merge master -- apparently someone else added dhall?

31 files changed, 891 insertions, 537 deletions

diff --git a/autoload/ale.vim b/autoload/ale.vim
index 6251b47b..5ec22f57 100644
--- a/autoload/ale.vim
+++ b/autoload/ale.vim
@@ -263,6 +263,28 @@ function! ale#GetLocItemMessage(item, format_string) abort
     let l:msg = substitute(l:msg, '\V%linter%', '\=l:linter_name', 'g')
     " Replace %s with the text.
     let l:msg = substitute(l:msg, '\V%s', '\=a:item.text', 'g')
+    " Windows may insert carriage return line endings (^M), strip these characters.
+    let l:msg = substitute(l:msg, '\r', '', 'g')
 
     return l:msg
 endfunction
+
+" Given a buffer and a linter or fixer name, return an Array of two-item
+" Arrays describing how to map filenames to and from the local to foreign file
+" systems.
+function! ale#GetFilenameMappings(buffer, name) abort
+    let l:linter_mappings = ale#Var(a:buffer, 'filename_mappings')
+
+    if type(l:linter_mappings) is v:t_list
+        return l:linter_mappings
+    endif
+
+    let l:name = a:name
+
+    if !has_key(l:linter_mappings, l:name)
+        " Use * as a default setting for all tools.
+        let l:name = '*'
+    endif
+
+    return get(l:linter_mappings, l:name, [])
+endfunction
diff --git a/autoload/ale/assert.vim b/autoload/ale/assert.vim
index 291edcee..934fcaa8 100644
--- a/autoload/ale/assert.vim
+++ b/autoload/ale/assert.vim
@@ -130,7 +130,7 @@ endfunction
 function! ale#assert#LSPLanguage(expected_language) abort
     let l:buffer = bufnr('')
     let l:linter = s:GetLinter()
-    let l:language = ale#util#GetFunction(l:linter.language_callback)(l:buffer)
+    let l:language = ale#linter#GetLanguage(l:buffer, l:linter)
 
     AssertEqual a:expected_language, l:language
 endfunction
diff --git a/autoload/ale/c.vim b/autoload/ale/c.vim
index 39892d42..cff53125 100644
--- a/autoload/ale/c.vim
+++ b/autoload/ale/c.vim
@@ -2,12 +2,27 @@
 " Description: Functions for integrating with C-family linters.
 
 call ale#Set('c_parse_makefile', 0)
+call ale#Set('c_always_make', has('unix') && !has('macunix'))
 call ale#Set('c_parse_compile_commands', 1)
+
 let s:sep = has('win32') ? '\' : '/'
 
 " Set just so tests can override it.
 let g:__ale_c_project_filenames = ['.git/HEAD', 'configure', 'Makefile', 'CMakeLists.txt']
 
+let g:ale_c_build_dir_names = get(g:, 'ale_c_build_dir_names', [
+\   'build',
+\   'bin',
+\])
+
+function! s:CanParseMakefile(buffer) abort
+    " Something somewhere seems to delete this setting in tests, so ensure we
+    " always have a default value.
+    call ale#Set('c_parse_makefile', 0)
+
+    return ale#Var(a:buffer, 'c_parse_makefile')
+endfunction
+
 function! ale#c#GetBuildDirectory(buffer) abort
     let l:build_dir = ale#Var(a:buffer, 'c_build_dir')
 
@@ -61,14 +76,73 @@ function! ale#c#ShellSplit(line) abort
     return l:args
 endfunction
 
-function! ale#c#ParseCFlags(path_prefix, cflag_line) abort
-    let l:cflags_list = []
+" Takes the path prefix and a list of cflags and expands @file arguments to
+" the contents of the file.
+"
+" @file arguments are command line arguments recognised by gcc and clang. For
+" instance, if @./path/to/file was given to gcc, it would load .path/to/file
+" and use the contents of that file as arguments.
+function! ale#c#ExpandAtArgs(path_prefix, raw_split_lines) abort
+    let l:out_lines = []
+
+    for l:option in a:raw_split_lines
+        if stridx(l:option, '@') == 0
+            " This is an argument specifying a location of a file containing other arguments
+            let l:path = join(split(l:option, '\zs')[1:], '')
+
+            " Make path absolute
+            if !ale#path#IsAbsolute(l:path)
+                let l:rel_path = substitute(l:path, '"', '', 'g')
+                let l:rel_path = substitute(l:rel_path, '''', '', 'g')
+                let l:path = ale#path#GetAbsPath(a:path_prefix, l:rel_path)
+            endif
+
+            " Read the file and add all the arguments
+            try
+                let l:additional_args = readfile(l:path)
+            catch
+                continue " All we can really do is skip this argument
+            endtry
+
+            let l:file_lines = []
+
+            for l:line in l:additional_args
+                let l:file_lines += ale#c#ShellSplit(l:line)
+            endfor
+
+            " @file arguments can include other @file arguments, so we must
+            " recurse.
+            let l:out_lines += ale#c#ExpandAtArgs(a:path_prefix, l:file_lines)
+        else
+            " This is not an @file argument, so don't touch it.
+            let l:out_lines += [l:option]
+        endif
+    endfor
+
+    return l:out_lines
+endfunction
+
+" Quote C/C++ a compiler argument, if needed.
+"
+" Quoting arguments might cause issues with some systems/compilers, so we only
+" quote them if we need to.
+function! ale#c#QuoteArg(arg) abort
+    if a:arg !~# '\v[#$&*()\\|[\]{};''"<>/?! ^%]'
+        return a:arg
+    endif
+
+    return ale#Escape(a:arg)
+endfunction
 
-    let l:split_lines = ale#c#ShellSplit(a:cflag_line)
+function! ale#c#ParseCFlags(path_prefix, should_quote, raw_arguments) abort
+    " Expand @file arguments now before parsing
+    let l:arguments = ale#c#ExpandAtArgs(a:path_prefix, a:raw_arguments)
+    " A list of [already_quoted, argument]
+    let l:items = []
     let l:option_index = 0
 
-    while l:option_index < len(l:split_lines)
-        let l:option = l:split_lines[l:option_index]
+    while l:option_index < len(l:arguments)
+        let l:option = l:arguments[l:option_index]
         let l:option_index = l:option_index + 1
 
         " Include options, that may need relative path fix
@@ -76,56 +150,67 @@ function! ale#c#ParseCFlags(path_prefix, cflag_line) abort
         \ || stridx(l:option, '-iquote') == 0
         \ || stridx(l:option, '-isystem') == 0
         \ || stridx(l:option, '-idirafter') == 0
+        \ || stridx(l:option, '-iframework') == 0
+        \ || stridx(l:option, '-include') == 0
             if stridx(l:option, '-I') == 0 && l:option isnot# '-I'
                 let l:arg = join(split(l:option, '\zs')[2:], '')
                 let l:option = '-I'
             else
-                let l:arg = l:split_lines[l:option_index]
+                let l:arg = l:arguments[l:option_index]
                 let l:option_index = l:option_index + 1
             endif
 
             " Fix relative paths if needed
-            if stridx(l:arg, s:sep) != 0 && stridx(l:arg, '/') != 0
+            if !ale#path#IsAbsolute(l:arg)
                 let l:rel_path = substitute(l:arg, '"', '', 'g')
                 let l:rel_path = substitute(l:rel_path, '''', '', 'g')
-                let l:arg = ale#Escape(a:path_prefix . s:sep . l:rel_path)
+                let l:arg = ale#path#GetAbsPath(a:path_prefix, l:rel_path)
             endif
 
-            call add(l:cflags_list, l:option)
-            call add(l:cflags_list, l:arg)
+            call add(l:items, [1, l:option])
+            call add(l:items, [1, ale#Escape(l:arg)])
         " Options with arg that can be grouped with the option or separate
         elseif stridx(l:option, '-D') == 0 || stridx(l:option, '-B') == 0
-            call add(l:cflags_list, l:option)
-
             if l:option is# '-D' || l:option is# '-B'
-                call add(l:cflags_list, l:split_lines[l:option_index])
+                call add(l:items, [1, l:option])
+                call add(l:items, [0, l:arguments[l:option_index]])
                 let l:option_index = l:option_index + 1
+            else
+                call add(l:items, [0, l:option])
             endif
         " Options that have an argument (always separate)
         elseif l:option is# '-iprefix' || stridx(l:option, '-iwithprefix') == 0
         \ || l:option is# '-isysroot' || l:option is# '-imultilib'
-            call add(l:cflags_list, l:option)
-            call add(l:cflags_list, l:split_lines[l:option_index])
+            call add(l:items, [0, l:option])
+            call add(l:items, [0, l:arguments[l:option_index]])
             let l:option_index = l:option_index + 1
         " Options without argument
         elseif (stridx(l:option, '-W') == 0 && stridx(l:option, '-Wa,') != 0 && stridx(l:option, '-Wl,') != 0 && stridx(l:option, '-Wp,') != 0)
         \ || l:option is# '-w' || stridx(l:option, '-pedantic') == 0
         \ || l:option is# '-ansi' || stridx(l:option, '-std=') == 0
-        \ || (stridx(l:option, '-f') == 0 && stridx(l:option, '-fdump') != 0 && stridx(l:option, '-fdiagnostics') != 0 && stridx(l:option, '-fno-show-column') != 0)
+        \ || stridx(l:option, '-f') == 0 && l:option !~# '\v^-f(dump|diagnostics|no-show-column|stack-usage)'
         \ || stridx(l:option, '-O') == 0
         \ || l:option is# '-C' || l:option is# '-CC' || l:option is# '-trigraphs'
         \ || stridx(l:option, '-nostdinc') == 0 || stridx(l:option, '-iplugindir=') == 0
         \ || stridx(l:option, '--sysroot=') == 0 || l:option is# '--no-sysroot-suffix'
         \ || stridx(l:option, '-m') == 0
-            call add(l:cflags_list, l:option)
+            call add(l:items, [0, l:option])
         endif
     endwhile
 
-    return join(l:cflags_list, ' ')
+    if a:should_quote
+        " Quote C arguments that haven't already been quoted above.
+        " If and only if we've been asked to quote them.
+        call map(l:items, 'v:val[0] ? v:val[1] : ale#c#QuoteArg(v:val[1])')
+    else
+        call map(l:items, 'v:val[1]')
+    endif
+
+    return join(l:items, ' ')
 endfunction
 
 function! ale#c#ParseCFlagsFromMakeOutput(buffer, make_output) abort
-    if !g:ale_c_parse_makefile
+    if !s:CanParseMakefile(a:buffer)
         return v:null
     endif
 
@@ -143,7 +228,7 @@ function! ale#c#ParseCFlagsFromMakeOutput(buffer, make_output) abort
     let l:makefile_path = ale#path#FindNearestFile(a:buffer, 'Makefile')
     let l:makefile_dir = fnamemodify(l:makefile_path, ':p:h')
 
-    return ale#c#ParseCFlags(l:makefile_dir, l:cflag_line)
+    return ale#c#ParseCFlags(l:makefile_dir, 0, ale#c#ShellSplit(l:cflag_line))
 endfunction
 
 " Given a buffer number, find the project directory containing
@@ -211,6 +296,10 @@ if !exists('s:compile_commands_cache')
     let s:compile_commands_cache = {}
 endif
 
+function! ale#c#ResetCompileCommandsCache() abort
+    let s:compile_commands_cache = {}
+endfunction
+
 function! s:GetLookupFromCompileCommandsFile(compile_commands_file) abort
     let l:empty = [{}, {}]
 
@@ -241,9 +330,20 @@ function! s:GetLookupFromCompileCommandsFile(compile_commands_file) abort
     let l:dir_lookup = {}
 
     for l:entry in (type(l:raw_data) is v:t_list ? l:raw_data : [])
+        let l:filename = ale#path#GetAbsPath(l:entry.directory, l:entry.file)
+
+        " Store a key for lookups by the absolute path to the filename.
+        let l:file_lookup[l:filename] = get(l:file_lookup, l:filename, []) + [l:entry]
+
+        " Store a key for fuzzy lookups by the absolute path to the directory.
+        let l:dirname = fnamemodify(l:filename, ':h')
+        let l:dir_lookup[l:dirname] = get(l:dir_lookup, l:dirname, []) + [l:entry]
+
+        " Store a key for fuzzy lookups by just the basename of the file.
         let l:basename = tolower(fnamemodify(l:entry.file, ':t'))
         let l:file_lookup[l:basename] = get(l:file_lookup, l:basename, []) + [l:entry]
 
+        " Store a key for fuzzy lookups by just the basename of the directory.
         let l:dirbasename = tolower(fnamemodify(l:entry.directory, ':p:h:t'))
         let l:dir_lookup[l:dirbasename] = get(l:dir_lookup, l:dirbasename, []) + [l:entry]
     endfor
@@ -258,28 +358,80 @@ function! s:GetLookupFromCompileCommandsFile(compile_commands_file) abort
     return l:empty
 endfunction
 
-function! ale#c#GetCompileCommand(json_item) abort
-    if has_key(a:json_item, 'command')
-        return a:json_item.command
-    elseif has_key(a:json_item, 'arguments')
-        return join(a:json_item.arguments, ' ')
+" Get [should_quote, arguments] from either 'command' or 'arguments'
+" 'arguments' should be quoted later, the split 'command' strings should not.
+function! s:GetArguments(json_item) abort
+    if has_key(a:json_item, 'arguments')
+        return [1, a:json_item.arguments]
+    elseif has_key(a:json_item, 'command')
+        return [0, ale#c#ShellSplit(a:json_item.command)]
     endif
 
