/* DWARF 2 location expression support for GDB.
- Copyright (C) 2003, 2005, 2007 Free Software Foundation, Inc.
+ Copyright (C) 2003, 2005, 2007, 2008, 2009, 2010
+ Free Software Foundation, Inc.
Contributed by Daniel Jacobowitz, MontaVista Software, Inc.
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 (at
- your option) any later version.
+ 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, 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.
+ This program 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 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 "ui-out.h"
#include "regcache.h"
#include "objfiles.h"
#include "exceptions.h"
+#include "block.h"
-#include "elf/dwarf2.h"
+#include "dwarf2.h"
#include "dwarf2expr.h"
#include "dwarf2loc.h"
+#include "dwarf2-frame.h"
#include "gdb_string.h"
+#include "gdb_assert.h"
-#ifndef DWARF2_REG_TO_REGNUM
-#define DWARF2_REG_TO_REGNUM(REG) (REG)
-#endif
+static void
+dwarf_expr_frame_base_1 (struct symbol *framefunc, CORE_ADDR pc,
+ const gdb_byte **start, size_t *length);
/* A helper function for dealing with location lists. Given a
symbol baton (BATON) and a pc value (PC), find the appropriate
For now, only return the first matching location expression; there
can be more than one in the list. */
-static gdb_byte *
+static const gdb_byte *
find_location_expression (struct dwarf2_loclist_baton *baton,
size_t *locexpr_length, CORE_ADDR pc)
{
CORE_ADDR low, high;
- gdb_byte *loc_ptr, *buf_end;
+ const gdb_byte *loc_ptr, *buf_end;
int length;
- unsigned int addr_size = TARGET_ADDR_BIT / TARGET_CHAR_BIT;
+ struct objfile *objfile = dwarf2_per_cu_objfile (baton->per_cu);
+ struct gdbarch *gdbarch = get_objfile_arch (objfile);
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ unsigned int addr_size = dwarf2_per_cu_addr_size (baton->per_cu);
CORE_ADDR base_mask = ~(~(CORE_ADDR)1 << (addr_size * 8 - 1));
/* Adjust base_address for relocatable objects. */
- CORE_ADDR base_offset = ANOFFSET (baton->objfile->section_offsets,
- SECT_OFF_TEXT (baton->objfile));
+ CORE_ADDR base_offset = ANOFFSET (objfile->section_offsets,
+ SECT_OFF_TEXT (objfile));
CORE_ADDR base_address = baton->base_address + base_offset;
loc_ptr = baton->data;
while (1)
{
- low = dwarf2_read_address (loc_ptr, buf_end, &length);
- loc_ptr += length;
- high = dwarf2_read_address (loc_ptr, buf_end, &length);
- loc_ptr += length;
+ if (buf_end - loc_ptr < 2 * addr_size)
+ error (_("find_location_expression: Corrupted DWARF expression."));
- /* An end-of-list entry. */
- if (low == 0 && high == 0)
- return NULL;
+ low = extract_unsigned_integer (loc_ptr, addr_size, byte_order);
+ loc_ptr += addr_size;
/* A base-address-selection entry. */
- if ((low & base_mask) == base_mask)
+ if (low == base_mask)
{
- base_address = high;
+ base_address = dwarf2_read_address (gdbarch,
+ loc_ptr, buf_end, addr_size);
+ loc_ptr += addr_size;
continue;
}
+ high = extract_unsigned_integer (loc_ptr, addr_size, byte_order);
+ loc_ptr += addr_size;
+
+ /* An end-of-list entry. */
+ if (low == 0 && high == 0)
+ return NULL;
+
/* Otherwise, a location expression entry. */
low += base_address;
high += base_address;
- length = extract_unsigned_integer (loc_ptr, 2);
+ length = extract_unsigned_integer (loc_ptr, 2, byte_order);
loc_ptr += 2;
if (pc >= low && pc < high)
dwarf_expr_read_reg (void *baton, int dwarf_regnum)
{
struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton;
+ struct gdbarch *gdbarch = get_frame_arch (debaton->frame);
CORE_ADDR result;
int regnum;
- regnum = DWARF2_REG_TO_REGNUM (dwarf_regnum);
- result = address_from_register (builtin_type_void_data_ptr,
+ regnum = gdbarch_dwarf2_reg_to_regnum (gdbarch, dwarf_regnum);
+ result = address_from_register (builtin_type (gdbarch)->builtin_data_ptr,
regnum, debaton->frame);
return result;
}
describing the frame base. Return a pointer to it in START and
its length in LENGTH. */
static void
-dwarf_expr_frame_base (void *baton, gdb_byte **start, size_t * length)
+dwarf_expr_frame_base (void *baton, const gdb_byte **start, size_t * length)
{
/* FIXME: cagney/2003-03-26: This code should be using
get_frame_base_address(), and then implement a dwarf2 specific
struct symbol *framefunc;
struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton;
- framefunc = get_frame_function (debaton->frame);
+ /* Use block_linkage_function, which returns a real (not inlined)
+ function, instead of get_frame_function, which may return an
+ inlined function. */
+ framefunc = block_linkage_function (get_frame_block (debaton->frame, NULL));
+
+ /* If we found a frame-relative symbol then it was certainly within
+ some function associated with a frame. If we can't find the frame,
+ something has gone wrong. */
+ gdb_assert (framefunc != NULL);
- if (SYMBOL_OPS (framefunc) == &dwarf2_loclist_funcs)
+ dwarf_expr_frame_base_1 (framefunc,
+ get_frame_address_in_block (debaton->frame),
+ start, length);
+}
+
+static void
+dwarf_expr_frame_base_1 (struct symbol *framefunc, CORE_ADDR pc,
+ const gdb_byte **start, size_t *length)
+{
+ if (SYMBOL_LOCATION_BATON (framefunc) == NULL)
+ *start = NULL;
+ else if (SYMBOL_COMPUTED_OPS (framefunc) == &dwarf2_loclist_funcs)
{
struct dwarf2_loclist_baton *symbaton;
- struct frame_info *frame = debaton->frame;
symbaton = SYMBOL_LOCATION_BATON (framefunc);
- *start = find_location_expression (symbaton, length,
- get_frame_address_in_block (frame));
+ *start = find_location_expression (symbaton, length, pc);
}
else
{
struct dwarf2_locexpr_baton *symbaton;
+
symbaton = SYMBOL_LOCATION_BATON (framefunc);
- *length = symbaton->size;
- *start = symbaton->data;
+ if (symbaton != NULL)
+ {
+ *length = symbaton->size;
+ *start = symbaton->data;
+ }
+ else
+ *start = NULL;
}
if (*start == NULL)
SYMBOL_NATURAL_NAME (framefunc));
}
+/* Helper function for dwarf2_evaluate_loc_desc. Computes the CFA for
+ the frame in BATON. */
+
+static CORE_ADDR
+dwarf_expr_frame_cfa (void *baton)
+{
+ struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton;
+
+ return dwarf2_frame_cfa (debaton->frame);
+}
+
/* Using the objfile specified in BATON, find the address for the
current thread's thread-local storage with offset OFFSET. */
static CORE_ADDR
return target_translate_tls_address (debaton->objfile, offset);
}
+struct piece_closure
+{
+ /* Reference count. */
+ int refc;
+
+ /* The number of pieces used to describe this variable. */
+ int n_pieces;
+
+ /* The target address size, used only for DWARF_VALUE_STACK. */
+ int addr_size;
+
+ /* The pieces themselves. */
+ struct dwarf_expr_piece *pieces;
+};
+
+/* Allocate a closure for a value formed from separately-described
+ PIECES. */
+
+static struct piece_closure *
+allocate_piece_closure (int n_pieces, struct dwarf_expr_piece *pieces,
+ int addr_size)
+{
+ struct piece_closure *c = XZALLOC (struct piece_closure);
+
+ c->refc = 1;
+ c->n_pieces = n_pieces;
+ c->addr_size = addr_size;
+ c->pieces = XCALLOC (n_pieces, struct dwarf_expr_piece);
+
+ memcpy (c->pieces, pieces, n_pieces * sizeof (struct dwarf_expr_piece));
+
+ return c;
+}
+
+/* The lowest-level function to extract bits from a byte buffer.
