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fix installation amd bcheck for Windows
[tinycc.git] / tccelf.c
blobac914562d355f8d7f74e8f276404ffe3af5134e0
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", 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 *(int *)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 *(int *)ptr += val - addr;
545 break;
546 case R_386_PLT32:
547 *(int *)ptr += val - addr;
548 break;
549 case R_386_GLOB_DAT:
550 case R_386_JMP_SLOT:
551 *(int *)ptr = val;
552 break;
553 case R_386_GOTPC:
554 *(int *)ptr += s1->got->sh_addr - addr;
555 break;
556 case R_386_GOTOFF:
557 *(int *)ptr += val - s1->got->sh_addr;
558 break;
559 case R_386_GOT32:
560 /* we load the got offset */
561 *(int *)ptr += s1->sym_attrs[sym_index].got_offset;
562 break;
563 case R_386_16:
564 if (s1->output_format != TCC_OUTPUT_FORMAT_BINARY) {
565 output_file:
566 tcc_error("can only produce 16-bit binary files");
567 }
568 *(short *)ptr += val;
569 break;
570 case R_386_PC16:
571 if (s1->output_format != TCC_OUTPUT_FORMAT_BINARY)
572 goto output_file;
573 *(short *)ptr += val - addr;
574 break;
575 #elif defined(TCC_TARGET_ARM)
576 case R_ARM_PC24:
577 case R_ARM_CALL:
578 case R_ARM_JUMP24:
579 case R_ARM_PLT32:
580 {
581 int x, is_thumb, is_call, h, blx_avail, is_bl, th_ko;
582 x = (*(int *) ptr) & 0xffffff;
583 if (sym->st_shndx == SHN_UNDEF)
584 val = s1->plt->sh_addr;
585 #ifdef DEBUG_RELOC
586 printf ("reloc %d: x=0x%x val=0x%x ", type, x, val);
587 #endif
588 (*(int *)ptr) &= 0xff000000;
589 if (x & 0x800000)
590 x -= 0x1000000;
591 x <<= 2;
592 blx_avail = (TCC_ARM_VERSION >= 5);
593 is_thumb = val & 1;
594 is_bl = (*(unsigned *) ptr) >> 24 == 0xeb;
595 is_call = (type == R_ARM_CALL || (type == R_ARM_PC24 && is_bl));
596 x += val - addr;
597 #ifdef DEBUG_RELOC
598 printf (" newx=0x%x name=%s\n", x,
599 (char *) symtab_section->link->data + sym->st_name);
600 #endif
601 h = x & 2;
602 th_ko = (x & 3) && (!blx_avail || !is_call);
603 if (th_ko || x >= 0x2000000 || x < -0x2000000)
604 tcc_error("can't relocate value at %x,%d",addr, type);
605 x >>= 2;
606 x &= 0xffffff;
607 /* Only reached if blx is avail and it is a call */
608 if (is_thumb) {
609 x |= h << 24;
610 (*(int *)ptr) = 0xfa << 24; /* bl -> blx */
611 }
612 (*(int *) ptr) |= x;
613 }
614 break;
615 /* Since these relocations only concern Thumb-2 and blx instruction was
616 introduced before Thumb-2, we can assume blx is available and not
617 guard its use */
618 case R_ARM_THM_PC22:
619 case R_ARM_THM_JUMP24:
620 {
621 int x, hi, lo, s, j1, j2, i1, i2, imm10, imm11;
622 int to_thumb, is_call, to_plt, blx_bit = 1 << 12;
623 Section *plt;
624
625 /* weak reference */
626 if (sym->st_shndx == SHN_UNDEF &&
627 ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
628 break;
629
630 /* Get initial offset */
631 hi = (*(uint16_t *)ptr);
632 lo = (*(uint16_t *)(ptr+2));
633 s = (hi >> 10) & 1;
634 j1 = (lo >> 13) & 1;
635 j2 = (lo >> 11) & 1;
636 i1 = (j1 ^ s) ^ 1;
637 i2 = (j2 ^ s) ^ 1;
638 imm10 = hi & 0x3ff;
639 imm11 = lo & 0x7ff;
640 x = (s << 24) | (i1 << 23) | (i2 << 22) |
641 (imm10 << 12) | (imm11 << 1);
642 if (x & 0x01000000)
643 x -= 0x02000000;
644
645 /* Relocation infos */
646 to_thumb = val & 1;
647 plt = s1->plt;
648 to_plt = (val >= plt->sh_addr) &&
649 (val < plt->sh_addr + plt->data_offset);
650 is_call = (type == R_ARM_THM_PC22);
651
652 /* Compute final offset */
653 if (to_plt && !is_call) /* Point to 1st instr of Thumb stub */
654 x -= 4;
655 x += val - addr;
656 if (!to_thumb && is_call) {
657 blx_bit = 0; /* bl -> blx */
658 x = (x + 3) & -4; /* Compute offset from aligned PC */
659 }
660
661 /* Check that relocation is possible
662 * offset must not be out of range
663 * if target is to be entered in arm mode:
664 - bit 1 must not set
665 - instruction must be a call (bl) or a jump to PLT */
666 if (!to_thumb || x >= 0x1000000 || x < -0x1000000)
667 if (to_thumb || (val & 2) || (!is_call && !to_plt))
668 tcc_error("can't relocate value at %x,%d",addr, type);
669
670 /* Compute and store final offset */
671 s = (x >> 24) & 1;
672 i1 = (x >> 23) & 1;
673 i2 = (x >> 22) & 1;
674 j1 = s ^ (i1 ^ 1);
675 j2 = s ^ (i2 ^ 1);
676 imm10 = (x >> 12) & 0x3ff;
677 imm11 = (x >> 1) & 0x7ff;
678 (*(uint16_t *)ptr) = (uint16_t) ((hi & 0xf800) |
679 (s << 10) | imm10);
680 (*(uint16_t *)(ptr+2)) = (uint16_t) ((lo & 0xc000) |
681 (j1 << 13) | blx_bit | (j2 << 11) |
682 imm11);
683 }
684 break;
685 case R_ARM_MOVT_ABS:
686 case R_ARM_MOVW_ABS_NC:
687 {
688 int x, imm4, imm12;
689 if (type == R_ARM_MOVT_ABS)
690 val >>= 16;
691 imm12 = val & 0xfff;
692 imm4 = (val >> 12) & 0xf;
693 x = (imm4 << 16) | imm12;
694 if (type == R_ARM_THM_MOVT_ABS)
695 *(int *)ptr |= x;
696 else
697 *(int *)ptr += x;
698 }
699 break;
700 case R_ARM_THM_MOVT_ABS:
701 case R_ARM_THM_MOVW_ABS_NC:
702 {
703 int x, i, imm4, imm3, imm8;
704 if (type == R_ARM_THM_MOVT_ABS)
705 val >>= 16;
706 imm8 = val & 0xff;
707 imm3 = (val >> 8) & 0x7;
708 i = (val >> 11) & 1;
709 imm4 = (val >> 12) & 0xf;
710 x = (imm3 << 28) | (imm8 << 16) | (i << 10) | imm4;
711 if (type == R_ARM_THM_MOVT_ABS)
712 *(int *)ptr |= x;
713 else
714 *(int *)ptr += x;
715 }
716 break;
717 case R_ARM_PREL31:
718 {
719 int x;
720 x = (*(int *)ptr) & 0x7fffffff;
721 (*(int *)ptr) &= 0x80000000;
722 x = (x * 2) / 2;
723 x += val - addr;
724 if((x^(x>>1))&0x40000000)
725 tcc_error("can't relocate value at %x,%d",addr, type);
726 (*(int *)ptr) |= x & 0x7fffffff;
727 }
728 case R_ARM_ABS32:
729 *(int *)ptr += val;
730 break;
731 case R_ARM_REL32:
732 *(int *)ptr += val - addr;
733 break;
734 case R_ARM_GOTPC:
735 *(int *)ptr += s1->got->sh_addr - addr;
736 break;
737 case R_ARM_GOTOFF:
738 *(int *)ptr += val - s1->got->sh_addr;
739 break;
740 case R_ARM_GOT32:
741 /* we load the got offset */
742 *(int *)ptr += s1->sym_attrs[sym_index].got_offset;
743 break;
744 case R_ARM_COPY:
745 break;
746 case R_ARM_V4BX:
747 /* trade Thumb support for ARMv4 support */
748 if ((0x0ffffff0 & *(int*)ptr) == 0x012FFF10)
749 *(int*)ptr ^= 0xE12FFF10 ^ 0xE1A0F000; /* BX Rm -> MOV PC, Rm */
750 break;
751 case R_ARM_GLOB_DAT:
752 case R_ARM_JUMP_SLOT:
753 *(addr_t *)ptr = val;
754 break;
755 case R_ARM_NONE:
756 /* Nothing to do. Normally used to indicate a dependency
757 on a certain symbol (like for exception handling under EABI). */
758 break;
759 default:
760 fprintf(stderr,"FIXME: handle reloc type %x at %x [%p] to %x\n",
761 type, (unsigned)addr, ptr, (unsigned)val);
762 break;
763 #elif defined(TCC_TARGET_ARM64)
764 case R_AARCH64_ABS64:
765 *(uint64_t *)ptr = val;
766 break;
767 case R_AARCH64_ABS32:
768 *(uint32_t *)ptr = val;
769 break;
770 case R_AARCH64_MOVW_UABS_G0_NC:
771 *(uint32_t *)ptr = (*(uint32_t *)ptr & 0xffe0001f) |
772 (val & 0xffff) << 5;
773 break;
774 case R_AARCH64_MOVW_UABS_G1_NC:
775 *(uint32_t *)ptr = (*(uint32_t *)ptr & 0xffe0001f) |
776 (val >> 16 & 0xffff) << 5;
777 break;
778 case R_AARCH64_MOVW_UABS_G2_NC:
779 *(uint32_t *)ptr = (*(uint32_t *)ptr & 0xffe0001f) |
780 (val >> 32 & 0xffff) << 5;
781 break;
782 case R_AARCH64_MOVW_UABS_G3:
783 *(uint32_t *)ptr = (*(uint32_t *)ptr & 0xffe0001f) |
784 (val >> 48 & 0xffff) << 5;
785 break;
786 case R_AARCH64_ADR_PREL_PG_HI21: {
787 uint64_t off = (val >> 12) - (addr >> 12);
788 if ((off + ((uint64_t)1 << 20)) >> 21)
789 tcc_error("R_AARCH64_ADR_PREL_PG_HI21 relocation failed");
790 *(uint32_t *)ptr = (*(uint32_t *)ptr & 0x9f00001f) |
791 (off & 0x1ffffc) << 3 | (off & 3) << 29;
792 break;
793 }
794 case R_AARCH64_ADD_ABS_LO12_NC:
795 *(uint32_t *)ptr = (*(uint32_t *)ptr & 0xffc003ff) |
796 (val & 0xfff) << 10;
797 break;
798 case R_AARCH64_JUMP26:
799 case R_AARCH64_CALL26:
800 /* This check must match the one in build_got_entries, testing
801 if we really need a PLT slot. */
802 if (sym->st_shndx == SHN_UNDEF)
803 /* We've put the PLT slot offset into r_addend when generating
804 it, and that's what we must use as relocation value (adjusted
805 by section offset of course). */
806 val = s1->plt->sh_addr + rel->r_addend;
807 #ifdef DEBUG_RELOC
808 printf ("reloc %d @ 0x%lx: val=0x%lx name=%s\n", type, addr, val,
809 (char *) symtab_section->link->data + sym->st_name);
810 #endif
811 if (((val - addr) + ((uint64_t)1 << 27)) & ~(uint64_t)0xffffffc)
812 {
813 tcc_error("R_AARCH64_(JUMP|CALL)26 relocation failed (val=%lx, addr=%lx)", addr, val);
814 }
815 *(uint32_t *)ptr = 0x14000000 | (type == R_AARCH64_CALL26) << 31 |
816 ((val - addr) >> 2 & 0x3ffffff);
817 break;
818 case R_AARCH64_ADR_GOT_PAGE: {
819 uint64_t off =
820 (((s1->got->sh_addr +
821 s1->sym_attrs[sym_index].got_offset) >> 12) - (addr >> 12));
822 if ((off + ((uint64_t)1 << 20)) >> 21)
823 tcc_error("R_AARCH64_ADR_GOT_PAGE relocation failed");
824 *(uint32_t *)ptr = (*(uint32_t *)ptr & 0x9f00001f) |
825 (off & 0x1ffffc) << 3 | (off & 3) << 29;
826 break;
827 }
828 case R_AARCH64_LD64_GOT_LO12_NC:
829 *(uint32_t *)ptr = (*(uint32_t *)ptr & 0xfff803ff) |
830 ((s1->got->sh_addr + s1->sym_attrs[sym_index].got_offset)
831 & 0xff8) << 7;
832 break;
833 case R_AARCH64_COPY:
834 break;
835 case R_AARCH64_GLOB_DAT:
836 case R_AARCH64_JUMP_SLOT:
837 /* They don't need addend */
838 #ifdef DEBUG_RELOC
839 printf ("reloc %d @ 0x%lx: val=0x%lx name=%s\n", type, addr,
840 val - rel->r_addend,
841 (char *) symtab_section->link->data + sym->st_name);
842 #endif
843 *(addr_t *)ptr = val - rel->r_addend;
844 break;
845 default:
846 fprintf(stderr, "FIXME: handle reloc type %x at %x [%p] to %x\n",
847 type, (unsigned)addr, ptr, (unsigned)val);
848 break;
849 #elif defined(TCC_TARGET_C67)
850 case R_C60_32:
851 *(int *)ptr += val;
852 break;
853 case R_C60LO16:
854 {
855 uint32_t orig;
856
857 /* put the low 16 bits of the absolute address
858 add to what is already there */
859
860 orig = ((*(int *)(ptr )) >> 7) & 0xffff;
861 orig |= (((*(int *)(ptr+4)) >> 7) & 0xffff) << 16;
862
863 /* patch both at once - assumes always in pairs Low - High */
864
865 *(int *) ptr = (*(int *) ptr & (~(0xffff << 7)) ) | (((val+orig) & 0xffff) << 7);
866 *(int *)(ptr+4) = (*(int *)(ptr+4) & (~(0xffff << 7)) ) | ((((val+orig)>>16) & 0xffff) << 7);
867 }
868 break;
869 case R_C60HI16:
870 break;
871 default:
872 fprintf(stderr,"FIXME: handle reloc type %x at %x [%p] to %x\n",
873 type, (unsigned)addr, ptr, (unsigned)val);
874 break;
875 #elif defined(TCC_TARGET_X86_64)
876 case R_X86_64_64:
877 if (s1->output_type == TCC_OUTPUT_DLL) {
878 esym_index = s1->symtab_to_dynsym[sym_index];
879 qrel->r_offset = rel->r_offset;
880 if (esym_index) {
881 qrel->r_info = ELFW(R_INFO)(esym_index, R_X86_64_64);
882 qrel->r_addend = rel->r_addend;
883 qrel++;
884 break;
885 } else {
886 qrel->r_info = ELFW(R_INFO)(0, R_X86_64_RELATIVE);
887 qrel->r_addend = *(long long *)ptr + val;
888 qrel++;
889 }
890 }
891 *(long long *)ptr += val;
892 break;
893 case R_X86_64_32:
894 case R_X86_64_32S:
895 if (s1->output_type == TCC_OUTPUT_DLL) {
896 /* XXX: this logic may depend on TCC's codegen
897 now TCC uses R_X86_64_32 even for a 64bit pointer */