-    return ''
+    return [0, []]
 endfunction
 
 function! ale#c#ParseCompileCommandsFlags(buffer, file_lookup, dir_lookup) abort
+    let l:buffer_filename = ale#path#Simplify(expand('#' . a:buffer . ':p'))
+    let l:basename = tolower(fnamemodify(l:buffer_filename, ':t'))
+    " Look for any file in the same directory if we can't find an exact match.
+    let l:dir = fnamemodify(l:buffer_filename, ':h')
+
     " Search for an exact file match first.
-    let l:basename = tolower(expand('#' . a:buffer . ':t'))
-    let l:file_list = get(a:file_lookup, l:basename, [])
+    let l:file_list = get(a:file_lookup, l:buffer_filename, [])
+
+    " We may have to look for /foo/bar instead of C:\foo\bar
+    if empty(l:file_list) && has('win32')
+        let l:file_list = get(
+        \   a:file_lookup,
+        \   ale#path#RemoveDriveLetter(l:buffer_filename),
+        \   []
+        \)
+    endif
+
+    " Try the absolute path to the directory second.
+    let l:dir_list = get(a:dir_lookup, l:dir, [])
+
+    if empty(l:dir_list) && has('win32')
+        let l:dir_list = get(
+        \   a:dir_lookup,
+        \   ale#path#RemoveDriveLetter(l:dir),
+        \   []
+        \)
+    endif
+
+    if empty(l:file_list) && empty(l:dir_list)
+        " If we can't find matches with the path to the file, try a
+        " case-insensitive match for any similarly-named file.
+        let l:file_list = get(a:file_lookup, l:basename, [])
+
+        " If we can't find matches with the path to the directory, try a
+        " case-insensitive match for anything in similarly-named directory.
+        let l:dir_list = get(a:dir_lookup, tolower(fnamemodify(l:dir, ':t')), [])
+    endif
+
     " A source file matching the header filename.
     let l:source_file = ''
 
     if empty(l:file_list) && l:basename =~? '\.h$\|\.hpp$'
         for l:suffix in ['.c', '.cpp']
-            let l:key = fnamemodify(l:basename, ':r') . l:suffix
+            " Try to find a source file by an absolute path first.
+            let l:key = fnamemodify(l:buffer_filename, ':r') . l:suffix
             let l:file_list = get(a:file_lookup, l:key, [])
 
+            if empty(l:file_list) && has('win32')
+                let l:file_list = get(
+                \   a:file_lookup,
+                \   ale#path#RemoveDriveLetter(l:key),
+                \   []
+                \)
+            endif
+
+            if empty(l:file_list)
+                " Look fuzzy matches on the basename second.
+                let l:key = fnamemodify(l:basename, ':r') . l:suffix
+                let l:file_list = get(a:file_lookup, l:key, [])
+            endif
+
             if !empty(l:file_list)
                 let l:source_file = l:key
                 break
@@ -288,28 +440,31 @@ function! ale#c#ParseCompileCommandsFlags(buffer, file_lookup, dir_lookup) abort
     endif
 
     for l:item in l:file_list
+        let l:filename = ale#path#GetAbsPath(l:item.directory, l:item.file)
+
         " Load the flags for this file, or for a source file matching the
         " header file.
         if (
-        \   bufnr(l:item.file) is a:buffer
+        \   bufnr(l:filename) is a:buffer
         \   || (
         \       !empty(l:source_file)
-        \       && l:item.file[-len(l:source_file):] is? l:source_file
+        \       && l:filename[-len(l:source_file):] is? l:source_file
         \   )
         \)
-            return ale#c#ParseCFlags(l:item.directory, ale#c#GetCompileCommand(l:item))
+            let [l:should_quote, l:args] = s:GetArguments(l:item)
+
+            return ale#c#ParseCFlags(l:item.directory, l:should_quote, l:args)
         endif
     endfor
 
-    " Look for any file in the same directory if we can't find an exact match.
-    let l:dir = ale#path#Simplify(expand('#' . a:buffer . ':p:h'))
+    for l:item in l:dir_list
+        let l:filename = ale#path#GetAbsPath(l:item.directory, l:item.file)
 
-    let l:dirbasename = tolower(expand('#' . a:buffer . ':p:h:t'))
-    let l:dir_list = get(a:dir_lookup, l:dirbasename, [])
+        if ale#path#RemoveDriveLetter(fnamemodify(l:filename, ':h'))
+        \  is? ale#path#RemoveDriveLetter(l:dir)
+            let [l:should_quote, l:args] = s:GetArguments(l:item)
 
-    for l:item in l:dir_list
-        if ale#path#Simplify(fnamemodify(l:item.file, ':h')) is? l:dir
-            return ale#c#ParseCFlags(l:item.directory, ale#c#GetCompileCommand(l:item))
+            return ale#c#ParseCFlags(l:item.directory, l:should_quote, l:args)
         endif
     endfor
 
@@ -335,9 +490,7 @@ function! ale#c#GetCFlags(buffer, output) abort
         endif
     endif
 
-    if ale#Var(a:buffer, 'c_parse_makefile')
-    \&& !empty(a:output)
-    \&& !empty(l:cflags)
+    if s:CanParseMakefile(a:buffer) && !empty(a:output) && !empty(l:cflags)
         let l:cflags = ale#c#ParseCFlagsFromMakeOutput(a:buffer, a:output)
     endif
 
@@ -349,11 +502,14 @@ function! ale#c#GetCFlags(buffer, output) abort
 endfunction
 
 function! ale#c#GetMakeCommand(buffer) abort
-    if ale#Var(a:buffer, 'c_parse_makefile')
-        let l:makefile_path = ale#path#FindNearestFile(a:buffer, 'Makefile')
+    if s:CanParseMakefile(a:buffer)
+        let l:path = ale#path#FindNearestFile(a:buffer, 'Makefile')
+
+        if !empty(l:path)
+            let l:always_make = ale#Var(a:buffer, 'c_always_make')
 
-        if !empty(l:makefile_path)
-            return 'cd '. fnamemodify(l:makefile_path, ':p:h') . ' && make -n'
+            return ale#path#CdString(fnamemodify(l:path, ':h'))
+            \   . 'make -n' . (l:always_make ? ' --always-make' : '')
         endif
     endif
 
@@ -422,8 +578,3 @@ function! ale#c#IncludeOptions(include_paths) abort
 
     return join(l:option_list)
 endfunction
-
-let g:ale_c_build_dir_names = get(g:, 'ale_c_build_dir_names', [
-\   'build',
-\   'bin',
-\])
diff --git a/autoload/ale/code_action.vim b/autoload/ale/code_action.vim
index 60c3bbef..8c7263f3 100644
--- a/autoload/ale/code_action.vim
+++ b/autoload/ale/code_action.vim
@@ -24,6 +24,42 @@ function! ale#code_action#HandleCodeAction(code_action, should_save) abort
     endfor
 endfunction
 
+function! s:ChangeCmp(left, right) abort
+    if a:left.start.line < a:right.start.line
+        return -1
+    endif
+
+    if a:left.start.line > a:right.start.line
+        return 1
+    endif
+
+    if a:left.start.offset < a:right.start.offset
+        return -1
+    endif
+
+    if a:left.start.offset > a:right.start.offset
+        return 1
+    endif
+
+    if a:left.end.line < a:right.end.line
+        return -1
+    endif
+
+    if a:left.end.line > a:right.end.line
+        return 1
+    endif
+
+    if a:left.end.offset < a:right.end.offset
+        return -1
+    endif
+
+    if a:left.end.offset > a:right.end.offset
+        return 1
+    endif
+
+    return 0
+endfunction
+
 function! ale#code_action#ApplyChanges(filename, changes, should_save) abort
     let l:current_buffer = bufnr('')
     " The buffer is used to determine the fileformat, if available.
@@ -48,7 +84,8 @@ function! ale#code_action#ApplyChanges(filename, changes, should_save) abort
     let l:column_offset = 0
     let l:last_end_line = 0
 
-    for l:code_edit in a:changes
+    " Changes have to be sorted so we apply them from top-to-bottom.
+    for l:code_edit in sort(copy(a:changes), function('s:ChangeCmp'))
         if l:code_edit.start.line isnot l:last_end_line
             let l:column_offset = 0
         endif
diff --git a/autoload/ale/command.vim b/autoload/ale/command.vim
index 1bbc4f4c..8f497169 100644
--- a/autoload/ale/command.vim
+++ b/autoload/ale/command.vim
@@ -133,11 +133,36 @@ function! ale#command#EscapeCommandPart(command_part) abort
     return substitute(a:command_part, '%', '%%', 'g')
 endfunction
 
+" Format a filename, converting it with filename mappings, if non-empty,
+" and escaping it for putting into a command string.
+"
+" The filename can be modified.
+function! s:FormatFilename(filename, mappings, modifiers) abort
+    let l:filename = a:filename
+
+    if !empty(a:mappings)
+        let l:filename = ale#filename_mapping#Map(l:filename, a:mappings)
+    endif
+
+    if !empty(a:modifiers)
+        let l:filename = fnamemodify(l:filename, a:modifiers)
+    endif
+
+    return ale#Escape(l:filename)
+endfunction
+
 " Given a command string, replace every...
 " %s -> with the current filename
 " %t -> with the name of an unused file in a temporary directory
 " %% -> with a literal %
-function! ale#command#FormatCommand(buffer, executable, command, pipe_file_if_needed, input) abort
+function! ale#command#FormatCommand(
+\   buffer,
+\   executable,
+\   command,
+\   pipe_file_if_needed,
+\   input,
+\   mappings,
+\) abort
     let l:temporary_file = ''
     let l:command = a:command
 
@@ -154,14 +179,24 @@ function! ale#command#FormatCommand(buffer, executable, command, pipe_file_if_ne
     " file.
     if l:command =~# '%s'
         let l:filename = fnamemodify(bufname(a:buffer), ':p')
-        let l:command = substitute(l:command, '%s', '\=ale#Escape(l:filename)', 'g')
+        let l:command = substitute(
+        \   l:command,
+        \   '\v\%s(%(:h|:t|:r|:e)*)',
+        \   '\=s:FormatFilename(l:filename, a:mappings, submatch(1))',
+        \   'g'
+        \)
     endif
 
     if a:input isnot v:false && l:command =~# '%t'
         " Create a temporary filename, <temp_dir>/<original_basename>
         " The file itself will not be created by this function.
         let l:temporary_file = s:TemporaryFilename(a:buffer)
-        let l:command = substitute(l:command, '%t', '\=ale#Escape(l:temporary_file)', 'g')
+        let l:command = substitute(
+        \   l:command,
+        \   '\v\%t(%(:h|:t|:r|:e)*)',
+        \   '\=s:FormatFilename(l:temporary_file, a:mappings, submatch(1))',
+        \   'g'
+        \)
     endif
 
     " Finish formatting so %% becomes %.
@@ -265,6 +300,7 @@ function! ale#command#Run(buffer, command, Callback, ...) abort
     \   a:command,
     \   get(l:options, 'read_buffer', 0),
     \   get(l:options, 'input', v:null),
+    \   get(l:options, 'filename_mappings', []),
     \)
     let l:command = ale#job#PrepareCommand(a:buffer, l:command)
     let l:job_options = {
diff --git a/autoload/ale/completion.vim b/autoload/ale/completion.vim
index bffcdc8a..bdade95c 100644
--- a/autoload/ale/completion.vim
+++ b/autoload/ale/completion.vim
@@ -5,7 +5,7 @@ scriptencoding utf-8
 " The omnicompletion menu is shown through a special Plug mapping which is
 " only valid in Insert mode. This way, feedkeys() won't send these keys if you
 " quit Insert mode quickly enough.
-inoremap <silent> <Plug>(ale_show_completion_menu) <C-x><C-o>
+inoremap <silent> <Plug>(ale_show_completion_menu) <C-x><C-o><C-p>
 " If we hit the key sequence in normal mode, then we won't show the menu, so
 " we should restore the old settings right away.
 nnoremap <silent> <Plug>(ale_show_completion_menu) :call ale#completion#RestoreCompletionOptions()<CR>
@@ -188,7 +188,13 @@ function! ale#completion#GetTriggerCharacter(filetype, prefix) abort
     return ''
 endfunction
 
-function! ale#completion#Filter(buffer, filetype, suggestions, prefix) abort
+function! ale#completion#Filter(
+\   buffer,
+\   filetype,
+\   suggestions,
+\   prefix,
+\   exact_prefix_match,
+\) abort
     let l:excluded_words = ale#Var(a:buffer, 'completion_excluded_words')
 
     if empty(a:prefix)
@@ -215,10 +221,17 @@ function! ale#completion#Filter(buffer, filetype, suggestions, prefix) abort
                 " Dictionaries is accepted here.
                 let l:word = type(l:item) is v:t_string ? l:item : l:item.word
 
