#include "defs.h"
#include "symtab.h"
#include "gdbtypes.h"
#include "value.h"
#include "gdbcore.h"
#include "elf/dwarf2.h"
#include "dwarf2expr.h"
static void execute_stack_op (struct dwarf_expr_context *,
gdb_byte *, gdb_byte *);
struct dwarf_expr_context *
new_dwarf_expr_context (void)
{
struct dwarf_expr_context *retval;
retval = xcalloc (1, sizeof (struct dwarf_expr_context));
retval->stack_len = 0;
retval->stack_allocated = 10;
retval->stack = xmalloc (retval->stack_allocated * sizeof (CORE_ADDR));
retval->num_pieces = 0;
retval->pieces = 0;
return retval;
}
void
free_dwarf_expr_context (struct dwarf_expr_context *ctx)
{
xfree (ctx->stack);
xfree (ctx->pieces);
xfree (ctx);
}
static void
dwarf_expr_grow_stack (struct dwarf_expr_context *ctx, size_t need)
{
if (ctx->stack_len + need > ctx->stack_allocated)
{
size_t newlen = ctx->stack_len + need + 10;
ctx->stack = xrealloc (ctx->stack,
newlen * sizeof (CORE_ADDR));
ctx->stack_allocated = newlen;
}
}
void
dwarf_expr_push (struct dwarf_expr_context *ctx, CORE_ADDR value)
{
dwarf_expr_grow_stack (ctx, 1);
ctx->stack[ctx->stack_len++] = value;
}
void
dwarf_expr_pop (struct dwarf_expr_context *ctx)
{
if (ctx->stack_len <= 0)
error (_("dwarf expression stack underflow"));
ctx->stack_len--;
}
CORE_ADDR
dwarf_expr_fetch (struct dwarf_expr_context *ctx, int n)
{
if (ctx->stack_len < n)
error (_("Asked for position %d of stack, stack only has %d elements on it."),
n, ctx->stack_len);
return ctx->stack[ctx->stack_len - (1 + n)];
}
static void
add_piece (struct dwarf_expr_context *ctx,
int in_reg, CORE_ADDR value, ULONGEST size)
{
struct dwarf_expr_piece *p;
ctx->num_pieces++;
if (ctx->pieces)
ctx->pieces = xrealloc (ctx->pieces,
(ctx->num_pieces
* sizeof (struct dwarf_expr_piece)));
else
ctx->pieces = xmalloc (ctx->num_pieces
* sizeof (struct dwarf_expr_piece));
p = &ctx->pieces[ctx->num_pieces - 1];
p->in_reg = in_reg;
p->value = value;
p->size = size;
}
void
dwarf_expr_eval (struct dwarf_expr_context *ctx, gdb_byte *addr, size_t len)
{
execute_stack_op (ctx, addr, addr + len);
}
gdb_byte *
read_uleb128 (gdb_byte *buf, gdb_byte *buf_end, ULONGEST * r)
{
unsigned shift = 0;
ULONGEST result = 0;
gdb_byte byte;
while (1)
{
if (buf >= buf_end)
error (_("read_uleb128: Corrupted DWARF expression."));
byte = *buf++;
result |= (byte & 0x7f) << shift;
if ((byte & 0x80) == 0)
break;
shift += 7;
}
*r = result;
return buf;
}
gdb_byte *
read_sleb128 (gdb_byte *buf, gdb_byte *buf_end, LONGEST * r)
{
unsigned shift = 0;
LONGEST result = 0;
gdb_byte byte;
while (1)
{
if (buf >= buf_end)
error (_("read_sleb128: Corrupted DWARF expression."));
byte = *buf++;
result |= (byte & 0x7f) << shift;
shift += 7;
if ((byte & 0x80) == 0)
break;
}
if (shift < (sizeof (*r) * 8) && (byte & 0x40) != 0)
result |= -(1 << shift);
*r = result;
return buf;
}
CORE_ADDR
dwarf2_read_address (gdb_byte *buf, gdb_byte *buf_end, int *bytes_read)
{
CORE_ADDR result;
if (buf_end - buf < TARGET_ADDR_BIT / TARGET_CHAR_BIT)
error (_("dwarf2_read_address: Corrupted DWARF expression."));
*bytes_read = TARGET_ADDR_BIT / TARGET_CHAR_BIT;
result = extract_unsigned_integer (buf, TARGET_ADDR_BIT / TARGET_CHAR_BIT);
return result;
}
static struct type *
unsigned_address_type (void)
{
switch (TARGET_ADDR_BIT / TARGET_CHAR_BIT)
{
case 2:
return builtin_type_uint16;
case 4:
return builtin_type_uint32;
case 8:
return builtin_type_uint64;
default:
internal_error (__FILE__, __LINE__,
_("Unsupported address size.\n"));
