1 /* Convert language-specific tree expression to rtl instructions,
3 Copyright (C) 1988, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
5 This file is part of GNU CC.
7 GNU CC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 GNU CC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GNU CC; see the file COPYING. If not, write to
19 the Free Software Foundation, 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
33 static tree extract_aggr_init PROTO((tree, tree));
34 static tree extract_scalar_init PROTO((tree, tree));
36 static rtx cplus_expand_expr PROTO((tree, rtx, enum machine_mode,
37 enum expand_modifier));
39 /* Hook used by expand_expr to expand language-specific tree codes. */
42 cplus_expand_expr (exp, target, tmode, modifier)
45 enum machine_mode tmode;
46 enum expand_modifier modifier;
48 tree type = TREE_TYPE (exp);
49 register enum machine_mode mode = TYPE_MODE (type);
50 register enum tree_code code = TREE_CODE (exp);
51 int ignore = target == const0_rtx;
56 /* No sense saving up arithmetic to be done
57 if it's all in the wrong mode to form part of an address.
58 And force_operand won't know whether to sign-extend or zero-extend. */
60 if (mode != Pmode && modifier == EXPAND_SUM)
61 modifier = EXPAND_NORMAL;
67 /* Something needs to be initialized, but we didn't know
68 where that thing was when building the tree. For example,
69 it could be the return value of a function, or a parameter
70 to a function which lays down in the stack, or a temporary
71 variable which must be passed by reference.
73 Cleanups are handled in a language-specific way: they
74 might be run by the called function (true in GNU C++
75 for parameters with cleanups), or they might be
76 run by the caller, after the call (true in GNU C++
77 for other cleanup needs). */
79 tree func = TREE_OPERAND (exp, 0);
80 tree args = TREE_OPERAND (exp, 1);
81 tree type = TREE_TYPE (exp), slot;
83 rtx call_target, return_target;
84 int pcc_struct_return = 0;
86 /* The expression `init' wants to initialize what
87 `target' represents. SLOT holds the slot for TARGET. */
88 slot = TREE_OPERAND (exp, 2);
90 /* Should always be called with a target. */
91 my_friendly_assert (target != NULL_RTX, 205);
93 /* The target the initializer will initialize (CALL_TARGET)
94 must now be directed to initialize the target we are
95 supposed to initialize (TARGET). The semantics for
96 choosing what CALL_TARGET is is language-specific,
97 as is building the call which will perform the
98 initialization. It is left here to show the choices that
101 if (TREE_CODE (func) == ADDR_EXPR
102 && TREE_CODE (TREE_OPERAND (func, 0)) == FUNCTION_DECL
103 && DECL_CONSTRUCTOR_P (TREE_OPERAND (func, 0)))
105 type = build_pointer_type (type);
106 /* Don't clobber a value that might be part of a default
108 mark_addressable (slot);
109 if (TREE_PERMANENT (args))
110 args = expr_tree_cons (0, build1 (ADDR_EXPR, type, slot),
113 TREE_VALUE (args) = build1 (ADDR_EXPR, type, slot);
118 call_target = target;
119 #ifdef PCC_STATIC_STRUCT_RETURN
120 if (aggregate_value_p (type))
122 pcc_struct_return = 1;
128 call_exp = build (CALL_EXPR, type, func, args, NULL_TREE);
129 TREE_SIDE_EFFECTS (call_exp) = 1;
130 return_target = expand_call (call_exp, call_target, ignore);
133 /* Trust that the right thing has been done; it's too hard to
135 return return_target;
137 /* If we're suffering under the ancient PCC_STATIC_STRUCT_RETURN
138 calling convention, we need to copy the return value out of
139 the static return buffer into slot. */
140 if (pcc_struct_return)
142 extern int flag_access_control;
143 int old_ac = flag_access_control;
145 tree init = build_decl (VAR_DECL, NULL_TREE,
146 build_reference_type (type));
147 DECL_RTL (init) = XEXP (return_target, 0);
148 init = convert_from_reference (init);
150 flag_access_control = 0;
151 expand_aggr_init (slot, init, 0, LOOKUP_ONLYCONVERTING);
152 flag_access_control = old_ac;
154 if (TYPE_NEEDS_DESTRUCTOR (type))
156 init = maybe_build_cleanup (init);
157 if (init != NULL_TREE)
158 expand_expr (init, const0_rtx, VOIDmode, 0);
162 return DECL_RTL (slot);
168 return expand_expr (default_conversion (resolve_offset_ref (exp)),
169 target, tmode, EXPAND_NORMAL);
