/* DWARF 2 location expression support for GDB.
- Copyright 2003 Free Software Foundation, Inc.
+
+ Copyright (C) 2003, 2005, 2007, 2008, 2009 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 "ax.h"
#include "ax-gdb.h"
#include "regcache.h"
+#include "objfiles.h"
+#include "exceptions.h"
#include "elf/dwarf2.h"
#include "dwarf2expr.h"
#include "dwarf2loc.h"
#include "gdb_string.h"
-
-#ifndef DWARF2_REG_TO_REGNUM
-#define DWARF2_REG_TO_REGNUM(REG) (REG)
-#endif
+#include "gdb_assert.h"
/* 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 char *
+static gdb_byte *
find_location_expression (struct dwarf2_loclist_baton *baton,
size_t *locexpr_length, CORE_ADDR pc)
{
- CORE_ADDR base_address = baton->base_address;
CORE_ADDR low, high;
- char *loc_ptr, *buf_end;
- unsigned int addr_size = TARGET_ADDR_BIT / TARGET_CHAR_BIT, length;
+ 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);
+ 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)
{
- low = dwarf2_read_address (loc_ptr, buf_end, &length);
- loc_ptr += length;
- high = dwarf2_read_address (loc_ptr, buf_end, &length);
- loc_ptr += length;
+ low = dwarf2_read_address (gdbarch, loc_ptr, buf_end, addr_size);
+ loc_ptr += addr_size;
+ high = dwarf2_read_address (gdbarch, loc_ptr, buf_end, addr_size);
+ loc_ptr += addr_size;
/* An end-of-list entry. */
if (low == 0 && high == 0)
/* 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 dwarf_regnum)
{
struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton;
- CORE_ADDR result, save_addr;
- enum lval_type lval_type;
- char *buf;
- int optimized, regnum, realnum, regsize;
-
- regnum = DWARF2_REG_TO_REGNUM (dwarf_regnum);
- regsize = register_size (current_gdbarch, regnum);
- buf = (char *) alloca (regsize);
-
- frame_register (debaton->frame, regnum, &optimized, &lval_type, &save_addr,
- &realnum, buf);
- result = extract_address (buf, regsize);
+ 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
framefunc = get_frame_function (debaton->frame);
- if (SYMBOL_LOCATION_FUNCS (framefunc) == &dwarf2_loclist_funcs)
+ /* 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)
{
struct dwarf2_loclist_baton *symbaton;
+ struct frame_info *frame = debaton->frame;
+
symbaton = SYMBOL_LOCATION_BATON (framefunc);
*start = find_location_expression (symbaton, length,
- get_frame_pc (debaton->frame));
+ get_frame_address_in_block (frame));
}
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)
- error ("Could not find the frame base for \"%s\".",
+ error (_("Could not find the frame base for \"%s\"."),
SYMBOL_NATURAL_NAME (framefunc));
}
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 addr;
+ return target_translate_tls_address (debaton->objfile, offset);
}
/* Evaluate a location description, starting at DATA and with length
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;
{
retval = allocate_value (SYMBOL_TYPE (var));
VALUE_LVAL (retval) = not_lval;
- VALUE_OPTIMIZED_OUT (retval) = 1;
+ 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 ();
+ 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_tls_address = dwarf_expr_tls_address;
dwarf_expr_eval (ctx, data, size);
- result = dwarf_expr_fetch (ctx, 0);
+ if (ctx->num_pieces > 0)
+ {
+ int i;
+ long offset = 0;
+ bfd_byte *contents;
- if (ctx->in_reg)
+ 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)
+ {
+ struct gdbarch *arch = get_frame_arch (frame);
+ bfd_byte regval[MAX_REGISTER_SIZE];
+ int gdb_regnum = gdbarch_dwarf2_reg_to_regnum (arch, 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)
{
- int regnum = DWARF2_REG_TO_REGNUM (result);
- retval = value_from_register (SYMBOL_TYPE (var), regnum, frame);
