#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 "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 char *
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;
CORE_ADDR base_mask = ~(~(CORE_ADDR)1 << (addr_size * 8 - 1));
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;
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_unsigned_integer (buf, regsize);
return result;
}
static void
dwarf_expr_read_mem (void *baton, char *buf, CORE_ADDR addr, size_t len)
{
read_memory (addr, buf, len);
}
static void
dwarf_expr_frame_base (void *baton, unsigned char **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;
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;
}
static struct value *
dwarf2_evaluate_loc_desc (struct symbol *var, struct frame_info *frame,
unsigned char *data, unsigned short size,
struct objfile *objfile)
{
CORE_ADDR result;
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;
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);
result = dwarf_expr_fetch (ctx, 0);
if (ctx->in_reg)
{
int regnum = DWARF2_REG_TO_REGNUM (result);
retval = value_from_register (SYMBOL_TYPE (var), regnum, frame);
}
else
{
retval = allocate_value (SYMBOL_TYPE (var));
VALUE_BFD_SECTION (retval) = SYMBOL_BFD_SECTION (var);
VALUE_LVAL (retval) = lval_memory;
VALUE_LAZY (retval) = 1;
VALUE_ADDRESS (retval) = result;
}
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, char *buf, CORE_ADDR addr, size_t len)
{
memset (buf, 0, len);
}
static void
needs_frame_frame_base (void *baton, unsigned char **start, size_t * length)
{
static char 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 (unsigned char *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;
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, unsigned char *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;
unsigned char *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;
unsigned char *data;
size_t size;
data = find_location_expression (dlbaton, &size,
frame ? get_frame_pc (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);
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);
unsigned char *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
};