Address Class documentation.
This commit is contained in:
Kevin Buettner
parent
0d09fec6a5
commit
b5b0480a10
|
|
@ -1,3 +1,11 @@
|
|||
2002-10-17 Kevin Buettner <kevinb@redhat.com>
|
||||
|
||||
* gdbint.texinfo (Address Classes): New section.
|
||||
(Target Conditionals): Document ADDRESS_CLASS_NAME_TO_TYPE_FLAGS,
|
||||
ADDRESS_CLASS_NAME_TO_TYPE_FLAGS_P, ADDRESS_CLASS_TYPE_FLAGS,
|
||||
ADDRESS_CLASS_TYPE_FLAGS_P, ADDRESS_CLASS_TYPE_FLAGS_TO_NAME, and
|
||||
ADDRESS_CLASS_TYPE_FLAGS_TO_NAME_P.
|
||||
|
||||
2002-10-11 Klee Dienes <kdienes@apple.com>
|
||||
|
||||
* gdb.texinfo (Registers): Mention vector registers as well as
|
||||
|
|
|
|||
|
|
@ -2630,6 +2630,91 @@ This function may safely assume that @var{type} is either a pointer or a
|
|||
C@t{++} reference type.
|
||||
@end deftypefn
|
||||
|
||||
@section Address Classes
|
||||
@cindex address classes
|
||||
@cindex DW_AT_byte_size
|
||||
@cindex DW_AT_address_class
|
||||
|
||||
Sometimes information about different kinds of addresses is available
|
||||
via the debug information. For example, some programming environments
|
||||
define addresses of several different sizes. If the debug information
|
||||
distinguishes these kinds of address classes through either the size
|
||||
info (e.g, @code{DW_AT_byte_size} in @w{DWARF 2}) or through an explicit
|
||||
address class attribute (e.g, @code{DW_AT_address_class} in @w{DWARF 2}), the
|
||||
following macros should be defined in order to disambiguate these
|
||||
types within @value{GDBN} as well as provide the added information to
|
||||
a @value{GDBN} user when printing type expressions.
|
||||
|
||||
@deftypefn {Target Macro} int ADDRESS_CLASS_TYPE_FLAGS (int @var{byte_size}, int @var{dwarf2_addr_class})
|
||||
Returns the type flags needed to construct a pointer type whose size
|
||||
is @var{byte_size} and whose address class is @var{dwarf2_addr_class}.
|
||||
This function is normally called from within a symbol reader. See
|
||||
@file{dwarf2read.c}.
|
||||
@end deftypefn
|
||||
|
||||
@deftypefn {Target Macro} char *ADDRESS_CLASS_TYPE_FLAGS_TO_NAME (int @var{type_flags})
|
||||
Given the type flags representing an address class qualifier, return
|
||||
its name.
|
||||
@end deftypefn
|
||||
@deftypefn {Target Macro} int ADDRESS_CLASS_NAME_to_TYPE_FLAGS (int @var{name}, int *var{type_flags_ptr})
|
||||
Given an address qualifier name, set the @code{int} refererenced by @var{type_flags_ptr} to the type flags
|
||||
for that address class qualifier.
|
||||
@end deftypefn
|
||||
|
||||
Since the need for address classes is rather rare, none of
|
||||
the address class macros defined by default. Predicate
|
||||
macros are provided to detect when they are defined.
|
||||
|
||||
Consider a hypothetical architecture in which addresses are normally
|
||||
32-bits wide, but 16-bit addresses are also supported. Furthermore,
|
||||
suppose that the @w{DWARF 2} information for this architecture simply
|
||||
uses a @code{DW_AT_byte_size} value of 2 to indicate the use of one
|
||||
of these "short" pointers. The following functions could be defined
|
||||
to implement the address class macros:
|
||||
|
||||
@smallexample
|
||||
somearch_address_class_type_flags (int byte_size,
|
||||
int dwarf2_addr_class)
|
||||
{
|
||||
if (byte_size == 2)
|
||||
return TYPE_FLAG_ADDRESS_CLASS_1;
|
||||
else
|
||||
return 0;
|
||||
}
|
||||
|
||||
static char *
|
||||
somearch_address_class_type_flags_to_name (int type_flags)
|
||||
{
|
||||
if (type_flags & TYPE_FLAG_ADDRESS_CLASS_1)
|
||||
return "short";
|
||||
else
|
||||
return NULL;
|
||||
}
|
||||
|
||||
int
|
||||
somearch_address_class_name_to_type_flags (char *name,
|
||||
int *type_flags_ptr)
|
||||
{
|
||||
if (strcmp (name, "short") == 0)
|
||||
{
|
||||
*type_flags_ptr = TYPE_FLAG_ADDRESS_CLASS_1;
|
||||
return 1;
|
||||
}
|
||||
else
|
||||
return 0;
|
||||
}
|
||||
@end smallexample
|
||||
|
||||
The qualifier @code{@@short} is used in @value{GDBN}'s type expressions
|
||||
to indicate the presence of one of these "short" pointers. E.g, if
|
||||
the debug information indicates that @code{short_ptr_var} is one of these
|
||||
short pointers, @value{GDBN} might show the following behavior:
|
||||
|
||||
@smallexample
|
||||
(gdb) ptype short_ptr_var
|
||||
type = int * @@short
|
||||
@end smallexample
|
||||
|
||||
|
||||
@section Raw and Virtual Register Representations
|
||||
@cindex raw register representation
|
||||
|
|
@ -2857,6 +2942,49 @@ boundaries, the processor masks out these bits to generate the actual
|
|||
address of the instruction. ADDR_BITS_REMOVE should filter out these
|
||||
bits with an expression such as @code{((addr) & ~3)}.
