experiment with being a linker
Andrew Kelley
parent
174baa49bd
commit
775e98be5a
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@ -24,11 +24,12 @@ set(GRAMMAR_TXT "${CMAKE_BINARY_DIR}/simple.txt")
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set(PARSER_GENERATED_CPP "${CMAKE_BINARY_DIR}/parser_generated.cpp")
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set(ZIG_SOURCES
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"${CMAKE_SOURCE_DIR}/src/main.cpp"
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"${CMAKE_SOURCE_DIR}/src/util.cpp"
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"${CMAKE_SOURCE_DIR}/src/buffer.cpp"
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"${CMAKE_SOURCE_DIR}/src/tokenizer.cpp"
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"${CMAKE_SOURCE_DIR}/src/error.cpp"
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"${CMAKE_SOURCE_DIR}/src/main.cpp"
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"${CMAKE_SOURCE_DIR}/src/parser.cpp"
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"${CMAKE_SOURCE_DIR}/src/tokenizer.cpp"
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"${CMAKE_SOURCE_DIR}/src/util.cpp"
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${PARSER_GENERATED_CPP}
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)
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@ -0,0 +1,9 @@
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#include "error.hpp"
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const char *err_str(int err) {
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switch ((enum Error)err) {
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case ErrorNoMem: return "out of memory";
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case ErrorInvalidFormat: return "invalid format";
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}
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return "(invalid error)";
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}
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@ -0,0 +1,18 @@
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/*
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* Copyright (c) 2015 Andrew Kelley
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*
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* This file is part of zig, which is MIT licensed.
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* See http://opensource.org/licenses/MIT
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*/
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#ifndef ERROR_HPP
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#define ERROR_HPP
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enum Error {
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ErrorNoMem,
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ErrorInvalidFormat,
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};
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const char *err_str(int err);
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#endif
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437
src/main.cpp
437
src/main.cpp
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@ -11,6 +11,7 @@
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#include "buffer.hpp"
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#include "parser.hpp"
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#include "tokenizer.hpp"
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#include "error.hpp"
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#include <stdio.h>
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#include <string.h>
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@ -21,12 +22,17 @@
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <unistd.h>
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#include <inttypes.h>
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static int usage(char *arg0) {
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fprintf(stderr, "Usage: %s --output outfile code.zig\n"
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"Other options:\n"
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"--version print version number and exit\n"
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"-Ipath add path to header include path\n"
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static int usage(const char *arg0) {
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fprintf(stderr, "Usage: %s [command] [options] target\n"
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"Commands:\n"
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" build create an executable from target\n"
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" link turn a .o file into an executable\n"
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"Options:\n"
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" --output output file\n"
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" --version print version number and exit\n"
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" -Ipath add path to header include path\n"
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, arg0);
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return EXIT_FAILURE;
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}
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@ -49,37 +55,8 @@ static Buf *fetch_file(FILE *f) {
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return buf;
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}
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char cur_dir[1024];
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int main(int argc, char **argv) {
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char *arg0 = argv[0];
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char *in_file = NULL;
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char *out_file = NULL;
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ZigList<char *> include_paths = {0};
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for (int i = 1; i < argc; i += 1) {
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char *arg = argv[i];
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if (arg[0] == '-' && arg[1] == '-') {
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if (strcmp(arg, "--version") == 0) {
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printf("%s\n", ZIG_VERSION_STRING);
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return EXIT_SUCCESS;
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} else if (i + 1 >= argc) {
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return usage(arg0);
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} else {
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i += 1;
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if (strcmp(arg, "--output") == 0) {
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out_file = argv[i];
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} else {
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return usage(arg0);
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}
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}
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} else if (arg[0] == '-' && arg[1] == 'I') {
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include_paths.append(arg + 2);
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} else if (!in_file) {
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in_file = arg;
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} else {
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return usage(arg0);
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}
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}
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static int build(const char *arg0, const char *in_file, const char *out_file, ZigList<char *> *include_paths) {
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static char cur_dir[1024];
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if (!in_file || !out_file)
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return usage(arg0);
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@ -116,5 +93,391 @@ int main(int argc, char **argv) {
