1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
|
/* Handle exceptional things in C++.
Copyright (C) 1989, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
Contributed by Michael Tiemann <tiemann@cygnus.com>
Rewritten by Mike Stump <mrs@cygnus.com>, based upon an
initial re-implementation courtesy Tad Hunt.
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. */
/* High-level class interface. */
#include "config.h"
#include "tree.h"
#include "rtl.h"
#include "cp-tree.h"
#include "flags.h"
#include "obstack.h"
#include "expr.h"
tree protect_list;
extern void (*interim_eh_hook) PROTO((tree));
rtx expand_builtin_return_addr PROTO((enum built_in_function, int, rtx));
/* holds the fndecl for __builtin_return_address () */
tree builtin_return_address_fndecl;
tree throw_fndecl;
static int
doing_eh (do_warn)
int do_warn;
{
if (! flag_handle_exceptions)
{
static int warned = 0;
if (! warned && do_warn)
{
error ("exception handling disabled, use -fhandle-exceptions to enable.");
warned = 1;
}
return 0;
}
return 1;
}
/*
NO GNEWS IS GOOD GNEWS WITH GARRY GNUS: This version is much closer
to supporting exception handling as per ANSI C++ working draft.
It is a complete rewrite of all the EH stuff that was here before
Shortcomings:
1. Throw specifications of functions still don't work.
Cool Things:
1. Destructors are called properly :-)
2. No overhead for the non-exception thrown case.
3. Fixing shortcoming 1 is simple.
-Tad Hunt (tad@mail.csh.rit.edu)
*/
/* A couple of backend routines from m88k.c */
/* used to cache a call to __builtin_return_address () */
static tree BuiltinReturnAddress;
#include <stdio.h>
/* XXX - Tad: for EH */
/* output an exception table entry */
static void
output_exception_table_entry (file, start_label, end_label, eh_label)
FILE *file;
rtx start_label, end_label, eh_label;
{
char label[100];
assemble_integer (start_label, GET_MODE_SIZE (Pmode), 1);
assemble_integer (end_label, GET_MODE_SIZE (Pmode), 1);
assemble_integer (eh_label, GET_MODE_SIZE (Pmode), 1);
putc ('\n', file); /* blank line */
}
static void
easy_expand_asm (str)
char *str;
{
expand_asm (build_string (strlen (str)+1, str));
}
#if 0
/* This is the startup, and finish stuff per exception table. */
/* XXX - Tad: exception handling section */
#ifndef EXCEPT_SECTION_ASM_OP
#define EXCEPT_SECTION_ASM_OP "section\t.gcc_except_table,\"a\",@progbits"
#endif
#ifdef EXCEPT_SECTION_ASM_OP
typedef struct {
void *start_protect;
void *end_protect;
void *exception_handler;
} exception_table;
#endif /* EXCEPT_SECTION_ASM_OP */
#ifdef EXCEPT_SECTION_ASM_OP
/* on machines which support it, the exception table lives in another section,
but it needs a label so we can reference it... This sets up that
label! */
asm (EXCEPT_SECTION_ASM_OP);
exception_table __EXCEPTION_TABLE__[1] = { (void*)0, (void*)0, (void*)0 };
asm (TEXT_SECTION_ASM_OP);
#endif /* EXCEPT_SECTION_ASM_OP */
#ifdef EXCEPT_SECTION_ASM_OP
/* we need to know where the end of the exception table is... so this
is how we do it! */
asm (EXCEPT_SECTION_ASM_OP);
exception_table __EXCEPTION_END__[1] = { (void*)-1, (void*)-1, (void*)-1 };
asm (TEXT_SECTION_ASM_OP);
#endif /* EXCEPT_SECTION_ASM_OP */
#endif
void
exception_section ()
{
#ifdef ASM_OUTPUT_SECTION_NAME
named_section (NULL_TREE, ".gcc_except_table");
#else
if (flag_pic)
data_section ();
else
#if defined(TARGET_POWERPC) /* are we on a __rs6000? */
data_section ();
#else
readonly_data_section ();
#endif
#endif
}
/* from: my-cp-except.c */
/* VI: ":set ts=4" */
#if 0
#include <stdio.h> */
#include "config.h"
#include "tree.h"
#include "rtl.h"
#include "cp-tree.h"
#endif
#include "decl.h"
#if 0
#include "flags.h"
#endif
#include "insn-flags.h"
#include "obstack.h"
#if 0
#include "expr.h"
#endif
/* ======================================================================
Briefly the algorithm works like this:
When a constructor or start of a try block is encountered,
push_eh_entry (&eh_stack) is called. Push_eh_entry () creates a
new entry in the unwind protection stack and returns a label to
output to start the protection for that block.
When a destructor or end try block is encountered, pop_eh_entry
(&eh_stack) is called. Pop_eh_entry () returns the ehEntry it
created when push_eh_entry () was called. The ehEntry structure
contains three things at this point. The start protect label,
the end protect label, and the exception handler label. The end
protect label should be output before the call to the destructor
(if any). If it was a destructor, then its parse tree is stored
in the finalization variable in the ehEntry structure. Otherwise
the finalization variable is set to NULL to reflect the fact that
is the the end of a try block. Next, this modified ehEntry node
is enqueued in the finalizations queue by calling
enqueue_eh_entry (&queue,entry).
+---------------------------------------------------------------+
|XXX: Will need modification to deal with partially |
| constructed arrays of objects |
| |
| Basically, this consists of keeping track of how many |
| of the objects have been constructed already (this |
| should be in a register though, so that shouldn't be a |
| problem. |
+---------------------------------------------------------------+
When a catch block is encountered, there is a lot of work to be
done.
Since we don't want to generate the catch block inline with the
regular flow of the function, we need to have some way of doing
so. Luckily, we can use sequences to defer the catch sections.
When the start of a catch block is encountered, we start the
sequence. After the catch block is generated, we end the
sequence.
Next we must insure that when the catch block is executed, all
finalizations for the matching try block have been completed. If
any of those finalizations throw an exception, we must call
terminate according to the ARM (section r.15.6.1). What this
means is that we need to dequeue and emit finalizations for each
entry in the ehQueue until we get to an entry with a NULL
finalization field. For any of the finalization entries, if it
is not a call to terminate (), we must protect it by giving it
another start label, end label, and exception handler label,
setting its finalization tree to be a call to terminate (), and
enqueue'ing this new ehEntry to be output at an outer level.
