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quick fix for the native tcc on debian/ubuntu
[tinycc.git] / tccelf.c
blobae4e2db1a6841461ac1fae34b2851a87a9808a99
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, unsigned long 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 <= -2147483647 || diff > 2147483647) {
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 ST_FUNC void tcc_add_bcheck(TCCState *s1)
1544 {
1545 #ifdef CONFIG_TCC_BCHECK
1546 unsigned long *ptr;
1547 Section *init_section;
1548 unsigned char *pinit;
1549 int sym_index;
1550
1551 if (0 == s1->do_bounds_check)
1552 return;
1553
1554 /* XXX: add an object file to do that */
1555 ptr = section_ptr_add(bounds_section, sizeof(unsigned long));
1556 *ptr = 0;
1557 add_elf_sym(symtab_section, 0, 0,
1558 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1559 bounds_section->sh_num, "__bounds_start");
1560 #ifdef TCC_TARGET_I386
1561 if (s1->output_type != TCC_OUTPUT_MEMORY) {
1562 /* add 'call __bound_init()' in .init section */
1563 init_section = find_section(s1, ".init");
1564 pinit = section_ptr_add(init_section, 5);
1565 pinit[0] = 0xe8;
1566 put32(pinit + 1, -4);
1567 sym_index = find_elf_sym(symtab_section, "__bound_init");
1568 put_elf_reloc(symtab_section, init_section,
1569 init_section->data_offset - 4, R_386_PC32, sym_index);
1570 }
1571 #endif
1572 #endif
1573 }
1574
1575 static inline int tcc_add_support(TCCState *s1, const char *filename)
1576 {
1577 char buf[1024];
1578 snprintf(buf, sizeof(buf), "%s/%s/%s", s1->tcc_lib_path,
1579 /* an cpu specific path inside tcc_lib_path, mainly for keeping libtcc1.a */
1580 #ifdef TCC_TARGET_I386
1581 "i386"
1582 #endif
1583 #ifdef TCC_TARGET_X86_64
1584 "x86-64"
1585 #endif
1586 #ifdef TCC_TARGET_ARM
1587 "arm"
1588 #endif
1589 #ifdef TCC_TARGET_ARM64
1590 "arm64"
1591 #endif
1592 #ifdef TCC_TARGET_C67
1593 "C67"
1594 #endif
1595 ,filename);
1596
1597 return tcc_add_file(s1, buf);
1598 }
1599
1600 /* add tcc runtime libraries */
1601 ST_FUNC void tcc_add_runtime(TCCState *s1)
1602 {
1603 /* add libc */
1604 if (!s1->nostdlib) {
1605 tcc_add_library(s1, "c");
1606 #ifdef CONFIG_USE_LIBGCC
1607 if (!s1->static_link) {
1608 tcc_add_file(s1, TCC_LIBGCC);
1609 }
1610 #endif
1611 tcc_add_support(s1, "libtcc1.a");
1612 }
1613
1614 /* tcc_add_bcheck tries to relocate a call to __bound_init in _init so
1615 libtcc1.a must be loaded before for __bound_init to be defined and
1616 crtn.o must be loaded after to not finalize _init too early. */
1617 tcc_add_bcheck(s1);
1618
1619 if (!s1->nostdlib) {
1620 /* add crt end if not memory output */
1621 if (s1->output_type != TCC_OUTPUT_MEMORY)
1622 tcc_add_crt(s1, "crtn.o");
1623 }
1624 }
1625
1626 /* add various standard linker symbols (must be done after the
1627 sections are filled (for example after allocating common
1628 symbols)) */
1629 ST_FUNC void tcc_add_linker_symbols(TCCState *s1)
1630 {
1631 char buf[1024];
1632 int i;
1633 Section *s;
1634
1635 add_elf_sym(symtab_section,
1636 text_section->data_offset, 0,
1637 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1638 text_section->sh_num, "_etext");
1639 add_elf_sym(symtab_section,
1640 data_section->data_offset, 0,
1641 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1642 data_section->sh_num, "_edata");
1643 add_elf_sym(symtab_section,
1644 bss_section->data_offset, 0,
1645 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1646 bss_section->sh_num, "_end");
1647 /* horrible new standard ldscript defines */
1648 add_init_array_defines(s1, ".preinit_array");
1649 add_init_array_defines(s1, ".init_array");
1650 add_init_array_defines(s1, ".fini_array");
1651
1652 /* add start and stop symbols for sections whose name can be
1653 expressed in C */
1654 for(i = 1; i < s1->nb_sections; i++) {
1655 s = s1->sections[i];
1656 if (s->sh_type == SHT_PROGBITS &&
1657 (s->sh_flags & SHF_ALLOC)) {
1658 const char *p;
1659 int ch;
1660
1661 /* check if section name can be expressed in C */
1662 p = s->name;
1663 for(;;) {
1664 ch = *p;
1665 if (!ch)
1666 break;
1667 if (!isid(ch) && !isnum(ch))
1668 goto next_sec;
1669 p++;
1670 }
1671 snprintf(buf, sizeof(buf), "__start_%s", s->name);
1672 add_elf_sym(symtab_section,
1673 0, 0,
1674 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1675 s->sh_num, buf);
1676 snprintf(buf, sizeof(buf), "__stop_%s", s->name);
1677 add_elf_sym(symtab_section,
1678 s->data_offset, 0,
1679 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1680 s->sh_num, buf);
1681 }
1682 next_sec: ;
1683 }
1684 }
1685
1686 static void tcc_output_binary(TCCState *s1, FILE *f,
1687 const int *sec_order)
1688 {
1689 Section *s;
1690 int i, offset, size;
1691
1692 offset = 0;
1693 for(i=1;i<s1->nb_sections;i++) {
1694 s = s1->sections[sec_order[i]];
1695 if (s->sh_type != SHT_NOBITS &&
1696 (s->sh_flags & SHF_ALLOC)) {
1697 while (offset < s->sh_offset) {
1698 fputc(0, f);
1699 offset++;
1700 }
1701 size = s->sh_size;
1702 fwrite(s->data, 1, size, f);
1703 offset += size;
1704 }
1705 }
1706 }
1707
1708 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1709 #define HAVE_PHDR 1
1710 #define EXTRA_RELITEMS 14
1711
1712 /* move the relocation value from .dynsym to .got */
1713 void patch_dynsym_undef(TCCState *s1, Section *s)
1714 {
1715 uint32_t *gotd = (void *)s1->got->data;
1716 ElfW(Sym) *sym;
1717
1718 gotd += 3; /* dummy entries in .got */
1719 /* relocate symbols in .dynsym */
1720 for_each_elem(s, 1, sym, ElfW(Sym)) {
1721 if (sym->st_shndx == SHN_UNDEF) {
1722 *gotd++ = sym->st_value + 6; /* XXX 6 is magic ? */
1723 sym->st_value = 0;
1724 }
1725 }
1726 }
1727 #else
1728 #define HAVE_PHDR 1
1729 #define EXTRA_RELITEMS 9
1730
1731 /* zero plt offsets of weak symbols in .dynsym */
1732 void patch_dynsym_undef(TCCState *s1, Section *s)
1733 {
1734 ElfW(Sym) *sym;
1735
1736 for_each_elem(s, 1, sym, ElfW(Sym))
1737 if (sym->st_shndx == SHN_UNDEF && ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
1738 sym->st_value = 0;
1739 }
1740 #endif
1741
1742 ST_FUNC void fill_got_entry(TCCState *s1, ElfW_Rel *rel)
1743 {
1744 int sym_index = ELFW(R_SYM) (rel->r_info);
1745 ElfW(Sym) *sym = &((ElfW(Sym) *) symtab_section->data)[sym_index];
1746 unsigned long offset;
1747
1748 if (sym_index >= s1->nb_sym_attrs)
1749 return;
1750 offset = s1->sym_attrs[sym_index].got_offset;
1751 section_reserve(s1->got, offset + PTR_SIZE);
1752 #ifdef TCC_TARGET_X86_64
1753 /* only works for x86-64 */
1754 put32(s1->got->data + offset + 4, sym->st_value >> 32);
1755 #endif
1756 put32(s1->got->data + offset, sym->st_value & 0xffffffff);
1757 }
1758
1759 /* Perform relocation to GOT or PLT entries */
1760 ST_FUNC void fill_got(TCCState *s1)
1761 {
1762 Section *s;
1763 ElfW_Rel *rel;
1764 int i;
1765
1766 for(i = 1; i < s1->nb_sections; i++) {
1767 s = s1->sections[i];
1768 if (s->sh_type != SHT_RELX)
1769 continue;
1770 /* no need to handle got relocations */
1771 if (s->link != symtab_section)
1772 continue;
1773 for_each_elem(s, 0, rel, ElfW_Rel) {
1774 switch (ELFW(R_TYPE) (rel->r_info)) {
1775 case R_X86_64_GOT32:
1776 case R_X86_64_GOTPCREL:
1777 case R_X86_64_PLT32:
1778 fill_got_entry(s1, rel);
1779 break;
1780 }
1781 }
1782 }
1783 }
1784
1785 /* Bind symbols of executable: resolve undefined symbols from exported symbols
1786 in shared libraries and export non local defined symbols to shared libraries
1787 if -rdynamic switch was given on command line */
1788 static void bind_exe_dynsyms(TCCState *s1)
1789 {
1790 const char *name;
