clang/test/SemaCXX/cxx1z-init-statement.cpp

   1 // RUN: %clang_cc1 -std=c++1z -Wno-unused-value -verify %s
   2 // RUN: %clang_cc1 -std=c++17 -Wno-unused-value -verify %s
   3
   4 void testIf() {
   5   int x = 0;
   6   if (x; x) ++x;
   7   if (int t = 0; t) ++t; else --t;
   8
   9   if (int x, y = 0; y) // expected-note 2 {{previous definition is here}}
  10     int x = 0; // expected-error {{redefinition of 'x'}}
  11   else
  12     int x = 0; // expected-error {{redefinition of 'x'}}
  13
  14   if (x; int a = 0) ++a;
  15   if (x, +x; int a = 0) // expected-note 2 {{previous definition is here}}
  16     int a = 0; // expected-error {{redefinition of 'a'}}
  17   else
  18     int a = 0; // expected-error {{redefinition of 'a'}}
  19
  20   if (int b = 0; b)
  21     ;
  22   b = 2; // expected-error {{use of undeclared identifier}}
  23 }
  24
  25 void testSwitch() {
  26   int x = 0;
  27   switch (x; x) {
  28     case 1:
  29       ++x;
  30   }
  31
  32   switch (int x, y = 0; y) {
  33     case 1:
  34       ++x;
  35     default:
  36       ++y;
  37   }
  38
  39   switch (int x, y = 0; y) { // expected-note 2 {{previous definition is here}}
  40     case 0:
  41       int x = 0; // expected-error {{redefinition of 'x'}}
  42     case 1:
  43       int y = 0; // expected-error {{redefinition of 'y'}}
  44   };
  45
  46   switch (x; int a = 0) {
  47     case 0:
  48       ++a;
  49   }
  50
  51   switch (x, +x; int a = 0) { // expected-note {{previous definition is here}}
  52     case 0:
  53       int a = 0; // expected-error {{redefinition of 'a'}} // expected-note {{previous definition is here}}
  54     case 1:
  55       int a = 0; // expected-error {{redefinition of 'a'}}
  56   }
  57
  58   switch (int b = 0; b) {
  59     case 0:
  60       break;
  61   }
  62   b = 2; // expected-error {{use of undeclared identifier}}
  63 }
  64
  65 constexpr bool constexpr_if_init(int n) {
  66   if (int a = n; ++a > 0)
  67     return true;
  68   else
  69     return false;
  70 }
  71
  72 constexpr int constexpr_switch_init(int n) {
  73   switch (int p = n + 2; p) {
  74     case 0:
  75       return 0;
  76     case 1:
  77       return 1;
  78     default:
  79       return -1;
  80   }
  81 }
  82
  83 void test_constexpr_init_stmt() {
  84   constexpr bool a = constexpr_if_init(-2);
  85   static_assert(!a, "");
  86   static_assert(constexpr_if_init(1), "");
  87
  88   constexpr int b = constexpr_switch_init(-1);
  89   static_assert(b == 1, "");
  90   static_assert(constexpr_switch_init(-2) == 0, "");
  91   static_assert(constexpr_switch_init(-5) == -1, "");
  92 }