2 * ELF file handling for TCC
4 * Copyright (c) 2001-2004 Fabrice Bellard
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.
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.
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
23 /* Define this to get some debug output during relocation processing. */
26 /* XXX: avoid static variable */
27 static int new_undef_sym
= 0; /* Is there a new undefined sym since last new_undef_sym() */
29 ST_FUNC
int put_elf_str(Section
*s
, const char *sym
)
34 len
= strlen(sym
) + 1;
35 offset
= s
->data_offset
;
36 ptr
= section_ptr_add(s
, len
);
37 memcpy(ptr
, sym
, len
);
41 /* elf symbol hashing function */
42 static unsigned long elf_hash(const unsigned char *name
)
44 unsigned long h
= 0, g
;
47 h
= (h
<< 4) + *name
++;
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
)
61 int *ptr
, *hash
, nb_syms
, sym_index
, h
;
62 unsigned char *strtab
;
64 strtab
= s
->link
->data
;
65 nb_syms
= s
->data_offset
/ sizeof(ElfW(Sym
));
67 s
->hash
->data_offset
= 0;
68 ptr
= section_ptr_add(s
->hash
, (2 + nb_buckets
+ nb_syms
) * sizeof(int));
73 memset(hash
, 0, (nb_buckets
+ 1) * sizeof(int));
74 ptr
+= nb_buckets
+ 1;
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
;
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
)
94 int name_offset
, sym_index
;
99 sym
= section_ptr_add(s
, sizeof(ElfW(Sym
)));
101 name_offset
= put_elf_str(s
->link
, name
);
104 /* XXX: endianness */
105 sym
->st_name
= name_offset
;
106 sym
->st_value
= value
;
109 sym
->st_other
= other
;
110 sym
->st_shndx
= shndx
;
111 sym_index
= sym
- (ElfW(Sym
) *)s
->data
;
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 */
121 h
= elf_hash((unsigned char *) name
) % nbuckets
;
123 base
[2 + h
] = sym_index
;
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
);
138 /* find global ELF symbol 'name' and return its index. Return 0 if not
140 ST_FUNC
int find_elf_sym(Section
*s
, const char *name
)
144 int nbuckets
, sym_index
, h
;
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
))
158 sym_index
= ((int *)hs
->data
)[2 + nbuckets
+ sym_index
];
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
)
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
) {
173 tcc_error("%s not defined", name
);
176 return sym
->st_value
;
179 /* return elf symbol value */
180 LIBTCCAPI
void *tcc_get_symbol(TCCState
*s
, const char *name
)
182 return (void*)(uintptr_t)get_elf_sym_addr(s
, name
, 0);
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
)
189 return (void*)(uintptr_t)get_elf_sym_addr(s
, name
, 1);
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
)
199 int sym_bind
, sym_index
, sym_type
, esym_bind
;
200 unsigned char sym_vis
, esym_vis
, new_vis
;
202 sym_bind
= ELFW(ST_BIND
)(info
);
203 sym_type
= ELFW(ST_TYPE
)(info
);
204 sym_vis
= ELFW(ST_VISIBILITY
)(other
);
206 if (sym_bind
!= STB_LOCAL
) {
207 /* we search global or weak symbols */
208 sym_index
= find_elf_sym(s
, name
);
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
) {
219 } else if (sym_vis
== STV_DEFAULT
) {
222 new_vis
= (esym_vis
< sym_vis
) ? esym_vis
: sym_vis
;
224 esym
->st_other
= (esym
->st_other
& ~ELFW(ST_VISIBILITY
)(-1))
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 */
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 ... */
244 } else if (s
== tcc_state
->dynsymtab_section
) {
245 /* we accept that two DLL define the same symbol */
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
);
251 tcc_error_noabort("'%s' defined twice", name
);
255 esym
->st_info
= ELFW(ST_INFO
)(sym_bind
, sym_type
);
256 esym
->st_shndx
= sh_num
;
258 esym
->st_value
= value
;
259 esym
->st_size
= size
;
260 esym
->st_other
= other
;
264 sym_index
= put_elf_sym(s
, value
, size
,
265 ELFW(ST_INFO
)(sym_bind
, sym_type
), other
,
272 ST_FUNC
void put_elf_reloc(Section
*symtab
, Section
*s
, unsigned long offset
,
273 int type
, int symbol
)
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
285 sr
= new_section(tcc_state
, buf
, SHT_RELX
, symtab
->sh_flags
);
286 sr
->sh_entsize
= sizeof(ElfW_Rel
);
288 sr
->sh_info
= s
->sh_num
;
291 rel
= section_ptr_add(sr
, sizeof(ElfW_Rel
));
292 rel
->r_offset
= offset
;
293 rel
->r_info
= ELFW(R_INFO
)(symbol
, type
);
294 #ifdef TCC_TARGET_X86_64
299 /* put stab debug information */
301 ST_FUNC
void put_stabs(const char *str
, int type
, int other
, int desc
,
306 sym
= section_ptr_add(stab_section
, sizeof(Stab_Sym
));
308 sym
->n_strx
= put_elf_str(stabstr_section
, str
);
313 sym
->n_other
= other
;
315 sym
->n_value
= value
;
318 ST_FUNC
void put_stabs_r(const char *str
, int type
, int other
, int desc
,
319 unsigned long value
, Section
*sec
, int sym_index
)
321 put_stabs(str
, type
, other
, desc
, value
);
322 put_elf_reloc(symtab_section
, stab_section
,
323 stab_section
->data_offset
- sizeof(unsigned int),
324 R_DATA_32
, sym_index
);
327 ST_FUNC
void put_stabn(int type
, int other
, int desc
, int value
)
329 put_stabs(NULL
, type
, other
, desc
, value
);
332 ST_FUNC
void put_stabd(int type
, int other
, int desc
)
334 put_stabs(NULL
, type
, other
, desc
, 0);
337 /* Browse each elem of type <type> in section <sec> starting at elem <startoff>
338 using variable <elem> */
339 #define for_each_elem(sec, startoff, elem, type) \
340 for (elem = (type *) sec->data + startoff; \
341 elem < (type *) (sec->data + sec->data_offset); elem++)
343 /* In an ELF file symbol table, the local symbols must appear below
344 the global and weak ones. Since TCC cannot sort it while generating
345 the code, we must do it after. All the relocation tables are also
346 modified to take into account the symbol table sorting */
347 static void sort_syms(TCCState
*s1
, Section
*s
)
349 int *old_to_new_syms
;
357 nb_syms
= s
->data_offset
/ sizeof(ElfW(Sym
));
358 new_syms
= tcc_malloc(nb_syms
* sizeof(ElfW(Sym
)));
359 old_to_new_syms
= tcc_malloc(nb_syms
* sizeof(int));
361 /* first pass for local symbols */
362 p
= (ElfW(Sym
) *)s
->data
;
364 for(i
= 0; i
< nb_syms
; i
++) {
365 if (ELFW(ST_BIND
)(p
->st_info
) == STB_LOCAL
) {
366 old_to_new_syms
[i
] = q
- new_syms
;
371 /* save the number of local symbols in section header */
372 s
->sh_info
= q
- new_syms
;
374 /* then second pass for non local symbols */
375 p
= (ElfW(Sym
) *)s
->data
;
376 for(i
= 0; i
< nb_syms
; i
++) {
377 if (ELFW(ST_BIND
)(p
->st_info
) != STB_LOCAL
) {
378 old_to_new_syms
[i
] = q
- new_syms
;
384 /* we copy the new symbols to the old */
385 memcpy(s
->data
, new_syms
, nb_syms
* sizeof(ElfW(Sym
)));
388 /* now we modify all the relocations */
389 for(i
= 1; i
< s1
->nb_sections
; i
++) {
390 sr
= s1
->sections
[i
];
391 if (sr
->sh_type
== SHT_RELX
&& sr
->link
== s
) {
392 for_each_elem(sr
, 0, rel
, ElfW_Rel
) {
393 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
394 type
= ELFW(R_TYPE
)(rel
->r_info
);
395 sym_index
= old_to_new_syms
[sym_index
];
396 rel
->r_info
= ELFW(R_INFO
)(sym_index
, type
);
401 tcc_free(old_to_new_syms
);
404 /* relocate common symbols in the .bss section */
405 ST_FUNC
void relocate_common_syms(void)
408 unsigned long offset
, align
;
410 for_each_elem(symtab_section
, 1, sym
, ElfW(Sym
)) {
411 if (sym
->st_shndx
== SHN_COMMON
) {
413 align
= sym
->st_value
;
414 offset
= bss_section
->data_offset
;
415 offset
= (offset
+ align
- 1) & -align
;
416 sym
->st_value
= offset
;
417 sym
->st_shndx
= bss_section
->sh_num
;
418 offset
+= sym
->st_size
;
419 bss_section
->data_offset
= offset
;
424 /* relocate symbol table, resolve undefined symbols if do_resolve is
425 true and output error if undefined symbol. */
426 ST_FUNC
void relocate_syms(TCCState
*s1
, int do_resolve
)
428 ElfW(Sym
) *sym
, *esym
;
429 int sym_bind
, sh_num
, sym_index
;
432 for_each_elem(symtab_section
, 1, sym
, ElfW(Sym
)) {
433 sh_num
= sym
->st_shndx
;
434 if (sh_num
== SHN_UNDEF
) {
435 name
= (char *) strtab_section
->data
+ sym
->st_name
;
436 /* Use ld.so to resolve symbol for us (for tcc -run) */
438 #if defined TCC_IS_NATIVE && !defined _WIN32
440 name
= (char *) symtab_section
->link
->data
+ sym
->st_name
;
441 addr
= resolve_sym(s1
, name
);
443 sym
->st_value
= (addr_t
)addr
;
445 printf ("relocate_sym: %s -> 0x%x\n", name
, sym
->st_value
);
450 } else if (s1
->dynsym
) {
451 /* if dynamic symbol exist, then use it */
452 sym_index
= find_elf_sym(s1
->dynsym
, name
);
454 esym
= &((ElfW(Sym
) *)s1
->dynsym
->data
)[sym_index
];
455 sym
->st_value
= esym
->st_value
;
459 /* XXX: _fp_hw seems to be part of the ABI, so we ignore
461 if (!strcmp(name
, "_fp_hw"))
463 /* only weak symbols are accepted to be undefined. Their
465 sym_bind
= ELFW(ST_BIND
)(sym
->st_info
);
466 if (sym_bind
== STB_WEAK
) {
469 tcc_error_noabort("undefined symbol '%s'", name
);
471 } else if (sh_num
< SHN_LORESERVE
) {
472 /* add section base */
473 sym
->st_value
+= s1
->sections
[sym
->st_shndx
]->sh_addr
;
479 /* relocate a given section (CPU dependent) by applying the relocations
480 in the associated relocation section */
481 ST_FUNC
void relocate_section(TCCState
*s1
, Section
*s
)
483 Section
*sr
= s
->reloc
;
489 #if defined TCC_TARGET_I386 || defined TCC_TARGET_X86_64
490 ElfW_Rel
*qrel
= (ElfW_Rel
*) sr
->data
; /* ptr to next reloc entry reused */
494 for_each_elem(sr
, 0, rel
, ElfW_Rel
) {
495 ptr
= s
->data
+ rel
->r_offset
;
497 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
498 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
500 #ifdef TCC_TARGET_X86_64
501 val
+= rel
->r_addend
;
