163 lines
4.9 KiB
C
163 lines
4.9 KiB
C
/* Subroutines needed for unwinding stack frames for exception handling. */
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/* Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002
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Free Software Foundation, Inc.
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Contributed by Jason Merrill <jason@cygnus.com>.
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify it under
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the terms of the GNU General Public License as published by the Free
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Software Foundation; either version 2, or (at your option) any later
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version.
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In addition to the permissions in the GNU General Public License, the
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Free Software Foundation gives you unlimited permission to link the
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compiled version of this file into combinations with other programs,
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and to distribute those combinations without any restriction coming
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from the use of this file. (The General Public License restrictions
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do apply in other respects; for example, they cover modification of
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the file, and distribution when not linked into a combine
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executable.)
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GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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for more details.
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You should have received a copy of the GNU General Public License
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along with GCC; see the file COPYING. If not, write to the Free
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Software Foundation, 59 Temple Place - Suite 330, Boston, MA
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02111-1307, USA. */
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struct fde_vector
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{
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void *orig_data;
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size_t count;
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struct dwarf_fde *array[];
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};
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struct object
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{
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void *pc_begin;
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void *tbase;
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void *dbase;
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union {
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struct dwarf_fde *single;
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struct dwarf_fde **array;
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struct fde_vector *sort;
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} u;
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union {
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struct {
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unsigned long sorted : 1;
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unsigned long from_array : 1;
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unsigned long mixed_encoding : 1;
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unsigned long encoding : 8;
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/* ??? Wish there was an easy way to detect a 64-bit host here;
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we've got 32 bits left to play with... */
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unsigned long count : 21;
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} b;
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size_t i;
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} s;
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struct object *next;
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};
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/* This is the original definition of struct object. While the struct
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itself was opaque to users, they did know how large it was, and
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allocate one statically in crtbegin for each DSO. Keep this around
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so that we're aware of the static size limitations for the new struct. */
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struct old_object
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{
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void *pc_begin;
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void *pc_end;
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struct dwarf_fde *fde_begin;
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struct dwarf_fde **fde_array;
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size_t count;
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struct old_object *next;
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};
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struct dwarf_eh_bases
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{
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void *tbase;
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void *dbase;
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void *func;
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};
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extern void __register_frame_info_bases (void *, struct object *,
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void *, void *);
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extern void __register_frame_info (void *, struct object *);
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extern void __register_frame (void *);
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extern void __register_frame_info_table_bases (void *, struct object *,
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void *, void *);
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extern void __register_frame_info_table (void *, struct object *);
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extern void __register_frame_table (void *);
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extern void *__deregister_frame_info (void *);
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extern void *__deregister_frame_info_bases (void *);
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extern void __deregister_frame (void *);
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typedef int sword __attribute__ ((mode (SI)));
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typedef unsigned int uword __attribute__ ((mode (SI)));
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typedef unsigned int uaddr __attribute__ ((mode (pointer)));
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typedef int saddr __attribute__ ((mode (pointer)));
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typedef unsigned char ubyte;
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/* Terminology:
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CIE - Common Information Element
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FDE - Frame Descriptor Element
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There is one per function, and it describes where the function code
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is located, and what the register lifetimes and stack layout are
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within the function.
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The data structures are defined in the DWARF specification, although
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not in a very readable way (see LITERATURE).
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Every time an exception is thrown, the code needs to locate the FDE
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for the current function, and starts to look for exception regions
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from that FDE. This works in a two-level search:
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a) in a linear search, find the shared image (i.e. DLL) containing
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the PC
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b) using the FDE table for that shared object, locate the FDE using
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binary search (which requires the sorting). */
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/* The first few fields of a CIE. The CIE_id field is 0 for a CIE,
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to distinguish it from a valid FDE. FDEs are aligned to an addressing
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unit boundary, but the fields within are unaligned. */
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struct dwarf_cie
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{
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uword length;
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sword CIE_id;
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ubyte version;
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unsigned char augmentation[];
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} __attribute__ ((packed, aligned (__alignof__ (void *))));
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/* The first few fields of an FDE. */
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struct dwarf_fde
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{
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uword length;
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sword CIE_delta;
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unsigned char pc_begin[];
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} __attribute__ ((packed, aligned (__alignof__ (void *))));
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typedef struct dwarf_fde fde;
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/* Locate the CIE for a given FDE. */
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static inline struct dwarf_cie *
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get_cie (struct dwarf_fde *f)
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{
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return (void *)&f->CIE_delta - f->CIE_delta;
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}
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static inline fde *
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next_fde (fde *f)
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{
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return (fde *) ((char *) f + f->length + sizeof (f->length));
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}
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extern fde * _Unwind_Find_FDE (void *, struct dwarf_eh_bases *);
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