From a8d6f8bf30c07edb775e56889f568ca20240bedf Mon Sep 17 00:00:00 2001 From: lemon Date: Tue, 17 Mar 2026 13:22:00 +0100 Subject: REFACTOR: move sources to src/ --- obj/elf.c | 572 -------------------------------------------------------------- 1 file changed, 572 deletions(-) delete mode 100644 obj/elf.c (limited to 'obj/elf.c') diff --git a/obj/elf.c b/obj/elf.c deleted file mode 100644 index 5044e56..0000000 --- a/obj/elf.c +++ /dev/null @@ -1,572 +0,0 @@ -#include "elf.h" -#include "obj.h" -#include "../ir/ir.h" /* mctarg */ -#include "../endian.h" -#include -#include /* qsort */ - -static union { - ELF_HDRIDENT; - struct elf32hdr h32; - struct elf64hdr h64; -} hdr; -static vec_of(uchar) strs; -struct sym { - uint name; - uchar bind : 4, - type : 4; - ushort shndx; - uvlong value, - size; -}; -static vec_of(struct sym) symtab; -static pmap_of(ushort) symht; -static uint ntextrel, nrodatarel, ndatarel; -struct reloc { - uchar section; - ushort kind; - uint off; - vlong addend; - union { - uint symidx; - internstr symname; - }; -}; -static vec_of(struct reloc) relocs; - -#define O objout - -void -elfinit(void) -{ - memcpy(hdr.i_mag, ELFMAG, 4); - hdr.i_class = ELFCLASS32 + targ_64bit; - hdr.i_data = ELFDATA2LSB + targ_bigendian; - hdr.i_version = ELFVERSION; - hdr.i_osabi = ELFOSABI_SYSV; - hdr.i_abiversion = 0; - hdr.h32.type = ET_REL; - switch (target.arch) { - default: assert(!"arch?"); - case ISx86_64: hdr.h32.machine = EM_X86_64; break; - case ISaarch64: hdr.h32.machine = EM_ARM64; break; - } - hdr.h32.version = ELFVERSION; - if (targ_64bit) { - hdr.h64.ehsize = sizeof(struct elf64hdr); - hdr.h64.shentsize = sizeof(struct elf64shdr); - } else { - hdr.h32.ehsize = sizeof(struct elf32hdr); - hdr.h32.shentsize = sizeof(struct elf32shdr); - } - vinit(&strs, NULL, 4<<10); - vpush(&symtab, ((struct sym){0})); - vpush(&symtab, ((struct sym){ .type = STT_FILE, .shndx = SHN_ABS})); -} - -uint -str2idx(const char *s) -{ - static pmap_of(uint) ht; - uint *p, i; - - if (!ht.v) pmap_init(&ht, 1<<8); - if ((p = pmap_get(&ht, s))) return *p; - if (!strs.n) vpush(&strs, 0); - i = strs.n; - vpushn(&strs, s, strlen(s)+1); - pmap_set(&ht, s, i); - return i; -} - -static struct sym * -findsym(internstr s) -{ - ushort *idx = pmap_get(&symht, s); - return idx ? &symtab.p[*idx] : NULL; -} - -enum { - TEXT_SHNDX = 1, - RODATA_SHNDX = 2, - DATA_SHNDX = 3, - BSS_SHNDX = 4, -}; - -static const char sect2ndx[] = { - [Snone] = SHN_UND, - [Stext] = TEXT_SHNDX, [Srodata] = RODATA_SHNDX, - [Sdata] = DATA_SHNDX, [Sbss] = BSS_SHNDX, -}, shndx2sect[] = { - [SHN_UND] = Snone, - [TEXT_SHNDX] = Stext, [RODATA_SHNDX] = Srodata, - [DATA_SHNDX] = Sdata, [BSS_SHNDX] = Sbss, -}; - -enum section -elfhassym(internstr nam, uint *value) -{ - struct sym *sym = findsym(nam); - if (sym) { - if (value) *value = sym->value; - return shndx2sect[sym->shndx]; - } - return Snone; -} - -void -elfaddsym(internstr nam, int info, enum section sect, uvlong value, uvlong size) -{ - struct sym *sym = findsym(nam), sym0; - if (!sym) { - sym = &sym0; - sym->name = str2idx(&nam->c); - } - sym->bind = info >> 4; - sym->type = info & 0xF; - sym->shndx = sect2ndx[sect]; - sym->value = value; - sym->size = size; - if (sym == &sym0) { - assert(symtab.n < 