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tccpp: cleanup #include_next
[tinycc.git] / tccelf.c
blob7b29bd6e7cbc7c448c9581dd90f2e6ec84ac9421
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 +
1965 (read32le(p) | (uint64_t)read32le(p + 4) << 32);
1966 uint32_t off = (addr >> 12) - (pc >> 12);
1967 if ((off + ((uint32_t)1 << 20)) >> 21)
1968 tcc_error("Failed relocating PLT (off=0x%lx, addr=0x%lx, pc=0x%lx)", off, addr, pc);
1969 write32le(p, (0x90000010 | // adrp x16,...
1970 (off & 0x1ffffc) << 3 | (off & 3) << 29));
1971 write32le(p + 4, (0xf9400211 | // ldr x17,[x16,#...]
1972 (addr & 0xff8) << 7));
1973 write32le(p + 8, (0x91000210 | // add x16,x16,#...
1974 (addr & 0xfff) << 10));
1975 write32le(p + 12, 0xd61f0220); // br x17
1976 p += 16;
1977 }
1978 #elif defined(TCC_TARGET_C67)
1979 /* XXX: TODO */
1980 #else
1981 #error unsupported CPU
1982 #endif
1983 }
1984 }
1985
1986 /* Allocate strings for section names and decide if an unallocated section
1987 should be output.
1988
1989 NOTE: the strsec section comes last, so its size is also correct ! */
1990 static void alloc_sec_names(TCCState *s1, int file_type, Section *strsec)
1991 {
1992 int i;
1993 Section *s;
1994
1995 /* Allocate strings for section names */
1996 for(i = 1; i < s1->nb_sections; i++) {
1997 s = s1->sections[i];
1998 s->sh_name = put_elf_str(strsec, s->name);
1999 /* when generating a DLL, we include relocations but we may
2000 patch them */
2001 if (file_type == TCC_OUTPUT_DLL &&
2002 s->sh_type == SHT_RELX &&
2003 !(s->sh_flags & SHF_ALLOC)) {
2004 /* gr: avoid bogus relocs for empty (debug) sections */
2005 if (s1->sections[s->sh_info]->sh_flags & SHF_ALLOC)
2006 prepare_dynamic_rel(s1, s);
2007 else if (s1->do_debug)
2008 s->sh_size = s->data_offset;
2009 } else if (s1->do_debug ||
2010 file_type == TCC_OUTPUT_OBJ ||
2011 file_type == TCC_OUTPUT_EXE ||
2012 (s->sh_flags & SHF_ALLOC) ||
2013 i == (s1->nb_sections - 1)) {
2014 /* we output all sections if debug or object file */
2015 s->sh_size = s->data_offset;
2016 }
2017 }
2018 }
2019
2020 /* Info to be copied in dynamic section */
2021 struct dyn_inf {
2022 Section *dynamic;
2023 Section *dynstr;
2024 unsigned long dyn_rel_off;
2025 addr_t rel_addr;
2026 addr_t rel_size;
2027 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2028 addr_t bss_addr;
2029 addr_t bss_size;
2030 #endif
2031 };
2032
2033 /* Assign sections to segments and decide how are sections laid out when loaded
2034 in memory. This function also fills corresponding program headers. */
2035 static int layout_sections(TCCState *s1, ElfW(Phdr) *phdr, int phnum,
2036 Section *interp, Section* strsec,
2037 struct dyn_inf *dyninf, int *sec_order)
2038 {
2039 int i, j, k, file_type, sh_order_index, file_offset;
2040 unsigned long s_align;
2041 long long tmp;
2042 addr_t addr;
2043 ElfW(Phdr) *ph;
2044 Section *s;
2045
2046 file_type = s1->output_type;
2047 sh_order_index = 1;
2048 file_offset = 0;
2049 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF)
2050 file_offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr));
2051 s_align = ELF_PAGE_SIZE;
2052 if (s1->section_align)
2053 s_align = s1->section_align;
2054
2055 if (phnum > 0) {
2056 if (s1->has_text_addr) {
2057 int a_offset, p_offset;
2058 addr = s1->text_addr;
2059 /* we ensure that (addr % ELF_PAGE_SIZE) == file_offset %
2060 ELF_PAGE_SIZE */
2061 a_offset = (int) (addr & (s_align - 1));
2062 p_offset = file_offset & (s_align - 1);
2063 if (a_offset < p_offset)
2064 a_offset += s_align;
2065 file_offset += (a_offset - p_offset);
2066 } else {
2067 if (file_type == TCC_OUTPUT_DLL)
2068 addr = 0;
2069 else
2070 addr = ELF_START_ADDR;
2071 /* compute address after headers */
2072 addr += (file_offset & (s_align - 1));
2073 }
2074
2075 ph = &phdr[0];
2076 /* Leave one program headers for the program interpreter and one for
2077 the program header table itself if needed. These are done later as
2078 they require section layout to be done first. */
2079 if (interp)
2080 ph += 1 + HAVE_PHDR;
2081
2082 /* dynamic relocation table information, for .dynamic section */
2083 dyninf->rel_addr = dyninf->rel_size = 0;
2084 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2085 dyninf->bss_addr = dyninf->bss_size = 0;
2086 #endif
2087
2088 for(j = 0; j < 2; j++) {
2089 ph->p_type = PT_LOAD;
2090 if (j == 0)
2091 ph->p_flags = PF_R | PF_X;
2092 else
2093 ph->p_flags = PF_R | PF_W;
2094 ph->p_align = s_align;
2095
2096 /* Decide the layout of sections loaded in memory. This must
2097 be done before program headers are filled since they contain
2098 info about the layout. We do the following ordering: interp,
2099 symbol tables, relocations, progbits, nobits */
2100 /* XXX: do faster and simpler sorting */
2101 for(k = 0; k < 5; k++) {
2102 for(i = 1; i < s1->nb_sections; i++) {
2103 s = s1->sections[i];
2104 /* compute if section should be included */
2105 if (j == 0) {
2106 if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) !=
2107 SHF_ALLOC)
2108 continue;
2109 } else {
2110 if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) !=
2111 (SHF_ALLOC | SHF_WRITE))
2112 continue;
2113 }
2114 if (s == interp) {
2115 if (k != 0)
2116 continue;
2117 } else if (s->sh_type == SHT_DYNSYM ||
2118 s->sh_type == SHT_STRTAB ||
2119 s->sh_type == SHT_HASH) {
2120 if (k != 1)
2121 continue;
2122 } else if (s->sh_type == SHT_RELX) {
2123 if (k != 2)
2124 continue;
2125 } else if (s->sh_type == SHT_NOBITS) {
2126 if (k != 4)
2127 continue;
2128 } else {
2129 if (k != 3)
2130 continue;
2131 }
2132 sec_order[sh_order_index++] = i;
2133
2134 /* section matches: we align it and add its size */
2135 tmp = addr;
2136 addr = (addr + s->sh_addralign - 1) &
2137 ~(s->sh_addralign - 1);
2138 file_offset += (int) ( addr - tmp );
2139 s->sh_offset = file_offset;
2140 s->sh_addr = addr;
2141
2142 /* update program header infos */
2143 if (ph->p_offset == 0) {
2144 ph->p_offset = file_offset;
2145 ph->p_vaddr = addr;
2146 ph->p_paddr = ph->p_vaddr;
