/* Low level packing and unpacking of values for GDB, the GNU Debugger.
- Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
- 1996, 1997, 1998, 1999, 2000
+ Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994,
+ 1995, 1996, 1997, 1998, 1999, 2000, 2002.
Free Software Foundation, Inc.
This file is part of GDB.
#include "scm-lang.h"
#include "demangle.h"
#include "doublest.h"
+#include "gdb_assert.h"
/* Prototypes for exported functions. */
/* Prototypes for local functions. */
-static value_ptr value_headof (value_ptr, struct type *, struct type *);
+static struct value *value_headof (struct value *, struct type *, struct type *);
static void show_values (char *, int);
struct value_history_chunk
{
struct value_history_chunk *next;
- value_ptr values[VALUE_HISTORY_CHUNK];
+ struct value *values[VALUE_HISTORY_CHUNK];
};
/* Chain of chunks now in use. */
(except for those released by calls to release_value)
This is so they can be freed after each command. */
-static value_ptr all_values;
+static struct value *all_values;
/* Allocate a value that has the correct length for type TYPE. */
-value_ptr
+struct value *
allocate_value (struct type *type)
{
- register value_ptr val;
+ struct value *val;
struct type *atype = check_typedef (type);
val = (struct value *) xmalloc (sizeof (struct value) + TYPE_LENGTH (atype));
/* Allocate a value that has the correct length
for COUNT repetitions type TYPE. */
-value_ptr
+struct value *
allocate_repeat_value (struct type *type, int count)
{
int low_bound = current_language->string_lower_bound; /* ??? */
/* Return a mark in the value chain. All values allocated after the
mark is obtained (except for those released) are subject to being freed
if a subsequent value_free_to_mark is passed the mark. */
-value_ptr
+struct value *
value_mark (void)
{
return all_values;
/* Free all values allocated since MARK was obtained by value_mark
(except for those released). */
void
-value_free_to_mark (value_ptr mark)
+value_free_to_mark (struct value *mark)
{
- value_ptr val, next;
+ struct value *val;
+ struct value *next;
for (val = all_values; val && val != mark; val = next)
{
void
free_all_values (void)
{
- register value_ptr val, next;
+ struct value *val;
+ struct value *next;
for (val = all_values; val; val = next)
{
so it will not be freed automatically. */
void
-release_value (register value_ptr val)
+release_value (struct value *val)
{
- register value_ptr v;
+ struct value *v;
if (all_values == val)
{
}
/* Release all values up to mark */
-value_ptr
-value_release_to_mark (value_ptr mark)
+struct value *
+value_release_to_mark (struct value *mark)
{
- value_ptr val, next;
+ struct value *val;
+ struct value *next;
for (val = next = all_values; next; next = VALUE_NEXT (next))
if (VALUE_NEXT (next) == mark)
It contains the same contents, for same memory address,
but it's a different block of storage. */
-value_ptr
-value_copy (value_ptr arg)
+struct value *
+value_copy (struct value *arg)
{
register struct type *encl_type = VALUE_ENCLOSING_TYPE (arg);
- register value_ptr val = allocate_value (encl_type);
+ struct value *val = allocate_value (encl_type);
VALUE_TYPE (val) = VALUE_TYPE (arg);
VALUE_LVAL (val) = VALUE_LVAL (arg);
VALUE_ADDRESS (val) = VALUE_ADDRESS (arg);
value history index of this new item. */
int
-record_latest_value (value_ptr val)
+record_latest_value (struct value *val)
{
int i;
i = value_history_count % VALUE_HISTORY_CHUNK;
if (i == 0)
{
- register struct value_history_chunk *new
+ struct value_history_chunk *new
= (struct value_history_chunk *)
xmalloc (sizeof (struct value_history_chunk));
memset (new->values, 0, sizeof new->values);
/* Return a copy of the value in the history with sequence number NUM. */
-value_ptr
+struct value *
access_value_history (int num)
{
- register struct value_history_chunk *chunk;
+ struct value_history_chunk *chunk;
register int i;
register int absnum = num;
void
clear_value_history (void)
{
- register struct value_history_chunk *next;
+ struct value_history_chunk *next;
register int i;
- register value_ptr val;
+ struct value *val;
while (value_history_chain)
{
