?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
Fix relocation of __bound_init
[tinycc.git] / tccelf.c
blobee00b03547f07dfec868813c906eaa4cad0aaa1f
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 unsigned 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((unsigned char *) 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((unsigned char *) 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 = (char *) 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 = (char *) 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 = (char *) 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 = (char *) 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 = (char *) 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 + 4, 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 /* add libc */
1377 if (!s1->nostdlib) {
1378 tcc_add_library(s1, "c");
1379 #ifdef CONFIG_USE_LIBGCC
1380 if (!s1->static_link)
1381 tcc_add_file(s1, TCC_LIBGCC);
1382 else
1383 tcc_add_support(s1, "libtcc1.a");
1384 #else
1385 tcc_add_support(s1, "libtcc1.a");
1386 #endif
1387 }
1388
1389 /* tcc_add_bcheck tries to relocate a call to __bound_init in _init so
1390 libtcc1.a must be loaded before for __bound_init to be defined and
1391 crtn.o must be loaded after to not finalize _init too early. */
1392 tcc_add_bcheck(s1);
1393
1394 if (!s1->nostdlib) {
1395 /* add crt end if not memory output */
1396 if (s1->output_type != TCC_OUTPUT_MEMORY)
1397 tcc_add_crt(s1, "crtn.o");
1398 }
1399 }
1400
1401 /* add various standard linker symbols (must be done after the
1402 sections are filled (for example after allocating common
1403 symbols)) */
1404 ST_FUNC void tcc_add_linker_symbols(TCCState *s1)
1405 {
1406 char buf[1024];
1407 int i;
1408 Section *s;
1409
1410 add_elf_sym(symtab_section,
1411 text_section->data_offset, 0,
1412 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1413 text_section->sh_num, "_etext");
1414 add_elf_sym(symtab_section,
1415 data_section->data_offset, 0,
1416 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1417 data_section->sh_num, "_edata");
1418 add_elf_sym(symtab_section,
1419 bss_section->data_offset, 0,
1420 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1421 bss_section->sh_num, "_end");
1422 /* horrible new standard ldscript defines */
1423 add_init_array_defines(s1, ".preinit_array");
1424 add_init_array_defines(s1, ".init_array");
1425 add_init_array_defines(s1, ".fini_array");
1426
1427 /* add start and stop symbols for sections whose name can be
1428 expressed in C */
1429 for(i = 1; i < s1->nb_sections; i++) {
1430 s = s1->sections[i];
1431 if (s->sh_type == SHT_PROGBITS &&
1432 (s->sh_flags & SHF_ALLOC)) {
1433 const char *p;
1434 int ch;
1435
1436 /* check if section name can be expressed in C */
1437 p = s->name;
1438 for(;;) {
1439 ch = *p;
1440 if (!ch)
1441 break;
1442 if (!isid(ch) && !isnum(ch))
1443 goto next_sec;
1444 p++;
1445 }
1446 snprintf(buf, sizeof(buf), "__start_%s", s->name);
1447 add_elf_sym(symtab_section,
1448 0, 0,
1449 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1450 s->sh_num, buf);
1451 snprintf(buf, sizeof(buf), "__stop_%s", s->name);
1452 add_elf_sym(symtab_section,
1453 s->data_offset, 0,
1454 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1455 s->sh_num, buf);
1456 }
1457 next_sec: ;
1458 }
1459 }
1460
1461 static void tcc_output_binary(TCCState *s1, FILE *f,
1462 const int *sec_order)
1463 {
1464 Section *s;
1465 int i, offset, size;
1466
1467 offset = 0;
1468 for(i=1;i<s1->nb_sections;i++) {
1469 s = s1->sections[sec_order[i]];
1470 if (s->sh_type != SHT_NOBITS &&
1471 (s->sh_flags & SHF_ALLOC)) {
1472 while (offset < s->sh_offset) {
1473 fputc(0, f);
1474 offset++;
1475 }
1476 size = s->sh_size;
1477 fwrite(s->data, 1, size, f);
1478 offset += size;
1479 }
1480 }
1481 }
1482
1483 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1484 #define HAVE_PHDR 1
1485 #define EXTRA_RELITEMS 14
1486
1487 /* move the relocation value from .dynsym to .got */
1488 void patch_dynsym_undef(TCCState *s1, Section *s)
1489 {
1490 uint32_t *gotd = (void *)s1->got->data;
1491 ElfW(Sym) *sym;
1492
1493 gotd += 3; /* dummy entries in .got */
1494 /* relocate symbols in .dynsym */
1495 for_each_elem(s, 1, sym, ElfW(Sym)) {
1496 if (sym->st_shndx == SHN_UNDEF) {
1497 *gotd++ = sym->st_value + 6; /* XXX 6 is magic ? */
1498 sym->st_value = 0;
1499 }
1500 }
1501 }
1502 #else
1503 #define HAVE_PHDR 0
1504 #define EXTRA_RELITEMS 9
1505
1506 /* zero plt offsets of weak symbols in .dynsym */
1507 void patch_dynsym_undef(TCCState *s1, Section *s)
1508 {
1509 ElfW(Sym) *sym;
1510
1511 for_each_elem(s, 1, sym, ElfW(Sym))
1512 if (sym->st_shndx == SHN_UNDEF && ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
1513 sym->st_value = 0;
1514 }
1515 #endif
1516
1517 ST_FUNC void fill_got_entry(TCCState *s1, ElfW_Rel *rel)
1518 {
1519 int sym_index = ELFW(R_SYM) (rel->r_info);
1520 ElfW(Sym) *sym = &((ElfW(Sym) *) symtab_section->data)[sym_index];
1521 unsigned long offset;
1522
1523 if (sym_index >= s1->nb_sym_attrs)
1524 return;
1525 offset = s1->sym_attrs[sym_index].got_offset;
1526 section_reserve(s1->got, offset + PTR_SIZE);
1527 #ifdef TCC_TARGET_X86_64
1528 /* only works for x86-64 */
1529 put32(s1->got->data + offset + 4, sym->st_value >> 32);
1530 #endif
1531 put32(s1->got->data + offset, sym->st_value & 0xffffffff);
1532 }
1533
1534 /* Perform relocation to GOT or PLT entries */
1535 ST_FUNC void fill_got(TCCState *s1)
1536 {
1537 Section *s;
1538 ElfW_Rel *rel;
1539 int i;
1540
1541 for(i = 1; i < s1->nb_sections; i++) {
1542 s = s1->sections[i];
1543 if (s->sh_type != SHT_RELX)
1544 continue;
1545 /* no need to handle got relocations */
1546 if (s->link != symtab_section)
1547 continue;
1548 for_each_elem(s, 0, rel, ElfW_Rel) {
1549 switch (ELFW(R_TYPE) (rel->r_info)) {
1550 case R_X86_64_GOT32:
1551 case R_X86_64_GOTPCREL:
1552 case R_X86_64_PLT32:
1553 fill_got_entry(s1, rel);
1554 break;
1555 }
1556 }
1557 }
1558 }
1559
1560 /* Bind symbols of executable: resolve undefined symbols from exported symbols
1561 in shared libraries and export non local defined symbols to shared libraries
1562 if -rdynamic switch was given on command line */
1563 static void bind_exe_dynsyms(TCCState *s1)
1564 {
1565 const char *name;
1566 int sym_index, index;
1567 ElfW(Sym) *sym, *esym;
1568 int type;
1569
1570 /* Resolve undefined symbols from dynamic symbols. When there is a match:
