Improved dlsym tests and fixes to linker

 Answers the question: what if dependent library
 was preloaded with RTLD_LOCAL flag.

 Also add test for RTLD_NEXT within local_group.

Bug: http://b/17512583
Change-Id: I79e081e68b3a8c0ed8980d4275a06515fea94ec9
diff --git a/tests/dlfcn_test.cpp b/tests/dlfcn_test.cpp
index 6b1f109..a5abda7 100644
--- a/tests/dlfcn_test.cpp
+++ b/tests/dlfcn_test.cpp
@@ -71,23 +71,80 @@
   void* handle = dlopen("libtest_dlsym_from_this.so", RTLD_LAZY | RTLD_LOCAL);
   ASSERT_TRUE(handle != nullptr) << dlerror();
 
-  // check that we cant find '_test_dlsym_symbol' via dlsym(RTLD_DEFAULT)
+  // check that we can't find '_test_dlsym_symbol' via dlsym(RTLD_DEFAULT)
   void* symbol = dlsym(RTLD_DEFAULT, "test_dlsym_symbol");
   ASSERT_TRUE(symbol == nullptr);
   ASSERT_SUBSTR("undefined symbol: test_dlsym_symbol", dlerror());
 
   typedef int* (*fn_t)();
-  fn_t fn = reinterpret_cast<fn_t>(dlsym(handle, "lookup_dlsym_symbol_using_RTLD_DEFAULT"));
+  fn_t lookup_dlsym_symbol_using_RTLD_DEFAULT =
+      reinterpret_cast<fn_t>(dlsym(handle, "lookup_dlsym_symbol_using_RTLD_DEFAULT"));
+  ASSERT_TRUE(lookup_dlsym_symbol_using_RTLD_DEFAULT != nullptr) << dlerror();
 
-  ASSERT_TRUE(fn != nullptr) << dlerror();
-
-  int* ptr = fn();
+  int* ptr = lookup_dlsym_symbol_using_RTLD_DEFAULT();
   ASSERT_TRUE(ptr != nullptr) << dlerror();
   ASSERT_EQ(42, *ptr);
 
+  fn_t lookup_dlsym_symbol2_using_RTLD_DEFAULT =
+      reinterpret_cast<fn_t>(dlsym(handle, "lookup_dlsym_symbol2_using_RTLD_DEFAULT"));
+  ASSERT_TRUE(lookup_dlsym_symbol2_using_RTLD_DEFAULT != nullptr) << dlerror();
+
+  ptr = lookup_dlsym_symbol2_using_RTLD_DEFAULT();
+  ASSERT_TRUE(ptr != nullptr) << dlerror();
+  ASSERT_EQ(44, *ptr);
+
+  fn_t lookup_dlsym_symbol_using_RTLD_NEXT =
+      reinterpret_cast<fn_t>(dlsym(handle, "lookup_dlsym_symbol_using_RTLD_NEXT"));
+  ASSERT_TRUE(lookup_dlsym_symbol_using_RTLD_NEXT != nullptr) << dlerror();
+
+  ptr = lookup_dlsym_symbol_using_RTLD_NEXT();
+  ASSERT_TRUE(ptr != nullptr) << dlerror();
+  ASSERT_EQ(43, *ptr);
+
   dlclose(handle);
 }
 
+TEST(dlfcn, dlsym_from_sofile_with_preload) {
+  void* preload = dlopen("libtest_dlsym_from_this_grandchild.so", RTLD_NOW | RTLD_LOCAL);
+  ASSERT_TRUE(preload != nullptr) << dlerror();
+
+  void* handle = dlopen("libtest_dlsym_from_this.so", RTLD_NOW | RTLD_LOCAL);
+  ASSERT_TRUE(handle != nullptr) << dlerror();
+
+  // check that we can't find '_test_dlsym_symbol' via dlsym(RTLD_DEFAULT)
+  void* symbol = dlsym(RTLD_DEFAULT, "test_dlsym_symbol");
+  ASSERT_TRUE(symbol == nullptr);
+  ASSERT_SUBSTR("undefined symbol: test_dlsym_symbol", dlerror());
+
+  typedef int* (*fn_t)();
+  fn_t lookup_dlsym_symbol_using_RTLD_DEFAULT =
+      reinterpret_cast<fn_t>(dlsym(handle, "lookup_dlsym_symbol_using_RTLD_DEFAULT"));
+  ASSERT_TRUE(lookup_dlsym_symbol_using_RTLD_DEFAULT != nullptr) << dlerror();
+
+  int* ptr = lookup_dlsym_symbol_using_RTLD_DEFAULT();
+  ASSERT_TRUE(ptr != nullptr) << dlerror();
+  ASSERT_EQ(42, *ptr);
+
+  fn_t lookup_dlsym_symbol2_using_RTLD_DEFAULT =
+      reinterpret_cast<fn_t>(dlsym(handle, "lookup_dlsym_symbol2_using_RTLD_DEFAULT"));
+  ASSERT_TRUE(lookup_dlsym_symbol2_using_RTLD_DEFAULT != nullptr) << dlerror();
+
+  ptr = lookup_dlsym_symbol2_using_RTLD_DEFAULT();
+  ASSERT_TRUE(ptr != nullptr) << dlerror();
+  ASSERT_EQ(44, *ptr);
+
+  fn_t lookup_dlsym_symbol_using_RTLD_NEXT =
+      reinterpret_cast<fn_t>(dlsym(handle, "lookup_dlsym_symbol_using_RTLD_NEXT"));
+  ASSERT_TRUE(lookup_dlsym_symbol_using_RTLD_NEXT != nullptr) << dlerror();
+
+  ptr = lookup_dlsym_symbol_using_RTLD_NEXT();
+  ASSERT_TRUE(ptr != nullptr) << dlerror();
+  ASSERT_EQ(43, *ptr);
+
+  dlclose(handle);
+  dlclose(preload);
+}
+
 TEST(dlfcn, dlsym_with_dependencies) {
   void* handle = dlopen("libtest_with_dependency.so", RTLD_NOW);
   ASSERT_TRUE(handle != NULL);
diff --git a/tests/libs/Android.mk b/tests/libs/Android.mk
index c432c2e..4e275ed 100644
--- a/tests/libs/Android.mk
+++ b/tests/libs/Android.mk
@@ -385,11 +385,26 @@
 # -----------------------------------------------------------------------------
 # Library to check RTLD_LOCAL with dlsym in 'this'
 # -----------------------------------------------------------------------------
-libtest_dlsym_from_this_src_files := dlsym_from_this.cpp
+libtest_dlsym_from_this_src_files := dlsym_from_this_symbol.cpp
+
+libtest_dlsym_from_this_shared_libraries_target := libdl
+libtest_dlsym_from_this_shared_libraries := libtest_dlsym_from_this_child
 
