MCP is a simple macro processor. It performs text substitution and conditional evaluation.

Features

• Multiline recursive macros with eagerly expanded arguments.
• Expressions and conditionals.
• Dynamically scoped definitions.
• File inclusion with local scope.
• Customisable expansion conditions (prefix character).

Requirements

• C compiler
• make

Usage

• Compilation: make
• Invocation: mcp [options] [input_files]

MCP processes simple macros in input files or from standard input. It writes output from an input file to an output file with the same name, but with .out appended. When reading from standard input, it writes to standard output. If an input file has the .mcp extension, then the name of the output file is the name of the input file without .mcp.

You may pass - instead of an input file to indicate standard input.

Commands

There is a distinction between macros and defines, which is that defines are evaluated when defined and macros when called. Macro definitions are lexically scoped. See the &define, &local-define, &macro and &local-macro commands.

All commands are prefixed with &. This character may be changed with the &set-macro-char command. Macros and defines are referenced by &name& where name is the name of the macro or define to be expanded. The closing & may be omitted if the next character is a whitespace. In case of commands requiring arguments (like &define or &include) the whole command with its arguments must be placed on one line.

&&

Quotes &, expands to one &.

&#

Starts a comment, which extends to the end of the current line. Macro substitution is not performed in comments. Comments are not included in the output.

&<text>

Quotes text.

&\n

Quotes a newline. (\n above stands for a real newline).

&clear-defines

Undefines all local defines (but not macros).

&clear-macros

Undefines all local macros (but not defines).

&define name
&define name text

Defines a define named name which expands to text. If text is omitted then it is assumed to be the empty string. The name of a define cannot begin with the "macro character". The scope of the definition is the top-level file currently being parsed and all files included from the top-level file.

&local-define name
&local-define name text

The same as &define, but defines the define locally, i.e. only in the current macro.

&expand-non-prefix-on
&expand-non-prefix-off

Turns non-prefix expansion on/off. If it's on, then macros/defines are expanded even if not prefixed. The commands, however, must still be prefixed.

&if <expression>
   [block1]
&elseif <expr2>
   ...
&else
   [block2]
&endif

Outputs [block1] if <expression> is true (non-null, see &NULL), otherwise [block2]. The block is subject to text/macro expansion. Expressions may use defines prefixed with & and bare text strings.

Allowed operators:

• =, <=, >=: string comparisons
• ||, &&: disjunction and conjunction
• !: negation
• defined name: true if name is defined
• (, ): grouping

&ifdef name
&ifndef name

The same as above, but checks whether name is defined/undefined.

&include filename

Includes the file filename. The inclusion is treated like calling a macro (with respect to local/global scope; see &local-define).

&macro name
  ...
&endm

Defines a global macro. The difference between a macro and a define is that defines are evaluated when defined and macros when called. Macros may take arguments, e.g., &my_macro(arg1, arg2). Arguments are accesible via &argN, where N is the argument number. The number of arguments passed is accessible via &arg0.

&local-macro name
  ...
&endm

Defines a local macro. See &local-define.

&NULL

Expands to nothing. Sometimes useful in expressions.

&set-macro-char char

Sets the "macro character" to char instead of the default &. This should be called only once before processing any other commands (otherwise problems might occur).

&undefine name

Undefines the macro/define named name if it is defined, otherwise does nothing.

Options

-dDEFINE
-dDEFINE=VALUE
--define DEFINE
--define DEFINE=VALUE

Defines DEFINE globally, for all input files. See the &define command.

-n
--non-prefixed

Turn on non-prefixed expansion. See the &expand-non-prefixed-on command.

-i
--ignore-case

Makes MCP case-insensitive. By default it is case-sensitive.

-h
--help

Prints a help message and exits.

-v
--version

Print MCP version and exits.

--

Indicates the end of options.

Copyright and license

Copyright (C) 2006-2021 by Lukasz Czajka.

Distributed under the terms of GPL 2. See LICENSE.

Contains BSD-licensed hashtable code by Christopher Clark. See the hashtable directory.