With vim's errorformat syntax, is there any way to use part of the message in filtering results?
As an example, some linker errors don't have anything explicit to distinguish them as an error on the line, other than the error itself:
/path/to/foo.cpp:42: undefined reference to 'UnimplementedFunction'
or
/path/to/foo.cpp:43: multiple definition of 'MultiplyDefinedFunction'
Using an errorformat of:
set efm=%f:%l:\ %m
would catch and display both of these correctly, but will falsely match many other cases (any line that starts with "[string]:[number]: ").
Or, explicitly specifying them both:
set efm=
set efm+=%f:%l:\ undefined\ reference\ to\ %m
set efm+=%f:%l:\ multiple\ definition\ of\ %m
removes the false positives, but the 'message' becomes far less useful -- the actual error is no longer included (just whatever is after it).
Is there anything in the syntax I'm missing to deal with this situation?
Ideally I'd like to be able to say something along the lines of:
set efm+=%f:%l:\ %{StartMessage}undefined\ reference\ to\ %*\\S%{EndMessage}
set efm+=%f:%l:\ %{StartMessage}multiple\ definition\ of\ %*\\S%{EndMessage}
... where everything matched between StartMessage and EndMessage is used as the error's message.
The errorformat can also use vim's regular expression syntax (albeit in a rather awkward way) which gives us a solution to the problem. We can use a non-capturing group and a zero-width assertion to require the presence of these signaling phrases without consuming them. This then allows the %m to pick them up. As plain regular expression syntax this zero-width assertion looks like:
\%(undefined reference\|multiple definition\)\#=
But in order to use it in efm we need to replace \ by %\ and % by %% and for use in a :set line we need to escape the backslashes, spaces and vertical bar so we finally have:
:set efm=%f:%l:\ %\\%%(undefined\ reference%\\\|multiple\ definitions%\\)%\\#=%m
With that the error file
/path/to/foo.cpp:42: undefined reference to 'UnimplementedFunction'
/path/to/foo.cpp:43: multiple definition of 'MultiplyDefinedFunction'
notafile:123: just some other text
comes out as the following in :copen:
/path/to/foo.cpp|42| undefined reference to 'UnimplementedFunction'
/path/to/foo.cpp|43| multiple definition of 'MultiplyDefinedFunction'
|| notafile:123: just some other text
I've been using sed to rewrite the output in cases like this where I want to get some arbitrary output that's not nessicarily homogenous into the quickfix window.
You could write make.sh that fires off make (or whatever your're using to build) and trims off stuff you're not concerned with:
make | sed '/undefined reference\|multiple definition/!d'
(Deletes lines not containing 'undefined reference' or 'multiple definition')
If that's going to get too unweildly because of the number of error strings you care about, you could do the inverse and just kill stuff you don't care about:
make | sed 's/some garbage\|other useless message//'
then :set makeprg=make.sh in vim
Related
I have an errorfile which I want to be read by vi. The format looks as if:
myfile.txt_:_80_:_3_:_this is the message: oh no!_:_comment
I.e., filename, lineno, colno, message and comment separated by "_:_". Note the trailing "comment" which I do not want to appear in the vi message. However, when I use the errorformat string
:set errorformat=%f_:_%l_:_%c_:_%m
The "%m" operator has greedy matching and matches everything, including the whole "_:_comment" portion. This is even true if I make the errorformat
:set errorformat=%f_:_%l_:_%c_:_%m_:_
I do not know how to customize what text "%m" matches. The vi documentation speaks that pretty much everything that is possible with vi regex should be possible, but I cannot figure out a way to make it work (the documentation is vague in this respect in my opinion).
How can I use an errorformat that ignores the last column field?
You can finish the format with the generic %s (for "search text"):
:set errorformat=%f_:_%l_:_%c_:_%m_:_%s
Note that this is relatively fragile. The following error, with several more _:_ separators:
myfile.txt_:_80_:_3_:_this is the message: oh no!_:_comment_:_foo_:_bar
would give you this message:
this is the message: oh no!_:_comment_:_foo
Improvement opportunities:
outside of Vim, make sure your errorfile is formatted in a non-ambiguous way,
in Vim, use a function to transform ambiguous error strings into non-ambiguous ones, see :help :cgetexpr.
