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x86-64: Add support for new psABI relocations
[tinycc.git] / tccelf.c
blobfdb549a542c39b34ea4095eaa5aecec1edd2c2f3
1 /*
2 * ELF file handling for TCC
3 *
4 * Copyright (c) 2001-2004 Fabrice Bellard
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 */
20
21 #include "tcc.h"
22
23 /* Define this to get some debug output during relocation processing. */
24 #undef DEBUG_RELOC
25
26 /* XXX: avoid static variable */
27 static int new_undef_sym = 0; /* Is there a new undefined sym since last new_undef_sym() */
28
29 ST_FUNC int put_elf_str(Section *s, const char *sym)
30 {
31 int offset, len;
32 char *ptr;
33
34 len = strlen(sym) + 1;
35 offset = s->data_offset;
36 ptr = section_ptr_add(s, len);
37 memcpy(ptr, sym, len);
38 return offset;
39 }
40
41 /* elf symbol hashing function */
42 static unsigned long elf_hash(const unsigned char *name)
43 {
44 unsigned long h = 0, g;
45
46 while (*name) {
47 h = (h << 4) + *name++;
48 g = h & 0xf0000000;
49 if (g)
50 h ^= g >> 24;
51 h &= ~g;
52 }
53 return h;
54 }
55
56 /* rebuild hash table of section s */
57 /* NOTE: we do factorize the hash table code to go faster */
58 static void rebuild_hash(Section *s, unsigned int nb_buckets)
59 {
60 ElfW(Sym) *sym;
61 int *ptr, *hash, nb_syms, sym_index, h;
62 unsigned char *strtab;
63
64 strtab = s->link->data;
65 nb_syms = s->data_offset / sizeof(ElfW(Sym));
66
67 s->hash->data_offset = 0;
68 ptr = section_ptr_add(s->hash, (2 + nb_buckets + nb_syms) * sizeof(int));
69 ptr[0] = nb_buckets;
70 ptr[1] = nb_syms;
71 ptr += 2;
72 hash = ptr;
73 memset(hash, 0, (nb_buckets + 1) * sizeof(int));
74 ptr += nb_buckets + 1;
75
76 sym = (ElfW(Sym) *)s->data + 1;
77 for(sym_index = 1; sym_index < nb_syms; sym_index++) {
78 if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
79 h = elf_hash(strtab + sym->st_name) % nb_buckets;
80 *ptr = hash[h];
81 hash[h] = sym_index;
82 } else {
83 *ptr = 0;
84 }
85 ptr++;
86 sym++;
87 }
88 }
89
90 /* return the symbol number */
91 ST_FUNC int put_elf_sym(Section *s, addr_t value, unsigned long size,
92 int info, int other, int shndx, const char *name)
93 {
94 int name_offset, sym_index;
95 int nbuckets, h;
96 ElfW(Sym) *sym;
97 Section *hs;
98
99 sym = section_ptr_add(s, sizeof(ElfW(Sym)));
100 if (name)
101 name_offset = put_elf_str(s->link, name);
102 else
103 name_offset = 0;
104 /* XXX: endianness */
105 sym->st_name = name_offset;
106 sym->st_value = value;
107 sym->st_size = size;
108 sym->st_info = info;
109 sym->st_other = other;
110 sym->st_shndx = shndx;
111 sym_index = sym - (ElfW(Sym) *)s->data;
112 hs = s->hash;
113 if (hs) {
114 int *ptr, *base;
115 ptr = section_ptr_add(hs, sizeof(int));
116 base = (int *)hs->data;
117 /* only add global or weak symbols */
118 if (ELFW(ST_BIND)(info) != STB_LOCAL) {
119 /* add another hashing entry */
120 nbuckets = base[0];
121 h = elf_hash((unsigned char *) name) % nbuckets;
122 *ptr = base[2 + h];
123 base[2 + h] = sym_index;
124 base[1]++;
125 /* we resize the hash table */
126 hs->nb_hashed_syms++;
127 if (hs->nb_hashed_syms > 2 * nbuckets) {
128 rebuild_hash(s, 2 * nbuckets);
129 }
130 } else {
131 *ptr = 0;
132 base[1]++;
133 }
134 }
135 return sym_index;
136 }
137
138 /* find global ELF symbol 'name' and return its index. Return 0 if not
139 found. */
140 ST_FUNC int find_elf_sym(Section *s, const char *name)
141 {
142 ElfW(Sym) *sym;
143 Section *hs;
144 int nbuckets, sym_index, h;
145 const char *name1;
146
147 hs = s->hash;
148 if (!hs)
149 return 0;
150 nbuckets = ((int *)hs->data)[0];
151 h = elf_hash((unsigned char *) name) % nbuckets;
152 sym_index = ((int *)hs->data)[2 + h];
153 while (sym_index != 0) {
154 sym = &((ElfW(Sym) *)s->data)[sym_index];
155 name1 = (char *) s->link->data + sym->st_name;
156 if (!strcmp(name, name1))
157 return sym_index;
158 sym_index = ((int *)hs->data)[2 + nbuckets + sym_index];
159 }
160 return 0;
161 }
162
163 /* return elf symbol value, signal error if 'err' is nonzero */
164 ST_FUNC addr_t get_elf_sym_addr(TCCState *s, const char *name, int err)
165 {
166 int sym_index;
167 ElfW(Sym) *sym;
168
169 sym_index = find_elf_sym(s->symtab, name);
170 sym = &((ElfW(Sym) *)s->symtab->data)[sym_index];
171 if (!sym_index || sym->st_shndx == SHN_UNDEF) {
172 if (err)
173 tcc_error("%s not defined", name);
174 return 0;
175 }
176 return sym->st_value;
177 }
178
179 /* return elf symbol value */
180 LIBTCCAPI void *tcc_get_symbol(TCCState *s, const char *name)
181 {
182 return (void*)(uintptr_t)get_elf_sym_addr(s, name, 0);
183 }
184
185 #if defined TCC_IS_NATIVE || defined TCC_TARGET_PE
186 /* return elf symbol value or error */
187 ST_FUNC void* tcc_get_symbol_err(TCCState *s, const char *name)
188 {
189 return (void*)(uintptr_t)get_elf_sym_addr(s, name, 1);
190 }
191 #endif
192
193 /* add an elf symbol : check if it is already defined and patch
194 it. Return symbol index. NOTE that sh_num can be SHN_UNDEF. */
195 ST_FUNC int add_elf_sym(Section *s, addr_t value, unsigned long size,
196 int info, int other, int sh_num, const char *name)
197 {
198 ElfW(Sym) *esym;
199 int sym_bind, sym_index, sym_type, esym_bind;
200 unsigned char sym_vis, esym_vis, new_vis;
201
202 sym_bind = ELFW(ST_BIND)(info);
203 sym_type = ELFW(ST_TYPE)(info);
204 sym_vis = ELFW(ST_VISIBILITY)(other);
205
206 if (sym_bind != STB_LOCAL) {
207 /* we search global or weak symbols */
208 sym_index = find_elf_sym(s, name);
209 if (!sym_index)
210 goto do_def;
211 esym = &((ElfW(Sym) *)s->data)[sym_index];
212 if (esym->st_shndx != SHN_UNDEF) {
213 esym_bind = ELFW(ST_BIND)(esym->st_info);
214 /* propagate the most constraining visibility */
215 /* STV_DEFAULT(0)<STV_PROTECTED(3)<STV_HIDDEN(2)<STV_INTERNAL(1) */
216 esym_vis = ELFW(ST_VISIBILITY)(esym->st_other);
217 if (esym_vis == STV_DEFAULT) {
218 new_vis = sym_vis;
219 } else if (sym_vis == STV_DEFAULT) {
220 new_vis = esym_vis;
221 } else {
222 new_vis = (esym_vis < sym_vis) ? esym_vis : sym_vis;
223 }
224 esym->st_other = (esym->st_other & ~ELFW(ST_VISIBILITY)(-1))
225 | new_vis;
226 other = esym->st_other; /* in case we have to patch esym */
227 if (sh_num == SHN_UNDEF) {
228 /* ignore adding of undefined symbol if the
229 corresponding symbol is already defined */
230 } else if (sym_bind == STB_GLOBAL && esym_bind == STB_WEAK) {
231 /* global overrides weak, so patch */
232 goto do_patch;
233 } else if (sym_bind == STB_WEAK && esym_bind == STB_GLOBAL) {
234 /* weak is ignored if already global */
235 } else if (sym_bind == STB_WEAK && esym_bind == STB_WEAK) {
236 /* keep first-found weak definition, ignore subsequents */
237 } else if (sym_vis == STV_HIDDEN || sym_vis == STV_INTERNAL) {
238 /* ignore hidden symbols after */
239 } else if (esym->st_shndx == SHN_COMMON
240 && (sh_num < SHN_LORESERVE || sh_num == SHN_COMMON)) {
241 /* gr: Happens with 'tcc ... -static tcctest.c' on e.g. Ubuntu 6.01
242 No idea if this is the correct solution ... */
243 goto do_patch;
244 } else if (s == tcc_state->dynsymtab_section) {
245 /* we accept that two DLL define the same symbol */
246 } else {
247 #if 0
248 printf("new_bind=%x new_shndx=%x new_vis=%x old_bind=%x old_shndx=%x old_vis=%x\n",
249 sym_bind, sh_num, new_vis, esym_bind, esym->st_shndx, esym_vis);
250 #endif
251 tcc_error_noabort("'%s' defined twice... may be -fcommon is needed?", name);
252 }
253 } else {
254 do_patch:
255 esym->st_info = ELFW(ST_INFO)(sym_bind, sym_type);
256 esym->st_shndx = sh_num;
257 new_undef_sym = 1;
258 esym->st_value = value;
259 esym->st_size = size;
260 esym->st_other = other;
261 }
262 } else {
263 do_def:
264 sym_index = put_elf_sym(s, value, size,
265 ELFW(ST_INFO)(sym_bind, sym_type), other,
266 sh_num, name);
267 }
268 return sym_index;
269 }
270
271 /* put relocation */
272 ST_FUNC void put_elf_reloca(Section *symtab, Section *s, unsigned long offset,
273 int type, int symbol, addr_t addend)
274 {
275 char buf[256];
276 Section *sr;
277 ElfW_Rel *rel;
278
279 sr = s->reloc;
280 if (!sr) {
281 /* if no relocation section, create it */
282 snprintf(buf, sizeof(buf), REL_SECTION_FMT, s->name);
283 /* if the symtab is allocated, then we consider the relocation
284 are also */
285 sr = new_section(tcc_state, buf, SHT_RELX, symtab->sh_flags);
286 sr->sh_entsize = sizeof(ElfW_Rel);
287 sr->link = symtab;
288 sr->sh_info = s->sh_num;
289 s->reloc = sr;
290 }
291 rel = section_ptr_add(sr, sizeof(ElfW_Rel));
292 rel->r_offset = offset;
293 rel->r_info = ELFW(R_INFO)(symbol, type);
294 #if defined(TCC_TARGET_ARM64) || defined(TCC_TARGET_X86_64)
295 rel->r_addend = addend;
296 #else
297 if (addend)
298 tcc_error("non-zero addend on REL architecture");
299 #endif
300 }
301
302 ST_FUNC void put_elf_reloc(Section *symtab, Section *s, unsigned long offset,
303 int type, int symbol)
304 {
305 put_elf_reloca(symtab, s, offset, type, symbol, 0);
306 }
307
308 /* put stab debug information */
309
310 ST_FUNC void put_stabs(const char *str, int type, int other, int desc,
311 unsigned long value)
312 {
313 Stab_Sym *sym;
314
315 sym = section_ptr_add(stab_section, sizeof(Stab_Sym));
316 if (str) {
317 sym->n_strx = put_elf_str(stabstr_section, str);
318 } else {
319 sym->n_strx = 0;
320 }
321 sym->n_type = type;
322 sym->n_other = other;
323 sym->n_desc = desc;
324 sym->n_value = value;
325 }
326
327 ST_FUNC void put_stabs_r(const char *str, int type, int other, int desc,
328 unsigned long value, Section *sec, int sym_index)
329 {
330 put_stabs(str, type, other, desc, value);
331 put_elf_reloc(symtab_section, stab_section,
332 stab_section->data_offset - sizeof(unsigned int),
333 R_DATA_32, sym_index);
334 }
335
336 ST_FUNC void put_stabn(int type, int other, int desc, int value)
337 {
338 put_stabs(NULL, type, other, desc, value);
339 }
340
341 ST_FUNC void put_stabd(int type, int other, int desc)
342 {
343 put_stabs(NULL, type, other, desc, 0);
344 }
345
346 /* Browse each elem of type <type> in section <sec> starting at elem <startoff>
347 using variable <elem> */
348 #define for_each_elem(sec, startoff, elem, type) \
349 for (elem = (type *) sec->data + startoff; \
350 elem < (type *) (sec->data + sec->data_offset); elem++)
351
352 /* In an ELF file symbol table, the local symbols must appear below
353 the global and weak ones. Since TCC cannot sort it while generating
354 the code, we must do it after. All the relocation tables are also
355 modified to take into account the symbol table sorting */
356 static void sort_syms(TCCState *s1, Section *s)
357 {
358 int *old_to_new_syms;
359 ElfW(Sym) *new_syms;
360 int nb_syms, i;
361 ElfW(Sym) *p, *q;
362 ElfW_Rel *rel;
363 Section *sr;
364 int type, sym_index;
365
366 nb_syms = s->data_offset / sizeof(ElfW(Sym));
367 new_syms = tcc_malloc(nb_syms * sizeof(ElfW(Sym)));
368 old_to_new_syms = tcc_malloc(nb_syms * sizeof(int));
369
370 /* first pass for local symbols */
371 p = (ElfW(Sym) *)s->data;
372 q = new_syms;
373 for(i = 0; i < nb_syms; i++) {
374 if (ELFW(ST_BIND)(p->st_info) == STB_LOCAL) {
375 old_to_new_syms[i] = q - new_syms;
376 *q++ = *p;
377 }
378 p++;
379 }
380 /* save the number of local symbols in section header */
381 s->sh_info = q - new_syms;
382
383 /* then second pass for non local symbols */
384 p = (ElfW(Sym) *)s->data;
385 for(i = 0; i < nb_syms; i++) {
386 if (ELFW(ST_BIND)(p->st_info) != STB_LOCAL) {
387 old_to_new_syms[i] = q - new_syms;
388 *q++ = *p;
389 }
390 p++;
391 }
392
393 /* we copy the new symbols to the old */
394 memcpy(s->data, new_syms, nb_syms * sizeof(ElfW(Sym)));
395 tcc_free(new_syms);
396
397 /* now we modify all the relocations */
398 for(i = 1; i < s1->nb_sections; i++) {
399 sr = s1->sections[i];
400 if (sr->sh_type == SHT_RELX && sr->link == s) {
401 for_each_elem(sr, 0, rel, ElfW_Rel) {
402 sym_index = ELFW(R_SYM)(rel->r_info);
403 type = ELFW(R_TYPE)(rel->r_info);
404 sym_index = old_to_new_syms[sym_index];
405 rel->r_info = ELFW(R_INFO)(sym_index, type);
406 }
407 }
408 }
409
410 tcc_free(old_to_new_syms);
411 }
412
413 /* relocate common symbols in the .bss section */
414 ST_FUNC void relocate_common_syms(void)
415 {
416 ElfW(Sym) *sym;
417 unsigned long offset, align;
418
419 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
420 if (sym->st_shndx == SHN_COMMON) {
421 /* align symbol */
422 align = sym->st_value;
423 offset = bss_section->data_offset;
424 offset = (offset + align - 1) & -align;
425 sym->st_value = offset;
426 sym->st_shndx = bss_section->sh_num;
427 offset += sym->st_size;
428 bss_section->data_offset = offset;
429 }
430 }
431 }
432
433 /* relocate symbol table, resolve undefined symbols if do_resolve is
434 true and output error if undefined symbol. */
435 ST_FUNC void relocate_syms(TCCState *s1, int do_resolve)
436 {
437 ElfW(Sym) *sym, *esym;
438 int sym_bind, sh_num, sym_index;
439 const char *name;
440
441 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
442 sh_num = sym->st_shndx;
443 if (sh_num == SHN_UNDEF) {
444 name = (char *) strtab_section->data + sym->st_name;
445 /* Use ld.so to resolve symbol for us (for tcc -run) */
446 if (do_resolve) {
