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 #ifdef TCC_TARGET_X86_64
24 #define ElfW_Rel ElfW(Rela)
25 #define SHT_RELX SHT_RELA
26 #define REL_SECTION_FMT ".rela%s"
27 /* x86-64 requires PLT for DLLs */
28 #define TCC_OUTPUT_DLL_WITH_PLT
30 #define ElfW_Rel ElfW(Rel)
31 #define SHT_RELX SHT_REL
32 #define REL_SECTION_FMT ".rel%s"
35 static int new_undef_sym
= 0; /* Is there a new undefined sym since last new_undef_sym() */
37 /* XXX: DLL with PLT would only work with x86-64 for now */
38 //#define TCC_OUTPUT_DLL_WITH_PLT
40 ST_FUNC
int put_elf_str(Section
*s
, const char *sym
)
45 len
= strlen(sym
) + 1;
46 offset
= s
->data_offset
;
47 ptr
= section_ptr_add(s
, len
);
48 memcpy(ptr
, sym
, len
);
52 /* elf symbol hashing function */
53 static unsigned long elf_hash(const unsigned char *name
)
55 unsigned long h
= 0, g
;
58 h
= (h
<< 4) + *name
++;
67 /* rebuild hash table of section s */
68 /* NOTE: we do factorize the hash table code to go faster */
69 static void rebuild_hash(Section
*s
, unsigned int nb_buckets
)
72 int *ptr
, *hash
, nb_syms
, sym_index
, h
;
75 strtab
= s
->link
->data
;
76 nb_syms
= s
->data_offset
/ sizeof(ElfW(Sym
));
78 s
->hash
->data_offset
= 0;
79 ptr
= section_ptr_add(s
->hash
, (2 + nb_buckets
+ nb_syms
) * sizeof(int));
84 memset(hash
, 0, (nb_buckets
+ 1) * sizeof(int));
85 ptr
+= nb_buckets
+ 1;
87 sym
= (ElfW(Sym
) *)s
->data
+ 1;
88 for(sym_index
= 1; sym_index
< nb_syms
; sym_index
++) {
89 if (ELFW(ST_BIND
)(sym
->st_info
) != STB_LOCAL
) {
90 h
= elf_hash(strtab
+ sym
->st_name
) % nb_buckets
;
101 /* return the symbol number */
102 ST_FUNC
int put_elf_sym(Section
*s
, uplong value
, unsigned long size
,
103 int info
, int other
, int shndx
, const char *name
)
105 int name_offset
, sym_index
;
110 sym
= section_ptr_add(s
, sizeof(ElfW(Sym
)));
112 name_offset
= put_elf_str(s
->link
, name
);
115 /* XXX: endianness */
116 sym
->st_name
= name_offset
;
117 sym
->st_value
= value
;
120 sym
->st_other
= other
;
121 sym
->st_shndx
= shndx
;
122 sym_index
= sym
- (ElfW(Sym
) *)s
->data
;
126 ptr
= section_ptr_add(hs
, sizeof(int));
127 base
= (int *)hs
->data
;
128 /* only add global or weak symbols */
129 if (ELFW(ST_BIND
)(info
) != STB_LOCAL
) {
130 /* add another hashing entry */
132 h
= elf_hash(name
) % nbuckets
;
134 base
[2 + h
] = sym_index
;
136 /* we resize the hash table */
137 hs
->nb_hashed_syms
++;
138 if (hs
->nb_hashed_syms
> 2 * nbuckets
) {
139 rebuild_hash(s
, 2 * nbuckets
);
149 /* find global ELF symbol 'name' and return its index. Return 0 if not
151 ST_FUNC
int find_elf_sym(Section
*s
, const char *name
)
155 int nbuckets
, sym_index
, h
;
161 nbuckets
= ((int *)hs
->data
)[0];
162 h
= elf_hash(name
) % nbuckets
;
163 sym_index
= ((int *)hs
->data
)[2 + h
];
164 while (sym_index
!= 0) {
165 sym
= &((ElfW(Sym
) *)s
->data
)[sym_index
];
166 name1
= s
->link
->data
+ sym
->st_name
;
167 if (!strcmp(name
, name1
))
169 sym_index
= ((int *)hs
->data
)[2 + nbuckets
+ sym_index
];
174 /* return elf symbol value, signal error if 'err' is nonzero */
175 static void *get_elf_sym_addr(TCCState
*s
, const char *name
, int err
)
180 sym_index
= find_elf_sym(symtab_section
, name
);
181 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
182 if (!sym_index
|| sym
->st_shndx
== SHN_UNDEF
) {
184 error("%s not defined", name
);
187 return (void*)(uplong
)sym
->st_value
;
190 /* return elf symbol value */
191 LIBTCCAPI
void *tcc_get_symbol(TCCState
*s
, const char *name
)
193 return get_elf_sym_addr(s
, name
, 0);
196 /* return elf symbol value or error */
197 ST_FUNC
void *tcc_get_symbol_err(TCCState
*s
, const char *name
)
199 return get_elf_sym_addr(s
, name
, 1);
202 /* add an elf symbol : check if it is already defined and patch
203 it. Return symbol index. NOTE that sh_num can be SHN_UNDEF. */
204 ST_FUNC
int add_elf_sym(Section
*s
, uplong value
, unsigned long size
,
205 int info
, int other
, int sh_num
, const char *name
)
208 int sym_bind
, sym_index
, sym_type
, esym_bind
;
209 unsigned char sym_vis
, esym_vis
, new_vis
;
211 sym_bind
= ELFW(ST_BIND
)(info
);
212 sym_type
= ELFW(ST_TYPE
)(info
);
213 sym_vis
= ELFW(ST_VISIBILITY
)(other
);
215 if (sym_bind
!= STB_LOCAL
) {
216 /* we search global or weak symbols */
217 sym_index
= find_elf_sym(s
, name
);
220 esym
= &((ElfW(Sym
) *)s
->data
)[sym_index
];
221 if (esym
->st_shndx
!= SHN_UNDEF
) {
222 esym_bind
= ELFW(ST_BIND
)(esym
->st_info
);
223 /* propagate the most constraining visibility */
224 /* STV_DEFAULT(0)<STV_PROTECTED(3)<STV_HIDDEN(2)<STV_INTERNAL(1) */
225 esym_vis
= ELFW(ST_VISIBILITY
)(esym
->st_other
);
226 if (esym_vis
== STV_DEFAULT
) {
228 } else if (sym_vis
== STV_DEFAULT
) {
231 new_vis
= (esym_vis
< sym_vis
) ? esym_vis
: sym_vis
;
233 esym
->st_other
= (esym
->st_other
& ~ELFW(ST_VISIBILITY
)(-1))
235 other
= esym
->st_other
; /* in case we have to patch esym */
236 if (sh_num
== SHN_UNDEF
) {
237 /* ignore adding of undefined symbol if the
238 corresponding symbol is already defined */
239 } else if (sym_bind
== STB_GLOBAL
&& esym_bind
== STB_WEAK
) {
240 /* global overrides weak, so patch */
242 } else if (sym_bind
== STB_WEAK
&& esym_bind
== STB_GLOBAL
) {
243 /* weak is ignored if already global */
244 } else if (sym_vis
== STV_HIDDEN
|| sym_vis
== STV_INTERNAL
) {
245 /* ignore hidden symbols after */
246 } else if (esym
->st_shndx
== SHN_COMMON
247 && (sh_num
< SHN_LORESERVE
|| sh_num
== SHN_COMMON
)) {
248 /* gr: Happens with 'tcc ... -static tcctest.c' on e.g. Ubuntu 6.01
249 No idea if this is the correct solution ... */
251 } else if (s
== tcc_state
->dynsymtab_section
) {
252 /* we accept that two DLL define the same symbol */
255 printf("new_bind=%x new_shndx=%x new_vis=%x old_bind=%x old_shndx=%x old_vis=%x\n",
256 sym_bind
, sh_num
, new_vis
, esym_bind
, esym
->st_shndx
, esym_vis
);
258 error_noabort("'%s' defined twice", name
);
262 esym
->st_info
= ELFW(ST_INFO
)(sym_bind
, sym_type
);
263 esym
->st_shndx
= sh_num
;
265 esym
->st_value
= value
;
266 esym
->st_size
= size
;
267 esym
->st_other
= other
;
271 sym_index
= put_elf_sym(s
, value
, size
,
272 ELFW(ST_INFO
)(sym_bind
, sym_type
), other
,
279 ST_FUNC
void put_elf_reloc(Section
*symtab
, Section
*s
, unsigned long offset
,
280 int type
, int symbol
)
288 /* if no relocation section, create it */
289 snprintf(buf
, sizeof(buf
), REL_SECTION_FMT
, s
->name
);
290 /* if the symtab is allocated, then we consider the relocation
292 sr
= new_section(tcc_state
, buf
, SHT_RELX
, symtab
->sh_flags
);
293 sr
->sh_entsize
= sizeof(ElfW_Rel
);
295 sr
->sh_info
= s
->sh_num
;
298 rel
= section_ptr_add(sr
, sizeof(ElfW_Rel
));
299 rel
->r_offset
= offset
;
300 rel
->r_info
= ELFW(R_INFO
)(symbol
, type
);
301 #ifdef TCC_TARGET_X86_64
306 /* put stab debug information */
308 ST_FUNC
void put_stabs(const char *str
, int type
, int other
, int desc
,
313 sym
= section_ptr_add(stab_section
, sizeof(Stab_Sym
));
315 sym
->n_strx
= put_elf_str(stabstr_section
, str
);
320 sym
->n_other
= other
;
322 sym
->n_value
= value
;
325 ST_FUNC
void put_stabs_r(const char *str
, int type
, int other
, int desc
,
326 unsigned long value
, Section
*sec
, int sym_index
)
328 put_stabs(str
, type
, other
, desc
, value
);
329 put_elf_reloc(symtab_section
, stab_section
,
330 stab_section
->data_offset
- sizeof(unsigned int),
331 R_DATA_32
, sym_index
);
334 ST_FUNC
void put_stabn(int type
, int other
, int desc
, int value
)
336 put_stabs(NULL
, type
, other
, desc
, value
);
339 ST_FUNC
void put_stabd(int type
, int other
, int desc
)
341 put_stabs(NULL
, type
, other
, desc
, 0);
344 /* In an ELF file symbol table, the local symbols must appear below
345 the global and weak ones. Since TCC cannot sort it while generating
346 the code, we must do it after. All the relocation tables are also
347 modified to take into account the symbol table sorting */
348 static void sort_syms(TCCState
*s1
, Section
*s
)
350 int *old_to_new_syms
;
354 ElfW_Rel
*rel
, *rel_end
;
358 nb_syms
= s
->data_offset
/ sizeof(ElfW(Sym
));
359 new_syms
= tcc_malloc(nb_syms
* sizeof(ElfW(Sym
)));
360 old_to_new_syms
= tcc_malloc(nb_syms
* sizeof(int));
362 /* first pass for local symbols */
363 p
= (ElfW(Sym
) *)s
->data
;
365 for(i
= 0; i
< nb_syms
; i
++) {
366 if (ELFW(ST_BIND
)(p
->st_info
) == STB_LOCAL
) {
367 old_to_new_syms
[i
] = q
- new_syms
;
372 /* save the number of local symbols in section header */
373 s
->sh_info
= q
- new_syms
;
375 /* then second pass for non local symbols */
376 p
= (ElfW(Sym
) *)s
->data
;
377 for(i
= 0; i
< nb_syms
; i
++) {
378 if (ELFW(ST_BIND
)(p
->st_info
) != STB_LOCAL
) {
379 old_to_new_syms
[i
] = q
- new_syms
;
