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freebsd/lib/libdwarf/dwarf_loc.c
John Birrell 6433849359 Add a BSD licensed DWARF library for use by the DTrace clients.
The API for this library is deliberately different to the GPL'd
libdwarf to avoid licensing problems.
2008-05-22 02:14:23 +00:00

614 lines
12 KiB
C

/*-
* Copyright (c) 2007 John Birrell (jb@freebsd.org)
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <stdlib.h>
#include "_libdwarf.h"
static int64_t
dwarf_decode_sleb128(uint8_t **dp)
{
int64_t ret = 0;
uint8_t b;
int shift = 0;
uint8_t *src = *dp;
do {
b = *src++;
ret |= ((b & 0x7f) << shift);
shift += 7;
} while ((b & 0x80) != 0);
if (shift < 32 && (b & 0x40) != 0)
ret |= (-1 << shift);
*dp = src;
return ret;
}
static uint64_t
dwarf_decode_uleb128(uint8_t **dp)
{
uint64_t ret = 0;
uint8_t b;
int shift = 0;
uint8_t *src = *dp;
do {
b = *src++;
ret |= ((b & 0x7f) << shift);
shift += 7;
} while ((b & 0x80) != 0);
*dp = src;
return ret;
}
/*
* Given an array of bytes of length 'len' representing a
* DWARF expression, compute the number of operations based
* on there being one byte describing the operation and
* zero or more bytes of operands as defined in the standard
* for each operation type.
*/
int
dwarf_op_num(uint8_t pointer_size, uint8_t *p, int len)
{
int count = 0;
int64_t sval;
uint64_t uval;
uint8_t *last = p + len;
/*
* Process each byte. If an error occurs, then the
* count will be set to -1.
*/
while (p < last && count >= 0) {
count++;
switch (*p++) {
/* Operations with no operands. */
case DW_OP_deref:
case DW_OP_reg0:
case DW_OP_reg1:
case DW_OP_reg2:
case DW_OP_reg3:
case DW_OP_reg4:
case DW_OP_reg5:
case DW_OP_reg6:
case DW_OP_reg7:
case DW_OP_reg8:
case DW_OP_reg9:
case DW_OP_reg10:
case DW_OP_reg11:
case DW_OP_reg12:
case DW_OP_reg13:
case DW_OP_reg14:
case DW_OP_reg15:
case DW_OP_reg16:
case DW_OP_reg17:
case DW_OP_reg18:
case DW_OP_reg19:
case DW_OP_reg20:
case DW_OP_reg21:
case DW_OP_reg22:
case DW_OP_reg23:
case DW_OP_reg24:
case DW_OP_reg25:
case DW_OP_reg26:
case DW_OP_reg27:
case DW_OP_reg28:
case DW_OP_reg29:
case DW_OP_reg30:
case DW_OP_reg31:
case DW_OP_lit0:
case DW_OP_lit1:
case DW_OP_lit2:
case DW_OP_lit3:
case DW_OP_lit4:
case DW_OP_lit5:
case DW_OP_lit6:
case DW_OP_lit7:
case DW_OP_lit8:
case DW_OP_lit9:
case DW_OP_lit10:
case DW_OP_lit11:
case DW_OP_lit12:
case DW_OP_lit13:
case DW_OP_lit14:
case DW_OP_lit15:
case DW_OP_lit16:
case DW_OP_lit17:
case DW_OP_lit18:
case DW_OP_lit19:
case DW_OP_lit20:
case DW_OP_lit21:
case DW_OP_lit22:
case DW_OP_lit23:
