launder aligned_storage pointers

master
Daniel Kolesa 2021-03-24 02:42:33 +01:00
parent d774db675a
commit 4ded59ce70
3 changed files with 64 additions and 54 deletions

View File

@ -11,6 +11,7 @@
#include <memory> #include <memory>
#include <utility> #include <utility>
#include <span> #include <span>
#include <new>
#include "cubescript_conf.hh" #include "cubescript_conf.hh"
@ -68,9 +69,9 @@ private:
} }
virtual R operator()(A &&...args) { virtual R operator()(A &&...args) {
return std::invoke( return std::invoke(*std::launder(
*reinterpret_cast<F *>(&p_stor), std::forward<A>(args)... reinterpret_cast<F *>(&p_stor)
); ), std::forward<A>(args)...);
} }
private: private:
@ -114,7 +115,7 @@ private:
} }
p_func->~base(); p_func->~base();
if (!small_storage()) { if (!small_storage()) {
auto &ad = *reinterpret_cast<f_alloc *>(&p_stor); auto &ad = *std::launder(reinterpret_cast<f_alloc *>(&p_stor));
ad.af(ad.ud, p_func, ad.asize, 0); ad.af(ad.ud, p_func, ad.asize, 0);
} }
} }
@ -145,7 +146,7 @@ public:
auto *p = static_cast<void *>(&p_stor); auto *p = static_cast<void *>(&p_stor);
p_func = ::new (p) store<F>{std::move(func)}; p_func = ::new (p) store<F>{std::move(func)};
} else { } else {
auto &ad = *reinterpret_cast<f_alloc *>(&p_stor); auto &ad = *std::launder(reinterpret_cast<f_alloc *>(&p_stor));
ad.af = af; ad.af = af;
ad.ud = ud; ad.ud = ud;
ad.asize = sizeof(store<F>); ad.asize = sizeof(store<F>);
@ -383,7 +384,9 @@ private:
}; };
internal_state *get_state() const { internal_state *get_state() const {
return reinterpret_cast<stor_t<void *> const *>(&p_stor)->state; return std::launder(
reinterpret_cast<stor_t<void *> const *>(&p_stor)
)->state;
} }
std::aligned_union_t<1, std::aligned_union_t<1,

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@ -4,6 +4,7 @@
#include <cubescript/cubescript.hh> #include <cubescript/cubescript.hh>
#include <cstddef> #include <cstddef>
#include <new>
#include <utility> #include <utility>
#include <type_traits> #include <type_traits>
#include <string_view> #include <string_view>
@ -43,12 +44,12 @@ struct valarray {
~valarray() { ~valarray() {
for (std::size_t i = 0; i < N; ++i) { for (std::size_t i = 0; i < N; ++i) {
reinterpret_cast<T *>(&stor[i])->~T(); std::launder(reinterpret_cast<T *>(&stor[i]))->~T();
} }
} }
T &operator[](std::size_t i) { T &operator[](std::size_t i) {
return *reinterpret_cast<T *>(&stor[i]); return *std::launder(reinterpret_cast<T *>(&stor[i]));
} }
std::aligned_storage_t<sizeof(T), alignof(T)> stor[N]; std::aligned_storage_t<sizeof(T), alignof(T)> stor[N];

View File

@ -60,16 +60,18 @@ struct stor_priv_t {
}; };
template<typename T, typename U> template<typename T, typename U>
static inline T &csv_get(U &stor) { static inline T &csv_get(U *stor) {
/* ugly, but internal and unlikely to cause bugs */ /* ugly, but internal and unlikely to cause bugs */
return const_cast<T &>(reinterpret_cast<stor_priv_t<T> const &>(stor).val); return const_cast<T &>(std::launder(
reinterpret_cast<stor_priv_t<T> const *>(stor)
)->val);
} }
template<typename T> template<typename T>
static inline void csv_cleanup(value_type tv, T &stor) { static inline void csv_cleanup(value_type tv, T *stor) {
switch (tv) { switch (tv) {
case value_type::STRING: case value_type::STRING:
