diff options
author | pommicket <pommicket@gmail.com> | 2022-02-17 13:22:13 -0500 |
---|---|---|
committer | pommicket <pommicket@gmail.com> | 2022-02-17 13:22:13 -0500 |
commit | e900dd8d6f2ff7cef66fbd31898d375b71ef53d6 (patch) | |
tree | ae732e8f5d6163acb78355ae4e5ca69d6e0c995e /05/tcc-0.9.25/tccelf.c | |
parent | 6e1158f49aa014b801b171b358c47389e7f9964e (diff) |
procuding a (non-working) executable for tcc
Diffstat (limited to '05/tcc-0.9.25/tccelf.c')
-rw-r--r-- | 05/tcc-0.9.25/tccelf.c | 2732 |
1 files changed, 2732 insertions, 0 deletions
diff --git a/05/tcc-0.9.25/tccelf.c b/05/tcc-0.9.25/tccelf.c new file mode 100644 index 0000000..5da02e1 --- /dev/null +++ b/05/tcc-0.9.25/tccelf.c @@ -0,0 +1,2732 @@ +/* + * 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 + */ + +#ifdef TCC_TARGET_X86_64 +#define ElfW_Rel ElfW(Rela) +#define SHT_RELX SHT_RELA +#define REL_SECTION_FMT ".rela%s" +/* x86-64 requires PLT for DLLs */ +#define TCC_OUTPUT_DLL_WITH_PLT +#else +#define ElfW_Rel ElfW(Rel) +#define SHT_RELX SHT_REL +#define REL_SECTION_FMT ".rel%s" +#endif + +/* XXX: DLL with PLT would only work with x86-64 for now */ +//#define TCC_OUTPUT_DLL_WITH_PLT + +static 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); + memcpy(ptr, sym, len); + return offset; +} + +/* elf symbol hashing function */ +static unsigned long elf_hash(const unsigned char *name) +{ + unsigned long 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; + char *strtab; + + strtab = s->link->data; + nb_syms = s->data_offset / sizeof(ElfW(Sym)); + + 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 (ELF64_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 */ +static int put_elf_sym(Section *s, + unsigned long 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_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 (ELF64_ST_BIND(info) != STB_LOCAL) { + /* add another hashing entry */ + nbuckets = base[0]; + h = elf_hash(name) % 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; +} + +/* find global ELF symbol 'name' and return its index. Return 0 if not + found. */ +static 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(name) % nbuckets; + sym_index = ((int *)hs->data)[2 + h]; + while (sym_index != 0) { + sym = &((ElfW(Sym) *)s->data)[sym_index]; + name1 = 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 or error */ +void *tcc_get_symbol(TCCState *s, const char *name) +{ + int sym_index; + ElfW(Sym) *sym; + sym_index = find_elf_sym(symtab_section, name); + if (!sym_index) + return NULL; + sym = &((ElfW(Sym) *)symtab_section->data)[sym_index]; + return (void*)(long)sym->st_value; +} + +void *tcc_get_symbol_err(TCCState *s, const char *name) +{ + void *sym; + sym = tcc_get_symbol(s, name); + if (!sym) + error("%s not defined", name); + return sym; +} + +/* add an elf symbol : check if it is already defined and patch + it. Return symbol index. NOTE that sh_num can be SHN_UNDEF. */ +static int add_elf_sym(Section *s, unsigned long value, unsigned long size, + int info, int other, int sh_num, const char *name) +{ + ElfW(Sym) *esym; + int sym_bind, sym_index, sym_type, esym_bind; + unsigned char sym_vis, esym_vis, new_vis; + + sym_bind = ELF64_ST_BIND(info); + sym_type = ELF64_ST_TYPE(info); + sym_vis = ELF64_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_shndx != SHN_UNDEF) { + esym_bind = ELF64_ST_BIND(esym->st_info); + /* propagate the most constraining visibility */ + /* STV_DEFAULT(0)<STV_PROTECTED(3)<STV_HIDDEN(2)<STV_INTERNAL(1) */ + esym_vis = ELF64_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 & ~ELF64_ST_VISIBILITY(-1)) + | new_vis; + other = esym->st_other; /* in case we have to patch esym */ + if (sh_num == 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_vis == STV_HIDDEN || sym_vis == STV_INTERNAL) { + /* ignore hidden symbols after */ + } else if (esym->st_shndx == SHN_COMMON && sh_num < SHN_LORESERVE) { + /* gr: Happens with 'tcc ... -static tcctest.c' on e.g. Ubuntu 6.01 + No idea if this is the correct solution ... */ + goto do_patch; + } else if (s == tcc_state->dynsymtab_section) { + /* we accept that two DLL define the same symbol */ + } else { +#if 1 + printf("new_bind=%x new_shndx=%x new_vis=%x old_bind=%x old_shndx=%x old_vis=%x\n", + sym_bind, sh_num, new_vis, esym_bind, esym->st_shndx, esym_vis); +#endif + error_noabort("'%s' defined twice", name); + } + } else { + do_patch: + esym->st_info = ELF64_ST_INFO(sym_bind, sym_type); + esym->st_shndx = sh_num; + esym->st_value = value; + esym->st_size = size; + esym->st_other = other; + } + } else { + do_def: + sym_index = put_elf_sym(s, value, size, + ELF64_ST_INFO(sym_bind, sym_type), other, + sh_num, name); + } + return sym_index; +} + +/* put relocation */ +static void put_elf_reloc(Section *symtab, Section *s, unsigned long offset, + int type, int symbol) +{ + 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(tcc_state, 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 = ELF64_R_INFO(symbol, type); +#ifdef TCC_TARGET_X86_64 + rel->r_addend = 0; +#endif +} + +/* put stab debug information */ + +typedef struct { + unsigned int n_strx; /* index into string table of name */ + unsigned char n_type; /* type of symbol */ + unsigned char n_other; /* misc info (usually empty) */ + unsigned short n_desc; /* description field */ + unsigned int n_value; /* value of symbol */ +} Stab_Sym; + +static void put_stabs(const char *str, int type, int other, int desc, + unsigned long value) +{ + Stab_Sym *sym; + + sym = section_ptr_add(stab_section, sizeof(Stab_Sym)); + if (str) { + sym->n_strx = put_elf_str(stabstr_section, str); + } else { + sym->n_strx = 0; + } + sym->n_type = type; + sym->n_other = other; + sym->n_desc = desc; + sym->n_value = value; +} + +static void put_stabs_r(const char *str, int type, int other, int desc, + unsigned long value, Section *sec, int sym_index) +{ + put_stabs(str, type, other, desc, value); + put_elf_reloc(symtab_section, stab_section, + stab_section->data_offset - sizeof(unsigned int), + R_DATA_32, sym_index); +} + +static void put_stabn(int type, int other, int desc, int value) +{ + put_stabs(NULL, type, other, desc, value); +} + +static void put_stabd(int type, int other, int desc) +{ + put_stabs(NULL, type, other, desc, 0); +} + +/* 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; + ElfW_Rel *rel, *rel_end; + Section *sr; + int type, sym_index; + + 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 (ELF64_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 */ + 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 (ELF64_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); + + /* now we modify all the relocations */ + for(i = 1; i < s1->nb_sections; i++) { + sr = s1->sections[i]; + if (sr->sh_type == SHT_RELX && sr->link == s) { + rel_end = (ElfW_Rel *)(sr->data + sr->data_offset); + for(rel = (ElfW_Rel *)sr->data; + rel < rel_end; + rel++) { + sym_index = ELF64_R_SYM(rel->r_info); + type = ELF64_R_TYPE(rel->r_info); + sym_index = old_to_new_syms[sym_index]; + rel->r_info = ELF64_R_INFO(sym_index, type); + } + } + } + + tcc_free(old_to_new_syms); +} + +/* relocate common symbols in the .bss section */ +static void relocate_common_syms(void) +{ + ElfW(Sym) *sym, *sym_end; + unsigned long offset, align; + + sym_end = (ElfW(Sym) *)(symtab_section->data + symtab_section->data_offset); + for(sym = (ElfW(Sym) *)symtab_section->data + 1; + sym < sym_end; + sym++) { + if (sym->st_shndx == SHN_COMMON) { + /* align symbol */ + align = sym->st_value; + offset = bss_section->data_offset; + offset = (offset + align - 1) & -align; + sym->st_value = offset; + sym->st_shndx = bss_section->sh_num; + offset += sym->st_size; + bss_section->data_offset = offset; + } + } +} + +/* relocate symbol table, resolve undefined symbols if do_resolve is + true and output error if undefined symbol. */ +static void relocate_syms(TCCState *s1, int do_resolve) +{ + ElfW(Sym) *sym, *esym, *sym_end; + int sym_bind, sh_num, sym_index; + const char *name; + unsigned long addr; + + sym_end = (ElfW(Sym) *)(symtab_section->data + symtab_section->data_offset); + for(sym = (ElfW(Sym) *)symtab_section->data + 1; + sym < sym_end; + sym++) { + sh_num = sym->st_shndx; + if (sh_num == SHN_UNDEF) { + name = strtab_section->data + sym->st_name; + if (do_resolve) { + name = symtab_section->link->data + sym->st_name; + addr = (unsigned long)resolve_sym(s1, name, ELF64_ST_TYPE(sym->st_info)); + if (addr) { + sym->st_value = addr; + goto found; + } + } else if (s1->dynsym) { + /* if dynamic symbol exist, then use it */ + sym_index = find_elf_sym(s1->dynsym, name); + if (sym_index) { + esym = &((ElfW(Sym) *)s1->dynsym->data)[sym_index]; + sym->st_value = esym->st_value; + 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 = ELF64_ST_BIND(sym->st_info); + if (sym_bind == STB_WEAK) { + sym->st_value = 0; + } else { + 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: ; + } +} + +#ifdef TCC_TARGET_X86_64 +#define JMP_TABLE_ENTRY_SIZE 14 +static unsigned long add_jmp_table(TCCState *s1, unsigned long val) +{ + char *p = s1->runtime_plt_and_got + s1->runtime_plt_and_got_offset; + s1->runtime_plt_and_got_offset += JMP_TABLE_ENTRY_SIZE; + /* jmp *0x0(%rip) */ + p[0] = 0xff; + p[1] = 0x25; + *(int *)(p + 2) = 0; + *(unsigned long *)(p + 6) = val; + return (unsigned long)p; +} + +static unsigned long add_got_table(TCCState *s1, unsigned long val) +{ + unsigned long *p =(unsigned long *)(s1->runtime_plt_and_got + + s1->runtime_plt_and_got_offset); + s1->runtime_plt_and_got_offset += sizeof(void *); + *p = val; + return (unsigned long)p; +} +#endif + +/* relocate a given section (CPU dependent) */ +static void relocate_section(TCCState *s1, Section *s) +{ + Section *sr; + ElfW_Rel *rel, *rel_end, *qrel; + ElfW(Sym) *sym; + int type, sym_index; + unsigned char *ptr; + unsigned long val, addr; +#if defined TCC_TARGET_I386 || defined TCC_TARGET_X86_64 + int esym_index; +#endif + + sr = s->reloc; + rel_end = (ElfW_Rel *)(sr->data + sr->data_offset); + qrel = (ElfW_Rel *)sr->data; + for(rel = qrel; + rel < rel_end; + rel++) { + ptr = s->data + rel->r_offset; + + sym_index = ELF64_R_SYM(rel->r_info); + sym = &((ElfW(Sym) *)symtab_section->data)[sym_index]; + val = sym->st_value; +#ifdef TCC_TARGET_X86_64 + /* XXX: not tested */ + val += rel->r_addend; +#endif + type = ELF64_R_TYPE(rel->r_info); + addr = s->sh_addr + rel->r_offset; + + /* CPU specific */ + switch(type) { +#if defined(TCC_TARGET_I386) + case R_386_32: + if (s1->output_type == TCC_OUTPUT_DLL) { + esym_index = s1->symtab_to_dynsym[sym_index]; + qrel->r_offset = rel->r_offset; + if (esym_index) { + qrel->r_info = ELF64_R_INFO(esym_index, R_386_32); + qrel++; + break; + } else { + qrel->r_info = ELF64_R_INFO(0, R_386_RELATIVE); + qrel++; + } + } + *(int *)ptr += val; + break; + case R_386_PC32: + if (s1->output_type == TCC_OUTPUT_DLL) { + /* DLL relocation */ + esym_index = s1->symtab_to_dynsym[sym_index]; + if (esym_index) { + qrel->r_offset = rel->r_offset; + qrel->r_info = ELF64_R_INFO(esym_index, R_386_PC32); + qrel++; + break; + } + } + *(int *)ptr += val - addr; + break; + case R_386_PLT32: + *(int *)ptr += val - addr; + break; + case R_386_GLOB_DAT: + case R_386_JMP_SLOT: + *(int *)ptr = val; + break; + case R_386_GOTPC: + *(int *)ptr += s1->got->sh_addr - addr; + break; + case R_386_GOTOFF: + *(int *)ptr += val - s1->got->sh_addr; + break; + case R_386_GOT32: + /* we load the got offset */ + *(int *)ptr += s1->got_offsets[sym_index]; + break; +#elif defined(TCC_TARGET_ARM) + case R_ARM_PC24: + case R_ARM_CALL: + case R_ARM_JUMP24: + case R_ARM_PLT32: + { + int x; + x = (*(int *)ptr)&0xffffff; + (*(int *)ptr) &= 0xff000000; + if (x & 0x800000) + x -= 0x1000000; + x *= 4; + x += val - addr; + if((x & 3) != 0 || x >= 0x4000000 || x < -0x4000000) + error("can't relocate value at %x",addr); + x >>= 2; + x &= 0xffffff; + (*(int *)ptr) |= x; + } + break; + case R_ARM_PREL31: + { + int x; + x = (*(int *)ptr) & 0x7fffffff; + (*(int *)ptr) &= 0x80000000; + x = (x * 2) / 2; + x += val - addr; + if((x^(x>>1))&0x40000000) + error("can't relocate value at %x",addr); + (*(int *)ptr) |= x & 0x7fffffff; + } + case R_ARM_ABS32: + *(int *)ptr += val; + break; + case R_ARM_BASE_PREL: + *(int *)ptr += s1->got->sh_addr - addr; + break; + case R_ARM_GOTOFF32: + *(int *)ptr += val - s1->got->sh_addr; + break; + case R_ARM_GOT_BREL: + /* we load the got offset */ + *(int *)ptr += s1->got_offsets[sym_index]; + break; + case R_ARM_COPY: + break; + default: + fprintf(stderr,"FIXME: handle reloc type %x at %lx [%.8x] to %lx\n", + type,addr,(unsigned int )ptr,val); + break; +#elif defined(TCC_TARGET_C67) + case R_C60_32: + *(int *)ptr += val; + break; + case R_C60LO16: + { + uint32_t orig; + + /* put the low 16 bits of the absolute address */ + // add to what is already there + + orig = ((*(int *)(ptr )) >> 7) & 0xffff; + orig |= (((*(int *)(ptr+4)) >> 7) & 0xffff) << 16; + + //patch both at once - assumes always in pairs Low - High + + *(int *) ptr = (*(int *) ptr & (~(0xffff << 7)) ) | (((val+orig) & 0xffff) << 7); + *(int *)(ptr+4) = (*(int *)(ptr+4) & (~(0xffff << 7)) ) | ((((val+orig)>>16) & 0xffff) << 7); + } + break; + case R_C60HI16: + break; + default: + fprintf(stderr,"FIXME: handle reloc type %x at %lx [%.8x] to %lx\n", + type,addr,(unsigned int )ptr,val); + break; +#elif defined(TCC_TARGET_X86_64) + case R_X86_64_64: + if (s1->output_type == TCC_OUTPUT_DLL) { + qrel->r_info = ELF64_R_INFO(0, R_X86_64_RELATIVE); + qrel->r_addend = *(long long *)ptr + val; + qrel++; + } + *(long long *)ptr += val; + break; + case R_X86_64_32: + case R_X86_64_32S: + if (s1->output_type == TCC_OUTPUT_DLL) { + /* XXX: this logic may depend on TCC's codegen + now TCC uses R_X86_64_32 even for a 64bit pointer */ + qrel->r_info = ELF64_R_INFO(0, R_X86_64_RELATIVE); + qrel->r_addend = *(int *)ptr + val; + qrel++; + } + *(int *)ptr += val; + break; + case R_X86_64_PC32: { + if (s1->output_type == TCC_OUTPUT_DLL) { + /* DLL relocation */ + esym_index = s1->symtab_to_dynsym[sym_index]; + if (esym_index) { + qrel->r_offset = rel->r_offset; + qrel->r_info = ELF64_R_INFO(esym_index, R_X86_64_PC32); + qrel->r_addend = *(int *)ptr; + qrel++; + break; + } + } + long diff = val - addr; + if (diff <= -2147483647 || diff > 2147483647) { + /* XXX: naive support for over 32bit jump */ + if (s1->output_type == TCC_OUTPUT_MEMORY) { + val = add_jmp_table(s1, val); + diff = val - addr; + } + if (diff <= -2147483647 || diff > 2147483647) { + error("internal error: relocation failed"); + } + } + *(int *)ptr += diff; + } + break; + case R_X86_64_PLT32: + *(int *)ptr += val - addr; + break; + case R_X86_64_GLOB_DAT: + case R_X86_64_JUMP_SLOT: + *(int *)ptr = val; + break; + case R_X86_64_GOTPCREL: + if (s1->output_type == TCC_OUTPUT_MEMORY) { + val = add_got_table(s1, val - rel->r_addend) + rel->r_addend; + *(int *)ptr += val - addr; + break; + } + *(int *)ptr += (s1->got->sh_addr - addr + + s1->got_offsets[sym_index] - 4); + break; + case R_X86_64_GOTTPOFF: + *(int *)ptr += val - s1->got->sh_addr; + break; + case R_X86_64_GOT32: + /* we load the got offset */ + *(int *)ptr += s1->got_offsets[sym_index]; + break; +#else +#error unsupported processor +#endif + } + } + /* if the relocation is allocated, we change its symbol table */ + if (sr->sh_flags & SHF_ALLOC) + sr->link = s1->dynsym; +} + +/* relocate relocation table in 'sr' */ +static void relocate_rel(TCCState *s1, Section *sr) +{ + Section *s; + ElfW_Rel *rel, *rel_end; + + s = s1->sections[sr->sh_info]; + rel_end = (ElfW_Rel *)(sr->data + sr->data_offset); + for(rel = (ElfW_Rel *)sr->data; + rel < rel_end; + rel++) { + rel->r_offset += s->sh_addr; + } +} + +/* count the number of dynamic relocations so that we can reserve + their space */ +static int prepare_dynamic_rel(TCCState *s1, Section *sr) +{ + ElfW_Rel *rel, *rel_end; + int sym_index, esym_index, type, count; + + count = 0; + rel_end = (ElfW_Rel *)(sr->data + sr->data_offset); + for(rel = (ElfW_Rel *)sr->data; rel < rel_end; rel++) { + sym_index = ELF64_R_SYM(rel->r_info); + type = ELF64_R_TYPE(rel->r_info); + switch(type) { +#if defined(TCC_TARGET_I386) + case R_386_32: +#elif defined(TCC_TARGET_X86_64) + case R_X86_64_32: + case R_X86_64_32S: + case R_X86_64_64: +#endif + count++; + break; +#if defined(TCC_TARGET_I386) + case R_386_PC32: +#elif defined(TCC_TARGET_X86_64) + case R_X86_64_PC32: +#endif + esym_index = s1->symtab_to_dynsym[sym_index]; + if (esym_index) + count++; + break; + default: + break; + } + } + if (count) { + /* allocate the section */ + sr->sh_flags |= SHF_ALLOC; + sr->sh_size = count * sizeof(ElfW_Rel); + } + return count; +} + +static void put_got_offset(TCCState *s1, int index, unsigned long val) +{ + int n; + unsigned long *tab; + + if (index >= s1->nb_got_offsets) { + /* find immediately bigger power of 2 and reallocate array */ + n = 1; + while (index >= n) + n *= 2; + tab = tcc_realloc(s1->got_offsets, n * sizeof(unsigned long)); + if (!tab) + error("memory full"); + s1->got_offsets = tab; + memset(s1->got_offsets + s1->nb_got_offsets, 0, + (n - s1->nb_got_offsets) * sizeof(unsigned long)); + s1->nb_got_offsets = n; + } + s1->got_offsets[index] = val; +} + +/* XXX: suppress that */ +static void put32(unsigned char *p, uint32_t val) +{ + p[0] = val; + p[1] = val >> 8; + p[2] = val >> 16; + p[3] = val >> 24; +} + +#if defined(TCC_TARGET_I386) || defined(TCC_TARGET_ARM) || \ + defined(TCC_TARGET_X86_64) +static uint32_t get32(unsigned char *p) +{ + return p[0] | (p[1] << 8) | (p[2] << 16) | (p[3] << 24); +} +#endif + +static void build_got(TCCState *s1) +{ + unsigned char *ptr; + + /* if no got, then create it */ + s1->got = new_section(s1, ".got", SHT_PROGBITS, SHF_ALLOC | SHF_WRITE); + s1->got->sh_entsize = 4; + add_elf_sym(symtab_section, 0, 4, ELF64_ST_INFO(STB_GLOBAL, STT_OBJECT), + 0, s1->got->sh_num, "_GLOBAL_OFFSET_TABLE_"); + ptr = section_ptr_add(s1->got, 3 * PTR_SIZE); +#if PTR_SIZE == 4 + /* keep space for _DYNAMIC pointer, if present */ + put32(ptr, 0); + /* two dummy got entries */ + put32(ptr + 4, 0); + put32(ptr + 8, 0); +#else + /* keep space for _DYNAMIC pointer, if present */ + put32(ptr, 0); + put32(ptr + 4, 0); + /* two dummy got entries */ + put32(ptr + 8, 0); + put32(ptr + 12, 0); + put32(ptr + 16, 0); + put32(ptr + 20, 0); +#endif +} + +/* put a got entry corresponding to a symbol in symtab_section. 'size' + and 'info' can be modifed if more precise info comes from the DLL */ +static void put_got_entry(TCCState *s1, + int reloc_type, unsigned long size, int info, + int sym_index) +{ + int index; + const char *name; + ElfW(Sym) *sym; + unsigned long offset; + int *ptr; + + if (!s1->got) + build_got(s1); + + /* if a got entry already exists for that symbol, no need to add one */ + if (sym_index < s1->nb_got_offsets && + s1->got_offsets[sym_index] != 0) + return; + + put_got_offset(s1, sym_index, s1->got->data_offset); + + if (s1->dynsym) { + sym = &((ElfW(Sym) *)symtab_section->data)[sym_index]; + name = symtab_section->link->data + sym->st_name; + offset = sym->st_value; +#if defined(TCC_TARGET_I386) || defined(TCC_TARGET_X86_64) + if (reloc_type == +#ifdef TCC_TARGET_X86_64 + R_X86_64_JUMP_SLOT +#else + R_386_JMP_SLOT +#endif + ) { + Section *plt; + uint8_t *p; + int modrm; + +#if defined(TCC_OUTPUT_DLL_WITH_PLT) + modrm = 0x25; +#else + /* if we build a DLL, we add a %ebx offset */ + if (s1->output_type == TCC_OUTPUT_DLL) + modrm = 0xa3; + else + modrm = 0x25; +#endif + + /* add a PLT entry */ + plt = s1->plt; + if (plt->data_offset == 0) { + /* first plt entry */ + p = section_ptr_add(plt, 16); + p[0] = 0xff; /* pushl got + PTR_SIZE */ + p[1] = modrm + 0x10; + put32(p + 2, PTR_SIZE); + p[6] = 0xff; /* jmp *(got + PTR_SIZE * 2) */ + p[7] = modrm; + put32(p + 8, PTR_SIZE * 2); + } + + p = section_ptr_add(plt, 16); + p[0] = 0xff; /* jmp *(got + x) */ + p[1] = modrm; + put32(p + 2, s1->got->data_offset); + p[6] = 0x68; /* push $xxx */ + put32(p + 7, (plt->data_offset - 32) >> 1); + p[11] = 0xe9; /* jmp plt_start */ + put32(p + 12, -(plt->data_offset)); + + /* the symbol is modified so that it will be relocated to + the PLT */ +#if !defined(TCC_OUTPUT_DLL_WITH_PLT) + if (s1->output_type == TCC_OUTPUT_EXE) +#endif + offset = plt->data_offset - 16; + } +#elif defined(TCC_TARGET_ARM) + if (reloc_type == R_ARM_JUMP_SLOT) { + Section *plt; + uint8_t *p; + + /* if we build a DLL, we add a %ebx offset */ + if (s1->output_type == TCC_OUTPUT_DLL) + error("DLLs unimplemented!"); + + /* add a PLT entry */ + plt = s1->plt; + if (plt->data_offset == 0) { + /* first plt entry */ + p = section_ptr_add(plt, 16); + put32(p , 0xe52de004); + put32(p + 4, 0xe59fe010); + put32(p + 8, 0xe08fe00e); + put32(p + 12, 0xe5bef008); + } + + p = section_ptr_add(plt, 16); + put32(p , 0xe59fc004); + put32(p+4, 0xe08fc00c); + put32(p+8, 0xe59cf000); + put32(p+12, s1->got->data_offset); + + /* the symbol is modified so that it will be relocated to + the PLT */ + if (s1->output_type == TCC_OUTPUT_EXE) + offset = plt->data_offset - 16; + } +#elif defined(TCC_TARGET_C67) + error("C67 got not implemented"); +#else +#error unsupported CPU +#endif + index = put_elf_sym(s1->dynsym, offset, + size, info, 0, sym->st_shndx, name); + /* put a got entry */ + put_elf_reloc(s1->dynsym, s1->got, + s1->got->data_offset, + reloc_type, index); + } + ptr = section_ptr_add(s1->got, PTR_SIZE); + *ptr = 0; +} + +/* build GOT and PLT entries */ +static void build_got_entries(TCCState *s1) +{ + Section *s, *symtab; + ElfW_Rel *rel, *rel_end; + ElfW(Sym) *sym; + int i, type, reloc_type, sym_index; + + 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; + symtab = s->link; + rel_end = (ElfW_Rel *)(s->data + s->data_offset); + for(rel = (ElfW_Rel *)s->data; + rel < rel_end; + rel++) { + type = ELF64_R_TYPE(rel->r_info); + switch(type) { +#if defined(TCC_TARGET_I386) + case R_386_GOT32: + case R_386_GOTOFF: + case R_386_GOTPC: + case R_386_PLT32: + if (!s1->got) + build_got(s1); + if (type == R_386_GOT32 || type == R_386_PLT32) { + sym_index = ELF64_R_SYM(rel->r_info); + sym = &((ElfW(Sym) *)symtab_section->data)[sym_index]; + /* look at the symbol got offset. If none, then add one */ + if (type == R_386_GOT32) + reloc_type = R_386_GLOB_DAT; + else + reloc_type = R_386_JMP_SLOT; + put_got_entry(s1, reloc_type, sym->st_size, sym->st_info, + sym_index); + } + break; +#elif defined(TCC_TARGET_ARM) + case R_ARM_GOT_BREL: + case R_ARM_GOTOFF32: + case R_ARM_BASE_PREL: + case R_ARM_PLT32: + if (!s1->got) + build_got(s1); + if (type == R_ARM_GOT_BREL || type == R_ARM_PLT32) { + sym_index = ELF64_R_SYM(rel->r_info); + sym = &((ElfW(Sym) *)symtab_section->data)[sym_index]; + /* look at the symbol got offset. If none, then add one */ + if (type == R_ARM_GOT_BREL) + reloc_type = R_ARM_GLOB_DAT; + else + reloc_type = R_ARM_JUMP_SLOT; + put_got_entry(s1, reloc_type, sym->st_size, sym->st_info, + sym_index); + } + break; +#elif defined(TCC_TARGET_C67) + case R_C60_GOT32: + case R_C60_GOTOFF: + case R_C60_GOTPC: + case R_C60_PLT32: + if (!s1->got) + build_got(s1); + if (type == R_C60_GOT32 || type == R_C60_PLT32) { + sym_index = ELF64_R_SYM(rel->r_info); + sym = &((ElfW(Sym) *)symtab_section->data)[sym_index]; + /* look at the symbol got offset. If none, then add one */ + if (type == R_C60_GOT32) + reloc_type = R_C60_GLOB_DAT; + else + reloc_type = R_C60_JMP_SLOT; + put_got_entry(s1, reloc_type, sym->st_size, sym->st_info, + sym_index); + } + break; +#elif defined(TCC_TARGET_X86_64) + case R_X86_64_GOT32: + case R_X86_64_GOTTPOFF: + case R_X86_64_GOTPCREL: + case R_X86_64_PLT32: + if (!s1->got) + build_got(s1); + if (type == R_X86_64_GOT32 || type == R_X86_64_GOTPCREL || + type == R_X86_64_PLT32) { + sym_index = ELF64_R_SYM(rel->r_info); + sym = &((ElfW(Sym) *)symtab_section->data)[sym_index]; + /* look at the symbol got offset. If none, then add one */ + if (type == R_X86_64_GOT32 || type == R_X86_64_GOTPCREL) + reloc_type = R_X86_64_GLOB_DAT; + else + reloc_type = R_X86_64_JUMP_SLOT; + put_got_entry(s1, reloc_type, sym->st_size, sym->st_info, + sym_index); + } + break; +#else +#error unsupported CPU +#endif + default: + break; + } + } + } +} + +static 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; +} + +/* put dynamic tag */ +static void put_dt(Section *dynamic, int dt, unsigned long val) +{ + ElfW(Dyn) *dyn; + dyn = section_ptr_add(dynamic, sizeof(ElfW(Dyn))); + dyn->d_tag = dt; + dyn->d_un.d_val = val; +} + +static void add_init_array_defines(TCCState *s1, const char *section_name) +{ + Section *s; + long end_offset; + char sym_start[1024]; + char sym_end[1024]; + + snprintf(sym_start, sizeof(sym_start), "__%s_start", section_name + 1); + snprintf(sym_end, sizeof(sym_end), "__%s_end", section_name + 1); + + s = find_section(s1, section_name); + if (!s) { + end_offset = 0; + s = data_section; + } else { + end_offset = s->data_offset; + } + + add_elf_sym(symtab_section, + 0, 0, + ELF64_ST_INFO(STB_GLOBAL, STT_NOTYPE), 0, + s->sh_num, sym_start); + add_elf_sym(symtab_section, + end_offset, 0, + ELF64_ST_INFO(STB_GLOBAL, STT_NOTYPE), 0, + s->sh_num, sym_end); +} + +/* add tcc runtime libraries */ +static void tcc_add_runtime(TCCState *s1) +{ +#if defined(CONFIG_TCC_BCHECK) || !defined(CONFIG_USE_LIBGCC) + char buf[1024]; +#endif + +#ifdef CONFIG_TCC_BCHECK + if (s1->do_bounds_check) { + unsigned long *ptr; + Section *init_section; + unsigned char *pinit; + int sym_index; + + /* XXX: add an object file to do that */ + ptr = section_ptr_add(bounds_section, sizeof(unsigned long)); + *ptr = 0; + add_elf_sym(symtab_section, 0, 0, + ELF64_ST_INFO(STB_GLOBAL, STT_NOTYPE), 0, + bounds_section->sh_num, "__bounds_start"); + /* add bound check code */ + snprintf(buf, sizeof(buf), "%s/%s", s1->tcc_lib_path, "bcheck.o"); + tcc_add_file(s1, buf); +#ifdef TCC_TARGET_I386 + if (s1->output_type != TCC_OUTPUT_MEMORY) { + /* add 'call __bound_init()' in .init section */ + init_section = find_section(s1, ".init"); + pinit = section_ptr_add(init_section, 5); + pinit[0] = 0xe8; + put32(pinit + 1, -4); + sym_index = find_elf_sym(symtab_section, "__bound_init"); + put_elf_reloc(symtab_section, init_section, + init_section->data_offset - 4, R_386_PC32, sym_index); + } +#endif + } +#endif + /* add libc */ + if (!s1->nostdlib) { + tcc_add_library(s1, "c"); + +#ifdef CONFIG_USE_LIBGCC + tcc_add_file(s1, CONFIG_SYSROOT "/lib/libgcc_s.so.1"); +#else + snprintf(buf, sizeof(buf), "%s/%s", s1->tcc_lib_path, "libtcc1.a"); + tcc_add_file(s1, buf); +#endif + } + /* add crt end if not memory output */ + if (s1->output_type != TCC_OUTPUT_MEMORY && !s1->nostdlib) { + tcc_add_file(s1, CONFIG_TCC_CRT_PREFIX "/crtn.o"); + } +} + +/* 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; + + add_elf_sym(symtab_section, + text_section->data_offset, 0, + ELF64_ST_INFO(STB_GLOBAL, STT_NOTYPE), 0, + text_section->sh_num, "_etext"); + add_elf_sym(symtab_section, + data_section->data_offset, 0, + ELF64_ST_INFO(STB_GLOBAL, STT_NOTYPE), 0, + data_section->sh_num, "_edata"); + add_elf_sym(symtab_section, + bss_section->data_offset, 0, + ELF64_ST_INFO(STB_GLOBAL, STT_NOTYPE), 0, + bss_section->sh_num, "_end"); + /* 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_type == SHT_PROGBITS && + (s->sh_flags & SHF_ALLOC)) { + const char *p; + int ch; + + /* check if section name can be expressed in C */ + p = s->name; + for(;;) { + ch = *p; + if (!ch) + break; + if (!isid(ch) && !isnum(ch)) + goto next_sec; + p++; + } + snprintf(buf, sizeof(buf), "__start_%s", s->name); + add_elf_sym(symtab_section, + 0, 0, + ELF64_ST_INFO(STB_GLOBAL, STT_NOTYPE), 0, + s->sh_num, buf); + snprintf(buf, sizeof(buf), "__stop_%s", s->name); + add_elf_sym(symtab_section, + s->data_offset, 0, + ELF64_ST_INFO(STB_GLOBAL, STT_NOTYPE), 0, + s->sh_num, buf); + } + next_sec: ; + } +} + +/* name of ELF interpreter */ +#if defined __FreeBSD__ +static char elf_interp[] = "/usr/libexec/ld-elf.so.1"; +#elif defined TCC_ARM_EABI +static char elf_interp[] = "/lib/ld-linux.so.3"; +#elif