Add a new library for collecting stack traces.

Supports collecting the stack trace of the current thread,
another thread in the same process, or a thread in a
different process (using ptrace).

Change-Id: Ica2594e4436edde4ceb7bcc3d78e6c31a7902cbf
diff --git a/libcorkscrew/backtrace-helper.h b/libcorkscrew/backtrace-helper.h
new file mode 100644
index 0000000..4d8a874
--- /dev/null
+++ b/libcorkscrew/backtrace-helper.h
@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) 2011 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.
+ */
+
+/* Backtrace helper functions. */
+
+#ifndef _CORKSCREW_BACKTRACE_HELPER_H
+#define _CORKSCREW_BACKTRACE_HELPER_H
+
+#include <corkscrew/backtrace.h>
+#include <sys/types.h>
+#include <stdbool.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * Add a program counter to a backtrace if it will fit.
+ * Returns the newly added frame, or NULL if none.
+ */
+backtrace_frame_t* add_backtrace_entry(uintptr_t pc,
+        backtrace_frame_t* backtrace,
+        size_t ignore_depth, size_t max_depth,
+        size_t* ignored_frames, size_t* returned_frames);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _CORKSCREW_BACKTRACE_HELPER_H