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 /* XXX: avoid static variable */
24 static int new_undef_sym
= 0; /* Is there a new undefined sym since last new_undef_sym() */
26 ST_FUNC
int put_elf_str(Section
*s
, const char *sym
)
31 len
= strlen(sym
) + 1;
32 offset
= s
->data_offset
;
33 ptr
= section_ptr_add(s
, len
);
34 memcpy(ptr
, sym
, len
);
38 /* elf symbol hashing function */
39 static unsigned long elf_hash(const unsigned char *name
)
41 unsigned long h
= 0, g
;
44 h
= (h
<< 4) + *name
++;
53 /* rebuild hash table of section s */
54 /* NOTE: we do factorize the hash table code to go faster */
55 static void rebuild_hash(Section
*s
, unsigned int nb_buckets
)
58 int *ptr
, *hash
, nb_syms
, sym_index
, h
;
59 unsigned char *strtab
;
61 strtab
= s
->link
->data
;
62 nb_syms
= s
->data_offset
/ sizeof(ElfW(Sym
));
64 s
->hash
->data_offset
= 0;
65 ptr
= section_ptr_add(s
->hash
, (2 + nb_buckets
+ nb_syms
) * sizeof(int));
70 memset(hash
, 0, (nb_buckets
+ 1) * sizeof(int));
71 ptr
+= nb_buckets
+ 1;
73 sym
= (ElfW(Sym
) *)s
->data
+ 1;
74 for(sym_index
= 1; sym_index
< nb_syms
; sym_index
++) {
75 if (ELFW(ST_BIND
)(sym
->st_info
) != STB_LOCAL
) {
76 h
= elf_hash(strtab
+ sym
->st_name
) % nb_buckets
;
87 /* return the symbol number */
88 ST_FUNC
int put_elf_sym(Section
*s
, addr_t value
, unsigned long size
,
89 int info
, int other
, int shndx
, const char *name
)
91 int name_offset
, sym_index
;
96 sym
= section_ptr_add(s
, sizeof(ElfW(Sym
)));
98 name_offset
= put_elf_str(s
->link
, name
);
101 /* XXX: endianness */
102 sym
->st_name
= name_offset
;
103 sym
->st_value
= value
;
106 sym
->st_other
= other
;
107 sym
->st_shndx
= shndx
;
108 sym_index
= sym
- (ElfW(Sym
) *)s
->data
;
112 ptr
= section_ptr_add(hs
, sizeof(int));
113 base
= (int *)hs
->data
;
114 /* only add global or weak symbols */
115 if (ELFW(ST_BIND
)(info
) != STB_LOCAL
) {
116 /* add another hashing entry */
118 h
= elf_hash((unsigned char *) name
) % nbuckets
;
120 base
[2 + h
] = sym_index
;
122 /* we resize the hash table */
123 hs
->nb_hashed_syms
++;
124 if (hs
->nb_hashed_syms
> 2 * nbuckets
) {
125 rebuild_hash(s
, 2 * nbuckets
);
135 /* find global ELF symbol 'name' and return its index. Return 0 if not
137 ST_FUNC
int find_elf_sym(Section
*s
, const char *name
)
141 int nbuckets
, sym_index
, h
;
147 nbuckets
= ((int *)hs
->data
)[0];
148 h
= elf_hash((unsigned char *) name
) % nbuckets
;
149 sym_index
= ((int *)hs
->data
)[2 + h
];
150 while (sym_index
!= 0) {
151 sym
= &((ElfW(Sym
) *)s
->data
)[sym_index
];
152 name1
= (char *) s
->link
->data
+ sym
->st_name
;
153 if (!strcmp(name
, name1
))
155 sym_index
= ((int *)hs
->data
)[2 + nbuckets
+ sym_index
];
160 /* return elf symbol value, signal error if 'err' is nonzero */
161 ST_FUNC addr_t
get_elf_sym_addr(TCCState
*s
, const char *name
, int err
)
166 sym_index
= find_elf_sym(s
->symtab
, name
);
167 sym
= &((ElfW(Sym
) *)s
->symtab
->data
)[sym_index
];
168 if (!sym_index
|| sym
->st_shndx
== SHN_UNDEF
) {
170 tcc_error("%s not defined", name
);
173 return sym
->st_value
;
176 /* return elf symbol value */
177 LIBTCCAPI
void *tcc_get_symbol(TCCState
*s
, const char *name
)
179 return (void*)(uintptr_t)get_elf_sym_addr(s
, name
, 0);
182 #if defined TCC_IS_NATIVE || defined TCC_TARGET_PE
183 /* return elf symbol value or error */
184 ST_FUNC
void* tcc_get_symbol_err(TCCState
*s
, const char *name
)
186 return (void*)(uintptr_t)get_elf_sym_addr(s
, name
, 1);
190 /* add an elf symbol : check if it is already defined and patch
191 it. Return symbol index. NOTE that sh_num can be SHN_UNDEF. */
192 ST_FUNC
int add_elf_sym(Section
*s
, addr_t value
, unsigned long size
,
193 int info
, int other
, int sh_num
, const char *name
)
196 int sym_bind
, sym_index
, sym_type
, esym_bind
;
197 unsigned char sym_vis
, esym_vis
, new_vis
;
199 sym_bind
= ELFW(ST_BIND
)(info
);
200 sym_type
= ELFW(ST_TYPE
)(info
);
201 sym_vis
= ELFW(ST_VISIBILITY
)(other
);
203 if (sym_bind
!= STB_LOCAL
) {
204 /* we search global or weak symbols */
205 sym_index
= find_elf_sym(s
, name
);
208 esym
= &((ElfW(Sym
) *)s
->data
)[sym_index
];
209 if (esym
->st_shndx
!= SHN_UNDEF
) {
210 esym_bind
= ELFW(ST_BIND
)(esym
->st_info
);
211 /* propagate the most constraining visibility */
212 /* STV_DEFAULT(0)<STV_PROTECTED(3)<STV_HIDDEN(2)<STV_INTERNAL(1) */
213 esym_vis
= ELFW(ST_VISIBILITY
)(esym
->st_other
);
214 if (esym_vis
== STV_DEFAULT
) {
216 } else if (sym_vis
== STV_DEFAULT
) {
219 new_vis
= (esym_vis
< sym_vis
) ? esym_vis
: sym_vis
;
221 esym
->st_other
= (esym
->st_other
& ~ELFW(ST_VISIBILITY
)(-1))
223 other
= esym
->st_other
; /* in case we have to patch esym */
224 if (sh_num
== SHN_UNDEF
) {
225 /* ignore adding of undefined symbol if the
226 corresponding symbol is already defined */
227 } else if (sym_bind
== STB_GLOBAL
&& esym_bind
== STB_WEAK
) {
228 /* global overrides weak, so patch */
230 } else if (sym_bind
== STB_WEAK
&& esym_bind
== STB_GLOBAL
) {
231 /* weak is ignored if already global */
232 } else if (sym_bind
== STB_WEAK
&& esym_bind
== STB_WEAK
) {
233 /* keep first-found weak definition, ignore subsequents */
234 } else if (sym_vis
== STV_HIDDEN
|| sym_vis
== STV_INTERNAL
) {
235 /* ignore hidden symbols after */
236 } else if (esym
->st_shndx
== SHN_COMMON
237 && (sh_num
< SHN_LORESERVE
|| sh_num
== SHN_COMMON
)) {
238 /* gr: Happens with 'tcc ... -static tcctest.c' on e.g. Ubuntu 6.01
239 No idea if this is the correct solution ... */
241 } else if (s
== tcc_state
->dynsymtab_section
) {
242 /* we accept that two DLL define the same symbol */
245 printf("new_bind=%x new_shndx=%x new_vis=%x old_bind=%x old_shndx=%x old_vis=%x\n",
246 sym_bind
, sh_num
, new_vis
, esym_bind
, esym
->st_shndx
, esym_vis
);
248 tcc_error_noabort("'%s' defined twice", name
);
252 esym
->st_info
= ELFW(ST_INFO
)(sym_bind
, sym_type
);
253 esym
->st_shndx
= sh_num
;
255 esym
->st_value
= value
;
256 esym
->st_size
= size
;
257 esym
->st_other
= other
;
261 sym_index
= put_elf_sym(s
, value
, size
,
262 ELFW(ST_INFO
)(sym_bind
, sym_type
), other
,
269 ST_FUNC
void put_elf_reloc(Section
*symtab
, Section
*s
, unsigned long offset
,
270 int type
, int symbol
)
278 /* if no relocation section, create it */
279 snprintf(buf
, sizeof(buf
), REL_SECTION_FMT
, s
->name
);
280 /* if the symtab is allocated, then we consider the relocation
282 sr
= new_section(tcc_state
, buf
, SHT_RELX
, symtab
->sh_flags
);
283 sr
->sh_entsize
= sizeof(ElfW_Rel
);
285 sr
->sh_info
= s
->sh_num
;
288 rel
= section_ptr_add(sr
, sizeof(ElfW_Rel
));
289 rel
->r_offset
= offset
;
290 rel
->r_info
= ELFW(R_INFO
)(symbol
, type
);
291 #ifdef TCC_TARGET_X86_64
296 /* put stab debug information */
298 ST_FUNC
void put_stabs(const char *str
, int type
, int other
, int desc
,
303 sym
= section_ptr_add(stab_section
, sizeof(Stab_Sym
));
305 sym
->n_strx
= put_elf_str(stabstr_section
, str
);
310 sym
->n_other
= other
;
312 sym
->n_value
= value
;
315 ST_FUNC
void put_stabs_r(const char *str
, int type
, int other
, int desc
,
316 unsigned long value
, Section
*sec
, int sym_index
)
318 put_stabs(str
, type
, other
, desc
, value
);
319 put_elf_reloc(symtab_section
, stab_section
,
320 stab_section
->data_offset
- sizeof(unsigned int),
321 R_DATA_32
, sym_index
);
324 ST_FUNC
void put_stabn(int type
, int other
, int desc
, int value
)
326 put_stabs(NULL
, type
, other
, desc
, value
);
329 ST_FUNC
void put_stabd(int type
, int other
, int desc
)
331 put_stabs(NULL
, type
, other
, desc
, 0);
334 /* Browse each elem of type <type> in section <sec> starting at elem <startoff>
335 using variable <elem> */
336 #define for_each_elem(sec, startoff, elem, type) \
337 for (elem = (type *) sec->data + startoff; \
338 elem < (type *) (sec->data + sec->data_offset); elem++)
340 /* In an ELF file symbol table, the local symbols must appear below
341 the global and weak ones. Since TCC cannot sort it while generating
342 the code, we must do it after. All the relocation tables are also
343 modified to take into account the symbol table sorting */
344 static void sort_syms(TCCState
*s1
, Section
*s
)
346 int *old_to_new_syms
;
354 nb_syms
= s
->data_offset
/ sizeof(ElfW(Sym
));
355 new_syms
= tcc_malloc(nb_syms
* sizeof(ElfW(Sym
)));
356 old_to_new_syms
= tcc_malloc(nb_syms
* sizeof(int));
358 /* first pass for local symbols */
359 p
= (ElfW(Sym
) *)s
->data
;
361 for(i
= 0; i
< nb_syms
; i
++) {
362 if (ELFW(ST_BIND
)(p
->st_info
) == STB_LOCAL
) {
363 old_to_new_syms
[i
] = q
- new_syms
;
368 /* save the number of local symbols in section header */
369 s
->sh_info
= q
- new_syms
;
371 /* then second pass for non local symbols */
372 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
;
381 /* we copy the new symbols to the old */
382 memcpy(s
->data
, new_syms
, nb_syms
* sizeof(ElfW(Sym
)));
385 /* now we modify all the relocations */
386 for(i
= 1; i
< s1
->nb_sections
; i
++) {
387 sr
= s1
->sections
[i
];
388 if (sr
->sh_type
== SHT_RELX
&& sr
->link
== s
) {
389 for_each_elem(sr
, 0, rel
, ElfW_Rel
) {
390 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
391 type
= ELFW(R_TYPE
)(rel
->r_info
);
392 sym_index
= old_to_new_syms
[sym_index
];
393 rel
->r_info
= ELFW(R_INFO
)(sym_index
, type
);
398 tcc_free(old_to_new_syms
);
401 /* relocate common symbols in the .bss section */
402 ST_FUNC
void relocate_common_syms(void)
405 unsigned long offset
, align
;
407 for_each_elem(symtab_section
, 1, sym
, ElfW(Sym
)) {
408 if (sym
->st_shndx
== SHN_COMMON
) {
410 align
= sym
->st_value
;
411 offset
= bss_section
->data_offset
;
412 offset
= (offset
+ align
- 1) & -align
;
413 sym
->st_value
= offset
;
414 sym
->st_shndx
= bss_section
->sh_num
;
415 offset
+= sym
->st_size
;
416 bss_section
->data_offset
= offset
;
421 /* relocate symbol table, resolve undefined symbols if do_resolve is
422 true and output error if undefined symbol. */
423 ST_FUNC
void relocate_syms(TCCState
*s1
, int do_resolve
)
425 ElfW(Sym
) *sym
, *esym
;
426 int sym_bind
, sh_num
, sym_index
;
429 for_each_elem(symtab_section
, 1, sym
, ElfW(Sym
)) {
430 sh_num
= sym
->st_shndx
;
431 if (sh_num
== SHN_UNDEF
) {
432 name
= (char *) strtab_section
->data
+ sym
->st_name
;
433 /* Use ld.so to resolve symbol for us (for tcc -run) */
435 #if defined TCC_IS_NATIVE && !defined _WIN32
437 name
= (char *) symtab_section
->link
->data
+ sym
->st_name
;
438 addr
= resolve_sym(s1
, name
);
440 sym
->st_value
= (addr_t
)addr
