[test] Update ParseableInterface to ModuleInterface

Also remove uses of -emit-parseable-module-interface from tests

test/ModuleInterface/ModuleCache/Inputs/check-is-forwarding-module.py

@@ -0,0 +1,8 @@
+import sys
+
+for input_path in sys.argv[1:]:
+    with open(input_path, 'r') as yaml_file:
+        # Forwarding files are YAML files that start with '---'
+        if yaml_file.read(3) != '---':
+            print("swiftmodule '%s' is not a forwarding module!" % input_path)
+            sys.exit(1)

test/ModuleInterface/ModuleCache/Inputs/check-is-new.py

@@ -0,0 +1,27 @@
+#!/usr/bin/env python
+#
+# check-is-new.py - a more-legible way to read a timestamp test than test(1)
+#
+# This source file is part of the Swift.org open source project
+#
+# Copyright (c) 2014 - 2018 Apple Inc. and the Swift project authors
+# Licensed under Apache License v2.0 with Runtime Library Exception
+#
+# See https://swift.org/LICENSE.txt for license information
+# See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+#
+# ----------------------------------------------------------------------------
+#
+# Compares the mtime of the provided files to a constant "old" reference time.
+# Fails if any file is as-old-or-older than old.
+#
+# ----------------------------------------------------------------------------
+
+import os
+import sys
+
+OLD = 1390550700  # 2014-01-24T08:05:00+00:00
+for f in sys.argv[1:]:
+    if os.stat(f).st_mtime <= OLD:
+        print("%s is not new!" % f)
+        exit(1)

test/ModuleInterface/ModuleCache/Inputs/check-is-old.py

@@ -0,0 +1,27 @@
+#!/usr/bin/env python
+#
+# check-is-old.py - a more-legible way to read a timestamp test than test(1)
+#
+# This source file is part of the Swift.org open source project
+#
+# Copyright (c) 2014 - 2018 Apple Inc. and the Swift project authors
+# Licensed under Apache License v2.0 with Runtime Library Exception
+#
+# See https://swift.org/LICENSE.txt for license information
+# See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+#
+# ----------------------------------------------------------------------------
+#
+# Compares the mtime of the provided files to a constant "old" reference time.
+# Fails if any file has mtime not-equal to old.
+#
+# ----------------------------------------------------------------------------
+
+import os
+import sys
+
+OLD = 1390550700  # 2014-01-24T08:05:00+00:00
+for f in sys.argv[1:]:
+    if os.stat(f).st_mtime != OLD:
+        print("%s is not old!" % f)
+        exit(1)

test/ModuleInterface/ModuleCache/Inputs/force-module-loading-mode/Lib.swiftinterface

@@ -0,0 +1,9 @@
+// swift-interface-format-version: 1.0
+// swift-module-flags: -parse-stdlib -module-name Lib
+
+public struct FromInterface {
+  @inlinable public init() {}
+}
+public var testValue: FromInterface {
+  @inlinable get { return FromInterface() }
+}

test/ModuleInterface/ModuleCache/Inputs/make-old.py

@@ -0,0 +1,24 @@
+#!/usr/bin/env python
+#
+# make-old.py - /bin/touch that writes a constant "old" timestamp.
+#
+# This source file is part of the Swift.org open source project
+#
+# Copyright (c) 2014 - 2018 Apple Inc. and the Swift project authors
+# Licensed under Apache License v2.0 with Runtime Library Exception
+#
+# See https://swift.org/LICENSE.txt for license information
+# See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+#
+# ----------------------------------------------------------------------------
+#
+# Like /bin/touch, but writes a constant "old" timestamp.
+#
+# ----------------------------------------------------------------------------
+
+import os
+import sys
+
+OLD = 1390550700  # 2014-01-24T08:05:00+00:00
+for f in sys.argv[1:]:
+    os.utime(f, (OLD, OLD))

test/ModuleInterface/ModuleCache/Inputs/mock-sdk/ExportedLib.swiftinterface

@@ -0,0 +1,11 @@
+// swift-interface-format-version: 1.0
+// swift-module-flags: -parse-stdlib -module-name ExportedLib
+
+@_exported import SomeCModule
+
+public struct ExportedInterface {
+  @inlinable public init() {}
+}
+public var testValue: ExportedInterface {
+  @inlinable get { return ExportedInterface() }
+}

test/ModuleInterface/ModuleCache/Inputs/mock-sdk/SdkLib.swiftinterface

@@ -0,0 +1,8 @@
+// swift-interface-format-version: 1.0
+// swift-module-flags: -parse-stdlib -module-name SdkLib
+
+@_exported import ExportedLib
+
+public var testValue2: ExportedInterface {
+  @inlinable get { return ExportedInterface() }
+}

test/ModuleInterface/ModuleCache/Inputs/mock-sdk/usr/include/SomeCModule.h

@@ -0,0 +1 @@
+extern int x;

test/ModuleInterface/ModuleCache/Inputs/mock-sdk/usr/include/module.modulemap

@@ -0,0 +1,3 @@
+module SomeCModule {
+  header "SomeCModule.h"
+}

test/ModuleInterface/ModuleCache/Inputs/prebuilt-module-cache/Lib.swiftinterface

@@ -0,0 +1,9 @@
+// swift-interface-format-version: 1.0
+// swift-module-flags: -parse-stdlib -module-name Lib
+
+public struct FromInterface {
+  @inlinable public init() {}
+}
+public var testValue: FromInterface {
+  @inlinable get { return FromInterface() }
+}

test/ModuleInterface/ModuleCache/Inputs/prebuilt-module-cache/LibExporter.swiftinterface

@@ -0,0 +1,4 @@
+// swift-interface-format-version: 1.0
+// swift-module-flags: -parse-stdlib -module-name LibExporter
+
+@_exported import Lib

test/ModuleInterface/ModuleCache/ObjCAttrWithoutFoundation.swiftinterface

@@ -0,0 +1,10 @@
+// swift-interface-format-version: 1.0
+// swift-module-flags: -module-name ObjCAttrWithoutFoundation -enable-library-evolution -enable-objc-interop
+
+// RUN: %empty-directory(%t)
+// RUN: echo 'import ObjCAttrWithoutFoundation' | %target-swift-frontend -typecheck -module-cache-path %t -I %S -
+
+public class MyClass {
+  public init()
+  @objc deinit
+}

test/ModuleInterface/ModuleCache/RebuildRemarks/malformed-compiled-module.swift

@@ -0,0 +1,19 @@
+// RUN: %empty-directory(%t/ModuleCache)
+// RUN: %empty-directory(%t/Build)
+// RUN: %empty-directory(%t/PrebuiltCache)
+
+// 1. Create a dummy module
+// RUN: echo 'public func publicFunction() {}' > %t/TestModule.swift
+
+// 2. Create an interface for it
+// RUN: %target-swift-frontend -typecheck %t/TestModule.swift -emit-module-interface-path %t/Build/TestModule.swiftinterface -swift-version 5
+
+// 3. Create an empty .swiftmodule, which will force recompiling from the interface
+// RUN: touch %t/Build/TestModule.swiftmodule
+
+// 4. Try to import the malformed compiled module
+// RUN: %target-swift-frontend -typecheck -verify %s -I %t/Build -Rmodule-interface-rebuild -module-cache-path %t/ModuleCache
+
+import TestModule // expected-remark {{rebuilding module 'TestModule' from interface}}
+// expected-note @-1 {{is out of date}}
+// expected-note @-2 {{malformed}}

test/ModuleInterface/ModuleCache/RebuildRemarks/missing-dependency.swift

@@ -0,0 +1,31 @@
+// RUN: %empty-directory(%t/ModuleCache)
+// RUN: %empty-directory(%t/Build)
+
+// 1. Create a dummy module
+// RUN: echo 'public func publicFunction() {}' > %t/TestModule.swift
+
+// 2. Create both an interface and a compiled module for it
+// RUN: %target-swift-frontend -emit-module -o %t/Build/TestModule.swiftmodule %t/TestModule.swift -emit-module-interface-path %t/Build/TestModule.swiftinterface -swift-version 5 -module-name TestModule
+
+// 3. Make the compiled module unreadable so it gets added as a dependency but is not used
+// RUN: mv %t/Build/TestModule.swiftmodule %t/Build/TestModule.swiftmodule.moved-aside
+// RUN: echo 'this is unreadable' > %t/Build/TestModule.swiftmodule
+
+// 4. Try to import the module, which will create a cached module that depends on both the .swiftmodule and .swiftinterface
+// RUN: %target-swift-frontend -typecheck %s -I %t/Build -module-cache-path %t/ModuleCache
+
+// 5. Remove the .swiftmodule, which will result in a missing dependency note
+// RUN: rm %t/Build/TestModule.swiftmodule
+
+// 6. Rebuild with remarks enabled, make sure the missing dependency note is emitted
+// RUN: %target-swift-frontend -typecheck -verify %s -I %t/Build -Rmodule-interface-rebuild -module-cache-path %t/ModuleCache
+
+// 7. Put the module back, make the interface unreadable, and make sure the compiler succeeds
+// RUN: mv %t/Build/TestModule.swiftmodule.moved-aside %t/Build/TestModule.swiftmodule
+// RUN: mv %t/Build/TestModule.swiftinterface %t/Build/TestModule.swiftinterface.moved-aside
+// RUN: echo 'this is unreadable' > %t/Build/TestModule.swiftinterface
+// RUN: %target-swift-frontend -typecheck %s -I %t/Build -Rmodule-interface-rebuild -module-cache-path %t/ModuleCache
+
+import TestModule // expected-remark {{rebuilding module 'TestModule' from interface}}
+// expected-note @-1 {{cached module is out of date}}
+// expected-note @-2 {{dependency is missing}}

test/ModuleInterface/ModuleCache/RebuildRemarks/out-of-date-cached-module.swift

@@ -0,0 +1,24 @@
+// RUN: %empty-directory(%t/ModuleCache)
+// RUN: %empty-directory(%t/Build)
+
+// 1. Create a dummy module
+// RUN: echo 'public func publicFunction() {}' > %t/TestModule.swift
+
+// 2. Create an interface for it
+// RUN: %target-swift-frontend -typecheck %t/TestModule.swift -emit-module-interface-path %t/Build/TestModule.swiftinterface -swift-version 5
+
+// 3. Try to import the interface, which will pass and create a cached module
+// RUN: %target-swift-frontend -typecheck %s -I %t/Build -module-cache-path %t/ModuleCache
+
+// 3a. Make sure the test works on a fast machine
+// RUN: sleep 1
+
+// 4. Touch the interface so the cached module is no longer up-to-date
+// RUN: %{python} %S/../Inputs/make-old.py %t/Build/TestModule.swiftinterface
+
+// 5. Try to import the now out-of-date cached module
+// RUN: %target-swift-frontend -typecheck -verify %s -I %t/Build -Rmodule-interface-rebuild -module-cache-path %t/ModuleCache
+
+import TestModule // expected-remark {{rebuilding module 'TestModule' from interface}}
+// expected-note @-1 {{cached module is out of date}}
+// expected-note @-2 {{dependency is out of date}}

test/ModuleInterface/ModuleCache/RebuildRemarks/out-of-date-compiled-module.swift

@@ -0,0 +1,24 @@
+// RUN: %empty-directory(%t/ModuleCache)
+// RUN: %empty-directory(%t/Build)
+
+// 1. Create a dummy module
+// RUN: echo 'public func publicFunction() {}' > %t/TestModule.swift
+
+// 2. Create an interface for it
+// RUN: %target-swift-frontend -typecheck %t/TestModule.swift -emit-module-interface-path %t/Build/TestModule.swiftinterface -swift-version 5
+
+// 3. Build the .swiftinterface to a .swiftmodule, which will have a dependency on the interface
+// RUN: %target-swift-frontend -compile-module-from-interface -o %t/Build/TestModule.swiftmodule %t/Build/TestModule.swiftinterface
+
+// 3a. Make sure the test works on a fast machine
+// RUN: sleep 1
+
+// 4. Touch the interface so the module is no longer up-to-date
+// RUN: %{python} %S/../Inputs/make-old.py %t/Build/TestModule.swiftinterface
+
+// 5. Try to import the out-of-date compiled module
+// RUN: %target-swift-frontend -typecheck -verify %s -I %t/Build -Rmodule-interface-rebuild -module-cache-path %t/ModuleCache
+
+import TestModule // expected-remark {{rebuilding module 'TestModule' from interface}}
+// expected-note @-1 {{compiled module is out of date}}
+// expected-note @-2 {{dependency is out of date}}

test/ModuleInterface/ModuleCache/RebuildRemarks/out-of-date-forwarding-module.swift

@@ -0,0 +1,32 @@
+// RUN: %empty-directory(%t/ModuleCache)
+// RUN: %empty-directory(%t/Build)
+// RUN: %empty-directory(%t/PrebuiltCache)
+
+// 1. Create a dummy module
+// RUN: echo 'public func publicFunction() {}' > %t/TestModule.swift
+
+// 2. Create an interface for it
+// RUN: %target-swift-frontend -typecheck %t/TestModule.swift -emit-module-interface-path %t/Build/TestModule.swiftinterface -swift-version 5
+
+// 3. Build the .swiftinterface to a .swiftmodule in the prebuilt cache, which will have a dependency on the interface
+// RUN: %target-swift-frontend -compile-module-from-interface %t/Build/TestModule.swiftinterface -o %t/PrebuiltCache/TestModule.swiftmodule
+
+// 5. Try to import the prebuilt module (this should pass)
+// RUN: %target-swift-frontend -typecheck %s -I %t/Build -sdk %t -prebuilt-module-cache-path %t/PrebuiltCache -module-cache-path %t/ModuleCache
+
+// 6. Make sure we installed a forwarding module in the cache
+// RUN: %{python} %S/../Inputs/check-is-forwarding-module.py %t/ModuleCache/TestModule-*.swiftmodule
+
+// 7. Modify the interface so the forwarding module and prebuilt modules are no longer up-to-date
+// RUN: echo ' ' >> %t/Build/TestModule.swiftinterface
+
+// 8. Try to import the now out-of-date forwarding module, which will fail.
+//    It will also fail to load the prebuilt module after the forwarding module
+//    is rejected, meaning we'll get a second set of notes about the prebuilt module.
+// RUN: %target-swift-frontend -typecheck -verify %s -I %t/Build -Rmodule-interface-rebuild -sdk %t -prebuilt-module-cache-path %t/PrebuiltCache -module-cache-path %t/ModuleCache
+
+import TestModule // expected-remark {{rebuilding module 'TestModule' from interface}}
+// expected-note @-1 {{forwarding module is out of date}}
+// expected-note @-2 {{dependency is out of date}}
+// expected-note @-3 {{prebuilt module is out of date}}
+// expected-note @-4 {{dependency is out of date}}

test/ModuleInterface/ModuleCache/RebuildRemarks/rebuild-transitive-import.swift

@@ -0,0 +1,24 @@
+// RUN: %empty-directory(%t)
+// RUN: %empty-directory(%t/Build)
+// RUN: %empty-directory(%t/ModuleCache)
+
+// 1. Create a module called InnerModule, and put its interface into the build dir.
+// RUN: echo 'public func inInnerModule() {}' | %target-swift-frontend - -typecheck -emit-module-interface-path %t/Build/InnerModule.swiftinterface -enable-library-evolution -swift-version 5 -module-name InnerModule
+
+// 2. Build the .swiftinterface to a .swiftmodule, which will have a dependency on the interface
+// RUN: %target-swift-frontend -compile-module-from-interface -o %t/Build/InnerModule.swiftmodule %t/Build/InnerModule.swiftinterface
+
+// 3. Touch the interface so the module becomes out of date.
+// RUN: %{python} %S/../Inputs/make-old.py %t/Build/InnerModule.swiftinterface
+
+// 4. Create a module called OuterModule that imports InnerModule, and put its interface into the build dir.
+// RUN: echo 'import InnerModule' | %target-swift-frontend - -emit-module -o %t/Build/OuterModule.swiftmodule -module-name OuterModule -I %t/Build
+
+// 5. Build this file, and expect that InnerModule is out of date
+// RUN: %target-swift-frontend -typecheck %s -I %t/Build -Rmodule-interface-rebuild -module-cache-path %t/ModuleCache 2>&1 | %FileCheck %s
+
+import OuterModule
+
+// CHECK: rebuilding module 'InnerModule' from interface '{{.*}}{{[/\\]}}Build{{[/\\]}}InnerModule.swiftinterface'
+// CHECK: compiled module is out of date: '{{.*}}{{[/\\]}}Build{{[/\\]}}InnerModule.swiftmodule'
+// CHECK: dependency is out of date: '{{.*}}{{[/\\]}}Build{{[/\\]}}InnerModule.swiftinterface'

