little optimization to crt1
[tinycc.git] / tccelf.c
1 /*
2 * ELF file handling for TCC
3 *
4 * Copyright (c) 2001-2004 Fabrice Bellard
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 */
20
21 #include "tcc.h"
22
23 /* Define this to get some debug output during relocation processing. */
24 #undef DEBUG_RELOC
25
26 /* XXX: avoid static variable */
27 static int new_undef_sym = 0; /* Is there a new undefined sym since last new_undef_sym() */
28
29 ST_FUNC int put_elf_str(Section *s, const char *sym)
30 {
31 int offset, len;
32 char *ptr;
33
34 len = strlen(sym) + 1;
35 offset = s->data_offset;
36 ptr = section_ptr_add(s, len);
37 memcpy(ptr, sym, len);
38 return offset;
39 }
40
41 /* elf symbol hashing function */
42 static unsigned long elf_hash(const unsigned char *name)
43 {
44 unsigned long h = 0, g;
45
46 while (*name) {
47 h = (h << 4) + *name++;
48 g = h & 0xf0000000;
49 if (g)
50 h ^= g >> 24;
51 h &= ~g;
52 }
53 return h;
54 }
55
56 /* rebuild hash table of section s */
57 /* NOTE: we do factorize the hash table code to go faster */
58 static void rebuild_hash(Section *s, unsigned int nb_buckets)
59 {
60 ElfW(Sym) *sym;
61 int *ptr, *hash, nb_syms, sym_index, h;
62 unsigned char *strtab;
63
64 strtab = s->link->data;
65 nb_syms = s->data_offset / sizeof(ElfW(Sym));
66
67 s->hash->data_offset = 0;
68 ptr = section_ptr_add(s->hash, (2 + nb_buckets + nb_syms) * sizeof(int));
69 ptr[0] = nb_buckets;
70 ptr[1] = nb_syms;
71 ptr += 2;
72 hash = ptr;
73 memset(hash, 0, (nb_buckets + 1) * sizeof(int));
74 ptr += nb_buckets + 1;
75
76 sym = (ElfW(Sym) *)s->data + 1;
77 for(sym_index = 1; sym_index < nb_syms; sym_index++) {
78 if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
79 h = elf_hash(strtab + sym->st_name) % nb_buckets;
80 *ptr = hash[h];
81 hash[h] = sym_index;
82 } else {
83 *ptr = 0;
84 }
85 ptr++;
86 sym++;
87 }
88 }
89
90 /* return the symbol number */
91 ST_FUNC int put_elf_sym(Section *s, addr_t value, unsigned long size,
92 int info, int other, int shndx, const char *name)
93 {
94 int name_offset, sym_index;
95 int nbuckets, h;
96 ElfW(Sym) *sym;
97 Section *hs;
98
99 sym = section_ptr_add(s, sizeof(ElfW(Sym)));
100 if (name)
101 name_offset = put_elf_str(s->link, name);
102 else
103 name_offset = 0;
104 /* XXX: endianness */
105 sym->st_name = name_offset;
106 sym->st_value = value;
107 sym->st_size = size;
108 sym->st_info = info;
109 sym->st_other = other;
110 sym->st_shndx = shndx;
111 sym_index = sym - (ElfW(Sym) *)s->data;
112 hs = s->hash;
113 if (hs) {
114 int *ptr, *base;
115 ptr = section_ptr_add(hs, sizeof(int));
116 base = (int *)hs->data;
117 /* only add global or weak symbols */
118 if (ELFW(ST_BIND)(info) != STB_LOCAL) {
119 /* add another hashing entry */
120 nbuckets = base[0];
121 h = elf_hash((unsigned char *) name) % nbuckets;
122 *ptr = base[2 + h];
123 base[2 + h] = sym_index;
124 base[1]++;
125 /* we resize the hash table */
126 hs->nb_hashed_syms++;
127 if (hs->nb_hashed_syms > 2 * nbuckets) {
128 rebuild_hash(s, 2 * nbuckets);
129 }
130 } else {
131 *ptr = 0;
132 base[1]++;
133 }
134 }
135 return sym_index;
136 }
137
138 /* find global ELF symbol 'name' and return its index. Return 0 if not
139 found. */
140 ST_FUNC int find_elf_sym(Section *s, const char *name)
141 {
142 ElfW(Sym) *sym;
143 Section *hs;
144 int nbuckets, sym_index, h;
145 const char *name1;
146
147 hs = s->hash;
148 if (!hs)
149 return 0;
150 nbuckets = ((int *)hs->data)[0];
151 h = elf_hash((unsigned char *) name) % nbuckets;
152 sym_index = ((int *)hs->data)[2 + h];
153 while (sym_index != 0) {
154 sym = &((ElfW(Sym) *)s->data)[sym_index];
155 name1 = (char *) s->link->data + sym->st_name;
156 if (!strcmp(name, name1))
157 return sym_index;
158 sym_index = ((int *)hs->data)[2 + nbuckets + sym_index];
159 }
160 return 0;
161 }
162
163 /* return elf symbol value, signal error if 'err' is nonzero */
164 ST_FUNC addr_t get_elf_sym_addr(TCCState *s, const char *name, int err)
165 {
166 int sym_index;
167 ElfW(Sym) *sym;
168
169 sym_index = find_elf_sym(s->symtab, name);
170 sym = &((ElfW(Sym) *)s->symtab->data)[sym_index];
171 if (!sym_index || sym->st_shndx == SHN_UNDEF) {
172 if (err)
173 tcc_error("%s not defined", name);
174 return 0;
175 }
176 return sym->st_value;
177 }
178
179 /* return elf symbol value */
180 LIBTCCAPI void *tcc_get_symbol(TCCState *s, const char *name)
181 {
182 return (void*)(uintptr_t)get_elf_sym_addr(s, name, 0);
183 }
184
185 #if defined TCC_IS_NATIVE || defined TCC_TARGET_PE
186 /* return elf symbol value or error */
187 ST_FUNC void* tcc_get_symbol_err(TCCState *s, const char *name)
188 {
189 return (void*)(uintptr_t)get_elf_sym_addr(s, name, 1);
190 }
191 #endif
192
193 /* add an elf symbol : check if it is already defined and patch
194 it. Return symbol index. NOTE that sh_num can be SHN_UNDEF. */
195 ST_FUNC int add_elf_sym(Section *s, addr_t value, unsigned long size,
196 int info, int other, int sh_num, const char *name)
197 {
198 ElfW(Sym) *esym;
199 int sym_bind, sym_index, sym_type, esym_bind;
200 unsigned char sym_vis, esym_vis, new_vis;
201
202 sym_bind = ELFW(ST_BIND)(info);
203 sym_type = ELFW(ST_TYPE)(info);
204 sym_vis = ELFW(ST_VISIBILITY)(other);
205
206 if (sym_bind != STB_LOCAL) {
207 /* we search global or weak symbols */
208 sym_index = find_elf_sym(s, name);
209 if (!sym_index)
210 goto do_def;
211 esym = &((ElfW(Sym) *)s->data)[sym_index];
212 if (esym->st_shndx != SHN_UNDEF) {
213 esym_bind = ELFW(ST_BIND)(esym->st_info);
214 /* propagate the most constraining visibility */
215 /* STV_DEFAULT(0)<STV_PROTECTED(3)<STV_HIDDEN(2)<STV_INTERNAL(1) */
216 esym_vis = ELFW(ST_VISIBILITY)(esym->st_other);
217 if (esym_vis == STV_DEFAULT) {
218 new_vis = sym_vis;
219 } else if (sym_vis == STV_DEFAULT) {
220 new_vis = esym_vis;
221 } else {
222 new_vis = (esym_vis < sym_vis) ? esym_vis : sym_vis;
223 }
224 esym->st_other = (esym->st_other & ~ELFW(ST_VISIBILITY)(-1))
225 | new_vis;
226 other = esym->st_other; /* in case we have to patch esym */
227 if (sh_num == SHN_UNDEF) {
228 /* ignore adding of undefined symbol if the
229 corresponding symbol is already defined */
230 } else if (sym_bind == STB_GLOBAL && esym_bind == STB_WEAK) {
231 /* global overrides weak, so patch */
232 goto do_patch;
233 } else if (sym_bind == STB_WEAK && esym_bind == STB_GLOBAL) {
234 /* weak is ignored if already global */
235 } else if (sym_bind == STB_WEAK && esym_bind == STB_WEAK) {
236 /* keep first-found weak definition, ignore subsequents */
237 } else if (sym_vis == STV_HIDDEN || sym_vis == STV_INTERNAL) {
238 /* ignore hidden symbols after */
239 } else if (esym->st_shndx == SHN_COMMON
240 && (sh_num < SHN_LORESERVE || sh_num == SHN_COMMON)) {
241 /* gr: Happens with 'tcc ... -static tcctest.c' on e.g. Ubuntu 6.01
242 No idea if this is the correct solution ... */
243 goto do_patch;
244 } else if (s == tcc_state->dynsymtab_section) {
245 /* we accept that two DLL define the same symbol */
246 } else {
247 #if 0
248 printf("new_bind=%x new_shndx=%x new_vis=%x old_bind=%x old_shndx=%x old_vis=%x\n",
249 sym_bind, sh_num, new_vis, esym_bind, esym->st_shndx, esym_vis);
250 #endif
251 tcc_error_noabort("'%s' defined twice", name);
252 }
253 } else {
254 do_patch:
255 esym->st_info = ELFW(ST_INFO)(sym_bind, sym_type);
256 esym->st_shndx = sh_num;
257 new_undef_sym = 1;
258 esym->st_value = value;
259 esym->st_size = size;
260 esym->st_other = other;
261 }
262 } else {
263 do_def:
264 sym_index = put_elf_sym(s, value, size,
265 ELFW(ST_INFO)(sym_bind, sym_type), other,
266 sh_num, name);
267 }
268 return sym_index;
269 }
270
271 /* put relocation */
272 ST_FUNC void put_elf_reloc(Section *symtab, Section *s, unsigned long offset,
273 int type, int symbol)
274 {
275 char buf[256];
276 Section *sr;
277 ElfW_Rel *rel;
278
279 sr = s->reloc;
280 if (!sr) {
281 /* if no relocation section, create it */
282 snprintf(buf, sizeof(buf), REL_SECTION_FMT, s->name);
283 /* if the symtab is allocated, then we consider the relocation
284 are also */
285 sr = new_section(tcc_state, buf, SHT_RELX, symtab->sh_flags);
286 sr->sh_entsize = sizeof(ElfW_Rel);
287 sr->link = symtab;
288 sr->sh_info = s->sh_num;
289 s->reloc = sr;
290 }
291 rel = section_ptr_add(sr, sizeof(ElfW_Rel));
292 rel->r_offset = offset;
293 rel->r_info = ELFW(R_INFO)(symbol, type);
294 #ifdef TCC_TARGET_X86_64
295 rel->r_addend = 0;
296 #endif
297 }
298
299 /* put stab debug information */
300
301 ST_FUNC void put_stabs(const char *str, int type, int other, int desc,
302 unsigned long value)
303 {
304 Stab_Sym *sym;
305
306 sym = section_ptr_add(stab_section, sizeof(Stab_Sym));
307 if (str) {
308 sym->n_strx = put_elf_str(stabstr_section, str);
309 } else {
310 sym->n_strx = 0;
311 }
312 sym->n_type = type;
313 sym->n_other = other;
314 sym->n_desc = desc;
315 sym->n_value = value;
316 }
317
318 ST_FUNC void put_stabs_r(const char *str, int type, int other, int desc,
319 unsigned long value, Section *sec, int sym_index)
320 {
321 put_stabs(str, type, other, desc, value);
322 put_elf_reloc(symtab_section, stab_section,
323 stab_section->data_offset - sizeof(unsigned int),
324 R_DATA_32, sym_index);
325 }
326
327 ST_FUNC void put_stabn(int type, int other, int desc, int value)
328 {
329 put_stabs(NULL, type, other, desc, value);
330 }
331
332 ST_FUNC void put_stabd(int type, int other, int desc)
333 {
334 put_stabs(NULL, type, other, desc, 0);
335 }
336
337 /* Browse each elem of type <type> in section <sec> starting at elem <startoff>
338 using variable <elem> */
339 #define for_each_elem(sec, startoff, elem, type) \
340 for (elem = (type *) sec->data + startoff; \
341 elem < (type *) (sec->data + sec->data_offset); elem++)
342
343 /* In an ELF file symbol table, the local symbols must appear below
344 the global and weak ones. Since TCC cannot sort it while generating
345 the code, we must do it after. All the relocation tables are also
346 modified to take into account the symbol table sorting */
347 static void sort_syms(TCCState *s1, Section *s)
348 {
349 int *old_to_new_syms;
350 ElfW(Sym) *new_syms;
351 int nb_syms, i;
352 ElfW(Sym) *p, *q;
353 ElfW_Rel *rel;
354 Section *sr;
355 int type, sym_index;
356
357 nb_syms = s->data_offset / sizeof(ElfW(Sym));
358 new_syms = tcc_malloc(nb_syms * sizeof(ElfW(Sym)));
359 old_to_new_syms = tcc_malloc(nb_syms * sizeof(int));
360
361 /* first pass for local symbols */
362 p = (ElfW(Sym) *)s->data;
363 q = new_syms;
364 for(i = 0; i < nb_syms; i++) {
365 if (ELFW(ST_BIND)(p->st_info) == STB_LOCAL) {
366 old_to_new_syms[i] = q - new_syms;
367 *q++ = *p;
368 }
369 p++;
370 }
371 /* save the number of local symbols in section header */
372 s->sh_info = q - new_syms;
373
374 /* then second pass for non local symbols */
375 p = (ElfW(Sym) *)s->data;
376 for(i = 0; i < nb_syms; i++) {
377 if (ELFW(ST_BIND)(p->st_info) != STB_LOCAL) {
378 old_to_new_syms[i] = q - new_syms;
379 *q++ = *p;
380 }
381 p++;
382 }
383
384 /* we copy the new symbols to the old */
385 memcpy(s->data, new_syms, nb_syms * sizeof(ElfW(Sym)));
386 tcc_free(new_syms);
387
388 /* now we modify all the relocations */
389 for(i = 1; i < s1->nb_sections; i++) {
390 sr = s1->sections[i];
391 if (sr->sh_type == SHT_RELX && sr->link == s) {
392 for_each_elem(sr, 0, rel, ElfW_Rel) {
393 sym_index = ELFW(R_SYM)(rel->r_info);
394 type = ELFW(R_TYPE)(rel->r_info);
395 sym_index = old_to_new_syms[sym_index];
396 rel->r_info = ELFW(R_INFO)(sym_index, type);
397 }
398 }
399 }
400
401 tcc_free(old_to_new_syms);
402 }
403
404 /* relocate common symbols in the .bss section */
405 ST_FUNC void relocate_common_syms(void)
406 {
407 ElfW(Sym) *sym;
408 unsigned long offset, align;
409
410 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
411 if (sym->st_shndx == SHN_COMMON) {
412 /* align symbol */
413 align = sym->st_value;
414 offset = bss_section->data_offset;
415 offset = (offset + align - 1) & -align;
416 sym->st_value = offset;
417 sym->st_shndx = bss_section->sh_num;
418 offset += sym->st_size;
419 bss_section->data_offset = offset;
420 }
421 }
422 }
423
424 /* relocate symbol table, resolve undefined symbols if do_resolve is
425 true and output error if undefined symbol. */
426 ST_FUNC void relocate_syms(TCCState *s1, int do_resolve)
427 {
428 ElfW(Sym) *sym, *esym;
429 int sym_bind, sh_num, sym_index;
430 const char *name;
431
432 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
433 sh_num = sym->st_shndx;
434 if (sh_num == SHN_UNDEF) {
435 name = (char *) strtab_section->data + sym->st_name;
436 /* Use ld.so to resolve symbol for us (for tcc -run) */
437 if (do_resolve) {
438 #if defined TCC_IS_NATIVE && !defined _WIN32
439 void *addr;
440 name = (char *) symtab_section->link->data + sym->st_name;
441 addr = resolve_sym(s1, name);
442 if (addr) {
443 sym->st_value = (addr_t)addr;
444 #ifdef DEBUG_RELOC