1791 int sym_index, index;
1792 ElfW(Sym) *sym, *esym;
1793 int type;
1794
1795 /* Resolve undefined symbols from dynamic symbols. When there is a match:
1796 - if STT_FUNC or STT_GNU_IFUNC symbol -> add it in PLT
1797 - if STT_OBJECT symbol -> add it in .bss section with suitable reloc */
1798 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
1799 if (sym->st_shndx == SHN_UNDEF) {
1800 name = (char *) symtab_section->link->data + sym->st_name;
1801 sym_index = find_elf_sym(s1->dynsymtab_section, name);
1802 if (sym_index) {
1803 esym = &((ElfW(Sym) *)s1->dynsymtab_section->data)[sym_index];
1804 type = ELFW(ST_TYPE)(esym->st_info);
1805 if ((type == STT_FUNC) || (type == STT_GNU_IFUNC)) {
1806 /* Indirect functions shall have STT_FUNC type in executable
1807 * dynsym section. Indeed, a dlsym call following a lazy
1808 * resolution would pick the symbol value from the
1809 * executable dynsym entry which would contain the address
1810 * of the function wanted by the caller of dlsym instead of
1811 * the address of the function that would return that
1812 * address */
1813 put_got_entry(s1, R_JMP_SLOT, esym->st_size,
1814 ELFW(ST_INFO)(STB_GLOBAL,STT_FUNC),
1815 sym - (ElfW(Sym) *)symtab_section->data);
1816 } else if (type == STT_OBJECT) {
1817 unsigned long offset;
1818 ElfW(Sym) *dynsym;
1819 offset = bss_section->data_offset;
1820 /* XXX: which alignment ? */
1821 offset = (offset + 16 - 1) & -16;
1822 index = put_elf_sym(s1->dynsym, offset, esym->st_size,
1823 esym->st_info, 0, bss_section->sh_num,
1824 name);
1825 /* Ensure R_COPY works for weak symbol aliases */
1826 if (ELFW(ST_BIND)(esym->st_info) == STB_WEAK) {
1827 for_each_elem(s1->dynsymtab_section, 1, dynsym, ElfW(Sym)) {
1828 if ((dynsym->st_value == esym->st_value)
1829 && (ELFW(ST_BIND)(dynsym->st_info) == STB_GLOBAL)) {
1830 char *dynname = (char *) s1->dynsymtab_section->link->data
1831 + dynsym->st_name;
1832 put_elf_sym(s1->dynsym, offset, dynsym->st_size,
1833 dynsym->st_info, 0,
1834 bss_section->sh_num, dynname);
1835 break;
1836 }
1837 }
1838 }
1839 put_elf_reloc(s1->dynsym, bss_section,
1840 offset, R_COPY, index);
1841 offset += esym->st_size;
1842 bss_section->data_offset = offset;
1843 }
1844 } else {
1845 /* STB_WEAK undefined symbols are accepted */
1846 /* XXX: _fp_hw seems to be part of the ABI, so we ignore it */
1847 if (ELFW(ST_BIND)(sym->st_info) == STB_WEAK ||
1848 !strcmp(name, "_fp_hw")) {
1849 } else {
1850 tcc_error_noabort("undefined symbol '%s'", name);
1851 }
1852 }
1853 } else if (s1->rdynamic && ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
1854 /* if -rdynamic option, then export all non local symbols */
1855 name = (char *) symtab_section->link->data + sym->st_name;
1856 put_elf_sym(s1->dynsym, sym->st_value, sym->st_size, sym->st_info,
1857 0, sym->st_shndx, name);
1858 }
1859 }
1860 }
1861
1862 /* Bind symbols of libraries: export non local symbols of executable that
1863 resolve undefined symbols of shared libraries */
1864 static void bind_libs_dynsyms(TCCState *s1)
1865 {
1866 const char *name;
1867 int sym_index;
1868 ElfW(Sym) *sym, *esym;
1869
1870 /* now look at unresolved dynamic symbols and export
1871 corresponding symbol */
1872 for_each_elem(s1->dynsymtab_section, 1, esym, ElfW(Sym)) {
1873 if (esym->st_shndx == SHN_UNDEF) {
1874 name = (char *) s1->dynsymtab_section->link->data + esym->st_name;
1875 sym_index = find_elf_sym(symtab_section, name);
1876 if (sym_index) {
1877 /* XXX: avoid adding a symbol if already present because of
1878 -rdynamic ? */
1879 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1880 put_elf_sym(s1->dynsym, sym->st_value, sym->st_size,
1881 sym->st_info, 0, sym->st_shndx, name);
1882 } else {
1883 /* weak symbols can stay undefined */
1884 if (ELFW(ST_BIND)(esym->st_info) != STB_WEAK)
1885 tcc_warning("undefined dynamic symbol '%s'", name);
1886 }
1887 }
1888 }
1889 }
1890
1891 /* Export all non local symbols (for shared libraries) */
1892 static void export_global_syms(TCCState *s1)
1893 {
1894 int nb_syms, dynindex, index;
1895 const char *name;
1896 ElfW(Sym) *sym;
1897
1898 nb_syms = symtab_section->data_offset / sizeof(ElfW(Sym));
1899 s1->symtab_to_dynsym = tcc_mallocz(sizeof(int) * nb_syms);
1900 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
1901 if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
1902 name = (char *) symtab_section->link->data + sym->st_name;
1903 dynindex = put_elf_sym(s1->dynsym, sym->st_value, sym->st_size,
1904 sym->st_info, 0, sym->st_shndx, name);
1905 index = sym - (ElfW(Sym) *) symtab_section->data;
1906 s1->symtab_to_dynsym[index] = dynindex;
1907 }
1908 }
1909 }
1910
1911 /* relocate the PLT: compute addresses and offsets in the PLT now that final
1912 address for PLT and GOT are known (see fill_program_header) */
1913 ST_FUNC void relocate_plt(TCCState *s1)
1914 {
1915 uint8_t *p, *p_end;
1916
1917 if (!s1->plt)
1918 return;
1919
1920 p = s1->plt->data;
1921 p_end = p + s1->plt->data_offset;
1922 if (p < p_end) {
1923 #if defined(TCC_TARGET_I386)
1924 put32(p + 2, get32(p + 2) + s1->got->sh_addr);
1925 put32(p + 8, get32(p + 8) + s1->got->sh_addr);
1926 p += 16;
1927 while (p < p_end) {
1928 put32(p + 2, get32(p + 2) + s1->got->sh_addr);
1929 p += 16;
1930 }
1931 #elif defined(TCC_TARGET_X86_64)
1932 int x = s1->got->sh_addr - s1->plt->sh_addr - 6;
1933 put32(p + 2, get32(p + 2) + x);
1934 put32(p + 8, get32(p + 8) + x - 6);
1935 p += 16;
1936 while (p < p_end) {
1937 put32(p + 2, get32(p + 2) + x + s1->plt->data - p);
1938 p += 16;
1939 }
1940 #elif defined(TCC_TARGET_ARM)
1941 int x;
1942 x=s1->got->sh_addr - s1->plt->sh_addr - 12;
1943 p += 16;
1944 while (p < p_end) {
1945 if (get32(p) == 0x46c04778) /* PLT Thumb stub present */
1946 p += 4;
1947 put32(p + 12, x + get32(p + 12) + s1->plt->data - p);
1948 p += 16;
1949 }
1950 #elif defined(TCC_TARGET_ARM64)
1951 uint64_t plt = s1->plt->sh_addr;
1952 uint64_t got = s1->got->sh_addr;
1953 uint64_t off = (got >> 12) - (plt >> 12);
1954 if ((off + ((uint32_t)1 << 20)) >> 21)
1955 tcc_error("Failed relocating PLT (off=0x%lx, got=0x%lx, plt=0x%lx)", off, got, plt);
1956 put32(p, 0xa9bf7bf0); // stp x16,x30,[sp,#-16]!
1957 put32(p + 4, (0x90000010 | // adrp x16,...
1958 (off & 0x1ffffc) << 3 | (off & 3) << 29));
1959 put32(p + 8, (0xf9400211 | // ldr x17,[x16,#...]
1960 (got & 0xff8) << 7));
1961 put32(p + 12, (0x91000210 | // add x16,x16,#...
1962 (got & 0xfff) << 10));
1963 put32(p + 16, 0xd61f0220); // br x17
1964 put32(p + 20, 0xd503201f); // nop
1965 put32(p + 24, 0xd503201f); // nop
1966 put32(p + 28, 0xd503201f); // nop
1967 p += 32;
1968 while (p < p_end) {
1969 uint64_t pc = plt + (p - s1->plt->data);
1970 uint64_t addr = got +
1971 (get32(p) | (uint64_t)get32(p + 4) << 32);
1972 uint32_t off = (addr >> 12) - (pc >> 12);
1973 if ((off + ((uint32_t)1 << 20)) >> 21)
1974 tcc_error("Failed relocating PLT (off=0x%lx, addr=0x%lx, pc=0x%lx)", off, addr, pc);
1975 put32(p, (0x90000010 | // adrp x16,...
1976 (off & 0x1ffffc) << 3 | (off & 3) << 29));
1977 put32(p + 4, (0xf9400211 | // ldr x17,[x16,#...]
1978 (addr & 0xff8) << 7));
1979 put32(p + 8, (0x91000210 | // add x16,x16,#...
1980 (addr & 0xfff) << 10));
1981 put32(p + 12, 0xd61f0220); // br x17
1982 p += 16;
1983 }
1984 #elif defined(TCC_TARGET_C67)
1985 /* XXX: TODO */
1986 #else
1987 #error unsupported CPU
1988 #endif
1989 }
1990 }
1991
1992 /* Allocate strings for section names and decide if an unallocated section
1993 should be output.
