headers/libs/libunwind/libunwind-dynamic.h

   1 /* libunwind - a platform-independent unwind library
   2    Copyright (C) 2002-2004 Hewlett-Packard Co
   3         Contributed by David Mosberger-Tang <davidm@hpl.hp.com>
   4
   5 This file is part of libunwind.
   6
   7 Permission is hereby granted, free of charge, to any person obtaining
   8 a copy of this software and associated documentation files (the
   9 "Software"), to deal in the Software without restriction, including
  10 without limitation the rights to use, copy, modify, merge, publish,
  11 distribute, sublicense, and/or sell copies of the Software, and to
  12 permit persons to whom the Software is furnished to do so, subject to
  13 the following conditions:
  14
  15 The above copyright notice and this permission notice shall be
  16 included in all copies or substantial portions of the Software.
  17
  18 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  19 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  21 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  22 LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  23 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  24 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  */
  25
  26 /* This file defines the runtime-support routines for dynamically
  27 generated code.  Even though it is implemented as part of libunwind,
  28 it is logically separate from the interface to perform the actual
  29 unwinding.  In particular, this interface is always used in the
  30 context of the unwind target, whereas the rest of the unwind API is
  31 used in context of the process that is doing the unwind (which may be
  32 a debugger running on another machine, for example).
  33
  34 Note that the data-structures declared here server a dual purpose:
  35 when a program registers a dynamically generated procedure, it uses
  36 these structures directly.  On the other hand, with remote-unwinding,
  37 the data-structures are read from the remote process's memory and
  38 translated into internalized versions.  To facilitate remote-access,
  39 the following rules should be followed in declaring these structures:
  40
  41  (1) Declare a member as a pointer only if the the information the
  42      member points to needs to be internalized as well (e.g., a
  43      string representing a procedure name should be declared as
  44      "const char *", but the instruction pointer should be declared
  45      as unw_word_t).
  46
  47  (2) Provide sufficient padding to ensure that no implicit padding
  48      will be needed on any of the supported target architectures.  For
  49      the time being, padding data structures with the assumption that
  50      sizeof (unw_word_t) == 8 should be sufficient.  (Note: it's not
  51      impossible to internalize structures with internal padding, but
  52      it does make the process a bit harder).
  53
  54  (3) Don't declare members that contain bitfields or floating-point
  55      values.
  56
  57  (4) Don't declare members with enumeration types.  Declare them as
  58      int32_t instead.  */
  59
  60 typedef enum
  61   {
  62     UNW_DYN_STOP = 0,           /* end-of-unwind-info marker */
  63     UNW_DYN_SAVE_REG,           /* save register to another register */
  64     UNW_DYN_SPILL_FP_REL,       /* frame-pointer-relative register spill */
  65     UNW_DYN_SPILL_SP_REL,       /* stack-pointer-relative register spill */
  66     UNW_DYN_ADD,                /* add constant value to a register */
  67     UNW_DYN_POP_FRAMES,         /* drop one or more stack frames */
  68     UNW_DYN_LABEL_STATE,        /* name the current state */
  69     UNW_DYN_COPY_STATE,         /* set the region's entry-state */
  70     UNW_DYN_ALIAS               /* get unwind info from an alias */
  71   }
  72 unw_dyn_operation_t;
  73
  74 typedef enum
  75   {
  76     UNW_INFO_FORMAT_DYNAMIC,            /* unw_dyn_proc_info_t */
  77     UNW_INFO_FORMAT_TABLE,              /* unw_dyn_table_t */
  78     UNW_INFO_FORMAT_REMOTE_TABLE,       /* unw_dyn_remote_table_t */
  79     UNW_INFO_FORMAT_ARM_EXIDX           /* ARM specific unwind info */
  80   }
  81 unw_dyn_info_format_t;
  82
  83 typedef struct unw_dyn_op
  84   {
  85     int8_t tag;                         /* what operation? */
  86     int8_t qp;                          /* qualifying predicate register */
  87     int16_t reg;                        /* what register */
  88     int32_t when;                       /* when does it take effect? */
  89     unw_word_t val;                     /* auxiliary value */
  90   }
  91 unw_dyn_op_t;
  92
  93 typedef struct unw_dyn_region_info
  94   {
  95     struct unw_dyn_region_info *next;   /* linked list of regions */