;
444 } else if (s1
->dynsym
) {
445 /* if dynamic symbol exist, then use it */
446 sym_index
= find_elf_sym(s1
->dynsym
, name
);
448 esym
= &((ElfW(Sym
) *)s1
->dynsym
->data
)[sym_index
];
449 sym
->st_value
= esym
->st_value
;
453 /* XXX: _fp_hw seems to be part of the ABI, so we ignore
455 if (!strcmp(name
, "_fp_hw"))
457 /* only weak symbols are accepted to be undefined. Their
459 sym_bind
= ELFW(ST_BIND
)(sym
->st_info
);
460 if (sym_bind
== STB_WEAK
) {
463 tcc_error_noabort("undefined symbol '%s'", name
);
465 } else if (sh_num
< SHN_LORESERVE
) {
466 /* add section base */
467 sym
->st_value
+= s1
->sections
[sym
->st_shndx
]->sh_addr
;
473 #ifdef TCC_HAS_RUNTIME_PLTGOT
474 #ifdef TCC_TARGET_X86_64
475 #define JMP_TABLE_ENTRY_SIZE 14
476 static addr_t
add_jmp_table(TCCState
*s1
, addr_t val
)
478 char *p
= s1
->runtime_plt_and_got
+ s1
->runtime_plt_and_got_offset
;
479 s1
->runtime_plt_and_got_offset
+= JMP_TABLE_ENTRY_SIZE
;
484 *(addr_t
*)(p
+ 6) = val
;
488 static addr_t
add_got_table(TCCState
*s1
, addr_t val
)
490 addr_t
*p
= (addr_t
*)(s1
->runtime_plt_and_got
+ s1
->runtime_plt_and_got_offset
);
491 s1
->runtime_plt_and_got_offset
+= sizeof(addr_t
);
495 #elif defined TCC_TARGET_ARM
496 #define JMP_TABLE_ENTRY_SIZE 8
497 static addr_t
add_jmp_table(TCCState
*s1
, int val
)
499 uint32_t *p
= (uint32_t *)(s1
->runtime_plt_and_got
+ s1
->runtime_plt_and_got_offset
);
500 s1
->runtime_plt_and_got_offset
+= JMP_TABLE_ENTRY_SIZE
;
501 /* ldr pc, [pc, #-4] */
507 #endif /* def TCC_HAS_RUNTIME_PLTGOT */
509 /* relocate a given section (CPU dependent) by applying the relocations
510 in the associated relocation section */
511 ST_FUNC
void relocate_section(TCCState
*s1
, Section
*s
)
513 Section
*sr
= s
->reloc
;
519 #if defined TCC_TARGET_I386 || defined TCC_TARGET_X86_64
520 ElfW_Rel
*qrel
= (ElfW_Rel
*) sr
->data
; /* ptr to next reloc entry reused */
524 for_each_elem(sr
, 0, rel
, ElfW_Rel
) {
525 ptr
= s
->data
+ rel
->r_offset
;
527 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
528 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
530 #ifdef TCC_TARGET_X86_64
531 val
+= rel
->r_addend
;
533 type
= ELFW(R_TYPE
)(rel
->r_info
);
534 addr
= s
->sh_addr
+ rel
->r_offset
;
538 #if defined(TCC_TARGET_I386)
540 if (s1
->output_type
== TCC_OUTPUT_DLL
) {
541 esym_index
= s1
->symtab_to_dynsym
[sym_index
];
542 qrel
->r_offset
= rel
->r_offset
;
544 qrel
->r_info
= ELFW(R_INFO
)(esym_index
, R_386_32
);
548 qrel
->r_info
= ELFW(R_INFO
)(0, R_386_RELATIVE
);
555 if (s1
->output_type
== TCC_OUTPUT_DLL
) {
557 esym_index
= s1
->symtab_to_dynsym
[sym_index
];
559 qrel
->r_offset
= rel
->r_offset
;
560 qrel
->r_info
= ELFW(R_INFO
)(esym_index
, R_386_PC32
);
565 *(int *)ptr
+= val
- addr
;
568 *(int *)ptr
+= val
- addr
;
575 *(int *)ptr
+= s1
->got
->sh_addr
- addr
;
578 *(int *)ptr
+= val
- s1
->got
->sh_addr
;
581 /* we load the got offset */
582 *(int *)ptr
+= s1
->sym_attrs
[sym_index
].got_offset
;
585 if (s1
->output_format
!= TCC_OUTPUT_FORMAT_BINARY
) {
587 tcc_error("can only produce 16-bit binary files");
589 *(short *)ptr
+= val
;
592 if (s1
->output_format
!= TCC_OUTPUT_FORMAT_BINARY
)
594 *(short *)ptr
+= val
- addr
;
596 #elif defined(TCC_TARGET_ARM)
602 int x
, is_thumb
, is_call
, h
, blx_avail
, is_bl
, th_ko
;
603 x
= (*(int *) ptr
) & 0xffffff;
604 (*(int *)ptr
) &= 0xff000000;
608 blx_avail
= (TCC_ARM_VERSION
>= 5);
610 is_bl
= (*(unsigned *) ptr
) >> 24 == 0xeb;
611 is_call
= (type
== R_ARM_CALL
|| (type
== R_ARM_PC24
&& is_bl
));
614 th_ko
= (x
& 3) && (!blx_avail
|| !is_call
);
615 #ifdef TCC_HAS_RUNTIME_PLTGOT
616 if (s1
->output_type
== TCC_OUTPUT_MEMORY
) {
617 if (th_ko
|| x
>= 0x2000000 || x
< -0x2000000) {
618 x
+= add_jmp_table(s1
, val
) - val
; /* add veneer */
619 th_ko
= (x
& 3) && (!blx_avail
|| !is_call
);
620 is_thumb
= 0; /* Veneer uses ARM instructions */
624 if (th_ko
|| x
>= 0x2000000 || x
< -0x2000000)
625 tcc_error("can't relocate value at %x",addr
);
628 /* Only reached if blx is avail and it is a call */
631 (*(int *)ptr
) = 0xfa << 24; /* bl -> blx */
636 /* Since these relocations only concern Thumb-2 and blx instruction was
637 introduced before Thumb-2, we can assume blx is available and not
640 case R_ARM_THM_JUMP24
:
642 int x
, hi
, lo
, s
, j1
, j2
, i1
, i2
, imm10
, imm11
;
643 int to_thumb
, is_call
, to_plt
, blx_bit
= 1 << 12;
647 if (sym
->st_shndx
== SHN_UNDEF
&&
648 ELFW(ST_BIND
)(sym
->st_info
) == STB_WEAK
)
651 /* Get initial offset */
652 hi
= (*(uint16_t *)ptr
);
653 lo
= (*(uint16_t *)(ptr
+2));
661 x
= (s
<< 24) | (i1
<< 23) | (i2
<< 22) |
662 (imm10
<< 12) | (imm11
<< 1);
666 /* Relocation infos */
669 to_plt
= (val
>= plt
->sh_addr
) &&
670 (val
< plt
->sh_addr
+ plt
->data_offset
);
671 is_call
= (type
== R_ARM_THM_PC22
);
673 /* Compute final offset */
674 if (to_plt
&& !is_call
) /* Point to 1st instr of Thumb stub */
677 if (!to_thumb
&& is_call
) {
678 blx_bit
= 0; /* bl -> blx */
679 x
= (x
+ 3) & -4; /* Compute offset from aligned PC */
682 /* Check that relocation is possible
683 * offset must not be out of range
684 * if target is to be entered in arm mode:
686 - instruction must be a call (bl) or a jump to PLT */
687 if (!to_thumb
|| x
>= 0x1000000 || x
< -0x1000000)
688 if (to_thumb
|| (val
& 2) || (!is_call
&& !to_plt
))
689 tcc_error("can't relocate value at %x",addr
);
691 /* Compute and store final offset */
697 imm10
= (x
>> 12) & 0x3ff;
698 imm11
= (x
>> 1) & 0x7ff;
699 (*(uint16_t *)ptr
) = (uint16_t) ((hi
& 0xf800) |
701 (*(uint16_t *)(ptr
+2)) = (uint16_t) ((lo
& 0xc000) |
702 (j1
<< 13) | blx_bit
| (j2
<< 11) |
707 case R_ARM_MOVW_ABS_NC
:
710 if (type
== R_ARM_MOVT_ABS
)
713 imm4
= (val
>> 12) & 0xf;
714 x
= (imm4
<< 16) | imm12
;
715 if (type
== R_ARM_THM_MOVT_ABS
)
721 case R_ARM_THM_MOVT_ABS
:
722 case R_ARM_THM_MOVW_ABS_NC
:
724 int x
, i
, imm4
, imm3
, imm8
;
725 if (type
== R_ARM_THM_MOVT_ABS
)
728 imm3
= (val
>> 8) & 0x7;
730 imm4
= (val
>> 12) & 0xf;
731 x
= (imm3
<< 28) | (imm8
<< 16) | (i
<< 10) | imm4
;
732 if (type
== R_ARM_THM_MOVT_ABS
)
741 x
= (*(int *)ptr
) & 0x7fffffff;
742 (*(int *)ptr
) &= 0x80000000;
745 if((x
^(x
>>1))&0x40000000)
746 tcc_error("can't relocate value at %x",addr
);
747 (*(int *)ptr
) |= x
& 0x7fffffff;
753 *(int *)ptr
+= val
- addr
;
756 *(int *)ptr
+= s1
->got
->sh_addr
- addr
;
759 *(int *)ptr
+= val
- s1
->got
->sh_addr
;
762 /* we load the got offset */
763 *(int *)ptr
+= s1
->sym_attrs
[sym_index
].got_offset
;
768 /* trade Thumb support for ARMv4 support */
769 if ((0x0ffffff0 & *(int*)ptr
) == 0x012FFF10)
770 *(int*)ptr
^= 0xE12FFF10 ^ 0xE1A0F000; /* BX Rm -> MOV PC, Rm */
773 fprintf(stderr
,"FIXME: handle reloc type %x at %x [%p] to %x\n",
774 type
, (unsigned)addr
, ptr
, (unsigned)val
);
776 #elif defined(TCC_TARGET_C67)
784 /* put the low 16 bits of the absolute address
785 add to what is already there */
787 orig
= ((*(int *)(ptr
)) >> 7) & 0xffff;
788 orig
|= (((*(int *)(ptr
+4)) >> 7) & 0xffff) << 16;
790 /* patch both at once - assumes always in pairs Low - High */
792 *(int *) ptr
= (*(int *) ptr
& (~(0xffff << 7)) ) | (((val
+orig
) & 0xffff) << 7);
793 *(int *)(ptr
+4) = (*(int *)(ptr
+4) & (~(0xffff << 7)) ) | ((((val
+orig
)>>16) & 0xffff) << 7);
799 fprintf(stderr
,"FIXME: handle reloc type %x at %x [%p] to %x\n",
800 type
, (unsigned)addr
, ptr
, (unsigned)val
);
802 #elif defined(TCC_TARGET_X86_64)
804 if (s1
->output_type
== TCC_OUTPUT_DLL
) {
805 esym_index
= s1
->symtab_to_dynsym
[sym_index
];
806 qrel
->r_offset
= rel
->r_offset
;
808 qrel
->r_info
= ELFW(R_INFO
)(esym_index
, R_X86_64_64
);
809 qrel
->r_addend
= rel
->r_addend
;
813 qrel
->r_info
= ELFW(R_INFO
)(0, R_X86_64_RELATIVE
);
814 qrel
->r_addend
= *(long long *)ptr
+ val
;
818 *(long long *)ptr
+= val
;
822 if (s1
->output_type
== TCC_OUTPUT_DLL
) {
823 /* XXX: this logic may depend on TCC's codegen
824 now TCC uses R_X86_64_32 even for a 64bit pointer */
825 qrel
->r_info
= ELFW(R_INFO
)(0, R_X86_64_RELATIVE
);
826 qrel
->r_addend
= *(int *)ptr
+ val
;
833 if (s1
->output_type
== TCC_OUTPUT_DLL
) {
835 esym_index
= s1
->symtab_to_dynsym
[sym_index
];
837 qrel
->r_offset
= rel
->r_offset
;
838 qrel
->r_info
= ELFW(R_INFO
)(esym_index
, R_X86_64_PC32
);
839 qrel
->r_addend
= *(int *)ptr
;
847 /* We've put the PLT slot offset into r_addend when generating
848 it, and that's what we must use as relocation value (adjusted
849 by section offset of course). */
850 if (s1
->output_type
!= TCC_OUTPUT_MEMORY
)
851 val
= s1
->plt
->sh_addr
+ rel
->r_addend
;
857 diff
= (long long)val
- addr
;
858 if (diff
<= -2147483647 || diff
> 2147483647) {
859 #ifdef TCC_HAS_RUNTIME_PLTGOT
860 /* XXX: naive support for over 32bit jump */
861 if (s1
->output_type
== TCC_OUTPUT_MEMORY
) {
862 val
= (add_jmp_table(s1
, val
- rel
->r_addend
) +
867 if (diff
<= -2147483647 || diff
> 2147483647) {
868 tcc_error("internal error: relocation failed");
874 case R_X86_64_GLOB_DAT
:
875 case R_X86_64_JUMP_SLOT
:
876 /* They don't need addend */
877 *(int *)ptr
= val
- rel
->r_addend
;
879 case R_X86_64_GOTPCREL
:
880 #ifdef TCC_HAS_RUNTIME_PLTGOT
881 if (s1
->output_type
== TCC_OUTPUT_MEMORY
) {
882 val
= add_got_table(s1
, val
- rel
->r_addend
) + rel
->r_addend
;
883 *(int *)ptr
+= val
- addr
;
887 *(int *)ptr
+= (s1
->got
->sh_addr
- addr
+
888 s1
->sym_attrs
[sym_index
].got_offset
- 4);
890 case R_X86_64_GOTTPOFF
:
891 *(int *)ptr
+= val
- s1
->got
->sh_addr
;
894 /* we load the got offset */
895 *(int *)ptr
+= s1
->sym_attrs
[sym_index
].got_offset
;
898 #error unsupported processor
902 /* if the relocation is allocated, we change its symbol table */
903 if (sr
->sh_flags
& SHF_ALLOC
)
904 sr
->link
= s1
->dynsym
;
907 /* relocate relocation table in 'sr' */
908 static void relocate_rel(TCCState
*s1
, Section
*sr
)
913 s
= s1
->sections
[sr
->sh_info
];
914 for_each_elem(sr
, 0, rel
, ElfW_Rel
)
915 rel
->r_offset
+= s
->sh_addr
;
918 /* count the number of dynamic relocations so that we can reserve
920 static int prepare_dynamic_rel(TCCState
*s1
, Section
*sr
)
923 int sym_index
, esym_index
, type
, count
;
926 for_each_elem(sr
, 0, rel
, ElfW_Rel
) {
927 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
928 type
= ELFW(R_TYPE
)(rel
->r_info
);
930 #if defined(TCC_TARGET_I386)
932 #elif defined(TCC_TARGET_X86_64)
939 #if defined(TCC_TARGET_I386)
941 #elif defined(TCC_TARGET_X86_64)
944 esym_index
= s1
->symtab_to_dynsym
[sym_index
];
953 /* allocate the section */