2147 }
2148 /* update dynamic relocation infos */
2149 if (s->sh_type == SHT_RELX) {
2150 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2151 if (!strcmp(strsec->data + s->sh_name, ".rel.got")) {
2152 dyninf->rel_addr = addr;
2153 dyninf->rel_size += s->sh_size; /* XXX only first rel. */
2154 }
2155 if (!strcmp(strsec->data + s->sh_name, ".rel.bss")) {
2156 dyninf->bss_addr = addr;
2157 dyninf->bss_size = s->sh_size; /* XXX only first rel. */
2158 }
2159 #else
2160 if (dyninf->rel_size == 0)
2161 dyninf->rel_addr = addr;
2162 dyninf->rel_size += s->sh_size;
2163 #endif
2164 }
2165 addr += s->sh_size;
2166 if (s->sh_type != SHT_NOBITS)
2167 file_offset += s->sh_size;
2168 }
2169 }
2170 if (j == 0) {
2171 /* Make the first PT_LOAD segment include the program
2172 headers itself (and the ELF header as well), it'll
2173 come out with same memory use but will make various
2174 tools like binutils strip work better. */
2175 ph->p_offset &= ~(ph->p_align - 1);
2176 ph->p_vaddr &= ~(ph->p_align - 1);
2177 ph->p_paddr &= ~(ph->p_align - 1);
2178 }
2179 ph->p_filesz = file_offset - ph->p_offset;
2180 ph->p_memsz = addr - ph->p_vaddr;
2181 ph++;
2182 if (j == 0) {
2183 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF) {
2184 /* if in the middle of a page, we duplicate the page in
2185 memory so that one copy is RX and the other is RW */
2186 if ((addr & (s_align - 1)) != 0)
2187 addr += s_align;
2188 } else {
2189 addr = (addr + s_align - 1) & ~(s_align - 1);
2190 file_offset = (file_offset + s_align - 1) & ~(s_align - 1);
2191 }
2192 }
2193 }
2194 }
2195
2196 /* all other sections come after */
2197 for(i = 1; i < s1->nb_sections; i++) {
2198 s = s1->sections[i];
2199 if (phnum > 0 && (s->sh_flags & SHF_ALLOC))
2200 continue;
2201 sec_order[sh_order_index++] = i;
2202
2203 file_offset = (file_offset + s->sh_addralign - 1) &
2204 ~(s->sh_addralign - 1);
2205 s->sh_offset = file_offset;
2206 if (s->sh_type != SHT_NOBITS)
2207 file_offset += s->sh_size;
2208 }
2209
2210 return file_offset;
2211 }
2212
2213 static void fill_unloadable_phdr(ElfW(Phdr) *phdr, int phnum, Section *interp,
2214 Section *dynamic)
2215 {
2216 ElfW(Phdr) *ph;
2217
2218 /* if interpreter, then add corresponding program header */
2219 if (interp) {
2220 ph = &phdr[0];
2221
2222 if (HAVE_PHDR)
2223 {
2224 int len = phnum * sizeof(ElfW(Phdr));
2225
2226 ph->p_type = PT_PHDR;
2227 ph->p_offset = sizeof(ElfW(Ehdr));
2228 ph->p_vaddr = interp->sh_addr - len;
2229 ph->p_paddr = ph->p_vaddr;
2230 ph->p_filesz = ph->p_memsz = len;
2231 ph->p_flags = PF_R | PF_X;
2232 ph->p_align = 4; /* interp->sh_addralign; */
2233 ph++;
2234 }
2235
2236 ph->p_type = PT_INTERP;
2237 ph->p_offset = interp->sh_offset;
2238 ph->p_vaddr = interp->sh_addr;
2239 ph->p_paddr = ph->p_vaddr;
2240 ph->p_filesz = interp->sh_size;
2241 ph->p_memsz = interp->sh_size;
2242 ph->p_flags = PF_R;
2243 ph->p_align = interp->sh_addralign;
2244 }
2245
2246 /* if dynamic section, then add corresponding program header */
2247 if (dynamic) {
2248 ph = &phdr[phnum - 1];
2249
2250 ph->p_type = PT_DYNAMIC;
2251 ph->p_offset = dynamic->sh_offset;
2252 ph->p_vaddr = dynamic->sh_addr;
2253 ph->p_paddr = ph->p_vaddr;
2254 ph->p_filesz = dynamic->sh_size;
2255 ph->p_memsz = dynamic->sh_size;
2256 ph->p_flags = PF_R | PF_W;
2257 ph->p_align = dynamic->sh_addralign;
2258 }
2259 }
2260
2261 /* Fill the dynamic section with tags describing the address and size of
2262 sections */
2263 static void fill_dynamic(TCCState *s1, struct dyn_inf *dyninf)
2264 {
2265 Section *dynamic;
2266
2267 dynamic = dyninf->dynamic;
2268
2269 /* put dynamic section entries */
2270 dynamic->data_offset = dyninf->dyn_rel_off;
2271 put_dt(dynamic, DT_HASH, s1->dynsym->hash->sh_addr);
2272 put_dt(dynamic, DT_STRTAB, dyninf->dynstr->sh_addr);
2273 put_dt(dynamic, DT_SYMTAB, s1->dynsym->sh_addr);
2274 put_dt(dynamic, DT_STRSZ, dyninf->dynstr->data_offset);
2275 put_dt(dynamic, DT_SYMENT, sizeof(ElfW(Sym)));
2276 #if defined(TCC_TARGET_ARM64) || defined(TCC_TARGET_X86_64)
2277 put_dt(dynamic, DT_RELA, dyninf->rel_addr);
2278 put_dt(dynamic, DT_RELASZ, dyninf->rel_size);
2279 put_dt(dynamic, DT_RELAENT, sizeof(ElfW_Rel));
2280 #else
2281 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2282 put_dt(dynamic, DT_PLTGOT, s1->got->sh_addr);
2283 put_dt(dynamic, DT_PLTRELSZ, dyninf->rel_size);
2284 put_dt(dynamic, DT_JMPREL, dyninf->rel_addr);
2285 put_dt(dynamic, DT_PLTREL, DT_REL);
2286 put_dt(dynamic, DT_REL, dyninf->bss_addr);
2287 put_dt(dynamic, DT_RELSZ, dyninf->bss_size);
2288 #else
2289 put_dt(dynamic, DT_REL, dyninf->rel_addr);
2290 put_dt(dynamic, DT_RELSZ, dyninf->rel_size);
2291 put_dt(dynamic, DT_RELENT, sizeof(ElfW_Rel));
2292 #endif
2293 #endif
2294 if (s1->do_debug)
2295 put_dt(dynamic, DT_DEBUG, 0);
2296 put_dt(dynamic, DT_NULL, 0);
2297 }
2298
2299 /* Relocate remaining sections and symbols (that is those not related to
2300 dynamic linking) */
2301 static int final_sections_reloc(TCCState *s1)
2302 {
2303 int i;
2304 Section *s;
2305
2306 relocate_syms(s1, 0);
2307
2308 if (s1->nb_errors != 0)
2309 return -1;
2310
2311 /* relocate sections */
2312 /* XXX: ignore sections with allocated relocations ? */
2313 for(i = 1; i < s1->nb_sections; i++) {
2314 s = s1->sections[i];
2315 #ifdef TCC_TARGET_I386
2316 if (s->reloc && s != s1->got && (s->sh_flags & SHF_ALLOC)) //gr
2317 /* On X86 gdb 7.3 works in any case but gdb 6.6 will crash if SHF_ALLOC
2318 checking is removed */
2319 #else
2320 if (s->reloc && s != s1->got)
2321 /* On X86_64 gdb 7.3 will crash if SHF_ALLOC checking is present */
2322 #endif
2323 relocate_section(s1, s);
2324 }
2325
2326 /* relocate relocation entries if the relocation tables are
2327 allocated in the executable */
2328 for(i = 1; i < s1->nb_sections; i++) {
2329 s = s1->sections[i];
2330 if ((s->sh_flags & SHF_ALLOC) &&
2331 s->sh_type == SHT_RELX) {
2332 relocate_rel(s1, s);
2333 }
2334 }
2335 return 0;
2336 }
2337
2338 /* Create an ELF file on disk.
