Macros.swift

//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//

#if $Macros && hasAttribute(attached)

/// Specifies the module and type name for an externally-defined macro, which
/// must conform to the appropriate set of `Macro` protocols.
///
/// This macro can only be used to define other macros. For example:
///
///    macro stringify<T>(_ value: T) -> (T, String) =
///        #externalMacro(module: "ExampleMacros", type :"StringifyMacro")
///
/// Use of this macro in any other context is an error.
@freestanding(expression)
public macro externalMacro<T>(module: String, type: String) -> T =
  Builtin.ExternalMacro

// File and path-related information

/// Produces a unique identifier for the given source file, comprised of
/// the module and file name.
@freestanding(expression)
public macro fileID<T: ExpressibleByStringLiteral>() -> T =
  Builtin.FileIDMacro

/// Produces the complete path for the given source file.
@freestanding(expression)
public macro filePath<T: ExpressibleByStringLiteral>() -> T =
  Builtin.FilePathMacro

/// Produces either the result of `#filePath` or `#file`, depending
/// on whether concise file paths (SE-0274) are enabled.
@freestanding(expression)
public macro file<T: ExpressibleByStringLiteral>() -> T =
  Builtin.FileMacro

/// Produces a string representation of the current function name.
@freestanding(expression)
public macro function<T: ExpressibleByStringLiteral>() -> T =
  Builtin.FunctionMacro

/// Produces the line number at which the macro is expanded.
@freestanding(expression)
public macro line<T: ExpressibleByIntegerLiteral>() -> T =
  Builtin.LineMacro

/// Produces the column number at which the macro is expanded.
@freestanding(expression)
public macro column<T: ExpressibleByIntegerLiteral>() -> T =
  Builtin.ColumnMacro

/// Produces the shared object handle for the macro expansion location.
@freestanding(expression)
public macro dsohandle() -> UnsafeRawPointer = Builtin.DSOHandleMacro

/// Produce the given warning message during compilation.
@freestanding(declaration)
public macro warning(_ message: String) = Builtin.WarningMacro

/// Produce the given error message during compilation.
@freestanding(declaration)
public macro error(_ message: String) = Builtin.ErrorMacro

#endif