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Revert "output all sections if we produce an executable file"
[tinycc.git] / tccelf.c
blob33336c6f7f094ae05cfb8d38033a0c7e7d4299cc
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 case R_386_GOT32X:
561 /* we load the got offset */
562 write32le(ptr, read32le(ptr) + s1->sym_attrs[sym_index].got_offset);
563 break;
564 case R_386_16:
565 if (s1->output_format != TCC_OUTPUT_FORMAT_BINARY) {
566 output_file:
567 tcc_error("can only produce 16-bit binary files");
568 }
569 write16le(ptr, read16le(ptr) + val);
570 break;
571 case R_386_PC16:
572 if (s1->output_format != TCC_OUTPUT_FORMAT_BINARY)
573 goto output_file;
574 write16le(ptr, read16le(ptr) + val - addr);
575 break;
576 case R_386_RELATIVE:
577 /* do nothing */
578 break;
579 case R_386_COPY:
580 /* This reloction must copy initialized data from the library
581 to the program .bss segment. Currently made like for ARM
582 (to remove noise of defaukt case). Is this true?
583 */
584 break;
585 default:
586 fprintf(stderr,"FIXME: handle reloc type %d at %x [%p] to %x\n",
587 type, (unsigned)addr, ptr, (unsigned)val);
588 break;
589 #elif defined(TCC_TARGET_ARM)
590 case R_ARM_PC24:
591 case R_ARM_CALL:
592 case R_ARM_JUMP24:
593 case R_ARM_PLT32:
594 {
595 int x, is_thumb, is_call, h, blx_avail, is_bl, th_ko;
596 x = (*(int *) ptr) & 0xffffff;
597 if (sym->st_shndx == SHN_UNDEF)
598 val = s1->plt->sh_addr;
599 #ifdef DEBUG_RELOC
600 printf ("reloc %d: x=0x%x val=0x%x ", type, x, val);
601 #endif
602 (*(int *)ptr) &= 0xff000000;
603 if (x & 0x800000)
604 x -= 0x1000000;
605 x <<= 2;
606 blx_avail = (TCC_ARM_VERSION >= 5);
607 is_thumb = val & 1;
608 is_bl = (*(unsigned *) ptr) >> 24 == 0xeb;
609 is_call = (type == R_ARM_CALL || (type == R_ARM_PC24 && is_bl));
610 x += val - addr;
611 #ifdef DEBUG_RELOC
612 printf (" newx=0x%x name=%s\n", x,
613 (char *) symtab_section->link->data + sym->st_name);
614 #endif
615 h = x & 2;
616 th_ko = (x & 3) && (!blx_avail || !is_call);
617 if (th_ko || x >= 0x2000000 || x < -0x2000000)
618 tcc_error("can't relocate value at %x,%d",addr, type);
619 x >>= 2;
620 x &= 0xffffff;
621 /* Only reached if blx is avail and it is a call */
622 if (is_thumb) {
623 x |= h << 24;
624 (*(int *)ptr) = 0xfa << 24; /* bl -> blx */
625 }
626 (*(int *) ptr) |= x;
627 }
628 break;
629 /* Since these relocations only concern Thumb-2 and blx instruction was
630 introduced before Thumb-2, we can assume blx is available and not
631 guard its use */
632 case R_ARM_THM_PC22:
633 case R_ARM_THM_JUMP24:
634 {
635 int x, hi, lo, s, j1, j2, i1, i2, imm10, imm11;
636 int to_thumb, is_call, to_plt, blx_bit = 1 << 12;
637 Section *plt;
638
639 /* weak reference */
640 if (sym->st_shndx == SHN_UNDEF &&
641 ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
642 break;
643
644 /* Get initial offset */
645 hi = (*(uint16_t *)ptr);
646 lo = (*(uint16_t *)(ptr+2));
647 s = (hi >> 10) & 1;
648 j1 = (lo >> 13) & 1;
649 j2 = (lo >> 11) & 1;
650 i1 = (j1 ^ s) ^ 1;
651 i2 = (j2 ^ s) ^ 1;
652 imm10 = hi & 0x3ff;
653 imm11 = lo & 0x7ff;
654 x = (s << 24) | (i1 << 23) | (i2 << 22) |
655 (imm10 << 12) | (imm11 << 1);
656 if (x & 0x01000000)
657 x -= 0x02000000;
658
659 /* Relocation infos */
660 to_thumb = val & 1;
661 plt = s1->plt;
662 to_plt = (val >= plt->sh_addr) &&
663 (val < plt->sh_addr + plt->data_offset);
664 is_call = (type == R_ARM_THM_PC22);
665
666 /* Compute final offset */
667 if (to_plt && !is_call) /* Point to 1st instr of Thumb stub */
668 x -= 4;
669 x += val - addr;
670 if (!to_thumb && is_call) {
671 blx_bit = 0; /* bl -> blx */
672 x = (x + 3) & -4; /* Compute offset from aligned PC */
673 }
674
675 /* Check that relocation is possible
676 * offset must not be out of range
677 * if target is to be entered in arm mode:
678 - bit 1 must not set
679 - instruction must be a call (bl) or a jump to PLT */
680 if (!to_thumb || x >= 0x1000000 || x < -0x1000000)
681 if (to_thumb || (val & 2) || (!is_call && !to_plt))
682 tcc_error("can't relocate value at %x,%d",addr, type);
683
684 /* Compute and store final offset */
685 s = (x >> 24) & 1;
686 i1 = (x >> 23) & 1;
687 i2 = (x >> 22) & 1;
688 j1 = s ^ (i1 ^ 1);
689 j2 = s ^ (i2 ^ 1);
690 imm10 = (x >> 12) & 0x3ff;
691 imm11 = (x >> 1) & 0x7ff;
692 (*(uint16_t *)ptr) = (uint16_t) ((hi & 0xf800) |
693 (s << 10) | imm10);
694 (*(uint16_t *)(ptr+2)) = (uint16_t) ((lo & 0xc000) |
695 (j1 << 13) | blx_bit | (j2 << 11) |
696 imm11);
697 }
698 break;
699 case R_ARM_MOVT_ABS:
700 case R_ARM_MOVW_ABS_NC:
701 {
702 int x, imm4, imm12;
703 if (type == R_ARM_MOVT_ABS)
704 val >>= 16;
705 imm12 = val & 0xfff;
706 imm4 = (val >> 12) & 0xf;
707 x = (imm4 << 16) | imm12;
708 if (type == R_ARM_THM_MOVT_ABS)
709 *(int *)ptr |= x;
710 else
711 *(int *)ptr += x;
712 }
713 break;
714 case R_ARM_THM_MOVT_ABS:
715 case R_ARM_THM_MOVW_ABS_NC:
716 {
717 int x, i, imm4, imm3, imm8;
718 if (type == R_ARM_THM_MOVT_ABS)
719 val >>= 16;
720 imm8 = val & 0xff;
721 imm3 = (val >> 8) & 0x7;
722 i = (val >> 11) & 1;
723 imm4 = (val >> 12) & 0xf;
724 x = (imm3 << 28) | (imm8 << 16) | (i << 10) | imm4;
725 if (type == R_ARM_THM_MOVT_ABS)
726 *(int *)ptr |= x;
727 else
728 *(int *)ptr += x;
729 }
730 break;
731 case R_ARM_PREL31:
732 {
733 int x;
734 x = (*(int *)ptr) & 0x7fffffff;
735 (*(int *)ptr) &= 0x80000000;
736 x = (x * 2) / 2;
737 x += val - addr;
738 if((x^(x>>1))&0x40000000)
739 tcc_error("can't relocate value at %x,%d",addr, type);
740 (*(int *)ptr) |= x & 0x7fffffff;
741 }
742 case R_ARM_ABS32:
743 *(int *)ptr += val;
744 break;
745 case R_ARM_REL32:
746 *(int *)ptr += val - addr;
747 break;
748 case R_ARM_GOTPC:
749 *(int *)ptr += s1->got->sh_addr - addr;
750 break;
751 case R_ARM_GOTOFF:
752 *(int *)ptr += val - s1->got->sh_addr;
753 break;
754 case R_ARM_GOT32:
755 /* we load the got offset */
756 *(int *)ptr += s1->sym_attrs[sym_index].got_offset;
757 break;
758 case R_ARM_COPY:
759 break;
760 case R_ARM_V4BX:
761 /* trade Thumb support for ARMv4 support */
762 if ((0x0ffffff0 & *(int*)ptr) == 0x012FFF10)
763 *(int*)ptr ^= 0xE12FFF10 ^ 0xE1A0F000; /* BX Rm -> MOV PC, Rm */
764 break;
765 case R_ARM_GLOB_DAT:
766 case R_ARM_JUMP_SLOT:
767 *(addr_t *)ptr = val;
768 break;
769 case R_ARM_NONE:
770 /* Nothing to do. Normally used to indicate a dependency
771 on a certain symbol (like for exception handling under EABI). */
772 break;
773 default:
774 fprintf(stderr,"FIXME: handle reloc type %x at %x [%p] to %x\n",
775 type, (unsigned)addr, ptr, (unsigned)val);
776 break;
777 #elif defined(TCC_TARGET_ARM64)
778 case R_AARCH64_ABS64:
779 write64le(ptr, val);
780 break;
781 case R_AARCH64_ABS32:
782 write32le(ptr, val);
783 break;
784 case R_AARCH64_MOVW_UABS_G0_NC:
785 write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
786 (val & 0xffff) << 5));
787 break;
788 case R_AARCH64_MOVW_UABS_G1_NC:
789 write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
790 (val >> 16 & 0xffff) << 5));
791 break;
792 case R_AARCH64_MOVW_UABS_G2_NC:
793 write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
794 (val >> 32 & 0xffff) << 5));
795 break;
796 case R_AARCH64_MOVW_UABS_G3:
797 write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
798 (val >> 48 & 0xffff) << 5));
799 break;
800 case R_AARCH64_ADR_PREL_PG_HI21: {
801 uint64_t off = (val >> 12) - (addr >> 12);
802 if ((off + ((uint64_t)1 << 20)) >> 21)
803 tcc_error("R_AARCH64_ADR_PREL_PG_HI21 relocation failed");
804 write32le(ptr, ((read32le(ptr) & 0x9f00001f) |
805 (off & 0x1ffffc) << 3 | (off & 3) << 29));
806 break;
807 }
808 case R_AARCH64_ADD_ABS_LO12_NC:
809 write32le(ptr, ((read32le(ptr) & 0xffc003ff) |
810 (val & 0xfff) << 10));
811 break;
812 case R_AARCH64_JUMP26:
813 case R_AARCH64_CALL26:
814 /* This check must match the one in build_got_entries, testing
815 if we really need a PLT slot. */
816 if (sym->st_shndx == SHN_UNDEF)
817 /* We've put the PLT slot offset into r_addend when generating
818 it, and that's what we must use as relocation value (adjusted
819 by section offset of course). */
820 val = s1->plt->sh_addr + rel->r_addend;
821 #ifdef DEBUG_RELOC
822 printf ("reloc %d @ 0x%lx: val=0x%lx name=%s\n", type, addr, val,
823 (char *) symtab_section->link->data + sym->st_name);
824 #endif
825 if (((val - addr) + ((uint64_t)1 << 27)) & ~(uint64_t)0xffffffc)
826 {
827 tcc_error("R_AARCH64_(JUMP|CALL)26 relocation failed (val=%lx, addr=%lx)", addr, val);
828 }
829 write32le(ptr, (0x14000000 |
830 (uint32_t)(type == R_AARCH64_CALL26) << 31 |
831 ((val - addr) >> 2 & 0x3ffffff)));
832 break;
833 case R_AARCH64_ADR_GOT_PAGE: {
834 uint64_t off =
835 (((s1->got->sh_addr +
836 s1->sym_attrs[sym_index].got_offset) >> 12) - (addr >> 12));
837 if ((off + ((uint64_t)1 << 20)) >> 21)
838 tcc_error("R_AARCH64_ADR_GOT_PAGE relocation failed");
839 write32le(ptr, ((read32le(ptr) & 0x9f00001f) |
840 (off & 0x1ffffc) << 3 | (off & 3) << 29));
841 break;
842 }
843 case R_AARCH64_LD64_GOT_LO12_NC:
844 write32le(ptr,
845 ((read32le(ptr) & 0xfff803ff) |
846 ((s1->got->sh_addr +
847 s1->sym_attrs[sym_index].got_offset) & 0xff8) << 7));
848 break;
849 case R_AARCH64_COPY:
850 break;
851 case R_AARCH64_GLOB_DAT:
852 case R_AARCH64_JUMP_SLOT:
853 /* They don't need addend */
854 #ifdef DEBUG_RELOC
855 printf ("reloc %d @ 0x%lx: val=0x%lx name=%s\n", type, addr,
856 val - rel->r_addend,
857 (char *) symtab_section->link->data + sym->st_name);
858 #endif
859 write64le(ptr, val - rel->r_addend);
860 break;
861 default:
862 fprintf(stderr, "FIXME: handle reloc type %x at %x [%p] to %x\n",
863 type, (unsigned)addr, ptr, (unsigned)val);
864 break;
865 #elif defined(TCC_TARGET_C67)
866 case R_C60_32:
867 *(int *)ptr += val;
868 break;
869 case R_C60LO16:
870 {
871 uint32_t orig;
872
873 /* put the low 16 bits of the absolute address
874 add to what is already there */
875
876 orig = ((*(int *)(ptr )) >> 7) & 0xffff;
877 orig |= (((*(int *)(ptr+4)) >> 7) & 0xffff) << 16;
878
879 /* patch both at once - assumes always in pairs Low - High */
880
881 *(int *) ptr = (*(int *) ptr & (~(0xffff << 7)) ) | (((val+orig) & 0xffff) << 7);
882 *(int *)(ptr+4) = (*(int *)(ptr+4) & (~(0xffff << 7)) ) | ((((val+orig)>>16) & 0xffff) << 7);
883 }
884 break;
885 case R_C60HI16:
886 break;
887 default:
888 fprintf(stderr,"FIXME: handle reloc type %x at %x [%p] to %x\n",
889 type, (unsigned)addr, ptr, (unsigned)val);
890 break;
891 #elif defined(TCC_TARGET_X86_64)
892 case R_X86_64_64:
893 if (s1->output_type == TCC_OUTPUT_DLL) {
894 esym_index = s1->symtab_to_dynsym[sym_index];
895 qrel->r_offset = rel->r_offset;
896 if (esym_index) {
897 qrel->r_info = ELFW(R_INFO)(esym_index, R_X86_64_64);
898 qrel->r_addend = rel->r_addend;
899 qrel++;
900 break;
901 } else {
902 qrel->r_info = ELFW(R_INFO)(0, R_X86_64_RELATIVE);
903 qrel->r_addend = read64le(ptr) + val;
904 qrel++;
905 }
906 }
907 write64le(ptr, read64le(ptr) + val);
908 break;
909 case R_X86_64_32:
910 case R_X86_64_32S:
911 if (s1->output_type == TCC_OUTPUT_DLL) {
912 /* XXX: this logic may depend on TCC's codegen
