1 /*
2 ** DynASM x86 encoding engine.
3 ** Copyright (C) 2005-2021 Mike Pall. All rights reserved.
4 ** Released under the MIT license. See dynasm.lua for full copyright notice.
5 */
6
7 #include <stddef.h>
8 #include <stdarg.h>
9 #include <string.h>
10 #include <stdlib.h>
11
12 #define DASM_ARCH "x86"
13
14 #ifndef DASM_EXTERN
15 #define DASM_EXTERN(a,b,c,d) 0
16 #endif
17
18 /* Action definitions. DASM_STOP must be 255. */
19 enum {
20 DASM_DISP = 233,
21 DASM_IMM_S, DASM_IMM_B, DASM_IMM_W, DASM_IMM_D, DASM_IMM_WB, DASM_IMM_DB,
22 DASM_VREG, DASM_SPACE, DASM_SETLABEL, DASM_REL_A, DASM_REL_LG, DASM_REL_PC,
23 DASM_IMM_LG, DASM_IMM_PC, DASM_LABEL_LG, DASM_LABEL_PC, DASM_ALIGN,
24 DASM_EXTERN, DASM_ESC, DASM_MARK, DASM_SECTION, DASM_STOP
25 };
26
27 /* Maximum number of section buffer positions for a single dasm_put() call. */
28 #define DASM_MAXSECPOS 25
29
30 /* DynASM encoder status codes. Action list offset or number are or'ed in. */
31 #define DASM_S_OK 0x00000000
32 #define DASM_S_NOMEM 0x01000000
33 #define DASM_S_PHASE 0x02000000
34 #define DASM_S_MATCH_SEC 0x03000000
35 #define DASM_S_RANGE_I 0x11000000
36 #define DASM_S_RANGE_SEC 0x12000000
37 #define DASM_S_RANGE_LG 0x13000000
38 #define DASM_S_RANGE_PC 0x14000000
39 #define DASM_S_RANGE_VREG 0x15000000
40 #define DASM_S_UNDEF_L 0x21000000
41 #define DASM_S_UNDEF_PC 0x22000000
42
43 /* Macros to convert positions (8 bit section + 24 bit index). */
44 #define DASM_POS2IDX(pos) ((pos)&0x00ffffff)
45 #define DASM_POS2BIAS(pos) ((pos)&0xff000000)
46 #define DASM_SEC2POS(sec) ((sec)<<24)
47 #define DASM_POS2SEC(pos) ((pos)>>24)
48 #define DASM_POS2PTR(D, pos) (D->sections[DASM_POS2SEC(pos)].rbuf + (pos))
49
50 /* Action list type. */
51 typedef const unsigned char *dasm_ActList;
52
53 /* Per-section structure. */
54 typedef struct dasm_Section {
55 int *rbuf; /* Biased buffer pointer (negative section bias). */
56 int *buf; /* True buffer pointer. */
57 size_t bsize; /* Buffer size in bytes. */
58 int pos; /* Biased buffer position. */
59 int epos; /* End of biased buffer position - max single put. */
60 int ofs; /* Byte offset into section. */
61 } dasm_Section;
62
63 /* Core structure holding the DynASM encoding state. */
64 struct dasm_State {
65 size_t psize; /* Allocated size of this structure. */
66 dasm_ActList actionlist; /* Current actionlist pointer. */
67 int *lglabels; /* Local/global chain/pos ptrs. */
68 size_t lgsize;
69 int *pclabels; /* PC label chains/pos ptrs. */
70 size_t pcsize;
71 void **globals; /* Array of globals (bias -10). */
72 dasm_Section *section; /* Pointer to active section. */
73 size_t codesize; /* Total size of all code sections. */
74 int maxsection; /* 0 <= sectionidx < maxsection. */
75 int status; /* Status code. */
76 dasm_Section sections[1]; /* All sections. Alloc-extended. */
77 };
78
79 /* The size of the core structure depends on the max. number of sections. */
80 #define DASM_PSZ(ms) (sizeof(dasm_State)+(ms-1)*sizeof(dasm_Section))
81
82 /* Perform potentially overflowing pointer operations in a way that avoids UB. */
83 #define DASM_PTR_SUB(p1, off) ((void *) ((uintptr_t) (p1) - sizeof(*p1) * (uintptr_t) (off)))
84 #define DASM_PTR_ADD(p1, off) ((void *) ((uintptr_t) (p1) + sizeof(*p1) * (uintptr_t) (off)))
