989 lines
29 KiB
C
989 lines
29 KiB
C
/* Garbage collection primitives for GNU C++.
|
||
Copyright (C) 1992, 1993 Free Software Foundation, Inc.
|
||
Contributed by Michael Tiemann (tiemann@cygnus.com)
|
||
|
||
This file is part of GNU CC.
|
||
|
||
GNU CC 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, or (at your option)
|
||
any later version.
|
||
|
||
GNU CC 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 GNU CC; see the file COPYING. If not, write to
|
||
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
|
||
|
||
|
||
#include "config.h"
|
||
#include "tree.h"
|
||
#include "cp-tree.h"
|
||
#include "flags.h"
|
||
|
||
#undef NULL
|
||
#define NULL 0
|
||
|
||
extern tree define_function ();
|
||
extern tree build_t_desc_overload ();
|
||
|
||
/* This is the function decl for the (pseudo-builtin) __gc_protect
|
||
function. Args are (class *value, int index); Returns value. */
|
||
tree gc_protect_fndecl;
|
||
|
||
/* This is the function decl for the (pseudo-builtin) __gc_unprotect
|
||
function. Args are (int index); void return. */
|
||
tree gc_unprotect_fndecl;
|
||
|
||
/* This is the function decl for the (pseudo-builtin) __gc_push
|
||
function. Args are (int length); void return. */
|
||
tree gc_push_fndecl;
|
||
|
||
/* This is the function decl for the (pseudo-builtin) __gc_pop
|
||
function. Args are void; void return. */
|
||
tree gc_pop_fndecl;
|
||
|
||
/* Special integers that are used to represent bits in gc-safe objects. */
|
||
tree gc_nonobject;
|
||
tree gc_visible;
|
||
tree gc_white;
|
||
tree gc_offwhite;
|
||
tree gc_grey;
|
||
tree gc_black;
|
||
|
||
/* in c-common.c */
|
||
extern tree combine_strings PROTO((tree));
|
||
|
||
/* Predicate that returns non-zero if TYPE needs some kind of
|
||
entry for the GC. Returns zero otherwise. */
|
||
int
|
||
type_needs_gc_entry (type)
|
||
tree type;
|
||
{
|
||
tree ttype = type;
|
||
|
||
if (! flag_gc || type == error_mark_node)
|
||
return 0;
|
||
|
||
/* Aggregate types need gc entries if any of their members
|
||
need gc entries. */
|
||
if (IS_AGGR_TYPE (type))
|
||
{
|
||
tree binfos;
|
||
tree fields = TYPE_FIELDS (type);
|
||
int i;
|
||
|
||
/* We don't care about certain pointers. Pointers
|
||
to virtual baseclasses are always up front. We also
|
||
cull out virtual function table pointers because it's
|
||
easy, and it simplifies the logic.*/
|
||
while (fields
|
||
&& (DECL_NAME (fields) == NULL_TREE
|
||
|| VFIELD_NAME_P (DECL_NAME (fields))
|
||
|| VBASE_NAME_P (DECL_NAME (fields))
|
||
|| !strcmp (IDENTIFIER_POINTER (DECL_NAME (fields)), "__bits")))
|
||
fields = TREE_CHAIN (fields);
|
||
|
||
while (fields)
|
||
{
|
||
if (type_needs_gc_entry (TREE_TYPE (fields)))
|
||
return 1;
|
||
fields = TREE_CHAIN (fields);
|
||
}
|
||
|
||
binfos = TYPE_BINFO_BASETYPES (type);
|
||
if (binfos)
|
||
for (i = TREE_VEC_LENGTH (binfos)-1; i >= 0; i--)
|
||
if (type_needs_gc_entry (BINFO_TYPE (TREE_VEC_ELT (binfos, i))))
|
||
return 1;
|
||
|
||
return 0;
|
||
}
|
||
|
||
while (TREE_CODE (ttype) == ARRAY_TYPE
|
||
&& TREE_CODE (TREE_TYPE (ttype)) == ARRAY_TYPE)
|
||
ttype = TREE_TYPE (ttype);
|
||
if ((TREE_CODE (ttype) == POINTER_TYPE
|
||
|| TREE_CODE (ttype) == ARRAY_TYPE
|
||
|| TREE_CODE (ttype) == REFERENCE_TYPE)
|
||
&& IS_AGGR_TYPE (TREE_TYPE (ttype))
|
||
&& CLASSTYPE_DOSSIER (TREE_TYPE (ttype)))
|
||
return 1;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Predicate that returns non-zero iff FROM is safe from the GC.