445 printf ("relocate_sym: %s -> 0x%x\n", name, sym->st_value);
446 #endif
447 goto found;
448 }
449 #endif
450 } else if (s1->dynsym) {
451 /* if dynamic symbol exist, then use it */
452 sym_index = find_elf_sym(s1->dynsym, name);
453 if (sym_index) {
454 esym = &((ElfW(Sym) *)s1->dynsym->data)[sym_index];
455 sym->st_value = esym->st_value;
456 goto found;
457 }
458 }
459 /* XXX: _fp_hw seems to be part of the ABI, so we ignore
460 it */
461 if (!strcmp(name, "_fp_hw"))
462 goto found;
463 /* only weak symbols are accepted to be undefined. Their
464 value is zero */
465 sym_bind = ELFW(ST_BIND)(sym->st_info);
466 if (sym_bind == STB_WEAK) {
467 sym->st_value = 0;
468 } else {
469 tcc_error_noabort("undefined symbol '%s'", name);
470 }
471 } else if (sh_num < SHN_LORESERVE) {
472 /* add section base */
473 sym->st_value += s1->sections[sym->st_shndx]->sh_addr;
474 }
475 found: ;
476 }
477 }
478
479 /* relocate a given section (CPU dependent) by applying the relocations
480 in the associated relocation section */
481 ST_FUNC void relocate_section(TCCState *s1, Section *s)
482 {
483 Section *sr = s->reloc;
484 ElfW_Rel *rel;
485 ElfW(Sym) *sym;
486 int type, sym_index;
487 unsigned char *ptr;
488 addr_t val, addr;
489 #if defined TCC_TARGET_I386 || defined TCC_TARGET_X86_64
490 ElfW_Rel *qrel = (ElfW_Rel *) sr->data; /* ptr to next reloc entry reused */
491 int esym_index;
492 #endif
493
494 for_each_elem(sr, 0, rel, ElfW_Rel) {
495 ptr = s->data + rel->r_offset;
496
497 sym_index = ELFW(R_SYM)(rel->r_info);
498 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
499 val = sym->st_value;
500 #ifdef TCC_TARGET_X86_64
501 val += rel->r_addend;
502 #endif
503 type = ELFW(R_TYPE)(rel->r_info);
504 addr = s->sh_addr + rel->r_offset;
505
506 /* CPU specific */
507 switch(type) {
508 #if defined(TCC_TARGET_I386)
509 case R_386_32:
510 if (s1->output_type == TCC_OUTPUT_DLL) {
511 esym_index = s1->symtab_to_dynsym[sym_index];
512 qrel->r_offset = rel->r_offset;
513 if (esym_index) {
514 qrel->r_info = ELFW(R_INFO)(esym_index, R_386_32);
515 qrel++;
516 break;
517 } else {
518 qrel->r_info = ELFW(R_INFO)(0, R_386_RELATIVE);
519 qrel++;
520 }
521 }
522 *(int *)ptr += val;
523 break;
524 case R_386_PC32:
525 if (s1->output_type == TCC_OUTPUT_DLL) {
526 /* DLL relocation */
527 esym_index = s1->symtab_to_dynsym[sym_index];
528 if (esym_index) {
529 qrel->r_offset = rel->r_offset;
530 qrel->r_info = ELFW(R_INFO)(esym_index, R_386_PC32);
531 qrel++;
532 break;
533 }
534 }
535 *(int *)ptr += val - addr;
536 break;
537 case R_386_PLT32:
538 *(int *)ptr += val - addr;
539 break;
540 case R_386_GLOB_DAT:
541 case R_386_JMP_SLOT:
542 *(int *)ptr = val;
543 break;
544 case R_386_GOTPC:
545 *(int *)ptr += s1->got->sh_addr - addr;
546 break;
547 case R_386_GOTOFF:
548 *(int *)ptr += val - s1->got->sh_addr;
549 break;
550 case R_386_GOT32:
551 /* we load the got offset */
552 *(int *)ptr += s1->sym_attrs[sym_index].got_offset;
553 break;
554 case R_386_16:
555 if (s1->output_format != TCC_OUTPUT_FORMAT_BINARY) {
556 output_file:
557 tcc_error("can only produce 16-bit binary files");
558 }
559 *(short *)ptr += val;
560 break;
561 case R_386_PC16:
562 if (s1->output_format != TCC_OUTPUT_FORMAT_BINARY)
563 goto output_file;
564 *(short *)ptr += val - addr;
565 break;
566 #elif defined(TCC_TARGET_ARM)
567 case R_ARM_PC24:
568 case R_ARM_CALL:
569 case R_ARM_JUMP24:
570 case R_ARM_PLT32:
571 {
572 int x, is_thumb, is_call, h, blx_avail, is_bl, th_ko;
573 x = (*(int *) ptr) & 0xffffff;
574 if (sym->st_shndx == SHN_UNDEF)
575 val = s1->plt->sh_addr;
576 #ifdef DEBUG_RELOC
577 printf ("reloc %d: x=0x%x val=0x%x ", type, x, val);
578 #endif
579 (*(int *)ptr) &= 0xff000000;
580 if (x & 0x800000)
581 x -= 0x1000000;
582 x <<= 2;
583 blx_avail = (TCC_ARM_VERSION >= 5);
584 is_thumb = val & 1;
585 is_bl = (*(unsigned *) ptr) >> 24 == 0xeb;
586 is_call = (type == R_ARM_CALL || (type == R_ARM_PC24 && is_bl));
587 x += val - addr;
588 #ifdef DEBUG_RELOC
589 printf (" newx=0x%x name=%s\n", x,
590 (char *) symtab_section->link->data + sym->st_name);
591 #endif
592 h = x & 2;
593 th_ko = (x & 3) && (!blx_avail || !is_call);
594 if (th_ko || x >= 0x2000000 || x < -0x2000000)
595 tcc_error("can't relocate value at %x,%d",addr, type);
596 x >>= 2;
597 x &= 0xffffff;
598 /* Only reached if blx is avail and it is a call */
599 if (is_thumb) {
600 x |= h << 24;
601 (*(int *)ptr) = 0xfa << 24; /* bl -> blx */
602 }
603 (*(int *) ptr) |= x;
604 }
605 break;
606 /* Since these relocations only concern Thumb-2 and blx instruction was
607 introduced before Thumb-2, we can assume blx is available and not
608 guard its use */
609 case R_ARM_THM_PC22:
610 case R_ARM_THM_JUMP24:
611 {
612 int x, hi, lo, s, j1, j2, i1, i2, imm10, imm11;
613 int to_thumb, is_call, to_plt, blx_bit = 1 << 12;
614 Section *plt;
615
616 /* weak reference */
617 if (sym->st_shndx == SHN_UNDEF &&
618 ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
619 break;
620
621 /* Get initial offset */
622 hi = (*(uint16_t *)ptr);
623 lo = (*(uint16_t *)(ptr+2));
624 s = (hi >> 10) & 1;
625 j1 = (lo >> 13) & 1;
626 j2 = (lo >> 11) & 1;
627 i1 = (j1 ^ s) ^ 1;
628 i2 = (j2 ^ s) ^ 1;
629 imm10 = hi & 0x3ff;
630 imm11 = lo & 0x7ff;
631 x = (s << 24) | (i1 << 23) | (i2 << 22) |
632 (imm10 << 12) | (imm11 << 1);
633 if (x & 0x01000000)
634 x -= 0x02000000;
635
636 /* Relocation infos */
637 to_thumb = val & 1;
638 plt = s1->plt;
639 to_plt = (val >= plt->sh_addr) &&
640 (val < plt->sh_addr + plt->data_offset);
641 is_call = (type == R_ARM_THM_PC22);
642
643 /* Compute final offset */
644 if (to_plt && !is_call) /* Point to 1st instr of Thumb stub */
645 x -= 4;
646 x += val - addr;
647 if (!to_thumb && is_call) {
648 blx_bit = 0; /* bl -> blx */
649 x = (x + 3) & -4; /* Compute offset from aligned PC */
650 }
651
652 /* Check that relocation is possible
653 * offset must not be out of range
654 * if target is to be entered in arm mode:
655 - bit 1 must not set
656 - instruction must be a call (bl) or a jump to PLT */
657 if (!to_thumb || x >= 0x1000000 || x < -0x1000000)
658 if (to_thumb || (val & 2) || (!is_call && !to_plt))
659 tcc_error("can't relocate value at %x,%d",addr, type);
660
661 /* Compute and store final offset */
662 s = (x >> 24) & 1;
663 i1 = (x >> 23) & 1;
664 i2 = (x >> 22) & 1;
665 j1 = s ^ (i1 ^ 1);
666 j2 = s ^ (i2 ^ 1);
667 imm10 = (x >> 12) & 0x3ff;
668 imm11 = (x >> 1) & 0x7ff;
669 (*(uint16_t *)ptr) = (uint16_t) ((hi & 0xf800) |
670 (s << 10) | imm10);
671 (*(uint16_t *)(ptr+2)) = (uint16_t) ((lo & 0xc000) |
672 (j1 << 13) | blx_bit | (j2 << 11) |
673 imm11);
674 }
675 break;
676 case R_ARM_MOVT_ABS:
677 case R_ARM_MOVW_ABS_NC:
678 {
679 int x, imm4, imm12;
680 if (type == R_ARM_MOVT_ABS)
681 val >>= 16;
682 imm12 = val & 0xfff;
683 imm4 = (val >> 12) & 0xf;
684 x = (imm4 << 16) | imm12;
685 if (type == R_ARM_THM_MOVT_ABS)
686 *(int *)ptr |= x;
687 else
688 *(int *)ptr += x;
689 }
690 break;
691 case R_ARM_THM_MOVT_ABS:
692 case R_ARM_THM_MOVW_ABS_NC:
693 {
694 int x, i, imm4, imm3, imm8;
695 if (type == R_ARM_THM_MOVT_ABS)
696 val >>= 16;
697 imm8 = val & 0xff;
698 imm3 = (val >> 8) & 0x7;
699 i = (val >> 11) & 1;
700 imm4 = (val >> 12) & 0xf;
701 x = (imm3 << 28) | (imm8 << 16) | (i << 10) | imm4;
702 if (type == R_ARM_THM_MOVT_ABS)
703 *(int *)ptr |= x;
704 else
705 *(int *)ptr += x;
706 }
707 break;
708 case R_ARM_PREL31:
709 {
710 int x;
711 x = (*(int *)ptr) & 0x7fffffff;
712 (*(int *)ptr) &= 0x80000000;
713 x = (x * 2) / 2;
714 x += val - addr;
715 if((x^(x>>1))&0x40000000)
716 tcc_error("can't relocate value at %x,%d",addr, type);
717 (*(int *)ptr) |= x & 0x7fffffff;
718 }
719 case R_ARM_ABS32:
720 *(int *)ptr += val;
721 break;
722 case R_ARM_REL32:
723 *(int *)ptr += val - addr;
724 break;
725 case R_ARM_GOTPC:
726 *(int *)ptr += s1->got->sh_addr - addr;
727 break;
728 case R_ARM_GOTOFF:
729 *(int *)ptr += val - s1->got->sh_addr;
730 break;
731 case R_ARM_GOT32:
732 /* we load the got offset */
733 *(int *)ptr += s1->sym_attrs[sym_index].got_offset;
734 break;
735 case R_ARM_COPY:
736 break;
737 case R_ARM_V4BX:
738 /* trade Thumb support for ARMv4 support */
739 if ((0x0ffffff0 & *(int*)ptr) == 0x012FFF10)
740 *(int*)ptr ^= 0xE12FFF10 ^ 0xE1A0F000; /* BX Rm -> MOV PC, Rm */
741 break;
742 case R_ARM_GLOB_DAT:
743 case R_ARM_JUMP_SLOT:
744 *(addr_t *)ptr = val;
745 break;
746 case R_ARM_NONE:
747 /* Nothing to do. Normally used to indicate a dependency
748 on a certain symbol (like for exception handling under EABI). */
749 break;
750 default:
751 fprintf(stderr,"FIXME: handle reloc type %x at %x [%p] to %x\n",
752 type, (unsigned)addr, ptr, (unsigned)val);
753 break;
754 #elif defined(TCC_TARGET_C67)
755 case R_C60_32:
756 *(int *)ptr += val;
757 break;
758 case R_C60LO16:
759 {
760 uint32_t orig;
761
762 /* put the low 16 bits of the absolute address
763 add to what is already there */
764
765 orig = ((*(int *)(ptr )) >> 7) & 0xffff;
766 orig |= (((*(int *)(ptr+4)) >> 7) & 0xffff) << 16;
767
768 /* patch both at once - assumes always in pairs Low - High */
769
770 *(int *) ptr = (*(int *) ptr & (~(0xffff << 7)) ) | (((val+orig) & 0xffff) << 7);
771 *(int *)(ptr+4) = (*(int *)(ptr+4) & (~(0xffff << 7)) ) | ((((val+orig)>>16) & 0xffff) << 7);
772 }
773 break;
774 case R_C60HI16:
775 break;
776 default:
777 fprintf(stderr,"FIXME: handle reloc type %x at %x [%p] to %x\n",
778 type, (unsigned)addr, ptr, (unsigned)val);
779 break;
780 #elif defined(TCC_TARGET_X86_64)
781 case R_X86_64_64:
782 if (s1->output_type == TCC_OUTPUT_DLL) {
783 esym_index = s1->symtab_to_dynsym[sym_index];
784 qrel->r_offset = rel->r_offset;
785 if (esym_index) {
786 qrel->r_info = ELFW(R_INFO)(esym_index, R_X86_64_64);
787 qrel->r_addend = rel->r_addend;
788 qrel++;
789 break;
790 } else {
791 qrel->r_info = ELFW(R_INFO)(0, R_X86_64_RELATIVE);
792 qrel->r_addend = *(long long *)ptr + val;
793 qrel++;
794 }
795 }
796 *(long long *)ptr += val;
797 break;
798 case R_X86_64_32:
799 case R_X86_64_32S:
800 if (s1->output_type == TCC_OUTPUT_DLL) {
801 /* XXX: this logic may depend on TCC's codegen
802 now TCC uses R_X86_64_32 even for a 64bit pointer */
803 qrel->r_info = ELFW(R_INFO)(0, R_X86_64_RELATIVE);
804 qrel->r_addend = *(int *)ptr + val;
805 qrel++;
806 }
807 *(int *)ptr += val;
808 break;
809
810 case R_X86_64_PC32:
811 if (s1->output_type == TCC_OUTPUT_DLL) {
812 /* DLL relocation */
813 esym_index = s1->symtab_to_dynsym[sym_index];
814 if (esym_index) {
815 qrel->r_offset = rel->r_offset;
816 qrel->r_info = ELFW(R_INFO)(esym_index, R_X86_64_PC32);
817 qrel->r_addend = *(int *)ptr;
818 qrel++;
819 break;
820 }
821 }
822 goto plt32pc32;
823
824 case R_X86_64_PLT32:
825 /* We've put the PLT slot offset into r_addend when generating
826 it, and that's what we must use as relocation value (adjusted
827 by section offset of course). */
828 val = s1->plt->sh_addr + rel->r_addend;
829 /* fallthrough. */
830
831 plt32pc32:
832 {
833 long long diff;
834 diff = (long long)val - addr;
835 if (diff <= -2147483647 || diff > 2147483647) {
836 tcc_error("internal error: relocation failed");
837 }
838 *(int *)ptr += diff;
839 }
840 break;
841 case R_X86_64_GLOB_DAT:
842 case R_X86_64_JUMP_SLOT:
843 /* They don't need addend */
844 *(addr_t *)ptr = val - rel->r_addend;
845 break;
846 case R_X86_64_GOTPCREL:
847 *(int *)ptr += (s1->got->sh_addr - addr +
848 s1->sym_attrs[sym_index].got_offset - 4);
849 break;
850 case R_X86_64_GOTTPOFF:
851 *(int *)ptr += val - s1->got->sh_addr;
852 break;
853 case R_X86_64_GOT32:
854 /* we load the got offset */
855 *(int *)ptr += s1->sym_attrs[sym_index].got_offset;
856 break;
857 #else
858 #error unsupported processor
859 #endif
860 }
861 }
862 /* if the relocation is allocated, we change its symbol table */
863 if (sr->sh_flags & SHF_ALLOC)
864 sr->link = s1->dynsym;
865 }
866
867 /* relocate relocation table in 'sr' */
868 static void relocate_rel(TCCState *s1, Section *sr)
869 {
870 Section *s;
871 ElfW_Rel *rel;
872
873 s = s1->sections[sr->sh_info];
874 for_each_elem(sr, 0, rel, ElfW_Rel)
875 rel->r_offset += s->sh_addr;
876 }
877
878 /* count the number of dynamic relocations so that we can reserve
879 their space */
880 static int prepare_dynamic_rel(TCCState *s1, Section *sr)
881 {
882 ElfW_Rel *rel;
883 int sym_index, esym_index, type, count;
884
885 count = 0;
886 for_each_elem(sr, 0, rel, ElfW_Rel) {
887 sym_index = ELFW(R_SYM)(rel->r_info);
888 type = ELFW(R_TYPE)(rel->r_info);
889 switch(type) {
890 #if defined(TCC_TARGET_I386)
891 case R_386_32:
892 #elif defined(TCC_TARGET_X86_64)
893 case R_X86_64_32:
894 case R_X86_64_32S:
895 case R_X86_64_64:
896 #endif
897 count++;
898 break;
899 #if defined(TCC_TARGET_I386)
900 case R_386_PC32:
901 #elif defined(TCC_TARGET_X86_64)
902 case R_X86_64_PC32:
903 #endif
904 esym_index = s1->symtab_to_dynsym[sym_index];