 module := libtest_dlsym_from_this
-libtest_dlsym_from_this_shared_libraries_target := libdl
+include $(LOCAL_PATH)/Android.build.testlib.mk
 
+# -----------------------------------------------------------------------------
+libtest_dlsym_from_this_child_src_files := dlsym_from_this_functions.cpp
+
+libtest_dlsym_from_this_child_shared_libraries := libtest_dlsym_from_this_grandchild
+
+module := libtest_dlsym_from_this_child
+include $(LOCAL_PATH)/Android.build.testlib.mk
+
+# -----------------------------------------------------------------------------
+libtest_dlsym_from_this_grandchild_src_files := dlsym_from_this_symbol2.cpp
+
+module := libtest_dlsym_from_this_grandchild
 include $(LOCAL_PATH)/Android.build.testlib.mk
 
 # -----------------------------------------------------------------------------
diff --git a/tests/libs/dlsym_from_this_functions.cpp b/tests/libs/dlsym_from_this_functions.cpp
new file mode 100644
index 0000000..1f357e0
--- /dev/null
+++ b/tests/libs/dlsym_from_this_functions.cpp
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include <dlfcn.h>
+#include <stdio.h>
+
+extern int test_dlsym_symbol;
+
+int test_dlsym_symbol = -1;
+
+extern "C" int* lookup_dlsym_symbol_using_RTLD_DEFAULT() {
+  dlerror();
+  int* result = static_cast<int*>(dlsym(RTLD_DEFAULT, "test_dlsym_symbol"));
+  // TODO: remove this once b/20049306 is fixed
+  if (result == nullptr) {
+    printf("Cannot find the answer\n");
+  }
+  return result;
+}
+
+extern "C" int* lookup_dlsym_symbol2_using_RTLD_DEFAULT() {
+  dlerror();
+  int* result = static_cast<int*>(dlsym(RTLD_DEFAULT, "test_dlsym_symbol2"));
+  // TODO: remove this once b/20049306 is fixed
+  if (result == nullptr) {
+    printf("Cannot find the answer\n");
+  }
+  return result;
+}
+
+extern "C" int* lookup_dlsym_symbol_using_RTLD_NEXT() {
+  dlerror();
+  int* result = static_cast<int*>(dlsym(RTLD_NEXT, "test_dlsym_symbol"));
+  // TODO: remove this once b/20049306 is fixed
+  if (result == nullptr) {
+    printf("Cannot find the answer\n");
+  }
+  return result;
+}
+
diff --git a/tests/libs/dlsym_from_this.cpp b/tests/libs/dlsym_from_this_symbol.cpp
similarity index 60%
rename from tests/libs/dlsym_from_this.cpp
rename to tests/libs/dlsym_from_this_symbol.cpp
index b5215c9..c3ec255 100644
--- a/tests/libs/dlsym_from_this.cpp
+++ b/tests/libs/dlsym_from_this_symbol.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2014 The Android Open Source Project
+ * Copyright (C) 2015 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -13,18 +13,5 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-#include <dlfcn.h>
-#include <stdio.h>
 
 int test_dlsym_symbol = 42;
-
-extern "C" int* lookup_dlsym_symbol_using_RTLD_DEFAULT() {
-  dlerror();
-  int* result = static_cast<int*>(dlsym(RTLD_DEFAULT, "test_dlsym_symbol"));
-  // TODO: remove this once b/20049306 is fixed
-  if (result == nullptr) {
-    printf("Cannot find the answer\n");
-  }
-  return result;
-}
-
diff --git a/tests/libs/dlsym_from_this_symbol2.cpp b/tests/libs/dlsym_from_this_symbol2.cpp
new file mode 100644
index 0000000..20da1d5
--- /dev/null
+++ b/tests/libs/dlsym_from_this_symbol2.cpp
@@ -0,0 +1,18 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+int test_dlsym_symbol = 43;
+int test_dlsym_symbol2 = 44;