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tcc_add_runtime() for a CONFIG_USE_LIBGCC case: reducing a complexity
[tinycc.git] / tccelf.c
blob648422e209ab8e206ca1d2df64bef794b3d2a195
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", s1->tcc_lib_path, filename);
1579 return tcc_add_file(s1, buf);
1580 }
1581
1582 /* add tcc runtime libraries */
1583 ST_FUNC void tcc_add_runtime(TCCState *s1)
1584 {
1585 /* add libc */
1586 if (!s1->nostdlib) {
1587 tcc_add_library(s1, "c");
1588 #ifdef CONFIG_USE_LIBGCC
1589 if (!s1->static_link) {
1590 tcc_add_file(s1, TCC_LIBGCC);
1591 }
1592 #endif
1593 tcc_add_support(s1, "libtcc1.a");
1594 }
1595
1596 /* tcc_add_bcheck tries to relocate a call to __bound_init in _init so
1597 libtcc1.a must be loaded before for __bound_init to be defined and
1598 crtn.o must be loaded after to not finalize _init too early. */
1599 tcc_add_bcheck(s1);
1600
1601 if (!s1->nostdlib) {
1602 /* add crt end if not memory output */
1603 if (s1->output_type != TCC_OUTPUT_MEMORY)
1604 tcc_add_crt(s1, "crtn.o");
1605 }
1606 }
1607
1608 /* add various standard linker symbols (must be done after the
1609 sections are filled (for example after allocating common
1610 symbols)) */
1611 ST_FUNC void tcc_add_linker_symbols(TCCState *s1)
1612 {
1613 char buf[1024];
1614 int i;
1615 Section *s;
1616
1617 add_elf_sym(symtab_section,
1618 text_section->data_offset, 0,
1619 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1620 text_section->sh_num, "_etext");
1621 add_elf_sym(symtab_section,
1622 data_section->data_offset, 0,
1623 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1624 data_section->sh_num, "_edata");
1625 add_elf_sym(symtab_section,
1626 bss_section->data_offset, 0,
1627 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1628 bss_section->sh_num, "_end");
1629 /* horrible new standard ldscript defines */
1630 add_init_array_defines(s1, ".preinit_array");
1631 add_init_array_defines(s1, ".init_array");
1632 add_init_array_defines(s1, ".fini_array");
1633
1634 /* add start and stop symbols for sections whose name can be
1635 expressed in C */
1636 for(i = 1; i < s1->nb_sections; i++) {
1637 s = s1->sections[i];
1638 if (s->sh_type == SHT_PROGBITS &&
1639 (s->sh_flags & SHF_ALLOC)) {
1640 const char *p;
1641 int ch;
1642
1643 /* check if section name can be expressed in C */
1644 p = s->name;
1645 for(;;) {
1646 ch = *p;
1647 if (!ch)
1648 break;
1649 if (!isid(ch) && !isnum(ch))
1650 goto next_sec;
1651 p++;
1652 }
1653 snprintf(buf, sizeof(buf), "__start_%s", s->name);
1654 add_elf_sym(symtab_section,
1655 0, 0,
1656 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1657 s->sh_num, buf);
1658 snprintf(buf, sizeof(buf), "__stop_%s", s->name);
1659 add_elf_sym(symtab_section,
1660 s->data_offset, 0,
1661 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1662 s->sh_num, buf);
1663 }
1664 next_sec: ;
1665 }
1666 }
1667
1668 static void tcc_output_binary(TCCState *s1, FILE *f,
1669 const int *sec_order)
1670 {
1671 Section *s;
1672 int i, offset, size;
1673
1674 offset = 0;
1675 for(i=1;i<s1->nb_sections;i++) {
1676 s = s1->sections[sec_order[i]];
1677 if (s->sh_type != SHT_NOBITS &&
1678 (s->sh_flags & SHF_ALLOC)) {
1679 while (offset < s->sh_offset) {
1680 fputc(0, f);
1681 offset++;
1682 }
1683 size = s->sh_size;
1684 fwrite(s->data, 1, size, f);
1685 offset += size;
1686 }
1687 }
1688 }
1689
1690 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1691 #define HAVE_PHDR 1
1692 #define EXTRA_RELITEMS 14
1693
1694 /* move the relocation value from .dynsym to .got */
1695 void patch_dynsym_undef(TCCState *s1, Section *s)
1696 {
1697 uint32_t *gotd = (void *)s1->got->data;
1698 ElfW(Sym) *sym;
1699
1700 gotd += 3; /* dummy entries in .got */
1701 /* relocate symbols in .dynsym */
1702 for_each_elem(s, 1, sym, ElfW(Sym)) {
1703 if (sym->st_shndx == SHN_UNDEF) {
1704 *gotd++ = sym->st_value + 6; /* XXX 6 is magic ? */
1705 sym->st_value = 0;
1706 }
1707 }
1708 }
1709 #else
1710 #define HAVE_PHDR 1
1711 #define EXTRA_RELITEMS 9
1712
1713 /* zero plt offsets of weak symbols in .dynsym */
1714 void patch_dynsym_undef(TCCState *s1, Section *s)
1715 {
1716 ElfW(Sym) *sym;
1717
1718 for_each_elem(s, 1, sym, ElfW(Sym))
1719 if (sym->st_shndx == SHN_UNDEF && ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
1720 sym->st_value = 0;
1721 }
1722 #endif
1723
1724 ST_FUNC void fill_got_entry(TCCState *s1, ElfW_Rel *rel)
1725 {
1726 int sym_index = ELFW(R_SYM) (rel->r_info);
1727 ElfW(Sym) *sym = &((ElfW(Sym) *) symtab_section->data)[sym_index];
1728 unsigned long offset;
1729
1730 if (sym_index >= s1->nb_sym_attrs)
1731 return;
1732 offset = s1->sym_attrs[sym_index].got_offset;
1733 section_reserve(s1->got, offset + PTR_SIZE);
1734 #ifdef TCC_TARGET_X86_64
1735 /* only works for x86-64 */
1736 put32(s1->got->data + offset + 4, sym->st_value >> 32);
1737 #endif
1738 put32(s1->got->data + offset, sym->st_value & 0xffffffff);
1739 }
1740
1741 /* Perform relocation to GOT or PLT entries */
1742 ST_FUNC void fill_got(TCCState *s1)
1743 {
1744 Section *s;
1745 ElfW_Rel *rel;
1746 int i;
1747
1748 for(i = 1; i < s1->nb_sections; i++) {
1749 s = s1->sections[i];
1750 if (s->sh_type != SHT_RELX)
1751 continue;
1752 /* no need to handle got relocations */
1753 if (s->link != symtab_section)
1754 continue;
1755 for_each_elem(s, 0, rel, ElfW_Rel) {
1756 switch (ELFW(R_TYPE) (rel->r_info)) {
1757 case R_X86_64_GOT32:
1758 case R_X86_64_GOTPCREL:
1759 case R_X86_64_PLT32:
1760 fill_got_entry(s1, rel);
1761 break;
1762 }
1763 }
1764 }
1765 }
1766
1767 /* Bind symbols of executable: resolve undefined symbols from exported symbols
1768 in shared libraries and export non local defined symbols to shared libraries
1769 if -rdynamic switch was given on command line */
1770 static void bind_exe_dynsyms(TCCState *s1)
1771 {
1772 const char *name;
1773 int sym_index, index;
1774 ElfW(Sym) *sym, *esym;
1775 int type;
1776
1777 /* Resolve undefined symbols from dynamic symbols. When there is a match:
1778 - if STT_FUNC or STT_GNU_IFUNC symbol -> add it in PLT
1779 - if STT_OBJECT symbol -> add it in .bss section with suitable reloc */
1780 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
1781 if (sym->st_shndx == SHN_UNDEF) {
1782 name = (char *) symtab_section->link->data + sym->st_name;
1783 sym_index = find_elf_sym(s1->dynsymtab_section, name);
1784 if (sym_index) {
1785 esym = &((ElfW(Sym) *)s1->dynsymtab_section->data)[sym_index];
1786 type = ELFW(ST_TYPE)(esym->st_info);
1787 if ((type == STT_FUNC) || (type == STT_GNU_IFUNC)) {
1788 /* Indirect functions shall have STT_FUNC type in executable
1789 * dynsym section. Indeed, a dlsym call following a lazy