1571 - if STT_FUNC or STT_GNU_IFUNC symbol -> add it in PLT
1572 - if STT_OBJECT symbol -> add it in .bss section with suitable reloc */
1573 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
1574 if (sym->st_shndx == SHN_UNDEF) {
1575 name = (char *) symtab_section->link->data + sym->st_name;
1576 sym_index = find_elf_sym(s1->dynsymtab_section, name);
1577 if (sym_index) {
1578 esym = &((ElfW(Sym) *)s1->dynsymtab_section->data)[sym_index];
1579 type = ELFW(ST_TYPE)(esym->st_info);
1580 if ((type == STT_FUNC) || (type == STT_GNU_IFUNC)) {
1581 /* Indirect functions shall have STT_FUNC type in executable
1582 * dynsym section. Indeed, a dlsym call following a lazy
1583 * resolution would pick the symbol value from the
1584 * executable dynsym entry which would contain the address
1585 * of the function wanted by the caller of dlsym instead of
1586 * the address of the function that would return that
1587 * address */
1588 put_got_entry(s1, R_JMP_SLOT, esym->st_size,
1589 ELFW(ST_INFO)(STB_GLOBAL,STT_FUNC),
1590 sym - (ElfW(Sym) *)symtab_section->data);
1591 } else if (type == STT_OBJECT) {
1592 unsigned long offset;
1593 ElfW(Sym) *dynsym;
1594 offset = bss_section->data_offset;
1595 /* XXX: which alignment ? */
1596 offset = (offset + 16 - 1) & -16;
1597 index = put_elf_sym(s1->dynsym, offset, esym->st_size,
1598 esym->st_info, 0, bss_section->sh_num,
1599 name);
1600 /* Ensure R_COPY works for weak symbol aliases */
1601 if (ELFW(ST_BIND)(esym->st_info) == STB_WEAK) {
1602 for_each_elem(s1->dynsymtab_section, 1, dynsym, ElfW(Sym)) {
1603 if ((dynsym->st_value == esym->st_value)
1604 && (ELFW(ST_BIND)(dynsym->st_info) == STB_GLOBAL)) {
1605 char *dynname = (char *) s1->dynsymtab_section->link->data
1606 + dynsym->st_name;
1607 put_elf_sym(s1->dynsym, offset, dynsym->st_size,
1608 dynsym->st_info, 0,
1609 bss_section->sh_num, dynname);
1610 break;
1611 }
1612 }
1613 }
1614 put_elf_reloc(s1->dynsym, bss_section,
1615 offset, R_COPY, index);
1616 offset += esym->st_size;
1617 bss_section->data_offset = offset;
1618 }
1619 } else {
1620 /* STB_WEAK undefined symbols are accepted */
1621 /* XXX: _fp_hw seems to be part of the ABI, so we ignore it */
1622 if (ELFW(ST_BIND)(sym->st_info) == STB_WEAK ||
1623 !strcmp(name, "_fp_hw")) {
1624 } else {
1625 tcc_error_noabort("undefined symbol '%s'", name);
1626 }
1627 }
1628 } else if (s1->rdynamic && ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
1629 /* if -rdynamic option, then export all non local symbols */
1630 name = (char *) symtab_section->link->data + sym->st_name;
1631 put_elf_sym(s1->dynsym, sym->st_value, sym->st_size, sym->st_info,
1632 0, sym->st_shndx, name);
1633 }
1634 }
1635 }
1636
1637 /* Bind symbols of libraries: export non local symbols of executable that
1638 resolve undefined symbols of shared libraries */
1639 static void bind_libs_dynsyms(TCCState *s1)
1640 {
1641 const char *name;
1642 int sym_index;
1643 ElfW(Sym) *sym, *esym;
1644
1645 /* now look at unresolved dynamic symbols and export
1646 corresponding symbol */
1647 for_each_elem(s1->dynsymtab_section, 1, esym, ElfW(Sym)) {
1648 if (esym->st_shndx == SHN_UNDEF) {
1649 name = (char *) s1->dynsymtab_section->link->data + esym->st_name;
1650 sym_index = find_elf_sym(symtab_section, name);
1651 if (sym_index) {
1652 /* XXX: avoid adding a symbol if already present because of
1653 -rdynamic ? */
1654 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1655 put_elf_sym(s1->dynsym, sym->st_value, sym->st_size,
1656 sym->st_info, 0, sym->st_shndx, name);
1657 } else {
1658 /* weak symbols can stay undefined */
1659 if (ELFW(ST_BIND)(esym->st_info) != STB_WEAK)
1660 tcc_warning("undefined dynamic symbol '%s'", name);
1661 }
1662 }
1663 }
1664 }
1665
1666 /* Export all non local symbols (for shared libraries) */
1667 static void export_global_syms(TCCState *s1)
1668 {
1669 int nb_syms, dynindex, index;
1670 const char *name;
1671 ElfW(Sym) *sym;
1672
1673 nb_syms = symtab_section->data_offset / sizeof(ElfW(Sym));
1674 s1->symtab_to_dynsym = tcc_mallocz(sizeof(int) * nb_syms);
1675 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
1676 if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
1677 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
1678 int type = ELFW(ST_TYPE)(sym->st_info);
1679 if ((type == STT_FUNC || type == STT_GNU_IFUNC)
1680 && sym->st_shndx == SHN_UNDEF) {
1681 int visibility = ELFW(ST_BIND)(sym->st_info);
1682 put_got_entry(s1, R_JMP_SLOT, sym->st_size,
1683 ELFW(ST_INFO)(visibility, STT_FUNC),
1684 sym - (ElfW(Sym) *) symtab_section->data);
1685 } else if (type == STT_OBJECT) {
1686 put_got_entry(s1, R_X86_64_GLOB_DAT, sym->st_size, sym->st_info,
1687 sym - (ElfW(Sym) *) symtab_section->data);
1688 } else
1689 #endif
1690 {
1691 name = (char *) symtab_section->link->data + sym->st_name;
1692 dynindex = put_elf_sym(s1->dynsym, sym->st_value, sym->st_size,
1693 sym->st_info, 0, sym->st_shndx, name);
1694 index = sym - (ElfW(Sym) *) symtab_section->data;
1695 s1->symtab_to_dynsym[index] = dynindex;
1696 }
1697 }
1698 }
1699 }
1700
1701 /* relocate the PLT: compute addresses and offsets in the PLT now that final
1702 address for PLT and GOT are known (see fill_program_header) */
1703 static void relocate_plt(TCCState *s1)
1704 {
1705 uint8_t *p, *p_end;
1706
1707 p = s1->plt->data;
1708 p_end = p + s1->plt->data_offset;
1709 if (p < p_end) {
1710 #if defined(TCC_TARGET_I386)
1711 put32(p + 2, get32(p + 2) + s1->got->sh_addr);
1712 put32(p + 8, get32(p + 8) + s1->got->sh_addr);
1713 p += 16;
1714 while (p < p_end) {
1715 put32(p + 2, get32(p + 2) + s1->got->sh_addr);
1716 p += 16;
1717 }
1718 #elif defined(TCC_TARGET_X86_64)
1719 int x = s1->got->sh_addr - s1->plt->sh_addr - 6;
1720 put32(p + 2, get32(p + 2) + x);
1721 put32(p + 8, get32(p + 8) + x - 6);
1722 p += 16;
1723 while (p < p_end) {
1724 put32(p + 2, get32(p + 2) + x + s1->plt->data - p);
1725 p += 16;
1726 }
1727 #elif defined(TCC_TARGET_ARM)
1728 int x;
1729 x=s1->got->sh_addr - s1->plt->sh_addr - 12;
1730 p += 16;
1731 while (p < p_end) {
1732 if (get32(p) == 0x46c04778) /* PLT Thumb stub present */
1733 p += 4;
1734 put32(p + 12, x + get32(p + 12) + s1->plt->data - p);
1735 p += 16;
1736 }
1737 #elif defined(TCC_TARGET_C67)
1738 /* XXX: TODO */
1739 #else
1740 #error unsupported CPU
1741 #endif
1742 }
1743 }
1744
1745 /* Allocate strings for section names and decide if an unallocated section
1746 should be output.
