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 <pthread.h>
 
 #include "native_client/src/include/nacl_assert.h"
 #include "native_client/src/untrusted/pll_loader/pll_loader.h"
 
 
@@ skipping 39 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.
@@ skipping 12 matching lines @@
   int err = pthread_create(&tid, NULL, ThreadFunc, &thread_args);
   ASSERT_EQ(err, 0);
   err = pthread_join(tid, NULL);
   ASSERT_EQ(err, 0);
   // Check that the TLS var is still given the same address.  This
   // should not have been affected by launching a child thread.
   ASSERT_EQ(thread_args.tls_var_getter(), thread_args.tls_var_on_main_thread);
 
   return 0;
 }