905 if (esym_index)
906 count++;
907 break;
908 default:
909 break;
910 }
911 }
912 if (count) {
913 /* allocate the section */
914 sr->sh_flags |= SHF_ALLOC;
915 sr->sh_size = count * sizeof(ElfW_Rel);
916 }
917 return count;
918 }
919
920 static struct sym_attr *alloc_sym_attr(TCCState *s1, int index)
921 {
922 int n;
923 struct sym_attr *tab;
924
925 if (index >= s1->nb_sym_attrs) {
926 /* find immediately bigger power of 2 and reallocate array */
927 n = 1;
928 while (index >= n)
929 n *= 2;
930 tab = tcc_realloc(s1->sym_attrs, n * sizeof(*s1->sym_attrs));
931 s1->sym_attrs = tab;
932 memset(s1->sym_attrs + s1->nb_sym_attrs, 0,
933 (n - s1->nb_sym_attrs) * sizeof(*s1->sym_attrs));
934 s1->nb_sym_attrs = n;
935 }
936 return &s1->sym_attrs[index];
937 }
938
939 /* XXX: suppress that */
940 static void put32(unsigned char *p, uint32_t val)
941 {
942 p[0] = val;
943 p[1] = val >> 8;
944 p[2] = val >> 16;
945 p[3] = val >> 24;
946 }
947
948 #if defined(TCC_TARGET_I386) || defined(TCC_TARGET_ARM) || \
949 defined(TCC_TARGET_X86_64)
950 static uint32_t get32(unsigned char *p)
951 {
952 return p[0] | (p[1] << 8) | (p[2] << 16) | (p[3] << 24);
953 }
954 #endif
955
956 static void build_got(TCCState *s1)
957 {
958 unsigned char *ptr;
959
960 /* if no got, then create it */
961 s1->got = new_section(s1, ".got", SHT_PROGBITS, SHF_ALLOC | SHF_WRITE);
962 s1->got->sh_entsize = 4;
963 add_elf_sym(symtab_section, 0, 4, ELFW(ST_INFO)(STB_GLOBAL, STT_OBJECT),
964 0, s1->got->sh_num, "_GLOBAL_OFFSET_TABLE_");
965 ptr = section_ptr_add(s1->got, 3 * PTR_SIZE);
966 #if PTR_SIZE == 4
967 /* keep space for _DYNAMIC pointer, if present */
968 put32(ptr, 0);
969 /* two dummy got entries */
970 put32(ptr + 4, 0);
971 put32(ptr + 8, 0);
972 #else
973 /* keep space for _DYNAMIC pointer, if present */
974 put32(ptr, 0);
975 put32(ptr + 4, 0);
976 /* two dummy got entries */
977 put32(ptr + 8, 0);
978 put32(ptr + 12, 0);
979 put32(ptr + 16, 0);
980 put32(ptr + 20, 0);
981 #endif
982 }
983
984 /* put a got or plt entry corresponding to a symbol in symtab_section. 'size'
985 and 'info' can be modifed if more precise info comes from the DLL.
986 Returns offset of GOT or PLT slot. */
987 static unsigned long put_got_entry(TCCState *s1,
988 int reloc_type, unsigned long size, int info,
989 int sym_index)
990 {
991 int index, need_plt_entry;
992 const char *name;
993 ElfW(Sym) *sym;
994 unsigned long offset;
995 int *ptr;
996 struct sym_attr *symattr;
997
998 if (!s1->got)
999 build_got(s1);
1000
1001 need_plt_entry =
1002 #ifdef TCC_TARGET_X86_64
1003 (reloc_type == R_X86_64_JUMP_SLOT);
1004 #elif defined(TCC_TARGET_I386)
1005 (reloc_type == R_386_JMP_SLOT);
1006 #elif defined(TCC_TARGET_ARM)
1007 (reloc_type == R_ARM_JUMP_SLOT);
1008 #else
1009 0;
1010 #endif
1011
1012 if (need_plt_entry && !s1->plt) {
1013 /* add PLT */
1014 s1->plt = new_section(s1, ".plt", SHT_PROGBITS,
1015 SHF_ALLOC | SHF_EXECINSTR);
1016 s1->plt->sh_entsize = 4;
1017 }
1018
1019 /* If a got/plt entry already exists for that symbol, no need to add one */
1020 if (sym_index < s1->nb_sym_attrs) {
1021 if (need_plt_entry && s1->sym_attrs[sym_index].plt_offset)
1022 return s1->sym_attrs[sym_index].plt_offset;
1023 else if (!need_plt_entry && s1->sym_attrs[sym_index].got_offset)
1024 return s1->sym_attrs[sym_index].got_offset;
1025 }
1026
1027 symattr = alloc_sym_attr(s1, sym_index);
1028
1029 /* Only store the GOT offset if it's not generated for the PLT entry. */
1030 if (!need_plt_entry)
1031 symattr->got_offset = s1->got->data_offset;
1032
1033 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1034 name = (char *) symtab_section->link->data + sym->st_name;
1035 offset = sym->st_value;
1036 #if defined(TCC_TARGET_I386) || defined(TCC_TARGET_X86_64)
1037 if (need_plt_entry) {
1038 Section *plt;
1039 uint8_t *p;
1040 int modrm;
1041 unsigned long relofs;
1042
1043 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
1044 modrm = 0x25;
1045 #else
1046 /* if we build a DLL, we add a %ebx offset */
1047 if (s1->output_type == TCC_OUTPUT_DLL)
1048 modrm = 0xa3;
1049 else
1050 modrm = 0x25;
1051 #endif
1052
1053 /* add a PLT entry */
1054 plt = s1->plt;
1055 if (plt->data_offset == 0) {
1056 /* first plt entry */
1057 p = section_ptr_add(plt, 16);
1058 p[0] = 0xff; /* pushl got + PTR_SIZE */
1059 p[1] = modrm + 0x10;
1060 put32(p + 2, PTR_SIZE);
1061 p[6] = 0xff; /* jmp *(got + PTR_SIZE * 2) */
1062 p[7] = modrm;
1063 put32(p + 8, PTR_SIZE * 2);
1064 }
1065
1066 /* The PLT slot refers to the relocation entry it needs
1067 via offset. The reloc entry is created below, so its
1068 offset is the current data_offset. */
1069 relofs = s1->got->reloc ? s1->got->reloc->data_offset : 0;
1070 symattr->plt_offset = plt->data_offset;
1071 p = section_ptr_add(plt, 16);
1072 p[0] = 0xff; /* jmp *(got + x) */
1073 p[1] = modrm;
1074 put32(p + 2, s1->got->data_offset);
1075 p[6] = 0x68; /* push $xxx */
1076 #ifdef TCC_TARGET_X86_64
1077 /* On x86-64, the relocation is referred to by _index_. */
1078 put32(p + 7, relofs / sizeof (ElfW_Rel));
1079 #else
1080 put32(p + 7, relofs);
1081 #endif
1082 p[11] = 0xe9; /* jmp plt_start */
1083 put32(p + 12, -(plt->data_offset));
1084
1085 /* If this was an UNDEF symbol set the offset in the
1086 dynsymtab to the PLT slot, so that PC32 relocs to it
1087 can be resolved. */
1088 if (sym->st_shndx == SHN_UNDEF)
1089 offset = plt->data_offset - 16;
1090 }
1091 #elif defined(TCC_TARGET_ARM)
1092 if (need_plt_entry) {
1093 Section *plt;
1094 uint8_t *p;
1095
1096 /* if we build a DLL, we add a %ebx offset */
1097 if (s1->output_type == TCC_OUTPUT_DLL)
1098 tcc_error("DLLs unimplemented!");
1099
1100 /* add a PLT entry */
1101 plt = s1->plt;
1102 if (plt->data_offset == 0) {
1103 /* first plt entry */
1104 p = section_ptr_add(plt, 16);
1105 put32(p, 0xe52de004); /* push {lr} */
1106 put32(p+4, 0xe59fe010); /* ldr lr, [pc, #16] */
1107 put32(p+8, 0xe08fe00e); /* add lr, pc, lr */
1108 put32(p+12, 0xe5bef008); /* ldr pc, [lr, #8]! */
1109 }
1110
1111 symattr->plt_offset = plt->data_offset;
1112 if (symattr->plt_thumb_stub) {
1113 p = section_ptr_add(plt, 20);
1114 put32(p, 0x4778); /* bx pc */
1115 put32(p+2, 0x46c0); /* nop */
1116 p += 4;
1117 } else
1118 p = section_ptr_add(plt, 16);
1119 put32(p, 0xe59fc004); /* ldr ip, [pc, #4] ; GOT entry offset */
1120 put32(p+4, 0xe08fc00c); /* add ip, pc, ip ; addr of GOT entry */
1121 put32(p+8, 0xe59cf000); /* ldr pc, [ip] ; jump to GOT entry */
1122 put32(p+12, s1->got->data_offset); /* GOT entry off once patched */
1123
1124 /* the symbol is modified so that it will be relocated to
1125 the PLT */
1126 if (sym->st_shndx == SHN_UNDEF)
1127 offset = plt->data_offset - 16;
1128 }
1129 #elif defined(TCC_TARGET_C67)
1130 if (s1->dynsym) {
1131 tcc_error("C67 got not implemented");
1132 }
1133 #else
1134 #error unsupported CPU
1135 #endif
1136 if (s1->dynsym) {
1137 /* XXX This might generate multiple syms for name. */
1138 index = put_elf_sym(s1->dynsym, offset,
1139 size, info, 0, sym->st_shndx, name);
1140 /* Create the relocation (it's against the GOT for PLT
1141 and GOT relocs). */
1142 put_elf_reloc(s1->dynsym, s1->got,
1143 s1->got->data_offset,
1144 reloc_type, index);
1145 } else {
1146 /* Without .dynsym (i.e. static link or memory output) we
1147 still need relocs against the generated got, so as to fill
1148 the entries with the symbol values (determined later). */
1149 put_elf_reloc(symtab_section, s1->got,
1150 s1->got->data_offset,
1151 reloc_type, sym_index);
1152 }
1153 /* And now create the GOT slot itself. */
1154 ptr = section_ptr_add(s1->got, PTR_SIZE);
1155 *ptr = 0;
1156 if (need_plt_entry)
1157 return symattr->plt_offset;
1158 else
1159 return symattr->got_offset;
1160 }
1161
1162 /* build GOT and PLT entries */
1163 ST_FUNC void build_got_entries(TCCState *s1)
1164 {
1165 Section *s;
1166 ElfW_Rel *rel;
1167 ElfW(Sym) *sym;
1168 int i, type, reloc_type, sym_index;
1169
1170 for(i = 1; i < s1->nb_sections; i++) {
1171 s = s1->sections[i];
1172 if (s->sh_type != SHT_RELX)
1173 continue;
1174 /* no need to handle got relocations */
1175 if (s->link != symtab_section)
1176 continue;
1177 for_each_elem(s, 0, rel, ElfW_Rel) {
1178 type = ELFW(R_TYPE)(rel->r_info);
1179 switch(type) {
1180 #if defined(TCC_TARGET_I386)
1181 case R_386_GOT32:
1182 case R_386_GOTOFF:
1183 case R_386_GOTPC:
1184 case R_386_PLT32:
1185 if (!s1->got)
1186 build_got(s1);
1187 if (type == R_386_GOT32 || type == R_386_PLT32) {
1188 sym_index = ELFW(R_SYM)(rel->r_info);
1189 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1190 /* look at the symbol got offset. If none, then add one */
1191 if (type == R_386_GOT32)
1192 reloc_type = R_386_GLOB_DAT;
1193 else
1194 reloc_type = R_386_JMP_SLOT;
1195 put_got_entry(s1, reloc_type, sym->st_size, sym->st_info,
1196 sym_index);
1197 }
1198 break;
1199 #elif defined(TCC_TARGET_ARM)
1200 case R_ARM_PC24:
1201 case R_ARM_CALL:
1202 case R_ARM_JUMP24:
1203 case R_ARM_GOT32:
1204 case R_ARM_GOTOFF:
1205 case R_ARM_GOTPC:
1206 case R_ARM_PLT32:
1207 if (!s1->got)
1208 build_got(s1);
1209 sym_index = ELFW(R_SYM)(rel->r_info);
1210 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1211 if (type != R_ARM_GOTOFF && type != R_ARM_GOTPC
1212 && sym->st_shndx == SHN_UNDEF) {
1213 unsigned long ofs;
1214 /* look at the symbol got offset. If none, then add one */
1215 if (type == R_ARM_GOT32)
1216 reloc_type = R_ARM_GLOB_DAT;
1217 else
1218 reloc_type = R_ARM_JUMP_SLOT;
1219 ofs = put_got_entry(s1, reloc_type, sym->st_size,
1220 sym->st_info, sym_index);
1221 #ifdef DEBUG_RELOC
1222 printf ("maybegot: %s, %d, %d --> ofs=0x%x\n",
1223 (char *) symtab_section->link->data + sym->st_name,
1224 type, sym->st_shndx, ofs);
1225 #endif
1226 if (type != R_ARM_GOT32) {
1227 addr_t *ptr = (addr_t*)(s1->sections[s->sh_info]->data
1228 + rel->r_offset);
1229 /* x must be signed! */
1230 int x = *ptr & 0xffffff;
1231 x = (x << 8) >> 8;
1232 x <<= 2;
1233 x += ofs;
1234 x >>= 2;
1235 #ifdef DEBUG_RELOC
1236 printf ("insn=0x%x --> 0x%x (x==0x%x)\n", *ptr,
1237 (*ptr & 0xff000000) | x, x);
1238 #endif
1239 *ptr = (*ptr & 0xff000000) | x;
1240 }
1241 }
1242 break;
1243 case R_ARM_THM_JUMP24:
1244 sym_index = ELFW(R_SYM)(rel->r_info);
1245 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1246 /* We are relocating a jump from thumb code to arm code */
1247 if (sym->st_shndx != SHN_UNDEF && !(sym->st_value & 1)) {
1248 int index;
1249 uint8_t *p;
1250 char *name, buf[1024];
1251 Section *text_section;
1252
1253 name = (char *) symtab_section->link->data + sym->st_name;
1254 text_section = s1->sections[sym->st_shndx];
1255 /* Modify reloc to target a thumb stub to switch to ARM */
1256 snprintf(buf, sizeof(buf), "%s_from_thumb", name);
1257 index = put_elf_sym(symtab_section,
1258 text_section->data_offset + 1,
1259 sym->st_size, sym->st_info, 0,
1260 sym->st_shndx, buf);
1261 rel->r_info = ELFW(R_INFO)(index, type);
1262 /* Create a thumb stub fonction to switch to ARM mode */
1263 put_elf_reloc(symtab_section, text_section,
1264 text_section->data_offset + 4, R_ARM_JUMP24,
1265 sym_index);
1266 p = section_ptr_add(text_section, 8);
1267 put32(p, 0x4778); /* bx pc */
1268 put32(p+2, 0x46c0); /* nop */
1269 put32(p+4, 0xeafffffe); /* b $sym */
1270 }
1271 #elif defined(TCC_TARGET_C67)
1272 case R_C60_GOT32:
1273 case R_C60_GOTOFF:
1274 case R_C60_GOTPC:
1275 case R_C60_PLT32:
1276 if (!s1->got)
1277 build_got(s1);
1278 if (type == R_C60_GOT32 || type == R_C60_PLT32) {
1279 sym_index = ELFW(R_SYM)(rel->r_info);
1280 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1281 /* look at the symbol got offset. If none, then add one */
1282 if (type == R_C60_GOT32)
1283 reloc_type = R_C60_GLOB_DAT;
1284 else
1285 reloc_type = R_C60_JMP_SLOT;
1286 put_got_entry(s1, reloc_type, sym->st_size, sym->st_info,
1287 sym_index);
1288 }
1289 break;
1290 #elif defined(TCC_TARGET_X86_64)
1291 case R_X86_64_GOT32:
1292 case R_X86_64_GOTTPOFF:
1293 case R_X86_64_GOTPCREL:
1294 case R_X86_64_PLT32:
1295 sym_index = ELFW(R_SYM)(rel->r_info);
1296 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1297 if (type == R_X86_64_PLT32 &&
1298 ELFW(ST_VISIBILITY)(sym->st_other) != STV_DEFAULT)
1299 {
1300 rel->r_info = ELFW(R_INFO)(sym_index, R_X86_64_PC32);
1301 break;
1302 }
1303
1304 if (!s1->got)
1305 build_got(s1);
1306 if (type == R_X86_64_GOT32 || type == R_X86_64_GOTPCREL ||
1307 type == R_X86_64_PLT32) {
1308 unsigned long ofs;
1309 /* look at the symbol got offset. If none, then add one */
1310 if (type == R_X86_64_GOT32 || type == R_X86_64_GOTPCREL)
1311 reloc_type = R_X86_64_GLOB_DAT;
1312 else
1313 reloc_type = R_X86_64_JUMP_SLOT;
1314 ofs = put_got_entry(s1, reloc_type, sym->st_size,
1315 sym->st_info, sym_index);
1316 if (type == R_X86_64_PLT32)
1317 /* We store the place of the generated PLT slot
