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", s1
->tcc_lib_path
, filename
);
1579 return tcc_add_file(s1
, buf
);
1582 /* add tcc runtime libraries */
1583 ST_FUNC
void tcc_add_runtime(TCCState
*s1
)
1586 if (!s1
->nostdlib
) {
1587 tcc_add_library(s1
, "c");
1588 #ifdef CONFIG_USE_LIBGCC
1589 if (!s1
->static_link
) {
1590 tcc_add_file(s1
, TCC_LIBGCC
);
1591 tcc_add_support(s1
, "libtcc1.a");
1593 tcc_add_support(s1
, "libtcc1.a");
1595 tcc_add_support(s1
, "libtcc1.a");
1599 /* tcc_add_bcheck tries to relocate a call to __bound_init in _init so
1600 libtcc1.a must be loaded before for __bound_init to be defined and
1601 crtn.o must be loaded after to not finalize _init too early. */
1604 if (!s1
->nostdlib
) {
1605 /* add crt end if not memory output */
1606 if (s1
->output_type
!= TCC_OUTPUT_MEMORY
)
1607 tcc_add_crt(s1
, "crtn.o");
1611 /* add various standard linker symbols (must be done after the
1612 sections are filled (for example after allocating common
1614 ST_FUNC
void tcc_add_linker_symbols(TCCState
*s1
)
1620 add_elf_sym(symtab_section
,
1621 text_section
->data_offset
, 0,
1622 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1623 text_section
->sh_num
, "_etext");
1624 add_elf_sym(symtab_section
,
1625 data_section
->data_offset
, 0,
1626 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1627 data_section
->sh_num
, "_edata");
1628 add_elf_sym(symtab_section
,
1629 bss_section
->data_offset
, 0,
1630 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1631 bss_section
->sh_num
, "_end");
1632 /* horrible new standard ldscript defines */
1633 add_init_array_defines(s1
, ".preinit_array");
1634 add_init_array_defines(s1
, ".init_array");
1635 add_init_array_defines(s1
, ".fini_array");
1637 /* add start and stop symbols for sections whose name can be
1639 for(i
= 1; i
< s1
->nb_sections
; i
++) {
1640 s
= s1
->sections
[i
];
1641 if (s
->sh_type
== SHT_PROGBITS
&&
1642 (s
->sh_flags
& SHF_ALLOC
)) {
1646 /* check if section name can be expressed in C */
1652 if (!isid(ch
) && !isnum(ch
))
1656 snprintf(buf
, sizeof(buf
), "__start_%s", s
->name
);
1657 add_elf_sym(symtab_section
,
1659 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1661 snprintf(buf
, sizeof(buf
), "__stop_%s", s
->name
);
1662 add_elf_sym(symtab_section
,
1664 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1671 static void tcc_output_binary(TCCState
*s1
, FILE *f
,
1672 const int *sec_order
)
1675 int i
, offset
, size
;
1678 for(i
=1;i
<s1
->nb_sections
;i
++) {
1679 s
= s1
->sections
[sec_order
[i
]];
1680 if (s
->sh_type
!= SHT_NOBITS
&&
1681 (s
->sh_flags
& SHF_ALLOC
)) {
1682 while (offset
< s
->sh_offset
) {
1687 fwrite(s
->data
, 1, size
, f
);
1693 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1695 #define EXTRA_RELITEMS 14
1697 /* move the relocation value from .dynsym to .got */
1698 void patch_dynsym_undef(TCCState
*s1
, Section
*s
)
1700 uint32_t *gotd
= (void *)s1
->got
->data
;
1703 gotd
+= 3; /* dummy entries in .got */
1704 /* relocate symbols in .dynsym */
1705 for_each_elem(s
, 1, sym
, ElfW(Sym
)) {
1706 if (sym
->st_shndx
== SHN_UNDEF
) {
1707 *gotd
++ = sym
->st_value
+ 6; /* XXX 6 is magic ? */
1714 #define EXTRA_RELITEMS 9
1716 /* zero plt offsets of weak symbols in .dynsym */
1717 void patch_dynsym_undef(TCCState
*s1
, Section
*s
)
1721 for_each_elem(s
, 1, sym
, ElfW(Sym
))
1722 if (sym
->st_shndx
== SHN_UNDEF
&& ELFW(ST_BIND
)(sym
->st_info
) == STB_WEAK
)
1727 ST_FUNC
void fill_got_entry(TCCState
*s1
, ElfW_Rel
*rel
)
1729 int sym_index
= ELFW(R_SYM
) (rel
->r_info
);
1730 ElfW(Sym
) *sym
= &((ElfW(Sym
) *) symtab_section
->data
)[sym_index
];
1731 unsigned long offset
;
1733 if (sym_index
>= s1
->nb_sym_attrs
)
1735 offset
= s1
->sym_attrs
[sym_index
].got_offset
;
1736 section_reserve(s1
->got
, offset
+ PTR_SIZE
);
1737 #ifdef TCC_TARGET_X86_64
1738 /* only works for x86-64 */
1739 put32(s1
->got
->data
+ offset
+ 4, sym
->st_value
>> 32);
1741 put32(s1
->got
->data
+ offset
, sym
->st_value
& 0xffffffff);
1744 /* Perform relocation to GOT or PLT entries */
1745 ST_FUNC
void fill_got(TCCState
*s1
)
1751 for(i
= 1; i
< s1
->nb_sections
; i
++) {
1752 s
= s1
->sections
[i
];
1753 if (s
->sh_type
!= SHT_RELX
)
1755 /* no need to handle got relocations */
1756 if (s
->link
!= symtab_section
)
1758 for_each_elem(s
, 0, rel
, ElfW_Rel
) {
1759 switch (ELFW(R_TYPE
) (rel
->r_info
)) {
1760 case R_X86_64_GOT32
:
1761 case R_X86_64_GOTPCREL
:
1762 case R_X86_64_PLT32
:
1763 fill_got_entry(s1
, rel
);
1770 /* Bind symbols of executable: resolve undefined symbols from exported symbols
1771 in shared libraries and export non local defined symbols to shared libraries
1772 if -rdynamic switch was given on command line */
1773 static void bind_exe_dynsyms(TCCState
*s1
)
1776 int sym_index
, index
;
1777 ElfW(Sym
) *sym
, *esym
;
1780 /* Resolve undefined symbols from dynamic symbols. When there is a match:
1781 - if STT_FUNC or STT_GNU_IFUNC symbol -> add it in PLT
1782 - if STT_OBJECT symbol -> add it in .bss section with suitable reloc */
1783 for_each_elem(symtab_section
, 1, sym
, ElfW(Sym
)) {
1784 if (sym
->st_shndx
== SHN_UNDEF
) {
1785 name
= (char *) symtab_section
->link
->data
+ sym
->st_name
;
1786 sym_index
= find_elf_sym(s1
->dynsymtab_section
, name
);
1788 esym
= &((ElfW(Sym
) *)s1
->dynsymtab_section
->data
)[sym_index
];
1789 type
= ELFW(ST_TYPE
)(esym
->st_info
);
1790 if ((type
== STT_FUNC
) || (type
== STT_GNU_IFUNC
)) {
1791 /* Indirect functions shall have STT_FUNC type in executable
1792 * dynsym section. Indeed, a dlsym call following a lazy
1793 * resolution would pick the symbol value from the
