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libtcc: filetype cleanup
[tinycc.git] / tccelf.c
blobd47027b8c7956803b3de16929462c9c5a6f699b3
1 /*
2 * ELF file handling for TCC
3 *
4 * Copyright (c) 2001-2004 Fabrice Bellard
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 */
20
21 #include "tcc.h"
22
23 /* Define this to get some debug output during relocation processing. */
24 #undef DEBUG_RELOC
25
26 /* XXX: avoid static variable */
27 static int new_undef_sym = 0; /* Is there a new undefined sym since last new_undef_sym() */
28
29 ST_FUNC int put_elf_str(Section *s, const char *sym)
30 {
31 int offset, len;
32 char *ptr;
33
34 len = strlen(sym) + 1;
35 offset = s->data_offset;
36 ptr = section_ptr_add(s, len);
37 memcpy(ptr, sym, len);
38 return offset;
39 }
40
41 /* elf symbol hashing function */
42 static unsigned long elf_hash(const unsigned char *name)
43 {
44 unsigned long h = 0, g;
45
46 while (*name) {
47 h = (h << 4) + *name++;
48 g = h & 0xf0000000;
49 if (g)
50 h ^= g >> 24;
51 h &= ~g;
52 }
53 return h;
54 }
55
56 /* rebuild hash table of section s */
57 /* NOTE: we do factorize the hash table code to go faster */
58 static void rebuild_hash(Section *s, unsigned int nb_buckets)
59 {
60 ElfW(Sym) *sym;
61 int *ptr, *hash, nb_syms, sym_index, h;
62 unsigned char *strtab;
63
64 strtab = s->link->data;
65 nb_syms = s->data_offset / sizeof(ElfW(Sym));
66
67 s->hash->data_offset = 0;
68 ptr = section_ptr_add(s->hash, (2 + nb_buckets + nb_syms) * sizeof(int));
69 ptr[0] = nb_buckets;
70 ptr[1] = nb_syms;
71 ptr += 2;
72 hash = ptr;
73 memset(hash, 0, (nb_buckets + 1) * sizeof(int));
74 ptr += nb_buckets + 1;
75
76 sym = (ElfW(Sym) *)s->data + 1;
77 for(sym_index = 1; sym_index < nb_syms; sym_index++) {
78 if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
79 h = elf_hash(strtab + sym->st_name) % nb_buckets;
80 *ptr = hash[h];
81 hash[h] = sym_index;
82 } else {
83 *ptr = 0;
84 }
85 ptr++;
86 sym++;
87 }
88 }
89
90 /* return the symbol number */
91 ST_FUNC int put_elf_sym(Section *s, addr_t value, unsigned long size,
92 int info, int other, int shndx, const char *name)
93 {
94 int name_offset, sym_index;
95 int nbuckets, h;
96 ElfW(Sym) *sym;
97 Section *hs;
98
99 sym = section_ptr_add(s, sizeof(ElfW(Sym)));
100 if (name)
101 name_offset = put_elf_str(s->link, name);
102 else
103 name_offset = 0;
104 /* XXX: endianness */
105 sym->st_name = name_offset;
106 sym->st_value = value;
107 sym->st_size = size;
108 sym->st_info = info;
109 sym->st_other = other;
110 sym->st_shndx = shndx;
111 sym_index = sym - (ElfW(Sym) *)s->data;
112 hs = s->hash;
113 if (hs) {
114 int *ptr, *base;
115 ptr = section_ptr_add(hs, sizeof(int));
116 base = (int *)hs->data;
117 /* only add global or weak symbols */
118 if (ELFW(ST_BIND)(info) != STB_LOCAL) {
119 /* add another hashing entry */
120 nbuckets = base[0];
121 h = elf_hash((unsigned char *) name) % nbuckets;
122 *ptr = base[2 + h];
123 base[2 + h] = sym_index;
124 base[1]++;
125 /* we resize the hash table */
126 hs->nb_hashed_syms++;
127 if (hs->nb_hashed_syms > 2 * nbuckets) {
128 rebuild_hash(s, 2 * nbuckets);
129 }
130 } else {
131 *ptr = 0;
132 base[1]++;
133 }
134 }
135 return sym_index;
136 }
137
138 /* find global ELF symbol 'name' and return its index. Return 0 if not
139 found. */
140 ST_FUNC int find_elf_sym(Section *s, const char *name)
141 {
142 ElfW(Sym) *sym;
143 Section *hs;
144 int nbuckets, sym_index, h;
145 const char *name1;
146
147 hs = s->hash;
148 if (!hs)
149 return 0;
150 nbuckets = ((int *)hs->data)[0];
151 h = elf_hash((unsigned char *) name) % nbuckets;
152 sym_index = ((int *)hs->data)[2 + h];
153 while (sym_index != 0) {
154 sym = &((ElfW(Sym) *)s->data)[sym_index];
155 name1 = (char *) s->link->data + sym->st_name;
156 if (!strcmp(name, name1))
157 return sym_index;
158 sym_index = ((int *)hs->data)[2 + nbuckets + sym_index];
159 }
160 return 0;
161 }
162
163 /* return elf symbol value, signal error if 'err' is nonzero */
164 ST_FUNC addr_t get_elf_sym_addr(TCCState *s, const char *name, int err)
165 {
166 int sym_index;
167 ElfW(Sym) *sym;
168
169 sym_index = find_elf_sym(s->symtab, name);
170 sym = &((ElfW(Sym) *)s->symtab->data)[sym_index];
171 if (!sym_index || sym->st_shndx == SHN_UNDEF) {
172 if (err)
173 tcc_error("%s not defined", name);
174 return 0;
175 }
176 return sym->st_value;
177 }
178
179 /* return elf symbol value */
180 LIBTCCAPI void *tcc_get_symbol(TCCState *s, const char *name)
181 {
182 return (void*)(uintptr_t)get_elf_sym_addr(s, name, 0);
183 }
184
185 #if defined TCC_IS_NATIVE || defined TCC_TARGET_PE
186 /* return elf symbol value or error */
187 ST_FUNC void* tcc_get_symbol_err(TCCState *s, const char *name)
188 {
189 return (void*)(uintptr_t)get_elf_sym_addr(s, name, 1);
190 }
191 #endif
192
193 /* add an elf symbol : check if it is already defined and patch
194 it. Return symbol index. NOTE that sh_num can be SHN_UNDEF. */
195 ST_FUNC int add_elf_sym(Section *s, addr_t value, unsigned long size,
196 int info, int other, int sh_num, const char *name)
197 {
198 ElfW(Sym) *esym;
199 int sym_bind, sym_index, sym_type, esym_bind;
200 unsigned char sym_vis, esym_vis, new_vis;
201
202 sym_bind = ELFW(ST_BIND)(info);
203 sym_type = ELFW(ST_TYPE)(info);
204 sym_vis = ELFW(ST_VISIBILITY)(other);
205
206 if (sym_bind != STB_LOCAL) {
207 /* we search global or weak symbols */
208 sym_index = find_elf_sym(s, name);
209 if (!sym_index)
210 goto do_def;
211 esym = &((ElfW(Sym) *)s->data)[sym_index];
212 if (esym->st_shndx != SHN_UNDEF) {
213 esym_bind = ELFW(ST_BIND)(esym->st_info);
214 /* propagate the most constraining visibility */
215 /* STV_DEFAULT(0)<STV_PROTECTED(3)<STV_HIDDEN(2)<STV_INTERNAL(1) */
216 esym_vis = ELFW(ST_VISIBILITY)(esym->st_other);
217 if (esym_vis == STV_DEFAULT) {
218 new_vis = sym_vis;
219 } else if (sym_vis == STV_DEFAULT) {
220 new_vis = esym_vis;
221 } else {
222 new_vis = (esym_vis < sym_vis) ? esym_vis : sym_vis;
223 }
224 esym->st_other = (esym->st_other & ~ELFW(ST_VISIBILITY)(-1))
225 | new_vis;
226 other = esym->st_other; /* in case we have to patch esym */
227 if (sh_num == SHN_UNDEF) {
228 /* ignore adding of undefined symbol if the
229 corresponding symbol is already defined */
230 } else if (sym_bind == STB_GLOBAL && esym_bind == STB_WEAK) {
231 /* global overrides weak, so patch */
232 goto do_patch;
233 } else if (sym_bind == STB_WEAK && esym_bind == STB_GLOBAL) {
234 /* weak is ignored if already global */
235 } else if (sym_bind == STB_WEAK && esym_bind == STB_WEAK) {
236 /* keep first-found weak definition, ignore subsequents */
237 } else if (sym_vis == STV_HIDDEN || sym_vis == STV_INTERNAL) {
238 /* ignore hidden symbols after */
239 } else if (esym->st_shndx == SHN_COMMON
240 && (sh_num < SHN_LORESERVE || sh_num == SHN_COMMON)) {
241 /* gr: Happens with 'tcc ... -static tcctest.c' on e.g. Ubuntu 6.01
242 No idea if this is the correct solution ... */
243 goto do_patch;
244 } else if (s == tcc_state->dynsymtab_section) {
245 /* we accept that two DLL define the same symbol */
246 } else {
247 #if 0
248 printf("new_bind=%x new_shndx=%x new_vis=%x old_bind=%x old_shndx=%x old_vis=%x\n",
249 sym_bind, sh_num, new_vis, esym_bind, esym->st_shndx, esym_vis);
250 #endif
251 tcc_error_noabort("'%s' defined twice... may be -fcommon is needed?", name);
252 }
253 } else {
254 do_patch:
255 esym->st_info = ELFW(ST_INFO)(sym_bind, sym_type);
256 esym->st_shndx = sh_num;
257 new_undef_sym = 1;
258 esym->st_value = value;
259 esym->st_size = size;
260 esym->st_other = other;
261 }
262 } else {
263 do_def:
264 sym_index = put_elf_sym(s, value, size,
265 ELFW(ST_INFO)(sym_bind, sym_type), other,
266 sh_num, name);
267 }
268 return sym_index;
269 }
270
271 /* put relocation */
272 ST_FUNC void put_elf_reloca(Section *symtab, Section *s, unsigned long offset,
273 int type, int symbol, addr_t addend)
274 {
275 char buf[256];
276 Section *sr;
277 ElfW_Rel *rel;
278
279 sr = s->reloc;
280 if (!sr) {
281 /* if no relocation section, create it */
282 snprintf(buf, sizeof(buf), REL_SECTION_FMT, s->name);
283 /* if the symtab is allocated, then we consider the relocation
284 are also */
285 sr = new_section(tcc_state, buf, SHT_RELX, symtab->sh_flags);
286 sr->sh_entsize = sizeof(ElfW_Rel);
287 sr->link = symtab;
288 sr->sh_info = s->sh_num;
289 s->reloc = sr;
290 }
291 rel = section_ptr_add(sr, sizeof(ElfW_Rel));
292 rel->r_offset = offset;
293 rel->r_info = ELFW(R_INFO)(symbol, type);
294 #if defined(TCC_TARGET_ARM64) || defined(TCC_TARGET_X86_64)
295 rel->r_addend = addend;
296 #else
297 if (addend)
298 tcc_error("non-zero addend on REL architecture");
299 #endif
300 }
301
302 ST_FUNC void put_elf_reloc(Section *symtab, Section *s, unsigned long offset,
303 int type, int symbol)
304 {
305 put_elf_reloca(symtab, s, offset, type, symbol, 0);
306 }
307
308 /* put stab debug information */
309
310 ST_FUNC void put_stabs(const char *str, int type, int other, int desc,
311 unsigned long value)
312 {
313 Stab_Sym *sym;
314
315 sym = section_ptr_add(stab_section, sizeof(Stab_Sym));
316 if (str) {
317 sym->n_strx = put_elf_str(stabstr_section, str);
318 } else {
319 sym->n_strx = 0;
320 }
321 sym->n_type = type;
322 sym->n_other = other;
323 sym->n_desc = desc;
324 sym->n_value = value;
325 }
326
327 ST_FUNC void put_stabs_r(const char *str, int type, int other, int desc,
328 unsigned long value, Section *sec, int sym_index)
329 {
330 put_stabs(str, type, other, desc, value);
331 put_elf_reloc(symtab_section, stab_section,
332 stab_section->data_offset - sizeof(unsigned int),
333 R_DATA_32, sym_index);
334 }
335
336 ST_FUNC void put_stabn(int type, int other, int desc, int value)
337 {
338 put_stabs(NULL, type, other, desc, value);
339 }
340
341 ST_FUNC void put_stabd(int type, int other, int desc)
342 {
343 put_stabs(NULL, type, other, desc, 0);
344 }
345
346 /* Browse each elem of type <type> in section <sec> starting at elem <startoff>
347 using variable <elem> */
348 #define for_each_elem(sec, startoff, elem, type) \
349 for (elem = (type *) sec->data + startoff; \
350 elem < (type *) (sec->data + sec->data_offset); elem++)
351
352 /* In an ELF file symbol table, the local symbols must appear below
353 the global and weak ones. Since TCC cannot sort it while generating
354 the code, we must do it after. All the relocation tables are also
355 modified to take into account the symbol table sorting */
356 static void sort_syms(TCCState *s1, Section *s)
357 {
358 int *old_to_new_syms;
359 ElfW(Sym) *new_syms;
360 int nb_syms, i;
361 ElfW(Sym) *p, *q;
362 ElfW_Rel *rel;
363 Section *sr;
364 int type, sym_index;
365
366 nb_syms = s->data_offset / sizeof(ElfW(Sym));
367 new_syms = tcc_malloc(nb_syms * sizeof(ElfW(Sym)));
368 old_to_new_syms = tcc_malloc(nb_syms * sizeof(int));
369
370 /* first pass for local symbols */
371 p = (ElfW(Sym) *)s->data;
372 q = new_syms;
373 for(i = 0; i < nb_syms; i++) {
374 if (ELFW(ST_BIND)(p->st_info) == STB_LOCAL) {
375 old_to_new_syms[i] = q - new_syms;
376 *q++ = *p;
377 }
378 p++;
379 }
380 /* save the number of local symbols in section header */
381 s->sh_info = q - new_syms;
382
383 /* then second pass for non local symbols */
384 p = (ElfW(Sym) *)s->data;
385 for(i = 0; i < nb_syms; i++) {
386 if (ELFW(ST_BIND)(p->st_info) != STB_LOCAL) {
387 old_to_new_syms[i] = q - new_syms;
388 *q++ = *p;
389 }
390 p++;
391 }
392
393 /* we copy the new symbols to the old */
394 memcpy(s->data, new_syms, nb_syms * sizeof(ElfW(Sym)));
395 tcc_free(new_syms);
396
397 /* now we modify all the relocations */
398 for(i = 1; i < s1->nb_sections; i++) {
399 sr = s1->sections[i];
400 if (sr->sh_type == SHT_RELX && sr->link == s) {
401 for_each_elem(sr, 0, rel, ElfW_Rel) {
402 sym_index = ELFW(R_SYM)(rel->r_info);
403 type = ELFW(R_TYPE)(rel->r_info);
404 sym_index = old_to_new_syms[sym_index];
405 rel->r_info = ELFW(R_INFO)(sym_index, type);
406 }
407 }
408 }
409
410 tcc_free(old_to_new_syms);
411 }
412
413 /* relocate common symbols in the .bss section */
414 ST_FUNC void relocate_common_syms(void)
415 {
416 ElfW(Sym) *sym;
417 unsigned long offset, align;
418
419 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
420 if (sym->st_shndx == SHN_COMMON) {
421 /* align symbol */
422 align = sym->st_value;
423 offset = bss_section->data_offset;
424 offset = (offset + align - 1) & -align;
425 sym->st_value = offset;
426 sym->st_shndx = bss_section->sh_num;
427 offset += sym->st_size;
428 bss_section->data_offset = offset;
429 }
430 }
431 }
432
433 /* relocate symbol table, resolve undefined symbols if do_resolve is
434 true and output error if undefined symbol. */
435 ST_FUNC void relocate_syms(TCCState *s1, int do_resolve)
436 {
437 ElfW(Sym) *sym, *esym;
438 int sym_bind, sh_num, sym_index;
439 const char *name;
440
441 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
442 sh_num = sym->st_shndx;
443 if (sh_num == SHN_UNDEF) {
444 name = (char *) strtab_section->data + sym->st_name;
445 /* Use ld.so to resolve symbol for us (for tcc -run) */
446 if (do_resolve) {
447 #if defined TCC_IS_NATIVE && !defined _WIN32
448 void *addr;
449 name = (char *) symtab_section->link->data + sym->st_name;
450 addr = resolve_sym(s1, name);
451 if (addr) {
452 sym->st_value = (addr_t)addr;
453 #ifdef DEBUG_RELOC
454 printf ("relocate_sym: %s -> 0x%lx\n", name, sym->st_value);
455 #endif
456 goto found;
457 }
458 #endif
459 } else if (s1->dynsym) {
460 /* if dynamic symbol exist, then use it */
461 sym_index = find_elf_sym(s1->dynsym, name);
462 if (sym_index) {
463 esym = &((ElfW(Sym) *)s1->dynsym->data)[sym_index];
464 sym->st_value = esym->st_value;
465 goto found;
466 }
467 }
468 /* XXX: _fp_hw seems to be part of the ABI, so we ignore
469 it */
470 if (!strcmp(name, "_fp_hw"))
471 goto found;
472 /* only weak symbols are accepted to be undefined. Their
473 value is zero */
474 sym_bind = ELFW(ST_BIND)(sym->st_info);
475 if (sym_bind == STB_WEAK) {
476 sym->st_value = 0;
477 } else {
478 tcc_error_noabort("undefined symbol '%s'", name);
479 }
480 } else if (sh_num < SHN_LORESERVE) {
481 /* add section base */
482 sym->st_value += s1->sections[sym->st_shndx]->sh_addr;
483 }
484 found: ;
485 }
486 }
487
488 /* relocate a given section (CPU dependent) by applying the relocations
489 in the associated relocation section */
490 ST_FUNC void relocate_section(TCCState *s1, Section *s)
491 {
492 Section *sr = s->reloc;
493 ElfW_Rel *rel;
494 ElfW(Sym) *sym;
495 int type, sym_index;
496 unsigned char *ptr;
497 addr_t val, addr;
498 #if defined TCC_TARGET_I386 || defined TCC_TARGET_X86_64
499 ElfW_Rel *qrel = (ElfW_Rel *) sr->data; /* ptr to next reloc entry reused */
500 int esym_index;
501 #endif
502
503 for_each_elem(sr, 0, rel, ElfW_Rel) {
504 ptr = s->data + rel->r_offset;
505
506 sym_index = ELFW(R_SYM)(rel->r_info);
507 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
508 val = sym->st_value;
509 #if defined(TCC_TARGET_ARM64) || defined(TCC_TARGET_X86_64)
510 val += rel->r_addend;
511 #endif
512 type = ELFW(R_TYPE)(rel->r_info);
513 addr = s->sh_addr + rel->r_offset;
514
515 /* CPU specific */
516 switch(type) {
517 #if defined(TCC_TARGET_I386)
518 case R_386_32:
519 if (s1->output_type == TCC_OUTPUT_DLL) {
520 esym_index = s1->symtab_to_dynsym[sym_index];
521 qrel->r_offset = rel->r_offset;
522 if (esym_index) {
523 qrel->r_info = ELFW(R_INFO)(esym_index, R_386_32);
524 qrel++;
525 break;
526 } else {
527 qrel->r_info = ELFW(R_INFO)(0, R_386_RELATIVE);
528 qrel++;
529 }
530 }
531 write32le(ptr, read32le(ptr) + val);
532 break;
533 case R_386_PC32:
534 if (s1->output_type == TCC_OUTPUT_DLL) {
535 /* DLL relocation */
536 esym_index = s1->symtab_to_dynsym[sym_index];
537 if (esym_index) {
538 qrel->r_offset = rel->r_offset;
539 qrel->r_info = ELFW(R_INFO)(esym_index, R_386_PC32);
540 qrel++;
541 break;
542 }
543 }
544 write32le(ptr, read32le(ptr) + val - addr);
545 break;
546 case R_386_PLT32:
547 write32le(ptr, read32le(ptr) + val - addr);
548 break;
549 case R_386_GLOB_DAT:
550 case R_386_JMP_SLOT:
551 write32le(ptr, val);
552 break;
553 case R_386_GOTPC:
554 write32le(ptr, read32le(ptr) + s1->got->sh_addr - addr);
555 break;
556 case R_386_GOTOFF:
557 write32le(ptr, read32le(ptr) + val - s1->got->sh_addr);
558 break;
559 case R_386_GOT32:
560 case R_386_GOT32X:
561 /* we load the got offset */
562 write32le(ptr, read32le(ptr) + s1->sym_attrs[sym_index].got_offset);
563 break;
564 case R_386_16:
565 if (s1->output_format != TCC_OUTPUT_FORMAT_BINARY) {
566 output_file:
567 tcc_error("can only produce 16-bit binary files");
568 }
569 write16le(ptr, read16le(ptr) + val);
570 break;
571 case R_386_PC16:
572 if (s1->output_format != TCC_OUTPUT_FORMAT_BINARY)
573 goto output_file;
574 write16le(ptr, read16le(ptr) + val - addr);
575 break;
576 case R_386_RELATIVE:
577 /* do nothing */
578 break;
579 case R_386_COPY:
580 /* This reloction must copy initialized data from the library
581 to the program .bss segment. Currently made like for ARM
582 (to remove noise of defaukt case). Is this true?
