865 lines
21 KiB
C
865 lines
21 KiB
C
/* Subroutines needed for unwinding stack frames for exception handling. */
|
||
/* Compile this one with gcc. */
|
||
/* Copyright (C) 1997, 1998 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.
|
||
|
||
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. */
|
||
|
||
/* As a special exception, if you link this library with other files,
|
||
some of which are compiled with GCC, to produce an executable,
|
||
this library does not by itself cause the resulting executable
|
||
to be covered by the GNU General Public License.
|
||
This exception does not however invalidate any other reasons why
|
||
the executable file might be covered by the GNU General Public License. */
|
||
|
||
/* It is incorrect to include config.h here, because this file is being
|
||
compiled for the target, and hence definitions concerning only the host
|
||
do not apply. */
|
||
|
||
#include "tconfig.h"
|
||
|
||
/* We disable this when inhibit_libc, so that gcc can still be built without
|
||
needing header files first. */
|
||
/* ??? This is not a good solution, since prototypes may be required in
|
||
some cases for correct code. See also libgcc2.c. */
|
||
#ifndef inhibit_libc
|
||
/* fixproto guarantees these system headers exist. */
|
||
#include <stdlib.h>
|
||
#include <unistd.h>
|
||
#endif
|
||
|
||
#include "defaults.h"
|
||
|
||
#ifdef DWARF2_UNWIND_INFO
|
||
#include "dwarf2.h"
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||
#include <stddef.h>
|
||
#include "frame.h"
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||
#include "gthr.h"
|
||
|
||
#ifdef __GTHREAD_MUTEX_INIT
|
||
static __gthread_mutex_t object_mutex = __GTHREAD_MUTEX_INIT;
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||
#else
|
||
static __gthread_mutex_t object_mutex;
|
||
#endif
|
||
|
||
/* Don't use `fancy_abort' here even if config.h says to use it. */
|
||
#ifdef abort
|
||
#undef abort
|
||
#endif
|
||
|
||
/* Some types used by the DWARF 2 spec. */
|
||
|
||
typedef int sword __attribute__ ((mode (SI)));
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||
typedef unsigned int uword __attribute__ ((mode (SI)));
|
||
typedef unsigned int uaddr __attribute__ ((mode (pointer)));
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||
typedef int saddr __attribute__ ((mode (pointer)));
|
||
typedef unsigned char ubyte;
|
||
|
||
/* Terminology:
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||
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
|
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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;
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||
sword CIE_id;
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||
ubyte version;
|
||
char augmentation[0];
|
||
} __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;
|
||
|
||
/* Objects to be searched for frame unwind info. */
|
||
|
||
static struct object *objects;
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||
|
||
/* The information we care about from a CIE. */
|
||
|
||
struct cie_info {
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||
char *augmentation;
|
||
void *eh_ptr;
|
||
int code_align;
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||
int data_align;
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||
unsigned ra_regno;
|
||
};
|
||
|
||
/* The current unwind state, plus a saved copy for DW_CFA_remember_state. */
|
||
|
||
struct frame_state_internal
|
||
{
|
||
struct frame_state s;
|
||
struct frame_state_internal *saved_state;
|
||
};
|
||
|
||
/* This is undefined below if we need it to be an actual function. */
|
||
#define init_object_mutex_once()
|
||
|
||
#if __GTHREADS
|
||
#ifdef __GTHREAD_MUTEX_INIT_FUNCTION
|
||
|
||
/* Helper for init_object_mutex_once. */
|
||
|
||
static void
|
||
init_object_mutex (void)
|
||
{
|
||
__GTHREAD_MUTEX_INIT_FUNCTION (&object_mutex);
|
||
}
|
||
|
||
/* Call this to arrange to initialize the object mutex. */
|
||
|
||
#undef init_object_mutex_once
|
||
static void
|
||
init_object_mutex_once (void)
|
||
{
|
||
static __gthread_once_t once = __GTHREAD_ONCE_INIT;
|
||
__gthread_once (&once, init_object_mutex);
|
||
}
|
||
|
||
#endif /* __GTHREAD_MUTEX_INIT_FUNCTION */
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||
#endif /* __GTHREADS */
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||
|
||
/* Decode the unsigned LEB128 constant at BUF into the variable pointed to
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||
by R, and return the new value of BUF. */
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||
|
||
static void *
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||
decode_uleb128 (unsigned char *buf, unsigned *r)
|
||
{
|
||
unsigned shift = 0;
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||
unsigned result = 0;
|
||
|
||
while (1)
|
||
{
|
||
unsigned byte = *buf++;
|
||
result |= (byte & 0x7f) << shift;
|
||
if ((byte & 0x80) == 0)
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||
