diff options
Diffstat (limited to 'tinycc/tccelf.c')
| -rw-r--r-- | tinycc/tccelf.c | 3936 |
1 files changed, 3936 insertions, 0 deletions
diff --git a/tinycc/tccelf.c b/tinycc/tccelf.c new file mode 100644 index 0000000..b46ad4c --- /dev/null +++ b/tinycc/tccelf.c @@ -0,0 +1,3936 @@ +/* + * ELF file handling for TCC + * + * Copyright (c) 2001-2004 Fabrice Bellard + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include "tcc.h" + +/* Define this to get some debug output during relocation processing. */ +#undef DEBUG_RELOC + +/********************************************************/ +/* global variables */ + +/* elf version information */ +struct sym_version { + char *lib; + char *version; + int out_index; + int prev_same_lib; +}; + +#define nb_sym_versions s1->nb_sym_versions +#define sym_versions s1->sym_versions +#define nb_sym_to_version s1->nb_sym_to_version +#define sym_to_version s1->sym_to_version +#define dt_verneednum s1->dt_verneednum +#define versym_section s1->versym_section +#define verneed_section s1->verneed_section + +/* special flag to indicate that the section should not be linked to the other ones */ +#define SHF_PRIVATE 0x80000000 +/* section is dynsymtab_section */ +#define SHF_DYNSYM 0x40000000 + +#ifdef TCC_TARGET_PE +static const int shf_RELRO = SHF_ALLOC; +static const char rdata[] = ".rdata"; +#else +static const int shf_RELRO = SHF_ALLOC | SHF_WRITE; +static const char rdata[] = ".data.ro"; +#endif + +/* ------------------------------------------------------------------------- */ + +ST_FUNC void tccelf_new(TCCState *s) +{ + TCCState *s1 = s; + /* no section zero */ + dynarray_add(&s->sections, &s->nb_sections, NULL); + + /* create standard sections */ + text_section = new_section(s, ".text", SHT_PROGBITS, SHF_ALLOC | SHF_EXECINSTR); + data_section = new_section(s, ".data", SHT_PROGBITS, SHF_ALLOC | SHF_WRITE); + /* create ro data section (make ro after relocation done with GNU_RELRO) */ + rodata_section = new_section(s, rdata, SHT_PROGBITS, shf_RELRO); + bss_section = new_section(s, ".bss", SHT_NOBITS, SHF_ALLOC | SHF_WRITE); + common_section = new_section(s, ".common", SHT_NOBITS, SHF_PRIVATE); + common_section->sh_num = SHN_COMMON; + + /* symbols are always generated for linking stage */ + symtab_section = new_symtab(s, ".symtab", SHT_SYMTAB, 0, + ".strtab", + ".hashtab", SHF_PRIVATE); + s->symtab = symtab_section; + + /* private symbol table for dynamic symbols */ + s->dynsymtab_section = new_symtab(s, ".dynsymtab", SHT_SYMTAB, SHF_PRIVATE|SHF_DYNSYM, + ".dynstrtab", + ".dynhashtab", SHF_PRIVATE); + get_sym_attr(s, 0, 1); +} + +#ifdef CONFIG_TCC_BCHECK +ST_FUNC void tccelf_bounds_new(TCCState *s) +{ + TCCState *s1 = s; + /* create bounds sections (make ro after relocation done with GNU_RELRO) */ + bounds_section = new_section(s, ".bounds", SHT_PROGBITS, shf_RELRO); + lbounds_section = new_section(s, ".lbounds", SHT_PROGBITS, shf_RELRO); +} +#endif + +static void free_section(Section *s) +{ + tcc_free(s->data); +} + +ST_FUNC void tccelf_delete(TCCState *s1) +{ + int i; + +#ifndef ELF_OBJ_ONLY + /* free symbol versions */ + for (i = 0; i < nb_sym_versions; i++) { + tcc_free(sym_versions[i].version); + tcc_free(sym_versions[i].lib); + } + tcc_free(sym_versions); + tcc_free(sym_to_version); +#endif + + /* free all sections */ + for(i = 1; i < s1->nb_sections; i++) + free_section(s1->sections[i]); + dynarray_reset(&s1->sections, &s1->nb_sections); + + for(i = 0; i < s1->nb_priv_sections; i++) + free_section(s1->priv_sections[i]); + dynarray_reset(&s1->priv_sections, &s1->nb_priv_sections); + + /* free any loaded DLLs */ +#ifdef TCC_IS_NATIVE + for ( i = 0; i < s1->nb_loaded_dlls; i++) { + DLLReference *ref = s1->loaded_dlls[i]; + if ( ref->handle ) +# ifdef _WIN32 + FreeLibrary((HMODULE)ref->handle); +# else + dlclose(ref->handle); +# endif + } +#endif + /* free loaded dlls array */ + dynarray_reset(&s1->loaded_dlls, &s1->nb_loaded_dlls); + tcc_free(s1->sym_attrs); + + symtab_section = NULL; /* for tccrun.c:rt_printline() */ +} + +/* save section data state */ +ST_FUNC void tccelf_begin_file(TCCState *s1) +{ + Section *s; int i; + for (i = 1; i < s1->nb_sections; i++) { + s = s1->sections[i]; + s->sh_offset = s->data_offset; + } + /* disable symbol hashing during compilation */ + s = s1->symtab, s->reloc = s->hash, s->hash = NULL; +#if defined TCC_TARGET_X86_64 && defined TCC_TARGET_PE + s1->uw_sym = 0; +#endif +} + +/* At the end of compilation, convert any UNDEF syms to global, and merge + with previously existing symbols */ +ST_FUNC void tccelf_end_file(TCCState *s1) +{ + Section *s = s1->symtab; + int first_sym, nb_syms, *tr, i; + + first_sym = s->sh_offset / sizeof (ElfSym); + nb_syms = s->data_offset / sizeof (ElfSym) - first_sym; + s->data_offset = s->sh_offset; + s->link->data_offset = s->link->sh_offset; + s->hash = s->reloc, s->reloc = NULL; + tr = tcc_mallocz(nb_syms * sizeof *tr); + + for (i = 0; i < nb_syms; ++i) { + ElfSym *sym = (ElfSym*)s->data + first_sym + i; + if (sym->st_shndx == SHN_UNDEF + && ELFW(ST_BIND)(sym->st_info) == STB_LOCAL) + sym->st_info = ELFW(ST_INFO)(STB_GLOBAL, ELFW(ST_TYPE)(sym->st_info)); + tr[i] = set_elf_sym(s, sym->st_value, sym->st_size, sym->st_info, + sym->st_other, sym->st_shndx, (char*)s->link->data + sym->st_name); + } + /* now update relocations */ + for (i = 1; i < s1->nb_sections; i++) { + Section *sr = s1->sections[i]; + if (sr->sh_type == SHT_RELX && sr->link == s) { + ElfW_Rel *rel = (ElfW_Rel*)(sr->data + sr->sh_offset); + ElfW_Rel *rel_end = (ElfW_Rel*)(sr->data + sr->data_offset); + for (; rel < rel_end; ++rel) { + int n = ELFW(R_SYM)(rel->r_info) - first_sym; + if (n < 0) /* zero sym_index in reloc (can happen with asm) */ + continue; + rel->r_info = ELFW(R_INFO)(tr[n], ELFW(R_TYPE)(rel->r_info)); + } + } + } + tcc_free(tr); + + /* record text/data/bss output for -bench info */ + for (i = 0; i < 4; ++i) { + s = s1->sections[i + 1]; + s1->total_output[i] += s->data_offset - s->sh_offset; + } +} + +ST_FUNC Section *new_section(TCCState *s1, const char *name, int sh_type, int sh_flags) +{ + Section *sec; + + sec = tcc_mallocz(sizeof(Section) + strlen(name)); + sec->s1 = s1; + strcpy(sec->name, name); + sec->sh_type = sh_type; + sec->sh_flags = sh_flags; + switch(sh_type) { + case SHT_GNU_versym: + sec->sh_addralign = 2; + break; + case SHT_HASH: + case SHT_GNU_HASH: + case SHT_REL: + case SHT_RELA: + case SHT_DYNSYM: + case SHT_SYMTAB: + case SHT_DYNAMIC: + case SHT_GNU_verneed: + case SHT_GNU_verdef: + sec->sh_addralign = PTR_SIZE; + break; + case SHT_STRTAB: + sec->sh_addralign = 1; + break; + default: + sec->sh_addralign = PTR_SIZE; /* gcc/pcc default alignment */ + break; + } + + if (sh_flags & SHF_PRIVATE) { + dynarray_add(&s1->priv_sections, &s1->nb_priv_sections, sec); + } else { + sec->sh_num = s1->nb_sections; + dynarray_add(&s1->sections, &s1->nb_sections, sec); + } + + return sec; +} + +ST_FUNC Section *new_symtab(TCCState *s1, + const char *symtab_name, int sh_type, int sh_flags, + const char *strtab_name, + const char *hash_name, int hash_sh_flags) +{ + Section *symtab, *strtab, *hash; + int *ptr, nb_buckets; + + symtab = new_section(s1, symtab_name, sh_type, sh_flags); + symtab->sh_entsize = sizeof(ElfW(Sym)); + strtab = new_section(s1, strtab_name, SHT_STRTAB, sh_flags); + put_elf_str(strtab, ""); + symtab->link = strtab; + put_elf_sym(symtab, 0, 0, 0, 0, 0, NULL); + + nb_buckets = 1; + + hash = new_section(s1, hash_name, SHT_HASH, hash_sh_flags); + hash->sh_entsize = sizeof(int); + symtab->hash = hash; + hash->link = symtab; + + ptr = section_ptr_add(hash, (2 + nb_buckets + 1) * sizeof(int)); + ptr[0] = nb_buckets; + ptr[1] = 1; + memset(ptr + 2, 0, (nb_buckets + 1) * sizeof(int)); + return symtab; +} + +/* realloc section and set its content to zero */ +ST_FUNC void section_realloc(Section *sec, unsigned long new_size) +{ + unsigned long size; + unsigned char *data; + + size = sec->data_allocated; + if (size == 0) + size = 1; + while (size < new_size) + size = size * 2; + data = tcc_realloc(sec->data, size); + memset(data + sec->data_allocated, 0, size - sec->data_allocated); + sec->data = data; + sec->data_allocated = size; +} + +/* reserve at least 'size' bytes aligned per 'align' in section + 'sec' from current offset, and return the aligned offset */ +ST_FUNC size_t section_add(Section *sec, addr_t size, int align) +{ + size_t offset, offset1; + + offset = (sec->data_offset + align - 1) & -align; + offset1 = offset + size; + if (sec->sh_type != SHT_NOBITS && offset1 > sec->data_allocated) + section_realloc(sec, offset1); + sec->data_offset = offset1; + if (align > sec->sh_addralign) + sec->sh_addralign = align; + return offset; +} + +/* reserve at least 'size' bytes in section 'sec' from + sec->data_offset. */ +ST_FUNC void *section_ptr_add(Section *sec, addr_t size) +{ + size_t offset = section_add(sec, size, 1); + return sec->data + offset; +} + +#ifndef ELF_OBJ_ONLY +/* reserve at least 'size' bytes from section start */ +static void section_reserve(Section *sec, unsigned long size) +{ + if (size > sec->data_allocated) + section_realloc(sec, size); + if (size > sec->data_offset) + sec->data_offset = size; +} +#endif + +static Section *have_section(TCCState *s1, const char *name) +{ + Section *sec; + int i; + for(i = 1; i < s1->nb_sections; i++) { + sec = s1->sections[i]; + if (!strcmp(name, sec->name)) + return sec; + } + return NULL; +} + +/* return a reference to a section, and create it if it does not + exists */ +ST_FUNC Section *find_section(TCCState *s1, const char *name) +{ + Section *sec = have_section(s1, name); + if (sec) + return sec; + /* sections are created as PROGBITS */ + return new_section(s1, name, SHT_PROGBITS, SHF_ALLOC); +} + +/* ------------------------------------------------------------------------- */ + +ST_FUNC int put_elf_str(Section *s, const char *sym) +{ + int offset, len; + char *ptr; + + len = strlen(sym) + 1; + offset = s->data_offset; + ptr = section_ptr_add(s, len); + memmove(ptr, sym, len); + return offset; +} + +/* elf symbol hashing function */ +static ElfW(Word) elf_hash(const unsigned char *name) +{ + ElfW(Word) h = 0, g; + + while (*name) { + h = (h << 4) + *name++; + g = h & 0xf0000000; + if (g) + h ^= g >> 24; + h &= ~g; + } + return h; +} + +/* rebuild hash table of section s */ +/* NOTE: we do factorize the hash table code to go faster */ +static void rebuild_hash(Section *s, unsigned int nb_buckets) +{ + ElfW(Sym) *sym; + int *ptr, *hash, nb_syms, sym_index, h; + unsigned char *strtab; + + strtab = s->link->data; + nb_syms = s->data_offset / sizeof(ElfW(Sym)); + + if (!nb_buckets) + nb_buckets = ((int*)s->hash->data)[0]; + + s->hash->data_offset = 0; + ptr = section_ptr_add(s->hash, (2 + nb_buckets + nb_syms) * sizeof(int)); + ptr[0] = nb_buckets; + ptr[1] = nb_syms; + ptr += 2; + hash = ptr; + memset(hash, 0, (nb_buckets + 1) * sizeof(int)); + ptr += nb_buckets + 1; + + sym = (ElfW(Sym) *)s->data + 1; + for(sym_index = 1; sym_index < nb_syms; sym_index++) { + if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) { + h = elf_hash(strtab + sym->st_name) % nb_buckets; + *ptr = hash[h]; + hash[h] = sym_index; + } else { + *ptr = 0; + } + ptr++; + sym++; + } +} + +/* return the symbol number */ +ST_FUNC int put_elf_sym(Section *s, addr_t value, unsigned long size, + int info, int other, int shndx, const char *name) +{ + int name_offset, sym_index; + int nbuckets, h; + ElfW(Sym) *sym; + Section *hs; + + sym = section_ptr_add(s, sizeof(ElfW(Sym))); + if (name && name[0]) + name_offset = put_elf_str(s->link, name); + else + name_offset = 0; + /* XXX: endianness */ + sym->st_name = name_offset; + sym->st_value = value; + sym->st_size = size; + sym->st_info = info; + sym->st_other = other; + sym->st_shndx = shndx; + sym_index = sym - (ElfW(Sym) *)s->data; + hs = s->hash; + if (hs) { + int *ptr, *base; + ptr = section_ptr_add(hs, sizeof(int)); + base = (int *)hs->data; + /* only add global or weak symbols. */ + if (ELFW(ST_BIND)(info) != STB_LOCAL) { + /* add another hashing entry */ + nbuckets = base[0]; + h = elf_hash((unsigned char *)s->link->data + name_offset) % nbuckets; + *ptr = base[2 + h]; + base[2 + h] = sym_index; + base[1]++; + /* we resize the hash table */ + hs->nb_hashed_syms++; + if (hs->nb_hashed_syms > 2 * nbuckets) { + rebuild_hash(s, 2 * nbuckets); + } + } else { + *ptr = 0; + base[1]++; + } + } + return sym_index; +} + +ST_FUNC int find_elf_sym(Section *s, const char *name) +{ + ElfW(Sym) *sym; + Section *hs; + int nbuckets, sym_index, h; + const char *name1; + + hs = s->hash; + if (!hs) + return 0; + nbuckets = ((int *)hs->data)[0]; + h = elf_hash((unsigned char *) name) % nbuckets; + sym_index = ((int *)hs->data)[2 + h]; + while (sym_index != 0) { + sym = &((ElfW(Sym) *)s->data)[sym_index]; + name1 = (char *) s->link->data + sym->st_name; + if (!strcmp(name, name1)) + return sym_index; + sym_index = ((int *)hs->data)[2 + nbuckets + sym_index]; + } + return 0; +} + +/* return elf symbol value, signal error if 'err' is nonzero, decorate + name if FORC */ +ST_FUNC addr_t get_sym_addr(TCCState *s1, const char *name, int err, int forc) +{ + int sym_index; + ElfW(Sym) *sym; + char buf[256]; + if (forc && s1->leading_underscore +#ifdef TCC_TARGET_PE + /* win32-32bit stdcall symbols always have _ already */ + && !strchr(name, '@') +#endif + ) { + buf[0] = '_'; + pstrcpy(buf + 1, sizeof(buf) - 1, name); + name = buf; + } + sym_index = find_elf_sym(s1->symtab, name); + sym = &((ElfW(Sym) *)s1->symtab->data)[sym_index]; + if (!sym_index || sym->st_shndx == SHN_UNDEF) { + if (err) + tcc_error_noabort("%s not defined", name); + return (addr_t)-1; + } + return