954 sr
->sh_flags
|= SHF_ALLOC
;
955 sr
->sh_size
= count
* sizeof(ElfW_Rel
);
960 static struct sym_attr
*alloc_sym_attr(TCCState
*s1
, int index
)
963 struct sym_attr
*tab
;
965 if (index
>= s1
->nb_sym_attrs
) {
966 /* find immediately bigger power of 2 and reallocate array */
970 tab
= tcc_realloc(s1
->sym_attrs
, n
* sizeof(*s1
->sym_attrs
));
972 memset(s1
->sym_attrs
+ s1
->nb_sym_attrs
, 0,
973 (n
- s1
->nb_sym_attrs
) * sizeof(*s1
->sym_attrs
));
974 s1
->nb_sym_attrs
= n
;
976 return &s1
->sym_attrs
[index
];
979 /* XXX: suppress that */
980 static void put32(unsigned char *p
, uint32_t val
)
988 #if defined(TCC_TARGET_I386) || defined(TCC_TARGET_ARM) || \
989 defined(TCC_TARGET_X86_64)
990 static uint32_t get32(unsigned char *p
)
992 return p
[0] | (p
[1] << 8) | (p
[2] << 16) | (p
[3] << 24);
996 static void build_got(TCCState
*s1
)
1000 /* if no got, then create it */
1001 s1
->got
= new_section(s1
, ".got", SHT_PROGBITS
, SHF_ALLOC
| SHF_WRITE
);
1002 s1
->got
->sh_entsize
= 4;
1003 add_elf_sym(symtab_section
, 0, 4, ELFW(ST_INFO
)(STB_GLOBAL
, STT_OBJECT
),
1004 0, s1
->got
->sh_num
, "_GLOBAL_OFFSET_TABLE_");
1005 ptr
= section_ptr_add(s1
->got
, 3 * PTR_SIZE
);
1007 /* keep space for _DYNAMIC pointer, if present */
1009 /* two dummy got entries */
1013 /* keep space for _DYNAMIC pointer, if present */
1016 /* two dummy got entries */
1024 /* put a got or plt entry corresponding to a symbol in symtab_section. 'size'
1025 and 'info' can be modifed if more precise info comes from the DLL.
1026 Returns offset of GOT or PLT slot. */
1027 static unsigned long put_got_entry(TCCState
*s1
,
1028 int reloc_type
, unsigned long size
, int info
,
1031 int index
, need_plt_entry
;
1034 unsigned long offset
;
1036 struct sym_attr
*symattr
;
1041 need_plt_entry
= s1
->dynsym
&&
1042 #ifdef TCC_TARGET_X86_64
1043 (reloc_type
== R_X86_64_JUMP_SLOT
);
1044 #elif defined(TCC_TARGET_I386)
1045 (reloc_type
== R_386_JMP_SLOT
);
1046 #elif defined(TCC_TARGET_ARM)
1047 (reloc_type
== R_ARM_JUMP_SLOT
);
1052 /* If a got/plt entry already exists for that symbol, no need to add one */
1053 if (sym_index
< s1
->nb_sym_attrs
) {
1054 if (need_plt_entry
&& s1
->sym_attrs
[sym_index
].plt_offset
)
1055 return s1
->sym_attrs
[sym_index
].plt_offset
;
1056 else if (!need_plt_entry
&& s1
->sym_attrs
[sym_index
].got_offset
)
1057 return s1
->sym_attrs
[sym_index
].got_offset
;
1060 symattr
= alloc_sym_attr(s1
, sym_index
);
1062 /* Only store the GOT offset if it's not generated for the PLT entry. */
1063 if (!need_plt_entry
)
1064 symattr
->got_offset
= s1
->got
->data_offset
;
1067 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
1068 name
= (char *) symtab_section
->link
->data
+ sym
->st_name
;
1069 offset
= sym
->st_value
;
1070 #if defined(TCC_TARGET_I386) || defined(TCC_TARGET_X86_64)
1071 if (need_plt_entry
) {
1075 unsigned long relofs
;
1077 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
1080 /* if we build a DLL, we add a %ebx offset */
1081 if (s1
->output_type
== TCC_OUTPUT_DLL
)
1087 /* add a PLT entry */
1089 if (plt
->data_offset
== 0) {
1090 /* first plt entry */
1091 p
= section_ptr_add(plt
, 16);
1092 p
[0] = 0xff; /* pushl got + PTR_SIZE */
1093 p
[1] = modrm
+ 0x10;
1094 put32(p
+ 2, PTR_SIZE
);
1095 p
[6] = 0xff; /* jmp *(got + PTR_SIZE * 2) */
1097 put32(p
+ 8, PTR_SIZE
* 2);
1100 /* The PLT slot refers to the relocation entry it needs
1101 via offset. The reloc entry is created below, so its
1102 offset is the current data_offset. */
1103 relofs
= s1
->got
->reloc
? s1
->got
->reloc
->data_offset
: 0;
1104 symattr
->plt_offset
= plt
->data_offset
;
1105 p
= section_ptr_add(plt
, 16);
1106 p
[0] = 0xff; /* jmp *(got + x) */
1108 put32(p
+ 2, s1
->got
->data_offset
);
1109 p
[6] = 0x68; /* push $xxx */
1110 #ifdef TCC_TARGET_X86_64
1111 /* On x86-64, the relocation is referred to by _index_. */
1112 put32(p
+ 7, relofs
/ sizeof (ElfW_Rel
));
1114 put32(p
+ 7, relofs
);
1116 p
[11] = 0xe9; /* jmp plt_start */
1117 put32(p
+ 12, -(plt
->data_offset
));
1119 /* If this was an UNDEF symbol set the offset in the
1120 dynsymtab to the PLT slot, so that PC32 relocs to it
1122 if (sym
->st_shndx
== SHN_UNDEF
)
1123 offset
= plt
->data_offset
- 16;
1125 #elif defined(TCC_TARGET_ARM)
1126 if (need_plt_entry
) {
1130 /* if we build a DLL, we add a %ebx offset */
1131 if (s1
->output_type
== TCC_OUTPUT_DLL
)
1132 tcc_error("DLLs unimplemented!");
1134 /* add a PLT entry */
1136 if (plt
->data_offset
== 0) {
1137 /* first plt entry */
1138 p
= section_ptr_add(plt
, 16);
1139 put32(p
, 0xe52de004); /* push {lr} */
1140 put32(p
+4, 0xe59fe010); /* ldr lr, [pc, #16] */
1141 put32(p
+8, 0xe08fe00e); /* add lr, pc, lr */
1142 put32(p
+12, 0xe5bef008); /* ldr pc, [lr, #8]! */
1145 symattr
->plt_offset
= plt
->data_offset
;
1146 if (symattr
->plt_thumb_stub
) {
1147 p
= section_ptr_add(plt
, 20);
1148 put32(p
, 0x4778); /* bx pc */
1149 put32(p
+2, 0x46c0); /* nop */
1152 p
= section_ptr_add(plt
, 16);
1153 put32(p
, 0xe59fc004); /* ldr ip, [pc, #4] ; GOT entry offset */
1154 put32(p
+4, 0xe08fc00c); /* add ip, pc, ip ; addr of GOT entry */
1155 put32(p
+8, 0xe59cf000); /* ldr pc, [ip] ; jump to GOT entry */
1156 put32(p
+12, s1
->got
->data_offset
); /* GOT entry off once patched */
1158 /* the symbol is modified so that it will be relocated to
1160 if (s1
->output_type
== TCC_OUTPUT_EXE
)
1161 offset
= plt
->data_offset
- 16;
1163 #elif defined(TCC_TARGET_C67)
1164 tcc_error("C67 got not implemented");
1166 #error unsupported CPU
1168 /* XXX This might generate multiple syms for name. */
1169 index
= put_elf_sym(s1
->dynsym
, offset
,
1170 size
, info
, 0, sym
->st_shndx
, name
);
1171 /* Create the relocation (it's against the GOT for PLT
1173 put_elf_reloc(s1
->dynsym
, s1
->got
,
1174 s1
->got
->data_offset
,
1177 /* And now create the GOT slot itself. */
1178 ptr
= section_ptr_add(s1
->got
, PTR_SIZE
);
1181 return symattr
->plt_offset
;
1183 return symattr
->got_offset
;
1186 /* build GOT and PLT entries */
1187 ST_FUNC
void build_got_entries(TCCState
*s1
)
1192 int i
, type
, reloc_type
, sym_index
;
1194 for(i
= 1; i
< s1
->nb_sections
; i
++) {
1195 s
= s1
->sections
[i
];
1196 if (s
->sh_type
!= SHT_RELX
)
1198 /* no need to handle got relocations */
1199 if (s
->link
!= symtab_section
)
1201 for_each_elem(s
, 0, rel
, ElfW_Rel
) {
1202 type
= ELFW(R_TYPE
)(rel
->r_info
);
1204 #if defined(TCC_TARGET_I386)
1211 if (type
== R_386_GOT32
|| type
== R_386_PLT32
) {
1212 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
1213 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
1214 /* look at the symbol got offset. If none, then add one */
1215 if (type
== R_386_GOT32
)
1216 reloc_type
= R_386_GLOB_DAT
;
1218 reloc_type
= R_386_JMP_SLOT
;
1219 put_got_entry(s1
, reloc_type
, sym
->st_size
, sym
->st_info
,
1223 #elif defined(TCC_TARGET_ARM)
1230 if (type
== R_ARM_GOT32
|| type
== R_ARM_PLT32
) {
1231 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
1232 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
1233 /* look at the symbol got offset. If none, then add one */
1234 if (type
== R_ARM_GOT32
)
1235 reloc_type
= R_ARM_GLOB_DAT
;
1237 reloc_type
= R_ARM_JUMP_SLOT
;
1238 put_got_entry(s1
, reloc_type
, sym
->st_size
, sym
->st_info
,
1242 case R_ARM_THM_JUMP24
:
1243 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
1244 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
1245 /* We are relocating a jump from thumb code to arm code */
1246 if (sym
->st_shndx
!= SHN_UNDEF
&& !(sym
->st_value
& 1)) {
1249 char *name
, buf
[1024];
1250 Section
*text_section
;
1252 name
= (char *) symtab_section
->link
->data
+ sym
->st_name
;
1253 text_section
= s1
->sections
[sym
->st_shndx
];
1254 /* Modify reloc to target a thumb stub to switch to ARM */
1255 snprintf(buf
, sizeof(buf
), "%s_from_thumb", name
);
1256 index
= put_elf_sym(symtab_section
,
1257 text_section
->data_offset
+ 1,
1258 sym
->st_size
, sym
->st_info
, 0,
1259 sym
->st_shndx
, buf
);
1260 rel
->r_info
= ELFW(R_INFO
)(index
, type
);
1261 /* Create a thumb stub fonction to switch to ARM mode */
1262 put_elf_reloc(symtab_section
, text_section
,
1263 text_section
->data_offset
+ 4, R_ARM_JUMP24
,
1265 p
= section_ptr_add(text_section
, 8);
1266 put32(p
, 0x4778); /* bx pc */
1267 put32(p
+2, 0x46c0); /* nop */
1268 put32(p
+4, 0xeafffffe); /* b $sym */
1270 #elif defined(TCC_TARGET_C67)
1277 if (type
== R_C60_GOT32
|| type
== R_C60_PLT32
) {
1278 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
1279 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
1280 /* look at the symbol got offset. If none, then add one */
1281 if (type
== R_C60_GOT32
)
1282 reloc_type
= R_C60_GLOB_DAT
;
1284 reloc_type
= R_C60_JMP_SLOT
;
1285 put_got_entry(s1
, reloc_type
, sym
->st_size
, sym
->st_info
,
1289 #elif defined(TCC_TARGET_X86_64)
1290 case R_X86_64_GOT32
:
1291 case R_X86_64_GOTTPOFF
:
1292 case R_X86_64_GOTPCREL
:
1293 case R_X86_64_PLT32
:
1296 if (type
== R_X86_64_GOT32
|| type
== R_X86_64_GOTPCREL
||
1297 type
== R_X86_64_PLT32
) {
1299 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
1300 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
1301 /* look at the symbol got offset. If none, then add one */
1302 if (type
== R_X86_64_GOT32
|| type
== R_X86_64_GOTPCREL
)
1303 reloc_type
= R_X86_64_GLOB_DAT
;
1305 reloc_type
= R_X86_64_JUMP_SLOT
;
1306 ofs
= put_got_entry(s1
, reloc_type
, sym
->st_size
,
1307 sym
->st_info
, sym_index
);
1308 if (type
== R_X86_64_PLT32
1309 && s1
->output_type
!= TCC_OUTPUT_MEMORY
)
1310 /* We store the place of the generated PLT slot
1312 rel
->r_addend
+= ofs
;
1316 #error unsupported CPU
1325 ST_FUNC Section
*new_symtab(TCCState
*s1
,
1326 const char *symtab_name
, int sh_type
, int sh_flags
,
1327 const char *strtab_name
,
1328 const char *hash_name
, int hash_sh_flags
)
1330 Section
*symtab
, *strtab
, *hash
;
1331 int *ptr
, nb_buckets
;
1333 symtab
= new_section(s1
, symtab_name
, sh_type
, sh_flags
);
1334 symtab
->sh_entsize
= sizeof(ElfW(Sym
));
1335 strtab
= new_section(s1
, strtab_name
, SHT_STRTAB
, sh_flags
);
1336 put_elf_str(strtab
, "");
1337 symtab
->link
= strtab
;
1338 put_elf_sym(symtab
, 0, 0, 0, 0, 0, NULL
);
1342 hash
= new_section(s1
, hash_name
, SHT_HASH
, hash_sh_flags
);
1343 hash
->sh_entsize
= sizeof(int);
1344 symtab
->hash
= hash
;
1345 hash
->link
= symtab
;
1347 ptr
= section_ptr_add(hash
, (2 + nb_buckets
+ 1) * sizeof(int));
