<html lang="en"> <head> <title>Macro Pitfalls - The C Preprocessor</title> <meta http-equiv="Content-Type" content="text/html"> <meta name="description" content="The C Preprocessor"> <meta name="generator" content="makeinfo 4.13"> <link title="Top" rel="start" href="index.html#Top"> <link rel="up" href="Macros.html#Macros" title="Macros"> <link rel="prev" href="Directives-Within-Macro-Arguments.html#Directives-Within-Macro-Arguments" title="Directives Within Macro Arguments"> <link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> <!-- Copyright (C) 1987-2015 Free Software Foundation, Inc. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation. A copy of the license is included in the section entitled ``GNU Free Documentation License''. This manual contains no Invariant Sections. The Front-Cover Texts are (a) (see below), and the Back-Cover Texts are (b) (see below). (a) The FSF's Front-Cover Text is: A GNU Manual (b) The FSF's Back-Cover Text is: You have freedom to copy and modify this GNU Manual, like GNU software. Copies published by the Free Software Foundation raise funds for GNU development. --> <meta http-equiv="Content-Style-Type" content="text/css"> <style type="text/css"><!-- pre.display { font-family:inherit } pre.format { font-family:inherit } pre.smalldisplay { font-family:inherit; font-size:smaller } pre.smallformat { font-family:inherit; font-size:smaller } pre.smallexample { font-size:smaller } pre.smalllisp { font-size:smaller } span.sc { font-variant:small-caps } span.roman { font-family:serif; font-weight:normal; } span.sansserif { font-family:sans-serif; font-weight:normal; } --></style> </head> <body> <div class="node"> <a name="Macro-Pitfalls"></a> <p> Previous: <a rel="previous" accesskey="p" href="Directives-Within-Macro-Arguments.html#Directives-Within-Macro-Arguments">Directives Within Macro Arguments</a>, Up: <a rel="up" accesskey="u" href="Macros.html#Macros">Macros</a> <hr> </div> <h3 class="section">3.10 Macro Pitfalls</h3> <p><a name="index-problems-with-macros-72"></a><a name="index-pitfalls-of-macros-73"></a> In this section we describe some special rules that apply to macros and macro expansion, and point out certain cases in which the rules have counter-intuitive consequences that you must watch out for. <ul class="menu"> <li><a accesskey="1" href="Misnesting.html#Misnesting">Misnesting</a> <li><a accesskey="2" href="Operator-Precedence-Problems.html#Operator-Precedence-Problems">Operator Precedence Problems</a> <li><a accesskey="3" href="Swallowing-the-Semicolon.html#Swallowing-the-Semicolon">Swallowing the Semicolon</a> <li><a accesskey="4" href="Duplication-of-Side-Effects.html#Duplication-of-Side-Effects">Duplication of Side Effects</a> <li><a accesskey="5" href="Self_002dReferential-Macros.html#Self_002dReferential-Macros">Self-Referential Macros</a> <li><a accesskey="6" href="Argument-Prescan.html#Argument-Prescan">Argument Prescan</a> <li><a accesskey="7" href="Newlines-in-Arguments.html#Newlines-in-Arguments">Newlines in Arguments</a> </ul> </body></html>