447 #if defined TCC_IS_NATIVE && !defined _WIN32
448 void *addr;
449 name = (char *) symtab_section->link->data + sym->st_name;
450 addr = resolve_sym(s1, name);
451 if (addr) {
452 sym->st_value = (addr_t)addr;
453 #ifdef DEBUG_RELOC
454 printf ("relocate_sym: %s -> 0x%lx\n", name, sym->st_value);
455 #endif
456 goto found;
457 }
458 #endif
459 } else if (s1->dynsym) {
460 /* if dynamic symbol exist, then use it */
461 sym_index = find_elf_sym(s1->dynsym, name);
462 if (sym_index) {
463 esym = &((ElfW(Sym) *)s1->dynsym->data)[sym_index];
464 sym->st_value = esym->st_value;
465 goto found;
466 }
467 }
468 /* XXX: _fp_hw seems to be part of the ABI, so we ignore
469 it */
470 if (!strcmp(name, "_fp_hw"))
471 goto found;
472 /* only weak symbols are accepted to be undefined. Their
473 value is zero */
474 sym_bind = ELFW(ST_BIND)(sym->st_info);
475 if (sym_bind == STB_WEAK) {
476 sym->st_value = 0;
477 } else {
478 tcc_error_noabort("undefined symbol '%s'", name);
479 }
480 } else if (sh_num < SHN_LORESERVE) {
481 /* add section base */
482 sym->st_value += s1->sections[sym->st_shndx]->sh_addr;
483 }
484 found: ;
485 }
486 }
487
488 /* relocate a given section (CPU dependent) by applying the relocations
489 in the associated relocation section */
490 ST_FUNC void relocate_section(TCCState *s1, Section *s)
491 {
492 Section *sr = s->reloc;
493 ElfW_Rel *rel;
494 ElfW(Sym) *sym;
495 int type, sym_index;
496 unsigned char *ptr;
497 addr_t val, addr;
498 #if defined TCC_TARGET_I386 || defined TCC_TARGET_X86_64
499 ElfW_Rel *qrel = (ElfW_Rel *) sr->data; /* ptr to next reloc entry reused */
500 int esym_index;
501 #endif
502
503 for_each_elem(sr, 0, rel, ElfW_Rel) {
504 ptr = s->data + rel->r_offset;
505
506 sym_index = ELFW(R_SYM)(rel->r_info);
507 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
508 val = sym->st_value;
509 #if defined(TCC_TARGET_ARM64) || defined(TCC_TARGET_X86_64)
510 val += rel->r_addend;
511 #endif
512 type = ELFW(R_TYPE)(rel->r_info);
513 addr = s->sh_addr + rel->r_offset;
514
515 /* CPU specific */
516 switch(type) {
517 #if defined(TCC_TARGET_I386)
518 case R_386_32:
519 if (s1->output_type == TCC_OUTPUT_DLL) {
520 esym_index = s1->symtab_to_dynsym[sym_index];
521 qrel->r_offset = rel->r_offset;
522 if (esym_index) {
523 qrel->r_info = ELFW(R_INFO)(esym_index, R_386_32);
524 qrel++;
525 break;
526 } else {
527 qrel->r_info = ELFW(R_INFO)(0, R_386_RELATIVE);
528 qrel++;
529 }
530 }
531 write32le(ptr, read32le(ptr) + val);
532 break;
533 case R_386_PC32:
534 if (s1->output_type == TCC_OUTPUT_DLL) {
535 /* DLL relocation */
536 esym_index = s1->symtab_to_dynsym[sym_index];
537 if (esym_index) {
538 qrel->r_offset = rel->r_offset;
539 qrel->r_info = ELFW(R_INFO)(esym_index, R_386_PC32);
540 qrel++;
541 break;
542 }
543 }
544 write32le(ptr, read32le(ptr) + val - addr);
545 break;
546 case R_386_PLT32:
547 write32le(ptr, read32le(ptr) + val - addr);
548 break;
549 case R_386_GLOB_DAT:
550 case R_386_JMP_SLOT:
551 write32le(ptr, val);
552 break;
553 case R_386_GOTPC:
554 write32le(ptr, read32le(ptr) + s1->got->sh_addr - addr);
555 break;
556 case R_386_GOTOFF:
557 write32le(ptr, read32le(ptr) + val - s1->got->sh_addr);
558 break;
559 case R_386_GOT32:
560 /* we load the got offset */
561 write32le(ptr, read32le(ptr) + s1->sym_attrs[sym_index].got_offset);
562 break;
563 case R_386_16:
564 if (s1->output_format != TCC_OUTPUT_FORMAT_BINARY) {
565 output_file:
566 tcc_error("can only produce 16-bit binary files");
567 }
568 write16le(ptr, read16le(ptr) + val);
569 break;
570 case R_386_PC16:
571 if (s1->output_format != TCC_OUTPUT_FORMAT_BINARY)
572 goto output_file;
573 write16le(ptr, read16le(ptr) + val - addr);
574 break;
575 #elif defined(TCC_TARGET_ARM)
576 case R_ARM_PC24:
577 case R_ARM_CALL:
578 case R_ARM_JUMP24:
579 case R_ARM_PLT32:
580 {
581 int x, is_thumb, is_call, h, blx_avail, is_bl, th_ko;
582 x = (*(int *) ptr) & 0xffffff;
583 if (sym->st_shndx == SHN_UNDEF)
584 val = s1->plt->sh_addr;
585 #ifdef DEBUG_RELOC
586 printf ("reloc %d: x=0x%x val=0x%x ", type, x, val);
587 #endif
588 (*(int *)ptr) &= 0xff000000;
589 if (x & 0x800000)
590 x -= 0x1000000;
591 x <<= 2;
592 blx_avail = (TCC_ARM_VERSION >= 5);
593 is_thumb = val & 1;
594 is_bl = (*(unsigned *) ptr) >> 24 == 0xeb;
595 is_call = (type == R_ARM_CALL || (type == R_ARM_PC24 && is_bl));
596 x += val - addr;
597 #ifdef DEBUG_RELOC
598 printf (" newx=0x%x name=%s\n", x,
599 (char *) symtab_section->link->data + sym->st_name);
600 #endif
601 h = x & 2;
602 th_ko = (x & 3) && (!blx_avail || !is_call);
603 if (th_ko || x >= 0x2000000 || x < -0x2000000)
604 tcc_error("can't relocate value at %x,%d",addr, type);
605 x >>= 2;
606 x &= 0xffffff;
607 /* Only reached if blx is avail and it is a call */
608 if (is_thumb) {
609 x |= h << 24;
610 (*(int *)ptr) = 0xfa << 24; /* bl -> blx */
611 }
612 (*(int *) ptr) |= x;
613 }
614 break;
615 /* Since these relocations only concern Thumb-2 and blx instruction was
616 introduced before Thumb-2, we can assume blx is available and not
617 guard its use */
618 case R_ARM_THM_PC22:
619 case R_ARM_THM_JUMP24:
620 {
621 int x, hi, lo, s, j1, j2, i1, i2, imm10, imm11;
622 int to_thumb, is_call, to_plt, blx_bit = 1 << 12;
623 Section *plt;
624
625 /* weak reference */
626 if (sym->st_shndx == SHN_UNDEF &&
627 ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
628 break;
629
630 /* Get initial offset */
631 hi = (*(uint16_t *)ptr);
632 lo = (*(uint16_t *)(ptr+2));
633 s = (hi >> 10) & 1;
634 j1 = (lo >> 13) & 1;
635 j2 = (lo >> 11) & 1;
636 i1 = (j1 ^ s) ^ 1;
637 i2 = (j2 ^ s) ^ 1;
638 imm10 = hi & 0x3ff;
639 imm11 = lo & 0x7ff;
640 x = (s << 24) | (i1 << 23) | (i2 << 22) |
641 (imm10 << 12) | (imm11 << 1);
642 if (x & 0x01000000)
643 x -= 0x02000000;
644
645 /* Relocation infos */
646 to_thumb = val & 1;
647 plt = s1->plt;
648 to_plt = (val >= plt->sh_addr) &&
649 (val < plt->sh_addr + plt->data_offset);
650 is_call = (type == R_ARM_THM_PC22);
651
652 /* Compute final offset */
653 if (to_plt && !is_call) /* Point to 1st instr of Thumb stub */
654 x -= 4;
655 x += val - addr;
656 if (!to_thumb && is_call) {
657 blx_bit = 0; /* bl -> blx */
658 x = (x + 3) & -4; /* Compute offset from aligned PC */
659 }
660
661 /* Check that relocation is possible
662 * offset must not be out of range
663 * if target is to be entered in arm mode:
664 - bit 1 must not set
665 - instruction must be a call (bl) or a jump to PLT */
666 if (!to_thumb || x >= 0x1000000 || x < -0x1000000)
667 if (to_thumb || (val & 2) || (!is_call && !to_plt))
668 tcc_error("can't relocate value at %x,%d",addr, type);
669
670 /* Compute and store final offset */
671 s = (x >> 24) & 1;
672 i1 = (x >> 23) & 1;
673 i2 = (x >> 22) & 1;
674 j1 = s ^ (i1 ^ 1);
675 j2 = s ^ (i2 ^ 1);
676 imm10 = (x >> 12) & 0x3ff;
677 imm11 = (x >> 1) & 0x7ff;
678 (*(uint16_t *)ptr) = (uint16_t) ((hi & 0xf800) |
679 (s << 10) | imm10);
680 (*(uint16_t *)(ptr+2)) = (uint16_t) ((lo & 0xc000) |
681 (j1 << 13) | blx_bit | (j2 << 11) |
682 imm11);
683 }
684 break;
685 case R_ARM_MOVT_ABS:
686 case R_ARM_MOVW_ABS_NC:
687 {
688 int x, imm4, imm12;
689 if (type == R_ARM_MOVT_ABS)
690 val >>= 16;
691 imm12 = val & 0xfff;
692 imm4 = (val >> 12) & 0xf;
693 x = (imm4 << 16) | imm12;
694 if (type == R_ARM_THM_MOVT_ABS)
695 *(int *)ptr |= x;
696 else
697 *(int *)ptr += x;
698 }
699 break;
700 case R_ARM_THM_MOVT_ABS:
701 case R_ARM_THM_MOVW_ABS_NC:
702 {
703 int x, i, imm4, imm3, imm8;
704 if (type == R_ARM_THM_MOVT_ABS)
705 val >>= 16;
706 imm8 = val & 0xff;
707 imm3 = (val >> 8) & 0x7;
708 i = (val >> 11) & 1;
709 imm4 = (val >> 12) & 0xf;
710 x = (imm3 << 28) | (imm8 << 16) | (i << 10) | imm4;
711 if (type == R_ARM_THM_MOVT_ABS)
712 *(int *)ptr |= x;
713 else
714 *(int *)ptr += x;
715 }
716 break;
717 case R_ARM_PREL31:
718 {
719 int x;
720 x = (*(int *)ptr) & 0x7fffffff;
721 (*(int *)ptr) &= 0x80000000;
722 x = (x * 2) / 2;
723 x += val - addr;
724 if((x^(x>>1))&0x40000000)
725 tcc_error("can't relocate value at %x,%d",addr, type);
726 (*(int *)ptr) |= x & 0x7fffffff;
727 }
728 case R_ARM_ABS32:
729 *(int *)ptr += val;
730 break;
731 case R_ARM_REL32:
732 *(int *)ptr += val - addr;
733 break;
734 case R_ARM_GOTPC:
735 *(int *)ptr += s1->got->sh_addr - addr;
736 break;
737 case R_ARM_GOTOFF:
738 *(int *)ptr += val - s1->got->sh_addr;
739 break;
740 case R_ARM_GOT32:
741 /* we load the got offset */
742 *(int *)ptr += s1->sym_attrs[sym_index].got_offset;
743 break;
744 case R_ARM_COPY:
745 break;
746 case R_ARM_V4BX:
747 /* trade Thumb support for ARMv4 support */
748 if ((0x0ffffff0 & *(int*)ptr) == 0x012FFF10)
749 *(int*)ptr ^= 0xE12FFF10 ^ 0xE1A0F000; /* BX Rm -> MOV PC, Rm */
750 break;
751 case R_ARM_GLOB_DAT:
752 case R_ARM_JUMP_SLOT:
753 *(addr_t *)ptr = val;
754 break;
755 case R_ARM_NONE:
756 /* Nothing to do. Normally used to indicate a dependency
757 on a certain symbol (like for exception handling under EABI). */
758 break;
759 default:
760 fprintf(stderr,"FIXME: handle reloc type %x at %x [%p] to %x\n",
761 type, (unsigned)addr, ptr, (unsigned)val);
762 break;
763 #elif defined(TCC_TARGET_ARM64)
764 case R_AARCH64_ABS64:
765 write64le(ptr, val);
766 break;
767 case R_AARCH64_ABS32:
768 write32le(ptr, val);
769 break;
770 case R_AARCH64_MOVW_UABS_G0_NC:
771 write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
772 (val & 0xffff) << 5));
773 break;
774 case R_AARCH64_MOVW_UABS_G1_NC:
775 write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
776 (val >> 16 & 0xffff) << 5));
777 break;
778 case R_AARCH64_MOVW_UABS_G2_NC:
779 write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
780 (val >> 32 & 0xffff) << 5));
781 break;
782 case R_AARCH64_MOVW_UABS_G3:
783 write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
784 (val >> 48 & 0xffff) << 5));
785 break;
786 case R_AARCH64_ADR_PREL_PG_HI21: {
787 uint64_t off = (val >> 12) - (addr >> 12);
788 if ((off + ((uint64_t)1 << 20)) >> 21)
789 tcc_error("R_AARCH64_ADR_PREL_PG_HI21 relocation failed");
790 write32le(ptr, ((read32le(ptr) & 0x9f00001f) |
791 (off & 0x1ffffc) << 3 | (off & 3) << 29));
792 break;
793 }
794 case R_AARCH64_ADD_ABS_LO12_NC:
795 write32le(ptr, ((read32le(ptr) & 0xffc003ff) |
796 (val & 0xfff) << 10));
797 break;
798 case R_AARCH64_JUMP26:
799 case R_AARCH64_CALL26:
800 /* This check must match the one in build_got_entries, testing
801 if we really need a PLT slot. */
802 if (sym->st_shndx == SHN_UNDEF)
803 /* We've put the PLT slot offset into r_addend when generating
804 it, and that's what we must use as relocation value (adjusted
805 by section offset of course). */
806 val = s1->plt->sh_addr + rel->r_addend;
807 #ifdef DEBUG_RELOC
808 printf ("reloc %d @ 0x%lx: val=0x%lx name=%s\n", type, addr, val,
809 (char *) symtab_section->link->data + sym->st_name);
810 #endif
811 if (((val - addr) + ((uint64_t)1 << 27)) & ~(uint64_t)0xffffffc)
812 {
813 tcc_error("R_AARCH64_(JUMP|CALL)26 relocation failed (val=%lx, addr=%lx)", addr, val);
814 }
815 write32le(ptr, (0x14000000 |
816 (uint32_t)(type == R_AARCH64_CALL26) << 31 |
817 ((val - addr) >> 2 & 0x3ffffff)));
818 break;
819 case R_AARCH64_ADR_GOT_PAGE: {
820 uint64_t off =
821 (((s1->got->sh_addr +
822 s1->sym_attrs[sym_index].got_offset) >> 12) - (addr >> 12));
823 if ((off + ((uint64_t)1 << 20)) >> 21)
824 tcc_error("R_AARCH64_ADR_GOT_PAGE relocation failed");
825 write32le(ptr, ((read32le(ptr) & 0x9f00001f) |
826 (off & 0x1ffffc) << 3 | (off & 3) << 29));
827 break;
828 }
829 case R_AARCH64_LD64_GOT_LO12_NC:
830 write32le(ptr,
831 ((read32le(ptr) & 0xfff803ff) |
832 ((s1->got->sh_addr +
833 s1->sym_attrs[sym_index].got_offset) & 0xff8) << 7));
834 break;
835 case R_AARCH64_COPY:
836 break;
837 case R_AARCH64_GLOB_DAT:
838 case R_AARCH64_JUMP_SLOT:
839 /* They don't need addend */
840 #ifdef DEBUG_RELOC
841 printf ("reloc %d @ 0x%lx: val=0x%lx name=%s\n", type, addr,
842 val - rel->r_addend,
843 (char *) symtab_section->link->data + sym->st_name);
844 #endif
845 write64le(ptr, val - rel->r_addend);
846 break;
847 default:
848 fprintf(stderr, "FIXME: handle reloc type %x at %x [%p] to %x\n",
849 type, (unsigned)addr, ptr, (unsigned)val);
850 break;
851 #elif defined(TCC_TARGET_C67)
852 case R_C60_32:
853 *(int *)ptr += val;
854 break;
855 case R_C60LO16:
856 {
857 uint32_t orig;
858
859 /* put the low 16 bits of the absolute address
860 add to what is already there */
861
862 orig = ((*(int *)(ptr )) >> 7) & 0xffff;
863 orig |= (((*(int *)(ptr+4)) >> 7) & 0xffff) << 16;
864
865 /* patch both at once - assumes always in pairs Low - High */
866
867 *(int *) ptr = (*(int *) ptr & (~(0xffff << 7)) ) | (((val+orig) & 0xffff) << 7);
868 *(int *)(ptr+4) = (*(int *)(ptr+4) & (~(0xffff << 7)) ) | ((((val+orig)>>16) & 0xffff) << 7);
869 }
870 break;
871 case R_C60HI16:
872 break;
873 default:
874 fprintf(stderr,"FIXME: handle reloc type %x at %x [%p] to %x\n",
875 type, (unsigned)addr, ptr, (unsigned)val);
876 break;
877 #elif defined(TCC_TARGET_X86_64)
878 case R_X86_64_64:
879 if (s1->output_type == TCC_OUTPUT_DLL) {
880 esym_index = s1->symtab_to_dynsym[sym_index];
