Close #2556 - Support filename mapping

ALE now supports mapping files between different systems for running
linters and fixers with Docker, in virtual machines, in servers, etc.

autoload/ale.vim

@@ -266,3 +266,23 @@ function! ale#GetLocItemMessage(item, format_string) abort
 
     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

autoload/ale/command.vim

@@ -133,11 +133,30 @@ 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.
+function! s:FormatFilename(filename, mappings) abort
+    let l:filename = a:filename
+
+    if !empty(a:mappings)
+        let l:filename = ale#filename_mapping#Map(l:filename, a:mappings)
+    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,
+\   filename_mappings,
+\) abort
     let l:temporary_file = ''
     let l:command = a:command
 
@@ -154,14 +173,14 @@ 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, '%s', '\=s:FormatFilename(l:filename, a:filename_mappings)', '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, '%t', '\=s:FormatFilename(l:temporary_file, a:filename_mappings)', 'g')
     endif
 
     " Finish formatting so %% becomes %.
@@ -265,6 +284,7 @@ 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 = {

autoload/ale/engine.vim

@@ -256,6 +256,13 @@ 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 = []
 
@@ -296,13 +303,19 @@ 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')
@@ -415,6 +428,7 @@ function! s:RunJob(command, options) abort
     \   'executable': l:executable,
     \   'read_buffer': l:read_buffer,
     \   'log_output': 1,
+    \   'filename_mappings': ale#GetFilenameMappings(l:buffer, l:linter.name),
     \})
 
     " Only proceed if the job is being run.

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

autoload/ale/fix.vim

@@ -1,4 +1,8 @@
+" Author: w0rp <devw0rp@gmail.com>
+" Description: Functions for fixing code with programs, or other means.
+
 call ale#Set('fix_on_save_ignore', {})
+call ale#Set('filename_mappings', {})
 
 " Apply fixes queued up for buffers which may be hidden.
 " Vim doesn't let you modify hidden buffers.
@@ -110,7 +114,6 @@ function! s:HandleExit(job_info, buffer, job_output, data) abort
     call s:RunFixer({
     \   'buffer': a:buffer,
     \   'input': l:input,
-    \   'output': l:output,
     \   'callback_list': a:job_info.callback_list,
     \   'callback_index': a:job_info.callback_index + 1,
     \})
@@ -125,6 +128,7 @@ 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
@@ -150,7 +154,6 @@ function! s:RunJob(result, options) abort
         \   'input': l:input,
         \   'callback_index': a:options.callback_index,
         \   'callback_list': a:options.callback_list,
-        \   'output': [],
         \})
 
         return
@@ -177,6 +180,7 @@ 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)
@@ -200,32 +204,22 @@ 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
 
@@ -293,16 +287,24 @@ 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.

autoload/ale/fix/registry.vim

@@ -160,11 +160,11 @@ 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'],

autoload/ale/lsp_linter.vim

@@ -265,7 +265,14 @@ 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

autoload/ale/path.vim

@@ -95,7 +95,7 @@ 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.