2339 This function handle ELF specific layout requirements */
2340 static void tcc_output_elf(TCCState *s1, FILE *f, int phnum, ElfW(Phdr) *phdr,
2341 int file_offset, int *sec_order)
2342 {
2343 int i, shnum, offset, size, file_type;
2344 Section *s;
2345 ElfW(Ehdr) ehdr;
2346 ElfW(Shdr) shdr, *sh;
2347
2348 file_type = s1->output_type;
2349 shnum = s1->nb_sections;
2350
2351 memset(&ehdr, 0, sizeof(ehdr));
2352
2353 if (phnum > 0) {
2354 ehdr.e_phentsize = sizeof(ElfW(Phdr));
2355 ehdr.e_phnum = phnum;
2356 ehdr.e_phoff = sizeof(ElfW(Ehdr));
2357 }
2358
2359 /* align to 4 */
2360 file_offset = (file_offset + 3) & -4;
2361
2362 /* fill header */
2363 ehdr.e_ident[0] = ELFMAG0;
2364 ehdr.e_ident[1] = ELFMAG1;
2365 ehdr.e_ident[2] = ELFMAG2;
2366 ehdr.e_ident[3] = ELFMAG3;
2367 ehdr.e_ident[4] = ELFCLASSW;
2368 ehdr.e_ident[5] = ELFDATA2LSB;
2369 ehdr.e_ident[6] = EV_CURRENT;
2370 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2371 ehdr.e_ident[EI_OSABI] = ELFOSABI_FREEBSD;
2372 #endif
2373 #ifdef TCC_TARGET_ARM
2374 #ifdef TCC_ARM_EABI
2375 ehdr.e_ident[EI_OSABI] = 0;
2376 ehdr.e_flags = EF_ARM_EABI_VER4;
2377 if (file_type == TCC_OUTPUT_EXE || file_type == TCC_OUTPUT_DLL)
2378 ehdr.e_flags |= EF_ARM_HASENTRY;
2379 if (s1->float_abi == ARM_HARD_FLOAT)
2380 ehdr.e_flags |= EF_ARM_VFP_FLOAT;
2381 else
2382 ehdr.e_flags |= EF_ARM_SOFT_FLOAT;
2383 #else
2384 ehdr.e_ident[EI_OSABI] = ELFOSABI_ARM;
2385 #endif
2386 #endif
2387 switch(file_type) {
2388 default:
2389 case TCC_OUTPUT_EXE:
2390 ehdr.e_type = ET_EXEC;
2391 ehdr.e_entry = get_elf_sym_addr(s1, "_start", 1);
2392 break;
2393 case TCC_OUTPUT_DLL:
2394 ehdr.e_type = ET_DYN;
2395 ehdr.e_entry = text_section->sh_addr; /* XXX: is it correct ? */
2396 break;
2397 case TCC_OUTPUT_OBJ:
2398 ehdr.e_type = ET_REL;
2399 break;
2400 }
2401 ehdr.e_machine = EM_TCC_TARGET;
2402 ehdr.e_version = EV_CURRENT;
2403 ehdr.e_shoff = file_offset;
2404 ehdr.e_ehsize = sizeof(ElfW(Ehdr));
2405 ehdr.e_shentsize = sizeof(ElfW(Shdr));
2406 ehdr.e_shnum = shnum;
2407 ehdr.e_shstrndx = shnum - 1;
2408
2409 fwrite(&ehdr, 1, sizeof(ElfW(Ehdr)), f);
2410 fwrite(phdr, 1, phnum * sizeof(ElfW(Phdr)), f);
2411 offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr));
2412
2413 sort_syms(s1, symtab_section);
2414 for(i = 1; i < s1->nb_sections; i++) {
2415 s = s1->sections[sec_order[i]];
2416 if (s->sh_type != SHT_NOBITS) {
2417 if (s->sh_type == SHT_DYNSYM)
2418 patch_dynsym_undef(s1, s);
2419 while (offset < s->sh_offset) {
2420 fputc(0, f);
2421 offset++;
2422 }
2423 size = s->sh_size;
2424 if (size)
2425 fwrite(s->data, 1, size, f);
2426 offset += size;
2427 }
2428 }
2429
2430 /* output section headers */
2431 while (offset < ehdr.e_shoff) {
2432 fputc(0, f);
2433 offset++;
2434 }
2435
2436 for(i = 0; i < s1->nb_sections; i++) {
2437 sh = &shdr;
2438 memset(sh, 0, sizeof(ElfW(Shdr)));
2439 s = s1->sections[i];
2440 if (s) {
2441 sh->sh_name = s->sh_name;
2442 sh->sh_type = s->sh_type;
2443 sh->sh_flags = s->sh_flags;
2444 sh->sh_entsize = s->sh_entsize;
2445 sh->sh_info = s->sh_info;
2446 if (s->link)
2447 sh->sh_link = s->link->sh_num;
2448 sh->sh_addralign = s->sh_addralign;
2449 sh->sh_addr = s->sh_addr;
2450 sh->sh_offset = s->sh_offset;
2451 sh->sh_size = s->sh_size;
2452 }
2453 fwrite(sh, 1, sizeof(ElfW(Shdr)), f);
2454 }
2455 }
2456
2457 /* Write an elf, coff or "binary" file */
2458 static int tcc_write_elf_file(TCCState *s1, const char *filename, int phnum,
2459 ElfW(Phdr) *phdr, int file_offset, int *sec_order)
2460 {
2461 int fd, mode, file_type;
2462 FILE *f;
2463
2464 file_type = s1->output_type;
2465 if (file_type == TCC_OUTPUT_OBJ)
2466 mode = 0666;
2467 else
2468 mode = 0777;
2469 unlink(filename);
2470 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, mode);
2471 if (fd < 0) {
2472 tcc_error_noabort("could not write '%s'", filename);
2473 return -1;
2474 }
2475 f = fdopen(fd, "wb");
2476 if (s1->verbose)
2477 printf("<- %s\n", filename);
2478
2479 #ifdef TCC_TARGET_COFF
2480 if (s1->output_format == TCC_OUTPUT_FORMAT_COFF)
2481 tcc_output_coff(s1, f);
2482 else
2483 #endif
2484 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF)
2485 tcc_output_elf(s1, f, phnum, phdr, file_offset, sec_order);
2486 else
2487 tcc_output_binary(s1, f, sec_order);
2488 fclose(f);
2489
2490 return 0;
2491 }
2492
2493 /* Output an elf, coff or binary file */
2494 /* XXX: suppress unneeded sections */
2495 static int elf_output_file(TCCState *s1, const char *filename)
2496 {
2497 int i, ret, phnum, shnum, file_type, file_offset, *sec_order;
2498 struct dyn_inf dyninf;
2499 ElfW(Phdr) *phdr;
2500 ElfW(Sym) *sym;
2501 Section *strsec, *interp, *dynamic, *dynstr;
2502
2503 file_type = s1->output_type;
2504 s1->nb_errors = 0;
2505
2506 /* if linking, also link in runtime libraries (libc, libgcc, etc.) */
2507 if (file_type != TCC_OUTPUT_OBJ) {
2508 tcc_add_runtime(s1);
2509 }
2510
2511 phdr = NULL;
2512 sec_order = NULL;
2513 interp = dynamic = dynstr = NULL; /* avoid warning */
2514 dyninf.dyn_rel_off = 0; /* avoid warning */
2515
2516 if (file_type != TCC_OUTPUT_OBJ) {
2517 relocate_common_syms();
2518
2519 tcc_add_linker_symbols(s1);
2520
2521 if (!s1->static_link) {
2522 if (file_type == TCC_OUTPUT_EXE) {
2523 char *ptr;
2524 /* allow override the dynamic loader */
2525 const char *elfint = getenv("LD_SO");
2526 if (elfint == NULL)
2527 elfint = DEFAULT_ELFINTERP(s1);