385 /* we copy the new symbols to the old */
386 memcpy(s
->data
, new_syms
, nb_syms
* sizeof(ElfW(Sym
)));
389 /* now we modify all the relocations */
390 for(i
= 1; i
< s1
->nb_sections
; i
++) {
391 sr
= s1
->sections
[i
];
392 if (sr
->sh_type
== SHT_RELX
&& sr
->link
== s
) {
393 rel_end
= (ElfW_Rel
*)(sr
->data
+ sr
->data_offset
);
394 for(rel
= (ElfW_Rel
*)sr
->data
;
397 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
398 type
= ELFW(R_TYPE
)(rel
->r_info
);
399 sym_index
= old_to_new_syms
[sym_index
];
400 rel
->r_info
= ELFW(R_INFO
)(sym_index
, type
);
405 tcc_free(old_to_new_syms
);
408 /* relocate common symbols in the .bss section */
409 ST_FUNC
void relocate_common_syms(void)
411 ElfW(Sym
) *sym
, *sym_end
;
412 unsigned long offset
, align
;
414 sym_end
= (ElfW(Sym
) *)(symtab_section
->data
+ symtab_section
->data_offset
);
415 for(sym
= (ElfW(Sym
) *)symtab_section
->data
+ 1;
418 if (sym
->st_shndx
== SHN_COMMON
) {
420 align
= sym
->st_value
;
421 offset
= bss_section
->data_offset
;
422 offset
= (offset
+ align
- 1) & -align
;
423 sym
->st_value
= offset
;
424 sym
->st_shndx
= bss_section
->sh_num
;
425 offset
+= sym
->st_size
;
426 bss_section
->data_offset
= offset
;
431 /* relocate symbol table, resolve undefined symbols if do_resolve is
432 true and output error if undefined symbol. */
433 ST_FUNC
void relocate_syms(TCCState
*s1
, int do_resolve
)
435 ElfW(Sym
) *sym
, *esym
, *sym_end
;
436 int sym_bind
, sh_num
, sym_index
;
439 sym_end
= (ElfW(Sym
) *)(symtab_section
->data
+ symtab_section
->data_offset
);
440 for(sym
= (ElfW(Sym
) *)symtab_section
->data
+ 1;
443 sh_num
= sym
->st_shndx
;
444 if (sh_num
== SHN_UNDEF
) {
445 name
= strtab_section
->data
+ sym
->st_name
;
447 #if !defined TCC_TARGET_PE || !defined _WIN32
449 name
= symtab_section
->link
->data
+ sym
->st_name
;
450 addr
= resolve_sym(s1
, name
);
452 sym
->st_value
= (uplong
)addr
;
456 } else if (s1
->dynsym
) {
457 /* if dynamic symbol exist, then use it */
458 sym_index
= find_elf_sym(s1
->dynsym
, name
);
460 esym
= &((ElfW(Sym
) *)s1
->dynsym
->data
)[sym_index
];
461 sym
->st_value
= esym
->st_value
;
465 /* XXX: _fp_hw seems to be part of the ABI, so we ignore
467 if (!strcmp(name
, "_fp_hw"))
469 /* only weak symbols are accepted to be undefined. Their
471 sym_bind
= ELFW(ST_BIND
)(sym
->st_info
);
472 if (sym_bind
== STB_WEAK
) {
475 error_noabort("undefined symbol '%s'", name
);
477 } else if (sh_num
< SHN_LORESERVE
) {
478 /* add section base */
479 sym
->st_value
+= s1
->sections
[sym
->st_shndx
]->sh_addr
;
485 #ifndef TCC_TARGET_PE
486 #ifdef TCC_TARGET_X86_64
487 #define JMP_TABLE_ENTRY_SIZE 14
488 static uplong
add_jmp_table(TCCState
*s1
, uplong val
)
490 char *p
= s1
->runtime_plt_and_got
+ s1
->runtime_plt_and_got_offset
;
491 s1
->runtime_plt_and_got_offset
+= JMP_TABLE_ENTRY_SIZE
;
496 *(uplong
*)(p
+ 6) = val
;
500 static uplong
add_got_table(TCCState
*s1
, uplong val
)
502 uplong
*p
= (uplong
*)(s1
->runtime_plt_and_got
+ s1
->runtime_plt_and_got_offset
);
503 s1
->runtime_plt_and_got_offset
+= sizeof(uplong
);
507 #elif defined TCC_TARGET_ARM
508 #define JMP_TABLE_ENTRY_SIZE 8
509 static int add_jmp_table(TCCState
*s1
, int val
)
511 uint32_t *p
= (uint32_t *)(s1
->runtime_plt_and_got
+ s1
->runtime_plt_and_got_offset
);
512 s1
->runtime_plt_and_got_offset
+= JMP_TABLE_ENTRY_SIZE
;
513 /* ldr pc, [pc, #-4] */
521 /* relocate a given section (CPU dependent) */
522 ST_FUNC
void relocate_section(TCCState
*s1
, Section
*s
)
525 ElfW_Rel
*rel
, *rel_end
, *qrel
;
530 #if defined TCC_TARGET_I386 || defined TCC_TARGET_X86_64
535 rel_end
= (ElfW_Rel
*)(sr
->data
+ sr
->data_offset
);
536 qrel
= (ElfW_Rel
*)sr
->data
;
540 ptr
= s
->data
+ rel
->r_offset
;
542 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
543 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
545 #ifdef TCC_TARGET_X86_64
546 /* XXX: not tested */
547 val
+= rel
->r_addend
;
549 type
= ELFW(R_TYPE
)(rel
->r_info
);
550 addr
= s
->sh_addr
+ rel
->r_offset
;
554 #if defined(TCC_TARGET_I386)
556 if (s1
->output_type
== TCC_OUTPUT_DLL
) {
557 esym_index
= s1
->symtab_to_dynsym
[sym_index
];
558 qrel
->r_offset
= rel
->r_offset
;
560 qrel
->r_info
= ELFW(R_INFO
)(esym_index
, R_386_32
);
564 qrel
->r_info
= ELFW(R_INFO
)(0, R_386_RELATIVE
);
571 if (s1
->output_type
== TCC_OUTPUT_DLL
) {
573 esym_index
= s1
->symtab_to_dynsym
[sym_index
];
575 qrel
->r_offset
= rel
->r_offset
;
576 qrel
->r_info
= ELFW(R_INFO
)(esym_index
, R_386_PC32
);
581 *(int *)ptr
+= val
- addr
;
584 *(int *)ptr
+= val
- addr
;
591 *(int *)ptr
+= s1
->got
->sh_addr
- addr
;
594 *(int *)ptr
+= val
- s1
->got
->sh_addr
;
597 /* we load the got offset */
598 *(int *)ptr
+= s1
->got_offsets
[sym_index
];
601 if (s1
->output_format
!= TCC_OUTPUT_FORMAT_BINARY
) {
603 error("can only produce 16-bit binary files");
605 *(short *)ptr
+= val
;
608 if (s1
->output_format
!= TCC_OUTPUT_FORMAT_BINARY
)
610 *(short *)ptr
+= val
- addr
;
612 #elif defined(TCC_TARGET_ARM)
619 x
= (*(int *)ptr
)&0xffffff;
620 (*(int *)ptr
) &= 0xff000000;
625 #ifndef TCC_TARGET_PE
626 if((x
& 3) != 0 || x
>= 0x4000000 || x
< -0x4000000)
627 if (s1
->output_type
== TCC_OUTPUT_MEMORY
)
628 x
+= add_jmp_table(s1
, val
) - val
; /* add veneer */
630 if((x
& 3) != 0 || x
>= 0x4000000 || x
< -0x4000000)
631 error("can't relocate value at %x",addr
);
640 x
= (*(int *)ptr
) & 0x7fffffff;
641 (*(int *)ptr
) &= 0x80000000;
644 if((x
^(x
>>1))&0x40000000)
645 error("can't relocate value at %x",addr
);
646 (*(int *)ptr
) |= x
& 0x7fffffff;
651 case R_ARM_BASE_PREL
:
652 *(int *)ptr
+= s1
->got
->sh_addr
- addr
;
655 *(int *)ptr
+= val
- s1
->got
->sh_addr
;
658 /* we load the got offset */
659 *(int *)ptr
+= s1
->got_offsets
[sym_index
];
664 /* trade Thumb support for ARMv4 support */
665 if ((0x0ffffff0 & *(int*)ptr
) == 0x012FFF10)
666 *(int*)ptr
^= 0xE12FFF10 ^ 0xE1A0F000; /* BX Rm -> MOV PC, Rm */
669 fprintf(stderr
,"FIXME: handle reloc type %x at %lx [%.8x] to %lx\n",
670 type
,addr
,(unsigned int)(long)ptr
,val
);
672 #elif defined(TCC_TARGET_C67)
680 /* put the low 16 bits of the absolute address */
681 // add to what is already there
683 orig
= ((*(int *)(ptr
)) >> 7) & 0xffff;
684 orig
|= (((*(int *)(ptr
+4)) >> 7) & 0xffff) << 16;
686 //patch both at once - assumes always in pairs Low - High
688 *(int *) ptr
= (*(int *) ptr
& (~(0xffff << 7)) ) | (((val
+orig
) & 0xffff) << 7);
689 *(int *)(ptr
+4) = (*(int *)(ptr
+4) & (~(0xffff << 7)) ) | ((((val
+orig
)>>16) & 0xffff) << 7);
695 fprintf(stderr
,"FIXME: handle reloc type %x at %lx [%.8x] to %lx\n",
696 type
,addr
,(unsigned int)(long)ptr
, val
);
698 #elif defined(TCC_TARGET_X86_64)
700 if (s1
->output_type
== TCC_OUTPUT_DLL
) {
701 qrel
->r_info
= ELFW(R_INFO
)(0, R_X86_64_RELATIVE
);
702 qrel
->r_addend
= *(long long *)ptr
+ val
;
705 *(long long *)ptr
+= val
;
709 if (s1
->output_type
== TCC_OUTPUT_DLL
) {
710 /* XXX: this logic may depend on TCC's codegen
711 now TCC uses R_X86_64_32 even for a 64bit pointer */
712 qrel
->r_info
= ELFW(R_INFO
)(0, R_X86_64_RELATIVE
);
713 qrel
->r_addend
= *(int *)ptr
+ val
;
718 case R_X86_64_PC32
: {
720 if (s1
->output_type
== TCC_OUTPUT_DLL
) {
722 esym_index
= s1
->symtab_to_dynsym
[sym_index
];
724 qrel
->r_offset
= rel
->r_offset
;
725 qrel
->r_info
= ELFW(R_INFO
)(esym_index
, R_X86_64_PC32
);
726 qrel
->r_addend
= *(int *)ptr
;
731 diff
= (long long)val
- addr
;
732 if (diff
<= -2147483647 || diff
> 2147483647) {
733 #ifndef TCC_TARGET_PE
734 /* XXX: naive support for over 32bit jump */
735 if (s1
->output_type
== TCC_OUTPUT_MEMORY
) {
736 val
= add_jmp_table(s1
, val
);
740 if (diff
<= -2147483647 || diff
> 2147483647) {
741 error("internal error: relocation failed");
748 *(int *)ptr
+= val
- addr
;
750 case R_X86_64_GLOB_DAT
:
751 case R_X86_64_JUMP_SLOT
:
754 case R_X86_64_GOTPCREL
:
755 #ifndef TCC_TARGET_PE
756 if (s1
->output_type
== TCC_OUTPUT_MEMORY
) {
757 val
= add_got_table(s1
, val
- rel
->r_addend
) + rel
->r_addend
;
758 *(int *)ptr
+= val
- addr
;
762 *(int *)ptr
+= (s1
->got
->sh_addr
- addr
+
763 s1
->got_offsets
[sym_index
] - 4);
765 case R_X86_64_GOTTPOFF
:
766 *(int *)ptr
+= val
- s1
->got
->sh_addr
;
769 /* we load the got offset */
770 *(int *)ptr
+= s1
->got_offsets
[sym_index
];
773 #error unsupported processor
777 /* if the relocation is allocated, we change its symbol table */
778 if (sr
->sh_flags
& SHF_ALLOC
)
779 sr
->link
= s1
->dynsym
;
782 /* relocate relocation table in 'sr' */
783 static void relocate_rel(TCCState
*s1
, Section
*sr
)
786 ElfW_Rel
*rel
, *rel_end
;
788 s
= s1
->sections
[sr
->sh_info
];
789 rel_end
= (ElfW_Rel
*)(sr
->data
+ sr
->data_offset
);
