diff --git a/runtime/syntax/go.vim b/runtime/syntax/go.vim
index e78f8cf..1439487 100644
--- a/runtime/syntax/go.vim
+++ b/runtime/syntax/go.vim
@@ -1,58 +1,109 @@
-" Vim syntax file
-" Language:	Go
-" Maintainer:	David Barnett (https://github.com/google/vim-ft-go)
-" Last Change:	2014 Aug 16
-
-" Options:
-"   There are some options for customizing the highlighting; the recommended
-"   settings are the default values, but you can write:
-"     let OPTION_NAME = 0
-"   in your ~/.vimrc file to disable particular options. You can also write:
-"     let OPTION_NAME = 1
-"   to enable particular options. At present, all options default to on.
+" Copyright 2009 The Go Authors. All rights reserved.
+" Use of this source code is governed by a BSD-style
+" license that can be found in the LICENSE file.
 "
-"   - g:go_highlight_array_whitespace_error
-"     Highlights white space after "[]".
-"   - g:go_highlight_chan_whitespace_error
-"     Highlights white space around the communications operator that don't
-"     follow the standard style.
-"   - g:go_highlight_extra_types
-"     Highlights commonly used library types (io.Reader, etc.).
-"   - g:go_highlight_space_tab_error
-"     Highlights instances of tabs following spaces.
-"   - g:go_highlight_trailing_whitespace_error
-"     Highlights trailing white space.
+" go.vim: Vim syntax file for Go.
+" Language:             Go
+" Maintainer:           Billie Cleek <bhcleek@gmail.com>
+" Latest Revision:      2021-06-26
+" License:              BSD-style. See LICENSE file in source repository.
+" Repository:           https://github.com/fatih/vim-go
 
 " Quit when a (custom) syntax file was already loaded
-if exists('b:current_syntax')
+if exists("b:current_syntax")
   finish
 endif
 
-if !exists('g:go_highlight_array_whitespace_error')
-  let g:go_highlight_array_whitespace_error = 1
-endif
-if !exists('g:go_highlight_chan_whitespace_error')
-  let g:go_highlight_chan_whitespace_error = 1
-endif
-if !exists('g:go_highlight_extra_types')
-  let g:go_highlight_extra_types = 1
-endif
-if !exists('g:go_highlight_space_tab_error')
-  let g:go_highlight_space_tab_error = 1
-endif
-if !exists('g:go_highlight_trailing_whitespace_error')
-  let g:go_highlight_trailing_whitespace_error = 1
-endif
+let s:keepcpo = &cpo
+set cpo&vim
+
+function! s:FoldEnable(...) abort
+  if a:0 > 0
+    return index(s:FoldEnable(), a:1) > -1
+  endif
+  return get(g:, 'go_fold_enable', ['block', 'import', 'varconst', 'package_comment'])
+endfunction
+
+function! s:HighlightArrayWhitespaceError() abort
+  return get(g:, 'go_highlight_array_whitespace_error', 0)
+endfunction
+
+function! s:HighlightChanWhitespaceError() abort
+  return get(g:, 'go_highlight_chan_whitespace_error', 0)
+endfunction
+
+function! s:HighlightExtraTypes() abort
+  return get(g:, 'go_highlight_extra_types', 0)
+endfunction
+
+function! s:HighlightSpaceTabError() abort
+  return get(g:, 'go_highlight_space_tab_error', 0)
+endfunction
+
+function! s:HighlightTrailingWhitespaceError() abort
+  return get(g:, 'go_highlight_trailing_whitespace_error', 0)
+endfunction
+
+function! s:HighlightOperators() abort
+  return get(g:, 'go_highlight_operators', 0)
+endfunction
+
+function! s:HighlightFunctions() abort
+  return get(g:, 'go_highlight_functions', 0)
+endfunction
+
+function! s:HighlightFunctionParameters() abort
+  return get(g:, 'go_highlight_function_parameters', 0)
+endfunction
+
+function! s:HighlightFunctionCalls() abort
+  return get(g:, 'go_highlight_function_calls', 0)
+endfunction
+
+function! s:HighlightFields() abort
+  return get(g:, 'go_highlight_fields', 0)
+endfunction
+
+function! s:HighlightTypes() abort
+  return get(g:, 'go_highlight_types', 0)
+endfunction
+
+function! s:HighlightBuildConstraints() abort
+  return get(g:, 'go_highlight_build_constraints', 0)
+endfunction
+
+function! s:HighlightStringSpellcheck() abort
+  return get(g:, 'go_highlight_string_spellcheck', 1)
+endfunction
+
+function! s:HighlightFormatStrings() abort
+  return get(g:, 'go_highlight_format_strings', 1)
+endfunction
+
+function! s:HighlightGenerateTags() abort
+  return get(g:, 'go_highlight_generate_tags', 0)
+endfunction
+
+function! s:HighlightVariableAssignments() abort
+  return get(g:, 'go_highlight_variable_assignments', 0)
+endfunction
+
+function! s:HighlightVariableDeclarations() abort
+  return get(g:, 'go_highlight_variable_declarations', 0)
+endfunction
 
