1 | /*****************************************************************************/ |
2 | /* */ |
3 | /* expr.c */ |
4 | /* */ |
5 | /* Expression evaluation for the ld65 linker */ |
6 | /* */ |
7 | /* */ |
8 | /* */ |
9 | /* (C) 1998-2012, Ullrich von Bassewitz */ |
10 | /* Roemerstrasse 52 */ |
11 | /* D-70794 Filderstadt */ |
12 | /* EMail: uz@cc65.org */ |
13 | /* */ |
14 | /* */ |
15 | /* This software is provided 'as-is', without any expressed or implied */ |
16 | /* warranty. In no event will the authors be held liable for any damages */ |
17 | /* arising from the use of this software. */ |
18 | /* */ |
19 | /* Permission is granted to anyone to use this software for any purpose, */ |
20 | /* including commercial applications, and to alter it and redistribute it */ |
21 | /* freely, subject to the following restrictions: */ |
22 | /* */ |
23 | /* 1. The origin of this software must not be misrepresented; you must not */ |
24 | /* claim that you wrote the original software. If you use this software */ |
25 | /* in a product, an acknowledgment in the product documentation would be */ |
26 | /* appreciated but is not required. */ |
27 | /* 2. Altered source versions must be plainly marked as such, and must not */ |
28 | /* be misrepresented as being the original software. */ |
29 | /* 3. This notice may not be removed or altered from any source */ |
30 | /* distribution. */ |
31 | /* */ |
32 | /*****************************************************************************/ |
33 | |
34 | |
35 | |
36 | /* common */ |
37 | #include "check.h" |
38 | #include "exprdefs.h" |
39 | #include "xmalloc.h" |
40 | |
41 | /* ld65 */ |
42 | #include "global.h" |
43 | #include "error.h" |
44 | #include "fileio.h" |
45 | #include "memarea.h" |
46 | #include "segments.h" |
47 | #include "expr.h" |
48 | |
49 | |
50 | |
51 | /*****************************************************************************/ |
52 | /* Code */ |
53 | /*****************************************************************************/ |
54 | |
55 | |
56 | |
57 | ExprNode* NewExprNode (ObjData* O, unsigned char Op) |
58 | /* Create a new expression node */ |
59 | { |
60 | /* Allocate fresh memory */ |
61 | ExprNode* N = xmalloc (sizeof (ExprNode)); |
62 | N->Op = Op; |
63 | N->Left = 0; |
64 | N->Right = 0; |
65 | N->Obj = O; |
66 | N->V.IVal = 0; |
67 | |
68 | return N; |
69 | } |
70 | |
71 | |
72 | |
73 | static void FreeExprNode (ExprNode* E) |
74 | /* Free a node */ |
75 | { |
76 | /* Free the memory */ |
77 | xfree (E); |
78 | } |
79 | |
80 | |
81 | |
82 | void FreeExpr (ExprNode* Root) |
83 | /* Free the expression, Root is pointing to. */ |
84 | { |
85 | if (Root) { |
86 | FreeExpr (Root->Left); |
87 | FreeExpr (Root->Right); |
88 | FreeExprNode (Root); |
89 | } |
90 | } |
91 | |
92 | |
93 | |
94 | int IsConstExpr (ExprNode* Root) |
95 | /* Return true if the given expression is a constant expression, that is, one |
96 | ** with no references to external symbols. |
97 | */ |
98 | { |
99 | int Const; |
100 | Export* E; |
101 | Section* S; |
102 | MemoryArea* M; |
103 | |
104 | if (EXPR_IS_LEAF (Root->Op)) { |
105 | switch (Root->Op) { |
106 | |
107 | case EXPR_LITERAL: |
108 | return 1; |
109 | |
110 | case EXPR_SYMBOL: |
111 | /* Get the referenced export */ |
112 | E = GetExprExport (Root); |
113 | /* If this export has a mark set, we've already encountered it. |
114 | ** This means that the export is used to define it's own value, |
