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Call fill_got_entry unconditionally
[tinycc.git] / tccelf.c
blob321ec2eebfb6b2e6edd5bc068d1dfdcf3e8df9b1
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 /* XXX: avoid static variable */
24 static int new_undef_sym = 0; /* Is there a new undefined sym since last new_undef_sym() */
25
26 ST_FUNC int put_elf_str(Section *s, const char *sym)
27 {
28 int offset, len;
29 char *ptr;
30
31 len = strlen(sym) + 1;
32 offset = s->data_offset;
33 ptr = section_ptr_add(s, len);
34 memcpy(ptr, sym, len);
35 return offset;
36 }
37
38 /* elf symbol hashing function */
39 static unsigned long elf_hash(const unsigned char *name)
40 {
41 unsigned long h = 0, g;
42
43 while (*name) {
44 h = (h << 4) + *name++;
45 g = h & 0xf0000000;
46 if (g)
47 h ^= g >> 24;
48 h &= ~g;
49 }
50 return h;
51 }
52
53 /* rebuild hash table of section s */
54 /* NOTE: we do factorize the hash table code to go faster */
55 static void rebuild_hash(Section *s, unsigned int nb_buckets)
56 {
57 ElfW(Sym) *sym;
58 int *ptr, *hash, nb_syms, sym_index, h;
59 char *strtab;
60
61 strtab = s->link->data;
62 nb_syms = s->data_offset / sizeof(ElfW(Sym));
63
64 s->hash->data_offset = 0;
65 ptr = section_ptr_add(s->hash, (2 + nb_buckets + nb_syms) * sizeof(int));
66 ptr[0] = nb_buckets;
67 ptr[1] = nb_syms;
68 ptr += 2;
69 hash = ptr;
70 memset(hash, 0, (nb_buckets + 1) * sizeof(int));
71 ptr += nb_buckets + 1;
72
73 sym = (ElfW(Sym) *)s->data + 1;
74 for(sym_index = 1; sym_index < nb_syms; sym_index++) {
75 if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
76 h = elf_hash(strtab + sym->st_name) % nb_buckets;
77 *ptr = hash[h];
78 hash[h] = sym_index;
79 } else {
80 *ptr = 0;
81 }
82 ptr++;
83 sym++;
84 }
85 }
86
87 /* return the symbol number */
88 ST_FUNC int put_elf_sym(Section *s, addr_t value, unsigned long size,
89 int info, int other, int shndx, const char *name)
90 {
91 int name_offset, sym_index;
92 int nbuckets, h;
93 ElfW(Sym) *sym;
94 Section *hs;
95
96 sym = section_ptr_add(s, sizeof(ElfW(Sym)));
97 if (name)
98 name_offset = put_elf_str(s->link, name);
99 else
100 name_offset = 0;
101 /* XXX: endianness */
102 sym->st_name = name_offset;
103 sym->st_value = value;
104 sym->st_size = size;
105 sym->st_info = info;
106 sym->st_other = other;
107 sym->st_shndx = shndx;
108 sym_index = sym - (ElfW(Sym) *)s->data;
109 hs = s->hash;
110 if (hs) {
111 int *ptr, *base;
112 ptr = section_ptr_add(hs, sizeof(int));
113 base = (int *)hs->data;
114 /* only add global or weak symbols */
115 if (ELFW(ST_BIND)(info) != STB_LOCAL) {
116 /* add another hashing entry */
117 nbuckets = base[0];
118 h = elf_hash(name) % nbuckets;
119 *ptr = base[2 + h];
120 base[2 + h] = sym_index;
121 base[1]++;
122 /* we resize the hash table */
123 hs->nb_hashed_syms++;
124 if (hs->nb_hashed_syms > 2 * nbuckets) {
125 rebuild_hash(s, 2 * nbuckets);
126 }
127 } else {
128 *ptr = 0;
129 base[1]++;
130 }
131 }
132 return sym_index;
133 }
134
135 /* find global ELF symbol 'name' and return its index. Return 0 if not
136 found. */
137 ST_FUNC int find_elf_sym(Section *s, const char *name)
138 {
139 ElfW(Sym) *sym;
140 Section *hs;
141 int nbuckets, sym_index, h;
142 const char *name1;
143
144 hs = s->hash;
145 if (!hs)
146 return 0;
147 nbuckets = ((int *)hs->data)[0];
148 h = elf_hash(name) % nbuckets;
149 sym_index = ((int *)hs->data)[2 + h];
150 while (sym_index != 0) {
151 sym = &((ElfW(Sym) *)s->data)[sym_index];
152 name1 = s->link->data + sym->st_name;
153 if (!strcmp(name, name1))
154 return sym_index;
155 sym_index = ((int *)hs->data)[2 + nbuckets + sym_index];
156 }
157 return 0;
158 }
159
160 /* return elf symbol value, signal error if 'err' is nonzero */
161 ST_FUNC addr_t get_elf_sym_addr(TCCState *s, const char *name, int err)
162 {
163 int sym_index;
164 ElfW(Sym) *sym;
165
166 sym_index = find_elf_sym(s->symtab, name);
167 sym = &((ElfW(Sym) *)s->symtab->data)[sym_index];
168 if (!sym_index || sym->st_shndx == SHN_UNDEF) {
169 if (err)
170 tcc_error("%s not defined", name);
171 return 0;
172 }
173 return sym->st_value;
174 }
175
176 /* return elf symbol value */
177 LIBTCCAPI void *tcc_get_symbol(TCCState *s, const char *name)
178 {
179 return (void*)(uintptr_t)get_elf_sym_addr(s, name, 0);
180 }
181
182 #if defined TCC_IS_NATIVE || defined TCC_TARGET_PE
183 /* return elf symbol value or error */
184 ST_FUNC void* tcc_get_symbol_err(TCCState *s, const char *name)
185 {
186 return (void*)(uintptr_t)get_elf_sym_addr(s, name, 1);
187 }
188 #endif
189
190 /* add an elf symbol : check if it is already defined and patch
191 it. Return symbol index. NOTE that sh_num can be SHN_UNDEF. */
192 ST_FUNC int add_elf_sym(Section *s, addr_t value, unsigned long size,
193 int info, int other, int sh_num, const char *name)
194 {
195 ElfW(Sym) *esym;
196 int sym_bind, sym_index, sym_type, esym_bind;
197 unsigned char sym_vis, esym_vis, new_vis;
198
199 sym_bind = ELFW(ST_BIND)(info);
200 sym_type = ELFW(ST_TYPE)(info);
201 sym_vis = ELFW(ST_VISIBILITY)(other);
202
203 if (sym_bind != STB_LOCAL) {
204 /* we search global or weak symbols */
205 sym_index = find_elf_sym(s, name);
206 if (!sym_index)
207 goto do_def;
208 esym = &((ElfW(Sym) *)s->data)[sym_index];
209 if (esym->st_shndx != SHN_UNDEF) {
210 esym_bind = ELFW(ST_BIND)(esym->st_info);
211 /* propagate the most constraining visibility */
212 /* STV_DEFAULT(0)<STV_PROTECTED(3)<STV_HIDDEN(2)<STV_INTERNAL(1) */
213 esym_vis = ELFW(ST_VISIBILITY)(esym->st_other);
214 if (esym_vis == STV_DEFAULT) {
215 new_vis = sym_vis;
216 } else if (sym_vis == STV_DEFAULT) {
217 new_vis = esym_vis;
218 } else {
219 new_vis = (esym_vis < sym_vis) ? esym_vis : sym_vis;
220 }
221 esym->st_other = (esym->st_other & ~ELFW(ST_VISIBILITY)(-1))
222 | new_vis;
223 other = esym->st_other; /* in case we have to patch esym */
224 if (sh_num == SHN_UNDEF) {
225 /* ignore adding of undefined symbol if the
226 corresponding symbol is already defined */
227 } else if (sym_bind == STB_GLOBAL && esym_bind == STB_WEAK) {
228 /* global overrides weak, so patch */
229 goto do_patch;
230 } else if (sym_bind == STB_WEAK && esym_bind == STB_GLOBAL) {
231 /* weak is ignored if already global */
232 } else if (sym_bind == STB_WEAK && esym_bind == STB_WEAK) {
233 /* keep first-found weak definition, ignore subsequents */
234 } else if (sym_vis == STV_HIDDEN || sym_vis == STV_INTERNAL) {
235 /* ignore hidden symbols after */
236 } else if (esym->st_shndx == SHN_COMMON
237 && (sh_num < SHN_LORESERVE || sh_num == SHN_COMMON)) {
238 /* gr: Happens with 'tcc ... -static tcctest.c' on e.g. Ubuntu 6.01
239 No idea if this is the correct solution ... */
240 goto do_patch;
241 } else if (s == tcc_state->dynsymtab_section) {
242 /* we accept that two DLL define the same symbol */
243 } else {
244 #if 0
245 printf("new_bind=%x new_shndx=%x new_vis=%x old_bind=%x old_shndx=%x old_vis=%x\n",
246 sym_bind, sh_num, new_vis, esym_bind, esym->st_shndx, esym_vis);
247 #endif
248 tcc_error_noabort("'%s' defined twice", name);
249 }
250 } else {
251 do_patch:
252 esym->st_info = ELFW(ST_INFO)(sym_bind, sym_type);
253 esym->st_shndx = sh_num;
254 new_undef_sym = 1;
255 esym->st_value = value;
256 esym->st_size = size;
257 esym->st_other = other;
258 }
259 } else {
260 do_def:
261 sym_index = put_elf_sym(s, value, size,
262 ELFW(ST_INFO)(sym_bind, sym_type), other,
263 sh_num, name);
264 }
265 return sym_index;
266 }
267
268 /* put relocation */
269 ST_FUNC void put_elf_reloc(Section *symtab, Section *s, unsigned long offset,
270 int type, int symbol)
271 {
272 char buf[256];
273 Section *sr;
274 ElfW_Rel *rel;
275
276 sr = s->reloc;
277 if (!sr) {
278 /* if no relocation section, create it */
279 snprintf(buf, sizeof(buf), REL_SECTION_FMT, s->name);
280 /* if the symtab is allocated, then we consider the relocation
281 are also */
282 sr = new_section(tcc_state, buf, SHT_RELX, symtab->sh_flags);
283 sr->sh_entsize = sizeof(ElfW_Rel);
284 sr->link = symtab;
285 sr->sh_info = s->sh_num;
286 s->reloc = sr;
287 }
288 rel = section_ptr_add(sr, sizeof(ElfW_Rel));
289 rel->r_offset = offset;
290 rel->r_info = ELFW(R_INFO)(symbol, type);
291 #ifdef TCC_TARGET_X86_64
292 rel->r_addend = 0;
293 #endif
294 }
295
296 /* put stab debug information */
297
298 ST_FUNC void put_stabs(const char *str, int type, int other, int desc,
299 unsigned long value)
300 {
301 Stab_Sym *sym;
302
303 sym = section_ptr_add(stab_section, sizeof(Stab_Sym));
304 if (str) {
305 sym->n_strx = put_elf_str(stabstr_section, str);
306 } else {
307 sym->n_strx = 0;
308 }
309 sym->n_type = type;
310 sym->n_other = other;
311 sym->n_desc = desc;
312 sym->n_value = value;
313 }
314
315 ST_FUNC void put_stabs_r(const char *str, int type, int other, int desc,
316 unsigned long value, Section *sec, int sym_index)
317 {
318 put_stabs(str, type, other, desc, value);
319 put_elf_reloc(symtab_section, stab_section,
320 stab_section->data_offset - sizeof(unsigned int),
321 R_DATA_32, sym_index);
322 }
323
324 ST_FUNC void put_stabn(int type, int other, int desc, int value)
325 {
326 put_stabs(NULL, type, other, desc, value);
327 }
328
329 ST_FUNC void put_stabd(int type, int other, int desc)
330 {
331 put_stabs(NULL, type, other, desc, 0);
332 }
333
334 /* Browse each elem of type <type> in section <sec> starting at elem <startoff>
335 using variable <elem> */
336 #define for_each_elem(sec, startoff, elem, type) \
337 for (elem = (type *) sec->data + startoff; \
338 elem < (type *) (sec->data + sec->data_offset); elem++)
339
340 /* In an ELF file symbol table, the local symbols must appear below
341 the global and weak ones. Since TCC cannot sort it while generating
342 the code, we must do it after. All the relocation tables are also
343 modified to take into account the symbol table sorting */
344 static void sort_syms(TCCState *s1, Section *s)
345 {
346 int *old_to_new_syms;
347 ElfW(Sym) *new_syms;
348 int nb_syms, i;
349 ElfW(Sym) *p, *q;
350 ElfW_Rel *rel;
351 Section *sr;
352 int type, sym_index;
353
354 nb_syms = s->data_offset / sizeof(ElfW(Sym));
355 new_syms = tcc_malloc(nb_syms * sizeof(ElfW(Sym)));
356 old_to_new_syms = tcc_malloc(nb_syms * sizeof(int));
357
358 /* first pass for local symbols */
359 p = (ElfW(Sym) *)s->data;
360 q = new_syms;
361 for(i = 0; i < nb_syms; i++) {
362 if (ELFW(ST_BIND)(p->st_info) == STB_LOCAL) {
363 old_to_new_syms[i] = q - new_syms;
364 *q++ = *p;
365 }
366 p++;
367 }
368 /* save the number of local symbols in section header */
369 s->sh_info = q - new_syms;
370
371 /* then second pass for non local symbols */
372 p = (ElfW(Sym) *)s->data;
373 for(i = 0; i < nb_syms; i++) {
374 if (ELFW(ST_BIND)(p->st_info) != STB_LOCAL) {
375 old_to_new_syms[i] = q - new_syms;
376 *q++ = *p;
377 }
378 p++;
379 }
380
381 /* we copy the new symbols to the old */
382 memcpy(s->data, new_syms, nb_syms * sizeof(ElfW(Sym)));
383 tcc_free(new_syms);
384
385 /* now we modify all the relocations */
386 for(i = 1; i < s1->nb_sections; i++) {
387 sr = s1->sections[i];
388 if (sr->sh_type == SHT_RELX && sr->link == s) {
389 for_each_elem(sr, 0, rel, ElfW_Rel) {
390 sym_index = ELFW(R_SYM)(rel->r_info);
391 type = ELFW(R_TYPE)(rel->r_info);
392 sym_index = old_to_new_syms[sym_index];
393 rel->r_info = ELFW(R_INFO)(sym_index, type);
394 }
395 }
396 }
397
398 tcc_free(old_to_new_syms);
399 }
400
401 /* relocate common symbols in the .bss section */
402 ST_FUNC void relocate_common_syms(void)
403 {
404 ElfW(Sym) *sym;
405 unsigned long offset, align;
406
407 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
408 if (sym->st_shndx == SHN_COMMON) {
409 /* align symbol */
410 align = sym->st_value;
411 offset = bss_section->data_offset;
412 offset = (offset + align - 1) & -align;
413 sym->st_value = offset;
414 sym->st_shndx = bss_section->sh_num;
415 offset += sym->st_size;
416 bss_section->data_offset = offset;
417 }
418 }
419 }
420
421 /* relocate symbol table, resolve undefined symbols if do_resolve is
422 true and output error if undefined symbol. */
423 ST_FUNC void relocate_syms(TCCState *s1, int do_resolve)
424 {
425 ElfW(Sym) *sym, *esym;
426 int sym_bind, sh_num, sym_index;
427 const char *name;
428
429 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
