" Vim indent file
" Language: Makefile
" Maintainer: Nikolai Weibull <[email protected]>
" Latest Revision: 2007-05-07

if exists("b:did_indent")
finish
endif
let b:did_indent = 1

setlocal indentexpr=GetMakeIndent()
setlocal indentkeys=!^F,o,O,<:>,=else,=endif
setlocal nosmartindent

if exists("*GetMakeIndent")
finish
endif

let s:comment_rx = '^\s*#'
let s:rule_rx = '^[^ \t#:][^#:]*:\{1,2}\%([^=:]\|$\)'
let s:continued_rule_rx = '^[^#:]*:\{1,2}\%([^=:]\|$\)'
let s:continuation_rx = '\\$'
let s:assignment_rx = '^\s*\h\w*\s*[+?]\==\s*\zs.*\\$'
let s:folded_assignment_rx = '^\s*\h\w*\s*[+?]\=='
" TODO: This needs to be a lot more restrictive in what it matches.
let s:just_inserted_rule_rx = '^\s*[^#:]\+:\{1,2}$'
let s:conditional_directive_rx = '^ *\%(ifn\=\%(eq\|def\)\|else\)\>'
let s:end_conditional_directive_rx = '^\s*\%(else\|endif\)\>'

function s:remove_continuation(line)
return substitute(a:line, s:continuation_rx, "", "")
endfunction

function GetMakeIndent()
" TODO: Should this perhaps be v:lnum -1?
" let prev_lnum = prevnonblank(v:lnum - 1)
let prev_lnum = v:lnum - 1
if prev_lnum == 0
return 0
endif
let prev_line = getline(prev_lnum)

let prev_prev_lnum = prev_lnum - 1
let prev_prev_line = prev_prev_lnum != 0 ? getline(prev_prev_lnum) : ""

" TODO: Deal with comments. In comments, continuations aren't interesting.
if prev_line =~ s:continuation_rx
if prev_prev_line =~ s:continuation_rx
return indent(prev_lnum)
elseif prev_line =~ s:rule_rx
return &sw
elseif prev_line =~ s:assignment_rx
call cursor(prev_lnum, 1)
if search(s:assignment_rx, 'W') != 0
return virtcol('.') - 1
else
" TODO: ?
return &sw
endif
else
" TODO: OK, this might be a continued shell command, so perhaps indent
" properly here? Leave this out for now, but in the next release this
" should be using indent/sh.vim somehow.
"if prev_line =~ '^\t' " s:rule_command_rx
" if prev_line =~ '^\s\+[@-]\%(if\)\>'
" return indent(prev_lnum) + 2
" endif
"endif
return indent(prev_lnum) + &sw
endif
elseif prev_prev_line =~ s:continuation_rx
let folded_line = s:remove_continuation(prev_prev_line) . ' ' . s:remove_continuation(prev_line)
let lnum = prev_prev_lnum - 1
let line = getline(lnum)
while line =~ s:continuation_rx
let folded_line = s:remove_continuation(line) . ' ' . folded_line
let lnum -= 1
let line = getline(lnum)
endwhile
let folded_lnum = lnum + 1
if folded_line =~ s:rule_rx
if getline(v:lnum) =~ s:rule_rx
return 0
else
return &ts
endif
else
" elseif folded_line =~ s:folded_assignment_rx
if getline(v:lnum) =~ s:rule_rx
return 0
else
return indent(folded_lnum)
endif
" else
" " TODO: ?
" return indent(prev_lnum)
endif
elseif prev_line =~ s:rule_rx
if getline(v:lnum) =~ s:rule_rx
return 0
else
return &ts
endif
elseif prev_line =~ s:conditional_directive_rx
return &sw
else
let line = getline(v:lnum)
if line =~ s:just_inserted_rule_rx
return 0
elseif line =~ s:end_conditional_directive_rx
return v:lnum - 1 == 0 ? 0 : indent(v:lnum - 1) - &sw
else
return v:lnum - 1 == 0 ? 0 : indent(v:lnum - 1)
endif
endif
endfunction