790 for(rel
= (ElfW_Rel
*)sr
->data
;
793 rel
->r_offset
+= s
->sh_addr
;
797 /* count the number of dynamic relocations so that we can reserve
799 static int prepare_dynamic_rel(TCCState
*s1
, Section
*sr
)
801 ElfW_Rel
*rel
, *rel_end
;
802 int sym_index
, esym_index
, type
, count
;
805 rel_end
= (ElfW_Rel
*)(sr
->data
+ sr
->data_offset
);
806 for(rel
= (ElfW_Rel
*)sr
->data
; rel
< rel_end
; rel
++) {
807 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
808 type
= ELFW(R_TYPE
)(rel
->r_info
);
810 #if defined(TCC_TARGET_I386)
812 #elif defined(TCC_TARGET_X86_64)
819 #if defined(TCC_TARGET_I386)
821 #elif defined(TCC_TARGET_X86_64)
824 esym_index
= s1
->symtab_to_dynsym
[sym_index
];
833 /* allocate the section */
834 sr
->sh_flags
|= SHF_ALLOC
;
835 sr
->sh_size
= count
* sizeof(ElfW_Rel
);
840 static void put_got_offset(TCCState
*s1
, int index
, unsigned long val
)
845 if (index
>= s1
->nb_got_offsets
) {
846 /* find immediately bigger power of 2 and reallocate array */
850 tab
= tcc_realloc(s1
->got_offsets
, n
* sizeof(unsigned long));
852 error("memory full");
853 s1
->got_offsets
= tab
;
854 memset(s1
->got_offsets
+ s1
->nb_got_offsets
, 0,
855 (n
- s1
->nb_got_offsets
) * sizeof(unsigned long));
856 s1
->nb_got_offsets
= n
;
858 s1
->got_offsets
[index
] = val
;
861 /* XXX: suppress that */
862 static void put32(unsigned char *p
, uint32_t val
)
870 #if defined(TCC_TARGET_I386) || defined(TCC_TARGET_ARM) || \
871 defined(TCC_TARGET_X86_64)
872 static uint32_t get32(unsigned char *p
)
874 return p
[0] | (p
[1] << 8) | (p
[2] << 16) | (p
[3] << 24);
878 static void build_got(TCCState
*s1
)
882 /* if no got, then create it */
883 s1
->got
= new_section(s1
, ".got", SHT_PROGBITS
, SHF_ALLOC
| SHF_WRITE
);
884 s1
->got
->sh_entsize
= 4;
885 add_elf_sym(symtab_section
, 0, 4, ELFW(ST_INFO
)(STB_GLOBAL
, STT_OBJECT
),
886 0, s1
->got
->sh_num
, "_GLOBAL_OFFSET_TABLE_");
887 ptr
= section_ptr_add(s1
->got
, 3 * PTR_SIZE
);
889 /* keep space for _DYNAMIC pointer, if present */
891 /* two dummy got entries */
895 /* keep space for _DYNAMIC pointer, if present */
898 /* two dummy got entries */
906 /* put a got entry corresponding to a symbol in symtab_section. 'size'
907 and 'info' can be modifed if more precise info comes from the DLL */
908 static void put_got_entry(TCCState
*s1
,
909 int reloc_type
, unsigned long size
, int info
,
915 unsigned long offset
;
921 /* if a got entry already exists for that symbol, no need to add one */
922 if (sym_index
< s1
->nb_got_offsets
&&
923 s1
->got_offsets
[sym_index
] != 0)
926 put_got_offset(s1
, sym_index
, s1
->got
->data_offset
);
929 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
930 name
= symtab_section
->link
->data
+ sym
->st_name
;
931 offset
= sym
->st_value
;
932 #if defined(TCC_TARGET_I386) || defined(TCC_TARGET_X86_64)
934 #ifdef TCC_TARGET_X86_64
944 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
947 /* if we build a DLL, we add a %ebx offset */
948 if (s1
->output_type
== TCC_OUTPUT_DLL
)
954 /* add a PLT entry */
956 if (plt
->data_offset
== 0) {
957 /* first plt entry */
958 p
= section_ptr_add(plt
, 16);
959 p
[0] = 0xff; /* pushl got + PTR_SIZE */
961 put32(p
+ 2, PTR_SIZE
);
962 p
[6] = 0xff; /* jmp *(got + PTR_SIZE * 2) */
964 put32(p
+ 8, PTR_SIZE
* 2);
967 p
= section_ptr_add(plt
, 16);
968 p
[0] = 0xff; /* jmp *(got + x) */
970 put32(p
+ 2, s1
->got
->data_offset
);
971 p
[6] = 0x68; /* push $xxx */
972 put32(p
+ 7, (plt
->data_offset
- 32) >> 1);
973 p
[11] = 0xe9; /* jmp plt_start */
974 put32(p
+ 12, -(plt
->data_offset
));
976 /* the symbol is modified so that it will be relocated to
978 #if !defined(TCC_OUTPUT_DLL_WITH_PLT)
979 if (s1
->output_type
== TCC_OUTPUT_EXE
)
981 offset
= plt
->data_offset
- 16;
983 #elif defined(TCC_TARGET_ARM)
984 if (reloc_type
== R_ARM_JUMP_SLOT
) {
988 /* if we build a DLL, we add a %ebx offset */
989 if (s1
->output_type
== TCC_OUTPUT_DLL
)
990 error("DLLs unimplemented!");
992 /* add a PLT entry */
994 if (plt
->data_offset
== 0) {
995 /* first plt entry */
996 p
= section_ptr_add(plt
, 16);
997 put32(p
, 0xe52de004);
998 put32(p
+ 4, 0xe59fe010);
999 put32(p
+ 8, 0xe08fe00e);
1000 put32(p
+ 12, 0xe5bef008);
1003 p
= section_ptr_add(plt
, 16);
1004 put32(p
, 0xe59fc004);
1005 put32(p
+4, 0xe08fc00c);
1006 put32(p
+8, 0xe59cf000);
1007 put32(p
+12, s1
->got
->data_offset
);
1009 /* the symbol is modified so that it will be relocated to
1011 if (s1
->output_type
== TCC_OUTPUT_EXE
)
1012 offset
= plt
->data_offset
- 16;
1014 #elif defined(TCC_TARGET_C67)
1015 error("C67 got not implemented");
1017 #error unsupported CPU
1019 index
= put_elf_sym(s1
->dynsym
, offset
,
1020 size
, info
, 0, sym
->st_shndx
, name
);
1021 /* put a got entry */
1022 put_elf_reloc(s1
->dynsym
, s1
->got
,
1023 s1
->got
->data_offset
,
1026 ptr
= section_ptr_add(s1
->got
, PTR_SIZE
);
1030 /* build GOT and PLT entries */
1031 ST_FUNC
void build_got_entries(TCCState
*s1
)
1033 Section
*s
, *symtab
;
1034 ElfW_Rel
*rel
, *rel_end
;
1036 int i
, type
, reloc_type
, sym_index
;
1038 for(i
= 1; i
< s1
->nb_sections
; i
++) {
1039 s
= s1
->sections
[i
];
1040 if (s
->sh_type
!= SHT_RELX
)
1042 /* no need to handle got relocations */
1043 if (s
->link
!= symtab_section
)
1046 rel_end
= (ElfW_Rel
*)(s
->data
+ s
->data_offset
);
1047 for(rel
= (ElfW_Rel
*)s
->data
;
1050 type
= ELFW(R_TYPE
)(rel
->r_info
);
1052 #if defined(TCC_TARGET_I386)
1059 if (type
== R_386_GOT32
|| type
== R_386_PLT32
) {
1060 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
1061 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
1062 /* look at the symbol got offset. If none, then add one */
1063 if (type
== R_386_GOT32
)
1064 reloc_type
= R_386_GLOB_DAT
;
1066 reloc_type
= R_386_JMP_SLOT
;
1067 put_got_entry(s1
, reloc_type
, sym
->st_size
, sym
->st_info
,
1071 #elif defined(TCC_TARGET_ARM)
1072 case R_ARM_GOT_BREL
:
1073 case R_ARM_GOTOFF32
:
1074 case R_ARM_BASE_PREL
:
1078 if (type
== R_ARM_GOT_BREL
|| type
== R_ARM_PLT32
) {
1079 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
1080 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
1081 /* look at the symbol got offset. If none, then add one */
1082 if (type
== R_ARM_GOT_BREL
)
1083 reloc_type
= R_ARM_GLOB_DAT
;
1085 reloc_type
= R_ARM_JUMP_SLOT
;
1086 put_got_entry(s1
, reloc_type
, sym
->st_size
, sym
->st_info
,
1090 #elif defined(TCC_TARGET_C67)
1097 if (type
== R_C60_GOT32
|| type
== R_C60_PLT32
) {
1098 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
1099 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
1100 /* look at the symbol got offset. If none, then add one */
1101 if (type
== R_C60_GOT32
)
1102 reloc_type
= R_C60_GLOB_DAT
;
1104 reloc_type
= R_C60_JMP_SLOT
;
1105 put_got_entry(s1
, reloc_type
, sym
->st_size
, sym
->st_info
,
1109 #elif defined(TCC_TARGET_X86_64)
1110 case R_X86_64_GOT32
:
1111 case R_X86_64_GOTTPOFF
:
1112 case R_X86_64_GOTPCREL
:
1113 case R_X86_64_PLT32
:
1116 if (type
== R_X86_64_GOT32
|| type
== R_X86_64_GOTPCREL
||
1117 type
== R_X86_64_PLT32
) {
1118 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
1119 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
1120 /* look at the symbol got offset. If none, then add one */
1121 if (type
== R_X86_64_GOT32
|| type
== R_X86_64_GOTPCREL
)
1122 reloc_type
= R_X86_64_GLOB_DAT
;
1124 reloc_type
= R_X86_64_JUMP_SLOT
;
1125 put_got_entry(s1
, reloc_type
, sym
->st_size
, sym
->st_info
,
1130 #error unsupported CPU
1139 ST_FUNC Section
*new_symtab(TCCState
*s1
,
1140 const char *symtab_name
, int sh_type
, int sh_flags
,
1141 const char *strtab_name
,
1142 const char *hash_name
, int hash_sh_flags
)
1144 Section
*symtab
, *strtab
, *hash
;
1145 int *ptr
, nb_buckets
;
1147 symtab
= new_section(s1
, symtab_name
, sh_type
, sh_flags
);
1148 symtab
->sh_entsize
= sizeof(ElfW(Sym
));
1149 strtab
= new_section(s1
, strtab_name
, SHT_STRTAB
, sh_flags
);
1150 put_elf_str(strtab
, "");
1151 symtab
->link
= strtab
;
1152 put_elf_sym(symtab
, 0, 0, 0, 0, 0, NULL
);
1156 hash
= new_section(s1
, hash_name
, SHT_HASH
, hash_sh_flags
);
1157 hash
->sh_entsize
= sizeof(int);
1158 symtab
->hash
= hash
;
1159 hash
->link
= symtab
;
1161 ptr
= section_ptr_add(hash
, (2 + nb_buckets
+ 1) * sizeof(int));
1162 ptr
[0] = nb_buckets
;
1164 memset(ptr
+ 2, 0, (nb_buckets
+ 1) * sizeof(int));
1168 /* put dynamic tag */
1169 static void put_dt(Section
*dynamic
, int dt
, unsigned long val
)
1172 dyn
= section_ptr_add(dynamic
, sizeof(ElfW(Dyn
)));
1174 dyn
->d_un
.d_val
= val
;
1177 static void add_init_array_defines(TCCState
*s1
, const char *section_name
)
1181 char sym_start
[1024];
1184 snprintf(sym_start
, sizeof(sym_start
