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Remove WITHOUT_LIBTCC macro: no more user
[tinycc.git] / tccelf.c
blobaec221cd6e567ba10c1f4423d19e3b20d4d319cd
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 static int new_undef_sym = 0; /* Is there a new undefined sym since last new_undef_sym() */
24
25 ST_FUNC int put_elf_str(Section *s, const char *sym)
26 {
27 int offset, len;
28 char *ptr;
29
30 len = strlen(sym) + 1;
31 offset = s->data_offset;
32 ptr = section_ptr_add(s, len);
33 memcpy(ptr, sym, len);
34 return offset;
35 }
36
37 /* elf symbol hashing function */
38 static unsigned long elf_hash(const unsigned char *name)
39 {
40 unsigned long h = 0, g;
41
42 while (*name) {
43 h = (h << 4) + *name++;
44 g = h & 0xf0000000;
45 if (g)
46 h ^= g >> 24;
47 h &= ~g;
48 }
49 return h;
50 }
51
52 /* rebuild hash table of section s */
53 /* NOTE: we do factorize the hash table code to go faster */
54 static void rebuild_hash(Section *s, unsigned int nb_buckets)
55 {
56 ElfW(Sym) *sym;
57 int *ptr, *hash, nb_syms, sym_index, h;
58 char *strtab;
59
60 strtab = s->link->data;
61 nb_syms = s->data_offset / sizeof(ElfW(Sym));
62
63 s->hash->data_offset = 0;
64 ptr = section_ptr_add(s->hash, (2 + nb_buckets + nb_syms) * sizeof(int));
65 ptr[0] = nb_buckets;
66 ptr[1] = nb_syms;
67 ptr += 2;
68 hash = ptr;
69 memset(hash, 0, (nb_buckets + 1) * sizeof(int));
70 ptr += nb_buckets + 1;
71
72 sym = (ElfW(Sym) *)s->data + 1;
73 for(sym_index = 1; sym_index < nb_syms; sym_index++) {
74 if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
75 h = elf_hash(strtab + sym->st_name) % nb_buckets;
76 *ptr = hash[h];
77 hash[h] = sym_index;
78 } else {
79 *ptr = 0;
80 }
81 ptr++;
82 sym++;
83 }
84 }
85
86 /* return the symbol number */
87 ST_FUNC int put_elf_sym(Section *s, addr_t value, unsigned long size,
88 int info, int other, int shndx, const char *name)
89 {
90 int name_offset, sym_index;
91 int nbuckets, h;
92 ElfW(Sym) *sym;
93 Section *hs;
94
95 sym = section_ptr_add(s, sizeof(ElfW(Sym)));
96 if (name)
97 name_offset = put_elf_str(s->link, name);
98 else
99 name_offset = 0;
100 /* XXX: endianness */
101 sym->st_name = name_offset;
102 sym->st_value = value;
103 sym->st_size = size;
104 sym->st_info = info;
105 sym->st_other = other;
106 sym->st_shndx = shndx;
107 sym_index = sym - (ElfW(Sym) *)s->data;
108 hs = s->hash;
109 if (hs) {
110 int *ptr, *base;
111 ptr = section_ptr_add(hs, sizeof(int));
112 base = (int *)hs->data;
113 /* only add global or weak symbols */
114 if (ELFW(ST_BIND)(info) != STB_LOCAL) {
115 /* add another hashing entry */
116 nbuckets = base[0];
117 h = elf_hash(name) % nbuckets;
118 *ptr = base[2 + h];
119 base[2 + h] = sym_index;
120 base[1]++;
121 /* we resize the hash table */
122 hs->nb_hashed_syms++;
123 if (hs->nb_hashed_syms > 2 * nbuckets) {
124 rebuild_hash(s, 2 * nbuckets);
125 }
126 } else {
127 *ptr = 0;
128 base[1]++;
129 }
130 }
131 return sym_index;
132 }
133
134 /* find global ELF symbol 'name' and return its index. Return 0 if not
135 found. */
136 ST_FUNC int find_elf_sym(Section *s, const char *name)
137 {
138 ElfW(Sym) *sym;
139 Section *hs;
140 int nbuckets, sym_index, h;
141 const char *name1;
142
143 hs = s->hash;
144 if (!hs)
145 return 0;
146 nbuckets = ((int *)hs->data)[0];
147 h = elf_hash(name) % nbuckets;
148 sym_index = ((int *)hs->data)[2 + h];
149 while (sym_index != 0) {
150 sym = &((ElfW(Sym) *)s->data)[sym_index];
151 name1 = s->link->data + sym->st_name;
152 if (!strcmp(name, name1))
153 return sym_index;
154 sym_index = ((int *)hs->data)[2 + nbuckets + sym_index];
155 }
156 return 0;
157 }
158
159 /* return elf symbol value, signal error if 'err' is nonzero */
160 ST_FUNC addr_t get_elf_sym_addr(TCCState *s, const char *name, int err)
161 {
162 int sym_index;
163 ElfW(Sym) *sym;
164
165 sym_index = find_elf_sym(s->symtab, name);
166 sym = &((ElfW(Sym) *)s->symtab->data)[sym_index];
167 if (!sym_index || sym->st_shndx == SHN_UNDEF) {
168 if (err)
169 tcc_error("%s not defined", name);
170 return 0;
171 }
172 return sym->st_value;
173 }
174
175 /* return elf symbol value */
176 LIBTCCAPI void *tcc_get_symbol(TCCState *s, const char *name)
177 {
178 return (void*)(uintptr_t)get_elf_sym_addr(s, name, 0);
179 }
180
181 #if defined TCC_IS_NATIVE || defined TCC_TARGET_PE
182 /* return elf symbol value or error */
183 ST_FUNC void* tcc_get_symbol_err(TCCState *s, const char *name)
184 {
185 return (void*)(uintptr_t)get_elf_sym_addr(s, name, 1);
186 }
187 #endif
188
189 /* add an elf symbol : check if it is already defined and patch
190 it. Return symbol index. NOTE that sh_num can be SHN_UNDEF. */
191 ST_FUNC int add_elf_sym(Section *s, addr_t value, unsigned long size,
192 int info, int other, int sh_num, const char *name)
193 {
194 ElfW(Sym) *esym;
195 int sym_bind, sym_index, sym_type, esym_bind;
196 unsigned char sym_vis, esym_vis, new_vis;
197
198 sym_bind = ELFW(ST_BIND)(info);
199 sym_type = ELFW(ST_TYPE)(info);
200 sym_vis = ELFW(ST_VISIBILITY)(other);
201
202 if (sym_bind != STB_LOCAL) {
203 /* we search global or weak symbols */
204 sym_index = find_elf_sym(s, name);
205 if (!sym_index)
206 goto do_def;
207 esym = &((ElfW(Sym) *)s->data)[sym_index];
208 if (esym->st_shndx != SHN_UNDEF) {
209 esym_bind = ELFW(ST_BIND)(esym->st_info);
210 /* propagate the most constraining visibility */
211 /* STV_DEFAULT(0)<STV_PROTECTED(3)<STV_HIDDEN(2)<STV_INTERNAL(1) */
212 esym_vis = ELFW(ST_VISIBILITY)(esym->st_other);
213 if (esym_vis == STV_DEFAULT) {
214 new_vis = sym_vis;
215 } else if (sym_vis == STV_DEFAULT) {
216 new_vis = esym_vis;
217 } else {
218 new_vis = (esym_vis < sym_vis) ? esym_vis : sym_vis;
219 }
220 esym->st_other = (esym->st_other & ~ELFW(ST_VISIBILITY)(-1))
221 | new_vis;
222 other = esym->st_other; /* in case we have to patch esym */
223 if (sh_num == SHN_UNDEF) {
224 /* ignore adding of undefined symbol if the
225 corresponding symbol is already defined */
226 } else if (sym_bind == STB_GLOBAL && esym_bind == STB_WEAK) {
227 /* global overrides weak, so patch */
228 goto do_patch;
229 } else if (sym_bind == STB_WEAK && esym_bind == STB_GLOBAL) {
230 /* weak is ignored if already global */
231 } else if (sym_bind == STB_WEAK && esym_bind == STB_WEAK) {
232 /* keep first-found weak definition, ignore subsequents */
233 } else if (sym_vis == STV_HIDDEN || sym_vis == STV_INTERNAL) {
234 /* ignore hidden symbols after */
235 } else if (esym->st_shndx == SHN_COMMON
236 && (sh_num < SHN_LORESERVE || sh_num == SHN_COMMON)) {
237 /* gr: Happens with 'tcc ... -static tcctest.c' on e.g. Ubuntu 6.01
238 No idea if this is the correct solution ... */
239 goto do_patch;
240 } else if (s == tcc_state->dynsymtab_section) {
241 /* we accept that two DLL define the same symbol */
242 } else {
243 #if 0
244 printf("new_bind=%x new_shndx=%x new_vis=%x old_bind=%x old_shndx=%x old_vis=%x\n",
245 sym_bind, sh_num, new_vis, esym_bind, esym->st_shndx, esym_vis);
246 #endif
247 tcc_error_noabort("'%s' defined twice", name);
248 }
249 } else {
250 do_patch:
251 esym->st_info = ELFW(ST_INFO)(sym_bind, sym_type);
252 esym->st_shndx = sh_num;
253 new_undef_sym = 1;
254 esym->st_value = value;
255 esym->st_size = size;
256 esym->st_other = other;
257 }
258 } else {
259 do_def:
260 sym_index = put_elf_sym(s, value, size,
261 ELFW(ST_INFO)(sym_bind, sym_type), other,
262 sh_num, name);
263 }
264 return sym_index;
265 }
266
267 /* put relocation */
268 ST_FUNC void put_elf_reloc(Section *symtab, Section *s, unsigned long offset,
269 int type, int symbol)
270 {
271 char buf[256];
272 Section *sr;
273 ElfW_Rel *rel;
274
275 sr = s->reloc;
276 if (!sr) {
277 /* if no relocation section, create it */
278 snprintf(buf, sizeof(buf), REL_SECTION_FMT, s->name);
279 /* if the symtab is allocated, then we consider the relocation
280 are also */
281 sr = new_section(tcc_state, buf, SHT_RELX, symtab->sh_flags);
282 sr->sh_entsize = sizeof(ElfW_Rel);
283 sr->link = symtab;
284 sr->sh_info = s->sh_num;
285 s->reloc = sr;
286 }
287 rel = section_ptr_add(sr, sizeof(ElfW_Rel));
288 rel->r_offset = offset;
289 rel->r_info = ELFW(R_INFO)(symbol, type);
290 #ifdef TCC_TARGET_X86_64
291 rel->r_addend = 0;
292 #endif
293 }
294
295 /* put stab debug information */
296
297 ST_FUNC void put_stabs(const char *str, int type, int other, int desc,
298 unsigned long value)
299 {
300 Stab_Sym *sym;
301
302 sym = section_ptr_add(stab_section, sizeof(Stab_Sym));
303 if (str) {
304 sym->n_strx = put_elf_str(stabstr_section, str);
305 } else {
306 sym->n_strx = 0;
307 }
308 sym->n_type = type;
309 sym->n_other = other;
310 sym->n_desc = desc;
311 sym->n_value = value;
312 }
313
314 ST_FUNC void put_stabs_r(const char *str, int type, int other, int desc,
315 unsigned long value, Section *sec, int sym_index)
316 {
317 put_stabs(str, type, other, desc, value);
318 put_elf_reloc(symtab_section, stab_section,
319 stab_section->data_offset - sizeof(unsigned int),
320 R_DATA_32, sym_index);
321 }
322
323 ST_FUNC void put_stabn(int type, int other, int desc, int value)
324 {
325 put_stabs(NULL, type, other, desc, value);
326 }
327
328 ST_FUNC void put_stabd(int type, int other, int desc)
329 {
330 put_stabs(NULL, type, other, desc, 0);
331 }
332
333 /* In an ELF file symbol table, the local symbols must appear below
334 the global and weak ones. Since TCC cannot sort it while generating
335 the code, we must do it after. All the relocation tables are also
336 modified to take into account the symbol table sorting */
337 static void sort_syms(TCCState *s1, Section *s)
338 {
339 int *old_to_new_syms;
340 ElfW(Sym) *new_syms;
341 int nb_syms, i;
342 ElfW(Sym) *p, *q;
343 ElfW_Rel *rel, *rel_end;
344 Section *sr;
345 int type, sym_index;
346
347 nb_syms = s->data_offset / sizeof(ElfW(Sym));
348 new_syms = tcc_malloc(nb_syms * sizeof(ElfW(Sym)));
349 old_to_new_syms = tcc_malloc(nb_syms * sizeof(int));
350
351 /* first pass for local symbols */
352 p = (ElfW(Sym) *)s->data;
353 q = new_syms;
354 for(i = 0; i < nb_syms; i++) {
355 if (ELFW(ST_BIND)(p->st_info) == STB_LOCAL) {
356 old_to_new_syms[i] = q - new_syms;
357 *q++ = *p;
358 }
359 p++;
360 }
361 /* save the number of local symbols in section header */
362 s->sh_info = q - new_syms;
363
364 /* then second pass for non local symbols */
365 p = (ElfW(Sym) *)s->data;
366 for(i = 0; i < nb_syms; i++) {
367 if (ELFW(ST_BIND)(p->st_info) != STB_LOCAL) {
368 old_to_new_syms[i] = q - new_syms;
369 *q++ = *p;
370 }
371 p++;
372 }
373
374 /* we copy the new symbols to the old */
