under JSON_NOEXCEPTION, JSON_THROW aborts instead of throwing, which crashed ci_test_noexceptions (and cascaded into the other ci_cmake_options jobs). Guard the whole section with #if !defined(JSON_NOEXCEPTION), matching the existing pattern used by sibling tests in this file. Also switch one escaped string literal to a raw string literal to satisfy clang-tidy's modernize-raw-string-literal check. Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me> |
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Niels Lohmann
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faa35cc647 |
Skip integer conversion in accept()/SAX validation when the value is unused (#5484)
* Skip integer conversion in accept()/SAX validation when the value is unused lexer::scan_number() always converted every numeric token with strtoull()/strtoll() before returning, even though accept() (and any consumer using json_sax_acceptor) immediately discards the converted value. For value_unsigned/value_integer tokens whose digit count already guarantees the value fits into 64 bits, the conversion cannot change the accept/reject decision (such tokens are always finite and unconditionally accepted), so scan_number() can skip strtoull()/ strtoll() entirely in that case when the caller signals it does not need the value. Numbers with more digits keep using the exact, unmodified conversion path, so overflow reclassification to value_float (and the finiteness check on it) is unaffected. parse() and value_float handling are completely unchanged. Fixes #5411 Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Document why the digit-count fast path is safe regardless of number_unsigned_t/number_integer_t width Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Avoid temporary-string concatenation flagged by clang-tidy in the differential test Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me> |
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 Sahil_Kamate
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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> |
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 Dmitry
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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> |
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Niels Lohmann
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bacdabd176 |
Fix start_pos() for strings containing escape sequences (#5361)
The diagnostic position of a string value was derived by subtracting the
parsed value's length from the end position. Escape sequences make the
source token longer than the value it parses to, so the reported start
position landed inside the string, one byte off per escape sequence:
input: {"a":"\n\n\n\n\n\n"}
start_pos() == 11, so the reported range covered n\n\n\n"
instead of the documented "\n\n\n\n\n\n"
This contradicts the documented behavior of start_pos(), which is the
position of the opening quote, and it also corrupted the "(bytes N-M)"
part of JSON_DIAGNOSTICS exception messages. Strings with multi-byte
UTF-8 but no escapes were unaffected, which is why this went unnoticed.
Record the offset of the token in the lexer when it starts scanning and
use that, instead of reconstructing it from the parsed value. Booleans,
null and numbers already reported correct positions and are unchanged.
The new lexer member and accessor are compiled only when
JSON_DIAGNOSTIC_POSITIONS is enabled, which is already part of the ABI
tag, so the default build is unaffected.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
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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> |
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 Angadi56
|
dca9d49a33 |
reject out-of-range code points in UTF-32 wide-string input (#5348)
* reject out-of-range code points in UTF-32 wide-string input Signed-off-by: Angadi Yashaswini <angadi@digiscrypt.com> * remove useless cast to char_traits<char>::int_type Signed-off-by: Angadi Yashaswini <angadi@digiscrypt.com> --------- Signed-off-by: Angadi Yashaswini <angadi@digiscrypt.com> |
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Angadi56
|
68f0722a19 |
remove discarded array from parent object in end_array (#5342)
* remove discarded array from parent object in end_array Signed-off-by: Angadi Yashaswini <angadi@digiscrypt.com> * remove discarded scalar value from parent object in handle_value Signed-off-by: Angadi Yashaswini <angadi@digiscrypt.com> --------- Signed-off-by: Angadi Yashaswini <angadi@digiscrypt.com> |
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 tomatotomata
|
2222d386c9 | fix: check CBOR tagged subtype reads (#5339) | ||
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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> |
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  hum4nBeingandAJ369ninja
|
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> |
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 Yash Bavadiya
|
dd24e2dffd |
check all BSON reads and add an EOF check for booleans (#5332)
Signed-off-by: Yash Bavadiya <krbavadiya11@gmail.com> |
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 Patrick10199
|
868506dcc0 |
Fix CBOR half-float assertion bounds (#5335)
Signed-off-by: Patrick Armstrong <patrick@erpassistant.ai> |
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Angadi56
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9a3ebb9456 | validate BSON document size against the bytes read (#5287) | ||
