binutils-gdb/gdb/c-valprint.c
Caroline Tice 42be36b328 Add ability to report when a variable's value is uninitialized,
based on information provided by the compiler.  Also add new
DWARF OP, DW_OP_GNU_uninit, for this purpose.
2007-05-18 19:42:42 +00:00

597 lines
18 KiB
C
Raw Blame History

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/* Support for printing C values for GDB, the GNU debugger.
Copyright (C) 1986, 1988, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
1998, 1999, 2000, 2001, 2003, 2005, 2006, 2007
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., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA. */
#include "defs.h"
#include "gdb_string.h"
#include "symtab.h"
#include "gdbtypes.h"
#include "expression.h"
#include "value.h"
#include "valprint.h"
#include "language.h"
#include "c-lang.h"
#include "cp-abi.h"
#include "target.h"
/* Print function pointer with inferior address ADDRESS onto stdio
stream STREAM. */
static void
print_function_pointer_address (CORE_ADDR address, struct ui_file *stream)
{
CORE_ADDR func_addr = gdbarch_convert_from_func_ptr_addr (current_gdbarch,
address,
&current_target);
/* If the function pointer is represented by a description, print the
address of the description. */
if (addressprint && func_addr != address)
{
fputs_filtered ("@", stream);
deprecated_print_address_numeric (address, 1, stream);
fputs_filtered (": ", stream);
}
print_address_demangle (func_addr, stream, demangle);
}
/* Print data of type TYPE located at VALADDR (within GDB), which came from
the inferior at address ADDRESS, onto stdio stream STREAM according to
FORMAT (a letter or 0 for natural format). The data at VALADDR is in
target byte order.
If the data are a string pointer, returns the number of string characters
printed.
If DEREF_REF is nonzero, then dereference references, otherwise just print
them like pointers.
The PRETTY parameter controls prettyprinting. */
int
c_val_print (struct type *type, const gdb_byte *valaddr, int embedded_offset,
CORE_ADDR address, struct ui_file *stream, int format,
int deref_ref, int recurse, enum val_prettyprint pretty)
{
unsigned int i = 0; /* Number of characters printed */
unsigned len;
struct type *elttype;
unsigned eltlen;
LONGEST val;
CORE_ADDR addr;
CHECK_TYPEDEF (type);
switch (TYPE_CODE (type))
{
case TYPE_CODE_ARRAY:
elttype = check_typedef (TYPE_TARGET_TYPE (type));
if (TYPE_LENGTH (type) > 0 && TYPE_LENGTH (TYPE_TARGET_TYPE (type)) > 0)
{
eltlen = TYPE_LENGTH (elttype);
len = TYPE_LENGTH (type) / eltlen;
if (prettyprint_arrays)
{
print_spaces_filtered (2 + 2 * recurse, stream);
}
/* For an array of chars, print with string syntax. */
if (eltlen == 1 &&
((TYPE_CODE (elttype) == TYPE_CODE_INT && TYPE_NOSIGN (elttype))
|| ((current_language->la_language == language_m2)
&& (TYPE_CODE (elttype) == TYPE_CODE_CHAR)))
&& (format == 0 || format == 's'))
{
/* If requested, look for the first null char and only print
elements up to it. */
if (stop_print_at_null)
{
unsigned int temp_len;
/* Look for a NULL char. */
for (temp_len = 0;
(valaddr + embedded_offset)[temp_len]
&& temp_len < len && temp_len < print_max;
temp_len++);
len = temp_len;
}
LA_PRINT_STRING (stream, valaddr + embedded_offset, len, eltlen, 0);
i = len;
}
else
{
fprintf_filtered (stream, "{");
/* If this is a virtual function table, print the 0th
entry specially, and the rest of the members normally. */
if (cp_is_vtbl_ptr_type (elttype))
{
i = 1;
fprintf_filtered (stream, _("%d vtable entries"), len - 1);
}
else
{
i = 0;
}
val_print_array_elements (type, valaddr + embedded_offset, address, stream,
format, deref_ref, recurse, pretty, i);
fprintf_filtered (stream, "}");
}
break;
}
/* Array of unspecified length: treat like pointer to first elt. */
addr = address;
goto print_unpacked_pointer;
case TYPE_CODE_MEMBERPTR:
if (format)
{
print_scalar_formatted (valaddr + embedded_offset, type, format, 0, stream);
break;
}
cp_print_class_member (valaddr + embedded_offset,
TYPE_DOMAIN_TYPE (type),
stream, "&");
break;
case TYPE_CODE_METHODPTR:
cplus_print_method_ptr (valaddr + embedded_offset, type, stream);
break;
case TYPE_CODE_PTR:
