clang/test/SemaCXX/constexpr-function-recovery-crash.cpp

   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 + {{}}