1794 * executable dynsym entry which would contain the address
1795 * of the function wanted by the caller of dlsym instead of
1796 * the address of the function that would return that
1798 put_got_entry(s1
, R_JMP_SLOT
, esym
->st_size
,
1799 ELFW(ST_INFO
)(STB_GLOBAL
,STT_FUNC
),
1800 sym
- (ElfW(Sym
) *)symtab_section
->data
);
1801 } else if (type
== STT_OBJECT
) {
1802 unsigned long offset
;
1804 offset
= bss_section
->data_offset
;
1805 /* XXX: which alignment ? */
1806 offset
= (offset
+ 16 - 1) & -16;
1807 index
= put_elf_sym(s1
->dynsym
, offset
, esym
->st_size
,
1808 esym
->st_info
, 0, bss_section
->sh_num
,
1810 /* Ensure R_COPY works for weak symbol aliases */
1811 if (ELFW(ST_BIND
)(esym
->st_info
) == STB_WEAK
) {
1812 for_each_elem(s1
->dynsymtab_section
, 1, dynsym
, ElfW(Sym
)) {
1813 if ((dynsym
->st_value
== esym
->st_value
)
1814 && (ELFW(ST_BIND
)(dynsym
->st_info
) == STB_GLOBAL
)) {
1815 char *dynname
= (char *) s1
->dynsymtab_section
->link
->data
1817 put_elf_sym(s1
->dynsym
, offset
, dynsym
->st_size
,
1819 bss_section
->sh_num
, dynname
);
1824 put_elf_reloc(s1
->dynsym
, bss_section
,
1825 offset
, R_COPY
, index
);
1826 offset
+= esym
->st_size
;
1827 bss_section
->data_offset
= offset
;
1830 /* STB_WEAK undefined symbols are accepted */
1831 /* XXX: _fp_hw seems to be part of the ABI, so we ignore it */
1832 if (ELFW(ST_BIND
)(sym
->st_info
) == STB_WEAK
||
1833 !strcmp(name
, "_fp_hw")) {
1835 tcc_error_noabort("undefined symbol '%s'", name
);
1838 } else if (s1
->rdynamic
&& ELFW(ST_BIND
)(sym
->st_info
) != STB_LOCAL
) {
1839 /* if -rdynamic option, then export all non local symbols */
1840 name
= (char *) symtab_section
->link
->data
+ sym
->st_name
;
1841 put_elf_sym(s1
->dynsym
, sym
->st_value
, sym
->st_size
, sym
->st_info
,
1842 0, sym
->st_shndx
, name
);
1847 /* Bind symbols of libraries: export non local symbols of executable that
1848 resolve undefined symbols of shared libraries */
1849 static void bind_libs_dynsyms(TCCState
*s1
)
1853 ElfW(Sym
) *sym
, *esym
;
1855 /* now look at unresolved dynamic symbols and export
1856 corresponding symbol */
1857 for_each_elem(s1
->dynsymtab_section
, 1, esym
, ElfW(Sym
)) {
1858 if (esym
->st_shndx
== SHN_UNDEF
) {
1859 name
= (char *) s1
->dynsymtab_section
->link
->data
+ esym
->st_name
;
1860 sym_index
= find_elf_sym(symtab_section
, name
);
1862 /* XXX: avoid adding a symbol if already present because of
1864 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
1865 put_elf_sym(s1
->dynsym
, sym
->st_value
, sym
->st_size
,
1866 sym
->st_info
, 0, sym
->st_shndx
, name
);
1868 /* weak symbols can stay undefined */
1869 if (ELFW(ST_BIND
)(esym
->st_info
) != STB_WEAK
)
1870 tcc_warning("undefined dynamic symbol '%s'", name
);
1876 /* Export all non local symbols (for shared libraries) */
1877 static void export_global_syms(TCCState
*s1
)
1879 int nb_syms
, dynindex
, index
;
1883 nb_syms
= symtab_section
->data_offset
/ sizeof(ElfW(Sym
));
1884 s1
->symtab_to_dynsym
= tcc_mallocz(sizeof(int) * nb_syms
);
1885 for_each_elem(symtab_section
, 1, sym
, ElfW(Sym
)) {
1886 if (ELFW(ST_BIND
)(sym
->st_info
) != STB_LOCAL
) {
1887 name
= (char *) symtab_section
->link
->data
+ sym
->st_name
;
1888 dynindex
= put_elf_sym(s1
->dynsym
, sym
->st_value
, sym
->st_size
,
1889 sym
->st_info
, 0, sym
->st_shndx
, name
);
1890 index
= sym
- (ElfW(Sym
) *) symtab_section
->data
;
1891 s1
->symtab_to_dynsym
[index
] = dynindex
;
1896 /* relocate the PLT: compute addresses and offsets in the PLT now that final
1897 address for PLT and GOT are known (see fill_program_header) */
1898 ST_FUNC
void relocate_plt(TCCState
*s1
)
1906 p_end
= p
+ s1
->plt
->data_offset
;
1908 #if defined(TCC_TARGET_I386)
1909 put32(p
+ 2, get32(p
+ 2) + s1
->got
->sh_addr
);
1910 put32(p
+ 8, get32(p
+ 8) + s1
->got
->sh_addr
);
1913 put32(p
+ 2, get32(p
+ 2) + s1
->got
->sh_addr
);
1916 #elif defined(TCC_TARGET_X86_64)
1917 int x
= s1
->got
->sh_addr
- s1
->plt
->sh_addr
- 6;
1918 put32(p
+ 2, get32(p
+ 2) + x
);
1919 put32(p
+ 8, get32(p
+ 8) + x
- 6);
1922 put32(p
+ 2, get32(p
+ 2) + x
+ s1
->plt
->data
- p
);
1925 #elif defined(TCC_TARGET_ARM)
1927 x
=s1
->got
->sh_addr
- s1
->plt
->sh_addr
- 12;
1930 if (get32(p
) == 0x46c04778) /* PLT Thumb stub present */
1932 put32(p
+ 12, x
+ get32(p
+ 12) + s1
->plt
->data
- p
);
1935 #elif defined(TCC_TARGET_ARM64)
1936 uint64_t plt
= s1
->plt
->sh_addr
;
1937 uint64_t got
= s1
->got
->sh_addr
;
1938 uint64_t off
= (got
>> 12) - (plt
>> 12);
1939 if ((off
+ ((uint32_t)1 << 20)) >> 21)
1940 tcc_error("Failed relocating PLT (off=0x%lx, got=0x%lx, plt=0x%lx)", off
, got
, plt
);
1941 put32(p
, 0xa9bf7bf0); // stp x16,x30,[sp,#-16]!
1942 put32(p
+ 4, (0x90000010 | // adrp x16,...
1943 (off
& 0x1ffffc) << 3 | (off
& 3) << 29));
1944 put32(p
+ 8, (0xf9400211 | // ldr x17,[x16,#...]
1945 (got
& 0xff8) << 7));
1946 put32(p
+ 12, (0x91000210 | // add x16,x16,#...
1947 (got
& 0xfff) << 10));
1948 put32(p
+ 16, 0xd61f0220); // br x17
1949 put32(p
+ 20, 0xd503201f); // nop
1950 put32(p
+ 24, 0xd503201f); // nop
1951 put32(p
+ 28, 0xd503201f); // nop
1954 uint64_t pc
= plt
+ (p
- s1
->plt
->data
);
1955 uint64_t addr
= got
+
1956 (get32(p
) | (uint64_t)get32(p
+ 4) << 32);
1957 uint32_t off
= (addr
>> 12) - (pc
>> 12);
1958 if ((off
+ ((uint32_t)1 << 20)) >> 21)
1959 tcc_error("Failed relocating PLT (off=0x%lx, addr=0x%lx, pc=0x%lx)", off
, addr
, pc
);
1960 put32(p
, (0x90000010 | // adrp x16,...
1961 (off
& 0x1ffffc) << 3 | (off
& 3) << 29));
1962 put32(p
+ 4, (0xf9400211 | // ldr x17,[x16,#...]
1963 (addr
& 0xff8) << 7));
1964 put32(p
+ 8, (0x91000210 | // add x16,x16,#...
