https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105013
--- Comment #4 from James Allwright <jamesallwright at yahoo dot co.uk> --- I have re-run with the suggested options --track-origins=yes and -s : $ valgrind --track-origins=yes -s ./bug ==16956== Memcheck, a memory error detector ==16956== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al. ==16956== Using Valgrind-3.15.0 and LibVEX; rerun with -h for copyright info ==16956== Command: ./bug ==16956== out = command = ==16956== Conditional jump or move depends on uninitialised value(s) ==16956== at 0x1092DB: example_func (bug.c:37) ==16956== by 0x1090D3: main (bug.c:44) ==16956== Uninitialised value was created by a stack allocation ==16956== at 0x109280: example_func (bug.c:26) ==16956== ==16956== ==16956== HEAP SUMMARY: ==16956== in use at exit: 0 bytes in 0 blocks ==16956== total heap usage: 1 allocs, 1 frees, 1,024 bytes allocated ==16956== ==16956== All heap blocks were freed -- no leaks are possible ==16956== ==16956== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0) ==16956== ==16956== 1 errors in context 1 of 1: ==16956== Conditional jump or move depends on uninitialised value(s) ==16956== at 0x1092DB: example_func (bug.c:37) ==16956== by 0x1090D3: main (bug.c:44) ==16956== Uninitialised value was created by a stack allocation ==16956== at 0x109280: example_func (bug.c:26) ==16956== ==16956== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0) When I run with --expensive-definedness-checks=yes, no problems are reported: $ valgrind --expensive-definedness-checks=yes ./bug ==16924== Memcheck, a memory error detector ==16924== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al. ==16924== Using Valgrind-3.15.0 and LibVEX; rerun with -h for copyright info ==16924== Command: ./bug ==16924== out = command = ==16924== ==16924== HEAP SUMMARY: ==16924== in use at exit: 0 bytes in 0 blocks ==16924== total heap usage: 1 allocs, 1 frees, 1,024 bytes allocated ==16924== ==16924== All heap blocks were freed -- no leaks are possible ==16924== ==16924== For lists of detected and suppressed errors, rerun with: -s ==16924== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
