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 /********************************************************/
27 /* global variables */
29 ST_DATA Section
*text_section
, *data_section
, *bss_section
; /* predefined sections */
30 ST_DATA Section
*common_section
;
31 ST_DATA Section
*cur_text_section
; /* current section where function code is generated */
33 ST_DATA Section
*last_text_section
; /* to handle .previous asm directive */
35 #ifdef CONFIG_TCC_BCHECK
36 /* bound check related sections */
37 ST_DATA Section
*bounds_section
; /* contains global data bound description */
38 ST_DATA Section
*lbounds_section
; /* contains local data bound description */
41 ST_DATA Section
*symtab_section
;
43 ST_DATA Section
*stab_section
, *stabstr_section
;
45 /* XXX: avoid static variable */
46 static int new_undef_sym
= 0; /* Is there a new undefined sym since last new_undef_sym() */
48 /* special flag to indicate that the section should not be linked to the other ones */
49 #define SHF_PRIVATE 0x80000000
50 /* section is dynsymtab_section */
51 #define SHF_DYNSYM 0x40000000
53 /* ------------------------------------------------------------------------- */
55 ST_FUNC
void tccelf_new(TCCState
*s
)
58 dynarray_add(&s
->sections
, &s
->nb_sections
, NULL
);
60 /* create standard sections */
61 text_section
= new_section(s
, ".text", SHT_PROGBITS
, SHF_ALLOC
| SHF_EXECINSTR
);
62 data_section
= new_section(s
, ".data", SHT_PROGBITS
, SHF_ALLOC
| SHF_WRITE
);
63 bss_section
= new_section(s
, ".bss", SHT_NOBITS
, SHF_ALLOC
| SHF_WRITE
);
64 common_section
= new_section(s
, ".common", SHT_NOBITS
, SHF_PRIVATE
);
65 common_section
->sh_num
= SHN_COMMON
;
67 /* symbols are always generated for linking stage */
68 symtab_section
= new_symtab(s
, ".symtab", SHT_SYMTAB
, 0,
70 ".hashtab", SHF_PRIVATE
);
71 s
->symtab
= symtab_section
;
73 /* private symbol table for dynamic symbols */
74 s
->dynsymtab_section
= new_symtab(s
, ".dynsymtab", SHT_SYMTAB
, SHF_PRIVATE
|SHF_DYNSYM
,
76 ".dynhashtab", SHF_PRIVATE
);
77 get_sym_attr(s
, 0, 1);
80 #ifdef CONFIG_TCC_BCHECK
81 ST_FUNC
void tccelf_bounds_new(TCCState
*s
)
83 /* create bounds sections */
84 bounds_section
= new_section(s
, ".bounds",
85 SHT_PROGBITS
, SHF_ALLOC
);
86 lbounds_section
= new_section(s
, ".lbounds",
87 SHT_PROGBITS
, SHF_ALLOC
);
91 ST_FUNC
void tccelf_stab_new(TCCState
*s
)
93 stab_section
= new_section(s
, ".stab", SHT_PROGBITS
, 0);
94 stab_section
->sh_entsize
= sizeof(Stab_Sym
);
95 stabstr_section
= new_section(s
, ".stabstr", SHT_STRTAB
, 0);
96 put_elf_str(stabstr_section
, "");
97 stab_section
->link
= stabstr_section
;
99 put_stabs("", 0, 0, 0, 0);
102 static void free_section(Section
*s
)
107 ST_FUNC
void tccelf_delete(TCCState
*s1
)
111 /* free all sections */
112 for(i
= 1; i
< s1
->nb_sections
; i
++)
113 free_section(s1
->sections
[i
]);
114 dynarray_reset(&s1
->sections
, &s1
->nb_sections
);
116 for(i
= 0; i
< s1
->nb_priv_sections
; i
++)
117 free_section(s1
->priv_sections
[i
]);
118 dynarray_reset(&s1
->priv_sections
, &s1
->nb_priv_sections
);
120 /* free any loaded DLLs */
122 for ( i
= 0; i
< s1
->nb_loaded_dlls
; i
++) {
123 DLLReference
*ref
= s1
->loaded_dlls
[i
];
126 FreeLibrary((HMODULE
)ref
->handle
);
128 dlclose(ref
->handle
);
132 /* free loaded dlls array */
133 dynarray_reset(&s1
->loaded_dlls
, &s1
->nb_loaded_dlls
);
134 tcc_free(s1
->sym_attrs
);
136 symtab_section
= NULL
; /* for tccrun.c:rt_printline() */
139 /* save section data state */
140 ST_FUNC
void tccelf_begin_file(TCCState
*s1
)
143 for (i
= 1; i
< s1
->nb_sections
; i
++) {
145 s
->sh_offset
= s
->data_offset
;
147 /* disable symbol hashing during compilation */
148 s
= s1
->symtab
, s
->reloc
= s
->hash
, s
->hash
= NULL
;
149 #if defined TCC_TARGET_X86_64 && defined TCC_TARGET_PE
154 /* At the end of compilation, convert any UNDEF syms to global, and merge
155 with previously existing symbols */
156 ST_FUNC
void tccelf_end_file(TCCState
*s1
)
158 Section
*s
= s1
->symtab
;
159 int first_sym
, nb_syms
, *tr
, i
;
161 first_sym
= s
->sh_offset
/ sizeof (ElfSym
);
162 nb_syms
= s
->data_offset
/ sizeof (ElfSym
) - first_sym
;
163 s
->data_offset
= s
->sh_offset
;
164 s
->link
->data_offset
= s
->link
->sh_offset
;
165 s
->hash
= s
->reloc
, s
->reloc
= NULL
;
166 tr
= tcc_mallocz(nb_syms
* sizeof *tr
);
168 for (i
= 0; i
< nb_syms
; ++i
) {
169 ElfSym
*sym
= (ElfSym
*)s
->data
+ first_sym
+ i
;
170 if (sym
->st_shndx
== SHN_UNDEF
171 && ELFW(ST_BIND
)(sym
->st_info
) == STB_LOCAL
)
172 sym
->st_info
= ELFW(ST_INFO
)(STB_GLOBAL
, ELFW(ST_TYPE
)(sym
->st_info
));
173 tr
[i
] = set_elf_sym(s
, sym
->st_value
, sym
->st_size
, sym
->st_info
,
174 sym
->st_other
, sym
->st_shndx
, s
->link
->data
+ sym
->st_name
);
176 /* now update relocations */
177 for (i
= 1; i
< s1
->nb_sections
; i
++) {
178 Section
*sr
= s1
->sections
[i
];
179 if (sr
->sh_type
== SHT_RELX
&& sr
->link
== s
) {
180 ElfW_Rel
*rel
= (ElfW_Rel
*)(sr
->data
+ sr
->sh_offset
);
181 ElfW_Rel
*rel_end
= (ElfW_Rel
*)(sr
->data
+ sr
->data_offset
);
182 for (; rel
< rel_end
; ++rel
) {
183 int n
= ELFW(R_SYM
)(rel
->r_info
) - first_sym
;
184 //if (n < 0) tcc_error("internal: invalid symbol index in relocation");
185 rel
->r_info
= ELFW(R_INFO
)(tr
[n
], ELFW(R_TYPE
)(rel
->r_info
));
192 ST_FUNC Section
*new_section(TCCState
*s1
, const char *name
, int sh_type
, int sh_flags
)
196 sec
= tcc_mallocz(sizeof(Section
) + strlen(name
));
197 strcpy(sec
->name
, name
);
198 sec
->sh_type
= sh_type
;
199 sec
->sh_flags
= sh_flags
;
207 sec
->sh_addralign
= 4;
210 sec
->sh_addralign
= 1;
213 sec
->sh_addralign
= PTR_SIZE
; /* gcc/pcc default alignment */
217 if (sh_flags
& SHF_PRIVATE
) {
218 dynarray_add(&s1
->priv_sections
, &s1
->nb_priv_sections
, sec
);
220 sec
->sh_num
= s1
->nb_sections
;
221 dynarray_add(&s1
->sections
, &s1
->nb_sections
, sec
);
227 ST_FUNC Section
*new_symtab(TCCState
*s1
,
228 const char *symtab_name
, int sh_type
, int sh_flags
,
229 const char *strtab_name
,
230 const char *hash_name
, int hash_sh_flags
)
232 Section
*symtab
, *strtab
, *hash
;
233 int *ptr
, nb_buckets
;
235 symtab
= new_section(s1
, symtab_name
, sh_type
, sh_flags
);
236 symtab
->sh_entsize
= sizeof(ElfW(Sym
));
237 strtab
= new_section(s1
, strtab_name
, SHT_STRTAB
, sh_flags
);
238 put_elf_str(strtab
, "");
239 symtab
->link
= strtab
;
240 put_elf_sym(symtab
, 0, 0, 0, 0, 0, NULL
);
244 hash
= new_section(s1
, hash_name
, SHT_HASH
, hash_sh_flags
);
245 hash
->sh_entsize
= sizeof(int);
249 ptr
= section_ptr_add(hash
, (2 + nb_buckets
+ 1) * sizeof(int));
252 memset(ptr
+ 2, 0, (nb_buckets
+ 1) * sizeof(int));
256 /* realloc section and set its content to zero */
257 ST_FUNC
void section_realloc(Section
*sec
, unsigned long new_size
)
262 size
= sec
->data_allocated
;
265 while (size
< new_size
)
267 data
= tcc_realloc(sec
->data
, size
);
268 memset(data
+ sec
->data_allocated
, 0, size
- sec
->data_allocated
);
270 sec
->data_allocated
= size
;
273 /* reserve at least 'size' bytes aligned per 'align' in section
274 'sec' from current offset, and return the aligned offset */
275 ST_FUNC
size_t section_add(Section
*sec
, addr_t size
, int align
)
277 size_t offset
, offset1
;
279 offset
= (sec
->data_offset
+ align
- 1) & -align
;
280 offset1
= offset
+ size
;
281 if (sec
->sh_type
!= SHT_NOBITS
&& offset1
> sec
->data_allocated
)
282 section_realloc(sec
, offset1
);
283 sec
->data_offset
= offset1
;
284 if (align
> sec
->sh_addralign
)
285 sec
->sh_addralign
= align
;
289 /* reserve at least 'size' bytes in section 'sec' from
291 ST_FUNC
void *section_ptr_add(Section
*sec
, addr_t size
)
293 size_t offset
= section_add(sec
, size
, 1);
294 return sec
->data
+ offset
;
297 /* reserve at least 'size' bytes from section start */
298 ST_FUNC
void section_reserve(Section
*sec
, unsigned long size
)
300 if (size
> sec
->data_allocated
)
301 section_realloc(sec
, size
);
302 if (size
> sec
->data_offset
)
303 sec
->data_offset
= size
;
306 /* return a reference to a section, and create it if it does not
308 ST_FUNC Section
*find_section(TCCState
*s1
, const char *name
)
312 for(i
= 1; i
< s1
->nb_sections
; i
++) {
313 sec
= s1
->sections
[i
];
314 if (!strcmp(name
, sec
->name
))
317 /* sections are created as PROGBITS */
318 return new_section(s1
, name
, SHT_PROGBITS
, SHF_ALLOC
);
321 /* ------------------------------------------------------------------------- */
323 ST_FUNC
int put_elf_str(Section
*s
, const char *sym
)
328 len
= strlen(sym
) + 1;
329 offset
= s
->data_offset
;
330 ptr
= section_ptr_add(s
, len
);
331 memmove(ptr
, sym
, len
);
335 /* elf symbol hashing function */
336 static unsigned long elf_hash(const unsigned char *name
)
338 unsigned long h
= 0, g
;
341 h
= (h
<< 4) + *name
++;
350 /* rebuild hash table of section s */
351 /* NOTE: we do factorize the hash table code to go faster */
352 static void rebuild_hash(Section
*s
, unsigned int nb_buckets
)
355 int *ptr
, *hash
, nb_syms
, sym_index
, h
;
356 unsigned char *strtab
;
358 strtab
= s
->link
->data
;
359 nb_syms
= s
->data_offset
/ sizeof(ElfW(Sym
));
362 nb_buckets
= ((int*)s
->hash
->data
)[0];
364 s
->hash
->data_offset
= 0;
365 ptr
= section_ptr_add(s
->hash
, (2 + nb_buckets
+ nb_syms
) * sizeof(int));
370 memset(hash
, 0, (nb_buckets
+ 1) * sizeof(int));
371 ptr
+= nb_buckets
+ 1;
373 sym
= (ElfW(Sym
) *)s
->data
+ 1;
374 for(sym_index