1790 * resolution would pick the symbol value from the
1791 * executable dynsym entry which would contain the address
1792 * of the function wanted by the caller of dlsym instead of
1793 * the address of the function that would return that
1794 * address */
1795 put_got_entry(s1, R_JMP_SLOT, esym->st_size,
1796 ELFW(ST_INFO)(STB_GLOBAL,STT_FUNC),
1797 sym - (ElfW(Sym) *)symtab_section->data);
1798 } else if (type == STT_OBJECT) {
1799 unsigned long offset;
1800 ElfW(Sym) *dynsym;
1801 offset = bss_section->data_offset;
1802 /* XXX: which alignment ? */
1803 offset = (offset + 16 - 1) & -16;
1804 index = put_elf_sym(s1->dynsym, offset, esym->st_size,
1805 esym->st_info, 0, bss_section->sh_num,
1806 name);
1807 /* Ensure R_COPY works for weak symbol aliases */
1808 if (ELFW(ST_BIND)(esym->st_info) == STB_WEAK) {
1809 for_each_elem(s1->dynsymtab_section, 1, dynsym, ElfW(Sym)) {
1810 if ((dynsym->st_value == esym->st_value)
1811 && (ELFW(ST_BIND)(dynsym->st_info) == STB_GLOBAL)) {
1812 char *dynname = (char *) s1->dynsymtab_section->link->data
1813 + dynsym->st_name;
1814 put_elf_sym(s1->dynsym, offset, dynsym->st_size,
1815 dynsym->st_info, 0,
1816 bss_section->sh_num, dynname);
1817 break;
1818 }
1819 }
1820 }
1821 put_elf_reloc(s1->dynsym, bss_section,
1822 offset, R_COPY, index);
1823 offset += esym->st_size;
1824 bss_section->data_offset = offset;
1825 }
1826 } else {
1827 /* STB_WEAK undefined symbols are accepted */
1828 /* XXX: _fp_hw seems to be part of the ABI, so we ignore it */
1829 if (ELFW(ST_BIND)(sym->st_info) == STB_WEAK ||
1830 !strcmp(name, "_fp_hw")) {
1831 } else {
1832 tcc_error_noabort("undefined symbol '%s'", name);
1833 }
1834 }
1835 } else if (s1->rdynamic && ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
1836 /* if -rdynamic option, then export all non local symbols */
1837 name = (char *) symtab_section->link->data + sym->st_name;
1838 put_elf_sym(s1->dynsym, sym->st_value, sym->st_size, sym->st_info,
1839 0, sym->st_shndx, name);
1840 }
1841 }
1842 }
1843
1844 /* Bind symbols of libraries: export non local symbols of executable that
1845 resolve undefined symbols of shared libraries */
1846 static void bind_libs_dynsyms(TCCState *s1)
1847 {
1848 const char *name;
1849 int sym_index;
1850 ElfW(Sym) *sym, *esym;
1851
1852 /* now look at unresolved dynamic symbols and export
1853 corresponding symbol */
1854 for_each_elem(s1->dynsymtab_section, 1, esym, ElfW(Sym)) {
1855 if (esym->st_shndx == SHN_UNDEF) {
1856 name = (char *) s1->dynsymtab_section->link->data + esym->st_name;
1857 sym_index = find_elf_sym(symtab_section, name);
1858 if (sym_index) {
1859 /* XXX: avoid adding a symbol if already present because of
1860 -rdynamic ? */
1861 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1862 put_elf_sym(s1->dynsym, sym->st_value, sym->st_size,
1863 sym->st_info, 0, sym->st_shndx, name);
1864 } else {
1865 /* weak symbols can stay undefined */
1866 if (ELFW(ST_BIND)(esym->st_info) != STB_WEAK)
1867 tcc_warning("undefined dynamic symbol '%s'", name);
1868 }
1869 }
1870 }
1871 }
1872
1873 /* Export all non local symbols (for shared libraries) */
1874 static void export_global_syms(TCCState *s1)
1875 {
1876 int nb_syms, dynindex, index;
1877 const char *name;
1878 ElfW(Sym) *sym;
1879
1880 nb_syms = symtab_section->data_offset / sizeof(ElfW(Sym));
1881 s1->symtab_to_dynsym = tcc_mallocz(sizeof(int) * nb_syms);
1882 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
1883 if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
1884 name = (char *) symtab_section->link->data + sym->st_name;
1885 dynindex = put_elf_sym(s1->dynsym, sym->st_value, sym->st_size,
1886 sym->st_info, 0, sym->st_shndx, name);
1887 index = sym - (ElfW(Sym) *) symtab_section->data;
1888 s1->symtab_to_dynsym[index] = dynindex;
1889 }
1890 }
1891 }
1892
1893 /* relocate the PLT: compute addresses and offsets in the PLT now that final
1894 address for PLT and GOT are known (see fill_program_header) */
1895 ST_FUNC void relocate_plt(TCCState *s1)
1896 {
1897 uint8_t *p, *p_end;
1898
1899 if (!s1->plt)
1900 return;
1901
1902 p = s1->plt->data;
1903 p_end = p + s1->plt->data_offset;
1904 if (p < p_end) {
1905 #if defined(TCC_TARGET_I386)
1906 put32(p + 2, get32(p + 2) + s1->got->sh_addr);
1907 put32(p + 8, get32(p + 8) + s1->got->sh_addr);
1908 p += 16;
1909 while (p < p_end) {
1910 put32(p + 2, get32(p + 2) + s1->got->sh_addr);
1911 p += 16;
1912 }
1913 #elif defined(TCC_TARGET_X86_64)
1914 int x = s1->got->sh_addr - s1->plt->sh_addr - 6;
1915 put32(p + 2, get32(p + 2) + x);
1916 put32(p + 8, get32(p + 8) + x - 6);
1917 p += 16;
1918 while (p < p_end) {
1919 put32(p + 2, get32(p + 2) + x + s1->plt->data - p);
1920 p += 16;
1921 }
1922 #elif defined(TCC_TARGET_ARM)
1923 int x;
1924 x=s1->got->sh_addr - s1->plt->sh_addr - 12;
1925 p += 16;
1926 while (p < p_end) {
1927 if (get32(p) == 0x46c04778) /* PLT Thumb stub present */
1928 p += 4;
1929 put32(p + 12, x + get32(p + 12) + s1->plt->data - p);
1930 p += 16;
1931 }
1932 #elif defined(TCC_TARGET_ARM64)
1933 uint64_t plt = s1->plt->sh_addr;
1934 uint64_t got = s1->got->sh_addr;
1935 uint64_t off = (got >> 12) - (plt >> 12);
1936 if ((off + ((uint32_t)1 << 20)) >> 21)
1937 tcc_error("Failed relocating PLT (off=0x%lx, got=0x%lx, plt=0x%lx)", off, got, plt);
1938 put32(p, 0xa9bf7bf0); // stp x16,x30,[sp,#-16]!
1939 put32(p + 4, (0x90000010 | // adrp x16,...
1940 (off & 0x1ffffc) << 3 | (off & 3) << 29));
1941 put32(p + 8, (0xf9400211 | // ldr x17,[x16,#...]
1942 (got & 0xff8) << 7));
1943 put32(p + 12, (0x91000210 | // add x16,x16,#...
1944 (got & 0xfff) << 10));
1945 put32(p + 16, 0xd61f0220); // br x17
1946 put32(p + 20, 0xd503201f); // nop
1947 put32(p + 24, 0xd503201f); // nop
1948 put32(p + 28, 0xd503201f); // nop
1949 p += 32;
1950 while (p < p_end) {
1951 uint64_t pc = plt + (p - s1->plt->data);
1952 uint64_t addr = got +
1953 (get32(p) | (uint64_t)get32(p + 4) << 32);
1954 uint32_t off = (addr >> 12) - (pc >> 12);
1955 if ((off + ((uint32_t)1 << 20)) >> 21)
1956 tcc_error("Failed relocating PLT (off=0x%lx, addr=0x%lx, pc=0x%lx)", off, addr, pc);
1957 put32(p, (0x90000010 | // adrp x16,...
1958 (off & 0x1ffffc) << 3 | (off & 3) << 29));
1959 put32(p + 4, (0xf9400211 | // ldr x17,[x16,#...]
1960 (addr & 0xff8) << 7));
1961 put32(p + 8, (0x91000210 | // add x16,x16,#...
1962 (addr & 0xfff) << 10));
1963 put32(p + 12, 0xd61f0220); // br x17
1964 p += 16;
1965 }
1966 #elif defined(TCC_TARGET_C67)
1967 /* XXX: TODO */
1968 #else
1969 #error unsupported CPU
1970 #endif
1971 }
1972 }
1973
1974 /* Allocate strings for section names and decide if an unallocated section
1975 should be output.