1747
1748 NOTE: the strsec section comes last, so its size is also correct ! */
1749 static void alloc_sec_names(TCCState *s1, int file_type, Section *strsec)
1750 {
1751 int i;
1752 Section *s;
1753
1754 /* Allocate strings for section names */
1755 for(i = 1; i < s1->nb_sections; i++) {
1756 s = s1->sections[i];
1757 s->sh_name = put_elf_str(strsec, s->name);
1758 /* when generating a DLL, we include relocations but we may
1759 patch them */
1760 if (file_type == TCC_OUTPUT_DLL &&
1761 s->sh_type == SHT_RELX &&
1762 !(s->sh_flags & SHF_ALLOC)) {
1763 /* gr: avoid bogus relocs for empty (debug) sections */
1764 if (s1->sections[s->sh_info]->sh_flags & SHF_ALLOC)
1765 prepare_dynamic_rel(s1, s);
1766 else if (s1->do_debug)
1767 s->sh_size = s->data_offset;
1768 } else if (s1->do_debug ||
1769 file_type == TCC_OUTPUT_OBJ ||
1770 (s->sh_flags & SHF_ALLOC) ||
1771 i == (s1->nb_sections - 1)) {
1772 /* we output all sections if debug or object file */
1773 s->sh_size = s->data_offset;
1774 }
1775 }
1776 }
1777
1778 /* Info to be copied in dynamic section */
1779 struct dyn_inf {
1780 Section *dynamic;
1781 Section *dynstr;
1782 unsigned long dyn_rel_off;
1783 addr_t rel_addr;
1784 addr_t rel_size;
1785 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1786 addr_t bss_addr;
1787 addr_t bss_size;
1788 #endif
1789 };
1790
1791 /* Assign sections to segments and decide how are sections laid out when loaded
1792 in memory. This function also fills corresponding program headers. */
1793 static int layout_sections(TCCState *s1, ElfW(Phdr) *phdr, int phnum,
1794 Section *interp, struct dyn_inf *dyninf,
1795 int *sec_order)
1796 {
1797 int i, j, k, file_type, sh_order_index, file_offset;
1798 long long tmp;
1799 addr_t addr;
1800 ElfW(Phdr) *ph;
1801 Section *s;
1802
1803 file_type = s1->output_type;
1804 sh_order_index = 1;
1805 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF)
1806 file_offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr));
1807 else
1808 file_offset = 0;
1809
1810 if (phnum > 0) {
1811 if (s1->has_text_addr) {
1812 int a_offset, p_offset;
1813 addr = s1->text_addr;
1814 /* we ensure that (addr % ELF_PAGE_SIZE) == file_offset %
1815 ELF_PAGE_SIZE */
1816 a_offset = (int) (addr & (s1->section_align - 1));
1817 p_offset = file_offset & (s1->section_align - 1);
1818 if (a_offset < p_offset)
1819 a_offset += s1->section_align;
1820 file_offset += (a_offset - p_offset);
1821 } else {
1822 if (file_type == TCC_OUTPUT_DLL)
1823 addr = 0;
1824 else
1825 addr = ELF_START_ADDR;
1826 /* compute address after headers */
1827 addr += (file_offset & (s1->section_align - 1));
1828 }
1829
1830 ph = &phdr[0];
1831 /* Leave one program headers for the program interpreter and one for
1832 the program header table itself if needed. These are done later as
1833 they require section layout to be done first. */
1834 if (interp)
1835 ph += 1 + HAVE_PHDR;
1836
1837 /* dynamic relocation table information, for .dynamic section */
1838 dyninf->rel_addr = dyninf->rel_size = 0;
1839 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1840 dyninf->bss_addr = dyninf->bss_size = 0;
1841 #endif
1842
1843 for(j = 0; j < 2; j++) {
1844 ph->p_type = PT_LOAD;
1845 if (j == 0)
1846 ph->p_flags = PF_R | PF_X;
1847 else
1848 ph->p_flags = PF_R | PF_W;
1849 ph->p_align = s1->section_align;
1850
1851 /* Decide the layout of sections loaded in memory. This must
1852 be done before program headers are filled since they contain
1853 info about the layout. We do the following ordering: interp,
1854 symbol tables, relocations, progbits, nobits */
1855 /* XXX: do faster and simpler sorting */
1856 for(k = 0; k < 5; k++) {
1857 for(i = 1; i < s1->nb_sections; i++) {
1858 s = s1->sections[i];
1859 /* compute if section should be included */
1860 if (j == 0) {
1861 if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) !=
1862 SHF_ALLOC)
1863 continue;
1864 } else {
1865 if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) !=
1866 (SHF_ALLOC | SHF_WRITE))
1867 continue;
1868 }
1869 if (s == interp) {
1870 if (k != 0)
1871 continue;
1872 } else if (s->sh_type == SHT_DYNSYM ||
1873 s->sh_type == SHT_STRTAB ||
1874 s->sh_type == SHT_HASH) {
1875 if (k != 1)
1876 continue;
1877 } else if (s->sh_type == SHT_RELX) {
1878 if (k != 2)
1879 continue;
1880 } else if (s->sh_type == SHT_NOBITS) {
1881 if (k != 4)
1882 continue;
1883 } else {
1884 if (k != 3)
1885 continue;
1886 }
1887 sec_order[sh_order_index++] = i;
1888
1889 /* section matches: we align it and add its size */
1890 tmp = addr;
1891 addr = (addr + s->sh_addralign - 1) &
1892 ~(s->sh_addralign - 1);
1893 file_offset += (int) ( addr - tmp );
1894 s->sh_offset = file_offset;
1895 s->sh_addr = addr;
1896
1897 /* update program header infos */
1898 if (ph->p_offset == 0) {
1899 ph->p_offset = file_offset;
1900 ph->p_vaddr = addr;
1901 ph->p_paddr = ph->p_vaddr;
1902 }
1903 /* update dynamic relocation infos */
1904 if (s->sh_type == SHT_RELX) {
1905 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1906 if (!strcmp(strsec->data + s->sh_name, ".rel.got")) {
1907 dyninf->rel_addr = addr;
1908 dyninf->rel_size += s->sh_size; /* XXX only first rel. */
1909 }
1910 if (!strcmp(strsec->data + s->sh_name, ".rel.bss")) {
1911 dyninf->bss_addr = addr;
1912 dyninf->bss_size = s->sh_size; /* XXX only first rel. */
1913 }
1914 #else
1915 if (dyninf->rel_size == 0)
1916 dyninf->rel_addr = addr;
1917 dyninf->rel_size += s->sh_size;
1918 #endif
1919 }
1920 addr += s->sh_size;
1921 if (s->sh_type != SHT_NOBITS)
1922 file_offset += s->sh_size;
1923 }
1924 }
1925 ph->p_filesz = file_offset - ph->p_offset;
1926 ph->p_memsz = addr - ph->p_vaddr;
1927 ph++;
1928 if (j == 0) {
1929 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF) {
1930 /* if in the middle of a page, we duplicate the page in
1931 memory so that one copy is RX and the other is RW */
1932 if ((addr & (s1->section_align - 1)) != 0)
1933 addr += s1->section_align;
1934 } else {
1935 addr = (addr + s1->section_align - 1) & ~(s1->section_align - 1);
1936 file_offset = (file_offset + s1->section_align - 1) &
1937 ~(s1->section_align - 1);
1938 }
1939 }
1940 }
1941 }
1942
1943 /* all other sections come after */
1944 for(i = 1; i < s1->nb_sections; i++) {
1945 s = s1->sections[i];
1946 if (phnum > 0 && (s->sh_flags & SHF_ALLOC))
1947 continue;
1948 sec_order[sh_order_index++] = i;
1949
1950 file_offset = (file_offset + s->sh_addralign - 1) &
1951 ~(s->sh_addralign - 1);
1952 s->sh_offset = file_offset;
1953 if (s->sh_type != SHT_NOBITS)
1954 file_offset += s->sh_size;
1955 }
1956
1957 return file_offset;
1958 }
1959
1960 static void fill_unloadable_phdr(ElfW(Phdr) *phdr, int phnum, Section *interp,
1961 Section *dynamic)
1962 {
1963 ElfW(Phdr) *ph;
1964
1965 /* if interpreter, then add corresponding program header */
1966 if (interp) {
1967 ph = &phdr[0];
1968
1969 if (HAVE_PHDR)
1970 {
1971 int len = phnum * sizeof(ElfW(Phdr));
1972
1973 ph->p_type = PT_PHDR;
1974 ph->p_offset = sizeof(ElfW(Ehdr));
1975 ph->p_vaddr = interp->sh_addr - len;
1976 ph->p_paddr = ph->p_vaddr;
1977 ph->p_filesz = ph->p_memsz = len;
1978 ph->p_flags = PF_R | PF_X;
1979 ph->p_align = 4; /* interp->sh_addralign; */
1980 ph++;
1981 }
1982
1983 ph->p_type = PT_INTERP;
1984 ph->p_offset = interp->sh_offset;
1985 ph->p_vaddr = interp->sh_addr;
1986 ph->p_paddr = ph->p_vaddr;
1987 ph->p_filesz = interp->sh_size;
1988 ph->p_memsz = interp->sh_size;
1989 ph->p_flags = PF_R;
1990 ph->p_align = interp->sh_addralign;
1991 }
1992
1993 /* if dynamic section, then add corresponding program header */
1994 if (dynamic) {
1995 ph = &phdr[phnum - 1];
1996
1997 ph->p_type = PT_DYNAMIC;
1998 ph->p_offset = dynamic->sh_offset;
1999 ph->p_vaddr = dynamic->sh_addr;
2000 ph->p_paddr = ph->p_vaddr;
2001 ph->p_filesz = dynamic->sh_size;
2002 ph->p_memsz = dynamic->sh_size;
2003 ph->p_flags = PF_R | PF_W;
2004 ph->p_align = dynamic->sh_addralign;
2005 }
2006 }
2007
2008 /* Fill the dynamic section with tags describing the address and size of
2009 sections */
2010 static void fill_dynamic(TCCState *s1, struct dyn_inf *dyninf)
2011 {
2012 Section *dynamic;
2013
2014 dynamic = dyninf->dynamic;
2015
2016 /* put dynamic section entries */
2017 dynamic->data_offset = dyninf->dyn_rel_off;
2018 put_dt(dynamic, DT_HASH, s1->dynsym->hash->sh_addr);
2019 put_dt(dynamic, DT_STRTAB, dyninf->dynstr->sh_addr);
2020 put_dt(dynamic, DT_SYMTAB, s1->dynsym->sh_addr);
2021 put_dt(dynamic, DT_STRSZ, dyninf->dynstr->data_offset);
2022 put_dt(dynamic, DT_SYMENT, sizeof(ElfW(Sym)));
2023 #ifdef TCC_TARGET_X86_64
2024 put_dt(dynamic, DT_RELA, dyninf->rel_addr);
2025 put_dt(dynamic, DT_RELASZ, dyninf->rel_size);
2026 put_dt(dynamic, DT_RELAENT, sizeof(ElfW_Rel));
2027 #else
2028 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2029 put_dt(dynamic, DT_PLTGOT, s1->got->sh_addr);
2030 put_dt(dynamic, DT_PLTRELSZ, dyninf->rel_size);
2031 put_dt(dynamic, DT_JMPREL, dyninf->rel_addr);
2032 put_dt(dynamic, DT_PLTREL, DT_REL);
2033 put_dt(dynamic, DT_REL, dyninf->bss_addr);
2034 put_dt(dynamic, DT_RELSZ, dyninf->bss_size);
2035 #else
2036 put_dt(dynamic, DT_REL, dyninf->rel_addr);
2037 put_dt(dynamic, DT_RELSZ, dyninf->rel_size);
2038 put_dt(dynamic, DT_RELENT, sizeof(ElfW_Rel));
2039 #endif
2040 #endif
2041 if (s1->do_debug)
2042 put_dt(dynamic, DT_DEBUG, 0);
2043 put_dt(dynamic, DT_NULL, 0);
2044 }
2045
2046 /* Relocate remaining sections and symbols (that is those not related to
2047 dynamic linking) */
2048 static int final_sections_reloc(TCCState *s1)
2049 {
2050 int i;
2051 Section *s;
2052
2053 relocate_syms(s1, 0);
2054
2055 if (s1->nb_errors != 0)
2056 return -1;
2057
2058 /* relocate sections */
2059 /* XXX: ignore sections with allocated relocations ? */
2060 for(i = 1; i < s1->nb_sections; i++) {
2061 s = s1->sections[i];
2062 if (s->reloc && s != s1->got)
2063 relocate_section(s1, s);
2064 }
2065
2066 /* relocate relocation entries if the relocation tables are
2067 allocated in the executable */
2068 for(i = 1; i < s1->nb_sections; i++) {
2069 s = s1->sections[i];
2070 if ((s->sh_flags & SHF_ALLOC) &&
2071 s->sh_type == SHT_RELX) {
2072 relocate_rel(s1, s);
2073 }
2074 }
2075 return 0;
2076 }
2077
2078 /* Create an ELF file on disk.
