https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87387
--- Comment #1 from David Binderman <dcb314 at hotmail dot com> --- I found this bug by compiling gcc with the new clang 7.0 It seems that gcc can't be encouraged to warn about self-assignment. For example: $cat sep23a.cc // -Wself-assign. clang has it. gcc doesn't. extern void g( int); void f(int n) { int m = 2 * n; m = m; g( m); } $ ~/gcc/results/bin/gcc -c -O2 -Wall -Wextra sep23a.cc $ Given that this warning finds bugs in gcc itself, would this -Wself-assign warning be worth implementing in gcc ? I'll have a go at compiling the rest of the world with clang-7.0 and see what it finds.