881 qrel->r_offset = rel->r_offset;
882 if (esym_index) {
883 qrel->r_info = ELFW(R_INFO)(esym_index, R_X86_64_64);
884 qrel->r_addend = rel->r_addend;
885 qrel++;
886 break;
887 } else {
888 qrel->r_info = ELFW(R_INFO)(0, R_X86_64_RELATIVE);
889 qrel->r_addend = read64le(ptr) + val;
890 qrel++;
891 }
892 }
893 write64le(ptr, read64le(ptr) + val);
894 break;
895 case R_X86_64_32:
896 case R_X86_64_32S:
897 if (s1->output_type == TCC_OUTPUT_DLL) {
898 /* XXX: this logic may depend on TCC's codegen
899 now TCC uses R_X86_64_32 even for a 64bit pointer */
900 qrel->r_info = ELFW(R_INFO)(0, R_X86_64_RELATIVE);
901 qrel->r_addend = read32le(ptr) + val;
902 qrel++;
903 }
904 write32le(ptr, read32le(ptr) + val);
905 break;
906
907 case R_X86_64_PC32:
908 if (s1->output_type == TCC_OUTPUT_DLL) {
909 /* DLL relocation */
910 esym_index = s1->symtab_to_dynsym[sym_index];
911 if (esym_index) {
912 qrel->r_offset = rel->r_offset;
913 qrel->r_info = ELFW(R_INFO)(esym_index, R_X86_64_PC32);
914 qrel->r_addend = read32le(ptr);
915 qrel++;
916 break;
917 }
918 }
919 goto plt32pc32;
920
921 case R_X86_64_PLT32:
922 /* We've put the PLT slot offset into r_addend when generating
923 it, and that's what we must use as relocation value (adjusted
924 by section offset of course). */
925 val = s1->plt->sh_addr + rel->r_addend;
926 /* fallthrough. */
927
928 plt32pc32:
929 {
930 long long diff;
931 diff = (long long)val - addr;
932 if (diff < -2147483648LL || diff > 2147483647LL) {
933 tcc_error("internal error: relocation failed");
934 }
935 write32le(ptr, read32le(ptr) + diff);
936 }
937 break;
938 case R_X86_64_GLOB_DAT:
939 case R_X86_64_JUMP_SLOT:
940 /* They don't need addend */
941 write64le(ptr, val - rel->r_addend);
942 break;
943 case R_X86_64_GOTPCREL:
944 case 41 /* R_X86_64_GOTPCRELX */:
945 case 42 /* R_X86_64_REX_GOTPCRELX */:
946 write32le(ptr, read32le(ptr) +
947 (s1->got->sh_addr - addr +
948 s1->sym_attrs[sym_index].got_offset - 4));
949 break;
950 case R_X86_64_GOTTPOFF:
951 write32le(ptr, read32le(ptr) + val - s1->got->sh_addr);
952 break;
953 case R_X86_64_GOT32:
954 /* we load the got offset */
955 write32le(ptr, read32le(ptr) + s1->sym_attrs[sym_index].got_offset);
956 break;
957 #else
958 #error unsupported processor
959 #endif
960 }
961 }
962 /* if the relocation is allocated, we change its symbol table */
963 if (sr->sh_flags & SHF_ALLOC)
964 sr->link = s1->dynsym;
965 }
966
967 /* relocate relocation table in 'sr' */
968 static void relocate_rel(TCCState *s1, Section *sr)
969 {
970 Section *s;
971 ElfW_Rel *rel;
972
973 s = s1->sections[sr->sh_info];
974 for_each_elem(sr, 0, rel, ElfW_Rel)
975 rel->r_offset += s->sh_addr;
976 }
977
978 /* count the number of dynamic relocations so that we can reserve
979 their space */
980 static int prepare_dynamic_rel(TCCState *s1, Section *sr)
981 {
982 ElfW_Rel *rel;
983 int sym_index, esym_index, type, count;
984
985 count = 0;
986 for_each_elem(sr, 0, rel, ElfW_Rel) {
987 sym_index = ELFW(R_SYM)(rel->r_info);
988 type = ELFW(R_TYPE)(rel->r_info);
989 switch(type) {
990 #if defined(TCC_TARGET_I386)
991 case R_386_32:
992 #elif defined(TCC_TARGET_X86_64)
993 case R_X86_64_32:
994 case R_X86_64_32S:
995 case R_X86_64_64:
996 #endif
997 count++;
998 break;
999 #if defined(TCC_TARGET_I386)
1000 case R_386_PC32:
1001 #elif defined(TCC_TARGET_X86_64)
1002 case R_X86_64_PC32:
1003 #endif
1004 esym_index = s1->symtab_to_dynsym[sym_index];
1005 if (esym_index)
1006 count++;
1007 break;
1008 default:
1009 break;
1010 }
1011 }
1012 if (count) {
1013 /* allocate the section */
1014 sr->sh_flags |= SHF_ALLOC;
1015 sr->sh_size = count * sizeof(ElfW_Rel);
1016 }
1017 return count;
1018 }
1019
1020 static struct sym_attr *alloc_sym_attr(TCCState *s1, int index)
1021 {
1022 int n;
1023 struct sym_attr *tab;
1024
1025 if (index >= s1->nb_sym_attrs) {
1026 /* find immediately bigger power of 2 and reallocate array */
1027 n = 1;
1028 while (index >= n)
1029 n *= 2;
1030 tab = tcc_realloc(s1->sym_attrs, n * sizeof(*s1->sym_attrs));
1031 s1->sym_attrs = tab;
1032 memset(s1->sym_attrs + s1->nb_sym_attrs, 0,
1033 (n - s1->nb_sym_attrs) * sizeof(*s1->sym_attrs));
1034 s1->nb_sym_attrs = n;
1035 }
1036 return &s1->sym_attrs[index];
1037 }
1038
1039 static void build_got(TCCState *s1)
1040 {
1041 unsigned char *ptr;
1042
1043 /* if no got, then create it */
1044 s1->got = new_section(s1, ".got", SHT_PROGBITS, SHF_ALLOC | SHF_WRITE);
1045 s1->got->sh_entsize = 4;
1046 add_elf_sym(symtab_section, 0, 4, ELFW(ST_INFO)(STB_GLOBAL, STT_OBJECT),
1047 0, s1->got->sh_num, "_GLOBAL_OFFSET_TABLE_");
1048 ptr = section_ptr_add(s1->got, 3 * PTR_SIZE);
1049 #if PTR_SIZE == 4
1050 /* keep space for _DYNAMIC pointer, if present */
1051 write32le(ptr, 0);
1052 /* two dummy got entries */
1053 write32le(ptr + 4, 0);
1054 write32le(ptr + 8, 0);
1055 #else
1056 /* keep space for _DYNAMIC pointer, if present */
1057 write32le(ptr, 0);
1058 write32le(ptr + 4, 0);
1059 /* two dummy got entries */
1060 write32le(ptr + 8, 0);
1061 write32le(ptr + 12, 0);
1062 write32le(ptr + 16, 0);
1063 write32le(ptr + 20, 0);
1064 #endif
1065 }
1066
1067 /* put a got or plt entry corresponding to a symbol in symtab_section. 'size'
1068 and 'info' can be modifed if more precise info comes from the DLL.
1069 Returns offset of GOT or PLT slot. */
1070 static unsigned long put_got_entry(TCCState *s1,
1071 int reloc_type, unsigned long size, int info,
1072 int sym_index)
1073 {
1074 int index, need_plt_entry;
1075 const char *name;
1076 ElfW(Sym) *sym;
1077 unsigned long offset;
1078 int *ptr;
1079 struct sym_attr *symattr;
1080
1081 if (!s1->got)
1082 build_got(s1);
1083
1084 need_plt_entry =
1085 #ifdef TCC_TARGET_X86_64
1086 (reloc_type == R_X86_64_JUMP_SLOT);
1087 #elif defined(TCC_TARGET_I386)
1088 (reloc_type == R_386_JMP_SLOT);
1089 #elif defined(TCC_TARGET_ARM)
1090 (reloc_type == R_ARM_JUMP_SLOT);
1091 #elif defined(TCC_TARGET_ARM64)
1092 (reloc_type == R_AARCH64_JUMP_SLOT);
1093 #else
1094 0;
1095 #endif
1096
1097 if (need_plt_entry && !s1->plt) {
1098 /* add PLT */
1099 s1->plt = new_section(s1, ".plt", SHT_PROGBITS,
1100 SHF_ALLOC | SHF_EXECINSTR);
1101 s1->plt->sh_entsize = 4;
1102 }
1103
1104 /* If a got/plt entry already exists for that symbol, no need to add one */
1105 if (sym_index < s1->nb_sym_attrs) {
1106 if (need_plt_entry && s1->sym_attrs[sym_index].plt_offset)
1107 return s1->sym_attrs[sym_index].plt_offset;
1108 else if (!need_plt_entry && s1->sym_attrs[sym_index].got_offset)
1109 return s1->sym_attrs[sym_index].got_offset;
1110 }
1111
1112 symattr = alloc_sym_attr(s1, sym_index);
1113
1114 /* Only store the GOT offset if it's not generated for the PLT entry. */
1115 if (!need_plt_entry)
1116 symattr->got_offset = s1->got->data_offset;
1117
1118 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1119 name = (char *) symtab_section->link->data + sym->st_name;
1120 offset = sym->st_value;
1121 #if defined(TCC_TARGET_I386) || defined(TCC_TARGET_X86_64)
1122 if (need_plt_entry) {
1123 Section *plt;
1124 uint8_t *p;
1125 int modrm;
1126 unsigned long relofs;
1127
1128 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
1129 modrm = 0x25;
1130 #else
1131 /* if we build a DLL, we add a %ebx offset */
1132 if (s1->output_type == TCC_OUTPUT_DLL)
1133 modrm = 0xa3;
1134 else
1135 modrm = 0x25;
1136 #endif
1137
1138 /* add a PLT entry */
1139 plt = s1->plt;
1140 if (plt->data_offset == 0) {
1141 /* first plt entry */
1142 p = section_ptr_add(plt, 16);
1143 p[0] = 0xff; /* pushl got + PTR_SIZE */
1144 p[1] = modrm + 0x10;
1145 write32le(p + 2, PTR_SIZE);
1146 p[6] = 0xff; /* jmp *(got + PTR_SIZE * 2) */
1147 p[7] = modrm;
1148 write32le(p + 8, PTR_SIZE * 2);
1149 }
1150
1151 /* The PLT slot refers to the relocation entry it needs
1152 via offset. The reloc entry is created below, so its
1153 offset is the current data_offset. */
1154 relofs = s1->got->reloc ? s1->got->reloc->data_offset : 0;
1155 symattr->plt_offset = plt->data_offset;
1156 p = section_ptr_add(plt, 16);
1157 p[0] = 0xff; /* jmp *(got + x) */
1158 p[1] = modrm;
1159 write32le(p + 2, s1->got->data_offset);
1160 p[6] = 0x68; /* push $xxx */
1161 #ifdef TCC_TARGET_X86_64
1162 /* On x86-64, the relocation is referred to by _index_. */
1163 write32le(p + 7, relofs / sizeof (ElfW_Rel));
1164 #else
1165 write32le(p + 7, relofs);
1166 #endif
1167 p[11] = 0xe9; /* jmp plt_start */
1168 write32le(p + 12, -(plt->data_offset));
1169
1170 /* If this was an UNDEF symbol set the offset in the
1171 dynsymtab to the PLT slot, so that PC32 relocs to it
1172 can be resolved. */
1173 if (sym->st_shndx == SHN_UNDEF)
1174 offset = plt->data_offset - 16;
1175 }
1176 #elif defined(TCC_TARGET_ARM)
1177 if (need_plt_entry) {
1178 Section *plt;
1179 uint8_t *p;
1180
1181 /* if we build a DLL, we add a %ebx offset */
1182 if (s1->output_type == TCC_OUTPUT_DLL)
1183 tcc_error("DLLs unimplemented!");
1184
1185 /* add a PLT entry */
1186 plt = s1->plt;
1187 if (plt->data_offset == 0) {
1188 /* first plt entry */
1189 p = section_ptr_add(plt, 16);
1190 write32le(p, 0xe52de004); /* push {lr} */
1191 write32le(p+4, 0xe59fe010); /* ldr lr, [pc, #16] */
1192 write32le(p+8, 0xe08fe00e); /* add lr, pc, lr */
1193 write32le(p+12, 0xe5bef008); /* ldr pc, [lr, #8]! */
1194 }
1195
1196 symattr->plt_offset = plt->data_offset;
1197 if (symattr->plt_thumb_stub) {
1198 p = section_ptr_add(plt, 20);
1199 write32le(p, 0x4778); /* bx pc */
1200 write32le(p+2, 0x46c0); /* nop */
1201 p += 4;
1202 } else
1203 p = section_ptr_add(plt, 16);
1204 write32le(p, 0xe59fc004); /* ldr ip, [pc, #4] ; GOT entry offset */
1205 write32le(p+4, 0xe08fc00c); /* add ip, pc, ip ; addr of GOT entry */
1206 write32le(p+8, 0xe59cf000); /* ldr pc, [ip] ; jump to GOT entry */
1207 write32le(p+12, s1->got->data_offset); /* GOT entry off once patched */
1208
1209 /* the symbol is modified so that it will be relocated to
1210 the PLT */
1211 if (sym->st_shndx == SHN_UNDEF)
1212 offset = plt->data_offset - 16;
1213 }
1214 #elif defined(TCC_TARGET_ARM64)
1215 if (need_plt_entry) {
1216 Section *plt;
1217 uint8_t *p;
1218
1219 if (s1->output_type == TCC_OUTPUT_DLL)
1220 tcc_error("DLLs unimplemented!");
1221
1222 plt = s1->plt;
1223 if (plt->data_offset == 0)
1224 section_ptr_add(plt, 32);
1225 symattr->plt_offset = plt->data_offset;
1226 p = section_ptr_add(plt, 16);
1227 write32le(p, s1->got->data_offset);
1228 write32le(p + 4, (uint64_t)s1->got->data_offset >> 32);
1229
1230 if (sym->st_shndx == SHN_UNDEF)
1231 offset = plt->data_offset - 16;
1232 }
1233 #elif defined(TCC_TARGET_C67)
1234 if (s1->dynsym) {
1235 tcc_error("C67 got not implemented");
1236 }
1237 #else
1238 #error unsupported CPU
1239 #endif
1240 if (s1->dynsym) {
1241 /* XXX This might generate multiple syms for name. */
1242 index = put_elf_sym(s1->dynsym, offset,
1243 size, info, 0, sym->st_shndx, name);
1244 /* Create the relocation (it's against the GOT for PLT
1245 and GOT relocs). */
1246 put_elf_reloc(s1->dynsym, s1->got,
1247 s1->got->data_offset,
1248 reloc_type, index);
1249 } else {
1250 /* Without .dynsym (i.e. static link or memory output) we
1251 still need relocs against the generated got, so as to fill
1252 the entries with the symbol values (determined later). */
1253 put_elf_reloc(symtab_section, s1->got,
1254 s1->got->data_offset,
1255 reloc_type, sym_index);
1256 }
1257 /* And now create the GOT slot itself. */
1258 ptr = section_ptr_add(s1->got, PTR_SIZE);
1259 *ptr = 0;
1260 if (need_plt_entry)
1261 return symattr->plt_offset;
1262 else
1263 return symattr->got_offset;
1264 }
1265
1266 /* build GOT and PLT entries */
1267 ST_FUNC void build_got_entries(TCCState *s1)
1268 {
1269 Section *s;
1270 ElfW_Rel *rel;
1271 ElfW(Sym) *sym;
1272 int i, type, reloc_type, sym_index;
1273
1274 for(i = 1; i < s1->nb_sections; i++) {
1275 s = s1->sections[i];
1276 if (s->sh_type != SHT_RELX)
1277 continue;
1278 /* no need to handle got relocations */
1279 if (s->link != symtab_section)
1280 continue;
1281 for_each_elem(s, 0, rel, ElfW_Rel) {
1282 type = ELFW(R_TYPE)(rel->r_info);
1283 switch(type) {
1284 #if defined(TCC_TARGET_I386)
1285 case R_386_GOT32:
1286 case R_386_GOTOFF:
1287 case R_386_GOTPC:
1288 case R_386_PLT32:
1289 if (!s1->got)
1290 build_got(s1);
1291 if (type == R_386_GOT32 || type == R_386_PLT32) {
1292 sym_index = ELFW(R_SYM)(rel->r_info);
1293 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1294 /* look at the symbol got offset. If none, then add one */
1295 if (type == R_386_GOT32)
1296 reloc_type = R_386_GLOB_DAT;
1297 else
1298 reloc_type = R_386_JMP_SLOT;
1299 put_got_entry(s1, reloc_type, sym->st_size, sym->st_info,
1300 sym_index);
1301 }
1302 break;
1303 #elif defined(TCC_TARGET_ARM)
1304 case R_ARM_PC24:
1305 case R_ARM_CALL:
1306 case R_ARM_JUMP24:
1307 case R_ARM_GOT32:
1308 case R_ARM_GOTOFF:
1309 case R_ARM_GOTPC:
1310 case R_ARM_PLT32:
1311 if (!s1->got)
1312 build_got(s1);
1313 sym_index = ELFW(R_SYM)(rel->r_info);
1314 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1315 if (type != R_ARM_GOTOFF && type != R_ARM_GOTPC
