Commit Graph

5327 Commits

Author SHA1 Message Date
Niels Lohmann
1fdef286dc Merge branch 'json-view/22-view-dump-fast' into json-view/23-zmij
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 10:29:33 +02:00
Niels Lohmann
650f3c091e Merge branch 'json-view/21-images' into json-view/22-view-dump-fast
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 10:29:25 +02:00
Niels Lohmann
4dd4505e1c Merge branch 'json-view/20-edit-structure' into json-view/21-images
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 10:29:17 +02:00
Niels Lohmann
d3ba92d4fb Merge branch 'json-view/19-edit-set' into json-view/20-edit-structure
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 10:29:07 +02:00
Niels Lohmann
89d6a7c2b5 Merge branch 'json-view/18-view-object-index' into json-view/19-edit-set
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 10:28:57 +02:00
Niels Lohmann
95c8d2aa46 Merge branch 'json-view/16-view-simd' into json-view/18-view-object-index
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 10:28:52 +02:00
Niels Lohmann
d38f5f111f Merge branch 'json-view/15-view-bench' into json-view/16-view-simd
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 10:28:48 +02:00
Niels Lohmann
057c86de8c Mark compare.py's subprocess and download calls for Bandit
The commands are argument lists the script builds itself, and the
downloads are pinned https URLs whose SHA-256 is checked.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 10:28:47 +02:00
Niels Lohmann
448a90909e Merge branch 'json-view/14b-view-float-layout' into json-view/15-view-bench
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 10:27:46 +02:00
Niels Lohmann
d9e4155ba1 Merge branch 'json-view/14-view-compare' into json-view/14b-view-float-layout
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 10:27:39 +02:00
Niels Lohmann
7130880754 Merge branch 'json-view/13-view-dump' into json-view/14-view-compare
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 10:27:30 +02:00
Niels Lohmann
89bf08760f Merge branch 'json-view/12-view-values' into json-view/13-view-dump
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 10:27:23 +02:00
Niels Lohmann
b1595c1b40 Merge branch 'json-view/11-view-access' into json-view/12-view-values
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 10:27:13 +02:00
Niels Lohmann
3d6d610fdc Merge branch 'json-view/10-view-document' into json-view/11-view-access
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 10:27:03 +02:00
Niels Lohmann
134b2f0efe Mark json_view.hpp's read() and strlen as Flawfinder false positives
json_document::read is a member function, not POSIX read(), and the C
string overload requires null-terminated input like json::parse.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 10:27:01 +02:00
Niels Lohmann
dddb2d6e43 Merge branch 'json-view/08-view-builder' into json-view/10-view-document
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 10:26:20 +02:00
Niels Lohmann
b59fc6c902 Mark string_ref's strlen as a Flawfinder false positive
string_ref(const char*) requires a null-terminated string, like
std::string_view's constructor.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 10:26:18 +02:00
Niels Lohmann
babae3f35d Merge branch 'json-view/22-view-dump-fast' into json-view/23-zmij
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 10:20:16 +02:00
Niels Lohmann
b3ce6fcce3 Merge branch 'json-view/21-images' into json-view/22-view-dump-fast
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 10:20:14 +02:00
Niels Lohmann
cff2af5966 Merge branch 'json-view/20-edit-structure' into json-view/21-images
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 10:20:12 +02:00
Niels Lohmann
ad248a3290 Merge branch 'json-view/19-edit-set' into json-view/20-edit-structure
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 10:20:10 +02:00
Niels Lohmann
db73471df4 Merge branch 'json-view/18-view-object-index' into json-view/19-edit-set
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 10:20:08 +02:00
Niels Lohmann
c6ac5c85c2 Merge branch 'json-view/16-view-simd' into json-view/18-view-object-index
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 10:20:06 +02:00
Niels Lohmann
0e57b3fb28 Merge branch 'json-view/15-view-bench' into json-view/16-view-simd
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 10:20:04 +02:00
Niels Lohmann
d575be3e55 Merge branch 'json-view/14b-view-float-layout' into json-view/15-view-bench
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 10:20:02 +02:00
Niels Lohmann
94c518f94d Merge branch 'json-view/14-view-compare' into json-view/14b-view-float-layout
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 10:19:59 +02:00
Niels Lohmann
76ce7e2c84 Merge branch 'json-view/13-view-dump' into json-view/14-view-compare
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 10:19:57 +02:00
Niels Lohmann
5277335a9e Merge branch 'json-view/12-view-values' into json-view/13-view-dump
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 10:19:55 +02:00
Niels Lohmann
05b6cd0892 Merge branch 'json-view/11-view-access' into json-view/12-view-values
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 10:19:53 +02:00
Niels Lohmann
95d10dab70 Merge branch 'json-view/10-view-document' into json-view/11-view-access
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 10:19:51 +02:00
Niels Lohmann
371a8a3d9f Merge branch 'json-view/08-view-builder' into json-view/10-view-document
Signed-off-by: Niels Lohmann <mail@nlohmann.me>

# Conflicts:
#	Makefile
#	cmake/ci.cmake
2026-10-01 10:19:49 +02:00
Niels Lohmann
cb51f80e34 Merge branch 'json-view/04-unicode-escapes' into json-view/08-view-builder
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 10:18:33 +02:00
Niels Lohmann
ae01d57694 Merge branch 'json-view/03-string-scan' into json-view/04-unicode-escapes
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 10:18:33 +02:00
Niels Lohmann
6a757ca675 Merge branch 'json-view/02b-float-parser' into json-view/03-string-scan
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 10:18:33 +02:00
Niels Lohmann
9d44e3f359 Merge branch 'develop' into json-view/02b-float-parser
Conflicted only in tests/src/unit-class_lexer.cpp, where develop's #5737
lint fix (CAPTURE(x); -> CAPTURE(x)) collided with this PR's rewrite of
the Eisel-Lemire float tests; kept the PR's new tests and applied the
lint-fixed CAPTURE style. single_include regenerated via make amalgamate.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 08:53:02 +02:00
Niels Lohmann
e400780533 Re-amalgamate single_include (#5745)
* Re-amalgamate single_include

#5737 changed 13 headers under include/ but merged without the matching
single_include/nlohmann/json.hpp update, so the amalgamated header still
had, among others, the GCC C++20 -Wignored-attributes pragma block and
the clang -Wdocumentation push/pop that #5737 removed, the forwarding
from_json tuple/array helpers it replaced with const references, and
lacked the output_adapter char_traits changes it added.

Regenerated with `make amalgamate` (astyle 3.4.13). The diff is exactly
`git diff b54ed188e e5a89d671 -- include/` (164+/95-); json_fwd.hpp and
json_literals.hpp were already up to date.

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

* Run the amalgamation check on pushes to develop

#5737 was merged 39 seconds after its last push, while its own
check_amalgamation run was still queued (earlier runs had been
cancelled by the concurrency group), so the stale single_include
reached develop without any failing check.

Also run the check on pushes to develop, without cancelling in-progress
develop runs. The "save" job (PR number/author for the comment
workflow) only runs for pull requests, the checkout falls back to
github.sha, and comment_check_amalgamation.yml only comments for
PR-triggered runs, since push runs have no PR and no "pr" artifact.

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 08:09:34 +02:00
Niels Lohmann
9d88ead578 Clarify that the strtold fallback substitutes the locale's decimal point
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 07:40:37 +02:00
Niels Lohmann
e5a89d671f Fix lint debt: enum-macro NOLINTs, doctest as SYSTEM, no-op analyzer (#5737)
* Drop stale LCOV_EXCL_LINE from the json_pointer out_of_range.410 throw

The comment said the size_type overflow check in array_index() is only
triggered on special platforms like 32-bit, and the throw was excluded
from coverage. On 64-bit platforms the check is true for SIZE_MAX
itself, and unit-json_pointer.cpp has asserted that case four times
since #5395, so the line is executed in the coverage job. Reword the
comment and remove the exclusion marker so the coverage report notices
if the tests stop reaching it.

Part of #5725

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

* Name all three C-array check aliases in the enum-macro NOLINTs

NLOHMANN_JSON_SERIALIZE_ENUM(_STRICT) suppressed the c-array warning
under modernize-avoid-c-arrays only, but clang-tidy emits the same
diagnostic under the aliases cppcoreguidelines-avoid-c-arrays and
hicpp-avoid-c-arrays too. Any user running those checks got a false
positive at every macro expansion, and our own tests needed a local
NOLINT at each call site to work around it.

Name all three aliases in the four macro comments instead, and drop
the now-redundant c-array names from the five test call-site NOLINTs.
Comment-only change; behavior, the public API, and the ABI do not
change. Ran make amalgamate.

Part of #5725

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

* Include doctest as a SYSTEM directory instead of disabling warnings for all tests

test_main added -Wno-deprecated and -Wno-float-equal as PUBLIC compile
options for every non-MSVC compiler, so they were applied to every
translation unit, library headers included, and silenced the CI
warnings meant to check the library's own -Wfloat-equal pragmas. The
only code that actually needed the suppression was the vendored
doctest.h, which was included as a normal (non-SYSTEM) directory.

Include thirdparty/doctest as SYSTEM for test_main, matching what
tests/abi/CMakeLists.txt already does, and drop the two suppressions
from both targets. Verified locally that unit-comparison,
unit-conversions and unit-constructor1 compile clean with
-Werror -Weverything and doctest as -isystem, and that CMake still
configures with JSON_BuildTests=ON.

Part of #5725

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

* Remove the no-op ci_clang_analyze target

ci_clang_analyze configured the build with the real compiler and only
then wrapped ninja with scan-build. scan-build intercepts compiles by
overriding CC/CXX, but build.ninja already had the compiler path baked
in from the configure step, so every run bypassed the analyzer: CI
logs show "No bugs found" after a normal build, never an analysis.
The job also used Debian's frozen clang-tools-14 rather than the
image's own clang, and CLANG_ANALYZER_CHECKS still named three
valist.* checkers that current clang merged into security.VAList.

ci_clang_tidy already runs every clang-analyzer-* check (via
.clang-tidy's "Checks: '*'") with warnings as errors, so nothing is
lost by removing the dead job. Delete ci_clang_analyze,
CLANG_ANALYZER_CHECKS and the SCAN_BUILD_TOOL lookup from
cmake/ci.cmake, drop it from the ubuntu.yml ci_static_analysis_clang
matrix, and drop the now-unused clang-tools apt package (iwyu stays
for ci_single_binaries). Reword quality_assurance.md and
assurance_case.md, which described the dead job as a working control,
to say the Clang Static Analyzer checks run through clang-tidy.

Verified that `cmake -DJSON_CI=ON` still configures cleanly and that
ci_clang_analyze no longer appears in the generated build or in any
CMake/workflow file.

Part of #5725

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

* Re-enable portability-template-virtual-member-function; remove redundant forwards

.clang-tidy disabled three checks "to get the CI going" (#4489,
2024-11-13): portability-template-virtual-member-function,
bugprone-use-after-move and its alias hicpp-invalid-access-moved.

portability-template-virtual-member-function only flagged
output_stream_adapter::write_character/write_characters; annotate
both with NOLINT and re-enable the check.

bugprone-use-after-move flagged several double forwards that have no
effect at runtime:
- from_json.hpp calls std::forward<BasicJsonType>(j).at(Idx) inside
  pack expansions; at() has no ref-qualified overloads and always
  returns an lvalue reference, so the forward is a no-op. Replace with
  plain j.at(Idx) in all four places.
- the move constructor forwards the whole object to its base class
  and then reads other's members. That is item 9 of #5724 (together
  with its cppcheck suppressions) and is left to that change.
- input_adapters.hpp forwards the container twice on purpose, so the
  begin/end iterator types match adapter_type; annotate with NOLINT
  and a comment instead of changing behavior.

The check still flags the move constructor (see above) and two sites
in at(KeyType&&) (both overloads, json.hpp, in the throw's
string_t(std::forward<KeyType>(key)) after
find(std::forward<KeyType>(key))). Open PR #5689 rewrites that hunk,
so bugprone-use-after-move (and hicpp-invalid-access-moved)
stay disabled for now, with a comment explaining why; re-enable them
once #5689 and the #5724 move-constructor change have landed.

Also resolve the portability-avoid-pragma-once TODO: single_include
never has #pragma once (amalgamate.py strips it) and every supported
compiler accepts it in include/, so keep it disabled with an
explanatory comment instead of a TODO. Fix the stale "json.hpp,
around line 1265" comment in unit-class_parser.cpp, which now points
at the move constructor's actual line.

Behavior, the public API and the ABI do not change. Verified with
clang-tidy 22.1.8 that portability-template-virtual-member-function
now reports nothing, that bugprone-use-after-move/
hicpp-invalid-access-moved report only the known at(KeyType&&) and
move-constructor sites, and that unit-custom-base-class, unit-constructor1,
unit-conversions, unit-element_access2, unit-class_parser and
unit-diagnostic-positions (JSON_DIAGNOSTIC_POSITIONS=1) compile
under ASan/UBSan and pass with the same assertion counts as before.
Ran make amalgamate.

Part of #5725

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

* Fix stale and malformed NOLINT comments

json_sax.hpp named "-warnings-as-errors" in the NOLINT list on the two
JSON_ASSERT(false) lines; that is the suffix clang-tidy appends to a
diagnostic tag under WarningsAsErrors, not a check name, and every
other JSON_ASSERT(false) omits it.

unit-capacity.cpp carried 30 "// NOLINT(misc-const-correctness)"
comments on "json j = ...;" declarations that are all used with
non-const members afterwards, so the check has nothing to report
there.

unit-constructor2.cpp used a blanket "// NOLINT: access after move is
OK here" on a use-after-move that hides every check on the line;
naming bugprone-use-after-move and hicpp-invalid-access-moved keeps
the intent once those checks are re-enabled (#5724).

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

#5725 item 10

* Remove stale .clang-tidy entries

-google-runtime-references disabled a check that neither clang-tidy
22.1.8 nor 23.1.2 lists under --list-checks -checks='*'; it was
removed upstream. The commented-out HeaderFilterRegex line has been
unused since the active HeaderFilterRegex was introduced in #2561
(2021).

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

#5725 item 11

* Remove the GCC C++20 -Wignored-attributes pragma in json.hpp

The pragma (added in #5164) claimed to work around the C++ modules
redefinition errors of #5103, but #5103 is about hard errors (e.g.
"redefinition of std::__is_constant_evaluated()", conflicting
std::integral_constant) that ignoring a warning cannot suppress; they
are traced to GCC PR 124430 and reproduce with <map> or <string>
instead of json.hpp too. A GCC 16.2 -std=gnu++20 -fmodules build
following #5103's repro steps still fails with the pragma in place,
and a build of all test TUs with GCC_CXXFLAGS (which enable
-Wignored-attributes) and the pragma removed produces no such
warning. The block only hid a warning class from GCC C++20 users
while suggesting #5103 was handled.

Overlaps #5610, whose hunks touch the closing half of this pragma to
insert the json_literals.hpp include.