show_values (char *num_exp, int from_tty)
{
register int i;
- register value_ptr val;
+ struct value *val;
static int num = 1;
if (num_exp)
return var;
}
-value_ptr
+struct value *
value_of_internalvar (struct internalvar *var)
{
- register value_ptr val;
+ struct value *val;
#ifdef IS_TRAPPED_INTERNALVAR
if (IS_TRAPPED_INTERNALVAR (var->name))
void
set_internalvar_component (struct internalvar *var, int offset, int bitpos,
- int bitsize, value_ptr newval)
+ int bitsize, struct value *newval)
{
register char *addr = VALUE_CONTENTS (var->value) + offset;
}
void
-set_internalvar (struct internalvar *var, value_ptr val)
+set_internalvar (struct internalvar *var, struct value *val)
{
- value_ptr newval;
+ struct value *newval;
#ifdef IS_TRAPPED_INTERNALVAR
if (IS_TRAPPED_INTERNALVAR (var->name))
Does not deallocate the value. */
LONGEST
-value_as_long (register value_ptr val)
+value_as_long (struct value *val)
{
/* This coerces arrays and functions, which is necessary (e.g.
in disassemble_command). It also dereferences references, which
}
DOUBLEST
-value_as_double (register value_ptr val)
+value_as_double (struct value *val)
{
DOUBLEST foo;
int inv;
Note that val's type may not actually be a pointer; value_as_long
handles all the cases. */
CORE_ADDR
-value_as_address (value_ptr val)
+value_as_address (struct value *val)
{
/* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
whether we want this to be true eventually. */
for pointers to char, in which the low bits *are* significant. */
return ADDR_BITS_REMOVE (value_as_long (val));
#else
+
+ /* There are several targets (IA-64, PowerPC, and others) which
+ don't represent pointers to functions as simply the address of
+ the function's entry point. For example, on the IA-64, a
+ function pointer points to a two-word descriptor, generated by
+ the linker, which contains the function's entry point, and the
+ value the IA-64 "global pointer" register should have --- to
+ support position-independent code. The linker generates
+ descriptors only for those functions whose addresses are taken.
+
+ On such targets, it's difficult for GDB to convert an arbitrary
+ function address into a function pointer; it has to either find
+ an existing descriptor for that function, or call malloc and
+ build its own. On some targets, it is impossible for GDB to
+ build a descriptor at all: the descriptor must contain a jump
+ instruction; data memory cannot be executed; and code memory
+ cannot be modified.
+
+ Upon entry to this function, if VAL is a value of type `function'
+ (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
+ VALUE_ADDRESS (val) is the address of the function. This is what
+ you'll get if you evaluate an expression like `main'. The call
+ to COERCE_ARRAY below actually does all the usual unary
+ conversions, which includes converting values of type `function'
+ to `pointer to function'. This is the challenging conversion
+ discussed above. Then, `unpack_long' will convert that pointer
+ back into an address.
+
+ So, suppose the user types `disassemble foo' on an architecture
+ with a strange function pointer representation, on which GDB
+ cannot build its own descriptors, and suppose further that `foo'
+ has no linker-built descriptor. The address->pointer conversion
+ will signal an error and prevent the command from running, even
+ though the next step would have been to convert the pointer
+ directly back into the same address.
+
+ The following shortcut avoids this whole mess. If VAL is a
+ function, just return its address directly. */
+ if (TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC
+ || TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_METHOD)
+ return VALUE_ADDRESS (val);
+
COERCE_ARRAY (val);
/* Some architectures (e.g. Harvard), map instruction and data
nosign = TYPE_UNSIGNED (type);
if (code == TYPE_CODE_FLT)
{
-#ifdef INVALID_FLOAT
- if (INVALID_FLOAT (valaddr, len))
- {
- *invp = 1;
- return 1.234567891011121314;
- }
-#endif
+ /* NOTE: cagney/2002-02-19: There was a test here to see if the
+ floating-point value was valid (using the macro
+ INVALID_FLOAT). That test/macro have been removed.