), "__%s_start", section_name
+ 1);
1185 snprintf(sym_end
, sizeof(sym_end
), "__%s_end", section_name
+ 1);
1187 s
= find_section(s1
, section_name
);
1192 end_offset
= s
->data_offset
;
1195 add_elf_sym(symtab_section
,
1197 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1198 s
->sh_num
, sym_start
);
1199 add_elf_sym(symtab_section
,
1201 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1202 s
->sh_num
, sym_end
);
1205 ST_FUNC
void tcc_add_bcheck(TCCState
*s1
)
1207 #ifdef CONFIG_TCC_BCHECK
1209 Section
*init_section
;
1210 unsigned char *pinit
;
1213 if (0 == s1
->do_bounds_check
)
1216 /* XXX: add an object file to do that */
1217 ptr
= section_ptr_add(bounds_section
, sizeof(unsigned long));
1219 add_elf_sym(symtab_section
, 0, 0,
1220 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1221 bounds_section
->sh_num
, "__bounds_start");
1222 /* add bound check code */
1223 #ifndef TCC_TARGET_PE
1226 snprintf(buf
, sizeof(buf
), "%s/%s", s1
->tcc_lib_path
, "bcheck.o");
1227 tcc_add_file(s1
, buf
);
1230 #ifdef TCC_TARGET_I386
1231 if (s1
->output_type
!= TCC_OUTPUT_MEMORY
) {
1232 /* add 'call __bound_init()' in .init section */
1233 init_section
= find_section(s1
, ".init");
1234 pinit
= section_ptr_add(init_section
, 5);
1236 put32(pinit
+ 1, -4);
1237 sym_index
= find_elf_sym(symtab_section
, "__bound_init");
1238 put_elf_reloc(symtab_section
, init_section
,
1239 init_section
->data_offset
- 4, R_386_PC32
, sym_index
);
1245 /* add tcc runtime libraries */
1246 ST_FUNC
void tcc_add_runtime(TCCState
*s1
)
1251 if (!s1
->nostdlib
) {
1252 #ifdef CONFIG_USE_LIBGCC
1253 tcc_add_library(s1
, "c");
1254 tcc_add_file(s1
, CONFIG_SYSROOT
"/lib/libgcc_s.so.1");
1256 tcc_add_library(s1
, "c");
1257 #ifndef WITHOUT_LIBTCC
1260 snprintf(buf
, sizeof(buf
), "%s/%s", s1
->tcc_lib_path
, "libtcc1.a");
1261 tcc_add_file(s1
, buf
);
1266 /* add crt end if not memory output */
1267 if (s1
->output_type
!= TCC_OUTPUT_MEMORY
&& !s1
->nostdlib
) {
1268 tcc_add_file(s1
, CONFIG_TCC_CRT_PREFIX
"/crtn.o");
1272 /* add various standard linker symbols (must be done after the
1273 sections are filled (for example after allocating common
1275 ST_FUNC
void tcc_add_linker_symbols(TCCState
*s1
)
1281 add_elf_sym(symtab_section
,
1282 text_section
->data_offset
, 0,
1283 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1284 text_section
->sh_num
, "_etext");
1285 add_elf_sym(symtab_section
,
1286 data_section
->data_offset
, 0,
1287 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1288 data_section
->sh_num
, "_edata");
1289 add_elf_sym(symtab_section
,
1290 bss_section
->data_offset
, 0,
1291 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1292 bss_section
->sh_num
, "_end");
1293 /* horrible new standard ldscript defines */
1294 add_init_array_defines(s1
, ".preinit_array");
1295 add_init_array_defines(s1
, ".init_array");
1296 add_init_array_defines(s1
, ".fini_array");
1298 /* add start and stop symbols for sections whose name can be
1300 for(i
= 1; i
< s1
->nb_sections
; i
++) {
1301 s
= s1
->sections
[i
];
1302 if (s
->sh_type
== SHT_PROGBITS
&&
1303 (s
->sh_flags
& SHF_ALLOC
)) {
1307 /* check if section name can be expressed in C */
1313 if (!isid(ch
) && !isnum(ch
))
1317 snprintf(buf
, sizeof(buf
), "__start_%s", s
->name
);
1318 add_elf_sym(symtab_section
,
1320 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1322 snprintf(buf
, sizeof(buf
), "__stop_%s", s
->name
);
1323 add_elf_sym(symtab_section
,
1325 ELFW(ST_INFO
)(STB_GLOBAL
, STT_NOTYPE
), 0,
1332 /* name of ELF interpreter */
1333 #if defined __FreeBSD__
1334 static const char elf_interp
[] = "/libexec/ld-elf.so.1";
1335 #elif defined TCC_ARM_EABI
1336 static const char elf_interp
[] = "/lib/ld-linux.so.3";
1337 #elif defined(TCC_TARGET_X86_64)
1338 # if defined(TCC_TARGET_X86_64_CENTOS)
1339 static const char elf_interp
[] = "/lib64/ld-linux-x86-64.so.2";
1341 static const char elf_interp
[] = "/lib/ld-linux-x86-64.so.2";
1342 # endif /* TCC_TARGET_X86_64_CENTOS */
1343 #elif defined(TCC_UCLIBC)
1344 static const char elf_interp
[] = "/lib/ld-uClibc.so.0";
1346 static const char elf_interp
[] = "/lib/ld-linux.so.2";
1349 static void tcc_output_binary(TCCState
*s1
, FILE *f
,
1350 const int *section_order
)
1353 int i
, offset
, size
;
1356 for(i
=1;i
<s1
->nb_sections
;i
++) {
1357 s
= s1
->sections
[section_order
[i
]];
1358 if (s
->sh_type
!= SHT_NOBITS
&&
1359 (s
->sh_flags
& SHF_ALLOC
)) {
1360 while (offset
< s
->sh_offset
) {
1365 fwrite(s
->data
, 1, size
, f
);
1371 #if defined(__FreeBSD__)
1373 #define EXTRA_RELITEMS 14
1375 /* move the relocation value from .dynsym to .got */
1376 void patch_dynsym_undef(TCCState
*s1
, Section
*s
)
1378 uint32_t *gotd
= (void *)s1
->got
->data
;
1379 ElfW(Sym
) *sym
, *sym_end
;
1381 gotd
+= 3; // dummy entries in .got
1382 /* relocate symbols in .dynsym */
1383 sym_end
= (ElfW(Sym
) *)(s
->data
+ s
->data_offset
);
1384 for (sym
= (ElfW(Sym
) *)s
->data
+ 1; sym
< sym_end
; sym
++) {
1385 if (sym
->st_shndx
== SHN_UNDEF
) {
1386 *gotd
++ = sym
->st_value
+ 6; // XXX 6 is magic ?
1393 #define EXTRA_RELITEMS 9
1396 ST_FUNC
void fill_got_entry(TCCState
*s1
, ElfW_Rel
*rel
)
1398 int sym_index
= ELFW(R_SYM
) (rel
->r_info
);
1399 ElfW(Sym
) *sym
= &((ElfW(Sym
) *) symtab_section
->data
)[sym_index
];
1400 unsigned long offset
;
1402 if (sym_index
>= s1
->nb_got_offsets
)
1404 offset
= s1
->got_offsets
[sym_index
];
1405 section_reserve(s1
->got
, offset
+ PTR_SIZE
);
1406 #ifdef TCC_TARGET_X86_64
1407 /* only works for x86-64 */
1408 put32(s1
->got
->data
+ offset
, sym
->st_value
>> 32);
1410 put32(s1
->got
->data
+ offset
, sym
->st_value
& 0xffffffff);
1413 ST_FUNC
void fill_got(TCCState
*s1
)
1416 ElfW_Rel
*rel
, *rel_end
;
1419 for(i
= 1; i
< s1
->nb_sections
; i
++) {
1420 s
= s1
->sections
[i
];
1421 if (s
->sh_type
!= SHT_RELX
)
1423 /* no need to handle got relocations */
1424 if (s
->link
!= symtab_section
)
1426 rel_end
= (ElfW_Rel
*) (s
->data
+ s
->data_offset
);
1427 for(rel
= (ElfW_Rel
*) s
->data
; rel
< rel_end
; rel
++) {
1428 switch (ELFW(R_TYPE
) (rel
->r_info
)) {
1429 case R_X86_64_GOT32
:
1430 case R_X86_64_GOTPCREL
:
1431 case R_X86_64_PLT32
:
1432 fill_got_entry(s1
, rel
);
1440 /* output an ELF file */
1441 /* XXX: suppress unneeded sections */
1442 static int elf_output_file(TCCState
*s1
, const char *filename
)
1448 int shnum
, i
, phnum
, file_offset
, offset
, size
, j
, tmp
, sh_order_index
, k
;
1450 Section
*strsec
, *s
;
1451 ElfW(Shdr
) shdr
, *sh
;
1452 ElfW(Phdr
) *phdr
, *ph
;
1453 Section
*interp
, *dynamic
, *dynstr
;
1454 unsigned long saved_dynamic_data_offset
;
1456 int type
, file_type
;
1457 unsigned long rel_addr
, rel_size
;
1458 unsigned long bss_addr
, bss_size
;
1460 file_type
= s1
->output_type
;
1463 if (file_type
!= TCC_OUTPUT_OBJ
) {
1464 tcc_add_runtime(s1
);
1468 section_order
= NULL
;
1471 dynstr
= NULL
; /* avoid warning */
1472 saved_dynamic_data_offset
= 0; /* avoid warning */
1474 if (file_type
!= TCC_OUTPUT_OBJ
) {
1475 relocate_common_syms();
1477 tcc_add_linker_symbols(s1
);
1479 if (!s1
->static_link
) {
1481 int sym_index
, index
;
1482 ElfW(Sym
) *esym
, *sym_end
;
1484 if (file_type
== TCC_OUTPUT_EXE
) {
1486 /* allow override the dynamic loader */
1487 const char *elfint
= getenv("LD_SO");
1489 elfint
= elf_interp
;
1490 /* add interpreter section only if executable */
1491 interp
= new_section(s1
, ".interp", SHT_PROGBITS
, SHF_ALLOC
);
1492 interp
->sh_addralign
= 1;
1493 ptr
= section_ptr_add(interp
, 1+strlen(elfint
));
1494 strcpy(ptr
, elfint
);
1497 /* add dynamic symbol table */
1498 s1
->dynsym
= new_symtab(s1
, ".dynsym", SHT_DYNSYM
, SHF_ALLOC
,
1500 ".hash", SHF_ALLOC
);
1501 dynstr
= s1
->dynsym
->link
;
1503 /* add dynamic section */
1504 dynamic
= new_section(s1
, ".dynamic", SHT_DYNAMIC
,
1505 SHF_ALLOC
| SHF_WRITE
);
1506 dynamic
->link
= dynstr
;
1507 dynamic
->sh_entsize
= sizeof(ElfW(Dyn
));
1510 s1
->plt
= new_section(s1
, ".plt", SHT_PROGBITS
,
1511 SHF_ALLOC
| SHF_EXECINSTR
);
1512 s1
->plt
->sh_entsize
= 4;
1516 /* scan for undefined symbols and see if they are in the
1517 dynamic symbols. If a symbol STT_FUNC is found, then we
1518 add it in the PLT. If a symbol STT_OBJECT is found, we
1519 add it in the .bss section with a suitable relocation */
1520 sym_end
= (ElfW(Sym
) *)(symtab_section
->data
+
1521 symtab_section
->data_offset
);
1522 if (file_type
== TCC_OUTPUT_EXE
) {
1523 for(sym
= (ElfW(Sym
) *)symtab_section
->data
+ 1;
1526 if (sym
->st_shndx
== SHN_UNDEF
) {
1527 name
= symtab_section
->link
->data
+ sym
->st_name
;
1528 sym_index
= find_elf_sym(s1
->dynsymtab_section
, name
);
1530 esym
