#include "defs.h"
#include "ui-out.h"
#include "value.h"
#include "frame.h"
#include "gdbcore.h"
#include "target.h"
#include "inferior.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
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;
unsigned int addr_size = TARGET_ADDR_BIT / TARGET_CHAR_BIT;
CORE_ADDR base_mask = ~(~(CORE_ADDR)1 << (addr_size * 8 - 1));
CORE_ADDR base_offset = ANOFFSET (baton->objfile->section_offsets,
SECT_OFF_TEXT (baton->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;
if (low == 0 && high == 0)
return NULL;
if ((low & base_mask) == base_mask)
{
base_address = high;
continue;
}
low += base_address;
high += base_address;
length = extract_unsigned_integer (loc_ptr, 2);
loc_ptr += 2;
if (pc >= low && pc < high)
{
*locexpr_length = length;
return loc_ptr;
}
loc_ptr += length;
}
}
struct dwarf_expr_baton
{
struct frame_info *frame;
struct objfile *objfile;
};
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;
gdb_byte *buf;
int optimized, regnum, realnum, regsize;
regnum = DWARF2_REG_TO_REGNUM (dwarf_regnum);
regsize = register_size (current_gdbarch, regnum);
buf = alloca (regsize);
frame_register (debaton->frame, regnum, &optimized, &lval_type, &save_addr,
&realnum, buf);
result = extract_unsigned_integer (buf, regsize);
return result;
}
static void
dwarf_expr_read_mem (void *baton, gdb_byte *buf, CORE_ADDR addr, size_t len)
{
read_memory (addr, buf, len);
}
static void
dwarf_expr_frame_base (void *baton, gdb_byte **start, size_t * length)
{
struct symbol *framefunc;
struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton;
framefunc = get_frame_function (debaton->frame);
if (SYMBOL_OPS (framefunc) == &dwarf2_loclist_funcs)
{
struct dwarf2_loclist_baton *symbaton;
symbaton = SYMBOL_LOCATION_BATON (framefunc);
*start = find_location_expression (symbaton, length,
get_frame_pc (debaton->frame));
}
else
{
struct dwarf2_locexpr_baton *symbaton;
symbaton = SYMBOL_LOCATION_BATON (framefunc);
*length = symbaton->size;
*start = symbaton->data;
}
if (*start == NULL)
error (_("Could not find the frame base for \"%s\"."),
SYMBOL_NATURAL_NAME (framefunc));
}
static CORE_ADDR
dwarf_expr_tls_address (void *baton, CORE_ADDR offset)
{
struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton;
volatile CORE_ADDR addr = 0;
if (target_get_thread_local_address_p ()
&& gdbarch_fetch_tls_load_module_address_p (current_gdbarch))
{
ptid_t ptid = inferior_ptid;
struct objfile *objfile = debaton->objfile;
volatile struct gdb_exception ex;
TRY_CATCH (ex, RETURN_MASK_ALL)
{
CORE_ADDR lm_addr;
lm_addr = gdbarch_fetch_tls_load_module_address (current_gdbarch,
objfile);
if (lm_addr == 0)
throw_error (TLS_LOAD_MODULE_NOT_FOUND_ERROR,
_("TLS load module not found"));
addr = target_get_thread_local_address (ptid, lm_addr, offset);
}
if (ex.reason < 0)
{
int objfile_is_library = (objfile->flags & OBJF_SHARED);
switch (ex.error)
{
case TLS_NO_LIBRARY_SUPPORT_ERROR:
error (_("Cannot find thread-local variables in this thread library."));
break;
case TLS_LOAD_MODULE_NOT_FOUND_ERROR:
if (objfile_is_library)
error (_("Cannot find shared library `%s' in dynamic"
" linker's load module list"), objfile->name);
else
error (_("Cannot find executable file `%s' in dynamic"
" linker's load module list"), objfile->name);
break;
case TLS_NOT_ALLOCATED_YET_ERROR:
if (objfile_is_library)
error (_("The inferior has not yet allocated storage for"
" thread-local variables in\n"
"the shared library `%s'\n"
"for %s"),
objfile->name, target_pid_to_str (ptid));
else
error (_("The inferior has not yet allocated storage for"
" thread-local variables in\n"
"the executable `%s'\n"
"for %s"),
objfile->name, target_pid_to_str (ptid));
break;
case TLS_GENERIC_ERROR:
if (objfile_is_library)
error (_("Cannot find thread-local storage for %s, "
"shared library %s:\n%s"),
target_pid_to_str (ptid),
objfile->name, ex.message);
else
error (_("Cannot find thread-local storage for %s, "
"executable file %s:\n%s"),
target_pid_to_str (ptid),
objfile->name, ex.message);
break;
default:
throw_exception (ex);
break;
}
}
}
else
error (_("Cannot find thread-local variables on this target"));
return addr;
}
static struct value *
dwarf2_evaluate_loc_desc (struct symbol *var, struct frame_info *frame,
gdb_byte *data, unsigned short size,
struct objfile *objfile)
{
