177 lines
5.2 KiB
C
177 lines
5.2 KiB
C
/* Subroutines needed for unwinding stack frames for exception handling. */
|
||
/* Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003
|
||
Free Software Foundation, Inc.
|
||
Contributed by Jason Merrill <jason@cygnus.com>.
|
||
|
||
This file is part of GCC.
|
||
|
||
GCC 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.)
|
||
|
||
GCC 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 GCC; see the file COPYING. If not, write to the Free
|
||
Software Foundation, 59 Temple Place - Suite 330, Boston, MA
|
||
02111-1307, USA. */
|
||
|
||
|
||
struct fde_vector
|
||
{
|
||
void *orig_data;
|
||
size_t count;
|
||
struct dwarf_fde *array[];
|
||
};
|
||
|
||
struct object
|
||
{
|
||
void *pc_begin;
|
||
void *tbase;
|
||
void *dbase;
|
||
union {
|
||
struct dwarf_fde *single;
|
||
struct dwarf_fde **array;
|
||
struct fde_vector *sort;
|
||
} u;
|
||
|
||
union {
|
||
struct {
|
||
unsigned long sorted : 1;
|
||
unsigned long from_array : 1;
|
||
unsigned long mixed_encoding : 1;
|
||
unsigned long encoding : 8;
|
||
/* ??? Wish there was an easy way to detect a 64-bit host here;
|
||
we've got 32 bits left to play with... */
|
||
unsigned long count : 21;
|
||
} b;
|
||
size_t i;
|
||
} s;
|
||
|
||
#ifdef DWARF2_OBJECT_END_PTR_EXTENSION
|
||
char *fde_end;
|
||
#endif
|
||
|
||
struct object *next;
|
||
};
|
||
|
||
/* This is the original definition of struct object. While the struct
|
||
itself was opaque to users, they did know how large it was, and
|
||
allocate one statically in crtbegin for each DSO. Keep this around
|
||
so that we're aware of the static size limitations for the new struct. */
|
||
struct old_object
|
||
{
|
||
void *pc_begin;
|
||
void *pc_end;
|
||
struct dwarf_fde *fde_begin;
|
||
struct dwarf_fde **fde_array;
|
||
size_t count;
|
||
struct old_object *next;
|
||
};
|
||
|
||
struct dwarf_eh_bases
|
||
{
|
||
void *tbase;
|
||
void *dbase;
|
||
void *func;
|
||
};
|
||
|
||
|
||
extern void __register_frame_info_bases (void *, struct object *,
|
||
void *, void *);
|
||
extern void __register_frame_info (void *, struct object *);
|
||
extern void __register_frame (void *);
|
||
extern void __register_frame_info_table_bases (void *, struct object *,
|
||
void *, 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_info_bases (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 specification, 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;
|
||
unsigned char pc_begin[];
|
||
} __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 *);
|
||
|
||
static inline int
|
||
last_fde (struct object *obj __attribute__ ((__unused__)), fde *f)
|
||
{
|
||
#ifdef DWARF2_OBJECT_END_PTR_EXTENSION
|
||
return (char *)f == obj->fde_end || f->length == 0;
|
||
#else
|
||
return f->length == 0;
|
||
#endif
|
||
}
|