Finally, after all that is done, we can get around to outputting
the catch block which basically wraps all the "catch (...) {...}"
statements in a big if/then/else construct that matches the
correct block to call.
===================================================================== */
extern rtx emit_insn PROTO((rtx));
extern rtx gen_nop PROTO(());
/* local globals for function calls
====================================================================== */
/* used to cache "terminate ()", "unexpected ()", "set_terminate ()", and
"set_unexpected ()" after default_conversion. (lib-except.c) */
static tree Terminate, Unexpected, SetTerminate, SetUnexpected, CatchMatch, Throw;
/* used to cache __find_first_exception_table_match ()
for throw (lib-except.c) */
static tree FirstExceptionMatch;
/* used to cache a call to __unwind_function () (lib-except.c) */
static tree Unwind;
/* holds a ready to emit call to "terminate ()". */
static tree TerminateFunctionCall;
/* ====================================================================== */
/* data structures for my various quick and dirty stacks and queues
Eventually, most of this should go away, because I think it can be
integrated with stuff already built into the compiler. */
/* =================================================================== */
struct labelNode {
rtx label;
struct labelNode *chain;
};
/* this is the most important structure here. Basically this is how I store
an exception table entry internally. */
struct ehEntry {
rtx start_label;
rtx end_label;
rtx exception_handler_label;
tree finalization;
tree context;
};
struct ehNode {
struct ehEntry *entry;
struct ehNode *chain;
};
struct ehStack {
struct ehNode *top;
};
struct ehQueue {
struct ehNode *head;
struct ehNode *tail;
};
/* ========================================================================= */
/* local globals - these local globals are for storing data necessary for
generating the exception table and code in the correct order.
========================================================================= */
/* Holds the pc for doing "throw" */
tree saved_pc;
/* Holds the type of the thing being thrown. */
tree saved_throw_type;
/* Holds the value being thrown. */
tree saved_throw_value;
int throw_used;
static rtx catch_clauses;
static first_catch_label;
static struct ehStack ehstack;
static struct ehQueue ehqueue;
static struct ehQueue eh_table_output_queue;
static struct labelNode *false_label_stack = NULL;
static struct labelNode *caught_return_label_stack = NULL;
/* ========================================================================= */
/* function prototypes */
static struct ehEntry *pop_eh_entry PROTO((struct ehStack *stack));
static void enqueue_eh_entry PROTO((struct ehQueue *queue, struct ehEntry *entry));
static rtx push_eh_entry PROTO((struct ehStack *stack));
static struct ehEntry *dequeue_eh_entry PROTO((struct ehQueue *queue));
static void new_eh_queue PROTO((struct ehQueue *queue));
static void new_eh_stack PROTO((struct ehStack *stack));
static void push_label_entry PROTO((struct labelNode **labelstack, rtx label));
static rtx pop_label_entry PROTO((struct labelNode **labelstack));
static rtx top_label_entry PROTO((struct labelNode **labelstack));
static struct ehEntry *copy_eh_entry PROTO((struct ehEntry *entry));
/* All my cheesy stack/queue/misc data structure handling routines
========================================================================= */
static void
push_label_entry (labelstack, label)
struct labelNode **labelstack;
rtx label;
{
struct labelNode *newnode=(struct labelNode*)xmalloc (sizeof (struct labelNode));
newnode->label = label;
newnode->chain = *labelstack;
*labelstack = newnode;
}
static rtx
pop_label_entry (labelstack)
struct labelNode **labelstack;
{
rtx label;
struct labelNode *tempnode;
if (! *labelstack) return NULL_RTX;
tempnode = *labelstack;
label = tempnode->label;
*labelstack = (*labelstack)->chain;
free (tempnode);
return label;
}
static rtx
top_label_entry (labelstack)
struct labelNode **labelstack;
{
if (! *labelstack) return NULL_RTX;
return (*labelstack)->label;
}
/* Push to permanent obstack for rtl generation.
One level only! */
static struct obstack *saved_rtl_obstack;
void
push_rtl_perm ()
{
extern struct obstack permanent_obstack;
extern struct obstack *rtl_obstack;
saved_rtl_obstack = rtl_obstack;
rtl_obstack = &permanent_obstack;
}
/* Pop back to normal rtl handling. */
static void
pop_rtl_from_perm ()
{
extern struct obstack permanent_obstack;
extern struct obstack *rtl_obstack;
rtl_obstack = saved_rtl_obstack;
}
static rtx
push_eh_entry (stack)
struct ehStack *stack;
{
struct ehNode *node = (struct ehNode*)xmalloc (sizeof (struct ehNode));
struct ehEntry *entry = (struct ehEntry*)xmalloc (sizeof (struct ehEntry));
if (stack == NULL) {
free (node);
free (entry);
return NULL_RTX;
}
/* These are saved for the exception table. */
push_rtl_perm ();
entry->start_label = gen_label_rtx ();
entry->end_label = gen_label_rtx ();
entry->exception_handler_label = gen_label_rtx ();
pop_rtl_from_perm ();
LABEL_PRESERVE_P (entry->start_label) = 1;
LABEL_PRESERVE_P (entry->end_label) = 1;
LABEL_PRESERVE_P (entry->exception_handler_label) = 1;
entry->finalization = NULL_TREE;
entry->context = current_function_decl;
node->entry = entry;
node->chain = stack->top;
stack->top = node;
enqueue_eh_entry (&eh_table_output_queue, copy_eh_entry (entry));
