expose "-assume-filename"

Author: xaverh

package.json

@@ -174,6 +174,11 @@
                     "type": "string",
                     "default": "",
                     "description": "clang-format fallback style for Protobuf, left empty to use clang-format.fallbackStyle"
+                },
+                "clang-format.assumeFilename" : {
+                    "type": "string",
+                    "default": "",
+                    "description": "When reading from stdin, clang-format assumes this                               filename to look for a style config file (with -style=file) and to determine the language."
                 }
             }
         }

src/extension.ts

@@ -9,7 +9,8 @@ export class ClangDocumentFormattingEditProvider implements vscode.DocumentForma
     private defaultConfigure = {
         executable: 'clang-format',
         style: 'file',
-        fallbackStyle: 'none'
+        fallbackStyle: 'none',
+        assumeFilename: ''
     };
 
     public provideDocumentFormattingEdits(document: vscode.TextDocument, options: vscode.FormattingOptions, token: vscode.CancellationToken): Thenable<vscode.TextEdit[]> {
@@ -156,6 +157,14 @@ export class ClangDocumentFormattingEditProvider implements vscode.DocumentForma
         return this.defaultConfigure.style;
     }
 
+    private getAssumedFilename(document: vscode.TextDocument) {
+                let assumedFilename = vscode.workspace.getConfiguration('clang-format').get<string>('assumeFilename');
+        if (assumedFilename === "") {
+            return document.fileName;
+        }
+        return assumedFilename;
+    }
+
     private doFormatDocument(document: vscode.TextDocument, range: vscode.Range, options: vscode.FormattingOptions, token: vscode.CancellationToken): Thenable<vscode.TextEdit[]> {
         return new Promise((resolve, reject) => {
             var filename = document.fileName;
@@ -188,7 +197,7 @@ export class ClangDocumentFormattingEditProvider implements vscode.DocumentForma
                 '-output-replacements-xml',
                 `-style=${this.getStyle(document)}`,
                 `-fallback-style=${this.getFallbackStyle(document)}`,
-                `-assume-filename=${document.fileName}`,
+                `-assume-filename=${this.getAssumedFilename(document)}`,
             ];
 
             if (range) {