1348 ptr
[0] = nb_buckets
;
1350 memset(ptr
+ 2, 0, (nb_buckets
+ 1) * sizeof(int));
1354 /* put dynamic tag */
1355 static void put_dt(Section
*dynamic
, int dt
, addr_t val
)
1358 dyn
= section_ptr_add(dynamic
, sizeof(ElfW(Dyn
)));
1360 dyn
->d_un
.d_val
= val
;
1363 static void add_init_array_defines(TCCState
*s1
, const char *section_name
)
1367 char sym_start
[1024];
1370 snprintf(sym_start
, sizeof(sym_start
), "__%s_start", section_name
+ 1);
1371 snprintf(sym_end
, sizeof(sym_end
), "__%s_end", section_name
+ 1);
1373 s
= find_section(s1
, section_name
);
1378 end_offset
= s
->data_offset
;
1381 add_elf_sym(symtab_section
,
1383 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1384 s
->sh_num
, sym_start
);
1385 add_elf_sym(symtab_section
,
1387 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1388 s
->sh_num
, sym_end
);
1391 ST_FUNC
void tcc_add_bcheck(TCCState
*s1
)
1393 #ifdef CONFIG_TCC_BCHECK
1395 Section
*init_section
;
1396 unsigned char *pinit
;
1399 if (0 == s1
->do_bounds_check
)
1402 /* XXX: add an object file to do that */
1403 ptr
= section_ptr_add(bounds_section
, sizeof(unsigned long));
1405 add_elf_sym(symtab_section
, 0, 0,
1406 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1407 bounds_section
->sh_num
, "__bounds_start");
1408 #ifdef TCC_TARGET_I386
1409 if (s1
->output_type
!= TCC_OUTPUT_MEMORY
) {
1410 /* add 'call __bound_init()' in .init section */
1411 init_section
= find_section(s1
, ".init");
1412 pinit
= section_ptr_add(init_section
, 5);
1414 put32(pinit
+ 1, -4);
1415 sym_index
= find_elf_sym(symtab_section
, "__bound_init");
1416 put_elf_reloc(symtab_section
, init_section
,
1417 init_section
->data_offset
- 4, R_386_PC32
, sym_index
);
1423 static inline int tcc_add_support(TCCState
*s1
, const char *filename
)
1426 snprintf(buf
, sizeof(buf
), "%s/%s", s1
->tcc_lib_path
, filename
);
1427 return tcc_add_file(s1
, buf
);
1430 /* add tcc runtime libraries */
1431 ST_FUNC
void tcc_add_runtime(TCCState
*s1
)
1434 if (!s1
->nostdlib
) {
1435 tcc_add_library(s1
, "c");
1436 #ifdef CONFIG_USE_LIBGCC
1437 if (!s1
->static_link
) {
1438 tcc_add_file(s1
, TCC_LIBGCC
);
1439 tcc_add_support(s1
, "libtcc1.a");
1441 tcc_add_support(s1
, "libtcc1.a");
1443 tcc_add_support(s1
, "libtcc1.a");
1447 /* tcc_add_bcheck tries to relocate a call to __bound_init in _init so
1448 libtcc1.a must be loaded before for __bound_init to be defined and
1449 crtn.o must be loaded after to not finalize _init too early. */
1452 if (!s1
->nostdlib
) {
1453 /* add crt end if not memory output */
1454 if (s1
->output_type
!= TCC_OUTPUT_MEMORY
)
1455 tcc_add_crt(s1
, "crtn.o");
1459 /* add various standard linker symbols (must be done after the
1460 sections are filled (for example after allocating common
1462 ST_FUNC
void tcc_add_linker_symbols(TCCState
*s1
)
1468 add_elf_sym(symtab_section
,
1469 text_section
->data_offset
, 0,
1470 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1471 text_section
->sh_num
, "_etext");
1472 add_elf_sym(symtab_section
,
1473 data_section
->data_offset
, 0,
1474 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1475 data_section
->sh_num
, "_edata");
1476 add_elf_sym(symtab_section
,
1477 bss_section
->data_offset
, 0,
1478 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1479 bss_section
->sh_num
, "_end");
1480 /* horrible new standard ldscript defines */
1481 add_init_array_defines(s1
, ".preinit_array");
1482 add_init_array_defines(s1
, ".init_array");
1483 add_init_array_defines(s1
, ".fini_array");
1485 /* add start and stop symbols for sections whose name can be
1487 for(i
= 1; i
< s1
->nb_sections
; i
++) {
1488 s
= s1
->sections
[i
];
1489 if (s
->sh_type
== SHT_PROGBITS
&&
1490 (s
->sh_flags
& SHF_ALLOC
)) {
1494 /* check if section name can be expressed in C */
1500 if (!isid(ch
) && !isnum(ch
))
1504 snprintf(buf
, sizeof(buf
), "__start_%s", s
->name
);
1505 add_elf_sym(symtab_section
,
1507 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1509 snprintf(buf
, sizeof(buf
), "__stop_%s", s
->name
);
1510 add_elf_sym(symtab_section
,
1512 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1519 static void tcc_output_binary(TCCState
*s1
, FILE *f
,
1520 const int *sec_order
)
1523 int i
, offset
, size
;
1526 for(i
=1;i
<s1
->nb_sections
;i
++) {
1527 s
= s1
->sections
[sec_order
[i
]];
1528 if (s
->sh_type
!= SHT_NOBITS
&&
1529 (s
->sh_flags
& SHF_ALLOC
)) {
1530 while (offset
< s
->sh_offset
) {
1535 fwrite(s
->data
, 1, size
, f
);
1541 // making this evaluate to true allow valgrind to work on linux
1542 // but when compiled with debug info and then striped
1543 // the compiled programs segfault
1544 // more tought must be applyed here
1545 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1547 #define EXTRA_RELITEMS 14
1549 /* move the relocation value from .dynsym to .got */
1550 void patch_dynsym_undef(TCCState
*s1
, Section
*s
)
1552 uint32_t *gotd
= (void *)s1
->got
->data
;
1555 gotd
+= 3; /* dummy entries in .got */
1556 /* relocate symbols in .dynsym */
1557 for_each_elem(s
, 1, sym
, ElfW(Sym
)) {
1558 if (sym
->st_shndx
== SHN_UNDEF
) {
1559 *gotd
++ = sym
->st_value
+ 6; /* XXX 6 is magic ? */
1566 #define EXTRA_RELITEMS 9
1568 /* zero plt offsets of weak symbols in .dynsym */
1569 void patch_dynsym_undef(TCCState
*s1
, Section
*s
)
1573 for_each_elem(s
, 1, sym
, ElfW(Sym
))
1574 if (sym
->st_shndx
== SHN_UNDEF
&& ELFW(ST_BIND
)(sym
->st_info
) == STB_WEAK
)
1579 ST_FUNC
void fill_got_entry(TCCState
*s1
, ElfW_Rel
*rel
)
1581 int sym_index
= ELFW(R_SYM
) (rel
->r_info
);
1582 ElfW(Sym
) *sym
= &((ElfW(Sym
) *) symtab_section
->data
)[sym_index
];
1583 unsigned long offset
;
1585 if (sym_index
>= s1
->nb_sym_attrs
)
1587 offset
= s1
->sym_attrs
[sym_index
].got_offset
;
1588 section_reserve(s1
->got
, offset
+ PTR_SIZE
);
1589 #ifdef TCC_TARGET_X86_64
1590 /* only works for x86-64 */
1591 put32(s1
->got
->data
+ offset
+ 4, sym
->st_value
>> 32);
1593 put32(s1
->got
->data
+ offset
, sym
->st_value
& 0xffffffff);
1596 /* Perform relocation to GOT or PLTÂ entries */
1597 ST_FUNC
void fill_got(TCCState
*s1
)
1603 for(i
= 1; i
< s1
->nb_sections
; i
++) {
1604 s
= s1
->sections
[i
];
1605 if (s
->sh_type
!= SHT_RELX
)
1607 /* no need to handle got relocations */
1608 if (s
->link
!= symtab_section
)
1610 for_each_elem(s
, 0, rel
, ElfW_Rel
) {
1611 switch (ELFW(R_TYPE
) (rel
->r_info
)) {
1612 case R_X86_64_GOT32
:
1613 case R_X86_64_GOTPCREL
:
1614 case R_X86_64_PLT32
:
1615 fill_got_entry(s1
, rel
);
1622 /* Bind symbols of executable: resolve undefined symbols from exported symbols
1623 in shared libraries and export non local defined symbols to shared libraries
1624 if -rdynamic switch was given on command line */
1625 static void bind_exe_dynsyms(TCCState
*s1
)
1628 int sym_index
, index
;
1629 ElfW(Sym
) *sym
, *esym
;
1632 /* Resolve undefined symbols from dynamic symbols. When there is a match:
1633 - if STT_FUNC or STT_GNU_IFUNC symbol -> add it in PLT
1634 - if STT_OBJECT symbol -> add it in .bss section with suitable reloc */
1635 for_each_elem(symtab_section
, 1, sym
, ElfW(Sym
)) {
1636 if (sym
->st_shndx
== SHN_UNDEF
) {
1637 name
= (char *) symtab_section
->link
->data
+ sym
->st_name
;
1638 sym_index
= find_elf_sym(s1
->dynsymtab_section
, name
);
1640 esym
= &((ElfW(Sym
) *)s1
->dynsymtab_section
->data
)[sym_index
];
1641 type
= ELFW(ST_TYPE
)(esym
->st_info
);
1642 if ((type
== STT_FUNC
) || (type
== STT_GNU_IFUNC
)) {
1643 /* Indirect functions shall have STT_FUNC type in executable
1644 * dynsym section. Indeed, a dlsym call following a lazy
1645 * resolution would pick the symbol value from the
1646 * executable dynsym entry which would contain the address
1647 * of the function wanted by the caller of dlsym instead of
1648 * the address of the function that would return that
1650 put_got_entry(s1
, R_JMP_SLOT
, esym
->st_size
,
1651 ELFW(ST_INFO
)(STB_GLOBAL
,STT_FUNC
),
1652 sym
- (ElfW(Sym
) *)symtab_section
->data
);
1653 } else if (type
== STT_OBJECT
) {
1654 unsigned long offset
;
1656 offset
= bss_section
->data_offset
;
1657 /* XXX: which alignment ? */
1658 offset
= (offset
+ 16 - 1) & -16;
1659 index
= put_elf_sym(s1
->dynsym
, offset
, esym
->st_size
,
1660 esym
->st_info
, 0, bss_section
->sh_num
,
1662 /* Ensure R_COPY works for weak symbol aliases */
1663 if (ELFW(ST_BIND
)(esym
->st_info
) == STB_WEAK
) {
1664 for_each_elem(s1
->dynsymtab_section
, 1, dynsym
, ElfW(Sym
)) {
1665 if ((dynsym
->st_value
== esym
->st_value
)
1666 && (ELFW(ST_BIND
)(dynsym
->st_info
) == STB_GLOBAL
)) {
1667 char *dynname
= (char *) s1
->dynsymtab_section
->link
->data
1669 put_elf_sym(s1
->dynsym
, offset
, dynsym
->st_size
,
1671 bss_section
->sh_num
, dynname
);
1676 put_elf_reloc(s1
->dynsym
, bss_section
,
1677 offset
, R_COPY
, index
);
1678 offset
+= esym
->st_size
;
1679 bss_section
->data_offset
= offset
;
1682 /* STB_WEAK undefined symbols are accepted */
1683 /* XXX: _fp_hw seems to be part of the ABI, so we ignore it */
1684 if (ELFW(ST_BIND
)(sym
->st_info
) == STB_WEAK
||
1685 !strcmp(name
, "_fp_hw")) {
1687 tcc_error_noabort("undefined symbol '%s'", name
);
1690 } else if (s1
->rdynamic
&& ELFW(ST_BIND
)(sym
->st_info
) != STB_LOCAL
) {
1691 /* if -rdynamic option, then export all non local symbols */
1692 name
= (char *) symtab_section
->link
->data
+ sym
->st_name
;
1693 put_elf_sym(s1
->dynsym
, sym
->st_value
, sym
->st_size
, sym
->st_info
,
1694 0, sym
->st_shndx
, name
);
1699 /* Bind symbols of libraries: export non local symbols of executable that
1700 resolve undefined symbols of shared libraries */
1701 static void bind_libs_dynsyms(TCCState
*s1
)
1705 ElfW(Sym
) *sym
, *esym
;
1707 /* now look at unresolved dynamic symbols and export
1708 corresponding symbol */
1709 for_each_elem(s1
->dynsymtab_section
, 1, esym
, ElfW(Sym
)) {
1710 if (esym
->st_shndx
== SHN_UNDEF
) {
1711 name
= (char *) s1
->dynsymtab_section
->link
->data
+ esym
->st_name
;
1712 sym_index
= find_elf_sym(symtab_section
, name
);
1714 /* XXX: avoid adding a symbol if already present because of
1716 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
1717 put_elf_sym(s1
->dynsym
, sym
->st_value
, sym
->st_size
,
1718 sym
->st_info
, 0, sym
->st_shndx
, name
);
1720 /* weak symbols can stay undefined */
1721 if (ELFW(ST_BIND
)(esym
->st_info
) != STB_WEAK
)
1722 tcc_warning("undefined dynamic symbol '%s'", name
);
1728 /* Export all non local symbols (for shared libraries) */