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Angadi56
|
3565f40229 | reject negative UBJSON/BJData string length (#5284) | ||
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Angadi56
|
1c5a953de5 | reject unpaired UTF-16 surrogates in wide-string input (#5276) | ||
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Niels Lohmann
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c197feff81 | Extend memcpy fast path to sized sentinels (e.g. std::counted_iterator) (#5268) | ||
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Niels Lohmann
|
ca76c37650 |
Add iterator+sentinel tests and docs for binary deserializers (#5265)
* Add iterator+sentinel tests and docs for binary deserializers This commit extends the C++20 ranges support (iterator+sentinel pairs) to the binary format deserializers from_cbor, from_msgpack, from_ubjson, from_bjdata, and from_bson, matching what was already done for parse(), accept(), and sax_parse(). Changes: - Add istreambuf_sentinel helper to test_utils.hpp for EOF detection in tests - Add 5 new test cases that read binary files directly via std::istreambuf_iterator<char> + sentinel, without pre-buffering - Update documentation for all 5 from_* functions to document overload (3) with SentinelType parameter - All tests pass; verified against existing test suite data - Fix potential buffer over-read warning in heterogeneous iterator test Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Merge iterator+sentinel overloads and fix ambiguity/CI issues Address PR review feedback and CI failures: - Merge the separate same-type and sentinel-type iterator overloads of parse(), accept(), sax_parse(), and the five from_* binary deserializers into a single overload with SentinelType defaulted to IteratorType, as suggested in review. Applied the same simplification to the detail::input_adapter() free functions. - Fix a latent ambiguity: some compilers (e.g. GCC 4.8) unreliably SFINAE the operator!= detection for std::nullptr_t against container/string types, making calls like parse(s, nullptr, ...) ambiguous with the compatible-input overload. can_compare_ne now explicitly excludes std::nullptr_t as a SentinelType. - Use a named enable_if_t template parameter instead of an unnamed function parameter for the SFINAE guard, fixing a clang-tidy hicpp-named-parameter/readability-named-parameter failure. - Update parse.md, accept.md, sax_parse.md, and the five from_*.md pages to document the merged overload instead of separate (2)/(3) overloads, also fixing an over-160-char line that broke the documentation style_check CI job. - Rework the BSON iterator+sentinel test to parse a BSON file already present in the test suite instead of writing/deleting a temp file. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Fix -Wunneeded-internal-declaration for CustomSentinel in test CustomSentinel lives in an anonymous namespace (internal linkage), and the library's parse loop only ever evaluates the iterator-first direction (it != last), so the reversed-order friend operator!= was never referenced. Clang's -Weverything flags such unused internal declarations as an error. Drop the unused overload; the used direction is enough to satisfy can_compare_ne's either-order detection. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Fix clang-tidy hicpp-named-parameter and misc-const-correctness - Drop the unused reversed-order operator!= overload from utils::istreambuf_sentinel (only iterator != sentinel is ever evaluated) and name the remaining friend's sentinel parameter, fixing hicpp-named-parameter/readability-named-parameter. - Mark the istreambuf_iterator first/last helper variable const in the five binary-format sentinel tests, fixing misc-const-correctness. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Fix clang-tidy misc-const-correctness in heterogeneous sentinel test json_str is only read via .data()/.size() and never reassigned, so clang-tidy correctly flags it as const-able. Verified against the exact CI job (silkeh/clang:dev, ci_clang_tidy target) by running clang-tidy directly on this file plus the five binary-format sentinel tests touched by prior commits; all are now clean. Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me> |
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Niels Lohmann
|
b630f5e9c7 |
Fix container input_adapter SFINAE for lvalue-only ADL begin/end (#5260)
* Fix container input_adapter SFINAE for lvalue-only ADL begin/end (#111) The container overload of json::parse(c) / accept(c) / sax_parse(c, ...) silently dropped from overload resolution for user types whose ADL begin(T&) / end(T&) accepted only non-const lvalue references (a legitimate pattern matching std::begin semantics). This was because the detection code used std::declval<ContainerType>() which synthesized an rvalue, and the rvalue failed to bind to lvalue-only ADL functions. Fix by making both the outer input_adapter(ContainerType&&) and the factory's create(ContainerType&&) forwarding references, preserving the caller's value category and constness via reference collapsing. This ensures detection (std::declval) and actual use (std::forward) always match without needing decay/remove_reference. - Rewrite input_adapters.hpp container overload with forwarding refs - Add regression tests for lvalue-only non-const ADL begin/end - Add regression test for rvalue containers (no breakage) - Update API docs (parse, accept, sax_parse, from_*) to clarify that begin/end must match std::begin/std::end semantics - Add version history notes for 3.13.0 - Regenerate amalgamation Second-order effect: binary_reader.hpp's internal call to input_adapter(number_vector) now deduces iterator vs const_iterator based on the lvalue; functionally harmless (iterator_input_adapter is iterator-type-agnostic), verified via unit-ubjson/unit-bjdata tests. Closes remaining limitation from #4354 / PR #5218 (todo 106). Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Avoid strlen() in test container to fix Codacy CWE-126 flag Suppressing the strlen()-based CWE-126 warning with NOLINT/nosec comments only silenced clang-tidy and the standalone Flawfinder Action; Codacy's own analysis (which also flags this pattern and doesn't honor those suppression comments) still reported it as a new issue, plus flagged the near-duplicate begin/end pair as cloned code. Store the buffer's size explicitly in MyContainerNonConstADL instead of computing it via strlen() in end(), which removes the flagged pattern outright and also de-duplicates the struct from the existing MyContainer's char*-based begin/end pair. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Avoid trailing return type to satisfy clang-tidy fuchsia-trailing-return The forwarding-reference input_adapter(ContainerType&&) entry point was written with an auto/trailing-decltype return type, but this project's ci_clang_tidy job enables the fuchsia-trailing-return check as an error, which rejects it. The return type only depends on the template parameter ContainerType, not on the runtime parameter, so it can be written as an ordinary leading return type instead - no functional change. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Avoid C-style array in test to satisfy clang-tidy avoid-c-arrays clang-tidy's cppcoreguidelines/hicpp/modernize-avoid-c-arrays checks flagged the char raw_data[] declaration used to reproduce the lvalue-only non-const ADL begin/end scenario. Use std::string instead and take a mutable pointer via &raw_data[0], which is the standard way to get a non-const char* into a string's buffer under C++11 (std::string::data() only returns non-const in C++17 and later). Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me> |
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Niels Lohmann
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855f511db4 |
Fix stale Clang -Weverything suppression comments; drop -Wno-missing-noreturn (#5250)
* Fix stale Clang -Weverything suppression comments; eliminate -Wno-missing-noreturn cmake/clang_flags.cmake claimed -Wno-unsafe-buffer-usage was needed only for Doctest and that -Wno-missing-noreturn had "no way to silence... otherwise" (PR #4871, which never actually attempted a source fix). Neither held up under investigation (todo 130): - -Wno-unsafe-buffer-usage is pervasive (208 distinct sites across 19 files measured with clang trunk in silkeh/clang:dev), spanning the library's own low-level numeric/buffer code (to_chars, serializer, lexer, binary reader/writer, input adapters, json_pointer) as well as vendored Doctest itself (96 of the 208 sites). A source-level fix is not feasible at this scale; the comment now says so instead of blaming Doctest alone. - -Wno-missing-noreturn had exactly two real trigger sites, both genuinely and unconditionally non-returning: a test-only throwing allocator (tests/src/unit-allocator.cpp) and, previously undiscovered, wide_string_input_adapter::get_elements<T>() in include/nlohmann/detail/input/input_adapters.hpp. Verified this isn't a wider pattern by checking all 160 JSON_THROW call sites in the library for functions whose entire body is an unconditional throw. Annotated both ([[noreturn]] in the test file, since JSON_HEDLEY_NO_RETURN is #undef'd by the time test code runs; JSON_HEDLEY_NO_RETURN in the library file, its first real use anywhere in the codebase) and dropped the suppression entirely. single_include/nlohmann/json.hpp regenerated via `make amalgamate`; `make check-amalgamation` passes. Verified in Docker (silkeh/clang:dev, matching the ci_static_analysis_clang CI job): baseline builds clean, and the full 194-target test suite builds with zero warnings under the corrected CLANG_CXXFLAGS (-Wno-missing-noreturn no longer in the list). Also sanity-compiled and ran unit-allocator.cpp and unit-wstring.cpp on host Apple Clang to confirm behavior is unchanged. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Fix MSVC C4702 warning caused by JSON_HEDLEY_NO_RETURN on get_elements() PR #5250 annotated wide_string_input_adapter::get_elements<T>() with JSON_HEDLEY_NO_RETURN (it unconditionally throws). On MSVC this expands to __declspec(noreturn), and MSVC correctly determined that the code following its call in binary_reader.hpp is unreachable for that instantiation, firing C4702 under /W4 /WX in the msvc, msvc-vs2026, and msvc-arm64 Debug jobs. Clang doesn't flag this case, so the Docker verification for #5250 (which only checked Clang -Weverything) didn't catch it. This is the same warning class already tolerated for Release builds since PR #5216, where MSVC's optimizer independently found the same dead code after /Od was removed. Extend that existing /wd4702 suppression to Debug builds too, instead of reverting the noreturn annotation. Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me> |
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Niels Lohmann