= 1; sym_index
< nb_syms
; sym_index
++) {
375 if (ELFW(ST_BIND
)(sym
->st_info
) != STB_LOCAL
) {
376 h
= elf_hash(strtab
+ sym
->st_name
) % nb_buckets
;
387 /* return the symbol number */
388 ST_FUNC
int put_elf_sym(Section
*s
, addr_t value
, unsigned long size
,
389 int info
, int other
, int shndx
, const char *name
)
391 int name_offset
, sym_index
;
396 sym
= section_ptr_add(s
, sizeof(ElfW(Sym
)));
398 name_offset
= put_elf_str(s
->link
, name
);
401 /* XXX: endianness */
402 sym
->st_name
= name_offset
;
403 sym
->st_value
= value
;
406 sym
->st_other
= other
;
407 sym
->st_shndx
= shndx
;
408 sym_index
= sym
- (ElfW(Sym
) *)s
->data
;
412 ptr
= section_ptr_add(hs
, sizeof(int));
413 base
= (int *)hs
->data
;
414 /* only add global or weak symbols. */
415 if (ELFW(ST_BIND
)(info
) != STB_LOCAL
) {
416 /* add another hashing entry */
418 h
= elf_hash((unsigned char *)s
->link
->data
+ name_offset
) % nbuckets
;
420 base
[2 + h
] = sym_index
;
422 /* we resize the hash table */
423 hs
->nb_hashed_syms
++;
424 if (hs
->nb_hashed_syms
> 2 * nbuckets
) {
425 rebuild_hash(s
, 2 * nbuckets
);
435 ST_FUNC
int find_elf_sym(Section
*s
, const char *name
)
439 int nbuckets
, sym_index
, h
;
445 nbuckets
= ((int *)hs
->data
)[0];
446 h
= elf_hash((unsigned char *) name
) % nbuckets
;
447 sym_index
= ((int *)hs
->data
)[2 + h
];
448 while (sym_index
!= 0) {
449 sym
= &((ElfW(Sym
) *)s
->data
)[sym_index
];
450 name1
= (char *) s
->link
->data
+ sym
->st_name
;
451 if (!strcmp(name
, name1
))
453 sym_index
= ((int *)hs
->data
)[2 + nbuckets
+ sym_index
];
458 /* return elf symbol value, signal error if 'err' is nonzero */
459 ST_FUNC addr_t
get_elf_sym_addr(TCCState
*s
, const char *name
, int err
)
464 sym_index
= find_elf_sym(s
->symtab
, name
);
465 sym
= &((ElfW(Sym
) *)s
->symtab
->data
)[sym_index
];
466 if (!sym_index
|| sym
->st_shndx
== SHN_UNDEF
) {
468 tcc_error("%s not defined", name
);
471 return sym
->st_value
;
474 /* return elf symbol value */
475 LIBTCCAPI
void *tcc_get_symbol(TCCState
*s
, const char *name
)
477 return (void*)(uintptr_t)get_elf_sym_addr(s
, name
, 0);
480 #if defined TCC_IS_NATIVE || defined TCC_TARGET_PE
481 /* return elf symbol value or error */
482 ST_FUNC
void* tcc_get_symbol_err(TCCState
*s
, const char *name
)
484 return (void*)(uintptr_t)get_elf_sym_addr(s
, name
, 1);
488 /* add an elf symbol : check if it is already defined and patch
489 it. Return symbol index. NOTE that sh_num can be SHN_UNDEF. */
490 ST_FUNC
int set_elf_sym(Section
*s
, addr_t value
, unsigned long size
,
491 int info
, int other
, int shndx
, const char *name
)
494 int sym_bind
, sym_index
, sym_type
, esym_bind
;
495 unsigned char sym_vis
, esym_vis
, new_vis
;
497 sym_bind
= ELFW(ST_BIND
)(info
);
498 sym_type
= ELFW(ST_TYPE
)(info
);
499 sym_vis
= ELFW(ST_VISIBILITY
)(other
);
501 if (sym_bind
!= STB_LOCAL
) {
502 /* we search global or weak symbols */
503 sym_index
= find_elf_sym(s
, name
);
506 esym
= &((ElfW(Sym
) *)s
->data
)[sym_index
];
507 if (esym
->st_value
== value
&& esym
->st_size
== size
&& esym
->st_info
== info
508 && esym
->st_other
== other
&& esym
->st_shndx
== shndx
)
510 if (esym
->st_shndx
!= SHN_UNDEF
) {
511 esym_bind
= ELFW(ST_BIND
)(esym
->st_info
);
512 /* propagate the most constraining visibility */
513 /* STV_DEFAULT(0)<STV_PROTECTED(3)<STV_HIDDEN(2)<STV_INTERNAL(1) */
514 esym_vis
= ELFW(ST_VISIBILITY
)(esym
->st_other
);
515 if (esym_vis
== STV_DEFAULT
) {
517 } else if (sym_vis
== STV_DEFAULT
) {
520 new_vis
= (esym_vis
< sym_vis
) ? esym_vis
: sym_vis
;
522 esym
->st_other
= (esym
->st_other
& ~ELFW(ST_VISIBILITY
)(-1))
524 other
= esym
->st_other
; /* in case we have to patch esym */
525 if (shndx
== SHN_UNDEF
) {
526 /* ignore adding of undefined symbol if the
527 corresponding symbol is already defined */
528 } else if (sym_bind
== STB_GLOBAL
&& esym_bind
== STB_WEAK
) {
529 /* global overrides weak, so patch */
531 } else if (sym_bind
== STB_WEAK
&& esym_bind
== STB_GLOBAL
) {
532 /* weak is ignored if already global */
533 } else if (sym_bind
== STB_WEAK
&& esym_bind
== STB_WEAK
) {
534 /* keep first-found weak definition, ignore subsequents */
535 } else if (sym_vis
== STV_HIDDEN
|| sym_vis
== STV_INTERNAL
) {
536 /* ignore hidden symbols after */
537 } else if ((esym
->st_shndx
== SHN_COMMON
538 || esym
->st_shndx
== bss_section
->sh_num
)
539 && (shndx
< SHN_LORESERVE
540 && shndx
!= bss_section
->sh_num
)) {
541 /* data symbol gets precedence over common/bss */
543 } else if (shndx
== SHN_COMMON
|| shndx
== bss_section
->sh_num
) {
544 /* data symbol keeps precedence over common/bss */
545 } else if (s
->sh_flags
& SHF_DYNSYM
) {
546 /* we accept that two DLL define the same symbol */
547 } else if (esym
->st_other
& ST_ASM_SET
) {
548 /* If the existing symbol came from an asm .set
553 printf("new_bind=%x new_shndx=%x new_vis=%x old_bind=%x old_shndx=%x old_vis=%x\n",
554 sym_bind
, shndx
, new_vis
, esym_bind
, esym
->st_shndx
, esym_vis
);
556 tcc_error_noabort("'%s' defined twice", name
);
560 esym
->st_info
= ELFW(ST_INFO
)(sym_bind
, sym_type
);
561 esym
->st_shndx
= shndx
;
563 esym
->st_value
= value
;
564 esym
->st_size
= size
;
565 esym
->st_other
= other
;
569 sym_index
= put_elf_sym(s
, value
, size
,
570 ELFW(ST_INFO
)(sym_bind
, sym_type
), other
,
577 ST_FUNC
void put_elf_reloca(Section
*symtab
, Section
*s
, unsigned long offset
,
578 int type
, int symbol
, addr_t addend
)
586 /* if no relocation section, create it */
587 snprintf(buf
, sizeof(buf
), REL_SECTION_FMT
, s
->name
);
588 /* if the symtab is allocated, then we consider the relocation
590 sr
= new_section(tcc_state
, buf
, SHT_RELX
, symtab
->sh_flags
);
591 sr
->sh_entsize
= sizeof(ElfW_Rel
);
593 sr
->sh_info
= s
->sh_num
;
596 rel
= section_ptr_add(sr
, sizeof(ElfW_Rel
));
597 rel
->r_offset
= offset
;
598 rel
->r_info
= ELFW(R_INFO
)(symbol
, type
);
599 #if SHT_RELX == SHT_RELA
600 rel
->r_addend
= addend
;
603 tcc_error("non-zero addend on REL architecture");
607 ST_FUNC
void put_elf_reloc(Section
*symtab
, Section
*s
, unsigned long offset
,
608 int type
, int symbol
)
610 put_elf_reloca(symtab
, s
, offset
, type
, symbol
, 0);
613 /* Remove relocations for section S->reloc starting at oldrelocoffset
614 that are to the same place, retaining the last of them. As side effect
615 the relocations are sorted. Possibly reduces the number of relocs. */
616 ST_FUNC
void squeeze_multi_relocs(Section
*s
, size_t oldrelocoffset
)
618 Section
*sr
= s
->reloc
;
623 if (oldrelocoffset
+ sizeof(*r
) >= sr
->data_offset
)
625 /* The relocs we're dealing with are the result of initializer parsing.
626 So they will be mostly in order and there aren't many of them.
627 Secondly we need a stable sort (which qsort isn't). We use
628 a simple insertion sort. */
629 for (a
= oldrelocoffset
+ sizeof(*r
); a
< sr
->data_offset
; a
+= sizeof(*r
)) {
630 ssize_t i
= a
- sizeof(*r
);
631 addr
= ((ElfW_Rel
*)(sr
->data
+ a
))->r_offset
;
632 for (; i
>= (ssize_t
)oldrelocoffset
&&
633 ((ElfW_Rel
*)(sr
->data
+ i
))->r_offset
> addr
; i
-= sizeof(*r
)) {
634 ElfW_Rel tmp
= *(ElfW_Rel
*)(sr
->data
+ a
);
635 *(ElfW_Rel
*)(sr
->data
+ a
) = *(ElfW_Rel
*)(sr
->data
+ i
);
636 *(ElfW_Rel
*)(sr
->data
+ i
) = tmp
;
640 r
= (ElfW_Rel
*)(sr
->data
+ oldrelocoffset
);
642 for (; r
< (ElfW_Rel
*)(sr
->data
+ sr
->data_offset
); r
++) {
643 if (dest
->r_offset
!= r
->r_offset
)
647 sr
->data_offset
= (unsigned char*)dest
- sr
->data
+ sizeof(*r
);
650 /* put stab debug information */
652 ST_FUNC
void put_stabs(const char *str
, int type
, int other
, int desc
,
657 sym
= section_ptr_add(stab_section
, sizeof(Stab_Sym
));
659 sym
->n_strx
= put_elf_str(stabstr_section
, str
);
664 sym
->n_other
= other
;
666 sym
->n_value
= value
;
669 ST_FUNC
void put_stabs_r(const char *str
, int type
, int other
, int desc
,
670 unsigned long value
, Section
*sec
, int sym_index
)
672 put_stabs(str
, type
, other
, desc
, value
);
673 put_elf_reloc(symtab_section
, stab_section
,
674 stab_section
->data_offset
- sizeof(unsigned int),
675 R_DATA_32
, sym_index
);
678 ST_FUNC
void put_stabn(int type
, int other
, int desc
, int value
)
680 put_stabs(NULL
, type
, other
, desc
, value
);
683 ST_FUNC
void put_stabd(int type
, int other
, int desc
)
685 put_stabs(NULL
, type
, other
, desc
, 0);
688 ST_FUNC
struct sym_attr
*get_sym_attr(TCCState
*s1
, int index
, int alloc
)
691 struct sym_attr
*tab
;
693 if (index
>= s1
->nb_sym_attrs
) {
695 return s1
->sym_attrs
;
696 /* find immediately bigger power of 2 and reallocate array */
700 tab
= tcc_realloc(s1
->sym_attrs
, n
* sizeof(*s1
->sym_attrs
));
702 memset(s1
->sym_attrs
+ s1
->nb_sym_attrs
, 0,
703 (n
- s1
->nb_sym_attrs
) * sizeof(*s1
->sym_attrs
));
704 s1
->nb_sym_attrs
= n
;
706 return &s1
->sym_attrs
[index
];
709 /* Browse each elem of type <type> in section <sec> starting at elem <startoff>
710 using variable <elem> */
711 #define for_each_elem(sec, startoff, elem, type) \
712 for (elem = (type *) sec->data + startoff; \
713 elem < (type *) (sec->data + sec->data_offset); elem++)
715 /* In an ELF file symbol table, the local symbols must appear below
716 the global and weak ones. Since TCC cannot sort it while generating
717 the code, we must do it after. All the relocation tables are also
718 modified to take into account the symbol table sorting */
719 static void sort_syms(TCCState
