Merge pull request swiftlang#68672 from artemcm/NoInheritSearchPathsInSwift6

Do not inherit search paths from loaded binary Swift module dependencies in Swift 6

Author: swift-ci

lib/Serialization/ModuleFile.cpp

@@ -271,8 +271,10 @@ Status ModuleFile::associateWithFileContext(FileUnit *file, SourceLoc diagLoc,
   }
 
   StringRef SDKPath = ctx.SearchPathOpts.getSDKPath();
-  if (SDKPath.empty() ||
-      !Core->ModuleInputBuffer->getBufferIdentifier().startswith(SDKPath)) {
+  // In Swift 6 mode, we do not inherit search paths from loaded non-SDK modules.
+  if (!ctx.LangOpts.isSwiftVersionAtLeast(6) &&
+      (SDKPath.empty() ||
+       !Core->ModuleInputBuffer->getBufferIdentifier().startswith(SDKPath))) {
     for (const auto &searchPath : Core->SearchPaths) {
       ctx.addSearchPath(
         ctx.SearchPathOpts.SearchPathRemapper.remapPath(searchPath.Path),

test/Serialization/search-paths-relative.swift

@@ -1,3 +1,4 @@
+// REQUIRES: asserts
 // RUN: %empty-directory(%t)
 // RUN: %empty-directory(%t/secret)
 // RUN: %target-swift-frontend -emit-module -o %t/secret %S/Inputs/struct_with_operators.swift
@@ -7,6 +8,11 @@
 // RUN: cd %t/secret && %target-swiftc_driver -emit-module -o %t/has_xref.swiftmodule -I . -F ../Frameworks -parse-as-library %S/Inputs/has_xref.swift %S/../Inputs/empty.swift -Xfrontend -serialize-debugging-options -Xcc -ivfsoverlay -Xcc %S/../Inputs/unextended-module-overlay.yaml -Xcc -DDUMMY
 // RUN: %target-swift-frontend %s -typecheck -I %t
 
+// Ensure that in Swift 6 mode we do not read out search paths, thus are no longer able to
+// locate transitive dependencies with them
+// RUN: not %target-swift-frontend %s -typecheck -I %t -swift-version 6 &> %t/swift_6_output.txt
+// RUN: %FileCheck -check-prefix=SWIFT6 %s < %t/swift_6_output.txt
+
 // Check the actual serialized search paths.
 // RUN: llvm-bcanalyzer -dump %t/has_xref.swiftmodule > %t/has_xref.swiftmodule.txt
 // RUN: %FileCheck %s < %t/has_xref.swiftmodule.txt
@@ -31,3 +37,5 @@ numeric(42)
 // NEGATIVE-NOT: '../Frameworks'
 // This should be filtered out.
 // NEGATIVE-NOT: -ivfsoverlay{{.*}}unextended-module-overlay.yaml
+
+// SWIFT6: error: missing required modules: 'has_alias', 'struct_with_operators'

test/Serialization/search-paths-sdk.swift

@@ -1,4 +1,5 @@
 // REQUIRES: VENDOR=apple
+// REQUIRES: asserts
 // RUN: %empty-directory(%t)
 // RUN: %empty-directory(%t/mock-sdk/usr/lib/swift/SystemLibrary.swiftmodule)
 // RUN: %empty-directory(%t/secret)
@@ -9,6 +10,9 @@
 // We pick up search paths from normal imports...
 // RUN: %target-swift-frontend -typecheck %s -I %t/mock-sdk/usr/lib/swift/
 
+// We do not pick up search paths from any imports in Swift 6 mode
+// RUN: %target-swift-frontend -typecheck %s -I %t/mock-sdk/usr/lib/swift/ -verify -show-diagnostics-after-fatal -swift-version 6
+
 // ...but not from content in the SDK.
 // RUN: %target-swift-frontend -typecheck %s -sdk %t/mock-sdk -verify -show-diagnostics-after-fatal