break;
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||
shift += 7;
|
||
}
|
||
*r = result;
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||
return buf;
|
||
}
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||
|
||
/* Decode the signed LEB128 constant at BUF into the variable pointed to
|
||
by R, and return the new value of BUF. */
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||
|
||
static void *
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||
decode_sleb128 (unsigned char *buf, int *r)
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||
{
|
||
unsigned shift = 0;
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||
unsigned result = 0;
|
||
unsigned byte;
|
||
|
||
while (1)
|
||
{
|
||
byte = *buf++;
|
||
result |= (byte & 0x7f) << shift;
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||
shift += 7;
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||
if ((byte & 0x80) == 0)
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||
break;
|
||
}
|
||
if (shift < (sizeof (*r) * 8) && (byte & 0x40) != 0)
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||
result |= - (1 << shift);
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||
|
||
*r = result;
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||
return buf;
|
||
}
|
||
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||
/* Read unaligned data from the instruction buffer. */
|
||
|
||
union unaligned {
|
||
void *p;
|
||
unsigned b2 __attribute__ ((mode (HI)));
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||
unsigned b4 __attribute__ ((mode (SI)));
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||
unsigned b8 __attribute__ ((mode (DI)));
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||
} __attribute__ ((packed));
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static inline void *
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||
read_pointer (void *p)
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||
{ union unaligned *up = p; return up->p; }
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||
static inline unsigned
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||
read_1byte (void *p)
|
||
{ return *(unsigned char *)p; }
|
||
static inline unsigned
|
||
read_2byte (void *p)
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||
{ union unaligned *up = p; return up->b2; }
|
||
static inline unsigned
|
||
read_4byte (void *p)
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||
{ union unaligned *up = p; return up->b4; }
|
||
static inline unsigned long
|
||
read_8byte (void *p)
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||
{ union unaligned *up = p; return up->b8; }
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||
|
||
/* Ordering function for FDEs. Functions can't overlap, so we just compare
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||
their starting addresses. */
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||
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||
static inline saddr
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||
fde_compare (fde *x, fde *y)
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||
{
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||
return (saddr)x->pc_begin - (saddr)y->pc_begin;
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||
}
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||
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||
/* Return the address of the FDE after P. */
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||
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static inline fde *
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||
next_fde (fde *p)
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||
{
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||
return (fde *)(((char *)p) + p->length + sizeof (p->length));
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||
}
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||
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||
/* Sorting an array of FDEs by address.
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||
(Ideally we would have the linker sort the FDEs so we don't have to do
|
||
it at run time. But the linkers are not yet prepared for this.) */
|
||
|
||
/* This is a special mix of insertion sort and heap sort, optimized for
|
||
the data sets that actually occur. They look like
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101 102 103 127 128 105 108 110 190 111 115 119 125 160 126 129 130.
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||
I.e. a linearly increasing sequence (coming from functions in the text
|
||
section), with additionally a few unordered elements (coming from functions
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||
in gnu_linkonce sections) whose values are higher than the values in the
|
||
surrounding linear sequence (but not necessarily higher than the values
|
||
at the end of the linear sequence!).
