1 /*
2 * Bytecode utility functions
3 *
4 * Copyright (C) 2001-2007 Peter Johnson
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND OTHER CONTRIBUTORS ``AS IS''
16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR OTHER CONTRIBUTORS BE
19 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
20 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
21 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
22 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
23 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
24 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
25 * POSSIBILITY OF SUCH DAMAGE.
26 */
27 #include "util.h"
28
29 #include "libyasm-stdint.h"
30 #include "coretype.h"
31
32 #include "errwarn.h"
33 #include "intnum.h"
34 #include "expr.h"
35 #include "value.h"
36 #include "symrec.h"
37
38 #include "bytecode.h"
39
40
41 void
yasm_bc_set_multiple(yasm_bytecode * bc,yasm_expr * e)42 yasm_bc_set_multiple(yasm_bytecode *bc, yasm_expr *e)
43 {
44 if (bc->multiple)
45 bc->multiple = yasm_expr_create_tree(bc->multiple, YASM_EXPR_MUL, e,
46 e->line);
47 else
48 bc->multiple = e;
49 }
50
51 void
yasm_bc_finalize_common(yasm_bytecode * bc,yasm_bytecode * prev_bc)52 yasm_bc_finalize_common(yasm_bytecode *bc, yasm_bytecode *prev_bc)
53 {
54 }
55
56 int
yasm_bc_calc_len_common(yasm_bytecode * bc,yasm_bc_add_span_func add_span,void * add_span_data)57 yasm_bc_calc_len_common(yasm_bytecode *bc, yasm_bc_add_span_func add_span,
58 void *add_span_data)
59 {
60 yasm_internal_error(N_("bytecode length cannot be calculated"));
61 /*@unreached@*/
62 return 0;
63 }
64
65 int
yasm_bc_expand_common(yasm_bytecode * bc,int span,long old_val,long new_val,long * neg_thres,long * pos_thres)66 yasm_bc_expand_common(yasm_bytecode *bc, int span, long old_val, long new_val,
67 /*@out@*/ long *neg_thres, /*@out@*/ long *pos_thres)
68 {
69 yasm_internal_error(N_("bytecode does not have any dependent spans"));
70 /*@unreached@*/
71 return 0;
72 }
73
74 int
yasm_bc_tobytes_common(yasm_bytecode * bc,unsigned char ** buf,unsigned char * bufstart,void * d,yasm_output_value_func output_value,yasm_output_reloc_func output_reloc)75 yasm_bc_tobytes_common(yasm_bytecode *bc, unsigned char **buf,
76 unsigned char *bufstart, void *d,
77 yasm_output_value_func output_value,
78 /*@null@*/ yasm_output_reloc_func output_reloc)
79 {
80 yasm_internal_error(N_("bytecode cannot be converted to bytes"));
81 /*@unreached@*/
82 return 0;
83 }
84
85 void
yasm_bc_transform(yasm_bytecode * bc,const yasm_bytecode_callback * callback,void * contents)86 yasm_bc_transform(yasm_bytecode *bc, const yasm_bytecode_callback *callback,
87 void *contents)
88 {
89 if (bc->callback)
90 bc->callback->destroy(bc->contents);
91 bc->callback = callback;
92 bc->contents = contents;
93 }
94
95 yasm_bytecode *
yasm_bc_create_common(const yasm_bytecode_callback * callback,void * contents,unsigned long line)96 yasm_bc_create_common(const yasm_bytecode_callback *callback, void *contents,
97 unsigned long line)
98 {
99 yasm_bytecode *bc = yasm_xmalloc(sizeof(yasm_bytecode));
100
101 bc->callback = callback;
102 bc->section = NULL;
103 bc->multiple = (yasm_expr *)NULL;
104 bc->len = 0;
105 bc->mult_int = 1;
106 bc->line = line;
107 bc->offset = ~0UL; /* obviously incorrect / uninitialized value */
108 bc->symrecs = NULL;
109 bc->contents = contents;
110
111 return bc;
112 }
113
114 yasm_section *
yasm_bc_get_section(yasm_bytecode * bc)115 yasm_bc_get_section(yasm_bytecode *bc)
116 {
117 return bc->section;
118 }
119
120 void
yasm_bc__add_symrec(yasm_bytecode * bc,yasm_symrec * sym)121 yasm_bc__add_symrec(yasm_bytecode *bc, yasm_symrec *sym)
122 {
123 if (!bc->symrecs) {
124 bc->symrecs = yasm_xmalloc(2*sizeof(yasm_symrec *));
125 bc->symrecs[0] = sym;
126 bc->symrecs[1] = NULL;
127 } else {
128 /* Very inefficient implementation for large numbers of symbols. But
129 * that would be very unusual, so use the simple algorithm instead.