1994
1995 NOTE: the strsec section comes last, so its size is also correct ! */
1996 static void alloc_sec_names(TCCState *s1, int file_type, Section *strsec)
1997 {
1998 int i;
1999 Section *s;
2000
2001 /* Allocate strings for section names */
2002 for(i = 1; i < s1->nb_sections; i++) {
2003 s = s1->sections[i];
2004 s->sh_name = put_elf_str(strsec, s->name);
2005 /* when generating a DLL, we include relocations but we may
2006 patch them */
2007 if (file_type == TCC_OUTPUT_DLL &&
2008 s->sh_type == SHT_RELX &&
2009 !(s->sh_flags & SHF_ALLOC)) {
2010 /* gr: avoid bogus relocs for empty (debug) sections */
2011 if (s1->sections[s->sh_info]->sh_flags & SHF_ALLOC)
2012 prepare_dynamic_rel(s1, s);
2013 else if (s1->do_debug)
2014 s->sh_size = s->data_offset;
2015 } else if (s1->do_debug ||
2016 file_type == TCC_OUTPUT_OBJ ||
2017 (s->sh_flags & SHF_ALLOC) ||
2018 i == (s1->nb_sections - 1)) {
2019 /* we output all sections if debug or object file */
2020 s->sh_size = s->data_offset;
2021 }
2022 }
2023 }
2024
2025 /* Info to be copied in dynamic section */
2026 struct dyn_inf {
2027 Section *dynamic;
2028 Section *dynstr;
2029 unsigned long dyn_rel_off;
2030 addr_t rel_addr;
2031 addr_t rel_size;
2032 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2033 addr_t bss_addr;
2034 addr_t bss_size;
2035 #endif
2036 };
2037
2038 /* Assign sections to segments and decide how are sections laid out when loaded
2039 in memory. This function also fills corresponding program headers. */
2040 static int layout_sections(TCCState *s1, ElfW(Phdr) *phdr, int phnum,
2041 Section *interp, Section* strsec,
2042 struct dyn_inf *dyninf, int *sec_order)
2043 {
2044 int i, j, k, file_type, sh_order_index, file_offset;
2045 unsigned long s_align;
2046 long long tmp;
2047 addr_t addr;
2048 ElfW(Phdr) *ph;
2049 Section *s;
2050
2051 file_type = s1->output_type;
2052 sh_order_index = 1;
2053 file_offset = 0;
2054 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF)
2055 file_offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr));
2056 s_align = ELF_PAGE_SIZE;
2057 if (s1->section_align)
2058 s_align = s1->section_align;
2059
2060 if (phnum > 0) {
2061 if (s1->has_text_addr) {
2062 int a_offset, p_offset;
2063 addr = s1->text_addr;
2064 /* we ensure that (addr % ELF_PAGE_SIZE) == file_offset %
2065 ELF_PAGE_SIZE */
2066 a_offset = (int) (addr & (s_align - 1));
2067 p_offset = file_offset & (s_align - 1);
2068 if (a_offset < p_offset)
2069 a_offset += s_align;
2070 file_offset += (a_offset - p_offset);
2071 } else {
2072 if (file_type == TCC_OUTPUT_DLL)
2073 addr = 0;
2074 else
2075 addr = ELF_START_ADDR;
2076 /* compute address after headers */
2077 addr += (file_offset & (s_align - 1));
2078 }
2079
2080 ph = &phdr[0];
2081 /* Leave one program headers for the program interpreter and one for
2082 the program header table itself if needed. These are done later as
2083 they require section layout to be done first. */
2084 if (interp)
2085 ph += 1 + HAVE_PHDR;
2086
2087 /* dynamic relocation table information, for .dynamic section */
2088 dyninf->rel_addr = dyninf->rel_size = 0;
2089 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2090 dyninf->bss_addr = dyninf->bss_size = 0;
2091 #endif
2092
2093 for(j = 0; j < 2; j++) {
2094 ph->p_type = PT_LOAD;
2095 if (j == 0)
2096 ph->p_flags = PF_R | PF_X;
2097 else
2098 ph->p_flags = PF_R | PF_W;
2099 ph->p_align = s_align;
2100
2101 /* Decide the layout of sections loaded in memory. This must
2102 be done before program headers are filled since they contain
2103 info about the layout. We do the following ordering: interp,
2104 symbol tables, relocations, progbits, nobits */
2105 /* XXX: do faster and simpler sorting */
2106 for(k = 0; k < 5; k++) {
2107 for(i = 1; i < s1->nb_sections; i++) {
2108 s = s1->sections[i];
2109 /* compute if section should be included */
2110 if (j == 0) {
2111 if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) !=
2112 SHF_ALLOC)
2113 continue;
2114 } else {
2115 if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) !=
2116 (SHF_ALLOC | SHF_WRITE))
2117 continue;
2118 }
2119 if (s == interp) {
2120 if (k != 0)
2121 continue;
2122 } else if (s->sh_type == SHT_DYNSYM ||
2123 s->sh_type == SHT_STRTAB ||
2124 s->sh_type == SHT_HASH) {
2125 if (k != 1)
2126 continue;
2127 } else if (s->sh_type == SHT_RELX) {
2128 if (k != 2)
2129 continue;
2130 } else if (s->sh_type == SHT_NOBITS) {
2131 if (k != 4)
2132 continue;
2133 } else {
2134 if (k != 3)
2135 continue;
2136 }
2137 sec_order[sh_order_index++] = i;
2138
2139 /* section matches: we align it and add its size */
2140 tmp = addr;
2141 addr = (addr + s->sh_addralign - 1) &
2142 ~(s->sh_addralign - 1);
2143 file_offset += (int) ( addr - tmp );
2144 s->sh_offset = file_offset;
2145 s->sh_addr = addr;
2146
2147 /* update program header infos */
2148 if (ph->p_offset == 0) {
2149 ph->p_offset = file_offset;
2150 ph->p_vaddr = addr;
2151 ph->p_paddr = ph->p_vaddr;
2152 }
2153 /* update dynamic relocation infos */
2154 if (s->sh_type == SHT_RELX) {
2155 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2156 if (!strcmp(strsec->data + s->sh_name, ".rel.got")) {
2157 dyninf->rel_addr = addr;
2158 dyninf->rel_size += s->sh_size; /* XXX only first rel. */
2159 }
2160 if (!strcmp(strsec->data + s->sh_name, ".rel.bss")) {
2161 dyninf->bss_addr = addr;
2162 dyninf->bss_size = s->sh_size; /* XXX only first rel. */
2163 }
2164 #else
2165 if (dyninf->rel_size == 0)
2166 dyninf->rel_addr = addr;
2167 dyninf->rel_size += s->sh_size;
2168 #endif
2169 }
2170 addr += s->sh_size;
2171 if (s->sh_type != SHT_NOBITS)
2172 file_offset += s->sh_size;
2173 }
2174 }
2175 if (j == 0) {
2176 /* Make the first PT_LOAD segment include the program
2177 headers itself (and the ELF header as well), it'll
2178 come out with same memory use but will make various
2179 tools like binutils strip work better. */
2180 ph->p_offset &= ~(ph->p_align - 1);
2181 ph->p_vaddr &= ~(ph->p_align - 1);
2182 ph->p_paddr &= ~(ph->p_align - 1);
2183 }
2184 ph->p_filesz = file_offset - ph->p_offset;
2185 ph->p_memsz = addr - ph->p_vaddr;
2186 ph++;
2187 if (j == 0) {
2188 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF) {
2189 /* if in the middle of a page, we duplicate the page in
2190 memory so that one copy is RX and the other is RW */
2191 if ((addr & (s_align - 1)) != 0)
2192 addr += s_align;
2193 } else {
2194 addr = (addr + s_align - 1) & ~(s_align - 1);
2195 file_offset = (file_offset + s_align - 1) & ~(s_align - 1);
2196 }
2197 }
2198 }
2199 }
2200
2201 /* all other sections come after */
2202 for(i = 1; i < s1->nb_sections; i++) {
2203 s = s1->sections[i];
2204 if (phnum > 0 && (s->sh_flags & SHF_ALLOC))
2205 continue;
2206 sec_order[sh_order_index++] = i;
2207
2208 file_offset = (file_offset + s->sh_addralign - 1) &
2209 ~(s->sh_addralign - 1);
2210 s->sh_offset = file_offset;
2211 if (s->sh_type != SHT_NOBITS)
2212 file_offset += s->sh_size;
2213 }
2214
2215 return file_offset;
2216 }
2217
2218 static void fill_unloadable_phdr(ElfW(Phdr) *phdr, int phnum, Section *interp,
2219 Section *dynamic)
2220 {
2221 ElfW(Phdr) *ph;
2222
2223 /* if interpreter, then add corresponding program header */
2224 if (interp) {
2225 ph = &phdr[0];
2226
2227 if (HAVE_PHDR)
2228 {
2229 int len = phnum * sizeof(ElfW(Phdr));
2230
2231 ph->p_type = PT_PHDR;
2232 ph->p_offset = sizeof(ElfW(Ehdr));
2233 ph->p_vaddr = interp->sh_addr - len;
2234 ph->p_paddr = ph->p_vaddr;
2235 ph->p_filesz = ph->p_memsz = len;
