test/Analysis/constant-folding.c

   1 // RUN: %clang_cc1 -analyze -analyzer-experimental-internal-checks -analyzer-check-objc-mem -analyzer-experimental-checks -verify %s
   2
   3 // Trigger a warning if the analyzer reaches this point in the control flow.
   4 #define WARN ((void)*(char*)0)
   5
   6 // There should be no warnings unless otherwise indicated.
   7
   8 void testComparisons (int a) {
   9   // Sema can already catch the simple comparison a==a,
  10   // since that's usually a logic error (and not path-dependent).
  11   int b = a;
  12   if (!(b==a)) WARN; // expected-warning{{never executed}}
  13   if (!(b>=a)) WARN; // expected-warning{{never executed}}
  14   if (!(b<=a)) WARN; // expected-warning{{never executed}}
  15   if (b!=a) WARN;    // expected-warning{{never executed}}
  16   if (b>a) WARN;     // expected-warning{{never executed}}
  17   if (b<a) WARN;     // expected-warning{{never executed}}
  18 }
  19
  20 void testSelfOperations (int a) {
  21   if ((a|a) != a) WARN; // expected-warning{{never executed}}
  22   if ((a&a) != a) WARN; // expected-warning{{never executed}}
  23   if ((a^a) != 0) WARN; // expected-warning{{never executed}}
  24   if ((a-a) != 0) WARN; // expected-warning{{never executed}}
  25 }
  26
  27 void testIdempotent (int a) {
  28   if ((a*1) != a) WARN;    // expected-warning{{never executed}}
  29   if ((a/1) != a) WARN;    // expected-warning{{never executed}}
  30   if ((a+0) != a) WARN;    // expected-warning{{never executed}}
  31   if ((a-0) != a) WARN;    // expected-warning{{never executed}}
  32   if ((a<<0) != a) WARN;   // expected-warning{{never executed}}
  33   if ((a>>0) != a) WARN;   // expected-warning{{never executed}}
  34   if ((a^0) != a) WARN;    // expected-warning{{never executed}}
  35   if ((a&(~0)) != a) WARN; // expected-warning{{never executed}}
  36   if ((a|0) != a) WARN;    // expected-warning{{never executed}}
  37 }
  38
  39 void testReductionToConstant (int a) {
  40   if ((a*0) != 0) WARN; // expected-warning{{never executed}}
  41   if ((a&0) != 0) WARN; // expected-warning{{never executed}}
  42   if ((a|(~0)) != (~0)) WARN; // expected-warning{{never executed}}
  43 }
  44
  45 void testSymmetricIntSymOperations (int a) {
  46   if ((2+a) != (a+2)) WARN; // expected-warning{{never executed}}
  47   if ((2*a) != (a*2)) WARN; // expected-warning{{never executed}}
  48   if ((2&a) != (a&2)) WARN; // expected-warning{{never executed}}
  49   if ((2^a) != (a^2)) WARN; // expected-warning{{never executed}}
  50   if ((2|a) != (a|2)) WARN; // expected-warning{{never executed}}
  51 }
  52
  53 void testAsymmetricIntSymOperations (int a) {
  54   if (((~0) >> a) != (~0)) WARN; // expected-warning{{never executed}}
  55   if ((0 >> a) != 0) WARN; // expected-warning{{never executed}}
  56   if ((0 << a) != 0) WARN; // expected-warning{{never executed}}
  57
  58   // Unsigned right shift shifts in zeroes.
  59   if ((((unsigned)(~0)) >> ((unsigned) a)) != ((unsigned)(~0)))
  60     WARN; // expected-warning{{}}
  61 }
  62
  63 void testLocations (char *a) {
  64   char *b = a;
  65   if (!(b==a)) WARN; // expected-warning{{never executed}}
  66   if (!(b>=a)) WARN; // expected-warning{{never executed}}
  67   if (!(b<=a)) WARN; // expected-warning{{never executed}}
  68   if (b!=a) WARN; // expected-warning{{never executed}}
  69   if (b>a) WARN; // expected-warning{{never executed}}
  70   if (b<a) WARN; // expected-warning{{never executed}}
  71   if (b-a) WARN; // expected-warning{{never executed}}
  72 }