Improve workspace handelling

- Use `cargo locate-project --workspace` to find workspace manifiest
- Add `cargo all` which checks all workspaces and all targets
- Fix issue with paths relative to the cargo manifest root

Author: QuantumEntangledAndy

lib/init.coffee

@@ -26,13 +26,15 @@ module.exports =
         'test all'
         'rustc'
         'clippy'
+        'clippy all'
       ]
       description: """`cargo` command to run.<ul>
       <li>Use **build** to simply compile the code.</li>
       <li>Use **check** for fast linting (does not build the project).</li>
       <li>Use **check all** for fast linting of all packages in the project.</li>
       <li>Use **check tests** to also include \`#[cfg(test)]\` code in linting.</li>
       <li>Use **clippy** to increase amount of available lints (you need to install \`clippy\`).</li>
+      <li>Use **clippy all** to increase amount of available lints (you need to install \`clippy\`) for all packages in the project.</li>
       <li>Use **test** to run tests (note that once the tests are built, lints stop showing).</li>
       <li>Use **test all** run tests for all packages in the project.</li>
       <li>Use **rustc** for linting with Rust pre-1.23.</li>

lib/linter-rust.coffee

@@ -32,6 +32,7 @@ class LinterRust
     @subscriptions.add atom.config.observe 'linter-rust.cargoCommand',
     (cargoCommand) =>
       @cargoCommand = cargoCommand
+      @useWorkspaceManifest = cargoCommand.endsWith('all')
 
     @subscriptions.add atom.config.observe 'linter-rust.rustcBuildTest',
     (rustcBuildTest) =>
@@ -75,6 +76,8 @@ class LinterRust
       cmdPath = if cmd[0]? then path.dirname cmd[0] else __dirname
       args = cmd.slice 1
       env.PATH = cmdPath + path.delimiter + env.PATH
+      cargoManifestFile = @locateCargo curDir
+      cargoManifestDir = path.dirname cargoManifestFile
 
       # we set flags only for intermediate json support
       if errorMode == errorModes.FLAGS_JSON_CARGO
@@ -116,7 +119,8 @@ class LinterRust
             # correct file paths
             messages.forEach (message) ->
               if !(path.isAbsolute message.location.file)
-                message.location.file = path.join curDir, message.location.file
+                message.location.file = path.join curDir, message.location.file if fs.existsSync path.join curDir, message.location.file
+                message.location.file = path.join cargoManifestDir, message.location.file if fs.existsSync path.join cargoManifestDir, message.location.file
             messages
           else
             # whoops, we're in trouble -- let's output as much as we can
@@ -199,8 +203,29 @@ class LinterRust
   locateCargo: (curDir) =>
     root_dir = if /^win/.test process.platform then /^.:\\$/ else /^\/$/
     directory = path.resolve curDir
+    manifest_name = @cargoManifestFilename
+
     loop
-      return path.join directory, @cargoManifestFilename if fs.existsSync path.join directory, @cargoManifestFilename
+      if fs.existsSync path.join directory, manifest_name
+        crate_level_manifest = path.join directory , manifest_name
+
+        if @useWorkspaceManifest
+          execOpts =
+            env: JSON.parse JSON.stringify process.env
+            cwd: curDir
+            stream: 'both'
+
+          atom_linter.exec('cargo', ['locate-project', '--workspace', '--manifest-path=' + crate_level_manifest], execOpts)
+            .then (result) =>
+              {stdout, stderr, exitCode} = result
+              json = JSON.parse stdout
+              return  json.root
+            .catch (error) ->
+              return crate_level_manifest
+        else
+          return crate_level_manifest
+
+      return path.join directory , manifest_name if fs.existsSync path.join directory, manifest_name
       break if root_dir.test directory
       directory = path.resolve path.join(directory, '..')
     return false

lib/mode.coffee

@@ -165,7 +165,7 @@ buildCargoArguments = (linter, cargoManifestPath) ->
               .catch ->
                 result: false
       usingMultitoolForClippy.then (canUseMultirust) ->
-        if cargoCommand == 'clippy' and canUseMultirust.result
+        if (cargoCommand == 'clippy' or cargoCommand == 'clippy all') and canUseMultirust.result
           [canUseMultirust.tool, 'run', 'nightly', 'cargo']
         else
           [cargoPath]
@@ -181,6 +181,7 @@ buildCargoArguments = (linter, cargoManifestPath) ->
     when 'test all' then ['test', '--no-run', '--all']
     when 'rustc' then ['rustc', '--color', 'never']
     when 'clippy' then ['clippy']
+    when 'clippy all' then ['clippy', '--workspace', '--all-targets']
     else ['build']
 
   compilationFeatures = linter.compilationFeatures(true)