defined(TCC_TARGET_X86_64) +static char elf_interp[] = "/lib/ld-linux-x86-64.so.2"; +#elif defined(TCC_UCLIBC) +static char elf_interp[] = "/lib/ld-uClibc.so.0"; +#else +static char elf_interp[] = "/lib/ld-linux.so.2"; +#endif + +static void tcc_output_binary(TCCState *s1, FILE *f, + const int *section_order) +{ + Section *s; + int i, offset, size; + + offset = 0; + for(i=1;i<s1->nb_sections;i++) { + s = s1->sections[section_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; + } + } +} + +/* output an ELF file */ +/* XXX: suppress unneeded sections */ +int elf_output_file(TCCState *s1, const char *filename) +{ + ElfW(Ehdr) ehdr; + FILE *f; + int fd, mode, ret; + int *section_order; + int shnum, i, phnum, file_offset, offset, size, j, tmp, sh_order_index, k; + unsigned long addr; + Section *strsec, *s; + ElfW(Shdr) shdr, *sh; + ElfW(Phdr) *phdr, *ph; + Section *interp, *dynamic, *dynstr; + unsigned long saved_dynamic_data_offset; + ElfW(Sym) *sym; + int type, file_type; + unsigned long rel_addr, rel_size; + + file_type = s1->output_type; + s1->nb_errors = 0; + + if (file_type != TCC_OUTPUT_OBJ) { + tcc_add_runtime(s1); + } + + phdr = NULL; + section_order = NULL; + interp = NULL; + dynamic = NULL; + dynstr = NULL; /* avoid warning */ + saved_dynamic_data_offset = 0; /* avoid warning */ + + if (file_type != TCC_OUTPUT_OBJ) { + relocate_common_syms(); + + tcc_add_linker_symbols(s1); + + if (!s1->static_link) { + const char *name; + int sym_index, index; + ElfW(Sym) *esym, *sym_end; + + if (file_type == TCC_OUTPUT_EXE) { + char *ptr; + /* add interpreter section only if executable */ + interp = new_section(s1, ".interp", SHT_PROGBITS, SHF_ALLOC); + interp->sh_addralign = 1; + ptr = section_ptr_add(interp, sizeof(elf_interp)); + strcpy(ptr, elf_interp); + } + + /* add dynamic symbol table */ + s1->dynsym = new_symtab(s1, ".dynsym", SHT_DYNSYM, SHF_ALLOC, + ".dynstr", + ".hash", SHF_ALLOC); + 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)); + + /* add PLT */ + s1->plt = new_section(s1, ".plt", SHT_PROGBITS, + SHF_ALLOC | SHF_EXECINSTR); + s1->plt->sh_entsize = 4; + + build_got(s1); + + /* scan for undefined symbols and see if they are in the + dynamic symbols. If a symbol STT_FUNC is found, then we + add it in the PLT. If a symbol STT_OBJECT is found, we + add it in the .bss section with a suitable relocation */ + sym_end = (ElfW(Sym) *)(symtab_section->data + + symtab_section->data_offset); + if (file_type == TCC_OUTPUT_EXE) { + for(sym = (ElfW(Sym) *)symtab_section->data + 1; + sym < sym_end; + sym++) { + if (sym->st_shndx == SHN_UNDEF) { + name = 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 = ELF64_ST_TYPE(esym->st_info); + if (type == STT_FUNC) { + put_got_entry(s1, R_JMP_SLOT, esym->st_size, + esym->st_info, + sym - (ElfW(Sym) *)symtab_section->data); + } else if (type == STT_OBJECT) { + unsigned long offset; + offset = bss_section->data_offset; + /* XXX: which alignment ? */ + offset = (offset + 16 - 1) & -16; + index = put_elf_sym(s1->dynsym, offset, esym->st_size, + esym->st_info, 0, + bss_section->sh_num, name); + 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 (ELF64_ST_BIND(sym->st_info) == STB_WEAK || + !strcmp(name, "_fp_hw")) { + } else { + error_noabort("undefined symbol '%s'", name); + } + } + } else if (s1->rdynamic && + ELF64_ST_BIND(sym->st_info) != STB_LOCAL) { + /* if -rdynamic option, then export all non + local symbols */ + name = symtab_section->link->data + sym->st_name; + put_elf_sym(s1->dynsym, sym->st_value, sym->st_size, + sym->st_info, 0, + sym->st_shndx, name); + } + } + + if (s1->nb_errors) + goto fail; + + /* now look at unresolved dynamic symbols and export + corresponding symbol */ + sym_end = (ElfW(Sym) *)(s1->dynsymtab_section->data + + s1->dynsymtab_section->data_offset); + for(esym = (ElfW(Sym) *)s1->dynsymtab_section->data + 1; + esym < sym_end; + esym++) { + if (esym->st_shndx == SHN_UNDEF) { + name = s1->dynsymtab_section->link->data + esym->st_name; + sym_index = find_elf_sym(symtab_section, name); + if (sym_index) { + /* XXX: avoid adding a symbol if already + present because of -rdynamic ? */ + sym = &((ElfW(Sym) *)symtab_section->data)[sym_index]; + put_elf_sym(s1->dynsym, sym->st_value, sym->st_size, + sym->st_info, 0, + sym->st_shndx, name); + } else { + if (ELF64_ST_BIND(esym->st_info) == STB_WEAK) { + /* weak symbols can stay undefined */ + } else { + warning("undefined dynamic symbol '%s'", name); + } + } + } + } + } else { + int nb_syms; + /* shared library case : we simply export all the global symbols */ + nb_syms = symtab_section->data_offset / sizeof(ElfW(Sym)); + s1->symtab_to_dynsym = tcc_mallocz(sizeof(int) * nb_syms); + for(sym = (ElfW(Sym) *)symtab_section->data + 1; + sym < sym_end; + sym++) { + if (ELF64_ST_BIND(sym->st_info) != STB_LOCAL) { +#if defined(TCC_OUTPUT_DLL_WITH_PLT) + if (ELF64_ST_TYPE(sym->st_info) == STT_FUNC && + sym->st_shndx == SHN_UNDEF) { + put_got_entry(s1, R_JMP_SLOT, sym->st_size, + sym->st_info, + sym - (ElfW(Sym) *)symtab_section->data); + } + else if (ELF64_ST_TYPE(sym->st_info) == STT_OBJECT) { + put_got_entry(s1, R_X86_64_GLOB_DAT, sym->st_size, + sym->st_info, + sym - (ElfW(Sym) *)symtab_section->data); + } + else +#endif + { + name = symtab_section->link->data + sym->st_name; + index = put_elf_sym(s1->dynsym, sym->st_value, sym->st_size, + sym->st_info, 0, + sym->st_shndx, name); + s1->symtab_to_dynsym[sym - + (ElfW(Sym) *)symtab_section->data] = + index; + } + } + } + } + + build_got_entries(s1); + + /* 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)); + } + /* XXX: currently, since we do not handle PIC code, we + must relocate the readonly segments */ + if (file_type == TCC_OUTPUT_DLL) { + if (s1->soname) + put_dt(dynamic, DT_SONAME, put_elf_str(dynstr, s1->soname)); + put_dt(dynamic, DT_TEXTREL, 0); + } + + /* add necessary space for other entries */ + saved_dynamic_data_offset = dynamic->data_offset; + dynamic->data_offset += sizeof(ElfW(Dyn)) * 9; + } else { + /* still need to build got entries in case of static link */ + build_got_entries(s1); + } + } + + memset(&ehdr, 0, sizeof(ehdr)); + + /* we add a section for symbols */ + strsec = new_section(s1, ".shstrtab", SHT_STRTAB, 0); + put_elf_str(strsec, ""); + + /* compute number of sections */ + shnum = s1->nb_sections; + + /* this array is used to reorder sections in the output file */ + section_order = tcc_malloc(sizeof(int) * shnum); + section_order[0] = 0; + sh_order_index = 1; + + /* compute number of program headers */ + switch(file_type) { + case TCC_OUTPUT_EXE: + if (!s1->static_link) + phnum = 4; + else + phnum = 2; + break; + case TCC_OUTPUT_DLL: + phnum = 3; + break; + case TCC_OUTPUT_OBJ: + default: + phnum = 0; + break; + } + + /* allocate strings for section names and decide if an unallocated + section should be output */ + /* NOTE: the strsec section comes last, so its size is also + correct ! */ + for(i = 1; i < s1->nb_sections; i++) { + s = s1->sections[i]; + s->sh_name = put_elf_str(strsec, s->name); +#if 0 //gr + printf("section: f=%08x t=%08x i=%08x %s %s\n", + s->sh_flags, + s->sh_type, + s->sh_info, + s->name, + s->reloc ? s->reloc->name : "n" + ); +#endif + /* when generating a DLL, we include relocations but we may + patch them */ + if (file_type == TCC_OUTPUT_DLL && + s->sh_type == SHT_RELX && + !