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||
The worst-case total run time is O(N) + O(n log (n)), where N is the
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||
total number of FDEs and n is the number of erratic ones. */
|
||
|
||
typedef struct fde_vector
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||
{
|
||
fde **array;
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||
size_t count;
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||
} fde_vector;
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||
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||
typedef struct fde_accumulator
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||
{
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||
fde_vector linear;
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||
fde_vector erratic;
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||
} fde_accumulator;
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||
|
||
static inline void
|
||
start_fde_sort (fde_accumulator *accu, size_t count)
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||
{
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accu->linear.array = (fde **) malloc (sizeof (fde *) * count);
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accu->erratic.array = (fde **) malloc (sizeof (fde *) * count);
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||
accu->linear.count = 0;
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||
accu->erratic.count = 0;
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||
}
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||
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||
static inline void
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||
fde_insert (fde_accumulator *accu, fde *this_fde)
|
||
{
|
||
accu->linear.array[accu->linear.count++] = this_fde;
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||
}
|
||
|
||
/* Split LINEAR into a linear sequence with low values and an erratic
|
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sequence with high values, put the linear one (of longest possible
|
||
length) into LINEAR and the erratic one into ERRATIC. This is O(N). */
|
||
static inline void
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||
fde_split (fde_vector *linear, fde_vector *erratic)
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||
{
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||
size_t count = linear->count;
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||
size_t linear_max = (size_t) -1;
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||
size_t previous_max[count];
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||
size_t i, j;
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||
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for (i = 0; i < count; i++)
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||
{
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||
for (j = linear_max;
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j != (size_t) -1
|
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&& fde_compare (linear->array[i], linear->array[j]) < 0;
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j = previous_max[j])
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{
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||
erratic->array[erratic->count++] = linear->array[j];
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||
linear->array[j] = (fde *) NULL;
|
||
}