|
||
|
||
If TO is nonzero, it means we know that FROM is being stored
|
||
in TO, which make make it safe. */
|
||
int
|
||
value_safe_from_gc (to, from)
|
||
tree to, from;
|
||
{
|
||
/* First, return non-zero for easy cases: parameters,
|
||
static variables. */
|
||
if (TREE_CODE (from) == PARM_DECL
|
||
|| (TREE_CODE (from) == VAR_DECL
|
||
&& TREE_STATIC (from)))
|
||
return 1;
|
||
|
||
/* If something has its address taken, it cannot be
|
||
in the heap, so it doesn't need to be protected. */
|
||
if (TREE_CODE (from) == ADDR_EXPR || TREE_REFERENCE_EXPR (from))
|
||
return 1;
|
||
|
||
/* If we are storing into a static variable, then what
|
||
we store will be safe from the gc. */
|
||
if (to && TREE_CODE (to) == VAR_DECL
|
||
&& TREE_STATIC (to))
|
||
return 1;
|
||
|
||
/* Now recurse on structure of FROM. */
|
||
switch (TREE_CODE (from))
|
||
{
|
||
case COMPONENT_REF:
|
||
/* These guys are special, and safe. */
|
||
if (TREE_CODE (TREE_OPERAND (from, 1)) == FIELD_DECL
|
||
&& (VFIELD_NAME_P (DECL_NAME (TREE_OPERAND (from, 1)))
|
||
|| VBASE_NAME_P (DECL_NAME (TREE_OPERAND (from, 1)))))
|
||
return 1;
|
||
/* fall through... */
|
||
case NOP_EXPR:
|
||
case CONVERT_EXPR:
|
||
case NON_LVALUE_EXPR:
|
||
case WITH_CLEANUP_EXPR:
|
||
case SAVE_EXPR:
|
||
case PREDECREMENT_EXPR:
|
||
case PREINCREMENT_EXPR:
|
||
case POSTDECREMENT_EXPR:
|
||
case POSTINCREMENT_EXPR:
|
||
if (value_safe_from_gc (to, TREE_OPERAND (from, 0)))
|
||
return 1;
|
||
break;
|
||
|
||
case VAR_DECL:
|
||
case PARM_DECL:
|
||
/* We can safely pass these things as parameters to functions. */
|
||
if (to == 0)
|
||
return 1;
|
||
|
||
case ARRAY_REF:
|
||
case INDIRECT_REF:
|
||
case RESULT_DECL:
|
||
case OFFSET_REF:
|
||
case CALL_EXPR:
|
||
case METHOD_CALL_EXPR:
|
||
break;
|
||
|
||
case COMPOUND_EXPR:
|
||
case TARGET_EXPR:
|
||
if (value_safe_from_gc (to, TREE_OPERAND (from, 1)))
|
||
return 1;
|
||
break;
|
||
|
||
case COND_EXPR:
|
||
if (value_safe_from_gc (to, TREE_OPERAND (from, 1))
|
||
&& value_safe_from_gc (to, TREE_OPERAND (from, 2)))
|
||
return 1;
|
||
break;
|
||
|
||
case PLUS_EXPR:
|
||
case MINUS_EXPR:
|
||
if ((type_needs_gc_entry (TREE_TYPE (TREE_OPERAND (from, 0)))
|
||
|| value_safe_from_gc (to, TREE_OPERAND (from, 0)))
|
||
&& (type_needs_gc_entry (TREE_TYPE (TREE_OPERAND (from, 1))) == 0
|
||
|| value_safe_from_gc (to, TREE_OPERAND (from, 1))))
|
||
return 1;
|
||
break;
|
||
|
||
case RTL_EXPR:
|
||
/* Every time we build an RTL_EXPR in the front-end, we must
|
||
ensure that everything in it is safe from the garbage collector.
|
||
??? This has only been done for `build_new'. */
|
||
return 1;
|
||
|
||
default:
|
||
my_friendly_abort (41);
|
||
}
|
||
|
||
if (to == 0)
|
||
return 0;
|
||
|
||
/* FROM wasn't safe. But other properties of TO might make it safe. */
|
||
switch (TREE_CODE (to))
|
||
{
|
||
case VAR_DECL:
|
||
case PARM_DECL:
|
||
/* We already culled out static VAR_DECLs above. */
|
||
return 0;
|
||
|
||
case COMPONENT_REF:
|
||
/* These guys are special, and safe. */
|
||
if (TREE_CODE (TREE_OPERAND (to, 1)) == FIELD_DECL
|
||
&& (VFIELD_NAME_P (DECL_NAME (TREE_OPERAND (to, 1)))
|
||
|| VBASE_NAME_P (DECL_NAME (TREE_OPERAND (to, 1)))))
|
||
return 1;
|
||
/* fall through... */
|
||
|
||
case NOP_EXPR:
|
||
case NON_LVALUE_EXPR:
|
||
case WITH_CLEANUP_EXPR:
|
||
case SAVE_EXPR:
|
||
case PREDECREMENT_EXPR:
|
||
case PREINCREMENT_EXPR:
|
||
case POSTDECREMENT_EXPR:
|
||
case POSTINCREMENT_EXPR:
|
||
return value_safe_from_gc (TREE_OPERAND (to, 0), from);
|
||
|
||
case COMPOUND_EXPR:
|
||
case TARGET_EXPR:
|
||
return value_safe_from_gc (TREE_OPERAND (to, 1), from);
|
||
|
||
case COND_EXPR:
|
||
return (value_safe_from_gc (TREE_OPERAND (to, 1), from)
|
||
&& value_safe_from_gc (TREE_OPERAND (to, 2), from));
|
||
|
||
case INDIRECT_REF:
|
||
case ARRAY_REF:
|
||
/* This used to be 0, but our current restricted model
|
||
allows this to be 1. We'll never get arrays this way. */
|
||
return 1;
|
||
|
||
default:
|
||
my_friendly_abort (42);
|
||
}
|
||
|
||
/* Catch-all case is that TO/FROM is not safe. */
|
||
return 0;
|
||
}
|
||
|
||
/* Function to build a static GC entry for DECL. TYPE is DECL's type.
|
||
|
||
For objects of type `class *', this is just an entry in the
|
||
static vector __PTR_LIST__.
|
||
|
||
For objects of type `class[]', this requires building an entry
|
||
in the static vector __ARR_LIST__.