913 now TCC uses R_X86_64_32 even for a 64bit pointer */
914 qrel->r_info = ELFW(R_INFO)(0, R_X86_64_RELATIVE);
915 /* Use sign extension! */
916 qrel->r_addend = (int)read32le(ptr) + val;
917 qrel++;
918 }
919 write32le(ptr, read32le(ptr) + val);
920 break;
921
922 case R_X86_64_PC32:
923 if (s1->output_type == TCC_OUTPUT_DLL) {
924 /* DLL relocation */
925 esym_index = s1->symtab_to_dynsym[sym_index];
926 if (esym_index) {
927 qrel->r_offset = rel->r_offset;
928 qrel->r_info = ELFW(R_INFO)(esym_index, R_X86_64_PC32);
929 /* Use sign extension! */
930 qrel->r_addend = (int)read32le(ptr) + rel->r_addend;
931 qrel++;
932 break;
933 }
934 }
935 goto plt32pc32;
936
937 case R_X86_64_PLT32:
938 /* We've put the PLT slot offset into r_addend when generating
939 it, and that's what we must use as relocation value (adjusted
940 by section offset of course). */
941 val = s1->plt->sh_addr + rel->r_addend;
942 /* fallthrough. */
943
944 plt32pc32:
945 {
946 long long diff;
947 diff = (long long)val - addr;
948 if (diff < -2147483648LL || diff > 2147483647LL) {
949 tcc_error("internal error: relocation failed");
950 }
951 write32le(ptr, read32le(ptr) + diff);
952 }
953 break;
954 case R_X86_64_GLOB_DAT:
955 case R_X86_64_JUMP_SLOT:
956 /* They don't need addend */
957 write64le(ptr, val - rel->r_addend);
958 break;
959 case R_X86_64_GOTPCREL:
960 case R_X86_64_GOTPCRELX:
961 case R_X86_64_REX_GOTPCRELX:
962 write32le(ptr, read32le(ptr) +
963 (s1->got->sh_addr - addr +
964 s1->sym_attrs[sym_index].got_offset - 4));
965 break;
966 case R_X86_64_GOTTPOFF:
967 write32le(ptr, read32le(ptr) + val - s1->got->sh_addr);
968 break;
969 case R_X86_64_GOT32:
970 /* we load the got offset */
971 write32le(ptr, read32le(ptr) + s1->sym_attrs[sym_index].got_offset);
972 break;
973 #else
974 #error unsupported processor
975 #endif
976 }
977 }
978 /* if the relocation is allocated, we change its symbol table */
979 if (sr->sh_flags & SHF_ALLOC)
980 sr->link = s1->dynsym;
981 }
982
983 /* relocate relocation table in 'sr' */
984 static void relocate_rel(TCCState *s1, Section *sr)
985 {
986 Section *s;
987 ElfW_Rel *rel;
988
989 s = s1->sections[sr->sh_info];
990 for_each_elem(sr, 0, rel, ElfW_Rel)
991 rel->r_offset += s->sh_addr;
992 }
993
994 /* count the number of dynamic relocations so that we can reserve
995 their space */
996 static int prepare_dynamic_rel(TCCState *s1, Section *sr)
997 {
998 ElfW_Rel *rel;
999 int sym_index, esym_index, type, count;
1000
1001 count = 0;
1002 for_each_elem(sr, 0, rel, ElfW_Rel) {
1003 sym_index = ELFW(R_SYM)(rel->r_info);
1004 type = ELFW(R_TYPE)(rel->r_info);
1005 switch(type) {
1006 #if defined(TCC_TARGET_I386)
1007 case R_386_32:
1008 #elif defined(TCC_TARGET_X86_64)
1009 case R_X86_64_32:
1010 case R_X86_64_32S:
1011 case R_X86_64_64:
1012 #endif
1013 count++;
1014 break;
1015 #if defined(TCC_TARGET_I386)
1016 case R_386_PC32:
1017 #elif defined(TCC_TARGET_X86_64)
1018 case R_X86_64_PC32:
1019 #endif
1020 esym_index = s1->symtab_to_dynsym[sym_index];
1021 if (esym_index)
1022 count++;
1023 break;
1024 default:
1025 break;
1026 }
1027 }
1028 if (count) {
1029 /* allocate the section */
1030 sr->sh_flags |= SHF_ALLOC;
1031 sr->sh_size = count * sizeof(ElfW_Rel);
1032 }
1033 return count;
1034 }
1035
1036 static struct sym_attr *alloc_sym_attr(TCCState *s1, int index)
1037 {
1038 int n;
1039 struct sym_attr *tab;
1040
1041 if (index >= s1->nb_sym_attrs) {
1042 /* find immediately bigger power of 2 and reallocate array */
1043 n = 1;
1044 while (index >= n)
1045 n *= 2;
1046 tab = tcc_realloc(s1->sym_attrs, n * sizeof(*s1->sym_attrs));
1047 s1->sym_attrs = tab;
1048 memset(s1->sym_attrs + s1->nb_sym_attrs, 0,
1049 (n - s1->nb_sym_attrs) * sizeof(*s1->sym_attrs));
1050 s1->nb_sym_attrs = n;
1051 }
1052 return &s1->sym_attrs[index];
1053 }
1054
1055 static void build_got(TCCState *s1)
1056 {
1057 unsigned char *ptr;
1058
1059 /* if no got, then create it */
1060 s1->got = new_section(s1, ".got", SHT_PROGBITS, SHF_ALLOC | SHF_WRITE);
1061 s1->got->sh_entsize = 4;
1062 add_elf_sym(symtab_section, 0, 4, ELFW(ST_INFO)(STB_GLOBAL, STT_OBJECT),
1063 0, s1->got->sh_num, "_GLOBAL_OFFSET_TABLE_");
1064 ptr = section_ptr_add(s1->got, 3 * PTR_SIZE);
1065 #if PTR_SIZE == 4
1066 /* keep space for _DYNAMIC pointer, if present */
1067 write32le(ptr, 0);
1068 /* two dummy got entries */
1069 write32le(ptr + 4, 0);
1070 write32le(ptr + 8, 0);
1071 #else
1072 /* keep space for _DYNAMIC pointer, if present */
1073 write32le(ptr, 0);
1074 write32le(ptr + 4, 0);
1075 /* two dummy got entries */
1076 write32le(ptr + 8, 0);
1077 write32le(ptr + 12, 0);
1078 write32le(ptr + 16, 0);
1079 write32le(ptr + 20, 0);
1080 #endif
1081 }
1082
1083 /* put a got or plt entry corresponding to a symbol in symtab_section. 'size'
1084 and 'info' can be modifed if more precise info comes from the DLL.
1085 Returns offset of GOT or PLT slot. */
1086 static unsigned long put_got_entry(TCCState *s1,
1087 int reloc_type, unsigned long size, int info,
1088 int sym_index)
1089 {
1090 int index, need_plt_entry;
1091 const char *name;
1092 ElfW(Sym) *sym;
1093 unsigned long offset;
1094 int *ptr;
1095 struct sym_attr *symattr;
1096
1097 if (!s1->got)
1098 build_got(s1);
1099
1100 need_plt_entry =
1101 #ifdef TCC_TARGET_X86_64
1102 (reloc_type == R_X86_64_JUMP_SLOT);
1103 #elif defined(TCC_TARGET_I386)
1104 (reloc_type == R_386_JMP_SLOT);
1105 #elif defined(TCC_TARGET_ARM)
1106 (reloc_type == R_ARM_JUMP_SLOT);
1107 #elif defined(TCC_TARGET_ARM64)
1108 (reloc_type == R_AARCH64_JUMP_SLOT);
1109 #else
1110 0;
1111 #endif
1112
1113 if (need_plt_entry && !s1->plt) {
1114 /* add PLT */
1115 s1->plt = new_section(s1, ".plt", SHT_PROGBITS,
1116 SHF_ALLOC | SHF_EXECINSTR);
1117 s1->plt->sh_entsize = 4;
1118 }
1119
1120 /* If a got/plt entry already exists for that symbol, no need to add one */
1121 if (sym_index < s1->nb_sym_attrs) {
1122 if (need_plt_entry && s1->sym_attrs[sym_index].plt_offset)
1123 return s1->sym_attrs[sym_index].plt_offset;
1124 else if (!need_plt_entry && s1->sym_attrs[sym_index].got_offset)
1125 return s1->sym_attrs[sym_index].got_offset;
1126 }
1127
1128 symattr = alloc_sym_attr(s1, sym_index);
1129
1130 /* Only store the GOT offset if it's not generated for the PLT entry. */
1131 if (!need_plt_entry)
1132 symattr->got_offset = s1->got->data_offset;
1133
1134 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1135 name = (char *) symtab_section->link->data + sym->st_name;
1136 offset = sym->st_value;
1137 #if defined(TCC_TARGET_I386) || defined(TCC_TARGET_X86_64)
1138 if (need_plt_entry) {
1139 Section *plt;
1140 uint8_t *p;
1141 int modrm;
1142 unsigned long relofs;
1143
1144 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
1145 modrm = 0x25;
1146 #else
1147 /* if we build a DLL, we add a %ebx offset */
1148 if (s1->output_type == TCC_OUTPUT_DLL)
1149 modrm = 0xa3;
1150 else
1151 modrm = 0x25;
1152 #endif
1153
1154 /* add a PLT entry */
1155 plt = s1->plt;
1156 if (plt->data_offset == 0) {
1157 /* first plt entry */
1158 p = section_ptr_add(plt, 16);
1159 p[0] = 0xff; /* pushl got + PTR_SIZE */
1160 p[1] = modrm + 0x10;
1161 write32le(p + 2, PTR_SIZE);
1162 p[6] = 0xff; /* jmp *(got + PTR_SIZE * 2) */
1163 p[7] = modrm;
1164 write32le(p + 8, PTR_SIZE * 2);
1165 }
1166
1167 /* The PLT slot refers to the relocation entry it needs
1168 via offset. The reloc entry is created below, so its
1169 offset is the current data_offset. */
1170 relofs = s1->got->reloc ? s1->got->reloc->data_offset : 0;
1171 symattr->plt_offset = plt->data_offset;
1172 p = section_ptr_add(plt, 16);
1173 p[0] = 0xff; /* jmp *(got + x) */
1174 p[1] = modrm;
1175 write32le(p + 2, s1->got->data_offset);
1176 p[6] = 0x68; /* push $xxx */
1177 #ifdef TCC_TARGET_X86_64
1178 /* On x86-64, the relocation is referred to by _index_. */
1179 write32le(p + 7, relofs / sizeof (ElfW_Rel));
1180 #else
1181 write32le(p + 7, relofs);
1182 #endif
1183 p[11] = 0xe9; /* jmp plt_start */
1184 write32le(p + 12, -(plt->data_offset));
1185
1186 /* If this was an UNDEF symbol set the offset in the
1187 dynsymtab to the PLT slot, so that PC32 relocs to it
1188 can be resolved. */
1189 if (sym->st_shndx == SHN_UNDEF)
1190 offset = plt->data_offset - 16;
1191 }
1192 #elif defined(TCC_TARGET_ARM)
1193 if (need_plt_entry) {
1194 Section *plt;
1195 uint8_t *p;
1196
1197 /* if we build a DLL, we add a %ebx offset */
1198 if (s1->output_type == TCC_OUTPUT_DLL)
1199 tcc_error("DLLs unimplemented!");
1200
1201 /* add a PLT entry */
1202 plt = s1->plt;
1203 if (plt->data_offset == 0) {
1204 /* first plt entry */
1205 p = section_ptr_add(plt, 16);
1206 write32le(p, 0xe52de004); /* push {lr} */
1207 write32le(p+4, 0xe59fe010); /* ldr lr, [pc, #16] */
1208 write32le(p+8, 0xe08fe00e); /* add lr, pc, lr */
1209 write32le(p+12, 0xe5bef008); /* ldr pc, [lr, #8]! */
1210 }
1211
1212 symattr->plt_offset = plt->data_offset;
1213 if (symattr->plt_thumb_stub) {
1214 p = section_ptr_add(plt, 20);
1215 write32le(p, 0x4778); /* bx pc */
1216 write32le(p+2, 0x46c0); /* nop */
1217 p += 4;
1218 } else
1219 p = section_ptr_add(plt, 16);
1220 write32le(p, 0xe59fc004); /* ldr ip, [pc, #4] ; GOT entry offset */
1221 write32le(p+4, 0xe08fc00c); /* add ip, pc, ip ; addr of GOT entry */
1222 write32le(p+8, 0xe59cf000); /* ldr pc, [ip] ; jump to GOT entry */
1223 write32le(p+12, s1->got->data_offset); /* GOT entry off once patched */
1224
1225 /* the symbol is modified so that it will be relocated to
1226 the PLT */
1227 if (sym->st_shndx == SHN_UNDEF)
1228 offset = plt->data_offset - 16;
1229 }
1230 #elif defined(TCC_TARGET_ARM64)
1231 if (need_plt_entry) {
1232 Section *plt;
1233 uint8_t *p;
1234
1235 if (s1->output_type == TCC_OUTPUT_DLL)
1236 tcc_error("DLLs unimplemented!");
1237
1238 plt = s1->plt;
1239 if (plt->data_offset == 0)
1240 section_ptr_add(plt, 32);
1241 symattr->plt_offset = plt->data_offset;
1242 p = section_ptr_add(plt, 16);
1243 write32le(p, s1->got->data_offset);
1244 write32le(p + 4, (uint64_t)s1->got->data_offset >> 32);
1245
1246 if (sym->st_shndx == SHN_UNDEF)
1247 offset = plt->data_offset - 16;
1248 }
1249 #elif defined(TCC_TARGET_C67)
1250 if (s1->dynsym) {
1251 tcc_error("C67 got not implemented");
1252 }
1253 #else
1254 #error unsupported CPU
1255 #endif
1256 if (s1->dynsym) {
1257 /* XXX This might generate multiple syms for name. */
1258 index = put_elf_sym(s1->dynsym, offset,
1259 size, info, 0, sym->st_shndx, name);
1260 /* Create the relocation (it's against the GOT for PLT
1261 and GOT relocs). */
1262 put_elf_reloc(s1->dynsym, s1->got,
1263 s1->got->data_offset,
1264 reloc_type, index);
1265 } else {
1266 /* Without .dynsym (i.e. static link or memory output) we
1267 still need relocs against the generated got, so as to fill
1268 the entries with the symbol values (determined later). */
1269 put_elf_reloc(symtab_section, s1->got,
1270 s1->got->data_offset,
1271 reloc_type, sym_index);
1272 }
1273 /* And now create the GOT slot itself. */
1274 ptr = section_ptr_add(s1->got, PTR_SIZE);
1275 *ptr = 0;