1976
1977 NOTE: the strsec section comes last, so its size is also correct ! */
1978 static void alloc_sec_names(TCCState *s1, int file_type, Section *strsec)
1979 {
1980 int i;
1981 Section *s;
1982
1983 /* Allocate strings for section names */
1984 for(i = 1; i < s1->nb_sections; i++) {
1985 s = s1->sections[i];
1986 s->sh_name = put_elf_str(strsec, s->name);
1987 /* when generating a DLL, we include relocations but we may
1988 patch them */
1989 if (file_type == TCC_OUTPUT_DLL &&
1990 s->sh_type == SHT_RELX &&
1991 !(s->sh_flags & SHF_ALLOC)) {
1992 /* gr: avoid bogus relocs for empty (debug) sections */
1993 if (s1->sections[s->sh_info]->sh_flags & SHF_ALLOC)
1994 prepare_dynamic_rel(s1, s);
1995 else if (s1->do_debug)
1996 s->sh_size = s->data_offset;
1997 } else if (s1->do_debug ||
1998 file_type == TCC_OUTPUT_OBJ ||
1999 (s->sh_flags & SHF_ALLOC) ||
2000 i == (s1->nb_sections - 1)) {
2001 /* we output all sections if debug or object file */
2002 s->sh_size = s->data_offset;
2003 }
2004 }
2005 }
2006
2007 /* Info to be copied in dynamic section */
2008 struct dyn_inf {
2009 Section *dynamic;
2010 Section *dynstr;
2011 unsigned long dyn_rel_off;
2012 addr_t rel_addr;
2013 addr_t rel_size;
2014 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2015 addr_t bss_addr;
2016 addr_t bss_size;
2017 #endif
2018 };
2019
2020 /* Assign sections to segments and decide how are sections laid out when loaded
2021 in memory. This function also fills corresponding program headers. */
2022 static int layout_sections(TCCState *s1, ElfW(Phdr) *phdr, int phnum,
2023 Section *interp, Section* strsec,
2024 struct dyn_inf *dyninf, int *sec_order)
2025 {
2026 int i, j, k, file_type, sh_order_index, file_offset;
2027 unsigned long s_align;
2028 long long tmp;
2029 addr_t addr;
2030 ElfW(Phdr) *ph;
2031 Section *s;
2032
2033 file_type = s1->output_type;
2034 sh_order_index = 1;
2035 file_offset = 0;
2036 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF)
2037 file_offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr));
2038 s_align = ELF_PAGE_SIZE;
2039 if (s1->section_align)
2040 s_align = s1->section_align;
2041
2042 if (phnum > 0) {
2043 if (s1->has_text_addr) {
2044 int a_offset, p_offset;
2045 addr = s1->text_addr;
2046 /* we ensure that (addr % ELF_PAGE_SIZE) == file_offset %
2047 ELF_PAGE_SIZE */
2048 a_offset = (int) (addr & (s_align - 1));
2049 p_offset = file_offset & (s_align - 1);
2050 if (a_offset < p_offset)
2051 a_offset += s_align;
2052 file_offset += (a_offset - p_offset);
2053 } else {
2054 if (file_type == TCC_OUTPUT_DLL)
2055 addr = 0;
2056 else
2057 addr = ELF_START_ADDR;
2058 /* compute address after headers */
2059 addr += (file_offset & (s_align - 1));
2060 }
2061
2062 ph = &phdr[0];
2063 /* Leave one program headers for the program interpreter and one for
2064 the program header table itself if needed. These are done later as
2065 they require section layout to be done first. */
2066 if (interp)
2067 ph += 1 + HAVE_PHDR;
2068
2069 /* dynamic relocation table information, for .dynamic section */
2070 dyninf->rel_addr = dyninf->rel_size = 0;
2071 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2072 dyninf->bss_addr = dyninf->bss_size = 0;
2073 #endif
2074
2075 for(j = 0; j < 2; j++) {
2076 ph->p_type = PT_LOAD;
2077 if (j == 0)
2078 ph->p_flags = PF_R | PF_X;
2079 else
2080 ph->p_flags = PF_R | PF_W;
2081 ph->p_align = s_align;
2082
2083 /* Decide the layout of sections loaded in memory. This must
2084 be done before program headers are filled since they contain
2085 info about the layout. We do the following ordering: interp,
2086 symbol tables, relocations, progbits, nobits */
2087 /* XXX: do faster and simpler sorting */
2088 for(k = 0; k < 5; k++) {
2089 for(i = 1; i < s1->nb_sections; i++) {
2090 s = s1->sections[i];
2091 /* compute if section should be included */
2092 if (j == 0) {
2093 if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) !=
2094 SHF_ALLOC)
2095 continue;
2096 } else {
2097 if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) !=
2098 (SHF_ALLOC | SHF_WRITE))
2099 continue;
2100 }
2101 if (s == interp) {
2102 if (k != 0)
2103 continue;
2104 } else if (s->sh_type == SHT_DYNSYM ||
2105 s->sh_type == SHT_STRTAB ||
2106 s->sh_type == SHT_HASH) {
2107 if (k != 1)
2108 continue;
2109 } else if (s->sh_type == SHT_RELX) {
2110 if (k != 2)
2111 continue;
2112 } else if (s->sh_type == SHT_NOBITS) {
2113 if (k != 4)
2114 continue;
2115 } else {
2116 if (k != 3)
2117 continue;
2118 }
2119 sec_order[sh_order_index++] = i;
2120
2121 /* section matches: we align it and add its size */
2122 tmp = addr;
2123 addr = (addr + s->sh_addralign - 1) &
2124 ~(s->sh_addralign - 1);
2125 file_offset += (int) ( addr - tmp );
2126 s->sh_offset = file_offset;
2127 s->sh_addr = addr;
2128
2129 /* update program header infos */
2130 if (ph->p_offset == 0) {
2131 ph->p_offset = file_offset;
2132 ph->p_vaddr = addr;
2133 ph->p_paddr = ph->p_vaddr;
2134 }
2135 /* update dynamic relocation infos */
2136 if (s->sh_type == SHT_RELX) {
2137 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2138 if (!strcmp(strsec->data + s->sh_name, ".rel.got")) {
2139 dyninf->rel_addr = addr;
2140 dyninf->rel_size += s->sh_size; /* XXX only first rel. */
2141 }
2142 if (!strcmp(strsec->data + s->sh_name, ".rel.bss")) {
2143 dyninf->bss_addr = addr;
2144 dyninf->bss_size = s->sh_size; /* XXX only first rel. */
2145 }
2146 #else
2147 if (dyninf->rel_size == 0)
2148 dyninf->rel_addr = addr;
2149 dyninf->rel_size += s->sh_size;
2150 #endif
2151 }
2152 addr += s->sh_size;
2153 if (s->sh_type != SHT_NOBITS)
2154 file_offset += s->sh_size;
2155 }
2156 }
2157 if (j == 0) {
2158 /* Make the first PT_LOAD segment include the program
2159 headers itself (and the ELF header as well), it'll
2160 come out with same memory use but will make various
2161 tools like binutils strip work better. */
2162 ph->p_offset &= ~(ph->p_align - 1);
2163 ph->p_vaddr &= ~(ph->p_align - 1);
2164 ph->p_paddr &= ~(ph->p_align - 1);
2165 }
2166 ph->p_filesz = file_offset - ph->p_offset;
2167 ph->p_memsz = addr - ph->p_vaddr;
2168 ph++;
2169 if (j == 0) {
2170 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF) {
2171 /* if in the middle of a page, we duplicate the page in
2172 memory so that one copy is RX and the other is RW */
2173 if ((addr & (s_align - 1)) != 0)
2174 addr += s_align;
2175 } else {
2176 addr = (addr + s_align - 1) & ~(s_align - 1);
2177 file_offset = (file_offset + s_align - 1) & ~(s_align - 1);
2178 }
2179 }
2180 }
2181 }
2182
2183 /* all other sections come after */
2184 for(i = 1; i < s1->nb_sections; i++) {
2185 s = s1->sections[i];
2186 if (phnum > 0 && (s->sh_flags & SHF_ALLOC))
2187 continue;
2188 sec_order[sh_order_index++] = i;
2189
2190 file_offset = (file_offset + s->sh_addralign - 1) &
2191 ~(s->sh_addralign - 1);
2192 s->sh_offset = file_offset;
2193 if (s->sh_type != SHT_NOBITS)
2194 file_offset += s->sh_size;
2195 }
2196
2197 return file_offset;
2198 }
2199
2200 static void fill_unloadable_phdr(ElfW(Phdr) *phdr, int phnum, Section *interp,
2201 Section *dynamic)
2202 {
2203 ElfW(Phdr) *ph;
2204
2205 /* if interpreter, then add corresponding program header */
2206 if (interp) {
2207 ph = &phdr[0];
2208
2209 if (HAVE_PHDR)
2210 {
2211 int len = phnum * sizeof(ElfW(Phdr));
2212
2213 ph->p_type = PT_PHDR;
2214 ph->p_offset = sizeof(ElfW(Ehdr));
2215 ph->p_vaddr = interp->sh_addr - len;
