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tccgen.c: Try to make sizeof(!x) work.
[tinycc.git] / tccelf.c
blobffc1079f5409545ac0bccdfe5e241d9a0157e4e0
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... may be -fcommon is needed?", name);
252 }
253 } else {
254 do_patch:
255 esym->st_info = ELFW(ST_INFO)(sym_bind, sym_type);
256 esym->st_shndx = sh_num;
257 new_undef_sym = 1;
258 esym->st_value = value;
259 esym->st_size = size;
260 esym->st_other = other;
261 }
262 } else {
263 do_def:
264 sym_index = put_elf_sym(s, value, size,
265 ELFW(ST_INFO)(sym_bind, sym_type), other,
266 sh_num, name);
267 }
268 return sym_index;
269 }
270
271 /* put relocation */
272 ST_FUNC void put_elf_reloca(Section *symtab, Section *s, unsigned long offset,
273 int type, int symbol, addr_t addend)
274 {
275 char buf[256];
276 Section *sr;
277 ElfW_Rel *rel;
278
279 sr = s->reloc;
280 if (!sr) {
281 /* if no relocation section, create it */
282 snprintf(buf, sizeof(buf), REL_SECTION_FMT, s->name);
283 /* if the symtab is allocated, then we consider the relocation
284 are also */
285 sr = new_section(tcc_state, buf, SHT_RELX, symtab->sh_flags);
286 sr->sh_entsize = sizeof(ElfW_Rel);
287 sr->link = symtab;
288 sr->sh_info = s->sh_num;
289 s->reloc = sr;
290 }
291 rel = section_ptr_add(sr, sizeof(ElfW_Rel));
292 rel->r_offset = offset;
293 rel->r_info = ELFW(R_INFO)(symbol, type);
294 #if defined(TCC_TARGET_ARM64) || defined(TCC_TARGET_X86_64)
295 rel->r_addend = addend;
296 #else
297 if (addend)
298 tcc_error("non-zero addend on REL architecture");
299 #endif
300 }
301
302 ST_FUNC void put_elf_reloc(Section *symtab, Section *s, unsigned long offset,
303 int type, int symbol)
304 {
305 put_elf_reloca(symtab, s, offset, type, symbol, 0);
306 }
307
308 /* put stab debug information */
309
310 ST_FUNC void put_stabs(const char *str, int type, int other, int desc,
311 unsigned long value)
312 {
313 Stab_Sym *sym;
314
315 sym = section_ptr_add(stab_section, sizeof(Stab_Sym));
316 if (str) {
317 sym->n_strx = put_elf_str(stabstr_section, str);
318 } else {
319 sym->n_strx = 0;
320 }
321 sym->n_type = type;
322 sym->n_other = other;
323 sym->n_desc = desc;
324 sym->n_value = value;
325 }
326
327 ST_FUNC void put_stabs_r(const char *str, int type, int other, int desc,
328 unsigned long value, Section *sec, int sym_index)
329 {
330 put_stabs(str, type, other, desc, value);
331 put_elf_reloc(symtab_section, stab_section,
332 stab_section->data_offset - sizeof(unsigned int),
333 R_DATA_32, sym_index);
334 }
335
336 ST_FUNC void put_stabn(int type, int other, int desc, int value)
337 {
338 put_stabs(NULL, type, other, desc, value);
339 }
340
341 ST_FUNC void put_stabd(int type, int other, int desc)
342 {
343 put_stabs(NULL, type, other, desc, 0);
344 }
345
346 /* Browse each elem of type <type> in section <sec> starting at elem <startoff>
347 using variable <elem> */
348 #define for_each_elem(sec, startoff, elem, type) \
349 for (elem = (type *) sec->data + startoff; \
350 elem < (type *) (sec->data + sec->data_offset); elem++)
351
352 /* In an ELF file symbol table, the local symbols must appear below
353 the global and weak ones. Since TCC cannot sort it while generating
354 the code, we must do it after. All the relocation tables are also
355 modified to take into account the symbol table sorting */
356 static void sort_syms(TCCState *s1, Section *s)
357 {
358 int *old_to_new_syms;
359 ElfW(Sym) *new_syms;
360 int nb_syms, i;
361 ElfW(Sym) *p, *q;
362 ElfW_Rel *rel;
363 Section *sr;
364 int type, sym_index;
365
366 nb_syms = s->data_offset / sizeof(ElfW(Sym));
367 new_syms = tcc_malloc(nb_syms * sizeof(ElfW(Sym)));
368 old_to_new_syms = tcc_malloc(nb_syms * sizeof(int));
369
370 /* first pass for local symbols */
371 p = (ElfW(Sym) *)s->data;
372 q = new_syms;
373 for(i = 0; i < nb_syms; i++) {
374 if (ELFW(ST_BIND)(p->st_info) == STB_LOCAL) {
375 old_to_new_syms[i] = q - new_syms;
376 *q++ = *p;
377 }
378 p++;
379 }
380 /* save the number of local symbols in section header */
381 s->sh_info = q - new_syms;
382
383 /* then second pass for non local symbols */
384 p = (ElfW(Sym) *)s->data;
385 for(i = 0; i < nb_syms; i++) {
386 if (ELFW(ST_BIND)(p->st_info) != STB_LOCAL) {
387 old_to_new_syms[i] = q - new_syms;
388 *q++ = *p;
389 }
390 p++;
391 }
392
393 /* we copy the new symbols to the old */
394 memcpy(s->data, new_syms, nb_syms * sizeof(ElfW(Sym)));
395 tcc_free(new_syms);
396
397 /* now we modify all the relocations */
398 for(i = 1; i < s1->nb_sections; i++) {
399 sr = s1->sections[i];
400 if (sr->sh_type == SHT_RELX && sr->link == s) {
401 for_each_elem(sr, 0, rel, ElfW_Rel) {
402 sym_index = ELFW(R_SYM)(rel->r_info);
403 type = ELFW(R_TYPE)(rel->r_info);
404 sym_index = old_to_new_syms[sym_index];
405 rel->r_info = ELFW(R_INFO)(sym_index, type);
406 }
407 }
408 }
409
410 tcc_free(old_to_new_syms);
411 }
412
413 /* relocate common symbols in the .bss section */
414 ST_FUNC void relocate_common_syms(void)
415 {
416 ElfW(Sym) *sym;
417 unsigned long offset, align;
418
419 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
420 if (sym->st_shndx == SHN_COMMON) {
421 /* align symbol */
422 align = sym->st_value;
423 offset = bss_section->data_offset;
424 offset = (offset + align - 1) & -align;
425 sym->st_value = offset;
426 sym->st_shndx = bss_section->sh_num;
427 offset += sym->st_size;
428 bss_section->data_offset = offset;
429 }
430 }
431 }
432
433 /* relocate symbol table, resolve undefined symbols if do_resolve is
434 true and output error if undefined symbol. */
435 ST_FUNC void relocate_syms(TCCState *s1, int do_resolve)
436 {
437 ElfW(Sym) *sym, *esym;
438 int sym_bind, sh_num, sym_index;
439 const char *name;
440
441 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
442 sh_num = sym->st_shndx;
443 if (sh_num == SHN_UNDEF) {
444 name = (char *) strtab_section->data + sym->st_name;
445 /* Use ld.so to resolve symbol for us (for tcc -run) */
446 if (do_resolve) {
447 #if defined TCC_IS_NATIVE && !defined _WIN32
448 void *addr;
449 name = (char *) symtab_section->link->data + sym->st_name;
450 addr = resolve_sym(s1, name);
451 if (addr) {
452 sym->st_value = (addr_t)addr;
453 #ifdef DEBUG_RELOC
454 printf ("relocate_sym: %s -> 0x%lx\n", name, sym->st_value);
455 #endif
456 goto found;
457 }
458 #endif
459 } else if (s1->dynsym) {
460 /* if dynamic symbol exist, then use it */
461 sym_index = find_elf_sym(s1->dynsym, name);
462 if (sym_index) {
463 esym = &((ElfW(Sym) *)s1->dynsym->data)[sym_index];
464 sym->st_value = esym->st_value;
465 goto found;
466 }
467 }
468 /* XXX: _fp_hw seems to be part of the ABI, so we ignore
469 it */
470 if (!strcmp(name, "_fp_hw"))
471 goto found;
472 /* only weak symbols are accepted to be undefined. Their
473 value is zero */
474 sym_bind = ELFW(ST_BIND)(sym->st_info);
475 if (sym_bind == STB_WEAK) {
476 sym->st_value = 0;
477 } else {
478 tcc_error_noabort("undefined symbol '%s'", name);
479 }
480 } else if (sh_num < SHN_LORESERVE) {
481 /* add section base */
482 sym->st_value += s1->sections[sym->st_shndx]->sh_addr;
483 }
484 found: ;
485 }
486 }
487
488 /* relocate a given section (CPU dependent) by applying the relocations
489 in the associated relocation section */
490 ST_FUNC void relocate_section(TCCState *s1, Section *s)
491 {
492 Section *sr = s->reloc;
493 ElfW_Rel *rel;
494 ElfW(Sym) *sym;
495 int type, sym_index;
496 unsigned char *ptr;
497 addr_t val, addr;
498 #if defined TCC_TARGET_I386 || defined TCC_TARGET_X86_64
499 ElfW_Rel *qrel = (ElfW_Rel *) sr->data; /* ptr to next reloc entry reused */
500 int esym_index;
501 #endif
502
503 for_each_elem(sr, 0, rel, ElfW_Rel) {
504 ptr = s->data + rel->r_offset;
505
506 sym_index = ELFW(R_SYM)(rel->r_info);
507 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
508 val = sym->st_value;
509 #if defined(TCC_TARGET_ARM64) || defined(TCC_TARGET_X86_64)
510 val += rel->r_addend;
511 #endif
512 type = ELFW(R_TYPE)(rel->r_info);
513 addr = s->sh_addr + rel->r_offset;
514
515 /* CPU specific */
516 switch(type) {
517 #if defined(TCC_TARGET_I386)
518 case R_386_32:
519 if (s1->output_type == TCC_OUTPUT_DLL) {
520 esym_index = s1->symtab_to_dynsym[sym_index];
521 qrel->r_offset = rel->r_offset;
522 if (esym_index) {
523 qrel->r_info = ELFW(R_INFO)(esym_index, R_386_32);
524 qrel++;
525 break;
526 } else {
527 qrel->r_info = ELFW(R_INFO)(0, R_386_RELATIVE);
528 qrel++;
529 }
530 }
531 write32le(ptr, read32le(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 write32le(ptr, read32le(ptr) + val - addr);
545 break;
546 case R_386_PLT32:
547 write32le(ptr, read32le(ptr) + val - addr);
548 break;
549 case R_386_GLOB_DAT:
550 case R_386_JMP_SLOT:
551 write32le(ptr, val);
552 break;
553 case R_386_GOTPC:
554 write32le(ptr, read32le(ptr) + s1->got->sh_addr - addr);
555 break;
556 case R_386_GOTOFF:
557 write32le(ptr, read32le(ptr) + val - s1->got->sh_addr);
558 break;
559 case R_386_GOT32:
560 /* we load the got offset */
561 write32le(ptr, read32le(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 write16le(ptr, read16le(ptr) + val);
569 break;
570 case R_386_PC16:
571 if (s1->output_format != TCC_OUTPUT_FORMAT_BINARY)
572 goto output_file;
573 write16le(ptr, read16le(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 write64le(ptr, val);
766 break;
767 case R_AARCH64_ABS32:
768 write32le(ptr, val);
769 break;
770 case R_AARCH64_MOVW_UABS_G0_NC:
771 write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
772 (val & 0xffff) << 5));
773 break;
774 case R_AARCH64_MOVW_UABS_G1_NC:
775 write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
776 (val >> 16 & 0xffff) << 5));
777 break;
778 case R_AARCH64_MOVW_UABS_G2_NC:
779 write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
780 (val >> 32 & 0xffff) << 5));
781 break;
782 case R_AARCH64_MOVW_UABS_G3:
783 write32le(ptr, ((read32le(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 write32le(ptr, ((read32le(ptr) & 0x9f00001f) |
791 (off & 0x1ffffc) << 3 | (off & 3) << 29));
792 break;
793 }
794 case R_AARCH64_ADD_ABS_LO12_NC:
795 write32le(ptr, ((read32le(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 write32le(ptr, (0x14000000 |
816 (uint32_t)(type == R_AARCH64_CALL26) << 31 |
817 ((val - addr) >> 2 & 0x3ffffff)));
818 break;
819 case R_AARCH64_ADR_GOT_PAGE: {
820 uint64_t off =
821 (((s1->got->sh_addr +
822 s1->sym_attrs[sym_index].got_offset) >> 12) - (addr >> 12));
823 if ((off + ((uint64_t)1 << 20)) >> 21)
824 tcc_error("R_AARCH64_ADR_GOT_PAGE relocation failed");
825 write32le(ptr, ((read32le(ptr) & 0x9f00001f) |
826 (off & 0x1ffffc) << 3 | (off & 3) << 29));
827 break;
828 }
829 case R_AARCH64_LD64_GOT_LO12_NC:
830 write32le(ptr,
831 ((read32le(ptr) & 0xfff803ff) |
832 ((s1->got->sh_addr +
833 s1->sym_attrs[sym_index].got_offset) & 0xff8) << 7));
834 break;
835 case R_AARCH64_COPY:
836 break;
837 case R_AARCH64_GLOB_DAT:
838 case R_AARCH64_JUMP_SLOT:
839 /* They don't need addend */
840 #ifdef DEBUG_RELOC
841 printf ("reloc %d @ 0x%lx: val=0x%lx name=%s\n", type, addr,
842 val - rel->r_addend,
843 (char *) symtab_section->link->data + sym->st_name);
844 #endif
845 write64le(ptr, val - rel->r_addend);
846 break;
847 default:
848 fprintf(stderr, "FIXME: handle reloc type %x at %x [%p] to %x\n",
849 type, (unsigned)addr, ptr, (unsigned)val);
850 break;
851 #elif defined(TCC_TARGET_C67)
852 case R_C60_32:
853 *(int *)ptr += val;
854 break;
855 case R_C60LO16:
856 {
857 uint32_t orig;
858
