Fix cl.exe not appearing in the compiler list. (#6884)

Author: sean-mcmanus

Extension/src/LanguageServer/cppBuildTaskProvider.ts

@@ -114,15 +114,17 @@ export class CppBuildTaskProvider implements TaskProvider {
             }
         }
 
+        const isCompilerValid: boolean = userCompilerPath ? await util.checkFileExists(userCompilerPath) : false;
+
         // Get known compiler paths. Do not include the known compiler path that is the same as user compiler path.
         // Filter them based on the file type to get a reduced list appropriate for the active file.
         const knownCompilerPathsSet: Set<string> = new Set();
         let knownCompilers: configs.KnownCompiler[] | undefined = await activeClient.getKnownCompilers();
         if (knownCompilers) {
             knownCompilers = knownCompilers.filter(info =>
                 ((fileIsCpp && !info.isC) || (fileIsC && info.isC)) &&
-                userCompilerPathAndArgs &&
-                (path.basename(info.path) !== userCompilerPathAndArgs.compilerName) &&
+                (!isCompilerValid || (userCompilerPathAndArgs &&
+                (path.basename(info.path) !== userCompilerPathAndArgs.compilerName))) &&
                 (!isWindows || !info.path.startsWith("/"))); // TODO: Add WSL compiler support.
             knownCompilers.map<void>(info => {
                 knownCompilerPathsSet.add(info.path);
@@ -143,11 +145,8 @@ export class CppBuildTaskProvider implements TaskProvider {
             result = knownCompilerPaths.map<Task>(compilerPath => this.getTask(compilerPath, appendSourceToName, undefined));
         }
         // Task for valid user compiler path setting
-        if (userCompilerPath) {
-            const isCompilerValid: boolean = await util.checkFileExists(userCompilerPath);
-            if (isCompilerValid) {
-                result.push(this.getTask(userCompilerPath, appendSourceToName, userCompilerPathAndArgs?.additionalArgs));
-            }
+        if (isCompilerValid && userCompilerPath) {
+            result.push(this.getTask(userCompilerPath, appendSourceToName, userCompilerPathAndArgs?.additionalArgs));
         }
         return result;
     }