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

#5725 item 9

* Fix stale doxygen comments hidden by the -Wdocumentation pragma

macro_scope.hpp ignores -Wdocumentation and -Wdocumentation-unknown-command
for the whole library, which also hides genuine documentation mistakes:

- detail::unescape() documented "@return unescaped string" but returns
  void and unescapes its argument in place; reworded to
  "@param[in,out] s string to unescape in place" and dropped the
  bogus @return.
- basic_json::get()'s copy-conversion overload wrote "converted to
  @tparam ValueType" inside @return, which Doxygen and Clang parse as
  a second, malformed @tparam; changed to "@a ValueType", matching the
  two other get() overloads a few lines above that already use it.

This narrows the gap the -Wdocumentation pragma needs to cover; fully
replacing the Doxygen-only commands it also hides (item 2c) is left
for after #5267.

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

#5725 item 2

* Fix -Wextra-semi-stmt at its actual source, not assert()

clang_flags.cmake blamed the global -Wno-extra-semi-stmt on assert(),
but assert() expands to an expression under glibc and libc++ and does
not trigger this warning. unit-assert_macro.cpp overrides JSON_ASSERT
with "{if (!(x)) ++assert_counter; }", a bare block followed by a
semicolon at every JSON_ASSERT(...) call site in the library; that
was the actual source of 151 of the 208 -Wextra-semi-stmt sites found
in a Clang 22 -Weverything sweep of the test suite with the flag
removed. Switched to the standard do/while(false) macro idiom, which
does not expand to a statement-plus-semicolon, and corrected the
comment to name the remaining source instead: vendored Doctest's
CAPTURE(x) shim, which already ends in a semicolon.

Verified with clang++ -Wextra-semi-stmt (plus the file's other CI
ignores) that unit-assert_macro.cpp now compiles without any
-Wextra-semi-stmt diagnostic.

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

#5725 item 8 (step 1 of 2; step 2 covers the CAPTURE() call sites)

* Drop the redundant semicolon from CAPTURE() call sites; remove -Wno-extra-semi-stmt

doctest_compatibility.h defines CAPTURE(x) as DOCTEST_CAPTURE(x); (with
a trailing semicolon baked into the macro), specifically so call sites
do not need to add one themselves; most of the ~267 call sites already
follow that convention. The remaining 64 call sites across 20 files
wrote "CAPTURE(x);" anyway, turning into a statement plus an empty
statement and triggering -Wextra-semi-stmt. Dropped the redundant
semicolon at each of those sites.

With item 6 having already made vendored Doctest a SYSTEM include, and
this the last known source of -Wextra-semi-stmt findings, removed the
flag from clang_flags.cmake entirely.

Verified with clang++ -Wextra-semi-stmt (plus the file's other CI
ignores) that all 20 touched files, plus a file with no CAPTURE() use
(unit-json_pointer.cpp), compile without any -Wextra-semi-stmt
diagnostic.

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

#5725 item 8 (step 2 of 2)

* Switch ci_static_analysis_clang off the frozen LLVM 22 dev image

ubuntu.yml pinned the clang-tidy/clang-tidy-sanitizer/single-binaries
job to silkeh/clang:dev, a tag last pushed 2026-02-18 that reports
"clang version 22.0.0 (...+20251015...)", a pre-release snapshot from
before the LLVM 22 release; the maintainer now updates dev-unstable,
22, and latest instead. Switched to silkeh/clang:22, matching the
other clang jobs on :latest.

Verified with clang-tidy 22.1.8 (the image's actual version) against
this repository's .clang-tidy and library headers what the release
image newly reports compared to :dev:

- readability-redundant-typename fires at ~250 sites across the
  _cpp20-relevant conversion/to_chars headers; the library targets
  C++11 and keeps the typenames, so the check is disabled in
  .clang-tidy, matching how the file already handles checks that
  don't fit a C++11 codebase.
- misc-anonymous-namespace-in-header fires on the two anonymous
  namespaces in from_json.hpp and to_json.hpp; added the alias to
  their existing NOLINT (cert-dcl59-cpp, fuchsia-header-anon-namespaces,
  google-build-namespaces).
- bugprone-std-namespace-modification fires on every addition to
  namespace std: the std::hash, std::formatter and std::swap
  overloads in json.hpp, and the std::tuple_size/std::tuple_element
  specializations in iteration_proxy.hpp (this last file is not named
  in #5725's item 5, found by actually running clang-tidy 22.1.8
  against the current tree). All six are legal, deliberate additions
  to namespace std (explicit/partial specializations of std types, or
  the pre-C++20 std::swap overload); annotated each with the check
  name next to its existing cert-dcl58-cpp NOLINT.
- modernize-avoid-c-style-cast reported nothing new.

Also added clang++-22/21, clang-tidy-22/21, g++-16 and gcov-16 to the
find_program search lists in ci.cmake so a local "maximal warnings"
configure prefers the current toolchain version over an older one on
PATH.

#5725 item 5

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

* Regenerate cmake/gcc_flags.cmake for GCC 16.2.0

GCC_CXXFLAGS was generated for GCC 15.1.0, but ci_test_gcc and
ci_test_gcc_cxx{11..26} now run in gcc:latest, currently GCC 16.2.0,
so the "maximal warnings" job was missing warnings introduced since
15.1.0 while carrying entries GCC 16 treats as duplicates or no-ops.

Regenerated with https://github.com/nlohmann/gcc_flags (patched
locally to not crash on an option whose "-x c++ <opt> -" probe fails
before it reads stdin, e.g. -Wabi=; the tool otherwise raises
BrokenPipeError instead of recording the option as an error) run
against g++ 16.2.0 in the official gcc:16 Docker image, keeping the
documented -Wno-* exclusions and the same alphabetical placement
scheme as before.

Also added three GCC 16 warnings the generator cannot discover on its
own because it only probes value ranges/lists it finds in the -Q
option name itself, not in the enum choices --help=warnings documents
separately:

- -Wbidi-chars=any, -Wleading-whitespace=spaces: manually verified
  these compile cleanly with g++ 16.2.0.
- -Wstrict-flex-arrays: deliberately NOT added, unlike the other two.
  Without -fstrict-flex-arrays (which the library does not enable, as
  it would change codegen for flexible array members), GCC prints
  "'-Wstrict-flex-arrays' is ignored when '-fstrict-flex-arrays' is
  not present" on every translation unit, and under our -Werror that
  note itself aborts the build. This differs from the harmless
  no-op warnings already kept in the file (-Whsa, -Wsynth,
  -Wunreachable-code, -Wunsafe-loop-optimizations), which emit
  nothing; #5725 item 7 named -Wstrict-flex-arrays as one of the
  flags GCC 16 adds, but did not anticipate this failure mode.

Verified: compiled the library header and a representative set of
test translation units (including ones touched by items 1, 3, 8, 9,
10 of this issue) with the regenerated GCC_CXXFLAGS plus -Werror
under g++ 16.2.0 at -std=c++11 through -std=c++26, with zero warnings;
ran the full local test suite (129/129 passing, unrelated to this
compiler) as a regression check. CI must still confirm the actual
ci_test_gcc / ci_test_standards_gcc targets end to end, since this was
verified with direct g++ invocations rather than through the CMake/
CXXFLAGS environment-variable plumbing in ci.cmake.

#5725 item 7

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

* Avoid std::basic_string<CharType> for non-character output_adapter CharType

output_adapter<CharType, StringType> defaulted StringType to
std::basic_string<CharType>, and (with JSON_NO_IO undefined) always
declared a std::basic_ostream<CharType>&-taking constructor. For
CharType with no non-deprecated std::char_traits specialization (only
std::uint8_t is ever used this way, by the binary writers), simply
naming either type - as an unused default template argument, or as an
unused, never-called constructor's parameter type - instantiates
std::char_traits<CharType> merely to name it, which some standard
libraries mark deprecated: with the library-wide -Wdocumentation
pragma (item 2's other half, left for a later commit) temporarily
removed, an Apple clang 21 / libc++ TU calling json::to_cbor(j, vec)
with std::vector<std::uint8_t>& got one -Wdeprecated-declarations
warning per binary writer at the old output_adapters.hpp:193.

Replaced the eager std::basic_string<CharType> / std::basic_ostream
<CharType> defaults with a bool-tagged partial specialization (not
std::conditional, which requires naming both branches' types up
front regardless of which is selected, reproducing the same warning)
that only ever names std::basic_string<CharType> / std::basic_ostream
<CharType> when CharType is actually one of char, wchar_t, char16_t,
char32_t, or (with __cpp_lib_char8_t) char8_t. For any other
CharType, output_adapter's StringType and ostream-constructor
parameter fall back to two distinct empty placeholder types, kept
distinct so the two constructor overloads do not collide into a
single redeclaration.

Public API / behavior: passing a std::basic_string<std::uint8_t>& or
std::basic_ostream<std::uint8_t>& directly to a binary writer's
output_adapter now fails to compile instead of compiling with a
deprecation warning; this was neither documented nor tested. All
documented uses (std::vector<CharType>, std::basic_ostream<CharType>
and StringType for character CharType) are unaffected.

Verified with Apple clang 21 / libc++, with the two -Wdocumentation*
"ignored" pragma lines in macro_scope.hpp temporarily removed and
-std=c++11/c++20 plus the project's -Weverything flag set: calling
to_cbor/to_msgpack/to_ubjson/to_bjdata/to_bson/to_bon8 on a
std::vector<std::uint8_t> now produces no char_traits<unsigned char>
(or any other) deprecation warning, while the char-based string- and
ostream-adapter paths, and a to_cbor/from_cbor round trip, still
compile and run correctly; also verified with GCC 16.2.0. Ran the
full local test suite, including the binary-format unit tests
(unit-cbor, unit-msgpack, unit-ubjson, unit-bjdata, unit-bson,
unit-bon8, unit-binary_writer_sinks, unit-binary_formats,
unit-custom-binary-type): 129/129 passing.

#5725 item 2 (step a)

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

* Remove the library-wide -Wdocumentation pragma; fix what it hid

macro_scope.hpp / macro_unscope.hpp pushed and popped a Clang
diagnostic region over the entire library that ignored -Wdocumentation
and -Wdocumentation-unknown-command. Removed both pragmas and fixed
every finding a full -Wdocumentation (which implies
-Wdocumentation-unknown-command and -Wdocumentation-deprecated-sync)
build reports, so the library now compiles clean under Clang's
documentation checks without a blanket suppression. Overlaps #5267,
which is still open and edits a nearby doc block (json.hpp's
get()/get_impl() @return, already fixed in the item 2 step (b) commit
of this branch); this commit does not touch that block again.

Unknown Doxygen alias commands (Doxyfile removed in #3071, so these
were never rendered by anything) rewritten as plain prose, keeping the
same information:
- @requirement REQ-JSON-01 / REQ-JSON-02 (iter_impl.hpp,
  json_reverse_iterator.hpp): now "This class satisfies the following
  concept requirements (REQ-JSON-0N):".
- @liveexample{prose,example-id} (three sites in json.hpp): kept the
  prose, dropped the command wrapper and the trailing example-id
  (docs/mkdocs/docs/examples/*.cpp still exist and are used directly
  by the rendered docs, not through this in-header alias) and
  unescaped the "\," commas that were only needed for the old alias's
  comma-separated argument syntax.
- @complexity X (json.hpp x4, json_pointer.hpp x2, serializer.hpp x1):
  now "Complexity: X".

Backslash sequences Clang's comment lexer tried to parse as commands,
escaped to render as literal backslashes:
- lexer.hpp get_codepoint(): two `\u` occurrences.
- binary_reader.hpp get_bson_cstr() / get_bson_cstr_bulk(): two
  `\x00` occurrences.
- serializer.hpp: three `\uXXXX` occurrences (constructor @param,
  append_codepoint_to_string_buffer() @brief, and the ensure_ascii
  member comment).

One finding remained after all of the above: Clang reports
"declaration is marked with '@deprecated' command but does not have a
deprecation attribute" on the deprecated sax_parse(span_input_adapter&&, ...)
overload, even though JSON_HEDLEY_DEPRECATED_FOR does expand to
__attribute__((deprecated(...))) for Clang. Several isolated
reproductions of this exact declaration shape - doc comment,
template<>, two stacked __attribute__ macros, an overload set sharing
the name - did not reproduce the warning, so this looks like a
Clang comment/declaration-association quirk specific to this overload
inside the much larger basic_json class template, not an actual
documentation defect. Rather than keep the pragma library-wide for one
Clang false positive, added a tightly scoped
-Wdocumentation-deprecated-sync push/pop around just that overload.

Verified with Apple clang 21 and the project's actual -Weverything
flag set (cmake/clang_flags.cmake) on the full header at -std=c++11
and -std=c++20: zero -Wdocumentation* diagnostics. Also compiled
clean with GCC 16.2.0 (the pragmas are already __clang__-gated, so
this only confirms no unrelated breakage). Ran make check-amalgamation
and the full local test suite: 129/129 passing.

#5725 item 2 (step c)

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

* Take the JSON value by const reference in the array and tuple from_json paths

Review feedback on #5737 (gregmarr): once the no-op std::forward calls
are gone, the forwarding references have no purpose. from_json_fn
passes the value as const BasicJsonType&, so these functions were only
ever instantiated with a const lvalue anyway.

The std::array, std::pair and std::tuple overloads of from_json and
their helpers now take const BasicJsonType& and pass j on unchanged.
Because the deduced BasicJsonType is now the plain type, tuple_type and
the static_assert name const BasicJsonType& explicitly, so the
reference checks are unchanged: get<std::tuple<const std::string&>>()
still works, and get<std::tuple<std::string&>>() still fails the same
static_assert. from_json_tuple_get_impl keeps its forwarding reference,
since tuple_type calls it through std::declval.

Behavior, the public API and the ABI do not change. unit-conversions,
unit-constructor1, unit-udt, unit-udt_macro, unit-regression1/2/3,
unit-deserialization, unit-noexcept, unit-items, unit-allocator,
unit-custom-object-type, unit-ordered_json2 and
unit-brace-init-copy-semantics pass at C++11, C++17 and C++20 with
unchanged assertion counts. Ran make amalgamate.

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 07:37:47 +02:00
Niels Lohmann
b54ed188e6 Remove test debt: dead guards, discarded results, and unreferenced files (#5732)
* Run the README test case in JSON_FastTests jobs

The "README" test case was marked doctest::skip() when the tests
moved from Catch to doctest in 2019, where it replaced Catch's hidden
tag. It is not slow (17 assertions, about 0.00 s), but cmake/test.cmake
only passes --no-skip when JSON_FastTests is off, so the per-compiler
ci_test_*_cxxNN matrix, macOS, Windows Release/ARM, icpc, icpx and
nvhpc compiled the README examples without running them.

Drop the skip decorator so every job runs the case. Test-only change.