375 memcpy(s->data, new_syms, nb_syms * sizeof(ElfW(Sym)));
376 tcc_free(new_syms);
377
378 /* now we modify all the relocations */
379 for(i = 1; i < s1->nb_sections; i++) {
380 sr = s1->sections[i];
381 if (sr->sh_type == SHT_RELX && sr->link == s) {
382 rel_end = (ElfW_Rel *)(sr->data + sr->data_offset);
383 for(rel = (ElfW_Rel *)sr->data;
384 rel < rel_end;
385 rel++) {
386 sym_index = ELFW(R_SYM)(rel->r_info);
387 type = ELFW(R_TYPE)(rel->r_info);
388 sym_index = old_to_new_syms[sym_index];
389 rel->r_info = ELFW(R_INFO)(sym_index, type);
390 }
391 }
392 }
393
394 tcc_free(old_to_new_syms);
395 }
396
397 /* relocate common symbols in the .bss section */
398 ST_FUNC void relocate_common_syms(void)
399 {
400 ElfW(Sym) *sym, *sym_end;
401 unsigned long offset, align;
402
403 sym_end = (ElfW(Sym) *)(symtab_section->data + symtab_section->data_offset);
404 for(sym = (ElfW(Sym) *)symtab_section->data + 1;
405 sym < sym_end;
406 sym++) {
407 if (sym->st_shndx == SHN_COMMON) {
408 /* align symbol */
409 align = sym->st_value;
410 offset = bss_section->data_offset;
411 offset = (offset + align - 1) & -align;
412 sym->st_value = offset;
413 sym->st_shndx = bss_section->sh_num;
414 offset += sym->st_size;
415 bss_section->data_offset = offset;
416 }
417 }
418 }
419
420 /* relocate symbol table, resolve undefined symbols if do_resolve is
421 true and output error if undefined symbol. */
422 ST_FUNC void relocate_syms(TCCState *s1, int do_resolve)
423 {
424 ElfW(Sym) *sym, *esym, *sym_end;
425 int sym_bind, sh_num, sym_index;
426 const char *name;
427
428 sym_end = (ElfW(Sym) *)(symtab_section->data + symtab_section->data_offset);
429 for(sym = (ElfW(Sym) *)symtab_section->data + 1;
430 sym < sym_end;
431 sym++) {
432 sh_num = sym->st_shndx;
433 if (sh_num == SHN_UNDEF) {
434 name = strtab_section->data + sym->st_name;
435 if (do_resolve) {
436 #if defined TCC_IS_NATIVE && !defined _WIN32
437 void *addr;
438 name = symtab_section->link->data + sym->st_name;
439 addr = resolve_sym(s1, name);
440 if (addr) {
441 sym->st_value = (addr_t)addr;
442 goto found;
443 }
444 #endif
445 } else if (s1->dynsym) {
446 /* if dynamic symbol exist, then use it */
447 sym_index = find_elf_sym(s1->dynsym, name);
448 if (sym_index) {
449 esym = &((ElfW(Sym) *)s1->dynsym->data)[sym_index];
450 sym->st_value = esym->st_value;
451 goto found;
452 }
453 }
454 /* XXX: _fp_hw seems to be part of the ABI, so we ignore
455 it */
456 if (!strcmp(name, "_fp_hw"))
457 goto found;
458 /* only weak symbols are accepted to be undefined. Their
459 value is zero */
460 sym_bind = ELFW(ST_BIND)(sym->st_info);
461 if (sym_bind == STB_WEAK) {
462 sym->st_value = 0;
463 } else {
464 tcc_error_noabort("undefined symbol '%s'", name);
465 }
466 } else if (sh_num < SHN_LORESERVE) {
467 /* add section base */
468 sym->st_value += s1->sections[sym->st_shndx]->sh_addr;
469 }
470 found: ;
471 }
472 }
473
474 #ifdef TCC_HAS_RUNTIME_PLTGOT
475 #ifdef TCC_TARGET_X86_64
476 #define JMP_TABLE_ENTRY_SIZE 14
477 static addr_t add_jmp_table(TCCState *s1, addr_t val)
478 {
479 char *p = s1->runtime_plt_and_got + s1->runtime_plt_and_got_offset;
480 s1->runtime_plt_and_got_offset += JMP_TABLE_ENTRY_SIZE;
481 /* jmp *0x0(%rip) */
482 p[0] = 0xff;
483 p[1] = 0x25;
484 *(int *)(p + 2) = 0;
485 *(addr_t *)(p + 6) = val;
486 return (addr_t)p;
487 }
488
489 static addr_t add_got_table(TCCState *s1, addr_t val)
490 {
491 addr_t *p = (addr_t *)(s1->runtime_plt_and_got + s1->runtime_plt_and_got_offset);
492 s1->runtime_plt_and_got_offset += sizeof(addr_t);
493 *p = val;
494 return (addr_t)p;
495 }
496 #elif defined TCC_TARGET_ARM
497 #define JMP_TABLE_ENTRY_SIZE 8
498 static addr_t add_jmp_table(TCCState *s1, int val)
499 {
500 uint32_t *p = (uint32_t *)(s1->runtime_plt_and_got + s1->runtime_plt_and_got_offset);
501 s1->runtime_plt_and_got_offset += JMP_TABLE_ENTRY_SIZE;
502 /* ldr pc, [pc, #-4] */
503 p[0] = 0xE51FF004;
504 p[1] = val;
505 return (addr_t)p;
506 }
507 #endif
508 #endif /* def TCC_HAS_RUNTIME_PLTGOT */
509
510 /* relocate a given section (CPU dependent) */
511 ST_FUNC void relocate_section(TCCState *s1, Section *s)
512 {
513 Section *sr;
514 ElfW_Rel *rel, *rel_end, *qrel;
515 ElfW(Sym) *sym;
516 int type, sym_index;
517 unsigned char *ptr;
518 addr_t val, addr;
519 #if defined TCC_TARGET_I386 || defined TCC_TARGET_X86_64
520 int esym_index;
521 #endif
522
523 sr = s->reloc;
524 rel_end = (ElfW_Rel *)(sr->data + sr->data_offset);
525 qrel = (ElfW_Rel *)sr->data;
526 for(rel = qrel;
527 rel < rel_end;
528 rel++) {
529 ptr = s->data + rel->r_offset;
530
531 sym_index = ELFW(R_SYM)(rel->r_info);
532 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
533 val = sym->st_value;
534 #ifdef TCC_TARGET_X86_64
535 val += rel->r_addend;
536 #endif
537 type = ELFW(R_TYPE)(rel->r_info);
538 addr = s->sh_addr + rel->r_offset;
539
540 /* CPU specific */
541 switch(type) {
542 #if defined(TCC_TARGET_I386)
543 case R_386_32:
544 if (s1->output_type == TCC_OUTPUT_DLL) {
545 esym_index = s1->symtab_to_dynsym[sym_index];
546 qrel->r_offset = rel->r_offset;
547 if (esym_index) {
548 qrel->r_info = ELFW(R_INFO)(esym_index, R_386_32);
549 qrel++;
550 break;
551 } else {
552 qrel->r_info = ELFW(R_INFO)(0, R_386_RELATIVE);
553 qrel++;
554 }
555 }
556 *(int *)ptr += val;
557 break;
558 case R_386_PC32:
559 if (s1->output_type == TCC_OUTPUT_DLL) {
560 /* DLL relocation */
561 esym_index = s1->symtab_to_dynsym[sym_index];
562 if (esym_index) {
563 qrel->r_offset = rel->r_offset;
564 qrel->r_info = ELFW(R_INFO)(esym_index, R_386_PC32);
565 qrel++;
566 break;
567 }
568 }
569 *(int *)ptr += val - addr;
570 break;
571 case R_386_PLT32:
572 *(int *)ptr += val - addr;
573 break;
574 case R_386_GLOB_DAT:
575 case R_386_JMP_SLOT:
576 *(int *)ptr = val;
577 break;
578 case R_386_GOTPC:
579 *(int *)ptr += s1->got->sh_addr - addr;
580 break;
581 case R_386_GOTOFF:
582 *(int *)ptr += val - s1->got->sh_addr;
583 break;
584 case R_386_GOT32:
585 /* we load the got offset */
586 *(int *)ptr += s1->sym_attrs[sym_index].got_offset;
587 break;
588 case R_386_16:
589 if (s1->output_format != TCC_OUTPUT_FORMAT_BINARY) {
590 output_file:
591 tcc_error("can only produce 16-bit binary files");
592 }
593 *(short *)ptr += val;
594 break;
595 case R_386_PC16:
596 if (s1->output_format != TCC_OUTPUT_FORMAT_BINARY)
597 goto output_file;
598 *(short *)ptr += val - addr;
599 break;
600 #elif defined(TCC_TARGET_ARM)
601 case R_ARM_PC24:
602 case R_ARM_CALL:
603 case R_ARM_JUMP24:
604 case R_ARM_PLT32:
605 {
606 int x, is_thumb, is_call, h, blx_avail, is_bl, th_ko;
607 x = (*(int *) ptr) & 0xffffff;
608 (*(int *)ptr) &= 0xff000000;
609 if (x & 0x800000)
610 x -= 0x1000000;
611 x <<= 2;
612 blx_avail = (TCC_ARM_VERSION >= 5);
613 is_thumb = val & 1;
614 is_bl = (*(unsigned *) ptr) >> 24 == 0xeb;
615 is_call = (type == R_ARM_CALL || (type == R_ARM_PC24 && is_bl));
616 x += val - addr;
617 h = x & 2;
618 th_ko = (x & 3) && (!blx_avail || !is_call);
619 #ifdef TCC_HAS_RUNTIME_PLTGOT
620 if (s1->output_type == TCC_OUTPUT_MEMORY) {
621 if (th_ko || x >= 0x2000000 || x < -0x2000000) {
622 x += add_jmp_table(s1, val) - val; /* add veneer */
623 th_ko = (x & 3) && (!blx_avail || !is_call);
624 is_thumb = 0; /* Veneer uses ARM instructions */
625 }
626 }
627 #endif
628 if (th_ko || x >= 0x2000000 || x < -0x2000000)
629 tcc_error("can't relocate value at %x",addr);
630 x >>= 2;
631 x &= 0xffffff;
632 /* Only reached if blx is avail and it is a call */
633 if (is_thumb) {
634 x |= h << 24;
635 (*(int *)ptr) = 0xfa << 24; /* bl -> blx */
636 }
637 (*(int *) ptr) |= x;
638 }
639 break;
640 /* Since these relocations only concern Thumb-2 and blx instruction was
641 introduced before Thumb-2, we can assume blx is available and not
642 guard its use */
643 case R_ARM_THM_PC22:
644 case R_ARM_THM_JUMP24:
645 {
646 int x, hi, lo, s, j1, j2, i1, i2, imm10, imm11;
647 int to_thumb, is_call, to_plt, blx_bit = 1 << 12;
648 Section *plt;
649
650 /* weak reference */
651 if (sym->st_shndx == SHN_UNDEF &&
652 ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
653 break;
654
655 /* Get initial offset */
656 hi = (*(uint16_t *)ptr);
657 lo = (*(uint16_t *)(ptr+2));
658 s = (hi >> 10) & 1;
659 j1 = (lo >> 13) & 1;
660 j2 = (lo >> 11) & 1;
661 i1 = (j1 ^ s) ^ 1;
662 i2 = (j2 ^ s) ^ 1;
663 imm10 = hi & 0x3ff;
664 imm11 = lo & 0x7ff;
665 x = (s << 24) | (i1 << 23) | (i2 << 22) |
666 (imm10 << 12) | (imm11 << 1);
667 if (x & 0x01000000)
668 x -= 0x02000000;
669
670 /* Relocation infos */
671 to_thumb = val & 1;
672 plt = s1->plt;
673 to_plt = (val >= plt->sh_addr) &&
674 (val < plt->sh_addr + plt->data_offset);
675 is_call = (type == R_ARM_THM_PC22);
676
677 /* Compute final offset */
678 if (to_plt && !is_call) /* Point to 1st instr of Thumb stub */
679 x -= 4;
680 x += val - addr;
681 if (!to_thumb && is_call) {
682 blx_bit = 0; /* bl -> blx */
683 x = (x + 3) & -4; /* Compute offset from aligned PC */
684 }
685
686 /* Check that relocation is possible
687 * offset must not be out of range
688 * if target is to be entered in arm mode:
689 - bit 1 must not set
690 - instruction must be a call (bl) or a jump to PLT */
691 if (!to_thumb || x >= 0x1000000 || x < -0x1000000)
692 if (to_thumb || (val & 2) || (!is_call && !to_plt))
693 tcc_error("can't relocate value at %x",addr);
694
695 /* Compute and store final offset */
696 s = (x >> 24) & 1;
697 i1 = (x >> 23) & 1;
698 i2 = (x >> 22) & 1;
699 j1 = s ^ (i1 ^ 1);
700 j2 = s ^ (i2 ^ 1);
701 imm10 = (x >> 12) & 0x3ff;
702 imm11 = (x >> 1) & 0x7ff;
703 (*(uint16_t *)ptr) = (uint16_t) ((hi & 0xf800) |
704 (s << 10) | imm10);
705 (*(uint16_t *)(ptr+2)) = (uint16_t) ((lo & 0xc000) |
706 (j1 << 13) | blx_bit | (j2 << 11) |
707 imm11);
708 }
709 break;
710 case R_ARM_MOVT_ABS:
711 case R_ARM_MOVW_ABS_NC:
712 {
713 int x, imm4, imm12;
714 if (type == R_ARM_MOVT_ABS)
715 val >>= 16;
716 imm12 = val & 0xfff;
717 imm4 = (val >> 12) & 0xf;
718 x = (imm4 << 16) | imm12;
719 if (type == R_ARM_THM_MOVT_ABS)
720 *(int *)ptr |= x;
721 else
722 *(int *)ptr += x;
723 }
724 break;
725 case R_ARM_THM_MOVT_ABS:
726 case R_ARM_THM_MOVW_ABS_NC:
727 {
728 int x, i, imm4, imm3, imm8;
729 if (type == R_ARM_THM_MOVT_ABS)
730 val >>= 16;
731 imm8 = val & 0xff;
732 imm3 = (val >> 8) & 0x7;
733 i = (val >> 11) & 1;
734 imm4 = (val >> 12) & 0xf;
735 x = (imm3 << 28) | (imm8 << 16) | (i << 10) | imm4;
736 if (type == R_ARM_THM_MOVT_ABS)
737 *(int *)ptr |= x;
738 else
739 *(int *)ptr += x;
740 }
741 break;
742 case R_ARM_PREL31:
743 {
744 int x;