85
86 /* Initialize DynASM state. */
dasm_init(Dst_DECL,int maxsection)87 void dasm_init(Dst_DECL, int maxsection)
88 {
89 dasm_State *D;
90 size_t psz = 0;
91 int i;
92 Dst_REF = NULL;
93 DASM_M_GROW(Dst, struct dasm_State, Dst_REF, psz, DASM_PSZ(maxsection));
94 D = Dst_REF;
95 D->psize = psz;
96 D->lglabels = NULL;
97 D->lgsize = 0;
98 D->pclabels = NULL;
99 D->pcsize = 0;
100 D->globals = NULL;
101 D->maxsection = maxsection;
102 for (i = 0; i < maxsection; i++) {
103 D->sections[i].buf = NULL; /* Need this for pass3. */
104 D->sections[i].rbuf = DASM_PTR_SUB(D->sections[i].buf, DASM_SEC2POS(i));
105 D->sections[i].bsize = 0;
106 D->sections[i].epos = 0; /* Wrong, but is recalculated after resize. */
107 }
108 }
109
110 /* Free DynASM state. */
dasm_free(Dst_DECL)111 void dasm_free(Dst_DECL)
112 {
113 dasm_State *D = Dst_REF;
114 int i;
115 for (i = 0; i < D->maxsection; i++)
116 if (D->sections[i].buf)
117 DASM_M_FREE(Dst, D->sections[i].buf, D->sections[i].bsize);
118 if (D->pclabels) DASM_M_FREE(Dst, D->pclabels, D->pcsize);
119 if (D->lglabels) DASM_M_FREE(Dst, D->lglabels, D->lgsize);
120 DASM_M_FREE(Dst, D, D->psize);
121 }
122
123 /* Setup global label array. Must be called before dasm_setup(). */
dasm_setupglobal(Dst_DECL,void ** gl,unsigned int maxgl)124 void dasm_setupglobal(Dst_DECL, void **gl, unsigned int maxgl)
125 {
126 dasm_State *D = Dst_REF;
127 #ifdef __GNUC__
128 # pragma GCC diagnostic push
129 # pragma GCC diagnostic ignored "-Warray-bounds"
130 #endif
131 D->globals = gl - 10; /* Negative bias to compensate for locals. */
132 #ifdef __GNUC__
133 # pragma GCC diagnostic pop
134 #endif
135 DASM_M_GROW(Dst, int, D->lglabels, D->lgsize, (10+maxgl)*sizeof(int));
136 }
137
138 /* Grow PC label array. Can be called after dasm_setup(), too. */
dasm_growpc(Dst_DECL,unsigned int maxpc)139 void dasm_growpc(Dst_DECL, unsigned int maxpc)
140 {
141 dasm_State *D = Dst_REF;
142 size_t osz = D->pcsize;
143 DASM_M_GROW(Dst, int, D->pclabels, D->pcsize, maxpc*sizeof(int));
144 memset((void *)(((unsigned char *)D->pclabels)+osz), 0, D->pcsize-osz);
145 }
146
147 /* Setup encoder. */
dasm_setup(Dst_DECL,const void * actionlist)148 void dasm_setup(Dst_DECL, const void *actionlist)
149 {
150 dasm_State *D = Dst_REF;
151 int i;
152 D->actionlist = (dasm_ActList)actionlist;
153 D->status = DASM_S_OK;
154 D->section = &D->sections[0];
155 memset((void *)D->lglabels, 0, D->lgsize);
156 if (D->pclabels) memset((void *)D->pclabels, 0, D->pcsize);
157 for (i = 0; i < D->maxsection; i++) {
158 D->sections[i].pos = DASM_SEC2POS(i);
159 D->sections[i].ofs = 0;
160 }
161 }
162
163
164 #ifdef DASM_CHECKS
165 #define CK(x, st) \
166 do { if (!(x)) { \
167 D->status = DASM_S_##st|(int)(p-D->actionlist-1); return; } } while (0)
168 #define CKPL(kind, st) \
169 do { if ((size_t)((char *)pl-(char *)D->kind##labels) >= D->kind##size) { \
170 D->status=DASM_S_RANGE_##st|(int)(p-D->actionlist-1); return; } } while (0)
171 #else
172 #define CK(x, st) ((void)0)
173 #define CKPL(kind, st) ((void)0)
174 #endif
175
176 /* Pass 1: Store actions and args, link branches/labels, estimate offsets. */
dasm_put(Dst_DECL,int start,...)177 void dasm_put(Dst_DECL, int start, ...)
