PNaCl Dynamic Linking: Added portable dependencies to shared objects.

tests/pnacl_dynamic_loading/pll_loader_test.cc

 // Copyright 2016 The Native Client Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "native_client/src/include/nacl_assert.h"
 #include "native_client/src/untrusted/pll_loader/pll_loader.h"
 
 
 namespace {
 
@@ skipping 23 matching lines @@
 
   ModuleSet modset;
   std::vector<std::string> search_path;
   search_path.push_back(module_directory);
   modset.SetSonameSearchPath(search_path);
 
   // "module_a_var" should only be resolvable after we load module A.
   int *module_a_var = (int *) modset.GetSym("module_a_var");
   ASSERT_EQ(module_a_var, NULL);
 
-  modset.AddBySoname(module_a_soname);
+  ASSERT_NE(modset.AddBySoname(module_a_soname), NULL);
   module_a_var = (int *) modset.GetSym("module_a_var");
   ASSERT_NE(module_a_var, NULL);
   ASSERT_EQ(*module_a_var, 2345);
 
-  modset.AddBySoname(module_b_soname);
+  // Demonstrate that the same soname cannot be loaded multiple times.
+  ASSERT_EQ(modset.AddBySoname(module_a_soname), NULL);
+
+  ASSERT_NE(modset.AddBySoname(module_b_soname), NULL);
   int *module_b_var = (int *) modset.GetSym("module_b_var");
   ASSERT_NE(module_b_var, NULL);
   ASSERT_EQ(*module_b_var, 1234);
 
-  modset.AddBySoname(module_tls_soname);
+  ASSERT_NE(modset.AddBySoname(module_tls_soname), NULL);
 
   modset.ResolveRefs();
 
   // Check that "addr_of_module_a_var" has been correctly relocated to
   // point to the other module.
   int **addr_of_module_a_var = (int **) modset.GetSym("addr_of_module_a_var");
   ASSERT_NE(addr_of_module_a_var, NULL);
   ASSERT_EQ(*addr_of_module_a_var, module_a_var);
 
   // Test that TLS variables are instantiated and aligned properly.
   CheckTlsVar<int>(&modset, "get_tls_var1", sizeof(int), 123);
   CheckTlsVar<int *>(&modset, "get_tls_var2", sizeof(int), module_a_var);
   CheckTlsVar<int>(&modset, "get_tls_var_aligned", 256, 345);
   CheckTlsVar<int>(&modset, "get_tls_bss_var1", sizeof(int), 0);
   CheckTlsVar<int>(&modset, "get_tls_bss_var_aligned", 256, 0);
 
   return 0;
 }