(s->sh_flags & SHF_ALLOC)) { + /* //gr: avoid bogus relocs for empty (debug) sections */ + if (s1->sections[s->sh_info]->sh_flags & SHF_ALLOC) + prepare_dynamic_rel(s1, s); + else if (s1->do_debug) + s->sh_size = s->data_offset; + } else if (s1->do_debug || + file_type == TCC_OUTPUT_OBJ || + (s->sh_flags & SHF_ALLOC) || + i == (s1->nb_sections - 1)) { + /* we output all sections if debug or object file */ + s->sh_size = s->data_offset; + } + } + + /* allocate program segment headers */ + phdr = tcc_mallocz(phnum * sizeof(ElfW(Phdr))); + + if (s1->output_format == TCC_OUTPUT_FORMAT_ELF) { + file_offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr)); + } else { + file_offset = 0; + } + if (phnum > 0) { + /* compute section to program header mapping */ + if (s1->has_text_addr) { + int a_offset, p_offset; + addr = s1->text_addr; + /* we ensure that (addr % ELF_PAGE_SIZE) == file_offset % + ELF_PAGE_SIZE */ + a_offset = addr & (ELF_PAGE_SIZE - 1); + p_offset = file_offset & (ELF_PAGE_SIZE - 1); + if (a_offset < p_offset) + a_offset += ELF_PAGE_SIZE; + file_offset += (a_offset - p_offset); + } else { + if (file_type == TCC_OUTPUT_DLL) + addr = 0; + else + addr = ELF_START_ADDR; + /* compute address after headers */ + addr += (file_offset & (ELF_PAGE_SIZE - 1)); + } + + /* dynamic relocation table information, for .dynamic section */ + rel_size = 0; + rel_addr = 0; + + /* leave one program header for the program interpreter */ + ph = &phdr[0]; + if (interp) + ph++; + + for(j = 0; j < 2; j++) { + ph->p_type = PT_LOAD; + if (j == 0) + ph->p_flags = PF_R | PF_X; + else + ph->p_flags = PF_R | PF_W; + ph->p_align = ELF_PAGE_SIZE; + + /* we do the following ordering: interp, symbol tables, + relocations, progbits, nobits */ + /* XXX: do faster and simpler sorting */ + for(k = 0; k < 5; k++) { + for(i = 1; i < s1->nb_sections; i++) { + s = s1->sections[i]; + /* compute if section should be included */ + if (j == 0) { + if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) != + SHF_ALLOC) + continue; + } else { + if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) != + (SHF_ALLOC | SHF_WRITE)) + continue; + } + if (s == interp) { + if (k != 0) + continue; + } else if (s->sh_type == SHT_DYNSYM || + s->sh_type == SHT_STRTAB || + s->sh_type == SHT_HASH) { + if (k != 1) + continue; + } else if (s->sh_type == SHT_RELX) { + if (k != 2) + continue; + } else if (s->sh_type == SHT_NOBITS) { + if (k != 4) + continue; + } else { + if (k != 3) + continue; + } + section_order[sh_order_index++] = i; + + /* section matches: we align it and add its size */ + tmp = addr; + addr = (addr + s->sh_addralign - 1) & + ~(s->sh_addralign - 1); + file_offset += addr - tmp; + s->sh_offset = file_offset; + s->sh_addr = addr; + + /* update program header infos */ + if (ph->p_offset == 0) { + ph->p_offset = file_offset; + ph->p_vaddr = addr; + ph->p_paddr = ph->p_vaddr; + } + /* update dynamic relocation infos */ + if (s->sh_type == SHT_RELX) { + if (rel_size == 0) + rel_addr = addr; + rel_size += 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; + ph++; + if (j == 0) { + if (s1->output_format == TCC_OUTPUT_FORMAT_ELF) { + /* if in the middle of a page, we duplicate the page in + memory so that one copy is RX and the other is RW */ + if ((addr & (ELF_PAGE_SIZE - 1)) != 0) + addr += ELF_PAGE_SIZE; + } else { + addr = (addr + ELF_PAGE_SIZE - 1) & ~(ELF_PAGE_SIZE - 1); + file_offset = (file_offset + ELF_PAGE_SIZE - 1) & + ~(ELF_PAGE_SIZE - 1); + } + } + } + + /* if interpreter, then add corresponing program header */ + if (interp) { + ph = &phdr[0]; + + ph->p_type = PT_INTERP; + ph->p_offset = interp->sh_offset; + ph->p_vaddr = interp->sh_addr; + ph->p_paddr = ph->p_vaddr; + ph->p_filesz = interp->sh_size; + ph->p_memsz = interp->sh_size; + ph->p_flags = PF_R; + ph->p_align = interp->sh_addralign; + } + + /* if dynamic section, then add corresponing program header */ + if (dynamic) { + ElfW(Sym) *sym_end; + + ph = &phdr[phnum - 1]; + + ph->p_type = PT_DYNAMIC; + ph->p_offset = dynamic->sh_offset; + ph->p_vaddr = dynamic->sh_addr; + ph->p_paddr = ph->p_vaddr; + ph->p_filesz = dynamic->sh_size; + ph->p_memsz = dynamic->sh_size; + ph->p_flags = PF_R | PF_W; + ph->p_align = dynamic->sh_addralign; + + /* put GOT dynamic section address */ + put32(s1->got->data, dynamic->sh_addr); + + /* relocate the PLT */ + if (file_type == TCC_OUTPUT_EXE +#if defined(TCC_OUTPUT_DLL_WITH_PLT) + || file_type == TCC_OUTPUT_DLL +#endif + ) { + uint8_t *p, *p_end; + + p = s1->plt->data; + p_end = p + s1->plt->data_offset; + if (p < p_end) { +#if defined(TCC_TARGET_I386) + put32(p + 2, get32(p + 2) + s1->got->sh_addr); + put32(p + 8, get32(p + 8) + s1->got->sh_addr); + p += 16; + while (p < p_end) { + put32(p + 2, get32(p + 2) + s1->got->sh_addr); + p += 16; + } +#elif defined(TCC_TARGET_X86_64) + int x = s1->got->sh_addr - s1->plt->sh_addr - 6; + put32(p + 2, get32(p + 2) + x); + put32(p + 8, get32(p + 8) + x - 6); + p += 16; + while (p < p_end) { + put32(p + 2, get32(p + 2) + x + s1->plt->data - p); + p += 16; + } +#elif defined(TCC_TARGET_ARM) + int x; + x=s1->got->sh_addr - s1->plt->sh_addr - 12; + p +=16; + while (p < p_end) { + put32(p + 12, x + get32(p + 12) + s1->plt->data - p); + p += 16; + } +#elif defined(TCC_TARGET_C67) + /* XXX: TODO */ +#else +#error unsupported CPU +#endif + } + } + + /* relocate symbols in .dynsym */ + sym_end = (ElfW(Sym) *)(s1->dynsym->data + s1->dynsym->data_offset); + for(sym = (ElfW(Sym) *)s1->dynsym->data + 1; + sym < sym_end; + sym++) { + if (sym->st_shndx == SHN_UNDEF) { + /* relocate to the PLT if the symbol corresponds + to a PLT entry */ + if (sym->st_value) + sym->st_value += s1->plt->sh_addr; + } else if (sym->st_shndx < SHN_LORESERVE) { + /* do symbol relocation */ + sym->st_value += s1->sections[sym->st_shndx]->sh_addr; + } + } + + /* put dynamic section entries */ + dynamic->data_offset = saved_dynamic_data_offset; + put_dt(dynamic, DT_HASH, s1->dynsym->hash->sh_addr); + put_dt(dynamic, DT_STRTAB, dynstr->sh_addr); + put_dt(dynamic, DT_SYMTAB, s1->dynsym->sh_addr); + put_dt(dynamic, DT_STRSZ, dynstr->data_offset); + put_dt(dynamic, DT_SYMENT, sizeof(ElfW(Sym))); +#ifdef TCC_TARGET_X86_64 + put_dt(dynamic, DT_RELA, rel_addr); + put_dt(dynamic, DT_RELASZ, rel_size); + put_dt(dynamic, DT_RELAENT, sizeof(ElfW_Rel)); +#else + put_dt(dynamic, DT_REL, rel_addr); + put_dt(dynamic, DT_RELSZ, rel_size); + put_dt(dynamic, DT_RELENT, sizeof(ElfW_Rel)); +#endif + if (s1->do_debug) + put_dt(dynamic, DT_DEBUG, 0); + put_dt(dynamic, DT_NULL, 0); + } + + ehdr.e_phentsize = sizeof(ElfW(Phdr)); + ehdr.e_phnum = phnum; + ehdr.e_phoff = sizeof(ElfW(Ehdr)); + } + + /* all other sections