1 // RUN: %clang_cc1 %s -std=c++20 -fsyntax-only -fcxx-exceptions -verify
2 
3 // verify no value-dependent-assertion crash in constexpr function body and no
4 // bogus diagnostics.
5 class Foo {
6   constexpr Foo() {
7     while (invalid()) {} // expected-error {{use of undeclared identifier}}
8     if (invalid()) {} // expected-error {{use of undeclared identifier}}
9   }
10 };
11 
12 constexpr void test1() {
13   while (invalid()) {} // expected-error {{use of undeclared identifier}}
14   if (invalid()) {} // expected-error {{use of undeclared identifier}}
15 }
16 
17 struct A {
18   int *p = new int(invalid()); // expected-error {{use of undeclared identifier}}
19   constexpr ~A() { delete p; }
20 };
21 constexpr int test2() {
22   A a;
23   return 1;
24 }
25 
26 constexpr int test3() {
27   return invalid(); // expected-error {{use of undeclared identifier}}
28 }
29 
30 constexpr int test4() {
31   if (invalid()) // expected-error {{use of undeclared identifier}}
32     return 1;
33   else
34     return 0;
35 }
36 
37 constexpr int test5() { // expected-error {{constexpr function never produce}}
38   for (;; a++); // expected-error {{use of undeclared identifier}}  \
39                    expected-note {{constexpr evaluation hit maximum step limit; possible infinite loop?}}
40   return 1;
41 }
42 
43 constexpr int test6() { // expected-error {{constexpr function never produce}}
44   int n = 0;
45   switch (n) {
46     for (;; a++) { // expected-error {{use of undeclared identifier}}
47     case 0:; // expected-note {{constexpr evaluation hit maximum step limit; possible infinite loop?}}
48     }
49   }
50   return 0;
51 }
52 
53 constexpr bool test7() {
54   for (int n = 0; ; invalid()) { if (n == 1) return true; } // expected-error {{use of undeclared identifier}}
55   throw "bad";
56 }
57 
58 constexpr void test8() {
59   do {}  while (invalid()); // expected-error {{use of undeclared identifier}}
60   throw "bad";
61 }
62 
63 template<int x> constexpr int f(int y) { // expected-note {{candidate template ignored}}
64   return x * y;
65 }
66 constexpr int test9(int x) {
67   return f<1>(f<x>(1)); // expected-error {{no matching function for call to 'f'}}
68 }
69 
70 constexpr int test10() { return undef(); } // expected-error {{use of undeclared identifier 'undef'}}
71 static_assert(test10() <= 1, "should not crash"); // expected-error {{static_assert expression is not an integral constant expression}}
72 
73 struct X {} array[] = {undef()}; // expected-error {{use of undeclared identifier 'undef'}}
74 constexpr void test11() {
75   for (X& e : array) {}
76 }
77 
78 constexpr int test12() { return "wrong"; } // expected-error {{cannot initialize return object of type 'int'}}
79 constexpr int force12 = test12();          // expected-error {{must be initialized by a constant}}
80 
81 #define TEST_EVALUATE(Name, X)         \
82   constexpr int testEvaluate##Name() { \
83     X return 0;                        \
84   }                                    \
85   constexpr int forceEvaluate##Name = testEvaluate##Name()
86 // Check that a variety of broken loops don't crash constant evaluation.
87 // We're not checking specific recovery here so don't assert diagnostics.
88 TEST_EVALUATE(Switch, switch (!!){});              // expected-error + {{}}
89 TEST_EVALUATE(SwitchInit, switch (auto x = !!){}); // expected-error + {{}}
90 TEST_EVALUATE(For, for (!!){}); // expected-error + {{}}
91                                 // FIXME: should bail out instead of looping.
92                                 // expected-note@-2 + {{infinite loop}}
93                                 // expected-note@-3 {{in call}}
94 TEST_EVALUATE(ForRange, for (auto x : !!){}); // expected-error + {{}}
95 TEST_EVALUATE(While, while (!!){});           // expected-error + {{}}
96 TEST_EVALUATE(DoWhile, do {} while (!!););    // expected-error + {{}}
97 TEST_EVALUATE(If, if (!!){};);                // expected-error + {{}}
98 TEST_EVALUATE(IfInit, if (auto x = !!; 1){};);// expected-error + {{}}
99 TEST_EVALUATE(ForInit, if (!!;;){};);         // expected-error + {{}}
100 TEST_EVALUATE(ForCond, if (; !!;){};);        // expected-error + {{}}
101 TEST_EVALUATE(ForInc, if (;; !!){};);         // expected-error + {{}}
102