1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2011, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Debug_A; use Debug_A;
28 with Errout; use Errout;
29 with Exp_Aggr; use Exp_Aggr;
30 with Exp_Alfa; use Exp_Alfa;
31 with Exp_Attr; use Exp_Attr;
32 with Exp_Ch2; use Exp_Ch2;
33 with Exp_Ch3; use Exp_Ch3;
34 with Exp_Ch4; use Exp_Ch4;
35 with Exp_Ch5; use Exp_Ch5;
36 with Exp_Ch6; use Exp_Ch6;
37 with Exp_Ch7; use Exp_Ch7;
38 with Exp_Ch8; use Exp_Ch8;
39 with Exp_Ch9; use Exp_Ch9;
40 with Exp_Ch11; use Exp_Ch11;
41 with Exp_Ch12; use Exp_Ch12;
42 with Exp_Ch13; use Exp_Ch13;
43 with Exp_Prag; use Exp_Prag;
45 with Rtsfind; use Rtsfind;
47 with Sem_Ch8; use Sem_Ch8;
48 with Sem_Util; use Sem_Util;
49 with Sinfo; use Sinfo;
52 package body Expander is
58 -- The following table is used to save values of the Expander_Active flag
59 -- when they are saved by Expander_Mode_Save_And_Set. We use an extendible
60 -- table (which is a bit of overkill) because it is easier than figuring
61 -- out a maximum value or bothering with range checks!
63 package Expander_Flags is new Table.Table (
64 Table_Component_Type => Boolean,
65 Table_Index_Type => Int,
68 Table_Increment => 200,
69 Table_Name => "Expander_Flags");
75 procedure Expand (N : Node_Id) is
77 -- If we were analyzing a default expression (or other spec expression)
78 -- the Full_Analysis flag must be off. If we are in expansion mode then
79 -- we must be performing a full analysis. If we are analyzing a generic
80 -- then Expansion must be off.
83 (not (Full_Analysis and then In_Spec_Expression)
84 and then (Full_Analysis or else not Expander_Active)
85 and then not (Inside_A_Generic and then Expander_Active));
87 -- There are three reasons for the Expander_Active flag to be false
89 -- The first is when are not generating code. In this mode the
90 -- Full_Analysis flag indicates whether we are performing a complete
91 -- analysis, in which case Full_Analysis = True or a pre-analysis in
92 -- which case Full_Analysis = False. See the spec of Sem for more
95 -- The second reason for the Expander_Active flag to be False is that
96 -- we are performing a pre-analysis. During pre-analysis all expansion
97 -- activity is turned off to make sure nodes are semantically decorated
98 -- but no extra nodes are generated. This is for instance needed for
99 -- the first pass of aggregate semantic processing. Note that in this
100 -- case the Full_Analysis flag is set to False because the node will
101 -- subsequently be re-analyzed with expansion on (see the spec of sem).
103 -- Finally, expansion is turned off in a regular compilation if there
104 -- are serious errors. In that case there will be no further expansion,
105 -- but one cleanup action may be required: if a transient scope was
106 -- created (e.g. for a function that returns an unconstrained type) the
107 -- scope may still be on the stack, and must be removed explicitly,
108 -- given that the expansion actions that would normally process it will
109 -- not take place. This prevents cascaded errors due to stack mismatch.
111 if not Expander_Active then
112 Set_Analyzed (N, Full_Analysis);
114 if Serious_Errors_Detected > 0
115 and then Scope_Is_Transient
118 (Scope_Stack.Last).Actions_To_Be_Wrapped_Before := No_List;
120 (Scope_Stack.Last).Actions_To_Be_Wrapped_After := No_List;
128 Debug_A_Entry ("expanding ", N);
131 -- In Alfa mode we only need a very limited subset of the usual
132 -- expansions. This limited subset is implemented in Expand_Alfa.
137 -- Here for normal non-Alfa mode
140 -- Processing depends on node kind. For full details on the
141 -- expansion activity required in each case, see bodies of
142 -- corresponding expand routines.
