From 4aec2902cabb819e24850c80ddb364b7b4308b7b Mon Sep 17 00:00:00 2001 From: Thomas Preud'homme Date: Wed, 18 Dec 2013 11:17:17 +0800 Subject: [PATCH] Split elf_output_file in smaller functions --- tccelf.c | 1210 ++++++++++++++++++++++++++++++++++---------------------------- 1 file changed, 659 insertions(+), 551 deletions(-) diff --git a/tccelf.c b/tccelf.c index 87b0eaae..66462c2a 100644 --- a/tccelf.c +++ b/tccelf.c @@ -20,6 +20,7 @@ #include "tcc.h" +/* XXX: avoid static variable */ static int new_undef_sym = 0; /* Is there a new undefined sym since last new_undef_sym() */ ST_FUNC int put_elf_str(Section *s, const char *sym) @@ -429,6 +430,7 @@ ST_FUNC void relocate_syms(TCCState *s1, int do_resolve) sh_num = sym->st_shndx; if (sh_num == SHN_UNDEF) { name = strtab_section->data + sym->st_name; + /* Use ld.so to resolve symbol for us (for tcc -run) */ if (do_resolve) { #if defined TCC_IS_NATIVE && !defined _WIN32 void *addr; @@ -504,7 +506,8 @@ static addr_t add_jmp_table(TCCState *s1, int val) #endif #endif /* def TCC_HAS_RUNTIME_PLTGOT */ -/* relocate a given section (CPU dependent) */ +/* relocate a given section (CPU dependent) by applying the relocations + in the associated relocation section */ ST_FUNC void relocate_section(TCCState *s1, Section *s) { Section *sr = s->reloc; @@ -1422,14 +1425,14 @@ ST_FUNC void tcc_add_linker_symbols(TCCState *s1) } static void tcc_output_binary(TCCState *s1, FILE *f, - const int *section_order) + const int *sec_order) { Section *s; int i, offset, size; offset = 0; for(i=1;inb_sections;i++) { - s = s1->sections[section_order[i]]; + s = s1->sections[sec_order[i]]; if (s->sh_type != SHT_NOBITS && (s->sh_flags & SHF_ALLOC)) { while (offset < s->sh_offset) { @@ -1494,6 +1497,7 @@ ST_FUNC void fill_got_entry(TCCState *s1, ElfW_Rel *rel) put32(s1->got->data + offset, sym->st_value & 0xffffffff); } +/* Perform relocation to GOT or PLT entries */ ST_FUNC void fill_got(TCCState *s1) { Section *s; @@ -1509,301 +1513,213 @@ ST_FUNC void fill_got(TCCState *s1) continue; for_each_elem(s, 0, rel, ElfW_Rel) { switch (ELFW(R_TYPE) (rel->r_info)) { +#ifdef TCC_TARGET_X86_64 case R_X86_64_GOT32: case R_X86_64_GOTPCREL: case R_X86_64_PLT32: fill_got_entry(s1, rel); break; +#endif } } } } - -/* output an ELF file */ -/* XXX: suppress unneeded sections */ -static int elf_output_file(TCCState *s1, const char *filename) +/* Bind symbols of executable: resolve undefined symbols from exported symbols + in shared libraries and export non local defined symbols to shared libraries + if -rdynamic switch was given on command line */ +static void bind_exe_dynsyms(TCCState *s1) { - ElfW(Ehdr) ehdr; - FILE *f; - int fd, mode, ret; - int *section_order; - int shnum, i, phnum, file_offset, offset, size, j, sh_order_index, k; - long long tmp; - addr_t 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; - addr_t rel_addr, rel_size; -#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) - addr_t bss_addr, bss_size; -#endif - - 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; - - 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); - } - - /* 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 or STT_GNU_IFUNC - 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 */ - if (file_type == TCC_OUTPUT_EXE) { - for_each_elem(symtab_section, 1, sym, ElfW(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 = 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 */ - put_got_entry(s1, R_JMP_SLOT, esym->st_size, - ELFW(ST_INFO)(STB_GLOBAL,STT_FUNC), - sym - (ElfW(Sym) *)symtab_section->data); - } else if (type == STT_OBJECT) { - unsigned long