Create a single backtrace library.
This library will be used to abstract away getting backtrace
data from how it is implemented. This is the first step to
replacing libcorkscrew with libunwind.
Bug: 8410085
Change-Id: Ie8f159e96a055d378e1ddc72d40239fba4cf52b7
diff --git a/libbacktrace/backtrace_test.c b/libbacktrace/backtrace_test.c
new file mode 100644
index 0000000..34d3519
--- /dev/null
+++ b/libbacktrace/backtrace_test.c
@@ -0,0 +1,217 @@
+/*
+ * Copyright (C) 2013 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 <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <sys/types.h>
+#include <signal.h>
+#include <sys/ptrace.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <inttypes.h>
+
+#include <backtrace/backtrace.h>
+
+#define FINISH(pid) dump_frames(&backtrace); if (pid < 0) exit(1); else return false;
+
+// Prototypes for functions in the test library.
+int test_level_one(int, int, int, int, bool (*)(pid_t));
+
+int test_recursive_call(int, bool (*)(pid_t));
+
+void dump_frames(const backtrace_t* backtrace) {
+ for (size_t i = 0; i < backtrace->num_frames; i++) {
+ printf("%zu ", i);
+ if (backtrace->frames[i].map_name) {
+ printf("%s", backtrace->frames[i].map_name);
+ } else {
+ printf("<unknown>");
+ }
+ if (backtrace->frames[i].proc_name) {
+ printf(" %s", backtrace->frames[i].proc_name);
+ if (backtrace->frames[i].proc_offset) {
+ printf("+%" PRIuPTR, backtrace->frames[i].proc_offset);
+ }
+ }
+ printf("\n");
+ }
+}
+
+bool check_frame(const backtrace_t* backtrace, size_t frame_num,
+ const char* expected_name) {
+ if (backtrace->frames[frame_num].proc_name == NULL) {
+ printf(" Frame %zu function name expected %s, real value is NULL.\n",
+ frame_num, expected_name);
+ return false;
+ }
+ if (strcmp(backtrace->frames[frame_num].proc_name, expected_name) != 0) {
+ printf(" Frame %zu function name expected %s, real value is %s.\n",
+ frame_num, expected_name, backtrace->frames[frame_num].proc_name);
+ return false;
+ }
+ return true;
+}
+
+bool verify_level_backtrace(pid_t pid) {
+ const char* test_type;
+ if (pid < 0) {
+ test_type = "current";
+ } else {
+ test_type = "running";
+ }
+
+ backtrace_t backtrace;
+ if (!backtrace_get_data(&backtrace, pid)) {
+ printf(" backtrace_get_data failed on %s process.\n", test_type);
+ FINISH(pid);
+ }
+
+ if (backtrace.num_frames == 0) {
+ printf(" backtrace_get_data returned no frames for %s process.\n",
+ test_type);
+ FINISH(pid);
+ }
+
+ // Look through the frames starting at the highest to find the
+ // frame we want.
+ size_t frame_num = 0;
+ for (size_t i = backtrace.num_frames-1; i > 2; i--) {
+ if (backtrace.frames[i].proc_name != NULL &&
+ strcmp(backtrace.frames[i].proc_name, "test_level_one") == 0) {
+ frame_num = i;
+ break;
+ }
+ }
+ if (!frame_num) {
+ printf(" backtrace_get_data did not include the test_level_one frame.\n");
+ FINISH(pid);
+ }
+
+ if (!check_frame(&backtrace, frame_num, "test_level_one")) {
+ FINISH(pid);
+ }
+ if (!check_frame(&backtrace, frame_num-1, "test_level_two")) {
+ FINISH(pid);
+ }
+ if (!check_frame(&backtrace, frame_num-2, "test_level_three")) {
+ FINISH(pid);
+ }
+ if (!check_frame(&backtrace, frame_num-3, "test_level_four")) {
+ FINISH(pid);
+ }
+ backtrace_free_data(&backtrace);
+
+ return true;
+}
+
+bool verify_max_backtrace(pid_t pid) {
+ const char* test_type;
+ if (pid < 0) {
+ test_type = "current";
+ } else {
+ test_type = "running";
+ }
+
+ backtrace_t backtrace;
+ if (!backtrace_get_data(&backtrace, pid)) {
+ printf(" backtrace_get_data failed on %s process.\n", test_type);
+ FINISH(pid);
+ }
+
+ if (backtrace.num_frames != MAX_BACKTRACE_FRAMES) {
+ printf(" backtrace_get_data %s process max frame check failed:\n",
+ test_type);
+ printf(" Expected num frames to be %zu, found %zu\n",
+ MAX_BACKTRACE_FRAMES, backtrace.num_frames);
+ FINISH(pid);
+ }
+ backtrace_free_data(&backtrace);
+
+ return true;
+}
+
+void verify_proc_test(pid_t pid, bool (*verify_func)(pid_t)) {
+ printf(" Waiting 5 seconds for process to get to infinite loop.\n");
+ sleep(5);
+ if (ptrace(PTRACE_ATTACH, pid, 0, 0) < 0) {
+ printf("Failed to attach to pid %d\n", pid);
+ kill(pid, SIGKILL);
+ exit(1);
+ }
+ bool pass = verify_func(pid);
+ if (ptrace(PTRACE_DETACH, pid, 0, 0) != 0) {
+ printf("Failed to detach from pid %d\n", pid);
+ kill(pid, SIGKILL);
+ exit(1);
+ }
+
+ kill(pid, SIGKILL);
+ int status;
+ if (waitpid(pid, &status, 0) != pid) {
+ printf("Forked process did not terminate properly.\n");
+ exit(1);
+ }
+
+ if (!pass) {
+ exit(1);
+ }
+}
+
+int main() {
+ printf("Running level test on current process...\n");
+ int value = test_level_one(1, 2, 3, 4, verify_level_backtrace);
+ if (value == 0) {
+ printf("This should never happen.\n");
+ exit(1);
+ }
+ printf(" Passed.\n");
+
+ printf("Running max level test on current process...\n");
+ value = test_recursive_call(MAX_BACKTRACE_FRAMES+10, verify_max_backtrace);
+ if (value == 0) {
+ printf("This should never happen.\n");
+ exit(1);
+ }
+ printf(" Passed.\n");
+
+ printf("Running level test on process...\n");
+ pid_t pid;
+ if ((pid = fork()) == 0) {
+ value = test_level_one(1, 2, 3, 4, NULL);
+ if (value == 0) {
+ printf("This should never happen.\n");
+ }
+ exit(1);
+ }
+ verify_proc_test(pid, verify_level_backtrace);
+ printf(" Passed.\n");
+
+ printf("Running max frame test on process...\n");
+ if ((pid = fork()) == 0) {
+ value = test_recursive_call(MAX_BACKTRACE_FRAMES+10, NULL);
+ if (value == 0) {
+ printf("This should never happen.\n");
+ }
+ exit(1);
+ }
+ verify_proc_test(pid, verify_max_backtrace);
+ printf(" Passed.\n");
+
+ printf("All tests passed.\n");
+ return 0;
+}