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tcc help output for the -xc -xa - options
[tinycc.git] / tccelf.c
blobf9a8cedaf27938dee1d4333285c00c70c8bac4f9
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 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1452 }
1453 if (type == R_X86_64_GOT32 || type == R_X86_64_GOTPCREL ||
1454 type == R_X86_64_PLT32) {
1455 unsigned long ofs;
1456 /* look at the symbol got offset. If none, then add one */
1457 if (type == R_X86_64_GOT32 || type == R_X86_64_GOTPCREL)
1458 reloc_type = R_X86_64_GLOB_DAT;
1459 else
1460 reloc_type = R_X86_64_JUMP_SLOT;
1461 ofs = put_got_entry(s1, reloc_type, sym->st_size,
1462 sym->st_info, sym_index);
1463 if (type == R_X86_64_PLT32)
1464 /* We store the place of the generated PLT slot
1465 in our addend. */
1466 rel->r_addend += ofs;
1467 }
1468 break;
1469 #else
1470 #error unsupported CPU
1471 #endif
1472 default:
1473 break;
1474 }
1475 }
1476 }
1477 }
1478
1479 ST_FUNC Section *new_symtab(TCCState *s1,
1480 const char *symtab_name, int sh_type, int sh_flags,
1481 const char *strtab_name,
1482 const char *hash_name, int hash_sh_flags)
1483 {
1484 Section *symtab, *strtab, *hash;
1485 int *ptr, nb_buckets;
1486
1487 symtab = new_section(s1, symtab_name, sh_type, sh_flags);
1488 symtab->sh_entsize = sizeof(ElfW(Sym));
1489 strtab = new_section(s1, strtab_name, SHT_STRTAB, sh_flags);
1490 put_elf_str(strtab, "");
1491 symtab->link = strtab;
1492 put_elf_sym(symtab, 0, 0, 0, 0, 0, NULL);
1493
1494 nb_buckets = 1;
1495
1496 hash = new_section(s1, hash_name, SHT_HASH, hash_sh_flags);
1497 hash->sh_entsize = sizeof(int);
1498 symtab->hash = hash;
1499 hash->link = symtab;
1500
1501 ptr = section_ptr_add(hash, (2 + nb_buckets + 1) * sizeof(int));
1502 ptr[0] = nb_buckets;
1503 ptr[1] = 1;
1504 memset(ptr + 2, 0, (nb_buckets + 1) * sizeof(int));
1505 return symtab;
1506 }
1507
1508 /* put dynamic tag */
1509 static void put_dt(Section *dynamic, int dt, addr_t val)
1510 {
1511 ElfW(Dyn) *dyn;
1512 dyn = section_ptr_add(dynamic, sizeof(ElfW(Dyn)));
1513 dyn->d_tag = dt;
1514 dyn->d_un.d_val = val;
1515 }
1516
1517 static void add_init_array_defines(TCCState *s1, const char *section_name)
1518 {
1519 Section *s;
1520 long end_offset;
1521 char sym_start[1024];
1522 char sym_end[1024];
1523
1524 snprintf(sym_start, sizeof(sym_start), "__%s_start", section_name + 1);
1525 snprintf(sym_end, sizeof(sym_end), "__%s_end", section_name + 1);
1526
1527 s = find_section(s1, section_name);
1528 if (!s) {
1529 end_offset = 0;
1530 s = data_section;
1531 } else {
1532 end_offset = s->data_offset;
1533 }
1534
1535 add_elf_sym(symtab_section,
1536 0, 0,
1537 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1538 s->sh_num, sym_start);
1539 add_elf_sym(symtab_section,
1540 end_offset, 0,
1541 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1542 s->sh_num, sym_end);
1543 }
1544
1545 static int tcc_add_support(TCCState *s1, const char *filename)
1546 {
1547 char buf[1024];
1548 snprintf(buf, sizeof(buf), "%s/%s/%s", s1->tcc_lib_path,
1549 /* an cpu specific path inside tcc_lib_path, mainly for keeping libtcc1.a */
1550 #ifdef TCC_TARGET_I386
1551 "i386"
1552 #endif
1553 #ifdef TCC_TARGET_X86_64
1554 "x86-64"
1555 #endif
1556 #ifdef TCC_TARGET_ARM
1557 "arm"
1558 #endif
1559 #ifdef TCC_TARGET_ARM64
1560 "arm64"
1561 #endif
1562 #ifdef TCC_TARGET_C67
1563 "C67"
1564 #endif
1565 ,filename);
1566
1567 return tcc_add_file(s1, buf, TCC_FILETYPE_BINARY);
1568 }
1569
1570 ST_FUNC void tcc_add_bcheck(TCCState *s1)
1571 {
1572 #ifdef CONFIG_TCC_BCHECK
1573 addr_t *ptr;
1574
1575 if (0 == s1->do_bounds_check)
1576 return;
1577
1578 /* XXX: add an object file to do that */
1579 ptr = section_ptr_add(bounds_section, sizeof(*ptr));
1580 *ptr = 0;
1581 add_elf_sym(symtab_section, 0, 0,
1582 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1583 bounds_section->sh_num, "__bounds_start");
1584 if (s1->output_type != TCC_OUTPUT_MEMORY) {
1585 /* add 'call __bound_init()' in .init section */
1586
1587 /* XXX not called on MSYS, reason is unknown. For this
1588 case a call to __bound_init is performed in bcheck.c
1589 when __bound_ptr_add, __bound_new_region,
1590 __bound_delete_region called */
1591
1592 int sym_index = find_elf_sym(symtab_section, "__bound_init");
1593 if (sym_index) {
1594 Section *init_section = find_section(s1, ".init");
1595 unsigned char *pinit = section_ptr_add(init_section, 5);
1596 pinit[0] = 0xe8;
1597 put32(pinit + 1, -4);
1598 put_elf_reloc(symtab_section, init_section,
1599 init_section->data_offset - 4, R_386_PC32, sym_index);
1600 }
1601 else
1602 tcc_warning("__bound_init not defined");
1603 }
1604 #endif
1605 }
1606
1607 /* add tcc runtime libraries */
1608 ST_FUNC void tcc_add_runtime(TCCState *s1)
1609 {
1610 tcc_add_pragma_libs(s1);
1611
1612 /* add libc */
1613 if (!s1->nostdlib) {
1614 tcc_add_library(s1, "c");
1615 #ifdef CONFIG_USE_LIBGCC
1616 if (!s1->static_link) {
1617 tcc_add_file(s1, TCC_LIBGCC, TCC_FILETYPE_BINARY);
1618 }
1619 #endif
1620 tcc_add_support(s1, "libtcc1.a");
1621 }
1622
1623 /* tcc_add_bcheck tries to relocate a call to __bound_init in _init so
1624 libtcc1.a must be loaded before for __bound_init to be defined and
1625 crtn.o must be loaded after to not finalize _init too early. */
1626 tcc_add_bcheck(s1);
1627
1628 if (!s1->nostdlib) {
1629 /* add crt end if not memory output */
1630 if (s1->output_type != TCC_OUTPUT_MEMORY)
1631 tcc_add_crt(s1, "crtn.o");
1632 }
1633 }
1634
1635 /* add various standard linker symbols (must be done after the
1636 sections are filled (for example after allocating common
1637 symbols)) */
1638 ST_FUNC void tcc_add_linker_symbols(TCCState *s1)
1639 {
1640 char buf[1024];
1641 int i;
1642 Section *s;
1643
1644 add_elf_sym(symtab_section,
1645 text_section->data_offset, 0,
1646 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1647 text_section->sh_num, "_etext");
1648 add_elf_sym(symtab_section,
1649 data_section->data_offset, 0,
1650 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1651 data_section->sh_num, "_edata");
1652 add_elf_sym(symtab_section,
1653 bss_section->data_offset, 0,
1654 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1655 bss_section->sh_num, "_end");
1656 /* horrible new standard ldscript defines */
1657 add_init_array_defines(s1, ".preinit_array");
1658 add_init_array_defines(s1, ".init_array");
1659 add_init_array_defines(s1, ".fini_array");
1660
1661 /* add start and stop symbols for sections whose name can be
1662 expressed in C */
1663 for(i = 1; i < s1->nb_sections; i++) {
1664 s = s1->sections[i];
1665 if (s->sh_type == SHT_PROGBITS &&
1666 (s->sh_flags & SHF_ALLOC)) {
1667 const char *p;
1668 int ch;
1669
1670 /* check if section name can be expressed in C */
1671 p = s->name;
1672 for(;;) {
1673 ch = *p;
1674 if (!ch)
1675 break;
1676 if (!isid(ch) && !isnum(ch))
1677 goto next_sec;
1678 p++;
1679 }
1680 snprintf(buf, sizeof(buf), "__start_%s", s->name);
1681 add_elf_sym(symtab_section,
1682 0, 0,
1683 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1684 s->sh_num, buf);
1685 snprintf(buf, sizeof(buf), "__stop_%s", s->name);
1686 add_elf_sym(symtab_section,
1687 s->data_offset, 0,
1688 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1689 s->sh_num, buf);
1690 }
1691 next_sec: ;
1692 }
1693 }
1694
1695 static void tcc_output_binary(TCCState *s1, FILE *f,
1696 const int *sec_order)
1697 {
1698 Section *s;
1699 int i, offset, size;
1700
1701 offset = 0;
1702 for(i=1;i<s1->nb_sections;i++) {
1703 s = s1->sections[sec_order[i]];
1704 if (s->sh_type != SHT_NOBITS &&
1705 (s->sh_flags & SHF_ALLOC)) {
1706 while (offset < s->sh_offset) {
1707 fputc(0, f);
1708 offset++;
1709 }
1710 size = s->sh_size;
1711 fwrite(s->data, 1, size, f);
1712 offset += size;
1713 }
1714 }
1715 }
1716
1717 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1718 #define HAVE_PHDR 1
1719 #define EXTRA_RELITEMS 14
1720
1721 /* move the relocation value from .dynsym to .got */
1722 void patch_dynsym_undef(TCCState *s1, Section *s)
1723 {
1724 uint32_t *gotd = (void *)s1->got->data;
1725 ElfW(Sym) *sym;
1726
1727 gotd += 3; /* dummy entries in .got */
1728 /* relocate symbols in .dynsym */
1729 for_each_elem(s, 1, sym, ElfW(Sym)) {