offset; - ElfW(Sym) *dynsym; - 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); - /* 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; - dynname = 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); - } - } - } else if (s1->rdynamic && - ELFW(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; + const char *name; + int sym_index, index; + ElfW(Sym) *sym, *esym; + int type; - /* now look at unresolved dynamic symbols and export - corresponding symbol */ - for_each_elem(s1->dynsymtab_section, 1, esym, ElfW(Sym)) { - 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 (ELFW(ST_BIND)(esym->st_info) == STB_WEAK) { - /* weak symbols can stay undefined */ - } else { - tcc_warning("undefined dynamic symbol '%s'", name); + /* 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 = 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 */ + put_got_entry(s1, R_JMP_SLOT, esym->st_size, + ELFW(ST_INFO)(STB_GLOBAL,STT_FUNC), + sym - (ElfW(Sym) *)symtab_section->data); + } else if (type == STT_OBJECT) { + unsigned long offset; + ElfW(Sym) *dynsym; + 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); + /* 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 = 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 { - 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_each_elem(symtab_section, 1, sym, ElfW(Sym)) { - if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) { -#if defined(TCC_OUTPUT_DLL_WITH_PLT) - if ((ELFW(ST_TYPE)(sym->st_info) == STT_FUNC || - ELFW(ST_TYPE)(sym->st_info) == STT_GNU_IFUNC) - && sym->st_shndx == SHN_UNDEF) { - int visibility = ELFW(ST_BIND)(sym->st_info); - put_got_entry(s1, R_JMP_SLOT, sym->st_size, - ELFW(ST_INFO)(visibility,STT_FUNC), - sym - (ElfW(Sym) *)symtab_section->data); - } - else if (ELFW(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; - } - } + /* 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); } } + } else if (s1->rdynamic && ELFW(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); + } + } +} - build_got_entries(s1); +/* Bind symbols of libraries: export non local symbols of executable that + resolve undefined symbols of shared libraries */ +static void bind_libs_dynsyms(TCCState *s1) +{ + const char *name; + int sym_index; + ElfW(Sym) *sym, *esym; - /* 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)); + /* now look at unresolved dynamic symbols and export + corresponding symbol */ + for_each_elem(s1->dynsymtab_section, 1, esym, ElfW(Sym)) { + 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 { + /* weak symbols can stay undefined */ + if (ELFW(ST_BIND)(esym->st_info) != STB_WEAK) + tcc_warning("undefined dynamic symbol '%s'", name); } + } + } +} - if (s1->rpath) - put_dt(dynamic, DT_RPATH, put_elf_str(dynstr, s1->rpath)); +/* Export all non local symbols (for shared libraries) */ +static void export_global_syms(TCCState *s1) +{ + int nb_syms, dynindex, index; + const char *name; + ElfW(Sym) *sym; - /* 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); + nb_syms = symtab_section->data_offset / sizeof(ElfW(Sym)); + s1->symtab_to_dynsym = tcc_mallocz(sizeof(int) * nb_syms); + for_each_elem(symtab_section, 1, sym, ElfW(Sym)) { + if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) { +#if defined(TCC_OUTPUT_DLL_WITH_PLT) + int type = ELFW(ST_TYPE)(sym->st_info); + if ((type == STT_FUNC || type == STT_GNU_IFUNC) + && sym->st_shndx == SHN_UNDEF) { + int visibility = ELFW(ST_BIND)(sym->st_info); + put_got_entry(s1, R_JMP_SLOT, sym->st_size, + ELFW(ST_INFO)(visibility, STT_FUNC), + sym - (ElfW(Sym) *) symtab_section->data); + } else if (type == 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; + dynindex = put_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; + s1->symtab_to_dynsym[index] = dynindex; } - - if (s1->symbolic) - put_dt(dynamic, DT_SYMBOLIC, 0); - - /* add necessary space for other entries */ - saved_dynamic_data_offset = dynamic->data_offset; - dynamic->data_offset += sizeof(ElfW(Dyn)) * EXTRA_RELITEMS; - } 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, ""); +/* relocate the PLT: compute addresses and offsets in the PLT now that final + address for PLT and GOT are known (see fill_program_header) */ +static void relocate_plt(TCCState *s1) +{ + uint8_t *p, *p_end; - /* compute number of sections */ - shnum = s1->nb_sections; + 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) { + if (get32(p) == 0x46c04778) /* PLT Thumb stub present */ + p += 4; + 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 + } +} - /* 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; +/* Allocate strings for section names and decide if an unallocated section + should be output. - /* compute number of program headers */ - switch(file_type) { - default: - case TCC_OUTPUT_OBJ: - phnum = 0; - break; - case TCC_OUTPUT_EXE: - if (!s1->static_link) - phnum = 4 + HAVE_PHDR; - else - phnum = 2; - break; - case TCC_OUTPUT_DLL: - phnum = 3; - break; - } + NOTE: the strsec section comes last, so its size is also correct ! */ +static void alloc_sec_names(TCCState *s1, int file_type, Section *strsec) +{ + int i; + Section *s; - /* 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 ! */ + /* Allocate strings for section names */ for(i = 1; i < s1->nb_sections; i++) { s = s1->sections[i]; s->sh_name = put_elf_str(strsec, s->name); @@ -1825,17 +1741,41 @@ static int elf_output_file(TCCState *s1, const char *filename) s->sh_size = s->data_offset; } } +} - /* allocate program segment headers */ - phdr = tcc_mallocz(phnum * sizeof(ElfW(Phdr))); +/* Info to be copied in dynamic section */ +struct dyn_inf { + Section *dynamic; + Section *dynstr; + unsigned long dyn_rel_off; + addr_t rel_addr; + addr_t rel_size; +#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) + addr_t bss_addr; + addr_t bss_size; +#endif +}; + +/* 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, ElfW(Phdr) *phdr, int phnum, + Section *interp, struct dyn_inf *dyninf, + int *sec_order) +{ + int i, j, k, file_type, sh_order_index, file_offset; + long long tmp; + addr_t addr; + ElfW(Phdr) *ph; + Section *s; - if (s1->output_format == TCC_OUTPUT_FORMAT_ELF) { + file_type = s1->output_type; + sh_order_index = 1; + if (s1->output_format == TCC_OUTPUT_FORMAT_ELF) file_offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr)); - } else { + 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; @@ -1855,18 +1795,19 @@ static int elf_output_file(TCCState *s1, const char *filename) addr += (file_offset & (s1->section_align - 1)); } - /* dynamic relocation table information, for .dynamic section */ - rel_size = 0; - rel_addr = 0; - -#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) - bss_addr = bss_size = 0; -#endif - /* leave one program header for the program interpreter */ ph = &phdr[0]; + /* Leave one program headers for the program interpreter and one for + the program header table itself if needed. These are done later as + they require section layout to be done first. */ if (interp) ph += 1 + HAVE_PHDR; + /* dynamic relocation table information, for .dynamic section */ + dyninf->rel_addr = dyninf->rel_size = 0; +#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) + dyninf->bss_addr = dyninf->bss_size = 0; +#endif + for(j = 0; j < 2; j++) { ph->p_type = PT_LOAD; if (j == 0) @@ -1875,8 +1816,10 @@ static int elf_output_file(TCCState *s1, const char *filename) ph->p_flags = PF_R | PF_W; ph->p_align = s1->section_align; - /* we do the following ordering: interp, symbol tables, - relocations, progbits, nobits */ + /* 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 */ /* XXX: do faster and simpler sorting */ for(k = 0; k < 5; k++) { for(i = 1; i < s1->nb_sections; i++) { @@ -1909,7 +1852,7 @@ static int elf_output_file(TCCState *s1, const char *filename) if (k != 3) continue; } - section_order[sh_order_index++] = i; + sec_order[sh_order_index++] = i; /* section matches: we align it and add its size */ tmp = addr; @@ -1929,17 +1872,17 @@ static int elf_output_file(TCCState *s1, const char *filename) if (s->sh_type == SHT_RELX) { #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) if (!strcmp(strsec->data + s->sh_name, ".rel.got")) { - rel_addr = addr; - rel_size += s->sh_size; /* XXX only first rel. */ + dyninf->rel_addr = addr; + dyninf->rel_size += s->sh_size; /* XXX only first rel. */ } if (!strcmp(strsec->data + s->sh_name, ".rel.bss")) { - bss_addr = addr; - bss_size = s->sh_size; /* XXX only first rel. */ + dyninf->bss_addr = addr; + dyninf->bss_size = s->sh_size; /* XXX only first rel. */ } #else - if (rel_size == 0) - rel_addr = addr; - rel_size += s->sh_size; + if (dyninf->rel_size == 0) + dyninf->rel_addr = addr; + dyninf->rel_size += s->sh_size; #endif } addr += s->sh_size; @@ -1963,199 +1906,269 @@ static int elf_output_file(TCCState *s1, const char *filename) } } } + } - /* if interpreter, then add corresponing program header */ - if (interp) { - ph = &phdr[0]; + /* 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; + sec_order[sh_order_index++] = i; -#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) - { - int len = phnum * sizeof(ElfW(Phdr)); - - ph->p_type = PT_PHDR; - ph->p_offset = sizeof(ElfW(Ehdr)); - ph->p_vaddr = interp->sh_addr - len; - ph->p_paddr = ph->p_vaddr; - ph->p_filesz = ph->p_memsz = len; - ph->p_flags = PF_R | PF_X; - ph->p_align = 4; /* interp->sh_addralign; */ - ph++; - } -#endif + 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; + } - 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; - } + return file_offset; +} - /* if dynamic section, then add corresponing program header */ - if (dynamic) { - ph = &phdr[phnum - 1]; +static void fill_unloadable_phdr(ElfW(Phdr) *phdr, int phnum, Section *interp, + Section *dynamic) +{ + ElfW(Phdr) *ph; + + /* if interpreter, then add corresponding program header */ + if (interp) { + ph = &phdr[0]; - ph->p_type = PT_DYNAMIC; - ph->p_offset = dynamic->sh_offset; - ph->p_vaddr = dynamic->sh_addr; + if (HAVE_PHDR) + { + int len = phnum * sizeof(ElfW(Phdr)); + + ph->p_type = PT_PHDR; + ph->p_offset = sizeof(ElfW(Ehdr)); + ph->p_vaddr = interp->sh_addr - len; 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; + ph->p_filesz = ph->p_memsz = len; + ph->p_flags = PF_R | PF_X; + ph->p_align = 4; /* interp->sh_addralign; */ + ph++; + } - /* put GOT dynamic section address */ - put32(s1->got->data, dynamic->sh_addr); + 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; + } - /* 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; + /* if dynamic section, then add corresponding program header */ + if (dynamic) { + 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; + } +} - 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) { - if (get32(p) == 0x46c04778) /* PLT Thumb stub present */ - p += 4; - 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 - } - } +/* 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; - /* relocate