/* DWARF 2 location expression support for GDB.
- Copyright 2003 Free Software Foundation, Inc.
+
+ Copyright (C) 2003, 2005, 2007, 2008, 2009, 2010
+ Free Software Foundation, Inc.
+
Contributed by Daniel Jacobowitz, MontaVista Software, Inc.
This file is part of GDB.
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., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "ui-out.h"
#include "gdbcore.h"
#include "target.h"
#include "inferior.h"
-
-#include "elf/dwarf2.h"
+#include "ax.h"
+#include "ax-gdb.h"
+#include "regcache.h"
+#include "objfiles.h"
+#include "exceptions.h"
+#include "block.h"
+
+#include "dwarf2.h"
#include "dwarf2expr.h"
#include "dwarf2loc.h"
+#include "dwarf2-frame.h"
#include "gdb_string.h"
+#include "gdb_assert.h"
+
+static void
+dwarf_expr_frame_base_1 (struct symbol *framefunc, CORE_ADDR pc,
+ gdb_byte **start, size_t *length);
-#ifndef DWARF2_REG_TO_REGNUM
-#define DWARF2_REG_TO_REGNUM(REG) (REG)
-#endif
+/* A helper function for dealing with location lists. Given a
+ symbol baton (BATON) and a pc value (PC), find the appropriate
+ location expression, set *LOCEXPR_LENGTH, and return a pointer
+ to the beginning of the expression. Returns NULL on failure.
+
+ For now, only return the first matching location expression; there
+ can be more than one in the list. */
+
+static 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;
+ int length;
+ 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 (objfile->section_offsets,
+ SECT_OFF_TEXT (objfile));
+ CORE_ADDR base_address = baton->base_address + base_offset;
+
+ loc_ptr = baton->data;
+ buf_end = baton->data + baton->size;
+
+ while (1)
+ {
+ if (buf_end - loc_ptr < 2 * addr_size)
+ error (_("find_location_expression: Corrupted DWARF expression."));
+
+ 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);
+ 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, byte_order);
+ loc_ptr += 2;
+
+ if (pc >= low && pc < high)
+ {
+ *locexpr_length = length;
+ return loc_ptr;
+ }
+
+ loc_ptr += length;
+ }
+}
/* This is the baton used when performing dwarf2 expression
evaluation. */
/* Helper functions for dwarf2_evaluate_loc_desc. */
-/* Using the frame specified in BATON, read register REGNUM. The lval
- type will be returned in LVALP, and for lval_memory the register
- save address will be returned in ADDRP. */
+/* Using the frame specified in BATON, return the value of register
+ REGNUM, treated as a pointer. */
static CORE_ADDR
-dwarf_expr_read_reg (void *baton, int regnum, enum lval_type *lvalp,
- CORE_ADDR *addrp)
+dwarf_expr_read_reg (void *baton, int dwarf_regnum)
{
- CORE_ADDR result;
struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton;
- char *buf = (char *) alloca (MAX_REGISTER_RAW_SIZE);
- int optimized, realnum;
-
- frame_register (debaton->frame, DWARF2_REG_TO_REGNUM (regnum),
- &optimized, lvalp, addrp, &realnum, buf);
- result = extract_address (buf, REGISTER_RAW_SIZE (regnum));
+ struct gdbarch *gdbarch = get_frame_arch (debaton->frame);
+ CORE_ADDR result;
+ int regnum;
+ regnum = gdbarch_dwarf2_reg_to_regnum (gdbarch, dwarf_regnum);
+ result = address_from_register (builtin_type (gdbarch)->builtin_data_ptr,
+ regnum, debaton->frame);
return result;
}
/* Read memory at ADDR (length LEN) into BUF. */
static void
-dwarf_expr_read_mem (void *baton, char *buf, CORE_ADDR addr, size_t len)
+dwarf_expr_read_mem (void *baton, gdb_byte *buf, CORE_ADDR addr, size_t len)
{
read_memory (addr, buf, len);
}
describing the frame base. Return a pointer to it in START and
its length in LENGTH. */
static void
-dwarf_expr_frame_base (void *baton, unsigned char **start, size_t * length)