745 x = (*(int *)ptr) & 0x7fffffff;
746 (*(int *)ptr) &= 0x80000000;
747 x = (x * 2) / 2;
748 x += val - addr;
749 if((x^(x>>1))&0x40000000)
750 tcc_error("can't relocate value at %x",addr);
751 (*(int *)ptr) |= x & 0x7fffffff;
752 }
753 case R_ARM_ABS32:
754 *(int *)ptr += val;
755 break;
756 case R_ARM_REL32:
757 *(int *)ptr += val - addr;
758 break;
759 case R_ARM_GOTPC:
760 *(int *)ptr += s1->got->sh_addr - addr;
761 break;
762 case R_ARM_GOTOFF:
763 *(int *)ptr += val - s1->got->sh_addr;
764 break;
765 case R_ARM_GOT32:
766 /* we load the got offset */
767 *(int *)ptr += s1->sym_attrs[sym_index].got_offset;
768 break;
769 case R_ARM_COPY:
770 break;
771 case R_ARM_V4BX:
772 /* trade Thumb support for ARMv4 support */
773 if ((0x0ffffff0 & *(int*)ptr) == 0x012FFF10)
774 *(int*)ptr ^= 0xE12FFF10 ^ 0xE1A0F000; /* BX Rm -> MOV PC, Rm */
775 break;
776 default:
777 fprintf(stderr,"FIXME: handle reloc type %x at %x [%p] to %x\n",
778 type, (unsigned)addr, ptr, (unsigned)val);
779 break;
780 #elif defined(TCC_TARGET_C67)
781 case R_C60_32:
782 *(int *)ptr += val;
783 break;
784 case R_C60LO16:
785 {
786 uint32_t orig;
787
788 /* put the low 16 bits of the absolute address */
789 // add to what is already there
790
791 orig = ((*(int *)(ptr )) >> 7) & 0xffff;
792 orig |= (((*(int *)(ptr+4)) >> 7) & 0xffff) << 16;
793
794 //patch both at once - assumes always in pairs Low - High
795
796 *(int *) ptr = (*(int *) ptr & (~(0xffff << 7)) ) | (((val+orig) & 0xffff) << 7);
797 *(int *)(ptr+4) = (*(int *)(ptr+4) & (~(0xffff << 7)) ) | ((((val+orig)>>16) & 0xffff) << 7);
798 }
799 break;
800 case R_C60HI16:
801 break;
802 default:
803 fprintf(stderr,"FIXME: handle reloc type %x at %x [%p] to %x\n",
804 type, (unsigned)addr, ptr, (unsigned)val);
805 break;
806 #elif defined(TCC_TARGET_X86_64)
807 case R_X86_64_64:
808 if (s1->output_type == TCC_OUTPUT_DLL) {
809 qrel->r_info = ELFW(R_INFO)(0, R_X86_64_RELATIVE);
810 qrel->r_addend = *(long long *)ptr + val;
811 qrel++;
812 }
813 *(long long *)ptr += val;
814 break;
815 case R_X86_64_32:
816 case R_X86_64_32S:
817 if (s1->output_type == TCC_OUTPUT_DLL) {
818 /* XXX: this logic may depend on TCC's codegen
819 now TCC uses R_X86_64_32 even for a 64bit pointer */
820 qrel->r_info = ELFW(R_INFO)(0, R_X86_64_RELATIVE);
821 qrel->r_addend = *(int *)ptr + val;
822 qrel++;
823 }
824 *(int *)ptr += val;
825 break;
826
827 case R_X86_64_PC32:
828 if (s1->output_type == TCC_OUTPUT_DLL) {
829 /* DLL relocation */
830 esym_index = s1->symtab_to_dynsym[sym_index];
831 if (esym_index) {
832 qrel->r_offset = rel->r_offset;
833 qrel->r_info = ELFW(R_INFO)(esym_index, R_X86_64_PC32);
834 qrel->r_addend = *(int *)ptr;
835 qrel++;
836 break;
837 }
838 }
839 /* fall through */
840 case R_X86_64_PLT32: {
841 long long diff;
842 diff = (long long)val - addr;
843 if (diff <= -2147483647 || diff > 2147483647) {
844 #ifdef TCC_HAS_RUNTIME_PLTGOT
845 /* XXX: naive support for over 32bit jump */
846 if (s1->output_type == TCC_OUTPUT_MEMORY) {
847 val = (add_jmp_table(s1, val - rel->r_addend) +
848 rel->r_addend);
849 diff = val - addr;
850 }
851 #endif
852 if (diff <= -2147483647 || diff > 2147483647) {
853 tcc_error("internal error: relocation failed");
854 }
855 }
856 *(int *)ptr += diff;
857 }
858 break;
859 case R_X86_64_GLOB_DAT:
860 case R_X86_64_JUMP_SLOT:
861 /* They don't need addend */
862 *(int *)ptr = val - rel->r_addend;
863 break;
864 case R_X86_64_GOTPCREL:
865 #ifdef TCC_HAS_RUNTIME_PLTGOT
866 if (s1->output_type == TCC_OUTPUT_MEMORY) {
867 val = add_got_table(s1, val - rel->r_addend) + rel->r_addend;
868 *(int *)ptr += val - addr;
869 break;
870 }
871 #endif
872 *(int *)ptr += (s1->got->sh_addr - addr +
873 s1->sym_attrs[sym_index].got_offset - 4);
874 break;
875 case R_X86_64_GOTTPOFF:
876 *(int *)ptr += val - s1->got->sh_addr;
877 break;
878 case R_X86_64_GOT32:
879 /* we load the got offset */
880 *(int *)ptr += s1->sym_attrs[sym_index].got_offset;
881 break;
882 #else
883 #error unsupported processor
884 #endif
885 }
886 }
887 /* if the relocation is allocated, we change its symbol table */
888 if (sr->sh_flags & SHF_ALLOC)
889 sr->link = s1->dynsym;
890 }
891
892 /* relocate relocation table in 'sr' */
893 static void relocate_rel(TCCState *s1, Section *sr)
894 {
895 Section *s;
896 ElfW_Rel *rel, *rel_end;
897
898 s = s1->sections[sr->sh_info];
899 rel_end = (ElfW_Rel *)(sr->data + sr->data_offset);
900 for(rel = (ElfW_Rel *)sr->data;
901 rel < rel_end;
902 rel++) {
903 rel->r_offset += s->sh_addr;
904 }
905 }
906
907 /* count the number of dynamic relocations so that we can reserve
908 their space */
909 static int prepare_dynamic_rel(TCCState *s1, Section *sr)
910 {
911 ElfW_Rel *rel, *rel_end;
912 int sym_index, esym_index, type, count;
913
914 count = 0;
915 rel_end = (ElfW_Rel *)(sr->data + sr->data_offset);
916 for(rel = (ElfW_Rel *)sr->data; rel < rel_end; rel++) {
917 sym_index = ELFW(R_SYM)(rel->r_info);
918 type = ELFW(R_TYPE)(rel->r_info);
919 switch(type) {
920 #if defined(TCC_TARGET_I386)
921 case R_386_32:
922 #elif defined(TCC_TARGET_X86_64)
923 case R_X86_64_32:
924 case R_X86_64_32S:
925 case R_X86_64_64:
926 #endif
927 count++;
928 break;
929 #if defined(TCC_TARGET_I386)
930 case R_386_PC32:
931 #elif defined(TCC_TARGET_X86_64)
932 case R_X86_64_PC32:
933 #endif
934 esym_index = s1->symtab_to_dynsym[sym_index];
935 if (esym_index)
936 count++;
937 break;
938 default:
939 break;
940 }
941 }
942 if (count) {
943 /* allocate the section */
944 sr->sh_flags |= SHF_ALLOC;
945 sr->sh_size = count * sizeof(ElfW_Rel);
946 }
947 return count;
948 }
949
950 static struct sym_attr *alloc_sym_attr(TCCState *s1, int index)
951 {
952 int n;
953 struct sym_attr *tab;
954
955 if (index >= s1->nb_sym_attrs) {
956 /* find immediately bigger power of 2 and reallocate array */
957 n = 1;
958 while (index >= n)
959 n *= 2;
960 tab = tcc_realloc(s1->sym_attrs, n * sizeof(*s1->sym_attrs));
961 s1->sym_attrs = tab;
962 memset(s1->sym_attrs + s1->nb_sym_attrs, 0,
963 (n - s1->nb_sym_attrs) * sizeof(*s1->sym_attrs));
964 s1->nb_sym_attrs = n;
965 }
966 return &s1->sym_attrs[index];
967 }
968
969 /* XXX: suppress that */
970 static void put32(unsigned char *p, uint32_t val)
971 {
972 p[0] = val;
973 p[1] = val >> 8;
974 p[2] = val >> 16;
975 p[3] = val >> 24;
976 }
977
978 #if defined(TCC_TARGET_I386) || defined(TCC_TARGET_ARM) || \
979 defined(TCC_TARGET_X86_64)
980 static uint32_t get32(unsigned char *p)
981 {
982 return p[0] | (p[1] << 8) | (p[2] << 16) | (p[3] << 24);
983 }
984 #endif
985
986 static void build_got(TCCState *s1)
987 {
988 unsigned char *ptr;
989
990 /* if no got, then create it */
991 s1->got = new_section(s1, ".got", SHT_PROGBITS, SHF_ALLOC | SHF_WRITE);
992 s1->got->sh_entsize = 4;
993 add_elf_sym(symtab_section, 0, 4, ELFW(ST_INFO)(STB_GLOBAL, STT_OBJECT),
994 0, s1->got->sh_num, "_GLOBAL_OFFSET_TABLE_");
995 ptr = section_ptr_add(s1->got, 3 * PTR_SIZE);
996 #if PTR_SIZE == 4
997 /* keep space for _DYNAMIC pointer, if present */
998 put32(ptr, 0);
999 /* two dummy got entries */
1000 put32(ptr + 4, 0);
1001 put32(ptr + 8, 0);
1002 #else
1003 /* keep space for _DYNAMIC pointer, if present */
1004 put32(ptr, 0);
1005 put32(ptr + 4, 0);
1006 /* two dummy got entries */
1007 put32(ptr + 8, 0);
1008 put32(ptr + 12, 0);
1009 put32(ptr + 16, 0);
1010 put32(ptr + 20, 0);
1011 #endif
1012 }
1013
1014 /* put a got entry corresponding to a symbol in symtab_section. 'size'
1015 and 'info' can be modifed if more precise info comes from the DLL */
1016 static void put_got_entry(TCCState *s1,
1017 int reloc_type, unsigned long size, int info,
1018 int sym_index)
1019 {
1020 int index;
1021 const char *name;
1022 ElfW(Sym) *sym;
1023 unsigned long offset;
1024 int *ptr;
1025
1026 if (!s1->got)
1027 build_got(s1);
1028
1029 /* if a got entry already exists for that symbol, no need to add one */
1030 if (sym_index < s1->nb_sym_attrs &&
1031 s1->sym_attrs[sym_index].got_offset)
1032 return;
1033
1034 alloc_sym_attr(s1, sym_index)->got_offset = s1->got->data_offset;
1035
1036 if (s1->dynsym) {
1037 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1038 name = symtab_section->link->data + sym->st_name;
1039 offset = sym->st_value;
1040 #if defined(TCC_TARGET_I386) || defined(TCC_TARGET_X86_64)
1041 if (reloc_type ==
1042 #ifdef TCC_TARGET_X86_64
1043 R_X86_64_JUMP_SLOT
1044 #else
1045 R_386_JMP_SLOT
1046 #endif
1047 ) {
1048 Section *plt;
1049 uint8_t *p;
1050 int modrm;
1051
1052 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
1053 modrm = 0x25;
1054 #else
1055 /* if we build a DLL, we add a %ebx offset */
1056 if (s1->output_type == TCC_OUTPUT_DLL)
1057 modrm = 0xa3;
1058 else
1059 modrm = 0x25;
1060 #endif
1061
1062 /* add a PLT entry */
1063 plt = s1->plt;
1064 if (plt->data_offset == 0) {
1065 /* first plt entry */
1066 p = section_ptr_add(plt, 16);
1067 p[0] = 0xff; /* pushl got + PTR_SIZE */
1068 p[1] = modrm + 0x10;
1069 put32(p + 2, PTR_SIZE);
1070 p[6] = 0xff; /* jmp *(got + PTR_SIZE * 2) */
1071 p[7] = modrm;
1072 put32(p + 8, PTR_SIZE * 2);
1073 }
1074
1075 p = section_ptr_add(plt, 16);
1076 p[0] = 0xff; /* jmp *(got + x) */
1077 p[1] = modrm;
1078 put32(p + 2, s1->got->data_offset);
1079 p[6] = 0x68; /* push $xxx */
1080 put32(p + 7, (plt->data_offset - 32) >> 1);
1081 p[11] = 0xe9; /* jmp plt_start */
1082 put32(p + 12, -(plt->data_offset));
1083
1084 /* the symbol is modified so that it will be relocated to
1085 the PLT */
1086 #if !defined(TCC_OUTPUT_DLL_WITH_PLT)
1087 if (s1->output_type == TCC_OUTPUT_EXE)
1088 #endif
1089 offset = plt->data_offset - 16;
1090 }
1091 #elif defined(TCC_TARGET_ARM)
1092 if (reloc_type == R_ARM_JUMP_SLOT) {
1093 Section *plt;
1094 uint8_t *p;
1095
1096 /* if we build a DLL, we add a %ebx offset */
1097 if (s1->output_type == TCC_OUTPUT_DLL)
1098 tcc_error("DLLs unimplemented!");
1099
1100 /* add a PLT entry */
1101 plt = s1->plt;
1102 if (plt->data_offset == 0) {
1103 /* first plt entry */
1104 p = section_ptr_add(plt, 16);
1105 put32(p , 0xe52de004);
1106 put32(p + 4, 0xe59fe010);
1107 put32(p + 8, 0xe08fe00e);
1108 put32(p + 12, 0xe5bef008);
1109 }
1110
1111 if (s1->sym_attrs[sym_index].plt_thumb_stub) {
1112 p = section_ptr_add(plt, 20);
1113 put32(p , 0x4778); // bx pc
1114 put32(p+2, 0x46c0); // nop
1115 p += 4;
1116 } else
1117 p = section_ptr_add(plt, 16);
1118 put32(p , 0xe59fc004); // ldr ip, [pc, #4] // offset in GOT
1119 put32(p+4, 0xe08fc00c); // add ip, pc, ip // absolute address or offset