859 /* put the low 16 bits of the absolute address
860 add to what is already there */
861
862 orig = ((*(int *)(ptr )) >> 7) & 0xffff;
863 orig |= (((*(int *)(ptr+4)) >> 7) & 0xffff) << 16;
864
865 /* patch both at once - assumes always in pairs Low - High */
866
867 *(int *) ptr = (*(int *) ptr & (~(0xffff << 7)) ) | (((val+orig) & 0xffff) << 7);
868 *(int *)(ptr+4) = (*(int *)(ptr+4) & (~(0xffff << 7)) ) | ((((val+orig)>>16) & 0xffff) << 7);
869 }
870 break;
871 case R_C60HI16:
872 break;
873 default:
874 fprintf(stderr,"FIXME: handle reloc type %x at %x [%p] to %x\n",
875 type, (unsigned)addr, ptr, (unsigned)val);
876 break;
877 #elif defined(TCC_TARGET_X86_64)
878 case R_X86_64_64:
879 if (s1->output_type == TCC_OUTPUT_DLL) {
880 esym_index = s1->symtab_to_dynsym[sym_index];
881 qrel->r_offset = rel->r_offset;
882 if (esym_index) {
883 qrel->r_info = ELFW(R_INFO)(esym_index, R_X86_64_64);
884 qrel->r_addend = rel->r_addend;
885 qrel++;
886 break;
887 } else {
888 qrel->r_info = ELFW(R_INFO)(0, R_X86_64_RELATIVE);
889 qrel->r_addend = read64le(ptr) + val;
890 qrel++;
891 }
892 }
893 write64le(ptr, read64le(ptr) + val);
894 break;
895 case R_X86_64_32:
896 case R_X86_64_32S:
897 if (s1->output_type == TCC_OUTPUT_DLL) {
898 /* XXX: this logic may depend on TCC's codegen
899 now TCC uses R_X86_64_32 even for a 64bit pointer */
900 qrel->r_info = ELFW(R_INFO)(0, R_X86_64_RELATIVE);
901 qrel->r_addend = read32le(ptr) + val;
902 qrel++;
903 }
904 write32le(ptr, read32le(ptr) + val);
905 break;
906
907 case R_X86_64_PC32:
908 if (s1->output_type == TCC_OUTPUT_DLL) {
909 /* DLL relocation */
910 esym_index = s1->symtab_to_dynsym[sym_index];
911 if (esym_index) {
912 qrel->r_offset = rel->r_offset;
913 qrel->r_info = ELFW(R_INFO)(esym_index, R_X86_64_PC32);
914 qrel->r_addend = read32le(ptr);
915 qrel++;
916 break;
917 }
918 }
919 goto plt32pc32;
920
921 case R_X86_64_PLT32:
922 /* We've put the PLT slot offset into r_addend when generating
923 it, and that's what we must use as relocation value (adjusted
924 by section offset of course). */
925 val = s1->plt->sh_addr + rel->r_addend;
926 /* fallthrough. */
927
928 plt32pc32:
929 {
930 long long diff;
931 diff = (long long)val - addr;
932 if (diff < -2147483648LL || diff > 2147483647LL) {
933 tcc_error("internal error: relocation failed");
934 }
935 write32le(ptr, read32le(ptr) + diff);
936 }
937 break;
938 case R_X86_64_GLOB_DAT:
939 case R_X86_64_JUMP_SLOT:
940 /* They don't need addend */
941 write64le(ptr, val - rel->r_addend);
942 break;
943 case R_X86_64_GOTPCREL:
944 write32le(ptr, read32le(ptr) +
945 (s1->got->sh_addr - addr +
946 s1->sym_attrs[sym_index].got_offset - 4));
947 break;
948 case R_X86_64_GOTTPOFF:
949 write32le(ptr, read32le(ptr) + val - s1->got->sh_addr);
950 break;
951 case R_X86_64_GOT32:
952 /* we load the got offset */
953 write32le(ptr, read32le(ptr) + s1->sym_attrs[sym_index].got_offset);
954 break;
955 #else
956 #error unsupported processor
957 #endif
958 }
959 }
960 /* if the relocation is allocated, we change its symbol table */
961 if (sr->sh_flags & SHF_ALLOC)
962 sr->link = s1->dynsym;
963 }
964
965 /* relocate relocation table in 'sr' */
966 static void relocate_rel(TCCState *s1, Section *sr)
967 {
968 Section *s;
969 ElfW_Rel *rel;
970
971 s = s1->sections[sr->sh_info];
972 for_each_elem(sr, 0, rel, ElfW_Rel)
973 rel->r_offset += s->sh_addr;
974 }
975
976 /* count the number of dynamic relocations so that we can reserve
977 their space */
978 static int prepare_dynamic_rel(TCCState *s1, Section *sr)
979 {
980 ElfW_Rel *rel;
981 int sym_index, esym_index, type, count;
982
983 count = 0;
984 for_each_elem(sr, 0, rel, ElfW_Rel) {
985 sym_index = ELFW(R_SYM)(rel->r_info);
986 type = ELFW(R_TYPE)(rel->r_info);
987 switch(type) {
988 #if defined(TCC_TARGET_I386)
989 case R_386_32:
990 #elif defined(TCC_TARGET_X86_64)
991 case R_X86_64_32:
992 case R_X86_64_32S:
993 case R_X86_64_64:
994 #endif
995 count++;
996 break;
997 #if defined(TCC_TARGET_I386)
998 case R_386_PC32:
999 #elif defined(TCC_TARGET_X86_64)
1000 case R_X86_64_PC32:
1001 #endif
1002 esym_index = s1->symtab_to_dynsym[sym_index];
1003 if (esym_index)
1004 count++;
1005 break;
1006 default:
1007 break;
1008 }
1009 }
1010 if (count) {
1011 /* allocate the section */
1012 sr->sh_flags |= SHF_ALLOC;
1013 sr->sh_size = count * sizeof(ElfW_Rel);
1014 }
1015 return count;
1016 }
1017
1018 static struct sym_attr *alloc_sym_attr(TCCState *s1, int index)
1019 {
1020 int n;
1021 struct sym_attr *tab;
1022
1023 if (index >= s1->nb_sym_attrs) {
1024 /* find immediately bigger power of 2 and reallocate array */
1025 n = 1;
1026 while (index >= n)
1027 n *= 2;
1028 tab = tcc_realloc(s1->sym_attrs, n * sizeof(*s1->sym_attrs));
1029 s1->sym_attrs = tab;
1030 memset(s1->sym_attrs + s1->nb_sym_attrs, 0,
1031 (n - s1->nb_sym_attrs) * sizeof(*s1->sym_attrs));
1032 s1->nb_sym_attrs = n;
1033 }
1034 return &s1->sym_attrs[index];
1035 }
1036
1037 static void build_got(TCCState *s1)
1038 {
1039 unsigned char *ptr;
1040
1041 /* if no got, then create it */
1042 s1->got = new_section(s1, ".got", SHT_PROGBITS, SHF_ALLOC | SHF_WRITE);
1043 s1->got->sh_entsize = 4;
1044 add_elf_sym(symtab_section, 0, 4, ELFW(ST_INFO)(STB_GLOBAL, STT_OBJECT),
1045 0, s1->got->sh_num, "_GLOBAL_OFFSET_TABLE_");
1046 ptr = section_ptr_add(s1->got, 3 * PTR_SIZE);
1047 #if PTR_SIZE == 4
1048 /* keep space for _DYNAMIC pointer, if present */
1049 write32le(ptr, 0);
1050 /* two dummy got entries */
1051 write32le(ptr + 4, 0);
1052 write32le(ptr + 8, 0);
1053 #else
1054 /* keep space for _DYNAMIC pointer, if present */
1055 write32le(ptr, 0);
1056 write32le(ptr + 4, 0);
1057 /* two dummy got entries */
1058 write32le(ptr + 8, 0);
1059 write32le(ptr + 12, 0);
1060 write32le(ptr + 16, 0);
1061 write32le(ptr + 20, 0);
1062 #endif
1063 }
1064
1065 /* put a got or plt entry corresponding to a symbol in symtab_section. 'size'
1066 and 'info' can be modifed if more precise info comes from the DLL.
1067 Returns offset of GOT or PLT slot. */
1068 static unsigned long put_got_entry(TCCState *s1,
1069 int reloc_type, unsigned long size, int info,
1070 int sym_index)
1071 {
1072 int index, need_plt_entry;
1073 const char *name;
1074 ElfW(Sym) *sym;
1075 unsigned long offset;
1076 int *ptr;
1077 struct sym_attr *symattr;
1078
1079 if (!s1->got)
1080 build_got(s1);
1081
1082 need_plt_entry =
1083 #ifdef TCC_TARGET_X86_64
1084 (reloc_type == R_X86_64_JUMP_SLOT);
1085 #elif defined(TCC_TARGET_I386)
1086 (reloc_type == R_386_JMP_SLOT);
1087 #elif defined(TCC_TARGET_ARM)
1088 (reloc_type == R_ARM_JUMP_SLOT);
1089 #elif defined(TCC_TARGET_ARM64)
1090 (reloc_type == R_AARCH64_JUMP_SLOT);
1091 #else
1092 0;
1093 #endif
1094
1095 if (need_plt_entry && !s1->plt) {
1096 /* add PLT */
1097 s1->plt = new_section(s1, ".plt", SHT_PROGBITS,
1098 SHF_ALLOC | SHF_EXECINSTR);
1099 s1->plt->sh_entsize = 4;
1100 }
1101
1102 /* If a got/plt entry already exists for that symbol, no need to add one */
1103 if (sym_index < s1->nb_sym_attrs) {
1104 if (need_plt_entry && s1->sym_attrs[sym_index].plt_offset)
1105 return s1->sym_attrs[sym_index].plt_offset;
1106 else if (!need_plt_entry && s1->sym_attrs[sym_index].got_offset)
1107 return s1->sym_attrs[sym_index].got_offset;
1108 }
1109
1110 symattr = alloc_sym_attr(s1, sym_index);
1111
1112 /* Only store the GOT offset if it's not generated for the PLT entry. */
1113 if (!need_plt_entry)
1114 symattr->got_offset = s1->got->data_offset;
1115
1116 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1117 name = (char *) symtab_section->link->data + sym->st_name;
1118 offset = sym->st_value;
1119 #if defined(TCC_TARGET_I386) || defined(TCC_TARGET_X86_64)
1120 if (need_plt_entry) {
1121 Section *plt;
1122 uint8_t *p;
1123 int modrm;
1124 unsigned long relofs;
1125
1126 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
1127 modrm = 0x25;
1128 #else
1129 /* if we build a DLL, we add a %ebx offset */
1130 if (s1->output_type == TCC_OUTPUT_DLL)
1131 modrm = 0xa3;
1132 else
1133 modrm = 0x25;
1134 #endif
1135
1136 /* add a PLT entry */
1137 plt = s1->plt;
1138 if (plt->data_offset == 0) {
1139 /* first plt entry */
1140 p = section_ptr_add(plt, 16);
1141 p[0] = 0xff; /* pushl got + PTR_SIZE */
1142 p[1] = modrm + 0x10;
1143 write32le(p + 2, PTR_SIZE);
1144 p[6] = 0xff; /* jmp *(got + PTR_SIZE * 2) */
1145 p[7] = modrm;
1146 write32le(p + 8, PTR_SIZE * 2);
1147 }
1148
1149 /* The PLT slot refers to the relocation entry it needs
1150 via offset. The reloc entry is created below, so its
1151 offset is the current data_offset. */
1152 relofs = s1->got->reloc ? s1->got->reloc->data_offset : 0;
1153 symattr->plt_offset = plt->data_offset;
1154 p = section_ptr_add(plt, 16);
1155 p[0] = 0xff; /* jmp *(got + x) */
1156 p[1] = modrm;
1157 write32le(p + 2, s1->got->data_offset);
1158 p[6] = 0x68; /* push $xxx */
1159 #ifdef TCC_TARGET_X86_64
1160 /* On x86-64, the relocation is referred to by _index_. */
1161 write32le(p + 7, relofs / sizeof (ElfW_Rel));
1162 #else
1163 write32le(p + 7, relofs);
1164 #endif
1165 p[11] = 0xe9; /* jmp plt_start */
1166 write32le(p + 12, -(plt->data_offset));
1167
1168 /* If this was an UNDEF symbol set the offset in the
1169 dynsymtab to the PLT slot, so that PC32 relocs to it
1170 can be resolved. */
1171 if (sym->st_shndx == SHN_UNDEF)
1172 offset = plt->data_offset - 16;
1173 }
1174 #elif defined(TCC_TARGET_ARM)
1175 if (need_plt_entry) {
1176 Section *plt;
1177 uint8_t *p;
1178
1179 /* if we build a DLL, we add a %ebx offset */
1180 if (s1->output_type == TCC_OUTPUT_DLL)
1181 tcc_error("DLLs unimplemented!");
1182
1183 /* add a PLT entry */
1184 plt = s1->plt;
1185 if (plt->data_offset == 0) {
1186 /* first plt entry */
1187 p = section_ptr_add(plt, 16);
1188 write32le(p, 0xe52de004); /* push {lr} */
1189 write32le(p+4, 0xe59fe010); /* ldr lr, [pc, #16] */
1190 write32le(p+8, 0xe08fe00e); /* add lr, pc, lr */
1191 write32le(p+12, 0xe5bef008); /* ldr pc, [lr, #8]! */
1192 }
1193
1194 symattr->plt_offset = plt->data_offset;
1195 if (symattr->plt_thumb_stub) {
1196 p = section_ptr_add(plt, 20);
1197 write32le(p, 0x4778); /* bx pc */
1198 write32le(p+2, 0x46c0); /* nop */
1199 p += 4;
1200 } else
1201 p = section_ptr_add(plt, 16);
1202 write32le(p, 0xe59fc004); /* ldr ip, [pc, #4] ; GOT entry offset */
1203 write32le(p+4, 0xe08fc00c); /* add ip, pc, ip ; addr of GOT entry */
1204 write32le(p+8, 0xe59cf000); /* ldr pc, [ip] ; jump to GOT entry */
1205 write32le(p+12, s1->got->data_offset); /* GOT entry off once patched */
1206
1207 /* the symbol is modified so that it will be relocated to
1208 the PLT */
1209 if (sym->st_shndx == SHN_UNDEF)
1210 offset = plt->data_offset - 16;
1211 }
1212 #elif defined(TCC_TARGET_ARM64)
1213 if (need_plt_entry) {
1214 Section *plt;
1215 uint8_t *p;
1216
1217 if (s1->output_type == TCC_OUTPUT_DLL)
1218 tcc_error("DLLs unimplemented!");
1219
1220 plt = s1->plt;
1221 if (plt->data_offset == 0)
1222 section_ptr_add(plt, 32);
1223 symattr->plt_offset = plt->data_offset;
1224 p = section_ptr_add(plt, 16);
1225 write32le(p, s1->got->data_offset);
1226 write32le(p + 4, (uint64_t)s1->got->data_offset >> 32);
1227
1228 if (sym->st_shndx == SHN_UNDEF)
1229 offset = plt->data_offset - 16;
1230 }
1231 #elif defined(TCC_TARGET_C67)
1232 if (s1->dynsym) {
1233 tcc_error("C67 got not implemented");
1234 }
1235 #else
1236 #error unsupported CPU
1237 #endif
1238 if (s1->dynsym) {
1239 /* XXX This might generate multiple syms for name. */