1276 if (need_plt_entry)
1277 return symattr->plt_offset;
1278 else
1279 return symattr->got_offset;
1280 }
1281
1282 /* build GOT and PLT entries */
1283 ST_FUNC void build_got_entries(TCCState *s1)
1284 {
1285 Section *s;
1286 ElfW_Rel *rel;
1287 ElfW(Sym) *sym;
1288 int i, type, reloc_type, sym_index;
1289
1290 for(i = 1; i < s1->nb_sections; i++) {
1291 s = s1->sections[i];
1292 if (s->sh_type != SHT_RELX)
1293 continue;
1294 /* no need to handle got relocations */
1295 if (s->link != symtab_section)
1296 continue;
1297 for_each_elem(s, 0, rel, ElfW_Rel) {
1298 type = ELFW(R_TYPE)(rel->r_info);
1299 switch(type) {
1300 #if defined(TCC_TARGET_I386)
1301 case R_386_GOT32:
1302 case R_386_GOT32X:
1303 case R_386_GOTOFF:
1304 case R_386_GOTPC:
1305 case R_386_PLT32:
1306 if (!s1->got)
1307 build_got(s1);
1308 if (type == R_386_GOT32 || type == R_386_GOT32X ||
1309 type == R_386_PLT32) {
1310 sym_index = ELFW(R_SYM)(rel->r_info);
1311 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1312 /* look at the symbol got offset. If none, then add one */
1313 if (type == R_386_GOT32 || type == R_386_GOT32X)
1314 reloc_type = R_386_GLOB_DAT;
1315 else
1316 reloc_type = R_386_JMP_SLOT;
1317 put_got_entry(s1, reloc_type, sym->st_size, sym->st_info,
1318 sym_index);
1319 }
1320 break;
1321 #elif defined(TCC_TARGET_ARM)
1322 case R_ARM_PC24:
1323 case R_ARM_CALL:
1324 case R_ARM_JUMP24:
1325 case R_ARM_GOT32:
1326 case R_ARM_GOTOFF:
1327 case R_ARM_GOTPC:
1328 case R_ARM_PLT32:
1329 if (!s1->got)
1330 build_got(s1);
1331 sym_index = ELFW(R_SYM)(rel->r_info);
1332 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1333 if (type != R_ARM_GOTOFF && type != R_ARM_GOTPC
1334 && sym->st_shndx == SHN_UNDEF) {
1335 unsigned long ofs;
1336 /* look at the symbol got offset. If none, then add one */
1337 if (type == R_ARM_GOT32)
1338 reloc_type = R_ARM_GLOB_DAT;
1339 else
1340 reloc_type = R_ARM_JUMP_SLOT;
1341 ofs = put_got_entry(s1, reloc_type, sym->st_size,
1342 sym->st_info, sym_index);
1343 #ifdef DEBUG_RELOC
1344 printf ("maybegot: %s, %d, %d --> ofs=0x%x\n",
1345 (char *) symtab_section->link->data + sym->st_name,
1346 type, sym->st_shndx, ofs);
1347 #endif
1348 if (type != R_ARM_GOT32) {
1349 addr_t *ptr = (addr_t*)(s1->sections[s->sh_info]->data
1350 + rel->r_offset);
1351 /* x must be signed! */
1352 int x = *ptr & 0xffffff;
1353 x = (x << 8) >> 8;
1354 x <<= 2;
1355 x += ofs;
1356 x >>= 2;
1357 #ifdef DEBUG_RELOC
1358 printf ("insn=0x%x --> 0x%x (x==0x%x)\n", *ptr,
1359 (*ptr & 0xff000000) | x, x);
1360 #endif
1361 *ptr = (*ptr & 0xff000000) | x;
1362 }
1363 }
1364 break;
1365 case R_ARM_THM_JUMP24:
1366 sym_index = ELFW(R_SYM)(rel->r_info);
1367 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1368 /* We are relocating a jump from thumb code to arm code */
1369 if (sym->st_shndx != SHN_UNDEF && !(sym->st_value & 1)) {
1370 int index;
1371 uint8_t *p;
1372 char *name, buf[1024];
1373 Section *text_section;
1374
1375 name = (char *) symtab_section->link->data + sym->st_name;
1376 text_section = s1->sections[sym->st_shndx];
1377 /* Modify reloc to target a thumb stub to switch to ARM */
1378 snprintf(buf, sizeof(buf), "%s_from_thumb", name);
1379 index = put_elf_sym(symtab_section,
1380 text_section->data_offset + 1,
1381 sym->st_size, sym->st_info, 0,
1382 sym->st_shndx, buf);
1383 rel->r_info = ELFW(R_INFO)(index, type);
1384 /* Create a thumb stub fonction to switch to ARM mode */
1385 put_elf_reloc(symtab_section, text_section,
1386 text_section->data_offset + 4, R_ARM_JUMP24,
1387 sym_index);
1388 p = section_ptr_add(text_section, 8);
1389 write32le(p, 0x4778); /* bx pc */
1390 write32le(p+2, 0x46c0); /* nop */
1391 write32le(p+4, 0xeafffffe); /* b $sym */
1392 }
1393 #elif defined(TCC_TARGET_ARM64)
1394 //xx Other cases may be required here:
1395 case R_AARCH64_ADR_GOT_PAGE:
1396 case R_AARCH64_LD64_GOT_LO12_NC:
1397 if (!s1->got)
1398 build_got(s1);
1399 sym_index = ELFW(R_SYM)(rel->r_info);
1400 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1401 reloc_type = R_AARCH64_GLOB_DAT;
1402 put_got_entry(s1, reloc_type, sym->st_size, sym->st_info,
1403 sym_index);
1404 break;
1405
1406 case R_AARCH64_JUMP26:
1407 case R_AARCH64_CALL26:
1408 if (!s1->got)
1409 build_got(s1);
1410 sym_index = ELFW(R_SYM)(rel->r_info);
1411 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1412 if (sym->st_shndx == SHN_UNDEF) {
1413 unsigned long ofs;
1414 reloc_type = R_AARCH64_JUMP_SLOT;
1415 ofs = put_got_entry(s1, reloc_type, sym->st_size,
1416 sym->st_info, sym_index);
1417 /* We store the place of the generated PLT slot
1418 in our addend. */
1419 rel->r_addend += ofs;
1420 }
1421 break;
1422 #elif defined(TCC_TARGET_C67)
1423 case R_C60_GOT32:
1424 case R_C60_GOTOFF:
1425 case R_C60_GOTPC:
1426 case R_C60_PLT32:
1427 if (!s1->got)
1428 build_got(s1);
1429 if (type == R_C60_GOT32 || type == R_C60_PLT32) {
1430 sym_index = ELFW(R_SYM)(rel->r_info);
1431 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1432 /* look at the symbol got offset. If none, then add one */
1433 if (type == R_C60_GOT32)
1434 reloc_type = R_C60_GLOB_DAT;
1435 else
1436 reloc_type = R_C60_JMP_SLOT;
1437 put_got_entry(s1, reloc_type, sym->st_size, sym->st_info,
1438 sym_index);
1439 }
1440 break;
1441 #elif defined(TCC_TARGET_X86_64)
1442 case R_X86_64_GOT32:
1443 case R_X86_64_GOTTPOFF:
1444 case R_X86_64_GOTPCREL:
1445 case R_X86_64_GOTPCRELX:
1446 case R_X86_64_REX_GOTPCRELX:
1447 case R_X86_64_PLT32:
1448 sym_index = ELFW(R_SYM)(rel->r_info);
1449 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1450 if (type == R_X86_64_PLT32 &&
1451 ELFW(ST_VISIBILITY)(sym->st_other) != STV_DEFAULT)
1452 {
1453 rel->r_info = ELFW(R_INFO)(sym_index, R_X86_64_PC32);
1454 break;
1455 }
1456
1457 if (!s1->got) {
1458 build_got(s1);
1459 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1460 }
1461 if (type == R_X86_64_GOT32 || type == R_X86_64_GOTPCREL ||
1462 type == R_X86_64_GOTPCRELX ||
1463 type == R_X86_64_REX_GOTPCRELX ||
1464 type == R_X86_64_PLT32) {
1465 unsigned long ofs;
1466 /* look at the symbol got offset. If none, then add one */
1467 if (type == R_X86_64_PLT32)
1468 reloc_type = R_X86_64_JUMP_SLOT;
1469 else
1470 reloc_type = R_X86_64_GLOB_DAT;
1471 ofs = put_got_entry(s1, reloc_type, sym->st_size,
1472 sym->st_info, sym_index);
1473 if (type == R_X86_64_PLT32)
1474 /* We store the place of the generated PLT slot
1475 in our addend. */
1476 rel->r_addend += ofs;
1477 }
1478 break;
1479 #else
1480 #error unsupported CPU
1481 #endif
1482 default:
1483 break;
1484 }
1485 }
1486 }
1487 }
1488
1489 ST_FUNC Section *new_symtab(TCCState *s1,
1490 const char *symtab_name, int sh_type, int sh_flags,
1491 const char *strtab_name,
1492 const char *hash_name, int hash_sh_flags)
1493 {
1494 Section *symtab, *strtab, *hash;
1495 int *ptr, nb_buckets;
1496
1497 symtab = new_section(s1, symtab_name, sh_type, sh_flags);
1498 symtab->sh_entsize = sizeof(ElfW(Sym));
1499 strtab = new_section(s1, strtab_name, SHT_STRTAB, sh_flags);
1500 put_elf_str(strtab, "");
1501 symtab->link = strtab;
1502 put_elf_sym(symtab, 0, 0, 0, 0, 0, NULL);
1503
1504 nb_buckets = 1;
1505
1506 hash = new_section(s1, hash_name, SHT_HASH, hash_sh_flags);
1507 hash->sh_entsize = sizeof(int);
1508 symtab->hash = hash;
1509 hash->link = symtab;
1510
1511 ptr = section_ptr_add(hash, (2 + nb_buckets + 1) * sizeof(int));
1512 ptr[0] = nb_buckets;
1513 ptr[1] = 1;
1514 memset(ptr + 2, 0, (nb_buckets + 1) * sizeof(int));
1515 return symtab;
1516 }
1517
1518 /* put dynamic tag */
1519 static void put_dt(Section *dynamic, int dt, addr_t val)
1520 {
1521 ElfW(Dyn) *dyn;
1522 dyn = section_ptr_add(dynamic, sizeof(ElfW(Dyn)));
1523 dyn->d_tag = dt;
1524 dyn->d_un.d_val = val;
1525 }
1526
1527 static void add_init_array_defines(TCCState *s1, const char *section_name)
1528 {
1529 Section *s;
1530 long end_offset;
1531 char sym_start[1024];
1532 char sym_end[1024];
1533
1534 snprintf(sym_start, sizeof(sym_start), "__%s_start", section_name + 1);
1535 snprintf(sym_end, sizeof(sym_end), "__%s_end", section_name + 1);
1536
1537 s = find_section(s1, section_name);
1538 if (!s) {
1539 end_offset = 0;
1540 s = data_section;
1541 } else {
1542 end_offset = s->data_offset;
1543 }
1544
1545 add_elf_sym(symtab_section,
1546 0, 0,
1547 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1548 s->sh_num, sym_start);
1549 add_elf_sym(symtab_section,
1550 end_offset, 0,
1551 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1552 s->sh_num, sym_end);
1553 }
1554
1555 static int tcc_add_support(TCCState *s1, const char *filename)
1556 {
1557 char buf[1024];
1558 snprintf(buf, sizeof(buf), "%s/%s/%s", s1->tcc_lib_path,
1559 /* an cpu specific path inside tcc_lib_path, mainly for keeping libtcc1.a */
1560 #ifdef TCC_TARGET_I386
1561 "i386"
1562 #endif
1563 #ifdef TCC_TARGET_X86_64
1564 "x86-64"
1565 #endif
1566 #ifdef TCC_TARGET_ARM
1567 "arm"
1568 #endif
1569 #ifdef TCC_TARGET_ARM64
1570 "arm64"
1571 #endif
1572 #ifdef TCC_TARGET_C67
1573 "C67"
1574 #endif
1575 ,filename);
1576 return tcc_add_file(s1, buf);
1577 }
1578
1579 ST_FUNC void tcc_add_bcheck(TCCState *s1)
1580 {
1581 #ifdef CONFIG_TCC_BCHECK
1582 addr_t *ptr;
1583 int sym_index;
1584
1585 if (0 == s1->do_bounds_check)
1586 return;
1587 /* XXX: add an object file to do that */
1588 ptr = section_ptr_add(bounds_section, sizeof(*ptr));
1589 *ptr = 0;
1590 add_elf_sym(symtab_section, 0, 0,
1591 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1592 bounds_section->sh_num, "__bounds_start");
1593 /* pull bcheck.o from libtcc1.a */
1594 sym_index = add_elf_sym(symtab_section, 0, 0,
1595 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1596 SHN_UNDEF, "__bound_init");
1597 if (s1->output_type != TCC_OUTPUT_MEMORY) {
1598 /* add 'call __bound_init()' in .init section */
1599 Section *init_section = find_section(s1, ".init");
1600 unsigned char *pinit = section_ptr_add(init_section, 5);
1601 pinit[0] = 0xe8;
1602 write32le(pinit + 1, -4);
1603 put_elf_reloc(symtab_section, init_section,
1604 init_section->data_offset - 4, R_386_PC32, sym_index);
1605 /* R_386_PC32 = R_X86_64_PC32 = 2 */
1606 }
1607 #endif
1608 }
1609
1610 /* add tcc runtime libraries */
1611 ST_FUNC void tcc_add_runtime(TCCState *s1)
1612 {
1613 tcc_add_bcheck(s1);
1614 tcc_add_pragma_libs(s1);
1615 /* add libc */
1616 if (!s1->nostdlib) {
1617 tcc_add_library(s1, "c");
1618 #ifdef CONFIG_USE_LIBGCC
1619 if (!s1->static_link) {
1620 tcc_add_file(s1, TCC_LIBGCC);
1621 }
1622 #endif
1623 tcc_add_support(s1, "libtcc1.a");
1624 /* add crt end if not memory output */
1625 if (s1->output_type != TCC_OUTPUT_MEMORY)
1626 tcc_add_crt(s1, "crtn.o");
1627 }
1628 }
1629
1630 /* add various standard linker symbols (must be done after the
1631 sections are filled (for example after allocating common
1632 symbols)) */
1633 ST_FUNC void tcc_add_linker_symbols(TCCState *s1)
1634 {
1635 char buf[1024];
1636 int i;
1637 Section *s;
1638
1639 add_elf_sym(symtab_section,
1640 text_section->data_offset, 0,