|
||
|
||
For aggregates, this records all fields of type `class *'
|
||
and `class[]' in the respective lists above. */
|
||
void
|
||
build_static_gc_entry (decl, type)
|
||
tree decl;
|
||
tree type;
|
||
{
|
||
/* Now, figure out what sort of entry to build. */
|
||
if (TREE_CODE (type) == POINTER_TYPE
|
||
|| TREE_CODE (type) == REFERENCE_TYPE)
|
||
assemble_gc_entry (IDENTIFIER_POINTER (DECL_NAME (decl)));
|
||
else if (TREE_CODE (type) == RECORD_TYPE)
|
||
{
|
||
tree ref = get_temp_name (build_reference_type (type), 1);
|
||
DECL_INITIAL (ref) = build1 (ADDR_EXPR, TREE_TYPE (ref), decl);
|
||
TREE_CONSTANT (DECL_INITIAL (ref)) = 1;
|
||
finish_decl (ref, DECL_INITIAL (ref), 0, 0);
|
||
}
|
||
else
|
||
{
|
||
/* Not yet implemented.
|
||
|
||
Cons up a static variable that holds address and length info
|
||
and add that to ___ARR_LIST__. */
|
||
my_friendly_abort (43);
|
||
}
|
||
}
|
||
|
||
/* Protect FROM from the GC, assuming FROM is going to be
|
||
stored into TO. We handle three cases for TO here:
|
||
|
||
case 1: TO is a stack variable.
|
||
case 2: TO is zero (which means it is a parameter).
|
||
case 3: TO is a return value. */
|
||
|
||
tree
|
||
protect_value_from_gc (to, from)
|
||
tree to, from;
|
||
{
|
||
if (to == 0)
|
||
{
|
||
tree cleanup;
|
||
|
||
to = get_temp_regvar (TREE_TYPE (from), from);
|
||
|
||
/* Convert from integer to list form since we'll use it twice. */
|
||
DECL_GC_OFFSET (to) = build_tree_list (NULL_TREE, DECL_GC_OFFSET (to));
|
||
cleanup = build_function_call (gc_unprotect_fndecl,
|
||
DECL_GC_OFFSET (to));
|
||
|
||
if (! expand_decl_cleanup (to, cleanup))
|
||
{
|
||
compiler_error ("cannot unprotect parameter in this scope");
|
||
return error_mark_node;
|
||
}
|
||
}
|
||
|
||
/* Should never need to protect a value that's headed for static storage. */
|
||
if (TREE_STATIC (to))
|
||
my_friendly_abort (44);
|
||
|
||
switch (TREE_CODE (to))
|
||
{
|
||
case COMPONENT_REF:
|
||
case INDIRECT_REF:
|
||
return protect_value_from_gc (TREE_OPERAND (to, 0), from);
|
||
|
||
case VAR_DECL:
|
||
case PARM_DECL:
|
||
{
|
||
tree rval;
|
||
if (DECL_GC_OFFSET (to) == NULL_TREE)
|
||
{
|
||
/* Because of a cast or a conversion, we might stick
|
||
a value into a variable that would not normally
|
||
have a GC entry. */
|
||
DECL_GC_OFFSET (to) = size_int (++current_function_obstack_index);
|
||
}
|
||
|
||
if (TREE_CODE (DECL_GC_OFFSET (to)) != TREE_LIST)
|
||
{
|
||
DECL_GC_OFFSET (to)
|
||
= build_tree_list (NULL_TREE, DECL_GC_OFFSET (to));
|
||
}
|
||
|
||
current_function_obstack_usage = 1;
|
||
rval = build_function_call (gc_protect_fndecl,
|
||
tree_cons (NULL_TREE, from,
|
||
DECL_GC_OFFSET (to)));
|
||
TREE_TYPE (rval) = TREE_TYPE (from);
|
||
return rval;
|
||
}
|
||
}
|
||
|
||
/* If we fall through the switch, assume we lost. */
|
||
my_friendly_abort (45);
|
||
/* NOTREACHED */
|
||
return NULL_TREE;
|
||
}
|
||
|
||
/* Given the expression EXP of type `class *', return the head
|
||
of the object pointed to by EXP. */
|
||
tree
|
||
build_headof (exp)
|
||
tree exp;
|
||
{
|
||
tree type = TREE_TYPE (exp);
|
||
tree vptr, offset;
|
||
|
||
if (TREE_CODE (type) != POINTER_TYPE)
|
||
{
|
||
error ("`headof' applied to non-pointer type");
|
||
return error_mark_node;
|
||
}
|
||
|
||
if (flag_vtable_thunks)
|
||
abort();
|
||
|
||
vptr = build1 (INDIRECT_REF, TYPE_POINTER_TO (vtable_entry_type), exp);
|
||
offset = build_component_ref (build_array_ref (vptr, integer_one_node),
|
||
get_identifier (VTABLE_DELTA_NAME),
|
||
NULL_TREE, 0);
|
||
return build (PLUS_EXPR, class_star_type_node, exp,
|
||
convert (integer_type_node, offset));
|
||
}
|
||
|
||
/* Given the expression EXP of type `class *', return the
|
||
type descriptor for the object pointed to by EXP. */
|
||
tree
|
||
build_classof (exp)
|
||
tree exp;
|
||
{
|
||
tree type = TREE_TYPE (exp);
|
||
tree vptr;
|
||
tree t_desc_entry;
|
||
|
||
if (TREE_CODE (type) != POINTER_TYPE)
|
||
{
|
||
error ("`classof' applied to non-pointer type");
|
||
return error_mark_node;
|
||
}
|
||
|
||
vptr = build1 (INDIRECT_REF, TYPE_POINTER_TO (vtable_entry_type), exp);
|
||