1240 index = put_elf_sym(s1->dynsym, offset,
1241 size, info, 0, sym->st_shndx, name);
1242 /* Create the relocation (it's against the GOT for PLT
1243 and GOT relocs). */
1244 put_elf_reloc(s1->dynsym, s1->got,
1245 s1->got->data_offset,
1246 reloc_type, index);
1247 } else {
1248 /* Without .dynsym (i.e. static link or memory output) we
1249 still need relocs against the generated got, so as to fill
1250 the entries with the symbol values (determined later). */
1251 put_elf_reloc(symtab_section, s1->got,
1252 s1->got->data_offset,
1253 reloc_type, sym_index);
1254 }
1255 /* And now create the GOT slot itself. */
1256 ptr = section_ptr_add(s1->got, PTR_SIZE);
1257 *ptr = 0;
1258 if (need_plt_entry)
1259 return symattr->plt_offset;
1260 else
1261 return symattr->got_offset;
1262 }
1263
1264 /* build GOT and PLT entries */
1265 ST_FUNC void build_got_entries(TCCState *s1)
1266 {
1267 Section *s;
1268 ElfW_Rel *rel;
1269 ElfW(Sym) *sym;
1270 int i, type, reloc_type, sym_index;
1271
1272 for(i = 1; i < s1->nb_sections; i++) {
1273 s = s1->sections[i];
1274 if (s->sh_type != SHT_RELX)
1275 continue;
1276 /* no need to handle got relocations */
1277 if (s->link != symtab_section)
1278 continue;
1279 for_each_elem(s, 0, rel, ElfW_Rel) {
1280 type = ELFW(R_TYPE)(rel->r_info);
1281 switch(type) {
1282 #if defined(TCC_TARGET_I386)
1283 case R_386_GOT32:
1284 case R_386_GOTOFF:
1285 case R_386_GOTPC:
1286 case R_386_PLT32:
1287 if (!s1->got)
1288 build_got(s1);
1289 if (type == R_386_GOT32 || type == R_386_PLT32) {
1290 sym_index = ELFW(R_SYM)(rel->r_info);
1291 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1292 /* look at the symbol got offset. If none, then add one */
1293 if (type == R_386_GOT32)
1294 reloc_type = R_386_GLOB_DAT;
1295 else
1296 reloc_type = R_386_JMP_SLOT;
1297 put_got_entry(s1, reloc_type, sym->st_size, sym->st_info,
1298 sym_index);
1299 }
1300 break;
1301 #elif defined(TCC_TARGET_ARM)
1302 case R_ARM_PC24:
1303 case R_ARM_CALL:
1304 case R_ARM_JUMP24:
1305 case R_ARM_GOT32:
1306 case R_ARM_GOTOFF:
1307 case R_ARM_GOTPC:
1308 case R_ARM_PLT32:
1309 if (!s1->got)
1310 build_got(s1);
1311 sym_index = ELFW(R_SYM)(rel->r_info);
1312 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1313 if (type != R_ARM_GOTOFF && type != R_ARM_GOTPC
1314 && sym->st_shndx == SHN_UNDEF) {
1315 unsigned long ofs;
1316 /* look at the symbol got offset. If none, then add one */
1317 if (type == R_ARM_GOT32)
1318 reloc_type = R_ARM_GLOB_DAT;
1319 else
1320 reloc_type = R_ARM_JUMP_SLOT;
1321 ofs = put_got_entry(s1, reloc_type, sym->st_size,
1322 sym->st_info, sym_index);
1323 #ifdef DEBUG_RELOC
1324 printf ("maybegot: %s, %d, %d --> ofs=0x%x\n",
1325 (char *) symtab_section->link->data + sym->st_name,
1326 type, sym->st_shndx, ofs);
1327 #endif
1328 if (type != R_ARM_GOT32) {
1329 addr_t *ptr = (addr_t*)(s1->sections[s->sh_info]->data
1330 + rel->r_offset);
1331 /* x must be signed! */
1332 int x = *ptr & 0xffffff;
1333 x = (x << 8) >> 8;
1334 x <<= 2;
1335 x += ofs;
1336 x >>= 2;
1337 #ifdef DEBUG_RELOC
1338 printf ("insn=0x%x --> 0x%x (x==0x%x)\n", *ptr,
1339 (*ptr & 0xff000000) | x, x);
1340 #endif
1341 *ptr = (*ptr & 0xff000000) | x;
1342 }
1343 }
1344 break;
1345 case R_ARM_THM_JUMP24:
1346 sym_index = ELFW(R_SYM)(rel->r_info);
1347 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1348 /* We are relocating a jump from thumb code to arm code */
1349 if (sym->st_shndx != SHN_UNDEF && !(sym->st_value & 1)) {
1350 int index;
1351 uint8_t *p;
1352 char *name, buf[1024];
1353 Section *text_section;
1354
1355 name = (char *) symtab_section->link->data + sym->st_name;
1356 text_section = s1->sections[sym->st_shndx];
1357 /* Modify reloc to target a thumb stub to switch to ARM */
1358 snprintf(buf, sizeof(buf), "%s_from_thumb", name);
1359 index = put_elf_sym(symtab_section,
1360 text_section->data_offset + 1,
1361 sym->st_size, sym->st_info, 0,
1362 sym->st_shndx, buf);
1363 rel->r_info = ELFW(R_INFO)(index, type);
1364 /* Create a thumb stub fonction to switch to ARM mode */
1365 put_elf_reloc(symtab_section, text_section,
1366 text_section->data_offset + 4, R_ARM_JUMP24,
1367 sym_index);
1368 p = section_ptr_add(text_section, 8);
1369 write32le(p, 0x4778); /* bx pc */
1370 write32le(p+2, 0x46c0); /* nop */
1371 write32le(p+4, 0xeafffffe); /* b $sym */
1372 }
1373 #elif defined(TCC_TARGET_ARM64)
1374 //xx Other cases may be required here:
1375 case R_AARCH64_ADR_GOT_PAGE:
1376 case R_AARCH64_LD64_GOT_LO12_NC:
1377 if (!s1->got)
1378 build_got(s1);
1379 sym_index = ELFW(R_SYM)(rel->r_info);
1380 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1381 reloc_type = R_AARCH64_GLOB_DAT;
1382 put_got_entry(s1, reloc_type, sym->st_size, sym->st_info,
1383 sym_index);
1384 break;
1385
1386 case R_AARCH64_JUMP26:
1387 case R_AARCH64_CALL26:
1388 if (!s1->got)
1389 build_got(s1);
1390 sym_index = ELFW(R_SYM)(rel->r_info);
1391 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1392 if (sym->st_shndx == SHN_UNDEF) {
1393 unsigned long ofs;
1394 reloc_type = R_AARCH64_JUMP_SLOT;
1395 ofs = put_got_entry(s1, reloc_type, sym->st_size,
1396 sym->st_info, sym_index);
1397 /* We store the place of the generated PLT slot
1398 in our addend. */
1399 rel->r_addend += ofs;
1400 }
1401 break;
1402 #elif defined(TCC_TARGET_C67)
1403 case R_C60_GOT32:
1404 case R_C60_GOTOFF:
1405 case R_C60_GOTPC:
1406 case R_C60_PLT32:
1407 if (!s1->got)
1408 build_got(s1);
1409 if (type == R_C60_GOT32 || type == R_C60_PLT32) {
1410 sym_index = ELFW(R_SYM)(rel->r_info);
1411 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1412 /* look at the symbol got offset. If none, then add one */
1413 if (type == R_C60_GOT32)
1414 reloc_type = R_C60_GLOB_DAT;
1415 else
1416 reloc_type = R_C60_JMP_SLOT;
1417 put_got_entry(s1, reloc_type, sym->st_size, sym->st_info,
1418 sym_index);
1419 }
1420 break;
1421 #elif defined(TCC_TARGET_X86_64)
1422 case R_X86_64_GOT32:
1423 case R_X86_64_GOTTPOFF:
1424 case R_X86_64_GOTPCREL:
1425 case R_X86_64_PLT32:
1426 sym_index = ELFW(R_SYM)(rel->r_info);
1427 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1428 if (type == R_X86_64_PLT32 &&
1429 ELFW(ST_VISIBILITY)(sym->st_other) != STV_DEFAULT)
1430 {
1431 rel->r_info = ELFW(R_INFO)(sym_index, R_X86_64_PC32);
1432 break;
1433 }
1434
1435 if (!s1->got) {
1436 build_got(s1);
1437 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1438 }
1439 if (type == R_X86_64_GOT32 || type == R_X86_64_GOTPCREL ||
1440 type == R_X86_64_PLT32) {
1441 unsigned long ofs;
1442 /* look at the symbol got offset. If none, then add one */
1443 if (type == R_X86_64_GOT32 || type == R_X86_64_GOTPCREL)
1444 reloc_type = R_X86_64_GLOB_DAT;
1445 else
1446 reloc_type = R_X86_64_JUMP_SLOT;
1447 ofs = put_got_entry(s1, reloc_type, sym->st_size,
1448 sym->st_info, sym_index);
1449 if (type == R_X86_64_PLT32)
1450 /* We store the place of the generated PLT slot
1451 in our addend. */
1452 rel->r_addend += ofs;
1453 }
1454 break;
1455 #else
1456 #error unsupported CPU
1457 #endif
1458 default:
1459 break;
1460 }
1461 }
1462 }
1463 }
1464
1465 ST_FUNC Section *new_symtab(TCCState *s1,
1466 const char *symtab_name, int sh_type, int sh_flags,
1467 const char *strtab_name,
1468 const char *hash_name, int hash_sh_flags)
1469 {
1470 Section *symtab, *strtab, *hash;
1471 int *ptr, nb_buckets;
1472
1473 symtab = new_section(s1, symtab_name, sh_type, sh_flags);
1474 symtab->sh_entsize = sizeof(ElfW(Sym));
1475 strtab = new_section(s1, strtab_name, SHT_STRTAB, sh_flags);
1476 put_elf_str(strtab, "");
1477 symtab->link = strtab;
1478 put_elf_sym(symtab, 0, 0, 0, 0, 0, NULL);
1479
1480 nb_buckets = 1;
1481
1482 hash = new_section(s1, hash_name, SHT_HASH, hash_sh_flags);
1483 hash->sh_entsize = sizeof(int);
1484 symtab->hash = hash;
1485 hash->link = symtab;
1486
1487 ptr = section_ptr_add(hash, (2 + nb_buckets + 1) * sizeof(int));
1488 ptr[0] = nb_buckets;
1489 ptr[1] = 1;
1490 memset(ptr + 2, 0, (nb_buckets + 1) * sizeof(int));
1491 return symtab;
1492 }
1493
1494 /* put dynamic tag */
1495 static void put_dt(Section *dynamic, int dt, addr_t val)
1496 {
1497 ElfW(Dyn) *dyn;
1498 dyn = section_ptr_add(dynamic, sizeof(ElfW(Dyn)));
1499 dyn->d_tag = dt;
1500 dyn->d_un.d_val = val;
1501 }
1502
1503 static void add_init_array_defines(TCCState *s1, const char *section_name)
1504 {
1505 Section *s;
1506 long end_offset;
1507 char sym_start[1024];
1508 char sym_end[1024];
1509
1510 snprintf(sym_start, sizeof(sym_start), "__%s_start", section_name + 1);
1511 snprintf(sym_end, sizeof(sym_end), "__%s_end", section_name + 1);
1512
1513 s = find_section(s1, section_name);
1514 if (!s) {
1515 end_offset = 0;
1516 s = data_section;
1517 } else {
1518 end_offset = s->data_offset;
1519 }
1520
1521 add_elf_sym(symtab_section,
1522 0, 0,
1523 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1524 s->sh_num, sym_start);
1525 add_elf_sym(symtab_section,
1526 end_offset, 0,
1527 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1528 s->sh_num, sym_end);
1529 }
1530
1531 static int tcc_add_support(TCCState *s1, const char *filename)
1532 {
1533 char buf[1024];
1534 snprintf(buf, sizeof(buf), "%s/%s/%s", s1->tcc_lib_path,
1535 /* an cpu specific path inside tcc_lib_path, mainly for keeping libtcc1.a */
1536 #ifdef TCC_TARGET_I386
1537 "i386"
1538 #endif
1539 #ifdef TCC_TARGET_X86_64
1540 "x86-64"
1541 #endif
1542 #ifdef TCC_TARGET_ARM
1543 "arm"
1544 #endif
1545 #ifdef TCC_TARGET_ARM64
1546 "arm64"
1547 #endif
1548 #ifdef TCC_TARGET_C67
1549 "C67"
1550 #endif
1551 ,filename);
1552
1553 return tcc_add_file(s1, buf, TCC_FILETYPE_BINARY);
1554 }
1555
1556 ST_FUNC void tcc_add_bcheck(TCCState *s1)
1557 {
1558 #ifdef CONFIG_TCC_BCHECK
1559 addr_t *ptr;
1560
1561 if (0 == s1->do_bounds_check)
1562 return;
1563
1564 /* XXX: add an object file to do that */
1565 ptr = section_ptr_add(bounds_section, sizeof(*ptr));
1566 *ptr = 0;
1567 add_elf_sym(symtab_section, 0, 0,
1568 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1569 bounds_section->sh_num, "__bounds_start");
1570 if (s1->output_type != TCC_OUTPUT_MEMORY) {
1571 /* add 'call __bound_init()' in .init section */
1572
1573 /* XXX not called on MSYS, reason is unknown. For this
1574 case a call to __bound_init is performed in bcheck.c
1575 when __bound_ptr_add, __bound_new_region,
1576 __bound_delete_region called */
1577
1578 int sym_index = find_elf_sym(symtab_section, "__bound_init");
1579 if (sym_index) {
1580 Section *init_section = find_section(s1, ".init");
1581 unsigned char *pinit = section_ptr_add(init_section, 5);
1582 pinit[0] = 0xe8;
1583 write32le(pinit + 1, -4);
1584 put_elf_reloc(symtab_section, init_section,
1585 init_section->data_offset - 4, R_386_PC32, sym_index);
1586 }
1587 else
1588 tcc_warning("__bound_init not defined");
1589 }
1590 #endif
1591 }
1592
1593 /* add tcc runtime libraries */
1594 ST_FUNC void tcc_add_runtime(TCCState *s1)
1595 {
1596 tcc_add_pragma_libs(s1);
1597
1598 /* add libc */
1599 if (!s1->nostdlib) {
1600 tcc_add_library(s1, "c");
1601 #ifdef CONFIG_USE_LIBGCC
1602 if (!s1->static_link) {
1603 tcc_add_file(s1, TCC_LIBGCC, TCC_FILETYPE_BINARY);
1604 }
1605 #endif
1606 tcc_add_support(s1, "libtcc1.a");
1607 }
1608
1609 /* tcc_add_bcheck tries to relocate a call to __bound_init in _init so
1610 libtcc1.a must be loaded before for __bound_init to be defined and
1611 crtn.o must be loaded after to not finalize _init too early. */
1612 tcc_add_bcheck(s1);
1613