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||
previous_max[i] = j;
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linear_max = i;
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||
}
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||
|
||
for (i = 0, j = 0; i < count; i++)
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if (linear->array[i] != (fde *) NULL)
|
||
linear->array[j++] = linear->array[i];
|
||
linear->count = j;
|
||
}
|
||
|
||
/* This is O(n log(n)). BSD/OS defines heapsort in stdlib.h, so we must
|
||
use a name that does not conflict. */
|
||
static inline void
|
||
frame_heapsort (fde_vector *erratic)
|
||
{
|
||
/* For a description of this algorithm, see:
|
||
Samuel P. Harbison, Guy L. Steele Jr.: C, a reference manual, 2nd ed.,
|
||
p. 60-61. */
|
||
fde ** a = erratic->array;
|
||
/* A portion of the array is called a "heap" if for all i>=0:
|
||
If i and 2i+1 are valid indices, then a[i] >= a[2i+1].
|
||
If i and 2i+2 are valid indices, then a[i] >= a[2i+2]. */
|
||
#define SWAP(x,y) do { fde * tmp = x; x = y; y = tmp; } while (0)
|
||
size_t n = erratic->count;
|
||
size_t m = n;
|
||
size_t i;
|
||
|
||
while (m > 0)
|
||
{
|
||
/* Invariant: a[m..n-1] is a heap. */
|
||
m--;
|
||
for (i = m; 2*i+1 < n; )
|
||
{
|
||
if (2*i+2 < n
|
||
&& fde_compare (a[2*i+2], a[2*i+1]) > 0
|
||
&& fde_compare (a[2*i+2], a[i]) > 0)
|
||
{
|
||
SWAP (a[i], a[2*i+2]);
|
||
i = 2*i+2;
|
||
}
|
||
else if (fde_compare (a[2*i+1], a[i]) > 0)
|
||
{
|
||
SWAP (a[i], a[2*i+1]);
|
||
i = 2*i+1;
|
||
}
|
||
else
|
||
break;
|
||
}
|
||
}
|
||
while (n > 1)
|
||
{
|
||
/* Invariant: a[0..n-1] is a heap. */
|
||
n--;
|
||
SWAP (a[0], a[n]);
|
||
for (i = 0; 2*i+1 < n; )
|
||
{
|
||
if (2*i+2 < n
|
||
&& fde_compare (a[2*i+2], a[2*i+1]) > 0
|
||
&& fde_compare (a[2*i+2], a[i]) > 0)
|
||
{
|
||
SWAP (a[i], a[2*i+2]);
|
||
i = 2*i+2;
|
||
}
|
||
else if (fde_compare (a[2*i+1], a[i]) > 0)
|
||
{
|
||
SWAP (a[i], a[2*i+1]);
|
||
i = 2*i+1;
|
||
}
|
||
else
|
||
break;
|
||
}
|
||
}
|
||
#undef SWAP
|
||
}
|
||
|
||
/* Merge V1 and V2, both sorted, and put the result into V1. */
|
||
static void
|
||
fde_merge (fde_vector *v1, const fde_vector *v2)
|
||
{
|
||
size_t i1, i2;
|
||
fde * fde2;
|
||
|
||
i2 = v2->count;
|
||
if (i2 > 0)
|
||
{
|
||
i1 = v1->count;
|
||
do {
|
||
i2--;
|
||
fde2 = v2->array[i2];
|
||
while (i1 > 0 && fde_compare (v1->array[i1-1], fde2) > 0)
|
||
{
|
||
v1->array[i1+i2] = v1->array[i1-1];
|
||
i1--;
|
||
}
|
||
v1->array[i1+i2] = fde2;
|
||
} while (i2 > 0);
|
||
v1->count += v2->count;
|
||
}
|
||
}
|
||
|
||
static fde **
|
||
end_fde_sort (fde_accumulator *accu, size_t count)
|
||
{
|
||
if (accu->linear.count != count)
|
||
abort ();
|
||
fde_split (&accu->linear, &accu->erratic);
|
||
if (accu->linear.count + accu->erratic.count != count)
|
||
abort ();
|
||
frame_heapsort (&accu->erratic);
|
||
fde_merge (&accu->linear, &accu->erratic);
|
||
free (accu->erratic.array);
|
||
return accu->linear.array;
|
||
}
|
||
|
||
static size_t
|
||
count_fdes (fde *this_fde)
|
||
{
|
||
size_t count;
|
||
|
||
for (count = 0; this_fde->length != 0; this_fde = next_fde (this_fde))
|
||
{
|
||
/* Skip CIEs and linked once FDE entries. */
|
||
if (this_fde->CIE_delta == 0 || this_fde->pc_begin == 0)
|
||
continue;
|
||
|
||
++count;
|
||
}
|
||
|
||
return count;
|
||
}
|
||
|
||
static void
|
||
add_fdes (fde *this_fde, fde_accumulator *accu, void **beg_ptr, void **end_ptr)
|
||
{
|
||
void *pc_begin = *beg_ptr;
|
||
void *pc_end = *end_ptr;