1730 if (sym->st_shndx == SHN_UNDEF) {
1731 *gotd++ = sym->st_value + 6; /* XXX 6 is magic ? */
1732 sym->st_value = 0;
1733 }
1734 }
1735 }
1736 #else
1737 #define HAVE_PHDR 1
1738 #define EXTRA_RELITEMS 9
1739
1740 /* zero plt offsets of weak symbols in .dynsym */
1741 void patch_dynsym_undef(TCCState *s1, Section *s)
1742 {
1743 ElfW(Sym) *sym;
1744
1745 for_each_elem(s, 1, sym, ElfW(Sym))
1746 if (sym->st_shndx == SHN_UNDEF && ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
1747 sym->st_value = 0;
1748 }
1749 #endif
1750
1751 ST_FUNC void fill_got_entry(TCCState *s1, ElfW_Rel *rel)
1752 {
1753 int sym_index = ELFW(R_SYM) (rel->r_info);
1754 ElfW(Sym) *sym = &((ElfW(Sym) *) symtab_section->data)[sym_index];
1755 unsigned long offset;
1756
1757 if (sym_index >= s1->nb_sym_attrs)
1758 return;
1759 offset = s1->sym_attrs[sym_index].got_offset;
1760 section_reserve(s1->got, offset + PTR_SIZE);
1761 #ifdef TCC_TARGET_X86_64
1762 /* only works for x86-64 */
1763 put32(s1->got->data + offset + 4, sym->st_value >> 32);
1764 #endif
1765 put32(s1->got->data + offset, sym->st_value & 0xffffffff);
1766 }
1767
1768 /* Perform relocation to GOT or PLT entries */
1769 ST_FUNC void fill_got(TCCState *s1)
1770 {
1771 Section *s;
1772 ElfW_Rel *rel;
1773 int i;
1774
1775 for(i = 1; i < s1->nb_sections; i++) {
1776 s = s1->sections[i];
1777 if (s->sh_type != SHT_RELX)
1778 continue;
1779 /* no need to handle got relocations */
1780 if (s->link != symtab_section)
1781 continue;
1782 for_each_elem(s, 0, rel, ElfW_Rel) {
1783 switch (ELFW(R_TYPE) (rel->r_info)) {
1784 case R_X86_64_GOT32:
1785 case R_X86_64_GOTPCREL:
1786 case R_X86_64_PLT32:
1787 fill_got_entry(s1, rel);
1788 break;
1789 }
1790 }
1791 }
1792 }
1793
1794 /* Bind symbols of executable: resolve undefined symbols from exported symbols
1795 in shared libraries and export non local defined symbols to shared libraries
1796 if -rdynamic switch was given on command line */
1797 static void bind_exe_dynsyms(TCCState *s1)
1798 {
1799 const char *name;
1800 int sym_index, index;
1801 ElfW(Sym) *sym, *esym;
1802 int type;
1803
1804 /* Resolve undefined symbols from dynamic symbols. When there is a match:
1805 - if STT_FUNC or STT_GNU_IFUNC symbol -> add it in PLT
1806 - if STT_OBJECT symbol -> add it in .bss section with suitable reloc */
1807 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
1808 if (sym->st_shndx == SHN_UNDEF) {
1809 name = (char *) symtab_section->link->data + sym->st_name;
1810 sym_index = find_elf_sym(s1->dynsymtab_section, name);
1811 if (sym_index) {
1812 esym = &((ElfW(Sym) *)s1->dynsymtab_section->data)[sym_index];
1813 type = ELFW(ST_TYPE)(esym->st_info);
1814 if ((type == STT_FUNC) || (type == STT_GNU_IFUNC)) {
1815 /* Indirect functions shall have STT_FUNC type in executable
1816 * dynsym section. Indeed, a dlsym call following a lazy
1817 * resolution would pick the symbol value from the
1818 * executable dynsym entry which would contain the address
1819 * of the function wanted by the caller of dlsym instead of
1820 * the address of the function that would return that
1821 * address */
1822 put_got_entry(s1, R_JMP_SLOT, esym->st_size,
1823 ELFW(ST_INFO)(STB_GLOBAL,STT_FUNC),
1824 sym - (ElfW(Sym) *)symtab_section->data);
1825 } else if (type == STT_OBJECT) {
1826 unsigned long offset;
1827 ElfW(Sym) *dynsym;
1828 offset = bss_section->data_offset;
1829 /* XXX: which alignment ? */
1830 offset = (offset + 16 - 1) & -16;
1831 index = put_elf_sym(s1->dynsym, offset, esym->st_size,
1832 esym->st_info, 0, bss_section->sh_num,
1833 name);
1834 /* Ensure R_COPY works for weak symbol aliases */
1835 if (ELFW(ST_BIND)(esym->st_info) == STB_WEAK) {
1836 for_each_elem(s1->dynsymtab_section, 1, dynsym, ElfW(Sym)) {
1837 if ((dynsym->st_value == esym->st_value)
1838 && (ELFW(ST_BIND)(dynsym->st_info) == STB_GLOBAL)) {
1839 char *dynname = (char *) s1->dynsymtab_section->link->data
1840 + dynsym->st_name;
1841 put_elf_sym(s1->dynsym, offset, dynsym->st_size,
1842 dynsym->st_info, 0,
1843 bss_section->sh_num, dynname);
1844 break;
1845 }
1846 }
1847 }
1848 put_elf_reloc(s1->dynsym, bss_section,
1849 offset, R_COPY, index);
1850 offset += esym->st_size;
1851 bss_section->data_offset = offset;
1852 }
1853 } else {
1854 /* STB_WEAK undefined symbols are accepted */
1855 /* XXX: _fp_hw seems to be part of the ABI, so we ignore it */
1856 if (ELFW(ST_BIND)(sym->st_info) == STB_WEAK ||
1857 !strcmp(name, "_fp_hw")) {
1858 } else {
1859 tcc_error_noabort("undefined symbol '%s'", name);
1860 }
1861 }
1862 } else if (s1->rdynamic && ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
1863 /* if -rdynamic option, then export all non local symbols */
1864 name = (char *) symtab_section->link->data + sym->st_name;
1865 put_elf_sym(s1->dynsym, sym->st_value, sym->st_size, sym->st_info,
1866 0, sym->st_shndx, name);
1867 }
1868 }
1869 }
1870
1871 /* Bind symbols of libraries: export non local symbols of executable that
1872 resolve undefined symbols of shared libraries */
1873 static void bind_libs_dynsyms(TCCState *s1)
1874 {
1875 const char *name;
1876 int sym_index;
1877 ElfW(Sym) *sym, *esym;
1878
1879 /* now look at unresolved dynamic symbols and export
1880 corresponding symbol */
1881 for_each_elem(s1->dynsymtab_section, 1, esym, ElfW(Sym)) {
1882 name = (char *) s1->dynsymtab_section->link->data + esym->st_name;
1883 sym_index = find_elf_sym(symtab_section, name);
1884 if (sym_index) {
1885 /* XXX: avoid adding a symbol if already present because of
1886 -rdynamic ? */
1887 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1888 if (sym->st_shndx != SHN_UNDEF)
1889 put_elf_sym(s1->dynsym, sym->st_value, sym->st_size,
1890 sym->st_info, 0, sym->st_shndx, name);
1891 } else if (esym->st_shndx == SHN_UNDEF) {
1892 /* weak symbols can stay undefined */
1893 if (ELFW(ST_BIND)(esym->st_info) != STB_WEAK)
1894 tcc_warning("undefined dynamic symbol '%s'", name);
1895 }
1896 }
1897 }
1898
1899 /* Export all non local symbols (for shared libraries) */
1900 static void export_global_syms(TCCState *s1)
1901 {
1902 int nb_syms, dynindex, index;
1903 const char *name;
1904 ElfW(Sym) *sym;
1905
1906 nb_syms = symtab_section->data_offset / sizeof(ElfW(Sym));
1907 s1->symtab_to_dynsym = tcc_mallocz(sizeof(int) * nb_syms);
1908 for_each_elem(symtab_section, 1, sym, ElfW(Sym)) {
1909 if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
1910 name = (char *) symtab_section->link->data + sym->st_name;
1911 dynindex = put_elf_sym(s1->dynsym, sym->st_value, sym->st_size,
1912 sym->st_info, 0, sym->st_shndx, name);
1913 index = sym - (ElfW(Sym) *) symtab_section->data;
1914 s1->symtab_to_dynsym[index] = dynindex;
1915 }
1916 }
1917 }
1918
1919 /* relocate the PLT: compute addresses and offsets in the PLT now that final
1920 address for PLT and GOT are known (see fill_program_header) */
1921 ST_FUNC void relocate_plt(TCCState *s1)
1922 {
1923 uint8_t *p, *p_end;
1924
1925 if (!s1->plt)
1926 return;
1927
1928 p = s1->plt->data;
1929 p_end = p + s1->plt->data_offset;
1930 if (p < p_end) {
1931 #if defined(TCC_TARGET_I386)
1932 put32(p + 2, get32(p + 2) + s1->got->sh_addr);
1933 put32(p + 8, get32(p + 8) + s1->got->sh_addr);
1934 p += 16;
1935 while (p < p_end) {
1936 put32(p + 2, get32(p + 2) + s1->got->sh_addr);
1937 p += 16;
1938 }
1939 #elif defined(TCC_TARGET_X86_64)
1940 int x = s1->got->sh_addr - s1->plt->sh_addr - 6;
1941 put32(p + 2, get32(p + 2) + x);
1942 put32(p + 8, get32(p + 8) + x - 6);
1943 p += 16;
1944 while (p < p_end) {
1945 put32(p + 2, get32(p + 2) + x + s1->plt->data - p);
1946 p += 16;
1947 }
1948 #elif defined(TCC_TARGET_ARM)
1949 int x;
1950 x=s1->got->sh_addr - s1->plt->sh_addr - 12;
1951 p += 16;
1952 while (p < p_end) {
1953 if (get32(p) == 0x46c04778) /* PLT Thumb stub present */
1954 p += 4;
1955 put32(p + 12, x + get32(p + 12) + s1->plt->data - p);
1956 p += 16;
1957 }
1958 #elif defined(TCC_TARGET_ARM64)
1959 uint64_t plt = s1->plt->sh_addr;
1960 uint64_t got = s1->got->sh_addr;
1961 uint64_t off = (got >> 12) - (plt >> 12);
1962 if ((off + ((uint32_t)1 << 20)) >> 21)
1963 tcc_error("Failed relocating PLT (off=0x%lx, got=0x%lx, plt=0x%lx)", off, got, plt);
1964 put32(p, 0xa9bf7bf0); // stp x16,x30,[sp,#-16]!
