Files
json/tests/CMakeLists.txt
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

371 lines
16 KiB
CMake

cmake_minimum_required(VERSION 3.13...4.0)
option(JSON_Valgrind "Execute test suite with Valgrind." OFF)
option(JSON_FastTests "Skip expensive/slow tests." OFF)
option(JSON_TestSimdutf "Build the unit tests against the simdutf UTF-8 validation backend." OFF)
set(JSON_SIMDUTF_VERSION 9.1.0 CACHE STRING "The simdutf version used by JSON_TestSimdutf.")
set(JSON_32bitTest AUTO CACHE STRING "Enable the 32bit unit test (ON/OFF/AUTO/ONLY).")
set(JSON_TestStandards "" CACHE STRING "The list of standards to test explicitly.")
# using an env var, since this will also affect targets executing cmake (such as "ci_test_compiler_default")
if (NOT "" STREQUAL "$ENV{JSON_FORCED_GLOBAL_COMPILE_OPTIONS}")
add_compile_options($ENV{JSON_FORCED_GLOBAL_COMPILE_OPTIONS})
endif()
if (NOT "" STREQUAL "$ENV{JSON_FORCED_GLOBAL_LINK_OPTIONS}")
add_link_options($ENV{JSON_FORCED_GLOBAL_LINK_OPTIONS})
endif()
include(test)
#############################################################################
# override standard support
#############################################################################
# Clang only supports C++14 starting from Clang 3.5 (lesser versions miss std::enable_if_t)
if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang" AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 3.5)
unset(compiler_supports_cpp_14)
endif()
# Clang only supports C++17 starting from Clang 5.0
if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang" AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 5.0)
unset(compiler_supports_cpp_17)
endif()
# MSVC 2015 (14.0) does not support C++17
if (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC" AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 19.10)
unset(compiler_supports_cpp_17)
endif()
# GCC 5 and 6 do claim experimental support for C++17, but do not implement <optional>
if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU" AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 7.0)
unset(compiler_supports_cpp_17)
endif()
# Clang C++20 support appears insufficient prior to Clang 9.0 (based on CI build failure)
if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang" AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 9.0)
unset(compiler_supports_cpp_20)
endif()
# MSVC 2017 (15.x) does not support C++20
if (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC" AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 19.20)
unset(compiler_supports_cpp_20)
endif()
# GCC started supporting C++20 features in 8.0 but a test for #3070 segfaults prior to 9.0
if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU" AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 9.0)
unset(compiler_supports_cpp_20)
endif()
#############################################################################
# test_main library with shared code to speed up build and common settings
#############################################################################
add_library(test_main OBJECT src/unit.cpp)
target_compile_definitions(test_main PUBLIC
DOCTEST_CONFIG_SUPER_FAST_ASSERTS
JSON_TEST_KEEP_MACROS
JSON_TEST_USING_MULTIPLE_HEADERS=$<BOOL:${JSON_MultipleHeaders}>)
target_compile_features(test_main PRIVATE cxx_std_11)
