error - analyze and disperse compiler error messages
error [ -n ] [ -s ] [ -q ] [ -v ] [ -t suffixlist ] [ -I ignorefile ] [ name ]
Error 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 can replace the painful, traditional methods of scribbling abbreviations of
errors on paper, and permits error messages and source code to be viewed simultaneously
without machinations of multiple windows in a screen editor.
Error looks at the error messages, either from the specified file name or from the stan-
dard input, and attempts to determine which language processor produced each error mes-
sage, determines the source file and line number to which the error message refers, deter-
mines if the error message is to be ignored or not, and inserts the (possibly slightly
modified) error message into the source file as a comment on the line preceding to which
the line the error message refers. Error messages which can't be categorized by language
processor or content are not inserted into any file, but are sent to the standard output.
Error touches source files only after all input has been read. By specifying the -q query
option, the user is asked to confirm any potentially dangerous (such as touching a file)
or verbose action. Otherwise error proceeds on its merry business. If the -t touch
option and associated suffix list is given, error will restrict itself to touch only those
files with suffices in the suffix list. Error also can be asked (by specifying -v) to
invoke vi(1) on the files in which error messages were inserted; this obviates the need to
remember the names of the files with errors.
Error is intended to be run with its standard input connected via a pipe to the error mes-
sage 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 error. For example, when using the csh syntax,
make -s lint |& error -q -v
will analyze all the error messages produced by whatever programs make runs when making
Error knows about the error messages produced by: make, cc, cpp, ccom, as, ld, lint, pi,
pc, f77, and DEC Western Research Modula-2. Error knows a standard format for error mes-
sages produced by the language processors, so is sensitive to changes in these formats.
For all languages except Pascal, error messages are restricted to be on one line. Some
error messages refer to more than one line in more than one files; error will duplicate
the error message and insert it at all of the places referenced.
Error will do one of six things with error messages.
Some language processors produce short errors describing which file it is pro-
cessing. Error 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 error.
discard Error messages from lint that refer to one of the two lint libraries,
/usr/share/lint/llib-lc and /usr/share/lint/llib-port are discarded, to prevent
accidently touching these libraries. Again, these error messages are consumed
entirely by error.
nullify Error messages from 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 .errorrc in the users's home directory, or from the file named by the
-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.
not file specific
Error messages that can't be intuited are grouped together, and written to the
standard output before any files are touched. They will not be inserted into
any source file.
Error message that refer to a specific file, but to no specific line, are writ-
ten to the standard output when that file is touched.
Error messages that can be intuited are candidates for insertion into the file
to which they refer.
Only true error messages are candidates for inserting into the file they refer to. Other
error messages are consumed entirely by error or are written to the standard output.
Error 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. In addition, each
error message contains the source line number for the line the message refers to. A rea-
sonably 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 lan-
guage statements appear before comments.
Options available with error are:
-n Do not touch any files; all error messages are sent to the standard output.
-q The user is queried whether s/he wants to touch the file. A ``y'' or ``n'' to the
question is necessary to continue. Absence of the -q option implies that all refer-
enced files (except those referring to discarded error messages) are to be touched.
-v After all files have been touched, overlay the visual editor vi with it set up to
edit all files touched, and positioned in the first touched file at the first error.
If vi can't be found, try ex or ed from standard places.
-t Take the following argument as a suffix list. Files whose suffixes do not appear in
the suffix list are not touched. The suffix list is dot separated, and ``*'' wild-
cards work. Thus the suffix list:
allows error to touch files ending with ``.c'', ``.y'', ``.foo*'' and ``.y''.
-s Print out statistics regarding the error categorization. Not too useful.
Error catches interrupt and terminate signals, and if in the insertion phase, will orderly
terminate what it is doing.
~/.errorrc function names to ignore for lint error messages
/dev/tty user's teletype
Opens the teletype directly to do user querying.
Source files with links make a new copy of the file with only one link to it.
Changing a language processor's format of error messages may cause error to not understand
the error message.
Error, since it is purely mechanical, will not filter out subsequent errors caused by
`floodgating' initiated by one syntactically trivial error. Humans are still much better
at discarding these related errors.
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 error.
Error was designed for work on CRT's at reasonably high speed. It is less pleasant on
slow speed terminals, and has never been used on hardcopy terminals.
4th Berkeley Distribution October 21, 1996 ERROR(1)