503 type
= ELFW(R_TYPE
)(rel
->r_info
);
504 addr
= s
->sh_addr
+ rel
->r_offset
;
508 #if defined(TCC_TARGET_I386)
510 if (s1
->output_type
== TCC_OUTPUT_DLL
) {
511 esym_index
= s1
->symtab_to_dynsym
[sym_index
];
512 qrel
->r_offset
= rel
->r_offset
;
514 qrel
->r_info
= ELFW(R_INFO
)(esym_index
, R_386_32
);
518 qrel
->r_info
= ELFW(R_INFO
)(0, R_386_RELATIVE
);
525 if (s1
->output_type
== TCC_OUTPUT_DLL
) {
527 esym_index
= s1
->symtab_to_dynsym
[sym_index
];
529 qrel
->r_offset
= rel
->r_offset
;
530 qrel
->r_info
= ELFW(R_INFO
)(esym_index
, R_386_PC32
);
535 *(int *)ptr
+= val
- addr
;
538 *(int *)ptr
+= val
- addr
;
545 *(int *)ptr
+= s1
->got
->sh_addr
- addr
;
548 *(int *)ptr
+= val
- s1
->got
->sh_addr
;
551 /* we load the got offset */
552 *(int *)ptr
+= s1
->sym_attrs
[sym_index
].got_offset
;
555 if (s1
->output_format
!= TCC_OUTPUT_FORMAT_BINARY
) {
557 tcc_error("can only produce 16-bit binary files");
559 *(short *)ptr
+= val
;
562 if (s1
->output_format
!= TCC_OUTPUT_FORMAT_BINARY
)
564 *(short *)ptr
+= val
- addr
;
566 #elif defined(TCC_TARGET_ARM)
572 int x
, is_thumb
, is_call
, h
, blx_avail
, is_bl
, th_ko
;
573 x
= (*(int *) ptr
) & 0xffffff;
574 if (sym
->st_shndx
== SHN_UNDEF
)
575 val
= s1
->plt
->sh_addr
;
577 printf ("reloc %d: x=0x%x val=0x%x ", type
, x
, val
);
579 (*(int *)ptr
) &= 0xff000000;
583 blx_avail
= (TCC_ARM_VERSION
>= 5);
585 is_bl
= (*(unsigned *) ptr
) >> 24 == 0xeb;
586 is_call
= (type
== R_ARM_CALL
|| (type
== R_ARM_PC24
&& is_bl
));
589 printf (" newx=0x%x name=%s\n", x
,
590 (char *) symtab_section
->link
->data
+ sym
->st_name
);
593 th_ko
= (x
& 3) && (!blx_avail
|| !is_call
);
594 if (th_ko
|| x
>= 0x2000000 || x
< -0x2000000)
595 tcc_error("can't relocate value at %x,%d",addr
, type
);
598 /* Only reached if blx is avail and it is a call */
601 (*(int *)ptr
) = 0xfa << 24; /* bl -> blx */
606 /* Since these relocations only concern Thumb-2 and blx instruction was
607 introduced before Thumb-2, we can assume blx is available and not
610 case R_ARM_THM_JUMP24
:
612 int x
, hi
, lo
, s
, j1
, j2
, i1
, i2
, imm10
, imm11
;
613 int to_thumb
, is_call
, to_plt
, blx_bit
= 1 << 12;
617 if (sym
->st_shndx
== SHN_UNDEF
&&
618 ELFW(ST_BIND
)(sym
->st_info
) == STB_WEAK
)
621 /* Get initial offset */
622 hi
= (*(uint16_t *)ptr
);
623 lo
= (*(uint16_t *)(ptr
+2));
631 x
= (s
<< 24) | (i1
<< 23) | (i2
<< 22) |
632 (imm10
<< 12) | (imm11
<< 1);
636 /* Relocation infos */
639 to_plt
= (val
>= plt
->sh_addr
) &&
640 (val
< plt
->sh_addr
+ plt
->data_offset
);
641 is_call
= (type
== R_ARM_THM_PC22
);
643 /* Compute final offset */
644 if (to_plt
&& !is_call
) /* Point to 1st instr of Thumb stub */
647 if (!to_thumb
&& is_call
) {
648 blx_bit
= 0; /* bl -> blx */
649 x
= (x
+ 3) & -4; /* Compute offset from aligned PC */
652 /* Check that relocation is possible
653 * offset must not be out of range
654 * if target is to be entered in arm mode:
656 - instruction must be a call (bl) or a jump to PLT */
657 if (!to_thumb
|| x
>= 0x1000000 || x
< -0x1000000)
658 if (to_thumb
|| (val
& 2) || (!is_call
&& !to_plt
))
659 tcc_error("can't relocate value at %x,%d",addr
, type
);
661 /* Compute and store final offset */
667 imm10
= (x
>> 12) & 0x3ff;
668 imm11
= (x
>> 1) & 0x7ff;
669 (*(uint16_t *)ptr
) = (uint16_t) ((hi
& 0xf800) |
671 (*(uint16_t *)(ptr
+2)) = (uint16_t) ((lo
& 0xc000) |
672 (j1
<< 13) | blx_bit
| (j2
<< 11) |
677 case R_ARM_MOVW_ABS_NC
:
680 if (type
== R_ARM_MOVT_ABS
)
683 imm4
= (val
>> 12) & 0xf;
684 x
= (imm4
<< 16) | imm12
;
685 if (type
== R_ARM_THM_MOVT_ABS
)
691 case R_ARM_THM_MOVT_ABS
:
692 case R_ARM_THM_MOVW_ABS_NC
:
694 int x
, i
, imm4
, imm3
, imm8
;
695 if (type
== R_ARM_THM_MOVT_ABS
)
698 imm3
= (val
>> 8) & 0x7;
700 imm4
= (val
>> 12) & 0xf;
701 x
= (imm3
<< 28) | (imm8
<< 16) | (i
<< 10) | imm4
;
702 if (type
== R_ARM_THM_MOVT_ABS
)
711 x
= (*(int *)ptr
) & 0x7fffffff;
712 (*(int *)ptr
) &= 0x80000000;
715 if((x
^(x
>>1))&0x40000000)
716 tcc_error("can't relocate value at %x,%d",addr
, type
);
717 (*(int *)ptr
) |= x
& 0x7fffffff;
723 *(int *)ptr
+= val
- addr
;
726 *(int *)ptr
+= s1
->got
->sh_addr
- addr
;
729 *(int *)ptr
+= val
- s1
->got
->sh_addr
;
732 /* we load the got offset */
733 *(int *)ptr
+= s1
->sym_attrs
[sym_index
].got_offset
;
738 /* trade Thumb support for ARMv4 support */
739 if ((0x0ffffff0 & *(int*)ptr
) == 0x012FFF10)
740 *(int*)ptr
^= 0xE12FFF10 ^ 0xE1A0F000; /* BX Rm -> MOV PC, Rm */
743 case R_ARM_JUMP_SLOT
:
744 *(addr_t
*)ptr
= val
;
747 /* Nothing to do. Normally used to indicate a dependency
748 on a certain symbol (like for exception handling under EABI). */
751 fprintf(stderr
,"FIXME: handle reloc type %x at %x [%p] to %x\n",
752 type
, (unsigned)addr
, ptr
, (unsigned)val
);
754 #elif defined(TCC_TARGET_C67)
762 /* put the low 16 bits of the absolute address
763 add to what is already there */
765 orig
= ((*(int *)(ptr
)) >> 7) & 0xffff;
766 orig
|= (((*(int *)(ptr
+4)) >> 7) & 0xffff) << 16;
768 /* patch both at once - assumes always in pairs Low - High */
770 *(int *) ptr
= (*(int *) ptr
& (~(0xffff << 7)) ) | (((val
+orig
) & 0xffff) << 7);
771 *(int *)(ptr
+4) = (*(int *)(ptr
+4) & (~(0xffff << 7)) ) | ((((val
+orig
)>>16) & 0xffff) << 7);
777 fprintf(stderr
,"FIXME: handle reloc type %x at %x [%p] to %x\n",
778 type
, (unsigned)addr
, ptr
, (unsigned)val
);
780 #elif defined(TCC_TARGET_X86_64)
782 if (s1
->output_type
== TCC_OUTPUT_DLL
) {
783 esym_index
= s1
->symtab_to_dynsym
[sym_index
];
784 qrel
->r_offset
= rel
->r_offset
;
786 qrel
->r_info
= ELFW(R_INFO
)(esym_index
, R_X86_64_64
);
787 qrel
->r_addend
= rel
->r_addend
;
791 qrel
->r_info
= ELFW(R_INFO
)(0, R_X86_64_RELATIVE
);
792 qrel
->r_addend
= *(long long *)ptr
+ val
;
796 *(long long *)ptr
+= val
;
800 if (s1
->output_type
== TCC_OUTPUT_DLL
) {
801 /* XXX: this logic may depend on TCC's codegen
802 now TCC uses R_X86_64_32 even for a 64bit pointer */
803 qrel
->r_info
= ELFW(R_INFO
)(0, R_X86_64_RELATIVE
);
804 qrel
->r_addend
= *(int *)ptr
+ val
;
811 if (s1
->output_type
== TCC_OUTPUT_DLL
) {
813 esym_index
= s1
->symtab_to_dynsym
[sym_index
];
815 qrel
->r_offset
= rel
->r_offset
;
816 qrel
->r_info
= ELFW(R_INFO
)(esym_index
, R_X86_64_PC32
);
817 qrel
->r_addend
= *(int *)ptr
;
825 /* We've put the PLT slot offset into r_addend when generating
826 it, and that's what we must use as relocation value (adjusted
827 by section offset of course). */
828 val
= s1
->plt
->sh_addr
+ rel
->r_addend
;
834 diff
= (long long)val
- addr
;
835 if (diff
<= -2147483647 || diff
> 2147483647) {
836 tcc_error("internal error: relocation failed");
841 case R_X86_64_GLOB_DAT
:
842 case R_X86_64_JUMP_SLOT
:
843 /* They don't need addend */
844 *(addr_t
*)ptr
= val
- rel
->r_addend
;
846 case R_X86_64_GOTPCREL
:
847 *(int *)ptr
+= (s1
->got
->sh_addr
- addr
+
848 s1
->sym_attrs
[sym_index
].got_offset
- 4);
850 case R_X86_64_GOTTPOFF
:
851 *(int *)ptr
+= val
- s1
->got
->sh_addr
;
854 /* we load the got offset */
855 *(int *)ptr
+= s1
->sym_attrs
[sym_index
].got_offset
;
858 #error unsupported processor
862 /* if the relocation is allocated, we change its symbol table */
863 if (sr
->sh_flags
& SHF_ALLOC
)
864 sr
->link
= s1
->dynsym
;
867 /* relocate relocation table in 'sr' */
868 static void relocate_rel(TCCState
*s1
, Section
*sr
)
873 s
= s1
->sections
[sr
->sh_info
];
874 for_each_elem(sr
, 0, rel
, ElfW_Rel
)
875 rel
->r_offset
+= s
->sh_addr
;
878 /* count the number of dynamic relocations so that we can reserve
880 static int prepare_dynamic_rel(TCCState
*s1
, Section
*sr
)
883 int sym_index
, esym_index
, type
, count
;
886 for_each_elem(sr
, 0, rel
, ElfW_Rel
) {
887 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
888 type
= ELFW(R_TYPE
)(rel
->r_info
);
890 #if defined(TCC_TARGET_I386)
892 #elif defined(TCC_TARGET_X86_64)
899 #if defined(TCC_TARGET_I386)
901 #elif defined(TCC_TARGET_X86_64)
904 esym_index
= s1
->symtab_to_dynsym
[sym_index
];
913 /* allocate the section */
914 sr
->sh_flags
|= SHF_ALLOC
;
915 sr
->sh_size
= count
* sizeof(ElfW_Rel
);
920 static struct sym_attr
*alloc_sym_attr(TCCState
*s1
, int index
)
923 struct sym_attr
*tab
;
925 if (index
>= s1
->nb_sym_attrs
) {
926 /* find immediately bigger power of 2 and reallocate array */
930 tab
= tcc_realloc(s1
->sym_attrs
, n
* sizeof(*s1
->sym_attrs
));
932 memset(s1
->sym_attrs
+ s1
->nb_sym_attrs
, 0,
933 (n
- s1
->nb_sym_attrs
) * sizeof(*s1
->sym_attrs
));
934 s1
->nb_sym_attrs
= n
;
936 return &s1
->sym_attrs
[index
];
939 /* XXX: suppress that */
940 static void put32(unsigned char *p
, uint32_t val
)
948 #if defined(TCC_TARGET_I386) || defined(TCC_TARGET_ARM) || \
949 defined(TCC_TARGET_X86_64)
950 static uint32_t get32(unsigned char *p
)
952 return p
[0] | (p
[1] << 8) | (p
[2] << 16) | (p
[3] << 24);
956 static void build_got(TCCState
*s1
)
960 /* if no got, then create it */
961 s1
->got
= new_section(s1
, ".got", SHT_PROGBITS
, SHF_ALLOC
| SHF_WRITE
);
962 s1
->got
->sh_entsize
= 4;
963 add_elf_sym(symtab_section
, 0, 4, ELFW(ST_INFO
)(STB_GLOBAL
, STT_OBJECT
),
964 0, s1
->got
->sh_num
, "_GLOBAL_OFFSET_TABLE_");
965 ptr
= section_ptr_add(s1
->got
, 3 * PTR_SIZE
);
967 /* keep space for _DYNAMIC pointer, if present */
969 /* two dummy got entries */
973 /* keep space for _DYNAMIC pointer, if present */
976 /* two dummy got entries */
984 /* put a got or plt entry corresponding to a symbol in symtab_section. 'size'
985 and 'info' can be modifed if more precise info comes from the DLL.
