libunwind/include/unwind_arm_ehabi.h

   1 //===----------------------------------------------------------------------===//
   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 // C++ ABI Level 1 ABI documented at:
   9 //   https://github.com/ARM-software/abi-aa/blob/main/ehabi32/ehabi32.rst
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #ifndef __ARM_EHABI_UNWIND_H__
  14 #define __ARM_EHABI_UNWIND_H__
  15
  16 typedef uint32_t _Unwind_State;
  17
  18 static const _Unwind_State _US_VIRTUAL_UNWIND_FRAME   = 0;
  19 static const _Unwind_State _US_UNWIND_FRAME_STARTING  = 1;
  20 static const _Unwind_State _US_UNWIND_FRAME_RESUME    = 2;
  21 static const _Unwind_State _US_ACTION_MASK            = 3;
  22 /* Undocumented flag for force unwinding. */
  23 static const _Unwind_State _US_FORCE_UNWIND           = 8;
  24
  25 typedef uint32_t _Unwind_EHT_Header;
  26
  27 struct _Unwind_Control_Block;
  28 typedef struct _Unwind_Control_Block _Unwind_Control_Block;
  29 #define _Unwind_Exception _Unwind_Control_Block /* Alias */
  30 typedef uint8_t _Unwind_Exception_Class[8];
  31
  32 struct _Unwind_Control_Block {
  33   _Unwind_Exception_Class exception_class;
  34   void (*exception_cleanup)(_Unwind_Reason_Code, _Unwind_Control_Block*);
  35
  36   /* Unwinder cache, private fields for the unwinder's use */
  37   struct {
  38     uint32_t reserved1; /* init reserved1 to 0, then don't touch */
  39     uint32_t reserved2;
  40     uint32_t reserved3;
  41     uint32_t reserved4;
  42     uint32_t reserved5;
  43   } unwinder_cache;
  44
  45   /* Propagation barrier cache (valid after phase 1): */
  46   struct {
  47     uint32_t sp;
  48     uint32_t bitpattern[5];
  49   } barrier_cache;
  50
  51   /* Cleanup cache (preserved over cleanup): */
  52   struct {
  53     uint32_t bitpattern[4];
  54   } cleanup_cache;
  55
  56   /* Pr cache (for pr's benefit): */
  57   struct {
  58     uint32_t fnstart; /* function start address */
  59     _Unwind_EHT_Header* ehtp; /* pointer to EHT entry header word */
  60     uint32_t additional;
  61     uint32_t reserved1;
  62   } pr_cache;
  63
  64   long long int :0; /* Enforce the 8-byte alignment */
  65 } __attribute__((__aligned__(8)));
  66
  67 typedef _Unwind_Reason_Code (*_Unwind_Personality_Fn)(
  68     _Unwind_State state, _Unwind_Exception *exceptionObject,
  69     struct _Unwind_Context *context);
  70
  71 #ifdef __cplusplus
  72 extern "C" {
  73 #endif
  74
  75 //
  76 // The following are the base functions documented by the C++ ABI
  77 //
  78 #ifdef __USING_SJLJ_EXCEPTIONS__
  79 extern _Unwind_Reason_Code
  80     _Unwind_SjLj_RaiseException(_Unwind_Exception *exception_object);
  81 extern void _Unwind_SjLj_Resume(_Unwind_Exception *exception_object);
  82 #else
  83 extern _Unwind_Reason_Code
  84     _Unwind_RaiseException(_Unwind_Exception *exception_object);
  85 extern void _Unwind_Resume(_Unwind_Exception *exception_object);
  86 #endif
  87 extern void _Unwind_DeleteException(_Unwind_Exception *exception_object);
  88
  89 typedef enum {