583 */
584 break;
585 default:
586 fprintf(stderr,"FIXME: handle reloc type %d at %x [%p] to %x\n",
587 type, (unsigned)addr, ptr, (unsigned)val);
588 break;
589 #elif defined(TCC_TARGET_ARM)
590 case R_ARM_PC24:
591 case R_ARM_CALL:
592 case R_ARM_JUMP24:
593 case R_ARM_PLT32:
594 {
595 int x, is_thumb, is_call, h, blx_avail, is_bl, th_ko;
596 x = (*(int *) ptr) & 0xffffff;
597 if (sym->st_shndx == SHN_UNDEF)
598 val = s1->plt->sh_addr;
599 #ifdef DEBUG_RELOC
600 printf ("reloc %d: x=0x%x val=0x%x ", type, x, val);
601 #endif
602 (*(int *)ptr) &= 0xff000000;
603 if (x & 0x800000)
604 x -= 0x1000000;
605 x <<= 2;
606 blx_avail = (TCC_ARM_VERSION >= 5);
607 is_thumb = val & 1;
608 is_bl = (*(unsigned *) ptr) >> 24 == 0xeb;
609 is_call = (type == R_ARM_CALL || (type == R_ARM_PC24 && is_bl));
610 x += val - addr;
611 #ifdef DEBUG_RELOC
612 printf (" newx=0x%x name=%s\n", x,
613 (char *) symtab_section->link->data + sym->st_name);
614 #endif
615 h = x & 2;
616 th_ko = (x & 3) && (!blx_avail || !is_call);
617 if (th_ko || x >= 0x2000000 || x < -0x2000000)
618 tcc_error("can't relocate value at %x,%d",addr, type);
619 x >>= 2;
620 x &= 0xffffff;
621 /* Only reached if blx is avail and it is a call */
622 if (is_thumb) {
623 x |= h << 24;
624 (*(int *)ptr) = 0xfa << 24; /* bl -> blx */
625 }
626 (*(int *) ptr) |= x;
627 }
628 break;
629 /* Since these relocations only concern Thumb-2 and blx instruction was
630 introduced before Thumb-2, we can assume blx is available and not
631 guard its use */
632 case R_ARM_THM_PC22:
633 case R_ARM_THM_JUMP24:
634 {
635 int x, hi, lo, s, j1, j2, i1, i2, imm10, imm11;
636 int to_thumb, is_call, to_plt, blx_bit = 1 << 12;
637 Section *plt;
638
639 /* weak reference */
640 if (sym->st_shndx == SHN_UNDEF &&
641 ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
642 break;
643
644 /* Get initial offset */
645 hi = (*(uint16_t *)ptr);
646 lo = (*(uint16_t *)(ptr+2));
647 s = (hi >> 10) & 1;
648 j1 = (lo >> 13) & 1;
649 j2 = (lo >> 11) & 1;
650 i1 = (j1 ^ s) ^ 1;
651 i2 = (j2 ^ s) ^ 1;
652 imm10 = hi & 0x3ff;
653 imm11 = lo & 0x7ff;
654 x = (s << 24) | (i1 << 23) | (i2 << 22) |
655 (imm10 << 12) | (imm11 << 1);
656 if (x & 0x01000000)
657 x -= 0x02000000;
658
659 /* Relocation infos */
660 to_thumb = val & 1;
661 plt = s1->plt;
662 to_plt = (val >= plt->sh_addr) &&
663 (val < plt->sh_addr + plt->data_offset);
664 is_call = (type == R_ARM_THM_PC22);
665
666 /* Compute final offset */
667 if (to_plt && !is_call) /* Point to 1st instr of Thumb stub */
668 x -= 4;
669 x += val - addr;
670 if (!to_thumb && is_call) {
671 blx_bit = 0; /* bl -> blx */
672 x = (x + 3) & -4; /* Compute offset from aligned PC */
673 }
674
675 /* Check that relocation is possible
676 * offset must not be out of range
677 * if target is to be entered in arm mode:
678 - bit 1 must not set
679 - instruction must be a call (bl) or a jump to PLT */
680 if (!to_thumb || x >= 0x1000000 || x < -0x1000000)
681 if (to_thumb || (val & 2) || (!is_call && !to_plt))
682 tcc_error("can't relocate value at %x,%d",addr, type);
683
684 /* Compute and store final offset */
685 s = (x >> 24) & 1;
686 i1 = (x >> 23) & 1;
687 i2 = (x >> 22) & 1;
688 j1 = s ^ (i1 ^ 1);
689 j2 = s ^ (i2 ^ 1);
690 imm10 = (x >> 12) & 0x3ff;
691 imm11 = (x >> 1) & 0x7ff;
692 (*(uint16_t *)ptr) = (uint16_t) ((hi & 0xf800) |
693 (s << 10) | imm10);
694 (*(uint16_t *)(ptr+2)) = (uint16_t) ((lo & 0xc000) |
695 (j1 << 13) | blx_bit | (j2 << 11) |
696 imm11);
697 }
698 break;
699 case R_ARM_MOVT_ABS:
700 case R_ARM_MOVW_ABS_NC:
701 {
702 int x, imm4, imm12;
703 if (type == R_ARM_MOVT_ABS)
704 val >>= 16;
705 imm12 = val & 0xfff;
706 imm4 = (val >> 12) & 0xf;
707 x = (imm4 << 16) | imm12;
708 if (type == R_ARM_THM_MOVT_ABS)
709 *(int *)ptr |= x;
710 else
711 *(int *)ptr += x;
712 }
713 break;
714 case R_ARM_THM_MOVT_ABS:
715 case R_ARM_THM_MOVW_ABS_NC:
716 {
717 int x, i, imm4, imm3, imm8;
718 if (type == R_ARM_THM_MOVT_ABS)
719 val >>= 16;
720 imm8 = val & 0xff;
721 imm3 = (val >> 8) & 0x7;
722 i = (val >> 11) & 1;
723 imm4 = (val >> 12) & 0xf;
724 x = (imm3 << 28) | (imm8 << 16) | (i << 10) | imm4;
725 if (type == R_ARM_THM_MOVT_ABS)
726 *(int *)ptr |= x;
727 else
728 *(int *)ptr += x;
729 }
730 break;
731 case R_ARM_PREL31:
732 {
733 int x;
734 x = (*(int *)ptr) & 0x7fffffff;
735 (*(int *)ptr) &= 0x80000000;
736 x = (x * 2) / 2;
737 x += val - addr;
738 if((x^(x>>1))&0x40000000)
739 tcc_error("can't relocate value at %x,%d",addr, type);
740 (*(int *)ptr) |= x & 0x7fffffff;
741 }
742 case R_ARM_ABS32:
743 *(int *)ptr += val;
744 break;
745 case R_ARM_REL32:
746 *(int *)ptr += val - addr;
747 break;
748 case R_ARM_GOTPC:
749 *(int *)ptr += s1->got->sh_addr - addr;
750 break;
751 case R_ARM_GOTOFF:
752 *(int *)ptr += val - s1->got->sh_addr;
753 break;
754 case R_ARM_GOT32:
755 /* we load the got offset */
756 *(int *)ptr += s1->sym_attrs[sym_index].got_offset;
757 break;
758 case R_ARM_COPY:
759 break;
760 case R_ARM_V4BX:
761 /* trade Thumb support for ARMv4 support */
762 if ((0x0ffffff0 & *(int*)ptr) == 0x012FFF10)
763 *(int*)ptr ^= 0xE12FFF10 ^ 0xE1A0F000; /* BX Rm -> MOV PC, Rm */
764 break;
765 case R_ARM_GLOB_DAT:
766 case R_ARM_JUMP_SLOT:
767 *(addr_t *)ptr = val;
768 break;
769 case R_ARM_NONE:
770 /* Nothing to do. Normally used to indicate a dependency
771 on a certain symbol (like for exception handling under EABI). */
772 break;
773 default:
774 fprintf(stderr,"FIXME: handle reloc type %x at %x [%p] to %x\n",
775 type, (unsigned)addr, ptr, (unsigned)val);
776 break;
777 #elif defined(TCC_TARGET_ARM64)
778 case R_AARCH64_ABS64:
779 write64le(ptr, val);
780 break;
781 case R_AARCH64_ABS32:
782 write32le(ptr, val);
783 break;
784 case R_AARCH64_MOVW_UABS_G0_NC:
785 write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
786 (val & 0xffff) << 5));
787 break;
788 case R_AARCH64_MOVW_UABS_G1_NC:
789 write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
790 (val >> 16 & 0xffff) << 5));
791 break;
792 case R_AARCH64_MOVW_UABS_G2_NC:
793 write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
794 (val >> 32 & 0xffff) << 5));
795 break;
796 case R_AARCH64_MOVW_UABS_G3:
797 write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
798 (val >> 48 & 0xffff) << 5));
799 break;
800 case R_AARCH64_ADR_PREL_PG_HI21: {
801 uint64_t off = (val >> 12) - (addr >> 12);
802 if ((off + ((uint64_t)1 << 20)) >> 21)
803 tcc_error("R_AARCH64_ADR_PREL_PG_HI21 relocation failed");
804 write32le(ptr, ((read32le(ptr) & 0x9f00001f) |
805 (off & 0x1ffffc) << 3 | (off & 3) << 29));
806 break;
807 }
808 case R_AARCH64_ADD_ABS_LO12_NC:
809 write32le(ptr, ((read32le(ptr) & 0xffc003ff) |
810 (val & 0xfff) << 10));
811 break;
812 case R_AARCH64_JUMP26:
813 case R_AARCH64_CALL26:
814 /* This check must match the one in build_got_entries, testing
815 if we really need a PLT slot. */
816 if (sym->st_shndx == SHN_UNDEF)
817 /* We've put the PLT slot offset into r_addend when generating
818 it, and that's what we must use as relocation value (adjusted
819 by section offset of course). */
820 val = s1->plt->sh_addr + rel->r_addend;
821 #ifdef DEBUG_RELOC
822 printf ("reloc %d @ 0x%lx: val=0x%lx name=%s\n", type, addr, val,
823 (char *) symtab_section->link->data + sym->st_name);
824 #endif
825 if (((val - addr) + ((uint64_t)1 << 27)) & ~(uint64_t)0xffffffc)
826 {
827 tcc_error("R_AARCH64_(JUMP|CALL)26 relocation failed (val=%lx, addr=%lx)", addr, val);
828 }
829 write32le(ptr, (0x14000000 |
830 (uint32_t)(type == R_AARCH64_CALL26) << 31 |
831 ((val - addr) >> 2 & 0x3ffffff)));
832 break;
833 case R_AARCH64_ADR_GOT_PAGE: {
834 uint64_t off =
835 (((s1->got->sh_addr +
836 s1->sym_attrs[sym_index].got_offset) >> 12) - (addr >> 12));
837 if ((off + ((uint64_t)1 << 20)) >> 21)
838 tcc_error("R_AARCH64_ADR_GOT_PAGE relocation failed");
839 write32le(ptr, ((read32le(ptr) & 0x9f00001f) |
840 (off & 0x1ffffc) << 3 | (off & 3) << 29));
841 break;
842 }
843 case R_AARCH64_LD64_GOT_LO12_NC:
844 write32le(ptr,
845 ((read32le(ptr) & 0xfff803ff) |
846 ((s1->got->sh_addr +
847 s1->sym_attrs[sym_index].got_offset) & 0xff8) << 7));
848 break;
849 case R_AARCH64_COPY:
850 break;
851 case R_AARCH64_GLOB_DAT:
852 case R_AARCH64_JUMP_SLOT:
853 /* They don't need addend */
854 #ifdef DEBUG_RELOC
855 printf ("reloc %d @ 0x%lx: val=0x%lx name=%s\n", type, addr,
856 val - rel->r_addend,
857 (char *) symtab_section->link->data + sym->st_name);
858 #endif
859 write64le(ptr, val - rel->r_addend);
860 break;
861 default:
862 fprintf(stderr, "FIXME: handle reloc type %x at %x [%p] to %x\n",
863 type, (unsigned)addr, ptr, (unsigned)val);
864 break;
865 #elif defined(TCC_TARGET_C67)
866 case R_C60_32:
867 *(int *)ptr += val;
868 break;
869 case R_C60LO16:
870 {
871 uint32_t orig;
872
873 /* put the low 16 bits of the absolute address
874 add to what is already there */
875
876 orig = ((*(int *)(ptr )) >> 7) & 0xffff;
877 orig |= (((*(int *)(ptr+4)) >> 7) & 0xffff) << 16;
878
879 /* patch both at once - assumes always in pairs Low - High */
880
881 *(int *) ptr = (*(int *) ptr & (~(0xffff << 7)) ) | (((val+orig) & 0xffff) << 7);
882 *(int *)(ptr+4) = (*(int *)(ptr+4) & (~(0xffff << 7)) ) | ((((val+orig)>>16) & 0xffff) << 7);
883 }
884 break;
885 case R_C60HI16:
886 break;
887 default:
888 fprintf(stderr,"FIXME: handle reloc type %x at %x [%p] to %x\n",
889 type, (unsigned)addr, ptr, (unsigned)val);
890 break;
891 #elif defined(TCC_TARGET_X86_64)
892 case R_X86_64_64:
893 if (s1->output_type == TCC_OUTPUT_DLL) {
894 esym_index = s1->symtab_to_dynsym[sym_index];
895 qrel->r_offset = rel->r_offset;
896 if (esym_index) {
897 qrel->r_info = ELFW(R_INFO)(esym_index, R_X86_64_64);
898 qrel->r_addend = rel->r_addend;
899 qrel++;
900 break;
901 } else {
902 qrel->r_info = ELFW(R_INFO)(0, R_X86_64_RELATIVE);
903 qrel->r_addend = read64le(ptr) + val;
904 qrel++;
905 }
906 }
907 write64le(ptr, read64le(ptr) + val);
908 break;
909 case R_X86_64_32:
910 case R_X86_64_32S:
911 if (s1->output_type == TCC_OUTPUT_DLL) {
912 /* XXX: this logic may depend on TCC's codegen
913 now TCC uses R_X86_64_32 even for a 64bit pointer */
914 qrel->r_info = ELFW(R_INFO)(0, R_X86_64_RELATIVE);
915 /* Use sign extension! */
916 qrel->r_addend = (int)read32le(ptr) + val;
917 qrel++;
918 }
919 write32le(ptr, read32le(ptr) + val);
920 break;
921
922 case R_X86_64_PC32:
923 if (s1->output_type == TCC_OUTPUT_DLL) {
924 /* DLL relocation */
925 esym_index = s1->symtab_to_dynsym[sym_index];
926 if (esym_index) {
927 qrel->r_offset = rel->r_offset;
928 qrel->r_info = ELFW(R_INFO)(esym_index, R_X86_64_PC32);
929 /* Use sign extension! */
930 qrel->r_addend = (int)read32le(ptr) + rel->r_addend;
931 qrel++;
932 break;
933 }
934 }
935 goto plt32pc32;
936
937 case R_X86_64_PLT32:
938 /* We've put the PLT slot offset into r_addend when generating
939 it, and that's what we must use as relocation value (adjusted
940 by section offset of course). */
941 val = s1->plt->sh_addr + rel->r_addend;
942 /* fallthrough. */
943
944 plt32pc32:
945 {
946 long long diff;
947 diff = (long long)val - addr;
948 if (diff < -2147483648LL || diff > 2147483647LL) {
949 tcc_error("internal error: relocation failed");
950 }
951 write32le(ptr, read32le(ptr) + diff);
952 }
953 break;
954 case R_X86_64_GLOB_DAT:
955 case R_X86_64_JUMP_SLOT:
956 /* They don't need addend */
957 write64le(ptr, val - rel->r_addend);
958 break;
959 case R_X86_64_GOTPCREL:
960 case R_X86_64_GOTPCRELX:
961 case R_X86_64_REX_GOTPCRELX:
962 write32le(ptr, read32le(ptr) +
963 (s1->got->sh_addr - addr +
964 s1->sym_attrs[sym_index].got_offset - 4));
965 break;
966 case R_X86_64_GOTTPOFF:
967 write32le(ptr, read32le(ptr) + val - s1->got->sh_addr);
968 break;
969 case R_X86_64_GOT32:
970 /* we load the got offset */
971 write32le(ptr, read32le(ptr) + s1->sym_attrs[sym_index].got_offset);
972 break;
973 #else
974 #error unsupported processor
975 #endif
976 }
977 }
978 /* if the relocation is allocated, we change its symbol table */
979 if (sr->sh_flags & SHF_ALLOC)
980 sr->link = s1->dynsym;
981 }
982
983 /* relocate relocation table in 'sr' */
984 static void relocate_rel(TCCState *s1, Section *sr)
985 {
986 Section *s;
987 ElfW_Rel *rel;
988
989 s = s1->sections[sr->sh_info];
990 for_each_elem(sr, 0, rel, ElfW_Rel)
991 rel->r_offset += s->sh_addr;
992 }
993
994 /* count the number of dynamic relocations so that we can reserve
995 their space */
996 static int prepare_dynamic_rel(TCCState *s1, Section *sr)
997 {
998 ElfW_Rel *rel;
999 int sym_index, esym_index, type, count;
