Commit Graph
47 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 d6660cf718 Route hand-rolled diagnostic pragmas through Hedley (#5485)
* Route hand-rolled diagnostic pragmas through Hedley

Several places in the library hand-roll compiler diagnostic suppression
with raw `#pragma`/`#ifdef __GNUC__`/`#ifdef __clang__` guards instead of
using the Hedley primitives already bundled and used elsewhere
(JSON_HEDLEY_DIAGNOSTIC_PUSH/POP, JSON_HEDLEY_PRAGMA, ...). Converted six
of the seven listed push/pop pairs to use those primitives instead of
raw `#pragma GCC diagnostic`/`#pragma clang diagnostic` text:

- include/nlohmann/json.hpp (~3770, ~3863): -Wfloat-equal
- include/nlohmann/detail/conversions/to_chars.hpp (~1078): -Wfloat-equal
- include/nlohmann/detail/output/binary_writer.hpp (~1844): -Wfloat-equal
- include/nlohmann/detail/iterators/iteration_proxy.hpp (~211): -Wmismatched-tags
- include/nlohmann/detail/exceptions.hpp (~36): -Wweak-vtables

iteration_proxy.hpp did not previously include macro_scope.hpp itself
(it only compiled because some other header included earlier in
json.hpp happened to pull macro_scope.hpp in first); it now includes it
directly like the other detail headers that use Hedley macros, so it is
self-contained.

Each push/pop pair now uses JSON_HEDLEY_DIAGNOSTIC_PUSH/POP
unconditionally (a no-op on compilers that don't need it) and wraps the
actual `#pragma ... diagnostic ignored` text in JSON_HEDLEY_PRAGMA so it
goes through Hedley's _Pragma()-based emission instead of a raw #pragma
line, while keeping the original `#ifdef __GNUC__` / `#if
defined(__clang__)` guard around the ignored-pragma itself.

Deviation from the issue's suggested transformation: the issue's example
replaces the `#ifdef __GNUC__` guard with `#if
JSON_HEDLEY_HAS_WARNING("-Wfloat-equal")`. JSON_HEDLEY_HAS_WARNING is
implemented purely via Clang's `__has_warning` builtin and evaluates to
0 on real GCC (`#define JSON_HEDLEY_HAS_WARNING(warning) (0)` when
`__has_warning` is not defined), so adopting it verbatim would silently
stop suppressing -Wfloat-equal on GCC -- a real regression, not just a
style change. The existing `#ifdef __GNUC__` / `#if defined(__clang__)`
guards were kept for the ignored-pragma to stay behavior-preserving, and
only the push/pop/pragma-emission mechanism was routed through Hedley.

Two of the seven locations from the issue (the -Wignored-attributes
push at the very top of json.hpp and its matching pop after
`#include <nlohmann/detail/macro_unscope.hpp>`) were intentionally left
unconverted:
- The push, at the very top of json.hpp, runs before
  `detail/macro_scope.hpp` (and therefore hedley.hpp) has been included
  anywhere in the translation unit, so JSON_HEDLEY_DIAGNOSTIC_PUSH is not
  yet defined at that point.
- The pop runs after `macro_unscope.hpp`, which -- via hedley_undef.hpp
  -- has already #undef'd every JSON_HEDLEY_* macro (by design, see
  #5408) precisely so they don't leak to users, so JSON_HEDLEY_DIAGNOSTIC_POP
  is no longer defined by the time the pop is reached either.
  Making this one pair work would require either hoisting the ~2000
  line vendored hedley.hpp to the very top of the amalgamated single
  header (a much bigger structural change to single_include than a pure
  mechanism swap) or special-casing this one pop ahead of the general
  macro cleanup. Both are riskier than the mechanical, behavior-preserving
  change requested, so this pair was left as-is.

## Validation

- Compiled include/nlohmann/json.hpp and single_include/nlohmann/json.hpp
  with `-Wall -Wextra -Wfloat-equal -Wmismatched-tags -Wweak-vtables`
  (clang, which self-identifies as __GNUC__ too): no warnings, same as
  before the change.
- Compiled and ran tests/src/unit-to_chars.cpp, unit-conversions.cpp,
  unit-iterators1.cpp, unit-iterators2.cpp, and unit-class_parser.cpp
  against the fixed include/: all pass.
- Compiled unit-msgpack.cpp, unit-bjdata.cpp, and unit-ubjson.cpp (which
  exercise binary_writer.hpp's write_compact_float extensively): all
  compile cleanly; the vast majority of assertions pass (the only
  failures are pre-existing environment issues unrelated to this change
  -- missing generated test-data files, not code correctness).
- Ran `make amalgamate`; the single_include diff is limited to exactly
  the lines touched in include/, with no unrelated reordering.
- No real (non-Apple) GCC was available in this environment to test
  directly; the `_Pragma("GCC diagnostic ...")` text emitted by
  JSON_HEDLEY_PRAGMA is byte-identical to the prior `#pragma GCC
  diagnostic ...` text, and the `#ifdef __GNUC__` guard is unchanged, so
  GCC's behavior is expected to be identical. CI covers the GCC matrix.