I'm writing an errorformat string, and it works for the most part. My problem is that I have lines like this as the makeprg output:
Some text I want to show in the QuickFix window^M
Yes, the line ends with an spurious ^M character I want to remove. So, what I want in my QuickFix window is this, without the ^M character:
|| Some text I want to show in the QuickFix window
but I have this instead:
|| Some text I want to show in the QuickFix window^M
So far, this is the relevant part of my errorformat:
set errorformat=%+GSome text%m
I've tested, without success, something like this:
set errorformat=%+GSome text%m%-G^M%.%#
but it throws an error (not from the ^M which is a literal control-M char, not a caret followed by an M).
Obviously the solution is not using %G but I am at a loss here.
How can I remove the line ending character from the line here? And also, removing the initial || would be a plus, but I think it's impossible to do in Vim.
Thanks in advance!
Edited to make clearer how the input text looks
Well, turns out I found a solution, probably not very good but it works, using trial and error.
set errorformat=%\\(Some Text%*[^.]).%\\)%\\#=%m
That is, the solution is using the Vim pattern (regex) expressions within errorformat, which has a quite arcane look but works, together with %* to match unknown text on the rest of the line
The solution uses \#=, a zero-width match, and requires some kind of terminator for the line, which appears before the ^M character I want to ignore, and some kind of text appearing somewhere on the line to match that line and not others.
Probably there is a much better solution but this is the best I could do myself.
I tried reading :help errorformat and googling (mostly stackoverflow), but can't understand some of the patterns mentioned there:
%s - "specifies the text to search for to locate the error line. [...]"
um, first of all, trying to understand the sentence at all, where do I put the "text to search", after the %s? before it? or, I don't know, does it maybe taint the whole pattern? WTF?
secondly, what does this pattern actually do, how does it differ from regular text in a pattern, like some kinda set efm+=,foobar? the "foobar" here is for me also "text to search for"... :/
%+ - e.g. I I've seen something like that used in one question: %+C%.%#
does it mean the whole line will be appended to a %m used in an earlier/later multiline pattern? if yes, then what if there was not %.%# (== regexp .*), but, let's say, %+Ccont.: %.%# - would something like that work to capture only stuff after a cont.: string into the %m?
also, what's the difference between %C%.%# and %+C%.%# and %+G?
also, what's the difference between %A and %+A, or %E vs. %+E?
finally, an example for Python in :help errorformat-multi-line ends with the following characters: %\\#=%m -- WTF does the %\\#= mean?
I'd be very grateful for some help understanding this stuff.
Ah, errorformat, the feature everybody loves to hate. :)
Some meta first.
Some Vim commands (such as :make and :cgetexpr) take the output of a compiler and parse it into a quickfix list. errorformat is a string that describes how this parsing is done. It's a list of patterns, each pattern being a sort of hybrid between a regexp and a scanf(3) format. Some of these patterns match single lines in the compiler's output, others try to match multiple lines (%E, %A, %C etc.), others keep various states (%D, %X), others change the way parsing proceeds (%>), while yet others simply produce messages in the qflist (%G), or ignore lines in the input (%-G). Not all combinations make sense, and it's quite likely you won't figure out all details until you look at Vim' sources. shrug
You probably want to write errorformats using let &erf='...' rather than set erf=.... The syntax is much more human-friendly.
You can experiment with errorformat using cgetexpr. cgetexpr expects a list, which it interprets as the lines in the compiler's output. The result is a qflist (or a syntax error).
qflists are lists of errors, each error being a Vim "dictionary". See :help getqflist() for the (simplified) format.
Errors can identify a place in a file, they can be simple messages (if essential data that identifies a place is missing), and they can be valid or invalid (the invalid ones are essentially the leftovers from parsing).
You can display the current qflist with something like :echomsg string(getqflist()), or you can see it in a nice window with :copen (some important details are not shown in the window though). :cc will take you to the place of the first error (assuming the first error in qflist actually refers to an error in a file).
