1 /*****************************************************************************/
5 /* Module to handle the o65 binary format */
9 /* (C) 1999 Ullrich von Bassewitz */
11 /* D-70597 Stuttgart */
12 /* EMail: uz@musoftware.de */
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. */
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: */
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 */
32 /*****************************************************************************/
41 #include "../common/version.h"
42 #include "../common/xmalloc.h"
53 /*****************************************************************************/
55 /*****************************************************************************/
59 /* Header mode bits */
60 #define MF_SIZE_32BIT 0x2000 /* All size words are 32bit */
61 #define MF_CPU_816 0x8000 /* Executable is for 65816 */
63 /* The four o65 segment types. Note: These values are identical to the values
64 * needed for the segmentID in the o65 spec.
66 #define O65SEG_UNDEF 0x00
67 #define O65SEG_ABS 0x01
68 #define O65SEG_TEXT 0x02
69 #define O65SEG_DATA 0x03
70 #define O65SEG_BSS 0x04
71 #define O65SEG_ZP 0x05
73 /* Relocation type codes for the o65 format */
74 #define O65RELOC_WORD 0x80
75 #define O65RELOC_HIGH 0x40
76 #define O65RELOC_LOW 0x20
77 #define O65RELOC_SEGADR 0xc0
78 #define O65RELOC_SEG 0xa0
80 /* O65 executable file header */
81 typedef struct O65Header_ O65Header;
83 unsigned Version; /* Version number for o65 format */
84 unsigned Mode; /* Mode word */
85 unsigned long TextBase; /* Base address of text segment */
86 unsigned long TextSize; /* Size of text segment */
87 unsigned long DataBase; /* Base of data segment */
88 unsigned long DataSize; /* Size of data segment */
89 unsigned long BssBase; /* Base of bss segment */
90 unsigned long BssSize; /* Size of bss segment */
91 unsigned long ZPBase; /* Base of zeropage segment */
92 unsigned long ZPSize; /* Size of zeropage segment */
93 unsigned long StackSize; /* Requested stack size */
97 typedef struct O65Option_ O65Option;
99 O65Option* Next; /* Next in option list */
100 unsigned char Type; /* Type of option */
101 unsigned char Len; /* Data length */
102 unsigned char Data [1]; /* Data, dynamically allocated */
105 /* A o65 relocation table */
106 #define RELOC_BLOCKSIZE 4096
107 typedef struct O65RelocTab_ O65RelocTab;
108 struct O65RelocTab_ {
109 unsigned Size; /* Size of the table */
110 unsigned Fill; /* Amount used */
111 unsigned char* Buf; /* Buffer, dynamically allocated */
114 /* Structure describing the format */
116 O65Header Header; /* File header */
117 O65Option* Options; /* List of file options */
118 ExtSymTab* Exports; /* Table with exported symbols */
119 ExtSymTab* Imports; /* Table with imported symbols */
120 unsigned Undef; /* Count of undefined symbols */
121 FILE* F; /* The file we're writing to */
122 char* Filename; /* Name of the output file */
123 O65RelocTab* TextReloc; /* Relocation table for text segment */
124 O65RelocTab* DataReloc; /* Relocation table for data segment */
126 unsigned TextCount; /* Number of segments assigned to .text */
127 SegDesc** TextSeg; /* Array of text segments */
128 unsigned DataCount; /* Number of segments assigned to .data */
129 SegDesc** DataSeg; /* Array of data segments */
130 unsigned BssCount; /* Number of segments assigned to .bss */
131 SegDesc** BssSeg; /* Array of bss segments */
132 unsigned ZPCount; /* Number of segments assigned to .zp */
133 SegDesc** ZPSeg; /* Array of zp segments */
135 /* Temporary data for writing segments */
136 unsigned long SegSize;
137 O65RelocTab* CurReloc;
141 /* Structure for parsing expression trees */
142 typedef struct ExprDesc_ ExprDesc;
144 O65Desc* D; /* File format descriptor */
145 long Val; /* The offset value */
146 int TooComplex; /* Expression too complex */
147 Section* SegRef; /* Section referenced if any */
148 ExtSym* ExtRef; /* External reference if any */
153 /*****************************************************************************/
154 /* Helper functions */
155 /*****************************************************************************/
159 static void WriteSize (const O65Desc* D, unsigned long Val)
160 /* Write a "size" word to the file */
162 if (D->Header.Mode & MF_SIZE_32BIT) {
165 Write16 (D->F, (unsigned) Val);
171 static unsigned O65SegType (const SegDesc* S)
172 /* Map our own segment types into something o65 compatible */
174 /* Check the segment type. Readonly segments are assign to the o65
175 * text segment, writeable segments that contain data are assigned
176 * to data, bss and zp segments are handled respectively.