2079 This function handle ELF specific layout requirements */
2080 static void tcc_output_elf(TCCState *s1, FILE *f, int phnum, ElfW(Phdr) *phdr,
2081 int file_offset, int *sec_order)
2082 {
2083 int i, shnum, offset, size, file_type;
2084 Section *s;
2085 ElfW(Ehdr) ehdr;
2086 ElfW(Shdr) shdr, *sh;
2087
2088 file_type = s1->output_type;
2089 shnum = s1->nb_sections;
2090
2091 memset(&ehdr, 0, sizeof(ehdr));
2092
2093 if (phnum > 0) {
2094 ehdr.e_phentsize = sizeof(ElfW(Phdr));
2095 ehdr.e_phnum = phnum;
2096 ehdr.e_phoff = sizeof(ElfW(Ehdr));
2097 }
2098
2099 /* align to 4 */
2100 file_offset = (file_offset + 3) & -4;
2101
2102 /* fill header */
2103 ehdr.e_ident[0] = ELFMAG0;
2104 ehdr.e_ident[1] = ELFMAG1;
2105 ehdr.e_ident[2] = ELFMAG2;
2106 ehdr.e_ident[3] = ELFMAG3;
2107 ehdr.e_ident[4] = ELFCLASSW;
2108 ehdr.e_ident[5] = ELFDATA2LSB;
2109 ehdr.e_ident[6] = EV_CURRENT;
2110 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2111 ehdr.e_ident[EI_OSABI] = ELFOSABI_FREEBSD;
2112 #endif
2113 #ifdef TCC_TARGET_ARM
2114 #ifdef TCC_ARM_EABI
2115 ehdr.e_ident[EI_OSABI] = 0;
2116 ehdr.e_flags = EF_ARM_EABI_VER4;
2117 if (file_type == TCC_OUTPUT_EXE || file_type == TCC_OUTPUT_DLL)
2118 ehdr.e_flags |= EF_ARM_HASENTRY;
2119 if (s1->float_abi == ARM_HARD_FLOAT)
2120 ehdr.e_flags |= EF_ARM_VFP_FLOAT;
2121 else
2122 ehdr.e_flags |= EF_ARM_SOFT_FLOAT;
2123 #else
2124 ehdr.e_ident[EI_OSABI] = ELFOSABI_ARM;
2125 #endif
2126 #endif
2127 switch(file_type) {
2128 default:
2129 case TCC_OUTPUT_EXE:
2130 ehdr.e_type = ET_EXEC;
2131 ehdr.e_entry = get_elf_sym_addr(s1, "_start", 1);
2132 break;
2133 case TCC_OUTPUT_DLL:
2134 ehdr.e_type = ET_DYN;
2135 ehdr.e_entry = text_section->sh_addr; /* XXX: is it correct ? */
2136 break;
2137 case TCC_OUTPUT_OBJ:
2138 ehdr.e_type = ET_REL;
2139 break;
2140 }
2141 ehdr.e_machine = EM_TCC_TARGET;
2142 ehdr.e_version = EV_CURRENT;
2143 ehdr.e_shoff = file_offset;
2144 ehdr.e_ehsize = sizeof(ElfW(Ehdr));
2145 ehdr.e_shentsize = sizeof(ElfW(Shdr));
2146 ehdr.e_shnum = shnum;
2147 ehdr.e_shstrndx = shnum - 1;
2148
2149 fwrite(&ehdr, 1, sizeof(ElfW(Ehdr)), f);
2150 fwrite(phdr, 1, phnum * sizeof(ElfW(Phdr)), f);
2151 offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr));
2152
2153 sort_syms(s1, symtab_section);
2154 for(i = 1; i < s1->nb_sections; i++) {
2155 s = s1->sections[sec_order[i]];
2156 if (s->sh_type != SHT_NOBITS) {
2157 if (s->sh_type == SHT_DYNSYM)
2158 patch_dynsym_undef(s1, s);
2159 while (offset < s->sh_offset) {
2160 fputc(0, f);
2161 offset++;
2162 }
2163 size = s->sh_size;
2164 fwrite(s->data, 1, size, f);
2165 offset += size;
2166 }
2167 }
2168
2169 /* output section headers */
2170 while (offset < ehdr.e_shoff) {
2171 fputc(0, f);
2172 offset++;
2173 }
2174
2175 for(i = 0; i < s1->nb_sections; i++) {
2176 sh = &shdr;
2177 memset(sh, 0, sizeof(ElfW(Shdr)));
2178 s = s1->sections[i];
2179 if (s) {
2180 sh->sh_name = s->sh_name;
2181 sh->sh_type = s->sh_type;
2182 sh->sh_flags = s->sh_flags;
2183 sh->sh_entsize = s->sh_entsize;
2184 sh->sh_info = s->sh_info;
2185 if (s->link)
2186 sh->sh_link = s->link->sh_num;
2187 sh->sh_addralign = s->sh_addralign;
2188 sh->sh_addr = s->sh_addr;
2189 sh->sh_offset = s->sh_offset;
2190 sh->sh_size = s->sh_size;
2191 }
2192 fwrite(sh, 1, sizeof(ElfW(Shdr)), f);
2193 }
2194 }
2195
2196 /* Write an elf, coff or "binary" file */
2197 static int tcc_write_elf_file(TCCState *s1, const char *filename, int phnum,
2198 ElfW(Phdr) *phdr, int file_offset, int *sec_order)
2199 {
2200 int fd, mode, file_type;
2201 FILE *f;
2202
2203 file_type = s1->output_type;
2204 if (file_type == TCC_OUTPUT_OBJ)
2205 mode = 0666;
2206 else
2207 mode = 0777;
2208 unlink(filename);
2209 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, mode);
2210 if (fd < 0) {
2211 tcc_error_noabort("could not write '%s'", filename);
2212 return -1;
2213 }
2214 f = fdopen(fd, "wb");
2215 if (s1->verbose)
2216 printf("<- %s\n", filename);
2217
2218 #ifdef TCC_TARGET_COFF
2219 if (s1->output_format == TCC_OUTPUT_FORMAT_COFF)
2220 tcc_output_coff(s1, f);
2221 else
2222 #endif
2223 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF)
2224 tcc_output_elf(s1, f, phnum, phdr, file_offset, sec_order);
2225 else
2226 tcc_output_binary(s1, f, sec_order);
2227 fclose(f);
2228
2229 return 0;
2230 }
2231
2232 /* Output an elf, coff or binary file */
2233 /* XXX: suppress unneeded sections */
2234 static int elf_output_file(TCCState *s1, const char *filename)
2235 {
2236 int i, ret, phnum, shnum, file_type, file_offset, *sec_order;
2237 struct dyn_inf dyninf;
2238 ElfW(Phdr) *phdr;
2239 ElfW(Sym) *sym;
2240 Section *strsec, *interp, *dynamic, *dynstr;
2241
2242 file_type = s1->output_type;
2243 s1->nb_errors = 0;
2244
2245 /* if linking, also link in runtime libraries (libc, libgcc, etc.) */
2246 if (file_type != TCC_OUTPUT_OBJ) {
2247 tcc_add_runtime(s1);
2248 }
2249
2250 phdr = NULL;
2251 sec_order = NULL;
2252 interp = dynamic = dynstr = NULL; /* avoid warning */
2253 dyninf.dyn_rel_off = 0; /* avoid warning */
2254
2255 if (file_type != TCC_OUTPUT_OBJ) {
2256 relocate_common_syms();
2257
2258 tcc_add_linker_symbols(s1);
2259
2260 if (!s1->static_link) {
2261 if (file_type == TCC_OUTPUT_EXE) {
2262 char *ptr;
2263 /* allow override the dynamic loader */
2264 const char *elfint = getenv("LD_SO");
2265 if (elfint == NULL)
2266 elfint = DEFAULT_ELFINTERP(s1);
2267 /* add interpreter section only if executable */
2268 interp = new_section(s1, ".interp", SHT_PROGBITS, SHF_ALLOC);
2269 interp->sh_addralign = 1;
2270 ptr = section_ptr_add(interp, 1 + strlen(elfint));
2271 strcpy(ptr, elfint);
2272 }
2273
2274 /* add dynamic symbol table */
2275 s1->dynsym = new_symtab(s1, ".dynsym", SHT_DYNSYM, SHF_ALLOC,
2276 ".dynstr",
2277 ".hash", SHF_ALLOC);
2278 dynstr = s1->dynsym->link;
2279
2280 /* add dynamic section */
2281 dynamic = new_section(s1, ".dynamic", SHT_DYNAMIC,
2282 SHF_ALLOC | SHF_WRITE);
2283 dynamic->link = dynstr;
2284 dynamic->sh_entsize = sizeof(ElfW(Dyn));
2285
2286 /* add PLT */
2287 s1->plt = new_section(s1, ".plt", SHT_PROGBITS,
2288 SHF_ALLOC | SHF_EXECINSTR);
2289 s1->plt->sh_entsize = 4;
2290
2291 build_got(s1);
2292
2293 if (file_type == TCC_OUTPUT_EXE) {
2294 bind_exe_dynsyms(s1);
2295
2296 if (s1->nb_errors) {
2297 ret = -1;
2298 goto the_end;
2299 }
2300