|
||
|
||
for (; this_fde->length != 0; this_fde = next_fde (this_fde))
|
||
{
|
||
/* Skip CIEs and linked once FDE entries. */
|
||
if (this_fde->CIE_delta == 0 || this_fde->pc_begin == 0)
|
||
continue;
|
||
|
||
fde_insert (accu, this_fde);
|
||
|
||
if (this_fde->pc_begin < pc_begin)
|
||
pc_begin = this_fde->pc_begin;
|
||
if (this_fde->pc_begin + this_fde->pc_range > pc_end)
|
||
pc_end = this_fde->pc_begin + this_fde->pc_range;
|
||
}
|
||
|
||
*beg_ptr = pc_begin;
|
||
*end_ptr = pc_end;
|
||
}
|
||
|
||
/* Set up a sorted array of pointers to FDEs for a loaded object. We
|
||
count up the entries before allocating the array because it's likely to
|
||
be faster. */
|
||
|
||
static void
|
||
frame_init (struct object* ob)
|
||
{
|
||
size_t count;
|
||
fde_accumulator accu;
|
||
void *pc_begin, *pc_end;
|
||
|
||
if (ob->fde_array)
|
||
{
|
||
fde **p = ob->fde_array;
|
||
for (count = 0; *p; ++p)
|
||
count += count_fdes (*p);
|
||
}
|
||
else
|
||
count = count_fdes (ob->fde_begin);
|
||
|
||
ob->count = count;
|
||
|
||
start_fde_sort (&accu, count);
|
||
pc_begin = (void*)(uaddr)-1;
|
||
pc_end = 0;
|
||
|
||
if (ob->fde_array)
|
||
{
|
||
fde **p = ob->fde_array;
|
||
for (; *p; ++p)
|
||
add_fdes (*p, &accu, &pc_begin, &pc_end);
|
||
}
|
||
else
|
||
add_fdes (ob->fde_begin, &accu, &pc_begin, &pc_end);
|
||
|
||
ob->fde_array = end_fde_sort (&accu, count);
|
||
ob->pc_begin = pc_begin;
|
||
ob->pc_end = pc_end;
|
||
}
|
||
|
||
/* Return a pointer to the FDE for the function containing PC. */
|
||
|
||
static fde *
|
||
find_fde (void *pc)
|
||
{
|
||
struct object *ob;
|
||
size_t lo, hi;
|
||
|
||
init_object_mutex_once ();
|
||
__gthread_mutex_lock (&object_mutex);
|
||
|
||
for (ob = objects; ob; ob = ob->next)
|
||
{
|
||
if (ob->pc_begin == 0)
|
||
frame_init (ob);
|
||
if (pc >= ob->pc_begin && pc < ob->pc_end)
|
||
break;
|
||
}
|
||
|
||
__gthread_mutex_unlock (&object_mutex);
|
||
|
||
if (ob == 0)
|
||
return 0;
|
||
|
||
/* Standard binary search algorithm. */
|
||
for (lo = 0, hi = ob->count; lo < hi; )
|
||
{
|
||
size_t i = (lo + hi) / 2;
|
||
fde *f = ob->fde_array[i];
|
||
|
||
if (pc < f->pc_begin)
|
||
hi = i;
|
||
else if (pc >= f->pc_begin + f->pc_range)
|
||
lo = i + 1;
|
||
else
|
||
return f;
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
static inline struct dwarf_cie *
|
||
get_cie (fde *f)
|
||
{
|
||
return ((void *)&f->CIE_delta) - f->CIE_delta;
|
||
}
|
||
|
||
/* Extract any interesting information from the CIE for the translation
|
||
unit F belongs to. */
|
||
|
||
static void *
|
||
extract_cie_info (fde *f, struct cie_info *c)
|
||
{
|
||
void *p;
|
||
int i;
|
||
|
||
c->augmentation = get_cie (f)->augmentation;
|
||
|
||
if (strcmp (c->augmentation, "") != 0
|
||
&& strcmp (c->augmentation, "eh") != 0
|
||
&& c->augmentation[0] != 'z')
|
||
return 0;
|
||
|
||
p = c->augmentation + strlen (c->augmentation) + 1;
|
||
|
||
if (strcmp (c->augmentation, "eh") == 0)
|
||
{
|
||
c->eh_ptr = read_pointer (p);
|
||
p += sizeof (void *);
|
||
}
|
||
else
|
||
c->eh_ptr = 0;
|
||
|
||
p = decode_uleb128 (p, &c->code_align);
|
||
p = decode_sleb128 (p, &c->data_align);
|
||
c->ra_regno = *(unsigned char *)p++;
|
||
|
||
/* If the augmentation starts with 'z', we now see the length of the
|
||
augmentation fields. */
|
||
if (c->augmentation[0] == 'z')
|
||
{
|
||
p = decode_uleb128 (p, &i);
|
||
p += i;
|
||
}
|
||
|
||
return p;
|
||
}
|
||
|
||
/* Decode one instruction's worth of DWARF 2 call frame information.
