/* 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, 2005 Free
- Software Foundation, Inc.
+ Copyright (C) 1986-2015 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
+ 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,
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 "symtab.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"
+#include "objfiles.h"
+#include "language.h"
+#include "dwarf2loc.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. */
+/* Basic byte-swapping routines. All 'extract' functions return a
+ host-format integer from 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
#endif
LONGEST
-extract_signed_integer (const void *addr, int len)
+extract_signed_integer (const gdb_byte *addr, int len,
+ enum bfd_endian byte_order)
{
LONGEST retval;
const unsigned char *p;
const unsigned char *endaddr = startaddr + len;
if (len > (int) sizeof (LONGEST))
- error ("\
-That operation is not available on integers of more than %d bytes.",
+ 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)
+ if (byte_order == BFD_ENDIAN_BIG)
{
p = startaddr;
/* Do the sign extension once at the start. */
}
ULONGEST
-extract_unsigned_integer (const void *addr, int len)
+extract_unsigned_integer (const gdb_byte *addr, int len,
+ enum bfd_endian byte_order)
{
ULONGEST retval;
const unsigned char *p;
const unsigned char *endaddr = startaddr + len;
if (len > (int) sizeof (ULONGEST))
- error ("\
-That operation is not available on integers of more than %d bytes.",
+ 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)
+ if (byte_order == BFD_ENDIAN_BIG)
{
for (p = startaddr; p < endaddr; ++p)
retval = (retval << 8) | *p;
function returns 1 and sets *PVAL. Otherwise it returns 0. */
int
-extract_long_unsigned_integer (const void *addr, int orig_len, LONGEST *pval)
+extract_long_unsigned_integer (const gdb_byte *addr, int orig_len,
+ enum bfd_endian byte_order, LONGEST *pval)
{
- char *p, *first_addr;
+ const gdb_byte *p;
+ const gdb_byte *first_addr;
int len;
len = orig_len;
- if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG)
+ if (byte_order == BFD_ENDIAN_BIG)
{
- for (p = (char *) addr;
- len > (int) sizeof (LONGEST) && p < (char *) addr + orig_len;
+ for (p = addr;
+ len > (int) sizeof (LONGEST) && p < addr + orig_len;
p++)
{
if (*p == 0)
}
else
{
- first_addr = (char *) addr;
- for (p = (char *) addr + orig_len - 1;
- len > (int) sizeof (LONGEST) && p >= (char *) addr;
+ first_addr = addr;
+ for (p = addr + orig_len - 1;
+ len > (int) sizeof (LONGEST) && p >= addr;
p--)
{
if (*p == 0)
if (len <= (int) sizeof (LONGEST))
{
*pval = (LONGEST) extract_unsigned_integer (first_addr,
- sizeof (LONGEST));
+ sizeof (LONGEST),
+ byte_order);
return 1;
}
/* 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)
+extract_typed_address (const gdb_byte *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");
+ _("extract_typed_address: "
+ "type is not a pointer or reference"));
- return POINTER_TO_ADDRESS (type, buf);
+ return gdbarch_pointer_to_address (get_type_arch (type), type, buf);
}
+/* All 'store' functions accept a host-format integer and store a
+ target-format integer at ADDR which is LEN bytes long. */
void
-store_signed_integer (void *addr, int len, LONGEST val)
+store_signed_integer (gdb_byte *addr, int len,
+ enum bfd_endian byte_order, LONGEST val)
{
- unsigned char *p;
- unsigned char *startaddr = (unsigned char *) addr;
- unsigned char *endaddr = startaddr + len;
+ gdb_byte *p;
+ gdb_byte *startaddr = addr;
+ gdb_byte *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)
+ if (byte_order == BFD_ENDIAN_BIG)
{
for (p = endaddr - 1; p >= startaddr; --p)
{
}
void
-store_unsigned_integer (void *addr, int len, ULONGEST val)
+store_unsigned_integer (gdb_byte *addr, int len,
+ enum bfd_endian byte_order, ULONGEST val)
{
unsigned char *p;
unsigned char *startaddr = (unsigned char *) addr;
/* Start at the least significant end of the integer, and work towards
the most significant. */
- if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG)
+ if (byte_order == BFD_ENDIAN_BIG)
{
for (p = endaddr - 1; p >= startaddr; --p)
{
/* 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)
+store_typed_address (gdb_byte *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");