115 | ** which in turn means, that we have a circular reference. |
116 | */ |
117 | if (ExportHasMark (E)) { |
118 | CircularRefError (E); |
119 | Const = 0; |
120 | } else { |
121 | MarkExport (E); |
122 | Const = IsConstExport (E); |
123 | UnmarkExport (E); |
124 | } |
125 | return Const; |
126 | |
127 | case EXPR_SECTION: |
128 | /* A section expression is const if the segment it is in is |
129 | ** not relocatable and already placed. |
130 | */ |
131 | S = GetExprSection (Root); |
132 | M = S->Seg->MemArea; |
133 | return M != 0 && (M->Flags & MF_PLACED) != 0 && !M->Relocatable; |
134 | |
135 | case EXPR_SEGMENT: |
136 | /* A segment is const if it is not relocatable and placed */ |
137 | M = Root->V.Seg->MemArea; |
138 | return M != 0 && (M->Flags & MF_PLACED) != 0 && !M->Relocatable; |
139 | |
140 | case EXPR_MEMAREA: |
141 | /* A memory area is const if it is not relocatable and placed */ |
142 | return !Root->V.Mem->Relocatable && |
143 | (Root->V.Mem->Flags & MF_PLACED); |
144 | |
145 | default: |
146 | /* Anything else is not const */ |
147 | return 0; |
148 | |
149 | } |
150 | |
151 | } else if (EXPR_IS_UNARY (Root->Op)) { |
152 | |
153 | SegExprDesc D; |
154 | |
155 | /* Special handling for the BANK pseudo function */ |
156 | switch (Root->Op) { |
157 | |
158 | case EXPR_BANK: |
159 | /* Get segment references for the expression */ |
160 | GetSegExprVal (Root->Left, &D); |
161 | |
162 | /* The expression is const if the expression contains exactly |
163 | ** one segment that is assigned to a memory area which has a |
164 | ** bank attribute that is constant. |
165 | */ |
166 | return (D.TooComplex == 0 && |
167 | D.Seg != 0 && |
168 | D.Seg->MemArea != 0 && |
169 | D.Seg->MemArea->BankExpr != 0 && |
170 | IsConstExpr (D.Seg->MemArea->BankExpr)); |
171 | |
172 | default: |
173 | /* All others handled normal */ |
174 | return IsConstExpr (Root->Left); |
175 | |
176 | } |
177 | |
178 | } else { |
179 | |
180 | /* We must handle shortcut boolean expressions here */ |
181 | switch (Root->Op) { |
182 | |
183 | case EXPR_BOOLAND: |
184 | if (IsConstExpr (Root->Left)) { |
185 | /* lhs is const, if it is zero, don't eval right */ |
186 | if (GetExprVal (Root->Left) == 0) { |
187 | return 1; |
188 | } else { |
189 | return IsConstExpr (Root->Right); |
190 | } |
191 | } else { |
192 | /* lhs not const --> tree not const */ |
193 | return 0; |
194 | } |
195 | break; |
196 | |
197 | case EXPR_BOOLOR: |
198 | if (IsConstExpr (Root->Left)) { |
199 | /* lhs is const, if it is not zero, don't eval right */ |
200 | if (GetExprVal (Root->Left) != 0) { |
201 | return 1; |
202 | } else { |
203 | return IsConstExpr (Root->Right); |
204 | } |
205 | } else { |
206 | /* lhs not const --> tree not const */ |
207 | return 0; |
208 | } |
209 | break; |
210 | |
211 | default: |
212 | /* All others are handled normal */ |
213 | return IsConstExpr (Root->Left) && IsConstExpr (Root->Right); |
214 | } |
215 | } |
216 | } |
217 | |
218 | |
219 | |
220 | Import* GetExprImport (ExprNode* Expr) |
221 | /* Get the import data structure for a symbol expression node */ |
222 | { |
223 | /* Check that this is really a symbol */ |
224 | PRECONDITION (Expr->Op == EXPR_SYMBOL); |
225 | |
226 | /* If we have an object file, get the import from it, otherwise |
227 | ** (internally generated expressions), get the import from the |
228 | ** import pointer. |
229 | */ |
230 | if (Expr->Obj) { |
231 | /* Return the Import */ |
232 | return GetObjImport (Expr->Obj, Expr->V.ImpNum); |
