1" VHDL indent ('93 syntax)
2" Language:    VHDL
3" Maintainer:  Gerald Lai <laigera+vim?gmail.com>
4" Version:     1.56
5" Last Change: 2010 Jun 29
6" URL:         http://www.vim.org/scripts/script.php?script_id=1450
7
8" only load this indent file when no other was loaded
9if exists("b:did_indent")
10  finish
11endif
12let b:did_indent = 1
13
14" setup indent options for local VHDL buffer
15setlocal indentexpr=GetVHDLindent()
16setlocal indentkeys=!^F,o,O,0(,0)
17setlocal indentkeys+==~begin,=~end\ ,=~end\	,=~is,=~select,=~when
18setlocal indentkeys+==~if,=~then,=~elsif,=~else
19setlocal indentkeys+==~case,=~loop,=~for,=~generate,=~record,=~units,=~process,=~block,=~function,=~component,=~procedure
20setlocal indentkeys+==~architecture,=~configuration,=~entity,=~package
21
22" constants
23" not a comment
24let s:NC = '\%(--.*\)\@<!'
25" end of string
26let s:ES = '\s*\%(--.*\)\=$'
27" no "end" keyword in front
28let s:NE = '\%(\<end\s\+\)\@<!'
29
30" option to disable alignment of generic/port mappings
31if !exists("g:vhdl_indent_genportmap")
32  let g:vhdl_indent_genportmap = 1
33endif
34
35" option to disable alignment of right-hand side assignment "<=" statements
36if !exists("g:vhdl_indent_rhsassign")
37  let g:vhdl_indent_rhsassign = 1
38endif
39
40" only define indent function once
41if exists("*GetVHDLindent")
42  finish
43endif
44
45function GetVHDLindent()
46  " store current line & string
47  let curn = v:lnum
48  let curs = getline(curn)
49
50  " find previous line that is not a comment
51  let prevn = prevnonblank(curn - 1)
52  let prevs = getline(prevn)
53  while prevn > 0 && prevs =~ '^\s*--'
54    let prevn = prevnonblank(prevn - 1)
55    let prevs = getline(prevn)
56  endwhile
57  let prevs_noi = substitute(prevs, '^\s*', '', '')
58
59  " default indent starts as previous non-comment line's indent
60  let ind = prevn > 0 ? indent(prevn) : 0
61  " backup default
62  let ind2 = ind
63
64  " indent:   special; kill string so it would not affect other filters
65  " keywords: "report" + string
66  " where:    anywhere in current or previous line
67  let s0 = s:NC.'\<report\>\s*".*"'
68  if curs =~? s0
69    let curs = ""
70  endif
71  if prevs =~? s0
72    let prevs = ""
73  endif
74
75  " indent:   previous line's comment position, otherwise follow next non-comment line if possible
76  " keyword:  "--"
77  " where:    start of current line
78  if curs =~ '^\s*--'
79    let pn = curn - 1
80    let ps = getline(pn)
81    if curs =~ '^\s*--\s' && ps =~ '--'
82      return indent(pn) + stridx(substitute(ps, '^\s*', '', ''), '--')
83    else
84      " find nextnonblank line that is not a comment
85      let nn = nextnonblank(curn + 1)
86      let ns = getline(nn)
87      while nn > 0 && ns =~ '^\s*--'
88        let nn = nextnonblank(nn + 1)
89        let ns = getline(nn)
90      endwhile
91      let n = indent(nn)
92      return n != -1 ? n : ind
93    endif
94  endif
95
96  " ****************************************************************************************
97  " indent:   align generic variables & port names
98  " keywords: "generic", "map", "port" + "(", provided current line is part of mapping
99  " where:    anywhere in previous 2 lines
100  " find following previous non-comment line
101  let pn = prevnonblank(prevn - 1)
102  let ps = getline(pn)
103  while pn > 0 && ps =~ '^\s*--'
104    let pn = prevnonblank(pn - 1)
105    let ps = getline(pn)
106  endwhile
107  if (curs =~ '^\s*)' || curs =~? '^\s*\%(\<\%(generic\|map\|port\)\>.*\)\@<!\S\+\s*\%(=>\s*\S\+\|:[^=]\@=\s*\%(\%(in\|out\|inout\|buffer\|linkage\)\>\|\w\+\s\+:=\)\)') && (prevs =~? s:NC.'\<\%(generic\|map\|port\)\s*(\%(\s*\w\)\=' || (ps =~? s:NC.'\<\%(generic\|map\|port\)'.s:ES && prevs =~ '^\s*('))
