Hi Marc, When running the gnulib tests with clang's UndefinedBehaviorSanitizer, I got this output in test-hamt.log:
../../gllib/hamt.c:685:41: runtime error: shift exponent 65 is too large for 64-bit type 'size_t' (aka 'unsigned long') SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior ../../gllib/hamt.c:685:41 in PASS test-hamt (exit status: 0) How to reproduce: 1. Install clang 13. 2. Set CC, CXX, CFLAGS, CXXFLAGS: CC="clang -fsanitize=undefined,signed-integer-overflow,shift,integer-divide-by-zero -fno-sanitize=pointer-overflow"; \ CXX="clang++ -L/usr/lib/gcc/x86_64-linux-gnu/9 -I/usr/include/c++/9 -I/usr/include/x86_64-linux-gnu/c++/9 -fsanitize=undefined,signed-integer-overflow,shift,integer-divide-by-zero -fno-sanitize=pointer-overflow"; \ CFLAGS="-O1 -fno-omit-frame-pointer -ggdb"; \ CXXFLAGS="-O1 -fno-omit-frame-pointer -ggdb"; \ export CC CXX CFLAGS CXXFLAGS (The set of -I options in CXX depend on your local g++ installation.) 3. Prepare a gnulib testdir. 4. Configure, make, make check 5. Search the *.log files for 'UndefinedBehaviorSanitizer'. Bruno