1641 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1642 text_section->sh_num, "_etext");
1643 add_elf_sym(symtab_section,
1644 data_section->data_offset, 0,
1645 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1646 data_section->sh_num, "_edata");
1647 add_elf_sym(symtab_section,
1648 bss_section->data_offset, 0,
1649 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1650 bss_section->sh_num, "_end");
1651 /* horrible new standard ldscript defines */
1652 add_init_array_defines(s1, ".preinit_array");
1653 add_init_array_defines(s1, ".init_array");
1654 add_init_array_defines(s1, ".fini_array");
1655
1656 /* add start and stop symbols for sections whose name can be
1657 expressed in C */
1658 for(i = 1; i < s1->nb_sections; i++) {
1659 s = s1->sections[i];
1660 if (s->sh_type == SHT_PROGBITS &&
1661 (s->sh_flags & SHF_ALLOC)) {
1662 const char *p;
1663 int ch;
1664
1665 /* check if section name can be expressed in C */
1666 p = s->name;
1667 for(;;) {
1668 ch = *p;
1669 if (!ch)
1670 break;
1671 if (!isid(ch) && !isnum(ch))
1672 goto next_sec;
1673 p++;
1674 }
1675 snprintf(buf, sizeof(buf), "__start_%s", s->name);
1676 add_elf_sym(symtab_section,
1677 0, 0,
1678 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1679 s->sh_num, buf);
1680 snprintf(buf, sizeof(buf), "__stop_%s", s->name);
1681 add_elf_sym(symtab_section,
1682 s->data_offset, 0,
1683 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1684 s->sh_num, buf);
1685 }
1686 next_sec: ;
1687 }
1688 }
1689
1690 static void tcc_output_binary(TCCState *s1, FILE *f,
1691 const int *sec_order)
1692 {
1693 Section *s;
1694 int i, offset, size;
1695
1696 offset = 0;
1697 for(i=1;i<s1->nb_sections;i++) {
1698 s = s1->sections[sec_order[i]];
1699 if (s->sh_type != SHT_NOBITS &&
1700 (s->sh_flags & SHF_ALLOC)) {
1701 while (offset < s->sh_offset) {
1702 fputc(0, f);
1703 offset++;
1704 }
1705 size = s->sh_size;
1706 fwrite(s->data, 1, size, f);
1707 offset += size;
1708 }
1709 }
1710 }
1711
1712 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1713 #define HAVE_PHDR 1
1714 #define EXTRA_RELITEMS 14
1715
1716 /* move the relocation value from .dynsym to .got */
1717 static void patch_dynsym_undef(TCCState *s1, Section *s)
1718 {
1719 uint32_t *gotd = (void *)s1->got->data;
1720 ElfW(Sym) *sym;
1721
1722 gotd += 3; /* dummy entries in .got */
1723 /* relocate symbols in .dynsym */
1724 for_each_elem(s, 1, sym, ElfW(Sym)) {
1725 if (sym->st_shndx == SHN_UNDEF) {
1726 *gotd++ = sym->st_value + 6; /* XXX 6 is magic ? */
1727 sym->st_value = 0;
1728 }
1729 }
1730 }
1731 #else
1732 #define HAVE_PHDR 1
1733 #define EXTRA_RELITEMS 9
1734
1735 /* zero plt offsets of weak symbols in .dynsym */
1736 static void patch_dynsym_undef(TCCState *s1, Section *s)
1737 {
1738 ElfW(Sym) *sym;
1739
1740 for_each_elem(s, 1, sym, ElfW(Sym))
1741 if (sym->st_shndx == SHN_UNDEF && ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
1742 sym->st_value = 0;
1743 }
1744 #endif
1745
1746 ST_FUNC void fill_got_entry(TCCState *s1, ElfW_Rel *rel)
1747 {
1748 int sym_index = ELFW(R_SYM) (rel->r_info);
1749 ElfW(Sym) *sym = &((ElfW(Sym) *) symtab_section->data)[sym_index];
1750 unsigned long offset;
1751
1752 if (sym_index >= s1->nb_sym_attrs)
1753 return;
1754 offset = s1->sym_attrs[sym_index].got_offset;
1755 section_reserve(s1->got, offset + PTR_SIZE);
1756 #ifdef TCC_TARGET_X86_64
1757 /* only works for x86-64 */
1758 write32le(s1->got->data + offset + 4, sym->st_value >> 32);
1759 #endif
1760 write32le(s1->got->data + offset, sym->st_value & 0xffffffff);
1761 }
1762
1763 /* Perform relocation to GOT or PLT entries */
1764 ST_FUNC void fill_got(TCCState *s1)
1765 {
1766 Section *s;
1767 ElfW_Rel *rel;
1768 int i;
1769
1770 for(i = 1; i < s1->nb_sections; i++) {
1771 s = s1->sections[i];
1772 if (s->sh_type != SHT_RELX)
1773 continue;
1774 /* no need to handle got relocations */
1775 if (s->link != symtab_section)
1776 continue;
1777 for_each_elem(s, 0, rel, ElfW_Rel) {
1778 switch (ELFW(R_TYPE) (rel->r_info)) {
1779 case R_X86_64_GOT32:
1780 case R_X86_64_GOTPCREL:
1781 case R_X86_64_GOTPCRELX:
1782 case R_X86_64_REX_GOTPCRELX:
1783 case R_X86_64_PLT32:
1784 fill_got_entry(s1, rel);
1785 break;
1786 }
1787 }
1788 }
1789 }
1790
1791 /* Bind symbols of executable: resolve undefined symbols from exported symbols
1792 in shared libraries and export non local defined symbols to shared libraries
1793 if -rdynamic switch was given on command line */
1794 static void bind_exe_dynsyms(TCCState *s1)
1795 {
1796 const char *name;
1797 int sym_index, index;
1798 ElfW(Sym) *sym, *esym;
1799 int type;
1800
1801 /* Resolve undefined symbols from dynamic symbols. When there is a match:
1802 - if STT_FUNC or STT_GNU_IFUNC symbol -> add it in PLT
1803 - if STT_OBJECT symbol -> add it in .bss section with suitable reloc */
1804 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
1805 if (sym->st_shndx == SHN_UNDEF) {
1806 name = (char *) symtab_section->link->data + sym->st_name;
1807 sym_index = find_elf_sym(s1->dynsymtab_section, name);
1808 if (sym_index) {
1809 esym = &((ElfW(Sym) *)s1->dynsymtab_section->data)[sym_index];
1810 type = ELFW(ST_TYPE)(esym->st_info);
1811 if ((type == STT_FUNC) || (type == STT_GNU_IFUNC)) {
1812 /* Indirect functions shall have STT_FUNC type in executable
1813 * dynsym section. Indeed, a dlsym call following a lazy
1814 * resolution would pick the symbol value from the
1815 * executable dynsym entry which would contain the address
1816 * of the function wanted by the caller of dlsym instead of
1817 * the address of the function that would return that
1818 * address */
1819 put_got_entry(s1, R_JMP_SLOT, esym->st_size,
1820 ELFW(ST_INFO)(STB_GLOBAL,STT_FUNC),
1821 sym - (ElfW(Sym) *)symtab_section->data);
1822 } else if (type == STT_OBJECT) {
1823 unsigned long offset;
1824 ElfW(Sym) *dynsym;
1825 offset = bss_section->data_offset;
1826 /* XXX: which alignment ? */
1827 offset = (offset + 16 - 1) & -16;
1828 index = put_elf_sym(s1->dynsym, offset, esym->st_size,
1829 esym->st_info, 0, bss_section->sh_num,
1830 name);
1831 /* Ensure R_COPY works for weak symbol aliases */
1832 if (ELFW(ST_BIND)(esym->st_info) == STB_WEAK) {
1833 for_each_elem(s1->dynsymtab_section, 1, dynsym, ElfW(Sym)) {
1834 if ((dynsym->st_value == esym->st_value)
1835 && (ELFW(ST_BIND)(dynsym->st_info) == STB_GLOBAL)) {
1836 char *dynname = (char *) s1->dynsymtab_section->link->data
1837 + dynsym->st_name;
1838 put_elf_sym(s1->dynsym, offset, dynsym->st_size,
1839 dynsym->st_info, 0,
1840 bss_section->sh_num, dynname);
1841 break;
1842 }
1843 }
1844 }
1845 put_elf_reloc(s1->dynsym, bss_section,
1846 offset, R_COPY, index);
1847 offset += esym->st_size;
1848 bss_section->data_offset = offset;
1849 }
1850 } else {
1851 /* STB_WEAK undefined symbols are accepted */
1852 /* XXX: _fp_hw seems to be part of the ABI, so we ignore it */
1853 if (ELFW(ST_BIND)(sym->st_info) == STB_WEAK ||
1854 !strcmp(name, "_fp_hw")) {
1855 } else {
1856 tcc_error_noabort("undefined symbol '%s'", name);
1857 }
1858 }
1859 } else if (s1->rdynamic && ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
1860 /* if -rdynamic option, then export all non local symbols */
1861 name = (char *) symtab_section->link->data + sym->st_name;
1862 put_elf_sym(s1->dynsym, sym->st_value, sym->st_size, sym->st_info,
1863 0, sym->st_shndx, name);
1864 }
1865 }
1866 }
1867
1868 /* Bind symbols of libraries: export non local symbols of executable that
1869 resolve undefined symbols of shared libraries */
1870 static void bind_libs_dynsyms(TCCState *s1)
1871 {
1872 const char *name;
1873 int sym_index;
1874 ElfW(Sym) *sym, *esym;
1875
1876 /* now look at unresolved dynamic symbols and export
1877 corresponding symbol */
1878 for_each_elem(s1->dynsymtab_section, 1, esym, ElfW(Sym)) {
1879 name = (char *) s1->dynsymtab_section->link->data + esym->st_name;
1880 sym_index = find_elf_sym(symtab_section, name);
1881 if (sym_index) {
1882 /* XXX: avoid adding a symbol if already present because of
1883 -rdynamic ? */
1884 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1885 if (sym->st_shndx != SHN_UNDEF)
1886 put_elf_sym(s1->dynsym, sym->st_value, sym->st_size,
1887 sym->st_info, 0, sym->st_shndx, name);
1888 } else if (esym->st_shndx == SHN_UNDEF) {
1889 /* weak symbols can stay undefined */
1890 if (ELFW(ST_BIND)(esym->st_info) != STB_WEAK)
1891 tcc_warning("undefined dynamic symbol '%s'", name);
1892 }
1893 }
1894 }
1895
1896 /* Export all non local symbols (for shared libraries) */
1897 static void export_global_syms(TCCState *s1)
1898 {
1899 int nb_syms, dynindex, index;
1900 const char *name;
1901 ElfW(Sym) *sym;
1902
1903 nb_syms = symtab_section->data_offset / sizeof(ElfW(Sym));
1904 s1->symtab_to_dynsym = tcc_mallocz(sizeof(int) * nb_syms);
1905 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
1906 if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
1907 name = (char *) symtab_section->link->data + sym->st_name;
1908 dynindex = put_elf_sym(s1->dynsym, sym->st_value, sym->st_size,
1909 sym->st_info, 0, sym->st_shndx, name);
1910 index = sym - (ElfW(Sym) *) symtab_section->data;
1911 s1->symtab_to_dynsym[index] = dynindex;
1912 }
1913 }
1914 }
1915
1916 /* relocate the PLT: compute addresses and offsets in the PLT now that final
1917 address for PLT and GOT are known (see fill_program_header) */
1918 ST_FUNC void relocate_plt(TCCState *s1)
1919 {
1920 uint8_t *p, *p_end;
1921
1922 if (!s1->plt)
1923 return;
1924
1925 p = s1->plt->data;
1926 p_end = p + s1->plt->data_offset;
1927 if (p < p_end) {
1928 #if defined(TCC_TARGET_I386)
1929 write32le(p + 2, read32le(p + 2) + s1->got->sh_addr);
1930 write32le(p + 8, read32le(p + 8) + s1->got->sh_addr);
1931 p += 16;
1932 while (p < p_end) {
1933 write32le(p + 2, read32le(p + 2) + s1->got->sh_addr);
1934 p += 16;
1935 }
1936 #elif defined(TCC_TARGET_X86_64)
1937 int x = s1->got->sh_addr - s1->plt->sh_addr - 6;
1938 write32le(p + 2, read32le(p + 2) + x);
1939 write32le(p + 8, read32le(p + 8) + x - 6);
1940 p += 16;
1941 while (p < p_end) {
1942 write32le(p + 2, read32le(p + 2) + x + s1->plt->data - p);
1943 p += 16;
1944 }
1945 #elif defined(TCC_TARGET_ARM)
1946 int x;
1947 x=s1->got->sh_addr - s1->plt->sh_addr - 12;
1948 p += 16;
1949 while (p < p_end) {
1950 if (read32le(p) == 0x46c04778) /* PLT Thumb stub present */
1951 p += 4;
1952 write32le(p + 12, x + read32le(p + 12) + s1->plt->data - p);
1953 p += 16;
1954 }
1955 #elif defined(TCC_TARGET_ARM64)
1956 uint64_t plt = s1->plt->sh_addr;
1957 uint64_t got = s1->got->sh_addr;
1958 uint64_t off = (got >> 12) - (plt >> 12);
1959 if ((off + ((uint32_t)1 << 20)) >> 21)
1960 tcc_error("Failed relocating PLT (off=0x%lx, got=0x%lx, plt=0x%lx)", off, got, plt);
1961 write32le(p, 0xa9bf7bf0); // stp x16,x30,[sp,#-16]!
1962 write32le(p + 4, (0x90000010 | // adrp x16,...
1963 (off & 0x1ffffc) << 3 | (off & 3) << 29));
1964 write32le(p + 8, (0xf9400211 | // ldr x17,[x16,#...]
1965 (got & 0xff8) << 7));
1966 write32le(p + 12, (0x91000210 | // add x16,x16,#...