test/ModuleInterface/ModuleCache/SDKDependencies-disable-validation.swift

@@ -0,0 +1,192 @@
+// RUN: %empty-directory(%t)
+
+// 1) Build a prebuilt cache for our SDK
+//
+// RUN: mkdir %t/MCP %t/prebuilt-cache %t/my-sdk
+// RUN: cp -r %S/Inputs/mock-sdk/. %t/my-sdk
+// RUN: %target-swift-frontend -compile-module-from-interface -serialize-parseable-module-interface-dependency-hashes -sdk %t/my-sdk -prebuilt-module-cache-path %t/prebuilt-cache -I %t/my-sdk -module-cache-path %t/MCP -o %t/prebuilt-cache/ExportedLib.swiftmodule -track-system-dependencies -module-name ExportedLib %t/my-sdk/ExportedLib.swiftinterface
+// RUN: %target-swift-frontend -compile-module-from-interface -serialize-parseable-module-interface-dependency-hashes -sdk %t/my-sdk -prebuilt-module-cache-path %t/prebuilt-cache -I %t/my-sdk -module-cache-path %t/MCP -o %t/prebuilt-cache/SdkLib.swiftmodule -track-system-dependencies -module-name SdkLib %t/my-sdk/SdkLib.swiftinterface
+//
+// Check the prebuilt modules don't contain dependencies in the module cache, prebuilt cache, or resource dir
+// RUN: llvm-bcanalyzer -dump %t/prebuilt-cache/ExportedLib.swiftmodule | %FileCheck %s -check-prefix=PREBUILT
+// RUN: llvm-bcanalyzer -dump %t/prebuilt-cache/SdkLib.swiftmodule | %FileCheck %s -check-prefix=PREBUILT
+//
+// PREBUILT: MODULE_BLOCK
+// PREBUILT-NOT: FILE_DEPENDENCY {{.*[/\\]MCP[/\\]}}
+// PREBUILT-NOT: FILE_DEPENDENCY {{.*[/\\]prebuilt-cache[/\\]}}
+// PREBUILD-NOT: FILE_DEPENDENCY {{.*[/\\]lib[/\\]swift[/\\]}}
+//
+// Re-build them in the opposite order
+// RUN: %empty-directory(%t/prebuilt-cache)
+// RUN: %empty-directory(%t/MCP)
+// RUN: %target-swift-frontend -compile-module-from-interface -serialize-parseable-module-interface-dependency-hashes -sdk %t/my-sdk -prebuilt-module-cache-path %t/prebuilt-cache -I %t/my-sdk -module-cache-path %t/MCP -o %t/prebuilt-cache/SdkLib.swiftmodule -track-system-dependencies -module-name SdkLib %t/my-sdk/SdkLib.swiftinterface
+// RUN: %target-swift-frontend -compile-module-from-interface -serialize-parseable-module-interface-dependency-hashes -sdk %t/my-sdk -prebuilt-module-cache-path %t/prebuilt-cache -I %t/my-sdk -module-cache-path %t/MCP -o %t/prebuilt-cache/ExportedLib.swiftmodule -track-system-dependencies -module-name ExportedLib %t/my-sdk/ExportedLib.swiftinterface
+//
+// Check they still don't contain dependencies in the module cache or prebuilt cache
+// RUN: llvm-bcanalyzer -dump %t/prebuilt-cache/ExportedLib.swiftmodule | %FileCheck %s -check-prefix=PREBUILT
+// RUN: llvm-bcanalyzer -dump %t/prebuilt-cache/SdkLib.swiftmodule | %FileCheck %s -check-prefix=PREBUILT
+//
+// RUN: %empty-directory(%t/MCP)
+// RUN: echo '1: PASSED'
+
+
+// 2) Baseline check: Make sure we use the interface when not passing the prebuilt module cache path
+//
+// RUN: %target-swift-frontend -typecheck -I %t/my-sdk -sdk %t/my-sdk -module-cache-path %t/MCP -emit-dependencies-path %t/dummy.d -track-system-dependencies -disable-modules-validate-system-headers %s
+//
+// Check SdkLib and ExportedLib are in the module cache
+// RUN: test -f %t/MCP/ExportedLib-*.swiftmodule
+// RUN: test -f %t/MCP/SdkLib-*.swiftmodule
+//
+// Check they are *not* forwarding modules
+// RUN: not %{python} %S/Inputs/check-is-forwarding-module.py %t/MCP/SdkLib-*.swiftmodule
+// RUN: not %{python} %S/Inputs/check-is-forwarding-module.py %t/MCP/ExportedLib-*.swiftmodule
+//
+// Check they don't contain dependencies in the module cache (..or prebuilt cache)
+// RUN: llvm-bcanalyzer -dump %t/MCP/SdkLib-*.swiftmodule | %FileCheck %s -check-prefix=PREBUILT
+// RUN: llvm-bcanalyzer -dump %t/MCP/ExportedLib-*.swiftmodule | %FileCheck %s -check-prefix=PREBUILT
+//
+// Check we didn't emit anything from the cache in the .d file either
+// RUN: cat %t/dummy.d | %FileCheck %s -check-prefix=DEPFILE-NEGATIVE
+// RUN: cat %t/dummy.d | %FileCheck %s -check-prefix=DEPFILE
+//
+// DEPFILE-NEGATIVE-NOT: {{[/\\]MCP[/\\]}}
+// DEPFILE-NEGATIVE-NOT: {{[/\\]prebuilt-cache[/\\]}}
+//
+// DEPFILE-DAG: SomeCModule.h
+// DEPFILE-DAG: SdkLib.swiftinterface
+// DEPFILE-DAG: ExportedLib.swiftinterface
+// DEPFILE-DAG: SDKDependencies-disable-validation.swift
+//
+// RUN: %empty-directory(%t/MCP)
+// RUN: echo '2: PASSED'
+
+
+// 3) Baseline check: Make sure we use the the prebuilt module cache when using the SDK it was built with
+//
+// RUN: %target-swift-frontend -typecheck -I %t/my-sdk -sdk %t/my-sdk -prebuilt-module-cache-path %t/prebuilt-cache -module-cache-path %t/MCP -emit-dependencies-path %t/dummy.d -track-system-dependencies -disable-modules-validate-system-headers %s
+//
+// Check SdkLib and ExportedLib are in the module cache
+// RUN: test -f %t/MCP/SdkLib-*.swiftmodule
+// RUN: test -f %t/MCP/ExportedLib-*.swiftmodule
+//
+// Check they *are* forwarding modules
+// RUN: %{python} %S/Inputs/check-is-forwarding-module.py %t/MCP/SdkLib-*.swiftmodule
+// RUN: %{python} %S/Inputs/check-is-forwarding-module.py %t/MCP/ExportedLib-*.swiftmodule
+//
+// Check they contain the expected dependencies
+// RUN: cat %t/MCP/ExportedLib-*.swiftmodule | %FileCheck %s -check-prefix=EXLIB
+// RUN: cat %t/MCP/SdkLib-*.swiftmodule | %FileCheck %s -check-prefixes=EXLIB,SDKLIB
+//
+// EXLIB: dependencies:
+// EXLIB-DAG: path: '{{usr[/\\]include[/\\]}}module.modulemap'
+// EXLIB-DAG: path: '{{usr[/\\]include[/\\]}}SomeCModule.h'
+// EXLIB-DAG: path: ExportedLib.swiftinterface
+// SDKLIB-DAG: SdkLib.swiftinterface
+//
+// Check they don't contain any dependencies from either cache other than themselves
+// RUN: cat %t/MCP/ExportedLib-*.swiftmodule | %FileCheck %s -check-prefix=NOCACHE -DLIB_NAME=ExportedLib
+// RUN: cat %t/MCP/SdkLib-*.swiftmodule | %FileCheck %s -check-prefix=NOCACHE -DLIB_NAME=SdkLib
+//
+// NOCACHE: dependencies:
+// NOCACHE-NOT: {{[/\\]prebuilt-cache[/\\]}}
+// NOCACHE-NOT: {{[/\\]MCP[/\\]}}
+// NOCACHE: {{[/\\]prebuilt-cache[/\\]}}[[LIB_NAME]].swiftmodule
+// NOCACHE-NOT: {{[/\\]prebuilt-cache[/\\]}}
+// NOCACHE-NOT: {{[/\\]MCP[/\\]}}
+//
+// Check we didn't emit anything from the cache in the .d file either
+// RUN: cat %t/dummy.d | %FileCheck %s -check-prefix=DEPFILE-NEGATIVE
+// RUN: cat %t/dummy.d | %FileCheck %s -check-prefix=DEPFILE
+//
+// RUN: echo '3: PASSED'
+
+
+// 4) Now change the SDK's content WITHOUT clearing the module cache and check
+// that it doesn't change anything...
+//
+// RUN: echo "// size change" >> %t/my-sdk/SdkLib.swiftinterface
+// RUN: %target-swift-frontend -typecheck -I %t/my-sdk -sdk %t/my-sdk -prebuilt-module-cache-path %t/prebuilt-cache -module-cache-path %t/MCP -emit-dependencies-path %t/dummy.d -track-system-dependencies -disable-modules-validate-system-headers %s
+//
+// Check SDKLib and ExportedLib are in the module cache
+// RUN: test -f %t/MCP/SdkLib-*.swiftmodule
+// RUN: test -f %t/MCP/ExportedLib-*.swiftmodule
+//
+// Check that they're both still forwarding modules, because we didn't stat
+// the system dependencies.
+// RUN: %{python} %S/Inputs/check-is-forwarding-module.py %t/MCP/ExportedLib-*.swiftmodule
+// RUN: %{python} %S/Inputs/check-is-forwarding-module.py %t/MCP/SdkLib-*.swiftmodule
+//
+// Check ExportedLib still contains the same dependencies
+// RUN: cat %t/MCP/ExportedLib-*.swiftmodule | %FileCheck %s -check-prefix=EXLIB
+// RUN: cat %t/MCP/ExportedLib-*.swiftmodule | %FileCheck %s -check-prefix=NOCACHE -DLIB_NAME=ExportedLib
+//
+// RUN: echo '4: PASSED'
+
+// 5) ...but if we clear the module cache and start over, we won't be using the
+// prebuilt module anymore for SDKLib.
+//
+// RUN: %empty-directory(%t/MCP)
+// RUN: %target-swift-frontend -typecheck -I %t/my-sdk -sdk %t/my-sdk -prebuilt-module-cache-path %t/prebuilt-cache -module-cache-path %t/MCP -emit-dependencies-path %t/dummy.d -track-system-dependencies -disable-modules-validate-system-headers %s
+//
+// Check SDKLib and ExportedLib are in the module cache
+// RUN: test -f %t/MCP/SdkLib-*.swiftmodule
+// RUN: test -f %t/MCP/ExportedLib-*.swiftmodule
+//
+// Check ExportedLib is still a forwarding module and SdkLib is not
+// RUN: %{python} %S/Inputs/check-is-forwarding-module.py %t/MCP/ExportedLib-*.swiftmodule
+// RUN: not %{python} %S/Inputs/check-is-forwarding-module.py %t/MCP/SdkLib-*.swiftmodule
+//
+// Check ExportedLib still contains the same dependencies
+// RUN: cat %t/MCP/ExportedLib-*.swiftmodule | %FileCheck %s -check-prefix=EXLIB
+// RUN: cat %t/MCP/ExportedLib-*.swiftmodule | %FileCheck %s -check-prefix=NOCACHE -DLIB_NAME=ExportedLib
+//
+// Check SdkLib doesn't contain dependencies in the module cache or prebuilt cache
+// RUN: llvm-bcanalyzer -dump %t/MCP/SdkLib-*.swiftmodule | %FileCheck %s -check-prefix=PREBUILT
+//
+// RUN: echo '5: PASSED'
+
+// 6) If we do one more change, we won't rebuild SdkLib *again*...
+//
+// RUN: %{python} %S/Inputs/make-old.py %t/MCP/SdkLib-*.swiftmodule
+// RUN: echo "// size change" >> %t/my-sdk/SdkLib.swiftinterface
+// RUN: %target-swift-frontend -typecheck -I %t/my-sdk -sdk %t/my-sdk -prebuilt-module-cache-path %t/prebuilt-cache -module-cache-path %t/MCP -emit-dependencies-path %t/dummy.d -track-system-dependencies -disable-modules-validate-system-headers %s
+//
+// Check SDKLib and ExportedLib are in the module cache
+// RUN: test -f %t/MCP/SdkLib-*.swiftmodule
+// RUN: test -f %t/MCP/ExportedLib-*.swiftmodule
+//
+// Check ExportedLib is still a forwarding module and SdkLib is not
+// RUN: %{python} %S/Inputs/check-is-forwarding-module.py %t/MCP/ExportedLib-*.swiftmodule
+// RUN: not %{python} %S/Inputs/check-is-forwarding-module.py %t/MCP/SdkLib-*.swiftmodule
+//
+// Check SdkLib hasn't been rebuilt.
+// RUN: %{python} %S/Inputs/check-is-old.py %t/MCP/SdkLib-*.swiftmodule
+//
+// RUN: echo '6: PASSED'
+
+// 7) ...until we turn off -disable-modules-validate-system-headers.
+//
+// RUN: %{python} %S/Inputs/make-old.py %t/MCP/SdkLib-*.swiftmodule
+// RUN: echo "// size change" >> %t/my-sdk/SdkLib.swiftinterface
+// RUN: %target-swift-frontend -typecheck -I %t/my-sdk -sdk %t/my-sdk -prebuilt-module-cache-path %t/prebuilt-cache -module-cache-path %t/MCP -emit-dependencies-path %t/dummy.d -track-system-dependencies %s
+//
+// Check SDKLib and ExportedLib are in the module cache
+// RUN: test -f %t/MCP/SdkLib-*.swiftmodule
+// RUN: test -f %t/MCP/ExportedLib-*.swiftmodule
+//
+// Check ExportedLib is still a forwarding module and SdkLib is not
+// RUN: %{python} %S/Inputs/check-is-forwarding-module.py %t/MCP/ExportedLib-*.swiftmodule
+// RUN: not %{python} %S/Inputs/check-is-forwarding-module.py %t/MCP/SdkLib-*.swiftmodule
+//
+// Check SdkLib has been rebuilt.
+// RUN: not %{python} %S/Inputs/check-is-old.py %t/MCP/SdkLib-*.swiftmodule
+//
+// RUN: echo '7: PASSED'
+
+
+import SdkLib
+
+func foo() -> ExportedInterface {
+	return x > 3 ? testValue : testValue2
+}