233 | } else { |
234 | return Expr->V.Imp; |
235 | } |
236 | } |
237 | |
238 | |
239 | |
240 | Export* GetExprExport (ExprNode* Expr) |
241 | /* Get the exported symbol for a symbol expression node */ |
242 | { |
243 | /* Check that this is really a symbol */ |
244 | PRECONDITION (Expr->Op == EXPR_SYMBOL); |
245 | |
246 | /* Return the export for an import*/ |
247 | return GetExprImport (Expr)->Exp; |
248 | } |
249 | |
250 | |
251 | |
252 | Section* GetExprSection (ExprNode* Expr) |
253 | /* Get the segment for a section expression node */ |
254 | { |
255 | /* Check that this is really a section node */ |
256 | PRECONDITION (Expr->Op == EXPR_SECTION); |
257 | |
258 | /* If we have an object file, get the section from it, otherwise |
259 | ** (internally generated expressions), get the section from the |
260 | ** section pointer. |
261 | */ |
262 | if (Expr->Obj) { |
263 | /* Return the export */ |
264 | return CollAt (&Expr->Obj->Sections, Expr->V.SecNum); |
265 | } else { |
266 | return Expr->V.Sec; |
267 | } |
268 | } |
269 | |
270 | |
271 | |
272 | long GetExprVal (ExprNode* Expr) |
273 | /* Get the value of a constant expression */ |
274 | { |
275 | long Right; |
276 | long Left; |
277 | long Val; |
278 | Section* S; |
279 | Export* E; |
280 | SegExprDesc D; |
281 | |
282 | switch (Expr->Op) { |
283 | |
284 | case EXPR_LITERAL: |
285 | return Expr->V.IVal; |
286 | |
287 | case EXPR_SYMBOL: |
288 | /* Get the referenced export */ |
289 | E = GetExprExport (Expr); |
290 | /* If this export has a mark set, we've already encountered it. |
291 | ** This means that the export is used to define it's own value, |
292 | ** which in turn means, that we have a circular reference. |
293 | */ |
294 | if (ExportHasMark (E)) { |
295 | CircularRefError (E); |
296 | Val = 0; |
297 | } else { |
298 | MarkExport (E); |
299 | Val = GetExportVal (E); |
300 | UnmarkExport (E); |
301 | } |
302 | return Val; |
303 | |
304 | case EXPR_SECTION: |
305 | S = GetExprSection (Expr); |
306 | return S->Offs + S->Seg->PC; |
307 | |
308 | case EXPR_SEGMENT: |
309 | return Expr->V.Seg->PC; |
310 | |
311 | case EXPR_MEMAREA: |
312 | return Expr->V.Mem->Start; |
313 | |
314 | case EXPR_PLUS: |
315 | return GetExprVal (Expr->Left) + GetExprVal (Expr->Right); |
316 | |
317 | case EXPR_MINUS: |
318 | return GetExprVal (Expr->Left) - GetExprVal (Expr->Right); |
319 | |
320 | case EXPR_MUL: |
321 | return GetExprVal (Expr->Left) * GetExprVal (Expr->Right); |
322 | |
323 | case EXPR_DIV: |
324 | Left = GetExprVal (Expr->Left); |
325 | Right = GetExprVal (Expr->Right); |
326 | if (Right == 0) { |
327 | Error ("Division by zero" ); |
328 | } |
329 | return Left / Right; |
330 | |
331 | case EXPR_MOD: |
332 | Left = GetExprVal (Expr->Left); |
333 | Right = GetExprVal (Expr->Right); |
334 | if (Right == 0) { |
335 | Error ("Modulo operation with zero" ); |
336 | } |
337 | return Left % Right; |
338 | |
339 | case EXPR_OR: |
340 | return GetExprVal (Expr->Left) | GetExprVal (Expr->Right); |
341 | |
342 | case EXPR_XOR: |
343 | return GetExprVal (Expr->Left) ^ GetExprVal (Expr->Right); |
344 | |
345 | case EXPR_AND: |
346 | return GetExprVal (Expr->Left) & GetExprVal (Expr->Right); |
347 | |
348 | case EXPR_SHL: |
349 | return GetExprVal (Expr->Left) << GetExprVal (Expr->Right); |
350 | |
351 | case EXPR_SHR: |
352 | return GetExprVal (Expr->Left) >> GetExprVal (Expr->Right); |
353 | |
354 | case EXPR_EQ: |
355 | return (GetExprVal (Expr->Left) == GetExprVal (Expr->Right)); |
