Guard with env var SWIFT_ENABLE_PACKAGE_INTERFACE_LOAD

Update tests and formatting

Author: elsh

lib/Frontend/CompilerInvocation.cpp

@@ -633,9 +633,9 @@ static bool ParseLangArgs(LangOptions &Opts, ArgList &Args,
     Opts.EnableExperimentalStringProcessing = true;
   }
 
-  if (Args.hasArg(OPT_experimental_package_interface_load)) {
-    Opts.EnablePackageInterfaceLoad = true;
-  }
+  // Either the env var and the flag has to be set to enable package interface load
+  Opts.EnablePackageInterfaceLoad = Args.hasArg(OPT_experimental_package_interface_load) ||
+                                    ::getenv("SWIFT_ENABLE_PACKAGE_INTERFACE_LOAD");
 
   // Experimental string processing.
   if (auto A = Args.getLastArg(OPT_enable_experimental_string_processing,

lib/Serialization/SerializedModuleLoader.cpp

@@ -596,8 +596,9 @@ std::string SerializedModuleBaseName::getName(file_types::ID fileTy) const {
   return std::string(result.str());
 }
 
-llvm::Optional<std::string> SerializedModuleBaseName::getPackageInterfacePathIfInSamePackage(llvm::vfs::FileSystem &fs, ASTContext &ctx) const {
-
+llvm::Optional<std::string>
+SerializedModuleBaseName::getPackageInterfacePathIfInSamePackage(llvm::vfs::FileSystem &fs,
+                                                                 ASTContext &ctx) const {
   if (!ctx.LangOpts.EnablePackageInterfaceLoad)
     return {};
 

test/ModuleInterface/package_interface.swift

@@ -21,25 +21,33 @@
 // RUN: %target-swift-frontend -typecheck %t/Client.swift -I %t \
 // RUN:   -package-name barpkg \
 // RUN:   -experimental-package-interface-load \
-// RUN:   -Rmodule-loading 2> %t/load-pkg-enabled.output
-// RUN: %FileCheck -check-prefix=CHECK-LOAD-PKG-ENABLED %s < %t/load-pkg-enabled.output
-// CHECK-LOAD-PKG-ENABLED: loaded module 'Bar'; source: '{{.*}}/Bar.package.swiftinterface', loaded: '{{.*}}/Bar-{{.*}}.swiftmodule'
+// RUN:   -Rmodule-loading 2> %t/load-pkg-flag.output
+// RUN: %FileCheck -check-prefix=CHECK-LOAD-PKG-ENABLED %s < %t/load-pkg-flag.output
 
-/// Client should not load a package interface module without -experimental-package-interface-load
+/// Client should load a package interface module if enabled with env var `SWIFT_ENABLE_PACKAGE_INTERFACE_LOAD`
+// RUN: env SWIFT_ENABLE_PACKAGE_INTERFACE_LOAD=true \
+// RUN: %target-swift-frontend -typecheck %t/Client.swift -I %t \
+// RUN:   -package-name barpkg \
+// RUN:   -Rmodule-loading 2> %t/load-pkg-env-var.output
+// RUN: %FileCheck -check-prefix=CHECK-LOAD-PKG-ENABLED %s < %t/load-pkg-env-var.output
+
+// CHECK-LOAD-PKG-ENABLED: loaded module 'Bar'; source: '{{.*}}Bar.package.swiftinterface', loaded: '{{.*}}Bar-{{.*}}.swiftmodule'
+
+/// Client should not load a package interface module without the flag or the env var
 // RUN: not %target-swift-frontend -typecheck %t/Client.swift -I %t \
 // RUN:   -package-name barpkg \
 // RUN:   -Rmodule-loading 2> %t/load-pkg-off.output
 // RUN: %FileCheck -check-prefix=CHECK-LOAD-PKG-OFF %s < %t/load-pkg-off.output
-// CHECK-LOAD-PKG-OFF: loaded module 'Bar'; source: '{{.*}}/Bar.private.swiftinterface', loaded: '{{.*}}/Bar-{{.*}}.swiftmodule'
-// CHECK-LOAD-PKG-OFF: error: module 'Bar' is in package 'barpkg' but was built from a non-package interface; modules of the same package can only be loaded if built from source or package interface: {{.*}}/Bar.private.swiftinterface
+// CHECK-LOAD-PKG-OFF: loaded module 'Bar'; source: '{{.*}}Bar.private.swiftinterface', loaded: '{{.*}}Bar-{{.*}}.swiftmodule'
+// CHECK-LOAD-PKG-OFF: error: module 'Bar' is in package 'barpkg' but was built from a non-package interface; modules of the same package can only be loaded if built from source or package interface: {{.*}}Bar.private.swiftinterface
 
