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fix for the previous commit: tcc_add_support() was used before definition
[tinycc.git] / tccelf.c
blob502479fd8cc01a95e752fb1136427958c4bdd149
1 /*
2 * ELF file handling for TCC
3 *
4 * Copyright (c) 2001-2004 Fabrice Bellard
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 */
20
21 #include "tcc.h"
22
23 /* Define this to get some debug output during relocation processing. */
24 #undef DEBUG_RELOC
25
26 /* XXX: avoid static variable */
27 static int new_undef_sym = 0; /* Is there a new undefined sym since last new_undef_sym() */
28
29 ST_FUNC int put_elf_str(Section *s, const char *sym)
30 {
31 int offset, len;
32 char *ptr;
33
34 len = strlen(sym) + 1;
35 offset = s->data_offset;
36 ptr = section_ptr_add(s, len);
37 memcpy(ptr, sym, len);
38 return offset;
39 }
40
41 /* elf symbol hashing function */
42 static unsigned long elf_hash(const unsigned char *name)
43 {
44 unsigned long h = 0, g;
45
46 while (*name) {
47 h = (h << 4) + *name++;
48 g = h & 0xf0000000;
49 if (g)
50 h ^= g >> 24;
51 h &= ~g;
52 }
53 return h;
54 }
55
56 /* rebuild hash table of section s */
57 /* NOTE: we do factorize the hash table code to go faster */
58 static void rebuild_hash(Section *s, unsigned int nb_buckets)
59 {
60 ElfW(Sym) *sym;
61 int *ptr, *hash, nb_syms, sym_index, h;
62 unsigned char *strtab;
63
64 strtab = s->link->data;
65 nb_syms = s->data_offset / sizeof(ElfW(Sym));
66
67 s->hash->data_offset = 0;
68 ptr = section_ptr_add(s->hash, (2 + nb_buckets + nb_syms) * sizeof(int));
69 ptr[0] = nb_buckets;
70 ptr[1] = nb_syms;
71 ptr += 2;
72 hash = ptr;
73 memset(hash, 0, (nb_buckets + 1) * sizeof(int));
74 ptr += nb_buckets + 1;
75
76 sym = (ElfW(Sym) *)s->data + 1;
77 for(sym_index = 1; sym_index < nb_syms; sym_index++) {
78 if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
79 h = elf_hash(strtab + sym->st_name) % nb_buckets;
80 *ptr = hash[h];
81 hash[h] = sym_index;
82 } else {
83 *ptr = 0;
84 }
85 ptr++;
86 sym++;
87 }
88 }
89
90 /* return the symbol number */
91 ST_FUNC int put_elf_sym(Section *s, addr_t value, unsigned long size,
92 int info, int other, int shndx, const char *name)
93 {
94 int name_offset, sym_index;
95 int nbuckets, h;
96 ElfW(Sym) *sym;
97 Section *hs;
98
99 sym = section_ptr_add(s, sizeof(ElfW(Sym)));
100 if (name)
101 name_offset = put_elf_str(s->link, name);
102 else
103 name_offset = 0;
104 /* XXX: endianness */
105 sym->st_name = name_offset;
106 sym->st_value = value;
107 sym->st_size = size;
108 sym->st_info = info;
109 sym->st_other = other;
110 sym->st_shndx = shndx;
111 sym_index = sym - (ElfW(Sym) *)s->data;
112 hs = s->hash;
113 if (hs) {
114 int *ptr, *base;
115 ptr = section_ptr_add(hs, sizeof(int));
116 base = (int *)hs->data;
117 /* only add global or weak symbols */
118 if (ELFW(ST_BIND)(info) != STB_LOCAL) {
119 /* add another hashing entry */
120 nbuckets = base[0];
121 h = elf_hash((unsigned char *) name) % nbuckets;
122 *ptr = base[2 + h];
123 base[2 + h] = sym_index;
124 base[1]++;
125 /* we resize the hash table */
126 hs->nb_hashed_syms++;
127 if (hs->nb_hashed_syms > 2 * nbuckets) {
128 rebuild_hash(s, 2 * nbuckets);
129 }
130 } else {
131 *ptr = 0;
132 base[1]++;
133 }
134 }
135 return sym_index;
136 }
137
138 /* find global ELF symbol 'name' and return its index. Return 0 if not
139 found. */
140 ST_FUNC int find_elf_sym(Section *s, const char *name)
141 {
142 ElfW(Sym) *sym;
143 Section *hs;
144 int nbuckets, sym_index, h;
145 const char *name1;
146
147 hs = s->hash;
148 if (!hs)
149 return 0;
150 nbuckets = ((int *)hs->data)[0];
151 h = elf_hash((unsigned char *) name) % nbuckets;
152 sym_index = ((int *)hs->data)[2 + h];
153 while (sym_index != 0) {
154 sym = &((ElfW(Sym) *)s->data)[sym_index];
155 name1 = (char *) s->link->data + sym->st_name;
156 if (!strcmp(name, name1))
157 return sym_index;
158 sym_index = ((int *)hs->data)[2 + nbuckets + sym_index];
159 }
160 return 0;
161 }
162
163 /* return elf symbol value, signal error if 'err' is nonzero */
164 ST_FUNC addr_t get_elf_sym_addr(TCCState *s, const char *name, int err)
165 {
166 int sym_index;
167 ElfW(Sym) *sym;
168
169 sym_index = find_elf_sym(s->symtab, name);
170 sym = &((ElfW(Sym) *)s->symtab->data)[sym_index];
171 if (!sym_index || sym->st_shndx == SHN_UNDEF) {
172 if (err)
173 tcc_error("%s not defined", name);
174 return 0;
175 }
176 return sym->st_value;
177 }
178
179 /* return elf symbol value */
180 LIBTCCAPI void *tcc_get_symbol(TCCState *s, const char *name)
181 {
182 return (void*)(uintptr_t)get_elf_sym_addr(s, name, 0);
183 }
184
185 #if defined TCC_IS_NATIVE || defined TCC_TARGET_PE
186 /* return elf symbol value or error */
187 ST_FUNC void* tcc_get_symbol_err(TCCState *s, const char *name)
188 {
189 return (void*)(uintptr_t)get_elf_sym_addr(s, name, 1);
190 }
191 #endif
192
193 /* add an elf symbol : check if it is already defined and patch
194 it. Return symbol index. NOTE that sh_num can be SHN_UNDEF. */
195 ST_FUNC int add_elf_sym(Section *s, addr_t value, unsigned long size,
196 int info, int other, int sh_num, const char *name)
197 {
198 ElfW(Sym) *esym;
199 int sym_bind, sym_index, sym_type, esym_bind;
200 unsigned char sym_vis, esym_vis, new_vis;
201
202 sym_bind = ELFW(ST_BIND)(info);
203 sym_type = ELFW(ST_TYPE)(info);
204 sym_vis = ELFW(ST_VISIBILITY)(other);
205
206 if (sym_bind != STB_LOCAL) {
207 /* we search global or weak symbols */
208 sym_index = find_elf_sym(s, name);
209 if (!sym_index)
210 goto do_def;
211 esym = &((ElfW(Sym) *)s->data)[sym_index];
212 if (esym->st_shndx != SHN_UNDEF) {
213 esym_bind = ELFW(ST_BIND)(esym->st_info);
214 /* propagate the most constraining visibility */
215 /* STV_DEFAULT(0)<STV_PROTECTED(3)<STV_HIDDEN(2)<STV_INTERNAL(1) */
216 esym_vis = ELFW(ST_VISIBILITY)(esym->st_other);
217 if (esym_vis == STV_DEFAULT) {
218 new_vis = sym_vis;
219 } else if (sym_vis == STV_DEFAULT) {
220 new_vis = esym_vis;
221 } else {
222 new_vis = (esym_vis < sym_vis) ? esym_vis : sym_vis;
223 }
224 esym->st_other = (esym->st_other & ~ELFW(ST_VISIBILITY)(-1))
225 | new_vis;
226 other = esym->st_other; /* in case we have to patch esym */
227 if (sh_num == SHN_UNDEF) {
228 /* ignore adding of undefined symbol if the
229 corresponding symbol is already defined */
230 } else if (sym_bind == STB_GLOBAL && esym_bind == STB_WEAK) {
231 /* global overrides weak, so patch */
232 goto do_patch;
233 } else if (sym_bind == STB_WEAK && esym_bind == STB_GLOBAL) {
234 /* weak is ignored if already global */
235 } else if (sym_bind == STB_WEAK && esym_bind == STB_WEAK) {
236 /* keep first-found weak definition, ignore subsequents */
237 } else if (sym_vis == STV_HIDDEN || sym_vis == STV_INTERNAL) {
238 /* ignore hidden symbols after */
239 } else if (esym->st_shndx == SHN_COMMON
240 && (sh_num < SHN_LORESERVE || sh_num == SHN_COMMON)) {
241 /* gr: Happens with 'tcc ... -static tcctest.c' on e.g. Ubuntu 6.01
242 No idea if this is the correct solution ... */
243 goto do_patch;
244 } else if (s == tcc_state->dynsymtab_section) {
245 /* we accept that two DLL define the same symbol */
246 } else {
247 #if 0
248 printf("new_bind=%x new_shndx=%x new_vis=%x old_bind=%x old_shndx=%x old_vis=%x\n",
249 sym_bind, sh_num, new_vis, esym_bind, esym->st_shndx, esym_vis);
250 #endif
251 tcc_error_noabort("'%s' defined twice", name);
252 }
253 } else {
254 do_patch:
255 esym->st_info = ELFW(ST_INFO)(sym_bind, sym_type);
256 esym->st_shndx = sh_num;
257 new_undef_sym = 1;
258 esym->st_value = value;
259 esym->st_size = size;
260 esym->st_other = other;
261 }
262 } else {
263 do_def:
264 sym_index = put_elf_sym(s, value, size,
265 ELFW(ST_INFO)(sym_bind, sym_type), other,
266 sh_num, name);
267 }
268 return sym_index;
269 }
270
271 /* put relocation */
272 ST_FUNC void put_elf_reloca(Section *symtab, Section *s, unsigned long offset,
273 int type, int symbol, addr_t addend)
274 {
275 char buf[256];
276 Section *sr;
277 ElfW_Rel *rel;
278
279 sr = s->reloc;
280 if (!sr) {
281 /* if no relocation section, create it */
282 snprintf(buf, sizeof(buf), REL_SECTION_FMT, s->name);
283 /* if the symtab is allocated, then we consider the relocation
284 are also */
285 sr = new_section(tcc_state, buf, SHT_RELX, symtab->sh_flags);
286 sr->sh_entsize = sizeof(ElfW_Rel);
287 sr->link = symtab;
288 sr->sh_info = s->sh_num;
289 s->reloc = sr;
290 }
291 rel = section_ptr_add(sr, sizeof(ElfW_Rel));
292 rel->r_offset = offset;
293 rel->r_info = ELFW(R_INFO)(symbol, type);
294 #if defined(TCC_TARGET_ARM64) || defined(TCC_TARGET_X86_64)
295 rel->r_addend = addend;
296 #else
297 if (addend)
298 tcc_error("non-zero addend on REL architecture");
299 #endif
300 }
301
302 ST_FUNC void put_elf_reloc(Section *symtab, Section *s, unsigned long offset,
303 int type, int symbol)
304 {
305 put_elf_reloca(symtab, s, offset, type, symbol, 0);
306 }
307
308 /* put stab debug information */
309
310 ST_FUNC void put_stabs(const char *str, int type, int other, int desc,
311 unsigned long value)
312 {
313 Stab_Sym *sym;
314
315 sym = section_ptr_add(stab_section, sizeof(Stab_Sym));
316 if (str) {
317 sym->n_strx = put_elf_str(stabstr_section, str);
318 } else {
319 sym->n_strx = 0;
320 }
321 sym->n_type = type;
322 sym->n_other = other;
323 sym->n_desc = desc;
324 sym->n_value = value;
325 }
326
327 ST_FUNC void put_stabs_r(const char *str, int type, int other, int desc,
328 unsigned long value, Section *sec, int sym_index)
329 {
330 put_stabs(str, type, other, desc, value);
331 put_elf_reloc(symtab_section, stab_section,
332 stab_section->data_offset - sizeof(unsigned int),
333 R_DATA_32, sym_index);
334 }
335
336 ST_FUNC void put_stabn(int type, int other, int desc, int value)
337 {
338 put_stabs(NULL, type, other, desc, value);
339 }
340
341 ST_FUNC void put_stabd(int type, int other, int desc)
342 {
343 put_stabs(NULL, type, other, desc, 0);
344 }
345
346 /* Browse each elem of type <type> in section <sec> starting at elem <startoff>
347 using variable <elem> */
348 #define for_each_elem(sec, startoff, elem, type) \
349 for (elem = (type *) sec->data + startoff; \
350 elem < (type *) (sec->data + sec->data_offset); elem++)
351
352 /* In an ELF file symbol table, the local symbols must appear below
353 the global and weak ones. Since TCC cannot sort it while generating
354 the code, we must do it after. All the relocation tables are also
355 modified to take into account the symbol table sorting */
356 static void sort_syms(TCCState *s1, Section *s)
357 {
358 int *old_to_new_syms;
359 ElfW(Sym) *new_syms;
360 int nb_syms, i;
361 ElfW(Sym) *p, *q;
362 ElfW_Rel *rel;
363 Section *sr;
364 int type, sym_index;
365
366 nb_syms = s->data_offset / sizeof(ElfW(Sym));
367 new_syms = tcc_malloc(nb_syms * sizeof(ElfW(Sym)));
368 old_to_new_syms = tcc_malloc(nb_syms * sizeof(int));
369
370 /* first pass for local symbols */
371 p = (ElfW(Sym) *)s->data;
372 q = new_syms;
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 /* save the number of local symbols in section header */
381 s->sh_info = q - new_syms;
382
383 /* then second pass for non local symbols */
384 p = (ElfW(Sym) *)s->data;
385 for(i = 0; i < nb_syms; i++) {
386 if (ELFW(ST_BIND)(p->st_info) != STB_LOCAL) {
387 old_to_new_syms[i] = q - new_syms;
388 *q++ = *p;
389 }
390 p++;
391 }
392
393 /* we copy the new symbols to the old */
394 memcpy(s->data, new_syms, nb_syms * sizeof(ElfW(Sym)));
395 tcc_free(new_syms);
396
397 /* now we modify all the relocations */
398 for(i = 1; i < s1->nb_sections; i++) {
399 sr = s1->sections[i];
400 if (sr->sh_type == SHT_RELX && sr->link == s) {
401 for_each_elem(sr, 0, rel, ElfW_Rel) {
402 sym_index = ELFW(R_SYM)(rel->r_info);
403 type = ELFW(R_TYPE)(rel->r_info);
404 sym_index = old_to_new_syms[sym_index];
405 rel->r_info = ELFW(R_INFO)(sym_index, type);
406 }
407 }
408 }
409
410 tcc_free(old_to_new_syms);
411 }
412
413 /* relocate common symbols in the .bss section */
414 ST_FUNC void relocate_common_syms(void)
415 {
416 ElfW(Sym) *sym;
417 unsigned long offset, align;
418
419 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
420 if (sym->st_shndx == SHN_COMMON) {
421 /* align symbol */
422 align = sym->st_value;
423 offset = bss_section->data_offset;
424 offset = (offset + align - 1) & -align;
425 sym->st_value = offset;
426 sym->st_shndx = bss_section->sh_num;
427 offset += sym->st_size;
428 bss_section->data_offset = offset;
429 }
430 }
431 }
432
433 /* relocate symbol table, resolve undefined symbols if do_resolve is
434 true and output error if undefined symbol. */
435 ST_FUNC void relocate_syms(TCCState *s1, int do_resolve)
436 {
437 ElfW(Sym) *sym, *esym;
438 int sym_bind, sh_num, sym_index;
439 const char *name;
440
441 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
442 sh_num = sym->st_shndx;
443 if (sh_num == SHN_UNDEF) {
444 name = (char *) strtab_section->data + sym->st_name;
445 /* Use ld.so to resolve symbol for us (for tcc -run) */
