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

   1 //===-- arm-ehabi-helpers.h - Supplementary ARM EHABI declarations --------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===--------------------------------------------------------------------===//
   8
   9 #ifndef UNWIND_EHABI_HELPERS_H
  10 #define UNWIND_EHABI_HELPERS_H
  11
  12 #include <stdint.h>
  13 // NOTE: see reasoning for this inclusion below
  14 #include <unwind.h>
  15
  16 #if !defined(__ARM_EABI_UNWINDER__)
  17
  18 // NOTE: _URC_OK, _URC_FAILURE must be present as preprocessor tokens.  This
  19 // allows for a substitution of a constant which can be cast into the
  20 // appropriate enumerated type.  This header is expected to always be included
  21 // AFTER unwind.h (which is why it is forcefully included above).  This ensures
  22 // that we do not overwrite the token for the enumeration.  Subsequent uses of
  23 // the token would be clean to rewrite with constant values.
  24 //
  25 // The typedef redeclaration should be safe.  Due to the protection granted to
  26 // us by the `__ARM_EABI_UNWINDER__` above, we are guaranteed that we are in a
  27 // header not vended by gcc.  The HP unwinder (being an itanium unwinder) does
  28 // not support EHABI, and the GNU unwinder, derived from the HP unwinder, also
  29 // does not support EHABI as of the introduction of this header.  As such, we
  30 // are fairly certain that we are in the LLVM case.  Here, _Unwind_State is a
  31 // typedef, and so we can get away with a redeclaration.
  32 //
  33 // Guarded redefinitions of the needed unwind state prevent the redefinition of
  34 // those states.
  35
  36 #define _URC_OK 0
  37 #define _URC_FAILURE 9
  38
  39 typedef uint32_t _Unwind_State;
  40
  41 #if !defined(_US_UNWIND_FRAME_STARTING)
  42 #define _US_UNWIND_FRAME_STARTING ((_Unwind_State)1)
  43 #endif
  44
  45 #if !defined(_US_ACTION_MASK)
  46 #define _US_ACTION_MASK ((_Unwind_State)3)
  47 #endif
  48
  49 #endif
  50
  51 #endif