177 * Beware: Zeropage segments have the SF_BSS flag set, so be sure
178 * to check SF_ZP first.
180 if (S->Flags & SF_RO) {
182 } else if (S->Flags & SF_ZP) {
184 } else if (S->Flags & SF_BSS) {
193 /*****************************************************************************/
194 /* Expression handling */
195 /*****************************************************************************/
199 static void O65ParseExpr (ExprNode* Expr, ExprDesc* D, int Sign)
200 /* Extract and evaluate all constant factors in an subtree that has only
201 * additions and subtractions. If anything other than additions and
202 * subtractions are found, D->TooComplex is set to true.
211 D->Val -= Expr->V.Val;
213 D->Val += Expr->V.Val;
218 /* Get the referenced Export */
219 E = GetExprExport (Expr);
220 /* If this export has a mark set, we've already encountered it.
221 * This means that the export is used to define it's own value,
222 * which in turn means, that we have a circular reference.
224 if (ExportHasMark (E)) {
225 CircularRefError (E);
226 } else if (E->Expr == 0) {
227 /* Dummy export, must be an o65 imported symbol */
228 ExtSym* S = O65GetImport (D->D, E->Name);
231 /* We cannot have more than one external reference in o65 */
234 /* Remember the external reference */
239 O65ParseExpr (E->Expr, D, Sign);
246 /* We cannot handle more than one segment reference in o65 */
249 /* Remember the segment reference */
250 D->SegRef = GetExprSection (Expr);
255 O65ParseExpr (Expr->Left, D, Sign);
256 O65ParseExpr (Expr->Right, D, Sign);
260 O65ParseExpr (Expr->Left, D, Sign);
261 O65ParseExpr (Expr->Right, D, -Sign);
265 /* Expression contains illegal operators */
274 /*****************************************************************************/
275 /* Relocation tables */
276 /*****************************************************************************/
280 static O65RelocTab* NewO65RelocTab (void)
281 /* Create a new relocation table */
283 /* Allocate a new structure */
284 O65RelocTab* R = xmalloc (sizeof (O65RelocTab));
286 /* Initialize the data */
287 R->Size = RELOC_BLOCKSIZE;
289 R->Buf = xmalloc (RELOC_BLOCKSIZE);
291 /* Return the created struct */
297 static void FreeO65RelocTab (O65RelocTab* R)
298 /* Free a relocation table */
306 static void O65RelocPutByte (O65RelocTab* R, unsigned B)
307 /* Put the byte into the relocation table */
309 /* Do we have enough space in the buffer? */
310 if (R->Fill == R->Size) {
311 /* We need to grow the buffer */
312 unsigned char* NewBuf = xmalloc (R->Size + RELOC_BLOCKSIZE);
313 memcpy (NewBuf, R->Buf, R->Size);
318 /* Put the byte into the buffer */
319 R->Buf [R->Fill++] = (unsigned char) B;
324 static void O65RelocPutWord (O65RelocTab* R, unsigned W)
325 /* Put a word into the relocation table */
327 O65RelocPutByte (R, W);
328 O65RelocPutByte (R, W >> 8);
333 static void O65WriteReloc (O65RelocTab* R, FILE* F)
334 /* Write the relocation table to the given file */
336 WriteData (F, R->Buf, R->Fill);
341 /*****************************************************************************/
342 /* Option handling */
343 /*****************************************************************************/
347 static O65Option* NewO65Option (unsigned Type, const void* Data, unsigned DataLen)
348 /* Allocate and initialize a new option struct */
352 /* Check the length */
353 CHECK (DataLen <= 253);
