Commit Graph
891 Commits
Author SHA1 Message Date
Niels Lohmann 0effbaa7a2 Fix clang-tidy 22 findings in the json_view headers
Silence bugprone-casting-through-void for the SSE loads (a reinterpret_cast
would trip -Wcast-align=strict), use auto for a cast initialiser, add
parentheses to a mixed expression, and name bugprone-std-namespace-modification
in the NOLINTs of the tuple_size/tuple_element specialisations.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-10 01:19:05 +02:00
Niels Lohmann 61e3d97bfd Keep the first of duplicate keys in the object hash index again
Lookups in objects with 128 members or more return the first member of a
repeated key again, like the linear search of smaller objects. This undoes
the code change of a69542046; its test now expects the first member from
lookups (with and without a table) and the last value from materialize()
and basic_json::parse().

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-09 23:33:31 +02:00
Niels Lohmann 42b5e4ac34 Merge branch 'json-view/13-view-dump' into json-view/16-view-simd
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-09 23:27:13 +02:00
Niels Lohmann 02f90bd307 Merge branch 'json-view/11-view-access' into json-view/13-view-dump
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-09 23:22:52 +02:00
Niels Lohmann 32853d2c90 Do not shrink the output of dump()
finish() copied the whole output when the buffer was more than twice as
large as the result (citm dump +11%). The tighter source_extent()
estimate already keeps the buffer of a small value small.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-09 23:22:34 +02:00
Niels Lohmann 13d2b3e224 Return the first member of duplicate keys from lookups again
Looking up the last member of a duplicate key cannot stop at a match, so
every lookup scanned the whole object (1.6 to 3.4 times slower for small
objects). operator[](key), at, find, value, contains, count, and JSON
pointer resolution return the first member again, as yyjson and simdjson
do; materialize() and get<map>() keep the last value, as parse().

The documentation says so in the feature page and on each lookup page,
and explains how to get the value parse() would give. The integer index
templates and the discarded chaining of operator[] stay.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-09 23:20:51 +02:00
Niels Lohmann a69542046c Keep the last of duplicate keys in the object hash index
Lookups in objects with 128 members or more now return the last member of
a repeated key, like the linear search of smaller objects and like
materialize() and basic_json::parse(). build_object_index let the first
occurrence win, so the same text gave different results depending on the
size of the object.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-09 17:13:26 +02:00
Niels Lohmann 66e875895f Merge branch 'json-view/13-view-dump' into json-view/16-view-simd
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-09 17:06:43 +02:00
Niels Lohmann bd0fc072fc Merge branch 'json-view/11-view-access' into json-view/13-view-dump
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-09 16:58:15 +02:00
Niels Lohmann 1d76bc9750 Merge branch 'json-view/08-view-builder' into json-view/11-view-access
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-09 16:47:20 +02:00
Niels Lohmann 63dc0dce12 Merge branch 'json-view/23-zmij' into json-view/08-view-builder
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-09 16:40:42 +02:00
Niels Lohmann 581efc817d Merge branch 'json-view/02b-float-parser' into json-view/23-zmij
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-09 16:37:56 +02:00
Niels Lohmann e3dafe1dba Remove the unused legacy_discarded_value_comparison from abi_config
Nothing reads it: the view does not compare values.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-09 16:30:12 +02:00
Niels Lohmann 078903cbb9 State the exact input size limit of json_document
The check rejects inputs of 0xFFFFFFF0 bytes or more, but the exception
message and the documentation said 4 GiB. Name the limit once
(max_input_size), and state 4 GiB minus 16 bytes in the message and the
documentation. Test the limit with a container that only claims the size.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-09 16:30:00 +02:00
Niels Lohmann a1b5b348ab Check the node array size for overflow
reserve(n) and the growth of the index computed n * sizeof(node) without a
check, which wraps around on 32-bit targets for inputs of about 1 GiB and
allocates a too small array. Throw std::bad_alloc for a count beyond the
address space and clamp the growth step to it.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-09 16:28:19 +02:00
Niels Lohmann 320a463af7 Store node integers by halves on big-endian targets
The non-little-endian path of the node writer wrote the integer's native
word over len and next, so len got the high half there. Compose and split
the value explicitly (len is the low half, next the high half); the
little-endian path stays a plain memcpy.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-09 16:26:32 +02:00
Niels Lohmann beb83ae03b Copy const rvalue strings and document the accepted inputs
json_document::parse(std::move(const_string)) failed to compile with
"no matching read_kind": only a non-const rvalue std::string can be moved
from. Treat a const rvalue as a copied byte container.

