/*

 * 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.

 */

/* A stack unwinder. */

#ifndef _CORKSCREW_BACKTRACE_H

#define _CORKSCREW_BACKTRACE_H

#ifdef __cplusplus

extern "C" {

#endif

#include <sys/types.h>

#include <corkscrew/ptrace.h>

#include <corkscrew/map_info.h>

#include <corkscrew/symbol_table.h>

	/*

	 * Describes a single frame of a backtrace.

	 */

	typedef struct

	{

		uintptr_t absolute_pc;     /* absolute PC offset */

		uintptr_t stack_top;       /* top of stack for this frame */

		size_t stack_size;         /* size of this stack frame */

	} backtrace_frame_t;

	/*

	 * Describes the symbols associated with a backtrace frame.

	 */

	typedef struct

	{

		uintptr_t relative_pc;       /* relative frame PC offset from the start of the library,

                                    or the absolute PC if the library is unknown */

		uintptr_t relative_symbol_addr; /* relative offset of the symbol from the start of the

                                    library or 0 if the library is unknown */

		char *map_name;              /* executable or library name, or NULL if unknown */

		char *symbol_name;           /* symbol name, or NULL if unknown */

		char *demangled_name;        /* demangled symbol name, or NULL if unknown */

	} backtrace_symbol_t;

	/*

	 * Unwinds the call stack for the current thread of execution.

	 * Populates the backtrace array with the program counters from the call stack.

	 * Returns the number of frames collected, or -1 if an error occurred.

	 */

	ssize_t unwind_backtrace(backtrace_frame_t *backtrace, size_t ignore_depth, size_t max_depth);

	/*

	 * Unwinds the call stack for a thread within this process.

	 * Populates the backtrace array with the program counters from the call stack.

	 * Returns the number of frames collected, or -1 if an error occurred.

	 *

	 * The task is briefly suspended while the backtrace is being collected.

	 */

	ssize_t unwind_backtrace_thread(pid_t tid, backtrace_frame_t *backtrace,

									size_t ignore_depth, size_t max_depth);

	/*

	 * Unwinds the call stack of a task within a remote process using ptrace().

	 * Populates the backtrace array with the program counters from the call stack.

	 * Returns the number of frames collected, or -1 if an error occurred.

	 */

	ssize_t unwind_backtrace_ptrace(pid_t tid, const ptrace_context_t *context,

									backtrace_frame_t *backtrace, size_t ignore_depth, size_t max_depth);

	/*

	 * Gets the symbols for each frame of a backtrace.

	 * The symbols array must be big enough to hold one symbol record per frame.

	 * The symbols must later be freed using free_backtrace_symbols.

	 */

	void get_backtrace_symbols(const backtrace_frame_t *backtrace, size_t frames,

							   backtrace_symbol_t *backtrace_symbols);

	/*

	 * Gets the symbols for each frame of a backtrace from a remote process.

	 * The symbols array must be big enough to hold one symbol record per frame.

	 * The symbols must later be freed using free_backtrace_symbols.

	 */

	void get_backtrace_symbols_ptrace(const ptrace_context_t *context,

									  const backtrace_frame_t *backtrace, size_t frames,

									  backtrace_symbol_t *backtrace_symbols);

	/*

	 * Frees the storage associated with backtrace symbols.

	 */

	void free_backtrace_symbols(backtrace_symbol_t *backtrace_symbols, size_t frames);

	enum

	{

		// A hint for how big to make the line buffer for format_backtrace_line

		MAX_BACKTRACE_LINE_LENGTH = 800,

	};

	/**

	 * Formats a line from a backtrace as a zero-terminated string into the specified buffer.

	 */

	void format_backtrace_line(unsigned frameNumber, const backtrace_frame_t *frame,

							   const backtrace_symbol_t *symbol, char *buffer, size_t bufferSize);

#ifdef __cplusplus

}

#endif

#endif // _CORKSCREW_BACKTRACE_H