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ast_print(root, 0);
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return EXIT_SUCCESS;
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return 0;
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}
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enum ElfType {
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ElfTypeRelocatable,
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ElfTypeExecutable,
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ElfTypeShared,
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ElfTypeCore,
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};
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enum ElfArch {
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ElfArchSparc,
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ElfArchx86,
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ElfArchMips,
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ElfArchPowerPc,
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ElfArchArm,
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ElfArchSuperH,
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ElfArchIA_64,
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ElfArchx86_64,
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ElfArchAArch64,
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};
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enum ElfSectionType {
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SHT_NULL = 0,
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SHT_PROGBITS = 1,
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SHT_SYMTAB = 2,
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SHT_STRTAB = 3,
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SHT_RELA = 4,
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SHT_HASH = 5,
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SHT_DYNAMIC = 6,
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SHT_NOTE = 7,
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SHT_NOBITS = 8,
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SHT_REL = 9,
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SHT_SHLIB = 10,
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SHT_DYNSYM = 11,
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SHT_INIT_ARRAY = 14,
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SHT_FINI_ARRAY = 15,
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SHT_PREINIT_ARRAY = 16,
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SHT_GROUP = 17,
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SHT_SYMTAB_SHNDX = 18,
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SHT_LOOS = 0x60000000,
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SHT_HIOS = 0x6fffffff,
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SHT_LOPROC = 0x70000000,
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SHT_HIPROC = 0x7fffffff,
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SHT_LOUSER = 0x80000000,
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SHT_HIUSER = 0xffffffff,
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};
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struct Elf32SectionHeader {
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uint32_t name;
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uint32_t type;
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uint32_t flags;
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size_t addr;
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off_t offset;
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uint32_t size;
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uint32_t link;
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uint32_t info;
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uint32_t addralign;
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uint32_t entsize;
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};
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struct Elf64SectionHeader{
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uint32_t name;
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uint32_t type;
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uint64_t flags;
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size_t addr;
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off_t offset;
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uint64_t size;
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uint32_t link;
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uint32_t info;
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uint64_t addralign;
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uint64_t entsize;
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};
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struct Elf {
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bool is_64;
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bool is_little_endian;
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ElfType type;
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ElfArch arch;
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uint64_t entry_addr;
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uint64_t program_header_offset;
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uint64_t section_header_offset;
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int sh_entry_count;
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int string_section_index;
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union {
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Elf32SectionHeader *elf32_section_headers;
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Elf64SectionHeader *elf64_section_headers;
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};
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};
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static int parse_elf(Elf *elf, Buf *buf) {
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int len = buf_len(buf);
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if (len < 52) {
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return ErrorInvalidFormat;
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}
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char *ptr = buf_ptr(buf);
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static const int magic_size = 4;
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static const char magic[magic_size] = {0x7f, 'E', 'L', 'F'};
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if (memcmp(ptr, magic, magic_size) != 0) {
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return ErrorInvalidFormat;
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}
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ptr += magic_size;
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if (*ptr == 1) {
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elf->is_64 = false;
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} else if (*ptr == 2) {
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elf->is_64 = true;
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if (len < 64)
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return ErrorInvalidFormat;
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} else {
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return ErrorInvalidFormat;
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}
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ptr += 1;
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if (*ptr == 1) {
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elf->is_little_endian = true;
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} else if (*ptr == 2) {
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elf->is_little_endian = false;
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zig_panic("can only handle little endian");
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} else {
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return ErrorInvalidFormat;
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}
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ptr += 1;
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if (*ptr != 1) {
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return ErrorInvalidFormat;
