ObjectEmitter.cpp

#include "ObjectEmitter.h"

#include <llvm/IR/LegacyPassManager.h>
#include <llvm/Support/FileSystem.h>

void ObjectEmitter::emit() const {
  const std::filesystem::path objectFile = sourceFile->filePath.replace_extension("o");

  // Open file output stream
  std::error_code errorCode;
  llvm::raw_fd_ostream stream(objectFile.string(), errorCode, llvm::sys::fs::OF_None);
  if (errorCode)
    throw std::runtime_error("File '" + objectFile.string() + "' could not be opened");

  llvm::legacy::PassManager passManager;
  if (targetMachine->addPassesToEmitFile(passManager, stream, nullptr, llvm::CodeGenFileType::ObjectFile, false))
    throw std::runtime_error("Target machine can't emit a file of this type");

  // Emit object file
  passManager.run(llvmModule);
  stream.flush();
}

void ObjectEmitter::link() const {
  const std::filesystem::path objectFile = sourceFile->filePath.replace_extension("o");
#if OS_WINDOWS
  const std::filesystem::path outputFile = sourceFile->filePath.replace_extension("exe");
#else
  const std::filesystem::path outputFile = sourceFile->filePath.replace_extension("");
#endif

  const std::string linkerCmd = "clang -o " + outputFile.string() + " -static " + objectFile.string();
  const ExecResult result = exec(linkerCmd);
  if (!result.output.empty())
    std::runtime_error("Linker error: " + result.output);
}

ExecResult ObjectEmitter::exec(const std::string &cmd) const {
  FILE *pipe = popen(cmd.c_str(), "r");
  assert(pipe);
  char buffer[128];
  std::stringstream result;
  while (!feof(pipe)) {
    if (fgets(buffer, 128, pipe) != nullptr)
      result << buffer;
  }
  int exitCode = pclose(pipe) / 256;
  return {result.str(), exitCode};
}