return entry->start_label;
}
static struct ehEntry *
pop_eh_entry (stack)
struct ehStack *stack;
{
struct ehNode *tempnode;
struct ehEntry *tempentry;
if (stack && (tempnode = stack->top)) {
tempentry = tempnode->entry;
stack->top = stack->top->chain;
free (tempnode);
return tempentry;
}
return NULL;
}
static struct ehEntry *
copy_eh_entry (entry)
struct ehEntry *entry;
{
struct ehEntry *newentry;
newentry = (struct ehEntry*)xmalloc (sizeof (struct ehEntry));
memcpy ((void*)newentry, (void*)entry, sizeof (struct ehEntry));
return newentry;
}
static void
enqueue_eh_entry (queue, entry)
struct ehQueue *queue;
struct ehEntry *entry;
{
struct ehNode *node = (struct ehNode*)xmalloc (sizeof (struct ehNode));
node->entry = entry;
node->chain = NULL;
if (queue->head == NULL)
{
queue->head = node;
}
else
{
queue->tail->chain = node;
}
queue->tail = node;
}
static struct ehEntry *
dequeue_eh_entry (queue)
struct ehQueue *queue;
{
struct ehNode *tempnode;
struct ehEntry *tempentry;
if (queue->head == NULL)
return NULL;
tempnode = queue->head;
queue->head = queue->head->chain;
tempentry = tempnode->entry;
free (tempnode);
return tempentry;
}
static void
new_eh_queue (queue)
struct ehQueue *queue;
{
queue->head = queue->tail = NULL;
}
static void
new_eh_stack (stack)
struct ehStack *stack;
{
stack->top = NULL;
}
/* cheesyness to save some typing. returns the return value rtx */
rtx
do_function_call (func, params, return_type)
tree func, params, return_type;
{
tree func_call;
func_call = build_function_call (func, params);
expand_call (func_call, NULL_RTX, 0);
if (return_type != NULL_TREE)
return hard_function_value (return_type, func_call);
return NULL_RTX;
}
static void
expand_internal_throw (pc)
rtx pc;
{
tree params;
emit_move_insn (DECL_RTL (saved_pc), pc);
#ifdef JUMP_TO_THROW
emit_indirect_jump (gen_rtx (SYMBOL_REF, Pmode, "__throw"));
#else
do_function_call (Throw, NULL_TREE, NULL_TREE);
#endif
throw_used = 1;
}
/* ========================================================================= */
void
lang_interim_eh (finalization)
tree finalization;
{
if (finalization)
end_protect (finalization);
else
start_protect ();
}
extern tree auto_function PROTO((tree, tree, enum built_in_function));
/* sets up all the global eh stuff that needs to be initialized at the
start of compilation.
This includes:
- Setting up all the function call trees
- Initializing the ehqueue
- Initializing the eh_table_output_queue
- Initializing the ehstack
*/
void
init_exception_processing ()
{
extern tree define_function ();
tree unexpected_fndecl, terminate_fndecl;
tree set_unexpected_fndecl, set_terminate_fndecl;
tree catch_match_fndecl;
tree find_first_exception_match_fndecl;
tree unwind_fndecl;
tree declspecs;
tree d;
/* void (*)() */
tree PFV = build_pointer_type (build_function_type
(void_type_node, void_list_node));
/* arg list for the build_function_type call for set_terminate () and
set_unexpected () */
tree pfvlist = tree_cons (NULL_TREE, PFV, void_list_node);
/* void (*pfvtype (void (*) ()))() */
tree pfvtype = build_function_type (PFV, pfvlist);
/* void vtype () */
tree vtype = build_function_type (void_type_node, void_list_node);
set_terminate_fndecl = auto_function (get_identifier ("set_terminate"),
pfvtype, NOT_BUILT_IN);
set_unexpected_fndecl = auto_function (get_identifier ("set_unexpected"),
pfvtype, NOT_BUILT_IN);
unexpected_fndecl = auto_function (get_identifier ("unexpected"),
vtype, NOT_BUILT_IN);
terminate_fndecl = auto_function (get_identifier ("terminate"),
vtype, NOT_BUILT_IN);
interim_eh_hook = lang_interim_eh;
push_lang_context (lang_name_c);
catch_match_fndecl =
define_function (flag_rtti
? "__throw_type_match_rtti"
: "__throw_type_match",
build_function_type (ptr_type_node,
tree_cons (NULL_TREE, ptr_type_node,
tree_cons (NULL_TREE, ptr_type_node,
tree_cons (NULL_TREE, ptr_type_node,
void_list_node)))),
NOT_BUILT_IN,
pushdecl,
0);
find_first_exception_match_fndecl =
define_function ("__find_first_exception_table_match",
build_function_type (ptr_type_node,
tree_cons (NULL_TREE, ptr_type_node,
void_list_node)),
NOT_BUILT_IN,
pushdecl,
0);
unwind_fndecl =
define_function ("__unwind_function",
build_function_type (void_type_node,
tree_cons (NULL_TREE, ptr_type_node,
void_list_node)),
NOT_BUILT_IN,
pushdecl,
0);
throw_fndecl =
define_function ("__throw",
build_function_type (void_type_node, void_list_node),
NOT_BUILT_IN,
pushdecl,
0);
DECL_EXTERNAL (throw_fndecl) = 0;
TREE_PUBLIC (throw_fndecl) = 0;
Unexpected = default_conversion (unexpected_fndecl);
Terminate = default_conversion (terminate_fndecl);
SetTerminate = default_conversion (set_terminate_fndecl);
SetUnexpected = default_conversion (set_unexpected_fndecl);
CatchMatch = default_conversion (catch_match_fndecl);
FirstExceptionMatch = default_conversion (find_first_exception_match_fndecl);
Unwind = default_conversion (unwind_fndecl);
Throw = default_conversion (throw_fndecl);
BuiltinReturnAddress = default_conversion (builtin_return_address_fndecl);
TerminateFunctionCall = build_function_call (Terminate, NULL_TREE);
pop_lang_context ();
new_eh_queue (&ehqueue);
new_eh_queue (&eh_table_output_queue);
new_eh_stack (&ehstack);
declspecs = tree_cons (NULL_TREE, get_identifier ("void"), NULL_TREE);
d = build_parse_node (INDIRECT_REF, get_identifier ("__eh_pc"));
d = start_decl (d, declspecs, 0, NULL_TREE);
DECL_COMMON (d) = 1;