Part of #5713

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

* Remove stale clang ranges guards in unit-iterators2.cpp

The "algorithms" and "views" sections were guarded by clang/libstdc++
checks written for a clang 15 (04/2022) bug. The first guard's
condition contradicts its own comment: it skips clang+libc++ and
keeps clang+libstdc++. Both sections already sit inside
`#if JSON_HAS_RANGES`, which macro_scope.hpp excludes for the
toolchains these guards targeted, so the inner guards never let the
sections run on the platforms they meant to protect and are
redundant on the rest. Verified locally with Apple clang 21/libc++
and clang 16.0.6/libstdc++ 12 (Docker): both pass all 1355
assertions with the guards removed.

Part of #5713

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

* Fix copy-pasted CBOR half-float checks; enable stale encode checks

In the RFC 8949 Appendix A test case, the decode checks for
5.960464477539063e-8 (0xf9 0x00 0x01) and 0.00006103515625
(0xf9 0x04 0x00) were copy-pasted from the neighboring -4.0 example,
so those two half-float byte sequences were never actually decoded
and checked, and -4.0 was checked three times instead. The two
float32 encode checks for 100000.0 and 3.4028234663852886e+38 were
commented out before the writer supported emitting float32 and are
now verified to match byte for byte, so they are enabled. The
remaining commented-out half-precision to_cbor checks are collapsed
into a single explanatory comment, since the writer never emits
half-precision floats.

Part of #5713

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

* Assert on the result of STL container conversions in tests

The "object-like STL containers" and "array-like STL containers"
sections converted json values into std::map, unordered_map,
multimap, unordered_multimap, list, forward_list, array, valarray,
vector, deque, set and unordered_set and discarded the result, so
these ~60 conversions only proved that the code compiles and does
not throw; a conversion that dropped or reordered elements would
still pass. Bind each result and compare it against the expected
container. Also fix a copy-paste slip in the deque section
(`j2.get<std::deque<double>>()` instead of j3, so j3's doubles were
never converted to a deque), and remove the dead
`// CHECK(m5["one"] == "eins")` comments that referred to a variable
that did not exist by asserting the equivalent through the bound
result.

Part of #5713

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

* Deduplicate SaxCountdown and other test helpers across formats

SaxCountdown was copied byte-for-byte into six binary-format test
files (unit-cbor.cpp, unit-msgpack.cpp, unit-ubjson.cpp,
unit-bjdata.cpp, unit-bon8.cpp, unit-bson.cpp), about 370 redundant
lines. Move it into tests/src/sax_countdown.hpp (namespace utils,
alongside test_utils.hpp and round_trip_corpus.hpp) and include it
from all six.

trait_test_arg and the "value_in_range_of trait"
TEST_CASE_TEMPLATE_DEFINE were duplicated between unit-32bit.cpp and
unit-bjdata.cpp; the trait is a detail/meta trait, not specific to
either file. Move it into tests/src/value_in_range_of_test.hpp;
unit-32bit.cpp keeps its own include, since JSON_32bitTest=ONLY
builds only that file. Each file keeps its own
TEST_CASE_TEMPLATE_INVOKE list.

sax_no_exception and the "issue #2824" section were duplicated in
unit-regression2.cpp and unit-disabled_exceptions.cpp. Drop the copy
from unit-regression2.cpp; unit-disabled_exceptions.cpp already
covers the no-exceptions case that #2824 was about, and
ci_test_noexceptions reruns it.

No behavior change. Verified by building and running unit-cbor,
unit-msgpack, unit-ubjson, unit-bjdata, unit-bon8, unit-bson,
unit-32bit, unit-regression2 and unit-disabled_exceptions against
include/ (clang++ -std=c++11, ASan/UBSan where applicable); assertion
counts are unchanged from before the refactor.

Part of #5714

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

* Remove the unreferenced vendored libFuzzer

tests/thirdparty/Fuzzer (155 files, ~776 KB of vendored Apache-2.0
LLVM code from the 2016 OSS-Fuzz import) is not referenced by any
CMakeLists, Makefile or workflow: the fuzz drivers link against
-fsanitize=fuzzer or the repo's own
tests/src/fuzzer-driver_afl.cpp. Its vendored README only points at
llvm.org's own libFuzzer docs. Being dead code, it also adds noise
to the flawfinder code-scanning workflow, which scans the whole
tree. Remove the directory and its .reuse/dep5 entry.

Part of #5714

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

* Remove unreferenced 2016 benchmark and fuzz reports

tests/reports (1.6 MB) holds AFL status pages and plots from
2016-08-29 and 2016-10-02, and a nativejson-benchmark snapshot from
2016 with links to rawgit.com, which shut down in 2019. Nothing
references this directory: no doc, README section, script or
workflow points at it, and it describes a ten-years-old, pre-2.0
snapshot of the library.

Part of #5714

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

* Run the CBOR, MessagePack, BSON and BON8 round-trip invariants in CI

tests/src/round_trip_corpus.hpp exists so that the byte-stability
invariant the fuzzer drivers check also runs on a fixed corpus in CI,
instead of only at OSS-Fuzz. So far only the UBJSON and BJData drivers
had a matching unit test; the CBOR, MessagePack, BSON and BON8 drivers
assert the same invariant (assert(to_X(j2) == vec)) but nothing ran it
outside OSS-Fuzz.

Add "<FORMAT> round-trip invariants" test cases to unit-cbor.cpp,
unit-msgpack.cpp, unit-bson.cpp and unit-bon8.cpp, modeled on the
UBJSON case: seed j1 from the corpus (skipping values that do not
survive the format's own round trip, as the fuzzer drivers only ever
see values from_X() actually produced), then require from_X(to_X(j1))
not to throw and check to_X(j2) == to_X(j1). BSON only serializes
objects, so non-object corpus values are skipped. Update the comments
in round_trip_corpus.hpp and tests/fuzzing.md to name all six formats.

The stream-versus-contiguous check in the BON8 driver is left out, as
#5601 reworks it.

A local probe confirms no violations on the current corpus (CBOR 3849
checked, MessagePack 3909, BSON 2958, BON8 3841 - matching the counts
already recorded for this probe in the issue).

Closes #5714 item 1.

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

* Fix fuzzer driver step lists to match the checks the code performs

The header comment of six of the seven binary-format fuzzer drivers
listed an invariant the code does not check: CBOR, MessagePack, BSON
and BON8 said "assert(j1 == j2)", but the code checks byte stability,
assert(to_X(j2) == vec). UBJSON and BJData still described the old
"assert(j1 == j2/j3/j4)" byte-exact check from before PR #5494 replaced
it with a use_size/use_type-aware round trip (UBJSON) and a
value-stability check (BJData); BJData's added paragraph already
explained the new check, but the step list above it did not.

Also remove a dead branch in fuzzer-parse_bson.cpp: from_bson() is
called with allow_exceptions = true, so it throws instead of returning
a discarded value, and the "if (j1.is_discarded()) return 0;" guard
could never trigger. Drop the unused <iostream> include from all seven
drivers and <sstream> from all but fuzzer-parse_bon8.cpp, which is the
only one that uses std::istringstream.

Overlaps #5601, which edits all seven drivers in the same hunks.

Closes #5714 item 4.

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

* Silence the CMP0169 deprecation in cmake_fetch_content, fix stale guards

tests/cmake_fetch_content/project calls the single-argument
FetchContent_Populate(json) after FetchContent_Declare(), which CMake
3.30 deprecated as CMP0169. Since the project declares
cmake_minimum_required(VERSION 3.11...3.14), the policy stays unset,
so every configure with a current CMake prints the deprecation
warning. The test is kept on purpose: it is the only coverage of the
FetchContent_Populate + add_subdirectory pattern for CMake 3.11-3.13
users, which the docs still describe as supported. Explicitly set
CMP0169 to OLD, with a comment explaining why.

Also fix two stale version guards:
- tests/cmake_fetch_content/CMakeLists.txt guarded the test with
  VERSION_GREATER "3.11.0", which is dead now that tests/CMakeLists.txt
  requires CMake 3.13.
- tests/cmake_fetch_content2/CMakeLists.txt guarded with
  VERSION_GREATER "3.14.0", which skips exactly 3.14.0, the first
  version with FetchContent_MakeAvailable. Change it to
  VERSION_GREATER_EQUAL "3.14".

Verified locally: `ctest -R cmake_fetch_content` passes with CMake
4.1, and the CMP0169 deprecation warning that appeared before this
change is gone.

Closes #5714 item 5.

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

* Make the CMake integration-test wrappers consistent

The six tests/cmake_* integration-test wrappers had drifted:

- Only cmake_import and cmake_import_minver forwarded
  -A "${CMAKE_GENERATOR_PLATFORM}" to the inner configure, and none
  forwarded -T "${CMAKE_GENERATOR_TOOLSET}". The Windows workflow
  configures the outer build with -A Win32 -T ClangCL, so without
  forwarding, the inner projects of cmake_add_subdirectory,
  cmake_fetch_content, cmake_fetch_content2 and
  cmake_target_include_directories built with the generator defaults
  instead of matching the outer build's platform and toolset. Forward
  both consistently from all six wrappers.
- cmake_fetch_content and cmake_fetch_content2 passed
  -Dnlohmann_json_source to their inner projects, which never read it
  (CMake warns "manually-specified variables were not used"); the
  inner projects fetch their own copy of the library instead. Drop it.
- tests/CMakeLists.txt set JSON_FORCED_GLOBAL_COMPILE_OPTIONS from the
  matching environment variable but never read the cache variable
  again; the lines right below it read $ENV{JSON_FORCED_GLOBAL_COMPILE_OPTIONS}
  directly, like the LINK_OPTIONS counterpart already does. Remove the
  dead set().

This changes which platform and toolset the Win32 and ClangCL CI jobs
build the four newly-forwarding wrappers' inner projects with, which
may surface new failures there; CI has to confirm those jobs.

Verified locally with Ninja (empty -A ""/-T "" is accepted): all 12
cmake_* tests still pass, and the inner fetch_content configures no
longer warn about the unused variable.

Closes #5714 item 6.

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

* Turn the #972 fifo_map regression test into a real test

The #972 regression test in unit-regression1.cpp only built a
my_json array from a string literal (the original crash) and had no
CHECK, so the fifo_map object type it exists to demonstrate was never
exercised. Meanwhile the docs recommend fifo_map for keeping object
keys in insertion order (object_order.md, template_parameters.md),
and nothing tested that recommendation.

Extend the section: after the original array assignment, parse an
object with my_json::parse() (not via the "..."_json UDL, which
returns a plain nlohmann::json and would exercise the cross-basic_json
conversion constructor instead of the parser's own key insertion -
and, as tried locally, does not keep fifo order for this stateful
comparator) and check that dump() keeps insertion order, and that it
survives erase() and inserting a new key.

Also narrow thirdparty/fifo_map off the include path of every other
test-* target: it was a PUBLIC include directory of test_main, even
though unit-regression1.cpp is its only user. Add a small
fifo_map_include INTERFACE library with that include directory and
attach it to test-regression1 only via json_test_set_test_options().

Verified locally (test-regression1_cpp11, default build and
-fsanitize=address,undefined): the new checks pass; `git grep fifo_map
tests` still only finds unit-regression1.cpp and the vendored header.

Closes #5714 item 7.

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

* Document the vendored doctest.h patch; fix stale doctest_compatibility.h comments

tests/thirdparty/doctest/doctest.h is doctest 2.4.12, imported in
#4771. Two weeks later, #4801 hand-edited translateActiveException()
to declare "String res;" inside the translator loop instead of before
it, so a translator that does not match does not leave a previous
translator's result in "res" for the next iteration to see. Nothing
recorded this, so re-vendoring doctest.h from upstream would silently
drop the fix. Add a comment at the patched site naming the version,
the PR and the reason, so a future re-vendor knows to re-apply it.

Also fix two stale comments in doctest_compatibility.h:
- The DOCTEST_THREAD_LOCAL comment referenced Xcode 6/7, which is no
  longer supported; reword it to explain why the define must stay
  regardless (it keeps doctest's own thread_local usage out of the way
  of the same Clang/MinGW crash that JSON_NO_THREAD_LOCAL works around
  in the library, see ci_test_no_thread_local).
- The <iosfwd> include's comment justified it with tests that define
  "private" as "public"; no test under tests/src does that any more
  (removed by #2352). Reword the comment instead of dropping the
  include, since confirming it is safe to drop needs the full CI
  matrix including MSVC 2015+.

Verified locally that tests/src/unit-readme.cpp still builds and
passes 17/17 with these headers.

Closes #5714 item 9.

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

* Stop compiling unit-wstring.cpp out entirely on classic ICC

tests/src/unit-wstring.cpp wrapped the whole file in
#ifndef __INTEL_COMPILER, with the comment "ICPC errors out on
multibyte character sequences in source files". The ci_icpc job
(intel/oneapi-hpckit:2023.2.1) still exists, so that job ran none of
the wstring/u16string/u32string input adapter tests, including the
malformed-input checks #5704 (open) extends.

Only 9 lines contained non-ASCII bytes: the three *_is_utf16()/
*_is_utf32() probe functions, and three std::wstring/u16string/
u32string literals plus their narrow-string dump() expectations.
Rewrite all of them with \u/\U escapes in the wide/u16/u32 literals
and \x escapes (split into separate string-literal tokens so a
following byte is never read as part of the same hex escape, e.g.
"\xE1\x83\x85" "a") in the narrow ones. Remove the
#ifndef __INTEL_COMPILER/#endif guard along with it.

The *_is_utf16()/*_is_utf32() probes compared a raw multibyte literal
against an escape-based one to detect a compiler that misreads the
source file's encoding; with no raw literals left to misread, the
comparison is now tautological, so drop the probes and the "if"
guards around each SECTION's body instead of leaving them in as dead
checks.

The same non-ASCII-in-source-and-in-a-narrow-comparison pattern
existed once more in unit-deserialization.cpp's "Using _json with
char8_t literals #4945" test: a raw emoji character in a u8R"(...)"
literal, guarded by a check_utf8() that returned false for ICC (same
reason) and for Windows without the active UTF-8 code page. Rewrite
the literal with a \U escape and compare it against a \x-escaped
expectation instead of a second raw literal, and drop check_utf8()
and the now-unused <windows.h> include along with the guard.

Verified locally (clang, -std=c++11 and -std=c++20,
-fsanitize=address,undefined, and a plain build): test-wstring keeps
18/18 assertions and unit-deserialization keeps 466/466 (c++11) and
477/477 (c++20) assertions, matching this branch before the change
exactly - no coverage was gained or lost, only the source-encoding
dependency was removed. ci_icpc has to confirm classic ICC actually
builds and passes test-wstring now; if it does not, that is a real
finding, not a reason to restore the guard.

Overlaps #5704 (open), which edits unit-wstring.cpp inside the
previously-guarded region (an include near the top, checks in the
invalid-string sections, and a new section at the end).

Closes #5713 item 5.