1614 if (!s1->nostdlib) {
1615 /* add crt end if not memory output */
1616 if (s1->output_type != TCC_OUTPUT_MEMORY)
1617 tcc_add_crt(s1, "crtn.o");
1618 }
1619 }
1620
1621 /* add various standard linker symbols (must be done after the
1622 sections are filled (for example after allocating common
1623 symbols)) */
1624 ST_FUNC void tcc_add_linker_symbols(TCCState *s1)
1625 {
1626 char buf[1024];
1627 int i;
1628 Section *s;
1629
1630 add_elf_sym(symtab_section,
1631 text_section->data_offset, 0,
1632 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1633 text_section->sh_num, "_etext");
1634 add_elf_sym(symtab_section,
1635 data_section->data_offset, 0,
1636 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1637 data_section->sh_num, "_edata");
1638 add_elf_sym(symtab_section,
1639 bss_section->data_offset, 0,
1640 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1641 bss_section->sh_num, "_end");
1642 /* horrible new standard ldscript defines */
1643 add_init_array_defines(s1, ".preinit_array");
1644 add_init_array_defines(s1, ".init_array");
1645 add_init_array_defines(s1, ".fini_array");
1646
1647 /* add start and stop symbols for sections whose name can be
1648 expressed in C */
1649 for(i = 1; i < s1->nb_sections; i++) {
1650 s = s1->sections[i];
1651 if (s->sh_type == SHT_PROGBITS &&
1652 (s->sh_flags & SHF_ALLOC)) {
1653 const char *p;
1654 int ch;
1655
1656 /* check if section name can be expressed in C */
1657 p = s->name;
1658 for(;;) {
1659 ch = *p;
1660 if (!ch)
1661 break;
1662 if (!isid(ch) && !isnum(ch))
1663 goto next_sec;
1664 p++;
1665 }
1666 snprintf(buf, sizeof(buf), "__start_%s", s->name);
1667 add_elf_sym(symtab_section,
1668 0, 0,
1669 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1670 s->sh_num, buf);
1671 snprintf(buf, sizeof(buf), "__stop_%s", s->name);
1672 add_elf_sym(symtab_section,
1673 s->data_offset, 0,
1674 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1675 s->sh_num, buf);
1676 }
1677 next_sec: ;
1678 }
1679 }
1680
1681 static void tcc_output_binary(TCCState *s1, FILE *f,
1682 const int *sec_order)
1683 {
1684 Section *s;
1685 int i, offset, size;
1686
1687 offset = 0;
1688 for(i=1;i<s1->nb_sections;i++) {
1689 s = s1->sections[sec_order[i]];
1690 if (s->sh_type != SHT_NOBITS &&
1691 (s->sh_flags & SHF_ALLOC)) {
1692 while (offset < s->sh_offset) {
1693 fputc(0, f);
1694 offset++;
1695 }
1696 size = s->sh_size;
1697 fwrite(s->data, 1, size, f);
1698 offset += size;
1699 }
1700 }
1701 }
1702
1703 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1704 #define HAVE_PHDR 1
1705 #define EXTRA_RELITEMS 14
1706
1707 /* move the relocation value from .dynsym to .got */
1708 void patch_dynsym_undef(TCCState *s1, Section *s)
1709 {
1710 uint32_t *gotd = (void *)s1->got->data;
1711 ElfW(Sym) *sym;
1712
1713 gotd += 3; /* dummy entries in .got */
1714 /* relocate symbols in .dynsym */
1715 for_each_elem(s, 1, sym, ElfW(Sym)) {
1716 if (sym->st_shndx == SHN_UNDEF) {
1717 *gotd++ = sym->st_value + 6; /* XXX 6 is magic ? */
1718 sym->st_value = 0;
1719 }
1720 }
1721 }
1722 #else
1723 #define HAVE_PHDR 1
1724 #define EXTRA_RELITEMS 9
1725
1726 /* zero plt offsets of weak symbols in .dynsym */
1727 void patch_dynsym_undef(TCCState *s1, Section *s)
1728 {
1729 ElfW(Sym) *sym;
1730
1731 for_each_elem(s, 1, sym, ElfW(Sym))
1732 if (sym->st_shndx == SHN_UNDEF && ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
1733 sym->st_value = 0;
1734 }
1735 #endif
1736
1737 ST_FUNC void fill_got_entry(TCCState *s1, ElfW_Rel *rel)
1738 {
1739 int sym_index = ELFW(R_SYM) (rel->r_info);
1740 ElfW(Sym) *sym = &((ElfW(Sym) *) symtab_section->data)[sym_index];
1741 unsigned long offset;
1742
1743 if (sym_index >= s1->nb_sym_attrs)
1744 return;
1745 offset = s1->sym_attrs[sym_index].got_offset;
1746 section_reserve(s1->got, offset + PTR_SIZE);
1747 #ifdef TCC_TARGET_X86_64
1748 /* only works for x86-64 */
1749 write32le(s1->got->data + offset + 4, sym->st_value >> 32);
1750 #endif
1751 write32le(s1->got->data + offset, sym->st_value & 0xffffffff);
1752 }
1753
1754 /* Perform relocation to GOT or PLT entries */
1755 ST_FUNC void fill_got(TCCState *s1)
1756 {
1757 Section *s;
1758 ElfW_Rel *rel;
1759 int i;
1760
1761 for(i = 1; i < s1->nb_sections; i++) {
1762 s = s1->sections[i];
1763 if (s->sh_type != SHT_RELX)
1764 continue;
1765 /* no need to handle got relocations */
1766 if (s->link != symtab_section)
1767 continue;
1768 for_each_elem(s, 0, rel, ElfW_Rel) {
1769 switch (ELFW(R_TYPE) (rel->r_info)) {
1770 case R_X86_64_GOT32:
1771 case R_X86_64_GOTPCREL:
1772 case R_X86_64_PLT32:
1773 fill_got_entry(s1, rel);
1774 break;
1775 }
1776 }
1777 }
1778 }
1779
1780 /* Bind symbols of executable: resolve undefined symbols from exported symbols
1781 in shared libraries and export non local defined symbols to shared libraries
1782 if -rdynamic switch was given on command line */
1783 static void bind_exe_dynsyms(TCCState *s1)
1784 {
1785 const char *name;
1786 int sym_index, index;
1787 ElfW(Sym) *sym, *esym;
1788 int type;
1789
1790 /* Resolve undefined symbols from dynamic symbols. When there is a match:
1791 - if STT_FUNC or STT_GNU_IFUNC symbol -> add it in PLT
1792 - if STT_OBJECT symbol -> add it in .bss section with suitable reloc */
1793 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
1794 if (sym->st_shndx == SHN_UNDEF) {
1795 name = (char *) symtab_section->link->data + sym->st_name;
1796 sym_index = find_elf_sym(s1->dynsymtab_section, name);
1797 if (sym_index) {
1798 esym = &((ElfW(Sym) *)s1->dynsymtab_section->data)[sym_index];
1799 type = ELFW(ST_TYPE)(esym->st_info);
1800 if ((type == STT_FUNC) || (type == STT_GNU_IFUNC)) {
1801 /* Indirect functions shall have STT_FUNC type in executable
1802 * dynsym section. Indeed, a dlsym call following a lazy
1803 * resolution would pick the symbol value from the
1804 * executable dynsym entry which would contain the address
1805 * of the function wanted by the caller of dlsym instead of
1806 * the address of the function that would return that
1807 * address */
1808 put_got_entry(s1, R_JMP_SLOT, esym->st_size,
1809 ELFW(ST_INFO)(STB_GLOBAL,STT_FUNC),
1810 sym - (ElfW(Sym) *)symtab_section->data);
1811 } else if (type == STT_OBJECT) {
1812 unsigned long offset;
1813 ElfW(Sym) *dynsym;
1814 offset = bss_section->data_offset;
1815 /* XXX: which alignment ? */
1816 offset = (offset + 16 - 1) & -16;
1817 index = put_elf_sym(s1->dynsym, offset, esym->st_size,
1818 esym->st_info, 0, bss_section->sh_num,
1819 name);
1820 /* Ensure R_COPY works for weak symbol aliases */
1821 if (ELFW(ST_BIND)(esym->st_info) == STB_WEAK) {
1822 for_each_elem(s1->dynsymtab_section, 1, dynsym, ElfW(Sym)) {
1823 if ((dynsym->st_value == esym->st_value)
1824 && (ELFW(ST_BIND)(dynsym->st_info) == STB_GLOBAL)) {
1825 char *dynname = (char *) s1->dynsymtab_section->link->data
1826 + dynsym->st_name;
1827 put_elf_sym(s1->dynsym, offset, dynsym->st_size,
1828 dynsym->st_info, 0,
1829 bss_section->sh_num, dynname);
1830 break;
1831 }
1832 }
1833 }
1834 put_elf_reloc(s1->dynsym, bss_section,
1835 offset, R_COPY, index);
1836 offset += esym->st_size;
1837 bss_section->data_offset = offset;
1838 }
1839 } else {
1840 /* STB_WEAK undefined symbols are accepted */
1841 /* XXX: _fp_hw seems to be part of the ABI, so we ignore it */
1842 if (ELFW(ST_BIND)(sym->st_info) == STB_WEAK ||
1843 !strcmp(name, "_fp_hw")) {
1844 } else {
1845 tcc_error_noabort("undefined symbol '%s'", name);
1846 }
1847 }
1848 } else if (s1->rdynamic && ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
1849 /* if -rdynamic option, then export all non local symbols */
1850 name = (char *) symtab_section->link->data + sym->st_name;
1851 put_elf_sym(s1->dynsym, sym->st_value, sym->st_size, sym->st_info,
1852 0, sym->st_shndx, name);
1853 }
1854 }
1855 }
1856
1857 /* Bind symbols of libraries: export non local symbols of executable that
1858 resolve undefined symbols of shared libraries */
1859 static void bind_libs_dynsyms(TCCState *s1)
1860 {
1861 const char *name;
1862 int sym_index;
1863 ElfW(Sym) *sym, *esym;
1864
1865 /* now look at unresolved dynamic symbols and export
1866 corresponding symbol */
1867 for_each_elem(s1->dynsymtab_section, 1, esym, ElfW(Sym)) {
1868 name = (char *) s1->dynsymtab_section->link->data + esym->st_name;
1869 sym_index = find_elf_sym(symtab_section, name);
1870 if (sym_index) {
1871 /* XXX: avoid adding a symbol if already present because of
1872 -rdynamic ? */
1873 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1874 if (sym->st_shndx != SHN_UNDEF)
1875 put_elf_sym(s1->dynsym, sym->st_value, sym->st_size,
1876 sym->st_info, 0, sym->st_shndx, name);
1877 } else if (esym->st_shndx == SHN_UNDEF) {
1878 /* weak symbols can stay undefined */
1879 if (ELFW(ST_BIND)(esym->st_info) != STB_WEAK)
1880 tcc_warning("undefined dynamic symbol '%s'", name);
1881 }
1882 }
1883 }
1884
1885 /* Export all non local symbols (for shared libraries) */
1886 static void export_global_syms(TCCState *s1)
1887 {
1888 int nb_syms, dynindex, index;
1889 const char *name;
1890 ElfW(Sym) *sym;
1891
1892 nb_syms = symtab_section->data_offset / sizeof(ElfW(Sym));
1893 s1->symtab_to_dynsym = tcc_mallocz(sizeof(int) * nb_syms);
1894 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
1895 if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
1896 name = (char *) symtab_section->link->data + sym->st_name;
1897 dynindex = put_elf_sym(s1->dynsym, sym->st_value, sym->st_size,
1898 sym->st_info, 0, sym->st_shndx, name);
1899 index = sym - (ElfW(Sym) *) symtab_section->data;
1900 s1->symtab_to_dynsym[index] = dynindex;
1901 }
1902 }
1903 }
1904
1905 /* relocate the PLT: compute addresses and offsets in the PLT now that final
1906 address for PLT and GOT are known (see fill_program_header) */
1907 ST_FUNC void relocate_plt(TCCState *s1)
1908 {
1909 uint8_t *p, *p_end;
1910
1911 if (!s1->plt)
1912 return;
1913
1914 p = s1->plt->data;
1915 p_end = p + s1->plt->data_offset;
1916 if (p < p_end) {
1917 #if defined(TCC_TARGET_I386)
1918 write32le(p + 2, read32le(p + 2) + s1->got->sh_addr);
1919 write32le(p + 8, read32le(p + 8) + s1->got->sh_addr);
1920 p += 16;
1921 while (p < p_end) {
1922 write32le(p + 2, read32le(p + 2) + s1->got->sh_addr);
1923 p += 16;
1924 }
1925 #elif defined(TCC_TARGET_X86_64)
1926 int x = s1->got->sh_addr - s1->plt->sh_addr - 6;
1927 write32le(p + 2, read32le(p + 2) + x);
1928 write32le(p + 8, read32le(p + 8) + x - 6);
1929 p += 16;
1930 while (p < p_end) {
1931 write32le(p + 2, read32le(p + 2) + x + s1->plt->data - p);
1932 p += 16;
1933 }
1934 #elif defined(TCC_TARGET_ARM)
1935 int x;
1936 x=s1->got->sh_addr - s1->plt->sh_addr - 12;
1937 p += 16;
1938 while (p < p_end) {
1939 if (read32le(p) == 0x46c04778) /* PLT Thumb stub present */
1940 p += 4;
1941 write32le(p + 12, x + read32le(p + 12) + s1->plt->data - p);
1942 p += 16;
1943 }
1944 #elif defined(TCC_TARGET_ARM64)
1945 uint64_t plt = s1->plt->sh_addr;
1946 uint64_t got = s1->got->sh_addr;
1947 uint64_t off = (got >> 12) - (plt >> 12);
1948 if ((off + ((uint32_t)1 << 20)) >> 21)
1949 tcc_error("Failed relocating PLT (off=0x%lx, got=0x%lx, plt=0x%lx)", off, got, plt);
1950 write32le(p, 0xa9bf7bf0); // stp x16,x30,[sp,#-16]!
1951 write32le(p + 4, (0x90000010 | // adrp x16,...
1952 (off & 0x1ffffc) << 3 | (off & 3) << 29));
1953 write32le(p + 8, (0xf9400211 | // ldr x17,[x16,#...]
1954 (got & 0xff8) << 7));
1955 write32le(p + 12, (0x91000210 | // add x16,x16,#...