come after */ + for(i = 1; i < s1->nb_sections; i++) { + s = s1->sections[i]; + if (phnum > 0 && (s->sh_flags & SHF_ALLOC)) + continue; + section_order[sh_order_index++] = i; + + file_offset = (file_offset + s->sh_addralign - 1) & + ~(s->sh_addralign - 1); + s->sh_offset = file_offset; + if (s->sh_type != SHT_NOBITS) + file_offset += s->sh_size; + } + + /* if building executable or DLL, then relocate each section + except the GOT which is already relocated */ + if (file_type != TCC_OUTPUT_OBJ) { + relocate_syms(s1, 0); + + if (s1->nb_errors != 0) { + fail: + ret = -1; + goto the_end; + } + + /* relocate sections */ + /* XXX: ignore sections with allocated relocations ? */ + for(i = 1; i < s1->nb_sections; i++) { + s = s1->sections[i]; + if (s->reloc && s != s1->got && (s->sh_flags & SHF_ALLOC)) //gr + relocate_section(s1, s); + } + + /* relocate relocation entries if the relocation tables are + allocated in the executable */ + for(i = 1; i < s1->nb_sections; i++) { + s = s1->sections[i]; + if ((s->sh_flags & SHF_ALLOC) && + s->sh_type == SHT_RELX) { + relocate_rel(s1, s); + } + } + + /* get entry point address */ + if (file_type == TCC_OUTPUT_EXE) + ehdr.e_entry = (unsigned long)tcc_get_symbol_err(s1, "_start"); + else + ehdr.e_entry = text_section->sh_addr; /* XXX: is it correct ? */ + } + + /* write elf file */ + if (file_type == TCC_OUTPUT_OBJ) + mode = 0666; + else + mode = 0777; + fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, mode); + if (fd < 0) { + error_noabort("could not write '%s'", filename); + goto fail; + } + f = fdopen(fd, "wb"); + 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) { + sort_syms(s1, symtab_section); + + /* 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] = TCC_ELFCLASS; + ehdr.e_ident[5] = ELFDATA2LSB; + ehdr.e_ident[6] = EV_CURRENT; +#ifdef __FreeBSD__ + ehdr.e_ident[EI_OSABI] = ELFOSABI_FREEBSD; +#endif +#ifdef TCC_TARGET_ARM +#ifdef TCC_ARM_EABI + ehdr.e_ident[EI_OSABI] = 0; + ehdr.e_flags = 4 << 24; +#else + ehdr.e_ident[EI_OSABI] = ELFOSABI_ARM; +#endif +#endif + switch(file_type) { + case TCC_OUTPUT_DLL: + ehdr.e_type = ET_DYN; + break; + case TCC_OUTPUT_OBJ: + ehdr.e_type = ET_REL; + break; + case TCC_OUTPUT_EXE: + default: + ehdr.e_type = ET_EXEC; + break; + } + 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); + fwrite(phdr, 1, phnum * sizeof(ElfW(Phdr)), f); + offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr)); + + for(i=1;i<s1->nb_sections;i++) { + s = s1->sections[section_order[i]]; + if (s->sh_type != SHT_NOBITS) { + while (offset < s->sh_offset) { + fputc(0, f); + offset++; + } + size = s->sh_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<s1->nb_sections;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); + } + } else { + tcc_output_binary(s1, f, section_order); + } + fclose(f); + + ret = 0; + the_end: + tcc_free(s1->symtab_to_dynsym); + tcc_free(section_order); + tcc_free(phdr); + tcc_free(s1->got_offsets); + return ret; +} + +int tcc_output_file(TCCState *s, const char *filename) +{ + int ret; +#ifdef TCC_TARGET_PE + if (s->output_type != TCC_OUTPUT_OBJ) { + ret = pe_output_file(s, filename); + } else +#endif + { + ret = elf_output_file(s, filename); + } + return ret; +} + +static void *load_data(int fd, unsigned long file_offset, unsigned long size) +{ + void *data; + + data = tcc_malloc(size); + lseek(fd, file_offset, SEEK_SET); + 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; + +/* load an object file and merge it with current files */ +/* XXX: handle correctly stab (debug) info */ +static int tcc_load_object_file(TCCState *s1, + int fd, unsigned long file_offset) +{ + ElfW(Ehdr) ehdr; + ElfW(Shdr) *shdr, *sh; + int size, i, j, offset, offseti, nb_syms, sym_index, ret; + unsigned char *strsec, *strtab; + int *old_to_new_syms; + char *sh_name, *name; + SectionMergeInfo *sm_table, *sm; + ElfW(Sym) *sym, *symtab; + ElfW_Rel *rel, *rel_end; + Section *s; + + int stab_index; + int stabstr_index; + + stab_index = stabstr_index = 0; + + if (read(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr)) + goto fail1; + if (ehdr.e_ident[0] != ELFMAG0 || + ehdr.e_ident[1] != ELFMAG1 || + ehdr.e_ident[2] != ELFMAG2 || + ehdr.e_ident[3] != ELFMAG3) + goto fail1; + /* test if object file */ + if (ehdr.e_type != ET_REL) + goto fail1; + /* test CPU specific stuff */ + if (ehdr.e_ident[5] != ELFDATA2LSB || + ehdr.e_machine != EM_TCC_TARGET) { + fail1: + error_noabort("invalid object file"); + return -1; + } + /* 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; + for(i = 1; i < ehdr.e_shnum; i++) { + sh = &shdr[i]; + if (sh->sh_type == SHT_SYMTAB) { + if (symtab) { + error_noabort("object must contain only one symtab"); + fail: + ret = -1; + 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); + } + } + + /* 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]; + sh_name = strsec + sh->sh_name; + /* ignore sections types we do not handle */ + if (sh->sh_type != SHT_PROGBITS && + sh->sh_type != SHT_RELX && +#ifdef TCC_ARM_EABI + sh->sh_type != SHT_ARM_EXIDX && +#endif + sh->sh_type != SHT_NOBITS && + strcmp(sh_name, ".stabstr") + ) + continue; + 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; + } else { + goto found; + } + } + } + /* not found: create new section */ + s = new_section(s1, sh_name, sh->sh_type, sh->sh_flags); + /* 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) { + error_noabort("invalid section type"); + goto fail; + } + + /* align start of section */ + offset = s->data_offset; + + if (0 == strcmp(sh_name, ".stab")) { + stab_index = i; + goto no_align; + } + if (0 == strcmp(sh_name, ".stabstr")) { + stabstr_index = i; + goto no_align; + } + + size = sh->sh_addralign - 1; + offset = (offset + size) & ~size; + if (sh->sh_addralign > s->sh_addralign) + s->sh_addralign = sh->sh_addralign; + s->data_offset = offset; + no_align: + sm_table[i].offset = 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); + 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) + 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; + } + } + sm = sm_table; + + /* 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 (ELF64_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 = add_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; + switch(s->sh_type) { + case SHT_RELX: + /* take relocation offset information */ + offseti = sm_table[sh->sh_info].offset; + rel_end = (ElfW_Rel *)(s->data + s->data_offset); + for(rel = (ElfW_Rel *)(s->data + offset); + rel < rel_end; + rel++) { + int type; + unsigned sym_index; + /* convert symbol index */ + type = ELF64_R_TYPE(rel->r_info); + sym_index = ELF64_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->link_once) { + invalid_reloc: + error_noabort("Invalid relocation entry [%2d] '%s' @ %.8x", + i, strsec + sh->sh_name, rel->r_offset); + goto fail; + } + rel->r_info = ELF64_R_INFO(sym_index, type); + /* offset the relocation offset */ + rel->r_offset += offseti; + } + 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; +} + +#define ARMAG "!