Highlight comments inside attributes.

Fixes #74.

Author: chris-morgan

syntax/rust.vim

@@ -3,7 +3,7 @@
 " Maintainer:   Patrick Walton <[email protected]>
 " Maintainer:   Ben Blum <[email protected]>
 " Maintainer:   Chris Morgan <[email protected]>
-" Last Change:  January 29, 2015
+" Last Change:  Feb 24, 2016
 
 if version < 600
   syntax clear
@@ -131,7 +131,7 @@ syn region    rustString      start=+b"+ skip=+\\\\\|\\"+ end=+"+ contains=rustE
 syn region    rustString      start=+"+ skip=+\\\\\|\\"+ end=+"+ contains=rustEscape,rustEscapeUnicode,rustEscapeError,rustStringContinuation,@Spell
 syn region    rustString      start='b\?r\z(#*\)"' end='"\z1' contains=@Spell
 
-syn region    rustAttribute   start="#!\?\[" end="\]" contains=rustString,rustDerive
+syn region    rustAttribute   start="#!\?\[" end="\]" contains=rustString,rustDerive,rustCommentLine,rustCommentBlock,rustCommentLineDocError,rustCommentBlockDocError
 syn region    rustDerive      start="derive(" end=")" contained contains=rustDeriveTrait
 " This list comes from src/libsyntax/ext/deriving/mod.rs
 " Some are deprecated (Encodable, Decodable) or to be removed after a new snapshot (Show).
@@ -168,12 +168,15 @@ syn match   rustCharacter   /b'\([^\\]\|\\\(.\|x\x\{2}\)\)'/ contains=rustEscape
 syn match   rustCharacter   /'\([^\\]\|\\\(.\|x\x\{2}\|u\x\{4}\|U\x\{8}\|u{\x\{1,6}}\)\)'/ contains=rustEscape,rustEscapeUnicode,rustEscapeError,rustCharacterInvalid
 
 syn match rustShebang /\%^#![^[].*/
-syn region rustCommentLine                                        start="//"                      end="$"   contains=rustTodo,@Spell
-syn region rustCommentLineDoc                                     start="//\%(//\@!\|!\)"         end="$"   contains=rustTodo,@Spell
-syn region rustCommentBlock    matchgroup=rustCommentBlock        start="/\*\%(!\|\*[*/]\@!\)\@!" end="\*/" contains=rustTodo,rustCommentBlockNest,@Spell
-syn region rustCommentBlockDoc matchgroup=rustCommentBlockDoc     start="/\*\%(!\|\*[*/]\@!\)"    end="\*/" contains=rustTodo,rustCommentBlockDocNest,@Spell
-syn region rustCommentBlockNest matchgroup=rustCommentBlock       start="/\*"                     end="\*/" contains=rustTodo,rustCommentBlockNest,@Spell contained transparent
-syn region rustCommentBlockDocNest matchgroup=rustCommentBlockDoc start="/\*"                     end="\*/" contains=rustTodo,rustCommentBlockDocNest,@Spell contained transparent
+syn region rustCommentLine                                                  start="//"                      end="$"   contains=rustTodo,@Spell
+syn region rustCommentLineDoc                                               start="//\%(//\@!\|!\)"         end="$"   contains=rustTodo,@Spell
+syn region rustCommentLineDocError                                          start="//\%(//\@!\|!\)"         end="$"   contains=rustTodo,@Spell contained
+syn region rustCommentBlock             matchgroup=rustCommentBlock         start="/\*\%(!\|\*[*/]\@!\)\@!" end="\*/" contains=rustTodo,rustCommentBlockNest,@Spell
+syn region rustCommentBlockDoc          matchgroup=rustCommentBlockDoc      start="/\*\%(!\|\*[*/]\@!\)"    end="\*/" contains=rustTodo,rustCommentBlockDocNest,@Spell
+syn region rustCommentBlockDocError     matchgroup=rustCommentBlockDocError start="/\*\%(!\|\*[*/]\@!\)"    end="\*/" contains=rustTodo,rustCommentBlockDocNestError,@Spell contained
+syn region rustCommentBlockNest         matchgroup=rustCommentBlock         start="/\*"                     end="\*/" contains=rustTodo,rustCommentBlockNest,@Spell contained transparent
+syn region rustCommentBlockDocNest      matchgroup=rustCommentBlockDoc      start="/\*"                     end="\*/" contains=rustTodo,rustCommentBlockDocNest,@Spell contained transparent
+syn region rustCommentBlockDocNestError matchgroup=rustCommentBlockDocError start="/\*"                     end="\*/" contains=rustTodo,rustCommentBlockDocNestError,@Spell contained transparent
 " FIXME: this is a really ugly and not fully correct implementation. Most
 " importantly, a case like ``/* */*`` should have the final ``*`` not being in
 " a comment, but in practice at present it leaves comments open two levels
@@ -236,8 +239,10 @@ hi def link rustFuncCall      Function
 hi def link rustShebang       Comment
 hi def link rustCommentLine   Comment
 hi def link rustCommentLineDoc SpecialComment
+hi def link rustCommentLineDocError Error
 hi def link rustCommentBlock  rustCommentLine
 hi def link rustCommentBlockDoc rustCommentLineDoc
+hi def link rustCommentBlockDocError Error
 hi def link rustAssert        PreCondit
 hi def link rustPanic         PreCondit
 hi def link rustMacro         Macro