clang/test/Sema/warn-char-subscripts.cpp

   1 // RUN: %clang_cc1 -Wchar-subscripts -fsyntax-only -verify %s
   2
   3 void t1(void) {
   4   int array[1] = { 0 };
   5   char subscript = 0;
   6   int val = array[subscript]; // expected-warning{{array subscript is of type 'char'}}
   7 }
   8
   9 void t2(void) {
  10   int array[1] = { 0 };
  11   char subscript = 0;
  12   int val = subscript[array]; // expected-warning{{array subscript is of type 'char'}}
  13 }
  14
  15 void t3(void) {
  16   int *array = 0;
  17   char subscript = 0;
  18   int val = array[subscript]; // expected-warning{{array subscript is of type 'char'}}
  19 }
  20
  21 void t4(void) {
  22   int *array = 0;
  23   char subscript = 0;
  24   int val = subscript[array]; // expected-warning{{array subscript is of type 'char'}}
  25 }
  26
  27 char returnsChar(void);
  28 void t5(void) {
  29   int *array = 0;
  30   int val = array[returnsChar()]; // expected-warning{{array subscript is of type 'char'}}
  31 }
  32
  33 void t6(void) {
  34   int array[1] = { 0 };
  35   signed char subscript = 0;
  36   int val = array[subscript]; // no warning for explicit signed char
  37 }
  38
  39 void t7(void) {
  40   int array[1] = { 0 };
  41   unsigned char subscript = 0;
  42   int val = array[subscript]; // no warning for unsigned char
  43 }
  44
  45 typedef char CharTy;
  46 void t8(void) {
  47   int array[1] = { 0 };
  48   CharTy subscript = 0;
  49   int val = array[subscript]; // expected-warning{{array subscript is of type 'char'}}
  50 }
  51
  52 typedef signed char SignedCharTy;
  53 void t9(void) {
  54   int array[1] = { 0 };
  55   SignedCharTy subscript = 0;
  56   int val = array[subscript]; // no warning for explicit signed char
  57 }
  58
  59 typedef unsigned char UnsignedCharTy;
  60 void t10(void) {
  61   int array[1] = { 0 };
  62   UnsignedCharTy subscript = 0;
  63   int val = array[subscript]; // no warning for unsigned char
  64 }
  65
  66 void t11(void) {
  67   int array[256] = { 0 };
  68   int val = array['a']; // no warning for char with known positive value
  69 }
  70
  71 void t12(void) {
  72   int array[256] = { 0 };
  73   char b = 'a';
  74   int val = array[b]; // expected-warning{{array subscript is of type 'char'}}
  75 }
  76
  77 void t13(void) {
  78   int array[256] = { 0 };
  79   const char b = 'a';
  80   int val = array[b]; // no warning for char with known positive value
  81 }
  82
  83 void t14(void) {
  84   int array[256] = { 0 };
  85   constexpr char b = 'a';
  86   int val = array[b]; // no warning for char with known positive value
  87 }
  88
  89 void t15(void) {
  90   int array[256] = { 0 }; // expected-note {{array 'array' declared here}}
  91   const char b = -1;
  92   // expected-warning@+2 {{array subscript is of type 'char'}}
  93   // expected-warning@+1 {{array index -1 is before the beginning of the array}}
  94   int val = array[b];
  95 }
  96
  97 void t16(void) {
  98   int array[256] = { 0 }; // expected-note {{array 'array' declared here}}
  99   constexpr char b = -1;
 100   // expected-warning@+2 {{array subscript is of type 'char'}}
 101   // expected-warning@+1 {{array index -1 is before the beginning of the array}}
 102   int val = array[b];
 103 }