mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-01-31 19:43:32 +00:00
6f7d0cb1c3
This makes breaking changes to add underscores to many non-standard function names provided by the c library. MODE=tiny is now tinier and we now use smaller locks that are better for tiny apps in this mode. Some headers have been renamed to be in the same folder as the build package, so it'll be easier to know which build dependency is needed. Certain old misguided interfaces have been removed. Intel intrinsics headers are now listed in libc/isystem (but not in the amalgamation) to help further improve open source compatibility. Header complexity has also been reduced. Lastly, more shell scripts are now available.
276 lines
11 KiB
C
276 lines
11 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2020 Justine Alexandra Roberts Tunney │
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│ │
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│ Permission to use, copy, modify, and/or distribute this software for │
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│ any purpose with or without fee is hereby granted, provided that the │
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│ above copyright notice and this permission notice appear in all copies. │
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│ │
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│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
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│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
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│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
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│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
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│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
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│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
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│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
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│ PERFORMANCE OF THIS SOFTWARE. │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/assert.h"
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#include "libc/calls/calls.h"
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#include "libc/elf/def.h"
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#include "libc/log/check.h"
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#include "libc/mem/arraylist2.internal.h"
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#include "libc/mem/gc.h"
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#include "libc/runtime/memtrack.internal.h"
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#include "libc/stdalign.internal.h"
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#include "libc/str/str.h"
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#include "libc/sysv/consts/map.h"
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#include "libc/sysv/consts/msync.h"
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#include "libc/sysv/consts/o.h"
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#include "libc/sysv/consts/prot.h"
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#include "libc/x/xasprintf.h"
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#include "tool/build/lib/elfwriter.h"
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static const Elf64_Ehdr kObjHeader = {
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.e_ident = {ELFMAG0, ELFMAG1, ELFMAG2, ELFMAG3, ELFCLASS64, ELFDATA2LSB, 1,
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ELFOSABI_NONE},
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.e_type = ET_REL,
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.e_machine = EM_NEXGEN32E,
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.e_version = 1,
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.e_ehsize = sizeof(Elf64_Ehdr),
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.e_shentsize = sizeof(Elf64_Shdr),
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};
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static size_t AppendSection(struct ElfWriter *elf, const char *name,
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int sh_type, int sh_flags) {
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ssize_t section =
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APPEND(&elf->shdrs->p, &elf->shdrs->i, &elf->shdrs->n,
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(&(Elf64_Shdr){.sh_type = sh_type,
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.sh_flags = sh_flags,
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.sh_entsize = elf->entsize,
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.sh_addralign = elf->addralign,
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.sh_offset = sh_type != SHT_NULL ? elf->wrote : 0,
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.sh_name = intern(elf->shstrtab, name)}));
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CHECK_NE(-1, section);
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return section;
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}
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static size_t FinishSection(struct ElfWriter *elf) {
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size_t section = elf->shdrs->i - 1;
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elf->shdrs->p[section].sh_size =
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elf->wrote - elf->shdrs->p[section].sh_offset;
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return section;
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}
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static struct ElfWriterSymRef AppendSymbol(struct ElfWriter *elf,
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const char *name, int st_info,
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int st_other, size_t st_value,
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size_t st_size, size_t st_shndx,
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enum ElfWriterSymOrder slg) {
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ssize_t sym =
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APPEND(&elf->syms[slg]->p, &elf->syms[slg]->i, &elf->syms[slg]->n,
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(&(Elf64_Sym){.st_info = st_info,
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.st_size = st_size,
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.st_value = st_value,
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.st_other = st_other,
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.st_name = intern(elf->strtab, name),
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.st_shndx = st_shndx}));
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CHECK_NE(-1, sym);
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return (struct ElfWriterSymRef){.slg = slg, .sym = sym};
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}
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static void MakeRelaSection(struct ElfWriter *elf, size_t section) {
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size_t shdr, size;
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size = (elf->relas->i - elf->relas->j) * sizeof(Elf64_Rela);
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elfwriter_align(elf, alignof(Elf64_Rela), sizeof(Elf64_Rela));
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shdr = elfwriter_startsection(