1316 && sym->st_shndx == SHN_UNDEF) {
1317 unsigned long ofs;
1318 /* look at the symbol got offset. If none, then add one */
1319 if (type == R_ARM_GOT32)
1320 reloc_type = R_ARM_GLOB_DAT;
1321 else
1322 reloc_type = R_ARM_JUMP_SLOT;
1323 ofs = put_got_entry(s1, reloc_type, sym->st_size,
1324 sym->st_info, sym_index);
1325 #ifdef DEBUG_RELOC
1326 printf ("maybegot: %s, %d, %d --> ofs=0x%x\n",
1327 (char *) symtab_section->link->data + sym->st_name,
1328 type, sym->st_shndx, ofs);
1329 #endif
1330 if (type != R_ARM_GOT32) {
1331 addr_t *ptr = (addr_t*)(s1->sections[s->sh_info]->data
1332 + rel->r_offset);
1333 /* x must be signed! */
1334 int x = *ptr & 0xffffff;
1335 x = (x << 8) >> 8;
1336 x <<= 2;
1337 x += ofs;
1338 x >>= 2;
1339 #ifdef DEBUG_RELOC
1340 printf ("insn=0x%x --> 0x%x (x==0x%x)\n", *ptr,
1341 (*ptr & 0xff000000) | x, x);
1342 #endif
1343 *ptr = (*ptr & 0xff000000) | x;
1344 }
1345 }
1346 break;
1347 case R_ARM_THM_JUMP24:
1348 sym_index = ELFW(R_SYM)(rel->r_info);
1349 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1350 /* We are relocating a jump from thumb code to arm code */
1351 if (sym->st_shndx != SHN_UNDEF && !(sym->st_value & 1)) {
1352 int index;
1353 uint8_t *p;
1354 char *name, buf[1024];
1355 Section *text_section;
1356
1357 name = (char *) symtab_section->link->data + sym->st_name;
1358 text_section = s1->sections[sym->st_shndx];
1359 /* Modify reloc to target a thumb stub to switch to ARM */
1360 snprintf(buf, sizeof(buf), "%s_from_thumb", name);
1361 index = put_elf_sym(symtab_section,
1362 text_section->data_offset + 1,
1363 sym->st_size, sym->st_info, 0,
1364 sym->st_shndx, buf);
1365 rel->r_info = ELFW(R_INFO)(index, type);
1366 /* Create a thumb stub fonction to switch to ARM mode */
1367 put_elf_reloc(symtab_section, text_section,
1368 text_section->data_offset + 4, R_ARM_JUMP24,
1369 sym_index);
1370 p = section_ptr_add(text_section, 8);
1371 write32le(p, 0x4778); /* bx pc */
1372 write32le(p+2, 0x46c0); /* nop */
1373 write32le(p+4, 0xeafffffe); /* b $sym */
1374 }
1375 #elif defined(TCC_TARGET_ARM64)
1376 //xx Other cases may be required here:
1377 case R_AARCH64_ADR_GOT_PAGE:
1378 case R_AARCH64_LD64_GOT_LO12_NC:
1379 if (!s1->got)
1380 build_got(s1);
1381 sym_index = ELFW(R_SYM)(rel->r_info);
1382 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1383 reloc_type = R_AARCH64_GLOB_DAT;
1384 put_got_entry(s1, reloc_type, sym->st_size, sym->st_info,
1385 sym_index);
1386 break;
1387
1388 case R_AARCH64_JUMP26:
1389 case R_AARCH64_CALL26:
1390 if (!s1->got)
1391 build_got(s1);
1392 sym_index = ELFW(R_SYM)(rel->r_info);
1393 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1394 if (sym->st_shndx == SHN_UNDEF) {
1395 unsigned long ofs;
1396 reloc_type = R_AARCH64_JUMP_SLOT;
1397 ofs = put_got_entry(s1, reloc_type, sym->st_size,
1398 sym->st_info, sym_index);
1399 /* We store the place of the generated PLT slot
1400 in our addend. */
1401 rel->r_addend += ofs;
1402 }
1403 break;
1404 #elif defined(TCC_TARGET_C67)
1405 case R_C60_GOT32:
1406 case R_C60_GOTOFF:
1407 case R_C60_GOTPC:
1408 case R_C60_PLT32:
1409 if (!s1->got)
1410 build_got(s1);
1411 if (type == R_C60_GOT32 || type == R_C60_PLT32) {
1412 sym_index = ELFW(R_SYM)(rel->r_info);
1413 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1414 /* look at the symbol got offset. If none, then add one */
1415 if (type == R_C60_GOT32)
1416 reloc_type = R_C60_GLOB_DAT;
1417 else
1418 reloc_type = R_C60_JMP_SLOT;
1419 put_got_entry(s1, reloc_type, sym->st_size, sym->st_info,
1420 sym_index);
1421 }
1422 break;
1423 #elif defined(TCC_TARGET_X86_64)
1424 case R_X86_64_GOT32:
1425 case R_X86_64_GOTTPOFF:
1426 case R_X86_64_GOTPCREL:
1427 case 41 /* R_X86_64_GOTPCRELX */:
1428 case 42 /* R_X86_64_REX_GOTPCRELX */:
1429 case R_X86_64_PLT32:
1430 sym_index = ELFW(R_SYM)(rel->r_info);
1431 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1432 if (type == R_X86_64_PLT32 &&
1433 ELFW(ST_VISIBILITY)(sym->st_other) != STV_DEFAULT)
1434 {
1435 rel->r_info = ELFW(R_INFO)(sym_index, R_X86_64_PC32);
1436 break;
1437 }
1438
1439 if (!s1->got) {
1440 build_got(s1);
1441 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1442 }
1443 if (type == R_X86_64_GOT32 || type == R_X86_64_GOTPCREL ||
1444 type == R_X86_64_PLT32 || type == 41 || type == 42) {
1445 unsigned long ofs;
1446 /* look at the symbol got offset. If none, then add one */
1447 if (type == R_X86_64_PLT32)
1448 reloc_type = R_X86_64_JUMP_SLOT;
1449 else
1450 reloc_type = R_X86_64_GLOB_DAT;
1451 ofs = put_got_entry(s1, reloc_type, sym->st_size,
1452 sym->st_info, sym_index);
1453 if (type == R_X86_64_PLT32)
1454 /* We store the place of the generated PLT slot
1455 in our addend. */
1456 rel->r_addend += ofs;
1457 }
1458 break;
1459 #else
1460 #error unsupported CPU
1461 #endif
1462 default:
1463 break;
1464 }
1465 }
1466 }
1467 }
1468
1469 ST_FUNC Section *new_symtab(TCCState *s1,
1470 const char *symtab_name, int sh_type, int sh_flags,
1471 const char *strtab_name,
1472 const char *hash_name, int hash_sh_flags)
1473 {
1474 Section *symtab, *strtab, *hash;
1475 int *ptr, nb_buckets;
1476
1477 symtab = new_section(s1, symtab_name, sh_type, sh_flags);
1478 symtab->sh_entsize = sizeof(ElfW(Sym));
1479 strtab = new_section(s1, strtab_name, SHT_STRTAB, sh_flags);
1480 put_elf_str(strtab, "");
1481 symtab->link = strtab;
1482 put_elf_sym(symtab, 0, 0, 0, 0, 0, NULL);
1483
1484 nb_buckets = 1;
1485
1486 hash = new_section(s1, hash_name, SHT_HASH, hash_sh_flags);
1487 hash->sh_entsize = sizeof(int);
1488 symtab->hash = hash;
1489 hash->link = symtab;
1490
1491 ptr = section_ptr_add(hash, (2 + nb_buckets + 1) * sizeof(int));
1492 ptr[0] = nb_buckets;
1493 ptr[1] = 1;
1494 memset(ptr + 2, 0, (nb_buckets + 1) * sizeof(int));
1495 return symtab;
1496 }
1497
1498 /* put dynamic tag */
1499 static void put_dt(Section *dynamic, int dt, addr_t val)
1500 {
1501 ElfW(Dyn) *dyn;
1502 dyn = section_ptr_add(dynamic, sizeof(ElfW(Dyn)));
1503 dyn->d_tag = dt;
1504 dyn->d_un.d_val = val;
1505 }
1506
1507 static void add_init_array_defines(TCCState *s1, const char *section_name)
1508 {
1509 Section *s;
1510 long end_offset;
1511 char sym_start[1024];
1512 char sym_end[1024];
1513
1514 snprintf(sym_start, sizeof(sym_start), "__%s_start", section_name + 1);
1515 snprintf(sym_end, sizeof(sym_end), "__%s_end", section_name + 1);
1516
1517 s = find_section(s1, section_name);
1518 if (!s) {
1519 end_offset = 0;
1520 s = data_section;
1521 } else {
1522 end_offset = s->data_offset;
1523 }
1524
1525 add_elf_sym(symtab_section,
1526 0, 0,
1527 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1528 s->sh_num, sym_start);
1529 add_elf_sym(symtab_section,
1530 end_offset, 0,
1531 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1532 s->sh_num, sym_end);
1533 }
1534
1535 static int tcc_add_support(TCCState *s1, const char *filename)
1536 {
1537 char buf[1024];
1538 snprintf(buf, sizeof(buf), "%s/%s/%s", s1->tcc_lib_path,
1539 /* an cpu specific path inside tcc_lib_path, mainly for keeping libtcc1.a */
1540 #ifdef TCC_TARGET_I386
1541 "i386"
1542 #endif
1543 #ifdef TCC_TARGET_X86_64
1544 "x86-64"
1545 #endif
1546 #ifdef TCC_TARGET_ARM
1547 "arm"
1548 #endif
1549 #ifdef TCC_TARGET_ARM64
1550 "arm64"
1551 #endif
1552 #ifdef TCC_TARGET_C67
1553 "C67"
1554 #endif
1555 ,filename);
1556
1557 return tcc_add_file(s1, buf, TCC_FILETYPE_BINARY);
1558 }
1559
1560 ST_FUNC void tcc_add_bcheck(TCCState *s1)
1561 {
1562 #ifdef CONFIG_TCC_BCHECK
1563 addr_t *ptr;
1564
1565 if (0 == s1->do_bounds_check)
1566 return;
1567
1568 /* XXX: add an object file to do that */
1569 ptr = section_ptr_add(bounds_section, sizeof(*ptr));
1570 *ptr = 0;
1571 add_elf_sym(symtab_section, 0, 0,
1572 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1573 bounds_section->sh_num, "__bounds_start");
1574 if (s1->output_type != TCC_OUTPUT_MEMORY) {
1575 /* add 'call __bound_init()' in .init section */
1576
1577 /* XXX not called on MSYS, reason is unknown. For this
1578 case a call to __bound_init is performed in bcheck.c
1579 when __bound_ptr_add, __bound_new_region,
1580 __bound_delete_region called */
1581
1582 int sym_index = find_elf_sym(symtab_section, "__bound_init");
1583 if (sym_index) {
1584 Section *init_section = find_section(s1, ".init");
1585 unsigned char *pinit = section_ptr_add(init_section, 5);
1586 pinit[0] = 0xe8;
1587 write32le(pinit + 1, -4);
1588 put_elf_reloc(symtab_section, init_section,
1589 init_section->data_offset - 4, R_386_PC32, sym_index);
1590 }
1591 else
1592 tcc_warning("__bound_init not defined");
1593 }
1594 #endif
1595 }
1596
1597 /* add tcc runtime libraries */
1598 ST_FUNC void tcc_add_runtime(TCCState *s1)
1599 {
1600 tcc_add_pragma_libs(s1);
1601
1602 /* add libc */
1603 if (!s1->nostdlib) {
1604 tcc_add_library(s1, "c");
1605 #ifdef CONFIG_USE_LIBGCC
1606 if (!s1->static_link) {
1607 tcc_add_file(s1, TCC_LIBGCC, TCC_FILETYPE_BINARY);
1608 }
1609 #endif
1610 tcc_add_support(s1, "libtcc1.a");
1611 }
1612
1613 /* tcc_add_bcheck tries to relocate a call to __bound_init in _init so
1614 libtcc1.a must be loaded before for __bound_init to be defined and
1615 crtn.o must be loaded after to not finalize _init too early. */
1616 tcc_add_bcheck(s1);
1617
1618 if (!s1->nostdlib) {
1619 /* add crt end if not memory output */
1620 if (s1->output_type != TCC_OUTPUT_MEMORY)
1621 tcc_add_crt(s1, "crtn.o");
1622 }
1623 }
1624
1625 /* add various standard linker symbols (must be done after the
1626 sections are filled (for example after allocating common
1627 symbols)) */
1628 ST_FUNC void tcc_add_linker_symbols(TCCState *s1)
1629 {
1630 char buf[1024];
1631 int i;
1632 Section *s;
1633
1634 add_elf_sym(symtab_section,
1635 text_section->data_offset, 0,
1636 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1637 text_section->sh_num, "_etext");
1638 add_elf_sym(symtab_section,
1639 data_section->data_offset, 0,
1640 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1641 data_section->sh_num, "_edata");
1642 add_elf_sym(symtab_section,
1643 bss_section->data_offset, 0,
1644 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1645 bss_section->sh_num, "_end");
1646 /* horrible new standard ldscript defines */
1647 add_init_array_defines(s1, ".preinit_array");
1648 add_init_array_defines(s1, ".init_array");
1649 add_init_array_defines(s1, ".fini_array");
1650
1651 /* add start and stop symbols for sections whose name can be
1652 expressed in C */
1653 for(i = 1; i < s1->nb_sections; i++) {
1654 s = s1->sections[i];
1655 if (s->sh_type == SHT_PROGBITS &&
1656 (s->sh_flags & SHF_ALLOC)) {
1657 const char *p;
1658 int ch;
1659
1660 /* check if section name can be expressed in C */
1661 p = s->name;
1662 for(;;) {
1663 ch = *p;
1664 if (!ch)
1665 break;
1666 if (!isid(ch) && !isnum(ch))
1667 goto next_sec;
1668 p++;
1669 }
1670 snprintf(buf, sizeof(buf), "__start_%s", s->name);
1671 add_elf_sym(symtab_section,
1672 0, 0,
1673 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1674 s->sh_num, buf);
1675 snprintf(buf, sizeof(buf), "__stop_%s", s->name);
1676 add_elf_sym(symtab_section,
1677 s->data_offset, 0,
1678 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1679 s->sh_num, buf);
1680 }
1681 next_sec: ;
1682 }
1683 }
1684
1685 static void tcc_output_binary(TCCState *s1, FILE *f,
1686 const int *sec_order)
1687 {
1688 Section *s;
1689 int i, offset, size;
1690
1691 offset = 0;
1692 for(i=1;i<s1->nb_sections;i++) {
1693 s = s1->sections[sec_order[i]];
1694 if (s->sh_type != SHT_NOBITS &&
1695 (s->sh_flags & SHF_ALLOC)) {
1696 while (offset < s->sh_offset) {
1697 fputc(0, f);
1698 offset++;
1699 }
1700 size = s->sh_size;
1701 fwrite(s->data, 1, size, f);
1702 offset += size;
1703 }
1704 }
1705 }
1706
1707 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1708 #define HAVE_PHDR 1
1709 #define EXTRA_RELITEMS 14
1710
1711 /* move the relocation value from .dynsym to .got */
1712 void patch_dynsym_undef(TCCState *s1, Section *s)
1713 {
1714 uint32_t *gotd = (void *)s1->got->data;
1715 ElfW(Sym) *sym;
1716
1717 gotd += 3; /* dummy entries in .got */
1718 /* relocate symbols in .dynsym */
1719 for_each_elem(s, 1, sym, ElfW(Sym)) {
1720 if (sym->st_shndx == SHN_UNDEF) {
1721 *gotd++ = sym->st_value + 6; /* XXX 6 is magic ? */
1722 sym->st_value = 0;
1723 }
1724 }
1725 }
1726 #else
1727 #define HAVE_PHDR 1
1728 #define EXTRA_RELITEMS 9
1729
1730 /* zero plt offsets of weak symbols in .dynsym */
1731 void patch_dynsym_undef(TCCState *s1, Section *s)
1732 {
1733 ElfW(Sym) *sym;
1734
1735 for_each_elem(s, 1, sym, ElfW(Sym))
1736 if (sym->st_shndx == SHN_UNDEF && ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
1737 sym->st_value = 0;
1738 }
1739 #endif
1740
1741 ST_FUNC void fill_got_entry(TCCState *s1, ElfW_Rel *rel)
1742 {
1743 int sym_index = ELFW(R_SYM) (rel->r_info);
1744 ElfW(Sym) *sym = &((ElfW(Sym) *) symtab_section->data)[sym_index];
1745 unsigned long offset;
1746
1747 if (sym_index >= s1->nb_sym_attrs)
1748 return;
1749 offset = s1->sym_attrs[sym_index].got_offset;