sym->st_value; +} + +/* return elf symbol value */ +LIBTCCAPI void *tcc_get_symbol(TCCState *s, const char *name) +{ + addr_t addr = get_sym_addr(s, name, 0, 1); + return addr == -1 ? NULL : (void*)(uintptr_t)addr; +} + +/* list elf symbol names and values */ +ST_FUNC void list_elf_symbols(TCCState *s, void *ctx, + void (*symbol_cb)(void *ctx, const char *name, const void *val)) +{ + ElfW(Sym) *sym; + Section *symtab; + int sym_index, end_sym; + const char *name; + unsigned char sym_vis, sym_bind; + + symtab = s->symtab; + end_sym = symtab->data_offset / sizeof (ElfSym); + for (sym_index = 0; sym_index < end_sym; ++sym_index) { + sym = &((ElfW(Sym) *)symtab->data)[sym_index]; + if (sym->st_value) { + name = (char *) symtab->link->data + sym->st_name; + sym_bind = ELFW(ST_BIND)(sym->st_info); + sym_vis = ELFW(ST_VISIBILITY)(sym->st_other); + if (sym_bind == STB_GLOBAL && sym_vis == STV_DEFAULT) + symbol_cb(ctx, name, (void*)(uintptr_t)sym->st_value); + } + } +} + +/* list elf symbol names and values */ +LIBTCCAPI void tcc_list_symbols(TCCState *s, void *ctx, + void (*symbol_cb)(void *ctx, const char *name, const void *val)) +{ + list_elf_symbols(s, ctx, symbol_cb); +} + +#ifndef ELF_OBJ_ONLY +static void +version_add (TCCState *s1) +{ + int i; + ElfW(Sym) *sym; + ElfW(Verneed) *vn = NULL; + Section *symtab; + int sym_index, end_sym, nb_versions = 2, nb_entries = 0; + ElfW(Half) *versym; + const char *name; + + if (0 == nb_sym_versions) + return; + versym_section = new_section(s1, ".gnu.version", SHT_GNU_versym, SHF_ALLOC); + versym_section->sh_entsize = sizeof(ElfW(Half)); + versym_section->link = s1->dynsym; + + /* add needed symbols */ + symtab = s1->dynsym; + end_sym = symtab->data_offset / sizeof (ElfSym); + versym = section_ptr_add(versym_section, end_sym * sizeof(ElfW(Half))); + for (sym_index = 1; sym_index < end_sym; ++sym_index) { + int dllindex, verndx; + sym = &((ElfW(Sym) *)symtab->data)[sym_index]; + if (sym->st_shndx != SHN_UNDEF) + continue; /* defined symbol doesn't need library version */ + name = (char *) symtab->link->data + sym->st_name; + dllindex = find_elf_sym(s1->dynsymtab_section, name); + verndx = (dllindex && dllindex < nb_sym_to_version) + ? sym_to_version[dllindex] : -1; + if (verndx >= 0) { + if (!sym_versions[verndx].out_index) + sym_versions[verndx].out_index = nb_versions++; + versym[sym_index] = sym_versions[verndx].out_index; + } + } + /* generate verneed section, but not when it will be empty. Some + dynamic linkers look at their contents even when DTVERNEEDNUM and + section size is zero. */ + if (nb_versions > 2) { + verneed_section = new_section(s1, ".gnu.version_r", + SHT_GNU_verneed, SHF_ALLOC); + verneed_section->link = s1->dynsym->link; + for (i = nb_sym_versions; i-- > 0;) { + struct sym_version *sv = &sym_versions[i]; + int n_same_libs = 0, prev; + size_t vnofs; + ElfW(Vernaux) *vna = 0; + if (sv->out_index < 1) + continue; + + /* make sure that a DT_NEEDED tag is put */ + /* abitest-tcc fails on older i386-linux with "ld-linux.so.2" DT_NEEDED + ret_int_test... Inconsistency detected by ld.so: dl-minimal.c: 148: + realloc: Assertion `ptr == alloc_last_block' failed! */ + if (strcmp(sv->lib, "ld-linux.so.2")) + tcc_add_dllref(s1, sv->lib, 0); + + vnofs = section_add(verneed_section, sizeof(*vn), 1); + vn = (ElfW(Verneed)*)(verneed_section->data + vnofs); + vn->vn_version = 1; + vn->vn_file = put_elf_str(verneed_section->link, sv->lib); + vn->vn_aux = sizeof (*vn); + do { + prev = sv->prev_same_lib; + if (sv->out_index > 0) { + vna = section_ptr_add(verneed_section, sizeof(*vna)); + vna->vna_hash = elf_hash ((const unsigned char *)sv->version); + vna->vna_flags = 0; + vna->vna_other = sv->out_index; + sv->out_index = -2; + vna->vna_name = put_elf_str(verneed_section->link, sv->version); + vna->vna_next = sizeof (*vna); + n_same_libs++; + } + if (prev >= 0) + sv = &sym_versions[prev]; + } while(prev >= 0); + vna->vna_next = 0; + vn = (ElfW(Verneed)*)(verneed_section->data + vnofs); + vn->vn_cnt = n_same_libs; + vn->vn_next = sizeof(*vn) + n_same_libs * sizeof(*vna); + nb_entries++; + } + if (vn) + vn->vn_next = 0; + verneed_section->sh_info = nb_entries; + } + dt_verneednum = nb_entries; +} +#endif /* ndef ELF_OBJ_ONLY */ + +/* add an elf symbol : check if it is already defined and patch + it. Return symbol index. NOTE that sh_num can be SHN_UNDEF. */ +ST_FUNC int set_elf_sym(Section *s, addr_t value, unsigned long size, + int info, int other, int shndx, const char *name) +{ + TCCState *s1 = s->s1; + ElfW(Sym) *esym; + int sym_bind, sym_index, sym_type, esym_bind; + unsigned char sym_vis, esym_vis, new_vis; + + sym_bind = ELFW(ST_BIND)(info); + sym_type = ELFW(ST_TYPE)(info); + sym_vis = ELFW(ST_VISIBILITY)(other); + + if (sym_bind != STB_LOCAL) { + /* we search global or weak symbols */ + sym_index = find_elf_sym(s, name); + if (!sym_index) + goto do_def; + esym = &((ElfW(Sym) *)s->data)[sym_index]; + if (esym->st_value == value && esym->st_size == size && esym->st_info == info + && esym->st_other == other && esym->st_shndx == shndx) + return sym_index; + if (esym->st_shndx != SHN_UNDEF) { + esym_bind = ELFW(ST_BIND)(esym->st_info); + /* propagate the most constraining visibility */ + /* STV_DEFAULT(0)<STV_PROTECTED(3)<STV_HIDDEN(2)<STV_INTERNAL(1) */ + esym_vis = ELFW(ST_VISIBILITY)(esym->st_other); + if (esym_vis == STV_DEFAULT) { + new_vis = sym_vis; + } else if (sym_vis == STV_DEFAULT) { + new_vis = esym_vis; + } else { + new_vis = (esym_vis < sym_vis) ? esym_vis : sym_vis; + } + esym->st_other = (esym->st_other & ~ELFW(ST_VISIBILITY)(-1)) + | new_vis; + if (shndx == SHN_UNDEF) { + /* ignore adding of undefined symbol if the + corresponding symbol is already defined */ + } else if (sym_bind == STB_GLOBAL && esym_bind == STB_WEAK) { + /* global overrides weak, so patch */ + goto do_patch; + } else if (sym_bind == STB_WEAK && esym_bind == STB_GLOBAL) { + /* weak is ignored if already global */ + } else if (sym_bind == STB_WEAK && esym_bind == STB_WEAK) { + /* keep first-found weak definition, ignore subsequents */ + } else if (sym_vis == STV_HIDDEN || sym_vis == STV_INTERNAL) { + /* ignore hidden symbols after */ + } else if ((esym->st_shndx == SHN_COMMON + || esym->st_shndx == bss_section->sh_num) + && (shndx < SHN_LORESERVE + && shndx != bss_section->sh_num)) { + /* data symbol gets precedence over common/bss */ + goto do_patch; + } else if (shndx == SHN_COMMON || shndx == bss_section->sh_num) { + /* data symbol keeps precedence over common/bss */ + } else if (s->sh_flags & SHF_DYNSYM) { + /* we accept that two DLL define the same symbol */ + } else if (esym->st_other & ST_ASM_SET) { + /* If the existing symbol came from an asm .set + we can override. */ + goto do_patch; + } else { +#if 0 + printf("new_bind=%x new_shndx=%x new_vis=%x old_bind=%x old_shndx=%x old_vis=%x\n", + sym_bind, shndx, new_vis, esym_bind, esym->st_shndx, esym_vis); +#endif + tcc_error_noabort("'%s' defined twice", name); + } + } else { + esym->st_other = other; + do_patch: + esym->st_info = ELFW(ST_INFO)(sym_bind, sym_type); + esym->st_shndx = shndx; + s1->new_undef_sym = 1; + esym->st_value = value; + esym->st_size = size; + } + } else { + do_def: + sym_index = put_elf_sym(s, value, size, + ELFW(ST_INFO)(sym_bind, sym_type), other, + shndx, name); + } + return sym_index; +} + +/* put relocation */ +ST_FUNC void put_elf_reloca(Section *symtab, Section *s, unsigned long offset, + int type, int symbol, addr_t addend) +{ + TCCState *s1 = s->s1; + char buf[256]; + Section *sr; + ElfW_Rel *rel; + + sr = s->reloc; + if (!sr) { + /* if no relocation section, create it */ + snprintf(buf, sizeof(buf), REL_SECTION_FMT, s->name); + /* if the symtab is allocated, then we consider the relocation + are also */ + sr = new_section(s->s1, buf, SHT_RELX, symtab->sh_flags); + sr->sh_entsize = sizeof(ElfW_Rel); + sr->link = symtab; + sr->sh_info = s->sh_num; + s->reloc = sr; + } + rel = section_ptr_add(sr, sizeof(ElfW_Rel)); + rel->r_offset = offset; + rel->r_info = ELFW(R_INFO)(symbol, type); +#if SHT_RELX == SHT_RELA + rel->r_addend = addend; +#endif + if (SHT_RELX != SHT_RELA && addend) + tcc_error_noabort("non-zero addend on REL architecture"); +} + +ST_FUNC void put_elf_reloc(Section *symtab, Section *s, unsigned long offset, + int type, int symbol) +{ + put_elf_reloca(symtab, s, offset, type, symbol, 0); +} + +ST_FUNC struct sym_attr *get_sym_attr(TCCState *s1, int index, int alloc) +{ + int n; + struct sym_attr *tab; + + if (index >= s1->nb_sym_attrs) { + if (!alloc) + return s1->sym_attrs; + /* find immediately bigger power of 2 and reallocate array */ + n = 1; + while (index >= n) + n *= 2; + tab = tcc_realloc(s1->sym_attrs, n * sizeof(*s1->sym_attrs)); + s1->sym_attrs = tab; + memset(s1->sym_attrs + s1->nb_sym_attrs, 0, + (n - s1->nb_sym_attrs) * sizeof(*s1->sym_attrs)); + s1->nb_sym_attrs = n; + } + return &s1->sym_attrs[index]; +} + +static void modify_reloctions_old_to_new(TCCState *s1, Section *s, int *old_to_new_syms) +{ + int i, type, sym_index; + Section *sr; + ElfW_Rel *rel; + + for(i = 1; i < s1->nb_sections; i++) { + sr = s1->sections[i]; + if (sr->sh_type == SHT_RELX && sr->link == s) { + for_each_elem(sr, 0, rel, ElfW_Rel) { + sym_index = ELFW(R_SYM)(rel->r_info); + type = ELFW(R_TYPE)(rel->r_info); + sym_index = old_to_new_syms[sym_index]; + rel->r_info = ELFW(R_INFO)(sym_index, type); + } + } + } +} + +/* In an ELF file symbol table, the local symbols must appear below + the global and weak ones. Since TCC cannot sort it while generating + the code, we must do it after. All the relocation tables are also + modified to take into account the symbol table sorting */ +static void sort_syms(TCCState *s1, Section *s) +{ + int *old_to_new_syms; + ElfW(Sym) *new_syms; + int nb_syms, i; + ElfW(Sym) *p, *q; + + nb_syms = s->data_offset / sizeof(ElfW(Sym)); + new_syms = tcc_malloc(nb_syms * sizeof(ElfW(Sym))); + old_to_new_syms = tcc_malloc(nb_syms * sizeof(int)); + + /* first pass for local symbols */ + p = (ElfW(Sym) *)s->data; + q = new_syms; + for(i = 0; i < nb_syms; i++) { + if (ELFW(ST_BIND)(p->st_info) == STB_LOCAL) { + old_to_new_syms[i] = q - new_syms; + *q++ = *p; + } + p++; + } + /* save the number of local symbols in section header */ + if( s->sh_size ) /* this 'if' makes IDA happy */ + s->sh_info = q - new_syms; + + /* then second pass for non local symbols */ + p = (ElfW(Sym) *)s->data; + for(i = 0; i < nb_syms; i++) { + if (ELFW(ST_BIND)(p->st_info) != STB_LOCAL) { + old_to_new_syms[i] = q - new_syms; + *q++ = *p; + } + p++; + } + + /* we copy the new symbols to the old */ + memcpy(s->data, new_syms, nb_syms * sizeof(ElfW(Sym))); + tcc_free(new_syms); + + modify_reloctions_old_to_new(s1, s, old_to_new_syms); + + tcc_free(old_to_new_syms); +} + +#ifndef ELF_OBJ_ONLY +/* See: https://flapenguin.me/elf-dt-gnu-hash */ +#define ELFCLASS_BITS (PTR_SIZE * 8) + +static Section *create_gnu_hash(TCCState *s1) +{ + int nb_syms, i, ndef, nbuckets, symoffset, bloom_size, bloom_shift; + ElfW(Sym) *p; + Section *gnu_hash; + Section *dynsym = s1->dynsym; + Elf32_Word *ptr; + + gnu_hash = new_section(s1, ".gnu.hash", SHT_GNU_HASH, SHF_ALLOC); + gnu_hash->link = dynsym->hash->link; + + nb_syms = dynsym->data_offset / sizeof(ElfW(Sym)); + + /* count def symbols */ + ndef = 0; + p = (ElfW(Sym) *)dynsym->data; + for(i = 0; i < nb_syms; i++, p++) + ndef += p->st_shndx != SHN_UNDEF; + + /* calculate gnu hash sizes and fill header */ + nbuckets = ndef / 4 + 1; + symoffset = nb_syms - ndef; + bloom_shift = PTR_SIZE == 8 ? 6 : 5; + bloom_size = 1; /* must be power of two */ + while (ndef >= bloom_size * (1 << (bloom_shift - 3))) + bloom_size *= 2; + ptr = section_ptr_add(gnu_hash, 4 * 4 + + PTR_SIZE * bloom_size + + nbuckets * 4 + + ndef * 4); + ptr[0] = nbuckets; + ptr[1] = symoffset; + ptr[2] = bloom_size; + ptr[3] = bloom_shift; + return gnu_hash; +} + +static Elf32_Word elf_gnu_hash (const unsigned char *name) +{ + Elf32_Word h = 5381; + unsigned char c; + + while ((c = *name++)) + h = h * 33 + c; + return h; +} + +static void update_gnu_hash(TCCState *s1, Section *gnu_hash) +{ + int *old_to_new_syms; + ElfW(Sym) *new_syms; + int nb_syms, i, nbuckets, bloom_size, bloom_shift; + ElfW(Sym) *p, *q; + Section *vs; + Section *dynsym = s1->dynsym; + Elf32_Word *ptr, *buckets, *chain, *hash; + unsigned int *nextbuck; + addr_t *bloom; + unsigned char *strtab; + struct { int first, last; } *buck; + + strtab = dynsym->link->data; + nb_syms = dynsym->data_offset / sizeof(ElfW(Sym)); + new_syms = tcc_malloc(nb_syms * sizeof(ElfW(Sym))); + old_to_new_syms = tcc_malloc(nb_syms * sizeof(int)); + hash = tcc_malloc(nb_syms * sizeof(Elf32_Word)); + nextbuck = tcc_malloc(nb_syms * sizeof(int)); + + /* calculate hashes and copy undefs */ + p = (ElfW(Sym) *)dynsym->data; + q = new_syms; + for(i = 0; i < nb_syms; i++, p++) { + if (p->st_shndx == SHN_UNDEF) { + old_to_new_syms[i] = q - new_syms; + *q++ = *p; + } + else + hash[i] = elf_gnu_hash(strtab + p->st_name); + } + + ptr = (Elf32_Word *) gnu_hash->data; + nbuckets = ptr[0]; + bloom_size = ptr[2]; + bloom_shift = ptr[3]; + bloom = (addr_t *) (void *) &ptr[4]; + buckets = (Elf32_Word*) (void *) &bloom[bloom_size]; + chain = &buckets[nbuckets]; + buck = tcc_malloc(nbuckets * sizeof(*buck)); + + if (gnu_hash->data_offset != 4 * 4 + + PTR_SIZE * bloom_size + + nbuckets * 4 + + (nb_syms - (q - new_syms)) * 4) + tcc_error_noabort ("gnu_hash size incorrect"); + + /* find buckets */ + for(i = 0; i < nbuckets; i++) + buck[i].first = -1; + + p = (ElfW(Sym) *)dynsym->data; + for(i = 0; i < nb_syms; i++, p++) + if (p->st_shndx != SHN_UNDEF) { + int bucket = hash[i] % nbuckets; + + if (buck[bucket].first == -1) + buck[bucket].first = buck[bucket].last = i; + else { + nextbuck[buck[bucket].last] = i; + buck[bucket].last = i; + } + } + + /* fill buckets/chains/bloom and sort symbols */ + p = (ElfW(Sym) *)dynsym->data; + for(i = 0; i < nbuckets; i++) { + int cur = buck[i].first; + + if (cur != -1) { + buckets[i] = q - new_syms; + for (;;) { + old_to_new_syms[cur] = q - new_syms; + *q++ = p[cur]; + *chain++ = hash[cur] & ~1; + bloom[(hash[cur] / ELFCLASS_BITS) % bloom_size] |= + (addr_t)1 << (hash[cur] % ELFCLASS_BITS) | + (addr_t)1 << ((hash[cur] >> bloom_shift) % ELFCLASS_BITS); + if (cur == buck[i].last) + break; + cur = nextbuck[cur]; + } + chain[-1] |= 1; + } + } + + memcpy(dynsym->data, new_syms, nb_syms * sizeof(ElfW(Sym))); + tcc_free(new_syms); + tcc_free(hash); + tcc_free(buck); + tcc_free(nextbuck); + + modify_reloctions_old_to_new(s1, dynsym, old_to_new_syms); + + /* modify the versions */ + vs = versym_section; + if (vs) { + ElfW(Half) *newver, *versym = (ElfW(Half) *)vs->data; + + if (1/*versym*/) { + newver = tcc_malloc(nb_syms * sizeof(*newver)); + for (i = 0; i < nb_syms; i++) + newver[old_to_new_syms[i]] = versym[i]; + memcpy(vs->data, newver, nb_syms * sizeof(*newver)); + tcc_free(newver); + } + } + + tcc_free(old_to_new_syms); + + /* rebuild hash */ + ptr = (Elf32_Word *) dynsym->hash->data; + rebuild_hash(dynsym, ptr[0]); +} +#endif /* ELF_OBJ_ONLY */ + +/* relocate symbol table, resolve undefined symbols if do_resolve is + true and output error if undefined symbol. */ +ST_FUNC void relocate_syms(TCCState *s1, Section *symtab, int do_resolve) +{ + ElfW(Sym) *sym; + int sym_bind, sh_num; + const char *name; + + for_each_elem(symtab, 1, sym, ElfW(Sym)) { + sh_num = sym->st_shndx; + if (sh_num == SHN_UNDEF) { + if (do_resolve == 2) /* relocating dynsym */ + continue; + name = (char *) s1->symtab->link->data + sym->st_name; + /* Use ld.so to resolve symbol for us (for tcc -run) */ + if (do_resolve) { +#if defined TCC_IS_NATIVE && !defined TCC_TARGET_PE + /* dlsym() needs the undecorated name. */ + void *addr = dlsym(RTLD_DEFAULT, &name[s1->leading_underscore]); +#if TARGETOS_OpenBSD || TARGETOS_FreeBSD || TARGETOS_NetBSD || TARGETOS_ANDROID + if (addr == NULL) { + int i; + for (i = 0; i < s1->nb_loaded_dlls; i++) + if ((addr = dlsym(s1->loaded_dlls[i]->handle, name))) + break; + } +#endif + if (addr) { + sym->st_value = (addr_t) addr; +#ifdef DEBUG_RELOC + printf ("relocate_sym: %s -> 0x%lx\n", name, sym->st_value); +#endif + goto found; + } +#endif + /* if dynamic symbol exist, it will be used in relocate_section */ + } else if (s1->dynsym && find_elf_sym(s1->dynsym, name)) + goto found; + /* XXX: _fp_hw seems to be part of the ABI, so we ignore + it */ + if (!strcmp(name, "_fp_hw")) + goto found; + /* only weak symbols are accepted to be undefined. Their + value is zero */ + sym_bind = ELFW(ST_BIND)(sym->st_info); + if (sym_bind == STB_WEAK) + sym->st_value = 0; + else + tcc_error_noabort("undefined symbol '%s'", name); + + } else if (sh_num < SHN_LORESERVE) { + /* add section base */ + sym->st_value += s1->sections[sym->st_shndx]->sh_addr; + } + found: ; + } +} + +/* relocate a given section (CPU dependent) by applying the relocations + in the associated relocation section */ +static void relocate_section(TCCState *s1, Section *s, Section *sr) +{ + ElfW_Rel *rel; + ElfW(Sym) *sym; + int type, sym_index; + unsigned char *ptr; + addr_t tgt, addr; + int is_dwarf = s->sh_num >= s1->dwlo && s->sh_num < s1->dwhi; + + qrel = (ElfW_Rel *)sr->data; + for_each_elem(sr, 0, rel, ElfW_Rel) { + ptr = s->data + rel->r_offset; + sym_index = ELFW(R_SYM)(rel->r_info); + sym = &((ElfW(Sym) *)symtab_section->data)[sym_index]; + type = ELFW(R_TYPE)(rel->r_info); + tgt = sym->st_value; +#if SHT_RELX == SHT_RELA + tgt += rel->r_addend; +#endif + if (is_dwarf && type == R_DATA_32DW + && sym->st_shndx >= s1->dwlo && sym->st_shndx < s1->dwhi) { + /* dwarf section relocation to each other */ + add32le(ptr, tgt - s1->sections[sym->st_shndx]->sh_addr); + continue; + } + addr = s->sh_addr + rel->r_offset; + relocate(s1, rel, type, ptr, addr, tgt); + } +#ifndef ELF_OBJ_ONLY + /* if the relocation is allocated, we change its symbol table */ + if (sr->sh_flags & SHF_ALLOC) { + sr->link = s1->dynsym; + if (s1->output_type & TCC_OUTPUT_DYN) { + size_t r = (uint8_t*)qrel - sr->data; + if (sizeof ((Stab_Sym*)0)->n_value < PTR_SIZE + && 0 == strcmp(s->name, ".stab")) + r = 0; /* cannot apply 64bit relocation to 32bit value */ + sr->data_offset = sr->sh_size = r; +#ifdef CONFIG_TCC_PIE + if (r && 0 == (s->sh_flags & SHF_WRITE)) + tcc_warning("%d relocations to ro-section %s", (unsigned)(r / sizeof *qrel), s->name); +#endif + } + } +#endif +} + +/* relocate all sections */ +ST_FUNC void relocate_sections(TCCState *s1) +{ + int i; + Section *s, *sr; + + for (i = 1; i < s1->nb_sections; ++i) { + sr = s1->sections[i]; + if (sr->sh_type != SHT_RELX) + continue; + s = s1->sections[sr->sh_info]; +#ifndef TCC_TARGET_MACHO + if (s != s1->got + || s1->static_link + || s1->output_type == TCC_OUTPUT_MEMORY) +#endif + { + relocate_section(s1, s, sr); + } +#ifndef ELF_OBJ_ONLY + if (sr->sh_flags & SHF_ALLOC) { + ElfW_Rel *rel; + /* relocate relocation table in 'sr' */ + for_each_elem(sr, 0, rel, ElfW_Rel) + rel->r_offset += s->sh_addr; + } +#endif + } +} + +#ifndef ELF_OBJ_ONLY +/* count the number of dynamic relocations so that we can reserve + their space */ +static int prepare_dynamic_rel(TCCState *s1, Section *sr) +{ + int count = 0; +#if defined(TCC_TARGET_I386) || defined(TCC_TARGET_X86_64) || \ + defined(TCC_TARGET_ARM) || defined(TCC_TARGET_ARM64) || \ + defined(TCC_TARGET_RISCV64) + ElfW_Rel *rel; + for_each_elem(sr, 0, rel, ElfW_Rel) { + int sym_index = ELFW(R_SYM)(rel->r_info); + int type = ELFW(R_TYPE)(rel->r_info); + switch(type) { +#if defined(TCC_TARGET_I386) + case R_386_32: + if (!get_sym_attr(s1, sym_index, 0)->dyn_index + && ((ElfW(Sym)*)symtab_section->data + sym_index)->st_shndx == SHN_UNDEF) { + /* don't fixup unresolved (weak) symbols */ + rel->r_info = ELFW(R_INFO)(sym_index, R_386_RELATIVE); + break; + } +#elif defined(TCC_TARGET_X86_64) + case R_X86_64_32: + case R_X86_64_32S: + case R_X86_64_64: +#elif defined(TCC_TARGET_ARM) + case R_ARM_ABS32: + case R_ARM_TARGET1: +#elif defined(TCC_TARGET_ARM64) + case R_AARCH64_ABS32: + case R_AARCH64_ABS64: +#elif defined(TCC_TARGET_RISCV64) + case R_RISCV_32: + case R_RISCV_64: +#endif + count++; + break; +#if defined(TCC_TARGET_I386) + case R_386_PC32: +#elif defined(TCC_TARGET_X86_64) + case R_X86_64_PC32: + { + ElfW(Sym) *sym = &((ElfW(Sym) *)symtab_section->data)[sym_index]; + /* Hidden defined symbols can and must be resolved locally. + We're misusing a PLT32 reloc for this, as that's always + resolved to its address even in shared libs. */ + if (sym->st_shndx != SHN_UNDEF && + ELFW(ST_VISIBILITY)(sym->st_other) == STV_HIDDEN) { + rel->r_info = ELFW(R_INFO)(sym_index, R_X86_64_PLT32); + break; + } + } +#elif defined(TCC_TARGET_ARM64) + case R_AARCH64_PREL32: +#endif + if (s1->output_type != TCC_OUTPUT_DLL) + break; + if (get_sym_attr(s1, sym_index, 0)->dyn_index) + count++; + break; + default: + break; + } + } +#endif + return count; +} +#endif + +#ifdef NEED_BUILD_GOT +static int build_got(TCCState *s1) +{ + /* if no got, then create it */ + s1->got = new_section(s1, ".got", SHT_PROGBITS, SHF_ALLOC | SHF_WRITE); + s1->got->sh_entsize = 4; + /* keep space for _DYNAMIC pointer and two dummy got entries */ + section_ptr_add(s1->got, 3 * PTR_SIZE); + return set_elf_sym(symtab_section, 0, 0, ELFW(ST_INFO)(STB_GLOBAL, STT_OBJECT), + 0, s1->got->sh_num, "_GLOBAL_OFFSET_TABLE_"); +} + +/* Create a GOT and (for function call) a PLT entry corresponding to a symbol + in s1->symtab. When creating the dynamic symbol table entry for the GOT + relocation, use 'size' and 'info' for the corresponding symbol metadata. + Returns the offset of the GOT or (if any) PLT entry. */ +static struct sym_attr * put_got_entry(TCCState *s1, int dyn_reloc_type, + int sym_index) +{ + int need_plt_entry; + const char *name; + ElfW(Sym) *sym; + struct sym_attr *attr; + unsigned got_offset; + char plt_name[200]; + int len; + Section *s_rel; + + need_plt_entry = (dyn_reloc_type == R_JMP_SLOT); + attr = get_sym_attr(s1, sym_index, 1); + + /* In case a function is both called and its address taken 2 GOT entries + are created, one for taking the address (GOT) and the other for the PLT + entry (PLTGOT). */ + if (need_plt_entry ? attr->plt_offset : attr->got_offset) + return attr; + + s_rel = s1->got; + if (need_plt_entry) { + if (!s1->plt) { + s1->plt = new_section(s1, ".plt", SHT_PROGBITS, SHF_ALLOC | SHF_EXECINSTR); + s1->plt->sh_entsize = 4; + } + s_rel = s1->plt; + } + + /* create the GOT entry */ + got_offset = s1->got->data_offset; + section_ptr_add(s1->got, PTR_SIZE); + + /* Create the GOT relocation that will insert the address of the object or + function of interest in the GOT entry. This is a static relocation for + memory output (dlsym will give us the address of symbols) and dynamic + relocation otherwise (executable and DLLs). The relocation should be + done lazily for GOT entry with *_JUMP_SLOT relocation type (the one + associated to a PLT entry) but is currently done at load time for an + unknown reason. */ + + sym = &((ElfW(Sym) *) symtab_section->data)[sym_index]; + name = (char *) symtab_section->link->data + sym->st_name; + //printf("sym %d %s\n", need_plt_entry, name); + + if (s1->dynsym) { + if (ELFW(ST_BIND)(sym->st_info) == STB_LOCAL) { + /* Hack alarm. We don't want to emit dynamic symbols + and symbol based relocs for STB_LOCAL symbols, but rather + want to resolve them directly. At this point the symbol + values aren't final yet, so we must defer this. We will later + have to create a RELATIVE reloc anyway, so we misuse the + relocation slot to smuggle the symbol reference until + fill_local_got_entries. Not that the sym_index is + relative to symtab_section, not s1->dynsym! Nevertheless + we use s1->dyn_sym so that if this is the first call + that got->reloc is correctly created. Also note that + RELATIVE relocs are not normally created for the .got, + so the types serves as a marker for later (and is retained + also for the final output, which is okay because then the + got is just normal data). */ + put_elf_reloc(s1->dynsym, s1->got, got_offset, R_RELATIVE, + sym_index); + } else { + if (0 == attr->dyn_index) + attr->dyn_index = set_elf_sym(s1->dynsym, sym->st_value, + sym->st_size, sym->st_info, 0, + sym->st_shndx, name); + put_elf_reloc(s1->dynsym, s_rel, got_offset, dyn_reloc_type, + attr->dyn_index); + } + } else { + put_elf_reloc(symtab_section, s1->got, got_offset, dyn_reloc_type, + sym_index); + } + + if (need_plt_entry) { + attr->plt_offset = create_plt_entry(s1, got_offset, attr); + + /* create a symbol 'sym@plt' for the PLT jump vector */ + len = strlen(name); + if (len > sizeof plt_name - 5) + len = sizeof plt_name - 5; + memcpy(plt_name, name, len); + strcpy(plt_name + len, "@plt"); + attr->plt_sym = put_elf_sym(s1->symtab, attr->plt_offset, 0, + ELFW(ST_INFO)(STB_GLOBAL, STT_FUNC), 0, s1->plt->sh_num, plt_name); + } else { + attr->got_offset = got_offset; + } + + return attr; +} + +/* build GOT and PLT entries */ +/* Two passes because R_JMP_SLOT should become first. Some targets + (arm, arm64) do not allow mixing R_JMP_SLOT and R_GLOB_DAT. */ +ST_FUNC void build_got_entries(TCCState *s1, int got_sym) +{ + Section *s; + ElfW_Rel *rel; + ElfW(Sym) *sym; + int i, type, gotplt_entry, reloc_type, sym_index; + struct sym_attr *attr; + int pass = 0; +redo: + for(i = 1; i < s1->nb_sections; i++) { + s = s1->sections[i]; + if (s->sh_type != SHT_RELX) + continue; + /* no need to handle got relocations */ + if (s->link != symtab_section) + continue; + for_each_elem(s, 0, rel, ElfW_Rel) { + type = ELFW(R_TYPE)(rel->r_info); + gotplt_entry = gotplt_entry_type(type); + if (gotplt_entry == -1) { + tcc_error_noabort ("Unknown relocation type for got: %d", type); + continue; + } + sym_index = ELFW(R_SYM)(rel->r_info); + sym = &((ElfW(Sym) *)symtab_section->data)[sym_index]; + + if (gotplt_entry == NO_GOTPLT_ENTRY) { + continue; + } + + /* Automatically create PLT/GOT [entry] if it is an undefined + reference (resolved at runtime), or the symbol is absolute, + probably created by tcc_add_symbol, and thus on 64-bit + targets might be too far from application code. */ + if (gotplt_entry == AUTO_GOTPLT_ENTRY) { + if (sym->st_shndx == SHN_UNDEF) { + ElfW(Sym) *esym; + int dynindex; + if (!PCRELATIVE_DLLPLT + && (s1->output_type & TCC_OUTPUT_DYN)) + continue; + /* Relocations for UNDEF symbols would normally need + to be transferred into the executable or shared object. + If that were done AUTO_GOTPLT_ENTRY wouldn't exist. + But TCC doesn't do that (at least for exes), so we + need to resolve all such relocs locally. And that + means PLT slots for functions in DLLs and COPY relocs for + data symbols. COPY relocs were generated in + bind_exe_dynsyms (and the symbol adjusted to be defined), + and for functions we were generated a dynamic symbol + of function type. */ + if (s1->dynsym) { + /* dynsym isn't set for -run :-/ */ + dynindex = get_sym_attr(s1, sym_index, 0)->dyn_index; + esym = (ElfW(Sym) *)s1->dynsym->data + dynindex; + if (dynindex + && (ELFW(ST_TYPE)(esym->st_info) == STT_FUNC + || (ELFW(ST_TYPE)(esym->st_info) == STT_NOTYPE + && ELFW(ST_TYPE)(sym->st_info) == STT_FUNC))) + goto jmp_slot; + } + } else if (sym->st_shndx == SHN_ABS) { + if (sym->st_value == 0) /* from tcc_add_btstub() */ + continue; +#ifndef TCC_TARGET_ARM + if (PTR_SIZE != 8) + continue; +#endif + /* from tcc_add_symbol(): on 64 bit platforms these + need to go through .got */ + } else + continue; + } + +#ifdef TCC_TARGET_X86_64 + if ((type == R_X86_64_PLT32 || type == R_X86_64_PC32) && + sym->st_shndx != SHN_UNDEF && + (ELFW(ST_VISIBILITY)(sym->st_other) != STV_DEFAULT || + ELFW(ST_BIND)(sym->st_info) == STB_LOCAL || + s1->output_type & TCC_OUTPUT_EXE)) { + if (pass != 0) + continue; + rel->r_info = ELFW(R_INFO)(sym_index, R_X86_64_PC32); + continue; + } +#endif + reloc_type = code_reloc(type); + if (reloc_type == -1) { + tcc_error_noabort ("Unknown relocation type: %d", type); + continue; + } + + if (reloc_type != 0) { + jmp_slot: + if (pass != 0) + continue; + reloc_type = R_JMP_SLOT; + } else { + if (pass != 1) + continue; + reloc_type = R_GLOB_DAT; + } + + if (!s1->got) + got_sym = build_got(s1); + + if (gotplt_entry == BUILD_GOT_ONLY) + continue; + + attr = put_got_entry(s1, reloc_type, sym_index); + + if (reloc_type == R_JMP_SLOT) + rel->r_info = ELFW(R_INFO)(attr->plt_sym, type); + } + } + if (++pass < 2) + goto redo; + /* .rel.plt refers to .got actually */ + if (s1->plt && s1->plt->reloc) + s1->plt->reloc->sh_info = s1->got->sh_num; + if (got_sym) /* set size */ + ((ElfW(Sym)*)symtab_section->data)[got_sym].st_size = s1->got->data_offset; +} +#endif /* def NEED_BUILD_GOT */ + +ST_FUNC int set_global_sym(TCCState *s1, const char *name, Section *sec, addr_t offs) +{ + int shn = sec ? sec->sh_num : offs || !name ? SHN_ABS : SHN_UNDEF; + if (sec && offs == -1) + offs = sec->data_offset; + return set_elf_sym(symtab_section, offs, 0, + ELFW(ST_INFO)(name ? STB_GLOBAL : STB_LOCAL, STT_NOTYPE), 0, shn, name); +} + +static void add_init_array_defines(TCCState *s1, const char *section_name) +{ + Section *s; + addr_t end_offset; + char buf[1024]; + s = have_section(s1, section_name); + if (!s || !