clang/test/Analysis/constraint-assignor.c

   1 // RUN: %clang_analyze_cc1 %s \
   2 // RUN:   -analyzer-checker=core \
   3 // RUN:   -analyzer-checker=debug.ExprInspection \
   4 // RUN:   -verify
   5
   6 void clang_analyzer_warnIfReached(void);
   7 void clang_analyzer_eval(int);
   8
   9 void rem_constant_rhs_ne_zero(int x, int y) {
  10   if (x % 3 == 0) // x % 3 != 0 -> x != 0
  11     return;
  12   if (x * y != 0) // x * y == 0
  13     return;
  14   if (y != 1)     // y == 1     -> x == 0
  15     return;
  16   clang_analyzer_warnIfReached(); // no-warning
  17   (void)x; // keep the constraints alive.
  18 }
  19
  20 void rem_symbolic_rhs_ne_zero(int x, int y, int z) {
  21   if (x % z == 0) // x % z != 0 -> x != 0
  22     return;
  23   if (x * y != 0) // x * y == 0
  24     return;
  25   if (y != 1)     // y == 1     -> x == 0
  26     return;
  27   clang_analyzer_warnIfReached(); // no-warning
  28   (void)x; // keep the constraints alive.
  29 }
  30
  31 void rem_symbolic_rhs_ne_zero_nested(int w, int x, int y, int z) {
  32   if (w % x % z == 0) // w % x % z != 0 -> w % x != 0
  33     return;
  34   if (w % x * y != 0) // w % x * y == 0
  35     return;
  36   if (y != 1)         // y == 1         -> w % x == 0
  37     return;
  38   clang_analyzer_warnIfReached(); // no-warning
  39   (void)(w * x); // keep the constraints alive.
  40 }
  41
  42 void rem_constant_rhs_ne_zero_early_contradiction(int x, int y) {
  43   if ((x + y) != 0)     // (x + y) == 0
  44     return;
  45   if ((x + y) % 3 == 0) // (x + y) % 3 != 0 -> (x + y) != 0 -> contradiction
  46     return;
  47   clang_analyzer_warnIfReached(); // no-warning
  48   (void)x; // keep the constraints alive.
  49 }
  50
  51 void rem_symbolic_rhs_ne_zero_early_contradiction(int x, int y, int z) {
  52   if ((x + y) != 0)     // (x + y) == 0
  53     return;
  54   if ((x + y) % z == 0) // (x + y) % z != 0 -> (x + y) != 0 -> contradiction
  55     return;
  56   clang_analyzer_warnIfReached(); // no-warning
  57   (void)x; // keep the constraints alive.
  58 }
  59
  60 void internal_unsigned_signed_mismatch(unsigned a) {
  61   int d = a;
  62   // Implicit casts are not handled, thus the analyzer models `d % 2` as
  63   // `(reg_$0<unsigned int a>) % 2`
  64   // However, this should not result in internal signedness mismatch error when
  65   // we assign new constraints below.
  66   if (d % 2 != 0)
  67     return;
  68 }
  69
  70 void remainder_with_adjustment(int x) {
  71   if ((x + 1) % 3 == 0) // (x + 1) % 3 != 0 -> x + 1 != 0 -> x != -1
  72     return;
  73   clang_analyzer_eval(x + 1 != 0); // expected-warning{{TRUE}}
  74   clang_analyzer_eval(x != -1);    // expected-warning{{TRUE}}
  75   (void)x; // keep the constraints alive.
  76 }
  77
  78 void remainder_with_adjustment_of_composit_lhs(int x, int y) {
  79   if ((x + y + 1) % 3 == 0) // (x + 1) % 3 != 0 -> x + 1 != 0 -> x != -1
  80     return;
  81   clang_analyzer_eval(x + y + 1 != 0); // expected-warning{{TRUE}}
  82   clang_analyzer_eval(x + y != -1);    // expected-warning{{TRUE}}
  83   (void)(x * y); // keep the constraints alive.
  84 }