430 sh_num = sym->st_shndx;
431 if (sh_num == SHN_UNDEF) {
432 name = strtab_section->data + sym->st_name;
433 /* Use ld.so to resolve symbol for us (for tcc -run) */
434 if (do_resolve) {
435 #if defined TCC_IS_NATIVE && !defined _WIN32
436 void *addr;
437 name = symtab_section->link->data + sym->st_name;
438 addr = resolve_sym(s1, name);
439 if (addr) {
440 sym->st_value = (addr_t)addr;
441 goto found;
442 }
443 #endif
444 } else if (s1->dynsym) {
445 /* if dynamic symbol exist, then use it */
446 sym_index = find_elf_sym(s1->dynsym, name);
447 if (sym_index) {
448 esym = &((ElfW(Sym) *)s1->dynsym->data)[sym_index];
449 sym->st_value = esym->st_value;
450 goto found;
451 }
452 }
453 /* XXX: _fp_hw seems to be part of the ABI, so we ignore
454 it */
455 if (!strcmp(name, "_fp_hw"))
456 goto found;
457 /* only weak symbols are accepted to be undefined. Their
458 value is zero */
459 sym_bind = ELFW(ST_BIND)(sym->st_info);
460 if (sym_bind == STB_WEAK) {
461 sym->st_value = 0;
462 } else {
463 tcc_error_noabort("undefined symbol '%s'", name);
464 }
465 } else if (sh_num < SHN_LORESERVE) {
466 /* add section base */
467 sym->st_value += s1->sections[sym->st_shndx]->sh_addr;
468 }
469 found: ;
470 }
471 }
472
473 #ifdef TCC_HAS_RUNTIME_PLTGOT
474 #ifdef TCC_TARGET_X86_64
475 #define JMP_TABLE_ENTRY_SIZE 14
476 static addr_t add_jmp_table(TCCState *s1, addr_t val)
477 {
478 char *p = s1->runtime_plt_and_got + s1->runtime_plt_and_got_offset;
479 s1->runtime_plt_and_got_offset += JMP_TABLE_ENTRY_SIZE;
480 /* jmp *0x0(%rip) */
481 p[0] = 0xff;
482 p[1] = 0x25;
483 *(int *)(p + 2) = 0;
484 *(addr_t *)(p + 6) = val;
485 return (addr_t)p;
486 }
487
488 static addr_t add_got_table(TCCState *s1, addr_t val)
489 {
490 addr_t *p = (addr_t *)(s1->runtime_plt_and_got + s1->runtime_plt_and_got_offset);
491 s1->runtime_plt_and_got_offset += sizeof(addr_t);
492 *p = val;
493 return (addr_t)p;
494 }
495 #elif defined TCC_TARGET_ARM
496 #define JMP_TABLE_ENTRY_SIZE 8
497 static addr_t add_jmp_table(TCCState *s1, int val)
498 {
499 uint32_t *p = (uint32_t *)(s1->runtime_plt_and_got + s1->runtime_plt_and_got_offset);
500 s1->runtime_plt_and_got_offset += JMP_TABLE_ENTRY_SIZE;
501 /* ldr pc, [pc, #-4] */
502 p[0] = 0xE51FF004;
503 p[1] = val;
504 return (addr_t)p;
505 }
506 #endif
507 #endif /* def TCC_HAS_RUNTIME_PLTGOT */
508
509 /* relocate a given section (CPU dependent) by applying the relocations
510 in the associated relocation section */
511 ST_FUNC void relocate_section(TCCState *s1, Section *s)
512 {
513 Section *sr = s->reloc;
514 ElfW_Rel *rel;
515 ElfW(Sym) *sym;
516 int type, sym_index;
517 unsigned char *ptr;
518 addr_t val, addr;
519 #if defined TCC_TARGET_I386 || defined TCC_TARGET_X86_64
520 ElfW_Rel *qrel = (ElfW_Rel *) sr->data; /* ptr to next reloc entry reused */
521 int esym_index;
522 #endif
523
524 for_each_elem(sr, 0, rel, ElfW_Rel) {
525 ptr = s->data + rel->r_offset;
526
527 sym_index = ELFW(R_SYM)(rel->r_info);
528 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
529 val = sym->st_value;
530 #ifdef TCC_TARGET_X86_64
531 val += rel->r_addend;
532 #endif
533 type = ELFW(R_TYPE)(rel->r_info);
534 addr = s->sh_addr + rel->r_offset;
535
536 /* CPU specific */
537 switch(type) {
538 #if defined(TCC_TARGET_I386)
539 case R_386_32:
540 if (s1->output_type == TCC_OUTPUT_DLL) {
541 esym_index = s1->symtab_to_dynsym[sym_index];
542 qrel->r_offset = rel->r_offset;
543 if (esym_index) {
544 qrel->r_info = ELFW(R_INFO)(esym_index, R_386_32);
545 qrel++;
546 break;
547 } else {
548 qrel->r_info = ELFW(R_INFO)(0, R_386_RELATIVE);
549 qrel++;
550 }
551 }
552 *(int *)ptr += val;
553 break;
554 case R_386_PC32:
555 if (s1->output_type == TCC_OUTPUT_DLL) {
556 /* DLL relocation */
557 esym_index = s1->symtab_to_dynsym[sym_index];
558 if (esym_index) {
559 qrel->r_offset = rel->r_offset;
560 qrel->r_info = ELFW(R_INFO)(esym_index, R_386_PC32);
561 qrel++;
562 break;
563 }
564 }
565 *(int *)ptr += val - addr;
566 break;
567 case R_386_PLT32:
568 *(int *)ptr += val - addr;
569 break;
570 case R_386_GLOB_DAT:
571 case R_386_JMP_SLOT:
572 *(int *)ptr = val;
573 break;
574 case R_386_GOTPC:
575 *(int *)ptr += s1->got->sh_addr - addr;
576 break;
577 case R_386_GOTOFF:
578 *(int *)ptr += val - s1->got->sh_addr;
579 break;
580 case R_386_GOT32:
581 /* we load the got offset */
582 *(int *)ptr += s1->sym_attrs[sym_index].got_offset;
583 break;
584 case R_386_16:
585 if (s1->output_format != TCC_OUTPUT_FORMAT_BINARY) {
586 output_file:
587 tcc_error("can only produce 16-bit binary files");
588 }
589 *(short *)ptr += val;
590 break;
591 case R_386_PC16:
592 if (s1->output_format != TCC_OUTPUT_FORMAT_BINARY)
593 goto output_file;
594 *(short *)ptr += val - addr;
595 break;
596 #elif defined(TCC_TARGET_ARM)
597 case R_ARM_PC24:
598 case R_ARM_CALL:
599 case R_ARM_JUMP24:
600 case R_ARM_PLT32:
601 {
602 int x, is_thumb, is_call, h, blx_avail, is_bl, th_ko;
603 x = (*(int *) ptr) & 0xffffff;
604 (*(int *)ptr) &= 0xff000000;
605 if (x & 0x800000)
606 x -= 0x1000000;
607 x <<= 2;
608 blx_avail = (TCC_ARM_VERSION >= 5);
609 is_thumb = val & 1;
610 is_bl = (*(unsigned *) ptr) >> 24 == 0xeb;
611 is_call = (type == R_ARM_CALL || (type == R_ARM_PC24 && is_bl));
612 x += val - addr;
613 h = x & 2;
614 th_ko = (x & 3) && (!blx_avail || !is_call);
615 #ifdef TCC_HAS_RUNTIME_PLTGOT
616 if (s1->output_type == TCC_OUTPUT_MEMORY) {
617 if (th_ko || x >= 0x2000000 || x < -0x2000000) {
618 x += add_jmp_table(s1, val) - val; /* add veneer */
619 th_ko = (x & 3) && (!blx_avail || !is_call);
620 is_thumb = 0; /* Veneer uses ARM instructions */
621 }
622 }
623 #endif
624 if (th_ko || x >= 0x2000000 || x < -0x2000000)
625 tcc_error("can't relocate value at %x",addr);
626 x >>= 2;
627 x &= 0xffffff;
628 /* Only reached if blx is avail and it is a call */
629 if (is_thumb) {
630 x |= h << 24;
631 (*(int *)ptr) = 0xfa << 24; /* bl -> blx */
632 }
633 (*(int *) ptr) |= x;
634 }
635 break;
636 /* Since these relocations only concern Thumb-2 and blx instruction was
637 introduced before Thumb-2, we can assume blx is available and not
638 guard its use */
639 case R_ARM_THM_PC22:
640 case R_ARM_THM_JUMP24:
641 {
642 int x, hi, lo, s, j1, j2, i1, i2, imm10, imm11;
643 int to_thumb, is_call, to_plt, blx_bit = 1 << 12;
644 Section *plt;
645
646 /* weak reference */
647 if (sym->st_shndx == SHN_UNDEF &&
648 ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
649 break;
650
651 /* Get initial offset */
652 hi = (*(uint16_t *)ptr);
653 lo = (*(uint16_t *)(ptr+2));
654 s = (hi >> 10) & 1;
655 j1 = (lo >> 13) & 1;
656 j2 = (lo >> 11) & 1;
657 i1 = (j1 ^ s) ^ 1;
658 i2 = (j2 ^ s) ^ 1;
659 imm10 = hi & 0x3ff;
660 imm11 = lo & 0x7ff;
661 x = (s << 24) | (i1 << 23) | (i2 << 22) |
662 (imm10 << 12) | (imm11 << 1);
663 if (x & 0x01000000)
664 x -= 0x02000000;
665
666 /* Relocation infos */
667 to_thumb = val & 1;
668 plt = s1->plt;
669 to_plt = (val >= plt->sh_addr) &&
670 (val < plt->sh_addr + plt->data_offset);
671 is_call = (type == R_ARM_THM_PC22);
672
673 /* Compute final offset */
674 if (to_plt && !is_call) /* Point to 1st instr of Thumb stub */
675 x -= 4;
676 x += val - addr;
677 if (!to_thumb && is_call) {
678 blx_bit = 0; /* bl -> blx */
679 x = (x + 3) & -4; /* Compute offset from aligned PC */
680 }
681
682 /* Check that relocation is possible
683 * offset must not be out of range
684 * if target is to be entered in arm mode:
685 - bit 1 must not set
686 - instruction must be a call (bl) or a jump to PLT */
687 if (!to_thumb || x >= 0x1000000 || x < -0x1000000)
688 if (to_thumb || (val & 2) || (!is_call && !to_plt))
689 tcc_error("can't relocate value at %x",addr);
690
691 /* Compute and store final offset */
692 s = (x >> 24) & 1;
693 i1 = (x >> 23) & 1;
694 i2 = (x >> 22) & 1;
695 j1 = s ^ (i1 ^ 1);
696 j2 = s ^ (i2 ^ 1);
697 imm10 = (x >> 12) & 0x3ff;
698 imm11 = (x >> 1) & 0x7ff;
699 (*(uint16_t *)ptr) = (uint16_t) ((hi & 0xf800) |
700 (s << 10) | imm10);
701 (*(uint16_t *)(ptr+2)) = (uint16_t) ((lo & 0xc000) |
702 (j1 << 13) | blx_bit | (j2 << 11) |
703 imm11);
704 }
705 break;
706 case R_ARM_MOVT_ABS:
707 case R_ARM_MOVW_ABS_NC:
708 {
709 int x, imm4, imm12;
710 if (type == R_ARM_MOVT_ABS)
711 val >>= 16;
712 imm12 = val & 0xfff;
713 imm4 = (val >> 12) & 0xf;
714 x = (imm4 << 16) | imm12;
715 if (type == R_ARM_THM_MOVT_ABS)
716 *(int *)ptr |= x;
717 else
718 *(int *)ptr += x;
719 }
720 break;
721 case R_ARM_THM_MOVT_ABS:
722 case R_ARM_THM_MOVW_ABS_NC:
723 {
724 int x, i, imm4, imm3, imm8;
725 if (type == R_ARM_THM_MOVT_ABS)
726 val >>= 16;
727 imm8 = val & 0xff;
728 imm3 = (val >> 8) & 0x7;
729 i = (val >> 11) & 1;
730 imm4 = (val >> 12) & 0xf;
731 x = (imm3 << 28) | (imm8 << 16) | (i << 10) | imm4;
732 if (type == R_ARM_THM_MOVT_ABS)
733 *(int *)ptr |= x;
734 else
735 *(int *)ptr += x;
736 }
737 break;
738 case R_ARM_PREL31:
739 {
740 int x;
741 x = (*(int *)ptr) & 0x7fffffff;
742 (*(int *)ptr) &= 0x80000000;
743 x = (x * 2) / 2;
744 x += val - addr;
745 if((x^(x>>1))&0x40000000)
746 tcc_error("can't relocate value at %x",addr);
747 (*(int *)ptr) |= x & 0x7fffffff;
748 }
749 case R_ARM_ABS32:
750 *(int *)ptr += val;
751 break;
752 case R_ARM_REL32:
753 *(int *)ptr += val - addr;
754 break;
755 case R_ARM_GOTPC:
756 *(int *)ptr += s1->got->sh_addr - addr;
757 break;
758 case R_ARM_GOTOFF:
759 *(int *)ptr += val - s1->got->sh_addr;
760 break;
761 case R_ARM_GOT32:
762 /* we load the got offset */
763 *(int *)ptr += s1->sym_attrs[sym_index].got_offset;
764 break;
765 case R_ARM_COPY:
766 break;
767 case R_ARM_V4BX:
768 /* trade Thumb support for ARMv4 support */
769 if ((0x0ffffff0 & *(int*)ptr) == 0x012FFF10)
770 *(int*)ptr ^= 0xE12FFF10 ^ 0xE1A0F000; /* BX Rm -> MOV PC, Rm */
771 break;
772 default:
773 fprintf(stderr,"FIXME: handle reloc type %x at %x [%p] to %x\n",
774 type, (unsigned)addr, ptr, (unsigned)val);
775 break;
776 #elif defined(TCC_TARGET_C67)
777 case R_C60_32:
778 *(int *)ptr += val;
779 break;
780 case R_C60LO16:
781 {
782 uint32_t orig;
783
784 /* put the low 16 bits of the absolute address
785 add to what is already there */
786
787 orig = ((*(int *)(ptr )) >> 7) & 0xffff;
788 orig |= (((*(int *)(ptr+4)) >> 7) & 0xffff) << 16;
789
790 /* patch both at once - assumes always in pairs Low - High */
791
792 *(int *) ptr = (*(int *) ptr & (~(0xffff << 7)) ) | (((val+orig) & 0xffff) << 7);
793 *(int *)(ptr+4) = (*(int *)(ptr+4) & (~(0xffff << 7)) ) | ((((val+orig)>>16) & 0xffff) << 7);
794 }
795 break;
796 case R_C60HI16:
797 break;
798 default:
799 fprintf(stderr,"FIXME: handle reloc type %x at %x [%p] to %x\n",
800 type, (unsigned)addr, ptr, (unsigned)val);
801 break;
802 #elif defined(TCC_TARGET_X86_64)
803 case R_X86_64_64:
804 if (s1->output_type == TCC_OUTPUT_DLL) {
805 qrel->r_info = ELFW(R_INFO)(0, R_X86_64_RELATIVE);
806 qrel->r_addend = *(long long *)ptr + val;
807 qrel++;
808 }
809 *(long long *)ptr += val;
810 break;
811 case R_X86_64_32:
812 case R_X86_64_32S:
813 if (s1->output_type == TCC_OUTPUT_DLL) {
814 /* XXX: this logic may depend on TCC's codegen
815 now TCC uses R_X86_64_32 even for a 64bit pointer */
816 qrel->r_info = ELFW(R_INFO)(0, R_X86_64_RELATIVE);
817 qrel->r_addend = *(int *)ptr + val;
818 qrel++;
819 }
820 *(int *)ptr += val;
821 break;
822
823 case R_X86_64_PC32:
824 if (s1->output_type == TCC_OUTPUT_DLL) {
825 /* DLL relocation */
826 esym_index = s1->symtab_to_dynsym[sym_index];
827 if (esym_index) {
828 qrel->r_offset = rel->r_offset;
829 qrel->r_info = ELFW(R_INFO)(esym_index, R_X86_64_PC32);
830 qrel->r_addend = *(int *)ptr;
831 qrel++;
832 break;
833 }
834 }
835 /* fall through */
836 case R_X86_64_PLT32: {
837 long long diff;
838 diff = (long long)val - addr;
839 if (diff <= -2147483647 || diff > 2147483647) {
840 #ifdef TCC_HAS_RUNTIME_PLTGOT
841 /* XXX: naive support for over 32bit jump */
842 if (s1->output_type == TCC_OUTPUT_MEMORY) {
843 val = (add_jmp_table(s1, val - rel->r_addend) +
844 rel->r_addend);
845 diff = val - addr;
846 }
847 #endif
848 if (diff <= -2147483647 || diff > 2147483647) {
849 tcc_error("internal error: relocation failed");
850 }
851 }
852 *(int *)ptr += diff;
853 }
854 break;
855 case R_X86_64_GLOB_DAT:
856 case R_X86_64_JUMP_SLOT:
