llvm-project/lld/Common/ErrorHandler.cpp

//===- ErrorHandler.cpp ---------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#include "lld/Common/ErrorHandler.h"

#include "lld/Common/Threads.h"

#include "llvm/ADT/Twine.h"
#include "llvm/IR/DiagnosticInfo.h"
#include "llvm/IR/DiagnosticPrinter.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/raw_ostream.h"
#include <mutex>

#if !defined(_MSC_VER) && !defined(__MINGW32__)
#include <unistd.h>
#endif

using namespace llvm;
using namespace lld;

// The functions defined in this file can be called from multiple threads,
// but outs() or errs() are not thread-safe. We protect them using a mutex.
static std::mutex mu;

// Prints "\n" or does nothing, depending on Msg contents of
// the previous call of this function.
static void newline(raw_ostream *errorOS, const Twine &msg) {
  // True if the previous error message contained "\n".
  // We want to separate multi-line error messages with a newline.
  static bool flag;

  if (flag)
    *errorOS << "\n";
  flag = StringRef(msg.str()).contains('\n');
}

ErrorHandler &lld::errorHandler() {
  static ErrorHandler handler;
  return handler;
}

void lld::exitLld(int val) {
  // Delete any temporary file, while keeping the memory mapping open.
  if (errorHandler().outputBuffer)
    errorHandler().outputBuffer->discard();

  // Dealloc/destroy ManagedStatic variables before calling
  // _exit(). In a non-LTO build, this is a nop. In an LTO
  // build allows us to get the output of -time-passes.
  llvm_shutdown();

  outs().flush();
  errs().flush();
  _exit(val);
}

void lld::diagnosticHandler(const DiagnosticInfo &di) {
  SmallString<128> s;
  raw_svector_ostream os(s);
  DiagnosticPrinterRawOStream dp(os);
  di.print(dp);
  switch (di.getSeverity()) {
  case DS_Error:
    error(s);
    break;
  case DS_Warning:
    warn(s);
    break;
  case DS_Remark:
  case DS_Note:
    message(s);
    break;
  }
}

void lld::checkError(Error e) {
  handleAllErrors(std::move(e),
                  [&](ErrorInfoBase &eib) { error(eib.message()); });
}

void ErrorHandler::print(StringRef s, raw_ostream::Colors c) {
  *errorOS << logName << ": ";
  if (colorDiagnostics) {
    errorOS->changeColor(c, true);
    *errorOS << s;
    errorOS->resetColor();
  } else {
    *errorOS << s;
  }
}

void ErrorHandler::log(const Twine &msg) {
  if (verbose) {
    std::lock_guard<std::mutex> lock(mu);
    *errorOS << logName << ": " << msg << "\n";
  }
}

void ErrorHandler::message(const Twine &msg) {
  std::lock_guard<std::mutex> lock(mu);
  outs() << msg << "\n";
  outs().flush();
}

void ErrorHandler::warn(const Twine &msg) {
  if (fatalWarnings) {
    error(msg);
    return;
  }

  std::lock_guard<std::mutex> lock(mu);
  newline(errorOS, msg);
  print("warning: ", raw_ostream::MAGENTA);
  *errorOS << msg << "\n";
}

void ErrorHandler::error(const Twine &msg) {
  std::lock_guard<std::mutex> lock(mu);
  newline(errorOS, msg);

  if (errorLimit == 0 || errorCount < errorLimit) {
    print("error: ", raw_ostream::RED);
    *errorOS << msg << "\n";
  } else if (errorCount == errorLimit) {
    print("error: ", raw_ostream::RED);
    *errorOS << errorLimitExceededMsg << "\n";
    if (exitEarly)
      exitLld(1);
  }

  ++errorCount;
}

void ErrorHandler::fatal(const Twine &msg) {
  error(msg);
  exitLld(1);
}