808 lines
23 KiB
C
808 lines
23 KiB
C
/* Find a variable's value in memory, for GDB, the GNU debugger.
|
||
|
||
Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994,
|
||
1995, 1996, 1997, 1998, 1999, 2000, 2001, 2003, 2004 Free Software
|
||
Foundation, 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.
|
||
|
||
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. */
|
||
|
||
#include "defs.h"
|
||
#include "symtab.h"
|
||
#include "gdbtypes.h"
|
||
#include "frame.h"
|
||
#include "value.h"
|
||
#include "gdbcore.h"
|
||
#include "inferior.h"
|
||
#include "target.h"
|
||
#include "gdb_string.h"
|
||
#include "gdb_assert.h"
|
||
#include "floatformat.h"
|
||
#include "symfile.h" /* for overlay functions */
|
||
#include "regcache.h"
|
||
#include "user-regs.h"
|
||
#include "block.h"
|
||
|
||
/* Basic byte-swapping routines. GDB has needed these for a long time...
|
||
All extract a target-format integer at ADDR which is LEN bytes long. */
|
||
|
||
#if TARGET_CHAR_BIT != 8 || HOST_CHAR_BIT != 8
|
||
/* 8 bit characters are a pretty safe assumption these days, so we
|
||
assume it throughout all these swapping routines. If we had to deal with
|
||
9 bit characters, we would need to make len be in bits and would have
|
||
to re-write these routines... */
|
||
you lose
|
||
#endif
|
||
|
||
LONGEST
|
||
extract_signed_integer (const void *addr, int len)
|
||
{
|
||
LONGEST retval;
|
||
const unsigned char *p;
|
||
const unsigned char *startaddr = addr;
|
||
const unsigned char *endaddr = startaddr + len;
|
||
|
||
if (len > (int) sizeof (LONGEST))
|
||
error ("\
|
||
That operation is not available on integers of more than %d bytes.",
|
||
(int) sizeof (LONGEST));
|
||
|
||
/* Start at the most significant end of the integer, and work towards
|
||
the least significant. */
|
||
if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG)
|
||
{
|
||
p = startaddr;
|
||
/* Do the sign extension once at the start. */
|
||
retval = ((LONGEST) * p ^ 0x80) - 0x80;
|
||
for (++p; p < endaddr; ++p)
|
||
retval = (retval << 8) | *p;
|
||
}
|
||
else
|
||
{
|
||
p = endaddr - 1;
|
||
/* Do the sign extension once at the start. */
|
||
retval = ((LONGEST) * p ^ 0x80) - 0x80;
|
||
for (--p; p >= startaddr; --p)
|
||
retval = (retval << 8) | *p;
|
||
}
|
||
return retval;
|
||
}
|
||
|
||
ULONGEST
|
||
extract_unsigned_integer (const void *addr, int len)
|
||
{
|
||
ULONGEST retval;
|
||
const unsigned char *p;
|
||
const unsigned char *startaddr = addr;
|
||
const unsigned char *endaddr = startaddr + len;
|
||
|
||
if (len > (int) sizeof (ULONGEST))
|
||
error ("\
|
||
That operation is not available on integers of more than %d bytes.",
|
||
(int) sizeof (ULONGEST));
|
||
|
||
/* Start at the most significant end of the integer, and work towards
|
||
the least significant. */
|
||
retval = 0;
|
||
if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG)
|
||
{
|
||
for (p = startaddr; p < endaddr; ++p)
|
||
retval = (retval << 8) | *p;
|
||
}
|
||
else
|
||
{
|
||
for (p = endaddr - 1; p >= startaddr; --p)
|
||
retval = (retval << 8) | *p;
|
||
}
|
||
return retval;
|
||
}
|
||
|
||
/* Sometimes a long long unsigned integer can be extracted as a
|
||
LONGEST value. This is done so that we can print these values
|
||
better. If this integer can be converted to a LONGEST, this
