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_reloca(Section
*symtab
, Section
*s
, unsigned long offset
,
273 int type
, int symbol
, unsigned long addend
)
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 #if defined(TCC_TARGET_ARM64) || defined(TCC_TARGET_X86_64)
295 rel
->r_addend
= addend
;
298 tcc_error("non-zero addend on REL architecture");
302 ST_FUNC
void put_elf_reloc(Section
*symtab
, Section
*s
, unsigned long offset
,
303 int type
, int symbol
)
305 put_elf_reloca(symtab
, s
, offset
, type
, symbol
, 0);
308 /* put stab debug information */
310 ST_FUNC
void put_stabs(const char *str
, int type
, int other
, int desc
,
315 sym
= section_ptr_add(stab_section
, sizeof(Stab_Sym
));
317 sym
->n_strx
= put_elf_str(stabstr_section
, str
);
322 sym
->n_other
= other
;
324 sym
->n_value
= value
;
327 ST_FUNC
void put_stabs_r(const char *str
, int type
, int other
, int desc
,
328 unsigned long value
, Section
*sec
, int sym_index
)
330 put_stabs(str
, type
, other
, desc
, value
);
331 put_elf_reloc(symtab_section
, stab_section
,
332 stab_section
->data_offset
- sizeof(unsigned int),
333 R_DATA_32
, sym_index
);
336 ST_FUNC
void put_stabn(int type
, int other
, int desc
, int value
)
338 put_stabs(NULL
, type
, other
, desc
, value
);
341 ST_FUNC
void put_stabd(int type
, int other
, int desc
)
343 put_stabs(NULL
, type
, other
, desc
, 0);
346 /* Browse each elem of type <type> in section <sec> starting at elem <startoff>
347 using variable <elem> */
348 #define for_each_elem(sec, startoff, elem, type) \
349 for (elem = (type *) sec->data + startoff; \
350 elem < (type *) (sec->data + sec->data_offset); elem++)
352 /* In an ELF file symbol table, the local symbols must appear below
353 the global and weak ones. Since TCC cannot sort it while generating
354 the code, we must do it after. All the relocation tables are also
355 modified to take into account the symbol table sorting */
356 static void sort_syms(TCCState
*s1
, Section
*s
)
358 int *old_to_new_syms
;
366 nb_syms
= s
->data_offset
/ sizeof(ElfW(Sym
));
367 new_syms
= tcc_malloc(nb_syms
* sizeof(ElfW(Sym
)));
368 old_to_new_syms
= tcc_malloc(nb_syms
* sizeof(int));
370 /* first pass for local symbols */
371 p
= (ElfW(Sym
) *)s
->data
;
373 for(i
= 0; i
< nb_syms
; i
++) {
374 if (ELFW(ST_BIND
)(p
->st_info
) == STB_LOCAL
) {
375 old_to_new_syms
[i
] = q
- new_syms
;
380 /* save the number of local symbols in section header */
381 s
->sh_info
= q
- new_syms
;
383 /* then second pass for non local symbols */
384 p
= (ElfW(Sym
) *)s
->data
;
385 for(i
= 0; i
< nb_syms
; i
++) {
386 if (ELFW(ST_BIND
)(p
->st_info
) != STB_LOCAL
) {
387 old_to_new_syms
[i
] = q
- new_syms
;
393 /* we copy the new symbols to the old */
394 memcpy(s
->data
, new_syms
, nb_syms
* sizeof(ElfW(Sym
)));
397 /* now we modify all the relocations */
398 for(i
= 1; i
< s1
->nb_sections
; i
++) {
399 sr
= s1
->sections
[i
];
400 if (sr
->sh_type
== SHT_RELX
&& sr
->link
== s
) {
401 for_each_elem(sr
, 0, rel
, ElfW_Rel
) {
402 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
403 type
= ELFW(R_TYPE
)(rel
->r_info
);
404 sym_index
= old_to_new_syms
[sym_index
];
405 rel
->r_info
= ELFW(R_INFO
)(sym_index
, type
);
410 tcc_free(old_to_new_syms
);
413 /* relocate common symbols in the .bss section */
414 ST_FUNC
void relocate_common_syms(void)
417 unsigned long offset
, align
;
419 for_each_elem(symtab_section
, 1, sym
, ElfW(Sym
)) {
420 if (sym
->st_shndx
== SHN_COMMON
) {
422 align
= sym
->st_value
;
423 offset
= bss_section
->data_offset
;
424 offset
= (offset
+ align
- 1) & -align
;
425 sym
->st_value
= offset
;
426 sym
->st_shndx
= bss_section
->sh_num
;
427 offset
+= sym
->st_size
;
428 bss_section
->data_offset
= offset
;
433 /* relocate symbol table, resolve undefined symbols if do_resolve is
434 true and output error if undefined symbol. */
435 ST_FUNC
void relocate_syms(TCCState
*s1
, int do_resolve
)
437 ElfW(Sym
) *sym
, *esym
;
438 int sym_bind
, sh_num
, sym_index
;
441 for_each_elem(symtab_section
, 1, sym
, ElfW(Sym
)) {
442 sh_num
= sym
->st_shndx
;
443 if (sh_num
== SHN_UNDEF
) {
444 name
= (char *) strtab_section
->data
+ sym
->st_name
;
445 /* Use ld.so to resolve symbol for us (for tcc -run) */
447 #if defined TCC_IS_NATIVE && !defined _WIN32
449 name
= (char *) symtab_section
->link
->data
+ sym
->st_name
;
450 addr
= resolve_sym(s1
, name
);
452 sym
->st_value
= (addr_t
)addr
;
454 printf ("relocate_sym: %s -> 0x%lx\n", name
, sym
->st_value
);
459 } else if (s1
->dynsym
) {
460 /* if dynamic symbol exist, then use it */
461 sym_index
= find_elf_sym(s1
->dynsym
, name
);
463 esym
= &((ElfW(Sym
) *)s1
->dynsym
->data
)[sym_index
];
464 sym
->st_value
= esym
->st_value
;
468 /* XXX: _fp_hw seems to be part of the ABI, so we ignore
470 if (!strcmp(name
, "_fp_hw"))
472 /* only weak symbols are accepted to be undefined. Their
474 sym_bind
= ELFW(ST_BIND
)(sym
->st_info
);
475 if (sym_bind
== STB_WEAK
) {
478 tcc_error_noabort("undefined symbol '%s'", name
);
480 } else if (sh_num
< SHN_LORESERVE
) {
481 /* add section base */
482 sym
->st_value
+= s1
->sections
[sym
->st_shndx
]->sh_addr
;
488 /* relocate a given section (CPU dependent) by applying the relocations
489 in the associated relocation section */
490 ST_FUNC
void relocate_section(TCCState
*s1
, Section
*s
)
492 Section
*sr
= s
->reloc
;
498 #if defined TCC_TARGET_I386 || defined TCC_TARGET_X86_64
499 ElfW_Rel
*qrel
= (ElfW_Rel
*) sr
->data
; /* ptr to next reloc entry reused */
503 for_each_elem(sr
, 0, rel
, ElfW_Rel
) {
504 ptr
= s
->data
+ rel
->r_offset
;
506 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
507 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
509 #if defined(TCC_TARGET_ARM64) || defined(TCC_TARGET_X86_64)
510 val
+= rel
->r_addend
;
512 type
= ELFW(R_TYPE
)(rel
->r_info
);
513 addr
= s
->sh_addr
+ rel
->r_offset
;
517 #if defined(TCC_TARGET_I386)
519 if (s1
->output_type
== TCC_OUTPUT_DLL
) {
520 esym_index
= s1
->symtab_to_dynsym
[sym_index
];
521 qrel
->r_offset
= rel
->r_offset
;
523 qrel
->r_info
= ELFW(R_INFO
)(esym_index
, R_386_32
);
527 qrel
->r_info
= ELFW(R_INFO
)(0, R_386_RELATIVE
);
534 if (s1
->output_type
== TCC_OUTPUT_DLL
) {
536 esym_index
= s1
->symtab_to_dynsym
[sym_index
];
538 qrel
->r_offset
= rel
->r_offset
;
539 qrel
->r_info
= ELFW(R_INFO
)(esym_index
, R_386_PC32
);
544 *(int *)ptr
+= val
- addr
;
547 *(int *)ptr
+= val
- addr
;
554 *(int *)ptr
+= s1
->got
->sh_addr
- addr
;
557 *(int *)ptr
+= val
- s1
->got
->sh_addr
;
560 /* we load the got offset */
561 *(int *)ptr
+= s1
->sym_attrs
[sym_index
].got_offset
;
564 if (s1
->output_format
!= TCC_OUTPUT_FORMAT_BINARY
) {
566 tcc_error("can only produce 16-bit binary files");
568 *(short *)ptr
+= val
;
571 if (s1
->output_format
!= TCC_OUTPUT_FORMAT_BINARY
)
573 *(short *)ptr
+= val
- addr
;
575 #elif defined(TCC_TARGET_ARM)
581 int x
, is_thumb
, is_call
, h
, blx_avail
, is_bl
, th_ko
;
582 x
= (*(int *) ptr
) & 0xffffff;
583 if (sym
->st_shndx
== SHN_UNDEF
)
584 val
= s1
->plt
->sh_addr
;
586 printf ("reloc %d: x=0x%x val=0x%x ", type
, x
, val
);
588 (*(int *)ptr
) &= 0xff000000;
592 blx_avail
= (TCC_ARM_VERSION
>= 5);
594 is_bl
= (*(unsigned *) ptr
) >> 24 == 0xeb;
595 is_call
= (type
== R_ARM_CALL
|| (type
== R_ARM_PC24
&& is_bl
));
598 printf (" newx=0x%x name=%s\n", x
,
599 (char *) symtab_section
->link
->data
+ sym
->st_name
);
602 th_ko
= (x
& 3) && (!blx_avail
|| !is_call
);
603 if (th_ko
|| x
>= 0x2000000 || x
< -0x2000000)
604 tcc_error("can't relocate value at %x,%d",addr
, type
);
607 /* Only reached if blx is avail and it is a call */
610 (*(int *)ptr
) = 0xfa << 24; /* bl -> blx */
615 /* Since these relocations only concern Thumb-2 and blx instruction was
616 introduced before Thumb-2, we can assume blx is available and not
619 case R_ARM_THM_JUMP24
:
621 int x
, hi
, lo
, s
, j1
, j2
, i1
, i2
, imm10
, imm11
;
622 int to_thumb
, is_call
, to_plt
, blx_bit
= 1 << 12;
626 if (sym
->st_shndx
== SHN_UNDEF
&&
627 ELFW(ST_BIND
)(sym
->st_info
) == STB_WEAK
)
630 /* Get initial offset */
631 hi
= (*(uint16_t *)ptr
);
632 lo
= (*(uint16_t *)(ptr
+2));
640 x
= (s
<< 24) | (i1
<< 23) | (i2
<< 22) |
641 (imm10
<< 12) | (imm11
<< 1);
645 /* Relocation infos */
648 to_plt
= (val
>= plt
->sh_addr
) &&
649 (val
< plt
->sh_addr
+ plt
->data_offset
);
650 is_call
= (type
== R_ARM_THM_PC22
);
652 /* Compute final offset */
653 if (to_plt
&& !is_call
) /* Point to 1st instr of Thumb stub */
656 if (!to_thumb
&& is_call
) {
657 blx_bit
= 0; /* bl -> blx */
658 x
= (x
+ 3) & -4; /* Compute offset from aligned PC */
661 /* Check that relocation is possible
662 * offset must not be out of range
663 * if target is to be entered in arm mode:
665 - instruction must be a call (bl) or a jump to PLT */
666 if (!to_thumb
|| x
>= 0x1000000 || x
< -0x1000000)
667 if (to_thumb
|| (val
& 2) || (!is_call
&& !to_plt
))
668 tcc_error("can't relocate value at %x,%d",addr
, type
);
670 /* Compute and store final offset */
676 imm10
= (x
>> 12) & 0x3ff;
677 imm11
= (x