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}
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uint16_t *type_number = (uint16_t *)&buf_ptr(buf)[0x10];
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if (*type_number == 1) {
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elf->type = ElfTypeRelocatable;
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} else if (*type_number == 2) {
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elf->type = ElfTypeExecutable;
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} else if (*type_number == 3) {
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elf->type = ElfTypeShared;
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} else if (*type_number == 4) {
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elf->type = ElfTypeCore;
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} else {
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return ErrorInvalidFormat;
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}
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uint16_t *arch = (uint16_t *)&buf_ptr(buf)[0x12];
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if (*arch == 0x02) {
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elf->arch = ElfArchSparc;
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} else if (*arch == 0x03) {
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elf->arch = ElfArchx86;
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} else if (*arch == 0x08) {
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elf->arch = ElfArchMips;
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} else if (*arch == 0x14) {
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elf->arch = ElfArchPowerPc;
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} else if (*arch == 0x28) {
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elf->arch = ElfArchArm;
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} else if (*arch == 0x2A) {
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elf->arch = ElfArchSuperH;
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} else if (*arch == 0x32) {
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elf->arch = ElfArchIA_64;
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} else if (*arch == 0x3E) {
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elf->arch = ElfArchx86_64;
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} else if (*arch == 0xb7) {
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elf->arch = ElfArchAArch64;
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} else {
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return ErrorInvalidFormat;
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}
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uint32_t *elf_vers = (uint32_t *)&buf_ptr(buf)[0x14];
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if (*elf_vers != 1) {
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return ErrorInvalidFormat;
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}
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ptr = &buf_ptr(buf)[0x18];
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if (elf->is_64) {
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elf->entry_addr = *((uint64_t *)ptr);
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ptr += 8;
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elf->program_header_offset = *((uint64_t *)ptr);
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ptr += 8;
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elf->section_header_offset = *((uint64_t *)ptr);
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ptr += 8;
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} else {
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elf->entry_addr = *((uint32_t *)ptr);
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ptr += 4;
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elf->program_header_offset = *((uint32_t *)ptr);
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ptr += 4;
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elf->section_header_offset = *((uint32_t *)ptr);
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ptr += 4;
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}
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// skip over flags
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ptr += 4;
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uint16_t header_size = *((uint16_t*)ptr);
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if ((elf->is_64 && header_size != 64) || (!elf->is_64 && header_size != 52)) {
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return ErrorInvalidFormat;
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}
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ptr += 2;
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uint16_t ph_entry_size = *((uint16_t*)ptr);
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ptr += 2;
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uint16_t ph_entry_count = *((uint16_t*)ptr);
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ptr += 2;
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uint16_t sh_entry_size = *((uint16_t*)ptr);
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ptr += 2;
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uint16_t sh_entry_count = *((uint16_t*)ptr);
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ptr += 2;
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uint16_t sh_name_index = *((uint16_t*)ptr);
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ptr += 2;
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elf->string_section_index = sh_name_index;
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if (elf->string_section_index >= sh_entry_count) {
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return ErrorInvalidFormat;
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}
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long sh_byte_count = ((long) sh_entry_size) * ((long) sh_entry_count);
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long end_sh = ((long)elf->section_header_offset) + sh_byte_count;
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long end_ph = ((long)elf->program_header_offset) + ((long) ph_entry_size) * ((long) ph_entry_count);
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if (len < end_sh || len < end_ph) {
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return ErrorInvalidFormat;
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}
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ptr = &buf_ptr(buf)[elf->section_header_offset];
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if (elf->is_64) {
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if (sh_entry_size != sizeof(Elf64SectionHeader)) {
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return ErrorInvalidFormat;
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}
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elf->elf64_section_headers = allocate<Elf64SectionHeader>(sh_entry_count);
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memcpy(elf->elf64_section_headers, ptr, sh_byte_count);
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elf->sh_entry_count = sh_entry_count;
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Elf64SectionHeader *string_section = &elf->elf64_section_headers[elf->string_section_index];
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if (string_section->type != SHT_STRTAB) {
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// not a string table
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return ErrorInvalidFormat;
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}
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// validate section types and offsets
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for (int i = 0; i < elf->sh_entry_count; i += 1) {
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Elf64SectionHeader *section = &elf->elf64_section_headers[i];
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if (section->type != SHT_NOBITS) {
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long file_end_offset = ((long)section->offset) + ((long)section->size);
