metalint - a metaconfig unit consistency checker
metalint [ -hklsV ] [ -L dir ]
Metalint parses the units and performs some extensive consistency
checks, to make sure the whole set is sound. Due to the relatively huge
amount of units available, it is becoming very difficult to maintain
the units manually, and an automated process can be of real help,
although not perfect.
Metalint operates from within your top level package directory and is
used to make sure your own private units are correctly relying on the
publicly available units. If you intensively develop new units, you
should run metalint on them before making them publicly available.
Metalint recognizes the following set of options:
-h Print a short usage description and exit.
-k Keep temporary .MT directory.
-l (not implemented yet) By default, metalint only reports
problems related to your own private units. This switch
directs metalint to also report problems in publicly
-s Silent mode.
-L dir Override default library location. Normally only useful
for metaconfig maintainers to locally check the units
being developped instead of the publicly available ones.
The dir specified is the one containing the units U
-V Print version number and exit.
The following diagnostics may be emitted by metalint:
"(?MAKE) ignoring duplicate dependency listing line."
More than one ?MAKE: line bearing dependencies was found in the
unit. There may be only one such line, although multiple ?MAKE
action lines may occur.
"(?MAKE) special unit ’Xxx’ should not be listed as made."
A special unit symbol (first letter capitalized) may only be
listed as made in the special unit itself. To suppress this
warning in legitimate cases, add a ’+’ in front of the offending
symbol (note that for non-special units, the ’+’ in this position
indicates an internal symbol which should not appear in the
"(?MAKE) ’+xxx’ is listed x times."
A conditional dependency is listed more than once. This is
"(?MAKE) ’xxx’ is listed x times."
A normal depdendency is listed more than once. Again, an harmless
"(?MAKE) ’xxx’ listed as both conditional and full dependency."
Symbol is listed as a normal dependency and as a conditional one.
Metaconfig will consider this as being a full dependency, but that
may not be what you initially wanted...
"(?Y) unknown layout directive ’xxx’."
Layout directives may only be one of top, default or bottom, but
case does not matter. An unknown directive is just ignored and
handled as if default had been specified.
"(?S) duplicate description for variable ’$xxx’."
Shell symbol is described more than once, and that will produce
two entries in the Glossary.
"(?S) variable ’$xxx’ is not listed on ?MAKE: line."
The unit describes a shell symbol entry which cannot be used
externally since not listed as a dependency.
"(?S) syntax error in ?S: construct."
"(?C) duplicate description for symbol ’XXX’."
C symbol is described more than once, and that will produce two
entries for it in the Glossary.
"(?C) syntax error in ?C: construct."
"(?H) symbol ’XXX’ was already defined."
Apparently, two ?H: lines are defining the same C symbol.
"(?H) variable ’$xxx’ not even listed on ?MAKE: line."
A variable is used, but not listed on the dependency line.
"(?H) section was already terminated by ’?H:.’."
There can be no more ?H: lines after the first ’?H:.’ marking the
end of that section.
"(?H) uncommon cpp line should be protected with ’?%<:’."
All ?H: lines that are recognized by metaconfig and thus metalint
have their inclusion in config.h automatically protected by a
suitable symbol if none is provided. However, unrecognized lines
must be protected with the ’?%<:’ sequence to avoid their
inclusion should the unit not be loaded in Configure.
"(?H) line should not be listed here but in ’?C:’."
Only cpp lines should appear in the ?H: section. If you have a
comment to put regarding the symbol, use ?C:. If you want to
comment a particular generation sequence, put them into ?X:
comment so that they don’t make it into config.h.
"(?H) constraint ’xxx’ is an unknown symbol."
All the leading ?sym: constraints on the ?H: lines should be a
valid shell or C symbol, defined in the unit.
"(?M) syntax error in ?M: construct."
"(?M) symbol ’xxx’ already listed on a ?M: line in ’yyy’."
A magic definition for symbol xxx is attempted, but another one
was already provided in unit yyy.
"(?V) visible declaration in non-special unit ignored."
Visible declarations (?V: lines) may only appear in special units.
Otherwise, they are meaningless.
"(?V) wanted variable ’$xxx’ made visible."
A wanted variable (described as a dependency on the ?MAKE: line)
cannot be made visible since that does not make any sense: the
unit cannot depend on it and then advertise it as being locally
"(?V) defined variable ’$xxx’ made visible."
A defined variable (listed as made on the ?MAKE: line) cannot be
made visible, since it could as well be directly wanted in another
"(?V) variable ’$xxx’ already made visible by unit yyy."
Inconsistent declaration: two units are making one single symbol
"(?V) variable ’$xxx’ already read-write visible in yyy."
The variable was already made visible as read-write by another
"(?V) variable ’$xxx’ already read-only visible in yyy."
The variable was already made visible as read-only by another
"(?W) variable ’$xxx’ already wanted."
Variable is already wanted, there is no need to explicitely ask
for it here.
"(?W) variable ’$xxx’ also locally defined."
A wanted variable would conflict with a locally defined variable
and could result in getting a garbage value.