355 /* Allocate memory */
356 O = xmalloc (sizeof (O65Option) - 1 + DataLen);
358 /* Initialize the structure */
362 memcpy (O->Data, Data, DataLen);
364 /* Return the created struct */
370 static void FreeO65Option (O65Option* O)
371 /* Free an O65Option struct */
378 /*****************************************************************************/
379 /* Subroutines to write o65 sections */
380 /*****************************************************************************/
384 static void O65WriteHeader (O65Desc* D)
385 /* Write the header of the executable to the given file */
387 static unsigned char Trailer [5] = {
388 0x01, 0x00, 0x6F, 0x36, 0x35
394 /* Write the fixed header */
395 WriteData (D->F, Trailer, sizeof (Trailer));
396 Write8 (D->F, D->Header.Version);
397 Write16 (D->F, D->Header.Mode);
398 WriteSize (D, D->Header.TextBase);
399 WriteSize (D, D->Header.TextSize);
400 WriteSize (D, D->Header.DataBase);
401 WriteSize (D, D->Header.DataSize);
402 WriteSize (D, D->Header.BssBase);
403 WriteSize (D, D->Header.BssSize);
404 WriteSize (D, D->Header.ZPBase);
405 WriteSize (D, D->Header.ZPSize);
406 WriteSize (D, D->Header.StackSize);
408 /* Write the options */
411 Write8 (D->F, O->Len + 2); /* Account for len and type bytes */
412 Write8 (D->F, O->Type);
414 WriteData (D->F, O->Data, O->Len);
419 /* Write the end-of-options byte */
425 static unsigned O65WriteExpr (ExprNode* E, int Signed, unsigned Size,
426 unsigned long Offs, void* Data)
427 /* Called from SegWrite for an expression. Evaluate the expression, check the
428 * range and write the expression value to the file, update the relocation
436 unsigned char RelocType;
438 /* Cast the Data pointer to its real type, an O65Desc */
439 O65Desc* D = (O65Desc*) Data;
441 /* Check for a constant expression */
442 if (IsConstExpr (E)) {
443 /* Write out the constant expression */
444 return SegWriteConstExpr (((O65Desc*)Data)->F, E, Signed, Size);
447 /* We have a relocatable expression that needs a relocation table entry.
448 * Calculate the number of bytes between this entry and the last one, and
449 * setup all necessary intermediate bytes in the relocation table.
451 Offs += D->SegSize; /* Calulate full offset */
452 Diff = ((long) Offs) - D->LastOffs;
453 while (Diff > 0xFE) {
454 O65RelocPutByte (D->CurReloc, 0xFF);
457 O65RelocPutByte (D->CurReloc, (unsigned char) Diff);
459 /* Remember this offset for the next time */
462 /* Determine the expression to relocate */
464 if (E->Op == EXPR_LOBYTE || E->Op == EXPR_HIBYTE) {
465 /* Use the real expression */
469 /* Initialize the descriptor for expression parsing */
476 /* Recursively collect information about this expression */
477 O65ParseExpr (Expr, &ED, 1);
479 /* We cannot handle both, an imported symbol and a segment ref */
480 if (ED.SegRef != 0 && ED.ExtRef != 0) {
484 /* Bail out if we cannot handle the expression */
486 return SEG_EXPR_TOO_COMPLEX;
489 /* Safety: Check that we are really referencing a symbol or a segment */
490 CHECK (ED.SegRef != 0 || ED.ExtRef != 0);
492 /* Write out the offset that goes into the segment. */
494 if (E->Op == EXPR_LOBYTE) {
496 } else if (E->Op == EXPR_HIBYTE) {
497 BinVal = (BinVal >> 8) & 0x00FF;
499 WriteVal (D->F, BinVal, Size);
501 /* Determine the actual type of relocation entry needed from the
502 * information gathered about the expression.