986 Returns offset of GOT or PLT slot. */
987 static unsigned long put_got_entry(TCCState
*s1
,
988 int reloc_type
, unsigned long size
, int info
,
991 int index
, need_plt_entry
;
994 unsigned long offset
;
996 struct sym_attr
*symattr
;
1002 #ifdef TCC_TARGET_X86_64
1003 (reloc_type
== R_X86_64_JUMP_SLOT
);
1004 #elif defined(TCC_TARGET_I386)
1005 (reloc_type
== R_386_JMP_SLOT
);
1006 #elif defined(TCC_TARGET_ARM)
1007 (reloc_type
== R_ARM_JUMP_SLOT
);
1012 if (need_plt_entry
&& !s1
->plt
) {
1014 s1
->plt
= new_section(s1
, ".plt", SHT_PROGBITS
,
1015 SHF_ALLOC
| SHF_EXECINSTR
);
1016 s1
->plt
->sh_entsize
= 4;
1019 /* If a got/plt entry already exists for that symbol, no need to add one */
1020 if (sym_index
< s1
->nb_sym_attrs
) {
1021 if (need_plt_entry
&& s1
->sym_attrs
[sym_index
].plt_offset
)
1022 return s1
->sym_attrs
[sym_index
].plt_offset
;
1023 else if (!need_plt_entry
&& s1
->sym_attrs
[sym_index
].got_offset
)
1024 return s1
->sym_attrs
[sym_index
].got_offset
;
1027 symattr
= alloc_sym_attr(s1
, sym_index
);
1029 /* Only store the GOT offset if it's not generated for the PLT entry. */
1030 if (!need_plt_entry
)
1031 symattr
->got_offset
= s1
->got
->data_offset
;
1033 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
1034 name
= (char *) symtab_section
->link
->data
+ sym
->st_name
;
1035 offset
= sym
->st_value
;
1036 #if defined(TCC_TARGET_I386) || defined(TCC_TARGET_X86_64)
1037 if (need_plt_entry
) {
1041 unsigned long relofs
;
1043 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
1046 /* if we build a DLL, we add a %ebx offset */
1047 if (s1
->output_type
== TCC_OUTPUT_DLL
)
1053 /* add a PLT entry */
1055 if (plt
->data_offset
== 0) {
1056 /* first plt entry */
1057 p
= section_ptr_add(plt
, 16);
1058 p
[0] = 0xff; /* pushl got + PTR_SIZE */
1059 p
[1] = modrm
+ 0x10;
1060 put32(p
+ 2, PTR_SIZE
);
1061 p
[6] = 0xff; /* jmp *(got + PTR_SIZE * 2) */
1063 put32(p
+ 8, PTR_SIZE
* 2);
1066 /* The PLT slot refers to the relocation entry it needs
1067 via offset. The reloc entry is created below, so its
1068 offset is the current data_offset. */
1069 relofs
= s1
->got
->reloc
? s1
->got
->reloc
->data_offset
: 0;
1070 symattr
->plt_offset
= plt
->data_offset
;
1071 p
= section_ptr_add(plt
, 16);
1072 p
[0] = 0xff; /* jmp *(got + x) */
1074 put32(p
+ 2, s1
->got
->data_offset
);
1075 p
[6] = 0x68; /* push $xxx */
1076 #ifdef TCC_TARGET_X86_64
1077 /* On x86-64, the relocation is referred to by _index_. */
1078 put32(p
+ 7, relofs
/ sizeof (ElfW_Rel
));
1080 put32(p
+ 7, relofs
);
1082 p
[11] = 0xe9; /* jmp plt_start */
1083 put32(p
+ 12, -(plt
->data_offset
));
1085 /* If this was an UNDEF symbol set the offset in the
1086 dynsymtab to the PLT slot, so that PC32 relocs to it
1088 if (sym
->st_shndx
== SHN_UNDEF
)
1089 offset
= plt
->data_offset
- 16;
1091 #elif defined(TCC_TARGET_ARM)
1092 if (need_plt_entry
) {
1096 /* if we build a DLL, we add a %ebx offset */
1097 if (s1
->output_type
== TCC_OUTPUT_DLL
)
1098 tcc_error("DLLs unimplemented!");
1100 /* add a PLT entry */
1102 if (plt
->data_offset
== 0) {
1103 /* first plt entry */
1104 p
= section_ptr_add(plt
, 16);
1105 put32(p
, 0xe52de004); /* push {lr} */
1106 put32(p
+4, 0xe59fe010); /* ldr lr, [pc, #16] */
1107 put32(p
+8, 0xe08fe00e); /* add lr, pc, lr */
1108 put32(p
+12, 0xe5bef008); /* ldr pc, [lr, #8]! */
1111 symattr
->plt_offset
= plt
->data_offset
;
1112 if (symattr
->plt_thumb_stub
) {
1113 p
= section_ptr_add(plt
, 20);
1114 put32(p
, 0x4778); /* bx pc */
1115 put32(p
+2, 0x46c0); /* nop */
1118 p
= section_ptr_add(plt
, 16);
1119 put32(p
, 0xe59fc004); /* ldr ip, [pc, #4] ; GOT entry offset */
1120 put32(p
+4, 0xe08fc00c); /* add ip, pc, ip ; addr of GOT entry */
1121 put32(p
+8, 0xe59cf000); /* ldr pc, [ip] ; jump to GOT entry */
1122 put32(p
+12, s1
->got
->data_offset
); /* GOT entry off once patched */
1124 /* the symbol is modified so that it will be relocated to
1126 if (sym
->st_shndx
== SHN_UNDEF
)
1127 offset
= plt
->data_offset
- 16;
1129 #elif defined(TCC_TARGET_C67)
1131 tcc_error("C67 got not implemented");
1134 #error unsupported CPU
1137 /* XXX This might generate multiple syms for name. */
1138 index
= put_elf_sym(s1
->dynsym
, offset
,
1139 size
, info
, 0, sym
->st_shndx
, name
);
1140 /* Create the relocation (it's against the GOT for PLT
1142 put_elf_reloc(s1
->dynsym
, s1
->got
,
1143 s1
->got
->data_offset
,
1146 /* Without .dynsym (i.e. static link or memory output) we
1147 still need relocs against the generated got, so as to fill
1148 the entries with the symbol values (determined later). */
1149 put_elf_reloc(symtab_section
, s1
->got
,
1150 s1
->got
->data_offset
,
1151 reloc_type
, sym_index
);
1153 /* And now create the GOT slot itself. */
1154 ptr
= section_ptr_add(s1
->got
, PTR_SIZE
);
1157 return symattr
->plt_offset
;
1159 return symattr
->got_offset
;
1162 /* build GOT and PLT entries */
1163 ST_FUNC
void build_got_entries(TCCState
*s1
)
1168 int i
, type
, reloc_type
, sym_index
;
1170 for(i
= 1; i
< s1
->nb_sections
; i
++) {
1171 s
= s1
->sections
[i
];
1172 if (s
->sh_type
!= SHT_RELX
)
1174 /* no need to handle got relocations */
1175 if (s
->link
!= symtab_section
)
1177 for_each_elem(s
, 0, rel
, ElfW_Rel
) {
1178 type
= ELFW(R_TYPE
)(rel
->r_info
);
1180 #if defined(TCC_TARGET_I386)
1187 if (type
== R_386_GOT32
|| type
== R_386_PLT32
) {
1188 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
1189 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
1190 /* look at the symbol got offset. If none, then add one */
1191 if (type
== R_386_GOT32
)
1192 reloc_type
= R_386_GLOB_DAT
;
1194 reloc_type
= R_386_JMP_SLOT
;
1195 put_got_entry(s1
, reloc_type
, sym
->st_size
, sym
->st_info
,
1199 #elif defined(TCC_TARGET_ARM)
1209 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
1210 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
1211 if (type
!= R_ARM_GOTOFF
&& type
!= R_ARM_GOTPC
1212 && sym
->st_shndx
== SHN_UNDEF
) {
1214 /* look at the symbol got offset. If none, then add one */
1215 if (type
== R_ARM_GOT32
)
1216 reloc_type
= R_ARM_GLOB_DAT
;
1218 reloc_type
= R_ARM_JUMP_SLOT
;
1219 ofs
= put_got_entry(s1
, reloc_type
, sym
->st_size
,
1220 sym
->st_info
, sym_index
);
1222 printf ("maybegot: %s, %d, %d --> ofs=0x%x\n",
1223 (char *) symtab_section
->link
->data
+ sym
->st_name
,
1224 type
, sym
->st_shndx
, ofs
);
1226 if (type
!= R_ARM_GOT32
) {
1227 addr_t
*ptr
= (addr_t
*)(s1
->sections
[s
->sh_info
]->data
1229 /* x must be signed! */
1230 int x
= *ptr
& 0xffffff;
1236 printf ("insn=0x%x --> 0x%x (x==0x%x)\n", *ptr
,
1237 (*ptr
& 0xff000000) | x
, x
);
1239 *ptr
= (*ptr
& 0xff000000) | x
;
1243 case R_ARM_THM_JUMP24
:
1244 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
1245 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
1246 /* We are relocating a jump from thumb code to arm code */
1247 if (sym
->st_shndx
!= SHN_UNDEF
&& !(sym
->st_value
& 1)) {
1250 char *name
, buf
[1024];
1251 Section
*text_section
;
1253 name
= (char *) symtab_section
->link
->data
+ sym
->st_name
;
1254 text_section
= s1
->sections
[sym
->st_shndx
];
1255 /* Modify reloc to target a thumb stub to switch to ARM */
1256 snprintf(buf
, sizeof(buf
), "%s_from_thumb", name
);
1257 index
= put_elf_sym(symtab_section
,
1258 text_section
->data_offset
+ 1,
1259 sym
->st_size
, sym
->st_info
, 0,
1260 sym
->st_shndx
, buf
);
1261 rel
->r_info
= ELFW(R_INFO
)(index
, type
);
1262 /* Create a thumb stub fonction to switch to ARM mode */
1263 put_elf_reloc(symtab_section
, text_section
,
1264 text_section
->data_offset
+ 4, R_ARM_JUMP24
,
1266 p
= section_ptr_add(text_section
, 8);
1267 put32(p
, 0x4778); /* bx pc */
1268 put32(p
+2, 0x46c0); /* nop */
1269 put32(p
+4, 0xeafffffe); /* b $sym */
1271 #elif defined(TCC_TARGET_C67)
1278 if (type
== R_C60_GOT32
|| type
== R_C60_PLT32
) {
1279 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
1280 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
1281 /* look at the symbol got offset. If none, then add one */
1282 if (type
== R_C60_GOT32
)
1283 reloc_type
= R_C60_GLOB_DAT
;
1285 reloc_type
= R_C60_JMP_SLOT
;
1286 put_got_entry(s1
, reloc_type
, sym
->st_size
, sym
->st_info
,
1290 #elif defined(TCC_TARGET_X86_64)
1291 case R_X86_64_GOT32
:
1292 case R_X86_64_GOTTPOFF
:
1293 case R_X86_64_GOTPCREL
:
1294 case R_X86_64_PLT32
:
1295 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
1296 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
1297 if (type
== R_X86_64_PLT32
&&
1298 ELFW(ST_VISIBILITY
)(sym
->st_other
) != STV_DEFAULT
)
1300 rel
->r_info
= ELFW(R_INFO
)(sym_index
, R_X86_64_PC32
);
1306 if (type
== R_X86_64_GOT32
|| type
== R_X86_64_GOTPCREL
||
1307 type
== R_X86_64_PLT32
) {
1309 /* look at the symbol got offset. If none, then add one */
1310 if (type
== R_X86_64_GOT32
|| type
== R_X86_64_GOTPCREL
)
1311 reloc_type
= R_X86_64_GLOB_DAT
;
1313 reloc_type
= R_X86_64_JUMP_SLOT
;
1314 ofs
= put_got_entry(s1
, reloc_type
, sym
->st_size
,
1315 sym
->st_info
, sym_index
);
1316 if (type
== R_X86_64_PLT32
)
1317 /* We store the place of the generated PLT slot
1319 rel
->r_addend
+= ofs
;
1323 #error unsupported CPU
1332 ST_FUNC Section
*new_symtab(TCCState
*s1
,
1333 const char *symtab_name
, int sh_type
, int sh_flags
,
1334 const char *strtab_name
,
1335 const char *hash_name
, int hash_sh_flags
)
1337 Section
*symtab
, *strtab
, *hash
;
1338 int *ptr
, nb_buckets
;
1340 symtab
= new_section(s1
, symtab_name
, sh_type
, sh_flags
);
1341 symtab
->sh_entsize
= sizeof(ElfW(Sym
));
1342 strtab
= new_section(s1
, strtab_name
, SHT_STRTAB
, sh_flags
);
1343 put_elf_str(strtab
, "");
1344 symtab
->link
= strtab
;
1345 put_elf_sym(symtab
, 0, 0, 0, 0, 0, NULL
);
1349 hash
= new_section(s1
, hash_name
, SHT_HASH
, hash_sh_flags
);
1350 hash
->sh_entsize
= sizeof(int);
1351 symtab
->hash
= hash
;
1352 hash
->link
= symtab
;
1354 ptr
= section_ptr_add(hash
, (2 + nb_buckets
+ 1) * sizeof(int));
1355 ptr
[0] = nb_buckets
;
1357 memset(ptr
+ 2, 0, (nb_buckets
+ 1) * sizeof(int));
1361 /* put dynamic tag */
1362 static void put_dt(Section
*dynamic
, int dt
, addr_t val
)
1365 dyn
= section_ptr_add(dynamic
, sizeof(ElfW(Dyn
)));
1367 dyn
->d_un
.d_val
= val
;
1370 static void add_init_array_defines(TCCState
*s1
, const char *section_name
)
1374 char sym_start
[1024];