*s1
, Section
*s
)
721 int *old_to_new_syms
;
729 nb_syms
= s
->data_offset
/ sizeof(ElfW(Sym
));
730 new_syms
= tcc_malloc(nb_syms
* sizeof(ElfW(Sym
)));
731 old_to_new_syms
= tcc_malloc(nb_syms
* sizeof(int));
733 /* first pass for local symbols */
734 p
= (ElfW(Sym
) *)s
->data
;
736 for(i
= 0; i
< nb_syms
; i
++) {
737 if (ELFW(ST_BIND
)(p
->st_info
) == STB_LOCAL
) {
738 old_to_new_syms
[i
] = q
- new_syms
;
743 /* save the number of local symbols in section header */
744 if( s
->sh_size
) /* this 'if' makes IDA happy */
745 s
->sh_info
= q
- new_syms
;
747 /* then second pass for non local symbols */
748 p
= (ElfW(Sym
) *)s
->data
;
749 for(i
= 0; i
< nb_syms
; i
++) {
750 if (ELFW(ST_BIND
)(p
->st_info
) != STB_LOCAL
) {
751 old_to_new_syms
[i
] = q
- new_syms
;
757 /* we copy the new symbols to the old */
758 memcpy(s
->data
, new_syms
, nb_syms
* sizeof(ElfW(Sym
)));
761 /* now we modify all the relocations */
762 for(i
= 1; i
< s1
->nb_sections
; i
++) {
763 sr
= s1
->sections
[i
];
764 if (sr
->sh_type
== SHT_RELX
&& sr
->link
== s
) {
765 for_each_elem(sr
, 0, rel
, ElfW_Rel
) {
766 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
767 type
= ELFW(R_TYPE
)(rel
->r_info
);
768 sym_index
= old_to_new_syms
[sym_index
];
769 rel
->r_info
= ELFW(R_INFO
)(sym_index
, type
);
774 tcc_free(old_to_new_syms
);
777 /* relocate symbol table, resolve undefined symbols if do_resolve is
778 true and output error if undefined symbol. */
779 ST_FUNC
void relocate_syms(TCCState
*s1
, Section
*symtab
, int do_resolve
)
782 int sym_bind
, sh_num
;
785 for_each_elem(symtab
, 1, sym
, ElfW(Sym
)) {
786 sh_num
= sym
->st_shndx
;
787 if (sh_num
== SHN_UNDEF
) {
788 name
= (char *) s1
->symtab
->link
->data
+ sym
->st_name
;
789 /* Use ld.so to resolve symbol for us (for tcc -run) */
791 #if defined TCC_IS_NATIVE && !defined TCC_TARGET_PE
792 void *addr
= dlsym(RTLD_DEFAULT
, name
);
794 sym
->st_value
= (addr_t
) addr
;
796 printf ("relocate_sym: %s -> 0x%lx\n", name
, sym
->st_value
);
801 /* if dynamic symbol exist, it will be used in relocate_section */
802 } else if (s1
->dynsym
&& find_elf_sym(s1
->dynsym
, name
))
804 /* XXX: _fp_hw seems to be part of the ABI, so we ignore
806 if (!strcmp(name
, "_fp_hw"))
808 /* only weak symbols are accepted to be undefined. Their
810 sym_bind
= ELFW(ST_BIND
)(sym
->st_info
);
811 if (sym_bind
== STB_WEAK
)
814 tcc_error_noabort("undefined symbol '%s'", name
);
815 } else if (sh_num
< SHN_LORESERVE
) {
816 /* add section base */
817 sym
->st_value
+= s1
->sections
[sym
->st_shndx
]->sh_addr
;
823 /* relocate a given section (CPU dependent) by applying the relocations
824 in the associated relocation section */
825 ST_FUNC
void relocate_section(TCCState
*s1
, Section
*s
)
827 Section
*sr
= s
->reloc
;
836 for_each_elem(sr
, 0, rel
, ElfW_Rel
) {
837 ptr
= s
->data
+ rel
->r_offset
;
838 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
839 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
840 type
= ELFW(R_TYPE
)(rel
->r_info
);
842 #if SHT_RELX == SHT_RELA
843 tgt
+= rel
->r_addend
;
845 addr
= s
->sh_addr
+ rel
->r_offset
;
846 relocate(s1
, rel
, type
, ptr
, addr
, tgt
);
848 /* if the relocation is allocated, we change its symbol table */
849 if (sr
->sh_flags
& SHF_ALLOC
)
850 sr
->link
= s1
->dynsym
;
853 /* relocate relocation table in 'sr' */
854 static void relocate_rel(TCCState
*s1
, Section
*sr
)
859 s
= s1
->sections
[sr
->sh_info
];
860 for_each_elem(sr
, 0, rel
, ElfW_Rel
)
861 rel
->r_offset
+= s
->sh_addr
;
864 /* count the number of dynamic relocations so that we can reserve
866 static int prepare_dynamic_rel(TCCState
*s1
, Section
*sr
)
872 for_each_elem(sr
, 0, rel
, ElfW_Rel
) {
873 #if defined(TCC_TARGET_I386) || defined(TCC_TARGET_X86_64)
874 int sym_index
= ELFW(R_SYM
)(rel
->r_info
);
876 type
= ELFW(R_TYPE
)(rel
->r_info
);
878 #if defined(TCC_TARGET_I386) || defined(TCC_TARGET_X86_64)
879 #if defined(TCC_TARGET_I386)
881 if (!get_sym_attr(s1
, sym_index
, 0)->dyn_index
882 && ((ElfW(Sym
)*)symtab_section
->data
+ sym_index
)->st_shndx
== SHN_UNDEF
) {
883 /* don't fixup unresolved (weak) symbols */
884 rel
->r_info
= ELFW(R_INFO
)(sym_index
, R_386_RELATIVE
);
887 #elif defined(TCC_TARGET_X86_64)
894 #if defined(TCC_TARGET_I386)
896 #elif defined(TCC_TARGET_X86_64)
899 if (get_sym_attr(s1
, sym_index
, 0)->dyn_index
)
908 /* allocate the section */
909 sr
->sh_flags
|= SHF_ALLOC
;
910 sr
->sh_size
= count
* sizeof(ElfW_Rel
);
915 static void build_got(TCCState
*s1
)
917 /* if no got, then create it */
918 s1
->got
= new_section(s1
, ".got", SHT_PROGBITS
, SHF_ALLOC
| SHF_WRITE
);
919 s1
->got
->sh_entsize
= 4;
920 set_elf_sym(symtab_section
, 0, 4, ELFW(ST_INFO
)(STB_GLOBAL
, STT_OBJECT
),
921 0, s1
->got
->sh_num
, "_GLOBAL_OFFSET_TABLE_");
922 /* keep space for _DYNAMIC pointer and two dummy got entries */
923 section_ptr_add(s1
->got
, 3 * PTR_SIZE
);
926 /* Create a GOT and (for function call) a PLT entry corresponding to a symbol
927 in s1->symtab. When creating the dynamic symbol table entry for the GOT
928 relocation, use 'size' and 'info' for the corresponding symbol metadata.
929 Returns the offset of the GOT or (if any) PLT entry. */
930 static struct sym_attr
* put_got_entry(TCCState
*s1
, int dyn_reloc_type
,
932 int info
, int sym_index
)
937 struct sym_attr
*attr
;
942 need_plt_entry
= (dyn_reloc_type
== R_JMP_SLOT
);
943 attr
= get_sym_attr(s1
, sym_index
, 1);
945 /* In case a function is both called and its address taken 2 GOT entries
946 are created, one for taking the address (GOT) and the other for the PLT
948 if (need_plt_entry
? attr
->plt_offset
: attr
->got_offset
)
951 /* create the GOT entry */
952 got_offset
= s1
->got
->data_offset
;
953 section_ptr_add(s1
->got
, PTR_SIZE
);
955 /* Create the GOT relocation that will insert the address of the object or
956 function of interest in the GOT entry. This is a static relocation for
957 memory output (dlsym will give us the address of symbols) and dynamic
958 relocation otherwise (executable and DLLs). The relocation should be
959 done lazily for GOT entry with *_JUMP_SLOT relocation type (the one
960 associated to a PLT entry) but is currently done at load time for an
963 sym
= &((ElfW(Sym
) *) symtab_section
->data
)[sym_index
];
964 name
= (char *) symtab_section
->link
->data
+ sym
->st_name
;
967 if (ELFW(ST_BIND
)(sym
->st_info
) == STB_LOCAL
) {
968 /* Hack alarm. We don't want to emit dynamic symbols
969 and symbol based relocs for STB_LOCAL symbols, but rather
970 want to resolve them directly. At this point the symbol
971 values aren't final yet, so we must defer this. We will later
972 have to create a RELATIVE reloc anyway, so we misuse the
973 relocation slot to smuggle the symbol reference until
974 fill_local_got_entries. Not that the sym_index is
975 relative to symtab_section, not s1->dynsym! Nevertheless
976 we use s1->dyn_sym so that if this is the first call
977 that got->reloc is correctly created. Also note that
978 RELATIVE relocs are not normally created for the .got,
979 so the types serves as a marker for later (and is retained
980 also for the final output, which is okay because then the
981 got is just normal data). */
982 put_elf_reloc(s1
->dynsym
, s1
->got
, got_offset
, R_RELATIVE
,
985 if (0 == attr
->dyn_index
)
986 attr
->dyn_index
= set_elf_sym(s1
->dynsym
, sym
->st_value
, size
,
987 info
, 0, sym
->st_shndx
, name
);
988 put_elf_reloc(s1
->dynsym
, s1
->got
, got_offset
, dyn_reloc_type
,
992 put_elf_reloc(symtab_section
, s1
->got
, got_offset
, dyn_reloc_type
,
996 if (need_plt_entry
) {
998 s1
->plt
= new_section(s1
, ".plt", SHT_PROGBITS
,
999 SHF_ALLOC
| SHF_EXECINSTR
);
1000 s1
->plt
->sh_entsize
= 4;
1003 attr
->plt_offset
= create_plt_entry(s1
, got_offset
, attr
);
1005 /* create a symbol 'sym@plt' for the PLT jump vector */
1007 if (len
> sizeof plt_name
- 5)
1008 len
= sizeof plt_name
- 5;
1009 memcpy(plt_name
, name
, len
);
1010 strcpy(plt_name
+ len
, "@plt");
1011 attr
->plt_sym
= put_elf_sym(s1
->symtab
, attr
->plt_offset
, sym
->st_size
,
1012 ELFW(ST_INFO
)(STB_GLOBAL
, STT_FUNC
), 0, s1
->plt
->sh_num
, plt_name
);
1015 attr
->got_offset
= got_offset
;
1021 /* build GOT and PLT entries */
1022 ST_FUNC
void build_got_entries(TCCState
*s1
)
1027 int i
, type
, gotplt_entry
, reloc_type
, sym_index
;
1028 struct sym_attr
*attr
;
1030 for(i
= 1; i
< s1
->nb_sections
; i
++) {
1031 s
= s1
->sections
[i
];
1032 if (s
->sh_type
!= SHT_RELX
)
1034 /* no need to handle got relocations */
1035 if (s
->link
!= symtab_section
)
1037 for_each_elem(s
, 0, rel
, ElfW_Rel
) {
1038 type
= ELFW(R_TYPE
)(rel
->r_info
);
1039 gotplt_entry
= gotplt_entry_type(type
);
1040 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
1041 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
1043 if (gotplt_entry
== NO_GOTPLT_ENTRY
) {
1047 /* Automatically create PLT/GOT [entry] if it is an undefined
1048 reference (resolved at runtime), or the symbol is absolute,
1049 probably created by tcc_add_symbol, and thus on 64-bit
1050 targets might be too far from application code. */
1051 if (gotplt_entry
== AUTO_GOTPLT_ENTRY
) {
1052 if (sym
->st_shndx
== SHN_UNDEF
) {
1055 if (s1
->output_type
== TCC_OUTPUT_DLL
&& ! PCRELATIVE_DLLPLT
)
1057 /* Relocations for UNDEF symbols would normally need
1058 to be transferred into the executable or shared object.
