Operation modes:

-h, --help

print this help, then exit

-V, --version

print version number, then exit

-v, --verbose

verbosely report processing

-d, --debug

don't remove temporary files

-o, --output=FILE

save output in FILE (defaults to '-', stdout)

-f, --force

don't rely on cached values

-W, --warnings=CATEGORY

report the warnings falling in CATEGORY (comma-separated list accepted)

-l, --language=LANG

specify the set of M4 macros to use

-C, --cache=DIRECTORY

preserve results for future runs in DIRECTORY

--no-cache

disable the cache

-m, --mode=OCTAL

change the non trace output file mode (0666)

-M, --melt

don't use M4 frozen files

Languages include:

'Autoconf'

create Autoconf configure scripts

'Autotest'

create Autotest test suites

'M4sh'

create M4sh shell scripts

'M4sugar'

create M4sugar output

Warning categories are:

cross

cross compilation issues

gnu

GNU coding standards (default in gnu and gnits modes)

obsolete

obsolete features or constructions (default)

override

user redefinitions of Automake rules or variables

portability

portability issues (default in gnu and gnits modes)

portability-recursive

nested Make variables (default with -Wportability)

extra-portability

extra portability issues related to obscure tools

syntax

dubious syntactic constructs (default)

unsupported

unsupported or incomplete features (default)

-W also understands:

all

turn on all the warnings

none

turn off all the warnings

no-CATEGORY

turn off warnings in CATEGORY

error

treat all enabled warnings as errors

The environment variables 'M4' and 'WARNINGS' are honored.

Library directories:

-B, --prepend-include=DIR

prepend directory DIR to search path

-I, --include=DIR

append directory DIR to search path

Tracing:

-t, --trace=MACRO[:FORMAT]

report the MACRO invocations

-p, --preselect=MACRO

prepare to trace MACRO in a future run

Freezing:

-F, --freeze

produce an M4 frozen state file for FILES

FORMAT defaults to '$f:$l:$n:$%', and can use the following escapes:

$$

literal $

$f

file where macro was called

$l

line where macro was called

$d

nesting depth of macro call

$n

name of the macro

$NUM

argument NUM, unquoted and with newlines

$SEP@

all arguments, with newlines, quoted, and separated by SEP

$SEP*

all arguments, with newlines, unquoted, and separated by SEP

$SEP%

all arguments, without newlines, unquoted, and separated by SEP

SEP can be empty for the default (comma for @ and *, colon for %), a single character for that character, or {STRING} to use a string.