Gcc-10 doesn't like the use of zero-length arrays as last struct member to denote variable sized objects. The suggested alternative, namely to use a flexible array member as defined by C99, is problematic as that doesn't allow for said struct to be embedded into others. With the relevant structs being part of kernel UAPI, this can't be precluded though. The call to memcpy() which triggers the warning copies data from one struct xt_counters to another. Since this struct is flat and merely contains two u64 fields, One can use direct assignment instead which avoids the warning. Signed-off-by: Phil Sutter <phil@xxxxxx> --- libiptc/libiptc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/libiptc/libiptc.c b/libiptc/libiptc.c index 5888201525213..ceeb017b39400 100644 --- a/libiptc/libiptc.c +++ b/libiptc/libiptc.c @@ -1169,7 +1169,7 @@ static int iptcc_compile_chain(struct xtc_handle *h, STRUCT_REPLACE *repl, struc else foot->target.verdict = RETURN; /* set policy-counters */ - memcpy(&foot->e.counters, &c->counters, sizeof(STRUCT_COUNTERS)); + foot->e.counters = c->counters; return 0; } -- 2.28.0