2236 ph->p_flags = PF_R | PF_X;
2237 ph->p_align = 4; /* interp->sh_addralign; */
2238 ph++;
2239 }
2240
2241 ph->p_type = PT_INTERP;
2242 ph->p_offset = interp->sh_offset;
2243 ph->p_vaddr = interp->sh_addr;
2244 ph->p_paddr = ph->p_vaddr;
2245 ph->p_filesz = interp->sh_size;
2246 ph->p_memsz = interp->sh_size;
2247 ph->p_flags = PF_R;
2248 ph->p_align = interp->sh_addralign;
2249 }
2250
2251 /* if dynamic section, then add corresponding program header */
2252 if (dynamic) {
2253 ph = &phdr[phnum - 1];
2254
2255 ph->p_type = PT_DYNAMIC;
2256 ph->p_offset = dynamic->sh_offset;
2257 ph->p_vaddr = dynamic->sh_addr;
2258 ph->p_paddr = ph->p_vaddr;
2259 ph->p_filesz = dynamic->sh_size;
2260 ph->p_memsz = dynamic->sh_size;
2261 ph->p_flags = PF_R | PF_W;
2262 ph->p_align = dynamic->sh_addralign;
2263 }
2264 }
2265
2266 /* Fill the dynamic section with tags describing the address and size of
2267 sections */
2268 static void fill_dynamic(TCCState *s1, struct dyn_inf *dyninf)
2269 {
2270 Section *dynamic;
2271
2272 dynamic = dyninf->dynamic;
2273
2274 /* put dynamic section entries */
2275 dynamic->data_offset = dyninf->dyn_rel_off;
2276 put_dt(dynamic, DT_HASH, s1->dynsym->hash->sh_addr);
2277 put_dt(dynamic, DT_STRTAB, dyninf->dynstr->sh_addr);
2278 put_dt(dynamic, DT_SYMTAB, s1->dynsym->sh_addr);
2279 put_dt(dynamic, DT_STRSZ, dyninf->dynstr->data_offset);
2280 put_dt(dynamic, DT_SYMENT, sizeof(ElfW(Sym)));
2281 #if defined(TCC_TARGET_ARM64) || defined(TCC_TARGET_X86_64)
2282 put_dt(dynamic, DT_RELA, dyninf->rel_addr);
2283 put_dt(dynamic, DT_RELASZ, dyninf->rel_size);
2284 put_dt(dynamic, DT_RELAENT, sizeof(ElfW_Rel));
2285 #else
2286 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2287 put_dt(dynamic, DT_PLTGOT, s1->got->sh_addr);
2288 put_dt(dynamic, DT_PLTRELSZ, dyninf->rel_size);
2289 put_dt(dynamic, DT_JMPREL, dyninf->rel_addr);
2290 put_dt(dynamic, DT_PLTREL, DT_REL);
2291 put_dt(dynamic, DT_REL, dyninf->bss_addr);
2292 put_dt(dynamic, DT_RELSZ, dyninf->bss_size);
2293 #else
2294 put_dt(dynamic, DT_REL, dyninf->rel_addr);
2295 put_dt(dynamic, DT_RELSZ, dyninf->rel_size);
2296 put_dt(dynamic, DT_RELENT, sizeof(ElfW_Rel));
2297 #endif
2298 #endif
2299 if (s1->do_debug)
2300 put_dt(dynamic, DT_DEBUG, 0);
2301 put_dt(dynamic, DT_NULL, 0);
2302 }
2303
2304 /* Relocate remaining sections and symbols (that is those not related to
2305 dynamic linking) */
2306 static int final_sections_reloc(TCCState *s1)
2307 {
2308 int i;
2309 Section *s;
2310
2311 relocate_syms(s1, 0);
2312
2313 if (s1->nb_errors != 0)
2314 return -1;
2315
2316 /* relocate sections */
2317 /* XXX: ignore sections with allocated relocations ? */
2318 for(i = 1; i < s1->nb_sections; i++) {
2319 s = s1->sections[i];
2320 #ifdef TCC_TARGET_I386
2321 if (s->reloc && s != s1->got && (s->sh_flags & SHF_ALLOC)) //gr
2322 /* On X86 gdb 7.3 works in any case but gdb 6.6 will crash if SHF_ALLOC
2323 checking is removed */
2324 #else
2325 if (s->reloc && s != s1->got)
2326 /* On X86_64 gdb 7.3 will crash if SHF_ALLOC checking is present */
2327 #endif
2328 relocate_section(s1, s);
2329 }
2330
2331 /* relocate relocation entries if the relocation tables are
2332 allocated in the executable */
2333 for(i = 1; i < s1->nb_sections; i++) {
2334 s = s1->sections[i];
2335 if ((s->sh_flags & SHF_ALLOC) &&
2336 s->sh_type == SHT_RELX) {
2337 relocate_rel(s1, s);
2338 }
2339 }
2340 return 0;
2341 }
2342
2343 /* Create an ELF file on disk.
2344 This function handle ELF specific layout requirements */
2345 static void tcc_output_elf(TCCState *s1, FILE *f, int phnum, ElfW(Phdr) *phdr,
2346 int file_offset, int *sec_order)
2347 {
2348 int i, shnum, offset, size, file_type;
2349 Section *s;
2350 ElfW(Ehdr) ehdr;
2351 ElfW(Shdr) shdr, *sh;
2352
2353 file_type = s1->output_type;
2354 shnum = s1->nb_sections;
2355
2356 memset(&ehdr, 0, sizeof(ehdr));
2357
2358 if (phnum > 0) {
2359 ehdr.e_phentsize = sizeof(ElfW(Phdr));
2360 ehdr.e_phnum = phnum;
2361 ehdr.e_phoff = sizeof(ElfW(Ehdr));
2362 }
2363
2364 /* align to 4 */
2365 file_offset = (file_offset + 3) & -4;
2366
2367 /* fill header */
2368 ehdr.e_ident[0] = ELFMAG0;
2369 ehdr.e_ident[1] = ELFMAG1;
2370 ehdr.e_ident[2] = ELFMAG2;
2371 ehdr.e_ident[3] = ELFMAG3;
2372 ehdr.e_ident[4] = ELFCLASSW;
2373 ehdr.e_ident[5] = ELFDATA2LSB;
2374 ehdr.e_ident[6] = EV_CURRENT;
2375 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2376 ehdr.e_ident[EI_OSABI] = ELFOSABI_FREEBSD;
2377 #endif
2378 #ifdef TCC_TARGET_ARM
2379 #ifdef TCC_ARM_EABI
2380 ehdr.e_ident[EI_OSABI] = 0;
2381 ehdr.e_flags = EF_ARM_EABI_VER4;
2382 if (file_type == TCC_OUTPUT_EXE || file_type == TCC_OUTPUT_DLL)
2383 ehdr.e_flags |= EF_ARM_HASENTRY;
2384 if (s1->float_abi == ARM_HARD_FLOAT)
2385 ehdr.e_flags |= EF_ARM_VFP_FLOAT;
2386 else
2387 ehdr.e_flags |= EF_ARM_SOFT_FLOAT;
2388 #else
2389 ehdr.e_ident[EI_OSABI] = ELFOSABI_ARM;
2390 #endif
2391 #endif
2392 switch(file_type) {
2393 default:
2394 case TCC_OUTPUT_EXE:
2395 ehdr.e_type = ET_EXEC;
2396 ehdr.e_entry = get_elf_sym_addr(s1, "_start", 1);
2397 break;
2398 case TCC_OUTPUT_DLL:
2399 ehdr.e_type = ET_DYN;
2400 ehdr.e_entry = text_section->sh_addr; /* XXX: is it correct ? */
2401 break;
2402 case TCC_OUTPUT_OBJ:
2403 ehdr.e_type = ET_REL;
2404 break;
2405 }
2406 ehdr.e_machine = EM_TCC_TARGET;
2407 ehdr.e_version = EV_CURRENT;
2408 ehdr.e_shoff = file_offset;
2409 ehdr.e_ehsize = sizeof(ElfW(Ehdr));
2410 ehdr.e_shentsize = sizeof(ElfW(Shdr));
2411 ehdr.e_shnum = shnum;
2412 ehdr.e_shstrndx = shnum - 1;
2413
2414 fwrite(&ehdr, 1, sizeof(ElfW(Ehdr)), f);
2415 fwrite(phdr, 1, phnum * sizeof(ElfW(Phdr)), f);
2416 offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr));
2417
2418 sort_syms(s1, symtab_section);
2419 for(i = 1; i < s1->nb_sections; i++) {
2420 s = s1->sections[sec_order[i]];
2421 if (s->sh_type != SHT_NOBITS) {
2422 if (s->sh_type == SHT_DYNSYM)
2423 patch_dynsym_undef(s1, s);
2424 while (offset < s->sh_offset) {
2425 fputc(0, f);
2426 offset++;
2427 }
2428 size = s->sh_size;
2429 fwrite(s->data, 1, size, f);
2430 offset += size;
2431 }
2432 }
2433
2434 /* output section headers */
2435 while (offset < ehdr.e_shoff) {
2436 fputc(0, f);
2437 offset++;
2438 }
2439
2440 for(i = 0; i < s1->nb_sections; i++) {
2441 sh = &shdr;
2442 memset(sh, 0, sizeof(ElfW(Shdr)));
2443 s = s1->sections[i];
2444 if (s) {
2445 sh->sh_name = s->sh_name;
2446 sh->sh_type = s->sh_type;
2447 sh->sh_flags = s->sh_flags;
2448 sh->sh_entsize = s->sh_entsize;
2449 sh->sh_info = s->sh_info;
2450 if (s->link)
2451 sh->sh_link = s->link->sh_num;
2452 sh->sh_addralign = s->sh_addralign;
2453 sh->sh_addr = s->sh_addr;
2454 sh->sh_offset = s->sh_offset;
2455 sh->sh_size = s->sh_size;
2456 }
2457 fwrite(sh, 1, sizeof(ElfW(Shdr)), f);
2458 }
2459 }
2460
2461 /* Write an elf, coff or "binary" file */
2462 static int tcc_write_elf_file(TCCState *s1, const char *filename, int phnum,
2463 ElfW(Phdr) *phdr, int file_offset, int *sec_order)
2464 {
2465 int fd, mode, file_type;
2466 FILE *f;
2467
2468 file_type = s1->output_type;
2469 if (file_type == TCC_OUTPUT_OBJ)
2470 mode = 0666;
2471 else
2472 mode = 0777;
2473 unlink(filename);
2474 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, mode);
2475 if (fd < 0) {
2476 tcc_error_noabort("could not write '%s'", filename);
2477 return -1;
2478 }
2479 f = fdopen(fd, "wb");
2480 if (s1->verbose)
2481 printf("<- %s\n", filename);
2482
2483 #ifdef TCC_TARGET_COFF
2484 if (s1->output_format == TCC_OUTPUT_FORMAT_COFF)
