xref: /llvm-project/clang/test/Analysis/constraint_manager_negate.c (revision 88abc50398eb26d536518270b91939ce18687305)
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 
negate_positive_range(int a)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 
negate_positive_range2(int a)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, "");
negate_int_min(int a)38 void negate_int_min(int a) {
39   assert(a == INT_MIN);
40   clang_analyzer_eval(-a == INT_MIN); // expected-warning{{TRUE}}
41 }
42 
negate_mixed(int a)43 void negate_mixed(int a) {
44   assert(a > 0 || a == INT_MIN);
45   clang_analyzer_eval(-a <= 0); // expected-warning{{TRUE}}
46 }
47 
effective_range(int a)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, "");
effective_range_2(int a)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 
negate_symexpr(int a,int b)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 
negate_unsigned_min(unsigned a)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, "");
negate_unsigned_4(unsigned a)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, "");
negate_unsigned_mid(unsigned a)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 
negate_unsigned_mid2(unsigned a)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, "");
negate_unsigned_max(unsigned a)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 }
negate_unsigned_one(unsigned a)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 }
114