+dwarf_expr_frame_base (void *baton, 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
+ this_base method. */
struct symbol *framefunc;
- struct dwarf2_locexpr_baton *symbaton;
struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton;
- framefunc = get_frame_function (debaton->frame);
- symbaton = SYMBOL_LOCATION_BATON (framefunc);
- *start = symbaton->data;
- *length = symbaton->size;
+
+ /* 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);
+
+ 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,
+ 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;
+
+ symbaton = SYMBOL_LOCATION_BATON (framefunc);
+ *start = find_location_expression (symbaton, length, pc);
+ }
+ else
+ {
+ struct dwarf2_locexpr_baton *symbaton;
+ symbaton = SYMBOL_LOCATION_BATON (framefunc);
+ if (symbaton != NULL)
+ {
+ *length = symbaton->size;
+ *start = symbaton->data;
+ }
+ else
+ *start = NULL;
+ }
+
+ if (*start == NULL)
+ error (_("Could not find the frame base for \"%s\"."),
+ 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
dwarf_expr_tls_address (void *baton, CORE_ADDR offset)
{
struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton;
- CORE_ADDR addr;
- if (target_get_thread_local_address_p ())
- addr = target_get_thread_local_address (inferior_ptid,
- debaton->objfile,
- offset);
- else
- error ("Cannot find thread-local variables on this target");
+ return target_translate_tls_address (debaton->objfile, offset);
+}
+
+struct piece_closure
+{
+ /* The number of pieces used to describe this variable. */
+ int n_pieces;
+
+ /* The architecture, used only for DWARF_VALUE_STACK. */
+ struct gdbarch *arch;
+
+ /* 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,
+ struct gdbarch *arch)
+{
+ struct piece_closure *c = XZALLOC (struct piece_closure);
+
+ c->n_pieces = n_pieces;
+ c->arch = arch;
+ c->pieces = XCALLOC (n_pieces, struct dwarf_expr_piece);
+
+ memcpy (c->pieces, pieces, n_pieces * sizeof (struct dwarf_expr_piece));
+
+ return c;
+}
+
+static void
+read_pieced_value (struct value *v)
+{
+ int i;
+ long offset = 0;
+ 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));
+
+ contents = value_contents_raw (v);
+ for (i = 0; i < c->n_pieces; i++)
+ {
+ struct dwarf_expr_piece *p = &c->pieces[i];
+ 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 = 0;
+
+ if (gdbarch_byte_order (arch) == BFD_ENDIAN_BIG
+ && p->size < register_size (arch, gdb_regnum))
+ /* Big-endian, and we want less than full size. */
+ reg_offset = register_size (arch, gdb_regnum) - p->size;
+
+ get_frame_register_bytes (frame, gdb_regnum, reg_offset, p->size,
+ contents + offset);
+ }
+ break;
+
+ case DWARF_VALUE_MEMORY:
+ if (p->v.expr.in_stack_memory)
+ read_stack (p->v.expr.value, contents + offset, p->size);
+ else
+ read_memory (p->v.expr.value, contents + offset, p->size);
+ break;
+
+ case DWARF_VALUE_STACK:
+ {
+ size_t n;
+ int addr_size = gdbarch_addr_bit (c->arch) / 8;
+ n = p->size;
+ if (n > addr_size)
+ n = addr_size;
+ store_unsigned_integer (contents + offset, n,
+ gdbarch_byte_order (c->arch),
+ p->v.expr.value);
+ }
+ break;
+
+ case DWARF_VALUE_LITERAL:
+ {
+ size_t n = p->size;
+ if (n > p->v.literal.length)
+ n = p->v.literal.length;
+ memcpy (contents + offset, p->v.literal.data, n);
+ }
+ break;
+
+ default:
+ internal_error (__FILE__, __LINE__, _("invalid location type"));
+ }
+ offset += p->size;
+ }
+}
+
+static void
+write_pieced_value (struct value *to, struct value *from)
+{
+ int i;
+ long offset = 0;
+ 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));
+
+ if (frame == NULL)
+ {
+ set_value_optimized_out (to, 1);
+ return;
+ }
- return addr;
+ contents = value_contents_raw (from);