1120 put32(p+8, 0xe59cf000); // ldr pc, [ip] // load absolute address or load offset
1121 put32(p+12, s1->got->data_offset);
1122
1123 /* the symbol is modified so that it will be relocated to
1124 the PLT */
1125 if (s1->output_type == TCC_OUTPUT_EXE)
1126 offset = plt->data_offset - 16;
1127 }
1128 #elif defined(TCC_TARGET_C67)
1129 tcc_error("C67 got not implemented");
1130 #else
1131 #error unsupported CPU
1132 #endif
1133 index = put_elf_sym(s1->dynsym, offset,
1134 size, info, 0, sym->st_shndx, name);
1135 /* put a got entry */
1136 put_elf_reloc(s1->dynsym, s1->got,
1137 s1->got->data_offset,
1138 reloc_type, index);
1139 }
1140 ptr = section_ptr_add(s1->got, PTR_SIZE);
1141 *ptr = 0;
1142 }
1143
1144 /* build GOT and PLT entries */
1145 ST_FUNC void build_got_entries(TCCState *s1)
1146 {
1147 Section *s;
1148 ElfW_Rel *rel, *rel_end;
1149 ElfW(Sym) *sym;
1150 int i, type, reloc_type, sym_index;
1151
1152 for(i = 1; i < s1->nb_sections; i++) {
1153 s = s1->sections[i];
1154 if (s->sh_type != SHT_RELX)
1155 continue;
1156 /* no need to handle got relocations */
1157 if (s->link != symtab_section)
1158 continue;
1159 rel_end = (ElfW_Rel *)(s->data + s->data_offset);
1160 for(rel = (ElfW_Rel *)s->data;
1161 rel < rel_end;
1162 rel++) {
1163 type = ELFW(R_TYPE)(rel->r_info);
1164 switch(type) {
1165 #if defined(TCC_TARGET_I386)
1166 case R_386_GOT32:
1167 case R_386_GOTOFF:
1168 case R_386_GOTPC:
1169 case R_386_PLT32:
1170 if (!s1->got)
1171 build_got(s1);
1172 if (type == R_386_GOT32 || type == R_386_PLT32) {
1173 sym_index = ELFW(R_SYM)(rel->r_info);
1174 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1175 /* look at the symbol got offset. If none, then add one */
1176 if (type == R_386_GOT32)
1177 reloc_type = R_386_GLOB_DAT;
1178 else
1179 reloc_type = R_386_JMP_SLOT;
1180 put_got_entry(s1, reloc_type, sym->st_size, sym->st_info,
1181 sym_index);
1182 }
1183 break;
1184 #elif defined(TCC_TARGET_ARM)
1185 case R_ARM_GOT32:
1186 case R_ARM_GOTOFF:
1187 case R_ARM_GOTPC:
1188 case R_ARM_PLT32:
1189 if (!s1->got)
1190 build_got(s1);
1191 if (type == R_ARM_GOT32 || type == R_ARM_PLT32) {
1192 sym_index = ELFW(R_SYM)(rel->r_info);
1193 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1194 /* look at the symbol got offset. If none, then add one */
1195 if (type == R_ARM_GOT32)
1196 reloc_type = R_ARM_GLOB_DAT;
1197 else
1198 reloc_type = R_ARM_JUMP_SLOT;
1199 put_got_entry(s1, reloc_type, sym->st_size, sym->st_info,
1200 sym_index);
1201 }
1202 break;
1203 #elif defined(TCC_TARGET_C67)
1204 case R_C60_GOT32:
1205 case R_C60_GOTOFF:
1206 case R_C60_GOTPC:
1207 case R_C60_PLT32:
1208 if (!s1->got)
1209 build_got(s1);
1210 if (type == R_C60_GOT32 || type == R_C60_PLT32) {
1211 sym_index = ELFW(R_SYM)(rel->r_info);
1212 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1213 /* look at the symbol got offset. If none, then add one */
1214 if (type == R_C60_GOT32)
1215 reloc_type = R_C60_GLOB_DAT;
1216 else
1217 reloc_type = R_C60_JMP_SLOT;
1218 put_got_entry(s1, reloc_type, sym->st_size, sym->st_info,
1219 sym_index);
1220 }
1221 break;
1222 #elif defined(TCC_TARGET_X86_64)
1223 case R_X86_64_GOT32:
1224 case R_X86_64_GOTTPOFF:
1225 case R_X86_64_GOTPCREL:
1226 case R_X86_64_PLT32:
1227 if (!s1->got)
1228 build_got(s1);
1229 if (type == R_X86_64_GOT32 || type == R_X86_64_GOTPCREL ||
1230 type == R_X86_64_PLT32) {
1231 sym_index = ELFW(R_SYM)(rel->r_info);
1232 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1233 /* look at the symbol got offset. If none, then add one */
1234 if (type == R_X86_64_GOT32 || type == R_X86_64_GOTPCREL)
1235 reloc_type = R_X86_64_GLOB_DAT;
1236 else
1237 reloc_type = R_X86_64_JUMP_SLOT;
1238 put_got_entry(s1, reloc_type, sym->st_size, sym->st_info,
1239 sym_index);
1240 }
1241 break;
1242 #else
1243 #error unsupported CPU
1244 #endif
1245 default:
1246 break;
1247 }
1248 }
1249 }
1250 }
1251
1252 ST_FUNC Section *new_symtab(TCCState *s1,
1253 const char *symtab_name, int sh_type, int sh_flags,
1254 const char *strtab_name,
1255 const char *hash_name, int hash_sh_flags)
1256 {
1257 Section *symtab, *strtab, *hash;
1258 int *ptr, nb_buckets;
1259
1260 symtab = new_section(s1, symtab_name, sh_type, sh_flags);
1261 symtab->sh_entsize = sizeof(ElfW(Sym));
1262 strtab = new_section(s1, strtab_name, SHT_STRTAB, sh_flags);
1263 put_elf_str(strtab, "");
1264 symtab->link = strtab;
1265 put_elf_sym(symtab, 0, 0, 0, 0, 0, NULL);
1266
1267 nb_buckets = 1;
1268
1269 hash = new_section(s1, hash_name, SHT_HASH, hash_sh_flags);
1270 hash->sh_entsize = sizeof(int);
1271 symtab->hash = hash;
1272 hash->link = symtab;
1273
1274 ptr = section_ptr_add(hash, (2 + nb_buckets + 1) * sizeof(int));
1275 ptr[0] = nb_buckets;
1276 ptr[1] = 1;
1277 memset(ptr + 2, 0, (nb_buckets + 1) * sizeof(int));
1278 return symtab;
1279 }
1280
1281 /* put dynamic tag */
1282 static void put_dt(Section *dynamic, int dt, addr_t val)
1283 {
1284 ElfW(Dyn) *dyn;
1285 dyn = section_ptr_add(dynamic, sizeof(ElfW(Dyn)));
1286 dyn->d_tag = dt;
1287 dyn->d_un.d_val = val;
1288 }
1289
1290 static void add_init_array_defines(TCCState *s1, const char *section_name)
1291 {
1292 Section *s;
1293 long end_offset;
1294 char sym_start[1024];
1295 char sym_end[1024];
1296
1297 snprintf(sym_start, sizeof(sym_start), "__%s_start", section_name + 1);
1298 snprintf(sym_end, sizeof(sym_end), "__%s_end", section_name + 1);
1299
1300 s = find_section(s1, section_name);
1301 if (!s) {
1302 end_offset = 0;
1303 s = data_section;
1304 } else {
1305 end_offset = s->data_offset;
1306 }
1307
1308 add_elf_sym(symtab_section,
1309 0, 0,
1310 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1311 s->sh_num, sym_start);
1312 add_elf_sym(symtab_section,
1313 end_offset, 0,
1314 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1315 s->sh_num, sym_end);
1316 }
1317
1318 ST_FUNC void tcc_add_bcheck(TCCState *s1)
1319 {
1320 #ifdef CONFIG_TCC_BCHECK
1321 unsigned long *ptr;
1322 Section *init_section;
1323 unsigned char *pinit;
1324 int sym_index;
1325
1326 if (0 == s1->do_bounds_check)
1327 return;
1328
1329 /* XXX: add an object file to do that */
1330 ptr = section_ptr_add(bounds_section, sizeof(unsigned long));
1331 *ptr = 0;
1332 add_elf_sym(symtab_section, 0, 0,
1333 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1334 bounds_section->sh_num, "__bounds_start");
1335 #ifdef TCC_TARGET_I386
1336 if (s1->output_type != TCC_OUTPUT_MEMORY) {
1337 /* add 'call __bound_init()' in .init section */
1338 init_section = find_section(s1, ".init");
1339 pinit = section_ptr_add(init_section, 5);
1340 pinit[0] = 0xe8;
1341 put32(pinit + 1, -4);
1342 sym_index = find_elf_sym(symtab_section, "__bound_init");
1343 put_elf_reloc(symtab_section, init_section,
1344 init_section->data_offset - 4, R_386_PC32, sym_index);
1345 }
1346 #endif
1347 #endif
1348 }
1349
1350 static inline int tcc_add_support(TCCState *s1, const char *filename)
1351 {
1352 char buf[1024];
1353 snprintf(buf, sizeof(buf), "%s/%s", s1->tcc_lib_path, filename);
1354 return tcc_add_file(s1, buf);
1355 }
1356
1357 /* add tcc runtime libraries */
1358 ST_FUNC void tcc_add_runtime(TCCState *s1)
1359 {
1360 tcc_add_bcheck(s1);
1361
1362 /* add libc */
1363 if (!s1->nostdlib) {
1364 tcc_add_library(s1, "c");
1365 #ifdef CONFIG_USE_LIBGCC
1366 if (!s1->static_link)
1367 tcc_add_file(s1, TCC_LIBGCC);
1368 else
1369 tcc_add_support(s1, "libtcc1.a");
1370 #else
1371 tcc_add_support(s1, "libtcc1.a");
1372 #endif
1373 /* add crt end if not memory output */
1374 if (s1->output_type != TCC_OUTPUT_MEMORY)
1375 tcc_add_crt(s1, "crtn.o");
1376 }
1377 }
1378
1379 /* add various standard linker symbols (must be done after the
1380 sections are filled (for example after allocating common
1381 symbols)) */
1382 ST_FUNC void tcc_add_linker_symbols(TCCState *s1)
1383 {
1384 char buf[1024];
1385 int i;
1386 Section *s;
1387
1388 add_elf_sym(symtab_section,
1389 text_section->data_offset, 0,
1390 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1391 text_section->sh_num, "_etext");
1392 add_elf_sym(symtab_section,
1393 data_section->data_offset, 0,
1394 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1395 data_section->sh_num, "_edata");
1396 add_elf_sym(symtab_section,
1397 bss_section->data_offset, 0,
1398 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1399 bss_section->sh_num, "_end");
1400 /* horrible new standard ldscript defines */
1401 add_init_array_defines(s1, ".preinit_array");
1402 add_init_array_defines(s1, ".init_array");
1403 add_init_array_defines(s1, ".fini_array");
1404
1405 /* add start and stop symbols for sections whose name can be
1406 expressed in C */
1407 for(i = 1; i < s1->nb_sections; i++) {
1408 s = s1->sections[i];
1409 if (s->sh_type == SHT_PROGBITS &&
1410 (s->sh_flags & SHF_ALLOC)) {
1411 const char *p;
1412 int ch;
1413
1414 /* check if section name can be expressed in C */
1415 p = s->name;
1416 for(;;) {
1417 ch = *p;
1418 if (!ch)
1419 break;
1420 if (!isid(ch) && !isnum(ch))
1421 goto next_sec;
1422 p++;
1423 }
1424 snprintf(buf, sizeof(buf), "__start_%s", s->name);
1425 add_elf_sym(symtab_section,
1426 0, 0,
1427 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1428 s->sh_num, buf);
1429 snprintf(buf, sizeof(buf), "__stop_%s", s->name);
1430 add_elf_sym(symtab_section,
1431 s->data_offset, 0,
1432 ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
1433 s->sh_num, buf);
1434 }
1435 next_sec: ;
1436 }
1437 }
1438
1439 static void tcc_output_binary(TCCState *s1, FILE *f,
1440 const int *section_order)
1441 {
1442 Section *s;
1443 int i, offset, size;
1444
1445 offset = 0;
1446 for(i=1;i<s1->nb_sections;i++) {
1447 s = s1->sections[section_order[i]];
1448 if (s->sh_type != SHT_NOBITS &&
1449 (s->sh_flags & SHF_ALLOC)) {
1450 while (offset < s->sh_offset) {
1451 fputc(0, f);
1452 offset++;
1453 }
1454 size = s->sh_size;
1455 fwrite(s->data, 1, size, f);
1456 offset += size;
1457 }
1458 }
1459 }
1460
1461 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1462 #define HAVE_PHDR 1
1463 #define EXTRA_RELITEMS 14
1464
1465 /* move the relocation value from .dynsym to .got */
1466 void patch_dynsym_undef(TCCState *s1, Section *s)
1467 {
1468 uint32_t *gotd = (void *)s1->got->data;
1469 ElfW(Sym) *sym, *sym_end;
1470
1471 gotd += 3; // dummy entries in .got
1472 /* relocate symbols in .dynsym */
1473 sym_end = (ElfW(Sym) *)(s->data + s->data_offset);
1474 for (sym = (ElfW(Sym) *)s->data + 1; sym < sym_end; sym++) {
1475 if (sym->st_shndx == SHN_UNDEF) {
1476 *gotd++ = sym->st_value + 6; // XXX 6 is magic ?