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83c87cb9e0 | Read binary strings/blobs in bulk chunks with a memcpy fast path (#5233) | ||
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Niels LohmannandClaude Opus 4.8
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eed1587000 |
Reconstruct lexer diagnostics lazily for seekable input (#120) (#5234)
`lexer::get()` copied every scanned character into `token_string` on the whole successful-parse hot path, yet that buffer is consumed only by `get_token_string()` when rendering the "last read" fragment of a parse error. On well-formed input the per-byte copy (plus the `unget()` pop) is pure overhead that is always discarded. For seekable input adapters - random-access, single-byte iterators such as those backing `std::string`, `const char*`, and `std::vector<char>` - the offending token is now reconstructed on demand from the input when an error is reported, using a saved start offset, and the eager copy is skipped. Streaming adapters (file, istream, wide-string, and user-defined adapters) keep the eager copy; the strategy is chosen at compile time via `input_adapter_supports_seek`, so adapters without the capability are unaffected. Error messages are byte-for-byte identical across all adapters, verified by a new parity regression test. Microbenchmark (4 MB mixed JSON, parsed from a std::string): ~149 -> ~160 MB/s, about +8%. Signed-off-by: Niels Lohmann <mail@nlohmann.me> Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com> |
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Niels Lohmann
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c5b2b26fdc | 📝 fix docs (#5217) | ||
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Niels Lohmann
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f8eee1bb79 | Annotate unreachable comment-scanner switch paths to satisfy C26819 (#5071) | ||
 Ville Vesilehto
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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> |
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Niels Lohmann
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515d994acb |
📄 adjust year (#5044)
Signed-off-by: Niels Lohmann <mail@nlohmann.me> |
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Niels Lohmann
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54be9b04f0 | 📄 update REUSE (#4960) | ||
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Niels Lohmann
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30d27df61c |
Fix CI (#4871)
* 👷 fix CI Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 👷 fix CI Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 👷 fix CI Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 👷 fix CI Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 👷 fix CI Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 👷 fix CI Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 👷 fix CI Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 👷 fix CI Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 👷 fix CI Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 👷 fix CI Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 👷 fix CI Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 👷 fix CI Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 👷 fix CI Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 👷 fix CI Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 👷 fix CI Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me> |
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  David KilzerandDavid Kilzer
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d70e46bc65 |
🐛 add missing header to input_adapters.hpp (#4830)
Signed-off-by: David Kilzer <ddkilzer@apple.com> Co-authored-by: David Kilzer <ddkilzer@apple.com> |
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Niels Lohmann
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cf16c5ab9f | Use binary_t::value_type (#4805) | ||
  chirszandNiels Lohmann
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4b17f90f65 |
Add ignore_trailing_commas option (#4609)
Added examples and modified the corresponding documents and unit tests. Signed-off-by: chirsz-ever <chirsz-ever@outlook.com> Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com> |
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Niels Lohmann
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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> |
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Ville Vesilehto
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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> |
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Niels Lohmann
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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> |
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Niels Lohmann
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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> |
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Niels Lohmann
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1705bfe914 |
🔖 set version to 3.12.0 (#4727)
Signed-off-by: Niels Lohmann <mail@nlohmann.me> |
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Niels Lohmann
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b477d2b95e |
Suppress clang-analyzer-webkit.NoUncountedMemberChecker (#4701)