857 /* They don't need addend */
858 *(int *)ptr = val - rel->r_addend;
859 break;
860 case R_X86_64_GOTPCREL:
861 #ifdef TCC_HAS_RUNTIME_PLTGOT
862 if (s1->output_type == TCC_OUTPUT_MEMORY) {
863 val = add_got_table(s1, val - rel->r_addend) + rel->r_addend;
864 *(int *)ptr += val - addr;
865 break;
866 }
867 #endif
868 *(int *)ptr += (s1->got->sh_addr - addr +
869 s1->sym_attrs[sym_index].got_offset - 4);
870 break;
871 case R_X86_64_GOTTPOFF:
872 *(int *)ptr += val - s1->got->sh_addr;
873 break;
874 case R_X86_64_GOT32:
875 /* we load the got offset */
876 *(int *)ptr += s1->sym_attrs[sym_index].got_offset;
877 break;
878 #else
879 #error unsupported processor
880 #endif
881 }
882 }
883 /* if the relocation is allocated, we change its symbol table */
884 if (sr->sh_flags & SHF_ALLOC)
885 sr->link = s1->dynsym;
886 }
887
888 /* relocate relocation table in 'sr' */
889 static void relocate_rel(TCCState *s1, Section *sr)
890 {
891 Section *s;
892 ElfW_Rel *rel;
893
894 s = s1->sections[sr->sh_info];
895 for_each_elem(sr, 0, rel, ElfW_Rel)
896 rel->r_offset += s->sh_addr;
897 }
898
899 /* count the number of dynamic relocations so that we can reserve
900 their space */
901 static int prepare_dynamic_rel(TCCState *s1, Section *sr)
902 {
903 ElfW_Rel *rel;
904 int sym_index, esym_index, type, count;
905
906 count = 0;
907 for_each_elem(sr, 0, rel, ElfW_Rel) {
908 sym_index = ELFW(R_SYM)(rel->r_info);
909 type = ELFW(R_TYPE)(rel->r_info);
910 switch(type) {
911 #if defined(TCC_TARGET_I386)
912 case R_386_32:
913 #elif defined(TCC_TARGET_X86_64)
914 case R_X86_64_32:
915 case R_X86_64_32S:
916 case R_X86_64_64:
917 #endif
918 count++;
919 break;
920 #if defined(TCC_TARGET_I386)
921 case R_386_PC32:
922 #elif defined(TCC_TARGET_X86_64)
923 case R_X86_64_PC32:
924 #endif
925 esym_index = s1->symtab_to_dynsym[sym_index];
926 if (esym_index)
927 count++;
928 break;
929 default:
930 break;
931 }
932 }
933 if (count) {
934 /* allocate the section */
935 sr->sh_flags |= SHF_ALLOC;
936 sr->sh_size = count * sizeof(ElfW_Rel);
937 }
938 return count;
939 }
940
941 static struct sym_attr *alloc_sym_attr(TCCState *s1, int index)
942 {
943 int n;
944 struct sym_attr *tab;
945
946 if (index >= s1->nb_sym_attrs) {
947 /* find immediately bigger power of 2 and reallocate array */
948 n = 1;
949 while (index >= n)
950 n *= 2;
951 tab = tcc_realloc(s1->sym_attrs, n * sizeof(*s1->sym_attrs));
952 s1->sym_attrs = tab;
953 memset(s1->sym_attrs + s1->nb_sym_attrs, 0,
954 (n - s1->nb_sym_attrs) * sizeof(*s1->sym_attrs));
955 s1->nb_sym_attrs = n;
956 }
957 return &s1->sym_attrs[index];
958 }
959
960 /* XXX: suppress that */
961 static void put32(unsigned char *p, uint32_t val)
962 {
963 p[0] = val;
964 p[1] = val >> 8;
965 p[2] = val >> 16;
966 p[3] = val >> 24;
967 }
968
969 #if defined(TCC_TARGET_I386) || defined(TCC_TARGET_ARM) || \
970 defined(TCC_TARGET_X86_64)
971 static uint32_t get32(unsigned char *p)
972 {
973 return p[0] | (p[1] << 8) | (p[2] << 16) | (p[3] << 24);
974 }
975 #endif
976
977 static void build_got(TCCState *s1)
978 {
979 unsigned char *ptr;
980
981 /* if no got, then create it */
982 s1->got = new_section(s1, ".got", SHT_PROGBITS, SHF_ALLOC | SHF_WRITE);
983 s1->got->sh_entsize = 4;
984 add_elf_sym(symtab_section, 0, 4, ELFW(ST_INFO)(STB_GLOBAL, STT_OBJECT),
985 0, s1->got->sh_num, "_GLOBAL_OFFSET_TABLE_");
986 ptr = section_ptr_add(s1->got, 3 * PTR_SIZE);
987 #if PTR_SIZE == 4
988 /* keep space for _DYNAMIC pointer, if present */
989 put32(ptr, 0);
990 /* two dummy got entries */
991 put32(ptr + 4, 0);
992 put32(ptr + 8, 0);
993 #else
994 /* keep space for _DYNAMIC pointer, if present */
995 put32(ptr, 0);
996 put32(ptr + 4, 0);
997 /* two dummy got entries */
998 put32(ptr + 8, 0);
999 put32(ptr + 12, 0);
1000 put32(ptr + 16, 0);
1001 put32(ptr + 20, 0);
1002 #endif
1003 }
1004
1005 /* put a got entry corresponding to a symbol in symtab_section. 'size'
1006 and 'info' can be modifed if more precise info comes from the DLL */
1007 static void put_got_entry(TCCState *s1,
1008 int reloc_type, unsigned long size, int info,
1009 int sym_index)
1010 {
1011 int index;
1012 const char *name;
1013 ElfW(Sym) *sym;
1014 unsigned long offset;
1015 int *ptr;
1016
1017 if (!s1->got)
1018 build_got(s1);
1019
1020 /* if a got entry already exists for that symbol, no need to add one */
1021 if (sym_index < s1->nb_sym_attrs &&
1022 s1->sym_attrs[sym_index].got_offset)
1023 return;
1024
1025 alloc_sym_attr(s1, sym_index)->got_offset = s1->got->data_offset;
1026
1027 if (s1->dynsym) {
1028 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1029 name = symtab_section->link->data + sym->st_name;
1030 offset = sym->st_value;
1031 #if defined(TCC_TARGET_I386) || defined(TCC_TARGET_X86_64)
1032 if (reloc_type ==
1033 #ifdef TCC_TARGET_X86_64
1034 R_X86_64_JUMP_SLOT
1035 #else
1036 R_386_JMP_SLOT
1037 #endif
1038 ) {
1039 Section *plt;
1040 uint8_t *p;
1041 int modrm;
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 p = section_ptr_add(plt, 16);
1067 p[0] = 0xff; /* jmp *(got + x) */
1068 p[1] = modrm;
1069 put32(p + 2, s1->got->data_offset);
1070 p[6] = 0x68; /* push $xxx */
1071 put32(p + 7, (plt->data_offset - 32) >> 1);
1072 p[11] = 0xe9; /* jmp plt_start */
1073 put32(p + 12, -(plt->data_offset));
1074
1075 /* the symbol is modified so that it will be relocated to
1076 the PLT */
1077 #if !defined(TCC_OUTPUT_DLL_WITH_PLT)
1078 if (s1->output_type == TCC_OUTPUT_EXE)
1079 #endif
1080 offset = plt->data_offset - 16;
1081 }
1082 #elif defined(TCC_TARGET_ARM)
1083 if (reloc_type == R_ARM_JUMP_SLOT) {
1084 Section *plt;
1085 uint8_t *p;
1086
1087 /* if we build a DLL, we add a %ebx offset */
1088 if (s1->output_type == TCC_OUTPUT_DLL)
1089 tcc_error("DLLs unimplemented!");
1090
1091 /* add a PLT entry */
1092 plt = s1->plt;
1093 if (plt->data_offset == 0) {
1094 /* first plt entry */
1095 p = section_ptr_add(plt, 16);
1096 put32(p, 0xe52de004); /* push {lr} */
1097 put32(p+4, 0xe59fe010); /* ldr lr, [pc, #16] */
1098 put32(p+8, 0xe08fe00e); /* add lr, pc, lr */
1099 put32(p+12, 0xe5bef008); /* ldr pc, [lr, #8]! */
1100 }
1101
1102 if (s1->sym_attrs[sym_index].plt_thumb_stub) {
1103 p = section_ptr_add(plt, 20);
1104 put32(p, 0x4778); /* bx pc */
1105 put32(p+2, 0x46c0); /* nop */
1106 p += 4;
1107 } else
1108 p = section_ptr_add(plt, 16);
1109 put32(p, 0xe59fc004); /* ldr ip, [pc, #4] ; GOT entry offset */
1110 put32(p+4, 0xe08fc00c); /* add ip, pc, ip ; addr of GOT entry */
1111 put32(p+8, 0xe59cf000); /* ldr pc, [ip] ; jump to GOT entry */
1112 put32(p+12, s1->got->data_offset); /* GOT entry off once patched */
1113
1114 /* the symbol is modified so that it will be relocated to
1115 the PLT */
1116 if (s1->output_type == TCC_OUTPUT_EXE)
1117 offset = plt->data_offset - 16;
1118 }
1119 #elif defined(TCC_TARGET_C67)
1120 tcc_error("C67 got not implemented");
1121 #else
1122 #error unsupported CPU
1123 #endif
1124 index = put_elf_sym(s1->dynsym, offset,
1125 size, info, 0, sym->st_shndx, name);
1126 /* put a got entry */
1127 put_elf_reloc(s1->dynsym, s1->got,
1128 s1->got->data_offset,
1129 reloc_type, index);
1130 }
1131 ptr = section_ptr_add(s1->got, PTR_SIZE);
1132 *ptr = 0;
1133 }
1134
1135 /* build GOT and PLT entries */
1136 ST_FUNC void build_got_entries(TCCState *s1)
1137 {
1138 Section *s;
1139 ElfW_Rel *rel;
1140 ElfW(Sym) *sym;
1141 int i, type, reloc_type, sym_index;
1142
1143 for(i = 1; i < s1->nb_sections; i++) {
1144 s = s1->sections[i];
1145 if (s->sh_type != SHT_RELX)
1146 continue;
1147 /* no need to handle got relocations */
1148 if (s->link != symtab_section)
1149 continue;
1150 for_each_elem(s, 0, rel, ElfW_Rel) {
1151 type = ELFW(R_TYPE)(rel->r_info);
1152 switch(type) {
1153 #if defined(TCC_TARGET_I386)
1154 case R_386_GOT32:
1155 case R_386_GOTOFF:
1156 case R_386_GOTPC:
1157 case R_386_PLT32:
1158 if (!s1->got)
1159 build_got(s1);
1160 if (type == R_386_GOT32 || type == R_386_PLT32) {
1161 sym_index = ELFW(R_SYM)(rel->r_info);
1162 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1163 /* look at the symbol got offset. If none, then add one */
1164 if (type == R_386_GOT32)
1165 reloc_type = R_386_GLOB_DAT;
1166 else
1167 reloc_type = R_386_JMP_SLOT;
1168 put_got_entry(s1, reloc_type, sym->st_size, sym->st_info,
1169 sym_index);
1170 }
1171 break;
1172 #elif defined(TCC_TARGET_ARM)
1173 case R_ARM_GOT32:
1174 case R_ARM_GOTOFF:
1175 case R_ARM_GOTPC:
1176 case R_ARM_PLT32:
1177 if (!s1->got)
1178 build_got(s1);
1179 if (type == R_ARM_GOT32 || type == R_ARM_PLT32) {
1180 sym_index = ELFW(R_SYM)(rel->r_info);
1181 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1182 /* look at the symbol got offset. If none, then add one */
1183 if (type == R_ARM_GOT32)
1184 reloc_type = R_ARM_GLOB_DAT;
1185 else
1186 reloc_type = R_ARM_JUMP_SLOT;
1187 put_got_entry(s1, reloc_type, sym->st_size, sym->st_info,
1188 sym_index);
1189 }
1190 break;
1191 case R_ARM_THM_JUMP24:
1192 sym_index = ELFW(R_SYM)(rel->r_info);
1193 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1194 /* We are relocating a jump from thumb code to arm code */
1195 if (sym->st_shndx != SHN_UNDEF && !(sym->st_value & 1)) {
1196 int index;
1197 uint8_t *p;
1198 char *name, buf[1024];
1199 Section *text_section;
1200
1201 name = symtab_section->link->data + sym->st_name;
1202 text_section = s1->sections[sym->st_shndx];
1203 /* Modify reloc to target a thumb stub to switch to ARM */
1204 snprintf(buf, sizeof(buf), "%s_from_thumb", name);
1205 index = put_elf_sym(symtab_section,
1206 text_section->data_offset + 1,
1207 sym->st_size, sym->st_info, 0,
1208 sym->st_shndx, buf);
1209 rel->r_info = ELFW(R_INFO)(index, type);
1210 /* Create a thumb stub fonction to switch to ARM mode */
1211 put_elf_reloc(symtab_section, text_section,
1212 text_section->data_offset, R_ARM_JUMP24,
1213 sym_index);
1214 p = section_ptr_add(text_section, 8);
1215 put32(p, 0x4778); /* bx pc */
1216 put32(p+2, 0x46c0); /* nop */
1217 put32(p+4, 0xeafffffe); /* b $sym */
1218 }
1219 #elif defined(TCC_TARGET_C67)
1220 case R_C60_GOT32:
1221 case R_C60_GOTOFF:
1222 case R_C60_GOTPC:
1223 case R_C60_PLT32:
1224 if (!s1->got)
1225 build_got(s1);
1226 if (type == R_C60_GOT32 || type == R_C60_PLT32) {
1227 sym_index = ELFW(R_SYM)(rel->r_info);
1228 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1229 /* look at the symbol got offset. If none, then add one */
1230 if (type == R_C60_GOT32)
1231 reloc_type = R_C60_GLOB_DAT;
1232 else
1233 reloc_type = R_C60_JMP_SLOT;
1234 put_got_entry(s1, reloc_type, sym->st_size, sym->st_info,
1235 sym_index);
1236 }
1237 break;
1238 #elif defined(TCC_TARGET_X86_64)
1239 case R_X86_64_GOT32:
1240 case R_X86_64_GOTTPOFF:
1241 case R_X86_64_GOTPCREL:
1242 case R_X86_64_PLT32:
1243 if (!s1->got)
1244 build_got(s1);
1245 if (type == R_X86_64_GOT32 || type == R_X86_64_GOTPCREL ||
1246 type == R_X86_64_PLT32) {
1247 sym_index = ELFW(R_SYM)(rel->r_info);
1248 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1249 /* look at the symbol got offset. If none, then add one */
1250 if (type == R_X86_64_GOT32 || type == R_X86_64_GOTPCREL)
1251 reloc_type = R_X86_64_GLOB_DAT;
1252 else
1253 reloc_type = R_X86_64_JUMP_SLOT;
1254 put_got_entry(s1, reloc_type, sym->st_size, sym->st_info,
1255 sym_index);
1256 }
1257 break;
1258 #else
1259 #error unsupported CPU
1260 #endif
1261 default:
1262 break;
1263 }
1264 }
1265 }
1266 }
1267
1268 ST_FUNC Section *new_symtab(TCCState *s1,
1269 const char *symtab_name, int sh_type, int sh_flags,
1270 const char *strtab_name,
1271 const char *hash_name, int hash_sh_flags)
1272 {
1273 Section *symtab, *strtab, *hash;
1274 int *ptr, nb_buckets;
1275
1276 symtab = new_section(s1, symtab_name, sh_type, sh_flags);
1277 symtab->sh_entsize = sizeof(ElfW(Sym));
1278 strtab = new_section(s1, strtab_name, SHT_STRTAB, sh_flags);
1279 put_elf_str(strtab, "");
1280 symtab->link = strtab;
1281 put_elf_sym(symtab, 0, 0, 0, 0, 0, NULL);
1282
1283 nb_buckets = 1;
1284
1285 hash = new_section(s1, hash_name, SHT_HASH, hash_sh_flags);
1286 hash->sh_entsize = sizeof(int);
1287 symtab->hash = hash;
1288 hash->link = symtab;
1289
1290 ptr = section_ptr_add(hash, (2 + nb_buckets + 1) * sizeof(int));
1291 ptr[0] = nb_buckets;
1292 ptr[1] = 1;