}
}
static struct type *
signed_address_type (void)
{
switch (TARGET_ADDR_BIT / TARGET_CHAR_BIT)
{
case 2:
return builtin_type_int16;
case 4:
return builtin_type_int32;
case 8:
return builtin_type_int64;
default:
internal_error (__FILE__, __LINE__,
_("Unsupported address size.\n"));
}
}
static void
execute_stack_op (struct dwarf_expr_context *ctx,
gdb_byte *op_ptr, gdb_byte *op_end)
{
ctx->in_reg = 0;
while (op_ptr < op_end)
{
enum dwarf_location_atom op = *op_ptr++;
CORE_ADDR result;
ULONGEST uoffset, reg;
LONGEST offset;
int bytes_read;
switch (op)
{
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:
result = op - DW_OP_lit0;
break;
case DW_OP_addr:
result = dwarf2_read_address (op_ptr, op_end, &bytes_read);
op_ptr += bytes_read;
break;
case DW_OP_const1u:
result = extract_unsigned_integer (op_ptr, 1);
op_ptr += 1;
break;
case DW_OP_const1s:
result = extract_signed_integer (op_ptr, 1);
op_ptr += 1;
break;
case DW_OP_const2u:
result = extract_unsigned_integer (op_ptr, 2);
op_ptr += 2;
break;
case DW_OP_const2s:
result = extract_signed_integer (op_ptr, 2);
op_ptr += 2;
break;
case DW_OP_const4u:
result = extract_unsigned_integer (op_ptr, 4);
op_ptr += 4;
break;
case DW_OP_const4s:
result = extract_signed_integer (op_ptr, 4);
op_ptr += 4;
break;
case DW_OP_const8u:
result = extract_unsigned_integer (op_ptr, 8);
op_ptr += 8;
break;
case DW_OP_const8s:
result = extract_signed_integer (op_ptr, 8);
op_ptr += 8;
break;
case DW_OP_constu:
op_ptr = read_uleb128 (op_ptr, op_end, &uoffset);
result = uoffset;
break;
case DW_OP_consts:
op_ptr = read_sleb128 (op_ptr, op_end, &offset);
result = offset;
break;
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:
if (op_ptr != op_end && *op_ptr != DW_OP_piece)
error (_("DWARF-2 expression error: DW_OP_reg operations must be "
"used either alone or in conjuction with DW_OP_piece."));
result = op - DW_OP_reg0;
ctx->in_reg = 1;
break;
case DW_OP_regx:
op_ptr = read_uleb128 (op_ptr, op_end, ®);
if (op_ptr != op_end && *op_ptr != DW_OP_piece)
error (_("DWARF-2 expression error: DW_OP_reg operations must be "
"used either alone or in conjuction with DW_OP_piece."));
result = reg;
ctx->in_reg = 1;
break;
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:
{
op_ptr = read_sleb128 (op_ptr, op_end, &offset);
result = (ctx->read_reg) (ctx->baton, op - DW_OP_breg0);
result += offset;
}
break;
case DW_OP_bregx:
{
op_ptr = read_uleb128 (op_ptr, op_end, ®);
op_ptr = read_sleb128 (op_ptr, op_end, &offset);
result = (ctx->read_reg) (ctx->baton, reg);
result += offset;
}
break;
case DW_OP_fbreg:
{
gdb_byte *datastart;
size_t datalen;
unsigned int before_stack_len;
op_ptr = read_sleb128 (op_ptr, op_end, &offset);
before_stack_len = ctx->stack_len;
(ctx->get_frame_base) (ctx->baton, &datastart, &datalen);
dwarf_expr_eval (ctx, datastart, datalen);
result = dwarf_expr_fetch (ctx, 0);
if (ctx->in_reg)
result = (ctx->read_reg) (ctx->baton, result);
result = result + offset;
ctx->stack_len = before_stack_len;
ctx->in_reg = 0;
}
break;
case DW_OP_dup:
result = dwarf_expr_fetch (ctx, 0);
break;
case DW_OP_drop:
dwarf_expr_pop (ctx);
goto no_push;
case DW_OP_pick:
offset = *op_ptr++;
result = dwarf_expr_fetch (ctx, offset);
break;
case DW_OP_over:
result = dwarf_expr_fetch (ctx, 1);
break;
case DW_OP_rot:
{
CORE_ADDR t1, t2, t3;
if (ctx->stack_len < 3)
error (_("Not enough elements for DW_OP_rot. Need 3, have %d."),
ctx->stack_len);
t1 = ctx->stack[ctx->stack_len - 1];