1377 snprintf(sym_start
, sizeof(sym_start
), "__%s_start", section_name
+ 1);
1378 snprintf(sym_end
, sizeof(sym_end
), "__%s_end", section_name
+ 1);
1380 s
= find_section(s1
, section_name
);
1385 end_offset
= s
->data_offset
;
1388 add_elf_sym(symtab_section
,
1390 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1391 s
->sh_num
, sym_start
);
1392 add_elf_sym(symtab_section
,
1394 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1395 s
->sh_num
, sym_end
);
1398 ST_FUNC
void tcc_add_bcheck(TCCState
*s1
)
1400 #ifdef CONFIG_TCC_BCHECK
1402 Section
*init_section
;
1403 unsigned char *pinit
;
1406 if (0 == s1
->do_bounds_check
)
1409 /* XXX: add an object file to do that */
1410 ptr
= section_ptr_add(bounds_section
, sizeof(unsigned long));
1412 add_elf_sym(symtab_section
, 0, 0,
1413 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1414 bounds_section
->sh_num
, "__bounds_start");
1415 #ifdef TCC_TARGET_I386
1416 if (s1
->output_type
!= TCC_OUTPUT_MEMORY
) {
1417 /* add 'call __bound_init()' in .init section */
1418 init_section
= find_section(s1
, ".init");
1419 pinit
= section_ptr_add(init_section
, 5);
1421 put32(pinit
+ 1, -4);
1422 sym_index
= find_elf_sym(symtab_section
, "__bound_init");
1423 put_elf_reloc(symtab_section
, init_section
,
1424 init_section
->data_offset
- 4, R_386_PC32
, sym_index
);
1430 static inline int tcc_add_support(TCCState
*s1
, const char *filename
)
1433 snprintf(buf
, sizeof(buf
), "%s/%s", s1
->tcc_lib_path
, filename
);
1434 return tcc_add_file(s1
, buf
);
1437 /* add tcc runtime libraries */
1438 ST_FUNC
void tcc_add_runtime(TCCState
*s1
)
1441 if (!s1
->nostdlib
) {
1442 tcc_add_library(s1
, "c");
1443 #ifdef CONFIG_USE_LIBGCC
1444 if (!s1
->static_link
) {
1445 tcc_add_file(s1
, TCC_LIBGCC
);
1446 tcc_add_support(s1
, "libtcc1.a");
1448 tcc_add_support(s1
, "libtcc1.a");
1450 tcc_add_support(s1
, "libtcc1.a");
1454 /* tcc_add_bcheck tries to relocate a call to __bound_init in _init so
1455 libtcc1.a must be loaded before for __bound_init to be defined and
1456 crtn.o must be loaded after to not finalize _init too early. */
1459 if (!s1
->nostdlib
) {
1460 /* add crt end if not memory output */
1461 if (s1
->output_type
!= TCC_OUTPUT_MEMORY
)
1462 tcc_add_crt(s1
, "crtn.o");
1466 /* add various standard linker symbols (must be done after the
1467 sections are filled (for example after allocating common
1469 ST_FUNC
void tcc_add_linker_symbols(TCCState
*s1
)
1475 add_elf_sym(symtab_section
,
1476 text_section
->data_offset
, 0,
1477 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1478 text_section
->sh_num
, "_etext");
1479 add_elf_sym(symtab_section
,
1480 data_section
->data_offset
, 0,
1481 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1482 data_section
->sh_num
, "_edata");
1483 add_elf_sym(symtab_section
,
1484 bss_section
->data_offset
, 0,
1485 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1486 bss_section
->sh_num
, "_end");
1487 /* horrible new standard ldscript defines */
1488 add_init_array_defines(s1
, ".preinit_array");
1489 add_init_array_defines(s1
, ".init_array");
1490 add_init_array_defines(s1
, ".fini_array");
1492 /* add start and stop symbols for sections whose name can be
1494 for(i
= 1; i
< s1
->nb_sections
; i
++) {
1495 s
= s1
->sections
[i
];
1496 if (s
->sh_type
== SHT_PROGBITS
&&
1497 (s
->sh_flags
& SHF_ALLOC
)) {
1501 /* check if section name can be expressed in C */
1507 if (!isid(ch
) && !isnum(ch
))
1511 snprintf(buf
, sizeof(buf
), "__start_%s", s
->name
);
1512 add_elf_sym(symtab_section
,
1514 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1516 snprintf(buf
, sizeof(buf
), "__stop_%s", s
->name
);
1517 add_elf_sym(symtab_section
,
1519 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1526 static void tcc_output_binary(TCCState
*s1
, FILE *f
,
1527 const int *sec_order
)
1530 int i
, offset
, size
;
1533 for(i
=1;i
<s1
->nb_sections
;i
++) {
1534 s
= s1
->sections
[sec_order
[i
]];
1535 if (s
->sh_type
!= SHT_NOBITS
&&
1536 (s
->sh_flags
& SHF_ALLOC
)) {
1537 while (offset
< s
->sh_offset
) {
1542 fwrite(s
->data
, 1, size
, f
);
1548 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1550 #define EXTRA_RELITEMS 14
1552 /* move the relocation value from .dynsym to .got */
1553 void patch_dynsym_undef(TCCState
*s1
, Section
*s
)
1555 uint32_t *gotd
= (void *)s1
->got
->data
;
1558 gotd
+= 3; /* dummy entries in .got */
1559 /* relocate symbols in .dynsym */
1560 for_each_elem(s
, 1, sym
, ElfW(Sym
)) {
1561 if (sym
->st_shndx
== SHN_UNDEF
) {
1562 *gotd
++ = sym
->st_value
+ 6; /* XXX 6 is magic ? */
1569 #define EXTRA_RELITEMS 9
1571 /* zero plt offsets of weak symbols in .dynsym */
1572 void patch_dynsym_undef(TCCState
*s1
, Section
*s
)
1576 for_each_elem(s
, 1, sym
, ElfW(Sym
))
1577 if (sym
->st_shndx
== SHN_UNDEF
&& ELFW(ST_BIND
)(sym
->st_info
) == STB_WEAK
)
1582 ST_FUNC
void fill_got_entry(TCCState
*s1
, ElfW_Rel
*rel
)
1584 int sym_index
= ELFW(R_SYM
) (rel
->r_info
);
1585 ElfW(Sym
) *sym
= &((ElfW(Sym
) *) symtab_section
->data
)[sym_index
];
1586 unsigned long offset
;
1588 if (sym_index
>= s1
->nb_sym_attrs
)
1590 offset
= s1
->sym_attrs
[sym_index
].got_offset
;
1591 section_reserve(s1
->got
, offset
+ PTR_SIZE
);
1592 #ifdef TCC_TARGET_X86_64
1593 /* only works for x86-64 */
1594 put32(s1
->got
->data
+ offset
+ 4, sym
->st_value
>> 32);
1596 put32(s1
->got
->data
+ offset
, sym
->st_value
& 0xffffffff);
1599 /* Perform relocation to GOT or PLT entries */
1600 ST_FUNC
void fill_got(TCCState
*s1
)
1606 for(i
= 1; i
< s1
->nb_sections
; i
++) {
1607 s
= s1
->sections
[i
];
1608 if (s
->sh_type
!= SHT_RELX
)
1610 /* no need to handle got relocations */
1611 if (s
->link
!= symtab_section
)
1613 for_each_elem(s
, 0, rel
, ElfW_Rel
) {
1614 switch (ELFW(R_TYPE
) (rel
->r_info
)) {
1615 case R_X86_64_GOT32
:
1616 case R_X86_64_GOTPCREL
:
1617 case R_X86_64_PLT32
:
1618 fill_got_entry(s1
, rel
);
1625 /* Bind symbols of executable: resolve undefined symbols from exported symbols
1626 in shared libraries and export non local defined symbols to shared libraries
1627 if -rdynamic switch was given on command line */
1628 static void bind_exe_dynsyms(TCCState
*s1
)
1631 int sym_index
, index
;
1632 ElfW(Sym
) *sym
, *esym
;
1635 /* Resolve undefined symbols from dynamic symbols. When there is a match:
1636 - if STT_FUNC or STT_GNU_IFUNC symbol -> add it in PLT
1637 - if STT_OBJECT symbol -> add it in .bss section with suitable reloc */
1638 for_each_elem(symtab_section
, 1, sym
, ElfW(Sym
)) {
1639 if (sym
->st_shndx
== SHN_UNDEF
) {
1640 name
= (char *) symtab_section
->link
->data
+ sym
->st_name
;
1641 sym_index
= find_elf_sym(s1
->dynsymtab_section
, name
);
1643 esym
= &((ElfW(Sym
) *)s1
->dynsymtab_section
->data
)[sym_index
];
1644 type
= ELFW(ST_TYPE
)(esym
->st_info
);
1645 if ((type
== STT_FUNC
) || (type
== STT_GNU_IFUNC
)) {
1646 /* Indirect functions shall have STT_FUNC type in executable
1647 * dynsym section. Indeed, a dlsym call following a lazy
1648 * resolution would pick the symbol value from the
1649 * executable dynsym entry which would contain the address
1650 * of the function wanted by the caller of dlsym instead of
1651 * the address of the function that would return that
1653 put_got_entry(s1
, R_JMP_SLOT
, esym
->st_size
,
1654 ELFW(ST_INFO
)(STB_GLOBAL
,STT_FUNC
),
1655 sym
- (ElfW(Sym
) *)symtab_section
->data
);
1656 } else if (type
== STT_OBJECT
) {
1657 unsigned long offset
;
1659 offset
= bss_section
->data_offset
;
1660 /* XXX: which alignment ? */
1661 offset
= (offset
+ 16 - 1) & -16;
1662 index
= put_elf_sym(s1
->dynsym
, offset
, esym
->st_size
,
1663 esym
->st_info
, 0, bss_section
->sh_num
,
1665 /* Ensure R_COPY works for weak symbol aliases */
1666 if (ELFW(ST_BIND
)(esym
->st_info
) == STB_WEAK
) {
1667 for_each_elem(s1
->dynsymtab_section
, 1, dynsym
, ElfW(Sym
)) {
1668 if ((dynsym
->st_value
== esym
->st_value
)
1669 && (ELFW(ST_BIND
)(dynsym
->st_info
) == STB_GLOBAL
)) {
1670 char *dynname
= (char *) s1
->dynsymtab_section
->link
->data
1672 put_elf_sym(s1
->dynsym
, offset
, dynsym
->st_size
,
1674 bss_section
->sh_num
, dynname
);
1679 put_elf_reloc(s1
->dynsym
, bss_section
,
1680 offset
, R_COPY
, index
);
1681 offset
+= esym
->st_size
;
1682 bss_section
->data_offset
= offset
;
1685 /* STB_WEAK undefined symbols are accepted */
1686 /* XXX: _fp_hw seems to be part of the ABI, so we ignore it */
1687 if (ELFW(ST_BIND
)(sym
->st_info
) == STB_WEAK
||
1688 !strcmp(name
, "_fp_hw")) {
1690 tcc_error_noabort("undefined symbol '%s'", name
);
1693 } else if (s1
->rdynamic
&& ELFW(ST_BIND
)(sym
->st_info
) != STB_LOCAL
) {
1694 /* if -rdynamic option, then export all non local symbols */
1695 name
= (char *) symtab_section
->link
->data
+ sym
->st_name
;
1696 put_elf_sym(s1
->dynsym
, sym
->st_value
, sym
->st_size
, sym
->st_info
,
1697 0, sym
->st_shndx
, name
);
1702 /* Bind symbols of libraries: export non local symbols of executable that
1703 resolve undefined symbols of shared libraries */
1704 static void bind_libs_dynsyms(TCCState
*s1
)
1708 ElfW(Sym
) *sym
, *esym
;
1710 /* now look at unresolved dynamic symbols and export
1711 corresponding symbol */
1712 for_each_elem(s1
->dynsymtab_section
, 1, esym
, ElfW(Sym
)) {
1713 if (esym
->st_shndx
== SHN_UNDEF
) {
1714 name
= (char *) s1
->dynsymtab_section
->link
->data
+ esym
->st_name
;
1715 sym_index
= find_elf_sym(symtab_section
, name
);
1717 /* XXX: avoid adding a symbol if already present because of
1719 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
1720 put_elf_sym(s1
->dynsym
, sym
->st_value
, sym
->st_size
,
1721 sym
->st_info
, 0, sym
->st_shndx
, name
);
1723 /* weak symbols can stay undefined */
1724 if (ELFW(ST_BIND
)(esym
->st_info
) != STB_WEAK
)
1725 tcc_warning("undefined dynamic symbol '%s'", name
);
1731 /* Export all non local symbols (for shared libraries) */
1732 static void export_global_syms(TCCState
*s1
)
1734 int nb_syms
, dynindex
, index
;
1738 nb_syms
= symtab_section
->data_offset
/ sizeof(ElfW(Sym
));
1739 s1
->symtab_to_dynsym
= tcc_mallocz(sizeof(int) * nb_syms
);
1740 for_each_elem(symtab_section
, 1, sym
, ElfW(Sym
)) {
1741 if (ELFW(ST_BIND
)(sym
->st_info
) != STB_LOCAL
) {
1742 name
= (char *) symtab_section
->link
->data
+ sym
->st_name
;
1743 dynindex
= put_elf_sym(s1
->dynsym