1293 memset(ptr + 2, 0, (nb_buckets + 1) * sizeof(int));
1294 return symtab;
1295 }
1296
1297 /* put dynamic tag */
1298 static void put_dt(Section *dynamic, int dt, addr_t val)
1299 {
1300 ElfW(Dyn) *dyn;
1301 dyn = section_ptr_add(dynamic, sizeof(ElfW(Dyn)));
1302 dyn->d_tag = dt;
1303 dyn->d_un.d_val = val;
1304 }
1305
1306 static void add_init_array_defines(TCCState *s1, const char *section_name)
1307 {
1308 Section *s;
1309 long end_offset;
1310 char sym_start[1024];
1311 char sym_end[1024];
1312
1313 snprintf(sym_start, sizeof(sym_start), "__%s_start", section_name + 1);
1314 snprintf(sym_end, sizeof(sym_end), "__%s_end", section_name + 1);
1315
1316 s = find_section(s1, section_name);
1317 if (!s) {
1318 end_offset = 0;
1319 s = data_section;
1320 } else {
1321 end_offset = s->data_offset;
1322 }
1323
1324 add_elf_sym(symtab_section,
1325 0, 0,
1326 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1327 s->sh_num, sym_start);
1328 add_elf_sym(symtab_section,
1329 end_offset, 0,
1330 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1331 s->sh_num, sym_end);
1332 }
1333
1334 ST_FUNC void tcc_add_bcheck(TCCState *s1)
1335 {
1336 #ifdef CONFIG_TCC_BCHECK
1337 unsigned long *ptr;
1338 Section *init_section;
1339 unsigned char *pinit;
1340 int sym_index;
1341
1342 if (0 == s1->do_bounds_check)
1343 return;
1344
1345 /* XXX: add an object file to do that */
1346 ptr = section_ptr_add(bounds_section, sizeof(unsigned long));
1347 *ptr = 0;
1348 add_elf_sym(symtab_section, 0, 0,
1349 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1350 bounds_section->sh_num, "__bounds_start");
1351 #ifdef TCC_TARGET_I386
1352 if (s1->output_type != TCC_OUTPUT_MEMORY) {
1353 /* add 'call __bound_init()' in .init section */
1354 init_section = find_section(s1, ".init");
1355 pinit = section_ptr_add(init_section, 5);
1356 pinit[0] = 0xe8;
1357 put32(pinit + 1, -4);
1358 sym_index = find_elf_sym(symtab_section, "__bound_init");
1359 put_elf_reloc(symtab_section, init_section,
1360 init_section->data_offset - 4, R_386_PC32, sym_index);
1361 }
1362 #endif
1363 #endif
1364 }
1365
1366 static inline int tcc_add_support(TCCState *s1, const char *filename)
1367 {
1368 char buf[1024];
1369 snprintf(buf, sizeof(buf), "%s/%s", s1->tcc_lib_path, filename);
1370 return tcc_add_file(s1, buf);
1371 }
1372
1373 /* add tcc runtime libraries */
1374 ST_FUNC void tcc_add_runtime(TCCState *s1)
1375 {
1376 tcc_add_bcheck(s1);
1377
1378 /* add libc */
1379 if (!s1->nostdlib) {
1380 tcc_add_library(s1, "c");
1381 #ifdef CONFIG_USE_LIBGCC
1382 if (!s1->static_link)
1383 tcc_add_file(s1, TCC_LIBGCC);
1384 else
1385 tcc_add_support(s1, "libtcc1.a");
1386 #else
1387 tcc_add_support(s1, "libtcc1.a");
1388 #endif
1389 /* add crt end if not memory output */
1390 if (s1->output_type != TCC_OUTPUT_MEMORY)
1391 tcc_add_crt(s1, "crtn.o");
1392 }
1393 }
1394
1395 /* add various standard linker symbols (must be done after the
1396 sections are filled (for example after allocating common
1397 symbols)) */
1398 ST_FUNC void tcc_add_linker_symbols(TCCState *s1)
1399 {
1400 char buf[1024];
1401 int i;
1402 Section *s;
1403
1404 add_elf_sym(symtab_section,
1405 text_section->data_offset, 0,
1406 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1407 text_section->sh_num, "_etext");
1408 add_elf_sym(symtab_section,
1409 data_section->data_offset, 0,
1410 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1411 data_section->sh_num, "_edata");
1412 add_elf_sym(symtab_section,
1413 bss_section->data_offset, 0,
1414 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1415 bss_section->sh_num, "_end");
1416 /* horrible new standard ldscript defines */
1417 add_init_array_defines(s1, ".preinit_array");
1418 add_init_array_defines(s1, ".init_array");
1419 add_init_array_defines(s1, ".fini_array");
1420
1421 /* add start and stop symbols for sections whose name can be
1422 expressed in C */
1423 for(i = 1; i < s1->nb_sections; i++) {
1424 s = s1->sections[i];
1425 if (s->sh_type == SHT_PROGBITS &&
1426 (s->sh_flags & SHF_ALLOC)) {
1427 const char *p;
1428 int ch;
1429
1430 /* check if section name can be expressed in C */
1431 p = s->name;
1432 for(;;) {
1433 ch = *p;
1434 if (!ch)
1435 break;
1436 if (!isid(ch) && !isnum(ch))
1437 goto next_sec;
1438 p++;
1439 }
1440 snprintf(buf, sizeof(buf), "__start_%s", s->name);
1441 add_elf_sym(symtab_section,
1442 0, 0,
1443 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1444 s->sh_num, buf);
1445 snprintf(buf, sizeof(buf), "__stop_%s", s->name);
1446 add_elf_sym(symtab_section,
1447 s->data_offset, 0,
1448 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1449 s->sh_num, buf);
1450 }
1451 next_sec: ;
1452 }
1453 }
1454
1455 static void tcc_output_binary(TCCState *s1, FILE *f,
1456 const int *sec_order)
1457 {
1458 Section *s;
1459 int i, offset, size;
1460
1461 offset = 0;
1462 for(i=1;i<s1->nb_sections;i++) {
1463 s = s1->sections[sec_order[i]];
1464 if (s->sh_type != SHT_NOBITS &&
1465 (s->sh_flags & SHF_ALLOC)) {
1466 while (offset < s->sh_offset) {
1467 fputc(0, f);
1468 offset++;
1469 }
1470 size = s->sh_size;
1471 fwrite(s->data, 1, size, f);
1472 offset += size;
1473 }
1474 }
1475 }
1476
1477 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1478 #define HAVE_PHDR 1
1479 #define EXTRA_RELITEMS 14
1480
1481 /* move the relocation value from .dynsym to .got */
1482 void patch_dynsym_undef(TCCState *s1, Section *s)
1483 {
1484 uint32_t *gotd = (void *)s1->got->data;
1485 ElfW(Sym) *sym;
1486
1487 gotd += 3; /* dummy entries in .got */
1488 /* relocate symbols in .dynsym */
1489 for_each_elem(s, 1, sym, ElfW(Sym)) {
1490 if (sym->st_shndx == SHN_UNDEF) {
1491 *gotd++ = sym->st_value + 6; /* XXX 6 is magic ? */
1492 sym->st_value = 0;
1493 }
1494 }
1495 }
1496 #else
1497 #define HAVE_PHDR 0
1498 #define EXTRA_RELITEMS 9
1499
1500 /* zero plt offsets of weak symbols in .dynsym */
1501 void patch_dynsym_undef(TCCState *s1, Section *s)
1502 {
1503 ElfW(Sym) *sym;
1504
1505 for_each_elem(s, 1, sym, ElfW(Sym))
1506 if (sym->st_shndx == SHN_UNDEF && ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
1507 sym->st_value = 0;
1508 }
1509 #endif
1510
1511 ST_FUNC void fill_got_entry(TCCState *s1, ElfW_Rel *rel)
1512 {
1513 int sym_index = ELFW(R_SYM) (rel->r_info);
1514 ElfW(Sym) *sym = &((ElfW(Sym) *) symtab_section->data)[sym_index];
1515 unsigned long offset;
1516
1517 if (sym_index >= s1->nb_sym_attrs)
1518 return;
1519 offset = s1->sym_attrs[sym_index].got_offset;
1520 section_reserve(s1->got, offset + PTR_SIZE);
1521 #ifdef TCC_TARGET_X86_64
1522 /* only works for x86-64 */
1523 put32(s1->got->data + offset + 4, sym->st_value >> 32);
1524 #endif
1525 put32(s1->got->data + offset, sym->st_value & 0xffffffff);
1526 }
1527
1528 /* Perform relocation to GOT or PLT entries */
1529 ST_FUNC void fill_got(TCCState *s1)
1530 {
1531 Section *s;
1532 ElfW_Rel *rel;
1533 int i;
1534
1535 for(i = 1; i < s1->nb_sections; i++) {
1536 s = s1->sections[i];
1537 if (s->sh_type != SHT_RELX)
1538 continue;
1539 /* no need to handle got relocations */
1540 if (s->link != symtab_section)
1541 continue;
1542 for_each_elem(s, 0, rel, ElfW_Rel) {
1543 switch (ELFW(R_TYPE) (rel->r_info)) {
1544 case R_X86_64_GOT32:
1545 case R_X86_64_GOTPCREL:
1546 case R_X86_64_PLT32:
1547 fill_got_entry(s1, rel);
1548 break;
1549 }
1550 }
1551 }
1552 }
1553
1554 /* Bind symbols of executable: resolve undefined symbols from exported symbols
1555 in shared libraries and export non local defined symbols to shared libraries
1556 if -rdynamic switch was given on command line */
1557 static void bind_exe_dynsyms(TCCState *s1)
1558 {
1559 const char *name;
1560 int sym_index, index;
1561 ElfW(Sym) *sym, *esym;
1562 int type;
1563
1564 /* Resolve undefined symbols from dynamic symbols. When there is a match:
1565 - if STT_FUNC or STT_GNU_IFUNC symbol -> add it in PLT
1566 - if STT_OBJECT symbol -> add it in .bss section with suitable reloc */
1567 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
1568 if (sym->st_shndx == SHN_UNDEF) {
1569 name = symtab_section->link->data + sym->st_name;
1570 sym_index = find_elf_sym(s1->dynsymtab_section, name);
1571 if (sym_index) {
1572 esym = &((ElfW(Sym) *)s1->dynsymtab_section->data)[sym_index];
1573 type = ELFW(ST_TYPE)(esym->st_info);
1574 if ((type == STT_FUNC) || (type == STT_GNU_IFUNC)) {
1575 /* Indirect functions shall have STT_FUNC type in executable
1576 * dynsym section. Indeed, a dlsym call following a lazy
1577 * resolution would pick the symbol value from the
1578 * executable dynsym entry which would contain the address
1579 * of the function wanted by the caller of dlsym instead of
1580 * the address of the function that would return that
1581 * address */
1582 put_got_entry(s1, R_JMP_SLOT, esym->st_size,
1583 ELFW(ST_INFO)(STB_GLOBAL,STT_FUNC),
1584 sym - (ElfW(Sym) *)symtab_section->data);
1585 } else if (type == STT_OBJECT) {
1586 unsigned long offset;
1587 ElfW(Sym) *dynsym;
1588 offset = bss_section->data_offset;
1589 /* XXX: which alignment ? */
1590 offset = (offset + 16 - 1) & -16;
1591 index = put_elf_sym(s1->dynsym, offset, esym->st_size,
1592 esym->st_info, 0, bss_section->sh_num,
1593 name);
1594 /* Ensure R_COPY works for weak symbol aliases */
1595 if (ELFW(ST_BIND)(esym->st_info) == STB_WEAK) {
1596 for_each_elem(s1->dynsymtab_section, 1, dynsym, ElfW(Sym)) {
1597 if ((dynsym->st_value == esym->st_value)
1598 && (ELFW(ST_BIND)(dynsym->st_info) == STB_GLOBAL)) {
1599 char *dynname = s1->dynsymtab_section->link->data
1600 + dynsym->st_name;
1601 put_elf_sym(s1->dynsym, offset, dynsym->st_size,
1602 dynsym->st_info, 0,
1603 bss_section->sh_num, dynname);
1604 break;
1605 }
1606 }
1607 }
1608 put_elf_reloc(s1->dynsym, bss_section,
1609 offset, R_COPY, index);
1610 offset += esym->st_size;
1611 bss_section->data_offset = offset;
1612 }
1613 } else {
1614 /* STB_WEAK undefined symbols are accepted */
1615 /* XXX: _fp_hw seems to be part of the ABI, so we ignore it */
1616 if (ELFW(ST_BIND)(sym->st_info) == STB_WEAK ||
1617 !strcmp(name, "_fp_hw")) {
1618 } else {
1619 tcc_error_noabort("undefined symbol '%s'", name);
1620 }
1621 }
1622 } else if (s1->rdynamic && ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
1623 /* if -rdynamic option, then export all non local symbols */
1624 name = symtab_section->link->data + sym->st_name;
1625 put_elf_sym(s1->dynsym, sym->st_value, sym->st_size, sym->st_info,
1626 0, sym->st_shndx, name);
1627 }
1628 }
1629 }
1630
1631 /* Bind symbols of libraries: export non local symbols of executable that
1632 resolve undefined symbols of shared libraries */
1633 static void bind_libs_dynsyms(TCCState *s1)
1634 {
1635 const char *name;
1636 int sym_index;
1637 ElfW(Sym) *sym, *esym;
1638
1639 /* now look at unresolved dynamic symbols and export
1640 corresponding symbol */
1641 for_each_elem(s1->dynsymtab_section, 1, esym, ElfW(Sym)) {
1642 if (esym->st_shndx == SHN_UNDEF) {
1643 name = s1->dynsymtab_section->link->data + esym->st_name;
1644 sym_index = find_elf_sym(symtab_section, name);
1645 if (sym_index) {
1646 /* XXX: avoid adding a symbol if already present because of
1647 -rdynamic ? */
1648 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1649 put_elf_sym(s1->dynsym, sym->st_value, sym->st_size,
1650 sym->st_info, 0, sym->st_shndx, name);
1651 } else {
1652 /* weak symbols can stay undefined */
1653 if (ELFW(ST_BIND)(esym->st_info) != STB_WEAK)
1654 tcc_warning("undefined dynamic symbol '%s'", name);
1655 }
1656 }
1657 }
1658 }
1659
1660 /* Export all non local symbols (for shared libraries) */
1661 static void export_global_syms(TCCState *s1)
1662 {
1663 int nb_syms, dynindex, index;
1664 const char *name;
1665 ElfW(Sym) *sym;
1666
1667 nb_syms = symtab_section->data_offset / sizeof(ElfW(Sym));
1668 s1->symtab_to_dynsym = tcc_mallocz(sizeof(int) * nb_syms);
1669 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
1670 if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
1671 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
1672 int type = ELFW(ST_TYPE)(sym->st_info);
1673 if ((type == STT_FUNC || type == STT_GNU_IFUNC)
1674 && sym->st_shndx == SHN_UNDEF) {
1675 int visibility = ELFW(ST_BIND)(sym->st_info);