898 qrel->r_info = ELFW(R_INFO)(0, R_X86_64_RELATIVE);
899 qrel->r_addend = *(int *)ptr + val;
900 qrel++;
901 }
902 *(int *)ptr += val;
903 break;
904
905 case R_X86_64_PC32:
906 if (s1->output_type == TCC_OUTPUT_DLL) {
907 /* DLL relocation */
908 esym_index = s1->symtab_to_dynsym[sym_index];
909 if (esym_index) {
910 qrel->r_offset = rel->r_offset;
911 qrel->r_info = ELFW(R_INFO)(esym_index, R_X86_64_PC32);
912 qrel->r_addend = *(int *)ptr;
913 qrel++;
914 break;
915 }
916 }
917 goto plt32pc32;
918
919 case R_X86_64_PLT32:
920 /* We've put the PLT slot offset into r_addend when generating
921 it, and that's what we must use as relocation value (adjusted
922 by section offset of course). */
923 val = s1->plt->sh_addr + rel->r_addend;
924 /* fallthrough. */
925
926 plt32pc32:
927 {
928 long long diff;
929 diff = (long long)val - addr;
930 if (diff < -2147483648LL || diff > 2147483647LL) {
931 tcc_error("internal error: relocation failed");
932 }
933 *(int *)ptr += diff;
934 }
935 break;
936 case R_X86_64_GLOB_DAT:
937 case R_X86_64_JUMP_SLOT:
938 /* They don't need addend */
939 *(addr_t *)ptr = val - rel->r_addend;
940 break;
941 case R_X86_64_GOTPCREL:
942 *(int *)ptr += (s1->got->sh_addr - addr +
943 s1->sym_attrs[sym_index].got_offset - 4);
944 break;
945 case R_X86_64_GOTTPOFF:
946 *(int *)ptr += val - s1->got->sh_addr;
947 break;
948 case R_X86_64_GOT32:
949 /* we load the got offset */
950 *(int *)ptr += s1->sym_attrs[sym_index].got_offset;
951 break;
952 #else
953 #error unsupported processor
954 #endif
955 }
956 }
957 /* if the relocation is allocated, we change its symbol table */
958 if (sr->sh_flags & SHF_ALLOC)
959 sr->link = s1->dynsym;
960 }
961
962 /* relocate relocation table in 'sr' */
963 static void relocate_rel(TCCState *s1, Section *sr)
964 {
965 Section *s;
966 ElfW_Rel *rel;
967
968 s = s1->sections[sr->sh_info];
969 for_each_elem(sr, 0, rel, ElfW_Rel)
970 rel->r_offset += s->sh_addr;
971 }
972
973 /* count the number of dynamic relocations so that we can reserve
974 their space */
975 static int prepare_dynamic_rel(TCCState *s1, Section *sr)
976 {
977 ElfW_Rel *rel;
978 int sym_index, esym_index, type, count;
979
980 count = 0;
981 for_each_elem(sr, 0, rel, ElfW_Rel) {
982 sym_index = ELFW(R_SYM)(rel->r_info);
983 type = ELFW(R_TYPE)(rel->r_info);
984 switch(type) {
985 #if defined(TCC_TARGET_I386)
986 case R_386_32:
987 #elif defined(TCC_TARGET_X86_64)
988 case R_X86_64_32:
989 case R_X86_64_32S:
990 case R_X86_64_64:
991 #endif
992 count++;
993 break;
994 #if defined(TCC_TARGET_I386)
995 case R_386_PC32:
996 #elif defined(TCC_TARGET_X86_64)
997 case R_X86_64_PC32:
998 #endif
999 esym_index = s1->symtab_to_dynsym[sym_index];
1000 if (esym_index)
1001 count++;
1002 break;
1003 default:
1004 break;
1005 }
1006 }
1007 if (count) {
1008 /* allocate the section */
1009 sr->sh_flags |= SHF_ALLOC;
1010 sr->sh_size = count * sizeof(ElfW_Rel);
1011 }
1012 return count;
1013 }
1014
1015 static struct sym_attr *alloc_sym_attr(TCCState *s1, int index)
1016 {
1017 int n;
1018 struct sym_attr *tab;
1019
1020 if (index >= s1->nb_sym_attrs) {
1021 /* find immediately bigger power of 2 and reallocate array */
1022 n = 1;
1023 while (index >= n)
1024 n *= 2;
1025 tab = tcc_realloc(s1->sym_attrs, n * sizeof(*s1->sym_attrs));
1026 s1->sym_attrs = tab;
1027 memset(s1->sym_attrs + s1->nb_sym_attrs, 0,
1028 (n - s1->nb_sym_attrs) * sizeof(*s1->sym_attrs));
1029 s1->nb_sym_attrs = n;
1030 }
1031 return &s1->sym_attrs[index];
1032 }
1033
1034 /* XXX: suppress that */
1035 static void put32(unsigned char *p, uint32_t val)
1036 {
1037 p[0] = val;
1038 p[1] = val >> 8;
1039 p[2] = val >> 16;
1040 p[3] = val >> 24;
1041 }
1042
1043 #if defined(TCC_TARGET_I386) || defined(TCC_TARGET_ARM) || \
1044 defined(TCC_TARGET_ARM64) || defined(TCC_TARGET_X86_64)
1045 static uint32_t get32(unsigned char *p)
1046 {
1047 return p[0] | (p[1] << 8) | (p[2] << 16) | (p[3] << 24);
1048 }
1049 #endif
1050
1051 static void build_got(TCCState *s1)
1052 {
1053 unsigned char *ptr;
1054
1055 /* if no got, then create it */
1056 s1->got = new_section(s1, ".got", SHT_PROGBITS, SHF_ALLOC | SHF_WRITE);
1057 s1->got->sh_entsize = 4;
1058 add_elf_sym(symtab_section, 0, 4, ELFW(ST_INFO)(STB_GLOBAL, STT_OBJECT),
1059 0, s1->got->sh_num, "_GLOBAL_OFFSET_TABLE_");
1060 ptr = section_ptr_add(s1->got, 3 * PTR_SIZE);
1061 #if PTR_SIZE == 4
1062 /* keep space for _DYNAMIC pointer, if present */
1063 put32(ptr, 0);
1064 /* two dummy got entries */
1065 put32(ptr + 4, 0);
1066 put32(ptr + 8, 0);
1067 #else
1068 /* keep space for _DYNAMIC pointer, if present */
1069 put32(ptr, 0);
1070 put32(ptr + 4, 0);
1071 /* two dummy got entries */
1072 put32(ptr + 8, 0);
1073 put32(ptr + 12, 0);
1074 put32(ptr + 16, 0);
1075 put32(ptr + 20, 0);
1076 #endif
1077 }
1078
1079 /* put a got or plt entry corresponding to a symbol in symtab_section. 'size'
1080 and 'info' can be modifed if more precise info comes from the DLL.
1081 Returns offset of GOT or PLT slot. */
1082 static unsigned long put_got_entry(TCCState *s1,
1083 int reloc_type, unsigned long size, int info,
1084 int sym_index)
1085 {
1086 int index, need_plt_entry;
1087 const char *name;
1088 ElfW(Sym) *sym;
1089 unsigned long offset;
1090 int *ptr;
1091 struct sym_attr *symattr;
1092
1093 if (!s1->got)
1094 build_got(s1);
1095
1096 need_plt_entry =
1097 #ifdef TCC_TARGET_X86_64
1098 (reloc_type == R_X86_64_JUMP_SLOT);
1099 #elif defined(TCC_TARGET_I386)
1100 (reloc_type == R_386_JMP_SLOT);
1101 #elif defined(TCC_TARGET_ARM)
1102 (reloc_type == R_ARM_JUMP_SLOT);
1103 #elif defined(TCC_TARGET_ARM64)
1104 (reloc_type == R_AARCH64_JUMP_SLOT);
1105 #else
1106 0;
1107 #endif
1108
1109 if (need_plt_entry && !s1->plt) {
1110 /* add PLT */
1111 s1->plt = new_section(s1, ".plt", SHT_PROGBITS,
1112 SHF_ALLOC | SHF_EXECINSTR);
1113 s1->plt->sh_entsize = 4;
1114 }
1115
1116 /* If a got/plt entry already exists for that symbol, no need to add one */
1117 if (sym_index < s1->nb_sym_attrs) {
1118 if (need_plt_entry && s1->sym_attrs[sym_index].plt_offset)
1119 return s1->sym_attrs[sym_index].plt_offset;
1120 else if (!need_plt_entry && s1->sym_attrs[sym_index].got_offset)
1121 return s1->sym_attrs[sym_index].got_offset;
1122 }
1123
1124 symattr = alloc_sym_attr(s1, sym_index);
1125
1126 /* Only store the GOT offset if it's not generated for the PLT entry. */
1127 if (!need_plt_entry)
1128 symattr->got_offset = s1->got->data_offset;
1129
1130 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1131 name = (char *) symtab_section->link->data + sym->st_name;
1132 offset = sym->st_value;
1133 #if defined(TCC_TARGET_I386) || defined(TCC_TARGET_X86_64)
1134 if (need_plt_entry) {
1135 Section *plt;
1136 uint8_t *p;
1137 int modrm;
1138 unsigned long relofs;
1139
1140 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
1141 modrm = 0x25;
1142 #else
1143 /* if we build a DLL, we add a %ebx offset */
1144 if (s1->output_type == TCC_OUTPUT_DLL)
1145 modrm = 0xa3;
1146 else
1147 modrm = 0x25;
1148 #endif
1149
1150 /* add a PLT entry */
1151 plt = s1->plt;
1152 if (plt->data_offset == 0) {
1153 /* first plt entry */
1154 p = section_ptr_add(plt, 16);
1155 p[0] = 0xff; /* pushl got + PTR_SIZE */
1156 p[1] = modrm + 0x10;
1157 put32(p + 2, PTR_SIZE);
1158 p[6] = 0xff; /* jmp *(got + PTR_SIZE * 2) */
1159 p[7] = modrm;
1160 put32(p + 8, PTR_SIZE * 2);
1161 }
1162
1163 /* The PLT slot refers to the relocation entry it needs
1164 via offset. The reloc entry is created below, so its
1165 offset is the current data_offset. */
1166 relofs = s1->got->reloc ? s1->got->reloc->data_offset : 0;
1167 symattr->plt_offset = plt->data_offset;
1168 p = section_ptr_add(plt, 16);
1169 p[0] = 0xff; /* jmp *(got + x) */
1170 p[1] = modrm;
1171 put32(p + 2, s1->got->data_offset);
1172 p[6] = 0x68; /* push $xxx */
1173 #ifdef TCC_TARGET_X86_64
1174 /* On x86-64, the relocation is referred to by _index_. */
1175 put32(p + 7, relofs / sizeof (ElfW_Rel));
1176 #else
1177 put32(p + 7, relofs);
1178 #endif
1179 p[11] = 0xe9; /* jmp plt_start */
1180 put32(p + 12, -(plt->data_offset));
1181
1182 /* If this was an UNDEF symbol set the offset in the
1183 dynsymtab to the PLT slot, so that PC32 relocs to it
1184 can be resolved. */
1185 if (sym->st_shndx == SHN_UNDEF)
1186 offset = plt->data_offset - 16;
1187 }
1188 #elif defined(TCC_TARGET_ARM)
1189 if (need_plt_entry) {
1190 Section *plt;
1191 uint8_t *p;
1192
1193 /* if we build a DLL, we add a %ebx offset */
1194 if (s1->output_type == TCC_OUTPUT_DLL)
1195 tcc_error("DLLs unimplemented!");
1196
1197 /* add a PLT entry */
1198 plt = s1->plt;
1199 if (plt->data_offset == 0) {
1200 /* first plt entry */
1201 p = section_ptr_add(plt, 16);
1202 put32(p, 0xe52de004); /* push {lr} */
1203 put32(p+4, 0xe59fe010); /* ldr lr, [pc, #16] */
1204 put32(p+8, 0xe08fe00e); /* add lr, pc, lr */
1205 put32(p+12, 0xe5bef008); /* ldr pc, [lr, #8]! */
1206 }
1207
1208 symattr->plt_offset = plt->data_offset;
1209 if (symattr->plt_thumb_stub) {
1210 p = section_ptr_add(plt, 20);
1211 put32(p, 0x4778); /* bx pc */
1212 put32(p+2, 0x46c0); /* nop */
1213 p += 4;
1214 } else
1215 p = section_ptr_add(plt, 16);
1216 put32(p, 0xe59fc004); /* ldr ip, [pc, #4] ; GOT entry offset */
1217 put32(p+4, 0xe08fc00c); /* add ip, pc, ip ; addr of GOT entry */
1218 put32(p+8, 0xe59cf000); /* ldr pc, [ip] ; jump to GOT entry */
1219 put32(p+12, s1->got->data_offset); /* GOT entry off once patched */
1220
1221 /* the symbol is modified so that it will be relocated to
1222 the PLT */
1223 if (sym->st_shndx == SHN_UNDEF)
1224 offset = plt->data_offset - 16;
1225 }
1226 #elif defined(TCC_TARGET_ARM64)
1227 if (need_plt_entry) {
1228 Section *plt;
1229 uint8_t *p;
1230
1231 if (s1->output_type == TCC_OUTPUT_DLL)
1232 tcc_error("DLLs unimplemented!");
1233
1234 plt = s1->plt;
1235 if (plt->data_offset == 0)
1236 section_ptr_add(plt, 32);
1237 symattr->plt_offset = plt->data_offset;
1238 p = section_ptr_add(plt, 16);
1239 put32(p, s1->got->data_offset);
1240 put32(p + 4, (uint64_t)s1->got->data_offset >> 32);
1241
1242 if (sym->st_shndx == SHN_UNDEF)
1243 offset = plt->data_offset - 16;
1244 }
1245 #elif defined(TCC_TARGET_C67)
1246 if (s1->dynsym) {
1247 tcc_error("C67 got not implemented");
1248 }
1249 #else
1250 #error unsupported CPU
1251 #endif
1252 if (s1->dynsym) {
1253 /* XXX This might generate multiple syms for name. */
1254 index = put_elf_sym(s1->dynsym, offset,
1255 size, info, 0, sym->st_shndx, name);
1256 /* Create the relocation (it's against the GOT for PLT
1257 and GOT relocs). */
1258 put_elf_reloc(s1->dynsym, s1->got,
1259 s1->got->data_offset,
1260 reloc_type, index);
1261 } else {
1262 /* Without .dynsym (i.e. static link or memory output) we
1263 still need relocs against the generated got, so as to fill
1264 the entries with the symbol values (determined later). */
1265 put_elf_reloc(symtab_section, s1->got,
1266 s1->got->data_offset,
1267 reloc_type, sym_index);
1268 }
1269 /* And now create the GOT slot itself. */