446 if (do_resolve) {
447 #if defined TCC_IS_NATIVE && !defined _WIN32
448 void *addr;
449 name = (char *) symtab_section->link->data + sym->st_name;
450 addr = resolve_sym(s1, name);
451 if (addr) {
452 sym->st_value = (addr_t)addr;
453 #ifdef DEBUG_RELOC
454 printf ("relocate_sym: %s -> 0x%lx\n", name, sym->st_value);
455 #endif
456 goto found;
457 }
458 #endif
459 } else if (s1->dynsym) {
460 /* if dynamic symbol exist, then use it */
461 sym_index = find_elf_sym(s1->dynsym, name);
462 if (sym_index) {
463 esym = &((ElfW(Sym) *)s1->dynsym->data)[sym_index];
464 sym->st_value = esym->st_value;
465 goto found;
466 }
467 }
468 /* XXX: _fp_hw seems to be part of the ABI, so we ignore
469 it */
470 if (!strcmp(name, "_fp_hw"))
471 goto found;
472 /* only weak symbols are accepted to be undefined. Their
473 value is zero */
474 sym_bind = ELFW(ST_BIND)(sym->st_info);
475 if (sym_bind == STB_WEAK) {
476 sym->st_value = 0;
477 } else {
478 tcc_error_noabort("undefined symbol '%s'", name);
479 }
480 } else if (sh_num < SHN_LORESERVE) {
481 /* add section base */
482 sym->st_value += s1->sections[sym->st_shndx]->sh_addr;
483 }
484 found: ;
485 }
486 }
487
488 /* relocate a given section (CPU dependent) by applying the relocations
489 in the associated relocation section */
490 ST_FUNC void relocate_section(TCCState *s1, Section *s)
491 {
492 Section *sr = s->reloc;
493 ElfW_Rel *rel;
494 ElfW(Sym) *sym;
495 int type, sym_index;
496 unsigned char *ptr;
497 addr_t val, addr;
498 #if defined TCC_TARGET_I386 || defined TCC_TARGET_X86_64
499 ElfW_Rel *qrel = (ElfW_Rel *) sr->data; /* ptr to next reloc entry reused */
500 int esym_index;
501 #endif
502
503 for_each_elem(sr, 0, rel, ElfW_Rel) {
504 ptr = s->data + rel->r_offset;
505
506 sym_index = ELFW(R_SYM)(rel->r_info);
507 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
508 val = sym->st_value;
509 #if defined(TCC_TARGET_ARM64) || defined(TCC_TARGET_X86_64)
510 val += rel->r_addend;
511 #endif
512 type = ELFW(R_TYPE)(rel->r_info);
513 addr = s->sh_addr + rel->r_offset;
514
515 /* CPU specific */
516 switch(type) {
517 #if defined(TCC_TARGET_I386)
518 case R_386_32:
519 if (s1->output_type == TCC_OUTPUT_DLL) {
520 esym_index = s1->symtab_to_dynsym[sym_index];
521 qrel->r_offset = rel->r_offset;
522 if (esym_index) {
523 qrel->r_info = ELFW(R_INFO)(esym_index, R_386_32);
524 qrel++;
525 break;
526 } else {
527 qrel->r_info = ELFW(R_INFO)(0, R_386_RELATIVE);
528 qrel++;
529 }
530 }
531 *(int *)ptr += val;
532 break;
533 case R_386_PC32:
534 if (s1->output_type == TCC_OUTPUT_DLL) {
535 /* DLL relocation */
536 esym_index = s1->symtab_to_dynsym[sym_index];
537 if (esym_index) {
538 qrel->r_offset = rel->r_offset;
539 qrel->r_info = ELFW(R_INFO)(esym_index, R_386_PC32);
540 qrel++;
541 break;
542 }
543 }
544 *(int *)ptr += val - addr;
545 break;
546 case R_386_PLT32:
547 *(int *)ptr += val - addr;
548 break;
549 case R_386_GLOB_DAT:
550 case R_386_JMP_SLOT:
551 *(int *)ptr = val;
552 break;
553 case R_386_GOTPC:
554 *(int *)ptr += s1->got->sh_addr - addr;
555 break;
556 case R_386_GOTOFF:
557 *(int *)ptr += val - s1->got->sh_addr;
558 break;
559 case R_386_GOT32:
560 /* we load the got offset */
561 *(int *)ptr += s1->sym_attrs[sym_index].got_offset;
562 break;
563 case R_386_16:
564 if (s1->output_format != TCC_OUTPUT_FORMAT_BINARY) {
565 output_file:
566 tcc_error("can only produce 16-bit binary files");
567 }
568 *(short *)ptr += val;
569 break;
570 case R_386_PC16:
571 if (s1->output_format != TCC_OUTPUT_FORMAT_BINARY)
572 goto output_file;
573 *(short *)ptr += val - addr;
574 break;
575 #elif defined(TCC_TARGET_ARM)
576 case R_ARM_PC24:
577 case R_ARM_CALL:
578 case R_ARM_JUMP24:
579 case R_ARM_PLT32:
580 {
581 int x, is_thumb, is_call, h, blx_avail, is_bl, th_ko;
582 x = (*(int *) ptr) & 0xffffff;
583 if (sym->st_shndx == SHN_UNDEF)
584 val = s1->plt->sh_addr;
585 #ifdef DEBUG_RELOC
586 printf ("reloc %d: x=0x%x val=0x%x ", type, x, val);
587 #endif
588 (*(int *)ptr) &= 0xff000000;
589 if (x & 0x800000)
590 x -= 0x1000000;
591 x <<= 2;
592 blx_avail = (TCC_ARM_VERSION >= 5);
593 is_thumb = val & 1;
594 is_bl = (*(unsigned *) ptr) >> 24 == 0xeb;
595 is_call = (type == R_ARM_CALL || (type == R_ARM_PC24 && is_bl));
596 x += val - addr;
597 #ifdef DEBUG_RELOC
598 printf (" newx=0x%x name=%s\n", x,
599 (char *) symtab_section->link->data + sym->st_name);
600 #endif
601 h = x & 2;
602 th_ko = (x & 3) && (!blx_avail || !is_call);
603 if (th_ko || x >= 0x2000000 || x < -0x2000000)
604 tcc_error("can't relocate value at %x,%d",addr, type);
605 x >>= 2;
606 x &= 0xffffff;
607 /* Only reached if blx is avail and it is a call */
608 if (is_thumb) {
609 x |= h << 24;
610 (*(int *)ptr) = 0xfa << 24; /* bl -> blx */
611 }
612 (*(int *) ptr) |= x;
613 }
614 break;
615 /* Since these relocations only concern Thumb-2 and blx instruction was
616 introduced before Thumb-2, we can assume blx is available and not
617 guard its use */
618 case R_ARM_THM_PC22:
619 case R_ARM_THM_JUMP24:
620 {
621 int x, hi, lo, s, j1, j2, i1, i2, imm10, imm11;
622 int to_thumb, is_call, to_plt, blx_bit = 1 << 12;
623 Section *plt;
624
625 /* weak reference */
626 if (sym->st_shndx == SHN_UNDEF &&
627 ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
628 break;
629
630 /* Get initial offset */
631 hi = (*(uint16_t *)ptr);
632 lo = (*(uint16_t *)(ptr+2));
633 s = (hi >> 10) & 1;
634 j1 = (lo >> 13) & 1;
635 j2 = (lo >> 11) & 1;
636 i1 = (j1 ^ s) ^ 1;
637 i2 = (j2 ^ s) ^ 1;
638 imm10 = hi & 0x3ff;
639 imm11 = lo & 0x7ff;
640 x = (s << 24) | (i1 << 23) | (i2 << 22) |
641 (imm10 << 12) | (imm11 << 1);
642 if (x & 0x01000000)
643 x -= 0x02000000;
644
645 /* Relocation infos */
646 to_thumb = val & 1;
647 plt = s1->plt;
648 to_plt = (val >= plt->sh_addr) &&
649 (val < plt->sh_addr + plt->data_offset);
650 is_call = (type == R_ARM_THM_PC22);
651
652 /* Compute final offset */
653 if (to_plt && !is_call) /* Point to 1st instr of Thumb stub */
654 x -= 4;
655 x += val - addr;
656 if (!to_thumb && is_call) {
657 blx_bit = 0; /* bl -> blx */
658 x = (x + 3) & -4; /* Compute offset from aligned PC */
659 }
660
661 /* Check that relocation is possible
662 * offset must not be out of range
663 * if target is to be entered in arm mode:
664 - bit 1 must not set
665 - instruction must be a call (bl) or a jump to PLT */
666 if (!to_thumb || x >= 0x1000000 || x < -0x1000000)
667 if (to_thumb || (val & 2) || (!is_call && !to_plt))
668 tcc_error("can't relocate value at %x,%d",addr, type);
669
670 /* Compute and store final offset */
671 s = (x >> 24) & 1;
672 i1 = (x >> 23) & 1;
673 i2 = (x >> 22) & 1;
674 j1 = s ^ (i1 ^ 1);
675 j2 = s ^ (i2 ^ 1);
676 imm10 = (x >> 12) & 0x3ff;
677 imm11 = (x >> 1) & 0x7ff;
678 (*(uint16_t *)ptr) = (uint16_t) ((hi & 0xf800) |
679 (s << 10) | imm10);
680 (*(uint16_t *)(ptr+2)) = (uint16_t) ((lo & 0xc000) |
681 (j1 << 13) | blx_bit | (j2 << 11) |
682 imm11);
683 }
684 break;
685 case R_ARM_MOVT_ABS:
686 case R_ARM_MOVW_ABS_NC:
687 {
688 int x, imm4, imm12;
689 if (type == R_ARM_MOVT_ABS)
690 val >>= 16;
691 imm12 = val & 0xfff;
692 imm4 = (val >> 12) & 0xf;
693 x = (imm4 << 16) | imm12;
694 if (type == R_ARM_THM_MOVT_ABS)
695 *(int *)ptr |= x;
696 else
697 *(int *)ptr += x;
698 }
699 break;
700 case R_ARM_THM_MOVT_ABS:
701 case R_ARM_THM_MOVW_ABS_NC:
702 {
703 int x, i, imm4, imm3, imm8;
704 if (type == R_ARM_THM_MOVT_ABS)
705 val >>= 16;
706 imm8 = val & 0xff;
707 imm3 = (val >> 8) & 0x7;
708 i = (val >> 11) & 1;
709 imm4 = (val >> 12) & 0xf;
710 x = (imm3 << 28) | (imm8 << 16) | (i << 10) | imm4;
711 if (type == R_ARM_THM_MOVT_ABS)
712 *(int *)ptr |= x;
713 else
714 *(int *)ptr += x;
715 }
716 break;
717 case R_ARM_PREL31:
718 {
719 int x;
720 x = (*(int *)ptr) & 0x7fffffff;
721 (*(int *)ptr) &= 0x80000000;
722 x = (x * 2) / 2;
723 x += val - addr;
724 if((x^(x>>1))&0x40000000)
725 tcc_error("can't relocate value at %x,%d",addr, type);
726 (*(int *)ptr) |= x & 0x7fffffff;
727 }
728 case R_ARM_ABS32:
729 *(int *)ptr += val;
730 break;
731 case R_ARM_REL32:
732 *(int *)ptr += val - addr;
733 break;
734 case R_ARM_GOTPC:
735 *(int *)ptr += s1->got->sh_addr - addr;
736 break;
737 case R_ARM_GOTOFF:
738 *(int *)ptr += val - s1->got->sh_addr;
739 break;
740 case R_ARM_GOT32:
741 /* we load the got offset */
742 *(int *)ptr += s1->sym_attrs[sym_index].got_offset;
743 break;
744 case R_ARM_COPY:
745 break;
746 case R_ARM_V4BX:
747 /* trade Thumb support for ARMv4 support */
748 if ((0x0ffffff0 & *(int*)ptr) == 0x012FFF10)
749 *(int*)ptr ^= 0xE12FFF10 ^ 0xE1A0F000; /* BX Rm -> MOV PC, Rm */
750 break;
751 case R_ARM_GLOB_DAT:
752 case R_ARM_JUMP_SLOT:
753 *(addr_t *)ptr = val;
754 break;
755 case R_ARM_NONE:
756 /* Nothing to do. Normally used to indicate a dependency
757 on a certain symbol (like for exception handling under EABI). */
758 break;
759 default:
760 fprintf(stderr,"FIXME: handle reloc type %x at %x [%p] to %x\n",
761 type, (unsigned)addr, ptr, (unsigned)val);
762 break;
763 #elif defined(TCC_TARGET_ARM64)
764 case R_AARCH64_ABS64:
765 *(uint64_t *)ptr = val;
766 break;
767 case R_AARCH64_ABS32:
768 *(uint32_t *)ptr = val;
769 break;
770 case R_AARCH64_MOVW_UABS_G0_NC:
771 *(uint32_t *)ptr = (*(uint32_t *)ptr & 0xffe0001f) |
772 (val & 0xffff) << 5;
773 break;
774 case R_AARCH64_MOVW_UABS_G1_NC:
775 *(uint32_t *)ptr = (*(uint32_t *)ptr & 0xffe0001f) |
776 (val >> 16 & 0xffff) << 5;
777 break;
778 case R_AARCH64_MOVW_UABS_G2_NC:
779 *(uint32_t *)ptr = (*(uint32_t *)ptr & 0xffe0001f) |
780 (val >> 32 & 0xffff) << 5;
781 break;
782 case R_AARCH64_MOVW_UABS_G3:
783 *(uint32_t *)ptr = (*(uint32_t *)ptr & 0xffe0001f) |
784 (val >> 48 & 0xffff) << 5;
785 break;
786 case R_AARCH64_ADR_PREL_PG_HI21: {
787 uint64_t off = (val >> 12) - (addr >> 12);
788 if ((off + ((uint64_t)1 << 20)) >> 21)
789 tcc_error("R_AARCH64_ADR_PREL_PG_HI21 relocation failed");
790 *(uint32_t *)ptr = (*(uint32_t *)ptr & 0x9f00001f) |
791 (off & 0x1ffffc) << 3 | (off & 3) << 29;
792 break;
793 }
794 case R_AARCH64_ADD_ABS_LO12_NC:
795 *(uint32_t *)ptr = (*(uint32_t *)ptr & 0xffc003ff) |
796 (val & 0xfff) << 10;
797 break;
798 case R_AARCH64_JUMP26:
799 case R_AARCH64_CALL26:
800 /* This check must match the one in build_got_entries, testing
801 if we really need a PLT slot. */
802 if (sym->st_shndx == SHN_UNDEF)
803 /* We've put the PLT slot offset into r_addend when generating
804 it, and that's what we must use as relocation value (adjusted
805 by section offset of course). */
806 val = s1->plt->sh_addr + rel->r_addend;
807 #ifdef DEBUG_RELOC
808 printf ("reloc %d @ 0x%lx: val=0x%lx name=%s\n", type, addr, val,
809 (char *) symtab_section->link->data + sym->st_name);
810 #endif
811 if (((val - addr) + ((uint64_t)1 << 27)) & ~(uint64_t)0xffffffc)
812 {
813 tcc_error("R_AARCH64_(JUMP|CALL)26 relocation failed (val=%lx, addr=%lx)", addr, val);
814 }
815 *(uint32_t *)ptr = 0x14000000 | (type == R_AARCH64_CALL26) << 31 |
816 ((val - addr) >> 2 & 0x3ffffff);
817 break;
818 case R_AARCH64_ADR_GOT_PAGE: {
819 uint64_t off =
820 (((s1->got->sh_addr +
821 s1->sym_attrs[sym_index].got_offset) >> 12) - (addr >> 12));
822 if ((off + ((uint64_t)1 << 20)) >> 21)
823 tcc_error("R_AARCH64_ADR_GOT_PAGE relocation failed");
824 *(uint32_t *)ptr = (*(uint32_t *)ptr & 0x9f00001f) |
825 (off & 0x1ffffc) << 3 | (off & 3) << 29;
826 break;
827 }
828 case R_AARCH64_LD64_GOT_LO12_NC:
829 *(uint32_t *)ptr = (*(uint32_t *)ptr & 0xfff803ff) |
830 ((s1->got->sh_addr + s1->sym_attrs[sym_index].got_offset)
831 & 0xff8) << 7;
832 break;
833 case R_AARCH64_COPY:
834 break;
835 case R_AARCH64_GLOB_DAT:
836 case R_AARCH64_JUMP_SLOT:
837 /* They don't need addend */
838 #ifdef DEBUG_RELOC
839 printf ("reloc %d @ 0x%lx: val=0x%lx name=%s\n", type, addr,
840 val - rel->r_addend,
841 (char *) symtab_section->link->data + sym->st_name);
842 #endif
843 *(addr_t *)ptr = val - rel->r_addend;
844 break;
845 default:
846 fprintf(stderr, "FIXME: handle reloc type %x at %x [%p] to %x\n",
847 type, (unsigned)addr, ptr, (unsigned)val);
848 break;
849 #elif defined(TCC_TARGET_C67)
850 case R_C60_32:
851 *(int *)ptr += val;
852 break;
853 case R_C60LO16:
854 {
855 uint32_t orig;
856
857 /* put the low 16 bits of the absolute address
858 add to what is already there */
859
860 orig = ((*(int *)(ptr )) >> 7) & 0xffff;
861 orig |= (((*(int *)(ptr+4)) >> 7) & 0xffff) << 16;
862
863 /* patch both at once - assumes always in pairs Low - High */
864
865 *(int *) ptr = (*(int *) ptr & (~(0xffff << 7)) ) | (((val+orig) & 0xffff) << 7);
866 *(int *)(ptr+4) = (*(int *)(ptr+4) & (~(0xffff << 7)) ) | ((((val+orig)>>16) & 0xffff) << 7);
867 }
868 break;
869 case R_C60HI16:
870 break;
871 default:
872 fprintf(stderr,"FIXME: handle reloc type %x at %x [%p] to %x\n",
873 type, (unsigned)addr, ptr, (unsigned)val);
874 break;
875 #elif defined(TCC_TARGET_X86_64)
876 case R_X86_64_64:
877 if (s1->output_type == TCC_OUTPUT_DLL) {