130 */
131 size_t count = 1;
132 while (bc->symrecs[count])
133 count++;
134 bc->symrecs = yasm_xrealloc(bc->symrecs,
135 (count+2)*sizeof(yasm_symrec *));
136 bc->symrecs[count] = sym;
137 bc->symrecs[count+1] = NULL;
138 }
139 }
140
141 void
yasm_bc_destroy(yasm_bytecode * bc)142 yasm_bc_destroy(yasm_bytecode *bc)
143 {
144 if (!bc)
145 return;
146
147 if (bc->callback)
148 bc->callback->destroy(bc->contents);
149 yasm_expr_destroy(bc->multiple);
150 if (bc->symrecs)
151 yasm_xfree(bc->symrecs);
152 yasm_xfree(bc);
153 }
154
155 void
yasm_bc_print(const yasm_bytecode * bc,FILE * f,int indent_level)156 yasm_bc_print(const yasm_bytecode *bc, FILE *f, int indent_level)
157 {
158 if (!bc->callback)
159 fprintf(f, "%*s_Empty_\n", indent_level, "");
160 else
161 bc->callback->print(bc->contents, f, indent_level);
162 fprintf(f, "%*sMultiple=", indent_level, "");
163 if (!bc->multiple)
164 fprintf(f, "nil (1)");
165 else
166 yasm_expr_print(bc->multiple, f);
167 fprintf(f, "\n%*sLength=%lu\n", indent_level, "", bc->len);
168 fprintf(f, "%*sLine Index=%lu\n", indent_level, "", bc->line);
169 fprintf(f, "%*sOffset=%lx\n", indent_level, "", bc->offset);
170 }
171
172 void
yasm_bc_finalize(yasm_bytecode * bc,yasm_bytecode * prev_bc)173 yasm_bc_finalize(yasm_bytecode *bc, yasm_bytecode *prev_bc)
174 {
175 if (bc->callback)
176 bc->callback->finalize(bc, prev_bc);
177 if (bc->multiple) {
178 yasm_value val;
179
180 if (yasm_value_finalize_expr(&val, bc->multiple, prev_bc, 0))
181 yasm_error_set(YASM_ERROR_TOO_COMPLEX,
182 N_("multiple expression too complex"));
183 else if (val.rel)
184 yasm_error_set(YASM_ERROR_NOT_ABSOLUTE,
185 N_("multiple expression not absolute"));
186 /* Finalize creates NULL output if value=0, but bc->multiple is NULL
187 * if value=1 (this difference is to make the common case small).
188 * However, this means we need to set bc->multiple explicitly to 0
189 * here if val.abs is NULL.
190 */
191 if (val.abs)
192 bc->multiple = val.abs;
193 else
194 bc->multiple = yasm_expr_create_ident(
195 yasm_expr_int(yasm_intnum_create_uint(0)), bc->line);
196 }
197 }
198
199 /*@null@*/ yasm_intnum *
yasm_calc_bc_dist(yasm_bytecode * precbc1,yasm_bytecode * precbc2)200 yasm_calc_bc_dist(yasm_bytecode *precbc1, yasm_bytecode *precbc2)
201 {
202 unsigned long dist2, dist1;
203 yasm_intnum *intn;
204
205 if (precbc1->section != precbc2->section)
206 return NULL;
207
208 dist1 = yasm_bc_next_offset(precbc1);
209 dist2 = yasm_bc_next_offset(precbc2);
210 if (dist2 < dist1) {
211 intn = yasm_intnum_create_uint(dist1 - dist2);
212 yasm_intnum_calc(intn, YASM_EXPR_NEG, NULL);
213 return intn;
214 }
215 dist2 -= dist1;
216 return yasm_intnum_create_uint(dist2);
217 }
218
219 unsigned long
yasm_bc_next_offset(yasm_bytecode * precbc)220 yasm_bc_next_offset(yasm_bytecode *precbc)
221 {
222 return precbc->offset + precbc->len*precbc->mult_int;
223 }
224
225 int
yasm_bc_elem_size(yasm_bytecode * bc)226 yasm_bc_elem_size(yasm_bytecode *bc)
227 {
228 if (!bc->callback) {
229 yasm_internal_error(N_("got empty bytecode in yasm_bc_elem_size"));
230 return 0;
231 } else if (!bc->callback->elem_size)
232 return 0;
233 else
234 return bc->callback->elem_size(bc);
235 }
236
237 int
yasm_bc_calc_len(yasm_bytecode * bc,yasm_bc_add_span_func add_span,void * add_span_data)238 yasm_bc_calc_len(yasm_bytecode *bc, yasm_bc_add_span_func add_span,
239 void *add_span_data)
240 {
241 int retval = 0;
242
243 bc->len = 0;
244
245 if (!bc->callback)
246 yasm_internal_error(N_("got empty bytecode in yasm_bc_calc_len"));
247 else
248 retval = bc->callback->calc_len(bc, add_span, add_span_data);
249
250 /* Check for multiples */
251 bc->mult_int = 1;
252 if (bc->multiple) {
253 /*@dependent@*/ /*@null@*/ const yasm_intnum *num;
254
255 num = yasm_expr_get_intnum(&bc->multiple, 0);
256 if (num) {
257 if (yasm_intnum_sign(num) < 0) {