cp_finish_decl (d, NULL_TREE, NULL_TREE, 0, 0);
saved_pc = lookup_name (get_identifier ("__eh_pc"), 0);
declspecs = tree_cons (NULL_TREE, get_identifier ("void"), NULL_TREE);
d = build_parse_node (INDIRECT_REF, get_identifier ("__eh_type"));
d = start_decl (d, declspecs, 0, NULL_TREE);
DECL_COMMON (d) = 1;
cp_finish_decl (d, NULL_TREE, NULL_TREE, 0, 0);
saved_throw_type = lookup_name (get_identifier ("__eh_type"), 0);
declspecs = tree_cons (NULL_TREE, get_identifier ("void"), NULL_TREE);
d = build_parse_node (INDIRECT_REF, get_identifier ("__eh_value"));
d = start_decl (d, declspecs, 0, NULL_TREE);
DECL_COMMON (d) = 1;
cp_finish_decl (d, NULL_TREE, NULL_TREE, 0, 0);
saved_throw_value = lookup_name (get_identifier ("__eh_value"), 0);
}
/* call this to begin a block of unwind protection (ie: when an object is
constructed) */
void
start_protect ()
{
if (! doing_eh (0))
return;
emit_label (push_eh_entry (&ehstack));
}
/* call this to end a block of unwind protection. the finalization tree is
the finalization which needs to be run in order to cleanly unwind through
this level of protection. (ie: call this when a scope is exited)*/
void
end_protect (finalization)
tree finalization;
{
struct ehEntry *entry;
if (! doing_eh (0))
return;
entry = pop_eh_entry (&ehstack);
emit_label (entry->end_label);
/* Put in something that takes up space, as otherwise the end
address for the EH region could have the exact same address as
the outer region, causing us to miss the fact that resuming
exception handling with this PC value would be inside the outer
region. */
emit_insn (gen_nop ());
entry->finalization = finalization;
enqueue_eh_entry (&ehqueue, entry);
}
/* call this on start of a try block. */
void
expand_start_try_stmts ()
{
if (! doing_eh (1))
return;
start_protect ();
}
void
expand_end_try_stmts ()
{
end_protect (integer_zero_node);
}
/* call this to start processing of all the catch blocks. */
void
expand_start_all_catch ()
{
struct ehEntry *entry;
rtx label;
if (! doing_eh (1))
return;
emit_line_note (input_filename, lineno);
label = gen_label_rtx ();
/* The label for the exception handling block we will save. This is
Lresume, in the documention. */
emit_label (label);
/* Put in something that takes up space, as otherwise the end
address for the EH region could have the exact same address as
the outer region, causing us to miss the fact that resuming
exception handling with this PC value would be inside the outer
region. */
emit_insn (gen_nop ());
push_label_entry (&caught_return_label_stack, label);
/* Start a new sequence for all the catch blocks. We will add this
to the gloabl sequence catch_clauses, when we have completed all
the handlers in this handler-seq. */
start_sequence ();
while (1)
{
entry = dequeue_eh_entry (&ehqueue);
emit_label (entry->exception_handler_label);
expand_expr (entry->finalization, const0_rtx, VOIDmode, 0);
/* When we get down to the matching entry, stop. */
if (entry->finalization == integer_zero_node)
break;
/* The below can be optimized away, and we could just fall into the
next EH handler, if we are certain they are nested. */
/* Code to throw out to outer context, if we fall off end of the
handler. */
expand_internal_throw (gen_rtx (LABEL_REF,
Pmode,
entry->end_label));
free (entry);
}
}
/* call this to end processing of all the catch blocks. */
void
expand_end_all_catch ()
{
rtx new_catch_clause;
if (! doing_eh (1))
return;
/* Code to throw out to outer context, if we fall off end of catch
handlers. This is rethrow (Lresume, same id, same obj); in the
documentation. */
expand_internal_throw (gen_rtx (LABEL_REF,
Pmode,
top_label_entry (&caught_return_label_stack)));
/* Now we have the complete catch sequence. */
new_catch_clause = get_insns ();
end_sequence ();
/* this level of catch blocks is done, so set up the successful catch jump
label for the next layer of catch blocks. */
pop_label_entry (&caught_return_label_stack);
/* Add the new sequence of catchs to the main one for this
function. */
push_to_sequence (catch_clauses);
emit_insns (new_catch_clause);
catch_clauses = get_insns ();
end_sequence ();
/* Here we fall through into the continuation code. */
}
/* Build a type value for use at runtime for a type that is matched
against by the exception handling system. */
static tree
build_eh_type_type (type)
tree type;
{
char *typestring;
tree exp;
if (type == error_mark_node)
return error_mark_node;
/* peel back references, so they match. */
if (TREE_CODE (type) == REFERENCE_TYPE)
type = TREE_TYPE (type);
/* Peel off cv qualifiers. */
type = TYPE_MAIN_VARIANT (type);
if (flag_rtti)
{
return build1 (ADDR_EXPR, ptr_type_node, get_typeid (type));
}
typestring = build_overload_name (type, 1, 1);
exp = combine_strings (build_string (strlen (typestring)+1, typestring));
return build1 (ADDR_EXPR, ptr_type_node, exp);
}
/* Build a type value for use at runtime for a exp that is thrown or
matched against by the exception handling system. */
static tree
build_eh_type (exp)
tree exp;
{
if (flag_rtti)
{
exp = build_typeid (exp);
return build1 (ADDR_EXPR, ptr_type_node, exp);
}
return build_eh_type_type (TREE_TYPE (exp));
}
/* call this to start a catch block. Typename is the typename, and identifier
is the variable to place the object in or NULL if the variable doesn't
matter. If typename is NULL, that means its a "catch (...)" or catch
everything. In that case we don't need to do any type checking.
