llvm-project/compiler-rt/lib/builtins/unwind-ehabi-helpers.h

/* ===-- arm-ehabi-helpers.h - Supplementary ARM EHABI declarations --------===
 *
 * Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 * See https://llvm.org/LICENSE.txt for license information.
 * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 *
 * ===--------------------------------------------------------------------=== */

#ifndef UNWIND_EHABI_HELPERS_H
#define UNWIND_EHABI_HELPERS_H

#include <stdint.h>
/* NOTE: see reasoning for this inclusion below */
#include <unwind.h>

#if !defined(__ARM_EABI_UNWINDER__)

/*
 * NOTE: _URC_OK, _URC_FAILURE must be present as preprocessor tokens.  This
 * allows for a substitution of a constant which can be cast into the
 * appropriate enumerated type.  This header is expected to always be included
 * AFTER unwind.h (which is why it is forcefully included above).  This ensures
 * that we do not overwrite the token for the enumeration.  Subsequent uses of
 * the token would be clean to rewrite with constant values.
 *
 * The typedef redeclaration should be safe.  Due to the protection granted to
 * us by the `__ARM_EABI_UNWINDER__` above, we are guaranteed that we are in a
 * header not vended by gcc.  The HP unwinder (being an itanium unwinder) does
 * not support EHABI, and the GNU unwinder, derived from the HP unwinder, also
 * does not support EHABI as of the introduction of this header.  As such, we
 * are fairly certain that we are in the LLVM case.  Here, _Unwind_State is a
 * typedef, and so we can get away with a redeclaration.
 *
 * Guarded redefinitions of the needed unwind state prevent the redefinition of
 * those states.
 */

#define _URC_OK       0
#define _URC_FAILURE  9

typedef uint32_t _Unwind_State;

#if !defined(_US_UNWIND_FRAME_STARTING)
#define _US_UNWIND_FRAME_STARTING ((_Unwind_State)1)
#endif

#if !defined(_US_ACTION_MASK)
#define _US_ACTION_MASK ((_Unwind_State)3)
#endif

#endif

#endif