Now to answer your questions.
um, first of all, trying to understand the sentence at all, where do I put the "text to search", after the %s? before it?
You don't. %s reads a line from the compiler's output and translates it to pattern in the qflist. That's all it does. To see it at work, create a file efm.vim with this content:
let &errorformat ='%f:%s:%m'
cgetexpr ['efm.vim:" bar:baz']
echomsg string(getqflist())
copen
cc
" bar baz
" bar
" foo bar
Then run :so%, and try to understand what's going on. %f:%s:%m looks for three fields: a filename, the %s thing, and the message. The input line is efm.vim:" bar:baz, which is parsed into filename efm.vim (that is, current file), pattern ^\V" bar\$, and message baz. When you run :cc Vim tries to find a line matching ^\V" bar\$, and sends you there. That's the next-to-last line in the current file.
secondly, what does this pattern actually do, how does it differ from regular text in a pattern, like some kinda set efm+=,foobar?
set efm+=foobar %m will look for a line in the compiler's output starting with foobar, then assign the rest of the line to the message field in the corresponding error.
%s reads a line from the compiler's output and translates it to a pattern field in the corresponding error.
%+ - e.g. I I've seen something like that used in one question: %+C%.%#
does it mean the whole line will be appended to a %m used in an earlier/later multiline pattern?
Yes, it appends the content of the line matched by %+C to the message produced by an earlier (not later) multiline pattern (%A, %E, %W, or %I).
if yes, then what if there was not %.%# (== regexp .*), but, let's say, %+Ccont.: %.%# - would something like that work to capture only stuff after a cont.: string into the %m?
No. With %+Ccont.: %.%# only the lines matching the regexp ^cont\.: .*$ are considered, the lines not matching it are ignored. Then the entire line is appended to the previous %m, not just the part that follows cont.:.
also, what's the difference between %C%.%# and %+C%.%# and %+G?
%Chead %m trail matches ^head .* trail$, then appends only the middle part to the previous %m (it discards head and trail).
%+Chead %m trail matches ^head .* trail$, then appends the entire line to the previous %m (including head and trail).
%+Gfoo matches a line starting with foo and simply adds the entire line as a message in the qflist (that is, an error that only has a message field).
also, what's the difference between %A and %+A, or %E vs. %+E?
%A and %E start multiline patterns. %+ seems to mean "add the entire line being parsed to message, regardless of the position of %m".
finally, an example for Python in :help errorformat-multi-line ends with the following characters: %\\#=%m -- WTF does the %\\#= mean?
%\\#= translates to the regexp qualifier \#=, "matches preceding atom with zero width".
I am trying to set up my Vim environment, to be able to compile VHDL code by using the Cadence VHDL Compiler (ncvhdl). However, my errorformat string is not working properly. A typical ncvhdl error line is:
ncvhdl_p: *E,EXPBEG (tc_lg_and2-rtl-a.vhd,3|34): expecting the
reserved word 'BEGIN' [1.2].
I am setting the errorformat to:
set errorformat=ncvhdl_p:\ *E\\,%m\ (%f\\,%l\|%c)
Any hints out there?
Thanks!
This is what you want to do:
set errorformat=ncvhdl_p:\ \*%t\\,%.%#\ (%f\\,%l\\|%c):\ %m
The * character needs to be escaped.
Use %t to identify a single character indicating the error type (Error/Warning/Lint).
Use %.%# to skip a string, like .* in regular expressions.
For more information:
:help errorformat
The setting set makeprg=cat\ example.txt can be used as a quick way of testing the errorformat expression if example.txt contains a list of error lines copied from the command output.
Vims errorformat (for parsing compile/build errors) uses an arcane format from c for parsing errors.
Trying to set up an errorformat for nant seems almost impossible, I've tried for many hours and can't get it. I also see from my searches that alot of people seem to be having the same problem. A regex to solve this would take minutesto write.
So why does vim still use this format? It's quite possible that the C parser is faster but that hardly seems relevant for something that happens once every few minutes at most. Is there a good reason or is it just an historical artifact?