>> 1) & 0x7ff;
678 (*(uint16_t *)ptr
) = (uint16_t) ((hi
& 0xf800) |
680 (*(uint16_t *)(ptr
+2)) = (uint16_t) ((lo
& 0xc000) |
681 (j1
<< 13) | blx_bit
| (j2
<< 11) |
686 case R_ARM_MOVW_ABS_NC
:
689 if (type
== R_ARM_MOVT_ABS
)
692 imm4
= (val
>> 12) & 0xf;
693 x
= (imm4
<< 16) | imm12
;
694 if (type
== R_ARM_THM_MOVT_ABS
)
700 case R_ARM_THM_MOVT_ABS
:
701 case R_ARM_THM_MOVW_ABS_NC
:
703 int x
, i
, imm4
, imm3
, imm8
;
704 if (type
== R_ARM_THM_MOVT_ABS
)
707 imm3
= (val
>> 8) & 0x7;
709 imm4
= (val
>> 12) & 0xf;
710 x
= (imm3
<< 28) | (imm8
<< 16) | (i
<< 10) | imm4
;
711 if (type
== R_ARM_THM_MOVT_ABS
)
720 x
= (*(int *)ptr
) & 0x7fffffff;
721 (*(int *)ptr
) &= 0x80000000;
724 if((x
^(x
>>1))&0x40000000)
725 tcc_error("can't relocate value at %x,%d",addr
, type
);
726 (*(int *)ptr
) |= x
& 0x7fffffff;
732 *(int *)ptr
+= val
- addr
;
735 *(int *)ptr
+= s1
->got
->sh_addr
- addr
;
738 *(int *)ptr
+= val
- s1
->got
->sh_addr
;
741 /* we load the got offset */
742 *(int *)ptr
+= s1
->sym_attrs
[sym_index
].got_offset
;
747 /* trade Thumb support for ARMv4 support */
748 if ((0x0ffffff0 & *(int*)ptr
) == 0x012FFF10)
749 *(int*)ptr
^= 0xE12FFF10 ^ 0xE1A0F000; /* BX Rm -> MOV PC, Rm */
752 case R_ARM_JUMP_SLOT
:
753 *(addr_t
*)ptr
= val
;
756 /* Nothing to do. Normally used to indicate a dependency
757 on a certain symbol (like for exception handling under EABI). */
760 fprintf(stderr
,"FIXME: handle reloc type %x at %x [%p] to %x\n",
761 type
, (unsigned)addr
, ptr
, (unsigned)val
);
763 #elif defined(TCC_TARGET_ARM64)
764 case R_AARCH64_ABS64
:
765 *(uint64_t *)ptr
= val
;
767 case R_AARCH64_ABS32
:
768 *(uint32_t *)ptr
= val
;
770 case R_AARCH64_MOVW_UABS_G0_NC
:
771 *(uint32_t *)ptr
= (*(uint32_t *)ptr
& 0xffe0001f) |
774 case R_AARCH64_MOVW_UABS_G1_NC
:
775 *(uint32_t *)ptr
= (*(uint32_t *)ptr
& 0xffe0001f) |
776 (val
>> 16 & 0xffff) << 5;
778 case R_AARCH64_MOVW_UABS_G2_NC
:
779 *(uint32_t *)ptr
= (*(uint32_t *)ptr
& 0xffe0001f) |
780 (val
>> 32 & 0xffff) << 5;
782 case R_AARCH64_MOVW_UABS_G3
:
783 *(uint32_t *)ptr
= (*(uint32_t *)ptr
& 0xffe0001f) |
784 (val
>> 48 & 0xffff) << 5;
786 case R_AARCH64_ADR_PREL_PG_HI21
: {
787 uint64_t off
= (val
>> 12) - (addr
>> 12);
788 if ((off
+ ((uint64_t)1 << 20)) >> 21)
789 tcc_error("R_AARCH64_ADR_PREL_PG_HI21 relocation failed");
790 *(uint32_t *)ptr
= (*(uint32_t *)ptr
& 0x9f00001f) |
791 (off
& 0x1ffffc) << 3 | (off
& 3) << 29;
794 case R_AARCH64_ADD_ABS_LO12_NC
:
795 *(uint32_t *)ptr
= (*(uint32_t *)ptr
& 0xffc003ff) |
798 case R_AARCH64_JUMP26
:
799 case R_AARCH64_CALL26
:
800 /* This check must match the one in build_got_entries, testing
801 if we really need a PLT slot. */
802 if (sym
->st_shndx
== SHN_UNDEF
)
803 /* We've put the PLT slot offset into r_addend when generating
804 it, and that's what we must use as relocation value (adjusted
805 by section offset of course). */
806 val
= s1
->plt
->sh_addr
+ rel
->r_addend
;
808 printf ("reloc %d @ 0x%lx: val=0x%lx name=%s\n", type
, addr
, val
,
809 (char *) symtab_section
->link
->data
+ sym
->st_name
);
811 if (((val
- addr
) + ((uint64_t)1 << 27)) & ~(uint64_t)0xffffffc)
813 tcc_error("R_AARCH64_(JUMP|CALL)26 relocation failed (val=%lx, addr=%lx)", addr
, val
);
815 *(uint32_t *)ptr
= 0x14000000 | (type
== R_AARCH64_CALL26
) << 31 |
816 ((val
- addr
) >> 2 & 0x3ffffff);
818 case R_AARCH64_ADR_GOT_PAGE
: {
820 (((s1
->got
->sh_addr
+
821 s1
->sym_attrs
[sym_index
].got_offset
) >> 12) - (addr
>> 12));
822 if ((off
+ ((uint64_t)1 << 20)) >> 21)
823 tcc_error("R_AARCH64_ADR_GOT_PAGE relocation failed");
824 *(uint32_t *)ptr
= (*(uint32_t *)ptr
& 0x9f00001f) |
825 (off
& 0x1ffffc) << 3 | (off
& 3) << 29;
828 case R_AARCH64_LD64_GOT_LO12_NC
:
829 *(uint32_t *)ptr
= (*(uint32_t *)ptr
& 0xfff803ff) |
830 ((s1
->got
->sh_addr
+ s1
->sym_attrs
[sym_index
].got_offset
)
835 case R_AARCH64_GLOB_DAT
:
836 case R_AARCH64_JUMP_SLOT
:
837 /* They don't need addend */
839 printf ("reloc %d @ 0x%lx: val=0x%lx name=%s\n", type
, addr
,
841 (char *) symtab_section
->link
->data
+ sym
->st_name
);
843 *(addr_t
*)ptr
= val
- rel
->r_addend
;
846 fprintf(stderr
, "FIXME: handle reloc type %x at %x [%p] to %x\n",
847 type
, (unsigned)addr
, ptr
, (unsigned)val
);
849 #elif defined(TCC_TARGET_C67)
857 /* put the low 16 bits of the absolute address
858 add to what is already there */
860 orig
= ((*(int *)(ptr
)) >> 7) & 0xffff;
861 orig
|= (((*(int *)(ptr
+4)) >> 7) & 0xffff) << 16;
863 /* patch both at once - assumes always in pairs Low - High */
865 *(int *) ptr
= (*(int *) ptr
& (~(0xffff << 7)) ) | (((val
+orig
) & 0xffff) << 7);
866 *(int *)(ptr
+4) = (*(int *)(ptr
+4) & (~(0xffff << 7)) ) | ((((val
+orig
)>>16) & 0xffff) << 7);
872 fprintf(stderr
,"FIXME: handle reloc type %x at %x [%p] to %x\n",
873 type
, (unsigned)addr
, ptr
, (unsigned)val
);
875 #elif defined(TCC_TARGET_X86_64)
877 if (s1
->output_type
== TCC_OUTPUT_DLL
) {
878 esym_index
= s1
->symtab_to_dynsym
[sym_index
];
879 qrel
->r_offset
= rel
->r_offset
;
881 qrel
->r_info
= ELFW(R_INFO
)(esym_index
, R_X86_64_64
);
882 qrel
->r_addend
= rel
->r_addend
;
886 qrel
->r_info
= ELFW(R_INFO
)(0, R_X86_64_RELATIVE
);
887 qrel
->r_addend
= *(long long *)ptr
+ val
;
891 *(long long *)ptr
+= val
;
895 if (s1
->output_type
== TCC_OUTPUT_DLL
) {
896 /* XXX: this logic may depend on TCC's codegen
897 now TCC uses R_X86_64_32 even for a 64bit pointer */
898 qrel
->r_info
= ELFW(R_INFO
)(0, R_X86_64_RELATIVE
);
899 qrel
->r_addend
= *(int *)ptr
+ val
;
906 if (s1
->output_type
== TCC_OUTPUT_DLL
) {
908 esym_index
= s1
->symtab_to_dynsym
[sym_index
];
910 qrel
->r_offset
= rel
->r_offset
;
911 qrel
->r_info
= ELFW(R_INFO
)(esym_index
, R_X86_64_PC32
);
912 qrel
->r_addend
= *(int *)ptr
;
920 /* We've put the PLT slot offset into r_addend when generating
921 it, and that's what we must use as relocation value (adjusted
922 by section offset of course). */
923 val
= s1
->plt
->sh_addr
+ rel
->r_addend
;
929 diff
= (long long)val
- addr
;
930 if (diff
<= -2147483647 || diff
> 2147483647) {
931 tcc_error("internal error: relocation failed");
936 case R_X86_64_GLOB_DAT
:
937 case R_X86_64_JUMP_SLOT
:
938 /* They don't need addend */
939 *(addr_t
*)ptr
= val
- rel
->r_addend
;
941 case R_X86_64_GOTPCREL
:
942 *(int *)ptr
+= (s1
->got
->sh_addr
- addr
+
943 s1
->sym_attrs
[sym_index
].got_offset
- 4);
945 case R_X86_64_GOTTPOFF
:
946 *(int *)ptr
+= val
- s1
->got
->sh_addr
;
949 /* we load the got offset */
950 *(int *)ptr
+= s1
->sym_attrs
[sym_index
].got_offset
;
953 #error unsupported processor
957 /* if the relocation is allocated, we change its symbol table */
958 if (sr
->sh_flags
& SHF_ALLOC
)
959 sr
->link
= s1
->dynsym
;
962 /* relocate relocation table in 'sr' */
963 static void relocate_rel(TCCState
*s1
, Section
*sr
)
968 s
= s1
->sections
[sr
->sh_info
];
969 for_each_elem(sr
, 0, rel
, ElfW_Rel
)
970 rel
->r_offset
+= s
->sh_addr
;
973 /* count the number of dynamic relocations so that we can reserve
975 static int prepare_dynamic_rel(TCCState
*s1
, Section
*sr
)
978 int sym_index
, esym_index
, type
, count
;
981 for_each_elem(sr
, 0, rel
, ElfW_Rel
) {
982 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
983 type
= ELFW(R_TYPE
)(rel
->r_info
);
985 #if defined(TCC_TARGET_I386)
987 #elif defined(TCC_TARGET_X86_64)
994 #if defined(TCC_TARGET_I386)
996 #elif defined(TCC_TARGET_X86_64)
999 esym_index
= s1
->symtab_to_dynsym
[sym_index
];
1008 /* allocate the section */
1009 sr
->sh_flags
|= SHF_ALLOC
;
1010 sr
->sh_size
= count
* sizeof(ElfW_Rel
);
1015 static struct sym_attr
*alloc_sym_attr(TCCState
*s1
, int index
)
1018 struct sym_attr
*tab
;
1020 if (index
>= s1
->nb_sym_attrs
) {
1021 /* find immediately bigger power of 2 and reallocate array */
1025 tab
= tcc_realloc(s1
->sym_attrs
, n
* sizeof(*s1
->sym_attrs
));
1026 s1
->sym_attrs
= tab
;
1027 memset(s1
->sym_attrs
+ s1
->nb_sym_attrs
, 0,
1028 (n
- s1
->nb_sym_attrs
) * sizeof(*s1
->sym_attrs
));
1029 s1
->nb_sym_attrs
= n
;
1031 return &s1
->sym_attrs
[index
];
1034 /* XXX: suppress that */
1035 static void put32(unsigned char *p
, uint32_t val
)
1043 #if defined(TCC_TARGET_I386) || defined(TCC_TARGET_ARM) || \
1044 defined(TCC_TARGET_ARM64) || defined(TCC_TARGET_X86_64)
1045 static uint32_t get32(unsigned char *p
)
1047 return p
[0] | (p
[1] << 8) | (p
[2] << 16) | (p
[3] << 24);
1051 static void build_got(TCCState
*s1
)
1055 /* if no got, then create it */
1056 s1
->got
= new_section(s1
, ".got", SHT_PROGBITS
, SHF_ALLOC
| SHF_WRITE
);
1057 s1
->got
->sh_entsize
= 4;
1058 add_elf_sym(symtab_section
, 0, 4, ELFW(ST_INFO
)(STB_GLOBAL
, STT_OBJECT
),
1059 0, s1
->got
->sh_num
, "_GLOBAL_OFFSET_TABLE_");
1060 ptr
= section_ptr_add(s1
->got
, 3 * PTR_SIZE
);
1062 /* keep space for _DYNAMIC pointer, if present */
1064 /* two dummy got entries */
1068 /* keep space for _DYNAMIC pointer, if present */
1071 /* two dummy got entries */
1079 /* put a got or plt entry corresponding to a symbol in symtab_section. 'size'
1080 and 'info' can be modifed if more precise info comes from the DLL.
