Enhanced vim support.

This brings the utils/vim folder into a more vim-like format by moving
the syntax hightlighting files into a syntax subdirectory. It adds
some minimal settings that everyone should agree on to ftdetect/ftplugin and
features a new indentation plugin for .ll files.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235369 91177308-0d34-0410-b5e6-96231b3b80d8

utils/vim/README

@@ -1,33 +1,12 @@
 -*- llvm/utils/vim/README -*-
 
-These are syntax highlighting files for the VIM editor. Included are:
+This directory contains settings for the vim editor to work on llvm *.ll and
+tablegen *.td files. It comes with filetype detection rules in the (ftdetect),
+syntax highlighting (syntax), some minimal sensible default settings (ftplugin)
+and indentation plugins (indent).
 
-* llvm.vim
-
-  Syntax highlighting mode for LLVM assembly files. To use, copy `llvm.vim' to
-  ~/.vim/syntax and add this code to your ~/.vimrc :
-
-  augroup filetype
-    au! BufRead,BufNewFile *.ll     set filetype=llvm
-  augroup END
-
-* tablegen.vim
-
-  Syntax highlighting mode for TableGen description files. To use, copy
-  `tablegen.vim' to ~/.vim/syntax and add this code to your ~/.vimrc :
-
-  augroup filetype
-    au! BufRead,BufNewFile *.td     set filetype=tablegen
-  augroup END
-
-
-If you prefer, instead of making copies you can make symlinks from
-~/.vim/syntax/... to the syntax files in your LLVM source tree. Apparently
-this did not work with older versions of vim however, so if this doesn't
-work you may need to make actual copies of the files.
-
-Another option, if you do not already have a ~/.vim/syntax directory, is
-to symlink ~/.vim/syntax itself to llvm/utils/vim .
+To install copy all subdirectories to your $HOME/.vim or if you prefer create
+symlinks to the files here. Do not copy the vimrc file here it is only meant as an inspiration and starting point for those working on llvm c++ code.
 
 Note: If you notice missing or incorrect syntax highlighting, please contact
 <llvmbugs [at] cs.uiuc.edu>; if you wish to provide a patch to improve the

utils/vim/ftdetect/llvm.vim

@@ -0,0 +1 @@
+au BufRead,BufNewFile *.ll set filetype=llvm

utils/vim/ftdetect/tablegen.vim

@@ -0,0 +1 @@
+au BufRead,BufNewFile *.td set filetype=tablegen

utils/vim/ftplugin/llvm.vim

@@ -0,0 +1,11 @@
+" Vim filetype plugin file
+" Language: LLVM Assembly
+" Maintainer: The LLVM team, http://llvm.org/
+
+if exists("b:did_ftplugin")
+  finish
+endif
+let b:did_ftplugin = 1
+
+setlocal softtabstop=2 shiftwidth=2
+setlocal expandtab

utils/vim/ftplugin/tablegen.vim

@@ -0,0 +1,12 @@
+" Vim filetype plugin file
+" Language: LLVM TableGen
+" Maintainer: The LLVM team, http://llvm.org/
+
+if exists("b:did_ftplugin")
+  finish
+endif
+let b:did_ftplugin = 1
+
+setlocal matchpairs+=<:>
+setlocal softtabstop=2 shiftwidth=2
+setlocal expandtab

utils/vim/indent/llvm.vim

@@ -0,0 +1,72 @@
+" Vim indent file
+" Language:   llvm
+" Maintainer: The LLVM team, http://llvm.org/
+" What this indent plugin currently does:
+"  - If no other rule matches copy indent from previous non-empty,
+"    non-commented line
+"  - On '}' align the same as the line containing the matching '{'
+"  - If previous line ends with ':' increase indentation
+"  - If the current line ends with ':' indent at the same level as the
+"    enclosing '{'/'}' block
+" Stuff that would be nice to add:
+"  - Continue comments on next line
+"  - If there is an opening+unclosed parenthesis on previous line indent to that
+if exists("b:did_indent")
+  finish
+endif
+let b:did_indent = 1
+
+setlocal shiftwidth=2 expandtab
+
+setlocal indentkeys=0{,0},<:>,!^F,o,O,e
+setlocal indentexpr=GetLLVMIndent()
+
+if exists("*GetLLVMIndent")
+  finish
+endif
+
+function! FindOpenBracket(lnum)
+  call cursor(a:lnum, 1)
+  return searchpair('{', '', '}', 'bW')
+endfun
+
+function! GetLLVMIndent()
+  " On '}' align the same as the line containing the matching '{'
+  let thisline = getline(v:lnum)
+  if thisline =~ '^\s*}'
+    call cursor(v:lnum, 1)
+    silent normal %
+    let opening_lnum = line('.')
+    if opening_lnum != v:lnum
+      return indent(opening_lnum)
+    endif
+  endif
+
+  " Indent labels the same as the current opening block
+  if thisline =~ ':\s*$'
+    let blockbegin = FindOpenBracket(v:lnum)
+    if blockbegin > 0
+      return indent(blockbegin)
+    endif
+  endif
+
+  " Find a non-blank not-completely commented line above the current line.
+  let prev_lnum = prevnonblank(v:lnum - 1)
+  while prev_num > 0 && synIDattr(synID(prev_lnum, indent(prev_lnum)+1, 0), "name") =? "string\|comment"
+    let prev_lnum = prevnonblank(prev_lnum-1)
+  endwhile
+  " Hit the start of the file, use zero indent.
+  if prev_lnum == 0
+    return 0
+  endif
+
+  let ind = indent(prev_lnum)
+  let prevline = getline(prev_lnum)
+
+  " Add a 'shiftwidth' after lines that start a block or labels
+  if prevline =~ '{\s*$' || prevline =~ ':\s*$'
+    let ind = ind + &shiftwidth
+  endif
+
+  return ind
+endfunction