|
||
function returns 1 and sets *PVAL. Otherwise it returns 0. */
|
||
|
||
int
|
||
extract_long_unsigned_integer (const void *addr, int orig_len, LONGEST *pval)
|
||
{
|
||
char *p, *first_addr;
|
||
int len;
|
||
|
||
len = orig_len;
|
||
if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG)
|
||
{
|
||
for (p = (char *) addr;
|
||
len > (int) sizeof (LONGEST) && p < (char *) addr + orig_len;
|
||
p++)
|
||
{
|
||
if (*p == 0)
|
||
len--;
|
||
else
|
||
break;
|
||
}
|
||
first_addr = p;
|
||
}
|
||
else
|
||
{
|
||
first_addr = (char *) addr;
|
||
for (p = (char *) addr + orig_len - 1;
|
||
len > (int) sizeof (LONGEST) && p >= (char *) addr;
|
||
p--)
|
||
{
|
||
if (*p == 0)
|
||
len--;
|
||
else
|
||
break;
|
||
}
|
||
}
|
||
|
||
if (len <= (int) sizeof (LONGEST))
|
||
{
|
||
*pval = (LONGEST) extract_unsigned_integer (first_addr,
|
||
sizeof (LONGEST));
|
||
return 1;
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
|
||
/* Treat the bytes at BUF as a pointer of type TYPE, and return the
|
||
address it represents. */
|
||
CORE_ADDR
|
||
extract_typed_address (const void *buf, struct type *type)
|
||
{
|
||
if (TYPE_CODE (type) != TYPE_CODE_PTR
|
||
&& TYPE_CODE (type) != TYPE_CODE_REF)
|
||
internal_error (__FILE__, __LINE__,
|
||
"extract_typed_address: "
|
||
"type is not a pointer or reference");
|
||
|
||
return POINTER_TO_ADDRESS (type, buf);
|
||
}
|
||
|
||
|
||
void
|
||
store_signed_integer (void *addr, int len, LONGEST val)
|
||
{
|
||
unsigned char *p;
|
||
unsigned char *startaddr = (unsigned char *) addr;
|
||
unsigned char *endaddr = startaddr + len;
|
||
|
||
/* Start at the least significant end of the integer, and work towards
|
||
the most significant. */
|
||
if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG)
|
||
{
|
||
for (p = endaddr - 1; p >= startaddr; --p)
|
||
{
|
||
*p = val & 0xff;
|
||
val >>= 8;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
for (p = startaddr; p < endaddr; ++p)
|
||
{
|
||
*p = val & 0xff;
|
||
val >>= 8;
|
||
}
|
||
}
|
||
}
|
||
|
||
void
|
||
store_unsigned_integer (void *addr, int len, ULONGEST val)
|
||
{
|
||
unsigned char *p;
|
||
unsigned char *startaddr = (unsigned char *) addr;
|
||
unsigned char *endaddr = startaddr + len;
|
||
|
||
/* Start at the least significant end of the integer, and work towards
|
||
the most significant. */
|
||
if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG)
|
||
{
|
||
for (p = endaddr - 1; p >= startaddr; --p)
|
||
{
|
||
*p = val & 0xff;
|
||
val >>= 8;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
for (p = startaddr; p < endaddr; ++p)
|
||
{
|
||
*p = val & 0xff;
|
||
val >>= 8;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Store the address ADDR as a pointer of type TYPE at BUF, in target
|
||
form. */
|
||
void
|
||
store_typed_address (void *buf, struct type *type, CORE_ADDR addr)
|
||
{
|
||
if (TYPE_CODE (type) != TYPE_CODE_PTR
|
||
&& TYPE_CODE (type) != TYPE_CODE_REF)
|
||
internal_error (__FILE__, __LINE__,
|
||
"store_typed_address: "
|
||
"type is not a pointer or reference");
|
||
|
||
ADDRESS_TO_POINTER (type, buf, addr);
|
||
}
|
||
|
||
|
||
|
||
/* Return a `value' with the contents of (virtual or cooked) register
|
||
REGNUM as found in the specified FRAME. The register's type is
|
||
determined by register_type().