178 {
179 va_list ap;
180 dasm_State *D = Dst_REF;
181 dasm_ActList p = D->actionlist + start;
182 dasm_Section *sec = D->section;
183 int pos = sec->pos, ofs = sec->ofs, mrm = -1;
184 int *b;
185
186 if (pos >= sec->epos) {
187 DASM_M_GROW(Dst, int, sec->buf, sec->bsize,
188 sec->bsize + 2*DASM_MAXSECPOS*sizeof(int));
189 sec->rbuf = sec->buf - DASM_POS2BIAS(pos);
190 sec->epos = (int)sec->bsize/sizeof(int) - DASM_MAXSECPOS+DASM_POS2BIAS(pos);
191 }
192
193 b = sec->rbuf;
194 b[pos++] = start;
195
196 va_start(ap, start);
197 while (1) {
198 int action = *p++;
199 if (action < DASM_DISP) {
200 ofs++;
201 } else if (action <= DASM_REL_A) {
202 int n = va_arg(ap, int);
203 b[pos++] = n;
204 switch (action) {
205 case DASM_DISP:
206 if (n == 0) { if (mrm < 0) mrm = p[-2]; if ((mrm&7) != 5) break; }
207 /* fallthrough */
208 case DASM_IMM_DB: if ((((unsigned)n+128)&-256) == 0) goto ob; /* fallthrough */
209 case DASM_REL_A: /* Assumes ptrdiff_t is int. !x64 */
210 case DASM_IMM_D: ofs += 4; break;
211 case DASM_IMM_S: CK(((n+128)&-256) == 0, RANGE_I); goto ob;
212 case DASM_IMM_B: CK((n&-256) == 0, RANGE_I); ob: ofs++; break;
213 case DASM_IMM_WB: if (((n+128)&-256) == 0) goto ob; /* fallthrough */
214 case DASM_IMM_W: CK((n&-65536) == 0, RANGE_I); ofs += 2; break;
215 case DASM_SPACE: p++; ofs += n; break;
216 case DASM_SETLABEL: b[pos-2] = -0x40000000; break; /* Neg. label ofs. */
217 case DASM_VREG: CK((n&-16) == 0 && (n != 4 || (*p>>5) != 2), RANGE_VREG);
218 if (*p < 0x40 && p[1] == DASM_DISP) mrm = n;
219 if (*p < 0x20 && (n&7) == 4) ofs++;
220 switch ((*p++ >> 3) & 3) {
221 case 3: n |= b[pos-3]; /* fallthrough */
222 case 2: n |= b[pos-2]; /* fallthrough */
223 case 1: if (n <= 7) { b[pos-1] |= 0x10; ofs--; }
224 }
225 continue;
226 }
227 mrm = -1;
228 } else {
229 int *pl, n;
230 switch (action) {
231 case DASM_REL_LG:
232 case DASM_IMM_LG:
233 n = *p++; pl = D->lglabels + n;
234 /* Bkwd rel or global. */
235 if (n <= 246) { CK(n>=10||*pl<0, RANGE_LG); CKPL(lg, LG); goto putrel; }
236 pl -= 246; n = *pl;
237 if (n < 0) n = 0; /* Start new chain for fwd rel if label exists. */
238 goto linkrel;
239 case DASM_REL_PC:
240 case DASM_IMM_PC: pl = D->pclabels + va_arg(ap, int); CKPL(pc, PC);
241 putrel:
242 n = *pl;
243 if (n < 0) { /* Label exists. Get label pos and store it. */
244 b[pos] = -n;
245 } else {
246 linkrel:
247 b[pos] = n; /* Else link to rel chain, anchored at label. */
248 *pl = pos;
249 }
250 pos++;
251 ofs += 4; /* Maximum offset needed. */
252 if (action == DASM_REL_LG || action == DASM_REL_PC) {
253 b[pos++] = ofs; /* Store pass1 offset estimate. */
254 } else if (sizeof(ptrdiff_t) == 8) {
255 ofs += 4;
256 }
257 break;
258 case DASM_LABEL_LG: pl = D->lglabels + *p++; CKPL(lg, LG); goto putlabel;
259 case DASM_LABEL_PC: pl = D->pclabels + va_arg(ap, int); CKPL(pc, PC);
260 putlabel:
261 n = *pl; /* n > 0: Collapse rel chain and replace with label pos. */
262 while (n > 0) { int *pb = DASM_POS2PTR(D, n); n = *pb; *pb = pos; }
263 *pl = -pos; /* Label exists now. */