1059 If that were done AUTO_GOTPLT_ENTRY wouldn't exist.
1060 But TCC doesn't do that (at least for exes), so we
1061 need to resolve all such relocs locally. And that
1062 means PLT slots for functions in DLLs and COPY relocs for
1063 data symbols. COPY relocs were generated in
1064 bind_exe_dynsyms (and the symbol adjusted to be defined),
1065 and for functions we were generated a dynamic symbol
1066 of function type. */
1068 /* dynsym isn't set for -run :-/ */
1069 dynindex
= get_sym_attr(s1
, sym_index
, 0)->dyn_index
;
1070 esym
= (ElfW(Sym
) *)s1
->dynsym
->data
+ dynindex
;
1072 && (ELFW(ST_TYPE
)(esym
->st_info
) == STT_FUNC
1073 || (ELFW(ST_TYPE
)(esym
->st_info
) == STT_NOTYPE
1074 && ELFW(ST_TYPE
)(sym
->st_info
) == STT_FUNC
)))
1077 } else if (!(sym
->st_shndx
== SHN_ABS
1078 #ifndef TCC_TARGET_ARM
1085 #ifdef TCC_TARGET_X86_64
1086 if ((type
== R_X86_64_PLT32
|| type
== R_X86_64_PC32
) &&
1087 sym
->st_shndx
!= SHN_UNDEF
&&
1088 (ELFW(ST_VISIBILITY
)(sym
->st_other
) != STV_DEFAULT
||
1089 ELFW(ST_BIND
)(sym
->st_info
) == STB_LOCAL
||
1090 s1
->output_type
== TCC_OUTPUT_EXE
)) {
1091 rel
->r_info
= ELFW(R_INFO
)(sym_index
, R_X86_64_PC32
);
1095 if (code_reloc(type
)) {
1097 reloc_type
= R_JMP_SLOT
;
1099 reloc_type
= R_GLOB_DAT
;
1104 if (gotplt_entry
== BUILD_GOT_ONLY
)
1107 attr
= put_got_entry(s1
, reloc_type
, sym
->st_size
, sym
->st_info
,
1110 if (reloc_type
== R_JMP_SLOT
)
1111 rel
->r_info
= ELFW(R_INFO
)(attr
->plt_sym
, type
);
1116 /* put dynamic tag */
1117 static void put_dt(Section
*dynamic
, int dt
, addr_t val
)
1120 dyn
= section_ptr_add(dynamic
, sizeof(ElfW(Dyn
)));
1122 dyn
->d_un
.d_val
= val
;
1125 #ifndef TCC_TARGET_PE
1126 static void add_init_array_defines(TCCState
*s1
, const char *section_name
)
1130 char sym_start
[1024];
1133 snprintf(sym_start
, sizeof(sym_start
), "__%s_start", section_name
+ 1);
1134 snprintf(sym_end
, sizeof(sym_end
), "__%s_end", section_name
+ 1);
1136 s
= find_section(s1
, section_name
);
1141 end_offset
= s
->data_offset
;
1144 set_elf_sym(symtab_section
,
1146 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1147 s
->sh_num
, sym_start
);
1148 set_elf_sym(symtab_section
,
1150 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1151 s
->sh_num
, sym_end
);
1154 static int tcc_add_support(TCCState
*s1
, const char *filename
)
1157 snprintf(buf
, sizeof(buf
), "%s/%s", s1
->tcc_lib_path
, filename
);
1158 return tcc_add_file(s1
, buf
);
1162 ST_FUNC
void tcc_add_bcheck(TCCState
*s1
)
1164 #ifdef CONFIG_TCC_BCHECK
1168 if (0 == s1
->do_bounds_check
)
1170 /* XXX: add an object file to do that */
1171 ptr
= section_ptr_add(bounds_section
, sizeof(*ptr
));
1173 set_elf_sym(symtab_section
, 0, 0,
1174 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1175 bounds_section
->sh_num
, "__bounds_start");
1176 /* pull bcheck.o from libtcc1.a */
1177 sym_index
= set_elf_sym(symtab_section
, 0, 0,
1178 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1179 SHN_UNDEF
, "__bound_init");
1180 if (s1
->output_type
!= TCC_OUTPUT_MEMORY
) {
1181 /* add 'call __bound_init()' in .init section */
1182 Section
*init_section
= find_section(s1
, ".init");
1183 unsigned char *pinit
= section_ptr_add(init_section
, 5);
1185 write32le(pinit
+ 1, -4);
1186 put_elf_reloc(symtab_section
, init_section
,
1187 init_section
->data_offset
- 4, R_386_PC32
, sym_index
);
1188 /* R_386_PC32 = R_X86_64_PC32 = 2 */
1193 /* add tcc runtime libraries */
1194 ST_FUNC
void tcc_add_runtime(TCCState
*s1
)
1198 tcc_add_pragma_libs(s1
);
1199 #ifndef TCC_TARGET_PE
1201 if (!s1
->nostdlib
) {
1202 tcc_add_library_err(s1
, "c");
1204 if (!s1
->static_link
) {
1205 if (TCC_LIBGCC
[0] == '/')
1206 tcc_add_file(s1
, TCC_LIBGCC
);
1208 tcc_add_dll(s1
, TCC_LIBGCC
, 0);
1211 tcc_add_support(s1
, TCC_LIBTCC1
);
1212 /* add crt end if not memory output */
1213 if (s1
->output_type
!= TCC_OUTPUT_MEMORY
)
1214 tcc_add_crt(s1
, "crtn.o");
1219 /* add various standard linker symbols (must be done after the
1220 sections are filled (for example after allocating common
1222 static void tcc_add_linker_symbols(TCCState
*s1
)
1228 set_elf_sym(symtab_section
,
1229 text_section
->data_offset
, 0,
1230 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1231 text_section
->sh_num
, "_etext");
1232 set_elf_sym(symtab_section
,
1233 data_section
->data_offset
, 0,
1234 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1235 data_section
->sh_num
, "_edata");
1236 set_elf_sym(symtab_section
,
1237 bss_section
->data_offset
, 0,
1238 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1239 bss_section
->sh_num
, "_end");
1240 #ifndef TCC_TARGET_PE
1241 /* horrible new standard ldscript defines */
1242 add_init_array_defines(s1
, ".preinit_array");
1243 add_init_array_defines(s1
, ".init_array");
1244 add_init_array_defines(s1
, ".fini_array");
1247 /* add start and stop symbols for sections whose name can be
1249 for(i
= 1; i
< s1
->nb_sections
; i
++) {
1250 s
= s1
->sections
[i
];
1251 if (s
->sh_type
== SHT_PROGBITS
&&
1252 (s
->sh_flags
& SHF_ALLOC
)) {
1256 /* check if section name can be expressed in C */
1262 if (!isid(ch
) && !isnum(ch
))
1266 snprintf(buf
, sizeof(buf
), "__start_%s", s
->name
);
1267 set_elf_sym(symtab_section
,
1269 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1271 snprintf(buf
, sizeof(buf
), "__stop_%s", s
->name
);
1272 set_elf_sym(symtab_section
,
1274 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1281 ST_FUNC
void resolve_common_syms(TCCState
*s1
)
1285 /* Allocate common symbols in BSS. */
1286 for_each_elem(symtab_section
, 1, sym
, ElfW(Sym
)) {
1287 if (sym
->st_shndx
== SHN_COMMON
) {
1288 /* symbol alignment is in st_value for SHN_COMMONs */
1289 sym
->st_value
= section_add(bss_section
, sym
->st_size
,
1291 sym
->st_shndx
= bss_section
->sh_num
;
1295 /* Now assign linker provided symbols their value. */
1296 tcc_add_linker_symbols(s1
);
1299 static void tcc_output_binary(TCCState
*s1
, FILE *f
,
1300 const int *sec_order
)
1303 int i
, offset
, size
;
1306 for(i
=1;i
<s1
->nb_sections
;i
++) {
1307 s
= s1
->sections
[sec_order
[i
]];
1308 if (s
->sh_type
!= SHT_NOBITS
&&
1309 (s
->sh_flags
& SHF_ALLOC
)) {
1310 while (offset
< s
->sh_offset
) {
1315 fwrite(s
->data
, 1, size
, f
);
1321 ST_FUNC
void fill_got_entry(TCCState
*s1
, ElfW_Rel
*rel
)
1323 int sym_index
= ELFW(R_SYM
) (rel
->r_info
);
1324 ElfW(Sym
) *sym
= &((ElfW(Sym
) *) symtab_section
->data
)[sym_index
];
1325 struct sym_attr
*attr
= get_sym_attr(s1
, sym_index
, 0);
1326 unsigned offset
= attr
->got_offset
;
1330 section_reserve(s1
->got
, offset
+ PTR_SIZE
);
1331 #ifdef TCC_TARGET_X86_64
1332 write64le(s1
->got
->data
+ offset
, sym
->st_value
);
1334 write32le(s1
->got
->data
+ offset
, sym
->st_value
);
1338 /* Perform relocation to GOT or PLT entries */
1339 ST_FUNC
void fill_got(TCCState
*s1
)
1345 for(i
= 1; i
< s1
->nb_sections
; i
++) {
1346 s
= s1
->sections
[i
];
1347 if (s
->sh_type
!= SHT_RELX
)
1349 /* no need to handle got relocations */
1350 if (s
->link
!= symtab_section
)
1352 for_each_elem(s
, 0, rel
, ElfW_Rel
) {
1353 switch (ELFW(R_TYPE
) (rel
->r_info
)) {
1354 case R_X86_64_GOT32
:
1355 case R_X86_64_GOTPCREL
:
1356 case R_X86_64_GOTPCRELX
:
1357 case R_X86_64_REX_GOTPCRELX
:
1358 case R_X86_64_PLT32
:
1359 fill_got_entry(s1
, rel
);
1366 /* See put_got_entry for a description. This is the second stage
1367 where GOT references to local defined symbols are rewritten. */
1368 static void fill_local_got_entries(TCCState
*s1
)
1371 if (!s1
->got
->reloc
)
1373 for_each_elem(s1
->got
->reloc
, 0, rel
, ElfW_Rel
) {
1374 if (ELFW(R_TYPE
)(rel
->r_info
) == R_RELATIVE
) {
1375 int sym_index
= ELFW(R_SYM
) (rel
->r_info
);
1376 ElfW(Sym
) *sym
= &((ElfW(Sym
) *) symtab_section
->data
)[sym_index
];
1377 struct sym_attr
*attr
= get_sym_attr(s1
, sym_index
, 0);
1378 unsigned offset
= attr
->got_offset
;
1379 if (offset
!= rel
->r_offset
- s1
->got
->sh_addr
)
1380 tcc_error_noabort("huh");
1381 rel
->r_info
= ELFW(R_INFO
)(0, R_RELATIVE
);
1382 #if SHT_RELX == SHT_RELA
1383 rel
->r_addend
= sym
->st_value
;
1385 /* All our REL architectures also happen to be 32bit LE. */
1386 write32le(s1
->got
->data
+ offset
, sym
->st_value
);
1392 /* Bind symbols of executable: resolve undefined symbols from exported symbols
1393 in shared libraries and export non local defined symbols to shared libraries
1394 if -rdynamic switch was given on command line */
1395 static void bind_exe_dynsyms(TCCState
*s1
)
1398 int sym_index
, index
;
1399 ElfW(Sym
) *sym
, *esym
;
1402 /* Resolve undefined symbols from dynamic symbols. When there is a match:
1403 - if STT_FUNC or STT_GNU_IFUNC symbol -> add it in PLT
1404 - if STT_OBJECT symbol -> add it in .bss section with suitable reloc */
1405 for_each_elem(symtab_section
, 1, sym
, ElfW(Sym
)) {
1406 if (sym
->st_shndx
== SHN_UNDEF
) {
1407 name
= (char *) symtab_section
->link
->data
+ sym
->st_name
;
1408 sym_index
= find_elf_sym(s1
->dynsymtab_section
, name
);
1410 esym
= &((ElfW(Sym
) *)s1
->dynsymtab_section
->data
)[sym_index
];
1411 type
= ELFW(ST_TYPE
)(esym
->st_info
);
1412 if ((type
== STT_FUNC
) || (type
== STT_GNU_IFUNC
)) {
1413 /* Indirect functions shall have STT_FUNC type in executable
1414 * dynsym section. Indeed, a dlsym call following a lazy
1415 * resolution would pick the symbol value from the
1416 * executable dynsym entry which would contain the address
1417 * of the function wanted by the caller of dlsym instead of
1418 * the address of the function that would return that
1421 = put_elf_sym(s1
->dynsym
, 0, esym
->st_size
,
1422 ELFW(ST_INFO
)(STB_GLOBAL
,STT_FUNC
), 0, 0,
1424 int index
= sym
- (ElfW(Sym
) *) symtab_section
->data
;
1425 get_sym_attr(s1
, index
, 1)->dyn_index
= dynindex
;
1426 } else if (type
== STT_OBJECT
) {
1427 unsigned long offset
;
1429 offset
= bss_section
->data_offset
;
1430 /* XXX: which alignment ? */
1431 offset
= (offset
+ 16 - 1) & -16;
1432 set_elf_sym (s1
->symtab
, offset
, esym
->st_size
,
1433 esym
->st_info
, 0, bss_section
->sh_num
, name
);
1434 index
= put_elf_sym(s1
->dynsym
, offset
, esym
->st_size
,
1435 esym
->st_info
, 0, bss_section
->sh_num
,
1438 /* Ensure R_COPY works for weak symbol aliases */
1439 if (ELFW(ST_BIND
)(esym
->st_info
) == STB_WEAK
) {
1440 for_each_elem(s1
->dynsymtab_section
, 1, dynsym
, ElfW(Sym
)) {
1441 if ((dynsym
->st_value
== esym
->st_value
)
1442 && (ELFW(ST_BIND
)(dynsym
->st_info
) == STB_GLOBAL
)) {
1443 char *dynname
= (char *) s1
->dynsymtab_section
->link
->data
1445 put_elf_sym(s1
->dynsym
, offset
, dynsym
->st_size
,
1447 bss_section
->sh_num
, dynname
);
1453 put_elf_reloc(s1
->dynsym
, bss_section
,
1454 offset
, R_COPY
, index
);
1455 offset
+= esym
->st_size
;
1456 bss_section
->data_offset
= offset
;
1459 /* STB_WEAK undefined symbols are accepted */
1460 /* XXX: _fp_hw seems to be part of the ABI, so we ignore it */
1461 if (ELFW(ST_BIND
)(sym
->st_info
) == STB_WEAK
||
1462 !strcmp(name
, "_fp_hw")) {
1464 tcc_error_noabort("undefined symbol '%s'", name
);
1467 } else if (s1
->rdynamic
&& ELFW(ST_BIND
)(sym
->st_info
) != STB_LOCAL
) {
1468 /* if -rdynamic option, then export all non local symbols */
1469 name
= (char *) symtab_section
->link
->data
+ sym
->st_name
;