146 when N_Abort_Statement =>
147 Expand_N_Abort_Statement (N);
149 when N_Accept_Statement =>
150 Expand_N_Accept_Statement (N);
153 Expand_N_Aggregate (N);
156 Expand_N_Allocator (N);
159 Expand_N_And_Then (N);
161 when N_Assignment_Statement =>
162 Expand_N_Assignment_Statement (N);
164 when N_Asynchronous_Select =>
165 Expand_N_Asynchronous_Select (N);
167 when N_Attribute_Definition_Clause =>
168 Expand_N_Attribute_Definition_Clause (N);
170 when N_Attribute_Reference =>
171 Expand_N_Attribute_Reference (N);
173 when N_Block_Statement =>
174 Expand_N_Block_Statement (N);
176 when N_Case_Expression =>
177 Expand_N_Case_Expression (N);
179 when N_Case_Statement =>
180 Expand_N_Case_Statement (N);
182 when N_Conditional_Entry_Call =>
183 Expand_N_Conditional_Entry_Call (N);
185 when N_Conditional_Expression =>
186 Expand_N_Conditional_Expression (N);
188 when N_Delay_Relative_Statement =>
189 Expand_N_Delay_Relative_Statement (N);
191 when N_Delay_Until_Statement =>
192 Expand_N_Delay_Until_Statement (N);
195 Expand_N_Entry_Body (N);
197 when N_Entry_Call_Statement =>
198 Expand_N_Entry_Call_Statement (N);
200 when N_Entry_Declaration =>
201 Expand_N_Entry_Declaration (N);
203 when N_Exception_Declaration =>
204 Expand_N_Exception_Declaration (N);
206 when N_Exception_Renaming_Declaration =>
207 Expand_N_Exception_Renaming_Declaration (N);
209 when N_Exit_Statement =>
210 Expand_N_Exit_Statement (N);
212 when N_Expanded_Name =>
213 Expand_N_Expanded_Name (N);
215 when N_Explicit_Dereference =>
216 Expand_N_Explicit_Dereference (N);
218 when N_Expression_With_Actions =>
219 Expand_N_Expression_With_Actions (N);
221 when N_Extended_Return_Statement =>
222 Expand_N_Extended_Return_Statement (N);
224 when N_Extension_Aggregate =>
225 Expand_N_Extension_Aggregate (N);
227 when N_Free_Statement =>
228 Expand_N_Free_Statement (N);
230 when N_Freeze_Entity =>
231 Expand_N_Freeze_Entity (N);
233 when N_Full_Type_Declaration =>
234 Expand_N_Full_Type_Declaration (N);
236 when N_Function_Call =>
237 Expand_N_Function_Call (N);
239 when N_Generic_Instantiation =>
240 Expand_N_Generic_Instantiation (N);
242 when N_Goto_Statement =>
243 Expand_N_Goto_Statement (N);
245 when N_Handled_Sequence_Of_Statements =>
246 Expand_N_Handled_Sequence_Of_Statements (N);
249 Expand_N_Identifier (N);
251 when N_Indexed_Component =>
252 Expand_N_Indexed_Component (N);
254 when N_If_Statement =>
255 Expand_N_If_Statement (N);
260 when N_Loop_Statement =>
261 Expand_N_Loop_Statement (N);
269 when N_Object_Declaration =>
270 Expand_N_Object_Declaration (N);
272 when N_Object_Renaming_Declaration =>
273 Expand_N_Object_Renaming_Declaration (N);
285 Expand_N_Op_Concat (N);
288 Expand_N_Op_Divide (N);
294 Expand_N_Op_Expon (N);
309 Expand_N_Op_Minus (N);
314 when N_Op_Multiply =>
315 Expand_N_Op_Multiply (N);
327 Expand_N_Op_Plus (N);
332 when N_Op_Rotate_Left =>
333 Expand_N_Op_Rotate_Left (N);
335 when N_Op_Rotate_Right =>
336 Expand_N_Op_Rotate_Right (N);
338 when N_Op_Shift_Left =>
339 Expand_N_Op_Shift_Left (N);
341 when N_Op_Shift_Right =>
342 Expand_N_Op_Shift_Right (N);
344 when N_Op_Shift_Right_Arithmetic =>
345 Expand_N_Op_Shift_Right_Arithmetic (N);
347 when N_Op_Subtract =>
348 Expand_N_Op_Subtract (N);
354 Expand_N_Or_Else (N);
356 when N_Package_Body =>
357 Expand_N_Package_Body (N);
359 when N_Package_Declaration =>
360 Expand_N_Package_Declaration (N);
362 when N_Package_Renaming_Declaration =>
363 Expand_N_Package_Renaming_Declaration (N);
365 when N_Subprogram_Renaming_Declaration =>
366 Expand_N_Subprogram_Renaming_Declaration (N);
371 when N_Procedure_Call_Statement =>
372 Expand_N_Procedure_Call_Statement (N);
374 when N_Protected_Type_Declaration =>
