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
| # Source (tiny.cc):
# void a() {}
# void b() {}
# int main(int argc, char** argv) {
# void(*ptr)();
# if (argc == 1)
# ptr = &a;
# else
# ptr = &b;
# ptr();
# }
# Compile with:
# clang++ -gmlt tiny.cc -S -o tiny.s
.text
.file "tiny.cc"
.globl _Z1av # -- Begin function _Z1av
.p2align 4, 0x90
.type _Z1av,@function
_Z1av: # @_Z1av
.Lfunc_begin0:
.file 1 "tiny.cc"
.loc 1 1 0 # tiny.cc:1:0
.cfi_startproc
# %bb.0:
pushq %rbp
.cfi_def_cfa_offset 16
.cfi_offset %rbp, -16
movq %rsp, %rbp
.cfi_def_cfa_register %rbp
.Ltmp0:
.loc 1 1 11 prologue_end # tiny.cc:1:11
popq %rbp
retq
.Ltmp1:
.Lfunc_end0:
.size _Z1av, .Lfunc_end0-_Z1av
.cfi_endproc
# -- End function
.globl _Z1bv # -- Begin function _Z1bv
.p2align 4, 0x90
.type _Z1bv,@function
_Z1bv: # @_Z1bv
.Lfunc_begin1:
.loc 1 2 0 # tiny.cc:2:0
.cfi_startproc
# %bb.0:
pushq %rbp
.cfi_def_cfa_offset 16
.cfi_offset %rbp, -16
movq %rsp, %rbp
.cfi_def_cfa_register %rbp
.Ltmp2:
.loc 1 2 11 prologue_end # tiny.cc:2:11
popq %rbp
retq
.Ltmp3:
.Lfunc_end1:
.size _Z1bv, .Lfunc_end1-_Z1bv
.cfi_endproc
# -- End function
.globl main # -- Begin function main
.p2align 4, 0x90
.type main,@function
main: # @main
.Lfunc_begin2:
.loc 1 4 0 # tiny.cc:4:0
.cfi_startproc
# %bb.0:
pushq %rbp
.cfi_def_cfa_offset 16
.cfi_offset %rbp, -16
movq %rsp, %rbp
.cfi_def_cfa_register %rbp
subq $32, %rsp
movl $0, -4(%rbp)
movl %edi, -8(%rbp)
movq %rsi, -16(%rbp)
.Ltmp4:
.loc 1 6 12 prologue_end # tiny.cc:6:12
cmpl $1, -8(%rbp)
.loc 1 6 7 is_stmt 0 # tiny.cc:6:7
jne .LBB2_2
# %bb.1:
.loc 1 0 7 # tiny.cc:0:7
movabsq $_Z1av, %rax
.loc 1 7 9 is_stmt 1 # tiny.cc:7:9
movq %rax, -24(%rbp)
.loc 1 7 5 is_stmt 0 # tiny.cc:7:5
jmp .LBB2_3
.LBB2_2:
.loc 1 0 5 # tiny.cc:0:5
movabsq $_Z1bv, %rax
.loc 1 9 9 is_stmt 1 # tiny.cc:9:9
movq %rax, -24(%rbp)
.LBB2_3:
.loc 1 11 3 # tiny.cc:11:3
callq *-24(%rbp)
.loc 1 12 1 # tiny.cc:12:1
movl -4(%rbp), %eax
addq $32, %rsp
popq %rbp
retq
.Ltmp5:
.Lfunc_end2:
.size main, .Lfunc_end2-main
.cfi_endproc
# -- End function
.section .debug_str,"MS",@progbits,1
.Linfo_string0:
.asciz "clang version 6.0.0 (trunk 316774)" # string offset=0
.Linfo_string1:
.asciz "tiny.cc" # string offset=35
.Linfo_string2:
.asciz "/tmp/a/b" # string offset=43
.section .debug_abbrev,"",@progbits
.byte 1 # Abbreviation Code
.byte 17 # DW_TAG_compile_unit
.byte 0 # DW_CHILDREN_no
.byte 37 # DW_AT_producer
.byte 14 # DW_FORM_strp
.byte 19 # DW_AT_language
.byte 5 # DW_FORM_data2
.byte 3 # DW_AT_name
.byte 14 # DW_FORM_strp
.byte 16 # DW_AT_stmt_list
.byte 23 # DW_FORM_sec_offset
.byte 27 # DW_AT_comp_dir
.byte 14 # DW_FORM_strp
.byte 17 # DW_AT_low_pc
.byte 1 # DW_FORM_addr
.byte 18 # DW_AT_high_pc
.byte 6 # DW_FORM_data4
.byte 0 # EOM(1)
.byte 0 # EOM(2)
.byte 0 # EOM(3)
.section .debug_info,"",@progbits
.Lcu_begin0:
.long 38 # Length of Unit
.short 4 # DWARF version number
.long .debug_abbrev # Offset Into Abbrev. Section
.byte 8 # Address Size (in bytes)
.byte 1 # Abbrev [1] 0xb:0x1f DW_TAG_compile_unit
.long .Linfo_string0 # DW_AT_producer
.short 4 # DW_AT_language
.long .Linfo_string1 # DW_AT_name
.long .Lline_table_start0 # DW_AT_stmt_list
.long .Linfo_string2 # DW_AT_comp_dir
.quad .Lfunc_begin0 # DW_AT_low_pc
.long .Lfunc_end2-.Lfunc_begin0 # DW_AT_high_pc
.section .debug_ranges,"",@progbits
.section .debug_macinfo,"",@progbits
.Lcu_macro_begin0:
.byte 0 # End Of Macro List Mark
.ident "clang version 6.0.0 (trunk 316774)"
.section ".note.GNU-stack","",@progbits
.section .debug_line,"",@progbits
.Lline_table_start0:
|