zabbo

I, like countless others, use vim’s quickfix mode to ease the pain of the compile-fix-compile cycle. vim parses the output of the build so that it can present a summary of errors and enable navigation between them.

sparse is a tool that knows how to find errors in C code that compilers like gcc don’t notice. It requires minimal annotation in the source but provides invaluable functionality, like warning when endian conversions are forgotten.

Which brings us to the point of this post. sparse spits out multi-line errors messages that vim doesn’t completely understand:

tests/btree-stress.c:121:55: warning: incorrect type in initializer (different base types)
tests/btree-stress.c:121:55: expected restricted unsigned long long [usertype] b_offset
tests/btree-stress.c:121:55: got long long [signed] [usertype] offset

vim doesn’t know that each of these error messages belong to the same error. It offers them to the user as three separate errors:

:clist
35 tests/btree-stress.c:121 col 55: warning: incorrect type in initializer (different base types)
36 tests/btree-stress.c:121 col 55: expected restricted unsigned long long [usertype] b_offset
37 tests/btree-stress.c:121 col 55: got long long [signed] [usertype] offset

This is irritating because to navigate past this error you have to know to navigate past the next three errors. This has been an irritating me for, I don’t know, years now. I finally sat down and spent an hour or so poisoning my brain with vim’s arcane configuration.

set efm^=%W%f:%l:%c:\ warning:\ %m,%C%f:%l:%c:\ \ \ \ %m,%Z%f:%l:%c:\ \ \ \ %m

et voila. Now vim considers those three error messages as coming from one error:

:clist
35 tests/btree-stress.c:121 col 55 warning: incorrect type in initializer (different base types) expected restricted unsigned long long [usertype] b_offset got long long [signed] [usertype] offset

I’m sure that format won’t catch all of sparse’s errors but it’ll easy to derive additional formats from it.

I’m also sure that I’m not the first to do this. It would be nice if the sparse guys shipped a sourcable .vimrc along with the tools.