target_compile_options(test_main PUBLIC
$<$<CXX_COMPILER_ID:MSVC>:/EHsc>
# MSVC: Force to always compile with W4
# Disable warning C4566: character represented by universal-character-name '\uFF01'
# cannot be represented in the current code page (1252)
# Disable warning C4996: 'nlohmann::basic_json<...>::operator <<': was declared deprecated
# Disable warning C4702: unreachable code; wide_string_input_adapter::get_elements()
# is annotated JSON_HEDLEY_NO_RETURN (it always throws), which
# makes MSVC flag the code following its call in binary_reader.hpp
# as unreachable for that instantiation, in both Debug and Release
# Disable warning C4503: decorated name length exceeded, name was truncated; the deep
# copy support added for #5387 pushes the mangled name of
# std::allocator_traits<...>::construct for the custom-base-class
# test's map type past VS2015's limit. The name is only used for
# debug info, so truncation does not affect the build.
# Disable warning C5285: cannot declare a specialization for 'std::tuple'; MSVC 19.51
# reports the forward declarations of standard library
# templates in the vendored doctest.h
$<$<CXX_COMPILER_ID:MSVC>:/W4;/wd4566;/wd4996;/wd4702;/wd4503;/wd5285>
# https://github.com/nlohmann/json/issues/1114
$<$<CXX_COMPILER_ID:MSVC>:/bigobj> $<$<BOOL:${MINGW}>:-Wa,-mbig-obj>
# https://github.com/nlohmann/json/pull/3229
$<$<CXX_COMPILER_ID:Intel>:-diag-disable=2196>
$<$<CXX_COMPILER_ID:GNU>:-Wno-deprecated-declarations>
$<$<CXX_COMPILER_ID:Intel>:-diag-disable=1786>)
target_include_directories(test_main SYSTEM PUBLIC
thirdparty/doctest)
target_include_directories(test_main PUBLIC
${PROJECT_BINARY_DIR}/include)
target_link_libraries(test_main PUBLIC ${NLOHMANN_JSON_TARGET_NAME})
# thirdparty/fifo_map is only used by the #972 regression test, so only
# test-regression1 needs it on its include path (see json_test_set_test_options
# below), rather than every test-* target via test_main.
add_library(fifo_map_include INTERFACE)
target_include_directories(fifo_map_include INTERFACE thirdparty/fifo_map)
#############################################################################
# define test- and standard-specific build settings
#############################################################################
if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU"
AND CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 8.0
AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 9.0 AND NOT MINGW)
# fix for https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90050
json_test_set_test_options(all CXX_STANDARDS 17 LINK_LIBRARIES stdc++fs)
endif()
if (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
# avoid stack overflow, see https://github.com/nlohmann/json/issues/2955
json_test_set_test_options("test-bon8;test-cbor;test-msgpack;test-ubjson;test-bjdata;test-binary_formats" LINK_OPTIONS /STACK:4000000)
endif()
# disable exceptions for test-disabled_exceptions
json_test_set_test_options(test-disabled_exceptions
COMPILE_DEFINITIONS
JSON_NOEXCEPTION
# disabled due to https://github.com/nlohmann/json/discussions/2824
#$<$<CXX_COMPILER_ID:MSVC>:_HAS_EXCEPTIONS=0>
COMPILE_OPTIONS
$<$<CXX_COMPILER_ID:AppleClang>:-fno-exceptions> $<$<CXX_COMPILER_ID:Clang>:-fno-exceptions>
$<$<CXX_COMPILER_ID:GNU>:-fno-exceptions>
$<$<CXX_COMPILER_ID:Intel>:-fno-exceptions> $<$<CXX_COMPILER_ID:IntelLLVM>:-fno-exceptions>
# disabled due to https://github.com/nlohmann/json/discussions/2824
#$<$<CXX_COMPILER_ID:MSVC>:/EH>
)
# raise timeout of expensive Unicode test
json_test_set_test_options(test-unicode4 TEST_PROPERTIES TIMEOUT 3000)
# only the #972 regression test needs thirdparty/fifo_map on its include path
json_test_set_test_options(test-regression1 LINK_LIBRARIES fifo_map_include)
#############################################################################
# add unit tests
#############################################################################
# Generate the leak checks for every JSON_HEDLEY_* macro defined in
# hedley.hpp; tests/src/unit-no-macro-leak.cpp #include-s the result after
# nlohmann/json.hpp (see issue #5408). Using the shared
# cmake/scripts/gen_hedley_undef_check.cmake script (also used by `make
# update_hedley_undef`) instead of a hand-maintained list of macro names
# means this test can never go stale after a future `make update_hedley`.
set(hedley_hpp "${PROJECT_SOURCE_DIR}/include/nlohmann/thirdparty/hedley/hedley.hpp")
set(hedley_undef_check_script "${PROJECT_SOURCE_DIR}/cmake/scripts/gen_hedley_undef_check.cmake")
set(hedley_undef_checks "${PROJECT_BINARY_DIR}/include/hedley_undef_checks.inc")
# Reconfigure whenever the vendored header or the generator script changes,
# so a `cmake --build` after `make update_hedley` does not silently keep a
# stale generated file around.
set_property(DIRECTORY APPEND PROPERTY CMAKE_CONFIGURE_DEPENDS
"${hedley_hpp}"
"${hedley_undef_check_script}")