+ 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);
}
else
{
- retval = allocate_value (SYMBOL_TYPE (var));
- VALUE_BFD_SECTION (retval) = SYMBOL_BFD_SECTION (var);
+ CORE_ADDR address = dwarf_expr_fetch (ctx, 0);
+ retval = allocate_value (SYMBOL_TYPE (var));
VALUE_LVAL (retval) = lval_memory;
- VALUE_LAZY (retval) = 1;
- VALUE_ADDRESS (retval) = result;
+ set_value_lazy (retval, 1);
+ VALUE_ADDRESS (retval) = address;
}
+ set_value_initialized (retval, ctx->initialized);
+
free_dwarf_expr_context (ctx);
return retval;
/* 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;
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;
baton.needs_frame = 0;
ctx = new_dwarf_expr_context ();
+ 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;
dwarf_expr_eval (ctx, data, size);
+ in_reg = ctx->in_reg;
+
+ 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].in_reg)
+ in_reg = 1;
+ }
+
free_dwarf_expr_context (ctx);
- return baton.needs_frame;
+ return baton.needs_frame || in_reg;
}
static void
-dwarf2_tracepoint_var_ref (struct symbol * symbol, struct agent_expr * ax,
- struct axs_value * value, unsigned char *data,
+dwarf2_tracepoint_var_ref (struct symbol *symbol, struct agent_expr *ax,
+ struct axs_value *value, gdb_byte *data,
int size)
{
if (size == 0)
- error ("Symbol \"%s\" has been optimized out.",
+ error (_("Symbol \"%s\" has been optimized out."),
SYMBOL_PRINT_NAME (symbol));
if (size == 1
as above. */
int frame_reg;
LONGEST frame_offset;
- unsigned char *buf_end;
+ gdb_byte *buf_end;
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\".",
+ error (_("Unexpected opcode after DW_OP_fbreg for symbol \"%s\"."),
SYMBOL_PRINT_NAME (symbol));
- TARGET_VIRTUAL_FRAME_POINTER (ax->scope, &frame_reg, &frame_offset);
+ gdbarch_virtual_frame_pointer (current_gdbarch,
+ ax->scope, &frame_reg, &frame_offset);
ax_reg (ax, frame_reg);
ax_const_l (ax, frame_offset);
ax_simple (ax, aop_add);
- ax_const_l (ax, frame_offset);
+ 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 in the location of \"%s\".",
- SYMBOL_PRINT_NAME (symbol));
+ 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
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'",
+ paddr_nz (offset), objfile->name);
+ return 1;
+ }
+
+
fprintf_filtered (stream,
"a variable with complex or multiple locations (DWARF2)");
return 1;
/* The set of location functions used with the DWARF-2 expression
evaluator. */
-struct location_funcs dwarf2_locexpr_funcs = {
+const struct symbol_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;
- unsigned char *data;
+ gdb_byte *data;
size_t size;
data = find_location_expression (dlbaton, &size,
- frame ? get_frame_pc (frame) : 0);
+ frame ? get_frame_address_in_block (frame)
+ : 0);
if (data == NULL)
- error ("Variable \"%s\" is not available.", SYMBOL_NATURAL_NAME (symbol));
-
- val = dwarf2_evaluate_loc_desc (symbol, frame, data, size, dlbaton->objfile);
+ {
+ 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;
}
struct axs_value * value)
{
struct dwarf2_loclist_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
- unsigned char *data;
+ 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));
+ error (_("Variable \"%s\" is not available."), SYMBOL_NATURAL_NAME (symbol));
dwarf2_tracepoint_var_ref (symbol, ax, value, data, size);
}
/* The set of location functions used with the DWARF-2 expression
evaluator and location lists. */
-struct location_funcs dwarf2_loclist_funcs = {
+const struct symbol_ops dwarf2_loclist_funcs = {
loclist_read_variable,
loclist_read_needs_frame,
loclist_describe_location,
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