-                " Add suggestions if the suggestion starts with a
-                " case-insensitive match for the prefix.
-                if l:word[: len(a:prefix) - 1] is? a:prefix
-                    call add(l:filtered_suggestions, l:item)
+                if a:exact_prefix_match
+                    " Add suggestions if the word is an exact match.
+                    if l:word is# a:prefix
+                        call add(l:filtered_suggestions, l:item)
+                    endif
+                else
+                    " Add suggestions if the suggestion starts with a
+                    " case-insensitive match for the prefix.
+                    if l:word[: len(a:prefix) - 1] is? a:prefix
+                        call add(l:filtered_suggestions, l:item)
+                    endif
                 endif
             endfor
         endif
@@ -241,21 +254,17 @@ function! ale#completion#Filter(buffer, filetype, suggestions, prefix) abort
     return l:filtered_suggestions
 endfunction
 
-function! s:ReplaceCompletionOptions() abort
-    let l:source = get(get(b:, 'ale_completion_info', {}), 'source', '')
-
-    if l:source is# 'ale-automatic' || l:source is# 'ale-manual'
-        " Remember the old omnifunc value, if there is one.
-        " If we don't store an old one, we'll just never reset the option.
-        " This will stop some random exceptions from appearing.
-        if !exists('b:ale_old_omnifunc') && !empty(&l:omnifunc)
-            let b:ale_old_omnifunc = &l:omnifunc
-        endif
-
-        let &l:omnifunc = 'ale#completion#AutomaticOmniFunc'
+function! s:ReplaceCompletionOptions(source) abort
+    " Remember the old omnifunc value, if there is one.
+    " If we don't store an old one, we'll just never reset the option.
+    " This will stop some random exceptions from appearing.
+    if !exists('b:ale_old_omnifunc') && !empty(&l:omnifunc)
+        let b:ale_old_omnifunc = &l:omnifunc
     endif
 
-    if l:source is# 'ale-automatic'
+    let &l:omnifunc = 'ale#completion#AutomaticOmniFunc'
+
+    if a:source is# 'ale-automatic'
         if !exists('b:ale_old_completeopt')
             let b:ale_old_completeopt = &l:completeopt
         endif
@@ -318,41 +327,70 @@ function! ale#completion#AutomaticOmniFunc(findstart, base) abort
     else
         let l:result = ale#completion#GetCompletionResult()
 
-        call s:ReplaceCompletionOptions()
+        let l:source = get(get(b:, 'ale_completion_info', {}), 'source', '')
+
+        if l:source is# 'ale-automatic' || l:source is# 'ale-manual'
+            call s:ReplaceCompletionOptions(l:source)
+        endif
 
         return l:result isnot v:null ? l:result : []
     endif
 endfunction
 
+function! s:OpenCompletionMenu(...) abort
+    if !&l:paste
+        call ale#util#FeedKeys("\<Plug>(ale_show_completion_menu)")
+    endif
+endfunction
+
 function! ale#completion#Show(result) abort
-    if ale#util#Mode() isnot# 'i'
+    let l:source = get(get(b:, 'ale_completion_info', {}), 'source', '')
+
+    if ale#util#Mode() isnot# 'i' && l:source isnot# 'ale-import'
         return
     endif
 
-    " Set the list in the buffer, temporarily replace omnifunc with our
-    " function, and then start omni-completion.
+    " Set the list in the buffer.
     let b:ale_completion_result = a:result
 
     " Don't try to open the completion menu if there's nothing to show.
     if empty(b:ale_completion_result)
+        if l:source is# 'ale-import'
+            " If we ran completion from :ALEImport,
+            " tell the user that nothing is going to happen.
+            call s:message('No possible imports found.')
+        endif
+
         return
     endif
 
     " Replace completion options shortly before opening the menu.
-    call s:ReplaceCompletionOptions()
-
-    let l:source = get(get(b:, 'ale_completion_info', {}), 'source', '')
-
     if l:source is# 'ale-automatic' || l:source is# 'ale-manual'
-        call timer_start(
-        \   0,
-        \   {-> ale#util#FeedKeys("\<Plug>(ale_show_completion_menu)")}
-        \)
+        call s:ReplaceCompletionOptions(l:source)
+
+        call timer_start(0, function('s:OpenCompletionMenu'))
     endif
 
     if l:source is# 'ale-callback'
         call b:CompleteCallback(b:ale_completion_result)
     endif
+
+    if l:source is# 'ale-import'
+        call ale#completion#HandleUserData(b:ale_completion_result[0])
+
+        let l:text_changed = '' . g:ale_lint_on_text_changed
+
+        " Check the buffer again right away, if linting is enabled.
+        if g:ale_enabled
+        \&& (
+        \   l:text_changed is# '1'
+        \   || l:text_changed is# 'always'
+        \   || l:text_changed is# 'normal'
+        \   || l:text_changed is# 'insert'
+        \)
+            call ale#Queue(0, '')
+        endif
+    endif
 endfunction
 
 function! ale#completion#GetAllTriggers() abort
@@ -383,14 +421,18 @@ endfunction
 function! s:CompletionStillValid(request_id) abort
     let [l:line, l:column] = getpos('.')[1:2]
 
-    return ale#util#Mode() is# 'i'
-    \&& has_key(b:, 'ale_completion_info')
+    return has_key(b:, 'ale_completion_info')
+    \&& (
+    \   ale#util#Mode() is# 'i'
+    \   || b:ale_completion_info.source is# 'ale-import'
+    \)
     \&& b:ale_completion_info.request_id == a:request_id
     \&& b:ale_completion_info.line == l:line
     \&& (
     \   b:ale_completion_info.column == l:column
     \   || b:ale_completion_info.source is# 'ale-omnifunc'
     \   || b:ale_completion_info.source is# 'ale-callback'
+    \   || b:ale_completion_info.source is# 'ale-import'
     \)
 endfunction
 
@@ -415,15 +457,26 @@ function! ale#completion#ParseTSServerCompletionEntryDetails(response) abort
     let l:buffer = bufnr('')
     let l:results = []
     let l:names_with_details = []
+    let l:info = get(b:, 'ale_completion_info', {})
 
     for l:suggestion in a:response.body
         let l:displayParts = []
+        let l:local_name = v:null
 
         for l:action in get(l:suggestion, 'codeActions', [])
             call add(l:displayParts, l:action.description . ' ')
         endfor
 
         for l:part in l:suggestion.displayParts
+            " Stop on stop on line breaks for the menu.
+            if get(l:part, 'kind') is# 'lineBreak'
+                break
+            endif
+
+            if get(l:part, 'kind') is# 'localName'
+                let l:local_name = l:part.text
+            endif
+
             call add(l:displayParts, l:part.text)
         endfor
 
@@ -436,11 +489,18 @@ function! ale#completion#ParseTSServerCompletionEntryDetails(response) abort
 
         " See :help complete-items
         let l:result = {
-        \   'word': l:suggestion.name,
+        \   'word': (
+        \       l:suggestion.name is# 'default'
+        \       && l:suggestion.kind is# 'alias'
+        \       && !empty(l:local_name)
+        \           ? l:local_name
+        \           : l:suggestion.name
+        \   ),
         \   'kind': ale#completion#GetCompletionSymbols(l:suggestion.kind),
         \   'icase': 1,
         \   'menu': join(l:displayParts, ''),
-        \   'dup': g:ale_completion_autoimport,
+        \   'dup': get(l:info, 'additional_edits_only', 0)
+        \       ||  g:ale_completion_autoimport,
         \   'info': join(l:documentationParts, ''),
         \}
 
@@ -450,7 +510,12 @@ function! ale#completion#ParseTSServerCompletionEntryDetails(response) abort
             \ })
         endif
 
-        call add(l:results, l:result)
+        " Include this item if we'll accept any items,
+        " or if we only want items with additional edits, and this has them.
+        if !get(l:info, 'additional_edits_only', 0)
+        \|| has_key(l:result, 'user_data')
+            call add(l:results, l:result)
+        endif
     endfor
 
     let l:names = getbufvar(l:buffer, 'ale_tsserver_completion_names', [])
@@ -524,7 +589,11 @@ function! ale#completion#ParseLSPCompletions(response) abort
 
         " Don't use LSP items with additional text edits when autoimport for
         " completions is turned off.
-        if has_key(l:item, 'additionalTextEdits') && !g:ale_completion_autoimport
+        if !empty(get(l:item, 'additionalTextEdits'))
+        \&& !(
+        \   get(l:info, 'additional_edits_only', 0)
+        \   || g:ale_completion_autoimport
+        \)
             continue
         endif
 
@@ -546,38 +615,50 @@ function! ale#completion#ParseLSPCompletions(response) abort
             let l:text_changes = []
 
             for l:edit in l:item.additionalTextEdits
-                let l:range = l:edit.range
                 call add(l:text_changes, {
                 \ 'start': {
-                \   'line': l:range.start.line + 1,
-                \   'offset': l:range.start.character + 1,
+                \   'line': l:edit.range.start.line + 1,
+                \   'offset': l:edit.range.start.character + 1,
                 \ },
                 \ 'end': {
-                \   'line': l:range.end.line + 1,
-                \   'offset': l:range.end.character + 1,
+                \   'line': l:edit.range.end.line + 1,
+                \   'offset': l:edit.range.end.character + 1,
                 \ },
                 \ 'newText': l:edit.newText,
                 \})
             endfor
 
-            let l:changes = [{
-            \ 'fileName': expand('#' . l:buffer . ':p'),
-            \ 'textChanges': l:text_changes,
-            \}]
-            \
-            let l:result.user_data = json_encode({
-            \   'codeActions': [{
-            \       'description': 'completion',
-            \       'changes': l:changes,
-            \   }],
-            \ })
+            if !empty(l:text_changes)
+                let l:result.user_data = json_encode({
+                \   'codeActions': [{
+                \       'description': 'completion',
+                \       'changes': [
+                \           {
+                \               'fileName': expand('#' . l:buffer . ':p'),
+                \               'textChanges': l:text_changes,
+                \           }
+                \       ],
+                \   }],
+                \})
+            endif
         endif
 
-        call add(l:results, l:result)
+        " Include this item if we'll accept any items,
+        " or if we only want items with additional edits, and this has them.
+        if !get(l:info, 'additional_edits_only', 0)
+        \|| has_key(l:result, 'user_data')
+            call add(l:results, l:result)
+        endif
     endfor
 
     if has_key(l:info, 'prefix')
-        let l:results = ale#completion#Filter(l:buffer, &filetype, l:results, l:info.prefix)
+        let l:results = ale#completion#Filter(
+        \   l:buffer,
+        \   &filetype,
+        \   l:results,
+        \   l:info.prefix,
+        \   get(l:info, 'additional_edits_only', 0),
+        \)
     endif
 
     return l:results[: g:ale_completion_max_suggestions - 1]
@@ -601,13 +682,18 @@ function! ale#completion#HandleTSServerResponse(conn_id, response) abort
         \   &filetype,
         \   ale#completion#ParseTSServerCompletions(a:response),
         \   b:ale_completion_info.prefix,
+        \   get(b:ale_completion_info, 'additional_edits_only', 0),
         \)[: g:ale_completion_max_suggestions - 1]
 
         " We need to remember some names for tsserver, as it doesn't send
         " details back for everything we send.
         call setbufvar(l:buffer, 'ale_tsserver_completion_names', l:names)
 
-        if !empty(l:names)
+        if empty(l:names)
+            " Response with no results now and skip making a redundant request
+            " for nothing.
+            call ale#completion#Show([])
+        else
             let l:identifiers = []
 
             for l:name in l:names
@@ -681,7 +767,8 @@ function! s:OnReady(linter, lsp_details) abort
         \   b:ale_completion_info.line,
         \   b:ale_completion_info.column,
         \   b:ale_completion_info.prefix,
-        \   g:ale_completion_autoimport,
+        \   get(b:ale_completion_info, 'additional_edits_only', 0)
+        \       || g:ale_completion_autoimport,
         \)
     else
         " Send a message saying the buffer has changed first, otherwise
@@ -740,9 +827,19 @@ function! ale#completion#GetCompletions(...) abort
         let b:CompleteCallback = l:CompleteCallback
     endif
 
-    let [l:line, l:column] = getpos('.')[1:2]
+    if has_key(l:options, 'line') && has_key(l:options, 'column')
+        " Use a provided line and column, if given.
+        let l:line = l:options.line
+        let l:column = l:options.column
+    else
+        let [l:line, l:column] = getpos('.')[1:2]
+    endif
 
-    let l:prefix = ale#completion#GetPrefix(&filetype, l:line, l:column)
+    if has_key(l:options, 'prefix')
+        let l:prefix = l:options.prefix
+    else
+        let l:prefix = ale#completion#GetPrefix(&filetype, l:line, l:column)
+    endif
 
     if l:source is# 'ale-automatic' && empty(l:prefix)
         return 0
@@ -761,6 +858,11 @@ function! ale#completion#GetCompletions(...) abort
     \}
     unlet! b:ale_completion_result
 
+    if has_key(l:options, 'additional_edits_only')
+        let b:ale_completion_info.additional_edits_only =
+        \   l:options.additional_edits_only
+    endif
+
     let l:buffer = bufnr('')
     let l:Callback = function('s:OnReady')
 
@@ -777,6 +879,37 @@ function! ale#completion#GetCompletions(...) abort
     return l:started
 endfunction
 