1318 in our addend. */
1319 rel->r_addend += ofs;
1320 }
1321 break;
1322 #else
1323 #error unsupported CPU
1324 #endif
1325 default:
1326 break;
1327 }
1328 }
1329 }
1330 }
1331
1332 ST_FUNC Section *new_symtab(TCCState *s1,
1333 const char *symtab_name, int sh_type, int sh_flags,
1334 const char *strtab_name,
1335 const char *hash_name, int hash_sh_flags)
1336 {
1337 Section *symtab, *strtab, *hash;
1338 int *ptr, nb_buckets;
1339
1340 symtab = new_section(s1, symtab_name, sh_type, sh_flags);
1341 symtab->sh_entsize = sizeof(ElfW(Sym));
1342 strtab = new_section(s1, strtab_name, SHT_STRTAB, sh_flags);
1343 put_elf_str(strtab, "");
1344 symtab->link = strtab;
1345 put_elf_sym(symtab, 0, 0, 0, 0, 0, NULL);
1346
1347 nb_buckets = 1;
1348
1349 hash = new_section(s1, hash_name, SHT_HASH, hash_sh_flags);
1350 hash->sh_entsize = sizeof(int);
1351 symtab->hash = hash;
1352 hash->link = symtab;
1353
1354 ptr = section_ptr_add(hash, (2 + nb_buckets + 1) * sizeof(int));
1355 ptr[0] = nb_buckets;
1356 ptr[1] = 1;
1357 memset(ptr + 2, 0, (nb_buckets + 1) * sizeof(int));
1358 return symtab;
1359 }
1360
1361 /* put dynamic tag */
1362 static void put_dt(Section *dynamic, int dt, addr_t val)
1363 {
1364 ElfW(Dyn) *dyn;
1365 dyn = section_ptr_add(dynamic, sizeof(ElfW(Dyn)));
1366 dyn->d_tag = dt;
1367 dyn->d_un.d_val = val;
1368 }
1369
1370 static void add_init_array_defines(TCCState *s1, const char *section_name)
1371 {
1372 Section *s;
1373 long end_offset;
1374 char sym_start[1024];
1375 char sym_end[1024];
1376
1377 snprintf(sym_start, sizeof(sym_start), "__%s_start", section_name + 1);
1378 snprintf(sym_end, sizeof(sym_end), "__%s_end", section_name + 1);
1379
1380 s = find_section(s1, section_name);
1381 if (!s) {
1382 end_offset = 0;
1383 s = data_section;
1384 } else {
1385 end_offset = s->data_offset;
1386 }
1387
1388 add_elf_sym(symtab_section,
1389 0, 0,
1390 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1391 s->sh_num, sym_start);
1392 add_elf_sym(symtab_section,
1393 end_offset, 0,
1394 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1395 s->sh_num, sym_end);
1396 }
1397
1398 ST_FUNC void tcc_add_bcheck(TCCState *s1)
1399 {
1400 #ifdef CONFIG_TCC_BCHECK
1401 unsigned long *ptr;
1402 Section *init_section;
1403 unsigned char *pinit;
1404 int sym_index;
1405
1406 if (0 == s1->do_bounds_check)
1407 return;
1408
1409 /* XXX: add an object file to do that */
1410 ptr = section_ptr_add(bounds_section, sizeof(unsigned long));
1411 *ptr = 0;
1412 add_elf_sym(symtab_section, 0, 0,
1413 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1414 bounds_section->sh_num, "__bounds_start");
1415 #ifdef TCC_TARGET_I386
1416 if (s1->output_type != TCC_OUTPUT_MEMORY) {
1417 /* add 'call __bound_init()' in .init section */
1418 init_section = find_section(s1, ".init");
1419 pinit = section_ptr_add(init_section, 5);
1420 pinit[0] = 0xe8;
1421 put32(pinit + 1, -4);
1422 sym_index = find_elf_sym(symtab_section, "__bound_init");
1423 put_elf_reloc(symtab_section, init_section,
1424 init_section->data_offset - 4, R_386_PC32, sym_index);
1425 }
1426 #endif
1427 #endif
1428 }
1429
1430 static inline int tcc_add_support(TCCState *s1, const char *filename)
1431 {
1432 char buf[1024];
1433 snprintf(buf, sizeof(buf), "%s/%s", s1->tcc_lib_path, filename);
1434 return tcc_add_file(s1, buf);
1435 }
1436
1437 /* add tcc runtime libraries */
1438 ST_FUNC void tcc_add_runtime(TCCState *s1)
1439 {
1440 /* add libc */
1441 if (!s1->nostdlib) {
1442 tcc_add_library(s1, "c");
1443 #ifdef CONFIG_USE_LIBGCC
1444 if (!s1->static_link) {
1445 tcc_add_file(s1, TCC_LIBGCC);
1446 tcc_add_support(s1, "libtcc1.a");
1447 } else
1448 tcc_add_support(s1, "libtcc1.a");
1449 #else
1450 tcc_add_support(s1, "libtcc1.a");
1451 #endif
1452 }
1453
1454 /* tcc_add_bcheck tries to relocate a call to __bound_init in _init so
1455 libtcc1.a must be loaded before for __bound_init to be defined and
1456 crtn.o must be loaded after to not finalize _init too early. */
1457 tcc_add_bcheck(s1);
1458
1459 if (!s1->nostdlib) {
1460 /* add crt end if not memory output */
1461 if (s1->output_type != TCC_OUTPUT_MEMORY)
1462 tcc_add_crt(s1, "crtn.o");
1463 }
1464 }
1465
1466 /* add various standard linker symbols (must be done after the
1467 sections are filled (for example after allocating common
1468 symbols)) */
1469 ST_FUNC void tcc_add_linker_symbols(TCCState *s1)
1470 {
1471 char buf[1024];
1472 int i;
1473 Section *s;
1474
1475 add_elf_sym(symtab_section,
1476 text_section->data_offset, 0,
1477 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1478 text_section->sh_num, "_etext");
1479 add_elf_sym(symtab_section,
1480 data_section->data_offset, 0,
1481 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1482 data_section->sh_num, "_edata");
1483 add_elf_sym(symtab_section,
1484 bss_section->data_offset, 0,
1485 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1486 bss_section->sh_num, "_end");
1487 /* horrible new standard ldscript defines */
1488 add_init_array_defines(s1, ".preinit_array");
1489 add_init_array_defines(s1, ".init_array");
1490 add_init_array_defines(s1, ".fini_array");
1491
1492 /* add start and stop symbols for sections whose name can be
1493 expressed in C */
1494 for(i = 1; i < s1->nb_sections; i++) {
1495 s = s1->sections[i];
1496 if (s->sh_type == SHT_PROGBITS &&
1497 (s->sh_flags & SHF_ALLOC)) {
1498 const char *p;
1499 int ch;
1500
1501 /* check if section name can be expressed in C */
1502 p = s->name;
1503 for(;;) {
1504 ch = *p;
1505 if (!ch)
1506 break;
1507 if (!isid(ch) && !isnum(ch))
1508 goto next_sec;
1509 p++;
1510 }
1511 snprintf(buf, sizeof(buf), "__start_%s", s->name);
1512 add_elf_sym(symtab_section,
1513 0, 0,
1514 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1515 s->sh_num, buf);
1516 snprintf(buf, sizeof(buf), "__stop_%s", s->name);
1517 add_elf_sym(symtab_section,
1518 s->data_offset, 0,
1519 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1520 s->sh_num, buf);
1521 }
1522 next_sec: ;
1523 }
1524 }
1525
1526 static void tcc_output_binary(TCCState *s1, FILE *f,
1527 const int *sec_order)
1528 {
1529 Section *s;
1530 int i, offset, size;
1531
1532 offset = 0;
1533 for(i=1;i<s1->nb_sections;i++) {
1534 s = s1->sections[sec_order[i]];
1535 if (s->sh_type != SHT_NOBITS &&
1536 (s->sh_flags & SHF_ALLOC)) {
1537 while (offset < s->sh_offset) {
1538 fputc(0, f);
1539 offset++;
1540 }
1541 size = s->sh_size;
1542 fwrite(s->data, 1, size, f);
1543 offset += size;
1544 }
1545 }
1546 }
1547
1548 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1549 #define HAVE_PHDR 1
1550 #define EXTRA_RELITEMS 14
1551
1552 /* move the relocation value from .dynsym to .got */
1553 void patch_dynsym_undef(TCCState *s1, Section *s)
1554 {
1555 uint32_t *gotd = (void *)s1->got->data;
1556 ElfW(Sym) *sym;
1557
1558 gotd += 3; /* dummy entries in .got */
1559 /* relocate symbols in .dynsym */
1560 for_each_elem(s, 1, sym, ElfW(Sym)) {
1561 if (sym->st_shndx == SHN_UNDEF) {
1562 *gotd++ = sym->st_value + 6; /* XXX 6 is magic ? */
1563 sym->st_value = 0;
1564 }
1565 }
1566 }
1567 #else
1568 #define HAVE_PHDR 1
1569 #define EXTRA_RELITEMS 9
1570
1571 /* zero plt offsets of weak symbols in .dynsym */
1572 void patch_dynsym_undef(TCCState *s1, Section *s)
1573 {
1574 ElfW(Sym) *sym;
1575
1576 for_each_elem(s, 1, sym, ElfW(Sym))
1577 if (sym->st_shndx == SHN_UNDEF && ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
1578 sym->st_value = 0;
1579 }
1580 #endif
1581
1582 ST_FUNC void fill_got_entry(TCCState *s1, ElfW_Rel *rel)
1583 {
1584 int sym_index = ELFW(R_SYM) (rel->r_info);
1585 ElfW(Sym) *sym = &((ElfW(Sym) *) symtab_section->data)[sym_index];
1586 unsigned long offset;
1587
1588 if (sym_index >= s1->nb_sym_attrs)
1589 return;
1590 offset = s1->sym_attrs[sym_index].got_offset;
1591 section_reserve(s1->got, offset + PTR_SIZE);
1592 #ifdef TCC_TARGET_X86_64
1593 /* only works for x86-64 */
1594 put32(s1->got->data + offset + 4, sym->st_value >> 32);
1595 #endif
1596 put32(s1->got->data + offset, sym->st_value & 0xffffffff);
1597 }
1598
1599 /* Perform relocation to GOT or PLT entries */
1600 ST_FUNC void fill_got(TCCState *s1)
1601 {
1602 Section *s;
1603 ElfW_Rel *rel;
1604 int i;
1605
1606 for(i = 1; i < s1->nb_sections; i++) {
1607 s = s1->sections[i];
1608 if (s->sh_type != SHT_RELX)
1609 continue;
1610 /* no need to handle got relocations */
1611 if (s->link != symtab_section)
1612 continue;
1613 for_each_elem(s, 0, rel, ElfW_Rel) {
1614 switch (ELFW(R_TYPE) (rel->r_info)) {
1615 case R_X86_64_GOT32:
1616 case R_X86_64_GOTPCREL:
1617 case R_X86_64_PLT32:
1618 fill_got_entry(s1, rel);
1619 break;
1620 }
1621 }
1622 }
1623 }
1624
1625 /* Bind symbols of executable: resolve undefined symbols from exported symbols
1626 in shared libraries and export non local defined symbols to shared libraries
1627 if -rdynamic switch was given on command line */
1628 static void bind_exe_dynsyms(TCCState *s1)
1629 {
1630 const char *name;
1631 int sym_index, index;
1632 ElfW(Sym) *sym, *esym;
1633 int type;
1634
1635 /* Resolve undefined symbols from dynamic symbols. When there is a match:
1636 - if STT_FUNC or STT_GNU_IFUNC symbol -> add it in PLT
1637 - if STT_OBJECT symbol -> add it in .bss section with suitable reloc */
1638 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
1639 if (sym->st_shndx == SHN_UNDEF) {
1640 name = (char *) symtab_section->link->data + sym->st_name;
1641 sym_index = find_elf_sym(s1->dynsymtab_section, name);
1642 if (sym_index) {
1643 esym = &((ElfW(Sym) *)s1->dynsymtab_section->data)[sym_index];
1644 type = ELFW(ST_TYPE)(esym->st_info);
1645 if ((type == STT_FUNC) || (type == STT_GNU_IFUNC)) {
1646 /* Indirect functions shall have STT_FUNC type in executable
1647 * dynsym section. Indeed, a dlsym call following a lazy
1648 * resolution would pick the symbol value from the
1649 * executable dynsym entry which would contain the address
1650 * of the function wanted by the caller of dlsym instead of
1651 * the address of the function that would return that
1652 * address */
1653 put_got_entry(s1, R_JMP_SLOT, esym->st_size,
1654 ELFW(ST_INFO)(STB_GLOBAL,STT_FUNC),
1655 sym - (ElfW(Sym) *)symtab_section->data);
1656 } else if (type == STT_OBJECT) {
1657 unsigned long offset;
1658 ElfW(Sym) *dynsym;
1659 offset = bss_section->data_offset;
1660 /* XXX: which alignment ? */
1661 offset = (offset + 16 - 1) & -16;
1662 index = put_elf_sym(s1->dynsym, offset, esym->st_size,
1663 esym->st_info, 0, bss_section->sh_num,
1664 name);
1665 /* Ensure R_COPY works for weak symbol aliases */
1666 if (ELFW(ST_BIND)(esym->st_info) == STB_WEAK) {
1667 for_each_elem(s1->dynsymtab_section, 1, dynsym, ElfW(Sym)) {
1668 if ((dynsym->st_value == esym->st_value)
1669 && (ELFW(ST_BIND)(dynsym->st_info) == STB_GLOBAL)) {
1670 char *dynname = (char *) s1->dynsymtab_section->link->data
1671 + dynsym->st_name;
1672 put_elf_sym(s1->dynsym, offset, dynsym->st_size,
1673 dynsym->st_info, 0,
1674 bss_section->sh_num, dynname);
1675 break;
1676 }
1677 }
1678 }
1679 put_elf_reloc(s1->dynsym, bss_section,
1680 offset, R_COPY, index);
1681 offset += esym->st_size;
1682 bss_section->data_offset = offset;
1683 }
1684 } else {
1685 /* STB_WEAK undefined symbols are accepted */
1686 /* XXX: _fp_hw seems to be part of the ABI, so we ignore it */
1687 if (ELFW(ST_BIND)(sym->st_info) == STB_WEAK ||
1688 !strcmp(name, "_fp_hw")) {
1689 } else {
1690 tcc_error_noabort("undefined symbol '%s'", name);
1691 }
1692 }
1693 } else if (s1->rdynamic && ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
1694 /* if -rdynamic option, then export all non local symbols */
1695 name = (char *) symtab_section->link->data + sym->st_name;
1696 put_elf_sym(s1->dynsym, sym->st_value, sym->st_size, sym->st_info,
1697 0, sym->st_shndx, name);
1698 }
1699 }
1700 }
1701
1702 /* Bind symbols of libraries: export non local symbols of executable that
1703 resolve undefined symbols of shared libraries */
1704 static void bind_libs_dynsyms(TCCState *s1)
1705 {
1706 const char *name;
1707 int sym_index;
1708 ElfW(Sym) *sym, *esym;
1709
1710 /* now look at unresolved dynamic symbols and export
1711 corresponding symbol */
1712 for_each_elem(s1->dynsymtab_section, 1, esym, ElfW(Sym)) {
1713 if (esym->st_shndx == SHN_UNDEF) {
1714 name = (char *) s1->dynsymtab_section->link->data + esym->st_name;
1715 sym_index = find_elf_sym(symtab_section, name);
1716 if (sym_index) {
1717 /* XXX: avoid adding a symbol if already present because of
1718 -rdynamic ? */
1719 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1720 put_elf_sym(s1->dynsym, sym->st_value, sym->st_size,
1721 sym->st_info, 0, sym->st_shndx, name);
1722 } else {
1723 /* weak symbols can stay undefined */
1724 if (ELFW(ST_BIND)(esym->st_info) != STB_WEAK)
1725 tcc_warning("undefined dynamic symbol '%s'", name);
