Exit early args are invalid

Add batch-code-compelte test

Author: elsh

include/swift/Frontend/Frontend.h

@@ -316,7 +316,8 @@ class CompilerInvocation {
   ///             of the binary on disk, /path/to/Bar.swiftmodule(interface), under the hood.
   /// \param diags Used to print diagnostics in case validation of the string args fails.
   ///        See \c ModuleAliasesConverter::computeModuleAliases on validation details.
-  void setModuleAliasMap(std::vector<std::string> args, DiagnosticEngine &diags);
+  /// \return Whether setting module alias map succeeded; false if args validation fails.
+  bool setModuleAliasMap(std::vector<std::string> args, DiagnosticEngine &diags);
 
   std::string getOutputFilename() const {
     return FrontendOpts.InputsAndOutputs.getSingleOutputFilename();

lib/Frontend/CompilerInvocation.cpp

@@ -262,9 +262,9 @@ void CompilerInvocation::setSDKPath(const std::string &Path) {
   updateRuntimeLibraryPaths(SearchPathOpts, LangOpts.Target);
 }
 
-void CompilerInvocation::setModuleAliasMap(std::vector<std::string> args,
+bool CompilerInvocation::setModuleAliasMap(std::vector<std::string> args,
                                            DiagnosticEngine &diags) {
-  ModuleAliasesConverter::computeModuleAliases(args, FrontendOpts, diags);
+  return ModuleAliasesConverter::computeModuleAliases(args, FrontendOpts, diags);
 }
 
 static bool ParseFrontendArgs(

test/IDE/module-aliasing-repl-code-complete.swift

@@ -19,7 +19,7 @@
 
 // CHECK: Begin completions
 // CHECK-NOT: AppleLogging
-// CHECK-DAG: XLogging
+// CHECK: XLogging
 // CHECK: End completions
 
 // BEGIN FileLogging.swift

tools/swift-ide-test/swift-ide-test.cpp

@@ -4242,7 +4242,10 @@ int main(int argc, char *argv[]) {
     SourceManager SM;
     DiagnosticEngine Diags(SM);
     Diags.addConsumer(PDC);
-    InitInvok.setModuleAliasMap(options::ModuleAliases, Diags);
+    if (!InitInvok.setModuleAliasMap(options::ModuleAliases, Diags)) {
+      llvm::errs() << "invalid module alias arguments\n";
+      return 1;
+    }
   }
 
   // Process the clang arguments last and allow them to override previously