+
+ It turns out that only the VAX defined this macro and then
+ only in a non-portable way. Fixing the portability problem
+ wouldn't help since the VAX floating-point code is also badly
+ bit-rotten. The target needs to add definitions for the
+ methods TARGET_FLOAT_FORMAT and TARGET_DOUBLE_FORMAT - these
+ exactly describe the target floating-point format. The
+ problem here is that the corresponding floatformat_vax_f and
+ floatformat_vax_d values these methods should be set to are
+ also not defined either. Oops!
+
+ Hopefully someone will add both the missing floatformat
+ definitions and floatformat_is_invalid() function. */
return extract_typed_floating (valaddr, type);
}
else if (nosign)
\f
/* Get the value of the FIELDN'th field (which must be static) of TYPE. */
-value_ptr
+struct value *
value_static_field (struct type *type, int fieldno)
{
CORE_ADDR addr;
than the old enclosing type, you have to allocate more space for the data.
The return value is a pointer to the new version of this value structure. */
-value_ptr
-value_change_enclosing_type (value_ptr val, struct type *new_encl_type)
+struct value *
+value_change_enclosing_type (struct value *val, struct type *new_encl_type)
{
if (TYPE_LENGTH (new_encl_type) <= TYPE_LENGTH (VALUE_ENCLOSING_TYPE (val)))
{
}
else
{
- value_ptr new_val;
- register value_ptr prev;
+ struct value *new_val;
+ struct value *prev;
- new_val = (value_ptr) xrealloc (val, sizeof (struct value) + TYPE_LENGTH (new_encl_type));
+ new_val = (struct value *) xrealloc (val, sizeof (struct value) + TYPE_LENGTH (new_encl_type));
/* We have to make sure this ends up in the same place in the value
chain as the original copy, so it's clean-up behavior is the same.
extract and return the value of one of its (non-static) fields.
FIELDNO says which field. */
-value_ptr
-value_primitive_field (register value_ptr arg1, int offset,
+struct value *
+value_primitive_field (struct value *arg1, int offset,
register int fieldno, register struct type *arg_type)
{
- register value_ptr v;
+ struct value *v;
register struct type *type;
CHECK_TYPEDEF (arg_type);
memcpy (VALUE_CONTENTS_RAW (v),
VALUE_CONTENTS_RAW (arg1) + offset,
TYPE_LENGTH (type));
- VALUE_OFFSET (v) = VALUE_OFFSET (arg1) + offset;
+ VALUE_OFFSET (v) = VALUE_OFFSET (arg1) + offset
+ + VALUE_EMBEDDED_OFFSET (arg1);
}
VALUE_LVAL (v) = VALUE_LVAL (arg1);
if (VALUE_LVAL (arg1) == lval_internalvar)
extract and return the value of one of its (non-static) fields.
FIELDNO says which field. */
-value_ptr
-value_field (register value_ptr arg1, register int fieldno)
+struct value *
+value_field (struct value *arg1, register int fieldno)
{
return value_primitive_field (arg1, 0, fieldno, VALUE_TYPE (arg1));
}
/* Return a non-virtual function as a value.
F is the list of member functions which contains the desired method.
- J is an index into F which provides the desired method. */
+ J is an index into F which provides the desired method.
-value_ptr
-value_fn_field (value_ptr *arg1p, struct fn_field *f, int j, struct type *type,
+ We only use the symbol for its address, so be happy with either a
+ full symbol or a minimal symbol.