1676 put_got_entry(s1, R_JMP_SLOT, sym->st_size,
1677 ELFW(ST_INFO)(visibility, STT_FUNC),
1678 sym - (ElfW(Sym) *) symtab_section->data);
1679 } else if (type == STT_OBJECT) {
1680 put_got_entry(s1, R_X86_64_GLOB_DAT, sym->st_size, sym->st_info,
1681 sym - (ElfW(Sym) *) symtab_section->data);
1682 } else
1683 #endif
1684 {
1685 name = symtab_section->link->data + sym->st_name;
1686 dynindex = put_elf_sym(s1->dynsym, sym->st_value, sym->st_size,
1687 sym->st_info, 0, sym->st_shndx, name);
1688 index = sym - (ElfW(Sym) *) symtab_section->data;
1689 s1->symtab_to_dynsym[index] = dynindex;
1690 }
1691 }
1692 }
1693 }
1694
1695 /* relocate the PLT: compute addresses and offsets in the PLT now that final
1696 address for PLT and GOT are known (see fill_program_header) */
1697 static void relocate_plt(TCCState *s1)
1698 {
1699 uint8_t *p, *p_end;
1700
1701 p = s1->plt->data;
1702 p_end = p + s1->plt->data_offset;
1703 if (p < p_end) {
1704 #if defined(TCC_TARGET_I386)
1705 put32(p + 2, get32(p + 2) + s1->got->sh_addr);
1706 put32(p + 8, get32(p + 8) + s1->got->sh_addr);
1707 p += 16;
1708 while (p < p_end) {
1709 put32(p + 2, get32(p + 2) + s1->got->sh_addr);
1710 p += 16;
1711 }
1712 #elif defined(TCC_TARGET_X86_64)
1713 int x = s1->got->sh_addr - s1->plt->sh_addr - 6;
1714 put32(p + 2, get32(p + 2) + x);
1715 put32(p + 8, get32(p + 8) + x - 6);
1716 p += 16;
1717 while (p < p_end) {
1718 put32(p + 2, get32(p + 2) + x + s1->plt->data - p);
1719 p += 16;
1720 }
1721 #elif defined(TCC_TARGET_ARM)
1722 int x;
1723 x=s1->got->sh_addr - s1->plt->sh_addr - 12;
1724 p += 16;
1725 while (p < p_end) {
1726 if (get32(p) == 0x46c04778) /* PLT Thumb stub present */
1727 p += 4;
1728 put32(p + 12, x + get32(p + 12) + s1->plt->data - p);
1729 p += 16;
1730 }
1731 #elif defined(TCC_TARGET_C67)
1732 /* XXX: TODO */
1733 #else
1734 #error unsupported CPU
1735 #endif
1736 }
1737 }
1738
1739 /* Allocate strings for section names and decide if an unallocated section
1740 should be output.
1741
1742 NOTE: the strsec section comes last, so its size is also correct ! */
1743 static void alloc_sec_names(TCCState *s1, int file_type, Section *strsec)
1744 {
1745 int i;
1746 Section *s;
1747
1748 /* Allocate strings for section names */
1749 for(i = 1; i < s1->nb_sections; i++) {
1750 s = s1->sections[i];
1751 s->sh_name = put_elf_str(strsec, s->name);
1752 /* when generating a DLL, we include relocations but we may
1753 patch them */
1754 if (file_type == TCC_OUTPUT_DLL &&
1755 s->sh_type == SHT_RELX &&
1756 !(s->sh_flags & SHF_ALLOC)) {
1757 /* gr: avoid bogus relocs for empty (debug) sections */
1758 if (s1->sections[s->sh_info]->sh_flags & SHF_ALLOC)
1759 prepare_dynamic_rel(s1, s);
1760 else if (s1->do_debug)
1761 s->sh_size = s->data_offset;
1762 } else if (s1->do_debug ||
1763 file_type == TCC_OUTPUT_OBJ ||
1764 (s->sh_flags & SHF_ALLOC) ||
1765 i == (s1->nb_sections - 1)) {
1766 /* we output all sections if debug or object file */
1767 s->sh_size = s->data_offset;
1768 }
1769 }
1770 }
1771
1772 /* Info to be copied in dynamic section */
1773 struct dyn_inf {
1774 Section *dynamic;
1775 Section *dynstr;
1776 unsigned long dyn_rel_off;
1777 addr_t rel_addr;
1778 addr_t rel_size;
1779 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1780 addr_t bss_addr;
1781 addr_t bss_size;
1782 #endif
1783 };
1784
1785 /* Assign sections to segments and decide how are sections laid out when loaded
1786 in memory. This function also fills corresponding program headers. */
1787 static int layout_sections(TCCState *s1, ElfW(Phdr) *phdr, int phnum,
1788 Section *interp, struct dyn_inf *dyninf,
1789 int *sec_order)
1790 {
1791 int i, j, k, file_type, sh_order_index, file_offset;
1792 long long tmp;
1793 addr_t addr;
1794 ElfW(Phdr) *ph;
1795 Section *s;
1796
1797 file_type = s1->output_type;
1798 sh_order_index = 1;
1799 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF)
1800 file_offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr));
1801 else
1802 file_offset = 0;
1803
1804 if (phnum > 0) {
1805 if (s1->has_text_addr) {
1806 int a_offset, p_offset;
1807 addr = s1->text_addr;
1808 /* we ensure that (addr % ELF_PAGE_SIZE) == file_offset %
1809 ELF_PAGE_SIZE */
1810 a_offset = (int) (addr & (s1->section_align - 1));
1811 p_offset = file_offset & (s1->section_align - 1);
1812 if (a_offset < p_offset)
1813 a_offset += s1->section_align;
1814 file_offset += (a_offset - p_offset);
1815 } else {
1816 if (file_type == TCC_OUTPUT_DLL)
1817 addr = 0;
1818 else
1819 addr = ELF_START_ADDR;
1820 /* compute address after headers */
1821 addr += (file_offset & (s1->section_align - 1));
1822 }
1823
1824 ph = &phdr[0];
1825 /* Leave one program headers for the program interpreter and one for
1826 the program header table itself if needed. These are done later as
1827 they require section layout to be done first. */
1828 if (interp)
1829 ph += 1 + HAVE_PHDR;
1830
1831 /* dynamic relocation table information, for .dynamic section */
1832 dyninf->rel_addr = dyninf->rel_size = 0;
1833 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1834 dyninf->bss_addr = dyninf->bss_size = 0;
1835 #endif
1836
1837 for(j = 0; j < 2; j++) {
1838 ph->p_type = PT_LOAD;
1839 if (j == 0)
1840 ph->p_flags = PF_R | PF_X;
1841 else
1842 ph->p_flags = PF_R | PF_W;
1843 ph->p_align = s1->section_align;
1844
1845 /* Decide the layout of sections loaded in memory. This must
1846 be done before program headers are filled since they contain
1847 info about the layout. We do the following ordering: interp,
1848 symbol tables, relocations, progbits, nobits */
1849 /* XXX: do faster and simpler sorting */
1850 for(k = 0; k < 5; k++) {
1851 for(i = 1; i < s1->nb_sections; i++) {
1852 s = s1->sections[i];
1853 /* compute if section should be included */
1854 if (j == 0) {
1855 if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) !=
1856 SHF_ALLOC)
1857 continue;
1858 } else {
1859 if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) !=
1860 (SHF_ALLOC | SHF_WRITE))
1861 continue;
1862 }
1863 if (s == interp) {
1864 if (k != 0)
1865 continue;
1866 } else if (s->sh_type == SHT_DYNSYM ||
1867 s->sh_type == SHT_STRTAB ||
1868 s->sh_type == SHT_HASH) {
1869 if (k != 1)
1870 continue;
1871 } else if (s->sh_type == SHT_RELX) {
1872 if (k != 2)
1873 continue;
1874 } else if (s->sh_type == SHT_NOBITS) {
1875 if (k != 4)
1876 continue;
1877 } else {
1878 if (k != 3)
1879 continue;
1880 }
1881 sec_order[sh_order_index++] = i;
1882
1883 /* section matches: we align it and add its size */
1884 tmp = addr;
1885 addr = (addr + s->sh_addralign - 1) &
1886 ~(s->sh_addralign - 1);
1887 file_offset += (int) ( addr - tmp );
1888 s->sh_offset = file_offset;
1889 s->sh_addr = addr;
1890
1891 /* update program header infos */
1892 if (ph->p_offset == 0) {
1893 ph->p_offset = file_offset;
1894 ph->p_vaddr = addr;
1895 ph->p_paddr = ph->p_vaddr;
1896 }
1897 /* update dynamic relocation infos */
1898 if (s->sh_type == SHT_RELX) {
1899 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1900 if (!strcmp(strsec->data + s->sh_name, ".rel.got")) {
1901 dyninf->rel_addr = addr;
1902 dyninf->rel_size += s->sh_size; /* XXX only first rel. */
1903 }
1904 if (!strcmp(strsec->data + s->sh_name, ".rel.bss")) {
1905 dyninf->bss_addr = addr;
1906 dyninf->bss_size = s->sh_size; /* XXX only first rel. */
1907 }
1908 #else
1909 if (dyninf->rel_size == 0)
1910 dyninf->rel_addr = addr;
1911 dyninf->rel_size += s->sh_size;
1912 #endif
1913 }
1914 addr += s->sh_size;
1915 if (s->sh_type != SHT_NOBITS)
1916 file_offset += s->sh_size;
1917 }
1918 }
1919 ph->p_filesz = file_offset - ph->p_offset;
1920 ph->p_memsz = addr - ph->p_vaddr;
1921 ph++;
1922 if (j == 0) {
1923 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF) {
1924 /* if in the middle of a page, we duplicate the page in
1925 memory so that one copy is RX and the other is RW */
1926 if ((addr & (s1->section_align - 1)) != 0)
1927 addr += s1->section_align;
1928 } else {
1929 addr = (addr + s1->section_align - 1) & ~(s1->section_align - 1);
1930 file_offset = (file_offset + s1->section_align - 1) &
1931 ~(s1->section_align - 1);
1932 }
1933 }
1934 }
1935 }
1936
1937 /* all other sections come after */
1938 for(i = 1; i < s1->nb_sections; i++) {
1939 s = s1->sections[i];
1940 if (phnum > 0 && (s->sh_flags & SHF_ALLOC))
1941 continue;
1942 sec_order[sh_order_index++] = i;
1943
1944 file_offset = (file_offset + s->sh_addralign - 1) &
1945 ~(s->sh_addralign - 1);
1946 s->sh_offset = file_offset;
1947 if (s->sh_type != SHT_NOBITS)
1948 file_offset += s->sh_size;
1949 }
1950
1951 return file_offset;
1952 }
1953
1954 static void fill_unloadable_phdr(ElfW(Phdr) *phdr, int phnum, Section *interp,
1955 Section *dynamic)
1956 {
1957 ElfW(Phdr) *ph;
1958
1959 /* if interpreter, then add corresponding program header */
1960 if (interp) {
1961 ph = &phdr[0];
1962
1963 if (HAVE_PHDR)
1964 {
1965 int len = phnum * sizeof(ElfW(Phdr));
1966
1967 ph->p_type = PT_PHDR;
1968 ph->p_offset = sizeof(ElfW(Ehdr));
1969 ph->p_vaddr = interp->sh_addr - len;
1970 ph->p_paddr = ph->p_vaddr;
1971 ph->p_filesz = ph->p_memsz = len;
1972 ph->p_flags = PF_R | PF_X;
1973 ph->p_align = 4; /* interp->sh_addralign; */
1974 ph++;
1975 }
1976
1977 ph->p_type = PT_INTERP;
1978 ph->p_offset = interp->sh_offset;
1979 ph->p_vaddr = interp->sh_addr;
1980 ph->p_paddr = ph->p_vaddr;
1981 ph->p_filesz = interp->sh_size;
1982 ph->p_memsz = interp->sh_size;
1983 ph->p_flags = PF_R;
1984 ph->p_align = interp->sh_addralign;
1985 }
1986
1987 /* if dynamic section, then add corresponding program header */
1988 if (dynamic) {
1989 ph = &phdr[phnum - 1];
1990
1991 ph->p_type = PT_DYNAMIC;
1992 ph->p_offset = dynamic->sh_offset;
1993 ph->p_vaddr = dynamic->sh_addr;
1994 ph->p_paddr = ph->p_vaddr;
1995 ph->p_filesz = dynamic->sh_size;
1996 ph->p_memsz = dynamic->sh_size;
1997 ph->p_flags = PF_R | PF_W;
1998 ph->p_align = dynamic->sh_addralign;
1999 }
2000 }
2001
2002 /* Fill the dynamic section with tags describing the address and size of
2003 sections */
2004 static void fill_dynamic(TCCState *s1, struct dyn_inf *dyninf)
2005 {
2006 Section *dynamic;
2007
2008 dynamic = dyninf->dynamic;
2009
2010 /* put dynamic section entries */
2011 dynamic->data_offset = dyninf->dyn_rel_off;
2012 put_dt(dynamic, DT_HASH, s1->dynsym->hash->sh_addr);
2013 put_dt(dynamic, DT_STRTAB, dyninf->dynstr->sh_addr);
2014 put_dt(dynamic, DT_SYMTAB, s1->dynsym->sh_addr);
2015 put_dt(dynamic, DT_STRSZ, dyninf->dynstr->data_offset);
2016 put_dt(dynamic, DT_SYMENT, sizeof(ElfW(Sym)));
2017 #ifdef TCC_TARGET_X86_64
2018 put_dt(dynamic, DT_RELA, dyninf->rel_addr);
2019 put_dt(dynamic, DT_RELASZ, dyninf->rel_size);
2020 put_dt(dynamic, DT_RELAENT, sizeof(ElfW_Rel));
2021 #else
2022 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2023 put_dt(dynamic, DT_PLTGOT, s1->got->sh_addr);
2024 put_dt(dynamic, DT_PLTRELSZ, dyninf->rel_size);
2025 put_dt(dynamic, DT_JMPREL, dyninf->rel_addr);
2026 put_dt(dynamic, DT_PLTREL, DT_REL);
2027 put_dt(dynamic, DT_REL, dyninf->bss_addr);
2028 put_dt(dynamic, DT_RELSZ, dyninf->bss_size);
2029 #else
2030 put_dt(dynamic, DT_REL, dyninf->rel_addr);
2031 put_dt(dynamic, DT_RELSZ, dyninf->rel_size);
2032 put_dt(dynamic, DT_RELENT, sizeof(ElfW_Rel));
2033 #endif
2034 #endif
2035 if (s1->do_debug)
2036 put_dt(dynamic, DT_DEBUG, 0);
2037 put_dt(dynamic, DT_NULL, 0);
2038 }
2039
2040 /* Relocate remaining sections and symbols (that is those not related to
2041 dynamic linking) */
2042 static int final_sections_reloc(TCCState *s1)
2043 {
2044 int i;
2045 Section *s;
2046
2047 relocate_syms(s1, 0);
2048
2049 if (s1->nb_errors != 0)
2050 return -1;
2051
2052 /* relocate sections */
2053 /* XXX: ignore sections with allocated relocations ? */
2054 for(i = 1; i < s1->nb_sections; i++) {
2055 s = s1->sections[i];
2056 if (s->reloc && s != s1->got)
2057 relocate_section(s1, s);
2058 }
2059
2060 /* relocate relocation entries if the relocation tables are
2061 allocated in the executable */
2062 for(i = 1; i < s1->nb_sections; i++) {
2063 s = s1->sections[i];
2064 if ((s->sh_flags & SHF_ALLOC) &&
2065 s->sh_type == SHT_RELX) {
2066 relocate_rel(s1, s);
2067 }
2068 }
2069 return 0;
2070 }
2071
2072 /* Create an ELF file on disk.