1965 (addr
& 0xfff) << 10));
1966 put32(p
+ 12, 0xd61f0220); // br x17
1969 #elif defined(TCC_TARGET_C67)
1972 #error unsupported CPU
1977 /* Allocate strings for section names and decide if an unallocated section
1980 NOTE: the strsec section comes last, so its size is also correct ! */
1981 static void alloc_sec_names(TCCState
*s1
, int file_type
, Section
*strsec
)
1986 /* Allocate strings for section names */
1987 for(i
= 1; i
< s1
->nb_sections
; i
++) {
1988 s
= s1
->sections
[i
];
1989 s
->sh_name
= put_elf_str(strsec
, s
->name
);
1990 /* when generating a DLL, we include relocations but we may
1992 if (file_type
== TCC_OUTPUT_DLL
&&
1993 s
->sh_type
== SHT_RELX
&&
1994 !(s
->sh_flags
& SHF_ALLOC
)) {
1995 /* gr: avoid bogus relocs for empty (debug) sections */
1996 if (s1
->sections
[s
->sh_info
]->sh_flags
& SHF_ALLOC
)
1997 prepare_dynamic_rel(s1
, s
);
1998 else if (s1
->do_debug
)
1999 s
->sh_size
= s
->data_offset
;
2000 } else if (s1
->do_debug
||
2001 file_type
== TCC_OUTPUT_OBJ
||
2002 (s
->sh_flags
& SHF_ALLOC
) ||
2003 i
== (s1
->nb_sections
- 1)) {
2004 /* we output all sections if debug or object file */
2005 s
->sh_size
= s
->data_offset
;
2010 /* Info to be copied in dynamic section */
2014 unsigned long dyn_rel_off
;
2017 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2023 /* Assign sections to segments and decide how are sections laid out when loaded
2024 in memory. This function also fills corresponding program headers. */
2025 static int layout_sections(TCCState
*s1
, ElfW(Phdr
) *phdr
, int phnum
,
2026 Section
*interp
, Section
* strsec
,
2027 struct dyn_inf
*dyninf
, int *sec_order
)
2029 int i
, j
, k
, file_type
, sh_order_index
, file_offset
;
2030 unsigned long s_align
;
2036 file_type
= s1
->output_type
;
2039 if (s1
->output_format
== TCC_OUTPUT_FORMAT_ELF
)
2040 file_offset
= sizeof(ElfW(Ehdr
)) + phnum
* sizeof(ElfW(Phdr
));
2041 s_align
= ELF_PAGE_SIZE
;
2042 if (s1
->section_align
)
2043 s_align
= s1
->section_align
;
2046 if (s1
->has_text_addr
) {
2047 int a_offset
, p_offset
;
2048 addr
= s1
->text_addr
;
2049 /* we ensure that (addr % ELF_PAGE_SIZE) == file_offset %
2051 a_offset
= (int) (addr
& (s_align
- 1));
2052 p_offset
= file_offset
& (s_align
- 1);
2053 if (a_offset
< p_offset
)
2054 a_offset
+= s_align
;
2055 file_offset
+= (a_offset
- p_offset
);
2057 if (file_type
== TCC_OUTPUT_DLL
)
2060 addr
= ELF_START_ADDR
;
2061 /* compute address after headers */
2062 addr
+= (file_offset
& (s_align
- 1));
2066 /* Leave one program headers for the program interpreter and one for
2067 the program header table itself if needed. These are done later as
2068 they require section layout to be done first. */
2070 ph
+= 1 + HAVE_PHDR
;
2072 /* dynamic relocation table information, for .dynamic section */
2073 dyninf
->rel_addr
= dyninf
->rel_size
= 0;
2074 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2075 dyninf
->bss_addr
= dyninf
->bss_size
= 0;
2078 for(j
= 0; j
< 2; j
++) {
2079 ph
->p_type
= PT_LOAD
;
2081 ph
->p_flags
= PF_R
| PF_X
;
2083 ph
->p_flags
= PF_R
| PF_W
;
2084 ph
->p_align
= s_align
;
2086 /* Decide the layout of sections loaded in memory. This must
2087 be done before program headers are filled since they contain
2088 info about the layout. We do the following ordering: interp,
2089 symbol tables, relocations, progbits, nobits */
2090 /* XXX: do faster and simpler sorting */
2091 for(k
= 0; k
< 5; k
++) {
2092 for(i
= 1; i
< s1
->nb_sections
; i
++) {
2093 s
= s1
->sections
[i
];
2094 /* compute if section should be included */
2096 if ((s
->sh_flags
& (SHF_ALLOC
| SHF_WRITE
)) !=
2100 if ((s
->sh_flags
& (SHF_ALLOC
| SHF_WRITE
)) !=
2101 (SHF_ALLOC
| SHF_WRITE
))
2107 } else if (s
->sh_type
== SHT_DYNSYM
||
2108 s
->sh_type
== SHT_STRTAB
||
2109 s
->sh_type
== SHT_HASH
) {
2112 } else if (s
->sh_type
== SHT_RELX
) {
2115 } else if (s
->sh_type
== SHT_NOBITS
) {
2122 sec_order
[sh_order_index
++] = i
;
2124 /* section matches: we align it and add its size */
2126 addr
= (addr
+ s
->sh_addralign
- 1) &
2127 ~(s
->sh_addralign
- 1);
2128 file_offset
+= (int) ( addr
- tmp
);
2129 s
->sh_offset
= file_offset
;
2132 /* update program header infos */
2133 if (ph
->p_offset
== 0) {
2134 ph
->p_offset
= file_offset
;
2136 ph
->p_paddr
= ph
->p_vaddr
;
2138 /* update dynamic relocation infos */
2139 if (s
->sh_type
== SHT_RELX
) {
2140 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2141 if (!strcmp(strsec
->data
+ s
->sh_name
, ".rel.got")) {
2142 dyninf
->rel_addr
= addr
;
2143 dyninf
->rel_size
+= s
->sh_size
; /* XXX only first rel. */
2145 if (!strcmp(strsec
->data
+ s
->sh_name
, ".rel.bss")) {
2146 dyninf
->bss_addr
= addr
;
2147 dyninf
->bss_size
= s
->sh_size
; /* XXX only first rel. */
2150 if (dyninf
->rel_size
== 0)
2151 dyninf
->rel_addr
= addr
;
2152 dyninf
->rel_size
+= s
->sh_size
;
2156 if (s
->sh_type
!= SHT_NOBITS
)
2157 file_offset
+= s
->sh_size
;
2161 /* Make the first PT_LOAD segment include the program
2162 headers itself (and the ELF header as well), it'll
2163 come out with same memory use but will make various
2164 tools like binutils strip work better. */
2165 ph
->p_offset
&= ~(ph
->p_align
- 1);
2166 ph
->p_vaddr
&= ~(ph
->p_align
- 1);
2167 ph
->p_paddr
&= ~(ph
->p_align
- 1);
2169 ph
->p_filesz
= file_offset
- ph
->p_offset
;
2170 ph
->p_memsz
= addr
- ph
->p_vaddr
;
2173 if (s1
->output_format
== TCC_OUTPUT_FORMAT_ELF
) {
2174 /* if in the middle of a page, we duplicate the page in
2175 memory so that one copy is RX and the other is RW */
2176 if ((addr
& (s_align
- 1)) != 0)
2179 addr
= (addr
+ s_align
- 1) & ~(s_align
- 1);
2180 file_offset
= (file_offset
+ s_align
- 1) & ~(s_align
- 1);
2186 /* all other sections come after */
2187 for(i
= 1; i
< s1
->nb_sections
; i
++) {
2188 s
= s1
->sections
[i
];