1081 Returns offset of GOT or PLT slot. */
1082 static unsigned long put_got_entry(TCCState
*s1
,
1083 int reloc_type
, unsigned long size
, int info
,
1086 int index
, need_plt_entry
;
1089 unsigned long offset
;
1091 struct sym_attr
*symattr
;
1097 #ifdef TCC_TARGET_X86_64
1098 (reloc_type
== R_X86_64_JUMP_SLOT
);
1099 #elif defined(TCC_TARGET_I386)
1100 (reloc_type
== R_386_JMP_SLOT
);
1101 #elif defined(TCC_TARGET_ARM)
1102 (reloc_type
== R_ARM_JUMP_SLOT
);
1103 #elif defined(TCC_TARGET_ARM64)
1104 (reloc_type
== R_AARCH64_JUMP_SLOT
);
1109 if (need_plt_entry
&& !s1
->plt
) {
1111 s1
->plt
= new_section(s1
, ".plt", SHT_PROGBITS
,
1112 SHF_ALLOC
| SHF_EXECINSTR
);
1113 s1
->plt
->sh_entsize
= 4;
1116 /* If a got/plt entry already exists for that symbol, no need to add one */
1117 if (sym_index
< s1
->nb_sym_attrs
) {
1118 if (need_plt_entry
&& s1
->sym_attrs
[sym_index
].plt_offset
)
1119 return s1
->sym_attrs
[sym_index
].plt_offset
;
1120 else if (!need_plt_entry
&& s1
->sym_attrs
[sym_index
].got_offset
)
1121 return s1
->sym_attrs
[sym_index
].got_offset
;
1124 symattr
= alloc_sym_attr(s1
, sym_index
);
1126 /* Only store the GOT offset if it's not generated for the PLT entry. */
1127 if (!need_plt_entry
)
1128 symattr
->got_offset
= s1
->got
->data_offset
;
1130 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
1131 name
= (char *) symtab_section
->link
->data
+ sym
->st_name
;
1132 offset
= sym
->st_value
;
1133 #if defined(TCC_TARGET_I386) || defined(TCC_TARGET_X86_64)
1134 if (need_plt_entry
) {
1138 unsigned long relofs
;
1140 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
1143 /* if we build a DLL, we add a %ebx offset */
1144 if (s1
->output_type
== TCC_OUTPUT_DLL
)
1150 /* add a PLT entry */
1152 if (plt
->data_offset
== 0) {
1153 /* first plt entry */
1154 p
= section_ptr_add(plt
, 16);
1155 p
[0] = 0xff; /* pushl got + PTR_SIZE */
1156 p
[1] = modrm
+ 0x10;
1157 put32(p
+ 2, PTR_SIZE
);
1158 p
[6] = 0xff; /* jmp *(got + PTR_SIZE * 2) */
1160 put32(p
+ 8, PTR_SIZE
* 2);
1163 /* The PLT slot refers to the relocation entry it needs
1164 via offset. The reloc entry is created below, so its
1165 offset is the current data_offset. */
1166 relofs
= s1
->got
->reloc
? s1
->got
->reloc
->data_offset
: 0;
1167 symattr
->plt_offset
= plt
->data_offset
;
1168 p
= section_ptr_add(plt
, 16);
1169 p
[0] = 0xff; /* jmp *(got + x) */
1171 put32(p
+ 2, s1
->got
->data_offset
);
1172 p
[6] = 0x68; /* push $xxx */
1173 #ifdef TCC_TARGET_X86_64
1174 /* On x86-64, the relocation is referred to by _index_. */
1175 put32(p
+ 7, relofs
/ sizeof (ElfW_Rel
));
1177 put32(p
+ 7, relofs
);
1179 p
[11] = 0xe9; /* jmp plt_start */
1180 put32(p
+ 12, -(plt
->data_offset
));
1182 /* If this was an UNDEF symbol set the offset in the
1183 dynsymtab to the PLT slot, so that PC32 relocs to it
1185 if (sym
->st_shndx
== SHN_UNDEF
)
1186 offset
= plt
->data_offset
- 16;
1188 #elif defined(TCC_TARGET_ARM)
1189 if (need_plt_entry
) {
1193 /* if we build a DLL, we add a %ebx offset */
1194 if (s1
->output_type
== TCC_OUTPUT_DLL
)
1195 tcc_error("DLLs unimplemented!");
1197 /* add a PLT entry */
1199 if (plt
->data_offset
== 0) {
1200 /* first plt entry */
1201 p
= section_ptr_add(plt
, 16);
1202 put32(p
, 0xe52de004); /* push {lr} */
1203 put32(p
+4, 0xe59fe010); /* ldr lr, [pc, #16] */
1204 put32(p
+8, 0xe08fe00e); /* add lr, pc, lr */
1205 put32(p
+12, 0xe5bef008); /* ldr pc, [lr, #8]! */
1208 symattr
->plt_offset
= plt
->data_offset
;
1209 if (symattr
->plt_thumb_stub
) {
1210 p
= section_ptr_add(plt
, 20);
1211 put32(p
, 0x4778); /* bx pc */
1212 put32(p
+2, 0x46c0); /* nop */
1215 p
= section_ptr_add(plt
, 16);
1216 put32(p
, 0xe59fc004); /* ldr ip, [pc, #4] ; GOT entry offset */
1217 put32(p
+4, 0xe08fc00c); /* add ip, pc, ip ; addr of GOT entry */
1218 put32(p
+8, 0xe59cf000); /* ldr pc, [ip] ; jump to GOT entry */
1219 put32(p
+12, s1
->got
->data_offset
); /* GOT entry off once patched */
1221 /* the symbol is modified so that it will be relocated to
1223 if (sym
->st_shndx
== SHN_UNDEF
)
1224 offset
= plt
->data_offset
- 16;
1226 #elif defined(TCC_TARGET_ARM64)
1227 if (need_plt_entry
) {
1231 if (s1
->output_type
== TCC_OUTPUT_DLL
)
1232 tcc_error("DLLs unimplemented!");
1235 if (plt
->data_offset
== 0)
1236 section_ptr_add(plt
, 32);
1237 symattr
->plt_offset
= plt
->data_offset
;
1238 p
= section_ptr_add(plt
, 16);
1239 put32(p
, s1
->got
->data_offset
);
1240 put32(p
+ 4, (uint64_t)s1
->got
->data_offset
>> 32);
1242 if (sym
->st_shndx
== SHN_UNDEF
)
1243 offset
= plt
->data_offset
- 16;
1245 #elif defined(TCC_TARGET_C67)
1247 tcc_error("C67 got not implemented");
1250 #error unsupported CPU
1253 /* XXX This might generate multiple syms for name. */
1254 index
= put_elf_sym(s1
->dynsym
, offset
,
1255 size
, info
, 0, sym
->st_shndx
, name
);
1256 /* Create the relocation (it's against the GOT for PLT
1258 put_elf_reloc(s1
->dynsym
, s1
->got
,
1259 s1
->got
->data_offset
,
1262 /* Without .dynsym (i.e. static link or memory output) we
1263 still need relocs against the generated got, so as to fill
1264 the entries with the symbol values (determined later). */
1265 put_elf_reloc(symtab_section
, s1
->got
,
1266 s1
->got
->data_offset
,
1267 reloc_type
, sym_index
);
1269 /* And now create the GOT slot itself. */
1270 ptr
= section_ptr_add(s1
->got
, PTR_SIZE
);
1273 return symattr
->plt_offset
;
1275 return symattr
->got_offset
;
1278 /* build GOT and PLT entries */
1279 ST_FUNC
void build_got_entries(TCCState
*s1
)
1284 int i
, type
, reloc_type
, sym_index
;
1286 for(i
= 1; i
< s1
->nb_sections
; i
++) {
1287 s
= s1
->sections
[i
];
1288 if (s
->sh_type
!= SHT_RELX
)
1290 /* no need to handle got relocations */
1291 if (s
->link
!= symtab_section
)
1293 for_each_elem(s
, 0, rel
, ElfW_Rel
) {
1294 type
= ELFW(R_TYPE
)(rel
->r_info
);
1296 #if defined(TCC_TARGET_I386)
1303 if (type
== R_386_GOT32
|| type
== R_386_PLT32
) {
1304 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
1305 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
1306 /* look at the symbol got offset. If none, then add one */
1307 if (type
== R_386_GOT32
)
1308 reloc_type
= R_386_GLOB_DAT
;
1310 reloc_type
= R_386_JMP_SLOT
;
1311 put_got_entry(s1
, reloc_type
, sym
->st_size
, sym
->st_info
,
1315 #elif defined(TCC_TARGET_ARM)
1325 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
1326 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
1327 if (type
!= R_ARM_GOTOFF
&& type
!= R_ARM_GOTPC
1328 && sym
->st_shndx
== SHN_UNDEF
) {
1330 /* look at the symbol got offset. If none, then add one */
1331 if (type
== R_ARM_GOT32
)
1332 reloc_type
= R_ARM_GLOB_DAT
;
1334 reloc_type
= R_ARM_JUMP_SLOT
;
1335 ofs
= put_got_entry(s1
, reloc_type
, sym
->st_size
,
1336 sym
->st_info
, sym_index
);
1338 printf ("maybegot: %s, %d, %d --> ofs=0x%x\n",
1339 (char *) symtab_section
->link
->data
+ sym
->st_name
,
1340 type
, sym
->st_shndx
, ofs
);
1342 if (type
!= R_ARM_GOT32
) {
1343 addr_t
*ptr
= (addr_t
*)(s1
->sections
[s
->sh_info
]->data
1345 /* x must be signed! */
1346 int x
= *ptr
& 0xffffff;
1352 printf ("insn=0x%x --> 0x%x (x==0x%x)\n", *ptr
,
1353 (*ptr
& 0xff000000) | x
, x
);
1355 *ptr
= (*ptr
& 0xff000000) | x
;
1359 case R_ARM_THM_JUMP24
:
1360 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
1361 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
1362 /* We are relocating a jump from thumb code to arm code */
1363 if (sym
->st_shndx
!= SHN_UNDEF
&& !(sym
->st_value
& 1)) {
1366 char *name
, buf
[1024];
1367 Section
*text_section
;
1369 name
= (char *) symtab_section
->link
->data
+ sym
->st_name
;
1370 text_section
= s1
->sections
[sym
->st_shndx
];
1371 /* Modify reloc to target a thumb stub to switch to ARM */
1372 snprintf(buf
, sizeof(buf
), "%s_from_thumb", name
);
1373 index
= put_elf_sym(symtab_section
,
1374 text_section
->data_offset
+ 1,
1375 sym
->st_size
, sym
->st_info
, 0,
1376 sym
->st_shndx
, buf
);
1377 rel
->r_info
= ELFW(R_INFO
)(index
, type
);
1378 /* Create a thumb stub fonction to switch to ARM mode */
1379 put_elf_reloc(symtab_section
, text_section
,
1380 text_section
->data_offset
+ 4, R_ARM_JUMP24
,
1382 p
= section_ptr_add(text_section
, 8);
1383 put32(p
, 0x4778); /* bx pc */
1384 put32(p
+2, 0x46c0); /* nop */
1385 put32(p
+4, 0xeafffffe); /* b $sym */
1387 #elif defined(TCC_TARGET_ARM64)
1388 //xx Other cases may be required here:
1389 case R_AARCH64_ADR_GOT_PAGE
:
1390 case R_AARCH64_LD64_GOT_LO12_NC
:
1393 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
1394 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
1395 reloc_type
= R_AARCH64_GLOB_DAT
;
1396 put_got_entry(s1
, reloc_type
, sym
->st_size
, sym
->st_info
,
1400 case R_AARCH64_JUMP26
:
1401 case R_AARCH64_CALL26
:
1404 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
1405 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
1406 if (sym
->st_shndx
== SHN_UNDEF
) {
1408 reloc_type
= R_AARCH64_JUMP_SLOT
;
1409 ofs
= put_got_entry(s1
, reloc_type
, sym
->st_size
,
1410 sym
->st_info
, sym_index
);
1411 /* We store the place of the generated PLT slot
1413 rel
->r_addend
+= ofs
;
1416 #elif defined(TCC_TARGET_C67)
1423 if (type
== R_C60_GOT32
|| type
== R_C60_PLT32
) {
1424 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
1425 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
1426 /* look at the symbol got offset. If none, then add one */
1427 if (type
== R_C60_GOT32
)
1428 reloc_type
= R_C60_GLOB_DAT
;
1430 reloc_type
= R_C60_JMP_SLOT
;
1431 put_got_entry(s1
, reloc_type
, sym
->st_size
, sym
->st_info
,
1435 #elif defined(TCC_TARGET_X86_64)
1436 case R_X86_64_GOT32
:
1437 case R_X86_64_GOTTPOFF
:
1438 case R_X86_64_GOTPCREL
:
1439 case R_X86_64_PLT32
:
1440 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
1441 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
1442 if (type
== R_X86_64_PLT32
&&
1443 ELFW(ST_VISIBILITY
)(sym
->st_other
) != STV_DEFAULT
)
1445 rel
->r_info
= ELFW(R_INFO
)(sym_index
, R_X86_64_PC32
);
1451 if (type
== R_X86_64_GOT32
|| type
== R_X86_64_GOTPCREL
||
1452 type
== R_X86_64_PLT32
) {
1454 /* look at the symbol got offset. If none, then add one */
1455 if (type
== R_X86_64_GOT32
|| type
== R_X86_64_GOTPCREL
)
1456 reloc_type
= R_X86_64_GLOB_DAT
;
1458 reloc_type
= R_X86_64_JUMP_SLOT
;
1459 ofs
= put_got_entry(s1
, reloc_type
, sym
->st_size
,
1460 sym
->st_info
, sym_index
);
1461 if (type
== R_X86_64_PLT32
)
1462 /* We store the place of the generated PLT slot
1464 rel
->r_addend
+= ofs
;
1468 #error unsupported CPU
1477 ST_FUNC Section
*new_symtab(TCCState
*s1
,
1478 const char *symtab_name
, int sh_type
, int sh_flags
,
1479 const char *strtab_name
,
1480 const char *hash_name
, int hash_sh_flags
)
1482 Section
*symtab
, *strtab
, *hash
;
1483 int *ptr
, nb_buckets
;
1485 symtab
= new_section(s1
, symtab_name
, sh_type
, sh_flags
);
1486 symtab
->sh_entsize
= sizeof(ElfW(Sym
));
1487 strtab
= new_section(s1
, strtab_name
, SHT_STRTAB
, sh_flags
);
1488 put_elf_str(strtab
, "");
1489 symtab
->link
= strtab
;
1490 put_elf_sym(symtab
, 0, 0, 0, 0, 0, NULL
);
1494 hash
= new_section(s1
, hash_name
, SHT_HASH
, hash_sh_flags
);
1495 hash
->sh_entsize
= sizeof(int);
1496 symtab
->hash
= hash
;
1497 hash
->link
= symtab
;
1499 ptr
= section_ptr_add(hash
, (2 + nb_buckets
+ 1) * sizeof(int));
1500 ptr
[0] = nb_buckets
;
1502 memset(ptr
+ 2, 0, (nb_buckets
+ 1) * sizeof(int));
1506 /* put dynamic tag */
1507 static void put_dt(Section
*dynamic
, int dt
, addr_t val
)
1510 dyn
= section_ptr_add(dynamic
, sizeof(ElfW(Dyn
)));
1512 dyn
->d_un
.d_val
= val
;
1515 static void add_init_array_defines(TCCState
*s1
, const char *section_name
)
1519 char sym_start
[1024];
1522 snprintf(sym_start
, sizeof(sym_start
), "__%s_start", section_name
+ 1);
1523 snprintf(sym_end