1726 }
1727 }
1728 }
1729 }
1730
1731 /* Export all non local symbols (for shared libraries) */
1732 static void export_global_syms(TCCState *s1)
1733 {
1734 int nb_syms, dynindex, index;
1735 const char *name;
1736 ElfW(Sym) *sym;
1737
1738 nb_syms = symtab_section->data_offset / sizeof(ElfW(Sym));
1739 s1->symtab_to_dynsym = tcc_mallocz(sizeof(int) * nb_syms);
1740 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
1741 if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
1742 name = (char *) symtab_section->link->data + sym->st_name;
1743 dynindex = put_elf_sym(s1->dynsym, sym->st_value, sym->st_size,
1744 sym->st_info, 0, sym->st_shndx, name);
1745 index = sym - (ElfW(Sym) *) symtab_section->data;
1746 s1->symtab_to_dynsym[index] = dynindex;
1747 }
1748 }
1749 }
1750
1751 /* relocate the PLT: compute addresses and offsets in the PLT now that final
1752 address for PLT and GOT are known (see fill_program_header) */
1753 ST_FUNC void relocate_plt(TCCState *s1)
1754 {
1755 uint8_t *p, *p_end;
1756
1757 if (!s1->plt)
1758 return;
1759
1760 p = s1->plt->data;
1761 p_end = p + s1->plt->data_offset;
1762 if (p < p_end) {
1763 #if defined(TCC_TARGET_I386)
1764 put32(p + 2, get32(p + 2) + s1->got->sh_addr);
1765 put32(p + 8, get32(p + 8) + s1->got->sh_addr);
1766 p += 16;
1767 while (p < p_end) {
1768 put32(p + 2, get32(p + 2) + s1->got->sh_addr);
1769 p += 16;
1770 }
1771 #elif defined(TCC_TARGET_X86_64)
1772 int x = s1->got->sh_addr - s1->plt->sh_addr - 6;
1773 put32(p + 2, get32(p + 2) + x);
1774 put32(p + 8, get32(p + 8) + x - 6);
1775 p += 16;
1776 while (p < p_end) {
1777 put32(p + 2, get32(p + 2) + x + s1->plt->data - p);
1778 p += 16;
1779 }
1780 #elif defined(TCC_TARGET_ARM)
1781 int x;
1782 x=s1->got->sh_addr - s1->plt->sh_addr - 12;
1783 p += 16;
1784 while (p < p_end) {
1785 if (get32(p) == 0x46c04778) /* PLT Thumb stub present */
1786 p += 4;
1787 put32(p + 12, x + get32(p + 12) + s1->plt->data - p);
1788 p += 16;
1789 }
1790 #elif defined(TCC_TARGET_C67)
1791 /* XXX: TODO */
1792 #else
1793 #error unsupported CPU
1794 #endif
1795 }
1796 }
1797
1798 /* Allocate strings for section names and decide if an unallocated section
1799 should be output.
1800
1801 NOTE: the strsec section comes last, so its size is also correct ! */
1802 static void alloc_sec_names(TCCState *s1, int file_type, Section *strsec)
1803 {
1804 int i;
1805 Section *s;
1806
1807 /* Allocate strings for section names */
1808 for(i = 1; i < s1->nb_sections; i++) {
1809 s = s1->sections[i];
1810 s->sh_name = put_elf_str(strsec, s->name);
1811 /* when generating a DLL, we include relocations but we may
1812 patch them */
1813 if (file_type == TCC_OUTPUT_DLL &&
1814 s->sh_type == SHT_RELX &&
1815 !(s->sh_flags & SHF_ALLOC)) {
1816 /* gr: avoid bogus relocs for empty (debug) sections */
1817 if (s1->sections[s->sh_info]->sh_flags & SHF_ALLOC)
1818 prepare_dynamic_rel(s1, s);
1819 else if (s1->do_debug)
1820 s->sh_size = s->data_offset;
1821 } else if (s1->do_debug ||
1822 file_type == TCC_OUTPUT_OBJ ||
1823 (s->sh_flags & SHF_ALLOC) ||
1824 i == (s1->nb_sections - 1)) {
1825 /* we output all sections if debug or object file */
1826 s->sh_size = s->data_offset;
1827 }
1828 }
1829 }
1830
1831 /* Info to be copied in dynamic section */
1832 struct dyn_inf {
1833 Section *dynamic;
1834 Section *dynstr;
1835 unsigned long dyn_rel_off;
1836 addr_t rel_addr;
1837 addr_t rel_size;
1838 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1839 addr_t bss_addr;
1840 addr_t bss_size;
1841 #endif
1842 };
1843
1844 /* Assign sections to segments and decide how are sections laid out when loaded
1845 in memory. This function also fills corresponding program headers. */
1846 static int layout_sections(TCCState *s1, ElfW(Phdr) *phdr, int phnum,
1847 Section *interp, Section* strsec,
1848 struct dyn_inf *dyninf, int *sec_order)
1849 {
1850 int i, j, k, file_type, sh_order_index, file_offset;
1851 unsigned long s_align;
1852 long long tmp;
1853 addr_t addr;
1854 ElfW(Phdr) *ph;
1855 Section *s;
1856
1857 file_type = s1->output_type;
1858 sh_order_index = 1;
1859 file_offset = 0;
1860 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF)
1861 file_offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr));
1862 s_align = ELF_PAGE_SIZE;
1863 if (s1->section_align)
1864 s_align = s1->section_align;
1865
1866 if (phnum > 0) {
1867 if (s1->has_text_addr) {
1868 int a_offset, p_offset;
1869 addr = s1->text_addr;
1870 /* we ensure that (addr % ELF_PAGE_SIZE) == file_offset %
1871 ELF_PAGE_SIZE */
1872 a_offset = (int) (addr & (s_align - 1));
1873 p_offset = file_offset & (s_align - 1);
1874 if (a_offset < p_offset)
1875 a_offset += s_align;
1876 file_offset += (a_offset - p_offset);
1877 } else {
1878 if (file_type == TCC_OUTPUT_DLL)
1879 addr = 0;
1880 else
1881 addr = ELF_START_ADDR;
1882 /* compute address after headers */
1883 addr += (file_offset & (s_align - 1));
1884 }
1885
1886 ph = &phdr[0];
1887 /* Leave one program headers for the program interpreter and one for
1888 the program header table itself if needed. These are done later as
1889 they require section layout to be done first. */
1890 if (interp)
1891 ph += 1 + HAVE_PHDR;
1892
1893 /* dynamic relocation table information, for .dynamic section */
1894 dyninf->rel_addr = dyninf->rel_size = 0;
1895 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1896 dyninf->bss_addr = dyninf->bss_size = 0;
1897 #endif
1898
1899 for(j = 0; j < 2; j++) {
1900 ph->p_type = PT_LOAD;
1901 if (j == 0)
1902 ph->p_flags = PF_R | PF_X;
1903 else
1904 ph->p_flags = PF_R | PF_W;
1905 ph->p_align = s_align;
1906
1907 /* Decide the layout of sections loaded in memory. This must
1908 be done before program headers are filled since they contain
1909 info about the layout. We do the following ordering: interp,
1910 symbol tables, relocations, progbits, nobits */
1911 /* XXX: do faster and simpler sorting */
1912 for(k = 0; k < 5; k++) {
1913 for(i = 1; i < s1->nb_sections; i++) {
1914 s = s1->sections[i];
1915 /* compute if section should be included */
1916 if (j == 0) {
1917 if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) !=
1918 SHF_ALLOC)
1919 continue;
1920 } else {
1921 if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) !=
1922 (SHF_ALLOC | SHF_WRITE))
1923 continue;
1924 }
1925 if (s == interp) {
1926 if (k != 0)
1927 continue;
1928 } else if (s->sh_type == SHT_DYNSYM ||
1929 s->sh_type == SHT_STRTAB ||
1930 s->sh_type == SHT_HASH) {
1931 if (k != 1)
1932 continue;
1933 } else if (s->sh_type == SHT_RELX) {
1934 if (k != 2)
1935 continue;
1936 } else if (s->sh_type == SHT_NOBITS) {
1937 if (k != 4)
1938 continue;
1939 } else {
1940 if (k != 3)
1941 continue;
1942 }
1943 sec_order[sh_order_index++] = i;
1944
1945 /* section matches: we align it and add its size */
1946 tmp = addr;
1947 addr = (addr + s->sh_addralign - 1) &
1948 ~(s->sh_addralign - 1);
1949 file_offset += (int) ( addr - tmp );
1950 s->sh_offset = file_offset;
1951 s->sh_addr = addr;
1952
1953 /* update program header infos */
1954 if (ph->p_offset == 0) {
1955 ph->p_offset = file_offset;
1956 ph->p_vaddr = addr;
1957 ph->p_paddr = ph->p_vaddr;
1958 }
1959 /* update dynamic relocation infos */
1960 if (s->sh_type == SHT_RELX) {
1961 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1962 if (!strcmp(strsec->data + s->sh_name, ".rel.got")) {
1963 dyninf->rel_addr = addr;
1964 dyninf->rel_size += s->sh_size; /* XXX only first rel. */
1965 }
1966 if (!strcmp(strsec->data + s->sh_name, ".rel.bss")) {
1967 dyninf->bss_addr = addr;
1968 dyninf->bss_size = s->sh_size; /* XXX only first rel. */
1969 }
1970 #else
1971 if (dyninf->rel_size == 0)
1972 dyninf->rel_addr = addr;
1973 dyninf->rel_size += s->sh_size;
1974 #endif
1975 }
1976 addr += s->sh_size;
1977 if (s->sh_type != SHT_NOBITS)
1978 file_offset += s->sh_size;
1979 }
1980 }
1981 if (j == 0) {
1982 /* Make the first PT_LOAD segment include the program
1983 headers itself (and the ELF header as well), it'll
1984 come out with same memory use but will make various
1985 tools like binutils strip work better. */
1986 ph->p_offset &= ~(ph->p_align - 1);
1987 ph->p_vaddr &= ~(ph->p_align - 1);
1988 ph->p_paddr &= ~(ph->p_align - 1);
1989 }
1990 ph->p_filesz = file_offset - ph->p_offset;
1991 ph->p_memsz = addr - ph->p_vaddr;
1992 ph++;
1993 if (j == 0) {
1994 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF) {
1995 /* if in the middle of a page, we duplicate the page in
1996 memory so that one copy is RX and the other is RW */
1997 if ((addr & (s_align - 1)) != 0)
1998 addr += s_align;
1999 } else {
2000 addr = (addr + s_align - 1) & ~(s_align - 1);
2001 file_offset = (file_offset + s_align - 1) & ~(s_align - 1);
2002 }
2003 }
2004 }
2005 }
2006
2007 /* all other sections come after */
2008 for(i = 1; i < s1->nb_sections; i++) {
2009 s = s1->sections[i];
2010 if (phnum > 0 && (s->sh_flags & SHF_ALLOC))
2011 continue;
2012 sec_order[sh_order_index++] = i;
2013
2014 file_offset = (file_offset + s->sh_addralign - 1) &
2015 ~(s->sh_addralign - 1);
2016 s->sh_offset = file_offset;
2017 if (s->sh_type != SHT_NOBITS)
2018 file_offset += s->sh_size;
2019 }
2020
2021 return file_offset;
2022 }
2023
2024 static void fill_unloadable_phdr(ElfW(Phdr) *phdr, int phnum, Section *interp,
2025 Section *dynamic)
2026 {
2027 ElfW(Phdr) *ph;
2028
2029 /* if interpreter, then add corresponding program header */
2030 if (interp) {
2031 ph = &phdr[0];
2032
2033 if (HAVE_PHDR)
2034 {
2035 int len = phnum * sizeof(ElfW(Phdr));
2036
2037 ph->p_type = PT_PHDR;
2038 ph->p_offset = sizeof(ElfW(Ehdr));
2039 ph->p_vaddr = interp->sh_addr - len;
2040 ph->p_paddr = ph->p_vaddr;
2041 ph->p_filesz = ph->p_memsz = len;
2042 ph->p_flags = PF_R | PF_X;
2043 ph->p_align = 4; /* interp->sh_addralign; */
2044 ph++;
2045 }
2046
2047 ph->p_type = PT_INTERP;
2048 ph->p_offset = interp->sh_offset;
2049 ph->p_vaddr = interp->sh_addr;
2050 ph->p_paddr = ph->p_vaddr;
2051 ph->p_filesz = interp->sh_size;
2052 ph->p_memsz = interp->sh_size;
2053 ph->p_flags = PF_R;
2054 ph->p_align = interp->sh_addralign;
2055 }
2056
2057 /* if dynamic section, then add corresponding program header */
2058 if (dynamic) {
2059 ph = &phdr[phnum - 1];
2060
2061 ph->p_type = PT_DYNAMIC;
2062 ph->p_offset = dynamic->sh_offset;
2063 ph->p_vaddr = dynamic->sh_addr;
2064 ph->p_paddr = ph->p_vaddr;
2065 ph->p_filesz = dynamic->sh_size;
2066 ph->p_memsz = dynamic->sh_size;
2067 ph->p_flags = PF_R | PF_W;
2068 ph->p_align = dynamic->sh_addralign;
2069 }
2070 }
2071
2072 /* Fill the dynamic section with tags describing the address and size of
2073 sections */
2074 static void fill_dynamic(TCCState *s1, struct dyn_inf *dyninf)
2075 {
2076 Section *dynamic;
2077
2078 dynamic = dyninf->dynamic;
2079
2080 /* put dynamic section entries */
2081 dynamic->data_offset = dyninf->dyn_rel_off;
2082 put_dt(dynamic, DT_HASH, s1->dynsym->hash->sh_addr);
2083 put_dt(dynamic, DT_STRTAB, dyninf->dynstr->sh_addr);
2084 put_dt(dynamic, DT_SYMTAB, s1->dynsym->sh_addr);
2085 put_dt(dynamic, DT_STRSZ, dyninf->dynstr->data_offset);
2086 put_dt(dynamic, DT_SYMENT, sizeof(ElfW(Sym)));
2087 #ifdef TCC_TARGET_X86_64
2088 put_dt(dynamic, DT_RELA, dyninf->rel_addr);
2089 put_dt(dynamic, DT_RELASZ, dyninf->rel_size);
2090 put_dt(dynamic, DT_RELAENT, sizeof(ElfW_Rel));
2091 #else
2092 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2093 put_dt(dynamic, DT_PLTGOT, s1->got->sh_addr);
2094 put_dt(dynamic, DT_PLTRELSZ, dyninf->rel_size);
2095 put_dt(dynamic, DT_JMPREL, dyninf->rel_addr);
2096 put_dt(dynamic, DT_PLTREL, DT_REL);
2097 put_dt(dynamic, DT_REL, dyninf->bss_addr);
2098 put_dt(dynamic, DT_RELSZ, dyninf->bss_size);
2099 #else
2100 put_dt(dynamic, DT_REL, dyninf->rel_addr);
2101 put_dt(dynamic, DT_RELSZ, dyninf->rel_size);
2102 put_dt(dynamic, DT_RELENT, sizeof(ElfW_Rel));
2103 #endif
2104 #endif
2105 if (s1->do_debug)
2106 put_dt(dynamic, DT_DEBUG, 0);
2107 put_dt(dynamic, DT_NULL, 0);
2108 }
2109
2110 /* Relocate remaining sections and symbols (that is those not related to
2111 dynamic linking) */
2112 static int final_sections_reloc(TCCState *s1)
2113 {
2114 int i;
2115 Section *s;
2116
2117 relocate_syms(s1, 0);
2118
2119 if (s1->nb_errors != 0)
2120 return -1;
2121
2122 /* relocate sections */
2123 /* XXX: ignore sections with allocated relocations ? */
2124 for(i = 1; i < s1->nb_sections; i++) {
2125 s = s1->sections[i];
2126 if (s->reloc && s != s1->got)
2127 relocate_section(s1, s);
2128 }
2129
2130 /* relocate relocation entries if the relocation tables are
2131 allocated in the executable */
2132 for(i = 1; i < s1->nb_sections; i++) {
2133 s = s1->sections[i];
2134 if ((s->sh_flags & SHF_ALLOC) &&
2135 s->sh_type == SHT_RELX) {
2136 relocate_rel(s1, s);
2137 }
2138 }
2139 return 0;
2140 }
2141
2142 /* Create an ELF file on disk.