1956 (got & 0xfff) << 10));
1957 write32le(p + 16, 0xd61f0220); // br x17
1958 write32le(p + 20, 0xd503201f); // nop
1959 write32le(p + 24, 0xd503201f); // nop
1960 write32le(p + 28, 0xd503201f); // nop
1961 p += 32;
1962 while (p < p_end) {
1963 uint64_t pc = plt + (p - s1->plt->data);
1964 uint64_t addr = got + read64le(p);
1965 uint64_t off = (addr >> 12) - (pc >> 12);
1966 if ((off + ((uint32_t)1 << 20)) >> 21)
1967 tcc_error("Failed relocating PLT (off=0x%lx, addr=0x%lx, pc=0x%lx)", off, addr, pc);
1968 write32le(p, (0x90000010 | // adrp x16,...
1969 (off & 0x1ffffc) << 3 | (off & 3) << 29));
1970 write32le(p + 4, (0xf9400211 | // ldr x17,[x16,#...]
1971 (addr & 0xff8) << 7));
1972 write32le(p + 8, (0x91000210 | // add x16,x16,#...
1973 (addr & 0xfff) << 10));
1974 write32le(p + 12, 0xd61f0220); // br x17
1975 p += 16;
1976 }
1977 #elif defined(TCC_TARGET_C67)
1978 /* XXX: TODO */
1979 #else
1980 #error unsupported CPU
1981 #endif
1982 }
1983 }
1984
1985 /* Allocate strings for section names and decide if an unallocated section
1986 should be output.
1987
1988 NOTE: the strsec section comes last, so its size is also correct ! */
1989 static void alloc_sec_names(TCCState *s1, int file_type, Section *strsec)
1990 {
1991 int i;
1992 Section *s;
1993
1994 /* Allocate strings for section names */
1995 for(i = 1; i < s1->nb_sections; i++) {
1996 s = s1->sections[i];
1997 s->sh_name = put_elf_str(strsec, s->name);
1998 /* when generating a DLL, we include relocations but we may
1999 patch them */
2000 if (file_type == TCC_OUTPUT_DLL &&
2001 s->sh_type == SHT_RELX &&
2002 !(s->sh_flags & SHF_ALLOC)) {
2003 /* gr: avoid bogus relocs for empty (debug) sections */
2004 if (s1->sections[s->sh_info]->sh_flags & SHF_ALLOC)
2005 prepare_dynamic_rel(s1, s);
2006 else if (s1->do_debug)
2007 s->sh_size = s->data_offset;
2008 } else if (s1->do_debug ||
2009 file_type == TCC_OUTPUT_OBJ ||
2010 file_type == TCC_OUTPUT_EXE ||
2011 (s->sh_flags & SHF_ALLOC) ||
2012 i == (s1->nb_sections - 1)) {
2013 /* we output all sections if debug or object file */
2014 s->sh_size = s->data_offset;
2015 }
2016 }
2017 }
2018
2019 /* Info to be copied in dynamic section */
2020 struct dyn_inf {
2021 Section *dynamic;
2022 Section *dynstr;
2023 unsigned long dyn_rel_off;
2024 addr_t rel_addr;
2025 addr_t rel_size;
2026 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2027 addr_t bss_addr;
2028 addr_t bss_size;
2029 #endif
2030 };
2031
2032 /* Assign sections to segments and decide how are sections laid out when loaded
2033 in memory. This function also fills corresponding program headers. */
2034 static int layout_sections(TCCState *s1, ElfW(Phdr) *phdr, int phnum,
2035 Section *interp, Section* strsec,
2036 struct dyn_inf *dyninf, int *sec_order)
2037 {
2038 int i, j, k, file_type, sh_order_index, file_offset;
2039 unsigned long s_align;
2040 long long tmp;
2041 addr_t addr;
2042 ElfW(Phdr) *ph;
2043 Section *s;
2044
2045 file_type = s1->output_type;
2046 sh_order_index = 1;
2047 file_offset = 0;
2048 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF)
2049 file_offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr));
2050 s_align = ELF_PAGE_SIZE;
2051 if (s1->section_align)
2052 s_align = s1->section_align;
2053
2054 if (phnum > 0) {
2055 if (s1->has_text_addr) {
2056 int a_offset, p_offset;
2057 addr = s1->text_addr;
2058 /* we ensure that (addr % ELF_PAGE_SIZE) == file_offset %
2059 ELF_PAGE_SIZE */
2060 a_offset = (int) (addr & (s_align - 1));
2061 p_offset = file_offset & (s_align - 1);
2062 if (a_offset < p_offset)
2063 a_offset += s_align;
2064 file_offset += (a_offset - p_offset);
2065 } else {
2066 if (file_type == TCC_OUTPUT_DLL)
2067 addr = 0;
2068 else
2069 addr = ELF_START_ADDR;
2070 /* compute address after headers */
2071 addr += (file_offset & (s_align - 1));
2072 }
2073
2074 ph = &phdr[0];
2075 /* Leave one program headers for the program interpreter and one for
2076 the program header table itself if needed. These are done later as
2077 they require section layout to be done first. */
2078 if (interp)
2079 ph += 1 + HAVE_PHDR;
2080
2081 /* dynamic relocation table information, for .dynamic section */
2082 dyninf->rel_addr = dyninf->rel_size = 0;
2083 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2084 dyninf->bss_addr = dyninf->bss_size = 0;
2085 #endif
2086
2087 for(j = 0; j < 2; j++) {
2088 ph->p_type = PT_LOAD;
2089 if (j == 0)
2090 ph->p_flags = PF_R | PF_X;
2091 else
2092 ph->p_flags = PF_R | PF_W;
2093 ph->p_align = s_align;
2094
2095 /* Decide the layout of sections loaded in memory. This must
2096 be done before program headers are filled since they contain
2097 info about the layout. We do the following ordering: interp,
2098 symbol tables, relocations, progbits, nobits */
2099 /* XXX: do faster and simpler sorting */
2100 for(k = 0; k < 5; k++) {
2101 for(i = 1; i < s1->nb_sections; i++) {
2102 s = s1->sections[i];
2103 /* compute if section should be included */
2104 if (j == 0) {
2105 if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) !=
2106 SHF_ALLOC)
2107 continue;
2108 } else {
2109 if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) !=
2110 (SHF_ALLOC | SHF_WRITE))
2111 continue;
2112 }
2113 if (s == interp) {
2114 if (k != 0)
2115 continue;
2116 } else if (s->sh_type == SHT_DYNSYM ||
2117 s->sh_type == SHT_STRTAB ||
2118 s->sh_type == SHT_HASH) {
2119 if (k != 1)
2120 continue;
2121 } else if (s->sh_type == SHT_RELX) {
2122 if (k != 2)
2123 continue;
2124 } else if (s->sh_type == SHT_NOBITS) {
2125 if (k != 4)
2126 continue;
2127 } else {
2128 if (k != 3)
2129 continue;
2130 }
2131 sec_order[sh_order_index++] = i;
2132
2133 /* section matches: we align it and add its size */
2134 tmp = addr;
2135 addr = (addr + s->sh_addralign - 1) &
2136 ~(s->sh_addralign - 1);
2137 file_offset += (int) ( addr - tmp );
2138 s->sh_offset = file_offset;
2139 s->sh_addr = addr;
2140
2141 /* update program header infos */
2142 if (ph->p_offset == 0) {
2143 ph->p_offset = file_offset;
2144 ph->p_vaddr = addr;
2145 ph->p_paddr = ph->p_vaddr;
2146 }
2147 /* update dynamic relocation infos */
2148 if (s->sh_type == SHT_RELX) {
2149 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2150 if (!strcmp(strsec->data + s->sh_name, ".rel.got")) {
2151 dyninf->rel_addr = addr;
2152 dyninf->rel_size += s->sh_size; /* XXX only first rel. */
2153 }
2154 if (!strcmp(strsec->data + s->sh_name, ".rel.bss")) {
2155 dyninf->bss_addr = addr;
2156 dyninf->bss_size = s->sh_size; /* XXX only first rel. */
2157 }
2158 #else
2159 if (dyninf->rel_size == 0)
2160 dyninf->rel_addr = addr;
2161 dyninf->rel_size += s->sh_size;
2162 #endif
2163 }
2164 addr += s->sh_size;
2165 if (s->sh_type != SHT_NOBITS)
2166 file_offset += s->sh_size;
2167 }
2168 }
2169 if (j == 0) {
2170 /* Make the first PT_LOAD segment include the program
2171 headers itself (and the ELF header as well), it'll
2172 come out with same memory use but will make various
2173 tools like binutils strip work better. */
2174 ph->p_offset &= ~(ph->p_align - 1);
2175 ph->p_vaddr &= ~(ph->p_align - 1);
2176 ph->p_paddr &= ~(ph->p_align - 1);
2177 }
2178 ph->p_filesz = file_offset - ph->p_offset;
2179 ph->p_memsz = addr - ph->p_vaddr;
2180 ph++;
2181 if (j == 0) {
2182 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF) {
2183 /* if in the middle of a page, we duplicate the page in
2184 memory so that one copy is RX and the other is RW */
2185 if ((addr & (s_align - 1)) != 0)
2186 addr += s_align;
2187 } else {
2188 addr = (addr + s_align - 1) & ~(s_align - 1);
2189 file_offset = (file_offset + s_align - 1) & ~(s_align - 1);
2190 }
2191 }
2192 }
2193 }
2194
2195 /* all other sections come after */
2196 for(i = 1; i < s1->nb_sections; i++) {
2197 s = s1->sections[i];
2198 if (phnum > 0 && (s->sh_flags & SHF_ALLOC))
2199 continue;
2200 sec_order[sh_order_index++] = i;
2201
2202 file_offset = (file_offset + s->sh_addralign - 1) &
2203 ~(s->sh_addralign - 1);
2204 s->sh_offset = file_offset;
2205 if (s->sh_type != SHT_NOBITS)
2206 file_offset += s->sh_size;
2207 }
2208
2209 return file_offset;
2210 }
2211
2212 static void fill_unloadable_phdr(ElfW(Phdr) *phdr, int phnum, Section *interp,
2213 Section *dynamic)
2214 {
2215 ElfW(Phdr) *ph;
2216
2217 /* if interpreter, then add corresponding program header */
2218 if (interp) {
2219 ph = &phdr[0];
2220
2221 if (HAVE_PHDR)
2222 {
2223 int len = phnum * sizeof(ElfW(Phdr));
2224
2225 ph->p_type = PT_PHDR;
2226 ph->p_offset = sizeof(ElfW(Ehdr));
2227 ph->p_vaddr = interp->sh_addr - len;
2228 ph->p_paddr = ph->p_vaddr;
2229 ph->p_filesz = ph->p_memsz = len;
2230 ph->p_flags = PF_R | PF_X;
2231 ph->p_align = 4; /* interp->sh_addralign; */
2232 ph++;
2233 }
2234
2235 ph->p_type = PT_INTERP;
2236 ph->p_offset = interp->sh_offset;
2237 ph->p_vaddr = interp->sh_addr;
2238 ph->p_paddr = ph->p_vaddr;
2239 ph->p_filesz = interp->sh_size;
2240 ph->p_memsz = interp->sh_size;
2241 ph->p_flags = PF_R;
2242 ph->p_align = interp->sh_addralign;
2243 }
2244
2245 /* if dynamic section, then add corresponding program header */
2246 if (dynamic) {
2247 ph = &phdr[phnum - 1];
2248
2249 ph->p_type = PT_DYNAMIC;
2250 ph->p_offset = dynamic->sh_offset;
2251 ph->p_vaddr = dynamic->sh_addr;
2252 ph->p_paddr = ph->p_vaddr;
2253 ph->p_filesz = dynamic->sh_size;
2254 ph->p_memsz = dynamic->sh_size;
2255 ph->p_flags = PF_R | PF_W;
2256 ph->p_align = dynamic->sh_addralign;
2257 }
2258 }
2259
2260 /* Fill the dynamic section with tags describing the address and size of
2261 sections */
2262 static void fill_dynamic(TCCState *s1, struct dyn_inf *dyninf)
2263 {
2264 Section *dynamic;
2265
2266 dynamic = dyninf->dynamic;
2267
2268 /* put dynamic section entries */
2269 dynamic->data_offset = dyninf->dyn_rel_off;
2270 put_dt(dynamic, DT_HASH, s1->dynsym->hash->sh_addr);
2271 put_dt(dynamic, DT_STRTAB, dyninf->dynstr->sh_addr);
2272 put_dt(dynamic, DT_SYMTAB, s1->dynsym->sh_addr);
2273 put_dt(dynamic, DT_STRSZ, dyninf->dynstr->data_offset);
2274 put_dt(dynamic, DT_SYMENT, sizeof(ElfW(Sym)));
2275 #if defined(TCC_TARGET_ARM64) || defined(TCC_TARGET_X86_64)
2276 put_dt(dynamic, DT_RELA, dyninf->rel_addr);
2277 put_dt(dynamic, DT_RELASZ, dyninf->rel_size);
2278 put_dt(dynamic, DT_RELAENT, sizeof(ElfW_Rel));
2279 #else
2280 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2281 put_dt(dynamic, DT_PLTGOT, s1->got->sh_addr);
2282 put_dt(dynamic, DT_PLTRELSZ, dyninf->rel_size);
2283 put_dt(dynamic, DT_JMPREL, dyninf->rel_addr);
2284 put_dt(dynamic, DT_PLTREL, DT_REL);
2285 put_dt(dynamic, DT_REL, dyninf->bss_addr);
2286 put_dt(dynamic, DT_RELSZ, dyninf->bss_size);
2287 #else
2288 put_dt(dynamic, DT_REL, dyninf->rel_addr);
2289 put_dt(dynamic, DT_RELSZ, dyninf->rel_size);
2290 put_dt(dynamic, DT_RELENT, sizeof(ElfW_Rel));
2291 #endif
2292 #endif
2293 if (s1->do_debug)
2294 put_dt(dynamic, DT_DEBUG, 0);
2295 put_dt(dynamic, DT_NULL, 0);
2296 }
2297
2298 /* Relocate remaining sections and symbols (that is those not related to
2299 dynamic linking) */
2300 static int final_sections_reloc(TCCState *s1)
2301 {
2302 int i;
2303 Section *s;
2304
2305 relocate_syms(s1, 0);
2306
2307 if (s1->nb_errors != 0)
2308 return -1;
2309
2310 /* relocate sections */
2311 /* XXX: ignore sections with allocated relocations ? */
2312 for(i = 1; i < s1->nb_sections; i++) {
2313 s = s1->sections[i];
2314 #ifdef TCC_TARGET_I386
2315 if (s->reloc && s != s1->got && (s->sh_flags & SHF_ALLOC)) //gr
2316 /* On X86 gdb 7.3 works in any case but gdb 6.6 will crash if SHF_ALLOC
2317 checking is removed */
2318 #else
2319 if (s->reloc && s != s1->got)
2320 /* On X86_64 gdb 7.3 will crash if SHF_ALLOC checking is present */
2321 #endif
2322 relocate_section(s1, s);
2323 }
2324
2325 /* relocate relocation entries if the relocation tables are
2326 allocated in the executable */
2327 for(i = 1; i < s1->nb_sections; i++) {
2328 s = s1->sections[i];
2329 if ((s->sh_flags & SHF_ALLOC) &&
2330 s->sh_type == SHT_RELX) {
2331 relocate_rel(s1, s);
2332 }
2333 }
2334 return 0;
2335 }
2336
2337 /* Create an ELF file on disk.