test/ModuleInterface/ModuleCache/SDKDependencies.swift

@@ -0,0 +1,208 @@
+// RUN: %empty-directory(%t)
+
+// 1) Build a prebuilt cache for our SDK
+//
+// RUN: mkdir %t/MCP %t/prebuilt-cache %t/my-sdk
+// RUN: cp -r %S/Inputs/mock-sdk/. %t/my-sdk
+// RUN: %target-swift-frontend -compile-module-from-interface -serialize-parseable-module-interface-dependency-hashes -sdk %t/my-sdk -prebuilt-module-cache-path %t/prebuilt-cache -I %t/my-sdk -module-cache-path %t/MCP -o %t/prebuilt-cache/ExportedLib.swiftmodule -track-system-dependencies -module-name ExportedLib %t/my-sdk/ExportedLib.swiftinterface
+// RUN: %target-swift-frontend -compile-module-from-interface -serialize-parseable-module-interface-dependency-hashes -sdk %t/my-sdk -prebuilt-module-cache-path %t/prebuilt-cache -I %t/my-sdk -module-cache-path %t/MCP -o %t/prebuilt-cache/SdkLib.swiftmodule -track-system-dependencies -module-name SdkLib %t/my-sdk/SdkLib.swiftinterface
+//
+// Check the prebuilt modules don't contain dependencies in the module cache, prebuilt cache, or resource dir
+// RUN: llvm-bcanalyzer -dump %t/prebuilt-cache/ExportedLib.swiftmodule | %FileCheck %s -check-prefix=PREBUILT
+// RUN: llvm-bcanalyzer -dump %t/prebuilt-cache/SdkLib.swiftmodule | %FileCheck %s -check-prefix=PREBUILT
+//
+// PREBUILT: MODULE_BLOCK
+// PREBUILT-NOT: FILE_DEPENDENCY {{.*[/\\]MCP[/\\]}}
+// PREBUILT-NOT: FILE_DEPENDENCY {{.*[/\\]prebuilt-cache[/\\]}}
+// PREBUILD-NOT: FILE_DEPENDENCY {{.*[/\\]lib[/\\]swift[/\\]}}
+//
+// Re-build them in the opposite order
+// RUN: %empty-directory(%t/prebuilt-cache)
+// RUN: %empty-directory(%t/MCP)
+// RUN: %target-swift-frontend -compile-module-from-interface -serialize-parseable-module-interface-dependency-hashes -sdk %t/my-sdk -prebuilt-module-cache-path %t/prebuilt-cache -I %t/my-sdk -module-cache-path %t/MCP -o %t/prebuilt-cache/SdkLib.swiftmodule -track-system-dependencies -module-name SdkLib %t/my-sdk/SdkLib.swiftinterface
+// RUN: %target-swift-frontend -compile-module-from-interface -serialize-parseable-module-interface-dependency-hashes -sdk %t/my-sdk -prebuilt-module-cache-path %t/prebuilt-cache -I %t/my-sdk -module-cache-path %t/MCP -o %t/prebuilt-cache/ExportedLib.swiftmodule -track-system-dependencies -module-name ExportedLib %t/my-sdk/ExportedLib.swiftinterface
+//
+// Check they still don't contain dependencies in the module cache or prebuilt cache
+// RUN: llvm-bcanalyzer -dump %t/prebuilt-cache/ExportedLib.swiftmodule | %FileCheck %s -check-prefix=PREBUILT
+// RUN: llvm-bcanalyzer -dump %t/prebuilt-cache/SdkLib.swiftmodule | %FileCheck %s -check-prefix=PREBUILT
+//
+// RUN: %empty-directory(%t/MCP)
+// RUN: echo '1: PASSED'
+
+
+// 2) Baseline check: Make sure we use the interface when not passing the prebuilt module cache path
+//
+// RUN: %target-swift-frontend -typecheck -I %t/my-sdk -sdk %t/my-sdk -module-cache-path %t/MCP -emit-dependencies-path %t/dummy.d -track-system-dependencies %s
+//
+// Check SdkLib and ExportedLib are in the module cache
+// RUN: test -f %t/MCP/ExportedLib-*.swiftmodule
+// RUN: test -f %t/MCP/SdkLib-*.swiftmodule
+//
+// Check they are *not* forwarding modules
+// RUN: not %{python} %S/Inputs/check-is-forwarding-module.py %t/MCP/SdkLib-*.swiftmodule
+// RUN: not %{python} %S/Inputs/check-is-forwarding-module.py %t/MCP/ExportedLib-*.swiftmodule
+//
+// Check they don't contain dependencies in the module cache (..or prebuilt cache)
+// RUN: llvm-bcanalyzer -dump %t/MCP/SdkLib-*.swiftmodule | %FileCheck %s -check-prefix=PREBUILT
+// RUN: llvm-bcanalyzer -dump %t/MCP/ExportedLib-*.swiftmodule | %FileCheck %s -check-prefix=PREBUILT
+//
+// Check we didn't emit anything from the cache in the .d file either
+// RUN: cat %t/dummy.d | %FileCheck %s -check-prefix=DEPFILE-NEGATIVE
+// RUN: cat %t/dummy.d | %FileCheck %s -check-prefix=DEPFILE
+//
+// DEPFILE-NEGATIVE-NOT: {{[/\\]MCP[/\\]}}
+// DEPFILE-NEGATIVE-NOT: {{[/\\]prebuilt-cache[/\\]}}
+//
+// DEPFILE-DAG: SomeCModule.h
+// DEPFILE-DAG: SdkLib.swiftinterface
+// DEPFILE-DAG: ExportedLib.swiftinterface
+// DEPFILE-DAG: SDKDependencies.swift
+//
+// RUN: %empty-directory(%t/MCP)
+// RUN: echo '2: PASSED'
+
+
+// 3) Baseline check: Make sure we use the the prebuilt module cache when using the SDK it was built with
+//
+// RUN: %target-swift-frontend -typecheck -I %t/my-sdk -sdk %t/my-sdk -prebuilt-module-cache-path %t/prebuilt-cache -module-cache-path %t/MCP -emit-dependencies-path %t/dummy.d -track-system-dependencies %s
+//
+// Check SdkLib and ExportedLib are in the module cache
+// RUN: test -f %t/MCP/SdkLib-*.swiftmodule
+// RUN: test -f %t/MCP/ExportedLib-*.swiftmodule
+//
+// Check they *are* forwarding modules
+// RUN: %{python} %S/Inputs/check-is-forwarding-module.py %t/MCP/SdkLib-*.swiftmodule
+// RUN: %{python} %S/Inputs/check-is-forwarding-module.py %t/MCP/ExportedLib-*.swiftmodule
+//
+// Check they contain the expected dependencies
+// RUN: cat %t/MCP/ExportedLib-*.swiftmodule | %FileCheck %s -check-prefix=EXLIB
+// RUN: cat %t/MCP/SdkLib-*.swiftmodule | %FileCheck %s -check-prefixes=EXLIB,SDKLIB
+//
+// EXLIB: dependencies:
+// EXLIB-DAG: path: '{{usr[/\\]include[/\\]}}module.modulemap'
+// EXLIB-DAG: path: '{{usr[/\\]include[/\\]}}SomeCModule.h'
+// EXLIB-DAG: path: ExportedLib.swiftinterface
+// SDKLIB-DAG: SdkLib.swiftinterface
+//
+// Check they don't contain any dependencies from either cache other than themselves
+// RUN: cat %t/MCP/ExportedLib-*.swiftmodule | %FileCheck %s -check-prefix=NOCACHE -DLIB_NAME=ExportedLib
+// RUN: cat %t/MCP/SdkLib-*.swiftmodule | %FileCheck %s -check-prefix=NOCACHE -DLIB_NAME=SdkLib
+//
+// NOCACHE: dependencies:
+// NOCACHE-NOT: {{[/\\]prebuilt-cache[/\\]}}
+// NOCACHE-NOT: {{[/\\]MCP[/\\]}}
+// NOCACHE: {{[/\\]prebuilt-cache[/\\]}}[[LIB_NAME]].swiftmodule
+// NOCACHE-NOT: {{[/\\]prebuilt-cache[/\\]}}
+// NOCACHE-NOT: {{[/\\]MCP[/\\]}}
+//
+// Check we didn't emit anything from the cache in the .d file either
+// RUN: cat %t/dummy.d | %FileCheck %s -check-prefix=DEPFILE-NEGATIVE
+// RUN: cat %t/dummy.d | %FileCheck %s -check-prefix=DEPFILE
+//
+// RUN: %empty-directory(%t/MCP)
+// RUN: echo '3: PASSED'
+
+
+// 4) Move the SDK without changing its contents
+//
+// RUN: mv %t/my-sdk %t/my-new-sdk
+// RUN: mkdir %t/new-dir
+// RUN: mv %t/prebuilt-cache %t/new-dir/
+// RUN: %target-swift-frontend -typecheck -I %t/my-new-sdk -sdk %t/my-new-sdk -prebuilt-module-cache-path %t/new-dir/prebuilt-cache -module-cache-path %t/MCP -emit-dependencies-path %t/dummy.d -track-system-dependencies %s
+//
+// Check SdkLib and ExportedLib are in the module cache
+// RUN: test -f %t/MCP/SdkLib-*.swiftmodule
+// RUN: test -f %t/MCP/ExportedLib-*.swiftmodule
+//
+// Check they are still both forwarding modules
+// RUN: %{python} %S/Inputs/check-is-forwarding-module.py %t/MCP/SdkLib-*.swiftmodule
+// RUN: %{python} %S/Inputs/check-is-forwarding-module.py %t/MCP/ExportedLib-*.swiftmodule
+//
+// Check they contain the expected dependencies
+// RUN: cat %t/MCP/ExportedLib-*.swiftmodule | %FileCheck %s -check-prefix=NEW-EXLIB
+// RUN: cat %t/MCP/SdkLib-*.swiftmodule | %FileCheck %s -check-prefixes=NEW-EXLIB,NEW-SDKLIB
+//
+// NEW-EXLIB-DAG: path: '{{usr[/\\]include[/\\]}}module.modulemap'
+// NEW-EXLIB-DAG: path: '{{usr[/\\]include[/\\]}}SomeCModule.h'
+// NEW-EXLIB-DAG: path: ExportedLib.swiftinterface
+// NEW-SDKLIB-DAG: path: SdkLib.swiftinterface
+//
+// Check they don't contain dependencies from the module cache, old prebuilt
+// cache, or new prebuilt cache
+// RUN: cat %t/MCP/ExportedLib-*.swiftmodule | %FileCheck %s -check-prefix=NOCACHE -DLIB_NAME=ExportedLib
+// RUN: cat %t/MCP/SdkLib-*.swiftmodule | %FileCheck %s -check-prefix=NOCACHE -DLIB_NAME=SdkLib
+//
+// Check we didn't emit anything from the cache in the .d file either
+// RUN: cat %t/dummy.d | %FileCheck %s -check-prefix=DEPFILE-NEGATIVE
+// RUN: cat %t/dummy.d | %FileCheck %s -check-prefix=DEPFILE
+//
+// RUN: %empty-directory(%t/MCP)
+// RUN: echo '4: PASSED'
+
+
+// 5) Now change the SDK's content and check it no longer uses the prebuilt modules
+//
+// RUN: echo "// size change" >> %t/my-new-sdk/SdkLib.swiftinterface
+// RUN: %target-swift-frontend -typecheck -I %t/my-new-sdk -sdk %t/my-new-sdk -prebuilt-module-cache-path %t/new-dir/prebuilt-cache -module-cache-path %t/MCP -emit-dependencies-path %t/dummy.d -track-system-dependencies %s
+//
+// Check SDKLib and ExportedLib are in the module cache
+// RUN: test -f %t/MCP/SdkLib-*.swiftmodule
+// RUN: test -f %t/MCP/ExportedLib-*.swiftmodule
+//
+// Check ExportedLib is still a forwarding module and SdkLib is not
+// RUN: %{python} %S/Inputs/check-is-forwarding-module.py %t/MCP/ExportedLib-*.swiftmodule
+// RUN: not %{python} %S/Inputs/check-is-forwarding-module.py %t/MCP/SdkLib-*.swiftmodule
+//
+// Check ExportedLib still contains the same dependencies
+// RUN: cat %t/MCP/ExportedLib-*.swiftmodule | %FileCheck %s -check-prefix=NEW-EXLIB
+// RUN: cat %t/MCP/ExportedLib-*.swiftmodule | %FileCheck %s -check-prefix=NOCACHE -DLIB_NAME=ExportedLib
+//
+// Check SdkLib doesn't contain dependencies in the module cache or prebuilt cache
+// RUN: llvm-bcanalyzer -dump %t/MCP/SdkLib-*.swiftmodule | %FileCheck %s -check-prefix=PREBUILT
+//
+// RUN: %empty-directory(%t/MCP)
+//
+// RUN: echo "// size change" >> %t/my-new-sdk/usr/include/SomeCModule.h
+// RUN: %target-swift-frontend -typecheck -I %t/my-new-sdk -sdk %t/my-new-sdk -prebuilt-module-cache-path %t/new-prebuilt-cache -module-cache-path %t/MCP -emit-dependencies-path %t/dummy.d -track-system-dependencies %s
+//
+// Check SDKLib and ExportLib are in the module cache
+// RUN: test -f %t/MCP/SdkLib-*.swiftmodule
+// RUN: test -f %t/MCP/ExportedLib-*.swiftmodule
+//
+// Check neither are forwarding modules
+// RUN: not %{python} %S/Inputs/check-is-forwarding-module.py %t/MCP/SdkLib-*.swiftmodule
+// RUN: not %{python} %S/Inputs/check-is-forwarding-module.py %t/MCP/ExportedLib-*.swiftmodule
+//
+// Check neither contains dependencies in the module cache or prebuilt cache
+// RUN: llvm-bcanalyzer -dump %t/MCP/ExportedLib-*.swiftmodule | %FileCheck %s -check-prefix=PREBUILT
+// RUN: llvm-bcanalyzer -dump %t/MCP/SdkLib-*.swiftmodule | %FileCheck %s -check-prefix=PREBUILT
+//
+// Check we didn't emit anything from the cache in the .d file either
+// RUN: cat %t/dummy.d | %FileCheck %s -check-prefix=DEPFILE-NEGATIVE
+// RUN: cat %t/dummy.d | %FileCheck %s -check-prefix=DEPFILE
+//
+// RUN: echo '5: PASSED'
+
+
+// 6) Keeping the existing cache, update ExportedLib to no longer depend on SomeCModule
+//
+// RUN: grep -v import %t/my-new-sdk/ExportedLib.swiftinterface > %t/my-new-sdk/ExportedLib.swiftinterface.updated
+// RUN: mv %t/my-new-sdk/ExportedLib.swiftinterface.updated %t/my-new-sdk/ExportedLib.swiftinterface
+//
+// RUN: sed -e 's/x > 3/5 > 3/g' %s | %target-swift-frontend -typecheck -I %t/my-new-sdk -sdk %t/my-new-sdk -prebuilt-module-cache-path %t/new-dir/prebuilt-cache -module-cache-path %t/MCP -emit-dependencies-path %t/dummy.d -track-system-dependencies -
+//
+// Check we don't have SomeCModule listed in dependencies
+// RUN: cat %t/dummy.d | %FileCheck %s -check-prefixes=DEPFILE-NEGATIVE,DEPCHANGE-NEGATIVE
+// RUN: cat %t/dummy.d | %FileCheck %s -check-prefix=DEPCHANGE
+//
+// DEPCHANGE-NEGATIVE-NOT: SomeCModule.h
+//
+// DEPCHANGE-DAG: SdkLib.swiftinterface
+// DEPCHANGE-DAG: ExportedLib.swiftinterface
+// DEPCHANGE-DAG: SDKDependencies.swift
+
+import SdkLib
+
+func foo() -> ExportedInterface {
+	return x > 3 ? testValue : testValue2
+}

test/ModuleInterface/ModuleCache/SerializedSIL.swiftinterface

@@ -0,0 +1,54 @@
+// swift-interface-format-version: 1.0
+// swift-module-flags: -module-name SerializedSIL -enable-library-evolution
+
+// RUN: %empty-directory(%t)
+// RUN: echo 'import SerializedSIL' | %target-swift-frontend -typecheck -module-cache-path %t -I %S -
+// RUN: %target-sil-opt -disable-sil-linking %t/SerializedSIL-*.swiftmodule -module-name SerializedSIL > %t/SerializedSIL.sil
+// RUN: %FileCheck %s < %t/SerializedSIL.sil
+// RUN: %FileCheck -check-prefix NEGATIVE %s < %t/SerializedSIL.sil
+
+public class TestClass {
+    public init()
+    public func method()
+    public subscript(_: Int) -> Void { get set }
+    public var prop: Int { get set }
+    public var storedProp: Int
+    public static var staticProp: Int
+    deinit
+}
+
+public class TestEmptyClass {
+}
+
+public struct TestEmptyStruct {
+}
+
+public enum TestEnum {
+    case a
+    public init()
+    public func method()
+    public subscript(_: Int) -> Void { get set }
+    public var prop: Int { get set }
+    public static var staticProp: Int
+}
+
+public struct TestStruct {
+    public init()
+    public func method()
+    public subscript(_: Int) -> Void { get set }
+    public var prop: Int { get set }
+    public var storedProp: Int
+    public static var staticProp: Int
+}
+
+public let globalWithNoAccessors: Int
+public var readOnlyVar: Int { get }
+public var readWriteVar: Int { get set }
+public func verySimpleFunction()
+
+// CHECK: sil [serialized] [exact_self_class] [canonical] @$s13SerializedSIL9TestClassCACycfC : $@convention(method) (@thick TestClass.Type) -> @owned TestClass {
+
+// NEGATIVE-NOT: {{sil .*@.+storedProp}}
+
+// NEGATIVE-NOT: sil_vtable
+// NEGATIVE-NOT: sil_witness_table

