1// weak_undef_test.cc -- test handling of weak undefined symbols for gold
2
3// Copyright (C) 2008-2020 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
47extern int no_such_symbol_ __attribute__ ((weak));
48
49extern int link_time_only __attribute__ ((weak));
50
51int *p1 = &no_such_symbol_;
52
53int *p2 = &link_time_only;
54
55int v2 = 42;
56
57int
58main()
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