elna/source/cl.cpp

126 lines
4.8 KiB
C++

#include "elna/cl.hpp"
#include "elna/result.hpp"
#include "elna/riscv.hpp"
#include <cstddef>
#include <elfio/elfio.hpp>
#include <fstream>
#include <sstream>
namespace elna
{
char *readSource(const char *source)
{
const std::size_t bufferSize = 255;
std::ifstream input_stream{ source };
std::stringstream buffer;
buffer << input_stream.rdbuf();
input_stream.close();
std::string contents = buffer.str();
char *result = reinterpret_cast<char *>(malloc(contents.size() + 1));
std::copy(std::cbegin(contents), std::cend(contents), result);
result[contents.size()] = '\0';
return result;
}
int compile(const std::filesystem::path& in_file, const std::filesystem::path& out_file)
{
ELFIO::elfio writer;
// You can't proceed before this function call!
writer.create(ELFIO::ELFCLASS32, ELFIO::ELFDATA2LSB);
writer.set_os_abi(ELFIO::ELFOSABI_NONE);
writer.set_type(ELFIO::ET_REL);
writer.set_machine(ELFIO::EM_RISCV);
auto sourceText = readSource(in_file.c_str());
if (sourceText == nullptr)
{
return 3;
}
size_t tokensCount{ 0 };
auto lex_result = lex::lex(sourceText);
free(sourceText);
if (lex_result.has_errors())
{
for (const auto& compile_error : lex_result.errors())
{
printf("%lu:%lu: %s\n", compile_error.line(), compile_error.column(), compile_error.what());
}
return 1;
}
auto ast = parse(lex_result.success().data(), tokensCount);
if (ast == nullptr)
{
return 2;
}
auto program = writeNext(ast);
// Create code section
ELFIO::section* text_sec = writer.sections.add(".text");
text_sec->set_type(ELFIO::SHT_PROGBITS);
text_sec->set_flags(ELFIO::SHF_ALLOC | ELFIO::SHF_EXECINSTR);
text_sec->set_addr_align(0x1);
text_sec->set_data(reinterpret_cast<const char *>(program.text.data()), program.text.size());
// Create string table section
ELFIO::section* str_sec = writer.sections.add(".strtab");
str_sec->set_type(ELFIO::SHT_STRTAB);
// Create string table writer
ELFIO::string_section_accessor stra(str_sec);
// Add label name
ELFIO::Elf32_Word str_index = stra.add_string("msg");
// Create read only data section
ELFIO::section* ro_sec = writer.sections.add(".rodata");
ro_sec->set_type(ELFIO::SHT_PROGBITS);
ro_sec->set_flags(ELFIO::SHF_ALLOC);
ro_sec->set_addr_align(0x4);
ro_sec->set_data("%d\n");
// Create symbol table section
ELFIO::section* sym_sec = writer.sections.add(".symtab");
sym_sec->set_type(ELFIO::SHT_SYMTAB);
sym_sec->set_info(2);
sym_sec->set_addr_align(0x4);
sym_sec->set_entry_size(writer.get_default_entry_size(ELFIO::SHT_SYMTAB));
sym_sec->set_link(str_sec->get_index());
// Create symbol table writer
ELFIO::symbol_section_accessor syma(writer, sym_sec);
auto label_sym = syma.add_symbol(stra, ".CL0", 0x00000000, strlen("%d\n") + 1,
ELFIO::STB_LOCAL, ELFIO::STT_NOTYPE, 0, ro_sec->get_index());
syma.add_symbol(stra, program.name, 0x00000000, program.text.size(),
ELFIO::STB_GLOBAL, ELFIO::STT_FUNC, 0, text_sec->get_index());
auto printf_sym = syma.add_symbol(stra, "printf", 0x00000000, 0,
ELFIO::STB_GLOBAL, ELFIO::STT_NOTYPE, 0, ELFIO::SHN_UNDEF);
// Create relocation table section
ELFIO::section* rel_sec = writer.sections.add(".rel.text");
rel_sec->set_type(ELFIO::SHT_REL);
rel_sec->set_info(text_sec->get_index());
rel_sec->set_addr_align(0x4);
rel_sec->set_entry_size(writer.get_default_entry_size(ELFIO::SHT_REL));
rel_sec->set_link(sym_sec->get_index());
rel_sec->set_flags(ELFIO::SHF_ALLOC);
// Create relocation table writer
ELFIO::relocation_section_accessor rela(writer, rel_sec);
// Add relocation entry (adjust address at offset 11)
rela.add_entry(program.symbols[0].offset, label_sym, 26 /* ELFIO::R_RISCV_HI20 */);
rela.add_entry(program.symbols[0].offset, label_sym, 51 /* ELFIO::R_RISCV_RELAX */);
rela.add_entry(program.symbols[1].offset, label_sym, 27 /* ELFIO::R_RISCV_LO12_I */);
rela.add_entry(program.symbols[1].offset, label_sym, 51 /* ELFIO::R_RISCV_RELAX */);
rela.add_entry(program.symbols[2].offset, printf_sym, 18 /* ELFIO::R_RISCV_CALL */);
rela.add_entry(program.symbols[2].offset, printf_sym, 51 /* ELFIO::R_RISCV_RELAX */);
// Create ELF object file
writer.save(out_file);
return 0;
}
}