1470 set_elf_sym(s1
->dynsym
, sym
->st_value
, sym
->st_size
, sym
->st_info
,
1471 0, sym
->st_shndx
, name
);
1476 /* Bind symbols of libraries: export all non local symbols of executable that
1477 are referenced by shared libraries. The reason is that the dynamic loader
1478 search symbol first in executable and then in libraries. Therefore a
1479 reference to a symbol already defined by a library can still be resolved by
1480 a symbol in the executable. */
1481 static void bind_libs_dynsyms(TCCState
*s1
)
1485 ElfW(Sym
) *sym
, *esym
;
1487 for_each_elem(s1
->dynsymtab_section
, 1, esym
, ElfW(Sym
)) {
1488 name
= (char *) s1
->dynsymtab_section
->link
->data
+ esym
->st_name
;
1489 sym_index
= find_elf_sym(symtab_section
, name
);
1490 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
1491 if (sym_index
&& sym
->st_shndx
!= SHN_UNDEF
1492 && ELFW(ST_BIND
)(sym
->st_info
) != STB_LOCAL
) {
1493 set_elf_sym(s1
->dynsym
, sym
->st_value
, sym
->st_size
,
1494 sym
->st_info
, 0, sym
->st_shndx
, name
);
1495 } else if (esym
->st_shndx
== SHN_UNDEF
) {
1496 /* weak symbols can stay undefined */
1497 if (ELFW(ST_BIND
)(esym
->st_info
) != STB_WEAK
)
1498 tcc_warning("undefined dynamic symbol '%s'", name
);
1503 /* Export all non local symbols. This is used by shared libraries so that the
1504 non local symbols they define can resolve a reference in another shared
1505 library or in the executable. Correspondingly, it allows undefined local
1506 symbols to be resolved by other shared libraries or by the executable. */
1507 static void export_global_syms(TCCState
*s1
)
1509 int dynindex
, index
;
1513 for_each_elem(symtab_section
, 1, sym
, ElfW(Sym
)) {
1514 if (ELFW(ST_BIND
)(sym
->st_info
) != STB_LOCAL
) {
1515 name
= (char *) symtab_section
->link
->data
+ sym
->st_name
;
1516 dynindex
= put_elf_sym(s1
->dynsym
, sym
->st_value
, sym
->st_size
,
1517 sym
->st_info
, 0, sym
->st_shndx
, name
);
1518 index
= sym
- (ElfW(Sym
) *) symtab_section
->data
;
1519 get_sym_attr(s1
, index
, 1)->dyn_index
= dynindex
;
1524 /* Allocate strings for section names and decide if an unallocated section
1526 NOTE: the strsec section comes last, so its size is also correct ! */
1527 static int alloc_sec_names(TCCState
*s1
, int file_type
, Section
*strsec
)
1533 /* Allocate strings for section names */
1534 for(i
= 1; i
< s1
->nb_sections
; i
++) {
1535 s
= s1
->sections
[i
];
1536 /* when generating a DLL, we include relocations but we may
1538 if (file_type
== TCC_OUTPUT_DLL
&&
1539 s
->sh_type
== SHT_RELX
&&
1540 !(s
->sh_flags
& SHF_ALLOC
) &&
1541 (s1
->sections
[s
->sh_info
]->sh_flags
& SHF_ALLOC
) &&
1542 prepare_dynamic_rel(s1
, s
)) {
1543 if (s1
->sections
[s
->sh_info
]->sh_flags
& SHF_EXECINSTR
)
1545 } else if ((s1
->do_debug
&& s
->sh_type
!= SHT_RELX
) ||
1546 file_type
== TCC_OUTPUT_OBJ
||
1547 (s
->sh_flags
& SHF_ALLOC
) ||
1548 i
== (s1
->nb_sections
- 1)) {
1549 /* we output all sections if debug or object file */
1550 s
->sh_size
= s
->data_offset
;
1552 if (s
->sh_size
|| (s
->sh_flags
& SHF_ALLOC
))
1553 s
->sh_name
= put_elf_str(strsec
, s
->name
);
1555 strsec
->sh_size
= strsec
->data_offset
;
1559 /* Info to be copied in dynamic section */
1563 unsigned long data_offset
;
1566 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1572 /* Assign sections to segments and decide how are sections laid out when loaded
1573 in memory. This function also fills corresponding program headers. */
1574 static int layout_sections(TCCState
*s1
, ElfW(Phdr
) *phdr
, int phnum
,
1575 Section
*interp
, Section
* strsec
,
1576 struct dyn_inf
*dyninf
, int *sec_order
)
1578 int i
, j
, k
, file_type
, sh_order_index
, file_offset
;
1579 unsigned long s_align
;
1585 file_type
= s1
->output_type
;
1588 if (s1
->output_format
== TCC_OUTPUT_FORMAT_ELF
)
1589 file_offset
= sizeof(ElfW(Ehdr
)) + phnum
* sizeof(ElfW(Phdr
));
1590 s_align
= ELF_PAGE_SIZE
;
1591 if (s1
->section_align
)
1592 s_align
= s1
->section_align
;
1595 if (s1
->has_text_addr
) {
1596 int a_offset
, p_offset
;
1597 addr
= s1
->text_addr
;
1598 /* we ensure that (addr % ELF_PAGE_SIZE) == file_offset %
1600 a_offset
= (int) (addr
& (s_align
- 1));
1601 p_offset
= file_offset
& (s_align
- 1);
1602 if (a_offset
< p_offset
)
1603 a_offset
+= s_align
;
1604 file_offset
+= (a_offset
- p_offset
);
1606 if (file_type
== TCC_OUTPUT_DLL
)
1609 addr
= ELF_START_ADDR
;
1610 /* compute address after headers */
1611 addr
+= (file_offset
& (s_align
- 1));
1615 /* Leave one program headers for the program interpreter and one for
1616 the program header table itself if needed. These are done later as
1617 they require section layout to be done first. */
1621 /* dynamic relocation table information, for .dynamic section */
1622 dyninf
->rel_addr
= dyninf
->rel_size
= 0;
1623 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1624 dyninf
->bss_addr
= dyninf
->bss_size
= 0;
1627 for(j
= 0; j
< 2; j
++) {
1628 ph
->p_type
= PT_LOAD
;
1630 ph
->p_flags
= PF_R
| PF_X
;
1632 ph
->p_flags
= PF_R
| PF_W
;
1633 ph
->p_align
= s_align
;
1635 /* Decide the layout of sections loaded in memory. This must
1636 be done before program headers are filled since they contain
1637 info about the layout. We do the following ordering: interp,
1638 symbol tables, relocations, progbits, nobits */
1639 /* XXX: do faster and simpler sorting */
1640 for(k
= 0; k
< 5; k
++) {
1641 for(i
= 1; i
< s1
->nb_sections
; i
++) {
1642 s
= s1
->sections
[i
];
1643 /* compute if section should be included */
1645 if ((s
->sh_flags
& (SHF_ALLOC
| SHF_WRITE
)) !=
1649 if ((s
->sh_flags
& (SHF_ALLOC
| SHF_WRITE
)) !=
1650 (SHF_ALLOC
| SHF_WRITE
))
1656 } else if (s
->sh_type
== SHT_DYNSYM
||
1657 s
->sh_type
== SHT_STRTAB
||
1658 s
->sh_type
== SHT_HASH
) {
1661 } else if (s
->sh_type
== SHT_RELX
) {
1664 } else if (s
->sh_type
== SHT_NOBITS
) {
1671 sec_order
[sh_order_index
++] = i
;
1673 /* section matches: we align it and add its size */
1675 addr
= (addr
+ s
->sh_addralign
- 1) &
1676 ~(s
->sh_addralign
- 1);
1677 file_offset
+= (int) ( addr
- tmp
);
1678 s
->sh_offset
= file_offset
;
1681 /* update program header infos */
1682 if (ph
->p_offset
== 0) {
1683 ph
->p_offset
= file_offset
;
1685 ph
->p_paddr
= ph
->p_vaddr
;
1687 /* update dynamic relocation infos */
1688 if (s
->sh_type
== SHT_RELX
) {
1689 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1690 if (!strcmp(strsec
->data
+ s
->sh_name
, ".rel.got")) {
1691 dyninf
->rel_addr
= addr
;
1692 dyninf
->rel_size
+= s
->sh_size
; /* XXX only first rel. */
1694 if (!strcmp(strsec
->data
+ s
->sh_name
, ".rel.bss")) {
1695 dyninf
->bss_addr
= addr
;
1696 dyninf
->bss_size
= s
->sh_size
; /* XXX only first rel. */
1699 if (dyninf
->rel_size
== 0)
1700 dyninf
->rel_addr
= addr
;
1701 dyninf
->rel_size
+= s
->sh_size
;
1705 if (s
->sh_type
!= SHT_NOBITS
)
1706 file_offset
+= s
->sh_size
;
1710 /* Make the first PT_LOAD segment include the program
1711 headers itself (and the ELF header as well), it'll
1712 come out with same memory use but will make various
1713 tools like binutils strip work better. */
1714 ph
->p_offset
&= ~(ph
->p_align
- 1);
1715 ph
->p_vaddr
&= ~(ph
->p_align
- 1);
1716 ph
->p_paddr
&= ~(ph
->p_align
- 1);
1718 ph
->p_filesz
= file_offset
- ph
->p_offset
;
1719 ph
->p_memsz
= addr
- ph
->p_vaddr
;
1722 if (s1
->output_format
== TCC_OUTPUT_FORMAT_ELF
) {
1723 /* if in the middle of a page, we duplicate the page in
1724 memory so that one copy is RX and the other is RW */
1725 if ((addr
& (s_align
- 1)) != 0)
1728 addr
= (addr
+ s_align
- 1) & ~(s_align
- 1);
1729 file_offset
= (file_offset
+ s_align
- 1) & ~(s_align
- 1);
1735 /* all other sections come after */
1736 for(i
= 1; i
< s1
->nb_sections
; i
++) {
1737 s
= s1
->sections
[i
];
1738 if (phnum
> 0 && (s
->sh_flags
& SHF_ALLOC
))
1740 sec_order
[sh_order_index
++] = i
;
1742 file_offset
= (file_offset
+ s
->sh_addralign
- 1) &
1743 ~(s
->sh_addralign
- 1);
1744 s
->sh_offset
= file_offset
;
1745 if (s
->sh_type
!= SHT_NOBITS
)
1746 file_offset
+= s
->sh_size
;
1752 static void fill_unloadable_phdr(ElfW(Phdr
) *phdr
, int phnum
, Section
*interp
,
1757 /* if interpreter, then add corresponding program header */
1761 ph
->p_type
= PT_PHDR
;
1762 ph
->p_offset
= sizeof(ElfW(Ehdr
));
1763 ph
->p_filesz
= ph
->p_memsz
= phnum
* sizeof(ElfW(Phdr
));
1764 ph
->p_vaddr
= interp
->sh_addr
- ph
->p_filesz
;
1765 ph
->p_paddr
= ph
->p_vaddr
;
1766 ph
->p_flags
= PF_R
| PF_X
;
1767 ph
->p_align
= 4; /* interp->sh_addralign; */
1770 ph
->p_type
= PT_INTERP
;
1771 ph
->p_offset
= interp
->sh_offset
;
1772 ph
->p_vaddr
= interp
->sh_addr
;
1773 ph
->p_paddr
= ph
->p_vaddr
;
1774 ph
->p_filesz
= interp
->sh_size
;
1775 ph
->p_memsz
= interp
->sh_size
;
1777 ph
->p_align
= interp
->sh_addralign
;
1780 /* if dynamic section, then add corresponding program header */
1782 ph
= &phdr
[phnum
- 1];
1784 ph
->p_type
= PT_DYNAMIC
;
1785 ph
->p_offset
= dynamic
->sh_offset
;
1786 ph
->p_vaddr
= dynamic
->sh_addr
;
1787 ph
->p_paddr
= ph
->p_vaddr
;
1788 ph
->p_filesz
= dynamic
->sh_size
;
1789 ph
->p_memsz
= dynamic
->sh_size
;
1790 ph
->p_flags
= PF_R
| PF_W
;
1791 ph
->p_align
= dynamic
->sh_addralign
;
1795 /* Fill the dynamic section with tags describing the address and size of
1797 static void fill_dynamic(TCCState
*s1
, struct dyn_inf
*dyninf
)
1799 Section
*dynamic
= dyninf
->dynamic
;
1801 /* put dynamic section entries */
1802 put_dt(dynamic
, DT_HASH
, s1
->dynsym
->hash
->sh_addr
);
1803 put_dt(dynamic
, DT_STRTAB
, dyninf
->dynstr
->sh_addr
);
1804 put_dt(dynamic
, DT_SYMTAB
, s1
->dynsym
->sh_addr
);
1805 put_dt(dynamic
, DT_STRSZ
, dyninf
->dynstr
->data_offset
);
1806 put_dt(dynamic
, DT_SYMENT
, sizeof(ElfW(Sym
)));
1808 put_dt(dynamic
, DT_RELA
, dyninf
->rel_addr
);
1809 put_dt(dynamic
, DT_RELASZ
, dyninf
->rel_size
);
1810 put_dt(dynamic
, DT_RELAENT
, sizeof(ElfW_Rel
));
1812 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1813 put_dt(dynamic
, DT_PLTGOT
, s1
->got
->sh_addr
);
1814 put_dt(dynamic
, DT_PLTRELSZ
, dyninf
->rel_size
);
1815 put_dt(dynamic
, DT_JMPREL
, dyninf
->rel_addr
);
1816 put_dt(dynamic
, DT_PLTREL
, DT_REL
);
1817 put_dt(dynamic
, DT_REL
, dyninf
->bss_addr
);
1818 put_dt(dynamic
, DT_RELSZ
, dyninf
->bss_size
);
1820 put_dt(dynamic
, DT_REL
, dyninf
->rel_addr
);
1821 put_dt(dynamic
, DT_RELSZ
, dyninf
->rel_size
);
1822 put_dt(dynamic
, DT_RELENT
, sizeof(ElfW_Rel
));
1826 put_dt(dynamic
, DT_DEBUG
, 0);
1827 put_dt(dynamic
, DT_NULL
, 0);
1830 /* Relocate remaining sections and symbols (that is those not related to
1832 static int final_sections_reloc(TCCState
*s1
)
1837 relocate_syms(s1
, s1
->symtab
, 0);
1839 if (s1
->nb_errors
!= 0)
1842 /* relocate sections */
1843 /* XXX: ignore sections with allocated relocations ? */
1844 for(i
= 1; i
< s1
->nb_sections
; i
++) {
1845 s
= s1
->sections
[i
];
1846 if (s
->reloc
&& (s
!= s1
->got
|| s1
->static_link
))
1847 relocate_section(s1
, s
);
1850 /* relocate relocation entries if the relocation tables are
1851 allocated in the executable */
1852 for(i
= 1; i
< s1
->nb_sections
; i
++) {
1853 s
= s1
->sections
[i
];
1854 if ((s
->sh_flags
& SHF_ALLOC
) &&
1855 s
->sh_type
== SHT_RELX
) {
1856 relocate_rel(s1
, s
);
1862 /* Create an ELF file on disk.