"(?W) variable ’$xxx’ already listed on a ?W: line in ’yyy’."
The variable in the shell symbol section of a ?W: line can only
appear in one unit.
"(?F) produced file ’xxx’ mutiply declared."
The file is listed more than once on the ?F: line, under the same
name. This does not appear when declaring both a private UU file
and a public file with the same name, for instance.
"(?F) UU file in non-special unit ignored."
Private UU files (i.e. files like the myread script created for
later perusal by Configure) may only be created in special units.
Exceptions allowed if the ?F: line is preceded by a proper ?LINT:
"(?T) temporary symbol ’$xxx’ multiply declared."
"directive should come after ?MAKE declarations."
The directive listed between () at the beginning of this message
should really come after the ?MAKE: lines. You must reorder the
unit or metalint will not be able to properly diagnose problems.
"control sequence ’?XXX:’ ignored within body."
Attempt to use a control line other than ?X: or ?LINT: in the unit
body, which should be only shell code
"variable ’$xxx’ is changed."
A variable listed as wanted in the dependency line is changed.
Such a variable should be read-only for the unit. Use the change
lint hint to suppress this message in pathological cases.
"no ?MAKE: line describing dependencies."
Every unit should have a dependency line, or it will be silently
ignored by metaconfig. This message is suppressed by a ?LINT:
"first body line should be a general ’: description’."
The very first shell line of the unit that will be added to the
generated Configure script should hold a description of the unit’s
purpose, on a ’:’ line. There must be a space after the ’:’,
since it is interpreted by the shell, and the description should
avoid meta-characters like ’(’ or ’>’ unless the whole string is
quoted. This message is suppressed by a ?LINT: nocomment hint.
"missing space after ’:’ to make it a comment."
A line starting by ’:’ is interpreted by the shell but will be
ignored. There must be a space after the ’:’ though, or the shell
will try to execute an unknown command...
"found unquoted meta-character > on comment line."
A line starting by ’:’ is interpreted by the shell but will be
ignored. This means that meaningful meta-characters such as ’(’
or ’>’ must be quoted or escaped with a leading backslash.
"found dangling quote on ’:’ comment line."
An unclosed single or double quote was spotted on a ’:’ comment
line. Since those lines are interpreted by the shell, albeit
ignored, all quotes must match perfectly.
"not ending with a blank line."
Since all units are gathered together to form one big script, it
is recommended (hence enforced by metalint) that every unit file
end with an empty line.
"last line not ending with a new-line character."
This is merely intended to users whose editor does not always
append a new-line at the end of text files. Should not happen when
you use vi.
"symbol ’$xxx’ was not described."
The shell symbol defined by this unit was not documented. Use the
describe lint hint to suppress this message.
"C symbol ’XXX’ was not described."
The C symbol defined by this unit was not documented. Use the
known lint hint to suppress this message.
"C symbol ’XXX’ was not defined by any ?H: line."
A C symbol was advertised by never defined, hence it cannot appear
in the config.h file and is therefore useless...
"variable ’$xxx’ should have been set."
A variable listed on the make line as made by the unit was not set
by the shell code body. Use the set lint hint to suppress this
message in pathological cases.
"unused dependency variable ’$xxx’."
Apparently no usage is made from a shell variable. Use the change
or use lint hints (depending on the situation) to suppress this
"unused conditional variable ’$xxx’.
Apparently no usage is made from this conditional dependency. The
change or use lint hints can be used to suppress this message.
"unused temporary variable ’$xxx’."
A variable declared as temporary in a ?T: line is not used. The
use lint hint will fool metalint into thinking it’s indeed used.
"unknown control sequence ’?XXX:’."
Attempt to use an unknown control sequence.
"unknown LINT request ’false’ ignored."
An unknown ?LINT: tag was used. All such tags must be spelled out
"symbol ’$xxx’ has no default value."
A symbol used as a conditional dependency in some unit has no
default value set by a ?D: line.
"stale ?MAKE: dependency ’xxx’."
Unit lists a symbol as a dependency, but that symbol is otherwise
unknown, i.e. never appears as made by any other unit.
"symbol ’$xxx’ missing from ?MAKE."
A symbol used or defined was not listed as a dependency in the
"missing xxx from ?MAKE for visible ’$yyy’."
A symbol defined as visible by a special unit is used, but that
special unit is not part of the dependency line.
"stale ?M: dependency ’xxx’."
Magic line lists a C symbol as a dependency but that symbol is not
known by any unit.
"unknown symbol ’$xxx’."
I have no idea about what this symbol is. If the variable is
externally define, this warning can be suppresed via a proper
"read-only symbol ’$xxx’ is set."
A symbol that should be read-only is set by the unit’s shell code
"obsolete symbol ’xxx’ is used."
An obsolete symbol is used in the unit’s shell code.
"undeclared symbol ’$xxx’ is set."
The unit tries to set a shell variable which has not been
otherwise declared as made or as a temporary variable, or
"unclosed ?H: section."
The ?H: section was not terminated by a single ’?H:.’ line before
the body of the unit or the start of another ?C: section.
