1 // RUN: %clang_analyze_cc1 -analyzer-checker=security.PointerSub -analyzer-output=text -verify %s 2 3 void different_1() { 4 int a[3]; // expected-note{{Array at the left-hand side of subtraction}} 5 int b[3]; // expected-note{{Array at the right-hand side of subtraction}} 6 int d = &a[2] - &b[0]; // expected-warning{{Subtraction of two pointers that do not point into the same array is undefined behavior}} \ 7 // expected-note{{Subtraction of two pointers that do not point into the same array is undefined behavior}} 8 } 9 10 void different_2() { 11 int a[3]; // expected-note{{Array at the right-hand side of subtraction}} 12 int b[3]; // expected-note{{Array at the left-hand side of subtraction}} 13 int *p1 = a + 1; 14 int *p2 = b; 15 int d = p2 - p1; // expected-warning{{Subtraction of two pointers that do not point into the same array is undefined behavior}} \ 16 // expected-note{{Subtraction of two pointers that do not point into the same array is undefined behavior}} 17 } 18 19 int different_3() { 20 struct { 21 int array[5]; 22 } a, b; 23 return &a.array[3] - &b.array[2]; // expected-warning{{Subtraction of two pointers that do not point into the same array is undefined behavior}} \ 24 // expected-note{{Subtraction of two pointers that do not point into the same array is undefined behavior}} 25 } 26 27 int different_4() { 28 struct { 29 int array1[5]; // expected-note{{Array at the left-hand side of subtraction}} 30 int array2[5]; // expected-note{{Array at the right-hand side of subtraction}} 31 } a; 32 return &a.array1[3] - &a.array2[4]; // expected-warning{{Subtraction of two pointers that do not point into the same array is undefined behavior}} \ 33 // expected-note{{Subtraction of two pointers that do not point into the same array is undefined behavior}} 34 } 35 36 void different_5() { 37 int d; 38 static int x[10][10]; // expected-note2{{Array at the left-hand side of subtraction}} 39 int *y1 = &(x[3][5]); 40 char *z = ((char *) y1) + 2; 41 int *y2 = (int *)(z - 2); 42 int *y3 = ((int *)x) + 35; // This is offset for [3][5]. 43 44 d = y2 - y1; // expected-warning{{Subtraction of two pointers that do not point into the same array is undefined behavior}} \ 45 // expected-note{{Subtraction of two pointers that do not point into the same array is undefined behavior}} 46 d = y3 - y1; // expected-warning{{Subtraction of two pointers that do not point into the same array is undefined behavior}} \ 47 // expected-note{{Subtraction of two pointers that do not point into the same array is undefined behavior}} 48 d = y3 - y2; 49 } 50