2216 ph->p_paddr = ph->p_vaddr;
2217 ph->p_filesz = ph->p_memsz = len;
2218 ph->p_flags = PF_R | PF_X;
2219 ph->p_align = 4; /* interp->sh_addralign; */
2220 ph++;
2221 }
2222
2223 ph->p_type = PT_INTERP;
2224 ph->p_offset = interp->sh_offset;
2225 ph->p_vaddr = interp->sh_addr;
2226 ph->p_paddr = ph->p_vaddr;
2227 ph->p_filesz = interp->sh_size;
2228 ph->p_memsz = interp->sh_size;
2229 ph->p_flags = PF_R;
2230 ph->p_align = interp->sh_addralign;
2231 }
2232
2233 /* if dynamic section, then add corresponding program header */
2234 if (dynamic) {
2235 ph = &phdr[phnum - 1];
2236
2237 ph->p_type = PT_DYNAMIC;
2238 ph->p_offset = dynamic->sh_offset;
2239 ph->p_vaddr = dynamic->sh_addr;
2240 ph->p_paddr = ph->p_vaddr;
2241 ph->p_filesz = dynamic->sh_size;
2242 ph->p_memsz = dynamic->sh_size;
2243 ph->p_flags = PF_R | PF_W;
2244 ph->p_align = dynamic->sh_addralign;
2245 }
2246 }
2247
2248 /* Fill the dynamic section with tags describing the address and size of
2249 sections */
2250 static void fill_dynamic(TCCState *s1, struct dyn_inf *dyninf)
2251 {
2252 Section *dynamic;
2253
2254 dynamic = dyninf->dynamic;
2255
2256 /* put dynamic section entries */
2257 dynamic->data_offset = dyninf->dyn_rel_off;
2258 put_dt(dynamic, DT_HASH, s1->dynsym->hash->sh_addr);
2259 put_dt(dynamic, DT_STRTAB, dyninf->dynstr->sh_addr);
2260 put_dt(dynamic, DT_SYMTAB, s1->dynsym->sh_addr);
2261 put_dt(dynamic, DT_STRSZ, dyninf->dynstr->data_offset);
2262 put_dt(dynamic, DT_SYMENT, sizeof(ElfW(Sym)));
2263 #if defined(TCC_TARGET_ARM64) || defined(TCC_TARGET_X86_64)
2264 put_dt(dynamic, DT_RELA, dyninf->rel_addr);
2265 put_dt(dynamic, DT_RELASZ, dyninf->rel_size);
2266 put_dt(dynamic, DT_RELAENT, sizeof(ElfW_Rel));
2267 #else
2268 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2269 put_dt(dynamic, DT_PLTGOT, s1->got->sh_addr);
2270 put_dt(dynamic, DT_PLTRELSZ, dyninf->rel_size);
2271 put_dt(dynamic, DT_JMPREL, dyninf->rel_addr);
2272 put_dt(dynamic, DT_PLTREL, DT_REL);
2273 put_dt(dynamic, DT_REL, dyninf->bss_addr);
2274 put_dt(dynamic, DT_RELSZ, dyninf->bss_size);
2275 #else
2276 put_dt(dynamic, DT_REL, dyninf->rel_addr);
2277 put_dt(dynamic, DT_RELSZ, dyninf->rel_size);
2278 put_dt(dynamic, DT_RELENT, sizeof(ElfW_Rel));
2279 #endif
2280 #endif
2281 if (s1->do_debug)
2282 put_dt(dynamic, DT_DEBUG, 0);
2283 put_dt(dynamic, DT_NULL, 0);
2284 }
2285
2286 /* Relocate remaining sections and symbols (that is those not related to
2287 dynamic linking) */
2288 static int final_sections_reloc(TCCState *s1)
2289 {
2290 int i;
2291 Section *s;
2292
2293 relocate_syms(s1, 0);
2294
2295 if (s1->nb_errors != 0)
2296 return -1;
2297
2298 /* relocate sections */
2299 /* XXX: ignore sections with allocated relocations ? */
2300 for(i = 1; i < s1->nb_sections; i++) {
2301 s = s1->sections[i];
2302 if (s->reloc && s != s1->got && (s->sh_flags & SHF_ALLOC)) //gr
2303 relocate_section(s1, s);
2304 }
2305
2306 /* relocate relocation entries if the relocation tables are
2307 allocated in the executable */
2308 for(i = 1; i < s1->nb_sections; i++) {
2309 s = s1->sections[i];
2310 if ((s->sh_flags & SHF_ALLOC) &&
2311 s->sh_type == SHT_RELX) {
2312 relocate_rel(s1, s);
2313 }
2314 }
2315 return 0;
2316 }
2317
2318 /* Create an ELF file on disk.
2319 This function handle ELF specific layout requirements */
2320 static void tcc_output_elf(TCCState *s1, FILE *f, int phnum, ElfW(Phdr) *phdr,
2321 int file_offset, int *sec_order)
2322 {
2323 int i, shnum, offset, size, file_type;
2324 Section *s;
2325 ElfW(Ehdr) ehdr;
2326 ElfW(Shdr) shdr, *sh;
2327
2328 file_type = s1->output_type;
2329 shnum = s1->nb_sections;
2330
2331 memset(&ehdr, 0, sizeof(ehdr));
2332
2333 if (phnum > 0) {
2334 ehdr.e_phentsize = sizeof(ElfW(Phdr));
2335 ehdr.e_phnum = phnum;
2336 ehdr.e_phoff = sizeof(ElfW(Ehdr));
2337 }
2338
2339 /* align to 4 */
2340 file_offset = (file_offset + 3) & -4;
2341
2342 /* fill header */
2343 ehdr.e_ident[0] = ELFMAG0;
2344 ehdr.e_ident[1] = ELFMAG1;
2345 ehdr.e_ident[2] = ELFMAG2;
2346 ehdr.e_ident[3] = ELFMAG3;
2347 ehdr.e_ident[4] = ELFCLASSW;
2348 ehdr.e_ident[5] = ELFDATA2LSB;
2349 ehdr.e_ident[6] = EV_CURRENT;
2350 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2351 ehdr.e_ident[EI_OSABI] = ELFOSABI_FREEBSD;
2352 #endif
2353 #ifdef TCC_TARGET_ARM
2354 #ifdef TCC_ARM_EABI
2355 ehdr.e_ident[EI_OSABI] = 0;
2356 ehdr.e_flags = EF_ARM_EABI_VER4;
2357 if (file_type == TCC_OUTPUT_EXE || file_type == TCC_OUTPUT_DLL)
2358 ehdr.e_flags |= EF_ARM_HASENTRY;
2359 if (s1->float_abi == ARM_HARD_FLOAT)
2360 ehdr.e_flags |= EF_ARM_VFP_FLOAT;
2361 else
2362 ehdr.e_flags |= EF_ARM_SOFT_FLOAT;
2363 #else
2364 ehdr.e_ident[EI_OSABI] = ELFOSABI_ARM;
2365 #endif
2366 #endif
2367 switch(file_type) {
2368 default:
2369 case TCC_OUTPUT_EXE:
2370 ehdr.e_type = ET_EXEC;
2371 ehdr.e_entry = get_elf_sym_addr(s1, "_start", 1);
2372 break;
2373 case TCC_OUTPUT_DLL:
2374 ehdr.e_type = ET_DYN;
2375 ehdr.e_entry = text_section->sh_addr; /* XXX: is it correct ? */
2376 break;
2377 case TCC_OUTPUT_OBJ:
2378 ehdr.e_type = ET_REL;
2379 break;
2380 }
2381 ehdr.e_machine = EM_TCC_TARGET;
2382 ehdr.e_version = EV_CURRENT;
2383 ehdr.e_shoff = file_offset;
2384 ehdr.e_ehsize = sizeof(ElfW(Ehdr));
2385 ehdr.e_shentsize = sizeof(ElfW(Shdr));
2386 ehdr.e_shnum = shnum;
2387 ehdr.e_shstrndx = shnum - 1;
2388
2389 fwrite(&ehdr, 1, sizeof(ElfW(Ehdr)), f);
2390 fwrite(phdr, 1, phnum * sizeof(ElfW(Phdr)), f);
2391 offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr));
2392
2393 sort_syms(s1, symtab_section);
2394 for(i = 1; i < s1->nb_sections; i++) {
2395 s = s1->sections[sec_order[i]];
2396 if (s->sh_type != SHT_NOBITS) {
2397 if (s->sh_type == SHT_DYNSYM)
2398 patch_dynsym_undef(s1, s);
2399 while (offset < s->sh_offset) {
2400 fputc(0, f);
2401 offset++;
2402 }
2403 size = s->sh_size;
2404 fwrite(s->data, 1, size, f);
2405 offset += size;
2406 }
2407 }
2408
2409 /* output section headers */
2410 while (offset < ehdr.e_shoff) {
2411 fputc(0, f);
2412 offset++;
2413 }
2414
2415 for(i = 0; i < s1->nb_sections; i++) {
2416 sh = &shdr;
2417 memset(sh, 0, sizeof(ElfW(Shdr)));
2418 s = s1->sections[i];
2419 if (s) {
2420 sh->sh_name = s->sh_name;
2421 sh->sh_type = s->sh_type;
2422 sh->sh_flags = s->sh_flags;
2423 sh->sh_entsize = s->sh_entsize;
2424 sh->sh_info = s->sh_info;
2425 if (s->link)
2426 sh->sh_link = s->link->sh_num;
2427 sh->sh_addralign = s->sh_addralign;
2428 sh->sh_addr = s->sh_addr;
2429 sh->sh_offset = s->sh_offset;
2430 sh->sh_size = s->sh_size;
2431 }
2432 fwrite(sh, 1, sizeof(ElfW(Shdr)), f);
2433 }
2434 }
2435
2436 /* Write an elf, coff or "binary" file */
2437 static int tcc_write_elf_file(TCCState *s1, const char *filename, int phnum,
2438 ElfW(Phdr) *phdr, int file_offset, int *sec_order)
2439 {
2440 int fd, mode, file_type;
2441 FILE *f;
2442
2443 file_type = s1->output_type;
2444 if (file_type == TCC_OUTPUT_OBJ)
2445 mode = 0666;
2446 else
2447 mode = 0777;
2448 unlink(filename);
2449 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, mode);
2450 if (fd < 0) {
2451 tcc_error_noabort("could not write '%s'", filename);
2452 return -1;
2453 }
2454 f = fdopen(fd, "wb");
2455 if (s1->verbose)
2456 printf("<- %s\n", filename);
2457
2458 #ifdef TCC_TARGET_COFF
2459 if (s1->output_format == TCC_OUTPUT_FORMAT_COFF)
2460 tcc_output_coff(s1, f);
2461 else
2462 #endif
2463 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF)