This PR is stacked on top of #5475 (issue-5408-hedley-undef-leak) since
both touch the same files; only the last commit here is new.

Fixes #5409.

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

* Guard JSON_HEDLEY_DIAGNOSTIC_PUSH/POP with the same compiler check as the pragma they bracket

Addresses review feedback from @gregmarr on PR #5485: the push/pop calls
were unconditional, so compilers other than the one the ignored-pragma
targets (e.g. MSVC, or GCC where the pair only applies under __clang__)
now did a needless push/pop with nothing suppressed in between. Move the
existing #ifdef __GNUC__ / #if defined(__clang__) guard to also cover the
push/pop, restoring the original zero-overhead behavior on other compilers
while still emitting the pragma itself through Hedley.

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-09 09:48:18 +02:00
Niels Lohmann 515d994acb 📄 adjust year (#5044)
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-01-01 20:00:39 +01:00
Niels Lohmann 54be9b04f0 📄 update REUSE (#4960) 2025-10-23 06:56:36 +02:00
Niels Lohmann 1705bfe914 🔖 set version to 3.12.0 (#4727)
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2025-04-11 10:41:14 +02:00
Niels Lohmann f06604fce0 Bump the copyright years (#4606)
* 📄 bump the copyright years

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

* 📄 bump the copyright years

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

* 📄 bump the copyright years

Signed-off-by: Niels Lohmann <niels.lohmann@gmail.com>

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
Signed-off-by: Niels Lohmann <niels.lohmann@gmail.com>
2025-01-19 17:04:17 +01:00
Niels Lohmann 6057b31df7 Overwork astyle call (#4573)
* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* Use ubuntu-latest image to run Valgrind (#4575)

* 🔧 use Clang image to run valgrind

* 🔧 use Clang image to run valgrind

* 🔧 use Clang image to run valgrind

* 🔧 use Ubuntu image to run valgrind

* Use Clang image to run iwyu (#4574)

* 🔧 use Clang image to run iwyu

* 🔧 use Clang image to run iwyu

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🎨 format code

* 🔨 clean up
2024-12-29 17:06:03 +01:00
Niels Lohmann 620034ecec ♻️ allow patch and diff to be used with arbitrary string types (#4536) 2024-12-13 07:24:50 +01:00
Niels Lohmann 1b9a9d1f21 Update licenses (#4521)
* 📄 update licenses

* 📄 update licenses
2024-11-29 17:38:42 +01:00
Captain Crutches fde9a86c5a Make iterator_proxy_value a forward_iterator (#4371) (#4372)
* Make iteration_proxy_value model forward_iterator

* Amalgamate

* Suppress tidy warning
2024-11-15 09:28:40 +01:00
Niels Lohmann 9cca280a4d JSON for Modern C++ 3.11.3 (#4222) 2023-11-28 22:36:31 +01:00
Niels Lohmann f56c6e2e30 Update documentation for the next release (#4216) 2023-11-26 15:51:19 +01:00
Niels Lohmann 836b7beca4 Fix CI, again (#4083) 2023-09-07 20:41:12 +02:00
Niels Lohmann ab06fc9951 Fix Clang-Tidy warnings (#4047) 2023-06-08 18:46:48 +02:00
Niels Lohmann f7973f46d6 Use official Clang/GCC containers (#3703) 2022-08-27 17:28:50 +02:00
Niels Lohmann 9d69186291 🔖 set version to 3.11.2 2022-08-12 15:04:06 +02:00
Niels Lohmann f2020da0dd 🔖 set version to 3.11.1 2022-08-01 23:27:58 +02:00
Niels Lohmann ce0e13ccea 🔖 set version to 3.11.0 2022-07-31 23:19:06 +02:00
Florian Albrechtskirchinger d909f80960 Add versioned, ABI-tagged inline namespace and namespace macros (#3590)
* Add versioned inline namespace

Add a versioned inline namespace to prevent ABI issues when linking code
using multiple library versions.

