blob: 744f863bee5d4f952f0fb577fbe180533754bb77 (
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
|
// REQUIRES: x86-registered-target
// RUN: %clang_cl -c --target=x86_64-windows-msvc -EHs-c- -O2 -GS- \
// RUN: -Xclang=-import-call-optimization \
// RUN: -clang:-S -clang:-o- -- %s 2>&1 \
// RUN: | FileCheck %s
#ifdef __clang__
#define NO_TAIL __attribute((disable_tail_calls))
#else
#define NO_TAIL
#endif
void might_throw();
void other_func(int x);
void does_not_throw() noexcept(true);
extern "C" void __declspec(dllimport) some_dll_import();
class HasDtor {
int x;
char foo[40];
public:
explicit HasDtor(int x);
~HasDtor();
};
void normal_has_regions() {
{
HasDtor hd{42};
// because state changes, we expect the HasDtor::HasDtor() call to have a NOP
might_throw();
}
other_func(10);
}
// CHECK-LABEL: .def "?normal_has_regions@@YAXXZ"
// CHECK: .seh_endprologue
// CHECK: call "??0HasDtor@@QEAA@H@Z"
// CHECK-NEXT: call "?might_throw@@YAXXZ"
// CHECK-NEXT: mov
// CHECK: call "??1HasDtor@@QEAA@XZ"
// CHECK-NEXT: mov ecx, 10
// CHECK-NEXT: call "?other_func@@YAXH@Z"
// CHECK-NEXT: nop
// CHECK-NEXT: .seh_startepilogue
// CHECK-NOT: "$ip2state$?normal_has_regions@@YAXXZ"
// This tests a tail call to a destructor.
void case_dtor_arg_empty_body(HasDtor x)
{
}
// CHECK-LABEL: .def "?case_dtor_arg_empty_body@@YAXVHasDtor@@@Z"
// CHECK: jmp "??1HasDtor@@QEAA@XZ"
int case_dtor_arg_empty_with_ret(HasDtor x)
{
// The call to HasDtor::~HasDtor() should NOT have a NOP because the
// following "mov eax, 100" instruction is in the same EH state.
return 100;
}
// CHECK-LABEL: .def "?case_dtor_arg_empty_with_ret@@YAHVHasDtor@@@Z"
// CHECK: .seh_endprologue
// CHECK: call "??1HasDtor@@QEAA@XZ"
// CHECK-NOT: nop
// CHECK: mov eax, 100
// CHECK: .seh_startepilogue
// CHECK: .seh_endepilogue
// CHECK: .seh_endproc
void case_except_simple_call() NO_TAIL
{
does_not_throw();
}
// This tests that the destructor is called right before SEH_BeginEpilogue,
// but in a function that has a return value.
int case_dtor_arg_calls_no_throw(HasDtor x)
{
does_not_throw(); // no NOP expected
return 100;
}
// Check the behavior of CALLs that are at the end of MBBs. If a CALL is within
// a non-null EH state (state -1) and is at the end of an MBB, then we expect
// to find an EH_LABEL after the CALL. This causes us to insert a NOP, which
// is the desired result.
void case_dtor_runs_after_join(int x) {
// ctor call does not need a NOP, because it has real instructions after it
HasDtor hd{42};
if (x) {
might_throw();
} else {
other_func(10);
}
does_not_throw();
// ~HasDtor() runs
}
// CHECK-LABEL: .def "?case_dtor_runs_after_join@@YAXH@Z"
// CHECK: .seh_endprologue
// CHECK: call "??0HasDtor@@QEAA@H@Z"
// CHECK-NEXT: test
// CHECK: call "?might_throw@@YAXXZ"
// CHECK-NEXT: jmp
// CHECK: call "?other_func@@YAXH@Z"
// CHECK-NEXT: .LBB
// CHECK: call "?does_not_throw@@YAXXZ"
// CHECK-NEXT: lea
// CHECK-NEXT: call "??1HasDtor@@QEAA@XZ"
// CHECK-NEXT: nop
// CHECK-NEXT: .seh_startepilogue
// CHECK-NOT: "$ip2state$?case_dtor_runs_after_join@@YAXH@Z":
// Check the behavior of NOP padding around tail calls.
// We do not expect to insert NOPs around tail calls.
// However, the first call (to other_func()) does get a NOP
// because it comes before .seh_startepilogue.
void case_tail_call_no_eh() {
// ordinary call
other_func(10);
// tail call; no NOP padding after JMP
does_not_throw();
}
// CHECK-LABEL: .def "?case_tail_call_no_eh@@YAXXZ"
// CHECK: .seh_endprologue
// CHECK: call "?other_func@@YAXH@Z"
// CHECK-NEXT: nop
// CHECK-NEXT: .seh_startepilogue
// CHECK: .seh_endepilogue
// CHECK: jmp "?does_not_throw@@YAXXZ"
// CHECK-NOT: nop
// CHECK: .seh_endproc
|