2464 tcc_output_elf(s1, f, phnum, phdr, file_offset, sec_order);
2465 else
2466 tcc_output_binary(s1, f, sec_order);
2467 fclose(f);
2468
2469 return 0;
2470 }
2471
2472 /* Output an elf, coff or binary file */
2473 /* XXX: suppress unneeded sections */
2474 static int elf_output_file(TCCState *s1, const char *filename)
2475 {
2476 int i, ret, phnum, shnum, file_type, file_offset, *sec_order;
2477 struct dyn_inf dyninf;
2478 ElfW(Phdr) *phdr;
2479 ElfW(Sym) *sym;
2480 Section *strsec, *interp, *dynamic, *dynstr;
2481
2482 file_type = s1->output_type;
2483 s1->nb_errors = 0;
2484
2485 /* if linking, also link in runtime libraries (libc, libgcc, etc.) */
2486 if (file_type != TCC_OUTPUT_OBJ) {
2487 tcc_add_runtime(s1);
2488 }
2489
2490 phdr = NULL;
2491 sec_order = NULL;
2492 interp = dynamic = dynstr = NULL; /* avoid warning */
2493 dyninf.dyn_rel_off = 0; /* avoid warning */
2494
2495 if (file_type != TCC_OUTPUT_OBJ) {
2496 relocate_common_syms();
2497
2498 tcc_add_linker_symbols(s1);
2499
2500 if (!s1->static_link) {
2501 if (file_type == TCC_OUTPUT_EXE) {
2502 char *ptr;
2503 /* allow override the dynamic loader */
2504 const char *elfint = getenv("LD_SO");
2505 if (elfint == NULL)
2506 elfint = DEFAULT_ELFINTERP(s1);
2507 /* add interpreter section only if executable */
2508 interp = new_section(s1, ".interp", SHT_PROGBITS, SHF_ALLOC);
2509 interp->sh_addralign = 1;
2510 ptr = section_ptr_add(interp, 1 + strlen(elfint));
2511 strcpy(ptr, elfint);
2512 }
2513
2514 /* add dynamic symbol table */
2515 s1->dynsym = new_symtab(s1, ".dynsym", SHT_DYNSYM, SHF_ALLOC,
2516 ".dynstr",
2517 ".hash", SHF_ALLOC);
2518 dynstr = s1->dynsym->link;
2519
2520 /* add dynamic section */
2521 dynamic = new_section(s1, ".dynamic", SHT_DYNAMIC,
2522 SHF_ALLOC | SHF_WRITE);
2523 dynamic->link = dynstr;
2524 dynamic->sh_entsize = sizeof(ElfW(Dyn));
2525
2526 build_got(s1);
2527
2528 if (file_type == TCC_OUTPUT_EXE) {
2529 bind_exe_dynsyms(s1);
2530
2531 if (s1->nb_errors) {
2532 ret = -1;
2533 goto the_end;
2534 }
2535
2536 bind_libs_dynsyms(s1);
2537 } else /* shared library case: simply export all global symbols */
2538 export_global_syms(s1);
2539
2540 build_got_entries(s1);
2541
2542 /* add a list of needed dlls */
2543 for(i = 0; i < s1->nb_loaded_dlls; i++) {
2544 DLLReference *dllref = s1->loaded_dlls[i];
2545 if (dllref->level == 0)
2546 put_dt(dynamic, DT_NEEDED, put_elf_str(dynstr, dllref->name));
2547 }
2548
2549 if (s1->rpath)
2550 put_dt(dynamic, DT_RPATH, put_elf_str(dynstr, s1->rpath));
2551
2552 /* XXX: currently, since we do not handle PIC code, we
2553 must relocate the readonly segments */
2554 if (file_type == TCC_OUTPUT_DLL) {
2555 if (s1->soname)
2556 put_dt(dynamic, DT_SONAME, put_elf_str(dynstr, s1->soname));
2557 put_dt(dynamic, DT_TEXTREL, 0);
2558 }
2559
2560 if (s1->symbolic)
2561 put_dt(dynamic, DT_SYMBOLIC, 0);
2562
2563 /* add necessary space for other entries */
2564 dyninf.dyn_rel_off = dynamic->data_offset;
2565 dynamic->data_offset += sizeof(ElfW(Dyn)) * EXTRA_RELITEMS;
2566 } else {
2567 /* still need to build got entries in case of static link */
2568 build_got_entries(s1);
2569 }
2570 }
2571
2572 /* we add a section for symbols */
2573 strsec = new_section(s1, ".shstrtab", SHT_STRTAB, 0);
2574 put_elf_str(strsec, "");
2575
2576 /* compute number of sections */
2577 shnum = s1->nb_sections;
2578
2579 /* this array is used to reorder sections in the output file */
2580 sec_order = tcc_malloc(sizeof(int) * shnum);
2581 sec_order[0] = 0;
2582
2583 /* compute number of program headers */
2584 switch(file_type) {
2585 default:
2586 case TCC_OUTPUT_OBJ:
2587 phnum = 0;
2588 break;
2589 case TCC_OUTPUT_EXE:
2590 if (!s1->static_link)
2591 phnum = 4 + HAVE_PHDR;
2592 else
2593 phnum = 2;
2594 break;
2595 case TCC_OUTPUT_DLL:
2596 phnum = 3;
2597 break;
2598 }
2599
2600 /* Allocate strings for section names */
2601 alloc_sec_names(s1, file_type, strsec);
2602
2603 /* allocate program segment headers */
2604 phdr = tcc_mallocz(phnum * sizeof(ElfW(Phdr)));
2605
2606 /* compute section to program header mapping */
2607 file_offset = layout_sections(s1, phdr, phnum, interp, strsec, &dyninf,
2608 sec_order);
2609
2610 /* Fill remaining program header and finalize relocation related to dynamic
2611 linking. */
2612 if (phnum > 0) {
2613 fill_unloadable_phdr(phdr, phnum, interp, dynamic);
2614 if (dynamic) {
2615 dyninf.dynamic = dynamic;
2616 dyninf.dynstr = dynstr;
2617
2618 fill_dynamic(s1, &dyninf);
2619
2620 /* put in GOT the dynamic section address and relocate PLT */
2621 put32(s1->got->data, dynamic->sh_addr);
2622 if (file_type == TCC_OUTPUT_EXE
2623 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
2624 || file_type == TCC_OUTPUT_DLL
2625 #endif
2626 )
2627 relocate_plt(s1);
2628
2629 /* relocate symbols in .dynsym now that final addresses are known */
2630 for_each_elem(s1->dynsym, 1, sym, ElfW(Sym)) {
2631 if (sym->st_shndx == SHN_UNDEF) {
2632 /* relocate to PLT if symbol corresponds to a PLT entry,
2633 but not if it's a weak symbol */
2634 if (ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
2635 sym->st_value = 0;
2636 else if (sym->st_value)
2637 sym->st_value += s1->plt->sh_addr;
2638 } else if (sym->st_shndx < SHN_LORESERVE) {
2639 /* do symbol relocation */
2640 sym->st_value += s1->sections[sym->st_shndx]->sh_addr;
2641 }
2642 }
2643 }
2644 }
2645
2646 /* if building executable or DLL, then relocate each section
2647 except the GOT which is already relocated */
2648 if (file_type != TCC_OUTPUT_OBJ) {
2649 ret = final_sections_reloc(s1);
2650 if (ret)
2651 goto the_end;
2652 }
2653
2654 /* Perform relocation to GOT or PLT entries */
2655 if (file_type == TCC_OUTPUT_EXE && s1->static_link)
2656 fill_got(s1);
2657
2658 /* Create the ELF file with name 'filename' */
2659 ret = tcc_write_elf_file(s1, filename, phnum, phdr, file_offset, sec_order);
2660 the_end:
2661 tcc_free(s1->symtab_to_dynsym);
2662 tcc_free(sec_order);
2663 tcc_free(phdr);
2664 tcc_free(s1->sym_attrs);
2665 s1->sym_attrs = NULL;
2666 return ret;
2667 }
2668
2669 LIBTCCAPI int tcc_output_file(TCCState *s, const char *filename)
2670 {
2671 int ret;
2672 #ifdef TCC_TARGET_PE
2673 if (s->output_type != TCC_OUTPUT_OBJ) {
2674 ret = pe_output_file(s, filename);
2675 } else
2676 #endif
2677 ret = elf_output_file(s, filename);
2678 return ret;
2679 }
2680
2681 static void *load_data(int fd, unsigned long file_offset, unsigned long size)
2682 {
2683 void *data;
2684
2685 data = tcc_malloc(size);
2686 lseek(fd, file_offset, SEEK_SET);
2687 read(fd, data, size);
2688 return data;
2689 }
2690
2691 typedef struct SectionMergeInfo {
2692 Section *s; /* corresponding existing section */
2693 unsigned long offset; /* offset of the new section in the existing section */
2694 uint8_t new_section; /* true if section 's' was added */
2695 uint8_t link_once; /* true if link once section */
2696 } SectionMergeInfo;
2697
2698 /* load an object file and merge it with current files */
2699 /* XXX: handle correctly stab (debug) info */
2700 ST_FUNC int tcc_load_object_file(TCCState *s1,
2701 int fd, unsigned long file_offset)
2702 {
2703 ElfW(Ehdr) ehdr;
2704 ElfW(Shdr) *shdr, *sh;
2705 int size, i, j, offset, offseti, nb_syms, sym_index, ret;
2706 unsigned char *strsec, *strtab;
2707 int *old_to_new_syms;
2708 char *sh_name, *name;
2709 SectionMergeInfo *sm_table, *sm;
2710 ElfW(Sym) *sym, *symtab;
2711 ElfW_Rel *rel;
2712 Section *s;
2713