2301 bind_libs_dynsyms(s1);
2302 } else /* shared library case: simply export all global symbols */
2303 export_global_syms(s1);
2304
2305 build_got_entries(s1);
2306
2307 /* add a list of needed dlls */
2308 for(i = 0; i < s1->nb_loaded_dlls; i++) {
2309 DLLReference *dllref = s1->loaded_dlls[i];
2310 if (dllref->level == 0)
2311 put_dt(dynamic, DT_NEEDED, put_elf_str(dynstr, dllref->name));
2312 }
2313
2314 if (s1->rpath)
2315 put_dt(dynamic, DT_RPATH, put_elf_str(dynstr, s1->rpath));
2316
2317 /* XXX: currently, since we do not handle PIC code, we
2318 must relocate the readonly segments */
2319 if (file_type == TCC_OUTPUT_DLL) {
2320 if (s1->soname)
2321 put_dt(dynamic, DT_SONAME, put_elf_str(dynstr, s1->soname));
2322 put_dt(dynamic, DT_TEXTREL, 0);
2323 }
2324
2325 if (s1->symbolic)
2326 put_dt(dynamic, DT_SYMBOLIC, 0);
2327
2328 /* add necessary space for other entries */
2329 dyninf.dyn_rel_off = dynamic->data_offset;
2330 dynamic->data_offset += sizeof(ElfW(Dyn)) * EXTRA_RELITEMS;
2331 } else {
2332 /* still need to build got entries in case of static link */
2333 build_got_entries(s1);
2334 }
2335 }
2336
2337 /* we add a section for symbols */
2338 strsec = new_section(s1, ".shstrtab", SHT_STRTAB, 0);
2339 put_elf_str(strsec, "");
2340
2341 /* compute number of sections */
2342 shnum = s1->nb_sections;
2343
2344 /* this array is used to reorder sections in the output file */
2345 sec_order = tcc_malloc(sizeof(int) * shnum);
2346 sec_order[0] = 0;
2347
2348 /* compute number of program headers */
2349 switch(file_type) {
2350 default:
2351 case TCC_OUTPUT_OBJ:
2352 phnum = 0;
2353 break;
2354 case TCC_OUTPUT_EXE:
2355 if (!s1->static_link)
2356 phnum = 4 + HAVE_PHDR;
2357 else
2358 phnum = 2;
2359 break;
2360 case TCC_OUTPUT_DLL:
2361 phnum = 3;
2362 break;
2363 }
2364
2365 /* Allocate strings for section names */
2366 alloc_sec_names(s1, file_type, strsec);
2367
2368 /* allocate program segment headers */
2369 phdr = tcc_mallocz(phnum * sizeof(ElfW(Phdr)));
2370
2371 /* compute section to program header mapping */
2372 file_offset = layout_sections(s1, phdr, phnum, interp, &dyninf, sec_order);
2373
2374 /* Fill remaining program header and finalize relocation related to dynamic
2375 linking. */
2376 if (phnum > 0) {
2377 fill_unloadable_phdr(phdr, phnum, interp, dynamic);
2378 if (dynamic) {
2379 dyninf.dynamic = dynamic;
2380 dyninf.dynstr = dynstr;
2381
2382 fill_dynamic(s1, &dyninf);
2383
2384 /* put in GOT the dynamic section address and relocate PLT */
2385 put32(s1->got->data, dynamic->sh_addr);
2386 if (file_type == TCC_OUTPUT_EXE
2387 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
2388 || file_type == TCC_OUTPUT_DLL
2389 #endif
2390 )
2391 relocate_plt(s1);
2392
2393 /* relocate symbols in .dynsym now that final addresses are known */
2394 for_each_elem(s1->dynsym, 1, sym, ElfW(Sym)) {
2395 /* relocate to PLT if symbol corresponds to a PLT entry */
2396 if (sym->st_shndx == SHN_UNDEF) {
2397 if (sym->st_value)
2398 sym->st_value += s1->plt->sh_addr;
2399 } else if (sym->st_shndx < SHN_LORESERVE) {
2400 /* do symbol relocation */
2401 sym->st_value += s1->sections[sym->st_shndx]->sh_addr;
2402 }
2403 }
2404 }
2405 }
2406
2407 /* if building executable or DLL, then relocate each section
2408 except the GOT which is already relocated */
2409 if (file_type != TCC_OUTPUT_OBJ) {
2410 ret = final_sections_reloc(s1);
2411 if (ret)
2412 goto the_end;
2413 }
2414
2415 /* Perform relocation to GOT or PLT entries */
2416 if (file_type == TCC_OUTPUT_EXE && s1->static_link)
2417 fill_got(s1);
2418
2419 /* Create the ELF file with name 'filename' */
2420 ret = tcc_write_elf_file(s1, filename, phnum, phdr, file_offset, sec_order);
2421 the_end:
2422 tcc_free(s1->symtab_to_dynsym);
2423 tcc_free(sec_order);
2424 tcc_free(phdr);
2425 tcc_free(s1->sym_attrs);
2426 return ret;
2427 }
2428
2429 LIBTCCAPI int tcc_output_file(TCCState *s, const char *filename)
2430 {
2431 int ret;
2432 #ifdef TCC_TARGET_PE
2433 if (s->output_type != TCC_OUTPUT_OBJ) {
2434 ret = pe_output_file(s, filename);
2435 } else
2436 #endif
2437 ret = elf_output_file(s, filename);
2438 return ret;
2439 }
2440
2441 static void *load_data(int fd, unsigned long file_offset, unsigned long size)
2442 {
2443 void *data;
2444
2445 data = tcc_malloc(size);
2446 lseek(fd, file_offset, SEEK_SET);
2447 read(fd, data, size);
2448 return data;
2449 }
2450
2451 typedef struct SectionMergeInfo {
2452 Section *s; /* corresponding existing section */
2453 unsigned long offset; /* offset of the new section in the existing section */
2454 uint8_t new_section; /* true if section 's' was added */
2455 uint8_t link_once; /* true if link once section */
2456 } SectionMergeInfo;
2457
2458 /* load an object file and merge it with current files */
2459 /* XXX: handle correctly stab (debug) info */
2460 ST_FUNC int tcc_load_object_file(TCCState *s1,
2461 int fd, unsigned long file_offset)
2462 {
2463 ElfW(Ehdr) ehdr;
2464 ElfW(Shdr) *shdr, *sh;
2465 int size, i, j, offset, offseti, nb_syms, sym_index, ret;
2466 unsigned char *strsec, *strtab;
2467 int *old_to_new_syms;
2468 char *sh_name, *name;
2469 SectionMergeInfo *sm_table, *sm;
2470 ElfW(Sym) *sym, *symtab;
2471 ElfW_Rel *rel;
2472 Section *s;
2473
2474 int stab_index;
2475 int stabstr_index;
2476
2477 stab_index = stabstr_index = 0;
2478
2479 if (read(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr))
2480 goto fail1;
2481 if (ehdr.e_ident[0] != ELFMAG0 ||
2482 ehdr.e_ident[1] != ELFMAG1 ||
2483 ehdr.e_ident[2] != ELFMAG2 ||
2484 ehdr.e_ident[3] != ELFMAG3)
2485 goto fail1;
2486 /* test if object file */
2487 if (ehdr.e_type != ET_REL)
2488 goto fail1;
2489 /* test CPU specific stuff */
2490 if (ehdr.e_ident[5] != ELFDATA2LSB ||
2491 ehdr.e_machine != EM_TCC_TARGET) {
2492 fail1:
2493 tcc_error_noabort("invalid object file");
2494 return -1;
2495 }
2496 /* read sections */
2497 shdr = load_data(fd, file_offset + ehdr.e_shoff,
2498 sizeof(ElfW(Shdr)) * ehdr.e_shnum);
2499 sm_table = tcc_mallocz(sizeof(SectionMergeInfo) * ehdr.e_shnum);
2500
2501 /* load section names */
2502 sh = &shdr[ehdr.e_shstrndx];
2503 strsec = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2504
2505 /* load symtab and strtab */
2506 old_to_new_syms = NULL;
2507 symtab = NULL;
2508 strtab = NULL;
2509 nb_syms = 0;
2510 for(i = 1; i < ehdr.e_shnum; i++) {