# Generate once at configure time, so the very first build (before any
# custom-command build step has run) already has an up-to-date file.
execute_process(
COMMAND ${CMAKE_COMMAND}
"-DHEDLEY_HPP=${hedley_hpp}"
"-DOUTPUT=${hedley_undef_checks}"
-DMODE=checks
-P "${hedley_undef_check_script}"
RESULT_VARIABLE hedley_undef_check_result
)
if(NOT hedley_undef_check_result EQUAL 0)
message(FATAL_ERROR "Failed to generate ${hedley_undef_checks}")
endif()
# Also (re)generate as a build step, so an incremental build after editing
# hedley.hpp without a full reconfigure still picks up the change.
add_custom_command(
OUTPUT "${hedley_undef_checks}"
COMMAND ${CMAKE_COMMAND}
"-DHEDLEY_HPP=${hedley_hpp}"
"-DOUTPUT=${hedley_undef_checks}"
-DMODE=checks
-P "${hedley_undef_check_script}"
DEPENDS "${hedley_hpp}" "${hedley_undef_check_script}"
COMMENT "Generating Hedley undef leak checks"
VERBATIM)
add_custom_target(generate_hedley_undef_checks DEPENDS "${hedley_undef_checks}")
if("${JSON_TestStandards}" STREQUAL "")
set(test_cxx_standards 11 14 17 20 23)
unset(test_force)
else()
set(test_cxx_standards ${JSON_TestStandards})
set(test_force FORCE)
endif()
# Print selected standards marking unavailable ones with brackets
set(msg_standards "")
foreach(cxx_standard ${test_cxx_standards})
if(compiler_supports_cpp_${cxx_standard})
list(APPEND msg_standards ${cxx_standard})
else()
list(APPEND msg_standards [${cxx_standard}])
endif()
endforeach()
string(JOIN " " msg_standards ${msg_standards})
set(msg "Testing standards: ${msg_standards}")
if(test_force)
string(APPEND msg " (forced)")
endif()
message(STATUS "${msg}")
#############################################################################
# optionally validate UTF-8 with simdutf (JSON_USE_SIMDUTF)
#############################################################################
# The simdutf backend is opt-in and not vendored, so it is fetched here rather
# than being a checked-in dependency. Everything below hangs off test_main,
# whose usage requirements every test target inherits; the library target and
# the installed CMake package are deliberately left untouched.
if (JSON_TestSimdutf)
# simdutf requires C++17, both to compile itself and to be reachable from
# the library, which keeps its scalar validator below that. Find a tested
# standard that satisfies it.
set(simdutf_standard "")
foreach(cxx_standard ${test_cxx_standards})
if(NOT cxx_standard LESS 17 AND compiler_supports_cpp_${cxx_standard})
set(simdutf_standard ${cxx_standard})
break()
endif()
endforeach()
if("${simdutf_standard}" STREQUAL "")
# Building simdutf would fail outright without a C++17 compiler, and
# even with one it would go unused if no C++17-or-later standard is
# tested. Say so and fall back to the scalar validator rather than
# failing the build.
if(NOT compiler_supports_cpp_17)
set(simdutf_reason "the compiler does not support C++17")
else()
set(simdutf_reason "no tested standard is C++17 or later (testing ${msg_standards})")
endif()
message(WARNING
"JSON_TestSimdutf is enabled, but ${simdutf_reason}. simdutf requires C++17, so it "
"is not fetched and JSON_USE_SIMDUTF is not defined: the tests run against the "
"built-in scalar UTF-8 validator instead. Set JSON_TestStandards to include 17 or "
"later, or build with a compiler that supports C++17.")
else()
if (CMAKE_VERSION VERSION_LESS 3.18)
message(FATAL_ERROR "JSON_TestSimdutf requires CMake 3.18 or later (simdutf's minimum).")
endif()
include(FetchContent)
# simdutf builds its tests and tools by default, and its tests pull
# further dependencies of their own; only the library is needed here
set(SIMDUTF_TESTS OFF CACHE BOOL "" FORCE)
set(SIMDUTF_TOOLS OFF CACHE BOOL "" FORCE)
set(SIMDUTF_BENCHMARKS OFF CACHE BOOL "" FORCE)
set(SIMDUTF_ICONV OFF CACHE BOOL "" FORCE)
FetchContent_Declare(simdutf
URL https://github.com/simdutf/simdutf/archive/refs/tags/v${JSON_SIMDUTF_VERSION}.tar.gz
DOWNLOAD_EXTRACT_TIMESTAMP TRUE
)
FetchContent_MakeAvailable(simdutf)
target_compile_definitions(test_main PUBLIC JSON_USE_SIMDUTF)
target_link_libraries(test_main PUBLIC simdutf::simdutf)