(s->sh_flags & SHF_ALLOC)) { + end_offset = 0; + s = data_section; + } else { + end_offset = s->data_offset; + } + snprintf(buf, sizeof(buf), "__%s_start", section_name + 1); + set_global_sym(s1, buf, s, 0); + snprintf(buf, sizeof(buf), "__%s_end", section_name + 1); + set_global_sym(s1, buf, s, end_offset); +} + +ST_FUNC void add_array (TCCState *s1, const char *sec, int c) +{ + Section *s; + s = find_section(s1, sec); + s->sh_flags = shf_RELRO; + s->sh_type = sec[1] == 'i' ? SHT_INIT_ARRAY : SHT_FINI_ARRAY; + put_elf_reloc (s1->symtab, s, s->data_offset, R_DATA_PTR, c); + section_ptr_add(s, PTR_SIZE); +} + +#ifdef CONFIG_TCC_BCHECK +ST_FUNC void tcc_add_bcheck(TCCState *s1) +{ + if (0 == s1->do_bounds_check) + return; + section_ptr_add(bounds_section, sizeof(addr_t)); +} +#endif + +/* set symbol to STB_LOCAL and resolve. The point is to not export it as + a dynamic symbol to allow so's to have one each with a different value. */ +static void set_local_sym(TCCState *s1, const char *name, Section *s, int offset) +{ + int c = find_elf_sym(s1->symtab, name); + if (c) { + ElfW(Sym) *esym = (ElfW(Sym)*)s1->symtab->data + c; + esym->st_info = ELFW(ST_INFO)(STB_LOCAL, STT_NOTYPE); + esym->st_value = offset; + esym->st_shndx = s->sh_num; + } +} + +/* avoid generating debug/test_coverage code for stub functions */ +static void tcc_compile_string_no_debug(TCCState *s, const char *str) +{ + int save_do_debug = s->do_debug; + int save_test_coverage = s->test_coverage; + + s->do_debug = 0; + s->test_coverage = 0; + tcc_compile_string(s, str); + s->do_debug = save_do_debug; + s->test_coverage = save_test_coverage; +} + +#ifdef CONFIG_TCC_BACKTRACE +static void put_ptr(TCCState *s1, Section *s, int offs) +{ + int c; + c = set_global_sym(s1, NULL, s, offs); + s = data_section; + put_elf_reloc (s1->symtab, s, s->data_offset, R_DATA_PTR, c); + section_ptr_add(s, PTR_SIZE); +} + +ST_FUNC void tcc_add_btstub(TCCState *s1) +{ + Section *s; + int n, o; + CString cstr; + + s = data_section; + /* Align to PTR_SIZE */ + section_ptr_add(s, -s->data_offset & (PTR_SIZE - 1)); + o = s->data_offset; + /* create (part of) a struct rt_context (see tccrun.c) */ + if (s1->dwarf) { + put_ptr(s1, dwarf_line_section, 0); + put_ptr(s1, dwarf_line_section, -1); + if (s1->dwarf >= 5) + put_ptr(s1, dwarf_line_str_section, 0); + else + put_ptr(s1, dwarf_str_section, 0); + } + else + { + put_ptr(s1, stab_section, 0); + put_ptr(s1, stab_section, -1); + put_ptr(s1, stab_section->link, 0); + } + *(addr_t *)section_ptr_add(s, PTR_SIZE) = s1->dwarf; + /* skip esym_start/esym_end/elf_str (not loaded) */ + section_ptr_add(s, 3 * PTR_SIZE); + /* prog_base : local nameless symbol with offset 0 at SHN_ABS */ + put_ptr(s1, NULL, 0); +#if defined TCC_TARGET_MACHO + /* adjust for __PAGEZERO */ + if (s1->dwarf == 0 && s1->output_type == TCC_OUTPUT_EXE) + write64le(data_section->data + data_section->data_offset - PTR_SIZE, + (uint64_t)1 << 32); +#endif + n = 2 * PTR_SIZE; +#ifdef CONFIG_TCC_BCHECK + if (s1->do_bounds_check) { + put_ptr(s1, bounds_section, 0); + n -= PTR_SIZE; + } +#endif + section_ptr_add(s, n); + cstr_new(&cstr); + cstr_printf(&cstr, + "extern void __bt_init(),__bt_exit(),__bt_init_dll();" + "static void *__rt_info[];" + "__attribute__((constructor)) static void __bt_init_rt(){"); +#ifdef TCC_TARGET_PE + if (s1->output_type == TCC_OUTPUT_DLL) +#ifdef CONFIG_TCC_BCHECK + cstr_printf(&cstr, "__bt_init_dll(%d);", s1->do_bounds_check); +#else + cstr_printf(&cstr, "__bt_init_dll(0);"); +#endif +#endif + cstr_printf(&cstr, "__bt_init(__rt_info,%d);}", + s1->output_type == TCC_OUTPUT_DLL ? 0 : s1->rt_num_callers + 1); + /* In case dlcose is called by application */ + cstr_printf(&cstr, + "__attribute__((destructor)) static void __bt_exit_rt(){" + "__bt_exit(__rt_info);}"); + tcc_compile_string_no_debug(s1, cstr.data); + cstr_free(&cstr); + set_local_sym(s1, &"___rt_info"[!s1->leading_underscore], s, o); +} +#endif /* def CONFIG_TCC_BACKTRACE */ + +static void tcc_tcov_add_file(TCCState *s1, const char *filename) +{ + CString cstr; + void *ptr; + char wd[1024]; + + if (tcov_section == NULL) + return; + section_ptr_add(tcov_section, 1); + write32le (tcov_section->data, tcov_section->data_offset); + + cstr_new (&cstr); + if (filename[0] == '/') + cstr_printf (&cstr, "%s.tcov", filename); + else { + getcwd (wd, sizeof(wd)); + cstr_printf (&cstr, "%s/%s.tcov", wd, filename); + } + ptr = section_ptr_add(tcov_section, cstr.size + 1); + strcpy((char *)ptr, cstr.data); + unlink((char *)ptr); +#ifdef _WIN32 + normalize_slashes((char *)ptr); +#endif + cstr_free (&cstr); + + cstr_new(&cstr); + cstr_printf(&cstr, + "extern char *__tcov_data[];" + "extern void __store_test_coverage ();" + "__attribute__((destructor)) static void __tcov_exit() {" + "__store_test_coverage(__tcov_data);" + "}"); + tcc_compile_string_no_debug(s1, cstr.data); + cstr_free(&cstr); + set_local_sym(s1, &"___tcov_data"[!s1->leading_underscore], tcov_section, 0); +} + +#ifndef TCC_TARGET_PE +/* add tcc runtime libraries */ +ST_FUNC void tcc_add_runtime(TCCState *s1) +{ + s1->filetype = 0; + +#ifdef CONFIG_TCC_BCHECK + tcc_add_bcheck(s1); +#endif + tcc_add_pragma_libs(s1); + + /* add libc */ + if (!s1->nostdlib) { + int lpthread = s1->option_pthread; + +#ifdef CONFIG_TCC_BCHECK + if (s1->do_bounds_check && s1->output_type != TCC_OUTPUT_DLL) { + tcc_add_support(s1, "bcheck.o"); +# if !(TARGETOS_OpenBSD || TARGETOS_NetBSD) + tcc_add_library_err(s1, "dl"); +# endif + lpthread = 1; + } +#endif +#ifdef CONFIG_TCC_BACKTRACE + if (s1->do_backtrace) { + if (s1->output_type & TCC_OUTPUT_EXE) + tcc_add_support(s1, "bt-exe.o"); + if (s1->output_type != TCC_OUTPUT_DLL) + tcc_add_support(s1, "bt-log.o"); + if (s1->output_type != TCC_OUTPUT_MEMORY) + tcc_add_btstub(s1); + } +#endif + if (lpthread) + tcc_add_library_err(s1, "pthread"); + tcc_add_library_err(s1, "c"); +#ifdef TCC_LIBGCC + if (!s1->static_link) { + if (TCC_LIBGCC[0] == '/') + tcc_add_file(s1, TCC_LIBGCC); + else + tcc_add_dll(s1, TCC_LIBGCC, 0); + } +#endif +#if defined TCC_TARGET_ARM && TARGETOS_FreeBSD + tcc_add_library_err(s1, "gcc_s"); // unwind code +#endif + if (TCC_LIBTCC1[0]) + tcc_add_support(s1, TCC_LIBTCC1); + + /* add crt end if not memory output */ + if (s1->output_type != TCC_OUTPUT_MEMORY) { +#if defined TCC_TARGET_MACHO + /* nothing to do */ +#elif TARGETOS_FreeBSD || TARGETOS_NetBSD + if (s1->output_type & TCC_OUTPUT_DYN) + tcc_add_crt(s1, "crtendS.o"); + else + tcc_add_crt(s1, "crtend.o"); + tcc_add_crt(s1, "crtn.o"); +#elif TARGETOS_OpenBSD + if (s1->output_type == TCC_OUTPUT_DLL) + tcc_add_crt(s1, "crtendS.o"); + else + tcc_add_crt(s1, "crtend.o"); +#elif TARGETOS_ANDROID + if (s1->output_type == TCC_OUTPUT_DLL) + tcc_add_crt(s1, "crtend_so.o"); + else + tcc_add_crt(s1, "crtend_android.o"); +#else + tcc_add_crt(s1, "crtn.o"); +#endif + } + } +} +#endif /* ndef TCC_TARGET_PE */ + +/* add various standard linker symbols (must be done after the + sections are filled (for example after allocating common + symbols)) */ +static void tcc_add_linker_symbols(TCCState *s1) +{ + char buf[1024]; + int i; + Section *s; + + set_global_sym(s1, "_etext", text_section, -1); + set_global_sym(s1, "_edata", data_section, -1); + set_global_sym(s1, "_end", bss_section, -1); +#if TARGETOS_OpenBSD + set_global_sym(s1, "__executable_start", NULL, ELF_START_ADDR); +#endif +#ifdef TCC_TARGET_RISCV64 + /* XXX should be .sdata+0x800, not .data+0x800 */ + set_global_sym(s1, "__global_pointer$", data_section, 0x800); +#endif + /* horrible new standard ldscript defines */ + add_init_array_defines(s1, ".preinit_array"); + add_init_array_defines(s1, ".init_array"); + add_init_array_defines(s1, ".fini_array"); + /* add start and stop symbols for sections whose name can be + expressed in C */ + for(i = 1; i < s1->nb_sections; i++) { + s = s1->sections[i]; + if ((s->sh_flags & SHF_ALLOC) + && (s->sh_type == SHT_PROGBITS + || s->sh_type == SHT_STRTAB)) { + const char *p; + /* check if section name can be expressed in C */ + p = s->name; + for(;;) { + int c = *p; + if (!c) + break; + if (!isid(c) && !isnum(c)) + goto next_sec; + p++; + } + snprintf(buf, sizeof(buf), "__start_%s", s->name); + set_global_sym(s1, buf, s, 0); + snprintf(buf, sizeof(buf), "__stop_%s", s->name); + set_global_sym(s1, buf, s, -1); + } + next_sec: ; + } +} + +ST_FUNC void resolve_common_syms(TCCState *s1) +{ + ElfW(Sym) *sym; + + /* Allocate common symbols in BSS. */ + for_each_elem(symtab_section, 1, sym, ElfW(Sym)) { + if (sym->st_shndx == SHN_COMMON) { + /* symbol alignment is in st_value for SHN_COMMONs */ + sym->st_value = section_add(bss_section, sym->st_size, + sym->st_value); + sym->st_shndx = bss_section->sh_num; + } + } + + /* Now assign linker provided symbols their value. */ + tcc_add_linker_symbols(s1); +} + +#ifndef ELF_OBJ_ONLY +ST_FUNC void fill_got_entry(TCCState *s1, ElfW_Rel *rel) +{ + int sym_index = ELFW(R_SYM) (rel->r_info); + ElfW(Sym) *sym = &((ElfW(Sym) *) symtab_section->data)[sym_index]; + struct sym_attr *attr = get_sym_attr(s1, sym_index, 0); + unsigned offset = attr->got_offset; + + if (0 == offset) + return; + section_reserve(s1->got, offset + PTR_SIZE); +#if PTR_SIZE == 8 + write64le(s1->got->data + offset, sym->st_value); +#else + write32le(s1->got->data + offset, sym->st_value); +#endif +} + +/* Perform relocation to GOT or PLT entries */ +ST_FUNC void fill_got(TCCState *s1) +{ + Section *s; + ElfW_Rel *rel; + int i; + + for(i = 1; i < s1->nb_sections; i++) { + s = s1->sections[i]; + if (s->sh_type != SHT_RELX) + continue; + /* no need to handle got relocations */ + if (s->link != symtab_section) + continue; + for_each_elem(s, 0, rel, ElfW_Rel) { + switch (ELFW(R_TYPE) (rel->r_info)) { + case R_X86_64_GOT32: + case R_X86_64_GOTPCREL: + case R_X86_64_GOTPCRELX: + case R_X86_64_REX_GOTPCRELX: + case R_X86_64_PLT32: + fill_got_entry(s1, rel); + break; + } + } + } +} + +/* See put_got_entry for a description. This is the second stage + where GOT references to local defined symbols are rewritten. */ +static void fill_local_got_entries(TCCState *s1) +{ + ElfW_Rel *rel; + if (!s1->got->reloc) + return; + for_each_elem(s1->got->reloc, 0, rel, ElfW_Rel) { + if (ELFW(R_TYPE)(rel->r_info) == R_RELATIVE) { + int sym_index = ELFW(R_SYM) (rel->r_info); + ElfW(Sym) *sym = &((ElfW(Sym) *) symtab_section->data)[sym_index]; + struct sym_attr *attr = get_sym_attr(s1, sym_index, 0); + unsigned offset = attr->got_offset; + if (offset != rel->r_offset - s1->got->sh_addr) + tcc_error_noabort("fill_local_got_entries: huh?"); + rel->r_info = ELFW(R_INFO)(0, R_RELATIVE); +#if SHT_RELX == SHT_RELA + rel->r_addend = sym->st_value; +#else + /* All our REL architectures also happen to be 32bit LE. */ + write32le(s1->got->data + offset, sym->st_value); +#endif + } + } +} + +/* Bind symbols of executable: resolve undefined symbols from exported symbols + in shared libraries */ +static void bind_exe_dynsyms(TCCState *s1) +{ + const char *name; + int sym_index, index; + ElfW(Sym) *sym, *esym; + int type; + + /* Resolve undefined symbols from dynamic symbols. When there is a match: + - if STT_FUNC or STT_GNU_IFUNC symbol -> add it in PLT + - if STT_OBJECT symbol -> add it in .bss section with suitable reloc */ + for_each_elem(symtab_section, 1, sym, ElfW(Sym)) { + if (sym->st_shndx == SHN_UNDEF) { + name = (char *) symtab_section->link->data + sym->st_name; + sym_index = find_elf_sym(s1->dynsymtab_section, name); + if (sym_index) { + esym = &((ElfW(Sym) *)s1->dynsymtab_section->data)[sym_index]; + type = ELFW(ST_TYPE)(esym->st_info); + if ((type == STT_FUNC) || (type == STT_GNU_IFUNC)) { + /* Indirect functions shall have STT_FUNC type in executable + * dynsym section. Indeed, a dlsym call following a lazy + * resolution would pick the symbol value from the + * executable dynsym entry which would contain the address + * of the function