1965 put32(p + 4, (0x90000010 | // adrp x16,...
1966 (off & 0x1ffffc) << 3 | (off & 3) << 29));
1967 put32(p + 8, (0xf9400211 | // ldr x17,[x16,#...]
1968 (got & 0xff8) << 7));
1969 put32(p + 12, (0x91000210 | // add x16,x16,#...
1970 (got & 0xfff) << 10));
1971 put32(p + 16, 0xd61f0220); // br x17
1972 put32(p + 20, 0xd503201f); // nop
1973 put32(p + 24, 0xd503201f); // nop
1974 put32(p + 28, 0xd503201f); // nop
1975 p += 32;
1976 while (p < p_end) {
1977 uint64_t pc = plt + (p - s1->plt->data);
1978 uint64_t addr = got +
1979 (get32(p) | (uint64_t)get32(p + 4) << 32);
1980 uint32_t off = (addr >> 12) - (pc >> 12);
1981 if ((off + ((uint32_t)1 << 20)) >> 21)
1982 tcc_error("Failed relocating PLT (off=0x%lx, addr=0x%lx, pc=0x%lx)", off, addr, pc);
1983 put32(p, (0x90000010 | // adrp x16,...
1984 (off & 0x1ffffc) << 3 | (off & 3) << 29));
1985 put32(p + 4, (0xf9400211 | // ldr x17,[x16,#...]
1986 (addr & 0xff8) << 7));
1987 put32(p + 8, (0x91000210 | // add x16,x16,#...
1988 (addr & 0xfff) << 10));
1989 put32(p + 12, 0xd61f0220); // br x17
1990 p += 16;
1991 }
1992 #elif defined(TCC_TARGET_C67)
1993 /* XXX: TODO */
1994 #else
1995 #error unsupported CPU
1996 #endif
1997 }
1998 }
1999
2000 /* Allocate strings for section names and decide if an unallocated section
2001 should be output.
2002
2003 NOTE: the strsec section comes last, so its size is also correct ! */
2004 static void alloc_sec_names(TCCState *s1, int file_type, Section *strsec)
2005 {
2006 int i;
2007 Section *s;
2008
2009 /* Allocate strings for section names */
2010 for(i = 1; i < s1->nb_sections; i++) {
2011 s = s1->sections[i];
2012 s->sh_name = put_elf_str(strsec, s->name);
2013 /* when generating a DLL, we include relocations but we may
2014 patch them */
2015 if (file_type == TCC_OUTPUT_DLL &&
2016 s->sh_type == SHT_RELX &&
2017 !(s->sh_flags & SHF_ALLOC)) {
2018 /* gr: avoid bogus relocs for empty (debug) sections */
2019 if (s1->sections[s->sh_info]->sh_flags & SHF_ALLOC)
2020 prepare_dynamic_rel(s1, s);
2021 else if (s1->do_debug)
2022 s->sh_size = s->data_offset;
2023 } else if (s1->do_debug ||
2024 file_type == TCC_OUTPUT_OBJ ||
2025 file_type == TCC_OUTPUT_EXE ||
2026 (s->sh_flags & SHF_ALLOC) ||
2027 i == (s1->nb_sections - 1)) {
2028 /* we output all sections if debug or object file */
2029 s->sh_size = s->data_offset;
2030 }
2031 }
2032 }
2033
2034 /* Info to be copied in dynamic section */
2035 struct dyn_inf {
2036 Section *dynamic;
2037 Section *dynstr;
2038 unsigned long dyn_rel_off;
2039 addr_t rel_addr;
2040 addr_t rel_size;
2041 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2042 addr_t bss_addr;
2043 addr_t bss_size;
2044 #endif
2045 };
2046
2047 /* Assign sections to segments and decide how are sections laid out when loaded
2048 in memory. This function also fills corresponding program headers. */
2049 static int layout_sections(TCCState *s1, ElfW(Phdr) *phdr, int phnum,
2050 Section *interp, Section* strsec,
2051 struct dyn_inf *dyninf, int *sec_order)
2052 {
2053 int i, j, k, file_type, sh_order_index, file_offset;
2054 unsigned long s_align;
2055 long long tmp;
2056 addr_t addr;
2057 ElfW(Phdr) *ph;
2058 Section *s;
2059
2060 file_type = s1->output_type;
2061 sh_order_index = 1;
2062 file_offset = 0;
2063 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF)
2064 file_offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr));
2065 s_align = ELF_PAGE_SIZE;
2066 if (s1->section_align)
2067 s_align = s1->section_align;
2068
2069 if (phnum > 0) {
2070 if (s1->has_text_addr) {
2071 int a_offset, p_offset;
2072 addr = s1->text_addr;
2073 /* we ensure that (addr % ELF_PAGE_SIZE) == file_offset %
2074 ELF_PAGE_SIZE */
2075 a_offset = (int) (addr & (s_align - 1));
2076 p_offset = file_offset & (s_align - 1);
2077 if (a_offset < p_offset)
2078 a_offset += s_align;
2079 file_offset += (a_offset - p_offset);
2080 } else {
2081 if (file_type == TCC_OUTPUT_DLL)
2082 addr = 0;
2083 else
2084 addr = ELF_START_ADDR;
2085 /* compute address after headers */
2086 addr += (file_offset & (s_align - 1));
2087 }
2088
2089 ph = &phdr[0];
2090 /* Leave one program headers for the program interpreter and one for
2091 the program header table itself if needed. These are done later as
2092 they require section layout to be done first. */
2093 if (interp)
2094 ph += 1 + HAVE_PHDR;
2095
2096 /* dynamic relocation table information, for .dynamic section */
2097 dyninf->rel_addr = dyninf->rel_size = 0;
2098 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2099 dyninf->bss_addr = dyninf->bss_size = 0;
2100 #endif
2101
2102 for(j = 0; j < 2; j++) {
2103 ph->p_type = PT_LOAD;
2104 if (j == 0)
2105 ph->p_flags = PF_R | PF_X;
2106 else
2107 ph->p_flags = PF_R | PF_W;
2108 ph->p_align = s_align;
2109
2110 /* Decide the layout of sections loaded in memory. This must
2111 be done before program headers are filled since they contain
2112 info about the layout. We do the following ordering: interp,
2113 symbol tables, relocations, progbits, nobits */
2114 /* XXX: do faster and simpler sorting */
2115 for(k = 0; k < 5; k++) {
2116 for(i = 1; i < s1->nb_sections; i++) {
2117 s = s1->sections[i];
2118 /* compute if section should be included */
2119 if (j == 0) {
2120 if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) !=
2121 SHF_ALLOC)
2122 continue;
2123 } else {
2124 if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) !=
2125 (SHF_ALLOC | SHF_WRITE))
2126 continue;
2127 }
2128 if (s == interp) {
2129 if (k != 0)
2130 continue;
2131 } else if (s->sh_type == SHT_DYNSYM ||
2132 s->sh_type == SHT_STRTAB ||
2133 s->sh_type == SHT_HASH) {
2134 if (k != 1)
2135 continue;
2136 } else if (s->sh_type == SHT_RELX) {
2137 if (k != 2)
2138 continue;
2139 } else if (s->sh_type == SHT_NOBITS) {
2140 if (k != 4)
2141 continue;
2142 } else {
2143 if (k != 3)
2144 continue;
2145 }
2146 sec_order[sh_order_index++] = i;
2147
2148 /* section matches: we align it and add its size */
2149 tmp = addr;
2150 addr = (addr + s->sh_addralign - 1) &
2151 ~(s->sh_addralign - 1);
2152 file_offset += (int) ( addr - tmp );
2153 s->sh_offset = file_offset;
2154 s->sh_addr = addr;
2155