+ _("store_typed_address: "
+ "type is not a pointer or reference"));
- ADDRESS_TO_POINTER (type, buf, addr);
+ gdbarch_address_to_pointer (get_type_arch (type), 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! */
+ determined by register_type(). */
struct value *
value_of_register (int regnum, struct frame_info *frame)
{
- CORE_ADDR addr;
- int optim;
+ struct gdbarch *gdbarch = get_frame_arch (frame);
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)
+ if (regnum >= gdbarch_num_regs (gdbarch)
+ + gdbarch_num_pseudo_regs (gdbarch))
return value_of_user_reg (regnum, frame);
- frame_register (frame, regnum, &optim, &lval, &addr, &realnum, raw_buffer);
+ reg_val = value_of_register_lazy (frame, regnum);
+ value_fetch_lazy (reg_val);
+ return reg_val;
+}
- /* FIXME: cagney/2002-05-15: This test is just bogus.
+/* 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(). The value is not fetched. */
- 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. */
+struct value *
+value_of_register_lazy (struct frame_info *frame, int regnum)
+{
+ struct gdbarch *gdbarch = get_frame_arch (frame);
+ struct value *reg_val;
- if (register_cached (regnum) < 0)
- return NULL; /* register value not available */
+ gdb_assert (regnum < (gdbarch_num_regs (gdbarch)
+ + gdbarch_num_pseudo_regs (gdbarch)));
- reg_val = allocate_value (register_type (current_gdbarch, regnum));
+ /* We should have a valid (i.e. non-sentinel) frame. */
+ gdb_assert (frame_id_p (get_frame_id (frame)));
- memcpy (value_contents_raw (reg_val), raw_buffer,
- register_size (current_gdbarch, regnum));
- VALUE_LVAL (reg_val) = lval;
- VALUE_ADDRESS (reg_val) = addr;
+ reg_val = allocate_value_lazy (register_type (gdbarch, regnum));
+ VALUE_LVAL (reg_val) = lval_register;
VALUE_REGNUM (reg_val) = regnum;
- set_value_optimized_out (reg_val, optim);
VALUE_FRAME_ID (reg_val) = get_frame_id (frame);
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)
+unsigned_pointer_to_address (struct gdbarch *gdbarch,
+ struct type *type, const gdb_byte *buf)
{
- return extract_unsigned_integer (buf, TYPE_LENGTH (type));
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+
+ return extract_unsigned_integer (buf, TYPE_LENGTH (type), byte_order);
}
CORE_ADDR
-signed_pointer_to_address (struct type *type, const void *buf)
+signed_pointer_to_address (struct gdbarch *gdbarch,
+ struct type *type, const gdb_byte *buf)
{
- return extract_signed_integer (buf, TYPE_LENGTH (type));
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+
+ return extract_signed_integer (buf, TYPE_LENGTH (type), byte_order);
}
/* 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)
+unsigned_address_to_pointer (struct gdbarch *gdbarch, struct type *type,
+ gdb_byte *buf, CORE_ADDR addr)
{
- store_unsigned_integer (buf, TYPE_LENGTH (type), addr);
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+
+ store_unsigned_integer (buf, TYPE_LENGTH (type), byte_order, addr);
}
void
-address_to_signed_pointer (struct type *type, void *buf, CORE_ADDR addr)
+address_to_signed_pointer (struct gdbarch *gdbarch, struct type *type,
+ gdb_byte *buf, CORE_ADDR addr)
{
- store_signed_integer (buf, TYPE_LENGTH (type), addr);
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+
+ store_signed_integer (buf, TYPE_LENGTH (type), byte_order, addr);
}
\f
/* Will calling read_var_value or locate_var_value on SYM end
int
symbol_read_needs_frame (struct symbol *sym)
{
+ if (SYMBOL_COMPUTED_OPS (sym) != NULL)
+ return SYMBOL_COMPUTED_OPS (sym)->read_needs_frame (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);
+ gdb_assert_not_reached (_("LOC_COMPUTED variable missing a method"));
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:
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. */
+/* Private data to be used with minsym_lookup_iterator_cb. */
+
+struct minsym_lookup_data
+{
+ /* The name of the minimal symbol we are searching for. */
+ const char *name;
+
+ /* The field where the callback should store the minimal symbol
+ if found. It should be initialized to NULL before the search
+ is started. */
+ struct bound_minimal_symbol result;
+};
+
+/* A callback function for gdbarch_iterate_over_objfiles_in_search_order.