, sizeof(sym_end
), "__%s_end", section_name
+ 1);
1525 s
= find_section(s1
, section_name
);
1530 end_offset
= s
->data_offset
;
1533 add_elf_sym(symtab_section
,
1535 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1536 s
->sh_num
, sym_start
);
1537 add_elf_sym(symtab_section
,
1539 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1540 s
->sh_num
, sym_end
);
1543 ST_FUNC
void tcc_add_bcheck(TCCState
*s1
)
1545 #ifdef CONFIG_TCC_BCHECK
1547 Section
*init_section
;
1548 unsigned char *pinit
;
1551 if (0 == s1
->do_bounds_check
)
1554 /* XXX: add an object file to do that */
1555 ptr
= section_ptr_add(bounds_section
, sizeof(unsigned long));
1557 add_elf_sym(symtab_section
, 0, 0,
1558 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1559 bounds_section
->sh_num
, "__bounds_start");
1560 #ifdef TCC_TARGET_I386
1561 if (s1
->output_type
!= TCC_OUTPUT_MEMORY
) {
1562 /* add 'call __bound_init()' in .init section */
1563 init_section
= find_section(s1
, ".init");
1564 pinit
= section_ptr_add(init_section
, 5);
1566 put32(pinit
+ 1, -4);
1567 sym_index
= find_elf_sym(symtab_section
, "__bound_init");
1568 put_elf_reloc(symtab_section
, init_section
,
1569 init_section
->data_offset
- 4, R_386_PC32
, sym_index
);
1575 static inline int tcc_add_support(TCCState
*s1
, const char *filename
)
1578 snprintf(buf
, sizeof(buf
), "%s/%s/%s", s1
->tcc_lib_path
,
1579 /* an cpu specific path inside tcc_lib_path, mainly for keeping libtcc1.a */
1580 #ifdef TCC_TARGET_I386
1583 #ifdef TCC_TARGET_X86_64
1586 #ifdef TCC_TARGET_ARM
1589 #ifdef TCC_TARGET_ARM64
1592 #ifdef TCC_TARGET_C67
1597 return tcc_add_file(s1
, buf
);
1600 /* add tcc runtime libraries */
1601 ST_FUNC
void tcc_add_runtime(TCCState
*s1
)
1604 if (!s1
->nostdlib
) {
1605 tcc_add_library(s1
, "c");
1606 #ifdef CONFIG_USE_LIBGCC
1607 if (!s1
->static_link
) {
1608 tcc_add_file(s1
, TCC_LIBGCC
);
1611 tcc_add_support(s1
, "libtcc1.a");
1614 /* tcc_add_bcheck tries to relocate a call to __bound_init in _init so
1615 libtcc1.a must be loaded before for __bound_init to be defined and
1616 crtn.o must be loaded after to not finalize _init too early. */
1619 if (!s1
->nostdlib
) {
1620 /* add crt end if not memory output */
1621 if (s1
->output_type
!= TCC_OUTPUT_MEMORY
)
1622 tcc_add_crt(s1
, "crtn.o");
1626 /* add various standard linker symbols (must be done after the
1627 sections are filled (for example after allocating common
1629 ST_FUNC
void tcc_add_linker_symbols(TCCState
*s1
)
1635 add_elf_sym(symtab_section
,
1636 text_section
->data_offset
, 0,
1637 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1638 text_section
->sh_num
, "_etext");
1639 add_elf_sym(symtab_section
,
1640 data_section
->data_offset
, 0,
1641 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1642 data_section
->sh_num
, "_edata");
1643 add_elf_sym(symtab_section
,
1644 bss_section
->data_offset
, 0,
1645 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1646 bss_section
->sh_num
, "_end");
1647 /* horrible new standard ldscript defines */
1648 add_init_array_defines(s1
, ".preinit_array");
1649 add_init_array_defines(s1
, ".init_array");
1650 add_init_array_defines(s1
, ".fini_array");
1652 /* add start and stop symbols for sections whose name can be
1654 for(i
= 1; i
< s1
->nb_sections
; i
++) {
1655 s
= s1
->sections
[i
];
1656 if (s
->sh_type
== SHT_PROGBITS
&&
1657 (s
->sh_flags
& SHF_ALLOC
)) {
1661 /* check if section name can be expressed in C */
1667 if (!isid(ch
) && !isnum(ch
))
1671 snprintf(buf
, sizeof(buf
), "__start_%s", s
->name
);
1672 add_elf_sym(symtab_section
,
1674 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1676 snprintf(buf
, sizeof(buf
), "__stop_%s", s
->name
);
1677 add_elf_sym(symtab_section
,
1679 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1686 static void tcc_output_binary(TCCState
*s1
, FILE *f
,
1687 const int *sec_order
)
1690 int i
, offset
, size
;
1693 for(i
=1;i
<s1
->nb_sections
;i
++) {
1694 s
= s1
->sections
[sec_order
[i
]];
1695 if (s
->sh_type
!= SHT_NOBITS
&&
1696 (s
->sh_flags
& SHF_ALLOC
)) {
1697 while (offset
< s
->sh_offset
) {
1702 fwrite(s
->data
, 1, size
, f
);
1708 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1710 #define EXTRA_RELITEMS 14
1712 /* move the relocation value from .dynsym to .got */
1713 void patch_dynsym_undef(TCCState
*s1
, Section
*s
)
1715 uint32_t *gotd
= (void *)s1
->got
->data
;
1718 gotd
+= 3; /* dummy entries in .got */
1719 /* relocate symbols in .dynsym */
1720 for_each_elem(s
, 1, sym
, ElfW(Sym
)) {
1721 if (sym
->st_shndx
== SHN_UNDEF
) {
1722 *gotd
++ = sym
->st_value
+ 6; /* XXX 6 is magic ? */
1729 #define EXTRA_RELITEMS 9
1731 /* zero plt offsets of weak symbols in .dynsym */
1732 void patch_dynsym_undef(TCCState
*s1
, Section
*s
)
1736 for_each_elem(s
, 1, sym
, ElfW(Sym
))
1737 if (sym
->st_shndx
== SHN_UNDEF
&& ELFW(ST_BIND
)(sym
->st_info
) == STB_WEAK
)
1742 ST_FUNC
void fill_got_entry(TCCState
*s1
, ElfW_Rel
*rel
)
1744 int sym_index
= ELFW(R_SYM
) (rel
->r_info
);
1745 ElfW(Sym
) *sym
= &((ElfW(Sym
) *) symtab_section
->data
)[sym_index
];
1746 unsigned long offset
;
1748 if (sym_index
>= s1
->nb_sym_attrs
)
1750 offset
= s1
->sym_attrs
[sym_index
].got_offset
;
1751 section_reserve(s1
->got
, offset
+ PTR_SIZE
);
1752 #ifdef TCC_TARGET_X86_64
1753 /* only works for x86-64 */
1754 put32(s1
->got
->data
+ offset
+ 4, sym
->st_value
>> 32);
1756 put32(s1
->got
->data
+ offset
, sym
->st_value
& 0xffffffff);
1759 /* Perform relocation to GOT or PLT entries */
1760 ST_FUNC
void fill_got(TCCState
*s1
)
1766 for(i
= 1; i
< s1
->nb_sections
; i
++) {
1767 s
= s1
->sections
[i
];
1768 if (s
->sh_type
!= SHT_RELX
)
1770 /* no need to handle got relocations */
1771 if (s
->link
!= symtab_section
)
1773 for_each_elem(s
, 0, rel
, ElfW_Rel
) {
1774 switch (ELFW(R_TYPE
) (rel
->r_info
)) {
1775 case R_X86_64_GOT32
:
1776 case R_X86_64_GOTPCREL
:
1777 case R_X86_64_PLT32
:
1778 fill_got_entry(s1
, rel
);
1785 /* Bind symbols of executable: resolve undefined symbols from exported symbols
1786 in shared libraries and export non local defined symbols to shared libraries
1787 if -rdynamic switch was given on command line */
1788 static void bind_exe_dynsyms(TCCState
*s1
)
1791 int sym_index
, index
;
1792 ElfW(Sym
) *sym
, *esym
;
1795 /* Resolve undefined symbols from dynamic symbols. When there is a match:
1796 - if STT_FUNC or STT_GNU_IFUNC symbol -> add it in PLT
1797 - if STT_OBJECT symbol -> add it in .bss section with suitable reloc */
1798 for_each_elem(symtab_section
, 1, sym
, ElfW(Sym
)) {
1799 if (sym
->st_shndx
== SHN_UNDEF
) {
1800 name
= (char *) symtab_section
->link
->data
+ sym
->st_name
;
1801 sym_index
= find_elf_sym(s1
->dynsymtab_section
, name
);
1803 esym
= &((ElfW(Sym
) *)s1
->dynsymtab_section
->data
)[sym_index
];
1804 type
= ELFW(ST_TYPE
)(esym
->st_info
);
1805 if ((type
== STT_FUNC
) || (type
== STT_GNU_IFUNC
)) {
1806 /* Indirect functions shall have STT_FUNC type in executable
1807 * dynsym section. Indeed, a dlsym call following a lazy
1808 * resolution would pick the symbol value from the
1809 * executable dynsym entry which would contain the address
1810 * of the function wanted by the caller of dlsym instead of
1811 * the address of the function that would return that
1813 put_got_entry(s1
, R_JMP_SLOT
, esym
->st_size
,
1814 ELFW(ST_INFO
)(STB_GLOBAL
,STT_FUNC
),
1815 sym
- (ElfW(Sym
) *)symtab_section
->data
);
1816 } else if (type
== STT_OBJECT
) {
1817 unsigned long offset
;
1819 offset
= bss_section
->data_offset
;
1820 /* XXX: which alignment ? */
1821 offset
= (offset
+ 16 - 1) & -16;
1822 index
= put_elf_sym(s1
->dynsym
, offset
, esym
->st_size
,
1823 esym
->st_info
, 0, bss_section
->sh_num
,
1825 /* Ensure R_COPY works for weak symbol aliases */
1826 if (ELFW(ST_BIND
)(esym
->st_info
) == STB_WEAK
) {
1827 for_each_elem(s1
->dynsymtab_section
, 1, dynsym
, ElfW(Sym
)) {
1828 if ((dynsym
->st_value
== esym
->st_value
)
1829 && (ELFW(ST_BIND
)(dynsym
->st_info
) == STB_GLOBAL
)) {
1830 char *dynname
= (char *) s1
->dynsymtab_section
->link
->data
1832 put_elf_sym(s1
->dynsym
, offset
, dynsym
->st_size
,
1834 bss_section
->sh_num
, dynname
);
1839 put_elf_reloc(s1
->dynsym
, bss_section
,
1840 offset
, R_COPY
, index
);
1841 offset
+= esym
->st_size
;
1842 bss_section
->data_offset
= offset
;
1845 /* STB_WEAK undefined symbols are accepted */
1846 /* XXX: _fp_hw seems to be part of the ABI, so we ignore it */
1847 if (ELFW(ST_BIND
)(sym
->st_info
) == STB_WEAK
||
1848 !strcmp(name
, "_fp_hw")) {
1850 tcc_error_noabort("undefined symbol '%s'", name
);
1853 } else if (s1
->rdynamic
&& ELFW(ST_BIND
)(sym
->st_info
) != STB_LOCAL
) {
1854 /* if -rdynamic option, then export all non local symbols */
1855 name
= (char *) symtab_section
->link
->data
+ sym
->st_name
;
1856 put_elf_sym(s1
->dynsym
, sym
->st_value
, sym
->st_size
, sym
->st_info
,
1857 0, sym
->st_shndx
, name
);
1862 /* Bind symbols of libraries: export non local symbols of executable that
1863 resolve undefined symbols of shared libraries */
1864 static void bind_libs_dynsyms(TCCState
*s1
)
1868 ElfW(Sym
) *sym
, *esym
;
1870 /* now look at unresolved dynamic symbols and export
1871 corresponding symbol */
1872 for_each_elem(s1
->dynsymtab_section
, 1, esym
, ElfW(Sym
)) {
1873 if (esym
->st_shndx
== SHN_UNDEF
) {
1874 name
= (char *) s1
->dynsymtab_section
->link
->data
+ esym
->st_name
;
1875 sym_index
= find_elf_sym(symtab_section
, name
);
1877 /* XXX: avoid adding a symbol if already present because of
1879 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
1880 put_elf_sym(s1
->dynsym
, sym
->st_value
, sym
->st_size
,
1881 sym
->st_info
, 0, sym
->st_shndx
, name
);
1883 /* weak symbols can stay undefined */
1884 if (ELFW(ST_BIND
)(esym
->st_info
) != STB_WEAK
)
1885 tcc_warning("undefined dynamic symbol '%s'", name
);
1891 /* Export all non local symbols (for shared libraries) */
1892 static void export_global_syms(TCCState
*s1
)
1894 int nb_syms
, dynindex
, index
;
1898 nb_syms
= symtab_section
->data_offset
/ sizeof(ElfW(Sym
));
1899 s1
->symtab_to_dynsym
= tcc_mallocz(sizeof(int) * nb_syms
);
1900 for_each_elem(symtab_section
, 1, sym
, ElfW(Sym
)) {
1901 if (ELFW(ST_BIND
)(sym
->st_info
) != STB_LOCAL
) {
1902 name
= (char *) symtab_section
->link
->data
+ sym
->st_name
;
1903 dynindex
= put_elf_sym(s1
->dynsym
, sym
->st_value
, sym
->st_size
,
1904 sym
->st_info
, 0, sym
->st_shndx
, name
);
1905 index
= sym
- (ElfW(Sym
) *) symtab_section
->data
;
1906 s1
->symtab_to_dynsym
[index
] = dynindex
;
1911 /* relocate the PLT: compute addresses and offsets in the PLT now that final
1912 address for PLT and GOT are known (see fill_program_header) */
1913 ST_FUNC
void relocate_plt(TCCState
*s1
)
1921 p_end
= p
+ s1
->plt
->data_offset
;
1923 #if defined(TCC_TARGET_I386)
1924 put32(p
+ 2, get32(p
+ 2) + s1
->got
->sh_addr
);
1925 put32(p
+ 8, get32(p
+ 8) + s1
->got
->sh_addr
);
1928 put32(p
+ 2, get32(p
+ 2) + s1
->got
->sh_addr
);
1931 #elif defined(TCC_TARGET_X86_64)
1932 int x
= s1
->got
->sh_addr
- s1
->plt
->sh_addr
- 6;
1933 put32(p
+ 2, get32(p
+ 2) + x
);
1934 put32(p
+ 8, get32(p
+ 8) + x
- 6);
1937 put32(p
+ 2, get32(p
+ 2) + x
+ s1
->plt
->data
- p
);
1940 #elif defined(TCC_TARGET_ARM)
1942 x
=s1
->got
->sh_addr
- s1
->plt
->sh_addr
- 12;
1945 if (get32(p
) == 0x46c04778) /* PLT Thumb stub present */
1947 put32(p
+ 12, x
+ get32(p
+ 12) + s1
->plt
->data
- p
);
1950 #elif defined(TCC_TARGET_ARM64)
1951 uint64_t plt
= s1
->plt
->sh_addr
;
1952 uint64_t got
= s1
->got
->sh_addr
;
1953 uint64_t off
= (got
>> 12) - (plt
>> 12);
1954 if ((off
+ ((uint32_t)1 << 20)) >> 21)
1955 tcc_error("Failed relocating PLT (off=0x%lx, got=0x%lx, plt=0x%lx)", off
, got
, plt
);
1956 put32(p
, 0xa9bf7bf0); // stp x16,x30,[sp,#-16]!
