https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92026
Martin Sebor <msebor at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |ASSIGNED Last reconfirmed| |2019-10-08 Component|testsuite |middle-end Assignee|unassigned at gcc dot gnu.org |msebor at gcc dot gnu.org Ever confirmed|0 |1 --- Comment #1 from Martin Sebor <msebor at gcc dot gnu.org> --- The code from the test case on line 159 in Wstringop-overflow-18.c: char a8[8], b4[4]; void f (void) { __builtin_strcpy (b4, "123"); char *d = a8 + 5; __builtin_memcpy (d, b4, 4); } is represented like this on the failing sparc-sun-solaris2.11 (same on mips64el-linux): <bb 2> [local count: 1073741824]: MEM <unsigned char[4]> [(char * {ref-all})&b4] = MEM <unsigned char[4]> [(char * {ref-all})"123"]; MEM <unsigned char[4]> [(char * {ref-all})&a8 + 5B] = MEM <unsigned char[4]> [(char * {ref-all})&b4]; return; but like this on the passing arm-none-eabi: <bb 2> [local count: 1073741824]: MEM <unsigned char[4]> [(char * {ref-all})&b4] = "123"; MEM <unsigned char[4]> [(char * {ref-all})&a8 + 5B] = "123"; return; and like this on the passing x86_64: <bb 2> [local count: 1073741824]: MEM <unsigned char[4]> [(char * {ref-all})&b4] = MEM <unsigned char[4]> [(char * {ref-all})"123"]; MEM <unsigned int> [(char * {ref-all})&a8 + 5B] = 3355185; return; The warning knows how to handle all three forms but it doesn't know handle the first case correctly: it doesn't set the size of the store in the failing case.