2156 /* update program header infos */
2157 if (ph->p_offset == 0) {
2158 ph->p_offset = file_offset;
2159 ph->p_vaddr = addr;
2160 ph->p_paddr = ph->p_vaddr;
2161 }
2162 /* update dynamic relocation infos */
2163 if (s->sh_type == SHT_RELX) {
2164 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2165 if (!strcmp(strsec->data + s->sh_name, ".rel.got")) {
2166 dyninf->rel_addr = addr;
2167 dyninf->rel_size += s->sh_size; /* XXX only first rel. */
2168 }
2169 if (!strcmp(strsec->data + s->sh_name, ".rel.bss")) {
2170 dyninf->bss_addr = addr;
2171 dyninf->bss_size = s->sh_size; /* XXX only first rel. */
2172 }
2173 #else
2174 if (dyninf->rel_size == 0)
2175 dyninf->rel_addr = addr;
2176 dyninf->rel_size += s->sh_size;
2177 #endif
2178 }
2179 addr += s->sh_size;
2180 if (s->sh_type != SHT_NOBITS)
2181 file_offset += s->sh_size;
2182 }
2183 }
2184 if (j == 0) {
2185 /* Make the first PT_LOAD segment include the program
2186 headers itself (and the ELF header as well), it'll
2187 come out with same memory use but will make various
2188 tools like binutils strip work better. */
2189 ph->p_offset &= ~(ph->p_align - 1);
2190 ph->p_vaddr &= ~(ph->p_align - 1);
2191 ph->p_paddr &= ~(ph->p_align - 1);
2192 }
2193 ph->p_filesz = file_offset - ph->p_offset;
2194 ph->p_memsz = addr - ph->p_vaddr;
2195 ph++;
2196 if (j == 0) {
2197 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF) {
2198 /* if in the middle of a page, we duplicate the page in
2199 memory so that one copy is RX and the other is RW */
2200 if ((addr & (s_align - 1)) != 0)
2201 addr += s_align;
2202 } else {
2203 addr = (addr + s_align - 1) & ~(s_align - 1);
2204 file_offset = (file_offset + s_align - 1) & ~(s_align - 1);
2205 }
2206 }
2207 }
2208 }
2209
2210 /* all other sections come after */
2211 for(i = 1; i < s1->nb_sections; i++) {
2212 s = s1->sections[i];
2213 if (phnum > 0 && (s->sh_flags & SHF_ALLOC))
2214 continue;
2215 sec_order[sh_order_index++] = i;
2216
2217 file_offset = (file_offset + s->sh_addralign - 1) &
2218 ~(s->sh_addralign - 1);
2219 s->sh_offset = file_offset;
2220 if (s->sh_type != SHT_NOBITS)
2221 file_offset += s->sh_size;
2222 }
2223
2224 return file_offset;
2225 }
2226
2227 static void fill_unloadable_phdr(ElfW(Phdr) *phdr, int phnum, Section *interp,
2228 Section *dynamic)
2229 {
2230 ElfW(Phdr) *ph;
2231
2232 /* if interpreter, then add corresponding program header */
2233 if (interp) {
2234 ph = &phdr[0];
2235
2236 if (HAVE_PHDR)
2237 {
2238 int len = phnum * sizeof(ElfW(Phdr));
2239
2240 ph->p_type = PT_PHDR;
2241 ph->p_offset = sizeof(ElfW(Ehdr));
2242 ph->p_vaddr = interp->sh_addr - len;
2243 ph->p_paddr = ph->p_vaddr;
2244 ph->p_filesz = ph->p_memsz = len;
2245 ph->p_flags = PF_R | PF_X;
2246 ph->p_align = 4; /* interp->sh_addralign; */
2247 ph++;
2248 }
2249
2250 ph->p_type = PT_INTERP;
2251 ph->p_offset = interp->sh_offset;
2252 ph->p_vaddr = interp->sh_addr;
2253 ph->p_paddr = ph->p_vaddr;
2254 ph->p_filesz = interp->sh_size;
2255 ph->p_memsz = interp->sh_size;
2256 ph->p_flags = PF_R;
2257 ph->p_align = interp->sh_addralign;
2258 }
2259
2260 /* if dynamic section, then add corresponding program header */
2261 if (dynamic) {
2262 ph = &phdr[phnum - 1];
2263
2264 ph->p_type = PT_DYNAMIC;
2265 ph->p_offset = dynamic->sh_offset;
2266 ph->p_vaddr = dynamic->sh_addr;
2267 ph->p_paddr = ph->p_vaddr;
2268 ph->p_filesz = dynamic->sh_size;
2269 ph->p_memsz = dynamic->sh_size;
2270 ph->p_flags = PF_R | PF_W;
2271 ph->p_align = dynamic->sh_addralign;
2272 }
2273 }
2274
2275 /* Fill the dynamic section with tags describing the address and size of
2276 sections */
2277 static void fill_dynamic(TCCState *s1, struct dyn_inf *dyninf)
2278 {
2279 Section *dynamic;
2280
2281 dynamic = dyninf->dynamic;
2282
2283 /* put dynamic section entries */
2284 dynamic->data_offset = dyninf->dyn_rel_off;
2285 put_dt(dynamic, DT_HASH, s1->dynsym->hash->sh_addr);
2286 put_dt(dynamic, DT_STRTAB, dyninf->dynstr->sh_addr);
2287 put_dt(dynamic, DT_SYMTAB, s1->dynsym->sh_addr);
2288 put_dt(dynamic, DT_STRSZ, dyninf->dynstr->data_offset);
2289 put_dt(dynamic, DT_SYMENT, sizeof(ElfW(Sym)));
2290 #if defined(TCC_TARGET_ARM64) || defined(TCC_TARGET_X86_64)
2291 put_dt(dynamic, DT_RELA, dyninf->rel_addr);
2292 put_dt(dynamic, DT_RELASZ, dyninf->rel_size);
2293 put_dt(dynamic, DT_RELAENT, sizeof(ElfW_Rel));
2294 #else
2295 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2296 put_dt(dynamic, DT_PLTGOT, s1->got->sh_addr);
2297 put_dt(dynamic, DT_PLTRELSZ, dyninf->rel_size);
2298 put_dt(dynamic, DT_JMPREL, dyninf->rel_addr);
2299 put_dt(dynamic, DT_PLTREL, DT_REL);
2300 put_dt(dynamic, DT_REL, dyninf->bss_addr);
2301 put_dt(dynamic, DT_RELSZ, dyninf->bss_size);
2302 #else
2303 put_dt(dynamic, DT_REL, dyninf->rel_addr);
2304 put_dt(dynamic, DT_RELSZ, dyninf->rel_size);
2305 put_dt(dynamic, DT_RELENT, sizeof(ElfW_Rel));
2306 #endif
2307 #endif
2308 if (s1->do_debug)
2309 put_dt(dynamic, DT_DEBUG, 0);
2310 put_dt(dynamic, DT_NULL, 0);
2311 }
2312
2313 /* Relocate remaining sections and symbols (that is those not related to
2314 dynamic linking) */
2315 static int final_sections_reloc(TCCState *s1)
2316 {
2317 int i;
2318 Section *s;
2319
2320 relocate_syms(s1, 0);
2321
2322 if (s1->nb_errors != 0)
2323 return -1;
2324
2325 /* relocate sections */
2326 /* XXX: ignore sections with allocated relocations ? */
2327 for(i = 1; i < s1->nb_sections; i++) {
2328 s = s1->sections[i];
2329 #ifdef TCC_TARGET_I386
2330 if (s->reloc && s != s1->got && (s->sh_flags & SHF_ALLOC)) //gr
2331 /* On X86 gdb 7.3 works in any case but gdb 6.6 will crash if SHF_ALLOC
2332 checking is removed */
2333 #else
2334 if (s->reloc && s != s1->got)
2335 /* On X86_64 gdb 7.3 will crash if SHF_ALLOC checking is present */
2336 #endif
2337 relocate_section(s1, s);
2338 }
2339
2340 /* relocate relocation entries if the relocation tables are
2341 allocated in the executable */
2342 for(i = 1; i < s1->nb_sections; i++) {
2343 s = s1->sections[i];
2344 if ((s->sh_flags & SHF_ALLOC) &&
2345 s->sh_type == SHT_RELX) {
2346 relocate_rel(s1, s);
2347 }
2348 }
2349 return 0;
2350 }
2351
2352 /* Create an ELF file on disk.