 syn case match
 
-syn keyword     goDirective         package import
-syn keyword     goDeclaration       var const type
-syn keyword     goDeclType          struct interface
+syn keyword     goPackage           package
+syn keyword     goImport            import    contained
+syn keyword     goVar               var       contained
+syn keyword     goConst             const     contained
 
-hi def link     goDirective         Statement
+hi def link     goPackage           Statement
+hi def link     goImport            Statement
+hi def link     goVar               Keyword
+hi def link     goConst             Keyword
 hi def link     goDeclaration       Keyword
-hi def link     goDeclType          Keyword
 
 " Keywords within functions
 syn keyword     goStatement         defer go goto return break continue fallthrough
@@ -78,28 +129,38 @@
 hi def link     goFloats            Type
 hi def link     goComplexes         Type
 
-" Treat func specially: it's a declaration at the start of a line, but a type
-" elsewhere. Order matters here.
-syn match       goType              /\<func\>/
-syn match       goDeclaration       /^func\>/
-
 " Predefined functions and values
-syn keyword     goBuiltins          append cap close complex copy delete imag len
-syn keyword     goBuiltins          make new panic print println real recover
-syn keyword     goConstants         iota true false nil
+syn keyword     goBuiltins                 append cap close complex copy delete imag len
+syn keyword     goBuiltins                 make new panic print println real recover
+syn keyword     goBoolean                  true false
+syn keyword     goPredefinedIdentifiers    nil iota
 
-hi def link     goBuiltins          Keyword
-hi def link     goConstants         Keyword
+hi def link     goBuiltins                 Identifier
+hi def link     goBoolean                  Boolean
+hi def link     goPredefinedIdentifiers    goBoolean
 
 " Comments; their contents
 syn keyword     goTodo              contained TODO FIXME XXX BUG
 syn cluster     goCommentGroup      contains=goTodo
-syn region      goComment           start="/\*" end="\*/" contains=@goCommentGroup,@Spell
-syn region      goComment           start="//" end="$" contains=@goCommentGroup,@Spell
+
+syn region      goComment           start="//" end="$" contains=goGenerate,@goCommentGroup,@Spell
+if s:FoldEnable('comment')
+  syn region    goComment           start="/\*" end="\*/" contains=@goCommentGroup,@Spell fold
+  syn match     goComment           "\v(^\s*//.*\n)+" contains=goGenerate,@goCommentGroup,@Spell fold
+else
+  syn region    goComment           start="/\*" end="\*/" contains=@goCommentGroup,@Spell
+endif
 
 hi def link     goComment           Comment
 hi def link     goTodo              Todo
 