1477 sym->st_value = 0;
1478 }
1479 }
1480 }
1481 #else
1482 #define HAVE_PHDR 0
1483 #define EXTRA_RELITEMS 9
1484
1485 /* zero plt offsets of weak symbols in .dynsym */
1486 void patch_dynsym_undef(TCCState *s1, Section *s)
1487 {
1488 ElfW(Sym) *sym, *sym_end;
1489
1490 sym_end = (ElfW(Sym) *)(s->data + s->data_offset);
1491 for (sym = (ElfW(Sym) *)s->data + 1; sym < sym_end; sym++)
1492 if (sym->st_shndx == SHN_UNDEF && ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
1493 sym->st_value = 0;
1494 }
1495 #endif
1496
1497 ST_FUNC void fill_got_entry(TCCState *s1, ElfW_Rel *rel)
1498 {
1499 int sym_index = ELFW(R_SYM) (rel->r_info);
1500 ElfW(Sym) *sym = &((ElfW(Sym) *) symtab_section->data)[sym_index];
1501 unsigned long offset;
1502
1503 if (sym_index >= s1->nb_sym_attrs)
1504 return;
1505 offset = s1->sym_attrs[sym_index].got_offset;
1506 section_reserve(s1->got, offset + PTR_SIZE);
1507 #ifdef TCC_TARGET_X86_64
1508 /* only works for x86-64 */
1509 put32(s1->got->data + offset + 4, sym->st_value >> 32);
1510 #endif
1511 put32(s1->got->data + offset, sym->st_value & 0xffffffff);
1512 }
1513
1514 ST_FUNC void fill_got(TCCState *s1)
1515 {
1516 Section *s;
1517 ElfW_Rel *rel, *rel_end;
1518 int i;
1519
1520 for(i = 1; i < s1->nb_sections; i++) {
1521 s = s1->sections[i];
1522 if (s->sh_type != SHT_RELX)
1523 continue;
1524 /* no need to handle got relocations */
1525 if (s->link != symtab_section)
1526 continue;
1527 rel_end = (ElfW_Rel *) (s->data + s->data_offset);
1528 for(rel = (ElfW_Rel *) s->data; rel < rel_end; rel++) {
1529 switch (ELFW(R_TYPE) (rel->r_info)) {
1530 case R_X86_64_GOT32:
1531 case R_X86_64_GOTPCREL:
1532 case R_X86_64_PLT32:
1533 fill_got_entry(s1, rel);
1534 break;
1535 }
1536 }
1537 }
1538 }
1539
1540
1541 /* output an ELF file */
1542 /* XXX: suppress unneeded sections */
1543 static int elf_output_file(TCCState *s1, const char *filename)
1544 {
1545 ElfW(Ehdr) ehdr;
1546 FILE *f;
1547 int fd, mode, ret;
1548 int *section_order;
1549 int shnum, i, phnum, file_offset, offset, size, j, sh_order_index, k;
1550 long long tmp;
1551 addr_t addr;
1552 Section *strsec, *s;
1553 ElfW(Shdr) shdr, *sh;
1554 ElfW(Phdr) *phdr, *ph;
1555 Section *interp, *dynamic, *dynstr;
1556 unsigned long saved_dynamic_data_offset;
1557 ElfW(Sym) *sym;
1558 int type, file_type;
1559 addr_t rel_addr, rel_size;
1560 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1561 addr_t bss_addr, bss_size;
1562 #endif
1563
1564 file_type = s1->output_type;
1565 s1->nb_errors = 0;
1566
1567 if (file_type != TCC_OUTPUT_OBJ) {
1568 tcc_add_runtime(s1);
1569 }
1570
1571 phdr = NULL;
1572 section_order = NULL;
1573 interp = NULL;
1574 dynamic = NULL;
1575 dynstr = NULL; /* avoid warning */
1576 saved_dynamic_data_offset = 0; /* avoid warning */
1577
1578 if (file_type != TCC_OUTPUT_OBJ) {
1579 relocate_common_syms();
1580
1581 tcc_add_linker_symbols(s1);
1582
1583 if (!s1->static_link) {
1584 const char *name;
1585 int sym_index, index;
1586 ElfW(Sym) *esym, *sym_end;
1587
1588 if (file_type == TCC_OUTPUT_EXE) {
1589 char *ptr;
1590 /* allow override the dynamic loader */
1591 const char *elfint = getenv("LD_SO");
1592 if (elfint == NULL)
1593 elfint = DEFAULT_ELFINTERP(s1);
1594 /* add interpreter section only if executable */
1595 interp = new_section(s1, ".interp", SHT_PROGBITS, SHF_ALLOC);
1596 interp->sh_addralign = 1;
1597 ptr = section_ptr_add(interp, 1+strlen(elfint));
1598 strcpy(ptr, elfint);
1599 }
1600
1601 /* add dynamic symbol table */
1602 s1->dynsym = new_symtab(s1, ".dynsym", SHT_DYNSYM, SHF_ALLOC,
1603 ".dynstr",
1604 ".hash", SHF_ALLOC);
1605 dynstr = s1->dynsym->link;
1606
1607 /* add dynamic section */
1608 dynamic = new_section(s1, ".dynamic", SHT_DYNAMIC,
1609 SHF_ALLOC | SHF_WRITE);
1610 dynamic->link = dynstr;
1611 dynamic->sh_entsize = sizeof(ElfW(Dyn));
1612
1613 /* add PLT */
1614 s1->plt = new_section(s1, ".plt", SHT_PROGBITS,
1615 SHF_ALLOC | SHF_EXECINSTR);
1616 s1->plt->sh_entsize = 4;
1617
1618 build_got(s1);
1619
1620 /* scan for undefined symbols and see if they are in the
1621 dynamic symbols. If a symbol STT_FUNC or STT_GNU_IFUNC
1622 is found, then we add it in the PLT. If a symbol
1623 STT_OBJECT is found, we add it in the .bss section with
1624 a suitable relocation */
1625 sym_end = (ElfW(Sym) *)(symtab_section->data +
1626 symtab_section->data_offset);
1627 if (file_type == TCC_OUTPUT_EXE) {
1628 for(sym = (ElfW(Sym) *)symtab_section->data + 1;
1629 sym < sym_end;
1630 sym++) {
1631 if (sym->st_shndx == SHN_UNDEF) {
1632 name = symtab_section->link->data + sym->st_name;
1633 sym_index = find_elf_sym(s1->dynsymtab_section, name);
1634 if (sym_index) {
1635 esym = &((ElfW(Sym) *)s1->dynsymtab_section->data)[sym_index];
1636 type = ELFW(ST_TYPE)(esym->st_info);
1637 if ((type == STT_FUNC) || (type == STT_GNU_IFUNC)) {
1638 /* Indirect functions shall have STT_FUNC type
1639 * in executable dynsym section. Indeed, a dlsym
1640 * call following a lazy resolution would pick
1641 * the symbol value from the executable dynsym
1642 * entry which would contain the address of the
1643 * function wanted by the caller of dlsym
1644 * instead of the address of the function that
1645 * would return that address */
1646 put_got_entry(s1, R_JMP_SLOT, esym->st_size,
1647 ELFW(ST_INFO)(STB_GLOBAL,STT_FUNC),
1648 sym - (ElfW(Sym) *)symtab_section->data);
1649 } else if (type == STT_OBJECT) {
1650 unsigned long offset;
1651 ElfW(Sym) *dynsym, *dynsym_end;
1652 offset = bss_section->data_offset;
1653 /* XXX: which alignment ? */
1654 offset = (offset + 16 - 1) & -16;
1655 index = put_elf_sym(s1->dynsym, offset, esym->st_size,
1656 esym->st_info, 0,
1657 bss_section->sh_num, name);
1658 // Ensure R_COPY works for weak symbol aliases
1659 if (ELFW(ST_BIND)(esym->st_info) == STB_WEAK) {
1660 dynsym_end = (ElfW(Sym) *)
1661 (s1->dynsymtab_section->data +
1662 s1->dynsymtab_section->data_offset);
1663 for(dynsym = (ElfW(Sym) *)s1->dynsymtab_section->data + 1;
1664 dynsym < dynsym_end; dynsym++) {
1665 if ((dynsym->st_value == esym->st_value)
1666 && (ELFW(ST_BIND)(dynsym->st_info) == STB_GLOBAL)) {
1667 char *dynname;
1668 dynname = s1->dynsymtab_section->link->data
1669 + dynsym->st_name;
1670 put_elf_sym(s1->dynsym, offset,
1671 dynsym->st_size,
1672 dynsym->st_info, 0,
1673 bss_section->sh_num,
1674 dynname);
1675 break;
1676 }
1677 }
1678 }
1679 put_elf_reloc(s1->dynsym, bss_section,
1680 offset, R_COPY, index);
1681 offset += esym->st_size;
1682 bss_section->data_offset = offset;
1683 }
1684 } else {
1685 /* STB_WEAK undefined symbols are accepted */
1686 /* XXX: _fp_hw seems to be part of the ABI, so we ignore
1687 it */
1688 if (ELFW(ST_BIND)(sym->st_info) == STB_WEAK ||
1689 !strcmp(name, "_fp_hw")) {
1690 } else {
1691 tcc_error_noabort("undefined symbol '%s'", name);
1692 }
1693 }
1694 } else if (s1->rdynamic &&
1695 ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
1696 /* if -rdynamic option, then export all non
1697 local symbols */
1698 name = symtab_section->link->data + sym->st_name;
1699 put_elf_sym(s1->dynsym, sym->st_value, sym->st_size,
1700 sym->st_info, 0,
1701 sym->st_shndx, name);
1702 }
1703 }
1704
1705 if (s1->nb_errors)
1706 goto fail;
1707
1708 /* now look at unresolved dynamic symbols and export
1709 corresponding symbol */
1710 sym_end = (ElfW(Sym) *)(s1->dynsymtab_section->data +
1711 s1->dynsymtab_section->data_offset);
1712 for(esym = (ElfW(Sym) *)s1->dynsymtab_section->data + 1;
1713 esym < sym_end;
1714 esym++) {
1715 if (esym->st_shndx == SHN_UNDEF) {
1716 name = s1->dynsymtab_section->link->data + esym->st_name;
1717 sym_index = find_elf_sym(symtab_section, name);
1718 if (sym_index) {
1719 /* XXX: avoid adding a symbol if already
1720 present because of -rdynamic ? */
1721 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
1722 put_elf_sym(s1->dynsym, sym->st_value, sym->st_size,
1723 sym->st_info, 0,
1724 sym->st_shndx, name);
1725 } else {
1726 if (ELFW(ST_BIND)(esym->st_info) == STB_WEAK) {
1727 /* weak symbols can stay undefined */
1728 } else {
1729 tcc_warning("undefined dynamic symbol '%s'", name);
1730 }
1731 }
1732 }
1733 }
1734 } else {
1735 int nb_syms;
1736 /* shared library case : we simply export all the global symbols */
1737 nb_syms = symtab_section->data_offset / sizeof(ElfW(Sym));
1738 s1->symtab_to_dynsym = tcc_mallocz(sizeof(int) * nb_syms);
1739 for(sym = (ElfW(Sym) *)symtab_section->data + 1;
1740 sym < sym_end;
1741 sym++) {
1742 if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
1743 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
1744 if ((ELFW(ST_TYPE)(sym->st_info) == STT_FUNC ||
1745 ELFW(ST_TYPE)(sym->st_info) == STT_GNU_IFUNC)
1746 && sym->st_shndx == SHN_UNDEF) {
1747 int visibility = ELFW(ST_BIND)(sym->st_info);
1748 put_got_entry(s1, R_JMP_SLOT, sym->st_size,
1749 ELFW(ST_INFO)(visibility,STT_FUNC),
1750 sym - (ElfW(Sym) *)symtab_section->data);
1751 }
1752 else if (ELFW(ST_TYPE)(sym->st_info) == STT_OBJECT) {
1753 put_got_entry(s1, R_X86_64_GLOB_DAT, sym->st_size,
1754 sym->st_info,
1755 sym - (ElfW(Sym) *)symtab_section->data);
1756 }
1757 else
1758 #endif
1759 {
1760 name = symtab_section->link->data + sym->st_name;
1761 index = put_elf_sym(s1->dynsym, sym->st_value, sym->st_size,
1762 sym->st_info, 0,
1763 sym->st_shndx, name);
1764 s1->symtab_to_dynsym[sym -
1765 (ElfW(Sym) *)symtab_section->data] =
1766 index;
1767 }
1768 }
1769 }
1770 }
1771
1772 build_got_entries(s1);
1773
1774 /* add a list of needed dlls */
1775 for(i = 0; i < s1->nb_loaded_dlls; i++) {
1776 DLLReference *dllref = s1->loaded_dlls[i];
1777 if (dllref->level == 0)
1778 put_dt(dynamic, DT_NEEDED, put_elf_str(dynstr, dllref->name));
1779 }
1780
1781 if (s1->rpath)
1782 put_dt(dynamic, DT_RPATH, put_elf_str(dynstr, s1->rpath));
1783
1784 /* XXX: currently, since we do not handle PIC code, we
1785 must relocate the readonly segments */
1786 if (file_type == TCC_OUTPUT_DLL) {
1787 if (s1->soname)
1788 put_dt(dynamic, DT_SONAME, put_elf_str(dynstr, s1->soname));
1789 put_dt(dynamic, DT_TEXTREL, 0);
1790 }
1791
1792 if (s1->symbolic)
1793 put_dt(dynamic, DT_SYMBOLIC, 0);
1794
1795 /* add necessary space for other entries */
1796 saved_dynamic_data_offset = dynamic->data_offset;
1797 dynamic->data_offset += sizeof(ElfW(Dyn)) * EXTRA_RELITEMS;
1798 } else {
1799 /* still need to build got entries in case of static link */
1800 build_got_entries(s1);
1801 }
1802 }
1803
1804 memset(&ehdr, 0, sizeof(ehdr));
1805
1806 /* we add a section for symbols */
1807 strsec = new_section(s1, ".shstrtab", SHT_STRTAB, 0);
1808 put_elf_str(strsec, "");
1809
1810 /* compute number of sections */
1811 shnum = s1->nb_sections;
1812
1813 /* this array is used to reorder sections in the output file */
1814 section_order = tcc_malloc(sizeof(int) * shnum);
1815 section_order[0] = 0;
1816 sh_order_index = 1;
1817
1818 /* compute number of program headers */
1819 switch(file_type) {
1820 default:
1821 case TCC_OUTPUT_OBJ:
1822 phnum = 0;
1823 break;
1824 case TCC_OUTPUT_EXE:
1825 if (!s1->static_link)
1826 phnum = 4 + HAVE_PHDR;
1827 else
1828 phnum = 2;
1829 break;
1830 case TCC_OUTPUT_DLL:
1831 phnum = 3;
1832 break;
1833 }
1834
1835 /* allocate strings for section names and decide if an unallocated
1836 section should be output */
1837 /* NOTE: the strsec section comes last, so its size is also
1838 correct ! */
1839 for(i = 1; i < s1->nb_sections; i++) {
1840 s = s1->sections[i];
1841 s->sh_name = put_elf_str(strsec, s->name);
1842 #if 0 /* gr */
1843 printf("section: f=%08x t=%08x i=%08x %s %s\n",
1844 s->sh_flags,
1845 s->sh_type,
1846 s->sh_info,
1847 s->name,
1848 s->reloc ? s->reloc->name : "n"
1849 );
1850 #endif
1851 /* when generating a DLL, we include relocations but we may
1852 patch them */
1853 if (file_type == TCC_OUTPUT_DLL &&
1854 s->sh_type == SHT_RELX &&
1855 !(s->sh_flags & SHF_ALLOC)) {
1856 /* //gr: avoid bogus relocs for empty (debug) sections */
1857 if (s1->sections[s->sh_info]->sh_flags & SHF_ALLOC)
1858 prepare_dynamic_rel(s1, s);
1859 else if (s1->do_debug)
1860 s->sh_size = s->data_offset;
1861 } else if (s1->do_debug ||
1862 file_type == TCC_OUTPUT_OBJ ||
1863 (s->sh_flags & SHF_ALLOC) ||
1864 i == (s1->nb_sections - 1)) {
1865 /* we output all sections if debug or object file */
1866 s->sh_size = s->data_offset;
1867 }
1868 }
1869
1870 /* allocate program segment headers */
1871 phdr = tcc_mallocz(phnum * sizeof(ElfW(Phdr)));
1872
1873 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF) {
1874 file_offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr));
1875 } else {
1876 file_offset = 0;
1877 }
1878 if (phnum > 0) {
1879 /* compute section to program header mapping */
1880 if (s1->has_text_addr) {
1881 int a_offset, p_offset;
1882 addr = s1->text_addr;
1883 /* we ensure that (addr % ELF_PAGE_SIZE) == file_offset %
1884 ELF_PAGE_SIZE */
1885 a_offset = (int) (addr & (s1->section_align - 1));
1886 p_offset = file_offset & (s1->section_align - 1);
1887 if (a_offset < p_offset)
1888 a_offset += s1->section_align;
1889 file_offset += (a_offset - p_offset);
1890 } else {
1891 if (file_type == TCC_OUTPUT_DLL)
1892 addr = 0;
1893 else
1894 addr = ELF_START_ADDR;
1895 /* compute address after headers */
1896 addr += (file_offset & (s1->section_align - 1));
1897 }
1898
1899 /* dynamic relocation table information, for .dynamic section */
1900 rel_size = 0;
1901 rel_addr = 0;
1902
1903 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1904 bss_addr = bss_size = 0;
1905 #endif
1906 /* leave one program header for the program interpreter */
1907 ph = &phdr[0];
1908 if (interp)
1909 ph += 1 + HAVE_PHDR;
1910
1911 for(j = 0; j < 2; j++) {
1912 ph->p_type = PT_LOAD;
1913 if (j == 0)
1914 ph->p_flags = PF_R | PF_X;
1915 else
1916 ph->p_flags = PF_R | PF_W;
1917 ph->p_align = s1->section_align;
1918
1919 /* we do the following ordering: interp, symbol tables,
1920 relocations, progbits, nobits */
1921 /* XXX: do faster and simpler sorting */
1922 for(k = 0; k < 5; k++) {
1923 for(i = 1; i < s1->nb_sections; i++) {
1924 s = s1->sections[i];
1925 /* compute if section should be included */
1926 if (j == 0) {
1927 if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) !=
1928 SHF_ALLOC)
1929 continue;
1930 } else {
1931 if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) !=
1932 (SHF_ALLOC | SHF_WRITE))
1933 continue;
1934 }
1935 if (s == interp) {
1936 if (k != 0)
1937 continue;
1938 } else if (s->sh_type == SHT_DYNSYM ||
1939 s->sh_type == SHT_STRTAB ||
1940 s->sh_type == SHT_HASH) {
1941 if (k != 1)
1942 continue;
1943 } else if (s->sh_type == SHT_RELX) {
1944 if (k != 2)
1945 continue;
1946 } else if (s->sh_type == SHT_NOBITS) {
1947 if (k != 4)
1948 continue;
1949 } else {
1950 if (k != 3)
1951 continue;
1952 }
1953 section_order[sh_order_index++] = i;
1954
1955 /* section matches: we align it and add its size */
1956 tmp = addr;
1957 addr = (addr + s->sh_addralign - 1) &
1958 ~(s->sh_addralign - 1);
1959 file_offset += (int) ( addr - tmp );
1960 s->sh_offset = file_offset;
1961 s->sh_addr = addr;
1962
1963 /* update program header infos */
1964 if (ph->p_offset == 0) {
1965 ph->p_offset = file_offset;
1966 ph->p_vaddr = addr;
1967 ph->p_paddr = ph->p_vaddr;
1968 }
1969 /* update dynamic relocation infos */
1970 if (s->sh_type == SHT_RELX) {
1971 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1972 if (!strcmp(strsec->data + s->sh_name, ".rel.got")) { // rel_size == 0) {
1973 rel_addr = addr;
1974 rel_size += s->sh_size; // XXX only first rel.