test/ModuleInterface/ModuleCache/SystemDependencies.swiftinterface

@@ -0,0 +1,55 @@
+// swift-interface-format-version: 1.0
+// swift-module-flags: -module-name SystemDependencies
+
+// RUN: %empty-directory(%t)
+// RUN: cp -r %S/Inputs/mock-sdk %t/mock-sdk
+
+// RUN: echo 'import SystemDependencies' | %target-swift-frontend -typecheck - -I %S -sdk %t/mock-sdk -module-cache-path %t/MCP -emit-dependencies-path %t/dummy.d
+// RUN: test -f %t/MCP/SystemDependencies*.swiftmodule
+// RUN: %FileCheck -check-prefix NEGATIVE %s < %t/dummy.d
+// RUN: %{python} %S/Inputs/make-old.py %t/MCP/SystemDependencies*.swiftmodule
+
+// Baseline: running the same command again doesn't rebuild the cached module.
+// RUN: echo 'import SystemDependencies' | %target-swift-frontend -typecheck - -I %S -sdk %t/mock-sdk -module-cache-path %t/MCP -emit-dependencies-path %t/dummy.d
+// RUN: %{python} %S/Inputs/check-is-old.py %t/MCP/SystemDependencies*.swiftmodule
+
+// Now try changing the contents.
+// RUN: echo "// size change" >> %t/mock-sdk/usr/include/SomeCModule.h
+// RUN: echo 'import SystemDependencies' | %target-swift-frontend -typecheck - -I %S -sdk %t/mock-sdk -module-cache-path %t/MCP -emit-dependencies-path %t/dummy.d
+// RUN: %{python} %S/Inputs/check-is-old.py %t/MCP/SystemDependencies*.swiftmodule
+
+// Okay, now let's try again with system dependency tracking on.
+// RUN: echo 'import SystemDependencies' | %target-swift-frontend -typecheck - -I %S -sdk %t/mock-sdk -module-cache-path %t/MCP-system -emit-dependencies-path %t/dummy.d -track-system-dependencies
+// RUN: test -f %t/MCP-system/SystemDependencies*.swiftmodule
+// RUN: %FileCheck -check-prefix CHECK %s < %t/dummy.d
+// RUN: llvm-bcanalyzer -dump %t/MCP-system/SystemDependencies*.swiftmodule | %FileCheck -check-prefix CHECK-DUMP %s
+// RUN: %{python} %S/Inputs/make-old.py %t/MCP-system/SystemDependencies*.swiftmodule
+
+// Baseline: running the same command again doesn't rebuild the cached module.
+// RUN: echo 'import SystemDependencies' | %target-swift-frontend -typecheck - -I %S -sdk %t/mock-sdk -module-cache-path %t/MCP-system -emit-dependencies-path %t/dummy.d -track-system-dependencies
+// RUN: %{python} %S/Inputs/check-is-old.py %t/MCP-system/SystemDependencies*.swiftmodule
+
+// Now try changing the contents.
+// RUN: echo "// size change" >> %t/mock-sdk/usr/include/SomeCModule.h
+// RUN: echo 'import SystemDependencies' | %target-swift-frontend -typecheck - -I %S -sdk %t/mock-sdk -module-cache-path %t/MCP-system -emit-dependencies-path %t/dummy.d -track-system-dependencies
+// RUN: %{python} %S/Inputs/check-is-new.py %t/MCP-system/SystemDependencies*.swiftmodule
+
+// Check that it picked a different cache key.
+// RUN: %empty-directory(%t/MCP-combined)
+// RUN: cp %t/MCP/SystemDependencies*.swiftmodule %t/MCP-combined
+// RUN: cp %t/MCP-system/SystemDependencies*.swiftmodule %t/MCP-combined
+// RUN: ls -1 %t/MCP-combined | %FileCheck %s -check-prefix=MODULECACHE
+
+// NEGATIVE-NOT: SomeCModule.h
+// CHECK: SomeCModule.h
+
+// CHECK-DUMP-NOT: usr{{[/\\]}}include
+// CHECK-DUMP: DEPENDENCY_DIRECTORY{{.+}}'usr{{[/\\]}}include'
+// CHECK-DUMP-NEXT: FILE_DEPENDENCY{{.+}}'module.modulemap'
+// CHECK-DUMP-NOT: FILE_DEPENDENCY{{.+}}'SomeCModule.h'
+// CHECK-DUMP: FILE_DEPENDENCY{{.+}}'SomeCModule.h'
+// CHECK-DUMP-NOT: usr{{[/\\]}}include
+
+// MODULECACHE-COUNT-2: SystemDependencies-{{[^ ]+}}.swiftmodule
+
+import SomeCModule

test/ModuleInterface/ModuleCache/WrongName.swiftinterface

@@ -0,0 +1,7 @@
+// swift-interface-format-version: 1.0
+// swift-module-flags: -module-name DreadPirateRoberts
+
+// RUN: %empty-directory(%t)
+// RUN: echo 'import WrongName' | not %target-swift-frontend -typecheck -module-cache-path %t -I %S - 2>&1 | %FileCheck %s
+
+// CHECK: :1:8: error: cannot load module 'DreadPirateRoberts' as 'WrongName'

test/ModuleInterface/ModuleCache/force-module-load-mode-bad-config.swift

@@ -0,0 +1,3 @@
+// RUN: env SWIFT_FORCE_MODULE_LOADING=garbage not %target-swift-frontend -typecheck %s 2>&1 | %FileCheck %s
+
+// CHECK: error: unknown value for SWIFT_FORCE_MODULE_LOADING variable: 'garbage'

test/ModuleInterface/ModuleCache/force-module-loading-mode-archs.swift

@@ -0,0 +1,102 @@
+// RUN: %empty-directory(%t)
+
+// 1. Not finding things is okay.
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// (default)
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+
+// 2. Only interface is present.
+// RUN: %empty-directory(%t/Lib.swiftmodule)
+// RUN: cp %S/Inputs/force-module-loading-mode/Lib.swiftinterface %t/Lib.swiftmodule/%target-cpu.swiftinterface
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// (default)
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -I %t %s 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+
+// 3. Only module is present.
+// RUN: %empty-directory(%t/Lib.swiftmodule)
+// RUN: sed -e 's/FromInterface/FromSerialized/g' %S/Inputs/force-module-loading-mode/Lib.swiftinterface | %target-swift-frontend -parse-stdlib -module-cache-path %t/MCP -emit-module-path %t/Lib.swiftmodule/%target-swiftmodule-name - -module-name Lib
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=FROM-SERIALIZED %s
+// RUN: %empty-directory(%t/MCP)
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=FROM-SERIALIZED %s
+// RUN: %empty-directory(%t/MCP)
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// RUN: %empty-directory(%t/MCP)
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=FROM-SERIALIZED %s
+// RUN: %empty-directory(%t/MCP)
+// (default)
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -I %t %s 2>&1 | %FileCheck -check-prefix=FROM-SERIALIZED %s
+// RUN: %empty-directory(%t/MCP)
+
+// 4. Both are present.
+// RUN: cp %S/Inputs/force-module-loading-mode/Lib.swiftinterface %t/Lib.swiftmodule/%target-cpu.swiftinterface
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: %empty-directory(%t/MCP)
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=FROM-SERIALIZED %s
+// RUN: %empty-directory(%t/MCP)
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: %empty-directory(%t/MCP)
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=FROM-SERIALIZED %s
+// (default)
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -I %t %s 2>&1 | %FileCheck -check-prefix=FROM-SERIALIZED %s
+// RUN: %empty-directory(%t/MCP)
+
+// 5. Both are present but the module is invalid.
+// RUN: rm %t/Lib.swiftmodule/%target-swiftmodule-name && touch %t/Lib.swiftmodule/%target-swiftmodule-name
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=BAD-MODULE %s
+// (default)
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -I %t %s 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+
+// 6. Both are present but the module can't be opened.
+// RUN: %{python} %S/../Inputs/make-unreadable.py %t/Lib.swiftmodule/%target-swiftmodule-name
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: %empty-directory(%t/MCP)
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// RUN: %empty-directory(%t/MCP)
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: %empty-directory(%t/MCP)
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// RUN: %empty-directory(%t/MCP)
+// (default)
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -I %t %s 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// RUN: %empty-directory(%t/MCP)
+
+// 7. Both are present but for the wrong architecture.
+// RUN: %empty-directory(%t/Lib.swiftmodule)
+// RUN: touch %t/Lib.swiftmodule/garbage.swiftmodule
+// RUN: touch %t/Lib.swiftmodule/garbage.swiftinterface
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=WRONG-ARCH -DARCH=%module-target-triple %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=WRONG-ARCH -DARCH=%module-target-triple %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=WRONG-ARCH -DARCH=%module-target-triple %s
+// (default)
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -I %t %s 2>&1 | %FileCheck -check-prefix=WRONG-ARCH -DARCH=%module-target-triple %s
+
+// 8. Only the interface is present but for the wrong architecture.
+// (Diagnostics for the module only are tested elsewhere.)
+// FIXME: We should improve this to not just say NO-SUCH-MODULE.
+// RUN: rm %t/Lib.swiftmodule/garbage.swiftmodule
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// (default)
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -I %t %s 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+
+import Lib
+// NO-SUCH-MODULE: [[@LINE-1]]:8: error: no such module 'Lib'
+// BAD-MODULE: [[@LINE-2]]:8: error: malformed compiled module: {{.*}}Lib.swiftmodule
+// WRONG-ARCH: [[@LINE-3]]:8: error: could not find module 'Lib' for target '[[ARCH]]'; found: garbage
+
+struct X {}
+let _: X = Lib.testValue
+// FROM-INTERFACE: [[@LINE-1]]:16: error: cannot convert value of type 'FromInterface' to specified type 'X'
+// FROM-SERIALIZED: [[@LINE-2]]:16: error: cannot convert value of type 'FromSerialized' to specified type 'X'

test/ModuleInterface/ModuleCache/force-module-loading-mode-framework.swift

@@ -0,0 +1,103 @@
+// RUN: %empty-directory(%t)
+
+// 1. Not finding things is okay.
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// (default)
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+
+// 2. Only interface is present.
+// RUN: %empty-directory(%t/Lib.framework/Modules/Lib.swiftmodule)
+// RUN: cp %S/Inputs/force-module-loading-mode/Lib.swiftinterface %t/Lib.framework/Modules/Lib.swiftmodule/%target-cpu.swiftinterface
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -F %t 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -F %t 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -F %t 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -F %t 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// (default)
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -F %t %s 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+
+// 3. Only module is present.
+// RUN: %empty-directory(%t/Lib.framework/Modules/Lib.swiftmodule)
+// RUN: sed -e 's/FromInterface/FromSerialized/g' %S/Inputs/force-module-loading-mode/Lib.swiftinterface | %target-swift-frontend -parse-stdlib -module-cache-path %t/MCP -emit-module-path %t/Lib.framework/Modules/Lib.swiftmodule/%target-swiftmodule-name - -module-name Lib
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -F %t 2>&1 | %FileCheck -check-prefix=FROM-SERIALIZED %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -F %t 2>&1 | %FileCheck -check-prefix=FROM-SERIALIZED %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -F %t 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -F %t 2>&1 | %FileCheck -check-prefix=FROM-SERIALIZED %s
+// (default)
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -F %t %s 2>&1 | %FileCheck -check-prefix=FROM-SERIALIZED %s
+
+// 4. Both are present.
+// RUN: cp %S/Inputs/force-module-loading-mode/Lib.swiftinterface %t/Lib.framework/Modules/Lib.swiftmodule/%target-cpu.swiftinterface
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -F %t 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: %empty-directory(%t/MCP)
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -F %t 2>&1 | %FileCheck -check-prefix=FROM-SERIALIZED %s
+// RUN: %empty-directory(%t/MCP)
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -F %t 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: %empty-directory(%t/MCP)
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -F %t 2>&1 | %FileCheck -check-prefix=FROM-SERIALIZED %s
+// RUN: %empty-directory(%t/MCP)
+// (default)
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -F %t %s 2>&1 | %FileCheck -check-prefix=FROM-SERIALIZED %s
+// RUN: %empty-directory(%t/MCP)
+
+// 5. Both are present but the module is invalid.
+// RUN: rm %t/Lib.framework/Modules/Lib.swiftmodule/%target-swiftmodule-name && touch %t/Lib.framework/Modules/Lib.swiftmodule/%target-swiftmodule-name
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -F %t 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: %empty-directory(%t/MCP)
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -F %t 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: %empty-directory(%t/MCP)
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -F %t 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: %empty-directory(%t/MCP)
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -F %t 2>&1 | %FileCheck -check-prefix=BAD-MODULE %s
+// RUN: %empty-directory(%t/MCP)
+// (default)
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -F %t %s 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: %empty-directory(%t/MCP)
+
+// 6. Both are present but the module can't be opened.
+// RUN: %{python} %S/../Inputs/make-unreadable.py %t/Lib.framework/Modules/Lib.swiftmodule/%target-swiftmodule-name
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -F %t 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: %empty-directory(%t/MCP)
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -F %t 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// RUN: %empty-directory(%t/MCP)
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -F %t 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: %empty-directory(%t/MCP)
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -F %t 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// RUN: %empty-directory(%t/MCP)
+// (default)
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -F %t %s 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// RUN: %empty-directory(%t/MCP)
+
+// 7. Both are present but for the wrong architecture.
+// RUN: %empty-directory(%t/Lib.framework/Modules/Lib.swiftmodule)
+// RUN: touch %t/Lib.framework/Modules/Lib.swiftmodule/garbage.swiftmodule
+// RUN: touch %t/Lib.framework/Modules/Lib.swiftmodule/garbage.swiftinterface
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -F %t 2>&1 | %FileCheck -check-prefix=WRONG-ARCH -DARCH=%module-target-triple %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -F %t 2>&1 | %FileCheck -check-prefix=WRONG-ARCH -DARCH=%module-target-triple %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -F %t 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -F %t 2>&1 | %FileCheck -check-prefix=WRONG-ARCH -DARCH=%module-target-triple %s
+// (default)
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -F %t %s 2>&1 | %FileCheck -check-prefix=WRONG-ARCH -DARCH=%module-target-triple %s
+
+// 8. Only the interface is present but for the wrong architecture.
+// (Diagnostics for the module only are tested elsewhere.)
+// FIXME: We should improve this to not just say NO-SUCH-MODULE.
+// RUN: rm %t/Lib.framework/Modules/Lib.swiftmodule/garbage.swiftmodule
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -F %t 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -F %t 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -F %t 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -F %t 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// (default)
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -F %t %s 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+
+import Lib
+// NO-SUCH-MODULE: [[@LINE-1]]:8: error: no such module 'Lib'
+// BAD-MODULE: [[@LINE-2]]:8: error: malformed compiled module: {{.*}}Lib.swiftmodule
+// WRONG-ARCH: [[@LINE-3]]:8: error: could not find module 'Lib' for target '[[ARCH]]'; found: garbage
+
+struct X {}
+let _: X = Lib.testValue
+// FROM-INTERFACE: [[@LINE-1]]:16: error: cannot convert value of type 'FromInterface' to specified type 'X'
+// FROM-SERIALIZED: [[@LINE-2]]:16: error: cannot convert value of type 'FromSerialized' to specified type 'X'

test/ModuleInterface/ModuleCache/force-module-loading-mode.swift

@@ -0,0 +1,77 @@
+// RUN: %empty-directory(%t)
+
+// 1. Not finding things is okay.
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// (default)
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+
+// 2. Only interface is present.
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %S/Inputs/force-module-loading-mode/ 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %S/Inputs/force-module-loading-mode/ 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %S/Inputs/force-module-loading-mode/ 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %S/Inputs/force-module-loading-mode/ 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// (default)
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -I %S/Inputs/force-module-loading-mode/ %s 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+
+// 3. Only module is present.
+// RUN: sed -e 's/FromInterface/FromSerialized/g' %S/Inputs/force-module-loading-mode/Lib.swiftinterface | %target-swift-frontend -parse-stdlib -module-cache-path %t/MCP -emit-module-path %t/Lib.swiftmodule - -module-name Lib
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=FROM-SERIALIZED %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=FROM-SERIALIZED %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=FROM-SERIALIZED %s
+// (default)
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -I %t %s 2>&1 | %FileCheck -check-prefix=FROM-SERIALIZED %s
+
+// 4. Both are present.
+// RUN: cp %S/Inputs/force-module-loading-mode/Lib.swiftinterface %t
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: %empty-directory(%t/MCP)
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=FROM-SERIALIZED %s
+// RUN: %empty-directory(%t/MCP)
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: %empty-directory(%t/MCP)
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=FROM-SERIALIZED %s
+// RUN: %empty-directory(%t/MCP)
+// (default)
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -I %t %s 2>&1 | %FileCheck -check-prefix=FROM-SERIALIZED %s
+// RUN: %empty-directory(%t/MCP)
+
+// 5. Both are present but the module is invalid.
+// RUN: rm %t/Lib.swiftmodule && touch %t/Lib.swiftmodule
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: %empty-directory(%t/MCP)
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: %empty-directory(%t/MCP)
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: %empty-directory(%t/MCP)
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=BAD-MODULE %s
+// RUN: %empty-directory(%t/MCP)
+// (default)
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -I %t %s 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: %empty-directory(%t/MCP)
+
+// 6. Both are present but the module can't be opened.
+// RUN: %{python} %S/../Inputs/make-unreadable.py %t/Lib.swiftmodule
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: %empty-directory(%t/MCP)
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// RUN: %empty-directory(%t/MCP)
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-parseable not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: %empty-directory(%t/MCP)
+// RUN: env SWIFT_FORCE_MODULE_LOADING=only-serialized not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP %s -I %t 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// RUN: %empty-directory(%t/MCP)
+// (default)
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -I %t %s 2>&1 | %FileCheck -check-prefix=NO-SUCH-MODULE %s
+// RUN: %empty-directory(%t/MCP)
+
+import Lib
+// NO-SUCH-MODULE: [[@LINE-1]]:8: error: no such module 'Lib'
+// BAD-MODULE: [[@LINE-2]]:8: error: malformed compiled module: {{.*}}Lib.swiftmodule
+
+struct X {}
+let _: X = Lib.testValue
+// FROM-INTERFACE: [[@LINE-1]]:16: error: cannot convert value of type 'FromInterface' to specified type 'X'
+// FROM-SERIALIZED: [[@LINE-2]]:16: error: cannot convert value of type 'FromSerialized' to specified type 'X'