(ie: it ends up as the "else" clause rather than an "else if" clause) */
void
expand_start_catch_block (declspecs, declarator)
tree declspecs, declarator;
{
rtx false_label_rtx;
rtx protect_label_rtx;
tree decl = NULL_TREE;
tree init;
if (! doing_eh (1))
return;
/* Create a binding level for the parm. */
expand_start_bindings (0);
false_label_rtx = gen_label_rtx ();
/* This is saved for the exception table. */
push_rtl_perm ();
protect_label_rtx = gen_label_rtx ();
pop_rtl_from_perm ();
push_label_entry (&false_label_stack, false_label_rtx);
push_label_entry (&false_label_stack, protect_label_rtx);
if (declspecs)
{
tree exp;
rtx call_rtx, return_value_rtx;
tree init_type;
decl = grokdeclarator (declarator, declspecs, CATCHPARM, 1,
NULL_TREE, NULL_TREE);
if (decl == NULL_TREE)
{
error ("invalid catch parameter");
return;
}
/* Figure out the type that the initializer is. */
init_type = TREE_TYPE (decl);
if (TREE_CODE (init_type) != REFERENCE_TYPE
&& TREE_CODE (init_type) != POINTER_TYPE)
init_type = build_reference_type (init_type);
exp = saved_throw_value;
exp = tree_cons (NULL_TREE,
build_eh_type_type (TREE_TYPE (decl)),
tree_cons (NULL_TREE,
saved_throw_type,
tree_cons (NULL_TREE, exp, NULL_TREE)));
exp = build_function_call (CatchMatch, exp);
call_rtx = expand_call (exp, NULL_RTX, 0);
assemble_external (TREE_OPERAND (CatchMatch, 0));
return_value_rtx = hard_function_value (ptr_type_node, exp);
/* did the throw type match function return TRUE? */
emit_cmp_insn (return_value_rtx, const0_rtx, EQ, NULL_RTX,
GET_MODE (return_value_rtx), 0, 0);
/* if it returned FALSE, jump over the catch block, else fall into it */
emit_jump_insn (gen_beq (false_label_rtx));
init = convert_from_reference (save_expr (make_tree (init_type, call_rtx)));
/* Do we need the below two lines? */
/* Let `cp_finish_decl' know that this initializer is ok. */
DECL_INITIAL (decl) = init;
decl = pushdecl (decl);
cp_finish_decl (decl, init, NULL_TREE, 0, LOOKUP_ONLYCONVERTING);
}
else
{
/* Fall into the catch all section. */
}
/* This is the starting of something to protect. */
emit_label (protect_label_rtx);
emit_line_note (input_filename, lineno);
}
/* this is called from expand_exception_blocks and
expand_end_catch_block to expand the toplevel finalizations for a
function. We return the first label emitted, if any, otherwise
return NULL_RTX. */
static rtx
expand_leftover_cleanups ()
{
struct ehEntry *entry;
rtx first_label = NULL_RTX;
while ((entry = dequeue_eh_entry (&ehqueue)) != 0)
{
if (! first_label)
first_label = entry->exception_handler_label;
emit_label (entry->exception_handler_label);
expand_expr (entry->finalization, const0_rtx, VOIDmode, 0);
/* The below can be optimized away, and we could just fall into the
next EH handler, if we are certain they are nested. */
/* Code to throw out to outer context, if we fall off end of the
handler. */
expand_internal_throw (gen_rtx (LABEL_REF,
Pmode,
entry->end_label));
/* leftover try block, opps. */
if (entry->finalization == integer_zero_node)
abort ();
free (entry);
}
return first_label;
}
/* Call this to end a catch block. Its responsible for emitting the
code to handle jumping back to the correct place, and for emitting
the label to jump to if this catch block didn't match. */
void expand_end_catch_block ()
{
rtx start_protect_label_rtx;
rtx end_protect_label_rtx;
tree decls;
struct ehEntry entry;
if (! doing_eh (1))
return;
/* fall to outside the try statement when done executing handler and
we fall off end of handler. This is jump Lresume in the
documentation. */
emit_jump (top_label_entry (&caught_return_label_stack));
/* We end the rethrow protection region as soon as we hit a label. */
end_protect_label_rtx = expand_leftover_cleanups ();
/* Code to throw out to outer context, if we get a throw from within
our catch handler. */
/* These are saved for the exception table. */
push_rtl_perm ();
entry.exception_handler_label = gen_label_rtx ();
pop_rtl_from_perm ();
/* This label is Lhandler in the documentation. */
emit_label (entry.exception_handler_label);
expand_internal_throw (gen_rtx (LABEL_REF,
Pmode,
top_label_entry (&caught_return_label_stack)));
/* No associated finalization. */
entry.finalization = NULL_TREE;
entry.context = current_function_decl;
if (end_protect_label_rtx == NULL_RTX)
end_protect_label_rtx = entry.exception_handler_label;
/* Because we are emitted out of line, we have to protect this. */
/* label for the start of the protection region. */
start_protect_label_rtx = pop_label_entry (&false_label_stack);
/* Cleanup the EH parameter. */
decls = getdecls ();
expand_end_bindings (decls, decls != NULL_TREE, 0);
/* label we emit to jump to if this catch block didn't match. */
/* This the closing } in the `if (eq) {' of the documentation. */
emit_label (pop_label_entry (&false_label_stack));
/* Because we are reordered out of line, we have to protect this. */
entry.start_label = start_protect_label_rtx;
entry.end_label = end_protect_label_rtx;
LABEL_PRESERVE_P (entry.start_label) = 1;
LABEL_PRESERVE_P (entry.end_label) = 1;
LABEL_PRESERVE_P (entry.exception_handler_label) = 1;
/* These set up a call to throw the caught exception into the outer
context. */
enqueue_eh_entry (&eh_table_output_queue, copy_eh_entry (&entry));
}
/* unwind the stack. */
static void
do_unwind (inner_throw_label)
rtx inner_throw_label;
{
#if defined(SPARC_STACK_ALIGN) /* was sparc */
tree fcall;
tree params;
rtx return_val_rtx;
rtx temp;
/* call to __builtin_return_address () */
params = tree_cons (NULL_TREE, integer_zero_node, NULL_TREE);
fcall = build_function_call (BuiltinReturnAddress, params);