+if s:HighlightGenerateTags()
+  syn match       goGenerateVariables contained /\%(\$GOARCH\|\$GOOS\|\$GOFILE\|\$GOLINE\|\$GOPACKAGE\|\$DOLLAR\)\>/
+  syn region      goGenerate          start="^\s*//go:generate" end="$" contains=goGenerateVariables
+  hi def link     goGenerate          PreProc
+  hi def link     goGenerateVariables Special
+endif
+
 " Go escapes
 syn match       goEscapeOctal       display contained "\\[0-7]\{3}"
 syn match       goEscapeC           display contained +\\[abfnrtv\\'"]+
@@ -118,8 +179,30 @@
 
 " Strings and their contents
 syn cluster     goStringGroup       contains=goEscapeOctal,goEscapeC,goEscapeX,goEscapeU,goEscapeBigU,goEscapeError
-syn region      goString            start=+"+ skip=+\\\\\|\\"+ end=+"+ contains=@goStringGroup
-syn region      goRawString         start=+`+ end=+`+
+if s:HighlightStringSpellcheck()
+  syn region      goString            start=+"+ skip=+\\\\\|\\"+ end=+"+ contains=@goStringGroup,@Spell
+  syn region      goRawString         start=+`+ end=+`+ contains=@Spell
+else
+  syn region      goString            start=+"+ skip=+\\\\\|\\"+ end=+"+ contains=@goStringGroup
+  syn region      goRawString         start=+`+ end=+`+
+endif
+
+if s:HighlightFormatStrings()
+  " [n] notation is valid for specifying explicit argument indexes
+  " 1. Match a literal % not preceded by a %.
+  " 2. Match any number of -, #, 0, space, or +
+  " 3. Match * or [n]* or any number or nothing before a .
+  " 4. Match * or [n]* or any number or nothing after a .
+  " 5. Match [n] or nothing before a verb
+  " 6. Match a formatting verb
+  syn match       goFormatSpecifier   /\
+        \%([^%]\%(%%\)*\)\
+        \@<=%[-#0 +]*\
+        \%(\%(\%(\[\d\+\]\)\=\*\)\|\d\+\)\=\
+        \%(\.\%(\%(\%(\[\d\+\]\)\=\*\)\|\d\+\)\=\)\=\
+        \%(\[\d\+\]\)\=[vTtbcdoqxXUeEfFgGspw]/ contained containedin=goString,goRawString
+  hi def link     goFormatSpecifier   goSpecialString
+endif
 
 hi def link     goString            String
 hi def link     goRawString         String
@@ -131,71 +214,263 @@
 hi def link     goCharacter         Character
 
 " Regions
-syn region      goBlock             start="{" end="}" transparent fold
 syn region      goParen             start='(' end=')' transparent
+if s:FoldEnable('block')
+  syn region    goBlock             start="{" end="}" transparent fold
+else
+  syn region    goBlock             start="{" end="}" transparent
+endif
+
+" import
+if s:FoldEnable('import')
+  syn region    goImport            start='import (' end=')' transparent fold contains=goImport,goString,goComment
+else
+  syn region    goImport            start='import (' end=')' transparent contains=goImport,goString,goComment
+endif
+
+" var, const
+if s:FoldEnable('varconst')
+  syn region    goVar               start='var ('   end='^\s*)$' transparent fold
+                        \ contains=ALLBUT,goParen,goBlock,goFunction,goTypeName,goReceiverType,goReceiverVar,goParamName,goParamType,goSimpleParams,goPointerOperator
+  syn region    goConst             start='const (' end='^\s*)$' transparent fold
+                        \ contains=ALLBUT,goParen,goBlock,goFunction,goTypeName,goReceiverType,goReceiverVar,goParamName,goParamType,goSimpleParams,goPointerOperator
+else
+  syn region    goVar               start='var ('   end='^\s*)$' transparent
+                        \ contains=ALLBUT,goParen,goBlock,goFunction,goTypeName,goReceiverType,goReceiverVar,goParamName,goParamType,goSimpleParams,goPointerOperator
+  syn region    goConst             start='const (' end='^\s*)$' transparent
+                        \ contains=ALLBUT,goParen,goBlock,goFunction,goTypeName,goReceiverType,goReceiverVar,goParamName,goParamType,goSimpleParams,goPointerOperator
+endif
+
+" Single-line var, const, and import.
+syn match       goSingleDecl        /\%(import\|var\|const\) [^(]\@=/ contains=goImport,goVar,goConst
 