t_desc_entry = build_component_ref (build_array_ref (vptr, integer_one_node),
|
||
get_identifier (VTABLE_PFN_NAME),
|
||
NULL_TREE, 0);
|
||
TREE_TYPE (t_desc_entry) = TYPE_POINTER_TO (__t_desc_type_node);
|
||
return t_desc_entry;
|
||
}
|
||
|
||
/* Return the Type_info node associated with the expression EXP. If EXP is
|
||
a reference to a polymorphic class, return the dynamic type; otherwise
|
||
return the static type of the expression. */
|
||
tree
|
||
build_typeid (exp)
|
||
tree exp;
|
||
{
|
||
tree type;
|
||
|
||
if (exp == error_mark_node)
|
||
return error_mark_node;
|
||
|
||
type = TREE_TYPE (exp);
|
||
|
||
/* if b is an instance of B, typeid(b) == typeid(B). Do this before
|
||
reference trickiness. */
|
||
if (TREE_CODE (exp) == VAR_DECL && TREE_CODE (type) == RECORD_TYPE)
|
||
return get_typeid (type);
|
||
|
||
/* Apply trivial conversion T -> T& for dereferenced ptrs. */
|
||
if (TREE_CODE (type) == RECORD_TYPE)
|
||
type = build_reference_type (type);
|
||
|
||
/* If exp is a reference to polymorphic type, get the real Type_info. */
|
||
if (TREE_CODE (type) == REFERENCE_TYPE && TYPE_VIRTUAL_P (TREE_TYPE (type)))
|
||
{
|
||
/* build reference to Type_info from vtable. */
|
||
|
||
sorry ("finding Type_info for an object");
|
||
return error_mark_node;
|
||
}
|
||
|
||
/* otherwise return the Type_info for the static type of the expr. */
|
||
return get_typeid (type);
|
||
}
|
||
|
||
/* Return the Type_info object for TYPE, creating it if necessary. */
|
||
tree
|
||
get_typeid (type)
|
||
tree type;
|
||
{
|
||
if (type == error_mark_node)
|
||
return error_mark_node;
|
||
|
||
/* Is it useful (and/or correct) to have different typeids for `T &'
|
||
and `T'? */
|
||
if (TREE_CODE (type) == REFERENCE_TYPE)
|
||
type = TREE_TYPE (type);
|
||
|
||
/* build reference to static Type_info */
|
||
#if 1
|
||
sorry ("finding Type_info for a type");
|
||
return error_mark_node;
|
||
#else
|
||
register tree t = TYPE_TINFO (type);
|
||
|
||
if (t)
|
||
return t;
|
||
|
||
/* ... */
|
||
|
||
#endif
|
||
}
|
||
|
||
/* Execute a dynamic cast, as described in section 5.2.6 of the 9/93 working
|
||
paper. */
|
||
tree
|
||
build_dynamic_cast (type, expr)
|
||
tree type, expr;
|
||
{
|
||
enum tree_code tc = TREE_CODE (type);
|
||
tree exprtype = TREE_TYPE (expr);
|
||
enum tree_code ec = TREE_CODE (exprtype);
|
||
tree retval;
|
||
|
||
if (type == error_mark_node || expr == error_mark_node)
|
||
return error_mark_node;
|
||
|
||
switch (tc)
|
||
{
|
||
case POINTER_TYPE:
|
||
if (TREE_TYPE (type) == void_type_node)
|
||
break;
|
||
/* else fall through */
|
||
case REFERENCE_TYPE:
|
||
if (TREE_CODE (TREE_TYPE (type)) == RECORD_TYPE
|
||
&& TYPE_SIZE (TREE_TYPE (type)) != NULL_TREE)
|
||
break;
|
||
/* else fall through */
|
||
default:
|
||
cp_error ("`%#T' is not a valid type argument for dynamic_cast", type);
|
||
error ("(must be either pointer or reference to defined class or void *)");
|
||
return error_mark_node;
|
||
}
|
||
|
||
/* Apply trivial conversion T -> T& for dereferenced ptrs. */
|
||
if (ec == RECORD_TYPE)
|
||
{
|
||
exprtype = build_reference_type (exprtype);
|
||
ec = REFERENCE_TYPE;
|
||
}
|
||
|
||
/* the TREE_CODE of exprtype must match that of type. */
|
||
if (ec != tc)
|
||
{
|
||
cp_error ("`%E' (of type `%#T') fails to be of %s type", expr, exprtype,
|
||
tc == POINTER_TYPE ? "pointer" : "reference");
|
||
return error_mark_node;
|
||
}
|
||
|
||
/* If *type is an unambiguous accessible base class of *exprtype,
|
||
convert statically. */
|
||
{
|
||
int distance;
|
||
tree path;
|
||
|
||
distance = get_base_distance (TREE_TYPE (type), TREE_TYPE (exprtype), 1,
|
||
&path);
|
||
if (distance >= 0)
|
||
return build_vbase_path (PLUS_EXPR, type, expr, path, 0);
|
||
}
|
||
|
||
/* Otherwise *exprtype must be a polymorphic class (have a vtbl). */
|
||
if (TYPE_VIRTUAL_P (TREE_TYPE (exprtype)))
|
||
{
|
||
/* if TYPE is `void *', return pointer to complete object. */
|
||
if (tc == POINTER_TYPE && TREE_TYPE (type) == void_type_node)
|
||
{
|
||
/* if b is an object, dynamic_cast<void *>(&b) == (void *)&b. */
|
||
if (TREE_CODE (expr) == ADDR_EXPR
|
||