258 yasm_error_set(YASM_ERROR_VALUE, N_("multiple is negative"));
259 retval = -1;
260 } else
261 bc->mult_int = yasm_intnum_get_int(num);
262 } else {
263 if (yasm_expr__contains(bc->multiple, YASM_EXPR_FLOAT)) {
264 yasm_error_set(YASM_ERROR_VALUE,
265 N_("expression must not contain floating point value"));
266 retval = -1;
267 } else {
268 yasm_value value;
269 yasm_value_initialize(&value, bc->multiple, 0);
270 add_span(add_span_data, bc, 0, &value, 0, 0);
271 bc->mult_int = 0; /* assume 0 to start */
272 }
273 }
274 }
275
276 /* If we got an error somewhere along the line, clear out any calc len */
277 if (retval < 0)
278 bc->len = 0;
279
280 return retval;
281 }
282
283 int
yasm_bc_expand(yasm_bytecode * bc,int span,long old_val,long new_val,long * neg_thres,long * pos_thres)284 yasm_bc_expand(yasm_bytecode *bc, int span, long old_val, long new_val,
285 /*@out@*/ long *neg_thres, /*@out@*/ long *pos_thres)
286 {
287 if (span == 0) {
288 bc->mult_int = new_val;
289 return 1;
290 }
291 if (!bc->callback) {
292 yasm_internal_error(N_("got empty bytecode in yasm_bc_expand"));
293 /*@unreached@*/
294 return -1;
295 } else
296 return bc->callback->expand(bc, span, old_val, new_val, neg_thres,
297 pos_thres);
298 }
299
300 /*@null@*/ /*@only@*/ unsigned char *
yasm_bc_tobytes(yasm_bytecode * bc,unsigned char * buf,unsigned long * bufsize,int * gap,void * d,yasm_output_value_func output_value,yasm_output_reloc_func output_reloc)301 yasm_bc_tobytes(yasm_bytecode *bc, unsigned char *buf, unsigned long *bufsize,
302 /*@out@*/ int *gap, void *d,
303 yasm_output_value_func output_value,
304 /*@null@*/ yasm_output_reloc_func output_reloc)
305 /*@sets *buf@*/
306 {
307 /*@only@*/ /*@null@*/ unsigned char *mybuf = NULL;
308 unsigned char *bufstart;
309 unsigned char *origbuf, *destbuf;
310 long i;
311 int error = 0;
312
313 long mult;
314 if (yasm_bc_get_multiple(bc, &mult, 1) || mult == 0) {
315 *bufsize = 0;
316 return NULL;
317 }
318 bc->mult_int = mult;
319
320 /* special case for reserve bytecodes */
321 if (bc->callback->special == YASM_BC_SPECIAL_RESERVE) {
322 *bufsize = bc->len*bc->mult_int;
323 *gap = 1;
324 return NULL; /* we didn't allocate a buffer */
325 }
326 *gap = 0;
327
328 if (*bufsize < bc->len*bc->mult_int) {
329 mybuf = yasm_xmalloc(bc->len*bc->mult_int);
330 destbuf = mybuf;
331 } else
332 destbuf = buf;
333 bufstart = destbuf;
334
335 *bufsize = bc->len*bc->mult_int;
336
337 if (!bc->callback)
338 yasm_internal_error(N_("got empty bytecode in bc_tobytes"));
339 else for (i=0; i<bc->mult_int; i++) {
340 origbuf = destbuf;
341 error = bc->callback->tobytes(bc, &destbuf, bufstart, d, output_value,
342 output_reloc);
343
344 if (!error && ((unsigned long)(destbuf - origbuf) != bc->len))
345 yasm_internal_error(
346 N_("written length does not match optimized length"));
347 }
348
349 return mybuf;
350 }
351
352 int
yasm_bc_get_multiple(yasm_bytecode * bc,long * multiple,int calc_bc_dist)353 yasm_bc_get_multiple(yasm_bytecode *bc, long *multiple, int calc_bc_dist)
354 {
355 /*@dependent@*/ /*@null@*/ const yasm_intnum *num;
356
357 *multiple = 1;
358 if (bc->multiple) {
359 num = yasm_expr_get_intnum(&bc->multiple, calc_bc_dist);
360 if (!num) {
361 yasm_error_set(YASM_ERROR_VALUE,
362 N_("could not determine multiple"));
363 return 1;
364 }
365 if (yasm_intnum_sign(num) < 0) {
366 yasm_error_set(YASM_ERROR_VALUE, N_("multiple is negative"));
367 return 1;
368 }
369 *multiple = yasm_intnum_get_int(num);
370 }
371 return 0;
372 }
373
374 const yasm_expr *
yasm_bc_get_multiple_expr(const yasm_bytecode * bc)375 yasm_bc_get_multiple_expr(const yasm_bytecode *bc)
376 {
377 return bc->multiple;
378 }
379
380 yasm_insn *
yasm_bc_get_insn(yasm_bytecode * bc)381 yasm_bc_get_insn(yasm_bytecode *bc)
382 {
383 if (bc->callback->special != YASM_BC_SPECIAL_INSN)
384 return NULL;
385 return (yasm_insn *)bc->contents;
386 }
387