if (format && format != 's')
{
print_scalar_formatted (valaddr + embedded_offset, type, format, 0, stream);
break;
}
if (vtblprint && cp_is_vtbl_ptr_type (type))
{
/* Print the unmangled name if desired. */
/* Print vtable entry - we only get here if we ARE using
-fvtable_thunks. (Otherwise, look under TYPE_CODE_STRUCT.) */
CORE_ADDR addr
= extract_typed_address (valaddr + embedded_offset, type);
print_function_pointer_address (addr, stream);
break;
}
elttype = check_typedef (TYPE_TARGET_TYPE (type));
{
addr = unpack_pointer (type, valaddr + embedded_offset);
print_unpacked_pointer:
if (TYPE_CODE (elttype) == TYPE_CODE_FUNC)
{
/* Try to print what function it points to. */
print_function_pointer_address (addr, stream);
/* Return value is irrelevant except for string pointers. */
return (0);
}
if (addressprint && format != 's')
{
deprecated_print_address_numeric (addr, 1, stream);
}
/* For a pointer to char or unsigned char, also print the string
pointed to, unless pointer is null. */
/* FIXME: need to handle wchar_t here... */
if (TYPE_LENGTH (elttype) == 1
&& TYPE_CODE (elttype) == TYPE_CODE_INT
&& (format == 0 || format == 's')
&& addr != 0)
{
i = val_print_string (addr, -1, TYPE_LENGTH (elttype), stream);
}
else if (cp_is_vtbl_member (type))
{
/* print vtbl's nicely */
CORE_ADDR vt_address = unpack_pointer (type, valaddr + embedded_offset);
struct minimal_symbol *msymbol =
lookup_minimal_symbol_by_pc (vt_address);
if ((msymbol != NULL) &&
(vt_address == SYMBOL_VALUE_ADDRESS (msymbol)))
{
fputs_filtered (" <", stream);
fputs_filtered (SYMBOL_PRINT_NAME (msymbol), stream);
fputs_filtered (">", stream);
}
if (vt_address && vtblprint)
{
struct value *vt_val;
struct symbol *wsym = (struct symbol *) NULL;
struct type *wtype;
struct block *block = (struct block *) NULL;
int is_this_fld;
if (msymbol != NULL)
wsym = lookup_symbol (DEPRECATED_SYMBOL_NAME (msymbol), block,
VAR_DOMAIN, &is_this_fld, NULL);
if (wsym)
{
wtype = SYMBOL_TYPE (wsym);
}
else
{
wtype = TYPE_TARGET_TYPE (type);
}
vt_val = value_at (wtype, vt_address);
common_val_print (vt_val, stream, format,
deref_ref, recurse + 1, pretty);
if (pretty)
{
fprintf_filtered (stream, "\n");
print_spaces_filtered (2 + 2 * recurse, stream);
}
}
}
/* Return number of characters printed, including the terminating
'\0' if we reached the end. val_print_string takes care including
the terminating '\0' if necessary. */
return i;
}
break;
case TYPE_CODE_REF:
elttype = check_typedef (TYPE_TARGET_TYPE (type));
if (addressprint)
{
CORE_ADDR addr
= extract_typed_address (valaddr + embedded_offset, type);
fprintf_filtered (stream, "@");
deprecated_print_address_numeric (addr, 1, stream);
if (deref_ref)
fputs_filtered (": ", stream);
}
/* De-reference the reference. */
if (deref_ref)
{
if (TYPE_CODE (elttype) != TYPE_CODE_UNDEF)
{
struct value *deref_val =
value_at
(TYPE_TARGET_TYPE (type),
unpack_pointer (lookup_pointer_type (builtin_type_void),
valaddr + embedded_offset));
common_val_print (deref_val, stream, format, deref_ref,
recurse, pretty);
}
else
fputs_filtered ("???", stream);
}
break;
case TYPE_CODE_UNION:
if (recurse && !unionprint)
{
fprintf_filtered (stream, "{...}");
break;
}
/* Fall through. */
case TYPE_CODE_STRUCT:
/*FIXME: Abstract this away */
if (vtblprint && cp_is_vtbl_ptr_type (type))
{
/* Print the unmangled name if desired. */
/* Print vtable entry - we only get here if NOT using
-fvtable_thunks. (Otherwise, look under TYPE_CODE_PTR.) */
int offset = (embedded_offset +
TYPE_FIELD_BITPOS (type, VTBL_FNADDR_OFFSET) / 8);
struct type *field_type = TYPE_FIELD_TYPE (type, VTBL_FNADDR_OFFSET);
CORE_ADDR addr
= extract_typed_address (valaddr + offset, field_type);
print_function_pointer_address (addr, stream);
}
else
cp_print_value_fields (type, type, valaddr, embedded_offset, address, stream, format,
recurse, pretty, NULL, 0);
break;
case TYPE_CODE_ENUM:
if (format)
{
print_scalar_formatted (valaddr + embedded_offset, type, format, 0, stream);
break;
}
len = TYPE_NFIELDS (type);
val = unpack_long (type, valaddr + embedded_offset);
for (i = 0; i < len; i++)
{
QUIT;
if (val == TYPE_FIELD_BITPOS (type, i))