108    " align closing ")" with opening "("
109    if curs =~ '^\s*)'
110      return ind2 + stridx(prevs_noi, '(')
111    endif
112    let m = matchend(prevs_noi, '(\s*\ze\w')
113    if m != -1
114      return ind2 + m
115    else
116      if g:vhdl_indent_genportmap
117        return ind2 + stridx(prevs_noi, '(') + &sw
118      else
119        return ind2 + &sw
120      endif
121    endif
122  endif
123
124  " indent:   align conditional/select statement
125  " keywords: variable + "<=" without ";" ending
126  " where:    start of previous line
127  if prevs =~? '^\s*\S\+\s*<=[^;]*'.s:ES
128    if g:vhdl_indent_rhsassign
129      return ind2 + matchend(prevs_noi, '<=\s*\ze.')
130    else
131      return ind2 + &sw
132    endif
133  endif
134
135  " indent:   backtrace previous non-comment lines for next smaller or equal size indent
136  " keywords: "end" + "record", "units"
137  " where:    start of previous line
138  " keyword:  ")"
139  " where:    start of previous line
140  " keyword:  without "<=" + ";" ending
141  " where:    anywhere in previous line
142  " keyword:  "=>" + ")" ending, provided current line does not begin with ")"
143  " where:    anywhere in previous line
144  " _note_:   indent allowed to leave this filter
145  let m = 0
146  if prevs =~? '^\s*end\s\+\%(record\|units\)\>'
147    let m = 3
148  elseif prevs =~ '^\s*)'
149    let m = 1
150  elseif prevs =~ s:NC.'\%(<=.*\)\@<!;'.s:ES || (curs !~ '^\s*)' && prevs =~ s:NC.'=>.*'.s:NC.')'.s:ES)
151    let m = 2
152  endif
153
154  if m > 0
155    let pn = prevnonblank(prevn - 1)
156    let ps = getline(pn)
157    while pn > 0
158      let t = indent(pn)
159      if ps !~ '^\s*--' && (t < ind || (t == ind && m == 3))
160        " make sure one of these is true
161        " keywords: variable + "<=" without ";" ending
162        " where:    start of previous non-comment line
163        " keywords: "generic", "map", "port"
164        " where:    anywhere in previous non-comment line
165        " keyword:  "("
166        " where:    start of previous non-comment line
167        if m < 3 && ps !~? '^\s*\S\+\s*<=[^;]*'.s:ES
168          if ps =~? s:NC.'\<\%(generic\|map\|port\)\>' || ps =~ '^\s*('
169            let ind = t
170          endif
171          break
172        endif
173        let ind = t
174        if m > 1
175          " find following previous non-comment line
176          let ppn = prevnonblank(pn - 1)
177          let pps = getline(ppn)
178          while ppn > 0 && pps =~ '^\s*--'
179            let ppn = prevnonblank(ppn - 1)
180            let pps = getline(ppn)
181          endwhile
182          " indent:   follow
183          " keyword:  "select"
184          " where:    end of following previous non-comment line
185          " keyword:  "type"
186          " where:    start of following previous non-comment line
187          if m == 2
188            let s1 = s:NC.'\<select'.s:ES
189            if ps !~? s1 && pps =~? s1
190              let ind = indent(ppn)
191            endif
192          elseif m == 3
193            let s1 = '^\s*type\>'
194            if ps !~? s1 && pps =~? s1
195              let ind = indent(ppn)
196            endif
197          endif
198        endif
199        break
200      endif
201      let pn = prevnonblank(pn - 1)
202      let ps = getline(pn)
203    endwhile
204  endif
205
206  " indent:   follow indent of previous opening statement, otherwise -sw
207  " keyword:  "begin"
208  " where:    anywhere in current line