1957 put32(p
+ 4, (0x90000010 | // adrp x16,...
1958 (off
& 0x1ffffc) << 3 | (off
& 3) << 29));
1959 put32(p
+ 8, (0xf9400211 | // ldr x17,[x16,#...]
1960 (got
& 0xff8) << 7));
1961 put32(p
+ 12, (0x91000210 | // add x16,x16,#...
1962 (got
& 0xfff) << 10));
1963 put32(p
+ 16, 0xd61f0220); // br x17
1964 put32(p
+ 20, 0xd503201f); // nop
1965 put32(p
+ 24, 0xd503201f); // nop
1966 put32(p
+ 28, 0xd503201f); // nop
1969 uint64_t pc
= plt
+ (p
- s1
->plt
->data
);
1970 uint64_t addr
= got
+
1971 (get32(p
) | (uint64_t)get32(p
+ 4) << 32);
1972 uint32_t off
= (addr
>> 12) - (pc
>> 12);
1973 if ((off
+ ((uint32_t)1 << 20)) >> 21)
1974 tcc_error("Failed relocating PLT (off=0x%lx, addr=0x%lx, pc=0x%lx)", off
, addr
, pc
);
1975 put32(p
, (0x90000010 | // adrp x16,...
1976 (off
& 0x1ffffc) << 3 | (off
& 3) << 29));
1977 put32(p
+ 4, (0xf9400211 | // ldr x17,[x16,#...]
1978 (addr
& 0xff8) << 7));
1979 put32(p
+ 8, (0x91000210 | // add x16,x16,#...
1980 (addr
& 0xfff) << 10));
1981 put32(p
+ 12, 0xd61f0220); // br x17
1984 #elif defined(TCC_TARGET_C67)
1987 #error unsupported CPU
1992 /* Allocate strings for section names and decide if an unallocated section
1995 NOTE: the strsec section comes last, so its size is also correct ! */
1996 static void alloc_sec_names(TCCState
*s1
, int file_type
, Section
*strsec
)
2001 /* Allocate strings for section names */
2002 for(i
= 1; i
< s1
->nb_sections
; i
++) {
2003 s
= s1
->sections
[i
];
2004 s
->sh_name
= put_elf_str(strsec
, s
->name
);
2005 /* when generating a DLL, we include relocations but we may
2007 if (file_type
== TCC_OUTPUT_DLL
&&
2008 s
->sh_type
== SHT_RELX
&&
2009 !(s
->sh_flags
& SHF_ALLOC
)) {
2010 /* gr: avoid bogus relocs for empty (debug) sections */
2011 if (s1
->sections
[s
->sh_info
]->sh_flags
& SHF_ALLOC
)
2012 prepare_dynamic_rel(s1
, s
);
2013 else if (s1
->do_debug
)
2014 s
->sh_size
= s
->data_offset
;
2015 } else if (s1
->do_debug
||
2016 file_type
== TCC_OUTPUT_OBJ
||
2017 (s
->sh_flags
& SHF_ALLOC
) ||
2018 i
== (s1
->nb_sections
- 1)) {
2019 /* we output all sections if debug or object file */
2020 s
->sh_size
= s
->data_offset
;
2025 /* Info to be copied in dynamic section */
2029 unsigned long dyn_rel_off
;
2032 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2038 /* Assign sections to segments and decide how are sections laid out when loaded
2039 in memory. This function also fills corresponding program headers. */
2040 static int layout_sections(TCCState
*s1
, ElfW(Phdr
) *phdr
, int phnum
,
2041 Section
*interp
, Section
* strsec
,
2042 struct dyn_inf
*dyninf
, int *sec_order
)
2044 int i
, j
, k
, file_type
, sh_order_index
, file_offset
;
2045 unsigned long s_align
;
2051 file_type
= s1
->output_type
;
2054 if (s1
->output_format
== TCC_OUTPUT_FORMAT_ELF
)
2055 file_offset
= sizeof(ElfW(Ehdr
)) + phnum
* sizeof(ElfW(Phdr
));
2056 s_align
= ELF_PAGE_SIZE
;
2057 if (s1
->section_align
)
2058 s_align
= s1
->section_align
;
2061 if (s1
->has_text_addr
) {
2062 int a_offset
, p_offset
;
2063 addr
= s1
->text_addr
;
2064 /* we ensure that (addr % ELF_PAGE_SIZE) == file_offset %
2066 a_offset
= (int) (addr
& (s_align
- 1));
2067 p_offset
= file_offset
& (s_align
- 1);
2068 if (a_offset
< p_offset
)
2069 a_offset
+= s_align
;
2070 file_offset
+= (a_offset
- p_offset
);
2072 if (file_type
== TCC_OUTPUT_DLL
)
2075 addr
= ELF_START_ADDR
;
2076 /* compute address after headers */
2077 addr
+= (file_offset
& (s_align
- 1));
2081 /* Leave one program headers for the program interpreter and one for
2082 the program header table itself if needed. These are done later as
2083 they require section layout to be done first. */
2085 ph
+= 1 + HAVE_PHDR
;
2087 /* dynamic relocation table information, for .dynamic section */
2088 dyninf
->rel_addr
= dyninf
->rel_size
= 0;
2089 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2090 dyninf
->bss_addr
= dyninf
->bss_size
= 0;
2093 for(j
= 0; j
< 2; j
++) {
2094 ph
->p_type
= PT_LOAD
;
2096 ph
->p_flags
= PF_R
| PF_X
;
2098 ph
->p_flags
= PF_R
| PF_W
;
2099 ph
->p_align
= s_align
;
2101 /* Decide the layout of sections loaded in memory. This must
2102 be done before program headers are filled since they contain
2103 info about the layout. We do the following ordering: interp,
2104 symbol tables, relocations, progbits, nobits */
2105 /* XXX: do faster and simpler sorting */
2106 for(k
= 0; k
< 5; k
++) {
2107 for(i
= 1; i
< s1
->nb_sections
; i
++) {
2108 s
= s1
->sections
[i
];
2109 /* compute if section should be included */
2111 if ((s
->sh_flags
& (SHF_ALLOC
| SHF_WRITE
)) !=
2115 if ((s
->sh_flags
& (SHF_ALLOC
| SHF_WRITE
)) !=
2116 (SHF_ALLOC
| SHF_WRITE
))
2122 } else if (s
->sh_type
== SHT_DYNSYM
||
2123 s
->sh_type
== SHT_STRTAB
||
2124 s
->sh_type
== SHT_HASH
) {
2127 } else if (s
->sh_type
== SHT_RELX
) {
2130 } else if (s
->sh_type
== SHT_NOBITS
) {
2137 sec_order
[sh_order_index
++] = i
;
2139 /* section matches: we align it and add its size */
2141 addr
= (addr
+ s
->sh_addralign
- 1) &
2142 ~(s
->sh_addralign
- 1);
2143 file_offset
+= (int) ( addr
- tmp
);
2144 s
->sh_offset
= file_offset
;
2147 /* update program header infos */
2148 if (ph
->p_offset
== 0) {
2149 ph
->p_offset
= file_offset
;
2151 ph
->p_paddr
= ph
->p_vaddr
;
2153 /* update dynamic relocation infos */
2154 if (s
->sh_type
== SHT_RELX
) {
2155 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2156 if (!strcmp(strsec
->data
+ s
->sh_name
, ".rel.got")) {
2157 dyninf
->rel_addr
= addr
;
2158 dyninf
->rel_size
+= s
->sh_size
; /* XXX only first rel. */
2160 if (!strcmp(strsec
->data
+ s
->sh_name
, ".rel.bss")) {
2161 dyninf
->bss_addr
= addr
;
2162 dyninf
->bss_size
= s
->sh_size
; /* XXX only first rel. */
2165 if (dyninf
->rel_size
== 0)
2166 dyninf
->rel_addr
= addr
;
2167 dyninf
->rel_size
+= s
->sh_size
;
2171 if (s
->sh_type
!= SHT_NOBITS
)
2172 file_offset
+= s
->sh_size
;
2176 /* Make the first PT_LOAD segment include the program
2177 headers itself (and the ELF header as well), it'll
2178 come out with same memory use but will make various
2179 tools like binutils strip work better. */
2180 ph
->p_offset
&= ~(ph
->p_align
- 1);
2181 ph
->p_vaddr
&= ~(ph
->p_align
- 1);
2182 ph
->p_paddr
&= ~(ph
->p_align
- 1);
2184 ph
->p_filesz
= file_offset
- ph
->p_offset
;
2185 ph
->p_memsz
= addr
- ph
->p_vaddr
;
2188 if (s1
->output_format
== TCC_OUTPUT_FORMAT_ELF
) {
2189 /* if in the middle of a page, we duplicate the page in
2190 memory so that one copy is RX and the other is RW */
2191 if ((addr
& (s_align
- 1)) != 0)
2194 addr
= (addr
+ s_align
- 1) & ~(s_align
- 1);
2195 file_offset
= (file_offset
+ s_align
- 1) & ~(s_align
- 1);
2201 /* all other sections come after */
2202 for(i
= 1; i
< s1
->nb_sections
; i
++) {
2203 s
= s1
->sections
[i
];
2204 if (phnum
> 0 && (s
->sh_flags
& SHF_ALLOC
))
2206 sec_order
[sh_order_index
++] = i
;
2208 file_offset
= (file_offset
+ s
->sh_addralign
- 1) &
2209 ~(s
->sh_addralign
- 1);
2210 s
->sh_offset
= file_offset
;
2211 if (s
->sh_type
!= SHT_NOBITS
)
2212 file_offset
+= s
->sh_size
;
2218 static void fill_unloadable_phdr(ElfW(Phdr
) *phdr
, int phnum
, Section
*interp
,
2223 /* if interpreter, then add corresponding program header */
2229 int len
= phnum
* sizeof(ElfW(Phdr
));
2231 ph
->p_type
= PT_PHDR
;
2232 ph
->p_offset
= sizeof(ElfW(Ehdr
));
2233 ph
->p_vaddr
= interp
->sh_addr
- len
;
2234 ph
->p_paddr
= ph
->p_vaddr
;
2235 ph
->p_filesz
= ph
->p_memsz
= len
;
2236 ph
->p_flags
= PF_R
| PF_X
;
2237 ph
->p_align
= 4; /* interp->sh_addralign; */
2241 ph
->p_type
= PT_INTERP
;
2242 ph
->p_offset
= interp
->sh_offset
;
2243 ph
->p_vaddr
= interp
->sh_addr
;
2244 ph
->p_paddr
= ph
->p_vaddr
;
2245 ph
->p_filesz
= interp
->sh_size
;
2246 ph
->p_memsz
= interp
->sh_size
;
2248 ph
->p_align
= interp
->sh_addralign
;
2251 /* if dynamic section, then add corresponding program header */
2253 ph
= &phdr
[phnum
- 1];
2255 ph
->p_type
= PT_DYNAMIC
;
2256 ph
->p_offset
= dynamic
->sh_offset
;
2257 ph
->p_vaddr
= dynamic
->sh_addr
;
2258 ph
->p_paddr
= ph
->p_vaddr
;
2259 ph
->p_filesz
= dynamic
->sh_size
;
2260 ph
->p_memsz
= dynamic
->sh_size
;
2261 ph
->p_flags
= PF_R
| PF_W
;
2262 ph
->p_align
= dynamic
->sh_addralign
;
2266 /* Fill the dynamic section with tags describing the address and size of
2268 static void fill_dynamic(TCCState
*s1
, struct dyn_inf
*dyninf
)
2272 dynamic
= dyninf
->dynamic
;
2274 /* put dynamic section entries */
2275 dynamic
->data_offset
= dyninf
->dyn_rel_off
;
2276 put_dt(dynamic
, DT_HASH
, s1
->dynsym
->hash
->sh_addr
);
2277 put_dt(dynamic
, DT_STRTAB
, dyninf
->dynstr
->sh_addr
);
2278 put_dt(dynamic
, DT_SYMTAB
, s1
->dynsym
->sh_addr
);
2279 put_dt(dynamic
, DT_STRSZ
, dyninf
->dynstr
->data_offset
);
2280 put_dt(dynamic
, DT_SYMENT
, sizeof(ElfW(Sym
)));
2281 #if defined(TCC_TARGET_ARM64) || defined(TCC_TARGET_X86_64)
2282 put_dt(dynamic
, DT_RELA
, dyninf
->rel_addr
);
2283 put_dt(dynamic
, DT_RELASZ
, dyninf
->rel_size
);
2284 put_dt(dynamic