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 07:33:07 +02:00
Niels Lohmann
cff0a61369 Share DOM SAX position handling; fix stale parser and lexer comments (#5731)
* Share the diagnostic-position setter of the DOM SAX parsers

json_sax_dom_parser and json_sax_dom_callback_parser each had a private
copy of handle_diagnostic_positions_for_json_value(), identical except
for comments. Move the body into one static member function,
detail::diagnostic_positions::set_from_lexer(value, lexer), which both
classes call with their lexer pointer. basic_json befriends the new
struct (only when JSON_DIAGNOSTIC_POSITIONS is enabled), as the position
members are private.

The discarded case is reached through the callback parser, so the
LCOV_EXCL markers that only the dom parser's copy had are gone. The
NOLINT on the unreachable default case loses the stray
"-warnings-as-errors", which is not a check name.

The start-position setup in start_object()/start_array() is left alone,
as #5706 is editing the callback parser's versions.

Behavior, the public API and the ABI are unchanged.

Part of #5712

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

* Correct the parser comments on recursion and skip_to_state_evaluation

The class documentation called the parser a recursive descent parser,
but sax_parse_internal() is a loop that keeps the open containers on an
explicit stack. The comment at the end of an array and of an object
said the flag is set to false while the code below it sets it to true.
Describe what the code does instead.

Comments only; behavior, the public API and the ABI are unchanged.

Part of #5712

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

* Update the discard_number_values comments to the current number path

The comments explaining the accept() shortcut in convert_number() and
the member documentation still argued in terms of strtoull()/strtoll()
and errno, which #5283 replaced with convert_integer(), and pointed at
scan_number() instead of convert_number(). They also did not say that
scan_number_bulk_contiguous() converts integers itself, so the shortcut
is only reached for input without bulk access, with
JSON_DIAGNOSTIC_POSITIONS, or when the bulk scanner falls back.

Rewrite both comments to describe the digit-count check in front of
convert_integer(), keeping the 18-digit bound and the json_sax_acceptor
argument. The stale <cstdlib> comment is left for after #5616, which
edits that include block.

Comments only; behavior, the public API and the ABI are unchanged.

Part of #5712

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

* List the UTF-8 validators instead of calling the DFA the only one

The documentation of decode() called the Hoehrmann DFA the single
source of truth for UTF-8 validation. It is used only by the serializer
and by is_valid_utf8() (CBOR/MessagePack/BSON/UBJSON/BJData text
strings). The lexer's scan_string() switch, validate_one_utf8() /
valid_utf8_prefix() (bulk string scan, BON8 bulk path and BON8 writer)
and the BON8 byte path in get_bon8_string() check the RFC 3629 ranges
on their own.

Replace the sentence with a list of the four validators, what each is
used for, and a note that they must accept the same sequences. Sharing
code between them was considered and dropped: it would save a few lines
in a validator that is entangled with BON8 pushback, and #5677 is
editing the BON8 byte path.

Comments only; behavior, the public API and the ABI are unchanged.

Part of #5712

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

* Fix stale doc comments and include lists in the input headers

input_adapters.hpp included <memory> and <numeric> for the removed
shared_ptr-based adapter design but used neither; it called
(std::min) without including <algorithm>. json_sax.hpp used
std::numeric_limits without including <limits>. Also corrected
comments that no longer matched the code: input_stream_adapter does
not skip the input's BOM (the lexer's skip_bom() does), the
span_input_adapter comment named the no-longer-existing
input_buffer_adapter type, lexer::get_string() does not reset the
token, binary_reader's get_number() doc opened with /* instead of
/*! (so Doxygen skipped it) and omitted BON8 from its endianness
note, and the UBJSON-binary-types note did not mention that BJData
'B' arrays are read as binary.

Left out: the lgtm suppression on lexer.hpp's scan_number() (in
#5616's hunk) and the "-1 if unknown" wording in json_sax.hpp's
start_object/start_array docs (in draft #5267's hunk), per the
verdict's conflict list.

Part of #5712

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

* Deduplicate the strict-EOF/release_lookahead/error block in parser::parse()

json_sax_dom_callback_parser and json_sax_dom_parser branches of
parser::parse() ran the same ~25 lines after sax_parse_internal():
the strict-mode EOF check (raising parse_error.101 through the SAX
parser), release_lookahead() in non-strict mode, and mapping an
errored SAX parser to a discarded result. The two copies had already
drifted apart in formatting and in the second copy's "see above"
comment.

Add a private parse_dom(DomSax&, strict) member that runs this shared
sequence once and returns whether the SAX parser did not error; both
branches of parse() now only construct their DOM SAX parser, call
parse_dom(), and (for the callback parser) map a discarded top-level
value to null. sax_parse() is left untouched, since it only runs the
EOF check and release_lookahead() when sax_parse_internal() succeeded,
unlike parse(), which runs them unconditionally.

Behavior-preserving: same operations in the same order for both SAX
parser kinds. Verified with unit-class_parser (strict/non-strict,
callback and non-callback), unit-deserialization and
unit-disabled_exceptions (JSON_NOEXCEPTION), plus a clean
make amalgamate / make check-amalgamation diff.

Overlaps #5601, which touches the same lines.

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

#5712 item 2

* Share the code point to UTF-8 encoding between the wide-string helpers and the lexer

The 1/2/3/4-byte UTF-8 encoding ladder was written out by hand three
times: in wide_string_input_helper<..., 4>::fill_buffer() for a UTF-32
code point, in the UTF-16 helper for both a BMP code unit and a valid
surrogate pair, and in the lexer's \uXXXX/\uXXXX\uYYYY handling. The
copies had drifted: the UTF-32 helper masked the leading bits of each
byte (& 0x1Fu, & 0x0Fu, & 0x07u) where the others relied on the shift
alone, even though both give the same result for a code point that is
already known to be in range.

Add detail::encode_utf8(cp, out) in string_utils.hpp, a single encoder
that invokes a callable once per output byte, most significant byte
first. Use it in the three valid-code-point branches (UTF-32 code
points up to U+10FFFF, UTF-16 code units outside the surrogate range,
and valid UTF-16 surrogate pairs) and in the lexer's \u handling, where
out forwards to add(). The UTF-16 helper's deliberate pass-through of
malformed surrogate units and the UTF-32 helper's 0xFF sentinel for
code points above U+10FFFF are untouched, since neither reaches the new
helper.

Behavior-preserving: same bytes in the same order for every valid code
point, verified with unit-class_lexer, unit-class_parser,
unit-deserialization, unit-wstring and the non-test-data parts of
unit-unicode1..5 (ASan/UBSan, C++11/17/20), and an escape-heavy parse
microbenchmark that shows no change (about 73 ms either way, median of
3, 1M escape sequences). single_include/ regenerated with make
amalgamate; make check-amalgamation leaves a clean tree.

Overlaps #5704, which rewrites the wide_string_input_helper
specializations touched here.

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

#5712 item 6

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 07:32:32 +02:00
Niels Lohmann
3926fcaac3 Deduplicate serializer dump code; fix stale includes, docs, and lint (#5729)
* Share scalar serialization between dump_internal and dump_value

dump_value()'s cases for string, binary, boolean, number_integer,
number_unsigned, number_float, discarded and null were a byte-for-byte
copy of dump_internal()'s (added together in #5285 for the iterative
fallback path). Any future change to scalar output had to be made in
both places, or the recursive and depth-limited paths would silently
start producing different bytes.

Extract the shared cases into a private dump_scalar() and have both
dump_internal() and dump_value() call it. Output is unchanged: dump(),
dump(4), dump(-1,' ',true) and the replace/ignore error_handler_t
variants are byte-identical over the json_test_data corpus before and
after, and dump() throughput on a scalar-heavy document is unaffected.

Part of #5709

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

* Drop serializer.hpp's dependency on binary_writer.hpp

The only use of binary_writer in serializer.hpp was
binary_writer<BasicJsonType, char>::to_char_type() to write the
U+FFFD replacement character's three bytes. With CharType=char this
is an identity conversion, so the include of binary_writer.hpp (and
transitively binary_reader.hpp) pulled in a large, unrelated header
for a no-op call.

Write the three bytes directly instead. serializer.hpp compiles
standalone with -Wall -Wextra -Werror, with and without
-funsigned-char, and unit-serialization's error_handler_t::replace
cases (with and without ensure_ascii) still pass. Moving
binary_writer's to_char_type/to_msgpack_length to its private section
is left as an optional follow-up.

Part of #5709

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

* Fix stale #include lines in the output headers

output_adapters.hpp included <algorithm> and <iterator> for std::copy
and std::back_inserter, which have not been used there since #3569
(2022). serializer.hpp included <algorithm> for std::reverse (also
unused), <cmath> for labs/isnan/signbit (only std::isfinite is used)
and <utility> for std::move (nothing from <utility> is used there),
while using std::next without including <iterator> at all, relying on
getting it transitively through output_adapters.hpp's own stale
<iterator>.

Drop the unused includes, add <iterator> for std::next, and correct
the remaining include comments. Both headers still compile standalone
with -Wall -Wextra -Werror.

Part of #5709

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

* Remove JSON_HEDLEY_NON_NULL(2) from write_characters() overrides

output_vector_adapter, output_stream_adapter and output_string_adapter
declared their write_characters(const CharType*, std::size_t) override
JSON_HEDLEY_NON_NULL(2), but binary_writer legitimately calls it with
a null pointer and length 0 for an empty string or binary value; the
type-erased call path only stayed silent under UBSan because the
static callee at those call sites is the unattributed virtual base.
A nonnull attribute on a definition lets GCC and Clang assume the
parameter is non-null inside the function body even when the call is
virtual, so this was latent undefined behavior, not just style.

Drop the attribute from the three overrides and document the
(nullptr, 0) contract on output_adapter_protocol::write_characters.
unit-cbor, unit-msgpack, unit-bson and unit-bon8 (which all exercise
empty binary/string payloads through the stream and vector/string
adapters) pass under -fsanitize=address,undefined,nonnull-attribute.

Part of #5709

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

* Update stale serializer doc comments to match the current implementation

dump_internal()'s doc block still described the pre-#5285/#5449
implementation: an escape_string() function that does not exist
(the function is dump_escaped), integer conversion "implicitly via
operator<<" (dump_integer actually uses a digit-pair lookup table),
and floating-point conversion via "%g" (IEEE-754 types go through
to_chars, others through snprintf). dump_value()'s comment said
elements are pushed for dump_internal to walk, but it is
dump_iteratively() that walks the stack. dump_escaped(), dump_integer()
and dump_float() each said they write "to output stream @a o", which
has not been true since the writer moved to write_buffer.

Doc-only change; no behavior, API or ABI impact.

Part of #5709

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

* Merge duplicate byte-to-hex helper and drop stale '| 0' promotions

serializer::hex_bytes() and binary_writer::hex_byte() had identical
bodies. Keep one, detail::hex_byte() in string_utils.hpp, and use it
from both. Also drop the `| 0` at the two serializer call sites
(hex_bytes(byte | 0) and hex_bytes(s.back() | 0)): #3088 (7440786b8)
added it so that `ss << std::hex << (byte | 0)` printed a number
rather than a char with the old stringstream writer; the int result
just narrows back to uint8_t now, so it was a no-op.

Behavior is unchanged: unit-serialization, unit-bon8 (whose
type_error.316 messages exercise this code) and unit-diagnostics
pass, and both headers still compile standalone with -Werror.

Part of #5709

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

* Trim two stale lint suppressions in serializer.hpp

dump_integer()'s `auto buffer_ptr = number_buffer.begin();` carried
NOLINT entries for cppcoreguidelines-pro-type-vararg and hicpp-vararg,
left over from the snprintf-based implementation (#3088); there is no
variadic call on that line, so keep only the qualified-auto
suppressions it actually needs. remove_sign()'s assert checked
`x < 0 && x < (std::numeric_limits<number_integer_t>::max)()) `with a
NOLINT(misc-redundant-expression) to hide it; the second conjunct is
always true once x < 0, and has been since 6ce2f35ba (2019), so
reduce the assert to `x < 0` and drop the suppression instead of
masking it.

Both are documentation-only changes to assertions/suppressions, not
behavior. The to_chars.hpp `#if 0` branch this item also flagged is
left alone, next to draft PR #5634's pending hunk.

Part of #5709

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

* Move the Hoehrmann SPDX copyright line to string_utils.hpp

serializer.hpp carried the SPDX-FileCopyrightText line for Björn
Hoehrmann's UTF-8 decoder, but the decoder (decode() and the utf8d
table) has lived in string_utils.hpp since #5185 (d19f7f5dc);
serializer.hpp now only calls decode(). Move the copyright line to
where the code it covers actually is.

Part of #5709

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

* Stop calling std::localeconv() on every dump()

The serializer constructor snapshotted std::localeconv() into a
locale_chars member on every dump(), even though the only reader is
dump_float(number_float_t, std::false_type)'s snprintf path, taken
only for a number_float_t that is neither IEEE single nor double.
localeconv() is not required to be thread-safe with setlocale(), so
every dump() paid for and raced on a lookup that almost never mattered.

Remove locale_chars and the locale member. Right before the
thousands-separator/decimal-point fixups in the snprintf path, read
std::localeconv() into local thousands_sep/decimal_point variables
(null-checked, first byte only, as before) - the same way
lexer::get_decimal_point() already does since #5597. Output is
unchanged unless the locale changes during a single dump(); in that
case the fixups now match what snprintf just produced, instead of a
value snapshotted before the call.

Overlaps draft PR #5608, which touches the same constructor and
dump_float() lines to move this code into a new
dump_float_snprintf(); this lands the lookup change now as #5709 asks,
and #5608 can do the lookup inside dump_float_snprintf() when it
rebases.

Verification: the full json_test_data corpus (742 files, dump(),
dump(4) and dump(-1,' ',true)) is byte-identical to before the change
under the C locale. Added a test pinning the new per-conversion
lookup: it switches LC_NUMERIC mid-dump() (via a streambuf that
switches on its first write, after the serializer's write buffer has
been flushed once but before a later float is converted) and checks
the decimal point is still normalized using the locale active at
conversion time. On a platform where long double is IEEE-754 double
(e.g. 64-bit Arm), dump_float() takes the locale-independent
to_chars() path and the test is a no-op there; it is meaningful on a
platform where long double is extended precision (most x86 targets).

Part of #5709 item 3

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 07:31:42 +02:00
Niels Lohmann
18dd5663b0 Diff deeply nested values without recursing per nesting level (#5548)
* Diff deeply nested values without recursing per nesting level

diff() descended into both values once per nesting level, and compared
them with operator== on every level on the way, which recurses as well.
Values nested deeply enough - 25,000 levels on an 8 MiB stack - exhausted
the call stack and terminated the process, although parse() accepts
them without complaint. On such a chain the per-level comparisons and
path strings also made diff() quadratic in time and memory.