2714 int stab_index;
2715 int stabstr_index;
2716
2717 stab_index = stabstr_index = 0;
2718
2719 if (read(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr))
2720 goto fail1;
2721 if (ehdr.e_ident[0] != ELFMAG0 ||
2722 ehdr.e_ident[1] != ELFMAG1 ||
2723 ehdr.e_ident[2] != ELFMAG2 ||
2724 ehdr.e_ident[3] != ELFMAG3)
2725 goto fail1;
2726 /* test if object file */
2727 if (ehdr.e_type != ET_REL)
2728 goto fail1;
2729 /* test CPU specific stuff */
2730 if (ehdr.e_ident[5] != ELFDATA2LSB ||
2731 ehdr.e_machine != EM_TCC_TARGET) {
2732 fail1:
2733 tcc_error_noabort("invalid object file");
2734 return -1;
2735 }
2736 /* read sections */
2737 shdr = load_data(fd, file_offset + ehdr.e_shoff,
2738 sizeof(ElfW(Shdr)) * ehdr.e_shnum);
2739 sm_table = tcc_mallocz(sizeof(SectionMergeInfo) * ehdr.e_shnum);
2740
2741 /* load section names */
2742 sh = &shdr[ehdr.e_shstrndx];
2743 strsec = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2744
2745 /* load symtab and strtab */
2746 old_to_new_syms = NULL;
2747 symtab = NULL;
2748 strtab = NULL;
2749 nb_syms = 0;
2750 for(i = 1; i < ehdr.e_shnum; i++) {
2751 sh = &shdr[i];
2752 if (sh->sh_type == SHT_SYMTAB) {
2753 if (symtab) {
2754 tcc_error_noabort("object must contain only one symtab");
2755 fail:
2756 ret = -1;
2757 goto the_end;
2758 }
2759 nb_syms = sh->sh_size / sizeof(ElfW(Sym));
2760 symtab = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2761 sm_table[i].s = symtab_section;
2762
2763 /* now load strtab */
2764 sh = &shdr[sh->sh_link];
2765 strtab = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2766 }
2767 }
2768
2769 /* now examine each section and try to merge its content with the
2770 ones in memory */
2771 for(i = 1; i < ehdr.e_shnum; i++) {
2772 /* no need to examine section name strtab */
2773 if (i == ehdr.e_shstrndx)
2774 continue;
2775 sh = &shdr[i];
2776 sh_name = (char *) strsec + sh->sh_name;
2777 /* ignore sections types we do not handle */
2778 if (sh->sh_type != SHT_PROGBITS &&
2779 sh->sh_type != SHT_RELX &&
2780 #ifdef TCC_ARM_EABI
2781 sh->sh_type != SHT_ARM_EXIDX &&
2782 #endif
2783 sh->sh_type != SHT_NOBITS &&
2784 sh->sh_type != SHT_PREINIT_ARRAY &&
2785 sh->sh_type != SHT_INIT_ARRAY &&
2786 sh->sh_type != SHT_FINI_ARRAY &&
2787 strcmp(sh_name, ".stabstr")
2788 )
2789 continue;
2790 if (sh->sh_addralign < 1)
2791 sh->sh_addralign = 1;
2792 /* find corresponding section, if any */
2793 for(j = 1; j < s1->nb_sections;j++) {
2794 s = s1->sections[j];
2795 if (!strcmp(s->name, sh_name)) {
2796 if (!strncmp(sh_name, ".gnu.linkonce",
2797 sizeof(".gnu.linkonce") - 1)) {
2798 /* if a 'linkonce' section is already present, we
2799 do not add it again. It is a little tricky as
2800 symbols can still be defined in
2801 it. */
2802 sm_table[i].link_once = 1;
2803 goto next;
2804 } else {
2805 goto found;
2806 }
2807 }
2808 }
2809 /* not found: create new section */
2810 s = new_section(s1, sh_name, sh->sh_type, sh->sh_flags);
2811 /* take as much info as possible from the section. sh_link and
2812 sh_info will be updated later */
2813 s->sh_addralign = sh->sh_addralign;
2814 s->sh_entsize = sh->sh_entsize;
2815 sm_table[i].new_section = 1;
2816 found:
2817 if (sh->sh_type != s->sh_type) {
2818 tcc_error_noabort("invalid section type");
2819 goto fail;
2820 }
2821
2822 /* align start of section */
2823 offset = s->data_offset;
2824
2825 if (0 == strcmp(sh_name, ".stab")) {
2826 stab_index = i;
2827 goto no_align;
2828 }
2829 if (0 == strcmp(sh_name, ".stabstr")) {
2830 stabstr_index = i;
2831 goto no_align;
2832 }
2833
2834 size = sh->sh_addralign - 1;
2835 offset = (offset + size) & ~size;
2836 if (sh->sh_addralign > s->sh_addralign)
2837 s->sh_addralign = sh->sh_addralign;
2838 s->data_offset = offset;
2839 no_align:
2840 sm_table[i].offset = offset;
2841 sm_table[i].s = s;
2842 /* concatenate sections */
2843 size = sh->sh_size;
2844 if (sh->sh_type != SHT_NOBITS) {
2845 unsigned char *ptr;
2846 lseek(fd, file_offset + sh->sh_offset, SEEK_SET);
2847 ptr = section_ptr_add(s, size);
2848 read(fd, ptr, size);
2849 } else {
2850 s->data_offset += size;
2851 }
2852 next: ;
2853 }
2854
2855 /* gr relocate stab strings */
2856 if (stab_index && stabstr_index) {
2857 Stab_Sym *a, *b;
2858 unsigned o;
2859 s = sm_table[stab_index].s;
2860 a = (Stab_Sym *)(s->data + sm_table[stab_index].offset);
2861 b = (Stab_Sym *)(s->data + s->data_offset);
2862 o = sm_table[stabstr_index].offset;
2863 while (a < b)
2864 a->n_strx += o, a++;
2865 }
2866
2867 /* second short pass to update sh_link and sh_info fields of new
2868 sections */
2869 for(i = 1; i < ehdr.e_shnum; i++) {
2870 s = sm_table[i].s;
2871 if (!s || !sm_table[i].new_section)
2872 continue;
2873 sh = &shdr[i];
2874 if (sh->sh_link > 0)
2875 s->link = sm_table[sh->sh_link].s;
2876 if (sh->sh_type == SHT_RELX) {
2877 s->sh_info = sm_table[sh->sh_info].s->sh_num;
2878 /* update backward link */
2879 s1->sections[s->sh_info]->reloc = s;
2880 }
2881 }
2882 sm = sm_table;
2883
2884 /* resolve symbols */
2885 old_to_new_syms = tcc_mallocz(nb_syms * sizeof(int));
2886
2887 sym = symtab + 1;
2888 for(i = 1; i < nb_syms; i++, sym++) {
2889 if (sym->st_shndx != SHN_UNDEF &&
2890 sym->st_shndx < SHN_LORESERVE) {
2891 sm = &sm_table[sym->st_shndx];
2892 if (sm->link_once) {
2893 /* if a symbol is in a link once section, we use the
2894 already defined symbol. It is very important to get
2895 correct relocations */
2896 if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
2897 name = (char *) strtab + sym->st_name;
2898 sym_index = find_elf_sym(symtab_section, name);
2899 if (sym_index)
2900 old_to_new_syms[i] = sym_index;
2901 }
2902 continue;
2903 }
2904 /* if no corresponding section added, no need to add symbol */
2905 if (!sm->s)
2906 continue;
2907 /* convert section number */
2908 sym->st_shndx = sm->s->sh_num;
2909 /* offset value */
2910 sym->st_value += sm->offset;
2911 }
2912 /* add symbol */
2913 name = (char *) strtab + sym->st_name;
2914 sym_index = add_elf_sym(symtab_section, sym->st_value, sym->st_size,
2915 sym->st_info, sym->st_other,
2916 sym->st_shndx, name);
2917 old_to_new_syms[i] = sym_index;
2918 }
2919
2920 /* third pass to patch relocation entries */
2921 for(i = 1; i < ehdr.e_shnum; i++) {
2922 s = sm_table[i].s;
2923 if (!s)
2924 continue;
2925 sh = &shdr[i];
2926 offset = sm_table[i].offset;
2927 switch(s->sh_type) {
2928 case SHT_RELX:
2929 /* take relocation offset information */
2930 offseti = sm_table[sh->sh_info].offset;
2931 for_each_elem(s, (offset / sizeof(*rel)), rel, ElfW_Rel) {
2932 int type;
2933 unsigned sym_index;
2934 /* convert symbol index */
2935 type = ELFW(R_TYPE)(rel->r_info);
2936 sym_index = ELFW(R_SYM)(rel->r_info);
2937 /* NOTE: only one symtab assumed */
2938 if (sym_index >= nb_syms)
2939 goto invalid_reloc;
2940 sym_index = old_to_new_syms[sym_index];
2941 /* ignore link_once in rel section. */
2942 if (!sym_index && !sm->link_once
2943 #ifdef TCC_TARGET_ARM
2944 && type != R_ARM_V4BX
2945 #endif
2946 ) {
2947 invalid_reloc:
2948 tcc_error_noabort("Invalid relocation entry [%2d] '%s' @ %.8x",
2949 i, strsec + sh->sh_name, rel->r_offset);
2950 goto fail;
2951 }
2952 rel->r_info = ELFW(R_INFO)(sym_index, type);
2953 /* offset the relocation offset */
2954 rel->r_offset += offseti;
2955 #ifdef TCC_TARGET_ARM
2956 /* Jumps and branches from a Thumb code to a PLT entry need
2957 special handling since PLT entries are ARM code.
