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

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