Both the recursion and operator== only descend as far as the source is
nested. So diff() first checks, recursing at most diff_depth_limit()
(128) levels, whether the source is nested more deeply than that. If not
- all but a vanishing minority of values - the recursive algorithm
diffs it exactly as before, now as diff_recursively(). Otherwise
diff_iteratively() walks the two values on an explicit stack, emitting
the same operations in the same order. It does not compare arrays and
objects with operator== up front (equal ones yield no operations
anyway), keeps the path in one buffer instead of a new string per
level, and hands every subtree that is not nested too deeply back to
diff_recursively(), so equal parts are still skipped quickly.

The check costs one pass over the source. On a 3,000-object document
that is about 30% of diffing two equal values (which is just an
operator== call), about 10% of diffing values that differ in a few
places, and noise when arrays change length. Once operator== no longer
recurses (#5390), the check can go.

Tests check that the patch reproduces the target at every depth up to
300, for json and ordered_json, including reordered members. They also
check the exact operation for a difference deep inside, and diff values
nested 100,000 levels deep.

Fixes #5393 for diff().

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

* Make diff_frame a member struct that declares its special members

GCC's -Weffc++ (an error in CI) asks a class with pointer members, a
user constructor and a non-trivial destructor to declare its copy
constructor and copy assignment; diff_frame's vector and basic_json
members make its destructor non-trivial. Declare all five as defaulted,
which also satisfies clang-tidy's special-member-functions check. Leave
their exception specifications implicit: GCC 4.8 rejects an explicit
one that differs from the implicit one, as it does for flatten_task in
#5517.

The converting constructor cannot throw, and is now declared noexcept
for GCC's -Wnoexcept, which flags the emplace_back() under C++26
otherwise. The struct also moves from diff_iteratively() into the class,
like dump_frame in the serializer.

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

* Use the shared recursion limit in diff()

diff_depth_limit() is gone in favor of detail::recursion_depth_limit().

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

* Diff fewer nesting depths so the test does not time out under Valgrind

Checking every depth up to 300 made test-json_patch exceed the 1500 s ctest
timeout in ci_test_valgrind. Check the depths up to 16, those around the
recursion limit of 128, and 300 instead.

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

* Mark the diff frame's value-initialized members for clang-tidy

The braces are kept for GCC's -Weffc++, as in json_sax.hpp.

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

* Bound diff()'s descent with a depth count instead of scanning the source

Now that operator== no longer recurses (#5390), diff() can keep its per-level
equality shortcut all the way down. It diffs recursively for the first
detail::recursion_depth_limit() levels, as merge_patch() does, and hands
anything deeper to diff_iteratively(). The nesting_exceeds() scan, which
cost about 30% on equal documents, is gone, and diff() is on par with
develop again.

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

* Note that the diff frame reference is invalidated by pop_back() too

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

* Keep diff()'s recursive levels small and its result elided

diff_recursively built every patch operation in place from initializer
lists. Unoptimized builds give each of those temporaries its own stack
slot, so every level of the bounded descent cost kilobytes of stack
(about 6 KB with clang -O0), and the 128 recursive levels overflowed the
1 MB stack of MSVC Debug in the "deeply nested values" test. The
operations and the key comparison of two objects are now built by
separate functions, which diff_iteratively shares, and both diff
functions append to one result instead of returning a patch per level
that the caller copies. With clang -O0, diffing values nested 300 levels
deep now peaks at about 190 KB of stack instead of 880 KB.

Since diff() now owns the only returned value, clang's -Wnrvo no longer
reports the returns of diff_recursively, which alternated between the
local patch and diff_iteratively's result.

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

* Copy the diff frame's members instead of holding a reference to it

The loop in diff_iteratively held a reference to the top frame, which
enter() invalidates when it pushes and the end of the loop invalidates
when it pops. Nothing used it afterwards, but a later change could. As in
the other iterative walks, the members the loop reads are now copied out
as constants and the ones it advances are changed through stack.back().
The frame as a whole is not copied: it holds the common keys and the
"add" operations of an object.

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 07:29:32 +02:00
Niels Lohmann
a32f61eb98 Fix update() and merge_patch() when the argument is *this or one of its members (#5678) 2026-09-30 23:04:57 +02:00
Niels Lohmann
1d675cdb46 Fix CI jobs that check less than they claim; move arm64 to GitHub (#5733)
* Fix the ci_cmake_flags wiring so every option is checked

The CMake 3.31.6 flag list referred to itself before it was defined,
so only JSON_BuildTests was checked with that version. The targets for
the CMake running the build ("_2") were created but never added to
ci_cmake_flags, and the three versions shared one build directory.
JSON_StrictNulHandling was not in the list at all.

Use the 3.5.0 list for 3.31.6, add JSON_StrictNulHandling, and create
one ci_cmake_flag_<flag> target per option for the running CMake with
its own build directory. Also use the function parameter in the
COMMENT, refresh the stale version comment, and let ci_clean remove
the downloaded cmake-<version> directories instead of the long-gone
cmake-3.5.0-Darwin64.

Part of #5715

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

* Fix ci_test_clang_libcxx_cxx* jobs silently building without warnings

CMake only seeds CMAKE_CXX_FLAGS from the CXXFLAGS environment variable
when the cache entry is unset, so the explicit -DCMAKE_CXX_FLAGS="-stdlib=libc++"
argument made it ignore CXXFLAGS="${CLANG_CXXFLAGS}" entirely. The six
ci_test_standards_clang (..., libcxx) jobs therefore compiled without
-Weverything/-Werror while their libstdc++ siblings did use them.

Pass -stdlib=libc++ through the same CXXFLAGS value instead of a separate
-D argument, and give the target its own build directory
(build_clang_libcxx_cxx${CXX_STANDARD}) so it no longer shares a CMake
cache with the libstdc++ variant. Suppress the resulting
-Wthread-safety-negative finding from libc++'s std::mutex annotations,
which fires on doctest's reporters in this translation unit only.

Part of #5715

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

* Remove the no-op AppVeyor with_win_header job

The with_win_header matrix entry patched Windows.h into
single_include/nlohmann/json.hpp before building, but JSON_MultipleHeaders
has defaulted to ON since #3532 (2022-06), so CMakeLists.txt points the
tests at include/ and the patched single header is never compiled. The
job has been a no-op VS2015 build since then.

Windows.h coverage already exists through tests/src/unit-windows_h.cpp
(#3631), which runs in every MSVC job. Delete the dead matrix entry and
its before_build steps, and cite unit-windows_h.cpp from the QA page.

Part of #5715

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

* Remove unused ci_oclint and ci_pvs_studio targets

No workflow invokes ci_oclint, ci_pvs_studio, or their tool discovery.
ci_oclint also had a side effect on every JSON_CI configure: it copied
the single header into src_single/all.cpp and added an add_executable()
for it without EXCLUDE_FROM_ALL, so a plain build compiled a 1.2 MB
translation unit that only that unused target consumed. ci_pvs_studio
duplicates the Makefile's pvs_studio target, which is kept.

Also drop the duplicate --check-level=exhaustive flag passed twice to
the same ci_cppcheck invocation.

Part of #5715

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

* Stop Dependabot from proposing astyle bumps

astyle is deliberately pinned at 3.4.13 because newer versions reformat
unrelated lines and this version defines the formatting that
check_amalgamation.yml enforces. Without an ignore rule, Dependabot
keeps opening PRs for every new astyle release (most recently #4580,
#4942, #5445, #5448), each of which fails the amalgamation check and
gets closed unmerged.

Part of #5715

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

* Move Linux arm64 CI from dead Cirrus CI to ubuntu-24.04-arm

Cirrus CI stopped reporting check runs on develop sometime after
d10879bca (2026-05-26); every commit since has only github-actions
check runs, so .cirrus.yml silently lost its only consumer while
README.md, FILES.md and the QA page kept advertising the coverage.

Add a ci_test_arm64 job to ubuntu.yml using the same pinned
actions/checkout and lukka/get-cmake actions as the other jobs, on the
native ubuntu-24.04-arm runner, with a step that confirms uname -m
reports aarch64. Delete .cirrus.yml and its README badge and FILES.md
section, and update the QA page's arm64 row.

Part of #5715

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

* Make scan-build fail on findings and drop irrelevant checkers (#5715 item 4a)

ci_clang_analyze ran scan-build without --status-bugs, so the job
passed whenever the ninja build succeeded, no matter what the
analyzer found ("No bugs found" in a green run gave no signal either
way). It is also missing --use-analyzer=${CLANG_TOOL}, so scan-build
picks whichever clang happens to be first on PATH inside the
silkeh/clang:dev container instead of the one this file already
selected and versioned.

Add --status-bugs and --use-analyzer=${CLANG_TOOL} to the scan-build
invocation. While here, drop the osx.*, webkit.*, fuchsia.*, and
optin.mpi.* checkers from CLANG_ANALYZER_CHECKS: none of them apply
to this portable C++ library, and leaving them enabled only adds
noise once the job can actually fail on a finding.

The job is currently clean (0 bugs), so this alone does not surface
any new finding; it only makes the existing "no bugs found" result
authoritative. This is 4a of 3 independent steps in #5715 item 4;
4b (Infer) and 4c (IWYU) still need their existing findings triaged
before --fail-on-issue/-Xiwyu --error can be added, and are handled
in separate commits.

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

* Deduplicate the amalgamation/format check's file set and add BUILD.bazel (#5715 item 5)

The amalgamation/format check existed three times with three different
file sets: the Makefile's pretty/check-amalgamation, the pull_request-only
check_amalgamation.yml workflow, and the ci_test_amalgamation CMake target
that also runs on direct pushes to develop/master/release/*. The CMake
target's glob was a strict subset of the workflow's (missing the
docs/mkdocs/docs/examples/*.hpp headers, tests/abi/, tests/cmake_*/project/,
tests/cuda_example/, tests/fmt_formatter/, and tests/module_cpp20/), and it
never checked BUILD.bazel at all, so a misformatted file in any of those
paths, or a stale BUILD.bazel, could reach develop through a direct push
even though the PR-only workflow would have caught it.

Make ci_test_amalgamation glob the same roots (docs/mkdocs/docs/examples,
include, tests) and extensions (*.hpp, *.cpp, *.cu) as check_amalgamation.yml,
excluding tests/thirdparty/ and tests/abi/include/nlohmann/ the same way, and
regenerate and diff BUILD.bazel next to json.hpp/json_fwd.hpp. Also add
docs/mkdocs/docs/examples/*.hpp to the Makefile's pretty/pretty_format
targets, which were missing the four custom_*_type.hpp example headers, and
drop the stale "called by Travis" comment on check-amalgamation (Travis is
gone; nothing currently calls that Makefile target from CI).

Leaves the workflow itself untouched: it deliberately runs amalgamate.py
from a fresh develop checkout so a PR cannot change the tool that checks it.

Overlaps #5610 and #5621, which each add a new amalgamated header and touch
the same INDENT_FILES/ci_test_amalgamation/check_amalgamation.yml hunks.

Verified with `make check-amalgamation` on this branch: clean, no diff.
#5715 item 5.

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

* Download prebuilt CMake binaries on Linux x86_64 instead of building from source (#5715 item 6)

ci_get_cmake() downloaded the source tarball of CMake 3.5.0, 3.31.6, and
4.0.0 and compiled each one completely (including CMake's own test
helpers) with -DCMAKE_POLICY_VERSION_MINIMUM=3.5 as a workaround for
building old CMake with a newer one. On CI this made the
ci_cmake_options (ci_cmake_flags) job take about 11 minutes, most of it
spent building CMake itself, even though Kitware has published
ready-to-run Linux x86_64 archives for all three of these releases
since 3.20 (lowercase platform name).

On Linux x86_64, download and unpack the prebuilt
cmake-<version>-linux-x86_64.tar.gz archive instead and point the
existing ${var} output at its bin/cmake, skipping the configure/build
steps and CMAKE_POLICY_VERSION_MINIMUM entirely. Keep the previous
source build as a fallback for any other platform (macOS, Linux
aarch64), since Kitware does not publish binaries for every
CMake/platform combination this project might build on.

Verify the downloaded archive against Kitware's own published checksum
before unpacking it: download cmake-<version>-SHA-256.txt alongside the
archive and run `sha256sum -c` on the matching line. A CI job that wgets
and untars a binary from a release page with no integrity check is a
supply-chain gap; Kitware has published this file for every release
since 3.20, so checking it costs one extra download and one grep.

As a separate, mechanical change: the ci_cmake_options job's container
only needed to stay on ubuntu:focal for the source build's
libssl-dev dependency and its own aging toolchain; now that the
Linux/x86_64 path never compiles CMake, drop libssl-dev from its apt
install line and move the job to ubuntu:24.04 (Ubuntu 20.04 left
standard support in May 2025). ci_clean already removes the
cmake-3.5.0/cmake-3.31.6/cmake-4.0.0 directories from the #5715 item 3
fix, and the prebuilt path reuses those same directory names, so no
further cleanup changes are needed.

Overlaps #5598, which edits the same ci_cmake_options matrix line in
ubuntu.yml; a rebase may be needed once that lands.

Verified locally: `cmake -S . -B build -DJSON_CI=On` configures cleanly
on macOS/arm64 (source-build fallback branch) and on Linux/x86_64 in an
ubuntu:24.04 Docker container (47 `ci_cmake_flag_*` targets generated,
one built and run successfully); `.github/workflows/ubuntu.yml` still
parses as valid YAML; downloaded the real v3.31.6 Linux x86_64 archive
and SHA-256 file from Kitware and confirmed the `grep | sha256sum -c`
pipeline both accepts the genuine file and is anchored to the exact
filename (not a prefix match).

CI must confirm: the prebuilt-binary path actually runs on the
ubuntu-latest/ubuntu:24.04 x86_64 runner, all `ci_cmake_options`
entries still pass with the new container's GCC, and the job's
runtime drops from roughly 11 minutes.

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

* Make Infer fail on findings, with a type-level baseline for the ~174 pre-existing ones (#5715 item 4b)

ci_infer ran `infer run` without --fail-on-issue, so the job passed
regardless of what Pulse found; the last recorded run (35829411620,
commit 1054b2097) logged "Found 174 issues" and still went green.
report.txt was also never uploaded, so the full finding list was only
ever visible in the truncated 5-issue console excerpt.

Add a repository-root .inferconfig (auto-discovered by Infer; passing
--project-root on the `infer run` invocation makes sure it is found
even though the analysis runs from build/build_infer) that sets
fail-on-issue and disables the six PULSE issue types that made up all
174 findings in that run: PULSE_UNNECESSARY_COPY_ASSIGNMENT (129),
PULSE_UNNECESSARY_COPY (22), PULSE_UNNECESSARY_COPY_INTERMEDIATE (15),
PULSE_RESOURCE_LEAK (5), PULSE_CONST_REFABLE (2), and
PULSE_UNNECESSARY_COPY_OPTIONAL (1).