2528 /* add interpreter section only if executable */
2529 interp = new_section(s1, ".interp", SHT_PROGBITS, SHF_ALLOC);
2530 interp->sh_addralign = 1;
2531 ptr = section_ptr_add(interp, 1 + strlen(elfint));
2532 strcpy(ptr, elfint);
2533 }
2534
2535 /* add dynamic symbol table */
2536 s1->dynsym = new_symtab(s1, ".dynsym", SHT_DYNSYM, SHF_ALLOC,
2537 ".dynstr",
2538 ".hash", SHF_ALLOC);
2539 dynstr = s1->dynsym->link;
2540
2541 /* add dynamic section */
2542 dynamic = new_section(s1, ".dynamic", SHT_DYNAMIC,
2543 SHF_ALLOC | SHF_WRITE);
2544 dynamic->link = dynstr;
2545 dynamic->sh_entsize = sizeof(ElfW(Dyn));
2546
2547 build_got(s1);
2548
2549 if (file_type == TCC_OUTPUT_EXE) {
2550 bind_exe_dynsyms(s1);
2551
2552 if (s1->nb_errors) {
2553 ret = -1;
2554 goto the_end;
2555 }
2556
2557 bind_libs_dynsyms(s1);
2558 } else /* shared library case: simply export all global symbols */
2559 export_global_syms(s1);
2560
2561 build_got_entries(s1);
2562
2563 /* add a list of needed dlls */
2564 for(i = 0; i < s1->nb_loaded_dlls; i++) {
2565 DLLReference *dllref = s1->loaded_dlls[i];
2566 if (dllref->level == 0)
2567 put_dt(dynamic, DT_NEEDED, put_elf_str(dynstr, dllref->name));
2568 }
2569
2570 if (s1->rpath)
2571 put_dt(dynamic, DT_RPATH, put_elf_str(dynstr, s1->rpath));
2572
2573 /* XXX: currently, since we do not handle PIC code, we
2574 must relocate the readonly segments */
2575 if (file_type == TCC_OUTPUT_DLL) {
2576 if (s1->soname)
2577 put_dt(dynamic, DT_SONAME, put_elf_str(dynstr, s1->soname));
2578 put_dt(dynamic, DT_TEXTREL, 0);
2579 }
2580
2581 if (s1->symbolic)
2582 put_dt(dynamic, DT_SYMBOLIC, 0);
2583
2584 /* add necessary space for other entries */
2585 dyninf.dyn_rel_off = dynamic->data_offset;
2586 dynamic->data_offset += sizeof(ElfW(Dyn)) * EXTRA_RELITEMS;
2587 } else {
2588 /* still need to build got entries in case of static link */
2589 build_got_entries(s1);
2590 }
2591 }
2592
2593 /* we add a section for symbols */
2594 strsec = new_section(s1, ".shstrtab", SHT_STRTAB, 0);
2595 put_elf_str(strsec, "");
2596
2597 /* compute number of sections */
2598 shnum = s1->nb_sections;
2599
2600 /* this array is used to reorder sections in the output file */
2601 sec_order = tcc_malloc(sizeof(int) * shnum);
2602 sec_order[0] = 0;
2603
2604 /* compute number of program headers */
2605 switch(file_type) {
2606 default:
2607 case TCC_OUTPUT_OBJ:
2608 phnum = 0;
2609 break;
2610 case TCC_OUTPUT_EXE:
2611 if (!s1->static_link)
2612 phnum = 4 + HAVE_PHDR;
2613 else
2614 phnum = 2;
2615 break;
2616 case TCC_OUTPUT_DLL:
2617 phnum = 3;
2618 break;
2619 }
2620
2621 /* Allocate strings for section names */
2622 alloc_sec_names(s1, file_type, strsec);
2623
2624 /* allocate program segment headers */
2625 phdr = tcc_mallocz(phnum * sizeof(ElfW(Phdr)));
2626
2627 /* compute section to program header mapping */
2628 file_offset = layout_sections(s1, phdr, phnum, interp, strsec, &dyninf,
2629 sec_order);
2630
2631 /* Fill remaining program header and finalize relocation related to dynamic
2632 linking. */
2633 if (phnum > 0) {
2634 fill_unloadable_phdr(phdr, phnum, interp, dynamic);
2635 if (dynamic) {
2636 dyninf.dynamic = dynamic;
2637 dyninf.dynstr = dynstr;
2638
2639 fill_dynamic(s1, &dyninf);
2640
2641 /* put in GOT the dynamic section address and relocate PLT */
2642 write32le(s1->got->data, dynamic->sh_addr);
2643 if (file_type == TCC_OUTPUT_EXE
2644 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
2645 || file_type == TCC_OUTPUT_DLL
2646 #endif
2647 )
2648 relocate_plt(s1);
2649
2650 /* relocate symbols in .dynsym now that final addresses are known */
2651 for_each_elem(s1->dynsym, 1, sym, ElfW(Sym)) {
2652 if (sym->st_shndx == SHN_UNDEF) {
2653 /* relocate to PLT if symbol corresponds to a PLT entry,
2654 but not if it's a weak symbol */
2655 if (ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
2656 sym->st_value = 0;
2657 else if (sym->st_value)
2658 sym->st_value += s1->plt->sh_addr;
2659 } else if (sym->st_shndx < SHN_LORESERVE) {
2660 /* do symbol relocation */
2661 sym->st_value += s1->sections[sym->st_shndx]->sh_addr;
2662 }
2663 }
2664 }
2665 }
2666
2667 /* if building executable or DLL, then relocate each section
2668 except the GOT which is already relocated */
2669 if (file_type != TCC_OUTPUT_OBJ) {
2670 ret = final_sections_reloc(s1);
2671 if (ret)
2672 goto the_end;
2673 }
2674
2675 /* Perform relocation to GOT or PLT entries */
2676 if (file_type == TCC_OUTPUT_EXE && s1->static_link)
2677 fill_got(s1);
2678
2679 /* Create the ELF file with name 'filename' */
2680 ret = tcc_write_elf_file(s1, filename, phnum, phdr, file_offset, sec_order);
2681 if (s1->do_strip) {
2682 int rc;
2683 const char *strip_cmd = "sstrip "; // super strip utility from ELFkickers
2684 const char *null_dev = " 2> /dev/null";
2685 char buf[1050];
2686 snprintf(buf, sizeof(buf), "%s%s%s", strip_cmd, filename, null_dev);
2687 rc = system(buf);
2688 if (rc)
2689 system(buf+1); // call a strip utility from binutils
2690 }
2691 the_end:
2692 tcc_free(s1->symtab_to_dynsym);
2693 tcc_free(sec_order);
2694 tcc_free(phdr);
2695 tcc_free(s1->sym_attrs);
2696 s1->sym_attrs = NULL;
2697 return ret;
2698 }
2699
2700 LIBTCCAPI int tcc_output_file(TCCState *s, const char *filename)
2701 {
2702 int ret;
2703 #ifdef TCC_TARGET_PE
2704 if (s->output_type != TCC_OUTPUT_OBJ) {
2705 ret = pe_output_file(s, filename);
