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json/tests/CMakeLists.txt
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Niels Lohmann 855f511db4 Fix stale Clang -Weverything suppression comments; drop -Wno-missing-noreturn (#5250)
* Fix stale Clang -Weverything suppression comments; eliminate -Wno-missing-noreturn

cmake/clang_flags.cmake claimed -Wno-unsafe-buffer-usage was needed only
for Doctest and that -Wno-missing-noreturn had "no way to silence...
otherwise" (PR #4871, which never actually attempted a source fix).
Neither held up under investigation (todo 130):

- -Wno-unsafe-buffer-usage is pervasive (208 distinct sites across 19
  files measured with clang trunk in silkeh/clang:dev), spanning the
  library's own low-level numeric/buffer code (to_chars, serializer,
  lexer, binary reader/writer, input adapters, json_pointer) as well as
  vendored Doctest itself (96 of the 208 sites). A source-level fix is
  not feasible at this scale; the comment now says so instead of
  blaming Doctest alone.

- -Wno-missing-noreturn had exactly two real trigger sites, both
  genuinely and unconditionally non-returning: a test-only throwing
  allocator (tests/src/unit-allocator.cpp) and, previously undiscovered,
  wide_string_input_adapter::get_elements<T>() in
  include/nlohmann/detail/input/input_adapters.hpp. Verified this isn't
  a wider pattern by checking all 160 JSON_THROW call sites in the
  library for functions whose entire body is an unconditional throw.
  Annotated both ([[noreturn]] in the test file, since JSON_HEDLEY_NO_RETURN
  is #undef'd by the time test code runs; JSON_HEDLEY_NO_RETURN in the
  library file, its first real use anywhere in the codebase) and
  dropped the suppression entirely.

single_include/nlohmann/json.hpp regenerated via `make amalgamate`;
`make check-amalgamation` passes.

Verified in Docker (silkeh/clang:dev, matching the ci_static_analysis_clang
CI job): baseline builds clean, and the full 194-target test suite builds
with zero warnings under the corrected CLANG_CXXFLAGS (-Wno-missing-noreturn
no longer in the list). Also sanity-compiled and ran unit-allocator.cpp and
unit-wstring.cpp on host Apple Clang to confirm behavior is unchanged.

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

* Fix MSVC C4702 warning caused by JSON_HEDLEY_NO_RETURN on get_elements()

PR #5250 annotated wide_string_input_adapter::get_elements<T>() with
JSON_HEDLEY_NO_RETURN (it unconditionally throws). On MSVC this expands to
__declspec(noreturn), and MSVC correctly determined that the code following
its call in binary_reader.hpp is unreachable for that instantiation, firing
C4702 under /W4 /WX in the msvc, msvc-vs2026, and msvc-arm64 Debug jobs.

Clang doesn't flag this case, so the Docker verification for #5250 (which
only checked Clang -Weverything) didn't catch it.

This is the same warning class already tolerated for Release builds since
PR #5216, where MSVC's optimizer independently found the same dead code
after /Od was removed. Extend that existing /wd4702 suppression to Debug
builds too, instead of reverting the noreturn annotation.

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-07-09 20:18:28 +02:00

217 lines
9.1 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)
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")
set(JSON_FORCED_GLOBAL_COMPILE_OPTIONS $ENV{JSON_FORCED_GLOBAL_COMPILE_OPTIONS})
if (NOT "" STREQUAL "$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
$<$<CXX_COMPILER_ID:MSVC>:/W4;/wd4566;/wd4996;/wd4702>
# 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>
$<$<NOT:$<CXX_COMPILER_ID:MSVC>>:-Wno-deprecated;-Wno-float-equal>
$<$<CXX_COMPILER_ID:GNU>:-Wno-deprecated-declarations>
$<$<CXX_COMPILER_ID:Intel>:-diag-disable=1786>)
target_include_directories(test_main PUBLIC
thirdparty/doctest
thirdparty/fifo_map
${PROJECT_BINARY_DIR}/include)
target_link_libraries(test_main PUBLIC ${NLOHMANN_JSON_TARGET_NAME})
#############################################################################
# define test- and standard-specific build settings
#############################################################################
if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU"
AND CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 8.0
AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 9.0 AND NOT MINGW)
# fix for https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90050
json_test_set_test_options(all CXX_STANDARDS 17 LINK_LIBRARIES stdc++fs)
endif()
if (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
# avoid stack overflow, see https://github.com/nlohmann/json/issues/2955
json_test_set_test_options("test-cbor;test-msgpack;test-ubjson;test-bjdata;test-binary_formats" LINK_OPTIONS /STACK:4000000)
endif()
# disable exceptions for test-disabled_exceptions
json_test_set_test_options(test-disabled_exceptions
COMPILE_DEFINITIONS
JSON_NOEXCEPTION
# disabled due to https://github.com/nlohmann/json/discussions/2824
#$<$<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)
#############################################################################
# add unit tests
#############################################################################
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}")
# *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()
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}
)
# *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()