1863 This function handle ELF specific layout requirements */
1864 static void tcc_output_elf(TCCState
*s1
, FILE *f
, int phnum
, ElfW(Phdr
) *phdr
,
1865 int file_offset
, int *sec_order
)
1867 int i
, shnum
, offset
, size
, file_type
;
1870 ElfW(Shdr
) shdr
, *sh
;
1872 file_type
= s1
->output_type
;
1873 shnum
= s1
->nb_sections
;
1875 memset(&ehdr
, 0, sizeof(ehdr
));
1878 ehdr
.e_phentsize
= sizeof(ElfW(Phdr
));
1879 ehdr
.e_phnum
= phnum
;
1880 ehdr
.e_phoff
= sizeof(ElfW(Ehdr
));
1884 file_offset
= (file_offset
+ 3) & -4;
1887 ehdr
.e_ident
[0] = ELFMAG0
;
1888 ehdr
.e_ident
[1] = ELFMAG1
;
1889 ehdr
.e_ident
[2] = ELFMAG2
;
1890 ehdr
.e_ident
[3] = ELFMAG3
;
1891 ehdr
.e_ident
[4] = ELFCLASSW
;
1892 ehdr
.e_ident
[5] = ELFDATA2LSB
;
1893 ehdr
.e_ident
[6] = EV_CURRENT
;
1894 #if !defined(TCC_TARGET_PE) && (defined(__FreeBSD__) || defined(__FreeBSD_kernel__))
1895 /* FIXME: should set only for freebsd _target_, but we exclude only PE target */
1896 ehdr
.e_ident
[EI_OSABI
] = ELFOSABI_FREEBSD
;
1898 #ifdef TCC_TARGET_ARM
1900 ehdr
.e_ident
[EI_OSABI
] = 0;
1901 ehdr
.e_flags
= EF_ARM_EABI_VER4
;
1902 if (file_type
== TCC_OUTPUT_EXE
|| file_type
== TCC_OUTPUT_DLL
)
1903 ehdr
.e_flags
|= EF_ARM_HASENTRY
;
1904 if (s1
->float_abi
== ARM_HARD_FLOAT
)
1905 ehdr
.e_flags
|= EF_ARM_VFP_FLOAT
;
1907 ehdr
.e_flags
|= EF_ARM_SOFT_FLOAT
;
1909 ehdr
.e_ident
[EI_OSABI
] = ELFOSABI_ARM
;
1914 case TCC_OUTPUT_EXE
:
1915 ehdr
.e_type
= ET_EXEC
;
1916 ehdr
.e_entry
= get_elf_sym_addr(s1
, "_start", 1);
1918 case TCC_OUTPUT_DLL
:
1919 ehdr
.e_type
= ET_DYN
;
1920 ehdr
.e_entry
= text_section
->sh_addr
; /* XXX: is it correct ? */
1922 case TCC_OUTPUT_OBJ
:
1923 ehdr
.e_type
= ET_REL
;
1926 ehdr
.e_machine
= EM_TCC_TARGET
;
1927 ehdr
.e_version
= EV_CURRENT
;
1928 ehdr
.e_shoff
= file_offset
;
1929 ehdr
.e_ehsize
= sizeof(ElfW(Ehdr
));
1930 ehdr
.e_shentsize
= sizeof(ElfW(Shdr
));
1931 ehdr
.e_shnum
= shnum
;
1932 ehdr
.e_shstrndx
= shnum
- 1;
1934 fwrite(&ehdr
, 1, sizeof(ElfW(Ehdr
)), f
);
1935 fwrite(phdr
, 1, phnum
* sizeof(ElfW(Phdr
)), f
);
1936 offset
= sizeof(ElfW(Ehdr
)) + phnum
* sizeof(ElfW(Phdr
));
1938 sort_syms(s1
, symtab_section
);
1939 for(i
= 1; i
< s1
->nb_sections
; i
++) {
1940 s
= s1
->sections
[sec_order
[i
]];
1941 if (s
->sh_type
!= SHT_NOBITS
) {
1942 while (offset
< s
->sh_offset
) {
1948 fwrite(s
->data
, 1, size
, f
);
1953 /* output section headers */
1954 while (offset
< ehdr
.e_shoff
) {
1959 for(i
= 0; i
< s1
->nb_sections
; i
++) {
1961 memset(sh
, 0, sizeof(ElfW(Shdr
)));
1962 s
= s1
->sections
[i
];
1964 sh
->sh_name
= s
->sh_name
;
1965 sh
->sh_type
= s
->sh_type
;
1966 sh
->sh_flags
= s
->sh_flags
;
1967 sh
->sh_entsize
= s
->sh_entsize
;
1968 sh
->sh_info
= s
->sh_info
;
1970 sh
->sh_link
= s
->link
->sh_num
;
1971 sh
->sh_addralign
= s
->sh_addralign
;
1972 sh
->sh_addr
= s
->sh_addr
;
1973 sh
->sh_offset
= s
->sh_offset
;
1974 sh
->sh_size
= s
->sh_size
;
1976 fwrite(sh
, 1, sizeof(ElfW(Shdr
)), f
);
1980 /* Write an elf, coff or "binary" file */
1981 static int tcc_write_elf_file(TCCState
*s1
, const char *filename
, int phnum
,
1982 ElfW(Phdr
) *phdr
, int file_offset
, int *sec_order
)
1984 int fd
, mode
, file_type
;
1987 file_type
= s1
->output_type
;
1988 if (file_type
== TCC_OUTPUT_OBJ
)
1993 fd
= open(filename
, O_WRONLY
| O_CREAT
| O_TRUNC
| O_BINARY
, mode
);
1995 tcc_error_noabort("could not write '%s'", filename
);
1998 f
= fdopen(fd
, "wb");
2000 printf("<- %s\n", filename
);
2002 #ifdef TCC_TARGET_COFF
2003 if (s1
->output_format
== TCC_OUTPUT_FORMAT_COFF
)
2004 tcc_output_coff(s1
, f
);
2007 if (s1
->output_format
== TCC_OUTPUT_FORMAT_ELF
)
2008 tcc_output_elf(s1
, f
, phnum
, phdr
, file_offset
, sec_order
);
2010 tcc_output_binary(s1
, f
, sec_order
);
2016 /* Sort section headers by assigned sh_addr, remove sections
2017 that we aren't going to output. */
2018 static void tidy_section_headers(TCCState
*s1
, int *sec_order
)
2020 int i
, nnew
, l
, *backmap
;
2024 snew
= tcc_malloc(s1
->nb_sections
* sizeof(snew
[0]));
2025 backmap
= tcc_malloc(s1
->nb_sections
* sizeof(backmap
[0]));
2026 for (i
= 0, nnew
= 0, l
= s1
->nb_sections
; i
< s1
->nb_sections
; i
++) {
2027 s
= s1
->sections
[sec_order
[i
]];
2028 if (!i
|| s
->sh_name
) {
2029 backmap
[sec_order
[i
]] = nnew
;
2033 backmap
[sec_order
[i
]] = 0;
2037 for (i
= 0; i
< nnew
; i
++) {
2041 if (s
->sh_type
== SHT_RELX
)
2042 s
->sh_info
= backmap
[s
->sh_info
];
2046 for_each_elem(symtab_section
, 1, sym
, ElfW(Sym
))
2047 if (sym
->st_shndx
!= SHN_UNDEF
&& sym
->st_shndx
< SHN_LORESERVE
)
2048 sym
->st_shndx
= backmap
[sym
->st_shndx
];
2049 if( !s1
->static_link
) {
2050 for_each_elem(s1
->dynsym
, 1, sym
, ElfW(Sym
))
2051 if (sym
->st_shndx
!= SHN_UNDEF
&& sym
->st_shndx
< SHN_LORESERVE
)
2052 sym
->st_shndx
= backmap
[sym
->st_shndx
];
2054 for (i
= 0; i
< s1
->nb_sections
; i
++)
2056 tcc_free(s1
->sections
);
2057 s1
->sections
= snew
;
2058 s1
->nb_sections
= nnew
;
2062 /* Output an elf, coff or binary file */
2063 /* XXX: suppress unneeded sections */
2064 static int elf_output_file(TCCState
*s1
, const char *filename
)
2066 int i
, ret
, phnum
, shnum
, file_type
, file_offset
, *sec_order
;
2067 struct dyn_inf dyninf
= {0};
2070 Section
*strsec
, *interp
, *dynamic
, *dynstr
;
2073 file_type
= s1
->output_type
;
2078 interp
= dynamic
= dynstr
= NULL
; /* avoid warning */
2081 if (file_type
!= TCC_OUTPUT_OBJ
) {
2082 /* if linking, also link in runtime libraries (libc, libgcc, etc.) */
2083 tcc_add_runtime(s1
);
2084 resolve_common_syms(s1
);
2086 if (!s1
->static_link
) {
2087 if (file_type
== TCC_OUTPUT_EXE
) {
2089 /* allow override the dynamic loader */
2090 const char *elfint
= getenv("LD_SO");
2092 elfint
= DEFAULT_ELFINTERP(s1
);
2093 /* add interpreter section only if executable */
2094 interp
= new_section(s1
, ".interp", SHT_PROGBITS
, SHF_ALLOC
);
2095 interp
->sh_addralign
= 1;
2096 ptr
= section_ptr_add(interp
, 1 + strlen(elfint
));
2097 strcpy(ptr
, elfint
);
2100 /* add dynamic symbol table */
2101 s1
->dynsym
= new_symtab(s1
, ".dynsym", SHT_DYNSYM
, SHF_ALLOC
,
2103 ".hash", SHF_ALLOC
);
2104 dynstr
= s1
->dynsym
->link
;
2106 /* add dynamic section */
2107 dynamic
= new_section(s1
, ".dynamic", SHT_DYNAMIC
,
2108 SHF_ALLOC
| SHF_WRITE
);
2109 dynamic
->link
= dynstr
;
2110 dynamic
->sh_entsize
= sizeof(ElfW(Dyn
));
2114 if (file_type
== TCC_OUTPUT_EXE
) {
2115 bind_exe_dynsyms(s1
);
2118 bind_libs_dynsyms(s1
);
2120 /* shared library case: simply export all global symbols */
2121 export_global_syms(s1
);
2124 build_got_entries(s1
);
2127 /* we add a section for symbols */
2128 strsec
= new_section(s1
, ".shstrtab", SHT_STRTAB
, 0);
2129 put_elf_str(strsec
, "");
2131 /* Allocate strings for section names */
2132 textrel
= alloc_sec_names(s1
, file_type
, strsec
);
2135 /* add a list of needed dlls */
2136 for(i
= 0; i
< s1
->nb_loaded_dlls
; i
++) {
2137 DLLReference
*dllref
= s1
->loaded_dlls
[i
];
2138 if (dllref
->level
== 0)
2139 put_dt(dynamic
, DT_NEEDED
, put_elf_str(dynstr
, dllref
->name
));
2143 put_dt(dynamic
, s1
->enable_new_dtags
? DT_RUNPATH
: DT_RPATH
,
2144 put_elf_str(dynstr
, s1
->rpath
));
2146 if (file_type
== TCC_OUTPUT_DLL
) {
2148 put_dt(dynamic
, DT_SONAME
, put_elf_str(dynstr
, s1
->soname
));
2149 /* XXX: currently, since we do not handle PIC code, we
2150 must relocate the readonly segments */
2152 put_dt(dynamic
, DT_TEXTREL
, 0);
2156 put_dt(dynamic
, DT_SYMBOLIC
, 0);
2158 dyninf
.dynamic
= dynamic
;
2159 dyninf
.dynstr
= dynstr
;
2160 /* remember offset and reserve space for 2nd call below */
2161 dyninf
.data_offset
= dynamic
->data_offset
;
2162 fill_dynamic(s1
, &dyninf
);
2163 dynamic
->sh_size
= dynamic
->data_offset
;
2164 dynstr
->sh_size
= dynstr
->data_offset
;
2167 /* compute number of program headers */
2168 if (file_type
== TCC_OUTPUT_OBJ
)
2170 else if (file_type
== TCC_OUTPUT_DLL
)
2172 else if (s1
->static_link
)
2177 /* allocate program segment headers */
2178 phdr
= tcc_mallocz(phnum
* sizeof(ElfW(Phdr
)));
2180 /* compute number of sections */
2181 shnum
= s1
->nb_sections
;
2183 /* this array is used to reorder sections in the output file */
2184 sec_order
= tcc_malloc(sizeof(int) * shnum
);
2187 /* compute section to program header mapping */
2188 file_offset
= layout_sections(s1
, phdr
, phnum
, interp
, strsec
, &dyninf
,
2191 /* Fill remaining program header and finalize relocation related to dynamic
2193 if (file_type
!= TCC_OUTPUT_OBJ
) {
2194 fill_unloadable_phdr(phdr
, phnum
, interp
, dynamic
);
2196 dynamic
->data_offset
= dyninf
.data_offset
;
2197 fill_dynamic(s1
, &dyninf
);
2199 /* put in GOT the dynamic section address and relocate PLT */
2200 write32le(s1
->got
->data
, dynamic
->sh_addr
);
2201 if (file_type
== TCC_OUTPUT_EXE
2202 || (RELOCATE_DLLPLT
&& file_type
== TCC_OUTPUT_DLL
))
2205 /* relocate symbols in .dynsym now that final addresses are known */
2206 for_each_elem(s1
->dynsym
, 1, sym
, ElfW(Sym
)) {
2207 if (sym
->st_shndx
!= SHN_UNDEF
&& sym
->st_shndx
< SHN_LORESERVE
) {
2208 /* do symbol relocation */
2209 sym
->st_value
+= s1