1000
1001 count = 0;
1002 for_each_elem(sr, 0, rel, ElfW_Rel) {
1003 sym_index = ELFW(R_SYM)(rel->r_info);
1004 type = ELFW(R_TYPE)(rel->r_info);
1005 switch(type) {
1006 #if defined(TCC_TARGET_I386)
1007 case R_386_32:
1008 #elif defined(TCC_TARGET_X86_64)
1009 case R_X86_64_32:
1010 case R_X86_64_32S:
1011 case R_X86_64_64:
1012 #endif
1013 count++;
1014 break;
1015 #if defined(TCC_TARGET_I386)
1016 case R_386_PC32:
1017 #elif defined(TCC_TARGET_X86_64)
1018 case R_X86_64_PC32:
1019 #endif
1020 esym_index = s1->symtab_to_dynsym[sym_index];
1021 if (esym_index)
1022 count++;
1023 break;
1024 default:
1025 break;
1026 }
1027 }
1028 if (count) {
1029 /* allocate the section */
1030 sr->sh_flags |= SHF_ALLOC;
1031 sr->sh_size = count * sizeof(ElfW_Rel);
1032 }
1033 return count;
1034 }
1035
1036 static struct sym_attr *alloc_sym_attr(TCCState *s1, int index)
1037 {
1038 int n;
1039 struct sym_attr *tab;
1040
1041 if (index >= s1->nb_sym_attrs) {
1042 /* find immediately bigger power of 2 and reallocate array */
1043 n = 1;
1044 while (index >= n)
1045 n *= 2;
1046 tab = tcc_realloc(s1->sym_attrs, n * sizeof(*s1->sym_attrs));
1047 s1->sym_attrs = tab;
1048 memset(s1->sym_attrs + s1->nb_sym_attrs, 0,
1049 (n - s1->nb_sym_attrs) * sizeof(*s1->sym_attrs));
1050 s1->nb_sym_attrs = n;
1051 }
1052 return &s1->sym_attrs[index];
1053 }
1054
1055 static void build_got(TCCState *s1)
1056 {
1057 unsigned char *ptr;
1058
1059 /* if no got, then create it */
1060 s1->got = new_section(s1, ".got", SHT_PROGBITS, SHF_ALLOC | SHF_WRITE);
1061 s1->got->sh_entsize = 4;
1062 add_elf_sym(symtab_section, 0, 4, ELFW(ST_INFO)(STB_GLOBAL, STT_OBJECT),
1063 0, s1->got->sh_num, "_GLOBAL_OFFSET_TABLE_");
1064 ptr = section_ptr_add(s1->got, 3 * PTR_SIZE);
1065 #if PTR_SIZE == 4
1066 /* keep space for _DYNAMIC pointer, if present */
1067 write32le(ptr, 0);
1068 /* two dummy got entries */
1069 write32le(ptr + 4, 0);
1070 write32le(ptr + 8, 0);
1071 #else
1072 /* keep space for _DYNAMIC pointer, if present */
1073 write32le(ptr, 0);
1074 write32le(ptr + 4, 0);
1075 /* two dummy got entries */
1076 write32le(ptr + 8, 0);
1077 write32le(ptr + 12, 0);
1078 write32le(ptr + 16, 0);
1079 write32le(ptr + 20, 0);
1080 #endif
1081 }
1082
1083 /* put a got or plt entry corresponding to a symbol in symtab_section. 'size'
1084 and 'info' can be modifed if more precise info comes from the DLL.
1085 Returns offset of GOT or PLT slot. */
1086 static unsigned long put_got_entry(TCCState *s1,
1087 int reloc_type, unsigned long size, int info,
1088 int sym_index)
1089 {
1090 int index, need_plt_entry;
1091 const char *name;
1092 ElfW(Sym) *sym;
1093 unsigned long offset;
1094 int *ptr;
1095 struct sym_attr *symattr;
1096
1097 if (!s1->got)
1098 build_got(s1);
1099
1100 need_plt_entry =
1101 #ifdef TCC_TARGET_X86_64
1102 (reloc_type == R_X86_64_JUMP_SLOT);
1103 #elif defined(TCC_TARGET_I386)
1104 (reloc_type == R_386_JMP_SLOT);
1105 #elif defined(TCC_TARGET_ARM)
1106 (reloc_type == R_ARM_JUMP_SLOT);
1107 #elif defined(TCC_TARGET_ARM64)
1108 (reloc_type == R_AARCH64_JUMP_SLOT);
1109 #else
1110 0;
1111 #endif
1112
1113 if (need_plt_entry && !s1->plt) {
1114 /* add PLT */
1115 s1->plt = new_section(s1, ".plt", SHT_PROGBITS,
1116 SHF_ALLOC | SHF_EXECINSTR);
1117 s1->plt->sh_entsize = 4;
1118 }
1119
1120 /* If a got/plt entry already exists for that symbol, no need to add one */
1121 if (sym_index < s1->nb_sym_attrs) {
1122 if (need_plt_entry && s1->sym_attrs[sym_index].plt_offset)
1123 return s1->sym_attrs[sym_index].plt_offset;
1124 else if (!need_plt_entry && s1->sym_attrs[sym_index].got_offset)
1125 return s1->sym_attrs[sym_index].got_offset;
1126 }
1127
1128 symattr = alloc_sym_attr(s1, sym_index);
1129
1130 /* Only store the GOT offset if it's not generated for the PLT entry. */
1131 if (!need_plt_entry)
1132 symattr->got_offset = s1->got->data_offset;
1133
1134 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1135 name = (char *) symtab_section->link->data + sym->st_name;
1136 offset = sym->st_value;
1137 #if defined(TCC_TARGET_I386) || defined(TCC_TARGET_X86_64)
1138 if (need_plt_entry) {
1139 Section *plt;
1140 uint8_t *p;
1141 int modrm;
1142 unsigned long relofs;
1143
1144 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
1145 modrm = 0x25;
1146 #else
1147 /* if we build a DLL, we add a %ebx offset */
1148 if (s1->output_type == TCC_OUTPUT_DLL)
1149 modrm = 0xa3;
1150 else
1151 modrm = 0x25;
1152 #endif
1153
1154 /* add a PLT entry */
1155 plt = s1->plt;
1156 if (plt->data_offset == 0) {
1157 /* first plt entry */
1158 p = section_ptr_add(plt, 16);
1159 p[0] = 0xff; /* pushl got + PTR_SIZE */
1160 p[1] = modrm + 0x10;
1161 write32le(p + 2, PTR_SIZE);
1162 p[6] = 0xff; /* jmp *(got + PTR_SIZE * 2) */
1163 p[7] = modrm;
1164 write32le(p + 8, PTR_SIZE * 2);
1165 }
1166
1167 /* The PLT slot refers to the relocation entry it needs
1168 via offset. The reloc entry is created below, so its
1169 offset is the current data_offset. */
1170 relofs = s1->got->reloc ? s1->got->reloc->data_offset : 0;
1171 symattr->plt_offset = plt->data_offset;
1172 p = section_ptr_add(plt, 16);
1173 p[0] = 0xff; /* jmp *(got + x) */
1174 p[1] = modrm;
1175 write32le(p + 2, s1->got->data_offset);
1176 p[6] = 0x68; /* push $xxx */
1177 #ifdef TCC_TARGET_X86_64
1178 /* On x86-64, the relocation is referred to by _index_. */
1179 write32le(p + 7, relofs / sizeof (ElfW_Rel));
1180 #else
1181 write32le(p + 7, relofs);
1182 #endif
1183 p[11] = 0xe9; /* jmp plt_start */
1184 write32le(p + 12, -(plt->data_offset));
1185
1186 /* If this was an UNDEF symbol set the offset in the
1187 dynsymtab to the PLT slot, so that PC32 relocs to it
1188 can be resolved. */
1189 if (sym->st_shndx == SHN_UNDEF)
1190 offset = plt->data_offset - 16;
1191 }
1192 #elif defined(TCC_TARGET_ARM)
1193 if (need_plt_entry) {
1194 Section *plt;
1195 uint8_t *p;
1196
1197 /* if we build a DLL, we add a %ebx offset */
1198 if (s1->output_type == TCC_OUTPUT_DLL)
1199 tcc_error("DLLs unimplemented!");
1200
1201 /* add a PLT entry */
1202 plt = s1->plt;
1203 if (plt->data_offset == 0) {
1204 /* first plt entry */
1205 p = section_ptr_add(plt, 16);
1206 write32le(p, 0xe52de004); /* push {lr} */
1207 write32le(p+4, 0xe59fe010); /* ldr lr, [pc, #16] */
1208 write32le(p+8, 0xe08fe00e); /* add lr, pc, lr */
1209 write32le(p+12, 0xe5bef008); /* ldr pc, [lr, #8]! */
1210 }
1211
1212 symattr->plt_offset = plt->data_offset;
1213 if (symattr->plt_thumb_stub) {
1214 p = section_ptr_add(plt, 20);
1215 write32le(p, 0x4778); /* bx pc */
1216 write32le(p+2, 0x46c0); /* nop */
1217 p += 4;
1218 } else
1219 p = section_ptr_add(plt, 16);
1220 write32le(p, 0xe59fc004); /* ldr ip, [pc, #4] ; GOT entry offset */
1221 write32le(p+4, 0xe08fc00c); /* add ip, pc, ip ; addr of GOT entry */
1222 write32le(p+8, 0xe59cf000); /* ldr pc, [ip] ; jump to GOT entry */
1223 write32le(p+12, s1->got->data_offset); /* GOT entry off once patched */
1224
1225 /* the symbol is modified so that it will be relocated to
1226 the PLT */
1227 if (sym->st_shndx == SHN_UNDEF)
1228 offset = plt->data_offset - 16;
1229 }
1230 #elif defined(TCC_TARGET_ARM64)
1231 if (need_plt_entry) {
1232 Section *plt;
1233 uint8_t *p;
1234
1235 if (s1->output_type == TCC_OUTPUT_DLL)
1236 tcc_error("DLLs unimplemented!");
1237
1238 plt = s1->plt;
1239 if (plt->data_offset == 0)
1240 section_ptr_add(plt, 32);
1241 symattr->plt_offset = plt->data_offset;
1242 p = section_ptr_add(plt, 16);
1243 write32le(p, s1->got->data_offset);
1244 write32le(p + 4, (uint64_t)s1->got->data_offset >> 32);
1245
1246 if (sym->st_shndx == SHN_UNDEF)
1247 offset = plt->data_offset - 16;
1248 }
1249 #elif defined(TCC_TARGET_C67)
1250 if (s1->dynsym) {
1251 tcc_error("C67 got not implemented");
1252 }
1253 #else
1254 #error unsupported CPU
1255 #endif
1256 if (s1->dynsym) {
1257 /* XXX This might generate multiple syms for name. */
1258 index = put_elf_sym(s1->dynsym, offset,
1259 size, info, 0, sym->st_shndx, name);
1260 /* Create the relocation (it's against the GOT for PLT
1261 and GOT relocs). */
1262 put_elf_reloc(s1->dynsym, s1->got,
1263 s1->got->data_offset,
1264 reloc_type, index);
1265 } else {
1266 /* Without .dynsym (i.e. static link or memory output) we
1267 still need relocs against the generated got, so as to fill
1268 the entries with the symbol values (determined later). */
1269 put_elf_reloc(symtab_section, s1->got,
1270 s1->got->data_offset,
1271 reloc_type, sym_index);
1272 }
1273 /* And now create the GOT slot itself. */
1274 ptr = section_ptr_add(s1->got, PTR_SIZE);
1275 *ptr = 0;
1276 if (need_plt_entry)
1277 return symattr->plt_offset;
1278 else
1279 return symattr->got_offset;
1280 }
1281
1282 /* build GOT and PLT entries */
1283 ST_FUNC void build_got_entries(TCCState *s1)
1284 {
1285 Section *s;
1286 ElfW_Rel *rel;
1287 ElfW(Sym) *sym;
1288 int i, type, reloc_type, sym_index;
1289
1290 for(i = 1; i < s1->nb_sections; i++) {
1291 s = s1->sections[i];
1292 if (s->sh_type != SHT_RELX)
1293 continue;
1294 /* no need to handle got relocations */
1295 if (s->link != symtab_section)
1296 continue;
1297 for_each_elem(s, 0, rel, ElfW_Rel) {
1298 type = ELFW(R_TYPE)(rel->r_info);
1299 switch(type) {
1300 #if defined(TCC_TARGET_I386)
1301 case R_386_GOT32:
1302 case R_386_GOT32X:
1303 case R_386_GOTOFF:
1304 case R_386_GOTPC:
1305 case R_386_PLT32:
1306 if (!s1->got)
1307 build_got(s1);
1308 if (type == R_386_GOT32 || type == R_386_GOT32X ||
1309 type == R_386_PLT32) {
1310 sym_index = ELFW(R_SYM)(rel->r_info);
1311 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1312 /* look at the symbol got offset. If none, then add one */
1313 if (type == R_386_GOT32 || type == R_386_GOT32X)
1314 reloc_type = R_386_GLOB_DAT;
1315 else
1316 reloc_type = R_386_JMP_SLOT;
1317 put_got_entry(s1, reloc_type, sym->st_size, sym->st_info,
1318 sym_index);
1319 }
1320 break;
1321 #elif defined(TCC_TARGET_ARM)
1322 case R_ARM_PC24:
1323 case R_ARM_CALL:
1324 case R_ARM_JUMP24:
1325 case R_ARM_GOT32:
1326 case R_ARM_GOTOFF:
1327 case R_ARM_GOTPC:
1328 case R_ARM_PLT32:
1329 if (!s1->got)
1330 build_got(s1);
1331 sym_index = ELFW(R_SYM)(rel->r_info);
1332 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1333 if (type != R_ARM_GOTOFF && type != R_ARM_GOTPC
1334 && sym->st_shndx == SHN_UNDEF) {
1335 unsigned long ofs;
1336 /* look at the symbol got offset. If none, then add one */
1337 if (type == R_ARM_GOT32)
1338 reloc_type = R_ARM_GLOB_DAT;
1339 else
1340 reloc_type = R_ARM_JUMP_SLOT;
1341 ofs = put_got_entry(s1, reloc_type, sym->st_size,
1342 sym->st_info, sym_index);
1343 #ifdef DEBUG_RELOC
1344 printf ("maybegot: %s, %d, %d --> ofs=0x%x\n",
1345 (char *) symtab_section->link->data + sym->st_name,
1346 type, sym->st_shndx, ofs);
1347 #endif
1348 if (type != R_ARM_GOT32) {
1349 addr_t *ptr = (addr_t*)(s1->sections[s->sh_info]->data
1350 + rel->r_offset);
1351 /* x must be signed! */
1352 int x = *ptr & 0xffffff;
1353 x = (x << 8) >> 8;
1354 x <<= 2;
1355 x += ofs;
1356 x >>= 2;
1357 #ifdef DEBUG_RELOC
1358 printf ("insn=0x%x --> 0x%x (x==0x%x)\n", *ptr,
1359 (*ptr & 0xff000000) | x, x);
1360 #endif
1361 *ptr = (*ptr & 0xff000000) | x;
1362 }
1363 }
1364 break;
1365 case R_ARM_THM_JUMP24:
1366 sym_index = ELFW(R_SYM)(rel->r_info);
1367 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1368 /* We are relocating a jump from thumb code to arm code */
1369 if (sym->st_shndx != SHN_UNDEF && !(sym->st_value & 1)) {
1370 int index;
1371 uint8_t *p;
1372 char *name, buf[1024];
1373 Section *text_section;
1374
1375 name = (char *) symtab_section->link->data + sym->st_name;
1376 text_section = s1->sections[sym->st_shndx];
1377 /* Modify reloc to target a thumb stub to switch to ARM */
1378 snprintf(buf, sizeof(buf), "%s_from_thumb", name);
1379 index = put_elf_sym(symtab_section,
1380 text_section->data_offset + 1,
1381 sym->st_size, sym->st_info, 0,
1382 sym->st_shndx, buf);
1383 rel->r_info = ELFW(R_INFO)(index, type);
1384 /* Create a thumb stub fonction to switch to ARM mode */
1385 put_elf_reloc(symtab_section, text_section,
1386 text_section->data_offset + 4, R_ARM_JUMP24,
1387 sym_index);
1388 p = section_ptr_add(text_section, 8);
1389 write32le(p, 0x4778); /* bx pc */
1390 write32le(p+2, 0x46c0); /* nop */
1391 write32le(p+4, 0xeafffffe); /* b $sym */
1392 }
1393 #elif defined(TCC_TARGET_ARM64)
1394 //xx Other cases may be required here:
1395 case R_AARCH64_ADR_GOT_PAGE:
1396 case R_AARCH64_LD64_GOT_LO12_NC:
1397 if (!s1->got)
1398 build_got(s1);
