204 lines · cpp
1// RUN: %clang_cc1 -fsyntax-only -Wunused-lambda-capture -Wused-but-marked-unused -Wno-uninitialized -verify -std=c++1z %s2 3class NonTrivialConstructor {4public:5 NonTrivialConstructor() {}6};7 8class NonTrivialCopyConstructor {9public:10 NonTrivialCopyConstructor() = default;11 NonTrivialCopyConstructor(const NonTrivialCopyConstructor &) {}12};13 14class NonTrivialDestructor {15public:16 ~NonTrivialDestructor() {}17};18 19class Trivial {20public:21 Trivial() = default;22 Trivial(int a) {}23};24 25int side_effect() {26 return 42;27}28 29void test() {30 int i = 0;31 const int k = 0;32 33 auto captures_nothing = [] {};34 35 auto captures_nothing_by_value = [=] {};36 auto captures_nothing_by_reference = [&] {};37 38 auto implicit_by_value = [=]() mutable { i++; };39 auto implicit_by_reference = [&] { i++; };40 41 auto explicit_by_value_used = [i] { return i + 1; };42 auto explicit_by_value_used_void = [i] { (void)i; };43 auto explicit_by_value_unused = [i] {}; // expected-warning{{lambda capture 'i' is not used}}44 auto explicit_by_value_unused_sizeof = [i] { return sizeof(i); }; // expected-warning{{lambda capture 'i' is not required to be captured for this use}}45 auto explicit_by_value_unused_decltype = [i] { decltype(i) j = 0; }; // expected-warning{{lambda capture 'i' is not required to be captured for this use}}46 auto explicit_by_value_unused_const = [k] { return k + 1; }; // expected-warning{{lambda capture 'k' is not required to be captured for this use}}47 48 auto explicit_by_reference_used = [&i] { i++; };49 auto explicit_by_reference_unused = [&i] {}; // expected-warning{{lambda capture 'i' is not used}}50 51 auto explicit_initialized_reference_used = [&j = i] { return j + 1; };52 auto explicit_initialized_reference_unused = [&j = i]{}; // expected-warning{{lambda capture 'j' is not used}}53 54 auto explicit_initialized_value_used = [j = 1] { return j + 1; };55 auto explicit_initialized_value_unused = [j = 1] {}; // expected-warning{{lambda capture 'j' is not used}}56 auto explicit_initialized_value_non_trivial_constructor = [j = NonTrivialConstructor()]{};57 auto explicit_initialized_value_non_trivial_destructor = [j = NonTrivialDestructor()]{};58 auto explicit_initialized_value_trivial_init = [j = Trivial()]{}; // expected-warning{{lambda capture 'j' is not used}}59 auto explicit_initialized_value_non_trivial_init = [j = Trivial(42)]{};60 auto explicit_initialized_value_with_side_effect = [j = side_effect()]{};61 62 auto nested = [&i] {63 auto explicit_by_value_used = [i] { return i + 1; };64 auto explicit_by_value_unused = [i] {}; // expected-warning{{lambda capture 'i' is not used}}65 };66 67 Trivial trivial;68 auto explicit_by_value_trivial = [trivial] {}; // expected-warning{{lambda capture 'trivial' is not used}}69 70 NonTrivialConstructor cons;71 auto explicit_by_value_non_trivial_constructor = [cons] {}; // expected-warning{{lambda capture 'cons' is not used}}72 73 NonTrivialCopyConstructor copy_cons;74 auto explicit_by_value_non_trivial_copy_constructor = [copy_cons] {};75 76 NonTrivialDestructor dest;77 auto explicit_by_value_non_trivial_destructor = [dest] {};78 79 volatile int v;80 auto explicit_by_value_volatile = [v] {};81}82 83class TrivialThis : Trivial {84 void test() {85 auto explicit_this_used = [this] { return i; };86 auto explicit_this_used_void = [this] { (void)this; };87 auto explicit_this_unused = [this] {}; // expected-warning{{lambda capture 'this' is not used}}88 auto explicit_star_this_used = [*this] { return i; };89 auto explicit_star_this_used_void = [*this] { (void)this; };90 auto explicit_star_this_unused = [*this] {}; // expected-warning{{lambda capture 'this' is not used}}91 }92 int i;93};94 95class NonTrivialConstructorThis : NonTrivialConstructor {96 void test() {97 auto explicit_this_used = [this] { return i; };98 auto explicit_this_used_void = [this] { (void)this; };99 auto explicit_this_unused = [this] {}; // expected-warning{{lambda capture 'this' is not used}}100 auto explicit_star_this_used = [*this] { return i; };101 auto explicit_star_this_used_void = [*this] { (void)this; };102 auto explicit_star_this_unused = [*this] {}; // expected-warning{{lambda capture 'this' is not used}}103 }104 int i;105};106 107class NonTrivialCopyConstructorThis : NonTrivialCopyConstructor {108 void test() {109 auto explicit_this_used = [this] { return i; };110 auto explicit_this_used_void = [this] { (void)this; };111 auto explicit_this_unused = [this] {}; // expected-warning{{lambda capture 'this' is not used}}112 auto explicit_star_this_used = [*this] { return i; };113 auto explicit_star_this_used_void = [*this] { (void)this; };114 auto explicit_star_this_unused = [*this] {};115 }116 int i;117};118 119class NonTrivialDestructorThis : NonTrivialDestructor {120 void test() {121 auto explicit_this_used = [this] { return i; };122 auto explicit_this_used_void = [this] { (void)this; };123 auto explicit_this_unused = [this] {}; // expected-warning{{lambda capture 'this' is not used}}124 auto explicit_star_this_used = [*this] { return i; };125 auto explicit_star_this_used_void = [*this] { (void)this; };126 auto explicit_star_this_unused = [*this] {};127 }128 int i;129};130 131template <typename T>132void test_templated() {133 int i = 0;134 const int k = 0;135 136 auto captures_nothing = [] {};137 138 auto captures_nothing_by_value = [=] {};139 auto captures_nothing_by_reference = [&] {};140 141 auto implicit_by_value = [=]() mutable { i++; };142 auto implicit_by_reference = [&] { i++; };143 144 auto explicit_by_value_used = [i] { return i + 1; };145 auto explicit_by_value_used_generic = [i](auto c) { return i + 1; };146 auto explicit_by_value_used_void = [i] { (void)i; };147 148 auto explicit_by_value_unused = [i] {}; // expected-warning{{lambda capture 'i' is not used}}149 auto explicit_by_value_unused_sizeof = [i] { return sizeof(i); }; // expected-warning{{lambda capture 'i' is not required to be captured for this use}}150 auto explicit_by_value_unused_decltype = [i] { decltype(i) j = 0; }; // expected-warning{{lambda capture 'i' is not used}}151 auto explicit_by_value_unused_const = [k] { return k + 1; }; // expected-warning{{lambda capture 'k' is not required to be captured for this use}}152 auto explicit_by_value_unused_const_generic = [k](auto c) { return k + 1; }; // expected-warning{{lambda capture 'k' is not required to be captured for this use}}153 154 auto explicit_by_reference_used = [&i] { i++; };155 auto explicit_by_reference_unused = [&i] {}; // expected-warning{{lambda capture 'i' is not used}}156 157 auto explicit_initialized_reference_used = [&j = i] { return j + 1; };158 auto explicit_initialized_reference_unused = [&j = i]{}; // expected-warning{{lambda capture 'j' is not used}}159 160 auto explicit_initialized_value_used = [j = 1] { return j + 1; };161 auto explicit_initialized_value_unused = [j = 1] {}; // expected-warning{{lambda capture 'j' is not used}}162 auto explicit_initialized_value_non_trivial_constructor = [j = NonTrivialConstructor()]{};163 auto explicit_initialized_value_non_trivial_destructor = [j = NonTrivialDestructor()]{};164 auto explicit_initialized_value_trivial_init = [j = Trivial()]{}; // expected-warning{{lambda capture 'j' is not used}}165 auto explicit_initialized_value_non_trivial_init = [j = Trivial(42)]{};166 auto explicit_initialized_value_with_side_effect = [j = side_effect()]{};167 auto explicit_initialized_value_generic_used = [i = 1](auto c) mutable { i++; };168 auto explicit_initialized_value_generic_unused = [i = 1](auto c) mutable {}; // expected-warning{{lambda capture 'i' is not used}}169 170 auto nested = [&i] { // expected-note {{substituting into a lambda}}171 auto explicit_by_value_used = [i] { return i + 1; };172 auto explicit_by_value_unused = [i] {}; // expected-warning{{lambda capture 'i' is not used}}173 };174 175 Trivial trivial;176 auto explicit_by_value_trivial = [trivial] {}; // expected-warning{{lambda capture 'trivial' is not used}}177 178 NonTrivialConstructor cons;179 auto explicit_by_value_non_trivial_constructor = [cons] {}; // expected-warning{{lambda capture 'cons' is not used}}180 181 NonTrivialCopyConstructor copy_cons;182 auto explicit_by_value_non_trivial_copy_constructor = [copy_cons] {};183 184 NonTrivialDestructor dest;185 auto explicit_by_value_non_trivial_destructor = [dest] {};186 187 volatile int v;188 auto explicit_by_value_volatile = [v] {};189}190 191void test_use_template() {192 test_templated<int>(); // expected-note 3 {{requested here}}193}194 195namespace pr35555 {196int a; // expected-note {{declared here}}197void b() {198 int c[a]; // expected-warning {{variable length arrays in C++ are a Clang extension}} \199 expected-note {{read of non-const variable 'a' is not allowed in a constant expression}}200 auto vla_used = [&c] { return c[0]; };201 auto vla_unused = [&c] {}; // expected-warning{{lambda capture 'c' is not used}}202}203} // namespace pr35555204