case DW_OP_lit24:
case DW_OP_lit25:
case DW_OP_lit26:
case DW_OP_lit27:
case DW_OP_lit28:
case DW_OP_lit29:
case DW_OP_lit30:
case DW_OP_lit31:
case DW_OP_dup:
case DW_OP_drop:
case DW_OP_over:
case DW_OP_swap:
case DW_OP_rot:
case DW_OP_xderef:
case DW_OP_abs:
case DW_OP_and:
case DW_OP_div:
case DW_OP_minus:
case DW_OP_mod:
case DW_OP_mul:
case DW_OP_neg:
case DW_OP_not:
case DW_OP_or:
case DW_OP_plus:
case DW_OP_shl:
case DW_OP_shr:
case DW_OP_shra:
case DW_OP_xor:
case DW_OP_eq:
case DW_OP_ge:
case DW_OP_gt:
case DW_OP_le:
case DW_OP_lt:
case DW_OP_ne:
case DW_OP_nop:
break;
/* Operations with 1-byte operands. */
case DW_OP_const1u:
case DW_OP_const1s:
case DW_OP_pick:
case DW_OP_deref_size:
case DW_OP_xderef_size:
p++;
break;
/* Operations with 2-byte operands. */
case DW_OP_const2u:
case DW_OP_const2s:
case DW_OP_bra:
case DW_OP_skip:
p += 2;
break;
/* Operations with 4-byte operands. */
case DW_OP_const4u:
case DW_OP_const4s:
p += 4;
break;
/* Operations with 8-byte operands. */
case DW_OP_const8u:
case DW_OP_const8s:
p += 8;
break;
/* Operations with an unsigned LEB128 operand. */
case DW_OP_constu:
case DW_OP_plus_uconst:
case DW_OP_regx:
case DW_OP_piece:
uval = dwarf_decode_sleb128(&p);
break;
/* Operations with a signed LEB128 operand. */
case DW_OP_consts:
case DW_OP_breg0:
case DW_OP_breg1:
case DW_OP_breg2:
case DW_OP_breg3:
case DW_OP_breg4:
case DW_OP_breg5:
case DW_OP_breg6:
case DW_OP_breg7:
case DW_OP_breg8:
case DW_OP_breg9:
case DW_OP_breg10:
case DW_OP_breg11:
case DW_OP_breg12:
case DW_OP_breg13:
case DW_OP_breg14:
case DW_OP_breg15:
case DW_OP_breg16:
case DW_OP_breg17:
case DW_OP_breg18:
case DW_OP_breg19:
case DW_OP_breg20:
case DW_OP_breg21:
case DW_OP_breg22:
case DW_OP_breg23:
case DW_OP_breg24:
case DW_OP_breg25:
case DW_OP_breg26:
case DW_OP_breg27:
case DW_OP_breg28:
case DW_OP_breg29:
case DW_OP_breg30:
case DW_OP_breg31:
case DW_OP_fbreg:
sval = dwarf_decode_sleb128(&p);
break;
/*
* Operations with an unsigned LEB128 operand
* followed by a signed LEB128 operand.
*/
case DW_OP_bregx:
uval = dwarf_decode_uleb128(&p);
sval = dwarf_decode_sleb128(&p);
break;
/* Target address size operand. */
case DW_OP_addr:
p += pointer_size;
break;
/* All other operations cause an error. */
default:
count = -1;
break;
}
}
return count;
}
static int
dwarf_loc_fill(Dwarf_Locdesc *lbuf, uint8_t pointer_size, uint8_t *p, int len)
{
int count = 0;
int ret = DWARF_E_NONE;
uint64_t operand1;
uint64_t operand2;
uint8_t *last = p + len;
/*
* Process each byte. If an error occurs, then the
* count will be set to -1.