2353 This function handle ELF specific layout requirements */
2354 static void tcc_output_elf(TCCState *s1, FILE *f, int phnum, ElfW(Phdr) *phdr,
2355 int file_offset, int *sec_order)
2356 {
2357 int i, shnum, offset, size, file_type;
2358 Section *s;
2359 ElfW(Ehdr) ehdr;
2360 ElfW(Shdr) shdr, *sh;
2361
2362 file_type = s1->output_type;
2363 shnum = s1->nb_sections;
2364
2365 memset(&ehdr, 0, sizeof(ehdr));
2366
2367 if (phnum > 0) {
2368 ehdr.e_phentsize = sizeof(ElfW(Phdr));
2369 ehdr.e_phnum = phnum;
2370 ehdr.e_phoff = sizeof(ElfW(Ehdr));
2371 }
2372
2373 /* align to 4 */
2374 file_offset = (file_offset + 3) & -4;
2375
2376 /* fill header */
2377 ehdr.e_ident[0] = ELFMAG0;
2378 ehdr.e_ident[1] = ELFMAG1;
2379 ehdr.e_ident[2] = ELFMAG2;
2380 ehdr.e_ident[3] = ELFMAG3;
2381 ehdr.e_ident[4] = ELFCLASSW;
2382 ehdr.e_ident[5] = ELFDATA2LSB;
2383 ehdr.e_ident[6] = EV_CURRENT;
2384 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2385 ehdr.e_ident[EI_OSABI] = ELFOSABI_FREEBSD;
2386 #endif
2387 #ifdef TCC_TARGET_ARM
2388 #ifdef TCC_ARM_EABI
2389 ehdr.e_ident[EI_OSABI] = 0;
2390 ehdr.e_flags = EF_ARM_EABI_VER4;
2391 if (file_type == TCC_OUTPUT_EXE || file_type == TCC_OUTPUT_DLL)
2392 ehdr.e_flags |= EF_ARM_HASENTRY;
2393 if (s1->float_abi == ARM_HARD_FLOAT)
2394 ehdr.e_flags |= EF_ARM_VFP_FLOAT;
2395 else
2396 ehdr.e_flags |= EF_ARM_SOFT_FLOAT;
2397 #else
2398 ehdr.e_ident[EI_OSABI] = ELFOSABI_ARM;
2399 #endif
2400 #endif
2401 switch(file_type) {
2402 default:
2403 case TCC_OUTPUT_EXE:
2404 ehdr.e_type = ET_EXEC;
2405 ehdr.e_entry = get_elf_sym_addr(s1, "_start", 1);
2406 break;
2407 case TCC_OUTPUT_DLL:
2408 ehdr.e_type = ET_DYN;
2409 ehdr.e_entry = text_section->sh_addr; /* XXX: is it correct ? */
2410 break;
2411 case TCC_OUTPUT_OBJ:
2412 ehdr.e_type = ET_REL;
2413 break;
2414 }
2415 ehdr.e_machine = EM_TCC_TARGET;
2416 ehdr.e_version = EV_CURRENT;
2417 ehdr.e_shoff = file_offset;
2418 ehdr.e_ehsize = sizeof(ElfW(Ehdr));
2419 ehdr.e_shentsize = sizeof(ElfW(Shdr));
2420 ehdr.e_shnum = shnum;
2421 ehdr.e_shstrndx = shnum - 1;
2422
2423 fwrite(&ehdr, 1, sizeof(ElfW(Ehdr)), f);
2424 fwrite(phdr, 1, phnum * sizeof(ElfW(Phdr)), f);
2425 offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr));
2426
2427 sort_syms(s1, symtab_section);
2428 for(i = 1; i < s1->nb_sections; i++) {
2429 s = s1->sections[sec_order[i]];
2430 if (s->sh_type != SHT_NOBITS) {
2431 if (s->sh_type == SHT_DYNSYM)
2432 patch_dynsym_undef(s1, s);
2433 while (offset < s->sh_offset) {
2434 fputc(0, f);
2435 offset++;
2436 }
2437 size = s->sh_size;
2438 fwrite(s->data, 1, size, f);
2439 offset += size;
2440 }
2441 }
2442
2443 /* output section headers */
2444 while (offset < ehdr.e_shoff) {
2445 fputc(0, f);
2446 offset++;
2447 }
2448
2449 for(i = 0; i < s1->nb_sections; i++) {
2450 sh = &shdr;
2451 memset(sh, 0, sizeof(ElfW(Shdr)));
2452 s = s1->sections[i];
2453 if (s) {
2454 sh->sh_name = s->sh_name;
2455 sh->sh_type = s->sh_type;
2456 sh->sh_flags = s->sh_flags;
2457 sh->sh_entsize = s->sh_entsize;
2458 sh->sh_info = s->sh_info;
2459 if (s->link)
2460 sh->sh_link = s->link->sh_num;
2461 sh->sh_addralign = s->sh_addralign;
2462 sh->sh_addr = s->sh_addr;
2463 sh->sh_offset = s->sh_offset;
2464 sh->sh_size = s->sh_size;
2465 }
2466 fwrite(sh, 1, sizeof(ElfW(Shdr)), f);
2467 }
2468 }
2469
2470 /* Write an elf, coff or "binary" file */
2471 static int tcc_write_elf_file(TCCState *s1, const char *filename, int phnum,
2472 ElfW(Phdr) *phdr, int file_offset, int *sec_order)
2473 {
2474 int fd, mode, file_type;
2475 FILE *f;
2476
2477 file_type = s1->output_type;
2478 if (file_type == TCC_OUTPUT_OBJ)
2479 mode = 0666;
2480 else
2481 mode = 0777;
2482 unlink(filename);
2483 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, mode);
2484 if (fd < 0) {
2485 tcc_error_noabort("could not write '%s'", filename);
2486 return -1;
2487 }
2488 f = fdopen(fd, "wb");
2489 if (s1->verbose)
2490 printf("<- %s\n", filename);
2491
2492 #ifdef TCC_TARGET_COFF
2493 if (s1->output_format == TCC_OUTPUT_FORMAT_COFF)
2494 tcc_output_coff(s1, f);
2495 else
2496 #endif
2497 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF)
2498 tcc_output_elf(s1, f, phnum, phdr, file_offset, sec_order);
2499 else
2500 tcc_output_binary(s1, f, sec_order);
2501 fclose(f);
2502
2503 return 0;
2504 }
2505
2506 /* Output an elf, coff or binary file */
2507 /* XXX: suppress unneeded sections */
2508 static int elf_output_file(TCCState *s1, const char *filename)
2509 {
2510 int i, ret, phnum, shnum, file_type, file_offset, *sec_order;
2511 struct dyn_inf dyninf;
2512 ElfW(Phdr) *phdr;
2513 ElfW(Sym) *sym;
2514 Section *strsec, *interp, *dynamic, *dynstr;
2515
2516 file_type = s1->output_type;
2517 s1->nb_errors = 0;
2518
2519 /* if linking, also link in runtime libraries (libc, libgcc, etc.) */
2520 if (file_type != TCC_OUTPUT_OBJ) {
2521 tcc_add_runtime(s1);
2522 }
2523
2524 phdr = NULL;
2525 sec_order = NULL;
2526 interp = dynamic = dynstr = NULL; /* avoid warning */
2527 dyninf.dyn_rel_off = 0; /* avoid warning */
2528
2529 if (file_type != TCC_OUTPUT_OBJ) {
2530 relocate_common_syms();
2531
2532 tcc_add_linker_symbols(s1);
2533
2534 if (!s1->static_link) {
2535 if (file_type == TCC_OUTPUT_EXE) {
2536 char *ptr;
2537 /* allow override the dynamic loader */
2538 const char *elfint = getenv("LD_SO");
2539 if (elfint == NULL)
2540 elfint = DEFAULT_ELFINTERP(s1);
2541 /* add interpreter section only if executable */
2542 interp = new_section(s1, ".interp", SHT_PROGBITS, SHF_ALLOC);
2543 interp->sh_addralign = 1;
2544 ptr = section_ptr_add(interp, 1 + strlen(elfint));
2545 strcpy(ptr, elfint);
2546 }
2547
2548 /* add dynamic symbol table */
2549 s1->dynsym = new_symtab(s1, ".dynsym", SHT_DYNSYM, SHF_ALLOC,
2550 ".dynstr",
2551 ".hash", SHF_ALLOC);
2552 dynstr = s1->dynsym->link;
2553
2554 /* add dynamic section */
2555 dynamic = new_section(s1, ".dynamic", SHT_DYNAMIC,
2556 SHF_ALLOC | SHF_WRITE);
2557 dynamic->link = dynstr;
2558 dynamic->sh_entsize = sizeof(ElfW(Dyn));
2559
2560 build_got(s1);
2561
2562 if (file_type == TCC_OUTPUT_EXE) {
2563 bind_exe_dynsyms(s1);
2564
2565 if (s1->nb_errors) {
2566 ret = -1;
2567 goto the_end;
2568 }
2569
2570 bind_libs_dynsyms(s1);
2571 } else /* shared library case: simply export all global symbols */
2572 export_global_syms(s1);
2573
2574 build_got_entries(s1);
2575
2576 /* add a list of needed dlls */
2577 for(i = 0; i < s1->nb_loaded_dlls; i++) {
2578 DLLReference *dllref = s1->loaded_dlls[i];
2579 if (dllref->level == 0)
2580 put_dt(dynamic, DT_NEEDED, put_elf_str(dynstr, dllref->name));
2581 }
2582
2583 if (s1->rpath)
2584 put_dt(dynamic, DT_RPATH, put_elf_str(dynstr, s1->rpath));
2585
2586 /* XXX: currently, since we do not handle PIC code, we
2587 must relocate the readonly segments */
2588 if (file_type == TCC_OUTPUT_DLL) {
2589 if (s1->soname)
2590 put_dt(dynamic, DT_SONAME, put_elf_str(dynstr, s1->soname));
2591 put_dt(dynamic, DT_TEXTREL, 0);
2592 }
2593
2594 if (s1->symbolic)
2595 put_dt(dynamic, DT_SYMBOLIC, 0);
2596
2597 /* add necessary space for other entries */
2598 dyninf.dyn_rel_off = dynamic->data_offset;
2599 dynamic->data_offset += sizeof(ElfW(Dyn)) * EXTRA_RELITEMS;
2600 } else {
2601 /* still need to build got entries in case of static link */
2602 build_got_entries(s1);
2603 }
2604 }
2605
2606 /* we add a section for symbols */
2607 strsec = new_section(s1, ".shstrtab", SHT_STRTAB, 0);
2608 put_elf_str(strsec, "");
2609
2610 /* compute number of sections */
2611 shnum = s1->nb_sections;
2612
2613 /* this array is used to reorder sections in the output file */
2614 sec_order = tcc_malloc(sizeof(int) * shnum);
2615 sec_order[0] = 0;
2616
2617 /* compute number of program headers */
2618 switch(file_type) {
2619 default:
2620 case TCC_OUTPUT_OBJ:
2621 phnum = 0;
2622 break;
2623 case TCC_OUTPUT_EXE:
2624 if (!s1->static_link)
2625 phnum = 4 + HAVE_PHDR;
2626 else