return_val_rtx = expand_expr (fcall, NULL_RTX, Pmode, 0);
/* In the return, the new pc is pc+8, as the value coming in is
really the address of the call insn, not the next insn. */
temp = gen_reg_rtx (Pmode);
emit_move_insn (temp, inner_throw_label);
emit_move_insn (return_val_rtx, plus_constant (temp, -8));
easy_expand_asm ("ret");
easy_expand_asm ("restore");
emit_barrier ();
#endif
#if defined(ARM_FRAME_RTX) /* was __arm */
if (flag_omit_frame_pointer)
sorry ("this implementation of exception handling requires a frame pointer");
emit_move_insn (stack_pointer_rtx,
gen_rtx (MEM, Pmode, plus_constant (hard_frame_pointer_rtx, -8)));
emit_move_insn (hard_frame_pointer_rtx,
gen_rtx (MEM, Pmode, plus_constant (hard_frame_pointer_rtx, -12)));
#endif
#if defined(TARGET_88000) /* was m88k */
rtx temp_frame = frame_pointer_rtx;
temp_frame = memory_address (Pmode, temp_frame);
temp_frame = copy_to_reg (gen_rtx (MEM, Pmode, temp_frame));
/* hopefully this will successfully pop the frame! */
emit_move_insn (frame_pointer_rtx, temp_frame);
emit_move_insn (stack_pointer_rtx, frame_pointer_rtx);
emit_move_insn (arg_pointer_rtx, frame_pointer_rtx);
emit_insn (gen_add2_insn (stack_pointer_rtx, gen_rtx (CONST_INT, VOIDmode,
(HOST_WIDE_INT)m88k_debugger_offset (stack_pointer_rtx, 0))));
#if 0
emit_insn (gen_add2_insn (arg_pointer_rtx, gen_rtx (CONST_INT, VOIDmode,
-(HOST_WIDE_INT)m88k_debugger_offset (arg_pointer_rtx, 0))));
emit_move_insn (stack_pointer_rtx, arg_pointer_rtx);
emit_insn (gen_add2_insn (stack_pointer_rtx, gen_rtx (CONST_INT, VOIDmode,
(HOST_WIDE_INT)m88k_debugger_offset (arg_pointer_rtx, 0))));
#endif
#endif
#if !defined(TARGET_88000) && !defined(ARM_FRAME_RTX) && !defined(SPARC_STACK_ALIGN)
tree fcall;
tree params;
rtx return_val_rtx;
/* call to __builtin_return_address () */
params = tree_cons (NULL_TREE, integer_zero_node, NULL_TREE);
fcall = build_function_call (BuiltinReturnAddress, params);
return_val_rtx = expand_expr (fcall, NULL_RTX, Pmode, 0);
#if 0
/* I would like to do this here, but doesn't seem to work. */
emit_move_insn (return_val_rtx, inner_throw_label);
/* So, for now, just pass throw label to stack unwinder. */
#endif
params = tree_cons (NULL_TREE, make_tree (ptr_type_node,
inner_throw_label), NULL_TREE);
do_function_call (Unwind, params, NULL_TREE);
assemble_external (TREE_OPERAND (Unwind, 0));
emit_barrier ();
#endif
}
/* is called from expand_exception_blocks () to generate the code in a function
to "throw" if anything in the function needs to perform a throw.
expands "throw" as the following pseudo code:
throw:
eh = find_first_exception_match (saved_pc);
if (!eh) goto gotta_rethrow_it;
goto eh;
gotta_rethrow_it:
saved_pc = __builtin_return_address (0);
pop_to_previous_level ();
goto throw;
*/
void
expand_builtin_throw ()
{
tree fcall;
tree params;
rtx return_val_rtx;
rtx gotta_rethrow_it;
rtx gotta_call_terminate;
rtx unwind_and_throw;
rtx goto_unwind_and_throw;
rtx top_of_loop;
rtx unwind_first;
tree t;
if (! doing_eh (0))
return;
if (! throw_used)
return;
params = void_list_node;
t = build_parse_node (CALL_EXPR, get_identifier ("__throw"), params, NULL_TREE);
start_function (decl_tree_cons (NULL_TREE, get_identifier ("static"),
void_list_node),
t, NULL_TREE, NULL_TREE, 0);
store_parm_decls ();
pushlevel (0);
clear_last_expr ();
push_momentary ();
expand_start_bindings (0);
gotta_rethrow_it = gen_label_rtx ();
gotta_call_terminate = gen_label_rtx ();
unwind_and_throw = gen_label_rtx ();
goto_unwind_and_throw = gen_label_rtx ();
top_of_loop = gen_label_rtx ();
unwind_first = gen_label_rtx ();
emit_jump (unwind_first);
emit_label (top_of_loop);
/* search for an exception handler for the saved_pc */
return_val_rtx = do_function_call (FirstExceptionMatch,
tree_cons (NULL_TREE, saved_pc, NULL_TREE),
ptr_type_node);
assemble_external (TREE_OPERAND (FirstExceptionMatch, 0));
/* did we find one? */
emit_cmp_insn (return_val_rtx, const0_rtx, EQ, NULL_RTX,
GET_MODE (return_val_rtx), 0, 0);
/* if not, jump to gotta_rethrow_it */
emit_jump_insn (gen_beq (gotta_rethrow_it));
/* we found it, so jump to it */
emit_indirect_jump (return_val_rtx);
/* code to deal with unwinding and looking for it again */
emit_label (gotta_rethrow_it);
/* call to __builtin_return_address () */
#if defined(ARM_FRAME_RTX) /* was __arm */
/* This replaces a 'call' to __builtin_return_address */
return_val_rtx = gen_reg_rtx (Pmode);
emit_move_insn (return_val_rtx, gen_rtx (MEM, Pmode, plus_constant (hard_frame_pointer_rtx, -4)));
#else
params = tree_cons (NULL_TREE, integer_zero_node, NULL_TREE);
fcall = build_function_call (BuiltinReturnAddress, params);
return_val_rtx = expand_expr (fcall, NULL_RTX, Pmode, 0);
#endif
/* did __builtin_return_address () return a valid address? */
emit_cmp_insn (return_val_rtx, const0_rtx, EQ, NULL_RTX,
GET_MODE (return_val_rtx), 0, 0);
emit_jump_insn (gen_beq (gotta_call_terminate));
#if defined(ARM_FRAME_RTX) /* was __arm */
/* On the ARM, '__builtin_return_address', must have 4
subtracted from it. */
emit_insn (gen_add2_insn (return_val_rtx, GEN_INT (-4)));
/* If we are generating code for an ARM2/ARM3 machine or for an ARM6 in 26 bit
mode, the condition codes must be masked out of the return value, or else
they will confuse BuiltinReturnAddress. This does not apply to ARM6 and
later processors when running in 32 bit mode. */
if (!TARGET_6)
emit_insn (gen_rtx (SET, Pmode, return_val_rtx, gen_rtx (AND, Pmode, return_val_rtx, GEN_INT (0x03fffffc))));
#else
#if !defined(SPARC_STACK_ALIGN) /* was sparc */
/* On the SPARC, __builtin_return_address is already -8, no need to