&& TREE_CODE (TREE_OPERAND (expr, 0)) == VAR_DECL
|
||
&& TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == RECORD_TYPE)
|
||
return build1 (NOP_EXPR, type, expr);
|
||
|
||
sorry ("finding pointer to complete object");
|
||
return build1 (NOP_EXPR, type, expr);
|
||
}
|
||
else
|
||
{
|
||
tree retval;
|
||
|
||
/* If we got here, we can't convert statically. Therefore,
|
||
dynamic_cast<D&>(b) (b an object) cannot succeed. */
|
||
if (ec == REFERENCE_TYPE)
|
||
{
|
||
if (TREE_CODE (expr) == VAR_DECL
|
||
&& TREE_CODE (TREE_TYPE (expr)) == RECORD_TYPE)
|
||
{
|
||
cp_warning ("dynamic_cast of `%#D' to `%#T' can never succeed",
|
||
expr, type);
|
||
/* cplus_expand_throw (Bad_cast_node); */
|
||
sorry ("throwing Bad_cast");
|
||
return error_mark_node;
|
||
}
|
||
}
|
||
/* Ditto for dynamic_cast<D*>(&b). */
|
||
else if (TREE_CODE (expr) == ADDR_EXPR)
|
||
{
|
||
tree op = TREE_OPERAND (expr, 0);
|
||
if (TREE_CODE (op) == VAR_DECL
|
||
&& TREE_CODE (TREE_TYPE (op)) == RECORD_TYPE)
|
||
{
|
||
cp_warning ("dynamic_cast of `%E' to `%#T' can never succeed",
|
||
expr, type);
|
||
retval = build_int_2 (0, 0);
|
||
TREE_TYPE (retval) = type;
|
||
return retval;
|
||
}
|
||
}
|
||
/* Build run-time conversion. */
|
||
sorry ("run-time type conversion");
|
||
retval = build_int_2 (0, 0);
|
||
TREE_TYPE (retval) = type;
|
||
return retval;
|
||
}
|
||
}
|
||
|
||
cp_error ("cannot dynamic_cast `%E' (of type `%#T') to type `%#T'",
|
||
expr, exprtype, type);
|
||
return error_mark_node;
|
||
}
|
||
|
||
/* Build and initialize various sorts of descriptors. Every descriptor
|
||
node has a name associated with it (the name created by mangling).
|
||
For this reason, we use the identifier as our access to the __*_desc
|
||
nodes, instead of sticking them directly in the types. Otherwise we
|
||
would burden all built-in types (and pointer types) with slots that
|
||
we don't necessarily want to use.
|
||
|
||
For each descriptor we build, we build a variable that contains
|
||
the descriptor's information. When we need this info at runtime,
|
||
all we need is access to these variables.
|
||
|
||
Note: these constructors always return the address of the descriptor
|
||
info, since that is simplest for their mutual interaction. */
|
||
|
||
static tree
|
||
build_generic_desc (decl, elems)
|
||
tree decl;
|
||
tree elems;
|
||
{
|
||
tree init = build (CONSTRUCTOR, TREE_TYPE (decl), NULL_TREE, elems);
|
||
TREE_CONSTANT (init) = 1;
|
||
TREE_STATIC (init) = 1;
|
||
TREE_READONLY (init) = 1;
|
||
|
||
DECL_INITIAL (decl) = init;
|
||
TREE_STATIC (decl) = 1;
|
||
layout_decl (decl, 0);
|
||
finish_decl (decl, init, 0, 0);
|
||
|
||
return IDENTIFIER_AS_DESC (DECL_NAME (decl));
|
||
}
|
||
|
||
/* Build an initializer for a __t_desc node. So that we can take advantage
|
||
of recursion, we accept NULL for TYPE.
|
||
DEFINITION is greater than zero iff we must define the type descriptor
|
||
(as opposed to merely referencing it). 1 means treat according to
|
||
#pragma interface/#pragma implementation rules. 2 means define as
|
||
global and public, no matter what. */
|
||
tree
|
||
build_t_desc (type, definition)
|
||
tree type;
|
||
int definition;
|
||
{
|
||
tree tdecl;
|
||
tree tname, name_string;
|
||
tree elems, fields;
|
||
tree parents, vbases, offsets, ivars, methods, target_type;
|
||
int method_count = 0, field_count = 0;
|
||
|
||
if (type == NULL_TREE)
|
||
return NULL_TREE;
|
||
|
||
tname = build_t_desc_overload (type);
|
||
if (IDENTIFIER_AS_DESC (tname)
|
||
&& (!definition || TREE_ASM_WRITTEN (IDENTIFIER_AS_DESC (tname))))
|
||
return IDENTIFIER_AS_DESC (tname);
|
||
|
||
tdecl = lookup_name (tname, 0);
|
||
if (tdecl == NULL_TREE)
|
||
{
|
||
tdecl = build_decl (VAR_DECL, tname, __t_desc_type_node);
|
||
DECL_EXTERNAL (tdecl) = 1;
|
||
TREE_PUBLIC (tdecl) = 1;
|
||
tdecl = pushdecl_top_level (tdecl);
|
||
}
|
||
/* If we previously defined it, return the defined result. */
|
||
else if (definition && DECL_INITIAL (tdecl))
|
||
return IDENTIFIER_AS_DESC (tname);
|
||
|
||
if (definition)
|
||
{
|
||
tree taggr = type;
|
||
/* Let T* and T& be written only when T is written (if T is an aggr).