264 b[pos++] = ofs; /* Store pass1 offset estimate. */
265 break;
266 case DASM_ALIGN:
267 ofs += *p++; /* Maximum alignment needed (arg is 2**n-1). */
268 b[pos++] = ofs; /* Store pass1 offset estimate. */
269 break;
270 case DASM_EXTERN: p += 2; ofs += 4; break;
271 case DASM_ESC: p++; ofs++; break;
272 case DASM_MARK: mrm = p[-2]; break;
273 case DASM_SECTION:
274 n = *p; CK(n < D->maxsection, RANGE_SEC); D->section = &D->sections[n];
275 case DASM_STOP: goto stop;
276 }
277 }
278 }
279 stop:
280 va_end(ap);
281 sec->pos = pos;
282 sec->ofs = ofs;
283 }
284 #undef CK
285
286 /* Pass 2: Link sections, shrink branches/aligns, fix label offsets. */
dasm_link(Dst_DECL,size_t * szp)287 int dasm_link(Dst_DECL, size_t *szp)
288 {
289 dasm_State *D = Dst_REF;
290 int secnum;
291 int ofs = 0;
292
293 #ifdef DASM_CHECKS
294 *szp = 0;
295 if (D->status != DASM_S_OK) return D->status;
296 {
297 int pc;
298 for (pc = 0; pc*sizeof(int) < D->pcsize; pc++)
299 if (D->pclabels[pc] > 0) return DASM_S_UNDEF_PC|pc;
300 }
301 #endif
302
303 { /* Handle globals not defined in this translation unit. */
304 int idx;
305 for (idx = 10; idx*sizeof(int) < D->lgsize; idx++) {
306 int n = D->lglabels[idx];
307 /* Undefined label: Collapse rel chain and replace with marker (< 0). */
308 while (n > 0) { int *pb = DASM_POS2PTR(D, n); n = *pb; *pb = -idx; }
309 }
310 }
311
312 /* Combine all code sections. No support for data sections (yet). */
313 for (secnum = 0; secnum < D->maxsection; secnum++) {
314 dasm_Section *sec = D->sections + secnum;
315 int *b = sec->rbuf;
316 int pos = DASM_SEC2POS(secnum);
317 int lastpos = sec->pos;
318
319 while (pos != lastpos) {
320 dasm_ActList p = D->actionlist + b[pos++];
321 int op = 0;
322 while (1) {
323 int action = *p++;
324 switch (action) {
325 case DASM_REL_LG: p++;
326 /* fallthrough */
327 case DASM_REL_PC: {
328 int shrink = op == 0xe9 ? 3 : ((op&0xf0) == 0x80 ? 4 : 0);
329 if (shrink) { /* Shrinkable branch opcode? */
330 int lofs, lpos = b[pos];
331 if (lpos < 0) goto noshrink; /* Ext global? */
332 lofs = *DASM_POS2PTR(D, lpos);
333 if (lpos > pos) { /* Fwd label: add cumulative section offsets. */
334 int i;
335 for (i = secnum; i < DASM_POS2SEC(lpos); i++)
336 lofs += D->sections[i].ofs;
337 } else {
338 lofs -= ofs; /* Bkwd label: unfix offset. */
339 }
340 lofs -= b[pos+1]; /* Short branch ok? */
341 if (lofs >= -128-shrink && lofs <= 127) ofs -= shrink; /* Yes. */
342 else { noshrink: shrink = 0; } /* No, cannot shrink op. */
343 }
344 b[pos+1] = shrink;
345 pos += 2;
346 break;
347 }
348 /* fallthrough */
349 case DASM_SPACE: case DASM_IMM_LG: case DASM_VREG: p++;
350 case DASM_DISP: case DASM_IMM_S: case DASM_IMM_B: case DASM_IMM_W:
351 case DASM_IMM_D: case DASM_IMM_WB: case DASM_IMM_DB:
352 case DASM_SETLABEL: case DASM_REL_A: case DASM_IMM_PC: pos++; break;
353 case DASM_LABEL_LG: p++;
354 /* fallthrough */
355 case DASM_LABEL_PC: b[pos++] += ofs; break; /* Fix label offset. */
356 case DASM_ALIGN: ofs -= (b[pos++]+ofs)&*p++; break; /* Adjust ofs. */
