cast-to-struct.cpp source code [clang_source_code/test/Analysis/cast-to-struct.cpp]

1	// RUN: %clang_analyze_cc1 -analyzer-checker=alpha.core.CastToStruct,core -verify %s
2
3	struct AB {
4	int A;
5	int B;
6	};
7
8	struct ABC {
9	int A;
10	int B;
11	int C;
12	};
13
14	struct Base {
15	Base() : A(0), B(0) {}
16	virtual ~Base() {}
17
18	int A;
19	int B;
20	};
21
22	struct Derived : public Base {
23	Derived() : Base(), C(0) {}
24	int C;
25	};
26
27	void structToStruct(struct AB *P) {
28	struct AB Ab;
29	struct ABC *Abc;
30	Abc = (struct ABC *)&Ab; // expected-warning {{Casting data to a larger structure type and accessing a field can lead to memory access errors or data corruption}}
31	Abc = (struct ABC *)P; // No warning; It is not known what data P points at.
32	Abc = (struct ABC )&P;
33
34	// Don't warn when the cast is not widening.
35	P = (struct AB )&Ab; // struct AB => struct AB *
36	struct ABC Abc2;
37	P = (struct AB )&Abc2; // struct ABC => struct AB *
38
39	// True negatives when casting from Base to Derived.
40	Derived D1, *D2;
41	Base &B1 = D1;
42	D2 = (Derived *)&B1;
43	D2 = dynamic_cast<Derived *>(&B1);
44	D2 = static_cast<Derived *>(&B1);
45
46	// True positives when casting from Base to Derived.
47	Base B2;
48	D2 = (Derived *)&B2;// expected-warning {{Casting data to a larger structure type and accessing a field can lead to memory access errors or data corruption}}
49	D2 = dynamic_cast<Derived *>(&B2);// expected-warning {{Casting data to a larger structure type and accessing a field can lead to memory access errors or data corruption}}
50	D2 = static_cast<Derived *>(&B2);// expected-warning {{Casting data to a larger structure type and accessing a field can lead to memory access errors or data corruption}}
51
52	// False negatives, cast from Base to Derived. With path sensitive analysis
53	// these false negatives could be fixed.
54	Base *B3 = &B2;
55	D2 = (Derived *)B3;
56	D2 = dynamic_cast<Derived *>(B3);
57	D2 = static_cast<Derived *>(B3);
58	}
59
60	void intToStruct(int *P) {
61	struct ABC *Abc;
62	Abc = (struct ABC *)P; // expected-warning {{Casting a non-structure type to a structure type and accessing a field can lead to memory access errors or data corruption}}
63
64	// Cast from void *.
65	void *VP = P;
66	Abc = (struct ABC *)VP;
67	}
68
69	// https://llvm.org/bugs/show_bug.cgi?id=31173
70	void dontCrash1(struct AB X) {
71	struct UndefS S = (struct UndefS )&X;
72	}
73
74	struct S;
75	struct T {
76	struct S *P;
77	};
78	extern struct S Var1, Var2;
79	void dontCrash2() {
80	((struct T *) &Var1)->P = &Var2;
81	}
82

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