|
||
We do this for const, but not for volatile, since volatile
|
||
is rare and const is not. */
|
||
if (!TYPE_VOLATILE (taggr)
|
||
&& (TREE_CODE (taggr) == POINTER_TYPE
|
||
|| TREE_CODE (taggr) == REFERENCE_TYPE)
|
||
&& IS_AGGR_TYPE (TREE_TYPE (taggr)))
|
||
taggr = TREE_TYPE (taggr);
|
||
|
||
/* If we know that we don't need to write out this type's
|
||
vtable, then don't write out it's dossier. Somebody
|
||
else will take care of that. */
|
||
if (IS_AGGR_TYPE (taggr) && CLASSTYPE_VFIELD (taggr))
|
||
{
|
||
if (CLASSTYPE_VTABLE_NEEDS_WRITING (taggr))
|
||
{
|
||
TREE_PUBLIC (tdecl) = ! CLASSTYPE_INTERFACE_ONLY (taggr)
|
||
&& CLASSTYPE_INTERFACE_KNOWN (taggr);
|
||
TREE_STATIC (tdecl) = 1;
|
||
DECL_EXTERNAL (tdecl) = 0;
|
||
}
|
||
else
|
||
{
|
||
if (write_virtuals != 0)
|
||
TREE_PUBLIC (tdecl) = 1;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
DECL_EXTERNAL (tdecl) = 0;
|
||
TREE_STATIC (tdecl) = 1;
|
||
TREE_PUBLIC (tdecl) = (definition > 1);
|
||
}
|
||
}
|
||
SET_IDENTIFIER_AS_DESC (tname, build_unary_op (ADDR_EXPR, tdecl, 0));
|
||
if (!definition || DECL_EXTERNAL (tdecl))
|
||
{
|
||
/* That's it! */
|
||
finish_decl (tdecl, 0, 0, 0);
|
||
return IDENTIFIER_AS_DESC (tname);
|
||
}
|
||
|
||
/* Show that we are defining the t_desc for this type. */
|
||
DECL_INITIAL (tdecl) = error_mark_node;
|
||
|
||
parents = build_tree_list (NULL_TREE, integer_zero_node);
|
||
vbases = build_tree_list (NULL_TREE, integer_zero_node);
|
||
offsets = build_tree_list (NULL_TREE, integer_zero_node);
|
||
methods = NULL_TREE;
|
||
ivars = NULL_TREE;
|
||
|
||
if (TYPE_LANG_SPECIFIC (type))
|
||
{
|
||
int i = CLASSTYPE_N_BASECLASSES (type);
|
||
tree method_vec = CLASSTYPE_METHOD_VEC (type);
|
||
tree *meth, *end;
|
||
tree binfos = TYPE_BINFO_BASETYPES (type);
|
||
tree vb = CLASSTYPE_VBASECLASSES (type);
|
||
|
||
while (--i >= 0)
|
||
parents = tree_cons (NULL_TREE, build_t_desc (BINFO_TYPE (TREE_VEC_ELT (binfos, i)), 0), parents);
|
||
|
||
while (vb)
|
||
{
|
||
vbases = tree_cons (NULL_TREE, build_t_desc (BINFO_TYPE (vb), 0), vbases);
|
||
offsets = tree_cons (NULL_TREE, BINFO_OFFSET (vb), offsets);
|
||
vb = TREE_CHAIN (vb);
|
||
}
|
||
|
||
if (method_vec)
|
||
for (meth = TREE_VEC_END (method_vec),
|
||
end = &TREE_VEC_ELT (method_vec, 0); meth-- != end; )
|
||
if (*meth)
|
||
{
|
||
methods = tree_cons (NULL_TREE, build_m_desc (*meth), methods);
|
||
method_count++;
|
||
}
|
||
}
|
||
|
||
if (IS_AGGR_TYPE (type))
|
||
{
|
||
for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
|
||
if (TREE_CODE (fields) == FIELD_DECL
|
||
|| TREE_CODE (fields) == VAR_DECL)
|
||
{
|
||
ivars = tree_cons (NULL_TREE, build_i_desc (fields), ivars);
|
||
field_count++;
|
||
}
|
||
ivars = nreverse (ivars);
|
||
}
|
||
|
||
parents = finish_table (0, TYPE_POINTER_TO (__t_desc_type_node), parents, 0);
|
||
vbases = finish_table (0, TYPE_POINTER_TO (__t_desc_type_node), vbases, 0);
|
||
offsets = finish_table (0, integer_type_node, offsets, 0);
|
||
if (methods == NULL_TREE)
|
||
methods = null_pointer_node;
|
||
else
|
||
methods = build_unary_op (ADDR_EXPR,
|
||
finish_table (0, __m_desc_type_node, methods, 0),
|
||
0);
|
||
if (ivars == NULL_TREE)
|
||
ivars = null_pointer_node;
|
||
else
|
||
ivars = build_unary_op (ADDR_EXPR,
|
||
finish_table (0, __i_desc_type_node, ivars, 0),
|
||
0);
|
||
if (TREE_TYPE (type))
|
||
target_type = build_t_desc (TREE_TYPE (type), definition);
|
||
else
|
||
target_type = integer_zero_node;
|
||
|
||
name_string = combine_strings (build_string (IDENTIFIER_LENGTH (tname)+1, IDENTIFIER_POINTER (tname)));
|
||
|
||