357 case DASM_EXTERN: p += 2; break;
358 case DASM_ESC: op = *p++; break;
359 case DASM_MARK: break;
360 case DASM_SECTION: case DASM_STOP: goto stop;
361 default: op = action; break;
362 }
363 }
364 stop: (void)0;
365 }
366 ofs += sec->ofs; /* Next section starts right after current section. */
367 }
368
369 D->codesize = ofs; /* Total size of all code sections */
370 *szp = ofs;
371 return DASM_S_OK;
372 }
373
374 #define dasmb(x) *cp++ = (unsigned char)(x)
375 #ifndef DASM_ALIGNED_WRITES
376 typedef ZEND_SET_ALIGNED(1, unsigned short unaligned_short);
377 typedef ZEND_SET_ALIGNED(1, unsigned int unaligned_int);
378 typedef ZEND_SET_ALIGNED(1, unsigned long long unaligned_long_long);
379 #define dasmw(x) \
380 do { *((unaligned_short *)cp) = (unsigned short)(x); cp+=2; } while (0)
381 #define dasmd(x) \
382 do { *((unaligned_int *)cp) = (unsigned int)(x); cp+=4; } while (0)
383 #define dasmq(x) \
384 do { *((unaligned_long_long *)cp) = (unsigned long long)(x); cp+=8; } while (0)
385 #else
386 #define dasmw(x) do { dasmb(x); dasmb((x)>>8); } while (0)
387 #define dasmd(x) do { dasmw(x); dasmw((x)>>16); } while (0)
388 #define dasmq(x) do { dasmd(x); dasmd((x)>>32); } while (0)
389 #endif
dasma_(unsigned char * cp,ptrdiff_t x)390 static unsigned char *dasma_(unsigned char *cp, ptrdiff_t x)
391 {
392 if (sizeof(ptrdiff_t) == 8)
393 dasmq((unsigned long long)x);
394 else
395 dasmd((unsigned int)x);
396 return cp;
397 }
398 #define dasma(x) (cp = dasma_(cp, (x)))
399
400 /* Pass 3: Encode sections. */
dasm_encode(Dst_DECL,void * buffer)401 int dasm_encode(Dst_DECL, void *buffer)
402 {
403 dasm_State *D = Dst_REF;
404 unsigned char *base = (unsigned char *)buffer;
405 unsigned char *cp = base;
406 int secnum;
407
408 /* Encode all code sections. No support for data sections (yet). */
409 for (secnum = 0; secnum < D->maxsection; secnum++) {
410 dasm_Section *sec = D->sections + secnum;
411 int *b = sec->buf;
412 int *endb = DASM_PTR_ADD(sec->rbuf, sec->pos);
413
414 while (b != endb) {
415 dasm_ActList p = D->actionlist + *b++;
416 unsigned char *mark = NULL;
417 while (1) {
418 int action = *p++;
419 int n = (action >= DASM_DISP && action <= DASM_ALIGN) ? *b++ : 0;
420 switch (action) {
421 case DASM_DISP: if (!mark) mark = cp; {
422 unsigned char *mm = mark;
423 if (*p != DASM_IMM_DB && *p != DASM_IMM_WB) mark = NULL;
424 if (n == 0) { int mrm = mm[-1]&7; if (mrm == 4) mrm = mm[0]&7;
425 if (mrm != 5) { mm[-1] -= 0x80; break; } }
426 if ((((unsigned)n+128) & -256) != 0) goto wd; else mm[-1] -= 0x40;
427 }
428 /* fallthrough */
429 case DASM_IMM_S: case DASM_IMM_B: wb: dasmb(n); break;
430 case DASM_IMM_DB: if ((((unsigned)n+128)&-256) == 0) {
431 db: if (!mark) mark = cp; mark[-2] += 2; mark = NULL; goto wb;
432 } else mark = NULL;
433 /* fallthrough */
434 case DASM_IMM_D: wd: dasmd(n); break;
435 case DASM_IMM_WB: if ((((unsigned)n+128)&-256) == 0) goto db; else mark = NULL;
436 /* fallthrough */
437 case DASM_IMM_W: dasmw(n); break;
438 case DASM_VREG: {
439 int t = *p++;