+ for (i = 0; i < c->n_pieces; i++)
+ {
+ struct dwarf_expr_piece *p = &c->pieces[i];
+ 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 = 0;
+
+ if (gdbarch_byte_order (arch) == BFD_ENDIAN_BIG
+ && p->size < register_size (arch, gdb_regnum))
+ /* Big-endian, and we want less than full size. */
+ reg_offset = register_size (arch, gdb_regnum) - p->size;
+
+ put_frame_register_bytes (frame, gdb_regnum, reg_offset, p->size,
+ contents + offset);
+ }
+ break;
+ case DWARF_VALUE_MEMORY:
+ write_memory (p->v.expr.value, contents + offset, p->size);
+ break;
+ default:
+ set_value_optimized_out (to, 1);
+ return;
+ }
+ offset += p->size;
+ }
+}
+
+static void *
+copy_pieced_value_closure (struct value *v)
+{
+ struct piece_closure *c = (struct piece_closure *) value_computed_closure (v);
+
+ return allocate_piece_closure (c->n_pieces, c->pieces, c->arch);
+}
+
+static void
+free_pieced_value_closure (struct value *v)
+{
+ struct piece_closure *c = (struct piece_closure *) value_computed_closure (v);
+
+ 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
of FRAME. */
static struct value *
dwarf2_evaluate_loc_desc (struct symbol *var, struct frame_info *frame,
- unsigned char *data, unsigned short size,
- struct objfile *objfile)
+ gdb_byte *data, unsigned short size,
+ struct dwarf2_per_cu_data *per_cu)
{
- CORE_ADDR result;
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));
+ 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);
-
- retval = allocate_value (SYMBOL_TYPE (var));
- VALUE_BFD_SECTION (retval) = SYMBOL_BFD_SECTION (var);
-
- if (ctx->in_reg)
+ if (ctx->num_pieces > 0)
{
- store_unsigned_integer (VALUE_CONTENTS_RAW (retval),
- TYPE_LENGTH (SYMBOL_TYPE (var)),
- dwarf_expr_fetch (ctx, 0));
- VALUE_LVAL (retval) = lval_register;
- VALUE_REGNO (retval) = ctx->regnum;
+ struct piece_closure *c;
+ struct frame_id frame_id = get_frame_id (frame);
+
+ c = allocate_piece_closure (ctx->num_pieces, ctx->pieces, ctx->gdbarch);
+ retval = allocate_computed_value (SYMBOL_TYPE (var),
+ &pieced_value_funcs,
+ c);
+ VALUE_FRAME_ID (retval) = frame_id;
}
else
{
- result = dwarf_expr_fetch (ctx, 0);
- VALUE_LVAL (retval) = lval_memory;
- VALUE_LAZY (retval) = 1;
- VALUE_ADDRESS (retval) = result;
+ 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);
+ retval = value_from_register (SYMBOL_TYPE (var), gdb_regnum, frame);
+ }
+ 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 (SYMBOL_TYPE (var));
+ 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 (SYMBOL_TYPE (var));
+ contents = value_contents_raw (retval);
+ if (n > TYPE_LENGTH (SYMBOL_TYPE (var)))
+ n = TYPE_LENGTH (SYMBOL_TYPE (var));
+ 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 (SYMBOL_TYPE (var));
+ contents = value_contents_raw (retval);
+ if (n > TYPE_LENGTH (SYMBOL_TYPE (var)))
+ n = TYPE_LENGTH (SYMBOL_TYPE (var));
+ memcpy (contents, ctx->data, n);
+ }
+ break;
+
+ default:
+ internal_error (__FILE__, __LINE__, _("invalid location type"));
+ }
}
- free_dwarf_expr_context (ctx);
+ set_value_initialized (retval, ctx->initialized);
+
+ do_cleanups (old_chain);
return retval;
}
-
-
-
-
\f
/* Helper functions and baton for dwarf2_loc_desc_needs_frame. */
/* Reads from registers do require a frame. */
static CORE_ADDR
-needs_frame_read_reg (void *baton, int regnum, enum lval_type *lvalp,
- CORE_ADDR *addrp)
+needs_frame_read_reg (void *baton, int regnum)
{
struct needs_frame_baton *nf_baton = baton;
nf_baton->needs_frame = 1;
/* Reads from memory do not require a frame. */
static void
-needs_frame_read_mem (void *baton, char *buf, CORE_ADDR addr, size_t len)
+needs_frame_read_mem (void *baton, gdb_byte *buf, CORE_ADDR addr, size_t len)