  96     int32_t insn_count;                 /* region length (# of instructions) */
  97     uint32_t op_count;                  /* length of op-array */
  98     unw_dyn_op_t op[1];                 /* variable-length op-array */
  99   }
 100 unw_dyn_region_info_t;
 101
 102 typedef struct unw_dyn_proc_info
 103   {
 104     unw_word_t name_ptr;        /* address of human-readable procedure name */
 105     unw_word_t handler;         /* address of personality routine */
 106     uint32_t flags;
 107     int32_t pad0;
 108     unw_dyn_region_info_t *regions;
 109   }
 110 unw_dyn_proc_info_t;
 111
 112 typedef struct unw_dyn_table_info
 113   {
 114     unw_word_t name_ptr;        /* addr. of table name (e.g., library name) */
 115     unw_word_t segbase;         /* segment base */
 116     unw_word_t table_len;       /* must be a multiple of sizeof(unw_word_t)! */
 117     unw_word_t *table_data;
 118   }
 119 unw_dyn_table_info_t;
 120
 121 typedef struct unw_dyn_remote_table_info
 122   {
 123     unw_word_t name_ptr;        /* addr. of table name (e.g., library name) */
 124     unw_word_t segbase;         /* segment base */
 125     unw_word_t table_len;       /* must be a multiple of sizeof(unw_word_t)! */
 126     unw_word_t table_data;
 127   }
 128 unw_dyn_remote_table_info_t;
 129
 130 typedef struct unw_dyn_info
 131   {
 132     /* doubly-linked list of dyn-info structures: */
 133     struct unw_dyn_info *next;
 134     struct unw_dyn_info *prev;
 135     unw_word_t start_ip;        /* first IP covered by this entry */
 136     unw_word_t end_ip;          /* first IP NOT covered by this entry */
 137     unw_word_t gp;              /* global-pointer in effect for this entry */
 138     int32_t format;             /* real type: unw_dyn_info_format_t */
 139     int32_t pad;
 140     union
 141       {
 142         unw_dyn_proc_info_t pi;
 143         unw_dyn_table_info_t ti;
 144         unw_dyn_remote_table_info_t rti;
 145       }
 146     u;
 147   }
 148 unw_dyn_info_t;
 149
 150 typedef struct unw_dyn_info_list
 151   {
 152     uint32_t version;
 153     uint32_t generation;
 154     unw_dyn_info_t *first;
 155   }
 156 unw_dyn_info_list_t;
 157
 158 /* Return the size (in bytes) of an unw_dyn_region_info_t structure that can
 159    hold OP_COUNT ops.  */
 160 #define _U_dyn_region_info_size(op_count)                               \
 161         ((char *) (((unw_dyn_region_info_t *) NULL)->op + (op_count))   \
 162          - (char *) NULL)
 163
 164 /* Register the unwind info for a single procedure.
 165    This routine is NOT signal-safe.  */
 166 extern void _U_dyn_register (unw_dyn_info_t *);
 167
 168 /* Cancel the unwind info for a single procedure.
 169    This routine is NOT signal-safe.  */
 170 extern void _U_dyn_cancel (unw_dyn_info_t *);
 171
 172 \f
 173 /* Convenience routines.  */
 174
 175 #define _U_dyn_op(_tag, _qp, _when, _reg, _val)                         \
 176         ((unw_dyn_op_t) { (_tag), (_qp), (_reg), (_when), (_val) })
 177
 178 #define _U_dyn_op_save_reg(op, qp, when, reg, dst)                      \
 179         (*(op) = _U_dyn_op (UNW_DYN_SAVE_REG, (qp), (when), (reg), (dst)))
 180
 181 #define _U_dyn_op_spill_fp_rel(op, qp, when, reg, offset)               \
 182         (*(op) = _U_dyn_op (UNW_DYN_SPILL_FP_REL, (qp), (when), (reg),  \
 183                             (offset)))
 184
 185 #define _U_dyn_op_spill_sp_rel(op, qp, when, reg, offset)               \
 186         (*(op) = _U_dyn_op (UNW_DYN_SPILL_SP_REL, (qp), (when), (reg),  \
 187                             (offset)))
 188
 189 #define _U_dyn_op_add(op, qp, when, reg, value)                         \
 190         (*(op) = _U_dyn_op (UNW_DYN_ADD, (qp), (when), (reg), (value)))
 191
 192 #define _U_dyn_op_pop_frames(op, qp, when, num_frames)                  \
 193         (*(op) = _U_dyn_op (UNW_DYN_POP_FRAMES, (qp), (when), 0, (num_frames)))
 194
 195 #define _U_dyn_op_label_state(op, label)                                \
 196         (*(op) = _U_dyn_op (UNW_DYN_LABEL_STATE, _U_QP_TRUE, -1, 0, (label)))
 197
 198 #define _U_dyn_op_copy_state(op, label)                                 \
 199         (*(op) = _U_dyn_op (UNW_DYN_COPY_STATE, _U_QP_TRUE, -1, 0, (label)))
 200
 201 #define _U_dyn_op_alias(op, qp, when, addr)                             \
 202         (*(op) = _U_dyn_op (UNW_DYN_ALIAS, (qp), (when), 0, (addr)))
 203
 204 #define _U_dyn_op_stop(op)                                              \
 205         (*(op) = _U_dyn_op (UNW_DYN_STOP, _U_QP_TRUE, -1, 0, 0))
 206
 207 /* The target-dependent qualifying predicate which is always TRUE.  On
 208    IA-64, that's p0 (0), on non-predicated architectures, the value is
 209    ignored.  */
 210 #define _U_QP_TRUE      _U_TDEP_QP_TRUE