440 unsigned char *ex = cp - (t&7);
441 if ((n & 8) && t < 0xa0) {
442 if (*ex & 0x80) ex[1] ^= 0x20 << (t>>6); else *ex ^= 1 << (t>>6);
443 n &= 7;
444 } else if (n & 0x10) {
445 if (*ex & 0x80) {
446 *ex = 0xc5; ex[1] = (ex[1] & 0x80) | ex[2]; ex += 2;
447 }
448 while (++ex < cp) ex[-1] = *ex;
449 if (mark) mark--;
450 cp--;
451 n &= 7;
452 }
453 if (t >= 0xc0) n <<= 4;
454 else if (t >= 0x40) n <<= 3;
455 else if (n == 4 && t < 0x20) { cp[-1] ^= n; *cp++ = 0x20; }
456 cp[-1] ^= n;
457 break;
458 }
459 case DASM_REL_LG: p++; if (n >= 0) goto rel_pc;
460 b++; n = (int)(ptrdiff_t)D->globals[-n];
461 /* fallthrough */
462 case DASM_REL_A: rel_a:
463 n -= (unsigned int)(ptrdiff_t)(cp+4); goto wd; /* !x64 */
464 case DASM_REL_PC: rel_pc: {
465 int shrink = *b++;
466 int *pb = DASM_POS2PTR(D, n); if (*pb < 0) { n = pb[1]; goto rel_a; }
467 n = *pb - ((int)(cp-base) + 4-shrink);
468 if (shrink == 0) goto wd;
469 if (shrink == 4) { cp--; cp[-1] = *cp-0x10; } else cp[-1] = 0xeb;
470 goto wb;
471 }
472 case DASM_IMM_LG:
473 p++;
474 if (n < 0) { dasma((ptrdiff_t)D->globals[-n]); break; }
475 /* fallthrough */
476 case DASM_IMM_PC: {
477 int *pb = DASM_POS2PTR(D, n);
478 dasma(*pb < 0 ? (ptrdiff_t)pb[1] : (*pb + (ptrdiff_t)base));
479 break;
480 }
481 case DASM_LABEL_LG: {
482 int idx = *p++;
483 if (idx >= 10)
484 D->globals[idx] = (void *)(base + (*p == DASM_SETLABEL ? *b : n));
485 break;
486 }
487 case DASM_LABEL_PC: case DASM_SETLABEL: break;
488 case DASM_SPACE: { int fill = *p++; while (n--) *cp++ = fill; break; }
489 case DASM_ALIGN:
490 n = *p++;
491 while (((cp-base) & n)) *cp++ = 0x90; /* nop */
492 break;
493 case DASM_EXTERN: n = DASM_EXTERN(Dst, cp, p[1], *p); p += 2; goto wd;
494 case DASM_MARK: mark = cp; break;
495 case DASM_ESC: action = *p++;
496 /* fallthrough */
497 default: *cp++ = action; break;
498 case DASM_SECTION: case DASM_STOP: goto stop;
499 }
500 }
501 stop: (void)0;
502 }
503 }
504
505 if (base + D->codesize != cp) /* Check for phase errors. */
506 return DASM_S_PHASE;
507 return DASM_S_OK;
508 }
509
510 /* Get PC label offset. */
dasm_getpclabel(Dst_DECL,unsigned int pc)511 int dasm_getpclabel(Dst_DECL, unsigned int pc)
512 {
513 dasm_State *D = Dst_REF;
514 if (pc*sizeof(int) < D->pcsize) {
515 int pos = D->pclabels[pc];
516 if (pos < 0) return *DASM_POS2PTR(D, -pos);
517 if (pos > 0) return -1; /* Undefined. */
518 }
519 return -2; /* Unused or out of range. */
520 }
521
522 #ifdef DASM_CHECKS
523 /* Optional sanity checker to call between isolated encoding steps. */
dasm_checkstep(Dst_DECL,int secmatch)524 int dasm_checkstep(Dst_DECL, int secmatch)
525 {
526 dasm_State *D = Dst_REF;
527 if (D->status == DASM_S_OK) {
528 int i;
529 for (i = 1; i <= 9; i++) {
530 if (D->lglabels[i] > 0) { D->status = DASM_S_UNDEF_L|i; break; }
531 D->lglabels[i] = 0;
532 }
533 }
534 if (D->status == DASM_S_OK && secmatch >= 0 &&
535 D->section != &D->sections[secmatch])
536 D->status = DASM_S_MATCH_SEC|(int)(D->section-D->sections);
537 return D->status;
538 }
539 #endif
540
541
