[lldb] Support diagnostic options in Swift REPL

Honor some previously ignored diagnostic options like
'-debug-diagnostic-names' and '-locale' by applying them to the
diagnostic engine in the SwiftASTContext.

https://bugs.swift.org/browse/SR-14845

Author: poya

lldb/source/Plugins/TypeSystem/Swift/SwiftASTContext.cpp

@@ -38,6 +38,7 @@
 #include "swift/AST/Type.h"
 #include "swift/AST/Types.h"
 #include "swift/ASTSectionImporter/ASTSectionImporter.h"
+#include "swift/Basic/DiagnosticOptions.h"
 #include "swift/Basic/Dwarf.h"
 #include "swift/Basic/LangOptions.h"
 #include "swift/Basic/Located.h"
@@ -1541,6 +1542,20 @@ void SwiftASTContext::ApplyWorkingDir(
   clang_argument.append(joined_path.begin(), joined_path.end());
 }
 
+void SwiftASTContext::ApplyDiagnosticOptions() {
+  const auto &opts = GetCompilerInvocation().getDiagnosticOptions();
+  if (opts.PrintDiagnosticNames)
+    GetDiagnosticEngine().setPrintDiagnosticNames(true);
+
+  if (!opts.DiagnosticDocumentationPath.empty())
+    GetDiagnosticEngine().setDiagnosticDocumentationPath(
+        opts.DiagnosticDocumentationPath);
+
+  if (!opts.LocalizationCode.empty() && !opts.LocalizationPath.empty())
+    GetDiagnosticEngine().setLocalization(opts.LocalizationCode,
+                                          opts.LocalizationPath);
+}
+
 void SwiftASTContext::RemapClangImporterOptions(
     const PathMappingList &path_map) {
   auto &options = GetClangImporterOptions();
@@ -2324,6 +2339,8 @@ lldb::TypeSystemSP SwiftASTContext::CreateInstance(lldb::LanguageType language,
                                   swift_ast_sp->GetDiagnosticEngine());
   }
 
+  swift_ast_sp->ApplyDiagnosticOptions();
+
   // Apply source path remappings found in the target settings.
   swift_ast_sp->RemapClangImporterOptions(target.GetSourcePathMap());
 

lldb/source/Plugins/TypeSystem/Swift/SwiftASTContext.h

@@ -921,6 +921,8 @@ class SwiftASTContext : public TypeSystemSwift {
 
   friend class CompilerType;
 
+  void ApplyDiagnosticOptions();
+
   /// Apply a PathMappingList dictionary on all search paths in the
   /// ClangImporterOptions.
   void RemapClangImporterOptions(const PathMappingList &path_map);

lldb/test/Shell/SwiftREPL/DiagnosticOptions.test

@@ -0,0 +1,20 @@
+// Test diagnostic options in REPL
+// REQUIRES: swift
+
+// RUN: %lldb --repl="-debug-diagnostic-names" < %s 2>&1 \
+// RUN: | FileCheck %s --check-prefix=DIAGNOSTIC
+
+// RUN: split-file %s %t.dir
+// RUN: %lldb --repl="-localization-path %t.dir -locale fr" < %s 2>&1 \
+// RUN: | FileCheck %s --check-prefix=LOCALIZED
+
+
+_ = "An unterminated string
+// DIAGNOSTIC: error: unterminated string literal [lex_unterminated_string]{{$}}
+// LOCALIZED: error: chaîne non terminée littérale{{$}}
+:quit
+
+
+//--- fr.yaml
+- id: "lex_unterminated_string"
+  msg: "chaîne non terminée littérale"