+function! s:message(message) abort
+    call ale#util#Execute('echom ' . string(a:message))
+endfunction
+
+" This function implements the :ALEImport command.
+function! ale#completion#Import() abort
+    let l:word = expand('<cword>')
+
+    if empty(l:word)
+        call s:message('Nothing to complete at cursor!')
+
+        return
+    endif
+
+    let [l:line, l:column] = getpos('.')[1:2]
+    let l:column = searchpos('\V' . escape(l:word, '/\'), 'bn', l:line)[1]
+
+    if l:column isnot 0
+        let l:started = ale#completion#GetCompletions('ale-import', {
+        \   'line': l:line,
+        \   'column': l:column,
+        \   'prefix': l:word,
+        \   'additional_edits_only': 1,
+        \})
+
+        if !l:started
+            call s:message('No completion providers are available.')
+        endif
+    endif
+endfunction
+
 function! ale#completion#OmniFunc(findstart, base) abort
     if a:findstart
         let l:started = ale#completion#GetCompletions('ale-omnifunc')
@@ -855,6 +988,7 @@ function! ale#completion#HandleUserData(completed_item) abort
     if l:source isnot# 'ale-automatic'
     \&& l:source isnot# 'ale-manual'
     \&& l:source isnot# 'ale-callback'
+    \&& l:source isnot# 'ale-import'
         return
     endif
 
@@ -884,6 +1018,8 @@ function! ale#completion#Done() abort
 endfunction
 
 augroup ALECompletionActions
+    autocmd!
+
     autocmd CompleteDone * call ale#completion#HandleUserData(v:completed_item)
 augroup END
 
diff --git a/autoload/ale/cursor.vim b/autoload/ale/cursor.vim
index 8c331c5c..9ca6fb15 100644
--- a/autoload/ale/cursor.vim
+++ b/autoload/ale/cursor.vim
@@ -39,6 +39,8 @@ function! ale#cursor#TruncatedEcho(original_message) abort
             endif
 
             exec 'echomsg l:message'
+        catch /E481/
+            " Do nothing if running from a visual selection.
         endtry
 
         " Reset the cursor position if we moved off the end of the line.
diff --git a/autoload/ale/definition.vim b/autoload/ale/definition.vim
index ffcd9d10..0c1fb7cf 100644
--- a/autoload/ale/definition.vim
+++ b/autoload/ale/definition.vim
@@ -135,10 +135,6 @@ function! s:GoToLSPDefinition(linter, options, capability) abort
 endfunction
 
 function! ale#definition#GoTo(options) abort
-    if !get(g:, 'ale_ignore_2_7_warnings') && has_key(a:options, 'deprecated_command')
-        execute 'echom '':' . a:options.deprecated_command . ' is deprecated. Use `let g:ale_ignore_2_7_warnings = 1` to disable this message.'''
-    endif
-
     for l:linter in ale#linter#Get(&filetype)
         if !empty(l:linter.lsp)
             call s:GoToLSPDefinition(l:linter, a:options, 'definition')
@@ -147,10 +143,6 @@ function! ale#definition#GoTo(options) abort
 endfunction
 
 function! ale#definition#GoToType(options) abort
-    if !get(g:, 'ale_ignore_2_7_warnings') && has_key(a:options, 'deprecated_command')
-        execute 'echom '':' . a:options.deprecated_command . ' is deprecated. Use `let g:ale_ignore_2_7_warnings = 1` to disable this message.'''
-    endif
-
     for l:linter in ale#linter#Get(&filetype)
         if !empty(l:linter.lsp)
             " TODO: handle typeDefinition for tsserver if supported by the
diff --git a/autoload/ale/engine.vim b/autoload/ale/engine.vim
index 491d3c2e..ae0354b8 100644
--- a/autoload/ale/engine.vim
+++ b/autoload/ale/engine.vim
@@ -4,6 +4,7 @@
 
 " Remapping of linter problems.
 let g:ale_type_map = get(g:, 'ale_type_map', {})
+let g:ale_filename_mappings = get(g:, 'ale_filename_mappings', {})
 
 if !has_key(s:, 'executable_cache_map')
     let s:executable_cache_map = {}
@@ -104,42 +105,6 @@ function! ale#engine#IsCheckingBuffer(buffer) abort
     \   || !empty(get(l:info, 'active_other_sources_list', []))
 endfunction
 
-" Register a temporary file to be managed with the ALE engine for
-" a current job run.
-function! ale#engine#ManageFile(buffer, filename) abort
-    if !get(g:, 'ale_ignore_2_4_warnings')
-        execute 'echom ''ale#engine#ManageFile is deprecated. Use `let g:ale_ignore_2_4_warnings = 1` to disable this message.'''
-    endif
-
-    call ale#command#ManageFile(a:buffer, a:filename)
-endfunction
-
-" Same as the above, but manage an entire directory.
-function! ale#engine#ManageDirectory(buffer, directory) abort
-    if !get(g:, 'ale_ignore_2_4_warnings')
-        execute 'echom ''ale#engine#ManageDirectory is deprecated. Use `let g:ale_ignore_2_4_warnings = 1` to disable this message.'''
-    endif
-
-    call ale#command#ManageDirectory(a:buffer, a:directory)
-endfunction
-
-function! ale#engine#CreateFile(buffer) abort
-    if !get(g:, 'ale_ignore_2_4_warnings')
-        execute 'echom ''ale#engine#CreateFile is deprecated. Use `let g:ale_ignore_2_4_warnings = 1` to disable this message.'''
-    endif
-
-    return ale#command#CreateFile(a:buffer)
-endfunction
-
-" Create a new temporary directory and manage it in one go.
-function! ale#engine#CreateDirectory(buffer) abort
-    if !get(g:, 'ale_ignore_2_4_warnings')
-        execute 'echom ''ale#engine#CreateDirectory is deprecated. Use `let g:ale_ignore_2_4_warnings = 1` to disable this message.'''
-    endif
-
-    return ale#command#CreateDirectory(a:buffer)
-endfunction
-
 function! ale#engine#HandleLoclist(linter_name, buffer, loclist, from_other_source) abort
     let l:info = get(g:ale_buffer_info, a:buffer, {})
 
@@ -192,7 +157,6 @@ function! s:HandleExit(job_info, buffer, output, data) abort
 
     let l:linter = a:job_info.linter
     let l:executable = a:job_info.executable
-    let l:next_chain_index = a:job_info.next_chain_index
 
     " Remove this job from the list.
     call ale#engine#MarkLinterInactive(l:buffer_info, l:linter.name)
@@ -207,20 +171,6 @@ function! s:HandleExit(job_info, buffer, output, data) abort
         call remove(a:output, -1)
     endif
 
-    if l:next_chain_index < len(get(l:linter, 'command_chain', []))
-        let [l:command, l:options] = ale#engine#ProcessChain(
-        \   a:buffer,
-        \   l:executable,
-        \   l:linter,
-        \   l:next_chain_index,
-        \   a:output,
-        \)
-
-        call s:RunJob(l:command, l:options)
-
-        return
-    endif
-
     try
         let l:loclist = ale#util#GetFunction(l:linter.callback)(a:buffer, a:output)
     " Handle the function being unknown, or being deleted.
@@ -307,6 +257,13 @@ function! s:RemapItemTypes(type_map, loclist) abort
 endfunction
 
 function! ale#engine#FixLocList(buffer, linter_name, from_other_source, loclist) abort
+    let l:mappings = ale#GetFilenameMappings(a:buffer, a:linter_name)
+
+    if !empty(l:mappings)
+        " We need to apply reverse filename mapping here.
+        let l:mappings = ale#filename_mapping#Invert(l:mappings)
+    endif
+
     let l:bufnr_map = {}
     let l:new_loclist = []
 
@@ -347,13 +304,19 @@ function! ale#engine#FixLocList(buffer, linter_name, from_other_source, loclist)
             let l:item.code = l:old_item.code
         endif
 
-        if has_key(l:old_item, 'filename')
-        \&& !ale#path#IsTempName(l:old_item.filename)
+        let l:old_name = get(l:old_item, 'filename', '')
+
+        " Map parsed from output to local filesystem files.
+        if !empty(l:old_name) && !empty(l:mappings)
+            let l:old_name = ale#filename_mapping#Map(l:old_name, l:mappings)
+        endif
+
+        if !empty(l:old_name) && !ale#path#IsTempName(l:old_name)
             " Use the filename given.
             " Temporary files are assumed to be for this buffer,
             " and the filename is not included then, because it looks bad
             " in the loclist window.
-            let l:filename = l:old_item.filename
+            let l:filename = l:old_name
             let l:item.filename = l:filename
 
             if has_key(l:old_item, 'bufnr')
@@ -454,20 +417,19 @@ function! s:RunJob(command, options) abort
     let l:buffer = a:options.buffer
     let l:linter = a:options.linter
     let l:output_stream = a:options.output_stream
-    let l:next_chain_index = a:options.next_chain_index
-    let l:read_buffer = a:options.read_buffer
+    let l:read_buffer = a:options.read_buffer && !a:options.lint_file
     let l:info = g:ale_buffer_info[l:buffer]
 
     let l:Callback = function('s:HandleExit', [{
     \   'linter': l:linter,
     \   'executable': l:executable,
-    \   'next_chain_index': l:next_chain_index,
     \}])
     let l:result = ale#command#Run(l:buffer, l:command, l:Callback, {
     \   'output_stream': l:output_stream,
     \   'executable': l:executable,
     \   'read_buffer': l:read_buffer,
-    \   'log_output': l:next_chain_index >= len(get(l:linter, 'command_chain', [])),
+    \   'log_output': 1,
+    \   'filename_mappings': ale#GetFilenameMappings(l:buffer, l:linter.name),
     \})
 
     " Only proceed if the job is being run.
@@ -482,68 +444,6 @@ function! s:RunJob(command, options) abort
     return 1
 endfunction
 
-" Determine which commands to run for a link in a command chain, or
-" just a regular command.
-function! ale#engine#ProcessChain(buffer, executable, linter, chain_index, input) abort
-    let l:output_stream = get(a:linter, 'output_stream', 'stdout')
-    let l:read_buffer = a:linter.read_buffer
-    let l:chain_index = a:chain_index
-    let l:input = a:input
-
-    while l:chain_index < len(a:linter.command_chain)
-        " Run a chain of commands, one asynchronous command after the other,
-        " so that many programs can be run in a sequence.
-        let l:chain_item = a:linter.command_chain[l:chain_index]
-
-        if l:chain_index == 0
-            " The first callback in the chain takes only a buffer number.
-            let l:command = ale#util#GetFunction(l:chain_item.callback)(
-            \   a:buffer
-            \)
-        else
-            " The second callback in the chain takes some input too.
-            let l:command = ale#util#GetFunction(l:chain_item.callback)(
-            \   a:buffer,
-            \   l:input
-            \)
-        endif
-
-        " If we have a command to run, execute that.
-        if !empty(l:command)
-            " The chain item can override the output_stream option.
-            if has_key(l:chain_item, 'output_stream')
-                let l:output_stream = l:chain_item.output_stream
-            endif
-
-            " The chain item can override the read_buffer option.
-            if has_key(l:chain_item, 'read_buffer')
-                let l:read_buffer = l:chain_item.read_buffer
-            elseif l:chain_index != len(a:linter.command_chain) - 1
-                " Don't read the buffer for commands besides the last one
-                " in the chain by default.
-                let l:read_buffer = 0
-            endif
-
-            break
-        endif
-
-        " Command chain items can return an empty string to indicate that
-        " a command should be skipped, so we should try the next item
-        " with no input.
-        let l:input = []
-        let l:chain_index += 1
-    endwhile
-
-    return [l:command, {
-    \   'executable': a:executable,
-    \   'buffer': a:buffer,
-    \   'linter': a:linter,
-    \   'output_stream': l:output_stream,
-    \   'next_chain_index': l:chain_index + 1,
-    \   'read_buffer': l:read_buffer,
-    \}]
-endfunction
-
 function! s:StopCurrentJobs(buffer, clear_lint_file_jobs) abort
     let l:info = get(g:ale_buffer_info, a:buffer, {})
     call ale#command#StopJobs(a:buffer, 'linter')
@@ -608,10 +508,15 @@ function! s:AddProblemsFromOtherBuffers(buffer, linters) abort
     endif
 endfunction
 
-function! s:RunIfExecutable(buffer, linter, executable) abort
+function! s:RunIfExecutable(buffer, linter, lint_file, executable) abort
     if ale#command#IsDeferred(a:executable)
         let a:executable.result_callback = {
-        \   executable -> s:RunIfExecutable(a:buffer, a:linter, executable)
+        \   executable -> s:RunIfExecutable(
+        \       a:buffer,
+        \       a:linter,
+        \       a:lint_file,
+        \       executable
+        \   )
         \}
 
         return 1
@@ -619,29 +524,17 @@ function! s:RunIfExecutable(buffer, linter, executable) abort
 
     if ale#engine#IsExecutable(a:buffer, a:executable)
         " Use different job types for file or linter jobs.
-        let l:job_type = a:linter.lint_file ? 'file_linter' : 'linter'
+        let l:job_type = a:lint_file ? 'file_linter' : 'linter'
         call setbufvar(a:buffer, 'ale_job_type', l:job_type)
 