test/ModuleInterface/ModuleCache/forwarding-module-dependencies.swift

@@ -0,0 +1,56 @@
+// RUN: %empty-directory(%t)
+// RUN: %empty-directory(%t/mock-sdk)
+// RUN: %empty-directory(%t/ModuleCache)
+// RUN: %empty-directory(%t/PrebuiltModuleCache)
+
+// This test makes sure that we propagate the right set of dependencies from a
+// prebuilt module to its corresponding forwarding module.
+
+// Setup. Copy the mock SDK into the tmp directory.
+// RUN: cp -r %S/Inputs/mock-sdk/* %t/mock-sdk/.
+
+// 1. Compile ExportedLib.swiftinterface, which a) is in the SDK, and b) depends
+//    on a C module with headers that should be in the dependency list.
+//    Put it in the prebuilt cache.
+
+// RUN: %target-swift-frontend -compile-module-from-interface %t/mock-sdk/ExportedLib.swiftinterface -sdk %t/mock-sdk -o %t/PrebuiltModuleCache/ExportedLib.swiftmodule -serialize-parseable-module-interface-dependency-hashes -track-system-dependencies
+
+// 2. Make sure the prebuilt module we built has SomeCModule.h as a dependency.
+
+// RUN: llvm-bcanalyzer -dump %t/PrebuiltModuleCache/ExportedLib.swiftmodule | grep 'FILE_DEPENDENCY.*SomeCModule.h'
+
+// 3. Typecheck this file, which imports SdkLib, which imports ExportedLib.
+//    Because ExportedLib is prebuilt, we expect a forwarding module for
+//    ExportedLib in the module cache, and a serialized module for SdkLib in
+//    the cache.
+
+// RUN: %target-swift-frontend -typecheck %s -prebuilt-module-cache-path %t/PrebuiltModuleCache -module-cache-path %t/ModuleCache -sdk %t/mock-sdk -I %t/mock-sdk -track-system-dependencies
+
+// 4. Make sure the forwarding module is installed in the cache.
+
+// RUN: %{python} %S/Inputs/check-is-forwarding-module.py %t/ModuleCache/ExportedLib-*.swiftmodule
+
+// 5. Make sure the forwarding module depends on the prebuilt module and the C
+//    header.
+
+// RUN: grep '  *path:.*ExportedLib.swiftmodule' %t/ModuleCache/ExportedLib-*.swiftmodule
+// RUN: grep '  *path:.*SomeCModule.h' %t/ModuleCache/ExportedLib-*.swiftmodule
+
+// 6. Make sure the dependencies from the forwarding module make it into the
+//    cached module.
+
+// RUN: llvm-bcanalyzer -dump %t/ModuleCache/SdkLib-*.swiftmodule | grep 'FILE_DEPENDENCY.*SomeCModule.h'
+
+// 7. Make sure the prebuilt ExportedLib module did NOT get propagated to SdkLib.
+
+// RUN: llvm-bcanalyzer -dump %t/ModuleCache/SdkLib-*.swiftmodule | not grep 'FILE_DEPENDENCY.*PrebuiltModuleCache'
+
+// 8. Make sure we re-build the SdkLib module if one of the dependencies changes its mtime (but not its hash).
+//    This will ensure we recorded the forwarding module's dependencies, not the prebuilt.
+
+// RUN: %{python} %S/Inputs/make-old.py %t/ModuleCache/SdkLib-*.swiftmodule
+// RUN: %{python} %S/Inputs/make-old.py %t/mock-sdk/usr/include/SomeCModule.h
+// RUN: %target-swift-frontend -typecheck %s -prebuilt-module-cache-path %t/PrebuiltModuleCache -module-cache-path %t/ModuleCache -sdk %t/mock-sdk -I %t/mock-sdk -track-system-dependencies
+// RUN: %{python} %S/Inputs/check-is-new.py %t/ModuleCache/SdkLib-*.swiftmodule
+
+import SdkLib

test/ModuleInterface/ModuleCache/module-cache-bad-version.swift

@@ -0,0 +1,32 @@
+// RUN: %empty-directory(%t)
+// RUN: %empty-directory(%t/modulecache)
+//
+// Test will build a module TestModule that depends LeafModule (built from leaf.swift).
+//
+// RUN: echo 'public func LeafFunc() -> Int { return 10; }' >%t/leaf.swift
+//
+// RUN: %target-swift-frontend -I %t -emit-module-interface-path %t/LeafModule.swiftinterface -module-name LeafModule %t/leaf.swift -emit-module -o /dev/null
+// RUN: test -f %t/LeafModule.swiftinterface
+// RUN: %FileCheck %s -check-prefix=CHECK-LEAFINTERFACE <%t/LeafModule.swiftinterface
+// CHECK-LEAFINTERFACE: {{swift-interface-format-version: [0-9\\.]+}}
+// CHECK-LEAFINTERFACE: LeafFunc
+//
+// Break LeafModule's version number
+// RUN: sed -e 's/swift-interface-format-version:.*/swift-interface-format-version: 9999.999/' %t/LeafModule.swiftinterface | tr -d '\r' > %t/LeafModule.swiftinterface.tmp
+// RUN: mv %t/LeafModule.swiftinterface.tmp %t/LeafModule.swiftinterface
+//
+// Try to build TestModule into a .swiftmodule explicitly using LeafModule via LeafModule.swiftinterface, but fail because version mismatch in LeafModule.swiftinterface.
+//
+// RUN: not %target-swift-frontend -I %t -module-cache-path %t/modulecache -emit-module  -o %t/TestModule.swiftmodule -module-name TestModule %s >%t/err.txt 2>&1
+// RUN: test ! -f %t/TestModule.swiftmodule
+// This avoids a problem in Windows with test ! -f 'foo*' for a file that doesn't exist
+// RUN: %{python} -c "import sys; import glob; sys.exit(len(glob.glob('%t/modulecache/LeafModule-*.swiftmodule')) != 0)"
+// RUN: %FileCheck %s -check-prefix=CHECK-ERR <%t/err.txt
+// CHECK-ERR: {{error: unsupported version of module interface '.*[/\\]LeafModule.swiftinterface': '9999.999'}}
+// CHECK-ERR: error: no such module 'LeafModule
+
+import LeafModule
+
+public func TestFunc() {
+    print(LeafFunc())
+}

test/ModuleInterface/ModuleCache/module-cache-deployment-target-irrelevant.swift

@@ -0,0 +1,32 @@
+// This test specifically uses macOS deployment targets
+// REQUIRES: OS=macosx
+//
+// RUN: %empty-directory(%t)
+//
+// Test will build a module TestModule that depends on OtherModule and LeafModule (built from other.swift and leaf.swift).
+//
+// RUN: echo 'public func LeafFunc() -> Int { return 10; }' >%t/leaf.swift
+//
+// RUN: echo 'import LeafModule' >%t/other.swift
+// RUN: echo 'public func OtherFunc() -> Int { return LeafFunc(); }' >>%t/other.swift
+//
+// Phase 1: build LeafModule into a .swiftinterface file with -target x86_64-macosx-10.9:
+//
+// RUN: %swift -target x86_64-apple-macosx10.9 -I %t -module-cache-path %t/modulecache -emit-module-interface-path %t/LeafModule.swiftinterface -module-name LeafModule %t/leaf.swift -typecheck
+//
+// Phase 2: build OtherModule into a .swiftinterface file with -target x86_64-macosx-10.10:
+//
+// RUN: %swift -target x86_64-apple-macosx10.10 -I %t -module-cache-path %t/modulecache -emit-module-interface-path %t/OtherModule.swiftinterface -module-name OtherModule %t/other.swift -typecheck
+//
+// Phase 3: build TestModule in -target x86_64-apple-macosx10.11 and import both of these:
+//
+// RUN: %swift -target x86_64-apple-macosx10.11  -I %t -module-cache-path %t/modulecache -module-name TestModule %s -typecheck
+//
+// Phase 4: make sure we only compiled LeafModule and OtherModule one time:
+//
+// RUN: NUM_LEAF_MODULES=$(find %t/modulecache -type f -name 'LeafModule-*.swiftmodule' | wc -l)
+// RUN: NUM_OTHER_MODULES=$(find %t/modulecache -type f -name 'OtherModule-*.swiftmodule' | wc -l)
+// RUN: if [ ! $NUM_LEAF_MODULES -eq 1 ]; then echo "Should only be 1 LeafModule, found $NUM_LEAF_MODULES"; exit 1; fi
+// RUN: if [ ! $NUM_OTHER_MODULES -eq 1 ]; then echo "Should only be 1 OtherModule, found $NUM_OTHER_MODULES"; exit 1; fi
+import LeafModule
+import OtherModule

test/ModuleInterface/ModuleCache/module-cache-diagnostics.swift

@@ -0,0 +1,103 @@
+// RUN: %empty-directory(%t)
+// RUN: %empty-directory(%t/modulecache)
+//
+// Setup builds a module TestModule that depends on OtherModule and LeafModule (built from other.swift and leaf.swift).
+// During setup, input and intermediate mtimes are all set to a constant 'old' time (long in the past).
+//
+// We then revert LeafModule.swiftinterface to have a warning-provoking entry in it, and check that we get no diagnostic.
+//
+// We then modify LeafModule.swiftinterface to have an error in it, and check that we get a diagnostic and failure.
+//
+// We then modify LeafModule.swiftinterface to have an error in an @inlinable function body, and check we get a diagnostic and failure.
+//
+// Setup phase 1: Write input files.
+//
+// RUN: echo 'public func LeafFunc() -> Int { return 10; }' >%t/leaf.swift
+//
+// RUN: echo 'import LeafModule' >%t/other.swift
+// RUN: echo 'public func OtherFunc() -> Int { return LeafFunc(); }' >>%t/other.swift
+//
+//
+// Setup phase 2: build modules, pushing timestamps of inputs and intermediates into the past as we go.
+//
+// RUN: %{python} %S/Inputs/make-old.py %t/leaf.swift %t/other.swift
+// RUN: %target-swift-frontend -I %t -emit-module-interface-path %t/LeafModule.swiftinterface -module-name LeafModule %t/leaf.swift -emit-module -o /dev/null
+// RUN: %{python} %S/Inputs/make-old.py %t/LeafModule.swiftinterface
+// RUN: %target-swift-frontend -I %t -module-cache-path %t/modulecache -emit-module-interface-path %t/OtherModule.swiftinterface -module-name OtherModule %t/other.swift -emit-module -o /dev/null
+// RUN: %{python} %S/Inputs/make-old.py %t/modulecache/LeafModule-*.swiftmodule %t/OtherModule.swiftinterface
+// RUN: %target-swift-frontend -I %t -module-cache-path %t/modulecache -emit-module -o %t/TestModule.swiftmodule -module-name TestModule %s
+// RUN: %{python} %S/Inputs/make-old.py %t/modulecache/OtherModule-*.swiftmodule
+//
+//
+// Actual test: add an inlinable func with an unused var to LeafModule.swiftinterface (which should emit a warning); check we do get a rebuild, but no warning. (For astooscopelookup testing, must filter out that warning; see the sed command below.)
+//
+// RUN: %{python} %S/Inputs/check-is-old.py %t/OtherModule.swiftinterface %t/LeafModule.swiftinterface
+// RUN: %{python} %S/Inputs/check-is-old.py %t/modulecache/OtherModule-*.swiftmodule %t/modulecache/LeafModule-*.swiftmodule
+// RUN: cp %t/LeafModule.swiftinterface %t/LeafModule.swiftinterface.backup
+// RUN: echo "@inlinable func foo() { var x = 10 }" >>%t/LeafModule.swiftinterface
+// RUN: %{python} %S/Inputs/make-old.py %t/LeafModule.swiftinterface
+// RUN: %{python} %S/Inputs/check-is-old.py %t/LeafModule.swiftinterface
+// RUN: rm %t/TestModule.swiftmodule
+// RUN: %target-swift-frontend -I %t -module-cache-path %t/modulecache -emit-module -o %t/TestModule.swiftmodule -module-name TestModule %s  2>&1 | sed '/WARNING: TRYING Scope exclusively/d' >%t/warn.txt
+// RUN: %{python} %S/Inputs/check-is-new.py %t/modulecache/OtherModule-*.swiftmodule %t/modulecache/LeafModule-*.swiftmodule
+// "check warn.txt exists and is empty"
+// RUN: test -e %t/warn.txt -a ! -s %t/warn.txt
+//
+//
+// Next test: make LeafModule.swiftinterface import NotAModule (which should emit an error); check we do not get a rebuild, do get an error.
+//
+// RUN: %{python} %S/Inputs/make-old.py %t/modulecache/*.swiftmodule %t/*.swiftinterface
+// RUN: %{python} %S/Inputs/check-is-old.py %t/OtherModule.swiftinterface %t/LeafModule.swiftinterface
+// RUN: %{python} %S/Inputs/check-is-old.py %t/modulecache/OtherModule-*.swiftmodule %t/modulecache/LeafModule-*.swiftmodule
+// RUN: echo "import NotAModule" >>%t/LeafModule.swiftinterface
+// RUN: %{python} %S/Inputs/make-old.py %t/LeafModule.swiftinterface
+// RUN: %{python} %S/Inputs/check-is-old.py %t/LeafModule.swiftinterface
+// RUN: rm %t/TestModule.swiftmodule
+// RUN: not %target-swift-frontend -I %t -module-cache-path %t/modulecache -emit-module -o %t/TestModule.swiftmodule -module-name TestModule %s >%t/err.txt 2>&1
+// RUN: %{python} %S/Inputs/check-is-old.py %t/modulecache/OtherModule-*.swiftmodule %t/modulecache/LeafModule-*.swiftmodule
+// RUN: %FileCheck %s -check-prefix=CHECK-ERROR <%t/err.txt
+// CHECK-ERROR: LeafModule.swiftinterface:7:8: error: no such module 'NotAModule'
+// CHECK-ERROR: OtherModule.swiftinterface:4:8: error: failed to load module 'LeafModule'
+// CHECK-ERROR: module-cache-diagnostics.swift:{{[0-9]+}}:8: error: failed to load module 'OtherModule'
+// CHECK-ERROR-NOT: error:
+//
+//
+// Next test: same as above, but with a .dia file
+//
+// RUN: %{python} %S/Inputs/check-is-old.py %t/OtherModule.swiftinterface %t/LeafModule.swiftinterface
+// RUN: %{python} %S/Inputs/check-is-old.py %t/modulecache/OtherModule-*.swiftmodule %t/modulecache/LeafModule-*.swiftmodule
+// RUN: not %target-swift-frontend -I %t -module-cache-path %t/modulecache -serialize-diagnostics -serialize-diagnostics-path %t/err.dia -emit-module -o %t/TestModule.swiftmodule -module-name TestModule %s
+// RUN: %{python} %S/Inputs/check-is-old.py %t/modulecache/OtherModule-*.swiftmodule %t/modulecache/LeafModule-*.swiftmodule
+// RUN: c-index-test -read-diagnostics %t/err.dia 2>&1 | %FileCheck %s -check-prefix=CHECK-ERROR
+//
+//
+// Next test: add an inlinable function body with an unresolved identifier to LeafModule.swiftinterface; check we do not get a rebuild and report the additional error correctly.
+//
+// RUN: mv %t/LeafModule.swiftinterface.backup %t/LeafModule.swiftinterface
+// RUN: echo "@inlinable func bar() { var x = unresolved }" >>%t/LeafModule.swiftinterface
+// RUN: %{python} %S/Inputs/make-old.py %t/LeafModule.swiftinterface
+// RUN: %{python} %S/Inputs/check-is-old.py %t/OtherModule.swiftinterface %t/LeafModule.swiftinterface
+// RUN: %{python} %S/Inputs/check-is-old.py %t/modulecache/OtherModule-*.swiftmodule %t/modulecache/LeafModule-*.swiftmodule
+// RUN: not %target-swift-frontend -I %t -module-cache-path %t/modulecache -emit-module -o %t/TestModule.swiftmodule -module-name TestModule %s >%t/err-inline.txt 2>&1
+// RUN: %{python} %S/Inputs/check-is-old.py %t/modulecache/OtherModule-*.swiftmodule %t/modulecache/LeafModule-*.swiftmodule
+// RUN: %FileCheck %s -check-prefix=CHECK-ERROR-INLINE <%t/err-inline.txt
+// CHECK-ERROR-INLINE: LeafModule.swiftinterface:6:33: error: use of unresolved identifier 'unresolved'
+// CHECK-ERROR-INLINE: OtherModule.swiftinterface:4:8: error: failed to load module 'LeafModule'
+// CHECK-ERROR-INLINE: module-cache-diagnostics.swift:{{[0-9]+}}:8: error: failed to load module 'OtherModule'
+// CHECK-ERROR-INLINE-NOT: error:
+//
+//
+// Next test: same as above, but with a .dia file
+//
+// RUN: %{python} %S/Inputs/check-is-old.py %t/OtherModule.swiftinterface %t/LeafModule.swiftinterface
+// RUN: %{python} %S/Inputs/check-is-old.py %t/modulecache/OtherModule-*.swiftmodule %t/modulecache/LeafModule-*.swiftmodule
+// RUN: not %target-swift-frontend -I %t -module-cache-path %t/modulecache -serialize-diagnostics -serialize-diagnostics-path %t/err-inline.dia -emit-module -o %t/TestModule.swiftmodule -module-name TestModule %s
+// RUN: %{python} %S/Inputs/check-is-old.py %t/modulecache/OtherModule-*.swiftmodule %t/modulecache/LeafModule-*.swiftmodule
+// RUN: c-index-test -read-diagnostics %t/err-inline.dia 2>&1 | %FileCheck %s -check-prefix=CHECK-ERROR-INLINE
+
+import OtherModule
+
+public func TestFunc() {
+    print(OtherFunc())
+}
+