t2 = ctx->stack[ctx->stack_len - 2];
t3 = ctx->stack[ctx->stack_len - 3];
ctx->stack[ctx->stack_len - 1] = t2;
ctx->stack[ctx->stack_len - 2] = t3;
ctx->stack[ctx->stack_len - 3] = t1;
goto no_push;
}
case DW_OP_deref:
case DW_OP_deref_size:
case DW_OP_abs:
case DW_OP_neg:
case DW_OP_not:
case DW_OP_plus_uconst:
result = dwarf_expr_fetch (ctx, 0);
dwarf_expr_pop (ctx);
switch (op)
{
case DW_OP_deref:
{
gdb_byte *buf = alloca (TARGET_ADDR_BIT / TARGET_CHAR_BIT);
int bytes_read;
(ctx->read_mem) (ctx->baton, buf, result,
TARGET_ADDR_BIT / TARGET_CHAR_BIT);
result = dwarf2_read_address (buf,
buf + (TARGET_ADDR_BIT
/ TARGET_CHAR_BIT),
&bytes_read);
}
break;
case DW_OP_deref_size:
{
gdb_byte *buf = alloca (TARGET_ADDR_BIT / TARGET_CHAR_BIT);
int bytes_read;
(ctx->read_mem) (ctx->baton, buf, result, *op_ptr++);
result = dwarf2_read_address (buf,
buf + (TARGET_ADDR_BIT
/ TARGET_CHAR_BIT),
&bytes_read);
}
break;
case DW_OP_abs:
if ((signed int) result < 0)
result = -result;
break;
case DW_OP_neg:
result = -result;
break;
case DW_OP_not:
result = ~result;
break;
case DW_OP_plus_uconst:
op_ptr = read_uleb128 (op_ptr, op_end, ®);
result += reg;
break;
}
break;
case DW_OP_and:
case DW_OP_div:
case DW_OP_minus:
case DW_OP_mod:
case DW_OP_mul:
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_le:
case DW_OP_ge:
case DW_OP_eq:
case DW_OP_lt:
case DW_OP_gt:
case DW_OP_ne:
{
CORE_ADDR first, second;
enum exp_opcode binop;
struct value *val1, *val2;
second = dwarf_expr_fetch (ctx, 0);
dwarf_expr_pop (ctx);
first = dwarf_expr_fetch (ctx, 0);
dwarf_expr_pop (ctx);
val1 = value_from_longest (unsigned_address_type (), first);
val2 = value_from_longest (unsigned_address_type (), second);
switch (op)
{
case DW_OP_and:
binop = BINOP_BITWISE_AND;
break;
case DW_OP_div:
binop = BINOP_DIV;
break;
case DW_OP_minus:
binop = BINOP_SUB;
break;
case DW_OP_mod:
binop = BINOP_MOD;
break;
case DW_OP_mul:
binop = BINOP_MUL;
break;
case DW_OP_or:
binop = BINOP_BITWISE_IOR;
break;
case DW_OP_plus:
binop = BINOP_ADD;
break;
case DW_OP_shl:
binop = BINOP_LSH;
break;
case DW_OP_shr:
binop = BINOP_RSH;
break;
case DW_OP_shra:
binop = BINOP_RSH;
val1 = value_from_longest (signed_address_type (), first);
break;
case DW_OP_xor:
binop = BINOP_BITWISE_XOR;
break;
case DW_OP_le:
binop = BINOP_LEQ;
break;
case DW_OP_ge:
binop = BINOP_GEQ;
break;
case DW_OP_eq:
binop = BINOP_EQUAL;
break;
case DW_OP_lt:
binop = BINOP_LESS;
break;
case DW_OP_gt:
binop = BINOP_GTR;
break;
case DW_OP_ne:
binop = BINOP_NOTEQUAL;
break;
default:
internal_error (__FILE__, __LINE__,
_("Can't be reached."));
}
result = value_as_long (value_binop (val1, val2, binop));
}
break;
case DW_OP_GNU_push_tls_address:
result = dwarf_expr_fetch (ctx, 0);
dwarf_expr_pop (ctx);
result = (ctx->get_tls_address) (ctx->baton, result);
break;
case DW_OP_skip:
offset = extract_signed_integer (op_ptr, 2);
op_ptr += 2;
op_ptr += offset;
goto no_push;
case DW_OP_bra:
offset = extract_signed_integer (op_ptr, 2);
op_ptr += 2;
if (dwarf_expr_fetch (ctx, 0) != 0)
op_ptr += offset;
dwarf_expr_pop (ctx);
goto no_push;
case DW_OP_nop:
goto no_push;
case DW_OP_piece:
{
ULONGEST size;
CORE_ADDR addr_or_regnum;
op_ptr = read_uleb128 (op_ptr, op_end, &size);
addr_or_regnum = dwarf_expr_fetch (ctx, 0);
add_piece (ctx, ctx->in_reg, addr_or_regnum, size);
dwarf_expr_pop (ctx);
ctx->in_reg = 0;
}
goto no_push;
default:
error (_("Unhandled dwarf expression opcode 0x%x"), op);
}
dwarf_expr_push (ctx, result);
no_push:;
}
}