-        if has_key(a:linter, 'command_chain')
-            let [l:command, l:options] = ale#engine#ProcessChain(
-            \   a:buffer,
-            \   a:executable,
-            \   a:linter,
-            \   0,
-            \   []
-            \)
-
-            return s:RunJob(l:command, l:options)
-        endif
-
         let l:command = ale#linter#GetCommand(a:buffer, a:linter)
         let l:options = {
         \   'executable': a:executable,
         \   'buffer': a:buffer,
         \   'linter': a:linter,
         \   'output_stream': get(a:linter, 'output_stream', 'stdout'),
-        \   'next_chain_index': 1,
         \   'read_buffer': a:linter.read_buffer,
+        \   'lint_file': a:lint_file,
         \}
 
         return s:RunJob(l:command, l:options)
@@ -653,33 +546,62 @@ endfunction
 " Run a linter for a buffer.
 "
 " Returns 1 if the linter was successfully run.
-function! s:RunLinter(buffer, linter) abort
+function! s:RunLinter(buffer, linter, lint_file) abort
     if !empty(a:linter.lsp)
         return ale#lsp_linter#CheckWithLSP(a:buffer, a:linter)
     else
         let l:executable = ale#linter#GetExecutable(a:buffer, a:linter)
 
-        return s:RunIfExecutable(a:buffer, a:linter, l:executable)
+        return s:RunIfExecutable(a:buffer, a:linter, a:lint_file, l:executable)
     endif
 
     return 0
 endfunction
 
-function! ale#engine#RunLinters(buffer, linters, should_lint_file) abort
-    " Initialise the buffer information if needed.
-    let l:new_buffer = ale#engine#InitBufferInfo(a:buffer)
-    call s:StopCurrentJobs(a:buffer, a:should_lint_file)
-    call s:RemoveProblemsForDisabledLinters(a:buffer, a:linters)
+function! s:GetLintFileValues(slots, Callback) abort
+    let l:deferred_list = []
+    let l:new_slots = []
 
-    " We can only clear the results if we aren't checking the buffer.
-    let l:can_clear_results = !ale#engine#IsCheckingBuffer(a:buffer)
+    for [l:lint_file, l:linter] in a:slots
+        while ale#command#IsDeferred(l:lint_file) && has_key(l:lint_file, 'value')
+            " If we've already computed the return value, use it.
+            let l:lint_file = l:lint_file.value
+        endwhile
 
-    silent doautocmd <nomodeline> User ALELintPre
+        if ale#command#IsDeferred(l:lint_file)
+            " If we are going to return the result later, wait for it.
+            call add(l:deferred_list, l:lint_file)
+        else
+            " If we have the value now, coerce it to 0 or 1.
+            let l:lint_file = l:lint_file is 1
+        endif
 
-    for l:linter in a:linters
+        call add(l:new_slots, [l:lint_file, l:linter])
+    endfor
+
+    if !empty(l:deferred_list)
+        for l:deferred in l:deferred_list
+            let l:deferred.result_callback =
+            \   {-> s:GetLintFileValues(l:new_slots, a:Callback)}
+        endfor
+    else
+        call a:Callback(l:new_slots)
+    endif
+endfunction
+
+function! s:RunLinters(
+\   buffer,
+\   slots,
+\   should_lint_file,
+\   new_buffer,
+\   can_clear_results
+\) abort
+    let l:can_clear_results = a:can_clear_results
+
+    for [l:lint_file, l:linter] in a:slots
         " Only run lint_file linters if we should.
-        if !l:linter.lint_file || a:should_lint_file
-            if s:RunLinter(a:buffer, l:linter)
+        if !l:lint_file || a:should_lint_file
+            if s:RunLinter(a:buffer, l:linter, l:lint_file)
                 " If a single linter ran, we shouldn't clear everything.
                 let l:can_clear_results = 0
             endif
@@ -694,11 +616,49 @@ function! ale#engine#RunLinters(buffer, linters, should_lint_file) abort
     " disabled, or ALE itself is disabled.
     if l:can_clear_results
         call ale#engine#SetResults(a:buffer, [])
-    elseif l:new_buffer
-        call s:AddProblemsFromOtherBuffers(a:buffer, a:linters)
+    elseif a:new_buffer
+        call s:AddProblemsFromOtherBuffers(
+        \   a:buffer,
+        \   map(copy(a:slots), 'v:val[1]')
+        \)
     endif
 endfunction
 
+function! ale#engine#RunLinters(buffer, linters, should_lint_file) abort
+    " Initialise the buffer information if needed.
+    let l:new_buffer = ale#engine#InitBufferInfo(a:buffer)
+    call s:StopCurrentJobs(a:buffer, a:should_lint_file)
+    call s:RemoveProblemsForDisabledLinters(a:buffer, a:linters)
+
+    " We can only clear the results if we aren't checking the buffer.
+    let l:can_clear_results = !ale#engine#IsCheckingBuffer(a:buffer)
+
+    silent doautocmd <nomodeline> User ALELintPre
+
+    " Handle `lint_file` callbacks first.
+    let l:linter_slots = []
+
+    for l:linter in a:linters
+        let l:LintFile = l:linter.lint_file
+
+        if type(l:LintFile) is v:t_func
+            let l:LintFile = l:LintFile(a:buffer)
+        endif
+
+        call add(l:linter_slots, [l:LintFile, l:linter])
+    endfor
+
+    call s:GetLintFileValues(l:linter_slots, {
+    \   new_slots -> s:RunLinters(
+    \       a:buffer,
+    \       new_slots,
+    \       a:should_lint_file,
+    \       l:new_buffer,
+    \       l:can_clear_results,
+    \   )
+    \})
+endfunction
+
 " Clean up a buffer.
 "
 " This function will stop all current jobs for the buffer,
diff --git a/autoload/ale/events.vim b/autoload/ale/events.vim
index 731e36f2..3568c117 100644
--- a/autoload/ale/events.vim
+++ b/autoload/ale/events.vim
@@ -105,11 +105,11 @@ function! ale#events#Init() abort
 
         if g:ale_enabled
             if l:text_changed is? 'always' || l:text_changed is# '1'
-                autocmd TextChanged,TextChangedI * call ale#Queue(g:ale_lint_delay)
+                autocmd TextChanged,TextChangedI * call ale#Queue(ale#Var(str2nr(expand('<abuf>')), 'lint_delay'))
             elseif l:text_changed is? 'normal'
-                autocmd TextChanged * call ale#Queue(g:ale_lint_delay)
+                autocmd TextChanged * call ale#Queue(ale#Var(str2nr(expand('<abuf>')), 'lint_delay'))
             elseif l:text_changed is? 'insert'
-                autocmd TextChangedI * call ale#Queue(g:ale_lint_delay)
+                autocmd TextChangedI * call ale#Queue(ale#Var(str2nr(expand('<abuf>')), 'lint_delay'))
             endif
 
             if g:ale_lint_on_enter
diff --git a/autoload/ale/filename_mapping.vim b/autoload/ale/filename_mapping.vim
new file mode 100644
index 00000000..76d47acc
--- /dev/null
+++ b/autoload/ale/filename_mapping.vim
@@ -0,0 +1,22 @@
+" Author: w0rp <devw0rp@gmail.com>
+" Description: Logic for handling mappings between files
+
+" Invert filesystem mappings so they can be mapped in reverse.
+function! ale#filename_mapping#Invert(filename_mappings) abort
+    return map(copy(a:filename_mappings), '[v:val[1], v:val[0]]')
+endfunction
+
+" Given a filename and some filename_mappings, map a filename.
+function! ale#filename_mapping#Map(filename, filename_mappings) abort
+    let l:simplified_filename = ale#path#Simplify(a:filename)
+
+    for [l:mapping_from, l:mapping_to] in a:filename_mappings
+        let l:mapping_from = ale#path#Simplify(l:mapping_from)
+
+        if l:simplified_filename[:len(l:mapping_from) - 1] is# l:mapping_from
+            return l:mapping_to . l:simplified_filename[len(l:mapping_from):]
+        endif
+    endfor
+
+    return a:filename
+endfunction
diff --git a/autoload/ale/fix.vim b/autoload/ale/fix.vim
index 69817b36..8b841b13 100644
--- a/autoload/ale/fix.vim
+++ b/autoload/ale/fix.vim
@@ -1,4 +1,8 @@
-call ale#Set('fix_on_save_ignore', {})
+" Author: w0rp <devw0rp@gmail.com>
+" Description: Functions for fixing code with programs, or other means.
+
+let g:ale_fix_on_save_ignore = get(g:, 'ale_fix_on_save_ignore', {})
+let g:ale_filename_mappings = get(g:, 'ale_filename_mappings', {})
 
 " Apply fixes queued up for buffers which may be hidden.
 " Vim doesn't let you modify hidden buffers.
@@ -11,22 +15,29 @@ function! ale#fix#ApplyQueuedFixes(buffer) abort
 
     call remove(g:ale_fix_buffer_data, a:buffer)
 
-    if l:data.changes_made
-        let l:new_lines = ale#util#SetBufferContents(a:buffer, l:data.output)
-
-        if l:data.should_save
-            if a:buffer is bufnr('')
-                if empty(&buftype)
-                    noautocmd :w!
+    try
+        if l:data.changes_made
+            let l:new_lines = ale#util#SetBufferContents(a:buffer, l:data.output)
+
+            if l:data.should_save
+                if a:buffer is bufnr('')
+                    if empty(&buftype)
+                        noautocmd :w!
+                    else
+                        set nomodified
+                    endif
                 else
-                    set nomodified
+                    call writefile(l:new_lines, expand('#' . a:buffer . ':p')) " no-custom-checks
+                    call setbufvar(a:buffer, '&modified', 0)
                 endif
-            else
-                call writefile(l:new_lines, expand('#' . a:buffer . ':p')) " no-custom-checks
-                call setbufvar(a:buffer, '&modified', 0)
             endif
         endif
-    endif
+    catch /E21/
+        " If we cannot modify the buffer now, try again later.
+        let g:ale_fix_buffer_data[a:buffer] = l:data
+
+        return
+    endtry
 
     if l:data.should_save
         let l:should_lint = ale#Var(a:buffer, 'fix_on_save')
@@ -90,7 +101,6 @@ function! s:HandleExit(job_info, buffer, job_output, data) abort
         let l:output = a:job_output
     endif
 
-    let l:ChainCallback = get(a:job_info, 'chain_with', v:null)
     let l:ProcessWith = get(a:job_info, 'process_with', v:null)
 
     " Post-process the output with a function if we have one.
@@ -102,27 +112,17 @@ function! s:HandleExit(job_info, buffer, job_output, data) abort
     " otherwise skip this job and use the input from before.
     "
     " We'll use the input from before for chained commands.
-    if l:ChainCallback is v:null && !empty(split(join(l:output)))
+    if !empty(split(join(l:output)))
         let l:input = l:output
     else
         let l:input = a:job_info.input
     endif
 
-    if l:ChainCallback isnot v:null && !get(g:, 'ale_ignore_2_4_warnings')
-        execute 'echom ''chain_with is deprecated. Use `let g:ale_ignore_2_4_warnings = 1` to disable this message.'''
-    endif
-
-    let l:next_index = l:ChainCallback is v:null
-    \   ? a:job_info.callback_index + 1
-    \   : a:job_info.callback_index
-
     call s:RunFixer({
     \   'buffer': a:buffer,
     \   'input': l:input,
-    \   'output': l:output,
     \   'callback_list': a:job_info.callback_list,
-    \   'callback_index': l:next_index,
-    \   'chain_callback': l:ChainCallback,
+    \   'callback_index': a:job_info.callback_index + 1,
     \})
 endfunction
 
@@ -135,6 +135,7 @@ function! s:RunJob(result, options) abort
 
     let l:buffer = a:options.buffer
     let l:input = a:options.input
+    let l:fixer_name = a:options.fixer_name
 
     if a:result is 0 || type(a:result) is v:t_list
         if type(a:result) is v:t_list
@@ -152,26 +153,21 @@ function! s:RunJob(result, options) abort
     endif
 
     let l:command = get(a:result, 'command', '')
-    let l:ChainWith = get(a:result, 'chain_with', v:null)
 
     if empty(l:command)
-        " If the command is empty, skip to the next item, or call the
-        " chain_with function.
+        " If the command is empty, skip to the next item.
         call s:RunFixer({
         \   'buffer': l:buffer,
         \   'input': l:input,
-        \   'callback_index': a:options.callback_index + (l:ChainWith is v:null),
+        \   'callback_index': a:options.callback_index,
         \   'callback_list': a:options.callback_list,
-        \   'chain_callback': l:ChainWith,
-        \   'output': [],
         \})
 
         return
     endif
 
     let l:read_temporary_file = get(a:result, 'read_temporary_file', 0)
-    " Default to piping the buffer for the last fixer in the chain.
-    let l:read_buffer = get(a:result, 'read_buffer', l:ChainWith is v:null)
+    let l:read_buffer = get(a:result, 'read_buffer', 1)
     let l:output_stream = get(a:result, 'output_stream', 'stdout')
 
     if l:read_temporary_file
@@ -180,7 +176,6 @@ function! s:RunJob(result, options) abort
 
     let l:Callback = function('s:HandleExit', [{
     \   'input': l:input,
-    \   'chain_with': l:ChainWith,
     \   'callback_index': a:options.callback_index,
     \   'callback_list': a:options.callback_list,
     \   'process_with': get(a:result, 'process_with', v:null),
@@ -192,6 +187,7 @@ function! s:RunJob(result, options) abort
     \   'read_buffer': l:read_buffer,
     \   'input': l:input,
     \   'log_output': 0,
+    \   'filename_mappings': ale#GetFilenameMappings(l:buffer, l:fixer_name),
     \})
 
     if empty(l:run_result)
@@ -215,32 +211,22 @@ function! s:RunFixer(options) abort
         return
     endif
 