It's not that Vim uses an arcane format from C. Rather it uses the ideas from scanf, which is a C function. This means that the string that matches the error message is made up of 3 parts:
whitespace
characters
conversion specifications
Whitespace is your tabs and spaces. Characters are the letters, numbers and other normal stuff. Conversion specifications are sequences that start with a '%' (percent) character. In scanf you would typically match an input string against %d or %f to convert to integers or floats. With Vim's error format, you are searching the input string (error message) for files, lines and other compiler specific information.
If you were using scanf to extract an integer from the string "99 bottles of beer", then you would use:
int i;
scanf("%d bottles of beer", &i); // i would be 99, string read from stdin
Now with Vim's error format it gets a bit trickier but it does try to match more complex patterns easily. Things like multiline error messages, file names, changing directory, etc, etc. One of the examples in the help for errorformat is useful:
1 Error 275
2 line 42
3 column 3
4 ' ' expected after '--'
The appropriate error format string has to look like this:
:set efm=%EError\ %n,%Cline\ %l,%Ccolumn\ %c,%Z%m
Here %E tells Vim that it is the start of a multi-line error message. %n is an error number. %C is the continuation of a multi-line message, with %l being the line number, and %c the column number. %Z marks the end of the multiline message and %m matches the error message that would be shown in the status line. You need to escape spaces with backslashes, which adds a bit of extra weirdness.
While it might initially seem easier with a regex, this mini-language is specifically designed to help with matching compiler errors. It has a lot of shortcuts in there. I mean you don't have to think about things like matching multiple lines, multiple digits, matching path names (just use %f).
Another thought: How would you map numbers to mean line numbers, or strings to mean files or error messages if you were to use just a normal regexp? By group position? That might work, but it wouldn't be very flexible. Another way would be named capture groups, but then this syntax looks a lot like a short hand for that anyway. You can actually use regexp wildcards such as .* - in this language it is written %.%#.
OK, so it is not perfect. But it's not impossible either and makes sense in its own way. Get stuck in, read the help and stop complaining! :-)
I would recommend writing a post-processing filter for your compiler, that uses regular expressions or whatever, and outputs messages in a simple format that is easy to write an errorformat for it. Why learn some new, baroque, single-purpose language unless you have to?
According to :help quickfix,
it is also possible to specify (nearly) any Vim supported regular
expression in format strings.
However, the documentation is confusing and I didn't put much time into verifying how well it works and how useful it is. You would still need to use the scanf-like codes to pull out file names, etc.
They are a pain to work with, but to be clear: you can use regular expressions (mostly).
From the docs:
Pattern matching
The scanf()-like "%*[]" notation is supported for backward-compatibility
with previous versions of Vim. However, it is also possible to specify
(nearly) any Vim supported regular expression in format strings.
Since meta characters of the regular expression language can be part of
ordinary matching strings or file names (and therefore internally have to
be escaped), meta symbols have to be written with leading '%':
%\ The single '\' character. Note that this has to be
escaped ("%\\") in ":set errorformat=" definitions.
%. The single '.' character.
%# The single '*'(!) character.
%^ The single '^' character. Note that this is not
useful, the pattern already matches start of line.
%$ The single '$' character. Note that this is not
useful, the pattern already matches end of line.
%[ The single '[' character for a [] character range.
%~ The single '~' character.
When using character classes in expressions (see |/\i| for an overview),
terms containing the "\+" quantifier can be written in the scanf() "%*"
notation. Example: "%\\d%\\+" ("\d\+", "any number") is equivalent to "%*\\d".
Important note: The \(...\) grouping of sub-matches can not be used in format
specifications because it is reserved for internal conversions.
lol try looking at the actual vim source code sometime. It's a nest of C code so old and obscure you'll think you're on an archaeological dig.
As for why vim uses the C parser, there are plenty of good reasons starting with that it's pretty universal. But the real reason is that sometime in the past 20 years someone wrote it to use the C parser and it works. No one changes what works.
If it doesn't work for you the vim community will tell you to write your own. Stupid open source bastards.