freebsd-nq/contrib/gcc/cp/expr.c
1999-10-16 06:09:09 +00:00

462 lines
12 KiB
C

/* Convert language-specific tree expression to rtl instructions,
for GNU compiler.
Copyright (C) 1988, 92-97, 1998 Free Software Foundation, Inc.
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, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include "config.h"
#include "system.h"
#include "rtl.h"
#include "tree.h"
#include "flags.h"
#include "expr.h"
#include "cp-tree.h"
#include "toplev.h"
#if 0
static tree extract_aggr_init PROTO((tree, tree));
static tree extract_scalar_init PROTO((tree, tree));
#endif
static rtx cplus_expand_expr PROTO((tree, rtx, enum machine_mode,
enum expand_modifier));
/* Hook used by output_constant to expand language-specific
constants. */
static tree
cplus_expand_constant (cst)
tree cst;
{
switch (TREE_CODE (cst))
{
case PTRMEM_CST:
{
tree type = TREE_TYPE (cst);
tree member;
tree offset;
/* Find the member. */
member = PTRMEM_CST_MEMBER (cst);
if (TREE_CODE (member) == FIELD_DECL)
{
/* Find the offset for the field. */
offset = convert (sizetype,
size_binop (EASY_DIV_EXPR,
DECL_FIELD_BITPOS (member),
size_int (BITS_PER_UNIT)));
/* We offset all pointer to data members by 1 so that we
can distinguish between a null pointer to data member
and the first data member of a structure. */
offset = size_binop (PLUS_EXPR, offset, size_int (1));
cst = cp_convert (type, offset);
}
else
{
tree delta;
tree idx;
tree pfn;
tree delta2;
expand_ptrmemfunc_cst (cst, &delta, &idx, &pfn, &delta2);
cst = build_ptrmemfunc1 (type, delta, idx,
pfn, delta2);
}
}
break;
default:
/* There's nothing to do. */
break;
}
return cst;
}
/* Hook used by expand_expr to expand language-specific tree codes. */
static rtx
cplus_expand_expr (exp, target, tmode, modifier)
tree exp;
rtx target;
enum machine_mode tmode;
enum expand_modifier modifier;
{
tree type = TREE_TYPE (exp);
register enum machine_mode mode = TYPE_MODE (type);
register enum tree_code code = TREE_CODE (exp);
int ignore = target == const0_rtx;
if (ignore)
target = 0;
/* No sense saving up arithmetic to be done
if it's all in the wrong mode to form part of an address.
And force_operand won't know whether to sign-extend or zero-extend. */
if (mode != Pmode && modifier == EXPAND_SUM)
modifier = EXPAND_NORMAL;
switch (code)
{
case AGGR_INIT_EXPR:
{
/* Something needs to be initialized, but we didn't know
where that thing was when building the tree. For example,
it could be the return value of a function, or a parameter
to a function which lays down in the stack, or a temporary
variable which must be passed by reference.
Cleanups are handled in a language-specific way: they
might be run by the called function (true in GNU C++
for parameters with cleanups), or they might be
run by the caller, after the call (true in GNU C++
for other cleanup needs). */
tree func = TREE_OPERAND (exp, 0);
tree args = TREE_OPERAND (exp, 1);
tree type = TREE_TYPE (exp), slot;
tree call_exp;
rtx call_target, return_target;
int pcc_struct_return = 0;
/* The expression `init' wants to initialize what
`target' represents. SLOT holds the slot for TARGET. */
slot = TREE_OPERAND (exp, 2);
/* Should always be called with a target. */
my_friendly_assert (target != NULL_RTX, 205);
/* The target the initializer will initialize (CALL_TARGET)
must now be directed to initialize the target we are
supposed to initialize (TARGET). The semantics for
choosing what CALL_TARGET is is language-specific,
as is building the call which will perform the
initialization. It is left here to show the choices that
exist for C++. */
if (TREE_CODE (func) == ADDR_EXPR
&& TREE_CODE (TREE_OPERAND (func, 0)) == FUNCTION_DECL
&& DECL_CONSTRUCTOR_P (TREE_OPERAND (func, 0)))
{
type = build_pointer_type (type);
/* Don't clobber a value that might be part of a default
parameter value. */
mark_addressable (slot);
if (TREE_PERMANENT (args))
args = expr_tree_cons (0, build1 (ADDR_EXPR, type, slot),
TREE_CHAIN (args));
else
TREE_VALUE (args) = build1 (ADDR_EXPR, type, slot);
call_target = 0;
}
else
{
call_target = target;
#ifdef PCC_STATIC_STRUCT_RETURN
if (aggregate_value_p (type))
{
pcc_struct_return = 1;
call_target = 0;
}
#endif
}
call_exp = build (CALL_EXPR, type, func, args, NULL_TREE);
TREE_SIDE_EFFECTS (call_exp) = 1;
return_target = expand_call (call_exp, call_target, ignore);
if (call_target)
/* Trust that the right thing has been done; it's too hard to
verify. */
return return_target;
/* If we're suffering under the ancient PCC_STATIC_STRUCT_RETURN
calling convention, we need to copy the return value out of
the static return buffer into slot. */
if (pcc_struct_return)
{
extern int flag_access_control;
int old_ac = flag_access_control;
tree init = build_decl (VAR_DECL, NULL_TREE,
build_reference_type (type));
DECL_RTL (init) = XEXP (return_target, 0);
init = convert_from_reference (init);
flag_access_control = 0;
expand_aggr_init (slot, init, LOOKUP_ONLYCONVERTING);
flag_access_control = old_ac;
