1 // weak_undef_file1.cc -- test handling of weak undefined symbols for gold
2
3 // Copyright (C) 2008-2014 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 // an arbitrary symbol other than the weak undefined symbol
29 // referenced by the main program. The main program will be
30 // linked with this library so that the symbol remains undefined.
31 // Through the use of the embedded RPATH, the program will load
32 // an 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 #include <cstdio>
37
38 #include "weak_undef.h"
39
40 int is_such_symbol_ = 1;
41
42 // We also define a symbol that is not defined by the alternate
43 // library. The main program contains a weak reference to this
44 // symbol, and tests that the reference remains weak even after
45 // the definition was found at link time.
46
47 int link_time_only = 1;
48
49 extern int v2 __attribute__ ((weak));
50
51 int *v3 = &v2;
52
53 int
t1()54 t1()
55 {
56 return is_such_symbol_;
57 }
58
59 // Test that a weak reference from a shared library to a symbol
60 // defined in the main program does get resolved.
61
62 int
t2()63 t2()
64 {
65 return (&v2 == NULL) ? -1 : v2;
66 }
67
68 // Test that a weak reference from a shared library to a symbol
69 // defined in the main program does get resolved.
70
71 int
t3()72 t3()
73 {
74 return (v3 == NULL) ? -1 : *v3;
75 }
76