1967 (got & 0xfff) << 10));
1968 write32le(p + 16, 0xd61f0220); // br x17
1969 write32le(p + 20, 0xd503201f); // nop
1970 write32le(p + 24, 0xd503201f); // nop
1971 write32le(p + 28, 0xd503201f); // nop
1972 p += 32;
1973 while (p < p_end) {
1974 uint64_t pc = plt + (p - s1->plt->data);
1975 uint64_t addr = got + read64le(p);
1976 uint64_t off = (addr >> 12) - (pc >> 12);
1977 if ((off + ((uint32_t)1 << 20)) >> 21)
1978 tcc_error("Failed relocating PLT (off=0x%lx, addr=0x%lx, pc=0x%lx)", off, addr, pc);
1979 write32le(p, (0x90000010 | // adrp x16,...
1980 (off & 0x1ffffc) << 3 | (off & 3) << 29));
1981 write32le(p + 4, (0xf9400211 | // ldr x17,[x16,#...]
1982 (addr & 0xff8) << 7));
1983 write32le(p + 8, (0x91000210 | // add x16,x16,#...
1984 (addr & 0xfff) << 10));
1985 write32le(p + 12, 0xd61f0220); // br x17
1986 p += 16;
1987 }
1988 #elif defined(TCC_TARGET_C67)
1989 /* XXX: TODO */
1990 #else
1991 #error unsupported CPU
1992 #endif
1993 }
1994 }
1995
1996 /* Allocate strings for section names and decide if an unallocated section
1997 should be output.
1998
1999 NOTE: the strsec section comes last, so its size is also correct ! */
2000 static void alloc_sec_names(TCCState *s1, int file_type, Section *strsec)
2001 {
2002 int i;
2003 Section *s;
2004
2005 /* Allocate strings for section names */
2006 for(i = 1; i < s1->nb_sections; i++) {
2007 s = s1->sections[i];
2008 s->sh_name = put_elf_str(strsec, s->name);
2009 /* when generating a DLL, we include relocations but we may
2010 patch them */
2011 if (file_type == TCC_OUTPUT_DLL &&
2012 s->sh_type == SHT_RELX &&
2013 !(s->sh_flags & SHF_ALLOC)) {
2014 /* gr: avoid bogus relocs for empty (debug) sections */
2015 if (s1->sections[s->sh_info]->sh_flags & SHF_ALLOC)
2016 prepare_dynamic_rel(s1, s);
2017 else if (s1->do_debug)
2018 s->sh_size = s->data_offset;
2019 } else if (s1->do_debug ||
2020 file_type == TCC_OUTPUT_OBJ ||
2021 (s->sh_flags & SHF_ALLOC) ||
2022 i == (s1->nb_sections - 1)) {
2023 /* we output all sections if debug or object file */
2024 s->sh_size = s->data_offset;
2025 }
2026 }
2027 }
2028
2029 /* Info to be copied in dynamic section */
2030 struct dyn_inf {
2031 Section *dynamic;
2032 Section *dynstr;
2033 unsigned long dyn_rel_off;
2034 addr_t rel_addr;
2035 addr_t rel_size;
2036 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2037 addr_t bss_addr;
2038 addr_t bss_size;
2039 #endif
2040 };
2041
2042 /* Assign sections to segments and decide how are sections laid out when loaded
2043 in memory. This function also fills corresponding program headers. */
2044 static int layout_sections(TCCState *s1, ElfW(Phdr) *phdr, int phnum,
2045 Section *interp, Section* strsec,
2046 struct dyn_inf *dyninf, int *sec_order)
2047 {
2048 int i, j, k, file_type, sh_order_index, file_offset;
2049 unsigned long s_align;
2050 long long tmp;
2051 addr_t addr;
2052 ElfW(Phdr) *ph;
2053 Section *s;
2054
2055 file_type = s1->output_type;
2056 sh_order_index = 1;
2057 file_offset = 0;
2058 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF)
2059 file_offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr));
2060 s_align = ELF_PAGE_SIZE;
2061 if (s1->section_align)
2062 s_align = s1->section_align;
2063
2064 if (phnum > 0) {
2065 if (s1->has_text_addr) {
2066 int a_offset, p_offset;
2067 addr = s1->text_addr;
2068 /* we ensure that (addr % ELF_PAGE_SIZE) == file_offset %
2069 ELF_PAGE_SIZE */
2070 a_offset = (int) (addr & (s_align - 1));
2071 p_offset = file_offset & (s_align - 1);
2072 if (a_offset < p_offset)
2073 a_offset += s_align;
2074 file_offset += (a_offset - p_offset);
2075 } else {
2076 if (file_type == TCC_OUTPUT_DLL)
2077 addr = 0;
2078 else
2079 addr = ELF_START_ADDR;
2080 /* compute address after headers */
2081 addr += (file_offset & (s_align - 1));
2082 }
2083
2084 ph = &phdr[0];
2085 /* Leave one program headers for the program interpreter and one for
2086 the program header table itself if needed. These are done later as
2087 they require section layout to be done first. */
2088 if (interp)
2089 ph += 1 + HAVE_PHDR;
2090
2091 /* dynamic relocation table information, for .dynamic section */
2092 dyninf->rel_addr = dyninf->rel_size = 0;
2093 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2094 dyninf->bss_addr = dyninf->bss_size = 0;
2095 #endif
2096
2097 for(j = 0; j < 2; j++) {
2098 ph->p_type = PT_LOAD;
2099 if (j == 0)
2100 ph->p_flags = PF_R | PF_X;
2101 else
2102 ph->p_flags = PF_R | PF_W;
2103 ph->p_align = s_align;
2104
2105 /* Decide the layout of sections loaded in memory. This must
2106 be done before program headers are filled since they contain
2107 info about the layout. We do the following ordering: interp,
2108 symbol tables, relocations, progbits, nobits */
2109 /* XXX: do faster and simpler sorting */
2110 for(k = 0; k < 5; k++) {
2111 for(i = 1; i < s1->nb_sections; i++) {
2112 s = s1->sections[i];
2113 /* compute if section should be included */
2114 if (j == 0) {
2115 if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) !=
2116 SHF_ALLOC)
2117 continue;
2118 } else {
2119 if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) !=
2120 (SHF_ALLOC | SHF_WRITE))
2121 continue;
2122 }
2123 if (s == interp) {
2124 if (k != 0)
2125 continue;
2126 } else if (s->sh_type == SHT_DYNSYM ||
2127 s->sh_type == SHT_STRTAB ||
2128 s->sh_type == SHT_HASH) {
2129 if (k != 1)
2130 continue;
2131 } else if (s->sh_type == SHT_RELX) {
2132 if (k != 2)
2133 continue;
2134 } else if (s->sh_type == SHT_NOBITS) {
2135 if (k != 4)
2136 continue;
2137 } else {
2138 if (k != 3)
2139 continue;
2140 }
2141 sec_order[sh_order_index++] = i;
2142
2143 /* section matches: we align it and add its size */
2144 tmp = addr;
2145 addr = (addr + s->sh_addralign - 1) &
2146 ~(s->sh_addralign - 1);
2147 file_offset += (int) ( addr - tmp );
2148 s->sh_offset = file_offset;
2149 s->sh_addr = addr;
2150
2151 /* update program header infos */
2152 if (ph->p_offset == 0) {
2153 ph->p_offset = file_offset;
2154 ph->p_vaddr = addr;
2155 ph->p_paddr = ph->p_vaddr;
2156 }
2157 /* update dynamic relocation infos */
2158 if (s->sh_type == SHT_RELX) {
2159 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2160 if (!strcmp(strsec->data + s->sh_name, ".rel.got")) {
2161 dyninf->rel_addr = addr;
2162 dyninf->rel_size += s->sh_size; /* XXX only first rel. */
2163 }
2164 if (!strcmp(strsec->data + s->sh_name, ".rel.bss")) {
2165 dyninf->bss_addr = addr;
2166 dyninf->bss_size = s->sh_size; /* XXX only first rel. */
2167 }
2168 #else
2169 if (dyninf->rel_size == 0)
2170 dyninf->rel_addr = addr;
2171 dyninf->rel_size += s->sh_size;
2172 #endif
2173 }
2174 addr += s->sh_size;
2175 if (s->sh_type != SHT_NOBITS)
2176 file_offset += s->sh_size;
2177 }
2178 }
2179 if (j == 0) {
2180 /* Make the first PT_LOAD segment include the program
2181 headers itself (and the ELF header as well), it'll
2182 come out with same memory use but will make various
2183 tools like binutils strip work better. */
2184 ph->p_offset &= ~(ph->p_align - 1);
2185 ph->p_vaddr &= ~(ph->p_align - 1);
2186 ph->p_paddr &= ~(ph->p_align - 1);
2187 }
2188 ph->p_filesz = file_offset - ph->p_offset;
2189 ph->p_memsz = addr - ph->p_vaddr;
2190 ph++;
2191 if (j == 0) {
2192 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF) {
2193 /* if in the middle of a page, we duplicate the page in
2194 memory so that one copy is RX and the other is RW */
2195 if ((addr & (s_align - 1)) != 0)
2196 addr += s_align;
2197 } else {
2198 addr = (addr + s_align - 1) & ~(s_align - 1);
2199 file_offset = (file_offset + s_align - 1) & ~(s_align - 1);
2200 }
2201 }
2202 }
2203 }
2204
2205 /* all other sections come after */
2206 for(i = 1; i < s1->nb_sections; i++) {
2207 s = s1->sections[i];
2208 if (phnum > 0 && (s->sh_flags & SHF_ALLOC))
2209 continue;
2210 sec_order[sh_order_index++] = i;
2211
2212 file_offset = (file_offset + s->sh_addralign - 1) &
2213 ~(s->sh_addralign - 1);
2214 s->sh_offset = file_offset;
2215 if (s->sh_type != SHT_NOBITS)
2216 file_offset += s->sh_size;
2217 }
2218
2219 return file_offset;
2220 }
2221
2222 static void fill_unloadable_phdr(ElfW(Phdr) *phdr, int phnum, Section *interp,
2223 Section *dynamic)
2224 {
2225 ElfW(Phdr) *ph;
2226
2227 /* if interpreter, then add corresponding program header */
2228 if (interp) {
2229 ph = &phdr[0];
2230
2231 if (HAVE_PHDR)
2232 {
2233 int len = phnum * sizeof(ElfW(Phdr));
2234
2235 ph->p_type = PT_PHDR;
2236 ph->p_offset = sizeof(ElfW(Ehdr));
2237 ph->p_vaddr = interp->sh_addr - len;
2238 ph->p_paddr = ph->p_vaddr;
2239 ph->p_filesz = ph->p_memsz = len;
2240 ph->p_flags = PF_R | PF_X;
2241 ph->p_align = 4; /* interp->sh_addralign; */
2242 ph++;
2243 }
2244
2245 ph->p_type = PT_INTERP;
2246 ph->p_offset = interp->sh_offset;
2247 ph->p_vaddr = interp->sh_addr;
2248 ph->p_paddr = ph->p_vaddr;
2249 ph->p_filesz = interp->sh_size;
2250 ph->p_memsz = interp->sh_size;
2251 ph->p_flags = PF_R;
2252 ph->p_align = interp->sh_addralign;
2253 }
2254
2255 /* if dynamic section, then add corresponding program header */
2256 if (dynamic) {
2257 ph = &phdr[phnum - 1];
2258
2259 ph->p_type = PT_DYNAMIC;
2260 ph->p_offset = dynamic->sh_offset;
2261 ph->p_vaddr = dynamic->sh_addr;
2262 ph->p_paddr = ph->p_vaddr;
2263 ph->p_filesz = dynamic->sh_size;
2264 ph->p_memsz = dynamic->sh_size;
2265 ph->p_flags = PF_R | PF_W;
2266 ph->p_align = dynamic->sh_addralign;
2267 }
2268 }
2269
2270 /* Fill the dynamic section with tags describing the address and size of
2271 sections */
2272 static void fill_dynamic(TCCState *s1, struct dyn_inf *dyninf)
2273 {
2274 Section *dynamic;
2275
2276 dynamic = dyninf->dynamic;
2277
2278 /* put dynamic section entries */
2279 dynamic->data_offset = dyninf->dyn_rel_off;
2280 put_dt(dynamic, DT_HASH, s1->dynsym->hash->sh_addr);
2281 put_dt(dynamic, DT_STRTAB, dyninf->dynstr->sh_addr);
2282 put_dt(dynamic, DT_SYMTAB, s1->dynsym->sh_addr);
2283 put_dt(dynamic, DT_STRSZ, dyninf->dynstr->data_offset);
2284 put_dt(dynamic, DT_SYMENT, sizeof(ElfW(Sym)));
2285 #if defined(TCC_TARGET_ARM64) || defined(TCC_TARGET_X86_64)
2286 put_dt(dynamic, DT_RELA, dyninf->rel_addr);
2287 put_dt(dynamic, DT_RELASZ, dyninf->rel_size);
2288 put_dt(dynamic, DT_RELAENT, sizeof(ElfW_Rel));
2289 #else
2290 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2291 put_dt(dynamic, DT_PLTGOT, s1->got->sh_addr);
2292 put_dt(dynamic, DT_PLTRELSZ, dyninf->rel_size);
2293 put_dt(dynamic, DT_JMPREL, dyninf->rel_addr);
2294 put_dt(dynamic, DT_PLTREL, DT_REL);
2295 put_dt(dynamic, DT_REL, dyninf->bss_addr);
2296 put_dt(dynamic, DT_RELSZ, dyninf->bss_size);
2297 #else
2298 put_dt(dynamic, DT_REL, dyninf->rel_addr);
2299 put_dt(dynamic, DT_RELSZ, dyninf->rel_size);
2300 put_dt(dynamic, DT_RELENT, sizeof(ElfW_Rel));
2301 #endif
2302 #endif
2303 if (s1->do_debug)
2304 put_dt(dynamic, DT_DEBUG, 0);
2305 put_dt(dynamic, DT_NULL, 0);
2306 }
2307
2308 /* Relocate remaining sections and symbols (that is those not related to
2309 dynamic linking) */
2310 static int final_sections_reloc(TCCState *s1)
2311 {
2312 int i;
2313 Section *s;
2314
2315 relocate_syms(s1, 0);
2316
2317 if (s1->nb_errors != 0)
2318 return -1;
2319
2320 /* relocate sections */
2321 /* XXX: ignore sections with allocated relocations ? */
2322 for(i = 1; i < s1->nb_sections; i++) {
2323 s = s1->sections[i];
2324 #ifdef TCC_TARGET_I386
2325 if (s->reloc && s != s1->got && (s->sh_flags & SHF_ALLOC)) //gr
2326 /* On X86 gdb 7.3 works in any case but gdb 6.6 will crash if SHF_ALLOC
2327 checking is removed */
2328 #else
2329 if (s->reloc && s != s1->got)
2330 /* On X86_64 gdb 7.3 will crash if SHF_ALLOC checking is present */
2331 #endif
2332 relocate_section(s1, s);
2333 }
2334
2335 /* relocate relocation entries if the relocation tables are
2336 allocated in the executable */
2337 for(i = 1; i < s1->nb_sections; i++) {
2338 s = s1->sections[i];
2339 if ((s->sh_flags & SHF_ALLOC) &&
2340 s->sh_type == SHT_RELX) {
2341 relocate_rel(s1, s);
2342 }
2343 }
2344 return 0;
2345 }
2346
2347 /* Create an ELF file on disk.
