/* Find a variable's value in memory, for GDB, the GNU debugger.
- Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
- 1996, 1997, 1998, 1999, 2000, 2001, 2003, 2004, 2005, 2007, 2008, 2009,
- 2010, 2011 Free Software Foundation, Inc.
+ Copyright (C) 1986-2014 Free Software Foundation, Inc.
This file is part of GDB.
#include "gdbcore.h"
#include "inferior.h"
#include "target.h"
-#include "gdb_string.h"
+#include <string.h>
#include "gdb_assert.h"
#include "floatformat.h"
#include "symfile.h" /* for overlay functions */
#include "user-regs.h"
#include "block.h"
#include "objfiles.h"
+#include "language.h"
/* Basic byte-swapping routines. All 'extract' functions return a
host-format integer from a target-format integer at ADDR which is
value_of_register (int regnum, struct frame_info *frame)
{
struct gdbarch *gdbarch = get_frame_arch (frame);
- CORE_ADDR addr;
- int optim;
- int unavail;
struct value *reg_val;
- int realnum;
- gdb_byte 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. */
+ gdbarch_num_pseudo_regs (gdbarch))
return value_of_user_reg (regnum, frame);
- frame_register (frame, regnum, &optim, &unavail,
- &lval, &addr, &realnum, raw_buffer);
-
- reg_val = allocate_value (register_type (gdbarch, regnum));
-
- if (!optim && !unavail)
- memcpy (value_contents_raw (reg_val), raw_buffer,
- register_size (gdbarch, regnum));
- else
- memset (value_contents_raw (reg_val), 0,
- register_size (gdbarch, regnum));
-
- VALUE_LVAL (reg_val) = lval;
- set_value_address (reg_val, addr);
- VALUE_REGNUM (reg_val) = regnum;
- set_value_optimized_out (reg_val, optim);
- if (unavail)
- mark_value_bytes_unavailable (reg_val, 0, register_size (gdbarch, regnum));
- VALUE_FRAME_ID (reg_val) = get_frame_id (frame);
+ reg_val = value_of_register_lazy (frame, regnum);
+ value_fetch_lazy (reg_val);
return reg_val;
}
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:
- /* FIXME: cagney/2004-01-26: It should be possible to
- unconditionally call the SYMBOL_COMPUTED_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_COMPUTED_OPS (sym)->read_needs_frame (sym);
+ gdb_assert_not_reached (_("LOC_COMPUTED variable missing a method"));
case LOC_REGISTER:
case LOC_ARG:
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. */
+/* 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 minimal_symbol *result;
+
+ /* The objfile in which the symbol was found. */
+ struct objfile *objfile;
+};
+
+/* 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 == NULL);
+
+ data->result = lookup_minimal_symbol (data->name, NULL, objfile);
+ data->objfile = objfile;
+
+ /* The iterator should stop iff a match was found. */
+ return (data->result != NULL);
+}
+
+/* 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, struct frame_info *frame)
{
struct value *v;
struct type *type = SYMBOL_TYPE (var);
CORE_ADDR addr;
- int len;
/* 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
set the returned value type description correctly. */
check_typedef (type);
- len = TYPE_LENGTH (type);
-
if (symbol_read_needs_frame (var))
gdb_assert (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. */
v = allocate_value (type);
- store_signed_integer (value_contents_raw (v), len,
+ 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;
{
CORE_ADDR addr
= symbol_overlayed_address (SYMBOL_VALUE_ADDRESS (var),
- SYMBOL_OBJ_SECTION (var));
+ SYMBOL_OBJ_SECTION (SYMBOL_OBJFILE (var),
+ var));
store_typed_address (value_contents_raw (v), type, addr);
}
case LOC_CONST_BYTES:
v = allocate_value (type);
- memcpy (value_contents_raw (v), SYMBOL_VALUE_BYTES (var), len);
+ memcpy (value_contents_raw (v), SYMBOL_VALUE_BYTES (var),
+ TYPE_LENGTH (type));
VALUE_LVAL (v) = not_lval;
return v;
case LOC_STATIC:
- v = allocate_value_lazy (type);
if (overlay_debugging)
addr = symbol_overlayed_address (SYMBOL_VALUE_ADDRESS (var),
- SYMBOL_OBJ_SECTION (var));
+ SYMBOL_OBJ_SECTION (SYMBOL_OBJFILE (var),
+ var));
else
addr = SYMBOL_VALUE_ADDRESS (var);
break;
case LOC_ARG:
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);
- v = allocate_value_lazy (type);
break;
case LOC_REF_ARG:
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);
- v = allocate_value_lazy (type);