 /// Client loads a private interface since the package-name is different from the loaded module's.
 // RUN: %target-swift-frontend -typecheck %t/Client.swift -I %t \
 // RUN:   -package-name foopkg \
 // RUN:   -experimental-package-interface-load \
 // RUN:   -Rmodule-loading 2> %t/load-diff-pkg.output
 // RUN: %FileCheck -check-prefix=CHECK-LOAD-DIFF-PKG %s < %t/load-diff-pkg.output
-// CHECK-LOAD-DIFF-PKG: loaded module 'Bar'; source: '{{.*}}/Bar.private.swiftinterface', loaded: '{{.*}}/Bar-{{.*}}.swiftmodule'
+// CHECK-LOAD-DIFF-PKG: loaded module 'Bar'; source: '{{.*}}Bar.private.swiftinterface', loaded: '{{.*}}Bar-{{.*}}.swiftmodule'
 
 // RUN: rm -rf %t/*.swiftmodule
 // RUN: rm -rf %t/Bar.package.swiftinterface
@@ -50,8 +58,8 @@
 // RUN:   -experimental-package-interface-load \
 // RUN:   -Rmodule-loading 2> %t/load-priv.output
 // RUN: %FileCheck -check-prefix=CHECK-LOAD-PRIV %s < %t/load-priv.output
-// CHECK-LOAD-PRIV: loaded module 'Bar'; source: '{{.*}}/Bar.private.swiftinterface', loaded: '{{.*}}/Bar-{{.*}}.swiftmodule'
-// CHECK-LOAD-PRIV: error: module 'Bar' is in package 'barpkg' but was built from a non-package interface; modules of the same package can only be loaded if built from source or package interface: {{.*}}/Bar.private.swiftinterface
+// CHECK-LOAD-PRIV: loaded module 'Bar'; source: '{{.*}}Bar.private.swiftinterface', loaded: '{{.*}}Bar-{{.*}}.swiftmodule'
+// CHECK-LOAD-PRIV: error: module 'Bar' is in package 'barpkg' but was built from a non-package interface; modules of the same package can only be loaded if built from source or package interface: {{.*}}Bar.private.swiftinterface
 
 // RUN: rm -rf %t/*.swiftmodule
 // RUN: rm -rf %t/Bar.private.swiftinterface
@@ -64,8 +72,8 @@
 // RUN:   -Rmodule-loading 2> %t/load-pub.output
 
 // RUN: %FileCheck -check-prefix=CHECK-LOAD-PUB %s < %t/load-pub.output
-// CHECK-LOAD-PUB: loaded module 'Bar'; source: '{{.*}}/Bar.swiftinterface', loaded: '{{.*}}/Bar-{{.*}}.swiftmodule'
-// CHECK-LOAD-PUB: error: module 'Bar' is in package 'barpkg' but was built from a non-package interface; modules of the same package can only be loaded if built from source or package interface: {{.*}}/Bar.swiftinterface
+// CHECK-LOAD-PUB: loaded module 'Bar'; source: '{{.*}}Bar.swiftinterface', loaded: '{{.*}}Bar-{{.*}}.swiftmodule'
+// CHECK-LOAD-PUB: error: module 'Bar' is in package 'barpkg' but was built from a non-package interface; modules of the same package can only be loaded if built from source or package interface: {{.*}}Bar.swiftinterface
 
 
 //--- Bar.swift