1270 ptr = section_ptr_add(s1->got, PTR_SIZE);
1271 *ptr = 0;
1272 if (need_plt_entry)
1273 return symattr->plt_offset;
1274 else
1275 return symattr->got_offset;
1276 }
1277
1278 /* build GOT and PLT entries */
1279 ST_FUNC void build_got_entries(TCCState *s1)
1280 {
1281 Section *s;
1282 ElfW_Rel *rel;
1283 ElfW(Sym) *sym;
1284 int i, type, reloc_type, sym_index;
1285
1286 for(i = 1; i < s1->nb_sections; i++) {
1287 s = s1->sections[i];
1288 if (s->sh_type != SHT_RELX)
1289 continue;
1290 /* no need to handle got relocations */
1291 if (s->link != symtab_section)
1292 continue;
1293 for_each_elem(s, 0, rel, ElfW_Rel) {
1294 type = ELFW(R_TYPE)(rel->r_info);
1295 switch(type) {
1296 #if defined(TCC_TARGET_I386)
1297 case R_386_GOT32:
1298 case R_386_GOTOFF:
1299 case R_386_GOTPC:
1300 case R_386_PLT32:
1301 if (!s1->got)
1302 build_got(s1);
1303 if (type == R_386_GOT32 || type == R_386_PLT32) {
1304 sym_index = ELFW(R_SYM)(rel->r_info);
1305 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1306 /* look at the symbol got offset. If none, then add one */
1307 if (type == R_386_GOT32)
1308 reloc_type = R_386_GLOB_DAT;
1309 else
1310 reloc_type = R_386_JMP_SLOT;
1311 put_got_entry(s1, reloc_type, sym->st_size, sym->st_info,
1312 sym_index);
1313 }
1314 break;
1315 #elif defined(TCC_TARGET_ARM)
1316 case R_ARM_PC24:
1317 case R_ARM_CALL:
1318 case R_ARM_JUMP24:
1319 case R_ARM_GOT32:
1320 case R_ARM_GOTOFF:
1321 case R_ARM_GOTPC:
1322 case R_ARM_PLT32:
1323 if (!s1->got)
1324 build_got(s1);
1325 sym_index = ELFW(R_SYM)(rel->r_info);
1326 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1327 if (type != R_ARM_GOTOFF && type != R_ARM_GOTPC
1328 && sym->st_shndx == SHN_UNDEF) {
1329 unsigned long ofs;
1330 /* look at the symbol got offset. If none, then add one */
1331 if (type == R_ARM_GOT32)
1332 reloc_type = R_ARM_GLOB_DAT;
1333 else
1334 reloc_type = R_ARM_JUMP_SLOT;
1335 ofs = put_got_entry(s1, reloc_type, sym->st_size,
1336 sym->st_info, sym_index);
1337 #ifdef DEBUG_RELOC
1338 printf ("maybegot: %s, %d, %d --> ofs=0x%x\n",
1339 (char *) symtab_section->link->data + sym->st_name,
1340 type, sym->st_shndx, ofs);
1341 #endif
1342 if (type != R_ARM_GOT32) {
1343 addr_t *ptr = (addr_t*)(s1->sections[s->sh_info]->data
1344 + rel->r_offset);
1345 /* x must be signed! */
1346 int x = *ptr & 0xffffff;
1347 x = (x << 8) >> 8;
1348 x <<= 2;
1349 x += ofs;
1350 x >>= 2;
1351 #ifdef DEBUG_RELOC
1352 printf ("insn=0x%x --> 0x%x (x==0x%x)\n", *ptr,
1353 (*ptr & 0xff000000) | x, x);
1354 #endif
1355 *ptr = (*ptr & 0xff000000) | x;
1356 }
1357 }
1358 break;
1359 case R_ARM_THM_JUMP24:
1360 sym_index = ELFW(R_SYM)(rel->r_info);
1361 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1362 /* We are relocating a jump from thumb code to arm code */
1363 if (sym->st_shndx != SHN_UNDEF && !(sym->st_value & 1)) {
1364 int index;
1365 uint8_t *p;
1366 char *name, buf[1024];
1367 Section *text_section;
1368
1369 name = (char *) symtab_section->link->data + sym->st_name;
1370 text_section = s1->sections[sym->st_shndx];
1371 /* Modify reloc to target a thumb stub to switch to ARM */
1372 snprintf(buf, sizeof(buf), "%s_from_thumb", name);
1373 index = put_elf_sym(symtab_section,
1374 text_section->data_offset + 1,
1375 sym->st_size, sym->st_info, 0,
1376 sym->st_shndx, buf);
1377 rel->r_info = ELFW(R_INFO)(index, type);
1378 /* Create a thumb stub fonction to switch to ARM mode */
1379 put_elf_reloc(symtab_section, text_section,
1380 text_section->data_offset + 4, R_ARM_JUMP24,
1381 sym_index);
1382 p = section_ptr_add(text_section, 8);
1383 put32(p, 0x4778); /* bx pc */
1384 put32(p+2, 0x46c0); /* nop */
1385 put32(p+4, 0xeafffffe); /* b $sym */
1386 }
1387 #elif defined(TCC_TARGET_ARM64)
1388 //xx Other cases may be required here:
1389 case R_AARCH64_ADR_GOT_PAGE:
1390 case R_AARCH64_LD64_GOT_LO12_NC:
1391 if (!s1->got)
1392 build_got(s1);
1393 sym_index = ELFW(R_SYM)(rel->r_info);
1394 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1395 reloc_type = R_AARCH64_GLOB_DAT;
1396 put_got_entry(s1, reloc_type, sym->st_size, sym->st_info,
1397 sym_index);
1398 break;
1399
1400 case R_AARCH64_JUMP26:
1401 case R_AARCH64_CALL26:
1402 if (!s1->got)
1403 build_got(s1);
1404 sym_index = ELFW(R_SYM)(rel->r_info);
1405 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1406 if (sym->st_shndx == SHN_UNDEF) {
1407 unsigned long ofs;
1408 reloc_type = R_AARCH64_JUMP_SLOT;
1409 ofs = put_got_entry(s1, reloc_type, sym->st_size,
1410 sym->st_info, sym_index);
1411 /* We store the place of the generated PLT slot
1412 in our addend. */
1413 rel->r_addend += ofs;
1414 }
1415 break;
1416 #elif defined(TCC_TARGET_C67)
1417 case R_C60_GOT32:
1418 case R_C60_GOTOFF:
1419 case R_C60_GOTPC:
1420 case R_C60_PLT32:
1421 if (!s1->got)
1422 build_got(s1);
1423 if (type == R_C60_GOT32 || type == R_C60_PLT32) {
1424 sym_index = ELFW(R_SYM)(rel->r_info);
1425 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1426 /* look at the symbol got offset. If none, then add one */
1427 if (type == R_C60_GOT32)
1428 reloc_type = R_C60_GLOB_DAT;
1429 else
1430 reloc_type = R_C60_JMP_SLOT;
1431 put_got_entry(s1, reloc_type, sym->st_size, sym->st_info,
1432 sym_index);
1433 }
1434 break;
1435 #elif defined(TCC_TARGET_X86_64)
1436 case R_X86_64_GOT32:
1437 case R_X86_64_GOTTPOFF:
1438 case R_X86_64_GOTPCREL:
1439 case R_X86_64_PLT32:
1440 sym_index = ELFW(R_SYM)(rel->r_info);
1441 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1442 if (type == R_X86_64_PLT32 &&
1443 ELFW(ST_VISIBILITY)(sym->st_other) != STV_DEFAULT)
1444 {
1445 rel->r_info = ELFW(R_INFO)(sym_index, R_X86_64_PC32);
1446 break;
1447 }
1448
1449 if (!s1->got)
1450 build_got(s1);
1451 if (type == R_X86_64_GOT32 || type == R_X86_64_GOTPCREL ||
1452 type == R_X86_64_PLT32) {
1453 unsigned long ofs;
1454 /* look at the symbol got offset. If none, then add one */
1455 if (type == R_X86_64_GOT32 || type == R_X86_64_GOTPCREL)
1456 reloc_type = R_X86_64_GLOB_DAT;
1457 else
1458 reloc_type = R_X86_64_JUMP_SLOT;
1459 ofs = put_got_entry(s1, reloc_type, sym->st_size,
1460 sym->st_info, sym_index);
1461 if (type == R_X86_64_PLT32)
1462 /* We store the place of the generated PLT slot
1463 in our addend. */
1464 rel->r_addend += ofs;
1465 }
1466 break;
1467 #else
1468 #error unsupported CPU
1469 #endif
1470 default:
1471 break;
1472 }
1473 }
1474 }
1475 }
1476
1477 ST_FUNC Section *new_symtab(TCCState *s1,
1478 const char *symtab_name, int sh_type, int sh_flags,
1479 const char *strtab_name,
1480 const char *hash_name, int hash_sh_flags)
1481 {
1482 Section *symtab, *strtab, *hash;
1483 int *ptr, nb_buckets;
1484
1485 symtab = new_section(s1, symtab_name, sh_type, sh_flags);
1486 symtab->sh_entsize = sizeof(ElfW(Sym));
1487 strtab = new_section(s1, strtab_name, SHT_STRTAB, sh_flags);
1488 put_elf_str(strtab, "");
1489 symtab->link = strtab;
1490 put_elf_sym(symtab, 0, 0, 0, 0, 0, NULL);
1491
1492 nb_buckets = 1;
1493
1494 hash = new_section(s1, hash_name, SHT_HASH, hash_sh_flags);
1495 hash->sh_entsize = sizeof(int);
1496 symtab->hash = hash;
1497 hash->link = symtab;
1498
1499 ptr = section_ptr_add(hash, (2 + nb_buckets + 1) * sizeof(int));
1500 ptr[0] = nb_buckets;
1501 ptr[1] = 1;
1502 memset(ptr + 2, 0, (nb_buckets + 1) * sizeof(int));
1503 return symtab;
1504 }
1505
1506 /* put dynamic tag */
1507 static void put_dt(Section *dynamic, int dt, addr_t val)
1508 {
1509 ElfW(Dyn) *dyn;
1510 dyn = section_ptr_add(dynamic, sizeof(ElfW(Dyn)));
1511 dyn->d_tag = dt;
1512 dyn->d_un.d_val = val;
1513 }
1514
1515 static void add_init_array_defines(TCCState *s1, const char *section_name)
1516 {
1517 Section *s;
1518 long end_offset;
1519 char sym_start[1024];
1520 char sym_end[1024];
1521
1522 snprintf(sym_start, sizeof(sym_start), "__%s_start", section_name + 1);
1523 snprintf(sym_end, sizeof(sym_end), "__%s_end", section_name + 1);
1524
1525 s = find_section(s1, section_name);
1526 if (!s) {
1527 end_offset = 0;
1528 s = data_section;
1529 } else {
1530 end_offset = s->data_offset;
1531 }
1532
1533 add_elf_sym(symtab_section,
1534 0, 0,
1535 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1536 s->sh_num, sym_start);
1537 add_elf_sym(symtab_section,
1538 end_offset, 0,
1539 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1540 s->sh_num, sym_end);
1541 }
1542
1543 static int tcc_add_support(TCCState *s1, const char *filename)
1544 {
1545 char buf[1024];
1546 snprintf(buf, sizeof(buf), "%s/%s/%s", s1->tcc_lib_path,
1547 /* an cpu specific path inside tcc_lib_path, mainly for keeping libtcc1.a */
1548 #ifdef TCC_TARGET_I386
1549 "i386"
1550 #endif
1551 #ifdef TCC_TARGET_X86_64
1552 "x86-64"
1553 #endif
1554 #ifdef TCC_TARGET_ARM
1555 "arm"
1556 #endif
1557 #ifdef TCC_TARGET_ARM64
1558 "arm64"
1559 #endif
1560 #ifdef TCC_TARGET_C67
1561 "C67"
1562 #endif
1563 ,filename);
1564
1565 return tcc_add_file(s1, buf);
1566 }
1567
1568 ST_FUNC void tcc_add_bcheck(TCCState *s1)
1569 {
1570 #ifdef CONFIG_TCC_BCHECK
1571 addr_t *ptr;
1572
1573 if (0 == s1->do_bounds_check)
1574 return;
1575
1576 /* XXX: add an object file to do that */
1577 ptr = section_ptr_add(bounds_section, sizeof(*ptr));
1578 *ptr = 0;
1579 add_elf_sym(symtab_section, 0, 0,
1580 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1581 bounds_section->sh_num, "__bounds_start");
1582 #ifdef TCC_TARGET_I386
1583 if (s1->output_type != TCC_OUTPUT_MEMORY) {
1584 /* add 'call __bound_init()' in .init section */
1585
1586 /* XXX not called on MSYS, reason is unknown. For this
1587 case a call to __bound_init is performed in bcheck.c
1588 when __bound_ptr_add, __bound_new_region,
1589 __bound_delete_region called */
1590
1591 int sym_index = find_elf_sym(symtab_section, "__bound_init");
1592 if (sym_index) {
1593 Section *init_section = find_section(s1, ".init");
1594 unsigned char *pinit = section_ptr_add(init_section, 5);
1595 pinit[0] = 0xe8;
1596 put32(pinit + 1, -4);
1597 put_elf_reloc(symtab_section, init_section,
1598 init_section->data_offset - 4, R_386_PC32, sym_index);
1599 }
1600 else
1601 tcc_warning("__bound_init not defined");
1602 }
1603 #endif
1604 #endif
1605 }
1606
1607 /* add tcc runtime libraries */
1608 ST_FUNC void tcc_add_runtime(TCCState *s1)
1609 {
1610 /* add libc */
1611 if (!s1->nostdlib) {
1612 tcc_add_library(s1, "c");
1613 #ifdef CONFIG_USE_LIBGCC
1614 if (!s1->static_link) {
1615 tcc_add_file(s1, TCC_LIBGCC);
1616 }
1617 #endif
1618 tcc_add_support(s1, "libtcc1.a");
1619 }
1620
1621 /* tcc_add_bcheck tries to relocate a call to __bound_init in _init so
1622 libtcc1.a must be loaded before for __bound_init to be defined and
1623 crtn.o must be loaded after to not finalize _init too early. */
1624 tcc_add_bcheck(s1);
1625
1626 if (!s1->nostdlib) {
1627 /* add crt end if not memory output */
1628 if (s1->output_type != TCC_OUTPUT_MEMORY)
1629 tcc_add_crt(s1, "crtn.o");
1630 }
1631 }
1632
1633 /* add various standard linker symbols (must be done after the
1634 sections are filled (for example after allocating common
1635 symbols)) */