1729 static void export_global_syms(TCCState
*s1
)
1731 int nb_syms
, dynindex
, index
;
1735 nb_syms
= symtab_section
->data_offset
/ sizeof(ElfW(Sym
));
1736 s1
->symtab_to_dynsym
= tcc_mallocz(sizeof(int) * nb_syms
);
1737 for_each_elem(symtab_section
, 1, sym
, ElfW(Sym
)) {
1738 if (ELFW(ST_BIND
)(sym
->st_info
) != STB_LOCAL
) {
1739 name
= (char *) symtab_section
->link
->data
+ sym
->st_name
;
1740 dynindex
= put_elf_sym(s1
->dynsym
, sym
->st_value
, sym
->st_size
,
1741 sym
->st_info
, 0, sym
->st_shndx
, name
);
1742 index
= sym
- (ElfW(Sym
) *) symtab_section
->data
;
1743 s1
->symtab_to_dynsym
[index
] = dynindex
;
1748 /* relocate the PLT: compute addresses and offsets in the PLT now that final
1749 address for PLT and GOT are known (see fill_program_header) */
1750 static void relocate_plt(TCCState
*s1
)
1755 p_end
= p
+ s1
->plt
->data_offset
;
1757 #if defined(TCC_TARGET_I386)
1758 put32(p
+ 2, get32(p
+ 2) + s1
->got
->sh_addr
);
1759 put32(p
+ 8, get32(p
+ 8) + s1
->got
->sh_addr
);
1762 put32(p
+ 2, get32(p
+ 2) + s1
->got
->sh_addr
);
1765 #elif defined(TCC_TARGET_X86_64)
1766 int x
= s1
->got
->sh_addr
- s1
->plt
->sh_addr
- 6;
1767 put32(p
+ 2, get32(p
+ 2) + x
);
1768 put32(p
+ 8, get32(p
+ 8) + x
- 6);
1771 put32(p
+ 2, get32(p
+ 2) + x
+ s1
->plt
->data
- p
);
1774 #elif defined(TCC_TARGET_ARM)
1776 x
=s1
->got
->sh_addr
- s1
->plt
->sh_addr
- 12;
1779 if (get32(p
) == 0x46c04778) /* PLT Thumb stub present */
1781 put32(p
+ 12, x
+ get32(p
+ 12) + s1
->plt
->data
- p
);
1784 #elif defined(TCC_TARGET_C67)
1787 #error unsupported CPU
1792 /* Allocate strings for section names and decide if an unallocated section
1795 NOTE: the strsec section comes last, so its size is also correct ! */
1796 static void alloc_sec_names(TCCState
*s1
, int file_type
, Section
*strsec
)
1801 /* Allocate strings for section names */
1802 for(i
= 1; i
< s1
->nb_sections
; i
++) {
1803 s
= s1
->sections
[i
];
1804 s
->sh_name
= put_elf_str(strsec
, s
->name
);
1805 /* when generating a DLL, we include relocations but we may
1807 if (file_type
== TCC_OUTPUT_DLL
&&
1808 s
->sh_type
== SHT_RELX
&&
1809 !(s
->sh_flags
& SHF_ALLOC
)) {
1810 /* gr: avoid bogus relocs for empty (debug) sections */
1811 if (s1
->sections
[s
->sh_info
]->sh_flags
& SHF_ALLOC
)
1812 prepare_dynamic_rel(s1
, s
);
1813 else if (s1
->do_debug
)
1814 s
->sh_size
= s
->data_offset
;
1815 } else if (s1
->do_debug
||
1816 file_type
== TCC_OUTPUT_OBJ
||
1817 (s
->sh_flags
& SHF_ALLOC
) ||
1818 i
== (s1
->nb_sections
- 1)) {
1819 /* we output all sections if debug or object file */
1820 s
->sh_size
= s
->data_offset
;
1825 /* Info to be copied in dynamic section */
1829 unsigned long dyn_rel_off
;
1832 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1838 /* Assign sections to segments and decide how are sections laid out when loaded
1839 in memory. This function also fills corresponding program headers. */
1840 static int layout_sections(TCCState
*s1
, ElfW(Phdr
) *phdr
, int phnum
,
1841 Section
*interp
, struct dyn_inf
*dyninf
,
1844 int i
, j
, k
, file_type
, sh_order_index
, file_offset
;
1850 file_type
= s1
->output_type
;
1852 if (s1
->output_format
== TCC_OUTPUT_FORMAT_ELF
)
1853 file_offset
= sizeof(ElfW(Ehdr
)) + phnum
* sizeof(ElfW(Phdr
));
1858 if (s1
->has_text_addr
) {
1859 int a_offset
, p_offset
;
1860 addr
= s1
->text_addr
;
1861 /* we ensure that (addr % ELF_PAGE_SIZE) == file_offset %
1863 a_offset
= (int) (addr
& (s1
->section_align
- 1));
1864 p_offset
= file_offset
& (s1
->section_align
- 1);
1865 if (a_offset
< p_offset
)
1866 a_offset
+= s1
->section_align
;
1867 file_offset
+= (a_offset
- p_offset
);
1869 if (file_type
== TCC_OUTPUT_DLL
)
1872 addr
= ELF_START_ADDR
;
1873 /* compute address after headers */
1874 addr
+= (file_offset
& (s1
->section_align
- 1));
1878 /* Leave one program headers for the program interpreter and one for
1879 the program header table itself if needed. These are done later as
1880 they require section layout to be done first. */
1882 ph
+= 1 + HAVE_PHDR
;
1884 /* dynamic relocation table information, for .dynamic section */
1885 dyninf
->rel_addr
= dyninf
->rel_size
= 0;
1886 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1887 dyninf
->bss_addr
= dyninf
->bss_size
= 0;
1890 for(j
= 0; j
< 2; j
++) {
1891 ph
->p_type
= PT_LOAD
;
1893 ph
->p_flags
= PF_R
| PF_X
;
1895 ph
->p_flags
= PF_R
| PF_W
;
1896 ph
->p_align
= s1
->section_align
;
1898 /* Decide the layout of sections loaded in memory. This must
1899 be done before program headers are filled since they contain
1900 info about the layout. We do the following ordering: interp,
1901 symbol tables, relocations, progbits, nobits */
1902 /* XXX: do faster and simpler sorting */
1903 for(k
= 0; k
< 5; k
++) {
1904 for(i
= 1; i
< s1
->nb_sections
; i
++) {
1905 s
= s1
->sections
[i
];
1906 /* compute if section should be included */
1908 if ((s
->sh_flags
& (SHF_ALLOC
| SHF_WRITE
)) !=
1912 if ((s
->sh_flags
& (SHF_ALLOC
| SHF_WRITE
)) !=
1913 (SHF_ALLOC
| SHF_WRITE
))
1919 } else if (s
->sh_type
== SHT_DYNSYM
||
1920 s
->sh_type
== SHT_STRTAB
||
1921 s
->sh_type
== SHT_HASH
) {
1924 } else if (s
->sh_type
== SHT_RELX
) {
1927 } else if (s
->sh_type
== SHT_NOBITS
) {
1934 sec_order
[sh_order_index
++] = i
;
1936 /* section matches: we align it and add its size */
1938 addr
= (addr
+ s
->sh_addralign
- 1) &
1939 ~(s
->sh_addralign
- 1);
1940 file_offset
+= (int) ( addr
- tmp
);
1941 s
->sh_offset
= file_offset
;
1944 /* update program header infos */
1945 if (ph
->p_offset
== 0) {
1946 ph
->p_offset
= file_offset
;
1948 ph
->p_paddr
= ph
->p_vaddr
;
1950 /* update dynamic relocation infos */
1951 if (s
->sh_type
== SHT_RELX
) {
1952 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
1953 if (!strcmp(strsec
->data
+ s
->sh_name
, ".rel.got")) {
1954 dyninf
->rel_addr
= addr
;
1955 dyninf
->rel_size
+= s
->sh_size
; /* XXX only first rel. */
1957 if (!strcmp(strsec
->data
+ s
->sh_name
, ".rel.bss")) {
1958 dyninf
->bss_addr
= addr
;
1959 dyninf
->bss_size
= s
->sh_size
; /* XXX only first rel. */
1962 if (dyninf
->rel_size
== 0)
1963 dyninf
->rel_addr
= addr
;
1964 dyninf
->rel_size
+= s
->sh_size
;
1968 if (s
->sh_type
!= SHT_NOBITS
)
1969 file_offset
+= s
->sh_size
;
1972 ph
->p_filesz
= file_offset
- ph
->p_offset
;
1973 ph
->p_memsz
= addr
- ph
->p_vaddr
;
1976 if (s1
->output_format
== TCC_OUTPUT_FORMAT_ELF
) {
1977 /* if in the middle of a page, we duplicate the page in
1978 memory so that one copy is RX and the other is RW */
1979 if ((addr
& (s1
->section_align
- 1)) != 0)
1980 addr
+= s1
->section_align
;
1982 addr
= (addr
+ s1
->section_align
- 1) & ~(s1
->section_align
- 1);
1983 file_offset
= (file_offset
+ s1
->section_align
- 1) &
1984 ~(s1
->section_align
- 1);
1990 /* all other sections come after */
1991 for(i
= 1; i
< s1
->nb_sections
; i
++) {
1992 s
= s1
->sections
[i
];
1993 if (phnum
> 0 && (s
->sh_flags
& SHF_ALLOC
))
1995 sec_order
[sh_order_index
++] = i
;
1997 file_offset
= (file_offset
+ s
->sh_addralign
- 1) &
1998 ~(s
->sh_addralign
- 1);
1999 s
->sh_offset
= file_offset
;
2000 if (s
->sh_type
!= SHT_NOBITS
)
2001 file_offset
+= s
->sh_size
;
2007 static void fill_unloadable_phdr(ElfW(Phdr
) *phdr
, int phnum
, Section
*interp
,
2012 /* if interpreter, then add corresponding program header */
2018 int len
= phnum
* sizeof(ElfW(Phdr
));
2020 ph
->p_type
= PT_PHDR
;
2021 ph
->p_offset
= sizeof(ElfW(Ehdr
));
2022 ph
->p_vaddr
= interp
->sh_addr
- len
;
2023 ph
->p_paddr
= ph
->p_vaddr
;
2024 ph
->p_filesz
= ph
->p_memsz
= len
;
2025 ph
->p_flags
= PF_R
| PF_X
;
2026 ph
->p_align
= 4; /* interp->sh_addralign; */
2030 ph
->p_type
= PT_INTERP
;
2031 ph
->p_offset
= interp
->sh_offset
;
2032 ph
->p_vaddr
= interp
->sh_addr
;
2033 ph
->p_paddr
= ph
->p_vaddr
;
2034 ph
->p_filesz
= interp
->sh_size
;
2035 ph
->p_memsz
= interp
->sh_size
;
2037 ph
->p_align
= interp
->sh_addralign
;
2040 /* if dynamic section, then add corresponding program header */
2042 ph
= &phdr
[phnum
- 1];
2044 ph
->p_type
= PT_DYNAMIC
;
2045 ph
->p_offset
= dynamic
->sh_offset
;
2046 ph
->p_vaddr
= dynamic
->sh_addr
;
2047 ph
->p_paddr
= ph
->p_vaddr
;
2048 ph
->p_filesz
= dynamic
->sh_size
;
2049 ph
->p_memsz
= dynamic
->sh_size
;
2050 ph
->p_flags
= PF_R
| PF_W
;
2051 ph
->p_align
= dynamic
->sh_addralign
;
2055 /* Fill the dynamic section with tags describing the address and size of
2057 static void fill_dynamic(TCCState
*s1
, struct dyn_inf
*dyninf
)
2061 dynamic
= dyninf
->dynamic
;
2063 /* put dynamic section entries */
2064 dynamic
->data_offset
= dyninf
->dyn_rel_off
;
2065 put_dt(dynamic
, DT_HASH
, s1
->dynsym
->hash
->sh_addr
);
2066 put_dt(dynamic
, DT_STRTAB
, dyninf
->dynstr
->sh_addr
);
2067 put_dt(dynamic
, DT_SYMTAB
, s1
->dynsym
->sh_addr
);
2068 put_dt(dynamic
, DT_STRSZ
, dyninf
->dynstr
->data_offset
);
2069 put_dt(dynamic
, DT_SYMENT
, sizeof(ElfW(Sym
)));
2070 #ifdef TCC_TARGET_X86_64
2071 put_dt(dynamic
, DT_RELA
, dyninf
->rel_addr
);
2072 put_dt(dynamic
, DT_RELASZ
, dyninf
->rel_size
);
2073 put_dt(dynamic
, DT_RELAENT
, sizeof(ElfW_Rel
));
2075 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2076 put_dt(dynamic
, DT_PLTGOT
, s1
->got
->sh_addr
);
2077 put_dt(dynamic
, DT_PLTRELSZ
, dyninf
->rel_size
);
2078 put_dt(dynamic
, DT_JMPREL
, dyninf
->rel_addr
);
2079 put_dt(dynamic
, DT_PLTREL
, DT_REL
);
2080 put_dt(dynamic
, DT_REL
, dyninf
->bss_addr
);
2081 put_dt(dynamic
, DT_RELSZ
, dyninf
->bss_size
);
2083 put_dt(dynamic
, DT_REL
, dyninf
->rel_addr
);
2084 put_dt(dynamic
, DT_RELSZ
, dyninf
->rel_size
);
2085 put_dt(dynamic
, DT_RELENT
, sizeof(ElfW_Rel
));
2089 put_dt(dynamic
, DT_DEBUG
, 0);
2090 put_dt(dynamic
, DT_NULL
, 0);
2093 /* Relocate remaining sections and symbols (that is those not related to
2095 static int final_sections_reloc(TCCState
*s1
)
2100 relocate_syms(s1
, 0);
2102 if (s1
->nb_errors
!= 0)
2105 /* relocate sections */
2106 /* XXX: ignore sections with allocated relocations ? */
2107 for(i
= 1; i
< s1
->nb_sections
; i
++) {
2108 s
= s1
->sections
[i
];
2109 if (s
->reloc
&& s
!= s1
->got
)
2110 relocate_section(s1
, s
);
2113 /* relocate relocation entries if the relocation tables are
2114 allocated in the executable */
2115 for(i
= 1; i
< s1
->nb_sections
; i
++) {
2116 s
= s1
->sections
[i
];
2117 if ((s
->sh_flags
& SHF_ALLOC
) &&
2118 s
->sh_type
== SHT_RELX
) {
2119 relocate_rel(s1
, s
);
2125 /* Create an ELF file on disk.