{
break;
}
}
if (i < len)
{
fputs_filtered (TYPE_FIELD_NAME (type, i), stream);
}
else
{
print_longest (stream, 'd', 0, val);
}
break;
case TYPE_CODE_FLAGS:
if (format)
print_scalar_formatted (valaddr + embedded_offset, type, format, 0, stream);
else
val_print_type_code_flags (type, valaddr + embedded_offset, stream);
break;
case TYPE_CODE_FUNC:
case TYPE_CODE_METHOD:
if (format)
{
print_scalar_formatted (valaddr + embedded_offset, type, format, 0, stream);
break;
}
/* FIXME, we should consider, at least for ANSI C language, eliminating
the distinction made between FUNCs and POINTERs to FUNCs. */
fprintf_filtered (stream, "{");
type_print (type, "", stream, -1);
fprintf_filtered (stream, "} ");
/* Try to print what function it points to, and its address. */
print_address_demangle (address, stream, demangle);
break;
case TYPE_CODE_BOOL:
format = format ? format : output_format;
if (format)
print_scalar_formatted (valaddr + embedded_offset, type, format, 0, stream);
else
{
val = unpack_long (type, valaddr + embedded_offset);
if (val == 0)
fputs_filtered ("false", stream);
else if (val == 1)
fputs_filtered ("true", stream);
else
print_longest (stream, 'd', 0, val);
}
break;
case TYPE_CODE_RANGE:
/* FIXME: create_range_type does not set the unsigned bit in a
range type (I think it probably should copy it from the target
type), so we won't print values which are too large to
fit in a signed integer correctly. */
/* FIXME: Doesn't handle ranges of enums correctly. (Can't just
print with the target type, though, because the size of our type
and the target type might differ). */
/* FALLTHROUGH */
case TYPE_CODE_INT:
format = format ? format : output_format;
if (format)
{
print_scalar_formatted (valaddr + embedded_offset, type, format, 0, stream);
}
else
{
val_print_type_code_int (type, valaddr + embedded_offset, stream);
/* C and C++ has no single byte int type, char is used instead.
Since we don't know whether the value is really intended to
be used as an integer or a character, print the character
equivalent as well. */
if (TYPE_LENGTH (type) == 1)
{
fputs_filtered (" ", stream);
LA_PRINT_CHAR ((unsigned char) unpack_long (type, valaddr + embedded_offset),
stream);
}
}
break;
case TYPE_CODE_CHAR:
format = format ? format : output_format;
if (format)
{
print_scalar_formatted (valaddr + embedded_offset, type, format, 0, stream);
}
else
{
val = unpack_long (type, valaddr + embedded_offset);
if (TYPE_UNSIGNED (type))
fprintf_filtered (stream, "%u", (unsigned int) val);
else
fprintf_filtered (stream, "%d", (int) val);
fputs_filtered (" ", stream);
LA_PRINT_CHAR ((unsigned char) val, stream);
}
break;
case TYPE_CODE_FLT:
if (format)
{
print_scalar_formatted (valaddr + embedded_offset, type, format, 0, stream);
}
else
{
print_floating (valaddr + embedded_offset, type, stream);
}
break;
case TYPE_CODE_VOID:
fprintf_filtered (stream, "void");
break;
case TYPE_CODE_ERROR:
fprintf_filtered (stream, _("<error type>"));
break;
case TYPE_CODE_UNDEF:
/* This happens (without TYPE_FLAG_STUB set) on systems which don't use
dbx xrefs (NO_DBX_XREFS in gcc) if a file has a "struct foo *bar"
and no complete type for struct foo in that file. */
fprintf_filtered (stream, _("<incomplete type>"));
break;
case TYPE_CODE_COMPLEX:
if (format)
print_scalar_formatted (valaddr + embedded_offset,
TYPE_TARGET_TYPE (type),
format, 0, stream);
else
print_floating (valaddr + embedded_offset, TYPE_TARGET_TYPE (type),
stream);
fprintf_filtered (stream, " + ");
if (format)
print_scalar_formatted (valaddr + embedded_offset
+ TYPE_LENGTH (TYPE_TARGET_TYPE (type)),
TYPE_TARGET_TYPE (type),
format, 0, stream);
else
print_floating (valaddr + embedded_offset
+ TYPE_LENGTH (TYPE_TARGET_TYPE (type)),
TYPE_TARGET_TYPE (type),
stream);
fprintf_filtered (stream, " * I");
break;
default:
error (_("Invalid C/C++ type code %d in symbol table."), TYPE_CODE (type));
}
gdb_flush (stream);
return (0);
}
int
c_value_print (struct value *val, struct ui_file *stream, int format,
enum val_prettyprint pretty)
{
struct type *type, *real_type;
int full, top, using_enc;
/* If it is a pointer, indicate what it points to.