2189 if (phnum
> 0 && (s
->sh_flags
& SHF_ALLOC
))
2191 sec_order
[sh_order_index
++] = i
;
2193 file_offset
= (file_offset
+ s
->sh_addralign
- 1) &
2194 ~(s
->sh_addralign
- 1);
2195 s
->sh_offset
= file_offset
;
2196 if (s
->sh_type
!= SHT_NOBITS
)
2197 file_offset
+= s
->sh_size
;
2203 static void fill_unloadable_phdr(ElfW(Phdr
) *phdr
, int phnum
, Section
*interp
,
2208 /* if interpreter, then add corresponding program header */
2214 int len
= phnum
* sizeof(ElfW(Phdr
));
2216 ph
->p_type
= PT_PHDR
;
2217 ph
->p_offset
= sizeof(ElfW(Ehdr
));
2218 ph
->p_vaddr
= interp
->sh_addr
- len
;
2219 ph
->p_paddr
= ph
->p_vaddr
;
2220 ph
->p_filesz
= ph
->p_memsz
= len
;
2221 ph
->p_flags
= PF_R
| PF_X
;
2222 ph
->p_align
= 4; /* interp->sh_addralign; */
2226 ph
->p_type
= PT_INTERP
;
2227 ph
->p_offset
= interp
->sh_offset
;
2228 ph
->p_vaddr
= interp
->sh_addr
;
2229 ph
->p_paddr
= ph
->p_vaddr
;
2230 ph
->p_filesz
= interp
->sh_size
;
2231 ph
->p_memsz
= interp
->sh_size
;
2233 ph
->p_align
= interp
->sh_addralign
;
2236 /* if dynamic section, then add corresponding program header */
2238 ph
= &phdr
[phnum
- 1];
2240 ph
->p_type
= PT_DYNAMIC
;
2241 ph
->p_offset
= dynamic
->sh_offset
;
2242 ph
->p_vaddr
= dynamic
->sh_addr
;
2243 ph
->p_paddr
= ph
->p_vaddr
;
2244 ph
->p_filesz
= dynamic
->sh_size
;
2245 ph
->p_memsz
= dynamic
->sh_size
;
2246 ph
->p_flags
= PF_R
| PF_W
;
2247 ph
->p_align
= dynamic
->sh_addralign
;
2251 /* Fill the dynamic section with tags describing the address and size of
2253 static void fill_dynamic(TCCState
*s1
, struct dyn_inf
*dyninf
)
2257 dynamic
= dyninf
->dynamic
;
2259 /* put dynamic section entries */
2260 dynamic
->data_offset
= dyninf
->dyn_rel_off
;
2261 put_dt(dynamic
, DT_HASH
, s1
->dynsym
->hash
->sh_addr
);
2262 put_dt(dynamic
, DT_STRTAB
, dyninf
->dynstr
->sh_addr
);
2263 put_dt(dynamic
, DT_SYMTAB
, s1
->dynsym
->sh_addr
);
2264 put_dt(dynamic
, DT_STRSZ
, dyninf
->dynstr
->data_offset
);
2265 put_dt(dynamic
, DT_SYMENT
, sizeof(ElfW(Sym
)));
2266 #if defined(TCC_TARGET_ARM64) || defined(TCC_TARGET_X86_64)
2267 put_dt(dynamic
, DT_RELA
, dyninf
->rel_addr
);
2268 put_dt(dynamic
, DT_RELASZ
, dyninf
->rel_size
);
2269 put_dt(dynamic
, DT_RELAENT
, sizeof(ElfW_Rel
));
2271 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2272 put_dt(dynamic
, DT_PLTGOT
, s1
->got
->sh_addr
);
2273 put_dt(dynamic
, DT_PLTRELSZ
, dyninf
->rel_size
);
2274 put_dt(dynamic
, DT_JMPREL
, dyninf
->rel_addr
);
2275 put_dt(dynamic
, DT_PLTREL
, DT_REL
);
2276 put_dt(dynamic
, DT_REL
, dyninf
->bss_addr
);
2277 put_dt(dynamic
, DT_RELSZ
, dyninf
->bss_size
);
2279 put_dt(dynamic
, DT_REL
, dyninf
->rel_addr
);
2280 put_dt(dynamic
, DT_RELSZ
, dyninf
->rel_size
);
2281 put_dt(dynamic
, DT_RELENT
, sizeof(ElfW_Rel
));
2285 put_dt(dynamic
, DT_DEBUG
, 0);
2286 put_dt(dynamic
, DT_NULL
, 0);
2289 /* Relocate remaining sections and symbols (that is those not related to
2291 static int final_sections_reloc(TCCState
*s1
)
2296 relocate_syms(s1
, 0);
2298 if (s1
->nb_errors
!= 0)
2301 /* relocate sections */
2302 /* XXX: ignore sections with allocated relocations ? */
2303 for(i
= 1; i
< s1
->nb_sections
; i
++) {
2304 s
= s1
->sections
[i
];
2305 if (s
->reloc
&& s
!= s1
->got
&& (s
->sh_flags
& SHF_ALLOC
)) //gr
2306 relocate_section(s1
, s
);
2309 /* relocate relocation entries if the relocation tables are
2310 allocated in the executable */
2311 for(i
= 1; i
< s1
->nb_sections
; i
++) {
2312 s
= s1
->sections
[i
];
2313 if ((s
->sh_flags
& SHF_ALLOC
) &&
2314 s
->sh_type
== SHT_RELX
) {
2315 relocate_rel(s1
, s
);
2321 /* Create an ELF file on disk.
2322 This function handle ELF specific layout requirements */
2323 static void tcc_output_elf(TCCState
*s1
, FILE *f
, int phnum
, ElfW(Phdr
) *phdr
,
2324 int file_offset
, int *sec_order
)
2326 int i
, shnum
, offset
, size
, file_type
;
2329 ElfW(Shdr
) shdr
, *sh
;
2331 file_type
= s1
->output_type
;
2332 shnum
= s1
->nb_sections
;
2334 memset(&ehdr
, 0, sizeof(ehdr
));
2337 ehdr
.e_phentsize
= sizeof(ElfW(Phdr
));
2338 ehdr
.e_phnum
= phnum
;
2339 ehdr
.e_phoff
= sizeof(ElfW(Ehdr
));
2343 file_offset
= (file_offset
+ 3) & -4;
2346 ehdr
.e_ident
[0] = ELFMAG0
;
2347 ehdr
.e_ident
[1] = ELFMAG1
;
2348 ehdr
.e_ident
[2] = ELFMAG2
;
2349 ehdr
.e_ident
[3] = ELFMAG3
;
2350 ehdr
.e_ident
[4] = ELFCLASSW
;
2351 ehdr
.e_ident
[5] = ELFDATA2LSB
;
2352 ehdr
.e_ident
[6] = EV_CURRENT
;
2353 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2354 ehdr
.e_ident
[EI_OSABI
] = ELFOSABI_FREEBSD
;
2356 #ifdef TCC_TARGET_ARM
2358 ehdr
.e_ident
[EI_OSABI
] = 0;
2359 ehdr
.e_flags
= EF_ARM_EABI_VER4
;
2360 if (file_type
== TCC_OUTPUT_EXE
|| file_type
== TCC_OUTPUT_DLL
)
2361 ehdr
.e_flags
|= EF_ARM_HASENTRY
;
2362 if (s1
->float_abi
== ARM_HARD_FLOAT
)
2363 ehdr
.e_flags
|= EF_ARM_VFP_FLOAT
;
2365 ehdr
.e_flags
|= EF_ARM_SOFT_FLOAT
;
2367 ehdr
.e_ident
[EI_OSABI
] = ELFOSABI_ARM
;
2372 case TCC_OUTPUT_EXE
:
2373 ehdr
.e_type
= ET_EXEC
;
2374 ehdr
.e_entry
= get_elf_sym_addr(s1
, "_start", 1);
2376 case TCC_OUTPUT_DLL
:
2377 ehdr
.e_type
= ET_DYN
;
2378 ehdr
.e_entry
= text_section
->sh_addr
; /* XXX: is it correct ? */
2380 case TCC_OUTPUT_OBJ
:
2381 ehdr
.e_type
= ET_REL
;
2384 ehdr
.e_machine
= EM_TCC_TARGET
;
2385 ehdr
.e_version
= EV_CURRENT
;
2386 ehdr
.e_shoff
= file_offset
;
2387 ehdr
.e_ehsize
= sizeof(ElfW(Ehdr
));
2388 ehdr
.e_shentsize
= sizeof(ElfW(Shdr
));
2389 ehdr
.e_shnum
= shnum
;
2390 ehdr
.e_shstrndx
= shnum
- 1;
2392 fwrite(&ehdr
, 1, sizeof(ElfW(Ehdr
)), f
);
2393 fwrite(phdr
, 1, phnum
* sizeof(ElfW(Phdr
)), f
);
2394 offset
= sizeof(ElfW(Ehdr
)) + phnum
* sizeof(ElfW(Phdr
));
2396 sort_syms(s1
, symtab_section
);
2397 for(i
= 1; i
< s1
->nb_sections
; i
++) {
2398 s
= s1
->sections
[sec_order
[i
]];
2399 if (s
->sh_type
!= SHT_NOBITS
) {
2400 if (s