1399 sym_index = ELFW(R_SYM)(rel->r_info);
1400 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1401 reloc_type = R_AARCH64_GLOB_DAT;
1402 put_got_entry(s1, reloc_type, sym->st_size, sym->st_info,
1403 sym_index);
1404 break;
1405
1406 case R_AARCH64_JUMP26:
1407 case R_AARCH64_CALL26:
1408 if (!s1->got)
1409 build_got(s1);
1410 sym_index = ELFW(R_SYM)(rel->r_info);
1411 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1412 if (sym->st_shndx == SHN_UNDEF) {
1413 unsigned long ofs;
1414 reloc_type = R_AARCH64_JUMP_SLOT;
1415 ofs = put_got_entry(s1, reloc_type, sym->st_size,
1416 sym->st_info, sym_index);
1417 /* We store the place of the generated PLT slot
1418 in our addend. */
1419 rel->r_addend += ofs;
1420 }
1421 break;
1422 #elif defined(TCC_TARGET_C67)
1423 case R_C60_GOT32:
1424 case R_C60_GOTOFF:
1425 case R_C60_GOTPC:
1426 case R_C60_PLT32:
1427 if (!s1->got)
1428 build_got(s1);
1429 if (type == R_C60_GOT32 || type == R_C60_PLT32) {
1430 sym_index = ELFW(R_SYM)(rel->r_info);
1431 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1432 /* look at the symbol got offset. If none, then add one */
1433 if (type == R_C60_GOT32)
1434 reloc_type = R_C60_GLOB_DAT;
1435 else
1436 reloc_type = R_C60_JMP_SLOT;
1437 put_got_entry(s1, reloc_type, sym->st_size, sym->st_info,
1438 sym_index);
1439 }
1440 break;
1441 #elif defined(TCC_TARGET_X86_64)
1442 case R_X86_64_GOT32:
1443 case R_X86_64_GOTTPOFF:
1444 case R_X86_64_GOTPCREL:
1445 case R_X86_64_GOTPCRELX:
1446 case R_X86_64_REX_GOTPCRELX:
1447 case R_X86_64_PLT32:
1448 sym_index = ELFW(R_SYM)(rel->r_info);
1449 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1450 if (type == R_X86_64_PLT32 &&
1451 ELFW(ST_VISIBILITY)(sym->st_other) != STV_DEFAULT)
1452 {
1453 rel->r_info = ELFW(R_INFO)(sym_index, R_X86_64_PC32);
1454 break;
1455 }
1456
1457 if (!s1->got) {
1458 build_got(s1);
1459 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1460 }
1461 if (type == R_X86_64_GOT32 || type == R_X86_64_GOTPCREL ||
1462 type == R_X86_64_GOTPCRELX ||
1463 type == R_X86_64_REX_GOTPCRELX ||
1464 type == R_X86_64_PLT32) {
1465 unsigned long ofs;
1466 /* look at the symbol got offset. If none, then add one */
1467 if (type == R_X86_64_PLT32)
1468 reloc_type = R_X86_64_JUMP_SLOT;
1469 else
1470 reloc_type = R_X86_64_GLOB_DAT;
1471 ofs = put_got_entry(s1, reloc_type, sym->st_size,
1472 sym->st_info, sym_index);
1473 if (type == R_X86_64_PLT32)
1474 /* We store the place of the generated PLT slot
1475 in our addend. */
1476 rel->r_addend += ofs;
1477 }
1478 break;
1479 #else
1480 #error unsupported CPU
1481 #endif
1482 default:
1483 break;
1484 }
1485 }
1486 }
1487 }
1488
1489 ST_FUNC Section *new_symtab(TCCState *s1,
1490 const char *symtab_name, int sh_type, int sh_flags,
1491 const char *strtab_name,
1492 const char *hash_name, int hash_sh_flags)
1493 {
1494 Section *symtab, *strtab, *hash;
1495 int *ptr, nb_buckets;
1496
1497 symtab = new_section(s1, symtab_name, sh_type, sh_flags);
1498 symtab->sh_entsize = sizeof(ElfW(Sym));
1499 strtab = new_section(s1, strtab_name, SHT_STRTAB, sh_flags);
1500 put_elf_str(strtab, "");
1501 symtab->link = strtab;
1502 put_elf_sym(symtab, 0, 0, 0, 0, 0, NULL);
1503
1504 nb_buckets = 1;
1505
1506 hash = new_section(s1, hash_name, SHT_HASH, hash_sh_flags);
1507 hash->sh_entsize = sizeof(int);
1508 symtab->hash = hash;
1509 hash->link = symtab;
1510
1511 ptr = section_ptr_add(hash, (2 + nb_buckets + 1) * sizeof(int));
1512 ptr[0] = nb_buckets;
1513 ptr[1] = 1;
1514 memset(ptr + 2, 0, (nb_buckets + 1) * sizeof(int));
1515 return symtab;
1516 }
1517
1518 /* put dynamic tag */
1519 static void put_dt(Section *dynamic, int dt, addr_t val)
1520 {
1521 ElfW(Dyn) *dyn;
1522 dyn = section_ptr_add(dynamic, sizeof(ElfW(Dyn)));
1523 dyn->d_tag = dt;
1524 dyn->d_un.d_val = val;
1525 }
1526
1527 static void add_init_array_defines(TCCState *s1, const char *section_name)
1528 {
1529 Section *s;
1530 long end_offset;
1531 char sym_start[1024];
1532 char sym_end[1024];
1533
1534 snprintf(sym_start, sizeof(sym_start), "__%s_start", section_name + 1);
1535 snprintf(sym_end, sizeof(sym_end), "__%s_end", section_name + 1);
1536
1537 s = find_section(s1, section_name);
1538 if (!s) {
1539 end_offset = 0;
1540 s = data_section;
1541 } else {
1542 end_offset = s->data_offset;
1543 }
1544
1545 add_elf_sym(symtab_section,
1546 0, 0,
1547 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1548 s->sh_num, sym_start);
1549 add_elf_sym(symtab_section,
1550 end_offset, 0,
1551 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1552 s->sh_num, sym_end);
1553 }
1554
1555 static int tcc_add_support(TCCState *s1, const char *filename)
1556 {
1557 char buf[1024];
1558 snprintf(buf, sizeof(buf), "%s/%s/%s", s1->tcc_lib_path,
1559 /* an cpu specific path inside tcc_lib_path, mainly for keeping libtcc1.a */
1560 #ifdef TCC_TARGET_I386
1561 "i386"
1562 #endif
1563 #ifdef TCC_TARGET_X86_64
1564 "x86-64"
1565 #endif
1566 #ifdef TCC_TARGET_ARM
1567 "arm"
1568 #endif
1569 #ifdef TCC_TARGET_ARM64
1570 "arm64"
1571 #endif
1572 #ifdef TCC_TARGET_C67
1573 "C67"
1574 #endif
1575 ,filename);
1576 return tcc_add_file(s1, buf);
1577 }
1578
1579 ST_FUNC void tcc_add_bcheck(TCCState *s1)
1580 {
1581 #ifdef CONFIG_TCC_BCHECK
1582 addr_t *ptr;
1583
1584 if (0 == s1->do_bounds_check)
1585 return;
1586
1587 /* XXX: add an object file to do that */
1588 ptr = section_ptr_add(bounds_section, sizeof(*ptr));
1589 *ptr = 0;
1590 add_elf_sym(symtab_section, 0, 0,
1591 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1592 bounds_section->sh_num, "__bounds_start");
1593 if (s1->output_type != TCC_OUTPUT_MEMORY) {
1594 /* add 'call __bound_init()' in .init section */
1595
1596 /* XXX not called on MSYS, reason is unknown. For this
1597 case a call to __bound_init is performed in bcheck.c
1598 when __bound_ptr_add, __bound_new_region,
1599 __bound_delete_region called */
1600
1601 int sym_index = find_elf_sym(symtab_section, "__bound_init");
1602 if (sym_index) {
1603 Section *init_section = find_section(s1, ".init");
1604 unsigned char *pinit = section_ptr_add(init_section, 5);
1605 pinit[0] = 0xe8;
1606 write32le(pinit + 1, -4);
1607 put_elf_reloc(symtab_section, init_section,
1608 init_section->data_offset - 4, R_386_PC32, sym_index);
1609 }
1610 else
1611 tcc_warning("__bound_init not defined");
1612 }
1613 #endif
1614 }
1615
1616 /* add tcc runtime libraries */
1617 ST_FUNC void tcc_add_runtime(TCCState *s1)
1618 {
1619 tcc_add_pragma_libs(s1);
1620
1621 /* add libc */
1622 if (!s1->nostdlib) {
1623 tcc_add_library(s1, "c");
1624 #ifdef CONFIG_USE_LIBGCC
1625 if (!s1->static_link) {
1626 tcc_add_file(s1, TCC_LIBGCC);
1627 }
1628 #endif
1629 tcc_add_support(s1, "libtcc1.a");
1630 }
1631
1632 /* tcc_add_bcheck tries to relocate a call to __bound_init in _init so
1633 libtcc1.a must be loaded before for __bound_init to be defined and
1634 crtn.o must be loaded after to not finalize _init too early. */
1635 tcc_add_bcheck(s1);
1636
1637 if (!s1->nostdlib) {
1638 /* add crt end if not memory output */
1639 if (s1->output_type != TCC_OUTPUT_MEMORY)
1640 tcc_add_crt(s1, "crtn.o");
1641 }
1642 }
1643
1644 /* add various standard linker symbols (must be done after the
1645 sections are filled (for example after allocating common
1646 symbols)) */
1647 ST_FUNC void tcc_add_linker_symbols(TCCState *s1)
1648 {
1649 char buf[1024];
1650 int i;
1651 Section *s;
1652
1653 add_elf_sym(symtab_section,
1654 text_section->data_offset, 0,
1655 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1656 text_section->sh_num, "_etext");
1657 add_elf_sym(symtab_section,
1658 data_section->data_offset, 0,
1659 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1660 data_section->sh_num, "_edata");
1661 add_elf_sym(symtab_section,
1662 bss_section->data_offset, 0,
1663 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1664 bss_section->sh_num, "_end");
1665 /* horrible new standard ldscript defines */
1666 add_init_array_defines(s1, ".preinit_array");
1667 add_init_array_defines(s1, ".init_array");
1668 add_init_array_defines(s1, ".fini_array");
1669
1670 /* add start and stop symbols for sections whose name can be
1671 expressed in C */
1672 for(i = 1; i < s1->nb_sections; i++) {
1673 s = s1->sections[i];
1674 if (s->sh_type == SHT_PROGBITS &&
1675 (s->sh_flags & SHF_ALLOC)) {
1676 const char *p;
1677 int ch;
1678
1679 /* check if section name can be expressed in C */
1680 p = s->name;
1681 for(;;) {
1682 ch = *p;
1683 if (!ch)
1684 break;
1685 if (!isid(ch) && !isnum(ch))
1686 goto next_sec;
1687 p++;
1688 }
1689 snprintf(buf, sizeof(buf), "__start_%s", s->name);
1690 add_elf_sym(symtab_section,
1691 0, 0,
1692 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1693 s->sh_num, buf);
1694 snprintf(buf, sizeof(buf), "__stop_%s", s->name);
1695 add_elf_sym(symtab_section,
1696 s->data_offset, 0,
1697 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1698 s->sh_num, buf);
1699 }
1700 next_sec: ;
1701 }
1702 }
1703
1704 static void tcc_output_binary(TCCState *s1, FILE *f,
1705 const int *sec_order)
1706 {
1707 Section *s;
1708 int i, offset, size;
1709
1710 offset = 0;
1711 for(i=1;i<s1->nb_sections;i++) {
1712 s = s1->sections[sec_order[i]];
1713 if (s->sh_type != SHT_NOBITS &&
1714 (s->sh_flags & SHF_ALLOC)) {
1715 while (offset < s->sh_offset) {
1716 fputc(0, f);
1717 offset++;
1718 }
1719 size = s->sh_size;
1720 fwrite(s->data, 1, size, f);
1721 offset += size;
1722 }
1723 }
1724 }
1725
1726 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1727 #define HAVE_PHDR 1
1728 #define EXTRA_RELITEMS 14
1729
1730 /* move the relocation value from .dynsym to .got */
1731 static void patch_dynsym_undef(TCCState *s1, Section *s)
1732 {
1733 uint32_t *gotd = (void *)s1->got->data;
1734 ElfW(Sym) *sym;
1735
1736 gotd += 3; /* dummy entries in .got */
1737 /* relocate symbols in .dynsym */
1738 for_each_elem(s, 1, sym, ElfW(Sym)) {
1739 if (sym->st_shndx == SHN_UNDEF) {
1740 *gotd++ = sym->st_value + 6; /* XXX 6 is magic ? */
1741 sym->st_value = 0;
1742 }
1743 }
1744 }
1745 #else
1746 #define HAVE_PHDR 1
1747 #define EXTRA_RELITEMS 9
1748
1749 /* zero plt offsets of weak symbols in .dynsym */
1750 static void patch_dynsym_undef(TCCState *s1, Section *s)
1751 {
1752 ElfW(Sym) *sym;
1753
1754 for_each_elem(s, 1, sym, ElfW(Sym))
1755 if (sym->st_shndx == SHN_UNDEF && ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
1756 sym->st_value = 0;
1757 }
1758 #endif
1759
1760 ST_FUNC void fill_got_entry(TCCState *s1, ElfW_Rel *rel)
1761 {
1762 int sym_index = ELFW(R_SYM) (rel->r_info);
1763 ElfW(Sym) *sym = &((ElfW(Sym) *) symtab_section->data)[sym_index];
1764 unsigned long offset;
1765
1766 if (sym_index >= s1->nb_sym_attrs)
1767 return;
1768 offset = s1->sym_attrs[sym_index].got_offset;
1769 section_reserve(s1->got, offset + PTR_SIZE);
1770 #ifdef TCC_TARGET_X86_64
1771 /* only works for x86-64 */
1772 write32le(s1->got->data + offset + 4, sym->st_value >> 32);
1773 #endif
1774 write32le(s1->got->data + offset, sym->st_value & 0xffffffff);
1775 }
1776
1777 /* Perform relocation to GOT or PLT entries */
1778 ST_FUNC void fill_got(TCCState *s1)
1779 {
1780 Section *s;
1781 ElfW_Rel *rel;
1782 int i;
1783
1784 for(i = 1; i < s1->nb_sections; i++) {
1785 s = s1->sections[i];
1786 if (s->sh_type != SHT_RELX)
1787 continue;
1788 /* no need to handle got relocations */
1789 if (s->link != symtab_section)
1790 continue;
1791 for_each_elem(s, 0, rel, ElfW_Rel) {
1792 switch (ELFW(R_TYPE) (rel->r_info)) {
1793 case R_X86_64_GOT32:
1794 case R_X86_64_GOTPCREL:
1795 case R_X86_64_GOTPCRELX:
1796 case R_X86_64_REX_GOTPCRELX:
1797 case R_X86_64_PLT32:
1798 fill_got_entry(s1, rel);
1799 break;
1800 }
1801 }
1802 }
1803 }
1804
1805 /* Bind symbols of executable: resolve undefined symbols from exported symbols
1806 in shared libraries and export non local defined symbols to shared libraries
1807 if -rdynamic switch was given on command line */
1808 static void bind_exe_dynsyms(TCCState *s1)
1809 {
1810 const char *name;
1811 int sym_index, index;
1812 ElfW(Sym) *sym, *esym;
1813 int type;
1814
1815 /* Resolve undefined symbols from dynamic symbols. When there is a match:
1816 - if STT_FUNC or STT_GNU_IFUNC symbol -> add it in PLT
1817 - if STT_OBJECT symbol -> add it in .bss section with suitable reloc */
1818 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
1819 if (sym->st_shndx == SHN_UNDEF) {
1820 name = (char *) symtab_section->link->data + sym->st_name;