|
||
|
||
NOTE: returns NULL if register value is not available. Caller will
|
||
check return value or die! */
|
||
|
||
struct value *
|
||
value_of_register (int regnum, struct frame_info *frame)
|
||
{
|
||
CORE_ADDR addr;
|
||
int optim;
|
||
struct value *reg_val;
|
||
int realnum;
|
||
char raw_buffer[MAX_REGISTER_SIZE];
|
||
enum lval_type lval;
|
||
|
||
/* User registers lie completely outside of the range of normal
|
||
registers. Catch them early so that the target never sees them. */
|
||
if (regnum >= NUM_REGS + NUM_PSEUDO_REGS)
|
||
return value_of_user_reg (regnum, frame);
|
||
|
||
frame_register (frame, regnum, &optim, &lval, &addr, &realnum, raw_buffer);
|
||
|
||
/* FIXME: cagney/2002-05-15: This test is just bogus.
|
||
|
||
It indicates that the target failed to supply a value for a
|
||
register because it was "not available" at this time. Problem
|
||
is, the target still has the register and so get saved_register()
|
||
may be returning a value saved on the stack. */
|
||
|
||
if (register_cached (regnum) < 0)
|
||
return NULL; /* register value not available */
|
||
|
||
reg_val = allocate_value (register_type (current_gdbarch, regnum));
|
||
|
||
/* Convert raw data to virtual format if necessary. */
|
||
|
||
if (DEPRECATED_REGISTER_CONVERTIBLE_P ()
|
||
&& DEPRECATED_REGISTER_CONVERTIBLE (regnum))
|
||
{
|
||
DEPRECATED_REGISTER_CONVERT_TO_VIRTUAL (regnum, register_type (current_gdbarch, regnum),
|
||
raw_buffer, VALUE_CONTENTS_RAW (reg_val));
|
||
}
|
||
else if (DEPRECATED_REGISTER_RAW_SIZE (regnum) == DEPRECATED_REGISTER_VIRTUAL_SIZE (regnum))
|
||
memcpy (VALUE_CONTENTS_RAW (reg_val), raw_buffer,
|
||
DEPRECATED_REGISTER_RAW_SIZE (regnum));
|
||
else
|
||
internal_error (__FILE__, __LINE__,
|
||
"Register \"%s\" (%d) has conflicting raw (%d) and virtual (%d) size",
|
||
REGISTER_NAME (regnum),
|
||
regnum,
|
||
DEPRECATED_REGISTER_RAW_SIZE (regnum),
|
||
DEPRECATED_REGISTER_VIRTUAL_SIZE (regnum));
|
||
VALUE_LVAL (reg_val) = lval;
|
||
VALUE_ADDRESS (reg_val) = addr;
|
||
VALUE_REGNO (reg_val) = regnum;
|
||
VALUE_OPTIMIZED_OUT (reg_val) = optim;
|
||
return reg_val;
|
||
}
|
||
|
||
/* Given a pointer of type TYPE in target form in BUF, return the
|
||
address it represents. */
|
||
CORE_ADDR
|
||
unsigned_pointer_to_address (struct type *type, const void *buf)
|
||
{
|
||
return extract_unsigned_integer (buf, TYPE_LENGTH (type));
|
||
}
|
||
|
||
CORE_ADDR
|
||
signed_pointer_to_address (struct type *type, const void *buf)
|
||
{
|
||
return extract_signed_integer (buf, TYPE_LENGTH (type));
|
||
}
|
||
|
||
/* Given an address, store it as a pointer of type TYPE in target
|
||
format in BUF. */
|
||
void
|
||
unsigned_address_to_pointer (struct type *type, void *buf, CORE_ADDR addr)
|
||
{
|
||
store_unsigned_integer (buf, TYPE_LENGTH (type), addr);
|
||
}
|
||
|
||
void
|
||
address_to_signed_pointer (struct type *type, void *buf, CORE_ADDR addr)
|
||
{
|
||
store_signed_integer (buf, TYPE_LENGTH (type), addr);
|
||
}
|
||
|
||
/* Will calling read_var_value or locate_var_value on SYM end
|
||
up caring what frame it is being evaluated relative to? SYM must
|
||
be non-NULL. */
|
||
int
|
||
symbol_read_needs_frame (struct symbol *sym)
|
||
{
|
||
switch (SYMBOL_CLASS (sym))
|
||
{
|
||
/* All cases listed explicitly so that gcc -Wall will detect it if
|
||
we failed to consider one. */
|
||
case LOC_COMPUTED:
|
||
case LOC_COMPUTED_ARG:
|
||
/* FIXME: cagney/2004-01-26: It should be possible to
|
||
unconditionally call the SYMBOL_OPS method when available.