parse() does not accept everything BasicJsonType::parse() does: a FILE*
and pointers to or arrays of wide characters are rejected at compile time.
List the supported inputs instead.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-09 16:12:11 +02:00
Niels Lohmann c7df23666f Make view lookups last-wins and chained access safe
* Lookups (operator[], at, find, contains, count, value, JSON pointers)
  return the last member of a duplicate key, as materialize() and
  parse() keep it.
* operator[] on a discarded view returns a discarded view instead of
  throwing, so v["a"]["b"] is safe for a missing "a".
* operator[] and at() take any integer type (not only int and size_t),
  fixing ambiguous calls with unsigned, long, std::int64_t, ...
* Fix the operator[] documentation, which claimed a discarded view for
  a type mismatch where type_error.305 is thrown.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-09 16:11:33 +02:00
Niels Lohmann 38702df4f9 Document the hash index number in node::extra
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-09 16:11:29 +02:00
Niels Lohmann eba895c224 Use the portable string scan on non-x86 targets that define __SSE2__
WebAssembly with -msse2 defines __SSE2__, but has no <cpuid.h> or x86 intrinsics headers.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-09 16:11:28 +02:00
Niels Lohmann 331615d3de Bound the probe length of the large-object hash index
The key hash is not seeded, so keys chosen to collide made building the table quadratic (20,000 colliding keys took 470 ms to parse). A key may now sit at most 64 slots from its home slot; if a key would sit further away, the table is dropped and the object is searched linearly. Lookups stop after the same distance.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-09 16:11:25 +02:00
Niels Lohmann 2ba331e4d0 Size the dump buffer of a small value by its own extent
The source extent of a value was read from the next node, falling back to the rest of the document when that node held a decoded string. dump() of a small value could thus allocate a buffer as large as the document. Skip a few such nodes, cap the fallback estimate, and shrink a buffer that is much larger than its output.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-09 16:11:14 +02:00
Niels Lohmann c006db93d4 Reject integer lengths in json_document::parse
parse(ptr, len) compiled: len converted to allow_exceptions, and ptr was
read as a C string, past the end of a buffer without a terminating NUL.
Delete the overloads of parse, parse_copy, accept, and read that take an
integer other than bool where the flags are expected.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-09 16:10:11 +02:00
Niels Lohmann 35b28d4918 Credit Zmij's authors in to_chars.hpp, the README, and the license page
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-09 16:07:44 +02:00
Niels Lohmann 86feea50ab Select the Zmij conversion by a trait, not by the double overload
The non-template overloads for double asserted binary64 doubles wherever json.hpp was included, so the library no longer compiled where double is not IEEE 754 binary64 (AVR, -fshort-double). A trait now picks Zmij for any binary64 type, including a long double of that format (MSVC, Apple Arm), and Grisu2 for the others. Remove the unused write_short_decimal, powers_of_ten_16, zmij::decimal, zmij::to_decimal, and shortest_digits(double).