1821 sym_index = find_elf_sym(s1->dynsymtab_section, name);
1822 if (sym_index) {
1823 esym = &((ElfW(Sym) *)s1->dynsymtab_section->data)[sym_index];
1824 type = ELFW(ST_TYPE)(esym->st_info);
1825 if ((type == STT_FUNC) || (type == STT_GNU_IFUNC)) {
1826 /* Indirect functions shall have STT_FUNC type in executable
1827 * dynsym section. Indeed, a dlsym call following a lazy
1828 * resolution would pick the symbol value from the
1829 * executable dynsym entry which would contain the address
1830 * of the function wanted by the caller of dlsym instead of
1831 * the address of the function that would return that
1832 * address */
1833 put_got_entry(s1, R_JMP_SLOT, esym->st_size,
1834 ELFW(ST_INFO)(STB_GLOBAL,STT_FUNC),
1835 sym - (ElfW(Sym) *)symtab_section->data);
1836 } else if (type == STT_OBJECT) {
1837 unsigned long offset;
1838 ElfW(Sym) *dynsym;
1839 offset = bss_section->data_offset;
1840 /* XXX: which alignment ? */
1841 offset = (offset + 16 - 1) & -16;
1842 index = put_elf_sym(s1->dynsym, offset, esym->st_size,
1843 esym->st_info, 0, bss_section->sh_num,
1844 name);
1845 /* Ensure R_COPY works for weak symbol aliases */
1846 if (ELFW(ST_BIND)(esym->st_info) == STB_WEAK) {
1847 for_each_elem(s1->dynsymtab_section, 1, dynsym, ElfW(Sym)) {
1848 if ((dynsym->st_value == esym->st_value)
1849 && (ELFW(ST_BIND)(dynsym->st_info) == STB_GLOBAL)) {
1850 char *dynname = (char *) s1->dynsymtab_section->link->data
1851 + dynsym->st_name;
1852 put_elf_sym(s1->dynsym, offset, dynsym->st_size,
1853 dynsym->st_info, 0,
1854 bss_section->sh_num, dynname);
1855 break;
1856 }
1857 }
1858 }
1859 put_elf_reloc(s1->dynsym, bss_section,
1860 offset, R_COPY, index);
1861 offset += esym->st_size;
1862 bss_section->data_offset = offset;
1863 }
1864 } else {
1865 /* STB_WEAK undefined symbols are accepted */
1866 /* XXX: _fp_hw seems to be part of the ABI, so we ignore it */
1867 if (ELFW(ST_BIND)(sym->st_info) == STB_WEAK ||
1868 !strcmp(name, "_fp_hw")) {
1869 } else {
1870 tcc_error_noabort("undefined symbol '%s'", name);
1871 }
1872 }
1873 } else if (s1->rdynamic && ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
1874 /* if -rdynamic option, then export all non local symbols */
1875 name = (char *) symtab_section->link->data + sym->st_name;
1876 put_elf_sym(s1->dynsym, sym->st_value, sym->st_size, sym->st_info,
1877 0, sym->st_shndx, name);
1878 }
1879 }
1880 }
1881
1882 /* Bind symbols of libraries: export non local symbols of executable that
1883 resolve undefined symbols of shared libraries */
1884 static void bind_libs_dynsyms(TCCState *s1)
1885 {
1886 const char *name;
1887 int sym_index;
1888 ElfW(Sym) *sym, *esym;
1889
1890 /* now look at unresolved dynamic symbols and export
1891 corresponding symbol */
1892 for_each_elem(s1->dynsymtab_section, 1, esym, ElfW(Sym)) {
1893 name = (char *) s1->dynsymtab_section->link->data + esym->st_name;
1894 sym_index = find_elf_sym(symtab_section, name);
1895 if (sym_index) {
1896 /* XXX: avoid adding a symbol if already present because of
1897 -rdynamic ? */
1898 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1899 if (sym->st_shndx != SHN_UNDEF)
1900 put_elf_sym(s1->dynsym, sym->st_value, sym->st_size,
1901 sym->st_info, 0, sym->st_shndx, name);
1902 } else if (esym->st_shndx == SHN_UNDEF) {
1903 /* weak symbols can stay undefined */
1904 if (ELFW(ST_BIND)(esym->st_info) != STB_WEAK)
1905 tcc_warning("undefined dynamic symbol '%s'", name);
1906 }
1907 }
1908 }
1909
1910 /* Export all non local symbols (for shared libraries) */
1911 static void export_global_syms(TCCState *s1)
1912 {
1913 int nb_syms, dynindex, index;
1914 const char *name;
1915 ElfW(Sym) *sym;
1916
1917 nb_syms = symtab_section->data_offset / sizeof(ElfW(Sym));
1918 s1->symtab_to_dynsym = tcc_mallocz(sizeof(int) * nb_syms);
1919 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
1920 if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
1921 name = (char *) symtab_section->link->data + sym->st_name;
1922 dynindex = put_elf_sym(s1->dynsym, sym->st_value, sym->st_size,
1923 sym->st_info, 0, sym->st_shndx, name);
1924 index = sym - (ElfW(Sym) *) symtab_section->data;
1925 s1->symtab_to_dynsym[index] = dynindex;
1926 }
1927 }
1928 }
1929
1930 /* relocate the PLT: compute addresses and offsets in the PLT now that final
1931 address for PLT and GOT are known (see fill_program_header) */
1932 ST_FUNC void relocate_plt(TCCState *s1)
1933 {
1934 uint8_t *p, *p_end;
1935
1936 if (!s1->plt)
1937 return;
1938
1939 p = s1->plt->data;
1940 p_end = p + s1->plt->data_offset;
1941 if (p < p_end) {
1942 #if defined(TCC_TARGET_I386)
1943 write32le(p + 2, read32le(p + 2) + s1->got->sh_addr);
1944 write32le(p + 8, read32le(p + 8) + s1->got->sh_addr);
1945 p += 16;
1946 while (p < p_end) {
1947 write32le(p + 2, read32le(p + 2) + s1->got->sh_addr);
1948 p += 16;
1949 }
1950 #elif defined(TCC_TARGET_X86_64)
1951 int x = s1->got->sh_addr - s1->plt->sh_addr - 6;
1952 write32le(p + 2, read32le(p + 2) + x);
1953 write32le(p + 8, read32le(p + 8) + x - 6);
1954 p += 16;
1955 while (p < p_end) {
1956 write32le(p + 2, read32le(p + 2) + x + s1->plt->data - p);
1957 p += 16;
1958 }
1959 #elif defined(TCC_TARGET_ARM)
1960 int x;
1961 x=s1->got->sh_addr - s1->plt->sh_addr - 12;
1962 p += 16;
1963 while (p < p_end) {
1964 if (read32le(p) == 0x46c04778) /* PLT Thumb stub present */
1965 p += 4;
1966 write32le(p + 12, x + read32le(p + 12) + s1->plt->data - p);
1967 p += 16;
1968 }
1969 #elif defined(TCC_TARGET_ARM64)
1970 uint64_t plt = s1->plt->sh_addr;
1971 uint64_t got = s1->got->sh_addr;
1972 uint64_t off = (got >> 12) - (plt >> 12);
1973 if ((off + ((uint32_t)1 << 20)) >> 21)
1974 tcc_error("Failed relocating PLT (off=0x%lx, got=0x%lx, plt=0x%lx)", off, got, plt);
1975 write32le(p, 0xa9bf7bf0); // stp x16,x30,[sp,#-16]!
1976 write32le(p + 4, (0x90000010 | // adrp x16,...
1977 (off & 0x1ffffc) << 3 | (off & 3) << 29));
1978 write32le(p + 8, (0xf9400211 | // ldr x17,[x16,#...]
1979 (got & 0xff8) << 7));
1980 write32le(p + 12, (0x91000210 | // add x16,x16,#...
1981 (got & 0xfff) << 10));
1982 write32le(p + 16, 0xd61f0220); // br x17
1983 write32le(p + 20, 0xd503201f); // nop
1984 write32le(p + 24, 0xd503201f); // nop
1985 write32le(p + 28, 0xd503201f); // nop
1986 p += 32;
1987 while (p < p_end) {
1988 uint64_t pc = plt + (p - s1->plt->data);
1989 uint64_t addr = got + read64le(p);
1990 uint64_t off = (addr >> 12) - (pc >> 12);
1991 if ((off + ((uint32_t)1 << 20)) >> 21)
1992 tcc_error("Failed relocating PLT (off=0x%lx, addr=0x%lx, pc=0x%lx)", off, addr, pc);
1993 write32le(p, (0x90000010 | // adrp x16,...
1994 (off & 0x1ffffc) << 3 | (off & 3) << 29));
1995 write32le(p + 4, (0xf9400211 | // ldr x17,[x16,#...]
1996 (addr & 0xff8) << 7));
1997 write32le(p + 8, (0x91000210 | // add x16,x16,#...
1998 (addr & 0xfff) << 10));
1999 write32le(p + 12, 0xd61f0220); // br x17
2000 p += 16;
2001 }
2002 #elif defined(TCC_TARGET_C67)
2003 /* XXX: TODO */
2004 #else
2005 #error unsupported CPU
2006 #endif
2007 }
2008 }
2009
2010 /* Allocate strings for section names and decide if an unallocated section
2011 should be output.
2012
2013 NOTE: the strsec section comes last, so its size is also correct ! */
2014 static void alloc_sec_names(TCCState *s1, int file_type, Section *strsec)
2015 {
2016 int i;
2017 Section *s;
2018
2019 /* Allocate strings for section names */
2020 for(i = 1; i < s1->nb_sections; i++) {
2021 s = s1->sections[i];
2022 s->sh_name = put_elf_str(strsec, s->name);
2023 /* when generating a DLL, we include relocations but we may
2024 patch them */
2025 if (file_type == TCC_OUTPUT_DLL &&
2026 s->sh_type == SHT_RELX &&
2027 !(s->sh_flags & SHF_ALLOC)) {
2028 /* gr: avoid bogus relocs for empty (debug) sections */
2029 if (s1->sections[s->sh_info]->sh_flags & SHF_ALLOC)
2030 prepare_dynamic_rel(s1, s);
2031 else if (s1->do_debug)
2032 s->sh_size = s->data_offset;
2033 } else if (s1->do_debug ||
2034 file_type == TCC_OUTPUT_OBJ ||
2035 file_type == TCC_OUTPUT_EXE ||
2036 (s->sh_flags & SHF_ALLOC) ||
2037 i == (s1->nb_sections - 1)) {
2038 /* we output all sections if debug or object file */
2039 s->sh_size = s->data_offset;
2040 }
2041 }
2042 }
2043
2044 /* Info to be copied in dynamic section */
2045 struct dyn_inf {
2046 Section *dynamic;
2047 Section *dynstr;
2048 unsigned long dyn_rel_off;
2049 addr_t rel_addr;
2050 addr_t rel_size;
2051 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2052 addr_t bss_addr;
2053 addr_t bss_size;
2054 #endif
2055 };
2056
2057 /* Assign sections to segments and decide how are sections laid out when loaded
2058 in memory. This function also fills corresponding program headers. */
2059 static int layout_sections(TCCState *s1, ElfW(Phdr) *phdr, int phnum,
2060 Section *interp, Section* strsec,
2061 struct dyn_inf *dyninf, int *sec_order)
2062 {
2063 int i, j, k, file_type, sh_order_index, file_offset;
2064 unsigned long s_align;
2065 long long tmp;
2066 addr_t addr;
2067 ElfW(Phdr) *ph;
2068 Section *s;
2069
2070 file_type = s1->output_type;
2071 sh_order_index = 1;
2072 file_offset = 0;
2073 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF)
2074 file_offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr));
2075 s_align = ELF_PAGE_SIZE;
2076 if (s1->section_align)
2077 s_align = s1->section_align;
2078
2079 if (phnum > 0) {
2080 if (s1->has_text_addr) {
2081 int a_offset, p_offset;
2082 addr = s1->text_addr;
2083 /* we ensure that (addr % ELF_PAGE_SIZE) == file_offset %
2084 ELF_PAGE_SIZE */
2085 a_offset = (int) (addr & (s_align - 1));
2086 p_offset = file_offset & (s_align - 1);
2087 if (a_offset < p_offset)
2088 a_offset += s_align;
2089 file_offset += (a_offset - p_offset);
2090 } else {
2091 if (file_type == TCC_OUTPUT_DLL)
2092 addr = 0;
2093 else
2094 addr = ELF_START_ADDR;
2095 /* compute address after headers */
2096 addr += (file_offset & (s_align - 1));
2097 }
2098
2099 ph = &phdr[0];
2100 /* Leave one program headers for the program interpreter and one for
2101 the program header table itself if needed. These are done later as
2102 they require section layout to be done first. */
2103 if (interp)
2104 ph += 1 + HAVE_PHDR;
2105
2106 /* dynamic relocation table information, for .dynamic section */
2107 dyninf->rel_addr = dyninf->rel_size = 0;
2108 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2109 dyninf->bss_addr = dyninf->bss_size = 0;
2110 #endif
2111
2112 for(j = 0; j < 2; j++) {
2113 ph->p_type = PT_LOAD;
2114 if (j == 0)
2115 ph->p_flags = PF_R | PF_X;
2116 else
2117 ph->p_flags = PF_R | PF_W;
2118 ph->p_align = s_align;
2119
2120 /* Decide the layout of sections loaded in memory. This must
2121 be done before program headers are filled since they contain
2122 info about the layout. We do the following ordering: interp,
2123 symbol tables, relocations, progbits, nobits */
2124 /* XXX: do faster and simpler sorting */
2125 for(k = 0; k < 5; k++) {
2126 for(i = 1; i < s1->nb_sections; i++) {
2127 s = s1->sections[i];
2128 /* compute if section should be included */
2129 if (j == 0) {
2130 if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) !=
2131 SHF_ALLOC)
2132 continue;
2133 } else {
2134 if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) !=
2135 (SHF_ALLOC | SHF_WRITE))
2136 continue;
2137 }
2138 if (s == interp) {
2139 if (k != 0)
2140 continue;
2141 } else if (s->sh_type == SHT_DYNSYM ||
2142 s->sh_type == SHT_STRTAB ||
2143 s->sh_type == SHT_HASH) {
2144 if (k != 1)
2145 continue;
2146 } else if (s->sh_type == SHT_RELX) {
2147 if (k != 2)
2148 continue;
2149 } else if (s->sh_type == SHT_NOBITS) {
2150 if (k != 4)
2151 continue;
2152 } else {
2153 if (k != 3)
2154 continue;
2155 }
2156 sec_order[sh_order_index++] = i;
2157
2158 /* section matches: we align it and add its size */
2159 tmp = addr;
2160 addr = (addr + s->sh_addralign - 1) &
2161 ~(s->sh_addralign - 1);
2162 file_offset += (int) ( addr - tmp );
2163 s->sh_offset = file_offset;
2164 s->sh_addr = addr;
2165
2166 /* update program header infos */
2167 if (ph->p_offset == 0) {
2168 ph->p_offset = file_offset;
2169 ph->p_vaddr = addr;
2170 ph->p_paddr = ph->p_vaddr;
2171 }
2172 /* update dynamic relocation infos */
2173 if (s->sh_type == SHT_RELX) {
2174 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2175 if (!strcmp(strsec->data + s->sh_name, ".rel.got")) {
2176 dyninf->rel_addr = addr;
2177 dyninf->rel_size += s->sh_size; /* XXX only first rel. */
2178 }
2179 if (!strcmp(strsec->data + s->sh_name, ".rel.bss")) {
2180 dyninf->bss_addr = addr;