symbols in .dynsym */ - for_each_elem(s1->dynsym, 1, sym, ElfW(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; - } - } + dynamic = dyninf->dynamic; - /* 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))); + /* put dynamic section entries */ + dynamic->data_offset = dyninf->dyn_rel_off; + put_dt(dynamic, DT_HASH, s1->dynsym->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))); #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)); + put_dt(dynamic, DT_RELA, dyninf->rel_addr); + put_dt(dynamic, DT_RELASZ, dyninf->rel_size); + put_dt(dynamic, DT_RELAENT, sizeof(ElfW_Rel)); #else #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) - put_dt(dynamic, DT_PLTGOT, s1->got->sh_addr); - put_dt(dynamic, DT_PLTRELSZ, rel_size); - put_dt(dynamic, DT_JMPREL, rel_addr); - put_dt(dynamic, DT_PLTREL, DT_REL); - put_dt(dynamic, DT_REL, bss_addr); - put_dt(dynamic, DT_RELSZ, bss_size); + put_dt(dynamic, DT_PLTGOT, s1->got->sh_addr); + put_dt(dynamic, DT_PLTRELSZ, dyninf->rel_size); + put_dt(dynamic, DT_JMPREL, dyninf->rel_addr); + put_dt(dynamic, DT_PLTREL, DT_REL); + put_dt(dynamic, DT_REL, dyninf->bss_addr); + put_dt(dynamic, DT_RELSZ, dyninf->bss_size); #else - put_dt(dynamic, DT_REL, rel_addr); - put_dt(dynamic, DT_RELSZ, rel_size); - put_dt(dynamic, DT_RELENT, sizeof(ElfW_Rel)); + put_dt(dynamic, DT_REL, dyninf->rel_addr); + put_dt(dynamic, DT_RELSZ, dyninf->rel_size); + put_dt(dynamic, DT_RELENT, sizeof(ElfW_Rel)); #endif #endif - if (s1->do_debug) - put_dt(dynamic, DT_DEBUG, 0); - put_dt(dynamic, DT_NULL, 0); - } + 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)); - } +/* Relocate remaining sections and symbols (that is those not related to + dynamic linking) */ +static int final_sections_reloc(TCCState *s1) +{ + int i; + Section *s; - /* all other sections come after */ + relocate_syms(s1, 0); + + if (s1->nb_errors != 0) + return -1; + + /* relocate sections */ + /* XXX: ignore sections with allocated relocations ? */ 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; + if (s->reloc && s != s1->got) + relocate_section(s1, s); + } - 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; + /* 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); + } } + return 0; +} - /* 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); +/* Create an ELF file on disk. + This function handle ELF specific layout requirements */ +static void 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; - if (s1->nb_errors != 0) { - fail: - ret = -1; - goto the_end; - } + file_type = s1->output_type; + shnum = s1->nb_sections; - /* 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) - relocate_section(s1, s); - } + memset(&ehdr, 0, sizeof(ehdr)); + + if (phnum > 0) { + ehdr.e_phentsize = sizeof(ElfW(Phdr)); + ehdr.e_phnum = phnum; + ehdr.e_phoff = sizeof(ElfW(Ehdr)); + } - /* 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); + /* 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 defined(__FreeBSD__) || defined(__FreeBSD_kernel__) + 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 = EF_ARM_EABI_VER4; + if (file_type == TCC_OUTPUT_EXE || file_type == TCC_OUTPUT_DLL) + ehdr.e_flags |= EF_ARM_HASENTRY; + if (s1->float_abi == ARM_HARD_FLOAT) + ehdr.e_flags |= EF_ARM_VFP_FLOAT; + else + ehdr.e_flags |= EF_ARM_SOFT_FLOAT; +#else + ehdr.e_ident[EI_OSABI] = ELFOSABI_ARM; +#endif +#endif + switch(file_type) { + default: + case TCC_OUTPUT_EXE: + ehdr.e_type = ET_EXEC; + ehdr.e_entry = get_elf_sym_addr(s1, "_start", 1); + break; + case TCC_OUTPUT_DLL: + ehdr.e_type = ET_DYN; + ehdr.e_entry = text_section->sh_addr; /* XXX: is it correct ? */ + break; + case TCC_OUTPUT_OBJ: + ehdr.e_type = ET_REL; + 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)); + + sort_syms(s1, symtab_section); + for(i = 1; i < s1->nb_sections; i++) { + s = s1->sections[sec_order[i]]; + if (s->sh_type != SHT_NOBITS) { + if (s->sh_type == SHT_DYNSYM) + patch_dynsym_undef(s1, s); + while (offset < s->sh_offset) { + fputc(0, f); + offset++; } + size = s->sh_size; + fwrite(s->data, 1, size, f); + offset += size; } + } - /* get entry point address */ - if (file_type == TCC_OUTPUT_EXE) - ehdr.e_entry = get_elf_sym_addr(s1, "_start", 1); - else - ehdr.e_entry = text_section->sh_addr; /* XXX: is it correct ? */ + /* output section headers */ + while (offset < ehdr.e_shoff) { + fputc(0, f); + offset++; } - if (file_type == TCC_OUTPUT_EXE && s1->static_link) - fill_got(s1); - /* write elf file */ + 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); + } +} + +/* 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; + FILE *f; + + file_type = s1->output_type; if (file_type == TCC_OUTPUT_OBJ) mode = 0666; else @@ -2164,121 +2177,218 @@ static int elf_output_file(TCCState *s1, const char *filename) fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, mode); if (fd < 0) { tcc_error_noabort("could not write '%s'", filename); - goto fail; + return -1; } f = fdopen(fd, "wb"); if (s1->verbose) printf("<- %s\n", filename); #ifdef TCC_TARGET_COFF - if (s1->output_format == TCC_OUTPUT_FORMAT_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] = ELFCLASSW; - ehdr.e_ident[5] = ELFDATA2LSB; - ehdr.e_ident[6] = EV_CURRENT; -#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) - 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 = EF_ARM_EABI_VER4; - if (file_type == TCC_OUTPUT_EXE || file_type == TCC_OUTPUT_DLL) - ehdr.e_flags |= EF_ARM_HASENTRY; - if (s1->float_abi == ARM_HARD_FLOAT) - ehdr.e_flags |= EF_ARM_VFP_FLOAT; - else - ehdr.e_flags |= EF_ARM_SOFT_FLOAT; -#else - ehdr.e_ident[EI_OSABI] = ELFOSABI_ARM; -#endif + else #endif - switch(file_type) { - default: - case TCC_OUTPUT_EXE: - ehdr.e_type = ET_EXEC; - break; - case TCC_OUTPUT_DLL: - ehdr.e_type = ET_DYN; - break; - case TCC_OUTPUT_OBJ: - ehdr.e_type = ET_REL; - 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;inb_sections;i++) { - s = s1->sections[section_order[i]]; - if (s->sh_type != SHT_NOBITS) { - if (s->sh_type == SHT_DYNSYM) - patch_dynsym_undef(s1, s); - while (offset < s->sh_offset) { - fputc(0, f); - offset++; + if (s1->output_format == TCC_OUTPUT_FORMAT_ELF) + tcc_output_elf(s1, f, phnum, phdr, file_offset, sec_order); + else + tcc_output_binary(s1, f, sec_order); + fclose(f); + + return 0; +} + +/* Output an elf, coff or binary file */ +/* XXX: suppress unneeded sections */ +static int elf_output_file(TCCState *s1, const char *filename) +{ + int i, ret, phnum, shnum, file_type, file_offset, *sec_order; + struct dyn_inf dyninf; + ElfW(Phdr) *phdr; + ElfW(Sym) *sym; + Section *strsec, *interp, *dynamic, *dynstr; + + file_type = s1->output_type; + s1->nb_errors = 0; + + /* if linking, also link in runtime libraries (libc, libgcc, etc.) */ + if (file_type != TCC_OUTPUT_OBJ) { + tcc_add_runtime(s1); + } + + phdr = NULL; + sec_order = NULL; + interp = dynamic = dynstr = NULL; /* avoid warning */ + dyninf.dyn_rel_off = 0; /* avoid warning */ + + if (file_type != TCC_OUTPUT_OBJ) { + relocate_common_syms(); + + tcc_add_linker_symbols(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); + } + + /* 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); + + if (file_type == TCC_OUTPUT_EXE) { + bind_exe_dynsyms(s1); + + if (s1->nb_errors) { + ret = -1; + goto