1975 }
1976 if (!strcmp(strsec->data + s->sh_name, ".rel.bss")) { // rel_size == 0) {
1977 bss_addr = addr;
1978 bss_size = s->sh_size; // XXX only first rel.
1979 }
1980 #else
1981 if (rel_size == 0)
1982 rel_addr = addr;
1983 rel_size += s->sh_size;
1984 #endif
1985 }
1986 addr += s->sh_size;
1987 if (s->sh_type != SHT_NOBITS)
1988 file_offset += s->sh_size;
1989 }
1990 }
1991 ph->p_filesz = file_offset - ph->p_offset;
1992 ph->p_memsz = addr - ph->p_vaddr;
1993 ph++;
1994 if (j == 0) {
1995 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF) {
1996 /* if in the middle of a page, we duplicate the page in
1997 memory so that one copy is RX and the other is RW */
1998 if ((addr & (s1->section_align - 1)) != 0)
1999 addr += s1->section_align;
2000 } else {
2001 addr = (addr + s1->section_align - 1) & ~(s1->section_align - 1);
2002 file_offset = (file_offset + s1->section_align - 1) &
2003 ~(s1->section_align - 1);
2004 }
2005 }
2006 }
2007
2008 /* if interpreter, then add corresponing program header */
2009 if (interp) {
2010 ph = &phdr[0];
2011
2012 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2013 {
2014 int len = phnum * sizeof(ElfW(Phdr));
2015
2016 ph->p_type = PT_PHDR;
2017 ph->p_offset = sizeof(ElfW(Ehdr));
2018 ph->p_vaddr = interp->sh_addr - len;
2019 ph->p_paddr = ph->p_vaddr;
2020 ph->p_filesz = ph->p_memsz = len;
2021 ph->p_flags = PF_R | PF_X;
2022 ph->p_align = 4; // interp->sh_addralign;
2023 ph++;
2024 }
2025 #endif
2026
2027 ph->p_type = PT_INTERP;
2028 ph->p_offset = interp->sh_offset;
2029 ph->p_vaddr = interp->sh_addr;
2030 ph->p_paddr = ph->p_vaddr;
2031 ph->p_filesz = interp->sh_size;
2032 ph->p_memsz = interp->sh_size;
2033 ph->p_flags = PF_R;
2034 ph->p_align = interp->sh_addralign;
2035 }
2036
2037 /* if dynamic section, then add corresponing program header */
2038 if (dynamic) {
2039 ElfW(Sym) *sym_end;
2040
2041 ph = &phdr[phnum - 1];
2042
2043 ph->p_type = PT_DYNAMIC;
2044 ph->p_offset = dynamic->sh_offset;
2045 ph->p_vaddr = dynamic->sh_addr;
2046 ph->p_paddr = ph->p_vaddr;
2047 ph->p_filesz = dynamic->sh_size;
2048 ph->p_memsz = dynamic->sh_size;
2049 ph->p_flags = PF_R | PF_W;
2050 ph->p_align = dynamic->sh_addralign;
2051
2052 /* put GOT dynamic section address */
2053 put32(s1->got->data, dynamic->sh_addr);
2054
2055 /* relocate the PLT */
2056 if (file_type == TCC_OUTPUT_EXE
2057 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
2058 || file_type == TCC_OUTPUT_DLL
2059 #endif
2060 ) {
2061 uint8_t *p, *p_end;
2062
2063 p = s1->plt->data;
2064 p_end = p + s1->plt->data_offset;
2065 if (p < p_end) {
2066 #if defined(TCC_TARGET_I386)
2067 put32(p + 2, get32(p + 2) + s1->got->sh_addr);
2068 put32(p + 8, get32(p + 8) + s1->got->sh_addr);
2069 p += 16;
2070 while (p < p_end) {
2071 put32(p + 2, get32(p + 2) + s1->got->sh_addr);
2072 p += 16;
2073 }
2074 #elif defined(TCC_TARGET_X86_64)
2075 int x = s1->got->sh_addr - s1->plt->sh_addr - 6;
2076 put32(p + 2, get32(p + 2) + x);
2077 put32(p + 8, get32(p + 8) + x - 6);
2078 p += 16;
2079 while (p < p_end) {
2080 put32(p + 2, get32(p + 2) + x + s1->plt->data - p);
2081 p += 16;
2082 }
2083 #elif defined(TCC_TARGET_ARM)
2084 int x;
2085 x=s1->got->sh_addr - s1->plt->sh_addr - 12;
2086 p += 16;
2087 while (p < p_end) {
2088 if (get32(p) == 0x46c04778) /* PLT Thumb stub present */
2089 p += 4;
2090 put32(p + 12, x + get32(p + 12) + s1->plt->data - p);
2091 p += 16;
2092 }
2093 #elif defined(TCC_TARGET_C67)
2094 /* XXX: TODO */
2095 #else
2096 #error unsupported CPU
2097 #endif
2098 }
2099 }
2100
2101 /* relocate symbols in .dynsym */
2102 sym_end = (ElfW(Sym) *)(s1->dynsym->data + s1->dynsym->data_offset);
2103 for(sym = (ElfW(Sym) *)s1->dynsym->data + 1;
2104 sym < sym_end;
2105 sym++) {
2106 if (sym->st_shndx == SHN_UNDEF) {
2107 /* relocate to the PLT if the symbol corresponds
2108 to a PLT entry */
2109 if (sym->st_value)
2110 sym->st_value += s1->plt->sh_addr;
2111 } else if (sym->st_shndx < SHN_LORESERVE) {
2112 /* do symbol relocation */
2113 sym->st_value += s1->sections[sym->st_shndx]->sh_addr;
2114 }
2115 }
2116
2117 /* put dynamic section entries */
2118 dynamic->data_offset = saved_dynamic_data_offset;
2119 put_dt(dynamic, DT_HASH, s1->dynsym->hash->sh_addr);
2120 put_dt(dynamic, DT_STRTAB, dynstr->sh_addr);
2121 put_dt(dynamic, DT_SYMTAB, s1->dynsym->sh_addr);
2122 put_dt(dynamic, DT_STRSZ, dynstr->data_offset);
2123 put_dt(dynamic, DT_SYMENT, sizeof(ElfW(Sym)));
2124 #ifdef TCC_TARGET_X86_64
2125 put_dt(dynamic, DT_RELA, rel_addr);
2126 put_dt(dynamic, DT_RELASZ, rel_size);
2127 put_dt(dynamic, DT_RELAENT, sizeof(ElfW_Rel));
2128 #else
2129 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2130 put_dt(dynamic, DT_PLTGOT, s1->got->sh_addr);
2131 put_dt(dynamic, DT_PLTRELSZ, rel_size);
2132 put_dt(dynamic, DT_JMPREL, rel_addr);
2133 put_dt(dynamic, DT_PLTREL, DT_REL);
2134 put_dt(dynamic, DT_REL, bss_addr);
2135 put_dt(dynamic, DT_RELSZ, bss_size);
2136 #else
2137 put_dt(dynamic, DT_REL, rel_addr);
2138 put_dt(dynamic, DT_RELSZ, rel_size);
2139 put_dt(dynamic, DT_RELENT, sizeof(ElfW_Rel));
2140 #endif
2141 #endif
2142 if (s1->do_debug)
2143 put_dt(dynamic, DT_DEBUG, 0);
2144 put_dt(dynamic, DT_NULL, 0);
2145 }
2146
2147 ehdr.e_phentsize = sizeof(ElfW(Phdr));
2148 ehdr.e_phnum = phnum;
2149 ehdr.e_phoff = sizeof(ElfW(Ehdr));
2150 }
2151
2152 /* all other sections come after */
2153 for(i = 1; i < s1->nb_sections; i++) {
2154 s = s1->sections[i];
2155 if (phnum > 0 && (s->sh_flags & SHF_ALLOC))
2156 continue;
2157 section_order[sh_order_index++] = i;
2158
2159 file_offset = (file_offset + s->sh_addralign - 1) &
2160 ~(s->sh_addralign - 1);
2161 s->sh_offset = file_offset;
2162 if (s->sh_type != SHT_NOBITS)
2163 file_offset += s->sh_size;
2164 }
2165
2166 /* if building executable or DLL, then relocate each section
2167 except the GOT which is already relocated */
2168 if (file_type != TCC_OUTPUT_OBJ) {
2169 relocate_syms(s1, 0);
2170
2171 if (s1->nb_errors != 0) {
2172 fail:
2173 ret = -1;
2174 goto the_end;
2175 }
2176
2177 /* relocate sections */
2178 /* XXX: ignore sections with allocated relocations ? */
2179 for(i = 1; i < s1->nb_sections; i++) {
2180 s = s1->sections[i];
2181 if (s->reloc && s != s1->got)
2182 relocate_section(s1, s);
2183 }
2184
2185 /* relocate relocation entries if the relocation tables are
2186 allocated in the executable */
2187 for(i = 1; i < s1->nb_sections; i++) {
2188 s = s1->sections[i];
2189 if ((s->sh_flags & SHF_ALLOC) &&
2190 s->sh_type == SHT_RELX) {
2191 relocate_rel(s1, s);
2192 }
2193 }
2194
2195 /* get entry point address */
2196 if (file_type == TCC_OUTPUT_EXE)
2197 ehdr.e_entry = get_elf_sym_addr(s1, "_start", 1);
2198 else
2199 ehdr.e_entry = text_section->sh_addr; /* XXX: is it correct ? */
2200 }
2201 if (file_type == TCC_OUTPUT_EXE && s1->static_link)
2202 fill_got(s1);
2203
2204 /* write elf file */
2205 if (file_type == TCC_OUTPUT_OBJ)
2206 mode = 0666;
2207 else
2208 mode = 0777;
2209 unlink(filename);
2210 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, mode);
2211 if (fd < 0) {
2212 tcc_error_noabort("could not write '%s'", filename);
2213 goto fail;
2214 }
2215 f = fdopen(fd, "wb");
2216 if (s1->verbose)
2217 printf("<- %s\n", filename);
2218
2219 #ifdef TCC_TARGET_COFF
2220 if (s1->output_format == TCC_OUTPUT_FORMAT_COFF) {
2221 tcc_output_coff(s1, f);
2222 } else
2223 #endif
2224 if (s1->output_format == TCC_OUTPUT_FORMAT_ELF) {
2225 sort_syms(s1, symtab_section);
2226
2227 /* align to 4 */
2228 file_offset = (file_offset + 3) & -4;
2229
2230 /* fill header */
2231 ehdr.e_ident[0] = ELFMAG0;
2232 ehdr.e_ident[1] = ELFMAG1;
2233 ehdr.e_ident[2] = ELFMAG2;
2234 ehdr.e_ident[3] = ELFMAG3;
2235 ehdr.e_ident[4] = ELFCLASSW;
2236 ehdr.e_ident[5] = ELFDATA2LSB;
2237 ehdr.e_ident[6] = EV_CURRENT;
2238 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2239 ehdr.e_ident[EI_OSABI] = ELFOSABI_FREEBSD;
2240 #endif
2241 #ifdef TCC_TARGET_ARM
2242 #ifdef TCC_ARM_EABI
2243 ehdr.e_ident[EI_OSABI] = 0;
2244 ehdr.e_flags = EF_ARM_EABI_VER4;
2245 if (file_type == TCC_OUTPUT_EXE || file_type == TCC_OUTPUT_DLL)
2246 ehdr.e_flags |= EF_ARM_HASENTRY;
2247 if (s1->float_abi == ARM_HARD_FLOAT)
2248 ehdr.e_flags |= EF_ARM_VFP_FLOAT;
2249 else
2250 ehdr.e_flags |= EF_ARM_SOFT_FLOAT;
2251 #else
2252 ehdr.e_ident[EI_OSABI] = ELFOSABI_ARM;
2253 #endif
2254 #endif
2255 switch(file_type) {
2256 default:
2257 case TCC_OUTPUT_EXE:
2258 ehdr.e_type = ET_EXEC;
2259 break;
2260 case TCC_OUTPUT_DLL:
2261 ehdr.e_type = ET_DYN;
2262 break;
2263 case TCC_OUTPUT_OBJ:
2264 ehdr.e_type = ET_REL;
2265 break;
2266 }
2267 ehdr.e_machine = EM_TCC_TARGET;
2268 ehdr.e_version = EV_CURRENT;
2269 ehdr.e_shoff = file_offset;
2270 ehdr.e_ehsize = sizeof(ElfW(Ehdr));
2271 ehdr.e_shentsize = sizeof(ElfW(Shdr));
2272 ehdr.e_shnum = shnum;
2273 ehdr.e_shstrndx = shnum - 1;
2274
2275 fwrite(&ehdr, 1, sizeof(ElfW(Ehdr)), f);
2276 fwrite(phdr, 1, phnum * sizeof(ElfW(Phdr)), f);
2277 offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr));
2278
2279 for(i=1;i<s1->nb_sections;i++) {
2280 s = s1->sections[section_order[i]];
2281 if (s->sh_type != SHT_NOBITS) {
2282 if (s->sh_type == SHT_DYNSYM)
2283 patch_dynsym_undef(s1, s);
2284 while (offset < s->sh_offset) {
2285 fputc(0, f);
2286 offset++;
2287 }
2288 size = s->sh_size;
2289 fwrite(s->data, 1, size, f);
2290 offset += size;
2291 }
2292 }
2293
2294 /* output section headers */
2295 while (offset < ehdr.e_shoff) {
2296 fputc(0, f);
2297 offset++;
2298 }
2299
2300 for(i=0;i<s1->nb_sections;i++) {
2301 sh = &shdr;
2302 memset(sh, 0, sizeof(ElfW(Shdr)));
