Two changes roughly halve the CPU time needed to build the unit tests
(clang 21: ~300 s -> ~150 s, GCC 16: ~750-820 s -> ~395-420 s, Debug):
- Move the C++14/17/20-dependent tests into separate
unit-<name>-cpp<N>.cpp files. A test file is built for every standard
whose JSON_HAS_CPP_<N> macro it mentions, so far whole large files were
rebuilt for C++14/17/20 because of a few #ifdef sections. The main files
are now built for C++11 only; the ci_test_*_cxx<N> jobs still build
every file for every standard.
- Add the CMake option JSON_TestUnityBuild (ON by default, OFF with
MinGW): compatible test files are compiled in batches as one
translation unit so they share the template instantiations of the
library. Each file keeps its own CTest test, which runs the batch
executable filtered to that file's test cases. The binary-format tests
form an explicit group; the rest is batched by JSON_TestUnityBatchSize.
Fix the name clashes that merging files exposed, document the rules for
test files in tests/README.md, and point CONTRIBUTING.md to it.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* Store maps with enum keys as objects (opt-in)
Maps with enum keys, such as std::map<E, T>, are stored as arrays of
[key, value] pairs, because enums are not convertible to the string type
of object keys - even if NLOHMANN_JSON_SERIALIZE_ENUM maps them to
strings (#4378).
The new JSON_USE_OBJECTS_FOR_ENUM_KEYED_MAPS macro stores them as objects
instead, converting each key with the enum's to_json. It applies to any
map-like type with enum keys (std::map with any comparator,
std::unordered_map, ...). A key that does not convert to a string throws
type_error.302, and two keys converting to the same string throw the new
type_error.318, rather than losing an entry. The macro changes the output
of inline functions, so it is part of the ABI tag (_ekmo).
Reading needs no macro: std::map and std::unordered_map with enum keys
are now also read from objects, converting each key with the enum's
from_json. That input was rejected before, and arrays of pairs are still
read, so data written either way can be read.
This supersedes #4531, which first proposed storing these maps as
objects.
Co-authored-by: Muhammad Amir bin Mohamad Ghazaly <amirghaz@umich.edu>
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* Keep multimaps with enum keys as arrays of pairs
With JSON_USE_OBJECTS_FOR_ENUM_KEYED_MAPS, is_enum_keyed_map also matched
std::multimap and std::unordered_multimap. Storing them as objects throws
type_error.318 as soon as a key occurs twice, which is the normal case for
a multimap, so such values could no longer be serialized at all once the
macro was enabled, although they are stored losslessly as arrays of
[key, value] pairs without it.
Exclude maps with non-unique keys from is_enum_keyed_map. They are
detected by insert(value_type) returning an iterator rather than a
pair<iterator, bool>. Map-like types without such an insert() are still
treated as before.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* Move the default enum-keyed map tests out of unit-conversions.cpp
The Windows clang 20.1.8 job (MinGW, Debug) failed to link
test-conversions_cpp17 with "relocation truncated to fit:
IMAGE_REL_AMD64_REL32 against .rdata": the object file of
unit-conversions.cpp was already close to the limit, and the new
"maps with enum keys" test case pushed it over. windows.yml asks to keep
these objects small by splitting test files.
Move the test case unchanged into unit-enum_keyed_maps_default.cpp,
with the three enums it needs. It still honors a -D flag for
JSON_USE_OBJECTS_FOR_ENUM_KEYED_MAPS, as before. unit-conversions.cpp
is back to its state on develop.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* Build the enum-keyed map test object instead of parsing it
ci_test_diagnostic_positions failed in unit-enum_keyed_maps_default.cpp:
with JSON_DIAGNOSTIC_POSITIONS, a parsed value adds its byte range to
the exception message ("(bytes 0-7) type must be array, but is
object"), so the exact-message checks did not match. Build the object
in memory, like unit-custom-array-type.cpp does.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
---------
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
Co-authored-by: Muhammad Amir bin Mohamad Ghazaly <amirghaz@umich.edu>
Niels Lohmann