2511 sh = &shdr[i];
2512 if (sh->sh_type == SHT_SYMTAB) {
2513 if (symtab) {
2514 tcc_error_noabort("object must contain only one symtab");
2515 fail:
2516 ret = -1;
2517 goto the_end;
2518 }
2519 nb_syms = sh->sh_size / sizeof(ElfW(Sym));
2520 symtab = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2521 sm_table[i].s = symtab_section;
2522
2523 /* now load strtab */
2524 sh = &shdr[sh->sh_link];
2525 strtab = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2526 }
2527 }
2528
2529 /* now examine each section and try to merge its content with the
2530 ones in memory */
2531 for(i = 1; i < ehdr.e_shnum; i++) {
2532 /* no need to examine section name strtab */
2533 if (i == ehdr.e_shstrndx)
2534 continue;
2535 sh = &shdr[i];
2536 sh_name = (char *) strsec + sh->sh_name;
2537 /* ignore sections types we do not handle */
2538 if (sh->sh_type != SHT_PROGBITS &&
2539 sh->sh_type != SHT_RELX &&
2540 #ifdef TCC_ARM_EABI
2541 sh->sh_type != SHT_ARM_EXIDX &&
2542 #endif
2543 sh->sh_type != SHT_NOBITS &&
2544 sh->sh_type != SHT_PREINIT_ARRAY &&
2545 sh->sh_type != SHT_INIT_ARRAY &&
2546 sh->sh_type != SHT_FINI_ARRAY &&
2547 strcmp(sh_name, ".stabstr")
2548 )
2549 continue;
2550 if (sh->sh_addralign < 1)
2551 sh->sh_addralign = 1;
2552 /* find corresponding section, if any */
2553 for(j = 1; j < s1->nb_sections;j++) {
2554 s = s1->sections[j];
2555 if (!strcmp(s->name, sh_name)) {
2556 if (!strncmp(sh_name, ".gnu.linkonce",
2557 sizeof(".gnu.linkonce") - 1)) {
2558 /* if a 'linkonce' section is already present, we
2559 do not add it again. It is a little tricky as
2560 symbols can still be defined in
2561 it. */
2562 sm_table[i].link_once = 1;
2563 goto next;
2564 } else {
2565 goto found;
2566 }
2567 }
2568 }
2569 /* not found: create new section */
2570 s = new_section(s1, sh_name, sh->sh_type, sh->sh_flags);
2571 /* take as much info as possible from the section. sh_link and
2572 sh_info will be updated later */
2573 s->sh_addralign = sh->sh_addralign;
2574 s->sh_entsize = sh->sh_entsize;
2575 sm_table[i].new_section = 1;
2576 found:
2577 if (sh->sh_type != s->sh_type) {
2578 tcc_error_noabort("invalid section type");
2579 goto fail;
2580 }
2581
2582 /* align start of section */
2583 offset = s->data_offset;
2584
2585 if (0 == strcmp(sh_name, ".stab")) {
2586 stab_index = i;
2587 goto no_align;
2588 }
2589 if (0 == strcmp(sh_name, ".stabstr")) {
2590 stabstr_index = i;
2591 goto no_align;
2592 }
2593
2594 size = sh->sh_addralign - 1;
2595 offset = (offset + size) & ~size;
2596 if (sh->sh_addralign > s->sh_addralign)
2597 s->sh_addralign = sh->sh_addralign;
2598 s->data_offset = offset;
2599 no_align:
2600 sm_table[i].offset = offset;
2601 sm_table[i].s = s;
2602 /* concatenate sections */
2603 size = sh->sh_size;
2604 if (sh->sh_type != SHT_NOBITS) {
2605 unsigned char *ptr;
2606 lseek(fd, file_offset + sh->sh_offset, SEEK_SET);
2607 ptr = section_ptr_add(s, size);
2608 read(fd, ptr, size);
2609 } else {
2610 s->data_offset += size;
2611 }
2612 next: ;
2613 }
2614
2615 /* gr relocate stab strings */
2616 if (stab_index && stabstr_index) {
2617 Stab_Sym *a, *b;
2618 unsigned o;
2619 s = sm_table[stab_index].s;
2620 a = (Stab_Sym *)(s->data + sm_table[stab_index].offset);
2621 b = (Stab_Sym *)(s->data + s->data_offset);
2622 o = sm_table[stabstr_index].offset;
2623 while (a < b)
2624 a->n_strx += o, a++;
2625 }
2626
2627 /* second short pass to update sh_link and sh_info fields of new
2628 sections */
2629 for(i = 1; i < ehdr.e_shnum; i++) {
2630 s = sm_table[i].s;
2631 if (!s || !sm_table[i].new_section)
2632 continue;
2633 sh = &shdr[i];
2634 if (sh->sh_link > 0)
2635 s->link = sm_table[sh->sh_link].s;
2636 if (sh->sh_type == SHT_RELX) {
2637 s->sh_info = sm_table[sh->sh_info].s->sh_num;
2638 /* update backward link */
2639 s1->sections[s->sh_info]->reloc = s;
2640 }
2641 }
2642 sm = sm_table;
2643
2644 /* resolve symbols */
2645 old_to_new_syms = tcc_mallocz(nb_syms * sizeof(int));
2646
2647 sym = symtab + 1;
2648 for(i = 1; i < nb_syms; i++, sym++) {
2649 if (sym->st_shndx != SHN_UNDEF &&
2650 sym->st_shndx < SHN_LORESERVE) {
2651 sm = &sm_table[sym->st_shndx];
2652 if (sm->link_once) {
2653 /* if a symbol is in a link once section, we use the
2654 already defined symbol. It is very important to get
2655 correct relocations */
2656 if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
2657 name = (char *) strtab + sym->st_name;
2658 sym_index = find_elf_sym(symtab_section, name);
2659 if (sym_index)
2660 old_to_new_syms[i] = sym_index;
2661 }
2662 continue;
2663 }
2664 /* if no corresponding section added, no need to add symbol */
2665 if (!sm->s)
2666 continue;
2667 /* convert section number */
2668 sym->st_shndx = sm->s->sh_num;
2669 /* offset value */
2670 sym->st_value += sm->offset;
2671 }
2672 /* add symbol */
2673 name = (char *) strtab + sym->st_name;
2674 sym_index = add_elf_sym(symtab_section, sym->st_value, sym->st_size,
2675 sym->st_info, sym->st_other,
2676 sym->st_shndx, name);
2677 old_to_new_syms[i] = sym_index;
2678 }
2679
2680 /* third pass to patch relocation entries */
2681 for(i = 1; i < ehdr.e_shnum; i++) {
2682 s = sm_table[i].s;
2683 if (!s)
2684 continue;
2685 sh = &shdr[i];
2686 offset = sm_table[i].offset;
2687 switch(s->sh_type) {
2688 case SHT_RELX:
2689 /* take relocation offset information */
2690 offseti = sm_table[sh->sh_info].offset;
2691 for_each_elem(s, (offset / sizeof(*rel)), rel, ElfW_Rel) {
2692 int type;
2693 unsigned sym_index;
2694 /* convert symbol index */
2695 type = ELFW(R_TYPE)(rel->r_info);
2696 sym_index = ELFW(R_SYM)(rel->r_info);
2697 /* NOTE: only one symtab assumed */
2698 if (sym_index >= nb_syms)
2699 goto invalid_reloc;
2700 sym_index = old_to_new_syms[sym_index];
2701 /* ignore link_once in rel section. */
2702 if (!sym_index && !sm->link_once
2703 #ifdef TCC_TARGET_ARM
2704 && type != R_ARM_V4BX
2705 #endif
2706 ) {
2707 invalid_reloc:
2708 tcc_error_noabort("Invalid relocation entry [%2d] '%s' @ %.8x",
2709 i, strsec + sh->sh_name, rel->r_offset);
2710 goto fail;
2711 }
2712 rel->r_info = ELFW(R_INFO)(sym_index, type);
2713 /* offset the relocation offset */
2714 rel->r_offset += offseti;
2715 #ifdef TCC_TARGET_ARM
2716 /* Jumps and branches from a Thumb code to a PLT entry need
2717 special handling since PLT entries are ARM code.