2126 This function handle ELF specific layout requirements */
2127 static void tcc_output_elf(TCCState
*s1
, FILE *f
, int phnum
, ElfW(Phdr
) *phdr
,
2128 int file_offset
, int *sec_order
)
2130 int i
, shnum
, offset
, size
, file_type
;
2133 ElfW(Shdr
) shdr
, *sh
;
2135 file_type
= s1
->output_type
;
2136 shnum
= s1
->nb_sections
;
2138 memset(&ehdr
, 0, sizeof(ehdr
));
2141 ehdr
.e_phentsize
= sizeof(ElfW(Phdr
));
2142 ehdr
.e_phnum
= phnum
;
2143 ehdr
.e_phoff
= sizeof(ElfW(Ehdr
));
2147 file_offset
= (file_offset
+ 3) & -4;
2150 ehdr
.e_ident
[0] = ELFMAG0
;
2151 ehdr
.e_ident
[1] = ELFMAG1
;
2152 ehdr
.e_ident
[2] = ELFMAG2
;
2153 ehdr
.e_ident
[3] = ELFMAG3
;
2154 ehdr
.e_ident
[4] = ELFCLASSW
;
2155 ehdr
.e_ident
[5] = ELFDATA2LSB
;
2156 ehdr
.e_ident
[6] = EV_CURRENT
;
2157 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
2158 ehdr
.e_ident
[EI_OSABI
] = ELFOSABI_FREEBSD
;
2160 #ifdef TCC_TARGET_ARM
2162 ehdr
.e_ident
[EI_OSABI
] = 0;
2163 ehdr
.e_flags
= EF_ARM_EABI_VER4
;
2164 if (file_type
== TCC_OUTPUT_EXE
|| file_type
== TCC_OUTPUT_DLL
)
2165 ehdr
.e_flags
|= EF_ARM_HASENTRY
;
2166 if (s1
->float_abi
== ARM_HARD_FLOAT
)
2167 ehdr
.e_flags
|= EF_ARM_VFP_FLOAT
;
2169 ehdr
.e_flags
|= EF_ARM_SOFT_FLOAT
;
2171 ehdr
.e_ident
[EI_OSABI
] = ELFOSABI_ARM
;
2176 case TCC_OUTPUT_EXE
:
2177 ehdr
.e_type
= ET_EXEC
;
2178 ehdr
.e_entry
= get_elf_sym_addr(s1
, "_start", 1);
2180 case TCC_OUTPUT_DLL
:
2181 ehdr
.e_type
= ET_DYN
;
2182 ehdr
.e_entry
= text_section
->sh_addr
; /* XXX: is it correct ? */
2184 case TCC_OUTPUT_OBJ
:
2185 ehdr
.e_type
= ET_REL
;
2188 ehdr
.e_machine
= EM_TCC_TARGET
;
2189 ehdr
.e_version
= EV_CURRENT
;
2190 ehdr
.e_shoff
= file_offset
;
2191 ehdr
.e_ehsize
= sizeof(ElfW(Ehdr
));
2192 ehdr
.e_shentsize
= sizeof(ElfW(Shdr
));
2193 ehdr
.e_shnum
= shnum
;
2194 ehdr
.e_shstrndx
= shnum
- 1;
2196 fwrite(&ehdr
, 1, sizeof(ElfW(Ehdr
)), f
);
2197 fwrite(phdr
, 1, phnum
* sizeof(ElfW(Phdr
)), f
);
2198 offset
= sizeof(ElfW(Ehdr
)) + phnum
* sizeof(ElfW(Phdr
));
2200 sort_syms(s1
, symtab_section
);
2201 for(i
= 1; i
< s1
->nb_sections
; i
++) {
2202 s
= s1
->sections
[sec_order
[i
]];
2203 if (s
->sh_type
!= SHT_NOBITS
) {
2204 if (s
->sh_type
== SHT_DYNSYM
)
2205 patch_dynsym_undef(s1
, s
);
2206 while (offset
< s
->sh_offset
) {
2211 fwrite(s
->data
, 1, size
, f
);
2216 /* output section headers */
2217 while (offset
< ehdr
.e_shoff
) {
2222 for(i
= 0; i
< s1
->nb_sections
; i
++) {
2224 memset(sh
, 0, sizeof(ElfW(Shdr
)));
2225 s
= s1
->sections
[i
];
2227 sh
->sh_name
= s
->sh_name
;
2228 sh
->sh_type
= s
->sh_type
;
2229 sh
->sh_flags
= s
->sh_flags
;
2230 sh
->sh_entsize
= s
->sh_entsize
;
2231 sh
->sh_info
= s
->sh_info
;
2233 sh
->sh_link
= s
->link
->sh_num
;
2234 sh
->sh_addralign
= s
->sh_addralign
;
2235 sh
->sh_addr
= s
->sh_addr
;
2236 sh
->sh_offset
= s
->sh_offset
;
2237 sh
->sh_size
= s
->sh_size
;
2239 fwrite(sh
, 1, sizeof(ElfW(Shdr
)), f
);
2243 /* Write an elf, coff or "binary" file */
2244 static int tcc_write_elf_file(TCCState
*s1
, const char *filename
, int phnum
,
2245 ElfW(Phdr
) *phdr
, int file_offset
, int *sec_order
)
2247 int fd
, mode
, file_type
;
2250 file_type
= s1
->output_type
;
2251 if (file_type
== TCC_OUTPUT_OBJ
)
2256 fd
= open(filename
, O_WRONLY
| O_CREAT
| O_TRUNC
| O_BINARY
, mode
);
2258 tcc_error_noabort("could not write '%s'", filename
);
2261 f
= fdopen(fd
, "wb");
2263 printf("<- %s\n", filename
);
2265 #ifdef TCC_TARGET_COFF
2266 if (s1
->output_format
== TCC_OUTPUT_FORMAT_COFF
)
2267 tcc_output_coff(s1
, f
);
2270 if (s1
->output_format
== TCC_OUTPUT_FORMAT_ELF
)
2271 tcc_output_elf(s1
, f
, phnum
, phdr
, file_offset
, sec_order
);
2273 tcc_output_binary(s1
, f
, sec_order
);
2279 /* Output an elf, coff or binary file */
2280 /* XXX: suppress unneeded sections */
2281 static int elf_output_file(TCCState
*s1
, const char *filename
)
2283 int i
, ret
, phnum
, shnum
, file_type
, file_offset
, *sec_order
;
2284 struct dyn_inf dyninf
;
2287 Section
*strsec
, *interp
, *dynamic
, *dynstr
;
2289 file_type
= s1
->output_type
;
2292 /* if linking, also link in runtime libraries (libc, libgcc, etc.) */
2293 if (file_type
!= TCC_OUTPUT_OBJ
) {
2294 tcc_add_runtime(s1
);
2299 interp
= dynamic
= dynstr
= NULL
; /* avoid warning */
2300 dyninf
.dyn_rel_off
= 0; /* avoid warning */
2302 if (file_type
!= TCC_OUTPUT_OBJ
) {
2303 relocate_common_syms();
2305 tcc_add_linker_symbols(s1
);
2307 if (!s1
->static_link
) {
2308 if (file_type
== TCC_OUTPUT_EXE
) {
2310 /* allow override the dynamic loader */
2311 const char *elfint
= getenv("LD_SO");
2313 elfint
= DEFAULT_ELFINTERP(s1
);
2314 /* add interpreter section only if executable */
2315 interp
= new_section(s1
, ".interp", SHT_PROGBITS
, SHF_ALLOC
);
2316 interp
->sh_addralign
= 1;
2317 ptr
= section_ptr_add(interp
, 1 + strlen(elfint
));
2318 strcpy(ptr
, elfint
);
2321 /* add dynamic symbol table */
2322 s1
->dynsym
= new_symtab(s1
, ".dynsym", SHT_DYNSYM
, SHF_ALLOC
,
2324 ".hash", SHF_ALLOC
);
2325 dynstr
= s1
->dynsym
->link
;
2327 /* add dynamic section */
2328 dynamic
= new_section(s1
, ".dynamic", SHT_DYNAMIC
,
2329 SHF_ALLOC
| SHF_WRITE
);
2330 dynamic
->link
= dynstr
;
2331 dynamic
->sh_entsize
= sizeof(ElfW(Dyn
));
2334 s1
->plt
= new_section(s1
, ".plt", SHT_PROGBITS
,
2335 SHF_ALLOC
| SHF_EXECINSTR
);
2336 s1
->plt
->sh_entsize
= 4;
2340 if (file_type
== TCC_OUTPUT_EXE
) {
2341 bind_exe_dynsyms(s1
);
2343 if (s1
->nb_errors
) {
2348 bind_libs_dynsyms(s1
);
2349 } else /* shared library case: simply export all global symbols */
2350 export_global_syms(s1
);
2352 build_got_entries(s1
);
2354 /* add a list of needed dlls */
2355 for(i
= 0; i
< s1
->nb_loaded_dlls
; i
++) {
2356 DLLReference
*dllref
= s1
->loaded_dlls
[i
];
2357 if (dllref
->level
== 0)
2358 put_dt(dynamic
, DT_NEEDED
, put_elf_str(dynstr
, dllref
->name
));
2362 put_dt(dynamic
, DT_RPATH
, put_elf_str(dynstr
, s1
->rpath
));
2364 /* XXX: currently, since we do not handle PIC code, we
2365 must relocate the readonly segments */
2366 if (file_type
== TCC_OUTPUT_DLL
) {
2368 put_dt(dynamic
, DT_SONAME
, put_elf_str(dynstr
, s1
->soname
));
2369 put_dt(dynamic
, DT_TEXTREL
, 0);
2373 put_dt(dynamic
, DT_SYMBOLIC
, 0);
2375 /* add necessary space for other entries */
2376 dyninf
.dyn_rel_off
= dynamic
->data_offset
;
2377 dynamic
->data_offset
+= sizeof(ElfW(Dyn
)) * EXTRA_RELITEMS
;
2379 /* still need to build got entries in case of static link */
2380 build_got_entries(s1
);
2384 /* we add a section for symbols */
2385 strsec
= new_section(s1
, ".shstrtab", SHT_STRTAB
, 0);
2386 put_elf_str(strsec
, "");
2388 /* compute number of sections */
2389 shnum
= s1
->nb_sections
;
2391 /* this array is used to reorder sections in the output file */
2392 sec_order
= tcc_malloc(sizeof(int) * shnum
);
2395 /* compute number of program headers */
2398 case TCC_OUTPUT_OBJ
:
2401 case TCC_OUTPUT_EXE
:
2402 if (!s1
->static_link
)
2403 phnum
= 4 + HAVE_PHDR
;
2407 case TCC_OUTPUT_DLL
:
2412 /* Allocate strings for section names */
2413 alloc_sec_names(s1
, file_type
, strsec
);
2415 /* allocate program segment headers */
2416 phdr
= tcc_mallocz(phnum
* sizeof(ElfW(Phdr
)));
2418 /* compute section to program header mapping */
2419 file_offset
= layout_sections(s1
, phdr
, phnum
, interp
, &dyninf
, sec_order
);
2421 /* Fill remaining program header and finalize relocation related to dynamic
2424 fill_unloadable_phdr(phdr
, phnum
, interp
, dynamic
);
2426 dyninf
.dynamic
= dynamic
;
2427 dyninf
.dynstr
= dynstr
;
2429 fill_dynamic(s1
, &dyninf
);
2431 /* put in GOT the dynamic section address and relocate PLT */
2432 put32(s1
->got
->data
, dynamic
->sh_addr
);
2433 if (file_type
== TCC_OUTPUT_EXE
2434 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
2435 || file_type
== TCC_OUTPUT_DLL
2440 /* relocate symbols in .dynsym now that final addresses are known */
2441 for_each_elem(s1
->dynsym
, 1, sym
, ElfW(Sym
)) {
2442 /* relocate to PLT if symbol corresponds to a PLT entry */
2443 if (sym
->st_shndx
== SHN_UNDEF
) {
2445 sym
->st_value
+= s1
->plt
->sh_addr
;
2446 } else if (sym
->st_shndx
< SHN_LORESERVE
) {
