seh-safe-div.ll
5.34 KB
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
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
; RUN: llc -mtriple x86_64-pc-windows-msvc < %s | FileCheck %s
; This test case is also intended to be run manually as a complete functional
; test. It should link, print something, and exit zero rather than crashing.
; It is the hypothetical lowering of a C source program that looks like:
;
; int safe_div(int *n, int *d) {
; int r;
; __try {
; __try {
; r = *n / *d;
; } __except(GetExceptionCode() == EXCEPTION_ACCESS_VIOLATION) {
; puts("EXCEPTION_ACCESS_VIOLATION");
; r = -1;
; }
; } __except(GetExceptionCode() == EXCEPTION_INT_DIVIDE_BY_ZERO) {
; puts("EXCEPTION_INT_DIVIDE_BY_ZERO");
; r = -2;
; }
; return r;
; }
@str1 = internal constant [27 x i8] c"EXCEPTION_ACCESS_VIOLATION\00"
@str2 = internal constant [29 x i8] c"EXCEPTION_INT_DIVIDE_BY_ZERO\00"
define i32 @safe_div(i32* %n, i32* %d) personality i8* bitcast (i32 (...)* @__C_specific_handler to i8*) {
entry:
%r = alloca i32, align 4
invoke void @try_body(i32* %r, i32* %n, i32* %d)
to label %__try.cont unwind label %lpad0
lpad0:
%cs0 = catchswitch within none [label %handler0] unwind label %lpad1
handler0:
%p0 = catchpad within %cs0 [i8* bitcast (i32 (i8*, i8*)* @safe_div_filt0 to i8*)]
call void @puts(i8* getelementptr ([27 x i8], [27 x i8]* @str1, i32 0, i32 0)) [ "funclet"(token %p0) ]
store i32 -1, i32* %r, align 4
catchret from %p0 to label %__try.cont
lpad1:
%cs1 = catchswitch within none [label %handler1] unwind to caller
handler1:
%p1 = catchpad within %cs1 [i8* bitcast (i32 (i8*, i8*)* @safe_div_filt1 to i8*)]
call void @puts(i8* getelementptr ([29 x i8], [29 x i8]* @str2, i32 0, i32 0)) [ "funclet"(token %p1) ]
store i32 -2, i32* %r, align 4
catchret from %p1 to label %__try.cont
__try.cont:
%safe_ret = load i32, i32* %r, align 4
ret i32 %safe_ret
}
; Normal path code
; CHECK: {{^}}safe_div:
; CHECK: .seh_proc safe_div
; CHECK: .seh_handler __C_specific_handler, @unwind, @except
; CHECK: .Ltmp0:
; CHECK: leaq [[rloc:.*\(%rbp\)]], %rcx
; CHECK: callq try_body
; CHECK-NEXT: .Ltmp1
; CHECK: [[cont_bb:\.LBB0_[0-9]+]]:
; CHECK: movl [[rloc]], %eax
; CHECK: retq
; Landing pad code
; CHECK: [[handler1:\.LBB0_[0-9]+]]: # %handler1
; CHECK: callq puts
; CHECK: movl $-2, [[rloc]]
; CHECK: jmp [[cont_bb]]
; CHECK: [[handler0:\.LBB0_[0-9]+]]: # %handler0
; CHECK: callq puts
; CHECK: movl $-1, [[rloc]]
; CHECK: jmp [[cont_bb]]
; CHECK: .seh_handlerdata
; CHECK-NEXT: .Lsafe_div$parent_frame_offset
; CHECK-NEXT: .long (.Llsda_end0-.Llsda_begin0)/16
; CHECK-NEXT: .Llsda_begin0:
; CHECK-NEXT: .long .Ltmp0@IMGREL+1
; CHECK-NEXT: .long .Ltmp1@IMGREL+1
; CHECK-NEXT: .long safe_div_filt0@IMGREL
; CHECK-NEXT: .long [[handler0]]@IMGREL
; CHECK-NEXT: .long .Ltmp0@IMGREL+1
; CHECK-NEXT: .long .Ltmp1@IMGREL+1
; CHECK-NEXT: .long safe_div_filt1@IMGREL
; CHECK-NEXT: .long [[handler1]]@IMGREL
; CHECK-NEXT: .Llsda_end0:
; CHECK: .text
; CHECK: .seh_endproc
define void @try_body(i32* %r, i32* %n, i32* %d) {
entry:
%0 = load i32, i32* %n, align 4
%1 = load i32, i32* %d, align 4
%div = sdiv i32 %0, %1
store i32 %div, i32* %r, align 4
ret void
}
; The prototype of these filter functions is:
; int filter(EXCEPTION_POINTERS *eh_ptrs, void *rbp);
; The definition of EXCEPTION_POINTERS is:
; typedef struct _EXCEPTION_POINTERS {
; EXCEPTION_RECORD *ExceptionRecord;
; CONTEXT *ContextRecord;
; } EXCEPTION_POINTERS;
; The definition of EXCEPTION_RECORD is:
; typedef struct _EXCEPTION_RECORD {
; DWORD ExceptionCode;
; ...
; } EXCEPTION_RECORD;
; The exception code can be retreived with two loads, one for the record
; pointer and one for the code. The values of local variables can be
; accessed via rbp, but that would require additional not yet implemented LLVM
; support.
define i32 @safe_div_filt0(i8* %eh_ptrs, i8* %rbp) {
%eh_ptrs_c = bitcast i8* %eh_ptrs to i32**
%eh_rec = load i32*, i32** %eh_ptrs_c
%eh_code = load i32, i32* %eh_rec
; EXCEPTION_ACCESS_VIOLATION = 0xC0000005
%cmp = icmp eq i32 %eh_code, 3221225477
%filt.res = zext i1 %cmp to i32
ret i32 %filt.res
}
define i32 @safe_div_filt1(i8* %eh_ptrs, i8* %rbp) {
%eh_ptrs_c = bitcast i8* %eh_ptrs to i32**
%eh_rec = load i32*, i32** %eh_ptrs_c
%eh_code = load i32, i32* %eh_rec
; EXCEPTION_INT_DIVIDE_BY_ZERO = 0xC0000094
%cmp = icmp eq i32 %eh_code, 3221225620
%filt.res = zext i1 %cmp to i32
ret i32 %filt.res
}
@str_result = internal constant [21 x i8] c"safe_div result: %d\0A\00"
define i32 @main() {
%d.addr = alloca i32, align 4
%n.addr = alloca i32, align 4
store i32 10, i32* %n.addr, align 4
store i32 2, i32* %d.addr, align 4
%r1 = call i32 @safe_div(i32* %n.addr, i32* %d.addr)
call void (i8*, ...) @printf(i8* getelementptr ([21 x i8], [21 x i8]* @str_result, i32 0, i32 0), i32 %r1)
store i32 10, i32* %n.addr, align 4
store i32 0, i32* %d.addr, align 4
%r2 = call i32 @safe_div(i32* %n.addr, i32* %d.addr)
call void (i8*, ...) @printf(i8* getelementptr ([21 x i8], [21 x i8]* @str_result, i32 0, i32 0), i32 %r2)
%r3 = call i32 @safe_div(i32* %n.addr, i32* null)
call void (i8*, ...) @printf(i8* getelementptr ([21 x i8], [21 x i8]* @str_result, i32 0, i32 0), i32 %r3)
ret i32 0
}
declare i32 @__C_specific_handler(...)
declare i32 @llvm.eh.typeid.for(i8*) readnone nounwind
declare void @puts(i8*)
declare void @printf(i8*, ...)
declare void @abort()