2338 This function handle ELF specific layout requirements */
2339 static void tcc_output_elf(TCCState *s1, FILE *f, int phnum, ElfW(Phdr) *phdr,
2340 int file_offset, int *sec_order)
2341 {
2342 int i, shnum, offset, size, file_type;
2343 Section *s;
2344 ElfW(Ehdr) ehdr;
2345 ElfW(Shdr) shdr, *sh;
2346
2347 file_type = s1->output_type;
2348 shnum = s1->nb_sections;
2349
2350 memset(&ehdr, 0, sizeof(ehdr));
2351
2352 if (phnum > 0) {
2353 ehdr.e_phentsize = sizeof(ElfW(Phdr));
2354 ehdr.e_phnum = phnum;
2355 ehdr.e_phoff = sizeof(ElfW(Ehdr));
2356 }
2357
2358 /* align to 4 */
2359 file_offset = (file_offset + 3) & -4;
2360
2361 /* fill header */
2362 ehdr.e_ident[0] = ELFMAG0;
2363 ehdr.e_ident[1] = ELFMAG1;
2364 ehdr.e_ident[2] = ELFMAG2;
2365 ehdr.e_ident[3] = ELFMAG3;
2366 ehdr.e_ident[4] = ELFCLASSW;
2367 ehdr.e_ident[5] = ELFDATA2LSB;
2368 ehdr.e_ident[6] = EV_CURRENT;
2369 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2370 ehdr.e_ident[EI_OSABI] = ELFOSABI_FREEBSD;
2371 #endif
2372 #ifdef TCC_TARGET_ARM
2373 #ifdef TCC_ARM_EABI
2374 ehdr.e_ident[EI_OSABI] = 0;
2375 ehdr.e_flags = EF_ARM_EABI_VER4;
2376 if (file_type == TCC_OUTPUT_EXE || file_type == TCC_OUTPUT_DLL)
2377 ehdr.e_flags |= EF_ARM_HASENTRY;
2378 if (s1->float_abi == ARM_HARD_FLOAT)
2379 ehdr.e_flags |= EF_ARM_VFP_FLOAT;
2380 else
2381 ehdr.e_flags |= EF_ARM_SOFT_FLOAT;
2382 #else
2383 ehdr.e_ident[EI_OSABI] = ELFOSABI_ARM;
2384 #endif
2385 #endif
2386 switch(file_type) {
2387 default:
2388 case TCC_OUTPUT_EXE:
2389 ehdr.e_type = ET_EXEC;
2390 ehdr.e_entry = get_elf_sym_addr(s1, "_start", 1);
2391 break;
2392 case TCC_OUTPUT_DLL:
2393 ehdr.e_type = ET_DYN;
2394 ehdr.e_entry = text_section->sh_addr; /* XXX: is it correct ? */
2395 break;
2396 case TCC_OUTPUT_OBJ:
2397 ehdr.e_type = ET_REL;
2398 break;
2399 }
2400 ehdr.e_machine = EM_TCC_TARGET;
2401 ehdr.e_version = EV_CURRENT;
2402 ehdr.e_shoff = file_offset;
2403 ehdr.e_ehsize = sizeof(ElfW(Ehdr));
2404 ehdr.e_shentsize = sizeof(ElfW(Shdr));
2405 ehdr.e_shnum = shnum;
2406 ehdr.e_shstrndx = shnum - 1;
2407
2408 fwrite(&ehdr, 1, sizeof(ElfW(Ehdr)), f);
2409 fwrite(phdr, 1, phnum * sizeof(ElfW(Phdr)), f);
2410 offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr));
2411
2412 sort_syms(s1, symtab_section);
2413 for(i = 1; i < s1->nb_sections; i++) {
2414 s = s1->sections[sec_order[i]];
2415 if (s->sh_type != SHT_NOBITS) {
2416 if (s->sh_type == SHT_DYNSYM)
2417 patch_dynsym_undef(s1, s);
2418 while (offset < s->sh_offset) {
2419 fputc(0, f);
2420 offset++;
2421 }
2422 size = s->sh_size;
2423 if (size)
2424 fwrite(s->data, 1, size, f);
2425 offset += size;
2426 }
2427 }
2428
2429 /* output section headers */
2430 while (offset < ehdr.e_shoff) {
2431 fputc(0, f);
2432 offset++;
2433 }
2434
2435 for(i = 0; i < s1->nb_sections; i++) {
2436 sh = &shdr;
2437 memset(sh, 0, sizeof(ElfW(Shdr)));
2438 s = s1->sections[i];
2439 if (s) {
2440 sh->sh_name = s->sh_name;
2441 sh->sh_type = s->sh_type;
2442 sh->sh_flags = s->sh_flags;
2443 sh->sh_entsize = s->sh_entsize;
2444 sh->sh_info = s->sh_info;
2445 if (s->link)
2446 sh->sh_link = s->link->sh_num;
2447 sh->sh_addralign = s->sh_addralign;
2448 sh->sh_addr = s->sh_addr;
2449 sh->sh_offset = s->sh_offset;
2450 sh->sh_size = s->sh_size;
2451 }
2452 fwrite(sh, 1, sizeof(ElfW(Shdr)), f);
2453 }
2454 }
2455
2456 /* Write an elf, coff or "binary" file */
2457 static int tcc_write_elf_file(TCCState *s1, const char *filename, int phnum,
2458 ElfW(Phdr) *phdr, int file_offset, int *sec_order)
2459 {
2460 int fd, mode, file_type;
2461 FILE *f;
2462
2463 file_type = s1->output_type;
2464 if (file_type == TCC_OUTPUT_OBJ)
2465 mode = 0666;
2466 else
2467 mode = 0777;
2468 unlink(filename);
2469 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, mode);
2470 if (fd < 0) {
2471 tcc_error_noabort("could not write '%s'", filename);
2472 return -1;
2473 }
2474 f = fdopen(fd, "wb");
2475 if (s1->verbose)
2476 printf("<- %s\n", filename);
2477
2478 #ifdef TCC_TARGET_COFF
2479 if (s1->output_format == TCC_OUTPUT_FORMAT_COFF)
2480 tcc_output_coff(s1, f);
2481 else
2482 #endif
2483 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF)
2484 tcc_output_elf(s1, f, phnum, phdr, file_offset, sec_order);
2485 else
2486 tcc_output_binary(s1, f, sec_order);
2487 fclose(f);
2488
2489 return 0;
2490 }
2491
2492 /* Output an elf, coff or binary file */
2493 /* XXX: suppress unneeded sections */
2494 static int elf_output_file(TCCState *s1, const char *filename)
2495 {
2496 int i, ret, phnum, shnum, file_type, file_offset, *sec_order;
2497 struct dyn_inf dyninf;
2498 ElfW(Phdr) *phdr;
2499 ElfW(Sym) *sym;
2500 Section *strsec, *interp, *dynamic, *dynstr;
2501
2502 file_type = s1->output_type;
2503 s1->nb_errors = 0;
2504
2505 /* if linking, also link in runtime libraries (libc, libgcc, etc.) */
2506 if (file_type != TCC_OUTPUT_OBJ) {
2507 tcc_add_runtime(s1);
2508 }
2509
2510 phdr = NULL;
2511 sec_order = NULL;
2512 interp = dynamic = dynstr = NULL; /* avoid warning */
2513 dyninf.dyn_rel_off = 0; /* avoid warning */
2514
2515 if (file_type != TCC_OUTPUT_OBJ) {
2516 relocate_common_syms();
2517
2518 tcc_add_linker_symbols(s1);
2519
2520 if (!s1->static_link) {
2521 if (file_type == TCC_OUTPUT_EXE) {
2522 char *ptr;
2523 /* allow override the dynamic loader */
2524 const char *elfint = getenv("LD_SO");
2525 if (elfint == NULL)
2526 elfint = DEFAULT_ELFINTERP(s1);
2527 /* add interpreter section only if executable */
2528 interp = new_section(s1, ".interp", SHT_PROGBITS, SHF_ALLOC);
2529 interp->sh_addralign = 1;
2530 ptr = section_ptr_add(interp, 1 + strlen(elfint));
2531 strcpy(ptr, elfint);
2532 }
2533
2534 /* add dynamic symbol table */
2535 s1->dynsym = new_symtab(s1, ".dynsym", SHT_DYNSYM, SHF_ALLOC,
2536 ".dynstr",
2537 ".hash", SHF_ALLOC);
2538 dynstr = s1->dynsym->link;
2539
2540 /* add dynamic section */
2541 dynamic = new_section(s1, ".dynamic", SHT_DYNAMIC,
2542 SHF_ALLOC | SHF_WRITE);
2543 dynamic->link = dynstr;
2544 dynamic->sh_entsize = sizeof(ElfW(Dyn));
2545
2546 build_got(s1);
2547
2548 if (file_type == TCC_OUTPUT_EXE) {
2549 bind_exe_dynsyms(s1);
2550
2551 if (s1->nb_errors) {
2552 ret = -1;
2553 goto the_end;
2554 }
2555
2556 bind_libs_dynsyms(s1);
2557 } else /* shared library case: simply export all global symbols */
2558 export_global_syms(s1);
2559
2560 build_got_entries(s1);
2561
2562 /* add a list of needed dlls */
2563 for(i = 0; i < s1->nb_loaded_dlls; i++) {
2564 DLLReference *dllref = s1->loaded_dlls[i];
2565 if (dllref->level == 0)
2566 put_dt(dynamic, DT_NEEDED, put_elf_str(dynstr, dllref->name));
2567 }
2568
2569 if (s1->rpath)
2570 put_dt(dynamic, DT_RPATH, put_elf_str(dynstr, s1->rpath));
2571
2572 /* XXX: currently, since we do not handle PIC code, we
2573 must relocate the readonly segments */
2574 if (file_type == TCC_OUTPUT_DLL) {
2575 if (s1->soname)
2576 put_dt(dynamic, DT_SONAME, put_elf_str(dynstr, s1->soname));
2577 put_dt(dynamic, DT_TEXTREL, 0);
2578 }
2579
2580 if (s1->symbolic)
2581 put_dt(dynamic, DT_SYMBOLIC, 0);
2582
2583 /* add necessary space for other entries */
2584 dyninf.dyn_rel_off = dynamic->data_offset;
2585 dynamic->data_offset += sizeof(ElfW(Dyn)) * EXTRA_RELITEMS;
2586 } else {
2587 /* still need to build got entries in case of static link */
2588 build_got_entries(s1);
2589 }
2590 }
2591
2592 /* we add a section for symbols */
2593 strsec = new_section(s1, ".shstrtab", SHT_STRTAB, 0);
2594 put_elf_str(strsec, "");
2595
2596 /* compute number of sections */
2597 shnum = s1->nb_sections;
2598
2599 /* this array is used to reorder sections in the output file */
2600 sec_order = tcc_malloc(sizeof(int) * shnum);
2601 sec_order[0] = 0;
2602
2603 /* compute number of program headers */
2604 switch(file_type) {
2605 default:
2606 case TCC_OUTPUT_OBJ:
2607 phnum = 0;
2608 break;
2609 case TCC_OUTPUT_EXE:
2610 if (!s1->static_link)
2611 phnum = 4 + HAVE_PHDR;
2612 else
2613 phnum = 2;
2614 break;
2615 case TCC_OUTPUT_DLL:
2616 phnum = 3;
2617 break;
2618 }
2619
2620 /* Allocate strings for section names */
2621 alloc_sec_names(s1, file_type, strsec);
2622
2623 /* allocate program segment headers */
2624 phdr = tcc_mallocz(phnum * sizeof(ElfW(Phdr)));
2625
2626 /* compute section to program header mapping */
2627 file_offset = layout_sections(s1, phdr, phnum, interp, strsec, &dyninf,
2628 sec_order);
2629
2630 /* Fill remaining program header and finalize relocation related to dynamic
2631 linking. */
2632 if (phnum > 0) {
2633 fill_unloadable_phdr(phdr, phnum, interp, dynamic);
2634 if (dynamic) {
2635 dyninf.dynamic = dynamic;
2636 dyninf.dynstr = dynstr;
2637
2638 fill_dynamic(s1, &dyninf);
2639
2640 /* put in GOT the dynamic section address and relocate PLT */
2641 write32le(s1->got->data, dynamic->sh_addr);
2642 if (file_type == TCC_OUTPUT_EXE
2643 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
2644 || file_type == TCC_OUTPUT_DLL
2645 #endif
2646 )
2647 relocate_plt(s1);
2648
2649 /* relocate symbols in .dynsym now that final addresses are known */
2650 for_each_elem(s1->dynsym, 1, sym, ElfW(Sym)) {
2651 if (sym->st_shndx == SHN_UNDEF) {
2652 /* relocate to PLT if symbol corresponds to a PLT entry,
2653 but not if it's a weak symbol */
2654 if (ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
2655 sym->st_value = 0;
2656 else if (sym->st_value)
2657 sym->st_value += s1->plt->sh_addr;
2658 } else if (sym->st_shndx < SHN_LORESERVE) {
2659 /* do symbol relocation */
2660 sym->st_value += s1->sections[sym->st_shndx]->sh_addr;
2661 }
2662 }
2663 }
2664 }
2665
2666 /* if building executable or DLL, then relocate each section
2667 except the GOT which is already relocated */
2668 if (file_type != TCC_OUTPUT_OBJ) {
