/* DWARF 2 Expression Evaluator.
- Copyright (C) 2001, 2002, 2003, 2005, 2007 Free Software Foundation, Inc.
+ Copyright (C) 2001, 2002, 2003, 2005, 2007, 2008, 2009, 2010
+ 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 "gdbtypes.h"
#include "value.h"
#include "gdbcore.h"
-#include "elf/dwarf2.h"
+#include "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 (struct gdbarch *, 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;
}
xfree (ctx);
}
+/* Helper for make_cleanup_free_dwarf_expr_context. */
+
+static void
+free_dwarf_expr_context_cleanup (void *arg)
+{
+ free_dwarf_expr_context (arg);
+}
+
+/* Return a cleanup that calls free_dwarf_expr_context. */
+
+struct cleanup *
+make_cleanup_free_dwarf_expr_context (struct dwarf_expr_context *ctx)
+{
+ return make_cleanup (free_dwarf_expr_context_cleanup, ctx);
+}
+
/* Expand the memory allocated to CTX's stack to contain at least
NEED more elements than are currently used. */
{
size_t newlen = ctx->stack_len + need + 10;
ctx->stack = xrealloc (ctx->stack,
- newlen * sizeof (CORE_ADDR));
+ newlen * sizeof (struct dwarf_stack_value));
ctx->stack_allocated = newlen;
}
}
/* Push VALUE onto CTX's stack. */
void
-dwarf_expr_push (struct dwarf_expr_context *ctx, CORE_ADDR value)
+dwarf_expr_push (struct dwarf_expr_context *ctx, CORE_ADDR value,
+ int in_stack_memory)
{
+ struct dwarf_stack_value *v;
+
dwarf_expr_grow_stack (ctx, 1);
- ctx->stack[ctx->stack_len++] = value;
+ v = &ctx->stack[ctx->stack_len++];
+ v->value = value;
+ v->in_stack_memory = in_stack_memory;
}
/* Pop the top item off of CTX's stack. */
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)];
+ return ctx->stack[ctx->stack_len - (1 + n)].value;
+
+}
+
+/* Retrieve the in_stack_memory flag of the N'th item on CTX's stack. */
+
+int
+dwarf_expr_fetch_in_stack_memory (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)].in_stack_memory;
}
/* Add a new piece to CTX's piece list. */
static void
-add_piece (struct dwarf_expr_context *ctx,
- int in_reg, CORE_ADDR value, ULONGEST size)
+add_piece (struct dwarf_expr_context *ctx, ULONGEST size)
{
struct dwarf_expr_piece *p;
* sizeof (struct dwarf_expr_piece));
p = &ctx->pieces[ctx->num_pieces - 1];
- p->in_reg = in_reg;
- p->value = value;
+ p->location = ctx->location;
p->size = size;
+ if (p->location == DWARF_VALUE_LITERAL)
+ {
+ p->v.literal.data = ctx->data;
+ p->v.literal.length = ctx->len;
+ }
+ else
+ {
+ p->v.expr.value = dwarf_expr_fetch (ctx, 0);
+ p->v.expr.in_stack_memory = dwarf_expr_fetch_in_stack_memory (ctx, 0);
+ }
}
/* Evaluate the expression at ADDR (LEN bytes long) using the context
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)
{
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
CORE_ADDR result;
- if (buf_end - buf < gdbarch_addr_bit (current_gdbarch) / TARGET_CHAR_BIT)
+ if (buf_end - buf < addr_size)
error (_("dwarf2_read_address: Corrupted DWARF expression."));
- *bytes_read = gdbarch_addr_bit (current_gdbarch) / 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,
- gdbarch_addr_bit (current_gdbarch)
- / TARGET_CHAR_BIT)));
+ if (gdbarch_integer_to_address_p (gdbarch))
+ return gdbarch_integer_to_address
+ (gdbarch, unsigned_address_type (gdbarch, addr_size), buf);
- return result;
+ return extract_unsigned_integer (buf, addr_size, byte_order);
}
-/* 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 (struct gdbarch *gdbarch, int addr_size)
{
- switch (gdbarch_addr_bit (current_gdbarch) / TARGET_CHAR_BIT)
+ switch (addr_size)
{
case 2:
- return builtin_type_uint16;
+ return builtin_type (gdbarch)->builtin_uint16;
case 4:
- return builtin_type_uint32;
+ return builtin_type (gdbarch)->builtin_uint32;
case 8:
- return builtin_type_uint64;
+ return builtin_type (gdbarch)->builtin_uint64;
default:
internal_error (__FILE__, __LINE__,
_("Unsupported address size.\n"));
}
}
-/* 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 (struct gdbarch *gdbarch, int addr_size)
