summaryrefslogtreecommitdiffstats
path: root/tests/debuginfo/struct-with-destructor.rs
blob: 4334cd9028b89046b397af8946d3beaa5ea0b251 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
// min-lldb-version: 310

// compile-flags:-g

// === GDB TESTS ===================================================================================

// gdb-command:run
// gdb-command:print simple
// gdbg-check:$1 = {x = 10, y = 20}
// gdbr-check:$1 = struct_with_destructor::WithDestructor {x: 10, y: 20}

// gdb-command:print noDestructor
// gdbg-check:$2 = {a = {x = 10, y = 20}, guard = -1}
// gdbr-check:$2 = struct_with_destructor::NoDestructorGuarded {a: struct_with_destructor::NoDestructor {x: 10, y: 20}, guard: -1}

// gdb-command:print withDestructor
// gdbg-check:$3 = {a = {x = 10, y = 20}, guard = -1}
// gdbr-check:$3 = struct_with_destructor::WithDestructorGuarded {a: struct_with_destructor::WithDestructor {x: 10, y: 20}, guard: -1}

// gdb-command:print nested
// gdbg-check:$4 = {a = {a = {x = 7890, y = 9870}}}
// gdbr-check:$4 = struct_with_destructor::NestedOuter {a: struct_with_destructor::NestedInner {a: struct_with_destructor::WithDestructor {x: 7890, y: 9870}}}


// === LLDB TESTS ==================================================================================

// lldb-command:run
// lldb-command:print simple
// lldbg-check:[...]$0 = { x = 10 y = 20 }
// lldbr-check:(struct_with_destructor::WithDestructor) simple = { x = 10 y = 20 }

// lldb-command:print noDestructor
// lldbg-check:[...]$1 = { a = { x = 10 y = 20 } guard = -1 }
// lldbr-check:(struct_with_destructor::NoDestructorGuarded) noDestructor = { a = { x = 10 y = 20 } guard = -1 }

// lldb-command:print withDestructor
// lldbg-check:[...]$2 = { a = { x = 10 y = 20 } guard = -1 }
// lldbr-check:(struct_with_destructor::WithDestructorGuarded) withDestructor = { a = { x = 10 y = 20 } guard = -1 }

// lldb-command:print nested
// lldbg-check:[...]$3 = { a = { a = { x = 7890 y = 9870 } } }
// lldbr-check:(struct_with_destructor::NestedOuter) nested = { a = { a = { x = 7890 y = 9870 } } }

#![allow(unused_variables)]
#![feature(omit_gdb_pretty_printer_section)]
#![omit_gdb_pretty_printer_section]

struct NoDestructor {
    x: i32,
    y: i64
}

struct WithDestructor {
    x: i32,
    y: i64
}

impl Drop for WithDestructor {
    fn drop(&mut self) {}
}

struct NoDestructorGuarded {
    a: NoDestructor,
    guard: i64
}

struct WithDestructorGuarded {
    a: WithDestructor,
    guard: i64
}

struct NestedInner {
    a: WithDestructor
}

impl Drop for NestedInner {
    fn drop(&mut self) {}
}

struct NestedOuter {
    a: NestedInner
}


// The compiler adds a 'destructed' boolean field to structs implementing Drop. This field is used
// at runtime to prevent drop() to be executed more than once.
// This field must be incorporated by the debug info generation. Otherwise the debugger assumes a
// wrong size/layout for the struct.
fn main() {

    let simple = WithDestructor { x: 10, y: 20 };

    let noDestructor = NoDestructorGuarded {
        a: NoDestructor { x: 10, y: 20 },
        guard: -1
    };

    // If the destructor flag field is not incorporated into the debug info for 'WithDestructor'
    // then the debugger will have an invalid offset for the field 'guard' and thus should not be
    // able to read its value correctly (dots are padding bytes, D is the boolean destructor flag):
    //
    // 64 bit
    //
    // NoDestructorGuarded = 0000....00000000FFFFFFFF
    //                       <--------------><------>
    //                         NoDestructor   guard
    //
    //
    // withDestructorGuarded = 0000....00000000D.......FFFFFFFF
    //                         <--------------><------>          // How debug info says it is
    //                          WithDestructor  guard
    //
    //                         <----------------------><------>  // How it actually is
    //                              WithDestructor      guard
    //
    // 32 bit
    //
    // NoDestructorGuarded = 000000000000FFFFFFFF
    //                       <----------><------>
    //                       NoDestructor guard
    //
    //
    // withDestructorGuarded = 000000000000D...FFFFFFFF
    //                         <----------><------>      // How debug info says it is
    //                      WithDestructor  guard
    //
    //                         <--------------><------>  // How it actually is
    //                          WithDestructor  guard
    //
    let withDestructor = WithDestructorGuarded {
        a: WithDestructor { x: 10, y: 20 },
        guard: -1
    };

    // expected layout (64 bit) = xxxx....yyyyyyyyD.......D...
    //                            <--WithDestructor------>
    //                            <-------NestedInner-------->
    //                            <-------NestedOuter-------->
    let nested = NestedOuter { a: NestedInner { a: WithDestructor { x: 7890, y: 9870 } } };

    zzz(); // #break
}

fn zzz() {()}