1636 ST_FUNC void tcc_add_linker_symbols(TCCState *s1)
1637 {
1638 char buf[1024];
1639 int i;
1640 Section *s;
1641
1642 add_elf_sym(symtab_section,
1643 text_section->data_offset, 0,
1644 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1645 text_section->sh_num, "_etext");
1646 add_elf_sym(symtab_section,
1647 data_section->data_offset, 0,
1648 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1649 data_section->sh_num, "_edata");
1650 add_elf_sym(symtab_section,
1651 bss_section->data_offset, 0,
1652 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1653 bss_section->sh_num, "_end");
1654 /* horrible new standard ldscript defines */
1655 add_init_array_defines(s1, ".preinit_array");
1656 add_init_array_defines(s1, ".init_array");
1657 add_init_array_defines(s1, ".fini_array");
1658
1659 /* add start and stop symbols for sections whose name can be
1660 expressed in C */
1661 for(i = 1; i < s1->nb_sections; i++) {
1662 s = s1->sections[i];
1663 if (s->sh_type == SHT_PROGBITS &&
1664 (s->sh_flags & SHF_ALLOC)) {
1665 const char *p;
1666 int ch;
1667
1668 /* check if section name can be expressed in C */
1669 p = s->name;
1670 for(;;) {
1671 ch = *p;
1672 if (!ch)
1673 break;
1674 if (!isid(ch) && !isnum(ch))
1675 goto next_sec;
1676 p++;
1677 }
1678 snprintf(buf, sizeof(buf), "__start_%s", s->name);
1679 add_elf_sym(symtab_section,
1680 0, 0,
1681 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1682 s->sh_num, buf);
1683 snprintf(buf, sizeof(buf), "__stop_%s", s->name);
1684 add_elf_sym(symtab_section,
1685 s->data_offset, 0,
1686 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1687 s->sh_num, buf);
1688 }
1689 next_sec: ;
1690 }
1691 }
1692
1693 static void tcc_output_binary(TCCState *s1, FILE *f,
1694 const int *sec_order)
1695 {
1696 Section *s;
1697 int i, offset, size;
1698
1699 offset = 0;
1700 for(i=1;i<s1->nb_sections;i++) {
1701 s = s1->sections[sec_order[i]];
1702 if (s->sh_type != SHT_NOBITS &&
1703 (s->sh_flags & SHF_ALLOC)) {
1704 while (offset < s->sh_offset) {
1705 fputc(0, f);
1706 offset++;
1707 }
1708 size = s->sh_size;
1709 fwrite(s->data, 1, size, f);
1710 offset += size;
1711 }
1712 }
1713 }
1714
1715 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1716 #define HAVE_PHDR 1
1717 #define EXTRA_RELITEMS 14
1718
1719 /* move the relocation value from .dynsym to .got */
1720 void patch_dynsym_undef(TCCState *s1, Section *s)
1721 {
1722 uint32_t *gotd = (void *)s1->got->data;
1723 ElfW(Sym) *sym;
1724
1725 gotd += 3; /* dummy entries in .got */
1726 /* relocate symbols in .dynsym */
1727 for_each_elem(s, 1, sym, ElfW(Sym)) {
1728 if (sym->st_shndx == SHN_UNDEF) {
1729 *gotd++ = sym->st_value + 6; /* XXX 6 is magic ? */
1730 sym->st_value = 0;
1731 }
1732 }
1733 }
1734 #else
1735 #define HAVE_PHDR 1
1736 #define EXTRA_RELITEMS 9
1737
1738 /* zero plt offsets of weak symbols in .dynsym */
1739 void patch_dynsym_undef(TCCState *s1, Section *s)
1740 {
1741 ElfW(Sym) *sym;
1742
1743 for_each_elem(s, 1, sym, ElfW(Sym))
1744 if (sym->st_shndx == SHN_UNDEF && ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
1745 sym->st_value = 0;
1746 }
1747 #endif
1748
1749 ST_FUNC void fill_got_entry(TCCState *s1, ElfW_Rel *rel)
1750 {
1751 int sym_index = ELFW(R_SYM) (rel->r_info);
1752 ElfW(Sym) *sym = &((ElfW(Sym) *) symtab_section->data)[sym_index];
1753 unsigned long offset;
1754
1755 if (sym_index >= s1->nb_sym_attrs)
1756 return;
1757 offset = s1->sym_attrs[sym_index].got_offset;
1758 section_reserve(s1->got, offset + PTR_SIZE);
1759 #ifdef TCC_TARGET_X86_64
1760 /* only works for x86-64 */
1761 put32(s1->got->data + offset + 4, sym->st_value >> 32);
1762 #endif
1763 put32(s1->got->data + offset, sym->st_value & 0xffffffff);
1764 }
1765
1766 /* Perform relocation to GOT or PLT entries */
1767 ST_FUNC void fill_got(TCCState *s1)
1768 {
1769 Section *s;
1770 ElfW_Rel *rel;
1771 int i;
1772
1773 for(i = 1; i < s1->nb_sections; i++) {
1774 s = s1->sections[i];
1775 if (s->sh_type != SHT_RELX)
1776 continue;
1777 /* no need to handle got relocations */
1778 if (s->link != symtab_section)
1779 continue;
1780 for_each_elem(s, 0, rel, ElfW_Rel) {
1781 switch (ELFW(R_TYPE) (rel->r_info)) {
1782 case R_X86_64_GOT32:
1783 case R_X86_64_GOTPCREL:
1784 case R_X86_64_PLT32:
1785 fill_got_entry(s1, rel);
1786 break;
1787 }
1788 }
1789 }
1790 }
1791
1792 /* Bind symbols of executable: resolve undefined symbols from exported symbols
1793 in shared libraries and export non local defined symbols to shared libraries
1794 if -rdynamic switch was given on command line */
1795 static void bind_exe_dynsyms(TCCState *s1)
1796 {
1797 const char *name;
1798 int sym_index, index;
1799 ElfW(Sym) *sym, *esym;
1800 int type;
1801
1802 /* Resolve undefined symbols from dynamic symbols. When there is a match:
1803 - if STT_FUNC or STT_GNU_IFUNC symbol -> add it in PLT
1804 - if STT_OBJECT symbol -> add it in .bss section with suitable reloc */
1805 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
1806 if (sym->st_shndx == SHN_UNDEF) {
1807 name = (char *) symtab_section->link->data + sym->st_name;
1808 sym_index = find_elf_sym(s1->dynsymtab_section, name);
1809 if (sym_index) {
1810 esym = &((ElfW(Sym) *)s1->dynsymtab_section->data)[sym_index];
1811 type = ELFW(ST_TYPE)(esym->st_info);
1812 if ((type == STT_FUNC) || (type == STT_GNU_IFUNC)) {
1813 /* Indirect functions shall have STT_FUNC type in executable
1814 * dynsym section. Indeed, a dlsym call following a lazy
1815 * resolution would pick the symbol value from the
1816 * executable dynsym entry which would contain the address
1817 * of the function wanted by the caller of dlsym instead of
1818 * the address of the function that would return that
1819 * address */
1820 put_got_entry(s1, R_JMP_SLOT, esym->st_size,
1821 ELFW(ST_INFO)(STB_GLOBAL,STT_FUNC),
1822 sym - (ElfW(Sym) *)symtab_section->data);
1823 } else if (type == STT_OBJECT) {
1824 unsigned long offset;
1825 ElfW(Sym) *dynsym;
1826 offset = bss_section->data_offset;
1827 /* XXX: which alignment ? */
1828 offset = (offset + 16 - 1) & -16;
1829 index = put_elf_sym(s1->dynsym, offset, esym->st_size,
1830 esym->st_info, 0, bss_section->sh_num,
1831 name);
1832 /* Ensure R_COPY works for weak symbol aliases */
1833 if (ELFW(ST_BIND)(esym->st_info) == STB_WEAK) {
1834 for_each_elem(s1->dynsymtab_section, 1, dynsym, ElfW(Sym)) {
1835 if ((dynsym->st_value == esym->st_value)
1836 && (ELFW(ST_BIND)(dynsym->st_info) == STB_GLOBAL)) {
1837 char *dynname = (char *) s1->dynsymtab_section->link->data
1838 + dynsym->st_name;
1839 put_elf_sym(s1->dynsym, offset, dynsym->st_size,
1840 dynsym->st_info, 0,
1841 bss_section->sh_num, dynname);
1842 break;
1843 }
1844 }
1845 }
1846 put_elf_reloc(s1->dynsym, bss_section,
1847 offset, R_COPY, index);
1848 offset += esym->st_size;
1849 bss_section->data_offset = offset;
1850 }
1851 } else {
1852 /* STB_WEAK undefined symbols are accepted */
1853 /* XXX: _fp_hw seems to be part of the ABI, so we ignore it */
1854 if (ELFW(ST_BIND)(sym->st_info) == STB_WEAK ||
1855 !strcmp(name, "_fp_hw")) {
1856 } else {
1857 tcc_error_noabort("undefined symbol '%s'", name);
1858 }
1859 }
1860 } else if (s1->rdynamic && ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
1861 /* if -rdynamic option, then export all non local symbols */
1862 name = (char *) symtab_section->link->data + sym->st_name;
1863 put_elf_sym(s1->dynsym, sym->st_value, sym->st_size, sym->st_info,
1864 0, sym->st_shndx, name);
1865 }
1866 }
1867 }
1868
1869 /* Bind symbols of libraries: export non local symbols of executable that
1870 resolve undefined symbols of shared libraries */
1871 static void bind_libs_dynsyms(TCCState *s1)
1872 {
1873 const char *name;
1874 int sym_index;
1875 ElfW(Sym) *sym, *esym;
1876
1877 /* now look at unresolved dynamic symbols and export
1878 corresponding symbol */
1879 for_each_elem(s1->dynsymtab_section, 1, esym, ElfW(Sym)) {
1880 if (esym->st_shndx == SHN_UNDEF) {
1881 name = (char *) s1->dynsymtab_section->link->data + esym->st_name;
1882 sym_index = find_elf_sym(symtab_section, name);
1883 if (sym_index) {
1884 /* XXX: avoid adding a symbol if already present because of
1885 -rdynamic ? */
1886 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1887 put_elf_sym(s1->dynsym, sym->st_value, sym->st_size,
1888 sym->st_info, 0, sym->st_shndx, name);
1889 } else {
1890 /* weak symbols can stay undefined */
1891 if (ELFW(ST_BIND)(esym->st_info) != STB_WEAK)
1892 tcc_warning("undefined dynamic symbol '%s'", name);
1893 }
1894 }
1895 }
1896 }
1897
1898 /* Export all non local symbols (for shared libraries) */
1899 static void export_global_syms(TCCState *s1)
1900 {
1901 int nb_syms, dynindex, index;
1902 const char *name;
1903 ElfW(Sym) *sym;
1904
1905 nb_syms = symtab_section->data_offset / sizeof(ElfW(Sym));
1906 s1->symtab_to_dynsym = tcc_mallocz(sizeof(int) * nb_syms);
1907 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
1908 if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
1909 name = (char *) symtab_section->link->data + sym->st_name;
1910 dynindex = put_elf_sym(s1->dynsym, sym->st_value, sym->st_size,
1911 sym->st_info, 0, sym->st_shndx, name);
1912 index = sym - (ElfW(Sym) *) symtab_section->data;
1913 s1->symtab_to_dynsym[index] = dynindex;
1914 }
1915 }
1916 }
1917
1918 /* relocate the PLT: compute addresses and offsets in the PLT now that final
1919 address for PLT and GOT are known (see fill_program_header) */
1920 ST_FUNC void relocate_plt(TCCState *s1)
1921 {
1922 uint8_t *p, *p_end;
1923
1924 if (!s1->plt)
1925 return;
1926
1927 p = s1->plt->data;
1928 p_end = p + s1->plt->data_offset;
1929 if (p < p_end) {
1930 #if defined(TCC_TARGET_I386)
1931 put32(p + 2, get32(p + 2) + s1->got->sh_addr);
1932 put32(p + 8, get32(p + 8) + s1->got->sh_addr);
1933 p += 16;
1934 while (p < p_end) {
1935 put32(p + 2, get32(p + 2) + s1->got->sh_addr);
1936 p += 16;
1937 }
1938 #elif defined(TCC_TARGET_X86_64)
1939 int x = s1->got->sh_addr - s1->plt->sh_addr - 6;
1940 put32(p + 2, get32(p + 2) + x);
1941 put32(p + 8, get32(p + 8) + x - 6);
1942 p += 16;
1943 while (p < p_end) {
1944 put32(p + 2, get32(p + 2) + x + s1->plt->data - p);
1945 p += 16;
1946 }
1947 #elif defined(TCC_TARGET_ARM)
1948 int x;
1949 x=s1->got->sh_addr - s1->plt->sh_addr - 12;
1950 p += 16;
1951 while (p < p_end) {
1952 if (get32(p) == 0x46c04778) /* PLT Thumb stub present */
1953 p += 4;
1954 put32(p + 12, x + get32(p + 12) + s1->plt->data - p);
1955 p += 16;
1956 }
1957 #elif defined(TCC_TARGET_ARM64)
1958 uint64_t plt = s1->plt->sh_addr;
1959 uint64_t got = s1->got->sh_addr;
1960 uint64_t off = (got >> 12) - (plt >> 12);
1961 if ((off + ((uint32_t)1 << 20)) >> 21)
1962 tcc_error("Failed relocating PLT (off=0x%lx, got=0x%lx, plt=0x%lx)", off, got, plt);
1963 put32(p, 0xa9bf7bf0); // stp x16,x30,[sp,#-16]!
1964 put32(p + 4, (0x90000010 | // adrp x16,...
1965 (off & 0x1ffffc) << 3 | (off & 3) << 29));
1966 put32(p + 8, (0xf9400211 | // ldr x17,[x16,#...]
1967 (got & 0xff8) << 7));
1968 put32(p + 12, (0x91000210 | // add x16,x16,#...
