1/*****************************************************************************/
2/* */
3/* fileio.c */
4/* */
5/* File I/O for the ld65 linker */
6/* */
7/* */
8/* */
9/* (C) 1998-2008 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#include <string.h>
37#include <errno.h>
38
39/* common */
40#include "xmalloc.h"
41
42/* ld65 */
43#include "error.h"
44#include "fileio.h"
45#include "spool.h"
46
47
48
49/*****************************************************************************/
50/* Code */
51/*****************************************************************************/
52
53
54
55void FileSetPos (FILE* F, unsigned long Pos)
56/* Seek to the given absolute position, fail on errors */
57{
58 if (fseek (F, Pos, SEEK_SET) != 0) {
59 Error ("Cannot seek: %s", strerror (errno));
60 }
61}
62
63
64
65unsigned long FileGetPos (FILE* F)
66/* Return the current file position, fail on errors */
67{
68 long Pos = ftell (F);
69 if (Pos < 0) {
70 Error ("Error in ftell: %s", strerror (errno));
71 }
72 return Pos;
73}
74
75
76
77void Write8 (FILE* F, unsigned Val)
78/* Write an 8 bit value to the file */
79{
80 if (putc (Val, F) == EOF) {
81 Error ("Write error (disk full?)");
82 }
83}
84
85
86
87void Write16 (FILE* F, unsigned Val)
88/* Write a 16 bit value to the file */
89{
90 Write8 (F, (unsigned char) Val);
91 Write8 (F, (unsigned char) (Val >> 8));
92}
93
94
95
96void Write24 (FILE* F, unsigned long Val)
97/* Write a 24 bit value to the file */
98{
99 Write8 (F, (unsigned char) Val);
100 Write8 (F, (unsigned char) (Val >> 8));
101 Write8 (F, (unsigned char) (Val >> 16));
102}
103
104
105
106void Write32 (FILE* F, unsigned long Val)
107/* Write a 32 bit value to the file */
108{
109 Write8 (F, (unsigned char) Val);
110 Write8 (F, (unsigned char) (Val >> 8));
111 Write8 (F, (unsigned char) (Val >> 16));
112 Write8 (F, (unsigned char) (Val >> 24));
113}
114
115
116
117void WriteVal (FILE* F, unsigned long Val, unsigned Size)
118/* Write a value of the given size to the output file */
119{
120 switch (Size) {
121
122 case 1:
123 Write8 (F, Val);
124 break;
125
126 case 2:
127 Write16 (F, Val);
128 break;
129
130 case 3:
131 Write24 (F, Val);
132 break;
133
134 case 4:
135 Write32 (F, Val);
136 break;
137
138 default:
139 Internal ("WriteVal: Invalid size: %u", Size);
140
141 }
142}
143
144
145
146void WriteVar (FILE* F, unsigned long V)
147/* Write a variable sized value to the file in special encoding */
148{
149 /* We will write the value to the file in 7 bit chunks. If the 8th bit
150 ** is clear, we're done, if it is set, another chunk follows. This will
151 ** allow us to encode smaller values with less bytes, at the expense of
152 ** needing 5 bytes if a 32 bit value is written to file.