2627 phnum = 2;
2628 break;
2629 case TCC_OUTPUT_DLL:
2630 phnum = 3;
2631 break;
2632 }
2633
2634 /* Allocate strings for section names */
2635 alloc_sec_names(s1, file_type, strsec);
2636
2637 /* allocate program segment headers */
2638 phdr = tcc_mallocz(phnum * sizeof(ElfW(Phdr)));
2639
2640 /* compute section to program header mapping */
2641 file_offset = layout_sections(s1, phdr, phnum, interp, strsec, &dyninf,
2642 sec_order);
2643
2644 /* Fill remaining program header and finalize relocation related to dynamic
2645 linking. */
2646 if (phnum > 0) {
2647 fill_unloadable_phdr(phdr, phnum, interp, dynamic);
2648 if (dynamic) {
2649 dyninf.dynamic = dynamic;
2650 dyninf.dynstr = dynstr;
2651
2652 fill_dynamic(s1, &dyninf);
2653
2654 /* put in GOT the dynamic section address and relocate PLT */
2655 put32(s1->got->data, dynamic->sh_addr);
2656 if (file_type == TCC_OUTPUT_EXE
2657 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
2658 || file_type == TCC_OUTPUT_DLL
2659 #endif
2660 )
2661 relocate_plt(s1);
2662
2663 /* relocate symbols in .dynsym now that final addresses are known */
2664 for_each_elem(s1->dynsym, 1, sym, ElfW(Sym)) {
2665 if (sym->st_shndx == SHN_UNDEF) {
2666 /* relocate to PLT if symbol corresponds to a PLT entry,
2667 but not if it's a weak symbol */
2668 if (ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
2669 sym->st_value = 0;
2670 else if (sym->st_value)
2671 sym->st_value += s1->plt->sh_addr;
2672 } else if (sym->st_shndx < SHN_LORESERVE) {
2673 /* do symbol relocation */
2674 sym->st_value += s1->sections[sym->st_shndx]->sh_addr;
2675 }
2676 }
2677 }
2678 }
2679
2680 /* if building executable or DLL, then relocate each section
2681 except the GOT which is already relocated */
2682 if (file_type != TCC_OUTPUT_OBJ) {
2683 ret = final_sections_reloc(s1);
2684 if (ret)
2685 goto the_end;
2686 }
2687
2688 /* Perform relocation to GOT or PLT entries */
2689 if (file_type == TCC_OUTPUT_EXE && s1->static_link)
2690 fill_got(s1);
2691
2692 /* Create the ELF file with name 'filename' */
2693 ret = tcc_write_elf_file(s1, filename, phnum, phdr, file_offset, sec_order);
2694 if (s1->do_strip) {
2695 int rc;
2696 const char *strip_cmd = "sstrip "; // super strip utility from ELFkickers
2697 const char *null_dev = " 2> /dev/null";
2698 char buf[1050];
2699 snprintf(buf, sizeof(buf), "%s%s%s", strip_cmd, filename, null_dev);
2700 rc = system(buf);
2701 if (rc)
2702 system(buf+1); // call a strip utility from binutils
2703 }
2704 the_end:
2705 tcc_free(s1->symtab_to_dynsym);
2706 tcc_free(sec_order);
2707 tcc_free(phdr);
2708 tcc_free(s1->sym_attrs);
2709 s1->sym_attrs = NULL;
2710 return ret;
2711 }
2712
2713 LIBTCCAPI int tcc_output_file(TCCState *s, const char *filename)
2714 {
2715 int ret;
2716 #ifdef TCC_TARGET_PE
2717 if (s->output_type != TCC_OUTPUT_OBJ) {
2718 ret = pe_output_file(s, filename);
2719 } else
2720 #endif
2721 ret = elf_output_file(s, filename);
2722 return ret;
2723 }
2724
2725 static void *load_data(int fd, unsigned long file_offset, unsigned long size)
2726 {
2727 void *data;
2728
2729 data = tcc_malloc(size);
2730 lseek(fd, file_offset, SEEK_SET);
2731 read(fd, data, size);
2732 return data;
2733 }
2734
2735 typedef struct SectionMergeInfo {
2736 Section *s; /* corresponding existing section */
2737 unsigned long offset; /* offset of the new section in the existing section */
2738 uint8_t new_section; /* true if section 's' was added */
2739 uint8_t link_once; /* true if link once section */
2740 } SectionMergeInfo;
2741
2742 /* load an object file and merge it with current files */
2743 /* XXX: handle correctly stab (debug) info */
2744 ST_FUNC int tcc_load_object_file(TCCState *s1,
2745 int fd, unsigned long file_offset)
2746 {
2747 ElfW(Ehdr) ehdr;
2748 ElfW(Shdr) *shdr, *sh;
2749 int size, i, j, offset, offseti, nb_syms, sym_index, ret;
2750 unsigned char *strsec, *strtab;
2751 int *old_to_new_syms;
2752 char *sh_name, *name;
2753 SectionMergeInfo *sm_table, *sm;
2754 ElfW(Sym) *sym, *symtab;
2755 ElfW_Rel *rel;
2756 Section *s;
2757
2758 int stab_index;
2759 int stabstr_index;
2760
2761 stab_index = stabstr_index = 0;
2762
2763 if (read(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr))
2764 goto fail1;
2765 if (ehdr.e_ident[0] != ELFMAG0 ||
2766 ehdr.e_ident[1] != ELFMAG1 ||
2767 ehdr.e_ident[2] != ELFMAG2 ||
2768 ehdr.e_ident[3] != ELFMAG3)
2769 goto fail1;
2770 /* test if object file */
2771 if (ehdr.e_type != ET_REL)
2772 goto fail1;
2773 /* test CPU specific stuff */
2774 if (ehdr.e_ident[5] != ELFDATA2LSB ||
2775 ehdr.e_machine != EM_TCC_TARGET) {
2776 fail1:
2777 tcc_error_noabort("invalid object file");
2778 return -1;
2779 }
2780 /* read sections */
2781 shdr = load_data(fd, file_offset + ehdr.e_shoff,
2782 sizeof(ElfW(Shdr)) * ehdr.e_shnum);
2783 sm_table = tcc_mallocz(sizeof(SectionMergeInfo) * ehdr.e_shnum);
2784
2785 /* load section names */
2786 sh = &shdr[ehdr.e_shstrndx];
2787 strsec = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2788
2789 /* load symtab and strtab */
2790 old_to_new_syms = NULL;
2791 symtab = NULL;
2792 strtab = NULL;
2793 nb_syms = 0;
2794 for(i = 1; i < ehdr.e_shnum; i++) {
2795 sh = &shdr[i];
2796 if (sh->sh_type == SHT_SYMTAB) {
2797 if (symtab) {
2798 tcc_error_noabort("object must contain only one symtab");
2799 fail:
2800 ret = -1;
2801 goto the_end;
2802 }
2803 nb_syms = sh->sh_size / sizeof(ElfW(Sym));
2804 symtab = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2805 sm_table[i].s = symtab_section;
2806
2807 /* now load strtab */
2808 sh = &shdr[sh->sh_link];
2809 strtab = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2810 }
2811 }
2812
2813 /* now examine each section and try to merge its content with the
2814 ones in memory */
2815 for(i = 1; i < ehdr.e_shnum; i++) {
2816 /* no need to examine section name strtab */
2817 if (i == ehdr.e_shstrndx)
2818 continue;
2819 sh = &shdr[i];
2820 sh_name = (char *) strsec + sh->sh_name;
2821 /* ignore sections types we do not handle */
2822 if (sh->sh_type != SHT_PROGBITS &&
2823 sh->sh_type != SHT_RELX &&
2824 #ifdef TCC_ARM_EABI
2825 sh->sh_type != SHT_ARM_EXIDX &&
2826 #endif
2827 sh->sh_type != SHT_NOBITS &&
2828 sh->sh_type != SHT_PREINIT_ARRAY &&
2829 sh->sh_type != SHT_INIT_ARRAY &&
2830 sh->sh_type != SHT_FINI_ARRAY &&
2831 strcmp(sh_name, ".stabstr")
2832 )
2833 continue;
2834 if (sh->sh_addralign < 1)
2835 sh->sh_addralign = 1;
2836 /* find corresponding section, if any */
2837 for(j = 1; j < s1->nb_sections;j++) {
2838 s = s1->sections[j];
2839 if (!strcmp(s->name, sh_name)) {
2840 if (!strncmp(sh_name, ".gnu.linkonce",
2841 sizeof(".gnu.linkonce") - 1)) {
2842 /* if a 'linkonce' section is already present, we
2843 do not add it again. It is a little tricky as
2844 symbols can still be defined in
2845 it. */
2846 sm_table[i].link_once = 1;
2847 goto next;
2848 } else {
2849 goto found;
2850 }
2851 }
2852 }
2853 /* not found: create new section */
2854 s = new_section(s1, sh_name, sh->sh_type, sh->sh_flags);
2855 /* take as much info as possible from the section. sh_link and
2856 sh_info will be updated later */
2857 s->sh_addralign = sh->sh_addralign;
2858 s->sh_entsize = sh->sh_entsize;
2859 sm_table[i].new_section = 1;
2860 found:
2861 if (sh->sh_type != s->sh_type) {
2862 tcc_error_noabort("invalid section type");
2863 goto fail;
2864 }
2865
2866 /* align start of section */
2867 offset = s->data_offset;
2868
2869 if (0 == strcmp(sh_name, ".stab")) {
2870 stab_index = i;
2871 goto no_align;
2872 }
2873 if (0 == strcmp(sh_name, ".stabstr")) {
2874 stabstr_index = i;
2875 goto no_align;
2876 }
2877
2878 size = sh->sh_addralign - 1;
2879 offset = (offset + size) & ~size;
2880 if (sh->sh_addralign > s->sh_addralign)
2881 s->sh_addralign = sh->sh_addralign;
2882 s->data_offset = offset;
2883 no_align:
2884 sm_table[i].offset = offset;
2885 sm_table[i].s = s;
2886 /* concatenate sections */