wanted by the caller of dlsym instead of + * the address of the function that would return that + * address */ + int dynindex + = put_elf_sym(s1->dynsym, 0, esym->st_size, + ELFW(ST_INFO)(STB_GLOBAL,STT_FUNC), 0, 0, + name); + int index = sym - (ElfW(Sym) *) symtab_section->data; + get_sym_attr(s1, index, 1)->dyn_index = dynindex; + } else if (type == STT_OBJECT) { + unsigned long offset; + ElfW(Sym) *dynsym; + offset = bss_section->data_offset; + /* XXX: which alignment ? */ + offset = (offset + 16 - 1) & -16; + set_elf_sym (s1->symtab, offset, esym->st_size, + esym->st_info, 0, bss_section->sh_num, name); + index = put_elf_sym(s1->dynsym, offset, esym->st_size, + esym->st_info, 0, bss_section->sh_num, + name); + + /* Ensure R_COPY works for weak symbol aliases */ + if (ELFW(ST_BIND)(esym->st_info) == STB_WEAK) { + for_each_elem(s1->dynsymtab_section, 1, dynsym, ElfW(Sym)) { + if ((dynsym->st_value == esym->st_value) + && (ELFW(ST_BIND)(dynsym->st_info) == STB_GLOBAL)) { + char *dynname = (char *) s1->dynsymtab_section->link->data + + dynsym->st_name; + put_elf_sym(s1->dynsym, offset, dynsym->st_size, + dynsym->st_info, 0, + bss_section->sh_num, dynname); + break; + } + } + } + + put_elf_reloc(s1->dynsym, bss_section, + offset, R_COPY, index); + offset += esym->st_size; + bss_section->data_offset = offset; + } + } else { + /* STB_WEAK undefined symbols are accepted */ + /* XXX: _fp_hw seems to be part of the ABI, so we ignore it */ + if (ELFW(ST_BIND)(sym->st_info) == STB_WEAK || + !strcmp(name, "_fp_hw")) { + } else { + tcc_error_noabort("undefined symbol '%s'", name); + } + } + } + } +} + +/* Bind symbols of libraries: export all non local symbols of executable that + are referenced by shared libraries. The reason is that the dynamic loader + search symbol first in executable and then in libraries. Therefore a + reference to a symbol already defined by a library can still be resolved by + a symbol in the executable. With -rdynamic, export all defined symbols */ +static void bind_libs_dynsyms(TCCState *s1) +{ + const char *name; + int dynsym_index; + ElfW(Sym) *sym, *esym; + + for_each_elem(symtab_section, 1, sym, ElfW(Sym)) { + name = (char *)symtab_section->link->data + sym->st_name; + dynsym_index = find_elf_sym(s1->dynsymtab_section, name); + if (sym->st_shndx != SHN_UNDEF + && ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) { + if (dynsym_index || s1->rdynamic) + set_elf_sym(s1->dynsym, sym->st_value, sym->st_size, + sym->st_info, 0, sym->st_shndx, name); + } else if (dynsym_index) { + esym = (ElfW(Sym) *)s1->dynsymtab_section->data + dynsym_index; + if (esym->st_shndx == SHN_UNDEF) { + /* weak symbols can stay undefined */ + if (ELFW(ST_BIND)(esym->st_info) != STB_WEAK) + tcc_warning("undefined dynamic symbol '%s'", name); + } + } + } +} + +/* Export all non local symbols. This is used by shared libraries so that the + non local symbols they define can resolve a reference in another shared + library or in the executable. Correspondingly, it allows undefined local + symbols to be resolved by other shared libraries or by the executable. */ +static void export_global_syms(TCCState *s1) +{ + int dynindex, index; + const char *name; + ElfW(Sym) *sym; + for_each_elem(symtab_section, 1, sym, ElfW(Sym)) { + if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) { + name = (char *) symtab_section->link->data + sym->st_name; + dynindex = set_elf_sym(s1->dynsym, sym->st_value, sym->st_size, + sym->st_info, 0, sym->st_shndx, name); + index = sym - (ElfW(Sym) *) symtab_section->data; + get_sym_attr(s1, index, 1)->dyn_index = dynindex; + } + } +} + +/* decide if an unallocated section should be output. */ +static int set_sec_sizes(TCCState *s1) +{ + int i; + Section *s; + int textrel = 0; + int file_type = s1->output_type; + + /* Allocate strings for section names */ + for(i = 1; i < s1->nb_sections; i++) { + s = s1->sections[i]; + if (s->sh_type == SHT_RELX && !(s->sh_flags & SHF_ALLOC)) { + /* when generating a DLL, we include relocations but + we may patch them */ + if ((file_type & TCC_OUTPUT_DYN) + && (s1->sections[s->sh_info]->sh_flags & SHF_ALLOC)) { + int count = prepare_dynamic_rel(s1, s); + if (count) { + /* allocate the section */ + s->sh_flags |= SHF_ALLOC; + s->sh_size = count * sizeof(ElfW_Rel); + if (!(s1->sections[s->sh_info]->sh_flags & SHF_WRITE)) + textrel += count; + } + } + } else if ((s->sh_flags & SHF_ALLOC) +#ifdef TCC_TARGET_ARM + || s->sh_type == SHT_ARM_ATTRIBUTES +#endif + || s1->do_debug) { + s->sh_size = s->data_offset; + } + +#ifdef TCC_TARGET_ARM + /* XXX: Suppress stack unwinding section. */ + if (s->sh_type == SHT_ARM_EXIDX) { + s->sh_flags = 0; + s->sh_size = 0; + } +#endif + + } + return textrel; +} + +/* various data used under elf_output_file() */ +struct dyn_inf { + Section *dynamic; + Section *dynstr; + struct { + /* Info to be copied in dynamic section */ + unsigned long data_offset; + addr_t rel_addr; + addr_t rel_size; + }; + + ElfW(Phdr) *phdr; + int phnum; + Section *interp; + Section *note; + Section *gnu_hash; + + /* read only segment mapping for GNU_RELRO */ + Section _roinf, *roinf; +}; + +/* Decide the layout of sections loaded in memory. This must be done before + program headers are filled since they contain info about the layout. + We do the following ordering: interp, symbol tables, relocations, progbits, + nobits */ +static int sort_sections(TCCState *s1, int *sec_order, Section *interp) +{ + Section *s; + int i, j, k, f, f0, n; + int nb_sections = s1->nb_sections; + int *sec_cls = sec_order + nb_sections; + + for (i = 1; i < nb_sections; i++) { + s = s1->sections[i]; + if (s->sh_flags & SHF_ALLOC) { + j = 0x100; + if (s->sh_flags & SHF_WRITE) + j = 0x200; + if (s->sh_flags & SHF_TLS) + j += 0x200; + } else if (s->sh_name) { + j = 0x700; + } else { + j = 0x900; /* no sh_name: won't go to file */ + } + if (s->sh_type == SHT_SYMTAB || s->sh_type == SHT_DYNSYM) { + k = 0x10; + } else if (s->sh_type == SHT_STRTAB && strcmp(s->name, ".stabstr")) { + k = 0x11; + if (i == nb_sections - 1) /* ".shstrtab" assumed to remain last */ + k = 0xff; + } else if (s->sh_type == SHT_HASH || s->sh_type == SHT_GNU_HASH) { + k = 0x12; + } else if (s->sh_type == SHT_RELX) { + k = 0x20; + if (s1->plt && s == s1->plt->reloc) + k = 0x21; + } else if (s->sh_type == SHT_PREINIT_ARRAY) { + k = 0x41; + } else if (s->sh_type == SHT_INIT_ARRAY) { + k = 0x42; + } else if (s->sh_type == SHT_FINI_ARRAY) { + k = 0x43; +#ifdef CONFIG_TCC_BCHECK + } else if (s == bounds_section || s == lbounds_section) { + k = 0x44; +#endif + } else if (s == rodata_section || 0 == strcmp(s->name, ".data.rel.ro")) { + k = 0x45; + } else if (s->sh_type == SHT_DYNAMIC) { + k = 0x46; + } else if (s == s1->got) { + k = 0x47; /* .got as RELRO needs BIND_NOW in DT_FLAGS */ + } else { + k = 0x50; + if (s->sh_type == SHT_NOTE) + k = 0x60; + if (s->sh_flags & SHF_EXECINSTR) + k = 0x70; + if (s->sh_type == SHT_NOBITS) + k = 0x80; + if (s == interp) + k = 0x00; + } + k += j; + + for (n = i; n > 1 && k < (f = sec_cls[n - 1]); --n) + sec_cls[n] = f, sec_order[n] = sec_order[n - 1]; + sec_cls[n] = k, sec_order[n] = i; + } + sec_order[0] = 0; + + /* count PT_LOAD headers needed */ + n = f0 = 0; + for (i = 1; i < nb_sections; i++) { + s = s1->sections[sec_order[i]]; + k = sec_cls[i]; + f = 0; + if (k < 0x700) { + f = s->sh_flags & (SHF_ALLOC|SHF_WRITE|SHF_EXECINSTR|SHF_TLS); +#if TARGETOS_NetBSD + /* NetBSD only supports 2 PT_LOAD sections. + See: https://blog.netbsd.org/tnf/entry/the_first_report_on_lld */ + if ((f & SHF_WRITE) == 0) f |= SHF_EXECINSTR; +#else + if ((k & 0xfff0) == 0x240) /* RELRO sections */ + f |= 1<<4; +#endif + if (f != f0) /* start new header when flags changed or relro */ + f0 = f, ++n, f |= 1<<8; + } + sec_cls[i] = f; + //printf("ph %d sec %02d : %3X %3X %8.2X %04X %s\n", !!f * n, i, f, k, s->sh_type, s->sh_size, s->name); + } + return n; +} + +static ElfW(Phdr) *fill_phdr(ElfW(Phdr) *ph, int type, Section *s) +{ + if (s) { + ph->p_offset = s->sh_offset; + ph->p_vaddr = s->sh_addr; + ph->p_filesz = s->sh_size; + ph->p_align = s->sh_addralign; + } + ph->p_type = type; + ph->p_flags = PF_R; + ph->p_paddr = ph->p_vaddr; + ph->p_memsz = ph->p_filesz; + return ph; +} + +/* Assign sections to segments and decide how are sections laid out when loaded + in memory. This function also fills corresponding program headers. */ +static int layout_sections(TCCState *s1, int *sec_order, struct dyn_inf *d) +{ + Section *s; + addr_t addr, tmp, align, s_align, base; + ElfW(Phdr) *ph = NULL; + int i, f, n, phnum, phfill; + int file_offset; + + /* compute number of program headers */ + phnum = sort_sections(s1, sec_order, d->interp); + phfill = 0; /* set to 1 to have dll's with a PT_PHDR */ + if (d->interp) + phfill = 2; + phnum += phfill; + if (d->note) + ++phnum; + if (d->dynamic) + ++phnum; + if (d->roinf) + ++phnum; + d->phnum = phnum; + d->phdr = tcc_mallocz(phnum * sizeof(ElfW(Phdr))); + + file_offset = 0; + if (s1->output_format == TCC_OUTPUT_FORMAT_ELF) + file_offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr)); + + s_align = ELF_PAGE_SIZE; + if (s1->section_align) + s_align = s1->section_align; + + addr = ELF_START_ADDR; + if (s1->output_type & TCC_OUTPUT_DYN) + addr = 0; + + if (s1->has_text_addr) { + addr = s1->text_addr; + if (0) { + int a_offset, p_offset; + /* we ensure that (addr % ELF_PAGE_SIZE) == file_offset % + ELF_PAGE_SIZE */ + a_offset = (int) (addr & (s_align - 1)); + p_offset = file_offset & (s_align - 1); + if (a_offset < p_offset) + a_offset += s_align; + file_offset += (a_offset - p_offset); + } + } + base = addr; + /* compute address after headers */ + addr = addr + (file_offset & (s_align - 1)); + + n = 0; + for(i = 1; i < s1->nb_sections; i++) { + s = s1->sections[sec_order[i]]; + f = sec_order[i + s1->nb_sections]; + align = s->sh_addralign - 1; + + if (f == 0) { /* no alloc */ + file_offset = (file_offset + align) & ~align; + s->sh_offset = file_offset; + if (s->sh_type != SHT_NOBITS) + file_offset += s->sh_size; + continue; + } + + if ((f & 1<<8) && n) { + /* different rwx section flags */ + if (s1->output_format == TCC_OUTPUT_FORMAT_ELF) { + /* if in the middle of a page, w e duplicate the page in + memory so that one copy is RX and the other is RW */ + if ((addr & (s_align - 1)) != 0) + addr += s_align; + } else { + align = s_align - 1; + } + } + + tmp = addr; + addr = (addr + align) & ~align; + file_offset += (int)(addr - tmp); + s->sh_offset = file_offset; + s->sh_addr = addr; + + if (f & 1<<8) { + /* set new program header */ + ph = &d->phdr[phfill + n]; + ph->p_type = PT_LOAD; + ph->p_align = s_align; + ph->p_flags = PF_R; + if (f & SHF_WRITE) + ph->p_flags |= PF_W; + if (f & SHF_EXECINSTR) + ph->p_flags |= PF_X; + if (f & SHF_TLS) { + ph->p_type = PT_TLS; + ph->p_align = align + 1; + } + + ph->p_offset = file_offset; + ph->p_vaddr = addr; + if (n == 0) { + /* Make the first PT_LOAD segment include the program + headers itself (and the ELF header as well), it'll + come out with same memory use but will make various + tools like binutils strip work better. */ + ph->p_offset = 0; + ph->p_vaddr = base; + } + ph->p_paddr = ph->p_vaddr; + ++n; + } + + if (f & 1<<4) { + Section *roinf = &d->_roinf; + if (roinf->sh_size == 0) { + roinf->sh_offset = s->sh_offset; + roinf->sh_addr = s->sh_addr; + roinf->sh_addralign = 1; + } + roinf->sh_size = (addr - roinf->sh_addr) + s->sh_size; + } + + addr += s->sh_size; + if (s->sh_type != SHT_NOBITS) + file_offset += s->sh_size; + + ph->p_filesz = file_offset - ph->p_offset; + ph->p_memsz = addr - ph->p_vaddr; + } + + /* Fill other headers */ + if (d->note) + fill_phdr(++ph, PT_NOTE, d->note); + if (d->dynamic) + fill_phdr(++ph, PT_DYNAMIC, d->dynamic)->p_flags |= PF_W; + if (d->roinf) + fill_phdr(++ph, PT_GNU_RELRO, d->roinf)->p_flags |= PF_W; + if (d->interp) + fill_phdr(&d->phdr[1], PT_INTERP, d->interp); + if (phfill) { + ph = &d->phdr[0]; + ph->p_offset = sizeof(ElfW(Ehdr)); + ph->p_vaddr = base + ph->p_offset; + ph->p_filesz = phnum * sizeof(ElfW(Phdr)); + ph->p_align = 4; + fill_phdr(ph, PT_PHDR, NULL); + } + return file_offset; +} + +/* put dynamic tag */ +static void put_dt(Section *dynamic, int dt, addr_t val) +{ + ElfW(Dyn) *dyn; + dyn = section_ptr_add(dynamic, sizeof(ElfW(Dyn))); + dyn->d_tag = dt; + dyn->d_un.d_val = val; +} + +/* Fill the dynamic section with tags describing the address and size of + sections */ +static void fill_dynamic(TCCState *s1, struct dyn_inf *dyninf) +{ + Section *dynamic = dyninf->dynamic; + Section *s; + + /* put dynamic section entries */ + put_dt(dynamic, DT_HASH, s1->dynsym->hash->sh_addr); + put_dt(dynamic, DT_GNU_HASH, dyninf->gnu_hash->sh_addr); + put_dt(dynamic, DT_STRTAB, dyninf->dynstr->sh_addr); + put_dt(dynamic, DT_SYMTAB, s1->dynsym->sh_addr); + put_dt(dynamic, DT_STRSZ, dyninf->dynstr->data_offset); + put_dt(dynamic, DT_SYMENT, sizeof(ElfW(Sym))); +#if PTR_SIZE == 8 + put_dt(dynamic, DT_RELA, dyninf->rel_addr); + put_dt(dynamic, DT_RELASZ, dyninf->rel_size); + put_dt(dynamic, DT_RELAENT, sizeof(ElfW_Rel)); + if (s1->plt && s1->plt->reloc) { + put_dt(dynamic, DT_PLTGOT, s1->got->sh_addr); + put_dt(dynamic, DT_PLTRELSZ, s1->plt->reloc->data_offset); + put_dt(dynamic, DT_JMPREL, s1->plt->reloc->sh_addr); + put_dt(dynamic, DT_PLTREL, DT_RELA); + } + put_dt(dynamic, DT_RELACOUNT, 0); +#else + put_dt(dynamic, DT_REL, dyninf->rel_addr); + put_dt(dynamic, DT_RELSZ, dyninf->rel_size); + put_dt(dynamic, DT_RELENT, sizeof(ElfW_Rel)); + if (s1->plt && s1->plt->reloc) { + put_dt(dynamic, DT_PLTGOT, s1->got->sh_addr); + put_dt(dynamic, DT_PLTRELSZ, s1->plt->reloc->data_offset); + put_dt(dynamic, DT_JMPREL, s1->plt->reloc->sh_addr); + put_dt(dynamic, DT_PLTREL, DT_REL); + } + put_dt(dynamic, DT_RELCOUNT, 