+ It searches by name for a minimal symbol within the given OBJFILE.
+ The arguments are passed via CB_DATA, which in reality is a pointer
+ to struct minsym_lookup_data. */
+
+static int
+minsym_lookup_iterator_cb (struct objfile *objfile, void *cb_data)
+{
+ struct minsym_lookup_data *data = (struct minsym_lookup_data *) cb_data;
+
+ gdb_assert (data->result.minsym == NULL);
+
+ data->result = lookup_minimal_symbol (data->name, NULL, objfile);
+
+ /* The iterator should stop iff a match was found. */
+ return (data->result.minsym != NULL);
+}
+
+/* Given static link expression and the frame it lives in, look for the frame
+ the static links points to and return it. Return NULL if we could not find
+ such a frame. */
+
+static struct frame_info *
+follow_static_link (struct frame_info *frame,
+ const struct dynamic_prop *static_link)
+{
+ CORE_ADDR upper_frame_base;
+
+ if (!dwarf2_evaluate_property (static_link, frame, NULL, &upper_frame_base))
+ return NULL;
+
+ /* Now climb up the stack frame until we reach the frame we are interested
+ in. */
+ for (; frame != NULL; frame = get_prev_frame (frame))
+ {
+ struct symbol *framefunc = get_frame_function (frame);
+
+ /* Stacks can be quite deep: give the user a chance to stop this. */
+ QUIT;
+
+ /* If we don't know how to compute FRAME's base address, don't give up:
+ maybe the frame we are looking for is upper in the stace frame. */
+ if (framefunc != NULL
+ && SYMBOL_BLOCK_OPS (framefunc)->get_frame_base != NULL
+ && (SYMBOL_BLOCK_OPS (framefunc)->get_frame_base (framefunc, frame)
+ == upper_frame_base))
+ break;
+ }
+
+ return frame;
+}
+
+/* Assuming VAR is a symbol that can be reached from FRAME thanks to lexical
+ rules, look for the frame that is actually hosting VAR and return it. If,
+ for some reason, we found no such frame, return NULL.
+
+ This kind of computation is necessary to correctly handle lexically nested
+ functions.
+
+ Note that in some cases, we know what scope VAR comes from but we cannot
+ reach the specific frame that hosts the instance of VAR we are looking for.
+ For backward compatibility purposes (with old compilers), we then look for
+ the first frame that can host it. */
+
+static struct frame_info *
+get_hosting_frame (struct symbol *var, const struct block *var_block,
+ struct frame_info *frame)
+{
+ const struct block *frame_block = NULL;
+
+ if (!symbol_read_needs_frame (var))
+ return NULL;
+
+ /* Some symbols for local variables have no block: this happens when they are
+ not produced by a debug information reader, for instance when GDB creates
+ synthetic symbols. Without block information, we must assume they are
+ local to FRAME. In this case, there is nothing to do. */
+ else if (var_block == NULL)
+ return frame;
+
+ /* We currently assume that all symbols with a location list need a frame.