->sh_type
== SHT_DYNSYM
)
2401 patch_dynsym_undef(s1
, s
);
2402 while (offset
< s
->sh_offset
) {
2407 fwrite(s
->data
, 1, size
, f
);
2412 /* output section headers */
2413 while (offset
< ehdr
.e_shoff
) {
2418 for(i
= 0; i
< s1
->nb_sections
; i
++) {
2420 memset(sh
, 0, sizeof(ElfW(Shdr
)));
2421 s
= s1
->sections
[i
];
2423 sh
->sh_name
= s
->sh_name
;
2424 sh
->sh_type
= s
->sh_type
;
2425 sh
->sh_flags
= s
->sh_flags
;
2426 sh
->sh_entsize
= s
->sh_entsize
;
2427 sh
->sh_info
= s
->sh_info
;
2429 sh
->sh_link
= s
->link
->sh_num
;
2430 sh
->sh_addralign
= s
->sh_addralign
;
2431 sh
->sh_addr
= s
->sh_addr
;
2432 sh
->sh_offset
= s
->sh_offset
;
2433 sh
->sh_size
= s
->sh_size
;
2435 fwrite(sh
, 1, sizeof(ElfW(Shdr
)), f
);
2439 /* Write an elf, coff or "binary" file */
2440 static int tcc_write_elf_file(TCCState
*s1
, const char *filename
, int phnum
,
2441 ElfW(Phdr
) *phdr
, int file_offset
, int *sec_order
)
2443 int fd
, mode
, file_type
;
2446 file_type
= s1
->output_type
;
2447 if (file_type
== TCC_OUTPUT_OBJ
)
2452 fd
= open(filename
, O_WRONLY
| O_CREAT
| O_TRUNC
| O_BINARY
, mode
);
2454 tcc_error_noabort("could not write '%s'", filename
);
2457 f
= fdopen(fd
, "wb");
2459 printf("<- %s\n", filename
);
2461 #ifdef TCC_TARGET_COFF
2462 if (s1
->output_format
== TCC_OUTPUT_FORMAT_COFF
)
2463 tcc_output_coff(s1
, f
);
2466 if (s1
->output_format
== TCC_OUTPUT_FORMAT_ELF
)
2467 tcc_output_elf(s1
, f
, phnum
, phdr
, file_offset
, sec_order
);
2469 tcc_output_binary(s1
, f
, sec_order
);
2475 /* Output an elf, coff or binary file */
2476 /* XXX: suppress unneeded sections */
2477 static int elf_output_file(TCCState
*s1
, const char *filename
)
2479 int i
, ret
, phnum
, shnum
, file_type
, file_offset
, *sec_order
;
2480 struct dyn_inf dyninf
;
2483 Section
*strsec
, *interp
, *dynamic
, *dynstr
;
2485 file_type
= s1
->output_type
;
2488 /* if linking, also link in runtime libraries (libc, libgcc, etc.) */
2489 if (file_type
!= TCC_OUTPUT_OBJ
) {
2490 tcc_add_runtime(s1
);
2495 interp
= dynamic
= dynstr
= NULL
; /* avoid warning */
2496 dyninf
.dyn_rel_off
= 0; /* avoid warning */
2498 if (file_type
!= TCC_OUTPUT_OBJ
) {
2499 relocate_common_syms();
2501 tcc_add_linker_symbols(s1
);
2503 if (!s1
->static_link
) {
2504 if (file_type
== TCC_OUTPUT_EXE
) {
2506 /* allow override the dynamic loader */
2507 const char *elfint
= getenv("LD_SO");
2509 elfint
= DEFAULT_ELFINTERP(s1
);
2510 /* add interpreter section only if executable */
2511 interp
= new_section(s1
, ".interp", SHT_PROGBITS
, SHF_ALLOC
);
2512 interp
->sh_addralign
= 1;
2513 ptr
= section_ptr_add(interp
, 1 + strlen(elfint
));
2514 strcpy(ptr
, elfint
);
2517 /* add dynamic symbol table */
2518 s1
->dynsym
= new_symtab(s1
, ".dynsym", SHT_DYNSYM
, SHF_ALLOC
,
2520 ".hash", SHF_ALLOC
);
2521 dynstr
= s1
->dynsym
->link
;
2523 /* add dynamic section */
2524 dynamic
= new_section(s1
, ".dynamic", SHT_DYNAMIC
,
2525 SHF_ALLOC
| SHF_WRITE
);
2526 dynamic
->link
= dynstr
;
2527 dynamic
->sh_entsize
= sizeof(ElfW(Dyn
));
2531 if (file_type
== TCC_OUTPUT_EXE
) {
2532 bind_exe_dynsyms(s1
);
2534 if (s1
->nb_errors
) {
2539 bind_libs_dynsyms(s1
);
2540 } else /* shared library case: simply export all global symbols */
2541 export_global_syms(s1
);
2543 build_got_entries(s1
);
2545 /* add a list of needed dlls */
2546 for(i
= 0; i
< s1
->nb_loaded_dlls
; i
++) {
2547 DLLReference
*dllref
= s1
->loaded_dlls
[i
];
2548 if (dllref
->level
== 0)
2549 put_dt(dynamic
, DT_NEEDED
, put_elf_str(dynstr
, dllref
->name
));
2553 put_dt(dynamic
, DT_RPATH
, put_elf_str(dynstr
, s1
->rpath
));
2555 /* XXX: currently, since we do not handle PIC code, we
2556 must relocate the readonly segments */
2557 if (file_type
== TCC_OUTPUT_DLL
) {
2559 put_dt(dynamic
, DT_SONAME
, put_elf_str(dynstr
, s1
->soname
));
2560 put_dt(dynamic
, DT_TEXTREL
, 0);
2564 put_dt(dynamic
, DT_SYMBOLIC
, 0);
2566 /* add necessary space for other entries */
2567 dyninf
.dyn_rel_off
= dynamic
->data_offset
;
2568 dynamic
->data_offset
+= sizeof(ElfW(Dyn
)) * EXTRA_RELITEMS
;
2570 /* still need to build got entries in case of static link */
2571 build_got_entries(s1
);
2575 /* we add a section for symbols */
2576 strsec
= new_section(s1
, ".shstrtab", SHT_STRTAB
, 0);
2577 put_elf_str(strsec
, "");
2579 /* compute number of sections */
2580 shnum
= s1
->nb_sections
;
2582 /* this array is used to reorder sections in the output file */
2583 sec_order
= tcc_malloc(sizeof(int) * shnum
);
2586 /* compute number of program headers */
2589 case TCC_OUTPUT_OBJ
:
2592 case TCC_OUTPUT_EXE
:
2593 if (!s1
->static_link
)
2594 phnum
= 4 + HAVE_PHDR
;
2598 case TCC_OUTPUT_DLL
:
2603 /* Allocate strings for section names */
2604 alloc_sec_names(s1
, file_type
, strsec
);
2606 /* allocate program segment headers */
2607 phdr
= tcc_mallocz(phnum
* sizeof(ElfW(Phdr
)));
2609 /* compute section to program header mapping */
2610 file_offset
= layout_sections(s1
, phdr
, phnum
, interp
, strsec
, &dyninf
,
2613 /* Fill remaining program header and finalize relocation related to dynamic
2616 fill_unloadable_phdr(phdr
, phnum
, interp
, dynamic
);
2618 dyninf
.dynamic
= dynamic
;
2619 dyninf
.dynstr
= dynstr
;
2621 fill_dynamic(s1
, &dyninf
);
2623 /* put in GOT the dynamic section address and relocate PLT */
2624 put32(s1
->got
->data
, dynamic
->sh_addr
);
2625 if (file_type
== TCC_OUTPUT_EXE
2626 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
2627 || file_type
== TCC_OUTPUT_DLL
2632 /* relocate symbols in .dynsym now that final addresses are known */
2633 for_each_elem(s1
->dynsym
, 1, sym
, ElfW(Sym
)) {
2634 if (sym
->st_shndx
== SHN_UNDEF
) {
2635 /* relocate to PLT if symbol corresponds to a PLT entry,
2636 but not if it's a weak symbol */
2637 if (ELFW(ST_BIND
)(sym
->st_info
) == STB_WEAK