{
- switch (gdbarch_addr_bit (current_gdbarch) / TARGET_CHAR_BIT)
+ switch (addr_size)
{
case 2:
- return builtin_type_int16;
+ return builtin_type (gdbarch)->builtin_int16;
case 4:
- return builtin_type_int32;
+ return builtin_type (gdbarch)->builtin_int32;
case 8:
- return builtin_type_int64;
+ return builtin_type (gdbarch)->builtin_int64;
default:
internal_error (__FILE__, __LINE__,
_("Unsupported address size.\n"));
}
}
\f
+
+/* Check that the current operator is either at the end of an
+ expression, or that it is followed by a composition operator. */
+
+static void
+require_composition (gdb_byte *op_ptr, gdb_byte *op_end, const char *op_name)
+{
+ /* It seems like DW_OP_GNU_uninit should be handled here. However,
+ it doesn't seem to make sense for DW_OP_*_value, and it was not
+ checked at the other place that this function is called. */
+ if (op_ptr != op_end && *op_ptr != DW_OP_piece && *op_ptr != DW_OP_bit_piece)
+ error (_("DWARF-2 expression error: `%s' operations must be "
+ "used either alone or in conjuction with DW_OP_piece "
+ "or DW_OP_bit_piece."),
+ op_name);
+}
+
/* The engine for the expression evaluator. Using the context in CTX,
evaluate the expression between OP_PTR and OP_END. */
execute_stack_op (struct dwarf_expr_context *ctx,
gdb_byte *op_ptr, gdb_byte *op_end)
{
- ctx->in_reg = 0;
+ enum bfd_endian byte_order = gdbarch_byte_order (ctx->gdbarch);
+ ctx->location = DWARF_VALUE_MEMORY;
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;
+ /* Assume the value is not in stack memory.
+ Code that knows otherwise sets this to 1.
+ Some arithmetic on stack addresses can probably be assumed to still
+ be a stack address, but we skip this complication for now.
+ This is just an optimization, so it's always ok to punt
+ and leave this as 0. */
+ int in_stack_memory = 0;
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:
- result = extract_unsigned_integer (op_ptr, 1);
+ result = extract_unsigned_integer (op_ptr, 1, byte_order);
op_ptr += 1;
break;
case DW_OP_const1s:
- result = extract_signed_integer (op_ptr, 1);
+ result = extract_signed_integer (op_ptr, 1, byte_order);
op_ptr += 1;
break;
case DW_OP_const2u:
- result = extract_unsigned_integer (op_ptr, 2);
+ result = extract_unsigned_integer (op_ptr, 2, byte_order);
op_ptr += 2;
break;
case DW_OP_const2s:
- result = extract_signed_integer (op_ptr, 2);
+ result = extract_signed_integer (op_ptr, 2, byte_order);
op_ptr += 2;
break;
case DW_OP_const4u:
- result = extract_unsigned_integer (op_ptr, 4);
+ result = extract_unsigned_integer (op_ptr, 4, byte_order);
op_ptr += 4;
break;
case DW_OP_const4s:
- result = extract_signed_integer (op_ptr, 4);
+ result = extract_signed_integer (op_ptr, 4, byte_order);
op_ptr += 4;
break;
case DW_OP_const8u:
- result = extract_unsigned_integer (op_ptr, 8);
+ result = extract_unsigned_integer (op_ptr, 8, byte_order);
op_ptr += 8;
break;
case DW_OP_const8s:
- result = extract_signed_integer (op_ptr, 8);
+ result = extract_signed_integer (op_ptr, 8, byte_order);
op_ptr += 8;
break;
case DW_OP_constu:
"used either alone or in conjuction with DW_OP_piece."));
result = op - DW_OP_reg0;
- ctx->in_reg = 1;
-
+ ctx->location = DWARF_VALUE_REGISTER;
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."));
+ require_composition (op_ptr, op_end, "DW_OP_regx");
result = reg;
- ctx->in_reg = 1;
+ ctx->location = DWARF_VALUE_REGISTER;
break;
+ case DW_OP_implicit_value:
+ {
+ ULONGEST len;
+ op_ptr = read_uleb128 (op_ptr, op_end, &len);
+ if (op_ptr + len > op_end)
+ error (_("DW_OP_implicit_value: too few bytes available."));
+ ctx->len = len;
+ ctx->data = op_ptr;
+ ctx->location = DWARF_VALUE_LITERAL;
+ op_ptr += len;
+ require_composition (op_ptr, op_end, "DW_OP_implicit_value");
+ }
+ goto no_push;
+
+ case DW_OP_stack_value:
+ ctx->location = DWARF_VALUE_STACK;
+ require_composition (op_ptr, op_end, "DW_OP_stack_value");
+ goto no_push;
+
