//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2015 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See http://swift.org/LICENSE.txt for license information
// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//

// Implementation Note: this file intentionally uses very LOW-LEVEL
// CONSTRUCTS, so that assert and fatal may be used liberally in
// building library abstractions without fear of infinite recursion.
//
// FIXME: We could go farther with this simplification, e.g. avoiding
// UnsafeMutablePointer

@transparent internal
func _isDebugAssertConfiguration() -> Bool {
  // The values for the assert_configuration call are:
  // 0: Debug
  // 1: Release
  // 2: Fast
  return Int32(Builtin.assert_configuration()) == 0
}

@transparent internal
func _isReleaseAssertConfiguration() -> Bool {
  // The values for the assert_configuration call are:
  // 0: Debug
  // 1: Release
  // 2: Fast
  return Int32(Builtin.assert_configuration()) == 1
}

@transparent internal
func _isFastAssertConfiguration() -> Bool {
  // The values for the assert_configuration call are:
  // 0: Debug
  // 1: Release
  // 2: Fast
  return Int32(Builtin.assert_configuration()) == 2
}

@asmname("swift_reportFatalErrorInFile")
func _reportFatalErrorInFile(
  prefix: UnsafePointer<UInt8>, prefixLength: UWord,
  message: UnsafePointer<UInt8>, messageLength: UWord,
  file: UnsafePointer<UInt8>, fileLength: UWord,
  line: UWord)

@asmname("swift_reportFatalError")
func _reportFatalError(
  prefix: UnsafePointer<UInt8>, prefixLength: UWord,
  message: UnsafePointer<UInt8>, messageLength: UWord)

@asmname("swift_reportUnimplementedInitializerInFile")
func _reportUnimplementedInitializerInFile(
  className: UnsafePointer<UInt8>, classNameLength: UWord,
  initName: UnsafePointer<UInt8>, initNameLength: UWord,
  file: UnsafePointer<UInt8>, fileLength: UWord,
  line: UWord, column: UWord)

@asmname("swift_reportUnimplementedInitializer")
func _reportUnimplementedInitializer(
  className: UnsafePointer<UInt8>, classNameLength: UWord,
  initName: UnsafePointer<UInt8>, initNameLength: UWord)

/// This function should be used only in the implementation of user-level
/// assertions.
@noreturn
func _assertionFailed(
  prefix: StaticString, message: StaticString,
  file: StaticString, line: UWord
) {
  _reportFatalErrorInFile(
    prefix.start, prefix.byteSize, message.start, message.byteSize,
    file.start, file.byteSize, line)

  Builtin.int_trap()
}

/// This function should be used only in the implementation of user-level
/// assertions.
@noreturn
func _assertionFailed(
  prefix: StaticString, message: String,
  file: StaticString, line: UWord
) {
  let messageUTF8 = message.nulTerminatedUTF8
  messageUTF8.withUnsafeBufferPointer {
    (messageUTF8) in
    _reportFatalErrorInFile(
      prefix.start, prefix.byteSize,
      messageUTF8.baseAddress, UWord(messageUTF8.count),
      file.start, file.byteSize, line)
  }

  Builtin.int_trap()
}

/// This function should be used only in the implementation of stdlib
/// assertions.
@transparent @noreturn internal
func _fatalErrorMessage(prefix: StaticString, message: StaticString,
                        file: StaticString, line: UWord) {
#if INTERNAL_CHECKS_ENABLED
  _reportFatalErrorInFile(
      prefix.start, prefix.byteSize, message.start, message.byteSize,
      file.start, file.byteSize, line)
#else
  _reportFatalError(prefix.start, prefix.byteSize,
                    message.start, message.byteSize)
#endif

  Builtin.int_trap()
}

/// Prints a fatal error message when a unimplemented initializer gets
/// called by the Objective-C runtime.
@transparent @noreturn internal
func _unimplemented_initializer(className: StaticString,
                                initName: StaticString = __FUNCTION__,
                                file: StaticString = __FILE__,
                                line: UWord = __LINE__,
                                column: UWord = __COLUMN__) {
  // This function is marked @transparent so that it is inlined into the caller
  // (the initializer stub), and, depending on the build configuration,
  // redundant parameter values (__FILE__ etc.) are eliminated, and don't leak
  // information about the user's source.

  if _isDebugAssertConfiguration() {
    _reportUnimplementedInitializerInFile(
        className.start, className.byteSize,
        initName.start, initName.byteSize,
        file.start, file.byteSize, line, column)
  } else {
    _reportUnimplementedInitializer(
        className.start, className.byteSize,
        initName.start, initName.byteSize)
  }

  Builtin.int_trap()
}