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-09 16:07:43 +02:00
Niels Lohmann 0e729be261 Load string scan words with memcpy and use MSVC bit-scan intrinsics
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-09 16:01:48 +02:00
Niels Lohmann 1ec2d710f7 Merge branch 'json-view/13-view-dump' into json-view/16-view-simd
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-08 16:39:42 +02:00
Niels Lohmann 8860bf6f3a Merge branch 'json-view/11-view-access' into json-view/13-view-dump
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-08 16:39:40 +02:00
Niels Lohmann 7852da2bc2 Merge branch 'json-view/08-view-builder' into json-view/11-view-access
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-08 16:39:37 +02:00
Niels Lohmann 0012f65f60 Merge branch 'json-view/23-zmij' into json-view/08-view-builder
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-08 16:39:35 +02:00
Niels Lohmann 4c43e03d40 Merge CI fixes into json-view/23-zmij
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-08 16:39:25 +02:00
Niels Lohmann d22193a8b6 Fix CI findings in the Zmij writer and its tests
- bit_ops.hpp: include macro_scope.hpp (JSON_HEDLEY_ALWAYS_INLINE); fixes IWYU
- to_chars.hpp: C4100 for the unused parameter in release builds, clang-tidy
  sign comparison, cpplint runtime/int, GCC -Wstrict-overflow (unsigned abs)
- unit-to_chars.cpp: parse with the library instead of strtod (MinGW's strtod
  rounds some 16/17 digit inputs wrongly); no floating-point std::to_chars
  with icpc

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-08 16:33:32 +02:00
Niels Lohmann 4f1c34e44d Merge branch 'json-view/13-view-dump' into json-view/16-view-simd
Signed-off-by: Niels Lohmann <mail@nlohmann.me>

# Conflicts:
#	include/nlohmann/detail/view/document_data.hpp
#	single_include/nlohmann/json_view.hpp
2026-10-08 16:29:14 +02:00
Niels Lohmann 5db2fa633c Merge branch 'json-view/11-view-access' into json-view/13-view-dump
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-08 16:27:26 +02:00
Niels Lohmann acde46421b Merge branch 'json-view/08-view-builder' into json-view/11-view-access
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-08 16:27:24 +02:00
Niels Lohmann 63396cbe00 Merge branch 'json-view/23-zmij' into json-view/08-view-builder
Signed-off-by: Niels Lohmann <mail@nlohmann.me>

# Conflicts:
#	Makefile
#	meson.build
2026-10-08 16:26:33 +02:00
Niels Lohmann d9a0844723 Fix document_data for old Clang (3.4-3.6)
Drop the empty braced NSDMIs of the std::string members: old Clang
rejects the defaulted constructor when it is used by a member
initializer before the end of the class definition.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-08 16:25:45 +02:00
Niels Lohmann 22b82b487b Merge branch 'json-view/02b-float-parser' into json-view/23-zmij
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-08 16:25:42 +02:00
Niels Lohmann 9c7eb12918 Fix GCC module build and MSVC C4127 in the json_view SIMD code
GCC ignores the target attribute in modules, so the SSSE3 dispatch is
disabled for the module interface (the check stays portable, SSE2 is kept).
Make the 8-vs-16 byte unrolling condition in scan_string_run a
preprocessor/template split to avoid a constant condition (C4127).

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-08 16:23:21 +02:00
Niels Lohmann 43c75bef51 Merge branch 'develop' into json-view/02b-float-parser
Signed-off-by: Niels Lohmann <mail@nlohmann.me>

# Conflicts:
#	tests/src/unit-class_lexer.cpp
2026-10-08 16:19:06 +02:00
Suyog Verma a269794db7 Use MSVC intrinsics for full multiplication (#5782)
* Use MSVC intrinsics for full multiplication