2143 This function handle ELF specific layout requirements */
2144 static void tcc_output_elf(TCCState *s1, FILE *f, int phnum, ElfW(Phdr) *phdr,
2145 int file_offset, int *sec_order)
2146 {
2147 int i, shnum, offset, size, file_type;
2148 Section *s;
2149 ElfW(Ehdr) ehdr;
2150 ElfW(Shdr) shdr, *sh;
2151
2152 file_type = s1->output_type;
2153 shnum = s1->nb_sections;
2154
2155 memset(&ehdr, 0, sizeof(ehdr));
2156
2157 if (phnum > 0) {
2158 ehdr.e_phentsize = sizeof(ElfW(Phdr));
2159 ehdr.e_phnum = phnum;
2160 ehdr.e_phoff = sizeof(ElfW(Ehdr));
2161 }
2162
2163 /* align to 4 */
2164 file_offset = (file_offset + 3) & -4;
2165
2166 /* fill header */
2167 ehdr.e_ident[0] = ELFMAG0;
2168 ehdr.e_ident[1] = ELFMAG1;
2169 ehdr.e_ident[2] = ELFMAG2;
2170 ehdr.e_ident[3] = ELFMAG3;
2171 ehdr.e_ident[4] = ELFCLASSW;
2172 ehdr.e_ident[5] = ELFDATA2LSB;
2173 ehdr.e_ident[6] = EV_CURRENT;
2174 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2175 ehdr.e_ident[EI_OSABI] = ELFOSABI_FREEBSD;
2176 #endif
2177 #ifdef TCC_TARGET_ARM
2178 #ifdef TCC_ARM_EABI
2179 ehdr.e_ident[EI_OSABI] = 0;
2180 ehdr.e_flags = EF_ARM_EABI_VER4;
2181 if (file_type == TCC_OUTPUT_EXE || file_type == TCC_OUTPUT_DLL)
2182 ehdr.e_flags |= EF_ARM_HASENTRY;
2183 if (s1->float_abi == ARM_HARD_FLOAT)
2184 ehdr.e_flags |= EF_ARM_VFP_FLOAT;
2185 else
2186 ehdr.e_flags |= EF_ARM_SOFT_FLOAT;
2187 #else
2188 ehdr.e_ident[EI_OSABI] = ELFOSABI_ARM;
2189 #endif
2190 #endif
2191 switch(file_type) {
2192 default:
2193 case TCC_OUTPUT_EXE:
2194 ehdr.e_type = ET_EXEC;
2195 ehdr.e_entry = get_elf_sym_addr(s1, "_start", 1);
2196 break;
2197 case TCC_OUTPUT_DLL:
2198 ehdr.e_type = ET_DYN;
2199 ehdr.e_entry = text_section->sh_addr; /* XXX: is it correct ? */
2200 break;
2201 case TCC_OUTPUT_OBJ:
2202 ehdr.e_type = ET_REL;
2203 break;
2204 }
2205 ehdr.e_machine = EM_TCC_TARGET;
2206 ehdr.e_version = EV_CURRENT;
2207 ehdr.e_shoff = file_offset;
2208 ehdr.e_ehsize = sizeof(ElfW(Ehdr));
2209 ehdr.e_shentsize = sizeof(ElfW(Shdr));
2210 ehdr.e_shnum = shnum;
2211 ehdr.e_shstrndx = shnum - 1;
2212
2213 fwrite(&ehdr, 1, sizeof(ElfW(Ehdr)), f);
2214 fwrite(phdr, 1, phnum * sizeof(ElfW(Phdr)), f);
2215 offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr));
2216
2217 sort_syms(s1, symtab_section);
2218 for(i = 1; i < s1->nb_sections; i++) {
2219 s = s1->sections[sec_order[i]];
2220 if (s->sh_type != SHT_NOBITS) {
2221 if (s->sh_type == SHT_DYNSYM)
2222 patch_dynsym_undef(s1, s);
2223 while (offset < s->sh_offset) {
2224 fputc(0, f);
2225 offset++;
2226 }
2227 size = s->sh_size;
2228 fwrite(s->data, 1, size, f);
2229 offset += size;
2230 }
2231 }
2232
2233 /* output section headers */
2234 while (offset < ehdr.e_shoff) {
2235 fputc(0, f);
2236 offset++;
2237 }
2238
2239 for(i = 0; i < s1->nb_sections; i++) {
2240 sh = &shdr;
2241 memset(sh, 0, sizeof(ElfW(Shdr)));
2242 s = s1->sections[i];
2243 if (s) {
2244 sh->sh_name = s->sh_name;
2245 sh->sh_type = s->sh_type;
2246 sh->sh_flags = s->sh_flags;
2247 sh->sh_entsize = s->sh_entsize;
2248 sh->sh_info = s->sh_info;
2249 if (s->link)
2250 sh->sh_link = s->link->sh_num;
2251 sh->sh_addralign = s->sh_addralign;
2252 sh->sh_addr = s->sh_addr;
2253 sh->sh_offset = s->sh_offset;
2254 sh->sh_size = s->sh_size;
2255 }
2256 fwrite(sh, 1, sizeof(ElfW(Shdr)), f);
2257 }
2258 }
2259
2260 /* Write an elf, coff or "binary" file */
2261 static int tcc_write_elf_file(TCCState *s1, const char *filename, int phnum,
2262 ElfW(Phdr) *phdr, int file_offset, int *sec_order)
2263 {
2264 int fd, mode, file_type;
2265 FILE *f;
2266
2267 file_type = s1->output_type;
2268 if (file_type == TCC_OUTPUT_OBJ)
2269 mode = 0666;
2270 else
2271 mode = 0777;
2272 unlink(filename);
2273 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, mode);
2274 if (fd < 0) {
2275 tcc_error_noabort("could not write '%s'", filename);
2276 return -1;
2277 }
2278 f = fdopen(fd, "wb");
2279 if (s1->verbose)
2280 printf("<- %s\n", filename);
2281
2282 #ifdef TCC_TARGET_COFF
2283 if (s1->output_format == TCC_OUTPUT_FORMAT_COFF)
2284 tcc_output_coff(s1, f);
2285 else
2286 #endif
2287 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF)
2288 tcc_output_elf(s1, f, phnum, phdr, file_offset, sec_order);
2289 else
2290 tcc_output_binary(s1, f, sec_order);
2291 fclose(f);
2292
2293 return 0;
2294 }
2295
2296 /* Output an elf, coff or binary file */
2297 /* XXX: suppress unneeded sections */
2298 static int elf_output_file(TCCState *s1, const char *filename)
2299 {
2300 int i, ret, phnum, shnum, file_type, file_offset, *sec_order;
2301 struct dyn_inf dyninf;
2302 ElfW(Phdr) *phdr;
2303 ElfW(Sym) *sym;
2304 Section *strsec, *interp, *dynamic, *dynstr;
2305
2306 file_type = s1->output_type;
2307 s1->nb_errors = 0;
2308
2309 /* if linking, also link in runtime libraries (libc, libgcc, etc.) */
2310 if (file_type != TCC_OUTPUT_OBJ) {
2311 tcc_add_runtime(s1);
2312 }
2313
2314 phdr = NULL;
2315 sec_order = NULL;
2316 interp = dynamic = dynstr = NULL; /* avoid warning */
2317 dyninf.dyn_rel_off = 0; /* avoid warning */
2318
2319 if (file_type != TCC_OUTPUT_OBJ) {
2320 relocate_common_syms();
2321
2322 tcc_add_linker_symbols(s1);
2323
2324 if (!s1->static_link) {
2325 if (file_type == TCC_OUTPUT_EXE) {
2326 char *ptr;
2327 /* allow override the dynamic loader */
2328 const char *elfint = getenv("LD_SO");
2329 if (elfint == NULL)
2330 elfint = DEFAULT_ELFINTERP(s1);
2331 /* add interpreter section only if executable */
2332 interp = new_section(s1, ".interp", SHT_PROGBITS, SHF_ALLOC);
2333 interp->sh_addralign = 1;
2334 ptr = section_ptr_add(interp, 1 + strlen(elfint));
2335 strcpy(ptr, elfint);
2336 }
2337
2338 /* add dynamic symbol table */
2339 s1->dynsym = new_symtab(s1, ".dynsym", SHT_DYNSYM, SHF_ALLOC,
2340 ".dynstr",
2341 ".hash", SHF_ALLOC);
2342 dynstr = s1->dynsym->link;
2343
2344 /* add dynamic section */
2345 dynamic = new_section(s1, ".dynamic", SHT_DYNAMIC,
2346 SHF_ALLOC | SHF_WRITE);
2347 dynamic->link = dynstr;
2348 dynamic->sh_entsize = sizeof(ElfW(Dyn));
2349
2350 build_got(s1);
2351
2352 if (file_type == TCC_OUTPUT_EXE) {
2353 bind_exe_dynsyms(s1);
2354
2355 if (s1->nb_errors) {
2356 ret = -1;
2357 goto the_end;
2358 }
2359
2360 bind_libs_dynsyms(s1);
2361 } else /* shared library case: simply export all global symbols */
2362 export_global_syms(s1);
2363
2364 build_got_entries(s1);
2365
2366 /* add a list of needed dlls */
2367 for(i = 0; i < s1->nb_loaded_dlls; i++) {
2368 DLLReference *dllref = s1->loaded_dlls[i];
2369 if (dllref->level == 0)
2370 put_dt(dynamic, DT_NEEDED, put_elf_str(dynstr, dllref->name));
2371 }
2372
2373 if (s1->rpath)
2374 put_dt(dynamic, DT_RPATH, put_elf_str(dynstr, s1->rpath));
2375
2376 /* XXX: currently, since we do not handle PIC code, we
2377 must relocate the readonly segments */
2378 if (file_type == TCC_OUTPUT_DLL) {
2379 if (s1->soname)
2380 put_dt(dynamic, DT_SONAME, put_elf_str(dynstr, s1->soname));
2381 put_dt(dynamic, DT_TEXTREL, 0);
2382 }
2383
2384 if (s1->symbolic)
2385 put_dt(dynamic, DT_SYMBOLIC, 0);
2386
2387 /* add necessary space for other entries */
2388 dyninf.dyn_rel_off = dynamic->data_offset;
2389 dynamic->data_offset += sizeof(ElfW(Dyn)) * EXTRA_RELITEMS;
2390 } else {
2391 /* still need to build got entries in case of static link */
2392 build_got_entries(s1);
2393 }
2394 }
2395
2396 /* we add a section for symbols */
2397 strsec = new_section(s1, ".shstrtab", SHT_STRTAB, 0);
2398 put_elf_str(strsec, "");
2399
2400 /* compute number of sections */
2401 shnum = s1->nb_sections;
2402
2403 /* this array is used to reorder sections in the output file */
2404 sec_order = tcc_malloc(sizeof(int) * shnum);
2405 sec_order[0] = 0;
2406
2407 /* compute number of program headers */
2408 switch(file_type) {
2409 default:
2410 case TCC_OUTPUT_OBJ:
2411 phnum = 0;
2412 break;
2413 case TCC_OUTPUT_EXE:
2414 if (!s1->static_link)
2415 phnum = 4 + HAVE_PHDR;
2416 else
2417 phnum = 2;
2418 break;
2419 case TCC_OUTPUT_DLL:
2420 phnum = 3;
2421 break;
2422 }
2423
2424 /* Allocate strings for section names */
2425 alloc_sec_names(s1, file_type, strsec);
2426
2427 /* allocate program segment headers */
2428 phdr = tcc_mallocz(phnum * sizeof(ElfW(Phdr)));
2429
2430 /* compute section to program header mapping */
2431 file_offset = layout_sections(s1, phdr, phnum, interp, strsec, &dyninf,
2432 sec_order);
2433
2434 /* Fill remaining program header and finalize relocation related to dynamic
2435 linking. */
2436 if (phnum > 0) {
2437 fill_unloadable_phdr(phdr, phnum, interp, dynamic);
2438 if (dynamic) {
2439 dyninf.dynamic = dynamic;
2440 dyninf.dynstr = dynstr;
2441
2442 fill_dynamic(s1, &dyninf);
2443
2444 /* put in GOT the dynamic section address and relocate PLT */
2445 put32(s1->got->data, dynamic->sh_addr);
2446 if (file_type == TCC_OUTPUT_EXE
2447 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
2448 || file_type == TCC_OUTPUT_DLL
2449 #endif
2450 )
2451 relocate_plt(s1);
2452
2453 /* relocate symbols in .dynsym now that final addresses are known */
2454 for_each_elem(s1->dynsym, 1, sym, ElfW(Sym)) {
2455 /* relocate to PLT if symbol corresponds to a PLT entry */
2456 if (sym->st_shndx == SHN_UNDEF) {
2457 if (sym->st_value)
2458 sym->st_value += s1->plt->sh_addr;
2459 } else if (sym->st_shndx < SHN_LORESERVE) {
2460 /* do symbol relocation */
2461 sym->st_value += s1->sections[sym->st_shndx]->sh_addr;
2462 }
2463 }
2464 }
2465 }
2466
2467 /* if building executable or DLL, then relocate each section