reinterpret_cast<string_ref *>(&stor)->~string_ref(); std::launder(reinterpret_cast<string_ref *>(stor))->~string_ref();
break; break;
case value_type::CODE: { case value_type::CODE: {
bcode_unref(csv_get<uint32_t *>(stor)); bcode_unref(csv_get<uint32_t *>(stor));
@ -85,11 +87,11 @@ any_value::any_value(state &st): any_value(*st.p_state) {}
any_value::any_value(internal_state &st): any_value::any_value(internal_state &st):
p_stor(), p_type(value_type::NONE) p_stor(), p_type(value_type::NONE)
{ {
reinterpret_cast<stor_priv_t<void *> *>(&p_stor)->state = &st; std::launder(reinterpret_cast<stor_priv_t<void *> *>(&p_stor))->state = &st;
} }
any_value::~any_value() { any_value::~any_value() {
csv_cleanup(p_type, p_stor); csv_cleanup(p_type, &p_stor);
} }
any_value::any_value(any_value const &v): any_value(*v.get_state()) { any_value::any_value(any_value const &v): any_value(*v.get_state()) {
@ -101,7 +103,7 @@ any_value::any_value(any_value &&v): any_value(*v.get_state()) {
} }
any_value &any_value::operator=(any_value const &v) { any_value &any_value::operator=(any_value const &v) {
csv_cleanup(p_type, p_stor); csv_cleanup(p_type, &p_stor);
p_type = value_type::NONE; p_type = value_type::NONE;
switch (v.get_type()) { switch (v.get_type()) {
case value_type::INT: case value_type::INT:
@ -113,7 +115,7 @@ any_value &any_value::operator=(any_value const &v) {
case value_type::STRING: case value_type::STRING:
p_type = value_type::STRING; p_type = value_type::STRING;
new (&p_stor) string_ref{ new (&p_stor) string_ref{
*reinterpret_cast<string_ref const *>(&v.p_stor) *std::launder(reinterpret_cast<string_ref const *>(&v.p_stor))
}; };
break; break;
case value_type::CODE: case value_type::CODE:
@ -136,45 +138,45 @@ value_type any_value::get_type() const {
} }
void any_value::set_int(integer_type val) { void any_value::set_int(integer_type val) {
csv_cleanup(p_type, p_stor); csv_cleanup(p_type, &p_stor);
p_type = value_type::INT; p_type = value_type::INT;
csv_get<integer_type>(p_stor) = val; csv_get<integer_type>(&p_stor) = val;
} }
void any_value::set_float(float_type val) { void any_value::set_float(float_type val) {
csv_cleanup(p_type, p_stor); csv_cleanup(p_type, &p_stor);
p_type = value_type::FLOAT; p_type = value_type::FLOAT;
csv_get<float_type>(p_stor) = val; csv_get<float_type>(&p_stor) = val;
} }
void any_value::set_str(std::string_view val) { void any_value::set_str(std::string_view val) {
csv_cleanup(p_type, p_stor); csv_cleanup(p_type, &p_stor);
new (&p_stor) string_ref{get_state(), val}; new (&p_stor) string_ref{get_state(), val};
p_type = value_type::STRING; p_type = value_type::STRING;
} }
void any_value::set_str(string_ref const &val) { void any_value::set_str(string_ref const &val) {
csv_cleanup(p_type, p_stor); csv_cleanup(p_type, &p_stor);
new (&p_stor) string_ref{val}; new (&p_stor) string_ref{val};
p_type = value_type::STRING; p_type = value_type::STRING;
} }
void any_value::set_none() { void any_value::set_none() {
csv_cleanup(p_type, p_stor); csv_cleanup(p_type, &p_stor);
p_type = value_type::NONE; p_type = value_type::NONE;
} }
void any_value::set_code(bcode *val) { void any_value::set_code(bcode *val) {
csv_cleanup(p_type, p_stor); csv_cleanup(p_type, &p_stor);
p_type = value_type::CODE; p_type = value_type::CODE;
bcode_addref(val->get_raw()); bcode_addref(val->get_raw());