2181 dyninf->bss_size = s->sh_size; /* XXX only first rel. */
2182 }
2183 #else
2184 if (dyninf->rel_size == 0)
2185 dyninf->rel_addr = addr;
2186 dyninf->rel_size += s->sh_size;
2187 #endif
2188 }
2189 addr += s->sh_size;
2190 if (s->sh_type != SHT_NOBITS)
2191 file_offset += s->sh_size;
2192 }
2193 }
2194 if (j == 0) {
2195 /* Make the first PT_LOAD segment include the program
2196 headers itself (and the ELF header as well), it'll
2197 come out with same memory use but will make various
2198 tools like binutils strip work better. */
2199 ph->p_offset &= ~(ph->p_align - 1);
2200 ph->p_vaddr &= ~(ph->p_align - 1);
2201 ph->p_paddr &= ~(ph->p_align - 1);
2202 }
2203 ph->p_filesz = file_offset - ph->p_offset;
2204 ph->p_memsz = addr - ph->p_vaddr;
2205 ph++;
2206 if (j == 0) {
2207 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF) {
2208 /* if in the middle of a page, we duplicate the page in
2209 memory so that one copy is RX and the other is RW */
2210 if ((addr & (s_align - 1)) != 0)
2211 addr += s_align;
2212 } else {
2213 addr = (addr + s_align - 1) & ~(s_align - 1);
2214 file_offset = (file_offset + s_align - 1) & ~(s_align - 1);
2215 }
2216 }
2217 }
2218 }
2219
2220 /* all other sections come after */
2221 for(i = 1; i < s1->nb_sections; i++) {
2222 s = s1->sections[i];
2223 if (phnum > 0 && (s->sh_flags & SHF_ALLOC))
2224 continue;
2225 sec_order[sh_order_index++] = i;
2226
2227 file_offset = (file_offset + s->sh_addralign - 1) &
2228 ~(s->sh_addralign - 1);
2229 s->sh_offset = file_offset;
2230 if (s->sh_type != SHT_NOBITS)
2231 file_offset += s->sh_size;
2232 }
2233
2234 return file_offset;
2235 }
2236
2237 static void fill_unloadable_phdr(ElfW(Phdr) *phdr, int phnum, Section *interp,
2238 Section *dynamic)
2239 {
2240 ElfW(Phdr) *ph;
2241
2242 /* if interpreter, then add corresponding program header */
2243 if (interp) {
2244 ph = &phdr[0];
2245
2246 if (HAVE_PHDR)
2247 {
2248 int len = phnum * sizeof(ElfW(Phdr));
2249
2250 ph->p_type = PT_PHDR;
2251 ph->p_offset = sizeof(ElfW(Ehdr));
2252 ph->p_vaddr = interp->sh_addr - len;
2253 ph->p_paddr = ph->p_vaddr;
2254 ph->p_filesz = ph->p_memsz = len;
2255 ph->p_flags = PF_R | PF_X;
2256 ph->p_align = 4; /* interp->sh_addralign; */
2257 ph++;
2258 }
2259
2260 ph->p_type = PT_INTERP;
2261 ph->p_offset = interp->sh_offset;
2262 ph->p_vaddr = interp->sh_addr;
2263 ph->p_paddr = ph->p_vaddr;
2264 ph->p_filesz = interp->sh_size;
2265 ph->p_memsz = interp->sh_size;
2266 ph->p_flags = PF_R;
2267 ph->p_align = interp->sh_addralign;
2268 }
2269
2270 /* if dynamic section, then add corresponding program header */
2271 if (dynamic) {
2272 ph = &phdr[phnum - 1];
2273
2274 ph->p_type = PT_DYNAMIC;
2275 ph->p_offset = dynamic->sh_offset;
2276 ph->p_vaddr = dynamic->sh_addr;
2277 ph->p_paddr = ph->p_vaddr;
2278 ph->p_filesz = dynamic->sh_size;
2279 ph->p_memsz = dynamic->sh_size;
2280 ph->p_flags = PF_R | PF_W;
2281 ph->p_align = dynamic->sh_addralign;
2282 }
2283 }
2284
2285 /* Fill the dynamic section with tags describing the address and size of
2286 sections */
2287 static void fill_dynamic(TCCState *s1, struct dyn_inf *dyninf)
2288 {
2289 Section *dynamic;
2290
2291 dynamic = dyninf->dynamic;
2292
2293 /* put dynamic section entries */
2294 dynamic->data_offset = dyninf->dyn_rel_off;
2295 put_dt(dynamic, DT_HASH, s1->dynsym->hash->sh_addr);
2296 put_dt(dynamic, DT_STRTAB, dyninf->dynstr->sh_addr);
2297 put_dt(dynamic, DT_SYMTAB, s1->dynsym->sh_addr);
2298 put_dt(dynamic, DT_STRSZ, dyninf->dynstr->data_offset);
2299 put_dt(dynamic, DT_SYMENT, sizeof(ElfW(Sym)));
2300 #if defined(TCC_TARGET_ARM64) || defined(TCC_TARGET_X86_64)
2301 put_dt(dynamic, DT_RELA, dyninf->rel_addr);
2302 put_dt(dynamic, DT_RELASZ, dyninf->rel_size);
2303 put_dt(dynamic, DT_RELAENT, sizeof(ElfW_Rel));
2304 #else
2305 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2306 put_dt(dynamic, DT_PLTGOT, s1->got->sh_addr);
2307 put_dt(dynamic, DT_PLTRELSZ, dyninf->rel_size);
2308 put_dt(dynamic, DT_JMPREL, dyninf->rel_addr);
2309 put_dt(dynamic, DT_PLTREL, DT_REL);
2310 put_dt(dynamic, DT_REL, dyninf->bss_addr);
2311 put_dt(dynamic, DT_RELSZ, dyninf->bss_size);
2312 #else
2313 put_dt(dynamic, DT_REL, dyninf->rel_addr);
2314 put_dt(dynamic, DT_RELSZ, dyninf->rel_size);
2315 put_dt(dynamic, DT_RELENT, sizeof(ElfW_Rel));
2316 #endif
2317 #endif
2318 if (s1->do_debug)
2319 put_dt(dynamic, DT_DEBUG, 0);
2320 put_dt(dynamic, DT_NULL, 0);
2321 }
2322
2323 /* Relocate remaining sections and symbols (that is those not related to
2324 dynamic linking) */
2325 static int final_sections_reloc(TCCState *s1)
2326 {
2327 int i;
2328 Section *s;
2329
2330 relocate_syms(s1, 0);
2331
2332 if (s1->nb_errors != 0)
2333 return -1;
2334
2335 /* relocate sections */
2336 /* XXX: ignore sections with allocated relocations ? */
2337 for(i = 1; i < s1->nb_sections; i++) {
2338 s = s1->sections[i];
2339 #ifdef TCC_TARGET_I386
2340 if (s->reloc && s != s1->got && (s->sh_flags & SHF_ALLOC)) //gr
2341 /* On X86 gdb 7.3 works in any case but gdb 6.6 will crash if SHF_ALLOC
2342 checking is removed */
2343 #else
2344 if (s->reloc && s != s1->got)
2345 /* On X86_64 gdb 7.3 will crash if SHF_ALLOC checking is present */
2346 #endif
2347 relocate_section(s1, s);
2348 }
2349
2350 /* relocate relocation entries if the relocation tables are
2351 allocated in the executable */
2352 for(i = 1; i < s1->nb_sections; i++) {
2353 s = s1->sections[i];
2354 if ((s->sh_flags & SHF_ALLOC) &&
2355 s->sh_type == SHT_RELX) {
2356 relocate_rel(s1, s);
2357 }
2358 }
2359 return 0;
2360 }
2361
2362 /* Create an ELF file on disk.
2363 This function handle ELF specific layout requirements */
2364 static void tcc_output_elf(TCCState *s1, FILE *f, int phnum, ElfW(Phdr) *phdr,
2365 int file_offset, int *sec_order)
2366 {
2367 int i, shnum, offset, size, file_type;
2368 Section *s;
2369 ElfW(Ehdr) ehdr;
2370 ElfW(Shdr) shdr, *sh;
2371
2372 file_type = s1->output_type;
2373 shnum = s1->nb_sections;
2374
2375 memset(&ehdr, 0, sizeof(ehdr));
2376
2377 if (phnum > 0) {
2378 ehdr.e_phentsize = sizeof(ElfW(Phdr));
2379 ehdr.e_phnum = phnum;
2380 ehdr.e_phoff = sizeof(ElfW(Ehdr));
2381 }
2382
2383 /* align to 4 */
2384 file_offset = (file_offset + 3) & -4;
2385
2386 /* fill header */
2387 ehdr.e_ident[0] = ELFMAG0;
2388 ehdr.e_ident[1] = ELFMAG1;
2389 ehdr.e_ident[2] = ELFMAG2;
2390 ehdr.e_ident[3] = ELFMAG3;
2391 ehdr.e_ident[4] = ELFCLASSW;
2392 ehdr.e_ident[5] = ELFDATA2LSB;
2393 ehdr.e_ident[6] = EV_CURRENT;
2394 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2395 ehdr.e_ident[EI_OSABI] = ELFOSABI_FREEBSD;
2396 #endif
2397 #ifdef TCC_TARGET_ARM
2398 #ifdef TCC_ARM_EABI
2399 ehdr.e_ident[EI_OSABI] = 0;
2400 ehdr.e_flags = EF_ARM_EABI_VER4;
2401 if (file_type == TCC_OUTPUT_EXE || file_type == TCC_OUTPUT_DLL)
2402 ehdr.e_flags |= EF_ARM_HASENTRY;
2403 if (s1->float_abi == ARM_HARD_FLOAT)
2404 ehdr.e_flags |= EF_ARM_VFP_FLOAT;
2405 else
2406 ehdr.e_flags |= EF_ARM_SOFT_FLOAT;
2407 #else
2408 ehdr.e_ident[EI_OSABI] = ELFOSABI_ARM;
2409 #endif
2410 #endif
2411 switch(file_type) {
2412 default:
2413 case TCC_OUTPUT_EXE:
2414 ehdr.e_type = ET_EXEC;
2415 ehdr.e_entry = get_elf_sym_addr(s1, "_start", 1);
2416 break;
2417 case TCC_OUTPUT_DLL:
2418 ehdr.e_type = ET_DYN;
2419 ehdr.e_entry = text_section->sh_addr; /* XXX: is it correct ? */
2420 break;
2421 case TCC_OUTPUT_OBJ:
2422 ehdr.e_type = ET_REL;
2423 break;
2424 }
2425 ehdr.e_machine = EM_TCC_TARGET;
2426 ehdr.e_version = EV_CURRENT;
2427 ehdr.e_shoff = file_offset;
2428 ehdr.e_ehsize = sizeof(ElfW(Ehdr));
2429 ehdr.e_shentsize = sizeof(ElfW(Shdr));
2430 ehdr.e_shnum = shnum;
2431 ehdr.e_shstrndx = shnum - 1;
2432
2433 fwrite(&ehdr, 1, sizeof(ElfW(Ehdr)), f);
2434 fwrite(phdr, 1, phnum * sizeof(ElfW(Phdr)), f);
2435 offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr));
2436
2437 sort_syms(s1, symtab_section);
2438 for(i = 1; i < s1->nb_sections; i++) {
2439 s = s1->sections[sec_order[i]];
2440 if (s->sh_type != SHT_NOBITS) {
2441 if (s->sh_type == SHT_DYNSYM)
2442 patch_dynsym_undef(s1, s);
2443 while (offset < s->sh_offset) {
2444 fputc(0, f);
2445 offset++;
2446 }
2447 size = s->sh_size;
2448 if (size)
2449 fwrite(s->data, 1, size, f);
2450 offset += size;
2451 }
2452 }
2453
2454 /* output section headers */
2455 while (offset < ehdr.e_shoff) {
2456 fputc(0, f);
2457 offset++;
2458 }
2459
2460 for(i = 0; i < s1->nb_sections; i++) {
2461 sh = &shdr;
2462 memset(sh, 0, sizeof(ElfW(Shdr)));
2463 s = s1->sections[i];
2464 if (s) {
2465 sh->sh_name = s->sh_name;
2466 sh->sh_type = s->sh_type;
2467 sh->sh_flags = s->sh_flags;
2468 sh->sh_entsize = s->sh_entsize;
2469 sh->sh_info = s->sh_info;
2470 if (s->link)
2471 sh->sh_link = s->link->sh_num;
2472 sh->sh_addralign = s->sh_addralign;
2473 sh->sh_addr = s->sh_addr;
2474 sh->sh_offset = s->sh_offset;
2475 sh->sh_size = s->sh_size;
2476 }
2477 fwrite(sh, 1, sizeof(ElfW(Shdr)), f);
2478 }
2479 }
2480
2481 /* Write an elf, coff or "binary" file */
2482 static int tcc_write_elf_file(TCCState *s1, const char *filename, int phnum,
2483 ElfW(Phdr) *phdr, int file_offset, int *sec_order)
2484 {
2485 int fd, mode, file_type;
2486 FILE *f;
2487
2488 file_type = s1->output_type;
2489 if (file_type == TCC_OUTPUT_OBJ)
2490 mode = 0666;
2491 else
2492 mode = 0777;
2493 unlink(filename);
2494 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, mode);
2495 if (fd < 0) {
2496 tcc_error_noabort("could not write '%s'", filename);
2497 return -1;
2498 }
2499 f = fdopen(fd, "wb");
2500 if (s1->verbose)
2501 printf("<- %s\n", filename);
2502
2503 #ifdef TCC_TARGET_COFF
2504 if (s1->output_format == TCC_OUTPUT_FORMAT_COFF)
2505 tcc_output_coff(s1, f);
2506 else
2507 #endif
2508 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF)
2509 tcc_output_elf(s1, f, phnum, phdr, file_offset, sec_order);
2510 else
2511 tcc_output_binary(s1, f, sec_order);
2512 fclose(f);
2513
2514 return 0;
2515 }
2516
2517 /* Output an elf, coff or binary file */
2518 /* XXX: suppress unneeded sections */
2519 static int elf_output_file(TCCState *s1, const char *filename)
2520 {
2521 int i, ret, phnum, shnum, file_type, file_offset, *sec_order;
2522 struct dyn_inf dyninf;
2523 ElfW(Phdr) *phdr;
2524 ElfW(Sym) *sym;
2525 Section *strsec, *interp, *dynamic, *dynstr;
2526
2527 file_type = s1->output_type;
2528 s1->nb_errors = 0;
2529
2530 /* if linking, also link in runtime libraries (libc, libgcc, etc.) */
2531 if (file_type != TCC_OUTPUT_OBJ) {
2532 tcc_add_runtime(s1);
2533 }
2534
2535 phdr = NULL;
2536 sec_order = NULL;
2537 interp = dynamic = dynstr = NULL; /* avoid warning */
2538 dyninf.dyn_rel_off = 0; /* avoid warning */
2539
2540 if (file_type != TCC_OUTPUT_OBJ) {
2541 relocate_common_syms();
2542
2543 tcc_add_linker_symbols(s1);
2544
2545 if (!s1->static_link) {
2546 if (file_type == TCC_OUTPUT_EXE) {
2547 char *ptr;
2548 /* allow override the dynamic loader */
2549 const char *elfint = getenv("LD_SO");
2550 if (elfint == NULL)
2551 elfint = DEFAULT_ELFINTERP(s1);
2552 /* add interpreter section only if executable */
2553 interp = new_section(s1, ".interp", SHT_PROGBITS, SHF_ALLOC);
2554 interp->sh_addralign = 1;
2555 ptr = section_ptr_add(interp, 1 + strlen(elfint));
2556 strcpy(ptr, elfint);
2557 }
2558
2559 /* add dynamic symbol table */
2560 s1->dynsym = new_symtab(s1, ".dynsym", SHT_DYNSYM, SHF_ALLOC,
2561 ".dynstr",
2562 ".hash", SHF_ALLOC);
2563 dynstr = s1->dynsym->link;
2564
2565 /* add dynamic section */
2566 dynamic = new_section(s1, ".dynamic", SHT_DYNAMIC,
2567 SHF_ALLOC | SHF_WRITE);
2568 dynamic->link = dynstr;
2569 dynamic->sh_entsize = sizeof(ElfW(Dyn));
2570
2571 build_got(s1);
2572
2573 if (file_type == TCC_OUTPUT_EXE) {
2574 bind_exe_dynsyms(s1);
2575
2576 if (s1->nb_errors) {
2577 ret = -1;
2578 goto the_end;
2579 }
2580
2581 bind_libs_dynsyms(s1);
2582 } else /* shared library case: simply export all global symbols */
2583 export_global_syms(s1);
2584
2585 build_got_entries(s1);
2586
2587 /* add a list of needed dlls */
2588 for(i = 0; i < s1->nb_loaded_dlls; i++) {
2589 DLLReference *dllref = s1->loaded_dlls[i];
2590 if (dllref->level == 0)
2591 put_dt(dynamic, DT_NEEDED, put_elf_str(dynstr, dllref->name));
2592 }
2593
2594 if (s1->rpath)
2595 put_dt(dynamic, DT_RPATH, put_elf_str(dynstr, s1->rpath));
2596
2597 /* XXX: currently, since we do not handle PIC code, we
2598 must relocate the readonly segments */
2599 if (file_type == TCC_OUTPUT_DLL) {
2600 if (s1->soname)
2601 put_dt(dynamic, DT_SONAME, put_elf_str(dynstr, s1->soname));