2887 size = sh->sh_size;
2888 if (sh->sh_type != SHT_NOBITS) {
2889 unsigned char *ptr;
2890 lseek(fd, file_offset + sh->sh_offset, SEEK_SET);
2891 ptr = section_ptr_add(s, size);
2892 read(fd, ptr, size);
2893 } else {
2894 s->data_offset += size;
2895 }
2896 next: ;
2897 }
2898
2899 /* gr relocate stab strings */
2900 if (stab_index && stabstr_index) {
2901 Stab_Sym *a, *b;
2902 unsigned o;
2903 s = sm_table[stab_index].s;
2904 a = (Stab_Sym *)(s->data + sm_table[stab_index].offset);
2905 b = (Stab_Sym *)(s->data + s->data_offset);
2906 o = sm_table[stabstr_index].offset;
2907 while (a < b)
2908 a->n_strx += o, a++;
2909 }
2910
2911 /* second short pass to update sh_link and sh_info fields of new
2912 sections */
2913 for(i = 1; i < ehdr.e_shnum; i++) {
2914 s = sm_table[i].s;
2915 if (!s || !sm_table[i].new_section)
2916 continue;
2917 sh = &shdr[i];
2918 if (sh->sh_link > 0)
2919 s->link = sm_table[sh->sh_link].s;
2920 if (sh->sh_type == SHT_RELX) {
2921 s->sh_info = sm_table[sh->sh_info].s->sh_num;
2922 /* update backward link */
2923 s1->sections[s->sh_info]->reloc = s;
2924 }
2925 }
2926 sm = sm_table;
2927
2928 /* resolve symbols */
2929 old_to_new_syms = tcc_mallocz(nb_syms * sizeof(int));
2930
2931 sym = symtab + 1;
2932 for(i = 1; i < nb_syms; i++, sym++) {
2933 if (sym->st_shndx != SHN_UNDEF &&
2934 sym->st_shndx < SHN_LORESERVE) {
2935 sm = &sm_table[sym->st_shndx];
2936 if (sm->link_once) {
2937 /* if a symbol is in a link once section, we use the
2938 already defined symbol. It is very important to get
2939 correct relocations */
2940 if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
2941 name = (char *) strtab + sym->st_name;
2942 sym_index = find_elf_sym(symtab_section, name);
2943 if (sym_index)
2944 old_to_new_syms[i] = sym_index;
2945 }
2946 continue;
2947 }
2948 /* if no corresponding section added, no need to add symbol */
2949 if (!sm->s)
2950 continue;
2951 /* convert section number */
2952 sym->st_shndx = sm->s->sh_num;
2953 /* offset value */
2954 sym->st_value += sm->offset;
2955 }
2956 /* add symbol */
2957 name = (char *) strtab + sym->st_name;
2958 sym_index = add_elf_sym(symtab_section, sym->st_value, sym->st_size,
2959 sym->st_info, sym->st_other,
2960 sym->st_shndx, name);
2961 old_to_new_syms[i] = sym_index;
2962 }
2963
2964 /* third pass to patch relocation entries */
2965 for(i = 1; i < ehdr.e_shnum; i++) {
2966 s = sm_table[i].s;
2967 if (!s)
2968 continue;
2969 sh = &shdr[i];
2970 offset = sm_table[i].offset;
2971 switch(s->sh_type) {
2972 case SHT_RELX:
2973 /* take relocation offset information */
2974 offseti = sm_table[sh->sh_info].offset;
2975 for_each_elem(s, (offset / sizeof(*rel)), rel, ElfW_Rel) {
2976 int type;
2977 unsigned sym_index;
2978 /* convert symbol index */
2979 type = ELFW(R_TYPE)(rel->r_info);
2980 sym_index = ELFW(R_SYM)(rel->r_info);
2981 /* NOTE: only one symtab assumed */
2982 if (sym_index >= nb_syms)
2983 goto invalid_reloc;
2984 sym_index = old_to_new_syms[sym_index];
2985 /* ignore link_once in rel section. */
2986 if (!sym_index && !sm->link_once
2987 #ifdef TCC_TARGET_ARM
2988 && type != R_ARM_V4BX
2989 #endif
2990 ) {
2991 invalid_reloc:
2992 tcc_error_noabort("Invalid relocation entry [%2d] '%s' @ %.8x",
2993 i, strsec + sh->sh_name, rel->r_offset);
2994 goto fail;
2995 }
2996 rel->r_info = ELFW(R_INFO)(sym_index, type);
2997 /* offset the relocation offset */
2998 rel->r_offset += offseti;
2999 #ifdef TCC_TARGET_ARM
3000 /* Jumps and branches from a Thumb code to a PLT entry need
3001 special handling since PLT entries are ARM code.
3002 Unconditional bl instructions referencing PLT entries are
3003 handled by converting these instructions into blx
3004 instructions. Other case of instructions referencing a PLT
3005 entry require to add a Thumb stub before the PLT entry to
3006 switch to ARM mode. We set bit plt_thumb_stub of the
3007 attribute of a symbol to indicate such a case. */
3008 if (type == R_ARM_THM_JUMP24)
3009 alloc_sym_attr(s1, sym_index)->plt_thumb_stub = 1;
3010 #endif
3011 }
3012 break;
3013 default:
3014 break;
3015 }
3016 }
3017
3018 ret = 0;
3019 the_end:
3020 tcc_free(symtab);
3021 tcc_free(strtab);
3022 tcc_free(old_to_new_syms);
3023 tcc_free(sm_table);
3024 tcc_free(strsec);
3025 tcc_free(shdr);
3026 return ret;
3027 }
3028
3029 typedef struct ArchiveHeader {
3030 char ar_name[16]; /* name of this member */
3031 char ar_date[12]; /* file mtime */
3032 char ar_uid[6]; /* owner uid; printed as decimal */
3033 char ar_gid[6]; /* owner gid; printed as decimal */
3034 char ar_mode[8]; /* file mode, printed as octal */
3035 char ar_size[10]; /* file size, printed as decimal */
3036 char ar_fmag[2]; /* should contain ARFMAG */
3037 } ArchiveHeader;
3038
3039 static int get_be32(const uint8_t *b)
3040 {
3041 return b[3] | (b[2] << 8) | (b[1] << 16) | (b[0] << 24);
3042 }
3043
3044 /* load only the objects which resolve undefined symbols */
3045 static int tcc_load_alacarte(TCCState *s1, int fd, int size)
3046 {
3047 int i, bound, nsyms, sym_index, off, ret;
3048 uint8_t *data;
3049 const char *ar_names, *p;
3050 const uint8_t *ar_index;
3051 ElfW(Sym) *sym;
3052
3053 data = tcc_malloc(size);
3054 if (read(fd, data, size) != size)
3055 goto fail;
3056 nsyms = get_be32(data);
3057 ar_index = data + 4;
3058 ar_names = (char *) ar_index + nsyms * 4;
3059
3060 do {
3061 bound = 0;
3062 for(p = ar_names, i = 0; i < nsyms; i++, p += strlen(p)+1) {
3063 sym_index = find_elf_sym(symtab_section, p);
3064 if(sym_index) {
3065 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
3066 if(sym->st_shndx == SHN_UNDEF) {
3067 off = get_be32(ar_index + i * 4) + sizeof(ArchiveHeader);
3068 ++bound;
3069 lseek(fd, off, SEEK_SET);
3070 if(tcc_load_object_file(s1, fd, off) < 0) {
3071 fail:
3072 ret = -1;
3073 goto the_end;
3074 }
3075 }
3076 }
3077 }
3078 } while(bound);
3079 ret = 0;
3080 the_end:
3081 tcc_free(data);
3082 return ret;
3083 }
3084
3085 /* load a '.a' file */
3086 ST_FUNC int tcc_load_archive(TCCState *s1, int fd)
3087 {
3088 ArchiveHeader hdr;
3089 char ar_size[11];
3090 char ar_name[17];
3091 char magic[8];
3092 int size, len, i;
3093 unsigned long file_offset;
3094
3095 /* skip magic which was already checked */
3096 read(fd, magic, sizeof(magic));
3097
3098 for(;;) {
3099 len = read(fd, &hdr, sizeof(hdr));
3100 if (len == 0)
3101 break;
3102 if (len != sizeof(hdr)) {
3103 tcc_error_noabort("invalid archive");
3104 return -1;
3105 }
3106 memcpy(ar_size, hdr.ar_size, sizeof(hdr.ar_size));
3107 ar_size[sizeof(hdr.ar_size)] = '\0';
3108 size = strtol(ar_size, NULL, 0);
3109 memcpy(ar_name, hdr.ar_name, sizeof(hdr.ar_name));
3110 for(i = sizeof(hdr.ar_name) - 1; i >= 0; i--) {
3111 if (ar_name[i] != ' ')
3112 break;
3113 }
3114 ar_name[i + 1] = '\0';
3115 file_offset = lseek(fd, 0, SEEK_CUR);
3116 /* align to even */
3117 size = (size + 1) & ~1;
3118 if (!strcmp(ar_name, "/")) {
3119 /* coff symbol table : we handle it */
3120 if(s1->alacarte_link)
3121 return tcc_load_alacarte(s1, fd, size);
3122 } else if (!strcmp(ar_name, "//") ||
3123 !strcmp(ar_name, "__.SYMDEF") ||
3124 !strcmp(ar_name, "__.SYMDEF/") ||
3125 !strcmp(ar_name, "ARFILENAMES/")) {
3126 /* skip symbol table or archive names */
3127 } else {
3128 if (tcc_load_object_file(s1, fd, file_offset) < 0)
3129 return -1;
3130 }
3131 lseek(fd, file_offset + size, SEEK_SET);
3132 }
3133 return 0;
3134 }
3135
3136 #ifndef TCC_TARGET_PE
3137 /* load a DLL and all referenced DLLs. 'level = 0' means that the DLL
3138 is referenced by the user (so it should be added as DT_NEEDED in
3139 the generated ELF file) */
3140 ST_FUNC int tcc_load_dll(TCCState *s1, int fd, const char *filename, int level)
3141 {
3142 ElfW(Ehdr) ehdr;
3143 ElfW(Shdr) *shdr, *sh, *sh1;
3144 int i, j, nb_syms, nb_dts, sym_bind, ret;
3145 ElfW(Sym) *sym, *dynsym;
3146 ElfW(Dyn) *dt, *dynamic;
3147 unsigned char *dynstr;
