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Merged
merged 1 commit into from
Jul 19, 2025
Merged

[libc++] Diagnose passing null pointers to a bunch of APIs #148585

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1 change: 1 addition & 0 deletions libcxx/.clang-format
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Original file line number Diff line number Diff line change
Expand Up @@ -33,6 +33,7 @@ AttributeMacros: [
'_LIBCPP_DEPRECATED_IN_CXX20',
'_LIBCPP_DEPRECATED_IN_CXX23',
'_LIBCPP_DEPRECATED',
'_LIBCPP_DIAGNOSE_NULLPTR_IF',
'_LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION',
'_LIBCPP_EXPORTED_FROM_ABI',
'_LIBCPP_EXTERN_TEMPLATE_TYPE_VIS',
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14 changes: 14 additions & 0 deletions libcxx/include/__config
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Expand Up @@ -1090,6 +1090,20 @@ typedef __char32_t char32_t;
# define _LIBCPP_DIAGNOSE_WARNING(...)
# endif

# if __has_attribute(__diagnose_if__) && !defined(_LIBCPP_APPLE_CLANG_VER) && \
(!defined(_LIBCPP_CLANG_VER) || _LIBCPP_CLANG_VER >= 2001)
# define _LIBCPP_DIAGNOSE_IF(...) __attribute__((__diagnose_if__(__VA_ARGS__)))
# else
# define _LIBCPP_DIAGNOSE_IF(...)
# endif

# define _LIBCPP_DIAGNOSE_NULLPTR_IF(condition, condition_description) \
_LIBCPP_DIAGNOSE_IF( \
condition, \
"null passed to callee that requires a non-null argument" condition_description, \
"warning", \
"nonnull")

# if __has_cpp_attribute(_Clang::__lifetimebound__)
# define _LIBCPP_LIFETIMEBOUND [[_Clang::__lifetimebound__]]
# else
Expand Down
6 changes: 3 additions & 3 deletions libcxx/include/__memory/construct_at.h
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Expand Up @@ -33,7 +33,7 @@ _LIBCPP_BEGIN_NAMESPACE_STD
#if _LIBCPP_STD_VER >= 20

template <class _Tp, class... _Args, class = decltype(::new(std::declval<void*>()) _Tp(std::declval<_Args>()...))>
_LIBCPP_HIDE_FROM_ABI constexpr _Tp* construct_at(_Tp* __location, _Args&&... __args) {
_LIBCPP_HIDE_FROM_ABI constexpr _Tp* construct_at(_Tp* _LIBCPP_DIAGNOSE_NULLPTR __location, _Args&&... __args) {
_LIBCPP_ASSERT_NON_NULL(__location != nullptr, "null pointer given to construct_at");
return ::new (static_cast<void*>(__location)) _Tp(std::forward<_Args>(__args)...);
}
Expand Down Expand Up @@ -73,13 +73,13 @@ _LIBCPP_HIDE_FROM_ABI constexpr void __destroy_at(_Tp* __loc) {
#if _LIBCPP_STD_VER >= 17

template <class _Tp, enable_if_t<!is_array_v<_Tp>, int> = 0>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void destroy_at(_Tp* __loc) {
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void destroy_at(_Tp* _LIBCPP_DIAGNOSE_NULLPTR __loc) {
std::__destroy_at(__loc);
}

# if _LIBCPP_STD_VER >= 20
template <class _Tp, enable_if_t<is_array_v<_Tp>, int> = 0>
_LIBCPP_HIDE_FROM_ABI constexpr void destroy_at(_Tp* __loc) {
_LIBCPP_HIDE_FROM_ABI constexpr void destroy_at(_Tp* _LIBCPP_DIAGNOSE_NULLPTR __loc) {
std::__destroy_at(__loc);
}
# endif
Expand Down
14 changes: 9 additions & 5 deletions libcxx/include/print
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Expand Up @@ -329,7 +329,8 @@ __vprint_unicode([[maybe_unused]] FILE* __stream,
} // namespace __print

template <class... _Args>
_LIBCPP_HIDE_FROM_ABI void print(FILE* __stream, format_string<_Args...> __fmt, _Args&&... __args) {
_LIBCPP_HIDE_FROM_ABI void
print(FILE* _LIBCPP_DIAGNOSE_NULLPTR __stream, format_string<_Args...> __fmt, _Args&&... __args) {
# if _LIBCPP_HAS_UNICODE
if constexpr (__print::__use_unicode_execution_charset)
__print::__vprint_unicode(__stream, __fmt.get(), std::make_format_args(__args...), false);
Expand All @@ -346,7 +347,8 @@ _LIBCPP_HIDE_FROM_ABI void print(format_string<_Args...> __fmt, _Args&&... __arg
}