Signed-off-by: Suyog Verma <suyogverma0057@gmail.com>

* Fix formatting in unit-class_lexer

Signed-off-by: Suyog Verma <suyogverma0057@gmail.com>

* Address review feedback

Signed-off-by: Suyog Verma <suyogverma0057@gmail.com>

---------

Signed-off-by: Suyog Verma <suyogverma0057@gmail.com>
2026-10-08 08:49:32 +02:00
Niels Lohmann ad715372bf Merge branch 'json-view/13-view-dump' into json-view/16-view-simd
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-07 20:26:50 +02:00
Niels Lohmann c39680779c Merge branch 'json-view/11-view-access' into json-view/13-view-dump
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-07 20:26:47 +02:00
Niels Lohmann dfdd69d234 Merge branch 'json-view/08-view-builder' into json-view/11-view-access
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-07 20:26:44 +02:00
Niels Lohmann 33b7b30d06 Merge branch 'json-view/23-zmij' into json-view/08-view-builder
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-07 20:26:42 +02:00
Niels Lohmann cb3c0177ed Merge branch 'json-view/02b-float-parser' into json-view/23-zmij
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-07 20:26:39 +02:00
Niels Lohmann 39d34f30ba Merge branch 'develop' into json-view/02b-float-parser
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-07 20:26:13 +02:00
Niels Lohmann 88ddacb84b Fix CI warnings in own float parser
- pow5_table.hpp: pow5_128_largest_power was unused in this branch's
  own code (GCC -Werror=unused-const-variable); tie it to the table
  size with a static_assert instead of removing it, since a later
  branch in the stack (json-view/23-zmij) uses it.
- number_parse.hpp: rename the local variable `copy` to `buffer` to
  satisfy cpplint's build/include_what_you_use check.
- unit-class_lexer.cpp: extend the NOLINT list on the seeded mt19937
  with bugprone-random-generator-seed, and parenthesize
  `8 * sizeof(Bits) - 1` for clang-tidy.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-07 20:26:12 +02:00
Niels LohmannandAfonso Januário a5f5d3059b Make std::hash<basic_json> consistent with operator== for numbers (#5772)
* Make std::hash<basic_json> consistent with operator== for numbers

operator== converts between number_integer, number_unsigned, and
number_float before comparing, so json(0), json(0U), and json(0.0)
all compare equal. hash() folded the specific value_t into the
result for each of the three numeric cases, giving each a distinct
hash and breaking the standard Hash requirement that a == b implies
hash(a) == hash(b). A std::unordered_set could therefore hold all
three as separate elements even though they compare equal.

hash() now treats all three numeric variants the same way: it
converts the value to number_float_t and combines it with a single
shared type tag, so any two numbers operator== considers equal hash
identically regardless of which internal type actually holds them.

Updated the accompanying test to check this consistency directly
(including via an actual unordered_set) instead of asserting that 0,
0U, and 0.0 hash differently, since that assumption was the bug.
Also corrected the function's own doc comment and the std::hash API
docs, which described the old behavior as intended.

Fixes #5400

Signed-off-by: Afonso Januário <afonso-januario@hotmail.com>
Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Remove now-unused number_integer_t/number_unsigned_t typedefs in hash()

Merging the three numeric branches into one that only reads
number_float_t left these two aliases unused, which several CI
configurations treat as a build error under -Wunused-local-typedefs.

Signed-off-by: Afonso Januário <afonso-januario@hotmail.com>
Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Mark the unordered_set in the hash regression test const

clang-tidy's misc-const-correctness check flagged it: the set is
never mutated after construction, only read via size().

Signed-off-by: Afonso Januário <afonso-januario@hotmail.com>
Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Normalize -0.0 in number hashes and test range ends

operator== compares numbers exactly since #5459, so equal numbers
share one value and convert to the same number_float_t. Update the
comment accordingly, map -0.0 to 0.0 before hashing (std::hash need
not do that), and test -0.0 and the ends of the integer ranges. Show
hash(0.0) in the docs example and note the change in the version
history.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Clarify hash documentation after review