struct gdbarch *arch = get_frame_arch (frame);
struct value *retval;
struct dwarf_expr_baton baton;
struct dwarf_expr_context *ctx;
if (size == 0)
{
retval = allocate_value (SYMBOL_TYPE (var));
VALUE_LVAL (retval) = not_lval;
set_value_optimized_out (retval, 1);
}
baton.frame = frame;
baton.objfile = objfile;
ctx = new_dwarf_expr_context ();
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_tls_address = dwarf_expr_tls_address;
dwarf_expr_eval (ctx, data, size);
if (ctx->num_pieces == 2
&& ctx->pieces[0].in_reg
&& ctx->pieces[1].in_reg
&& (ctx->pieces[0].value + 1) == ctx->pieces[1].value
&& CONVERT_REGISTER_P (ctx->pieces[0].value, SYMBOL_TYPE (var))
)
{
CORE_ADDR dwarf_regnum = ctx->pieces[0].value;
int gdb_regnum = DWARF2_REG_TO_REGNUM (dwarf_regnum);
retval = value_from_register (SYMBOL_TYPE (var), gdb_regnum, frame);
}
else
if (ctx->num_pieces > 0)
{
int i;
long offset = 0;
bfd_byte *contents;
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
{
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);
}
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;
}
free_dwarf_expr_context (ctx);
return retval;
}
struct needs_frame_baton
{
int needs_frame;
};
static CORE_ADDR
needs_frame_read_reg (void *baton, int regnum)
{
struct needs_frame_baton *nf_baton = baton;
nf_baton->needs_frame = 1;
return 1;
}
static void
needs_frame_read_mem (void *baton, gdb_byte *buf, CORE_ADDR addr, size_t len)
{
memset (buf, 0, len);
}
static void
needs_frame_frame_base (void *baton, gdb_byte **start, size_t * length)
{
static gdb_byte lit0 = DW_OP_lit0;
struct needs_frame_baton *nf_baton = baton;
*start = &lit0;
*length = 1;
nf_baton->needs_frame = 1;
}
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;
}
static int
dwarf2_loc_desc_needs_frame (gdb_byte *data, unsigned short size)
{
struct needs_frame_baton baton;
struct dwarf_expr_context *ctx;
int in_reg;
baton.needs_frame = 0;
ctx = new_dwarf_expr_context ();
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_tls_address = needs_frame_tls_address;
dwarf_expr_eval (ctx, data, size);
in_reg = ctx->in_reg;
if (ctx->num_pieces > 0)
{
int i;
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 || in_reg;
}
static void
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."),
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)
{
int frame_reg;
LONGEST frame_offset;
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\"."),
SYMBOL_PRINT_NAME (symbol));
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);
ax_const_l (ax, frame_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));
}
static struct value *
locexpr_read_variable (struct symbol *symbol, struct frame_info *frame)
{
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);
return val;
}
static int
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);
}
static int
locexpr_describe_location (struct symbol *symbol, struct ui_file *stream)
{
struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
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);
fprintf_filtered (stream,
"a variable in register %s", REGISTER_NAME (regno));
return 1;
}
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;
}
fprintf_filtered (stream,
"a variable with complex or multiple locations (DWARF2)");
return 1;
}
static void
locexpr_tracepoint_var_ref (struct symbol * symbol, struct agent_expr * ax,
struct axs_value * value)
{
struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
dwarf2_tracepoint_var_ref (symbol, ax, value, dlbaton->data, dlbaton->size);
}
const struct symbol_ops dwarf2_locexpr_funcs = {
locexpr_read_variable,
locexpr_read_needs_frame,
locexpr_describe_location,
locexpr_tracepoint_var_ref
};
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_pc (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->objfile);
return val;
}
static int
loclist_read_needs_frame (struct symbol *symbol)
{
return 1;
}
static int
loclist_describe_location (struct symbol *symbol, struct ui_file *stream)
{
fprintf_filtered (stream, "a variable with multiple locations");
return 1;
}
static void
loclist_tracepoint_var_ref (struct symbol * symbol, 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, ax, value, data, size);
}
const struct symbol_ops dwarf2_loclist_funcs = {
loclist_read_variable,
loclist_read_needs_frame,
loclist_describe_location,
loclist_tracepoint_var_ref
};