template <class... _Args>
_LIBCPP_HIDE_FROM_ABI void println(FILE* __stream, format_string<_Args...> __fmt, _Args&&... __args) {
_LIBCPP_HIDE_FROM_ABI void
println(FILE* _LIBCPP_DIAGNOSE_NULLPTR __stream, format_string<_Args...> __fmt, _Args&&... __args) {
# if _LIBCPP_HAS_UNICODE
// Note the wording in the Standard is inefficient. The output of
// std::format is a std::string which is then copied. This solution
Expand All @@ -361,7 +363,7 @@ _LIBCPP_HIDE_FROM_ABI void println(FILE* __stream, format_string<_Args...> __fmt
}

template <class = void> // TODO PRINT template or availability markup fires too eagerly (http://llvm.org/PR61563).
_LIBCPP_HIDE_FROM_ABI inline void println(FILE* __stream) {
_LIBCPP_HIDE_FROM_ABI inline void println(FILE* _LIBCPP_DIAGNOSE_NULLPTR __stream) {
std::print(__stream, "\n");
}

Expand All @@ -377,7 +379,8 @@ _LIBCPP_HIDE_FROM_ABI void println(format_string<_Args...> __fmt, _Args&&... __a

# if _LIBCPP_HAS_UNICODE
template <class = void> // TODO PRINT template or availability markup fires too eagerly (http://llvm.org/PR61563).
_LIBCPP_HIDE_FROM_ABI inline void vprint_unicode(FILE* __stream, string_view __fmt, format_args __args) {
_LIBCPP_HIDE_FROM_ABI inline void
vprint_unicode(FILE* _LIBCPP_DIAGNOSE_NULLPTR __stream, string_view __fmt, format_args __args) {
__print::__vprint_unicode(__stream, __fmt, __args, false);
}

Expand All @@ -389,7 +392,8 @@ _LIBCPP_HIDE_FROM_ABI inline void vprint_unicode(string_view __fmt, format_args
# endif // _LIBCPP_HAS_UNICODE

template <class = void> // TODO PRINT template or availability markup fires too eagerly (http://llvm.org/PR61563).
_LIBCPP_HIDE_FROM_ABI inline void vprint_nonunicode(FILE* __stream, string_view __fmt, format_args __args) {
_LIBCPP_HIDE_FROM_ABI inline void
vprint_nonunicode(FILE* _LIBCPP_DIAGNOSE_NULLPTR __stream, string_view __fmt, format_args __args) {
__print::__vprint_nonunicode(__stream, __fmt, __args, false);
}

Expand Down
45 changes: 30 additions & 15 deletions libcxx/include/string
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Original file line number Diff line number Diff line change
Expand Up @@ -1065,13 +1065,15 @@ public:
basic_string(nullptr_t) = delete;
# endif

_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string(const _CharT* __s, size_type __n) {
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string(const _CharT* __s, size_type __n)
_LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero") {
_LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "basic_string(const char*, n) detected nullptr");
__init(__s, __n);
}

_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
basic_string(const _CharT* __s, size_type __n, const _Allocator& __a)
_LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero")
: __alloc_(__a) {
_LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "basic_string(const char*, n, allocator) detected nullptr");
__init(__s, __n);
Expand Down Expand Up @@ -1394,7 +1396,8 @@ public:
return append(__sv.data() + __pos, std::min(__n, __sz - __pos));
}

_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& append(const value_type* __s, size_type __n);
_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& append(const value_type* __s, size_type __n)
_LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero");
_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& append(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s);
_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& append(size_type __n, value_type __c);

Expand Down Expand Up @@ -1521,8 +1524,9 @@ public:
return assign(__sv.data() + __pos, std::min(__n, __sz - __pos));
}

_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& assign(const value_type* __s, size_type __n);
_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& assign(const value_type* __s);
_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& assign(const value_type* __s, size_type __n)
_LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero");
_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& assign(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s);
_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& assign(size_type __n, value_type __c);

template <class _InputIterator, __enable_if_t<__has_exactly_input_iterator_category<_InputIterator>::value, int> = 0>
Expand Down Expand Up @@ -1593,7 +1597,8 @@ public:

_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
insert(size_type __pos1, const basic_string& __str, size_type __pos2, size_type __n = npos);
_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& insert(size_type __pos, const value_type* __s, size_type __n);
_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& insert(size_type __pos, const value_type* __s, size_type __n)
_LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero");
_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& insert(size_type __pos, const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s);
_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& insert(size_type __pos, size_type __n, value_type __c);
_LIBCPP_CONSTEXPR_SINCE_CXX20 iterator insert(const_iterator __pos, value_type __c);
Expand Down Expand Up @@ -1673,8 +1678,10 @@ public:
}

_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
replace(size_type __pos, size_type __n1, const value_type* __s, size_type __n2);
_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& replace(size_type __pos, size_type __n1, const value_type* __s);
replace(size_type __pos, size_type __n1, const value_type* __s, size_type __n2)
_LIBCPP_DIAGNOSE_NULLPTR_IF(__n2 != 0 && __s == nullptr, " if n2 is not zero");
_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
replace(size_type __pos, size_type __n1, const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s);
_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& replace(size_type __pos, size_type __n1, size_type __n2, value_type __c);

_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
Expand Down Expand Up @@ -1783,7 +1790,8 @@ public:
return std::__str_find<value_type, size_type, traits_type, npos>(data(), size(), __sv.data(), __pos, __sv.size());
}

_LIBCPP_CONSTEXPR_SINCE_CXX20 size_type find(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT {
_LIBCPP_CONSTEXPR_SINCE_CXX20 size_type find(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT
_LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero") {
_LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "string::find(): received nullptr");
return std::__str_find<value_type, size_type, traits_type, npos>(data(), size(), __s, __pos, __n);
}
Expand Down Expand Up @@ -1814,7 +1822,8 @@ public:
return std::__str_rfind<value_type, size_type, traits_type, npos>(data(), size(), __sv.data(), __pos, __sv.size());
}

_LIBCPP_CONSTEXPR_SINCE_CXX20 size_type rfind(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT {
_LIBCPP_CONSTEXPR_SINCE_CXX20 size_type rfind(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT
_LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero") {
_LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "string::rfind(): received nullptr");
return std::__str_rfind<value_type, size_type, traits_type, npos>(data(), size(), __s, __pos, __n);
}
Expand Down Expand Up @@ -1847,7 +1856,8 @@ public:
}

_LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
find_first_of(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT {
find_first_of(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT
_LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero") {
_LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "string::find_first_of(): received nullptr");
return std::__str_find_first_of<value_type, size_type, traits_type, npos>(data(), size(), __s, __pos, __n);
}
Expand Down Expand Up @@ -1881,7 +1891,8 @@ public:
}

_LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
find_last_of(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT {
find_last_of(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT
_LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero") {
_LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "string::find_last_of(): received nullptr");
return std::__str_find_last_of<value_type, size_type, traits_type, npos>(data(), size(), __s, __pos, __n);
}
Expand Down Expand Up @@ -1915,7 +1926,8 @@ public:
}

_LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
find_first_not_of(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT {
find_first_not_of(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT
_LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero") {
_LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "string::find_first_not_of(): received nullptr");
return std::__str_find_first_not_of<value_type, size_type, traits_type, npos>(data(), size(), __s, __pos, __n);
}
Expand Down Expand Up @@ -1949,7 +1961,8 @@ public:
}

_LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
find_last_not_of(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT {
find_last_not_of(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT
_LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero") {
_LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "string::find_last_not_of(): received nullptr");
return std::__str_find_last_not_of<value_type, size_type, traits_type, npos>(data(), size(), __s, __pos, __n);
}
Expand Down Expand Up @@ -2026,7 +2039,8 @@ public:
}

_LIBCPP_CONSTEXPR_SINCE_CXX20 int
compare(size_type __pos1, size_type __n1, const value_type* __s, size_type __n2) const;
compare(size_type __pos1, size_type __n1, const value_type* __s, size_type __n2) const
_LIBCPP_DIAGNOSE_NULLPTR_IF(__n2 != 0 && __s == nullptr, " if n2 is not zero");

// starts_with

Expand Down Expand Up @@ -3564,7 +3578,8 @@ operator==(const basic_string<_CharT, _Traits, _Allocator>& __lhs,

template <class _CharT, class _Traits, class _Allocator>
inline _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI bool
operator==(const basic_string<_CharT, _Traits, _Allocator>& __lhs, const _CharT* __rhs) _NOEXCEPT {
operator==(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
const _CharT* _LIBCPP_DIAGNOSE_NULLPTR __rhs) _NOEXCEPT {
_LIBCPP_ASSERT_NON_NULL(__rhs != nullptr, "operator==(basic_string, char*): received nullptr");

using _String = basic_string<_CharT, _Traits, _Allocator>;
Expand Down
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