+ This is true in practice because selecting the location description
+ requires to compute the CFA, hence requires a frame. However we have
+ tests that embed global/static symbols with null location lists.
+ We want to get <optimized out> instead of <frame required> when evaluating
+ them so return a frame instead of raising an error. */
+ else if (var_block == block_global_block (var_block)
+ || var_block == block_static_block (var_block))
+ return frame;
+
+ /* We have to handle the "my_func::my_local_var" notation. This requires us
+ to look for upper frames when we find no block for the current frame: here
+ and below, handle when frame_block == NULL. */
+ if (frame != NULL)
+ frame_block = get_frame_block (frame, NULL);
+
+ /* Climb up the call stack until reaching the frame we are looking for. */
+ while (frame != NULL && frame_block != var_block)
+ {
+ /* Stacks can be quite deep: give the user a chance to stop this. */
+ QUIT;
+
+ if (frame_block == NULL)
+ {
+ frame = get_prev_frame (frame);
+ if (frame == NULL)
+ break;
+ frame_block = get_frame_block (frame, NULL);
+ }
+
+ /* If we failed to find the proper frame, fallback to the heuristic
+ method below. */
+ else if (frame_block == block_global_block (frame_block))
+ {
+ frame = NULL;
+ break;
+ }
+
+ /* Assuming we have a block for this frame: if we are at the function
+ level, the immediate upper lexical block is in an outer function:
+ follow the static link. */
+ else if (BLOCK_FUNCTION (frame_block))
+ {
+ const struct dynamic_prop *static_link
+ = block_static_link (frame_block);
+ int could_climb_up = 0;
+
+ if (static_link != NULL)
+ {
+ frame = follow_static_link (frame, static_link);
+ if (frame != NULL)
+ {
+ frame_block = get_frame_block (frame, NULL);
+ could_climb_up = frame_block != NULL;
+ }
+ }
+ if (!could_climb_up)
+ {
+ frame = NULL;
+ break;
+ }
+ }
+
+ else
+ /* We must be in some function nested lexical block. Just get the
+ outer block: both must share the same frame. */
+ frame_block = BLOCK_SUPERBLOCK (frame_block);
+ }
+
+ /* Old compilers may not provide a static link, or they may provide an
+ invalid one. For such cases, fallback on the old way to evaluate
+ non-local references: just climb up the call stack and pick the first
+ frame that contains the variable we are looking for. */
+ if (frame == NULL)
+ {
+ frame = block_innermost_frame (var_block);
+ if (frame == NULL)
+ {
+ if (BLOCK_FUNCTION (var_block)
+ && !block_inlined_p (var_block)
+ && SYMBOL_PRINT_NAME (BLOCK_FUNCTION (var_block)))
+ error (_("No frame is currently executing in block %s."),
+ SYMBOL_PRINT_NAME (BLOCK_FUNCTION (var_block)));
+ else
+ error (_("No frame is currently executing in specified"
+ " block"));
+ }
+ }
+
+ return frame;
+}
+
+/* A default implementation for the "la_read_var_value" hook in
+ the language vector which should work in most situations. */
struct value *
-read_var_value (struct symbol *var, struct frame_info *frame)
+default_read_var_value (struct symbol *var, const struct block *var_block,
+ 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. */
+ /* Call check_typedef on our type to make sure that, if TYPE is
+ a TYPE_CODE_TYPEDEF, its length is set to the length of the target type
+ instead of zero. However, we do not replace the typedef type by the
+ target type, because we want to keep the typedef in order to be able to
+ set the returned value type description correctly. */
