GCC may produce false warnings in some cases when working with strings (char*) when -Wstringop-overflow is enabled. The patch fixes the compilation warning that origins in some tricky pointers casts.

The error message:

g++ -Wall -Wpointer-arith -Wendif-labels -Wmissing-format-attribute -Wimplicit-fallthrough=3 -Wcast-function-type -Wshadow=compatible-local -Wformat-security -fno-strict-aliasing -fwrapv -g -O2 -fPIC -fvisibility=hidden -fvisibility-inlines-hidden -DPGSPHERE_VERSION=1.3.1 -I. -I./ -I/home/vit/p.pgsphere/local/include/postgresql/server -I/home/vit/p.pgsphere/local/include/postgresql/internal -D_GNU_SOURCE -fopenmp -I/usr/include/healpix_cxx -c -o src/process_moc.o src/process_moc.cpp -MMD -MP -MF .deps/process_moc.Po In file included from /usr/include/string.h:535, from /usr/include/c++/11/cstring:42, from src/process_moc.cpp:2: In function ‘void* memmove(void*, const void*, size_t)’, inlined from ‘void rpage_iter<V, page_size, value_size>::set(const V&) [with V = moc_interval; long unsigned int page_size = 1996; long unsigned int value_size = 16]’ at src/process_moc.cpp:336:15, inlined from ‘void create_moc_release_context(void*, Smoc*, pgs_error_handler)’ at src/process_moc.cpp:604:9: /usr/include/x86_64-linux-gnu/bits/string_fortified.h:36:34: warning: writing 16 bytes into a region of size 2 [-Wstringop-overflow=] 36 | return __builtin___memmove_chk (__dest, __src, __len, | ~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~ 37 | __glibc_objsize0 (__dest)); | ~~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from src/process_moc.cpp:19: src/pgs_process_moc.h: In function ‘void create_moc_release_context(void*, Smoc*, pgs_error_handler)’: src/pgs_process_moc.h:58:25: note: destination object ‘Smoc::version’ of size 2 58 | uint16 version; /* version of the 'toasty' MOC data structure */