, DT_RELAENT
, sizeof(ElfW_Rel
));
2286 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2287 put_dt(dynamic
, DT_PLTGOT
, s1
->got
->sh_addr
);
2288 put_dt(dynamic
, DT_PLTRELSZ
, dyninf
->rel_size
);
2289 put_dt(dynamic
, DT_JMPREL
, dyninf
->rel_addr
);
2290 put_dt(dynamic
, DT_PLTREL
, DT_REL
);
2291 put_dt(dynamic
, DT_REL
, dyninf
->bss_addr
);
2292 put_dt(dynamic
, DT_RELSZ
, dyninf
->bss_size
);
2294 put_dt(dynamic
, DT_REL
, dyninf
->rel_addr
);
2295 put_dt(dynamic
, DT_RELSZ
, dyninf
->rel_size
);
2296 put_dt(dynamic
, DT_RELENT
, sizeof(ElfW_Rel
));
2300 put_dt(dynamic
, DT_DEBUG
, 0);
2301 put_dt(dynamic
, DT_NULL
, 0);
2304 /* Relocate remaining sections and symbols (that is those not related to
2306 static int final_sections_reloc(TCCState
*s1
)
2311 relocate_syms(s1
, 0);
2313 if (s1
->nb_errors
!= 0)
2316 /* relocate sections */
2317 /* XXX: ignore sections with allocated relocations ? */
2318 for(i
= 1; i
< s1
->nb_sections
; i
++) {
2319 s
= s1
->sections
[i
];
2320 #ifdef TCC_TARGET_I386
2321 if (s
->reloc
&& s
!= s1
->got
&& (s
->sh_flags
& SHF_ALLOC
)) //gr
2322 /* On X86 gdb 7.3 works in any case but gdb 6.6 will crash if SHF_ALLOC
2323 checking is removed */
2325 if (s
->reloc
&& s
!= s1
->got
)
2326 /* On X86_64 gdb 7.3 will crash if SHF_ALLOC checking is present */
2328 relocate_section(s1
, s
);
2331 /* relocate relocation entries if the relocation tables are
2332 allocated in the executable */
2333 for(i
= 1; i
< s1
->nb_sections
; i
++) {
2334 s
= s1
->sections
[i
];
2335 if ((s
->sh_flags
& SHF_ALLOC
) &&
2336 s
->sh_type
== SHT_RELX
) {
2337 relocate_rel(s1
, s
);
2343 /* Create an ELF file on disk.
2344 This function handle ELF specific layout requirements */
2345 static void tcc_output_elf(TCCState
*s1
, FILE *f
, int phnum
, ElfW(Phdr
) *phdr
,
2346 int file_offset
, int *sec_order
)
2348 int i
, shnum
, offset
, size
, file_type
;
2351 ElfW(Shdr
) shdr
, *sh
;
2353 file_type
= s1
->output_type
;
2354 shnum
= s1
->nb_sections
;
2356 memset(&ehdr
, 0, sizeof(ehdr
));
2359 ehdr
.e_phentsize
= sizeof(ElfW(Phdr
));
2360 ehdr
.e_phnum
= phnum
;
2361 ehdr
.e_phoff
= sizeof(ElfW(Ehdr
));
2365 file_offset
= (file_offset
+ 3) & -4;
2368 ehdr
.e_ident
[0] = ELFMAG0
;
2369 ehdr
.e_ident
[1] = ELFMAG1
;
2370 ehdr
.e_ident
[2] = ELFMAG2
;
2371 ehdr
.e_ident
[3] = ELFMAG3
;
2372 ehdr
.e_ident
[4] = ELFCLASSW
;
2373 ehdr
.e_ident
[5] = ELFDATA2LSB
;
2374 ehdr
.e_ident
[6] = EV_CURRENT
;
2375 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2376 ehdr
.e_ident
[EI_OSABI
] = ELFOSABI_FREEBSD
;
2378 #ifdef TCC_TARGET_ARM
2380 ehdr
.e_ident
[EI_OSABI
] = 0;
2381 ehdr
.e_flags
= EF_ARM_EABI_VER4
;
2382 if (file_type
== TCC_OUTPUT_EXE
|| file_type
== TCC_OUTPUT_DLL
)
2383 ehdr
.e_flags
|= EF_ARM_HASENTRY
;
2384 if (s1
->float_abi
== ARM_HARD_FLOAT
)
2385 ehdr
.e_flags
|= EF_ARM_VFP_FLOAT
;
2387 ehdr
.e_flags
|= EF_ARM_SOFT_FLOAT
;
2389 ehdr
.e_ident
[EI_OSABI
] = ELFOSABI_ARM
;
2394 case TCC_OUTPUT_EXE
:
2395 ehdr
.e_type
= ET_EXEC
;
2396 ehdr
.e_entry
= get_elf_sym_addr(s1
, "_start", 1);
2398 case TCC_OUTPUT_DLL
:
2399 ehdr
.e_type
= ET_DYN
;
2400 ehdr
.e_entry
= text_section
->sh_addr
; /* XXX: is it correct ? */
2402 case TCC_OUTPUT_OBJ
:
2403 ehdr
.e_type
= ET_REL
;
2406 ehdr
.e_machine
= EM_TCC_TARGET
;
2407 ehdr
.e_version
= EV_CURRENT
;
2408 ehdr
.e_shoff
= file_offset
;
2409 ehdr
.e_ehsize
= sizeof(ElfW(Ehdr
));
2410 ehdr
.e_shentsize
= sizeof(ElfW(Shdr
));
2411 ehdr
.e_shnum
= shnum
;
2412 ehdr
.e_shstrndx
= shnum
- 1;
2414 fwrite(&ehdr
, 1, sizeof(ElfW(Ehdr
)), f
);
2415 fwrite(phdr
, 1, phnum
* sizeof(ElfW(Phdr
)), f
);
2416 offset
= sizeof(ElfW(Ehdr
)) + phnum
* sizeof(ElfW(Phdr
));
2418 sort_syms(s1
, symtab_section
);
2419 for(i
= 1; i
< s1
->nb_sections
; i
++) {
2420 s
= s1
->sections
[sec_order
[i
]];
2421 if (s
->sh_type
!= SHT_NOBITS
) {
2422 if (s
->sh_type
== SHT_DYNSYM
)
2423 patch_dynsym_undef(s1
, s
);
2424 while (offset
< s
->sh_offset
) {
2429 fwrite(s
->data
, 1, size
, f
);
2434 /* output section headers */
2435 while (offset
< ehdr
.e_shoff
) {
2440 for(i
= 0; i
< s1
->nb_sections
; i
++) {
2442 memset(sh
, 0, sizeof(ElfW(Shdr
)));
2443 s
= s1
->sections
[i
];
2445 sh
->sh_name
= s
->sh_name
;
2446 sh
->sh_type
= s
->sh_type
;
2447 sh
->sh_flags
= s
->sh_flags
;
2448 sh
->sh_entsize
= s
->sh_entsize
;
2449 sh
->sh_info
= s
->sh_info
;
2451 sh
->sh_link
= s
->link
->sh_num
;
2452 sh
->sh_addralign
= s
->sh_addralign
;
2453 sh
->sh_addr
= s
->sh_addr
;
2454 sh
->sh_offset
= s
->sh_offset
;
2455 sh
->sh_size
= s
->sh_size
;
2457 fwrite(sh
, 1, sizeof(ElfW(Shdr
)), f
);
2461 /* Write an elf, coff or "binary" file */
2462 static int tcc_write_elf_file(TCCState
*s1
, const char *filename
, int phnum
,
2463 ElfW(Phdr
) *phdr
, int file_offset
, int *sec_order
)
2465 int fd
, mode
, file_type
;
2468 file_type
= s1
->output_type
;
2469 if (file_type
== TCC_OUTPUT_OBJ
)
2474 fd
= open(filename
, O_WRONLY
| O_CREAT
| O_TRUNC
| O_BINARY
, mode
);
2476 tcc_error_noabort("could not write '%s'", filename
);
2479 f
= fdopen(fd
, "wb");
2481 printf("<- %s\n", filename
);
2483 #ifdef TCC_TARGET_COFF
2484 if (s1
->output_format
== TCC_OUTPUT_FORMAT_COFF
)
2485 tcc_output_coff(s1
, f
);
2488 if (s1
->output_format
== TCC_OUTPUT_FORMAT_ELF
)
2489 tcc_output_elf(s1
, f
, phnum
, phdr
, file_offset
, sec_order
);
2491 tcc_output_binary(s1
, f
, sec_order
);
2497 /* Output an elf, coff or binary file */
2498 /* XXX: suppress unneeded sections */
2499 static int elf_output_file(TCCState
*s1
, const char *filename
)
2501 int i
, ret
, phnum
, shnum
, file_type
, file_offset
, *sec_order
;
2502 struct dyn_inf dyninf
;
2505 Section
*strsec
, *interp
, *dynamic
, *dynstr
;
2507 file_type
= s1
->output_type
;
2510 /* if linking, also link in runtime libraries (libc, libgcc, etc.) */
2511 if (file_type
!= TCC_OUTPUT_OBJ
) {
2512 tcc_add_runtime(s1
);
2517 interp
= dynamic
= dynstr
= NULL
; /* avoid warning */
2518 dyninf
.dyn_rel_off
= 0; /* avoid warning */
2520 if (file_type
!= TCC_OUTPUT_OBJ
) {
2521 relocate_common_syms();
2523 tcc_add_linker_symbols(s1
);
2525 if (!s1
->static_link
) {
2526 if (file_type
== TCC_OUTPUT_EXE
) {
2528 /* allow override the dynamic loader */
2529 const char *elfint
= getenv("LD_SO");
2531 elfint
= DEFAULT_ELFINTERP(s1
);
2532 /* add interpreter section only if executable */
2533 interp
= new_section(s1
, ".interp", SHT_PROGBITS
, SHF_ALLOC
);
2534 interp
->sh_addralign
= 1;
2535 ptr
= section_ptr_add(interp
, 1 + strlen(elfint
));
2536 strcpy(ptr
, elfint
);
2539 /* add dynamic symbol table */
2540 s1
->dynsym
= new_symtab(s1
, ".dynsym", SHT_DYNSYM
, SHF_ALLOC
,
2542 ".hash", SHF_ALLOC
);
2543 dynstr
= s1
->dynsym
->link
;
2545 /* add dynamic section */
2546 dynamic
= new_section(s1
, ".dynamic", SHT_DYNAMIC
,
2547 SHF_ALLOC
| SHF_WRITE
);
2548 dynamic
->link
= dynstr
;
2549 dynamic
->sh_entsize
= sizeof(ElfW(Dyn
));
2553 if (file_type
== TCC_OUTPUT_EXE
) {
2554 bind_exe_dynsyms(s1
);
2556 if (s1
->nb_errors
) {
2561 bind_libs_dynsyms(s1
);
2562 } else /* shared library case: simply export all global symbols */
2563 export_global_syms(s1
);
2565 build_got_entries(s1
);
2567 /* add a list of needed dlls */
2568 for(i
= 0; i
< s1
->nb_loaded_dlls
; i
++) {
2569 DLLReference
*dllref
= s1
->loaded_dlls
[i
];
2570 if (dllref
->level
== 0)
2571 put_dt(dynamic
, DT_NEEDED
, put_elf_str(dynstr
, dllref
->name
));
2575 put_dt(dynamic
, DT_RPATH
, put_elf_str(dynstr
, s1
->rpath
));
2577 /* XXX: currently, since we do not handle PIC code, we
2578 must relocate the readonly segments */
2579 if (file_type
== TCC_OUTPUT_DLL
) {
2581 put_dt(dynamic
, DT_SONAME
, put_elf_str(dynstr
, s1
->soname
));
2582 put_dt(dynamic
, DT_TEXTREL
, 0);
2586 put_dt(dynamic
, DT_SYMBOLIC
, 0);
2588 /* add necessary space for other entries */
2589 dyninf
.dyn_rel_off
= dynamic
->data_offset
;
2590 dynamic
->data_offset
+= sizeof(ElfW(Dyn
)) * EXTRA_RELITEMS
;
2592 /* still need to build got entries in case of static link */
2593 build_got_entries(s1
);
2597 /* we add a section for symbols */
2598 strsec
= new_section(s1
, ".shstrtab", SHT_STRTAB
, 0);
2599 put_elf_str(strsec
, "");
2601 /* compute number of sections */
2602 shnum
= s1
->nb_sections
;
2604 /* this array is used to reorder sections in the output file */
2605 sec_order
= tcc_malloc(sizeof(int) * shnum
);
2608 /* compute number of program headers */
2611 case TCC_OUTPUT_OBJ
:
2614 case TCC_OUTPUT_EXE
:
2615 if (!s1
->static_link
)
2616 phnum
= 4 + HAVE_PHDR
;
2620 case TCC_OUTPUT_DLL
:
2625 /* Allocate strings for section names */
2626 alloc_sec_names(s1
, file_type
, strsec
);
2628 /* allocate program segment headers */
2629 phdr
= tcc_mallocz(phnum
* sizeof(ElfW(Phdr
)));
2631 /* compute section to program header mapping */
2632 file_offset
= layout_sections(s1
, phdr
, phnum
, interp
, strsec
, &dyninf
,
2635 /* Fill remaining program header and finalize relocation related to dynamic
2638 fill_unloadable_phdr(phdr