+ check_typedef (type);
- len = TYPE_LENGTH (type);
+ if (symbol_read_needs_frame (var))
+ gdb_assert (frame != NULL);
+ if (frame != NULL)
+ frame = get_hosting_frame (var, var_block, frame);
- /* 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 ();
+ if (SYMBOL_COMPUTED_OPS (var) != NULL)
+ return SYMBOL_COMPUTED_OPS (var)->read_variable (var, frame);
switch (SYMBOL_CLASS (var))
{
case LOC_CONST:
- /* Put the constant back in target format. */
- store_signed_integer (value_contents_raw (v), len,
+ if (is_dynamic_type (type))
+ {
+ /* Value is a constant byte-sequence and needs no memory access. */
+ type = resolve_dynamic_type (type, NULL, /* Unused address. */ 0);
+ }
+ /* Put the constant back in target format. */
+ v = allocate_value (type);
+ store_signed_integer (value_contents_raw (v), TYPE_LENGTH (type),
+ gdbarch_byte_order (get_type_arch (type)),
(LONGEST) SYMBOL_VALUE (var));
VALUE_LVAL (v) = not_lval;
return v;
case LOC_LABEL:
/* Put the constant back in target format. */
+ v = allocate_value (type);
if (overlay_debugging)
{
CORE_ADDR addr
= symbol_overlayed_address (SYMBOL_VALUE_ADDRESS (var),
- SYMBOL_BFD_SECTION (var));
+ SYMBOL_OBJ_SECTION (symbol_objfile (var),
+ var));
+
store_typed_address (value_contents_raw (v), type, addr);
}
else
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;
- }
+ if (is_dynamic_type (type))
+ {
+ /* Value is a constant byte-sequence and needs no memory access. */
+ type = resolve_dynamic_type (type, NULL, /* Unused address. */ 0);
+ }
+ v = allocate_value (type);
+ memcpy (value_contents_raw (v), SYMBOL_VALUE_BYTES (var),
+ TYPE_LENGTH (type));
+ 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));
+ SYMBOL_OBJ_SECTION (symbol_objfile (var),
+ 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);
- addr = value_as_address (loc);
- }
-
case LOC_ARG:
- if (frame == NULL)
- return 0;
addr = get_frame_args_address (frame);
if (!addr)
- return 0;
+ error (_("Unknown argument list address for `%s'."),
+ SYMBOL_PRINT_NAME (var));
addr += SYMBOL_VALUE (var);
break;
{
struct value *ref;
CORE_ADDR argref;
- if (frame == NULL)
- return 0;
+
argref = get_frame_args_address (frame);
if (!argref)
- return 0;
+ error (_("Unknown argument list address for `%s'."),
+ SYMBOL_PRINT_NAME (var));
argref += SYMBOL_VALUE (var);
ref = value_at (lookup_pointer_type (type), argref);
addr = value_as_address (ref);
}
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");
+ error (_("Cannot look up value of a typedef `%s'."),
+ SYMBOL_PRINT_NAME (var));
break;
case LOC_BLOCK:
if (overlay_debugging)
- VALUE_ADDRESS (v) = symbol_overlayed_address
- (BLOCK_START (SYMBOL_BLOCK_VALUE (var)), SYMBOL_BFD_SECTION (var));
+ addr = symbol_overlayed_address
+ (BLOCK_START (SYMBOL_BLOCK_VALUE (var)),
+ SYMBOL_OBJ_SECTION (symbol_objfile (var), var));
else
- VALUE_ADDRESS (v) = BLOCK_START (SYMBOL_BLOCK_VALUE (var));
- return v;
+ addr = BLOCK_START (SYMBOL_BLOCK_VALUE (var));
+ break;
case LOC_REGISTER:
- case LOC_REGPARM:
case LOC_REGPARM_ADDR:
{
- struct block *b;
- int regno = SYMBOL_VALUE (var);
+ int regno = SYMBOL_REGISTER_OPS (var)
+ ->register_number (var, get_frame_arch (frame));
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),
frame);
if (regval == NULL)
- error ("Value of register variable not available.");
+ error (_("Value of register variable not available for `%s'."),
+ SYMBOL_PRINT_NAME (var));
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.");