, sym
->st_value
, sym
->st_size
,
1744 sym
->st_info
, 0, sym
->st_shndx
, name
);
1745 index
= sym
- (ElfW(Sym
) *) symtab_section
->data
;
1746 s1
->symtab_to_dynsym
[index
] = dynindex
;
1751 /* relocate the PLT: compute addresses and offsets in the PLT now that final
1752 address for PLT and GOT are known (see fill_program_header) */
1753 ST_FUNC
void relocate_plt(TCCState
*s1
)
1761 p_end
= p
+ s1
->plt
->data_offset
;
1763 #if defined(TCC_TARGET_I386)
1764 put32(p
+ 2, get32(p
+ 2) + s1
->got
->sh_addr
);
1765 put32(p
+ 8, get32(p
+ 8) + s1
->got
->sh_addr
);
1768 put32(p
+ 2, get32(p
+ 2) + s1
->got
->sh_addr
);
1771 #elif defined(TCC_TARGET_X86_64)
1772 int x
= s1
->got
->sh_addr
- s1
->plt
->sh_addr
- 6;
1773 put32(p
+ 2, get32(p
+ 2) + x
);
1774 put32(p
+ 8, get32(p
+ 8) + x
- 6);
1777 put32(p
+ 2, get32(p
+ 2) + x
+ s1
->plt
->data
- p
);
1780 #elif defined(TCC_TARGET_ARM)
1782 x
=s1
->got
->sh_addr
- s1
->plt
->sh_addr
- 12;
1785 if (get32(p
) == 0x46c04778) /* PLT Thumb stub present */
1787 put32(p
+ 12, x
+ get32(p
+ 12) + s1
->plt
->data
- p
);
1790 #elif defined(TCC_TARGET_C67)
1793 #error unsupported CPU
1798 /* Allocate strings for section names and decide if an unallocated section
1801 NOTE: the strsec section comes last, so its size is also correct ! */
1802 static void alloc_sec_names(TCCState
*s1
, int file_type
, Section
*strsec
)
1807 /* Allocate strings for section names */
1808 for(i
= 1; i
< s1
->nb_sections
; i
++) {
1809 s
= s1
->sections
[i
];
1810 s
->sh_name
= put_elf_str(strsec
, s
->name
);
1811 /* when generating a DLL, we include relocations but we may
1813 if (file_type
== TCC_OUTPUT_DLL
&&
1814 s
->sh_type
== SHT_RELX
&&
1815 !(s
->sh_flags
& SHF_ALLOC
)) {
1816 /* gr: avoid bogus relocs for empty (debug) sections */
1817 if (s1
->sections
[s
->sh_info
]->sh_flags
& SHF_ALLOC
)
1818 prepare_dynamic_rel(s1
, s
);
1819 else if (s1
->do_debug
)
1820 s
->sh_size
= s
->data_offset
;
1821 } else if (s1
->do_debug
||
1822 file_type
== TCC_OUTPUT_OBJ
||
1823 (s
->sh_flags
& SHF_ALLOC
) ||
1824 i
== (s1
->nb_sections
- 1)) {
1825 /* we output all sections if debug or object file */
1826 s
->sh_size
= s
->data_offset
;
1831 /* Info to be copied in dynamic section */
1835 unsigned long dyn_rel_off
;
1838 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1844 /* Assign sections to segments and decide how are sections laid out when loaded
1845 in memory. This function also fills corresponding program headers. */
1846 static int layout_sections(TCCState
*s1
, ElfW(Phdr
) *phdr
, int phnum
,
1847 Section
*interp
, struct dyn_inf
*dyninf
,
1850 int i
, j
, k
, file_type
, sh_order_index
, file_offset
;
1851 unsigned long s_align
;
1857 file_type
= s1
->output_type
;
1860 if (s1
->output_format
== TCC_OUTPUT_FORMAT_ELF
)
1861 file_offset
= sizeof(ElfW(Ehdr
)) + phnum
* sizeof(ElfW(Phdr
));
1862 s_align
= ELF_PAGE_SIZE
;
1863 if (s1
->section_align
)
1864 s_align
= s1
->section_align
;
1867 if (s1
->has_text_addr
) {
1868 int a_offset
, p_offset
;
1869 addr
= s1
->text_addr
;
1870 /* we ensure that (addr % ELF_PAGE_SIZE) == file_offset %
1872 a_offset
= (int) (addr
& (s_align
- 1));
1873 p_offset
= file_offset
& (s_align
- 1);
1874 if (a_offset
< p_offset
)
1875 a_offset
+= s_align
;
1876 file_offset
+= (a_offset
- p_offset
);
1878 if (file_type
== TCC_OUTPUT_DLL
)
1881 addr
= ELF_START_ADDR
;
1882 /* compute address after headers */
1883 addr
+= (file_offset
& (s_align
- 1));
1887 /* Leave one program headers for the program interpreter and one for
1888 the program header table itself if needed. These are done later as
1889 they require section layout to be done first. */
1891 ph
+= 1 + HAVE_PHDR
;
1893 /* dynamic relocation table information, for .dynamic section */
1894 dyninf
->rel_addr
= dyninf
->rel_size
= 0;
1895 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1896 dyninf
->bss_addr
= dyninf
->bss_size
= 0;
1899 for(j
= 0; j
< 2; j
++) {
1900 ph
->p_type
= PT_LOAD
;
1902 ph
->p_flags
= PF_R
| PF_X
;
1904 ph
->p_flags
= PF_R
| PF_W
;
1905 ph
->p_align
= s_align
;
1907 /* Decide the layout of sections loaded in memory. This must
1908 be done before program headers are filled since they contain
1909 info about the layout. We do the following ordering: interp,
1910 symbol tables, relocations, progbits, nobits */
1911 /* XXX: do faster and simpler sorting */
1912 for(k
= 0; k
< 5; k
++) {
1913 for(i
= 1; i
< s1
->nb_sections
; i
++) {
1914 s
= s1
->sections
[i
];
1915 /* compute if section should be included */
1917 if ((s
->sh_flags
& (SHF_ALLOC
| SHF_WRITE
)) !=
1921 if ((s
->sh_flags
& (SHF_ALLOC
| SHF_WRITE
)) !=
1922 (SHF_ALLOC
| SHF_WRITE
))
1928 } else if (s
->sh_type
== SHT_DYNSYM
||
1929 s
->sh_type
== SHT_STRTAB
||
1930 s
->sh_type
== SHT_HASH
) {
1933 } else if (s
->sh_type
== SHT_RELX
) {
1936 } else if (s
->sh_type
== SHT_NOBITS
) {
1943 sec_order
[sh_order_index
++] = i
;
1945 /* section matches: we align it and add its size */
1947 addr
= (addr
+ s
->sh_addralign
- 1) &
1948 ~(s
->sh_addralign
- 1);
1949 file_offset
+= (int) ( addr
- tmp
);
1950 s
->sh_offset
= file_offset
;
1953 /* update program header infos */
1954 if (ph
->p_offset
== 0) {
1955 ph
->p_offset
= file_offset
;
1957 ph
->p_paddr
= ph
->p_vaddr
;
1959 /* update dynamic relocation infos */
1960 if (s
->sh_type
== SHT_RELX
) {
1961 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1962 if (!strcmp(strsec
->data
+ s
->sh_name
, ".rel.got")) {
1963 dyninf
->rel_addr
= addr
;
1964 dyninf
->rel_size
+= s
->sh_size
; /* XXX only first rel. */
1966 if (!strcmp(strsec
->data
+ s
->sh_name
, ".rel.bss")) {
1967 dyninf
->bss_addr
= addr
;
1968 dyninf
->bss_size
= s
->sh_size
; /* XXX only first rel. */
1971 if (dyninf
->rel_size
== 0)
1972 dyninf
->rel_addr
= addr
;
1973 dyninf
->rel_size
+= s
->sh_size
;
1977 if (s
->sh_type
!= SHT_NOBITS
)
1978 file_offset
+= s
->sh_size
;
1982 /* Make the first PT_LOAD segment include the program
1983 headers itself (and the ELF header as well), it'll
1984 come out with same memory use but will make various
1985 tools like binutils strip work better. */
1986 ph
->p_offset
&= ~(ph
->p_align
- 1);
1987 ph
->p_vaddr
&= ~(ph
->p_align
- 1);
1988 ph
->p_paddr
&= ~(ph
->p_align
- 1);
1990 ph
->p_filesz
= file_offset
- ph
->p_offset
;
1991 ph
->p_memsz
= addr
- ph
->p_vaddr
;
1994 if (s1
->output_format
== TCC_OUTPUT_FORMAT_ELF
) {
1995 /* if in the middle of a page, we duplicate the page in
1996 memory so that one copy is RX and the other is RW */
1997 if ((addr
& (s_align
- 1)) != 0)
2000 addr
= (addr
+ s_align
- 1) & ~(s_align
- 1);
2001 file_offset
= (file_offset
+ s_align
- 1) & ~(s_align
- 1);
2007 /* all other sections come after */
2008 for(i
= 1; i
< s1
->nb_sections
; i
++) {
2009 s
= s1
->sections
[i
];
2010 if (phnum
> 0 && (s
->sh_flags
& SHF_ALLOC
))
2012 sec_order
[sh_order_index
++] = i
;
2014 file_offset
= (file_offset
+ s
->sh_addralign
- 1) &
2015 ~(s
->sh_addralign
- 1);
2016 s
->sh_offset
= file_offset
;
2017 if (s
->sh_type
!= SHT_NOBITS
)
2018 file_offset
+= s
->sh_size
;
2024 static void fill_unloadable_phdr(ElfW(Phdr
) *phdr
, int phnum
, Section
*interp
,
2029 /* if interpreter, then add corresponding program header */
2035 int len
= phnum
* sizeof(ElfW(Phdr
));
2037 ph
->p_type
= PT_PHDR
;
2038 ph
->p_offset
= sizeof(ElfW(Ehdr
));
2039 ph
->p_vaddr
= interp
->sh_addr
- len
;
2040 ph
->p_paddr
= ph
->p_vaddr
;
2041 ph
->p_filesz
= ph
->p_memsz
= len
;
2042 ph
->p_flags
= PF_R
| PF_X
;
2043 ph
->p_align
= 4; /* interp->sh_addralign; */
2047 ph
->p_type
= PT_INTERP
;
2048 ph
->p_offset
= interp
->sh_offset
;
2049 ph
->p_vaddr
= interp
->sh_addr
;
2050 ph
->p_paddr
= ph
->p_vaddr
;
2051 ph
->p_filesz
= interp
->sh_size
;
2052 ph
->p_memsz
= interp
->sh_size
;
2054 ph
->p_align
= interp
->sh_addralign
;
2057 /* if dynamic section, then add corresponding program header */
2059 ph
= &phdr
[phnum
- 1];
2061 ph
->p_type
= PT_DYNAMIC
;
2062 ph
->p_offset
= dynamic
->sh_offset
;
2063 ph
->p_vaddr
= dynamic
->sh_addr
;
2064 ph
->p_paddr
= ph
->p_vaddr
;
2065 ph
->p_filesz
= dynamic
->sh_size
;
2066 ph
->p_memsz
= dynamic
->sh_size
;
2067 ph
->p_flags
= PF_R
| PF_W
;
2068 ph
->p_align
= dynamic
->sh_addralign
;
2072 /* Fill the dynamic section with tags describing the address and size of
2074 static void fill_dynamic(TCCState
*s1
, struct dyn_inf
*dyninf
)
2078 dynamic
= dyninf
->dynamic
;
2080 /* put dynamic section entries */
2081 dynamic
->data_offset
= dyninf
->dyn_rel_off
;
2082 put_dt(dynamic
, DT_HASH
, s1
->dynsym
->hash
->sh_addr
);
2083 put_dt(dynamic
, DT_STRTAB
, dyninf
->dynstr
->sh_addr
);
2084 put_dt(dynamic
, DT_SYMTAB
, s1
->dynsym
->sh_addr
);
2085 put_dt(dynamic
, DT_STRSZ
, dyninf
->dynstr
->data_offset
);
2086 put_dt(dynamic
, DT_SYMENT
, sizeof(ElfW(Sym
)));
2087 #ifdef TCC_TARGET_X86_64
2088 put_dt(dynamic
, DT_RELA
, dyninf
->rel_addr
);
2089 put_dt(dynamic
, DT_RELASZ
, dyninf
->rel_size
);
2090 put_dt(dynamic
, DT_RELAENT
, sizeof(ElfW_Rel
));
2092 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2093 put_dt(dynamic
, DT_PLTGOT
, s1
->got
->sh_addr
);
2094 put_dt(dynamic
, DT_PLTRELSZ
, dyninf
->rel_size
);
2095 put_dt(dynamic
, DT_JMPREL
, dyninf
->rel_addr
);
2096 put_dt(dynamic
, DT_PLTREL
, DT_REL
);
2097 put_dt(dynamic
, DT_REL
, dyninf
->bss_addr
);
2098 put_dt(dynamic
, DT_RELSZ
, dyninf
->bss_size
);
2100 put_dt(dynamic
, DT_REL
, dyninf
->rel_addr
);
2101 put_dt(dynamic
, DT_RELSZ
, dyninf
->rel_size
);
2102 put_dt(dynamic
, DT_RELENT
, sizeof(ElfW_Rel
));
2106 put_dt(dynamic
, DT_DEBUG
, 0);
2107 put_dt(dynamic
, DT_NULL
, 0);
2110 /* Relocate remaining sections and symbols (that is those not related to
2112 static int final_sections_reloc(TCCState
*s1
)
2117 relocate_syms(s1
, 0);
2119 if (s1
->nb_errors
!= 0)
2122 /* relocate sections */
2123 /* XXX: ignore sections with allocated relocations ? */
2124 for(i
= 1; i
< s1
->nb_sections
; i
++) {
2125 s
= s1
->sections
[i
];
2126 if (s
->reloc
&& s
!= s1
->got
)
2127 relocate_section(s1
, s
);
2130 /* relocate relocation entries if the relocation tables are
2131 allocated in the executable */
2132 for(i
= 1; i
< s1
->nb_sections
; i
++) {
2133 s
= s1
->sections
[i
];
2134 if ((s
->sh_flags
& SHF_ALLOC
) &&
2135 s
->sh_type
== SHT_RELX
) {
2136 relocate_rel(s1
, s
);
2142 /* Create an ELF file on disk.