504 if (E->Op == EXPR_LOBYTE) {
505 RelocType = O65RELOC_LOW;
506 } else if (E->Op == EXPR_HIBYTE) {
507 RelocType = O65RELOC_HIGH;
512 RelocType = O65RELOC_LOW;
516 RelocType = O65RELOC_WORD;
520 RelocType = O65RELOC_SEGADR;
524 /* 4 byte expression not supported by o65 */
525 return SEG_EXPR_TOO_COMPLEX;
528 Internal ("O65WriteExpr: Invalid expression size: %u", Size);
529 RelocType = 0; /* Avoid gcc warnings */
533 /* Determine which segment we're referencing */
535 /* Imported symbol */
536 RelocType |= O65SEG_UNDEF;
537 O65RelocPutByte (D->CurReloc, RelocType);
538 /* Put the number of the imported symbol into the table */
539 O65RelocPutWord (D->CurReloc, ExtSymNum (ED.ExtRef));
541 /* Segment reference */
553 static void O65WriteSeg (O65Desc* D, SegDesc** Seg, unsigned Count, int DoWrite)
554 /* Write one segment to the o65 output file */
559 /* Initialize variables */
563 /* Write out all segments */
564 for (I = 0; I < Count; ++I) {
566 /* Get the segment from the list node */
569 /* Keep the user happy */
571 printf (" Writing `%s'\n", S->Name);
574 /* Write this segment */
576 SegWrite (D->F, S->Seg, O65WriteExpr, D);
579 /* Mark the segment as dumped */
582 /* Calculate the total size */
583 D->SegSize += S->Seg->Size;
586 /* Terminate the relocation table for the this segment */
588 O65RelocPutByte (D->CurReloc, 0);
591 /* Check the size of the segment for overflow */
592 if ((D->Header.Mode & MF_SIZE_32BIT) == 0 && D->SegSize > 0xFFFF) {
593 Error ("Segment overflow in file `%s'", D->Filename);
600 static void O65WriteTextSeg (O65Desc* D, Memory* M)
601 /* Write the code segment to the o65 output file */
603 /* Initialize variables */
604 D->CurReloc = D->TextReloc;
606 /* Dump all text segments */
607 O65WriteSeg (D, D->TextSeg, D->TextCount, 1);
609 /* Set the size of the segment */
610 D->Header.TextSize = D->SegSize;
615 static void O65WriteDataSeg (O65Desc* D, Memory* M)
616 /* Write the data segment to the o65 output file */
618 /* Initialize variables */
619 D->CurReloc = D->DataReloc;
621 /* Dump all data segments */
622 O65WriteSeg (D, D->DataSeg, D->DataCount, 1);
624 /* Set the size of the segment */
625 D->Header.DataSize = D->SegSize;
630 static void O65WriteBssSeg (O65Desc* D, Memory* M)
631 /* "Write" the bss segments to the o65 output file. This will only update
632 * the relevant header fields.
635 /* Initialize variables */
638 /* Dump all data segments */
639 O65WriteSeg (D, D->BssSeg, D->BssCount, 0);
641 /* Set the size of the segment */
642 D->Header.BssSize = D->SegSize;
647 static void O65WriteZPSeg (O65Desc* D, Memory* M)
648 /* "Write" the zeropage segments to the o65 output file. This will only update
649 * the relevant header fields.
652 /* Initialize variables */
655 /* Dump all data segments */
656 O65WriteSeg (D, D->ZPSeg, D->ZPCount, 0);
658 /* Set the size of the segment */
659 D->Header.ZPSize = D->SegSize;
664 static void O65WriteImports (O65Desc* D)
665 /* Write the list of imported symbols to the O65 file */
669 /* Write the number of external symbols */
670 WriteSize (D, ExtSymCount (D->Imports));
672 /* Write out the symbol names, zero terminated */
673 E = ExtSymList (D->Imports);
676 const char* Name = ExtSymName (E);
677 /* And write it to the output file */
678 WriteData (D->F, Name, strlen (Name) + 1);
686 static void O65WriteTextReloc (O65Desc* D)
687 /* Write the relocation for the text segment to the output file */
689 O65WriteReloc (D->TextReloc, D->F);
694 static void O65WriteDataReloc (O65Desc* D)
695 /* Write the relocation for the data segment to the output file */
697 O65WriteReloc (D->DataReloc, D->F);
702 static void O65WriteExports (O65Desc* D)