2706 } else
2707 #endif
2708 ret = elf_output_file(s, filename);
2709 return ret;
2710 }
2711
2712 static void *load_data(int fd, unsigned long file_offset, unsigned long size)
2713 {
2714 void *data;
2715
2716 data = tcc_malloc(size);
2717 lseek(fd, file_offset, SEEK_SET);
2718 read(fd, data, size);
2719 return data;
2720 }
2721
2722 typedef struct SectionMergeInfo {
2723 Section *s; /* corresponding existing section */
2724 unsigned long offset; /* offset of the new section in the existing section */
2725 uint8_t new_section; /* true if section 's' was added */
2726 uint8_t link_once; /* true if link once section */
2727 } SectionMergeInfo;
2728
2729 /* load an object file and merge it with current files */
2730 /* XXX: handle correctly stab (debug) info */
2731 ST_FUNC int tcc_load_object_file(TCCState *s1,
2732 int fd, unsigned long file_offset)
2733 {
2734 ElfW(Ehdr) ehdr;
2735 ElfW(Shdr) *shdr, *sh;
2736 int size, i, j, offset, offseti, nb_syms, sym_index, ret;
2737 unsigned char *strsec, *strtab;
2738 int *old_to_new_syms;
2739 char *sh_name, *name;
2740 SectionMergeInfo *sm_table, *sm;
2741 ElfW(Sym) *sym, *symtab;
2742 ElfW_Rel *rel;
2743 Section *s;
2744
2745 int stab_index;
2746 int stabstr_index;
2747
2748 stab_index = stabstr_index = 0;
2749
2750 if (read(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr))
2751 goto fail1;
2752 if (ehdr.e_ident[0] != ELFMAG0 ||
2753 ehdr.e_ident[1] != ELFMAG1 ||
2754 ehdr.e_ident[2] != ELFMAG2 ||
2755 ehdr.e_ident[3] != ELFMAG3)
2756 goto fail1;
2757 /* test if object file */
2758 if (ehdr.e_type != ET_REL)
2759 goto fail1;
2760 /* test CPU specific stuff */
2761 if (ehdr.e_ident[5] != ELFDATA2LSB ||
2762 ehdr.e_machine != EM_TCC_TARGET) {
2763 fail1:
2764 tcc_error_noabort("invalid object file");
2765 return -1;
2766 }
2767 /* read sections */
2768 shdr = load_data(fd, file_offset + ehdr.e_shoff,
2769 sizeof(ElfW(Shdr)) * ehdr.e_shnum);
2770 sm_table = tcc_mallocz(sizeof(SectionMergeInfo) * ehdr.e_shnum);
2771
2772 /* load section names */
2773 sh = &shdr[ehdr.e_shstrndx];
2774 strsec = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2775
2776 /* load symtab and strtab */
2777 old_to_new_syms = NULL;
2778 symtab = NULL;
2779 strtab = NULL;
2780 nb_syms = 0;
2781 for(i = 1; i < ehdr.e_shnum; i++) {
2782 sh = &shdr[i];
2783 if (sh->sh_type == SHT_SYMTAB) {
2784 if (symtab) {
2785 tcc_error_noabort("object must contain only one symtab");
2786 fail:
2787 ret = -1;
2788 goto the_end;
2789 }
2790 nb_syms = sh->sh_size / sizeof(ElfW(Sym));
2791 symtab = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2792 sm_table[i].s = symtab_section;
2793
2794 /* now load strtab */
2795 sh = &shdr[sh->sh_link];
2796 strtab = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2797 }
2798 }
2799
2800 /* now examine each section and try to merge its content with the
2801 ones in memory */
2802 for(i = 1; i < ehdr.e_shnum; i++) {
2803 /* no need to examine section name strtab */
2804 if (i == ehdr.e_shstrndx)
2805 continue;
2806 sh = &shdr[i];
2807 sh_name = (char *) strsec + sh->sh_name;
2808 /* ignore sections types we do not handle */
2809 if (sh->sh_type != SHT_PROGBITS &&
2810 sh->sh_type != SHT_RELX &&
2811 #ifdef TCC_ARM_EABI
2812 sh->sh_type != SHT_ARM_EXIDX &&
2813 #endif
2814 sh->sh_type != SHT_NOBITS &&
2815 sh->sh_type != SHT_PREINIT_ARRAY &&
2816 sh->sh_type != SHT_INIT_ARRAY &&
2817 sh->sh_type != SHT_FINI_ARRAY &&
2818 strcmp(sh_name, ".stabstr")
2819 )
2820 continue;
2821 if (sh->sh_addralign < 1)
2822 sh->sh_addralign = 1;
2823 /* find corresponding section, if any */
2824 for(j = 1; j < s1->nb_sections;j++) {
2825 s = s1->sections[j];
2826 if (!strcmp(s->name, sh_name)) {
2827 if (!strncmp(sh_name, ".gnu.linkonce",
2828 sizeof(".gnu.linkonce") - 1)) {
2829 /* if a 'linkonce' section is already present, we
2830 do not add it again. It is a little tricky as
2831 symbols can still be defined in
2832 it. */
2833 sm_table[i].link_once = 1;
2834 goto next;
2835 } else {
2836 goto found;
2837 }
2838 }
2839 }
2840 /* not found: create new section */
2841 s = new_section(s1, sh_name, sh->sh_type, sh->sh_flags);
2842 /* take as much info as possible from the section. sh_link and
2843 sh_info will be updated later */
2844 s->sh_addralign = sh->sh_addralign;
2845 s->sh_entsize = sh->sh_entsize;
2846 sm_table[i].new_section = 1;
2847 found:
2848 if (sh->sh_type != s->sh_type) {
2849 tcc_error_noabort("invalid section type");
2850 goto fail;
2851 }
2852
2853 /* align start of section */
2854 offset = s->data_offset;
2855
2856 if (0 == strcmp(sh_name, ".stab")) {
2857 stab_index = i;
2858 goto no_align;
2859 }
2860 if (0 == strcmp(sh_name, ".stabstr")) {
2861 stabstr_index = i;
2862 goto no_align;
2863 }
2864
2865 size = sh->sh_addralign - 1;
2866 offset = (offset + size) & ~size;
2867 if (sh->sh_addralign > s->sh_addralign)
2868 s->sh_addralign = sh->sh_addralign;
2869 s->data_offset = offset;
2870 no_align:
2871 sm_table[i].offset = offset;
2872 sm_table[i].s = s;
2873 /* concatenate sections */
2874 size = sh->sh_size;
2875 if (sh->sh_type != SHT_NOBITS) {
2876 unsigned char *ptr;
2877 lseek(fd, file_offset + sh->sh_offset, SEEK_SET);
2878 ptr = section_ptr_add(s, size);
2879 read(fd, ptr, size);
2880 } else {
2881 s->data_offset += size;
2882 }
2883 next: ;
2884 }
2885
2886 /* gr relocate stab strings */
2887 if (stab_index && stabstr_index) {