)
2639 else if (sym
->st_value
)
2640 sym
->st_value
+= s1
->plt
->sh_addr
;
2641 } else if (sym
->st_shndx
< SHN_LORESERVE
) {
2642 /* do symbol relocation */
2643 sym
->st_value
+= s1
->sections
[sym
->st_shndx
]->sh_addr
;
2649 /* if building executable or DLL, then relocate each section
2650 except the GOT which is already relocated */
2651 if (file_type
!= TCC_OUTPUT_OBJ
) {
2652 ret
= final_sections_reloc(s1
);
2657 /* Perform relocation to GOT or PLT entries */
2658 if (file_type
== TCC_OUTPUT_EXE
&& s1
->static_link
)
2661 /* Create the ELF file with name 'filename' */
2662 ret
= tcc_write_elf_file(s1
, filename
, phnum
, phdr
, file_offset
, sec_order
);
2664 tcc_free(s1
->symtab_to_dynsym
);
2665 tcc_free(sec_order
);
2667 tcc_free(s1
->sym_attrs
);
2668 s1
->sym_attrs
= NULL
;
2672 LIBTCCAPI
int tcc_output_file(TCCState
*s
, const char *filename
)
2675 #ifdef TCC_TARGET_PE
2676 if (s
->output_type
!= TCC_OUTPUT_OBJ
) {
2677 ret
= pe_output_file(s
, filename
);
2680 ret
= elf_output_file(s
, filename
);
2684 static void *load_data(int fd
, unsigned long file_offset
, unsigned long size
)
2688 data
= tcc_malloc(size
);
2689 lseek(fd
, file_offset
, SEEK_SET
);
2690 read(fd
, data
, size
);
2694 typedef struct SectionMergeInfo
{
2695 Section
*s
; /* corresponding existing section */
2696 unsigned long offset
; /* offset of the new section in the existing section */
2697 uint8_t new_section
; /* true if section 's' was added */
2698 uint8_t link_once
; /* true if link once section */
2701 /* load an object file and merge it with current files */
2702 /* XXX: handle correctly stab (debug) info */
2703 ST_FUNC
int tcc_load_object_file(TCCState
*s1
,
2704 int fd
, unsigned long file_offset
)
2707 ElfW(Shdr
) *shdr
, *sh
;
2708 int size
, i
, j
, offset
, offseti
, nb_syms
, sym_index
, ret
;
2709 unsigned char *strsec
, *strtab
;
2710 int *old_to_new_syms
;
2711 char *sh_name
, *name
;
2712 SectionMergeInfo
*sm_table
, *sm
;
2713 ElfW(Sym
) *sym
, *symtab
;
2720 stab_index
= stabstr_index
= 0;
2722 if (read(fd
, &ehdr
, sizeof(ehdr
)) != sizeof(ehdr
))
2724 if (ehdr
.e_ident
[0] != ELFMAG0
||
2725 ehdr
.e_ident
[1] != ELFMAG1
||
2726 ehdr
.e_ident
[2] != ELFMAG2
||
2727 ehdr
.e_ident
[3] != ELFMAG3
)
2729 /* test if object file */
2730 if (ehdr
.e_type
!= ET_REL
)
2732 /* test CPU specific stuff */
2733 if (ehdr
.e_ident
[5] != ELFDATA2LSB
||
2734 ehdr
.e_machine
!= EM_TCC_TARGET
) {
2736 tcc_error_noabort("invalid object file");
2740 shdr
= load_data(fd
, file_offset
+ ehdr
.e_shoff
,
2741 sizeof(ElfW(Shdr
)) * ehdr
.e_shnum
);
2742 sm_table
= tcc_mallocz(sizeof(SectionMergeInfo
) * ehdr
.e_shnum
);
2744 /* load section names */
2745 sh
= &shdr
[ehdr
.e_shstrndx
];
2746 strsec
= load_data(fd
, file_offset
+ sh
->sh_offset
, sh
->sh_size
);
2748 /* load symtab and strtab */
2749 old_to_new_syms
= NULL
;
2753 for(i
= 1; i
< ehdr
.e_shnum
; i
++) {
2755 if (sh
->sh_type
== SHT_SYMTAB
) {
2757 tcc_error_noabort("object must contain only one symtab");
2762 nb_syms
= sh
->sh_size
/ sizeof(ElfW(Sym
));
2763 symtab
= load_data(fd
, file_offset
+ sh
->sh_offset
, sh
->sh_size
);
2764 sm_table
[i
].s
= symtab_section
;
2766 /* now load strtab */
2767 sh
= &shdr
[sh
->sh_link
];
2768 strtab
= load_data(fd
, file_offset
+ sh
->sh_offset
, sh
->sh_size
);
2772 /* now examine each section and try to merge its content with the
2774 for(i
= 1; i
< ehdr
.e_shnum
; i
++) {
2775 /* no need to examine section name strtab */
2776 if (i
== ehdr
.e_shstrndx
)
2779 sh_name
= (char *) strsec
+ sh
->sh_name
;
2780 /* ignore sections types we do not handle */
2781 if (sh
->sh_type
!= SHT_PROGBITS
&&
2782 sh
->sh_type
!= SHT_RELX
&&
2784 sh
->sh_type
!= SHT_ARM_EXIDX
&&
2786 sh
->sh_type
!= SHT_NOBITS
&&
2787 sh
->sh_type
!= SHT_PREINIT_ARRAY
&&
2788 sh
->sh_type
!= SHT_INIT_ARRAY
&&
2789 sh
->sh_type
!= SHT_FINI_ARRAY
&&
2790 strcmp(sh_name
, ".stabstr")
2793 if (sh
->sh_addralign
< 1)
2794 sh
->sh_addralign
= 1;
2795 /* find corresponding section, if any */
2796 for(j
= 1; j
< s1
->nb_sections
;j
++) {
2797 s
= s1
->sections
[j
];
2798 if (!strcmp(s
->name
, sh_name
)) {
2799 if (!strncmp(sh_name
, ".gnu.linkonce",
2800 sizeof(".gnu.linkonce") - 1)) {
2801 /* if a 'linkonce' section is already present, we
2802 do not add it again. It is a little tricky as
2803 symbols can still be defined in
2805 sm_table
[i
].link_once
= 1;
2812 /* not found: create new section */
2813 s
= new_section(s1
, sh_name
, sh
->sh_type
, sh
->sh_flags
);
2814 /* take as much info as possible from the section. sh_link and
2815 sh_info will be updated later */
2816 s
->sh_addralign
= sh
->sh_addralign
;
2817 s
->sh_entsize
= sh
->sh_entsize
;
2818 sm_table
[i
].new_section
= 1;
2820 if (sh
->sh_type
!= s
->sh_type
) {
2821 tcc_error_noabort("invalid section type");
2825 /* align start of section */
2826 offset
= s
->data_offset
;
2828 if (0 == strcmp(sh_name
, ".stab")) {
2832 if (0 == strcmp(sh_name
, ".stabstr")) {
2837 size
= sh
->sh_addralign
- 1;
2838 offset
= (offset
+ size
) & ~size
;
2839 if (sh
->sh_addralign
> s
->sh_addralign
)
2840 s
->sh_addralign
= sh
->sh_addralign
;
2841 s
->data_offset
= offset
;
2843 sm_table
[i
].offset
= offset
;
2845 /* concatenate sections */
2847 if (sh
->sh_type
!= SHT_NOBITS
) {
2849 lseek(fd
, file_offset
+ sh
->sh_offset
, SEEK_SET
);
2850 ptr
= section_ptr_add(s
, size
);
2851 read(fd
, ptr
, size
);
2853 s
->data_offset
+= size
;
2858 /* gr relocate stab strings */
2859 if (stab_index
&& stabstr_index
) {
2862 s
= sm_table
[stab_index
].s
;
2863 a
= (Stab_Sym
*)(s
->data
+ sm_table
[stab_index
].offset
);
2864 b
= (Stab_Sym
*)(s
->data
+ s
->data_offset
);
2865 o
= sm_table
[stabstr_index
].offset
;
2867 a
->n_strx
+= o
, a
++;
2870 /* second short pass to update sh_link and sh_info fields of new
2872 for(i