subtract any more from it. */
return_val_rtx = plus_constant (return_val_rtx, -1);
#endif
#endif
/* yes it did */
t = build_modify_expr (saved_pc, NOP_EXPR, make_tree (ptr_type_node, return_val_rtx));
expand_expr (t, const0_rtx, VOIDmode, 0);
do_unwind (gen_rtx (LABEL_REF, Pmode, top_of_loop));
emit_jump (top_of_loop);
/* no it didn't --> therefore we need to call terminate */
emit_label (gotta_call_terminate);
do_function_call (Terminate, NULL_TREE, NULL_TREE);
assemble_external (TREE_OPERAND (Terminate, 0));
{
rtx ret_val, return_val_rtx;
emit_label (unwind_first);
ret_val = expand_builtin_return_addr (BUILT_IN_RETURN_ADDRESS,
0, hard_frame_pointer_rtx);
/* Set it up so that we continue inside, at the top of the loop. */
emit_move_insn (ret_val, gen_rtx (LABEL_REF, Pmode, top_of_loop));
#ifdef NORMAL_RETURN_ADDR_OFFSET
return_val_rtx = plus_constant (ret_val, -NORMAL_RETURN_ADDR_OFFSET);
if (return_val_rtx != ret_val)
emit_move_insn (ret_val, return_val_rtx);
#endif
/* Fall into epilogue to unwind prologue. */
}
expand_end_bindings (getdecls(), 1, 0);
poplevel (1, 0, 0);
pop_momentary ();
finish_function (lineno, 0, 0);
}
void
expand_start_eh_spec ()
{
start_protect ();
}
void
expand_end_eh_spec (raises)
tree raises;
{
tree expr, second_try;
rtx check = gen_label_rtx ();
rtx cont;
rtx ret = gen_reg_rtx (Pmode);
rtx flag = gen_reg_rtx (TYPE_MODE (integer_type_node));
rtx end = gen_label_rtx ();
expr = make_node (RTL_EXPR);
TREE_TYPE (expr) = void_type_node;
RTL_EXPR_RTL (expr) = const0_rtx;
TREE_SIDE_EFFECTS (expr) = 1;
start_sequence_for_rtl_expr (expr);
cont = gen_label_rtx ();
emit_move_insn (ret, gen_rtx (LABEL_REF, Pmode, cont));
emit_jump (check);
emit_label (cont);
jumpif (make_tree (integer_type_node, flag), end);
do_function_call (Terminate, NULL_TREE, NULL_TREE);
assemble_external (TREE_OPERAND (Terminate, 0));
emit_barrier ();
RTL_EXPR_SEQUENCE (expr) = get_insns ();
end_sequence ();
second_try = expr;
expr = make_node (RTL_EXPR);
TREE_TYPE (expr) = void_type_node;
RTL_EXPR_RTL (expr) = const0_rtx;
TREE_SIDE_EFFECTS (expr) = 1;
start_sequence_for_rtl_expr (expr);
cont = gen_label_rtx ();
emit_move_insn (ret, gen_rtx (LABEL_REF, Pmode, cont));
emit_jump (check);
emit_label (cont);
jumpif (make_tree (integer_type_node, flag), end);
start_protect ();
do_function_call (Unexpected, NULL_TREE, NULL_TREE);
assemble_external (TREE_OPERAND (Unexpected, 0));
emit_barrier ();
end_protect (second_try);
emit_label (check);
emit_move_insn (flag, const1_rtx);
cont = gen_label_rtx ();
while (raises)
{
tree exp;
tree match_type = TREE_VALUE (raises);
if (match_type)
{
/* check TREE_VALUE (raises) here */
exp = saved_throw_value;
exp = tree_cons (NULL_TREE,
build_eh_type_type (match_type),
tree_cons (NULL_TREE,
saved_throw_type,
tree_cons (NULL_TREE, exp, NULL_TREE)));
exp = build_function_call (CatchMatch, exp);
assemble_external (TREE_OPERAND (CatchMatch, 0));
jumpif (exp, cont);
}
raises = TREE_CHAIN (raises);
}
emit_move_insn (flag, const0_rtx);
emit_label (cont);
emit_indirect_jump (ret);
emit_label (end);
RTL_EXPR_SEQUENCE (expr) = get_insns ();
end_sequence ();
end_protect (expr);
}
/* This is called to expand all the toplevel exception handling
finalization for a function. It should only be called once per
function. */
void
expand_exception_blocks ()
{
static rtx funcend;
rtx insns;
start_sequence ();
funcend = gen_label_rtx ();
emit_jump (funcend);
/* expand_null_return (); */
start_sequence ();
/* Add all the catch clauses here. */
emit_insns (catch_clauses);
catch_clauses = NULL_RTX;
expand_leftover_cleanups ();
insns = get_insns ();
end_sequence ();
/* Do this after we expand leftover cleanups, so that the end_protect
that expand_end_eh_spec does will match the right start_protect,
and make sure it comes out before the terminate protected region. */
if (TYPE_RAISES_EXCEPTIONS (TREE_TYPE (current_function_decl)))
{
expand_end_eh_spec (TYPE_RAISES_EXCEPTIONS (TREE_TYPE (current_function_decl)));
push_to_sequence (insns);
/* Now expand any new ones. */
expand_leftover_cleanups ();
insns = get_insns ();
end_sequence ();
}
if (insns)
{
struct ehEntry entry;
/* These are saved for the exception table. */
push_rtl_perm ();
entry.start_label = gen_label_rtx ();
entry.end_label = gen_label_rtx ();
entry.exception_handler_label = gen_label_rtx ();
entry.finalization = TerminateFunctionCall;
entry.context = current_function_decl;
assemble_external (TREE_OPERAND (Terminate, 0));
pop_rtl_from_perm ();
LABEL_PRESERVE_P (entry.start_label) = 1;
LABEL_PRESERVE_P (entry.end_label) = 1;
LABEL_PRESERVE_P (entry.exception_handler_label) = 1;
emit_label (entry.start_label);
emit_insns (insns);
enqueue_eh_entry (&eh_table_output_queue, copy_eh_entry (&entry));
emit_label (entry.exception_handler_label);
expand_expr (entry.finalization, const0_rtx, VOIDmode, 0);
emit_label (entry.end_label);
emit_barrier ();
}
{
/* Mark the end of the stack unwinder. */
rtx unwind_insns;
start_sequence ();
end_eh_unwinder (funcend);
expand_leftover_cleanups ();
unwind_insns = get_insns ();
end_sequence ();
if (unwind_insns)
{
insns = unwind_insns;
emit_insns (insns);
}
}
emit_label (funcend);
/* Only if we had previous insns do we want to emit the jump around
them. If there weren't any, then insns will remain NULL_RTX. */
if (insns)
insns = get_insns ();
end_sequence ();
emit_insns (insns);
}
/* call this to expand a throw statement. This follows the following
algorithm:
1. Allocate space to save the current PC onto the stack.
2. Generate and emit a label and save its address into the
newly allocated stack space since we can't save the pc directly.