 " Integers
-syn match       goDecimalInt        "\<\d\+\([Ee]\d\+\)\?\>"
-syn match       goHexadecimalInt    "\<0x\x\+\>"
-syn match       goOctalInt          "\<0\o\+\>"
-syn match       goOctalError        "\<0\o*[89]\d*\>"
+syn match       goDecimalInt        "\<-\=\(0\|[1-9]_\?\(\d\|\d\+_\?\d\+\)*\)\%([Ee][-+]\=\d\+\)\=\>"
+syn match       goDecimalError      "\<-\=\(_\(\d\+_*\)\+\|\([1-9]\d*_*\)\+__\(\d\+_*\)\+\|\([1-9]\d*_*\)\+_\+\)\%([Ee][-+]\=\d\+\)\=\>"
+syn match       goHexadecimalInt    "\<-\=0[xX]_\?\(\x\+_\?\)\+\>"
+syn match       goHexadecimalError  "\<-\=0[xX]_\?\(\x\+_\?\)*\(\([^ \t0-9A-Fa-f_)]\|__\)\S*\|_\)\>"
+syn match       goOctalInt          "\<-\=0[oO]\?_\?\(\o\+_\?\)\+\>"
+syn match       goOctalError        "\<-\=0[0-7oO_]*\(\([^ \t0-7oOxX_/)\]\}\:]\|[oO]\{2,\}\|__\)\S*\|_\|[oOxX]\)\>"
+syn match       goBinaryInt         "\<-\=0[bB]_\?\([01]\+_\?\)\+\>"
+syn match       goBinaryError       "\<-\=0[bB]_\?[01_]*\([^ \t01_)]\S*\|__\S*\|_\)\>"
 
 hi def link     goDecimalInt        Integer
+hi def link     goDecimalError      Error
 hi def link     goHexadecimalInt    Integer
+hi def link     goHexadecimalError  Error
 hi def link     goOctalInt          Integer
+hi def link     goOctalError        Error
+hi def link     goBinaryInt         Integer
+hi def link     goBinaryError       Error
 hi def link     Integer             Number
 
 " Floating point
-syn match       goFloat             "\<\d\+\.\d*\([Ee][-+]\d\+\)\?\>"
-syn match       goFloat             "\<\.\d\+\([Ee][-+]\d\+\)\?\>"
-syn match       goFloat             "\<\d\+[Ee][-+]\d\+\>"
+syn match       goFloat             "\<-\=\d\+\.\d*\%([Ee][-+]\=\d\+\)\=\>"
+syn match       goFloat             "\<-\=\.\d\+\%([Ee][-+]\=\d\+\)\=\>"
 
 hi def link     goFloat             Float
 
 " Imaginary literals
-syn match       goImaginary         "\<\d\+i\>"
-syn match       goImaginary         "\<\d\+\.\d*\([Ee][-+]\d\+\)\?i\>"
-syn match       goImaginary         "\<\.\d\+\([Ee][-+]\d\+\)\?i\>"
-syn match       goImaginary         "\<\d\+[Ee][-+]\d\+i\>"
+syn match       goImaginary         "\<-\=\d\+i\>"
+syn match       goImaginary         "\<-\=\d\+[Ee][-+]\=\d\+i\>"
+syn match       goImaginaryFloat    "\<-\=\d\+\.\d*\%([Ee][-+]\=\d\+\)\=i\>"
+syn match       goImaginaryFloat    "\<-\=\.\d\+\%([Ee][-+]\=\d\+\)\=i\>"
 
 hi def link     goImaginary         Number
+hi def link     goImaginaryFloat    Float
 