= 1; i
< ehdr
.e_shnum
; i
++) {
2874 if (!s
|| !sm_table
[i
].new_section
)
2877 if (sh
->sh_link
> 0)
2878 s
->link
= sm_table
[sh
->sh_link
].s
;
2879 if (sh
->sh_type
== SHT_RELX
) {
2880 s
->sh_info
= sm_table
[sh
->sh_info
].s
->sh_num
;
2881 /* update backward link */
2882 s1
->sections
[s
->sh_info
]->reloc
= s
;
2887 /* resolve symbols */
2888 old_to_new_syms
= tcc_mallocz(nb_syms
* sizeof(int));
2891 for(i
= 1; i
< nb_syms
; i
++, sym
++) {
2892 if (sym
->st_shndx
!= SHN_UNDEF
&&
2893 sym
->st_shndx
< SHN_LORESERVE
) {
2894 sm
= &sm_table
[sym
->st_shndx
];
2895 if (sm
->link_once
) {
2896 /* if a symbol is in a link once section, we use the
2897 already defined symbol. It is very important to get
2898 correct relocations */
2899 if (ELFW(ST_BIND
)(sym
->st_info
) != STB_LOCAL
) {
2900 name
= (char *) strtab
+ sym
->st_name
;
2901 sym_index
= find_elf_sym(symtab_section
, name
);
2903 old_to_new_syms
[i
] = sym_index
;
2907 /* if no corresponding section added, no need to add symbol */
2910 /* convert section number */
2911 sym
->st_shndx
= sm
->s
->sh_num
;
2913 sym
->st_value
+= sm
->offset
;
2916 name
= (char *) strtab
+ sym
->st_name
;
2917 sym_index
= add_elf_sym(symtab_section
, sym
->st_value
, sym
->st_size
,
2918 sym
->st_info
, sym
->st_other
,
2919 sym
->st_shndx
, name
);
2920 old_to_new_syms
[i
] = sym_index
;
2923 /* third pass to patch relocation entries */
2924 for(i
= 1; i
< ehdr
.e_shnum
; i
++) {
2929 offset
= sm_table
[i
].offset
;
2930 switch(s
->sh_type
) {
2932 /* take relocation offset information */
2933 offseti
= sm_table
[sh
->sh_info
].offset
;
2934 for_each_elem(s
, (offset
/ sizeof(*rel
)), rel
, ElfW_Rel
) {
2937 /* convert symbol index */
2938 type
= ELFW(R_TYPE
)(rel
->r_info
);
2939 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
2940 /* NOTE: only one symtab assumed */
2941 if (sym_index
>= nb_syms
)
2943 sym_index
= old_to_new_syms
[sym_index
];
2944 /* ignore link_once in rel section. */
2945 if (!sym_index
&& !sm
->link_once
2946 #ifdef TCC_TARGET_ARM
2947 && type
!= R_ARM_V4BX
2951 tcc_error_noabort("Invalid relocation entry [%2d] '%s' @ %.8x",
2952 i
, strsec
+ sh
->sh_name
, rel
->r_offset
);
2955 rel
->r_info
= ELFW(R_INFO
)(sym_index
, type
);
2956 /* offset the relocation offset */
2957 rel
->r_offset
+= offseti
;
2958 #ifdef TCC_TARGET_ARM
2959 /* Jumps and branches from a Thumb code to a PLT entry need
2960 special handling since PLT entries are ARM code.
2961 Unconditional bl instructions referencing PLT entries are
2962 handled by converting these instructions into blx
2963 instructions. Other case of instructions referencing a PLT
2964 entry require to add a Thumb stub before the PLT entry to
2965 switch to ARM mode. We set bit plt_thumb_stub of the
2966 attribute of a symbol to indicate such a case. */
2967 if (type
== R_ARM_THM_JUMP24
)
2968 alloc_sym_attr(s1
, sym_index
)->plt_thumb_stub
= 1;
2981 tcc_free(old_to_new_syms
);
2988 typedef struct ArchiveHeader
{
2989 char ar_name
[16]; /* name of this member */
2990 char ar_date
[12]; /* file mtime */
2991 char ar_uid
[6]; /* owner uid; printed as decimal */
2992 char ar_gid
[6]; /* owner gid; printed as decimal */
2993 char ar_mode
[8]; /* file mode, printed as octal */
2994 char ar_size
[10]; /* file size, printed as decimal */
2995 char ar_fmag
[2]; /* should contain ARFMAG */
2998 static int get_be32(const uint8_t *b
)
3000 return b
[3] | (b
[2] << 8) | (b
[1] << 16) | (b
[0] << 24);
3003 /* load only the objects which resolve undefined symbols */
3004 static int tcc_load_alacarte(TCCState
*s1
, int fd
, int size
)
3006 int i
, bound
, nsyms
, sym_index
, off
, ret
;
3008 const char *ar_names
, *p
;
3009 const uint8_t *ar_index
;
3012 data
= tcc_malloc(size
);
3013 if (read(fd
, data
, size
) != size
)
3015 nsyms
= get_be32(data
);
3016 ar_index
= data
+ 4;
3017 ar_names
= (char *) ar_index
+ nsyms
* 4;
3021 for(p
= ar_names
, i
= 0; i
< nsyms
; i
++, p
+= strlen(p
)+1) {
3022 sym_index
= find_elf_sym(symtab_section
, p
);
3024 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
3025 if(sym
->st_shndx
== SHN_UNDEF
) {
3026 off
= get_be32(ar_index
+ i
* 4) + sizeof(ArchiveHeader
);
3028 lseek(fd
, off
, SEEK_SET
);
3029 if(tcc_load_object_file(s1
, fd
, off
) < 0) {
3044 /* load a '.a' file */
3045 ST_FUNC
int tcc_load_archive(TCCState
*s1
, int fd
)
3052 unsigned long file_offset
;
3054 /* skip magic which was already checked */
3055 read(fd
, magic
, sizeof(magic
));
3058 len
= read(fd
, &hdr
, sizeof(hdr
));
3061 if (len
!= sizeof(hdr
)) {
3062 tcc_error_noabort("invalid archive");
3065 memcpy(ar_size
, hdr
.ar_size
, sizeof(hdr
.ar_size
));
3066 ar_size
[sizeof(hdr
.ar_size
)] = '\0';
3067 size
= strtol(ar_size
, NULL
, 0);
3068 memcpy(ar_name
, hdr
.ar_name
, sizeof(hdr
.ar_name
));
3069 for(i
= sizeof(hdr
.ar_name
) - 1; i
>= 0; i
--) {
3070 if (ar_name
[i
] != ' ')
3073 ar_name
[i
+ 1] = '\0';
3074 file_offset
= lseek(fd
, 0, SEEK_CUR
);
3076 size
= (size
+ 1) & ~1;
3077 if (!strcmp(ar_name
, "/")) {
3078 /* coff symbol table : we handle it */
3079 if(s1
->alacarte_link
)
3080 return tcc_load_alacarte(s1
, fd
, size
);
3081 } else if (!strcmp(ar_name
, "//") ||
3082 !strcmp(ar_name
, "__.SYMDEF") ||
3083 !strcmp(ar_name
, "__.SYMDEF/") ||
3084 !strcmp(ar_name
, "ARFILENAMES/")) {
3085 /* skip symbol table or archive names */
3087 if (tcc_load_object_file(s1
, fd
, file_offset
) < 0)
3090 lseek(fd
, file_offset
+ size
, SEEK_SET
);
3095 #ifndef TCC_TARGET_PE
3096 /* load a DLL and all referenced DLLs. 'level = 0' means that the DLL
3097 is referenced by the user (so it should be added as DT_NEEDED in
3098 the generated ELF file) */
3099 ST_FUNC
int tcc_load_dll(TCCState
*s1
, int fd
, const char *filename
, int level
)
3102 ElfW(Shdr
) *shdr
, *sh
, *sh1
;
3103 int i
, j
, nb_syms