|
||
Used by __frame_state_for. Takes pointers P to the instruction to
|
||
decode, STATE to the current register unwind information, INFO to the
|
||
current CIE information, and PC to the current PC value. Returns a
|
||
pointer to the next instruction. */
|
||
|
||
static void *
|
||
execute_cfa_insn (void *p, struct frame_state_internal *state,
|
||
struct cie_info *info, void **pc)
|
||
{
|
||
unsigned insn = *(unsigned char *)p++;
|
||
unsigned reg;
|
||
int offset;
|
||
|
||
if (insn & DW_CFA_advance_loc)
|
||
*pc += ((insn & 0x3f) * info->code_align);
|
||
else if (insn & DW_CFA_offset)
|
||
{
|
||
reg = (insn & 0x3f);
|
||
p = decode_uleb128 (p, &offset);
|
||
offset *= info->data_align;
|
||
state->s.saved[reg] = REG_SAVED_OFFSET;
|
||
state->s.reg_or_offset[reg] = offset;
|
||
}
|
||
else if (insn & DW_CFA_restore)
|
||
{
|
||
reg = (insn & 0x3f);
|
||
state->s.saved[reg] = REG_UNSAVED;
|
||
}
|
||
else switch (insn)
|
||
{
|
||
case DW_CFA_set_loc:
|
||
*pc = read_pointer (p);
|
||
p += sizeof (void *);
|
||
break;
|
||
case DW_CFA_advance_loc1:
|
||
*pc += read_1byte (p);
|
||
p += 1;
|
||
break;
|
||
case DW_CFA_advance_loc2:
|
||
*pc += read_2byte (p);
|
||
p += 2;
|
||
break;
|
||
case DW_CFA_advance_loc4:
|
||
*pc += read_4byte (p);
|
||
p += 4;
|
||
break;
|
||
|
||
case DW_CFA_offset_extended:
|
||
p = decode_uleb128 (p, ®);
|
||
p = decode_uleb128 (p, &offset);
|
||
offset *= info->data_align;
|
||
state->s.saved[reg] = REG_SAVED_OFFSET;
|
||
state->s.reg_or_offset[reg] = offset;
|
||
break;
|
||
case DW_CFA_restore_extended:
|
||
p = decode_uleb128 (p, ®);
|
||
state->s.saved[reg] = REG_UNSAVED;
|
||
break;
|
||
|
||
case DW_CFA_undefined:
|
||
case DW_CFA_same_value:
|
||
case DW_CFA_nop:
|
||
break;
|
||
|
||
case DW_CFA_register:
|
||
{
|
||
unsigned reg2;
|
||
p = decode_uleb128 (p, ®);
|
||
p = decode_uleb128 (p, ®2);
|
||
state->s.saved[reg] = REG_SAVED_REG;
|
||
state->s.reg_or_offset[reg] = reg2;
|
||
}
|
||
break;
|
||
|
||
case DW_CFA_def_cfa:
|
||
p = decode_uleb128 (p, ®);
|
||
p = decode_uleb128 (p, &offset);
|
||
state->s.cfa_reg = reg;
|
||
state->s.cfa_offset = offset;
|
||
break;
|
||
case DW_CFA_def_cfa_register:
|
||
p = decode_uleb128 (p, ®);
|
||
state->s.cfa_reg = reg;
|
||
break;
|
||
case DW_CFA_def_cfa_offset:
|
||
p = decode_uleb128 (p, &offset);
|
||
state->s.cfa_offset = offset;
|
||
break;
|
||
|
||
case DW_CFA_remember_state:
|
||
{
|
||
struct frame_state_internal *save =
|
||
(struct frame_state_internal *)
|
||
malloc (sizeof (struct frame_state_internal));
|
||
memcpy (save, state, sizeof (struct frame_state_internal));
|
||
state->saved_state = save;
|
||
}
|
||
break;
|
||
case DW_CFA_restore_state:
|
||
{
|
||
struct frame_state_internal *save = state->saved_state;
|
||
memcpy (state, save, sizeof (struct frame_state_internal));
|
||
free (save);
|
||
}
|
||
break;
|
||
|
||
/* FIXME: Hardcoded for SPARC register window configuration. */
|
||
case DW_CFA_GNU_window_save:
|
||
for (reg = 16; reg < 32; ++reg)
|
||
{
|
||
state->s.saved[reg] = REG_SAVED_OFFSET;
|
||
state->s.reg_or_offset[reg] = (reg - 16) * sizeof (void *);
|
||
}
|
||
break;
|
||
|
||
case DW_CFA_GNU_args_size:
|
||
p = decode_uleb128 (p, &offset);
|
||
state->s.args_size = offset;
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
return p;
|
||
}
|
||
|
||
/* Called from crtbegin.o to register the unwind info for an object. */
|
||
|
||
void
|
||
__register_frame_info (void *begin, struct object *ob)
|