+ */
+
+struct value *
+value_fn_field (struct value **arg1p, struct fn_field *f, int j, struct type *type,
int offset)
{
- register value_ptr v;
+ struct value *v;
register struct type *ftype = TYPE_FN_FIELD_TYPE (f, j);
+ char *physname = TYPE_FN_FIELD_PHYSNAME (f, j);
struct symbol *sym;
+ struct minimal_symbol *msym;
- sym = lookup_symbol (TYPE_FN_FIELD_PHYSNAME (f, j),
- 0, VAR_NAMESPACE, 0, NULL);
- if (!sym)
- return NULL;
-/*
- error ("Internal error: could not find physical method named %s",
- TYPE_FN_FIELD_PHYSNAME (f, j));
- */
+ sym = lookup_symbol (physname, 0, VAR_NAMESPACE, 0, NULL);
+ if (sym != NULL)
+ {
+ msym = NULL;
+ }
+ else
+ {
+ gdb_assert (sym == NULL);
+ msym = lookup_minimal_symbol (physname, NULL, NULL);
+ if (msym == NULL)
+ return NULL;
+ }
v = allocate_value (ftype);
- VALUE_ADDRESS (v) = BLOCK_START (SYMBOL_BLOCK_VALUE (sym));
- VALUE_TYPE (v) = ftype;
+ if (sym)
+ {
+ VALUE_ADDRESS (v) = BLOCK_START (SYMBOL_BLOCK_VALUE (sym));
+ }
+ else
+ {
+ VALUE_ADDRESS (v) = SYMBOL_VALUE_ADDRESS (msym);
+ }
if (arg1p)
{
by value_rtti_type efficiently.
Consider it gone for 5.1. */
-static value_ptr
-value_headof (value_ptr in_arg, struct type *btype, struct type *dtype)
+static struct value *
+value_headof (struct value *in_arg, struct type *btype, struct type *dtype)
{
/* First collect the vtables we must look at for this object. */
- value_ptr arg, vtbl;
+ struct value *arg;
+ struct value *vtbl;
struct symbol *sym;
char *demangled_name;
struct minimal_symbol *msymbol;
of its baseclasses) to figure out the most derived type that ARG
could actually be a pointer to. */
-value_ptr
-value_from_vtable_info (value_ptr arg, struct type *type)
+struct value *
+value_from_vtable_info (struct value *arg, struct type *type)
{
/* Take care of preliminaries. */
if (TYPE_VPTR_FIELDNO (type) < 0)
return value_headof (arg, 0, type);
}
-
-/* Return true if the INDEXth field of TYPE is a virtual baseclass
- pointer which is for the base class whose type is BASECLASS. */
-
-static int
-vb_match (struct type *type, int index, struct type *basetype)
-{
- struct type *fieldtype;
- char *name = TYPE_FIELD_NAME (type, index);
- char *field_class_name = NULL;
-
- if (*name != '_')
- return 0;
- /* gcc 2.4 uses _vb$. */
- if (name[1] == 'v' && name[2] == 'b' && is_cplus_marker (name[3]))
- field_class_name = name + 4;
- /* gcc 2.5 will use __vb_. */
- if (name[1] == '_' && name[2] == 'v' && name[3] == 'b' && name[4] == '_')
- field_class_name = name + 5;
-
- if (field_class_name == NULL)
- /* This field is not a virtual base class pointer. */
- return 0;
-
- /* It's a virtual baseclass pointer, now we just need to find out whether
- it is for this baseclass. */
- fieldtype = TYPE_FIELD_TYPE (type, index);
- if (fieldtype == NULL
- || TYPE_CODE (fieldtype) != TYPE_CODE_PTR)
- /* "Can't happen". */
- return 0;
-
- /* What we check for is that either the types are equal (needed for
- nameless types) or have the same name. This is ugly, and a more
- elegant solution should be devised (which would probably just push
- the ugliness into symbol reading unless we change the stabs format). */
- if (TYPE_TARGET_TYPE (fieldtype) == basetype)
- return 1;
-
- if (TYPE_NAME (basetype) != NULL
- && TYPE_NAME (TYPE_TARGET_TYPE (fieldtype)) != NULL
- && STREQ (TYPE_NAME (basetype),
- TYPE_NAME (TYPE_TARGET_TYPE (fieldtype))))
- return 1;
- return 0;
-}
-
-/* Compute the offset of the baseclass which is
- the INDEXth baseclass of class TYPE,
- for value at VALADDR (in host) at ADDRESS (in target).
- The result is the offset of the baseclass value relative
- to (the address of)(ARG) + OFFSET.
