Add a setting for precise compiler invocations.

Author: adrian-prantl

lldb/include/lldb/Core/ModuleList.h

@@ -66,6 +66,7 @@ class ModuleListProperties : public Properties {
   SwiftModuleLoadingMode GetSwiftModuleLoadingMode() const;
   bool SetSwiftModuleLoadingMode(SwiftModuleLoadingMode);
 
+  bool GetUseSwiftPreciseCompilerInvocation() const;
   bool GetEnableSwiftMetadataCache() const;
   uint64_t GetSwiftMetadataCacheMaxByteSize();
   uint64_t GetSwiftMetadataCacheExpirationDays();

lldb/source/Core/CoreProperties.td

@@ -26,6 +26,9 @@ let Definition = "modulelist" in {
   def SwiftValidateTypeSystem: Property<"swift-validate-typesystem", "Boolean">,
     DefaultFalse,
     Desc<"Validate all Swift typesystem queries. Used for testing an asserts-enabled LLDB only.">;
+  def UseSwiftPreciseCompilerInvocation: Property<"swift-precise-compiler-invocation", "Boolean">,
+    DefaultFalse,
+    Desc<"In the Swift expression evaluator, create many Swift compiler instances with the precise invocation for the current context, instead of a single compiler instance that merges all flags from the entire project.">;
   def SwiftModuleLoadingMode: Property<"swift-module-loading-mode", "Enum">,
     DefaultEnumValue<"eSwiftModuleLoadingModePreferSerialized">,
     EnumValues<"OptionEnumValues(g_swift_module_loading_mode_enums)">,

lldb/source/Core/ModuleList.cpp

@@ -183,6 +183,12 @@ bool ModuleListProperties::GetSwiftValidateTypeSystem() const {
       idx, g_modulelist_properties[idx].default_uint_value != 0);
 }
 
+bool ModuleListProperties::GetUseSwiftPreciseCompilerInvocation() const {
+  const uint32_t idx = ePropertyUseSwiftPreciseCompilerInvocation;
+  return GetPropertyAtIndexAs<bool>(
+      idx, g_modulelist_properties[idx].default_uint_value != 0);
+}
+
 bool ModuleListProperties::SetUseSwiftTypeRefTypeSystem(bool new_value) {
   const uint32_t idx = ePropertyUseSwiftTypeRefTypeSystem;
   return SetPropertyAtIndex(idx, new_value);