878 esym_index = s1->symtab_to_dynsym[sym_index];
879 qrel->r_offset = rel->r_offset;
880 if (esym_index) {
881 qrel->r_info = ELFW(R_INFO)(esym_index, R_X86_64_64);
882 qrel->r_addend = rel->r_addend;
883 qrel++;
884 break;
885 } else {
886 qrel->r_info = ELFW(R_INFO)(0, R_X86_64_RELATIVE);
887 qrel->r_addend = *(long long *)ptr + val;
888 qrel++;
889 }
890 }
891 *(long long *)ptr += val;
892 break;
893 case R_X86_64_32:
894 case R_X86_64_32S:
895 if (s1->output_type == TCC_OUTPUT_DLL) {
896 /* XXX: this logic may depend on TCC's codegen
897 now TCC uses R_X86_64_32 even for a 64bit pointer */
898 qrel->r_info = ELFW(R_INFO)(0, R_X86_64_RELATIVE);
899 qrel->r_addend = *(int *)ptr + val;
900 qrel++;
901 }
902 *(int *)ptr += val;
903 break;
904
905 case R_X86_64_PC32:
906 if (s1->output_type == TCC_OUTPUT_DLL) {
907 /* DLL relocation */
908 esym_index = s1->symtab_to_dynsym[sym_index];
909 if (esym_index) {
910 qrel->r_offset = rel->r_offset;
911 qrel->r_info = ELFW(R_INFO)(esym_index, R_X86_64_PC32);
912 qrel->r_addend = *(int *)ptr;
913 qrel++;
914 break;
915 }
916 }
917 goto plt32pc32;
918
919 case R_X86_64_PLT32:
920 /* We've put the PLT slot offset into r_addend when generating
921 it, and that's what we must use as relocation value (adjusted
922 by section offset of course). */
923 val = s1->plt->sh_addr + rel->r_addend;
924 /* fallthrough. */
925
926 plt32pc32:
927 {
928 long long diff;
929 diff = (long long)val - addr;
930 if (diff < -2147483648LL || diff > 2147483647LL) {
931 tcc_error("internal error: relocation failed");
932 }
933 *(int *)ptr += diff;
934 }
935 break;
936 case R_X86_64_GLOB_DAT:
937 case R_X86_64_JUMP_SLOT:
938 /* They don't need addend */
939 *(addr_t *)ptr = val - rel->r_addend;
940 break;
941 case R_X86_64_GOTPCREL:
942 *(int *)ptr += (s1->got->sh_addr - addr +
943 s1->sym_attrs[sym_index].got_offset - 4);
944 break;
945 case R_X86_64_GOTTPOFF:
946 *(int *)ptr += val - s1->got->sh_addr;
947 break;
948 case R_X86_64_GOT32:
949 /* we load the got offset */
950 *(int *)ptr += s1->sym_attrs[sym_index].got_offset;
951 break;
952 #else
953 #error unsupported processor
954 #endif
955 }
956 }
957 /* if the relocation is allocated, we change its symbol table */
958 if (sr->sh_flags & SHF_ALLOC)
959 sr->link = s1->dynsym;
960 }
961
962 /* relocate relocation table in 'sr' */
963 static void relocate_rel(TCCState *s1, Section *sr)
964 {
965 Section *s;
966 ElfW_Rel *rel;
967
968 s = s1->sections[sr->sh_info];
969 for_each_elem(sr, 0, rel, ElfW_Rel)
970 rel->r_offset += s->sh_addr;
971 }
972
973 /* count the number of dynamic relocations so that we can reserve
974 their space */
975 static int prepare_dynamic_rel(TCCState *s1, Section *sr)
976 {
977 ElfW_Rel *rel;
978 int sym_index, esym_index, type, count;
979
980 count = 0;
981 for_each_elem(sr, 0, rel, ElfW_Rel) {
982 sym_index = ELFW(R_SYM)(rel->r_info);
983 type = ELFW(R_TYPE)(rel->r_info);
984 switch(type) {
985 #if defined(TCC_TARGET_I386)
986 case R_386_32:
987 #elif defined(TCC_TARGET_X86_64)
988 case R_X86_64_32:
989 case R_X86_64_32S:
990 case R_X86_64_64:
991 #endif
992 count++;
993 break;
994 #if defined(TCC_TARGET_I386)
995 case R_386_PC32:
996 #elif defined(TCC_TARGET_X86_64)
997 case R_X86_64_PC32:
998 #endif
999 esym_index = s1->symtab_to_dynsym[sym_index];
1000 if (esym_index)
1001 count++;
1002 break;
1003 default:
1004 break;
1005 }
1006 }
1007 if (count) {
1008 /* allocate the section */
1009 sr->sh_flags |= SHF_ALLOC;
1010 sr->sh_size = count * sizeof(ElfW_Rel);
1011 }
1012 return count;
1013 }
1014
1015 static struct sym_attr *alloc_sym_attr(TCCState *s1, int index)
1016 {
1017 int n;
1018 struct sym_attr *tab;
1019
1020 if (index >= s1->nb_sym_attrs) {
1021 /* find immediately bigger power of 2 and reallocate array */
1022 n = 1;
1023 while (index >= n)
1024 n *= 2;
1025 tab = tcc_realloc(s1->sym_attrs, n * sizeof(*s1->sym_attrs));
1026 s1->sym_attrs = tab;
1027 memset(s1->sym_attrs + s1->nb_sym_attrs, 0,
1028 (n - s1->nb_sym_attrs) * sizeof(*s1->sym_attrs));
1029 s1->nb_sym_attrs = n;
1030 }
1031 return &s1->sym_attrs[index];
1032 }
1033
1034 /* XXX: suppress that */
1035 static void put32(unsigned char *p, uint32_t val)
1036 {
1037 p[0] = val;
1038 p[1] = val >> 8;
1039 p[2] = val >> 16;
1040 p[3] = val >> 24;
1041 }
1042
1043 #if defined(TCC_TARGET_I386) || defined(TCC_TARGET_ARM) || \
1044 defined(TCC_TARGET_ARM64) || defined(TCC_TARGET_X86_64)
1045 static uint32_t get32(unsigned char *p)
1046 {
1047 return p[0] | (p[1] << 8) | (p[2] << 16) | (p[3] << 24);
1048 }
1049 #endif
1050
1051 static void build_got(TCCState *s1)
1052 {
1053 unsigned char *ptr;
1054
1055 /* if no got, then create it */
1056 s1->got = new_section(s1, ".got", SHT_PROGBITS, SHF_ALLOC | SHF_WRITE);
1057 s1->got->sh_entsize = 4;
1058 add_elf_sym(symtab_section, 0, 4, ELFW(ST_INFO)(STB_GLOBAL, STT_OBJECT),
1059 0, s1->got->sh_num, "_GLOBAL_OFFSET_TABLE_");
1060 ptr = section_ptr_add(s1->got, 3 * PTR_SIZE);
1061 #if PTR_SIZE == 4
1062 /* keep space for _DYNAMIC pointer, if present */
1063 put32(ptr, 0);
1064 /* two dummy got entries */
1065 put32(ptr + 4, 0);
1066 put32(ptr + 8, 0);
1067 #else
1068 /* keep space for _DYNAMIC pointer, if present */
1069 put32(ptr, 0);
1070 put32(ptr + 4, 0);
1071 /* two dummy got entries */
1072 put32(ptr + 8, 0);
1073 put32(ptr + 12, 0);
1074 put32(ptr + 16, 0);
1075 put32(ptr + 20, 0);
1076 #endif
1077 }
1078
1079 /* put a got or plt entry corresponding to a symbol in symtab_section. 'size'
1080 and 'info' can be modifed if more precise info comes from the DLL.
1081 Returns offset of GOT or PLT slot. */
1082 static unsigned long put_got_entry(TCCState *s1,
1083 int reloc_type, unsigned long size, int info,
1084 int sym_index)
1085 {
1086 int index, need_plt_entry;
1087 const char *name;
1088 ElfW(Sym) *sym;
1089 unsigned long offset;
1090 int *ptr;
1091 struct sym_attr *symattr;
1092
1093 if (!s1->got)
1094 build_got(s1);
1095
1096 need_plt_entry =
1097 #ifdef TCC_TARGET_X86_64
1098 (reloc_type == R_X86_64_JUMP_SLOT);
1099 #elif defined(TCC_TARGET_I386)
1100 (reloc_type == R_386_JMP_SLOT);
1101 #elif defined(TCC_TARGET_ARM)
1102 (reloc_type == R_ARM_JUMP_SLOT);
1103 #elif defined(TCC_TARGET_ARM64)
1104 (reloc_type == R_AARCH64_JUMP_SLOT);
1105 #else
1106 0;
1107 #endif
1108
1109 if (need_plt_entry && !s1->plt) {
1110 /* add PLT */
1111 s1->plt = new_section(s1, ".plt", SHT_PROGBITS,
1112 SHF_ALLOC | SHF_EXECINSTR);
1113 s1->plt->sh_entsize = 4;
1114 }
1115
1116 /* If a got/plt entry already exists for that symbol, no need to add one */
1117 if (sym_index < s1->nb_sym_attrs) {
1118 if (need_plt_entry && s1->sym_attrs[sym_index].plt_offset)
1119 return s1->sym_attrs[sym_index].plt_offset;
1120 else if (!need_plt_entry && s1->sym_attrs[sym_index].got_offset)
1121 return s1->sym_attrs[sym_index].got_offset;
1122 }
1123
1124 symattr = alloc_sym_attr(s1, sym_index);
1125
1126 /* Only store the GOT offset if it's not generated for the PLT entry. */
1127 if (!need_plt_entry)
1128 symattr->got_offset = s1->got->data_offset;
1129
1130 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1131 name = (char *) symtab_section->link->data + sym->st_name;
1132 offset = sym->st_value;
1133 #if defined(TCC_TARGET_I386) || defined(TCC_TARGET_X86_64)
1134 if (need_plt_entry) {
1135 Section *plt;
1136 uint8_t *p;
1137 int modrm;
1138 unsigned long relofs;
1139
1140 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
1141 modrm = 0x25;
1142 #else
1143 /* if we build a DLL, we add a %ebx offset */
1144 if (s1->output_type == TCC_OUTPUT_DLL)
1145 modrm = 0xa3;
1146 else
1147 modrm = 0x25;
1148 #endif
1149
1150 /* add a PLT entry */
1151 plt = s1->plt;
1152 if (plt->data_offset == 0) {
1153 /* first plt entry */
1154 p = section_ptr_add(plt, 16);
1155 p[0] = 0xff; /* pushl got + PTR_SIZE */
1156 p[1] = modrm + 0x10;
1157 put32(p + 2, PTR_SIZE);
1158 p[6] = 0xff; /* jmp *(got + PTR_SIZE * 2) */
1159 p[7] = modrm;
1160 put32(p + 8, PTR_SIZE * 2);
1161 }
1162
1163 /* The PLT slot refers to the relocation entry it needs
1164 via offset. The reloc entry is created below, so its
1165 offset is the current data_offset. */
1166 relofs = s1->got->reloc ? s1->got->reloc->data_offset : 0;
1167 symattr->plt_offset = plt->data_offset;
1168 p = section_ptr_add(plt, 16);
1169 p[0] = 0xff; /* jmp *(got + x) */
1170 p[1] = modrm;
1171 put32(p + 2, s1->got->data_offset);
1172 p[6] = 0x68; /* push $xxx */
1173 #ifdef TCC_TARGET_X86_64
1174 /* On x86-64, the relocation is referred to by _index_. */
1175 put32(p + 7, relofs / sizeof (ElfW_Rel));
1176 #else
1177 put32(p + 7, relofs);
1178 #endif
1179 p[11] = 0xe9; /* jmp plt_start */
1180 put32(p + 12, -(plt->data_offset));
1181
1182 /* If this was an UNDEF symbol set the offset in the
1183 dynsymtab to the PLT slot, so that PC32 relocs to it
1184 can be resolved. */
1185 if (sym->st_shndx == SHN_UNDEF)
1186 offset = plt->data_offset - 16;
1187 }
1188 #elif defined(TCC_TARGET_ARM)
1189 if (need_plt_entry) {
1190 Section *plt;
1191 uint8_t *p;
1192
1193 /* if we build a DLL, we add a %ebx offset */
1194 if (s1->output_type == TCC_OUTPUT_DLL)
1195 tcc_error("DLLs unimplemented!");
1196
1197 /* add a PLT entry */
1198 plt = s1->plt;
1199 if (plt->data_offset == 0) {
1200 /* first plt entry */
1201 p = section_ptr_add(plt, 16);
1202 put32(p, 0xe52de004); /* push {lr} */
1203 put32(p+4, 0xe59fe010); /* ldr lr, [pc, #16] */
1204 put32(p+8, 0xe08fe00e); /* add lr, pc, lr */
1205 put32(p+12, 0xe5bef008); /* ldr pc, [lr, #8]! */
1206 }
1207
1208 symattr->plt_offset = plt->data_offset;
1209 if (symattr->plt_thumb_stub) {
1210 p = section_ptr_add(plt, 20);
1211 put32(p, 0x4778); /* bx pc */
1212 put32(p+2, 0x46c0); /* nop */
1213 p += 4;
1214 } else
1215 p = section_ptr_add(plt, 16);
1216 put32(p, 0xe59fc004); /* ldr ip, [pc, #4] ; GOT entry offset */
1217 put32(p+4, 0xe08fc00c); /* add ip, pc, ip ; addr of GOT entry */
1218 put32(p+8, 0xe59cf000); /* ldr pc, [ip] ; jump to GOT entry */
1219 put32(p+12, s1->got->data_offset); /* GOT entry off once patched */
1220
1221 /* the symbol is modified so that it will be relocated to
1222 the PLT */
1223 if (sym->st_shndx == SHN_UNDEF)
1224 offset = plt->data_offset - 16;
1225 }
1226 #elif defined(TCC_TARGET_ARM64)
1227 if (need_plt_entry) {
1228 Section *plt;
1229 uint8_t *p;
1230
1231 if (s1->output_type == TCC_OUTPUT_DLL)
1232 tcc_error("DLLs unimplemented!");
1233
1234 plt = s1->plt;
1235 if (plt->data_offset == 0)
1236 section_ptr_add(plt, 32);
1237 symattr->plt_offset = plt->data_offset;
1238 p = section_ptr_add(plt, 16);
1239 put32(p, s1->got->data_offset);
1240 put32(p + 4, (uint64_t)s1->got->data_offset >> 32);
1241
1242 if (sym->st_shndx == SHN_UNDEF)
1243 offset = plt->data_offset - 16;
1244 }
1245 #elif defined(TCC_TARGET_C67)
1246 if (s1->dynsym) {
1247 tcc_error("C67 got not implemented");
1248 }
1249 #else
1250 #error unsupported CPU
1251 #endif
1252 if (s1->dynsym) {
1253 /* XXX This might generate multiple syms for name. */
1254 index = put_elf_sym(s1->dynsym, offset,
1255 size, info, 0, sym->st_shndx, name);
1256 /* Create the relocation (it's against the GOT for PLT
1257 and GOT relocs). */
1258 put_elf_reloc(s1->dynsym, s1->got,
1259 s1->got->data_offset,
1260 reloc_type, index);
1261 } else {
1262 /* Without .dynsym (i.e. static link or memory output) we
1263 still need relocs against the generated got, so as to fill
1264 the entries with the symbol values (determined later). */
1265 put_elf_reloc(symtab_section, s1->got,
1266 s1->got->data_offset,
1267 reloc_type, sym_index);
1268 }
1269 /* And now create the GOT slot itself. */
1270 ptr = section_ptr_add(s1->got, PTR_SIZE);
1271 *ptr = 0;
1272 if (need_plt_entry)
1273 return symattr->plt_offset;
1274 else
1275 return symattr->got_offset;
1276 }
1277
1278 /* build GOT and PLT entries */
1279 ST_FUNC void build_got_entries(TCCState *s1)
1280 {
1281 Section *s;
1282 ElfW_Rel *rel;
1283 ElfW(Sym) *sym;
1284 int i, type, reloc_type, sym_index;
1285
1286 for(i = 1; i < s1->nb_sections; i++) {
1287 s = s1->sections[i];
1288 if (s->sh_type != SHT_RELX)
1289 continue;
1290 /* no need to handle got relocations */
1291 if (s->link != symtab_section)
1292 continue;
1293 for_each_elem(s, 0, rel, ElfW_Rel) {
1294 type = ELFW(R_TYPE)(rel->r_info);
1295 switch(type) {
1296 #if defined(TCC_TARGET_I386)
1297 case R_386_GOT32:
1298 case R_386_GOTOFF:
1299 case R_386_GOTPC:
1300 case R_386_PLT32:
1301 if (!s1->got)
1302 build_got(s1);
1303 if (type == R_386_GOT32 || type == R_386_PLT32) {
1304 sym_index = ELFW(R_SYM)(rel->r_info);
1305 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1306 /* look at the symbol got offset. If none, then add one */
1307 if (type == R_386_GOT32)
1308 reloc_type = R_386_GLOB_DAT;
1309 else
1310 reloc_type = R_386_JMP_SLOT;
1311 put_got_entry(s1, reloc_type, sym->st_size, sym->st_info,
1312 sym_index);
1313 }
1314 break;
1315 #elif defined(TCC_TARGET_ARM)