1969 (got & 0xfff) << 10));
1970 put32(p + 16, 0xd61f0220); // br x17
1971 put32(p + 20, 0xd503201f); // nop
1972 put32(p + 24, 0xd503201f); // nop
1973 put32(p + 28, 0xd503201f); // nop
1974 p += 32;
1975 while (p < p_end) {
1976 uint64_t pc = plt + (p - s1->plt->data);
1977 uint64_t addr = got +
1978 (get32(p) | (uint64_t)get32(p + 4) << 32);
1979 uint32_t off = (addr >> 12) - (pc >> 12);
1980 if ((off + ((uint32_t)1 << 20)) >> 21)
1981 tcc_error("Failed relocating PLT (off=0x%lx, addr=0x%lx, pc=0x%lx)", off, addr, pc);
1982 put32(p, (0x90000010 | // adrp x16,...
1983 (off & 0x1ffffc) << 3 | (off & 3) << 29));
1984 put32(p + 4, (0xf9400211 | // ldr x17,[x16,#...]
1985 (addr & 0xff8) << 7));
1986 put32(p + 8, (0x91000210 | // add x16,x16,#...
1987 (addr & 0xfff) << 10));
1988 put32(p + 12, 0xd61f0220); // br x17
1989 p += 16;
1990 }
1991 #elif defined(TCC_TARGET_C67)
1992 /* XXX: TODO */
1993 #else
1994 #error unsupported CPU
1995 #endif
1996 }
1997 }
1998
1999 /* Allocate strings for section names and decide if an unallocated section
2000 should be output.
2001
2002 NOTE: the strsec section comes last, so its size is also correct ! */
2003 static void alloc_sec_names(TCCState *s1, int file_type, Section *strsec)
2004 {
2005 int i;
2006 Section *s;
2007
2008 /* Allocate strings for section names */
2009 for(i = 1; i < s1->nb_sections; i++) {
2010 s = s1->sections[i];
2011 s->sh_name = put_elf_str(strsec, s->name);
2012 /* when generating a DLL, we include relocations but we may
2013 patch them */
2014 if (file_type == TCC_OUTPUT_DLL &&
2015 s->sh_type == SHT_RELX &&
2016 !(s->sh_flags & SHF_ALLOC)) {
2017 /* gr: avoid bogus relocs for empty (debug) sections */
2018 if (s1->sections[s->sh_info]->sh_flags & SHF_ALLOC)
2019 prepare_dynamic_rel(s1, s);
2020 else if (s1->do_debug)
2021 s->sh_size = s->data_offset;
2022 } else if (s1->do_debug ||
2023 file_type == TCC_OUTPUT_OBJ ||
2024 file_type == TCC_OUTPUT_EXE ||
2025 (s->sh_flags & SHF_ALLOC) ||
2026 i == (s1->nb_sections - 1)) {
2027 /* we output all sections if debug or object file */
2028 s->sh_size = s->data_offset;
2029 }
2030 }
2031 }
2032
2033 /* Info to be copied in dynamic section */
2034 struct dyn_inf {
2035 Section *dynamic;
2036 Section *dynstr;
2037 unsigned long dyn_rel_off;
2038 addr_t rel_addr;
2039 addr_t rel_size;
2040 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2041 addr_t bss_addr;
2042 addr_t bss_size;
2043 #endif
2044 };
2045
2046 /* Assign sections to segments and decide how are sections laid out when loaded
2047 in memory. This function also fills corresponding program headers. */
2048 static int layout_sections(TCCState *s1, ElfW(Phdr) *phdr, int phnum,
2049 Section *interp, Section* strsec,
2050 struct dyn_inf *dyninf, int *sec_order)
2051 {
2052 int i, j, k, file_type, sh_order_index, file_offset;
2053 unsigned long s_align;
2054 long long tmp;
2055 addr_t addr;
2056 ElfW(Phdr) *ph;
2057 Section *s;
2058
2059 file_type = s1->output_type;
2060 sh_order_index = 1;
2061 file_offset = 0;
2062 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF)
2063 file_offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr));
2064 s_align = ELF_PAGE_SIZE;
2065 if (s1->section_align)
2066 s_align = s1->section_align;
2067
2068 if (phnum > 0) {
2069 if (s1->has_text_addr) {
2070 int a_offset, p_offset;
2071 addr = s1->text_addr;
2072 /* we ensure that (addr % ELF_PAGE_SIZE) == file_offset %
2073 ELF_PAGE_SIZE */
2074 a_offset = (int) (addr & (s_align - 1));
2075 p_offset = file_offset & (s_align - 1);
2076 if (a_offset < p_offset)
2077 a_offset += s_align;
2078 file_offset += (a_offset - p_offset);
2079 } else {
2080 if (file_type == TCC_OUTPUT_DLL)
2081 addr = 0;
2082 else
2083 addr = ELF_START_ADDR;
2084 /* compute address after headers */
2085 addr += (file_offset & (s_align - 1));
2086 }
2087
2088 ph = &phdr[0];
2089 /* Leave one program headers for the program interpreter and one for
2090 the program header table itself if needed. These are done later as
2091 they require section layout to be done first. */
2092 if (interp)
2093 ph += 1 + HAVE_PHDR;
2094
2095 /* dynamic relocation table information, for .dynamic section */
2096 dyninf->rel_addr = dyninf->rel_size = 0;
2097 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2098 dyninf->bss_addr = dyninf->bss_size = 0;
2099 #endif
2100
2101 for(j = 0; j < 2; j++) {
2102 ph->p_type = PT_LOAD;
2103 if (j == 0)
2104 ph->p_flags = PF_R | PF_X;
2105 else
2106 ph->p_flags = PF_R | PF_W;
2107 ph->p_align = s_align;
2108
2109 /* Decide the layout of sections loaded in memory. This must
2110 be done before program headers are filled since they contain
2111 info about the layout. We do the following ordering: interp,
2112 symbol tables, relocations, progbits, nobits */
2113 /* XXX: do faster and simpler sorting */
2114 for(k = 0; k < 5; k++) {
2115 for(i = 1; i < s1->nb_sections; i++) {
2116 s = s1->sections[i];
2117 /* compute if section should be included */
2118 if (j == 0) {
2119 if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) !=
2120 SHF_ALLOC)
2121 continue;
2122 } else {
2123 if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) !=
2124 (SHF_ALLOC | SHF_WRITE))
2125 continue;
2126 }
2127 if (s == interp) {
2128 if (k != 0)
2129 continue;
2130 } else if (s->sh_type == SHT_DYNSYM ||
2131 s->sh_type == SHT_STRTAB ||
2132 s->sh_type == SHT_HASH) {
2133 if (k != 1)
2134 continue;
2135 } else if (s->sh_type == SHT_RELX) {
2136 if (k != 2)
2137 continue;
2138 } else if (s->sh_type == SHT_NOBITS) {
2139 if (k != 4)
2140 continue;
2141 } else {
2142 if (k != 3)
2143 continue;
2144 }
2145 sec_order[sh_order_index++] = i;
2146
2147 /* section matches: we align it and add its size */
2148 tmp = addr;
2149 addr = (addr + s->sh_addralign - 1) &
2150 ~(s->sh_addralign - 1);
2151 file_offset += (int) ( addr - tmp );
2152 s->sh_offset = file_offset;
2153 s->sh_addr = addr;
2154
2155 /* update program header infos */
2156 if (ph->p_offset == 0) {
2157 ph->p_offset = file_offset;
2158 ph->p_vaddr = addr;
2159 ph->p_paddr = ph->p_vaddr;
2160 }
2161 /* update dynamic relocation infos */
2162 if (s->sh_type == SHT_RELX) {
2163 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2164 if (!strcmp(strsec->data + s->sh_name, ".rel.got")) {
2165 dyninf->rel_addr = addr;
2166 dyninf->rel_size += s->sh_size; /* XXX only first rel. */
2167 }
2168 if (!strcmp(strsec->data + s->sh_name, ".rel.bss")) {
2169 dyninf->bss_addr = addr;
2170 dyninf->bss_size = s->sh_size; /* XXX only first rel. */
2171 }
2172 #else
2173 if (dyninf->rel_size == 0)
2174 dyninf->rel_addr = addr;
2175 dyninf->rel_size += s->sh_size;
2176 #endif
2177 }
2178 addr += s->sh_size;
2179 if (s->sh_type != SHT_NOBITS)
2180 file_offset += s->sh_size;
2181 }
2182 }
2183 if (j == 0) {
2184 /* Make the first PT_LOAD segment include the program
2185 headers itself (and the ELF header as well), it'll
2186 come out with same memory use but will make various
2187 tools like binutils strip work better. */
2188 ph->p_offset &= ~(ph->p_align - 1);
2189 ph->p_vaddr &= ~(ph->p_align - 1);
2190 ph->p_paddr &= ~(ph->p_align - 1);
2191 }
2192 ph->p_filesz = file_offset - ph->p_offset;
2193 ph->p_memsz = addr - ph->p_vaddr;
2194 ph++;
2195 if (j == 0) {
2196 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF) {
2197 /* if in the middle of a page, we duplicate the page in
2198 memory so that one copy is RX and the other is RW */
2199 if ((addr & (s_align - 1)) != 0)
2200 addr += s_align;
2201 } else {
2202 addr = (addr + s_align - 1) & ~(s_align - 1);
2203 file_offset = (file_offset + s_align - 1) & ~(s_align - 1);
2204 }
2205 }
2206 }
2207 }
2208
2209 /* all other sections come after */
2210 for(i = 1; i < s1->nb_sections; i++) {
2211 s = s1->sections[i];
2212 if (phnum > 0 && (s->sh_flags & SHF_ALLOC))
2213 continue;
2214 sec_order[sh_order_index++] = i;
2215
2216 file_offset = (file_offset + s->sh_addralign - 1) &
2217 ~(s->sh_addralign - 1);
2218 s->sh_offset = file_offset;
2219 if (s->sh_type != SHT_NOBITS)
2220 file_offset += s->sh_size;
2221 }
2222
2223 return file_offset;
2224 }
2225
2226 static void fill_unloadable_phdr(ElfW(Phdr) *phdr, int phnum, Section *interp,
2227 Section *dynamic)
2228 {
2229 ElfW(Phdr) *ph;
2230
2231 /* if interpreter, then add corresponding program header */
2232 if (interp) {
2233 ph = &phdr[0];
2234
2235 if (HAVE_PHDR)
2236 {
2237 int len = phnum * sizeof(ElfW(Phdr));
2238
2239 ph->p_type = PT_PHDR;
2240 ph->p_offset = sizeof(ElfW(Ehdr));
2241 ph->p_vaddr = interp->sh_addr - len;
2242 ph->p_paddr = ph->p_vaddr;
2243 ph->p_filesz = ph->p_memsz = len;
2244 ph->p_flags = PF_R | PF_X;
2245 ph->p_align = 4; /* interp->sh_addralign; */
2246 ph++;
2247 }
2248
2249 ph->p_type = PT_INTERP;
2250 ph->p_offset = interp->sh_offset;
2251 ph->p_vaddr = interp->sh_addr;
2252 ph->p_paddr = ph->p_vaddr;
2253 ph->p_filesz = interp->sh_size;
2254 ph->p_memsz = interp->sh_size;
2255 ph->p_flags = PF_R;
2256 ph->p_align = interp->sh_addralign;
2257 }
2258
2259 /* if dynamic section, then add corresponding program header */
2260 if (dynamic) {
2261 ph = &phdr[phnum - 1];
2262
2263 ph->p_type = PT_DYNAMIC;
2264 ph->p_offset = dynamic->sh_offset;
2265 ph->p_vaddr = dynamic->sh_addr;
2266 ph->p_paddr = ph->p_vaddr;
2267 ph->p_filesz = dynamic->sh_size;
2268 ph->p_memsz = dynamic->sh_size;
2269 ph->p_flags = PF_R | PF_W;
2270 ph->p_align = dynamic->sh_addralign;
2271 }
2272 }
2273
2274 /* Fill the dynamic section with tags describing the address and size of
2275 sections */
2276 static void fill_dynamic(TCCState *s1, struct dyn_inf *dyninf)
2277 {
2278 Section *dynamic;
2279
2280 dynamic = dyninf->dynamic;
2281
2282 /* put dynamic section entries */
2283 dynamic->data_offset = dyninf->dyn_rel_off;
2284 put_dt(dynamic, DT_HASH, s1->dynsym->hash->sh_addr);
2285 put_dt(dynamic, DT_STRTAB, dyninf->dynstr->sh_addr);
2286 put_dt(dynamic, DT_SYMTAB, s1->dynsym->sh_addr);
2287 put_dt(dynamic, DT_STRSZ, dyninf->dynstr->data_offset);
2288 put_dt(dynamic, DT_SYMENT, sizeof(ElfW(Sym)));
2289 #if defined(TCC_TARGET_ARM64) || defined(TCC_TARGET_X86_64)
2290 put_dt(dynamic, DT_RELA, dyninf->rel_addr);
2291 put_dt(dynamic, DT_RELASZ, dyninf->rel_size);
2292 put_dt(dynamic, DT_RELAENT, sizeof(ElfW_Rel));
2293 #else
2294 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2295 put_dt(dynamic, DT_PLTGOT, s1->got->sh_addr);
2296 put_dt(dynamic, DT_PLTRELSZ, dyninf->rel_size);
2297 put_dt(dynamic, DT_JMPREL, dyninf->rel_addr);
2298 put_dt(dynamic, DT_PLTREL, DT_REL);
2299 put_dt(dynamic, DT_REL, dyninf->bss_addr);
2300 put_dt(dynamic, DT_RELSZ, dyninf->bss_size);
2301 #else
2302 put_dt(dynamic, DT_REL, dyninf->rel_addr);
2303 put_dt(dynamic, DT_RELSZ, dyninf->rel_size);
2304 put_dt(dynamic, DT_RELENT, sizeof(ElfW_Rel));
2305 #endif
2306 #endif
2307 if (s1->do_debug)
2308 put_dt(dynamic, DT_DEBUG, 0);
2309 put_dt(dynamic, DT_NULL, 0);
2310 }
2311
2312 /* Relocate remaining sections and symbols (that is those not related to
2313 dynamic linking) */
2314 static int final_sections_reloc(TCCState *s1)
2315 {
2316 int i;
2317 Section *s;
2318
2319 relocate_syms(s1, 0);
2320
2321 if (s1->nb_errors != 0)
2322 return -1;
2323
2324 /* relocate sections */
2325 /* XXX: ignore sections with allocated relocations ? */
2326 for(i = 1; i < s1->nb_sections; i++) {
2327 s = s1->sections[i];
2328 #ifdef TCC_TARGET_I386
2329 if (s->reloc && s != s1->got && (s->sh_flags & SHF_ALLOC)) //gr
2330 /* On X86 gdb 7.3 works in any case but gdb 6.6 will crash if SHF_ALLOC
2331 checking is removed */
2332 #else
2333 if (s->reloc && s != s1->got)
2334 /* On X86_64 gdb 7.3 will crash if SHF_ALLOC checking is present */
2335 #endif
2336 relocate_section(s1, s);
2337 }
2338
2339 /* relocate relocation entries if the relocation tables are
2340 allocated in the executable */
2341 for(i = 1; i < s1->nb_sections; i++) {
2342 s = s1->sections[i];
2343 if ((s->sh_flags & SHF_ALLOC) &&
2344 s->sh_type == SHT_RELX) {
2345 relocate_rel(s1, s);
2346 }
2347 }
2348 return 0;
2349 }
2350
2351 /* Create an ELF file on disk.
