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Niels Lohmann
f8e99e856c
* Test ci_cuda_example against a CUDA version matrix at C++20 (#3907) The ci_cuda_example job compiled against the json-ci image's CUDA 11.0 toolkit at cuda_std_11, which cannot exercise #3907 (a c++20 parse error in iteration_proxy.hpp's enable_borrowed_range reported under nvcc). Switch the job to pull official nvidia/cuda devel images directly and matrix across CUDA 11.8-12.6 at cuda_std_20 so CI can empirically confirm which versions are actually affected before any source-level fix is attempted. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Fix nvcc CUDA 12.0/12.1 C++20 ranges parse error (#3907) The diagnostic matrix in this PR confirmed the affected range exactly: nvcc 12.0.1 and 12.1.1 both fail with "expected initializer before '<' token" on iteration_proxy.hpp's enable_borrowed_range variable template specialization at -std=c++20; 12.2.2 and newer already build cleanly. Guard JSON_HAS_RANGES off for that narrow nvcc version range, matching the existing GCC-11/libstdc++ carve-outs in the same ifdef chain, and regenerate single_include accordingly. Broaden the CUDA smoke test to also exercise comparisons (operator==/operator<=>, gated independently by JSON_HAS_THREE_WAY_COMPARISON) and range-based iteration, not just dump()/erase(), so the fix's actual scope is evidenced by CI rather than assumed from the single reported symptom. Have tests/cuda_example/CMakeLists.txt pick the newest C++ standard the detected nvcc version actually supports (20/17/11) instead of hard-requiring C++20, so older toolkits build at a lower standard instead of failing CMake configure outright. This is test-project-local only; the JSON_HAS_RANGES guard is what protects real client code, since a header can't control what -std= flag it's compiled with. Right-size the CI matrix from the 8-version diagnostic sweep down to 11.8.0 (C++17 fallback path) / 12.1.1 (permanent #3907 regression guard) / 12.6.3 (recent coverage), and update the compiler-version table in the quality assurance docs to match. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Fix ci_cuda_example CUDA 11.8 build after C++17 fallback (#3907) The 11.8.0 leg's graceful C++17 fallback (added in the previous commit) worked correctly, but the broadened smoke test used the <=> operator unconditionally, which isn't valid syntax pre-C++20 — nvcc rejected it with "expected an expression" once the CMake logic picked cuda_std_17 for the older toolkit. Gate those two lines behind JSON_HAS_THREE_WAY_COMPARISON like the library itself does internally. Sanity-compiled the file as plain C++ at both -std=c++17 (skips the guarded block) and -std=c++20 (includes it) locally; the actual nvcc build is verified via CI on PR #5248. Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me>
22 lines
762 B
CMake
22 lines
762 B
CMake
cmake_minimum_required(VERSION 3.18)
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project(json_cuda LANGUAGES CUDA)
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add_executable(json_cuda json_cuda.cu)
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target_include_directories(json_cuda PRIVATE ../../include)
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# nvcc added C++20 support in CUDA 12.0 and C++17 in CUDA 11.0; pick the
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# newest standard the detected compiler actually supports (see #3907)
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# instead of hard-requiring one standard for every CUDA version.
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if(CMAKE_CUDA_COMPILER_VERSION VERSION_GREATER_EQUAL 12.0)
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set(json_cuda_std 20)
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elseif(CMAKE_CUDA_COMPILER_VERSION VERSION_GREATER_EQUAL 11.0)
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set(json_cuda_std 17)
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else()
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set(json_cuda_std 11)
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endif()
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target_compile_features(json_cuda PUBLIC cuda_std_${json_cuda_std})
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set_target_properties(json_cuda PROPERTIES
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CUDA_EXTENSIONS OFF
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CUDA_STANDARD_REQUIRED ON
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)
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