0); +#endif + if (versym_section && verneed_section) { + /* The dynamic linker can not handle VERSYM without VERNEED */ + put_dt(dynamic, DT_VERSYM, versym_section->sh_addr); + put_dt(dynamic, DT_VERNEED, verneed_section->sh_addr); + put_dt(dynamic, DT_VERNEEDNUM, dt_verneednum); + } + s = have_section(s1, ".preinit_array"); + if (s && s->data_offset) { + put_dt(dynamic, DT_PREINIT_ARRAY, s->sh_addr); + put_dt(dynamic, DT_PREINIT_ARRAYSZ, s->data_offset); + } + s = have_section(s1, ".init_array"); + if (s && s->data_offset) { + put_dt(dynamic, DT_INIT_ARRAY, s->sh_addr); + put_dt(dynamic, DT_INIT_ARRAYSZ, s->data_offset); + } + s = have_section(s1, ".fini_array"); + if (s && s->data_offset) { + put_dt(dynamic, DT_FINI_ARRAY, s->sh_addr); + put_dt(dynamic, DT_FINI_ARRAYSZ, s->data_offset); + } + s = have_section(s1, ".init"); + if (s && s->data_offset) { + put_dt(dynamic, DT_INIT, s->sh_addr); + } + s = have_section(s1, ".fini"); + if (s && s->data_offset) { + put_dt(dynamic, DT_FINI, s->sh_addr); + } + if (s1->do_debug) + put_dt(dynamic, DT_DEBUG, 0); + put_dt(dynamic, DT_NULL, 0); +} + +/* Remove gaps between RELX sections. + These gaps are a result of final_sections_reloc. Here some relocs are removed. + The gaps are then filled with 0 in tcc_output_elf. The 0 is intepreted as + R_...NONE reloc. This does work on most targets but on OpenBSD/arm64 this + is illegal. OpenBSD/arm64 does not support R_...NONE reloc. */ +static void update_reloc_sections(TCCState *s1, struct dyn_inf *dyninf) +{ + int i; + unsigned long file_offset = 0; + Section *s; + Section *relocplt = s1->plt ? s1->plt->reloc : NULL; + + /* dynamic relocation table information, for .dynamic section */ + dyninf->rel_addr = dyninf->rel_size = 0; + + for(i = 1; i < s1->nb_sections; i++) { + s = s1->sections[i]; + if (s->sh_type == SHT_RELX && s != relocplt) { + if (dyninf->rel_size == 0) { + dyninf->rel_addr = s->sh_addr; + file_offset = s->sh_offset; + } + else { + s->sh_addr = dyninf->rel_addr + dyninf->rel_size; + s->sh_offset = file_offset + dyninf->rel_size; + } + dyninf->rel_size += s->sh_size; + } + } +} + +static int tidy_section_headers(TCCState *s1, int *sec_order); +#endif /* ndef ELF_OBJ_ONLY */ + +/* Create an ELF file on disk. + This function handle ELF specific layout requirements */ +static int tcc_output_elf(TCCState *s1, FILE *f, int phnum, ElfW(Phdr) *phdr, + int file_offset, int *sec_order) +{ + int i, shnum, offset, size, file_type; + Section *s; + ElfW(Ehdr) ehdr; + ElfW(Shdr) shdr, *sh; + + file_type = s1->output_type; + shnum = s1->nb_sections; + + memset(&ehdr, 0, sizeof(ehdr)); + + if (phnum > 0) { + ehdr.e_phentsize = sizeof(ElfW(Phdr)); + ehdr.e_phnum = phnum; + ehdr.e_phoff = sizeof(ElfW(Ehdr)); +#ifndef ELF_OBJ_ONLY + shnum = tidy_section_headers(s1, sec_order); +#endif + } + + /* align to 4 */ + file_offset = (file_offset + 3) & -4; + + /* fill header */ + ehdr.e_ident[0] = ELFMAG0; + ehdr.e_ident[1] = ELFMAG1; + ehdr.e_ident[2] = ELFMAG2; + ehdr.e_ident[3] = ELFMAG3; + ehdr.e_ident[4] = ELFCLASSW; + ehdr.e_ident[5] = ELFDATA2LSB; + ehdr.e_ident[6] = EV_CURRENT; + +#if TARGETOS_FreeBSD || TARGETOS_FreeBSD_kernel + ehdr.e_ident[EI_OSABI] = ELFOSABI_FREEBSD; +#elif defined TCC_TARGET_ARM && defined TCC_ARM_EABI + ehdr.e_flags = EF_ARM_EABI_VER5; + ehdr.e_flags |= s1->float_abi == ARM_HARD_FLOAT + ? EF_ARM_VFP_FLOAT : EF_ARM_SOFT_FLOAT; +#elif defined TCC_TARGET_ARM + ehdr.e_ident[EI_OSABI] = ELFOSABI_ARM; +#elif defined TCC_TARGET_RISCV64 + ehdr.e_flags = EF_RISCV_FLOAT_ABI_DOUBLE; +#endif + + if (file_type == TCC_OUTPUT_OBJ) { + ehdr.e_type = ET_REL; + } else { + if (file_type & TCC_OUTPUT_DYN) + ehdr.e_type = ET_DYN; + else + ehdr.e_type = ET_EXEC; + if (s1->elf_entryname) + ehdr.e_entry = get_sym_addr(s1, s1->elf_entryname, 1, 0); + else + ehdr.e_entry = get_sym_addr(s1, "_start", !!(file_type & TCC_OUTPUT_EXE), 0); + if (ehdr.e_entry == (addr_t)-1) + ehdr.e_entry = text_section->sh_addr; + if (s1->nb_errors) + return -1; + } + + ehdr.e_machine = EM_TCC_TARGET; + ehdr.e_version = EV_CURRENT; + ehdr.e_shoff = file_offset; + ehdr.e_ehsize = sizeof(ElfW(Ehdr)); + ehdr.e_shentsize = sizeof(ElfW(Shdr)); + ehdr.e_shnum = shnum; + ehdr.e_shstrndx = shnum - 1; + + fwrite(&ehdr, 1, sizeof(ElfW(Ehdr)), f); + if (phdr) + fwrite(phdr, 1, phnum * sizeof(ElfW(Phdr)), f); + offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr)); + + sort_syms(s1, symtab_section); + + for(i = 1; i < shnum; i++) { + s = s1->sections[sec_order ? sec_order[i] : i]; + if (s->sh_type != SHT_NOBITS) { + while (offset < s->sh_offset) { + fputc(0, f); + offset++; + } + size = s->sh_size; + if (size) + fwrite(s->data, 1, size, f); + offset += size; + } + } + + /* output section headers */ + while (offset < ehdr.e_shoff) { + fputc(0, f); + offset++; + } + + for(i = 0; i < shnum; i++) { + sh = &shdr; + memset(sh, 0, sizeof(ElfW(Shdr))); + s = s1->sections[i]; + if (s) { + sh->sh_name = s->sh_name; + sh->sh_type = s->sh_type; + sh->sh_flags = s->sh_flags; + sh->sh_entsize = s->sh_entsize; + sh->sh_info = s->sh_info; + if (s->link) + sh->sh_link = s->link->sh_num; + sh->sh_addralign = s->sh_addralign; + sh->sh_addr = s->sh_addr; + sh->sh_offset = s->sh_offset; + sh->sh_size = s->sh_size; + } + fwrite(sh, 1, sizeof(ElfW(Shdr)), f); + } + return 0; +} + +static int tcc_output_binary(TCCState *s1, FILE *f, + const int *sec_order) +{ + Section *s; + int i, offset, size; + + offset = 0; + for(i=1;i<s1->nb_sections;i++) { + s = s1->sections[sec_order[i]]; + if (s->sh_type != SHT_NOBITS && + (s->sh_flags & SHF_ALLOC)) { + while (offset < s->sh_offset) { + fputc(0, f); + offset++; + } + size = s->sh_size; + fwrite(s->data, 1, size, f); + offset += size; + } + } + return 0; +} + +/* Write an elf, coff or "binary" file */ +static int tcc_write_elf_file(TCCState *s1, const char *filename, int phnum, + ElfW(Phdr) *phdr, int file_offset, int *sec_order) +{ + int fd, mode, file_type, ret; + FILE *f; + + file_type = s1->output_type; + if (file_type == TCC_OUTPUT_OBJ) + mode = 0666; + else + mode = 0777; + unlink(filename); + fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, mode); + if (fd < 0 || (f = fdopen(fd, "wb")) == NULL) + return tcc_error_noabort("could not write '%s: %s'", filename, strerror(errno)); + if (s1->verbose) + printf("<- %s\n", filename); +#ifdef TCC_TARGET_COFF + if (s1->output_format == TCC_OUTPUT_FORMAT_COFF) + tcc_output_coff(s1, f); + else +#endif + if (s1->output_format == TCC_OUTPUT_FORMAT_ELF) + ret = tcc_output_elf(s1, f, phnum, phdr, file_offset, sec_order); + else + ret = tcc_output_binary(s1, f, sec_order); + fclose(f); + + return ret; +} + +#ifndef ELF_OBJ_ONLY +/* Sort section headers by assigned sh_addr, remove sections + that we aren't going to output. */ +static int tidy_section_headers(TCCState *s1, int *sec_order) +{ + int i, nnew, l, *backmap; + Section **snew, *s; + ElfW(Sym) *sym; + + snew = tcc_malloc(s1->nb_sections * sizeof(snew[0])); + backmap = tcc_malloc(s1->nb_sections * sizeof(backmap[0])); + for (i = 0, nnew = 0, l = s1->nb_sections; i < s1->nb_sections; i++) { + s = s1->sections[sec_order[i]]; + if (!i || s->sh_name) { + backmap[sec_order[i]] = nnew; + snew[nnew] = s; + ++nnew; + } else { + backmap[sec_order[i]] = 0; + snew[--l] = s; + } + } + for (i = 0; i < nnew; i++) { + s = snew[i]; + if (s) { + s->sh_num = i; + if (s->sh_type == SHT_RELX) + s->sh_info = backmap[s->sh_info]; + } + } + + for_each_elem(symtab_section, 1, sym, ElfW(Sym)) + if (sym->st_shndx != SHN_UNDEF && sym->st_shndx < SHN_LORESERVE) + sym->st_shndx = backmap[sym->st_shndx]; + if ( !s1->static_link ) { + for_each_elem(s1->dynsym, 1, sym, ElfW(Sym)) + if (sym->st_shndx != SHN_UNDEF && sym->st_shndx < SHN_LORESERVE) + sym->st_shndx = backmap[sym->st_shndx]; + } + for (i = 0; i < s1->nb_sections; i++) + sec_order[i] = i; + tcc_free(s1->sections); + s1->sections = snew; + tcc_free(backmap); + return nnew; +} + +#ifdef TCC_TARGET_ARM +static void create_arm_attribute_section(TCCState *s1) +{ + // Needed for DLL support. + static const unsigned char arm_attr[] = { + 0x41, // 'A' + 0x2c, 0x00, 0x00, 0x00, // size 0x2c + 'a', 'e', 'a', 'b', 'i', 0x00, // "aeabi" + 0x01, 0x22, 0x00, 0x00, 0x00, // 'File Attributes', size 0x22 + 0x05, 0x36, 0x00, // 'CPU_name', "6" + 0x06, 0x06, // 'CPU_arch', 'v6' + 0x08, 0x01, // 'ARM_ISA_use', 'Yes' + 0x09, 0x01, // 'THUMB_ISA_use', 'Thumb-1' + 0x0a, 0x02, // 'FP_arch', 'VFPv2' + 0x12, 0x04, // 'ABI_PCS_wchar_t', 4 + 0x14, 0x01, // 'ABI_FP_denormal', 'Needed' + 0x15, 0x01, // 'ABI_FP_exceptions', 'Needed' + 0x17, 0x03, // 'ABI_FP_number_model', 'IEEE 754' + 0x18, 0x01, // 'ABI_align_needed', '8-byte' + 0x19, 0x01, // 'ABI_align_preserved', '8-byte, except leaf SP' + 0x1a, 0x02, // 'ABI_enum_size', 'int' + 0x1c, 0x01, // 'ABI_VFP_args', 'VFP registers' + 0x22, 0x01 // 'CPU_unaligned_access', 'v6' + }; + Section *attr = new_section(s1, ".ARM.attributes", SHT_ARM_ATTRIBUTES, 0); + unsigned char *ptr = section_ptr_add(attr, sizeof(arm_attr)); + attr->sh_addralign = 1; + memcpy(ptr, arm_attr, sizeof(arm_attr)); + if (s1->float_abi != ARM_HARD_FLOAT) { + ptr[26] = 0x00; // 'FP_arch', 'No' + ptr[41] = 0x1e; // 'ABI_optimization_goals' + ptr[42] = 0x06; // 'Aggressive Debug' + } +} +#endif + +#if TARGETOS_OpenBSD || TARGETOS_NetBSD +static Section *create_bsd_note_section(TCCState *s1, + const char *name, + const char *value) +{ + Section *s = find_section (s1, name); + + if (s->data_offset == 0) { + char *ptr = section_ptr_add(s, sizeof(ElfW(Nhdr)) + 8 + 4); + ElfW(Nhdr) *note = (ElfW(Nhdr) *) ptr; + + s->sh_type = SHT_NOTE; + note->n_namesz = 8; + note->n_descsz = 4; + note->n_type = ELF_NOTE_OS_GNU; + strcpy (ptr + sizeof(ElfW(Nhdr)), value); + } + return s; +} +#endif + +static void alloc_sec_names(TCCState *s1, int is_obj); + +/* Output an elf, coff or binary file */ +/* XXX: suppress unneeded sections */ +static int elf_output_file(TCCState *s1, const char *filename) +{ + int i, ret, file_type, file_offset, *sec_order; + struct dyn_inf dyninf = {0}; + Section *interp, *dynstr, *dynamic; + int textrel, got_sym, dt_flags_1; + + file_type = s1->output_type; + s1->nb_errors = 0; + ret = -1; + interp = dynstr = dynamic = NULL; + sec_order = NULL; + dyninf.roinf = &dyninf._roinf; + +#ifdef TCC_TARGET_ARM + create_arm_attribute_section (s1); +#endif + +#if TARGETOS_OpenBSD + dyninf.note = create_bsd_note_section (s1, ".note.openbsd.ident", "OpenBSD"); +#endif + +#if TARGETOS_NetBSD + dyninf.note = create_bsd_note_section (s1, ".note.netbsd.ident", "NetBSD"); +#endif + +#if TARGETOS_FreeBSD || TARGETOS_NetBSD + dyninf.roinf = NULL; +#endif + /* if linking, also link in runtime libraries (libc, libgcc, etc.) */ + tcc_add_runtime(s1); + resolve_common_syms(s1); + + if (!s1->static_link) { + if (file_type & TCC_OUTPUT_EXE) { + char *ptr; + /* allow override the dynamic loader */ + const char *elfint = getenv("LD_SO"); + if (elfint == NULL) + elfint = DEFAULT_ELFINTERP(s1); + /* add interpreter section only if executable */ + interp = new_section(s1, ".interp", SHT_PROGBITS, SHF_ALLOC); + interp->sh_addralign = 1; + ptr = section_ptr_add(interp, 1 + strlen(elfint)); + strcpy(ptr, elfint); + dyninf.interp = interp; + } + + /* add dynamic symbol table */ + s1->dynsym = new_symtab(s1, ".dynsym", SHT_DYNSYM, SHF_ALLOC, + ".dynstr", + ".hash", SHF_ALLOC); + /* Number of local symbols (readelf complains if not set) */ + s1->dynsym->sh_info = 1; + dynstr = s1->dynsym->link; + /* add dynamic section */ + dynamic = new_section(s1, ".dynamic", SHT_DYNAMIC, + SHF_ALLOC | SHF_WRITE); + dynamic->link = dynstr; + dynamic->sh_entsize = sizeof(ElfW(Dyn)); + + got_sym = build_got(s1); + if (file_type == TCC_OUTPUT_EXE) { + bind_exe_dynsyms(s1); + if (s1->nb_errors) + goto the_end; + } + build_got_entries(s1, got_sym); + if (file_type & TCC_OUTPUT_EXE) { + bind_libs_dynsyms(s1); + } else { + /* shared library case: simply export all global symbols */ + export_global_syms(s1); + } + dyninf.gnu_hash = create_gnu_hash(s1); + } else { + build_got_entries(s1, 0); + } + version_add (s1); + + textrel = set_sec_sizes(s1); + alloc_sec_names(s1, 0); + + if (!s1->static_link) { + /* add a list of needed dlls */ + for(i = 0; i < s1->nb_loaded_dlls; i++) { + DLLReference *dllref = s1->loaded_dlls[i]; + if (dllref->level == 0) + put_dt(dynamic, DT_NEEDED, put_elf_str(dynstr, dllref->name)); + } + + if (s1->rpath) + put_dt(dynamic, s1->enable_new_dtags ? DT_RUNPATH : DT_RPATH, + put_elf_str(dynstr, s1->rpath)); + + dt_flags_1 = DF_1_NOW; + if (file_type & TCC_OUTPUT_DYN) { + if (s1->soname) + put_dt(dynamic, DT_SONAME, put_elf_str(dynstr, s1->soname)); + /* XXX: currently, since we do not handle PIC code, we + must relocate the readonly segments */ + if (textrel) + put_dt(dynamic, DT_TEXTREL, 0); + if (file_type & TCC_OUTPUT_EXE) + dt_flags_1 = DF_1_NOW | DF_1_PIE; + } + put_dt(dynamic, DT_FLAGS, DF_BIND_NOW); + put_dt(dynamic, DT_FLAGS_1, dt_flags_1); + if (s1->symbolic) + put_dt(dynamic, DT_SYMBOLIC, 0); + + dyninf.dynamic = dynamic; + dyninf.dynstr = dynstr; + /* remember offset and reserve space for 2nd call below */ + dyninf.data_offset = dynamic->data_offset; + fill_dynamic(s1, &dyninf); + dynamic->sh_size = dynamic->data_offset; + dynstr->sh_size = dynstr->data_offset; + } + + /* this array is used to reorder sections in the output file */ + sec_order = tcc_malloc(sizeof(int) * 2 * s1->nb_sections); + /* compute section to program header mapping */ + file_offset = layout_sections(s1, sec_order, &dyninf); + + if (dynamic) { + /* put in GOT the dynamic section address and