1<<16); - pmap_set(&symht, nam, symtab.n); - vpush(&symtab, sym0); - } -} - -static const ushort relktab[][NRELOCKIND] = { - [ISx86_64] = { - [REL_ABS64] = 1, /* R_X86_64_64 */ - [REL_ABS32] = 10, /* R_X86_64_32 */ - [REL_ABS32S] = 11, /* R_X86_64_32S */ - [REL_PCREL32] = 2, /* R_X86_64_PC32 */ - [REL_PLT32] = 4, /* R_X86_64_PLT32 */ - [REL_GOTPCRELX] = 41, /* R_X86_64_GOTPCRELX */ - [REL_GOTPCRELX_REX] = 42, /* R_X86_64_REX_GOTPCRELX */ - }, - [ISaarch64] = { - [REL_ABS64] = 257, /* R_AARCH64_ABS64 */ - [REL_ABS32] = 258, /* R_AARCH64_ABS32 */ - [REL_ABS32S] = 258, /* R_AARCH64_ABS32S */ - [REL_PCREL32] = 261, /* R_AARCH64_PREL2 */ - [REL_PLT32] = 314, /* R_AARCH64_PLT32 */ - [REL_CALL26] = 283, /* R_AARCH64_CALL26 */ - [REL_LD_PREL_LO19] = 273, /* R_AARCH64_LD_PREL_LO19 */ - [REL_ADR_PREL_LO21] = 274, /* R_AARCH64_ADR_PREL_LO21 */ - [REL_ADR_PREL_PG_HI21] = 276, /* R_AARCH64_ADR_PREL_PG_HI21_NC */ - [REL_ADD_ABS_LO12_NC] = 277, /* R_AARCH64_ADD_ABS_LO12_NC */ - - } -}; - -void -elfreloc(internstr sym, enum relockind kind, enum section section, uint off, vlong addend) -{ - switch (section) { - default: assert(0); - case Stext: ++ntextrel; break; - case Srodata: ++nrodatarel; break; - case Sdata: ++ndatarel; break; - } - assert(kind < NRELOCKIND); - vpush(&relocs, ((struct reloc) { section, relktab[target.arch][kind], off, addend, .symname = sym })); -} - -static void -elf64puthdr(struct wbuf *out, struct elf64hdr *hdr) -{ - if (!hostntarg_sameendian()) { - hdr->type = bswap16(hdr->type); - hdr->machine = bswap16(hdr->machine); - hdr->version = bswap32(hdr->version); - hdr->entry = bswap64(hdr->entry); - hdr->phoff = bswap64(hdr->phoff); - hdr->shoff = bswap64(hdr->shoff); - hdr->flags = bswap32(hdr->flags); - hdr->ehsize = bswap16(hdr->ehsize); - hdr->phentsize = bswap16(hdr->phentsize); - hdr->phnum = bswap16(hdr->phnum); - hdr->shentsize = bswap16(hdr->shentsize); - hdr->shnum = bswap16(hdr->shnum); - hdr->shstrndx = bswap16(hdr->shstrndx); - } - iowrite(out, hdr, sizeof *hdr); -} - -static void -elf32puthdr(struct wbuf *out, struct elf32hdr *hdr) -{ - if (!hostntarg_sameendian()) { - hdr->type = bswap16(hdr->type); - hdr->machine = bswap16(hdr->machine); - hdr->version = bswap32(hdr->version); - hdr->entry = bswap32(hdr->entry); - hdr->phoff = bswap32(hdr->phoff); - hdr->shoff = bswap32(hdr->shoff); - hdr->flags = bswap32(hdr->flags); - hdr->ehsize = bswap16(hdr->ehsize); - hdr->phentsize = bswap16(hdr->phentsize); - hdr->phnum = bswap16(hdr->phnum); - hdr->shentsize = bswap16(hdr->shentsize); - hdr->shnum = bswap16(hdr->shnum); - hdr->shstrndx = bswap16(hdr->shstrndx); - } - iowrite(out, hdr, sizeof *hdr); -} - -static void -elf64putshdr(struct wbuf *out, struct elf64shdr *shdr) -{ - if (!hostntarg_sameendian()) { - shdr->name = bswap32(shdr->name); - shdr->type = bswap32(shdr->type); - shdr->flags = bswap64(shdr->flags); - shdr->addr = bswap64(shdr->addr); - shdr->offset = bswap64(shdr->offset); - shdr->size = bswap64(shdr->size); - shdr->link = bswap32(shdr->link); - shdr->info = bswap32(shdr->info); - shdr->addralign = bswap64(shdr->addralign); - shdr->entsize = bswap64(shdr->entsize); - } - iowrite(out, shdr, sizeof *shdr); -} - -static void -elf32putshdr(struct wbuf *out, struct elf32shdr *shdr) -{ - if (!hostntarg_sameendian()) { - shdr->name = bswap32(shdr->name); - shdr->type = bswap32(shdr->type); - shdr->flags = bswap32(shdr->flags); - shdr->addr = bswap32(shdr->addr); - shdr->offset = bswap32(shdr->offset); - shdr->size = bswap32(shdr->size); - shdr->link = bswap32(shdr->link); - shdr->info = bswap32(shdr->info); - shdr->addralign = bswap32(shdr->addralign); - shdr->entsize = bswap32(shdr->entsize); - } - iowrite(out, shdr, sizeof *shdr); -} - -static void -elf64putsym(struct wbuf *out, struct elf64sym *sym) -{ - if (!hostntarg_sameendian()) { - sym->name = bswap32(sym->name); - sym->shndx = bswap16(sym->shndx); - sym->value = bswap64(sym->value); - sym->size = bswap64(sym->size); - } - iowrite(out, sym, sizeof *sym); -} - -static void -elf32putsym(struct wbuf *out, struct elf32sym *sym) -{ - if (!hostntarg_sameendian()) { - sym->name = bswap32(sym->name); - sym->value = bswap32(sym->value); - sym->size = bswap32(sym->size); - sym->shndx = bswap16(sym->shndx); - } - iowrite(out, sym, sizeof *sym); -} - -static void -putsym(struct wbuf *out, const struct sym *sym) -{ - if (targ_64bit) { - elf64putsym(out, &(struct elf64sym) { - sym->name, .info = ELF_S_INFO(sym->bind, sym->type), - .shndx = sym->shndx, .value = sym->value, .size = sym->size }); - } else { - elf32putsym(out, &(struct elf32sym) { - sym->name, .info = ELF_S_INFO(sym->bind, sym->type), - .shndx = sym->shndx, .value = sym->value, .size = sym->size }); - } -} - -static void -elf64putrel(struct wbuf *out, struct elf64rel *rel) -{ - if (!hostntarg_sameendian()) { - rel->offset = bswap64(rel->offset); - rel->info = bswap64(rel->info); - } - iowrite(out, rel, sizeof *rel); -} - -static void -elf32putrel(struct wbuf *out, struct elf32rel *rel) -{ - if (!hostntarg_sameendian()) { - rel->offset = bswap32(rel->offset); - rel->info = bswap32(rel->info); - } - iowrite(out, rel, sizeof *rel); -} - -static void -elf64putrela(struct wbuf *out, struct elf64rela *rel) -{ - if (!hostntarg_sameendian()) { - rel->offset = bswap64(rel->offset); - rel->info = bswap64(rel->info); - rel->addend = bswap64(rel->addend); - } - iowrite(out, rel, sizeof *rel); -} - -static void -elf32putrela(struct wbuf *out, struct elf32rela *rel) -{ - if (!hostntarg_sameendian()) { - rel->offset = bswap32(rel->offset); - rel->info = bswap32(rel->info); - rel->addend = bswap32(rel->addend); - } - iowrite(out, rel, sizeof *rel); -} - -static void -putreloc(struct wbuf *out, const struct reloc *rel, bool userela) -{ - if (userela) { - if (targ_64bit) { - elf64putrela(out, &(struct elf64rela) { - rel->off, ELF64_R_INFO(rel->symidx, rel->kind), rel->addend }); - } else { - elf32putrela(out, &(struct elf32rela) { - rel->off, ELF32_R_INFO(rel->symidx, rel->kind), rel->addend }); - } - } else { - if (targ_64bit) { - elf64putrel(out, &(struct elf64rel) { - rel->off, ELF64_R_INFO(rel->symidx, rel->kind) }); - } else { - elf32putrel(out, &(struct elf32rel) { - rel->off, ELF32_R_INFO(rel->symidx, rel->kind) }); - } - } -} - -/* ensure .symtab entries are ordered like this: - * (0. zero entry: NOTYPE LOCAL UND) - * (1. file: FILE LOCAL ABS "...") - * 2. locals - * 3. defined globals - * 4. undefined globals - */ -static int -symcmp(const void *aa, const void *bb) -{ - const ushort *a = aa, *b = bb; - const struct sym *l = &symtab.p[*a], *r = &symtab.p[*b]; - int tmp; - if ((tmp = l->bind - r->bind)) return tmp; /* locals prio */ - if ((tmp = r->shndx - l->shndx)) return tmp; /* section prio (real sections > SHN_UND) */ - return l->name - r->name; -} - -static void -wordalign(struct wbuf *out, int align) -{ - size_t off = out->len + lseek(out->fd, 0, SEEK_CUR); - while (off++ & (align - 1)) ioputc(out, 0); -} - -static const bool userelatab[] = { [ISx86_64] = 1, [ISaarch64] = 1 }; - -void -elffini(struct wbuf *out) -{ - enum { - shnam_text = 1, shnam_rodata = 7, shnam_data = 15, shnam_bss = 21, shnam_shstrtab = 26, - shnam_strtab = 36, shnam_symtab = 44, shnam_reltext = 52, shnam_relrodata = 63, shnam_reldata = 76 - }; - int align = targ_64bit ? 8 : 4; - bool userela = userelatab[target.arch]; - char shstrs[] = "\0.text\0.rodata\0.data\0.bss\0.shstrtab\0.strtab\0.symtab\0" - ".rela.text\0.rela.rodata\0.rela.data"; - if (!userela) { - /* .rela -> .rel */ - memcpy(shstrs + shnam_reltext + 4, ".text\0", 6); - memcpy(shstrs + shnam_relrodata + 4, ".rodata\0", 8); - memcpy(shstrs + shnam_reldata + 4, ".data\0", 6); - } - - symtab.p[1].name = str2idx(objout.infile); - /* create a mapping of original symbol index -> sorted symtab index */ - uint ndefsym = symtab.n; - ushort ssbuf[2<<10], - *sortedsyms = ndefsym*2 < countof(ssbuf) ? ssbuf : xmalloc(sizeof *sortedsyms * ndefsym*2), - *defsym2idx = sortedsyms + ndefsym; - for (int i = 0; i < ndefsym; ++i) sortedsyms[i] = i; - qsort(sortedsyms+2, ndefsym-2, sizeof *sortedsyms, symcmp); - for (int i = 0; i < ndefsym; ++i) defsym2idx[sortedsyms[i]] = i; - - /* fixup relocs */ - for (int i = 0; i < relocs.n; ++i) { - struct reloc *rel = &relocs.p[i]; - struct sym *sym = findsym(rel->symname); - if (sym) { - uint idx = sym - symtab.p; - rel->symidx = idx < ndefsym ? defsym2idx[idx] : idx; - } else { - assert(symtab.n < 1<<16); - vpush(&symtab, ((struct sym) { str2idx(&rel->symname->c), .bind = STB_GLOBAL, .type = STT_NOTYPE, .shndx = SHN_UND })); - pmap_set(&symht, rel->symname, symtab.n-1); - rel->symidx = symtab.n-1; - } - if (!userela) { - uchar *p; - switch (rel->section) { - default: assert(0); - case Sdata: p = O.data.p + rel->off; break; - case Srodata: p = O.rodata.p + rel->off; break; - case Stext: p = O.textbegin + rel->off; break; - } - if (targ_64bit) - wr64targ(p, rel->addend); - else - wr32targ(p, rel->addend); - } - } - size_t codesize = alignup(O.code - O.textbegin, align), - rodataoff = (targ_64bit ? sizeof hdr.h64 : sizeof hdr.h32) + codesize, - rodatasize = O.rodata.n, - dataoff = rodataoff + rodatasize, - datasize = O.data.n, - bsssize = O.nbss, - shstrsoff = dataoff + datasize, - shstrssize = sizeof(shstrs), - strsoff = shstrsoff + shstrssize, - strssize = strs.n, - symtaboff = alignup(strsoff + strssize, align), - symtabsize = symtab.n * (targ_64bit ? 24 : 16), - reltextoff = symtaboff + symtabsize, - relxsiz = userela ? (targ_64bit ? 24 : 12) : (targ_64bit ? 