break;
}
case LOC_LOCAL:
addr = get_frame_locals_address (frame);
addr += SYMBOL_VALUE (var);
- v = allocate_value_lazy (type);
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:
- v = allocate_value_lazy (type);
if (overlay_debugging)
addr = symbol_overlayed_address
- (BLOCK_START (SYMBOL_BLOCK_VALUE (var)), SYMBOL_OBJ_SECTION (var));
+ (BLOCK_START (SYMBOL_BLOCK_VALUE (var)), SYMBOL_OBJ_SECTION (SYMBOL_OBJFILE (var),
+ var));
else
addr = BLOCK_START (SYMBOL_BLOCK_VALUE (var));
break;
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);
- v = allocate_value_lazy (type);
}
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:
- /* FIXME: cagney/2004-01-26: It should be possible to
- unconditionally call the SYMBOL_COMPUTED_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_COMPUTED_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;
- msym = lookup_minimal_symbol (SYMBOL_LINKAGE_NAME (var), NULL, NULL);
+ memset (&lookup_data, 0, sizeof (lookup_data));
+ lookup_data.name = SYMBOL_LINKAGE_NAME (var);
+
+ gdbarch_iterate_over_objfiles_in_search_order
+ (get_objfile_arch (SYMBOL_SYMTAB (var)->objfile),
+ minsym_lookup_iterator_cb, &lookup_data,
+ SYMBOL_SYMTAB (var)->objfile);
+ msym = lookup_data.result;
+
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_OBJ_SECTION (msym));
+ SYMBOL_OBJ_SECTION (lookup_data.objfile,
+ msym));
else
addr = SYMBOL_VALUE_ADDRESS (msym);
- obj_section = SYMBOL_OBJ_SECTION (msym);
+ obj_section = SYMBOL_OBJ_SECTION (lookup_data.objfile, msym);
if (obj_section
&& (obj_section->the_bfd_section->flags & SEC_THREAD_LOCAL) != 0)
addr = target_translate_tls_address (obj_section->objfile, addr);
- v = allocate_value_lazy (type);
}
break;
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_LVAL (v) = lval_memory;
- set_value_address (v, addr);
+ v = value_at_lazy (type, addr);
return v;
}
+/* Calls VAR's language la_read_var_value hook with the given arguments. */
+
+struct value *
+read_var_value (struct symbol *var, 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);
+
+ return lang->la_read_var_value (var, frame);
+}
+
/* Install default attributes for register values. */
struct value *
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);
+ int offset = 0;
+ int reg_offset = value_offset (value);
+ int regnum = VALUE_REGNUM (value);
+ int len = TYPE_LENGTH (check_typedef (value_type (value)));
+
+ gdb_assert (VALUE_LVAL (value) == lval_register);
+
+ /* Skip registers wholly inside of REG_OFFSET. */
+ while (reg_offset >= register_size (gdbarch, regnum))
+ {
+ reg_offset -= register_size (gdbarch, regnum);
+ regnum++;
+ }
+
+ /* Copy the data. */
+ while (len > 0)
+ {
+ struct value *regval = get_frame_register_value (frame, regnum);
+ int reg_len = TYPE_LENGTH (value_type (regval)) - reg_offset;
+
+ if (value_optimized_out (regval))
+ {
+ set_value_optimized_out (value, 1);
+ break;
+ }
+
+ /* 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 *
struct gdbarch *gdbarch = get_frame_arch (frame);
struct type *type1 = check_typedef (type);
struct value *v;
- int optim, unavail, ok;
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
ok = gdbarch_register_to_value (gdbarch, frame, regnum, type1,
value_contents_raw (v), &optim,
&unavail);
+
+ if (!ok)
+ {
+ if (optim)
+ set_value_optimized_out (v, 1);
+ if (unavail)
+ mark_value_bytes_unavailable (v, 0, TYPE_LENGTH (type));
+ }
}
else
{
- int len = TYPE_LENGTH (type);
-
/* Construct the value. */
v = gdbarch_value_from_register (gdbarch, type, regnum, frame);
/* Get the data. */
- ok = get_frame_register_bytes (frame, regnum, value_offset (v), len,
- value_contents_raw (v),
- &optim, &unavail);
- }
-
- if (!ok)
- {
- if (optim)
- set_value_optimized_out (v, 1);
- if (unavail)
- mark_value_bytes_unavailable (v, 0, TYPE_LENGTH (type));
+ read_frame_register_value (v, frame);
}
return v;
value = value_from_register (type, regnum, frame);
gdb_assert (value);
+ if (value_optimized_out (value))
+ {
+ /* 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 ();
+ }
+
result = value_as_address (value);
release_value (value);
value_free (value);
return result;
}
+
projects / deliverable / binutils-gdb.git / blobdiff