2485 tcc_output_coff(s1, f);
2486 else
2487 #endif
2488 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF)
2489 tcc_output_elf(s1, f, phnum, phdr, file_offset, sec_order);
2490 else
2491 tcc_output_binary(s1, f, sec_order);
2492 fclose(f);
2493
2494 return 0;
2495 }
2496
2497 /* Output an elf, coff or binary file */
2498 /* XXX: suppress unneeded sections */
2499 static int elf_output_file(TCCState *s1, const char *filename)
2500 {
2501 int i, ret, phnum, shnum, file_type, file_offset, *sec_order;
2502 struct dyn_inf dyninf;
2503 ElfW(Phdr) *phdr;
2504 ElfW(Sym) *sym;
2505 Section *strsec, *interp, *dynamic, *dynstr;
2506
2507 file_type = s1->output_type;
2508 s1->nb_errors = 0;
2509
2510 /* if linking, also link in runtime libraries (libc, libgcc, etc.) */
2511 if (file_type != TCC_OUTPUT_OBJ) {
2512 tcc_add_runtime(s1);
2513 }
2514
2515 phdr = NULL;
2516 sec_order = NULL;
2517 interp = dynamic = dynstr = NULL; /* avoid warning */
2518 dyninf.dyn_rel_off = 0; /* avoid warning */
2519
2520 if (file_type != TCC_OUTPUT_OBJ) {
2521 relocate_common_syms();
2522
2523 tcc_add_linker_symbols(s1);
2524
2525 if (!s1->static_link) {
2526 if (file_type == TCC_OUTPUT_EXE) {
2527 char *ptr;
2528 /* allow override the dynamic loader */
2529 const char *elfint = getenv("LD_SO");
2530 if (elfint == NULL)
2531 elfint = DEFAULT_ELFINTERP(s1);
2532 /* add interpreter section only if executable */
2533 interp = new_section(s1, ".interp", SHT_PROGBITS, SHF_ALLOC);
2534 interp->sh_addralign = 1;
2535 ptr = section_ptr_add(interp, 1 + strlen(elfint));
2536 strcpy(ptr, elfint);
2537 }
2538
2539 /* add dynamic symbol table */
2540 s1->dynsym = new_symtab(s1, ".dynsym", SHT_DYNSYM, SHF_ALLOC,
2541 ".dynstr",
2542 ".hash", SHF_ALLOC);
2543 dynstr = s1->dynsym->link;
2544
2545 /* add dynamic section */
2546 dynamic = new_section(s1, ".dynamic", SHT_DYNAMIC,
2547 SHF_ALLOC | SHF_WRITE);
2548 dynamic->link = dynstr;
2549 dynamic->sh_entsize = sizeof(ElfW(Dyn));
2550
2551 build_got(s1);
2552
2553 if (file_type == TCC_OUTPUT_EXE) {
2554 bind_exe_dynsyms(s1);
2555
2556 if (s1->nb_errors) {
2557 ret = -1;
2558 goto the_end;
2559 }
2560
2561 bind_libs_dynsyms(s1);
2562 } else /* shared library case: simply export all global symbols */
2563 export_global_syms(s1);
2564
2565 build_got_entries(s1);
2566
2567 /* add a list of needed dlls */
2568 for(i = 0; i < s1->nb_loaded_dlls; i++) {
2569 DLLReference *dllref = s1->loaded_dlls[i];
2570 if (dllref->level == 0)
2571 put_dt(dynamic, DT_NEEDED, put_elf_str(dynstr, dllref->name));
2572 }
2573
2574 if (s1->rpath)
2575 put_dt(dynamic, DT_RPATH, put_elf_str(dynstr, s1->rpath));
2576
2577 /* XXX: currently, since we do not handle PIC code, we
2578 must relocate the readonly segments */
2579 if (file_type == TCC_OUTPUT_DLL) {
2580 if (s1->soname)
2581 put_dt(dynamic, DT_SONAME, put_elf_str(dynstr, s1->soname));
2582 put_dt(dynamic, DT_TEXTREL, 0);
2583 }
2584
2585 if (s1->symbolic)
2586 put_dt(dynamic, DT_SYMBOLIC, 0);
2587
2588 /* add necessary space for other entries */
2589 dyninf.dyn_rel_off = dynamic->data_offset;
2590 dynamic->data_offset += sizeof(ElfW(Dyn)) * EXTRA_RELITEMS;
2591 } else {
2592 /* still need to build got entries in case of static link */
2593 build_got_entries(s1);
2594 }
2595 }
2596
2597 /* we add a section for symbols */
2598 strsec = new_section(s1, ".shstrtab", SHT_STRTAB, 0);
2599 put_elf_str(strsec, "");
2600
2601 /* compute number of sections */
2602 shnum = s1->nb_sections;
2603
2604 /* this array is used to reorder sections in the output file */
2605 sec_order = tcc_malloc(sizeof(int) * shnum);
2606 sec_order[0] = 0;
2607
2608 /* compute number of program headers */
2609 switch(file_type) {
2610 default:
2611 case TCC_OUTPUT_OBJ:
2612 phnum = 0;
2613 break;
2614 case TCC_OUTPUT_EXE:
2615 if (!s1->static_link)
2616 phnum = 4 + HAVE_PHDR;
2617 else
2618 phnum = 2;
2619 break;
2620 case TCC_OUTPUT_DLL:
2621 phnum = 3;
2622 break;
2623 }
2624
2625 /* Allocate strings for section names */
2626 alloc_sec_names(s1, file_type, strsec);
2627
2628 /* allocate program segment headers */
2629 phdr = tcc_mallocz(phnum * sizeof(ElfW(Phdr)));
2630
2631 /* compute section to program header mapping */
2632 file_offset = layout_sections(s1, phdr, phnum, interp, strsec, &dyninf,
2633 sec_order);
2634
2635 /* Fill remaining program header and finalize relocation related to dynamic
2636 linking. */
2637 if (phnum > 0) {
2638 fill_unloadable_phdr(phdr, phnum, interp, dynamic);
2639 if (dynamic) {
2640 dyninf.dynamic = dynamic;
2641 dyninf.dynstr = dynstr;
2642
2643 fill_dynamic(s1, &dyninf);
2644
2645 /* put in GOT the dynamic section address and relocate PLT */
2646 put32(s1->got->data, dynamic->sh_addr);
2647 if (file_type == TCC_OUTPUT_EXE
2648 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
2649 || file_type == TCC_OUTPUT_DLL
2650 #endif
2651 )
2652 relocate_plt(s1);
2653
2654 /* relocate symbols in .dynsym now that final addresses are known */
2655 for_each_elem(s1->dynsym, 1, sym, ElfW(Sym)) {
2656 if (sym->st_shndx == SHN_UNDEF) {
2657 /* relocate to PLT if symbol corresponds to a PLT entry,
2658 but not if it's a weak symbol */
2659 if (ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
2660 sym->st_value = 0;
2661 else if (sym->st_value)
2662 sym->st_value += s1->plt->sh_addr;
2663 } else if (sym->st_shndx < SHN_LORESERVE) {
2664 /* do symbol relocation */
2665 sym->st_value += s1->sections[sym->st_shndx]->sh_addr;
2666 }
2667 }
2668 }
2669 }
2670
2671 /* if building executable or DLL, then relocate each section
2672 except the GOT which is already relocated */
2673 if (file_type != TCC_OUTPUT_OBJ) {
2674 ret = final_sections_reloc(s1);
2675 if (ret)
2676 goto the_end;
2677 }
2678
2679 /* Perform relocation to GOT or PLT entries */
2680 if (file_type == TCC_OUTPUT_EXE && s1->static_link)
2681 fill_got(s1);
2682
2683 /* Create the ELF file with name 'filename' */
2684 ret = tcc_write_elf_file(s1, filename, phnum, phdr, file_offset, sec_order);
2685 the_end:
2686 tcc_free(s1->symtab_to_dynsym);
2687 tcc_free(sec_order);
2688 tcc_free(phdr);
2689 tcc_free(s1->sym_attrs);
2690 s1->sym_attrs = NULL;
2691 return ret;
2692 }
2693
2694 LIBTCCAPI int tcc_output_file(TCCState *s, const char *filename)
2695 {
2696 int ret;
2697 #ifdef TCC_TARGET_PE
2698 if (s->output_type != TCC_OUTPUT_OBJ) {
2699 ret = pe_output_file(s, filename);
2700 } else
2701 #endif
2702 ret = elf_output_file(s, filename);
2703 return ret;
2704 }
2705
2706 static void *load_data(int fd, unsigned long file_offset, unsigned long size)
2707 {
2708 void *data;
2709
2710 data = tcc_malloc(size);
2711 lseek(fd, file_offset, SEEK_SET);
2712 read(fd, data, size);
2713 return data;
2714 }
2715
2716 typedef struct SectionMergeInfo {
2717 Section *s; /* corresponding existing section */
2718 unsigned long offset; /* offset of the new section in the existing section */
2719 uint8_t new_section; /* true if section 's' was added */
2720 uint8_t link_once; /* true if link once section */
2721 } SectionMergeInfo;
2722
2723 /* load an object file and merge it with current files */
2724 /* XXX: handle correctly stab (debug) info */
2725 ST_FUNC int tcc_load_object_file(TCCState *s1,
2726 int fd, unsigned long file_offset)
2727 {
2728 ElfW(Ehdr) ehdr;
2729 ElfW(Shdr) *shdr, *sh;
2730 int size, i, j, offset, offseti, nb_syms, sym_index, ret;
2731 unsigned char *strsec, *strtab;
2732 int *old_to_new_syms;
2733 char *sh_name, *name;
2734 SectionMergeInfo *sm_table, *sm;