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elf,
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_gc(xasprintf("%s%s", ".rela",
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&elf->shstrtab->p[elf->shdrs->p[section].sh_name])),
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SHT_RELA, SHF_INFO_LINK);
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elf->shdrs->p[shdr].sh_info = section;
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elfwriter_reserve(elf, size);
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elfwriter_commit(elf, size);
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FinishSection(elf);
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elf->relas->j = elf->relas->i;
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}
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static void WriteRelaSections(struct ElfWriter *elf, size_t symtab) {
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uint32_t sym;
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size_t i, j, k;
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Elf64_Rela *rela;
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for (j = 0, i = 0; i < elf->shdrs->i; ++i) {
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if (elf->shdrs->p[i].sh_type == SHT_RELA) {
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elf->shdrs->p[i].sh_link = symtab;
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for (rela = (Elf64_Rela *)((char *)elf->map + elf->shdrs->p[i].sh_offset);
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rela <
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(Elf64_Rela *)((char *)elf->map + (elf->shdrs->p[i].sh_offset +
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elf->shdrs->p[i].sh_size));
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rela++, j++) {
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sym = elf->relas->p[j].symkey.sym;
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for (k = 0; k < elf->relas->p[j].symkey.slg; ++k) {
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sym += elf->syms[k]->i;
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}
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rela->r_offset = elf->relas->p[j].offset;
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rela->r_info = ELF64_R_INFO(sym, elf->relas->p[j].type);
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rela->r_addend = elf->relas->p[j].addend;
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}
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}
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}
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assert(j == elf->relas->i);
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}
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static size_t FlushStrtab(struct ElfWriter *elf, const char *name,
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struct Interner *strtab) {
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size_t size = strtab->i * sizeof(strtab->p[0]);
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elfwriter_align(elf, 1, 0);
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AppendSection(elf, name, SHT_STRTAB, 0);
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mempcpy(elfwriter_reserve(elf, size), strtab->p, size);
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elfwriter_commit(elf, size);
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return FinishSection(elf);
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}
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static void FlushTables(struct ElfWriter *elf) {
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size_t i, size, symtab;
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elfwriter_align(elf, alignof(Elf64_Sym), sizeof(Elf64_Sym));
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symtab = AppendSection(elf, ".symtab", SHT_SYMTAB, 0);
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for (i = 0; i < ARRAYLEN(elf->syms); ++i) {
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size = elf->syms[i]->i * sizeof(Elf64_Sym);
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if (size) {
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memcpy(elfwriter_reserve(elf, size), elf->syms[i]->p, size);
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}
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elfwriter_commit(elf, size);
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}
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FinishSection(elf);
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elf->shdrs->p[symtab].sh_link = FlushStrtab(elf, ".strtab", elf->strtab);
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elf->ehdr->e_shstrndx = FlushStrtab(elf, ".shstrtab", elf->shstrtab);
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WriteRelaSections(elf, symtab);
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size = elf->shdrs->i * sizeof(elf->shdrs->p[0]);
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elfwriter_align(elf, alignof(Elf64_Shdr), sizeof(elf->shdrs->p[0]));
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elf->ehdr->e_shoff = elf->wrote;
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elf->ehdr->e_shnum = elf->shdrs->i;
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elf->shdrs->p[symtab].sh_info =
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elf->syms[kElfWriterSymSection]->i + elf->syms[kElfWriterSymLocal]->i;
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mempcpy(elfwriter_reserve(elf, size), elf->shdrs->p, size);
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elfwriter_commit(elf, size);
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}
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struct ElfWriter *elfwriter_open(const char *path, int mode) {
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struct ElfWriter *elf;
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CHECK_NOTNULL((elf = calloc(1, sizeof(struct ElfWriter))));
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CHECK_NOTNULL((elf->path = strdup(path)));
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CHECK_NE(-1, (elf->fd = open(elf->path, O_CREAT | O_TRUNC | O_RDWR, mode)));
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CHECK_NE(-1, ftruncate(elf->fd, (elf->mapsize = FRAMESIZE)));
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CHECK_NE(MAP_FAILED, (elf->map = mmap((void *)(intptr_t)kFixedmapStart,
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elf->mapsize, PROT_READ | PROT_WRITE,
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MAP_SHARED | MAP_FIXED, elf->fd, 0)));
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elf->ehdr = memcpy(elf->map, &kObjHeader, (elf->wrote = sizeof(kObjHeader)));
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elf->strtab = newinterner();
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elf->shstrtab = newinterner();
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intern(elf->strtab, "");
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intern(elf->shstrtab, "");
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intern(elf->shstrtab, ".shstrtab");
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return elf;
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}
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void elfwriter_close(struct ElfWriter *elf) {
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size_t i;