|
||||
|
||||
@item ADDRESS_CLASS_NAME_TO_TYPE_FLAGS (@var{name}, @var{type_flags_ptr})
|
||||
@findex ADDRESS_CLASS_NAME_TO_TYPE_FLAGS
|
||||
If @var{name} is a valid address class qualifier name, set the @code{int}
|
||||
referenced by @var{type_flags_ptr} to the mask representing the qualifier
|
||||
and return 1. If @var{name} is not a valid address class qualifier name,
|
||||
return 0.
|
||||
|
||||
The value for @var{type_flags_ptr} should be one of
|
||||
@code{TYPE_FLAG_ADDRESS_CLASS_1}, @code{TYPE_FLAG_ADDRESS_CLASS_2}, or
|
||||
possibly some combination of these values or'd together.
|
||||
@xref{Target Architecture Definition, , Address Classes}.
|
||||
|
||||
@item ADDRESS_CLASS_NAME_TO_TYPE_FLAGS_P ()
|
||||
@findex ADDRESS_CLASS_NAME_TO_TYPE_FLAGS_P
|
||||
Predicate which indicates whether @code{ADDRESS_CLASS_NAME_TO_TYPE_FLAGS}
|
||||
has been defined.
|
||||
|
||||
@item ADDRESS_CLASS_TYPE_FLAGS (@var{byte_size}, @var{dwarf2_addr_class})
|
||||
@findex ADDRESS_CLASS_TYPE_FLAGS (@var{byte_size}, @var{dwarf2_addr_class})
|
||||
Given a pointers byte size (as described by the debug information) and
|
||||
the possible @code{DW_AT_address_class} value, return the type flags
|
||||
used by @value{GDBN} to represent this address class. The value
|
||||
returned should be one of @code{TYPE_FLAG_ADDRESS_CLASS_1},
|
||||
@code{TYPE_FLAG_ADDRESS_CLASS_2}, or possibly some combination of these
|
||||
values or'd together.
|
||||
@xref{Target Architecture Definition, , Address Classes}.
|
||||
|
||||
@item ADDRESS_CLASS_TYPE_FLAGS_P ()
|
||||
@findex ADDRESS_CLASS_TYPE_FLAGS_P
|
||||
Predicate which indicates whether @code{ADDRESS_CLASS_TYPE_FLAGS} has
|
||||
been defined.
|
||||
|
||||
@item ADDRESS_CLASS_TYPE_FLAGS_TO_NAME (@var{type_flags})
|
||||
@findex ADDRESS_CLASS_TYPE_FLAGS_TO_NAME
|
||||
Return the name of the address class qualifier associated with the type
|
||||
flags given by @var{type_flags}.
|
||||
|
||||
@item ADDRESS_CLASS_TYPE_FLAGS_TO_NAME_P ()
|
||||
@findex ADDRESS_CLASS_TYPE_FLAGS_TO_NAME_P
|
||||
Predicate which indicates whether @code{ADDRESS_CLASS_TYPE_FLAGS_TO_NAME} has
|
||||
been defined.
|
||||
@xref{Target Architecture Definition, , Address Classes}.
|
||||
|
||||
@item ADDRESS_TO_POINTER (@var{type}, @var{buf}, @var{addr})
|
||||
@findex ADDRESS_TO_POINTER
|
||||
Store in @var{buf} a pointer of type @var{type} representing the address
|
||||
|
|
|
|||
Loading…
Reference in New Issue