356 | |
357 | case EXPR_NE: |
358 | return (GetExprVal (Expr->Left) != GetExprVal (Expr->Right)); |
359 | |
360 | case EXPR_LT: |
361 | return (GetExprVal (Expr->Left) < GetExprVal (Expr->Right)); |
362 | |
363 | case EXPR_GT: |
364 | return (GetExprVal (Expr->Left) > GetExprVal (Expr->Right)); |
365 | |
366 | case EXPR_LE: |
367 | return (GetExprVal (Expr->Left) <= GetExprVal (Expr->Right)); |
368 | |
369 | case EXPR_GE: |
370 | return (GetExprVal (Expr->Left) >= GetExprVal (Expr->Right)); |
371 | |
372 | case EXPR_BOOLAND: |
373 | return GetExprVal (Expr->Left) && GetExprVal (Expr->Right); |
374 | |
375 | case EXPR_BOOLOR: |
376 | return GetExprVal (Expr->Left) || GetExprVal (Expr->Right); |
377 | |
378 | case EXPR_BOOLXOR: |
379 | return (GetExprVal (Expr->Left) != 0) ^ (GetExprVal (Expr->Right) != 0); |
380 | |
381 | case EXPR_MAX: |
382 | Left = GetExprVal (Expr->Left); |
383 | Right = GetExprVal (Expr->Right); |
384 | return (Left > Right)? Left : Right; |
385 | |
386 | case EXPR_MIN: |
387 | Left = GetExprVal (Expr->Left); |
388 | Right = GetExprVal (Expr->Right); |
389 | return (Left < Right)? Left : Right; |
390 | |
391 | case EXPR_UNARY_MINUS: |
392 | return -GetExprVal (Expr->Left); |
393 | |
394 | case EXPR_NOT: |
395 | return ~GetExprVal (Expr->Left); |
396 | |
397 | case EXPR_SWAP: |
398 | Left = GetExprVal (Expr->Left); |
399 | return ((Left >> 8) & 0x00FF) | ((Left << 8) & 0xFF00); |
400 | |
401 | case EXPR_BOOLNOT: |
402 | return !GetExprVal (Expr->Left); |
403 | |
404 | case EXPR_BANK: |
405 | GetSegExprVal (Expr->Left, &D); |
406 | if (D.TooComplex || D.Seg == 0) { |
407 | Error ("Argument for .BANK is not segment relative or too complex" ); |
408 | } |
409 | if (D.Seg->MemArea == 0) { |
410 | Error ("Segment '%s' is referenced by .BANK but " |
411 | "not assigned to a memory area" , |
412 | GetString (D.Seg->Name)); |
413 | } |
414 | if (D.Seg->MemArea->BankExpr == 0) { |
415 | Error ("Memory area '%s' is referenced by .BANK but " |
416 | "has no BANK attribute" , |
417 | GetString (D.Seg->MemArea->Name)); |
418 | } |
419 | return GetExprVal (D.Seg->MemArea->BankExpr); |
420 | |
421 | case EXPR_BYTE0: |
422 | return GetExprVal (Expr->Left) & 0xFF; |
423 | |
424 | case EXPR_BYTE1: |
425 | return (GetExprVal (Expr->Left) >> 8) & 0xFF; |
426 | |
427 | case EXPR_BYTE2: |
428 | return (GetExprVal (Expr->Left) >> 16) & 0xFF; |
429 | |
430 | case EXPR_BYTE3: |
431 | return (GetExprVal (Expr->Left) >> 24) & 0xFF; |
432 | |
433 | case EXPR_WORD0: |
434 | return GetExprVal (Expr->Left) & 0xFFFF; |
435 | |
436 | case EXPR_WORD1: |
437 | return (GetExprVal (Expr->Left) >> 16) & 0xFFFF; |
438 | |
439 | case EXPR_FARADDR: |
440 | return GetExprVal (Expr->Left) & 0xFFFFFF; |
441 | |
442 | case EXPR_DWORD: |
443 | return GetExprVal (Expr->Left) & 0xFFFFFFFF; |
444 | |
445 | case EXPR_NEARADDR: |
446 | /* Assembler was expected to validate this truncation. */ |
447 | return GetExprVal (Expr->Left) & 0xFFFF; |
448 | |
449 | default: |
450 | Internal ("Unknown expression Op type: %u" , Expr->Op); |
451 | /* NOTREACHED */ |
452 | return 0; |
453 | } |
454 | } |
455 | |
456 | |
457 | |
458 | static void GetSegExprValInternal (ExprNode* Expr, SegExprDesc* D, int Sign) |
459 | /* Check if the given expression consists of a segment reference and only |
460 | ** constant values, additions and subtractions. If anything else is found, |
461 | ** set D->TooComplex to true. |
462 | ** Internal, recursive routine. |