2958 Unconditional bl instructions referencing PLT entries are
2959 handled by converting these instructions into blx
2960 instructions. Other case of instructions referencing a PLT
2961 entry require to add a Thumb stub before the PLT entry to
2962 switch to ARM mode. We set bit plt_thumb_stub of the
2963 attribute of a symbol to indicate such a case. */
2964 if (type == R_ARM_THM_JUMP24)
2965 alloc_sym_attr(s1, sym_index)->plt_thumb_stub = 1;
2966 #endif
2967 }
2968 break;
2969 default:
2970 break;
2971 }
2972 }
2973
2974 ret = 0;
2975 the_end:
2976 tcc_free(symtab);
2977 tcc_free(strtab);
2978 tcc_free(old_to_new_syms);
2979 tcc_free(sm_table);
2980 tcc_free(strsec);
2981 tcc_free(shdr);
2982 return ret;
2983 }
2984
2985 typedef struct ArchiveHeader {
2986 char ar_name[16]; /* name of this member */
2987 char ar_date[12]; /* file mtime */
2988 char ar_uid[6]; /* owner uid; printed as decimal */
2989 char ar_gid[6]; /* owner gid; printed as decimal */
2990 char ar_mode[8]; /* file mode, printed as octal */
2991 char ar_size[10]; /* file size, printed as decimal */
2992 char ar_fmag[2]; /* should contain ARFMAG */
2993 } ArchiveHeader;
2994
2995 static int get_be32(const uint8_t *b)
2996 {
2997 return b[3] | (b[2] << 8) | (b[1] << 16) | (b[0] << 24);
2998 }
2999
3000 /* load only the objects which resolve undefined symbols */
3001 static int tcc_load_alacarte(TCCState *s1, int fd, int size)
3002 {
3003 int i, bound, nsyms, sym_index, off, ret;
3004 uint8_t *data;
3005 const char *ar_names, *p;
3006 const uint8_t *ar_index;
3007 ElfW(Sym) *sym;
3008
3009 data = tcc_malloc(size);
3010 if (read(fd, data, size) != size)
3011 goto fail;
3012 nsyms = get_be32(data);
3013 ar_index = data + 4;
3014 ar_names = (char *) ar_index + nsyms * 4;
3015
3016 do {
3017 bound = 0;
3018 for(p = ar_names, i = 0; i < nsyms; i++, p += strlen(p)+1) {
3019 sym_index = find_elf_sym(symtab_section, p);
3020 if(sym_index) {
3021 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
3022 if(sym->st_shndx == SHN_UNDEF) {
3023 off = get_be32(ar_index + i * 4) + sizeof(ArchiveHeader);
3024 ++bound;
3025 lseek(fd, off, SEEK_SET);
3026 if(tcc_load_object_file(s1, fd, off) < 0) {
3027 fail:
3028 ret = -1;
3029 goto the_end;
3030 }
3031 }
3032 }
3033 }
3034 } while(bound);
3035 ret = 0;
3036 the_end:
3037 tcc_free(data);
3038 return ret;
3039 }
3040
3041 /* load a '.a' file */
3042 ST_FUNC int tcc_load_archive(TCCState *s1, int fd)
3043 {
3044 ArchiveHeader hdr;
3045 char ar_size[11];
3046 char ar_name[17];
3047 char magic[8];
3048 int size, len, i;
3049 unsigned long file_offset;
3050
3051 /* skip magic which was already checked */
3052 read(fd, magic, sizeof(magic));
3053
3054 for(;;) {
3055 len = read(fd, &hdr, sizeof(hdr));
3056 if (len == 0)
3057 break;
3058 if (len != sizeof(hdr)) {
3059 tcc_error_noabort("invalid archive");
3060 return -1;
3061 }
3062 memcpy(ar_size, hdr.ar_size, sizeof(hdr.ar_size));
3063 ar_size[sizeof(hdr.ar_size)] = '\0';
3064 size = strtol(ar_size, NULL, 0);
3065 memcpy(ar_name, hdr.ar_name, sizeof(hdr.ar_name));
3066 for(i = sizeof(hdr.ar_name) - 1; i >= 0; i--) {
3067 if (ar_name[i] != ' ')
3068 break;
3069 }
3070 ar_name[i + 1] = '\0';
3071 file_offset = lseek(fd, 0, SEEK_CUR);
3072 /* align to even */
3073 size = (size + 1) & ~1;
3074 if (!strcmp(ar_name, "/")) {
3075 /* coff symbol table : we handle it */
3076 if(s1->alacarte_link)
3077 return tcc_load_alacarte(s1, fd, size);
3078 } else if (!strcmp(ar_name, "//") ||
3079 !strcmp(ar_name, "__.SYMDEF") ||
3080 !strcmp(ar_name, "__.SYMDEF/") ||
3081 !strcmp(ar_name, "ARFILENAMES/")) {
3082 /* skip symbol table or archive names */
3083 } else {
3084 if (tcc_load_object_file(s1, fd, file_offset) < 0)
3085 return -1;
3086 }
3087 lseek(fd, file_offset + size, SEEK_SET);
3088 }
3089 return 0;
3090 }
3091
3092 #ifndef TCC_TARGET_PE
3093 /* load a DLL and all referenced DLLs. 'level = 0' means that the DLL
3094 is referenced by the user (so it should be added as DT_NEEDED in
3095 the generated ELF file) */
3096 ST_FUNC int tcc_load_dll(TCCState *s1, int fd, const char *filename, int level)
3097 {
3098 ElfW(Ehdr) ehdr;
3099 ElfW(Shdr) *shdr, *sh, *sh1;
3100 int i, j, nb_syms, nb_dts, sym_bind, ret;
3101 ElfW(Sym) *sym, *dynsym;
3102 ElfW(Dyn) *dt, *dynamic;
3103 unsigned char *dynstr;
3104 const char *name, *soname;
3105 DLLReference *dllref;
3106
3107 read(fd, &ehdr, sizeof(ehdr));
3108
3109 /* test CPU specific stuff */
3110 if (ehdr.e_ident[5] != ELFDATA2LSB ||
3111 ehdr.e_machine != EM_TCC_TARGET) {
3112 tcc_error_noabort("bad architecture");
3113 return -1;
3114 }
3115
3116 /* read sections */
3117 shdr = load_data(fd, ehdr.e_shoff, sizeof(ElfW(Shdr)) * ehdr.e_shnum);
3118
3119 /* load dynamic section and dynamic symbols */
3120 nb_syms = 0;
3121 nb_dts = 0;
3122 dynamic = NULL;
3123 dynsym = NULL; /* avoid warning */
3124 dynstr = NULL; /* avoid warning */
3125 for(i = 0, sh = shdr; i < ehdr.e_shnum; i++, sh++) {
3126 switch(sh->sh_type) {
3127 case SHT_DYNAMIC:
3128 nb_dts = sh->sh_size / sizeof(ElfW(Dyn));
3129 dynamic = load_data(fd, sh->sh_offset, sh->sh_size);
3130 break;
3131 case SHT_DYNSYM:
3132 nb_syms = sh->sh_size / sizeof(ElfW(Sym));
3133 dynsym = load_data(fd, sh->sh_offset, sh->sh_size);
3134 sh1 = &shdr[sh->sh_link];
3135 dynstr = load_data(fd, sh1->sh_offset, sh1->sh_size);
3136 break;
3137 default:
3138 break;
3139 }
3140 }
3141
3142 /* compute the real library name */
3143 soname = tcc_basename(filename);
3144
3145 for(i = 0, dt = dynamic; i < nb_dts; i++, dt++) {
3146 if (dt->d_tag == DT_SONAME) {
3147 soname = (char *) dynstr + dt->d_un.d_val;
3148 }
3149 }
3150
3151 /* if the dll is already loaded, do not load it */
3152 for(i = 0; i < s1->nb_loaded_dlls; i++) {
3153 dllref = s1->loaded_dlls[i];
3154 if (!strcmp(soname, dllref->name)) {
3155 /* but update level if needed */
3156 if (level < dllref->level)
3157 dllref->level = level;
3158 ret = 0;
3159 goto the_end;
3160 }
3161 }
3162
3163 /* add the dll and its level */
3164 dllref = tcc_mallocz(sizeof(DLLReference) + strlen(soname));
3165 dllref->level = level;
3166 strcpy(dllref->name, soname);
3167 dynarray_add((void ***)&s1->loaded_dlls, &s1->nb_loaded_dlls, dllref);
3168
3169 /* add dynamic symbols in dynsym_section */
3170 for(i = 1, sym = dynsym + 1; i < nb_syms; i++, sym++) {
3171 sym_bind = ELFW(ST_BIND)(sym->st_info);
3172 if (sym_bind == STB_LOCAL)
3173 continue;
3174 name = (char *) dynstr + sym->st_name;
