[Sunrisepeak]

compat.xz is a static library. On Windows lzma.h declares every function imported from a DLL unless LZMA_API_STATIC is defined, and the module's units read it without: a program that imports the module calls through __imp_lzma_*. No DLL provides those, so lld-link makes a slot of its own for each, and it does not count such a slot as a reference. In a link that collects unreferenced sections (-ffunction-sections, the release profile) the functions are dropped and each slot holds the image's first byte.

Found in mcpp: mcpp pack --compress xz:<level> and its unit test faulted on Windows (EXCEPTION_ACCESS_VIOLATION at the image base) once its dependency objects were rebuilt; the link's map names the five slots, __imp_lzma_end, __imp_lzma_code, __imp_lzma_easy_buffer_encode, __imp_lzma_stream_decoder, __imp_lzma_stream_buffer_bound.

• tools/surface.toml states defines = ["LZMA_API_STATIC"]; the generator writes it before lzma.h in both module units, in tests/macros.cpp and in <mwrap/xz/macros.hpp>, which a unit that includes lzma.h itself includes first.
• tests/linked.cpp reads that the functions are not at one address: slots whose functions were dropped all hold the same one, which is not null.
• CI runs the tests in the release profile as well as the dev profile. 5.8.3 passed the dev profile on Windows.
• docs/usage.md: what a unit that includes lzma.h beside the module states.

The version is a wrapper revision of upstream 5.8.3 (mcpp-index docs/mwrap.md).