test/ModuleInterface/ModuleCache/module-cache-effective-version-irrelevant.swift

@@ -0,0 +1,29 @@
+// RUN: %empty-directory(%t)
+//
+// Test will build a module TestModule that depends on OtherModule and LeafModule (built from other.swift and leaf.swift).
+//
+// RUN: echo 'public func LeafFunc() -> Int { return 10; }' >%t/leaf.swift
+//
+// RUN: echo 'import LeafModule' >%t/other.swift
+// RUN: echo 'public func OtherFunc() -> Int { return LeafFunc(); }' >>%t/other.swift
+//
+// Phase 1: build LeafModule into a .swiftinterface file with -swift-version 4:
+//
+// RUN: %target-swift-frontend -swift-version 4 -I %t -module-cache-path %t/modulecache -emit-module-interface-path %t/LeafModule.swiftinterface -module-name LeafModule %t/leaf.swift -typecheck
+//
+// Phase 2: build OtherModule into a .swiftinterface file with -swift-version 4.2:
+//
+// RUN: %target-swift-frontend -swift-version 4.2 -I %t -module-cache-path %t/modulecache -emit-module-interface-path %t/OtherModule.swiftinterface -module-name OtherModule %t/other.swift -typecheck
+//
+// Phase 3: build TestModule in -swift-version 5 and import both of these:
+//
+// RUN: %target-swift-frontend -swift-version 5 -I %t -module-cache-path %t/modulecache -module-name TestModule %s -typecheck
+//
+// Phase 4: make sure we only compiled LeafModule and OtherModule one time:
+//
+// RUN: ls %t/modulecache | grep -c 'LeafModule-.*.swiftmodule' | %FileCheck %s
+// RUN: ls %t/modulecache | grep -c 'OtherModule-.*.swiftmodule' | %FileCheck %s
+// CHECK: 1
+
+import LeafModule
+import OtherModule

test/ModuleInterface/ModuleCache/module-cache-errors-in-importing-file.swift

@@ -0,0 +1,23 @@
+// RUN: %empty-directory(%t)
+// RUN: %empty-directory(%t/modulecache)
+//
+// Setup builds a parseable interface for a module SomeModule (built from some-module.swift).
+// This test checks we still build and load its corresponding .swiftmodule when the file that imports it contains an error prior to the import statement.
+
+// Setup phase 1: Write the input file.
+//
+// RUN: echo 'public func SomeFunc() -> Int { return 42; }' >>%t/some-module.swift
+
+// Setup phase 2: build the module.
+//
+// RUN: %target-swift-frontend -I %t -emit-module-interface-path %t/SomeModule.swiftinterface -module-name SomeModule %t/some-module.swift -emit-module -o /dev/null
+
+// Actual test: compile and verify the import succeeds (i.e. we only report the error in this file)
+//
+// RUN: %target-swift-frontend -typecheck -verify -I %t -module-cache-path %t/modulecache %s
+
+unresolved // expected-error {{use of unresolved identifier 'unresolved'}}
+
+import SomeModule
+
+print(SomeFunc())

test/ModuleInterface/ModuleCache/module-cache-init.swift

@@ -0,0 +1,72 @@
+// RUN: %empty-directory(%t)
+//
+// Test will build a module TestModule that depends on OtherModule and LeafModule (built from other.swift and leaf.swift).
+//
+// RUN: echo 'public func LeafFunc() -> Int { return 10; }' >%t/leaf.swift
+//
+// RUN: echo 'import LeafModule' >%t/other.swift
+// RUN: echo 'public func OtherFunc() -> Int { return LeafFunc(); }' >>%t/other.swift
+//
+// Phase 1: build LeafModule into a .swiftinterface file:
+//
+// RUN: %target-swift-frontend -I %t -emit-module-interface-path %t/LeafModule.swiftinterface -module-name LeafModule %t/leaf.swift -emit-module -o /dev/null
+// RUN: test -f %t/LeafModule.swiftinterface
+// RUN: %FileCheck %s -check-prefix=CHECK-LEAFINTERFACE <%t/LeafModule.swiftinterface
+// CHECK-LEAFINTERFACE: LeafFunc
+//
+//
+// Phase 2: build OtherModule into a .swiftinterface _using_ LeafModule via LeafModule.swiftinterface, creating LeafModule-*.swiftmodule along the way.
+//
+// RUN: %target-swift-frontend -I %t -module-cache-path %t/modulecache -emit-module-interface-path %t/OtherModule.swiftinterface -module-name OtherModule %t/other.swift -emit-module -o /dev/null
+// RUN: test -f %t/OtherModule.swiftinterface
+// RUN: %FileCheck %s -check-prefix=CHECK-OTHERINTERFACE <%t/OtherModule.swiftinterface
+// CHECK-OTHERINTERFACE: OtherFunc
+// RUN: test -f %t/modulecache/LeafModule-*.swiftmodule
+// RUN: llvm-bcanalyzer -dump %t/modulecache/LeafModule-*.swiftmodule | %FileCheck %s -check-prefix=CHECK-LEAFMODULE
+// CHECK-LEAFMODULE: {{MODULE_NAME.*blob data = 'LeafModule'}}
+// CHECK-LEAFMODULE: {{FILE_DEPENDENCY.*LeafModule.swiftinterface'}}
+// CHECK-LEAFMODULE: FUNC_DECL
+// RUN: llvm-bcanalyzer -dump %t/modulecache/LeafModule-*.swiftmodule | %FileCheck %s -check-prefix=CHECK-LEAFMODULE-NEGATIVE
+// CHECK-LEAFMODULE-NEGATIVE-NOT: {{FILE_DEPENDENCY.*Swift.swiftmodule([/\\].+[.]swiftmodule)?'}}
+//
+//
+// Phase 3: build TestModule into a .swiftmodule explicitly us OtherModule via OtherModule.swiftinterface, creating OtherModule-*.swiftmodule along the way.
+//
+// RUN: %target-swift-frontend -I %t -module-cache-path %t/modulecache -emit-module -emit-dependencies -emit-dependencies-path %t/TestModule.d -o %t/TestModule.swiftmodule -module-name TestModule %s
+// RUN: test -f %t/TestModule.swiftmodule
+// RUN: test -f %t/modulecache/OtherModule-*.swiftmodule
+// RUN: test -f %t/TestModule.d
+// RUN: llvm-bcanalyzer -dump %t/modulecache/OtherModule-*.swiftmodule | %FileCheck %s -check-prefix=CHECK-OTHERMODULE
+// CHECK-OTHERMODULE: {{MODULE_NAME.*blob data = 'OtherModule'}}
+// CHECK-OTHERMODULE-NOT: {{FILE_DEPENDENCY.*Swift.swiftmodule([/\\].+[.]swiftmodule)?'}}
+// CHECK-OTHERMODULE: {{FILE_DEPENDENCY.*LeafModule.swiftinterface'}}
+// CHECK-OTHERMODULE: {{FILE_DEPENDENCY.*OtherModule.swiftinterface'}}
+// CHECK-OTHERMODULE: FUNC_DECL
+//
+// Quirk: because the cached .swiftmodules have a hash name component that
+// integrates target, and we sort the contents of lines in a .d file by the
+// dependency's reverse-name (for reasons), the order in which the cached
+// .swiftmodules are listed in the .d file will vary _by target_.
+//
+// So we cannot write a single set of CHECK-SAME lines here that will work
+// for all targets: some will have LeafModule first, some OtherModule
+// first. So instead we just use CHECK-DAG.
+//
+// RUN: %FileCheck %s -check-prefix=CHECK-DEPENDS <%t/TestModule.d
+//
+// CHECK-DEPENDS: TestModule.swiftmodule :
+// CHECK-DEPENDS-DAG: LeafModule.swiftinterface
+// CHECK-DEPENDS-DAG: OtherModule.swiftinterface
+// CHECK-DEPENDS-DAG: Swift.swiftmodule
+// CHECK-DEPENDS-DAG: SwiftOnoneSupport.swiftmodule
+//
+// RUN: %FileCheck %s -check-prefix=CHECK-DEPENDS-NEGATIVE <%t/TestModule.d
+//
+// CHECK-DEPENDS-NEGATIVE-NOT: {{LeafModule-[^ ]+.swiftmodule}}
+// CHECK-DEPENDS-NEGATIVE-NOT: {{OtherModule-[^ ]+.swiftmodule}}
+
+import OtherModule
+
+public func TestFunc() {
+    print(OtherFunc())
+}

test/ModuleInterface/ModuleCache/module-cache-intermediate-mtime-change-rebuilds-only-intermediate.swift

@@ -0,0 +1,44 @@
+// RUN: %empty-directory(%t)
+// RUN: %empty-directory(%t/modulecache)
+//
+// Setup builds a module TestModule that depends on OtherModule and LeafModule (built from other.swift and leaf.swift).
+// During setup, input and intermediate mtimes are all set to a constant 'old' time (long in the past).
+//
+// We then modify OtherModule.swiftinterface's content (but not size), and check only OtherModule-*.swiftmodule has a new mtime, LeafModule is unchanged.
+//
+//
+// Setup phase 1: Write input files.
+//
+// RUN: echo 'public func LeafFunc() -> Int { return 10; }' >%t/leaf.swift
+//
+// RUN: echo 'import LeafModule' >%t/other.swift
+// RUN: echo 'public func OtherFunc() -> Int { return LeafFunc(); }' >>%t/other.swift
+// RUN: echo 'public func OtherFunc2() -> Int { return LeafFunc(); }' >>%t/other.swift
+//
+//
+// Setup phase 2: build modules, pushing timestamps of inputs and intermediates into the past as we go.
+//
+// RUN: %{python} %S/Inputs/make-old.py %t/leaf.swift %t/other.swift
+// RUN: %target-swift-frontend -I %t -emit-module-interface-path %t/LeafModule.swiftinterface -module-name LeafModule %t/leaf.swift -emit-module -o /dev/null
+// RUN: %{python} %S/Inputs/make-old.py %t/LeafModule.swiftinterface
+// RUN: %target-swift-frontend -I %t -module-cache-path %t/modulecache -emit-module-interface-path %t/OtherModule.swiftinterface -module-name OtherModule %t/other.swift -emit-module -o /dev/null
+// RUN: %{python} %S/Inputs/make-old.py %t/modulecache/LeafModule-*.swiftmodule %t/OtherModule.swiftinterface
+// RUN: %target-swift-frontend -I %t -module-cache-path %t/modulecache -emit-module -o %t/TestModule.swiftmodule -module-name TestModule %s
+// RUN: %{python} %S/Inputs/make-old.py %t/modulecache/OtherModule-*.swiftmodule
+//
+//
+// Actual test: Change the mtime of OtherModule.swiftinterface, check we only rebuild its cached module.
+//
+// RUN: %{python} %S/Inputs/check-is-old.py %t/OtherModule.swiftinterface %t/LeafModule.swiftinterface
+// RUN: %{python} %S/Inputs/check-is-old.py %t/modulecache/OtherModule-*.swiftmodule %t/modulecache/LeafModule-*.swiftmodule
+// RUN: touch %t/OtherModule.swiftinterface
+// RUN: rm %t/TestModule.swiftmodule
+// RUN: %target-swift-frontend -I %t -module-cache-path %t/modulecache -emit-module -o %t/TestModule.swiftmodule -module-name TestModule %s
+// RUN: %{python} %S/Inputs/check-is-new.py %t/modulecache/OtherModule-*.swiftmodule
+// RUN: %{python} %S/Inputs/check-is-old.py %t/modulecache/LeafModule-*.swiftmodule
+
+import OtherModule
+
+public func TestFunc() {
+    print(OtherFunc())
+}

test/ModuleInterface/ModuleCache/module-cache-intermediate-size-change-rebuilds-only-intermediate.swift

@@ -0,0 +1,45 @@
+// RUN: %empty-directory(%t)
+// RUN: %empty-directory(%t/modulecache)
+//
+// Setup builds a module TestModule that depends on OtherModule and LeafModule (built from other.swift and leaf.swift).
+// During setup, input and intermediate mtimes are all set to a constant 'old' time (long in the past).
+//
+// We then modify OtherModule.swiftinterface's size (but not mtime), and check only OtherModule-*.swiftmodule has a new mtime, LeafModule is unchanged.
+//
+//
+// Setup phase 1: Write input files.
+//
+// RUN: echo 'public func LeafFunc() -> Int { return 10; }' >%t/leaf.swift
+//
+// RUN: echo 'import LeafModule' >%t/other.swift
+// RUN: echo 'public func OtherFunc() -> Int { return LeafFunc(); }' >>%t/other.swift
+//
+//
+// Setup phase 2: build modules, pushing timestamps of inputs and intermediates into the past as we go.
+//
+// RUN: %{python} %S/Inputs/make-old.py %t/leaf.swift %t/other.swift
+// RUN: %target-swift-frontend -I %t -emit-module-interface-path %t/LeafModule.swiftinterface -module-name LeafModule %t/leaf.swift -emit-module -o /dev/null
+// RUN: %{python} %S/Inputs/make-old.py %t/LeafModule.swiftinterface
+// RUN: %target-swift-frontend -I %t -module-cache-path %t/modulecache -emit-module-interface-path %t/OtherModule.swiftinterface -module-name OtherModule %t/other.swift -emit-module -o /dev/null
+// RUN: %{python} %S/Inputs/make-old.py %t/modulecache/LeafModule-*.swiftmodule %t/OtherModule.swiftinterface
+// RUN: %target-swift-frontend -I %t -module-cache-path %t/modulecache -emit-module -o %t/TestModule.swiftmodule -module-name TestModule %s
+// RUN: %{python} %S/Inputs/make-old.py %t/modulecache/OtherModule-*.swiftmodule
+//
+//
+// Actual test: make OtherModule.swiftinterface change size without changing mtime, check we only rebuild its cached module.
+//
+// RUN: %{python} %S/Inputs/check-is-old.py %t/OtherModule.swiftinterface %t/LeafModule.swiftinterface
+// RUN: %{python} %S/Inputs/check-is-old.py %t/modulecache/OtherModule-*.swiftmodule %t/modulecache/LeafModule-*.swiftmodule
+// RUN: echo "// size change" >>%t/OtherModule.swiftinterface
+// RUN: %{python} %S/Inputs/make-old.py %t/OtherModule.swiftinterface
+// RUN: %{python} %S/Inputs/check-is-old.py %t/OtherModule.swiftinterface
+// RUN: rm %t/TestModule.swiftmodule
+// RUN: %target-swift-frontend -I %t -module-cache-path %t/modulecache -emit-module -o %t/TestModule.swiftmodule -module-name TestModule %s
+// RUN: %{python} %S/Inputs/check-is-new.py %t/modulecache/OtherModule-*.swiftmodule
+// RUN: %{python} %S/Inputs/check-is-old.py %t/modulecache/LeafModule-*.swiftmodule
+
+import OtherModule
+
+public func TestFunc() {
+    print(OtherFunc())
+}

test/ModuleInterface/ModuleCache/module-cache-leaf-mtime-change-rebuilds-all.swift

@@ -0,0 +1,43 @@
+// RUN: %empty-directory(%t)
+// RUN: %empty-directory(%t/modulecache)
+//
+// Setup builds a module TestModule that depends on OtherModule and LeafModule (built from other.swift and leaf.swift).
+// During setup, input and intermediate mtimes are all set to a constant 'old' time (long in the past).
+//
+// We then modify LeafModule.swiftinterface's content (but not size), and check both cached modules have new mtimes.
+//
+//
+// Setup phase 1: Write input files.
+//
+// RUN: echo 'public func LeafFunc() -> Int { return 10; }' >%t/leaf.swift
+// RUN: echo 'public func LeafFunc2() -> Int { return 11; }' >>%t/leaf.swift
+//
+// RUN: echo 'import LeafModule' >%t/other.swift
+// RUN: echo 'public func OtherFunc() -> Int { return LeafFunc(); }' >>%t/other.swift
+//
+//
+// Setup phase 2: build modules, pushing timestamps of inputs and intermediates into the past as we go.
+//
+// RUN: %{python} %S/Inputs/make-old.py %t/leaf.swift %t/other.swift
+// RUN: %target-swift-frontend -I %t -emit-module-interface-path %t/LeafModule.swiftinterface -module-name LeafModule %t/leaf.swift -emit-module -o /dev/null
+// RUN: %{python} %S/Inputs/make-old.py %t/LeafModule.swiftinterface
+// RUN: %target-swift-frontend -I %t -module-cache-path %t/modulecache -emit-module-interface-path %t/OtherModule.swiftinterface -module-name OtherModule %t/other.swift -emit-module -o /dev/null
+// RUN: %{python} %S/Inputs/make-old.py %t/modulecache/LeafModule-*.swiftmodule %t/OtherModule.swiftinterface
+// RUN: %target-swift-frontend -I %t -module-cache-path %t/modulecache -emit-module -o %t/TestModule.swiftmodule -module-name TestModule %s
+// RUN: %{python} %S/Inputs/make-old.py %t/modulecache/OtherModule-*.swiftmodule
+//
+//
+// Actual test: Change the mtime of LeafModule.swiftinterface, check both cached modules get rebuilt.
+//
+// RUN: %{python} %S/Inputs/check-is-old.py %t/OtherModule.swiftinterface %t/LeafModule.swiftinterface
+// RUN: %{python} %S/Inputs/check-is-old.py %t/modulecache/OtherModule-*.swiftmodule %t/modulecache/LeafModule-*.swiftmodule
+// RUN: touch %t/LeafModule.swiftinterface
+// RUN: rm %t/TestModule.swiftmodule
+// RUN: %target-swift-frontend -I %t -module-cache-path %t/modulecache -emit-module -o %t/TestModule.swiftmodule -module-name TestModule %s
+// RUN: %{python} %S/Inputs/check-is-new.py %t/modulecache/OtherModule-*.swiftmodule %t/modulecache/LeafModule-*.swiftmodule
+
+import OtherModule
+
+public func TestFunc() {
+    print(OtherFunc())
+}

test/ModuleInterface/ModuleCache/module-cache-leaf-size-change-rebuilds-all.swift

