Merge remote-tracking branch 'origin/master' into master-next

Author: swift-ci

lib/Frontend/ParseableInterfaceModuleLoader.cpp

@@ -839,6 +839,12 @@ class ParseableInterfaceModuleLoaderImpl {
     return scratch.str();
   }
 
+  bool isInResourceDir(StringRef path) {
+    StringRef resourceDir = ctx.SearchPathOpts.RuntimeLibraryPath;
+    if (resourceDir.empty()) return false;
+    return path.startswith(resourceDir);
+  }
+
   /// Finds the most appropriate .swiftmodule, whose dependencies are up to
   /// date, that we can load for the provided .swiftinterface file.
   llvm::ErrorOr<DiscoveredModule> discoverUpToDateModuleForInterface(
@@ -944,6 +950,21 @@ class ParseableInterfaceModuleLoaderImpl {
                                 << modulePath
                                 << "; deferring to serialized module loader\n");
         return std::make_error_code(std::errc::not_supported);
+      } else if (isInResourceDir(modulePath) &&
+                 loadMode == ModuleLoadingMode::PreferSerialized) {
+        // Special-case here: If we're loading a .swiftmodule from the resource
+        // dir adjacent to the compiler, defer to the serialized loader instead
+        // of falling back. This is mainly to support development of Swift,
+        // where one might change the module format version but forget to
+        // recompile the standard library. If that happens, don't fall back
+        // and silently recompile the standard library -- instead, error like
+        // we used to.
+        LLVM_DEBUG(llvm::dbgs() << "Found out-of-date module in the "
+                                   "resource-dir at "
+                                << modulePath
+                                << "; deferring to serialized module loader "
+                                   "to diagnose\n");
+        return std::make_error_code(std::errc::not_supported);
       } else {
         LLVM_DEBUG(llvm::dbgs() << "Found out-of-date module at "
                                 << modulePath << "\n");

test/ParseableInterface/inherited-defaults-execution.swift

@@ -31,7 +31,7 @@
 //
 // RUN: %target-build-swift -I%t -L%t -lInherited -o %t/main %target-rpath(%t) %t/main.swift -swift-version 5
 // RUN: %target-codesign %t/main %t/%target-library-name(Inherited)
-// RUN: %target-run %t/main | %FileCheck --check-prefix=OUTPUT %s
+// RUN: %target-run %t/main %t/%target-library-name(Inherited) | %FileCheck --check-prefix=OUTPUT %s
 //
 // OUTPUT: 45
 // OUTPUT-NEXT: 98