16 : 8), - reltextsize = ntextrel * relxsiz, - relrodataoff = reltextoff + reltextsize, - relrodatasize = nrodatarel * relxsiz, - reldataoff = relrodataoff + relrodatasize, - reldatasize = ndatarel * relxsiz; - int nlocal = 0; - -#define CHECKOFF(s, x) \ - efmt(s " expect OFF: %u ; ACTUAL %u\n", (uint)(x),(uint)(lseek(out->fd, 0, SEEK_CUR) + out->len)) - - if (targ_64bit) { - hdr.h64.shoff = alignup(reldataoff + reldatasize, align); - hdr.h64.shnum = 11; - hdr.h64.shstrndx = 5; - } else { - hdr.h32.shoff = alignup(reldataoff + reldatasize, align); - hdr.h32.shnum = 11; - hdr.h32.shstrndx = 5; - } - - /* elf header */ - if (targ_64bit) - elf64puthdr(out, &hdr.h64); - else - elf32puthdr(out, &hdr.h32); - - /* .text progbits */ - iowrite(out, O.textbegin, codesize); - - /* .rodata progbits */ - iowrite(out, O.rodata.p, O.rodata.n); - - /* .data progbits */ - iowrite(out, O.data.p, O.data.n); - - /* section names */ - iowrite(out, shstrs, sizeof shstrs); - - /* strings */ - iowrite(out, strs.p, strs.n); - - /* symtab */ - wordalign(out, align); - for (int i = 0; i < symtab.n; ++i) { - struct sym *sym = &symtab.p[i < ndefsym ? sortedsyms[i] : i]; - if (sym->bind == STB_LOCAL) ++nlocal; - putsym(out, sym); - } - if (sortedsyms != ssbuf) free(sortedsyms); - - /* rel.* */ - assert(relocs.n == ntextrel + nrodatarel + ndatarel); - for (enum section s = Stext; s <= Sbss; ++s) { - for (int i = 0; i < relocs.n; ++i) { - struct reloc *rel = &relocs.p[i]; - if (rel->section != s) continue; - putreloc(out, rel, userela); - } - } - - /** Section Headers **/ - wordalign(out, align); -#define putshdr(...) if (targ_64bit) elf64putshdr(out, &(struct elf64shdr) { __VA_ARGS__ }); \ - else elf32putshdr(out, &(struct elf32shdr) { __VA_ARGS__ }); - /* §0 null section */ - putshdr(0); - /* §1 .text */ - putshdr(.name = shnam_text, .type = SHT_PROGBITS, - .flags = SHF_ALLOC | SHF_EXECINSTR, - .offset = targ_64bit ? hdr.h64.ehsize : hdr.h32.ehsize, .size = codesize, - .addralign = align); - /* §2 .rodata */ - putshdr(.name = shnam_rodata, .type = SHT_PROGBITS, - .flags = SHF_ALLOC, - .offset = rodataoff, .size = rodatasize, - .addralign = O.rodataalign,); - /* §3 .data */ - putshdr(.name = shnam_data, .type = SHT_PROGBITS, - .flags = SHF_ALLOC | SHF_WRITE, - .offset = dataoff, .size = datasize, - .addralign = O.dataalign,); - /* §4 .bss */ - putshdr(.name = shnam_bss, .type = SHT_NOBITS, - .size = bsssize, - .flags = SHF_ALLOC | SHF_WRITE, - .addralign = O.bssalign,); - /* §5 .shstrtab */ - putshdr(.name = shnam_shstrtab, .type = SHT_STRTAB, - .offset = shstrsoff, .size = shstrssize, - .flags = SHF_STRINGS ); - /* §6 .strtab */ - putshdr(.name = shnam_strtab, .type = SHT_STRTAB, - .offset = strsoff, .size = strssize, - .flags = SHF_STRINGS ); - /* §7 .symtab */ - putshdr(.name = shnam_symtab, .type = SHT_SYMTAB, - .offset = symtaboff, .size = symtabsize, - .flags = SHF_STRINGS, - .link = 6, /* .strtab */ - .info = nlocal, - .entsize = targ_64bit ? 24 : 16 ); - /* §8 .rel.text */ - putshdr(.name = shnam_reltext, .type = SHT_RELA, - .offset = reltextoff, .size = reltextsize, - .link = 7, /* .symtab */ - .entsize = relxsiz, - .info = TEXT_SHNDX ); - /* §9 .rel.rodata */ - putshdr(.name = shnam_relrodata, .type = SHT_RELA, - .offset = relrodataoff, .size = relrodatasize, - .link = 7, /* .symtab */ - .entsize = relxsiz, - .info = RODATA_SHNDX ); - /* §10 .rel.data */ - putshdr(.name = shnam_reldata, .type = SHT_RELA, - .offset = reldataoff, .size = reldatasize, - .link = 7, /* .symtab */ - .entsize = relxsiz, - .info = DATA_SHNDX ); -} - -/* vim:set ts=3 sw=3 expandtab: */ -- cgit v1.2.3