- Say "may hash differently" for null, false, and numbers, since a
  collision across types is possible.
- Name the storage types (signed integer, unsigned integer,
  floating-point number) instead of example literals.
- Explain that the hash survives converting an integer to
  number_float_t but not the lossy conversion back, and that unequal
  numbers may share a hash.
- State that the example hash values are illustrative only and vary by
  platform, compiler, compiler version, and library version.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

---------

Signed-off-by: Afonso Januário <afonso-januario@hotmail.com>
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
Co-authored-by: Afonso Januário <afonso-januario@hotmail.com>
2026-10-07 19:18:51 +02:00
43fe8928e1 Stop binary writers overflowing the stack on deep values (#5781)
* Stop binary writers overflowing the stack on deep values

to_cbor, to_msgpack, and to_ubjson recurse once per nesting level.
The parser is iterative, so a value the library accepts can crash on
the way back out.

Keep the existing recursive path for the first 128 levels and finish
anything deeper on a heap stack. Output is unchanged. BSON is left
alone because its extra size walk is a separate change.

Rebased onto the value-type output sink. The heap frames now initialize
every member, which is what -Weffc++ was rejecting.

See #5392.

Signed-off-by: ayush-singh-0601 <singhayush062006@gmail.com>
(cherry picked from commit cf65ac438f)
Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Redesign the iterative binary writers around a shared recursion depth limit

Address the open review on the non-recursive CBOR/MessagePack/UBJSON/BJData
writers (#5518):

- Delete the CBOR array/object prefix helpers; both the recursive and
  iterative paths call write_cbor_head(), which already existed on develop.
- MessagePack: share one write_msgpack_array_prefix()/write_msgpack_object_prefix()
  helper per container kind between the recursive and iterative paths, both
  going through to_msgpack_length() so an over-long container throws
  out_of_range.412 identically either way.
- Reuse detail::recursion_depth_limit() instead of a separate constant, the
  same bound serializer::dump() and write_bson_document() already use.
- Redesign the frames after bson_frame/dump_frame: only a container with
  elements is ever pushed, its header is written at the point it is pushed,
  and the iterator is set in the frame's constructor instead of a
  default-then-assign two-step with a since-removed "started" flag. The
  UBJSON frame keeps only the value pointer, the per-element prefix_required
  flag, and the iterator; write_closer and is_object are no longer stored,
  since the former is always !use_count (use_count is constant for the whole
  document) and the latter follows from value->is_object().
- Factor the BJData ND-array shape check into is_bjdata_ndarray(), used by
  both the recursive object case and the iterative pushing logic.
- Give the frame classes the GCC -Weffc++ treatment already used for
  diff_frame: a noexcept converting constructor plus the five special members
  defaulted with no explicit noexcept.
- Fix two @ref self-references in write_cbor/write_msgpack/write_ubjson's own
  doc comments to point at the public to_cbor/to_msgpack/to_ubjson/to_bjdata
  API instead.
- The iterative object-key write for CBOR/MessagePack now runs the same
  strict-mode check_utf8() against the parent object as diagnostics context
  that the recursive path already ran, so the two paths raise identical
  diagnostics across the switch-over.
- Rewrite the tests: round trips instead of a bare size check, byte-exact
  comparisons against the recursive output at depths around the bound, a
  deep object and a BJData ND-array past the bound, a deep discarded value
  (type_error.321), and the OSS-Fuzz 566583014 CBOR/MessagePack regression.

BSON is unaffected by this change; it already walks its documents
iteratively and is covered separately by #5553.

Co-authored-by: ayush-singh-0601 <179524189+ayush-singh-0601@users.noreply.github.com>
Signed-off-by: Niels Lohmann <mail@nlohmann.me>

---------

Signed-off-by: ayush-singh-0601 <singhayush062006@gmail.com>
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
Co-authored-by: ayush-singh-0601 <singhayush062006@gmail.com>
Co-authored-by: ayush-singh-0601 <179524189+ayush-singh-0601@users.noreply.github.com>
2026-10-07 19:18:20 +02:00