  90   _UVRSC_CORE = 0,  /* integer register */
  91   _UVRSC_VFP = 1,   /* vfp */
  92   _UVRSC_WMMXD = 3, /* Intel WMMX data register */
  93   _UVRSC_WMMXC = 4, /* Intel WMMX control register */
  94   _UVRSC_PSEUDO = 5 /* Special purpose pseudo register */
  95 } _Unwind_VRS_RegClass;
  96
  97 typedef enum {
  98   _UVRSD_UINT32 = 0,
  99   _UVRSD_VFPX = 1,
 100   _UVRSD_UINT64 = 3,
 101   _UVRSD_FLOAT = 4,
 102   _UVRSD_DOUBLE = 5
 103 } _Unwind_VRS_DataRepresentation;
 104
 105 typedef enum {
 106   _UVRSR_OK = 0,
 107   _UVRSR_NOT_IMPLEMENTED = 1,
 108   _UVRSR_FAILED = 2
 109 } _Unwind_VRS_Result;
 110
 111 extern void _Unwind_Complete(_Unwind_Exception* exception_object);
 112
 113 extern _Unwind_VRS_Result
 114 _Unwind_VRS_Get(_Unwind_Context *context, _Unwind_VRS_RegClass regclass,
 115                 uint32_t regno, _Unwind_VRS_DataRepresentation representation,
 116                 void *valuep);
 117
 118 extern _Unwind_VRS_Result
 119 _Unwind_VRS_Set(_Unwind_Context *context, _Unwind_VRS_RegClass regclass,
 120                 uint32_t regno, _Unwind_VRS_DataRepresentation representation,
 121                 void *valuep);
 122
 123 extern _Unwind_VRS_Result
 124 _Unwind_VRS_Pop(_Unwind_Context *context, _Unwind_VRS_RegClass regclass,
 125                 uint32_t discriminator,
 126                 _Unwind_VRS_DataRepresentation representation);
 127
 128 #if defined(_LIBUNWIND_UNWIND_LEVEL1_EXTERNAL_LINKAGE)
 129 #define _LIBUNWIND_EXPORT_UNWIND_LEVEL1 extern
 130 #else
 131 #define _LIBUNWIND_EXPORT_UNWIND_LEVEL1 static __inline__
 132 #endif
 133
 134 // These are de facto helper functions for ARM, which delegate the function
 135 // calls to _Unwind_VRS_Get/Set().  These are not a part of ARM EHABI
 136 // specification, thus these function MUST be inlined.  Please don't replace
 137 // these with the "extern" function declaration; otherwise, the program
 138 // including this <unwind.h> header won't be ABI compatible and will result in
 139 // link error when we are linking the program with libgcc.
 140
 141 _LIBUNWIND_EXPORT_UNWIND_LEVEL1
 142 uintptr_t _Unwind_GetGR(struct _Unwind_Context *context, int index) {
 143   uintptr_t value = 0;
 144   _Unwind_VRS_Get(context, _UVRSC_CORE, (uint32_t)index, _UVRSD_UINT32, &value);
 145   return value;
 146 }
 147
 148 _LIBUNWIND_EXPORT_UNWIND_LEVEL1
 149 void _Unwind_SetGR(struct _Unwind_Context *context, int index,
 150                    uintptr_t value) {
 151   _Unwind_VRS_Set(context, _UVRSC_CORE, (uint32_t)index, _UVRSD_UINT32, &value);
 152 }
 153
 154 _LIBUNWIND_EXPORT_UNWIND_LEVEL1
 155 uintptr_t _Unwind_GetIP(struct _Unwind_Context *context) {
 156   // remove the thumb-bit before returning
 157   return _Unwind_GetGR(context, 15) & (~(uintptr_t)0x1);
 158 }
 159
 160 _LIBUNWIND_EXPORT_UNWIND_LEVEL1
 161 void _Unwind_SetIP(struct _Unwind_Context *context, uintptr_t value) {
 162   uintptr_t thumb_bit = _Unwind_GetGR(context, 15) & ((uintptr_t)0x1);
 163   _Unwind_SetGR(context, 15, value | thumb_bit);
 164 }
 165
 166 #ifdef __cplusplus
 167 }
 168 #endif
 169
 170 #endif // __ARM_EHABI_UNWIND_H__