2602 put_dt(dynamic, DT_TEXTREL, 0);
2603 }
2604
2605 if (s1->symbolic)
2606 put_dt(dynamic, DT_SYMBOLIC, 0);
2607
2608 /* add necessary space for other entries */
2609 dyninf.dyn_rel_off = dynamic->data_offset;
2610 dynamic->data_offset += sizeof(ElfW(Dyn)) * EXTRA_RELITEMS;
2611 } else {
2612 /* still need to build got entries in case of static link */
2613 build_got_entries(s1);
2614 }
2615 }
2616
2617 /* we add a section for symbols */
2618 strsec = new_section(s1, ".shstrtab", SHT_STRTAB, 0);
2619 put_elf_str(strsec, "");
2620
2621 /* compute number of sections */
2622 shnum = s1->nb_sections;
2623
2624 /* this array is used to reorder sections in the output file */
2625 sec_order = tcc_malloc(sizeof(int) * shnum);
2626 sec_order[0] = 0;
2627
2628 /* compute number of program headers */
2629 switch(file_type) {
2630 default:
2631 case TCC_OUTPUT_OBJ:
2632 phnum = 0;
2633 break;
2634 case TCC_OUTPUT_EXE:
2635 if (!s1->static_link)
2636 phnum = 4 + HAVE_PHDR;
2637 else
2638 phnum = 2;
2639 break;
2640 case TCC_OUTPUT_DLL:
2641 phnum = 3;
2642 break;
2643 }
2644
2645 /* Allocate strings for section names */
2646 alloc_sec_names(s1, file_type, strsec);
2647
2648 /* allocate program segment headers */
2649 phdr = tcc_mallocz(phnum * sizeof(ElfW(Phdr)));
2650
2651 /* compute section to program header mapping */
2652 file_offset = layout_sections(s1, phdr, phnum, interp, strsec, &dyninf,
2653 sec_order);
2654
2655 /* Fill remaining program header and finalize relocation related to dynamic
2656 linking. */
2657 if (phnum > 0) {
2658 fill_unloadable_phdr(phdr, phnum, interp, dynamic);
2659 if (dynamic) {
2660 dyninf.dynamic = dynamic;
2661 dyninf.dynstr = dynstr;
2662
2663 fill_dynamic(s1, &dyninf);
2664
2665 /* put in GOT the dynamic section address and relocate PLT */
2666 write32le(s1->got->data, dynamic->sh_addr);
2667 if (file_type == TCC_OUTPUT_EXE
2668 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
2669 || file_type == TCC_OUTPUT_DLL
2670 #endif
2671 )
2672 relocate_plt(s1);
2673
2674 /* relocate symbols in .dynsym now that final addresses are known */
2675 for_each_elem(s1->dynsym, 1, sym, ElfW(Sym)) {
2676 if (sym->st_shndx == SHN_UNDEF) {
2677 /* relocate to PLT if symbol corresponds to a PLT entry,
2678 but not if it's a weak symbol */
2679 if (ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
2680 sym->st_value = 0;
2681 else if (sym->st_value)
2682 sym->st_value += s1->plt->sh_addr;
2683 } else if (sym->st_shndx < SHN_LORESERVE) {
2684 /* do symbol relocation */
2685 sym->st_value += s1->sections[sym->st_shndx]->sh_addr;
2686 }
2687 }
2688 }
2689 }
2690
2691 /* if building executable or DLL, then relocate each section
2692 except the GOT which is already relocated */
2693 if (file_type != TCC_OUTPUT_OBJ) {
2694 ret = final_sections_reloc(s1);
2695 if (ret)
2696 goto the_end;
2697 }
2698
2699 /* Perform relocation to GOT or PLT entries */
2700 if (file_type == TCC_OUTPUT_EXE && s1->static_link)
2701 fill_got(s1);
2702
2703 /* Create the ELF file with name 'filename' */
2704 ret = tcc_write_elf_file(s1, filename, phnum, phdr, file_offset, sec_order);
2705 if (s1->do_strip) {
2706 int rc;
2707 const char *strip_cmd = "sstrip "; // super strip utility from ELFkickers
2708 const char *null_dev = " 2> /dev/null";
2709 char buf[1050];
2710 snprintf(buf, sizeof(buf), "%s%s%s", strip_cmd, filename, null_dev);
2711 rc = system(buf);
2712 if (rc)
2713 system(buf+1); // call a strip utility from binutils
2714 }
2715 the_end:
2716 tcc_free(s1->symtab_to_dynsym);
2717 tcc_free(sec_order);
2718 tcc_free(phdr);
2719 tcc_free(s1->sym_attrs);
2720 s1->sym_attrs = NULL;
2721 return ret;
2722 }
2723
2724 LIBTCCAPI int tcc_output_file(TCCState *s, const char *filename)
2725 {
2726 int ret;
2727 #ifdef TCC_TARGET_PE
2728 if (s->output_type != TCC_OUTPUT_OBJ) {
2729 ret = pe_output_file(s, filename);
2730 } else
2731 #endif
2732 ret = elf_output_file(s, filename);
2733 return ret;
2734 }
2735
2736 static void *load_data(int fd, unsigned long file_offset, unsigned long size)
2737 {
2738 void *data;
2739
2740 data = tcc_malloc(size);
2741 lseek(fd, file_offset, SEEK_SET);
2742 read(fd, data, size);
2743 return data;
2744 }
2745
2746 typedef struct SectionMergeInfo {
2747 Section *s; /* corresponding existing section */
2748 unsigned long offset; /* offset of the new section in the existing section */
2749 uint8_t new_section; /* true if section 's' was added */
2750 uint8_t link_once; /* true if link once section */
2751 } SectionMergeInfo;
2752
2753 /* load an object file and merge it with current files */
2754 /* XXX: handle correctly stab (debug) info */
2755 ST_FUNC int tcc_load_object_file(TCCState *s1,
2756 int fd, unsigned long file_offset)
2757 {
2758 ElfW(Ehdr) ehdr;
2759 ElfW(Shdr) *shdr, *sh;
2760 int size, i, j, offset, offseti, nb_syms, sym_index, ret;
2761 unsigned char *strsec, *strtab;
2762 int *old_to_new_syms;
2763 char *sh_name, *name;
2764 SectionMergeInfo *sm_table, *sm;
2765 ElfW(Sym) *sym, *symtab;
2766 ElfW_Rel *rel;
2767 Section *s;
2768
2769 int stab_index;
2770 int stabstr_index;
2771
2772 stab_index = stabstr_index = 0;
2773
2774 if (read(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr))
2775 goto fail1;
2776 if (ehdr.e_ident[0] != ELFMAG0 ||
2777 ehdr.e_ident[1] != ELFMAG1 ||
2778 ehdr.e_ident[2] != ELFMAG2 ||
2779 ehdr.e_ident[3] != ELFMAG3)
2780 goto fail1;
2781 /* test if object file */
2782 if (ehdr.e_type != ET_REL)
2783 goto fail1;
2784 /* test CPU specific stuff */
2785 if (ehdr.e_ident[5] != ELFDATA2LSB ||
2786 ehdr.e_machine != EM_TCC_TARGET) {
2787 fail1:
2788 tcc_error_noabort("invalid object file");
2789 return -1;
2790 }
2791 /* read sections */
2792 shdr = load_data(fd, file_offset + ehdr.e_shoff,
2793 sizeof(ElfW(Shdr)) * ehdr.e_shnum);
2794 sm_table = tcc_mallocz(sizeof(SectionMergeInfo) * ehdr.e_shnum);
2795
2796 /* load section names */
2797 sh = &shdr[ehdr.e_shstrndx];
2798 strsec = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2799
2800 /* load symtab and strtab */
2801 old_to_new_syms = NULL;
2802 symtab = NULL;
2803 strtab = NULL;
2804 nb_syms = 0;
2805 for(i = 1; i < ehdr.e_shnum; i++) {
2806 sh = &shdr[i];
2807 if (sh->sh_type == SHT_SYMTAB) {
2808 if (symtab) {
2809 tcc_error_noabort("object must contain only one symtab");
2810 fail:
2811 ret = -1;
2812 goto the_end;
2813 }
2814 nb_syms = sh->sh_size / sizeof(ElfW(Sym));
2815 symtab = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2816 sm_table[i].s = symtab_section;
2817
2818 /* now load strtab */
2819 sh = &shdr[sh->sh_link];
2820 strtab = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2821 }
2822 }
2823
2824 /* now examine each section and try to merge its content with the
2825 ones in memory */
2826 for(i = 1; i < ehdr.e_shnum; i++) {
2827 /* no need to examine section name strtab */
2828 if (i == ehdr.e_shstrndx)
2829 continue;
2830 sh = &shdr[i];
2831 sh_name = (char *) strsec + sh->sh_name;
2832 /* ignore sections types we do not handle */
2833 if (sh->sh_type != SHT_PROGBITS &&
2834 sh->sh_type != SHT_RELX &&
2835 #ifdef TCC_ARM_EABI
2836 sh->sh_type != SHT_ARM_EXIDX &&
2837 #endif
2838 sh->sh_type != SHT_NOBITS &&
2839 sh->sh_type != SHT_PREINIT_ARRAY &&
2840 sh->sh_type != SHT_INIT_ARRAY &&
2841 sh->sh_type != SHT_FINI_ARRAY &&
2842 strcmp(sh_name, ".stabstr")
2843 )
2844 continue;
2845 if (sh->sh_addralign < 1)
2846 sh->sh_addralign = 1;
2847 /* find corresponding section, if any */
2848 for(j = 1; j < s1->nb_sections;j++) {
2849 s = s1->sections[j];
2850 if (!strcmp(s->name, sh_name)) {
2851 if (!strncmp(sh_name, ".gnu.linkonce",
2852 sizeof(".gnu.linkonce") - 1)) {
2853 /* if a 'linkonce' section is already present, we
2854 do not add it again. It is a little tricky as
2855 symbols can still be defined in
2856 it. */
2857 sm_table[i].link_once = 1;
2858 goto next;
2859 } else {
2860 goto found;
2861 }
2862 }
2863 }
2864 /* not found: create new section */
2865 s = new_section(s1, sh_name, sh->sh_type, sh->sh_flags);
2866 /* take as much info as possible from the section. sh_link and
2867 sh_info will be updated later */
2868 s->sh_addralign = sh->sh_addralign;
2869 s->sh_entsize = sh->sh_entsize;
2870 sm_table[i].new_section = 1;
2871 found:
2872 if (sh->sh_type != s->sh_type) {
2873 tcc_error_noabort("invalid section type");
2874 goto fail;
2875 }
2876
2877 /* align start of section */
2878 offset = s->data_offset;
2879
2880 if (0 == strcmp(sh_name, ".stab")) {
2881 stab_index = i;
2882 goto no_align;
2883 }
2884 if (0 == strcmp(sh_name, ".stabstr")) {
2885 stabstr_index = i;
2886 goto no_align;
2887 }
2888
2889 size = sh->sh_addralign - 1;
2890 offset = (offset + size) & ~size;
2891 if (sh->sh_addralign > s->sh_addralign)
2892 s->sh_addralign = sh->sh_addralign;
2893 s->data_offset = offset;
2894 no_align:
2895 sm_table[i].offset = offset;
2896 sm_table[i].s = s;
2897 /* concatenate sections */
2898 size = sh->sh_size;
2899 if (sh->sh_type != SHT_NOBITS) {
2900 unsigned char *ptr;
2901 lseek(fd, file_offset + sh->sh_offset, SEEK_SET);
2902 ptr = section_ptr_add(s, size);
2903 read(fd, ptr, size);
2904 } else {
2905 s->data_offset += size;
2906 }
2907 next: ;
2908 }
2909
2910 /* gr relocate stab strings */
2911 if (stab_index && stabstr_index) {
2912 Stab_Sym *a, *b;
2913 unsigned o;
2914 s = sm_table[stab_index].s;
2915 a = (Stab_Sym *)(s->data + sm_table[stab_index].offset);
2916 b = (Stab_Sym *)(s->data + s->data_offset);
2917 o = sm_table[stabstr_index].offset;
2918 while (a < b)
2919 a->n_strx += o, a++;
2920 }
2921
2922 /* second short pass to update sh_link and sh_info fields of new
2923 sections */
2924 for(i = 1; i < ehdr.e_shnum; i++) {
2925 s = sm_table[i].s;
2926 if (!s || !sm_table[i].new_section)
2927 continue;
2928 sh = &shdr[i];
2929 if (sh->sh_link > 0)
2930 s->link = sm_table[sh->sh_link].s;
2931 if (sh->sh_type == SHT_RELX) {
2932 s->sh_info = sm_table[sh->sh_info].s->sh_num;
2933 /* update backward link */
2934 s1->sections[s->sh_info]->reloc = s;
2935 }
2936 }
2937 sm = sm_table;
2938
2939 /* resolve symbols */
2940 old_to_new_syms = tcc_mallocz(nb_syms * sizeof(int));
2941
2942 sym = symtab + 1;
2943 for(i = 1; i < nb_syms; i++, sym++) {
2944 if (sym->st_shndx != SHN_UNDEF &&
2945 sym->st_shndx < SHN_LORESERVE) {
2946 sm = &sm_table[sym->st_shndx];
2947 if (sm->link_once) {
2948 /* if a symbol is in a link once section, we use the
2949 already defined symbol. It is very important to get
2950 correct relocations */
2951 if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
2952 name = (char *) strtab + sym->st_name;
2953 sym_index = find_elf_sym(symtab_section, name);
2954 if (sym_index)
2955 old_to_new_syms[i] = sym_index;
2956 }
2957 continue;
2958 }
2959 /* if no corresponding section added, no need to add symbol */
2960 if (!sm->s)
2961 continue;
2962 /* convert section number */
2963 sym->st_shndx = sm->s->sh_num;
2964 /* offset value */
2965 sym->st_value += sm->offset;
2966 }
2967 /* add symbol */
2968 name = (char *) strtab + sym->st_name;
2969 sym_index = add_elf_sym(symtab_section, sym->st_value, sym->st_size,
2970 sym->st_info, sym->st_other,
2971 sym->st_shndx, name);
2972 old_to_new_syms[i] = sym_index;
2973 }
2974
2975 /* third pass to patch relocation entries */
2976 for(i = 1; i < ehdr.e_shnum; i++) {
2977 s = sm_table[i].s;
2978 if (!s)
2979 continue;
2980 sh = &shdr[i];
2981 offset = sm_table[i].offset;
2982 switch(s->sh_type) {
2983 case SHT_RELX:
2984 /* take relocation offset information */
2985 offseti = sm_table[sh->sh_info].offset;
2986 for_each_elem(s, (offset / sizeof(*rel)), rel, ElfW_Rel) {
2987 int type;
2988 unsigned sym_index;
2989 /* convert symbol index */
2990 type = ELFW(R_TYPE)(rel->r_info);
2991 sym_index = ELFW(R_SYM)(rel->r_info);
2992 /* NOTE: only one symtab assumed */
2993 if (sym_index >= nb_syms)
2994 goto invalid_reloc;
2995 sym_index = old_to_new_syms[sym_index];
2996 /* ignore link_once in rel section. */
2997 if (!sym_index && !sm->link_once
2998 #ifdef TCC_TARGET_ARM
2999 && type != R_ARM_V4BX
3000 #endif
3001 ) {
3002 invalid_reloc:
3003 tcc_error_noabort("Invalid relocation entry [%2d] '%s' @ %.8x",
3004 i, strsec + sh->sh_name, rel->r_offset);
3005 goto fail;
3006 }
3007 rel->r_info = ELFW(R_INFO)(sym_index, type);
3008 /* offset the relocation offset */
3009 rel->r_offset += offseti;
3010 #ifdef TCC_TARGET_ARM
3011 /* Jumps and branches from a Thumb code to a PLT entry need
3012 special handling since PLT entries are ARM code.