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FlushTables(elf);
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CHECK_NE(-1, msync(elf->map, elf->wrote, MS_ASYNC));
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CHECK_NE(-1, munmap(elf->map, elf->mapsize));
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CHECK_NE(-1, ftruncate(elf->fd, elf->wrote));
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CHECK_NE(-1, close(elf->fd));
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freeinterner(elf->shstrtab);
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freeinterner(elf->strtab);
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free(elf->shdrs->p);
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free(elf->relas->p);
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free(elf->path);
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for (i = 0; i < ARRAYLEN(elf->syms); ++i) {
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free(elf->syms[i]->p);
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}
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free(elf);
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}
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void elfwriter_align(struct ElfWriter *elf, size_t addralign, size_t entsize) {
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elf->entsize = entsize;
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elf->addralign = addralign;
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elf->wrote = ROUNDUP(elf->wrote, addralign);
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}
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size_t elfwriter_startsection(struct ElfWriter *elf, const char *name,
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int sh_type, int sh_flags) {
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size_t shdr = AppendSection(elf, name, sh_type, sh_flags);
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AppendSymbol(elf, "",
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sh_type != SHT_NULL ? ELF64_ST_INFO(STB_LOCAL, STT_SECTION)
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: ELF64_ST_INFO(STB_LOCAL, STT_NOTYPE),
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STV_DEFAULT, 0, 0, shdr, kElfWriterSymSection);
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return shdr;
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}
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void *elfwriter_reserve(struct ElfWriter *elf, size_t size) {
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size_t need, greed;
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need = elf->wrote + size;
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greed = elf->mapsize;
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if (need > greed) {
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do {
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greed = greed + (greed >> 1);
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} while (need > greed);
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greed = ROUNDUP(greed, FRAMESIZE);
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CHECK_NE(-1, ftruncate(elf->fd, greed));
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CHECK_NE(MAP_FAILED, mmap((char *)elf->map + elf->mapsize,
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greed - elf->mapsize, PROT_READ | PROT_WRITE,
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MAP_SHARED | MAP_FIXED, elf->fd, elf->mapsize));
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elf->mapsize = greed;
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}
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return (char *)elf->map + elf->wrote;
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}
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void elfwriter_commit(struct ElfWriter *elf, size_t size) {
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elf->wrote += size;
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}
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void elfwriter_finishsection(struct ElfWriter *elf) {
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size_t section = FinishSection(elf);
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if (elf->relas->j < elf->relas->i) MakeRelaSection(elf, section);
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}
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/**
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* Appends symbol.
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*
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* This function should be called between elfwriter_startsection() and
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* elfwriter_finishsection(). If that's not possible, then this can be
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* called after elfwriter_open() and then elfwriter_setsection() can be
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* called later to fix-up the section id.
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*/
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struct ElfWriterSymRef elfwriter_appendsym(struct ElfWriter *elf,
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const char *name, int st_info,
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int st_other, size_t st_value,
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size_t st_size) {
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return AppendSymbol(
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elf, name, st_info, st_other, st_value, st_size, elf->shdrs->i - 1,
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ELF64_ST_BIND(st_info) == STB_LOCAL ? kElfWriterSymLocal
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: kElfWriterSymGlobal);
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}
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void elfwriter_setsection(struct ElfWriter *elf, struct ElfWriterSymRef sym,
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uint16_t st_shndx) {
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elf->syms[sym.slg]->p[sym.sym].st_shndx = st_shndx;
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}
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struct ElfWriterSymRef elfwriter_linksym(struct ElfWriter *elf,
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const char *name, int st_info,
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int st_other) {
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return AppendSymbol(elf, name, st_info, st_other, 0, 0, 0,
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kElfWriterSymGlobal);
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}
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void elfwriter_appendrela(struct ElfWriter *elf, uint64_t r_offset,
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struct ElfWriterSymRef symkey, uint32_t type,
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int64_t r_addend) {
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CHECK_NE(-1, APPEND(&elf->relas->p, &elf->relas->i, &elf->relas->n,
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(&(struct ElfWriterRela){.type = type,
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.symkey = symkey,
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.offset = r_offset,
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.addend = r_addend})));
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}
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