Bruno Haible <br...@clisp.org> writes: > While testing a GNU sed snapshot on macOS 10.13, I see this test failure: ... > ==85029== Invalid read of size 16 ... > An out-of-bounds read. Oh oh. When I reconfigure and recompile with the > environment variable > gl_cv_func_working_getdelim=no > this test succeeds. Assuming that the GNU sed code is correct (it's not a > particularly complex code), this proves that the out-of-bounds read comes > from the macOS getdelim() function. ... > + [case "$host_os" in > + darwin*) > + dnl On macOS 10.13, valgrind detected an out-of-bounds read during > + dnl the GNU sed test suite: > + dnl Invalid read of size 16 > + dnl at 0x100EE6A05: _platform_memchr$VARIANT$Base (in > /usr/lib/system/libsystem_platform.dylib) > + dnl by 0x100B7B0BD: getdelim (in > /usr/lib/system/libsystem_c.dylib) > + dnl by 0x10000B0BE: ck_getdelim (utils.c:254) > + gl_cv_func_working_getdelim=no ;;
I don't care strongly about this issue, but this brings up a design perspective for gnulib wrt valgrind: we have several valgrind suppression files (see lib/*.valgrind) to silence valgrind complaints already. Your solution here choses a different path. It can be difficult to assess wether a valgrind complaint is a false positive or not, especially for system functions (and we've had valgrind complaints for libc issues that looked problematic in theory but not in practice). Unless we can trigger a real bug in the code and test for that, we have a choice how to handle valgrind complaints: 1) add a valgrind suppressions file for the complaint, or 2) unconditionally bring in a gnulib replacement code without testing for that behaviour. I prefer 1) since 2) will over time leads to us bringing in the entire gnulib replacement code on all systems, which is really bloated and leads to other problems. What do you think about adding a valgrind suppressions file for the output you found instead? And possibly improve documentation about how gnulib intends these suppression files to be used by people who run the test-suite under valgrind, if anything is missing in that area today. /Simon
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