elems = tree_cons (NULL_TREE, build_unary_op (ADDR_EXPR, name_string, 0),
|
||
tree_cons (NULL_TREE,
|
||
TYPE_SIZE(type)? size_in_bytes(type) : integer_zero_node,
|
||
/* really should use bitfield initialization here. */
|
||
tree_cons (NULL_TREE, integer_zero_node,
|
||
tree_cons (NULL_TREE, target_type,
|
||
tree_cons (NULL_TREE, build_int_2 (field_count, 2),
|
||
tree_cons (NULL_TREE, build_int_2 (method_count, 2),
|
||
tree_cons (NULL_TREE, ivars,
|
||
tree_cons (NULL_TREE, methods,
|
||
tree_cons (NULL_TREE, build_unary_op (ADDR_EXPR, parents, 0),
|
||
tree_cons (NULL_TREE, build_unary_op (ADDR_EXPR, vbases, 0),
|
||
build_tree_list (NULL_TREE, build_unary_op (ADDR_EXPR, offsets, 0))))))))))));
|
||
return build_generic_desc (tdecl, elems);
|
||
}
|
||
|
||
/* Build an initializer for a __i_desc node. */
|
||
tree
|
||
build_i_desc (decl)
|
||
tree decl;
|
||
{
|
||
tree elems, name_string;
|
||
tree taggr;
|
||
|
||
name_string = DECL_NAME (decl);
|
||
name_string = combine_strings (build_string (IDENTIFIER_LENGTH (name_string)+1, IDENTIFIER_POINTER (name_string)));
|
||
|
||
/* Now decide whether this ivar should cause it's type to get
|
||
def'd or ref'd in this file. If the type we are looking at
|
||
has a proxy definition, we look at the proxy (i.e., a
|
||
`foo *' is equivalent to a `foo'). */
|
||
taggr = TREE_TYPE (decl);
|
||
|
||
if ((TREE_CODE (taggr) == POINTER_TYPE
|
||
|| TREE_CODE (taggr) == REFERENCE_TYPE)
|
||
&& TYPE_VOLATILE (taggr) == 0)
|
||
taggr = TREE_TYPE (taggr);
|
||
|
||
elems = tree_cons (NULL_TREE, build_unary_op (ADDR_EXPR, name_string, 0),
|
||
tree_cons (NULL_TREE, DECL_FIELD_BITPOS (decl),
|
||
build_tree_list (NULL_TREE, build_t_desc (TREE_TYPE (decl),
|
||
! IS_AGGR_TYPE (taggr)))));
|
||
taggr = build (CONSTRUCTOR, __i_desc_type_node, NULL_TREE, elems);
|
||
TREE_CONSTANT (taggr) = 1;
|
||
TREE_STATIC (taggr) = 1;
|
||
TREE_READONLY (taggr) = 1;
|
||
return taggr;
|
||
}
|
||
|
||
/* Build an initializer for a __m_desc node. */
|
||
tree
|
||
build_m_desc (decl)
|
||
tree decl;
|
||
{
|
||
tree taggr, elems, name_string;
|
||
tree parm_count, req_count, vindex, vcontext;
|
||
tree parms;
|
||
int p_count, r_count;
|
||
tree parm_types = NULL_TREE;
|
||
|
||
for (parms = TYPE_ARG_TYPES (TREE_TYPE (decl)), p_count = 0, r_count = 0;
|
||
parms != NULL_TREE; parms = TREE_CHAIN (parms), p_count++)
|
||
{
|
||
taggr = TREE_VALUE (parms);
|
||
if ((TREE_CODE (taggr) == POINTER_TYPE
|
||
|| TREE_CODE (taggr) == REFERENCE_TYPE)
|
||
&& TYPE_VOLATILE (taggr) == 0)
|
||
taggr = TREE_TYPE (taggr);
|
||
|
||
parm_types = tree_cons (NULL_TREE, build_t_desc (TREE_VALUE (parms),
|
||
! IS_AGGR_TYPE (taggr)),
|
||
parm_types);
|
||
if (TREE_PURPOSE (parms) == NULL_TREE)
|
||
r_count++;
|
||
}
|
||
|
||
parm_types = finish_table (0, TYPE_POINTER_TO (__t_desc_type_node),
|
||
nreverse (parm_types), 0);
|
||
parm_count = build_int_2 (p_count, 0);
|
||
req_count = build_int_2 (r_count, 0);
|
||
|
||
if (DECL_VINDEX (decl))
|
||
vindex = DECL_VINDEX (decl);
|
||
else
|
||
vindex = integer_zero_node;
|
||
if (DECL_CONTEXT (decl)
|
||
&& TREE_CODE_CLASS (TREE_CODE (DECL_CONTEXT (decl))) == 't')
|
||
vcontext = build_t_desc (DECL_CONTEXT (decl), 0);
|
||
else
|
||
vcontext = integer_zero_node;
|
||
name_string = DECL_NAME (decl);
|
||
if (name_string == NULL)
|
||
name_string = DECL_ASSEMBLER_NAME (decl);
|
||
name_string = combine_strings (build_string (IDENTIFIER_LENGTH (name_string)+1, IDENTIFIER_POINTER (name_string)));
|
||
|
||
/* Now decide whether the return type of this mvar
|
||
should cause it's type to get def'd or ref'd in this file.