1316 case R_ARM_PC24:
1317 case R_ARM_CALL:
1318 case R_ARM_JUMP24:
1319 case R_ARM_GOT32:
1320 case R_ARM_GOTOFF:
1321 case R_ARM_GOTPC:
1322 case R_ARM_PLT32:
1323 if (!s1->got)
1324 build_got(s1);
1325 sym_index = ELFW(R_SYM)(rel->r_info);
1326 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1327 if (type != R_ARM_GOTOFF && type != R_ARM_GOTPC
1328 && sym->st_shndx == SHN_UNDEF) {
1329 unsigned long ofs;
1330 /* look at the symbol got offset. If none, then add one */
1331 if (type == R_ARM_GOT32)
1332 reloc_type = R_ARM_GLOB_DAT;
1333 else
1334 reloc_type = R_ARM_JUMP_SLOT;
1335 ofs = put_got_entry(s1, reloc_type, sym->st_size,
1336 sym->st_info, sym_index);
1337 #ifdef DEBUG_RELOC
1338 printf ("maybegot: %s, %d, %d --> ofs=0x%x\n",
1339 (char *) symtab_section->link->data + sym->st_name,
1340 type, sym->st_shndx, ofs);
1341 #endif
1342 if (type != R_ARM_GOT32) {
1343 addr_t *ptr = (addr_t*)(s1->sections[s->sh_info]->data
1344 + rel->r_offset);
1345 /* x must be signed! */
1346 int x = *ptr & 0xffffff;
1347 x = (x << 8) >> 8;
1348 x <<= 2;
1349 x += ofs;
1350 x >>= 2;
1351 #ifdef DEBUG_RELOC
1352 printf ("insn=0x%x --> 0x%x (x==0x%x)\n", *ptr,
1353 (*ptr & 0xff000000) | x, x);
1354 #endif
1355 *ptr = (*ptr & 0xff000000) | x;
1356 }
1357 }
1358 break;
1359 case R_ARM_THM_JUMP24:
1360 sym_index = ELFW(R_SYM)(rel->r_info);
1361 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1362 /* We are relocating a jump from thumb code to arm code */
1363 if (sym->st_shndx != SHN_UNDEF && !(sym->st_value & 1)) {
1364 int index;
1365 uint8_t *p;
1366 char *name, buf[1024];
1367 Section *text_section;
1368
1369 name = (char *) symtab_section->link->data + sym->st_name;
1370 text_section = s1->sections[sym->st_shndx];
1371 /* Modify reloc to target a thumb stub to switch to ARM */
1372 snprintf(buf, sizeof(buf), "%s_from_thumb", name);
1373 index = put_elf_sym(symtab_section,
1374 text_section->data_offset + 1,
1375 sym->st_size, sym->st_info, 0,
1376 sym->st_shndx, buf);
1377 rel->r_info = ELFW(R_INFO)(index, type);
1378 /* Create a thumb stub fonction to switch to ARM mode */
1379 put_elf_reloc(symtab_section, text_section,
1380 text_section->data_offset + 4, R_ARM_JUMP24,
1381 sym_index);
1382 p = section_ptr_add(text_section, 8);
1383 put32(p, 0x4778); /* bx pc */
1384 put32(p+2, 0x46c0); /* nop */
1385 put32(p+4, 0xeafffffe); /* b $sym */
1386 }
1387 #elif defined(TCC_TARGET_ARM64)
1388 //xx Other cases may be required here:
1389 case R_AARCH64_ADR_GOT_PAGE:
1390 case R_AARCH64_LD64_GOT_LO12_NC:
1391 if (!s1->got)
1392 build_got(s1);
1393 sym_index = ELFW(R_SYM)(rel->r_info);
1394 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1395 reloc_type = R_AARCH64_GLOB_DAT;
1396 put_got_entry(s1, reloc_type, sym->st_size, sym->st_info,
1397 sym_index);
1398 break;
1399
1400 case R_AARCH64_JUMP26:
1401 case R_AARCH64_CALL26:
1402 if (!s1->got)
1403 build_got(s1);
1404 sym_index = ELFW(R_SYM)(rel->r_info);
1405 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1406 if (sym->st_shndx == SHN_UNDEF) {
1407 unsigned long ofs;
1408 reloc_type = R_AARCH64_JUMP_SLOT;
1409 ofs = put_got_entry(s1, reloc_type, sym->st_size,
1410 sym->st_info, sym_index);
1411 /* We store the place of the generated PLT slot
1412 in our addend. */
1413 rel->r_addend += ofs;
1414 }
1415 break;
1416 #elif defined(TCC_TARGET_C67)
1417 case R_C60_GOT32:
1418 case R_C60_GOTOFF:
1419 case R_C60_GOTPC:
1420 case R_C60_PLT32:
1421 if (!s1->got)
1422 build_got(s1);
1423 if (type == R_C60_GOT32 || type == R_C60_PLT32) {
1424 sym_index = ELFW(R_SYM)(rel->r_info);
1425 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1426 /* look at the symbol got offset. If none, then add one */
1427 if (type == R_C60_GOT32)
1428 reloc_type = R_C60_GLOB_DAT;
1429 else
1430 reloc_type = R_C60_JMP_SLOT;
1431 put_got_entry(s1, reloc_type, sym->st_size, sym->st_info,
1432 sym_index);
1433 }
1434 break;
1435 #elif defined(TCC_TARGET_X86_64)
1436 case R_X86_64_GOT32:
1437 case R_X86_64_GOTTPOFF:
1438 case R_X86_64_GOTPCREL:
1439 case R_X86_64_PLT32:
1440 sym_index = ELFW(R_SYM)(rel->r_info);
1441 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1442 if (type == R_X86_64_PLT32 &&
1443 ELFW(ST_VISIBILITY)(sym->st_other) != STV_DEFAULT)
1444 {
1445 rel->r_info = ELFW(R_INFO)(sym_index, R_X86_64_PC32);
1446 break;
1447 }
1448
1449 if (!s1->got)
1450 build_got(s1);
1451 if (type == R_X86_64_GOT32 || type == R_X86_64_GOTPCREL ||
1452 type == R_X86_64_PLT32) {
1453 unsigned long ofs;
1454 /* look at the symbol got offset. If none, then add one */
1455 if (type == R_X86_64_GOT32 || type == R_X86_64_GOTPCREL)
1456 reloc_type = R_X86_64_GLOB_DAT;
1457 else
1458 reloc_type = R_X86_64_JUMP_SLOT;
1459 ofs = put_got_entry(s1, reloc_type, sym->st_size,
1460 sym->st_info, sym_index);
1461 if (type == R_X86_64_PLT32)
1462 /* We store the place of the generated PLT slot
1463 in our addend. */
1464 rel->r_addend += ofs;
1465 }
1466 break;
1467 #else
1468 #error unsupported CPU
1469 #endif
1470 default:
1471 break;
1472 }
1473 }
1474 }
1475 }
1476
1477 ST_FUNC Section *new_symtab(TCCState *s1,
1478 const char *symtab_name, int sh_type, int sh_flags,
1479 const char *strtab_name,
1480 const char *hash_name, int hash_sh_flags)
1481 {
1482 Section *symtab, *strtab, *hash;
1483 int *ptr, nb_buckets;
1484
1485 symtab = new_section(s1, symtab_name, sh_type, sh_flags);
1486 symtab->sh_entsize = sizeof(ElfW(Sym));
1487 strtab = new_section(s1, strtab_name, SHT_STRTAB, sh_flags);
1488 put_elf_str(strtab, "");
1489 symtab->link = strtab;
1490 put_elf_sym(symtab, 0, 0, 0, 0, 0, NULL);
1491
1492 nb_buckets = 1;
1493
1494 hash = new_section(s1, hash_name, SHT_HASH, hash_sh_flags);
1495 hash->sh_entsize = sizeof(int);
1496 symtab->hash = hash;
1497 hash->link = symtab;
1498
1499 ptr = section_ptr_add(hash, (2 + nb_buckets + 1) * sizeof(int));
1500 ptr[0] = nb_buckets;
1501 ptr[1] = 1;
1502 memset(ptr + 2, 0, (nb_buckets + 1) * sizeof(int));
1503 return symtab;
1504 }
1505
1506 /* put dynamic tag */
1507 static void put_dt(Section *dynamic, int dt, addr_t val)
1508 {
1509 ElfW(Dyn) *dyn;
1510 dyn = section_ptr_add(dynamic, sizeof(ElfW(Dyn)));
1511 dyn->d_tag = dt;
1512 dyn->d_un.d_val = val;
1513 }
1514
1515 static void add_init_array_defines(TCCState *s1, const char *section_name)
1516 {
1517 Section *s;
1518 long end_offset;
1519 char sym_start[1024];
1520 char sym_end[1024];
1521
1522 snprintf(sym_start, sizeof(sym_start), "__%s_start", section_name + 1);
1523 snprintf(sym_end, sizeof(sym_end), "__%s_end", section_name + 1);
1524
1525 s = find_section(s1, section_name);
1526 if (!s) {
1527 end_offset = 0;
1528 s = data_section;
1529 } else {
1530 end_offset = s->data_offset;
1531 }
1532
1533 add_elf_sym(symtab_section,
1534 0, 0,
1535 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1536 s->sh_num, sym_start);
1537 add_elf_sym(symtab_section,
1538 end_offset, 0,
1539 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1540 s->sh_num, sym_end);
1541 }
1542
1543 static int tcc_add_support(TCCState *s1, const char *filename)
1544 {
1545 char buf[1024];
1546 snprintf(buf, sizeof(buf), "%s/%s/%s", s1->tcc_lib_path,
1547 /* an cpu specific path inside tcc_lib_path, mainly for keeping libtcc1.a */
1548 #ifdef TCC_TARGET_I386
1549 "i386"
1550 #endif
1551 #ifdef TCC_TARGET_X86_64
1552 "x86-64"
1553 #endif
1554 #ifdef TCC_TARGET_ARM
1555 "arm"
1556 #endif
1557 #ifdef TCC_TARGET_ARM64
1558 "arm64"
1559 #endif
1560 #ifdef TCC_TARGET_C67
1561 "C67"
1562 #endif
1563 ,filename);
1564
1565 return tcc_add_file(s1, buf);
1566 }
1567
1568 ST_FUNC void tcc_add_bcheck(TCCState *s1)
1569 {
1570 #ifdef CONFIG_TCC_BCHECK
1571 unsigned long *ptr;
1572 Section *init_section;
1573 unsigned char *pinit;
1574 int sym_index;
1575
1576 if (0 == s1->do_bounds_check)
1577 return;
1578
1579 /* XXX: add an object file to do that */
1580 ptr = section_ptr_add(bounds_section, sizeof(unsigned long));
1581 *ptr = 0;
1582 add_elf_sym(symtab_section, 0, 0,
1583 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1584 bounds_section->sh_num, "__bounds_start");
1585 #ifdef TCC_TARGET_I386
1586 if (s1->output_type != TCC_OUTPUT_MEMORY) {
1587 /* add 'call __bound_init()' in .init section */
1588 init_section = find_section(s1, ".init");
1589 pinit = section_ptr_add(init_section, 5);
1590 pinit[0] = 0xe8;
1591 put32(pinit + 1, -4);
1592 tcc_add_support(s1, "bcheck.o");
1593 sym_index = find_elf_sym(symtab_section, "__bound_init");
1594 if (!sym_index)
1595 tcc_error("__bound_init not defined");
1596 put_elf_reloc(symtab_section, init_section,
1597 init_section->data_offset - 4, R_386_PC32, sym_index);
1598 }
1599 #endif
1600 #endif
1601 }
1602
1603 /* add tcc runtime libraries */
1604 ST_FUNC void tcc_add_runtime(TCCState *s1)
1605 {
1606 /* add libc */
1607 if (!s1->nostdlib) {
1608 tcc_add_library(s1, "c");
1609 #ifdef CONFIG_USE_LIBGCC
1610 if (!s1->static_link) {
1611 tcc_add_file(s1, TCC_LIBGCC);
1612 }
1613 #endif
1614 tcc_add_support(s1, "libtcc1.a");
1615 }
1616
1617 /* tcc_add_bcheck tries to relocate a call to __bound_init in _init so
1618 libtcc1.a must be loaded before for __bound_init to be defined and
1619 crtn.o must be loaded after to not finalize _init too early. */
1620 tcc_add_bcheck(s1);
1621
1622 if (!s1->nostdlib) {
1623 /* add crt end if not memory output */
1624 if (s1->output_type != TCC_OUTPUT_MEMORY)
1625 tcc_add_crt(s1, "crtn.o");
1626 }
1627 }
1628
1629 /* add various standard linker symbols (must be done after the
1630 sections are filled (for example after allocating common
1631 symbols)) */
1632 ST_FUNC void tcc_add_linker_symbols(TCCState *s1)
1633 {
1634 char buf[1024];
1635 int i;
1636 Section *s;
1637
1638 add_elf_sym(symtab_section,
1639 text_section->data_offset, 0,
1640 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1641 text_section->sh_num, "_etext");
1642 add_elf_sym(symtab_section,
1643 data_section->data_offset, 0,
1644 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1645 data_section->sh_num, "_edata");
1646 add_elf_sym(symtab_section,
1647 bss_section->data_offset, 0,
1648 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1649 bss_section->sh_num, "_end");
1650 /* horrible new standard ldscript defines */
1651 add_init_array_defines(s1, ".preinit_array");
1652 add_init_array_defines(s1, ".init_array");
1653 add_init_array_defines(s1, ".fini_array");
1654
1655 /* add start and stop symbols for sections whose name can be
1656 expressed in C */
1657 for(i = 1; i < s1->nb_sections; i++) {
1658 s = s1->sections[i];
1659 if (s->sh_type == SHT_PROGBITS &&
1660 (s->sh_flags & SHF_ALLOC)) {
1661 const char *p;
1662 int ch;
1663
1664 /* check if section name can be expressed in C */
1665 p = s->name;
1666 for(;;) {
1667 ch = *p;
1668 if (!ch)
1669 break;
1670 if (!isid(ch) && !isnum(ch))
1671 goto next_sec;
1672 p++;
1673 }
1674 snprintf(buf, sizeof(buf), "__start_%s", s->name);
1675 add_elf_sym(symtab_section,
1676 0, 0,
1677 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1678 s->sh_num, buf);
1679 snprintf(buf, sizeof(buf), "__stop_%s", s->name);
1680 add_elf_sym(symtab_section,
1681 s->data_offset, 0,
1682 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1683 s->sh_num, buf);
1684 }
1685 next_sec: ;
1686 }
1687 }
1688
1689 static void tcc_output_binary(TCCState *s1, FILE *f,
1690 const int *sec_order)
1691 {
1692 Section *s;
1693 int i, offset, size;
1694
1695 offset = 0;
1696 for(i=1;i<s1->nb_sections;i++) {
1697 s = s1->sections[sec_order[i]];
1698 if (s->sh_type != SHT_NOBITS &&
1699 (s->sh_flags & SHF_ALLOC)) {
1700 while (offset < s->sh_offset) {
1701 fputc(0, f);
1702 offset++;
1703 }
1704 size = s->sh_size;
1705 fwrite(s->data, 1, size, f);
1706 offset += size;
1707 }
1708 }
1709 }
1710
1711 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1712 #define HAVE_PHDR 1
1713 #define EXTRA_RELITEMS 14
1714
1715 /* move the relocation value from .dynsym to .got */
1716 void patch_dynsym_undef(TCCState *s1, Section *s)
1717 {
1718 uint32_t *gotd = (void *)s1->got->data;
1719 ElfW(Sym) *sym;
1720
1721 gotd += 3; /* dummy entries in .got */
1722 /* relocate symbols in .dynsym */
1723 for_each_elem(s, 1, sym, ElfW(Sym)) {
1724 if (sym->st_shndx == SHN_UNDEF) {
1725 *gotd++ = sym->st_value + 6; /* XXX 6 is magic ? */
1726 sym->st_value = 0;
1727 }
1728 }
1729 }
1730 #else
1731 #define HAVE_PHDR 1
1732 #define EXTRA_RELITEMS 9
1733
1734 /* zero plt offsets of weak symbols in .dynsym */
1735 void patch_dynsym_undef(TCCState *s1, Section *s)
1736 {
1737 ElfW(Sym) *sym;
1738
1739 for_each_elem(s, 1, sym, ElfW(Sym))
1740 if (sym->st_shndx == SHN_UNDEF && ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
1741 sym->st_value = 0;
1742 }
1743 #endif
1744
1745 ST_FUNC void fill_got_entry(TCCState *s1, ElfW_Rel *rel)
1746 {
1747 int sym_index = ELFW(R_SYM) (rel->r_info);
1748 ElfW(Sym) *sym = &((ElfW(Sym) *) symtab_section->data)[sym_index];