2352 This function handle ELF specific layout requirements */
2353 static void tcc_output_elf(TCCState *s1, FILE *f, int phnum, ElfW(Phdr) *phdr,
2354 int file_offset, int *sec_order)
2355 {
2356 int i, shnum, offset, size, file_type;
2357 Section *s;
2358 ElfW(Ehdr) ehdr;
2359 ElfW(Shdr) shdr, *sh;
2360
2361 file_type = s1->output_type;
2362 shnum = s1->nb_sections;
2363
2364 memset(&ehdr, 0, sizeof(ehdr));
2365
2366 if (phnum > 0) {
2367 ehdr.e_phentsize = sizeof(ElfW(Phdr));
2368 ehdr.e_phnum = phnum;
2369 ehdr.e_phoff = sizeof(ElfW(Ehdr));
2370 }
2371
2372 /* align to 4 */
2373 file_offset = (file_offset + 3) & -4;
2374
2375 /* fill header */
2376 ehdr.e_ident[0] = ELFMAG0;
2377 ehdr.e_ident[1] = ELFMAG1;
2378 ehdr.e_ident[2] = ELFMAG2;
2379 ehdr.e_ident[3] = ELFMAG3;
2380 ehdr.e_ident[4] = ELFCLASSW;
2381 ehdr.e_ident[5] = ELFDATA2LSB;
2382 ehdr.e_ident[6] = EV_CURRENT;
2383 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2384 ehdr.e_ident[EI_OSABI] = ELFOSABI_FREEBSD;
2385 #endif
2386 #ifdef TCC_TARGET_ARM
2387 #ifdef TCC_ARM_EABI
2388 ehdr.e_ident[EI_OSABI] = 0;
2389 ehdr.e_flags = EF_ARM_EABI_VER4;
2390 if (file_type == TCC_OUTPUT_EXE || file_type == TCC_OUTPUT_DLL)
2391 ehdr.e_flags |= EF_ARM_HASENTRY;
2392 if (s1->float_abi == ARM_HARD_FLOAT)
2393 ehdr.e_flags |= EF_ARM_VFP_FLOAT;
2394 else
2395 ehdr.e_flags |= EF_ARM_SOFT_FLOAT;
2396 #else
2397 ehdr.e_ident[EI_OSABI] = ELFOSABI_ARM;
2398 #endif
2399 #endif
2400 switch(file_type) {
2401 default:
2402 case TCC_OUTPUT_EXE:
2403 ehdr.e_type = ET_EXEC;
2404 ehdr.e_entry = get_elf_sym_addr(s1, "_start", 1);
2405 break;
2406 case TCC_OUTPUT_DLL:
2407 ehdr.e_type = ET_DYN;
2408 ehdr.e_entry = text_section->sh_addr; /* XXX: is it correct ? */
2409 break;
2410 case TCC_OUTPUT_OBJ:
2411 ehdr.e_type = ET_REL;
2412 break;
2413 }
2414 ehdr.e_machine = EM_TCC_TARGET;
2415 ehdr.e_version = EV_CURRENT;
2416 ehdr.e_shoff = file_offset;
2417 ehdr.e_ehsize = sizeof(ElfW(Ehdr));
2418 ehdr.e_shentsize = sizeof(ElfW(Shdr));
2419 ehdr.e_shnum = shnum;
2420 ehdr.e_shstrndx = shnum - 1;
2421
2422 fwrite(&ehdr, 1, sizeof(ElfW(Ehdr)), f);
2423 fwrite(phdr, 1, phnum * sizeof(ElfW(Phdr)), f);
2424 offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr));
2425
2426 sort_syms(s1, symtab_section);
2427 for(i = 1; i < s1->nb_sections; i++) {
2428 s = s1->sections[sec_order[i]];
2429 if (s->sh_type != SHT_NOBITS) {
2430 if (s->sh_type == SHT_DYNSYM)
2431 patch_dynsym_undef(s1, s);
2432 while (offset < s->sh_offset) {
2433 fputc(0, f);
2434 offset++;
2435 }
2436 size = s->sh_size;
2437 fwrite(s->data, 1, size, f);
2438 offset += size;
2439 }
2440 }
2441
2442 /* output section headers */
2443 while (offset < ehdr.e_shoff) {
2444 fputc(0, f);
2445 offset++;
2446 }
2447
2448 for(i = 0; i < s1->nb_sections; i++) {
2449 sh = &shdr;
2450 memset(sh, 0, sizeof(ElfW(Shdr)));
2451 s = s1->sections[i];
2452 if (s) {
2453 sh->sh_name = s->sh_name;
2454 sh->sh_type = s->sh_type;
2455 sh->sh_flags = s->sh_flags;
2456 sh->sh_entsize = s->sh_entsize;
2457 sh->sh_info = s->sh_info;
2458 if (s->link)
2459 sh->sh_link = s->link->sh_num;
2460 sh->sh_addralign = s->sh_addralign;
2461 sh->sh_addr = s->sh_addr;
2462 sh->sh_offset = s->sh_offset;
2463 sh->sh_size = s->sh_size;
2464 }
2465 fwrite(sh, 1, sizeof(ElfW(Shdr)), f);
2466 }
2467 }
2468
2469 /* Write an elf, coff or "binary" file */
2470 static int tcc_write_elf_file(TCCState *s1, const char *filename, int phnum,
2471 ElfW(Phdr) *phdr, int file_offset, int *sec_order)
2472 {
2473 int fd, mode, file_type;
2474 FILE *f;
2475
2476 file_type = s1->output_type;
2477 if (file_type == TCC_OUTPUT_OBJ)
2478 mode = 0666;
2479 else
2480 mode = 0777;
2481 unlink(filename);
2482 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, mode);
2483 if (fd < 0) {
2484 tcc_error_noabort("could not write '%s'", filename);
2485 return -1;
2486 }
2487 f = fdopen(fd, "wb");
2488 if (s1->verbose)
2489 printf("<- %s\n", filename);
2490
2491 #ifdef TCC_TARGET_COFF
2492 if (s1->output_format == TCC_OUTPUT_FORMAT_COFF)
2493 tcc_output_coff(s1, f);
2494 else
2495 #endif
2496 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF)
2497 tcc_output_elf(s1, f, phnum, phdr, file_offset, sec_order);
2498 else
2499 tcc_output_binary(s1, f, sec_order);
2500 fclose(f);
2501
2502 return 0;
2503 }
2504
2505 /* Output an elf, coff or binary file */
2506 /* XXX: suppress unneeded sections */
2507 static int elf_output_file(TCCState *s1, const char *filename)
2508 {
2509 int i, ret, phnum, shnum, file_type, file_offset, *sec_order;
2510 struct dyn_inf dyninf;
2511 ElfW(Phdr) *phdr;
2512 ElfW(Sym) *sym;
2513 Section *strsec, *interp, *dynamic, *dynstr;
2514
2515 file_type = s1->output_type;
2516 s1->nb_errors = 0;
2517
2518 /* if linking, also link in runtime libraries (libc, libgcc, etc.) */
2519 if (file_type != TCC_OUTPUT_OBJ) {
2520 tcc_add_runtime(s1);
2521 }
2522
2523 phdr = NULL;
2524 sec_order = NULL;
2525 interp = dynamic = dynstr = NULL; /* avoid warning */
2526 dyninf.dyn_rel_off = 0; /* avoid warning */
2527
2528 if (file_type != TCC_OUTPUT_OBJ) {
2529 relocate_common_syms();
2530
2531 tcc_add_linker_symbols(s1);
2532
2533 if (!s1->static_link) {
2534 if (file_type == TCC_OUTPUT_EXE) {
2535 char *ptr;
2536 /* allow override the dynamic loader */
2537 const char *elfint = getenv("LD_SO");
2538 if (elfint == NULL)
2539 elfint = DEFAULT_ELFINTERP(s1);
2540 /* add interpreter section only if executable */
2541 interp = new_section(s1, ".interp", SHT_PROGBITS, SHF_ALLOC);
2542 interp->sh_addralign = 1;
2543 ptr = section_ptr_add(interp, 1 + strlen(elfint));
2544 strcpy(ptr, elfint);
2545 }
2546
2547 /* add dynamic symbol table */
2548 s1->dynsym = new_symtab(s1, ".dynsym", SHT_DYNSYM, SHF_ALLOC,
2549 ".dynstr",
2550 ".hash", SHF_ALLOC);
2551 dynstr = s1->dynsym->link;
2552
2553 /* add dynamic section */
2554 dynamic = new_section(s1, ".dynamic", SHT_DYNAMIC,
2555 SHF_ALLOC | SHF_WRITE);
2556 dynamic->link = dynstr;
2557 dynamic->sh_entsize = sizeof(ElfW(Dyn));
2558
2559 build_got(s1);
2560
2561 if (file_type == TCC_OUTPUT_EXE) {
2562 bind_exe_dynsyms(s1);
2563
2564 if (s1->nb_errors) {
2565 ret = -1;
2566 goto the_end;
2567 }
2568
2569 bind_libs_dynsyms(s1);
2570 } else /* shared library case: simply export all global symbols */
2571 export_global_syms(s1);
2572
2573 build_got_entries(s1);
2574
2575 /* add a list of needed dlls */
2576 for(i = 0; i < s1->nb_loaded_dlls; i++) {
2577 DLLReference *dllref = s1->loaded_dlls[i];
2578 if (dllref->level == 0)
2579 put_dt(dynamic, DT_NEEDED, put_elf_str(dynstr, dllref->name));
2580 }
2581
2582 if (s1->rpath)
2583 put_dt(dynamic, DT_RPATH, put_elf_str(dynstr, s1->rpath));
2584
2585 /* XXX: currently, since we do not handle PIC code, we
2586 must relocate the readonly segments */
2587 if (file_type == TCC_OUTPUT_DLL) {
2588 if (s1->soname)
2589 put_dt(dynamic, DT_SONAME, put_elf_str(dynstr, s1->soname));
2590 put_dt(dynamic, DT_TEXTREL, 0);
2591 }
2592
2593 if (s1->symbolic)
2594 put_dt(dynamic, DT_SYMBOLIC, 0);
2595
2596 /* add necessary space for other entries */
2597 dyninf.dyn_rel_off = dynamic->data_offset;
2598 dynamic->data_offset += sizeof(ElfW(Dyn)) * EXTRA_RELITEMS;
2599 } else {
2600 /* still need to build got entries in case of static link */
2601 build_got_entries(s1);
2602 }
2603 }
2604
2605 /* we add a section for symbols */
2606 strsec = new_section(s1, ".shstrtab", SHT_STRTAB, 0);
2607 put_elf_str(strsec, "");
2608
2609 /* compute number of sections */
2610 shnum = s1->nb_sections;
2611
2612 /* this array is used to reorder sections in the output file */
2613 sec_order = tcc_malloc(sizeof(int) * shnum);
2614 sec_order[0] = 0;
2615
2616 /* compute number of program headers */
2617 switch(file_type) {
2618 default:
2619 case TCC_OUTPUT_OBJ:
2620 phnum = 0;
2621 break;
2622 case TCC_OUTPUT_EXE:
2623 if (!s1->static_link)
2624 phnum = 4 + HAVE_PHDR;
2625 else
2626 phnum = 2;
2627 break;
2628 case TCC_OUTPUT_DLL:
2629 phnum = 3;
2630 break;
2631 }
2632
2633 /* Allocate strings for section names */
2634 alloc_sec_names(s1, file_type, strsec);
2635
2636 /* allocate program segment headers */
2637 phdr = tcc_mallocz(phnum * sizeof(ElfW(Phdr)));
2638
2639 /* compute section to program header mapping */
2640 file_offset = layout_sections(s1, phdr, phnum, interp, strsec, &dyninf,
2641 sec_order);
2642
2643 /* Fill remaining program header and finalize relocation related to dynamic
2644 linking. */
2645 if (phnum > 0) {
2646 fill_unloadable_phdr(phdr, phnum, interp, dynamic);
2647 if (dynamic) {
2648 dyninf.dynamic = dynamic;
2649 dyninf.dynstr = dynstr;
2650
2651 fill_dynamic(s1, &dyninf);
2652
2653 /* put in GOT the dynamic section address and relocate PLT */
2654 put32(s1->got->data, dynamic->sh_addr);
2655 if (file_type == TCC_OUTPUT_EXE
2656 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
2657 || file_type == TCC_OUTPUT_DLL
2658 #endif
2659 )
2660 relocate_plt(s1);
2661
2662 /* relocate symbols in .dynsym now that final addresses are known */
2663 for_each_elem(s1->dynsym, 1, sym, ElfW(Sym)) {
2664 if (sym->st_shndx == SHN_UNDEF) {
2665 /* relocate to PLT if symbol corresponds to a PLT entry,
2666 but not if it's a weak symbol */
2667 if (ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
2668 sym->st_value = 0;
2669 else if (sym->st_value)
2670 sym->st_value += s1->plt->sh_addr;
2671 } else if (sym->st_shndx < SHN_LORESERVE) {
2672 /* do symbol relocation */
2673 sym->st_value += s1->sections[sym->st_shndx]->sh_addr;
2674 }
2675 }
2676 }
2677 }
2678
2679 /* if building executable or DLL, then relocate each section
2680 except the GOT which is already relocated */
2681 if (file_type != TCC_OUTPUT_OBJ) {
2682 ret = final_sections_reloc(s1);
