fix: propagate HDF5_IS_PARALLEL to parent scope for SZ3Config

[ayzk]

Summary

Fixes Copilot review comment on PR #126: HDF5_IS_PARALLEL was not available in the parent scope when configure_package_config_file processes SZ3Config.cmake.in.

Changes

• tools/H5Z-SZ3/CMakeLists.txt: Added set(HDF5_IS_PARALLEL ${HDF5_IS_PARALLEL} PARENT_SCOPE) to propagate the variable set by find_package(HDF5) to the parent scope.

Verified

Both import methods tested:

• find_package(SZ3) + SZ3::hdf5sz3: PASS
• FetchContent + hdf5sz3: PASS

[Copilot]

Pull request overview

This PR fixes a scope issue identified in PR #126 where HDF5_IS_PARALLEL was not available in the parent scope when configure_package_config_file processes SZ3Config.cmake.in. The variable is set by find_package(HDF5) in the tools/H5Z-SZ3 subdirectory but needed in the parent scope for template substitution.

Changes:

• Propagate HDF5_IS_PARALLEL from subdirectory scope to parent scope using PARENT_SCOPE

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[Copilot]

When BUILD_H5Z_FILTER is OFF (the default), this subdirectory is not included (main CMakeLists.txt line 95-98), so HDF5_IS_PARALLEL remains undefined. The configure_package_config_file call (main CMakeLists.txt line 122) will substitute @HDF5_IS_PARALLEL@ with an empty string in SZ3Config.cmake.in line 6, resulting in invalid CMake syntax if(). This will cause errors for downstream projects using find_package(SZ3) when SZ3 is built with the default configuration.

Consider initializing HDF5_IS_PARALLEL to FALSE in the main CMakeLists.txt before line 95 (the BUILD_H5Z_FILTER conditional), ensuring it has a valid value even when the H5Z-SZ3 subdirectory is not included.