Frontend: add a frontend argument to pass down block list config file path

include/swift/Basic/LangOptions.h

@@ -556,6 +556,9 @@ namespace swift {
     /// The model of concurrency to be used.
     ConcurrencyModel ActiveConcurrencyModel = ConcurrencyModel::Standard;
 
+    /// All block list configuration files to be honored in this compilation.
+    std::vector<std::string> BlocklistConfigFilePath;
+
     bool isConcurrencyModelTaskToThread() const {
       return ActiveConcurrencyModel == ConcurrencyModel::TaskToThread;
     }

include/swift/Option/FrontendOptions.td

@@ -240,6 +240,9 @@ def Raccess_note : Separate<["-"], "Raccess-note">,
 def Raccess_note_EQ : Joined<["-"], "Raccess-note=">,
     Alias<Raccess_note>;
 
+def block_list_file
+  : Separate<["-"], "blocklist-file">, MetaVarName<"<path>">,
+    HelpText<"The path to a blocklist configuration file">;
 } // end let Flags = [FrontendOption, NoDriverOption]
 
 def debug_crash_Group : OptionGroup<"<automatic crashing options>">;

lib/AST/ASTContext.cpp

@@ -707,6 +707,10 @@ ASTContext::ASTContext(
   registerNameLookupRequestFunctions(evaluator);
 
   createModuleToExecutablePluginMap();
+  // Insert all block list config paths.
+  for (auto path: langOpts.BlocklistConfigFilePath) {
+    blockListConfig.addConfigureFilePath(path);
+  }
 }
 
 ASTContext::~ASTContext() {

lib/Frontend/CompilerInvocation.cpp

@@ -1164,6 +1164,9 @@ static bool ParseLangArgs(LangOptions &Opts, ArgList &Args,
 
   Opts.DumpTypeWitnessSystems = Args.hasArg(OPT_dump_type_witness_systems);
 
+  for (auto A : Args.getAllArgValues(options::OPT_block_list_file)) {
+    Opts.BlocklistConfigFilePath.push_back(A);
+  }
   if (const Arg *A = Args.getLastArg(options::OPT_concurrency_model)) {
     Opts.ActiveConcurrencyModel =
         llvm::StringSwitch<ConcurrencyModel>(A->getValue())