2683 if (ret)
2684 goto the_end;
2685 }
2686
2687 /* Perform relocation to GOT or PLT entries */
2688 if (file_type == TCC_OUTPUT_EXE && s1->static_link)
2689 fill_got(s1);
2690
2691 /* Create the ELF file with name 'filename' */
2692 ret = tcc_write_elf_file(s1, filename, phnum, phdr, file_offset, sec_order);
2693 if (s1->do_strip) {
2694 const char *strip = "sstrip "; // super strip utility from ELFkickers
2695 const char *null = " 2> /dev/null";
2696 int len = strlen(strip) + strlen(filename) + strlen(null) + 1;
2697 {
2698 int rc;
2699 char buf[len];
2700 sprintf(buf, "%s%s%s", strip, filename, null);
2701 rc = system(buf);
2702 if (rc) {
2703 system(buf+1); // call a strip utility from binutils
2704 }
2705 }
2706 }
2707 the_end:
2708 tcc_free(s1->symtab_to_dynsym);
2709 tcc_free(sec_order);
2710 tcc_free(phdr);
2711 tcc_free(s1->sym_attrs);
2712 s1->sym_attrs = NULL;
2713 return ret;
2714 }
2715
2716 LIBTCCAPI int tcc_output_file(TCCState *s, const char *filename)
2717 {
2718 int ret;
2719 #ifdef TCC_TARGET_PE
2720 if (s->output_type != TCC_OUTPUT_OBJ) {
2721 ret = pe_output_file(s, filename);
2722 } else
2723 #endif
2724 ret = elf_output_file(s, filename);
2725 return ret;
2726 }
2727
2728 static void *load_data(int fd, unsigned long file_offset, unsigned long size)
2729 {
2730 void *data;
2731
2732 data = tcc_malloc(size);
2733 lseek(fd, file_offset, SEEK_SET);
2734 read(fd, data, size);
2735 return data;
2736 }
2737
2738 typedef struct SectionMergeInfo {
2739 Section *s; /* corresponding existing section */
2740 unsigned long offset; /* offset of the new section in the existing section */
2741 uint8_t new_section; /* true if section 's' was added */
2742 uint8_t link_once; /* true if link once section */
2743 } SectionMergeInfo;
2744
2745 /* load an object file and merge it with current files */
2746 /* XXX: handle correctly stab (debug) info */
2747 ST_FUNC int tcc_load_object_file(TCCState *s1,
2748 int fd, unsigned long file_offset)
2749 {
2750 ElfW(Ehdr) ehdr;
2751 ElfW(Shdr) *shdr, *sh;
2752 int size, i, j, offset, offseti, nb_syms, sym_index, ret;
2753 unsigned char *strsec, *strtab;
2754 int *old_to_new_syms;
2755 char *sh_name, *name;
2756 SectionMergeInfo *sm_table, *sm;
2757 ElfW(Sym) *sym, *symtab;
2758 ElfW_Rel *rel;
2759 Section *s;
2760
2761 int stab_index;
2762 int stabstr_index;
2763
2764 stab_index = stabstr_index = 0;
2765
2766 if (read(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr))
2767 goto fail1;
2768 if (ehdr.e_ident[0] != ELFMAG0 ||
2769 ehdr.e_ident[1] != ELFMAG1 ||
2770 ehdr.e_ident[2] != ELFMAG2 ||
2771 ehdr.e_ident[3] != ELFMAG3)
2772 goto fail1;
2773 /* test if object file */
2774 if (ehdr.e_type != ET_REL)
2775 goto fail1;
2776 /* test CPU specific stuff */
2777 if (ehdr.e_ident[5] != ELFDATA2LSB ||
2778 ehdr.e_machine != EM_TCC_TARGET) {
2779 fail1:
2780 tcc_error_noabort("invalid object file");
2781 return -1;
2782 }
2783 /* read sections */
2784 shdr = load_data(fd, file_offset + ehdr.e_shoff,
2785 sizeof(ElfW(Shdr)) * ehdr.e_shnum);
2786 sm_table = tcc_mallocz(sizeof(SectionMergeInfo) * ehdr.e_shnum);
2787
2788 /* load section names */
2789 sh = &shdr[ehdr.e_shstrndx];
2790 strsec = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2791
2792 /* load symtab and strtab */
2793 old_to_new_syms = NULL;
2794 symtab = NULL;
2795 strtab = NULL;
2796 nb_syms = 0;
2797 for(i = 1; i < ehdr.e_shnum; i++) {
2798 sh = &shdr[i];
2799 if (sh->sh_type == SHT_SYMTAB) {
2800 if (symtab) {
2801 tcc_error_noabort("object must contain only one symtab");
2802 fail:
2803 ret = -1;
2804 goto the_end;
2805 }
2806 nb_syms = sh->sh_size / sizeof(ElfW(Sym));
2807 symtab = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2808 sm_table[i].s = symtab_section;
2809
2810 /* now load strtab */
2811 sh = &shdr[sh->sh_link];
2812 strtab = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2813 }
2814 }
2815
2816 /* now examine each section and try to merge its content with the
2817 ones in memory */
2818 for(i = 1; i < ehdr.e_shnum; i++) {
2819 /* no need to examine section name strtab */
2820 if (i == ehdr.e_shstrndx)
2821 continue;
2822 sh = &shdr[i];
2823 sh_name = (char *) strsec + sh->sh_name;
2824 /* ignore sections types we do not handle */
2825 if (sh->sh_type != SHT_PROGBITS &&
2826 sh->sh_type != SHT_RELX &&
2827 #ifdef TCC_ARM_EABI
2828 sh->sh_type != SHT_ARM_EXIDX &&
2829 #endif
2830 sh->sh_type != SHT_NOBITS &&
2831 sh->sh_type != SHT_PREINIT_ARRAY &&
2832 sh->sh_type != SHT_INIT_ARRAY &&
2833 sh->sh_type != SHT_FINI_ARRAY &&
2834 strcmp(sh_name, ".stabstr")
2835 )
2836 continue;
2837 if (sh->sh_addralign < 1)
2838 sh->sh_addralign = 1;
2839 /* find corresponding section, if any */
2840 for(j = 1; j < s1->nb_sections;j++) {
2841 s = s1->sections[j];
2842 if (!strcmp(s->name, sh_name)) {
2843 if (!strncmp(sh_name, ".gnu.linkonce",
2844 sizeof(".gnu.linkonce") - 1)) {
2845 /* if a 'linkonce' section is already present, we
2846 do not add it again. It is a little tricky as
2847 symbols can still be defined in
2848 it. */
2849 sm_table[i].link_once = 1;
2850 goto next;
2851 } else {
2852 goto found;
2853 }
2854 }
2855 }
2856 /* not found: create new section */
2857 s = new_section(s1, sh_name, sh->sh_type, sh->sh_flags);
2858 /* take as much info as possible from the section. sh_link and
2859 sh_info will be updated later */
2860 s->sh_addralign = sh->sh_addralign;
2861 s->sh_entsize = sh->sh_entsize;
2862 sm_table[i].new_section = 1;
2863 found:
2864 if (sh->sh_type != s->sh_type) {
2865 tcc_error_noabort("invalid section type");
2866 goto fail;
2867 }
2868
2869 /* align start of section */
2870 offset = s->data_offset;
2871
2872 if (0 == strcmp(sh_name, ".stab")) {
2873 stab_index = i;
2874 goto no_align;
2875 }
2876 if (0 == strcmp(sh_name, ".stabstr")) {
2877 stabstr_index = i;
2878 goto no_align;
2879 }
2880
2881 size = sh->sh_addralign - 1;
2882 offset = (offset + size) & ~size;
2883 if (sh->sh_addralign > s->sh_addralign)
2884 s->sh_addralign = sh->sh_addralign;
2885 s->data_offset = offset;
2886 no_align:
2887 sm_table[i].offset = offset;
2888 sm_table[i].s = s;
2889 /* concatenate sections */
2890 size = sh->sh_size;
2891 if (sh->sh_type != SHT_NOBITS) {
2892 unsigned char *ptr;
2893 lseek(fd, file_offset + sh->sh_offset, SEEK_SET);
2894 ptr = section_ptr_add(s, size);
2895 read(fd, ptr, size);
2896 } else {
2897 s->data_offset += size;
2898 }
2899 next: ;
2900 }
2901
2902 /* gr relocate stab strings */
2903 if (stab_index && stabstr_index) {
2904 Stab_Sym *a, *b;
2905 unsigned o;
2906 s = sm_table[stab_index].s;
2907 a = (Stab_Sym *)(s->data + sm_table[stab_index].offset);
2908 b = (Stab_Sym *)(s->data + s->data_offset);
2909 o = sm_table[stabstr_index].offset;
2910 while (a < b)
2911 a->n_strx += o, a++;
2912 }
2913
2914 /* second short pass to update sh_link and sh_info fields of new
2915 sections */
2916 for(i = 1; i < ehdr.e_shnum; i++) {
2917 s = sm_table[i].s;
2918 if (!s || !sm_table[i].new_section)
2919 continue;
2920 sh = &shdr[i];
2921 if (sh->sh_link > 0)
2922 s->link = sm_table[sh->sh_link].s;
2923 if (sh->sh_type == SHT_RELX) {
2924 s->sh_info = sm_table[sh->sh_info].s->sh_num;
2925 /* update backward link */
2926 s1->sections[s->sh_info]->reloc = s;
2927 }
2928 }
2929 sm = sm_table;
2930
2931 /* resolve symbols */
2932 old_to_new_syms = tcc_mallocz(nb_syms * sizeof(int));
2933
2934 sym = symtab + 1;
2935 for(i = 1; i < nb_syms; i++, sym++) {
2936 if (sym->st_shndx != SHN_UNDEF &&
2937 sym->st_shndx < SHN_LORESERVE) {
2938 sm = &sm_table[sym->st_shndx];
2939 if (sm->link_once) {
2940 /* if a symbol is in a link once section, we use the
2941 already defined symbol. It is very important to get
2942 correct relocations */
2943 if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
2944 name = (char *) strtab + sym->st_name;
2945 sym_index = find_elf_sym(symtab_section, name);
2946 if (sym_index)
2947 old_to_new_syms[i] = sym_index;
2948 }
2949 continue;
2950 }
2951 /* if no corresponding section added, no need to add symbol */
2952 if (!sm->s)
2953 continue;
2954 /* convert section number */
2955 sym->st_shndx = sm->s->sh_num;
2956 /* offset value */
2957 sym->st_value += sm->offset;
2958 }
2959 /* add symbol */
2960 name = (char *) strtab + sym->st_name;
2961 sym_index = add_elf_sym(symtab_section, sym->st_value, sym->st_size,
2962 sym->st_info, sym->st_other,
2963 sym->st_shndx, name);
2964 old_to_new_syms[i] = sym_index;
2965 }
2966
2967 /* third pass to patch relocation entries */
2968 for(i = 1; i < ehdr.e_shnum; i++) {
2969 s = sm_table[i].s;
2970 if (!s)
2971 continue;
2972 sh = &shdr[i];
2973 offset = sm_table[i].offset;
2974 switch(s->sh_type) {
2975 case SHT_RELX:
2976 /* take relocation offset information */
2977 offseti = sm_table[sh->sh_info].offset;
2978 for_each_elem(s, (offset / sizeof(*rel)), rel, ElfW_Rel) {
2979 int type;
2980 unsigned sym_index;
2981 /* convert symbol index */
2982 type = ELFW(R_TYPE)(rel->r_info);
2983 sym_index = ELFW(R_SYM)(rel->r_info);
2984 /* NOTE: only one symtab assumed */
2985 if (sym_index >= nb_syms)
2986 goto invalid_reloc;
2987 sym_index = old_to_new_syms[sym_index];
2988 /* ignore link_once in rel section. */
2989 if (!sym_index && !sm->link_once
2990 #ifdef TCC_TARGET_ARM
2991 && type != R_ARM_V4BX
2992 #endif
2993 ) {
2994 invalid_reloc:
2995 tcc_error_noabort("Invalid relocation entry [%2d] '%s' @ %.8x",
2996 i, strsec + sh->sh_name, rel->r_offset);
2997 goto fail;
2998 }
2999 rel->r_info = ELFW(R_INFO)(sym_index, type);
3000 /* offset the relocation offset */
3001 rel->r_offset += offseti;
3002 #ifdef TCC_TARGET_ARM
3003 /* Jumps and branches from a Thumb code to a PLT entry need
3004 special handling since PLT entries are ARM code.