+ error (_("Value of register variable not available for `%s'."),
+ SYMBOL_PRINT_NAME (var));
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);
+ gdb_assert_not_reached (_("LOC_COMPUTED variable missing a method"));
case LOC_UNRESOLVED:
{
+ struct minsym_lookup_data lookup_data;
struct minimal_symbol *msym;
+ struct obj_section *obj_section;
+
+ memset (&lookup_data, 0, sizeof (lookup_data));
+ lookup_data.name = SYMBOL_LINKAGE_NAME (var);
+
+ gdbarch_iterate_over_objfiles_in_search_order
+ (symbol_arch (var),
+ minsym_lookup_iterator_cb, &lookup_data,
+ symbol_objfile (var));
+ msym = lookup_data.result.minsym;
- msym = lookup_minimal_symbol (DEPRECATED_SYMBOL_NAME (var), NULL, NULL);
if (msym == NULL)
- return 0;
+ error (_("No global symbol \"%s\"."), SYMBOL_LINKAGE_NAME (var));
if (overlay_debugging)
- addr = symbol_overlayed_address (SYMBOL_VALUE_ADDRESS (msym),
- SYMBOL_BFD_SECTION (msym));
+ addr = symbol_overlayed_address (BMSYMBOL_VALUE_ADDRESS (lookup_data.result),
+ MSYMBOL_OBJ_SECTION (lookup_data.result.objfile,
+ msym));
else
- addr = SYMBOL_VALUE_ADDRESS (msym);
+ addr = BMSYMBOL_VALUE_ADDRESS (lookup_data.result);
+
+ obj_section = MSYMBOL_OBJ_SECTION (lookup_data.result.objfile, msym);
+ if (obj_section
+ && (obj_section->the_bfd_section->flags & SEC_THREAD_LOCAL) != 0)
+ addr = target_translate_tls_address (obj_section->objfile, addr);
}
break;
case LOC_OPTIMIZED_OUT:
- VALUE_LVAL (v) = not_lval;
- set_value_optimized_out (v, 1);
- return v;
+ return allocate_optimized_out_value (type);
default:
- error ("Cannot look up value of a botched symbol.");
+ error (_("Cannot look up value of a botched symbol `%s'."),
+ SYMBOL_PRINT_NAME (var));
break;
}
- VALUE_ADDRESS (v) = addr;
- set_value_lazy (v, 1);
+ v = value_at_lazy (type, addr);
return v;
}
-/* Return a value of type TYPE, stored in register REGNUM, in frame
- FRAME.
+/* Calls VAR's language la_read_var_value hook with the given arguments. */
+
+struct value *
+read_var_value (struct symbol *var, const struct block *var_block,
+ struct frame_info *frame)
+{
+ const struct language_defn *lang = language_def (SYMBOL_LANGUAGE (var));
+
+ gdb_assert (lang != NULL);
+ gdb_assert (lang->la_read_var_value != NULL);
- NOTE: returns NULL if register value is not available.
- Caller will check return value or die! */
+ return lang->la_read_var_value (var, var_block, frame);
+}
+
+/* Install default attributes for register values. */
struct value *
-value_from_register (struct type *type, int regnum, struct frame_info *frame)
+default_value_from_register (struct gdbarch *gdbarch, struct type *type,
+ int regnum, struct frame_id frame_id)
+{
+ int len = TYPE_LENGTH (type);
+ struct value *value = allocate_value (type);
+
+ VALUE_LVAL (value) = lval_register;
+ VALUE_FRAME_ID (value) = frame_id;
+ VALUE_REGNUM (value) = regnum;
+
+ /* 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 (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG
+ && len < register_size (gdbarch, regnum))
+ /* Big-endian, and we want less than full size. */
+ set_value_offset (value, register_size (gdbarch, regnum) - len);
+ else
+ set_value_offset (value, 0);
+
+ return value;
+}
+
+/* VALUE must be an lval_register value. If regnum is the value's
+ associated register number, and len the length of the values type,
+ read one or more registers in FRAME, starting with register REGNUM,
+ until we've read LEN bytes.