3. If this is the first call to throw in this function:
generate a label for the throw block
4. jump to the throw block label. */
void
expand_throw (exp)
tree exp;
{
rtx label;
if (! doing_eh (1))
return;
/* This is the label that represents where in the code we were, when
we got an exception. This needs to be updated when we rethrow an
exception, so that the matching routine knows to search out. */
label = gen_label_rtx ();
emit_label (label);
if (exp)
{
tree throw_type;
tree e;
/* throw expression */
/* First, decay it. */
exp = decay_conversion (exp);
if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
{
throw_type = build_eh_type (exp);
exp = build_reinterpret_cast (ptr_type_node, exp);
}
else
{
/* Make a copy of the thrown object. WP 15.1.5 */
exp = build_new (NULL_TREE, TREE_TYPE (exp),
build_tree_list (NULL_TREE, exp),
0);
if (exp == error_mark_node)
error (" in thrown expression");
throw_type = build_eh_type (build_indirect_ref (exp, NULL_PTR));
}
e = build_modify_expr (saved_throw_type, NOP_EXPR, throw_type);
expand_expr (e, const0_rtx, VOIDmode, 0);
e = build_modify_expr (saved_throw_value, NOP_EXPR, exp);
e = build1 (CLEANUP_POINT_EXPR, TREE_TYPE (e), e);
expand_expr (e, const0_rtx, VOIDmode, 0);
}
else
{
/* rethrow current exception */
/* This part is easy, as we don't have to do anything else. */
}
expand_internal_throw (gen_rtx (LABEL_REF, Pmode, label));
}
void
end_protect_partials () {
while (protect_list)
{
end_protect (TREE_VALUE (protect_list));
protect_list = TREE_CHAIN (protect_list);
}
}
int
might_have_exceptions_p ()
{
if (eh_table_output_queue.head)
return 1;
return 0;
}
/* Output the exception table.
Return the number of handlers. */
void
emit_exception_table ()
{
int count = 0;
extern FILE *asm_out_file;
struct ehEntry *entry;
tree eh_node_decl;
if (! doing_eh (0))
return;
exception_section ();
/* Beginning marker for table. */
assemble_align (GET_MODE_ALIGNMENT (Pmode));
assemble_label ("__EXCEPTION_TABLE__");
output_exception_table_entry (asm_out_file,
const0_rtx, const0_rtx, const0_rtx);
while (entry = dequeue_eh_entry (&eh_table_output_queue))
{
tree context = entry->context;
if (context && ! TREE_ASM_WRITTEN (context))
continue;
count++;
output_exception_table_entry (asm_out_file,
entry->start_label, entry->end_label,
entry->exception_handler_label);
}
/* Ending marker for table. */
assemble_label ("__EXCEPTION_END__");
output_exception_table_entry (asm_out_file,
constm1_rtx, constm1_rtx, constm1_rtx);
}
void
register_exception_table ()
{
rtx addr = gen_rtx (SYMBOL_REF, Pmode, "__EXCEPTION_TABLE__");
#ifdef MARK_LOCAL_ADDRESS
MARK_LOCAL_ADDRESS(addr);
#endif
emit_library_call (gen_rtx (SYMBOL_REF, Pmode, "__register_exceptions"), 0,
VOIDmode, 1,
addr,
Pmode);
}
/* Build a throw expression. */
tree
build_throw (e)
tree e;
{
if (e != error_mark_node)
{
e = build1 (THROW_EXPR, void_type_node, e);
TREE_SIDE_EFFECTS (e) = 1;
TREE_USED (e) = 1;
}
return e;
}
start_eh_unwinder ()
{
start_protect ();
}
end_eh_unwinder (end)
rtx end;
{
tree expr;
rtx return_val_rtx, ret_val, label;
if (! doing_eh (0))
return;
expr = make_node (RTL_EXPR);
TREE_TYPE (expr) = void_type_node;
RTL_EXPR_RTL (expr) = const0_rtx;
TREE_SIDE_EFFECTS (expr) = 1;
start_sequence_for_rtl_expr (expr);
ret_val = expand_builtin_return_addr (BUILT_IN_RETURN_ADDRESS,
0, hard_frame_pointer_rtx);
return_val_rtx = copy_to_reg (ret_val);
#ifdef NORMAL_RETURN_ADDR_OFFSET
return_val_rtx = plus_constant (return_val_rtx, NORMAL_RETURN_ADDR_OFFSET-1);
#else
return_val_rtx = plus_constant (return_val_rtx, -1);
#endif
emit_move_insn (DECL_RTL (saved_pc), return_val_rtx);
#ifdef JUMP_TO_THROW
emit_move_insn (ret_val, gen_rtx (SYMBOL_REF, Pmode, "__throw"));
#else
label = gen_label_rtx ();
emit_move_insn (ret_val, gen_rtx (LABEL_REF, Pmode, label));
#endif
#ifdef NORMAL_RETURN_ADDR_OFFSET
return_val_rtx = plus_constant (ret_val, -NORMAL_RETURN_ADDR_OFFSET);
if (return_val_rtx != ret_val)
emit_move_insn (ret_val, return_val_rtx);
#endif
emit_jump (end);
#ifndef JUMP_TO_THROW
emit_label (label);
do_function_call (Throw, NULL_TREE, NULL_TREE);
#endif
RTL_EXPR_SEQUENCE (expr) = get_insns ();
end_sequence ();
end_protect (expr);
}
|