+ SOURCE is the buffer. It is updated if we read to the end of a
+ byte.
+ SOURCE_OFFSET_BITS is the offset of the first bit to read. It is
+ updated to reflect the number of bits actually read.
+ NBITS is the number of bits we want to read. It is updated to
+ reflect the number of bits actually read. This function may read
+ fewer bits.
+ BITS_BIG_ENDIAN is taken directly from gdbarch.
+ This function returns the extracted bits. */
+
+static unsigned int
+extract_bits_primitive (const gdb_byte **source,
+ unsigned int *source_offset_bits,
+ int *nbits, int bits_big_endian)
+{
+ unsigned int avail, mask, datum;
+
+ gdb_assert (*source_offset_bits < 8);
+
+ avail = 8 - *source_offset_bits;
+ if (avail > *nbits)
+ avail = *nbits;
+
+ mask = (1 << avail) - 1;
+ datum = **source;
+ if (bits_big_endian)
+ datum >>= 8 - (*source_offset_bits + *nbits);
+ else
+ datum >>= *source_offset_bits;
+ datum &= mask;
+
+ *nbits -= avail;
+ *source_offset_bits += avail;
+ if (*source_offset_bits >= 8)
+ {
+ *source_offset_bits -= 8;
+ ++*source;
+ }
+
+ return datum;
+}
+
+/* Extract some bits from a source buffer and move forward in the
+ buffer.
+
+ SOURCE is the source buffer. It is updated as bytes are read.
+ SOURCE_OFFSET_BITS is the offset into SOURCE. It is updated as
+ bits are read.
+ NBITS is the number of bits to read.
+ BITS_BIG_ENDIAN is taken directly from gdbarch.
+
+ This function returns the bits that were read. */
+
+static unsigned int
+extract_bits (const gdb_byte **source, unsigned int *source_offset_bits,
+ int nbits, int bits_big_endian)
+{
+ unsigned int datum;
+
+ gdb_assert (nbits > 0 && nbits <= 8);
+
+ datum = extract_bits_primitive (source, source_offset_bits, &nbits,
+ bits_big_endian);
+ if (nbits > 0)
+ {
+ unsigned int more;
+
+ more = extract_bits_primitive (source, source_offset_bits, &nbits,
+ bits_big_endian);
+ if (bits_big_endian)
+ datum <<= nbits;
+ else
+ more <<= nbits;
+ datum |= more;
+ }
+
+ return datum;
+}
+
+/* Write some bits into a buffer and move forward in the buffer.
+
+ DATUM is the bits to write. The low-order bits of DATUM are used.
+ DEST is the destination buffer. It is updated as bytes are
+ written.
+ DEST_OFFSET_BITS is the bit offset in DEST at which writing is
+ done.
+ NBITS is the number of valid bits in DATUM.
+ BITS_BIG_ENDIAN is taken directly from gdbarch. */
+
+static void
+insert_bits (unsigned int datum,
+ gdb_byte *dest, unsigned int dest_offset_bits,
+ int nbits, int bits_big_endian)
+{
+ unsigned int mask;
+
+ gdb_assert (dest_offset_bits >= 0 && dest_offset_bits + nbits <= 8);
+
+ mask = (1 << nbits) - 1;
+ if (bits_big_endian)
+ {
+ datum <<= 8 - (dest_offset_bits + nbits);
+ mask <<= 8 - (dest_offset_bits + nbits);
+ }
+ else
+ {
+ datum <<= dest_offset_bits;
+ mask <<= dest_offset_bits;
+ }
+
+ gdb_assert ((datum & ~mask) == 0);
+
+ *dest = (*dest & ~mask) | datum;
+}
+
+/* Copy bits from a source to a destination.
+
+ DEST is where the bits should be written.
+ DEST_OFFSET_BITS is the bit offset into DEST.
+ SOURCE is the source of bits.
+ SOURCE_OFFSET_BITS is the bit offset into SOURCE.
+ BIT_COUNT is the number of bits to copy.
+ BITS_BIG_ENDIAN is taken directly from gdbarch. */
+
+static void
+copy_bitwise (gdb_byte *dest, unsigned int dest_offset_bits,
+ const gdb_byte *source, unsigned int source_offset_bits,
+ unsigned int bit_count,
+ int bits_big_endian)
+{
+ unsigned int dest_avail;
+ int datum;
+
+ /* Reduce everything to byte-size pieces. */
+ dest += dest_offset_bits / 8;
+ dest_offset_bits %= 8;
+ source += source_offset_bits / 8;
+ source_offset_bits %= 8;
+
+ dest_avail = 8 - dest_offset_bits % 8;
+
+ /* See if we can fill the first destination byte. */
+ if (dest_avail < bit_count)
+ {
+ datum = extract_bits (&source, &source_offset_bits, dest_avail,
+ bits_big_endian);
+ insert_bits (datum, dest, dest_offset_bits, dest_avail, bits_big_endian);
+ ++dest;
+ dest_offset_bits = 0;
+ bit_count -= dest_avail;
+ }
+
+ /* Now, either DEST_OFFSET_BITS is byte-aligned, or we have fewer
+ than 8 bits remaining. */
+ gdb_assert (dest_offset_bits % 8 == 0 || bit_count < 8);
+ for (; bit_count >= 8; bit_count -= 8)
+ {
+ datum = extract_bits (&source, &source_offset_bits, 8, bits_big_endian);
+ *dest++ = (gdb_byte) datum;
+ }
+
+ /* Finally, we may have a few leftover bits. */
+ gdb_assert (bit_count <= 8 - dest_offset_bits % 8);
+ if (bit_count > 0)
+ {
+ datum = extract_bits (&source, &source_offset_bits, bit_count,
+ bits_big_endian);
+ insert_bits (datum, dest, dest_offset_bits, bit_count, bits_big_endian);
+ }
+}
+
+static void
+read_pieced_value (struct value *v)
+{
+ int i;
+ long offset = 0;
+ ULONGEST bits_to_skip;
+ gdb_byte *contents;
+ struct piece_closure *c = (struct piece_closure *) value_computed_closure (v);
+ struct frame_info *frame = frame_find_by_id (VALUE_FRAME_ID (v));
+ size_t type_len;
+ size_t buffer_size = 0;
+ char *buffer = NULL;
+ struct cleanup *cleanup;
+ int bits_big_endian
+ = gdbarch_bits_big_endian (get_type_arch (value_type (v)));
+
+ if (value_type (v) != value_enclosing_type (v))
+ internal_error (__FILE__, __LINE__,
+ _("Should not be able to create a lazy value with "
+ "an enclosing type"));
+
+ cleanup = make_cleanup (free_current_contents, &buffer);
+
+ contents = value_contents_raw (v);
+ bits_to_skip = 8 * value_offset (v);
+ type_len = 8 * TYPE_LENGTH (value_type (v));
+
+ for (i = 0; i < c->n_pieces && offset < type_len; i++)
+ {
+ struct dwarf_expr_piece *p = &c->pieces[i];
+ size_t this_size, this_size_bits;