2888 Stab_Sym *a, *b;
2889 unsigned o;
2890 s = sm_table[stab_index].s;
2891 a = (Stab_Sym *)(s->data + sm_table[stab_index].offset);
2892 b = (Stab_Sym *)(s->data + s->data_offset);
2893 o = sm_table[stabstr_index].offset;
2894 while (a < b)
2895 a->n_strx += o, a++;
2896 }
2897
2898 /* second short pass to update sh_link and sh_info fields of new
2899 sections */
2900 for(i = 1; i < ehdr.e_shnum; i++) {
2901 s = sm_table[i].s;
2902 if (!s || !sm_table[i].new_section)
2903 continue;
2904 sh = &shdr[i];
2905 if (sh->sh_link > 0)
2906 s->link = sm_table[sh->sh_link].s;
2907 if (sh->sh_type == SHT_RELX) {
2908 s->sh_info = sm_table[sh->sh_info].s->sh_num;
2909 /* update backward link */
2910 s1->sections[s->sh_info]->reloc = s;
2911 }
2912 }
2913 sm = sm_table;
2914
2915 /* resolve symbols */
2916 old_to_new_syms = tcc_mallocz(nb_syms * sizeof(int));
2917
2918 sym = symtab + 1;
2919 for(i = 1; i < nb_syms; i++, sym++) {
2920 if (sym->st_shndx != SHN_UNDEF &&
2921 sym->st_shndx < SHN_LORESERVE) {
2922 sm = &sm_table[sym->st_shndx];
2923 if (sm->link_once) {
2924 /* if a symbol is in a link once section, we use the
2925 already defined symbol. It is very important to get
2926 correct relocations */
2927 if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
2928 name = (char *) strtab + sym->st_name;
2929 sym_index = find_elf_sym(symtab_section, name);
2930 if (sym_index)
2931 old_to_new_syms[i] = sym_index;
2932 }
2933 continue;
2934 }
2935 /* if no corresponding section added, no need to add symbol */
2936 if (!sm->s)
2937 continue;
2938 /* convert section number */
2939 sym->st_shndx = sm->s->sh_num;
2940 /* offset value */
2941 sym->st_value += sm->offset;
2942 }
2943 /* add symbol */
2944 name = (char *) strtab + sym->st_name;
2945 sym_index = add_elf_sym(symtab_section, sym->st_value, sym->st_size,
2946 sym->st_info, sym->st_other,
2947 sym->st_shndx, name);
2948 old_to_new_syms[i] = sym_index;
2949 }
2950
2951 /* third pass to patch relocation entries */
2952 for(i = 1; i < ehdr.e_shnum; i++) {
2953 s = sm_table[i].s;
2954 if (!s)
2955 continue;
2956 sh = &shdr[i];
2957 offset = sm_table[i].offset;
2958 switch(s->sh_type) {
2959 case SHT_RELX:
2960 /* take relocation offset information */
2961 offseti = sm_table[sh->sh_info].offset;
2962 for_each_elem(s, (offset / sizeof(*rel)), rel, ElfW_Rel) {
2963 int type;
2964 unsigned sym_index;
2965 /* convert symbol index */
2966 type = ELFW(R_TYPE)(rel->r_info);
2967 sym_index = ELFW(R_SYM)(rel->r_info);
2968 /* NOTE: only one symtab assumed */
2969 if (sym_index >= nb_syms)
2970 goto invalid_reloc;
2971 sym_index = old_to_new_syms[sym_index];
2972 /* ignore link_once in rel section. */
2973 if (!sym_index && !sm->link_once
2974 #ifdef TCC_TARGET_ARM
2975 && type != R_ARM_V4BX
2976 #endif
2977 ) {
2978 invalid_reloc:
2979 tcc_error_noabort("Invalid relocation entry [%2d] '%s' @ %.8x",
2980 i, strsec + sh->sh_name, rel->r_offset);
2981 goto fail;
2982 }
2983 rel->r_info = ELFW(R_INFO)(sym_index, type);
2984 /* offset the relocation offset */
2985 rel->r_offset += offseti;
2986 #ifdef TCC_TARGET_ARM
2987 /* Jumps and branches from a Thumb code to a PLT entry need
2988 special handling since PLT entries are ARM code.
2989 Unconditional bl instructions referencing PLT entries are
2990 handled by converting these instructions into blx
2991 instructions. Other case of instructions referencing a PLT
2992 entry require to add a Thumb stub before the PLT entry to
2993 switch to ARM mode. We set bit plt_thumb_stub of the
2994 attribute of a symbol to indicate such a case. */
2995 if (type == R_ARM_THM_JUMP24)
2996 alloc_sym_attr(s1, sym_index)->plt_thumb_stub = 1;
2997 #endif
2998 }
2999 break;
3000 default:
3001 break;
3002 }
3003 }
3004
3005 ret = 0;
3006 the_end:
3007 tcc_free(symtab);
3008 tcc_free(strtab);
3009 tcc_free(old_to_new_syms);
3010 tcc_free(sm_table);
3011 tcc_free(strsec);
3012 tcc_free(shdr);
3013 return ret;
3014 }
3015
3016 typedef struct ArchiveHeader {
3017 char ar_name[16]; /* name of this member */
3018 char ar_date[12]; /* file mtime */
3019 char ar_uid[6]; /* owner uid; printed as decimal */
3020 char ar_gid[6]; /* owner gid; printed as decimal */
3021 char ar_mode[8]; /* file mode, printed as octal */
3022 char ar_size[10]; /* file size, printed as decimal */
3023 char ar_fmag[2]; /* should contain ARFMAG */
3024 } ArchiveHeader;
3025
3026 static int get_be32(const uint8_t *b)
3027 {
3028 return b[3] | (b[2] << 8) | (b[1] << 16) | (b[0] << 24);
3029 }
3030
3031 /* load only the objects which resolve undefined symbols */
3032 static int tcc_load_alacarte(TCCState *s1, int fd, int size)
3033 {
3034 int i, bound, nsyms, sym_index, off, ret;
3035 uint8_t *data;
3036 const char *ar_names, *p;
3037 const uint8_t *ar_index;
3038 ElfW(Sym) *sym;
3039
3040 data = tcc_malloc(size);
3041 if (read(fd, data, size) != size)
3042 goto fail;
3043 nsyms = get_be32(data);
3044 ar_index = data + 4;
3045 ar_names = (char *) ar_index + nsyms * 4;
3046
3047 do {
3048 bound = 0;
3049 for(p = ar_names, i = 0; i < nsyms; i++, p += strlen(p)+1) {
3050 sym_index = find_elf_sym(symtab_section, p);
3051 if(sym_index) {
3052 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
3053 if(sym->st_shndx == SHN_UNDEF) {
3054 off = get_be32(ar_index + i * 4) + sizeof(ArchiveHeader);
3055 ++bound;
3056 lseek(fd, off, SEEK_SET);
3057 if(tcc_load_object_file(s1, fd, off) < 0) {
