https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106101
--- Comment #29 from Andrew Pinski <pinskia at gcc dot gnu.org> --- (In reply to Florian Weimer from comment #28) > (In reply to Richard Biener from comment #1) > > Created attachment 53207 [details] > > reduced testcase > > Do you happen to have the unreduced test case still? > > int *yyvsp = 0; > > followed by: > > if (strncmp( yyvsp[0], "~", 1) == 0) { > > and > > free(yyvsp[0]); > > looks rather bogus. You can make `yyvsp` and argument if you are worried about the null pointer and you still get the crash back in 12.1.0. That is: ``` int yyparse (int *yyvsp) { int yystate = 0; ``` See https://godbolt.org/z/9YMsar1Ej .