375 Expand_N_Protected_Type_Declaration (N);
377 when N_Protected_Body =>
378 Expand_N_Protected_Body (N);
380 when N_Qualified_Expression =>
381 Expand_N_Qualified_Expression (N);
383 when N_Quantified_Expression =>
384 Expand_N_Quantified_Expression (N);
386 when N_Raise_Statement =>
387 Expand_N_Raise_Statement (N);
389 when N_Raise_Constraint_Error =>
390 Expand_N_Raise_Constraint_Error (N);
392 when N_Raise_Program_Error =>
393 Expand_N_Raise_Program_Error (N);
395 when N_Raise_Storage_Error =>
396 Expand_N_Raise_Storage_Error (N);
398 when N_Real_Literal =>
399 Expand_N_Real_Literal (N);
401 when N_Record_Representation_Clause =>
402 Expand_N_Record_Representation_Clause (N);
404 when N_Requeue_Statement =>
405 Expand_N_Requeue_Statement (N);
407 when N_Simple_Return_Statement =>
408 Expand_N_Simple_Return_Statement (N);
410 when N_Selected_Component =>
411 Expand_N_Selected_Component (N);
413 when N_Selective_Accept =>
414 Expand_N_Selective_Accept (N);
416 when N_Single_Task_Declaration =>
417 Expand_N_Single_Task_Declaration (N);
422 when N_Subtype_Indication =>
423 Expand_N_Subtype_Indication (N);
425 when N_Subprogram_Body =>
426 Expand_N_Subprogram_Body (N);
428 when N_Subprogram_Body_Stub =>
429 Expand_N_Subprogram_Body_Stub (N);
431 when N_Subprogram_Declaration =>
432 Expand_N_Subprogram_Declaration (N);
434 when N_Subprogram_Info =>
435 Expand_N_Subprogram_Info (N);
438 Expand_N_Task_Body (N);
440 when N_Task_Type_Declaration =>
441 Expand_N_Task_Type_Declaration (N);
443 when N_Timed_Entry_Call =>
444 Expand_N_Timed_Entry_Call (N);
446 when N_Type_Conversion =>
447 Expand_N_Type_Conversion (N);
449 when N_Unchecked_Expression =>
450 Expand_N_Unchecked_Expression (N);
452 when N_Unchecked_Type_Conversion =>
453 Expand_N_Unchecked_Type_Conversion (N);
455 when N_Variant_Part =>
456 Expand_N_Variant_Part (N);
458 -- For all other node kinds, no expansion activity required
467 when RE_Not_Available =>
471 -- Set result as analyzed and then do a possible transient wrap. The
472 -- transient wrap must be done after the Analyzed flag is set on, so
473 -- that we do not get a recursive attempt to expand the node N.
477 -- Deal with transient scopes
479 if Scope_Is_Transient and then N = Node_To_Be_Wrapped then
481 when N_Statement_Other_Than_Procedure_Call |
482 N_Procedure_Call_Statement =>
483 Wrap_Transient_Statement (N);
485 when N_Object_Declaration |
486 N_Object_Renaming_Declaration |
487 N_Subtype_Declaration =>
488 Wrap_Transient_Declaration (N);
490 when others => Wrap_Transient_Expression (N);
494 Debug_A_Exit ("expanding ", N, " (done)");
498 ---------------------------
499 -- Expander_Mode_Restore --
500 ---------------------------
502 procedure Expander_Mode_Restore is
504 -- Not active (has no effect) in ASIS mode (see comments in spec of
505 -- Expander_Mode_Save_And_Set).
511 -- Otherwise restore the flag
513 Expander_Active := Expander_Flags.Table (Expander_Flags.Last);
514 Expander_Flags.Decrement_Last;
516 -- Keep expander off if serious errors detected. In this case we do not
517 -- need expansion, and continued expansion may cause cascaded errors or
520 if Serious_Errors_Detected /= 0 then
521 Expander_Active := False;
523 end Expander_Mode_Restore;
525 --------------------------------
526 -- Expander_Mode_Save_And_Set --
527 --------------------------------
529 procedure Expander_Mode_Save_And_Set (Status : Boolean) is
531 -- Not active (has no effect) in ASIS mode (see comments in spec of
532 -- Expander_Mode_Save_And_Set).
538 -- Otherwise save and set the flag
540 Expander_Flags.Increment_Last;
541 Expander_Flags.Table (Expander_Flags.Last) := Expander_Active;
542 Expander_Active := Status;
543 end Expander_Mode_Save_And_Set;