 " Spaces after "[]"
-if go_highlight_array_whitespace_error != 0
-  syn match goSpaceError display "\(\[\]\)\@<=\s\+"
+if s:HighlightArrayWhitespaceError()
+  syn match goSpaceError display "\%(\[\]\)\@<=\s\+"
 endif
 
 " Spacing errors around the 'chan' keyword
-if go_highlight_chan_whitespace_error != 0
+if s:HighlightChanWhitespaceError()
   " receive-only annotation on chan type
-  syn match goSpaceError display "\(<-\)\@<=\s\+\(chan\>\)\@="
+  "
+  " \(\<chan\>\)\@<!<-  (only pick arrow when it doesn't come after a chan)
+  " this prevents picking up 'chan<- chan<-' but not '<- chan'
+  syn match goSpaceError display "\%(\%(\<chan\>\)\@<!<-\)\@<=\s\+\%(\<chan\>\)\@="
+
   " send-only annotation on chan type
-  syn match goSpaceError display "\(\<chan\)\@<=\s\+\(<-\)\@="
+  "
+  " \(<-\)\@<!\<chan\>  (only pick chan when it doesn't come after an arrow)
+  " this prevents picking up '<-chan <-chan' but not 'chan <-'
+  syn match goSpaceError display "\%(\%(<-\)\@<!\<chan\>\)\@<=\s\+\%(<-\)\@="
+
   " value-ignoring receives in a few contexts
-  syn match goSpaceError display "\(\(^\|[={(,;]\)\s*<-\)\@<=\s\+"
+  syn match goSpaceError display "\%(\%(^\|[={(,;]\)\s*<-\)\@<=\s\+"
 endif
 
 " Extra types commonly seen
-if go_highlight_extra_types != 0
-  syn match goExtraType /\<bytes\.\(Buffer\)\>/
-  syn match goExtraType /\<io\.\(Reader\|Writer\|ReadWriter\|ReadWriteCloser\)\>/
-  syn match goExtraType /\<reflect\.\(Kind\|Type\|Value\)\>/
+if s:HighlightExtraTypes()
+  syn match goExtraType /\<bytes\.\%(Buffer\)\>/
+  syn match goExtraType /\<context\.\%(Context\)\>/
+  syn match goExtraType /\<io\.\%(Reader\|ReadSeeker\|ReadWriter\|ReadCloser\|ReadWriteCloser\|Writer\|WriteCloser\|Seeker\)\>/
+  syn match goExtraType /\<reflect\.\%(Kind\|Type\|Value\)\>/
   syn match goExtraType /\<unsafe\.Pointer\>/
 endif
 
 " Space-tab error
-if go_highlight_space_tab_error != 0
+if s:HighlightSpaceTabError()
   syn match goSpaceError display " \+\t"me=e-1
 endif
 
 " Trailing white space error
-if go_highlight_trailing_whitespace_error != 0
+if s:HighlightTrailingWhitespaceError()
   syn match goSpaceError display excludenl "\s\+$"
 endif
 
 hi def link     goExtraType         Type
 hi def link     goSpaceError        Error
 