->sections
[sym
->st_shndx
]->sh_addr
;
2214 /* if building executable or DLL, then relocate each section
2215 except the GOT which is already relocated */
2216 ret
= final_sections_reloc(s1
);
2219 tidy_section_headers(s1
, sec_order
);
2221 /* Perform relocation to GOT or PLT entries */
2222 if (file_type
== TCC_OUTPUT_EXE
&& s1
->static_link
)
2225 fill_local_got_entries(s1
);
2228 /* Create the ELF file with name 'filename' */
2229 ret
= tcc_write_elf_file(s1
, filename
, phnum
, phdr
, file_offset
, sec_order
);
2230 s1
->nb_sections
= shnum
;
2232 tcc_free(sec_order
);
2237 LIBTCCAPI
int tcc_output_file(TCCState
*s
, const char *filename
)
2240 #ifdef TCC_TARGET_PE
2241 if (s
->output_type
!= TCC_OUTPUT_OBJ
) {
2242 ret
= pe_output_file(s
, filename
);
2245 ret
= elf_output_file(s
, filename
);
2249 ssize_t
full_read(int fd
, void *buf
, size_t count
) {
2253 ssize_t num
= read(fd
, cbuf
, count
-rnum
);
2254 if (num
< 0) return num
;
2255 if (num
== 0) return rnum
;
2261 static void *load_data(int fd
, unsigned long file_offset
, unsigned long size
)
2265 data
= tcc_malloc(size
);
2266 lseek(fd
, file_offset
, SEEK_SET
);
2267 full_read(fd
, data
, size
);
2271 typedef struct SectionMergeInfo
{
2272 Section
*s
; /* corresponding existing section */
2273 unsigned long offset
; /* offset of the new section in the existing section */
2274 unsigned long oldlen
; /* size of existing section before adding this one */
2275 uint8_t new_section
; /* true if section 's' was added */
2276 uint8_t link_once
; /* true if link once section */
2279 ST_FUNC
int tcc_object_type(int fd
, ElfW(Ehdr
) *h
)
2281 int size
= full_read(fd
, h
, sizeof *h
);
2282 if (size
== sizeof *h
&& 0 == memcmp(h
, ELFMAG
, 4)) {
2283 if (h
->e_type
== ET_REL
)
2284 return AFF_BINTYPE_REL
;
2285 if (h
->e_type
== ET_DYN
)
2286 return AFF_BINTYPE_DYN
;
2287 } else if (size
>= 8) {
2288 if (0 == memcmp(h
, ARMAG
, 8))
2289 return AFF_BINTYPE_AR
;
2290 #ifdef TCC_TARGET_COFF
2291 if (((struct filehdr
*)h
)->f_magic
== COFF_C67_MAGIC
)
2292 return AFF_BINTYPE_C67
;
2298 /* load an object file and merge it with current files */
2299 /* XXX: handle correctly stab (debug) info */
2300 ST_FUNC
int tcc_load_object_file(TCCState
*s1
,
2301 int fd
, unsigned long file_offset
)
2304 ElfW(Shdr
) *shdr
, *sh
;
2305 int size
, i
, j
, offset
, offseti
, nb_syms
, sym_index
, ret
, seencompressed
;
2306 unsigned char *strsec
, *strtab
;
2307 int *old_to_new_syms
;
2308 char *sh_name
, *name
;
2309 SectionMergeInfo
*sm_table
, *sm
;
2310 ElfW(Sym
) *sym
, *symtab
;
2317 stab_index
= stabstr_index
= 0;
2319 lseek(fd
, file_offset
, SEEK_SET
);
2320 if (tcc_object_type(fd
, &ehdr
) != AFF_BINTYPE_REL
)
2322 /* test CPU specific stuff */
2323 if (ehdr
.e_ident
[5] != ELFDATA2LSB
||
2324 ehdr
.e_machine
!= EM_TCC_TARGET
) {
2326 tcc_error_noabort("invalid object file");
2330 shdr
= load_data(fd
, file_offset
+ ehdr
.e_shoff
,
2331 sizeof(ElfW(Shdr
)) * ehdr
.e_shnum
);
2332 sm_table
= tcc_mallocz(sizeof(SectionMergeInfo
) * ehdr
.e_shnum
);
2334 /* load section names */
2335 sh
= &shdr
[ehdr
.e_shstrndx
];
2336 strsec
= load_data(fd
, file_offset
+ sh
->sh_offset
, sh
->sh_size
);
2338 /* load symtab and strtab */
2339 old_to_new_syms
= NULL
;
2344 for(i
= 1; i
< ehdr
.e_shnum
; i
++) {
2346 if (sh
->sh_type
== SHT_SYMTAB
) {
2348 tcc_error_noabort("object must contain only one symtab");
2353 nb_syms
= sh
->sh_size
/ sizeof(ElfW(Sym
));
2354 symtab
= load_data(fd
, file_offset
+ sh
->sh_offset
, sh
->sh_size
);
2355 sm_table
[i
].s
= symtab_section
;
2357 /* now load strtab */
2358 sh
= &shdr
[sh
->sh_link
];
2359 strtab
= load_data(fd
, file_offset
+ sh
->sh_offset
, sh
->sh_size
);
2361 if (sh
->sh_flags
& SHF_COMPRESSED
)
2365 /* now examine each section and try to merge its content with the
2367 for(i
= 1; i
< ehdr
.e_shnum
; i
++) {
2368 /* no need to examine section name strtab */
2369 if (i
== ehdr
.e_shstrndx
)
2372 sh_name
= (char *) strsec
+ sh
->sh_name
;
2373 /* ignore sections types we do not handle */
2374 if (sh
->sh_type
!= SHT_PROGBITS
&&
2375 sh
->sh_type
!= SHT_RELX
&&
2377 sh
->sh_type
!= SHT_ARM_EXIDX
&&
2379 sh
->sh_type
!= SHT_NOBITS
&&
2380 sh
->sh_type
!= SHT_PREINIT_ARRAY
&&
2381 sh
->sh_type
!= SHT_INIT_ARRAY
&&
2382 sh
->sh_type
!= SHT_FINI_ARRAY
&&
2383 strcmp(sh_name
, ".stabstr")
2387 && (!strncmp(sh_name
, ".debug_", sizeof(".debug_")-1)
2388 || (sh
->sh_type
== SHT_RELX
2389 && !strncmp((char*)strsec
+ shdr
[sh
->sh_info
].sh_name
,
2390 ".debug_", sizeof(".debug_")-1))))
2392 if (sh
->sh_addralign
< 1)
2393 sh
->sh_addralign
= 1;
2394 /* find corresponding section, if any */
2395 for(j
= 1; j
< s1
->nb_sections
;j
++) {
2396 s
= s1
->sections
[j
];
2397 if (!strcmp(s
->name
, sh_name
)) {
2398 if (!strncmp(sh_name
, ".gnu.linkonce",
2399 sizeof(".gnu.linkonce") - 1)) {
2400 /* if a 'linkonce' section is already present, we
2401 do not add it again. It is a little tricky as
2402 symbols can still be defined in
2404 sm_table
[i
].link_once
= 1;
2411 /* not found: create new section */
2412 s
= new_section(s1
, sh_name
, sh
->sh_type
, sh
->sh_flags
& ~SHF_GROUP
);
2413 /* take as much info as possible from the section. sh_link and
2414 sh_info will be updated later */
2415 s
->sh_addralign
= sh
->sh_addralign
;
2416 s
->sh_entsize
= sh
->sh_entsize
;
2417 sm_table
[i
].new_section
= 1;
2419 if (sh
->sh_type
!= s
->sh_type
) {
2420 tcc_error_noabort("invalid section type");
2424 /* align start of section */
2425 sm_table
[i
].oldlen
= s
->data_offset
;
2426 offset
= s
->data_offset
;
2428 if (0 == strcmp(sh_name
, ".stab")) {
2432 if (0 == strcmp(sh_name
, ".stabstr")) {
2437 size
= sh
->sh_addralign
- 1;
2438 offset
= (offset
+ size
) & ~size
;
2439 if (sh
->sh_addralign
> s
->sh_addralign
)
2440 s
->sh_addralign
= sh
->sh_addralign
;
2441 s
->data_offset
= offset
;
2443 sm_table
[i
].offset
= offset
;
2445 /* concatenate sections */
2447 if (sh
->sh_type
!= SHT_NOBITS
) {
2449 lseek(fd
, file_offset
+ sh
->sh_offset
, SEEK_SET
);
2450 ptr
= section_ptr_add(s
, size
);
2451 full_read(fd
, ptr
, size
);
2453 s
->data_offset
+= size
;
2458 /* gr relocate stab strings */
2459 if (stab_index
&& stabstr_index
) {
2462 s
= sm_table
[stab_index
].s
;
2463 a
= (Stab_Sym
*)(s
->data
+ sm_table
[stab_index
].offset
);
2464 b
= (Stab_Sym
*)(s
->data
+ s
->data_offset
);
2465 o
= sm_table
[stabstr_index
].offset
;
2473 /* second short pass to update sh_link and sh_info fields of new
2475 for(i
= 1; i
< ehdr
.e_shnum
; i
++) {
2477 if (!s
|| !sm_table
[i
].new_section
)
2480 if (sh
->sh_link
> 0)
2481 s
->link
= sm_table
[sh
->sh_link
].s
;
2482 if (sh
->sh_type
== SHT_RELX
) {
2483 if (sm_table
[sh
->sh_info
].s
) {
2484 s
->sh_info
= sm_table
[sh
->sh_info
].s
->sh_num
;
2485 /* update backward link */
2486 s1
->sections
[s
->sh_info
]->reloc
= s
;
2488 /* we haven't read the target of relocs, so cancel them */
2489 s
->data_offset
= sm_table
[i
].oldlen
;
2490 sm_table
[i
].s
= NULL
;
2496 /* resolve symbols */
2497 old_to_new_syms
= tcc_mallocz(nb_syms
* sizeof(int));
2500 for(i
= 1; i
< nb_syms
; i
++, sym
++) {
2501 if (sym
->st_shndx
!= SHN_UNDEF
&&
2502 sym
->st_shndx
< SHN_LORESERVE
) {
2503 sm
= &sm_table
[sym
->st_shndx
];
2504 if (sm
->link_once
) {
2505 /* if a symbol is in a link once section, we use the
2506 already defined symbol. It is very important to get
2507 correct relocations */
2508 if (ELFW(ST_BIND
)(sym
->st_info
) != STB_LOCAL
) {
2509 name
= (char *) strtab
+ sym
->st_name
;
2510 sym_index
= find_elf_sym(symtab_section
, name
);
2512 old_to_new_syms
[i
] = sym_index
;
2516 /* if no corresponding section added, no need to add symbol */
2519 /* convert section number */
2520 sym
->st_shndx
= sm
->s
->sh_num
;
2522 sym
->st_value
+= sm
->offset
;
2525 name
= (char *) strtab
+ sym
->st_name
;
2526 sym_index
= set_elf_sym(symtab_section
, sym
->st_value
, sym
->st_size
,
2527 sym
->st_info
, sym
->st_other
,
2528 sym
->st_shndx
, name
);
2529 old_to_new_syms
[i
] = sym_index
;
2532 /* third pass to patch relocation entries */
2533 for(i
= 1; i
< ehdr
.e_shnum
; i
++) {
2538 offset
= sm_table
[i
].offset
;
2539 switch(s
->sh_type
) {
2541 /* take relocation offset information */
2542 offseti
= sm_table
[sh
->sh_info
].offset
;
2543 for_each_elem(s
, (offset
/ sizeof(*rel
)), rel
, ElfW_Rel
) {
2546 /* convert symbol index */
2547 type
= ELFW(R_TYPE
)(rel
->r_info
);
2548 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
2549 /* NOTE: only one symtab assumed */
2550 if (sym_index
>= nb_syms
)
2552 sym_index
= old_to_new_syms
[sym_index
];
2553 /* ignore link_once in rel section. */
2554 if (!sym_index
&& !sm
->link_once
2555 #ifdef TCC_TARGET_ARM
2556 && type
!= R_ARM_V4BX
2560 tcc_error_noabort("Invalid relocation entry [%2d] '%s' @ %.8x",
2561 i
, strsec
+ sh
->sh_name
, rel
->r_offset
);
2564 rel
->r_info
= ELFW(R_INFO
)(sym_index
, type
);
2565 /* offset the relocation offset */
2566 rel
->r_offset
+= offseti
;
2567 #ifdef TCC_TARGET_ARM
2568 /* Jumps and branches from a Thumb code to a PLT entry need
2569 special handling since PLT entries are ARM code.