2143 This function handle ELF specific layout requirements */
2144 static void tcc_output_elf(TCCState
*s1
, FILE *f
, int phnum
, ElfW(Phdr
) *phdr
,
2145 int file_offset
, int *sec_order
)
2147 int i
, shnum
, offset
, size
, file_type
;
2150 ElfW(Shdr
) shdr
, *sh
;
2152 file_type
= s1
->output_type
;
2153 shnum
= s1
->nb_sections
;
2155 memset(&ehdr
, 0, sizeof(ehdr
));
2158 ehdr
.e_phentsize
= sizeof(ElfW(Phdr
));
2159 ehdr
.e_phnum
= phnum
;
2160 ehdr
.e_phoff
= sizeof(ElfW(Ehdr
));
2164 file_offset
= (file_offset
+ 3) & -4;
2167 ehdr
.e_ident
[0] = ELFMAG0
;
2168 ehdr
.e_ident
[1] = ELFMAG1
;
2169 ehdr
.e_ident
[2] = ELFMAG2
;
2170 ehdr
.e_ident
[3] = ELFMAG3
;
2171 ehdr
.e_ident
[4] = ELFCLASSW
;
2172 ehdr
.e_ident
[5] = ELFDATA2LSB
;
2173 ehdr
.e_ident
[6] = EV_CURRENT
;
2174 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2175 ehdr
.e_ident
[EI_OSABI
] = ELFOSABI_FREEBSD
;
2177 #ifdef TCC_TARGET_ARM
2179 ehdr
.e_ident
[EI_OSABI
] = 0;
2180 ehdr
.e_flags
= EF_ARM_EABI_VER4
;
2181 if (file_type
== TCC_OUTPUT_EXE
|| file_type
== TCC_OUTPUT_DLL
)
2182 ehdr
.e_flags
|= EF_ARM_HASENTRY
;
2183 if (s1
->float_abi
== ARM_HARD_FLOAT
)
2184 ehdr
.e_flags
|= EF_ARM_VFP_FLOAT
;
2186 ehdr
.e_flags
|= EF_ARM_SOFT_FLOAT
;
2188 ehdr
.e_ident
[EI_OSABI
] = ELFOSABI_ARM
;
2193 case TCC_OUTPUT_EXE
:
2194 ehdr
.e_type
= ET_EXEC
;
2195 ehdr
.e_entry
= get_elf_sym_addr(s1
, "_start", 1);
2197 case TCC_OUTPUT_DLL
:
2198 ehdr
.e_type
= ET_DYN
;
2199 ehdr
.e_entry
= text_section
->sh_addr
; /* XXX: is it correct ? */
2201 case TCC_OUTPUT_OBJ
:
2202 ehdr
.e_type
= ET_REL
;
2205 ehdr
.e_machine
= EM_TCC_TARGET
;
2206 ehdr
.e_version
= EV_CURRENT
;
2207 ehdr
.e_shoff
= file_offset
;
2208 ehdr
.e_ehsize
= sizeof(ElfW(Ehdr
));
2209 ehdr
.e_shentsize
= sizeof(ElfW(Shdr
));
2210 ehdr
.e_shnum
= shnum
;
2211 ehdr
.e_shstrndx
= shnum
- 1;
2213 fwrite(&ehdr
, 1, sizeof(ElfW(Ehdr
)), f
);
2214 fwrite(phdr
, 1, phnum
* sizeof(ElfW(Phdr
)), f
);
2215 offset
= sizeof(ElfW(Ehdr
)) + phnum
* sizeof(ElfW(Phdr
));
2217 sort_syms(s1
, symtab_section
);
2218 for(i
= 1; i
< s1
->nb_sections
; i
++) {
2219 s
= s1
->sections
[sec_order
[i
]];
2220 if (s
->sh_type
!= SHT_NOBITS
) {
2221 if (s
->sh_type
== SHT_DYNSYM
)
2222 patch_dynsym_undef(s1
, s
);
2223 while (offset
< s
->sh_offset
) {
2228 fwrite(s
->data
, 1, size
, f
);
2233 /* output section headers */
2234 while (offset
< ehdr
.e_shoff
) {
2239 for(i
= 0; i
< s1
->nb_sections
; i
++) {
2241 memset(sh
, 0, sizeof(ElfW(Shdr
)));
2242 s
= s1
->sections
[i
];
2244 sh
->sh_name
= s
->sh_name
;
2245 sh
->sh_type
= s
->sh_type
;
2246 sh
->sh_flags
= s
->sh_flags
;
2247 sh
->sh_entsize
= s
->sh_entsize
;
2248 sh
->sh_info
= s
->sh_info
;
2250 sh
->sh_link
= s
->link
->sh_num
;
2251 sh
->sh_addralign
= s
->sh_addralign
;
2252 sh
->sh_addr
= s
->sh_addr
;
2253 sh
->sh_offset
= s
->sh_offset
;
2254 sh
->sh_size
= s
->sh_size
;
2256 fwrite(sh
, 1, sizeof(ElfW(Shdr
)), f
);
2260 /* Write an elf, coff or "binary" file */
2261 static int tcc_write_elf_file(TCCState
*s1
, const char *filename
, int phnum
,
2262 ElfW(Phdr
) *phdr
, int file_offset
, int *sec_order
)
2264 int fd
, mode
, file_type
;
2267 file_type
= s1
->output_type
;
2268 if (file_type
== TCC_OUTPUT_OBJ
)
2273 fd
= open(filename
, O_WRONLY
| O_CREAT
| O_TRUNC
| O_BINARY
, mode
);
2275 tcc_error_noabort("could not write '%s'", filename
);
2278 f
= fdopen(fd
, "wb");
2280 printf("<- %s\n", filename
);
2282 #ifdef TCC_TARGET_COFF
2283 if (s1
->output_format
== TCC_OUTPUT_FORMAT_COFF
)
2284 tcc_output_coff(s1
, f
);
2287 if (s1
->output_format
== TCC_OUTPUT_FORMAT_ELF
)
2288 tcc_output_elf(s1
, f
, phnum
, phdr
, file_offset
, sec_order
);
2290 tcc_output_binary(s1
, f
, sec_order
);
2296 /* Output an elf, coff or binary file */
2297 /* XXX: suppress unneeded sections */
2298 static int elf_output_file(TCCState
*s1
, const char *filename
)
2300 int i
, ret
, phnum
, shnum
, file_type
, file_offset
, *sec_order
;
2301 struct dyn_inf dyninf
;
2304 Section
*strsec
, *interp
, *dynamic
, *dynstr
;
2306 file_type
= s1
->output_type
;
2309 /* if linking, also link in runtime libraries (libc, libgcc, etc.) */
2310 if (file_type
!= TCC_OUTPUT_OBJ
) {
2311 tcc_add_runtime(s1
);
2316 interp
= dynamic
= dynstr
= NULL
; /* avoid warning */
2317 dyninf
.dyn_rel_off
= 0; /* avoid warning */
2319 if (file_type
!= TCC_OUTPUT_OBJ
) {
2320 relocate_common_syms();
2322 tcc_add_linker_symbols(s1
);
2324 if (!s1
->static_link
) {
2325 if (file_type
== TCC_OUTPUT_EXE
) {
2327 /* allow override the dynamic loader */
2328 const char *elfint
= getenv("LD_SO");
2330 elfint
= DEFAULT_ELFINTERP(s1
);
2331 /* add interpreter section only if executable */
2332 interp
= new_section(s1
, ".interp", SHT_PROGBITS
, SHF_ALLOC
);
2333 interp
->sh_addralign
= 1;
2334 ptr
= section_ptr_add(interp
, 1 + strlen(elfint
));
2335 strcpy(ptr
, elfint
);
2338 /* add dynamic symbol table */
2339 s1
->dynsym
= new_symtab(s1
, ".dynsym", SHT_DYNSYM
, SHF_ALLOC
,
2341 ".hash", SHF_ALLOC
);
2342 dynstr
= s1
->dynsym
->link
;
2344 /* add dynamic section */
2345 dynamic
= new_section(s1
, ".dynamic", SHT_DYNAMIC
,
2346 SHF_ALLOC
| SHF_WRITE
);
2347 dynamic
->link
= dynstr
;
2348 dynamic
->sh_entsize
= sizeof(ElfW(Dyn
));
2352 if (file_type
== TCC_OUTPUT_EXE
) {
2353 bind_exe_dynsyms(s1
);
2355 if (s1
->nb_errors
) {
2360 bind_libs_dynsyms(s1
);
2361 } else /* shared library case: simply export all global symbols */
2362 export_global_syms(s1
);
2364 build_got_entries(s1
);
2366 /* add a list of needed dlls */
2367 for(i
= 0; i
< s1
->nb_loaded_dlls
; i
++) {
2368 DLLReference
*dllref
= s1
->loaded_dlls
[i
];
2369 if (dllref
->level
== 0)
2370 put_dt(dynamic
, DT_NEEDED
, put_elf_str(dynstr
, dllref
->name
));
2374 put_dt(dynamic
, DT_RPATH
, put_elf_str(dynstr
, s1
->rpath
));
2376 /* XXX: currently, since we do not handle PIC code, we
2377 must relocate the readonly segments */
2378 if (file_type
== TCC_OUTPUT_DLL
) {
2380 put_dt(dynamic
, DT_SONAME
, put_elf_str(dynstr
, s1
->soname
));
2381 put_dt(dynamic
, DT_TEXTREL
, 0);
2385 put_dt(dynamic
, DT_SYMBOLIC
, 0);
2387 /* add necessary space for other entries */
2388 dyninf
.dyn_rel_off
= dynamic
->data_offset
;
2389 dynamic
->data_offset
+= sizeof(ElfW(Dyn
)) * EXTRA_RELITEMS
;
2391 /* still need to build got entries in case of static link */
2392 build_got_entries(s1
);
2396 /* we add a section for symbols */
2397 strsec
= new_section(s1
, ".shstrtab", SHT_STRTAB
, 0);
2398 put_elf_str(strsec
, "");
2400 /* compute number of sections */
2401 shnum
= s1
->nb_sections
;
2403 /* this array is used to reorder sections in the output file */
2404 sec_order
= tcc_malloc(sizeof(int) * shnum
);
2407 /* compute number of program headers */
2410 case TCC_OUTPUT_OBJ
:
2413 case TCC_OUTPUT_EXE
:
2414 if (!s1
->static_link
)
2415 phnum
= 4 + HAVE_PHDR
;
2419 case TCC_OUTPUT_DLL
:
2424 /* Allocate strings for section names */
2425 alloc_sec_names(s1
, file_type
, strsec
);
2427 /* allocate program segment headers */
2428 phdr
= tcc_mallocz(phnum
* sizeof(ElfW(Phdr
)));
2430 /* compute section to program header mapping */
2431 file_offset
= layout_sections(s1
, phdr
, phnum
, interp
, &dyninf
, sec_order
);
2433 /* Fill remaining program header and finalize relocation related to dynamic
2436 fill_unloadable_phdr(phdr
, phnum
, interp
, dynamic
);
2438 dyninf
.dynamic
= dynamic
;
2439 dyninf
.dynstr
= dynstr
;
2441 fill_dynamic(s1
, &dyninf
);
2443 /* put in GOT the dynamic section address and relocate PLT */
2444 put32(s1
->got
->data
, dynamic
->sh_addr
);
2445 if (file_type
== TCC_OUTPUT_EXE
2446 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
2447 || file_type
== TCC_OUTPUT_DLL
2452 /* relocate symbols in .dynsym now that final addresses are known */
2453 for_each_elem(s1
->dynsym
, 1, sym
, ElfW(Sym
)) {
2454 /* relocate to PLT if symbol corresponds to a PLT entry */
2455 if (sym
->st_shndx
== SHN_UNDEF
) {
2457 sym
->st_value
+= s1
->plt
->sh_addr
;
2458 } else if (sym
->st_shndx
< SHN_LORESERVE
) {
2459 /* do symbol relocation */
2460 sym
->st_value
+= s1
->sections