+
+ If any of the registers we try to read are optimized out, then mark the
+ complete resulting value as optimized out. */
+
+void
+read_frame_register_value (struct value *value, struct frame_info *frame)
{
struct gdbarch *gdbarch = get_frame_arch (frame);
- struct value *v = allocate_value (type);
- CHECK_TYPEDEF (type);
+ int offset = 0;
+ int reg_offset = value_offset (value);
+ int regnum = VALUE_REGNUM (value);
+ int len = type_length_units (check_typedef (value_type (value)));
- if (TYPE_LENGTH (type) == 0)
+ gdb_assert (VALUE_LVAL (value) == lval_register);
+
+ /* Skip registers wholly inside of REG_OFFSET. */
+ while (reg_offset >= register_size (gdbarch, regnum))
{
- /* 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 {}' (a GCC extension, not valid ISO C). 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_REGNUM (v) = regnum;
+ reg_offset -= register_size (gdbarch, regnum);
+ regnum++;
}
- else if (CONVERT_REGISTER_P (regnum, type))
+
+ /* Copy the data. */
+ while (len > 0)
+ {
+ struct value *regval = get_frame_register_value (frame, regnum);
+ int reg_len = type_length_units (value_type (regval)) - reg_offset;
+
+ /* If the register length is larger than the number of bytes
+ remaining to copy, then only copy the appropriate bytes. */
+ if (reg_len > len)
+ reg_len = len;
+
+ value_contents_copy (value, offset, regval, reg_offset, reg_len);
+
+ offset += reg_len;
+ len -= reg_len;
+ reg_offset = 0;
+ regnum++;
+ }
+}
+
+/* Return a value of type TYPE, stored in register REGNUM, in frame FRAME. */
+
+struct value *
+value_from_register (struct type *type, int regnum, struct frame_info *frame)
+{
+ struct gdbarch *gdbarch = get_frame_arch (frame);
+ struct type *type1 = check_typedef (type);
+ struct value *v;
+
+ if (gdbarch_convert_register_p (gdbarch, regnum, type1))
{
+ int optim, unavail, ok;
+
/* 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
+ is that gdbarch_register_to_value populates the entire value
including the location. */
- REGISTER_TO_VALUE (frame, regnum, type, value_contents_raw (v));
+ v = allocate_value (type);
VALUE_LVAL (v) = lval_register;
VALUE_FRAME_ID (v) = get_frame_id (frame);
VALUE_REGNUM (v) = regnum;
+ ok = gdbarch_register_to_value (gdbarch, frame, regnum, type1,
+ value_contents_raw (v), &optim,
+ &unavail);
+
+ if (!ok)
+ {
+ if (optim)
+ mark_value_bytes_optimized_out (v, 0, TYPE_LENGTH (type));
+ if (unavail)
+ mark_value_bytes_unavailable (v, 0, TYPE_LENGTH (type));
+ }
}
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 += register_size (current_gdbarch, 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++;
-
- /* FIXME: cagney/2004-11-12: I think this is trying to
- check that the stored registers are adjacent in
- memory. It isn't doing a good job? */
- mem_tracking = (mem_tracking
- && (regnum == local_regnum
- || addr == last_addr));
- }
- last_addr = addr;
- }
-
- if (mem_tracking && mem_stor && !reg_stor)
- {
- VALUE_LVAL (v) = lval_memory;
- VALUE_ADDRESS (v) = first_addr;
- }
- else
- {
- VALUE_LVAL (v) = lval_register;
- VALUE_FRAME_ID (v) = get_frame_id (frame);
- VALUE_REGNUM (v) = regnum;
- }
-
- set_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 < register_size (current_gdbarch, regnum))
- /* Big-endian, and we want less than full size. */
- v->offset = register_size (current_gdbarch, regnum) - len;
- else
- v->offset = 0;
- memcpy (value_contents_raw (v), value_bytes + value_offset (v), len);
+ /* Construct the value. */
+ v = gdbarch_value_from_register (gdbarch, type,
+ regnum, get_frame_id (frame));
+
+ /* Get the data. */
+ read_frame_register_value (v, frame);
}
+
return v;
}
-\f
-/* 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. */
+/* Return contents of register REGNUM in frame FRAME as address.