+
+
+" included from: https://github.com/athom/more-colorful.vim/blob/master/after/syntax/go.vim
+"
+" Comments; their contents
+syn keyword     goTodo              contained NOTE
+hi def link     goTodo              Todo
+
+syn match goVarArgs /\.\.\./
+
+" Operators;
+if s:HighlightOperators()
+  " match single-char operators:          - + % < > ! & | ^ * =
+  " and corresponding two-char operators: -= += %= <= >= != &= |= ^= *= ==
+  syn match goOperator /[-+%<>!&|^*=]=\?/
+  " match / and /=
+  syn match goOperator /\/\%(=\|\ze[^/*]\)/
+  " match two-char operators:               << >> &^
+  " and corresponding three-char operators: <<= >>= &^=
+  syn match goOperator /\%(<<\|>>\|&^\)=\?/
+  " match remaining two-char operators: := && || <- ++ --
+  syn match goOperator /:=\|||\|<-\|++\|--/
+  " match ...
+
+  hi def link     goPointerOperator   goOperator
+  hi def link     goVarArgs           goOperator
+endif
+hi def link     goOperator          Operator
+
+" Functions;
+if s:HighlightFunctions() || s:HighlightFunctionParameters()
+  syn match goDeclaration       /\<func\>/ nextgroup=goReceiver,goFunction,goSimpleParams skipwhite skipnl
+  syn match goReceiverVar       /\w\+\ze\s\+\%(\w\|\*\)/ nextgroup=goPointerOperator,goReceiverType skipwhite skipnl contained
+  syn match goPointerOperator   /\*/ nextgroup=goReceiverType contained skipwhite skipnl
+  syn match goFunction          /\w\+/ nextgroup=goSimpleParams contained skipwhite skipnl
+  syn match goReceiverType      /\w\+/ contained
+  if s:HighlightFunctionParameters()
+    syn match goSimpleParams      /(\%(\w\|\_s\|[*\.\[\],\{\}<>-]\)*)/ contained contains=goParamName,goType nextgroup=goFunctionReturn skipwhite skipnl
+    syn match goFunctionReturn   /(\%(\w\|\_s\|[*\.\[\],\{\}<>-]\)*)/ contained contains=goParamName,goType skipwhite skipnl
+    syn match goParamName        /\w\+\%(\s*,\s*\w\+\)*\ze\s\+\%(\w\|\.\|\*\|\[\)/ contained nextgroup=goParamType skipwhite skipnl
+    syn match goParamType        /\%([^,)]\|\_s\)\+,\?/ contained nextgroup=goParamName skipwhite skipnl
+                          \ contains=goVarArgs,goType,goSignedInts,goUnsignedInts,goFloats,goComplexes,goDeclType,goBlock
+    hi def link   goReceiverVar    goParamName
+    hi def link   goParamName      Identifier
+  endif
+  syn match goReceiver          /(\s*\w\+\%(\s\+\*\?\s*\w\+\)\?\s*)\ze\s*\w/ contained nextgroup=goFunction contains=goReceiverVar skipwhite skipnl
+else
+  syn keyword goDeclaration func
+endif
+hi def link     goFunction          Function
+
+" Function calls;
+if s:HighlightFunctionCalls()
+  syn match goFunctionCall      /\w\+\ze(/ contains=goBuiltins,goDeclaration
+endif
+hi def link     goFunctionCall      Type
+
+" Fields;
+if s:HighlightFields()
+  " 1. Match a sequence of word characters coming after a '.'
+  " 2. Require the following but dont match it: ( \@= see :h E59)
+  "    - The symbols: / - + * %   OR
+  "    - The symbols: [] {} <> )  OR
+  "    - The symbols: \n \r space OR
+  "    - The symbols: , : .
+  " 3. Have the start of highlight (hs) be the start of matched
+  "    pattern (s) offsetted one to the right (+1) (see :h E401)
+  syn match       goField   /\.\w\+\
+        \%(\%([\/\-\+*%]\)\|\
+        \%([\[\]{}<\>\)]\)\|\
+        \%([\!=\^|&]\)\|\
+        \%([\n\r\ ]\)\|\
+        \%([,\:.]\)\)\@=/hs=s+1
+endif
+hi def link    goField              Identifier
+
+" Structs & Interfaces;
+if s:HighlightTypes()
+  syn match goTypeConstructor      /\<\w\+{\@=/