if (TYPE_NEEDS_DESTRUCTOR (type))
{
init = maybe_build_cleanup (init);
if (init != NULL_TREE)
expand_expr (init, const0_rtx, VOIDmode, 0);
}
}
return DECL_RTL (slot);
}
case PTRMEM_CST:
return expand_expr (cplus_expand_constant (exp),
target, tmode, modifier);
case OFFSET_REF:
{
return expand_expr (default_conversion (resolve_offset_ref (exp)),
target, tmode, EXPAND_NORMAL);
}
case THUNK_DECL:
return DECL_RTL (exp);
case THROW_EXPR:
expand_throw (TREE_OPERAND (exp, 0));
return NULL;
case VEC_INIT_EXPR:
return expand_expr
(expand_vec_init
(NULL_TREE, TREE_OPERAND (exp, 0),
build_binary_op (MINUS_EXPR, TREE_OPERAND (exp, 2),
integer_one_node),
TREE_OPERAND (exp, 1), 0), target, tmode, modifier);
case NEW_EXPR:
return expand_expr (build_new_1 (exp), target, tmode, modifier);
default:
break;
}
my_friendly_abort (40);
/* NOTREACHED */
return NULL;
}
void
init_cplus_expand ()
{
lang_expand_expr = cplus_expand_expr;
lang_expand_constant = cplus_expand_constant;
}
/* If DECL had its rtl moved from where callers expect it
to be, fix it up. RESULT is the nominal rtl for the RESULT_DECL,
which may be a pseudo instead of a hard register. */
void
fixup_result_decl (decl, result)
tree decl;
rtx result;
{
if (REG_P (result))
{
if (REGNO (result) >= FIRST_PSEUDO_REGISTER)
{
rtx real_decl_result;
#ifdef FUNCTION_OUTGOING_VALUE
real_decl_result
= FUNCTION_OUTGOING_VALUE (TREE_TYPE (decl), current_function_decl);
#else
real_decl_result
= FUNCTION_VALUE (TREE_TYPE (decl), current_function_decl);
#endif
REG_FUNCTION_VALUE_P (real_decl_result) = 1;
result = real_decl_result;
}
store_expr (decl, result, 0);
emit_insn (gen_rtx (USE, VOIDmode, result));
}
}
#if 0
/* Expand this initialization inline and see if it's simple enough that
it can be done at compile-time. */
static tree
extract_aggr_init (decl, init)
tree decl, init;
{
return 0;
}
static tree
extract_scalar_init (decl, init)
tree decl, init;
{
rtx value, insns, insn;
extern struct obstack temporary_obstack;
tree t = NULL_TREE;
push_obstacks (&temporary_obstack, &temporary_obstack);
start_sequence ();
value = expand_expr (init, NULL_RTX, VOIDmode, 0);
insns = get_insns ();
end_sequence ();
reg_scan (insns, max_reg_num (), 0);
jump_optimize (insns, 0, 0, 1);
pop_obstacks ();
for (insn = insns; insn; insn = NEXT_INSN (insn))
{
rtx r, to;
if (GET_CODE (insn) == NOTE)
continue;
else if (GET_CODE (insn) != INSN)
return 0;
r = PATTERN (insn);
if (GET_CODE (r) != SET)
return 0;
to = XEXP (r, 0);
if (! (to == value
|| (GET_CODE (to) == SUBREG && XEXP (to, 0) == value)))
return 0;
r = XEXP (r, 1);
switch (GET_CODE (r))
{
case CONST_INT:
t = build_int_2 (XEXP (r, 0), 0);
break;
default:
return 0;
}
}
return t;
}
#endif
int
extract_init (decl, init)
tree decl ATTRIBUTE_UNUSED, init ATTRIBUTE_UNUSED;
{
return 0;
#if 0
if (IS_AGGR_TYPE (TREE_TYPE (decl))
|| TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
init = extract_aggr_init (decl, init);
else
init = extract_scalar_init (decl, init);
if (init == NULL_TREE)
return 0;
DECL_INITIAL (decl) = init;
return 1;
#endif
}
void
do_case (start, end)
tree start, end;
{
tree value1 = NULL_TREE, value2 = NULL_TREE, label;
if (start != NULL_TREE && TREE_TYPE (start) != NULL_TREE
&& POINTER_TYPE_P (TREE_TYPE (start)))
error ("pointers are not permitted as case values");
if (end && pedantic)
pedwarn ("ANSI C++ forbids range expressions in switch statement");
if (processing_template_decl)
{
add_tree (build_min_nt (CASE_LABEL, start, end));
return;
}
if (start)
value1 = check_cp_case_value (start);
if (end)
value2 = check_cp_case_value (end);
label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
if (value1 != error_mark_node
&& value2 != error_mark_node)
{
tree duplicate;
int success;
if (end)
success = pushcase_range (value1, value2, convert_and_check,
label, &duplicate);
else if (start)
success = pushcase (value1, convert_and_check, label, &duplicate);
else
success = pushcase (NULL_TREE, 0, label, &duplicate);
if (success == 1)
{
if (end)
error ("case label not within a switch statement");
else if (start)
cp_error ("case label `%E' not within a switch statement", start);
else
error ("default label not within a switch statement");
}
else if (success == 2)
{
if (end)
{
error ("duplicate (or overlapping) case value");
cp_error_at ("this is the first entry overlapping that value",
duplicate);
}
else if (start)
{
cp_error ("duplicate case value `%E'", start);
cp_error_at ("previously used here", duplicate);
}
else
{
error ("multiple default labels in one switch");
cp_error_at ("this is the first default label", duplicate);
}
}
else if (success == 3)
warning ("case value out of range");
else if (success == 4)
warning ("empty range specified");
else if (success == 5)
{
if (end)
error ("case label within scope of cleanup or variable array");
else if (! start)
error ("`default' label within scope of cleanup or variable array");
else
cp_error ("case label `%E' within scope of cleanup or variable array", start);
}
}
define_case_label ();
}