+ long dest_offset_bits, source_offset_bits, source_offset;
+ const gdb_byte *intermediate_buffer;
+
+ /* Compute size, source, and destination offsets for copying, in
+ bits. */
+ this_size_bits = p->size;
+ if (bits_to_skip > 0 && bits_to_skip >= this_size_bits)
+ {
+ bits_to_skip -= this_size_bits;
+ continue;
+ }
+ if (this_size_bits > type_len - offset)
+ this_size_bits = type_len - offset;
+ if (bits_to_skip > 0)
+ {
+ dest_offset_bits = 0;
+ source_offset_bits = bits_to_skip;
+ this_size_bits -= bits_to_skip;
+ bits_to_skip = 0;
+ }
+ else
+ {
+ dest_offset_bits = offset;
+ source_offset_bits = 0;
+ }
+
+ this_size = (this_size_bits + source_offset_bits % 8 + 7) / 8;
+ source_offset = source_offset_bits / 8;
+ if (buffer_size < this_size)
+ {
+ buffer_size = this_size;
+ buffer = xrealloc (buffer, buffer_size);
+ }
+ intermediate_buffer = buffer;
+
+ /* Copy from the source to DEST_BUFFER. */
+ switch (p->location)
+ {
+ case DWARF_VALUE_REGISTER:
+ {
+ struct gdbarch *arch = get_frame_arch (frame);
+ int gdb_regnum = gdbarch_dwarf2_reg_to_regnum (arch,
+ p->v.expr.value);
+ int reg_offset = source_offset;
+
+ if (gdbarch_byte_order (arch) == BFD_ENDIAN_BIG
+ && this_size < register_size (arch, gdb_regnum))
+ {
+ /* Big-endian, and we want less than full size. */
+ reg_offset = register_size (arch, gdb_regnum) - this_size;
+ /* We want the lower-order THIS_SIZE_BITS of the bytes
+ we extract from the register. */
+ source_offset_bits += 8 * this_size - this_size_bits;
+ }
+
+ if (gdb_regnum != -1)
+ {
+ get_frame_register_bytes (frame, gdb_regnum, reg_offset,
+ this_size, buffer);
+ }
+ else
+ {
+ error (_("Unable to access DWARF register number %s"),
+ paddress (arch, p->v.expr.value));
+ }
+ }
+ break;
+
+ case DWARF_VALUE_MEMORY:
+ if (p->v.expr.in_stack_memory)
+ read_stack (p->v.expr.value + source_offset, buffer, this_size);
+ else
+ read_memory (p->v.expr.value + source_offset, buffer, this_size);
+ break;
+
+ case DWARF_VALUE_STACK:
+ {
+ struct gdbarch *gdbarch = get_type_arch (value_type (v));
+ size_t n = this_size;
+
+ if (n > c->addr_size - source_offset)
+ n = (c->addr_size >= source_offset
+ ? c->addr_size - source_offset
+ : 0);
+ if (n == 0)
+ {
+ /* Nothing. */
+ }
+ else if (source_offset == 0)
+ store_unsigned_integer (buffer, n,
+ gdbarch_byte_order (gdbarch),
+ p->v.expr.value);
+ else
+ {
+ gdb_byte bytes[sizeof (ULONGEST)];
+
+ store_unsigned_integer (bytes, n + source_offset,
+ gdbarch_byte_order (gdbarch),
+ p->v.expr.value);
+ memcpy (buffer, bytes + source_offset, n);
+ }
+ }
+ break;
+
+ case DWARF_VALUE_LITERAL:
+ {
+ size_t n = this_size;
+
+ if (n > p->v.literal.length - source_offset)
+ n = (p->v.literal.length >= source_offset
+ ? p->v.literal.length - source_offset
+ : 0);
+ if (n != 0)
+ intermediate_buffer = p->v.literal.data + source_offset;
+ }
+ break;
+
+ case DWARF_VALUE_OPTIMIZED_OUT:
+ /* We just leave the bits empty for now. This is not ideal
+ but gdb currently does not have a nice way to represent
+ optimized-out pieces. */
+ warning (_("bits %ld-%ld in computed object were optimized out; "
+ "replacing with zeroes"),
+ offset,
+ offset + (long) this_size_bits);
+ break;
+
+ default:
+ internal_error (__FILE__, __LINE__, _("invalid location type"));
+ }
+
+ if (p->location != DWARF_VALUE_OPTIMIZED_OUT)
+ copy_bitwise (contents, dest_offset_bits,
+ intermediate_buffer, source_offset_bits % 8,
+ this_size_bits, bits_big_endian);
+
+ offset += this_size_bits;
+ }
+
+ do_cleanups (cleanup);
+}
+
+static void
+write_pieced_value (struct value *to, struct value *from)
+{
+ int i;
+ long offset = 0;
+ ULONGEST bits_to_skip;
+ const gdb_byte *contents;
+ struct piece_closure *c = (struct piece_closure *) value_computed_closure (to);
+ struct frame_info *frame = frame_find_by_id (VALUE_FRAME_ID (to));
+ size_t type_len;
+ size_t buffer_size = 0;
+ char *buffer = NULL;
+ struct cleanup *cleanup;
+ int bits_big_endian
+ = gdbarch_bits_big_endian (get_type_arch (value_type (to)));
+
+ if (frame == NULL)
+ {
+ set_value_optimized_out (to, 1);
+ return;
+ }
+
+ cleanup = make_cleanup (free_current_contents, &buffer);
+
+ contents = value_contents (from);
+ bits_to_skip = 8 * value_offset (to);
+ type_len = 8 * TYPE_LENGTH (value_type (to));
+ for (i = 0; i < c->n_pieces && offset < type_len; i++)
+ {
+ struct dwarf_expr_piece *p = &c->pieces[i];
+ size_t this_size_bits, this_size;
+ long dest_offset_bits, source_offset_bits, dest_offset, source_offset;
+ int need_bitwise;
+ const gdb_byte *source_buffer;
+
+ this_size_bits = p->size;
+ if (bits_to_skip > 0 && bits_to_skip >= this_size_bits)
+ {
+ bits_to_skip -= this_size_bits;
+ continue;
+ }
+ if (this_size_bits > type_len - offset)
+ this_size_bits = type_len - offset;
+ if (bits_to_skip > 0)
+ {
+ dest_offset_bits = bits_to_skip;
+ source_offset_bits = 0;
+ this_size_bits -= bits_to_skip;
+ bits_to_skip = 0;
+ }
+ else
+ {
+ dest_offset_bits = 0;
+ source_offset_bits = offset;
+ }
+
+ this_size = (this_size_bits + source_offset_bits % 8 + 7) / 8;
+ source_offset = source_offset_bits / 8;
+ dest_offset = dest_offset_bits / 8;
+ if (dest_offset_bits % 8 == 0 && source_offset_bits % 8 == 0)
+ {
+ source_buffer = contents + source_offset;
+ need_bitwise = 0;
+ }
+ else
+ {
+ if (buffer_size < this_size)
+ {
+ buffer_size = this_size;
+ buffer = xrealloc (buffer, buffer_size);
+ }
+ source_buffer = buffer;
+ need_bitwise = 1;
+ }
+
+ switch (p->location)
+ {
+ case DWARF_VALUE_REGISTER:
+ {
+ struct gdbarch *arch = get_frame_arch (frame);