1749 unsigned long offset;
1750
1751 if (sym_index >= s1->nb_sym_attrs)
1752 return;
1753 offset = s1->sym_attrs[sym_index].got_offset;
1754 section_reserve(s1->got, offset + PTR_SIZE);
1755 #ifdef TCC_TARGET_X86_64
1756 /* only works for x86-64 */
1757 put32(s1->got->data + offset + 4, sym->st_value >> 32);
1758 #endif
1759 put32(s1->got->data + offset, sym->st_value & 0xffffffff);
1760 }
1761
1762 /* Perform relocation to GOT or PLT entries */
1763 ST_FUNC void fill_got(TCCState *s1)
1764 {
1765 Section *s;
1766 ElfW_Rel *rel;
1767 int i;
1768
1769 for(i = 1; i < s1->nb_sections; i++) {
1770 s = s1->sections[i];
1771 if (s->sh_type != SHT_RELX)
1772 continue;
1773 /* no need to handle got relocations */
1774 if (s->link != symtab_section)
1775 continue;
1776 for_each_elem(s, 0, rel, ElfW_Rel) {
1777 switch (ELFW(R_TYPE) (rel->r_info)) {
1778 case R_X86_64_GOT32:
1779 case R_X86_64_GOTPCREL:
1780 case R_X86_64_PLT32:
1781 fill_got_entry(s1, rel);
1782 break;
1783 }
1784 }
1785 }
1786 }
1787
1788 /* Bind symbols of executable: resolve undefined symbols from exported symbols
1789 in shared libraries and export non local defined symbols to shared libraries
1790 if -rdynamic switch was given on command line */
1791 static void bind_exe_dynsyms(TCCState *s1)
1792 {
1793 const char *name;
1794 int sym_index, index;
1795 ElfW(Sym) *sym, *esym;
1796 int type;
1797
1798 /* Resolve undefined symbols from dynamic symbols. When there is a match:
1799 - if STT_FUNC or STT_GNU_IFUNC symbol -> add it in PLT
1800 - if STT_OBJECT symbol -> add it in .bss section with suitable reloc */
1801 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
1802 if (sym->st_shndx == SHN_UNDEF) {
1803 name = (char *) symtab_section->link->data + sym->st_name;
1804 sym_index = find_elf_sym(s1->dynsymtab_section, name);
1805 if (sym_index) {
1806 esym = &((ElfW(Sym) *)s1->dynsymtab_section->data)[sym_index];
1807 type = ELFW(ST_TYPE)(esym->st_info);
1808 if ((type == STT_FUNC) || (type == STT_GNU_IFUNC)) {
1809 /* Indirect functions shall have STT_FUNC type in executable
1810 * dynsym section. Indeed, a dlsym call following a lazy
1811 * resolution would pick the symbol value from the
1812 * executable dynsym entry which would contain the address
1813 * of the function wanted by the caller of dlsym instead of
1814 * the address of the function that would return that
1815 * address */
1816 put_got_entry(s1, R_JMP_SLOT, esym->st_size,
1817 ELFW(ST_INFO)(STB_GLOBAL,STT_FUNC),
1818 sym - (ElfW(Sym) *)symtab_section->data);
1819 } else if (type == STT_OBJECT) {
1820 unsigned long offset;
1821 ElfW(Sym) *dynsym;
1822 offset = bss_section->data_offset;
1823 /* XXX: which alignment ? */
1824 offset = (offset + 16 - 1) & -16;
1825 index = put_elf_sym(s1->dynsym, offset, esym->st_size,
1826 esym->st_info, 0, bss_section->sh_num,
1827 name);
1828 /* Ensure R_COPY works for weak symbol aliases */
1829 if (ELFW(ST_BIND)(esym->st_info) == STB_WEAK) {
1830 for_each_elem(s1->dynsymtab_section, 1, dynsym, ElfW(Sym)) {
1831 if ((dynsym->st_value == esym->st_value)
1832 && (ELFW(ST_BIND)(dynsym->st_info) == STB_GLOBAL)) {
1833 char *dynname = (char *) s1->dynsymtab_section->link->data
1834 + dynsym->st_name;
1835 put_elf_sym(s1->dynsym, offset, dynsym->st_size,
1836 dynsym->st_info, 0,
1837 bss_section->sh_num, dynname);
1838 break;
1839 }
1840 }
1841 }
1842 put_elf_reloc(s1->dynsym, bss_section,
1843 offset, R_COPY, index);
1844 offset += esym->st_size;
1845 bss_section->data_offset = offset;
1846 }
1847 } else {
1848 /* STB_WEAK undefined symbols are accepted */
1849 /* XXX: _fp_hw seems to be part of the ABI, so we ignore it */
1850 if (ELFW(ST_BIND)(sym->st_info) == STB_WEAK ||
1851 !strcmp(name, "_fp_hw")) {
1852 } else {
1853 tcc_error_noabort("undefined symbol '%s'", name);
1854 }
1855 }
1856 } else if (s1->rdynamic && ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
1857 /* if -rdynamic option, then export all non local symbols */
1858 name = (char *) symtab_section->link->data + sym->st_name;
1859 put_elf_sym(s1->dynsym, sym->st_value, sym->st_size, sym->st_info,
1860 0, sym->st_shndx, name);
1861 }
1862 }
1863 }
1864
1865 /* Bind symbols of libraries: export non local symbols of executable that
1866 resolve undefined symbols of shared libraries */
1867 static void bind_libs_dynsyms(TCCState *s1)
1868 {
1869 const char *name;
1870 int sym_index;
1871 ElfW(Sym) *sym, *esym;
1872
1873 /* now look at unresolved dynamic symbols and export
1874 corresponding symbol */
1875 for_each_elem(s1->dynsymtab_section, 1, esym, ElfW(Sym)) {
1876 if (esym->st_shndx == SHN_UNDEF) {
1877 name = (char *) s1->dynsymtab_section->link->data + esym->st_name;
1878 sym_index = find_elf_sym(symtab_section, name);
1879 if (sym_index) {
1880 /* XXX: avoid adding a symbol if already present because of
1881 -rdynamic ? */
1882 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1883 put_elf_sym(s1->dynsym, sym->st_value, sym->st_size,
1884 sym->st_info, 0, sym->st_shndx, name);
1885 } else {
1886 /* weak symbols can stay undefined */
1887 if (ELFW(ST_BIND)(esym->st_info) != STB_WEAK)
1888 tcc_warning("undefined dynamic symbol '%s'", name);
1889 }
1890 }
1891 }
1892 }
1893
1894 /* Export all non local symbols (for shared libraries) */
1895 static void export_global_syms(TCCState *s1)
1896 {
1897 int nb_syms, dynindex, index;
1898 const char *name;
1899 ElfW(Sym) *sym;
1900
1901 nb_syms = symtab_section->data_offset / sizeof(ElfW(Sym));
1902 s1->symtab_to_dynsym = tcc_mallocz(sizeof(int) * nb_syms);
1903 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
1904 if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
1905 name = (char *) symtab_section->link->data + sym->st_name;
1906 dynindex = put_elf_sym(s1->dynsym, sym->st_value, sym->st_size,
1907 sym->st_info, 0, sym->st_shndx, name);
1908 index = sym - (ElfW(Sym) *) symtab_section->data;
1909 s1->symtab_to_dynsym[index] = dynindex;
1910 }
1911 }
1912 }
1913
1914 /* relocate the PLT: compute addresses and offsets in the PLT now that final
1915 address for PLT and GOT are known (see fill_program_header) */
1916 ST_FUNC void relocate_plt(TCCState *s1)
1917 {
1918 uint8_t *p, *p_end;
1919
1920 if (!s1->plt)
1921 return;
1922
1923 p = s1->plt->data;
1924 p_end = p + s1->plt->data_offset;
1925 if (p < p_end) {
1926 #if defined(TCC_TARGET_I386)
1927 put32(p + 2, get32(p + 2) + s1->got->sh_addr);
1928 put32(p + 8, get32(p + 8) + s1->got->sh_addr);
1929 p += 16;
1930 while (p < p_end) {
1931 put32(p + 2, get32(p + 2) + s1->got->sh_addr);
1932 p += 16;
1933 }
1934 #elif defined(TCC_TARGET_X86_64)
1935 int x = s1->got->sh_addr - s1->plt->sh_addr - 6;
1936 put32(p + 2, get32(p + 2) + x);
1937 put32(p + 8, get32(p + 8) + x - 6);
1938 p += 16;
1939 while (p < p_end) {
1940 put32(p + 2, get32(p + 2) + x + s1->plt->data - p);
1941 p += 16;
1942 }
1943 #elif defined(TCC_TARGET_ARM)
1944 int x;
1945 x=s1->got->sh_addr - s1->plt->sh_addr - 12;
1946 p += 16;
1947 while (p < p_end) {
1948 if (get32(p) == 0x46c04778) /* PLT Thumb stub present */
1949 p += 4;
1950 put32(p + 12, x + get32(p + 12) + s1->plt->data - p);
1951 p += 16;
1952 }
1953 #elif defined(TCC_TARGET_ARM64)
1954 uint64_t plt = s1->plt->sh_addr;
1955 uint64_t got = s1->got->sh_addr;
1956 uint64_t off = (got >> 12) - (plt >> 12);
1957 if ((off + ((uint32_t)1 << 20)) >> 21)
1958 tcc_error("Failed relocating PLT (off=0x%lx, got=0x%lx, plt=0x%lx)", off, got, plt);
1959 put32(p, 0xa9bf7bf0); // stp x16,x30,[sp,#-16]!
1960 put32(p + 4, (0x90000010 | // adrp x16,...
1961 (off & 0x1ffffc) << 3 | (off & 3) << 29));
1962 put32(p + 8, (0xf9400211 | // ldr x17,[x16,#...]
1963 (got & 0xff8) << 7));
1964 put32(p + 12, (0x91000210 | // add x16,x16,#...
1965 (got & 0xfff) << 10));
1966 put32(p + 16, 0xd61f0220); // br x17
1967 put32(p + 20, 0xd503201f); // nop
1968 put32(p + 24, 0xd503201f); // nop
1969 put32(p + 28, 0xd503201f); // nop
1970 p += 32;
1971 while (p < p_end) {
1972 uint64_t pc = plt + (p - s1->plt->data);
1973 uint64_t addr = got +
1974 (get32(p) | (uint64_t)get32(p + 4) << 32);
1975 uint32_t off = (addr >> 12) - (pc >> 12);
1976 if ((off + ((uint32_t)1 << 20)) >> 21)
1977 tcc_error("Failed relocating PLT (off=0x%lx, addr=0x%lx, pc=0x%lx)", off, addr, pc);
1978 put32(p, (0x90000010 | // adrp x16,...
1979 (off & 0x1ffffc) << 3 | (off & 3) << 29));
1980 put32(p + 4, (0xf9400211 | // ldr x17,[x16,#...]
1981 (addr & 0xff8) << 7));
1982 put32(p + 8, (0x91000210 | // add x16,x16,#...
1983 (addr & 0xfff) << 10));
1984 put32(p + 12, 0xd61f0220); // br x17
1985 p += 16;
1986 }
1987 #elif defined(TCC_TARGET_C67)
1988 /* XXX: TODO */
1989 #else
1990 #error unsupported CPU
1991 #endif
1992 }
1993 }
1994
1995 /* Allocate strings for section names and decide if an unallocated section
1996 should be output.
1997
1998 NOTE: the strsec section comes last, so its size is also correct ! */
1999 static void alloc_sec_names(TCCState *s1, int file_type, Section *strsec)
2000 {
2001 int i;
2002 Section *s;
2003
2004 /* Allocate strings for section names */
2005 for(i = 1; i < s1->nb_sections; i++) {
2006 s = s1->sections[i];
2007 s->sh_name = put_elf_str(strsec, s->name);
2008 /* when generating a DLL, we include relocations but we may
2009 patch them */
2010 if (file_type == TCC_OUTPUT_DLL &&
2011 s->sh_type == SHT_RELX &&
2012 !(s->sh_flags & SHF_ALLOC)) {
2013 /* gr: avoid bogus relocs for empty (debug) sections */
2014 if (s1->sections[s->sh_info]->sh_flags & SHF_ALLOC)
2015 prepare_dynamic_rel(s1, s);
2016 else if (s1->do_debug)
2017 s->sh_size = s->data_offset;
2018 } else if (s1->do_debug ||
2019 file_type == TCC_OUTPUT_OBJ ||
2020 (s->sh_flags & SHF_ALLOC) ||
2021 i == (s1->nb_sections - 1)) {
2022 /* we output all sections if debug or object file */
2023 s->sh_size = s->data_offset;
2024 }
2025 }
2026 }
2027
2028 /* Info to be copied in dynamic section */
2029 struct dyn_inf {
2030 Section *dynamic;
2031 Section *dynstr;
2032 unsigned long dyn_rel_off;
2033 addr_t rel_addr;
2034 addr_t rel_size;
2035 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2036 addr_t bss_addr;
2037 addr_t bss_size;
2038 #endif
2039 };
2040
2041 /* Assign sections to segments and decide how are sections laid out when loaded
2042 in memory. This function also fills corresponding program headers. */
2043 static int layout_sections(TCCState *s1, ElfW(Phdr) *phdr, int phnum,
2044 Section *interp, Section* strsec,
2045 struct dyn_inf *dyninf, int *sec_order)
2046 {
2047 int i, j, k, file_type, sh_order_index, file_offset;
2048 unsigned long s_align;
2049 long long tmp;
2050 addr_t addr;
2051 ElfW(Phdr) *ph;
2052 Section *s;
2053
2054 file_type = s1->output_type;
2055 sh_order_index = 1;
2056 file_offset = 0;
2057 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF)
2058 file_offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr));
2059 s_align = ELF_PAGE_SIZE;
2060 if (s1->section_align)
2061 s_align = s1->section_align;
2062
2063 if (phnum > 0) {
2064 if (s1->has_text_addr) {
2065 int a_offset, p_offset;
2066 addr = s1->text_addr;
2067 /* we ensure that (addr % ELF_PAGE_SIZE) == file_offset %
2068 ELF_PAGE_SIZE */
2069 a_offset = (int) (addr & (s_align - 1));
2070 p_offset = file_offset & (s_align - 1);
2071 if (a_offset < p_offset)
2072 a_offset += s_align;
2073 file_offset += (a_offset - p_offset);
2074 } else {
2075 if (file_type == TCC_OUTPUT_DLL)
2076 addr = 0;
2077 else
2078 addr = ELF_START_ADDR;
2079 /* compute address after headers */
2080 addr += (file_offset & (s_align - 1));
2081 }
2082
2083 ph = &phdr[0];
2084 /* Leave one program headers for the program interpreter and one for
2085 the program header table itself if needed. These are done later as
2086 they require section layout to be done first. */
2087 if (interp)
2088 ph += 1 + HAVE_PHDR;
2089
2090 /* dynamic relocation table information, for .dynamic section */
2091 dyninf->rel_addr = dyninf->rel_size = 0;
2092 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2093 dyninf->bss_addr = dyninf->bss_size = 0;
2094 #endif
2095
2096 for(j = 0; j < 2; j++) {
2097 ph->p_type = PT_LOAD;
2098 if (j == 0)
2099 ph->p_flags = PF_R | PF_X;
2100 else
2101 ph->p_flags = PF_R | PF_W;
2102 ph->p_align = s_align;
2103
2104 /* Decide the layout of sections loaded in memory. This must
2105 be done before program headers are filled since they contain
2106 info about the layout. We do the following ordering: interp,
2107 symbol tables, relocations, progbits, nobits */
2108 /* XXX: do faster and simpler sorting */
2109 for(k = 0; k < 5; k++) {
2110 for(i = 1; i < s1->nb_sections; i++) {
2111 s = s1->sections[i];
2112 /* compute if section should be included */
2113 if (j == 0) {
2114 if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) !=
2115 SHF_ALLOC)
2116 continue;
2117 } else {
2118 if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) !=
2119 (SHF_ALLOC | SHF_WRITE))
2120 continue;
2121 }
2122 if (s == interp) {
