.\" Copyright (c) 1985, 1991, 1993 .\" The Regents of the University of California. All rights reserved. .\" Copyright (c) 2002 - 2005 Tony Finch <email@example.com>. All rights reserved. .\" .\" This code is derived from software contributed to Berkeley by .\" Dave Yost. It was rewritten to support ANSI C by Tony Finch. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" @(#)unifdef.1 8.2 (Berkeley) 4/1/94 .\" $dotat: things/unifdef.1,v 1.51 2005/03/08 12:39:01 fanf2 Exp $ .\" $FreeBSD: src/usr.bin/unifdef/unifdef.1,v 1.25 2008/05/02 16:23:47 hrs Exp $ .\" .Dd September 24, 2002 .Dt UNIFDEF 1 .Os .Sh NAME .Nm unifdef , unifdefall .Nd remove preprocessor conditionals from code .Sh SYNOPSIS .Nm .Op Fl cdeklnst .Op Fl I Ns Ar path .Op Fl D Ns Ar sym Ns Op = Ns Ar val .Op Fl U Ns Ar sym .Op Fl iD Ns Ar sym Ns Op = Ns Ar val .Op Fl iU Ns Ar sym .Ar ... .Op Ar file .Nm unifdefall .Op Fl I Ns Ar path .Ar ... .Ar file .Sh DESCRIPTION The .Nm utility selectively processes conditional .Xr cpp 1 directives. It removes from a file both the directives and any additional text that they specify should be removed, while otherwise leaving the file alone. .Pp The .Nm utility acts on .Ic #if , #ifdef , #ifndef , #elif , #else , and .Ic #endif lines, and it understands only the commonly-used subset of the expression syntax for .Ic #if and .Ic #elif lines. It handles integer values of symbols defined on the command line, the .Fn defined operator applied to symbols defined or undefined on the command line, the operators .Ic \&! , < , > , <= , >= , == , != , && , || , and parenthesized expressions. Anything that it does not understand is passed through unharmed. It only processes .Ic #ifdef and .Ic #ifndef directives if the symbol is specified on the command line, otherwise they are also passed through unchanged. By default, it ignores .Ic #if and .Ic #elif lines with constant expressions, or they may be processed by specifying the .Fl k flag on the command line. .Pp The .Nm utility also understands just enough about C to know when one of the directives is inactive because it is inside a comment, or affected by a backslash-continued line. It spots unusually-formatted preprocessor directives and knows when the layout is too odd to handle. .Pp A script called .Nm unifdefall can be used to remove all conditional .Xr cpp 1 directives from a file. It uses .Nm Fl s and .Nm cpp Fl dM to get lists of all the controlling symbols and their definitions (or lack thereof), then invokes .Nm with appropriate arguments to process the file. .Pp Available options: .Pp .Bl -tag -width indent -compact .It Fl D Ns Ar sym Ns Op = Ns Ar val Specify that a symbol is defined, and optionally specify what value to give it for the purpose of handling .Ic #if and .Ic #elif directives. .Pp .It Fl U Ns Ar sym Specify that a symbol is undefined. If the same symbol appears in more than one argument, the last occurrence dominates. .Pp .It Fl c If the .Fl c flag is specified, then the operation of .Nm is complemented, i.e., the lines that would have been removed or blanked are retained and vice versa. .Pp .It Fl d Turn on printing of degugging messages. .Pp .It Fl e Because .Nm processes its input one line at a time, it cannot remove preprocessor directives that span more than one line. The most common example of this is a directive with a multi-line comment hanging off its right hand end. By default, if .Nm has to process such a directive, it will complain that the line is too obfuscated. The .Fl e option changes the behaviour so that, where possible, such lines are left unprocessed instead of reporting an error. .Pp .It Fl k Process .Ic #if and .Ic #elif lines with constant expressions. By default, sections controlled by such lines are passed through unchanged because they typically start .Dq Li "#if 0" and are used as a kind of comment to sketch out future or past development. It would be rude to strip them out, just as it would be for normal comments. .Pp .It Fl l Replace removed lines with blank lines instead of deleting them. .Pp .It Fl n Add .Li #line directives to the output following any deleted lines, so that errors produced when compiling the output file correspond to line numbers in the input file. .Pp .It Fl s Instead of processing the input file as usual, this option causes .Nm to produce a list of symbols that appear in expressions that .Nm understands. It is useful in conjunction with the .Fl dM option of .Xr cpp 1 for creating .Nm command lines. .Pp .It Fl t Disables parsing for C comments and line continuations, which is useful for plain text. .Pp .It Fl iD Ns Ar sym Ns Op = Ns Ar val .It Fl iU Ns Ar sym Ignore .Ic #ifdef Ns s . If your C code uses .Ic #ifdef Ns s to delimit non-C lines, such as comments or code which is under construction, then you must tell .Nm which symbols are used for that purpose so that it will not try to parse comments and line continuations inside those .Ic #ifdef Ns s . One specifies ignored symbols with .Fl iD Ns Ar sym Ns Oo = Ns Ar val Oc and .Fl iU Ns Ar sym similar to .Fl D Ns Ar sym Ns Op = Ns Ar val and .Fl U Ns Ar sym above. .Pp .It Fl I Ns Ar path Specifies to .Nm unifdefall an additional place to look for .Ic #include files. This option is ignored by .Nm for compatibility with .Xr cpp 1 and to simplify the implementation of .Nm unifdefall . .El .Pp The .Nm utility copies its output to .Em stdout and will take its input from .Em stdin if no .Ar file argument is given. .Pp The .Nm utility works nicely with the .Fl D Ns Ar sym option of .Xr diff 1 . .Sh EXIT STATUS The .Nm utility exits 0 if the output is an exact copy of the input, 1 if not, and 2 if in trouble. .Sh DIAGNOSTICS .Bl -item .It Too many levels of nesting. .It Inappropriate .Ic #elif , .Ic #else or .Ic #endif . .It Obfuscated preprocessor control line. .It Premature .Tn EOF (with the line number of the most recent unterminated .Ic #if ) . .It .Tn EOF in comment. .El .Sh SEE ALSO .Xr cpp 1 , .Xr diff 1 .Sh HISTORY The .Nm command appeared in .Bx 2.9 . .Tn ANSI\~C support was added in .Fx 4.7 . .Sh AUTHORS This implementation was originally written by .An Dave Yost Aq Dave@Yost.com . .An Tony Finch Aq firstname.lastname@example.org rewrote it to support .Tn ANSI\~C . .Sh BUGS Expression evaluation is very limited. .Pp Preprocessor control lines split across more than one physical line (because of comments or backslash-newline) cannot be handled in every situation. .Pp Trigraphs are not recognized. .Pp There is no support for symbols with different definitions at different points in the source file. .Pp The text-mode and ignore functionality does not correspond to modern .Xr cpp 1 behaviour.