+ int gdb_regnum = gdbarch_dwarf2_reg_to_regnum (arch, p->v.expr.value);
+ int reg_offset = dest_offset;
+
+ if (gdbarch_byte_order (arch) == BFD_ENDIAN_BIG
+ && this_size <= register_size (arch, gdb_regnum))
+ /* Big-endian, and we want less than full size. */
+ reg_offset = register_size (arch, gdb_regnum) - this_size;
+
+ if (gdb_regnum != -1)
+ {
+ if (need_bitwise)
+ {
+ get_frame_register_bytes (frame, gdb_regnum, reg_offset,
+ this_size, buffer);
+ copy_bitwise (buffer, dest_offset_bits,
+ contents, source_offset_bits,
+ this_size_bits,
+ bits_big_endian);
+ }
+
+ put_frame_register_bytes (frame, gdb_regnum, reg_offset,
+ this_size, source_buffer);
+ }
+ else
+ {
+ error (_("Unable to write to DWARF register number %s"),
+ paddress (arch, p->v.expr.value));
+ }
+ }
+ break;
+ case DWARF_VALUE_MEMORY:
+ if (need_bitwise)
+ {
+ /* Only the first and last bytes can possibly have any
+ bits reused. */
+ read_memory (p->v.expr.value + dest_offset, buffer, 1);
+ read_memory (p->v.expr.value + dest_offset + this_size - 1,
+ buffer + this_size - 1, 1);
+ copy_bitwise (buffer, dest_offset_bits,
+ contents, source_offset_bits,
+ this_size_bits,
+ bits_big_endian);
+ }
+
+ write_memory (p->v.expr.value + dest_offset,
+ source_buffer, this_size);
+ break;
+ default:
+ set_value_optimized_out (to, 1);
+ goto done;
+ }
+ offset += this_size_bits;
+ }
+
+ done:
+ do_cleanups (cleanup);
+}
+
+static void *
+copy_pieced_value_closure (struct value *v)
+{
+ struct piece_closure *c = (struct piece_closure *) value_computed_closure (v);
+
+ ++c->refc;
+ return c;
+}
+
+static void
+free_pieced_value_closure (struct value *v)
+{
+ struct piece_closure *c = (struct piece_closure *) value_computed_closure (v);
+
+ --c->refc;
+ if (c->refc == 0)
+ {
+ xfree (c->pieces);
+ xfree (c);
+ }
+}
+
+/* Functions for accessing a variable described by DW_OP_piece. */
+static struct lval_funcs pieced_value_funcs = {
+ read_pieced_value,
+ write_pieced_value,
+ copy_pieced_value_closure,
+ free_pieced_value_closure
+};
+
/* Evaluate a location description, starting at DATA and with length
- SIZE, to find the current location of variable VAR in the context
+ SIZE, to find the current location of variable of TYPE in the context
of FRAME. */
+
static struct value *
-dwarf2_evaluate_loc_desc (struct symbol *var, struct frame_info *frame,
- gdb_byte *data, unsigned short size,
- struct objfile *objfile)
+dwarf2_evaluate_loc_desc (struct type *type, struct frame_info *frame,
+ const gdb_byte *data, unsigned short size,
+ struct dwarf2_per_cu_data *per_cu)
{
- struct gdbarch *arch = get_frame_arch (frame);
struct value *retval;
struct dwarf_expr_baton baton;
struct dwarf_expr_context *ctx;
+ struct cleanup *old_chain;
if (size == 0)
{
- retval = allocate_value (SYMBOL_TYPE (var));
+ retval = allocate_value (type);
VALUE_LVAL (retval) = not_lval;
set_value_optimized_out (retval, 1);
return retval;
}
baton.frame = frame;
- baton.objfile = objfile;
+ baton.objfile = dwarf2_per_cu_objfile (per_cu);
ctx = new_dwarf_expr_context ();
+ old_chain = make_cleanup_free_dwarf_expr_context (ctx);
+
+ ctx->gdbarch = get_objfile_arch (baton.objfile);
+ ctx->addr_size = dwarf2_per_cu_addr_size (per_cu);
ctx->baton = &baton;
ctx->read_reg = dwarf_expr_read_reg;
ctx->read_mem = dwarf_expr_read_mem;
ctx->get_frame_base = dwarf_expr_frame_base;
+ ctx->get_frame_cfa = dwarf_expr_frame_cfa;
ctx->get_tls_address = dwarf_expr_tls_address;
dwarf_expr_eval (ctx, data, size);
if (ctx->num_pieces > 0)
{
- int i;
- long offset = 0;
- bfd_byte *contents;
+ struct piece_closure *c;
+ struct frame_id frame_id = get_frame_id (frame);
- retval = allocate_value (SYMBOL_TYPE (var));
- contents = value_contents_raw (retval);
- for (i = 0; i < ctx->num_pieces; i++)
- {
- struct dwarf_expr_piece *p = &ctx->pieces[i];
- if (p->in_reg)
- {
- bfd_byte regval[MAX_REGISTER_SIZE];
- int gdb_regnum = DWARF2_REG_TO_REGNUM (p->value);
- get_frame_register (frame, gdb_regnum, regval);
- memcpy (contents + offset, regval, p->size);
- }
- else /* In memory? */
- {
- read_memory (p->value, contents + offset, p->size);
- }
- offset += p->size;
- }
- }
- else if (ctx->in_reg)
- {
- CORE_ADDR dwarf_regnum = dwarf_expr_fetch (ctx, 0);
- int gdb_regnum = DWARF2_REG_TO_REGNUM (dwarf_regnum);
- retval = value_from_register (SYMBOL_TYPE (var), gdb_regnum, frame);
+ c = allocate_piece_closure (ctx->num_pieces, ctx->pieces,
+ ctx->addr_size);
+ retval = allocate_computed_value (type, &pieced_value_funcs, c);
+ VALUE_FRAME_ID (retval) = frame_id;
}
else
{
- CORE_ADDR address = dwarf_expr_fetch (ctx, 0);
-
- retval = allocate_value (SYMBOL_TYPE (var));
- VALUE_LVAL (retval) = lval_memory;
- set_value_lazy (retval, 1);
- VALUE_ADDRESS (retval) = address;
+ switch (ctx->location)
+ {
+ case DWARF_VALUE_REGISTER:
+ {
+ struct gdbarch *arch = get_frame_arch (frame);
+ CORE_ADDR dwarf_regnum = dwarf_expr_fetch (ctx, 0);
+ int gdb_regnum = gdbarch_dwarf2_reg_to_regnum (arch, dwarf_regnum);
+
+ if (gdb_regnum != -1)
+ retval = value_from_register (type, gdb_regnum, frame);
+ else
+ error (_("Unable to access DWARF register number %s"),
+ paddress (arch, dwarf_regnum));
+ }
+ break;
+
+ case DWARF_VALUE_MEMORY:
+ {
+ CORE_ADDR address = dwarf_expr_fetch (ctx, 0);
+ int in_stack_memory = dwarf_expr_fetch_in_stack_memory (ctx, 0);
+
+ retval = allocate_value (type);
+ VALUE_LVAL (retval) = lval_memory;
+ set_value_lazy (retval, 1);
+ if (in_stack_memory)
+ set_value_stack (retval, 1);
+ set_value_address (retval, address);
+ }
+ break;
+
+ case DWARF_VALUE_STACK:
+ {
+ ULONGEST value = (ULONGEST) dwarf_expr_fetch (ctx, 0);
+ bfd_byte *contents;
+ size_t n = ctx->addr_size;
+
+ retval = allocate_value (type);
+ contents = value_contents_raw (retval);
+ if (n > TYPE_LENGTH (type))
+ n = TYPE_LENGTH (type);
+ store_unsigned_integer (contents, n,
+ gdbarch_byte_order (ctx->gdbarch),
+ value);
+ }
+ break;
+
+ case DWARF_VALUE_LITERAL:
+ {
+ bfd_byte *contents;
+ size_t n = ctx->len;
+
+ retval = allocate_value (type);
+ contents = value_contents_raw (retval);
+ if (n > TYPE_LENGTH (type))
+ n = TYPE_LENGTH (type);
+ memcpy (contents, ctx->data, n);
+ }
+ break;
+
+ /* DWARF_VALUE_OPTIMIZED_OUT can't occur in this context --
+ it can only be encountered when making a piece. */
+ case DWARF_VALUE_OPTIMIZED_OUT:
+ default:
+ internal_error (__FILE__, __LINE__, _("invalid location type"));
+ }
}
set_value_initialized (retval, ctx->initialized);
- free_dwarf_expr_context (ctx);
+ do_cleanups (old_chain);
return retval;
}
-
-
-
-
\f
/* Helper functions and baton for dwarf2_loc_desc_needs_frame. */
needs_frame_read_reg (void *baton, int regnum)
{
struct needs_frame_baton *nf_baton = baton;
+
nf_baton->needs_frame = 1;
return 1;
}
/* Frame-relative accesses do require a frame. */
static void
-needs_frame_frame_base (void *baton, gdb_byte **start, size_t * length)
+needs_frame_frame_base (void *baton, const gdb_byte **start, size_t * length)
{
static gdb_byte lit0 = DW_OP_lit0;
struct needs_frame_baton *nf_baton = baton;
nf_baton->needs_frame = 1;
}
+/* CFA accesses require a frame. */
+
+static CORE_ADDR
+needs_frame_frame_cfa (void *baton)
+{
+ struct needs_frame_baton *nf_baton = baton;
+
+ nf_baton->needs_frame = 1;
+ return 1;
+}
+
/* Thread-local accesses do require a frame. */
static CORE_ADDR
needs_frame_tls_address (void *baton, CORE_ADDR offset)
{
struct needs_frame_baton *nf_baton = baton;
+
nf_baton->needs_frame = 1;
return 1;
}
requires a frame to evaluate. */
static int
-dwarf2_loc_desc_needs_frame (gdb_byte *data, unsigned short size)
+dwarf2_loc_desc_needs_frame (const gdb_byte *data, unsigned short size,
+ struct dwarf2_per_cu_data *per_cu)
{
struct needs_frame_baton baton;
struct dwarf_expr_context *ctx;
int in_reg;
+ struct cleanup *old_chain;
baton.needs_frame = 0;
ctx = new_dwarf_expr_context ();
+ old_chain = make_cleanup_free_dwarf_expr_context (ctx);
+
+ ctx->gdbarch = get_objfile_arch (dwarf2_per_cu_objfile (per_cu));
+ ctx->addr_size = dwarf2_per_cu_addr_size (per_cu);
ctx->baton = &baton;
ctx->read_reg = needs_frame_read_reg;
ctx->read_mem = needs_frame_read_mem;
ctx->get_frame_base = needs_frame_frame_base;
+ ctx->get_frame_cfa = needs_frame_frame_cfa;
ctx->get_tls_address = needs_frame_tls_address;
dwarf_expr_eval (ctx, data, size);
- in_reg = ctx->in_reg;
+ in_reg = ctx->location == DWARF_VALUE_REGISTER;
if (ctx->num_pieces > 0)
{
/* If the location has several pieces, and any of them are in
registers, then we will need a frame to fetch them from. */
for (i = 0; i < ctx->num_pieces; i++)
- if (ctx->pieces[i].in_reg)
+ if (ctx->pieces[i].location == DWARF_VALUE_REGISTER)
in_reg = 1;
}
- free_dwarf_expr_context (ctx);
+ do_cleanups (old_chain);
return baton.needs_frame || in_reg;
}
-static void
-dwarf2_tracepoint_var_ref (struct symbol *symbol, struct agent_expr *ax,
- struct axs_value *value, gdb_byte *data,
- int size)
+/* This struct keeps track of the pieces that make up a multi-location
+ object, for use in agent expression generation. It is
+ superficially similar to struct dwarf_expr_piece, but
+ dwarf_expr_piece is designed for use in immediate evaluation, and
+ does not, for example, have a way to record both base register and
+ offset. */
+
+struct axs_var_loc
{
- if (size == 0)
- error (_("Symbol \"%s\" has been optimized out."),
- SYMBOL_PRINT_NAME (symbol));
+ /* Memory vs register, etc */
+ enum axs_lvalue_kind kind;
+
+ /* If non-zero, number of bytes in this fragment */
+ unsigned bytes;
+
+ /* (GDB-numbered) reg, or base reg if >= 0 */
+ int reg;
- if (size == 1
- && data[0] >= DW_OP_reg0
- && data[0] <= DW_OP_reg31)
+ /* offset from reg */
+ LONGEST offset;
+};
+
+static const gdb_byte *
+dwarf2_tracepoint_var_loc (struct symbol *symbol,
+ struct agent_expr *ax,
+ struct axs_var_loc *loc,
+ struct gdbarch *gdbarch,
+ const gdb_byte *data, const gdb_byte *end)
+{
+ if (data[0] >= DW_OP_reg0 && data[0] <= DW_OP_reg31)
{
- value->kind = axs_lvalue_register;
- value->u.reg = data[0] - DW_OP_reg0;
+ loc->kind = axs_lvalue_register;
+ loc->reg = gdbarch_dwarf2_reg_to_regnum (gdbarch, data[0] - DW_OP_reg0);
+ data += 1;
}
else if (data[0] == DW_OP_regx)
{
ULONGEST reg;
- read_uleb128 (data + 1, data + size, ®);
- value->kind = axs_lvalue_register;
- value->u.reg = reg;
+
+ data = read_uleb128 (data + 1, end, ®);
+ loc->kind = axs_lvalue_register;
+ loc->reg = gdbarch_dwarf2_reg_to_regnum (gdbarch, reg);
}
else if (data[0] == DW_OP_fbreg)
{
- /* And this is worse than just minimal; we should honor the frame base
- as above. */
- int frame_reg;
+ struct block *b;
+ struct symbol *framefunc;
+ int frame_reg = 0;
LONGEST frame_offset;
- gdb_byte *buf_end;
+ const gdb_byte *base_data;
+ size_t base_size;
+ LONGEST base_offset = 0;
- buf_end = read_sleb128 (data + 1, data + size, &frame_offset);
- if (buf_end != data + size)
- error (_("Unexpected opcode after DW_OP_fbreg for symbol \"%s\"."),
- SYMBOL_PRINT_NAME (symbol));
+ b = block_for_pc (ax->scope);
+
+ if (!b)
+ error (_("No block found for address"));
+
+ framefunc = block_linkage_function (b);
+