2735 ElfW(Sym) *sym, *symtab;
2736 ElfW_Rel *rel;
2737 Section *s;
2738
2739 int stab_index;
2740 int stabstr_index;
2741
2742 stab_index = stabstr_index = 0;
2743
2744 if (read(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr))
2745 goto fail1;
2746 if (ehdr.e_ident[0] != ELFMAG0 ||
2747 ehdr.e_ident[1] != ELFMAG1 ||
2748 ehdr.e_ident[2] != ELFMAG2 ||
2749 ehdr.e_ident[3] != ELFMAG3)
2750 goto fail1;
2751 /* test if object file */
2752 if (ehdr.e_type != ET_REL)
2753 goto fail1;
2754 /* test CPU specific stuff */
2755 if (ehdr.e_ident[5] != ELFDATA2LSB ||
2756 ehdr.e_machine != EM_TCC_TARGET) {
2757 fail1:
2758 tcc_error_noabort("invalid object file");
2759 return -1;
2760 }
2761 /* read sections */
2762 shdr = load_data(fd, file_offset + ehdr.e_shoff,
2763 sizeof(ElfW(Shdr)) * ehdr.e_shnum);
2764 sm_table = tcc_mallocz(sizeof(SectionMergeInfo) * ehdr.e_shnum);
2765
2766 /* load section names */
2767 sh = &shdr[ehdr.e_shstrndx];
2768 strsec = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2769
2770 /* load symtab and strtab */
2771 old_to_new_syms = NULL;
2772 symtab = NULL;
2773 strtab = NULL;
2774 nb_syms = 0;
2775 for(i = 1; i < ehdr.e_shnum; i++) {
2776 sh = &shdr[i];
2777 if (sh->sh_type == SHT_SYMTAB) {
2778 if (symtab) {
2779 tcc_error_noabort("object must contain only one symtab");
2780 fail:
2781 ret = -1;
2782 goto the_end;
2783 }
2784 nb_syms = sh->sh_size / sizeof(ElfW(Sym));
2785 symtab = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2786 sm_table[i].s = symtab_section;
2787
2788 /* now load strtab */
2789 sh = &shdr[sh->sh_link];
2790 strtab = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2791 }
2792 }
2793
2794 /* now examine each section and try to merge its content with the
2795 ones in memory */
2796 for(i = 1; i < ehdr.e_shnum; i++) {
2797 /* no need to examine section name strtab */
2798 if (i == ehdr.e_shstrndx)
2799 continue;
2800 sh = &shdr[i];
2801 sh_name = (char *) strsec + sh->sh_name;
2802 /* ignore sections types we do not handle */
2803 if (sh->sh_type != SHT_PROGBITS &&
2804 sh->sh_type != SHT_RELX &&
2805 #ifdef TCC_ARM_EABI
2806 sh->sh_type != SHT_ARM_EXIDX &&
2807 #endif
2808 sh->sh_type != SHT_NOBITS &&
2809 sh->sh_type != SHT_PREINIT_ARRAY &&
2810 sh->sh_type != SHT_INIT_ARRAY &&
2811 sh->sh_type != SHT_FINI_ARRAY &&
2812 strcmp(sh_name, ".stabstr")
2813 )
2814 continue;
2815 if (sh->sh_addralign < 1)
2816 sh->sh_addralign = 1;
2817 /* find corresponding section, if any */
2818 for(j = 1; j < s1->nb_sections;j++) {
2819 s = s1->sections[j];
2820 if (!strcmp(s->name, sh_name)) {
2821 if (!strncmp(sh_name, ".gnu.linkonce",
2822 sizeof(".gnu.linkonce") - 1)) {
2823 /* if a 'linkonce' section is already present, we
2824 do not add it again. It is a little tricky as
2825 symbols can still be defined in
2826 it. */
2827 sm_table[i].link_once = 1;
2828 goto next;
2829 } else {
2830 goto found;
2831 }
2832 }
2833 }
2834 /* not found: create new section */
2835 s = new_section(s1, sh_name, sh->sh_type, sh->sh_flags);
2836 /* take as much info as possible from the section. sh_link and
2837 sh_info will be updated later */
2838 s->sh_addralign = sh->sh_addralign;
2839 s->sh_entsize = sh->sh_entsize;
2840 sm_table[i].new_section = 1;
2841 found:
2842 if (sh->sh_type != s->sh_type) {
2843 tcc_error_noabort("invalid section type");
2844 goto fail;
2845 }
2846
2847 /* align start of section */
2848 offset = s->data_offset;
2849
2850 if (0 == strcmp(sh_name, ".stab")) {
2851 stab_index = i;
2852 goto no_align;
2853 }
2854 if (0 == strcmp(sh_name, ".stabstr")) {
2855 stabstr_index = i;
2856 goto no_align;
2857 }
2858
2859 size = sh->sh_addralign - 1;
2860 offset = (offset + size) & ~size;
2861 if (sh->sh_addralign > s->sh_addralign)
2862 s->sh_addralign = sh->sh_addralign;
2863 s->data_offset = offset;
2864 no_align:
2865 sm_table[i].offset = offset;
2866 sm_table[i].s = s;
2867 /* concatenate sections */
2868 size = sh->sh_size;
2869 if (sh->sh_type != SHT_NOBITS) {
2870 unsigned char *ptr;
2871 lseek(fd, file_offset + sh->sh_offset, SEEK_SET);
2872 ptr = section_ptr_add(s, size);
2873 read(fd, ptr, size);
2874 } else {
2875 s->data_offset += size;
2876 }
2877 next: ;
2878 }
2879
2880 /* gr relocate stab strings */
2881 if (stab_index && stabstr_index) {
2882 Stab_Sym *a, *b;
2883 unsigned o;
2884 s = sm_table[stab_index].s;
2885 a = (Stab_Sym *)(s->data + sm_table[stab_index].offset);
2886 b = (Stab_Sym *)(s->data + s->data_offset);
2887 o = sm_table[stabstr_index].offset;
2888 while (a < b)
2889 a->n_strx += o, a++;
2890 }
2891
2892 /* second short pass to update sh_link and sh_info fields of new
2893 sections */
2894 for(i = 1; i < ehdr.e_shnum; i++) {
2895 s = sm_table[i].s;
2896 if (!s || !sm_table[i].new_section)
2897 continue;
2898 sh = &shdr[i];
2899 if (sh->sh_link > 0)
2900 s->link = sm_table[sh->sh_link].s;
2901 if (sh->sh_type == SHT_RELX) {
2902 s->sh_info = sm_table[sh->sh_info].s->sh_num;
2903 /* update backward link */
2904 s1->sections[s->sh_info]->reloc = s;
2905 }
2906 }
2907 sm = sm_table;
2908
2909 /* resolve symbols */
2910 old_to_new_syms = tcc_mallocz(nb_syms * sizeof(int));
2911
2912 sym = symtab + 1;
2913 for(i = 1; i < nb_syms; i++, sym++) {
2914 if (sym->st_shndx != SHN_UNDEF &&
2915 sym->st_shndx < SHN_LORESERVE) {
2916 sm = &sm_table[sym->st_shndx];
2917 if (sm->link_once) {
2918 /* if a symbol is in a link once section, we use the
2919 already defined symbol. It is very important to get
2920 correct relocations */
2921 if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
2922 name = (char *) strtab + sym->st_name;
2923 sym_index = find_elf_sym(symtab_section, name);
2924 if (sym_index)
2925 old_to_new_syms[i] = sym_index;
2926 }
2927 continue;
2928 }
2929 /* if no corresponding section added, no need to add symbol */
2930 if (!sm->s)
2931 continue;
2932 /* convert section number */
2933 sym->st_shndx = sm->s->sh_num;
2934 /* offset value */
2935 sym->st_value += sm->offset;
2936 }
2937 /* add symbol */
2938 name = (char *) strtab + sym->st_name;
2939 sym_index = add_elf_sym(symtab_section, sym->st_value, sym->st_size,
2940 sym->st_info, sym->st_other,
2941 sym->st_shndx, name);
2942 old_to_new_syms[i] = sym_index;
2943 }
2944
2945 /* third pass to patch relocation entries */
2946 for(i = 1; i < ehdr.e_shnum; i++) {
2947 s = sm_table[i].s;
2948 if (!s)
2949 continue;
2950 sh = &shdr[i];
2951 offset = sm_table[i].offset;
2952 switch(s->sh_type) {
2953 case SHT_RELX:
2954 /* take relocation offset information */
2955 offseti = sm_table[sh->sh_info].offset;
2956 for_each_elem(s, (offset / sizeof(*rel)), rel, ElfW_Rel) {
2957 int type;
2958 unsigned sym_index;
2959 /* convert symbol index */
2960 type = ELFW(R_TYPE)(rel->r_info);
2961 sym_index = ELFW(R_SYM)(rel->r_info);
2962 /* NOTE: only one symtab assumed */
2963 if (sym_index >= nb_syms)
2964 goto invalid_reloc;
2965 sym_index = old_to_new_syms[sym_index];
2966 /* ignore link_once in rel section. */
2967 if (!sym_index && !sm->link_once
2968 #ifdef TCC_TARGET_ARM
2969 && type != R_ARM_V4BX
2970 #endif
2971 ) {
2972 invalid_reloc:
2973 tcc_error_noabort("Invalid relocation entry [%2d] '%s' @ %.8x",
2974 i, strsec + sh->sh_name, rel->r_offset);
2975 goto fail;
2976 }
2977 rel->r_info = ELFW(R_INFO)(sym_index, type);
2978 /* offset the relocation offset */
2979 rel->r_offset += offseti;
2980 #ifdef TCC_TARGET_ARM
2981 /* Jumps and branches from a Thumb code to a PLT entry need
2982 special handling since PLT entries are ARM code.