2123 if (k != 0)
2124 continue;
2125 } else if (s->sh_type == SHT_DYNSYM ||
2126 s->sh_type == SHT_STRTAB ||
2127 s->sh_type == SHT_HASH) {
2128 if (k != 1)
2129 continue;
2130 } else if (s->sh_type == SHT_RELX) {
2131 if (k != 2)
2132 continue;
2133 } else if (s->sh_type == SHT_NOBITS) {
2134 if (k != 4)
2135 continue;
2136 } else {
2137 if (k != 3)
2138 continue;
2139 }
2140 sec_order[sh_order_index++] = i;
2141
2142 /* section matches: we align it and add its size */
2143 tmp = addr;
2144 addr = (addr + s->sh_addralign - 1) &
2145 ~(s->sh_addralign - 1);
2146 file_offset += (int) ( addr - tmp );
2147 s->sh_offset = file_offset;
2148 s->sh_addr = addr;
2149
2150 /* update program header infos */
2151 if (ph->p_offset == 0) {
2152 ph->p_offset = file_offset;
2153 ph->p_vaddr = addr;
2154 ph->p_paddr = ph->p_vaddr;
2155 }
2156 /* update dynamic relocation infos */
2157 if (s->sh_type == SHT_RELX) {
2158 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2159 if (!strcmp(strsec->data + s->sh_name, ".rel.got")) {
2160 dyninf->rel_addr = addr;
2161 dyninf->rel_size += s->sh_size; /* XXX only first rel. */
2162 }
2163 if (!strcmp(strsec->data + s->sh_name, ".rel.bss")) {
2164 dyninf->bss_addr = addr;
2165 dyninf->bss_size = s->sh_size; /* XXX only first rel. */
2166 }
2167 #else
2168 if (dyninf->rel_size == 0)
2169 dyninf->rel_addr = addr;
2170 dyninf->rel_size += s->sh_size;
2171 #endif
2172 }
2173 addr += s->sh_size;
2174 if (s->sh_type != SHT_NOBITS)
2175 file_offset += s->sh_size;
2176 }
2177 }
2178 if (j == 0) {
2179 /* Make the first PT_LOAD segment include the program
2180 headers itself (and the ELF header as well), it'll
2181 come out with same memory use but will make various
2182 tools like binutils strip work better. */
2183 ph->p_offset &= ~(ph->p_align - 1);
2184 ph->p_vaddr &= ~(ph->p_align - 1);
2185 ph->p_paddr &= ~(ph->p_align - 1);
2186 }
2187 ph->p_filesz = file_offset - ph->p_offset;
2188 ph->p_memsz = addr - ph->p_vaddr;
2189 ph++;
2190 if (j == 0) {
2191 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF) {
2192 /* if in the middle of a page, we duplicate the page in
2193 memory so that one copy is RX and the other is RW */
2194 if ((addr & (s_align - 1)) != 0)
2195 addr += s_align;
2196 } else {
2197 addr = (addr + s_align - 1) & ~(s_align - 1);
2198 file_offset = (file_offset + s_align - 1) & ~(s_align - 1);
2199 }
2200 }
2201 }
2202 }
2203
2204 /* all other sections come after */
2205 for(i = 1; i < s1->nb_sections; i++) {
2206 s = s1->sections[i];
2207 if (phnum > 0 && (s->sh_flags & SHF_ALLOC))
2208 continue;
2209 sec_order[sh_order_index++] = i;
2210
2211 file_offset = (file_offset + s->sh_addralign - 1) &
2212 ~(s->sh_addralign - 1);
2213 s->sh_offset = file_offset;
2214 if (s->sh_type != SHT_NOBITS)
2215 file_offset += s->sh_size;
2216 }
2217
2218 return file_offset;
2219 }
2220
2221 static void fill_unloadable_phdr(ElfW(Phdr) *phdr, int phnum, Section *interp,
2222 Section *dynamic)
2223 {
2224 ElfW(Phdr) *ph;
2225
2226 /* if interpreter, then add corresponding program header */
2227 if (interp) {
2228 ph = &phdr[0];
2229
2230 if (HAVE_PHDR)
2231 {
2232 int len = phnum * sizeof(ElfW(Phdr));
2233
2234 ph->p_type = PT_PHDR;
2235 ph->p_offset = sizeof(ElfW(Ehdr));
2236 ph->p_vaddr = interp->sh_addr - len;
2237 ph->p_paddr = ph->p_vaddr;
2238 ph->p_filesz = ph->p_memsz = len;
2239 ph->p_flags = PF_R | PF_X;
2240 ph->p_align = 4; /* interp->sh_addralign; */
2241 ph++;
2242 }
2243
2244 ph->p_type = PT_INTERP;
2245 ph->p_offset = interp->sh_offset;
2246 ph->p_vaddr = interp->sh_addr;
2247 ph->p_paddr = ph->p_vaddr;
2248 ph->p_filesz = interp->sh_size;
2249 ph->p_memsz = interp->sh_size;
2250 ph->p_flags = PF_R;
2251 ph->p_align = interp->sh_addralign;
2252 }
2253
2254 /* if dynamic section, then add corresponding program header */
2255 if (dynamic) {
2256 ph = &phdr[phnum - 1];
2257
2258 ph->p_type = PT_DYNAMIC;
2259 ph->p_offset = dynamic->sh_offset;
2260 ph->p_vaddr = dynamic->sh_addr;
2261 ph->p_paddr = ph->p_vaddr;
2262 ph->p_filesz = dynamic->sh_size;
2263 ph->p_memsz = dynamic->sh_size;
2264 ph->p_flags = PF_R | PF_W;
2265 ph->p_align = dynamic->sh_addralign;
2266 }
2267 }
2268
2269 /* Fill the dynamic section with tags describing the address and size of
2270 sections */
2271 static void fill_dynamic(TCCState *s1, struct dyn_inf *dyninf)
2272 {
2273 Section *dynamic;
2274
2275 dynamic = dyninf->dynamic;
2276
2277 /* put dynamic section entries */
2278 dynamic->data_offset = dyninf->dyn_rel_off;
2279 put_dt(dynamic, DT_HASH, s1->dynsym->hash->sh_addr);
2280 put_dt(dynamic, DT_STRTAB, dyninf->dynstr->sh_addr);
2281 put_dt(dynamic, DT_SYMTAB, s1->dynsym->sh_addr);
2282 put_dt(dynamic, DT_STRSZ, dyninf->dynstr->data_offset);
2283 put_dt(dynamic, DT_SYMENT, sizeof(ElfW(Sym)));
2284 #if defined(TCC_TARGET_ARM64) || defined(TCC_TARGET_X86_64)
2285 put_dt(dynamic, DT_RELA, dyninf->rel_addr);
2286 put_dt(dynamic, DT_RELASZ, dyninf->rel_size);
2287 put_dt(dynamic, DT_RELAENT, sizeof(ElfW_Rel));
2288 #else
2289 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2290 put_dt(dynamic, DT_PLTGOT, s1->got->sh_addr);
2291 put_dt(dynamic, DT_PLTRELSZ, dyninf->rel_size);
2292 put_dt(dynamic, DT_JMPREL, dyninf->rel_addr);
2293 put_dt(dynamic, DT_PLTREL, DT_REL);
2294 put_dt(dynamic, DT_REL, dyninf->bss_addr);
2295 put_dt(dynamic, DT_RELSZ, dyninf->bss_size);
2296 #else
2297 put_dt(dynamic, DT_REL, dyninf->rel_addr);
2298 put_dt(dynamic, DT_RELSZ, dyninf->rel_size);
2299 put_dt(dynamic, DT_RELENT, sizeof(ElfW_Rel));
2300 #endif
2301 #endif
2302 if (s1->do_debug)
2303 put_dt(dynamic, DT_DEBUG, 0);
2304 put_dt(dynamic, DT_NULL, 0);
2305 }
2306
2307 /* Relocate remaining sections and symbols (that is those not related to
2308 dynamic linking) */
2309 static int final_sections_reloc(TCCState *s1)
2310 {
2311 int i;
2312 Section *s;
2313
2314 relocate_syms(s1, 0);
2315
2316 if (s1->nb_errors != 0)
2317 return -1;
2318
2319 /* relocate sections */
2320 /* XXX: ignore sections with allocated relocations ? */
2321 for(i = 1; i < s1->nb_sections; i++) {
2322 s = s1->sections[i];
2323 #ifdef TCC_TARGET_I386
2324 if (s->reloc && s != s1->got && (s->sh_flags & SHF_ALLOC)) //gr
2325 /* On X86 gdb 7.3 works in any case but gdb 6.6 will crash if SHF_ALLOC
2326 checking is removed */
2327 #else
2328 if (s->reloc && s != s1->got)
2329 /* On X86_64 gdb 7.3 will crash if SHF_ALLOC checking is present */
2330 #endif
2331 relocate_section(s1, s);
2332 }
2333
2334 /* relocate relocation entries if the relocation tables are
2335 allocated in the executable */
2336 for(i = 1; i < s1->nb_sections; i++) {
2337 s = s1->sections[i];
2338 if ((s->sh_flags & SHF_ALLOC) &&
2339 s->sh_type == SHT_RELX) {
2340 relocate_rel(s1, s);
2341 }
2342 }
2343 return 0;
2344 }
2345
2346 /* Create an ELF file on disk.
2347 This function handle ELF specific layout requirements */
2348 static void tcc_output_elf(TCCState *s1, FILE *f, int phnum, ElfW(Phdr) *phdr,
2349 int file_offset, int *sec_order)
2350 {
2351 int i, shnum, offset, size, file_type;
2352 Section *s;
2353 ElfW(Ehdr) ehdr;
2354 ElfW(Shdr) shdr, *sh;
2355
2356 file_type = s1->output_type;
2357 shnum = s1->nb_sections;
2358
2359 memset(&ehdr, 0, sizeof(ehdr));
2360
2361 if (phnum > 0) {
2362 ehdr.e_phentsize = sizeof(ElfW(Phdr));
2363 ehdr.e_phnum = phnum;
2364 ehdr.e_phoff = sizeof(ElfW(Ehdr));
2365 }
2366
2367 /* align to 4 */
2368 file_offset = (file_offset + 3) & -4;
2369
2370 /* fill header */
2371 ehdr.e_ident[0] = ELFMAG0;
2372 ehdr.e_ident[1] = ELFMAG1;
2373 ehdr.e_ident[2] = ELFMAG2;
2374 ehdr.e_ident[3] = ELFMAG3;
2375 ehdr.e_ident[4] = ELFCLASSW;
2376 ehdr.e_ident[5] = ELFDATA2LSB;
2377 ehdr.e_ident[6] = EV_CURRENT;
2378 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2379 ehdr.e_ident[EI_OSABI] = ELFOSABI_FREEBSD;
2380 #endif
2381 #ifdef TCC_TARGET_ARM
2382 #ifdef TCC_ARM_EABI
2383 ehdr.e_ident[EI_OSABI] = 0;
2384 ehdr.e_flags = EF_ARM_EABI_VER4;
2385 if (file_type == TCC_OUTPUT_EXE || file_type == TCC_OUTPUT_DLL)
2386 ehdr.e_flags |= EF_ARM_HASENTRY;
2387 if (s1->float_abi == ARM_HARD_FLOAT)
2388 ehdr.e_flags |= EF_ARM_VFP_FLOAT;
2389 else
2390 ehdr.e_flags |= EF_ARM_SOFT_FLOAT;
2391 #else
2392 ehdr.e_ident[EI_OSABI] = ELFOSABI_ARM;
2393 #endif
2394 #endif
2395 switch(file_type) {
2396 default:
2397 case TCC_OUTPUT_EXE:
2398 ehdr.e_type = ET_EXEC;
2399 ehdr.e_entry = get_elf_sym_addr(s1, "_start", 1);
2400 break;
2401 case TCC_OUTPUT_DLL:
2402 ehdr.e_type = ET_DYN;
2403 ehdr.e_entry = text_section->sh_addr; /* XXX: is it correct ? */
2404 break;
2405 case TCC_OUTPUT_OBJ:
2406 ehdr.e_type = ET_REL;
2407 break;
2408 }
2409 ehdr.e_machine = EM_TCC_TARGET;
2410 ehdr.e_version = EV_CURRENT;
2411 ehdr.e_shoff = file_offset;
2412 ehdr.e_ehsize = sizeof(ElfW(Ehdr));
2413 ehdr.e_shentsize = sizeof(ElfW(Shdr));
2414 ehdr.e_shnum = shnum;
2415 ehdr.e_shstrndx = shnum - 1;
2416
2417 fwrite(&ehdr, 1, sizeof(ElfW(Ehdr)), f);
2418 fwrite(phdr, 1, phnum * sizeof(ElfW(Phdr)), f);
2419 offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr));
2420
2421 sort_syms(s1, symtab_section);
2422 for(i = 1; i < s1->nb_sections; i++) {
2423 s = s1->sections[sec_order[i]];
2424 if (s->sh_type != SHT_NOBITS) {
2425 if (s->sh_type == SHT_DYNSYM)
2426 patch_dynsym_undef(s1, s);
2427 while (offset < s->sh_offset) {
2428 fputc(0, f);
2429 offset++;
2430 }
2431 size = s->sh_size;
2432 fwrite(s->data, 1, size, f);
2433 offset += size;
2434 }
2435 }
2436
2437 /* output section headers */
2438 while (offset < ehdr.e_shoff) {
2439 fputc(0, f);
2440 offset++;
2441 }
2442
2443 for(i = 0; i < s1->nb_sections; i++) {
2444 sh = &shdr;
2445 memset(sh, 0, sizeof(ElfW(Shdr)));
2446 s = s1->sections[i];
2447 if (s) {
2448 sh->sh_name = s->sh_name;
2449 sh->sh_type = s->sh_type;
2450 sh->sh_flags = s->sh_flags;
2451 sh->sh_entsize = s->sh_entsize;
2452 sh->sh_info = s->sh_info;
2453 if (s->link)
2454 sh->sh_link = s->link->sh_num;
2455 sh->sh_addralign = s->sh_addralign;
2456 sh->sh_addr = s->sh_addr;
2457 sh->sh_offset = s->sh_offset;
2458 sh->sh_size = s->sh_size;
2459 }
2460 fwrite(sh, 1, sizeof(ElfW(Shdr)), f);
2461 }
2462 }
2463
2464 /* Write an elf, coff or "binary" file */
2465 static int tcc_write_elf_file(TCCState *s1, const char *filename, int phnum,
2466 ElfW(Phdr) *phdr, int file_offset, int *sec_order)
2467 {
2468 int fd, mode, file_type;
2469 FILE *f;
2470
2471 file_type = s1->output_type;
2472 if (file_type == TCC_OUTPUT_OBJ)
2473 mode = 0666;
2474 else
2475 mode = 0777;
2476 unlink(filename);
2477 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, mode);
2478 if (fd < 0) {
2479 tcc_error_noabort("could not write '%s'", filename);
2480 return -1;
2481 }
2482 f = fdopen(fd, "wb");
2483 if (s1->verbose)
2484 printf("<- %s\n", filename);
2485
2486 #ifdef TCC_TARGET_COFF
2487 if (s1->output_format == TCC_OUTPUT_FORMAT_COFF)
2488 tcc_output_coff(s1, f);
2489 else
2490 #endif
2491 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF)
2492 tcc_output_elf(s1, f, phnum, phdr, file_offset, sec_order);
2493 else
2494 tcc_output_binary(s1, f, sec_order);
2495 fclose(f);
2496
2497 return 0;
2498 }
2499
2500 /* Output an elf, coff or binary file */
2501 /* XXX: suppress unneeded sections */
2502 static int elf_output_file(TCCState *s1, const char *filename)
2503 {
2504 int i, ret, phnum, shnum, file_type, file_offset, *sec_order;
2505 struct dyn_inf dyninf;
2506 ElfW(Phdr) *phdr;
2507 ElfW(Sym) *sym;
2508 Section *strsec, *interp, *dynamic, *dynstr;
2509
2510 file_type = s1->output_type;
2511 s1->nb_errors = 0;
2512
2513 /* if linking, also link in runtime libraries (libc, libgcc, etc.) */
2514 if (file_type != TCC_OUTPUT_OBJ) {
2515 tcc_add_runtime(s1);
2516 }
2517
2518 phdr = NULL;
2519 sec_order = NULL;
2520 interp = dynamic = dynstr = NULL; /* avoid warning */
2521 dyninf.dyn_rel_off = 0; /* avoid warning */
2522
2523 if (file_type != TCC_OUTPUT_OBJ) {
2524 relocate_common_syms();
2525
2526 tcc_add_linker_symbols(s1);
2527
2528 if (!s1->static_link) {
2529 if (file_type == TCC_OUTPUT_EXE) {
2530 char *ptr;
2531 /* allow override the dynamic loader */
2532 const char *elfint = getenv("LD_SO");
2533 if (elfint == NULL)
2534 elfint = DEFAULT_ELFINTERP(s1);
2535 /* add interpreter section only if executable */
2536 interp = new_section(s1, ".interp", SHT_PROGBITS, SHF_ALLOC);
2537 interp->sh_addralign = 1;
2538 ptr = section_ptr_add(interp, 1 + strlen(elfint));
2539 strcpy(ptr, elfint);
2540 }
2541
2542 /* add dynamic symbol table */
2543 s1->dynsym = new_symtab(s1, ".dynsym", SHT_DYNSYM, SHF_ALLOC,
2544 ".dynstr",
2545 ".hash", SHF_ALLOC);
2546 dynstr = s1->dynsym->link;
2547
2548 /* add dynamic section */
2549 dynamic = new_section(s1, ".dynamic", SHT_DYNAMIC,
2550 SHF_ALLOC | SHF_WRITE);
2551 dynamic->link = dynstr;
2552 dynamic->sh_entsize = sizeof(ElfW(Dyn));
2553
2554 build_got(s1);
2555
2556 if (file_type == TCC_OUTPUT_EXE) {
2557 bind_exe_dynsyms(s1);