, phnum
, interp
, dynamic
);
2640 dyninf
.dynamic
= dynamic
;
2641 dyninf
.dynstr
= dynstr
;
2643 fill_dynamic(s1
, &dyninf
);
2645 /* put in GOT the dynamic section address and relocate PLT */
2646 put32(s1
->got
->data
, dynamic
->sh_addr
);
2647 if (file_type
== TCC_OUTPUT_EXE
2648 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
2649 || file_type
== TCC_OUTPUT_DLL
2654 /* relocate symbols in .dynsym now that final addresses are known */
2655 for_each_elem(s1
->dynsym
, 1, sym
, ElfW(Sym
)) {
2656 if (sym
->st_shndx
== SHN_UNDEF
) {
2657 /* relocate to PLT if symbol corresponds to a PLT entry,
2658 but not if it's a weak symbol */
2659 if (ELFW(ST_BIND
)(sym
->st_info
) == STB_WEAK
)
2661 else if (sym
->st_value
)
2662 sym
->st_value
+= s1
->plt
->sh_addr
;
2663 } else if (sym
->st_shndx
< SHN_LORESERVE
) {
2664 /* do symbol relocation */
2665 sym
->st_value
+= s1
->sections
[sym
->st_shndx
]->sh_addr
;
2671 /* if building executable or DLL, then relocate each section
2672 except the GOT which is already relocated */
2673 if (file_type
!= TCC_OUTPUT_OBJ
) {
2674 ret
= final_sections_reloc(s1
);
2679 /* Perform relocation to GOT or PLT entries */
2680 if (file_type
== TCC_OUTPUT_EXE
&& s1
->static_link
)
2683 /* Create the ELF file with name 'filename' */
2684 ret
= tcc_write_elf_file(s1
, filename
, phnum
, phdr
, file_offset
, sec_order
);
2686 tcc_free(s1
->symtab_to_dynsym
);
2687 tcc_free(sec_order
);
2689 tcc_free(s1
->sym_attrs
);
2690 s1
->sym_attrs
= NULL
;
2694 LIBTCCAPI
int tcc_output_file(TCCState
*s
, const char *filename
)
2697 #ifdef TCC_TARGET_PE
2698 if (s
->output_type
!= TCC_OUTPUT_OBJ
) {
2699 ret
= pe_output_file(s
, filename
);
2702 ret
= elf_output_file(s
, filename
);
2706 static void *load_data(int fd
, unsigned long file_offset
, unsigned long size
)
2710 data
= tcc_malloc(size
);
2711 lseek(fd
, file_offset
, SEEK_SET
);
2712 read(fd
, data
, size
);
2716 typedef struct SectionMergeInfo
{
2717 Section
*s
; /* corresponding existing section */
2718 unsigned long offset
; /* offset of the new section in the existing section */
2719 uint8_t new_section
; /* true if section 's' was added */
2720 uint8_t link_once
; /* true if link once section */
2723 /* load an object file and merge it with current files */
2724 /* XXX: handle correctly stab (debug) info */
2725 ST_FUNC
int tcc_load_object_file(TCCState
*s1
,
2726 int fd
, unsigned long file_offset
)
2729 ElfW(Shdr
) *shdr
, *sh
;
2730 int size
, i
, j
, offset
, offseti
, nb_syms
, sym_index
, ret
;
2731 unsigned char *strsec
, *strtab
;
2732 int *old_to_new_syms
;
2733 char *sh_name
, *name
;
2734 SectionMergeInfo
*sm_table
, *sm
;
2735 ElfW(Sym
) *sym
, *symtab
;
2742 stab_index
= stabstr_index
= 0;
2744 if (read(fd
, &ehdr
, sizeof(ehdr
)) != sizeof(ehdr
))
2746 if (ehdr
.e_ident
[0] != ELFMAG0
||
2747 ehdr
.e_ident
[1] != ELFMAG1
||
2748 ehdr
.e_ident
[2] != ELFMAG2
||
2749 ehdr
.e_ident
[3] != ELFMAG3
)
2751 /* test if object file */
2752 if (ehdr
.e_type
!= ET_REL
)
2754 /* test CPU specific stuff */
2755 if (ehdr
.e_ident
[5] != ELFDATA2LSB
||
2756 ehdr
.e_machine
!= EM_TCC_TARGET
) {
2758 tcc_error_noabort("invalid object file");
2762 shdr
= load_data(fd
, file_offset
+ ehdr
.e_shoff
,
2763 sizeof(ElfW(Shdr
)) * ehdr
.e_shnum
);
2764 sm_table
= tcc_mallocz(sizeof(SectionMergeInfo
) * ehdr
.e_shnum
);
2766 /* load section names */
2767 sh
= &shdr
[ehdr
.e_shstrndx
];
2768 strsec
= load_data(fd
, file_offset
+ sh
->sh_offset
, sh
->sh_size
);
2770 /* load symtab and strtab */
2771 old_to_new_syms
= NULL
;
2775 for(i
= 1; i
< ehdr
.e_shnum
; i
++) {
2777 if (sh
->sh_type
== SHT_SYMTAB
) {
2779 tcc_error_noabort("object must contain only one symtab");
2784 nb_syms
= sh
->sh_size
/ sizeof(ElfW(Sym
));
2785 symtab
= load_data(fd
, file_offset
+ sh
->sh_offset
, sh
->sh_size
);
2786 sm_table
[i
].s
= symtab_section
;
2788 /* now load strtab */
2789 sh
= &shdr
[sh
->sh_link
];
2790 strtab
= load_data(fd
, file_offset
+ sh
->sh_offset
, sh
->sh_size
);
2794 /* now examine each section and try to merge its content with the
2796 for(i
= 1; i
< ehdr
.e_shnum
; i
++) {
2797 /* no need to examine section name strtab */
2798 if (i
== ehdr
.e_shstrndx
)
2801 sh_name
= (char *) strsec
+ sh
->sh_name
;
2802 /* ignore sections types we do not handle */
2803 if (sh
->sh_type
!= SHT_PROGBITS
&&
2804 sh
->sh_type
!= SHT_RELX
&&
2806 sh
->sh_type
!= SHT_ARM_EXIDX
&&
2808 sh
->sh_type
!= SHT_NOBITS
&&
2809 sh
->sh_type
!= SHT_PREINIT_ARRAY
&&
2810 sh
->sh_type
!= SHT_INIT_ARRAY
&&
2811 sh
->sh_type
!= SHT_FINI_ARRAY
&&
2812 strcmp(sh_name
, ".stabstr")
2815 if (sh
->sh_addralign
< 1)
2816 sh
->sh_addralign
= 1;
2817 /* find corresponding section, if any */
2818 for(j
= 1; j
< s1
->nb_sections
;j
++) {
2819 s
= s1
->sections
[j
];
2820 if (!strcmp(s
->name
, sh_name
)) {
2821 if (!strncmp(sh_name
, ".gnu.linkonce",
2822 sizeof(".gnu.linkonce") - 1)) {
2823 /* if a 'linkonce' section is already present, we
2824 do not add it again. It is a little tricky as
2825 symbols can still be defined in
2827 sm_table
[i
].link_once
= 1;
2834 /* not found: create new section */
2835 s
= new_section(s1
, sh_name
, sh
->sh_type
, sh
->sh_flags
);
2836 /* take as much info as possible from the section. sh_link and
2837 sh_info will be updated later */
2838 s
->sh_addralign
= sh
->sh_addralign
;
2839 s
->sh_entsize
= sh
->sh_entsize
;
2840 sm_table
[i
].new_section
= 1;
2842 if (sh
->sh_type
!= s
->sh_type
) {
2843 tcc_error_noabort("invalid section type");
2847 /* align start of section */
2848 offset
= s
->data_offset
;
2850 if (0 == strcmp(sh_name
, ".stab")) {
2854 if (0 == strcmp(sh_name
, ".stabstr")) {
2859 size
= sh
->sh_addralign
- 1;
2860 offset
= (offset
+ size
) & ~size
;
2861 if (sh
->sh_addralign
> s
->sh_addralign
)
2862 s
->sh_addralign
= sh
->sh_addralign
;
2863 s
->data_offset
= offset
;
2865 sm_table
[i
].offset
= offset
;
2867 /* concatenate sections */
2869 if (sh
->sh_type
!= SHT_NOBITS
) {
2871 lseek(fd
, file_offset
+ sh
->sh_offset
, SEEK_SET
);
2872 ptr
= section_ptr_add(s
, size
);
2873 read(fd
, ptr
, size
);
2875 s
->data_offset
+= size
;
2880 /* gr relocate stab strings */
2881 if (stab_index
&& stabstr_index
) {
2884 s
= sm_table
[stab_index
].s
;
2885 a
= (Stab_Sym
*)(s
->data
+ sm_table
[stab_index
].offset
);
2886 b
= (Stab_Sym
*)(s
->data
+ s
->data_offset
);
2887 o
= sm_table
[stabstr_index
].offset
;
2889 a
->n_strx
+= o
, a
++;
2892 /* second short pass to update sh_link and sh_info fields of new
2894 for(i
= 1; i
< ehdr
.e_shnum
; i
++) {
2896 if (!s
|| !sm_table
[i
].new_section
)
2899 if (sh
->sh_link
> 0)
2900 s
->link
= sm_table
[sh
->sh_link
].s
;
2901 if (sh
->sh_type
== SHT_RELX
) {
2902 s
->sh_info
= sm_table
[sh
->sh_info
].s
->sh_num
;
2903 /* update backward link */
2904 s1
->sections
[s
->sh_info
]->reloc
= s
;
2909 /* resolve symbols */
2910 old_to_new_syms
= tcc_mallocz(nb_syms
* sizeof(int));
2913 for(i
= 1; i
< nb_syms
; i
++, sym
++) {
2914 if (sym
->st_shndx
!= SHN_UNDEF
&&
2915 sym
->st_shndx
< SHN_LORESERVE
) {
2916 sm
= &sm_table
[sym
->st_shndx
];
2917 if (sm
->link_once
) {
2918 /* if a symbol is in a link once section, we use the
2919 already defined symbol. It is very important to get
2920 correct relocations */
2921 if (ELFW(ST_BIND
)(sym
->st_info
) != STB_LOCAL
) {
2922 name
= (char *) strtab
+ sym
->st_name
;
2923 sym_index
= find_elf_sym(symtab_section
, name
);
2925 old_to_new_syms
[i
] = sym_index
;
2929 /* if no corresponding section added, no need to add symbol */
2932 /* convert section number */
2933 sym
->st_shndx
= sm
->s
->sh_num
;
2935 sym
->st_value
+= sm
->offset
;
2938 name
= (char *) strtab
+ sym
->st_name
;
2939 sym_index
= add_elf_sym(symtab_section
, sym
->st_value
, sym
->st_size
,
2940 sym
->st_info
, sym
->st_other
,
2941 sym
->st_shndx
, name
);
2942 old_to_new_syms
[i
] = sym_index
;
2945 /* third pass to patch relocation entries */
2946 for(i
= 1; i
< ehdr
.e_shnum
; i
++) {
2951 offset
= sm_table
[i
].offset
;
2952 switch(s
->sh_type
) {
2954 /* take relocation offset information */
2955 offseti
= sm_table
[sh
->sh_info
].offset
;
2956 for_each_elem(s
, (offset
/ sizeof(*rel
)), rel
, ElfW_Rel
) {
2959 /* convert symbol index */
2960 type
= ELFW(R_TYPE
)(rel
->r_info
);
2961 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
2962 /* NOTE: only one symtab assumed */
2963 if (sym_index
>= nb_syms
)
2965 sym_index
= old_to_new_syms
[sym_index
];
2966 /* ignore link_once in rel section. */
2967 if (!sym_index
&& !sm
->link_once
2968 #ifdef TCC_TARGET_ARM
2969 && type
!= R_ARM_V4BX
2973 tcc_error_noabort("Invalid relocation entry [%2d] '%s' @ %.8x",
2974 i
, strsec
+ sh
->sh_name
, rel
->r_offset
);
2977 rel
->r_info
= ELFW(R_INFO
)(sym_index
, type
);
2978 /* offset the relocation offset */
2979 rel
->r_offset
+= offseti
;
2980 #ifdef TCC_TARGET_ARM
2981 /* Jumps and branches from a Thumb code to a PLT entry need
2982 special handling since PLT entries are ARM code.