153 */
154 do {
155 unsigned char C = (V & 0x7F);
156 V >>= 7;
157 if (V) {
158 C |= 0x80;
159 }
160 Write8 (F, C);
161 } while (V != 0);
162}
163
164
165
166void WriteStr (FILE* F, const char* S)
167/* Write a string to the file */
168{
169 unsigned Len = strlen (S);
170 WriteVar (F, Len);
171 WriteData (F, S, Len);
172}
173
174
175
176void WriteData (FILE* F, const void* Data, unsigned Size)
177/* Write data to the file */
178{
179 if (fwrite (Data, 1, Size, F) != Size) {
180 Error ("Write error (disk full?)");
181 }
182}
183
184
185
186void WriteMult (FILE* F, unsigned char Val, unsigned long Count)
187/* Write one byte several times to the file */
188{
189 while (Count--) {
190 Write8 (F, Val);
191 }
192}
193
194
195
196unsigned Read8 (FILE* F)
197/* Read an 8 bit value from the file */
198{
199 int C = getc (F);
200 if (C == EOF) {
201 long Pos = ftell (F);
202 Error ("Read error at position %ld (file corrupt?)", Pos);
203 }
204 return C;
205}
206
207
208
209unsigned Read16 (FILE* F)
210/* Read a 16 bit value from the file */
211{
212 unsigned Lo = Read8 (F);
213 unsigned Hi = Read8 (F);
214 return (Hi << 8) | Lo;
215}
216
217
218
219unsigned long Read24 (FILE* F)
220/* Read a 24 bit value from the file */
221{
222 unsigned long Lo = Read16 (F);
223 unsigned long Hi = Read8 (F);
224 return (Hi << 16) | Lo;
225}
226
227
228
229unsigned long Read32 (FILE* F)
230/* Read a 32 bit value from the file */
231{
232 unsigned long Lo = Read16 (F);
233 unsigned long Hi = Read16 (F);
234 return (Hi << 16) | Lo;
235}
236
237
238
239long Read32Signed (FILE* F)
240/* Read a 32 bit value from the file. Sign extend the value. */
241{
242 /* Read a 32 bit value */
243 unsigned long V = Read32 (F);
244
245 /* Sign extend the value */
246 if (V & 0x80000000UL) {
247 /* Signed value */
248 V |= ~0xFFFFFFFFUL;
249 }
250
251 /* Return it as a long */
252 return (long) V;
253}
254
255
256
257unsigned long ReadVar (FILE* F)
258/* Read a variable size value from the file */
259{
260 /* The value was written to the file in 7 bit chunks LSB first. If there
261 ** are more bytes, bit 8 is set, otherwise it is clear.
262 */
263 unsigned char C;
264 unsigned long V = 0;
265 unsigned Shift = 0;
266 do {
267 /* Read one byte */
268 C = Read8 (F);
269 /* Encode it into the target value */
270 V |= ((unsigned long)(C & 0x7F)) << Shift;
271 /* Next value */
272 Shift += 7;
273 } while (C & 0x80);
274
275 /* Return the value read */
276 return V;
277}
278
279
280
281unsigned ReadStr (FILE* F)
282/* Read a string from the file, place it into the global string pool, and
283** return its string id.
284*/
285{
286 unsigned Id;
287 StrBuf Buf = STATIC_STRBUF_INITIALIZER;
288
289 /* Read the length */
290 unsigned Len = ReadVar (F);
291
292 /* Expand the string buffer memory */
293 SB_Realloc (&Buf, Len);
294
295 /* Read the string */
296 ReadData (F, SB_GetBuf (&Buf), Len);
297 Buf.Len = Len;
298
299 /* Insert it into the string pool and remember the id */
300 Id = GetStrBufId (&Buf);
301
302 /* Free the memory buffer */
303 SB_Done (&Buf);
304
305 /* Return the string id */
306 return Id;
307}
308
309
310
311FilePos* ReadFilePos (FILE* F, FilePos* Pos)
312/* Read a file position from the file */
313{
314 /* Read the data fields */
315 Pos->Line = ReadVar (F);
316 Pos->Col = ReadVar (F);
317 Pos->Name = ReadVar (F);
318 return Pos;
319}
320
321
322
323void* ReadData (FILE* F, void* Data, unsigned Size)
324/* Read data from the file */
325{
326 /* Explicitly allow reading zero bytes */
327 if (Size > 0) {
328 if (fread (Data, 1, Size, F) != Size) {
329 long Pos = ftell (F);
330 Error ("Read error at position %ld (file corrupt?)", Pos);
331 }
332 }
333 return Data;
334}
335