2468 except the GOT which is already relocated */
2469 if (file_type != TCC_OUTPUT_OBJ) {
2470 ret = final_sections_reloc(s1);
2471 if (ret)
2472 goto the_end;
2473 }
2474
2475 /* Perform relocation to GOT or PLT entries */
2476 if (file_type == TCC_OUTPUT_EXE && s1->static_link)
2477 fill_got(s1);
2478
2479 /* Create the ELF file with name 'filename' */
2480 ret = tcc_write_elf_file(s1, filename, phnum, phdr, file_offset, sec_order);
2481 the_end:
2482 tcc_free(s1->symtab_to_dynsym);
2483 tcc_free(sec_order);
2484 tcc_free(phdr);
2485 tcc_free(s1->sym_attrs);
2486 s1->sym_attrs = NULL;
2487 return ret;
2488 }
2489
2490 LIBTCCAPI int tcc_output_file(TCCState *s, const char *filename)
2491 {
2492 int ret;
2493 #ifdef TCC_TARGET_PE
2494 if (s->output_type != TCC_OUTPUT_OBJ) {
2495 ret = pe_output_file(s, filename);
2496 } else
2497 #endif
2498 ret = elf_output_file(s, filename);
2499 return ret;
2500 }
2501
2502 static void *load_data(int fd, unsigned long file_offset, unsigned long size)
2503 {
2504 void *data;
2505
2506 data = tcc_malloc(size);
2507 lseek(fd, file_offset, SEEK_SET);
2508 read(fd, data, size);
2509 return data;
2510 }
2511
2512 typedef struct SectionMergeInfo {
2513 Section *s; /* corresponding existing section */
2514 unsigned long offset; /* offset of the new section in the existing section */
2515 uint8_t new_section; /* true if section 's' was added */
2516 uint8_t link_once; /* true if link once section */
2517 } SectionMergeInfo;
2518
2519 /* load an object file and merge it with current files */
2520 /* XXX: handle correctly stab (debug) info */
2521 ST_FUNC int tcc_load_object_file(TCCState *s1,
2522 int fd, unsigned long file_offset)
2523 {
2524 ElfW(Ehdr) ehdr;
2525 ElfW(Shdr) *shdr, *sh;
2526 int size, i, j, offset, offseti, nb_syms, sym_index, ret;
2527 unsigned char *strsec, *strtab;
2528 int *old_to_new_syms;
2529 char *sh_name, *name;
2530 SectionMergeInfo *sm_table, *sm;
2531 ElfW(Sym) *sym, *symtab;
2532 ElfW_Rel *rel;
2533 Section *s;
2534
2535 int stab_index;
2536 int stabstr_index;
2537
2538 stab_index = stabstr_index = 0;
2539
2540 if (read(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr))
2541 goto fail1;
2542 if (ehdr.e_ident[0] != ELFMAG0 ||
2543 ehdr.e_ident[1] != ELFMAG1 ||
2544 ehdr.e_ident[2] != ELFMAG2 ||
2545 ehdr.e_ident[3] != ELFMAG3)
2546 goto fail1;
2547 /* test if object file */
2548 if (ehdr.e_type != ET_REL)
2549 goto fail1;
2550 /* test CPU specific stuff */
2551 if (ehdr.e_ident[5] != ELFDATA2LSB ||
2552 ehdr.e_machine != EM_TCC_TARGET) {
2553 fail1:
2554 tcc_error_noabort("invalid object file");
2555 return -1;
2556 }
2557 /* read sections */
2558 shdr = load_data(fd, file_offset + ehdr.e_shoff,
2559 sizeof(ElfW(Shdr)) * ehdr.e_shnum);
2560 sm_table = tcc_mallocz(sizeof(SectionMergeInfo) * ehdr.e_shnum);
2561
2562 /* load section names */
2563 sh = &shdr[ehdr.e_shstrndx];
2564 strsec = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2565
2566 /* load symtab and strtab */
2567 old_to_new_syms = NULL;
2568 symtab = NULL;
2569 strtab = NULL;
2570 nb_syms = 0;
2571 for(i = 1; i < ehdr.e_shnum; i++) {
2572 sh = &shdr[i];
2573 if (sh->sh_type == SHT_SYMTAB) {
2574 if (symtab) {
2575 tcc_error_noabort("object must contain only one symtab");
2576 fail:
2577 ret = -1;
2578 goto the_end;
2579 }
2580 nb_syms = sh->sh_size / sizeof(ElfW(Sym));
2581 symtab = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2582 sm_table[i].s = symtab_section;
2583
2584 /* now load strtab */
2585 sh = &shdr[sh->sh_link];
2586 strtab = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2587 }
2588 }
2589
2590 /* now examine each section and try to merge its content with the
2591 ones in memory */
2592 for(i = 1; i < ehdr.e_shnum; i++) {
2593 /* no need to examine section name strtab */
2594 if (i == ehdr.e_shstrndx)
2595 continue;
2596 sh = &shdr[i];
2597 sh_name = (char *) strsec + sh->sh_name;
2598 /* ignore sections types we do not handle */
2599 if (sh->sh_type != SHT_PROGBITS &&
2600 sh->sh_type != SHT_RELX &&
2601 #ifdef TCC_ARM_EABI
2602 sh->sh_type != SHT_ARM_EXIDX &&
2603 #endif
2604 sh->sh_type != SHT_NOBITS &&
2605 sh->sh_type != SHT_PREINIT_ARRAY &&
2606 sh->sh_type != SHT_INIT_ARRAY &&
2607 sh->sh_type != SHT_FINI_ARRAY &&
2608 strcmp(sh_name, ".stabstr")
2609 )
2610 continue;
2611 if (sh->sh_addralign < 1)
2612 sh->sh_addralign = 1;
2613 /* find corresponding section, if any */
2614 for(j = 1; j < s1->nb_sections;j++) {
2615 s = s1->sections[j];
2616 if (!strcmp(s->name, sh_name)) {
2617 if (!strncmp(sh_name, ".gnu.linkonce",
2618 sizeof(".gnu.linkonce") - 1)) {
2619 /* if a 'linkonce' section is already present, we
2620 do not add it again. It is a little tricky as
2621 symbols can still be defined in
2622 it. */
2623 sm_table[i].link_once = 1;
2624 goto next;
2625 } else {
2626 goto found;
2627 }
2628 }
2629 }
2630 /* not found: create new section */
2631 s = new_section(s1, sh_name, sh->sh_type, sh->sh_flags);
2632 /* take as much info as possible from the section. sh_link and
2633 sh_info will be updated later */
2634 s->sh_addralign = sh->sh_addralign;
2635 s->sh_entsize = sh->sh_entsize;
2636 sm_table[i].new_section = 1;
2637 found:
2638 if (sh->sh_type != s->sh_type) {
2639 tcc_error_noabort("invalid section type");
2640 goto fail;
2641 }
2642
2643 /* align start of section */
2644 offset = s->data_offset;
2645
2646 if (0 == strcmp(sh_name, ".stab")) {
2647 stab_index = i;
2648 goto no_align;
2649 }
2650 if (0 == strcmp(sh_name, ".stabstr")) {
2651 stabstr_index = i;
2652 goto no_align;
2653 }
2654
2655 size = sh->sh_addralign - 1;
2656 offset = (offset + size) & ~size;
2657 if (sh->sh_addralign > s->sh_addralign)
2658 s->sh_addralign = sh->sh_addralign;
2659 s->data_offset = offset;
2660 no_align:
2661 sm_table[i].offset = offset;
2662 sm_table[i].s = s;
2663 /* concatenate sections */
2664 size = sh->sh_size;
2665 if (sh->sh_type != SHT_NOBITS) {
2666 unsigned char *ptr;
2667 lseek(fd, file_offset + sh->sh_offset, SEEK_SET);
2668 ptr = section_ptr_add(s, size);
2669 read(fd, ptr, size);
2670 } else {
2671 s->data_offset += size;
2672 }
2673 next: ;
2674 }
2675
2676 /* gr relocate stab strings */
2677 if (stab_index && stabstr_index) {
2678 Stab_Sym *a, *b;
2679 unsigned o;
2680 s = sm_table[stab_index].s;
2681 a = (Stab_Sym *)(s->data + sm_table[stab_index].offset);
2682 b = (Stab_Sym *)(s->data + s->data_offset);
2683 o = sm_table[stabstr_index].offset;
2684 while (a < b)
2685 a->n_strx += o, a++;
2686 }
2687
2688 /* second short pass to update sh_link and sh_info fields of new
2689 sections */
2690 for(i = 1; i < ehdr.e_shnum; i++) {
2691 s = sm_table[i].s;
2692 if (!s || !sm_table[i].new_section)
2693 continue;
2694 sh = &shdr[i];
2695 if (sh->sh_link > 0)
2696 s->link = sm_table[sh->sh_link].s;
2697 if (sh->sh_type == SHT_RELX) {
2698 s->sh_info = sm_table[sh->sh_info].s->sh_num;
2699 /* update backward link */
2700 s1->sections[s->sh_info]->reloc = s;
2701 }
2702 }
2703 sm = sm_table;
2704
2705 /* resolve symbols */
2706 old_to_new_syms = tcc_mallocz(nb_syms * sizeof(int));
2707
2708 sym = symtab + 1;
2709 for(i = 1; i < nb_syms; i++, sym++) {
2710 if (sym->st_shndx != SHN_UNDEF &&
2711 sym->st_shndx < SHN_LORESERVE) {
2712 sm = &sm_table[sym->st_shndx];
2713 if (sm->link_once) {
2714 /* if a symbol is in a link once section, we use the
2715 already defined symbol. It is very important to get
2716 correct relocations */
2717 if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
2718 name = (char *) strtab + sym->st_name;
2719 sym_index = find_elf_sym(symtab_section, name);
2720 if (sym_index)
2721 old_to_new_syms[i] = sym_index;
2722 }
2723 continue;
2724 }
2725 /* if no corresponding section added, no need to add symbol */
2726 if (!sm->s)
2727 continue;
2728 /* convert section number */
2729 sym->st_shndx = sm->s->sh_num;
2730 /* offset value */
2731 sym->st_value += sm->offset;
2732 }
2733 /* add symbol */
2734 name = (char *) strtab + sym->st_name;
2735 sym_index = add_elf_sym(symtab_section, sym->st_value, sym->st_size,
2736 sym->st_info, sym->st_other,
2737 sym->st_shndx, name);
2738 old_to_new_syms[i] = sym_index;
2739 }
2740
2741 /* third pass to patch relocation entries */
2742 for(i = 1; i < ehdr.e_shnum; i++) {
2743 s = sm_table[i].s;
2744 if (!s)
2745 continue;
2746 sh = &shdr[i];
2747 offset = sm_table[i].offset;
2748 switch(s->sh_type) {
2749 case SHT_RELX:
2750 /* take relocation offset information */
2751 offseti = sm_table[sh->sh_info].offset;
2752 for_each_elem(s, (offset / sizeof(*rel)), rel, ElfW_Rel) {
2753 int type;
2754 unsigned sym_index;
2755 /* convert symbol index */
2756 type = ELFW(R_TYPE)(rel->r_info);
2757 sym_index = ELFW(R_SYM)(rel->r_info);
2758 /* NOTE: only one symtab assumed */
2759 if (sym_index >= nb_syms)
2760 goto invalid_reloc;
2761 sym_index = old_to_new_syms[sym_index];
2762 /* ignore link_once in rel section. */
2763 if (!sym_index && !sm->link_once
2764 #ifdef TCC_TARGET_ARM
2765 && type != R_ARM_V4BX
2766 #endif
2767 ) {
2768 invalid_reloc:
2769 tcc_error_noabort("Invalid relocation entry [%2d] '%s' @ %.8x",
2770 i, strsec + sh->sh_name, rel->r_offset);
2771 goto fail;
2772 }
2773 rel->r_info = ELFW(R_INFO)(sym_index, type);
2774 /* offset the relocation offset */
2775 rel->r_offset += offseti;
2776 #ifdef TCC_TARGET_ARM
2777 /* Jumps and branches from a Thumb code to a PLT entry need
2778 special handling since PLT entries are ARM code.