|
||
If the type we are looking at has a proxy definition,
|
||
we look at the proxy (i.e., a `foo *' is equivalent to a `foo'). */
|
||
taggr = TREE_TYPE (TREE_TYPE (decl));
|
||
|
||
if ((TREE_CODE (taggr) == POINTER_TYPE
|
||
|| TREE_CODE (taggr) == REFERENCE_TYPE)
|
||
&& TYPE_VOLATILE (taggr) == 0)
|
||
taggr = TREE_TYPE (taggr);
|
||
|
||
elems = tree_cons (NULL_TREE, build_unary_op (ADDR_EXPR, name_string, 0),
|
||
tree_cons (NULL_TREE, vindex,
|
||
tree_cons (NULL_TREE, vcontext,
|
||
tree_cons (NULL_TREE, build_t_desc (TREE_TYPE (TREE_TYPE (decl)),
|
||
! IS_AGGR_TYPE (taggr)),
|
||
tree_cons (NULL_TREE, build_c_cast (TYPE_POINTER_TO (default_function_type), build_unary_op (ADDR_EXPR, decl, 0)),
|
||
tree_cons (NULL_TREE, parm_count,
|
||
tree_cons (NULL_TREE, req_count,
|
||
build_tree_list (NULL_TREE, build_unary_op (ADDR_EXPR, parm_types, 0)))))))));
|
||
|
||
taggr = build (CONSTRUCTOR, __m_desc_type_node, NULL_TREE, elems);
|
||
TREE_CONSTANT (taggr) = 1;
|
||
TREE_STATIC (taggr) = 1;
|
||
TREE_READONLY (taggr) = 1;
|
||
return taggr;
|
||
}
|
||
|
||
/* Conditionally emit code to set up an unwind-protect for the
|
||
garbage collector. If this function doesn't do anything that involves
|
||
the garbage collector, then do nothing. Otherwise, call __gc_push
|
||
at the beginning and __gc_pop at the end.
|
||
|
||
NOTE! The __gc_pop function must operate transparently, since
|
||
it comes where the logical return label lies. This means that
|
||
at runtime *it* must preserve any return value registers. */
|
||
|
||
void
|
||
expand_gc_prologue_and_epilogue ()
|
||
{
|
||
extern tree maybe_gc_cleanup;
|
||
struct rtx_def *last_parm_insn, *mark;
|
||
extern struct rtx_def *get_last_insn ();
|
||
extern struct rtx_def *get_first_nonparm_insn ();
|
||
extern struct rtx_def *previous_insn ();
|
||
tree action;
|
||
|
||
/* If we didn't need the obstack, don't cons any space. */
|
||
if (current_function_obstack_index == 0
|
||
|| current_function_obstack_usage == 0)
|
||
return;
|
||
|
||
mark = get_last_insn ();
|
||
last_parm_insn = get_first_nonparm_insn ();
|
||
if (last_parm_insn == 0) last_parm_insn = mark;
|
||
else last_parm_insn = previous_insn (last_parm_insn);
|
||
|
||
action = build_function_call (gc_push_fndecl,
|
||
build_tree_list (NULL_TREE, size_int (++current_function_obstack_index)));
|
||
expand_expr_stmt (action);
|
||
|
||
reorder_insns (next_insn (mark), get_last_insn (), last_parm_insn);
|
||
|
||
/* This will be expanded as a cleanup. */
|
||
TREE_VALUE (maybe_gc_cleanup)
|
||
= build_function_call (gc_pop_fndecl, NULL_TREE);
|
||
}
|
||
|
||
/* Some day we'll use this function as a call-back and clean
|
||
up all the unnecessary gc dribble that we otherwise create. */
|
||
void
|
||
lang_expand_end_bindings (first, last)
|
||
struct rtx_def *first, *last;
|
||
{
|
||
}
|
||
|
||
void
|
||
init_gc_processing ()
|
||
{
|
||
tree parmtypes = hash_tree_chain (class_star_type_node,
|
||
hash_tree_chain (integer_type_node, NULL_TREE));
|
||
gc_protect_fndecl = define_function ("__gc_protect",
|
||
build_function_type (class_star_type_node, parmtypes),
|
||
NOT_BUILT_IN, 0, 0);
|
||
|
||
parmtypes = hash_tree_chain (integer_type_node, NULL_TREE);
|
||
gc_unprotect_fndecl = define_function ("__gc_unprotect",
|
||
build_function_type (void_type_node, parmtypes),
|
||
NOT_BUILT_IN, 0, 0);
|
||
|
||
gc_push_fndecl = define_function ("__gc_push",
|
||
TREE_TYPE (gc_unprotect_fndecl),
|
||
NOT_BUILT_IN, 0, 0);
|
||
|
||
gc_pop_fndecl = define_function ("__gc_pop",
|
||
build_function_type (void_type_node,
|
||
void_list_node),
|
||
NOT_BUILT_IN, 0, 0);
|
||
gc_nonobject = build_int_2 (0x80000000, 0);
|
||
gc_visible = build_int_2 (0x40000000, 0);
|
||
gc_white = integer_zero_node;
|
||
gc_offwhite = build_int_2 (0x10000000, 0);
|
||
gc_grey = build_int_2 (0x20000000, 0);
|
||
gc_black = build_int_2 (0x30000000, 0);
|
||
}
|