|
||
Unfortunately DWARF 2 stores the frame-base (instead of the
|
||
function) location in a function's symbol. Oops! For the
|
||
moment enable this when/where applicable. */
|
||
return SYMBOL_OPS (sym)->read_needs_frame (sym);
|
||
|
||
case LOC_REGISTER:
|
||
case LOC_ARG:
|
||
case LOC_REF_ARG:
|
||
case LOC_REGPARM:
|
||
case LOC_REGPARM_ADDR:
|
||
case LOC_LOCAL:
|
||
case LOC_LOCAL_ARG:
|
||
case LOC_BASEREG:
|
||
case LOC_BASEREG_ARG:
|
||
case LOC_HP_THREAD_LOCAL_STATIC:
|
||
return 1;
|
||
|
||
case LOC_UNDEF:
|
||
case LOC_CONST:
|
||
case LOC_STATIC:
|
||
case LOC_INDIRECT:
|
||
case LOC_TYPEDEF:
|
||
|
||
case LOC_LABEL:
|
||
/* Getting the address of a label can be done independently of the block,
|
||
even if some *uses* of that address wouldn't work so well without
|
||
the right frame. */
|
||
|
||
case LOC_BLOCK:
|
||
case LOC_CONST_BYTES:
|
||
case LOC_UNRESOLVED:
|
||
case LOC_OPTIMIZED_OUT:
|
||
return 0;
|
||
}
|
||
return 1;
|
||
}
|
||
|
||
/* Given a struct symbol for a variable,
|
||
and a stack frame id, read the value of the variable
|
||
and return a (pointer to a) struct value containing the value.
|
||
If the variable cannot be found, return a zero pointer.
|
||
If FRAME is NULL, use the deprecated_selected_frame. */
|
||
|
||
struct value *
|
||
read_var_value (struct symbol *var, struct frame_info *frame)
|
||
{
|
||
struct value *v;
|
||
struct type *type = SYMBOL_TYPE (var);
|
||
CORE_ADDR addr;
|
||
int len;
|
||
|
||
v = allocate_value (type);
|
||
VALUE_LVAL (v) = lval_memory; /* The most likely possibility. */
|
||
VALUE_BFD_SECTION (v) = SYMBOL_BFD_SECTION (var);
|
||
|
||
len = TYPE_LENGTH (type);
|
||
|
||
|
||
/* FIXME drow/2003-09-06: this call to the selected frame should be
|
||
pushed upwards to the callers. */
|
||
if (frame == NULL)
|
||
frame = deprecated_safe_get_selected_frame ();
|
||
|
||
switch (SYMBOL_CLASS (var))
|
||
{
|
||
case LOC_CONST:
|
||
/* Put the constant back in target format. */
|
||
store_signed_integer (VALUE_CONTENTS_RAW (v), len,
|
||
(LONGEST) SYMBOL_VALUE (var));
|
||
VALUE_LVAL (v) = not_lval;
|
||
return v;
|
||
|
||
case LOC_LABEL:
|
||
/* Put the constant back in target format. */
|
||
if (overlay_debugging)
|
||
{
|
||
CORE_ADDR addr
|
||
= symbol_overlayed_address (SYMBOL_VALUE_ADDRESS (var),
|
||
SYMBOL_BFD_SECTION (var));
|
||
store_typed_address (VALUE_CONTENTS_RAW (v), type, addr);
|
||
}
|
||
else
|
||
store_typed_address (VALUE_CONTENTS_RAW (v), type,
|
||
SYMBOL_VALUE_ADDRESS (var));
|
||
VALUE_LVAL (v) = not_lval;
|
||
return v;
|
||
|
||
case LOC_CONST_BYTES:
|
||
{
|
||