This is a deliberate, narrower fix than "triage and fix everything in
this PR": the visible sample is entirely doctest-macro copies in test
code (for example tests/src/unit-algorithms.cpp:141 and
tests/src/unit-bjdata.cpp:3706), but 169 of the 174 findings were never
uploaded anywhere and this PR cannot respectably claim to have fixed
issues it never saw, including the resource-leak and const-refable
ones that are the most likely to be genuine bugs. Disabling by issue
type is a coarser baseline than a per-finding one (Infer has no
built-in per-finding baseline short of the two-run `infer reportdiff`
workflow, which this repository does not have the CI infrastructure
for), but it has the same effect today: the job goes from always green
to green-only-when-clean-of-everything-else, so CI now fails the
moment a *new* issue type appears, and report.txt is uploaded as a
workflow artifact on every run (including failures) so the six
disabled types can be triaged and re-enabled incrementally in follow-up
PRs.

#5715 item 4b. 4a (scan-build) and 4c (IWYU) are handled in separate
commits.

Verified: .inferconfig parses as JSON, ubuntu.yml still parses as
YAML. Infer itself is not available in this environment (v1.3.0 tar.xz
requires a Linux x86_64 runner), so CI must confirm that `infer run
--project-root ... -- make` picks up .inferconfig, that fail-on-issue
takes effect, and that the six disabled types actually suppress the
existing findings without also hiding an unrelated new one.

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

* Fix IWYU findings for json.hpp/json_fwd.hpp/ordered_map.hpp and make CI fail on new ones (#5715 item 4c)

ci_single_binaries ran IWYU via CMake's CXX_INCLUDE_WHAT_YOU_USE launcher
property, which only printed "Warning: include-what-you-use reported
diagnostics" without failing the build: CMake's own __run_co_compile
wrapper does not propagate the launched tool's exit code, so even
`-Xiwyu --error` could never fail `cmake --build` this way. Verified
this empirically by injecting a deliberately-unused #include and
confirming the build still exited 0.

Fix the findings from the last recorded run (issue #5715 item 4, log
35829411620):
- ordered_map.hpp: add <new> (placement new) and
  nlohmann/detail/abi_macros.hpp; drop <memory> (std::allocator is
  still visible transitively via <vector>, confirmed by full local and
  containerized test suite runs).
- json_fwd.hpp: drop <memory> (same reasoning). Keep every forward
  declaration IWYU wanted removed (adl_serializer, basic_json,
  json_pointer, ordered_map): this file's only job is to forward-declare
  them for downstream users, so "nothing in this TU uses them" is
  expected, not a real finding. Mark each with `// IWYU pragma: keep`.
- json.hpp: add <cmath>, <cstdint>, <set>, <type_traits>,
  <unordered_map>, and the detail/abi_macros.hpp, detail/input/json_sax.hpp,
  detail/meta/detected.hpp, thirdparty/hedley/hedley.hpp includes IWYU
  says it needs. Do NOT remove adl_serializer.hpp,
  detail/conversions/from_json.hpp, detail/conversions/to_json.hpp,
  detail/macro_unscope.hpp, or ordered_map.hpp as IWYU suggests: nothing
  else in include/nlohmann includes adl_serializer.hpp or
  ordered_map.hpp, so basic_json<>'s own default template arguments
  (JSONSerializer = adl_serializer, and ordered_json = basic_json<ordered_map>)
  would lose their complete type; detail/macro_unscope.hpp is what
  undoes the JSON_* macros detail/macro_scope.hpp defines earlier in
  this same file, and removing it leaks those macros into every
  translation unit that includes <nlohmann/json.hpp>. Verified by
  actually removing them in a scratch test: the header still "compiles"
  stand-alone but ordered_json and every macro-using translation unit
  break. Marked each `// IWYU pragma: keep`.

Enforce it with `iwyu_tool` (ships with IWYU, e.g. as /usr/bin/iwyu_tool
on Debian/Ubuntu) instead of relying on the launcher property: it reads
compile_commands.json (now exported project-wide under JSON_CI) and
does return a real exit code for its own analysis, independent of
CMake's wrapper. ci_single_binaries now runs it over every
src_single/*.cpp with `-Xiwyu --error`, so a *new* finding fails CI.

json.hpp itself is excluded from that hard gate: even after every fix
above, IWYU's suggestion for one remaining symbol (a container
`swap, operator!=` used somewhere via a templated comparator) is not
deterministic — repeated, otherwise-identical containerized runs
reported <set>, then <unordered_map>, then <map> as "the" header to
add/remove for the exact same source. Gating a whole CI job on a
nondeterministic suggestion would make ci_single_binaries flaky rather
than informative, so json.hpp keeps the existing informational warning
(still shown during its normal compile) without failing the build on
it. Every other one of the ~50 single-header checks is included in the
hard gate.

#5715 item 4c. 4a (scan-build) and 4b (Infer) are separate commits.

Verified: full local ctest suite (129/129) and the ci_single_binaries
target itself both green in a containerized silkeh/clang:dev run
(matching the actual CI job) after this fix; a deliberately-reintroduced
unused #include in ordered_map.hpp was confirmed to fail
`cmake --build ... --target ci_single_binaries` (exit 2) with this
change, and to pass without it, on the same container/IWYU version CI
uses. `make check-amalgamation` is clean. Compiled with Clang and GCC
at -std=c++11/14/17/20 locally with no new warnings.

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-30 22:49:24 +02:00
Niels Lohmann
c261578431 Deduplicate binary reader/writer helpers and fix stale comments (#5730)
* Fix stale and missing comments in binary_writer

The doc block of write_number() ended up above the byte_swap() helpers
added in #5286, about 80 lines from the function. It was also a plain
comment that Doxygen skips, said "write a number to output input", and
left BON8 out of the big-endian formats. Move it back onto
write_number() as a /*! block and fix the text.

write_bson() documented "@pre j.type() == value_t::object", but it
throws type_error.317 for every other type, and to_bson() relies on
that. Document the exception instead.

Explain why the CBOR binary subtype is always written with a 0xD8..0xDB
head and never in the one-byte tag form: binary_reader with
cbor_tag_handler_t::store only keeps those heads as a subtype, so
switching to write_cbor_head() would break round trips for subtypes
0..23.

Also fix the grammar of the to_char_type comment. Comments only; no
change in behavior, API or ABI.

Part of #5710

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

* Merge the duplicated UBJSON/BJData integer marker ladders

write_number_with_ubjson_prefix() (unsigned and signed overloads) and
ubjson_prefix() (number_integer and number_unsigned cases) each picked
the UBJSON/BJData integer marker (i, U, I, u, l, m, L, M, H) with their
own independent if/else ladder, and the values beyond 64 bits were
handled by a second, tag-dispatched pair of ladders. An optimized
container announces the marker of its first element via ubjson_prefix()
and then writes every element through write_number_with_ubjson_prefix(),
so the two had to be kept in lockstep by hand across four call sites.

Replace all of that with one ubjson_integer_prefix() built on
value_in_range_of<T>, and one write_ubjson_integer_payload() that
writes the value (or, for 'H', the decimal digits) for a given marker.
write_number_with_ubjson_prefix() and ubjson_prefix() keep their
signatures and now just call these two helpers.

Behavior, the public API and the ABI are unchanged. Verified with a
new regression test covering scalars and $-optimized arrays/objects at
every int8/uint8/int16/uint16/int32/uint32/int64/uint64 boundary for
to_ubjson/to_bjdata (both use_size/use_type settings), and by diffing
to_ubjson/to_bjdata output before and after over the json_test_data
corpus (bit-identical).

Part of #5710

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

* Remove dead get_char parameters in binary_reader

The non-recursive rewrite of the binary readers (#5505, #5506, #5507)
left parse_cbor_internal()'s and parse_ubjson_internal()'s get_char
parameters dead: parse_cbor_internal() has one caller and it always
passes true, and parse_ubjson_internal() has one caller and it always
uses the true default. Both parameters, and the @param docs describing
the "reuse the last character" mode they used to select, no longer
correspond to anything.

Drop both parameters, initialise fetch/prefix unconditionally, and
update the two call sites in sax_parse(). parse_cbor_value()'s and
get_ubjson_string()'s own get_char parameters are unrelated and are
left alone; both still have a false caller.

Also delete a stray `@return whether a valid MessagePack value was
passed to the SAX parser` doxygen block that sits directly above
parse_msgpack_value()'s real doc comment, a leftover of the same
rewrite.

Behavior, the public API and the ABI are unchanged; these are private
members of detail::binary_reader. Verified by compiling with
-Wunused-parameter and running unit-cbor, unit-ubjson, unit-bjdata and
unit-msgpack (offline, against the stubbed test_data.hpp).

Part of #5711

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

* Share the IEEE half-precision decoder between CBOR and BJData

binary_reader had two ~45-line copies of the IEEE 754 half-precision
decoder: CBOR's case 0xF9 and BJData's case 'h'. Once formatting is
normalised, the two blocks were identical except for the byte order
used to assemble the 16-bit half (CBOR is big endian, BJData is little
endian). Any future change to half-float decoding had to be made and
kept in sync in both places.

Add one get_half_float(format, little_endian) helper that does the two
get()/unexpect_eof() reads, assembles the half in the requested byte
order, decodes it per RFC 8949 Appendix D, and calls sax->number_float.
Both cases now just call it with their byte order; the BJData case
keeps its bjdata-only guard.

Behavior, the public API and the ABI are unchanged. Verified with a
scratch probe comparing the old and new decoders bit-for-bit (NaN by
isnan()) over all 65536 wire byte pairs, in both formats, and by
running unit-cbor and unit-bjdata (offline, against the stubbed
test_data.hpp).

Part of #5711

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

* Deduplicate the MessagePack unsigned-integer writer ladder

The number_integer (non-negative branch) and number_unsigned cases in
write_msgpack() each held their own copy of the fixint/uint8/16/32/64
ladder, kept in lockstep only by a comment ("we used the code from the
value_t::number_unsigned case here"). Both copies mixed union members:
the signed copy compared number_unsigned but wrote number_integer, and
vice versa.

Extract write_msgpack_unsigned(std::uint64_t), mirroring how
write_cbor_head() already avoids the same duplication for CBOR, and
call it from both cases. Each case now reads only its own active
union member. Output bytes are unchanged for the default 64-bit
number types.

#5710 item 3

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

* Unify float marker selection and fix the long double compile error

Four formats picked between a float32 and float64 marker through four
different helper styles: dummy-argument overloads for CBOR and
MessagePack, an std::is_same template for BON8, and a runtime if-chain
on input_format_t for write_compact_float(). With number_float_t set
to long double, to_cbor, to_msgpack and to_ubjson failed inside the
library with "call to 'get_cbor_float_prefix' is ambiguous", while
to_bson kept working because write_bson_double() takes a plain double.

Change write_compact_float() to take the two marker bytes directly
(each of its three callers already knows them at compile time) instead
of an input_format_t it only forwarded, and delete the now-unused
get_cbor_float_prefix(), get_msgpack_float_prefix(),
get_bon8_float_prefix() and get_compact_float_prefix() helpers. Turn
the two get_ubjson_float_prefix() overloads into one template. Both
write_compact_float() and get_ubjson_float_prefix() now report an
unsupported number_float_t with a static_assert naming the requirement,
rather than an ambiguous-overload error; the assert lives in the
function body, not the class scope, so to_bson with long double is
unaffected.

Verified with a probe basic_json<..., long double>: to_bson still
compiles and round-trips, while to_cbor/to_msgpack/to_ubjson now fail
to compile with the new static_assert message.

This changes the text of an existing compile error for users with an
unsupported number_float_t (documented as a public-API-visible change
in #5710).

#5710 item 1

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

* Deduplicate the BJData ndarray writer's dtype dispatch and drop <map>

write_bjdata_ndarray() built a 12-entry std::map<string_t, CharType> on
every call just to translate the _ArrayType_ name to a dtype marker
(the only reason binary_writer.hpp included <map>), then mapped dtype
to C++ type twice more: once as a switch for the range-check pass and
once as a separate if/else chain for the write pass, with nothing
checking that the two agreed. The caller also ran three at() lookups,
and the callee called value.at(key) about ten more times for the same
three members.

Replace the map with bjdata_ndarray_type_marker(), a plain string
comparison chain (a C++11 constexpr function cannot contain a switch,
so this mirrors binary_reader's own static table style). Replace the
switch/if-chain pair with one write_bjdata_ndarray_elements() that
switches on dtype once and calls a per-type helper -
write_bjdata_ndarray_element<T>() for the eight integer dtypes and
write_bjdata_ndarray_float_element() for 'd' - with a dry_run flag
selecting the range check or the actual write, so the two passes can
no longer disagree on the type. _ArrayType_, _ArraySize_ and
_ArrayData_ are now looked up once into references, and the four
header marker bytes ('[', '$', '#') are written through to_char_type()
like the rest of the UBJSON/BJData writer.

The 'd' (single-precision) rule is left exactly as before, since #5707
is expected to change it separately.

Verified byte-for-byte identical output before/after for every dtype
(including the Draft 2/Draft 3 'byte' fallback and the use_count/
use_type combinations) via a standalone probe, plus round-tripping
through from_bjdata().

Overlaps #5707, which is expected to touch the 'd' dtype case, and
#5518, which is expected to move the write_bjdata_ndarray() call site.

#5710 item 4

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

* Assert that write_bson_document() consumes every calc_bson_sizes() entry

calc_bson_sizes() and write_bson_document() are a hand-synchronized
pair of passes over the same object/array tree, introduced by #5553:
the size pass appends to nested_sizes in visiting order, and the write
pass consumes the table by position with nested_sizes[next_size++].
Nothing checked that the write pass consumed the whole table. If a
future change touched only one of the two passes - for example to skip
or reject an entry - every later size prefix in the document would be
silently wrong.

Add JSON_ASSERT(next_size == nested_sizes.size()) where
write_bson_document() returns, so such a future drift between the two
passes is caught immediately (JSON_ASSERT expands to nothing in
release builds using assert(), and the fuzzers/tests already build
with it enabled). The two passes agree today, so this changes nothing
observable; it only guards against the risk described in #5710 item 5.

Extracting a shared stepper for the two passes (the second half of the
proposed change) is left for a follow-up: it only saves ~30 lines and
the issue asks for it only if the result reads clearly, which needs
more room to get right than a mechanical cleanup pass allows.

#5710 item 5

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

* Make the BJData lookup tables static functions instead of members

binary_reader held bjd_optimized_type_markers and bjd_types_map as
non-static const members (12 string_t objects for the type-name table),
built and destroyed on every from_cbor/from_msgpack/from_bson/
from_ubjson/from_bon8/from_bjdata call even though only from_bjdata
ever reads them. They also needed the #define/decltype/#undef
workaround from #3637 and two NOLINTNEXTLINE suppressions, and
binary_writer already carries the same two lists in another form
(is_bjdata_excluded_type_marker() and a local std::map in
write_bjdata_ndarray(), the latter removed by the item-4 commit), so
the excluded-marker lists could drift apart.