3175 add_elf_sym(s1->dynsymtab_section, sym->st_value, sym->st_size,
3176 sym->st_info, sym->st_other, sym->st_shndx, name);
3177 }
3178
3179 /* load all referenced DLLs */
3180 for(i = 0, dt = dynamic; i < nb_dts; i++, dt++) {
3181 switch(dt->d_tag) {
3182 case DT_NEEDED:
3183 name = (char *) dynstr + dt->d_un.d_val;
3184 for(j = 0; j < s1->nb_loaded_dlls; j++) {
3185 dllref = s1->loaded_dlls[j];
3186 if (!strcmp(name, dllref->name))
3187 goto already_loaded;
3188 }
3189 if (tcc_add_dll(s1, name, AFF_REFERENCED_DLL) < 0) {
3190 tcc_error_noabort("referenced dll '%s' not found", name);
3191 ret = -1;
3192 goto the_end;
3193 }
3194 already_loaded:
3195 break;
3196 }
3197 }
3198 ret = 0;
3199 the_end:
3200 tcc_free(dynstr);
3201 tcc_free(dynsym);
3202 tcc_free(dynamic);
3203 tcc_free(shdr);
3204 return ret;
3205 }
3206
3207 #define LD_TOK_NAME 256
3208 #define LD_TOK_EOF (-1)
3209
3210 /* return next ld script token */
3211 static int ld_next(TCCState *s1, char *name, int name_size)
3212 {
3213 int c;
3214 char *q;
3215
3216 redo:
3217 switch(ch) {
3218 case ' ':
3219 case '\t':
3220 case '\f':
3221 case '\v':
3222 case '\r':
3223 case '\n':
3224 inp();
3225 goto redo;
3226 case '/':
3227 minp();
3228 if (ch == '*') {
3229 file->buf_ptr = parse_comment(file->buf_ptr);
3230 ch = file->buf_ptr[0];
3231 goto redo;
3232 } else {
3233 q = name;
3234 *q++ = '/';
3235 goto parse_name;
3236 }
3237 break;
3238 /* case 'a' ... 'z': */
3239 case 'a':
3240 case 'b':
3241 case 'c':
3242 case 'd':
3243 case 'e':
3244 case 'f':
3245 case 'g':
3246 case 'h':
3247 case 'i':
3248 case 'j':
3249 case 'k':
3250 case 'l':
3251 case 'm':
3252 case 'n':
3253 case 'o':
3254 case 'p':
3255 case 'q':
3256 case 'r':
3257 case 's':
3258 case 't':
3259 case 'u':
3260 case 'v':
3261 case 'w':
3262 case 'x':
3263 case 'y':
3264 case 'z':
3265 /* case 'A' ... 'z': */
3266 case 'A':
3267 case 'B':
3268 case 'C':
3269 case 'D':
3270 case 'E':
3271 case 'F':
3272 case 'G':
3273 case 'H':
3274 case 'I':
3275 case 'J':
3276 case 'K':
3277 case 'L':
3278 case 'M':
3279 case 'N':
3280 case 'O':
3281 case 'P':
3282 case 'Q':
3283 case 'R':
3284 case 'S':
3285 case 'T':
3286 case 'U':
3287 case 'V':
3288 case 'W':
3289 case 'X':
3290 case 'Y':
3291 case 'Z':
3292 case '_':
3293 case '\\':
3294 case '.':
3295 case '$':
3296 case '~':
3297 q = name;
3298 parse_name:
3299 for(;;) {
3300 if (!((ch >= 'a' && ch <= 'z') ||
3301 (ch >= 'A' && ch <= 'Z') ||
3302 (ch >= '0' && ch <= '9') ||
3303 strchr("/.-_+=$:\\,~", ch)))
3304 break;
3305 if ((q - name) < name_size - 1) {
3306 *q++ = ch;
3307 }
3308 minp();
3309 }
3310 *q = '\0';
3311 c = LD_TOK_NAME;
3312 break;
3313 case CH_EOF:
3314 c = LD_TOK_EOF;
3315 break;
3316 default:
3317 c = ch;
3318 inp();
3319 break;
3320 }
3321 return c;
3322 }
3323
3324 static int ld_add_file(TCCState *s1, const char filename[])
3325 {
3326 int ret;
3327
3328 ret = tcc_add_file_internal(s1, filename, 0);
3329 if (ret)
3330 ret = tcc_add_dll(s1, filename, 0);
3331 return ret;
3332 }
3333
3334 static inline int new_undef_syms(void)
3335 {
3336 int ret = 0;
3337 ret = new_undef_sym;
3338 new_undef_sym = 0;
3339 return ret;
3340 }
3341
3342 static int ld_add_file_list(TCCState *s1, const char *cmd, int as_needed)
3343 {
3344 char filename[1024], libname[1024];
3345 int t, group, nblibs = 0, ret = 0;
3346 char **libs = NULL;
3347
3348 group = !strcmp(cmd, "GROUP");
3349 if (!as_needed)
3350 new_undef_syms();
3351 t = ld_next(s1, filename, sizeof(filename));
3352 if (t != '(')
3353 expect("(");
3354 t = ld_next(s1, filename, sizeof(filename));
3355 for(;;) {
3356 libname[0] = '\0';
3357 if (t == LD_TOK_EOF) {
3358 tcc_error_noabort("unexpected end of file");
3359 ret = -1;
3360 goto lib_parse_error;
3361 } else if (t == ')') {
3362 break;
3363 } else if (t == '-') {
3364 t = ld_next(s1, filename, sizeof(filename));
3365 if ((t != LD_TOK_NAME) || (filename[0] != 'l')) {
3366 tcc_error_noabort("library name expected");
3367 ret = -1;
3368 goto lib_parse_error;
3369 }
3370 pstrcpy(libname, sizeof libname, &filename[1]);
3371 if (s1->static_link) {
3372 snprintf(filename, sizeof filename, "lib%s.a", libname);
3373 } else {
3374 snprintf(filename, sizeof filename, "lib%s.so", libname);
3375 }
3376 } else if (t != LD_TOK_NAME) {
3377 tcc_error_noabort("filename expected");
3378 ret = -1;
3379 goto lib_parse_error;
3380 }
3381 if (!strcmp(filename, "AS_NEEDED")) {
3382 ret = ld_add_file_list(s1, cmd, 1);
3383 if (ret)
3384 goto lib_parse_error;
3385 } else {
3386 /* TODO: Implement AS_NEEDED support. Ignore it for now */
3387 if (!as_needed) {
3388 ret = ld_add_file(s1, filename);
3389 if (ret)
3390 goto lib_parse_error;
3391 if (group) {
3392 /* Add the filename *and* the libname to avoid future conversions */
3393 dynarray_add((void ***) &libs, &nblibs, tcc_strdup(filename));
3394 if (libname[0] != '\0')
3395 dynarray_add((void ***) &libs, &nblibs, tcc_strdup(libname));
3396 }
3397 }
3398 }
3399 t = ld_next(s1, filename, sizeof(filename));
3400 if (t == ',') {
3401 t = ld_next(s1, filename, sizeof(filename));
3402 }
3403 }
3404 if (group && !as_needed) {
3405 while (new_undef_syms()) {
3406 int i;
3407
3408 for (i = 0; i < nblibs; i ++)
3409 ld_add_file(s1, libs[i]);
3410 }
3411 }
3412 lib_parse_error:
3413 dynarray_reset(&libs, &nblibs);
3414 return ret;
3415 }
3416
3417 /* interpret a subset of GNU ldscripts to handle the dummy libc.so
3418 files */
3419 ST_FUNC int tcc_load_ldscript(TCCState *s1)
3420 {
3421 char cmd[64];
3422 char filename[1024];
3423 int t, ret;
3424
3425 ch = file->buf_ptr[0];
3426 ch = handle_eob();
3427 for(;;) {
3428 t = ld_next(s1, cmd, sizeof(cmd));
3429 if (t == LD_TOK_EOF)
3430 return 0;
3431 else if (t != LD_TOK_NAME)
3432 return -1;
3433 if (!strcmp(cmd, "INPUT") ||
3434 !strcmp(cmd, "GROUP")) {
3435 ret = ld_add_file_list(s1, cmd, 0);
3436 if (ret)
3437 return ret;
3438 } else if (!strcmp(cmd, "OUTPUT_FORMAT") ||
3439 !strcmp(cmd, "TARGET")) {
3440 /* ignore some commands */
3441 t = ld_next(s1, cmd, sizeof(cmd));
3442 if (t != '(')
3443 expect("(");
3444 for(;;) {
3445 t = ld_next(s1, filename, sizeof(filename));
3446 if (t == LD_TOK_EOF) {
3447 tcc_error_noabort("unexpected end of file");
3448 return -1;
3449 } else if (t == ')') {
3450 break;
3451 }
3452 }
3453 } else {
3454 return -1;
3455 }
3456 }
3457 return 0;
3458 }
3459 #endif /* !TCC_TARGET_PE */
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