3058 fail:
3059 ret = -1;
3060 goto the_end;
3061 }
3062 }
3063 }
3064 }
3065 } while(bound);
3066 ret = 0;
3067 the_end:
3068 tcc_free(data);
3069 return ret;
3070 }
3071
3072 /* load a '.a' file */
3073 ST_FUNC int tcc_load_archive(TCCState *s1, int fd)
3074 {
3075 ArchiveHeader hdr;
3076 char ar_size[11];
3077 char ar_name[17];
3078 char magic[8];
3079 int size, len, i;
3080 unsigned long file_offset;
3081
3082 /* skip magic which was already checked */
3083 read(fd, magic, sizeof(magic));
3084
3085 for(;;) {
3086 len = read(fd, &hdr, sizeof(hdr));
3087 if (len == 0)
3088 break;
3089 if (len != sizeof(hdr)) {
3090 tcc_error_noabort("invalid archive");
3091 return -1;
3092 }
3093 memcpy(ar_size, hdr.ar_size, sizeof(hdr.ar_size));
3094 ar_size[sizeof(hdr.ar_size)] = '\0';
3095 size = strtol(ar_size, NULL, 0);
3096 memcpy(ar_name, hdr.ar_name, sizeof(hdr.ar_name));
3097 for(i = sizeof(hdr.ar_name) - 1; i >= 0; i--) {
3098 if (ar_name[i] != ' ')
3099 break;
3100 }
3101 ar_name[i + 1] = '\0';
3102 file_offset = lseek(fd, 0, SEEK_CUR);
3103 /* align to even */
3104 size = (size + 1) & ~1;
3105 if (!strcmp(ar_name, "/")) {
3106 /* coff symbol table : we handle it */
3107 if(s1->alacarte_link)
3108 return tcc_load_alacarte(s1, fd, size);
3109 } else if (!strcmp(ar_name, "//") ||
3110 !strcmp(ar_name, "__.SYMDEF") ||
3111 !strcmp(ar_name, "__.SYMDEF/") ||
3112 !strcmp(ar_name, "ARFILENAMES/")) {
3113 /* skip symbol table or archive names */
3114 } else {
3115 if (tcc_load_object_file(s1, fd, file_offset) < 0)
3116 return -1;
3117 }
3118 lseek(fd, file_offset + size, SEEK_SET);
3119 }
3120 return 0;
3121 }
3122
3123 #ifndef TCC_TARGET_PE
3124 /* load a DLL and all referenced DLLs. 'level = 0' means that the DLL
3125 is referenced by the user (so it should be added as DT_NEEDED in
3126 the generated ELF file) */
3127 ST_FUNC int tcc_load_dll(TCCState *s1, int fd, const char *filename, int level)
3128 {
3129 ElfW(Ehdr) ehdr;
3130 ElfW(Shdr) *shdr, *sh, *sh1;
3131 int i, j, nb_syms, nb_dts, sym_bind, ret;
3132 ElfW(Sym) *sym, *dynsym;
3133 ElfW(Dyn) *dt, *dynamic;
3134 unsigned char *dynstr;
3135 const char *name, *soname;
3136 DLLReference *dllref;
3137
3138 read(fd, &ehdr, sizeof(ehdr));
3139
3140 /* test CPU specific stuff */
3141 if (ehdr.e_ident[5] != ELFDATA2LSB ||
3142 ehdr.e_machine != EM_TCC_TARGET) {
3143 tcc_error_noabort("bad architecture");
3144 return -1;
3145 }
3146
3147 /* read sections */
3148 shdr = load_data(fd, ehdr.e_shoff, sizeof(ElfW(Shdr)) * ehdr.e_shnum);
3149
3150 /* load dynamic section and dynamic symbols */
3151 nb_syms = 0;
3152 nb_dts = 0;
3153 dynamic = NULL;
3154 dynsym = NULL; /* avoid warning */
3155 dynstr = NULL; /* avoid warning */
3156 for(i = 0, sh = shdr; i < ehdr.e_shnum; i++, sh++) {
3157 switch(sh->sh_type) {
3158 case SHT_DYNAMIC:
3159 nb_dts = sh->sh_size / sizeof(ElfW(Dyn));
3160 dynamic = load_data(fd, sh->sh_offset, sh->sh_size);
3161 break;
3162 case SHT_DYNSYM:
3163 nb_syms = sh->sh_size / sizeof(ElfW(Sym));
3164 dynsym = load_data(fd, sh->sh_offset, sh->sh_size);
3165 sh1 = &shdr[sh->sh_link];
3166 dynstr = load_data(fd, sh1->sh_offset, sh1->sh_size);
3167 break;
3168 default:
3169 break;
3170 }
3171 }
3172
3173 /* compute the real library name */
3174 soname = tcc_basename(filename);
3175
3176 for(i = 0, dt = dynamic; i < nb_dts; i++, dt++) {
3177 if (dt->d_tag == DT_SONAME) {
3178 soname = (char *) dynstr + dt->d_un.d_val;
3179 }
3180 }
3181
3182 /* if the dll is already loaded, do not load it */
3183 for(i = 0; i < s1->nb_loaded_dlls; i++) {
3184 dllref = s1->loaded_dlls[i];
3185 if (!strcmp(soname, dllref->name)) {
3186 /* but update level if needed */
3187 if (level < dllref->level)
3188 dllref->level = level;
3189 ret = 0;
3190 goto the_end;
3191 }
3192 }
3193
3194 /* add the dll and its level */
3195 dllref = tcc_mallocz(sizeof(DLLReference) + strlen(soname));
3196 dllref->level = level;
3197 strcpy(dllref->name, soname);
3198 dynarray_add((void ***)&s1->loaded_dlls, &s1->nb_loaded_dlls, dllref);
3199
3200 /* add dynamic symbols in dynsym_section */
3201 for(i = 1, sym = dynsym + 1; i < nb_syms; i++, sym++) {
3202 sym_bind = ELFW(ST_BIND)(sym->st_info);
3203 if (sym_bind == STB_LOCAL)
3204 continue;
3205 name = (char *) dynstr + sym->st_name;
3206 add_elf_sym(s1->dynsymtab_section, sym->st_value, sym->st_size,
3207 sym->st_info, sym->st_other, sym->st_shndx, name);
3208 }
3209
3210 /* load all referenced DLLs */
3211 for(i = 0, dt = dynamic; i < nb_dts; i++, dt++) {
3212 switch(dt->d_tag) {
3213 case DT_NEEDED:
3214 name = (char *) dynstr + dt->d_un.d_val;
3215 for(j = 0; j < s1->nb_loaded_dlls; j++) {
3216 dllref = s1->loaded_dlls[j];
3217 if (!strcmp(name, dllref->name))
3218 goto already_loaded;
3219 }
3220 if (tcc_add_dll(s1, name, AFF_REFERENCED_DLL) < 0) {
3221 tcc_error_noabort("referenced dll '%s' not found", name);
3222 ret = -1;
3223 goto the_end;
3224 }
3225 already_loaded:
3226 break;
3227 }
3228 }
3229 ret = 0;
3230 the_end:
3231 tcc_free(dynstr);
3232 tcc_free(dynsym);
3233 tcc_free(dynamic);
3234 tcc_free(shdr);
3235 return ret;
3236 }
3237
3238 #define LD_TOK_NAME 256
3239 #define LD_TOK_EOF (-1)
3240
3241 /* return next ld script token */
3242 static int ld_next(TCCState *s1, char *name, int name_size)
3243 {
3244 int c;
3245 char *q;
3246
3247 redo:
3248 switch(ch) {
3249 case ' ':
3250 case '\t':
3251 case '\f':
