1 1 The C Preprocessor 1 ****************** 1 1 The C preprocessor implements the macro language used to transform C, 1 C++, and Objective-C programs before they are compiled. It can also be 1 useful on its own. 1
1 · Overview · Header Files · Macros · Conditionals · Diagnostics · Line Control · Pragmas · Other Directives · Preprocessor Output · Traditional Mode · Implementation Details · Invocation · Environment Variables · GNU Free Documentation License · Index of Directives · Option Index · Concept Index 1 1 -- The Detailed Node Listing -- 1 1 Overview 1 · Character sets · Initial processing · Tokenization · The preprocessing language 1 1 Header Files 1 · Include Syntax · Include Operation · Search Path · Once-Only Headers · Alternatives to Wrapper #ifndef · Computed Includes · Wrapper Headers · System Headers 1 1 Macros 1 · Object-like Macros · Function-like Macros · Macro Arguments · Stringizing · Concatenation · Variadic Macros · Predefined Macros · Undefining and Redefining Macros · Directives Within Macro Arguments · Macro Pitfalls 1 1 Predefined Macros 1 · Standard Predefined Macros · Common Predefined Macros · System-specific Predefined Macros · C++ Named Operators 1 1 Macro Pitfalls 1 · Misnesting · Operator Precedence Problems · Swallowing the Semicolon · Duplication of Side Effects · Self-Referential Macros · Argument Prescan · Newlines in Arguments 1 1 Conditionals 1 · Conditional Uses · Conditional Syntax · Deleted Code 1 1 Conditional Syntax 1 · Ifdef · If · Defined · Else · Elif 1 1 Implementation Details 1 · Implementation-defined behavior · Implementation limits · Obsolete Features 1 1 Obsolete Features 1 · Obsolete Features 1 1 1 Copyright (C) 1987-2018 Free Software Foundation, Inc. 1 1 Permission is granted to copy, distribute and/or modify this document 1 under the terms of the GNU Free Documentation License, Version 1.3 or 1 any later version published by the Free Software Foundation. A copy of 1 the license is included in the section entitled "GNU Free Documentation 1 License". 1 1 This manual contains no Invariant Sections. The Front-Cover Texts 1 are (a) (see below), and the Back-Cover Texts are (b) (see below). 1 1 (a) The FSF's Front-Cover Text is: 1 1 A GNU Manual 1 1 (b) The FSF's Back-Cover Text is: 1 1 You have freedom to copy and modify this GNU Manual, like GNU 1 software. Copies published by the Free Software Foundation raise funds 1 for GNU development. 1