3148 const char *name, *soname;
3149 DLLReference *dllref;
3150
3151 read(fd, &ehdr, sizeof(ehdr));
3152
3153 /* test CPU specific stuff */
3154 if (ehdr.e_ident[5] != ELFDATA2LSB ||
3155 ehdr.e_machine != EM_TCC_TARGET) {
3156 tcc_error_noabort("bad architecture");
3157 return -1;
3158 }
3159
3160 /* read sections */
3161 shdr = load_data(fd, ehdr.e_shoff, sizeof(ElfW(Shdr)) * ehdr.e_shnum);
3162
3163 /* load dynamic section and dynamic symbols */
3164 nb_syms = 0;
3165 nb_dts = 0;
3166 dynamic = NULL;
3167 dynsym = NULL; /* avoid warning */
3168 dynstr = NULL; /* avoid warning */
3169 for(i = 0, sh = shdr; i < ehdr.e_shnum; i++, sh++) {
3170 switch(sh->sh_type) {
3171 case SHT_DYNAMIC:
3172 nb_dts = sh->sh_size / sizeof(ElfW(Dyn));
3173 dynamic = load_data(fd, sh->sh_offset, sh->sh_size);
3174 break;
3175 case SHT_DYNSYM:
3176 nb_syms = sh->sh_size / sizeof(ElfW(Sym));
3177 dynsym = load_data(fd, sh->sh_offset, sh->sh_size);
3178 sh1 = &shdr[sh->sh_link];
3179 dynstr = load_data(fd, sh1->sh_offset, sh1->sh_size);
3180 break;
3181 default:
3182 break;
3183 }
3184 }
3185
3186 /* compute the real library name */
3187 soname = tcc_basename(filename);
3188
3189 for(i = 0, dt = dynamic; i < nb_dts; i++, dt++) {
3190 if (dt->d_tag == DT_SONAME) {
3191 soname = (char *) dynstr + dt->d_un.d_val;
3192 }
3193 }
3194
3195 /* if the dll is already loaded, do not load it */
3196 for(i = 0; i < s1->nb_loaded_dlls; i++) {
3197 dllref = s1->loaded_dlls[i];
3198 if (!strcmp(soname, dllref->name)) {
3199 /* but update level if needed */
3200 if (level < dllref->level)
3201 dllref->level = level;
3202 ret = 0;
3203 goto the_end;
3204 }
3205 }
3206
3207 /* add the dll and its level */
3208 dllref = tcc_mallocz(sizeof(DLLReference) + strlen(soname));
3209 dllref->level = level;
3210 strcpy(dllref->name, soname);
3211 dynarray_add((void ***)&s1->loaded_dlls, &s1->nb_loaded_dlls, dllref);
3212
3213 /* add dynamic symbols in dynsym_section */
3214 for(i = 1, sym = dynsym + 1; i < nb_syms; i++, sym++) {
3215 sym_bind = ELFW(ST_BIND)(sym->st_info);
3216 if (sym_bind == STB_LOCAL)
3217 continue;
3218 name = (char *) dynstr + sym->st_name;
3219 add_elf_sym(s1->dynsymtab_section, sym->st_value, sym->st_size,
3220 sym->st_info, sym->st_other, sym->st_shndx, name);
3221 }
3222
3223 /* load all referenced DLLs */
3224 for(i = 0, dt = dynamic; i < nb_dts; i++, dt++) {
3225 switch(dt->d_tag) {
3226 case DT_NEEDED:
3227 name = (char *) dynstr + dt->d_un.d_val;
3228 for(j = 0; j < s1->nb_loaded_dlls; j++) {
3229 dllref = s1->loaded_dlls[j];
3230 if (!strcmp(name, dllref->name))
3231 goto already_loaded;
3232 }
3233 if (tcc_add_dll(s1, name, AFF_REFERENCED_DLL) < 0) {
3234 tcc_error_noabort("referenced dll '%s' not found", name);
3235 ret = -1;
3236 goto the_end;
3237 }
3238 already_loaded:
3239 break;
3240 }
3241 }
3242 ret = 0;
3243 the_end:
3244 tcc_free(dynstr);
3245 tcc_free(dynsym);
3246 tcc_free(dynamic);
3247 tcc_free(shdr);
3248 return ret;
3249 }
3250
3251 #define LD_TOK_NAME 256
3252 #define LD_TOK_EOF (-1)
3253
3254 /* return next ld script token */
3255 static int ld_next(TCCState *s1, char *name, int name_size)
3256 {
3257 int c;
3258 char *q;
3259
3260 redo:
3261 switch(ch) {
3262 case ' ':
3263 case '\t':
3264 case '\f':
3265 case '\v':
3266 case '\r':
3267 case '\n':
3268 inp();
3269 goto redo;
3270 case '/':
3271 minp();
3272 if (ch == '*') {
3273 file->buf_ptr = parse_comment(file->buf_ptr);
3274 ch = file->buf_ptr[0];
3275 goto redo;
3276 } else {
3277 q = name;
3278 *q++ = '/';
3279 goto parse_name;
3280 }
3281 break;
3282 case '\\':
3283 ch = handle_eob();
3284 if (ch != '\\')
3285 goto redo;
3286 /* fall through */
3287 /* case 'a' ... 'z': */
3288 case 'a':
3289 case 'b':
3290 case 'c':
3291 case 'd':
3292 case 'e':
3293 case 'f':
3294 case 'g':
3295 case 'h':
3296 case 'i':
3297 case 'j':
3298 case 'k':
3299 case 'l':
3300 case 'm':
3301 case 'n':
3302 case 'o':
3303 case 'p':
3304 case 'q':
3305 case 'r':
3306 case 's':
3307 case 't':
3308 case 'u':
3309 case 'v':
3310 case 'w':
3311 case 'x':
3312 case 'y':
3313 case 'z':
3314 /* case 'A' ... 'z': */
3315 case 'A':
3316 case 'B':
3317 case 'C':
3318 case 'D':
3319 case 'E':
3320 case 'F':
3321 case 'G':
3322 case 'H':
3323 case 'I':
3324 case 'J':
3325 case 'K':
3326 case 'L':
3327 case 'M':
3328 case 'N':
3329 case 'O':
3330 case 'P':
3331 case 'Q':
3332 case 'R':
3333 case 'S':
3334 case 'T':
3335 case 'U':
3336 case 'V':
3337 case 'W':
3338 case 'X':
3339 case 'Y':
3340 case 'Z':
3341 case '_':
3342 case '.':
3343 case '$':
3344 case '~':
3345 q = name;
3346 parse_name:
3347 for(;;) {
3348 if (!((ch >= 'a' && ch <= 'z') ||
3349 (ch >= 'A' && ch <= 'Z') ||
3350 (ch >= '0' && ch <= '9') ||
3351 strchr("/.-_+=$:\\,~", ch)))
3352 break;
3353 if ((q - name) < name_size - 1) {
3354 *q++ = ch;
3355 }
3356 minp();
3357 }
3358 *q = '\0';
3359 c = LD_TOK_NAME;
3360 break;
3361 case CH_EOF:
3362 c = LD_TOK_EOF;
3363 break;
3364 default:
3365 c = ch;
3366 inp();
3367 break;
3368 }
3369 return c;
3370 }
3371
3372 static int ld_add_file(TCCState *s1, const char filename[])
3373 {
3374 int ret;
3375
3376 ret = tcc_add_file_internal(s1, filename, 0, TCC_FILETYPE_BINARY);
3377 if (ret)
3378 ret = tcc_add_dll(s1, filename, 0);
3379 return ret;
3380 }
3381
3382 static inline int new_undef_syms(void)
3383 {
3384 int ret = 0;
3385 ret = new_undef_sym;
3386 new_undef_sym = 0;
3387 return ret;
3388 }
3389
3390 static int ld_add_file_list(TCCState *s1, const char *cmd, int as_needed)
3391 {
3392 char filename[1024], libname[1024];
3393 int t, group, nblibs = 0, ret = 0;
3394 char **libs = NULL;
3395
3396 group = !strcmp(cmd, "GROUP");
3397 if (!as_needed)
3398 new_undef_syms();
3399 t = ld_next(s1, filename, sizeof(filename));
3400 if (t != '(')
3401 expect("(");
3402 t = ld_next(s1, filename, sizeof(filename));
3403 for(;;) {
3404 libname[0] = '\0';
3405 if (t == LD_TOK_EOF) {
3406 tcc_error_noabort("unexpected end of file");
3407 ret = -1;
3408 goto lib_parse_error;
3409 } else if (t == ')') {
3410 break;
3411 } else if (t == '-') {
3412 t = ld_next(s1, filename, sizeof(filename));
3413 if ((t != LD_TOK_NAME) || (filename[0] != 'l')) {
3414 tcc_error_noabort("library name expected");
3415 ret = -1;
3416 goto lib_parse_error;
3417 }
3418 pstrcpy(libname, sizeof libname, &filename[1]);
3419 if (s1->static_link) {
3420 snprintf(filename, sizeof filename, "lib%s.a", libname);
3421 } else {
3422 snprintf(filename, sizeof filename, "lib%s.so", libname);
3423 }
3424 } else if (t != LD_TOK_NAME) {
3425 tcc_error_noabort("filename expected");
3426 ret = -1;
3427 goto lib_parse_error;
3428 }
3429 if (!strcmp(filename, "AS_NEEDED")) {
3430 ret = ld_add_file_list(s1, cmd, 1);
3431 if (ret)
3432 goto lib_parse_error;
3433 } else {
3434 /* TODO: Implement AS_NEEDED support. Ignore it for now */
3435 if (!as_needed) {
3436 ret = ld_add_file(s1, filename);
3437 if (ret)
3438 goto lib_parse_error;
3439 if (group) {
3440 /* Add the filename *and* the libname to avoid future conversions */
3441 dynarray_add((void ***) &libs, &nblibs, tcc_strdup(filename));
3442 if (libname[0] != '\0')
3443 dynarray_add((void ***) &libs, &nblibs, tcc_strdup(libname));
3444 }
3445 }
3446 }
3447 t = ld_next(s1, filename, sizeof(filename));
3448 if (t == ',') {
3449 t = ld_next(s1, filename, sizeof(filename));
3450 }
3451 }
3452 if (group && !as_needed) {
3453 while (new_undef_syms()) {
3454 int i;
3455
3456 for (i = 0; i < nblibs; i ++)
3457 ld_add_file(s1, libs[i]);
3458 }
3459 }
3460 lib_parse_error:
3461 dynarray_reset(&libs, &nblibs);
3462 return ret;
3463 }
3464
3465 /* interpret a subset of GNU ldscripts to handle the dummy libc.so
3466 files */
3467 ST_FUNC int tcc_load_ldscript(TCCState *s1)
3468 {
3469 char cmd[64];
3470 char filename[1024];
3471 int t, ret;
3472
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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