1750 section_reserve(s1->got, offset + PTR_SIZE);
1751 #ifdef TCC_TARGET_X86_64
1752 /* only works for x86-64 */
1753 write32le(s1->got->data + offset + 4, sym->st_value >> 32);
1754 #endif
1755 write32le(s1->got->data + offset, sym->st_value & 0xffffffff);
1756 }
1757
1758 /* Perform relocation to GOT or PLT entries */
1759 ST_FUNC void fill_got(TCCState *s1)
1760 {
1761 Section *s;
1762 ElfW_Rel *rel;
1763 int i;
1764
1765 for(i = 1; i < s1->nb_sections; i++) {
1766 s = s1->sections[i];
1767 if (s->sh_type != SHT_RELX)
1768 continue;
1769 /* no need to handle got relocations */
1770 if (s->link != symtab_section)
1771 continue;
1772 for_each_elem(s, 0, rel, ElfW_Rel) {
1773 switch (ELFW(R_TYPE) (rel->r_info)) {
1774 case R_X86_64_GOT32:
1775 case R_X86_64_GOTPCREL:
1776 case 41 /* R_X86_64_GOTPCRELX */:
1777 case 42 /* R_X86_64_REX_GOTPCRELX */:
1778 case R_X86_64_PLT32:
1779 fill_got_entry(s1, rel);
1780 break;
1781 }
1782 }
1783 }
1784 }
1785
1786 /* Bind symbols of executable: resolve undefined symbols from exported symbols
1787 in shared libraries and export non local defined symbols to shared libraries
1788 if -rdynamic switch was given on command line */
1789 static void bind_exe_dynsyms(TCCState *s1)
1790 {
1791 const char *name;
1792 int sym_index, index;
1793 ElfW(Sym) *sym, *esym;
1794 int type;
1795
1796 /* Resolve undefined symbols from dynamic symbols. When there is a match:
1797 - if STT_FUNC or STT_GNU_IFUNC symbol -> add it in PLT
1798 - if STT_OBJECT symbol -> add it in .bss section with suitable reloc */
1799 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
1800 if (sym->st_shndx == SHN_UNDEF) {
1801 name = (char *) symtab_section->link->data + sym->st_name;
1802 sym_index = find_elf_sym(s1->dynsymtab_section, name);
1803 if (sym_index) {
1804 esym = &((ElfW(Sym) *)s1->dynsymtab_section->data)[sym_index];
1805 type = ELFW(ST_TYPE)(esym->st_info);
1806 if ((type == STT_FUNC) || (type == STT_GNU_IFUNC)) {
1807 /* Indirect functions shall have STT_FUNC type in executable
1808 * dynsym section. Indeed, a dlsym call following a lazy
1809 * resolution would pick the symbol value from the
1810 * executable dynsym entry which would contain the address
1811 * of the function wanted by the caller of dlsym instead of
1812 * the address of the function that would return that
1813 * address */
1814 put_got_entry(s1, R_JMP_SLOT, esym->st_size,
1815 ELFW(ST_INFO)(STB_GLOBAL,STT_FUNC),
1816 sym - (ElfW(Sym) *)symtab_section->data);
1817 } else if (type == STT_OBJECT) {
1818 unsigned long offset;
1819 ElfW(Sym) *dynsym;
1820 offset = bss_section->data_offset;
1821 /* XXX: which alignment ? */
1822 offset = (offset + 16 - 1) & -16;
1823 index = put_elf_sym(s1->dynsym, offset, esym->st_size,
1824 esym->st_info, 0, bss_section->sh_num,
1825 name);
1826 /* Ensure R_COPY works for weak symbol aliases */
1827 if (ELFW(ST_BIND)(esym->st_info) == STB_WEAK) {
1828 for_each_elem(s1->dynsymtab_section, 1, dynsym, ElfW(Sym)) {
1829 if ((dynsym->st_value == esym->st_value)
1830 && (ELFW(ST_BIND)(dynsym->st_info) == STB_GLOBAL)) {
1831 char *dynname = (char *) s1->dynsymtab_section->link->data
1832 + dynsym->st_name;
1833 put_elf_sym(s1->dynsym, offset, dynsym->st_size,
1834 dynsym->st_info, 0,
1835 bss_section->sh_num, dynname);
1836 break;
1837 }
1838 }
1839 }
1840 put_elf_reloc(s1->dynsym, bss_section,
1841 offset, R_COPY, index);
1842 offset += esym->st_size;
1843 bss_section->data_offset = offset;
1844 }
1845 } else {
1846 /* STB_WEAK undefined symbols are accepted */
1847 /* XXX: _fp_hw seems to be part of the ABI, so we ignore it */
1848 if (ELFW(ST_BIND)(sym->st_info) == STB_WEAK ||
1849 !strcmp(name, "_fp_hw")) {
1850 } else {
1851 tcc_error_noabort("undefined symbol '%s'", name);
1852 }
1853 }
1854 } else if (s1->rdynamic && ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
1855 /* if -rdynamic option, then export all non local symbols */
1856 name = (char *) symtab_section->link->data + sym->st_name;
1857 put_elf_sym(s1->dynsym, sym->st_value, sym->st_size, sym->st_info,
1858 0, sym->st_shndx, name);
1859 }
1860 }
1861 }
1862
1863 /* Bind symbols of libraries: export non local symbols of executable that
1864 resolve undefined symbols of shared libraries */
1865 static void bind_libs_dynsyms(TCCState *s1)
1866 {
1867 const char *name;
1868 int sym_index;
1869 ElfW(Sym) *sym, *esym;
1870
1871 /* now look at unresolved dynamic symbols and export
1872 corresponding symbol */
1873 for_each_elem(s1->dynsymtab_section, 1, esym, ElfW(Sym)) {
1874 name = (char *) s1->dynsymtab_section->link->data + esym->st_name;
1875 sym_index = find_elf_sym(symtab_section, name);
1876 if (sym_index) {
1877 /* XXX: avoid adding a symbol if already present because of
1878 -rdynamic ? */
1879 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1880 if (sym->st_shndx != SHN_UNDEF)
1881 put_elf_sym(s1->dynsym, sym->st_value, sym->st_size,
1882 sym->st_info, 0, sym->st_shndx, name);
1883 } else if (esym->st_shndx == SHN_UNDEF) {
1884 /* weak symbols can stay undefined */
1885 if (ELFW(ST_BIND)(esym->st_info) != STB_WEAK)
1886 tcc_warning("undefined dynamic symbol '%s'", name);
1887 }
1888 }
1889 }
1890
1891 /* Export all non local symbols (for shared libraries) */
1892 static void export_global_syms(TCCState *s1)
1893 {
1894 int nb_syms, dynindex, index;
1895 const char *name;
1896 ElfW(Sym) *sym;
1897
1898 nb_syms = symtab_section->data_offset / sizeof(ElfW(Sym));
1899 s1->symtab_to_dynsym = tcc_mallocz(sizeof(int) * nb_syms);
1900 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
1901 if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
1902 name = (char *) symtab_section->link->data + sym->st_name;
1903 dynindex = put_elf_sym(s1->dynsym, sym->st_value, sym->st_size,
1904 sym->st_info, 0, sym->st_shndx, name);
1905 index = sym - (ElfW(Sym) *) symtab_section->data;
1906 s1->symtab_to_dynsym[index] = dynindex;
1907 }
1908 }
1909 }
1910
1911 /* relocate the PLT: compute addresses and offsets in the PLT now that final
1912 address for PLT and GOT are known (see fill_program_header) */
1913 ST_FUNC void relocate_plt(TCCState *s1)
1914 {
1915 uint8_t *p, *p_end;
1916
1917 if (!s1->plt)
1918 return;
1919
1920 p = s1->plt->data;
1921 p_end = p + s1->plt->data_offset;
1922 if (p < p_end) {
1923 #if defined(TCC_TARGET_I386)
1924 write32le(p + 2, read32le(p + 2) + s1->got->sh_addr);
1925 write32le(p + 8, read32le(p + 8) + s1->got->sh_addr);
1926 p += 16;
1927 while (p < p_end) {
1928 write32le(p + 2, read32le(p + 2) + s1->got->sh_addr);
1929 p += 16;
1930 }
1931 #elif defined(TCC_TARGET_X86_64)
1932 int x = s1->got->sh_addr - s1->plt->sh_addr - 6;
1933 write32le(p + 2, read32le(p + 2) + x);
1934 write32le(p + 8, read32le(p + 8) + x - 6);
1935 p += 16;
1936 while (p < p_end) {
1937 write32le(p + 2, read32le(p + 2) + x + s1->plt->data - p);
1938 p += 16;
1939 }
1940 #elif defined(TCC_TARGET_ARM)
1941 int x;
1942 x=s1->got->sh_addr - s1->plt->sh_addr - 12;
1943 p += 16;
1944 while (p < p_end) {
1945 if (read32le(p) == 0x46c04778) /* PLT Thumb stub present */
1946 p += 4;
1947 write32le(p + 12, x + read32le(p + 12) + s1->plt->data - p);
1948 p += 16;
1949 }
1950 #elif defined(TCC_TARGET_ARM64)
1951 uint64_t plt = s1->plt->sh_addr;
1952 uint64_t got = s1->got->sh_addr;
1953 uint64_t off = (got >> 12) - (plt >> 12);
1954 if ((off + ((uint32_t)1 << 20)) >> 21)
1955 tcc_error("Failed relocating PLT (off=0x%lx, got=0x%lx, plt=0x%lx)", off, got, plt);
1956 write32le(p, 0xa9bf7bf0); // stp x16,x30,[sp,#-16]!
1957 write32le(p + 4, (0x90000010 | // adrp x16,...
1958 (off & 0x1ffffc) << 3 | (off & 3) << 29));
1959 write32le(p + 8, (0xf9400211 | // ldr x17,[x16,#...]
1960 (got & 0xff8) << 7));
1961 write32le(p + 12, (0x91000210 | // add x16,x16,#...
1962 (got & 0xfff) << 10));
1963 write32le(p + 16, 0xd61f0220); // br x17
1964 write32le(p + 20, 0xd503201f); // nop
1965 write32le(p + 24, 0xd503201f); // nop
1966 write32le(p + 28, 0xd503201f); // nop
1967 p += 32;
1968 while (p < p_end) {
1969 uint64_t pc = plt + (p - s1->plt->data);
1970 uint64_t addr = got + read64le(p);
1971 uint64_t off = (addr >> 12) - (pc >> 12);
1972 if ((off + ((uint32_t)1 << 20)) >> 21)
1973 tcc_error("Failed relocating PLT (off=0x%lx, addr=0x%lx, pc=0x%lx)", off, addr, pc);
1974 write32le(p, (0x90000010 | // adrp x16,...
1975 (off & 0x1ffffc) << 3 | (off & 3) << 29));
1976 write32le(p + 4, (0xf9400211 | // ldr x17,[x16,#...]
1977 (addr & 0xff8) << 7));
1978 write32le(p + 8, (0x91000210 | // add x16,x16,#...
1979 (addr & 0xfff) << 10));
1980 write32le(p + 12, 0xd61f0220); // br x17
1981 p += 16;
1982 }
1983 #elif defined(TCC_TARGET_C67)
1984 /* XXX: TODO */
1985 #else
1986 #error unsupported CPU
1987 #endif
1988 }
1989 }
1990
1991 /* Allocate strings for section names and decide if an unallocated section
1992 should be output.
1993
1994 NOTE: the strsec section comes last, so its size is also correct ! */
1995 static void alloc_sec_names(TCCState *s1, int file_type, Section *strsec)
1996 {
1997 int i;
1998 Section *s;
1999
2000 /* Allocate strings for section names */
2001 for(i = 1; i < s1->nb_sections; i++) {
2002 s = s1->sections[i];
2003 s->sh_name = put_elf_str(strsec, s->name);
2004 /* when generating a DLL, we include relocations but we may
2005 patch them */
2006 if (file_type == TCC_OUTPUT_DLL &&
2007 s->sh_type == SHT_RELX &&
2008 !(s->sh_flags & SHF_ALLOC)) {
2009 /* gr: avoid bogus relocs for empty (debug) sections */
2010 if (s1->sections[s->sh_info]->sh_flags & SHF_ALLOC)
2011 prepare_dynamic_rel(s1, s);
2012 else if (s1->do_debug)
2013 s->sh_size = s->data_offset;
2014 } else if (s1->do_debug ||
2015 file_type == TCC_OUTPUT_OBJ ||
2016 file_type == TCC_OUTPUT_EXE ||
2017 (s->sh_flags & SHF_ALLOC) ||
2018 i == (s1->nb_sections - 1)) {
2019 /* we output all sections if debug or object file */
2020 s->sh_size = s->data_offset;
2021 }
2022 }
2023 }
2024
2025 /* Info to be copied in dynamic section */
2026 struct dyn_inf {
2027 Section *dynamic;
2028 Section *dynstr;
2029 unsigned long dyn_rel_off;
2030 addr_t rel_addr;
2031 addr_t rel_size;
2032 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2033 addr_t bss_addr;
2034 addr_t bss_size;
2035 #endif
2036 };
2037
2038 /* Assign sections to segments and decide how are sections laid out when loaded
2039 in memory. This function also fills corresponding program headers. */
2040 static int layout_sections(TCCState *s1, ElfW(Phdr) *phdr, int phnum,
2041 Section *interp, Section* strsec,
2042 struct dyn_inf *dyninf, int *sec_order)
2043 {
2044 int i, j, k, file_type, sh_order_index, file_offset;
2045 unsigned long s_align;
2046 long long tmp;
2047 addr_t addr;
2048 ElfW(Phdr) *ph;
2049 Section *s;
2050
2051 file_type = s1->output_type;
2052 sh_order_index = 1;
2053 file_offset = 0;
2054 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF)
2055 file_offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr));
2056 s_align = ELF_PAGE_SIZE;
2057 if (s1->section_align)
2058 s_align = s1->section_align;
2059
2060 if (phnum > 0) {
2061 if (s1->has_text_addr) {
2062 int a_offset, p_offset;
2063 addr = s1->text_addr;
2064 /* we ensure that (addr % ELF_PAGE_SIZE) == file_offset %
2065 ELF_PAGE_SIZE */
2066 a_offset = (int) (addr & (s_align - 1));
2067 p_offset = file_offset & (s_align - 1);
2068 if (a_offset < p_offset)
2069 a_offset += s_align;
2070 file_offset += (a_offset - p_offset);
2071 } else {
2072 if (file_type == TCC_OUTPUT_DLL)
2073 addr = 0;
2074 else
2075 addr = ELF_START_ADDR;
2076 /* compute address after headers */
2077 addr += (file_offset & (s_align - 1));
2078 }
2079
2080 ph = &phdr[0];
2081 /* Leave one program headers for the program interpreter and one for
2082 the program header table itself if needed. These are done later as
2083 they require section layout to be done first. */
2084 if (interp)
2085 ph += 1 + HAVE_PHDR;
2086
2087 /* dynamic relocation table information, for .dynamic section */
2088 dyninf->rel_addr = dyninf->rel_size = 0;
2089 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2090 dyninf->bss_addr = dyninf->bss_size = 0;
2091 #endif
2092
2093 for(j = 0; j < 2; j++) {
2094 ph->p_type = PT_LOAD;
2095 if (j == 0)
2096 ph->p_flags = PF_R | PF_X;
2097 else
2098 ph->p_flags = PF_R | PF_W;
2099 ph->p_align = s_align;
2100
2101 /* Decide the layout of sections loaded in memory. This must
2102 be done before program headers are filled since they contain
2103 info about the layout. We do the following ordering: interp,
2104 symbol tables, relocations, progbits, nobits */
2105 /* XXX: do faster and simpler sorting */
2106 for(k = 0; k < 5; k++) {
2107 for(i = 1; i < s1->nb_sections; i++) {
2108 s = s1->sections[i];
2109 /* compute if section should be included */
2110 if (j == 0) {
2111 if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) !=
2112 SHF_ALLOC)
2113 continue;
2114 } else {
2115 if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) !=
2116 (SHF_ALLOC | SHF_WRITE))
2117 continue;
2118 }
2119 if (s == interp) {
2120 if (k != 0)
2121 continue;
2122 } else if (s->sh_type == SHT_DYNSYM ||