= &((ElfW(Sym
) *)s1
->dynsymtab_section
->data
)[sym_index
];
1531 type
= ELFW(ST_TYPE
)(esym
->st_info
);
1532 if (type
== STT_FUNC
) {
1533 put_got_entry(s1
, R_JMP_SLOT
, esym
->st_size
,
1535 sym
- (ElfW(Sym
) *)symtab_section
->data
);
1536 } else if (type
== STT_OBJECT
) {
1537 unsigned long offset
;
1538 ElfW(Sym
) *dynsym
, *dynsym_end
;
1539 offset
= bss_section
->data_offset
;
1540 /* XXX: which alignment ? */
1541 offset
= (offset
+ 16 - 1) & -16;
1542 index
= put_elf_sym(s1
->dynsym
, offset
, esym
->st_size
,
1544 bss_section
->sh_num
, name
);
1545 /* Ensure symbol aliases (that is, symbols with
1546 the same st_value) resolve to the same
1547 address in program .bss or .data section. */
1548 dynsym_end
= (ElfW(Sym
) *)
1549 (s1
->dynsymtab_section
->data
+
1550 s1
->dynsymtab_section
->data_offset
);
1551 for(dynsym
= (ElfW(Sym
) *)s1
->dynsymtab_section
->data
+ 1;
1552 dynsym
< dynsym_end
; dynsym
++) {
1553 if (dynsym
->st_value
== esym
->st_value
) {
1555 dynname
= s1
->dynsymtab_section
->link
->data
1557 put_elf_sym(s1
->dynsym
, offset
,
1560 bss_section
->sh_num
,
1564 put_elf_reloc(s1
->dynsym
, bss_section
,
1565 offset
, R_COPY
, index
);
1566 offset
+= esym
->st_size
;
1567 bss_section
->data_offset
= offset
;
1570 /* STB_WEAK undefined symbols are accepted */
1571 /* XXX: _fp_hw seems to be part of the ABI, so we ignore
1573 if (ELFW(ST_BIND
)(sym
->st_info
) == STB_WEAK
||
1574 !strcmp(name
, "_fp_hw")) {
1576 error_noabort("undefined symbol '%s'", name
);
1579 } else if (s1
->rdynamic
&&
1580 ELFW(ST_BIND
)(sym
->st_info
) != STB_LOCAL
) {
1581 /* if -rdynamic option, then export all non
1583 name
= symtab_section
->link
->data
+ sym
->st_name
;
1584 put_elf_sym(s1
->dynsym
, sym
->st_value
, sym
->st_size
,
1586 sym
->st_shndx
, name
);
1593 /* now look at unresolved dynamic symbols and export
1594 corresponding symbol */
1595 sym_end
= (ElfW(Sym
) *)(s1
->dynsymtab_section
->data
+
1596 s1
->dynsymtab_section
->data_offset
);
1597 for(esym
= (ElfW(Sym
) *)s1
->dynsymtab_section
->data
+ 1;
1600 if (esym
->st_shndx
== SHN_UNDEF
) {
1601 name
= s1
->dynsymtab_section
->link
->data
+ esym
->st_name
;
1602 sym_index
= find_elf_sym(symtab_section
, name
);
1604 /* XXX: avoid adding a symbol if already
1605 present because of -rdynamic ? */
1606 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
1607 put_elf_sym(s1
->dynsym
, sym
->st_value
, sym
->st_size
,
1609 sym
->st_shndx
, name
);
1611 if (ELFW(ST_BIND
)(esym
->st_info
) == STB_WEAK
) {
1612 /* weak symbols can stay undefined */
1614 warning("undefined dynamic symbol '%s'", name
);
1621 /* shared library case : we simply export all the global symbols */
1622 nb_syms
= symtab_section
->data_offset
/ sizeof(ElfW(Sym
));
1623 s1
->symtab_to_dynsym
= tcc_mallocz(sizeof(int) * nb_syms
);
1624 for(sym
= (ElfW(Sym
) *)symtab_section
->data
+ 1;
1627 if (ELFW(ST_BIND
)(sym
->st_info
) != STB_LOCAL
) {
1628 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
1629 if (ELFW(ST_TYPE
)(sym
->st_info
) == STT_FUNC
&&
1630 sym
->st_shndx
== SHN_UNDEF
) {
1631 put_got_entry(s1
, R_JMP_SLOT
, sym
->st_size
,
1633 sym
- (ElfW(Sym
) *)symtab_section
->data
);
1635 else if (ELFW(ST_TYPE
)(sym
->st_info
) == STT_OBJECT
) {
1636 put_got_entry(s1
, R_X86_64_GLOB_DAT
, sym
->st_size
,
1638 sym
- (ElfW(Sym
) *)symtab_section
->data
);
1643 name
= symtab_section
->link
->data
+ sym
->st_name
;
1644 index
= put_elf_sym(s1
->dynsym
, sym
->st_value
, sym
->st_size
,
1646 sym
->st_shndx
, name
);
1647 s1
->symtab_to_dynsym
[sym
-
1648 (ElfW(Sym
) *)symtab_section
->data
] =
1655 build_got_entries(s1
);
1657 /* add a list of needed dlls */
1658 for(i
= 0; i
< s1
->nb_loaded_dlls
; i
++) {
1659 DLLReference
*dllref
= s1
->loaded_dlls
[i
];
1660 if (dllref
->level
== 0)
1661 put_dt(dynamic
, DT_NEEDED
, put_elf_str(dynstr
, dllref
->name
));
1665 put_dt(dynamic
, DT_RPATH
, put_elf_str(dynstr
, s1
->rpath
));
1667 /* XXX: currently, since we do not handle PIC code, we
1668 must relocate the readonly segments */
1669 if (file_type
== TCC_OUTPUT_DLL
) {
1671 put_dt(dynamic
, DT_SONAME
, put_elf_str(dynstr
, s1
->soname
));
1672 put_dt(dynamic
, DT_TEXTREL
, 0);
1676 put_dt(dynamic
, DT_SYMBOLIC
, 0);
1678 /* add necessary space for other entries */
1679 saved_dynamic_data_offset
= dynamic
->data_offset
;
1680 dynamic
->data_offset
+= sizeof(ElfW(Dyn
)) * EXTRA_RELITEMS
;
1682 /* still need to build got entries in case of static link */
1683 build_got_entries(s1
);
1687 memset(&ehdr
, 0, sizeof(ehdr
));
1689 /* we add a section for symbols */
1690 strsec
= new_section(s1
, ".shstrtab", SHT_STRTAB
, 0);
1691 put_elf_str(strsec
, "");
1693 /* compute number of sections */
1694 shnum
= s1
->nb_sections
;
1696 /* this array is used to reorder sections in the output file */
1697 section_order
= tcc_malloc(sizeof(int) * shnum
);
1698 section_order
[0] = 0;
1701 /* compute number of program headers */
1704 case TCC_OUTPUT_OBJ
:
1707 case TCC_OUTPUT_EXE
:
1708 if (!s1
->static_link
)
1709 phnum
= 4 + HAVE_PHDR
;
1713 case TCC_OUTPUT_DLL
:
1718 /* allocate strings for section names and decide if an unallocated
1719 section should be output */
1720 /* NOTE: the strsec section comes last, so its size is also
1722 for(i
= 1; i
< s1
->nb_sections
; i
++) {
1723 s
= s1
->sections
[i
];
1724 s
->sh_name
= put_elf_str(strsec
, s
->name
);
1726 printf("section: f=%08x t=%08x i=%08x %s %s\n",
1731 s
->reloc
? s
->reloc
->name
: "n"
1734 /* when generating a DLL, we include relocations but we may
1736 if (file_type
== TCC_OUTPUT_DLL
&&
1737 s
->sh_type
== SHT_RELX
&&
1738 !(s
->sh_flags
& SHF_ALLOC
)) {
1739 /* //gr: avoid bogus relocs for empty (debug) sections */
1740 if (s1
->sections
[s
->sh_info
]->sh_flags
& SHF_ALLOC
)
1741 prepare_dynamic_rel(s1
, s
);
1742 else if (s1
->do_debug
)
1743 s
->sh_size
= s
->data_offset
;
1744 } else if (s1
->do_debug
||
1745 file_type
== TCC_OUTPUT_OBJ
||
1746 (s
->sh_flags
& SHF_ALLOC
) ||
1747 i
== (s1
->nb_sections
- 1)) {
1748 /* we output all sections if debug or object file */
1749 s
->sh_size
= s
->data_offset
;
1753 /* allocate program segment headers */
1754 phdr
= tcc_mallocz(phnum
* sizeof(ElfW(Phdr
)));
1756 if (s1
->output_format
== TCC_OUTPUT_FORMAT_ELF
) {
1757 file_offset
= sizeof(ElfW(Ehdr
)) + phnum
* sizeof(ElfW(Phdr
));
1762 /* compute section to program header mapping */
1763 if (s1
->has_text_addr
) {
1764 int a_offset
, p_offset
;
1765 addr
= s1
->text_addr
;
1766 /* we ensure that (addr % ELF_PAGE_SIZE) == file_offset %
1768 a_offset
= addr
& (s1
->section_align
- 1);
1769 p_offset
= file_offset
& (s1
->section_align
- 1);
1770 if (a_offset
< p_offset
)
1771 a_offset
+= s1
->section_align
;
1772 file_offset
+= (a_offset
- p_offset
);
1774 if (file_type
== TCC_OUTPUT_DLL
)
1777 addr
= ELF_START_ADDR
;
1778 /* compute address after headers */
1779 addr
+= (file_offset
& (s1
->section_align
- 1));
1782 /* dynamic relocation table information, for .dynamic section */
1786 bss_addr
= bss_size
= 0;
1787 /* leave one program header for the program interpreter */
1790 ph
+= 1 + HAVE_PHDR
;
1792 for(j
= 0; j
< 2; j
++) {
1793 ph
->p_type
= PT_LOAD
;
1795 ph
->p_flags
= PF_R
| PF_X
;
1797 ph
->p_flags
= PF_R
| PF_W
;
1798 ph
->p_align
= s1
->section_align
;
1800 /* we do the following ordering: interp, symbol tables,
1801 relocations, progbits, nobits */
1802 /* XXX: do faster and simpler sorting */
1803 for(k
= 0; k
< 5; k
++) {
1804 for(i
= 1; i
< s1
->nb_sections
; i
++) {
1805 s
= s1
->sections
[i
];
1806 /* compute if section should be included */
1808 if ((s
->sh_flags
& (SHF_ALLOC
| SHF_WRITE
)) !=
1812 if ((s
->sh_flags
& (SHF_ALLOC
| SHF_WRITE
)) !=
1813 (SHF_ALLOC
| SHF_WRITE
))
1819 } else if (s
->sh_type
== SHT_DYNSYM
||
1820 s
->sh_type
== SHT_STRTAB
||
1821 s
->sh_type
== SHT_HASH
) {
1824 } else if (s
->sh_type
== SHT_RELX
) {
1827 } else if (s
->sh_type
== SHT_NOBITS
) {
1834 section_order
[sh_order_index
++] = i
;
1836 /* section matches: we align it and add its size */
1838 addr
= (addr
+ s
->sh_addralign
- 1) &
1839 ~(s
->sh_addralign
- 1);
1840 file_offset
+= addr
- tmp
;
1841 s
->sh_offset
= file_offset
;
1844 /* update program header infos */
1845 if (ph
->p_offset
== 0) {
1846 ph
->p_offset
= file_offset
;
1848 ph
->p_paddr
= ph
->p_vaddr
;
1850 /* update dynamic relocation infos */
1851 if (s
->sh_type
== SHT_RELX
) {
1852 #if defined(__FreeBSD__)
1853 if (!strcmp(strsec
->data
+ s
->sh_name
, ".rel.got")) { // rel_size == 0) {
1855 rel_size
+= s
->sh_size
; // XXX only first rel.
1857 if (!strcmp(strsec
->data
+ s
->sh_name
, ".rel.bss")) { // rel_size == 0) {
1859 bss_size
= s
->sh_size
; // XXX only first rel.