@@ -0,0 +1,44 @@
+// RUN: %empty-directory(%t)
+// RUN: %empty-directory(%t/modulecache)
+//
+// Setup builds a module TestModule that depends on OtherModule and LeafModule (built from other.swift and leaf.swift).
+// During setup, input and intermediate mtimes are all set to a constant 'old' time (long in the past).
+//
+// We then modify LeafModule.swiftinterface's size (but not mtime), and check both cached modules have new mtimes.
+//
+//
+// Setup phase 1: Write input files.
+//
+// RUN: echo 'public func LeafFunc() -> Int { return 10; }' >%t/leaf.swift
+//
+// RUN: echo 'import LeafModule' >%t/other.swift
+// RUN: echo 'public func OtherFunc() -> Int { return LeafFunc(); }' >>%t/other.swift
+//
+//
+// Setup phase 2: build modules, pushing timestamps of inputs and intermediates into the past as we go.
+//
+// RUN: %{python} %S/Inputs/make-old.py %t/leaf.swift %t/other.swift
+// RUN: %target-swift-frontend -I %t -emit-module-interface-path %t/LeafModule.swiftinterface -module-name LeafModule %t/leaf.swift -emit-module -o /dev/null
+// RUN: %{python} %S/Inputs/make-old.py %t/LeafModule.swiftinterface
+// RUN: %target-swift-frontend -I %t -module-cache-path %t/modulecache -emit-module-interface-path %t/OtherModule.swiftinterface -module-name OtherModule %t/other.swift -emit-module -o /dev/null
+// RUN: %{python} %S/Inputs/make-old.py %t/modulecache/LeafModule-*.swiftmodule %t/OtherModule.swiftinterface
+// RUN: %target-swift-frontend -I %t -module-cache-path %t/modulecache -emit-module -o %t/TestModule.swiftmodule -module-name TestModule %s
+// RUN: %{python} %S/Inputs/make-old.py %t/modulecache/OtherModule-*.swiftmodule
+//
+//
+// Actual test: make LeafModule.swiftinterface change size without changing mtime, check both cached modules get rebuilt.
+//
+// RUN: %{python} %S/Inputs/check-is-old.py %t/OtherModule.swiftinterface %t/LeafModule.swiftinterface
+// RUN: %{python} %S/Inputs/check-is-old.py %t/modulecache/OtherModule-*.swiftmodule %t/modulecache/LeafModule-*.swiftmodule
+// RUN: echo "// size change" >>%t/LeafModule.swiftinterface
+// RUN: %{python} %S/Inputs/make-old.py %t/LeafModule.swiftinterface
+// RUN: %{python} %S/Inputs/check-is-old.py %t/LeafModule.swiftinterface
+// RUN: rm %t/TestModule.swiftmodule
+// RUN: %target-swift-frontend -I %t -module-cache-path %t/modulecache -emit-module -o %t/TestModule.swiftmodule -module-name TestModule %s
+// RUN: %{python} %S/Inputs/check-is-new.py %t/modulecache/OtherModule-*.swiftmodule %t/modulecache/LeafModule-*.swiftmodule
+
+import OtherModule
+
+public func TestFunc() {
+    print(OtherFunc())
+}

test/ModuleInterface/ModuleCache/module-cache-no-rebuild.swift

@@ -0,0 +1,42 @@
+// RUN: %empty-directory(%t)
+// RUN: %empty-directory(%t/modulecache)
+//
+// Setup builds a module TestModule that depends on OtherModule and LeafModule (built from other.swift and leaf.swift).
+// During setup, input and intermediate mtimes are all set to a constant 'old' time (long in the past).
+//
+// We then rebuild TestModule a second time, without changing any inputs, and confirm none of the files has a new mtime.
+//
+//
+// Setup phase 1: Write input files.
+//
+// RUN: echo 'public func LeafFunc() -> Int { return 10; }' >%t/leaf.swift
+//
+// RUN: echo 'import LeafModule' >%t/other.swift
+// RUN: echo 'public func OtherFunc() -> Int { return LeafFunc(); }' >>%t/other.swift
+//
+//
+// Setup phase 2: build modules, pushing timestamps of inputs and intermediates into the past as we go.
+//
+// RUN: %{python} %S/Inputs/make-old.py %t/leaf.swift %t/other.swift
+// RUN: %target-swift-frontend -I %t -emit-module-interface-path %t/LeafModule.swiftinterface -module-name LeafModule %t/leaf.swift -emit-module -o /dev/null
+// RUN: %{python} %S/Inputs/make-old.py %t/LeafModule.swiftinterface
+// RUN: %target-swift-frontend -I %t -module-cache-path %t/modulecache -emit-module-interface-path %t/OtherModule.swiftinterface -module-name OtherModule %t/other.swift -emit-module -o /dev/null
+// RUN: %{python} %S/Inputs/make-old.py %t/modulecache/LeafModule-*.swiftmodule %t/OtherModule.swiftinterface
+// RUN: %target-swift-frontend -I %t -module-cache-path %t/modulecache -emit-module -o %t/TestModule.swiftmodule -module-name TestModule %s
+// RUN: %{python} %S/Inputs/make-old.py %t/modulecache/OtherModule-*.swiftmodule
+//
+//
+// Actual test: rebuild output, check no intermediates gets rebuilt.
+//
+// RUN: %{python} %S/Inputs/check-is-old.py %t/OtherModule.swiftinterface %t/LeafModule.swiftinterface
+// RUN: %{python} %S/Inputs/check-is-old.py %t/modulecache/OtherModule-*.swiftmodule %t/modulecache/LeafModule-*.swiftmodule
+// RUN: rm %t/TestModule.swiftmodule
+// RUN: %target-swift-frontend -I %t -module-cache-path %t/modulecache -emit-module -o %t/TestModule.swiftmodule -module-name TestModule %s
+// RUN: %{python} %S/Inputs/check-is-old.py %t/OtherModule.swiftinterface %t/LeafModule.swiftinterface
+// RUN: %{python} %S/Inputs/check-is-old.py %t/modulecache/OtherModule-*.swiftmodule %t/modulecache/LeafModule-*.swiftmodule
+
+import OtherModule
+
+public func TestFunc() {
+    print(OtherFunc())
+}

test/ModuleInterface/ModuleCache/prebuilt-module-cache-archs.swift

@@ -0,0 +1,36 @@
+// RUN: %empty-directory(%t)
+// RUN: %empty-directory(%t/include/Lib.swiftmodule)
+// RUN: cp %S/Inputs/prebuilt-module-cache/Lib.swiftinterface %t/include/Lib.swiftmodule/%target-cpu.swiftinterface
+
+// Baseline check: if the prebuilt cache path does not exist, everything should
+// still work.
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -sdk %t/include -I %t/include/ -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+
+// Baseline check: if the module is not in the prebuilt cache, build it
+// normally.
+// RUN: %empty-directory(%t/prebuilt-cache)
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -sdk %t/include -I %t/include/ -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+
+// Do a manual prebuild, and see if it gets picked up.
+// RUN: %empty-directory(%t/MCP)
+// RUN: %empty-directory(%t/prebuilt-cache/Lib.swiftmodule)
+// RUN: sed -e 's/FromInterface/FromPrebuilt/g' %S/Inputs/prebuilt-module-cache/Lib.swiftinterface | %target-swift-frontend -parse-stdlib -module-cache-path %t/MCP -emit-module-path %t/prebuilt-cache/Lib.swiftmodule/%target-swiftmodule-name - -module-name Lib
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -sdk %t/include -I %t/include/ -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1 | %FileCheck -check-prefix=FROM-PREBUILT %s
+
+// Make sure we installed a forwarding module.
+// RUN: %{python} %S/Inputs/check-is-forwarding-module.py %t/MCP/Lib-*.swiftmodule
+
+// What if the module is invalid?
+// RUN: rm %t/prebuilt-cache/Lib.swiftmodule/%target-swiftmodule-name && touch %t/prebuilt-cache/Lib.swiftmodule/%target-swiftmodule-name
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -sdk %t/include -I %t/include/ -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+
+// What if the arch is missing?
+// RUN: rm %t/prebuilt-cache/Lib.swiftmodule/%target-swiftmodule-name
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -sdk %t/include -I %t/include/ -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+
+import Lib
+
+struct X {}
+let _: X = Lib.testValue
+// FROM-INTERFACE: [[@LINE-1]]:16: error: cannot convert value of type 'FromInterface' to specified type 'X'
+// FROM-PREBUILT: [[@LINE-2]]:16: error: cannot convert value of type 'FromPrebuilt' to specified type 'X'

test/ModuleInterface/ModuleCache/prebuilt-module-cache-fallback.swift

@@ -0,0 +1,45 @@
+// Like prebuilt-module-cache-archs.swift, but testing the fallback behavior.
+// This means we have to know the expected names in advance, so this test only
+// runs on macOS.
+
+// REQUIRES: OS=macosx
+// REQUIRES: CPU=x86_64
+
+// Use the short name "x86_64.swiftmodule".
+// RUN: %empty-directory(%t)
+// RUN: %empty-directory(%t/include/Lib.swiftmodule)
+// RUN: cp %S/Inputs/prebuilt-module-cache/Lib.swiftinterface %t/include/Lib.swiftmodule/x86_64.swiftinterface
+
+// Do a manual prebuild with the long name "x86_64-apple-macos.swiftmodule",
+// and see if it gets picked up.
+// RUN: %empty-directory(%t/MCP)
+// RUN: %empty-directory(%t/prebuilt-cache/Lib.swiftmodule)
+// RUN: sed -e 's/FromInterface/FromPrebuiltLong/g' %S/Inputs/prebuilt-module-cache/Lib.swiftinterface | %target-swift-frontend -parse-stdlib -module-cache-path %t/MCP -emit-module-path %t/prebuilt-cache/Lib.swiftmodule/x86_64-apple-macos.swiftmodule - -module-name Lib
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -sdk %t/include -I %t/include/ -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1 | %FileCheck -check-prefix=FROM-PREBUILT-LONG %s
+// RUN: %{python} %S/Inputs/check-is-forwarding-module.py %t/MCP/Lib-*.swiftmodule
+
+// Prefer a matching name.
+// RUN: %empty-directory(%t/MCP)
+// RUN: sed -e 's/FromInterface/FromPrebuiltShort/g' %S/Inputs/prebuilt-module-cache/Lib.swiftinterface | %target-swift-frontend -parse-stdlib -module-cache-path %t/MCP -emit-module-path %t/prebuilt-cache/Lib.swiftmodule/x86_64.swiftmodule - -module-name Lib
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -sdk %t/include -I %t/include/ -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1 | %FileCheck -check-prefix=FROM-PREBUILT-SHORT %s
+// RUN: %{python} %S/Inputs/check-is-forwarding-module.py %t/MCP/Lib-*.swiftmodule
+
+// Prefer a matching name in the other direction too.
+// RUN: %empty-directory(%t/MCP)
+// RUN: mv %t/include/Lib.swiftmodule/x86_64.swiftinterface %t/include/Lib.swiftmodule/x86_64-apple-macos.swiftinterface
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -sdk %t/include -I %t/include/ -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1 | %FileCheck -check-prefix=FROM-PREBUILT-LONG %s
+// RUN: %{python} %S/Inputs/check-is-forwarding-module.py %t/MCP/Lib-*.swiftmodule
+
+// Don't do the fallback thing for long names to short names.
+// RUN: %empty-directory(%t/MCP)
+// RUN: rm %t/prebuilt-cache/Lib.swiftmodule/x86_64-apple-macos.swiftmodule
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -sdk %t/include -I %t/include/ -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: not %{python} %S/Inputs/check-is-forwarding-module.py %t/MCP/Lib-*.swiftmodule
+
+import Lib
+
+struct X {}
+let _: X = Lib.testValue
+// FROM-INTERFACE: [[@LINE-1]]:16: error: cannot convert value of type 'FromInterface' to specified type 'X'
+// FROM-PREBUILT-LONG: [[@LINE-2]]:16: error: cannot convert value of type 'FromPrebuiltLong' to specified type 'X'
+// FROM-PREBUILT-SHORT: [[@LINE-3]]:16: error: cannot convert value of type 'FromPrebuiltShort' to specified type 'X'

test/ModuleInterface/ModuleCache/prebuilt-module-cache-forwarding.swift

@@ -0,0 +1,52 @@
+// RUN: %empty-directory(%t)
+// RUN: %empty-directory(%t/MCP)
+// RUN: %empty-directory(%t/prebuilt-cache)
+
+// First, prebuild a module and put it in the prebuilt cache.
+// RUN: sed -e 's/FromInterface/FromPrebuilt/g' %S/Inputs/prebuilt-module-cache/Lib.swiftinterface | tr -d '\r' > %t/Lib.swiftinterface.tmp
+// RUN: mv %t/Lib.swiftinterface.tmp %t/Lib.swiftinterface
+// RUN: %target-swift-frontend -compile-module-from-interface -module-cache-path %t/MCP -serialize-parseable-module-interface-dependency-hashes -o %t/prebuilt-cache/Lib.swiftmodule %t/Lib.swiftinterface
+
+// Next, use the module and check if the forwarding module is in place.
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -sdk %S/Inputs -I %S/Inputs/prebuilt-module-cache/ -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1 | %FileCheck -check-prefix=FROM-PREBUILT %s
+
+// Make sure we installed a forwarding module.
+// RUN: %{python} %S/Inputs/check-is-forwarding-module.py %t/MCP/Lib-*.swiftmodule
+// RUN: cat %t/MCP/Lib-*.swiftmodule
+
+// Now invalidate a dependency of the prebuilt module, by changing the hash of the .swiftinterface.
+// RUN: cp %t/Lib.swiftinterface %t/Lib.swiftinterface.moved-aside
+// RUN: echo ' ' >> %t/Lib.swiftinterface
+
+// Make sure the forwarding file is replaced with a real module.
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -sdk %S/Inputs -I %S/Inputs/prebuilt-module-cache/ -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+
+// Delete the cached module we just created, put the old .swiftinterface back, and create the forwarding module again
+// RUN: %empty-directory(%t/MCP)
+// RUN: mv %t/Lib.swiftinterface.moved-aside %t/Lib.swiftinterface
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -sdk %S/Inputs -I %S/Inputs/prebuilt-module-cache/ -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1 | %FileCheck -check-prefix=FROM-PREBUILT %s
+
+// Move the prebuilt module out of the way, so the forwarding module points to nothing.
+// RUN: mv %t/prebuilt-cache/Lib.swiftmodule %t/prebuilt-cache/NotLib.swiftmodule
+
+// Make sure we delete the existing forwarding module and rebuild from an interface.
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -sdk %S/Inputs -I %S/Inputs/prebuilt-module-cache/ -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+
+// Move the prebuilt module back to its original path
+// RUN: mv %t/prebuilt-cache/NotLib.swiftmodule %t/prebuilt-cache/Lib.swiftmodule
+
+// If the forwarding module is corrupted, we shouldn't rebuild the module in the cache,
+// we should delete it and generate a new forwarding module.
+// RUN: %empty-directory(%t/MCP)
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -sdk %S/Inputs -I %S/Inputs/prebuilt-module-cache/ -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1
+// RUN: %{python} %S/Inputs/check-is-forwarding-module.py %t/MCP/Lib-*.swiftmodule
+// RUN: %{python} %S/../Inputs/make-unreadable.py %t/MCP/Lib-*.swiftmodule
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -sdk %S/Inputs -I %S/Inputs/prebuilt-module-cache/ -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1 | %FileCheck -check-prefix=FROM-PREBUILT %s
+// RUN: %{python} %S/Inputs/check-is-forwarding-module.py %t/MCP/Lib-*.swiftmodule
+
+import Lib
+
+struct X {}
+let _: X = Lib.testValue
+// FROM-INTERFACE: [[@LINE-1]]:16: error: cannot convert value of type 'FromInterface' to specified type 'X'
+// FROM-PREBUILT: [[@LINE-2]]:16: error: cannot convert value of type 'FromPrebuilt' to specified type 'X'

test/ModuleInterface/ModuleCache/prebuilt-module-cache-nonexistent-module-cache-path.swift