+ if (!framefunc)
+ error (_("No function found for block"));
+
+ dwarf_expr_frame_base_1 (framefunc, ax->scope,
+ &base_data, &base_size);
+
+ if (base_data[0] >= DW_OP_breg0 && base_data[0] <= DW_OP_breg31)
+ {
+ const gdb_byte *buf_end;
+
+ frame_reg = base_data[0] - DW_OP_breg0;
+ buf_end = read_sleb128 (base_data + 1,
+ base_data + base_size, &base_offset);
+ if (buf_end != base_data + base_size)
+ error (_("Unexpected opcode after DW_OP_breg%u for symbol \"%s\"."),
+ frame_reg, SYMBOL_PRINT_NAME (symbol));
+ }
+ else if (base_data[0] >= DW_OP_reg0 && base_data[0] <= DW_OP_reg31)
+ {
+ /* The frame base is just the register, with no offset. */
+ frame_reg = base_data[0] - DW_OP_reg0;
+ base_offset = 0;
+ }
+ else
+ {
+ /* We don't know what to do with the frame base expression,
+ so we can't trace this variable; give up. */
+ error (_("Cannot generate expression to collect symbol \"%s\"; DWARF 2 encoding not handled, first opcode in base data is 0x%x."),
+ SYMBOL_PRINT_NAME (symbol), base_data[0]);
+ }
- TARGET_VIRTUAL_FRAME_POINTER (ax->scope, &frame_reg, &frame_offset);
- ax_reg (ax, frame_reg);
- ax_const_l (ax, frame_offset);
- ax_simple (ax, aop_add);
+ data = read_sleb128 (data + 1, end, &frame_offset);
- value->kind = axs_lvalue_memory;
+ loc->kind = axs_lvalue_memory;
+ loc->reg = gdbarch_dwarf2_reg_to_regnum (gdbarch, frame_reg);
+ loc->offset = base_offset + frame_offset;
}
- else if (data[0] >= DW_OP_breg0
- && data[0] <= DW_OP_breg31)
+ else if (data[0] >= DW_OP_breg0 && data[0] <= DW_OP_breg31)
{
unsigned int reg;
LONGEST offset;
- gdb_byte *buf_end;
reg = data[0] - DW_OP_breg0;
- buf_end = read_sleb128 (data + 1, data + size, &offset);
- if (buf_end != data + size)
- error (_("Unexpected opcode after DW_OP_breg%u for symbol \"%s\"."),
- reg, SYMBOL_PRINT_NAME (symbol));
-
- ax_reg (ax, reg);
- ax_const_l (ax, offset);
- ax_simple (ax, aop_add);
+ data = read_sleb128 (data + 1, end, &offset);
- value->kind = axs_lvalue_memory;
+ loc->kind = axs_lvalue_memory;
+ loc->reg = gdbarch_dwarf2_reg_to_regnum (gdbarch, reg);
+ loc->offset = offset;
}
else
error (_("Unsupported DWARF opcode 0x%x in the location of \"%s\"."),
data[0], SYMBOL_PRINT_NAME (symbol));
+
+ return data;
}
+
+/* Given the location of a piece, issue bytecodes that will access it. */
+
+static void
+dwarf2_tracepoint_var_access (struct agent_expr *ax,
+ struct axs_value *value,
+ struct axs_var_loc *loc)
+{
+ value->kind = loc->kind;
+
+ switch (loc->kind)
+ {
+ case axs_lvalue_register:
+ value->u.reg = loc->reg;
+ break;
+
+ case axs_lvalue_memory:
+ ax_reg (ax, loc->reg);
+ if (loc->offset)
+ {
+ ax_const_l (ax, loc->offset);
+ ax_simple (ax, aop_add);
+ }
+ break;
+
+ default:
+ internal_error (__FILE__, __LINE__, _("Unhandled value kind in dwarf2_tracepoint_var_access"));
+ }
+}
+
+static void
+dwarf2_tracepoint_var_ref (struct symbol *symbol, struct gdbarch *gdbarch,
+ struct agent_expr *ax, struct axs_value *value,
+ const gdb_byte *data, int size)
+{
+ const gdb_byte *end = data + size;
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ /* In practice, a variable is not going to be spread across
+ dozens of registers or memory locations. If someone comes up
+ with a real-world example, revisit this. */
+#define MAX_FRAGS 16
+ struct axs_var_loc fragments[MAX_FRAGS];
+ int nfrags = 0, frag;
+ int length = 0;
+ int piece_ok = 0;
+ int bad = 0;
+ int first = 1;
+
+ if (!data || size == 0)
+ {
+ value->optimized_out = 1;
+ return;
+ }
+
+ while (data < end)
+ {
+ if (!piece_ok)
+ {
+ if (nfrags == MAX_FRAGS)
+ error (_("Too many pieces in location for \"%s\"."),
+ SYMBOL_PRINT_NAME (symbol));
+
+ fragments[nfrags].bytes = 0;
+ data = dwarf2_tracepoint_var_loc (symbol, ax, &fragments[nfrags],
+ gdbarch, data, end);
+ nfrags++;
+ piece_ok = 1;
+ }
+ else if (data[0] == DW_OP_piece)
+ {
+ ULONGEST bytes;
+
+ data = read_uleb128 (data + 1, end, &bytes);
+ /* Only deal with 4 byte fragments for now. */
+ if (bytes != 4)
+ error (_("DW_OP_piece %s not supported in location for \"%s\"."),
+ pulongest (bytes), SYMBOL_PRINT_NAME (symbol));
+ fragments[nfrags - 1].bytes = bytes;
+ length += bytes;
+ piece_ok = 0;
+ }
+ else
+ {
+ bad = 1;
+ break;
+ }
+ }
+
+ if (bad || data > end)
+ error (_("Corrupted DWARF expression for \"%s\"."),
+ SYMBOL_PRINT_NAME (symbol));
+
+ /* If single expression, no pieces, convert to external format. */
+ if (length == 0)
+ {
+ dwarf2_tracepoint_var_access (ax, value, &fragments[0]);
+ return;
+ }
+
+ if (length != TYPE_LENGTH (value->type))
+ error (_("Inconsistent piece information for \"%s\"."),
+ SYMBOL_PRINT_NAME (symbol));
+
+ /* Emit bytecodes to assemble the pieces into a single stack entry. */
+
+ for ((frag = (byte_order == BFD_ENDIAN_BIG ? 0 : nfrags - 1));
+ nfrags--;
+ (frag += (byte_order == BFD_ENDIAN_BIG ? 1 : -1)))
+ {
+ if (!first)
+ {
+ /* shift the previous fragment up 32 bits */
+ ax_const_l (ax, 32);
+ ax_simple (ax, aop_lsh);
+ }
+
+ dwarf2_tracepoint_var_access (ax, value, &fragments[frag]);
+
+ switch (value->kind)
+ {
+ case axs_lvalue_register:
+ ax_reg (ax, value->u.reg);
+ break;
+
+ case axs_lvalue_memory:
+ {
+ extern int trace_kludge; /* Ugh. */
+
+ gdb_assert (fragments[frag].bytes == 4);
+ if (trace_kludge)
+ ax_trace_quick (ax, 4);
+ ax_simple (ax, aop_ref32);
+ }
+ break;
+ }
+
+ if (!first)
+ {
+ /* or the new fragment into the previous */
+ ax_zero_ext (ax, 32);
+ ax_simple (ax, aop_bit_or);
+ }
+ first = 0;
+ }
+ value->kind = axs_rvalue;
+}
+
\f
/* Return the value of SYMBOL in FRAME using the DWARF-2 expression
