121 lines
3.9 KiB
C
121 lines
3.9 KiB
C
/* Subroutines needed for unwinding stack frames for exception handling. */
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/* Copyright (C) 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
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Contributed by Jason Merrill <jason@cygnus.com>.
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This file is part of GNU CC.
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GNU CC is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later 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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GNU CC is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License 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 GNU CC; see the file COPYING. If not, write to
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the Free Software Foundation, 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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/* Describes data used to hold onto one shared object or object file. */
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struct 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 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 (void *, struct object *);
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extern void __register_frame (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 (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 specfication, 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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void * pc_begin;
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uaddr pc_range;
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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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