2558
2559 if (s1->nb_errors) {
2560 ret = -1;
2561 goto the_end;
2562 }
2563
2564 bind_libs_dynsyms(s1);
2565 } else /* shared library case: simply export all global symbols */
2566 export_global_syms(s1);
2567
2568 build_got_entries(s1);
2569
2570 /* add a list of needed dlls */
2571 for(i = 0; i < s1->nb_loaded_dlls; i++) {
2572 DLLReference *dllref = s1->loaded_dlls[i];
2573 if (dllref->level == 0)
2574 put_dt(dynamic, DT_NEEDED, put_elf_str(dynstr, dllref->name));
2575 }
2576
2577 if (s1->rpath)
2578 put_dt(dynamic, DT_RPATH, put_elf_str(dynstr, s1->rpath));
2579
2580 /* XXX: currently, since we do not handle PIC code, we
2581 must relocate the readonly segments */
2582 if (file_type == TCC_OUTPUT_DLL) {
2583 if (s1->soname)
2584 put_dt(dynamic, DT_SONAME, put_elf_str(dynstr, s1->soname));
2585 put_dt(dynamic, DT_TEXTREL, 0);
2586 }
2587
2588 if (s1->symbolic)
2589 put_dt(dynamic, DT_SYMBOLIC, 0);
2590
2591 /* add necessary space for other entries */
2592 dyninf.dyn_rel_off = dynamic->data_offset;
2593 dynamic->data_offset += sizeof(ElfW(Dyn)) * EXTRA_RELITEMS;
2594 } else {
2595 /* still need to build got entries in case of static link */
2596 build_got_entries(s1);
2597 }
2598 }
2599
2600 /* we add a section for symbols */
2601 strsec = new_section(s1, ".shstrtab", SHT_STRTAB, 0);
2602 put_elf_str(strsec, "");
2603
2604 /* compute number of sections */
2605 shnum = s1->nb_sections;
2606
2607 /* this array is used to reorder sections in the output file */
2608 sec_order = tcc_malloc(sizeof(int) * shnum);
2609 sec_order[0] = 0;
2610
2611 /* compute number of program headers */
2612 switch(file_type) {
2613 default:
2614 case TCC_OUTPUT_OBJ:
2615 phnum = 0;
2616 break;
2617 case TCC_OUTPUT_EXE:
2618 if (!s1->static_link)
2619 phnum = 4 + HAVE_PHDR;
2620 else
2621 phnum = 2;
2622 break;
2623 case TCC_OUTPUT_DLL:
2624 phnum = 3;
2625 break;
2626 }
2627
2628 /* Allocate strings for section names */
2629 alloc_sec_names(s1, file_type, strsec);
2630
2631 /* allocate program segment headers */
2632 phdr = tcc_mallocz(phnum * sizeof(ElfW(Phdr)));
2633
2634 /* compute section to program header mapping */
2635 file_offset = layout_sections(s1, phdr, phnum, interp, strsec, &dyninf,
2636 sec_order);
2637
2638 /* Fill remaining program header and finalize relocation related to dynamic
2639 linking. */
2640 if (phnum > 0) {
2641 fill_unloadable_phdr(phdr, phnum, interp, dynamic);
2642 if (dynamic) {
2643 dyninf.dynamic = dynamic;
2644 dyninf.dynstr = dynstr;
2645
2646 fill_dynamic(s1, &dyninf);
2647
2648 /* put in GOT the dynamic section address and relocate PLT */
2649 put32(s1->got->data, dynamic->sh_addr);
2650 if (file_type == TCC_OUTPUT_EXE
2651 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
2652 || file_type == TCC_OUTPUT_DLL
2653 #endif
2654 )
2655 relocate_plt(s1);
2656
2657 /* relocate symbols in .dynsym now that final addresses are known */
2658 for_each_elem(s1->dynsym, 1, sym, ElfW(Sym)) {
2659 if (sym->st_shndx == SHN_UNDEF) {
2660 /* relocate to PLT if symbol corresponds to a PLT entry,
2661 but not if it's a weak symbol */
2662 if (ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
2663 sym->st_value = 0;
2664 else if (sym->st_value)
2665 sym->st_value += s1->plt->sh_addr;
2666 } else if (sym->st_shndx < SHN_LORESERVE) {
2667 /* do symbol relocation */
2668 sym->st_value += s1->sections[sym->st_shndx]->sh_addr;
2669 }
2670 }
2671 }
2672 }
2673
2674 /* if building executable or DLL, then relocate each section
2675 except the GOT which is already relocated */
2676 if (file_type != TCC_OUTPUT_OBJ) {
2677 ret = final_sections_reloc(s1);
2678 if (ret)
2679 goto the_end;
2680 }
2681
2682 /* Perform relocation to GOT or PLT entries */
2683 if (file_type == TCC_OUTPUT_EXE && s1->static_link)
2684 fill_got(s1);
2685
2686 /* Create the ELF file with name 'filename' */
2687 ret = tcc_write_elf_file(s1, filename, phnum, phdr, file_offset, sec_order);
2688 the_end:
2689 tcc_free(s1->symtab_to_dynsym);
2690 tcc_free(sec_order);
2691 tcc_free(phdr);
2692 tcc_free(s1->sym_attrs);
2693 s1->sym_attrs = NULL;
2694 return ret;
2695 }
2696
2697 LIBTCCAPI int tcc_output_file(TCCState *s, const char *filename)
2698 {
2699 int ret;
2700 #ifdef TCC_TARGET_PE
2701 if (s->output_type != TCC_OUTPUT_OBJ) {
2702 ret = pe_output_file(s, filename);
2703 } else
2704 #endif
2705 ret = elf_output_file(s, filename);
2706 return ret;
2707 }
2708
2709 static void *load_data(int fd, unsigned long file_offset, unsigned long size)
2710 {
2711 void *data;
2712
2713 data = tcc_malloc(size);
2714 lseek(fd, file_offset, SEEK_SET);
2715 read(fd, data, size);
2716 return data;
2717 }
2718
2719 typedef struct SectionMergeInfo {
2720 Section *s; /* corresponding existing section */
2721 unsigned long offset; /* offset of the new section in the existing section */
2722 uint8_t new_section; /* true if section 's' was added */
2723 uint8_t link_once; /* true if link once section */
2724 } SectionMergeInfo;
2725
2726 /* load an object file and merge it with current files */
2727 /* XXX: handle correctly stab (debug) info */
2728 ST_FUNC int tcc_load_object_file(TCCState *s1,
2729 int fd, unsigned long file_offset)
2730 {
2731 ElfW(Ehdr) ehdr;
2732 ElfW(Shdr) *shdr, *sh;
2733 int size, i, j, offset, offseti, nb_syms, sym_index, ret;
2734 unsigned char *strsec, *strtab;
2735 int *old_to_new_syms;
2736 char *sh_name, *name;
2737 SectionMergeInfo *sm_table, *sm;
2738 ElfW(Sym) *sym, *symtab;
2739 ElfW_Rel *rel;
2740 Section *s;
2741
2742 int stab_index;
2743 int stabstr_index;
2744
2745 stab_index = stabstr_index = 0;
2746
2747 if (read(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr))
2748 goto fail1;
2749 if (ehdr.e_ident[0] != ELFMAG0 ||
2750 ehdr.e_ident[1] != ELFMAG1 ||
2751 ehdr.e_ident[2] != ELFMAG2 ||
2752 ehdr.e_ident[3] != ELFMAG3)
2753 goto fail1;
2754 /* test if object file */
2755 if (ehdr.e_type != ET_REL)
2756 goto fail1;
2757 /* test CPU specific stuff */
2758 if (ehdr.e_ident[5] != ELFDATA2LSB ||
2759 ehdr.e_machine != EM_TCC_TARGET) {
2760 fail1:
2761 tcc_error_noabort("invalid object file");
2762 return -1;
2763 }
2764 /* read sections */
2765 shdr = load_data(fd, file_offset + ehdr.e_shoff,
2766 sizeof(ElfW(Shdr)) * ehdr.e_shnum);
2767 sm_table = tcc_mallocz(sizeof(SectionMergeInfo) * ehdr.e_shnum);
2768
2769 /* load section names */
2770 sh = &shdr[ehdr.e_shstrndx];
2771 strsec = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2772
2773 /* load symtab and strtab */
2774 old_to_new_syms = NULL;
2775 symtab = NULL;
2776 strtab = NULL;
2777 nb_syms = 0;
2778 for(i = 1; i < ehdr.e_shnum; i++) {
2779 sh = &shdr[i];
2780 if (sh->sh_type == SHT_SYMTAB) {
2781 if (symtab) {
2782 tcc_error_noabort("object must contain only one symtab");
2783 fail:
2784 ret = -1;
2785 goto the_end;
2786 }
2787 nb_syms = sh->sh_size / sizeof(ElfW(Sym));
2788 symtab = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2789 sm_table[i].s = symtab_section;
2790
2791 /* now load strtab */
2792 sh = &shdr[sh->sh_link];
2793 strtab = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2794 }
2795 }
2796
2797 /* now examine each section and try to merge its content with the
2798 ones in memory */
2799 for(i = 1; i < ehdr.e_shnum; i++) {
2800 /* no need to examine section name strtab */
2801 if (i == ehdr.e_shstrndx)
2802 continue;
2803 sh = &shdr[i];
2804 sh_name = (char *) strsec + sh->sh_name;
2805 /* ignore sections types we do not handle */
2806 if (sh->sh_type != SHT_PROGBITS &&
2807 sh->sh_type != SHT_RELX &&
2808 #ifdef TCC_ARM_EABI
2809 sh->sh_type != SHT_ARM_EXIDX &&
2810 #endif
2811 sh->sh_type != SHT_NOBITS &&
2812 sh->sh_type != SHT_PREINIT_ARRAY &&
2813 sh->sh_type != SHT_INIT_ARRAY &&
2814 sh->sh_type != SHT_FINI_ARRAY &&
2815 strcmp(sh_name, ".stabstr")
2816 )
2817 continue;
2818 if (sh->sh_addralign < 1)
2819 sh->sh_addralign = 1;
2820 /* find corresponding section, if any */
2821 for(j = 1; j < s1->nb_sections;j++) {
2822 s = s1->sections[j];
2823 if (!strcmp(s->name, sh_name)) {
2824 if (!strncmp(sh_name, ".gnu.linkonce",
2825 sizeof(".gnu.linkonce") - 1)) {
2826 /* if a 'linkonce' section is already present, we
2827 do not add it again. It is a little tricky as
2828 symbols can still be defined in
2829 it. */
2830 sm_table[i].link_once = 1;
2831 goto next;
2832 } else {
2833 goto found;
2834 }
2835 }
2836 }
2837 /* not found: create new section */
2838 s = new_section(s1, sh_name, sh->sh_type, sh->sh_flags);
2839 /* take as much info as possible from the section. sh_link and
2840 sh_info will be updated later */
2841 s->sh_addralign = sh->sh_addralign;
2842 s->sh_entsize = sh->sh_entsize;
2843 sm_table[i].new_section = 1;
2844 found:
2845 if (sh->sh_type != s->sh_type) {
2846 tcc_error_noabort("invalid section type");
2847 goto fail;
2848 }
2849
2850 /* align start of section */
2851 offset = s->data_offset;
2852
2853 if (0 == strcmp(sh_name, ".stab")) {
2854 stab_index = i;
2855 goto no_align;
2856 }
2857 if (0 == strcmp(sh_name, ".stabstr")) {
2858 stabstr_index = i;
2859 goto no_align;
2860 }
2861
2862 size = sh->sh_addralign - 1;
2863 offset = (offset + size) & ~size;
2864 if (sh->sh_addralign > s->sh_addralign)
2865 s->sh_addralign = sh->sh_addralign;
2866 s->data_offset = offset;
2867 no_align:
2868 sm_table[i].offset = offset;
2869 sm_table[i].s = s;
2870 /* concatenate sections */
2871 size = sh->sh_size;
2872 if (sh->sh_type != SHT_NOBITS) {
2873 unsigned char *ptr;
2874 lseek(fd, file_offset + sh->sh_offset, SEEK_SET);
2875 ptr = section_ptr_add(s, size);
2876 read(fd, ptr, size);
2877 } else {
2878 s->data_offset += size;
2879 }
2880 next: ;
2881 }
2882
2883 /* gr relocate stab strings */
2884 if (stab_index && stabstr_index) {
2885 Stab_Sym *a, *b;
2886 unsigned o;
2887 s = sm_table[stab_index].s;
2888 a = (Stab_Sym *)(s->data + sm_table[stab_index].offset);
2889 b = (Stab_Sym *)(s->data + s->data_offset);
2890 o = sm_table[stabstr_index].offset;
2891 while (a < b)
2892 a->n_strx += o, a++;
2893 }
2894
2895 /* second short pass to update sh_link and sh_info fields of new
2896 sections */
2897 for(i = 1; i < ehdr.e_shnum; i++) {
2898 s = sm_table[i].s;
2899 if (!s || !sm_table[i].new_section)
2900 continue;
2901 sh = &shdr[i];
2902 if (sh->sh_link > 0)
2903 s->link = sm_table[sh->sh_link].s;
2904 if (sh->sh_type == SHT_RELX) {
2905 s->sh_info = sm_table[sh->sh_info].s->sh_num;
2906 /* update backward link */
2907 s1->sections[s->sh_info]->reloc = s;
2908 }
2909 }
2910 sm = sm_table;
2911
2912 /* resolve symbols */
2913 old_to_new_syms = tcc_mallocz(nb_syms * sizeof(int));
2914
2915 sym = symtab + 1;
2916 for(i = 1; i < nb_syms; i++, sym++) {
2917 if (sym->st_shndx != SHN_UNDEF &&
2918 sym->st_shndx < SHN_LORESERVE) {
2919 sm = &sm_table[sym->st_shndx];
2920 if (sm->link_once) {
2921 /* if a symbol is in a link once section, we use the
2922 already defined symbol. It is very important to get
2923 correct relocations */
2924 if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
2925 name = (char *) strtab + sym->st_name;
2926 sym_index = find_elf_sym(symtab_section, name);
2927 if (sym_index)
2928 old_to_new_syms[i] = sym_index;
2929 }
2930 continue;
2931 }
2932 /* if no corresponding section added, no need to add symbol */
2933 if (!sm->s)
2934 continue;
2935 /* convert section number */
2936 sym->st_shndx = sm->s->sh_num;
2937 /* offset value */
2938 sym->st_value += sm->offset;
2939 }
2940 /* add symbol */
2941 name = (char *) strtab + sym->st_name;
2942 sym_index = add_elf_sym(symtab_section, sym->st_value, sym->st_size,
2943 sym->st_info, sym->st_other,
2944 sym->st_shndx, name);
2945 old_to_new_syms[i] = sym_index;
2946 }
2947
2948 /* third pass to patch relocation entries */
2949 for(i = 1; i < ehdr.e_shnum; i++) {
2950 s = sm_table[i].s;
2951 if (!s)
2952 continue;
2953 sh = &shdr[i];
2954 offset = sm_table[i].offset;
2955 switch(s->sh_type) {
2956 case SHT_RELX:
2957 /* take relocation offset information */
2958 offseti = sm_table[sh->sh_info].offset;
2959 for_each_elem(s, (offset / sizeof(*rel)), rel, ElfW_Rel) {
2960 int type;
2961 unsigned sym_index;
2962 /* convert symbol index */
2963 type = ELFW(R_TYPE)(rel->r_info);
2964 sym_index = ELFW(R_SYM)(rel->r_info);
2965 /* NOTE: only one symtab assumed */
2966 if (sym_index >= nb_syms)
2967 goto invalid_reloc;
2968 sym_index = old_to_new_syms[sym_index];
2969 /* ignore link_once in rel section. */
2970 if (!sym_index && !sm->link_once
2971 #ifdef TCC_TARGET_ARM
2972 && type != R_ARM_V4BX
2973 #endif
2974 ) {
2975 invalid_reloc:
2976 tcc_error_noabort("Invalid relocation entry [%2d] '%s' @ %.8x",
2977 i, strsec + sh->sh_name, rel->r_offset);
2978 goto fail;
2979 }
2980 rel->r_info = ELFW(R_INFO)(sym_index, type);
2981 /* offset the relocation offset */
2982 rel->r_offset += offseti;
2983 #ifdef TCC_TARGET_ARM
2984 /* Jumps and branches from a Thumb code to a PLT entry need
2985 special handling since PLT entries are ARM code.