{
memset (buf, 0, len);
}
/* Frame-relative accesses do require a frame. */
static void
-needs_frame_frame_base (void *baton, unsigned char **start, size_t * length)
+needs_frame_frame_base (void *baton, gdb_byte **start, size_t * length)
{
- static char lit0 = DW_OP_lit0;
+ static gdb_byte lit0 = DW_OP_lit0;
struct needs_frame_baton *nf_baton = baton;
*start = &lit0;
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)
requires a frame to evaluate. */
static int
-dwarf2_loc_desc_needs_frame (unsigned char *data, unsigned short size)
+dwarf2_loc_desc_needs_frame (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);
- free_dwarf_expr_context (ctx);
+ in_reg = ctx->location == DWARF_VALUE_REGISTER;
+
+ if (ctx->num_pieces > 0)
+ {
+ int i;
+
+ /* 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].location == DWARF_VALUE_REGISTER)
+ in_reg = 1;
+ }
+
+ do_cleanups (old_chain);
- return baton.needs_frame;
+ return baton.needs_frame || in_reg;
}
+static void
+dwarf2_tracepoint_var_ref (struct symbol *symbol, struct gdbarch *gdbarch,
+ struct agent_expr *ax, struct axs_value *value,
+ gdb_byte *data, int size)
+{
+ if (size == 0)
+ error (_("Symbol \"%s\" has been optimized out."),
+ SYMBOL_PRINT_NAME (symbol));
+
+ if (size == 1
+ && data[0] >= DW_OP_reg0
+ && data[0] <= DW_OP_reg31)
+ {
+ value->kind = axs_lvalue_register;
+ value->u.reg = data[0] - DW_OP_reg0;
+ }
+ else if (data[0] == DW_OP_regx)
+ {
+ ULONGEST reg;
+ read_uleb128 (data + 1, data + size, ®);
+ value->kind = axs_lvalue_register;
+ value->u.reg = reg;
+ }
+ else if (data[0] == DW_OP_fbreg)
+ {
+ struct block *b;
+ struct symbol *framefunc;
+ int frame_reg = 0;
+ LONGEST frame_offset;
+ gdb_byte *buf_end;
+ gdb_byte *base_data;
+ size_t base_size;
+ LONGEST base_offset = 0;
+
+ 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)
+ {
+ 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
+ {
+ /* 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"),
+ SYMBOL_PRINT_NAME (symbol));
+ }
+
+ 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));
+
+ ax_reg (ax, frame_reg);
+ ax_const_l (ax, base_offset + frame_offset);
+ ax_simple (ax, aop_add);
+
+ value->kind = axs_lvalue_memory;
+ }
+ 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);
+ value->kind = axs_lvalue_memory;
+ }
+ else
+ error (_("Unsupported DWARF opcode 0x%x in the location of \"%s\"."),
+ data[0], SYMBOL_PRINT_NAME (symbol));
+}
\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);
+ 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. */
{
/* FIXME: be more extensive. */
struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
+ int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu);
if (dlbaton->size == 1
&& dlbaton->data[0] >= DW_OP_reg0
&& dlbaton->data[0] <= DW_OP_reg31)
{
- int regno = DWARF2_REG_TO_REGNUM (dlbaton->data[0] - DW_OP_reg0);
+ struct objfile *objfile = dwarf2_per_cu_objfile (dlbaton->per_cu);
+ struct gdbarch *gdbarch = get_objfile_arch (objfile);
+ int regno = gdbarch_dwarf2_reg_to_regnum (gdbarch,
+ dlbaton->data[0] - DW_OP_reg0);
fprintf_filtered (stream,
- "a variable in register %s", REGISTER_NAME (regno));
+ "a variable in register %s",
+ gdbarch_register_name (gdbarch, regno));
return 1;
}
+ /* The location expression for a TLS variable looks like this (on a
+ 64-bit LE machine):
+
+ DW_AT_location : 10 byte block: 3 4 0 0 0 0 0 0 0 e0
+ (DW_OP_addr: 4; DW_OP_GNU_push_tls_address)
+
+ 0x3 is the encoding for DW_OP_addr, which has an operand as long
+ as the size of an address on the target machine (here is 8
+ bytes). 0xe0 is the encoding for DW_OP_GNU_push_tls_address.
