xref: /llvm-project/clang/test/Analysis/pointer-sub-notes.c (revision 0d384fe978f9675be9fe960940daa2fd599104ed)
1*0d384fe9SBalázs Kéri // RUN: %clang_analyze_cc1 -analyzer-checker=security.PointerSub -analyzer-output=text -verify %s
2c43d5f54SBalázs Kéri 
3c43d5f54SBalázs Kéri void different_1() {
4c43d5f54SBalázs Kéri   int a[3]; // expected-note{{Array at the left-hand side of subtraction}}
5c43d5f54SBalázs Kéri   int b[3]; // expected-note{{Array at the right-hand side of subtraction}}
6c43d5f54SBalázs Kéri   int d = &a[2] - &b[0]; // expected-warning{{Subtraction of two pointers that do not point into the same array is undefined behavior}} \
7c43d5f54SBalázs Kéri                          // expected-note{{Subtraction of two pointers that do not point into the same array is undefined behavior}}
8c43d5f54SBalázs Kéri }
9c43d5f54SBalázs Kéri 
10c43d5f54SBalázs Kéri void different_2() {
11c43d5f54SBalázs Kéri   int a[3]; // expected-note{{Array at the right-hand side of subtraction}}
12c43d5f54SBalázs Kéri   int b[3]; // expected-note{{Array at the left-hand side of subtraction}}
13c43d5f54SBalázs Kéri   int *p1 = a + 1;
14c43d5f54SBalázs Kéri   int *p2 = b;
15c43d5f54SBalázs Kéri   int d = p2 - p1; // expected-warning{{Subtraction of two pointers that do not point into the same array is undefined behavior}} \
16c43d5f54SBalázs Kéri                    // expected-note{{Subtraction of two pointers that do not point into the same array is undefined behavior}}
17c43d5f54SBalázs Kéri }
18c43d5f54SBalázs Kéri 
19c43d5f54SBalázs Kéri int different_3() {
20c43d5f54SBalázs Kéri   struct {
21c43d5f54SBalázs Kéri     int array[5];
22c43d5f54SBalázs Kéri   } a, b;
23c43d5f54SBalázs Kéri   return &a.array[3] - &b.array[2]; // expected-warning{{Subtraction of two pointers that do not point into the same array is undefined behavior}} \
24c43d5f54SBalázs Kéri                                     // expected-note{{Subtraction of two pointers that do not point into the same array is undefined behavior}}
25c43d5f54SBalázs Kéri }
26c43d5f54SBalázs Kéri 
27c43d5f54SBalázs Kéri int different_4() {
28c43d5f54SBalázs Kéri   struct {
29c43d5f54SBalázs Kéri     int array1[5]; // expected-note{{Array at the left-hand side of subtraction}}
30c43d5f54SBalázs Kéri     int array2[5]; // expected-note{{Array at the right-hand side of subtraction}}
31c43d5f54SBalázs Kéri   } a;
32c43d5f54SBalázs Kéri   return &a.array1[3] - &a.array2[4]; // expected-warning{{Subtraction of two pointers that do not point into the same array is undefined behavior}} \
33c43d5f54SBalázs Kéri                                       // expected-note{{Subtraction of two pointers that do not point into the same array is undefined behavior}}
34c43d5f54SBalázs Kéri }
35c43d5f54SBalázs Kéri 
36c43d5f54SBalázs Kéri void different_5() {
37c43d5f54SBalázs Kéri   int d;
38c43d5f54SBalázs Kéri   static int x[10][10]; // expected-note2{{Array at the left-hand side of subtraction}}
39c43d5f54SBalázs Kéri   int *y1 = &(x[3][5]);
40c43d5f54SBalázs Kéri   char *z = ((char *) y1) + 2;
41c43d5f54SBalázs Kéri   int *y2 = (int *)(z - 2);
42c43d5f54SBalázs Kéri   int *y3 = ((int *)x) + 35; // This is offset for [3][5].
43c43d5f54SBalázs Kéri 
44c43d5f54SBalázs Kéri   d = y2 - y1; // expected-warning{{Subtraction of two pointers that do not point into the same array is undefined behavior}} \
45c43d5f54SBalázs Kéri                // expected-note{{Subtraction of two pointers that do not point into the same array is undefined behavior}}
46c43d5f54SBalázs Kéri   d = y3 - y1; // expected-warning{{Subtraction of two pointers that do not point into the same array is undefined behavior}} \
47c43d5f54SBalázs Kéri                // expected-note{{Subtraction of two pointers that do not point into the same array is undefined behavior}}
48c43d5f54SBalázs Kéri   d = y3 - y2;
49c43d5f54SBalázs Kéri }
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