Print type also if it is a reference.
C++: if it is a member pointer, we will take care
of that when we print it. */
type = check_typedef (value_type (val));
if (TYPE_CODE (type) == TYPE_CODE_PTR
|| TYPE_CODE (type) == TYPE_CODE_REF)
{
/* Hack: remove (char *) for char strings. Their
type is indicated by the quoted string anyway. */
if (TYPE_CODE (type) == TYPE_CODE_PTR
&& TYPE_NAME (type) == NULL
&& TYPE_NAME (TYPE_TARGET_TYPE (type)) != NULL
&& strcmp (TYPE_NAME (TYPE_TARGET_TYPE (type)), "char") == 0)
{
/* Print nothing */
}
else if (objectprint && (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_CLASS))
{
if (TYPE_CODE(type) == TYPE_CODE_REF)
{
/* Copy value, change to pointer, so we don't get an
* error about a non-pointer type in value_rtti_target_type
*/
struct value *temparg;
temparg=value_copy(val);
deprecated_set_value_type (temparg, lookup_pointer_type (TYPE_TARGET_TYPE(type)));
val=temparg;
}
/* Pointer to class, check real type of object */
fprintf_filtered (stream, "(");
real_type = value_rtti_target_type (val, &full, &top, &using_enc);
if (real_type)
{
/* RTTI entry found */
if (TYPE_CODE (type) == TYPE_CODE_PTR)
{
/* create a pointer type pointing to the real type */
type = lookup_pointer_type (real_type);
}
else
{
/* create a reference type referencing the real type */
type = lookup_reference_type (real_type);
}
/* JYG: Need to adjust pointer value. */
/* NOTE: cagney/2005-01-02: THIS IS BOGUS. */
value_contents_writeable (val)[0] -= top;
/* Note: When we look up RTTI entries, we don't get any
information on const or volatile attributes */
}
type_print (type, "", stream, -1);
fprintf_filtered (stream, ") ");
}
else
{
/* normal case */
fprintf_filtered (stream, "(");
type_print (value_type (val), "", stream, -1);
fprintf_filtered (stream, ") ");
}
}
if (!value_initialized (val))
fprintf_filtered (stream, " [uninitialized] ");
if (objectprint && (TYPE_CODE (type) == TYPE_CODE_CLASS))
{
/* Attempt to determine real type of object */
real_type = value_rtti_type (val, &full, &top, &using_enc);
if (real_type)
{
/* We have RTTI information, so use it */
val = value_full_object (val, real_type, full, top, using_enc);
fprintf_filtered (stream, "(%s%s) ",
TYPE_NAME (real_type),
full ? "" : _(" [incomplete object]"));
/* Print out object: enclosing type is same as real_type if full */
return val_print (value_enclosing_type (val),
value_contents_all (val), 0,
VALUE_ADDRESS (val), stream, format, 1, 0, pretty);
/* Note: When we look up RTTI entries, we don't get any information on
const or volatile attributes */
}
else if (type != check_typedef (value_enclosing_type (val)))
{
/* No RTTI information, so let's do our best */
fprintf_filtered (stream, "(%s ?) ",
TYPE_NAME (value_enclosing_type (val)));
return val_print (value_enclosing_type (val),
value_contents_all (val), 0,
VALUE_ADDRESS (val), stream, format, 1, 0, pretty);
}
/* Otherwise, we end up at the return outside this "if" */
}
return val_print (type, value_contents_all (val),
value_embedded_offset (val),
VALUE_ADDRESS (val) + value_offset (val),
stream, format, 1, 0, pretty);
}