*/
while (p < last && ret == DWARF_E_NONE) {
operand1 = 0;
operand2 = 0;
lbuf->ld_s[count].lr_atom = *p;
switch (*p++) {
/* Operations with no operands. */
case DW_OP_deref:
case DW_OP_reg0:
case DW_OP_reg1:
case DW_OP_reg2:
case DW_OP_reg3:
case DW_OP_reg4:
case DW_OP_reg5:
case DW_OP_reg6:
case DW_OP_reg7:
case DW_OP_reg8:
case DW_OP_reg9:
case DW_OP_reg10:
case DW_OP_reg11:
case DW_OP_reg12:
case DW_OP_reg13:
case DW_OP_reg14:
case DW_OP_reg15:
case DW_OP_reg16:
case DW_OP_reg17:
case DW_OP_reg18:
case DW_OP_reg19:
case DW_OP_reg20:
case DW_OP_reg21:
case DW_OP_reg22:
case DW_OP_reg23:
case DW_OP_reg24:
case DW_OP_reg25:
case DW_OP_reg26:
case DW_OP_reg27:
case DW_OP_reg28:
case DW_OP_reg29:
case DW_OP_reg30:
case DW_OP_reg31:
case DW_OP_lit0:
case DW_OP_lit1:
case DW_OP_lit2:
case DW_OP_lit3:
case DW_OP_lit4:
case DW_OP_lit5:
case DW_OP_lit6:
case DW_OP_lit7:
case DW_OP_lit8:
case DW_OP_lit9:
case DW_OP_lit10:
case DW_OP_lit11:
case DW_OP_lit12:
case DW_OP_lit13:
case DW_OP_lit14:
case DW_OP_lit15:
case DW_OP_lit16:
case DW_OP_lit17:
case DW_OP_lit18:
case DW_OP_lit19:
case DW_OP_lit20:
case DW_OP_lit21:
case DW_OP_lit22:
case DW_OP_lit23:
case DW_OP_lit24:
case DW_OP_lit25:
case DW_OP_lit26:
case DW_OP_lit27:
case DW_OP_lit28:
case DW_OP_lit29:
case DW_OP_lit30:
case DW_OP_lit31:
case DW_OP_dup:
case DW_OP_drop:
case DW_OP_over:
case DW_OP_swap:
case DW_OP_rot:
case DW_OP_xderef:
case DW_OP_abs:
case DW_OP_and:
case DW_OP_div:
case DW_OP_minus:
case DW_OP_mod:
case DW_OP_mul:
case DW_OP_neg:
case DW_OP_not:
case DW_OP_or:
case DW_OP_plus:
case DW_OP_shl:
case DW_OP_shr:
case DW_OP_shra:
case DW_OP_xor:
case DW_OP_eq:
case DW_OP_ge:
case DW_OP_gt:
case DW_OP_le:
case DW_OP_lt:
case DW_OP_ne:
case DW_OP_nop:
break;
/* Operations with 1-byte operands. */
case DW_OP_const1u:
case DW_OP_const1s:
case DW_OP_pick:
case DW_OP_deref_size:
case DW_OP_xderef_size:
operand1 = *p++;
break;
/* Operations with 2-byte operands. */
case DW_OP_const2u:
case DW_OP_const2s:
case DW_OP_bra:
case DW_OP_skip:
p += 2;
break;
/* Operations with 4-byte operands. */
case DW_OP_const4u:
case DW_OP_const4s:
p += 4;
break;
/* Operations with 8-byte operands. */
case DW_OP_const8u:
case DW_OP_const8s:
p += 8;
break;
/* Operations with an unsigned LEB128 operand. */
case DW_OP_constu:
case DW_OP_plus_uconst:
case DW_OP_regx:
case DW_OP_piece:
operand1 = dwarf_decode_sleb128(&p);
break;
/* Operations with a signed LEB128 operand. */
case DW_OP_consts:
case DW_OP_breg0:
case DW_OP_breg1:
case DW_OP_breg2:
case DW_OP_breg3:
case DW_OP_breg4:
case DW_OP_breg5:
case DW_OP_breg6:
case DW_OP_breg7:
case DW_OP_breg8:
case DW_OP_breg9:
case DW_OP_breg10:
case DW_OP_breg11:
case DW_OP_breg12:
case DW_OP_breg13:
case DW_OP_breg14:
case DW_OP_breg15:
case DW_OP_breg16:
case DW_OP_breg17:
case DW_OP_breg18:
case DW_OP_breg19:
case DW_OP_breg20:
case DW_OP_breg21:
case DW_OP_breg22:
case DW_OP_breg23:
case DW_OP_breg24:
case DW_OP_breg25:
case DW_OP_breg26:
case DW_OP_breg27:
case DW_OP_breg28:
case DW_OP_breg29:
case DW_OP_breg30:
case DW_OP_breg31:
case DW_OP_fbreg:
operand1 = dwarf_decode_sleb128(&p);
break;
/*
* Operations with an unsigned LEB128 operand
* followed by a signed LEB128 operand.