@@ -0,0 +1,13 @@
+// RUN: %empty-directory(%t)
+
+// Create a prebuilt module cache and populate it with a prebuilt module.
+// RUN: %empty-directory(%t/prebuilt-cache)
+// RUN: %target-swift-frontend -parse-stdlib %S/Inputs/prebuilt-module-cache/Lib.swiftinterface -emit-module-path %t/prebuilt-cache/Lib.swiftmodule - -module-name Lib
+
+// Compile against the module with a module cache that does not exist
+// RUN: %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/RandomPath/NonExistentCachePath -sdk %S/Inputs -I %S/Inputs/prebuilt-module-cache -prebuilt-module-cache-path %t/prebuilt-cache %s
+
+// Make sure we installed a forwarding module.
+// RUN: %{python} %S/Inputs/check-is-forwarding-module.py %t/RandomPath/NonExistentCachePath/Lib-*.swiftmodule
+
+import Lib

test/ModuleInterface/ModuleCache/prebuilt-module-cache-recursive.swift

@@ -0,0 +1,25 @@
+// RUN: %empty-directory(%t)
+
+// Baseline check: if the module is not in the prebuilt cache, build it
+// normally.
+// RUN: %empty-directory(%t/prebuilt-cache)
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -sdk %S/Inputs -I %S/Inputs/prebuilt-module-cache/ -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+
+// Do a manual prebuild, and see if it gets picked up.
+// RUN: %empty-directory(%t/MCP)
+// RUN: sed -e 's/FromInterface/FromPrebuilt/g' %S/Inputs/prebuilt-module-cache/Lib.swiftinterface | %target-swift-frontend -parse-stdlib -module-cache-path %t/MCP -emit-module-path %t/prebuilt-cache/Lib.swiftmodule - -module-name Lib
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -sdk %S/Inputs -I %S/Inputs/prebuilt-module-cache/ -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1 | %FileCheck -check-prefix=FROM-PREBUILT %s
+
+// Make sure we installed a forwarding module.
+// RUN: %{python} %S/Inputs/check-is-forwarding-module.py %t/MCP/Lib-*.swiftmodule
+
+// What if the module is invalid?
+// RUN: rm %t/prebuilt-cache/Lib.swiftmodule && touch %t/prebuilt-cache/Lib.swiftmodule
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -sdk %S/Inputs/ -I %S/Inputs/prebuilt-module-cache/ -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+
+import LibExporter
+
+struct X {}
+let _: X = Lib.testValue
+// FROM-INTERFACE: [[@LINE-1]]:16: error: cannot convert value of type 'FromInterface' to specified type 'X'
+// FROM-PREBUILT: [[@LINE-2]]:16: error: cannot convert value of type 'FromPrebuilt' to specified type 'X'

test/ModuleInterface/ModuleCache/prebuilt-module-cache-root.swift

@@ -0,0 +1,28 @@
+// RUN: %empty-directory(%t)
+
+// -- construct prebuilt
+// RUN: %empty-directory(%t/prebuilt-cache)
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -sdk %S/Inputs -I %S/Inputs/prebuilt-module-cache/ -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+
+// -- generate a manual prebuilt
+// RUN: %empty-directory(%t/MCP)
+// RUN: sed -e 's/FromInterface/FromPrebuilt/g' %S/Inputs/prebuilt-module-cache/Lib.swiftinterface | tr -d '\r' | %target-swift-frontend -parse-stdlib -module-cache-path %t/MCP -emit-module-path %t/prebuilt-cache/Lib.swiftmodule - -module-name Lib
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -sdk %S/Inputs -I %S/Inputs/prebuilt-module-cache/ -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1 | %FileCheck -check-prefix=FROM-PREBUILT %s
+// -- ensure we installed a forwarding module
+// RUN: %{python} %S/Inputs/check-is-forwarding-module.py %t/MCP/Lib-*.swiftmodule
+
+// -- ensure that the search path is in the root
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -sdk / -I %S/Inputs/prebuilt-module-cache/ -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1 | %FileCheck -check-prefix=FROM-PREBUILT %s
+
+// This test is not supported on Windows since the root is not / but rather a
+// drive letter followed by a colon.
+// UNSUPPORTED: OS=windows-msvc
+
+import Lib
+
+struct X {}
+let _: X = Lib.testValue
+
+// FROM-INTERFACE: [[@LINE-2]]:16: error: cannot convert value of type 'FromInterface' to specified type 'X'
+// FROM-PREBUILT: [[@LINE-3]]:16: error: cannot convert value of type 'FromPrebuilt' to specified type 'X'
+

test/ModuleInterface/ModuleCache/prebuilt-module-cache-unusable.swift

@@ -0,0 +1,32 @@
+// RUN: %empty-directory(%t)
+// RUN: %empty-directory(%t/MCP)
+// RUN: %empty-directory(%t/prebuilt-cache/Lib.swiftmodule)
+// RUN: %empty-directory(%t/include/Lib.swiftmodule)
+// RUN: cp %S/Inputs/prebuilt-module-cache/Lib.swiftinterface %t/include/Lib.swiftmodule/%target-cpu.swiftinterface
+
+// Prebuild a module for the current target CPU, and put it in the prebuilt cache under some imaginary CPU.
+// RUN: sed -e 's/FromInterface/FromPrebuilt/g' %t/include/Lib.swiftmodule/%target-cpu.swiftinterface | %target-swift-frontend -parse-stdlib -module-cache-path %t/MCP -emit-module-path %t/prebuilt-cache/Lib.swiftmodule/leg128.swiftmodule - -module-name Lib
+
+// Make sure that, if there's a module for a different architecture
+// present in the prebuilt cache, it's ignored and the module is
+// rebuilt from an interface.
+
+// RUN: not %target-swift-frontend -typecheck -module-cache-path %t/MCP -sdk %t/include -I %t/include -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1 | %FileCheck %s --check-prefix FROM-INTERFACE
+// RUN: %empty-directory(%t/MCP)
+
+// Make sure it works fine if the module is for this architecture.
+// RUN: mv %t/prebuilt-cache/Lib.swiftmodule/leg128.swiftmodule %t/prebuilt-cache/Lib.swiftmodule/%target-swiftmodule-name
+// RUN: not %target-swift-frontend -typecheck -module-cache-path %t/MCP -sdk %t/include -I %t/include -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1 | %FileCheck %s --check-prefix FROM-PREBUILT
+
+// Now make sure it works if there's nothing in the prebuilt cache
+// RUN: %empty-directory(%t/prebuilt-cache/Lib.swiftmodule)
+// RUN: %empty-directory(%t/MCP)
+
+// RUN: not %target-swift-frontend -typecheck -module-cache-path %t/MCP -sdk %t/include -I %t/include -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1 | %FileCheck %s --check-prefix FROM-INTERFACE
+
+import Lib
+
+struct X {}
+let _: X = Lib.testValue
+// FROM-PREBUILT: [[@LINE-1]]:16: error: cannot convert value of type 'FromPrebuilt' to specified type 'X'
+// FROM-INTERFACE: [[@LINE-2]]:16: error: cannot convert value of type 'FromInterface' to specified type 'X'

test/ModuleInterface/ModuleCache/prebuilt-module-cache.swift

@@ -0,0 +1,38 @@
+// RUN: %empty-directory(%t)
+
+// Baseline check: if the prebuilt cache path does not exist, everything should
+// still work.
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -sdk %S/Inputs -I %S/Inputs/prebuilt-module-cache/ -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+
+// Baseline check: if the module is not in the prebuilt cache, build it
+// normally.
+// RUN: %empty-directory(%t/prebuilt-cache)
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -sdk %S/Inputs -I %S/Inputs/prebuilt-module-cache/ -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+
+// Do a manual prebuild, and see if it gets picked up.
+// RUN: %empty-directory(%t/MCP)
+// RUN: sed -e 's/FromInterface/FromPrebuilt/g' %S/Inputs/prebuilt-module-cache/Lib.swiftinterface | tr -d '\r' | %target-swift-frontend -parse-stdlib -module-cache-path %t/MCP -emit-module-path %t/prebuilt-cache/Lib.swiftmodule - -module-name Lib
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -sdk %S/Inputs -I %S/Inputs/prebuilt-module-cache/ -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1 | %FileCheck -check-prefix=FROM-PREBUILT %s
+
+// Make sure we installed a forwarding module.
+// RUN: %{python} %S/Inputs/check-is-forwarding-module.py %t/MCP/Lib-*.swiftmodule
+
+// Try some variations on the detection that the search path is in the SDK:
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -sdk %S/Inputs -I %S/Inputs/prebuilt-module-cache/ -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1 | %FileCheck -check-prefix=FROM-PREBUILT %s
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -sdk %S//Inputs -I %S/Inputs/prebuilt-module-cache/ -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1 | %FileCheck -check-prefix=FROM-PREBUILT %s
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -sdk %S/Inputs/prebuilt-module-cache -I %S/Inputs/prebuilt-module-cache/ -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1 | %FileCheck -check-prefix=FROM-PREBUILT %s
+
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -sdk %S/Inputs/p -I %S/Inputs/prebuilt-module-cache/ -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -sdk %S/garbage-path -I %S/Inputs/prebuilt-module-cache/ -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -sdk "" -I %S/Inputs/prebuilt-module-cache/ -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+
+// What if the module is invalid?
+// RUN: rm %t/prebuilt-cache/Lib.swiftmodule && touch %t/prebuilt-cache/Lib.swiftmodule
+// RUN: not %target-swift-frontend -typecheck -parse-stdlib -module-cache-path %t/MCP -sdk %S/Inputs/ -I %S/Inputs/prebuilt-module-cache/ -prebuilt-module-cache-path %t/prebuilt-cache %s 2>&1 | %FileCheck -check-prefix=FROM-INTERFACE %s
+
+import Lib
+
+struct X {}
+let _: X = Lib.testValue
+// FROM-INTERFACE: [[@LINE-1]]:16: error: cannot convert value of type 'FromInterface' to specified type 'X'
+// FROM-PREBUILT: [[@LINE-2]]:16: error: cannot convert value of type 'FromPrebuilt' to specified type 'X'

test/ModuleInterface/ModuleCache/prefer-local-module-to-sdk-framework.swift

@@ -0,0 +1,31 @@
+// RUN: %empty-directory(%t/BuildDir/Lib.framework/Modules/Lib.swiftmodule)
+// RUN: %empty-directory(%t/SecondBuildDir/Lib.framework/Modules/Lib.swiftmodule)
+// RUN: %empty-directory(%t/ModuleCache)
+
+// RUN: echo 'public func showsUpInBothPlaces() {}' > %t/Lib.swift
+
+// 1. Create a .swiftinterface file containing just one API, and put it inside a second build dir (without a .swiftmodule)
+// RUN: %target-swift-frontend -typecheck %t/Lib.swift -emit-module-interface-path %t/SecondBuildDir/Lib.framework/Modules/Lib.swiftmodule/%target-cpu.swiftinterface -module-name Lib
+
+// 2. Add a new API to the module, and compile just the serialized version in the build dir.
+// RUN: echo 'public func onlyInTheCompiledModule() {}' >> %t/Lib.swift
+// RUN: %target-swift-frontend -emit-module %t/Lib.swift -o %t/BuildDir/Lib.framework/Modules/Lib.swiftmodule/%target-cpu.swiftmodule -emit-module-interface-path %t/BuildDir/Lib.framework/Modules/Lib.swiftmodule/%target-cpu.swiftinterface -module-name Lib
+
+// 3. Make sure when we compile this test file, we can access both APIs since we'll
+//    load the compiled .swiftmodule instead of the .swiftinterface in the SDK.
+// RUN: %target-swift-frontend -typecheck %s -F %t/BuildDir -F %t/SecondBuildDir -module-cache-path %t/ModuleCache
+
+// 4. Make sure we didn't compile any .swiftinterfaces into the module cache.
+// RUN: ls %t/ModuleCache | not grep 'swiftmodule'
+
+// 5. This should also work if the swiftinterface isn't present in the first build dir.
+// RUN: rm %t/BuildDir/Lib.framework/Modules/Lib.swiftmodule/%target-cpu.swiftinterface
+// RUN: %target-swift-frontend -typecheck %s -F %t/BuildDir -F %t/SecondBuildDir -module-cache-path %t/ModuleCache
+
+// 6. Make sure we /still/ didn't compile any .swiftinterfaces into the module cache.
+// RUN: ls %t/ModuleCache | not grep 'swiftmodule'
+
+import Lib
+
+showsUpInBothPlaces()
+onlyInTheCompiledModule()

test/ModuleInterface/ModuleCache/prefer-local-module-to-sdk.swift

@@ -0,0 +1,31 @@
+// RUN: %empty-directory(%t/BuildDir)
+// RUN: %empty-directory(%t/SecondBuildDir/Lib.swiftmodule)
+// RUN: %empty-directory(%t/ModuleCache)
+
+// RUN: echo 'public func showsUpInBothPlaces() {}' > %t/Lib.swift
+
+// 1. Create a .swiftinterface file containing just one API, and put it inside a second build dir (without a .swiftmodule)
+// RUN: %target-swift-frontend -typecheck %t/Lib.swift -emit-module-interface-path %t/SecondBuildDir/Lib.swiftmodule/%target-cpu.swiftinterface -module-name Lib
+
+// 2. Add a new API to the module, and compile just the serialized version in the build dir.
+// RUN: echo 'public func onlyInTheCompiledModule() {}' >> %t/Lib.swift
+// RUN: %target-swift-frontend -emit-module %t/Lib.swift -o %t/BuildDir/Lib.swiftmodule -emit-module-interface-path %t/BuildDir/Lib.swiftinterface
+
+// 3. Make sure when we compile this test file, we can access both APIs since we'll
+//    load the compiled .swiftmodule instead of the .swiftinterface in the SDK.
+// RUN: %target-swift-frontend -typecheck %s -I %t/BuildDir -I %t/SecondBuildDir -module-cache-path %t/ModuleCache
+
+// 4. Make sure we didn't compile any .swiftinterfaces into the module cache.
+// RUN: ls %t/ModuleCache | not grep 'swiftmodule'
+
+// 5. This should also work if the swiftinterface isn't present in the first build dir.
+// RUN: rm %t/BuildDir/Lib.swiftinterface
+// RUN: %target-swift-frontend -typecheck %s -I %t/BuildDir -I %t/SecondBuildDir -module-cache-path %t/ModuleCache
+
+// 6. Make sure we /still/ didn't compile any .swiftinterfaces into the module cache.
+// RUN: ls %t/ModuleCache | not grep 'swiftmodule'
+
+import Lib
+
+showsUpInBothPlaces()
+onlyInTheCompiledModule()

test/ModuleInterface/ModuleCache/swiftdoc-next-to-swiftinterface.swift

@@ -0,0 +1,25 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-swift-frontend -emit-module -emit-module-interface-path %t/Lib.swiftinterface -emit-module-doc -parse-stdlib -o %t/Lib.swiftmodule %s
+// RUN: %target-swift-ide-test -print-module -module-to-print=Lib -access-filter-public -I %t -source-filename=x -prefer-type-repr=false -fully-qualified-types=true > %t/from-module.txt
+// RUN: %FileCheck %s < %t/from-module.txt
+
+// RUN: rm %t/Lib.swiftmodule
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-serialized %target-swift-ide-test -print-module -module-to-print=Lib -access-filter-public -I %t -source-filename=x -prefer-type-repr=false -fully-qualified-types=true > %t/from-interface.txt
+// RUN: diff %t/from-module.txt %t/from-interface.txt
+
+// Try again with architecture-specific subdirectories.
+// RUN: %empty-directory(%t)
+// RUN: %empty-directory(%t/Lib.swiftmodule)
+// RUN: %target-swift-frontend -emit-module -emit-module-interface-path %t/Lib.swiftmodule/%target-cpu.swiftinterface -emit-module-doc -parse-stdlib -o %t/Lib.swiftmodule/%target-swiftmodule-name -module-name Lib %s
+// RUN: %target-swift-ide-test -print-module -module-to-print=Lib -access-filter-public -I %t -source-filename=x -prefer-type-repr=false -fully-qualified-types=true > %t/from-module.txt
+// RUN: %FileCheck %s < %t/from-module.txt
+
+// RUN: rm %t/Lib.swiftmodule/%target-swiftmodule-name
+// RUN: env SWIFT_FORCE_MODULE_LOADING=prefer-serialized %target-swift-ide-test -print-module -module-to-print=Lib -access-filter-public -I %t -source-filename=x -prefer-type-repr=false -fully-qualified-types=true > %t/from-interface.txt
+// RUN: diff %t/from-module.txt %t/from-interface.txt
+
+/// Very important documentation!
+public struct SomeStructWithDocumentation {}
+
+// CHECK: Very important documentation!
+// CHECK-NEXT: struct SomeStructWithDocumentation {