* 🚨 suppress clang-analyzer-webkit.NoUncountedMemberChecker Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 🚨 suppress invalid misc-const-correctness warnings Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 📝 add Clang 20/21 Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 🚨 suppress invalid misc-const-correctness warnings Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 🚨 suppress invalid misc-const-correctness warnings Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 🚨 suppress invalid misc-const-correctness warnings Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 🚨 suppress invalid misc-const-correctness warnings Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 🚨 suppress invalid misc-const-correctness warnings Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 🚨 suppress invalid misc-const-correctness warnings Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 🚨 suppress invalid misc-const-correctness warnings Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 🚨 suppress invalid misc-const-correctness warnings Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me> |
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Niels Lohmann
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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> |
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 Michael Valladolid
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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> |
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 Nebojša Cvetković
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2e50d5b2f3 | BJData optimized binary array type (#4513) | ||
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Michael Valladolid
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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 |
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  Sushrut ShringarputaleandSush Shringarputale
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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> |
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Niels Lohmann
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30cd44df95 |
Clean up CI (#4553)
* 💚 overwork cppcheck * 🔒 adjust permissions * 💚 fixes * 💚 fixes |
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Niels Lohmann
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1b9a9d1f21 |
Update licenses (#4521)
* 📄 update licenses * 📄 update licenses |
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 Tianyi Chen
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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 |
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Niels Lohmann
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ee32bfc1c2 |
Make SAX output locale-independent (#4505)
* 🐛 make SAX output locale-independent #4084 * ✅ add test * ✅ add test * ✅ add test * ✅ add test * ✅ add test * ✅ add test * 🐛 make SAX output locale-independent #4084 * 🐛 make SAX output locale-independent #4084 * 🐛 make SAX output locale-independent #4084 * 🐛 make SAX output locale-independent #4084 * 🐛 make SAX output locale-independent #4084 * 🐛 make SAX output locale-independent #4084 * 🐛 make SAX output locale-independent #4084 * 🐛 make SAX output locale-independent #4084 * 🐛 make SAX output locale-independent #4084 * 🐛 make SAX output locale-independent #4084 * 🐛 make SAX output locale-independent #4084 * 🐛 make SAX output locale-independent #4084 |
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  Stuart GormanandStuart Gorman
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f9f8c07792 |
fix: integer parsed as float when EINTR set in errno (#4506)
* fix: integer parsed as float when EINTR set in errno * chore: make amalgamate * chore: make pretty --------- Co-authored-by: Stuart Gorman <Stuart.Gorman@kallipr.com> |
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1f218e1074 |
Possible fix for #4485 (#4487)
* Possible fix for #4485 Throw's an exception when i is nullptr, also added a testcase for this scenario though most likely in the wrong test file.cpp * quick cleanup * Fix compile issues * moved tests around, changed exceptions, removed a possibly unneeded include * add back include <memory> for testing something * Ninja doesn't like not having a \n, at end of file, adding it back * update input_adapter file to deal with empty/null file ptr. * ran make pretty * added test for inputadapter * ran make amalgamate * Update tests/src/unit-deserialization.cpp Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com> * Update tests/src/unit-deserialization.cpp Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com> * Update input adapters.hpp with new includes * fix unabigious use of _, (there was a double declare) * did the amalagamate * rm duplicate includes * make amalgamate again * reorder * amalgamate * moved it above * amalgamate --------- Co-authored-by: Jordan <jordan-hoang@users.noreply.github.com> Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com> |
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Niels Lohmann
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1825117e63 |
Another desperate try to fix the CI (#4489)
* 🚨 fix warning * 💚 update actions * 🚨 fix warning * 🚨 fix warning * 🚨 fix warning * 💚 update actions * 💚 update actions * 🚨 fix warning * 🚨 fix warning * 💚 update actions * 🚨 fix warning * 💚 update actions * 💚 update actions * 💚 update actions * 🚨 fix warning * 🚨 fix warning * 🚨 fix warning * 🚨 fix warning * 💚 update actions * 💚 update actions * 🚨 fix warning * 💚 update actions * 💚 update actions * 💚 update actions * 💚 update actions * 💚 update actions |