clang/test/Analysis/constraint_manager_negate.c

   1 // RUN: %clang_analyze_cc1 -analyzer-checker=debug.ExprInspection,core.builtin \
   2 // RUN:   -analyzer-config eagerly-assume=false \
   3 // RUN:   -verify %s
   4
   5 void clang_analyzer_eval(int);
   6 void clang_analyzer_dump(int);
   7
   8 void exit(int);
   9
  10 #define UINT_MIN (0U)
  11 #define UINT_MAX (~UINT_MIN)
  12 #define UINT_MID (UINT_MAX / 2 + 1)
  13 #define INT_MAX (UINT_MAX & (UINT_MAX >> 1))
  14 #define INT_MIN (UINT_MAX & ~(UINT_MAX >> 1))
  15
  16 extern void abort() __attribute__((__noreturn__));
  17 #define assert(expr) ((expr) ? (void)(0) : abort())
  18
  19 void negate_positive_range(int a) {
  20   assert(-a > 0);
  21   // -a: [1, INT_MAX]
  22   // a: [INT_MIN + 1, -1]
  23   clang_analyzer_eval(a < 0); // expected-warning{{TRUE}}
  24   clang_analyzer_eval(a > INT_MIN); // expected-warning{{TRUE}}
  25 }
  26
  27 void negate_positive_range2(int a) {
  28   assert(a > 0);
  29   // a: [1, INT_MAX]
  30   // -a: [INT_MIN + 1, -1]
  31   clang_analyzer_eval(-a < 0); // expected-warning{{TRUE}}
  32   clang_analyzer_eval(-a > INT_MIN); // expected-warning{{TRUE}}
  33 }
  34
  35 // INT_MIN equals 0b100...00.
  36 // Its two's compelement is 0b011...11 + 1 = 0b100...00 (itself).
  37 _Static_assert(INT_MIN == -INT_MIN, "");
  38 void negate_int_min(int a) {
  39   assert(a == INT_MIN);
  40   clang_analyzer_eval(-a == INT_MIN); // expected-warning{{TRUE}}
  41 }
  42
  43 void negate_mixed(int a) {
  44   assert(a > 0 || a == INT_MIN);
  45   clang_analyzer_eval(-a <= 0); // expected-warning{{TRUE}}
  46 }
  47
  48 void effective_range(int a) {
  49   assert(a >= 0);
  50   assert(-a >= 0);
  51   clang_analyzer_eval(a == 0); // expected-warning{{TRUE}}
  52   clang_analyzer_eval(-a == 0); // expected-warning{{TRUE}}
  53 }
  54
  55 _Static_assert(-INT_MIN == INT_MIN, "");
  56 void effective_range_2(int a) {
  57   assert(a <= 0);
  58   assert(-a <= 0);
  59   clang_analyzer_eval(a == 0 || a == INT_MIN); // expected-warning{{TRUE}}
  60 }
  61
  62 void negate_symexpr(int a, int b) {
  63   assert(3 <= a * b && a * b <= 5);
  64   clang_analyzer_eval(-(a * b) >= -5); // expected-warning{{TRUE}}
  65   clang_analyzer_eval(-(a * b) <= -3); // expected-warning{{TRUE}}
  66 }
  67
  68 void negate_unsigned_min(unsigned a) {
  69   assert(a == UINT_MIN);
  70   clang_analyzer_eval(-a == UINT_MIN); // expected-warning{{TRUE}}
  71   clang_analyzer_eval(-a != UINT_MIN); // expected-warning{{FALSE}}
  72   clang_analyzer_eval(-a > UINT_MIN);  // expected-warning{{FALSE}}
  73   clang_analyzer_eval(-a < UINT_MIN);  // expected-warning{{FALSE}}
  74 }
  75
  76 _Static_assert(7u - 3u != 3u - 7u, "");
  77 _Static_assert(-4u == UINT_MAX - 3u, "");
  78 void negate_unsigned_4(unsigned a) {
  79   assert(a == 4u);
  80   clang_analyzer_eval(-a == 4u); // expected-warning{{FALSE}}
  81   clang_analyzer_eval(-a != 4u); // expected-warning{{TRUE}}
  82   clang_analyzer_eval(-a == UINT_MAX - 3u); // expected-warning{{TRUE}}
  83 }
  84
  85 // UINT_MID equals 0b100...00.
  86 // Its two's compelement is 0b011...11 + 1 = 0b100...00 (itself).
  87 _Static_assert(UINT_MID == -UINT_MID, "");
  88 void negate_unsigned_mid(unsigned a) {
  89   assert(a == UINT_MID);
  90   clang_analyzer_eval(-a == UINT_MID); // expected-warning{{TRUE}}
  91   clang_analyzer_eval(-a != UINT_MID); // expected-warning{{FALSE}}
  92 }
  93
  94 void negate_unsigned_mid2(unsigned a) {
  95   assert(UINT_MIN < a && a < UINT_MID);
  96   // a:  [UINT_MIN+1, UINT_MID-1]
  97   // -a: [UINT_MID+1, UINT_MAX]
  98   clang_analyzer_eval(-a > UINT_MID); // expected-warning{{TRUE}}
  99   clang_analyzer_eval(-a <= UINT_MAX); // expected-warning{{TRUE}}
 100 }
 101
 102 _Static_assert(1u - 2u == UINT_MAX, "");
 103 _Static_assert(2u - 1u == 1, "");
 104 void negate_unsigned_max(unsigned a) {
 105   assert(a == UINT_MAX);
 106   clang_analyzer_eval(-a == 1); // expected-warning{{TRUE}}
 107   clang_analyzer_eval(-a != 1); // expected-warning{{FALSE}}
 108 }
 109 void negate_unsigned_one(unsigned a) {
 110   assert(a == 1);
 111   clang_analyzer_eval(-a == UINT_MAX); // expected-warning{{TRUE}}
 112   clang_analyzer_eval(-a < UINT_MAX);  // expected-warning{{FALSE}}
 113 }