esp-idf/components/esp_system/include/libunwind.h

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/*
* SPDX-FileCopyrightText: 2020-2022 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
#ifndef LIBUNWIND_H
#define LIBUNWIND_H
#include "sdkconfig.h"
#include <stddef.h>
#include <stdint.h>
#if CONFIG_IDF_TARGET_ARCH_RISCV
#include "libunwind-riscv.h"
#elif CONFIG_IDF_TARGET_X86
#include "libunwind-x86.h"
#else
/* This header must be a standalone one, so, it shall not trigger an error when
* pre-processed without including any of the architecture header above.
* The implementation can trigger a compile error if UNW_UNKNOWN_TARGET
* macro is defined. */
#define UNW_UNKNOWN_TARGET 1
typedef void* ExecutionFrame;
#endif
#ifdef __cplusplus
extern "C" {
#endif
/* Error codes returned by the functions defined below */
#define UNW_ESUCCESS 0
#define UNW_EUNSPEC 1 /* General failure */
#define UNW_EBADREG 3 /* Register given is wrong */
#define UNW_ESTOPUNWIND 5
#define UNW_EINVAL 8 /* Bad parameter or unimplemented operation */
#define UNW_EBADVERSION 9
#define UNW_ENOINFO 10
/* A libunwind context is the equivalent of an ESP-IDF ExecutionFrame */
typedef ExecutionFrame unw_context_t;
/* A register number is an unsigned word in our case */
typedef uint32_t unw_regnum_t;
/* In our current implementation, a cursor is the same as a context */
typedef unw_context_t unw_cursor_t;
/* long should represent the size of a CPU register */
typedef unsigned long unw_word_t;
/* At the moment, we don't support the operations using the following types,
* so just set them to void* */
typedef void* unw_addr_space_t;
typedef void* unw_fpreg_t;
/**
* @brief Get the current CPU context.
*
* @param[out] ctx Pointer to `unw_context_t` structure. It must not be NULL
* as it will be filled with the CPU registers value
*
* @return UNW_ESUCCESS on success, -UNW_EUNSPEC if ctx is NULL
*
* @note This function MUST be inlined. Marking it as "static inline" or
* __attribute__((always_inline)) does not guarantee that it will inlined by
* the compiler for all the architectures. Thus, define this function as a macro.
* @note If the caller of this function returns, all the pointers, contexts, cursors
* generated out of the initial returned context shall be considered invalid and
* thus, must **not** be used.
*/
#define unw_getcontext(ctx) ({ int retval; \
if (ctx == NULL) { \
retval = -UNW_EUNSPEC; \
} else { \
UNW_GET_CONTEXT(ctx); \
retval = UNW_ESUCCESS; \
} \
retval; \
})
/**
* @brief Initialize a cursor on a local context. Multiple cursor can be initialized on
* a given CPU context, they can then be manipulated independently.
*
* @param[out] c Pointer on cursor to be returned. Must not be NULL
* @param[in] ctx Pointer on the context returned by the function `unw_getcontext`
*
* @return UNW_ESUCCESS on success, -UNW_EUNSPEC if one of the parameter is NULL.
*/
int unw_init_local(unw_cursor_t* c, unw_context_t* ctx);
/**
* @brief Perform a step "up" on the given cursor. After calling this function, the
* cursor will point to the caller's CPU context. Thus, it is then possible
* to retrieve the caller's address by getting the PC register out of the cursor.
* Check `unw_get_reg` function for this.
*
* @param[in] cp Current cursor
*
* @returns 0 if the previous frame was the last one
* @returns Positive value on success
* @returns -UNW_EBADVERSION if the DWARF information's version is not compatible with the eh_frame_parser implementation
* @returns -UNW_ENOINFO if the caller information are not present in the binary. (if the caller is in ROM for example)
* @returns -UNW_ESTOPUNWIND if unwinding is terminated
*/
int unw_step(unw_cursor_t* cp);
/**
* @brief Get the value of a CPU register from a given cursor.
*
* @param[in] cp Pointer to the cursor
* @param reg Register number to retrieve the value of
* @param[out] valp Pointer that will be filled with the register value
*
* @returns UNW_ESUCCESS on success
* @returns -UNW_EUNSPEC if any pointer passed is NULL
* @returns -UNW_EBADREG if the register number is invalid
*/
int unw_get_reg(unw_cursor_t* cp, unw_regnum_t reg, unw_word_t* valp);
/**
* @brief Set the value of a CPU register in a given cursor.
*
* @param[in]cp Pointer to the cursor
* @param reg Register number to set the value of
* @param val New register value
*
* @returns UNW_ESUCCESS on success
* @returns -UNW_EUNSPEC if the pointer passed is NULL
* @returns -UNW_EBADREG if the register number is invalid
*/
int unw_set_reg(unw_cursor_t* cp, unw_regnum_t reg, unw_word_t val);
#endif // LIBUNWIND_H