2669 ret = final_sections_reloc(s1);
2670 if (ret)
2671 goto the_end;
2672 }
2673
2674 /* Perform relocation to GOT or PLT entries */
2675 if (file_type == TCC_OUTPUT_EXE && s1->static_link)
2676 fill_got(s1);
2677
2678 /* Create the ELF file with name 'filename' */
2679 ret = tcc_write_elf_file(s1, filename, phnum, phdr, file_offset, sec_order);
2680 if (s1->do_strip) {
2681 int rc;
2682 const char *strip_cmd = "sstrip "; // super strip utility from ELFkickers
2683 const char *null_dev = " 2> /dev/null";
2684 char buf[1050];
2685 snprintf(buf, sizeof(buf), "%s%s%s", strip_cmd, filename, null_dev);
2686 rc = system(buf);
2687 if (rc)
2688 system(buf+1); // call a strip utility from binutils
2689 }
2690 the_end:
2691 tcc_free(s1->symtab_to_dynsym);
2692 tcc_free(sec_order);
2693 tcc_free(phdr);
2694 tcc_free(s1->sym_attrs);
2695 s1->sym_attrs = NULL;
2696 return ret;
2697 }
2698
2699 LIBTCCAPI int tcc_output_file(TCCState *s, const char *filename)
2700 {
2701 int ret;
2702 #ifdef TCC_TARGET_PE
2703 if (s->output_type != TCC_OUTPUT_OBJ) {
2704 ret = pe_output_file(s, filename);
2705 } else
2706 #endif
2707 ret = elf_output_file(s, filename);
2708 return ret;
2709 }
2710
2711 static void *load_data(int fd, unsigned long file_offset, unsigned long size)
2712 {
2713 void *data;
2714
2715 data = tcc_malloc(size);
2716 lseek(fd, file_offset, SEEK_SET);
2717 read(fd, data, size);
2718 return data;
2719 }
2720
2721 typedef struct SectionMergeInfo {
2722 Section *s; /* corresponding existing section */
2723 unsigned long offset; /* offset of the new section in the existing section */
2724 uint8_t new_section; /* true if section 's' was added */
2725 uint8_t link_once; /* true if link once section */
2726 } SectionMergeInfo;
2727
2728 /* load an object file and merge it with current files */
2729 /* XXX: handle correctly stab (debug) info */
2730 ST_FUNC int tcc_load_object_file(TCCState *s1,
2731 int fd, unsigned long file_offset)
2732 {
2733 ElfW(Ehdr) ehdr;
2734 ElfW(Shdr) *shdr, *sh;
2735 int size, i, j, offset, offseti, nb_syms, sym_index, ret;
2736 unsigned char *strsec, *strtab;
2737 int *old_to_new_syms;
2738 char *sh_name, *name;
2739 SectionMergeInfo *sm_table, *sm;
2740 ElfW(Sym) *sym, *symtab;
2741 ElfW_Rel *rel;
2742 Section *s;
2743
2744 int stab_index;
2745 int stabstr_index;
2746
2747 stab_index = stabstr_index = 0;
2748
2749 if (read(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr))
2750 goto fail1;
2751 if (ehdr.e_ident[0] != ELFMAG0 ||
2752 ehdr.e_ident[1] != ELFMAG1 ||
2753 ehdr.e_ident[2] != ELFMAG2 ||
2754 ehdr.e_ident[3] != ELFMAG3)
2755 goto fail1;
2756 /* test if object file */
2757 if (ehdr.e_type != ET_REL)
2758 goto fail1;
2759 /* test CPU specific stuff */
2760 if (ehdr.e_ident[5] != ELFDATA2LSB ||
2761 ehdr.e_machine != EM_TCC_TARGET) {
2762 fail1:
2763 tcc_error_noabort("invalid object file");
2764 return -1;
2765 }
2766 /* read sections */
2767 shdr = load_data(fd, file_offset + ehdr.e_shoff,
2768 sizeof(ElfW(Shdr)) * ehdr.e_shnum);
2769 sm_table = tcc_mallocz(sizeof(SectionMergeInfo) * ehdr.e_shnum);
2770
2771 /* load section names */
2772 sh = &shdr[ehdr.e_shstrndx];
2773 strsec = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2774
2775 /* load symtab and strtab */
2776 old_to_new_syms = NULL;
2777 symtab = NULL;
2778 strtab = NULL;
2779 nb_syms = 0;
2780 for(i = 1; i < ehdr.e_shnum; i++) {
2781 sh = &shdr[i];
2782 if (sh->sh_type == SHT_SYMTAB) {
2783 if (symtab) {
2784 tcc_error_noabort("object must contain only one symtab");
2785 fail:
2786 ret = -1;
2787 goto the_end;
2788 }
2789 nb_syms = sh->sh_size / sizeof(ElfW(Sym));
2790 symtab = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2791 sm_table[i].s = symtab_section;
2792
2793 /* now load strtab */
2794 sh = &shdr[sh->sh_link];
2795 strtab = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2796 }
2797 }
2798
2799 /* now examine each section and try to merge its content with the
2800 ones in memory */
2801 for(i = 1; i < ehdr.e_shnum; i++) {
2802 /* no need to examine section name strtab */
2803 if (i == ehdr.e_shstrndx)
2804 continue;
2805 sh = &shdr[i];
2806 sh_name = (char *) strsec + sh->sh_name;
2807 /* ignore sections types we do not handle */
2808 if (sh->sh_type != SHT_PROGBITS &&
2809 sh->sh_type != SHT_RELX &&
2810 #ifdef TCC_ARM_EABI
2811 sh->sh_type != SHT_ARM_EXIDX &&
2812 #endif
2813 sh->sh_type != SHT_NOBITS &&
2814 sh->sh_type != SHT_PREINIT_ARRAY &&
2815 sh->sh_type != SHT_INIT_ARRAY &&
2816 sh->sh_type != SHT_FINI_ARRAY &&
2817 strcmp(sh_name, ".stabstr")
2818 )
2819 continue;
2820 if (sh->sh_addralign < 1)
2821 sh->sh_addralign = 1;
2822 /* find corresponding section, if any */
2823 for(j = 1; j < s1->nb_sections;j++) {
2824 s = s1->sections[j];
2825 if (!strcmp(s->name, sh_name)) {
2826 if (!strncmp(sh_name, ".gnu.linkonce",
2827 sizeof(".gnu.linkonce") - 1)) {
2828 /* if a 'linkonce' section is already present, we
2829 do not add it again. It is a little tricky as
2830 symbols can still be defined in
2831 it. */
2832 sm_table[i].link_once = 1;
2833 goto next;
2834 } else {
2835 goto found;
2836 }
2837 }
2838 }
2839 /* not found: create new section */
2840 s = new_section(s1, sh_name, sh->sh_type, sh->sh_flags);
2841 /* take as much info as possible from the section. sh_link and
2842 sh_info will be updated later */
2843 s->sh_addralign = sh->sh_addralign;
2844 s->sh_entsize = sh->sh_entsize;
2845 sm_table[i].new_section = 1;
2846 found:
2847 if (sh->sh_type != s->sh_type) {
2848 tcc_error_noabort("invalid section type");
2849 goto fail;
2850 }
2851
2852 /* align start of section */
2853 offset = s->data_offset;
2854
2855 if (0 == strcmp(sh_name, ".stab")) {
2856 stab_index = i;
2857 goto no_align;
2858 }
2859 if (0 == strcmp(sh_name, ".stabstr")) {
2860 stabstr_index = i;
2861 goto no_align;
2862 }
2863
2864 size = sh->sh_addralign - 1;
2865 offset = (offset + size) & ~size;
2866 if (sh->sh_addralign > s->sh_addralign)
2867 s->sh_addralign = sh->sh_addralign;
2868 s->data_offset = offset;
2869 no_align:
2870 sm_table[i].offset = offset;
2871 sm_table[i].s = s;
2872 /* concatenate sections */
2873 size = sh->sh_size;
2874 if (sh->sh_type != SHT_NOBITS) {
2875 unsigned char *ptr;
2876 lseek(fd, file_offset + sh->sh_offset, SEEK_SET);
2877 ptr = section_ptr_add(s, size);
2878 read(fd, ptr, size);
2879 } else {
2880 s->data_offset += size;
2881 }
2882 next: ;
2883 }
2884
2885 /* gr relocate stab strings */
2886 if (stab_index && stabstr_index) {
2887 Stab_Sym *a, *b;
2888 unsigned o;
2889 s = sm_table[stab_index].s;
2890 a = (Stab_Sym *)(s->data + sm_table[stab_index].offset);
2891 b = (Stab_Sym *)(s->data + s->data_offset);
2892 o = sm_table[stabstr_index].offset;
2893 while (a < b)
2894 a->n_strx += o, a++;
2895 }
2896
2897 /* second short pass to update sh_link and sh_info fields of new
2898 sections */
2899 for(i = 1; i < ehdr.e_shnum; i++) {
2900 s = sm_table[i].s;
2901 if (!s || !sm_table[i].new_section)
2902 continue;
2903 sh = &shdr[i];
2904 if (sh->sh_link > 0)
2905 s->link = sm_table[sh->sh_link].s;
2906 if (sh->sh_type == SHT_RELX) {
2907 s->sh_info = sm_table[sh->sh_info].s->sh_num;
2908 /* update backward link */
2909 s1->sections[s->sh_info]->reloc = s;
2910 }
2911 }
2912 sm = sm_table;
2913
2914 /* resolve symbols */
2915 old_to_new_syms = tcc_mallocz(nb_syms * sizeof(int));
2916
2917 sym = symtab + 1;
2918 for(i = 1; i < nb_syms; i++, sym++) {
2919 if (sym->st_shndx != SHN_UNDEF &&
2920 sym->st_shndx < SHN_LORESERVE) {
2921 sm = &sm_table[sym->st_shndx];
2922 if (sm->link_once) {
2923 /* if a symbol is in a link once section, we use the
2924 already defined symbol. It is very important to get
2925 correct relocations */
2926 if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
2927 name = (char *) strtab + sym->st_name;
2928 sym_index = find_elf_sym(symtab_section, name);
2929 if (sym_index)
2930 old_to_new_syms[i] = sym_index;
2931 }
2932 continue;
2933 }
2934 /* if no corresponding section added, no need to add symbol */
2935 if (!sm->s)
2936 continue;
2937 /* convert section number */
2938 sym->st_shndx = sm->s->sh_num;
2939 /* offset value */
2940 sym->st_value += sm->offset;
2941 }
2942 /* add symbol */
2943 name = (char *) strtab + sym->st_name;
2944 sym_index = add_elf_sym(symtab_section, sym->st_value, sym->st_size,
2945 sym->st_info, sym->st_other,
2946 sym->st_shndx, name);
2947 old_to_new_syms[i] = sym_index;
2948 }
2949
2950 /* third pass to patch relocation entries */
2951 for(i = 1; i < ehdr.e_shnum; i++) {
2952 s = sm_table[i].s;
2953 if (!s)
2954 continue;
2955 sh = &shdr[i];
2956 offset = sm_table[i].offset;
2957 switch(s->sh_type) {
2958 case SHT_RELX:
2959 /* take relocation offset information */
2960 offseti = sm_table[sh->sh_info].offset;
2961 for_each_elem(s, (offset / sizeof(*rel)), rel, ElfW_Rel) {
2962 int type;
2963 unsigned sym_index;
2964 /* convert symbol index */
2965 type = ELFW(R_TYPE)(rel->r_info);
2966 sym_index = ELFW(R_SYM)(rel->r_info);
2967 /* NOTE: only one symtab assumed */
2968 if (sym_index >= nb_syms)
2969 goto invalid_reloc;
2970 sym_index = old_to_new_syms[sym_index];
2971 /* ignore link_once in rel section. */
2972 if (!sym_index && !sm->link_once
2973 #ifdef TCC_TARGET_ARM
2974 && type != R_ARM_V4BX
2975 #endif
2976 ) {
2977 invalid_reloc:
2978 tcc_error_noabort("Invalid relocation entry [%2d] '%s' @ %.8x",
2979 i, strsec + sh->sh_name, rel->r_offset);
2980 goto fail;
2981 }
2982 rel->r_info = ELFW(R_INFO)(sym_index, type);
2983 /* offset the relocation offset */
2984 rel->r_offset += offseti;
2985 #ifdef TCC_TARGET_ARM
2986 /* Jumps and branches from a Thumb code to a PLT entry need
2987 special handling since PLT entries are ARM code.