-    let l:ChainCallback = get(a:options, 'chain_callback', v:null)
-
-    let l:Function = l:ChainCallback isnot v:null
-    \   ? ale#util#GetFunction(l:ChainCallback)
-    \   : a:options.callback_list[l:index]
+    let [l:fixer_name, l:Function] = a:options.callback_list[l:index]
 
     " Record new jobs started as fixer jobs.
     call setbufvar(l:buffer, 'ale_job_type', 'fixer')
 
-    if l:ChainCallback isnot v:null
-        " Chained commands accept (buffer, output, [input])
-        let l:result = ale#util#FunctionArgCount(l:Function) == 2
-        \   ? call(l:Function, [l:buffer, a:options.output])
-        \   : call(l:Function, [l:buffer, a:options.output, copy(l:input)])
-    else
-        " Regular fixer commands accept (buffer, [input])
-        let l:result = ale#util#FunctionArgCount(l:Function) == 1
-        \   ? call(l:Function, [l:buffer])
-        \   : call(l:Function, [l:buffer, copy(l:input)])
-    endif
+    " Regular fixer commands accept (buffer, [input])
+    let l:result = ale#util#FunctionArgCount(l:Function) == 1
+    \   ? call(l:Function, [l:buffer])
+    \   : call(l:Function, [l:buffer, copy(l:input)])
 
     call s:RunJob(l:result, {
     \   'buffer': l:buffer,
     \   'input': l:input,
     \   'callback_list': a:options.callback_list,
     \   'callback_index': l:index,
+    \   'fixer_name': l:fixer_name,
     \})
 endfunction
 
@@ -308,16 +294,24 @@ function! s:GetCallbacks(buffer, fixing_flag, fixers) abort
     " Variables with capital characters are needed, or Vim will complain about
     " funcref variables.
     for l:Item in l:callback_list
+        " Try to capture the names of registered fixer names, so we can use
+        " them for filename mapping or other purposes later.
+        let l:fixer_name = v:null
+
         if type(l:Item) is v:t_string
             let l:Func = ale#fix#registry#GetFunc(l:Item)
 
             if !empty(l:Func)
+                let l:fixer_name = l:Item
                 let l:Item = l:Func
             endif
         endif
 
         try
-            call add(l:corrected_list, ale#util#GetFunction(l:Item))
+            call add(l:corrected_list, [
+            \   l:fixer_name,
+            \   ale#util#GetFunction(l:Item)
+            \])
         catch /E475/
             " Rethrow exceptions for failing to get a function so we can print
             " a friendly message about it.
@@ -389,3 +383,4 @@ endfunction
 augroup ALEBufferFixGroup
     autocmd!
     autocmd BufEnter * call ale#fix#ApplyQueuedFixes(str2nr(expand('<abuf>')))
+augroup END
diff --git a/autoload/ale/fix/registry.vim b/autoload/ale/fix/registry.vim
index 3dc5c774..0a729cf9 100644
--- a/autoload/ale/fix/registry.vim
+++ b/autoload/ale/fix/registry.vim
@@ -175,11 +175,11 @@ let s:default_registry = {
 \       'suggested_filetypes': ['php'],
 \       'description': 'Fix PHP files with php-cs-fixer.',
 \   },
-\    'astyle': {
+\   'astyle': {
 \       'function': 'ale#fixers#astyle#Fix',
 \       'suggested_filetypes': ['c', 'cpp'],
 \       'description': 'Fix C/C++ with astyle.',
-\    },
+\   },
 \   'clangtidy': {
 \       'function': 'ale#fixers#clangtidy#Fix',
 \       'suggested_filetypes': ['c', 'cpp', 'objc'],
@@ -380,11 +380,21 @@ let s:default_registry = {
 \       'suggested_filetypes': ['nix'],
 \       'description': 'A formatter for Nix code',
 \   },
+\   'remark-lint': {
+\       'function': 'ale#fixers#remark_lint#Fix',
+\       'suggested_filetypes': ['markdown'],
+\       'description': 'Fix markdown files with remark-lint',
+\   },
 \   'html-beautify': {
 \       'function': 'ale#fixers#html_beautify#Fix',
 \       'suggested_filetypes': ['html', 'htmldjango'],
 \       'description': 'Fix HTML files with html-beautify.',
 \   },
+\   'dhall': {
+\       'function': 'ale#fixers#dhall#Fix',
+\       'suggested_filetypes': ['dhall'],
+\       'description': 'Fix Dhall files with dhall-format.',
+\   },
 \}
 
 " Reset the function registry to the default entries.
diff --git a/autoload/ale/fixers/dhall.vim b/autoload/ale/fixers/dhall.vim
new file mode 100644
index 00000000..18f6006c
--- /dev/null
+++ b/autoload/ale/fixers/dhall.vim
@@ -0,0 +1,23 @@
+" Author: Pat Brisbin <pbrisbin@gmail.com>
+" Description: Integration of dhall-format with ALE.
+
+call ale#Set('dhall_format_executable', 'dhall')
+
+function! ale#fixers#dhall#GetExecutable(buffer) abort
+    let l:executable = ale#Var(a:buffer, 'dhall_format_executable')
+
+    " Dhall is written in Haskell and commonly installed with Stack
+    return ale#handlers#haskell_stack#EscapeExecutable(l:executable, 'dhall')
+endfunction
+
+function! ale#fixers#dhall#Fix(buffer) abort
+    let l:executable = ale#fixers#dhall#GetExecutable(a:buffer)
+
+    return {
+    \   'command': l:executable
+    \       . ' format'
+    \       . ' --inplace'
+    \       . ' %t',
+    \   'read_temporary_file': 1,
+    \}
+endfunction
diff --git a/autoload/ale/fixers/latexindent.vim b/autoload/ale/fixers/latexindent.vim
index b0a0884a..54f1231e 100644
--- a/autoload/ale/fixers/latexindent.vim
+++ b/autoload/ale/fixers/latexindent.vim
@@ -10,9 +10,7 @@ function! ale#fixers#latexindent#Fix(buffer) abort
 
     return {
     \   'command': ale#Escape(l:executable)
-    \       . ' -l -w'
+    \       . ' -l'
     \       . (empty(l:options) ? '' : ' ' . l:options)
-    \       . ' %t',
-    \   'read_temporary_file': 1,
     \}
 endfunction
diff --git a/autoload/ale/fixers/ocamlformat.vim b/autoload/ale/fixers/ocamlformat.vim
index 9b7c3e12..b12d2eb9 100644
--- a/autoload/ale/fixers/ocamlformat.vim
+++ b/autoload/ale/fixers/ocamlformat.vim
@@ -5,14 +5,13 @@ call ale#Set('ocaml_ocamlformat_executable', 'ocamlformat')
 call ale#Set('ocaml_ocamlformat_options', '')
 
 function! ale#fixers#ocamlformat#Fix(buffer) abort
-    let l:filename = expand('#' . a:buffer . ':p')
     let l:executable = ale#Var(a:buffer, 'ocaml_ocamlformat_executable')
     let l:options = ale#Var(a:buffer, 'ocaml_ocamlformat_options')
 
     return {
     \   'command': ale#Escape(l:executable)
     \       . (empty(l:options) ? '' : ' ' . l:options)
-    \       . ' --name=' . ale#Escape(l:filename)
+    \       . ' --name=%s'
     \       . ' -'
     \}
 endfunction
diff --git a/autoload/ale/fixers/prettier.vim b/autoload/ale/fixers/prettier.vim
index 23120777..e0f4972e 100644
--- a/autoload/ale/fixers/prettier.vim
+++ b/autoload/ale/fixers/prettier.vim
@@ -34,6 +34,21 @@ function! ale#fixers#prettier#ProcessPrettierDOutput(buffer, output) abort
     return a:output
 endfunction
 
+function! ale#fixers#prettier#GetProjectRoot(buffer) abort
+    let l:config = ale#path#FindNearestFile(a:buffer, '.prettierignore')
+
+    if !empty(l:config)
+        return fnamemodify(l:config, ':h')
+    endif
+
+    " Fall back to the directory of the buffer
+    return fnamemodify(bufname(a:buffer), ':p:h')
+endfunction
+
+function! ale#fixers#prettier#CdProjectRoot(buffer) abort
+    return ale#path#CdString(ale#fixers#prettier#GetProjectRoot(a:buffer))
+endfunction
+
 function! ale#fixers#prettier#ApplyFixForVersion(buffer, version) abort
     let l:executable = ale#fixers#prettier#GetExecutable(a:buffer)
     let l:options = ale#Var(a:buffer, 'javascript_prettier_options')
@@ -97,7 +112,7 @@ function! ale#fixers#prettier#ApplyFixForVersion(buffer, version) abort
     " 1.4.0 is the first version with --stdin-filepath
     if ale#semver#GTE(a:version, [1, 4, 0])
         return {
-        \   'command': ale#path#BufferCdString(a:buffer)
+        \   'command': ale#fixers#prettier#CdProjectRoot(a:buffer)
         \       . ale#Escape(l:executable)
         \       . (!empty(l:options) ? ' ' . l:options : '')
         \       . ' --stdin-filepath %s --stdin',
diff --git a/autoload/ale/fixers/prettier_standard.vim b/autoload/ale/fixers/prettier_standard.vim
index b6e0a6f9..9d982ff6 100644
--- a/autoload/ale/fixers/prettier_standard.vim
+++ b/autoload/ale/fixers/prettier_standard.vim
@@ -17,8 +17,8 @@ function! ale#fixers#prettier_standard#Fix(buffer) abort
 
     return {
     \   'command': ale#Escape(ale#fixers#prettier_standard#GetExecutable(a:buffer))
-    \       . ' %t'
+    \       . ' --stdin'
+    \       . ' --stdin-filepath=%s'
     \       . ' ' . l:options,
-    \   'read_temporary_file': 1,
     \}
 endfunction
diff --git a/autoload/ale/fixers/remark_lint.vim b/autoload/ale/fixers/remark_lint.vim
new file mode 100644
index 00000000..3ce442f3
--- /dev/null
+++ b/autoload/ale/fixers/remark_lint.vim
@@ -0,0 +1,24 @@
+" Author: blyoa <blyoa110@gmail.com>
+" Description: Fixing files with remark-lint.
+
+call ale#Set('markdown_remark_lint_executable', 'remark')
+call ale#Set('markdown_remark_lint_use_global', get(g:, 'ale_use_global_executables', 0))
+call ale#Set('markdown_remark_lint_options', '')
+
+function! ale#fixers#remark_lint#GetExecutable(buffer) abort
+    return ale#node#FindExecutable(a:buffer, 'markdown_remark_lint', [
+    \   'node_modules/remark-cli/cli.js',
+    \   'node_modules/.bin/remark',
+    \])
+endfunction
+
+function! ale#fixers#remark_lint#Fix(buffer) abort
+    let l:executable = ale#fixers#remark_lint#GetExecutable(a:buffer)
+    let l:options = ale#Var(a:buffer, 'markdown_remark_lint_options')
+
+    return {
+    \   'command': ale#Escape(l:executable)
+    \       . (!empty(l:options) ? ' ' . l:options : ''),
+    \}
+endfunction
+
diff --git a/autoload/ale/fixers/rubocop.vim b/autoload/ale/fixers/rubocop.vim
index d9615256..cdfb014a 100644
--- a/autoload/ale/fixers/rubocop.vim
+++ b/autoload/ale/fixers/rubocop.vim
@@ -29,8 +29,7 @@ function! ale#fixers#rubocop#GetCommand(buffer) abort
     \   . (!empty(l:config) ? ' --config ' . ale#Escape(l:config) : '')
     \   . (!empty(l:options) ? ' ' . l:options : '')
     \   . (l:auto_correct_all ? ' --auto-correct-all' : ' --auto-correct')
-    \   . ' --force-exclusion --stdin '
-    \   . ale#Escape(expand('#' . a:buffer . ':p'))
+    \   . ' --force-exclusion --stdin %s'
 endfunction
 