"C symbol ’xxx’ is defined in the following units:"
The C symbol is defined in more that one unit. Offending units are
"Shell symbol ’xxx’ is defined in the following units:"
A shell symbol is defined in more than one unit. Offending units
"Shell symbol ’xxx’ is altogether:"
A shell symbol is defined by some units, obsoleted by others and
used as a temporary.
"Shell symbol ’xxx’ is both defined and obsoleted:"
"Shell symbol ’xxx’ is both defined and used as temporary:"
"Shell symbol ’xxx’ obsoleted also used as temporary:"
"definition of ’$xxx’ not closed by ’?S:.’."
"definition of ’XXX’ not closed by ’?C:.’."
"magic definition of ’xxx’ not closed by ’?M:.’."
"variable ’$xxx’ is defined externally."
A variable defined externally (i.e. in another unit) is used,
without proper dependency information. Use the extern lint hint to
suppress this message.
"file ’xxx’ was not created."
A file listed as a private UU file is not created by the special
unit. Creation is detected by seing an explicit shell redirection
to the file, not by an implicit creation (such as a C compilation
would for instance). All special units should create only shell
scripts explicitely anyway so this message cannot be suppressed
via a lint hint.
"local file ’xxx’ may override the one set by ’unit.U’."
You are attempting to create a local file, but the special unit
creates one bearing the exact same name and should it be loaded
before within Configure, you would override that file. Change the
name of your local file.
"unused temporary file ’xxx’.
The file was declared on the ?F: line but does not appear to be
"mis-used temporary file ’xxx’.
A local temporary file has been declared on the ?F: line and is
used in a way that may not be the proper one. Indeed, all such
local files should be called with an explicit relative path, to
avoid PATH lookups which could get you another file.
"you might not always get file ’xxx’ from ’unit.U’."
You seem to be calling the specified file, but not by using an
explicit relative pathname. Relying on the PATH to find this file
is not safe. To fix this problem, call your file using somthing
"missing Unit from ?MAKE for private file ’xxx’."
You are using a private UU file without listing the special unit
that produces it in your dependency line. Add the unit to your
"unknown private file ’xxx’."
The file does not appear on any ?F: line; however it should.
"File ’xxx’ is defined in the following units:"
The listed units cannot seem to agree on who is defining the file.
"empty here-document name discouraged."
You should refrain from using empty names for here documents, as
metalint will not monitor those.
"unclosed here-document xxx started line x."
The opened here-document at line x was never closed in this unit.
This generally mean that when the unit is used, the generated
script will not work!
"spurious ’LINT xxx’ directive."
You have inserted a ?LINT: directive that is not used to shut-up
"Cycle found for:"
There is a dependency cycle found for the symbols listed. Only the
symbols involved in the cycle are listed.
An exerpt of the dependencies where the cycle was found is listed.
This may involve far more symbols than the previous message,
because metalint actually rescans the rules to emphasize the cycle
and stops whenever it has found one, i.e. it does not try to
minimize it (the cycle is found using another algorithm, which
unfortunately cannot spit it out but only say for sure there is
Metalint uses the following control lines, which are otherwise ignored
?V:read-only symbols:read-write symbols
This line should be used only in special units. It lists all the
shell variable defined by the unit which should not be used
directly as dependencies by other units: they must include this
special unit in their dependency list if they make use of any of
the symbols described here. Those can be viewed as exported
symbols which you inherit from when depending from the unit.
Symbols may be exported read-only or read-write.
This line serves two purposes: it is a metalint hint, and also a
placeholder for future jmake use. It must list three kind of
files: the temporary one which are created for a test, the private
UU ones created in the UU directory for later perusal, and the
public ones left in the root directory of the package. Temporary
files must be listed with a preceding ’!’ character (meaning "no!
they’re not re-used later!"), private UU files should be preceded
by a ’./’ (meaning: to use them, say ./file, not just file), and
public ones should be named as-is.
This line should list all the shell variables used as temporaries
within the unit’s body. This line should be kept accurate, and
prevents you from writing a unit defining a symbol which would be
used as a scratch variable in another unit...
Specifies a lint hint. The following keywords are available:
change shell variable ok to be changed
create persistent file ok to be created by non-
define shell variables listed are defined in this
describe listed shell variables are described by ?S:
extern variable known to be externally defined
empty unit file is empty and kept only as a
known listed C variables are described
nocomment unit file is special and may miss a leading ’:
nothere listed names are not here documents (e.g. "1
<< foo" in a C program)
set listed variables are set
use variables listed are used by this unit
unclosed listed names of here-documents are not closed
in this unit
usefile listed file is used (do not prepend name with
’!’ for temporary ones)
Harlan Stenn <email@example.com> wrote the first version, based on
Larry Wall’s metaconfig from dist 2.0.
Raphael Manfredi <firstname.lastname@example.org> rewrote it from scratch
for 3.0 with a few enhancements.
Public unit files
U/*.U Private unit files
where LIB is /usr/share/dist.
Version 3.5 PL0