+  syn match goTypeDecl             /\<type\>/ nextgroup=goTypeName skipwhite skipnl
+  syn match goTypeName             /\w\+/ contained nextgroup=goDeclType skipwhite skipnl
+  syn match goDeclType             /\<\%(interface\|struct\)\>/ skipwhite skipnl
+  hi def link     goReceiverType      Type
+else
+  syn keyword goDeclType           struct interface
+  syn keyword goDeclaration        type
+endif
+hi def link     goTypeConstructor   Type
+hi def link     goTypeName          Type
+hi def link     goTypeDecl          Keyword
+hi def link     goDeclType          Keyword
+
+" Variable Assignments
+if s:HighlightVariableAssignments()
+  syn match goVarAssign /\v[_.[:alnum:]]+(,\s*[_.[:alnum:]]+)*\ze(\s*([-^+|^\/%&]|\*|\<\<|\>\>|\&\^)?\=[^=])/
+  hi def link   goVarAssign         Special
+endif
+
+" Variable Declarations
+if s:HighlightVariableDeclarations()
+  syn match goVarDefs /\v\w+(,\s*\w+)*\ze(\s*:\=)/
+  hi def link   goVarDefs           Special
+endif
+
+" Build Constraints
+if s:HighlightBuildConstraints()
+  syn match   goBuildKeyword      display contained "+build"
+  " Highlight the known values of GOOS, GOARCH, and other +build options.
+  syn keyword goBuildDirectives   contained
+        \ android darwin dragonfly freebsd linux nacl netbsd openbsd plan9
+        \ solaris windows 386 amd64 amd64p32 arm armbe arm64 arm64be ppc64
+        \ ppc64le mips mipsle mips64 mips64le mips64p32 mips64p32le ppc
+        \ s390 s390x sparc sparc64 cgo ignore race
+
+  " Other words in the build directive are build tags not listed above, so
+  " avoid highlighting them as comments by using a matchgroup just for the
+  " start of the comment.
+  " The rs=s+2 option lets the \s*+build portion be part of the inner region
+  " instead of the matchgroup so it will be highlighted as a goBuildKeyword.
+  syn region  goBuildComment      matchgroup=goBuildCommentStart
+        \ start="//\s*+build\s"rs=s+2 end="$"
+        \ contains=goBuildKeyword,goBuildDirectives
+  hi def link goBuildCommentStart Comment
+  hi def link goBuildDirectives   Type
+  hi def link goBuildKeyword      PreProc
+endif
+
+if s:HighlightBuildConstraints() || s:FoldEnable('package_comment')
+  " One or more line comments that are followed immediately by a "package"
+  " declaration are treated like package documentation, so these must be
+  " matched as comments to avoid looking like working build constraints.
+  " The he, me, and re options let the "package" itself be highlighted by
+  " the usual rules.
+  exe 'syn region  goPackageComment    start=/\v(\/\/.*\n)+\s*package/'
+        \ . ' end=/\v\n\s*package/he=e-7,me=e-7,re=e-7'
+        \ . ' contains=@goCommentGroup,@Spell'
+        \ . (s:FoldEnable('package_comment') ? ' fold' : '')
+  exe 'syn region  goPackageComment    start=/\v^\s*\/\*.*\n(.*\n)*\s*\*\/\npackage/'
+        \ . ' end=/\v\*\/\n\s*package/he=e-7,me=e-7,re=e-7'
+        \ . ' contains=@goCommentGroup,@Spell'
+        \ . (s:FoldEnable('package_comment') ? ' fold' : '')
+  hi def link goPackageComment    Comment
+endif
+
+" :GoCoverage commands
+hi def link goCoverageNormalText Comment
+
 " Search backwards for a global declaration to start processing the syntax.
 "syn sync match goSync grouphere NONE /^\(const\|var\|type\|func\)\>/
 
@@ -203,6 +478,9 @@
 " following as a more expensive/less precise workaround.
 syn sync minlines=500
 
-let b:current_syntax = 'go'
+let b:current_syntax = "go"
+
+let &cpo = s:keepcpo
+unlet s:keepcpo
 
 " vim: sw=2 sts=2 et