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
|
// weak_undef_test.cc -- test handling of weak undefined symbols for gold
// Copyright (C) 2008-2015 Free Software Foundation, Inc.
// Written by Cary Coutant <ccoutant@google.com>.
// This file is part of gold.
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
// MA 02110-1301, USA.
// We test that we correctly deal with weak undefined symbols.
// We need to make sure that a weak undefined symbol in the main
// program is resolved to zero by the linker and that no dynamic
// relocation is generated. We also make sure that a weak undefined
// symbol in a shared library can resolve to a symbol in the main
// program.
// This file will be linked with a shared library that does not
// define the symbol, so that the symbol remains undefined.
// Through the use of LD_LIBRARY_PATH, the program will load
// an alternate shared library that does define the symbol,
// so that we can detect whether the symbol was left for runtime
// resolution.
// Similarly, this file will be linked with a shared library that
// does define a different symbol, and loaded with an alternate
// shared library that does not define that symbol. We check that
// the weak reference remains weak, and that it is resolved to
// zero at runtime.
#include <cstdio>
#include "weak_undef.h"
extern int no_such_symbol_ __attribute__ ((weak));
extern int link_time_only __attribute__ ((weak));
int *p1 = &no_such_symbol_;
int *p2 = &link_time_only;
int v2 = 42;
int
main()
{
int status = 0;
int v;
if ((v = t1()) != 2)
{
fprintf(stderr, "FAILED weak undef test 1: %s\n",
"bound to wrong library");
status = 1;
}
if ((v = t2()) != 42)
{
fprintf(stderr, "FAILED weak undef test 2: expected %d, got %d\n",
42, v);
status = 1;
}
if ((v = t3()) != 42)
{
fprintf(stderr, "FAILED weak undef test 3: expected %d, got %d\n",
42, v);
status = 1;
}
if (&no_such_symbol_ != NULL)
{
fprintf(stderr, "FAILED weak undef test 4: %s\n",
"&no_such_symbol_ is not NULL");
status = 1;
}
if (p1 != NULL)
{
fprintf(stderr, "FAILED weak undef test 5: %s\n",
"p1 is not NULL");
status = 1;
}
if (p2 != NULL)
{
fprintf(stderr, "FAILED weak undef test 6: %s\n",
"p2 is not NULL");
status = 1;
}
return status;
}
|