2983 Unconditional bl instructions referencing PLT entries are
2984 handled by converting these instructions into blx
2985 instructions. Other case of instructions referencing a PLT
2986 entry require to add a Thumb stub before the PLT entry to
2987 switch to ARM mode. We set bit plt_thumb_stub of the
2988 attribute of a symbol to indicate such a case. */
2989 if (type == R_ARM_THM_JUMP24)
2990 alloc_sym_attr(s1, sym_index)->plt_thumb_stub = 1;
2991 #endif
2992 }
2993 break;
2994 default:
2995 break;
2996 }
2997 }
2998
2999 ret = 0;
3000 the_end:
3001 tcc_free(symtab);
3002 tcc_free(strtab);
3003 tcc_free(old_to_new_syms);
3004 tcc_free(sm_table);
3005 tcc_free(strsec);
3006 tcc_free(shdr);
3007 return ret;
3008 }
3009
3010 typedef struct ArchiveHeader {
3011 char ar_name[16]; /* name of this member */
3012 char ar_date[12]; /* file mtime */
3013 char ar_uid[6]; /* owner uid; printed as decimal */
3014 char ar_gid[6]; /* owner gid; printed as decimal */
3015 char ar_mode[8]; /* file mode, printed as octal */
3016 char ar_size[10]; /* file size, printed as decimal */
3017 char ar_fmag[2]; /* should contain ARFMAG */
3018 } ArchiveHeader;
3019
3020 static int get_be32(const uint8_t *b)
3021 {
3022 return b[3] | (b[2] << 8) | (b[1] << 16) | (b[0] << 24);
3023 }
3024
3025 /* load only the objects which resolve undefined symbols */
3026 static int tcc_load_alacarte(TCCState *s1, int fd, int size)
3027 {
3028 int i, bound, nsyms, sym_index, off, ret;
3029 uint8_t *data;
3030 const char *ar_names, *p;
3031 const uint8_t *ar_index;
3032 ElfW(Sym) *sym;
3033
3034 data = tcc_malloc(size);
3035 if (read(fd, data, size) != size)
3036 goto fail;
3037 nsyms = get_be32(data);
3038 ar_index = data + 4;
3039 ar_names = (char *) ar_index + nsyms * 4;
3040
3041 do {
3042 bound = 0;
3043 for(p = ar_names, i = 0; i < nsyms; i++, p += strlen(p)+1) {
3044 sym_index = find_elf_sym(symtab_section, p);
3045 if(sym_index) {
3046 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
3047 if(sym->st_shndx == SHN_UNDEF) {
3048 off = get_be32(ar_index + i * 4) + sizeof(ArchiveHeader);
3049 ++bound;
3050 lseek(fd, off, SEEK_SET);
3051 if(tcc_load_object_file(s1, fd, off) < 0) {
3052 fail:
3053 ret = -1;
3054 goto the_end;
3055 }
3056 }
3057 }
3058 }
3059 } while(bound);
3060 ret = 0;
3061 the_end:
3062 tcc_free(data);
3063 return ret;
3064 }
3065
3066 /* load a '.a' file */
3067 ST_FUNC int tcc_load_archive(TCCState *s1, int fd)
3068 {
3069 ArchiveHeader hdr;
3070 char ar_size[11];
3071 char ar_name[17];
3072 char magic[8];
3073 int size, len, i;
3074 unsigned long file_offset;
3075
3076 /* skip magic which was already checked */
3077 read(fd, magic, sizeof(magic));
3078
3079 for(;;) {
3080 len = read(fd, &hdr, sizeof(hdr));
3081 if (len == 0)
3082 break;
3083 if (len != sizeof(hdr)) {
3084 tcc_error_noabort("invalid archive");
3085 return -1;
3086 }
3087 memcpy(ar_size, hdr.ar_size, sizeof(hdr.ar_size));
3088 ar_size[sizeof(hdr.ar_size)] = '\0';
3089 size = strtol(ar_size, NULL, 0);
3090 memcpy(ar_name, hdr.ar_name, sizeof(hdr.ar_name));
3091 for(i = sizeof(hdr.ar_name) - 1; i >= 0; i--) {
3092 if (ar_name[i] != ' ')
3093 break;
3094 }
3095 ar_name[i + 1] = '\0';
3096 file_offset = lseek(fd, 0, SEEK_CUR);
3097 /* align to even */
3098 size = (size + 1) & ~1;
3099 if (!strcmp(ar_name, "/")) {
3100 /* coff symbol table : we handle it */
3101 if(s1->alacarte_link)
3102 return tcc_load_alacarte(s1, fd, size);
3103 } else if (!strcmp(ar_name, "//") ||
3104 !strcmp(ar_name, "__.SYMDEF") ||
3105 !strcmp(ar_name, "__.SYMDEF/") ||
3106 !strcmp(ar_name, "ARFILENAMES/")) {
3107 /* skip symbol table or archive names */
3108 } else {
3109 if (tcc_load_object_file(s1, fd, file_offset) < 0)
3110 return -1;
3111 }
3112 lseek(fd, file_offset + size, SEEK_SET);
3113 }
3114 return 0;
3115 }
3116
3117 #ifndef TCC_TARGET_PE
3118 /* load a DLL and all referenced DLLs. 'level = 0' means that the DLL
3119 is referenced by the user (so it should be added as DT_NEEDED in
3120 the generated ELF file) */
3121 ST_FUNC int tcc_load_dll(TCCState *s1, int fd, const char *filename, int level)
3122 {
3123 ElfW(Ehdr) ehdr;
3124 ElfW(Shdr) *shdr, *sh, *sh1;
3125 int i, j, nb_syms, nb_dts, sym_bind, ret;
3126 ElfW(Sym) *sym, *dynsym;
3127 ElfW(Dyn) *dt, *dynamic;
3128 unsigned char *dynstr;
3129 const char *name, *soname;
3130 DLLReference *dllref;
3131
3132 read(fd, &ehdr, sizeof(ehdr));
3133
3134 /* test CPU specific stuff */
3135 if (ehdr.e_ident[5] != ELFDATA2LSB ||
3136 ehdr.e_machine != EM_TCC_TARGET) {
3137 tcc_error_noabort("bad architecture");
3138 return -1;
3139 }
3140
3141 /* read sections */
3142 shdr = load_data(fd, ehdr.e_shoff, sizeof(ElfW(Shdr)) * ehdr.e_shnum);
3143
3144 /* load dynamic section and dynamic symbols */
3145 nb_syms = 0;
3146 nb_dts = 0;
3147 dynamic = NULL;
3148 dynsym = NULL; /* avoid warning */
3149 dynstr = NULL; /* avoid warning */
3150 for(i = 0, sh = shdr; i < ehdr.e_shnum; i++, sh++) {
3151 switch(sh->sh_type) {
3152 case SHT_DYNAMIC:
3153 nb_dts = sh->sh_size / sizeof(ElfW(Dyn));
3154 dynamic = load_data(fd, sh->sh_offset, sh->sh_size);
3155 break;
3156 case SHT_DYNSYM:
3157 nb_syms = sh->sh_size / sizeof(ElfW(Sym));
3158 dynsym = load_data(fd, sh->sh_offset, sh->sh_size);
3159 sh1 = &shdr[sh->sh_link];
3160 dynstr = load_data(fd, sh1->sh_offset, sh1->sh_size);
3161 break;
3162 default:
3163 break;
3164 }
3165 }
3166
3167 /* compute the real library name */
3168 soname = tcc_basename(filename);
3169
3170 for(i = 0, dt = dynamic; i < nb_dts; i++, dt++) {
3171 if (dt->d_tag == DT_SONAME) {
3172 soname = (char *) dynstr + dt->d_un.d_val;
3173 }
3174 }
3175
3176 /* if the dll is already loaded, do not load it */
3177 for(i = 0; i < s1->nb_loaded_dlls; i++) {
3178 dllref = s1->loaded_dlls[i];
3179 if (!strcmp(soname, dllref->name)) {
3180 /* but update level if needed */
3181 if (level < dllref->level)
3182 dllref->level = level;
3183 ret = 0;
3184 goto the_end;
3185 }
3186 }
3187
3188 /* add the dll and its level */
3189 dllref = tcc_mallocz(sizeof(DLLReference) + strlen(soname));
3190 dllref->level = level;
3191 strcpy(dllref->name, soname);
3192 dynarray_add((void ***)&s1->loaded_dlls, &s1->nb_loaded_dlls, dllref);
3193
3194 /* add dynamic symbols in dynsym_section */
3195 for(i = 1, sym = dynsym + 1; i < nb_syms; i++, sym++) {
3196 sym_bind = ELFW(ST_BIND)(sym->st_info);
3197 if (sym_bind == STB_LOCAL)
3198 continue;
3199 name = (char *) dynstr + sym->st_name;