 function! ale#fixers#rubocop#Fix(buffer) abort
diff --git a/autoload/ale/fixers/standard.vim b/autoload/ale/fixers/standard.vim
index cffa9f9d..46decebf 100644
--- a/autoload/ale/fixers/standard.vim
+++ b/autoload/ale/fixers/standard.vim
@@ -27,7 +27,7 @@ function! ale#fixers#standard#Fix(buffer) abort
     return {
     \   'command': ale#node#Executable(a:buffer, l:executable)
     \   . (!empty(l:options) ? ' ' . l:options : '')
-    \       . ' --fix %t',
+    \       . ' --fix --stdin < %s > %t',
     \   'read_temporary_file': 1,
     \}
 endfunction
diff --git a/autoload/ale/handlers/gcc.vim b/autoload/ale/handlers/gcc.vim
index ec16b977..0b37c98a 100644
--- a/autoload/ale/handlers/gcc.vim
+++ b/autoload/ale/handlers/gcc.vim
@@ -10,7 +10,7 @@ let s:pragma_error = '#pragma once in main file'
 " <stdin>:8:5: warning: conversion lacks type at end of format [-Wformat=]
 " <stdin>:10:27: error: invalid operands to binary - (have ‘int’ and ‘char *’)
 " -:189:7: note: $/${} is unnecessary on arithmetic variables. [SC2004]
-let s:pattern = '\v^([a-zA-Z]?:?[^:]+):(\d+):(\d+)?:? ([^:]+): (.+)$'
+let s:pattern = '\v^([a-zA-Z]?:?[^:]+):(\d+)?:?(\d+)?:? ([^:]+): (.+)$'
 let s:inline_pattern = '\v inlined from .* at \<stdin\>:(\d+):(\d+):$'
 
 function! s:IsHeaderFile(filename) abort
@@ -117,6 +117,23 @@ function! ale#handlers#gcc#HandleGCCFormat(buffer, lines) abort
             if !empty(l:output)
                 if !has_key(l:output[-1], 'detail')
                     let l:output[-1].detail = l:output[-1].text
+
+                    " handle macro expansion errors/notes
+                    if l:match[5] =~? '^in expansion of macro ‘\w*\w’$'
+                        " if the macro expansion is in the file we're in, add
+                        " the lnum and col keys to the previous error
+                        if l:match[1] is# '<stdin>'
+                        \ && !has_key(l:output[-1], 'col')
+                            let l:output[-1].lnum = str2nr(l:match[2])
+                            let l:output[-1].col = str2nr(l:match[3])
+                        else
+                            " the error is not in the current file, and since
+                            " macro expansion errors don't show the full path to
+                            " the error from the current file, we have to just
+                            " give out a generic error message
+                            let l:output[-1].text = 'Error found in macro expansion. See :ALEDetail'
+                        endif
+                    endif
                 endif
 
                 let l:output[-1].detail = l:output[-1].detail . "\n"
diff --git a/autoload/ale/handlers/sh.vim b/autoload/ale/handlers/sh.vim
index 75eaf71f..1e50cb89 100644
--- a/autoload/ale/handlers/sh.vim
+++ b/autoload/ale/handlers/sh.vim
@@ -4,17 +4,24 @@
 function! ale#handlers#sh#GetShellType(buffer) abort
     let l:bang_line = get(getbufline(a:buffer, 1), 0, '')
 
+    let l:command = ''
+
     " Take the shell executable from the hashbang, if we can.
     if l:bang_line[:1] is# '#!'
         " Remove options like -e, etc.
         let l:command = substitute(l:bang_line, ' --\?[a-zA-Z0-9]\+', '', 'g')
+    endif
 
-        for l:possible_shell in ['bash', 'dash', 'ash', 'tcsh', 'csh', 'zsh', 'ksh', 'sh']
-            if l:command =~# l:possible_shell . '\s*$'
-                return l:possible_shell
-            endif
-        endfor
+    " If we couldn't find a hashbang, try the filetype
+    if l:command is# ''
+        let l:command = &filetype
     endif
 
+    for l:possible_shell in ['bash', 'dash', 'ash', 'tcsh', 'csh', 'zsh', 'ksh', 'sh']
+        if l:command =~# l:possible_shell . '\s*$'
+            return l:possible_shell
+        endif
+    endfor
+
     return ''
 endfunction
diff --git a/autoload/ale/hover.vim b/autoload/ale/hover.vim
index 168ff424..38b4b866 100644
--- a/autoload/ale/hover.vim
+++ b/autoload/ale/hover.vim
@@ -264,7 +264,10 @@ function! s:OnReady(line, column, opt, linter, lsp_details) abort
         " hover position probably won't make sense.
         call ale#lsp#NotifyForChanges(l:id, l:buffer)
 
-        let l:column = min([a:column, len(getbufline(l:buffer, a:line)[0])])
+        let l:column = max([
+        \   min([a:column, len(getbufline(l:buffer, a:line)[0])]),
+        \   1,
+        \])
 
         let l:message = ale#lsp#message#Hover(l:buffer, a:line, l:column)
     endif
diff --git a/autoload/ale/linter.vim b/autoload/ale/linter.vim
index 0e935149..b483fc19 100644
--- a/autoload/ale/linter.vim
+++ b/autoload/ale/linter.vim
@@ -32,7 +32,7 @@ let s:default_ale_linter_aliases = {
 "
 " No linters are used for plaintext files by default.
 "
-" Only cargo is enabled for Rust by default.
+" Only cargo and rls are enabled for Rust by default.
 " rpmlint is disabled by default because it can result in code execution.
 " hhast is disabled by default because it executes code in the project root.
 "
@@ -46,7 +46,7 @@ let s:default_ale_linters = {
 \   'perl': ['perlcritic'],
 \   'perl6': [],
 \   'python': ['flake8', 'mypy', 'pylint', 'pyright'],
-\   'rust': ['cargo'],
+\   'rust': ['cargo', 'rls'],
 \   'spec': [],
 \   'text': [],
 \   'vue': ['eslint', 'vls'],
@@ -77,10 +77,6 @@ function! s:IsBoolean(value) abort
     return type(a:value) is v:t_number && (a:value == 0 || a:value == 1)
 endfunction
 
-function! s:LanguageGetter(buffer) dict abort
-    return l:self.language
-endfunction
-
 function! ale#linter#PreProcess(filetype, linter) abort
     if type(a:linter) isnot v:t_dict
         throw 'The linter object must be a Dictionary'
@@ -114,14 +110,7 @@ function! ale#linter#PreProcess(filetype, linter) abort
 
     if !l:needs_executable
         if has_key(a:linter, 'executable')
-        \|| has_key(a:linter, 'executable_callback')
-            throw '`executable` and `executable_callback` cannot be used when lsp == ''socket'''
-        endif
-    elseif has_key(a:linter, 'executable_callback')
-        let l:obj.executable_callback = a:linter.executable_callback
-
-        if !s:IsCallback(l:obj.executable_callback)
-            throw '`executable_callback` must be a callback if defined'
+            throw '`executable` cannot be used when lsp == ''socket'''
         endif
     elseif has_key(a:linter, 'executable')
         let l:obj.executable = a:linter.executable
@@ -131,54 +120,12 @@ function! ale#linter#PreProcess(filetype, linter) abort
             throw '`executable` must be a String or Function if defined'
         endif
     else
-        throw 'Either `executable` or `executable_callback` must be defined'
+        throw '`executable` must be defined'
     endif
 
     if !l:needs_command
         if has_key(a:linter, 'command')
-        \|| has_key(a:linter, 'command_callback')
-        \|| has_key(a:linter, 'command_chain')
-            throw '`command` and `command_callback` and `command_chain` cannot be used when lsp == ''socket'''
-        endif
-    elseif has_key(a:linter, 'command_chain')
-        let l:obj.command_chain = a:linter.command_chain
-
-        if type(l:obj.command_chain) isnot v:t_list
-            throw '`command_chain` must be a List'
-        endif
-
-        if empty(l:obj.command_chain)
-            throw '`command_chain` must contain at least one item'
-        endif
-
-        let l:link_index = 0
-
-        for l:link in l:obj.command_chain
-            let l:err_prefix = 'The `command_chain` item ' . l:link_index . ' '
-
-            if !s:IsCallback(get(l:link, 'callback'))
-                throw l:err_prefix . 'must define a `callback` function'
-            endif
-
-            if has_key(l:link, 'output_stream')
-                if type(l:link.output_stream) isnot v:t_string
-                \|| index(['stdout', 'stderr', 'both'], l:link.output_stream) < 0
-                    throw l:err_prefix . '`output_stream` flag must be '
-                    \   . "'stdout', 'stderr', or 'both'"
-                endif
-            endif
-
-            if has_key(l:link, 'read_buffer') && !s:IsBoolean(l:link.read_buffer)
-                throw l:err_prefix . 'value for `read_buffer` must be `0` or `1`'
-            endif
-
-            let l:link_index += 1
-        endfor
-    elseif has_key(a:linter, 'command_callback')
-        let l:obj.command_callback = a:linter.command_callback
-
-        if !s:IsCallback(l:obj.command_callback)
-            throw '`command_callback` must be a callback if defined'
+            throw '`command` cannot be used when lsp == ''socket'''
         endif
     elseif has_key(a:linter, 'command')
         let l:obj.command = a:linter.command
@@ -188,22 +135,12 @@ function! ale#linter#PreProcess(filetype, linter) abort
             throw '`command` must be a String or Function if defined'
         endif
     else
-        throw 'Either `command`, `executable_callback`, `command_chain` '
-        \   . 'must be defined'
-    endif
-
-    if (
-    \   has_key(a:linter, 'command')
-    \   + has_key(a:linter, 'command_chain')
-    \   + has_key(a:linter, 'command_callback')
-    \) > 1
-        throw 'Only one of `command`, `command_callback`, or `command_chain` '
-        \   . 'should be set'
+        throw '`command` must be defined'
     endif
 
     if !l:needs_address
-        if has_key(a:linter, 'address') || has_key(a:linter, 'address_callback')
-            throw '`address` or `address_callback` cannot be used when lsp != ''socket'''
+        if has_key(a:linter, 'address')
+            throw '`address` cannot be used when lsp != ''socket'''
         endif
     elseif has_key(a:linter, 'address')
         if type(a:linter.address) isnot v:t_string
@@ -212,41 +149,17 @@ function! ale#linter#PreProcess(filetype, linter) abort
         endif
 
         let l:obj.address = a:linter.address
-    elseif has_key(a:linter, 'address_callback')
-        let l:obj.address_callback = a:linter.address_callback
-
-        if !s:IsCallback(l:obj.address_callback)
-            throw '`address_callback` must be a callback if defined'
-        endif
     else
-        throw '`address` or `address_callback` must be defined for getting the LSP address'
+        throw '`address` must be defined for getting the LSP address'
     endif
 
     if l:needs_lsp_details
-        if has_key(a:linter, 'language_callback')
-            if has_key(a:linter, 'language')
-                throw 'Only one of `language` or `language_callback` '
-                \   . 'should be set'
-            endif
+        " Default to using the filetype as the language.
+        let l:obj.language = get(a:linter, 'language', a:filetype)
 
-            let l:obj.language_callback = get(a:linter, 'language_callback')
-
-            if !s:IsCallback(l:obj.language_callback)
-                throw '`language_callback` must be a callback for LSP linters'
-            endif
-        else
-            " Default to using the filetype as the language.
-            let l:Language = get(a:linter, 'language', a:filetype)
-
-            if type(l:Language) is v:t_string
-                " Make 'language_callback' return the 'language' value.
-                let l:obj.language = l:Language
-                let l:obj.language_callback = function('s:LanguageGetter')
-            elseif type(l:Language) is v:t_func
-                let l:obj.language_callback = l:Language
-            else
-                throw '`language` must be a String or Funcref'
-            endif
+        if type(l:obj.language) isnot v:t_string
+        \&& type(l:obj.language) isnot v:t_func
+            throw '`language` must be a String or Funcref if defined'
         endif
 
         if has_key(a:linter, 'project_root')
@@ -254,16 +167,10 @@ function! ale#linter#PreProcess(filetype, linter) abort
 
             if type(l:obj.project_root) isnot v:t_string
             \&& type(l:obj.project_root) isnot v:t_func
-                throw '`project_root` must be a String or Function if defined'
-            endif
-        elseif has_key(a:linter, 'project_root_callback')
-            let l:obj.project_root_callback = a:linter.project_root_callback
-
-            if !s:IsCallback(l:obj.project_root_callback)
-                throw '`project_root_callback` must be a callback if defined'
+                throw '`project_root` must be a String or Function'
             endif
         else
-            throw '`project_root` or `project_root_callback` must be defined for LSP linters'
+            throw '`project_root` must be defined for LSP linters'
         endif
 
         if has_key(a:linter, 'completion_filter')
@@ -274,37 +181,16 @@ function! ale#linter#PreProcess(filetype, linter) abort
             endif
         endif
 
-        if has_key(a:linter, 'initialization_options_callback')
-            if has_key(a:linter, 'initialization_options')
-                throw 'Only one of `initialization_options` or '
-                \   . '`initialization_options_callback` should be set'
-            endif
-
-            let l:obj.initialization_options_callback = a:linter.initialization_options_callback
-
-            if !s:IsCallback(l:obj.initialization_options_callback)
-                throw '`initialization_options_callback` must be a callback if defined'
-            endif
-        elseif has_key(a:linter, 'initialization_options')
+        if has_key(a:linter, 'initialization_options')
             let l:obj.initialization_options = a:linter.initialization_options
 
             if type(l:obj.initialization_options) isnot v:t_dict
             \&& type(l:obj.initialization_options) isnot v:t_func
-                throw '`initialization_options` must be a String or Function if defined'
+                throw '`initialization_options` must be a Dictionary or Function if defined'
             endif
         endif
 