Replace bjd_optimized_type_markers with static constexpr
is_bjd_excluded_optimized_type(char_int_type), using the same ||-chain
as binary_writer's is_bjdata_excluded_type_marker(). Replace
bjd_types_map with a non-constexpr static bjd_type_name(char_int_type)
switch returning nullptr for an unknown marker (a C++11 constexpr
function cannot contain a switch). Delete both
JSON_BINARY_READER_MAKE_* macros, the bjd_type pair alias, the
NOLINTNEXTLINE suppressions, detail::make_array() (no longer used
anywhere), and the now-unused <algorithm> and <array> includes.

Update the two call sites (the ND-array excluded-type check and the
_ArrayType_ lookup) accordingly, and replace unit-bjdata.cpp's
"LUT arrays are sorted" section, which only checked the two tables'
internal ordering, with a check of all 12 type names and all 8
excluded markers against both new functions.

#5711 item 1

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

* Read CBOR's 1/2/4/8-byte argument through one helper

parse_cbor_internal() hand-wrote the same "read a 1/2/4/8-byte
big-endian unsigned integer" ladder four times over:
- twice for tag numbers 0xD8-0xDB, once in the tag_handler::ignore
  branch and once, nearly identically, in the ::store branch (~90
  lines to read one integer);
- twice more for container lengths, once for array heads 0x98-0x9B and
  once for map heads 0xB8-0xBB, where the 1/2-byte forms called
  enter_array()/enter_object() directly and the 4/8-byte forms
  additionally went through get_cbor_container_size().

Add get_cbor_argument(std::uint64_t&), reading the width selected by
current & 0x1F via the same get_number() calls as before (so EOF is
reported exactly as before), and route all four sites through it:
- 0xD8-0xDB now read the argument once per branch instead of switching
  on `current` a second time; behavior split cleanly from embedded tags
  0xC0-0xD7 (tag value in the head, no argument to read), which is now
  its own case block that no longer has to fall into the ::store
  switch's "default" case to reach the same tag_pending = true; return
  true; outcome.
- 0x98-0x9B and 0xB8-0xBB collapse into one case block each, always
  going through get_cbor_container_size() (harmless for 1/2-byte
  lengths, which already always fit).

Verified byte-for-byte identical behavior before/after with a
standalone probe covering embedded and multi-byte tags under all three
tag_handler_t settings, a tag over a byte string (subtype path),
truncated tag/length arguments of every width, and array/map lengths
of every width, including the out_of_range.408 "excessive size" case:
same exceptions, same messages, same chars_read, same successful
results.

Left the string/byte-string length ladders in get_cbor_string()/
get_cbor_binary() untouched, as noted in #5711 item 2, since #5325 is
expected to touch them separately.

Overlaps #5601 (adds a branch right above the embedded-tag case) and
#5607 (touches the integer cases 0x18-0x1B, which share this ladder's
shape in separate hunks).

#5711 item 2

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

* Add leave_container() to match enter_container()

Every container is opened through enter_container(), whose docs
promise that a check placed there runs before every start event. The
close side had no equivalent: the same
"container_stack.pop_back(); dispatch to end_object() or end_array()"
sequence was written out separately in BSON, CBOR, MessagePack,
UBJSON/BJData and BON8, each copying the pattern of keeping an
is_object flag around the pop_back() that would otherwise invalidate
a reference to it. A check needed on close would have had to be added
in five places, and a sixth copy could go unnoticed.

Add leave_container() next to enter_container(), doing the same
pop-then-dispatch, and replace the five sites with it. Each site keeps
its own surrounding logic (BSON's check_bson_document_size() call
before popping, MessagePack's is_object copy used again below,
UBJSON/BJData's remaining-container handling after popping, BON8's
top used again below); only the repeated pop/dispatch line pair is
now shared.

Verified all six binary-format unit suites and unit-regression2's
deep-nesting tests (dependent count/reuse count and the bjdata ndarray
depth cases) still pass, compiled with -Wall -Wextra and ASan/UBSan.

Overlaps #5601, which is expected to add a sixth close site in its own
skip loop; that site can route through leave_container() too once it
lands.

#5711 item 4

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

* Stop passing the input format to sax_parse() when the reader already has it

binary_reader's constructor stores the format in the input_format
member, and sax_parse(format, sax_, strict, tag_handler) took the same
value again purely to dispatch on it. Every in-tree caller passed the
same value both times (all 16 from_cbor/from_msgpack/from_ubjson/
from_bjdata/from_bon8/from_bson call sites in json.hpp, and the three
public basic_json::sax_parse() overloads), so nothing was broken
today, but a caller of the detail class directly (only reachable via
JSON_PRIVATE_UNLESS_TESTED, as unit-bjdata.cpp already does) could
pass a mismatched pair - say bjdata to the constructor and ubjson to
sax_parse - and dispatch on one format while applying the other
format's rules; the default-constructed input_format_t::json reader
would additionally hit JSON_ASSERT(false) in exception_message() on
its first error.

Add sax_parse(json_sax_t*, bool, cbor_tag_handler_t) forwarding to the
existing overload with the stored input_format, and switch every
caller to it: the 16 from_*() sites (keeping their
`// cppcheck-suppress[accessMoved]` comments) and the three
basic_json::sax_parse() overloads, all of which already had the format
available from their own `format` parameter. The four-argument overload
is kept for anyone still calling it, now with
JSON_ASSERT(format == input_format) so a mismatch fails immediately
in a debug build (assert-enabled binaries, including the fuzzers and
test suite) instead of misbehaving; verified with a probe that
constructs a reader for one format and calls the explicit overload
with another, which aborts on that assertion as expected.

Removing or asserting against the constructor's input_format_t::json
default, which would affect direct detail users, is left as a separate
decision per #5711 item 5.

Overlaps #5601, which is expected to add an AllowRecovery template
parameter to sax_parse() and touch these same call sites in json.hpp.

#5711 item 5

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

* Deduplicate UBJSON/BJData signed-count handling, drop dead ndarray checks

get_ubjson_size_value()'s 'i'/'I'/'l'/'L' cases each read a differently
sized signed integer and then repeated the same "reject negative with
error 113" check; only 'L' additionally checked value_in_range_of for
the out_of_range.408 case. Any change to that error path had to be
made four times.

Add get_ubjson_signed_count<SignedType>(std::size_t&), doing the read,
the negative check and the range check once, and route all four
markers through it. The range check is a no-op for 'i'/'I'/'l' (their
values always fit std::size_t) and only live for 'L' on a 32-bit
std::size_t target, matching today's behavior exactly.

In the ndarray dimension-product loop, the preceding loop already
returns early on any zero dimension and result starts at 1, so `i > 0`
in the pre-multiplication overflow check was always true, and
`result == 0` in the post-multiplication check could not be reached
either: two positive factors whose product does not overflow (as the
pre-check already guarantees) cannot be zero. Drop the dead `i > 0 &&`
and narrow the post-check to `result == npos`, the one case the
pre-check cannot rule out (an exact, non-overflowing match with the
sentinel reserved for unknown-size containers), with a comment
explaining why.

Verified byte-for-byte identical behavior before/after with a
standalone probe covering negative counts for every marker, a matching
positive count, and ndarray inputs, plus the full unit-ubjson and
unit-bjdata suites (same assertion counts as before this change).

Overlaps #5601 (rewrites the four parse_error calls and the overflow
checks touched here) and #5607/#5707 (touch neighboring lines in the
same functions).

#5711 item 6

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

* Drop redundant format parameter and dummy float argument (review)

binary_reader::sax_parse(format, ...) only ever had to equal the format
given to the constructor, which it asserted. With every caller already
on the format-less overload, remove the four-argument overload and
dispatch on the stored input_format directly. binary_reader is a
detail class, so this is not a public API change.

get_ubjson_float_prefix() took a value only to deduce its type; make
the type an explicit template argument instead.

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-30 22:48:32 +02:00
Niels Lohmann
35802e78d6 Remove dead Makefile targets; document macro_builder; tidy serve_header (#5735)
* Remove dead doctest help entry and pretty_format target from Makefile

The top-level Makefile still carried three leftovers:

- The help text listed a "doctest" target that was removed in #4560,
  so "make doctest" fails with "No rule to make target". The example
  check now runs as "make check_output -C docs".
- "pretty_format" ran clang-format on all sources, but .clang-format
  was deleted in #4573, so the target reformatted everything in the
  default LLVM style, against the Artistic Style formatting that
  "make pretty" applies and CI enforces.
- "clean" removed benchmarks/files/numbers/*.json, a directory that no
  longer exists since the benchmarks moved to tests/benchmarks (#3462).

Only maintainer tooling changes; the library is not affected.

Part of #5717

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

* Document tools/macro_builder and tidy up serve_header.py

tools/macro_builder generates the NLOHMANN_JSON_EXPAND,
NLOHMANN_JSON_GET_MACRO and NLOHMANN_JSON_PASTE* macros in
macro_scope.hpp, but nothing referred to it. Add a README that explains
what it generates, how to run it and where the output goes, and which
dependent tables (NLOHMANN_JSON_DOUBLE_PASTE, NLOHMANN_JSON_TYPE_BODY)
are maintained by hand. Point to it from a comment above
NLOHMANN_JSON_EXPAND. The generator itself is unchanged; following the
README reproduces the header byte for byte.

In serve_header.py, drop the LGTM suppression (LGTM.com shut down in
2022), replace the """.""" placeholder docstrings with real ones, and
import socket and ssl at module level. DualStackServer.server_bind uses
socket, which was only imported under __main__; when the module was
imported instead, the NameError was swallowed and IPV6_V6ONLY was not
cleared.

The header change is a comment only; behavior, API and ABI are
unchanged.

Part of #5717

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

* Hash every release_files artifact, not a hardcoded subset

The `release` target signed and copied json_fwd.hpp into release_files
alongside json.hpp, but the shasum line that writes hashes.txt only
listed json.hpp, include.zip and json.tar.xz. Users could not verify
the published json_fwd.hpp against hashes.txt.

Hash every file in release_files except the .asc signatures instead
of naming files by hand, so a newly shipped header (such as the
json_literals.hpp that #5610 adds to this target) cannot be missed
again.

Only affects the generated hashes.txt release artifact; the library
itself is unaffected.

Overlaps #5610, which touches the same lines to add json_literals.hpp
to the release target.

#5717 item 1

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

* Remove the broken fuzz_testing* Makefile targets

fuzz_testing and fuzz_testing_{bon8,bson,cbor,msgpack,ubjson} seeded
fuzz-testing/testcases from tests/data, which was removed in dbf1a1f41
(2020) when the test data moved to the external json_test_data repo.
The find command found nothing, but the pipeline's exit status was
that of xargs, so the recipe still reported success with an empty
corpus, and the printed afl-fuzz command would refuse to start.

The recipes were also six near-identical copies with unquoted -name
patterns, used the legacy CXX=afl-clang++, and fuzzing-start/stop were
missing from both the help output and .PHONY. tests/fuzzing.md already
documents the working flow (download json_test_data, then
`make -C tests fuzzers`), so replace the six broken targets and their
help lines with a single pointer to that document instead of trying
to keep six copies of a fragile shell pipeline in sync.

This does not affect OSS-Fuzz, which builds through tests/Makefile.

Overlaps #5621, which adds a seventh copy of the same broken line for
fuzz_testing_json_view.

#5717 item 2

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

* Remove stale Travis comment above check-amalgamation

check-amalgamation carried "Note: this target is called by Travis",
left over from before the project switched off Travis CI. The prior
Makefile cleanup commit removed the other stale Travis-era leftovers
(the doctest help entry, pretty_format, and the benchmarks/ path in
clean) but missed this comment.

#5717 item 4

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

* Fix stale install/usage instructions in the vendored amalgamate README

tools/amalgamate/README.md is the unmodified upstream text and no
longer matches how the tool is used here:

- It named a Bitbucket origin that no longer exists; CHANGES.md
  already tracks the GitHub mirror commit this copy is based on.
- It asked for Python 2.7, but CI and the Makefile run the script
  with python3.
- It told readers to run ./test.sh (not vendored) and install to
  /usr/local/bin; in this repository the tool runs through
  `make amalgamate`.
- Its usage synopsis showed `-v` taking no argument, but the script's
  own argparser requires `choices=["yes", "no"]`, so that form fails
  with "argument -v/--verbose: expected one argument". The Makefile
  calls it as `--verbose=yes`.
- It pointed at test/source.c.json and test/include.h.json, which are
  not vendored; the configs actually used are config_json.json and
  config_json_fwd.json.

Rewrote only the Installing and Using sections to match; left the
"Here be dragons" caveats and the rest of the vendored code untouched
to avoid diverging further from upstream.

Overlaps #5615, which edits amalgamate.py, this README and CHANGES.md.

#5717 item 6

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

* Derive generate_natvis.py's ABI tag list and version from abi_macros.hpp

generate_natvis.py hard-coded abi_tags = ['_diag', '_ldvcmp', '_dp',
'_bics', '_psp', '_snul'] and required --version on the command line.
The source of truth is include/nlohmann/detail/abi_macros.hpp: the
NLOHMANN_JSON_ABI_TAG_* defines, the argument order of
NLOHMANN_JSON_ABI_TAGS_CONCAT, and NLOHMANN_JSON_VERSION_MAJOR/MINOR/
PATCH. Nothing checked that the copies stayed in sync, and they have
drifted apart before: _dp was added in #4517 but missed here until
#5544, and 3.11.3 shipped json_abi_v3_11_2 namespaces (#4340).

Parse the tag list (in NLOHMANN_JSON_ABI_TAGS_CONCAT order) and the
version from abi_macros.hpp instead of hard-coding them. Make
--version optional (falling back to the parsed version) and default
the output directory to the repository root the script lives in.

Add a "natvis" Makefile target that runs the script, and extend
check-amalgamation to regenerate nlohmann_json.natvis and fail on a
diff, the same way it already does for the amalgamated headers and
BUILD.bazel. Wire the same regeneration into check_amalgamation.yml,
using the tool copy checked out from develop (as the workflow already
does for amalgamate.py) and installing jinja2 from
tools/generate_natvis/requirements.txt. Update the tool's README to
say it must be re-run after adding an ABI tag or bumping the version.

Verified: a run against develop produces no diff (with either the
default or an explicit --version 3.12.0); adding a dummy
NLOHMANN_JSON_ABI_TAG_* without a matching #define makes the script
fail loudly instead of silently omitting the tag; xmllint --noout
passes on the regenerated file; and running the script from a
directory other than the one being checked (simulating the workflow's
separate tool checkout) against this repository root also produces no
diff.

Overlaps #5600, which added _ekmo to the same hand-written abi_tags
line and regenerated the file.