csv_get<bcode *>(p_stor) = val; csv_get<bcode *>(&p_stor) = val;
} }
void any_value::set_ident(ident *val) { void any_value::set_ident(ident *val) {
csv_cleanup(p_type, p_stor); csv_cleanup(p_type, &p_stor);
p_type = value_type::IDENT; p_type = value_type::IDENT;
csv_get<ident *>(p_stor) = val; csv_get<ident *>(&p_stor) = val;
} }
void any_value::force_none() { void any_value::force_none() {
@ -188,15 +190,15 @@ float_type any_value::force_float() {
float_type rf = 0.0f; float_type rf = 0.0f;
switch (get_type()) { switch (get_type()) {
case value_type::INT: case value_type::INT:
rf = csv_get<integer_type>(p_stor); rf = csv_get<integer_type>(&p_stor);
break; break;
case value_type::STRING: case value_type::STRING:
rf = parse_float( rf = parse_float(
*reinterpret_cast<string_ref const *>(&p_stor) *std::launder(reinterpret_cast<string_ref const *>(&p_stor))
); );
break; break;
case value_type::FLOAT: case value_type::FLOAT:
return csv_get<float_type>(p_stor); return csv_get<float_type>(&p_stor);
default: default:
break; break;
} }
@ -208,15 +210,15 @@ integer_type any_value::force_int() {
integer_type ri = 0; integer_type ri = 0;
switch (get_type()) { switch (get_type()) {
case value_type::FLOAT: case value_type::FLOAT:
ri = csv_get<float_type>(p_stor); ri = csv_get<float_type>(&p_stor);
break; break;
case value_type::STRING: case value_type::STRING:
ri = parse_int( ri = parse_int(
*reinterpret_cast<string_ref const *>(&p_stor) *std::launder(reinterpret_cast<string_ref const *>(&p_stor))
); );
break; break;
case value_type::INT: case value_type::INT:
return csv_get<integer_type>(p_stor); return csv_get<integer_type>(&p_stor);
default: default:
break; break;
} }
@ -229,30 +231,32 @@ std::string_view any_value::force_str() {
std::string_view str; std::string_view str;
switch (get_type()) { switch (get_type()) {
case value_type::FLOAT: case value_type::FLOAT:
str = floatstr(csv_get<float_type>(p_stor), rs); str = floatstr(csv_get<float_type>(&p_stor), rs);
break; break;
case value_type::INT: case value_type::INT:
str = intstr(csv_get<integer_type>(p_stor), rs); str = intstr(csv_get<integer_type>(&p_stor), rs);
break; break;
case value_type::STRING: case value_type::STRING:
return *reinterpret_cast<string_ref const *>(&p_stor); return *std::launder(reinterpret_cast<string_ref const *>(&p_stor));
default: default:
str = rs.str(); str = rs.str();
break; break;
} }
set_str(str); set_str(str);
return std::string_view(*reinterpret_cast<string_ref const *>(&p_stor)); return std::string_view(*std::launder(
reinterpret_cast<string_ref const *>(&p_stor)
));
} }
integer_type any_value::get_int() const { integer_type any_value::get_int() const {
switch (get_type()) { switch (get_type()) {
case value_type::FLOAT: case value_type::FLOAT:
return integer_type(csv_get<float_type>(p_stor)); return integer_type(csv_get<float_type>(&p_stor));
case value_type::INT: case value_type::INT:
return csv_get<integer_type>(p_stor); return csv_get<integer_type>(&p_stor);
case value_type::STRING: case value_type::STRING:
return parse_int( return parse_int(
*reinterpret_cast<string_ref const *>(&p_stor) *std::launder(reinterpret_cast<string_ref const *>(&p_stor))
); );
default: default:
break; break;
@ -263,12 +267,12 @@ integer_type any_value::get_int() const {