1864 rel_size
+= s
->sh_size
;
1868 if (s
->sh_type
!= SHT_NOBITS
)
1869 file_offset
+= s
->sh_size
;
1872 ph
->p_filesz
= file_offset
- ph
->p_offset
;
1873 ph
->p_memsz
= addr
- ph
->p_vaddr
;
1876 if (s1
->output_format
== TCC_OUTPUT_FORMAT_ELF
) {
1877 /* if in the middle of a page, we duplicate the page in
1878 memory so that one copy is RX and the other is RW */
1879 if ((addr
& (s1
->section_align
- 1)) != 0)
1880 addr
+= s1
->section_align
;
1882 addr
= (addr
+ s1
->section_align
- 1) & ~(s1
->section_align
- 1);
1883 file_offset
= (file_offset
+ s1
->section_align
- 1) &
1884 ~(s1
->section_align
- 1);
1889 /* if interpreter, then add corresponing program header */
1893 #if defined(__FreeBSD__)
1895 int len
= phnum
* sizeof(ElfW(Phdr
));
1897 ph
->p_type
= PT_PHDR
;
1898 ph
->p_offset
= sizeof(ElfW(Ehdr
));
1899 ph
->p_vaddr
= interp
->sh_addr
- len
;
1900 ph
->p_paddr
= ph
->p_vaddr
;
1901 ph
->p_filesz
= ph
->p_memsz
= len
;
1902 ph
->p_flags
= PF_R
| PF_X
;
1903 ph
->p_align
= 4; // interp->sh_addralign;
1908 ph
->p_type
= PT_INTERP
;
1909 ph
->p_offset
= interp
->sh_offset
;
1910 ph
->p_vaddr
= interp
->sh_addr
;
1911 ph
->p_paddr
= ph
->p_vaddr
;
1912 ph
->p_filesz
= interp
->sh_size
;
1913 ph
->p_memsz
= interp
->sh_size
;
1915 ph
->p_align
= interp
->sh_addralign
;
1918 /* if dynamic section, then add corresponing program header */
1922 ph
= &phdr
[phnum
- 1];
1924 ph
->p_type
= PT_DYNAMIC
;
1925 ph
->p_offset
= dynamic
->sh_offset
;
1926 ph
->p_vaddr
= dynamic
->sh_addr
;
1927 ph
->p_paddr
= ph
->p_vaddr
;
1928 ph
->p_filesz
= dynamic
->sh_size
;
1929 ph
->p_memsz
= dynamic
->sh_size
;
1930 ph
->p_flags
= PF_R
| PF_W
;
1931 ph
->p_align
= dynamic
->sh_addralign
;
1933 /* put GOT dynamic section address */
1934 put32(s1
->got
->data
, dynamic
->sh_addr
);
1936 /* relocate the PLT */
1937 if (file_type
== TCC_OUTPUT_EXE
1938 #if defined(TCC_OUTPUT_DLL_WITH_PLT)
1939 || file_type
== TCC_OUTPUT_DLL
1945 p_end
= p
+ s1
->plt
->data_offset
;
1947 #if defined(TCC_TARGET_I386)
1948 put32(p
+ 2, get32(p
+ 2) + s1
->got
->sh_addr
);
1949 put32(p
+ 8, get32(p
+ 8) + s1
->got
->sh_addr
);
1952 put32(p
+ 2, get32(p
+ 2) + s1
->got
->sh_addr
);
1955 #elif defined(TCC_TARGET_X86_64)
1956 int x
= s1
->got
->sh_addr
- s1
->plt
->sh_addr
- 6;
1957 put32(p
+ 2, get32(p
+ 2) + x
);
1958 put32(p
+ 8, get32(p
+ 8) + x
- 6);
1961 put32(p
+ 2, get32(p
+ 2) + x
+ s1
->plt
->data
- p
);
1964 #elif defined(TCC_TARGET_ARM)
1966 x
=s1
->got
->sh_addr
- s1
->plt
->sh_addr
- 12;
1969 put32(p
+ 12, x
+ get32(p
+ 12) + s1
->plt
->data
- p
);
1972 #elif defined(TCC_TARGET_C67)
1975 #error unsupported CPU
1980 /* relocate symbols in .dynsym */
1981 sym_end
= (ElfW(Sym
) *)(s1
->dynsym
->data
+ s1
->dynsym
->data_offset
);
1982 for(sym
= (ElfW(Sym
) *)s1
->dynsym
->data
+ 1;
1985 if (sym
->st_shndx
== SHN_UNDEF
) {
1986 /* relocate to the PLT if the symbol corresponds
1989 sym
->st_value
+= s1
->plt
->sh_addr
;
1990 } else if (sym
->st_shndx
< SHN_LORESERVE
) {
1991 /* do symbol relocation */
1992 sym
->st_value
+= s1
->sections
[sym
->st_shndx
]->sh_addr
;
1996 /* put dynamic section entries */
1997 dynamic
->data_offset
= saved_dynamic_data_offset
;
1998 put_dt(dynamic
, DT_HASH
, s1
->dynsym
->hash
->sh_addr
);
1999 put_dt(dynamic
, DT_STRTAB
, dynstr
->sh_addr
);
2000 put_dt(dynamic
, DT_SYMTAB
, s1
->dynsym
->sh_addr
);
2001 put_dt(dynamic
, DT_STRSZ
, dynstr
->data_offset
);
2002 put_dt(dynamic
, DT_SYMENT
, sizeof(ElfW(Sym
)));
2003 #ifdef TCC_TARGET_X86_64
2004 put_dt(dynamic
, DT_RELA
, rel_addr
);
2005 put_dt(dynamic
, DT_RELASZ
, rel_size
);
2006 put_dt(dynamic
, DT_RELAENT
, sizeof(ElfW_Rel
));
2008 #if defined(__FreeBSD__)
2009 put_dt(dynamic
, DT_PLTGOT
, s1
->got
->sh_addr
);
2010 put_dt(dynamic
, DT_PLTRELSZ
, rel_size
);
2011 put_dt(dynamic
, DT_JMPREL
, rel_addr
);
2012 put_dt(dynamic
, DT_PLTREL
, DT_REL
);
2013 put_dt(dynamic
, DT_REL
, bss_addr
);
2014 put_dt(dynamic
, DT_RELSZ
, bss_size
);
2016 put_dt(dynamic
, DT_REL
, rel_addr
);
2017 put_dt(dynamic
, DT_RELSZ
, rel_size
);
2018 put_dt(dynamic
, DT_RELENT
, sizeof(ElfW_Rel
));
2022 put_dt(dynamic
, DT_DEBUG
, 0);
2023 put_dt(dynamic
, DT_NULL
, 0);
2026 ehdr
.e_phentsize
= sizeof(ElfW(Phdr
));
2027 ehdr
.e_phnum
= phnum
;
2028 ehdr
.e_phoff
= sizeof(ElfW(Ehdr
));
2031 /* all other sections come after */
2032 for(i
= 1; i
< s1
->nb_sections
; i
++) {
2033 s
= s1
->sections
[i
];
2034 if (phnum
> 0 && (s
->sh_flags
& SHF_ALLOC
))
2036 section_order
[sh_order_index
++] = i
;
2038 file_offset
= (file_offset
+ s
->sh_addralign
- 1) &
2039 ~(s
->sh_addralign
- 1);
2040 s
->sh_offset
= file_offset
;
2041 if (s
->sh_type
!= SHT_NOBITS
)
2042 file_offset
+= s
->sh_size
;
2045 /* if building executable or DLL, then relocate each section
2046 except the GOT which is already relocated */
2047 if (file_type
!= TCC_OUTPUT_OBJ
) {
2048 relocate_syms(s1
, 0);
2050 if (s1
->nb_errors
!= 0) {
2056 /* relocate sections */
2057 /* XXX: ignore sections with allocated relocations ? */
2058 for(i
= 1; i
< s1
->nb_sections
; i
++) {
2059 s
= s1
->sections
[i
];
2060 if (s
->reloc
&& s
!= s1
->got
&& (s
->sh_flags
& SHF_ALLOC
)) //gr
2061 relocate_section(s1
, s
);
2064 /* relocate relocation entries if the relocation tables are
2065 allocated in the executable */
2066 for(i
= 1; i
< s1
->nb_sections
; i
++) {
2067 s
= s1
->sections
[i
];
2068 if ((s
->sh_flags
& SHF_ALLOC
) &&
2069 s
->sh_type
== SHT_RELX
) {
2070 relocate_rel(s1
, s
);
2074 /* get entry point address */
2075 if (file_type
== TCC_OUTPUT_EXE
)
2076 ehdr
.e_entry
= (uplong
)tcc_get_symbol_err(s1
, "_start");
2078 ehdr
.e_entry
= text_section
->sh_addr
; /* XXX: is it correct ? */
2080 if (file_type
== TCC_OUTPUT_EXE
&& s1
->static_link
)
2083 /* write elf file */
2084 if (file_type
== TCC_OUTPUT_OBJ
)
2088 fd
= open(filename
, O_WRONLY
| O_CREAT
| O_TRUNC
| O_BINARY
, mode
);
2090 error_noabort("could not write '%s'", filename
);
2093 f
= fdopen(fd
, "wb");
2095 printf("<- %s\n", filename
);
2097 #ifdef TCC_TARGET_COFF
2098 if (s1
->output_format
== TCC_OUTPUT_FORMAT_COFF
) {
2099 tcc_output_coff(s1
, f
);
2102 if (s1
->output_format
== TCC_OUTPUT_FORMAT_ELF
) {
2103 sort_syms(s1
, symtab_section
);
2106 file_offset
= (file_offset
+ 3) & -4;
2109 ehdr
.e_ident
[0] = ELFMAG0
;
2110 ehdr
.e_ident
[1] = ELFMAG1
;
2111 ehdr
.e_ident
[2] = ELFMAG2
;
2112 ehdr
.e_ident
[3] = ELFMAG3
;
2113 ehdr
.e_ident
[4] = TCC_ELFCLASS
;
2114 ehdr
.e_ident
[5] = ELFDATA2LSB
;
2115 ehdr
.e_ident
[6] = EV_CURRENT
;
2117 ehdr
.e_ident
[EI_OSABI
] = ELFOSABI_FREEBSD
;
2119 #ifdef TCC_TARGET_ARM
2121 ehdr
.e_ident
[EI_OSABI
] = 0;
2122 ehdr
.e_flags
= 4 << 24;
2124 ehdr
.e_ident
[EI_OSABI
] = ELFOSABI_ARM
;
2129 case TCC_OUTPUT_EXE
:
2130 ehdr
.e_type
= ET_EXEC
;
2132 case TCC_OUTPUT_DLL
:
2133 ehdr
.e_type
= ET_DYN
;
2135 case TCC_OUTPUT_OBJ
:
2136 ehdr
.e_type
= ET_REL
;
2139 ehdr
.e_machine
= EM_TCC_TARGET
;
2140 ehdr
.e_version
= EV_CURRENT
;
2141 ehdr
.e_shoff
= file_offset
;
2142 ehdr
.e_ehsize
= sizeof(ElfW(Ehdr
));
2143 ehdr
.e_shentsize
= sizeof(ElfW(Shdr
));
2144 ehdr
.e_shnum
= shnum
;
2145 ehdr
.e_shstrndx
= shnum
- 1;
2147 fwrite(&ehdr
, 1, sizeof(ElfW(Ehdr
)), f
);
2148 fwrite(phdr
, 1, phnum
* sizeof(ElfW(Phdr
)), f
);
2149 offset
= sizeof(ElfW(Ehdr
)) + phnum
* sizeof(ElfW(Phdr
));
2151 for(i
=1;i
<s1
->nb_sections
;i
++) {
2152 s
= s1
->sections
[section_order
[i
]];
2153 if (s
->sh_type
!= SHT_NOBITS
) {
2154 #if defined(__FreeBSD__)
2155 if (s
->sh_type
== SHT_DYNSYM
)
2156 patch_dynsym_undef(s1
, s
);
2158 while (offset
< s
->sh_offset
) {
2163 fwrite(s
->data
, 1, size
, f
);
2168 /* output section headers */
2169 while (offset
< ehdr
.e_shoff
) {
2174 for(i
=0;i
<s1
->nb_sections
;i
++) {
2176 memset(sh
, 0, sizeof(ElfW(Shdr
)));
2177 s
= s1
->sections
[i
];
2179 sh
->sh_name
= s
->sh_name
;
2180 sh
->sh_type
= s
->sh_type
;
2181 sh
->sh_flags
= s
->sh_flags
;
2182 sh
->sh_entsize
= s
->sh_entsize
;
2183 sh
->sh_info
= s
->sh_info
;
2185 sh
->sh_link
= s
->link
->sh_num
;
2186 sh
->sh_addralign
= s
->sh_addralign
;
2187 sh
->sh_addr
= s
->sh_addr
;
2188 sh
->sh_offset
= s
->sh_offset
;
2189 sh
->sh_size
= s
->sh_size
;
2191 fwrite(sh
, 1, sizeof(ElfW(Shdr
)), f
);
2194 tcc_output_binary(s1
, f
, section_order
);
2200 tcc_free(s1
->symtab_to_dynsym
);
2201 tcc_free(section_order
);
2203 tcc_free(s1
->got_offsets
);
2207 LIBTCCAPI
int tcc_output_file(TCCState
*s
, const char *filename
)
2210 #ifdef TCC_TARGET_PE
2211 if (s
->output_type
!= TCC_OUTPUT_OBJ
) {
2212 ret
= pe_output_file(s
, filename
);
2216 ret
= elf_output_file(s
, filename
);
2221 static void *load_data(int fd
