Commit Graph
2 Commits
Author SHA1 Message Date
Niels Lohmann e5a89d671f Fix lint debt: enum-macro NOLINTs, doctest as SYSTEM, no-op analyzer (#5737)
* Drop stale LCOV_EXCL_LINE from the json_pointer out_of_range.410 throw

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

Part of #5725

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

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

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

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

Part of #5725

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

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

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

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

Part of #5725

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

* Remove the no-op ci_clang_analyze target

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

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

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

Part of #5725

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

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

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

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

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

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

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

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

Part of #5725

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

* Fix stale and malformed NOLINT comments

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

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

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

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

#5725 item 10

* Remove stale .clang-tidy entries

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

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

#5725 item 11

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

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

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

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

#5725 item 9

* Fix stale doxygen comments hidden by the -Wdocumentation pragma

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

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

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

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

#5725 item 2

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

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

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

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

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

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

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

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

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

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

#5725 item 8 (step 2 of 2)

* Switch ci_static_analysis_clang off the frozen LLVM 22 dev image

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

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

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

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

#5725 item 5

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

* Regenerate cmake/gcc_flags.cmake for GCC 16.2.0

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

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

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

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

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

#5725 item 7

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

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

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

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

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

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

#5725 item 2 (step a)

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

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

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

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

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

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

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

#5725 item 2 (step c)

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

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

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

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

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

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 07:37:47 +02:00
Niels Lohmann 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