* Add namespace macros

* Encode ABI information in inline namespace

Add _diag suffix to inline namespace if JSON_DIAGNOSTICS is enabled, and
_ldvcmp suffix if JSON_USE_LEGACY_DISCARDED_VALUE_COMPARISON is enabled.

* Move ABI-affecting macros into abi_macros.hpp

* Move std_fs namespace definition into std_fs.hpp

* Remove std_fs namespace from unit test

* Format more files in tests directory

* Add unit tests

* Update documentation

* Fix GDB pretty printer

* fixup! Add namespace macros

* Derive ABI prefix from NLOHMANN_JSON_VERSION_*
2022-07-30 21:59:13 +02:00
Niels LohmannandFlorian Albrechtskirchinger 527da54dcb Use REUSE framework (#3546)
* 📄 add licenses

* 👷 add REUSE compliance check

* 📝 add badge for REUSE

Co-authored-by: Florian Albrechtskirchinger <falbrechtskirchinger@gmail.com>
2022-07-20 12:38:07 +02:00
Florian Albrechtskirchinger 6b97599a27 Fix C++20/gcc-12 issues (Part 2) (#3446)
* Add C++20 3-way comparison operator and fix broken comparisons

Fixes #3207.
Fixes #3409.

* Fix iterators to meet (more) std::ranges requirements

Fixes #3130.
Related discussion: #3408

* Add note about CMake standard version selection to unit tests

Document how CMake chooses which C++ standard version to use when
building tests.