*/
case DW_OP_bregx:
operand1 = dwarf_decode_uleb128(&p);
operand2 = dwarf_decode_sleb128(&p);
break;
/* Target address size operand. */
case DW_OP_addr:
p += pointer_size;
break;
/* All other operations cause an error. */
default:
break;
}
lbuf->ld_s[count].lr_number = operand1;
lbuf->ld_s[count].lr_number2 = operand2;
count++;
}
return ret;
}
int
dwarf_locdesc(Dwarf_Die die, uint64_t attr, Dwarf_Locdesc **llbuf, Dwarf_Signed *lenp, Dwarf_Error *err)
{
Dwarf_AttrValue av;
Dwarf_Locdesc *lbuf;
int num;
int ret = DWARF_E_NONE;
if (err == NULL)
return DWARF_E_ERROR;
if (die == NULL || llbuf == NULL || lenp == NULL) {
DWARF_SET_ERROR(err, DWARF_E_ARGUMENT);
return DWARF_E_ARGUMENT;
}
if ((av = dwarf_attrval_find(die, attr)) == NULL) {
DWARF_SET_ERROR(err, DWARF_E_NO_ENTRY);
ret = DWARF_E_NO_ENTRY;
} else if ((lbuf = calloc(sizeof(Dwarf_Locdesc), 1)) == NULL) {
DWARF_SET_ERROR(err, DWARF_E_MEMORY);
ret = DWARF_E_MEMORY;
} else {
*lenp = 0;
switch (av->av_form) {
case DW_FORM_block:
case DW_FORM_block1:
case DW_FORM_block2:
case DW_FORM_block4:
/* Compute the number of locations: */
if ((num = dwarf_op_num(die->die_cu->cu_pointer_size,
av->u[1].u8p, av->u[0].u64)) < 0) {
DWARF_SET_ERROR(err, DWARF_E_INVALID_EXPR);
ret = DWARF_E_INVALID_EXPR;
/* Allocate an array of location structures. */
} else if ((lbuf->ld_s =
calloc(sizeof(Dwarf_Loc), num)) == NULL) {
DWARF_SET_ERROR(err, DWARF_E_MEMORY);
ret = DWARF_E_MEMORY;
/* Fill the array of location structures. */
} else if ((ret = dwarf_loc_fill(lbuf,
die->die_cu->cu_pointer_size,
av->u[1].u8p, av->u[0].u64)) != DWARF_E_NONE) {
free(lbuf->ld_s);
} else
/* Only one descriptor is returned. */
*lenp = 1;
break;
default:
printf("%s(%d): form %s not handled\n",__func__,
__LINE__,get_form_desc(av->av_form));
DWARF_SET_ERROR(err, DWARF_E_NOT_IMPLEMENTED);
ret = DWARF_E_ERROR;
}
if (ret == DWARF_E_NONE) {
*llbuf = lbuf;
} else
free(lbuf);
}
return ret;
}
int
dwarf_locdesc_free(Dwarf_Locdesc *lbuf, Dwarf_Error *err)
{
if (err == NULL)
return DWARF_E_ERROR;
if (lbuf == NULL) {
DWARF_SET_ERROR(err, DWARF_E_ARGUMENT);
return DWARF_E_ARGUMENT;
}
if (lbuf->ld_s != NULL)
free(lbuf->ld_s);
free(lbuf);
return DWARF_E_NONE;
}