clang/test/Sema/parentheses.c

   1 // RUN: %clang_cc1 -fsyntax-only -verify %s
   2 // RUN: %clang_cc1 -Wparentheses -fsyntax-only -verify %s
   3 // RUN: %clang_cc1 -Wparentheses -fsyntax-only -fdiagnostics-parseable-fixits %s 2>&1 | FileCheck %s
   4
   5 // Test the various warnings under -Wparentheses
   6 void if_assign(void) {
   7   int i;
   8   if (i = 4) {} // expected-warning {{assignment as a condition}} \
   9                 // expected-note{{place parentheses around the assignment to silence this warning}} \
  10                 // expected-note{{use '==' to turn this assignment into an equality comparison}}
  11   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:7-[[@LINE-3]]:7}:"("
  12   // CHECK: fix-it:"{{.*}}":{[[@LINE-4]]:12-[[@LINE-4]]:12}:")"
  13   // CHECK: fix-it:"{{.*}}":{[[@LINE-5]]:9-[[@LINE-5]]:10}:"=="
  14
  15   if ((i = 4)) {}
  16 }
  17
  18 void bitwise_rel(unsigned i) {
  19   (void)(i & 0x2 == 0); // expected-warning {{& has lower precedence than ==}} \
  20                         // expected-note{{place parentheses around the '==' expression to silence this warning}} \
  21                         // expected-note{{place parentheses around the & expression to evaluate it first}}
  22   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:14-[[@LINE-3]]:14}:"("
  23   // CHECK: fix-it:"{{.*}}":{[[@LINE-4]]:22-[[@LINE-4]]:22}:")"
  24   // CHECK: fix-it:"{{.*}}":{[[@LINE-5]]:10-[[@LINE-5]]:10}:"("
  25   // CHECK: fix-it:"{{.*}}":{[[@LINE-6]]:17-[[@LINE-6]]:17}:")"
  26
  27   (void)(0 == i & 0x2); // expected-warning {{& has lower precedence than ==}} \
  28                         // expected-note{{place parentheses around the '==' expression to silence this warning}} \
  29                         // expected-note{{place parentheses around the & expression to evaluate it first}}
  30   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:10-[[@LINE-3]]:10}:"("
  31   // CHECK: fix-it:"{{.*}}":{[[@LINE-4]]:16-[[@LINE-4]]:16}:")"
  32   // CHECK: fix-it:"{{.*}}":{[[@LINE-5]]:15-[[@LINE-5]]:15}:"("
  33   // CHECK: fix-it:"{{.*}}":{[[@LINE-6]]:22-[[@LINE-6]]:22}:")"
  34
  35   (void)(i & 0xff < 30); // expected-warning {{& has lower precedence than <}} \
  36                          // expected-note{{place parentheses around the '<' expression to silence this warning}} \
  37                          // expected-note{{place parentheses around the & expression to evaluate it first}}
  38   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:14-[[@LINE-3]]:14}:"("
  39   // CHECK: fix-it:"{{.*}}":{[[@LINE-4]]:23-[[@LINE-4]]:23}:")"
  40   // CHECK: fix-it:"{{.*}}":{[[@LINE-5]]:10-[[@LINE-5]]:10}:"("
  41   // CHECK: fix-it:"{{.*}}":{[[@LINE-6]]:18-[[@LINE-6]]:18}:")"
  42
  43   (void)((i & 0x2) == 0);
  44   (void)(i & (0x2 == 0));
  45   // Eager logical op
  46   (void)(i == 1 | i == 2 | i == 3);
  47   (void)(i != 1 & i != 2 & i != 3);
  48 }
  49
  50 _Bool someConditionFunc(void);
  51
  52 void conditional_op(int x, int y, _Bool b, void* p) {
  53   (void)(x + someConditionFunc() ? 1 : 2); // expected-warning {{operator '?:' has lower precedence than '+'}} \
  54                                            // expected-note {{place parentheses around the '+' expression to silence this warning}} \
  55                                            // expected-note {{place parentheses around the '?:' expression to evaluate it first}}
  56   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:10-[[@LINE-3]]:10}:"("
  57   // CHECK: fix-it:"{{.*}}":{[[@LINE-4]]:33-[[@LINE-4]]:33}:")"
  58   // CHECK: fix-it:"{{.*}}":{[[@LINE-5]]:14-[[@LINE-5]]:14}:"("
  59   // CHECK: fix-it:"{{.*}}":{[[@LINE-6]]:41-[[@LINE-6]]:41}:")"
  60
  61   (void)((x + someConditionFunc()) ? 1 : 2); // no warning
  62
  63   (void)(x - b ? 1 : 2); // expected-warning {{operator '?:' has lower precedence than '-'}} \
  64                          // expected-note {{place parentheses around the '-' expression to silence this warning}} \