2570 Unconditional bl instructions referencing PLT entries are
2571 handled by converting these instructions into blx
2572 instructions. Other case of instructions referencing a PLT
2573 entry require to add a Thumb stub before the PLT entry to
2574 switch to ARM mode. We set bit plt_thumb_stub of the
2575 attribute of a symbol to indicate such a case. */
2576 if (type
== R_ARM_THM_JUMP24
)
2577 get_sym_attr(s1
, sym_index
, 1)->plt_thumb_stub
= 1;
2590 tcc_free(old_to_new_syms
);
2597 typedef struct ArchiveHeader
{
2598 char ar_name
[16]; /* name of this member */
2599 char ar_date
[12]; /* file mtime */
2600 char ar_uid
[6]; /* owner uid; printed as decimal */
2601 char ar_gid
[6]; /* owner gid; printed as decimal */
2602 char ar_mode
[8]; /* file mode, printed as octal */
2603 char ar_size
[10]; /* file size, printed as decimal */
2604 char ar_fmag
[2]; /* should contain ARFMAG */
2607 static int get_be32(const uint8_t *b
)
2609 return b
[3] | (b
[2] << 8) | (b
[1] << 16) | (b
[0] << 24);
2612 static long get_be64(const uint8_t *b
)
2614 long long ret
= get_be32(b
);
2615 ret
= (ret
<< 32) | (unsigned)get_be32(b
+4);
2619 /* load only the objects which resolve undefined symbols */
2620 static int tcc_load_alacarte(TCCState
*s1
, int fd
, int size
, int entrysize
)
2622 long i
, bound
, nsyms
, sym_index
, off
, ret
;
2624 const char *ar_names
, *p
;
2625 const uint8_t *ar_index
;
2628 data
= tcc_malloc(size
);
2629 if (full_read(fd
, data
, size
) != size
)
2631 nsyms
= entrysize
== 4 ? get_be32(data
) : get_be64(data
);
2632 ar_index
= data
+ entrysize
;
2633 ar_names
= (char *) ar_index
+ nsyms
* entrysize
;
2637 for(p
= ar_names
, i
= 0; i
< nsyms
; i
++, p
+= strlen(p
)+1) {
2638 sym_index
= find_elf_sym(symtab_section
, p
);
2640 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
2641 if(sym
->st_shndx
== SHN_UNDEF
) {
2642 off
= (entrysize
== 4
2643 ? get_be32(ar_index
+ i
* 4)
2644 : get_be64(ar_index
+ i
* 8))
2645 + sizeof(ArchiveHeader
);
2647 if(tcc_load_object_file(s1
, fd
, off
) < 0) {
2662 /* load a '.a' file */
2663 ST_FUNC
int tcc_load_archive(TCCState
*s1
, int fd
, int alacarte
)
2670 unsigned long file_offset
;
2672 /* skip magic which was already checked */
2673 full_read(fd
, magic
, sizeof(magic
));
2676 len
= full_read(fd
, &hdr
, sizeof(hdr
));
2679 if (len
!= sizeof(hdr
)) {
2680 tcc_error_noabort("invalid archive");
2683 memcpy(ar_size
, hdr
.ar_size
, sizeof(hdr
.ar_size
));
2684 ar_size
[sizeof(hdr
.ar_size
)] = '\0';
2685 size
= strtol(ar_size
, NULL
, 0);
2686 memcpy(ar_name
, hdr
.ar_name
, sizeof(hdr
.ar_name
));
2687 for(i
= sizeof(hdr
.ar_name
) - 1; i
>= 0; i
--) {
2688 if (ar_name
[i
] != ' ')
2691 ar_name
[i
+ 1] = '\0';
2692 file_offset
= lseek(fd
, 0, SEEK_CUR
);
2694 size
= (size
+ 1) & ~1;
2695 if (!strcmp(ar_name
, "/")) {
2696 /* coff symbol table : we handle it */
2698 return tcc_load_alacarte(s1
, fd
, size
, 4);
2699 } else if (!strcmp(ar_name
, "/SYM64/")) {
2701 return tcc_load_alacarte(s1
, fd
, size
, 8);
2704 if (tcc_object_type(fd
, &ehdr
) == AFF_BINTYPE_REL
) {
2705 if (tcc_load_object_file(s1
, fd
, file_offset
) < 0)
2709 lseek(fd
, file_offset
+ size
, SEEK_SET
);
2714 #ifndef TCC_TARGET_PE
2715 /* load a DLL and all referenced DLLs. 'level = 0' means that the DLL
2716 is referenced by the user (so it should be added as DT_NEEDED in
2717 the generated ELF file) */
2718 ST_FUNC
int tcc_load_dll(TCCState
*s1
, int fd
, const char *filename
, int level
)
2721 ElfW(Shdr
) *shdr
, *sh
, *sh1
;
2722 int i
, j
, nb_syms
, nb_dts
, sym_bind
, ret
;
2723 ElfW(Sym
) *sym
, *dynsym
;
2724 ElfW(Dyn
) *dt
, *dynamic
;
2725 unsigned char *dynstr
;
2726 const char *name
, *soname
;
2727 DLLReference
*dllref
;
2729 full_read(fd
, &ehdr
, sizeof(ehdr
));
2731 /* test CPU specific stuff */
2732 if (ehdr
.e_ident
[5] != ELFDATA2LSB
||
2733 ehdr
.e_machine
!= EM_TCC_TARGET
) {
2734 tcc_error_noabort("bad architecture");
2739 shdr
= load_data(fd
, ehdr
.e_shoff
, sizeof(ElfW(Shdr
)) * ehdr
.e_shnum
);
2741 /* load dynamic section and dynamic symbols */
2745 dynsym
= NULL
; /* avoid warning */
2746 dynstr
= NULL
; /* avoid warning */
2747 for(i
= 0, sh
= shdr
; i
< ehdr
.e_shnum
; i
++, sh
++) {
2748 switch(sh
->sh_type
) {
2750 nb_dts
= sh
->sh_size
/ sizeof(ElfW(Dyn
));
2751 dynamic
= load_data(fd
, sh
->sh_offset
, sh
->sh_size
);
2754 nb_syms
= sh
->sh_size
/ sizeof(ElfW(Sym
));
2755 dynsym
= load_data(fd
, sh
->sh_offset
, sh
->sh_size
);
2756 sh1
= &shdr
[sh
->sh_link
];
2757 dynstr
= load_data(fd
, sh1
->sh_offset
, sh1
->sh_size
);
2764 /* compute the real library name */
2765 soname
= tcc_basename(filename
);
2767 for(i
= 0, dt
= dynamic
; i
< nb_dts
; i
++, dt
++) {
2768 if (dt
->d_tag
== DT_SONAME
) {
2769 soname
= (char *) dynstr
+ dt
->d_un
.d_val
;
2773 /* if the dll is already loaded, do not load it */
2774 for(i
= 0; i
< s1
->nb_loaded_dlls
; i
++) {
2775 dllref
= s1
->loaded_dlls
[i
];
2776 if (!strcmp(soname
, dllref
->name
)) {
2777 /* but update level if needed */
2778 if (level
< dllref
->level
)
2779 dllref
->level
= level
;
2785 /* add the dll and its level */
2786 dllref
= tcc_mallocz(sizeof(DLLReference
) + strlen(soname
));
2787 dllref
->level
= level
;
2788 strcpy(dllref
->name
, soname
);
2789 dynarray_add(&s1
->loaded_dlls
, &s1
->nb_loaded_dlls
, dllref
);
2791 /* add dynamic symbols in dynsym_section */
2792 for(i
= 1, sym
= dynsym
+ 1; i
< nb_syms
; i
++, sym
++) {
2793 sym_bind
= ELFW(ST_BIND
)(sym
->st_info
);
2794 if (sym_bind
== STB_LOCAL
)
2796 name
= (char *) dynstr
+ sym
->st_name
;
2797 set_elf_sym(s1
->dynsymtab_section
, sym
->st_value
, sym
->st_size
,
2798 sym
->st_info
, sym
->st_other
, sym
->st_shndx
, name
);
2801 /* load all referenced DLLs */
2802 for(i
= 0, dt
= dynamic
; i
< nb_dts
; i
++, dt
++) {
2805 name
= (char *) dynstr
+ dt
->d_un
.d_val
;
2806 for(j
= 0; j
< s1
->nb_loaded_dlls
; j
++) {
2807 dllref
= s1
->loaded_dlls
[j
];
2808 if (!strcmp(name
, dllref
->name
))
2809 goto already_loaded
;
2811 if (tcc_add_dll(s1
, name
, AFF_REFERENCED_DLL
) < 0) {
2812 tcc_error_noabort("referenced dll '%s' not found", name
);
2829 #define LD_TOK_NAME 256
2830 #define LD_TOK_EOF (-1)
2832 /* return next ld script token */
2833 static int ld_next(TCCState
*s1
, char *name
, int name_size
)
2851 file
->buf_ptr
= parse_comment(file
->buf_ptr
);
2852 ch
= file
->buf_ptr
[0];
2865 /* case 'a' ... 'z': */
2892 /* case 'A' ... 'z': */
2926 if (!((ch
>= 'a' && ch
<= 'z') ||
2927 (ch
>= 'A' && ch
<= 'Z') ||
2928 (ch
>= '0' && ch
<= '9') ||
2929 strchr("/.-_+=$:\\,~", ch
)))
2931 if ((q
- name
) < name_size
- 1) {
2950 static int ld_add_file(TCCState
*s1
, const char filename
[])
2952 if (filename
[0] == '/') {
2953 if (CONFIG_SYSROOT
[0] == '\0'
2954 && tcc_add_file_internal(s1
, filename
, AFF_TYPE_BIN
) == 0)
2956 filename
= tcc_basename(filename
);
2958 return tcc_add_dll(s1
, filename
, 0);
2961 static inline int new_undef_syms(void)
2964 ret
= new_undef_sym
;
2969 static int ld_add_file_list(TCCState
*s1
, const char *cmd
, int as_needed
)
2971 char filename
[1024], libname
[1024];
2972 int t
, group
, nblibs
= 0, ret
= 0;
2975 group
= !strcmp(cmd
, "GROUP");
2978 t
= ld_next(s1
, filename
, sizeof(filename
));
2981 t
= ld_next(s1
, filename
, sizeof(filename
));
2984 if (t
== LD_TOK_EOF
) {
2985 tcc_error_noabort("unexpected end of file");
2987 goto lib_parse_error
;
2988 } else if (t
== ')') {
2990 } else if (t
== '-') {
2991 t
= ld_next(s1
, filename
, sizeof(filename
));
2992 if ((t
!= LD_TOK_NAME
) || (filename
[0] != 'l')) {
2993 tcc_error_noabort("library name expected");
2995 goto lib_parse_error
;
2997 pstrcpy(libname
, sizeof libname
, &filename
[1]);
2998 if (s1
->static_link
) {
2999 snprintf(filename
, sizeof filename
, "lib%s.a", libname
);
3001 snprintf(filename
, sizeof filename
, "lib%s.so", libname
);
3003 } else if (t
!= LD_TOK_NAME
) {
3004 tcc_error_noabort("filename expected");
3006 goto lib_parse_error
;
3008 if (!strcmp(filename
, "AS_NEEDED")) {
3009 ret
= ld_add_file_list(s1
, cmd
, 1);
3011 goto lib_parse_error
;
3013 /* TODO: Implement AS_NEEDED support. Ignore it for now */
3015 ret
= ld_add_file(s1
, filename
);
3017 goto lib_parse_error
;
3019 /* Add the filename *and* the libname to avoid future conversions */
3020 dynarray_add(&libs
, &nblibs
, tcc_strdup(filename
));
3021 if (libname
[0] != '\0')
3022 dynarray_add(&libs
, &nblibs
, tcc_strdup(libname
));
3026 t
= ld_next(s1
, filename
, sizeof(filename
));
3028 t
= ld_next(s1
, filename
, sizeof(filename
));
3031 if (group
&& !as_needed
) {
3032 while (new_undef_syms()) {
3035 for (i
= 0; i
< nblibs
; i
++)
3036 ld_add_file(s1
, libs
[i
]);
3040 dynarray_reset(&libs
, &nblibs
);
3044 /* interpret a subset of GNU ldscripts to handle the dummy libc.so
3046 ST_FUNC
int tcc_load_ldscript(TCCState
*s1
)
3049 char filename
[1024];
3054 t
= ld_next(s1
, cmd
, sizeof(cmd
));
3055 if (t
== LD_TOK_EOF
)
3057 else if (t
!= LD_TOK_NAME
)
3059 if (!strcmp(cmd
, "INPUT") ||
3060 !strcmp(cmd
, "GROUP")) {
3061 ret
= ld_add_file_list(s1
, cmd
, 0);
3064 } else if (!strcmp(cmd
, "OUTPUT_FORMAT") ||
3065 !strcmp(cmd
, "TARGET")) {
3066 /* ignore some commands */
3067 t
= ld_next(s1
, cmd
, sizeof(cmd
));
3071 t
= ld_next(s1
, filename
, sizeof(filename
));
3072 if (t
== LD_TOK_EOF
) {
3073 tcc_error_noabort("unexpected end of file");
3075 } else if (t
== ')') {
3085 #endif /* !TCC_TARGET_PE */