-
- -1 is returned on error. */
-
-int
-baseclass_offset (struct type *type, int index, char *valaddr,
- CORE_ADDR address)
-{
- struct type *basetype = TYPE_BASECLASS (type, index);
-
- if (BASETYPE_VIA_VIRTUAL (type, index))
- {
- /* Must hunt for the pointer to this virtual baseclass. */
- register int i, len = TYPE_NFIELDS (type);
- register int n_baseclasses = TYPE_N_BASECLASSES (type);
-
- /* First look for the virtual baseclass pointer
- in the fields. */
- for (i = n_baseclasses; i < len; i++)
- {
- if (vb_match (type, i, basetype))
- {
- CORE_ADDR addr
- = unpack_pointer (TYPE_FIELD_TYPE (type, i),
- valaddr + (TYPE_FIELD_BITPOS (type, i) / 8));
-
- return addr - (LONGEST) address;
- }
- }
- /* Not in the fields, so try looking through the baseclasses. */
- for (i = index + 1; i < n_baseclasses; i++)
- {
- int boffset =
- baseclass_offset (type, i, valaddr, address);
- if (boffset)
- return boffset;
- }
- /* Not found. */
- return -1;
- }
-
- /* Baseclass is easily computed. */
- return TYPE_BASECLASS_BITPOS (type, index) / 8;
-}
\f
/* Unpack a field FIELDNO of the specified TYPE, from the anonymous object at
VALADDR.
\f
/* Convert C numbers into newly allocated values */
-value_ptr
+struct value *
value_from_longest (struct type *type, register LONGEST num)
{
- register value_ptr val = allocate_value (type);
+ struct value *val = allocate_value (type);
register enum type_code code;
register int len;
retry:
/* Create a value representing a pointer of type TYPE to the address
ADDR. */
-value_ptr
+struct value *
value_from_pointer (struct type *type, CORE_ADDR addr)
{
- value_ptr val = allocate_value (type);
+ struct value *val = allocate_value (type);
store_typed_address (VALUE_CONTENTS_RAW (val), type, addr);
return val;
}
This is analogous to value_from_longest, which also does not
use inferior memory. String shall NOT contain embedded nulls. */
-value_ptr
+struct value *
value_from_string (char *ptr)
{
- value_ptr val;
+ struct value *val;
int len = strlen (ptr);
int lowbound = current_language->string_lower_bound;
struct type *rangetype =
return val;
}
-value_ptr
+struct value *
value_from_double (struct type *type, DOUBLEST num)
{
- register value_ptr val = allocate_value (type);
+ struct value *val = allocate_value (type);
struct type *base_type = check_typedef (type);
register enum type_code code = TYPE_CODE (base_type);
register int len = TYPE_LENGTH (base_type);
means returning pointer to where structure is vs. returning value). */
/* ARGSUSED */
-value_ptr
+struct value *
value_being_returned (struct type *valtype, char *retbuf, int struct_return)
{
- register value_ptr val;
+ struct value *val;
CORE_ADDR addr;
/* If this is not defined, just use EXTRACT_RETURN_VALUE instead. */
{
addr = EXTRACT_STRUCT_VALUE_ADDRESS (retbuf);
if (!addr)
- error ("Function return value unknown");
+ error ("Function return value unknown.");
return value_at (valtype, addr, NULL);
}
|| TYPE_LENGTH (value_type) == 8));
}
-#ifndef USE_STRUCT_CONVENTION
-#define USE_STRUCT_CONVENTION(gcc_p,type) generic_use_struct_convention (gcc_p, type)
-#endif
-
-
/* Return true if the function specified is using the structure returning
convention on this machine to return arguments, or 0 if it is using
the value returning convention. FUNCTION is the value representing
/* ARGSUSED */
int
-using_struct_return (value_ptr function, CORE_ADDR funcaddr,
+using_struct_return (struct value *function, CORE_ADDR funcaddr,
struct type *value_type, int gcc_p)
{
register enum type_code code = TYPE_CODE (value_type);
function wants to return. */
void
-set_return_value (value_ptr val)
+set_return_value (struct value *val)
{
struct type *type = check_typedef (VALUE_TYPE (val));
register enum type_code code = TYPE_CODE (type);
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