[sym
->st_shndx
]->sh_addr
;
2466 /* if building executable or DLL, then relocate each section
2467 except the GOT which is already relocated */
2468 if (file_type
!= TCC_OUTPUT_OBJ
) {
2469 ret
= final_sections_reloc(s1
);
2474 /* Perform relocation to GOT or PLT entries */
2475 if (file_type
== TCC_OUTPUT_EXE
&& s1
->static_link
)
2478 /* Create the ELF file with name 'filename' */
2479 ret
= tcc_write_elf_file(s1
, filename
, phnum
, phdr
, file_offset
, sec_order
);
2481 tcc_free(s1
->symtab_to_dynsym
);
2482 tcc_free(sec_order
);
2484 tcc_free(s1
->sym_attrs
);
2485 s1
->sym_attrs
= NULL
;
2489 LIBTCCAPI
int tcc_output_file(TCCState
*s
, const char *filename
)
2492 #ifdef TCC_TARGET_PE
2493 if (s
->output_type
!= TCC_OUTPUT_OBJ
) {
2494 ret
= pe_output_file(s
, filename
);
2497 ret
= elf_output_file(s
, filename
);
2501 static void *load_data(int fd
, unsigned long file_offset
, unsigned long size
)
2505 data
= tcc_malloc(size
);
2506 lseek(fd
, file_offset
, SEEK_SET
);
2507 read(fd
, data
, size
);
2511 typedef struct SectionMergeInfo
{
2512 Section
*s
; /* corresponding existing section */
2513 unsigned long offset
; /* offset of the new section in the existing section */
2514 uint8_t new_section
; /* true if section 's' was added */
2515 uint8_t link_once
; /* true if link once section */
2518 /* load an object file and merge it with current files */
2519 /* XXX: handle correctly stab (debug) info */
2520 ST_FUNC
int tcc_load_object_file(TCCState
*s1
,
2521 int fd
, unsigned long file_offset
)
2524 ElfW(Shdr
) *shdr
, *sh
;
2525 int size
, i
, j
, offset
, offseti
, nb_syms
, sym_index
, ret
;
2526 unsigned char *strsec
, *strtab
;
2527 int *old_to_new_syms
;
2528 char *sh_name
, *name
;
2529 SectionMergeInfo
*sm_table
, *sm
;
2530 ElfW(Sym
) *sym
, *symtab
;
2537 stab_index
= stabstr_index
= 0;
2539 if (read(fd
, &ehdr
, sizeof(ehdr
)) != sizeof(ehdr
))
2541 if (ehdr
.e_ident
[0] != ELFMAG0
||
2542 ehdr
.e_ident
[1] != ELFMAG1
||
2543 ehdr
.e_ident
[2] != ELFMAG2
||
2544 ehdr
.e_ident
[3] != ELFMAG3
)
2546 /* test if object file */
2547 if (ehdr
.e_type
!= ET_REL
)
2549 /* test CPU specific stuff */
2550 if (ehdr
.e_ident
[5] != ELFDATA2LSB
||
2551 ehdr
.e_machine
!= EM_TCC_TARGET
) {
2553 tcc_error_noabort("invalid object file");
2557 shdr
= load_data(fd
, file_offset
+ ehdr
.e_shoff
,
2558 sizeof(ElfW(Shdr
)) * ehdr
.e_shnum
);
2559 sm_table
= tcc_mallocz(sizeof(SectionMergeInfo
) * ehdr
.e_shnum
);
2561 /* load section names */
2562 sh
= &shdr
[ehdr
.e_shstrndx
];
2563 strsec
= load_data(fd
, file_offset
+ sh
->sh_offset
, sh
->sh_size
);
2565 /* load symtab and strtab */
2566 old_to_new_syms
= NULL
;
2570 for(i
= 1; i
< ehdr
.e_shnum
; i
++) {
2572 if (sh
->sh_type
== SHT_SYMTAB
) {
2574 tcc_error_noabort("object must contain only one symtab");
2579 nb_syms
= sh
->sh_size
/ sizeof(ElfW(Sym
));
2580 symtab
= load_data(fd
, file_offset
+ sh
->sh_offset
, sh
->sh_size
);
2581 sm_table
[i
].s
= symtab_section
;
2583 /* now load strtab */
2584 sh
= &shdr
[sh
->sh_link
];
2585 strtab
= load_data(fd
, file_offset
+ sh
->sh_offset
, sh
->sh_size
);
2589 /* now examine each section and try to merge its content with the
2591 for(i
= 1; i
< ehdr
.e_shnum
; i
++) {
2592 /* no need to examine section name strtab */
2593 if (i
== ehdr
.e_shstrndx
)
2596 sh_name
= (char *) strsec
+ sh
->sh_name
;
2597 /* ignore sections types we do not handle */
2598 if (sh
->sh_type
!= SHT_PROGBITS
&&
2599 sh
->sh_type
!= SHT_RELX
&&
2601 sh
->sh_type
!= SHT_ARM_EXIDX
&&
2603 sh
->sh_type
!= SHT_NOBITS
&&
2604 sh
->sh_type
!= SHT_PREINIT_ARRAY
&&
2605 sh
->sh_type
!= SHT_INIT_ARRAY
&&
2606 sh
->sh_type
!= SHT_FINI_ARRAY
&&
2607 strcmp(sh_name
, ".stabstr")
2610 if (sh
->sh_addralign
< 1)
2611 sh
->sh_addralign
= 1;
2612 /* find corresponding section, if any */
2613 for(j
= 1; j
< s1
->nb_sections
;j
++) {
2614 s
= s1
->sections
[j
];
2615 if (!strcmp(s
->name
, sh_name
)) {
2616 if (!strncmp(sh_name
, ".gnu.linkonce",
2617 sizeof(".gnu.linkonce") - 1)) {
2618 /* if a 'linkonce' section is already present, we
2619 do not add it again. It is a little tricky as
2620 symbols can still be defined in
2622 sm_table
[i
].link_once
= 1;
2629 /* not found: create new section */
2630 s
= new_section(s1
, sh_name
, sh
->sh_type
, sh
->sh_flags
);
2631 /* take as much info as possible from the section. sh_link and
2632 sh_info will be updated later */
2633 s
->sh_addralign
= sh
->sh_addralign
;
2634 s
->sh_entsize
= sh
->sh_entsize
;
2635 sm_table
[i
].new_section
= 1;
2637 if (sh
->sh_type
!= s
->sh_type
) {
2638 tcc_error_noabort("invalid section type");
2642 /* align start of section */
2643 offset
= s
->data_offset
;
2645 if (0 == strcmp(sh_name
, ".stab")) {
2649 if (0 == strcmp(sh_name
, ".stabstr")) {
2654 size
= sh
->sh_addralign
- 1;
2655 offset
= (offset
+ size
) & ~size
;
2656 if (sh
->sh_addralign
> s
->sh_addralign
)
2657 s
->sh_addralign
= sh
->sh_addralign
;
2658 s
->data_offset
= offset
;
2660 sm_table
[i
].offset
= offset
;
2662 /* concatenate sections */
2664 if (sh
->sh_type
!= SHT_NOBITS
) {
2666 lseek(fd
, file_offset
+ sh
->sh_offset
, SEEK_SET
);
2667 ptr
= section_ptr_add(s
, size
);
2668 read(fd
, ptr
, size
);
2670 s
->data_offset
+= size
;
2675 /* gr relocate stab strings */
2676 if (stab_index
&& stabstr_index
) {
2679 s
= sm_table
[stab_index
].s
;
2680 a
= (Stab_Sym
*)(s
->data
+ sm_table
[stab_index
].offset
);
2681 b
= (Stab_Sym
*)(s
->data
+ s
->data_offset
);
2682 o
= sm_table
[stabstr_index
].offset
;
2684 a
->n_strx
+= o
, a
++;
2687 /* second short pass to update sh_link and sh_info fields of new
2689 for(i
= 1; i
< ehdr
.e_shnum
; i
++) {
2691 if (!s
|| !sm_table
[i
].new_section
)
2694 if (sh
->sh_link
> 0)
2695 s
->link
= sm_table
[sh
->sh_link
].s
;
2696 if (sh
->sh_type
== SHT_RELX
) {
2697 s
->sh_info
= sm_table
[sh
->sh_info
].s
->sh_num
;
2698 /* update backward link */
2699 s1
->sections
[s
->sh_info
]->reloc
= s
;
2704 /* resolve symbols */
2705 old_to_new_syms
= tcc_mallocz(nb_syms
* sizeof(int));
2708 for(i
= 1; i
< nb_syms
; i
++, sym
++) {
2709 if (sym
->st_shndx
!= SHN_UNDEF
&&
2710 sym
->st_shndx
< SHN_LORESERVE
) {
2711 sm
= &sm_table
[sym
->st_shndx
];
2712 if (sm
->link_once
) {
2713 /* if a symbol is in a link once section, we use the
2714 already defined symbol. It is very important to get
2715 correct relocations */
2716 if (ELFW(ST_BIND
)(sym
->st_info
) != STB_LOCAL
) {
2717 name
= (char *) strtab
+ sym
->st_name
;
2718 sym_index
= find_elf_sym(symtab_section
, name
);
2720 old_to_new_syms
[i
] = sym_index
;
2724 /* if no corresponding section added, no need to add symbol */
2727 /* convert section number */
2728 sym
->st_shndx
= sm
->s
->sh_num
;
2730 sym
->st_value
+= sm
->offset
;
2733 name
= (char *) strtab
+ sym
->st_name
;
2734 sym_index
= add_elf_sym(symtab_section
, sym
->st_value
, sym
->st_size
,
2735 sym
->st_info
, sym
->st_other
,
2736 sym
->st_shndx
, name
);
2737 old_to_new_syms
[i
] = sym_index
;
2740 /* third pass to patch relocation entries */
2741 for(i
= 1; i
< ehdr
.e_shnum
; i
++) {
2746 offset
= sm_table
[i
].offset
;
2747 switch(s
->sh_type
) {
2749 /* take relocation offset information */
2750 offseti
= sm_table
[sh
->sh_info
].offset
;
2751 for_each_elem(s
, (offset
/ sizeof(*rel
)), rel
, ElfW_Rel
) {
2754 /* convert symbol index */
2755 type
= ELFW(R_TYPE
)(rel
->r_info
);
2756 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
2757 /* NOTE: only one symtab assumed */
2758 if (sym_index
>= nb_syms
)
2760 sym_index
= old_to_new_syms
[sym_index
];
2761 /* ignore link_once in rel section. */
2762 if (!sym_index
&& !sm
->link_once
2763 #ifdef TCC_TARGET_ARM
2764 && type
!= R_ARM_V4BX
2768 tcc_error_noabort("Invalid relocation entry [%2d] '%s' @ %.8x",
2769 i
, strsec
+ sh
->sh_name
, rel
->r_offset
);
2772 rel
->r_info
= ELFW(R_INFO
)(sym_index
, type
);
2773 /* offset the relocation offset */
2774 rel
->r_offset
+= offseti
;
2775 #ifdef TCC_TARGET_ARM
2776 /* Jumps and branches from a Thumb code to a PLT entry need
2777 special handling since PLT entries are ARM code.