+ Will abort if register value is not available. */
-struct value *
-locate_var_value (struct symbol *var, struct frame_info *frame)
+CORE_ADDR
+address_from_register (int regnum, struct frame_info *frame)
{
- CORE_ADDR addr = 0;
- struct type *type = SYMBOL_TYPE (var);
- struct value *lazy_value;
+ struct gdbarch *gdbarch = get_frame_arch (frame);
+ struct type *type = builtin_type (gdbarch)->builtin_data_ptr;
+ struct value *value;
+ CORE_ADDR result;
+
+ /* This routine may be called during early unwinding, at a time
+ where the ID of FRAME is not yet known. Calling value_from_register
+ would therefore abort in get_frame_id. However, since we only need
+ a temporary value that is never used as lvalue, we actually do not
+ really need to set its VALUE_FRAME_ID. Therefore, we re-implement
+ the core of value_from_register, but use the null_frame_id. */
+
+ /* Some targets require a special conversion routine even for plain
+ pointer types. Avoid constructing a value object in those cases. */
+ if (gdbarch_convert_register_p (gdbarch, regnum, type))
+ {
+ gdb_byte *buf = alloca (TYPE_LENGTH (type));
+ int optim, unavail, ok;
+
+ ok = gdbarch_register_to_value (gdbarch, frame, regnum, type,
+ buf, &optim, &unavail);
+ if (!ok)
+ {
+ /* This function is used while computing a location expression.
+ Complain about the value being optimized out, rather than
+ letting value_as_address complain about some random register
+ the expression depends on not being saved. */
+ error_value_optimized_out ();
+ }
- /* Evaluate it first; if the result is a memory address, we're fine.
- Lazy evaluation pays off here. */
+ return unpack_long (type, buf);
+ }
- lazy_value = read_var_value (var, frame);
- if (lazy_value == 0)
- error ("Address of \"%s\" is unknown.", SYMBOL_PRINT_NAME (var));
+ value = gdbarch_value_from_register (gdbarch, type, regnum, null_frame_id);
+ read_frame_register_value (value, frame);
- if (value_lazy (lazy_value)
- || TYPE_CODE (type) == TYPE_CODE_FUNC)
+ if (value_optimized_out (value))
{
- struct value *val;
-
- addr = VALUE_ADDRESS (lazy_value);
- val = value_from_pointer (lookup_pointer_type (type), addr);
- return val;
+ /* This function is used while computing a location expression.
+ Complain about the value being optimized out, rather than
+ letting value_as_address complain about some random register
+ the expression depends on not being saved. */
+ error_value_optimized_out ();
}
- /* Not a memory address; check what the problem was. */
- switch (VALUE_LVAL (lazy_value))
- {
- case lval_register:
- gdb_assert (REGISTER_NAME (VALUE_REGNUM (lazy_value)) != NULL
- && *REGISTER_NAME (VALUE_REGNUM (lazy_value)) != '\0');
- error("Address requested for identifier "
- "\"%s\" which is in register $%s",
- SYMBOL_PRINT_NAME (var),
- REGISTER_NAME (VALUE_REGNUM (lazy_value)));
- break;
+ result = value_as_address (value);
+ release_value (value);
+ value_free (value);
- default:
- error ("Can't take address of \"%s\" which isn't an lvalue.",
- SYMBOL_PRINT_NAME (var));
- break;
- }
- return 0; /* For lint -- never reached */
+ return result;
}
+