case DW_OP_breg0:
case DW_OP_breg1:
case DW_OP_breg2:
specific this_base method. */
(ctx->get_frame_base) (ctx->baton, &datastart, &datalen);
dwarf_expr_eval (ctx, datastart, datalen);
+ if (ctx->location == DWARF_VALUE_LITERAL
+ || ctx->location == DWARF_VALUE_STACK)
+ error (_("Not implemented: computing frame base using explicit value operator"));
result = dwarf_expr_fetch (ctx, 0);
- if (ctx->in_reg)
+ if (ctx->location == DWARF_VALUE_REGISTER)
result = (ctx->read_reg) (ctx->baton, result);
result = result + offset;
+ in_stack_memory = 1;
ctx->stack_len = before_stack_len;
- ctx->in_reg = 0;
+ ctx->location = DWARF_VALUE_MEMORY;
}
break;
+
case DW_OP_dup:
result = dwarf_expr_fetch (ctx, 0);
+ in_stack_memory = dwarf_expr_fetch_in_stack_memory (ctx, 0);
break;
case DW_OP_drop:
case DW_OP_pick:
offset = *op_ptr++;
result = dwarf_expr_fetch (ctx, offset);
+ in_stack_memory = dwarf_expr_fetch_in_stack_memory (ctx, offset);
break;
+
+ case DW_OP_swap:
+ {
+ struct dwarf_stack_value 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);
+ in_stack_memory = dwarf_expr_fetch_in_stack_memory (ctx, 1);
break;
case DW_OP_rot:
{
- CORE_ADDR t1, t2, t3;
+ struct dwarf_stack_value t1, t2, t3;
if (ctx->stack_len < 3)
error (_("Not enough elements for DW_OP_rot. Need 3, have %d."),
{
case DW_OP_deref:
{
- gdb_byte *buf = alloca (gdbarch_addr_bit (current_gdbarch)
- / TARGET_CHAR_BIT);
- int bytes_read;
-
- (ctx->read_mem) (ctx->baton, buf, result,
- gdbarch_addr_bit (current_gdbarch)
- / TARGET_CHAR_BIT);
- result = dwarf2_read_address (buf,
- buf + (gdbarch_addr_bit
- (current_gdbarch)
- / 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 (gdbarch_addr_bit (current_gdbarch)
- / TARGET_CHAR_BIT);
- int bytes_read;
-
- (ctx->read_mem) (ctx->baton, buf, result, *op_ptr++);
- result = dwarf2_read_address (buf,
- buf + (gdbarch_addr_bit
- (current_gdbarch)
- / 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;
CORE_ADDR first, second;
enum exp_opcode binop;
struct value *val1, *val2;
+ struct type *stype, *utype;
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);
+ utype = unsigned_address_type (ctx->gdbarch, ctx->addr_size);
+ stype = signed_address_type (ctx->gdbarch, ctx->addr_size);
+ val1 = value_from_longest (utype, first);
+ val2 = value_from_longest (utype, second);
switch (op)
{
break;
case DW_OP_shra:
binop = BINOP_RSH;
- val1 = value_from_longest (signed_address_type (), first);
+ val1 = value_from_longest (stype, first);
break;
case DW_OP_xor:
binop = BINOP_BITWISE_XOR;
}
break;
+ case DW_OP_call_frame_cfa:
+ result = (ctx->get_frame_cfa) (ctx->baton);
+ in_stack_memory = 1;
+ break;
+
case DW_OP_GNU_push_tls_address:
/* Variable is at a constant offset in the thread-local
storage block into the objfile for the current thread and
break;
case DW_OP_skip:
- offset = extract_signed_integer (op_ptr, 2);
+ offset = extract_signed_integer (op_ptr, 2, byte_order);
op_ptr += 2;
op_ptr += offset;
goto no_push;
case DW_OP_bra:
- offset = extract_signed_integer (op_ptr, 2);
+ offset = extract_signed_integer (op_ptr, 2, byte_order);
op_ptr += 2;
if (dwarf_expr_fetch (ctx, 0) != 0)
op_ptr += offset;
case DW_OP_piece:
{
ULONGEST size;
- CORE_ADDR addr_or_regnum;
/* Record the piece. */
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);
+ add_piece (ctx, size);
- /* Pop off the address/regnum, and clear the in_reg flag. */
- dwarf_expr_pop (ctx);
- ctx->in_reg = 0;
+ /* Pop off the address/regnum, and reset the location
+ type. */
+ if (ctx->location != DWARF_VALUE_LITERAL)
+ dwarf_expr_pop (ctx);
+ ctx->location = DWARF_VALUE_MEMORY;
}
goto no_push;
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;
}
/* Most things push a result value. */
- dwarf_expr_push (ctx, result);
+ dwarf_expr_push (ctx, result, in_stack_memory);
no_push:;
}
+
+ ctx->recursion_depth--;
+ gdb_assert (ctx->recursion_depth >= 0);
}
projects / deliverable / binutils-gdb.git / blobdiff