2718 Unconditional bl instructions referencing PLT entries are
2719 handled by converting these instructions into blx
2720 instructions. Other case of instructions referencing a PLT
2721 entry require to add a Thumb stub before the PLT entry to
2722 switch to ARM mode. We set bit plt_thumb_stub of the
2723 attribute of a symbol to indicate such a case. */
2724 if (type == R_ARM_THM_JUMP24)
2725 alloc_sym_attr(s1, sym_index)->plt_thumb_stub = 1;
2726 #endif
2727 }
2728 break;
2729 default:
2730 break;
2731 }
2732 }
2733
2734 ret = 0;
2735 the_end:
2736 tcc_free(symtab);
2737 tcc_free(strtab);
2738 tcc_free(old_to_new_syms);
2739 tcc_free(sm_table);
2740 tcc_free(strsec);
2741 tcc_free(shdr);
2742 return ret;
2743 }
2744
2745 typedef struct ArchiveHeader {
2746 char ar_name[16]; /* name of this member */
2747 char ar_date[12]; /* file mtime */
2748 char ar_uid[6]; /* owner uid; printed as decimal */
2749 char ar_gid[6]; /* owner gid; printed as decimal */
2750 char ar_mode[8]; /* file mode, printed as octal */
2751 char ar_size[10]; /* file size, printed as decimal */
2752 char ar_fmag[2]; /* should contain ARFMAG */
2753 } ArchiveHeader;
2754
2755 static int get_be32(const uint8_t *b)
2756 {
2757 return b[3] | (b[2] << 8) | (b[1] << 16) | (b[0] << 24);
2758 }
2759
2760 /* load only the objects which resolve undefined symbols */
2761 static int tcc_load_alacarte(TCCState *s1, int fd, int size)
2762 {
2763 int i, bound, nsyms, sym_index, off, ret;
2764 uint8_t *data;
2765 const char *ar_names, *p;
2766 const uint8_t *ar_index;
2767 ElfW(Sym) *sym;
2768
2769 data = tcc_malloc(size);
2770 if (read(fd, data, size) != size)
2771 goto fail;
2772 nsyms = get_be32(data);
2773 ar_index = data + 4;
2774 ar_names = (char *) ar_index + nsyms * 4;
2775
2776 do {
2777 bound = 0;
2778 for(p = ar_names, i = 0; i < nsyms; i++, p += strlen(p)+1) {
2779 sym_index = find_elf_sym(symtab_section, p);
2780 if(sym_index) {
2781 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
2782 if(sym->st_shndx == SHN_UNDEF) {
2783 off = get_be32(ar_index + i * 4) + sizeof(ArchiveHeader);
2784 ++bound;
2785 lseek(fd, off, SEEK_SET);
2786 if(tcc_load_object_file(s1, fd, off) < 0) {
2787 fail:
2788 ret = -1;
2789 goto the_end;
2790 }
2791 }
2792 }
2793 }
2794 } while(bound);
2795 ret = 0;
2796 the_end:
2797 tcc_free(data);
2798 return ret;
2799 }
2800
2801 /* load a '.a' file */
2802 ST_FUNC int tcc_load_archive(TCCState *s1, int fd)
2803 {
2804 ArchiveHeader hdr;
2805 char ar_size[11];
2806 char ar_name[17];
2807 char magic[8];
2808 int size, len, i;
2809 unsigned long file_offset;
2810
2811 /* skip magic which was already checked */
2812 read(fd, magic, sizeof(magic));
2813
2814 for(;;) {
2815 len = read(fd, &hdr, sizeof(hdr));
2816 if (len == 0)
2817 break;
2818 if (len != sizeof(hdr)) {
2819 tcc_error_noabort("invalid archive");
2820 return -1;
2821 }
2822 memcpy(ar_size, hdr.ar_size, sizeof(hdr.ar_size));
2823 ar_size[sizeof(hdr.ar_size)] = '\0';
2824 size = strtol(ar_size, NULL, 0);
2825 memcpy(ar_name, hdr.ar_name, sizeof(hdr.ar_name));
2826 for(i = sizeof(hdr.ar_name) - 1; i >= 0; i--) {
2827 if (ar_name[i] != ' ')
2828 break;
2829 }
2830 ar_name[i + 1] = '\0';
2831 file_offset = lseek(fd, 0, SEEK_CUR);
2832 /* align to even */
2833 size = (size + 1) & ~1;
2834 if (!strcmp(ar_name, "/")) {
2835 /* coff symbol table : we handle it */
2836 if(s1->alacarte_link)
2837 return tcc_load_alacarte(s1, fd, size);
2838 } else if (!strcmp(ar_name, "//") ||
2839 !strcmp(ar_name, "__.SYMDEF") ||
2840 !strcmp(ar_name, "__.SYMDEF/") ||
2841 !strcmp(ar_name, "ARFILENAMES/")) {
2842 /* skip symbol table or archive names */
2843 } else {
2844 if (tcc_load_object_file(s1, fd, file_offset) < 0)
2845 return -1;
2846 }
2847 lseek(fd, file_offset + size, SEEK_SET);
2848 }
2849 return 0;
2850 }
2851
2852 #ifndef TCC_TARGET_PE
2853 /* load a DLL and all referenced DLLs. 'level = 0' means that the DLL
2854 is referenced by the user (so it should be added as DT_NEEDED in
2855 the generated ELF file) */
2856 ST_FUNC int tcc_load_dll(TCCState *s1, int fd, const char *filename, int level)
2857 {
2858 ElfW(Ehdr) ehdr;
2859 ElfW(Shdr) *shdr, *sh, *sh1;
2860 int i, j, nb_syms, nb_dts, sym_bind, ret;
2861 ElfW(Sym) *sym, *dynsym;
2862 ElfW(Dyn) *dt, *dynamic;
2863 unsigned char *dynstr;
2864 const char *name, *soname;
2865 DLLReference *dllref;
2866
2867 read(fd, &ehdr, sizeof(ehdr));
2868
2869 /* test CPU specific stuff */
2870 if (ehdr.e_ident[5] != ELFDATA2LSB ||
2871 ehdr.e_machine != EM_TCC_TARGET) {
2872 tcc_error_noabort("bad architecture");
2873 return -1;
2874 }
2875
2876 /* read sections */
2877 shdr = load_data(fd, ehdr.e_shoff, sizeof(ElfW(Shdr)) * ehdr.e_shnum);
2878
2879 /* load dynamic section and dynamic symbols */
2880 nb_syms = 0;
2881 nb_dts = 0;
2882 dynamic = NULL;
2883 dynsym = NULL; /* avoid warning */
2884 dynstr = NULL; /* avoid warning */
2885 for(i = 0, sh = shdr; i < ehdr.e_shnum; i++, sh++) {
2886 switch(sh->sh_type) {
2887 case SHT_DYNAMIC:
2888 nb_dts = sh->sh_size / sizeof(ElfW(Dyn));
2889 dynamic = load_data(fd, sh->sh_offset, sh->sh_size);
2890 break;
2891 case SHT_DYNSYM:
2892 nb_syms = sh->sh_size / sizeof(ElfW(Sym));
2893 dynsym = load_data(fd, sh->sh_offset, sh->sh_size);
2894 sh1 = &shdr[sh->sh_link];
2895 dynstr = load_data(fd, sh1->sh_offset, sh1->sh_size);
2896 break;
2897 default:
2898 break;
2899 }
2900 }
2901
2902 /* compute the real library name */
2903 soname = tcc_basename(filename);
2904
2905 for(i = 0, dt = dynamic; i < nb_dts; i++, dt++) {
2906 if (dt->d_tag == DT_SONAME) {
2907 soname = (char *) dynstr + dt->d_un.d_val;
2908 }
2909 }
2910
2911 /* if the dll is already loaded, do not load it */
2912 for(i = 0; i < s1->nb_loaded_dlls; i++) {
2913 dllref = s1->loaded_dlls[i];
2914 if (!strcmp(soname, dllref->name)) {
2915 /* but update level if needed */
2916 if (level < dllref->level)
2917 dllref->level = level;
2918 ret = 0;
2919 goto the_end;
2920 }
2921 }
2922
2923 /* add the dll and its level */
2924 dllref = tcc_mallocz(sizeof(DLLReference) + strlen(soname));
2925 dllref->level = level;
2926 strcpy(dllref->name, soname);
2927 dynarray_add((void ***)&s1->loaded_dlls, &s1->nb_loaded_dlls, dllref);
2928
2929 /* add dynamic symbols in dynsym_section */
2930 for(i = 1, sym = dynsym + 1; i < nb_syms; i++, sym++) {
2931 sym_bind = ELFW(ST_BIND)(sym->st_info);
2932 if (sym_bind == STB_LOCAL)
2933 continue;
2934 name = (char *) dynstr + sym->st_name;