463 | */ |
464 | { |
465 | Export* E; |
466 | |
467 | switch (Expr->Op) { |
468 | |
469 | case EXPR_LITERAL: |
470 | D->Val += (Sign * Expr->V.IVal); |
471 | break; |
472 | |
473 | case EXPR_SYMBOL: |
474 | /* Get the referenced export */ |
475 | E = GetExprExport (Expr); |
476 | /* If this export has a mark set, we've already encountered it. |
477 | ** This means that the export is used to define it's own value, |
478 | ** which in turn means, that we have a circular reference. |
479 | */ |
480 | if (ExportHasMark (E)) { |
481 | CircularRefError (E); |
482 | } else { |
483 | MarkExport (E); |
484 | GetSegExprValInternal (E->Expr, D, Sign); |
485 | UnmarkExport (E); |
486 | } |
487 | break; |
488 | |
489 | case EXPR_SECTION: |
490 | if (D->Seg) { |
491 | /* We cannot handle more than one segment reference in o65 */ |
492 | D->TooComplex = 1; |
493 | } else { |
494 | /* Get the section from the expression */ |
495 | Section* S = GetExprSection (Expr); |
496 | /* Remember the segment reference */ |
497 | D->Seg = S->Seg; |
498 | /* Add the offset of the section to the constant value */ |
499 | D->Val += Sign * (S->Offs + D->Seg->PC); |
500 | } |
501 | break; |
502 | |
503 | case EXPR_SEGMENT: |
504 | if (D->Seg) { |
505 | /* We cannot handle more than one segment reference in o65 */ |
506 | D->TooComplex = 1; |
507 | } else { |
508 | /* Remember the segment reference */ |
509 | D->Seg = Expr->V.Seg; |
510 | /* Add the offset of the segment to the constant value */ |
511 | D->Val += (Sign * D->Seg->PC); |
512 | } |
513 | break; |
514 | |
515 | case EXPR_PLUS: |
516 | GetSegExprValInternal (Expr->Left, D, Sign); |
517 | GetSegExprValInternal (Expr->Right, D, Sign); |
518 | break; |
519 | |
520 | case EXPR_MINUS: |
521 | GetSegExprValInternal (Expr->Left, D, Sign); |
522 | GetSegExprValInternal (Expr->Right, D, -Sign); |
523 | break; |
524 | |
525 | default: |
526 | /* Expression contains illegal operators */ |
527 | D->TooComplex = 1; |
528 | break; |
529 | |
530 | } |
531 | } |
532 | |
533 | |
534 | |
535 | void GetSegExprVal (ExprNode* Expr, SegExprDesc* D) |
536 | /* Check if the given expression consists of a segment reference and only |
537 | ** constant values, additions and subtractions. If anything else is found, |
538 | ** set D->TooComplex to true. The function will initialize D. |
539 | */ |
540 | { |
541 | /* Initialize the given structure */ |
542 | D->Val = 0; |
543 | D->TooComplex = 0; |
544 | D->Seg = 0; |
545 | |
546 | /* Call our recursive calculation routine */ |
547 | GetSegExprValInternal (Expr, D, 1); |
548 | } |
549 | |
550 | |
551 | |
552 | ExprNode* LiteralExpr (long Val, ObjData* O) |
553 | /* Return an expression tree that encodes the given literal value */ |
554 | { |
555 | ExprNode* Expr = NewExprNode (O, EXPR_LITERAL); |
556 | Expr->V.IVal = Val; |
557 | return Expr; |
558 | } |
559 | |
560 | |
561 | |
562 | ExprNode* MemoryExpr (MemoryArea* Mem, long Offs, ObjData* O) |
563 | /* Return an expression tree that encodes an offset into a memory area */ |
564 | { |
565 | ExprNode* Root; |
566 | |
567 | ExprNode* Expr = NewExprNode (O, EXPR_MEMAREA); |
568 | Expr->V.Mem = Mem; |
569 | |
570 | if (Offs != 0) { |
571 | Root = NewExprNode (O, EXPR_PLUS); |
572 | Root->Left = Expr; |
573 | Root->Right = LiteralExpr (Offs, O); |
574 | } else { |
575 | Root = Expr; |
576 | } |
577 | |
578 | return Root; |
579 | } |
580 | |
581 | |
582 | |
583 | ExprNode* SegmentExpr (Segment* Seg, long Offs, ObjData* O) |