2303 s = s1->sections[i];
2304 if (s) {
2305 sh->sh_name = s->sh_name;
2306 sh->sh_type = s->sh_type;
2307 sh->sh_flags = s->sh_flags;
2308 sh->sh_entsize = s->sh_entsize;
2309 sh->sh_info = s->sh_info;
2310 if (s->link)
2311 sh->sh_link = s->link->sh_num;
2312 sh->sh_addralign = s->sh_addralign;
2313 sh->sh_addr = s->sh_addr;
2314 sh->sh_offset = s->sh_offset;
2315 sh->sh_size = s->sh_size;
2316 }
2317 fwrite(sh, 1, sizeof(ElfW(Shdr)), f);
2318 }
2319 } else {
2320 tcc_output_binary(s1, f, section_order);
2321 }
2322 fclose(f);
2323
2324 ret = 0;
2325 the_end:
2326 tcc_free(s1->symtab_to_dynsym);
2327 tcc_free(section_order);
2328 tcc_free(phdr);
2329 tcc_free(s1->sym_attrs);
2330 return ret;
2331 }
2332
2333 LIBTCCAPI int tcc_output_file(TCCState *s, const char *filename)
2334 {
2335 int ret;
2336 #ifdef TCC_TARGET_PE
2337 if (s->output_type != TCC_OUTPUT_OBJ) {
2338 ret = pe_output_file(s, filename);
2339 } else
2340 #endif
2341 {
2342 ret = elf_output_file(s, filename);
2343 }
2344 return ret;
2345 }
2346
2347 static void *load_data(int fd, unsigned long file_offset, unsigned long size)
2348 {
2349 void *data;
2350
2351 data = tcc_malloc(size);
2352 lseek(fd, file_offset, SEEK_SET);
2353 read(fd, data, size);
2354 return data;
2355 }
2356
2357 typedef struct SectionMergeInfo {
2358 Section *s; /* corresponding existing section */
2359 unsigned long offset; /* offset of the new section in the existing section */
2360 uint8_t new_section; /* true if section 's' was added */
2361 uint8_t link_once; /* true if link once section */
2362 } SectionMergeInfo;
2363
2364 /* load an object file and merge it with current files */
2365 /* XXX: handle correctly stab (debug) info */
2366 ST_FUNC int tcc_load_object_file(TCCState *s1,
2367 int fd, unsigned long file_offset)
2368 {
2369 ElfW(Ehdr) ehdr;
2370 ElfW(Shdr) *shdr, *sh;
2371 int size, i, j, offset, offseti, nb_syms, sym_index, ret;
2372 unsigned char *strsec, *strtab;
2373 int *old_to_new_syms;
2374 char *sh_name, *name;
2375 SectionMergeInfo *sm_table, *sm;
2376 ElfW(Sym) *sym, *symtab;
2377 ElfW_Rel *rel, *rel_end;
2378 Section *s;
2379
2380 int stab_index;
2381 int stabstr_index;
2382
2383 stab_index = stabstr_index = 0;
2384
2385 if (read(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr))
2386 goto fail1;
2387 if (ehdr.e_ident[0] != ELFMAG0 ||
2388 ehdr.e_ident[1] != ELFMAG1 ||
2389 ehdr.e_ident[2] != ELFMAG2 ||
2390 ehdr.e_ident[3] != ELFMAG3)
2391 goto fail1;
2392 /* test if object file */
2393 if (ehdr.e_type != ET_REL)
2394 goto fail1;
2395 /* test CPU specific stuff */
2396 if (ehdr.e_ident[5] != ELFDATA2LSB ||
2397 ehdr.e_machine != EM_TCC_TARGET) {
2398 fail1:
2399 tcc_error_noabort("invalid object file");
2400 return -1;
2401 }
2402 /* read sections */
2403 shdr = load_data(fd, file_offset + ehdr.e_shoff,
2404 sizeof(ElfW(Shdr)) * ehdr.e_shnum);
2405 sm_table = tcc_mallocz(sizeof(SectionMergeInfo) * ehdr.e_shnum);
2406
2407 /* load section names */
2408 sh = &shdr[ehdr.e_shstrndx];
2409 strsec = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2410
2411 /* load symtab and strtab */
2412 old_to_new_syms = NULL;
2413 symtab = NULL;
2414 strtab = NULL;
2415 nb_syms = 0;
2416 for(i = 1; i < ehdr.e_shnum; i++) {
2417 sh = &shdr[i];
2418 if (sh->sh_type == SHT_SYMTAB) {
2419 if (symtab) {
2420 tcc_error_noabort("object must contain only one symtab");
2421 fail:
2422 ret = -1;
2423 goto the_end;
2424 }
2425 nb_syms = sh->sh_size / sizeof(ElfW(Sym));
2426 symtab = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2427 sm_table[i].s = symtab_section;
2428
2429 /* now load strtab */
2430 sh = &shdr[sh->sh_link];
2431 strtab = load_data(fd, file_offset + sh->sh_offset, sh->sh_size);
2432 }
2433 }
2434
2435 /* now examine each section and try to merge its content with the
2436 ones in memory */
2437 for(i = 1; i < ehdr.e_shnum; i++) {
2438 /* no need to examine section name strtab */
2439 if (i == ehdr.e_shstrndx)
2440 continue;
2441 sh = &shdr[i];
2442 sh_name = strsec + sh->sh_name;
2443 /* ignore sections types we do not handle */
2444 if (sh->sh_type != SHT_PROGBITS &&
2445 sh->sh_type != SHT_RELX &&
2446 #ifdef TCC_ARM_EABI
2447 sh->sh_type != SHT_ARM_EXIDX &&
2448 #endif
2449 sh->sh_type != SHT_NOBITS &&
2450 sh->sh_type != SHT_PREINIT_ARRAY &&
2451 sh->sh_type != SHT_INIT_ARRAY &&
2452 sh->sh_type != SHT_FINI_ARRAY &&
2453 strcmp(sh_name, ".stabstr")
2454 )
2455 continue;
2456 if (sh->sh_addralign < 1)
2457 sh->sh_addralign = 1;
2458 /* find corresponding section, if any */
2459 for(j = 1; j < s1->nb_sections;j++) {
2460 s = s1->sections[j];
2461 if (!strcmp(s->name, sh_name)) {
2462 if (!strncmp(sh_name, ".gnu.linkonce",
2463 sizeof(".gnu.linkonce") - 1)) {
2464 /* if a 'linkonce' section is already present, we
2465 do not add it again. It is a little tricky as
2466 symbols can still be defined in
2467 it. */
2468 sm_table[i].link_once = 1;
2469 goto next;
2470 } else {
2471 goto found;
2472 }
2473 }
2474 }
2475 /* not found: create new section */
2476 s = new_section(s1, sh_name, sh->sh_type, sh->sh_flags);
2477 /* take as much info as possible from the section. sh_link and
2478 sh_info will be updated later */
2479 s->sh_addralign = sh->sh_addralign;
2480 s->sh_entsize = sh->sh_entsize;
2481 sm_table[i].new_section = 1;
2482 found:
2483 if (sh->sh_type != s->sh_type) {
2484 tcc_error_noabort("invalid section type");
2485 goto fail;
2486 }
2487
2488 /* align start of section */
2489 offset = s->data_offset;
2490
2491 if (0 == strcmp(sh_name, ".stab")) {
2492 stab_index = i;
2493 goto no_align;
2494 }
2495 if (0 == strcmp(sh_name, ".stabstr")) {
2496 stabstr_index = i;
2497 goto no_align;
2498 }
2499
2500 size = sh->sh_addralign - 1;
2501 offset = (offset + size) & ~size;
2502 if (sh->sh_addralign > s->sh_addralign)
2503 s->sh_addralign = sh->sh_addralign;
2504 s->data_offset = offset;
2505 no_align:
2506 sm_table[i].offset = offset;
2507 sm_table[i].s = s;
2508 /* concatenate sections */
2509 size = sh->sh_size;
2510 if (sh->sh_type != SHT_NOBITS) {
2511 unsigned char *ptr;
2512 lseek(fd, file_offset + sh->sh_offset, SEEK_SET);
2513 ptr = section_ptr_add(s, size);
2514 read(fd, ptr, size);
2515 } else {
2516 s->data_offset += size;
2517 }
2518 next: ;
2519 }
2520
2521 /* //gr relocate stab strings */
2522 if (stab_index && stabstr_index) {
2523 Stab_Sym *a, *b;
2524 unsigned o;
2525 s = sm_table[stab_index].s;
2526 a = (Stab_Sym *)(s->data + sm_table[stab_index].offset);
2527 b = (Stab_Sym *)(s->data + s->data_offset);
2528 o = sm_table[stabstr_index].offset;
2529 while (a < b)
2530 a->n_strx += o, a++;
2531 }
2532
2533 /* second short pass to update sh_link and sh_info fields of new
2534 sections */
2535 for(i = 1; i < ehdr.e_shnum; i++) {
2536 s = sm_table[i].s;
2537 if (!s || !sm_table[i].new_section)
2538 continue;
2539 sh = &shdr[i];
2540 if (sh->sh_link > 0)
2541 s->link = sm_table[sh->sh_link].s;
2542 if (sh->sh_type == SHT_RELX) {
2543 s->sh_info = sm_table[sh->sh_info].s->sh_num;
2544 /* update backward link */
2545 s1->sections[s->sh_info]->reloc = s;
2546 }
2547 }
2548 sm = sm_table;
2549
2550 /* resolve symbols */
2551 old_to_new_syms = tcc_mallocz(nb_syms * sizeof(int));
2552
2553 sym = symtab + 1;
2554 for(i = 1; i < nb_syms; i++, sym++) {
2555 if (sym->st_shndx != SHN_UNDEF &&
2556 sym->st_shndx < SHN_LORESERVE) {
2557 sm = &sm_table[sym->st_shndx];
2558 if (sm->link_once) {
2559 /* if a symbol is in a link once section, we use the
2560 already defined symbol. It is very important to get
2561 correct relocations */
2562 if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
2563 name = strtab + sym->st_name;
2564 sym_index = find_elf_sym(symtab_section, name);
2565 if (sym_index)
2566 old_to_new_syms[i] = sym_index;
2567 }
2568 continue;
2569 }
2570 /* if no corresponding section added, no need to add symbol */
2571 if (!sm->s)
2572 continue;
2573 /* convert section number */
2574 sym->st_shndx = sm->s->sh_num;
2575 /* offset value */
2576 sym->st_value += sm->offset;
2577 }
2578 /* add symbol */
2579 name = strtab + sym->st_name;
2580 sym_index = add_elf_sym(symtab_section, sym->st_value, sym->st_size,
2581 sym->st_info, sym->st_other,
2582 sym->st_shndx, name);
2583 old_to_new_syms[i] = sym_index;
2584 }
2585
2586 /* third pass to patch relocation entries */
2587 for(i = 1; i < ehdr.e_shnum; i++) {
2588 s = sm_table[i].s;
2589 if (!s)
2590 continue;
2591 sh = &shdr[i];
2592 offset = sm_table[i].offset;
2593 switch(s->sh_type) {
2594 case SHT_RELX:
2595 /* take relocation offset information */
2596 offseti = sm_table[sh->sh_info].offset;
2597 rel_end = (ElfW_Rel *)(s->data + s->data_offset);
2598 for(rel = (ElfW_Rel *)(s->data + offset);
2599 rel < rel_end;
2600 rel++) {
2601 int type;
2602 unsigned sym_index;
2603 /* convert symbol index */
2604 type = ELFW(R_TYPE)(rel->r_info);
2605 sym_index = ELFW(R_SYM)(rel->r_info);
2606 /* NOTE: only one symtab assumed */
2607 if (sym_index >= nb_syms)
2608 goto invalid_reloc;
2609 sym_index = old_to_new_syms[sym_index];
2610 /* ignore link_once in rel section. */
2611 if (!sym_index && !sm->link_once
2612 #ifdef TCC_TARGET_ARM
2613 && type != R_ARM_V4BX
2614 #endif
2615 ) {
2616 invalid_reloc:
2617 tcc_error_noabort("Invalid relocation entry [%2d] '%s' @ %.8x",
2618 i, strsec + sh->sh_name, rel->r_offset);
2619 goto fail;
2620 }
2621 rel->r_info = ELFW(R_INFO)(sym_index, type);
2622 /* offset the relocation offset */
2623 rel->r_offset += offseti;
2624 #ifdef TCC_TARGET_ARM
2625 /* Jumps and branches from a Thumb code to a PLT entry need
2626 special handling since PLT entries are ARM code.
