Teach TBD that in fragile resilient protocol mode the protocol table is visible

Author: aschwaighofer

include/swift/IRGen/TBDGen.h

@@ -47,6 +47,9 @@ struct TBDGenOptions {
   /// Whether LLVM IR Witness Method Elimination is enabled.
   bool WitnessMethodElimination = false;
 
+  /// Whether resilient protocols should be emitted fragile.
+  bool FragileResilientProtocols = false;
+
   /// The install_name to use in the TBD file.
   std::string InstallName;
 
@@ -78,6 +81,7 @@ struct TBDGenOptions {
            lhs.PublicOrPackageSymbolsOnly == rhs.PublicOrPackageSymbolsOnly &&
            lhs.VirtualFunctionElimination == rhs.VirtualFunctionElimination &&
            lhs.WitnessMethodElimination == rhs.WitnessMethodElimination &&
+           lhs.FragileResilientProtocols == rhs.FragileResilientProtocols &&
            lhs.InstallName == rhs.InstallName &&
            lhs.ModuleLinkName == rhs.ModuleLinkName &&
            lhs.CurrentVersion == rhs.CurrentVersion &&
@@ -95,7 +99,7 @@ struct TBDGenOptions {
     return hash_combine(
         opts.HasMultipleIGMs, opts.IsInstallAPI, opts.LinkerDirectivesOnly,
         opts.PublicOrPackageSymbolsOnly, opts.VirtualFunctionElimination,
-        opts.WitnessMethodElimination,
+        opts.WitnessMethodElimination, opts.FragileResilientProtocols,
         opts.InstallName, opts.ModuleLinkName,
         opts.CurrentVersion, opts.CompatibilityVersion,
         opts.ModuleInstallNameMapPath,

include/swift/SIL/SILSymbolVisitor.h

@@ -39,6 +39,9 @@ struct SILSymbolVisitorOptions {
 
   /// Whether LLVM IR Witness Method Elimination is enabled.
   bool WitnessMethodElimination = false;
+
+  /// Whether resilient protocols should be emitted fragile.
+  bool FragileResilientProtocols = false;
 };
 
 /// Context for `SILSymbolVisitor` symbol enumeration.

lib/Frontend/CompilerInvocation.cpp

@@ -2521,6 +2521,8 @@ static bool ParseTBDGenArgs(TBDGenOptions &Opts, ArgList &Args,
 
   Opts.VirtualFunctionElimination = Args.hasArg(OPT_enable_llvm_vfe);
   Opts.WitnessMethodElimination = Args.hasArg(OPT_enable_llvm_wme);
+  Opts.FragileResilientProtocols =
+    Args.hasArg(OPT_enable_fragile_resilient_protocol_witnesses);
 
   if (const Arg *A = Args.getLastArg(OPT_tbd_compatibility_version)) {
     Opts.CompatibilityVersion = A->getValue();

lib/IRGen/TBDGen.cpp

@@ -511,6 +511,7 @@ void TBDGenVisitor::visit(const TBDGenDescriptor &desc) {
   opts.PublicOrPackageSymbolsOnly = Opts.PublicOrPackageSymbolsOnly;
   opts.WitnessMethodElimination = Opts.WitnessMethodElimination;
   opts.VirtualFunctionElimination = Opts.VirtualFunctionElimination;
+  opts.FragileResilientProtocols = Opts.FragileResilientProtocols;
 
   auto silVisitorCtx = SILSymbolVisitorContext(SwiftModule, opts);
   auto visitorCtx = IRSymbolVisitorContext{UniversalLinkInfo, silVisitorCtx};

lib/SIL/IR/SILSymbolVisitor.cpp

@@ -269,7 +269,8 @@ class SILSymbolVisitorImpl : public ASTVisitor<SILSymbolVisitorImpl> {
       // We cannot emit the witness table symbol if the protocol is imported
       // from another module and it's resilient, because initialization of that
       // protocol is necessary in this case
-      if (!rootConformance->getProtocol()->isResilient(
+      if (Ctx.getOpts().FragileResilientProtocols ||
+          !rootConformance->getProtocol()->isResilient(
               IDC->getAsGenericContext()->getParentModule(),
               ResilienceExpansion::Maximal))
         Visitor.addProtocolWitnessTable(rootConformance);

stdlib/cmake/modules/SwiftSource.cmake

@@ -627,7 +627,6 @@ function(_compile_swift_files
   endif()
 
   if (SWIFT_STDLIB_USE_FRAGILE_RESILIENT_PROTOCOL_WITNESS_TABLES)
-    list(APPEND swift_flags "-Xfrontend" "-validate-tbd-against-ir=none")
     list(APPEND swift_flags "-Xfrontend" "-enable-fragile-relative-protocol-tables")
     list(APPEND swift_flags "-enable-library-evolution")
   endif()

test/lit.cfg

@@ -1187,7 +1187,7 @@ if run_vendor == 'apple':
             swift_execution_tests_extra_flags += ' -Xfrontend -enable-relative-protocol-witness-tables -Xfrontend -swift-async-frame-pointer=never'
 
         if config.swift_stdlib_use_use_fragile_resilient_protocol_witness_tables:
-            swift_execution_tests_extra_flags += ' -Xfrontend -validate-tbd-against-ir=none -Xfrontend -enable-fragile-relative-protocol-tables'
+            swift_execution_tests_extra_flags += ' -Xfrontend -enable-fragile-relative-protocol-tables'
 
         # Build a resource dir for freestanding tests.
         new_resource_dir = os.path.join(config.test_exec_root, "resource_dir")