161 lines · cpp
1// RUN: %clang_cc1 -fsyntax-only -verify -std=c++98 -pedantic %s2// C++ [expr.const]p1:3// In several places, C++ requires expressions that evaluate to an integral4// or enumeration constant: as array bounds, as case expressions, as5// bit-field lengths, as enumerator initializers, as static member6// initializers, and as integral or enumeration non-type template arguments.7// An integral constant-expression can involve only literals, enumerators,8// const variables or static data members of integral or enumeration types9// initialized with constant expressions, and sizeof expressions. Floating10// literals can appear only if they are cast to integral or enumeration types.11 12enum Enum { eval = 1 };13const int cval = 2;14const Enum ceval = eval;15struct Struct {16 static const int sval = 3;17 static const Enum seval = eval;18};19 20template <int itval, Enum etval> struct C {21 enum E {22 v1 = 1,23 v2 = eval,24 v3 = cval,25 v4 = ceval,26 v5 = Struct::sval,27 v6 = Struct::seval,28 v7 = itval,29 v8 = etval,30 v9 = (int)1.5,31 v10 = sizeof(Struct),32 v11 = true? 1 + cval * Struct::sval ^ itval / (int)1.5 - sizeof(Struct) : 033 };34 unsigned35 b1 : 1,36 b2 : eval,37 b3 : cval,38 b4 : ceval,39 b5 : Struct::sval,40 b6 : Struct::seval,41 b7 : itval,42 b8 : etval,43 b9 : (int)1.5,44 b10 : sizeof(Struct),45 b11 : true? 1 + cval * Struct::sval ^ itval / (int)1.5 - sizeof(Struct) : 046 ;47 static const int48 i1 = 1,49 i2 = eval,50 i3 = cval,51 i4 = ceval,52 i5 = Struct::sval,53 i6 = Struct::seval,54 i7 = itval,55 i8 = etval,56 i9 = (int)1.5,57 i10 = sizeof(Struct),58 i11 = true? 1 + cval * Struct::sval ^ itval / (int)1.5 - sizeof(Struct) : 059 ;60 void f(int cond) {61 switch(cond) {62 case 0 + 1:63 case 100 + eval:64 case 200 + cval:65 case 300 + ceval:66 case 400 + Struct::sval:67 case 500 + Struct::seval:68 case 600 + itval:69 case 700 + etval:70 case 800 + (int)1.5:71 case 900 + sizeof(Struct):72 case 1000 + (true? 1 + cval * Struct::sval ^73 itval / (int)1.5 - sizeof(Struct) : 0):74 ;75 }76 }77 typedef C<itval, etval> T0;78};79 80template struct C<1, eval>;81template struct C<cval, ceval>;82template struct C<Struct::sval, Struct::seval>;83 84enum {85 a = sizeof(int) == 8,86 b = a? 8 : 487};88 89void diags(int n) {90 switch (n) {91 case (1/0, 1): // expected-error {{not an integral constant expression}} expected-note {{division by zero}} expected-warning {{left operand of comma operator has no effect}}92 case (int)(1/0, 2.0): // expected-error {{not an integral constant expression}} expected-note {{division by zero}} expected-warning {{left operand of comma operator has no effect}}93 case __imag(1/0): // expected-error {{not an integral constant expression}} expected-note {{division by zero}}94 case (int)__imag((double)(1/0)): // expected-error {{not an integral constant expression}} expected-note {{division by zero}}95 ;96 }97}98 99namespace IntOrEnum {100 const int k = 0;101 const int &p = k; // expected-note {{declared here}}102 template<int n> struct S {};103 S<p> s; // expected-error {{not an integral constant expression}} expected-note {{read of variable 'p' of non-integral, non-enumeration type 'const int &'}}104}105 106extern const int recurse1;107// recurse2 cannot be used in a constant expression because it is not108// initialized by a constant expression. The same expression appearing later in109// the TU would be a constant expression, but here it is not.110const int recurse2 = recurse1; // expected-note {{here}}111const int recurse1 = 1;112int array1[recurse1]; // ok113int array2[recurse2]; // expected-warning 2{{variable length array}} expected-note {{initializer of 'recurse2' is not a constant expression}}114 115namespace FloatConvert {116 typedef int a[(int)42.3];117 typedef int a[(int)42.997];118 typedef int b[(long long)4e20]; // expected-warning {{variable length}} expected-error {{variable length}} expected-warning {{'long long' is a C++11 extension}} expected-note {{value 4.0E+20 is outside the range of representable values}}119}120 121// PR12626122namespace test3 {123 struct X; // expected-note {{forward declaration of 'test3::X'}}124 struct Y { bool b; X x; }; // expected-error {{field has incomplete type 'X'}}125 int f() { return Y().b; }126}127 128// PR18283129namespace test4 {130 template <int> struct A {};131 int const i = { 42 };132 // i can be used as non-type template-parameter as "const int x = { 42 };" is133 // equivalent to "const int x = 42;" as per C++03 8.5/p13.134 typedef A<i> Ai; // ok135}136 137namespace rdar16064952 {138 template < typename T > void fn1() {139 T b;140 unsigned w = ({int a = b.val[sizeof(0)]; 0; }); // expected-warning {{use of GNU statement expression extension}}141 }142}143 144char PR17381_ice = 1000000 * 1000000; // expected-warning {{overflow}} expected-warning {{changes value}}145 146namespace PR31701 {147 struct C {148 template<int i> static int n; // expected-warning {{extension}}149 };150 template <int M> class D;151 template <int M>152 template<int i> void D<M>::set() { // expected-error {{from class 'PR31701::D<M>' without definition}}153 const C c = C::n<i>;154 }155}156 157struct PR65784s{158 int *ptr;159} const PR65784[] = {(int *)""};160PR65784s PR65784f() { return *PR65784; }161