171 /* This is old crusty code, and does not handle all that the
172 resolve_offset_ref function does. (mrs) */
173 tree base = build_unary_op (ADDR_EXPR, TREE_OPERAND (exp, 0), 0);
174 tree offset = build_unary_op (ADDR_EXPR, TREE_OPERAND (exp, 1), 0);
175 return expand_expr (build (PLUS_EXPR, TREE_TYPE (exp), base, offset),
176 target, tmode, EXPAND_NORMAL);
181 return DECL_RTL (exp);
184 expand_throw (TREE_OPERAND (exp, 0));
190 (NULL_TREE, TREE_OPERAND (exp, 0),
191 build_binary_op (MINUS_EXPR, TREE_OPERAND (exp, 2),
192 integer_one_node, 1),
193 TREE_OPERAND (exp, 1), 0), target, tmode, modifier);
196 return expand_expr (build_new_1 (exp), target, tmode, modifier);
201 my_friendly_abort (40);
209 lang_expand_expr = cplus_expand_expr;
212 /* If DECL had its rtl moved from where callers expect it
213 to be, fix it up. RESULT is the nominal rtl for the RESULT_DECL,
214 which may be a pseudo instead of a hard register. */
217 fixup_result_decl (decl, result)
223 if (REGNO (result) >= FIRST_PSEUDO_REGISTER)
225 rtx real_decl_result;
227 #ifdef FUNCTION_OUTGOING_VALUE
229 = FUNCTION_OUTGOING_VALUE (TREE_TYPE (decl), current_function_decl);
232 = FUNCTION_VALUE (TREE_TYPE (decl), current_function_decl);
234 REG_FUNCTION_VALUE_P (real_decl_result) = 1;
235 result = real_decl_result;
237 store_expr (decl, result, 0);
238 emit_insn (gen_rtx (USE, VOIDmode, result));
243 /* Expand this initialization inline and see if it's simple enough that
244 it can be done at compile-time. */
247 extract_aggr_init (decl, init)
254 extract_scalar_init (decl, init)
257 rtx value, insns, insn;
258 extern struct obstack temporary_obstack;
261 push_obstacks (&temporary_obstack, &temporary_obstack);
263 value = expand_expr (init, NULL_RTX, VOIDmode, 0);
264 insns = get_insns ();
266 reg_scan (insns, max_reg_num (), 0);
267 jump_optimize (insns, 0, 0, 1);
270 for (insn = insns; insn; insn = NEXT_INSN (insn))
274 if (GET_CODE (insn) == NOTE)
276 else if (GET_CODE (insn) != INSN)
280 if (GET_CODE (r) != SET)
286 || (GET_CODE (to) == SUBREG && XEXP (to, 0) == value)))
291 switch (GET_CODE (r))
294 t = build_int_2 (XEXP (r, 0), 0);
306 extract_init (decl, init)
312 if (IS_AGGR_TYPE (TREE_TYPE (decl))
313 || TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
314 init = extract_aggr_init (decl, init);
316 init = extract_scalar_init (decl, init);
318 if (init == NULL_TREE)
321 DECL_INITIAL (decl) = init;
330 tree value1 = NULL_TREE, value2 = NULL_TREE, label;
332 if (start != NULL_TREE && TREE_TYPE (start) != NULL_TREE
333 && POINTER_TYPE_P (TREE_TYPE (start)))
334 error ("pointers are not permitted as case values");
337 pedwarn ("ANSI C++ forbids range expressions in switch statement");
339 if (processing_template_decl)
341 add_tree (build_min_nt (CASE_LABEL, start, end));
346 value1 = check_cp_case_value (start);
348 value2 = check_cp_case_value (end);
350 label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
352 if (value1 != error_mark_node
353 && value2 != error_mark_node)
359 success = pushcase_range (value1, value2, convert_and_check,
362 success = pushcase (value1, convert_and_check, label, &duplicate);
364 success = pushcase (NULL_TREE, 0, label, &duplicate);
369 error ("case label not within a switch statement");
371 cp_error ("case label `%E' not within a switch statement", start);
373 error ("default label not within a switch statement");
375 else if (success == 2)
379 error ("duplicate (or overlapping) case value");
380 cp_error_at ("this is the first entry overlapping that value",
385 cp_error ("duplicate case value `%E'", start);
386 cp_error_at ("previously used here", duplicate);
390 error ("multiple default labels in one switch");
391 cp_error_at ("this is the first default label", duplicate);
394 else if (success == 3)
395 warning ("case value out of range");
396 else if (success == 4)
397 warning ("empty range specified");
398 else if (success == 5)
401 error ("case label within scope of cleanup or variable array");
403 error ("`default' label within scope of cleanup or variable array");
405 cp_error ("case label `%E' within scope of cleanup or variable array", start);
409 define_case_label (label);
411 define_case_label (NULL_TREE);