* Update documentation

* CI: add legacy discarded value comparison

* Fix internal linkage errors when building a module
2022-05-29 13:08:06 +02:00
Ferry Huberts 44d60f8d14 All: fix warnings when compiling with -Wswitch-enum
Signed-off-by: Ferry Huberts <ferry.huberts@pelagic.nl>
2021-08-12 16:33:50 +02:00
Niels Lohmann 6f551930e5 🚨 add new CI and fix warnings (#2561)
* ⚗️ move CI targets to CMake
* ♻️ add target for cpplint
* ♻️ add target for self-contained binaries
* ♻️ add targets for iwyu and infer
* 🔊 add version output
* ♻️ add target for oclint
* 🚨 fix warnings
* ♻️ rename targets
* ♻️ use iwyu properly
* 🚨 fix warnings
* ♻️ use iwyu properly
* ♻️ add target for benchmarks
* ♻️ add target for CMake flags
* 👷 use GitHub Actions
* ⚗️ try to install Clang 11
* ⚗️ try to install GCC 11
* ⚗️ try to install Clang 11
* ⚗️ try to install GCC 11
* ⚗️ add clang analyze target
* 🔥 remove Google Benchmark
* ⬆️ Google Benchmark 1.5.2
* 🔥 use fetchcontent
* 🐧 add target to download a Linux version of CMake
* 🔨 fix dependency
* 🚨 fix includes
* 🚨 fix comment
* 🔧 adjust flags for GCC 11.0.0 20210110 (experimental)
* 🐳 user Docker image to run CI
* 🔧 add target for Valgrind
* 👷 add target for Valgrind tests
* ⚗️ add Dart
* ⏪ remove Dart
* ⚗️ do not call ctest in test subdirectory
* ⚗️ download test data explicitly
* ⚗️ only execute Valgrind tests
* ⚗️ fix labels
* 🔥 remove unneeded jobs
* 🔨 cleanup
* 🐛 fix OCLint call
* ✅ add targets for offline and git-independent tests
* ✅ add targets for C++ language versions and reproducible tests
* 🔨 clean up
* 👷 add CI steps for cppcheck and cpplint
* 🚨 fix warnings from Clang-Tidy
* 👷 add CI steps for Clang-Tidy
* 🚨 fix warnings
* 🔧 select proper binary
* 🚨 fix warnings
* 🚨 suppress some unhelpful warnings
* 🚨 fix warnings
* 🎨 fix format
* 🚨 fix warnings
* 👷 add CI steps for Sanitizers
* 🚨 fix warnings
* ⚡ add optimization to sanitizer build
* 🚨 fix warnings
* 🚨 add missing header
* 🚨 fix warnings
* 👷 add CI step for coverage
* 👷 add CI steps for disabled exceptions and implicit conversions
* 🚨 fix warnings
* 👷 add CI steps for checking indentation
* 🐛 fix variable use
* 💚 fix build
* ➖ remove CircleCI
* 👷 add CI step for diagnostics
* 🚨 fix warning
* 🔥 clean Travis
2021-03-24 07:15:18 +01:00
Niels Lohmann 6d4eed5aeb 🚨 fix warning 2021-01-30 12:51:54 +01:00
Niels Lohmann ffdeb77468 🚨 fix warnings #2615 2021-01-27 12:54:46 +01:00
Niels Lohmann dc06f100be Merge branch 'develop' of https://github.com/nlohmann/json into clang_windows
 Conflicts:
	include/nlohmann/detail/input/binary_reader.hpp
	include/nlohmann/detail/input/json_sax.hpp
	include/nlohmann/detail/input/lexer.hpp
	include/nlohmann/detail/input/parser.hpp
	include/nlohmann/detail/json_pointer.hpp
	include/nlohmann/detail/output/serializer.hpp
	include/nlohmann/json.hpp
	single_include/nlohmann/json.hpp
2020-07-11 14:04:40 +02:00
Niels Lohmann 98b1c6d302 🚩 use JSON_ASSERT(x) instead of assert(x) 2020-07-06 12:22:31 +02:00
Niels Lohmann ac3922c7aa Merge branch 'develop' of https://github.com/nlohmann/json into clang_windows
 Conflicts:
	include/nlohmann/detail/input/binary_reader.hpp
	include/nlohmann/detail/input/input_adapters.hpp
	include/nlohmann/detail/input/lexer.hpp
	include/nlohmann/detail/output/binary_writer.hpp
	include/nlohmann/json.hpp
	single_include/nlohmann/json.hpp
2020-06-27 13:14:48 +02:00
chenguoping 0ecf297457 drop std::enable_if part 2020-06-23 09:14:55 +08:00
chenguoping aeef50709e to allow for ADL in int_to_string() function 2020-06-22 20:17:56 +08:00
chenguoping 691fb0c57a fix issue#2059 2020-06-16 15:35:26 +08:00
Niels Lohmann 0498202a03 🎨 replace alternative operators (and, not, or) 2020-06-03 14:20:36 +02:00
Thomas Braun 35b47c2793 iteration_proxy: Fix integer truncation from std::size_t to int
Bug introduced in 0f073e26 (Allow items() to be used with custom string,
2019-09-26).
2019-10-16 20:00:05 +02:00
Julien Hamaide 4615f5a980 Provide default implementation for int_to_string, but allow for overloaded function 2019-10-01 10:34:21 +02:00
Julien Hamaide 0f073e26eb Allow items() to be used with custom string 2019-09-26 13:20:57 +02:00
Niels Lohmann b8451c236f 🚨 fixed warnings 2019-03-17 12:01:49 +01:00
Niels Lohmann 27011e3718 🚨 fixed warnings 2019-03-15 14:55:13 +01:00
past-due 45819dce54 Disable -Wmismatched-tags warning on tuple_size / tuple_element 2019-01-30 12:59:50 -05:00
Niels Lohmann e5753b14a8 🚨 fixed another linter warning #1400
Closes #1400.
2019-01-13 15:40:49 +01:00
Niels Lohmann 45f5611d9b 🚨 fixed two warnings 2018-12-20 22:41:48 +01:00
Pratik Chowdhury ebd3f45808 Added Support for Structured Bindings
For further details, read https://github.com/nlohmann/json/issues/1388 and https://blog.tartanllama.xyz/structured-bindings/
2018-12-19 20:17:52 +05:30
Niels Lohmann 858e75c4df 🚨 fixed some clang-tidy warnings 2018-10-07 18:39:18 +02:00
Niels Lohmann 86a96b059d Merge pull request #1134 from Daniel599/feature/items_iterator
fixed compile error for #1045
2018-06-28 21:21:17 +02:00
Niels Lohmann 481ace65c4 🔨 only calculate array index string when needed #1098 2018-05-27 12:04:22 +02:00
Niels Lohmann 90eb0a91e0 ⚡ keys are now returned as const reference #1098 2018-05-26 13:26:40 +02:00
Niels Lohmann 8d8f890771 💩 first try on #1045 2018-04-10 08:29:07 +02:00
Théo DELRIEU 14cd019861 fix cmake install directory (for real this time)
* Rename 'develop' folder to 'include/nlohmann'
* Rename 'src' folder to 'single_include/nlohmann'
* Use <nlohmann/*> headers in sources and tests
* Change amalgamate config file
2018-02-01 11:06:51 +01:00