3005 Unconditional bl instructions referencing PLT entries are
3006 handled by converting these instructions into blx
3007 instructions. Other case of instructions referencing a PLT
3008 entry require to add a Thumb stub before the PLT entry to
3009 switch to ARM mode. We set bit plt_thumb_stub of the
3010 attribute of a symbol to indicate such a case. */
3011 if (type == R_ARM_THM_JUMP24)
3012 alloc_sym_attr(s1, sym_index)->plt_thumb_stub = 1;
3013 #endif
3014 }
3015 break;
3016 default:
3017 break;
3018 }
3019 }
3020
3021 ret = 0;
3022 the_end:
3023 tcc_free(symtab);
3024 tcc_free(strtab);
3025 tcc_free(old_to_new_syms);
3026 tcc_free(sm_table);
3027 tcc_free(strsec);
3028 tcc_free(shdr);
3029 return ret;
3030 }
3031
3032 typedef struct ArchiveHeader {
3033 char ar_name[16]; /* name of this member */
3034 char ar_date[12]; /* file mtime */
3035 char ar_uid[6]; /* owner uid; printed as decimal */
3036 char ar_gid[6]; /* owner gid; printed as decimal */
3037 char ar_mode[8]; /* file mode, printed as octal */
3038 char ar_size[10]; /* file size, printed as decimal */
3039 char ar_fmag[2]; /* should contain ARFMAG */
3040 } ArchiveHeader;
3041
3042 static int get_be32(const uint8_t *b)
3043 {
3044 return b[3] | (b[2] << 8) | (b[1] << 16) | (b[0] << 24);
3045 }
3046
3047 /* load only the objects which resolve undefined symbols */
3048 static int tcc_load_alacarte(TCCState *s1, int fd, int size)
3049 {
3050 int i, bound, nsyms, sym_index, off, ret;
3051 uint8_t *data;
3052 const char *ar_names, *p;
3053 const uint8_t *ar_index;
3054 ElfW(Sym) *sym;
3055
3056 data = tcc_malloc(size);
3057 if (read(fd, data, size) != size)
3058 goto fail;
3059 nsyms = get_be32(data);
3060 ar_index = data + 4;
3061 ar_names = (char *) ar_index + nsyms * 4;
3062
3063 do {
3064 bound = 0;
3065 for(p = ar_names, i = 0; i < nsyms; i++, p += strlen(p)+1) {
3066 sym_index = find_elf_sym(symtab_section, p);
3067 if(sym_index) {
3068 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
3069 if(sym->st_shndx == SHN_UNDEF) {
3070 off = get_be32(ar_index + i * 4) + sizeof(ArchiveHeader);
3071 ++bound;
3072 lseek(fd, off, SEEK_SET);
3073 if(tcc_load_object_file(s1, fd, off) < 0) {
3074 fail:
3075 ret = -1;
3076 goto the_end;
3077 }
3078 }
3079 }
3080 }
3081 } while(bound);
3082 ret = 0;
3083 the_end:
3084 tcc_free(data);
3085 return ret;
3086 }
3087
3088 /* load a '.a' file */
3089 ST_FUNC int tcc_load_archive(TCCState *s1, int fd)
3090 {
3091 ArchiveHeader hdr;
3092 char ar_size[11];
3093 char ar_name[17];
3094 char magic[8];
3095 int size, len, i;
3096 unsigned long file_offset;
3097
3098 /* skip magic which was already checked */
3099 read(fd, magic, sizeof(magic));
3100
3101 for(;;) {
3102 len = read(fd, &hdr, sizeof(hdr));
3103 if (len == 0)
3104 break;
3105 if (len != sizeof(hdr)) {
3106 tcc_error_noabort("invalid archive");
3107 return -1;
3108 }
3109 memcpy(ar_size, hdr.ar_size, sizeof(hdr.ar_size));
3110 ar_size[sizeof(hdr.ar_size)] = '\0';
3111 size = strtol(ar_size, NULL, 0);
3112 memcpy(ar_name, hdr.ar_name, sizeof(hdr.ar_name));
3113 for(i = sizeof(hdr.ar_name) - 1; i >= 0; i--) {
3114 if (ar_name[i] != ' ')
3115 break;
3116 }
3117 ar_name[i + 1] = '\0';
3118 file_offset = lseek(fd, 0, SEEK_CUR);
3119 /* align to even */
3120 size = (size + 1) & ~1;
3121 if (!strcmp(ar_name, "/")) {
3122 /* coff symbol table : we handle it */
3123 if(s1->alacarte_link)
3124 return tcc_load_alacarte(s1, fd, size);
3125 } else if (!strcmp(ar_name, "//") ||
3126 !strcmp(ar_name, "__.SYMDEF") ||
3127 !strcmp(ar_name, "__.SYMDEF/") ||
3128 !strcmp(ar_name, "ARFILENAMES/")) {
3129 /* skip symbol table or archive names */
3130 } else {
3131 if (tcc_load_object_file(s1, fd, file_offset) < 0)
3132 return -1;
3133 }
3134 lseek(fd, file_offset + size, SEEK_SET);
3135 }
3136 return 0;
3137 }
3138
3139 #ifndef TCC_TARGET_PE
3140 /* load a DLL and all referenced DLLs. 'level = 0' means that the DLL
3141 is referenced by the user (so it should be added as DT_NEEDED in
3142 the generated ELF file) */
3143 ST_FUNC int tcc_load_dll(TCCState *s1, int fd, const char *filename, int level)
3144 {
3145 ElfW(Ehdr) ehdr;
3146 ElfW(Shdr) *shdr, *sh, *sh1;
3147 int i, j, nb_syms, nb_dts, sym_bind, ret;
3148 ElfW(Sym) *sym, *dynsym;
3149 ElfW(Dyn) *dt, *dynamic;
3150 unsigned char *dynstr;
3151 const char *name, *soname;
3152 DLLReference *dllref;
3153
3154 read(fd, &ehdr, sizeof(ehdr));
3155
3156 /* test CPU specific stuff */
3157 if (ehdr.e_ident[5] != ELFDATA2LSB ||
3158 ehdr.e_machine != EM_TCC_TARGET) {
3159 tcc_error_noabort("bad architecture");
3160 return -1;
3161 }
3162
3163 /* read sections */
3164 shdr = load_data(fd, ehdr.e_shoff, sizeof(ElfW(Shdr)) * ehdr.e_shnum);
3165
3166 /* load dynamic section and dynamic symbols */
3167 nb_syms = 0;
3168 nb_dts = 0;
3169 dynamic = NULL;
3170 dynsym = NULL; /* avoid warning */
3171 dynstr = NULL; /* avoid warning */
3172 for(i = 0, sh = shdr; i < ehdr.e_shnum; i++, sh++) {
3173 switch(sh->sh_type) {
3174 case SHT_DYNAMIC:
3175 nb_dts = sh->sh_size / sizeof(ElfW(Dyn));
3176 dynamic = load_data(fd, sh->sh_offset, sh->sh_size);
3177 break;
3178 case SHT_DYNSYM:
3179 nb_syms = sh->sh_size / sizeof(ElfW(Sym));
3180 dynsym = load_data(fd, sh->sh_offset, sh->sh_size);
3181 sh1 = &shdr[sh->sh_link];
3182 dynstr = load_data(fd, sh1->sh_offset, sh1->sh_size);
3183 break;
3184 default:
3185 break;
3186 }
3187 }
3188
3189 /* compute the real library name */
3190 soname = tcc_basename(filename);
3191
3192 for(i = 0, dt = dynamic; i < nb_dts; i++, dt++) {
3193 if (dt->d_tag == DT_SONAME) {
3194 soname = (char *) dynstr + dt->d_un.d_val;
3195 }
3196 }
3197
3198 /* if the dll is already loaded, do not load it */
3199 for(i = 0; i < s1->nb_loaded_dlls; i++) {
3200 dllref = s1->loaded_dlls[i];
3201 if (!strcmp(soname, dllref->name)) {
3202 /* but update level if needed */
3203 if (level < dllref->level)
3204 dllref->level = level;
3205 ret = 0;
3206 goto the_end;
3207 }
3208 }
3209
3210 /* add the dll and its level */
3211 dllref = tcc_mallocz(sizeof(DLLReference) + strlen(soname));
3212 dllref->level = level;
3213 strcpy(dllref->name, soname);
3214 dynarray_add((void ***)&s1->loaded_dlls, &s1->nb_loaded_dlls, dllref);
3215
3216 /* add dynamic symbols in dynsym_section */
3217 for(i = 1, sym = dynsym + 1; i < nb_syms; i++, sym++) {
3218 sym_bind = ELFW(ST_BIND)(sym->st_info);
3219 if (sym_bind == STB_LOCAL)
3220 continue;
3221 name = (char *) dynstr + sym->st_name;
3222 add_elf_sym(s1->dynsymtab_section, sym->st_value, sym->st_size,
3223 sym->st_info, sym->st_other, sym->st_shndx, name);
3224 }
3225
3226 /* load all referenced DLLs */
3227 for(i = 0, dt = dynamic; i < nb_dts; i++, dt++) {
3228 switch(dt->d_tag) {
3229 case DT_NEEDED:
3230 name = (char *) dynstr + dt->d_un.d_val;
3231 for(j = 0; j < s1->nb_loaded_dlls; j++) {
3232 dllref = s1->loaded_dlls[j];
3233 if (!strcmp(name, dllref->name))
3234 goto already_loaded;
3235 }
3236 if (tcc_add_dll(s1, name, AFF_REFERENCED_DLL) < 0) {
3237 tcc_error_noabort("referenced dll '%s' not found", name);
3238 ret = -1;
3239 goto the_end;
3240 }
3241 already_loaded:
3242 break;
3243 }
3244 }
3245 ret = 0;
3246 the_end:
3247 tcc_free(dynstr);
3248 tcc_free(dynsym);
3249 tcc_free(dynamic);
3250 tcc_free(shdr);
3251 return ret;
3252 }
3253
3254 #define LD_TOK_NAME 256
3255 #define LD_TOK_EOF (-1)
3256
3257 /* return next ld script token */
3258 static int ld_next(TCCState *s1, char *name, int name_size)
3259 {
3260 int c;
3261 char *q;
3262
3263 redo:
3264 switch(ch) {
3265 case ' ':
3266 case '\t':
3267 case '\f':
3268 case '\v':
3269 case '\r':
3270 case '\n':
3271 inp();
3272 goto redo;
3273 case '/':
3274 minp();
3275 if (ch == '*') {
3276 file->buf_ptr = parse_comment(file->buf_ptr);
3277 ch = file->buf_ptr[0];
3278 goto redo;
3279 } else {
3280 q = name;
3281 *q++ = '/';
3282 goto parse_name;
3283 }
3284 break;
3285 /* case 'a' ... 'z': */
3286 case 'a':
3287 case 'b':
3288 case 'c':
3289 case 'd':
3290 case 'e':
3291 case 'f':
3292 case 'g':
3293 case 'h':
3294 case 'i':
3295 case 'j':
3296 case 'k':
3297 case 'l':
3298 case 'm':
3299 case 'n':
3300 case 'o':
3301 case 'p':
3302 case 'q':
3303 case 'r':
3304 case 's':
3305 case 't':
3306 case 'u':
3307 case 'v':
3308 case 'w':
3309 case 'x':
3310 case 'y':
3311 case 'z':
3312 /* case 'A' ... 'z': */
3313 case 'A':
3314 case 'B':
3315 case 'C':
3316 case 'D':
3317 case 'E':
3318 case 'F':
3319 case 'G':
3320 case 'H':
3321 case 'I':
3322 case 'J':
3323 case 'K':
3324 case 'L':
3325 case 'M':
3326 case 'N':
3327 case 'O':
3328 case 'P':
3329 case 'Q':
3330 case 'R':
3331 case 'S':
3332 case 'T':
3333 case 'U':
3334 case 'V':
3335 case 'W':
3336 case 'X':
3337 case 'Y':
3338 case 'Z':
3339 case '_':
3340 case '\\':
3341 case '.':
3342 case '$':
3343 case '~':
3344 q = name;
3345 parse_name:
3346 for(;;) {
3347 if (!((ch >= 'a' && ch <= 'z') ||
3348 (ch >= 'A' && ch <= 'Z') ||
3349 (ch >= '0' && ch <= '9') ||
3350 strchr("/.-_+=$:\\,~", ch)))
3351 break;
3352 if ((q - name) < name_size - 1) {
3353 *q++ = ch;
3354 }
3355 minp();
3356 }
3357 *q = '\0';
3358 c = LD_TOK_NAME;
3359 break;
3360 case CH_EOF:
3361 c = LD_TOK_EOF;
3362 break;
3363 default:
3364 c = ch;
3365 inp();
3366 break;
3367 }
3368 return c;
3369 }
3370
3371 static int ld_add_file(TCCState *s1, const char filename[])
3372 {
3373 int ret;
3374
3375 ret = tcc_add_file_internal(s1, filename, 0);
3376 if (ret)
3377 ret = tcc_add_dll(s1, filename, 0);
3378 return ret;
3379 }
3380
3381 static inline int new_undef_syms(void)
3382 {
3383 int ret = 0;
3384 ret = new_undef_sym;
3385 new_undef_sym = 0;
3386 return ret;
3387 }
3388
3389 static int ld_add_file_list(TCCState *s1, const char *cmd, int as_needed)
3390 {
3391 char filename[1024], libname[1024];
3392 int t, group, nblibs = 0, ret = 0;
3393 char **libs = NULL;
3394
3395 group = !strcmp(cmd, "GROUP");
3396 if (!as_needed)
3397 new_undef_syms();
3398 t = ld_next(s1, filename, sizeof(filename));
3399 if (t != '(')
3400 expect("(");
3401 t = ld_next(s1, filename, sizeof(filename));
3402 for(;;) {
3403 libname[0] = '\0';
3404 if (t == LD_TOK_EOF) {
3405 tcc_error_noabort("unexpected end of file");
3406 ret = -1;
3407 goto lib_parse_error;
3408 } else if (t == ')') {
3409 break;
3410 } else if (t == '-') {
3411 t = ld_next(s1, filename, sizeof(filename));
3412 if ((t != LD_TOK_NAME) || (filename[0] != 'l')) {
3413 tcc_error_noabort("library name expected");
3414 ret = -1;
3415 goto lib_parse_error;
3416 }
3417 pstrcpy(libname, sizeof libname, &filename[1]);
3418 if (s1->static_link) {
3419 snprintf(filename, sizeof filename, "lib%s.a", libname);
3420 } else {
3421 snprintf(filename, sizeof filename, "lib%s.so", libname);
3422 }
3423 } else if (t != LD_TOK_NAME) {
3424 tcc_error_noabort("filename expected");
3425 ret = -1;
3426 goto lib_parse_error;
3427 }
3428 if (!strcmp(filename, "AS_NEEDED")) {
3429 ret = ld_add_file_list(s1, cmd, 1);
3430 if (ret)
3431 goto lib_parse_error;
3432 } else {
3433 /* TODO: Implement AS_NEEDED support. Ignore it for now */
3434 if (!as_needed) {
3435 ret = ld_add_file(s1, filename);
3436 if (ret)
3437 goto lib_parse_error;
3438 if (group) {
3439 /* Add the filename *and* the libname to avoid future conversions */
3440 dynarray_add((void ***) &libs, &nblibs, tcc_strdup(filename));
3441 if (libname[0] != '\0')
3442 dynarray_add((void ***) &libs, &nblibs, tcc_strdup(libname));
3443 }
3444 }
3445 }
3446 t = ld_next(s1, filename, sizeof(filename));
3447 if (t == ',') {
3448 t = ld_next(s1, filename, sizeof(filename));
3449 }
3450 }
3451 if (group && !as_needed) {
3452 while (new_undef_syms()) {
3453 int i;
3454
3455 for (i = 0; i < nblibs; i ++)
3456 ld_add_file(s1, libs[i]);
3457 }
3458 }
3459 lib_parse_error:
3460 dynarray_reset(&libs, &nblibs);
3461 return ret;
3462 }
3463
3464 /* interpret a subset of GNU ldscripts to handle the dummy libc.so
3465 files */
3466 ST_FUNC int tcc_load_ldscript(TCCState *s1)
3467 {
3468 char cmd[64];
3469 char filename[1024];
3470 int t, ret;
3471
3472 ch = file->buf_ptr[0];
3473 ch = handle_eob();
3474 for(;;) {
3475 t = ld_next(s1, cmd, sizeof(cmd));
3476 if (t == LD_TOK_EOF)
3477 return 0;
3478 else if (t != LD_TOK_NAME)
3479 return -1;
3480 if (!strcmp(cmd, "INPUT") ||
3481 !strcmp(cmd, "GROUP")) {
3482 ret = ld_add_file_list(s1, cmd, 0);
3483 if (ret)
3484 return ret;
3485 } else if (!strcmp(cmd, "OUTPUT_FORMAT") ||
3486 !strcmp(cmd, "TARGET")) {
3487 /* ignore some commands */
3488 t = ld_next(s1, cmd, sizeof(cmd));
3489 if (t != '(')
3490 expect("(");
3491 for(;;) {
3492 t = ld_next(s1, filename, sizeof(filename));
3493 if (t == LD_TOK_EOF) {
3494 tcc_error_noabort("unexpected end of file");
3495 return -1;
3496 } else if (t == ')') {
3497 break;
3498 }
3499 }
3500 } else {
3501 return -1;
3502 }
3503 }
3504 return 0;
3505 }
3506 #endif /* !TCC_TARGET_PE */
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