relocate PLT */ + write32le(s1->got->data, dynamic->sh_addr); + if (file_type == TCC_OUTPUT_EXE + || (RELOCATE_DLLPLT && (file_type & TCC_OUTPUT_DYN))) + relocate_plt(s1); + /* relocate symbols in .dynsym now that final addresses are known */ + relocate_syms(s1, s1->dynsym, 2); + } + + /* if building executable or DLL, then relocate each section + except the GOT which is already relocated */ + relocate_syms(s1, s1->symtab, 0); + if (s1->nb_errors != 0) + goto the_end; + relocate_sections(s1); + if (dynamic) { + update_reloc_sections (s1, &dyninf); + dynamic->data_offset = dyninf.data_offset; + fill_dynamic(s1, &dyninf); + } + /* Perform relocation to GOT or PLT entries */ + if (file_type == TCC_OUTPUT_EXE && s1->static_link) + fill_got(s1); + else if (s1->got) + fill_local_got_entries(s1); + + if (dyninf.gnu_hash) + update_gnu_hash(s1, dyninf.gnu_hash); + + /* Create the ELF file with name 'filename' */ + ret = tcc_write_elf_file(s1, filename, dyninf.phnum, dyninf.phdr, file_offset, sec_order); + the_end: + tcc_free(sec_order); + tcc_free(dyninf.phdr); + return ret; +} +#endif /* ndef ELF_OBJ_ONLY */ + +/* Allocate strings for section names */ +static void alloc_sec_names(TCCState *s1, int is_obj) +{ + int i; + Section *s, *strsec; + + strsec = new_section(s1, ".shstrtab", SHT_STRTAB, 0); + put_elf_str(strsec, ""); + for(i = 1; i < s1->nb_sections; i++) { + s = s1->sections[i]; + if (is_obj) + s->sh_size = s->data_offset; + if (s == strsec || s->sh_size || (s->sh_flags & SHF_ALLOC)) + s->sh_name = put_elf_str(strsec, s->name); + } + strsec->sh_size = strsec->data_offset; +} + +/* Output an elf .o file */ +static int elf_output_obj(TCCState *s1, const char *filename) +{ + Section *s; + int i, ret, file_offset; + s1->nb_errors = 0; + /* Allocate strings for section names */ + alloc_sec_names(s1, 1); + file_offset = sizeof (ElfW(Ehdr)); + for(i = 1; i < s1->nb_sections; i++) { + s = s1->sections[i]; + file_offset = (file_offset + 15) & -16; + s->sh_offset = file_offset; + if (s->sh_type != SHT_NOBITS) + file_offset += s->sh_size; + } + /* Create the ELF file with name 'filename' */ + ret = tcc_write_elf_file(s1, filename, 0, NULL, file_offset, NULL); + return ret; +} + +LIBTCCAPI int tcc_output_file(TCCState *s, const char *filename) +{ + if (s->test_coverage) + tcc_tcov_add_file(s, filename); + if (s->output_type == TCC_OUTPUT_OBJ) + return elf_output_obj(s, filename); +#ifdef TCC_TARGET_PE + return pe_output_file(s, filename); +#elif TCC_TARGET_MACHO + return macho_output_file(s, filename); +#else + return elf_output_file(s, filename); +#endif +} + +ST_FUNC ssize_t full_read(int fd, void *buf, size_t count) { + char *cbuf = buf; + size_t rnum = 0; + while (1) { + ssize_t num = read(fd, cbuf, count-rnum); + if (num < 0) return num; + if (num == 0) return rnum; + rnum += num; + cbuf += num; + } +} + +ST_FUNC void *load_data(int fd, unsigned long file_offset, unsigned long size) +{ + void *data; + + data = tcc_malloc(size); + lseek(fd, file_offset, SEEK_SET); + full_read(fd, data, size); + return data; +} + +typedef struct SectionMergeInfo { + Section *s; /* corresponding existing section */ + unsigned long offset; /* offset of the new section in the existing section */ + uint8_t new_section; /* true if section 's' was added */ + uint8_t link_once; /* true if link once section */ +} SectionMergeInfo; + +ST_FUNC int tcc_object_type(int fd, ElfW(Ehdr) *h) +{ + int size = full_read(fd, h, sizeof *h); + if (size == sizeof *h && 0 == memcmp(h, ELFMAG, 4)) { + if (h->e_type == ET_REL) + return AFF_BINTYPE_REL; + if (h->e_type == ET_DYN) + return AFF_BINTYPE_DYN; + } else if (size >= 8) { + if (0 == memcmp(h, ARMAG, 8)) + return AFF_BINTYPE_AR; +#ifdef TCC_TARGET_COFF + if (((struct filehdr*)h)->f_magic == COFF_C67_MAGIC) + return AFF_BINTYPE_C67; +#endif + } + return 0; +} + +/* load an object file and merge it with current files */ +/* XXX: handle correctly stab (debug) info */ +ST_FUNC int tcc_load_object_file(TCCState *s1, + int fd, unsigned long file_offset) +{ + ElfW(Ehdr) ehdr; + ElfW(Shdr) *shdr, *sh; + unsigned long size, offset, offseti; + int i, j, nb_syms, sym_index, ret, seencompressed; + char *strsec, *strtab; + int stab_index, stabstr_index; + int *old_to_new_syms; + char *sh_name, *name; + SectionMergeInfo *sm_table, *sm; + ElfW(Sym) *sym, *symtab; + ElfW_Rel *rel; + Section *s; + + lseek(fd, file_offset, SEEK_SET); + if (tcc_object_type(fd, &ehdr) != AFF_BINTYPE_REL) + goto invalid; + /* test CPU specific stuff */ + if (ehdr.e_ident[5] != ELFDATA2LSB || + ehdr.e_machine != EM_TCC_TARGET) { +invalid: + return tcc_error_noabort("invalid object file"); + } + /* read sections */ + shdr = load_data(fd, file_offset + ehdr.e_shoff, + sizeof(ElfW(Shdr)) * ehdr.e_shnum); + sm_table = tcc_mallocz(sizeof(SectionMergeInfo) * ehdr.e_shnum); + + /* load section names */ + sh = &shdr[ehdr.e_shstrndx]; + strsec = load_data(fd, file_offset + sh->sh_offset, sh->sh_size); + + /* load symtab and strtab */ + old_to_new_syms = NULL; + symtab = NULL; + strtab = NULL; + nb_syms = 0; + seencompressed = 0; + stab_index = stabstr_index = 0; + ret = -1; + + for(i = 1; i < ehdr.e_shnum; i++) { + sh = &shdr[i]; + if (sh->sh_type == SHT_SYMTAB) { + if (symtab) { + tcc_error_noabort("object must contain only one symtab"); + goto the_end; + } + nb_syms = sh->sh_size / sizeof(ElfW(Sym)); + symtab = load_data(fd, file_offset + sh->sh_offset, sh->sh_size); + sm_table[i].s = symtab_section; + + /* now load strtab */ + sh = &shdr[sh->sh_link]; + strtab = load_data(fd, file_offset + sh->sh_offset, sh->sh_size); + } + if (sh->sh_flags & SHF_COMPRESSED) + seencompressed = 1; + } + + /* now examine each section and try to merge its content with the + ones in memory */ + for(i = 1; i < ehdr.e_shnum; i++) { + /* no need to examine section name strtab */ + if (i == ehdr.e_shstrndx) + continue; + sh = &shdr[i]; + if (sh->sh_type == SHT_RELX) + sh = &shdr[sh->sh_info]; + /* ignore sections types we do not handle (plus relocs to those) */ + if (sh->sh_type != SHT_PROGBITS && +#ifdef TCC_ARM_EABI + sh->sh_type != SHT_ARM_EXIDX && +#endif +#if TARGETOS_OpenBSD || TARGETOS_FreeBSD || TARGETOS_NetBSD + sh->sh_type != SHT_X86_64_UNWIND && +#endif + sh->sh_type != SHT_NOTE && + sh->sh_type != SHT_NOBITS && + sh->sh_type != SHT_PREINIT_ARRAY && + sh->sh_type != SHT_INIT_ARRAY && + sh->sh_type != SHT_FINI_ARRAY && + strcmp(strsec + sh->sh_name, ".stabstr") + ) + continue; + if (seencompressed && 0 == strncmp(strsec + sh->sh_name, ".debug_", 7)) + continue; + + sh = &shdr[i]; + sh_name = strsec + sh->sh_name; + if (sh->sh_addralign < 1) + sh->sh_addralign = 1; + /* find corresponding section, if any */ + for(j = 1; j < s1->nb_sections;j++) { + s = s1->sections[j]; + if (!strcmp(s->name, sh_name)) { + if (!strncmp(sh_name, ".gnu.linkonce", + sizeof(".gnu.linkonce") - 1)) { + /* if a 'linkonce' section is already present, we + do not add it again. It is a little tricky as + symbols can still be defined in + it. */ + sm_table[i].link_once = 1; + goto next; + } + if (stab_section) { + if (s == stab_section) + stab_index = i; + if (s == stab_section->link) + stabstr_index = i; + } + goto found; + } + } + /* not found: create new section */ + s = new_section(s1, sh_name, sh->sh_type, sh->sh_flags & ~SHF_GROUP); + /* take as much info as possible from the section. sh_link and + sh_info will be updated later */ + s->sh_addralign = sh->sh_addralign; + s->sh_entsize = sh->sh_entsize; + sm_table[i].new_section = 1; + found: + if (sh->sh_type != s->sh_type +#if TARGETOS_OpenBSD || TARGETOS_FreeBSD || TARGETOS_NetBSD + && strcmp (s->name, ".eh_frame") +#endif + ) { + tcc_error_noabort("invalid section type"); + goto the_end; + } + /* align start of section */ + s->data_offset += -s->data_offset & (sh->sh_addralign - 1); + if (sh->sh_addralign > s->sh_addralign) + s->sh_addralign = sh->sh_addralign; + sm_table[i].offset = s->data_offset; + sm_table[i].s = s; + /* concatenate sections */ + size = sh->sh_size; + if (sh->sh_type != SHT_NOBITS) { + unsigned char *ptr; + lseek(fd, file_offset + sh->sh_offset, SEEK_SET); + ptr = section_ptr_add(s, size); + full_read(fd, ptr, size); + } else { + s->data_offset += size; + } + next: ; + } + + /* gr relocate stab strings */ + if (stab_index && stabstr_index) { + Stab_Sym *a, *b; + unsigned o; + s = sm_table[stab_index].s; + a = (Stab_Sym *)(s->data + sm_table[stab_index].offset); + b = (Stab_Sym *)(s->data + s->data_offset); + o = sm_table[stabstr_index].offset; + while (a < b) { + if (a->n_strx) + a->n_strx += o; + a++; + } + } + + /* second short pass to update sh_link and sh_info fields of new + sections */ + for(i = 1; i < ehdr.e_shnum; i++) { + s = sm_table[i].s; + if (!s || !sm_table[i].new_section) + continue; + sh = &shdr[i]; + if (sh->sh_link > 0) + s->link = sm_table[sh->sh_link].s; + if (sh->sh_type == SHT_RELX) { + s->sh_info = sm_table[sh->sh_info].s->sh_num; + /* update backward link */ + s1->sections[s->sh_info]->reloc = s; + } + } + + /* resolve symbols */ + old_to_new_syms = tcc_mallocz(nb_syms * sizeof(int)); + + sym = symtab + 1; + for(i = 1; i < nb_syms; i++, sym++) { + if (sym->st_shndx != SHN_UNDEF && + sym->st_shndx < SHN_LORESERVE) { + sm = &sm_table[sym->st_shndx]; + if (sm->link_once) { + /* if a symbol is in a link once section, we use the + already defined symbol. It is very important to get + correct relocations */ + if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) { + name = strtab + sym->st_name; + sym_index = find_elf_sym(symtab_section, name); + if (sym_index) + old_to_new_syms[i] = sym_index; + } + continue; + } + /* if no corresponding section added, no need to add symbol */ + if (!sm->s) + continue; + /* convert section number */ + sym->st_shndx = sm->s->sh_num; + /* offset value */ + sym->st_value += sm->offset; + } + /* add symbol */ + name = strtab + sym->st_name; + sym_index = set_elf_sym(symtab_section, sym->st_value, sym->st_size, + sym->st_info, sym->st_other, + sym->st_shndx, name); + old_to_new_syms[i] = sym_index; + } + + /* third pass to patch relocation entries */ + for(i = 1; i < ehdr.e_shnum; i++) { + s = sm_table[i].s; + if (!s) + continue; + sh = &shdr[i]; + offset = sm_table[i].offset; + size = sh->sh_size; + switch(s->sh_type) { + case SHT_RELX: + /* take relocation offset information */ + offseti = sm_table[sh->sh_info].offset; + for (rel = (ElfW_Rel *) s->data + (offset / sizeof(*rel)); + rel < (ElfW_Rel *) s->data + ((offset + size) / sizeof(*rel)); + rel++) { + int type; + unsigned sym_index; + /* convert symbol index */ + type = ELFW(R_TYPE)(rel->r_info); + sym_index = ELFW(R_SYM)(rel->r_info); + /* NOTE: only one symtab assumed */ + if (sym_index >= nb_syms) + goto invalid_reloc; + sym_index = old_to_new_syms[sym_index]; + /* ignore link_once in rel section. */ + if (!sym_index && !sm_table[sh->sh_info].link_once +#ifdef TCC_TARGET_ARM + && type != R_ARM_V4BX +#elif defined TCC_TARGET_RISCV64 + && type != R_RISCV_ALIGN + && type != R_RISCV_RELAX +#endif + ) { + invalid_reloc: + tcc_error_noabort("Invalid relocation entry [%2d] '%s' @ %.8x", + i, strsec + sh->sh_name, (int)rel->r_offset); + goto the_end; + } + rel->r_info = ELFW(R_INFO)(sym_index, type); + /* offset the relocation offset */ + rel->r_offset += offseti; +#ifdef TCC_TARGET_ARM + /* Jumps and branches from a Thumb code to a PLT entry need + special handling since PLT entries are ARM code. + Unconditional bl instructions referencing PLT entries are + handled by converting these instructions into blx + instructions. Other case of instructions referencing a PLT + entry require to add a Thumb stub before the PLT entry to + switch to ARM mode. We set bit plt_thumb_stub of the + attribute of a symbol to indicate such a case. */ + if (type == R_ARM_THM_JUMP24) + get_sym_attr(s1, sym_index, 1)->plt_thumb_stub = 1; +#endif + } + break; + default: + break; + } + } + + ret = 0; + the_end: + tcc_free(symtab); + tcc_free(strtab); + tcc_free(old_to_new_syms); + tcc_free(sm_table); + tcc_free(strsec); + tcc_free(shdr); + return ret; +} + +typedef struct ArchiveHeader { + char ar_name[16]; /* name of this member */ + char ar_date[12]; /* file mtime */ + char ar_uid[6]; /* owner uid; printed as decimal */ + char ar_gid[6]; /* owner gid; printed as decimal */ + char ar_mode[8]; /* file mode, printed as octal */ + char ar_size[10]; /* file size, printed as decimal */ + char ar_fmag[2]; /* should contain ARFMAG */ +} ArchiveHeader; + +#define ARFMAG "`\n" + +static unsigned long long get_be(const uint8_t *b, int n) +{ + unsigned long long ret = 0; + while (n) + ret = (ret << 8) | *b++, --n; + return ret; +} + +static int read_ar_header(int fd, int offset, ArchiveHeader *hdr) +{ + char *p, *e; + int len; + lseek(fd, offset, SEEK_SET); + len = full_read(fd, hdr, sizeof(ArchiveHeader)); + if (len != sizeof(ArchiveHeader)) + return len ? -1 : 0; + p = hdr->ar_name; + for (e = p + sizeof hdr->ar_name; e > p && e[-1] == ' ';) + --e; + *e = '\0'; + hdr->ar_size[sizeof hdr->ar_size-1] = 0; + return len; +} + +/* load only the objects which resolve undefined symbols */ +static int tcc_load_alacarte(TCCState *s1, int fd, int size, int entrysize) +{ + int i, bound, nsyms, sym_index, len, ret = -1; + unsigned long long off; + uint8_t *data; + const char *ar_names, *p; + const uint8_t *ar_index; + ElfW(Sym) *sym; + ArchiveHeader hdr; + + data = tcc_malloc(size); + if (full_read(fd, data, size) != size) + goto the_end; + nsyms = get_be(data, entrysize); + ar_index = data + entrysize; + ar_names = (char *) ar_index + nsyms * entrysize; + + do { + bound = 0; + for (p = ar_names, i = 0; i < nsyms; i++, p += strlen(p)+1) { + Section *s = symtab_section; + sym_index = find_elf_sym(s, p); + if (!sym_index) + continue; + sym = &((ElfW(Sym) *)s->data)[sym_index]; + if(sym->st_shndx != SHN_UNDEF) + continue; + off = get_be(ar_index + i * entrysize, entrysize); + len = read_ar_header(fd, off, &hdr); + if (len <= 0 || memcmp(hdr.ar_fmag, ARFMAG, 2)) { + tcc_error_noabort("invalid archive"); + goto the_end; + } + off += len; + if (s1->verbose == 2) + printf(" -> %s\n", hdr.ar_name); + if (tcc_load_object_file(s1, fd, off) < 0) + goto the_end; + ++bound; + } + } while(bound); + ret = 0; + the_end: + tcc_free(data); + return ret; +} + +/* load a '.a' file */ +ST_FUNC int tcc_load_archive(TCCState *s1, int fd, int alacarte) +{ + ArchiveHeader hdr; + /* char magic[8]; */ + int size, len; + unsigned long file_offset; + ElfW(Ehdr) ehdr; + + /* skip magic which was already checked */ + /* full_read(fd, magic, sizeof(magic)); */ + file_offset = sizeof ARMAG - 1; + + for(;;) { + len = read_ar_header(fd, file_offset, &hdr); + if (len == 0) + return 0; + if (len < 0) + return tcc_error_noabort("invalid archive"); + file_offset += len; + size = strtol(hdr.ar_size, NULL, 0); + /* align to even */ + size = (size + 1) & ~1; + if (alacarte) { + /* coff symbol table : we handle it */ + if (!strcmp(hdr.ar_name, "/")) + return tcc_load_alacarte(s1, fd, size, 4); + if (!strcmp(hdr.ar_name, "/SYM64/")) + return tcc_load_alacarte(s1, fd, size, 8); + } else if (tcc_object_type(fd, &ehdr) == AFF_BINTYPE_REL) { + if (s1->verbose == 2) + printf(" -> %s\n", hdr.ar_name); + if (tcc_load_object_file(s1, fd, file_offset) < 0) + return -1; + } + file_offset += size; + } +} + +#ifndef ELF_OBJ_ONLY +/* Set LV[I] to the global index of sym-version (LIB,VERSION). Maybe resizes + LV, maybe create a new entry for (LIB,VERSION). */ +static void set_ver_to_ver(TCCState *s1, int *n, int **lv, int i, char *lib, char *version) +{ + while (i >= *n) { + *lv = tcc_realloc(*lv, (*n + 1) * sizeof(**lv)); + (*lv)[(*n)++] = -1; + } + if ((*lv)[i] == -1) { + int v, prev_same_lib = -1; + for (v = 0; v < nb_sym_versions; v++) { + if (strcmp(sym_versions[v].lib, lib)) + continue; + prev_same_lib = v; + if (!strcmp(sym_versions[v].version, version)) + break; + } + if (v == nb_sym_versions) { + sym_versions = tcc_realloc (sym_versions, + (v + 1) * sizeof(*sym_versions)); + sym_versions[v].lib = tcc_strdup(lib); + sym_versions[v].version = tcc_strdup(version); + sym_versions[v].out_index = 0; + sym_versions[v].prev_same_lib = prev_same_lib; + nb_sym_versions++; + } + (*lv)[i] = v; + } +} + +/* Associates symbol SYM_INDEX (in dynsymtab) with sym-version index + VERNDX. */ +static void +set_sym_version(TCCState *s1, int sym_index, int verndx) +{ + if (sym_index >= nb_sym_to_version) { + int newelems = sym_index ? sym_index * 2 : 1; + sym_to_version = tcc_realloc(sym_to_version, + newelems * sizeof(*sym_to_version)); + memset(sym_to_version + nb_sym_to_version, -1, + (newelems - nb_sym_to_version) * sizeof(*sym_to_version)); + nb_sym_to_version = newelems; + } + if (sym_to_version[sym_index] < 0) + sym_to_version[sym_index] = verndx; +} + +struct versym_info { + int nb_versyms; + ElfW(Verdef) *verdef; + ElfW(Verneed) *verneed; + ElfW(Half) *versym; + int nb_local_ver, *local_ver; +}; + + +static void store_version(TCCState *s1, struct versym_info *v, char *dynstr) +{ + char *lib, *version; + uint32_t next; + int i; + +#define DEBUG_VERSION 0 + + if (v->versym && v->verdef) { + ElfW(Verdef) *vdef = v->verdef; + lib = NULL; + do { + ElfW(Verdaux) *verdaux = + (ElfW(Verdaux) *) (((char *) vdef) + vdef->vd_aux); + +#if DEBUG_VERSION + printf ("verdef: version:%u flags:%u index:%u, hash:%u\n", + vdef->vd_version, vdef->vd_flags, vdef->vd_ndx, + vdef->vd_hash); +#endif + if (vdef->vd_cnt) { + version = dynstr + verdaux->vda_name; + + if (lib == NULL) + lib = version; + else + set_ver_to_ver(s1, &v->nb_local_ver, &v->local_ver, vdef->vd_ndx, + lib, version); +#if DEBUG_VERSION + printf (" verdaux(%u): %s\n", vdef->vd_ndx, version); +#endif + } + next = vdef->vd_next; + vdef = (ElfW(Verdef) *) (((char *) vdef) + next); + } while (next); + } + if (v->versym && v->verneed) { + ElfW(Verneed) *vneed = v->verneed; + do { + ElfW(Vernaux) *vernaux = + (ElfW(Vernaux) *) (((char *) vneed) + vneed->vn_aux); + + lib = dynstr + vneed->vn_file; +#if DEBUG_VERSION + printf ("verneed: %u %s\n", vneed->vn_version, lib); +#endif + for (i = 0; i < vneed->vn_cnt; i++) { + if ((vernaux->vna_other & 0x8000) == 0) { /* hidden */ + version = dynstr + vernaux->vna_name; + set_ver_to_ver(s1, &v->nb_local_ver, &v->local_ver, vernaux->vna_other, + lib, version); +#if DEBUG_VERSION + printf (" vernaux(%u): %u %u %s\n", + vernaux->vna_other, vernaux->vna_hash, + vernaux->vna_flags, version); +#endif + } + vernaux = (ElfW(Vernaux) *) (((char *) vernaux) + vernaux->vna_next); + } + next = vneed->vn_next; + vneed = (ElfW(Verneed) *) (((char *) vneed) + next); + } while (next); + } + +#if DEBUG_VERSION + for (i = 0; i < v->nb_local_ver; i++) { + if (v->local_ver[i] > 0) { + printf ("%d: lib: %s, version %s\n", + i, sym_versions[v->local_ver[i]].lib, + sym_versions[v->local_ver[i]].version); + } + } +#endif +} + +/* load a DLL and all referenced DLLs. 'level = 0' means that the DLL + is referenced by the user (so it should be added as DT_NEEDED in + the generated ELF file) */ +ST_FUNC int tcc_load_dll(TCCState *s1, int fd, const char *filename, int level) +{ + ElfW(Ehdr) ehdr; + ElfW(Shdr) *shdr, *sh, *sh1; + int i, nb_syms, nb_dts, sym_bind, ret = -1; + ElfW(Sym) *sym, *dynsym; + ElfW(Dyn) *dt, *dynamic; + + char *dynstr; + int sym_index; + const char *name, *soname; + struct versym_info v; + + full_read(fd, &ehdr, sizeof(ehdr)); + + /* test CPU specific stuff */ + if (ehdr.e_ident[5] != ELFDATA2LSB || + ehdr.e_machine != EM_TCC_TARGET) { + return tcc_error_noabort("bad architecture"); + } + + /* read sections */ + shdr = load_data(fd, ehdr.e_shoff, sizeof(ElfW(Shdr)) * ehdr.e_shnum); + + /* load dynamic section and dynamic symbols */ + nb_syms = 0; + nb_dts = 0; + dynamic = NULL; + dynsym = NULL; /* avoid warning */ + dynstr = NULL; /* avoid warning */ + memset(&v, 0, sizeof v); + + for(i = 0, sh = shdr; i < ehdr.e_shnum; i++, sh++) { + switch(sh->sh_type) { + case SHT_DYNAMIC: + nb_dts = sh->sh_size / sizeof(ElfW(Dyn)); + dynamic = load_data(fd, sh->sh_offset, sh->sh_size); + break; + case SHT_DYNSYM: + nb_syms = sh->sh_size / sizeof(ElfW(Sym)); + dynsym = load_data(fd, sh->sh_offset, sh->sh_size); + sh1 = &shdr[sh->sh_link]; + dynstr = load_data(fd, sh1->sh_offset, sh1->sh_size); + break; + case SHT_GNU_verdef: + v.verdef = load_data(fd, sh->sh_offset, sh->sh_size); + break; + case SHT_GNU_verneed: + v.verneed = load_data(fd, sh->sh_offset, sh->sh_size); + break; + case SHT_GNU_versym: + v.nb_versyms = sh->sh_size / sizeof(ElfW(Half)); + v.versym = load_data(fd, sh->sh_offset, sh->sh_size); + break; + default: + break; + } + } + + if (!dynamic) + goto the_end; + + /* compute the real library name */ + soname = tcc_basename(filename); + for(i = 0, dt = dynamic; i < nb_dts; i++, dt++) + if (dt->d_tag == DT_SONAME) + soname = dynstr + dt->d_un.d_val; + + /* if the dll is already loaded, do not load it */ + if (tcc_add_dllref(s1, soname, level)->found) + goto ret_success; + + if (v.nb_versyms != nb_syms) + tcc_free (v.versym), v.versym = NULL; + else + store_version(s1, &v, dynstr); + + /* add dynamic symbols in dynsym_section */ + for(i = 1, sym = dynsym + 1; i < nb_syms; i++, sym++) { + sym_bind = ELFW(ST_BIND)(sym->st_info); + if (sym_bind == STB_LOCAL) + continue; + name = dynstr + sym->st_name; + sym_index = set_elf_sym(s1->dynsymtab_section, sym->st_value, sym->st_size, + sym->st_info, sym->st_other, sym->st_shndx, name); + if (v.versym) { + ElfW(Half) vsym = v.versym[i]; + if ((vsym & 0x8000) == 0 && vsym > 0 && vsym < v.nb_local_ver) + set_sym_version(s1, sym_index, v.local_ver[vsym]); + } + } + + for(i = 0, dt = dynamic; i < nb_dts; i++, dt++) + if (dt->d_tag == DT_RPATH) + tcc_add_library_path(s1, dynstr + dt->d_un.d_val); + + /* load all referenced DLLs */ + for(i = 0, dt = dynamic; i < nb_dts; i++, dt++) { + switch(dt->d_tag) { + case DT_NEEDED: + name = dynstr + dt->d_un.d_val; + if (tcc_add_dllref(s1, name, -1)) + continue; + if (tcc_add_dll(s1, name, AFF_REFERENCED_DLL) < 0) { + ret = tcc_error_noabort("referenced dll '%s' not found", name); + goto the_end; + } + } + } + + ret_success: + ret = 0; + the_end: + tcc_free(dynstr); + tcc_free(dynsym); + tcc_free(dynamic); + tcc_free(shdr); + tcc_free(v.local_ver); + tcc_free(v.verdef); + tcc_free(v.verneed); + tcc_free(v.versym); + return ret; +} + +#define LD_TOK_NAME 256 +#define LD_TOK_EOF (-1) + +static int ld_inp(TCCState *s1) +{ + char b; + if (s1->cc != -1) { + int c = s1->cc; + s1->cc = -1; + return c; + } + if (1 == read(s1->fd, &b, 1)) + return b; + return CH_EOF; +} + +/* return next ld script token */ +static int ld_next(TCCState *s1, char *name, int name_size) +{ + int c, d, ch; + char *q; + + redo: + ch = ld_inp(s1); + switch(ch) { + case ' ': + case '\t': + case '\f': + case '\v': + case '\r': + case '\n': + goto redo; + case '/': + ch = ld_inp(s1); + if (ch == '*') { /* comment */ + for (d = 0;; d = ch) { + ch = ld_inp(s1); + if (ch == CH_EOF || (ch == '/' && d == '*')) + break; + } + goto redo; + } else { + q = name; + *q++ = '/'; + goto parse_name; + } + break; + case '\\': + /* case 'a' ... 'z': */ + case 'a': + case 'b': + case 'c': + case 'd': + case 'e': + case 'f': + case 'g': + case 'h': + case 'i': + case 'j': + case 'k': + case 'l': + case 'm': + case 'n': + case 'o': + case 'p': + case 'q': + case 'r': + case 's': + case 't': + case 'u': + case 'v': + case 'w': + case 'x': + case 'y': + case 'z': + /* case 'A' ... 'z': */ + case 'A': + case 'B': + case 'C': + case 'D': + case 'E': + case 'F': + case 'G': + case 'H': + case 'I': + case 'J': + case 'K': + case 'L': + case 'M': + case 'N': + case 'O': + case 'P': + case 'Q': + case 'R': + case 'S': + case 'T': + case 'U': + case 'V': + case 'W': + case 'X': + case 'Y': + case 'Z': + case '_': + case '.': + case '$': + case '~': + q = name; + parse_name: + for(;;) { + if (!((ch >= 'a' && ch <= 'z') || + (ch >= 'A' && ch <= 'Z') || + (ch >= '0' && ch <= '9') || + strchr("/.-_+=$:\\,~", ch))) + break; + if ((q - name) < name_size - 1) { + *q++ = ch; + } + ch = ld_inp(s1); + } + s1->cc = ch; + *q = '\0'; + c = LD_TOK_NAME; + break; + case CH_EOF: + c = LD_TOK_EOF; + break; + default: + c = ch; + break; + } + return c; +} + +static int ld_add_file(TCCState *s1, const char filename[]) +{ + if (filename[0] == '/') { + if (CONFIG_SYSROOT[0] == '\0' + && tcc_add_file_internal(s1, filename, AFF_TYPE_BIN) == 0) + return 0; + filename = tcc_basename(filename); + } + return tcc_add_dll(s1, filename, 0); +} + +static int ld_add_file_list(TCCState *s1, const char *cmd, int as_needed) +{ + char filename[1024], libname[1024]; + int t, group, nblibs = 0, ret = 0; + char **libs = NULL; + + group = !strcmp(cmd, "GROUP"); + if (!as_needed) + s1->new_undef_sym = 0; + t = ld_next(s1, filename, sizeof(filename)); + if (t != '(') { + ret = tcc_error_noabort("( expected"); + goto lib_parse_error; + } + t = ld_next(s1, filename, sizeof(filename)); + for(;;) { + libname[0] = '\0'; + if (t == LD_TOK_EOF) { + ret = tcc_error_noabort("unexpected end of file"); + goto lib_parse_error; + } else if (t == ')') { + break; + } else if (t == '-') { + t = ld_next(s1, filename, sizeof(filename)); + if ((t != LD_TOK_NAME) || (filename[0] != 'l')) { + ret = tcc_error_noabort("library name expected"); + goto lib_parse_error; + } + pstrcpy(libname, sizeof libname, &filename[1]); + if (s1->static_link) { + snprintf(filename, sizeof filename, "lib%s.a", libname); + } else { + snprintf(filename, sizeof filename, "lib%s.so", libname); + } + } else if (t != LD_TOK_NAME) { + ret = tcc_error_noabort("filename expected"); + goto lib_parse_error; + } + if (!strcmp(filename, "AS_NEEDED")) { + ret = ld_add_file_list(s1, cmd, 1); + if (ret) + goto lib_parse_error; + } else { + /* TODO: Implement AS_NEEDED support. Ignore it for now */ + if (!as_needed) { + ret = ld_add_file(s1, filename); + if (ret) + goto lib_parse_error; + if (group) { + /* Add the filename *and* the libname to avoid future conversions */ + dynarray_add(&libs, &nblibs, tcc_strdup(filename)); + if (libname[0] != '\0') + dynarray_add(&libs, &nblibs, tcc_strdup(libname)); + } + } + } + t = ld_next(s1, filename, sizeof(filename)); + if (t == ',') { + t = ld_next(s1, filename, sizeof(filename)); + } + } + if (group && !as_needed) { + while (s1->new_undef_sym) { + int i; + s1->new_undef_sym = 0; + for (i = 0; i < nblibs; i ++) + ld_add_file(s1, libs[i]); + } + } +lib_parse_error: + dynarray_reset(&libs, &nblibs); + return ret; +} + +/* interpret a subset of GNU ldscripts to handle the dummy libc.so + files */ +ST_FUNC int tcc_load_ldscript(TCCState *s1, int fd) +{ + char cmd[64]; + char filename[1024]; + int t, ret; + + s1->fd = fd; + s1->cc = -1; + for(;;) { + t = ld_next(s1, cmd, sizeof(cmd)); + if (t == LD_TOK_EOF) + return 0; + else if (t != LD_TOK_NAME) + return -1; + if (!strcmp(cmd, "INPUT") || + !strcmp(cmd, "GROUP")) { + ret = ld_add_file_list(s1, cmd, 0); + if (ret) + return ret; + } else if (!strcmp(cmd, "OUTPUT_FORMAT") || + !strcmp(cmd, "TARGET")) { + /* ignore some commands */ + t = ld_next(s1, cmd, sizeof(cmd)); + if (t != '(') + return tcc_error_noabort("( expected"); + for(;;) { + t = ld_next(s1, filename, sizeof(filename)); + if (t == LD_TOK_EOF) { + return tcc_error_noabort("unexpected end of file"); + } else if (t == ')') { + break; + } + } + } else { + return -1; + } + } + return 0; +} +#endif /* !ELF_OBJ_ONLY */ |