Fix UB in format_arg_store implementation.

This commit is contained in:
Ivan Afanasyev 2024-01-31 22:21:56 +07:00
parent 71a4a8d479
commit b0945c2c9a

View File

@ -1636,7 +1636,9 @@ template <typename Context, size_t NUM_ARGS, size_t NUM_NAMED_ARGS,
struct format_arg_store {
// args_[0].named_args points to named_args to avoid bloating format_args.
// +1 to workaround a bug in gcc 7.5 that causes duplicated-branches warning.
arg_t<Context, NUM_ARGS> args[1 + (NUM_ARGS != 0 ? NUM_ARGS : +1)];
static constexpr size_t ARGS_ARR_SIZE = 1 + (NUM_ARGS != 0 ? NUM_ARGS : +1);
arg_t<Context, NUM_ARGS> args[ARGS_ARR_SIZE];
named_arg_info<typename Context::char_type> named_args[NUM_NAMED_ARGS];
template <typename... T>
@ -1649,6 +1651,17 @@ struct format_arg_store {
0,
(init_named_arg(named_args, arg_index, named_arg_index, values), 0)...};
}
format_arg_store(format_arg_store&& rhs) {
args[0] = {named_args, NUM_NAMED_ARGS};
for (size_t i = 1; i < ARGS_ARR_SIZE; ++i) args[i] = rhs.args[i];
for (size_t i = 0; i < NUM_NAMED_ARGS; ++i)
named_args[i] = rhs.named_args[i];
}
format_arg_store(const format_arg_store& rhs) = delete;
format_arg_store& operator=(const format_arg_store& rhs) = delete;
format_arg_store& operator=(format_arg_store&& rhs) = delete;
};
// A specialization of format_arg_store without named arguments.