2988 Unconditional bl instructions referencing PLT entries are
2989 handled by converting these instructions into blx
2990 instructions. Other case of instructions referencing a PLT
2991 entry require to add a Thumb stub before the PLT entry to
2992 switch to ARM mode. We set bit plt_thumb_stub of the
2993 attribute of a symbol to indicate such a case. */
2994 if (type == R_ARM_THM_JUMP24)
2995 alloc_sym_attr(s1, sym_index)->plt_thumb_stub = 1;
2996 #endif
2997 }
2998 break;
2999 default:
3000 break;
3001 }
3002 }
3003
3004 ret = 0;
3005 the_end:
3006 tcc_free(symtab);
3007 tcc_free(strtab);
3008 tcc_free(old_to_new_syms);
3009 tcc_free(sm_table);
3010 tcc_free(strsec);
3011 tcc_free(shdr);
3012 return ret;
3013 }
3014
3015 typedef struct ArchiveHeader {
3016 char ar_name[16]; /* name of this member */
3017 char ar_date[12]; /* file mtime */
3018 char ar_uid[6]; /* owner uid; printed as decimal */
3019 char ar_gid[6]; /* owner gid; printed as decimal */
3020 char ar_mode[8]; /* file mode, printed as octal */
3021 char ar_size[10]; /* file size, printed as decimal */
3022 char ar_fmag[2]; /* should contain ARFMAG */
3023 } ArchiveHeader;
3024
3025 static int get_be32(const uint8_t *b)
3026 {
3027 return b[3] | (b[2] << 8) | (b[1] << 16) | (b[0] << 24);
3028 }
3029
3030 /* load only the objects which resolve undefined symbols */
3031 static int tcc_load_alacarte(TCCState *s1, int fd, int size)
3032 {
3033 int i, bound, nsyms, sym_index, off, ret;
3034 uint8_t *data;
3035 const char *ar_names, *p;
3036 const uint8_t *ar_index;
3037 ElfW(Sym) *sym;
3038
3039 data = tcc_malloc(size);
3040 if (read(fd, data, size) != size)
3041 goto fail;
3042 nsyms = get_be32(data);
3043 ar_index = data + 4;
3044 ar_names = (char *) ar_index + nsyms * 4;
3045
3046 do {
3047 bound = 0;
3048 for(p = ar_names, i = 0; i < nsyms; i++, p += strlen(p)+1) {
3049 sym_index = find_elf_sym(symtab_section, p);
3050 if(sym_index) {
3051 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
3052 if(sym->st_shndx == SHN_UNDEF) {
3053 off = get_be32(ar_index + i * 4) + sizeof(ArchiveHeader);
3054 ++bound;
3055 lseek(fd, off, SEEK_SET);
3056 if(tcc_load_object_file(s1, fd, off) < 0) {
3057 fail:
3058 ret = -1;
3059 goto the_end;
3060 }
3061 }
3062 }
3063 }
3064 } while(bound);
3065 ret = 0;
3066 the_end:
3067 tcc_free(data);
3068 return ret;
3069 }
3070
3071 /* load a '.a' file */
3072 ST_FUNC int tcc_load_archive(TCCState *s1, int fd)
3073 {
3074 ArchiveHeader hdr;
3075 char ar_size[11];
3076 char ar_name[17];
3077 char magic[8];
3078 int size, len, i;
3079 unsigned long file_offset;
3080
3081 /* skip magic which was already checked */
3082 read(fd, magic, sizeof(magic));
3083
3084 for(;;) {
3085 len = read(fd, &hdr, sizeof(hdr));
3086 if (len == 0)
3087 break;
3088 if (len != sizeof(hdr)) {
3089 tcc_error_noabort("invalid archive");
3090 return -1;
3091 }
3092 memcpy(ar_size, hdr.ar_size, sizeof(hdr.ar_size));
3093 ar_size[sizeof(hdr.ar_size)] = '\0';
3094 size = strtol(ar_size, NULL, 0);
3095 memcpy(ar_name, hdr.ar_name, sizeof(hdr.ar_name));
3096 for(i = sizeof(hdr.ar_name) - 1; i >= 0; i--) {
3097 if (ar_name[i] != ' ')
3098 break;
3099 }
3100 ar_name[i + 1] = '\0';
3101 file_offset = lseek(fd, 0, SEEK_CUR);
3102 /* align to even */
3103 size = (size + 1) & ~1;
3104 if (!strcmp(ar_name, "/")) {
3105 /* coff symbol table : we handle it */
3106 if(s1->alacarte_link)
3107 return tcc_load_alacarte(s1, fd, size);
3108 } else if (!strcmp(ar_name, "//") ||
3109 !strcmp(ar_name, "__.SYMDEF") ||
3110 !strcmp(ar_name, "__.SYMDEF/") ||
3111 !strcmp(ar_name, "ARFILENAMES/")) {
3112 /* skip symbol table or archive names */
3113 } else {
3114 if (tcc_load_object_file(s1, fd, file_offset) < 0)
3115 return -1;
3116 }
3117 lseek(fd, file_offset + size, SEEK_SET);
3118 }
3119 return 0;
3120 }
3121
3122 #ifndef TCC_TARGET_PE
3123 /* load a DLL and all referenced DLLs. 'level = 0' means that the DLL
3124 is referenced by the user (so it should be added as DT_NEEDED in
3125 the generated ELF file) */
3126 ST_FUNC int tcc_load_dll(TCCState *s1, int fd, const char *filename, int level)
3127 {
3128 ElfW(Ehdr) ehdr;
3129 ElfW(Shdr) *shdr, *sh, *sh1;
3130 int i, j, nb_syms, nb_dts, sym_bind, ret;
3131 ElfW(Sym) *sym, *dynsym;
3132 ElfW(Dyn) *dt, *dynamic;
3133 unsigned char *dynstr;
3134 const char *name, *soname;
3135 DLLReference *dllref;
3136
3137 read(fd, &ehdr, sizeof(ehdr));
3138
3139 /* test CPU specific stuff */
3140 if (ehdr.e_ident[5] != ELFDATA2LSB ||
3141 ehdr.e_machine != EM_TCC_TARGET) {
3142 tcc_error_noabort("bad architecture");
3143 return -1;
3144 }
3145
3146 /* read sections */
3147 shdr = load_data(fd, ehdr.e_shoff, sizeof(ElfW(Shdr)) * ehdr.e_shnum);
3148
3149 /* load dynamic section and dynamic symbols */
3150 nb_syms = 0;
3151 nb_dts = 0;
3152 dynamic = NULL;
3153 dynsym = NULL; /* avoid warning */
3154 dynstr = NULL; /* avoid warning */
3155 for(i = 0, sh = shdr; i < ehdr.e_shnum; i++, sh++) {
3156 switch(sh->sh_type) {
3157 case SHT_DYNAMIC:
3158 nb_dts = sh->sh_size / sizeof(ElfW(Dyn));
3159 dynamic = load_data(fd, sh->sh_offset, sh->sh_size);
3160 break;
3161 case SHT_DYNSYM:
3162 nb_syms = sh->sh_size / sizeof(ElfW(Sym));
3163 dynsym = load_data(fd, sh->sh_offset, sh->sh_size);
3164 sh1 = &shdr[sh->sh_link];
3165 dynstr = load_data(fd, sh1->sh_offset, sh1->sh_size);
3166 break;
3167 default:
3168 break;
3169 }
3170 }
3171
3172 /* compute the real library name */
3173 soname = tcc_basename(filename);
3174
3175 for(i = 0, dt = dynamic; i < nb_dts; i++, dt++) {
3176 if (dt->d_tag == DT_SONAME) {
3177 soname = (char *) dynstr + dt->d_un.d_val;
3178 }
3179 }
3180
3181 /* if the dll is already loaded, do not load it */
3182 for(i = 0; i < s1->nb_loaded_dlls; i++) {
3183 dllref = s1->loaded_dlls[i];
3184 if (!strcmp(soname, dllref->name)) {
3185 /* but update level if needed */
3186 if (level < dllref->level)
3187 dllref->level = level;
3188 ret = 0;
3189 goto the_end;
3190 }
3191 }
3192
3193 /* add the dll and its level */
3194 dllref = tcc_mallocz(sizeof(DLLReference) + strlen(soname));
3195 dllref->level = level;
3196 strcpy(dllref->name, soname);
3197 dynarray_add((void ***)&s1->loaded_dlls, &s1->nb_loaded_dlls, dllref);
3198
3199 /* add dynamic symbols in dynsym_section */
3200 for(i = 1, sym = dynsym + 1; i < nb_syms; i++, sym++) {
3201 sym_bind = ELFW(ST_BIND)(sym->st_info);
3202 if (sym_bind == STB_LOCAL)
3203 continue;
3204 name = (char *) dynstr + sym->st_name;
3205 add_elf_sym(s1->dynsymtab_section, sym->st_value, sym->st_size,
3206 sym->st_info, sym->st_other, sym->st_shndx, name);
3207 }
3208
3209 /* load all referenced DLLs */
3210 for(i = 0, dt = dynamic; i < nb_dts; i++, dt++) {
3211 switch(dt->d_tag) {
3212 case DT_NEEDED:
3213 name = (char *) dynstr + dt->d_un.d_val;
3214 for(j = 0; j < s1->nb_loaded_dlls; j++) {
3215 dllref = s1->loaded_dlls[j];
3216 if (!strcmp(name, dllref->name))
3217 goto already_loaded;
3218 }
3219 if (tcc_add_dll(s1, name, AFF_REFERENCED_DLL) < 0) {
3220 tcc_error_noabort("referenced dll '%s' not found", name);
3221 ret = -1;
3222 goto the_end;
3223 }
3224 already_loaded:
3225 break;
3226 }
3227 }
3228 ret = 0;
3229 the_end:
3230 tcc_free(dynstr);
3231 tcc_free(dynsym);
3232 tcc_free(dynamic);
3233 tcc_free(shdr);
3234 return ret;
3235 }
3236
3237 #define LD_TOK_NAME 256
3238 #define LD_TOK_EOF (-1)
3239
3240 /* return next ld script token */
3241 static int ld_next(TCCState *s1, char *name, int name_size)
3242 {
3243 int c;
3244 char *q;
3245
3246 redo:
3247 switch(ch) {
3248 case ' ':
3249 case '\t':
3250 case '\f':
3251 case '\v':
3252 case '\r':
3253 case '\n':
3254 inp();
3255 goto redo;
3256 case '/':
3257 minp();
3258 if (ch == '*') {
3259 file->buf_ptr = parse_comment(file->buf_ptr);
3260 ch = file->buf_ptr[0];
3261 goto redo;
3262 } else {
3263 q = name;
3264 *q++ = '/';
3265 goto parse_name;
3266 }
3267 break;
3268 case '\\':
3269 ch = handle_eob();
3270 if (ch != '\\')
3271 goto redo;
3272 /* fall through */
3273 /* case 'a' ... 'z': */
3274 case 'a':
3275 case 'b':
3276 case 'c':
3277 case 'd':
3278 case 'e':
3279 case 'f':
3280 case 'g':
3281 case 'h':
3282 case 'i':
3283 case 'j':
3284 case 'k':
3285 case 'l':
3286 case 'm':
3287 case 'n':
3288 case 'o':
3289 case 'p':
3290 case 'q':
3291 case 'r':
3292 case 's':
3293 case 't':
3294 case 'u':
3295 case 'v':
3296 case 'w':
3297 case 'x':
3298 case 'y':
3299 case 'z':
3300 /* case 'A' ... 'z': */
3301 case 'A':
3302 case 'B':
3303 case 'C':
3304 case 'D':
3305 case 'E':
3306 case 'F':
3307 case 'G':
3308 case 'H':
3309 case 'I':
3310 case 'J':
3311 case 'K':
3312 case 'L':
3313 case 'M':
3314 case 'N':
3315 case 'O':
3316 case 'P':
3317 case 'Q':
3318 case 'R':
3319 case 'S':
3320 case 'T':
3321 case 'U':
3322 case 'V':
3323 case 'W':
3324 case 'X':
3325 case 'Y':
3326 case 'Z':
3327 case '_':
3328 case '.':
3329 case '$':
3330 case '~':
3331 q = name;
3332 parse_name:
3333 for(;;) {
3334 if (!((ch >= 'a' && ch <= 'z') ||
3335 (ch >= 'A' && ch <= 'Z') ||
3336 (ch >= '0' && ch <= '9') ||
3337 strchr("/.-_+=$:\\,~", ch)))
3338 break;
3339 if ((q - name) < name_size - 1) {
3340 *q++ = ch;
3341 }
3342 minp();
3343 }
3344 *q = '\0';
3345 c = LD_TOK_NAME;
3346 break;
3347 case CH_EOF:
3348 c = LD_TOK_EOF;
3349 break;
3350 default:
3351 c = ch;
3352 inp();
3353 break;
3354 }
3355 return c;
3356 }
3357
3358 static int ld_add_file(TCCState *s1, const char filename[])
3359 {
3360 int ret;
3361
3362 ret = tcc_add_file_internal(s1, filename, 0, TCC_FILETYPE_BINARY);
3363 if (ret)
3364 ret = tcc_add_dll(s1, filename, 0);
3365 return ret;
3366 }
3367
3368 static inline int new_undef_syms(void)
3369 {
3370 int ret = 0;
3371 ret = new_undef_sym;
3372 new_undef_sym = 0;
3373 return ret;
3374 }
3375
3376 static int ld_add_file_list(TCCState *s1, const char *cmd, int as_needed)
3377 {
3378 char filename[1024], libname[1024];
3379 int t, group, nblibs = 0, ret = 0;
3380 char **libs = NULL;
3381
3382 group = !strcmp(cmd, "GROUP");
3383 if (!as_needed)
3384 new_undef_syms();
3385 t = ld_next(s1, filename, sizeof(filename));
3386 if (t != '(')
3387 expect("(");
3388 t = ld_next(s1, filename, sizeof(filename));
3389 for(;;) {
3390 libname[0] = '\0';
3391 if (t == LD_TOK_EOF) {
3392 tcc_error_noabort("unexpected end of file");
3393 ret = -1;
3394 goto lib_parse_error;
3395 } else if (t == ')') {
3396 break;
3397 } else if (t == '-') {
3398 t = ld_next(s1, filename, sizeof(filename));
3399 if ((t != LD_TOK_NAME) || (filename[0] != 'l')) {
3400 tcc_error_noabort("library name expected");
3401 ret = -1;
3402 goto lib_parse_error;
3403 }
3404 pstrcpy(libname, sizeof libname, &filename[1]);
3405 if (s1->static_link) {
3406 snprintf(filename, sizeof filename, "lib%s.a", libname);
3407 } else {
3408 snprintf(filename, sizeof filename, "lib%s.so", libname);
3409 }
3410 } else if (t != LD_TOK_NAME) {
3411 tcc_error_noabort("filename expected");
3412 ret = -1;
3413 goto lib_parse_error;
3414 }
3415 if (!strcmp(filename, "AS_NEEDED")) {
3416 ret = ld_add_file_list(s1, cmd, 1);
3417 if (ret)
3418 goto lib_parse_error;
3419 } else {
3420 /* TODO: Implement AS_NEEDED support. Ignore it for now */
3421 if (!as_needed) {
3422 ret = ld_add_file(s1, filename);
3423 if (ret)
3424 goto lib_parse_error;
3425 if (group) {
3426 /* Add the filename *and* the libname to avoid future conversions */
3427 dynarray_add((void ***) &libs, &nblibs, tcc_strdup(filename));
3428 if (libname[0] != '\0')
3429 dynarray_add((void ***) &libs, &nblibs, tcc_strdup(libname));
3430 }
3431 }
3432 }
3433 t = ld_next(s1, filename, sizeof(filename));
3434 if (t == ',') {
3435 t = ld_next(s1, filename, sizeof(filename));
3436 }
3437 }
3438 if (group && !as_needed) {
3439 while (new_undef_syms()) {
3440 int i;
3441
3442 for (i = 0; i < nblibs; i ++)
3443 ld_add_file(s1, libs[i]);
3444 }
3445 }
3446 lib_parse_error:
3447 dynarray_reset(&libs, &nblibs);
3448 return ret;
3449 }
3450
3451 /* interpret a subset of GNU ldscripts to handle the dummy libc.so
3452 files */
3453 ST_FUNC int tcc_load_ldscript(TCCState *s1)
3454 {
3455 char cmd[64];
3456 char filename[1024];
3457 int t, ret;
3458
3459 ch = handle_eob();
3460 for(;;) {
3461 t = ld_next(s1, cmd, sizeof(cmd));
3462 if (t == LD_TOK_EOF)
3463 return 0;
3464 else if (t != LD_TOK_NAME)
3465 return -1;
3466 if (!strcmp(cmd, "INPUT") ||
3467 !strcmp(cmd, "GROUP")) {
3468 ret = ld_add_file_list(s1, cmd, 0);
3469 if (ret)
3470 return ret;
3471 } else if (!strcmp(cmd, "OUTPUT_FORMAT") ||
3472 !strcmp(cmd, "TARGET")) {
3473 /* ignore some commands */
3474 t = ld_next(s1, cmd, sizeof(cmd));
3475 if (t != '(')
3476 expect("(");
3477 for(;;) {
3478 t = ld_next(s1, filename, sizeof(filename));
3479 if (t == LD_TOK_EOF) {
3480 tcc_error_noabort("unexpected end of file");
3481 return -1;
3482 } else if (t == ')') {
3483 break;
3484 }
3485 }
3486 } else {
3487 return -1;
3488 }
3489 }
3490 return 0;
3491 }
3492 #endif /* !TCC_TARGET_PE */
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