2627 Unconditional bl instructions referencing PLT entries are
2628 handled by converting these instructions into blx
2629 instructions. Other case of instructions referencing a PLT
2630 entry require to add a Thumb stub before the PLT entry to
2631 switch to ARM mode. We set bit 0 of the got offset of a
2632 symbol to indicate such a case. */
2633 if (type == R_ARM_THM_JUMP24)
2634 alloc_sym_attr(s1, sym_index)->plt_thumb_stub = 1;
2635 #endif
2636 }
2637 break;
2638 default:
2639 break;
2640 }
2641 }
2642
2643 ret = 0;
2644 the_end:
2645 tcc_free(symtab);
2646 tcc_free(strtab);
2647 tcc_free(old_to_new_syms);
2648 tcc_free(sm_table);
2649 tcc_free(strsec);
2650 tcc_free(shdr);
2651 return ret;
2652 }
2653
2654 typedef struct ArchiveHeader {
2655 char ar_name[16]; /* name of this member */
2656 char ar_date[12]; /* file mtime */
2657 char ar_uid[6]; /* owner uid; printed as decimal */
2658 char ar_gid[6]; /* owner gid; printed as decimal */
2659 char ar_mode[8]; /* file mode, printed as octal */
2660 char ar_size[10]; /* file size, printed as decimal */
2661 char ar_fmag[2]; /* should contain ARFMAG */
2662 } ArchiveHeader;
2663
2664 static int get_be32(const uint8_t *b)
2665 {
2666 return b[3] | (b[2] << 8) | (b[1] << 16) | (b[0] << 24);
2667 }
2668
2669 /* load only the objects which resolve undefined symbols */
2670 static int tcc_load_alacarte(TCCState *s1, int fd, int size)
2671 {
2672 int i, bound, nsyms, sym_index, off, ret;
2673 uint8_t *data;
2674 const char *ar_names, *p;
2675 const uint8_t *ar_index;
2676 ElfW(Sym) *sym;
2677
2678 data = tcc_malloc(size);
2679 if (read(fd, data, size) != size)
2680 goto fail;
2681 nsyms = get_be32(data);
2682 ar_index = data + 4;
2683 ar_names = ar_index + nsyms * 4;
2684
2685 do {
2686 bound = 0;
2687 for(p = ar_names, i = 0; i < nsyms; i++, p += strlen(p)+1) {
2688 sym_index = find_elf_sym(symtab_section, p);
2689 if(sym_index) {
2690 sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
2691 if(sym->st_shndx == SHN_UNDEF) {
2692 off = get_be32(ar_index + i * 4) + sizeof(ArchiveHeader);
2693 #if 0
2694 printf("%5d\t%s\t%08x\n", i, p, sym->st_shndx);
2695 #endif
2696 ++bound;
2697 lseek(fd, off, SEEK_SET);
2698 if(tcc_load_object_file(s1, fd, off) < 0) {
2699 fail:
2700 ret = -1;
2701 goto the_end;
2702 }
2703 }
2704 }
2705 }
2706 } while(bound);
2707 ret = 0;
2708 the_end:
2709 tcc_free(data);
2710 return ret;
2711 }
2712
2713 /* load a '.a' file */
2714 ST_FUNC int tcc_load_archive(TCCState *s1, int fd)
2715 {
2716 ArchiveHeader hdr;
2717 char ar_size[11];
2718 char ar_name[17];
2719 char magic[8];
2720 int size, len, i;
2721 unsigned long file_offset;
2722
2723 /* skip magic which was already checked */
2724 read(fd, magic, sizeof(magic));
2725
2726 for(;;) {
2727 len = read(fd, &hdr, sizeof(hdr));
2728 if (len == 0)
2729 break;
2730 if (len != sizeof(hdr)) {
2731 tcc_error_noabort("invalid archive");
2732 return -1;
2733 }
2734 memcpy(ar_size, hdr.ar_size, sizeof(hdr.ar_size));
2735 ar_size[sizeof(hdr.ar_size)] = '\0';
2736 size = strtol(ar_size, NULL, 0);
2737 memcpy(ar_name, hdr.ar_name, sizeof(hdr.ar_name));
2738 for(i = sizeof(hdr.ar_name) - 1; i >= 0; i--) {
2739 if (ar_name[i] != ' ')
2740 break;
2741 }
2742 ar_name[i + 1] = '\0';
2743 // printf("name='%s' size=%d %s\n", ar_name, size, ar_size);
2744 file_offset = lseek(fd, 0, SEEK_CUR);
2745 /* align to even */
2746 size = (size + 1) & ~1;
2747 if (!strcmp(ar_name, "/")) {
2748 /* coff symbol table : we handle it */
2749 if(s1->alacarte_link)
2750 return tcc_load_alacarte(s1, fd, size);
2751 } else if (!strcmp(ar_name, "//") ||
2752 !strcmp(ar_name, "__.SYMDEF") ||
2753 !strcmp(ar_name, "__.SYMDEF/") ||
2754 !strcmp(ar_name, "ARFILENAMES/")) {
2755 /* skip symbol table or archive names */
2756 } else {
2757 if (tcc_load_object_file(s1, fd, file_offset) < 0)
2758 return -1;
2759 }
2760 lseek(fd, file_offset + size, SEEK_SET);
2761 }
2762 return 0;
2763 }
2764
2765 #ifndef TCC_TARGET_PE
2766 /* load a DLL and all referenced DLLs. 'level = 0' means that the DLL
2767 is referenced by the user (so it should be added as DT_NEEDED in
2768 the generated ELF file) */
2769 ST_FUNC int tcc_load_dll(TCCState *s1, int fd, const char *filename, int level)
2770 {
2771 ElfW(Ehdr) ehdr;
2772 ElfW(Shdr) *shdr, *sh, *sh1;
2773 int i, j, nb_syms, nb_dts, sym_bind, ret;
2774 ElfW(Sym) *sym, *dynsym;
2775 ElfW(Dyn) *dt, *dynamic;
2776 unsigned char *dynstr;
2777 const char *name, *soname;
2778 DLLReference *dllref;
2779
2780 read(fd, &ehdr, sizeof(ehdr));
2781
2782 /* test CPU specific stuff */
2783 if (ehdr.e_ident[5] != ELFDATA2LSB ||
2784 ehdr.e_machine != EM_TCC_TARGET) {
2785 tcc_error_noabort("bad architecture");
2786 return -1;
2787 }
2788
2789 /* read sections */
2790 shdr = load_data(fd, ehdr.e_shoff, sizeof(ElfW(Shdr)) * ehdr.e_shnum);
2791
2792 /* load dynamic section and dynamic symbols */
2793 nb_syms = 0;
2794 nb_dts = 0;
2795 dynamic = NULL;
2796 dynsym = NULL; /* avoid warning */
2797 dynstr = NULL; /* avoid warning */
2798 for(i = 0, sh = shdr; i < ehdr.e_shnum; i++, sh++) {
2799 switch(sh->sh_type) {
2800 case SHT_DYNAMIC:
2801 nb_dts = sh->sh_size / sizeof(ElfW(Dyn));
2802 dynamic = load_data(fd, sh->sh_offset, sh->sh_size);
2803 break;
2804 case SHT_DYNSYM:
2805 nb_syms = sh->sh_size / sizeof(ElfW(Sym));
2806 dynsym = load_data(fd, sh->sh_offset, sh->sh_size);
2807 sh1 = &shdr[sh->sh_link];
2808 dynstr = load_data(fd, sh1->sh_offset, sh1->sh_size);
2809 break;
2810 default:
2811 break;
2812 }
2813 }
2814
2815 /* compute the real library name */
2816 soname = tcc_basename(filename);
2817
2818 for(i = 0, dt = dynamic; i < nb_dts; i++, dt++) {
2819 if (dt->d_tag == DT_SONAME) {
2820 soname = dynstr + dt->d_un.d_val;
2821 }
2822 }
2823
2824 /* if the dll is already loaded, do not load it */
2825 for(i = 0; i < s1->nb_loaded_dlls; i++) {
2826 dllref = s1->loaded_dlls[i];
2827 if (!strcmp(soname, dllref->name)) {
2828 /* but update level if needed */
2829 if (level < dllref->level)
2830 dllref->level = level;
2831 ret = 0;
2832 goto the_end;
2833 }
2834 }
2835
2836 // printf("loading dll '%s'\n", soname);
2837
2838 /* add the dll and its level */
2839 dllref = tcc_mallocz(sizeof(DLLReference) + strlen(soname));
2840 dllref->level = level;
2841 strcpy(dllref->name, soname);
2842 dynarray_add((void ***)&s1->loaded_dlls, &s1->nb_loaded_dlls, dllref);
2843
2844 /* add dynamic symbols in dynsym_section */
2845 for(i = 1, sym = dynsym + 1; i < nb_syms; i++, sym++) {
2846 sym_bind = ELFW(ST_BIND)(sym->st_info);
2847 if (sym_bind == STB_LOCAL)
2848 continue;
2849 name = dynstr + sym->st_name;
2850 add_elf_sym(s1->dynsymtab_section, sym->st_value, sym->st_size,
2851 sym->st_info, sym->st_other, sym->st_shndx, name);
2852 }
2853
2854 /* load all referenced DLLs */
2855 for(i = 0, dt = dynamic; i < nb_dts; i++, dt++) {
2856 switch(dt->d_tag) {
2857 case DT_NEEDED:
2858 name = dynstr + dt->d_un.d_val;
2859 for(j = 0; j < s1->nb_loaded_dlls; j++) {
2860 dllref = s1->loaded_dlls[j];
2861 if (!strcmp(name, dllref->name))
2862 goto already_loaded;
2863 }
2864 if (tcc_add_dll(s1, name, AFF_REFERENCED_DLL) < 0) {
2865 tcc_error_noabort("referenced dll '%s' not found", name);
2866 ret = -1;
2867 goto the_end;
2868 }
2869 already_loaded:
2870 break;
2871 }
2872 }
2873 ret = 0;
2874 the_end:
2875 tcc_free(dynstr);
2876 tcc_free(dynsym);
2877 tcc_free(dynamic);
2878 tcc_free(shdr);
2879 return ret;
2880 }
2881
2882 #define LD_TOK_NAME 256
2883 #define LD_TOK_EOF (-1)
2884
2885 /* return next ld script token */
2886 static int ld_next(TCCState *s1, char *name, int name_size)
2887 {
2888 int c;
2889 char *q;
2890
2891 redo:
2892 switch(ch) {
2893 case ' ':
2894 case '\t':
2895 case '\f':
2896 case '\v':
2897 case '\r':
2898 case '\n':
2899 inp();
2900 goto redo;
2901 case '/':
2902 minp();
2903 if (ch == '*') {
2904 file->buf_ptr = parse_comment(file->buf_ptr);
2905 ch = file->buf_ptr[0];
2906 goto redo;
2907 } else {
2908 q = name;
2909 *q++ = '/';
2910 goto parse_name;
2911 }
2912 break;
2913 /* case 'a' ... 'z': */
2914 case 'a':
2915 case 'b':
2916 case 'c':
2917 case 'd':
2918 case 'e':
2919 case 'f':
2920 case 'g':
2921 case 'h':
2922 case 'i':
2923 case 'j':
2924 case 'k':
2925 case 'l':
2926 case 'm':
2927 case 'n':
2928 case 'o':
2929 case 'p':
2930 case 'q':
2931 case 'r':
2932 case 's':
2933 case 't':
2934 case 'u':
2935 case 'v':
2936 case 'w':
2937 case 'x':
2938 case 'y':
2939 case 'z':
2940 /* case 'A' ... 'z': */
2941 case 'A':
2942 case 'B':
2943 case 'C':
2944 case 'D':
2945 case 'E':
2946 case 'F':
2947 case 'G':
2948 case 'H':
2949 case 'I':
2950 case 'J':
2951 case 'K':
2952 case 'L':
2953 case 'M':
2954 case 'N':
2955 case 'O':
2956 case 'P':
2957 case 'Q':
2958 case 'R':
2959 case 'S':
2960 case 'T':
2961 case 'U':
2962 case 'V':
2963 case 'W':
2964 case 'X':
2965 case 'Y':
2966 case 'Z':
2967 case '_':
2968 case '\\':
2969 case '.':
2970 case '$':
2971 case '~':
2972 q = name;
2973 parse_name:
2974 for(;;) {
2975 if (!((ch >= 'a' && ch <= 'z') ||
2976 (ch >= 'A' && ch <= 'Z') ||
2977 (ch >= '0' && ch <= '9') ||
2978 strchr("/.-_+=$:\\,~", ch)))
2979 break;
2980 if ((q - name) < name_size - 1) {
2981 *q++ = ch;
2982 }
2983 minp();
2984 }
2985 *q = '\0';
2986 c = LD_TOK_NAME;
2987 break;
2988 case CH_EOF:
2989 c = LD_TOK_EOF;
2990 break;
2991 default:
2992 c = ch;
2993 inp();
2994 break;
2995 }
2996 #if 0
2997 printf("tok=%c %d\n", c, c);
2998 if (c == LD_TOK_NAME)
2999 printf(" name=%s\n", name);
3000 #endif
3001 return c;
3002 }
3003
3004 static int ld_add_file(TCCState *s1, const char filename[])
3005 {
3006 int ret;
3007
3008 ret = tcc_add_file_internal(s1, filename, 0);
3009 if (ret)
3010 ret = tcc_add_dll(s1, filename, 0);
3011 return ret;
3012 }
3013
3014 static inline int new_undef_syms(void)
3015 {
3016 int ret = 0;
3017 ret = new_undef_sym;
3018 new_undef_sym = 0;
3019 return ret;
3020 }
3021
3022 static int ld_add_file_list(TCCState *s1, const char *cmd, int as_needed)
3023 {
3024 char filename[1024], libname[1024];
3025 int t, group, nblibs = 0, ret = 0;
3026 char **libs = NULL;
3027
3028 group = !strcmp(cmd, "GROUP");
3029 if (!as_needed)
3030 new_undef_syms();
3031 t = ld_next(s1, filename, sizeof(filename));
3032 if (t != '(')
3033 expect("(");
3034 t = ld_next(s1, filename, sizeof(filename));
3035 for(;;) {
3036 libname[0] = '\0';
3037 if (t == LD_TOK_EOF) {
3038 tcc_error_noabort("unexpected end of file");
3039 ret = -1;
3040 goto lib_parse_error;
3041 } else if (t == ')') {
3042 break;
3043 } else if (t == '-') {
3044 t = ld_next(s1, filename, sizeof(filename));
3045 if ((t != LD_TOK_NAME) || (filename[0] != 'l')) {
3046 tcc_error_noabort("library name expected");
3047 ret = -1;
3048 goto lib_parse_error;
3049 }
3050 pstrcpy(libname, sizeof libname, &filename[1]);
3051 if (s1->static_link) {
3052 snprintf(filename, sizeof filename, "lib%s.a", libname);
3053 } else {
3054 snprintf(filename, sizeof filename, "lib%s.so", libname);
3055 }
3056 } else if (t != LD_TOK_NAME) {
3057 tcc_error_noabort("filename expected");
3058 ret = -1;
3059 goto lib_parse_error;
3060 }
3061 if (!strcmp(filename, "AS_NEEDED")) {
3062 ret = ld_add_file_list(s1, cmd, 1);
3063 if (ret)
3064 goto lib_parse_error;
3065 } else {
3066 /* TODO: Implement AS_NEEDED support. Ignore it for now */
3067 if (!as_needed) {
3068 ret = ld_add_file(s1, filename);
3069 if (ret)
3070 goto lib_parse_error;
3071 if (group) {
3072 /* Add the filename *and* the libname to avoid future conversions */
3073 dynarray_add((void ***) &libs, &nblibs, tcc_strdup(filename));
3074 if (libname[0] != '\0')
3075 dynarray_add((void ***) &libs, &nblibs, tcc_strdup(libname));
3076 }
3077 }
3078 }
3079 t = ld_next(s1, filename, sizeof(filename));
3080 if (t == ',') {
3081 t = ld_next(s1, filename, sizeof(filename));
3082 }
3083 }
3084 if (group && !as_needed) {
3085 while (new_undef_syms()) {
3086 int i;
3087
3088 for (i = 0; i < nblibs; i ++)
3089 ld_add_file(s1, libs[i]);
3090 }
3091 }
3092 lib_parse_error:
3093 dynarray_reset(&libs, &nblibs);
3094 return ret;
3095 }
3096
3097 /* interpret a subset of GNU ldscripts to handle the dummy libc.so
3098 files */
3099 ST_FUNC int tcc_load_ldscript(TCCState *s1)
3100 {
3101 char cmd[64];
3102 char filename[1024];
3103 int t, ret;
3104
3105 ch = file->buf_ptr[0];
3106 ch = handle_eob();
3107 for(;;) {
3108 t = ld_next(s1, cmd, sizeof(cmd));
3109 if (t == LD_TOK_EOF)
3110 return 0;
3111 else if (t != LD_TOK_NAME)
3112 return -1;
3113 if (!strcmp(cmd, "INPUT") ||
3114 !strcmp(cmd, "GROUP")) {
3115 ret = ld_add_file_list(s1, cmd, 0);
3116 if (ret)
3117 return ret;
3118 } else if (!strcmp(cmd, "OUTPUT_FORMAT") ||
3119 !strcmp(cmd, "TARGET")) {
3120 /* ignore some commands */
3121 t = ld_next(s1, cmd, sizeof(cmd));
3122 if (t != '(')
3123 expect("(");
3124 for(;;) {
3125 t = ld_next(s1, filename, sizeof(filename));
3126 if (t == LD_TOK_EOF) {
3127 tcc_error_noabort("unexpected end of file");
3128 return -1;
3129 } else if (t == ')') {
3130 break;
3131 }
3132 }
3133 } else {
3134 return -1;
3135 }
3136 }
3137 return 0;
3138 }
3139 #endif /* ndef TCC_TARGET_PE */
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