xref: /vim-8.2.3635/runtime/indent/make.vim (revision f193fffd)
1" Vim indent file
2" Language:         Makefile
3" Maintainer:       Nikolai Weibull <[email protected]>
4" Latest Revision:  2006-04-26
5
6if exists("b:did_indent")
7  finish
8endif
9let b:did_indent = 1
10
11setlocal indentexpr=GetMakeIndent()
12setlocal indentkeys=!^F,o,O
13setlocal nosmartindent
14
15if exists("*GetMakeIndent")
16  finish
17endif
18
19let s:rule_rx = '^[^ \t#:][^#:]*:\{1,2}\%([^=:]\|$\)'
20let s:continuation_rx = '\\$'
21let s:assignment_rx = '^\s*\h\w*\s*+\==\s*\zs.*\\$'
22
23" TODO: Deal with comments, string, and all kinds of other crap, e.g., defines.
24" TODO: Unwrap the whole logic of this function into something that requires a
25" lot less “return”s.
26function GetMakeIndent()
27  let lnum = v:lnum - 1
28  if lnum == 0
29    return 0
30  endif
31
32  " Figure out if the previous line is part of a rule or not.  If it is, then
33  " we more or less just indent by a ‘tabstop’, the previous’ lines indent, or
34  " remove all indent if the current line is itself a rule.  Also, if the line
35  " in question is part of a continuation-line set constituting the rule line
36  " itself, we indent by either a ‘shiftwidth’, if the line is the first in the
37  " continuation, or use the indent of the previous line, if not.
38  while lnum > 0
39    let line = getline(lnum)
40    if line[0] != "\t"
41      " We found a non-shell-command line, i.e., one that doesn’t have a
42      " leading tab.
43      if line =~ s:rule_rx
44        " The line looks like a rule line, so we must therefore either be inside a
45        " rule or we are a continuation line to that rule line.
46        if line =~ s:continuation_rx
47          " Ah, the rule line was continued, so look up the last continuation
48          " line that’s above the current line.
49          while line =~ s:continuation_rx && lnum < v:lnum
50            let lnum += 1
51            let line = getline(lnum)
52          endwhile
53          let lnum -= 1
54          let line = getline(lnum)
55        endif
56
57        " If the line that we’ve found is right above the current line, deal
58        " with it specifically.
59        if lnum == v:lnum - 1
60          " If it was continued, indent the current line by a shiftwidth, as it
61          " is the first to follow it.  Otherwise, depending on if the current
62          " line is a rule line, i.e, a rule line following another rule line,
63          " then indent to the left margin.  Otherwise, the current line is the
64          " first shell-command line in the rule, so indent by a ‘tabstop’
65          if line =~ s:continuation_rx
66            return &sw
67          else
68            return getline(v:lnum) =~ s:rule_rx ? 0 : &ts
69          endif
70        else
71          " If the previous line was a continuation line, then unless it was
72          " itself a part of a continuation line, add a ‘shiftwidth’’s worth of
73          " indent.  Otherwise, just use the indent of the previous line.
74          " Otherwise, if the previous line wasn’t a continuation line, check
75          " if the one above it was.  If it was then indent to whatever level
76          " the “owning” line had.  Otherwise, indent to the previous line’s
77          " level.
78          let lnum = v:lnum - 1
79          let line = getline(lnum)
80          if line =~ s:continuation_rx
81            let pnum = v:lnum - 2
82            let pine = getline(pnum)
83            if pine =~ s:continuation_rx
84              return indent(lnum)
85            else
86              return indent(lnum) + &sw
87            endif
88          else
89            let lnum = v:lnum - 2
90            let line = getline(lnum)
91            if line =~ s:continuation_rx
92              while lnum > 0
93                if line !~ s:continuation_rx
94                  let lnum += 1
95                  let line = getline(lnum)
96                  break
97                endif
98                let lnum -= 1
99                let line = getline(lnum)
100              endwhile
101              " We’ve found the owning line.  Indent to it’s level.
102              return indent(lnum)
103            else
104              return indent(v:lnum - 1)
105            endif
106          endif
107        endif
108      endif
109
110      " The line wasn’t a rule line, so the current line is part of a series
111      " of tab-indented lines that don’t belong to any rule.
112      break
113    endif
114    let lnum -= 1
115  endwhile
116
117  " If the line before the one we are currently indenting ended with a
118  " continuation, then try to figure out what “owns” that line and indent
119  " appropriately.
120  let lnum = v:lnum - 1
121  let line = getline(lnum)
122  if line =~ s:continuation_rx
123    let indent = indent(lnum)
124    if line =~ s:assignment_rx
125      " The previous line is a continuation line that begins a variable-
126      " assignment expression, so set the indent to just beyond the whitespace
127      " following the assignment operator (‘=’).
128      call cursor(lnum, 1)
129      if search(s:assignment_rx, 'W') != 0
130        let indent = virtcol('.') - 1
131      endif
132    endif
133
134    " The previous line didn’t constitute an assignment, so just indent to
135    " whatever level it had.
136    return indent
137  endif
138
139  " If the line above the line above the current line ended was continued,
140  " then the line above the current line was part of a continued line.  Find
141  " the “owning” line and indent to its level.
142  let lnum = v:lnum - 2
143  let line = getline(lnum)
144  if line =~ s:continuation_rx
145    while lnum > 0
146      if line !~ s:continuation_rx
147        let lnum += 1
148        let line = getline(lnum)
149        break
150      endif
151      let lnum -= 1
152      let line = getline(lnum)
153    endwhile
154    " We’ve found the owning line.  Indent to it’s level.
155    return indent(lnum)
156  endif
157
158  " If nothing else caught on, then check if this line is a rule line.  If it
159  " is, indent it to the left margin.  Otherwise, simply use the indent of the
160  " previous line.
161  let line = getline(v:lnum)
162  if line =~ s:rule_rx
163    return 0
164  else
165    return indent(v:lnum - 1)
166  endif
167endfunction
168