gold/testsuite/weak_undef_test.cc

   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
  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
  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 }