2123 s->sh_type == SHT_STRTAB ||
2124 s->sh_type == SHT_HASH) {
2125 if (k != 1)
2126 continue;
2127 } else if (s->sh_type == SHT_RELX) {
2128 if (k != 2)
2129 continue;
2130 } else if (s->sh_type == SHT_NOBITS) {
2131 if (k != 4)
2132 continue;
2133 } else {
2134 if (k != 3)
2135 continue;
2136 }
2137 sec_order[sh_order_index++] = i;
2138
2139 /* section matches: we align it and add its size */
2140 tmp = addr;
2141 addr = (addr + s->sh_addralign - 1) &
2142 ~(s->sh_addralign - 1);
2143 file_offset += (int) ( addr - tmp );
2144 s->sh_offset = file_offset;
2145 s->sh_addr = addr;
2146
2147 /* update program header infos */
2148 if (ph->p_offset == 0) {
2149 ph->p_offset = file_offset;
2150 ph->p_vaddr = addr;
2151 ph->p_paddr = ph->p_vaddr;
2152 }
2153 /* update dynamic relocation infos */
2154 if (s->sh_type == SHT_RELX) {
2155 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2156 if (!strcmp(strsec->data + s->sh_name, ".rel.got")) {
2157 dyninf->rel_addr = addr;
2158 dyninf->rel_size += s->sh_size; /* XXX only first rel. */
2159 }
2160 if (!strcmp(strsec->data + s->sh_name, ".rel.bss")) {
2161 dyninf->bss_addr = addr;
2162 dyninf->bss_size = s->sh_size; /* XXX only first rel. */
2163 }
2164 #else
2165 if (dyninf->rel_size == 0)
2166 dyninf->rel_addr = addr;
2167 dyninf->rel_size += s->sh_size;
2168 #endif
2169 }
2170 addr += s->sh_size;
2171 if (s->sh_type != SHT_NOBITS)
2172 file_offset += s->sh_size;
2173 }
2174 }
2175 if (j == 0) {
2176 /* Make the first PT_LOAD segment include the program
2177 headers itself (and the ELF header as well), it'll
2178 come out with same memory use but will make various
2179 tools like binutils strip work better. */
2180 ph->p_offset &= ~(ph->p_align - 1);
2181 ph->p_vaddr &= ~(ph->p_align - 1);
2182 ph->p_paddr &= ~(ph->p_align - 1);
2183 }
2184 ph->p_filesz = file_offset - ph->p_offset;
2185 ph->p_memsz = addr - ph->p_vaddr;
2186 ph++;
2187 if (j == 0) {
2188 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF) {
2189 /* if in the middle of a page, we duplicate the page in
2190 memory so that one copy is RX and the other is RW */
2191 if ((addr & (s_align - 1)) != 0)
2192 addr += s_align;
2193 } else {
2194 addr = (addr + s_align - 1) & ~(s_align - 1);
2195 file_offset = (file_offset + s_align - 1) & ~(s_align - 1);
2196 }
2197 }
2198 }
2199 }
2200
2201 /* all other sections come after */
2202 for(i = 1; i < s1->nb_sections; i++) {
2203 s = s1->sections[i];
2204 if (phnum > 0 && (s->sh_flags & SHF_ALLOC))
2205 continue;
2206 sec_order[sh_order_index++] = i;
2207
2208 file_offset = (file_offset + s->sh_addralign - 1) &
2209 ~(s->sh_addralign - 1);
2210 s->sh_offset = file_offset;
2211 if (s->sh_type != SHT_NOBITS)
2212 file_offset += s->sh_size;
2213 }
2214
2215 return file_offset;
2216 }
2217
2218 static void fill_unloadable_phdr(ElfW(Phdr) *phdr, int phnum, Section *interp,
2219 Section *dynamic)
2220 {
2221 ElfW(Phdr) *ph;
2222
2223 /* if interpreter, then add corresponding program header */
2224 if (interp) {
2225 ph = &phdr[0];
2226
2227 if (HAVE_PHDR)
2228 {
2229 int len = phnum * sizeof(ElfW(Phdr));
2230
2231 ph->p_type = PT_PHDR;
2232 ph->p_offset = sizeof(ElfW(Ehdr));
2233 ph->p_vaddr = interp->sh_addr - len;
2234 ph->p_paddr = ph->p_vaddr;
2235 ph->p_filesz = ph->p_memsz = len;
2236 ph->p_flags = PF_R | PF_X;
2237 ph->p_align = 4; /* interp->sh_addralign; */
2238 ph++;
2239 }
2240
2241 ph->p_type = PT_INTERP;
2242 ph->p_offset = interp->sh_offset;
2243 ph->p_vaddr = interp->sh_addr;
2244 ph->p_paddr = ph->p_vaddr;
2245 ph->p_filesz = interp->sh_size;
2246 ph->p_memsz = interp->sh_size;
2247 ph->p_flags = PF_R;
2248 ph->p_align = interp->sh_addralign;
2249 }
2250
2251 /* if dynamic section, then add corresponding program header */
2252 if (dynamic) {
2253 ph = &phdr[phnum - 1];
2254
2255 ph->p_type = PT_DYNAMIC;
2256 ph->p_offset = dynamic->sh_offset;
2257 ph->p_vaddr = dynamic->sh_addr;
2258 ph->p_paddr = ph->p_vaddr;
2259 ph->p_filesz = dynamic->sh_size;
2260 ph->p_memsz = dynamic->sh_size;
2261 ph->p_flags = PF_R | PF_W;
2262 ph->p_align = dynamic->sh_addralign;
2263 }
2264 }
2265
2266 /* Fill the dynamic section with tags describing the address and size of
2267 sections */
2268 static void fill_dynamic(TCCState *s1, struct dyn_inf *dyninf)
2269 {
2270 Section *dynamic;
2271
2272 dynamic = dyninf->dynamic;
2273
2274 /* put dynamic section entries */
2275 dynamic->data_offset = dyninf->dyn_rel_off;
2276 put_dt(dynamic, DT_HASH, s1->dynsym->hash->sh_addr);
2277 put_dt(dynamic, DT_STRTAB, dyninf->dynstr->sh_addr);
2278 put_dt(dynamic, DT_SYMTAB, s1->dynsym->sh_addr);
2279 put_dt(dynamic, DT_STRSZ, dyninf->dynstr->data_offset);
2280 put_dt(dynamic, DT_SYMENT, sizeof(ElfW(Sym)));
2281 #if defined(TCC_TARGET_ARM64) || defined(TCC_TARGET_X86_64)
2282 put_dt(dynamic, DT_RELA, dyninf->rel_addr);
2283 put_dt(dynamic, DT_RELASZ, dyninf->rel_size);
2284 put_dt(dynamic, DT_RELAENT, sizeof(ElfW_Rel));
2285 #else
2286 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2287 put_dt(dynamic, DT_PLTGOT, s1->got->sh_addr);
2288 put_dt(dynamic, DT_PLTRELSZ, dyninf->rel_size);
2289 put_dt(dynamic, DT_JMPREL, dyninf->rel_addr);
2290 put_dt(dynamic, DT_PLTREL, DT_REL);
2291 put_dt(dynamic, DT_REL, dyninf->bss_addr);
2292 put_dt(dynamic, DT_RELSZ, dyninf->bss_size);
2293 #else
2294 put_dt(dynamic, DT_REL, dyninf->rel_addr);
2295 put_dt(dynamic, DT_RELSZ, dyninf->rel_size);
2296 put_dt(dynamic, DT_RELENT, sizeof(ElfW_Rel));
2297 #endif
2298 #endif
2299 if (s1->do_debug)
2300 put_dt(dynamic, DT_DEBUG, 0);
2301 put_dt(dynamic, DT_NULL, 0);
2302 }
2303
2304 /* Relocate remaining sections and symbols (that is those not related to
2305 dynamic linking) */
2306 static int final_sections_reloc(TCCState *s1)
2307 {
2308 int i;
2309 Section *s;
2310
2311 relocate_syms(s1, 0);
2312
2313 if (s1->nb_errors != 0)
2314 return -1;
2315
2316 /* relocate sections */
2317 /* XXX: ignore sections with allocated relocations ? */
2318 for(i = 1; i < s1->nb_sections; i++) {
2319 s = s1->sections[i];
2320 #ifdef TCC_TARGET_I386
2321 if (s->reloc && s != s1->got && (s->sh_flags & SHF_ALLOC)) //gr
2322 /* On X86 gdb 7.3 works in any case but gdb 6.6 will crash if SHF_ALLOC
2323 checking is removed */
2324 #else
2325 if (s->reloc && s != s1->got)
2326 /* On X86_64 gdb 7.3 will crash if SHF_ALLOC checking is present */
2327 #endif
2328 relocate_section(s1, s);
2329 }
2330
2331 /* relocate relocation entries if the relocation tables are
2332 allocated in the executable */
2333 for(i = 1; i < s1->nb_sections; i++) {
2334 s = s1->sections[i];
2335 if ((s->sh_flags & SHF_ALLOC) &&
2336 s->sh_type == SHT_RELX) {
2337 relocate_rel(s1, s);
2338 }
2339 }
2340 return 0;
2341 }
2342
2343 /* Create an ELF file on disk.
2344 This function handle ELF specific layout requirements */
2345 static void tcc_output_elf(TCCState *s1, FILE *f, int phnum, ElfW(Phdr) *phdr,
2346 int file_offset, int *sec_order)
2347 {
2348 int i, shnum, offset, size, file_type;
2349 Section *s;
2350 ElfW(Ehdr) ehdr;
2351 ElfW(Shdr) shdr, *sh;
2352
2353 file_type = s1->output_type;
2354 shnum = s1->nb_sections;
2355
2356 memset(&ehdr, 0, sizeof(ehdr));
2357
2358 if (phnum > 0) {
2359 ehdr.e_phentsize = sizeof(ElfW(Phdr));
2360 ehdr.e_phnum = phnum;
2361 ehdr.e_phoff = sizeof(ElfW(Ehdr));
2362 }
2363
2364 /* align to 4 */
2365 file_offset = (file_offset + 3) & -4;
2366
2367 /* fill header */
2368 ehdr.e_ident[0] = ELFMAG0;
2369 ehdr.e_ident[1] = ELFMAG1;
2370 ehdr.e_ident[2] = ELFMAG2;
2371 ehdr.e_ident[3] = ELFMAG3;
2372 ehdr.e_ident[4] = ELFCLASSW;
2373 ehdr.e_ident[5] = ELFDATA2LSB;
2374 ehdr.e_ident[6] = EV_CURRENT;
2375 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2376 ehdr.e_ident[EI_OSABI] = ELFOSABI_FREEBSD;
2377 #endif
2378 #ifdef TCC_TARGET_ARM
2379 #ifdef TCC_ARM_EABI
2380 ehdr.e_ident[EI_OSABI] = 0;
2381 ehdr.e_flags = EF_ARM_EABI_VER4;
2382 if (file_type == TCC_OUTPUT_EXE || file_type == TCC_OUTPUT_DLL)
2383 ehdr.e_flags |= EF_ARM_HASENTRY;
2384 if (s1->float_abi == ARM_HARD_FLOAT)
2385 ehdr.e_flags |= EF_ARM_VFP_FLOAT;
2386 else
2387 ehdr.e_flags |= EF_ARM_SOFT_FLOAT;
2388 #else
2389 ehdr.e_ident[EI_OSABI] = ELFOSABI_ARM;
2390 #endif
2391 #endif
2392 switch(file_type) {
2393 default:
2394 case TCC_OUTPUT_EXE:
2395 ehdr.e_type = ET_EXEC;
2396 ehdr.e_entry = get_elf_sym_addr(s1, "_start", 1);
2397 break;
2398 case TCC_OUTPUT_DLL:
2399 ehdr.e_type = ET_DYN;
2400 ehdr.e_entry = text_section->sh_addr; /* XXX: is it correct ? */
2401 break;
2402 case TCC_OUTPUT_OBJ:
2403 ehdr.e_type = ET_REL;
2404 break;
2405 }
2406 ehdr.e_machine = EM_TCC_TARGET;
2407 ehdr.e_version = EV_CURRENT;
2408 ehdr.e_shoff = file_offset;
2409 ehdr.e_ehsize = sizeof(ElfW(Ehdr));
2410 ehdr.e_shentsize = sizeof(ElfW(Shdr));
2411 ehdr.e_shnum = shnum;
2412 ehdr.e_shstrndx = shnum - 1;
2413
2414 fwrite(&ehdr, 1, sizeof(ElfW(Ehdr)), f);
2415 fwrite(phdr, 1, phnum * sizeof(ElfW(Phdr)), f);
2416 offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr));
2417
2418 sort_syms(s1, symtab_section);
2419 for(i = 1; i < s1->nb_sections; i++) {
2420 s = s1->sections[sec_order[i]];
2421 if (s->sh_type != SHT_NOBITS) {
2422 if (s->sh_type == SHT_DYNSYM)
2423 patch_dynsym_undef(s1, s);
2424 while (offset < s->sh_offset) {
2425 fputc(0, f);
2426 offset++;
2427 }
2428 size = s->sh_size;
2429 if (size)
2430 fwrite(s->data, 1, size, f);
2431 offset += size;
2432 }
2433 }
2434
2435 /* output section headers */
2436 while (offset < ehdr.e_shoff) {
2437 fputc(0, f);
2438 offset++;
2439 }
2440
2441 for(i = 0; i < s1->nb_sections; i++) {
2442 sh = &shdr;
2443 memset(sh, 0, sizeof(ElfW(Shdr)));
2444 s = s1->sections[i];
2445 if (s) {
2446 sh->sh_name = s->sh_name;
2447 sh->sh_type = s->sh_type;
2448 sh->sh_flags = s->sh_flags;
2449 sh->sh_entsize = s->sh_entsize;
2450 sh->sh_info = s->sh_info;
2451 if (s->link)
2452 sh->sh_link = s->link->sh_num;
2453 sh->sh_addralign = s->sh_addralign;
2454 sh->sh_addr = s->sh_addr;
2455 sh->sh_offset = s->sh_offset;
2456 sh->sh_size = s->sh_size;
2457 }
2458 fwrite(sh, 1, sizeof(ElfW(Shdr)), f);
2459 }
2460 }
2461
2462 /* Write an elf, coff or "binary" file */
2463 static int tcc_write_elf_file(TCCState *s1, const char *filename, int phnum,
2464 ElfW(Phdr) *phdr, int file_offset, int *sec_order)
2465 {
2466 int fd, mode, file_type;
2467 FILE *f;
2468
2469 file_type = s1->output_type;
2470 if (file_type == TCC_OUTPUT_OBJ)
2471 mode = 0666;
2472 else
2473 mode = 0777;
2474 unlink(filename);
2475 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, mode);
2476 if (fd < 0) {
2477 tcc_error_noabort("could not write '%s'", filename);
2478 return -1;
2479 }
2480 f = fdopen(fd, "wb");
2481 if (s1->verbose)
2482 printf("<- %s\n", filename);
2483
2484 #ifdef TCC_TARGET_COFF
2485 if (s1->output_format == TCC_OUTPUT_FORMAT_COFF)
2486 tcc_output_coff(s1, f);
2487 else
2488 #endif
2489 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF)
2490 tcc_output_elf(s1, f, phnum, phdr, file_offset, sec_order);
2491 else
2492 tcc_output_binary(s1, f, sec_order);
2493 fclose(f);
2494
2495 return 0;
2496 }
2497
2498 /* Output an elf, coff or binary file */
2499 /* XXX: suppress unneeded sections */
2500 static int elf_output_file(TCCState *s1, const char *filename)
2501 {
2502 int i, ret, phnum, shnum, file_type, file_offset, *sec_order;
2503 struct dyn_inf dyninf;
2504 ElfW(Phdr) *phdr;
2505 ElfW(Sym) *sym;
2506 Section *strsec, *interp, *dynamic, *dynstr;
2507
2508 file_type = s1->output_type;
2509 s1->nb_errors = 0;
2510
2511 /* if linking, also link in runtime libraries (libc, libgcc, etc.) */
2512 if (file_type != TCC_OUTPUT_OBJ) {
2513 tcc_add_runtime(s1);
2514 }
2515
2516 phdr = NULL;
2517 sec_order = NULL;
2518 interp = dynamic = dynstr = NULL; /* avoid warning */
2519 dyninf.dyn_rel_off = 0; /* avoid warning */
2520
2521 if (file_type != TCC_OUTPUT_OBJ) {
2522 relocate_common_syms();
2523
2524 tcc_add_linker_symbols(s1);
2525
2526 if (!s1->static_link) {
2527 if (file_type == TCC_OUTPUT_EXE) {
2528 char *ptr;
2529 /* allow override the dynamic loader */
2530 const char *elfint = getenv("LD_SO");
2531 if (elfint == NULL)
2532 elfint = DEFAULT_ELFINTERP(s1);
2533 /* add interpreter section only if executable */
2534 interp = new_section(s1, ".interp", SHT_PROGBITS, SHF_ALLOC);
2535 interp->sh_addralign = 1;
2536 ptr = section_ptr_add(interp, 1 + strlen(elfint));
2537 strcpy(ptr, elfint);
2538 }
2539
2540 /* add dynamic symbol table */
2541 s1->dynsym = new_symtab(s1, ".dynsym", SHT_DYNSYM, SHF_ALLOC,
2542 ".dynstr",
2543 ".hash", SHF_ALLOC);
2544 dynstr = s1->dynsym->link;
2545
2546 /* add dynamic section */
2547 dynamic = new_section(s1, ".dynamic", SHT_DYNAMIC,
2548 SHF_ALLOC | SHF_WRITE);
2549 dynamic->link = dynstr;
2550 dynamic->sh_entsize = sizeof(ElfW(Dyn));
2551
2552 build_got(s1);
2553
2554 if (file_type == TCC_OUTPUT_EXE) {
2555 bind_exe_dynsyms(s1);
2556
2557 if (s1->nb_errors) {
2558 ret = -1;
2559 goto the_end;
2560 }
2561
2562 bind_libs_dynsyms(s1);
2563 } else /* shared library case: simply export all global symbols */
2564 export_global_syms(s1);
2565