3013 Unconditional bl instructions referencing PLT entries are
3014 handled by converting these instructions into blx
3015 instructions. Other case of instructions referencing a PLT
3016 entry require to add a Thumb stub before the PLT entry to
3017 switch to ARM mode. We set bit plt_thumb_stub of the
3018 attribute of a symbol to indicate such a case. */
3019 if (type == R_ARM_THM_JUMP24)
3020 alloc_sym_attr(s1, sym_index)->plt_thumb_stub = 1;
3021 #endif
3022 }
3023 break;
3024 default:
3025 break;
3026 }
3027 }
3028
3029 ret = 0;
3030 the_end:
3031 tcc_free(symtab);
3032 tcc_free(strtab);
3033 tcc_free(old_to_new_syms);
3034 tcc_free(sm_table);
3035 tcc_free(strsec);
3036 tcc_free(shdr);
3037 return ret;
3038 }
3039
3040 typedef struct ArchiveHeader {
3041 char ar_name[16]; /* name of this member */
3042 char ar_date[12]; /* file mtime */
3043 char ar_uid[6]; /* owner uid; printed as decimal */
3044 char ar_gid[6]; /* owner gid; printed as decimal */
3045 char ar_mode[8]; /* file mode, printed as octal */
3046 char ar_size[10]; /* file size, printed as decimal */
3047 char ar_fmag[2]; /* should contain ARFMAG */
3048 } ArchiveHeader;
3049
3050 static int get_be32(const uint8_t *b)
3051 {
3052 return b[3] | (b[2] << 8) | (b[1] << 16) | (b[0] << 24);
3053 }
3054
3055 /* load only the objects which resolve undefined symbols */
3056 static int tcc_load_alacarte(TCCState *s1, int fd, int size)
3057 {
3058 int i, bound, nsyms, sym_index, off, ret;
3059 uint8_t *data;
3060 const char *ar_names, *p;
3061 const uint8_t *ar_index;
3062 ElfW(Sym) *sym;
3063
3064 data = tcc_malloc(size);
3065 if (read(fd, data, size) != size)
3066 goto fail;
3067 nsyms = get_be32(data);
3068 ar_index = data + 4;
3069 ar_names = (char *) ar_index + nsyms * 4;
3070
3071 do {
3072 bound = 0;
3073 for(p = ar_names, i = 0; i < nsyms; i++, p += strlen(p)+1) {
3074 sym_index = find_elf_sym(symtab_section, p);
3075 if(sym_index) {
3076 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
3077 if(sym->st_shndx == SHN_UNDEF) {
3078 off = get_be32(ar_index + i * 4) + sizeof(ArchiveHeader);
3079 ++bound;
3080 lseek(fd, off, SEEK_SET);
3081 if(tcc_load_object_file(s1, fd, off) < 0) {
3082 fail:
3083 ret = -1;
3084 goto the_end;
3085 }
3086 }
3087 }
3088 }
3089 } while(bound);
3090 ret = 0;
3091 the_end:
3092 tcc_free(data);
3093 return ret;
3094 }
3095
3096 /* load a '.a' file */
3097 ST_FUNC int tcc_load_archive(TCCState *s1, int fd)
3098 {
3099 ArchiveHeader hdr;
3100 char ar_size[11];
3101 char ar_name[17];
3102 char magic[8];
3103 int size, len, i;
3104 unsigned long file_offset;
3105
3106 /* skip magic which was already checked */
3107 read(fd, magic, sizeof(magic));
3108
3109 for(;;) {
3110 len = read(fd, &hdr, sizeof(hdr));
3111 if (len == 0)
3112 break;
3113 if (len != sizeof(hdr)) {
3114 tcc_error_noabort("invalid archive");
3115 return -1;
3116 }
3117 memcpy(ar_size, hdr.ar_size, sizeof(hdr.ar_size));
3118 ar_size[sizeof(hdr.ar_size)] = '\0';
3119 size = strtol(ar_size, NULL, 0);
3120 memcpy(ar_name, hdr.ar_name, sizeof(hdr.ar_name));
3121 for(i = sizeof(hdr.ar_name) - 1; i >= 0; i--) {
3122 if (ar_name[i] != ' ')
3123 break;
3124 }
3125 ar_name[i + 1] = '\0';
3126 file_offset = lseek(fd, 0, SEEK_CUR);
3127 /* align to even */
3128 size = (size + 1) & ~1;
3129 if (!strcmp(ar_name, "/")) {
3130 /* coff symbol table : we handle it */
3131 if(s1->alacarte_link)
3132 return tcc_load_alacarte(s1, fd, size);
3133 } else if (!strcmp(ar_name, "//") ||
3134 !strcmp(ar_name, "__.SYMDEF") ||
3135 !strcmp(ar_name, "__.SYMDEF/") ||
3136 !strcmp(ar_name, "ARFILENAMES/")) {
3137 /* skip symbol table or archive names */
3138 } else {
3139 if (tcc_load_object_file(s1, fd, file_offset) < 0)
3140 return -1;
3141 }
3142 lseek(fd, file_offset + size, SEEK_SET);
3143 }
3144 return 0;
3145 }
3146
3147 #ifndef TCC_TARGET_PE
3148 /* load a DLL and all referenced DLLs. 'level = 0' means that the DLL
3149 is referenced by the user (so it should be added as DT_NEEDED in
3150 the generated ELF file) */
3151 ST_FUNC int tcc_load_dll(TCCState *s1, int fd, const char *filename, int level)
3152 {
3153 ElfW(Ehdr) ehdr;
3154 ElfW(Shdr) *shdr, *sh, *sh1;
3155 int i, j, nb_syms, nb_dts, sym_bind, ret;
3156 ElfW(Sym) *sym, *dynsym;
3157 ElfW(Dyn) *dt, *dynamic;
3158 unsigned char *dynstr;
3159 const char *name, *soname;
3160 DLLReference *dllref;
3161
3162 read(fd, &ehdr, sizeof(ehdr));
3163
3164 /* test CPU specific stuff */
3165 if (ehdr.e_ident[5] != ELFDATA2LSB ||
3166 ehdr.e_machine != EM_TCC_TARGET) {
3167 tcc_error_noabort("bad architecture");
3168 return -1;
3169 }
3170
3171 /* read sections */
3172 shdr = load_data(fd, ehdr.e_shoff, sizeof(ElfW(Shdr)) * ehdr.e_shnum);
3173
3174 /* load dynamic section and dynamic symbols */
3175 nb_syms = 0;
3176 nb_dts = 0;
3177 dynamic = NULL;
3178 dynsym = NULL; /* avoid warning */
3179 dynstr = NULL; /* avoid warning */
3180 for(i = 0, sh = shdr; i < ehdr.e_shnum; i++, sh++) {
3181 switch(sh->sh_type) {
3182 case SHT_DYNAMIC:
3183 nb_dts = sh->sh_size / sizeof(ElfW(Dyn));
3184 dynamic = load_data(fd, sh->sh_offset, sh->sh_size);
3185 break;
3186 case SHT_DYNSYM:
3187 nb_syms = sh->sh_size / sizeof(ElfW(Sym));
3188 dynsym = load_data(fd, sh->sh_offset, sh->sh_size);
3189 sh1 = &shdr[sh->sh_link];
3190 dynstr = load_data(fd, sh1->sh_offset, sh1->sh_size);
3191 break;
3192 default:
3193 break;
3194 }
3195 }
3196
3197 /* compute the real library name */
3198 soname = tcc_basename(filename);
3199
3200 for(i = 0, dt = dynamic; i < nb_dts; i++, dt++) {
3201 if (dt->d_tag == DT_SONAME) {
3202 soname = (char *) dynstr + dt->d_un.d_val;
3203 }
3204 }
3205
3206 /* if the dll is already loaded, do not load it */
3207 for(i = 0; i < s1->nb_loaded_dlls; i++) {
3208 dllref = s1->loaded_dlls[i];
3209 if (!strcmp(soname, dllref->name)) {
3210 /* but update level if needed */
3211 if (level < dllref->level)
3212 dllref->level = level;
3213 ret = 0;
3214 goto the_end;
3215 }
3216 }
3217
3218 /* add the dll and its level */
3219 dllref = tcc_mallocz(sizeof(DLLReference) + strlen(soname));
3220 dllref->level = level;
3221 strcpy(dllref->name, soname);
3222 dynarray_add((void ***)&s1->loaded_dlls, &s1->nb_loaded_dlls, dllref);
3223
3224 /* add dynamic symbols in dynsym_section */
3225 for(i = 1, sym = dynsym + 1; i < nb_syms; i++, sym++) {
3226 sym_bind = ELFW(ST_BIND)(sym->st_info);
3227 if (sym_bind == STB_LOCAL)
3228 continue;
3229 name = (char *) dynstr + sym->st_name;
3230 add_elf_sym(s1->dynsymtab_section, sym->st_value, sym->st_size,
3231 sym->st_info, sym->st_other, sym->st_shndx, name);
3232 }
3233
3234 /* load all referenced DLLs */
3235 for(i = 0, dt = dynamic; i < nb_dts; i++, dt++) {
3236 switch(dt->d_tag) {
3237 case DT_NEEDED:
3238 name = (char *) dynstr + dt->d_un.d_val;
3239 for(j = 0; j < s1->nb_loaded_dlls; j++) {
3240 dllref = s1->loaded_dlls[j];
3241 if (!strcmp(name, dllref->name))
3242 goto already_loaded;
3243 }
3244 if (tcc_add_dll(s1, name, AFF_REFERENCED_DLL) < 0) {
3245 tcc_error_noabort("referenced dll '%s' not found", name);
3246 ret = -1;
3247 goto the_end;
3248 }
3249 already_loaded:
3250 break;
3251 }
3252 }
3253 ret = 0;
3254 the_end:
3255 tcc_free(dynstr);
3256 tcc_free(dynsym);
3257 tcc_free(dynamic);
3258 tcc_free(shdr);
3259 return ret;
3260 }
3261
3262 #define LD_TOK_NAME 256
3263 #define LD_TOK_EOF (-1)
3264
3265 /* return next ld script token */
3266 static int ld_next(TCCState *s1, char *name, int name_size)
3267 {
3268 int c;
3269 char *q;
3270
3271 redo:
3272 switch(ch) {
3273 case ' ':
3274 case '\t':
3275 case '\f':
3276 case '\v':
3277 case '\r':
3278 case '\n':
3279 inp();
3280 goto redo;
3281 case '/':
3282 minp();
3283 if (ch == '*') {
3284 file->buf_ptr = parse_comment(file->buf_ptr);
3285 ch = file->buf_ptr[0];
3286 goto redo;
3287 } else {
3288 q = name;
3289 *q++ = '/';
3290 goto parse_name;
3291 }
3292 break;
3293 case '\\':
3294 ch = handle_eob();
3295 if (ch != '\\')
3296 goto redo;
3297 /* fall through */
3298 /* case 'a' ... 'z': */
3299 case 'a':
3300 case 'b':
3301 case 'c':
3302 case 'd':
3303 case 'e':
3304 case 'f':
3305 case 'g':
3306 case 'h':
3307 case 'i':
3308 case 'j':
3309 case 'k':
3310 case 'l':
3311 case 'm':
3312 case 'n':
3313 case 'o':
3314 case 'p':
3315 case 'q':
3316 case 'r':
3317 case 's':
3318 case 't':
3319 case 'u':
3320 case 'v':
3321 case 'w':
3322 case 'x':
3323 case 'y':
3324 case 'z':
3325 /* case 'A' ... 'z': */
3326 case 'A':
3327 case 'B':
3328 case 'C':
3329 case 'D':
3330 case 'E':
3331 case 'F':
3332 case 'G':
3333 case 'H':
3334 case 'I':
3335 case 'J':
3336 case 'K':
3337 case 'L':
3338 case 'M':
3339 case 'N':
3340 case 'O':
3341 case 'P':
3342 case 'Q':
3343 case 'R':
3344 case 'S':
3345 case 'T':
3346 case 'U':
3347 case 'V':
3348 case 'W':
3349 case 'X':
3350 case 'Y':
3351 case 'Z':
3352 case '_':
3353 case '.':
3354 case '$':
3355 case '~':
3356 q = name;
3357 parse_name:
3358 for(;;) {
3359 if (!((ch >= 'a' && ch <= 'z') ||
3360 (ch >= 'A' && ch <= 'Z') ||
3361 (ch >= '0' && ch <= '9') ||
3362 strchr("/.-_+=$:\\,~", ch)))
3363 break;
3364 if ((q - name) < name_size - 1) {
3365 *q++ = ch;
3366 }
3367 minp();
3368 }
3369 *q = '\0';
3370 c = LD_TOK_NAME;
3371 break;
3372 case CH_EOF:
3373 c = LD_TOK_EOF;
3374 break;
3375 default:
3376 c = ch;
3377 inp();
3378 break;
3379 }
3380 return c;
3381 }
3382
3383 static int ld_add_file(TCCState *s1, const char filename[])
3384 {
3385 int ret;
3386
3387 ret = tcc_add_file_internal(s1, filename, AFF_TYPE_BIN);
3388 if (ret)
3389 ret = tcc_add_dll(s1, filename, 0);
3390 return ret;
3391 }
3392
3393 static inline int new_undef_syms(void)
3394 {
3395 int ret = 0;
3396 ret = new_undef_sym;
3397 new_undef_sym = 0;
3398 return ret;
3399 }
3400
3401 static int ld_add_file_list(TCCState *s1, const char *cmd, int as_needed)
3402 {
3403 char filename[1024], libname[1024];
3404 int t, group, nblibs = 0, ret = 0;
3405 char **libs = NULL;
3406
3407 group = !strcmp(cmd, "GROUP");
3408 if (!as_needed)
3409 new_undef_syms();
3410 t = ld_next(s1, filename, sizeof(filename));
3411 if (t != '(')
3412 expect("(");
3413 t = ld_next(s1, filename, sizeof(filename));
3414 for(;;) {
3415 libname[0] = '\0';
3416 if (t == LD_TOK_EOF) {
3417 tcc_error_noabort("unexpected end of file");
3418 ret = -1;
3419 goto lib_parse_error;
3420 } else if (t == ')') {
3421 break;
3422 } else if (t == '-') {
3423 t = ld_next(s1, filename, sizeof(filename));
3424 if ((t != LD_TOK_NAME) || (filename[0] != 'l')) {
3425 tcc_error_noabort("library name expected");
3426 ret = -1;
3427 goto lib_parse_error;
3428 }
3429 pstrcpy(libname, sizeof libname, &filename[1]);
3430 if (s1->static_link) {
3431 snprintf(filename, sizeof filename, "lib%s.a", libname);
3432 } else {
3433 snprintf(filename, sizeof filename, "lib%s.so", libname);
3434 }
3435 } else if (t != LD_TOK_NAME) {
3436 tcc_error_noabort("filename expected");
3437 ret = -1;
3438 goto lib_parse_error;
3439 }
3440 if (!strcmp(filename, "AS_NEEDED")) {
3441 ret = ld_add_file_list(s1, cmd, 1);
3442 if (ret)
3443 goto lib_parse_error;
3444 } else {
3445 /* TODO: Implement AS_NEEDED support. Ignore it for now */
3446 if (!as_needed) {
3447 ret = ld_add_file(s1, filename);
3448 if (ret)
3449 goto lib_parse_error;
3450 if (group) {
3451 /* Add the filename *and* the libname to avoid future conversions */
3452 dynarray_add((void ***) &libs, &nblibs, tcc_strdup(filename));
3453 if (libname[0] != '\0')
3454 dynarray_add((void ***) &libs, &nblibs, tcc_strdup(libname));
3455 }
3456 }
3457 }
3458 t = ld_next(s1, filename, sizeof(filename));
3459 if (t == ',') {
3460 t = ld_next(s1, filename, sizeof(filename));
3461 }
3462 }
3463 if (group && !as_needed) {
3464 while (new_undef_syms()) {
3465 int i;
3466
3467 for (i = 0; i < nblibs; i ++)
3468 ld_add_file(s1, libs[i]);
3469 }
3470 }
3471 lib_parse_error:
3472 dynarray_reset(&libs, &nblibs);
3473 return ret;
3474 }
3475
3476 /* interpret a subset of GNU ldscripts to handle the dummy libc.so
3477 files */
3478 ST_FUNC int tcc_load_ldscript(TCCState *s1)
3479 {
3480 char cmd[64];
3481 char filename[1024];
3482 int t, ret;
3483
3484 ch = handle_eob();
3485 for(;;) {
3486 t = ld_next(s1, cmd, sizeof(cmd));
3487 if (t == LD_TOK_EOF)
3488 return 0;
3489 else if (t != LD_TOK_NAME)
3490 return -1;
3491 if (!strcmp(cmd, "INPUT") ||
3492 !strcmp(cmd, "GROUP")) {
3493 ret = ld_add_file_list(s1, cmd, 0);
3494 if (ret)
3495 return ret;
3496 } else if (!strcmp(cmd, "OUTPUT_FORMAT") ||
3497 !strcmp(cmd, "TARGET")) {
3498 /* ignore some commands */
3499 t = ld_next(s1, cmd, sizeof(cmd));
3500 if (t != '(')
3501 expect("(");
3502 for(;;) {
3503 t = ld_next(s1, filename, sizeof(filename));
3504 if (t == LD_TOK_EOF) {
3505 tcc_error_noabort("unexpected end of file");
3506 return -1;
3507 } else if (t == ')') {
3508 break;
3509 }
3510 }
3511 } else {
3512 return -1;
3513 }
3514 }
3515 return 0;
3516 }
3517 #endif /* !TCC_TARGET_PE */
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