the_end; } - size = s->sh_size; - fwrite(s->data, 1, size, f); - offset += size; + + bind_libs_dynsyms(s1); + } else /* shared library case: simply export all global symbols */ + export_global_syms(s1); + + 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)); } - } - /* output section headers */ - while (offset < ehdr.e_shoff) { - fputc(0, f); - offset++; + if (s1->rpath) + put_dt(dynamic, DT_RPATH, put_elf_str(dynstr, s1->rpath)); + + /* 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); + } + + if (s1->symbolic) + put_dt(dynamic, DT_SYMBOLIC, 0); + + /* add necessary space for other entries */ + dyninf.dyn_rel_off = dynamic->data_offset; + dynamic->data_offset += sizeof(ElfW(Dyn)) * EXTRA_RELITEMS; + } else { + /* still need to build got entries in case of static link */ + build_got_entries(s1); } + } - for(i=0;inb_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; + /* 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 */ + sec_order = tcc_malloc(sizeof(int) * shnum); + sec_order[0] = 0; + + /* compute number of program headers */ + switch(file_type) { + default: + case TCC_OUTPUT_OBJ: + phnum = 0; + break; + case TCC_OUTPUT_EXE: + if (!s1->static_link) + phnum = 4 + HAVE_PHDR; + else + phnum = 2; + break; + case TCC_OUTPUT_DLL: + phnum = 3; + break; + } + + /* Allocate strings for section names */ + alloc_sec_names(s1, file_type, strsec); + + /* allocate program segment headers */ + phdr = tcc_mallocz(phnum * sizeof(ElfW(Phdr))); + + /* compute section to program header mapping */ + file_offset = layout_sections(s1, phdr, phnum, interp, &dyninf, sec_order); + + /* Fill remaining program header and finalize relocation related to dynamic + linking. */ + if (phnum > 0) { + fill_unloadable_phdr(phdr, phnum, interp, dynamic); + if (dynamic) { + dyninf.dynamic = dynamic; + dyninf.dynstr = dynstr; + + fill_dynamic(s1, &dyninf); + + /* put in GOT the dynamic section address and relocate PLT */ + put32(s1->got->data, dynamic->sh_addr); + if (file_type == TCC_OUTPUT_EXE +#if defined(TCC_OUTPUT_DLL_WITH_PLT) + || file_type == TCC_OUTPUT_DLL +#endif + ) + relocate_plt(s1); + + /* relocate symbols in .dynsym now that final addresses are known */ + for_each_elem(s1->dynsym, 1, sym, ElfW(Sym)) { + /* relocate to PLT if symbol corresponds to a PLT entry */ + if (sym->st_shndx == SHN_UNDEF) { + 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; + } } - fwrite(sh, 1, sizeof(ElfW(Shdr)), f); } - } else { - tcc_output_binary(s1, f, section_order); } - fclose(f); - ret = 0; + /* if building executable or DLL, then relocate each section + except the GOT which is already relocated */ + if (file_type != TCC_OUTPUT_OBJ) { + ret = final_sections_reloc(s1); + if (ret) + goto the_end; + } + + /* Perform relocation to GOT or PLT entries */ + if (file_type == TCC_OUTPUT_EXE && s1->static_link) + fill_got(s1); + + /* Create the ELF file with name 'filename' */ + ret = tcc_write_elf_file(s1, filename, phnum, phdr, file_offset, sec_order); the_end: tcc_free(s1->symtab_to_dynsym); - tcc_free(section_order); + tcc_free(sec_order); tcc_free(phdr); tcc_free(s1->sym_attrs); return ret; @@ -2292,9 +2402,7 @@ LIBTCCAPI int tcc_output_file(TCCState *s, const char *filename) ret = pe_output_file(s, filename); } else #endif - { ret = elf_output_file(s, filename); - } return ret; } @@ -2579,8 +2687,8 @@ ST_FUNC int tcc_load_object_file(TCCState *s1, 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 0 of the got offset of a - symbol to indicate such a case. */ + 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) alloc_sym_attr(s1, sym_index)->plt_thumb_stub = 1; #endif -- 2.11.4.GIT