2779 Unconditional bl instructions referencing PLT entries are
2780 handled by converting these instructions into blx
2781 instructions. Other case of instructions referencing a PLT
2782 entry require to add a Thumb stub before the PLT entry to
2783 switch to ARM mode. We set bit plt_thumb_stub of the
2784 attribute of a symbol to indicate such a case. */
2785 if (type == R_ARM_THM_JUMP24)
2786 alloc_sym_attr(s1, sym_index)->plt_thumb_stub = 1;
2787 #endif
2788 }
2789 break;
2790 default:
2791 break;
2792 }
2793 }
2794
2795 ret = 0;
2796 the_end:
2797 tcc_free(symtab);
2798 tcc_free(strtab);
2799 tcc_free(old_to_new_syms);
2800 tcc_free(sm_table);
2801 tcc_free(strsec);
2802 tcc_free(shdr);
2803 return ret;
2804 }
2805
2806 typedef struct ArchiveHeader {
2807 char ar_name[16]; /* name of this member */
2808 char ar_date[12]; /* file mtime */
2809 char ar_uid[6]; /* owner uid; printed as decimal */
2810 char ar_gid[6]; /* owner gid; printed as decimal */
2811 char ar_mode[8]; /* file mode, printed as octal */
2812 char ar_size[10]; /* file size, printed as decimal */
2813 char ar_fmag[2]; /* should contain ARFMAG */
2814 } ArchiveHeader;
2815
2816 static int get_be32(const uint8_t *b)
2817 {
2818 return b[3] | (b[2] << 8) | (b[1] << 16) | (b[0] << 24);
2819 }
2820
2821 /* load only the objects which resolve undefined symbols */
2822 static int tcc_load_alacarte(TCCState *s1, int fd, int size)
2823 {
2824 int i, bound, nsyms, sym_index, off, ret;
2825 uint8_t *data;
2826 const char *ar_names, *p;
2827 const uint8_t *ar_index;
2828 ElfW(Sym) *sym;
2829
2830 data = tcc_malloc(size);
2831 if (read(fd, data, size) != size)
2832 goto fail;
2833 nsyms = get_be32(data);
2834 ar_index = data + 4;
2835 ar_names = (char *) ar_index + nsyms * 4;
2836
2837 do {
2838 bound = 0;
2839 for(p = ar_names, i = 0; i < nsyms; i++, p += strlen(p)+1) {
2840 sym_index = find_elf_sym(symtab_section, p);
2841 if(sym_index) {
2842 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
2843 if(sym->st_shndx == SHN_UNDEF) {
2844 off = get_be32(ar_index + i * 4) + sizeof(ArchiveHeader);
2845 ++bound;
2846 lseek(fd, off, SEEK_SET);
2847 if(tcc_load_object_file(s1, fd, off) < 0) {
2848 fail:
2849 ret = -1;
2850 goto the_end;
2851 }
2852 }
2853 }
2854 }
2855 } while(bound);
2856 ret = 0;
2857 the_end:
2858 tcc_free(data);
2859 return ret;
2860 }
2861
2862 /* load a '.a' file */
2863 ST_FUNC int tcc_load_archive(TCCState *s1, int fd)
2864 {
2865 ArchiveHeader hdr;
2866 char ar_size[11];
2867 char ar_name[17];
2868 char magic[8];
2869 int size, len, i;
2870 unsigned long file_offset;
2871
2872 /* skip magic which was already checked */
2873 read(fd, magic, sizeof(magic));
2874
2875 for(;;) {
2876 len = read(fd, &hdr, sizeof(hdr));
2877 if (len == 0)
2878 break;
2879 if (len != sizeof(hdr)) {
2880 tcc_error_noabort("invalid archive");
2881 return -1;
2882 }
2883 memcpy(ar_size, hdr.ar_size, sizeof(hdr.ar_size));
2884 ar_size[sizeof(hdr.ar_size)] = '\0';
2885 size = strtol(ar_size, NULL, 0);
2886 memcpy(ar_name, hdr.ar_name, sizeof(hdr.ar_name));
2887 for(i = sizeof(hdr.ar_name) - 1; i >= 0; i--) {
2888 if (ar_name[i] != ' ')
2889 break;
2890 }
2891 ar_name[i + 1] = '\0';
2892 file_offset = lseek(fd, 0, SEEK_CUR);
2893 /* align to even */
2894 size = (size + 1) & ~1;
2895 if (!strcmp(ar_name, "/")) {
2896 /* coff symbol table : we handle it */
2897 if(s1->alacarte_link)
2898 return tcc_load_alacarte(s1, fd, size);
2899 } else if (!strcmp(ar_name, "//") ||
2900 !strcmp(ar_name, "__.SYMDEF") ||
2901 !strcmp(ar_name, "__.SYMDEF/") ||
2902 !strcmp(ar_name, "ARFILENAMES/")) {
2903 /* skip symbol table or archive names */
2904 } else {
2905 if (tcc_load_object_file(s1, fd, file_offset) < 0)
2906 return -1;
2907 }
2908 lseek(fd, file_offset + size, SEEK_SET);
2909 }
2910 return 0;
2911 }
2912
2913 #ifndef TCC_TARGET_PE
2914 /* load a DLL and all referenced DLLs. 'level = 0' means that the DLL
2915 is referenced by the user (so it should be added as DT_NEEDED in
2916 the generated ELF file) */
2917 ST_FUNC int tcc_load_dll(TCCState *s1, int fd, const char *filename, int level)
2918 {
2919 ElfW(Ehdr) ehdr;
2920 ElfW(Shdr) *shdr, *sh, *sh1;
2921 int i, j, nb_syms, nb_dts, sym_bind, ret;
2922 ElfW(Sym) *sym, *dynsym;
2923 ElfW(Dyn) *dt, *dynamic;
2924 unsigned char *dynstr;
2925 const char *name, *soname;
2926 DLLReference *dllref;
2927
2928 read(fd, &ehdr, sizeof(ehdr));
2929
2930 /* test CPU specific stuff */
2931 if (ehdr.e_ident[5] != ELFDATA2LSB ||
2932 ehdr.e_machine != EM_TCC_TARGET) {
2933 tcc_error_noabort("bad architecture");
2934 return -1;
2935 }
2936
2937 /* read sections */
2938 shdr = load_data(fd, ehdr.e_shoff, sizeof(ElfW(Shdr)) * ehdr.e_shnum);
2939
2940 /* load dynamic section and dynamic symbols */
2941 nb_syms = 0;
2942 nb_dts = 0;
2943 dynamic = NULL;
2944 dynsym = NULL; /* avoid warning */
2945 dynstr = NULL; /* avoid warning */
2946 for(i = 0, sh = shdr; i < ehdr.e_shnum; i++, sh++) {
2947 switch(sh->sh_type) {
2948 case SHT_DYNAMIC:
2949 nb_dts = sh->sh_size / sizeof(ElfW(Dyn));
2950 dynamic = load_data(fd, sh->sh_offset, sh->sh_size);
2951 break;
2952 case SHT_DYNSYM:
2953 nb_syms = sh->sh_size / sizeof(ElfW(Sym));
2954 dynsym = load_data(fd, sh->sh_offset, sh->sh_size);
2955 sh1 = &shdr[sh->sh_link];
2956 dynstr = load_data(fd, sh1->sh_offset, sh1->sh_size);
2957 break;
2958 default:
2959 break;
2960 }
2961 }
2962
2963 /* compute the real library name */
2964 soname = tcc_basename(filename);
2965
2966 for(i = 0, dt = dynamic; i < nb_dts; i++, dt++) {
2967 if (dt->d_tag == DT_SONAME) {
2968 soname = (char *) dynstr + dt->d_un.d_val;
2969 }
2970 }
2971
2972 /* if the dll is already loaded, do not load it */
2973 for(i = 0; i < s1->nb_loaded_dlls; i++) {
2974 dllref = s1->loaded_dlls[i];
2975 if (!strcmp(soname, dllref->name)) {
2976 /* but update level if needed */
2977 if (level < dllref->level)
2978 dllref->level = level;
2979 ret = 0;
2980 goto the_end;
2981 }
2982 }
2983
2984 /* add the dll and its level */
2985 dllref = tcc_mallocz(sizeof(DLLReference) + strlen(soname));
2986 dllref->level = level;
2987 strcpy(dllref->name, soname);
2988 dynarray_add((void ***)&s1->loaded_dlls, &s1->nb_loaded_dlls, dllref);
2989
2990 /* add dynamic symbols in dynsym_section */
2991 for(i = 1, sym = dynsym + 1; i < nb_syms; i++, sym++) {
2992 sym_bind = ELFW(ST_BIND)(sym->st_info);
2993 if (sym_bind == STB_LOCAL)
2994 continue;
2995 name = (char *) dynstr + sym->st_name;
2996 add_elf_sym(s1->dynsymtab_section, sym->st_value, sym->st_size,
2997 sym->st_info, sym->st_other, sym->st_shndx, name);
2998 }
2999
3000 /* load all referenced DLLs */
3001 for(i = 0, dt = dynamic; i < nb_dts; i++, dt++) {
3002 switch(dt->d_tag) {
3003 case DT_NEEDED:
3004 name = (char *) dynstr + dt->d_un.d_val;
3005 for(j = 0; j < s1->nb_loaded_dlls; j++) {
3006 dllref = s1->loaded_dlls[j];
3007 if (!strcmp(name, dllref->name))
3008 goto already_loaded;
3009 }
3010 if (tcc_add_dll(s1, name, AFF_REFERENCED_DLL) < 0) {
3011 tcc_error_noabort("referenced dll '%s' not found", name);
3012 ret = -1;
3013 goto the_end;
3014 }
3015 already_loaded:
3016 break;
3017 }
3018 }
3019 ret = 0;
3020 the_end:
3021 tcc_free(dynstr);
3022 tcc_free(dynsym);
3023 tcc_free(dynamic);
3024 tcc_free(shdr);
3025 return ret;
3026 }
3027
3028 #define LD_TOK_NAME 256
3029 #define LD_TOK_EOF (-1)
3030
3031 /* return next ld script token */
3032 static int ld_next(TCCState *s1, char *name, int name_size)
3033 {
3034 int c;
3035 char *q;
3036
3037 redo:
3038 switch(ch) {
3039 case ' ':
3040 case '\t':
3041 case '\f':
3042 case '\v':
3043 case '\r':
3044 case '\n':
3045 inp();
3046 goto redo;
3047 case '/':
3048 minp();
3049 if (ch == '*') {
3050 file->buf_ptr = parse_comment(file->buf_ptr);
3051 ch = file->buf_ptr[0];
3052 goto redo;
3053 } else {
3054 q = name;
3055 *q++ = '/';
3056 goto parse_name;
3057 }
3058 break;
3059 /* case 'a' ... 'z': */
3060 case 'a':
3061 case 'b':
3062 case 'c':
3063 case 'd':
3064 case 'e':
3065 case 'f':
3066 case 'g':
3067 case 'h':
3068 case 'i':
3069 case 'j':
3070 case 'k':
3071 case 'l':
3072 case 'm':
3073 case 'n':
3074 case 'o':
3075 case 'p':
3076 case 'q':
3077 case 'r':
3078 case 's':
3079 case 't':
3080 case 'u':
3081 case 'v':
3082 case 'w':
3083 case 'x':
3084 case 'y':
3085 case 'z':
3086 /* case 'A' ... 'z': */
3087 case 'A':
3088 case 'B':
3089 case 'C':
3090 case 'D':
3091 case 'E':
3092 case 'F':
3093 case 'G':
3094 case 'H':
3095 case 'I':
3096 case 'J':
3097 case 'K':
3098 case 'L':
3099 case 'M':
3100 case 'N':
3101 case 'O':
3102 case 'P':
3103 case 'Q':
3104 case 'R':
3105 case 'S':
3106 case 'T':
3107 case 'U':
3108 case 'V':
3109 case 'W':
3110 case 'X':
3111 case 'Y':
3112 case 'Z':
3113 case '_':
3114 case '\\':
3115 case '.':
3116 case '$':
3117 case '~':
3118 q = name;
3119 parse_name:
3120 for(;;) {
3121 if (!((ch >= 'a' && ch <= 'z') ||
3122 (ch >= 'A' && ch <= 'Z') ||
3123 (ch >= '0' && ch <= '9') ||
3124 strchr("/.-_+=$:\\,~", ch)))
3125 break;
3126 if ((q - name) < name_size - 1) {
3127 *q++ = ch;
3128 }
3129 minp();
3130 }
3131 *q = '\0';
3132 c = LD_TOK_NAME;
3133 break;
3134 case CH_EOF:
3135 c = LD_TOK_EOF;
3136 break;
3137 default:
3138 c = ch;
3139 inp();
3140 break;
3141 }
3142 return c;
3143 }
3144
3145 static int ld_add_file(TCCState *s1, const char filename[])
3146 {
3147 int ret;
3148
3149 ret = tcc_add_file_internal(s1, filename, 0);
3150 if (ret)
3151 ret = tcc_add_dll(s1, filename, 0);
3152 return ret;
3153 }
3154
3155 static inline int new_undef_syms(void)
3156 {
3157 int ret = 0;
3158 ret = new_undef_sym;
3159 new_undef_sym = 0;
3160 return ret;
3161 }
3162
3163 static int ld_add_file_list(TCCState *s1, const char *cmd, int as_needed)
3164 {
3165 char filename[1024], libname[1024];
3166 int t, group, nblibs = 0, ret = 0;
3167 char **libs = NULL;
3168
3169 group = !strcmp(cmd, "GROUP");
3170 if (!as_needed)
3171 new_undef_syms();
3172 t = ld_next(s1, filename, sizeof(filename));
3173 if (t != '(')
3174 expect("(");
3175 t = ld_next(s1, filename, sizeof(filename));
3176 for(;;) {
3177 libname[0] = '\0';
3178 if (t == LD_TOK_EOF) {
3179 tcc_error_noabort("unexpected end of file");
3180 ret = -1;
3181 goto lib_parse_error;
3182 } else if (t == ')') {
3183 break;
3184 } else if (t == '-') {
3185 t = ld_next(s1, filename, sizeof(filename));
3186 if ((t != LD_TOK_NAME) || (filename[0] != 'l')) {
3187 tcc_error_noabort("library name expected");
3188 ret = -1;
3189 goto lib_parse_error;
3190 }
3191 pstrcpy(libname, sizeof libname, &filename[1]);
3192 if (s1->static_link) {
3193 snprintf(filename, sizeof filename, "lib%s.a", libname);
3194 } else {
3195 snprintf(filename, sizeof filename, "lib%s.so", libname);
3196 }
3197 } else if (t != LD_TOK_NAME) {
3198 tcc_error_noabort("filename expected");
3199 ret = -1;
3200 goto lib_parse_error;
3201 }
3202 if (!strcmp(filename, "AS_NEEDED")) {
3203 ret = ld_add_file_list(s1, cmd, 1);
3204 if (ret)
3205 goto lib_parse_error;
3206 } else {
3207 /* TODO: Implement AS_NEEDED support. Ignore it for now */
3208 if (!as_needed) {
3209 ret = ld_add_file(s1, filename);
3210 if (ret)
3211 goto lib_parse_error;
3212 if (group) {
3213 /* Add the filename *and* the libname to avoid future conversions */
3214 dynarray_add((void ***) &libs, &nblibs, tcc_strdup(filename));
3215 if (libname[0] != '\0')
3216 dynarray_add((void ***) &libs, &nblibs, tcc_strdup(libname));
3217 }
3218 }
3219 }
3220 t = ld_next(s1, filename, sizeof(filename));
3221 if (t == ',') {
3222 t = ld_next(s1, filename, sizeof(filename));
3223 }
3224 }
3225 if (group && !as_needed) {
3226 while (new_undef_syms()) {
3227 int i;
3228
3229 for (i = 0; i < nblibs; i ++)
3230 ld_add_file(s1, libs[i]);
3231 }
3232 }
3233 lib_parse_error:
3234 dynarray_reset(&libs, &nblibs);
3235 return ret;
3236 }
3237
3238 /* interpret a subset of GNU ldscripts to handle the dummy libc.so
3239 files */
3240 ST_FUNC int tcc_load_ldscript(TCCState *s1)
3241 {
3242 char cmd[64];
3243 char filename[1024];
3244 int t, ret;
3245
3246 ch = file->buf_ptr[0];
3247 ch = handle_eob();
3248 for(;;) {
3249 t = ld_next(s1, cmd, sizeof(cmd));
3250 if (t == LD_TOK_EOF)
3251 return 0;
3252 else if (t != LD_TOK_NAME)
3253 return -1;
3254 if (!strcmp(cmd, "INPUT") ||
3255 !strcmp(cmd, "GROUP")) {
3256 ret = ld_add_file_list(s1, cmd, 0);
3257 if (ret)
3258 return ret;
3259 } else if (!strcmp(cmd, "OUTPUT_FORMAT") ||
3260 !strcmp(cmd, "TARGET")) {
3261 /* ignore some commands */
3262 t = ld_next(s1, cmd, sizeof(cmd));
3263 if (t != '(')
3264 expect("(");
3265 for(;;) {
3266 t = ld_next(s1, filename, sizeof(filename));
3267 if (t == LD_TOK_EOF) {
3268 tcc_error_noabort("unexpected end of file");
3269 return -1;
3270 } else if (t == ')') {
3271 break;
3272 }
3273 }
3274 } else {
3275 return -1;
3276 }
3277 }
3278 return 0;
3279 }
3280 #endif /* !TCC_TARGET_PE */