3252 case '\v':
3253 case '\r':
3254 case '\n':
3255 inp();
3256 goto redo;
3257 case '/':
3258 minp();
3259 if (ch == '*') {
3260 file->buf_ptr = parse_comment(file->buf_ptr);
3261 ch = file->buf_ptr[0];
3262 goto redo;
3263 } else {
3264 q = name;
3265 *q++ = '/';
3266 goto parse_name;
3267 }
3268 break;
3269 case '\\':
3270 ch = handle_eob();
3271 if (ch != '\\')
3272 goto redo;
3273 /* fall through */
3274 /* case 'a' ... 'z': */
3275 case 'a':
3276 case 'b':
3277 case 'c':
3278 case 'd':
3279 case 'e':
3280 case 'f':
3281 case 'g':
3282 case 'h':
3283 case 'i':
3284 case 'j':
3285 case 'k':
3286 case 'l':
3287 case 'm':
3288 case 'n':
3289 case 'o':
3290 case 'p':
3291 case 'q':
3292 case 'r':
3293 case 's':
3294 case 't':
3295 case 'u':
3296 case 'v':
3297 case 'w':
3298 case 'x':
3299 case 'y':
3300 case 'z':
3301 /* case 'A' ... 'z': */
3302 case 'A':
3303 case 'B':
3304 case 'C':
3305 case 'D':
3306 case 'E':
3307 case 'F':
3308 case 'G':
3309 case 'H':
3310 case 'I':
3311 case 'J':
3312 case 'K':
3313 case 'L':
3314 case 'M':
3315 case 'N':
3316 case 'O':
3317 case 'P':
3318 case 'Q':
3319 case 'R':
3320 case 'S':
3321 case 'T':
3322 case 'U':
3323 case 'V':
3324 case 'W':
3325 case 'X':
3326 case 'Y':
3327 case 'Z':
3328 case '_':
3329 case '.':
3330 case '$':
3331 case '~':
3332 q = name;
3333 parse_name:
3334 for(;;) {
3335 if (!((ch >= 'a' && ch <= 'z') ||
3336 (ch >= 'A' && ch <= 'Z') ||
3337 (ch >= '0' && ch <= '9') ||
3338 strchr("/.-_+=$:\\,~", ch)))
3339 break;
3340 if ((q - name) < name_size - 1) {
3341 *q++ = ch;
3342 }
3343 minp();
3344 }
3345 *q = '\0';
3346 c = LD_TOK_NAME;
3347 break;
3348 case CH_EOF:
3349 c = LD_TOK_EOF;
3350 break;
3351 default:
3352 c = ch;
3353 inp();
3354 break;
3355 }
3356 return c;
3357 }
3358
3359 static int ld_add_file(TCCState *s1, const char filename[])
3360 {
3361 int ret;
3362
3363 ret = tcc_add_file_internal(s1, filename, 0, TCC_FILETYPE_BINARY);
3364 if (ret)
3365 ret = tcc_add_dll(s1, filename, 0);
3366 return ret;
3367 }
3368
3369 static inline int new_undef_syms(void)
3370 {
3371 int ret = 0;
3372 ret = new_undef_sym;
3373 new_undef_sym = 0;
3374 return ret;
3375 }
3376
3377 static int ld_add_file_list(TCCState *s1, const char *cmd, int as_needed)
3378 {
3379 char filename[1024], libname[1024];
3380 int t, group, nblibs = 0, ret = 0;
3381 char **libs = NULL;
3382
3383 group = !strcmp(cmd, "GROUP");
3384 if (!as_needed)
3385 new_undef_syms();
3386 t = ld_next(s1, filename, sizeof(filename));
3387 if (t != '(')
3388 expect("(");
3389 t = ld_next(s1, filename, sizeof(filename));
3390 for(;;) {
3391 libname[0] = '\0';
3392 if (t == LD_TOK_EOF) {
3393 tcc_error_noabort("unexpected end of file");
3394 ret = -1;
3395 goto lib_parse_error;
3396 } else if (t == ')') {
3397 break;
3398 } else if (t == '-') {
3399 t = ld_next(s1, filename, sizeof(filename));
3400 if ((t != LD_TOK_NAME) || (filename[0] != 'l')) {
3401 tcc_error_noabort("library name expected");
3402 ret = -1;
3403 goto lib_parse_error;
3404 }
3405 pstrcpy(libname, sizeof libname, &filename[1]);
3406 if (s1->static_link) {
3407 snprintf(filename, sizeof filename, "lib%s.a", libname);
3408 } else {
3409 snprintf(filename, sizeof filename, "lib%s.so", libname);
3410 }
3411 } else if (t != LD_TOK_NAME) {
3412 tcc_error_noabort("filename expected");
3413 ret = -1;
3414 goto lib_parse_error;
3415 }
3416 if (!strcmp(filename, "AS_NEEDED")) {
3417 ret = ld_add_file_list(s1, cmd, 1);
3418 if (ret)
3419 goto lib_parse_error;
3420 } else {
3421 /* TODO: Implement AS_NEEDED support. Ignore it for now */
3422 if (!as_needed) {
3423 ret = ld_add_file(s1, filename);
3424 if (ret)
3425 goto lib_parse_error;
3426 if (group) {
3427 /* Add the filename *and* the libname to avoid future conversions */
3428 dynarray_add((void ***) &libs, &nblibs, tcc_strdup(filename));
3429 if (libname[0] != '\0')
3430 dynarray_add((void ***) &libs, &nblibs, tcc_strdup(libname));
3431 }
3432 }
3433 }
3434 t = ld_next(s1, filename, sizeof(filename));
3435 if (t == ',') {
3436 t = ld_next(s1, filename, sizeof(filename));
3437 }
3438 }
3439 if (group && !as_needed) {
3440 while (new_undef_syms()) {
3441 int i;
3442
3443 for (i = 0; i < nblibs; i ++)
3444 ld_add_file(s1, libs[i]);
3445 }
3446 }
3447 lib_parse_error:
3448 dynarray_reset(&libs, &nblibs);
3449 return ret;
3450 }
3451
3452 /* interpret a subset of GNU ldscripts to handle the dummy libc.so
3453 files */
3454 ST_FUNC int tcc_load_ldscript(TCCState *s1)
3455 {
3456 char cmd[64];
3457 char filename[1024];
3458 int t, ret;
3459
3460 ch = handle_eob();
3461 for(;;) {
3462 t = ld_next(s1, cmd, sizeof(cmd));
3463 if (t == LD_TOK_EOF)
3464 return 0;
3465 else if (t != LD_TOK_NAME)
3466 return -1;
3467 if (!strcmp(cmd, "INPUT") ||
3468 !strcmp(cmd, "GROUP")) {
3469 ret = ld_add_file_list(s1, cmd, 0);
3470 if (ret)
3471 return ret;
3472 } else if (!strcmp(cmd, "OUTPUT_FORMAT") ||
3473 !strcmp(cmd, "TARGET")) {
3474 /* ignore some commands */
3475 t = ld_next(s1, cmd, sizeof(cmd));
3476 if (t != '(')
3477 expect("(");
3478 for(;;) {
3479 t = ld_next(s1, filename, sizeof(filename));
3480 if (t == LD_TOK_EOF) {
3481 tcc_error_noabort("unexpected end of file");
3482 return -1;
3483 } else if (t == ')') {
3484 break;
3485 }
3486 }
3487 } else {
3488 return -1;
3489 }
3490 }
3491 return 0;
3492 }
3493 #endif /* !TCC_TARGET_PE */
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