2073 This function handle ELF specific layout requirements */
2074 static void tcc_output_elf(TCCState *s1, FILE *f, int phnum, ElfW(Phdr) *phdr,
2075 int file_offset, int *sec_order)
2076 {
2077 int i, shnum, offset, size, file_type;
2078 Section *s;
2079 ElfW(Ehdr) ehdr;
2080 ElfW(Shdr) shdr, *sh;
2081
2082 file_type = s1->output_type;
2083 shnum = s1->nb_sections;
2084
2085 memset(&ehdr, 0, sizeof(ehdr));
2086
2087 if (phnum > 0) {
2088 ehdr.e_phentsize = sizeof(ElfW(Phdr));
2089 ehdr.e_phnum = phnum;
2090 ehdr.e_phoff = sizeof(ElfW(Ehdr));
2091 }
2092
2093 /* align to 4 */
2094 file_offset = (file_offset + 3) & -4;
2095
2096 /* fill header */
2097 ehdr.e_ident[0] = ELFMAG0;
2098 ehdr.e_ident[1] = ELFMAG1;
2099 ehdr.e_ident[2] = ELFMAG2;
2100 ehdr.e_ident[3] = ELFMAG3;
2101 ehdr.e_ident[4] = ELFCLASSW;
2102 ehdr.e_ident[5] = ELFDATA2LSB;
2103 ehdr.e_ident[6] = EV_CURRENT;
2104 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2105 ehdr.e_ident[EI_OSABI] = ELFOSABI_FREEBSD;
2106 #endif
2107 #ifdef TCC_TARGET_ARM
2108 #ifdef TCC_ARM_EABI
2109 ehdr.e_ident[EI_OSABI] = 0;
2110 ehdr.e_flags = EF_ARM_EABI_VER4;
2111 if (file_type == TCC_OUTPUT_EXE || file_type == TCC_OUTPUT_DLL)
2112 ehdr.e_flags |= EF_ARM_HASENTRY;
2113 if (s1->float_abi == ARM_HARD_FLOAT)
2114 ehdr.e_flags |= EF_ARM_VFP_FLOAT;
2115 else
2116 ehdr.e_flags |= EF_ARM_SOFT_FLOAT;
2117 #else
2118 ehdr.e_ident[EI_OSABI] = ELFOSABI_ARM;
2119 #endif
2120 #endif
2121 switch(file_type) {
2122 default:
2123 case TCC_OUTPUT_EXE:
2124 ehdr.e_type = ET_EXEC;
2125 ehdr.e_entry = get_elf_sym_addr(s1, "_start", 1);
2126 break;
2127 case TCC_OUTPUT_DLL:
2128 ehdr.e_type = ET_DYN;
2129 ehdr.e_entry = text_section->sh_addr; /* XXX: is it correct ? */
2130 break;
2131 case TCC_OUTPUT_OBJ:
2132 ehdr.e_type = ET_REL;
2133 break;
2134 }
2135 ehdr.e_machine = EM_TCC_TARGET;
2136 ehdr.e_version = EV_CURRENT;
2137 ehdr.e_shoff = file_offset;
2138 ehdr.e_ehsize = sizeof(ElfW(Ehdr));
2139 ehdr.e_shentsize = sizeof(ElfW(Shdr));
2140 ehdr.e_shnum = shnum;
2141 ehdr.e_shstrndx = shnum - 1;
2142
2143 fwrite(&ehdr, 1, sizeof(ElfW(Ehdr)), f);
2144 fwrite(phdr, 1, phnum * sizeof(ElfW(Phdr)), f);
2145 offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr));
2146
2147 sort_syms(s1, symtab_section);
2148 for(i = 1; i < s1->nb_sections; i++) {
2149 s = s1->sections[sec_order[i]];
2150 if (s->sh_type != SHT_NOBITS) {
2151 if (s->sh_type == SHT_DYNSYM)
2152 patch_dynsym_undef(s1, s);
2153 while (offset < s->sh_offset) {
2154 fputc(0, f);
2155 offset++;
2156 }
2157 size = s->sh_size;
2158 fwrite(s->data, 1, size, f);
2159 offset += size;
2160 }
2161 }
2162
2163 /* output section headers */
2164 while (offset < ehdr.e_shoff) {
2165 fputc(0, f);
2166 offset++;
2167 }
2168
2169 for(i = 0; i < s1->nb_sections; i++) {
2170 sh = &shdr;
2171 memset(sh, 0, sizeof(ElfW(Shdr)));
2172 s = s1->sections[i];
2173 if (s) {
2174 sh->sh_name = s->sh_name;
2175 sh->sh_type = s->sh_type;
2176 sh->sh_flags = s->sh_flags;
2177 sh->sh_entsize = s->sh_entsize;
2178 sh->sh_info = s->sh_info;
2179 if (s->link)
2180 sh->sh_link = s->link->sh_num;
2181 sh->sh_addralign = s->sh_addralign;
2182 sh->sh_addr = s->sh_addr;
2183 sh->sh_offset = s->sh_offset;
2184 sh->sh_size = s->sh_size;
2185 }
2186 fwrite(sh, 1, sizeof(ElfW(Shdr)), f);
2187 }
2188 }
2189
2190 /* Write an elf, coff or "binary" file */
2191 static int tcc_write_elf_file(TCCState *s1, const char *filename, int phnum,
2192 ElfW(Phdr) *phdr, int file_offset, int *sec_order)
2193 {
2194 int fd, mode, file_type;
2195 FILE *f;
2196
2197 file_type = s1->output_type;
2198 if (file_type == TCC_OUTPUT_OBJ)
2199 mode = 0666;
2200 else
2201 mode = 0777;
2202 unlink(filename);
2203 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, mode);
2204 if (fd < 0) {
2205 tcc_error_noabort("could not write '%s'", filename);
2206 return -1;
2207 }
2208 f = fdopen(fd, "wb");
2209 if (s1->verbose)
2210 printf("<- %s\n", filename);
2211
2212 #ifdef TCC_TARGET_COFF
2213 if (s1->output_format == TCC_OUTPUT_FORMAT_COFF)
2214 tcc_output_coff(s1, f);
2215 else
2216 #endif
2217 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF)
2218 tcc_output_elf(s1, f, phnum, phdr, file_offset, sec_order);
2219 else
2220 tcc_output_binary(s1, f, sec_order);
2221 fclose(f);
2222
2223 return 0;
2224 }
2225
2226 /* Output an elf, coff or binary file */
2227 /* XXX: suppress unneeded sections */
2228 static int elf_output_file(TCCState *s1, const char *filename)
2229 {
2230 int i, ret, phnum, shnum, file_type, file_offset, *sec_order;
2231 struct dyn_inf dyninf;
2232 ElfW(Phdr) *phdr;
2233 ElfW(Sym) *sym;
2234 Section *strsec, *interp, *dynamic, *dynstr;
2235
2236 file_type = s1->output_type;
2237 s1->nb_errors = 0;
2238
2239 /* if linking, also link in runtime libraries (libc, libgcc, etc.) */
2240 if (file_type != TCC_OUTPUT_OBJ) {
2241 tcc_add_runtime(s1);
2242 }
2243
2244 phdr = NULL;
2245 sec_order = NULL;
2246 interp = dynamic = dynstr = NULL; /* avoid warning */
2247 dyninf.dyn_rel_off = 0; /* avoid warning */
2248
2249 if (file_type != TCC_OUTPUT_OBJ) {
2250 relocate_common_syms();
2251
2252 tcc_add_linker_symbols(s1);
2253
2254 if (!s1->static_link) {
2255 if (file_type == TCC_OUTPUT_EXE) {
2256 char *ptr;
2257 /* allow override the dynamic loader */
2258 const char *elfint = getenv("LD_SO");
2259 if (elfint == NULL)
2260 elfint = DEFAULT_ELFINTERP(s1);
2261 /* add interpreter section only if executable */
2262 interp = new_section(s1, ".interp", SHT_PROGBITS, SHF_ALLOC);
2263 interp->sh_addralign = 1;
2264 ptr = section_ptr_add(interp, 1 + strlen(elfint));
2265 strcpy(ptr, elfint);
2266 }
2267
2268 /* add dynamic symbol table */
2269 s1->dynsym = new_symtab(s1, ".dynsym", SHT_DYNSYM, SHF_ALLOC,
2270 ".dynstr",
2271 ".hash", SHF_ALLOC);
2272 dynstr = s1->dynsym->link;
2273
2274 /* add dynamic section */
2275 dynamic = new_section(s1, ".dynamic", SHT_DYNAMIC,
2276 SHF_ALLOC | SHF_WRITE);
2277 dynamic->link = dynstr;
2278 dynamic->sh_entsize = sizeof(ElfW(Dyn));
2279
2280 /* add PLT */
2281 s1->plt = new_section(s1, ".plt", SHT_PROGBITS,
2282 SHF_ALLOC | SHF_EXECINSTR);
2283 s1->plt->sh_entsize = 4;
2284
2285 build_got(s1);
2286
2287 if (file_type == TCC_OUTPUT_EXE) {
2288 bind_exe_dynsyms(s1);
2289
2290 if (s1->nb_errors) {
2291 ret = -1;
2292 goto the_end;
2293 }
2294
2295 bind_libs_dynsyms(s1);
2296 } else /* shared library case: simply export all global symbols */
2297 export_global_syms(s1);
2298
2299 build_got_entries(s1);
2300
2301 /* add a list of needed dlls */
2302 for(i = 0; i < s1->nb_loaded_dlls; i++) {
2303 DLLReference *dllref = s1->loaded_dlls[i];
2304 if (dllref->level == 0)
2305 put_dt(dynamic, DT_NEEDED, put_elf_str(dynstr, dllref->name));
2306 }
2307
2308 if (s1->rpath)
2309 put_dt(dynamic, DT_RPATH, put_elf_str(dynstr, s1->rpath));
2310
2311 /* XXX: currently, since we do not handle PIC code, we
2312 must relocate the readonly segments */
2313 if (file_type == TCC_OUTPUT_DLL) {
2314 if (s1->soname)
2315 put_dt(dynamic, DT_SONAME, put_elf_str(dynstr, s1->soname));
2316 put_dt(dynamic, DT_TEXTREL, 0);
2317 }
2318
2319 if (s1->symbolic)
2320 put_dt(dynamic, DT_SYMBOLIC, 0);
2321
2322 /* add necessary space for other entries */
2323 dyninf.dyn_rel_off = dynamic->data_offset;
2324 dynamic->data_offset += sizeof(ElfW(Dyn)) * EXTRA_RELITEMS;
2325 } else {
2326 /* still need to build got entries in case of static link */
2327 build_got_entries(s1);
2328 }
2329 }
2330
2331 /* we add a section for symbols */
2332 strsec = new_section(s1, ".shstrtab", SHT_STRTAB, 0);
2333 put_elf_str(strsec, "");
2334
2335 /* compute number of sections */
2336 shnum = s1->nb_sections;
2337
2338 /* this array is used to reorder sections in the output file */
2339 sec_order = tcc_malloc(sizeof(int) * shnum);
2340 sec_order[0] = 0;
2341
2342 /* compute number of program headers */
2343 switch(file_type) {
2344 default:
2345 case TCC_OUTPUT_OBJ:
2346 phnum = 0;
2347 break;
2348 case TCC_OUTPUT_EXE:
2349 if (!s1->static_link)
2350 phnum = 4 + HAVE_PHDR;
2351 else
2352 phnum = 2;
2353 break;
2354 case TCC_OUTPUT_DLL:
2355 phnum = 3;
2356 break;
2357 }
2358
2359 /* Allocate strings for section names */
2360 alloc_sec_names(s1, file_type, strsec);
2361
2362 /* allocate program segment headers */
2363 phdr = tcc_mallocz(phnum * sizeof(ElfW(Phdr)));
2364
2365 /* compute section to program header mapping */
2366 file_offset = layout_sections(s1, phdr, phnum, interp, &dyninf, sec_order);
2367
2368 /* Fill remaining program header and finalize relocation related to dynamic
2369 linking. */
2370 if (phnum > 0) {
2371 fill_unloadable_phdr(phdr, phnum, interp, dynamic);
2372 if (dynamic) {
2373 dyninf.dynamic = dynamic;
2374 dyninf.dynstr = dynstr;
2375
2376 fill_dynamic(s1, &dyninf);
2377
2378 /* put in GOT the dynamic section address and relocate PLT */
2379 put32(s1->got->data, dynamic->sh_addr);
2380 if (file_type == TCC_OUTPUT_EXE
2381 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
2382 || file_type == TCC_OUTPUT_DLL
2383 #endif
2384 )
2385 relocate_plt(s1);
2386
2387 /* relocate symbols in .dynsym now that final addresses are known */
2388 for_each_elem(s1->dynsym, 1, sym, ElfW(Sym)) {
2389 /* relocate to PLT if symbol corresponds to a PLT entry */
2390 if (sym->st_shndx == SHN_UNDEF) {
2391 if (sym->st_value)
2392 sym->st_value += s1->plt->sh_addr;
2393 } else if (sym->st_shndx < SHN_LORESERVE) {
2394 /* do symbol relocation */
2395 sym->st_value += s1->sections[sym->st_shndx]->sh_addr;
