error.1

<B>Digital的Unix操作系统VAX 4.2源码</B>

.\" SCCSID: @(#)error.1	8.2	12/3/90
.TH error 1
.SH Name
error \- analyze and disperse compiler error messages
.SH Syntax
.B error
[\fB\-n\fR] [\fB\-s\fR] [\fB\-q\fR] [\fB\-v\fR] [\fB\-t\fI suffixlist\fR\|] 
[\fB\-I\fI ignorefile\fR] [\|\fIname\fR\|]
.SH Description
.NXB "error command"
.NXB "error message" "viewing in source code"
The 
.PN error
command analyzes and optionally disperses the diagnostic error messages
produced by a number of compilers and language processors to the source
file and line where the errors occurred.  It permits error messages
and source code to be viewed simultaneously
without using multiple windows in a screen editor.
.PP
The
.PN error
command looks at the error messages,
either from the specified file \fIname\fR
or from the standard input.  It
attempts to determine the following:  which
language processor produced each error message,
to which source file and line number
the error message refers, and
if the error message is to be ignored or not.
It also inserts the error message into
the source file as a comment on the line preceding the one
where the error occurred.
.PP
Error messages that cannot be categorized by language processor
or content are not inserted into any file,
but are sent to the standard output.
The
.PN error
command touches source files only after all input has been read.
By specifying the
.B \-q
query option,
the user is asked to confirm any potentially
dangerous (such as touching a file) or verbose action.
.PP
If the
.B \-t
touch option and associated suffix list is given, 
.PN error
restricts itself to touching only those files with suffixes
in the suffix list.
Error also can be asked (by specifying
.B \-v)
to invoke 
.MS vi 1 
on the files in which error messages were inserted; this prevents
the need to remember the names of the files with errors.
.PP
The
.PN error
command is intended to be run
with its standard input
connected via a pipe to the error message source.
Some language processors put error messages
on their standard error file;
others put their messages on the standard output.
Hence, both error sources should be piped together into
.PN error .
For example, when using the \fIcsh\fP syntax,
.EX
make \-s lint |\|& error \-q \-v
.EE
.PP
analyzes all the error messages produced
by whatever programs
.PN make
runs when making lint.
.PP
The
.PN error
command knows about the error messages produced by the following:
.PN make ,
.PN cc ,
.PN cpp ,
.PN ccom ,
.PN as ,
.PN ld ,
.PN lint ,
.PN pi ,
.PN pc
and
.PN f77.
The
.PN error
command knows a standard format for error messages produced by
the language processors,
so it is sensitive to changes in these formats.
For all languages except 
.I Pascal,
error messages are restricted to be on one line.
Some error messages refer to more than one line in more than
one file.
The
.PN error
command duplicates the error message and inserts it at
all of the places referenced.
.PP
The
.PN error
command
does one of six things with error messages.
.TP 20
.I synchronize
Some language processors produce short errors describing
which file it is processing.
The
.PN error 
command uses these to determine the file name for languages that
don't include the file name in each error message.
These synchronization messages are consumed entirely by
.PN error .
.TP 20
.I discard
Error messages from
.PN lint
that refer to one of the two
.PN lint
libraries, /usr/lib/llib-lc and /usr/lib/llib-port are discarded,
to prevent accidently touching these libraries.
Again, these error messages are consumed entirely by
.PN error .
.TP 20
.I nullify
Error messages from
.PN lint
can be nullified if they refer to a specific function,
which is known to generate diagnostics which are not interesting.
Nullified error messages are not inserted into the source file,
but are written to the standard output.
The names of functions to ignore are taken from
either the file named 
.PN \&.errorrc
in the users's home directory, 
or from the file named by the
.B \-I
option.
If the file does not exist,
no error messages are nullified.
If the file does exist, there must be one function
name per line.
.TP 20
.I not file specific
Error messages that can't be discerned are grouped together,
and written to the standard output before any files are touched.
They will not be inserted into any source file.
.TP 20
.I file specific
Error message that refer to a specific file,
but to no specific line,
are written to the standard output when
that file is touched.
.TP 20
.I true errors
Error messages that can be intuited are candidates for
insertion into the file to which they refer.
.PP
Only true error messages are candidates for inserting into
the file they refer to.
Other error messages are consumed entirely by
.PN error
or are written to the standard output.
The
.PN error
command inserts the error messages into the source file on the line
preceding the line the language processor found in error.
Each error message is turned into a one line comment for the
language,
and is internally flagged
with the string ``###'' at
the beginning of the error,
and ``%%%'' at the end of the error.
This makes pattern searching for errors easier with an editor,
and allows the messages to be easily removed.
.PP
In addition, each error message contains the source line number
for the line to which the message refers.
A reasonably formatted source program can be recompiled
with the error messages still in it,
without having the error messages themselves cause future errors.
For poorly formatted source programs in free format languages,
such as C or Pascal,
it is possible to insert a comment into another comment,
which can wreak havoc with a future compilation.
To avoid this, programs with comments and source
on the same line should be formatted
so that language statements appear before comments.
.PP
The
.PN error
command catches interrupt and terminate signals,
and if in the insertion phase,
terminates what it is doing.
.SH Options
.NXR "error command" "options"
Options available with
.PN error
are the following:
.IP "\fB\-\|I\fI ignorefile\fR" 20
Ignore the functions listed in the specified file (next argument).
.IP \fB\-n\fR 
Does not
touch files and sends error messages to the
standard output.
.IP \fB\-q\fR 
Prompts before touching the source file.  
A ``y'' or ``n'' to the question is necessary to continue.
Absence of the
.B \-q
option implies that all referenced files
(except those referring to discarded error messages)
are to be touched.
.IP \fB\-S\fR 
Shows error in unsorted order from the error file.
.IP \fB\-s\fR 
Displays
.I statistics
for each error type.
.IP \fB\-T\fR 
Terse output.
.IP "\fB\-\|t\fI suffixlist\fR" 
Does not touch those files that match the specified suffix.
The suffix list is dot separated, and ``*'' wildcards work.
Thus the suffix list:
.IP
\&     ".c.y.foo*.h"
.IP
allows
.B error
to touch files ending with ``.c'', ``.y'', ``.foo*'' and ``.h''.
.IP \fB\-v\fR 
Invokes the 
.PN vi
editor on each file that had been touched.
.SH Restrictions
.NXR "error command" "restricted"
Opens the teletype directly to do user querying.
.PP
Source files with links make a new copy of the file with
only one link to it.
.PP
Changing a language processor's format of error messages
may cause 
.PN error
to not understand the error message.
.PP
The
.PN error
command, since it is purely mechanical,
does not filter out subsequent errors caused by `floodgating'
initiated by one syntactically trivial error.
.PP
Pascal error messages belong after the lines affected
(error puts them before).  The alignment of the `\||\|' marking
the point of error is also disturbed by
.PN error .
.PP
The
.PN error
command was designed for work on CRT's at reasonably high speed.
It does not work as well on slow speed terminals, and has never been
used on hard-copy terminals.
.SH Files
.TP 15
.PN \&~/.errorrc
function names to ignore for \fIlint\fP error messages
.TP
.PN /dev/tty
user's teletype
.NXE "error command"
.NXE "error message" "viewing in source code"