#5717 item 3

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

* Strip the leading "./" find(1) prefix from release hashes.txt entries

bc6e7db72 (#5717 item 1) switched the release target's shasum line from
naming files by hand to $$(find . -type f -not -name '*.asc' | sort),
so a newly shipped header is hashed automatically. Run from inside
release_files, that find prints paths as "./json.hpp" instead of
"json.hpp", so hashes.txt lists "./json.hpp" etc. instead of the plain
filenames it always used. shasum -c still verifies "./json.hpp" fine,
but it is a needless cosmetic regression for anyone reading the file
or matching it against release notes.

Strip the "./" prefix with sed before sorting, keeping the filenames
exactly as before while still hashing every artifact automatically.

Review fix for #5717 item 1 (PR #5735).

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

* Fix check_amalgamation.yml: pass --version to generate_natvis.py

bff45f111 (#5717 item 3) made --version optional in
tools/generate_natvis/generate_natvis.py and wired the workflow's new
"Regenerate nlohmann_json.natvis" step to call it without --version,
relying on the script deriving the version from abi_macros.hpp itself.

But NATVIS_TOOL_DIR is checked out from develop, the same way TOOL_DIR
already is for amalgamate.py, precisely so an in-flight PR's tooling
changes cannot mark themselves clean. Until this PR (or an equivalent)
merges to develop, that checkout is the old generate_natvis.py, whose
--version argument is still required=True. The new step's invocation
of "generate_natvis.py $MAIN_DIR" (no --version) then fails argparse
on this PR's own CI run with "the following arguments are required:
--version", before the check ever gets to compare output.

Extract the version from $MAIN_DIR's own abi_macros.hpp in the
workflow and always pass it as --version. That satisfies the old
script's required argument and is accepted as an explicit override by
the new one, so the step behaves the same whether NATVIS_TOOL_DIR holds
the pre- or post-merge tool, and stays correct for later PRs that bump
the version.

Verified by running the workflow step's shell logic locally against
both the pre-#5717 generate_natvis.py (checked out at 633de8e44) and
the new one: both produce the identical nlohmann_json.natvis as the
committed file.

Review fix for #5717 item 3 (PR #5735).

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

* Extend tools/macro_builder to also generate DOUBLE_PASTE and TYPE_BODY

tools/macro_builder only emitted NLOHMANN_JSON_EXPAND..PASTE64, so two
other tables that scale with the same max_args stayed hand-maintained
with nothing checking them: NLOHMANN_JSON_DOUBLE_PASTE (added by hand
in #4563 for the *_WITH_NAMES macros) and the 64-slot dispatch table of
NLOHMANN_JSON_TYPE_BODY (the #4041 zero-member/one-or-more-member
switch). Both tables pass one macro name per slot to the same
NLOHMANN_JSON_GET_MACRO dispatch as PASTE, so they can drift out of
sync with max_args exactly the way _dp did in the ABI tag list fixed
by #5544.

Extend main.cpp with build_double_paste_code() (same recursive-doubling
shape as build_paste_code(), but DOUBLE_PASTE consumes two arguments
per member, so an even slot index falls back to the next lower odd
DOUBLE_PASTE<N>) and build_type_body_table() (max_args - 1 MEMBERS
slots and one trailing EMPTY slot, 8 per line, matching how it is
written by hand today). Add a "type_body" argument that selects the
TYPE_BODY block, since it lives at a separate location in
macro_scope.hpp from the EXPAND..DOUBLE_PASTE63 block; plain invocation
is unchanged apart from covering the extended range. No longer emit
the tool's old trailing blank line, so its output is directly diffable
without post-processing.

Verified with c++ -std=c++11: running the tool (with and without
"type_body") and piping the raw output through the pinned astyle
reproduces both blocks of the current macro_scope.hpp byte for byte.
tests/src/unit-udt_macro.cpp (all NLOHMANN_DEFINE_TYPE_*/_WITH_NAMES/
zero-member variants) passes unchanged under -std=c++11 and -std=c++17
with -fsanitize=address,undefined.

Add a "macro_builder_check" Makefile target that builds main.cpp,
regenerates both blocks into a scratch directory inside the repository
(astyle's --project lookup needs the target files under the same tree
as .astylerc, unlike an external /tmp directory), and diffs them
against the corresponding ranges of macro_scope.hpp; wire it into
check-amalgamation next to the natvis check. Wire the same regeneration
into check_amalgamation.yml, splicing the (still unindented) generated
blocks back into the PR's own macro_scope.hpp before the existing
astyle/amalgamation step runs, so that step's own tree-wide astyle
pass both indents them and folds any drift into the amalgamation
patch/diff the workflow already produces.

Unlike amalgamate.py and generate_natvis.py, this step builds
tools/macro_builder/main.cpp from the pull request's own checkout
($MAIN_DIR) rather than a separate checkout of tools/ at develop: this
tool has no independent source of truth to regenerate against (its
README documents that it must reproduce macro_scope.hpp byte for
byte), so a develop-pinned copy would only reproduce the
generate_natvis.py trap fixed in a previous commit on this branch,
where a PR that teaches the tool to cover more of the file fails its
own CI until that PR merges and updates the develop copy.

Add tools/macro_builder/README.md documentation for both new tables
and the two-invocation usage, and a short pointer comment above
NLOHMANN_JSON_TYPE_BODY (the EXPAND pointer already covered the first
block; extended its wording to include DOUBLE_PASTE63).

Closes #5717 item 5 in full, completing what the documentation-only
"Document tools/macro_builder..." commit already on this branch left
open (that commit's README/pointer-comment half stands; it also covers
item 7).

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-30 22:21:27 +02:00
Niels Lohmann
791cd88dfc Fix raw-TeX formulas and other documentation infrastructure debt (#5736)
* Fix math formulas rendering as raw TeX in the published docs

The privacy plugin self-hosts MathJax 2.7.0 but drops its
?config=TeX-MML-AM_CHTML query string, so the rehosted script loads no
input jax and the 10 formulas across 6 pages render as raw TeX to
readers. Remove pymdownx.arithmatex and the MathJax extra_javascript
entry, and rewrite the formulas in plain HTML (<sup>, <i>) instead.
This also drops a nine-year-old third-party script from every page.

Part of #5718

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

* Fix publish_documentation triggers and persist unneeded git credentials

publish_documentation.yml only triggered on docs/mkdocs/** pushes, but
the site also embeds .github/CODE_OF_CONDUCT.md, CONTRIBUTING.md,
SECURITY.md, cmake/{clang,gcc}_flags.cmake, .clang-tidy,
tools/astyle/.astylerc and tests/fmt_formatter/project/main.cpp via
pymdownx.snippets, so changes to those files never republished the
site. Extend the path filter to cover them, and switch runs-on from
the long-pinned ubuntu-22.04 to ubuntu-latest to match
ci_test_documentation.

Also add persist-credentials: false to the checkouts in ci_icpx and
ci_nvhpc (ubuntu.yml) and msvc-vs2026/msvc-arm64 (windows.yml), none
of which pushes with git, matching every other checkout in these
workflows.

Part of #5718

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

* Fix example build: broken debug echo, deprecations hidden for everything

docs/Makefile's debug echo used a space instead of a comma in
$(call cxx_standard ...), so it always printed an empty standard.
Every example was also compiled with -Wno-deprecated-declarations,
which would silently hide an accidental deprecated-API call in any of
them. Factor the duplicated compile flags into EXAMPLE_CPPFLAGS/
EXAMPLE_WARNFLAGS, build with -Werror=deprecated-declarations by
default, and only allow the three examples that intentionally
document deprecated API (the DEPRECATED_EXAMPLES list) to suppress it.

Part of #5718

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

* Fix check_structure.py NOLINT parsing and an off-by-one report line

`line.strip("<!-- NOLINT")` followed by `.strip(" -->")` strips any of
the characters in those sets from both ends, not a literal prefix; it
only happened to work for "Examples". A NOLINT'd section name
starting with N, O, L, I or T (e.g. "Notes", "Template parameters",
"Iterator invalidation", "Literals") was silently mangled, so the
suppression did not apply and the checker could report a spurious
missing/misordered section. Parse the comment with a regex instead.
The same fragile strip() pattern was used for heading text; replace it
with a plain prefix slice. Also fix the admonition_title report, which
used the 0-based line index while every other report in the file uses
lineno+1.

Part of #5718

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

* Fix docset README's non-existent make target and stale fallback URL

The README told readers to run `make nlohmann_json.docset`, but the
Makefile's targets are `all`, `JSON_for_Modern_C++.docset` and
`install_docset_zeal`; the documented command has failed with "No
rule to make target" since #2967 (2021). Point the README at the real
target and folder name. Info.plist's DashDocSetFallbackURL also still
pointed at the old nlohmann.github.io/json/ URL instead of the
canonical https://json.nlohmann.me/ from mkdocs.yml's site_url.

Leave list_missing_pages/list_removed_paths alone: they may become
redundant once #5638's check_docset() lands, which is a follow-up.

Part of #5718

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

* Remove two leftover Doxygen-era .link files from the examples directory

parse__iterator_pair.link and parse__pointers.link each held only a
Wandbox "online" permalink from the old Doxygen docs. #3071 deleted
every other .link file in 2021; these two came in through a parallel
PR (#3100) and were never referenced by any page, script or config.

Part of #5718

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

* Fix MacPorts CMake example to include its own snippet files

The MacPorts "Example: CMake" block included
integration/homebrew/example.cpp and
integration/homebrew/CMakeLists.txt instead of the MacPorts files
right next to it, a copy-paste slip from the Homebrew section. Nothing
referenced integration/macports/CMakeLists.txt as a result. The page
rendered correctly only because the homebrew, macports and
vcpkg/CMakeLists.txt snippets are byte-identical, so a future edit to
the MacPorts files would not have shown up on the page.

Part of #5718 item 6

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

* Do not persist git credentials in publish_documentation's checkout

The checkout step in publish_documentation.yml left the default
persist-credentials: true, so GITHUB_TOKEN stayed writable in
.git/config for the rest of the job (zizmor's artipacked finding). The
Deploy documentation step authenticates through its own github_token
input to peaceiris/actions-gh-pages and does not push with the
checked-out credentials, so persist-credentials: false is safe here,
matching every other checkout in the workflow set.

Overlaps #5638, which edits this same checkout step (adds
fetch-depth: 0); expect a rebase conflict there.

Part of #5718 item 2

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

* Replace list_missing_pages/list_removed_paths with a comm(1)-based diff

The docset Makefile's list_missing_pages ran one sqlite3 query per
mkdocs page, and list_removed_paths nested a loop over all mkdocs pages
inside a loop over all docset index paths (O(n*m) shell iteration).
Issue #5718 item 5 suggested removing or reducing these targets once
#5638's check_docset() lands, but that PR is still open and covers only
API pages and macros, not the full page set these targets check.
Replace the loops with two sorted path lists (DOCSET_PAGE_PATHS from
mkdocs' markdown sources, DOCSET_INDEX_PATHS from the built docset
index) compared with a single comm(1) call each, verified to produce
output identical to the old loops against the current docSet.dsidx.

The sed expression used '#' as its delimiter, which GNU Make reads as
a comment character even inside a variable assignment, truncating the
line and orphaning the closing paren of $(shell ...) ("unterminated
call to function 'shell': missing ')'"). Use '@' as the delimiter
instead.

Part of #5718 item 5

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-30 22:15:20 +02:00
Niels Lohmann
7d7055ec50 Fix stack overflow converting deep values between specializations (#5723)
* Fix stack overflow converting deep values between specializations

Constructing a basic_json from another specialization (json to
ordered_json or back, also via get<ordered_json>()) converted every
container with its range constructor, which calls the converting
constructor for each element. The call stack therefore grew with every
nesting level, and a value nested some 30,000 levels deep overflowed it.

The conversion now bounds its descent the way the copy constructor does
since #5387: the first 128 levels are converted exactly as before, and
below that convert_iteratively() finishes the value with an explicit
stack. It builds each container bottom-up from its converted elements
with the container's range constructor, so member order and keys that
become equal are handled as before, and it gives a value its type only
once its container exists, so an exception leaves nothing behind that
cannot be destroyed. Parents (JSON_DIAGNOSTICS) and positions
(JSON_DIAGNOSTIC_POSITIONS) are set for every value.

Converting a null value no longer resets its positions: the constructor
assigned null to a value that already was null, which swapped in the
positions of the temporary.

Fixes #5650.

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

* Explain why converting null keeps positions and why next is a reference

Review feedback on #5723 (gregmarr): clarify in comments that the
converting constructor has already copied the positions of val, which
the null case keeps like every other case, and that next must be a
reference into pending so that ++next advances the stored iterator.

Comments only; no code change.

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

* Refer to recursion_depth_limit() in the convert_structured() docs

The comment still named nesting_depth_limit, which #5637 removed on
develop in favor of detail::recursion_depth_limit().

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

* Advance the pending iterator through pending.back() and shorten the null comment

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-30 21:36:04 +02:00
Niels Lohmann
0a97d94497 Fix CI: useless cast in the Zmij digit writer and snprintf truncation
- ci_test_gcc (Linux x86-64): static_cast<std::size_t>(d.significand % 100)
  was a useless cast (a std::uint64_t prvalue, the same type as
  std::size_t there); cast a named variable instead.
- ci_test_gcc: -Werror=format-truncation for snprintf("%.*e") in
  unit-to_chars.cpp, whose precision GCC cannot bound; write the
  neighboring decimal with a stream (classic locale, std::scientific),
  which gives the same text.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-30 21:02:19 +02:00
Niels Lohmann
bee66ec810 Write doubles with the shortest digits (Zmij)
dump() writes doubles with the conversion of Zmij by Victor Zverovich
(https://github.com/vitaut/zmij, MIT), ported to C++11 in
detail/conversions/zmij.hpp: the shortest decimal in the rounding
interval, the closest one if there are several. Grisu2 does not always
find the shortest digits; about 0.14% of random doubles are now written
differently (0.08% with fewer digits, 0.06% with the closest last
digit); short decimals such as 0.1 or 2555.56 are not affected. float
keeps Grisu2.

The layout of doubles is unchanged, but written differently: the digits
are converted eight at a time (the BCD conversion of Xiang JunBo, as in
Zmij) and stored with one byte swap per eight digits; leading and
trailing zeros are counted from those bytes; and the layouts of
format_buffer() are written with fixed-size moves instead of per-digit
loops and moves of the buffer (to_chars() uses a local buffer if the
caller's is shorter than the 41 bytes this may write).

The powers of ten come from the table for number parsing, adjusted
where it holds them rounded up, and from the compressed tables of Zmij
beyond 10^308. json::dump() gets faster on floats: canada -53%,
numbers -46%, mesh -37%, marine_ik -30%.

Tests: the powers of ten recomputed with a small big-integer; for random
doubles, all powers of two and of ten and their neighbors, and boundary
values: the output reads back as the same value, no decimal with one
digit fewer does, the layout equals that of format_buffer() for the same
digits, and (C++17) the digits equal those of std::to_chars.
The size ratios of canada.json in unit-binary_formats.cpp and one
expectation in unit-to_chars.cpp change with the shorter output.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-30 21:02:18 +02:00