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if (len < file_end_offset) {
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return ErrorInvalidFormat;
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}
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}
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}
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for (int i = 0; i < elf->sh_entry_count; i += 1) {
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Elf64SectionHeader *section = &elf->elf64_section_headers[i];
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if (section->type == SHT_NULL)
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continue;
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long name_offset = section->name;
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ptr = &buf_ptr(buf)[string_section->offset + name_offset];
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fprintf(stderr, "section: %s\n", ptr);
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fprintf(stderr, " start: 0x%" PRIx64 "\n", (uint64_t)section->offset);
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fprintf(stderr, " end: 0x%" PRIx64 "\n", (uint64_t)section->offset + (uint64_t)section->size);
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if (section->type == SHT_SYMTAB) {
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fprintf(stderr, " symtab\n");
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} else if (section->type == SHT_DYNSYM) {
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fprintf(stderr, " dynsym\n");
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zig_panic("TODO SHT_DYNSYM");
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}
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}
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} else {
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if (sh_entry_size != sizeof(Elf32SectionHeader))
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return ErrorInvalidFormat;
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zig_panic("TODO 32-bit ELF");
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}
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return 0;
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}
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static int link(const char *arg0, const char *in_file, const char *out_file) {
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if (!in_file || !out_file)
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return usage(arg0);
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FILE *in_f;
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if (strcmp(in_file, "-") == 0) {
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in_f = stdin;
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} else {
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in_f = fopen(in_file, "rb");
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if (!in_f)
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zig_panic("unable to open %s for reading: %s\n", in_file, strerror(errno));
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}
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Buf *in_data = fetch_file(in_f);
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Elf elf = {0};
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int err;
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if ((err = parse_elf(&elf, in_data))) {
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fprintf(stderr, "unable to parse ELF: %s\n", err_str(err));
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return 1;
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}
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fprintf(stderr, "ELF is 64? %d\n", (int)elf.is_64);
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fprintf(stderr, "arch: %d\n", (int)elf.arch);
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fprintf(stderr, "exe? %d\n", (int)(elf.type == ElfTypeExecutable));
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fprintf(stderr, "entry: 0x%" PRIx64 "\n", elf.entry_addr);
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return 0;
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}
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enum Cmd {
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CmdNone,
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CmdBuild,
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CmdLink,
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};
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int main(int argc, char **argv) {
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char *arg0 = argv[0];
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char *in_file = NULL;
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char *out_file = NULL;
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ZigList<char *> include_paths = {0};
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Cmd cmd = CmdNone;
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for (int i = 1; i < argc; i += 1) {
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char *arg = argv[i];
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if (arg[0] == '-' && arg[1] == '-') {
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if (strcmp(arg, "--version") == 0) {
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printf("%s\n", ZIG_VERSION_STRING);
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return EXIT_SUCCESS;
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} else if (i + 1 >= argc) {
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return usage(arg0);
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} else {
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i += 1;
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if (strcmp(arg, "--output") == 0) {
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out_file = argv[i];
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} else {
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return usage(arg0);
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}
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}
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} else if (arg[0] == '-' && arg[1] == 'I') {
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include_paths.append(arg + 2);
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} else if (cmd == CmdNone) {
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if (strcmp(arg, "build") == 0) {
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cmd = CmdBuild;
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} else if (strcmp(arg, "link") == 0) {
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cmd = CmdLink;
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} else {
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fprintf(stderr, "Unrecognized command: %s\n", arg);
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return usage(arg0);
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}
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} else {
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switch (cmd) {
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case CmdNone:
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zig_panic("unreachable");
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case CmdBuild:
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if (!in_file) {
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in_file = arg;
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} else {
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return usage(arg0);
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}
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||||
break;
|
||||
case CmdLink:
|
||||
if (!in_file) {
|
||||
in_file = arg;
|
||||
} else {
|
||||
return usage(arg0);
|
||||
}
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
switch (cmd) {
|
||||
case CmdNone:
|
||||
return usage(arg0);
|
||||
case CmdBuild:
|
||||
return build(arg0, in_file, out_file, &include_paths);
|
||||
break;
|
||||
case CmdLink:
|
||||
return link(arg0, in_file, out_file);
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
|
|
|
|||
Loading…
Reference in New Issue