/* DWARF 2 Expression Evaluator.
- Copyright (C) 2001, 2002, 2003, 2005, 2007 Free Software Foundation, Inc.
+ Copyright (C) 2001, 2002, 2003, 2005, 2007, 2008, 2009
+ Free Software Foundation, Inc.
Contributed by Daniel Berlin (dan@dberlin.org)
This program 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 of the License, or
+ the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 51 Franklin Street, Fifth Floor,
- Boston, MA 02110-1301, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "symtab.h"
#include "gdbcore.h"
#include "elf/dwarf2.h"
#include "dwarf2expr.h"
+#include "gdb_assert.h"
/* Local prototypes. */
static void execute_stack_op (struct dwarf_expr_context *,
gdb_byte *, gdb_byte *);
-static struct type *unsigned_address_type (void);
+static struct type *unsigned_address_type (int);
/* Create a new context for the expression evaluator. */
retval->stack = xmalloc (retval->stack_allocated * sizeof (CORE_ADDR));
retval->num_pieces = 0;
retval->pieces = 0;
+ retval->max_recursion_depth = 0x100;
return retval;
}
void
dwarf_expr_eval (struct dwarf_expr_context *ctx, gdb_byte *addr, size_t len)
{
+ int old_recursion_depth = ctx->recursion_depth;
+
execute_stack_op (ctx, addr, addr + len);
+
+ /* CTX RECURSION_DEPTH becomes invalid if an exception was thrown here. */
+
+ gdb_assert (ctx->recursion_depth == old_recursion_depth);
}
/* Decode the unsigned LEB128 constant at BUF into the variable pointed to
return buf;
}
-/* Read an address from BUF, and verify that it doesn't extend past
- BUF_END. The address is returned, and *BYTES_READ is set to the
- number of bytes read from BUF. */
+/* Read an address of size ADDR_SIZE from BUF, and verify that it
+ doesn't extend past BUF_END. */
CORE_ADDR
-dwarf2_read_address (gdb_byte *buf, gdb_byte *buf_end, int *bytes_read)
+dwarf2_read_address (struct gdbarch *gdbarch, gdb_byte *buf,
+ gdb_byte *buf_end, int addr_size)
{
CORE_ADDR result;
- if (buf_end - buf < TARGET_ADDR_BIT / TARGET_CHAR_BIT)
+ if (buf_end - buf < addr_size)
error (_("dwarf2_read_address: Corrupted DWARF expression."));
- *bytes_read = TARGET_ADDR_BIT / TARGET_CHAR_BIT;
-
/* For most architectures, calling extract_unsigned_integer() alone
is sufficient for extracting an address. However, some
architectures (e.g. MIPS) use signed addresses and using
extract_unsigned_integer() will not produce a correct
- result. Turning the unsigned integer into a value and then
- decomposing that value as an address will cause
- gdbarch_integer_to_address() to be invoked for those
- architectures which require it. Thus, using value_as_address()
- will produce the correct result for both types of architectures.
-
- One concern regarding the use of values for this purpose is
- efficiency. Obviously, these extra calls will take more time to
- execute and creating a value takes more space, space which will
- have to be garbage collected at a later time. If constructing
- and then decomposing a value for this purpose proves to be too
- inefficient, then gdbarch_integer_to_address() can be called
- directly.
+ result. Make sure we invoke gdbarch_integer_to_address()
+ for those architectures which require it.