, nb_dts
, sym_bind
, ret
;
3104 ElfW(Sym
) *sym
, *dynsym
;
3105 ElfW(Dyn
) *dt
, *dynamic
;
3106 unsigned char *dynstr
;
3107 const char *name
, *soname
;
3108 DLLReference
*dllref
;
3110 read(fd
, &ehdr
, sizeof(ehdr
));
3112 /* test CPU specific stuff */
3113 if (ehdr
.e_ident
[5] != ELFDATA2LSB
||
3114 ehdr
.e_machine
!= EM_TCC_TARGET
) {
3115 tcc_error_noabort("bad architecture");
3120 shdr
= load_data(fd
, ehdr
.e_shoff
, sizeof(ElfW(Shdr
)) * ehdr
.e_shnum
);
3122 /* load dynamic section and dynamic symbols */
3126 dynsym
= NULL
; /* avoid warning */
3127 dynstr
= NULL
; /* avoid warning */
3128 for(i
= 0, sh
= shdr
; i
< ehdr
.e_shnum
; i
++, sh
++) {
3129 switch(sh
->sh_type
) {
3131 nb_dts
= sh
->sh_size
/ sizeof(ElfW(Dyn
));
3132 dynamic
= load_data(fd
, sh
->sh_offset
, sh
->sh_size
);
3135 nb_syms
= sh
->sh_size
/ sizeof(ElfW(Sym
));
3136 dynsym
= load_data(fd
, sh
->sh_offset
, sh
->sh_size
);
3137 sh1
= &shdr
[sh
->sh_link
];
3138 dynstr
= load_data(fd
, sh1
->sh_offset
, sh1
->sh_size
);
3145 /* compute the real library name */
3146 soname
= tcc_basename(filename
);
3148 for(i
= 0, dt
= dynamic
; i
< nb_dts
; i
++, dt
++) {
3149 if (dt
->d_tag
== DT_SONAME
) {
3150 soname
= (char *) dynstr
+ dt
->d_un
.d_val
;
3154 /* if the dll is already loaded, do not load it */
3155 for(i
= 0; i
< s1
->nb_loaded_dlls
; i
++) {
3156 dllref
= s1
->loaded_dlls
[i
];
3157 if (!strcmp(soname
, dllref
->name
)) {
3158 /* but update level if needed */
3159 if (level
< dllref
->level
)
3160 dllref
->level
= level
;
3166 /* add the dll and its level */
3167 dllref
= tcc_mallocz(sizeof(DLLReference
) + strlen(soname
));
3168 dllref
->level
= level
;
3169 strcpy(dllref
->name
, soname
);
3170 dynarray_add((void ***)&s1
->loaded_dlls
, &s1
->nb_loaded_dlls
, dllref
);
3172 /* add dynamic symbols in dynsym_section */
3173 for(i
= 1, sym
= dynsym
+ 1; i
< nb_syms
; i
++, sym
++) {
3174 sym_bind
= ELFW(ST_BIND
)(sym
->st_info
);
3175 if (sym_bind
== STB_LOCAL
)
3177 name
= (char *) dynstr
+ sym
->st_name
;
3178 add_elf_sym(s1
->dynsymtab_section
, sym
->st_value
, sym
->st_size
,
3179 sym
->st_info
, sym
->st_other
, sym
->st_shndx
, name
);
3182 /* load all referenced DLLs */
3183 for(i
= 0, dt
= dynamic
; i
< nb_dts
; i
++, dt
++) {
3186 name
= (char *) dynstr
+ dt
->d_un
.d_val
;
3187 for(j
= 0; j
< s1
->nb_loaded_dlls
; j
++) {
3188 dllref
= s1
->loaded_dlls
[j
];
3189 if (!strcmp(name
, dllref
->name
))
3190 goto already_loaded
;
3192 if (tcc_add_dll(s1
, name
, AFF_REFERENCED_DLL
) < 0) {
3193 tcc_error_noabort("referenced dll '%s' not found", name
);
3210 #define LD_TOK_NAME 256
3211 #define LD_TOK_EOF (-1)
3213 /* return next ld script token */
3214 static int ld_next(TCCState
*s1
, char *name
, int name_size
)
3232 file
->buf_ptr
= parse_comment(file
->buf_ptr
);
3233 ch
= file
->buf_ptr
[0];
3241 /* case 'a' ... 'z': */
3268 /* case 'A' ... 'z': */
3303 if (!((ch
>= 'a' && ch
<= 'z') ||
3304 (ch
>= 'A' && ch
<= 'Z') ||
3305 (ch
>= '0' && ch
<= '9') ||
3306 strchr("/.-_+=$:\\,~", ch
)))
3308 if ((q
- name
) < name_size
- 1) {
3327 static int ld_add_file(TCCState
*s1
, const char filename
[])
3331 ret
= tcc_add_file_internal(s1
, filename
, 0);
3333 ret
= tcc_add_dll(s1
, filename
, 0);
3337 static inline int new_undef_syms(void)
3340 ret
= new_undef_sym
;
3345 static int ld_add_file_list(TCCState
*s1
, const char *cmd
, int as_needed
)
3347 char filename
[1024], libname
[1024];
3348 int t
, group
, nblibs
= 0, ret
= 0;
3351 group
= !strcmp(cmd
, "GROUP");
3354 t
= ld_next(s1
, filename
, sizeof(filename
));
3357 t
= ld_next(s1
, filename
, sizeof(filename
));
3360 if (t
== LD_TOK_EOF
) {
3361 tcc_error_noabort("unexpected end of file");
3363 goto lib_parse_error
;
3364 } else if (t
== ')') {
3366 } else if (t
== '-') {
3367 t
= ld_next(s1
, filename
, sizeof(filename
));
3368 if ((t
!= LD_TOK_NAME
) || (filename
[0] != 'l')) {
3369 tcc_error_noabort("library name expected");
3371 goto lib_parse_error
;
3373 pstrcpy(libname
, sizeof libname
, &filename
[1]);
3374 if (s1
->static_link
) {
3375 snprintf(filename
, sizeof filename
, "lib%s.a", libname
);
3377 snprintf(filename
, sizeof filename
, "lib%s.so", libname
);
3379 } else if (t
!= LD_TOK_NAME
) {
3380 tcc_error_noabort("filename expected");
3382 goto lib_parse_error
;
3384 if (!strcmp(filename
, "AS_NEEDED")) {
3385 ret
= ld_add_file_list(s1
, cmd
, 1);
3387 goto lib_parse_error
;
3389 /* TODO: Implement AS_NEEDED support. Ignore it for now */
3391 ret
= ld_add_file(s1
, filename
);
3393 goto lib_parse_error
;
3395 /* Add the filename *and* the libname to avoid future conversions */
3396 dynarray_add((void ***) &libs
, &nblibs
, tcc_strdup(filename
));
3397 if (libname
[0] != '\0')
3398 dynarray_add((void ***) &libs
, &nblibs
, tcc_strdup(libname
));
3402 t
= ld_next(s1
, filename
, sizeof(filename
));
3404 t
= ld_next(s1
, filename
, sizeof(filename
));
3407 if (group
&& !as_needed
) {
3408 while (new_undef_syms()) {
3411 for (i
= 0; i
< nblibs
; i
++)
3412 ld_add_file(s1
, libs
[i
]);
3416 dynarray_reset(&libs
, &nblibs
);
3420 /* interpret a subset of GNU ldscripts to handle the dummy libc.so
3422 ST_FUNC
int tcc_load_ldscript(TCCState
*s1
)
3425 char filename
[1024];
3428 ch
= file
->buf_ptr
[0];
3431 t
= ld_next(s1
, cmd
, sizeof(cmd
));
3432 if (t
== LD_TOK_EOF
)
3434 else if (t
!= LD_TOK_NAME
)
3436 if (!strcmp(cmd
, "INPUT") ||
3437 !strcmp(cmd
, "GROUP")) {
3438 ret
= ld_add_file_list(s1
, cmd
, 0);
3441 } else if (!strcmp(cmd
, "OUTPUT_FORMAT") ||
3442 !strcmp(cmd
, "TARGET")) {
3443 /* ignore some commands */
3444 t
= ld_next(s1
, cmd
, sizeof(cmd
));
3448 t
= ld_next(s1
, filename
, sizeof(filename
));
3449 if (t
== LD_TOK_EOF
) {
3450 tcc_error_noabort("unexpected end of file");
3452 } else if (t
== ')') {
3462 #endif /* !TCC_TARGET_PE */