https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81109
Bug ID: 81109
Summary: [8 Regression] new -Wclass-memaccess warning noisy
Product: gcc
Version: 8.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: trippels at gcc dot gnu.org
CC: msebor at gcc dot gnu.org
Target Milestone: ---
The new -Wclass-memaccess warning (r249234) is noisy, e.g.:
% cat deoptimizer-ppc.ii
class A {
A();
};
struct B {
struct C {
A a;
};
C cache_[1];
void Flush() { __builtin_memset(&cache_[0], 0, sizeof(cache_)); }
};
% g++ -Wall -c deoptimizer-ppc.ii
deoptimizer-ppc.ii: In member function ‘void B::Flush()’:
deoptimizer-ppc.ii:9:64: warning: ‘void* __builtin_memset(void*, int, long
unsigned int)’ clearing an object of non-trivial type ‘struct B::C’; use
assignment instead [-Wclass-memaccess]
void Flush() { __builtin_memset(&cache_[0], 0, sizeof(cache_)); }
^
deoptimizer-ppc.ii:5:10: note: ‘struct B::C’ declared here
struct C {
^
Build any non-trivial C++ project (like LLVM) and you will drown in warnings.
Not sure what to do, perhaps moving the warning to -Wextra?