703 /* Write the list of exports */
711 /*****************************************************************************/
713 /*****************************************************************************/
717 O65Desc* NewO65Desc (void)
718 /* Create, initialize and return a new O65 descriptor struct */
720 /* Allocate a new structure */
721 O65Desc* D = xmalloc (sizeof (O65Desc));
723 /* Initialize the header */
724 D->Header.Version = 0;
726 D->Header.TextBase = 0;
727 D->Header.TextSize = 0;
728 D->Header.DataBase = 0;
729 D->Header.DataSize = 0;
730 D->Header.BssBase = 0;
731 D->Header.BssSize = 0;
732 D->Header.ZPBase = 0;
733 D->Header.ZPSize = 0;
734 D->Header.StackSize = 0; /* Let OS choose a good value */
736 /* Initialize other data */
738 D->Exports = NewExtSymTab ();
739 D->Imports = NewExtSymTab ();
743 D->TextReloc = NewO65RelocTab ();
744 D->DataReloc = NewO65RelocTab ();
754 /* Return the created struct */
760 void FreeO65Desc (O65Desc* D)
761 /* Delete the descriptor struct with cleanup */
763 /* Free the segment arrays */
769 /* Free the relocation tables */
770 FreeO65RelocTab (D->DataReloc);
771 FreeO65RelocTab (D->TextReloc);
773 /* Free the option list */
775 O65Option* O = D->Options;
776 D->Options = D->Options->Next;
780 /* Free the external symbol tables */
781 FreeExtSymTab (D->Exports);
782 FreeExtSymTab (D->Imports);
784 /* Free the struct itself */
790 void O65Set816 (O65Desc* D)
791 /* Enable 816 mode */
793 D->Header.Mode |= MF_CPU_816;
798 void O65SetLargeModel (O65Desc* D)
799 /* Enable a large memory model executable */
801 D->Header.Mode |= MF_SIZE_32BIT;
806 void O65SetAlignment (O65Desc* D, unsigned Align)
807 /* Set the executable alignment */
809 /* Remove all alignment bits from the mode word */
810 D->Header.Mode &= ~0x0003;
812 /* Set the alignment bits */
815 case 2: D->Header.Mode |= 0x01; break;
816 case 4: D->Header.Mode |= 0x02; break;
817 case 256: D->Header.Mode |= 0x03; break;
818 default: Error ("Invalid alignment for O65 format: %u", Align);
824 void O65SetOption (O65Desc* D, unsigned Type, const void* Data, unsigned DataLen)
825 /* Set an o65 header option */
827 /* Create a new option structure */
828 O65Option* O = NewO65Option (Type, Data, DataLen);
830 /* Insert it into the linked list */
831 O->Next = D->Options;
837 void O65SetOS (O65Desc* D, unsigned OS)
838 /* Set an option describing the target operating system */
840 static const unsigned char OSA65 [2] = { O65OS_OSA65, 0 };
841 static const unsigned char Lunix [2] = { O65OS_LUNIX, 0 };
843 /* Write the correct option */
847 O65SetOption (D, O65OPT_OS, OSA65, sizeof (OSA65));
851 O65SetOption (D, O65OPT_OS, Lunix, sizeof (Lunix));
855 Internal ("Trying to set invalid O65 operating system: %u", OS);
862 ExtSym* O65GetImport (O65Desc* D, const char* Ident)
863 /* Return the imported symbol or NULL if not found */
865 /* Retrieve the symbol from the table */
866 return GetExtSym (D->Imports, Ident);
871 void O65SetImport (O65Desc* D, const char* Ident)
872 /* Set an imported identifier */
874 /* Insert the entry into the table */
875 NewExtSym (D->Imports, Ident);
880 ExtSym* O65GetExport (O65Desc* D, const char* Ident)
881 /* Return the exported symbol or NULL if not found */
883 /* Retrieve the symbol from the table */
884 return GetExtSym (D->Exports, Ident);
889 void O65SetExport (O65Desc* D, const char* Ident)
890 /* Set an exported identifier */
892 /* Insert the entry into the table */
893 NewExtSym (D->Exports, Ident);
898 static void O65SetupSegments (O65Desc* D, Memory* M)
899 /* Setup segment assignments */
903 unsigned TextIdx, DataIdx, BssIdx, ZPIdx;
905 /* Initialize the counters */
