https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84383
Bug ID: 84383
Summary: [8 Regression] ICE in maybe_diag_stxncpy_trunc
Product: gcc
Version: 8.0
Status: UNCONFIRMED
Keywords: ice-on-valid-code
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: jakub at gcc dot gnu.org
Reporter: jakub at gcc dot gnu.org
Target Milestone: ---
int a;
struct S { char *s; };
void bar (struct S *);
void
foo (char *b)
{
struct S c[4];
bar (c);
__builtin_strncpy (c[a].s, b, 32);
c[a].s[31] = '\0';
}
ICEs at -O2 or fails under valgrind, like:
==32746== Conditional jump or move depends on uninitialised value(s)
==32746== at 0x1234997: maybe_diag_stxncpy_trunc(gimple_stmt_iterator,
tree_node*, tree_node*) (tree-ssa-strlen.c:1881)
==32746== by 0x1235595: handle_builtin_stxncpy(built_in_function,
gimple_stmt_iterator*) (tree-ssa-strlen.c:2079)
==32746== by 0x1238BEE:
strlen_check_and_optimize_stmt(gimple_stmt_iterator*, bool*)
(tree-ssa-strlen.c:3142)
==32746== by 0x123A225:
strlen_dom_walker::before_dom_children(basic_block_def*)
(tree-ssa-strlen.c:3475)
depending on what uninitialized value dstoff has.