evaluator to calculate the location. */
{
struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
struct value *val;
- val = dwarf2_evaluate_loc_desc (symbol, frame, dlbaton->data, dlbaton->size,
- dlbaton->objfile);
+
+ val = dwarf2_evaluate_loc_desc (SYMBOL_TYPE (symbol), frame, dlbaton->data,
+ dlbaton->size, dlbaton->per_cu);
return val;
}
locexpr_read_needs_frame (struct symbol *symbol)
{
struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
- return dwarf2_loc_desc_needs_frame (dlbaton->data, dlbaton->size);
+
+ return dwarf2_loc_desc_needs_frame (dlbaton->data, dlbaton->size,
+ dlbaton->per_cu);
}
-/* Print a natural-language description of SYMBOL to STREAM. */
-static int
-locexpr_describe_location (struct symbol *symbol, struct ui_file *stream)
+/* Describe a single piece of a location, returning an updated
+ position in the bytecode sequence. */
+
+static const gdb_byte *
+locexpr_describe_location_piece (struct symbol *symbol, struct ui_file *stream,
+ CORE_ADDR addr, struct objfile *objfile,
+ const gdb_byte *data, int size,
+ unsigned int addr_size)
{
- /* FIXME: be more extensive. */
- struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
+ struct gdbarch *gdbarch = get_objfile_arch (objfile);
+ int regno;
+
+ if (data[0] >= DW_OP_reg0 && data[0] <= DW_OP_reg31)
+ {
+ regno = gdbarch_dwarf2_reg_to_regnum (gdbarch, data[0] - DW_OP_reg0);
+ fprintf_filtered (stream, _("a variable in $%s"),
+ gdbarch_register_name (gdbarch, regno));
+ data += 1;
+ }
+ else if (data[0] == DW_OP_regx)
+ {
+ ULONGEST reg;
+
+ data = read_uleb128 (data + 1, data + size, ®);
+ regno = gdbarch_dwarf2_reg_to_regnum (gdbarch, reg);
+ fprintf_filtered (stream, _("a variable in $%s"),
+ gdbarch_register_name (gdbarch, regno));
+ }
+ else if (data[0] == DW_OP_fbreg)
+ {
+ struct block *b;
+ struct symbol *framefunc;
+ int frame_reg = 0;
+ LONGEST frame_offset;
+ const gdb_byte *base_data;
+ size_t base_size;
+ LONGEST base_offset = 0;
+
+ b = block_for_pc (addr);
+
+ if (!b)
+ error (_("No block found for address for symbol \"%s\"."),
+ SYMBOL_PRINT_NAME (symbol));
+
+ framefunc = block_linkage_function (b);
+
+ if (!framefunc)
+ error (_("No function found for block for symbol \"%s\"."),
+ SYMBOL_PRINT_NAME (symbol));
+
+ dwarf_expr_frame_base_1 (framefunc, addr, &base_data, &base_size);
+
+ if (base_data[0] >= DW_OP_breg0 && base_data[0] <= DW_OP_breg31)
+ {
+ const gdb_byte *buf_end;
+
+ frame_reg = base_data[0] - DW_OP_breg0;
+ buf_end = read_sleb128 (base_data + 1,
+ base_data + base_size, &base_offset);
+ if (buf_end != base_data + base_size)
+ error (_("Unexpected opcode after DW_OP_breg%u for symbol \"%s\"."),
+ frame_reg, SYMBOL_PRINT_NAME (symbol));
+ }
+ else if (base_data[0] >= DW_OP_reg0 && base_data[0] <= DW_OP_reg31)
+ {
+ /* The frame base is just the register, with no offset. */
+ frame_reg = base_data[0] - DW_OP_reg0;
+ base_offset = 0;
+ }
+ else
+ {
+ /* We don't know what to do with the frame base expression,
+ so we can't trace this variable; give up. */
+ error (_("Cannot describe location of symbol \"%s\"; "
+ "DWARF 2 encoding not handled, "
+ "first opcode in base data is 0x%x."),
+ SYMBOL_PRINT_NAME (symbol), base_data[0]);
+ }
- if (dlbaton->size == 1
- && dlbaton->data[0] >= DW_OP_reg0
- && dlbaton->data[0] <= DW_OP_reg31)
+ regno = gdbarch_dwarf2_reg_to_regnum (gdbarch, frame_reg);
+
+ data = read_sleb128 (data + 1, data + size, &frame_offset);
+
+ fprintf_filtered (stream, _("a variable at frame base reg $%s offset %s+%s"),
+ gdbarch_register_name (gdbarch, regno),
+ plongest (base_offset), plongest (frame_offset));
+ }
+ else if (data[0] >= DW_OP_breg0 && data[0] <= DW_OP_breg31)
{
- int regno = DWARF2_REG_TO_REGNUM (dlbaton->data[0] - DW_OP_reg0);
+ LONGEST offset;
+
+ regno = gdbarch_dwarf2_reg_to_regnum (gdbarch, data[0] - DW_OP_breg0);
+
+ data = read_sleb128 (data + 1, data + size, &offset);
+
fprintf_filtered (stream,
- "a variable in register %s", REGISTER_NAME (regno));
- return 1;
+ _("a variable at offset %s from base reg $%s"),
+ plongest (offset),
+ gdbarch_register_name (gdbarch, regno));
}
/* The location expression for a TLS variable looks like this (on a
The operand represents the offset at which the variable is within
the thread local storage. */
- if (dlbaton->size > 1
- && dlbaton->data[dlbaton->size - 1] == DW_OP_GNU_push_tls_address)
- if (dlbaton->data[0] == DW_OP_addr)
- {
- int bytes_read;
- CORE_ADDR offset = dwarf2_read_address (&dlbaton->data[1],
- &dlbaton->data[dlbaton->size - 1],
- &bytes_read);
- fprintf_filtered (stream,
- "a thread-local variable at offset %s in the "
- "thread-local storage for `%s'",
- paddr_nz (offset), dlbaton->objfile->name);
- return 1;
- }
-
+ else if (size > 1
+ && data[size - 1] == DW_OP_GNU_push_tls_address
+ && data[0] == DW_OP_addr)
+ {
+ CORE_ADDR offset = dwarf2_read_address (gdbarch,
+ data + 1,
+ data + size - 1,
+ addr_size);
- fprintf_filtered (stream,
- "a variable with complex or multiple locations (DWARF2)");
- return 1;
+ fprintf_filtered (stream,
+ _("a thread-local variable at offset %s "
+ "in the thread-local storage for `%s'"),
+ paddress (gdbarch, offset), objfile->name);
+
+ data += 1 + addr_size + 1;
+ }
+ else
+ fprintf_filtered (stream,
+ _("a variable with complex or multiple locations (DWARF2)"));
+
+ return data;
}
+/* Describe a single location, which may in turn consist of multiple
+ pieces. */
-/* Describe the location of SYMBOL as an agent value in VALUE, generating
- any necessary bytecode in AX.