2447 /* do symbol relocation */
2448 sym
->st_value
+= s1
->sections
[sym
->st_shndx
]->sh_addr
;
2454 /* if building executable or DLL, then relocate each section
2455 except the GOT which is already relocated */
2456 if (file_type
!= TCC_OUTPUT_OBJ
) {
2457 ret
= final_sections_reloc(s1
);
2462 /* Perform relocation to GOT or PLTÂ entries */
2463 if (file_type
== TCC_OUTPUT_EXE
&& s1
->static_link
)
2466 /* Create the ELF file with name 'filename' */
2467 ret
= tcc_write_elf_file(s1
, filename
, phnum
, phdr
, file_offset
, sec_order
);
2469 tcc_free(s1
->symtab_to_dynsym
);
2470 tcc_free(sec_order
);
2472 tcc_free(s1
->sym_attrs
);
2473 s1
->sym_attrs
= NULL
;
2477 LIBTCCAPI
int tcc_output_file(TCCState
*s
, const char *filename
)
2480 #ifdef TCC_TARGET_PE
2481 if (s
->output_type
!= TCC_OUTPUT_OBJ
) {
2482 ret
= pe_output_file(s
, filename
);
2485 ret
= elf_output_file(s
, filename
);
2489 static void *load_data(int fd
, unsigned long file_offset
, unsigned long size
)
2493 data
= tcc_malloc(size
);
2494 lseek(fd
, file_offset
, SEEK_SET
);
2495 read(fd
, data
, size
);
2499 typedef struct SectionMergeInfo
{
2500 Section
*s
; /* corresponding existing section */
2501 unsigned long offset
; /* offset of the new section in the existing section */
2502 uint8_t new_section
; /* true if section 's' was added */
2503 uint8_t link_once
; /* true if link once section */
2506 /* load an object file and merge it with current files */
2507 /* XXX: handle correctly stab (debug) info */
2508 ST_FUNC
int tcc_load_object_file(TCCState
*s1
,
2509 int fd
, unsigned long file_offset
)
2512 ElfW(Shdr
) *shdr
, *sh
;
2513 int size
, i
, j
, offset
, offseti
, nb_syms
, sym_index
, ret
;
2514 unsigned char *strsec
, *strtab
;
2515 int *old_to_new_syms
;
2516 char *sh_name
, *name
;
2517 SectionMergeInfo
*sm_table
, *sm
;
2518 ElfW(Sym
) *sym
, *symtab
;
2525 stab_index
= stabstr_index
= 0;
2527 if (read(fd
, &ehdr
, sizeof(ehdr
)) != sizeof(ehdr
))
2529 if (ehdr
.e_ident
[0] != ELFMAG0
||
2530 ehdr
.e_ident
[1] != ELFMAG1
||
2531 ehdr
.e_ident
[2] != ELFMAG2
||
2532 ehdr
.e_ident
[3] != ELFMAG3
)
2534 /* test if object file */
2535 if (ehdr
.e_type
!= ET_REL
)
2537 /* test CPU specific stuff */
2538 if (ehdr
.e_ident
[5] != ELFDATA2LSB
||
2539 ehdr
.e_machine
!= EM_TCC_TARGET
) {
2541 tcc_error_noabort("invalid object file");
2545 shdr
= load_data(fd
, file_offset
+ ehdr
.e_shoff
,
2546 sizeof(ElfW(Shdr
)) * ehdr
.e_shnum
);
2547 sm_table
= tcc_mallocz(sizeof(SectionMergeInfo
) * ehdr
.e_shnum
);
2549 /* load section names */
2550 sh
= &shdr
[ehdr
.e_shstrndx
];
2551 strsec
= load_data(fd
, file_offset
+ sh
->sh_offset
, sh
->sh_size
);
2553 /* load symtab and strtab */
2554 old_to_new_syms
= NULL
;
2558 for(i
= 1; i
< ehdr
.e_shnum
; i
++) {
2560 if (sh
->sh_type
== SHT_SYMTAB
) {
2562 tcc_error_noabort("object must contain only one symtab");
2567 nb_syms
= sh
->sh_size
/ sizeof(ElfW(Sym
));
2568 symtab
= load_data(fd
, file_offset
+ sh
->sh_offset
, sh
->sh_size
);
2569 sm_table
[i
].s
= symtab_section
;
2571 /* now load strtab */
2572 sh
= &shdr
[sh
->sh_link
];
2573 strtab
= load_data(fd
, file_offset
+ sh
->sh_offset
, sh
->sh_size
);
2577 /* now examine each section and try to merge its content with the
2579 for(i
= 1; i
< ehdr
.e_shnum
; i
++) {
2580 /* no need to examine section name strtab */
2581 if (i
== ehdr
.e_shstrndx
)
2584 sh_name
= (char *) strsec
+ sh
->sh_name
;
2585 /* ignore sections types we do not handle */
2586 if (sh
->sh_type
!= SHT_PROGBITS
&&
2587 sh
->sh_type
!= SHT_RELX
&&
2589 sh
->sh_type
!= SHT_ARM_EXIDX
&&
2591 sh
->sh_type
!= SHT_NOBITS
&&
2592 sh
->sh_type
!= SHT_PREINIT_ARRAY
&&
2593 sh
->sh_type
!= SHT_INIT_ARRAY
&&
2594 sh
->sh_type
!= SHT_FINI_ARRAY
&&
2595 strcmp(sh_name
, ".stabstr")
2598 if (sh
->sh_addralign
< 1)
2599 sh
->sh_addralign
= 1;
2600 /* find corresponding section, if any */
2601 for(j
= 1; j
< s1
->nb_sections
;j
++) {
2602 s
= s1
->sections
[j
];
2603 if (!strcmp(s
->name
, sh_name
)) {
2604 if (!strncmp(sh_name
, ".gnu.linkonce",
2605 sizeof(".gnu.linkonce") - 1)) {
2606 /* if a 'linkonce' section is already present, we
2607 do not add it again. It is a little tricky as
2608 symbols can still be defined in
2610 sm_table
[i
].link_once
= 1;
2617 /* not found: create new section */
2618 s
= new_section(s1
, sh_name
, sh
->sh_type
, sh
->sh_flags
);
2619 /* take as much info as possible from the section. sh_link and
2620 sh_info will be updated later */
2621 s
->sh_addralign
= sh
->sh_addralign
;
2622 s
->sh_entsize
= sh
->sh_entsize
;
2623 sm_table
[i
].new_section
= 1;
2625 if (sh
->sh_type
!= s
->sh_type
) {
2626 tcc_error_noabort("invalid section type");
2630 /* align start of section */
2631 offset
= s
->data_offset
;
2633 if (0 == strcmp(sh_name
, ".stab")) {
2637 if (0 == strcmp(sh_name
, ".stabstr")) {
2642 size
= sh
->sh_addralign
- 1;
2643 offset
= (offset
+ size
) & ~size
;
2644 if (sh
->sh_addralign
> s
->sh_addralign
)
2645 s
->sh_addralign
= sh
->sh_addralign
;
2646 s
->data_offset
= offset
;
2648 sm_table
[i
].offset
= offset
;
2650 /* concatenate sections */
2652 if (sh
->sh_type
!= SHT_NOBITS
) {
2654 lseek(fd
, file_offset
+ sh
->sh_offset
, SEEK_SET
);
2655 ptr
= section_ptr_add(s
, size
);
2656 read(fd
, ptr
, size
);
2658 s
->data_offset
+= size
;
2663 /* gr relocate stab strings */
2664 if (stab_index
&& stabstr_index
) {
2667 s
= sm_table
[stab_index
].s
;
2668 a
= (Stab_Sym
*)(s
->data
+ sm_table
[stab_index
].offset
);
2669 b
= (Stab_Sym
*)(s
->data
+ s
->data_offset
);
2670 o
= sm_table
[stabstr_index
].offset
;
2672 a
->n_strx
+= o
, a
++;
2675 /* second short pass to update sh_link and sh_info fields of new
2677 for(i
= 1; i
< ehdr
.e_shnum
; i
++) {
2679 if (!s
|| !sm_table
[i
].new_section
)
2682 if (sh
->sh_link
> 0)
2683 s
->link
= sm_table
[sh
->sh_link
].s
;
2684 if (sh
->sh_type
== SHT_RELX
) {
2685 s
->sh_info
= sm_table
[sh
->sh_info
].s
->sh_num
;
2686 /* update backward link */
2687 s1
->sections
[s
->sh_info
]->reloc
= s
;
2692 /* resolve symbols */
2693 old_to_new_syms
= tcc_mallocz(nb_syms
* sizeof(int));
2696 for(i
= 1; i
< nb_syms
; i
++, sym
++) {
2697 if (sym
->st_shndx
!= SHN_UNDEF
&&
2698 sym
->st_shndx
< SHN_LORESERVE
) {
2699 sm
= &sm_table
[sym
->st_shndx
];
2700 if (sm
->link_once
) {
2701 /* if a symbol is in a link once section, we use the
2702 already defined symbol. It is very important to get
2703 correct relocations */
2704 if (ELFW(ST_BIND
)(sym
->st_info
) != STB_LOCAL
) {
2705 name
= (char *) strtab
+ sym
->st_name
;
2706 sym_index
= find_elf_sym(symtab_section
, name
);
2708 old_to_new_syms
[i
] = sym_index
;
2712 /* if no corresponding section added, no need to add symbol */
2715 /* convert section number */
2716 sym
->st_shndx
= sm
->s
->sh_num
;
2718 sym
->st_value
+= sm
->offset
;
2721 name
= (char *) strtab
+ sym
->st_name
;
2722 sym_index
= add_elf_sym(symtab_section
, sym
->st_value
, sym
->st_size
,
2723 sym
->st_info
, sym
->st_other
,
2724 sym
->st_shndx
, name
);
2725 old_to_new_syms
[i
] = sym_index
;
2728 /* third pass to patch relocation entries */
2729 for(i
= 1; i
< ehdr
.e_shnum
; i
++) {
2734 offset
= sm_table
[i
].offset
;
2735 switch(s
->sh_type
) {
2737 /* take relocation offset information */
2738 offseti
= sm_table
[sh
->sh_info
].offset
;
2739 for_each_elem(s
, (offset
/ sizeof(*rel
)), rel
, ElfW_Rel
) {
2742 /* convert symbol index */
2743 type
= ELFW(R_TYPE
)(rel
->r_info
);
2744 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
2745 /* NOTE: only one symtab assumed */
2746 if (sym_index
>= nb_syms
)
2748 sym_index
= old_to_new_syms
[sym_index
];
2749 /* ignore link_once in rel section. */
2750 if (!sym_index
&& !sm
->link_once
2751 #ifdef TCC_TARGET_ARM
2752 && type
!= R_ARM_V4BX
2756 tcc_error_noabort("Invalid relocation entry [%2d] '%s' @ %.8x",
2757 i
, strsec
+ sh
->sh_name
, rel
->r_offset
);
2760 rel
->r_info
= ELFW(R_INFO
)(sym_index
, type
);
2761 /* offset the relocation offset */
2762 rel
->r_offset
+= offseti
;
2763 #ifdef TCC_TARGET_ARM
2764 /* Jumps and branches from a Thumb code to a PLT entry need
2765 special handling since PLT entries are ARM code.