2396 }
2397 }
2398 }
2399 }
2400
2401 /* if building executable or DLL, then relocate each section
2402 except the GOT which is already relocated */
2403 if (file_type != TCC_OUTPUT_OBJ) {
2404 ret = final_sections_reloc(s1);
2405 if (ret)
2406 goto the_end;
2407 }
2408
2409 /* Perform relocation to GOT or PLT entries */
2410 if (file_type == TCC_OUTPUT_EXE && s1->static_link)
2411 fill_got(s1);
2412
2413 /* Create the ELF file with name 'filename' */
2414 ret = tcc_write_elf_file(s1, filename, phnum, phdr, file_offset, sec_order);
2415 the_end:
2416 tcc_free(s1->symtab_to_dynsym);
2417 tcc_free(sec_order);
2418 tcc_free(phdr);
2419 tcc_free(s1->sym_attrs);
2420 return ret;
2421 }
2422
2423 LIBTCCAPI int tcc_output_file(TCCState *s, const char *filename)
2424 {
2425 int ret;
2426 #ifdef TCC_TARGET_PE
2427 if (s->output_type != TCC_OUTPUT_OBJ) {
2428 ret = pe_output_file(s, filename);
2429 } else
2430 #endif
2431 ret = elf_output_file(s, filename);
2432 return ret;
2433 }
2434
2435 static void *load_data(int fd, unsigned long file_offset, unsigned long size)
2436 {
2437 void *data;
2438
2439 data = tcc_malloc(size);
2440 lseek(fd, file_offset, SEEK_SET);
2441 read(fd, data, size);
2442 return data;
2443 }
2444
2445 typedef struct SectionMergeInfo {
2446 Section *s; /* corresponding existing section */
2447 unsigned long offset; /* offset of the new section in the existing section */
2448 uint8_t new_section; /* true if section 's' was added */
2449 uint8_t link_once; /* true if link once section */
2450 } SectionMergeInfo;
2451
2452 /* load an object file and merge it with current files */
2453 /* XXX: handle correctly stab (debug) info */
2454 ST_FUNC int tcc_load_object_file(TCCState *s1,
2455 int fd, unsigned long file_offset)
2456 {
2457 ElfW(Ehdr) ehdr;
2458 ElfW(Shdr) *shdr, *sh;
2459 int size, i, j, offset, offseti, nb_syms, sym_index, ret;
2460 unsigned char *strsec, *strtab;
2461 int *old_to_new_syms;
2462 char *sh_name, *name;
2463 SectionMergeInfo *sm_table, *sm;
2464 ElfW(Sym) *sym, *symtab;
2465 ElfW_Rel *rel;
2466 Section *s;
2467
2468 int stab_index;
2469 int stabstr_index;
2470
2471 stab_index = stabstr_index = 0;
2472
2473 if (read(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr))
2474 goto fail1;
2475 if (ehdr.e_ident[0] != ELFMAG0 ||
2476 ehdr.e_ident[1] != ELFMAG1 ||
2477 ehdr.e_ident[2] != ELFMAG2 ||
2478 ehdr.e_ident[3] != ELFMAG3)
2479 goto fail1;
2480 /* test if object file */
2481 if (ehdr.e_type != ET_REL)
2482 goto fail1;
2483 /* test CPU specific stuff */
2484 if (ehdr.e_ident[5] != ELFDATA2LSB ||
2485 ehdr.e_machine != EM_TCC_TARGET) {
2486 fail1:
2487 tcc_error_noabort("invalid object file");
2488 return -1;
2489 }
2490 /* read sections */
2491 shdr = load_data(fd, file_offset + ehdr.e_shoff,
2492 sizeof(ElfW(Shdr)) * ehdr.e_shnum);
2493 sm_table = tcc_mallocz(sizeof(SectionMergeInfo) * ehdr.e_shnum);
2494
2495 /* load section names */
2496 sh = &shdr[ehdr.e_shstrndx];
2497 strsec = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2498
2499 /* load symtab and strtab */
2500 old_to_new_syms = NULL;
2501 symtab = NULL;
2502 strtab = NULL;
2503 nb_syms = 0;
2504 for(i = 1; i < ehdr.e_shnum; i++) {
2505 sh = &shdr[i];
2506 if (sh->sh_type == SHT_SYMTAB) {
2507 if (symtab) {
2508 tcc_error_noabort("object must contain only one symtab");
2509 fail:
2510 ret = -1;
2511 goto the_end;
2512 }
2513 nb_syms = sh->sh_size / sizeof(ElfW(Sym));
2514 symtab = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2515 sm_table[i].s = symtab_section;
2516
2517 /* now load strtab */
2518 sh = &shdr[sh->sh_link];
2519 strtab = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2520 }
2521 }
2522
2523 /* now examine each section and try to merge its content with the
2524 ones in memory */
2525 for(i = 1; i < ehdr.e_shnum; i++) {
2526 /* no need to examine section name strtab */
2527 if (i == ehdr.e_shstrndx)
2528 continue;
2529 sh = &shdr[i];
2530 sh_name = strsec + sh->sh_name;
2531 /* ignore sections types we do not handle */
2532 if (sh->sh_type != SHT_PROGBITS &&
2533 sh->sh_type != SHT_RELX &&
2534 #ifdef TCC_ARM_EABI
2535 sh->sh_type != SHT_ARM_EXIDX &&
2536 #endif
2537 sh->sh_type != SHT_NOBITS &&
2538 sh->sh_type != SHT_PREINIT_ARRAY &&
2539 sh->sh_type != SHT_INIT_ARRAY &&
2540 sh->sh_type != SHT_FINI_ARRAY &&
2541 strcmp(sh_name, ".stabstr")
2542 )
2543 continue;
2544 if (sh->sh_addralign < 1)
2545 sh->sh_addralign = 1;
2546 /* find corresponding section, if any */
2547 for(j = 1; j < s1->nb_sections;j++) {
2548 s = s1->sections[j];
2549 if (!strcmp(s->name, sh_name)) {
2550 if (!strncmp(sh_name, ".gnu.linkonce",
2551 sizeof(".gnu.linkonce") - 1)) {
2552 /* if a 'linkonce' section is already present, we
2553 do not add it again. It is a little tricky as
2554 symbols can still be defined in
2555 it. */
2556 sm_table[i].link_once = 1;
2557 goto next;
2558 } else {
2559 goto found;
2560 }
2561 }
2562 }
2563 /* not found: create new section */
2564 s = new_section(s1, sh_name, sh->sh_type, sh->sh_flags);
2565 /* take as much info as possible from the section. sh_link and
2566 sh_info will be updated later */
2567 s->sh_addralign = sh->sh_addralign;
2568 s->sh_entsize = sh->sh_entsize;
2569 sm_table[i].new_section = 1;
2570 found:
2571 if (sh->sh_type != s->sh_type) {
2572 tcc_error_noabort("invalid section type");
2573 goto fail;
2574 }
2575
2576 /* align start of section */
2577 offset = s->data_offset;
2578
2579 if (0 == strcmp(sh_name, ".stab")) {
2580 stab_index = i;
2581 goto no_align;
2582 }
2583 if (0 == strcmp(sh_name, ".stabstr")) {
2584 stabstr_index = i;
2585 goto no_align;
2586 }
2587
2588 size = sh->sh_addralign - 1;
2589 offset = (offset + size) & ~size;
2590 if (sh->sh_addralign > s->sh_addralign)
2591 s->sh_addralign = sh->sh_addralign;
2592 s->data_offset = offset;
2593 no_align:
2594 sm_table[i].offset = offset;
2595 sm_table[i].s = s;
2596 /* concatenate sections */
2597 size = sh->sh_size;
2598 if (sh->sh_type != SHT_NOBITS) {
2599 unsigned char *ptr;
2600 lseek(fd, file_offset + sh->sh_offset, SEEK_SET);
2601 ptr = section_ptr_add(s, size);
2602 read(fd, ptr, size);
2603 } else {
2604 s->data_offset += size;
2605 }
2606 next: ;
2607 }
2608
2609 /* gr relocate stab strings */
2610 if (stab_index && stabstr_index) {
2611 Stab_Sym *a, *b;
2612 unsigned o;
2613 s = sm_table[stab_index].s;
2614 a = (Stab_Sym *)(s->data + sm_table[stab_index].offset);
2615 b = (Stab_Sym *)(s->data + s->data_offset);
2616 o = sm_table[stabstr_index].offset;
2617 while (a < b)
2618 a->n_strx += o, a++;
2619 }
2620
2621 /* second short pass to update sh_link and sh_info fields of new
2622 sections */
2623 for(i = 1; i < ehdr.e_shnum; i++) {
2624 s = sm_table[i].s;
2625 if (!s || !sm_table[i].new_section)
2626 continue;
2627 sh = &shdr[i];
2628 if (sh->sh_link > 0)
2629 s->link = sm_table[sh->sh_link].s;
2630 if (sh->sh_type == SHT_RELX) {
2631 s->sh_info = sm_table[sh->sh_info].s->sh_num;
2632 /* update backward link */
2633 s1->sections[s->sh_info]->reloc = s;
2634 }
2635 }
2636 sm = sm_table;
2637
2638 /* resolve symbols */
2639 old_to_new_syms = tcc_mallocz(nb_syms * sizeof(int));
2640
2641 sym = symtab + 1;
2642 for(i = 1; i < nb_syms; i++, sym++) {
2643 if (sym->st_shndx != SHN_UNDEF &&
2644 sym->st_shndx < SHN_LORESERVE) {
2645 sm = &sm_table[sym->st_shndx];
2646 if (sm->link_once) {
2647 /* if a symbol is in a link once section, we use the
2648 already defined symbol. It is very important to get
2649 correct relocations */
2650 if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
2651 name = strtab + sym->st_name;
2652 sym_index = find_elf_sym(symtab_section, name);
2653 if (sym_index)
2654 old_to_new_syms[i] = sym_index;
2655 }
2656 continue;
2657 }
2658 /* if no corresponding section added, no need to add symbol */
2659 if (!sm->s)
2660 continue;
2661 /* convert section number */
2662 sym->st_shndx = sm->s->sh_num;
2663 /* offset value */
2664 sym->st_value += sm->offset;
2665 }
2666 /* add symbol */
2667 name = strtab + sym->st_name;
2668 sym_index = add_elf_sym(symtab_section, sym->st_value, sym->st_size,
2669 sym->st_info, sym->st_other,
2670 sym->st_shndx, name);
2671 old_to_new_syms[i] = sym_index;
2672 }
2673
2674 /* third pass to patch relocation entries */
2675 for(i = 1; i < ehdr.e_shnum; i++) {
2676 s = sm_table[i].s;
2677 if (!s)
2678 continue;
2679 sh = &shdr[i];
2680 offset = sm_table[i].offset;
2681 switch(s->sh_type) {
2682 case SHT_RELX:
2683 /* take relocation offset information */
2684 offseti = sm_table[sh->sh_info].offset;
2685 for_each_elem(s, (offset / sizeof(*rel)), rel, ElfW_Rel) {
2686 int type;
2687 unsigned sym_index;
2688 /* convert symbol index */
2689 type = ELFW(R_TYPE)(rel->r_info);
2690 sym_index = ELFW(R_SYM)(rel->r_info);
2691 /* NOTE: only one symtab assumed */
2692 if (sym_index >= nb_syms)
2693 goto invalid_reloc;
2694 sym_index = old_to_new_syms[sym_index];
2695 /* ignore link_once in rel section. */
2696 if (!sym_index && !sm->link_once
2697 #ifdef TCC_TARGET_ARM
2698 && type != R_ARM_V4BX
2699 #endif
2700 ) {
2701 invalid_reloc:
2702 tcc_error_noabort("Invalid relocation entry [%2d] '%s' @ %.8x",
2703 i, strsec + sh->sh_name, rel->r_offset);
2704 goto fail;
2705 }
2706 rel->r_info = ELFW(R_INFO)(sym_index, type);
2707 /* offset the relocation offset */
2708 rel->r_offset += offseti;
2709 #ifdef TCC_TARGET_ARM
2710 /* Jumps and branches from a Thumb code to a PLT entry need
2711 special handling since PLT entries are ARM code.
