Allow changing the command used to start clangd (#11)

* Allow changing the command used to start clangd

* Update `custom_command` description

LSP-clangd.sublime-settings

@@ -4,17 +4,26 @@
     /////////////////////////
 
     // The clangd binary to use.
-    // "system": Prefers the system binary found in path
+    // "system": Prefers the system binary below
     // "auto": Prefers the system binary but falls back to GitHub without user intervention
     // "github": Prefers the latest tested release from GitHub
+    // "custom": Use the custom command in the initializationOptions below
     "binary": "system",
-    // The command to start `clangd`, generated internally.
+    // The binary to use when `binary` is set to `system`.
+    "system_binary": "clangd",
+    // Generated internally because clangd is configured via command line arguments.
+    // DO NOT CHANGE THIS, use `system_binary` or `custom_command` instead.
     "command": [],
     // Enable clangd for C/C++ and Objective-C/C++
     "selector": "source.c | source.c++ | source.objc | source.objc++ | source.cuda-c++",
     // Makes the auto-complete not trigger twice when writing a -> or when writing ::
     "auto_complete_selector": "punctuation.accessor | (meta.preprocessor.include string - punctuation.definition.string.end)",
     "initializationOptions": {
+        // A custom command to start clangd. Set `binary` to `custom` to use this command.
+        // The command-line arguments which are generated from the `clang.*` settings are appended to this command.
+        // This can be used for MSYS2's clangd for example.
+        "custom_command": [],
+
         // @see https://clangd.llvm.org/extensions#file-status
         // Enables receiving textDocument/clangd.fileStatus notifications.
         // -- unsupported --
@@ -93,4 +102,4 @@
         // Pretty-print JSON output
         "clangd.pretty": false,
     },
-}
+}

plugin.py

@@ -93,30 +93,45 @@ def storage_subpath(cls) -> str:
         return os.path.join(cls.storage_path(), STORAGE_DIR)
 
     @classmethod
-    def managed_server_binary_path(cls) -> Optional[str]:
+    def managed_clangd_path(cls) -> Optional[str]:
         binary_name = "clangd.exe" if sublime.platform() == "windows" else "clangd"
         path = os.path.join(cls.storage_subpath(), "clangd_{version}/bin/{binary_name}".format(version=VERSION_STRING, binary_name=binary_name))
         if os.path.exists(path):
             return path
         return None
 
+    @classmethod
+    def system_clangd_path(cls) -> Optional[str]:
+        system_binary = get_settings().get("system_binary")
+        # Detect if clangd is installed or the command points to a valid binary.
+        # Fallback, shutil.which has issues on Windows.
+        system_binary_path = shutil.which(system_binary) or system_binary
+        if not os.path.isfile(system_binary_path):
+            return None
+        return system_binary_path
+
     @classmethod
     def clangd_path(cls) -> Optional[str]:
+        """The command to start clangd without any configuration arguments"""
         binary_setting = get_settings().get("binary")
         if binary_setting == "system":
-            return shutil.which("clangd")
+            return cls.system_clangd_path()
         elif binary_setting == "github":
-            return cls.managed_server_binary_path()
+            return cls.managed_clangd_path()
         else:
             # binary_setting == "auto":
-            return shutil.which("clangd") or cls.managed_server_binary_path()
+            return cls.system_clangd_path() or cls.managed_clangd_path()
 
     @classmethod
     def needs_update_or_installation(cls) -> bool:
+        if get_settings().get("binary") == "custom":
+            return False
         return cls.clangd_path() is None
 
     @classmethod
     def install_or_update(cls) -> None:
+        # Binary cannot be set to custom because needs_update_or_installation
+        # returns False in this case
         if get_settings().get("binary") == "system":
             ans = sublime.yes_no_cancel_dialog("clangd was not found in your path. Would you like to auto-install clangd from GitHub?")
             if ans == sublime.DIALOG_YES:
@@ -136,7 +151,7 @@ def install_or_update(cls) -> None:
         download_server(cls.storage_subpath())
 
         # zip does not preserve file mode
-        path = cls.managed_server_binary_path()
+        path = cls.managed_clangd_path()
         if not path:
             # this should never happen
             raise ValueError("installation failed silently")
@@ -152,13 +167,17 @@ def on_pre_start(
         configuration: ClientConfig,
     ) -> Optional[str]:
 
-        clangd_path = cls.clangd_path()
-        if not clangd_path:
-            raise ValueError("clangd is currently not installed.")
+        if get_settings().get("binary") == "custom":
+            clangd_base_command = configuration.init_options.get("custom_command")  # type: List[str]
+        else:
+            clangd_path = cls.clangd_path()
+            if not clangd_path:
+                raise ValueError("clangd is currently not installed.")
+            clangd_base_command = [clangd_path]
 
         # The configuration is persisted
         # reset the command to prevent adding an argument multiple times
-        configuration.command = [clangd_path]
+        configuration.command = clangd_base_command.copy()
 
         for key, value in configuration.init_options.get("clangd").items():
             if not value:

sublime-package.json

@@ -17,17 +17,29 @@
                   "enum": [
                     "system",
                     "auto",
-                    "github"
+                    "github",
+                    "custom"
                   ],
                   "enumDescriptions": [
                     "Prefers the system binary found in path",
                     "Prefers the system binary but falls back to GitHub without user intervention",
                     "Prefers the latest tested release from GitHub",
+                    "Use the custom command in the initializationOptions below",
                   ],
                 },
+                "system_binary": {
+                  "type": "string",
+                  "default": "clangd",
+                  "markdownDescription": "The binary to use when `binary` is set to `system`."
+                },
                 "initializationOptions": {
                   "additionalProperties": false,
                   "properties": {
+                    "custom_command": {
+                      "type": "array",
+                      "default": [],
+                      "markdownDescription": "A custom command to start clangd. Set `binary` to `custom` to use this command. The command-line arguments which are generated from the `clang.*` settings are appended to this command."
+                    },
                     "clangdFileStatus": {
                       "type": "boolean",
                       "description": "Enables receiving textDocument/clangd.fileStatus notifications.",
@@ -195,7 +207,9 @@
                       "default": null,
                       "description": "Sets the PCH storage. Storing PCHs in memory increases memory usages, but may improve performance",
                       "enum": [
-                        null, "disk", "memory"
+                        null,
+                        "disk",
+                        "memory"
                       ]
                     },
                     "clangd.enable-config": {
@@ -209,7 +223,12 @@
                       ],
                       "default": null,
                       "description": "Sets the clangd log level",
-                      "enum": [null, "error", "info", "verbose"]
+                      "enum": [
+                        null,
+                        "error",
+                        "info",
+                        "verbose"
+                      ]
                     },
                     "clangd.path-mappings": {
                       "type": [
@@ -260,4 +279,4 @@
       }
     ]
   }
-}
+}