2348 This function handle ELF specific layout requirements */
2349 static void tcc_output_elf(TCCState *s1, FILE *f, int phnum, ElfW(Phdr) *phdr,
2350 int file_offset, int *sec_order)
2351 {
2352 int i, shnum, offset, size, file_type;
2353 Section *s;
2354 ElfW(Ehdr) ehdr;
2355 ElfW(Shdr) shdr, *sh;
2356
2357 file_type = s1->output_type;
2358 shnum = s1->nb_sections;
2359
2360 memset(&ehdr, 0, sizeof(ehdr));
2361
2362 if (phnum > 0) {
2363 ehdr.e_phentsize = sizeof(ElfW(Phdr));
2364 ehdr.e_phnum = phnum;
2365 ehdr.e_phoff = sizeof(ElfW(Ehdr));
2366 }
2367
2368 /* align to 4 */
2369 file_offset = (file_offset + 3) & -4;
2370
2371 /* fill header */
2372 ehdr.e_ident[0] = ELFMAG0;
2373 ehdr.e_ident[1] = ELFMAG1;
2374 ehdr.e_ident[2] = ELFMAG2;
2375 ehdr.e_ident[3] = ELFMAG3;
2376 ehdr.e_ident[4] = ELFCLASSW;
2377 ehdr.e_ident[5] = ELFDATA2LSB;
2378 ehdr.e_ident[6] = EV_CURRENT;
2379 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2380 ehdr.e_ident[EI_OSABI] = ELFOSABI_FREEBSD;
2381 #endif
2382 #ifdef TCC_TARGET_ARM
2383 #ifdef TCC_ARM_EABI
2384 ehdr.e_ident[EI_OSABI] = 0;
2385 ehdr.e_flags = EF_ARM_EABI_VER4;
2386 if (file_type == TCC_OUTPUT_EXE || file_type == TCC_OUTPUT_DLL)
2387 ehdr.e_flags |= EF_ARM_HASENTRY;
2388 if (s1->float_abi == ARM_HARD_FLOAT)
2389 ehdr.e_flags |= EF_ARM_VFP_FLOAT;
2390 else
2391 ehdr.e_flags |= EF_ARM_SOFT_FLOAT;
2392 #else
2393 ehdr.e_ident[EI_OSABI] = ELFOSABI_ARM;
2394 #endif
2395 #endif
2396 switch(file_type) {
2397 default:
2398 case TCC_OUTPUT_EXE:
2399 ehdr.e_type = ET_EXEC;
2400 ehdr.e_entry = get_elf_sym_addr(s1, "_start", 1);
2401 break;
2402 case TCC_OUTPUT_DLL:
2403 ehdr.e_type = ET_DYN;
2404 ehdr.e_entry = text_section->sh_addr; /* XXX: is it correct ? */
2405 break;
2406 case TCC_OUTPUT_OBJ:
2407 ehdr.e_type = ET_REL;
2408 break;
2409 }
2410 ehdr.e_machine = EM_TCC_TARGET;
2411 ehdr.e_version = EV_CURRENT;
2412 ehdr.e_shoff = file_offset;
2413 ehdr.e_ehsize = sizeof(ElfW(Ehdr));
2414 ehdr.e_shentsize = sizeof(ElfW(Shdr));
2415 ehdr.e_shnum = shnum;
2416 ehdr.e_shstrndx = shnum - 1;
2417
2418 fwrite(&ehdr, 1, sizeof(ElfW(Ehdr)), f);
2419 fwrite(phdr, 1, phnum * sizeof(ElfW(Phdr)), f);
2420 offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr));
2421
2422 sort_syms(s1, symtab_section);
2423 for(i = 1; i < s1->nb_sections; i++) {
2424 s = s1->sections[sec_order[i]];
2425 if (s->sh_type != SHT_NOBITS) {
2426 if (s->sh_type == SHT_DYNSYM)
2427 patch_dynsym_undef(s1, s);
2428 while (offset < s->sh_offset) {
2429 fputc(0, f);
2430 offset++;
2431 }
2432 size = s->sh_size;
2433 if (size)
2434 fwrite(s->data, 1, size, f);
2435 offset += size;
2436 }
2437 }
2438
2439 /* output section headers */
2440 while (offset < ehdr.e_shoff) {
2441 fputc(0, f);
2442 offset++;
2443 }
2444
2445 for(i = 0; i < s1->nb_sections; i++) {
2446 sh = &shdr;
2447 memset(sh, 0, sizeof(ElfW(Shdr)));
2448 s = s1->sections[i];
2449 if (s) {
2450 sh->sh_name = s->sh_name;
2451 sh->sh_type = s->sh_type;
2452 sh->sh_flags = s->sh_flags;
2453 sh->sh_entsize = s->sh_entsize;
2454 sh->sh_info = s->sh_info;
2455 if (s->link)
2456 sh->sh_link = s->link->sh_num;
2457 sh->sh_addralign = s->sh_addralign;
2458 sh->sh_addr = s->sh_addr;
2459 sh->sh_offset = s->sh_offset;
2460 sh->sh_size = s->sh_size;
2461 }
2462 fwrite(sh, 1, sizeof(ElfW(Shdr)), f);
2463 }
2464 }
2465
2466 /* Write an elf, coff or "binary" file */
2467 static int tcc_write_elf_file(TCCState *s1, const char *filename, int phnum,
2468 ElfW(Phdr) *phdr, int file_offset, int *sec_order)
2469 {
2470 int fd, mode, file_type;
2471 FILE *f;
2472
2473 file_type = s1->output_type;
2474 if (file_type == TCC_OUTPUT_OBJ)
2475 mode = 0666;
2476 else
2477 mode = 0777;
2478 unlink(filename);
2479 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, mode);
2480 if (fd < 0) {
2481 tcc_error_noabort("could not write '%s'", filename);
2482 return -1;
2483 }
2484 f = fdopen(fd, "wb");
2485 if (s1->verbose)
2486 printf("<- %s\n", filename);
2487
2488 #ifdef TCC_TARGET_COFF
2489 if (s1->output_format == TCC_OUTPUT_FORMAT_COFF)
2490 tcc_output_coff(s1, f);
2491 else
2492 #endif
2493 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF)
2494 tcc_output_elf(s1, f, phnum, phdr, file_offset, sec_order);
2495 else
2496 tcc_output_binary(s1, f, sec_order);
2497 fclose(f);
2498
2499 return 0;
2500 }
2501
2502 /* Output an elf, coff or binary file */
2503 /* XXX: suppress unneeded sections */
2504 static int elf_output_file(TCCState *s1, const char *filename)
2505 {
2506 int i, ret, phnum, shnum, file_type, file_offset, *sec_order;
2507 struct dyn_inf dyninf;
2508 ElfW(Phdr) *phdr;
2509 ElfW(Sym) *sym;
2510 Section *strsec, *interp, *dynamic, *dynstr;
2511
2512 file_type = s1->output_type;
2513 s1->nb_errors = 0;
2514
2515 /* if linking, also link in runtime libraries (libc, libgcc, etc.) */
2516 if (file_type != TCC_OUTPUT_OBJ) {
2517 tcc_add_runtime(s1);
2518 }
2519
2520 phdr = NULL;
2521 sec_order = NULL;
2522 interp = dynamic = dynstr = NULL; /* avoid warning */
2523 dyninf.dyn_rel_off = 0; /* avoid warning */
2524
2525 if (file_type != TCC_OUTPUT_OBJ) {
2526 relocate_common_syms();
2527
2528 tcc_add_linker_symbols(s1);
2529
2530 if (!s1->static_link) {
2531 if (file_type == TCC_OUTPUT_EXE) {
2532 char *ptr;
2533 /* allow override the dynamic loader */
2534 const char *elfint = getenv("LD_SO");
2535 if (elfint == NULL)
2536 elfint = DEFAULT_ELFINTERP(s1);
2537 /* add interpreter section only if executable */
2538 interp = new_section(s1, ".interp", SHT_PROGBITS, SHF_ALLOC);
2539 interp->sh_addralign = 1;
2540 ptr = section_ptr_add(interp, 1 + strlen(elfint));
2541 strcpy(ptr, elfint);
2542 }
2543
2544 /* add dynamic symbol table */
2545 s1->dynsym = new_symtab(s1, ".dynsym", SHT_DYNSYM, SHF_ALLOC,
2546 ".dynstr",
2547 ".hash", SHF_ALLOC);
2548 dynstr = s1->dynsym->link;
2549
2550 /* add dynamic section */
2551 dynamic = new_section(s1, ".dynamic", SHT_DYNAMIC,
2552 SHF_ALLOC | SHF_WRITE);
2553 dynamic->link = dynstr;
2554 dynamic->sh_entsize = sizeof(ElfW(Dyn));
2555
2556 build_got(s1);
2557
2558 if (file_type == TCC_OUTPUT_EXE) {
2559 bind_exe_dynsyms(s1);
2560
2561 if (s1->nb_errors) {
2562 ret = -1;
2563 goto the_end;
2564 }
2565
2566 bind_libs_dynsyms(s1);
2567 } else /* shared library case: simply export all global symbols */
2568 export_global_syms(s1);
2569
2570 build_got_entries(s1);
2571
2572 /* add a list of needed dlls */
2573 for(i = 0; i < s1->nb_loaded_dlls; i++) {
2574 DLLReference *dllref = s1->loaded_dlls[i];
2575 if (dllref->level == 0)
2576 put_dt(dynamic, DT_NEEDED, put_elf_str(dynstr, dllref->name));
2577 }
2578
2579 if (s1->rpath)
2580 put_dt(dynamic, DT_RPATH, put_elf_str(dynstr, s1->rpath));
2581
2582 /* XXX: currently, since we do not handle PIC code, we
2583 must relocate the readonly segments */
2584 if (file_type == TCC_OUTPUT_DLL) {
2585 if (s1->soname)
2586 put_dt(dynamic, DT_SONAME, put_elf_str(dynstr, s1->soname));
2587 put_dt(dynamic, DT_TEXTREL, 0);
2588 }
2589
2590 if (s1->symbolic)
2591 put_dt(dynamic, DT_SYMBOLIC, 0);
2592
2593 /* add necessary space for other entries */
2594 dyninf.dyn_rel_off = dynamic->data_offset;
2595 dynamic->data_offset += sizeof(ElfW(Dyn)) * EXTRA_RELITEMS;
2596 } else {
2597 /* still need to build got entries in case of static link */
2598 build_got_entries(s1);
2599 }
2600 }
2601
2602 /* we add a section for symbols */
2603 strsec = new_section(s1, ".shstrtab", SHT_STRTAB, 0);
2604 put_elf_str(strsec, "");
2605
2606 /* compute number of sections */
2607 shnum = s1->nb_sections;
2608
2609 /* this array is used to reorder sections in the output file */
2610 sec_order = tcc_malloc(sizeof(int) * shnum);
2611 sec_order[0] = 0;
2612
2613 /* compute number of program headers */
2614 switch(file_type) {
2615 default:
2616 case TCC_OUTPUT_OBJ:
2617 phnum = 0;
2618 break;
2619 case TCC_OUTPUT_EXE:
2620 if (!s1->static_link)
2621 phnum = 4 + HAVE_PHDR;
2622 else
2623 phnum = 2;
2624 break;
2625 case TCC_OUTPUT_DLL:
2626 phnum = 3;
2627 break;
2628 }
2629
2630 /* Allocate strings for section names */
2631 alloc_sec_names(s1, file_type, strsec);
2632
2633 /* allocate program segment headers */
2634 phdr = tcc_mallocz(phnum * sizeof(ElfW(Phdr)));
2635
2636 /* compute section to program header mapping */
2637 file_offset = layout_sections(s1, phdr, phnum, interp, strsec, &dyninf,
2638 sec_order);
2639
2640 /* Fill remaining program header and finalize relocation related to dynamic
2641 linking. */
2642 if (phnum > 0) {
2643 fill_unloadable_phdr(phdr, phnum, interp, dynamic);
2644 if (dynamic) {
2645 dyninf.dynamic = dynamic;
2646 dyninf.dynstr = dynstr;
2647
2648 fill_dynamic(s1, &dyninf);
2649
2650 /* put in GOT the dynamic section address and relocate PLT */
2651 write32le(s1->got->data, dynamic->sh_addr);
2652 if (file_type == TCC_OUTPUT_EXE
2653 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
2654 || file_type == TCC_OUTPUT_DLL
2655 #endif
2656 )
2657 relocate_plt(s1);
2658
2659 /* relocate symbols in .dynsym now that final addresses are known */
2660 for_each_elem(s1->dynsym, 1, sym, ElfW(Sym)) {
2661 if (sym->st_shndx == SHN_UNDEF) {
2662 /* relocate to PLT if symbol corresponds to a PLT entry,
2663 but not if it's a weak symbol */
2664 if (ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
2665 sym->st_value = 0;
2666 else if (sym->st_value)
2667 sym->st_value += s1->plt->sh_addr;
2668 } else if (sym->st_shndx < SHN_LORESERVE) {
2669 /* do symbol relocation */
2670 sym->st_value += s1->sections[sym->st_shndx]->sh_addr;
2671 }
2672 }
