1 // weak_undef_file2.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 the symbol is resolved to zero
25 // by the linker and that no dynamic relocation is generated.
26
27 // This source is used to build a shared library that defines
28 // the weak undefined symbol referenced by the main program.
29 // The main program will be linked with a library that does not
30 // provide this definition, so that the symbol remains undefined.
31 // Through the use of the embedded RPATH, the program will load
32 // this alternate shared library that does define the symbol,
33 // so that we can detect whether the symbol was left for runtime
34 // resolution.
35
36
37 #include <cstdio>
38
39 #include "weak_undef.h"
40
41 int is_such_symbol_ = 1;
42 int no_such_symbol_ = 2;
43
44 extern int v2 __attribute__ ((weak));
45
46 int *v3 = &v2;
47
48 int
t1()49 t1()
50 {
51 return no_such_symbol_;
52 }
53
54 // Test that a weak reference from a shared library to a symbol
55 // defined in the main program does get resolved.
56
57 int
t2()58 t2()
59 {
60 return (&v2 == NULL) ? -1 : v2;
61 }
62
63 // Test that a weak reference from a shared library to a symbol
64 // defined in the main program does get resolved.
65
66 int
t3()67 t3()
68 {
69 return (v3 == NULL) ? -1 : *v3;
70 }
71