char *bytes_addr;
|
||
bytes_addr = SYMBOL_VALUE_BYTES (var);
|
||
memcpy (VALUE_CONTENTS_RAW (v), bytes_addr, len);
|
||
VALUE_LVAL (v) = not_lval;
|
||
return v;
|
||
}
|
||
|
||
case LOC_STATIC:
|
||
if (overlay_debugging)
|
||
addr = symbol_overlayed_address (SYMBOL_VALUE_ADDRESS (var),
|
||
SYMBOL_BFD_SECTION (var));
|
||
else
|
||
addr = SYMBOL_VALUE_ADDRESS (var);
|
||
break;
|
||
|
||
case LOC_INDIRECT:
|
||
{
|
||
/* The import slot does not have a real address in it from the
|
||
dynamic loader (dld.sl on HP-UX), if the target hasn't
|
||
begun execution yet, so check for that. */
|
||
CORE_ADDR locaddr;
|
||
struct value *loc;
|
||
if (!target_has_execution)
|
||
error ("\
|
||
Attempt to access variable defined in different shared object or load module when\n\
|
||
addresses have not been bound by the dynamic loader. Try again when executable is running.");
|
||
|
||
locaddr = SYMBOL_VALUE_ADDRESS (var);
|
||
loc = value_at (lookup_pointer_type (type), locaddr, NULL);
|
||
addr = value_as_address (loc);
|
||
}
|
||
|
||
case LOC_ARG:
|
||
if (frame == NULL)
|
||
return 0;
|
||
addr = get_frame_args_address (frame);
|
||
if (!addr)
|
||
return 0;
|
||
addr += SYMBOL_VALUE (var);
|
||
break;
|
||
|
||
case LOC_REF_ARG:
|
||
{
|
||
struct value *ref;
|
||
CORE_ADDR argref;
|
||
if (frame == NULL)
|
||
return 0;
|
||
argref = get_frame_args_address (frame);
|
||
if (!argref)
|
||
return 0;
|
||
argref += SYMBOL_VALUE (var);
|
||
ref = value_at (lookup_pointer_type (type), argref, NULL);
|
||
addr = value_as_address (ref);
|
||
break;
|
||
}
|
||
|
||
case LOC_LOCAL:
|
||
case LOC_LOCAL_ARG:
|
||
if (frame == NULL)
|
||
return 0;
|
||
addr = get_frame_locals_address (frame);
|
||
addr += SYMBOL_VALUE (var);
|
||
break;
|
||
|
||
case LOC_BASEREG:
|
||
case LOC_BASEREG_ARG:
|
||
case LOC_HP_THREAD_LOCAL_STATIC:
|
||
{
|
||
struct value *regval;
|
||
|
||
regval = value_from_register (lookup_pointer_type (type),
|
||
SYMBOL_BASEREG (var), frame);
|
||
if (regval == NULL)
|
||
error ("Value of base register not available.");
|
||
addr = value_as_address (regval);
|
||
addr += SYMBOL_VALUE (var);
|
||
break;
|
||
}
|
||
|
||
case LOC_TYPEDEF:
|
||
error ("Cannot look up value of a typedef");
|
||
break;
|
||
|
||
case LOC_BLOCK:
|
||
if (overlay_debugging)
|
||
VALUE_ADDRESS (v) = symbol_overlayed_address
|
||
(BLOCK_START (SYMBOL_BLOCK_VALUE (var)), SYMBOL_BFD_SECTION (var));
|
||
else
|
||
VALUE_ADDRESS (v) = BLOCK_START (SYMBOL_BLOCK_VALUE (var));
|
||
return v;
|
||
|
||
case LOC_REGISTER:
|
||
case LOC_REGPARM:
|
||
case LOC_REGPARM_ADDR:
|
||
{
|
||
struct block *b;
|