2673 }
2674 }
2675
2676 /* if building executable or DLL, then relocate each section
2677 except the GOT which is already relocated */
2678 if (file_type != TCC_OUTPUT_OBJ) {
2679 ret = final_sections_reloc(s1);
2680 if (ret)
2681 goto the_end;
2682 }
2683
2684 /* Perform relocation to GOT or PLT entries */
2685 if (file_type == TCC_OUTPUT_EXE && s1->static_link)
2686 fill_got(s1);
2687
2688 /* Create the ELF file with name 'filename' */
2689 ret = tcc_write_elf_file(s1, filename, phnum, phdr, file_offset, sec_order);
2690 the_end:
2691 tcc_free(s1->symtab_to_dynsym);
2692 tcc_free(sec_order);
2693 tcc_free(phdr);
2694 tcc_free(s1->sym_attrs);
2695 s1->sym_attrs = NULL;
2696 return ret;
2697 }
2698
2699 LIBTCCAPI int tcc_output_file(TCCState *s, const char *filename)
2700 {
2701 int ret;
2702 #ifdef TCC_TARGET_PE
2703 if (s->output_type != TCC_OUTPUT_OBJ) {
2704 ret = pe_output_file(s, filename);
2705 } else
2706 #endif
2707 ret = elf_output_file(s, filename);
2708 return ret;
2709 }
2710
2711 static void *load_data(int fd, unsigned long file_offset, unsigned long size)
2712 {
2713 void *data;
2714
2715 data = tcc_malloc(size);
2716 lseek(fd, file_offset, SEEK_SET);
2717 read(fd, data, size);
2718 return data;
2719 }
2720
2721 typedef struct SectionMergeInfo {
2722 Section *s; /* corresponding existing section */
2723 unsigned long offset; /* offset of the new section in the existing section */
2724 uint8_t new_section; /* true if section 's' was added */
2725 uint8_t link_once; /* true if link once section */
2726 } SectionMergeInfo;
2727
2728 /* load an object file and merge it with current files */
2729 /* XXX: handle correctly stab (debug) info */
2730 ST_FUNC int tcc_load_object_file(TCCState *s1,
2731 int fd, unsigned long file_offset)
2732 {
2733 ElfW(Ehdr) ehdr;
2734 ElfW(Shdr) *shdr, *sh;
2735 int size, i, j, offset, offseti, nb_syms, sym_index, ret;
2736 unsigned char *strsec, *strtab;
2737 int *old_to_new_syms;
2738 char *sh_name, *name;
2739 SectionMergeInfo *sm_table, *sm;
2740 ElfW(Sym) *sym, *symtab;
2741 ElfW_Rel *rel;
2742 Section *s;
2743
2744 int stab_index;
2745 int stabstr_index;
2746
2747 stab_index = stabstr_index = 0;
2748
2749 if (read(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr))
2750 goto fail1;
2751 if (ehdr.e_ident[0] != ELFMAG0 ||
2752 ehdr.e_ident[1] != ELFMAG1 ||
2753 ehdr.e_ident[2] != ELFMAG2 ||
2754 ehdr.e_ident[3] != ELFMAG3)
2755 goto fail1;
2756 /* test if object file */
2757 if (ehdr.e_type != ET_REL)
2758 goto fail1;
2759 /* test CPU specific stuff */
2760 if (ehdr.e_ident[5] != ELFDATA2LSB ||
2761 ehdr.e_machine != EM_TCC_TARGET) {
2762 fail1:
2763 tcc_error_noabort("invalid object file");
2764 return -1;
2765 }
2766 /* read sections */
2767 shdr = load_data(fd, file_offset + ehdr.e_shoff,
2768 sizeof(ElfW(Shdr)) * ehdr.e_shnum);
2769 sm_table = tcc_mallocz(sizeof(SectionMergeInfo) * ehdr.e_shnum);
2770
2771 /* load section names */
2772 sh = &shdr[ehdr.e_shstrndx];
2773 strsec = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2774
2775 /* load symtab and strtab */
2776 old_to_new_syms = NULL;
2777 symtab = NULL;
2778 strtab = NULL;
2779 nb_syms = 0;
2780 for(i = 1; i < ehdr.e_shnum; i++) {
2781 sh = &shdr[i];
2782 if (sh->sh_type == SHT_SYMTAB) {
2783 if (symtab) {
2784 tcc_error_noabort("object must contain only one symtab");
2785 fail:
2786 ret = -1;
2787 goto the_end;
2788 }
2789 nb_syms = sh->sh_size / sizeof(ElfW(Sym));
2790 symtab = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2791 sm_table[i].s = symtab_section;
2792
2793 /* now load strtab */
2794 sh = &shdr[sh->sh_link];
2795 strtab = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2796 }
2797 }
2798
2799 /* now examine each section and try to merge its content with the
2800 ones in memory */
2801 for(i = 1; i < ehdr.e_shnum; i++) {
2802 /* no need to examine section name strtab */
2803 if (i == ehdr.e_shstrndx)
2804 continue;
2805 sh = &shdr[i];
2806 sh_name = (char *) strsec + sh->sh_name;
2807 /* ignore sections types we do not handle */
2808 if (sh->sh_type != SHT_PROGBITS &&
2809 sh->sh_type != SHT_RELX &&
2810 #ifdef TCC_ARM_EABI
2811 sh->sh_type != SHT_ARM_EXIDX &&
2812 #endif
2813 sh->sh_type != SHT_NOBITS &&
2814 sh->sh_type != SHT_PREINIT_ARRAY &&
2815 sh->sh_type != SHT_INIT_ARRAY &&
2816 sh->sh_type != SHT_FINI_ARRAY &&
2817 strcmp(sh_name, ".stabstr")
2818 )
2819 continue;
2820 if (sh->sh_addralign < 1)
2821 sh->sh_addralign = 1;
2822 /* find corresponding section, if any */
2823 for(j = 1; j < s1->nb_sections;j++) {
2824 s = s1->sections[j];
2825 if (!strcmp(s->name, sh_name)) {
2826 if (!strncmp(sh_name, ".gnu.linkonce",
2827 sizeof(".gnu.linkonce") - 1)) {
2828 /* if a 'linkonce' section is already present, we
2829 do not add it again. It is a little tricky as
2830 symbols can still be defined in
2831 it. */
2832 sm_table[i].link_once = 1;
2833 goto next;
2834 } else {
2835 goto found;
2836 }
2837 }
2838 }
2839 /* not found: create new section */
2840 s = new_section(s1, sh_name, sh->sh_type, sh->sh_flags);
2841 /* take as much info as possible from the section. sh_link and
2842 sh_info will be updated later */
2843 s->sh_addralign = sh->sh_addralign;
2844 s->sh_entsize = sh->sh_entsize;
2845 sm_table[i].new_section = 1;
2846 found:
2847 if (sh->sh_type != s->sh_type) {
2848 tcc_error_noabort("invalid section type");
2849 goto fail;
2850 }
2851
2852 /* align start of section */
2853 offset = s->data_offset;
2854
2855 if (0 == strcmp(sh_name, ".stab")) {
2856 stab_index = i;
2857 goto no_align;
2858 }
2859 if (0 == strcmp(sh_name, ".stabstr")) {
2860 stabstr_index = i;
2861 goto no_align;
2862 }
2863
2864 size = sh->sh_addralign - 1;
2865 offset = (offset + size) & ~size;
2866 if (sh->sh_addralign > s->sh_addralign)
2867 s->sh_addralign = sh->sh_addralign;
2868 s->data_offset = offset;
2869 no_align:
2870 sm_table[i].offset = offset;
2871 sm_table[i].s = s;
2872 /* concatenate sections */
2873 size = sh->sh_size;
2874 if (sh->sh_type != SHT_NOBITS) {
2875 unsigned char *ptr;
2876 lseek(fd, file_offset + sh->sh_offset, SEEK_SET);
2877 ptr = section_ptr_add(s, size);
2878 read(fd, ptr, size);
2879 } else {
2880 s->data_offset += size;
2881 }
2882 next: ;
2883 }
2884
2885 /* gr relocate stab strings */
2886 if (stab_index && stabstr_index) {
2887 Stab_Sym *a, *b;
2888 unsigned o;
2889 s = sm_table[stab_index].s;
2890 a = (Stab_Sym *)(s->data + sm_table[stab_index].offset);
2891 b = (Stab_Sym *)(s->data + s->data_offset);
2892 o = sm_table[stabstr_index].offset;
2893 while (a < b)
2894 a->n_strx += o, a++;
2895 }
2896
2897 /* second short pass to update sh_link and sh_info fields of new
2898 sections */
2899 for(i = 1; i < ehdr.e_shnum; i++) {
2900 s = sm_table[i].s;
2901 if (!s || !sm_table[i].new_section)
2902 continue;
2903 sh = &shdr[i];
2904 if (sh->sh_link > 0)
2905 s->link = sm_table[sh->sh_link].s;
2906 if (sh->sh_type == SHT_RELX) {
2907 s->sh_info = sm_table[sh->sh_info].s->sh_num;
2908 /* update backward link */
2909 s1->sections[s->sh_info]->reloc = s;
2910 }
2911 }
2912 sm = sm_table;
2913
2914 /* resolve symbols */
2915 old_to_new_syms = tcc_mallocz(nb_syms * sizeof(int));
2916
2917 sym = symtab + 1;
2918 for(i = 1; i < nb_syms; i++, sym++) {
2919 if (sym->st_shndx != SHN_UNDEF &&
2920 sym->st_shndx < SHN_LORESERVE) {
2921 sm = &sm_table[sym->st_shndx];
2922 if (sm->link_once) {
2923 /* if a symbol is in a link once section, we use the
2924 already defined symbol. It is very important to get
2925 correct relocations */
2926 if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
2927 name = (char *) strtab + sym->st_name;
2928 sym_index = find_elf_sym(symtab_section, name);
2929 if (sym_index)
2930 old_to_new_syms[i] = sym_index;
2931 }
2932 continue;
2933 }
2934 /* if no corresponding section added, no need to add symbol */
2935 if (!sm->s)
2936 continue;
2937 /* convert section number */
2938 sym->st_shndx = sm->s->sh_num;
2939 /* offset value */
2940 sym->st_value += sm->offset;
2941 }
2942 /* add symbol */
2943 name = (char *) strtab + sym->st_name;
2944 sym_index = add_elf_sym(symtab_section, sym->st_value, sym->st_size,
2945 sym->st_info, sym->st_other,
2946 sym->st_shndx, name);
2947 old_to_new_syms[i] = sym_index;
2948 }
2949
2950 /* third pass to patch relocation entries */
2951 for(i = 1; i < ehdr.e_shnum; i++) {
2952 s = sm_table[i].s;
2953 if (!s)
2954 continue;
2955 sh = &shdr[i];
2956 offset = sm_table[i].offset;
2957 switch(s->sh_type) {
2958 case SHT_RELX:
2959 /* take relocation offset information */
2960 offseti = sm_table[sh->sh_info].offset;
2961 for_each_elem(s, (offset / sizeof(*rel)), rel, ElfW_Rel) {
2962 int type;
2963 unsigned sym_index;
2964 /* convert symbol index */
2965 type = ELFW(R_TYPE)(rel->r_info);
2966 sym_index = ELFW(R_SYM)(rel->r_info);
2967 /* NOTE: only one symtab assumed */
2968 if (sym_index >= nb_syms)
2969 goto invalid_reloc;
2970 sym_index = old_to_new_syms[sym_index];
2971 /* ignore link_once in rel section. */
2972 if (!sym_index && !sm->link_once
2973 #ifdef TCC_TARGET_ARM
2974 && type != R_ARM_V4BX
2975 #endif
2976 ) {
2977 invalid_reloc:
2978 tcc_error_noabort("Invalid relocation entry [%2d] '%s' @ %.8x",
2979 i, strsec + sh->sh_name, rel->r_offset);
2980 goto fail;
2981 }
2982 rel->r_info = ELFW(R_INFO)(sym_index, type);
2983 /* offset the relocation offset */
2984 rel->r_offset += offseti;
2985 #ifdef TCC_TARGET_ARM
2986 /* Jumps and branches from a Thumb code to a PLT entry need
2987 special handling since PLT entries are ARM code.