+ 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)
+ {
+ struct objfile *objfile = dwarf2_per_cu_objfile (dlbaton->per_cu);
+ struct gdbarch *gdbarch = get_objfile_arch (objfile);
+ CORE_ADDR offset = dwarf2_read_address (gdbarch,
+ &dlbaton->data[1],
+ &dlbaton->data[dlbaton->size - 1],
+ addr_size);
+ fprintf_filtered (stream,
+ "a thread-local variable at offset %s in the "
+ "thread-local storage for `%s'",
+ paddress (gdbarch, offset), objfile->name);
+ return 1;
+ }
+
+
fprintf_filtered (stream,
"a variable with complex or multiple locations (DWARF2)");
return 1;
}
+
+/* Describe the location of SYMBOL as an agent value in VALUE, generating
+ any necessary bytecode in AX.
+
+ 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. */
+
+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. */
-struct location_funcs dwarf2_locexpr_funcs = {
+const struct symbol_computed_ops dwarf2_locexpr_funcs = {
locexpr_read_variable,
locexpr_read_needs_frame,
locexpr_describe_location,
- NULL
+ locexpr_tracepoint_var_ref
+};
+
+
+/* Wrapper functions for location lists. These generally find
+ the appropriate location expression and call something above. */
+
+/* Return the value of SYMBOL in FRAME using the DWARF-2 expression
+ evaluator to calculate the location. */
+static struct value *
+loclist_read_variable (struct symbol *symbol, struct frame_info *frame)
+{
+ struct dwarf2_loclist_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
+ struct value *val;
+ gdb_byte *data;
+ size_t size;
+
+ data = find_location_expression (dlbaton, &size,
+ frame ? get_frame_address_in_block (frame)
+ : 0);
+ if (data == NULL)
+ {
+ val = allocate_value (SYMBOL_TYPE (symbol));
+ VALUE_LVAL (val) = not_lval;
+ set_value_optimized_out (val, 1);
+ }
+ else
+ val = dwarf2_evaluate_loc_desc (symbol, frame, data, size,
+ dlbaton->per_cu);
+
+ return val;
+}
+
+/* Return non-zero iff we need a frame to evaluate SYMBOL. */
+static int
+loclist_read_needs_frame (struct symbol *symbol)
+{
+ /* If there's a location list, then assume we need to have a frame
+ to choose the appropriate location expression. With tracking of
+ global variables this is not necessarily true, but such tracking
+ is disabled in GCC at the moment until we figure out how to
+ represent it. */
+
+ return 1;
+}
+
+/* Print a natural-language description of SYMBOL to STREAM. */
+static int
+loclist_describe_location (struct symbol *symbol, struct ui_file *stream)
+{
+ /* FIXME: Could print the entire list of locations. */
+ fprintf_filtered (stream, "a variable with multiple locations");
+ return 1;
+}
+
+/* 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 gdbarch *gdbarch,
+ struct agent_expr *ax, struct axs_value *value)
+{
+ struct dwarf2_loclist_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
+ 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, gdbarch, ax, value, data, size);
+}
+
+/* The set of location functions used with the DWARF-2 expression
+ evaluator and location lists. */
+const struct symbol_computed_ops dwarf2_loclist_funcs = {
+ loclist_read_variable,
+ loclist_read_needs_frame,
+ loclist_describe_location,
+ loclist_tracepoint_var_ref
};