2983 Unconditional bl instructions referencing PLT entries are
2984 handled by converting these instructions into blx
2985 instructions. Other case of instructions referencing a PLT
2986 entry require to add a Thumb stub before the PLT entry to
2987 switch to ARM mode. We set bit plt_thumb_stub of the
2988 attribute of a symbol to indicate such a case. */
2989 if (type
== R_ARM_THM_JUMP24
)
2990 alloc_sym_attr(s1
, sym_index
)->plt_thumb_stub
= 1;
3003 tcc_free(old_to_new_syms
);
3010 typedef struct ArchiveHeader
{
3011 char ar_name
[16]; /* name of this member */
3012 char ar_date
[12]; /* file mtime */
3013 char ar_uid
[6]; /* owner uid; printed as decimal */
3014 char ar_gid
[6]; /* owner gid; printed as decimal */
3015 char ar_mode
[8]; /* file mode, printed as octal */
3016 char ar_size
[10]; /* file size, printed as decimal */
3017 char ar_fmag
[2]; /* should contain ARFMAG */
3020 static int get_be32(const uint8_t *b
)
3022 return b
[3] | (b
[2] << 8) | (b
[1] << 16) | (b
[0] << 24);
3025 /* load only the objects which resolve undefined symbols */
3026 static int tcc_load_alacarte(TCCState
*s1
, int fd
, int size
)
3028 int i
, bound
, nsyms
, sym_index
, off
, ret
;
3030 const char *ar_names
, *p
;
3031 const uint8_t *ar_index
;
3034 data
= tcc_malloc(size
);
3035 if (read(fd
, data
, size
) != size
)
3037 nsyms
= get_be32(data
);
3038 ar_index
= data
+ 4;
3039 ar_names
= (char *) ar_index
+ nsyms
* 4;
3043 for(p
= ar_names
, i
= 0; i
< nsyms
; i
++, p
+= strlen(p
)+1) {
3044 sym_index
= find_elf_sym(symtab_section
, p
);
3046 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
3047 if(sym
->st_shndx
== SHN_UNDEF
) {
3048 off
= get_be32(ar_index
+ i
* 4) + sizeof(ArchiveHeader
);
3050 lseek(fd
, off
, SEEK_SET
);
3051 if(tcc_load_object_file(s1
, fd
, off
) < 0) {
3066 /* load a '.a' file */
3067 ST_FUNC
int tcc_load_archive(TCCState
*s1
, int fd
)
3074 unsigned long file_offset
;
3076 /* skip magic which was already checked */
3077 read(fd
, magic
, sizeof(magic
));
3080 len
= read(fd
, &hdr
, sizeof(hdr
));
3083 if (len
!= sizeof(hdr
)) {
3084 tcc_error_noabort("invalid archive");
3087 memcpy(ar_size
, hdr
.ar_size
, sizeof(hdr
.ar_size
));
3088 ar_size
[sizeof(hdr
.ar_size
)] = '\0';
3089 size
= strtol(ar_size
, NULL
, 0);
3090 memcpy(ar_name
, hdr
.ar_name
, sizeof(hdr
.ar_name
));
3091 for(i
= sizeof(hdr
.ar_name
) - 1; i
>= 0; i
--) {
3092 if (ar_name
[i
] != ' ')
3095 ar_name
[i
+ 1] = '\0';
3096 file_offset
= lseek(fd
, 0, SEEK_CUR
);
3098 size
= (size
+ 1) & ~1;
3099 if (!strcmp(ar_name
, "/")) {
3100 /* coff symbol table : we handle it */
3101 if(s1
->alacarte_link
)
3102 return tcc_load_alacarte(s1
, fd
, size
);
3103 } else if (!strcmp(ar_name
, "//") ||
3104 !strcmp(ar_name
, "__.SYMDEF") ||
3105 !strcmp(ar_name
, "__.SYMDEF/") ||
3106 !strcmp(ar_name
, "ARFILENAMES/")) {
3107 /* skip symbol table or archive names */
3109 if (tcc_load_object_file(s1
, fd
, file_offset
) < 0)
3112 lseek(fd
, file_offset
+ size
, SEEK_SET
);
3117 #ifndef TCC_TARGET_PE
3118 /* load a DLL and all referenced DLLs. 'level = 0' means that the DLL
3119 is referenced by the user (so it should be added as DT_NEEDED in
3120 the generated ELF file) */
3121 ST_FUNC
int tcc_load_dll(TCCState
*s1
, int fd
, const char *filename
, int level
)
3124 ElfW(Shdr
) *shdr
, *sh
, *sh1
;
3125 int i
, j
, nb_syms
, nb_dts
, sym_bind
, ret
;
3126 ElfW(Sym
) *sym
, *dynsym
;
3127 ElfW(Dyn
) *dt
, *dynamic
;
3128 unsigned char *dynstr
;
3129 const char *name
, *soname
;
3130 DLLReference
*dllref
;
3132 read(fd
, &ehdr
, sizeof(ehdr
));
3134 /* test CPU specific stuff */
3135 if (ehdr
.e_ident
[5] != ELFDATA2LSB
||
3136 ehdr
.e_machine
!= EM_TCC_TARGET
) {
3137 tcc_error_noabort("bad architecture");
3142 shdr
= load_data(fd
, ehdr
.e_shoff
, sizeof(ElfW(Shdr
)) * ehdr
.e_shnum
);
3144 /* load dynamic section and dynamic symbols */
3148 dynsym
= NULL
; /* avoid warning */
3149 dynstr
= NULL
; /* avoid warning */
3150 for(i
= 0, sh
= shdr
; i
< ehdr
.e_shnum
; i
++, sh
++) {
3151 switch(sh
->sh_type
) {
3153 nb_dts
= sh
->sh_size
/ sizeof(ElfW(Dyn
));
3154 dynamic
= load_data(fd
, sh
->sh_offset
, sh
->sh_size
);
3157 nb_syms
= sh
->sh_size
/ sizeof(ElfW(Sym
));
3158 dynsym
= load_data(fd
, sh
->sh_offset
, sh
->sh_size
);
3159 sh1
= &shdr
[sh
->sh_link
];
3160 dynstr
= load_data(fd
, sh1
->sh_offset
, sh1
->sh_size
);
3167 /* compute the real library name */
3168 soname
= tcc_basename(filename
);
3170 for(i
= 0, dt
= dynamic
; i
< nb_dts
; i
++, dt
++) {
3171 if (dt
->d_tag
== DT_SONAME
) {
3172 soname
= (char *) dynstr
+ dt
->d_un
.d_val
;
3176 /* if the dll is already loaded, do not load it */
3177 for(i
= 0; i
< s1
->nb_loaded_dlls
; i
++) {
3178 dllref
= s1
->loaded_dlls
[i
];
3179 if (!strcmp(soname
, dllref
->name
)) {
3180 /* but update level if needed */
3181 if (level
< dllref
->level
)
3182 dllref
->level
= level
;
3188 /* add the dll and its level */
3189 dllref
= tcc_mallocz(sizeof(DLLReference
) + strlen(soname
));
3190 dllref
->level
= level
;
3191 strcpy(dllref
->name
, soname
);
3192 dynarray_add((void ***)&s1
->loaded_dlls
, &s1
->nb_loaded_dlls
, dllref
);
3194 /* add dynamic symbols in dynsym_section */
3195 for(i
= 1, sym
= dynsym
+ 1; i
< nb_syms
; i
++, sym
++) {
3196 sym_bind
= ELFW(ST_BIND
)(sym
->st_info
);
3197 if (sym_bind
== STB_LOCAL
)
3199 name
= (char *) dynstr
+ sym
->st_name
;
3200 add_elf_sym(s1
->dynsymtab_section
, sym
->st_value
, sym
->st_size
,
3201 sym
->st_info
, sym
->st_other
, sym
->st_shndx
, name
);
3204 /* load all referenced DLLs */
3205 for(i
= 0, dt
= dynamic
; i
< nb_dts
; i
++, dt
++) {
3208 name
= (char *) dynstr
+ dt
->d_un
.d_val
;
3209 for(j
= 0; j
< s1
->nb_loaded_dlls
; j
++) {
3210 dllref
= s1
->loaded_dlls
[j
];
3211 if (!strcmp(name
, dllref
->name
))
3212 goto already_loaded
;
3214 if (tcc_add_dll(s1
, name
, AFF_REFERENCED_DLL
) < 0) {
3215 tcc_error_noabort("referenced dll '%s' not found", name
);
3232 #define LD_TOK_NAME 256
3233 #define LD_TOK_EOF (-1)
3235 /* return next ld script token */
3236 static int ld_next(TCCState
*s1
, char *name
, int name_size
)
3254 file
->buf_ptr
= parse_comment(file
->buf_ptr
);
3255 ch
= file
->buf_ptr
[0];
3263 /* case 'a' ... 'z': */
3290 /* case 'A' ... 'z': */
3325 if (!((ch
>= 'a' && ch
<= 'z') ||
3326 (ch
>= 'A' && ch
<= 'Z') ||
3327 (ch
>= '0' && ch
<= '9') ||
3328 strchr("/.-_+=$:\\,~", ch
)))
3330 if ((q
- name
) < name_size
- 1) {
3349 static int ld_add_file(TCCState
*s1
, const char filename
[])
3353 ret
= tcc_add_file_internal(s1
, filename
, 0);
3355 ret
= tcc_add_dll(s1
, filename
, 0);
3359 static inline int new_undef_syms(void)
3362 ret
= new_undef_sym
;
3367 static int ld_add_file_list(TCCState
*s1
, const char *cmd
, int as_needed
)
3369 char filename
[1024], libname
[1024];
3370 int t
, group
, nblibs
= 0, ret
= 0;
3373 group
= !strcmp(cmd
, "GROUP");
3376 t
= ld_next(s1
, filename
, sizeof(filename
));
3379 t
= ld_next(s1
, filename
, sizeof(filename
));
3382 if (t
== LD_TOK_EOF
) {
3383 tcc_error_noabort("unexpected end of file");
3385 goto lib_parse_error
;
3386 } else if (t
== ')') {
3388 } else if (t
== '-') {
3389 t
= ld_next(s1
, filename
, sizeof(filename
));
3390 if ((t
!= LD_TOK_NAME
) || (filename
[0] != 'l')) {
3391 tcc_error_noabort("library name expected");
3393 goto lib_parse_error
;
3395 pstrcpy(libname
, sizeof libname
, &filename
[1]);
3396 if (s1
->static_link
) {
3397 snprintf(filename
, sizeof filename
, "lib%s.a", libname
);
3399 snprintf(filename
, sizeof filename
, "lib%s.so", libname
);
3401 } else if (t
!= LD_TOK_NAME
) {
3402 tcc_error_noabort("filename expected");
3404 goto lib_parse_error
;
3406 if (!strcmp(filename
, "AS_NEEDED")) {
3407 ret
= ld_add_file_list(s1
, cmd
, 1);
3409 goto lib_parse_error
;
3411 /* TODO: Implement AS_NEEDED support. Ignore it for now */
3413 ret
= ld_add_file(s1
, filename
);
3415 goto lib_parse_error
;
3417 /* Add the filename *and* the libname to avoid future conversions */
3418 dynarray_add((void ***) &libs
, &nblibs
, tcc_strdup(filename
));
3419 if (libname
[0] != '\0')
3420 dynarray_add((void ***) &libs
, &nblibs
, tcc_strdup(libname
));
3424 t
= ld_next(s1
, filename
, sizeof(filename
));
3426 t
= ld_next(s1
, filename
, sizeof(filename
));
3429 if (group
&& !as_needed
) {
3430 while (new_undef_syms()) {
3433 for (i
= 0; i
< nblibs
; i
++)
3434 ld_add_file(s1
, libs
[i
]);
3438 dynarray_reset(&libs
, &nblibs
);
3442 /* interpret a subset of GNU ldscripts to handle the dummy libc.so
3444 ST_FUNC
int tcc_load_ldscript(TCCState
*s1
)
3447 char filename
[1024];
3450 ch
= file
->buf_ptr
[0];
3453 t
= ld_next(s1
, cmd
, sizeof(cmd
));
3454 if (t
== LD_TOK_EOF
)
3456 else if (t
!= LD_TOK_NAME
)
3458 if (!strcmp(cmd
, "INPUT") ||
3459 !strcmp(cmd
, "GROUP")) {
3460 ret
= ld_add_file_list(s1
, cmd
, 0);
3463 } else if (!strcmp(cmd
, "OUTPUT_FORMAT") ||
3464 !strcmp(cmd
, "TARGET")) {
3465 /* ignore some commands */
3466 t
= ld_next(s1
, cmd
, sizeof(cmd
));
3470 t
= ld_next(s1
, filename
, sizeof(filename
));
3471 if (t
== LD_TOK_EOF
) {
3472 tcc_error_noabort("unexpected end of file");
3474 } else if (t
== ')') {
3484 #endif /* !TCC_TARGET_PE */