209  if curs =~? s:NC.'\<begin\>'
210    let ind = ind - &sw
211    " find previous opening statement of
212    " keywords: "architecture", "block", "entity", "function", "generate", "procedure", "process"
213    let s2 = s:NC.s:NE.'\<\%(architecture\|block\|entity\|function\|generate\|procedure\|process\)\>'
214    if (curs !~? s2.'.*'.s:NC.'\<begin\>.*'.s:ES && prevs =~? s2) || m == 1
215      let ind = ind + &sw
216    endif
217    return ind
218  endif
219
220  " indent:   +sw if previous line is previous opening statement
221  " keywords: "record", "units"
222  " where:    anywhere in current line
223  if curs =~? s:NC.s:NE.'\<\%(record\|units\)\>'
224    " find previous opening statement of
225    " keyword: "type"
226    let s3 = s:NC.s:NE.'\<type\>'
227    if curs !~? s3.'.*'.s:NC.'\<\%(record\|units\)\>.*'.s:ES && prevs =~? s3
228      let ind = ind + &sw
229    endif
230    return ind
231  endif
232
233  " ****************************************************************************************
234  " indent:   0
235  " keywords: "architecture", "configuration", "entity", "library", "package"
236  " where:    start of current line
237  if curs =~? '^\s*\%(architecture\|configuration\|entity\|library\|package\)\>'
238    return 0
239  endif
240
241  " indent:   maintain indent of previous opening statement
242  " keyword:  "is"
243  " where:    start of current line
244  " find previous opening statement of
245  " keywords: "architecture", "block", "configuration", "entity", "function", "package", "procedure", "process", "type"
246  if curs =~? '^\s*\<is\>' && prevs =~? s:NC.s:NE.'\<\%(architecture\|block\|configuration\|entity\|function\|package\|procedure\|process\|type\)\>'
247    return ind2
248  endif
249
250  " indent:   maintain indent of previous opening statement
251  " keyword:  "then"
252  " where:    start of current line
253  " find previous opening statement of
254  " keywords: "elsif", "if"
255  if curs =~? '^\s*\<then\>' && prevs =~? s:NC.'\%(\<elsif\>\|'.s:NE.'\<if\>\)'
256    return ind2
257  endif
258
259  " indent:   maintain indent of previous opening statement
260  " keyword:  "generate"
261  " where:    start of current line
262  " find previous opening statement of
263  " keywords: "for", "if"
264  if curs =~? '^\s*\<generate\>' && prevs =~? s:NC.s:NE.'\%(\%(\<wait\s\+\)\@<!\<for\|\<if\)\>'
265    return ind2
266  endif
267
268  " indent:   +sw
269  " keywords: "block", "process"
270  " removed:  "begin", "case", "elsif", "if", "loop", "record", "units", "while"
271  " where:    anywhere in previous line
272  if prevs =~? s:NC.s:NE.'\<\%(block\|process\)\>'
273    return ind + &sw
274  endif
275
276  " indent:   +sw
277  " keywords: "architecture", "configuration", "entity", "package"
278  " removed:  "component", "for", "when", "with"
279  " where:    start of previous line
280  if prevs =~? '^\s*\%(architecture\|configuration\|entity\|package\)\>'
281    return ind + &sw
282  endif
283
284  " indent:   +sw
285  " keyword:  "select"
286  " removed:  "generate", "is", "=>"
287  " where:    end of previous line
288  if prevs =~? s:NC.'\<select'.s:ES
289    return ind + &sw
290  endif
291
292  " indent:   +sw
293  " keyword:  "begin", "loop", "record", "units"
294  " where:    anywhere in previous line
295  " keyword:  "component", "else", "for"
296  " where:    start of previous line
297  " keyword:  "generate", "is", "then", "=>"
298  " where:    end of previous line
299  " _note_:   indent allowed to leave this filter
300  if prevs =~? s:NC.'\%(\<begin\>\|'.s:NE.'\<\%(loop\|record\|units\)\>\)' || prevs =~? '^\s*\%(component\|else\|for\)\>' || prevs =~? s:NC.'\%('.s:NE.'\<generate\|\<\%(is\|then\)\|=>\)'.s:ES