, unsigned long file_offset
, unsigned long size
)
2225 data
= tcc_malloc(size
);
2226 lseek(fd
, file_offset
, SEEK_SET
);
2227 read(fd
, data
, size
);
2231 typedef struct SectionMergeInfo
{
2232 Section
*s
; /* corresponding existing section */
2233 unsigned long offset
; /* offset of the new section in the existing section */
2234 uint8_t new_section
; /* true if section 's' was added */
2235 uint8_t link_once
; /* true if link once section */
2238 /* load an object file and merge it with current files */
2239 /* XXX: handle correctly stab (debug) info */
2240 ST_FUNC
int tcc_load_object_file(TCCState
*s1
,
2241 int fd
, unsigned long file_offset
)
2244 ElfW(Shdr
) *shdr
, *sh
;
2245 int size
, i
, j
, offset
, offseti
, nb_syms
, sym_index
, ret
;
2246 unsigned char *strsec
, *strtab
;
2247 int *old_to_new_syms
;
2248 char *sh_name
, *name
;
2249 SectionMergeInfo
*sm_table
, *sm
;
2250 ElfW(Sym
) *sym
, *symtab
;
2251 ElfW_Rel
*rel
, *rel_end
;
2257 stab_index
= stabstr_index
= 0;
2259 if (read(fd
, &ehdr
, sizeof(ehdr
)) != sizeof(ehdr
))
2261 if (ehdr
.e_ident
[0] != ELFMAG0
||
2262 ehdr
.e_ident
[1] != ELFMAG1
||
2263 ehdr
.e_ident
[2] != ELFMAG2
||
2264 ehdr
.e_ident
[3] != ELFMAG3
)
2266 /* test if object file */
2267 if (ehdr
.e_type
!= ET_REL
)
2269 /* test CPU specific stuff */
2270 if (ehdr
.e_ident
[5] != ELFDATA2LSB
||
2271 ehdr
.e_machine
!= EM_TCC_TARGET
) {
2273 error_noabort("invalid object file");
2277 shdr
= load_data(fd
, file_offset
+ ehdr
.e_shoff
,
2278 sizeof(ElfW(Shdr
)) * ehdr
.e_shnum
);
2279 sm_table
= tcc_mallocz(sizeof(SectionMergeInfo
) * ehdr
.e_shnum
);
2281 /* load section names */
2282 sh
= &shdr
[ehdr
.e_shstrndx
];
2283 strsec
= load_data(fd
, file_offset
+ sh
->sh_offset
, sh
->sh_size
);
2285 /* load symtab and strtab */
2286 old_to_new_syms
= NULL
;
2290 for(i
= 1; i
< ehdr
.e_shnum
; i
++) {
2292 if (sh
->sh_type
== SHT_SYMTAB
) {
2294 error_noabort("object must contain only one symtab");
2299 nb_syms
= sh
->sh_size
/ sizeof(ElfW(Sym
));
2300 symtab
= load_data(fd
, file_offset
+ sh
->sh_offset
, sh
->sh_size
);
2301 sm_table
[i
].s
= symtab_section
;
2303 /* now load strtab */
2304 sh
= &shdr
[sh
->sh_link
];
2305 strtab
= load_data(fd
, file_offset
+ sh
->sh_offset
, sh
->sh_size
);
2309 /* now examine each section and try to merge its content with the
2311 for(i
= 1; i
< ehdr
.e_shnum
; i
++) {
2312 /* no need to examine section name strtab */
2313 if (i
== ehdr
.e_shstrndx
)
2316 sh_name
= strsec
+ sh
->sh_name
;
2317 /* ignore sections types we do not handle */
2318 if (sh
->sh_type
!= SHT_PROGBITS
&&
2319 sh
->sh_type
!= SHT_RELX
&&
2321 sh
->sh_type
!= SHT_ARM_EXIDX
&&
2323 sh
->sh_type
!= SHT_NOBITS
&&
2324 sh
->sh_type
!= SHT_PREINIT_ARRAY
&&
2325 sh
->sh_type
!= SHT_INIT_ARRAY
&&
2326 sh
->sh_type
!= SHT_FINI_ARRAY
&&
2327 strcmp(sh_name
, ".stabstr")
2330 if (sh
->sh_addralign
< 1)
2331 sh
->sh_addralign
= 1;
2332 /* find corresponding section, if any */
2333 for(j
= 1; j
< s1
->nb_sections
;j
++) {
2334 s
= s1
->sections
[j
];
2335 if (!strcmp(s
->name
, sh_name
)) {
2336 if (!strncmp(sh_name
, ".gnu.linkonce",
2337 sizeof(".gnu.linkonce") - 1)) {
2338 /* if a 'linkonce' section is already present, we
2339 do not add it again. It is a little tricky as
2340 symbols can still be defined in
2342 sm_table
[i
].link_once
= 1;
2349 /* not found: create new section */
2350 s
= new_section(s1
, sh_name
, sh
->sh_type
, sh
->sh_flags
);
2351 /* take as much info as possible from the section. sh_link and
2352 sh_info will be updated later */
2353 s
->sh_addralign
= sh
->sh_addralign
;
2354 s
->sh_entsize
= sh
->sh_entsize
;
2355 sm_table
[i
].new_section
= 1;
2357 if (sh
->sh_type
!= s
->sh_type
) {
2358 error_noabort("invalid section type");
2362 /* align start of section */
2363 offset
= s
->data_offset
;
2365 if (0 == strcmp(sh_name
, ".stab")) {
2369 if (0 == strcmp(sh_name
, ".stabstr")) {
2374 size
= sh
->sh_addralign
- 1;
2375 offset
= (offset
+ size
) & ~size
;
2376 if (sh
->sh_addralign
> s
->sh_addralign
)
2377 s
->sh_addralign
= sh
->sh_addralign
;
2378 s
->data_offset
= offset
;
2380 sm_table
[i
].offset
= offset
;
2382 /* concatenate sections */
2384 if (sh
->sh_type
!= SHT_NOBITS
) {
2386 lseek(fd
, file_offset
+ sh
->sh_offset
, SEEK_SET
);
2387 ptr
= section_ptr_add(s
, size
);
2388 read(fd
, ptr
, size
);
2390 s
->data_offset
+= size
;
2395 /* //gr relocate stab strings */
2396 if (stab_index
&& stabstr_index
) {
2399 s
= sm_table
[stab_index
].s
;
2400 a
= (Stab_Sym
*)(s
->data
+ sm_table
[stab_index
].offset
);
2401 b
= (Stab_Sym
*)(s
->data
+ s
->data_offset
);
2402 o
= sm_table
[stabstr_index
].offset
;
2404 a
->n_strx
+= o
, a
++;
2407 /* second short pass to update sh_link and sh_info fields of new
2409 for(i
= 1; i
< ehdr
.e_shnum
; i
++) {
2411 if (!s
|| !sm_table
[i
].new_section
)
2414 if (sh
->sh_link
> 0)
2415 s
->link
= sm_table
[sh
->sh_link
].s
;
2416 if (sh
->sh_type
== SHT_RELX
) {
2417 s
->sh_info
= sm_table
[sh
->sh_info
].s
->sh_num
;
2418 /* update backward link */
2419 s1
->sections
[s
->sh_info
]->reloc
= s
;
2424 /* resolve symbols */
2425 old_to_new_syms
= tcc_mallocz(nb_syms
* sizeof(int));
2428 for(i
= 1; i
< nb_syms
; i
++, sym
++) {
2429 if (sym
->st_shndx
!= SHN_UNDEF
&&
2430 sym
->st_shndx
< SHN_LORESERVE
) {
2431 sm
= &sm_table
[sym
->st_shndx
];
2432 if (sm
->link_once
) {
2433 /* if a symbol is in a link once section, we use the
2434 already defined symbol. It is very important to get
2435 correct relocations */
2436 if (ELFW(ST_BIND
)(sym
->st_info
) != STB_LOCAL
) {
2437 name
= strtab
+ sym
->st_name
;
2438 sym_index
= find_elf_sym(symtab_section
, name
);
2440 old_to_new_syms
[i
] = sym_index
;
2444 /* if no corresponding section added, no need to add symbol */
2447 /* convert section number */
2448 sym
->st_shndx
= sm
->s
->sh_num
;
2450 sym
->st_value
+= sm
->offset
;
2453 name
= strtab
+ sym
->st_name
;
2454 sym_index
= add_elf_sym(symtab_section
, sym
->st_value
, sym
->st_size
,
2455 sym
->st_info
, sym
->st_other
,
2456 sym
->st_shndx
, name
);
2457 old_to_new_syms
[i
] = sym_index
;
2460 /* third pass to patch relocation entries */
2461 for(i
= 1; i
< ehdr
.e_shnum
; i
++) {
2466 offset
= sm_table
[i
].offset
;
2467 switch(s
->sh_type
) {
2469 /* take relocation offset information */
2470 offseti
= sm_table
[sh
->sh_info
].offset
;
2471 rel_end
= (ElfW_Rel
*)(s
->data
+ s
->data_offset
);
2472 for(rel
= (ElfW_Rel
*)(s
->data
+ offset
);
2477 /* convert symbol index */
2478 type
= ELFW(R_TYPE
)(rel
->r_info
);
2479 sym_index
= ELFW(R_SYM
)(rel
->r_info
);
2480 /* NOTE: only one symtab assumed */
2481 if (sym_index
>= nb_syms
)
2483 sym_index
= old_to_new_syms
[sym_index
];
2484 /* ignore link_once in rel section. */
2485 if (!sym_index
&& !sm
->link_once
2486 #ifdef TCC_TARGET_ARM
2487 && type
!= R_ARM_V4BX
2491 error_noabort("Invalid relocation entry [%2d] '%s' @ %.8x",
2492 i
, strsec
+ sh
->sh_name
, rel
->r_offset
);
2495 rel
->r_info
= ELFW(R_INFO
)(sym_index
, type
);
2496 /* offset the relocation offset */
2497 rel
->r_offset
+= offseti
;
2509 tcc_free(old_to_new_syms
);
2516 typedef struct ArchiveHeader
{
2517 char ar_name
[16]; /* name of this member */
2518 char ar_date
[12]; /* file mtime */
2519 char ar_uid
[6]; /* owner uid; printed as decimal */
2520 char ar_gid
[6]; /* owner gid; printed as decimal */
2521 char ar_mode
[8]; /* file mode, printed as octal */
2522 char ar_size
[10]; /* file size, printed as decimal */
2523 char ar_fmag
[2]; /* should contain ARFMAG */
2526 static int get_be32(const uint8_t *b
)
2528 return b
[3] | (b
[2] << 8) | (b
[1] << 16) | (b
[0] << 24);
2531 /* load only the objects which resolve undefined symbols */
2532 static int tcc_load_alacarte(TCCState
*s1
, int fd
, int size
)
2534 int i
, bound
, nsyms
, sym_index
, off
, ret
;
2536 const char *ar_names
, *p
;
2537 const uint8_t *ar_index
;
2540 data
= tcc_malloc(size
);
2541 if (read(fd
, data
, size
) != size
)
2543 nsyms
= get_be32(data
);
2544 ar_index
= data
+ 4;
2545 ar_names
= ar_index
+ nsyms
* 4;
2549 for(p
= ar_names
, i
= 0; i
< nsyms
; i
++, p
+= strlen(p
)+1) {
2550 sym_index
= find_elf_sym(symtab_section
, p
);
2552 sym
= &((ElfW(Sym
) *)symtab_section
->data
)[sym_index
];
2553 if(sym
->st_shndx
== SHN_UNDEF
) {
2554 off
= get_be32(ar_index
+ i
* 4) + sizeof(ArchiveHeader
);
2556 printf("%5d\t%s\t%08x\n", i
, p
, sym
->st_shndx
);
2559 lseek(fd
, off
, SEEK_SET
);
2560 if(tcc_load_object_file(s1
, fd
, off
) < 0) {
2575 /* load a '.a' file */
2576 ST_FUNC
int tcc_load_archive(TCCState
*s1
, int fd
)
2583 unsigned long file_offset
;