float_type any_value::get_float() const { float_type any_value::get_float() const {
switch (get_type()) { switch (get_type()) {
case value_type::FLOAT: case value_type::FLOAT:
return csv_get<float_type>(p_stor); return csv_get<float_type>(&p_stor);
case value_type::INT: case value_type::INT:
return float_type(csv_get<integer_type>(p_stor)); return float_type(csv_get<integer_type>(&p_stor));
case value_type::STRING: case value_type::STRING:
return parse_float( return parse_float(
*reinterpret_cast<string_ref const *>(&p_stor) *std::launder(reinterpret_cast<string_ref const *>(&p_stor))
); );
default: default:
break; break;
@ -280,30 +284,30 @@ bcode *any_value::get_code() const {
if (get_type() != value_type::CODE) { if (get_type() != value_type::CODE) {
return nullptr; return nullptr;
} }
return csv_get<bcode *>(p_stor); return csv_get<bcode *>(&p_stor);
} }
ident *any_value::get_ident() const { ident *any_value::get_ident() const {
if (get_type() != value_type::IDENT) { if (get_type() != value_type::IDENT) {
return nullptr; return nullptr;
} }
return csv_get<ident *>(p_stor); return csv_get<ident *>(&p_stor);
} }
string_ref any_value::get_str() const { string_ref any_value::get_str() const {
switch (get_type()) { switch (get_type()) {
case value_type::STRING: case value_type::STRING:
return *reinterpret_cast<string_ref const *>(&p_stor); return *std::launder(reinterpret_cast<string_ref const *>(&p_stor));
case value_type::INT: { case value_type::INT: {
charbuf rs{get_state()}; charbuf rs{get_state()};
return string_ref{ return string_ref{
get_state(), intstr(csv_get<integer_type>(p_stor), rs) get_state(), intstr(csv_get<integer_type>(&p_stor), rs)
}; };
} }
case value_type::FLOAT: { case value_type::FLOAT: {
charbuf rs{get_state()}; charbuf rs{get_state()};
return string_ref{ return string_ref{
get_state(), floatstr(csv_get<float_type>(p_stor), rs) get_state(), floatstr(csv_get<float_type>(&p_stor), rs)
}; };
} }
default: default:
@ -318,10 +322,10 @@ void any_value::get_val(any_value &r) const {
r = *this; r = *this;
break; break;
case value_type::INT: case value_type::INT:
r.set_int(csv_get<integer_type>(p_stor)); r.set_int(csv_get<integer_type>(&p_stor));
break; break;
case value_type::FLOAT: case value_type::FLOAT:
r.set_float(csv_get<float_type>(p_stor)); r.set_float(csv_get<float_type>(&p_stor));
break; break;
default: default:
r.set_none(); r.set_none();
@ -340,17 +344,19 @@ bool any_value::code_is_empty() const {
if (get_type() != value_type::CODE) { if (get_type() != value_type::CODE) {
return true; return true;
} }
return cubescript::code_is_empty(csv_get<bcode *>(p_stor)); return cubescript::code_is_empty(csv_get<bcode *>(&p_stor));
} }
bool any_value::get_bool() const { bool any_value::get_bool() const {
switch (get_type()) { switch (get_type()) {
case value_type::FLOAT: case value_type::FLOAT:
return csv_get<float_type>(p_stor) != 0; return csv_get<float_type>(&p_stor) != 0;
case value_type::INT: case value_type::INT:
return csv_get<integer_type>(p_stor) != 0; return csv_get<integer_type>(&p_stor) != 0;
case value_type::STRING: { case value_type::STRING: {
std::string_view s = *reinterpret_cast<string_ref const *>(&p_stor); std::string_view s = *std::launder(
reinterpret_cast<string_ref const *>(&p_stor)
);
if (s.empty()) { if (s.empty()) {
return false; return false;
} }