||
int regno = SYMBOL_VALUE (var);
|
||
struct value *regval;
|
||
|
||
if (frame == NULL)
|
||
return 0;
|
||
b = get_frame_block (frame, 0);
|
||
|
||
if (SYMBOL_CLASS (var) == LOC_REGPARM_ADDR)
|
||
{
|
||
regval = value_from_register (lookup_pointer_type (type),
|
||
regno,
|
||
frame);
|
||
|
||
if (regval == NULL)
|
||
error ("Value of register variable not available.");
|
||
|
||
addr = value_as_address (regval);
|
||
VALUE_LVAL (v) = lval_memory;
|
||
}
|
||
else
|
||
{
|
||
regval = value_from_register (type, regno, frame);
|
||
|
||
if (regval == NULL)
|
||
error ("Value of register variable not available.");
|
||
return regval;
|
||
}
|
||
}
|
||
break;
|
||
|
||
case LOC_COMPUTED:
|
||
case LOC_COMPUTED_ARG:
|
||
/* FIXME: cagney/2004-01-26: It should be possible to
|
||
unconditionally call the SYMBOL_OPS method when available.
|
||
Unfortunately DWARF 2 stores the frame-base (instead of the
|
||
function) location in a function's symbol. Oops! For the
|
||
moment enable this when/where applicable. */
|
||
if (frame == 0 && SYMBOL_OPS (var)->read_needs_frame (var))
|
||
return 0;
|
||
return SYMBOL_OPS (var)->read_variable (var, frame);
|
||
|
||
case LOC_UNRESOLVED:
|
||
{
|
||
struct minimal_symbol *msym;
|
||
|
||
msym = lookup_minimal_symbol (DEPRECATED_SYMBOL_NAME (var), NULL, NULL);
|
||
if (msym == NULL)
|
||
return 0;
|
||
if (overlay_debugging)
|
||
addr = symbol_overlayed_address (SYMBOL_VALUE_ADDRESS (msym),
|
||
SYMBOL_BFD_SECTION (msym));
|
||
else
|
||
addr = SYMBOL_VALUE_ADDRESS (msym);
|
||
}
|
||
break;
|
||
|
||
case LOC_OPTIMIZED_OUT:
|
||
VALUE_LVAL (v) = not_lval;
|
||
VALUE_OPTIMIZED_OUT (v) = 1;
|
||
return v;
|
||
|
||
default:
|
||
error ("Cannot look up value of a botched symbol.");
|
||
break;
|
||
}
|
||
|
||
VALUE_ADDRESS (v) = addr;
|
||
VALUE_LAZY (v) = 1;
|
||
return v;
|
||
}
|
||
|
||
/* Return a value of type TYPE, stored in register REGNUM, in frame
|
||
FRAME.
|
||
|
||
NOTE: returns NULL if register value is not available.
|
||
Caller will check return value or die! */
|
||
|
||
struct value *
|
||
value_from_register (struct type *type, int regnum, struct frame_info *frame)
|
||
{
|
||
struct gdbarch *gdbarch = get_frame_arch (frame);
|
||
struct value *v = allocate_value (type);
|
||
CHECK_TYPEDEF (type);
|
||
|
||
if (TYPE_LENGTH (type) == 0)
|
||
{
|
||
/* It doesn't matter much what we return for this: since the
|
||
length is zero, it could be anything. But if allowed to see
|
||
a zero-length type, the register-finding loop below will set
|
||
neither mem_stor nor reg_stor, and then report an internal
|
||
error.