2566 build_got_entries(s1);
2567
2568 /* add a list of needed dlls */
2569 for(i = 0; i < s1->nb_loaded_dlls; i++) {
2570 DLLReference *dllref = s1->loaded_dlls[i];
2571 if (dllref->level == 0)
2572 put_dt(dynamic, DT_NEEDED, put_elf_str(dynstr, dllref->name));
2573 }
2574
2575 if (s1->rpath)
2576 put_dt(dynamic, DT_RPATH, put_elf_str(dynstr, s1->rpath));
2577
2578 /* XXX: currently, since we do not handle PIC code, we
2579 must relocate the readonly segments */
2580 if (file_type == TCC_OUTPUT_DLL) {
2581 if (s1->soname)
2582 put_dt(dynamic, DT_SONAME, put_elf_str(dynstr, s1->soname));
2583 put_dt(dynamic, DT_TEXTREL, 0);
2584 }
2585
2586 if (s1->symbolic)
2587 put_dt(dynamic, DT_SYMBOLIC, 0);
2588
2589 /* add necessary space for other entries */
2590 dyninf.dyn_rel_off = dynamic->data_offset;
2591 dynamic->data_offset += sizeof(ElfW(Dyn)) * EXTRA_RELITEMS;
2592 } else {
2593 /* still need to build got entries in case of static link */
2594 build_got_entries(s1);
2595 }
2596 }
2597
2598 /* we add a section for symbols */
2599 strsec = new_section(s1, ".shstrtab", SHT_STRTAB, 0);
2600 put_elf_str(strsec, "");
2601
2602 /* compute number of sections */
2603 shnum = s1->nb_sections;
2604
2605 /* this array is used to reorder sections in the output file */
2606 sec_order = tcc_malloc(sizeof(int) * shnum);
2607 sec_order[0] = 0;
2608
2609 /* compute number of program headers */
2610 switch(file_type) {
2611 default:
2612 case TCC_OUTPUT_OBJ:
2613 phnum = 0;
2614 break;
2615 case TCC_OUTPUT_EXE:
2616 if (!s1->static_link)
2617 phnum = 4 + HAVE_PHDR;
2618 else
2619 phnum = 2;
2620 break;
2621 case TCC_OUTPUT_DLL:
2622 phnum = 3;
2623 break;
2624 }
2625
2626 /* Allocate strings for section names */
2627 alloc_sec_names(s1, file_type, strsec);
2628
2629 /* allocate program segment headers */
2630 phdr = tcc_mallocz(phnum * sizeof(ElfW(Phdr)));
2631
2632 /* compute section to program header mapping */
2633 file_offset = layout_sections(s1, phdr, phnum, interp, strsec, &dyninf,
2634 sec_order);
2635
2636 /* Fill remaining program header and finalize relocation related to dynamic
2637 linking. */
2638 if (phnum > 0) {
2639 fill_unloadable_phdr(phdr, phnum, interp, dynamic);
2640 if (dynamic) {
2641 dyninf.dynamic = dynamic;
2642 dyninf.dynstr = dynstr;
2643
2644 fill_dynamic(s1, &dyninf);
2645
2646 /* put in GOT the dynamic section address and relocate PLT */
2647 write32le(s1->got->data, dynamic->sh_addr);
2648 if (file_type == TCC_OUTPUT_EXE
2649 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
2650 || file_type == TCC_OUTPUT_DLL
2651 #endif
2652 )
2653 relocate_plt(s1);
2654
2655 /* relocate symbols in .dynsym now that final addresses are known */
2656 for_each_elem(s1->dynsym, 1, sym, ElfW(Sym)) {
2657 if (sym->st_shndx == SHN_UNDEF) {
2658 /* relocate to PLT if symbol corresponds to a PLT entry,
2659 but not if it's a weak symbol */
2660 if (ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
2661 sym->st_value = 0;
2662 else if (sym->st_value)
2663 sym->st_value += s1->plt->sh_addr;
2664 } else if (sym->st_shndx < SHN_LORESERVE) {
2665 /* do symbol relocation */
2666 sym->st_value += s1->sections[sym->st_shndx]->sh_addr;
2667 }
2668 }
2669 }
2670 }
2671
2672 /* if building executable or DLL, then relocate each section
2673 except the GOT which is already relocated */
2674 if (file_type != TCC_OUTPUT_OBJ) {
2675 ret = final_sections_reloc(s1);
2676 if (ret)
2677 goto the_end;
2678 }
2679
2680 /* Perform relocation to GOT or PLT entries */
2681 if (file_type == TCC_OUTPUT_EXE && s1->static_link)
2682 fill_got(s1);
2683
2684 /* Create the ELF file with name 'filename' */
2685 ret = tcc_write_elf_file(s1, filename, phnum, phdr, file_offset, sec_order);
2686 if (s1->do_strip) {
2687 int rc;
2688 const char *strip_cmd = "sstrip "; // super strip utility from ELFkickers
2689 const char *null_dev = " 2> /dev/null";
2690 char buf[1050];
2691 snprintf(buf, sizeof(buf), "%s%s%s", strip_cmd, filename, null_dev);
2692 rc = system(buf);
2693 if (rc)
2694 system(buf+1); // call a strip utility from binutils
2695 }
2696 the_end:
2697 tcc_free(s1->symtab_to_dynsym);
2698 tcc_free(sec_order);
2699 tcc_free(phdr);
2700 tcc_free(s1->sym_attrs);
2701 s1->sym_attrs = NULL;
2702 return ret;
2703 }
2704
2705 LIBTCCAPI int tcc_output_file(TCCState *s, const char *filename)
2706 {
2707 int ret;
2708 #ifdef TCC_TARGET_PE
2709 if (s->output_type != TCC_OUTPUT_OBJ) {
2710 ret = pe_output_file(s, filename);
2711 } else
2712 #endif
2713 ret = elf_output_file(s, filename);
2714 return ret;
2715 }
2716
2717 static void *load_data(int fd, unsigned long file_offset, unsigned long size)
2718 {
2719 void *data;
2720
2721 data = tcc_malloc(size);
2722 lseek(fd, file_offset, SEEK_SET);
2723 read(fd, data, size);
2724 return data;
2725 }
2726
2727 typedef struct SectionMergeInfo {
2728 Section *s; /* corresponding existing section */
2729 unsigned long offset; /* offset of the new section in the existing section */
2730 uint8_t new_section; /* true if section 's' was added */
2731 uint8_t link_once; /* true if link once section */
2732 } SectionMergeInfo;
2733
2734 /* load an object file and merge it with current files */
2735 /* XXX: handle correctly stab (debug) info */
2736 ST_FUNC int tcc_load_object_file(TCCState *s1,
2737 int fd, unsigned long file_offset)
2738 {
2739 ElfW(Ehdr) ehdr;
2740 ElfW(Shdr) *shdr, *sh;
2741 int size, i, j, offset, offseti, nb_syms, sym_index, ret;
2742 unsigned char *strsec, *strtab;
2743 int *old_to_new_syms;
2744 char *sh_name, *name;
2745 SectionMergeInfo *sm_table, *sm;
2746 ElfW(Sym) *sym, *symtab;
2747 ElfW_Rel *rel;
2748 Section *s;
2749
2750 int stab_index;
2751 int stabstr_index;
2752
2753 stab_index = stabstr_index = 0;
2754
2755 if (read(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr))
2756 goto fail1;
2757 if (ehdr.e_ident[0] != ELFMAG0 ||
2758 ehdr.e_ident[1] != ELFMAG1 ||
2759 ehdr.e_ident[2] != ELFMAG2 ||
2760 ehdr.e_ident[3] != ELFMAG3)
2761 goto fail1;
2762 /* test if object file */
2763 if (ehdr.e_type != ET_REL)
2764 goto fail1;
2765 /* test CPU specific stuff */
2766 if (ehdr.e_ident[5] != ELFDATA2LSB ||
2767 ehdr.e_machine != EM_TCC_TARGET) {
2768 fail1:
2769 tcc_error_noabort("invalid object file");
2770 return -1;
2771 }
2772 /* read sections */
2773 shdr = load_data(fd, file_offset + ehdr.e_shoff,
2774 sizeof(ElfW(Shdr)) * ehdr.e_shnum);
2775 sm_table = tcc_mallocz(sizeof(SectionMergeInfo) * ehdr.e_shnum);
2776
2777 /* load section names */
2778 sh = &shdr[ehdr.e_shstrndx];
2779 strsec = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2780
2781 /* load symtab and strtab */
2782 old_to_new_syms = NULL;
2783 symtab = NULL;
2784 strtab = NULL;
2785 nb_syms = 0;
2786 for(i = 1; i < ehdr.e_shnum; i++) {
2787 sh = &shdr[i];
2788 if (sh->sh_type == SHT_SYMTAB) {
2789 if (symtab) {
2790 tcc_error_noabort("object must contain only one symtab");
2791 fail:
2792 ret = -1;
2793 goto the_end;
2794 }
2795 nb_syms = sh->sh_size / sizeof(ElfW(Sym));
2796 symtab = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2797 sm_table[i].s = symtab_section;
2798
2799 /* now load strtab */
2800 sh = &shdr[sh->sh_link];
2801 strtab = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2802 }
2803 }
2804
2805 /* now examine each section and try to merge its content with the
2806 ones in memory */
2807 for(i = 1; i < ehdr.e_shnum; i++) {
2808 /* no need to examine section name strtab */
2809 if (i == ehdr.e_shstrndx)
2810 continue;
2811 sh = &shdr[i];
2812 sh_name = (char *) strsec + sh->sh_name;
2813 /* ignore sections types we do not handle */
2814 if (sh->sh_type != SHT_PROGBITS &&
2815 sh->sh_type != SHT_RELX &&
2816 #ifdef TCC_ARM_EABI
2817 sh->sh_type != SHT_ARM_EXIDX &&
2818 #endif
2819 sh->sh_type != SHT_NOBITS &&
2820 sh->sh_type != SHT_PREINIT_ARRAY &&
2821 sh->sh_type != SHT_INIT_ARRAY &&
2822 sh->sh_type != SHT_FINI_ARRAY &&
2823 strcmp(sh_name, ".stabstr")
2824 )
2825 continue;
2826 if (sh->sh_addralign < 1)
2827 sh->sh_addralign = 1;
2828 /* find corresponding section, if any */
2829 for(j = 1; j < s1->nb_sections;j++) {
2830 s = s1->sections[j];
2831 if (!strcmp(s->name, sh_name)) {
2832 if (!strncmp(sh_name, ".gnu.linkonce",
2833 sizeof(".gnu.linkonce") - 1)) {
2834 /* if a 'linkonce' section is already present, we
2835 do not add it again. It is a little tricky as
2836 symbols can still be defined in
2837 it. */
2838 sm_table[i].link_once = 1;
2839 goto next;
2840 } else {
2841 goto found;
2842 }
2843 }
2844 }
2845 /* not found: create new section */
2846 s = new_section(s1, sh_name, sh->sh_type, sh->sh_flags);
2847 /* take as much info as possible from the section. sh_link and
2848 sh_info will be updated later */
2849 s->sh_addralign = sh->sh_addralign;
2850 s->sh_entsize = sh->sh_entsize;
2851 sm_table[i].new_section = 1;
2852 found:
2853 if (sh->sh_type != s->sh_type) {
2854 tcc_error_noabort("invalid section type");
2855 goto fail;
2856 }
2857
2858 /* align start of section */
2859 offset = s->data_offset;
2860
2861 if (0 == strcmp(sh_name, ".stab")) {
2862 stab_index = i;
2863 goto no_align;
2864 }
2865 if (0 == strcmp(sh_name, ".stabstr")) {
2866 stabstr_index = i;
2867 goto no_align;
2868 }
2869
2870 size = sh->sh_addralign - 1;
2871 offset = (offset + size) & ~size;
2872 if (sh->sh_addralign > s->sh_addralign)
2873 s->sh_addralign = sh->sh_addralign;
2874 s->data_offset = offset;
2875 no_align:
2876 sm_table[i].offset = offset;
2877 sm_table[i].s = s;
2878 /* concatenate sections */
2879 size = sh->sh_size;
2880 if (sh->sh_type != SHT_NOBITS) {
2881 unsigned char *ptr;
2882 lseek(fd, file_offset + sh->sh_offset, SEEK_SET);
2883 ptr = section_ptr_add(s, size);
2884 read(fd, ptr, size);
2885 } else {
2886 s->data_offset += size;
2887 }
2888 next: ;
2889 }
2890
2891 /* gr relocate stab strings */
2892 if (stab_index && stabstr_index) {
2893 Stab_Sym *a, *b;
2894 unsigned o;
2895 s = sm_table[stab_index].s;
2896 a = (Stab_Sym *)(s->data + sm_table[stab_index].offset);
2897 b = (Stab_Sym *)(s->data + s->data_offset);
2898 o = sm_table[stabstr_index].offset;
2899 while (a < b)
2900 a->n_strx += o, a++;
2901 }
2902
2903 /* second short pass to update sh_link and sh_info fields of new
2904 sections */
2905 for(i = 1; i < ehdr.e_shnum; i++) {
2906 s = sm_table[i].s;
2907 if (!s || !sm_table[i].new_section)
2908 continue;
2909 sh = &shdr[i];
2910 if (sh->sh_link > 0)
2911 s->link = sm_table[sh->sh_link].s;
2912 if (sh->sh_type == SHT_RELX) {
2913 s->sh_info = sm_table[sh->sh_info].s->sh_num;
2914 /* update backward link */
2915 s1->sections[s->sh_info]->reloc = s;
2916 }
2917 }
2918 sm = sm_table;
2919
2920 /* resolve symbols */
2921 old_to_new_syms = tcc_mallocz(nb_syms * sizeof(int));
2922
2923 sym = symtab + 1;
2924 for(i = 1; i < nb_syms; i++, sym++) {
2925 if (sym->st_shndx != SHN_UNDEF &&
2926 sym->st_shndx < SHN_LORESERVE) {
2927 sm = &sm_table[sym->st_shndx];
2928 if (sm->link_once) {
2929 /* if a symbol is in a link once section, we use the
2930 already defined symbol. It is very important to get
2931 correct relocations */
2932 if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
2933 name = (char *) strtab + sym->st_name;
2934 sym_index = find_elf_sym(symtab_section, name);
2935 if (sym_index)
2936 old_to_new_syms[i] = sym_index;
2937 }
2938 continue;
2939 }
2940 /* if no corresponding section added, no need to add symbol */
2941 if (!sm->s)
2942 continue;
2943 /* convert section number */
2944 sym->st_shndx = sm->s->sh_num;
2945 /* offset value */
2946 sym->st_value += sm->offset;
2947 }
2948 /* add symbol */
2949 name = (char *) strtab + sym->st_name;
2950 sym_index = add_elf_sym(symtab_section, sym->st_value, sym->st_size,
2951 sym->st_info, sym->st_other,
2952 sym->st_shndx, name);
2953 old_to_new_syms[i] = sym_index;
2954 }
2955
2956 /* third pass to patch relocation entries */
2957 for(i = 1; i < ehdr.e_shnum; i++) {
2958 s = sm_table[i].s;
2959 if (!s)
2960 continue;
2961 sh = &shdr[i];
2962 offset = sm_table[i].offset;
2963 switch(s->sh_type) {
2964 case SHT_RELX:
2965 /* take relocation offset information */
2966 offseti = sm_table[sh->sh_info].offset;
2967 for_each_elem(s, (offset / sizeof(*rel)), rel, ElfW_Rel) {
2968 int type;
2969 unsigned sym_index;
2970 /* convert symbol index */
2971 type = ELFW(R_TYPE)(rel->r_info);
2972 sym_index = ELFW(R_SYM)(rel->r_info);
2973 /* NOTE: only one symtab assumed */
2974 if (sym_index >= nb_syms)
2975 goto invalid_reloc;
2976 sym_index = old_to_new_syms[sym_index];
2977 /* ignore link_once in rel section. */
2978 if (!sym_index && !sm->link_once
2979 #ifdef TCC_TARGET_ARM
2980 && type != R_ARM_V4BX
2981 #endif
2982 ) {
2983 invalid_reloc:
2984 tcc_error_noabort("Invalid relocation entry [%2d] '%s' @ %.8x",
2985 i, strsec + sh->sh_name, rel->r_offset);
2986 goto fail;
2987 }
2988 rel->r_info = ELFW(R_INFO)(sym_index, type);
2989 /* offset the relocation offset */
2990 rel->r_offset += offseti;
2991 #ifdef TCC_TARGET_ARM
2992 /* Jumps and branches from a Thumb code to a PLT entry need
2993 special handling since PLT entries are ARM code.