584 | /* Return an expression tree that encodes an offset into a segment */ |
585 | { |
586 | ExprNode* Root; |
587 | |
588 | ExprNode* Expr = NewExprNode (O, EXPR_SEGMENT); |
589 | Expr->V.Seg = Seg; |
590 | |
591 | if (Offs != 0) { |
592 | Root = NewExprNode (O, EXPR_PLUS); |
593 | Root->Left = Expr; |
594 | Root->Right = LiteralExpr (Offs, O); |
595 | } else { |
596 | Root = Expr; |
597 | } |
598 | |
599 | return Root; |
600 | } |
601 | |
602 | |
603 | |
604 | ExprNode* SectionExpr (Section* Sec, long Offs, ObjData* O) |
605 | /* Return an expression tree that encodes an offset into a section */ |
606 | { |
607 | ExprNode* Root; |
608 | |
609 | ExprNode* Expr = NewExprNode (O, EXPR_SECTION); |
610 | Expr->V.Sec = Sec; |
611 | |
612 | if (Offs != 0) { |
613 | Root = NewExprNode (O, EXPR_PLUS); |
614 | Root->Left = Expr; |
615 | Root->Right = LiteralExpr (Offs, O); |
616 | } else { |
617 | Root = Expr; |
618 | } |
619 | |
620 | return Root; |
621 | } |
622 | |
623 | |
624 | |
625 | ExprNode* ReadExpr (FILE* F, ObjData* O) |
626 | /* Read an expression from the given file */ |
627 | { |
628 | ExprNode* Expr; |
629 | |
630 | /* Read the node tag and handle NULL nodes */ |
631 | unsigned char Op = Read8 (F); |
632 | if (Op == EXPR_NULL) { |
633 | return 0; |
634 | } |
635 | |
636 | /* Create a new node */ |
637 | Expr = NewExprNode (O, Op); |
638 | |
639 | /* Check the tag and handle the different expression types */ |
640 | if (EXPR_IS_LEAF (Op)) { |
641 | switch (Op) { |
642 | |
643 | case EXPR_LITERAL: |
644 | Expr->V.IVal = Read32Signed (F); |
645 | break; |
646 | |
647 | case EXPR_SYMBOL: |
648 | /* Read the import number */ |
649 | Expr->V.ImpNum = ReadVar (F); |
650 | break; |
651 | |
652 | case EXPR_SECTION: |
653 | /* Read the section number */ |
654 | Expr->V.SecNum = ReadVar (F); |
655 | break; |
656 | |
657 | default: |
658 | Error ("Invalid expression op: %02X" , Op); |
659 | |
660 | } |
661 | |
662 | } else { |
663 | |
664 | /* Not a leaf node */ |
665 | Expr->Left = ReadExpr (F, O); |
666 | Expr->Right = ReadExpr (F, O); |
667 | |
668 | } |
669 | |
670 | /* Return the tree */ |
671 | return Expr; |
672 | } |
673 | |
674 | |
675 | |
676 | int EqualExpr (ExprNode* E1, ExprNode* E2) |
677 | /* Check if two expressions are identical. */ |
678 | { |
679 | /* If one pointer is NULL, both must be NULL */ |
680 | if ((E1 == 0) ^ (E2 == 0)) { |
681 | return 0; |
682 | } |
683 | if (E1 == 0) { |
684 | return 1; |
685 | } |
686 | |
687 | /* Both pointers not NULL, check OP */ |
688 | if (E1->Op != E2->Op) { |
689 | return 0; |
690 | } |
691 | |
692 | /* OPs are identical, check data for leafs, or subtrees */ |
693 | switch (E1->Op) { |
694 | |
695 | case EXPR_LITERAL: |
696 | /* Value must be identical */ |
697 | return (E1->V.IVal == E2->V.IVal); |
698 | |
699 | case EXPR_SYMBOL: |
700 | /* Import must be identical */ |
701 | return (GetExprImport (E1) == GetExprImport (E2)); |
702 | |
703 | case EXPR_SECTION: |
704 | /* Section must be identical */ |
705 | return (GetExprSection (E1) == GetExprSection (E2)); |
706 | |
707 | case EXPR_SEGMENT: |
708 | /* Segment must be identical */ |
709 | return (E1->V.Seg == E2->V.Seg); |
710 | |
711 | case EXPR_MEMAREA: |
712 | /* Memory area must be identical */ |
713 | return (E1->V.Mem == E2->V.Mem); |
714 | |
715 | default: |
716 | /* Not a leaf node */ |
717 | return EqualExpr (E1->Left, E2->Left) && EqualExpr (E1->Right, E2->Right); |
718 | } |
719 | |
720 | } |
721 | |