  65                          // expected-note {{place parentheses around the '?:' expression to evaluate it first}}
  66   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:10-[[@LINE-3]]:10}:"("
  67   // CHECK: fix-it:"{{.*}}":{[[@LINE-4]]:15-[[@LINE-4]]:15}:")"
  68   // CHECK: fix-it:"{{.*}}":{[[@LINE-5]]:14-[[@LINE-5]]:14}:"("
  69   // CHECK: fix-it:"{{.*}}":{[[@LINE-6]]:23-[[@LINE-6]]:23}:")"
  70
  71   (void)(x * (x == y) ? 1 : 2); // expected-warning {{operator '?:' has lower precedence than '*'}} \
  72                                 // expected-note {{place parentheses around the '*' expression to silence this warning}} \
  73                                 // expected-note {{place parentheses around the '?:' expression to evaluate it first}}
  74   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:10-[[@LINE-3]]:10}:"("
  75   // CHECK: fix-it:"{{.*}}":{[[@LINE-4]]:22-[[@LINE-4]]:22}:")"
  76   // CHECK: fix-it:"{{.*}}":{[[@LINE-5]]:14-[[@LINE-5]]:14}:"("
  77   // CHECK: fix-it:"{{.*}}":{[[@LINE-6]]:30-[[@LINE-6]]:30}:")"
  78
  79   (void)(x / !x ? 1 : 2); // expected-warning {{operator '?:' has lower precedence than '/'}} \
  80                           // expected-note {{place parentheses around the '/' expression to silence this warning}} \
  81                           // expected-note {{place parentheses around the '?:' expression to evaluate it first}}
  82   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:10-[[@LINE-3]]:10}:"("
  83   // CHECK: fix-it:"{{.*}}":{[[@LINE-4]]:16-[[@LINE-4]]:16}:")"
  84   // CHECK: fix-it:"{{.*}}":{[[@LINE-5]]:14-[[@LINE-5]]:14}:"("
  85   // CHECK: fix-it:"{{.*}}":{[[@LINE-6]]:24-[[@LINE-6]]:24}:")"
  86
  87   (void)(x % 2 ? 1 : 2); // no warning
  88
  89   (void)(x + p ? 1 : 2); // expected-warning {{operator '?:' has lower precedence than '+'}} expected-note 2{{place parentheses}}
  90   (void)(p + x ? 1 : 2); // no warning
  91
  92   (void)(p + b ? 1 : 2); // expected-warning {{operator '?:' has lower precedence than '+'}} expected-note 2{{place parentheses}}
  93
  94   (void)(x + y > 0 ? 1 : 2); // no warning
  95   (void)(x + (y > 0) ? 1 : 2); // expected-warning {{operator '?:' has lower precedence than '+'}} expected-note 2{{place parentheses}}
  96
  97   (void)(b ? 0xf0 : 0x10 | b ? 0x5 : 0x2); // expected-warning {{operator '?:' has lower precedence than '|'}} expected-note 2{{place parentheses}}
  98
  99   (void)((b ? 0xf0 : 0x10) | (b ? 0x5 : 0x2));  // no warning, has parentheses
 100   (void)(b ? 0xf0 : (0x10 | b) ? 0x5 : 0x2);  // no warning, has parentheses
 101
 102   (void)(x | b ? 1 : 2); // expected-warning {{operator '?:' has lower precedence than '|'}} expected-note 2{{place parentheses}}
 103   (void)(x & b ? 1 : 2); // expected-warning {{operator '?:' has lower precedence than '&'}} expected-note 2{{place parentheses}}
 104
 105   (void)((x | b) ? 1 : 2);  // no warning, has parentheses
 106   (void)(x | (b ? 1 : 2));  // no warning, has parentheses
 107   (void)((x & b) ? 1 : 2);  // no warning, has parentheses
 108   (void)(x & (b ? 1 : 2));  // no warning, has parentheses
 109
 110   // Only warn on uses of the bitwise operators, and not the logical operators.
 111   // The bitwise operators are more likely to be bugs while the logical
 112   // operators are more likely to be used correctly.  Since there is no
 113   // explicit logical-xor operator, the bitwise-xor is commonly used instead.
 114   // For this warning, treat the bitwise-xor as if it were a logical operator.
 115   (void)(x ^ b ? 1 : 2);  // no warning, ^ is often used as logical xor
 116   (void)(x || b ? 1 : 2);  // no warning, logical operator
 117   (void)(x && b ? 1 : 2);  // no warning, logical operator
 118 }
 119
 120 // RUN: not %clang_cc1 -fsyntax-only -Wparentheses -Werror %s 2>&1 | FileCheck %s -check-prefix=CHECK-FLAG
 121 // CHECK-FLAG: error: using the result of an assignment as a condition without parentheses [-Werror,-Wparentheses]