2994 Unconditional bl instructions referencing PLT entries are
2995 handled by converting these instructions into blx
2996 instructions. Other case of instructions referencing a PLT
2997 entry require to add a Thumb stub before the PLT entry to
2998 switch to ARM mode. We set bit plt_thumb_stub of the
2999 attribute of a symbol to indicate such a case. */
3000 if (type == R_ARM_THM_JUMP24)
3001 alloc_sym_attr(s1, sym_index)->plt_thumb_stub = 1;
3002 #endif
3003 }
3004 break;
3005 default:
3006 break;
3007 }
3008 }
3009
3010 ret = 0;
3011 the_end:
3012 tcc_free(symtab);
3013 tcc_free(strtab);
3014 tcc_free(old_to_new_syms);
3015 tcc_free(sm_table);
3016 tcc_free(strsec);
3017 tcc_free(shdr);
3018 return ret;
3019 }
3020
3021 typedef struct ArchiveHeader {
3022 char ar_name[16]; /* name of this member */
3023 char ar_date[12]; /* file mtime */
3024 char ar_uid[6]; /* owner uid; printed as decimal */
3025 char ar_gid[6]; /* owner gid; printed as decimal */
3026 char ar_mode[8]; /* file mode, printed as octal */
3027 char ar_size[10]; /* file size, printed as decimal */
3028 char ar_fmag[2]; /* should contain ARFMAG */
3029 } ArchiveHeader;
3030
3031 static int get_be32(const uint8_t *b)
3032 {
3033 return b[3] | (b[2] << 8) | (b[1] << 16) | (b[0] << 24);
3034 }
3035
3036 /* load only the objects which resolve undefined symbols */
3037 static int tcc_load_alacarte(TCCState *s1, int fd, int size)
3038 {
3039 int i, bound, nsyms, sym_index, off, ret;
3040 uint8_t *data;
3041 const char *ar_names, *p;
3042 const uint8_t *ar_index;
3043 ElfW(Sym) *sym;
3044
3045 data = tcc_malloc(size);
3046 if (read(fd, data, size) != size)
3047 goto fail;
3048 nsyms = get_be32(data);
3049 ar_index = data + 4;
3050 ar_names = (char *) ar_index + nsyms * 4;
3051
3052 do {
3053 bound = 0;
3054 for(p = ar_names, i = 0; i < nsyms; i++, p += strlen(p)+1) {
3055 sym_index = find_elf_sym(symtab_section, p);
3056 if(sym_index) {
3057 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
3058 if(sym->st_shndx == SHN_UNDEF) {
3059 off = get_be32(ar_index + i * 4) + sizeof(ArchiveHeader);
3060 ++bound;
3061 lseek(fd, off, SEEK_SET);
3062 if(tcc_load_object_file(s1, fd, off) < 0) {
3063 fail:
3064 ret = -1;
3065 goto the_end;
3066 }
3067 }
3068 }
3069 }
3070 } while(bound);
3071 ret = 0;
3072 the_end:
3073 tcc_free(data);
3074 return ret;
3075 }
3076
3077 /* load a '.a' file */
3078 ST_FUNC int tcc_load_archive(TCCState *s1, int fd)
3079 {
3080 ArchiveHeader hdr;
3081 char ar_size[11];
3082 char ar_name[17];
3083 char magic[8];
3084 int size, len, i;
3085 unsigned long file_offset;
3086
3087 /* skip magic which was already checked */
3088 read(fd, magic, sizeof(magic));
3089
3090 for(;;) {
3091 len = read(fd, &hdr, sizeof(hdr));
3092 if (len == 0)
3093 break;
3094 if (len != sizeof(hdr)) {
3095 tcc_error_noabort("invalid archive");
3096 return -1;
3097 }
3098 memcpy(ar_size, hdr.ar_size, sizeof(hdr.ar_size));
3099 ar_size[sizeof(hdr.ar_size)] = '\0';
3100 size = strtol(ar_size, NULL, 0);
3101 memcpy(ar_name, hdr.ar_name, sizeof(hdr.ar_name));
3102 for(i = sizeof(hdr.ar_name) - 1; i >= 0; i--) {
3103 if (ar_name[i] != ' ')
3104 break;
3105 }
3106 ar_name[i + 1] = '\0';
3107 file_offset = lseek(fd, 0, SEEK_CUR);
3108 /* align to even */
3109 size = (size + 1) & ~1;
3110 if (!strcmp(ar_name, "/")) {
3111 /* coff symbol table : we handle it */
3112 if(s1->alacarte_link)
3113 return tcc_load_alacarte(s1, fd, size);
3114 } else if (!strcmp(ar_name, "//") ||
3115 !strcmp(ar_name, "__.SYMDEF") ||
3116 !strcmp(ar_name, "__.SYMDEF/") ||
3117 !strcmp(ar_name, "ARFILENAMES/")) {
3118 /* skip symbol table or archive names */
3119 } else {
3120 if (tcc_load_object_file(s1, fd, file_offset) < 0)
3121 return -1;
3122 }
3123 lseek(fd, file_offset + size, SEEK_SET);
3124 }
3125 return 0;
3126 }
3127
3128 #ifndef TCC_TARGET_PE
3129 /* load a DLL and all referenced DLLs. 'level = 0' means that the DLL
3130 is referenced by the user (so it should be added as DT_NEEDED in
3131 the generated ELF file) */
3132 ST_FUNC int tcc_load_dll(TCCState *s1, int fd, const char *filename, int level)
3133 {
3134 ElfW(Ehdr) ehdr;
3135 ElfW(Shdr) *shdr, *sh, *sh1;
3136 int i, j, nb_syms, nb_dts, sym_bind, ret;
3137 ElfW(Sym) *sym, *dynsym;
3138 ElfW(Dyn) *dt, *dynamic;
3139 unsigned char *dynstr;
3140 const char *name, *soname;
3141 DLLReference *dllref;
3142
3143 read(fd, &ehdr, sizeof(ehdr));
3144
3145 /* test CPU specific stuff */
3146 if (ehdr.e_ident[5] != ELFDATA2LSB ||
3147 ehdr.e_machine != EM_TCC_TARGET) {
3148 tcc_error_noabort("bad architecture");
3149 return -1;
3150 }
3151
3152 /* read sections */
3153 shdr = load_data(fd, ehdr.e_shoff, sizeof(ElfW(Shdr)) * ehdr.e_shnum);
3154
3155 /* load dynamic section and dynamic symbols */
3156 nb_syms = 0;
3157 nb_dts = 0;
3158 dynamic = NULL;
3159 dynsym = NULL; /* avoid warning */
3160 dynstr = NULL; /* avoid warning */
3161 for(i = 0, sh = shdr; i < ehdr.e_shnum; i++, sh++) {
3162 switch(sh->sh_type) {
3163 case SHT_DYNAMIC:
3164 nb_dts = sh->sh_size / sizeof(ElfW(Dyn));
3165 dynamic = load_data(fd, sh->sh_offset, sh->sh_size);
3166 break;
3167 case SHT_DYNSYM:
3168 nb_syms = sh->sh_size / sizeof(ElfW(Sym));
3169 dynsym = load_data(fd, sh->sh_offset, sh->sh_size);
3170 sh1 = &shdr[sh->sh_link];
3171 dynstr = load_data(fd, sh1->sh_offset, sh1->sh_size);
3172 break;
3173 default:
3174 break;
3175 }
3176 }
3177
3178 /* compute the real library name */
3179 soname = tcc_basename(filename);
3180
3181 for(i = 0, dt = dynamic; i < nb_dts; i++, dt++) {
3182 if (dt->d_tag == DT_SONAME) {
3183 soname = (char *) dynstr + dt->d_un.d_val;
3184 }
3185 }
3186
3187 /* if the dll is already loaded, do not load it */
3188 for(i = 0; i < s1->nb_loaded_dlls; i++) {
3189 dllref = s1->loaded_dlls[i];
3190 if (!strcmp(soname, dllref->name)) {
3191 /* but update level if needed */
3192 if (level < dllref->level)
3193 dllref->level = level;
3194 ret = 0;
3195 goto the_end;
3196 }
3197 }
3198
3199 /* add the dll and its level */
3200 dllref = tcc_mallocz(sizeof(DLLReference) + strlen(soname));
3201 dllref->level = level;
3202 strcpy(dllref->name, soname);
3203 dynarray_add((void ***)&s1->loaded_dlls, &s1->nb_loaded_dlls, dllref);
3204
3205 /* add dynamic symbols in dynsym_section */
3206 for(i = 1, sym = dynsym + 1; i < nb_syms; i++, sym++) {
3207 sym_bind = ELFW(ST_BIND)(sym->st_info);
3208 if (sym_bind == STB_LOCAL)
3209 continue;
3210 name = (char *) dynstr + sym->st_name;
3211 add_elf_sym(s1->dynsymtab_section, sym->st_value, sym->st_size,
3212 sym->st_info, sym->st_other, sym->st_shndx, name);
3213 }
3214
3215 /* load all referenced DLLs */
3216 for(i = 0, dt = dynamic; i < nb_dts; i++, dt++) {
3217 switch(dt->d_tag) {
3218 case DT_NEEDED:
3219 name = (char *) dynstr + dt->d_un.d_val;
3220 for(j = 0; j < s1->nb_loaded_dlls; j++) {
3221 dllref = s1->loaded_dlls[j];
3222 if (!strcmp(name, dllref->name))
3223 goto already_loaded;
3224 }
3225 if (tcc_add_dll(s1, name, AFF_REFERENCED_DLL) < 0) {
3226 tcc_error_noabort("referenced dll '%s' not found", name);
3227 ret = -1;
3228 goto the_end;
3229 }
3230 already_loaded:
3231 break;
3232 }
3233 }
3234 ret = 0;
3235 the_end:
3236 tcc_free(dynstr);
3237 tcc_free(dynsym);
3238 tcc_free(dynamic);
3239 tcc_free(shdr);
3240 return ret;
3241 }
3242
3243 #define LD_TOK_NAME 256
3244 #define LD_TOK_EOF (-1)
3245
3246 /* return next ld script token */
3247 static int ld_next(TCCState *s1, char *name, int name_size)
3248 {
3249 int c;
3250 char *q;
3251
3252 redo:
3253 switch(ch) {
3254 case ' ':
3255 case '\t':
3256 case '\f':
3257 case '\v':
3258 case '\r':
3259 case '\n':
3260 inp();
3261 goto redo;
3262 case '/':
3263 minp();
3264 if (ch == '*') {
3265 file->buf_ptr = parse_comment(file->buf_ptr);
3266 ch = file->buf_ptr[0];
3267 goto redo;
3268 } else {
3269 q = name;
3270 *q++ = '/';
3271 goto parse_name;
3272 }
3273 break;
3274 case '\\':
3275 ch = handle_eob();
3276 if (ch != '\\')
3277 goto redo;
3278 /* fall through */
3279 /* case 'a' ... 'z': */
3280 case 'a':
3281 case 'b':
3282 case 'c':
3283 case 'd':
3284 case 'e':
3285 case 'f':
3286 case 'g':
3287 case 'h':
3288 case 'i':
3289 case 'j':
3290 case 'k':
3291 case 'l':
3292 case 'm':
3293 case 'n':
3294 case 'o':
3295 case 'p':
3296 case 'q':
3297 case 'r':
3298 case 's':
3299 case 't':
3300 case 'u':
3301 case 'v':
3302 case 'w':
3303 case 'x':
3304 case 'y':
3305 case 'z':
3306 /* case 'A' ... 'z': */
3307 case 'A':
3308 case 'B':
3309 case 'C':
3310 case 'D':
3311 case 'E':
3312 case 'F':
3313 case 'G':
3314 case 'H':
3315 case 'I':
3316 case 'J':
3317 case 'K':
3318 case 'L':
3319 case 'M':
3320 case 'N':
3321 case 'O':
3322 case 'P':
3323 case 'Q':
3324 case 'R':
3325 case 'S':
3326 case 'T':
3327 case 'U':
3328 case 'V':
3329 case 'W':
3330 case 'X':
3331 case 'Y':
3332 case 'Z':
3333 case '_':
3334 case '.':
3335 case '$':
3336 case '~':
3337 q = name;
3338 parse_name:
3339 for(;;) {
3340 if (!((ch >= 'a' && ch <= 'z') ||
3341 (ch >= 'A' && ch <= 'Z') ||
3342 (ch >= '0' && ch <= '9') ||
3343 strchr("/.-_+=$:\\,~", ch)))
3344 break;
3345 if ((q - name) < name_size - 1) {
3346 *q++ = ch;
3347 }
3348 minp();
3349 }
3350 *q = '\0';
3351 c = LD_TOK_NAME;
3352 break;
3353 case CH_EOF:
3354 c = LD_TOK_EOF;
3355 break;
3356 default:
3357 c = ch;
3358 inp();
3359 break;
3360 }
3361 return c;
3362 }
3363
3364 static int ld_add_file(TCCState *s1, const char filename[])
3365 {
3366 int ret;
3367
3368 ret = tcc_add_file_internal(s1, filename, 0, TCC_FILETYPE_BINARY);
3369 if (ret)
3370 ret = tcc_add_dll(s1, filename, 0);
3371 return ret;
3372 }
3373
3374 static inline int new_undef_syms(void)
3375 {
3376 int ret = 0;
3377 ret = new_undef_sym;
3378 new_undef_sym = 0;
3379 return ret;
3380 }
3381
3382 static int ld_add_file_list(TCCState *s1, const char *cmd, int as_needed)
3383 {
3384 char filename[1024], libname[1024];
3385 int t, group, nblibs = 0, ret = 0;
3386 char **libs = NULL;
3387
3388 group = !strcmp(cmd, "GROUP");
3389 if (!as_needed)
3390 new_undef_syms();
3391 t = ld_next(s1, filename, sizeof(filename));
3392 if (t != '(')
3393 expect("(");
3394 t = ld_next(s1, filename, sizeof(filename));
3395 for(;;) {
3396 libname[0] = '\0';
3397 if (t == LD_TOK_EOF) {
3398 tcc_error_noabort("unexpected end of file");
3399 ret = -1;
3400 goto lib_parse_error;
3401 } else if (t == ')') {
3402 break;
3403 } else if (t == '-') {
3404 t = ld_next(s1, filename, sizeof(filename));
3405 if ((t != LD_TOK_NAME) || (filename[0] != 'l')) {
3406 tcc_error_noabort("library name expected");
3407 ret = -1;
3408 goto lib_parse_error;
3409 }
3410 pstrcpy(libname, sizeof libname, &filename[1]);
3411 if (s1->static_link) {
3412 snprintf(filename, sizeof filename, "lib%s.a", libname);
3413 } else {
3414 snprintf(filename, sizeof filename, "lib%s.so", libname);
3415 }
3416 } else if (t != LD_TOK_NAME) {
3417 tcc_error_noabort("filename expected");
3418 ret = -1;
3419 goto lib_parse_error;
3420 }
3421 if (!strcmp(filename, "AS_NEEDED")) {
3422 ret = ld_add_file_list(s1, cmd, 1);
3423 if (ret)
3424 goto lib_parse_error;
3425 } else {
3426 /* TODO: Implement AS_NEEDED support. Ignore it for now */
3427 if (!as_needed) {
3428 ret = ld_add_file(s1, filename);
3429 if (ret)
3430 goto lib_parse_error;
3431 if (group) {
3432 /* Add the filename *and* the libname to avoid future conversions */
3433 dynarray_add((void ***) &libs, &nblibs, tcc_strdup(filename));
3434 if (libname[0] != '\0')
3435 dynarray_add((void ***) &libs, &nblibs, tcc_strdup(libname));
3436 }
3437 }
3438 }
3439 t = ld_next(s1, filename, sizeof(filename));
3440 if (t == ',') {
3441 t = ld_next(s1, filename, sizeof(filename));
3442 }
3443 }
3444 if (group && !as_needed) {
3445 while (new_undef_syms()) {
3446 int i;
3447
3448 for (i = 0; i < nblibs; i ++)
3449 ld_add_file(s1, libs[i]);
3450 }
3451 }
3452 lib_parse_error:
3453 dynarray_reset(&libs, &nblibs);
3454 return ret;
3455 }
3456
3457 /* interpret a subset of GNU ldscripts to handle the dummy libc.so
3458 files */
3459 ST_FUNC int tcc_load_ldscript(TCCState *s1)
3460 {
3461 char cmd[64];
3462 char filename[1024];
3463 int t, ret;
3464
3465 ch = handle_eob();
3466 for(;;) {
3467 t = ld_next(s1, cmd, sizeof(cmd));
3468 if (t == LD_TOK_EOF)
3469 return 0;
3470 else if (t != LD_TOK_NAME)
3471 return -1;
3472 if (!strcmp(cmd, "INPUT") ||
3473 !strcmp(cmd, "GROUP")) {
3474 ret = ld_add_file_list(s1, cmd, 0);
3475 if (ret)
3476 return ret;
3477 } else if (!strcmp(cmd, "OUTPUT_FORMAT") ||
3478 !strcmp(cmd, "TARGET")) {
3479 /* ignore some commands */
3480 t = ld_next(s1, cmd, sizeof(cmd));
3481 if (t != '(')
3482 expect("(");
3483 for(;;) {
3484 t = ld_next(s1, filename, sizeof(filename));
3485 if (t == LD_TOK_EOF) {
3486 tcc_error_noabort("unexpected end of file");
3487 return -1;
3488 } else if (t == ')') {
3489 break;
3490 }
3491 }
3492 } else {
3493 return -1;
3494 }
3495 }
3496 return 0;
3497 }
3498 #endif /* !TCC_TARGET_PE */
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