| /* Subroutines needed for unwinding stack frames for exception handling. */ |
| /* Copyright (C) 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc. |
| Contributed by Jason Merrill <jason@cygnus.com>. |
| |
| This file is part of GNU CC. |
| |
| GNU CC is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| In addition to the permissions in the GNU General Public License, the |
| Free Software Foundation gives you unlimited permission to link the |
| compiled version of this file into combinations with other programs, |
| and to distribute those combinations without any restriction coming |
| from the use of this file. (The General Public License restrictions |
| do apply in other respects; for example, they cover modification of |
| the file, and distribution when not linked into a combine |
| executable.) |
| |
| GNU CC is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU CC; see the file COPYING. If not, write to |
| the Free Software Foundation, 59 Temple Place - Suite 330, |
| Boston, MA 02111-1307, USA. */ |
| |
| |
| /* Describes data used to hold onto one shared object or object file. */ |
| struct object |
| { |
| void *pc_begin; |
| void *pc_end; |
| struct dwarf_fde *fde_begin; |
| struct dwarf_fde **fde_array; |
| size_t count; |
| struct object *next; |
| }; |
| |
| struct dwarf_eh_bases |
| { |
| void *tbase; |
| void *dbase; |
| void *func; |
| }; |
| |
| |
| extern void __register_frame_info (void *, struct object *); |
| extern void __register_frame (void *); |
| extern void __register_frame_info_table (void *, struct object *); |
| extern void __register_frame_table (void *); |
| extern void *__deregister_frame_info (void *); |
| extern void __deregister_frame (void *); |
| |
| |
| typedef int sword __attribute__ ((mode (SI))); |
| typedef unsigned int uword __attribute__ ((mode (SI))); |
| typedef unsigned int uaddr __attribute__ ((mode (pointer))); |
| typedef int saddr __attribute__ ((mode (pointer))); |
| typedef unsigned char ubyte; |
| |
| /* Terminology: |
| CIE - Common Information Element |
| FDE - Frame Descriptor Element |
| |
| There is one per function, and it describes where the function code |
| is located, and what the register lifetimes and stack layout are |
| within the function. |
| |
| The data structures are defined in the DWARF specfication, although |
| not in a very readable way (see LITERATURE). |
| |
| Every time an exception is thrown, the code needs to locate the FDE |
| for the current function, and starts to look for exception regions |
| from that FDE. This works in a two-level search: |
| a) in a linear search, find the shared image (i.e. DLL) containing |
| the PC |
| b) using the FDE table for that shared object, locate the FDE using |
| binary search (which requires the sorting). */ |
| |
| /* The first few fields of a CIE. The CIE_id field is 0 for a CIE, |
| to distinguish it from a valid FDE. FDEs are aligned to an addressing |
| unit boundary, but the fields within are unaligned. */ |
| struct dwarf_cie |
| { |
| uword length; |
| sword CIE_id; |
| ubyte version; |
| unsigned char augmentation[]; |
| } __attribute__ ((packed, aligned (__alignof__ (void *)))); |
| |
| /* The first few fields of an FDE. */ |
| struct dwarf_fde |
| { |
| uword length; |
| sword CIE_delta; |
| void * pc_begin; |
| uaddr pc_range; |
| } __attribute__ ((packed, aligned (__alignof__ (void *)))); |
| |
| typedef struct dwarf_fde fde; |
| |
| /* Locate the CIE for a given FDE. */ |
| |
| static inline struct dwarf_cie * |
| get_cie (struct dwarf_fde *f) |
| { |
| return (void *)&f->CIE_delta - f->CIE_delta; |
| } |
| |
| static inline fde * |
| next_fde (fde *f) |
| { |
| return (fde *)((char *)f + f->length + sizeof (f->length)); |
| } |
| |
| extern fde * _Unwind_Find_FDE (void *, struct dwarf_eh_bases *); |