||
{
|
||
ob->fde_begin = begin;
|
||
|
||
ob->pc_begin = ob->pc_end = 0;
|
||
ob->fde_array = 0;
|
||
ob->count = 0;
|
||
|
||
init_object_mutex_once ();
|
||
__gthread_mutex_lock (&object_mutex);
|
||
|
||
ob->next = objects;
|
||
objects = ob;
|
||
|
||
__gthread_mutex_unlock (&object_mutex);
|
||
}
|
||
|
||
void
|
||
__register_frame (void *begin)
|
||
{
|
||
struct object *ob = (struct object *) malloc (sizeof (struct object));
|
||
__register_frame_info (begin, ob);
|
||
}
|
||
|
||
/* Similar, but BEGIN is actually a pointer to a table of unwind entries
|
||
for different translation units. Called from the file generated by
|
||
collect2. */
|
||
|
||
void
|
||
__register_frame_info_table (void *begin, struct object *ob)
|
||
{
|
||
ob->fde_begin = begin;
|
||
ob->fde_array = begin;
|
||
|
||
ob->pc_begin = ob->pc_end = 0;
|
||
ob->count = 0;
|
||
|
||
init_object_mutex_once ();
|
||
__gthread_mutex_lock (&object_mutex);
|
||
|
||
ob->next = objects;
|
||
objects = ob;
|
||
|
||
__gthread_mutex_unlock (&object_mutex);
|
||
}
|
||
|
||
void
|
||
__register_frame_table (void *begin)
|
||
{
|
||
struct object *ob = (struct object *) malloc (sizeof (struct object));
|
||
__register_frame_info_table (begin, ob);
|
||
}
|
||
|
||
/* Called from crtbegin.o to deregister the unwind info for an object. */
|
||
|
||
void *
|
||
__deregister_frame_info (void *begin)
|
||
{
|
||
struct object **p;
|
||
|
||
init_object_mutex_once ();
|
||
__gthread_mutex_lock (&object_mutex);
|
||
|
||
p = &objects;
|
||
while (*p)
|
||
{
|
||
if ((*p)->fde_begin == begin)
|
||
{
|
||
struct object *ob = *p;
|
||
*p = (*p)->next;
|
||
|
||
/* If we've run init_frame for this object, free the FDE array. */
|
||
if (ob->pc_begin)
|
||
free (ob->fde_array);
|
||
|
||
__gthread_mutex_unlock (&object_mutex);
|
||
return (void *) ob;
|
||
}
|
||
p = &((*p)->next);
|
||
}
|
||
|
||
__gthread_mutex_unlock (&object_mutex);
|
||
abort ();
|
||
}
|
||
|
||
void
|
||
__deregister_frame (void *begin)
|
||
{
|
||
free (__deregister_frame_info (begin));
|
||
}
|
||
|
||
/* Called from __throw to find the registers to restore for a given
|
||
PC_TARGET. The caller should allocate a local variable of `struct
|
||
frame_state' (declared in frame.h) and pass its address to STATE_IN. */
|
||
|
||
struct frame_state *
|
||
__frame_state_for (void *pc_target, struct frame_state *state_in)
|
||
{
|
||
fde *f;
|
||
void *insn, *end, *pc;
|
||
struct cie_info info;
|
||
struct frame_state_internal state;
|
||
|
||
f = find_fde (pc_target);
|
||
if (f == 0)
|
||
return 0;
|
||
|
||
insn = extract_cie_info (f, &info);
|
||
if (insn == 0)
|
||
return 0;
|
||
|
||
memset (&state, 0, sizeof (state));
|
||
state.s.retaddr_column = info.ra_regno;
|
||
state.s.eh_ptr = info.eh_ptr;
|
||
|
||
/* First decode all the insns in the CIE. */
|
||
end = next_fde ((fde*) get_cie (f));
|
||
while (insn < end)
|
||
insn = execute_cfa_insn (insn, &state, &info, 0);
|
||
|
||
insn = ((fde *)f) + 1;
|
||
|
||
if (info.augmentation[0] == 'z')
|
||
{
|
||
int i;
|
||
insn = decode_uleb128 (insn, &i);
|
||
insn += i;
|
||
}
|
||
|
||
/* Then the insns in the FDE up to our target PC. */
|
||
end = next_fde (f);
|
||
pc = f->pc_begin;
|
||
while (insn < end && pc <= pc_target)
|
||
insn = execute_cfa_insn (insn, &state, &info, &pc);
|
||
|
||
memcpy (state_in, &state.s, sizeof (state.s));
|
||
return state_in;
|
||
}
|
||
#endif /* DWARF2_UNWIND_INFO */
|