301    let ind = ind + &sw
302  endif
303
304  " ****************************************************************************************
305  " indent:   -sw
306  " keywords: "when", provided previous line does not begin with "when", does not end with "is"
307  " where:    start of current line
308  let s4 = '^\s*when\>'
309  if curs =~? s4
310    if prevs =~? s:NC.'\<is'.s:ES
311      return ind
312    elseif prevs !~? s4
313      return ind - &sw
314    else
315      return ind2
316    endif
317  endif
318
319  " indent:   -sw
320  " keywords: "else", "elsif", "end" + "block", "for", "function", "generate", "if", "loop", "procedure", "process", "record", "units"
321  " where:    start of current line
322  if curs =~? '^\s*\%(else\|elsif\|end\s\+\%(block\|for\|function\|generate\|if\|loop\|procedure\|process\|record\|units\)\)\>'
323    return ind - &sw
324  endif
325
326  " indent:   backtrace previous non-comment lines
327  " keyword:  "end" + "case", "component"
328  " where:    start of current line
329  let m = 0
330  if curs =~? '^\s*end\s\+case\>'
331    let m = 1
332  elseif curs =~? '^\s*end\s\+component\>'
333    let m = 2
334  endif
335
336  if m > 0
337    " find following previous non-comment line
338    let pn = prevn
339    let ps = getline(pn)
340    while pn > 0
341      if ps !~ '^\s*--'
342        "indent:   -2sw
343        "keywords: "end" + "case"
344        "where:    start of previous non-comment line
345        "indent:   -sw
346        "keywords: "when"
347        "where:    start of previous non-comment line
348        "indent:   follow
349        "keywords: "case"
350        "where:    start of previous non-comment line
351        if m == 1
352          if ps =~? '^\s*end\s\+case\>'
353            return indent(pn) - 2 * &sw
354          elseif ps =~? '^\s*when\>'
355            return indent(pn) - &sw
356          elseif ps =~? '^\s*case\>'
357            return indent(pn)
358          endif
359        "indent:   follow
360        "keyword:  "component"
361        "where:    start of previous non-comment line
362        elseif m == 2
363          if ps =~? '^\s*component\>'
364            return indent(pn)
365          endif
366        endif
367      endif
368      let pn = prevnonblank(pn - 1)
369      let ps = getline(pn)
370    endwhile
371    return ind - &sw
372  endif
373
374  " indent:   -sw
375  " keyword:  ")"
376  " where:    start of current line
377  if curs =~ '^\s*)'
378    return ind - &sw
379  endif
380
381  " indent:   0
382  " keywords: "end" + "architecture", "configuration", "entity", "package"
383  " where:    start of current line
384  if curs =~? '^\s*end\s\+\%(architecture\|configuration\|entity\|package\)\>'
385    return 0
386  endif
387
388  " indent:   -sw
389  " keywords: "end" + identifier, ";"
390  " where:    start of current line
391  "if curs =~? '^\s*end\s\+\w\+\>'
392  if curs =~? '^\s*end\%(\s\|;'.s:ES.'\)'
393    return ind - &sw
394  endif
395
396  " ****************************************************************************************
397  " indent:   maintain indent of previous opening statement
398  " keywords: without "generic", "map", "port" + ":" but not ":=" + "in", "out", "inout", "buffer", "linkage", variable & ":="
399  " where:    start of current line
400  if curs =~? '^\s*\%(\<\%(generic\|map\|port\)\>.*\)\@<!\S\+\s*:[^=]\@=\s*\%(\%(in\|out\|inout\|buffer\|linkage\)\>\|\w\+\s\+:=\)'
401    return ind2
402  endif
403
404  " return leftover filtered indent
405  return ind
406endfunction
407