Load libraries in breadth-first order

  This patch fixes the problem with symbol search order
  for dlsym(RTLD_DEFAULT/RTLD_NEXT, .) by loading libraries
  and ld_preloads in correct order.

Bug: https://code.google.com/p/android/issues/detail?id=74255
Change-Id: I4cf84c70dbaabe99310230dfda12385ae5401859

2 files changed, 179 insertions, 0 deletions

diff --git a/tests/libs/Android.mk b/tests/libs/Android.mk
index b1cc836..2ceb15b 100644
--- a/tests/libs/Android.mk
+++ b/tests/libs/Android.mk
@@ -103,6 +103,160 @@ build_target := SHARED_LIBRARY
 include $(TEST_PATH)/Android.build.mk
 
 # -----------------------------------------------------------------------------
+# Libraries used by dlfcn tests to verify correct load order:
+# libtest_check_order_2_right.so
+# -----------------------------------------------------------------------------
+libtest_check_order_2_right_src_files := \
+    dlopen_testlib_answer.cpp
+
+libtest_check_order_2_right_cflags := -D__ANSWER=42
+module := libtest_check_order_2_right
+build_type := target
+build_target := SHARED_LIBRARY
+include $(TEST_PATH)/Android.build.mk
+
+# -----------------------------------------------------------------------------
+# libtest_check_order_a.so
+# -----------------------------------------------------------------------------
+libtest_check_order_a_src_files := \
+    dlopen_testlib_answer.cpp
+
+libtest_check_order_a_cflags := -D__ANSWER=1
+module := libtest_check_order_a
+build_type := target
+build_target := SHARED_LIBRARY
+include $(TEST_PATH)/Android.build.mk
+
+# -----------------------------------------------------------------------------
+# libtest_check_order_b.so
+# -----------------------------------------------------------------------------
+libtest_check_order_b_src_files := \
+    dlopen_testlib_answer.cpp
+
+libtest_check_order_b_cflags := -D__ANSWER=2 -D__ANSWER2=43
+module := libtest_check_order_b
+build_type := target
+build_target := SHARED_LIBRARY
+include $(TEST_PATH)/Android.build.mk
+
+# -----------------------------------------------------------------------------
+# libtest_check_order_c.so
+# -----------------------------------------------------------------------------
+libtest_check_order_3_c_src_files := \
+    dlopen_testlib_answer.cpp
+
+libtest_check_order_3_c_cflags := -D__ANSWER=3
+module := libtest_check_order_3_c
+build_type := target
+build_target := SHARED_LIBRARY
+include $(TEST_PATH)/Android.build.mk
+
+# -----------------------------------------------------------------------------
+# libtest_check_order_d.so
+# -----------------------------------------------------------------------------
+libtest_check_order_d_src_files := \
+   dlopen_testlib_answer.cpp
+
+libtest_check_order_d_shared_libraries := libtest_check_order_b
+libtest_check_order_d_cflags := -D__ANSWER=4 -D__ANSWER2=4
+module := libtest_check_order_d
+build_type := target
+build_target := SHARED_LIBRARY
+include $(TEST_PATH)/Android.build.mk
+
+# -----------------------------------------------------------------------------
+# libtest_check_order_left.so
+# -----------------------------------------------------------------------------
+libtest_check_order_1_left_src_files := \
+    empty.cpp
+
+libtest_check_order_1_left_shared_libraries := libtest_check_order_a libtest_check_order_b
+
+module := libtest_check_order_1_left
+build_type := target
+build_target := SHARED_LIBRARY
+include $(TEST_PATH)/Android.build.mk
+
+# -----------------------------------------------------------------------------
+# libtest_check_order.so
+# -----------------------------------------------------------------------------
+libtest_check_order_src_files := \
+    empty.cpp
+
+libtest_check_order_shared_libraries := libtest_check_order_1_left \
+  libtest_check_order_2_right libtest_check_order_3_c
+
+module := libtest_check_order
+build_type := target
+build_target := SHARED_LIBRARY
+include $(TEST_PATH)/Android.build.mk
+
+# -----------------------------------------------------------------------------
+# Library with dependency loop used by dlfcn tests
+#
+# libtest_with_dependency_loop -> a -> b -> c -> a
+# -----------------------------------------------------------------------------
+libtest_with_dependency_loop_src_files := empty.cpp
+
+libtest_with_dependency_loop_shared_libraries := \
+    libtest_with_dependency_loop_a
+
+module := libtest_with_dependency_loop
+build_type := target
+build_target := SHARED_LIBRARY
+include $(TEST_PATH)/Android.build.mk
+
+# -----------------------------------------------------------------------------
+# libtest_with_dependency_loop_a.so
+# -----------------------------------------------------------------------------
+libtest_with_dependency_loop_a_src_files := empty.cpp
+
+libtest_with_dependency_loop_a_shared_libraries := \
+    libtest_with_dependency_loop_b_tmp
+
+module := libtest_with_dependency_loop_a
+build_type := target
+build_target := SHARED_LIBRARY
+include $(TEST_PATH)/Android.build.mk
+
+# -----------------------------------------------------------------------------
+# libtest_with_dependency_loop_b.so
+#
+# this is temporary placeholder - will be removed
+# -----------------------------------------------------------------------------
+libtest_with_dependency_loop_b_tmp_src_files := empty.cpp
+libtest_with_dependency_loop_b_tmp_ldflags := -Wl,-soname=libtest_with_dependency_loop_b.so
+
+module := libtest_with_dependency_loop_b_tmp
+build_type := target
+build_target := SHARED_LIBRARY
+include $(TEST_PATH)/Android.build.mk
+
+# -----------------------------------------------------------------------------
+# libtest_with_dependency_loop_b.so
+# -----------------------------------------------------------------------------
+libtest_with_dependency_loop_b_src_files := empty.cpp
+libtest_with_dependency_loop_b_shared_libraries := libtest_with_dependency_loop_c
+
+module := libtest_with_dependency_loop_b
+build_type := target
+build_target := SHARED_LIBRARY
+include $(TEST_PATH)/Android.build.mk
+
+# -----------------------------------------------------------------------------
+# libtest_with_dependency_loop_c.so
+# -----------------------------------------------------------------------------
+libtest_with_dependency_loop_c_src_files := empty.cpp
+
+libtest_with_dependency_loop_c_shared_libraries := \
+    libtest_with_dependency_loop_a
+
+module := libtest_with_dependency_loop_c
+build_type := target
+build_target := SHARED_LIBRARY
+include $(TEST_PATH)/Android.build.mk
+
+# -----------------------------------------------------------------------------
 # Library with dependency used by dlfcn tests
 # -----------------------------------------------------------------------------
 libtest_with_dependency_src_files := \
diff --git a/tests/libs/dlopen_testlib_answer.cpp b/tests/libs/dlopen_testlib_answer.cpp
new file mode 100644
index 0000000..a4d7504
--- /dev/null
+++ b/tests/libs/dlopen_testlib_answer.cpp
@@ -0,0 +1,25 @@
+/*
+ * Copyright (C) 2014 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.
+ */
+
+extern "C" int dlopen_test_get_answer() {
+  return __ANSWER;
+}
+
+#ifdef __ANSWER2
+extern "C" int dlopen_test_get_answer2() {
+  return __ANSWER2;
+}
+#endif