|
||
|
||
Zero-length types can legitimately arise from declarations
|
||
like 'struct {}'. GDB may also create them when it finds
|
||
bogus debugging information; for example, in GCC 2.95.4 and
|
||
binutils 2.11.93.0.2, the STABS BINCL->EXCL compression
|
||
process can create bad type numbers. GDB reads these as
|
||
TYPE_CODE_UNDEF types, with zero length. (That bug is
|
||
actually the only known way to get a zero-length value
|
||
allocated to a register --- which is what it takes to make it
|
||
here.)
|
||
|
||
We'll just attribute the value to the original register. */
|
||
VALUE_LVAL (v) = lval_register;
|
||
VALUE_ADDRESS (v) = regnum;
|
||
VALUE_REGNO (v) = regnum;
|
||
}
|
||
else if (CONVERT_REGISTER_P (regnum, type))
|
||
{
|
||
/* The ISA/ABI need to something weird when obtaining the
|
||
specified value from this register. It might need to
|
||
re-order non-adjacent, starting with REGNUM (see MIPS and
|
||
i386). It might need to convert the [float] register into
|
||
the corresponding [integer] type (see Alpha). The assumption
|
||
is that REGISTER_TO_VALUE populates the entire value
|
||
including the location. */
|
||
REGISTER_TO_VALUE (frame, regnum, type, VALUE_CONTENTS_RAW (v));
|
||
VALUE_LVAL (v) = lval_reg_frame_relative;
|
||
VALUE_FRAME_ID (v) = get_frame_id (frame);
|
||
VALUE_FRAME_REGNUM (v) = regnum;
|
||
}
|
||
else
|
||
{
|
||
int local_regnum;
|
||
int mem_stor = 0, reg_stor = 0;
|
||
int mem_tracking = 1;
|
||
CORE_ADDR last_addr = 0;
|
||
CORE_ADDR first_addr = 0;
|
||
int first_realnum = regnum;
|
||
int len = TYPE_LENGTH (type);
|
||
int value_bytes_copied;
|
||
int optimized = 0;
|
||
char *value_bytes = (char *) alloca (len + MAX_REGISTER_SIZE);
|
||
|
||
/* Copy all of the data out, whereever it may be. */
|
||
for (local_regnum = regnum, value_bytes_copied = 0;
|
||
value_bytes_copied < len;
|
||
(value_bytes_copied += DEPRECATED_REGISTER_RAW_SIZE (local_regnum),
|
||
++local_regnum))
|
||
{
|
||
int realnum;
|
||
int optim;
|
||
enum lval_type lval;
|
||
CORE_ADDR addr;
|
||
frame_register (frame, local_regnum, &optim, &lval, &addr,
|
||
&realnum, value_bytes + value_bytes_copied);
|
||
optimized += optim;
|
||
if (register_cached (local_regnum) == -1)
|
||
return NULL; /* register value not available */
|
||
|
||
if (regnum == local_regnum)
|
||
{
|
||
first_addr = addr;
|
||
first_realnum = realnum;
|
||
}
|
||
if (lval == lval_register)
|
||
reg_stor++;
|
||
else
|
||
{
|
||
mem_stor++;
|
||
|
||
mem_tracking = (mem_tracking
|
||
&& (regnum == local_regnum
|
||
|| addr == last_addr));
|
||
}
|
||
last_addr = addr;
|
||
}
|
||
|
||
/* FIXME: cagney/2003-06-04: Shouldn't this always use
|
||
lval_reg_frame_relative? If it doesn't and the register's
|
||
location changes (say after a resume) then this value is
|
||
going to have wrong information. */
|
||
if ((reg_stor && mem_stor)
|
||
|| (mem_stor && !mem_tracking))
|
||
/* Mixed storage; all of the hassle we just went through was
|
||
for some good purpose. */
|
||
{
|
||
VALUE_LVAL (v) = lval_reg_frame_relative;
|
||