2766 Unconditional bl instructions referencing PLT entries are
2767 handled by converting these instructions into blx
2768 instructions. Other case of instructions referencing a PLT
2769 entry require to add a Thumb stub before the PLT entry to
2770 switch to ARM mode. We set bit plt_thumb_stub of the
2771 attribute of a symbol to indicate such a case. */
2772 if (type
== R_ARM_THM_JUMP24
)
2773 alloc_sym_attr(s1
, sym_index
)->plt_thumb_stub
= 1;
2786 tcc_free(old_to_new_syms
);
2793 typedef struct ArchiveHeader
{
2794 char ar_name
[16]; /* name of this member */
2795 char ar_date
[12]; /* file mtime */
2796 char ar_uid
[6]; /* owner uid; printed as decimal */
2797 char ar_gid
[6]; /* owner gid; printed as decimal */
2798 char ar_mode
[8]; /* file mode, printed as octal */
2799 char ar_size
[10]; /* file size, printed as decimal */
2800 char ar_fmag
[2]; /* should contain ARFMAG */
2803 static int get_be32(const uint8_t *b
)
2805 return b
[3] | (b
[2] << 8) | (b
[1] << 16) | (b
[0] << 24);
2808 /* load only the objects which resolve undefined symbols */
2809 static int tcc_load_alacarte(TCCState
*s1
, int fd
, int size
)
2811 int i
, bound
, nsyms
, sym_index
, off
, ret
;
2813 const char *ar_names
, *p
;
2814 const uint8_t *ar_index
;
2817 data
= tcc_malloc(size
);
2818 if (read(fd
, data
, size
) != size
)
2820 nsyms
= get_be32(data
);
2821 ar_index
= data
+ 4;
2822 ar_names
= (char *) ar_index
+ nsyms
* 4;
2826 for(p
= ar_names
, i
= 0; i
< nsyms
; i
++, p
+= strlen(p
)+1) {
2827 sym_index
= find_elf_sym(symtab_section
, p
);
2829 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
2830 if(sym
->st_shndx
== SHN_UNDEF
) {
2831 off
= get_be32(ar_index
+ i
* 4) + sizeof(ArchiveHeader
);
2833 lseek(fd
, off
, SEEK_SET
);
2834 if(tcc_load_object_file(s1
, fd
, off
) < 0) {
2849 /* load a '.a' file */
2850 ST_FUNC
int tcc_load_archive(TCCState
*s1
, int fd
)
2857 unsigned long file_offset
;
2859 /* skip magic which was already checked */
2860 read(fd
, magic
, sizeof(magic
));
2863 len
= read(fd
, &hdr
, sizeof(hdr
));
2866 if (len
!= sizeof(hdr
)) {
2867 tcc_error_noabort("invalid archive");
2870 memcpy(ar_size
, hdr
.ar_size
, sizeof(hdr
.ar_size
));
2871 ar_size
[sizeof(hdr
.ar_size
)] = '\0';
2872 size
= strtol(ar_size
, NULL
, 0);
2873 memcpy(ar_name
, hdr
.ar_name
, sizeof(hdr
.ar_name
));
2874 for(i
= sizeof(hdr
.ar_name
) - 1; i
>= 0; i
--) {
2875 if (ar_name
[i
] != ' ')
2878 ar_name
[i
+ 1] = '\0';
2879 file_offset
= lseek(fd
, 0, SEEK_CUR
);
2881 size
= (size
+ 1) & ~1;
2882 if (!strcmp(ar_name
, "/")) {
2883 /* coff symbol table : we handle it */
2884 if(s1
->alacarte_link
)
2885 return tcc_load_alacarte(s1
, fd
, size
);
2886 } else if (!strcmp(ar_name
, "//") ||
2887 !strcmp(ar_name
, "__.SYMDEF") ||
2888 !strcmp(ar_name
, "__.SYMDEF/") ||
2889 !strcmp(ar_name
, "ARFILENAMES/")) {
2890 /* skip symbol table or archive names */
2892 if (tcc_load_object_file(s1
, fd
, file_offset
) < 0)
2895 lseek(fd
, file_offset
+ size
, SEEK_SET
);
2900 #ifndef TCC_TARGET_PE
2901 /* load a DLL and all referenced DLLs. 'level = 0' means that the DLL
2902 is referenced by the user (so it should be added as DT_NEEDED in
2903 the generated ELF file) */
2904 ST_FUNC
int tcc_load_dll(TCCState
*s1
, int fd
, const char *filename
, int level
)
2907 ElfW(Shdr
) *shdr
, *sh
, *sh1
;
2908 int i
, j
, nb_syms
, nb_dts
, sym_bind
, ret
;
2909 ElfW(Sym
) *sym
, *dynsym
;
2910 ElfW(Dyn
) *dt
, *dynamic
;
2911 unsigned char *dynstr
;
2912 const char *name
, *soname
;
2913 DLLReference
*dllref
;
2915 read(fd
, &ehdr
, sizeof(ehdr
));
2917 /* test CPU specific stuff */
2918 if (ehdr
.e_ident
[5] != ELFDATA2LSB
||
2919 ehdr
.e_machine
!= EM_TCC_TARGET
) {
2920 tcc_error_noabort("bad architecture");
2925 shdr
= load_data(fd
, ehdr
.e_shoff
, sizeof(ElfW(Shdr
)) * ehdr
.e_shnum
);
2927 /* load dynamic section and dynamic symbols */
2931 dynsym
= NULL
; /* avoid warning */
2932 dynstr
= NULL
; /* avoid warning */
2933 for(i
= 0, sh
= shdr
; i
< ehdr
.e_shnum
; i
++, sh
++) {
2934 switch(sh
->sh_type
) {
2936 nb_dts
= sh
->sh_size
/ sizeof(ElfW(Dyn
));
2937 dynamic
= load_data(fd
, sh
->sh_offset
, sh
->sh_size
);
2940 nb_syms
= sh
->sh_size
/ sizeof(ElfW(Sym
));
2941 dynsym
= load_data(fd
, sh
->sh_offset
, sh
->sh_size
);
2942 sh1
= &shdr
[sh
->sh_link
];
2943 dynstr
= load_data(fd
, sh1
->sh_offset
, sh1
->sh_size
);
2950 /* compute the real library name */
2951 soname
= tcc_basename(filename
);
2953 for(i
= 0, dt
= dynamic
; i
< nb_dts
; i
++, dt
++) {
2954 if (dt
->d_tag
== DT_SONAME
) {
2955 soname
= (char *) dynstr
+ dt
->d_un
.d_val
;
2959 /* if the dll is already loaded, do not load it */
2960 for(i
= 0; i
< s1
->nb_loaded_dlls
; i
++) {
2961 dllref
= s1
->loaded_dlls
[i
];
2962 if (!strcmp(soname
, dllref
->name
)) {
2963 /* but update level if needed */
2964 if (level
< dllref
->level
)
2965 dllref
->level
= level
;
2971 /* add the dll and its level */
2972 dllref
= tcc_mallocz(sizeof(DLLReference
) + strlen(soname
));
2973 dllref
->level
= level
;
2974 strcpy(dllref
->name
, soname
);
2975 dynarray_add((void ***)&s1
->loaded_dlls
, &s1
->nb_loaded_dlls
, dllref
);
2977 /* add dynamic symbols in dynsym_section */
2978 for(i
= 1, sym
= dynsym
+ 1; i
< nb_syms
; i
++, sym
++) {
2979 sym_bind
= ELFW(ST_BIND
)(sym
->st_info
);
2980 if (sym_bind
== STB_LOCAL
)
2982 name
= (char *) dynstr
+ sym
->st_name
;
2983 add_elf_sym(s1
->dynsymtab_section
, sym
->st_value
, sym
->st_size
,
2984 sym
->st_info
, sym
->st_other
, sym
->st_shndx
, name
);
2987 /* load all referenced DLLs */
2988 for(i
= 0, dt
= dynamic
; i
< nb_dts
; i
++, dt
++) {
2991 name
= (char *) dynstr
+ dt
->d_un
.d_val
;
2992 for(j
= 0; j
< s1
->nb_loaded_dlls
; j
++) {
2993 dllref
= s1
->loaded_dlls
[j
];
2994 if (!strcmp(name
, dllref
->name
))
2995 goto already_loaded
;
2997 if (tcc_add_dll(s1
, name
, AFF_REFERENCED_DLL
) < 0) {
2998 tcc_error_noabort("referenced dll '%s' not found", name
);
3015 #define LD_TOK_NAME 256
3016 #define LD_TOK_EOF (-1)
3018 /* return next ld script token */
3019 static int ld_next(TCCState
*s1
, char *name
, int name_size
)
3037 file
->buf_ptr
= parse_comment(file
->buf_ptr
);
3038 ch
= file
->buf_ptr
[0];
3046 /* case 'a' ... 'z': */
3073 /* case 'A' ... 'z': */
3108 if (!((ch
>= 'a' && ch
<= 'z') ||
3109 (ch
>= 'A' && ch
<= 'Z') ||
3110 (ch
>= '0' && ch
<= '9') ||
3111 strchr("/.-_+=$:\\,~", ch
)))
3113 if ((q
- name
) < name_size
- 1) {
3132 static int ld_add_file(TCCState
*s1
, const char filename
[])
3136 ret
= tcc_add_file_internal(s1
, filename
, 0);
3138 ret
= tcc_add_dll(s1
, filename
, 0);
3142 static inline int new_undef_syms(void)
3145 ret
= new_undef_sym
;
3150 static int ld_add_file_list(TCCState
*s1
, const char *cmd
, int as_needed
)
3152 char filename
[1024], libname
[1024];
3153 int t
, group
, nblibs
= 0, ret
= 0;
3156 group
= !strcmp(cmd
, "GROUP");
3159 t
= ld_next(s1
, filename
, sizeof(filename
));
3162 t
= ld_next(s1
, filename
, sizeof(filename
));
3165 if (t
== LD_TOK_EOF
) {
3166 tcc_error_noabort("unexpected end of file");
3168 goto lib_parse_error
;
3169 } else if (t
== ')') {
3171 } else if (t
== '-') {
3172 t
= ld_next(s1
, filename
, sizeof(filename
));
3173 if ((t
!= LD_TOK_NAME
) || (filename
[0] != 'l')) {
3174 tcc_error_noabort("library name expected");
3176 goto lib_parse_error
;
3178 pstrcpy(libname
, sizeof libname
, &filename
[1]);
3179 if (s1
->static_link
) {
3180 snprintf(filename
, sizeof filename
, "lib%s.a", libname
);
3182 snprintf(filename
, sizeof filename
, "lib%s.so", libname
);
3184 } else if (t
!= LD_TOK_NAME
) {
3185 tcc_error_noabort("filename expected");
3187 goto lib_parse_error
;
3189 if (!strcmp(filename
, "AS_NEEDED")) {
3190 ret
= ld_add_file_list(s1
, cmd
, 1);
3192 goto lib_parse_error
;
3194 /* TODO: Implement AS_NEEDED support. Ignore it for now */
3196 ret
= ld_add_file(s1
, filename
);
3198 goto lib_parse_error
;
3200 /* Add the filename *and* the libname to avoid future conversions */
3201 dynarray_add((void ***) &libs
, &nblibs
, tcc_strdup(filename
));
3202 if (libname
[0] != '\0')
3203 dynarray_add((void ***) &libs
, &nblibs
, tcc_strdup(libname
));
3207 t
= ld_next(s1
, filename
, sizeof(filename
));
3209 t
= ld_next(s1
, filename
, sizeof(filename
));
3212 if (group
&& !as_needed
) {
3213 while (new_undef_syms()) {
3216 for (i
= 0; i
< nblibs
; i
++)
3217 ld_add_file(s1
, libs
[i
]);
3221 dynarray_reset(&libs
, &nblibs
);
3225 /* interpret a subset of GNU ldscripts to handle the dummy libc.so
3227 ST_FUNC
int tcc_load_ldscript(TCCState
*s1
)
3230 char filename
[1024];
3233 ch
= file
->buf_ptr
[0];
3236 t
= ld_next(s1
, cmd
, sizeof(cmd
));
3237 if (t
== LD_TOK_EOF
)
3239 else if (t
!= LD_TOK_NAME
)
3241 if (!strcmp(cmd
, "INPUT") ||
3242 !strcmp(cmd
, "GROUP")) {
3243 ret
= ld_add_file_list(s1
, cmd
, 0);
3246 } else if (!strcmp(cmd
, "OUTPUT_FORMAT") ||
3247 !strcmp(cmd
, "TARGET")) {
3248 /* ignore some commands */
3249 t
= ld_next(s1
, cmd
, sizeof(cmd
));
3253 t
= ld_next(s1
, filename
, sizeof(filename
));
3254 if (t
== LD_TOK_EOF
) {
3255 tcc_error_noabort("unexpected end of file");
3257 } else if (t
== ')') {
3267 #endif /* !TCC_TARGET_PE */