-        if has_key(a:linter, 'lsp_config_callback')
-            if has_key(a:linter, 'lsp_config')
-                throw 'Only one of `lsp_config` or `lsp_config_callback` should be set'
-            endif
-
-            let l:obj.lsp_config_callback = a:linter.lsp_config_callback
-
-            if !s:IsCallback(l:obj.lsp_config_callback)
-                throw '`lsp_config_callback` must be a callback if defined'
-            endif
-        elseif has_key(a:linter, 'lsp_config')
+        if has_key(a:linter, 'lsp_config')
             if type(a:linter.lsp_config) isnot v:t_dict
             \&& type(a:linter.lsp_config) isnot v:t_func
                 throw '`lsp_config` must be a Dictionary or Function if defined'
@@ -325,21 +211,17 @@ function! ale#linter#PreProcess(filetype, linter) abort
     " file on disk.
     let l:obj.lint_file = get(a:linter, 'lint_file', 0)
 
-    if !s:IsBoolean(l:obj.lint_file)
-        throw '`lint_file` must be `0` or `1`'
+    if !s:IsBoolean(l:obj.lint_file) && type(l:obj.lint_file) isnot v:t_func
+        throw '`lint_file` must be `0`, `1`, or a Function'
     endif
 
     " An option indicating that the buffer should be read.
-    let l:obj.read_buffer = get(a:linter, 'read_buffer', !l:obj.lint_file)
+    let l:obj.read_buffer = get(a:linter, 'read_buffer', 1)
 
     if !s:IsBoolean(l:obj.read_buffer)
         throw '`read_buffer` must be `0` or `1`'
     endif
 
-    if l:obj.lint_file && l:obj.read_buffer
-        throw 'Only one of `lint_file` or `read_buffer` can be `1`'
-    endif
-
     let l:obj.aliases = get(a:linter, 'aliases', [])
 
     if type(l:obj.aliases) isnot v:t_list
@@ -347,14 +229,6 @@ function! ale#linter#PreProcess(filetype, linter) abort
         throw '`aliases` must be a List of String values'
     endif
 
-    for l:key in filter(keys(a:linter), 'v:val[-9:] is# ''_callback'' || v:val is# ''command_chain''')
-        if !get(g:, 'ale_ignore_2_4_warnings')
-            execute 'echom l:key . '' is deprecated. Use `let g:ale_ignore_2_4_warnings = 1` to disable this message.'''
-        endif
-
-        break
-    endfor
-
     return l:obj
 endfunction
 
@@ -522,9 +396,7 @@ endfunction
 
 " Given a buffer and linter, get the executable String for the linter.
 function! ale#linter#GetExecutable(buffer, linter) abort
-    let l:Executable = has_key(a:linter, 'executable_callback')
-    \   ? function(a:linter.executable_callback)
-    \   : a:linter.executable
+    let l:Executable = a:linter.executable
 
     return type(l:Executable) is v:t_func
     \   ? l:Executable(a:buffer)
@@ -532,24 +404,21 @@ function! ale#linter#GetExecutable(buffer, linter) abort
 endfunction
 
 " Given a buffer and linter, get the command String for the linter.
-" The command_chain key is not supported.
 function! ale#linter#GetCommand(buffer, linter) abort
-    let l:Command = has_key(a:linter, 'command_callback')
-    \   ? function(a:linter.command_callback)
-    \   : a:linter.command
+    let l:Command = a:linter.command
 
-    return type(l:Command) is v:t_func
-    \   ? l:Command(a:buffer)
-    \   : l:Command
+    return type(l:Command) is v:t_func ? l:Command(a:buffer) : l:Command
 endfunction
 
 " Given a buffer and linter, get the address for connecting to the server.
 function! ale#linter#GetAddress(buffer, linter) abort
-    let l:Address = has_key(a:linter, 'address_callback')
-    \   ? function(a:linter.address_callback)
-    \   : a:linter.address
+    let l:Address = a:linter.address
+
+    return type(l:Address) is v:t_func ? l:Address(a:buffer) : l:Address
+endfunction
+
+function! ale#linter#GetLanguage(buffer, linter) abort
+    let l:Language = a:linter.language
 
-    return type(l:Address) is v:t_func
-    \   ? l:Address(a:buffer)
-    \   : l:Address
+    return type(l:Language) is v:t_func ? l:Language(a:buffer) : l:Language
 endfunction
diff --git a/autoload/ale/lsp.vim b/autoload/ale/lsp.vim
index ae8fd51d..7d99e9d2 100644
--- a/autoload/ale/lsp.vim
+++ b/autoload/ale/lsp.vim
@@ -64,6 +64,9 @@ endfunction
 
 " Used only in tests.
 function! ale#lsp#GetConnections() abort
+    " This command will throw from the sandbox.
+    let &l:equalprg=&l:equalprg
+
     return s:connections
 endfunction
 
@@ -449,6 +452,7 @@ function! ale#lsp#StartProgram(conn_id, executable, command) abort
     endif
 
     if l:started && !l:conn.is_tsserver
+        let l:conn.initialized = 0
         call s:SendInitMessage(l:conn)
     endif
 
diff --git a/autoload/ale/lsp_linter.vim b/autoload/ale/lsp_linter.vim
index e4148ceb..dcd76e8f 100644
--- a/autoload/ale/lsp_linter.vim
+++ b/autoload/ale/lsp_linter.vim
@@ -34,7 +34,11 @@ endfunction
 function! s:HandleLSPDiagnostics(conn_id, response) abort
     let l:linter_name = s:lsp_linter_map[a:conn_id]
     let l:filename = ale#path#FromURI(a:response.params.uri)
-    let l:buffer = bufnr('^' . l:filename . '$')
+    let l:escaped_name = escape(
+    \   fnameescape(l:filename),
+    \   has('win32') ? '^' : '^,}]'
+    \)
+    let l:buffer = bufnr('^' . l:escaped_name . '$')
     let l:info = get(g:ale_buffer_info, l:buffer, {})
 
     if empty(l:info)
@@ -52,7 +56,11 @@ endfunction
 
 function! s:HandleTSServerDiagnostics(response, error_type) abort
     let l:linter_name = 'tsserver'
-    let l:buffer = bufnr('^' . a:response.body.file . '$')
+    let l:escaped_name = escape(
+    \   fnameescape(a:response.body.file),
+    \   has('win32') ? '^' : '^,}]'
+    \)
+    let l:buffer = bufnr('^' . l:escaped_name . '$')
     let l:info = get(g:ale_buffer_info, l:buffer, {})
 
     if empty(l:info)
@@ -227,7 +235,7 @@ function! ale#lsp_linter#OnInit(linter, details, Callback) abort
     let l:command = a:details.command
 
     let l:config = ale#lsp_linter#GetConfig(l:buffer, a:linter)
-    let l:language_id = ale#util#GetFunction(a:linter.language_callback)(l:buffer)
+    let l:language_id = ale#linter#GetLanguage(l:buffer, a:linter)
 
     call ale#lsp#UpdateConfig(l:conn_id, l:buffer, l:config)
 
@@ -265,7 +273,14 @@ function! s:StartLSP(options, address, executable, command) abort
             call ale#lsp#MarkConnectionAsTsserver(l:conn_id)
         endif
 
-        let l:command = ale#command#FormatCommand(l:buffer, a:executable, a:command, 0, v:false)[1]
+        let l:command = ale#command#FormatCommand(
+        \   l:buffer,
+        \   a:executable,
+        \   a:command,
+        \   0,
+        \   v:false,
+        \   [],
+        \)[1]
         let l:command = ale#job#PrepareCommand(l:buffer, l:command)
         let l:ready = ale#lsp#StartProgram(l:conn_id, a:executable, l:command)
     endif
diff --git a/autoload/ale/path.vim b/autoload/ale/path.vim
index 30550503..fed95ccd 100644
--- a/autoload/ale/path.vim
+++ b/autoload/ale/path.vim
@@ -24,6 +24,14 @@ function! ale#path#Simplify(path) abort
     return substitute(simplify(l:win_path), '^\\\+', '\', 'g') " no-custom-checks
 endfunction
 
+" Simplify a path without a Windows drive letter.
+" This function can be used for checking if paths are equal.
+function! ale#path#RemoveDriveLetter(path) abort
+    return has('win32') && a:path[1:2] is# ':\'
+    \   ? ale#path#Simplify(a:path[2:])
+    \   : ale#path#Simplify(a:path)
+endfunction
+
 " Given a buffer and a filename, find the nearest file by searching upwards
 " through the paths relative to the given buffer.
 function! ale#path#FindNearestFile(buffer, filename) abort
@@ -74,15 +82,19 @@ endfunction
 function! ale#path#CdString(directory) abort
     if has('win32')
         return 'cd /d ' . ale#Escape(a:directory) . ' && '
-    else
-        return 'cd ' . ale#Escape(a:directory) . ' && '
     endif
+
+    return 'cd ' . ale#Escape(a:directory) . ' && '
 endfunction
 
 " Output 'cd <buffer_filename_directory> && '
 " This function can be used changing the directory for a linter command.
 function! ale#path#BufferCdString(buffer) abort
-    return ale#path#CdString(fnamemodify(bufname(a:buffer), ':p:h'))
+    if has('win32')
+        return 'cd /d %s:h && '
+    endif
+
+    return 'cd %s:h && '
 endfunction
 
 " Return 1 if a path is an absolute path.
@@ -95,7 +107,7 @@ function! ale#path#IsAbsolute(filename) abort
     return a:filename[:0] is# '/' || a:filename[1:2] is# ':\'
 endfunction
 
-let s:temp_dir = ale#path#Simplify(fnamemodify(ale#util#Tempname(), ':h'))
+let s:temp_dir = ale#path#Simplify(fnamemodify(ale#util#Tempname(), ':h:h'))
 
 " Given a filename, return 1 if the file represents some temporary file
 " created by Vim.
diff --git a/autoload/ale/preview.vim b/autoload/ale/preview.vim
index faf45cb0..8b94aa7a 100644
--- a/autoload/ale/preview.vim
+++ b/autoload/ale/preview.vim
@@ -1,14 +1,22 @@
 " Author: w0rp <devw0rp@gmail.com>
 " Description: Preview windows for showing whatever information in.
 
-if !has_key(s:, 'last_selection_list')
-    let s:last_selection_list = []
+if !has_key(s:, 'last__list')
+    let s:last_list = []
 endif
 
-if !has_key(s:, 'last_selection_open_in')
-    let s:last_selection_open_in = 'current-buffer'
+if !has_key(s:, 'last_options')
+    let s:last_options = {}
 endif
 
+function! ale#preview#SetLastSelection(item_list, options) abort
+    let s:last_list = a:item_list
+    let s:last_options = {
+    \   'open_in': get(a:options, 'open_in', 'current-buffer'),
+    \   'use_relative_paths': get(a:options, 'use_relative_paths', 0),
+    \}
+endfunction
+
 " Open a preview window and show some lines in it.
 " A second argument can be passed as a Dictionary with options. They are...
 "
@@ -81,19 +89,14 @@ function! ale#preview#ShowSelection(item_list, ...) abort
     let b:ale_preview_item_list = a:item_list
     let b:ale_preview_item_open_in = get(l:options, 'open_in', 'current-buffer')
 
-    " Remove the last preview
-    let s:last_selection_list = b:ale_preview_item_list
-    let s:last_selection_open_in = b:ale_preview_item_open_in
+    " Remember preview state, so we can repeat it later.
+    call ale#preview#SetLastSelection(a:item_list, l:options)
 endfunction
 
 function! ale#preview#RepeatSelection() abort
-    if empty(s:last_selection_list)
-        return
+    if !empty(s:last_list)
+        call ale#preview#ShowSelection(s:last_list, s:last_options)
     endif
-
-    call ale#preview#ShowSelection(s:last_selection_list, {
-    \   'open_in': s:last_selection_open_in,
-    \})
 endfunction
 
 function! s:Open(open_in) abort
diff --git a/autoload/ale/test.vim b/autoload/ale/test.vim
index 082d91ff..6fcbf35e 100644
--- a/autoload/ale/test.vim
+++ b/autoload/ale/test.vim
@@ -145,8 +145,8 @@ function! ale#test#WaitForJobs(deadline) abort
     " end, but before handlers are run.
     sleep 10ms
 
-    " We must check the buffer data again to see if new jobs started
-    " for command_chain linters.
+    " We must check the buffer data again to see if new jobs started for
+    " linters with chained commands.
     let l:has_new_jobs = 0
 
     " Check again to see if any jobs are running.
diff --git a/autoload/ale/util.vim b/autoload/ale/util.vim
index bb9c1961..1f396377 100644
--- a/autoload/ale/util.vim
+++ b/autoload/ale/util.vim
@@ -423,7 +423,10 @@ function! ale#util#Writefile(buffer, lines, filename) abort
     \   ? map(copy(a:lines), 'substitute(v:val, ''\r*$'', ''\r'', '''')')
     \   : a:lines
 
-    call writefile(l:corrected_lines, a:filename, 'S') " no-custom-checks
+    " Set binary flag if buffer doesn't have eol and nofixeol to avoid appending newline
+    let l:flags = !getbufvar(a:buffer, '&eol') && exists('+fixeol') && !&fixeol ? 'bS' : 'S'
+
+    call writefile(l:corrected_lines, a:filename, l:flags) " no-custom-checks
 endfunction
 
 if !exists('s:patial_timers')