2585 /* skip magic which was already checked */
2586 read(fd
, magic
, sizeof(magic
));
2589 len
= read(fd
, &hdr
, sizeof(hdr
));
2592 if (len
!= sizeof(hdr
)) {
2593 error_noabort("invalid archive");
2596 memcpy(ar_size
, hdr
.ar_size
, sizeof(hdr
.ar_size
));
2597 ar_size
[sizeof(hdr
.ar_size
)] = '\0';
2598 size
= strtol(ar_size
, NULL
, 0);
2599 memcpy(ar_name
, hdr
.ar_name
, sizeof(hdr
.ar_name
));
2600 for(i
= sizeof(hdr
.ar_name
) - 1; i
>= 0; i
--) {
2601 if (ar_name
[i
] != ' ')
2604 ar_name
[i
+ 1] = '\0';
2605 // printf("name='%s' size=%d %s\n", ar_name, size, ar_size);
2606 file_offset
= lseek(fd
, 0, SEEK_CUR
);
2608 size
= (size
+ 1) & ~1;
2609 if (!strcmp(ar_name
, "/")) {
2610 /* coff symbol table : we handle it */
2611 if(s1
->alacarte_link
)
2612 return tcc_load_alacarte(s1
, fd
, size
);
2613 } else if (!strcmp(ar_name
, "//") ||
2614 !strcmp(ar_name
, "__.SYMDEF") ||
2615 !strcmp(ar_name
, "__.SYMDEF/") ||
2616 !strcmp(ar_name
, "ARFILENAMES/")) {
2617 /* skip symbol table or archive names */
2619 if (tcc_load_object_file(s1
, fd
, file_offset
) < 0)
2622 lseek(fd
, file_offset
+ size
, SEEK_SET
);
2627 #ifndef TCC_TARGET_PE
2628 /* load a DLL and all referenced DLLs. 'level = 0' means that the DLL
2629 is referenced by the user (so it should be added as DT_NEEDED in
2630 the generated ELF file) */
2631 ST_FUNC
int tcc_load_dll(TCCState
*s1
, int fd
, const char *filename
, int level
)
2634 ElfW(Shdr
) *shdr
, *sh
, *sh1
;
2635 int i
, j
, nb_syms
, nb_dts
, sym_bind
, ret
;
2636 ElfW(Sym
) *sym
, *dynsym
;
2637 ElfW(Dyn
) *dt
, *dynamic
;
2638 unsigned char *dynstr
;
2639 const char *name
, *soname
;
2640 DLLReference
*dllref
;
2642 read(fd
, &ehdr
, sizeof(ehdr
));
2644 /* test CPU specific stuff */
2645 if (ehdr
.e_ident
[5] != ELFDATA2LSB
||
2646 ehdr
.e_machine
!= EM_TCC_TARGET
) {
2647 error_noabort("bad architecture");
2652 shdr
= load_data(fd
, ehdr
.e_shoff
, sizeof(ElfW(Shdr
)) * ehdr
.e_shnum
);
2654 /* load dynamic section and dynamic symbols */
2658 dynsym
= NULL
; /* avoid warning */
2659 dynstr
= NULL
; /* avoid warning */
2660 for(i
= 0, sh
= shdr
; i
< ehdr
.e_shnum
; i
++, sh
++) {
2661 switch(sh
->sh_type
) {
2663 nb_dts
= sh
->sh_size
/ sizeof(ElfW(Dyn
));
2664 dynamic
= load_data(fd
, sh
->sh_offset
, sh
->sh_size
);
2667 nb_syms
= sh
->sh_size
/ sizeof(ElfW(Sym
));
2668 dynsym
= load_data(fd
, sh
->sh_offset
, sh
->sh_size
);
2669 sh1
= &shdr
[sh
->sh_link
];
2670 dynstr
= load_data(fd
, sh1
->sh_offset
, sh1
->sh_size
);
2677 /* compute the real library name */
2678 soname
= tcc_basename(filename
);
2680 for(i
= 0, dt
= dynamic
; i
< nb_dts
; i
++, dt
++) {
2681 if (dt
->d_tag
== DT_SONAME
) {
2682 soname
= dynstr
+ dt
->d_un
.d_val
;
2686 /* if the dll is already loaded, do not load it */
2687 for(i
= 0; i
< s1
->nb_loaded_dlls
; i
++) {
2688 dllref
= s1
->loaded_dlls
[i
];
2689 if (!strcmp(soname
, dllref
->name
)) {
2690 /* but update level if needed */
2691 if (level
< dllref
->level
)
2692 dllref
->level
= level
;
2698 // printf("loading dll '%s'\n", soname);
2700 /* add the dll and its level */
2701 dllref
= tcc_mallocz(sizeof(DLLReference
) + strlen(soname
));
2702 dllref
->level
= level
;
2703 strcpy(dllref
->name
, soname
);
2704 dynarray_add((void ***)&s1
->loaded_dlls
, &s1
->nb_loaded_dlls
, dllref
);
2706 /* add dynamic symbols in dynsym_section */
2707 for(i
= 1, sym
= dynsym
+ 1; i
< nb_syms
; i
++, sym
++) {
2708 sym_bind
= ELFW(ST_BIND
)(sym
->st_info
);
2709 if (sym_bind
== STB_LOCAL
)
2711 name
= dynstr
+ sym
->st_name
;
2712 add_elf_sym(s1
->dynsymtab_section
, sym
->st_value
, sym
->st_size
,
2713 sym
->st_info
, sym
->st_other
, sym
->st_shndx
, name
);
2716 /* load all referenced DLLs */
2717 for(i
= 0, dt
= dynamic
; i
< nb_dts
; i
++, dt
++) {
2720 name
= dynstr
+ dt
->d_un
.d_val
;
2721 for(j
= 0; j
< s1
->nb_loaded_dlls
; j
++) {
2722 dllref
= s1
->loaded_dlls
[j
];
2723 if (!strcmp(name
, dllref
->name
))
2724 goto already_loaded
;
2726 if (tcc_add_dll(s1
, name
, AFF_REFERENCED_DLL
) < 0) {
2727 error_noabort("referenced dll '%s' not found", name
);
2744 #define LD_TOK_NAME 256
2745 #define LD_TOK_EOF (-1)
2747 /* return next ld script token */
2748 static int ld_next(TCCState
*s1
, char *name
, int name_size
)
2766 file
->buf_ptr
= parse_comment(file
->buf_ptr
);
2767 ch
= file
->buf_ptr
[0];
2775 /* case 'a' ... 'z': */
2802 /* case 'A' ... 'z': */
2837 if (!((ch
>= 'a' && ch
<= 'z') ||
2838 (ch
>= 'A' && ch
<= 'Z') ||
2839 (ch
>= '0' && ch
<= '9') ||
2840 strchr("/.-_+=$:\\,~", ch
)))
2842 if ((q
- name
) < name_size
- 1) {
2859 printf("tok=%c %d\n", c
, c
);
2860 if (c
== LD_TOK_NAME
)
2861 printf(" name=%s\n", name
);
2866 char *tcc_strcpy_part(char *out
, const char *in
, size_t num
)
2868 memcpy(out
, in
, num
);
2874 * Extract the library name from the file name
2875 * Return 0 if the file isn't a library
2877 * /!\ No test on filename capacity, be careful
2879 static int filename_to_libname(TCCState
*s1
, const char filename
[], char libname
[])
2884 /* already converted to library name */
2885 if (libname
[0] != '\0')
2887 ext
= tcc_fileextension(filename
);
2890 libprefix
= !strncmp(filename
, "lib", 3);
2891 if (!s1
->static_link
) {
2892 #ifdef TCC_TARGET_PE
2893 if (!strcmp(ext
, ".def")) {
2894 size_t len
= ext
- filename
;
2895 tcc_strcpy_part(libname
, filename
, len
);
2899 if (libprefix
&& (!strcmp(ext
, ".so"))) {
2900 size_t len
= ext
- filename
- 3;
2901 tcc_strcpy_part(libname
, filename
+ 3, len
);
2906 if (libprefix
&& (!strcmp(ext
, ".a"))) {
2907 size_t len
= ext
- filename
- 3;
2908 tcc_strcpy_part(libname
, filename
+ 3, len
);
2916 * Extract the file name from the library name
2918 * /!\ No test on filename capacity, be careful
2920 static void libname_to_filename(TCCState
*s1
, const char libname
[], char filename
[])
2922 if (!s1
->static_link
) {
2923 #ifdef TCC_TARGET_PE
2924 sprintf(filename
, "%s.def", libname
);
2926 sprintf(filename
, "lib%s.so", libname
);
2929 sprintf(filename
, "lib%s.a", libname
);
2933 static int ld_add_file(TCCState
*s1
, const char filename
[], char libname
[])
2937 ret
= tcc_add_file_internal(s1
, filename
, 0);
2939 if (filename_to_libname(s1
, filename
, libname
))
2940 ret
= tcc_add_library(s1
, libname
);
2945 static inline int new_undef_syms(void)
2948 ret
= new_undef_sym
;
2953 static int ld_add_file_list(TCCState
*s1
, const char *cmd
, int as_needed
)
2955 char filename
[1024], libname
[1024];
2956 int t
, group
, nblibs
= 0, ret
= 0;
2959 group
= !strcmp(cmd
, "GROUP");
2962 t
= ld_next(s1
, filename
, sizeof(filename
));
2965 t
= ld_next(s1
, filename
, sizeof(filename
));
2968 if (t
== LD_TOK_EOF
) {
2969 error_noabort("unexpected end of file");
2971 goto lib_parse_error
;
2972 } else if (t
== ')') {
2974 } else if (t
== '-') {
2975 t
= ld_next(s1
, filename
, sizeof(filename
));
2976 if ((t
!= LD_TOK_NAME
) || (filename
[0] != 'l')) {
2977 error_noabort("library name expected");
2979 goto lib_parse_error
;
2981 strcpy(libname
, &filename
[1]);
2982 libname_to_filename(s1
, libname
, filename
);
2983 } else if (t
!= LD_TOK_NAME
) {
2984 error_noabort("filename expected");
2986 goto lib_parse_error
;
2988 if (!strcmp(filename
, "AS_NEEDED")) {
2989 ret
= ld_add_file_list(s1
, cmd
, 1);
2991 goto lib_parse_error
;
2993 /* TODO: Implement AS_NEEDED support. Ignore it for now */
2995 ret
= ld_add_file(s1
, filename
, libname
);
2997 goto lib_parse_error
;
2999 /* Add the filename *and* the libname to avoid future conversions */
3000 dynarray_add((void ***) &libs
, &nblibs
, tcc_strdup(filename
));
3001 dynarray_add((void ***) &libs
, &nblibs
, tcc_strdup(libname
));
3005 t
= ld_next(s1
, filename
, sizeof(filename
));
3007 t
= ld_next(s1
, filename
, sizeof(filename
));
3010 if (group
&& !as_needed
) {
3011 while (new_undef_syms()) {
3014 for (i
= 0; i
< nblibs
; i
+= 2)
3015 ld_add_file(s1
, libs
[i
], libs
[i
+1]);
3019 dynarray_reset(&libs
, &nblibs
);
3023 /* interpret a subset of GNU ldscripts to handle the dummy libc.so
3025 ST_FUNC
int tcc_load_ldscript(TCCState
*s1
)
3028 char filename
[1024];
3031 ch
= file
->buf_ptr
[0];
3034 t
= ld_next(s1
, cmd
, sizeof(cmd
));
3035 if (t
== LD_TOK_EOF
)
3037 else if (t
!= LD_TOK_NAME
)
3039 if (!strcmp(cmd
, "INPUT") ||
3040 !strcmp(cmd
, "GROUP")) {
3041 ret
= ld_add_file_list(s1
, cmd
, 0);
3044 } else if (!strcmp(cmd
, "OUTPUT_FORMAT") ||
3045 !strcmp(cmd
, "TARGET")) {
3046 /* ignore some commands */
3047 t
= ld_next(s1
, cmd
, sizeof(cmd
));
3051 t
= ld_next(s1
, filename
, sizeof(filename
));
3052 if (t
== LD_TOK_EOF
) {
3053 error_noabort("unexpected end of file");
3055 } else if (t
== ')') {