1 // weak_undef_test.cc -- test handling of weak undefined symbols for gold
2
3 // Copyright (C) 2008-2016 Free Software Foundation, Inc.
4 // Written by Cary Coutant <ccoutant@google.com>.
5
6 // This file is part of gold.
7
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
12
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
17
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
22
23 // We test that we correctly deal with weak undefined symbols.
24 // We need to make sure that a weak undefined symbol in the main
25 // program is resolved to zero by the linker and that no dynamic
26 // relocation is generated. We also make sure that a weak undefined
27 // symbol in a shared library can resolve to a symbol in the main
28 // program.
29
30 // This file will be linked with a shared library that does not
31 // define the symbol, so that the symbol remains undefined.
32 // Through the use of LD_LIBRARY_PATH, the program will load
33 // an alternate shared library that does define the symbol,
34 // so that we can detect whether the symbol was left for runtime
35 // resolution.
36
37 // Similarly, this file will be linked with a shared library that
38 // does define a different symbol, and loaded with an alternate
39 // shared library that does not define that symbol. We check that
40 // the weak reference remains weak, and that it is resolved to
41 // zero at runtime.
42
43
44 #include <cstdio>
45 #include "weak_undef.h"
46
47 extern int no_such_symbol_ __attribute__ ((weak));
48
49 extern int link_time_only __attribute__ ((weak));
50
51 int *p1 = &no_such_symbol_;
52
53 int *p2 = &link_time_only;
54
55 int v2 = 42;
56
57 int
main()58 main()
59 {
60 int status = 0;
61 int v;
62
63 if ((v = t1()) != 2)
64 {
65 fprintf(stderr, "FAILED weak undef test 1: %s\n",
66 "bound to wrong library");
67 status = 1;
68 }
69
70 if ((v = t2()) != 42)
71 {
72 fprintf(stderr, "FAILED weak undef test 2: expected %d, got %d\n",
73 42, v);
74 status = 1;
75 }
76
77 if ((v = t3()) != 42)
78 {
79 fprintf(stderr, "FAILED weak undef test 3: expected %d, got %d\n",
80 42, v);
81 status = 1;
82 }
83
84 if (&no_such_symbol_ != NULL)
85 {
86 fprintf(stderr, "FAILED weak undef test 4: %s\n",
87 "&no_such_symbol_ is not NULL");
88 status = 1;
89 }
90
91 if (p1 != NULL)
92 {
93 fprintf(stderr, "FAILED weak undef test 5: %s\n",
94 "p1 is not NULL");
95 status = 1;
96 }
97
98 if (p2 != NULL)
99 {
100 fprintf(stderr, "FAILED weak undef test 6: %s\n",
101 "p2 is not NULL");
102 status = 1;
103 }
104
105 return status;
106 }
107