2778 Unconditional bl instructions referencing PLT entries are
2779 handled by converting these instructions into blx
2780 instructions. Other case of instructions referencing a PLT
2781 entry require to add a Thumb stub before the PLT entry to
2782 switch to ARM mode. We set bit plt_thumb_stub of the
2783 attribute of a symbol to indicate such a case. */
2784 if (type
== R_ARM_THM_JUMP24
)
2785 alloc_sym_attr(s1
, sym_index
)->plt_thumb_stub
= 1;
2798 tcc_free(old_to_new_syms
);
2805 typedef struct ArchiveHeader
{
2806 char ar_name
[16]; /* name of this member */
2807 char ar_date
[12]; /* file mtime */
2808 char ar_uid
[6]; /* owner uid; printed as decimal */
2809 char ar_gid
[6]; /* owner gid; printed as decimal */
2810 char ar_mode
[8]; /* file mode, printed as octal */
2811 char ar_size
[10]; /* file size, printed as decimal */
2812 char ar_fmag
[2]; /* should contain ARFMAG */
2815 static int get_be32(const uint8_t *b
)
2817 return b
[3] | (b
[2] << 8) | (b
[1] << 16) | (b
[0] << 24);
2820 /* load only the objects which resolve undefined symbols */
2821 static int tcc_load_alacarte(TCCState
*s1
, int fd
, int size
)
2823 int i
, bound
, nsyms
, sym_index
, off
, ret
;
2825 const char *ar_names
, *p
;
2826 const uint8_t *ar_index
;
2829 data
= tcc_malloc(size
);
2830 if (read(fd
, data
, size
) != size
)
2832 nsyms
= get_be32(data
);
2833 ar_index
= data
+ 4;
2834 ar_names
= (char *) ar_index
+ nsyms
* 4;
2838 for(p
= ar_names
, i
= 0; i
< nsyms
; i
++, p
+= strlen(p
)+1) {
2839 sym_index
= find_elf_sym(symtab_section
, p
);
2841 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
2842 if(sym
->st_shndx
== SHN_UNDEF
) {
2843 off
= get_be32(ar_index
+ i
* 4) + sizeof(ArchiveHeader
);
2845 lseek(fd
, off
, SEEK_SET
);
2846 if(tcc_load_object_file(s1
, fd
, off
) < 0) {
2861 /* load a '.a' file */
2862 ST_FUNC
int tcc_load_archive(TCCState
*s1
, int fd
)
2869 unsigned long file_offset
;
2871 /* skip magic which was already checked */
2872 read(fd
, magic
, sizeof(magic
));
2875 len
= read(fd
, &hdr
, sizeof(hdr
));
2878 if (len
!= sizeof(hdr
)) {
2879 tcc_error_noabort("invalid archive");
2882 memcpy(ar_size
, hdr
.ar_size
, sizeof(hdr
.ar_size
));
2883 ar_size
[sizeof(hdr
.ar_size
)] = '\0';
2884 size
= strtol(ar_size
, NULL
, 0);
2885 memcpy(ar_name
, hdr
.ar_name
, sizeof(hdr
.ar_name
));
2886 for(i
= sizeof(hdr
.ar_name
) - 1; i
>= 0; i
--) {
2887 if (ar_name
[i
] != ' ')
2890 ar_name
[i
+ 1] = '\0';
2891 file_offset
= lseek(fd
, 0, SEEK_CUR
);
2893 size
= (size
+ 1) & ~1;
2894 if (!strcmp(ar_name
, "/")) {
2895 /* coff symbol table : we handle it */
2896 if(s1
->alacarte_link
)
2897 return tcc_load_alacarte(s1
, fd
, size
);
2898 } else if (!strcmp(ar_name
, "//") ||
2899 !strcmp(ar_name
, "__.SYMDEF") ||
2900 !strcmp(ar_name
, "__.SYMDEF/") ||
2901 !strcmp(ar_name
, "ARFILENAMES/")) {
2902 /* skip symbol table or archive names */
2904 if (tcc_load_object_file(s1
, fd
, file_offset
) < 0)
2907 lseek(fd
, file_offset
+ size
, SEEK_SET
);
2912 #ifndef TCC_TARGET_PE
2913 /* load a DLL and all referenced DLLs. 'level = 0' means that the DLL
2914 is referenced by the user (so it should be added as DT_NEEDED in
2915 the generated ELF file) */
2916 ST_FUNC
int tcc_load_dll(TCCState
*s1
, int fd
, const char *filename
, int level
)
2919 ElfW(Shdr
) *shdr
, *sh
, *sh1
;
2920 int i
, j
, nb_syms
, nb_dts
, sym_bind
, ret
;
2921 ElfW(Sym
) *sym
, *dynsym
;
2922 ElfW(Dyn
) *dt
, *dynamic
;
2923 unsigned char *dynstr
;
2924 const char *name
, *soname
;
2925 DLLReference
*dllref
;
2927 read(fd
, &ehdr
, sizeof(ehdr
));
2929 /* test CPU specific stuff */
2930 if (ehdr
.e_ident
[5] != ELFDATA2LSB
||
2931 ehdr
.e_machine
!= EM_TCC_TARGET
) {
2932 tcc_error_noabort("bad architecture");
2937 shdr
= load_data(fd
, ehdr
.e_shoff
, sizeof(ElfW(Shdr
)) * ehdr
.e_shnum
);
2939 /* load dynamic section and dynamic symbols */
2943 dynsym
= NULL
; /* avoid warning */
2944 dynstr
= NULL
; /* avoid warning */
2945 for(i
= 0, sh
= shdr
; i
< ehdr
.e_shnum
; i
++, sh
++) {
2946 switch(sh
->sh_type
) {
2948 nb_dts
= sh
->sh_size
/ sizeof(ElfW(Dyn
));
2949 dynamic
= load_data(fd
, sh
->sh_offset
, sh
->sh_size
);
2952 nb_syms
= sh
->sh_size
/ sizeof(ElfW(Sym
));
2953 dynsym
= load_data(fd
, sh
->sh_offset
, sh
->sh_size
);
2954 sh1
= &shdr
[sh
->sh_link
];
2955 dynstr
= load_data(fd
, sh1
->sh_offset
, sh1
->sh_size
);
2962 /* compute the real library name */
2963 soname
= tcc_basename(filename
);
2965 for(i
= 0, dt
= dynamic
; i
< nb_dts
; i
++, dt
++) {
2966 if (dt
->d_tag
== DT_SONAME
) {
2967 soname
= (char *) dynstr
+ dt
->d_un
.d_val
;
2971 /* if the dll is already loaded, do not load it */
2972 for(i
= 0; i
< s1
->nb_loaded_dlls
; i
++) {
2973 dllref
= s1
->loaded_dlls
[i
];
2974 if (!strcmp(soname
, dllref
->name
)) {
2975 /* but update level if needed */
2976 if (level
< dllref
->level
)
2977 dllref
->level
= level
;
2983 /* add the dll and its level */
2984 dllref
= tcc_mallocz(sizeof(DLLReference
) + strlen(soname
));
2985 dllref
->level
= level
;
2986 strcpy(dllref
->name
, soname
);
2987 dynarray_add((void ***)&s1
->loaded_dlls
, &s1
->nb_loaded_dlls
, dllref
);
2989 /* add dynamic symbols in dynsym_section */
2990 for(i
= 1, sym
= dynsym
+ 1; i
< nb_syms
; i
++, sym
++) {
2991 sym_bind
= ELFW(ST_BIND
)(sym
->st_info
);
2992 if (sym_bind
== STB_LOCAL
)
2994 name
= (char *) dynstr
+ sym
->st_name
;
2995 add_elf_sym(s1
->dynsymtab_section
, sym
->st_value
, sym
->st_size
,
2996 sym
->st_info
, sym
->st_other
, sym
->st_shndx
, name
);
2999 /* load all referenced DLLs */
3000 for(i
= 0, dt
= dynamic
; i
< nb_dts
; i
++, dt
++) {
3003 name
= (char *) dynstr
+ dt
->d_un
.d_val
;
3004 for(j
= 0; j
< s1
->nb_loaded_dlls
; j
++) {
3005 dllref
= s1
->loaded_dlls
[j
];
3006 if (!strcmp(name
, dllref
->name
))
3007 goto already_loaded
;
3009 if (tcc_add_dll(s1
, name
, AFF_REFERENCED_DLL
) < 0) {
3010 tcc_error_noabort("referenced dll '%s' not found", name
);
3027 #define LD_TOK_NAME 256
3028 #define LD_TOK_EOF (-1)
3030 /* return next ld script token */
3031 static int ld_next(TCCState
*s1
, char *name
, int name_size
)
3049 file
->buf_ptr
= parse_comment(file
->buf_ptr
);
3050 ch
= file
->buf_ptr
[0];
3058 /* case 'a' ... 'z': */
3085 /* case 'A' ... 'z': */
3120 if (!((ch
>= 'a' && ch
<= 'z') ||
3121 (ch
>= 'A' && ch
<= 'Z') ||
3122 (ch
>= '0' && ch
<= '9') ||
3123 strchr("/.-_+=$:\\,~", ch
)))
3125 if ((q
- name
) < name_size
- 1) {
3144 static int ld_add_file(TCCState
*s1
, const char filename
[])
3148 ret
= tcc_add_file_internal(s1
, filename
, 0);
3150 ret
= tcc_add_dll(s1
, filename
, 0);
3154 static inline int new_undef_syms(void)
3157 ret
= new_undef_sym
;
3162 static int ld_add_file_list(TCCState
*s1
, const char *cmd
, int as_needed
)
3164 char filename
[1024], libname
[1024];
3165 int t
, group
, nblibs
= 0, ret
= 0;
3168 group
= !strcmp(cmd
, "GROUP");
3171 t
= ld_next(s1
, filename
, sizeof(filename
));
3174 t
= ld_next(s1
, filename
, sizeof(filename
));
3177 if (t
== LD_TOK_EOF
) {
3178 tcc_error_noabort("unexpected end of file");
3180 goto lib_parse_error
;
3181 } else if (t
== ')') {
3183 } else if (t
== '-') {
3184 t
= ld_next(s1
, filename
, sizeof(filename
));
3185 if ((t
!= LD_TOK_NAME
) || (filename
[0] != 'l')) {
3186 tcc_error_noabort("library name expected");
3188 goto lib_parse_error
;
3190 pstrcpy(libname
, sizeof libname
, &filename
[1]);
3191 if (s1
->static_link
) {
3192 snprintf(filename
, sizeof filename
, "lib%s.a", libname
);
3194 snprintf(filename
, sizeof filename
, "lib%s.so", libname
);
3196 } else if (t
!= LD_TOK_NAME
) {
3197 tcc_error_noabort("filename expected");
3199 goto lib_parse_error
;
3201 if (!strcmp(filename
, "AS_NEEDED")) {
3202 ret
= ld_add_file_list(s1
, cmd
, 1);
3204 goto lib_parse_error
;
3206 /* TODO: Implement AS_NEEDED support. Ignore it for now */
3208 ret
= ld_add_file(s1
, filename
);
3210 goto lib_parse_error
;
3212 /* Add the filename *and* the libname to avoid future conversions */
3213 dynarray_add((void ***) &libs
, &nblibs
, tcc_strdup(filename
));
3214 if (libname
[0] != '\0')
3215 dynarray_add((void ***) &libs
, &nblibs
, tcc_strdup(libname
));
3219 t
= ld_next(s1
, filename
, sizeof(filename
));
3221 t
= ld_next(s1
, filename
, sizeof(filename
));
3224 if (group
&& !as_needed
) {
3225 while (new_undef_syms()) {
3228 for (i
= 0; i
< nblibs
; i
++)
3229 ld_add_file(s1
, libs
[i
]);
3233 dynarray_reset(&libs
, &nblibs
);
3237 /* interpret a subset of GNU ldscripts to handle the dummy libc.so
3239 ST_FUNC
int tcc_load_ldscript(TCCState
*s1
)
3242 char filename
[1024];
3245 ch
= file
->buf_ptr
[0];
3248 t
= ld_next(s1
, cmd
, sizeof(cmd
));
3249 if (t
== LD_TOK_EOF
)
3251 else if (t
!= LD_TOK_NAME
)
3253 if (!strcmp(cmd
, "INPUT") ||
3254 !strcmp(cmd
, "GROUP")) {
3255 ret
= ld_add_file_list(s1
, cmd
, 0);
3258 } else if (!strcmp(cmd
, "OUTPUT_FORMAT") ||
3259 !strcmp(cmd
, "TARGET")) {
3260 /* ignore some commands */
3261 t
= ld_next(s1
, cmd
, sizeof(cmd
));
3265 t
= ld_next(s1
, filename
, sizeof(filename
));
3266 if (t
== LD_TOK_EOF
) {
3267 tcc_error_noabort("unexpected end of file");
3269 } else if (t
== ')') {
3279 #endif /* !TCC_TARGET_PE */