2712 Unconditional bl instructions referencing PLT entries are
2713 handled by converting these instructions into blx
2714 instructions. Other case of instructions referencing a PLT
2715 entry require to add a Thumb stub before the PLT entry to
2716 switch to ARM mode. We set bit plt_thumb_stub of the
2717 attribute of a symbol to indicate such a case. */
2718 if (type == R_ARM_THM_JUMP24)
2719 alloc_sym_attr(s1, sym_index)->plt_thumb_stub = 1;
2720 #endif
2721 }
2722 break;
2723 default:
2724 break;
2725 }
2726 }
2727
2728 ret = 0;
2729 the_end:
2730 tcc_free(symtab);
2731 tcc_free(strtab);
2732 tcc_free(old_to_new_syms);
2733 tcc_free(sm_table);
2734 tcc_free(strsec);
2735 tcc_free(shdr);
2736 return ret;
2737 }
2738
2739 typedef struct ArchiveHeader {
2740 char ar_name[16]; /* name of this member */
2741 char ar_date[12]; /* file mtime */
2742 char ar_uid[6]; /* owner uid; printed as decimal */
2743 char ar_gid[6]; /* owner gid; printed as decimal */
2744 char ar_mode[8]; /* file mode, printed as octal */
2745 char ar_size[10]; /* file size, printed as decimal */
2746 char ar_fmag[2]; /* should contain ARFMAG */
2747 } ArchiveHeader;
2748
2749 static int get_be32(const uint8_t *b)
2750 {
2751 return b[3] | (b[2] << 8) | (b[1] << 16) | (b[0] << 24);
2752 }
2753
2754 /* load only the objects which resolve undefined symbols */
2755 static int tcc_load_alacarte(TCCState *s1, int fd, int size)
2756 {
2757 int i, bound, nsyms, sym_index, off, ret;
2758 uint8_t *data;
2759 const char *ar_names, *p;
2760 const uint8_t *ar_index;
2761 ElfW(Sym) *sym;
2762
2763 data = tcc_malloc(size);
2764 if (read(fd, data, size) != size)
2765 goto fail;
2766 nsyms = get_be32(data);
2767 ar_index = data + 4;
2768 ar_names = ar_index + nsyms * 4;
2769
2770 do {
2771 bound = 0;
2772 for(p = ar_names, i = 0; i < nsyms; i++, p += strlen(p)+1) {
2773 sym_index = find_elf_sym(symtab_section, p);
2774 if(sym_index) {
2775 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
2776 if(sym->st_shndx == SHN_UNDEF) {
2777 off = get_be32(ar_index + i * 4) + sizeof(ArchiveHeader);
2778 ++bound;
2779 lseek(fd, off, SEEK_SET);
2780 if(tcc_load_object_file(s1, fd, off) < 0) {
2781 fail:
2782 ret = -1;
2783 goto the_end;
2784 }
2785 }
2786 }
2787 }
2788 } while(bound);
2789 ret = 0;
2790 the_end:
2791 tcc_free(data);
2792 return ret;
2793 }
2794
2795 /* load a '.a' file */
2796 ST_FUNC int tcc_load_archive(TCCState *s1, int fd)
2797 {
2798 ArchiveHeader hdr;
2799 char ar_size[11];
2800 char ar_name[17];
2801 char magic[8];
2802 int size, len, i;
2803 unsigned long file_offset;
2804
2805 /* skip magic which was already checked */
2806 read(fd, magic, sizeof(magic));
2807
2808 for(;;) {
2809 len = read(fd, &hdr, sizeof(hdr));
2810 if (len == 0)
2811 break;
2812 if (len != sizeof(hdr)) {
2813 tcc_error_noabort("invalid archive");
2814 return -1;
2815 }
2816 memcpy(ar_size, hdr.ar_size, sizeof(hdr.ar_size));
2817 ar_size[sizeof(hdr.ar_size)] = '\0';
2818 size = strtol(ar_size, NULL, 0);
2819 memcpy(ar_name, hdr.ar_name, sizeof(hdr.ar_name));
2820 for(i = sizeof(hdr.ar_name) - 1; i >= 0; i--) {
2821 if (ar_name[i] != ' ')
2822 break;
2823 }
2824 ar_name[i + 1] = '\0';
2825 file_offset = lseek(fd, 0, SEEK_CUR);
2826 /* align to even */
2827 size = (size + 1) & ~1;
2828 if (!strcmp(ar_name, "/")) {
2829 /* coff symbol table : we handle it */
2830 if(s1->alacarte_link)
2831 return tcc_load_alacarte(s1, fd, size);
2832 } else if (!strcmp(ar_name, "//") ||
2833 !strcmp(ar_name, "__.SYMDEF") ||
2834 !strcmp(ar_name, "__.SYMDEF/") ||
2835 !strcmp(ar_name, "ARFILENAMES/")) {
2836 /* skip symbol table or archive names */
2837 } else {
2838 if (tcc_load_object_file(s1, fd, file_offset) < 0)
2839 return -1;
2840 }
2841 lseek(fd, file_offset + size, SEEK_SET);
2842 }
2843 return 0;
2844 }
2845
2846 #ifndef TCC_TARGET_PE
2847 /* load a DLL and all referenced DLLs. 'level = 0' means that the DLL
2848 is referenced by the user (so it should be added as DT_NEEDED in
2849 the generated ELF file) */
2850 ST_FUNC int tcc_load_dll(TCCState *s1, int fd, const char *filename, int level)
2851 {
2852 ElfW(Ehdr) ehdr;
2853 ElfW(Shdr) *shdr, *sh, *sh1;
2854 int i, j, nb_syms, nb_dts, sym_bind, ret;
2855 ElfW(Sym) *sym, *dynsym;
2856 ElfW(Dyn) *dt, *dynamic;
2857 unsigned char *dynstr;
2858 const char *name, *soname;
2859 DLLReference *dllref;
2860
2861 read(fd, &ehdr, sizeof(ehdr));
2862
2863 /* test CPU specific stuff */
2864 if (ehdr.e_ident[5] != ELFDATA2LSB ||
2865 ehdr.e_machine != EM_TCC_TARGET) {
2866 tcc_error_noabort("bad architecture");
2867 return -1;
2868 }
2869
2870 /* read sections */
2871 shdr = load_data(fd, ehdr.e_shoff, sizeof(ElfW(Shdr)) * ehdr.e_shnum);
2872
2873 /* load dynamic section and dynamic symbols */
2874 nb_syms = 0;
2875 nb_dts = 0;
2876 dynamic = NULL;
2877 dynsym = NULL; /* avoid warning */
2878 dynstr = NULL; /* avoid warning */
2879 for(i = 0, sh = shdr; i < ehdr.e_shnum; i++, sh++) {
2880 switch(sh->sh_type) {
2881 case SHT_DYNAMIC:
2882 nb_dts = sh->sh_size / sizeof(ElfW(Dyn));
2883 dynamic = load_data(fd, sh->sh_offset, sh->sh_size);
2884 break;
2885 case SHT_DYNSYM:
2886 nb_syms = sh->sh_size / sizeof(ElfW(Sym));
2887 dynsym = load_data(fd, sh->sh_offset, sh->sh_size);
2888 sh1 = &shdr[sh->sh_link];
2889 dynstr = load_data(fd, sh1->sh_offset, sh1->sh_size);
2890 break;
2891 default:
2892 break;
2893 }
2894 }
2895
2896 /* compute the real library name */
2897 soname = tcc_basename(filename);
2898
2899 for(i = 0, dt = dynamic; i < nb_dts; i++, dt++) {
2900 if (dt->d_tag == DT_SONAME) {
2901 soname = dynstr + dt->d_un.d_val;
2902 }
2903 }
2904
2905 /* if the dll is already loaded, do not load it */
2906 for(i = 0; i < s1->nb_loaded_dlls; i++) {
2907 dllref = s1->loaded_dlls[i];
2908 if (!strcmp(soname, dllref->name)) {
2909 /* but update level if needed */
2910 if (level < dllref->level)
2911 dllref->level = level;
2912 ret = 0;
2913 goto the_end;
2914 }
2915 }
2916
2917 /* add the dll and its level */
2918 dllref = tcc_mallocz(sizeof(DLLReference) + strlen(soname));
2919 dllref->level = level;
2920 strcpy(dllref->name, soname);
2921 dynarray_add((void ***)&s1->loaded_dlls, &s1->nb_loaded_dlls, dllref);
2922
2923 /* add dynamic symbols in dynsym_section */
2924 for(i = 1, sym = dynsym + 1; i < nb_syms; i++, sym++) {
2925 sym_bind = ELFW(ST_BIND)(sym->st_info);
2926 if (sym_bind == STB_LOCAL)
2927 continue;
2928 name = dynstr + sym->st_name;
2929 add_elf_sym(s1->dynsymtab_section, sym->st_value, sym->st_size,
2930 sym->st_info, sym->st_other, sym->st_shndx, name);
2931 }
2932
2933 /* load all referenced DLLs */
2934 for(i = 0, dt = dynamic; i < nb_dts; i++, dt++) {
2935 switch(dt->d_tag) {
2936 case DT_NEEDED:
2937 name = dynstr + dt->d_un.d_val;
2938 for(j = 0; j < s1->nb_loaded_dlls; j++) {
2939 dllref = s1->loaded_dlls[j];
2940 if (!strcmp(name, dllref->name))
2941 goto already_loaded;
2942 }
2943 if (tcc_add_dll(s1, name, AFF_REFERENCED_DLL) < 0) {
2944 tcc_error_noabort("referenced dll '%s' not found", name);
2945 ret = -1;
2946 goto the_end;
2947 }
2948 already_loaded:
2949 break;
2950 }
2951 }
2952 ret = 0;
2953 the_end:
2954 tcc_free(dynstr);
2955 tcc_free(dynsym);
2956 tcc_free(dynamic);
2957 tcc_free(shdr);
2958 return ret;
2959 }
2960
2961 #define LD_TOK_NAME 256
2962 #define LD_TOK_EOF (-1)
2963
2964 /* return next ld script token */
2965 static int ld_next(TCCState *s1, char *name, int name_size)
2966 {
2967 int c;
2968 char *q;
2969
2970 redo:
2971 switch(ch) {
2972 case ' ':
2973 case '\t':
2974 case '\f':
2975 case '\v':
2976 case '\r':
2977 case '\n':
2978 inp();
2979 goto redo;
2980 case '/':
2981 minp();
2982 if (ch == '*') {
2983 file->buf_ptr = parse_comment(file->buf_ptr);
2984 ch = file->buf_ptr[0];
2985 goto redo;
2986 } else {
2987 q = name;
2988 *q++ = '/';
2989 goto parse_name;
2990 }
2991 break;
2992 /* case 'a' ... 'z': */
2993 case 'a':
2994 case 'b':
2995 case 'c':
2996 case 'd':
2997 case 'e':
2998 case 'f':
2999 case 'g':
3000 case 'h':
3001 case 'i':
3002 case 'j':
3003 case 'k':
3004 case 'l':
3005 case 'm':
3006 case 'n':
3007 case 'o':
3008 case 'p':
3009 case 'q':
3010 case 'r':
3011 case 's':
3012 case 't':
3013 case 'u':
3014 case 'v':
3015 case 'w':
3016 case 'x':
3017 case 'y':
3018 case 'z':
3019 /* case 'A' ... 'z': */
3020 case 'A':
3021 case 'B':
3022 case 'C':
3023 case 'D':
3024 case 'E':
3025 case 'F':
3026 case 'G':
3027 case 'H':
3028 case 'I':
3029 case 'J':
3030 case 'K':
3031 case 'L':
3032 case 'M':
3033 case 'N':
3034 case 'O':
3035 case 'P':
3036 case 'Q':
3037 case 'R':
3038 case 'S':
3039 case 'T':
3040 case 'U':
3041 case 'V':
3042 case 'W':
3043 case 'X':
3044 case 'Y':
3045 case 'Z':
3046 case '_':
3047 case '\\':
3048 case '.':
3049 case '$':
3050 case '~':
3051 q = name;
3052 parse_name:
3053 for(;;) {
3054 if (!((ch >= 'a' && ch <= 'z') ||
3055 (ch >= 'A' && ch <= 'Z') ||
3056 (ch >= '0' && ch <= '9') ||
3057 strchr("/.-_+=$:\\,~", ch)))
3058 break;
3059 if ((q - name) < name_size - 1) {
3060 *q++ = ch;
3061 }
3062 minp();
3063 }
3064 *q = '\0';
3065 c = LD_TOK_NAME;
3066 break;
3067 case CH_EOF:
3068 c = LD_TOK_EOF;
3069 break;
3070 default:
3071 c = ch;
3072 inp();
3073 break;
3074 }
3075 return c;
3076 }
3077
3078 static int ld_add_file(TCCState *s1, const char filename[])
3079 {
3080 int ret;
3081
3082 ret = tcc_add_file_internal(s1, filename, 0);
3083 if (ret)
3084 ret = tcc_add_dll(s1, filename, 0);
3085 return ret;
3086 }
3087
3088 static inline int new_undef_syms(void)
3089 {
3090 int ret = 0;
3091 ret = new_undef_sym;
3092 new_undef_sym = 0;
3093 return ret;
3094 }
3095
3096 static int ld_add_file_list(TCCState *s1, const char *cmd, int as_needed)
3097 {
3098 char filename[1024], libname[1024];
3099 int t, group, nblibs = 0, ret = 0;
3100 char **libs = NULL;
3101
3102 group = !strcmp(cmd, "GROUP");
3103 if (!as_needed)
3104 new_undef_syms();
3105 t = ld_next(s1, filename, sizeof(filename));
3106 if (t != '(')
3107 expect("(");
3108 t = ld_next(s1, filename, sizeof(filename));
3109 for(;;) {
3110 libname[0] = '\0';
3111 if (t == LD_TOK_EOF) {
3112 tcc_error_noabort("unexpected end of file");
3113 ret = -1;
3114 goto lib_parse_error;
3115 } else if (t == ')') {
3116 break;
3117 } else if (t == '-') {
3118 t = ld_next(s1, filename, sizeof(filename));
3119 if ((t != LD_TOK_NAME) || (filename[0] != 'l')) {
3120 tcc_error_noabort("library name expected");
3121 ret = -1;
3122 goto lib_parse_error;
3123 }
3124 pstrcpy(libname, sizeof libname, &filename[1]);
3125 if (s1->static_link) {
3126 snprintf(filename, sizeof filename, "lib%s.a", libname);
3127 } else {
3128 snprintf(filename, sizeof filename, "lib%s.so", libname);
3129 }
3130 } else if (t != LD_TOK_NAME) {
3131 tcc_error_noabort("filename expected");
3132 ret = -1;
3133 goto lib_parse_error;
3134 }
3135 if (!strcmp(filename, "AS_NEEDED")) {
3136 ret = ld_add_file_list(s1, cmd, 1);
3137 if (ret)
3138 goto lib_parse_error;
3139 } else {
3140 /* TODO: Implement AS_NEEDED support. Ignore it for now */
3141 if (!as_needed) {
3142 ret = ld_add_file(s1, filename);
3143 if (ret)
3144 goto lib_parse_error;
3145 if (group) {
3146 /* Add the filename *and* the libname to avoid future conversions */
3147 dynarray_add((void ***) &libs, &nblibs, tcc_strdup(filename));
3148 if (libname[0] != '\0')
3149 dynarray_add((void ***) &libs, &nblibs, tcc_strdup(libname));
3150 }
3151 }
3152 }
3153 t = ld_next(s1, filename, sizeof(filename));
3154 if (t == ',') {
3155 t = ld_next(s1, filename, sizeof(filename));
3156 }
3157 }
3158 if (group && !as_needed) {
3159 while (new_undef_syms()) {
3160 int i;
3161
3162 for (i = 0; i < nblibs; i ++)
3163 ld_add_file(s1, libs[i]);
3164 }
3165 }
3166 lib_parse_error:
3167 dynarray_reset(&libs, &nblibs);
3168 return ret;
3169 }
3170
3171 /* interpret a subset of GNU ldscripts to handle the dummy libc.so
3172 files */
3173 ST_FUNC int tcc_load_ldscript(TCCState *s1)
3174 {
3175 char cmd[64];
3176 char filename[1024];
3177 int t, ret;
3178
3179 ch = file->buf_ptr[0];
3180 ch = handle_eob();
3181 for(;;) {
3182 t = ld_next(s1, cmd, sizeof(cmd));
3183 if (t == LD_TOK_EOF)
3184 return 0;
3185 else if (t != LD_TOK_NAME)
3186 return -1;
3187 if (!strcmp(cmd, "INPUT") ||
3188 !strcmp(cmd, "GROUP")) {
3189 ret = ld_add_file_list(s1, cmd, 0);
3190 if (ret)
3191 return ret;
3192 } else if (!strcmp(cmd, "OUTPUT_FORMAT") ||
3193 !strcmp(cmd, "TARGET")) {
3194 /* ignore some commands */
3195 t = ld_next(s1, cmd, sizeof(cmd));
3196 if (t != '(')
3197 expect("(");
3198 for(;;) {
3199 t = ld_next(s1, filename, sizeof(filename));
3200 if (t == LD_TOK_EOF) {
3201 tcc_error_noabort("unexpected end of file");
3202 return -1;
3203 } else if (t == ')') {
3204 break;
3205 }
3206 }
3207 } else {
3208 return -1;
3209 }
3210 }
3211 return 0;
3212 }
3213 #endif /* !TCC_TARGET_PE */
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