911 /* Walk through the memory list and count the segment types */
915 /* Get the segment from the list node */
918 /* Check the segment type. */
919 switch (O65SegType (S)) {
920 case O65SEG_TEXT: D->TextCount++; break;
921 case O65SEG_DATA: D->DataCount++; break;
922 case O65SEG_BSS: D->BssCount++; break;
923 case O65SEG_ZP: D->ZPCount++; break;
924 default: Internal ("Invalid return from O65SegType");
927 /* Next segment node */
931 /* Allocate memory according to the numbers */
932 D->TextSeg = xmalloc (D->TextCount * sizeof (SegDesc*));
933 D->DataSeg = xmalloc (D->DataCount * sizeof (SegDesc*));
934 D->BssSeg = xmalloc (D->BssCount * sizeof (SegDesc*));
935 D->ZPSeg = xmalloc (D->ZPCount * sizeof (SegDesc*));
937 /* Walk again through the list and setup the segment arrays */
938 TextIdx = DataIdx = BssIdx = ZPIdx = 0;
942 /* Get the segment from the list node */
945 /* Check the segment type. */
946 switch (O65SegType (S)) {
947 case O65SEG_TEXT: D->TextSeg [TextIdx++] = S; break;
948 case O65SEG_DATA: D->DataSeg [DataIdx++] = S; break;
949 case O65SEG_BSS: D->BssSeg [BssIdx++] = S; break;
950 case O65SEG_ZP: D->ZPSeg [ZPIdx++] = S; break;
951 default: Internal ("Invalid return from O65SegType");
954 /* Next segment node */
961 static int O65Unresolved (const char* Name, void* D)
962 /* Called if an unresolved symbol is encountered */
964 /* Check if the symbol is an imported o65 symbol */
965 if (O65GetImport (D, Name) != 0) {
966 /* This is an external symbol, relax... */
969 /* This is actually an unresolved external. Bump the counter */
970 ((O65Desc*) D)->Undef++;
977 void O65WriteTarget (O65Desc* D, File* F)
978 /* Write an o65 output file */
981 char OptBuf [256]; /* Buffer for option strings */
984 /* Place the filename in the control structure */
985 D->Filename = F->Name;
987 /* The o65 format uses only one memory area per file. Check that. */
990 Warning ("Cannot handle more than one memory area for o65 format");
993 /* Check for unresolved symbols. The function O65Unresolved is called
994 * if we get an unresolved symbol.
996 D->Undef = 0; /* Reset the counter */
997 CheckExports (O65Unresolved, D);
999 /* We had unresolved symbols, cannot create output file */
1000 Error ("%u unresolved external(s) found - cannot create output file", D->Undef);
1003 /* Setup the segment arrays */
1004 O65SetupSegments (D, M);
1007 D->F = fopen (F->Name, "wb");
1009 Error ("Cannot open `%s': %s", F->Name, strerror (errno));
1012 /* Keep the user happy */
1014 printf ("Opened `%s'...\n", F->Name);
1017 /* Define some more options: A timestamp and the linker version */
1019 strcpy (OptBuf, ctime (&T));
1020 O65SetOption (D, O65OPT_TIMESTAMP, OptBuf, strlen (OptBuf) + 1);
1021 sprintf (OptBuf, "ld65 V%u.%u.%u", VER_MAJOR, VER_MINOR, VER_PATCH);
1022 O65SetOption (D, O65OPT_ASM, OptBuf, strlen (OptBuf) + 1);
1024 /* Write the header */
1027 /* Write the text segment */
1028 O65WriteTextSeg (D, M);
1030 /* Write the data segment */
1031 O65WriteDataSeg (D, M);
1033 /* "Write" the bss segments */
1034 O65WriteBssSeg (D, M);
1036 /* "Write" the zeropage segments */
1037 O65WriteZPSeg (D, M);
1039 /* Write the undefined references list */
1040 O65WriteImports (D);
1042 /* Write the text segment relocation table */
1043 O65WriteTextReloc (D);
1045 /* Write the data segment relocation table */
1046 O65WriteDataReloc (D);
1048 /* Write the list of exports */
1049 O65WriteExports (D);
1051 /* Seek back to the start and write the updated header */
1052 fseek (D->F, 0, SEEK_SET);
1055 /* Close the file */
1056 if (fclose (D->F) != 0) {
1057 Error ("Cannot write to `%s': %s", F->Name, strerror (errno));
1060 /* Reset the file and filename */