VALUE_FRAME_ID (v) = get_frame_id (frame);
|
||
VALUE_FRAME_REGNUM (v) = regnum;
|
||
}
|
||
else if (mem_stor)
|
||
{
|
||
VALUE_LVAL (v) = lval_memory;
|
||
VALUE_ADDRESS (v) = first_addr;
|
||
}
|
||
else if (reg_stor)
|
||
{
|
||
VALUE_LVAL (v) = lval_register;
|
||
VALUE_ADDRESS (v) = first_addr;
|
||
VALUE_REGNO (v) = first_realnum;
|
||
}
|
||
else
|
||
internal_error (__FILE__, __LINE__,
|
||
"value_from_register: Value not stored anywhere!");
|
||
|
||
VALUE_OPTIMIZED_OUT (v) = optimized;
|
||
|
||
/* Any structure stored in more than one register will always be
|
||
an integral number of registers. Otherwise, you need to do
|
||
some fiddling with the last register copied here for little
|
||
endian machines. */
|
||
if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG
|
||
&& len < DEPRECATED_REGISTER_RAW_SIZE (regnum))
|
||
/* Big-endian, and we want less than full size. */
|
||
VALUE_OFFSET (v) = DEPRECATED_REGISTER_RAW_SIZE (regnum) - len;
|
||
else
|
||
VALUE_OFFSET (v) = 0;
|
||
memcpy (VALUE_CONTENTS_RAW (v), value_bytes + VALUE_OFFSET (v), len);
|
||
}
|
||
return v;
|
||
}
|
||
|
||
|
||
/* Given a struct symbol for a variable or function,
|
||
and a stack frame id,
|
||
return a (pointer to a) struct value containing the properly typed
|
||
address. */
|
||
|
||
struct value *
|
||
locate_var_value (struct symbol *var, struct frame_info *frame)
|
||
{
|
||
CORE_ADDR addr = 0;
|
||
struct type *type = SYMBOL_TYPE (var);
|
||
struct value *lazy_value;
|
||
|
||
/* Evaluate it first; if the result is a memory address, we're fine.
|
||
Lazy evaluation pays off here. */
|
||
|
||
lazy_value = read_var_value (var, frame);
|
||
if (lazy_value == 0)
|
||
error ("Address of \"%s\" is unknown.", SYMBOL_PRINT_NAME (var));
|
||
|
||
if (VALUE_LAZY (lazy_value)
|
||
|| TYPE_CODE (type) == TYPE_CODE_FUNC)
|
||
{
|
||
struct value *val;
|
||
|
||
addr = VALUE_ADDRESS (lazy_value);
|
||
val = value_from_pointer (lookup_pointer_type (type), addr);
|
||
VALUE_BFD_SECTION (val) = VALUE_BFD_SECTION (lazy_value);
|
||
return val;
|
||
}
|
||
|
||
/* Not a memory address; check what the problem was. */
|
||
switch (VALUE_LVAL (lazy_value))
|
||
{
|
||
case lval_register:
|
||
gdb_assert (REGISTER_NAME (VALUE_REGNO (lazy_value)) != NULL
|
||
&& *REGISTER_NAME (VALUE_REGNO (lazy_value)) != '\0');
|
||
error("Address requested for identifier "
|
||
"\"%s\" which is in register $%s",
|
||
SYMBOL_PRINT_NAME (var),
|
||
REGISTER_NAME (VALUE_REGNO (lazy_value)));
|
||
break;
|
||
|
||
case lval_reg_frame_relative:
|
||
gdb_assert (REGISTER_NAME (VALUE_FRAME_REGNUM (lazy_value)) != NULL
|
||
&& *REGISTER_NAME (VALUE_FRAME_REGNUM (lazy_value)) != '\0');
|
||
error("Address requested for identifier "
|
||
"\"%s\" which is in frame register $%s",
|
||
SYMBOL_PRINT_NAME (var),
|
||
REGISTER_NAME (VALUE_FRAME_REGNUM (lazy_value)));
|
||
break;
|
||
|
||
default:
|
||
error ("Can't take address of \"%s\" which isn't an lvalue.",
|
||
SYMBOL_PRINT_NAME (var));
|
||
break;
|
||
}
|
||
return 0; /* For lint -- never reached */
|
||
}
|