<arch>\012" /* For COFF and a.out archives */ + +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; + +static int get_be32(const uint8_t *b) +{ + return b[3] | (b[2] << 8) | (b[1] << 16) | (b[0] << 24); +} + +/* load only the objects which resolve undefined symbols */ +static int tcc_load_alacarte(TCCState *s1, int fd, int size) +{ + int i, bound, nsyms, sym_index, off, ret; + uint8_t *data; + const char *ar_names, *p; + const uint8_t *ar_index; + ElfW(Sym) *sym; + + data = tcc_malloc(size); + if (read(fd, data, size) != size) + goto fail; + nsyms = get_be32(data); + ar_index = data + 4; + ar_names = ar_index + nsyms * 4; + + do { + bound = 0; + for(p = ar_names, i = 0; i < nsyms; i++, p += strlen(p)+1) { + sym_index = find_elf_sym(symtab_section, p); + if(sym_index) { + sym = &((ElfW(Sym) *)symtab_section->data)[sym_index]; + if(sym->st_shndx == SHN_UNDEF) { + off = get_be32(ar_index + i * 4) + sizeof(ArchiveHeader); +#if 0 + printf("%5d\t%s\t%08x\n", i, p, sym->st_shndx); +#endif + ++bound; + lseek(fd, off, SEEK_SET); + if(tcc_load_object_file(s1, fd, off) < 0) { + fail: + ret = -1; + goto the_end; + } + } + } + } + } while(bound); + ret = 0; + the_end: + tcc_free(data); + return ret; +} + +/* load a '.a' file */ +static int tcc_load_archive(TCCState *s1, int fd) +{ + ArchiveHeader hdr; + char ar_size[11]; + char ar_name[17]; + char magic[8]; + int size, len, i; + unsigned long file_offset; + + /* skip magic which was already checked */ + read(fd, magic, sizeof(magic)); + + for(;;) { + len = read(fd, &hdr, sizeof(hdr)); + if (len == 0) + break; + if (len != sizeof(hdr)) { + error_noabort("invalid archive"); + return -1; + } + memcpy(ar_size, hdr.ar_size, sizeof(hdr.ar_size)); + ar_size[sizeof(hdr.ar_size)] = '\0'; + size = strtol(ar_size, NULL, 0); + memcpy(ar_name, hdr.ar_name, sizeof(hdr.ar_name)); + for(i = sizeof(hdr.ar_name) - 1; i >= 0; i--) { + if (ar_name[i] != ' ') + break; + } + ar_name[i + 1] = '\0'; + // printf("name='%s' size=%d %s\n", ar_name, size, ar_size); + file_offset = lseek(fd, 0, SEEK_CUR); + /* align to even */ + size = (size + 1) & ~1; + if (!strcmp(ar_name, "/")) { + /* coff symbol table : we handle it */ + if(s1->alacarte_link) + return tcc_load_alacarte(s1, fd, size); + } else if (!strcmp(ar_name, "//") || + !strcmp(ar_name, "__.SYMDEF") || + !strcmp(ar_name, "__.SYMDEF/") || + !strcmp(ar_name, "ARFILENAMES/")) { + /* skip symbol table or archive names */ + } else { + if (tcc_load_object_file(s1, fd, file_offset) < 0) + return -1; + } + lseek(fd, file_offset + size, SEEK_SET); + } + return 0; +} + +/* 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) */ +static int tcc_load_dll(TCCState *s1, int fd, const char *filename, int level) +{ + ElfW(Ehdr) ehdr; + ElfW(Shdr) *shdr, *sh, *sh1; + int i, j, nb_syms, nb_dts, sym_bind, ret; + ElfW(Sym) *sym, *dynsym; + ElfW(Dyn) *dt, *dynamic; + unsigned char *dynstr; + const char *name, *soname; + DLLReference *dllref; + + read(fd, &ehdr, sizeof(ehdr)); + + /* test CPU specific stuff */ + if (ehdr.e_ident[5] != ELFDATA2LSB || + ehdr.e_machine != EM_TCC_TARGET) { + error_noabort("bad architecture"); + return -1; + } + + /* 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 */ + 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; + default: + break; + } + } + + /* 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 */ + for(i = 0; i < s1->nb_loaded_dlls; i++) { + dllref = s1->loaded_dlls[i]; + if (!strcmp(soname, dllref->name)) { + /* but update level if needed */ + if (level < dllref->level) + dllref->level = level; + ret = 0; + goto the_end; + } + } + + // printf("loading dll '%s'\n", soname); + + /* add the dll and its level */ + dllref = tcc_mallocz(sizeof(DLLReference) + strlen(soname)); + dllref->level = level; + strcpy(dllref->name, soname); + dynarray_add((void ***)&s1->loaded_dlls, &s1->nb_loaded_dlls, dllref); + + /* add dynamic symbols in dynsym_section */ + for(i = 1, sym = dynsym + 1; i < nb_syms; i++, sym++) { + sym_bind = ELF64_ST_BIND(sym->st_info); + if (sym_bind == STB_LOCAL) + continue; + name = dynstr + sym->st_name; + add_elf_sym(s1->dynsymtab_section, sym->st_value, sym->st_size, + sym->st_info, sym->st_other, sym->st_shndx, name); + } + + /* 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; + for(j = 0; j < s1->nb_loaded_dlls; j++) { + dllref = s1->loaded_dlls[j]; + if (!strcmp(name, dllref->name)) + goto already_loaded; + } + if (tcc_add_dll(s1, name, AFF_REFERENCED_DLL) < 0) { + error_noabort("referenced dll '%s' not found", name); + ret = -1; + goto the_end; + } + already_loaded: + break; + } + } + ret = 0; + the_end: + tcc_free(dynstr); + tcc_free(dynsym); + tcc_free(dynamic); + tcc_free(shdr); + return ret; +} + +#define LD_TOK_NAME 256 +#define LD_TOK_EOF (-1) + +/* return next ld script token */ +static int ld_next(TCCState *s1, char *name, int name_size) +{ + int c; + char *q; + + redo: + switch(ch) { + case ' ': + case '\t': + case '\f': + case '\v': + case '\r': + case '\n': + inp(); + goto redo; + case '/': + minp(); + if (ch == '*') { + file->buf_ptr = parse_comment(file->buf_ptr); + ch = file->buf_ptr[0]; + goto redo; + } else { + q = name; + *q++ = '/'; + goto parse_name; + } + break; + /* 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 '$': + 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; + } + minp(); + } + *q = '\0'; + c = LD_TOK_NAME; + break; + case CH_EOF: + c = LD_TOK_EOF; + break; + default: + c = ch; + inp(); + break; + } +#if 0 + printf("tok=%c %d\n", c, c); + if (c == LD_TOK_NAME) + printf(" name=%s\n", name); +#endif + return c; +} + +static int ld_add_file_list(TCCState *s1, int as_needed) +{ + char filename[1024]; + int t, ret; + + t = ld_next(s1, filename, sizeof(filename)); + if (t != '(') + expect("("); + t = ld_next(s1, filename, sizeof(filename)); + for(;;) { + if (t == LD_TOK_EOF) { + error_noabort("unexpected end of file"); + return -1; + } else if (t == ')') { + break; + } else if (t != LD_TOK_NAME) { + error_noabort("filename expected"); + return -1; + } + if (!strcmp(filename, "AS_NEEDED")) { + ret = ld_add_file_list(s1, 1); + if (ret) + return ret; + } else { + /* TODO: Implement AS_NEEDED support. Ignore it for now */ + if (!as_needed) + tcc_add_file(s1, filename); + } + t = ld_next(s1, filename, sizeof(filename)); + if (t == ',') { + t = ld_next(s1, filename, sizeof(filename)); + } + } + return 0; +} + +/* interpret a subset of GNU ldscripts to handle the dummy libc.so + files */ +static int tcc_load_ldscript(TCCState *s1) +{ + char cmd[64]; + char filename[1024]; + int t, ret; + + ch = file->buf_ptr[0]; + ch = handle_eob(); + 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, 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 != '(') + expect("("); + for(;;) { + t = ld_next(s1, filename, sizeof(filename)); + if (t == LD_TOK_EOF) { + error_noabort("unexpected end of file"); + return -1; + } else if (t == ')') { + break; + } + } + } else { + return -1; + } + } + return 0; +} |