Foundation Dependency

Foundation package resolution and compatibility contract.

Collaboration diagram for Foundation Dependency:

Foundation package resolution and compatibility contract.

MCC links Foundation::Foundation publicly and requires Foundation 2.0.10 or a newer 2.x release. Foundation 2 builds on CPSTL 1.1.12 or newer, which a Foundation package carries or finds; Arduino users install the CPSTL library next to Foundation. MCC rejects a package whose recorded platform differs from the selected MCC preset.

Resolution order (cmake/MCCFoundation.cmake):

1. A Foundation::Foundation target defined by a parent project.
2. -DMCC_FOUNDATION_PREFIX=<prefix> or the MCC_FOUNDATION_PREFIX environment variable. An unusable explicit prefix is an error.
3. ../Foundation/dist/<preset> for sibling repositories. An incompatible sibling export is ignored with a warning.
4. Normal find_package(Foundation CONFIG) search rules.
5. When MCC_FETCH_FOUNDATION is ON (default):
   • the GitHub Release package Foundation-<version>-<preset> for tag v<version>, verified against its published SHA-256 file;
   • otherwise the Foundation sources at that tag, fetched with FetchContent and built with MCC's toolchain. Installing MCC then also installs Foundation into the same prefix.

Fetched content lives in build/<preset>/_deps/ and is reused across reconfigurations. FETCHCONTENT_SOURCE_DIR_FOUNDATION builds a local Foundation working copy instead of cloning, and -DMCC_FETCH_FOUNDATION=OFF disables network access.