2986 Unconditional bl instructions referencing PLT entries are
2987 handled by converting these instructions into blx
2988 instructions. Other case of instructions referencing a PLT
2989 entry require to add a Thumb stub before the PLT entry to
2990 switch to ARM mode. We set bit plt_thumb_stub of the
2991 attribute of a symbol to indicate such a case. */
2992 if (type == R_ARM_THM_JUMP24)
2993 alloc_sym_attr(s1, sym_index)->plt_thumb_stub = 1;
2994 #endif
2995 }
2996 break;
2997 default:
2998 break;
2999 }
3000 }
3001
3002 ret = 0;
3003 the_end:
3004 tcc_free(symtab);
3005 tcc_free(strtab);
3006 tcc_free(old_to_new_syms);
3007 tcc_free(sm_table);
3008 tcc_free(strsec);
3009 tcc_free(shdr);
3010 return ret;
3011 }
3012
3013 typedef struct ArchiveHeader {
3014 char ar_name[16]; /* name of this member */
3015 char ar_date[12]; /* file mtime */
3016 char ar_uid[6]; /* owner uid; printed as decimal */
3017 char ar_gid[6]; /* owner gid; printed as decimal */
3018 char ar_mode[8]; /* file mode, printed as octal */
3019 char ar_size[10]; /* file size, printed as decimal */
3020 char ar_fmag[2]; /* should contain ARFMAG */
3021 } ArchiveHeader;
3022
3023 static int get_be32(const uint8_t *b)
3024 {
3025 return b[3] | (b[2] << 8) | (b[1] << 16) | (b[0] << 24);
3026 }
3027
3028 /* load only the objects which resolve undefined symbols */
3029 static int tcc_load_alacarte(TCCState *s1, int fd, int size)
3030 {
3031 int i, bound, nsyms, sym_index, off, ret;
3032 uint8_t *data;
3033 const char *ar_names, *p;
3034 const uint8_t *ar_index;
3035 ElfW(Sym) *sym;
3036
3037 data = tcc_malloc(size);
3038 if (read(fd, data, size) != size)
3039 goto fail;
3040 nsyms = get_be32(data);
3041 ar_index = data + 4;
3042 ar_names = (char *) ar_index + nsyms * 4;
3043
3044 do {
3045 bound = 0;
3046 for(p = ar_names, i = 0; i < nsyms; i++, p += strlen(p)+1) {
3047 sym_index = find_elf_sym(symtab_section, p);
3048 if(sym_index) {
3049 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
3050 if(sym->st_shndx == SHN_UNDEF) {
3051 off = get_be32(ar_index + i * 4) + sizeof(ArchiveHeader);
3052 ++bound;
3053 lseek(fd, off, SEEK_SET);
3054 if(tcc_load_object_file(s1, fd, off) < 0) {
3055 fail:
3056 ret = -1;
3057 goto the_end;
3058 }
3059 }
3060 }
3061 }
3062 } while(bound);
3063 ret = 0;
3064 the_end:
3065 tcc_free(data);
3066 return ret;
3067 }
3068
3069 /* load a '.a' file */
3070 ST_FUNC int tcc_load_archive(TCCState *s1, int fd)
3071 {
3072 ArchiveHeader hdr;
3073 char ar_size[11];
3074 char ar_name[17];
3075 char magic[8];
3076 int size, len, i;
3077 unsigned long file_offset;
3078
3079 /* skip magic which was already checked */
3080 read(fd, magic, sizeof(magic));
3081
3082 for(;;) {
3083 len = read(fd, &hdr, sizeof(hdr));
3084 if (len == 0)
3085 break;
3086 if (len != sizeof(hdr)) {
3087 tcc_error_noabort("invalid archive");
3088 return -1;
3089 }
3090 memcpy(ar_size, hdr.ar_size, sizeof(hdr.ar_size));
3091 ar_size[sizeof(hdr.ar_size)] = '\0';
3092 size = strtol(ar_size, NULL, 0);
3093 memcpy(ar_name, hdr.ar_name, sizeof(hdr.ar_name));
3094 for(i = sizeof(hdr.ar_name) - 1; i >= 0; i--) {
3095 if (ar_name[i] != ' ')
3096 break;
3097 }
3098 ar_name[i + 1] = '\0';
3099 file_offset = lseek(fd, 0, SEEK_CUR);
3100 /* align to even */
3101 size = (size + 1) & ~1;
3102 if (!strcmp(ar_name, "/")) {
3103 /* coff symbol table : we handle it */
3104 if(s1->alacarte_link)
3105 return tcc_load_alacarte(s1, fd, size);
3106 } else if (!strcmp(ar_name, "//") ||
3107 !strcmp(ar_name, "__.SYMDEF") ||
3108 !strcmp(ar_name, "__.SYMDEF/") ||
3109 !strcmp(ar_name, "ARFILENAMES/")) {
3110 /* skip symbol table or archive names */
3111 } else {
3112 if (tcc_load_object_file(s1, fd, file_offset) < 0)
3113 return -1;
3114 }
3115 lseek(fd, file_offset + size, SEEK_SET);
3116 }
3117 return 0;
3118 }
3119
3120 #ifndef TCC_TARGET_PE
3121 /* load a DLL and all referenced DLLs. 'level = 0' means that the DLL
3122 is referenced by the user (so it should be added as DT_NEEDED in
3123 the generated ELF file) */
3124 ST_FUNC int tcc_load_dll(TCCState *s1, int fd, const char *filename, int level)
3125 {
3126 ElfW(Ehdr) ehdr;
3127 ElfW(Shdr) *shdr, *sh, *sh1;
3128 int i, j, nb_syms, nb_dts, sym_bind, ret;
3129 ElfW(Sym) *sym, *dynsym;
3130 ElfW(Dyn) *dt, *dynamic;
3131 unsigned char *dynstr;
3132 const char *name, *soname;
3133 DLLReference *dllref;
3134
3135 read(fd, &ehdr, sizeof(ehdr));
3136
3137 /* test CPU specific stuff */
3138 if (ehdr.e_ident[5] != ELFDATA2LSB ||
3139 ehdr.e_machine != EM_TCC_TARGET) {
3140 tcc_error_noabort("bad architecture");
3141 return -1;
3142 }
3143
3144 /* read sections */
3145 shdr = load_data(fd, ehdr.e_shoff, sizeof(ElfW(Shdr)) * ehdr.e_shnum);
3146
3147 /* load dynamic section and dynamic symbols */
3148 nb_syms = 0;
3149 nb_dts = 0;
3150 dynamic = NULL;
3151 dynsym = NULL; /* avoid warning */
3152 dynstr = NULL; /* avoid warning */
3153 for(i = 0, sh = shdr; i < ehdr.e_shnum; i++, sh++) {
3154 switch(sh->sh_type) {
3155 case SHT_DYNAMIC:
3156 nb_dts = sh->sh_size / sizeof(ElfW(Dyn));
3157 dynamic = load_data(fd, sh->sh_offset, sh->sh_size);
3158 break;
3159 case SHT_DYNSYM:
3160 nb_syms = sh->sh_size / sizeof(ElfW(Sym));
3161 dynsym = load_data(fd, sh->sh_offset, sh->sh_size);
3162 sh1 = &shdr[sh->sh_link];
3163 dynstr = load_data(fd, sh1->sh_offset, sh1->sh_size);
3164 break;
3165 default:
3166 break;
3167 }
3168 }
3169
3170 /* compute the real library name */
3171 soname = tcc_basename(filename);
3172
3173 for(i = 0, dt = dynamic; i < nb_dts; i++, dt++) {
3174 if (dt->d_tag == DT_SONAME) {
3175 soname = (char *) dynstr + dt->d_un.d_val;
3176 }
3177 }
3178
3179 /* if the dll is already loaded, do not load it */
3180 for(i = 0; i < s1->nb_loaded_dlls; i++) {
3181 dllref = s1->loaded_dlls[i];
3182 if (!strcmp(soname, dllref->name)) {
3183 /* but update level if needed */
3184 if (level < dllref->level)
3185 dllref->level = level;
3186 ret = 0;
3187 goto the_end;
3188 }
3189 }
3190
3191 /* add the dll and its level */
3192 dllref = tcc_mallocz(sizeof(DLLReference) + strlen(soname));
3193 dllref->level = level;
3194 strcpy(dllref->name, soname);
3195 dynarray_add((void ***)&s1->loaded_dlls, &s1->nb_loaded_dlls, dllref);
3196
3197 /* add dynamic symbols in dynsym_section */
3198 for(i = 1, sym = dynsym + 1; i < nb_syms; i++, sym++) {
3199 sym_bind = ELFW(ST_BIND)(sym->st_info);
3200 if (sym_bind == STB_LOCAL)
3201 continue;
3202 name = (char *) dynstr + sym->st_name;
3203 add_elf_sym(s1->dynsymtab_section, sym->st_value, sym->st_size,
3204 sym->st_info, sym->st_other, sym->st_shndx, name);
3205 }
3206
3207 /* load all referenced DLLs */
3208 for(i = 0, dt = dynamic; i < nb_dts; i++, dt++) {
3209 switch(dt->d_tag) {
3210 case DT_NEEDED:
3211 name = (char *) dynstr + dt->d_un.d_val;
3212 for(j = 0; j < s1->nb_loaded_dlls; j++) {
3213 dllref = s1->loaded_dlls[j];
3214 if (!strcmp(name, dllref->name))
3215 goto already_loaded;
3216 }
3217 if (tcc_add_dll(s1, name, AFF_REFERENCED_DLL) < 0) {
3218 tcc_error_noabort("referenced dll '%s' not found", name);
3219 ret = -1;
3220 goto the_end;
3221 }
3222 already_loaded:
3223 break;
3224 }
3225 }
3226 ret = 0;
3227 the_end:
3228 tcc_free(dynstr);
3229 tcc_free(dynsym);
3230 tcc_free(dynamic);
3231 tcc_free(shdr);
3232 return ret;
3233 }
3234
3235 #define LD_TOK_NAME 256
3236 #define LD_TOK_EOF (-1)
3237
3238 /* return next ld script token */
3239 static int ld_next(TCCState *s1, char *name, int name_size)
3240 {
3241 int c;
3242 char *q;
3243
3244 redo:
3245 switch(ch) {
3246 case ' ':
3247 case '\t':
3248 case '\f':
3249 case '\v':
3250 case '\r':
3251 case '\n':
3252 inp();
3253 goto redo;
3254 case '/':
3255 minp();
3256 if (ch == '*') {
3257 file->buf_ptr = parse_comment(file->buf_ptr);
3258 ch = file->buf_ptr[0];
3259 goto redo;
3260 } else {
3261 q = name;
3262 *q++ = '/';
3263 goto parse_name;
3264 }
3265 break;
3266 /* case 'a' ... 'z': */
3267 case 'a':
3268 case 'b':
3269 case 'c':
3270 case 'd':
3271 case 'e':
3272 case 'f':
3273 case 'g':
3274 case 'h':
3275 case 'i':
3276 case 'j':
3277 case 'k':
3278 case 'l':
3279 case 'm':
3280 case 'n':
3281 case 'o':
3282 case 'p':
3283 case 'q':
3284 case 'r':
3285 case 's':
3286 case 't':
3287 case 'u':
3288 case 'v':
3289 case 'w':
3290 case 'x':
3291 case 'y':
3292 case 'z':
3293 /* case 'A' ... 'z': */
3294 case 'A':
3295 case 'B':
3296 case 'C':
3297 case 'D':
3298 case 'E':
3299 case 'F':
3300 case 'G':
3301 case 'H':
3302 case 'I':
3303 case 'J':
3304 case 'K':
3305 case 'L':
3306 case 'M':
3307 case 'N':
3308 case 'O':
3309 case 'P':
3310 case 'Q':
3311 case 'R':
3312 case 'S':
3313 case 'T':
3314 case 'U':
3315 case 'V':
3316 case 'W':
3317 case 'X':
3318 case 'Y':
3319 case 'Z':
3320 case '_':
3321 case '\\':
3322 case '.':
3323 case '$':
3324 case '~':
3325 q = name;
3326 parse_name:
3327 for(;;) {
3328 if (!((ch >= 'a' && ch <= 'z') ||
3329 (ch >= 'A' && ch <= 'Z') ||
3330 (ch >= '0' && ch <= '9') ||
3331 strchr("/.-_+=$:\\,~", ch)))
3332 break;
3333 if ((q - name) < name_size - 1) {
3334 *q++ = ch;
3335 }
3336 minp();
3337 }
3338 *q = '\0';
3339 c = LD_TOK_NAME;
3340 break;
3341 case CH_EOF:
3342 c = LD_TOK_EOF;
3343 break;
3344 default:
3345 c = ch;
3346 inp();
3347 break;
3348 }
3349 return c;
3350 }
3351
3352 static int ld_add_file(TCCState *s1, const char filename[])
3353 {
3354 int ret;
3355
3356 ret = tcc_add_file_internal(s1, filename, 0);
3357 if (ret)
3358 ret = tcc_add_dll(s1, filename, 0);
3359 return ret;
3360 }
3361
3362 static inline int new_undef_syms(void)
3363 {
3364 int ret = 0;
3365 ret = new_undef_sym;
3366 new_undef_sym = 0;
3367 return ret;
3368 }
3369
3370 static int ld_add_file_list(TCCState *s1, const char *cmd, int as_needed)
3371 {
3372 char filename[1024], libname[1024];
3373 int t, group, nblibs = 0, ret = 0;
3374 char **libs = NULL;
3375
3376 group = !strcmp(cmd, "GROUP");
3377 if (!as_needed)
3378 new_undef_syms();
3379 t = ld_next(s1, filename, sizeof(filename));
3380 if (t != '(')
3381 expect("(");
3382 t = ld_next(s1, filename, sizeof(filename));
3383 for(;;) {
3384 libname[0] = '\0';
3385 if (t == LD_TOK_EOF) {
3386 tcc_error_noabort("unexpected end of file");
3387 ret = -1;
3388 goto lib_parse_error;
3389 } else if (t == ')') {
3390 break;
3391 } else if (t == '-') {
3392 t = ld_next(s1, filename, sizeof(filename));
3393 if ((t != LD_TOK_NAME) || (filename[0] != 'l')) {
3394 tcc_error_noabort("library name expected");
3395 ret = -1;
3396 goto lib_parse_error;
3397 }
3398 pstrcpy(libname, sizeof libname, &filename[1]);
3399 if (s1->static_link) {
3400 snprintf(filename, sizeof filename, "lib%s.a", libname);
3401 } else {
3402 snprintf(filename, sizeof filename, "lib%s.so", libname);
3403 }
3404 } else if (t != LD_TOK_NAME) {
3405 tcc_error_noabort("filename expected");
3406 ret = -1;
3407 goto lib_parse_error;
3408 }
3409 if (!strcmp(filename, "AS_NEEDED")) {
3410 ret = ld_add_file_list(s1, cmd, 1);
3411 if (ret)
3412 goto lib_parse_error;
3413 } else {
3414 /* TODO: Implement AS_NEEDED support. Ignore it for now */
3415 if (!as_needed) {
3416 ret = ld_add_file(s1, filename);
3417 if (ret)
3418 goto lib_parse_error;
3419 if (group) {
3420 /* Add the filename *and* the libname to avoid future conversions */
3421 dynarray_add((void ***) &libs, &nblibs, tcc_strdup(filename));
3422 if (libname[0] != '\0')
3423 dynarray_add((void ***) &libs, &nblibs, tcc_strdup(libname));
3424 }
3425 }
3426 }
3427 t = ld_next(s1, filename, sizeof(filename));
3428 if (t == ',') {
3429 t = ld_next(s1, filename, sizeof(filename));
3430 }
3431 }
3432 if (group && !as_needed) {
3433 while (new_undef_syms()) {
3434 int i;
3435
3436 for (i = 0; i < nblibs; i ++)
3437 ld_add_file(s1, libs[i]);
3438 }
3439 }
3440 lib_parse_error:
3441 dynarray_reset(&libs, &nblibs);
3442 return ret;
3443 }
3444
3445 /* interpret a subset of GNU ldscripts to handle the dummy libc.so
3446 files */
3447 ST_FUNC int tcc_load_ldscript(TCCState *s1)
3448 {
3449 char cmd[64];
3450 char filename[1024];
3451 int t, ret;
3452
3453 ch = file->buf_ptr[0];
3454 ch = handle_eob();
3455 for(;;) {
3456 t = ld_next(s1, cmd, sizeof(cmd));
3457 if (t == LD_TOK_EOF)
3458 return 0;
3459 else if (t != LD_TOK_NAME)
3460 return -1;
3461 if (!strcmp(cmd, "INPUT") ||
3462 !strcmp(cmd, "GROUP")) {
3463 ret = ld_add_file_list(s1, cmd, 0);
3464 if (ret)
3465 return ret;
3466 } else if (!strcmp(cmd, "OUTPUT_FORMAT") ||
3467 !strcmp(cmd, "TARGET")) {
3468 /* ignore some commands */
3469 t = ld_next(s1, cmd, sizeof(cmd));
3470 if (t != '(')
3471 expect("(");
3472 for(;;) {
3473 t = ld_next(s1, filename, sizeof(filename));
3474 if (t == LD_TOK_EOF) {
3475 tcc_error_noabort("unexpected end of file");
3476 return -1;
3477 } else if (t == ')') {
3478 break;
3479 }
3480 }
3481 } else {
3482 return -1;
3483 }
3484 }
3485 return 0;
3486 }
3487 #endif /* !TCC_TARGET_PE */
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