The use of `unsigned_address_type' in the code below refers to
the type of buf and has no bearing on the signedness of the
address being returned. */
- result = value_as_address (value_from_longest
- (unsigned_address_type (),
- extract_unsigned_integer
- (buf,
- TARGET_ADDR_BIT / TARGET_CHAR_BIT)));
+ if (gdbarch_integer_to_address_p (gdbarch))
+ return gdbarch_integer_to_address
+ (gdbarch, unsigned_address_type (addr_size), buf);
- return result;
+ return extract_unsigned_integer (buf, addr_size);
}
-/* Return the type of an address, for unsigned arithmetic. */
+/* Return the type of an address of size ADDR_SIZE,
+ for unsigned arithmetic. */
static struct type *
-unsigned_address_type (void)
+unsigned_address_type (int addr_size)
{
- switch (TARGET_ADDR_BIT / TARGET_CHAR_BIT)
+ switch (addr_size)
{
case 2:
return builtin_type_uint16;
}
}
-/* Return the type of an address, for signed arithmetic. */
+/* Return the type of an address of size ADDR_SIZE,
+ for signed arithmetic. */
static struct type *
-signed_address_type (void)
+signed_address_type (int addr_size)
{
- switch (TARGET_ADDR_BIT / TARGET_CHAR_BIT)
+ switch (addr_size)
{
case 2:
return builtin_type_int16;
ctx->in_reg = 0;
ctx->initialized = 1; /* Default is initialized. */
+ if (ctx->recursion_depth > ctx->max_recursion_depth)
+ error (_("DWARF-2 expression error: Loop detected (%d)."),
+ ctx->recursion_depth);
+ ctx->recursion_depth++;
+
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)
{
break;
case DW_OP_addr:
- result = dwarf2_read_address (op_ptr, op_end, &bytes_read);
- op_ptr += bytes_read;
+ result = dwarf2_read_address (ctx->gdbarch,
+ op_ptr, op_end, ctx->addr_size);
+ op_ptr += ctx->addr_size;
break;
case DW_OP_const1u:
offset = *op_ptr++;
result = dwarf_expr_fetch (ctx, offset);
break;
+
+ case DW_OP_swap:
+ {
+ CORE_ADDR t1, t2;
+
+ if (ctx->stack_len < 2)
+ error (_("Not enough elements for DW_OP_swap. Need 2, have %d."),
+ ctx->stack_len);
+ t1 = ctx->stack[ctx->stack_len - 1];
+ t2 = ctx->stack[ctx->stack_len - 2];
+ ctx->stack[ctx->stack_len - 1] = t2;
+ ctx->stack[ctx->stack_len - 2] = t1;
+ goto no_push;
+ }
case DW_OP_over:
result = dwarf_expr_fetch (ctx, 1);
{
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);
+ gdb_byte *buf = alloca (ctx->addr_size);
+ (ctx->read_mem) (ctx->baton, buf, result, ctx->addr_size);
+ result = dwarf2_read_address (ctx->gdbarch,
+ buf, buf + ctx->addr_size,
+ ctx->addr_size);
}
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);
+ int addr_size = *op_ptr++;
+ gdb_byte *buf = alloca (addr_size);
+ (ctx->read_mem) (ctx->baton, buf, result, addr_size);
+ result = dwarf2_read_address (ctx->gdbarch,
+ buf, buf + addr_size,
+ addr_size);
}
break;
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);
+ val1 = value_from_longest
+ (unsigned_address_type (ctx->addr_size), first);
+ val2 = value_from_longest
+ (unsigned_address_type (ctx->addr_size), second);
switch (op)
{
break;
case DW_OP_shra:
binop = BINOP_RSH;
- val1 = value_from_longest (signed_address_type (), first);
+ val1 = value_from_longest
+ (signed_address_type (ctx->addr_size), first);
break;
case DW_OP_xor:
binop = BINOP_BITWISE_XOR;
case DW_OP_GNU_uninit:
if (op_ptr != op_end)
- error (_("DWARF-2 expression error: DW_OP_GNU_unint must always "
+ error (_("DWARF-2 expression error: DW_OP_GNU_uninit must always "
"be the very last op."));
ctx->initialized = 0;
dwarf_expr_push (ctx, result);
no_push:;
}
+
+ ctx->recursion_depth--;
+ gdb_assert (ctx->recursion_depth >= 0);
}