+static void
+locexpr_describe_location_1 (struct symbol *symbol, CORE_ADDR addr,
+ struct ui_file *stream,
+ const gdb_byte *data, int size,
+ struct objfile *objfile, unsigned int addr_size)
+{
+ const gdb_byte *end = data + size;
+ int piece_done = 0, first_piece = 1, bad = 0;
- NOTE drow/2003-02-26: This function is extremely minimal, because
- doing it correctly is extremely complicated and there is no
- publicly available stub with tracepoint support for me to test
- against. When there is one this function should be revisited. */
+ /* A multi-piece description consists of multiple sequences of bytes
+ each followed by DW_OP_piece + length of piece. */
+ while (data < end)
+ {
+ if (!piece_done)
+ {
+ if (first_piece)
+ first_piece = 0;
+ else
+ fprintf_filtered (stream, _(", and "));
+
+ data = locexpr_describe_location_piece (symbol, stream, addr, objfile,
+ data, size, addr_size);
+ piece_done = 1;
+ }
+ else if (data[0] == DW_OP_piece)
+ {
+ ULONGEST bytes;
+
+ data = read_uleb128 (data + 1, end, &bytes);
+
+ fprintf_filtered (stream, _(" [%s-byte piece]"), pulongest (bytes));
+
+ piece_done = 0;
+ }
+ else
+ {
+ bad = 1;
+ break;
+ }
+ }
+
+ if (bad || data > end)
+ error (_("Corrupted DWARF2 expression for \"%s\"."),
+ SYMBOL_PRINT_NAME (symbol));
+}
+
+/* Print a natural-language description of SYMBOL to STREAM. This
+ version is for a symbol with a single location. */
static void
-locexpr_tracepoint_var_ref (struct symbol * symbol, struct agent_expr * ax,
- struct axs_value * value)
+locexpr_describe_location (struct symbol *symbol, CORE_ADDR addr,
+ struct ui_file *stream)
{
struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
+ struct objfile *objfile = dwarf2_per_cu_objfile (dlbaton->per_cu);
+ unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu);
- dwarf2_tracepoint_var_ref (symbol, ax, value, dlbaton->data, dlbaton->size);
+ locexpr_describe_location_1 (symbol, addr, stream, dlbaton->data, dlbaton->size,
+ objfile, addr_size);
+}
+
+/* Describe the location of SYMBOL as an agent value in VALUE, generating
+ any necessary bytecode in AX. */
+
+static void
+locexpr_tracepoint_var_ref (struct symbol *symbol, struct gdbarch *gdbarch,
+ struct agent_expr *ax, struct axs_value *value)
+{
+ struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
+
+ dwarf2_tracepoint_var_ref (symbol, gdbarch, ax, value,
+ dlbaton->data, dlbaton->size);
}
/* The set of location functions used with the DWARF-2 expression
evaluator. */
-const struct symbol_ops dwarf2_locexpr_funcs = {
+const struct symbol_computed_ops dwarf2_locexpr_funcs = {
locexpr_read_variable,
locexpr_read_needs_frame,
locexpr_describe_location,
{
struct dwarf2_loclist_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
struct value *val;
- gdb_byte *data;
+ const gdb_byte *data;
size_t size;
data = find_location_expression (dlbaton, &size,
set_value_optimized_out (val, 1);
}
else
- val = dwarf2_evaluate_loc_desc (symbol, frame, data, size,
- dlbaton->objfile);
+ val = dwarf2_evaluate_loc_desc (SYMBOL_TYPE (symbol), frame, data, size,
+ dlbaton->per_cu);
return val;
}
return 1;
}
-/* Print a natural-language description of SYMBOL to STREAM. */
-static int
-loclist_describe_location (struct symbol *symbol, struct ui_file *stream)
+/* Print a natural-language description of SYMBOL to STREAM. This
+ version applies when there is a list of different locations, each
+ with a specified address range. */
+
+static void
+loclist_describe_location (struct symbol *symbol, CORE_ADDR addr,
+ struct ui_file *stream)
{
- /* FIXME: Could print the entire list of locations. */
- fprintf_filtered (stream, "a variable with multiple locations");
- return 1;
+ struct dwarf2_loclist_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
+ CORE_ADDR low, high;
+ const gdb_byte *loc_ptr, *buf_end;
+ int length, first = 1;
+ struct objfile *objfile = dwarf2_per_cu_objfile (dlbaton->per_cu);
+ struct gdbarch *gdbarch = get_objfile_arch (objfile);
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu);
+ CORE_ADDR base_mask = ~(~(CORE_ADDR)1 << (addr_size * 8 - 1));
+ /* Adjust base_address for relocatable objects. */
+ CORE_ADDR base_offset = ANOFFSET (objfile->section_offsets,
+ SECT_OFF_TEXT (objfile));
+ CORE_ADDR base_address = dlbaton->base_address + base_offset;
+
+ loc_ptr = dlbaton->data;
+ buf_end = dlbaton->data + dlbaton->size;
+
+ fprintf_filtered (stream, _("multi-location ("));
+
+ /* Iterate through locations until we run out. */
+ while (1)
+ {
+ if (buf_end - loc_ptr < 2 * addr_size)
+ error (_("Corrupted DWARF expression for symbol \"%s\"."),
+ SYMBOL_PRINT_NAME (symbol));
+
+ low = extract_unsigned_integer (loc_ptr, addr_size, byte_order);
+ loc_ptr += addr_size;
+
+ /* A base-address-selection entry. */
+ if (low == base_mask)
+ {
+ base_address = dwarf2_read_address (gdbarch,
+ loc_ptr, buf_end, addr_size);
+ fprintf_filtered (stream, _("[base address %s]"),
+ paddress (gdbarch, base_address));
+ loc_ptr += addr_size;
+ continue;
+ }
+
+ high = extract_unsigned_integer (loc_ptr, addr_size, byte_order);
+ loc_ptr += addr_size;
+
+ /* An end-of-list entry. */
+ if (low == 0 && high == 0)
+ {
+ /* Indicate the end of the list, for readability. */
+ fprintf_filtered (stream, _(")"));
+ return;
+ }
+
+ /* Otherwise, a location expression entry. */
+ low += base_address;
+ high += base_address;
+
+ length = extract_unsigned_integer (loc_ptr, 2, byte_order);
+ loc_ptr += 2;
+
+ /* Separate the different locations with a semicolon. */
+ if (first)
+ first = 0;
+ else
+ fprintf_filtered (stream, _("; "));
+
+ /* (It would improve readability to print only the minimum
+ necessary digits of the second number of the range.) */
+ fprintf_filtered (stream, _("range %s-%s, "),
+ paddress (gdbarch, low), paddress (gdbarch, high));
+
+ /* Now describe this particular location. */
+ locexpr_describe_location_1 (symbol, low, stream, loc_ptr, length,
+ objfile, addr_size);
+
+ loc_ptr += length;
+ }
}
/* Describe the location of SYMBOL as an agent value in VALUE, generating
any necessary bytecode in AX. */
static void
-loclist_tracepoint_var_ref (struct symbol * symbol, struct agent_expr * ax,
- struct axs_value * value)
+loclist_tracepoint_var_ref (struct symbol *symbol, struct gdbarch *gdbarch,
+ struct agent_expr *ax, struct axs_value *value)
{
struct dwarf2_loclist_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
- gdb_byte *data;
+ const gdb_byte *data;
size_t size;
data = find_location_expression (dlbaton, &size, ax->scope);
- if (data == NULL)
- error (_("Variable \"%s\" is not available."), SYMBOL_NATURAL_NAME (symbol));
- dwarf2_tracepoint_var_ref (symbol, ax, value, data, size);
+ dwarf2_tracepoint_var_ref (symbol, gdbarch, ax, value, data, size);
}
/* The set of location functions used with the DWARF-2 expression
evaluator and location lists. */
-const struct symbol_ops dwarf2_loclist_funcs = {
+const struct symbol_computed_ops dwarf2_loclist_funcs = {
loclist_read_variable,
loclist_read_needs_frame,
loclist_describe_location,
projects / binutils-gdb.git / blobdiff