Subversion Repositories Kolibri OS

Rev

Blame | Last modification | View Log | RSS feed

  1. /* Subroutines needed for unwinding stack frames for exception handling.  */
  2. /* Copyright (C) 1997-2015 Free Software Foundation, Inc.
  3.    Contributed by Jason Merrill <jason@cygnus.com>.
  4.  
  5. This file is part of GCC.
  6.  
  7. GCC is free software; you can redistribute it and/or modify it under
  8. the terms of the GNU General Public License as published by the Free
  9. Software Foundation; either version 3, or (at your option) any later
  10. version.
  11.  
  12. GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13. WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14. FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15. for more details.
  16.  
  17. Under Section 7 of GPL version 3, you are granted additional
  18. permissions described in the GCC Runtime Library Exception, version
  19. 3.1, as published by the Free Software Foundation.
  20.  
  21. You should have received a copy of the GNU General Public License and
  22. a copy of the GCC Runtime Library Exception along with this program;
  23. see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  24. <http://www.gnu.org/licenses/>.  */
  25.  
  26. #ifndef GCC_UNWIND_DW2_FDE_H
  27. #define GCC_UNWIND_DW2_FDE_H
  28.  
  29. #ifndef HIDE_EXPORTS
  30. #pragma GCC visibility push(default)
  31. #endif
  32.  
  33. struct fde_vector
  34. {
  35.   const void *orig_data;
  36.   size_t count;
  37.   const struct dwarf_fde *array[];
  38. };
  39.  
  40. struct object
  41. {
  42.   void *pc_begin;
  43.   void *tbase;
  44.   void *dbase;
  45.   union {
  46.     const struct dwarf_fde *single;
  47.     struct dwarf_fde **array;
  48.     struct fde_vector *sort;
  49.   } u;
  50.  
  51.   union {
  52.     struct {
  53.       unsigned long sorted : 1;
  54.       unsigned long from_array : 1;
  55.       unsigned long mixed_encoding : 1;
  56.       unsigned long encoding : 8;
  57.       /* ??? Wish there was an easy way to detect a 64-bit host here;
  58.          we've got 32 bits left to play with...  */
  59.       unsigned long count : 21;
  60.     } b;
  61.     size_t i;
  62.   } s;
  63.  
  64. #ifdef DWARF2_OBJECT_END_PTR_EXTENSION
  65.   char *fde_end;
  66. #endif
  67.  
  68.   struct object *next;
  69. };
  70.  
  71. /* This is the original definition of struct object.  While the struct
  72.    itself was opaque to users, they did know how large it was, and
  73.    allocate one statically in crtbegin for each DSO.  Keep this around
  74.    so that we're aware of the static size limitations for the new struct.  */
  75. struct old_object
  76. {
  77.   void *pc_begin;
  78.   void *pc_end;
  79.   struct dwarf_fde *fde_begin;
  80.   struct dwarf_fde **fde_array;
  81.   size_t count;
  82.   struct old_object *next;
  83. };
  84.  
  85. struct dwarf_eh_bases
  86. {
  87.   void *tbase;
  88.   void *dbase;
  89.   void *func;
  90. };
  91.  
  92.  
  93. extern void __register_frame_info_bases (const void *, struct object *,
  94.                                          void *, void *);
  95. extern void __register_frame_info (const void *, struct object *);
  96. extern void __register_frame (void *);
  97. extern void __register_frame_info_table_bases (void *, struct object *,
  98.                                                void *, void *);
  99. extern void __register_frame_info_table (void *, struct object *);
  100. extern void __register_frame_table (void *);
  101. extern void *__deregister_frame_info (const void *);
  102. extern void *__deregister_frame_info_bases (const void *);
  103. extern void __deregister_frame (void *);
  104.  
  106. typedef          int  sword __attribute__ ((mode (SI)));
  107. typedef unsigned int  uword __attribute__ ((mode (SI)));
  108. typedef unsigned int  uaddr __attribute__ ((mode (pointer)));
  109. typedef          int  saddr __attribute__ ((mode (pointer)));
  110. typedef unsigned char ubyte;
  111.  
  112. /* Terminology:
  113.    CIE - Common Information Element
  114.    FDE - Frame Descriptor Element
  115.  
  116.    There is one per function, and it describes where the function code
  117.    is located, and what the register lifetimes and stack layout are
  118.    within the function.
  119.  
  120.    The data structures are defined in the DWARF specification, although
  121.    not in a very readable way (see LITERATURE).
  122.  
  123.    Every time an exception is thrown, the code needs to locate the FDE
  124.    for the current function, and starts to look for exception regions
  125.    from that FDE. This works in a two-level search:
  126.    a) in a linear search, find the shared image (i.e. DLL) containing
  127.       the PC
  128.    b) using the FDE table for that shared object, locate the FDE using
  129.       binary search (which requires the sorting).  */
  130.  
  131. /* The first few fields of a CIE.  The CIE_id field is 0 for a CIE,
  132.    to distinguish it from a valid FDE.  FDEs are aligned to an addressing
  133.    unit boundary, but the fields within are unaligned.  */
  134. struct dwarf_cie
  135. {
  136.   uword length;
  137.   sword CIE_id;
  138.   ubyte version;
  139.   unsigned char augmentation[];
  140. } __attribute__ ((packed, aligned (__alignof__ (void *))));
  141.  
  142. /* The first few fields of an FDE.  */
  143. struct dwarf_fde
  144. {
  145.   uword length;
  146.   sword CIE_delta;
  147.   unsigned char pc_begin[];
  148. } __attribute__ ((packed, aligned (__alignof__ (void *))));
  149.  
  150. typedef struct dwarf_fde fde;
  151.  
  152. /* Locate the CIE for a given FDE.  */
  153.  
  154. static inline const struct dwarf_cie *
  155. get_cie (const struct dwarf_fde *f)
  156. {
  157.   return (const void *)&f->CIE_delta - f->CIE_delta;
  158. }
  159.  
  160. static inline const fde *
  161. next_fde (const fde *f)
  162. {
  163.   return (const fde *) ((const char *) f + f->length + sizeof (f->length));
  164. }
  165.  
  166. extern const fde * _Unwind_Find_FDE (void *, struct dwarf_eh_bases *);
  167.  
  168. static inline int
  169. last_fde (struct object *obj __attribute__ ((__unused__)), const fde *f)
  170. {
  171. #ifdef DWARF2_OBJECT_END_PTR_EXTENSION
  172.   return f == (const fde *) obj->fde_end || f->length == 0;
  173. #else
  174.   return f->length == 0;
  175. #endif
  176. }
  177.  
  178. #ifndef HIDE_EXPORTS
  179. #pragma GCC visibility pop
  180. #endif
  181.  
  182. #endif /* unwind-dw2-fde.h */
  183.