Add support for the new unwind method.
Also add a comment to the GetElf function to indicate that it never returns
nullptr.
Also needed to add this library to the a million and one places that the vndk
has hard-coded this data.
Bug: 23762183
Test: Built, nothing uses the new code.
Test: However, I did run backtrace_test using this code, and all tests pass.
Change-Id: Ib270665dcb7a7607075e36d88be76dbde6e2faa8
(cherry picked from commit dc4104b720c7fd2014ccfa9fa621d02df58a43c4)
diff --git a/libbacktrace/UnwindStackMap.h b/libbacktrace/UnwindStackMap.h
new file mode 100644
index 0000000..7885b74
--- /dev/null
+++ b/libbacktrace/UnwindStackMap.h
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2017 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.
+ */
+
+#ifndef _LIBBACKTRACE_UNWINDSTACK_MAP_H
+#define _LIBBACKTRACE_UNWINDSTACK_MAP_H
+
+#include <stdint.h>
+#include <sys/types.h>
+
+#include <backtrace/BacktraceMap.h>
+#include <unwindstack/Maps.h>
+
+class UnwindStackMap : public BacktraceMap {
+ public:
+ explicit UnwindStackMap(pid_t pid);
+ ~UnwindStackMap() = default;
+
+ bool Build() override;
+
+ void FillIn(uintptr_t addr, backtrace_map_t* map) override;
+
+ unwindstack::Maps* stack_maps() { return stack_maps_.get(); }
+
+ protected:
+ std::unique_ptr<unwindstack::Maps> stack_maps_;
+};
+
+#endif // _LIBBACKTRACE_UNWINDSTACK_MAP_H