# simdutf.h requires C++17; below that the library keeps its scalar
# validator, so any C++11/14 test targets exercise the fallback and the
# C++17-and-later ones exercise simdutf. Both must agree.
message(STATUS "UTF-8 validation delegated to simdutf ${JSON_SIMDUTF_VERSION} for C++17 and later (JSON_USE_SIMDUTF)")
endif()
endif()
# *DO* use json_test_set_test_options() above this line
json_test_should_build_32bit_test(json_32bit_test json_32bit_test_only "${JSON_32bitTest}")
file(GLOB files CONFIGURE_DEPENDS src/unit-*.cpp)
if(json_32bit_test_only)
set(files src/unit-32bit.cpp)
elseif(NOT json_32bit_test)
list(FILTER files EXCLUDE REGEX src/unit-32bit.cpp)
endif()
foreach(file ${files})
json_test_add_test_for(${file} MAIN test_main CXX_STANDARDS ${test_cxx_standards} ${test_force})
endforeach()
# tests/src/unit-no-macro-leak.cpp #include-s the generated leak-check file,
# so its test targets must be built after generate_hedley_undef_checks.
foreach(cxx_standard ${test_cxx_standards})
if(TARGET test-no-macro-leak_cpp${cxx_standard})
add_dependencies(test-no-macro-leak_cpp${cxx_standard} generate_hedley_undef_checks)
endif()
endforeach()
if(json_32bit_test_only)
# Skip all other tests in this file
return()
endif()
# test legacy comparison of discarded values
json_test_set_test_options(test-comparison_legacy
COMPILE_DEFINITIONS JSON_USE_LEGACY_DISCARDED_VALUE_COMPARISON=1
)
json_test_add_test_for(src/unit-comparison.cpp
NAME test-comparison_legacy
MAIN test_main CXX_STANDARDS ${test_cxx_standards} ${test_force}
)
# test the parser again with JSON_DIAGNOSTIC_POSITIONS enabled
json_test_set_test_options(test-class_parser_diagnostic_positions
COMPILE_DEFINITIONS JSON_DIAGNOSTIC_POSITIONS=1
)
json_test_add_test_for(src/unit-class_parser.cpp
NAME test-class_parser_diagnostic_positions
MAIN test_main CXX_STANDARDS ${test_cxx_standards} ${test_force}
)
# test diagnostic positions again without regular diagnostics (JSON pointer paths)
json_test_set_test_options(test-diagnostic-positions_only
COMPILE_DEFINITIONS JSON_DIAGNOSTICS=0
)
json_test_add_test_for(src/unit-diagnostic-positions.cpp
NAME test-diagnostic-positions_only
MAIN test_main CXX_STANDARDS ${test_cxx_standards} ${test_force}
)
# *DO NOT* use json_test_set_test_options() below this line
#############################################################################
# test ABI compatibility
#############################################################################
add_subdirectory(abi)
#############################################################################
# Test the generated build configs
#############################################################################
# these tests depend on the generated file nlohmann_jsonConfig.cmake
if (JSON_Install)
add_subdirectory(cmake_import)
add_subdirectory(cmake_import_minver)
endif()
add_subdirectory(cmake_add_subdirectory)
add_subdirectory(cmake_fetch_content)
add_subdirectory(cmake_fetch_content2)
add_subdirectory(cmake_target_include_directories)
# fmt (fetched by tests/fmt_formatter) requires a genuinely modern, C++17-capable
# toolchain; skip it on legacy/niche toolchains where fmt itself is known not to build
set(JSON_FMT_FORMATTER_TEST_SUPPORTED ${compiler_supports_cpp_17})
# fmt 12's 128-bit integer emulation does not build with 32-bit MinGW
if (MINGW AND CMAKE_SIZEOF_VOID_P EQUAL 4)
set(JSON_FMT_FORMATTER_TEST_SUPPORTED FALSE)
endif()
# the MSVC STL rejects Clang versions older than 19 as a host compiler
if (WIN32 AND CMAKE_CXX_COMPILER_ID STREQUAL "Clang" AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 19.0)
set(JSON_FMT_FORMATTER_TEST_SUPPORTED FALSE)
endif()
if (JSON_FMT_FORMATTER_TEST_SUPPORTED)
add_subdirectory(fmt_formatter)
endif()