2988 Unconditional bl instructions referencing PLT entries are
2989 handled by converting these instructions into blx
2990 instructions. Other case of instructions referencing a PLT
2991 entry require to add a Thumb stub before the PLT entry to
2992 switch to ARM mode. We set bit plt_thumb_stub of the
2993 attribute of a symbol to indicate such a case. */
2994 if (type == R_ARM_THM_JUMP24)
2995 alloc_sym_attr(s1, sym_index)->plt_thumb_stub = 1;
2996 #endif
2997 }
2998 break;
2999 default:
3000 break;
3001 }
3002 }
3003
3004 ret = 0;
3005 the_end:
3006 tcc_free(symtab);
3007 tcc_free(strtab);
3008 tcc_free(old_to_new_syms);
3009 tcc_free(sm_table);
3010 tcc_free(strsec);
3011 tcc_free(shdr);
3012 return ret;
3013 }
3014
3015 typedef struct ArchiveHeader {
3016 char ar_name[16]; /* name of this member */
3017 char ar_date[12]; /* file mtime */
3018 char ar_uid[6]; /* owner uid; printed as decimal */
3019 char ar_gid[6]; /* owner gid; printed as decimal */
3020 char ar_mode[8]; /* file mode, printed as octal */
3021 char ar_size[10]; /* file size, printed as decimal */
3022 char ar_fmag[2]; /* should contain ARFMAG */
3023 } ArchiveHeader;
3024
3025 static int get_be32(const uint8_t *b)
3026 {
3027 return b[3] | (b[2] << 8) | (b[1] << 16) | (b[0] << 24);
3028 }
3029
3030 /* load only the objects which resolve undefined symbols */
3031 static int tcc_load_alacarte(TCCState *s1, int fd, int size)
3032 {
3033 int i, bound, nsyms, sym_index, off, ret;
3034 uint8_t *data;
3035 const char *ar_names, *p;
3036 const uint8_t *ar_index;
3037 ElfW(Sym) *sym;
3038
3039 data = tcc_malloc(size);
3040 if (read(fd, data, size) != size)
3041 goto fail;
3042 nsyms = get_be32(data);
3043 ar_index = data + 4;
3044 ar_names = (char *) ar_index + nsyms * 4;
3045
3046 do {
3047 bound = 0;
3048 for(p = ar_names, i = 0; i < nsyms; i++, p += strlen(p)+1) {
3049 sym_index = find_elf_sym(symtab_section, p);
3050 if(sym_index) {
3051 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
3052 if(sym->st_shndx == SHN_UNDEF) {
3053 off = get_be32(ar_index + i * 4) + sizeof(ArchiveHeader);
3054 ++bound;
3055 lseek(fd, off, SEEK_SET);
3056 if(tcc_load_object_file(s1, fd, off) < 0) {
3057 fail:
3058 ret = -1;
3059 goto the_end;
3060 }
3061 }
3062 }
3063 }
3064 } while(bound);
3065 ret = 0;
3066 the_end:
3067 tcc_free(data);
3068 return ret;
3069 }
3070
3071 /* load a '.a' file */
3072 ST_FUNC int tcc_load_archive(TCCState *s1, int fd)
3073 {
3074 ArchiveHeader hdr;
3075 char ar_size[11];
3076 char ar_name[17];
3077 char magic[8];
3078 int size, len, i;
3079 unsigned long file_offset;
3080
3081 /* skip magic which was already checked */
3082 read(fd, magic, sizeof(magic));
3083
3084 for(;;) {
3085 len = read(fd, &hdr, sizeof(hdr));
3086 if (len == 0)
3087 break;
3088 if (len != sizeof(hdr)) {
3089 tcc_error_noabort("invalid archive");
3090 return -1;
3091 }
3092 memcpy(ar_size, hdr.ar_size, sizeof(hdr.ar_size));
3093 ar_size[sizeof(hdr.ar_size)] = '\0';
3094 size = strtol(ar_size, NULL, 0);
3095 memcpy(ar_name, hdr.ar_name, sizeof(hdr.ar_name));
3096 for(i = sizeof(hdr.ar_name) - 1; i >= 0; i--) {
3097 if (ar_name[i] != ' ')
3098 break;
3099 }
3100 ar_name[i + 1] = '\0';
3101 file_offset = lseek(fd, 0, SEEK_CUR);
3102 /* align to even */
3103 size = (size + 1) & ~1;
3104 if (!strcmp(ar_name, "/")) {
3105 /* coff symbol table : we handle it */
3106 if(s1->alacarte_link)
3107 return tcc_load_alacarte(s1, fd, size);
3108 } else if (!strcmp(ar_name, "//") ||
3109 !strcmp(ar_name, "__.SYMDEF") ||
3110 !strcmp(ar_name, "__.SYMDEF/") ||
3111 !strcmp(ar_name, "ARFILENAMES/")) {
3112 /* skip symbol table or archive names */
3113 } else {
3114 if (tcc_load_object_file(s1, fd, file_offset) < 0)
3115 return -1;
3116 }
3117 lseek(fd, file_offset + size, SEEK_SET);
3118 }
3119 return 0;
3120 }
3121
3122 #ifndef TCC_TARGET_PE
3123 /* load a DLL and all referenced DLLs. 'level = 0' means that the DLL
3124 is referenced by the user (so it should be added as DT_NEEDED in
3125 the generated ELF file) */
3126 ST_FUNC int tcc_load_dll(TCCState *s1, int fd, const char *filename, int level)
3127 {
3128 ElfW(Ehdr) ehdr;
3129 ElfW(Shdr) *shdr, *sh, *sh1;
3130 int i, j, nb_syms, nb_dts, sym_bind, ret;
3131 ElfW(Sym) *sym, *dynsym;
3132 ElfW(Dyn) *dt, *dynamic;
3133 unsigned char *dynstr;
3134 const char *name, *soname;
3135 DLLReference *dllref;
3136
3137 read(fd, &ehdr, sizeof(ehdr));
3138
3139 /* test CPU specific stuff */
3140 if (ehdr.e_ident[5] != ELFDATA2LSB ||
3141 ehdr.e_machine != EM_TCC_TARGET) {
3142 tcc_error_noabort("bad architecture");
3143 return -1;
3144 }
3145
3146 /* read sections */
3147 shdr = load_data(fd, ehdr.e_shoff, sizeof(ElfW(Shdr)) * ehdr.e_shnum);
3148
3149 /* load dynamic section and dynamic symbols */
3150 nb_syms = 0;
3151 nb_dts = 0;
3152 dynamic = NULL;
3153 dynsym = NULL; /* avoid warning */
3154 dynstr = NULL; /* avoid warning */
3155 for(i = 0, sh = shdr; i < ehdr.e_shnum; i++, sh++) {
3156 switch(sh->sh_type) {
3157 case SHT_DYNAMIC:
3158 nb_dts = sh->sh_size / sizeof(ElfW(Dyn));
3159 dynamic = load_data(fd, sh->sh_offset, sh->sh_size);
3160 break;
3161 case SHT_DYNSYM:
3162 nb_syms = sh->sh_size / sizeof(ElfW(Sym));
3163 dynsym = load_data(fd, sh->sh_offset, sh->sh_size);
3164 sh1 = &shdr[sh->sh_link];
3165 dynstr = load_data(fd, sh1->sh_offset, sh1->sh_size);
3166 break;
3167 default:
3168 break;
3169 }
3170 }
3171
3172 /* compute the real library name */
3173 soname = tcc_basename(filename);
3174
3175 for(i = 0, dt = dynamic; i < nb_dts; i++, dt++) {
3176 if (dt->d_tag == DT_SONAME) {
3177 soname = (char *) dynstr + dt->d_un.d_val;
3178 }
3179 }
3180
3181 /* if the dll is already loaded, do not load it */
3182 for(i = 0; i < s1->nb_loaded_dlls; i++) {
3183 dllref = s1->loaded_dlls[i];
3184 if (!strcmp(soname, dllref->name)) {
3185 /* but update level if needed */
3186 if (level < dllref->level)
3187 dllref->level = level;
3188 ret = 0;
3189 goto the_end;
3190 }
3191 }
3192
3193 /* add the dll and its level */
3194 dllref = tcc_mallocz(sizeof(DLLReference) + strlen(soname));
3195 dllref->level = level;
3196 strcpy(dllref->name, soname);
3197 dynarray_add((void ***)&s1->loaded_dlls, &s1->nb_loaded_dlls, dllref);
3198
3199 /* add dynamic symbols in dynsym_section */
3200 for(i = 1, sym = dynsym + 1; i < nb_syms; i++, sym++) {
3201 sym_bind = ELFW(ST_BIND)(sym->st_info);
3202 if (sym_bind == STB_LOCAL)
3203 continue;
3204 name = (char *) dynstr + sym->st_name;
3205 add_elf_sym(s1->dynsymtab_section, sym->st_value, sym->st_size,
3206 sym->st_info, sym->st_other, sym->st_shndx, name);
3207 }
3208
3209 /* load all referenced DLLs */
3210 for(i = 0, dt = dynamic; i < nb_dts; i++, dt++) {
3211 switch(dt->d_tag) {
3212 case DT_NEEDED:
3213 name = (char *) dynstr + dt->d_un.d_val;
3214 for(j = 0; j < s1->nb_loaded_dlls; j++) {
3215 dllref = s1->loaded_dlls[j];
3216 if (!strcmp(name, dllref->name))
3217 goto already_loaded;
3218 }
3219 if (tcc_add_dll(s1, name, AFF_REFERENCED_DLL) < 0) {
3220 tcc_error_noabort("referenced dll '%s' not found", name);
3221 ret = -1;
3222 goto the_end;
3223 }
3224 already_loaded:
3225 break;
3226 }
3227 }
3228 ret = 0;
3229 the_end:
3230 tcc_free(dynstr);
3231 tcc_free(dynsym);
3232 tcc_free(dynamic);
3233 tcc_free(shdr);
3234 return ret;
3235 }
3236
3237 #define LD_TOK_NAME 256
3238 #define LD_TOK_EOF (-1)
3239
3240 /* return next ld script token */
3241 static int ld_next(TCCState *s1, char *name, int name_size)
3242 {
3243 int c;
3244 char *q;
3245
3246 redo:
3247 switch(ch) {
3248 case ' ':
3249 case '\t':
3250 case '\f':
3251 case '\v':
3252 case '\r':
3253 case '\n':
3254 inp();
3255 goto redo;
3256 case '/':
3257 minp();
3258 if (ch == '*') {
3259 file->buf_ptr = parse_comment(file->buf_ptr);
3260 ch = file->buf_ptr[0];
3261 goto redo;
3262 } else {
3263 q = name;
3264 *q++ = '/';
3265 goto parse_name;
3266 }
3267 break;
3268 case '\\':
3269 ch = handle_eob();
3270 if (ch != '\\')
3271 goto redo;
3272 /* fall through */
3273 /* case 'a' ... 'z': */
3274 case 'a':
3275 case 'b':
3276 case 'c':
3277 case 'd':
3278 case 'e':
3279 case 'f':
3280 case 'g':
3281 case 'h':
3282 case 'i':
3283 case 'j':
3284 case 'k':
3285 case 'l':
3286 case 'm':
3287 case 'n':
3288 case 'o':
3289 case 'p':
3290 case 'q':
3291 case 'r':
3292 case 's':
3293 case 't':
3294 case 'u':
3295 case 'v':
3296 case 'w':
3297 case 'x':
3298 case 'y':
3299 case 'z':
3300 /* case 'A' ... 'z': */
3301 case 'A':
3302 case 'B':
3303 case 'C':
3304 case 'D':
3305 case 'E':
3306 case 'F':
3307 case 'G':
3308 case 'H':
3309 case 'I':
3310 case 'J':
3311 case 'K':
3312 case 'L':
3313 case 'M':
3314 case 'N':
3315 case 'O':
3316 case 'P':
3317 case 'Q':
3318 case 'R':
3319 case 'S':
3320 case 'T':
3321 case 'U':
3322 case 'V':
3323 case 'W':
3324 case 'X':
3325 case 'Y':
3326 case 'Z':
3327 case '_':
3328 case '.':
3329 case '$':
3330 case '~':
3331 q = name;
3332 parse_name:
3333 for(;;) {
3334 if (!((ch >= 'a' && ch <= 'z') ||
3335 (ch >= 'A' && ch <= 'Z') ||
3336 (ch >= '0' && ch <= '9') ||
3337 strchr("/.-_+=$:\\,~", ch)))
3338 break;
3339 if ((q - name) < name_size - 1) {
3340 *q++ = ch;
3341 }
3342 minp();
3343 }
3344 *q = '\0';
3345 c = LD_TOK_NAME;
3346 break;
3347 case CH_EOF:
3348 c = LD_TOK_EOF;
3349 break;
3350 default:
3351 c = ch;
3352 inp();
3353 break;
3354 }
3355 return c;
3356 }
3357
3358 static int ld_add_file(TCCState *s1, const char filename[])
3359 {
3360 int ret;
3361
3362 ret = tcc_add_file_internal(s1, filename, AFF_TYPE_BIN);
3363 if (ret)
3364 ret = tcc_add_dll(s1, filename, 0);
3365 return ret;
3366 }
3367
3368 static inline int new_undef_syms(void)
3369 {
3370 int ret = 0;
3371 ret = new_undef_sym;
3372 new_undef_sym = 0;
3373 return ret;
3374 }
3375
3376 static int ld_add_file_list(TCCState *s1, const char *cmd, int as_needed)
3377 {
3378 char filename[1024], libname[1024];
3379 int t, group, nblibs = 0, ret = 0;
3380 char **libs = NULL;
3381
3382 group = !strcmp(cmd, "GROUP");
3383 if (!as_needed)
3384 new_undef_syms();
3385 t = ld_next(s1, filename, sizeof(filename));
3386 if (t != '(')
3387 expect("(");
3388 t = ld_next(s1, filename, sizeof(filename));
3389 for(;;) {
3390 libname[0] = '\0';
3391 if (t == LD_TOK_EOF) {
3392 tcc_error_noabort("unexpected end of file");
3393 ret = -1;
3394 goto lib_parse_error;
3395 } else if (t == ')') {
3396 break;
3397 } else if (t == '-') {
3398 t = ld_next(s1, filename, sizeof(filename));
3399 if ((t != LD_TOK_NAME) || (filename[0] != 'l')) {
3400 tcc_error_noabort("library name expected");
3401 ret = -1;
3402 goto lib_parse_error;
3403 }
3404 pstrcpy(libname, sizeof libname, &filename[1]);
3405 if (s1->static_link) {
3406 snprintf(filename, sizeof filename, "lib%s.a", libname);
3407 } else {
3408 snprintf(filename, sizeof filename, "lib%s.so", libname);
3409 }
3410 } else if (t != LD_TOK_NAME) {
3411 tcc_error_noabort("filename expected");
3412 ret = -1;
3413 goto lib_parse_error;
3414 }
3415 if (!strcmp(filename, "AS_NEEDED")) {
3416 ret = ld_add_file_list(s1, cmd, 1);
3417 if (ret)
3418 goto lib_parse_error;
3419 } else {
3420 /* TODO: Implement AS_NEEDED support. Ignore it for now */
3421 if (!as_needed) {
3422 ret = ld_add_file(s1, filename);
3423 if (ret)
3424 goto lib_parse_error;
3425 if (group) {
3426 /* Add the filename *and* the libname to avoid future conversions */
3427 dynarray_add((void ***) &libs, &nblibs, tcc_strdup(filename));
3428 if (libname[0] != '\0')
3429 dynarray_add((void ***) &libs, &nblibs, tcc_strdup(libname));
3430 }
3431 }
3432 }
3433 t = ld_next(s1, filename, sizeof(filename));
3434 if (t == ',') {
3435 t = ld_next(s1, filename, sizeof(filename));
3436 }
3437 }
3438 if (group && !as_needed) {
3439 while (new_undef_syms()) {
3440 int i;
3441
3442 for (i = 0; i < nblibs; i ++)
3443 ld_add_file(s1, libs[i]);
3444 }
3445 }
3446 lib_parse_error:
3447 dynarray_reset(&libs, &nblibs);
3448 return ret;
3449 }
3450
3451 /* interpret a subset of GNU ldscripts to handle the dummy libc.so
3452 files */
3453 ST_FUNC int tcc_load_ldscript(TCCState *s1)
3454 {
3455 char cmd[64];
3456 char filename[1024];
3457 int t, ret;
3458
3459 ch = handle_eob();
3460 for(;;) {
3461 t = ld_next(s1, cmd, sizeof(cmd));
3462 if (t == LD_TOK_EOF)
3463 return 0;
3464 else if (t != LD_TOK_NAME)
3465 return -1;
3466 if (!strcmp(cmd, "INPUT") ||
3467 !strcmp(cmd, "GROUP")) {
3468 ret = ld_add_file_list(s1, cmd, 0);
3469 if (ret)
3470 return ret;
3471 } else if (!strcmp(cmd, "OUTPUT_FORMAT") ||
3472 !strcmp(cmd, "TARGET")) {
3473 /* ignore some commands */
3474 t = ld_next(s1, cmd, sizeof(cmd));
3475 if (t != '(')
3476 expect("(");
3477 for(;;) {
3478 t = ld_next(s1, filename, sizeof(filename));
3479 if (t == LD_TOK_EOF) {
3480 tcc_error_noabort("unexpected end of file");
3481 return -1;
3482 } else if (t == ')') {
3483 break;
3484 }
3485 }
3486 } else {
3487 return -1;
3488 }
3489 }
3490 return 0;
3491 }
3492 #endif /* !TCC_TARGET_PE */
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