2935 add_elf_sym(s1->dynsymtab_section, sym->st_value, sym->st_size,
2936 sym->st_info, sym->st_other, sym->st_shndx, name);
2937 }
2938
2939 /* load all referenced DLLs */
2940 for(i = 0, dt = dynamic; i < nb_dts; i++, dt++) {
2941 switch(dt->d_tag) {
2942 case DT_NEEDED:
2943 name = (char *) dynstr + dt->d_un.d_val;
2944 for(j = 0; j < s1->nb_loaded_dlls; j++) {
2945 dllref = s1->loaded_dlls[j];
2946 if (!strcmp(name, dllref->name))
2947 goto already_loaded;
2948 }
2949 if (tcc_add_dll(s1, name, AFF_REFERENCED_DLL) < 0) {
2950 tcc_error_noabort("referenced dll '%s' not found", name);
2951 ret = -1;
2952 goto the_end;
2953 }
2954 already_loaded:
2955 break;
2956 }
2957 }
2958 ret = 0;
2959 the_end:
2960 tcc_free(dynstr);
2961 tcc_free(dynsym);
2962 tcc_free(dynamic);
2963 tcc_free(shdr);
2964 return ret;
2965 }
2966
2967 #define LD_TOK_NAME 256
2968 #define LD_TOK_EOF (-1)
2969
2970 /* return next ld script token */
2971 static int ld_next(TCCState *s1, char *name, int name_size)
2972 {
2973 int c;
2974 char *q;
2975
2976 redo:
2977 switch(ch) {
2978 case ' ':
2979 case '\t':
2980 case '\f':
2981 case '\v':
2982 case '\r':
2983 case '\n':
2984 inp();
2985 goto redo;
2986 case '/':
2987 minp();
2988 if (ch == '*') {
2989 file->buf_ptr = parse_comment(file->buf_ptr);
2990 ch = file->buf_ptr[0];
2991 goto redo;
2992 } else {
2993 q = name;
2994 *q++ = '/';
2995 goto parse_name;
2996 }
2997 break;
2998 /* case 'a' ... 'z': */
2999 case 'a':
3000 case 'b':
3001 case 'c':
3002 case 'd':
3003 case 'e':
3004 case 'f':
3005 case 'g':
3006 case 'h':
3007 case 'i':
3008 case 'j':
3009 case 'k':
3010 case 'l':
3011 case 'm':
3012 case 'n':
3013 case 'o':
3014 case 'p':
3015 case 'q':
3016 case 'r':
3017 case 's':
3018 case 't':
3019 case 'u':
3020 case 'v':
3021 case 'w':
3022 case 'x':
3023 case 'y':
3024 case 'z':
3025 /* case 'A' ... 'z': */
3026 case 'A':
3027 case 'B':
3028 case 'C':
3029 case 'D':
3030 case 'E':
3031 case 'F':
3032 case 'G':
3033 case 'H':
3034 case 'I':
3035 case 'J':
3036 case 'K':
3037 case 'L':
3038 case 'M':
3039 case 'N':
3040 case 'O':
3041 case 'P':
3042 case 'Q':
3043 case 'R':
3044 case 'S':
3045 case 'T':
3046 case 'U':
3047 case 'V':
3048 case 'W':
3049 case 'X':
3050 case 'Y':
3051 case 'Z':
3052 case '_':
3053 case '\\':
3054 case '.':
3055 case '$':
3056 case '~':
3057 q = name;
3058 parse_name:
3059 for(;;) {
3060 if (!((ch >= 'a' && ch <= 'z') ||
3061 (ch >= 'A' && ch <= 'Z') ||
3062 (ch >= '0' && ch <= '9') ||
3063 strchr("/.-_+=$:\\,~", ch)))
3064 break;
3065 if ((q - name) < name_size - 1) {
3066 *q++ = ch;
3067 }
3068 minp();
3069 }
3070 *q = '\0';
3071 c = LD_TOK_NAME;
3072 break;
3073 case CH_EOF:
3074 c = LD_TOK_EOF;
3075 break;
3076 default:
3077 c = ch;
3078 inp();
3079 break;
3080 }
3081 return c;
3082 }
3083
3084 static int ld_add_file(TCCState *s1, const char filename[])
3085 {
3086 int ret;
3087
3088 ret = tcc_add_file_internal(s1, filename, 0);
3089 if (ret)
3090 ret = tcc_add_dll(s1, filename, 0);
3091 return ret;
3092 }
3093
3094 static inline int new_undef_syms(void)
3095 {
3096 int ret = 0;
3097 ret = new_undef_sym;
3098 new_undef_sym = 0;
3099 return ret;
3100 }
3101
3102 static int ld_add_file_list(TCCState *s1, const char *cmd, int as_needed)
3103 {
3104 char filename[1024], libname[1024];
3105 int t, group, nblibs = 0, ret = 0;
3106 char **libs = NULL;
3107
3108 group = !strcmp(cmd, "GROUP");
3109 if (!as_needed)
3110 new_undef_syms();
3111 t = ld_next(s1, filename, sizeof(filename));
3112 if (t != '(')
3113 expect("(");
3114 t = ld_next(s1, filename, sizeof(filename));
3115 for(;;) {
3116 libname[0] = '\0';
3117 if (t == LD_TOK_EOF) {
3118 tcc_error_noabort("unexpected end of file");
3119 ret = -1;
3120 goto lib_parse_error;
3121 } else if (t == ')') {
3122 break;
3123 } else if (t == '-') {
3124 t = ld_next(s1, filename, sizeof(filename));
3125 if ((t != LD_TOK_NAME) || (filename[0] != 'l')) {
3126 tcc_error_noabort("library name expected");
3127 ret = -1;
3128 goto lib_parse_error;
3129 }
3130 pstrcpy(libname, sizeof libname, &filename[1]);
3131 if (s1->static_link) {
3132 snprintf(filename, sizeof filename, "lib%s.a", libname);
3133 } else {
3134 snprintf(filename, sizeof filename, "lib%s.so", libname);
3135 }
3136 } else if (t != LD_TOK_NAME) {
3137 tcc_error_noabort("filename expected");
3138 ret = -1;
3139 goto lib_parse_error;
3140 }
3141 if (!strcmp(filename, "AS_NEEDED")) {
3142 ret = ld_add_file_list(s1, cmd, 1);
3143 if (ret)
3144 goto lib_parse_error;
3145 } else {
3146 /* TODO: Implement AS_NEEDED support. Ignore it for now */
3147 if (!as_needed) {
3148 ret = ld_add_file(s1, filename);
3149 if (ret)
3150 goto lib_parse_error;
3151 if (group) {
3152 /* Add the filename *and* the libname to avoid future conversions */
3153 dynarray_add((void ***) &libs, &nblibs, tcc_strdup(filename));
3154 if (libname[0] != '\0')
3155 dynarray_add((void ***) &libs, &nblibs, tcc_strdup(libname));
3156 }
3157 }
3158 }
3159 t = ld_next(s1, filename, sizeof(filename));
3160 if (t == ',') {
3161 t = ld_next(s1, filename, sizeof(filename));
3162 }
3163 }
3164 if (group && !as_needed) {
3165 while (new_undef_syms()) {
3166 int i;
3167
3168 for (i = 0; i < nblibs; i ++)
3169 ld_add_file(s1, libs[i]);
3170 }
3171 }
3172 lib_parse_error:
3173 dynarray_reset(&libs, &nblibs);
3174 return ret;
3175 }
3176
3177 /* interpret a subset of GNU ldscripts to handle the dummy libc.so
3178 files */
3179 ST_FUNC int tcc_load_ldscript(TCCState *s1)
3180 {
3181 char cmd[64];
3182 char filename[1024];
3183 int t, ret;
3184
3185 ch = file->buf_ptr[0];
3186 ch = handle_eob();
3187 for(;;) {
3188 t = ld_next(s1, cmd, sizeof(cmd));
3189 if (t == LD_TOK_EOF)
3190 return 0;
3191 else if (t != LD_TOK_NAME)
3192 return -1;
3193 if (!strcmp(cmd, "INPUT") ||
3194 !strcmp(cmd, "GROUP")) {
3195 ret = ld_add_file_list(s1, cmd, 0);
3196 if (ret)
3197 return ret;
3198 } else if (!strcmp(cmd, "OUTPUT_FORMAT") ||
3199 !strcmp(cmd, "TARGET")) {
3200 /* ignore some commands */
3201 t = ld_next(s1, cmd, sizeof(cmd));
3202 if (t != '(')
3203 expect("(");
3204 for(;;) {
3205 t = ld_next(s1, filename, sizeof(filename));
3206 if (t == LD_TOK_EOF) {
3207 tcc_error_noabort("unexpected end of file");
3208 return -1;
3209 } else if (t == ')') {
3210 break;
3211 }
3212 }
3213 } else {
3214 return -1;
3215 }
3216 }
3217 return 0;
3218 }
3219 #endif /* !TCC_TARGET_PE */
Tiny C Compiler main repository