3200 add_elf_sym(s1->dynsymtab_section, sym->st_value, sym->st_size,
3201 sym->st_info, sym->st_other, sym->st_shndx, name);
3202 }
3203
3204 /* load all referenced DLLs */
3205 for(i = 0, dt = dynamic; i < nb_dts; i++, dt++) {
3206 switch(dt->d_tag) {
3207 case DT_NEEDED:
3208 name = (char *) dynstr + dt->d_un.d_val;
3209 for(j = 0; j < s1->nb_loaded_dlls; j++) {
3210 dllref = s1->loaded_dlls[j];
3211 if (!strcmp(name, dllref->name))
3212 goto already_loaded;
3213 }
3214 if (tcc_add_dll(s1, name, AFF_REFERENCED_DLL) < 0) {
3215 tcc_error_noabort("referenced dll '%s' not found", name);
3216 ret = -1;
3217 goto the_end;
3218 }
3219 already_loaded:
3220 break;
3221 }
3222 }
3223 ret = 0;
3224 the_end:
3225 tcc_free(dynstr);
3226 tcc_free(dynsym);
3227 tcc_free(dynamic);
3228 tcc_free(shdr);
3229 return ret;
3230 }
3231
3232 #define LD_TOK_NAME 256
3233 #define LD_TOK_EOF (-1)
3234
3235 /* return next ld script token */
3236 static int ld_next(TCCState *s1, char *name, int name_size)
3237 {
3238 int c;
3239 char *q;
3240
3241 redo:
3242 switch(ch) {
3243 case ' ':
3244 case '\t':
3245 case '\f':
3246 case '\v':
3247 case '\r':
3248 case '\n':
3249 inp();
3250 goto redo;
3251 case '/':
3252 minp();
3253 if (ch == '*') {
3254 file->buf_ptr = parse_comment(file->buf_ptr);
3255 ch = file->buf_ptr[0];
3256 goto redo;
3257 } else {
3258 q = name;
3259 *q++ = '/';
3260 goto parse_name;
3261 }
3262 break;
3263 /* case 'a' ... 'z': */
3264 case 'a':
3265 case 'b':
3266 case 'c':
3267 case 'd':
3268 case 'e':
3269 case 'f':
3270 case 'g':
3271 case 'h':
3272 case 'i':
3273 case 'j':
3274 case 'k':
3275 case 'l':
3276 case 'm':
3277 case 'n':
3278 case 'o':
3279 case 'p':
3280 case 'q':
3281 case 'r':
3282 case 's':
3283 case 't':
3284 case 'u':
3285 case 'v':
3286 case 'w':
3287 case 'x':
3288 case 'y':
3289 case 'z':
3290 /* case 'A' ... 'z': */
3291 case 'A':
3292 case 'B':
3293 case 'C':
3294 case 'D':
3295 case 'E':
3296 case 'F':
3297 case 'G':
3298 case 'H':
3299 case 'I':
3300 case 'J':
3301 case 'K':
3302 case 'L':
3303 case 'M':
3304 case 'N':
3305 case 'O':
3306 case 'P':
3307 case 'Q':
3308 case 'R':
3309 case 'S':
3310 case 'T':
3311 case 'U':
3312 case 'V':
3313 case 'W':
3314 case 'X':
3315 case 'Y':
3316 case 'Z':
3317 case '_':
3318 case '\\':
3319 case '.':
3320 case '$':
3321 case '~':
3322 q = name;
3323 parse_name:
3324 for(;;) {
3325 if (!((ch >= 'a' && ch <= 'z') ||
3326 (ch >= 'A' && ch <= 'Z') ||
3327 (ch >= '0' && ch <= '9') ||
3328 strchr("/.-_+=$:\\,~", ch)))
3329 break;
3330 if ((q - name) < name_size - 1) {
3331 *q++ = ch;
3332 }
3333 minp();
3334 }
3335 *q = '\0';
3336 c = LD_TOK_NAME;
3337 break;
3338 case CH_EOF:
3339 c = LD_TOK_EOF;
3340 break;
3341 default:
3342 c = ch;
3343 inp();
3344 break;
3345 }
3346 return c;
3347 }
3348
3349 static int ld_add_file(TCCState *s1, const char filename[])
3350 {
3351 int ret;
3352
3353 ret = tcc_add_file_internal(s1, filename, 0);
3354 if (ret)
3355 ret = tcc_add_dll(s1, filename, 0);
3356 return ret;
3357 }
3358
3359 static inline int new_undef_syms(void)
3360 {
3361 int ret = 0;
3362 ret = new_undef_sym;
3363 new_undef_sym = 0;
3364 return ret;
3365 }
3366
3367 static int ld_add_file_list(TCCState *s1, const char *cmd, int as_needed)
3368 {
3369 char filename[1024], libname[1024];
3370 int t, group, nblibs = 0, ret = 0;
3371 char **libs = NULL;
3372
3373 group = !strcmp(cmd, "GROUP");
3374 if (!as_needed)
3375 new_undef_syms();
3376 t = ld_next(s1, filename, sizeof(filename));
3377 if (t != '(')
3378 expect("(");
3379 t = ld_next(s1, filename, sizeof(filename));
3380 for(;;) {
3381 libname[0] = '\0';
3382 if (t == LD_TOK_EOF) {
3383 tcc_error_noabort("unexpected end of file");
3384 ret = -1;
3385 goto lib_parse_error;
3386 } else if (t == ')') {
3387 break;
3388 } else if (t == '-') {
3389 t = ld_next(s1, filename, sizeof(filename));
3390 if ((t != LD_TOK_NAME) || (filename[0] != 'l')) {
3391 tcc_error_noabort("library name expected");
3392 ret = -1;
3393 goto lib_parse_error;
3394 }
3395 pstrcpy(libname, sizeof libname, &filename[1]);
3396 if (s1->static_link) {
3397 snprintf(filename, sizeof filename, "lib%s.a", libname);
3398 } else {
3399 snprintf(filename, sizeof filename, "lib%s.so", libname);
3400 }
3401 } else if (t != LD_TOK_NAME) {
3402 tcc_error_noabort("filename expected");
3403 ret = -1;
3404 goto lib_parse_error;
3405 }
3406 if (!strcmp(filename, "AS_NEEDED")) {
3407 ret = ld_add_file_list(s1, cmd, 1);
3408 if (ret)
3409 goto lib_parse_error;
3410 } else {
3411 /* TODO: Implement AS_NEEDED support. Ignore it for now */
3412 if (!as_needed) {
3413 ret = ld_add_file(s1, filename);
3414 if (ret)
3415 goto lib_parse_error;
3416 if (group) {
3417 /* Add the filename *and* the libname to avoid future conversions */
3418 dynarray_add((void ***) &libs, &nblibs, tcc_strdup(filename));
3419 if (libname[0] != '\0')
3420 dynarray_add((void ***) &libs, &nblibs, tcc_strdup(libname));
3421 }
3422 }
3423 }
3424 t = ld_next(s1, filename, sizeof(filename));
3425 if (t == ',') {
3426 t = ld_next(s1, filename, sizeof(filename));
3427 }
3428 }
3429 if (group && !as_needed) {
3430 while (new_undef_syms()) {
3431 int i;
3432
3433 for (i = 0; i < nblibs; i ++)
3434 ld_add_file(s1, libs[i]);
3435 }
3436 }
3437 lib_parse_error:
3438 dynarray_reset(&libs, &nblibs);
3439 return ret;
3440 }
3441
3442 /* interpret a subset of GNU ldscripts to handle the dummy libc.so
3443 files */
3444 ST_FUNC int tcc_load_ldscript(TCCState *s1)
3445 {
3446 char cmd[64];
3447 char filename[1024];
3448 int t, ret;
3449
3450 ch = file->buf_ptr[0];
3451 ch = handle_eob();
3452 for(;;) {
3453 t = ld_next(s1, cmd, sizeof(cmd));
3454 if (t == LD_TOK_EOF)
3455 return 0;
3456 else if (t != LD_TOK_NAME)
3457 return -1;
3458 if (!strcmp(cmd, "INPUT") ||
3459 !strcmp(cmd, "GROUP")) {
3460 ret = ld_add_file_list(s1, cmd, 0);
3461 if (ret)
3462 return ret;
3463 } else if (!strcmp(cmd, "OUTPUT_FORMAT") ||
3464 !strcmp(cmd, "TARGET")) {
3465 /* ignore some commands */
3466 t = ld_next(s1, cmd, sizeof(cmd));
3467 if (t != '(')
3468 expect("(");
3469 for(;;) {
3470 t = ld_next(s1, filename, sizeof(filename));
3471 if (t == LD_TOK_EOF) {
3472 tcc_error_noabort("unexpected end of file");
3473 return -1;
3474 } else if (t == ')') {
3475 break;
3476 }
3477 }
3478 } else {
3479 return -1;
3480 }
3481 }
3482 return 0;
3483 }
3484 #endif /* !TCC_TARGET_PE */
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