Merge pull request #72341 from cachemeifyoucan/eng/PR-123655183

[ExplicitModuleBuild] Support `-vfsoverlay` swift option

Author: cachemeifyoucan

lib/AST/ModuleDependencies.cpp

@@ -477,6 +477,10 @@ void SwiftDependencyTracker::addCommonSearchPathDeps(
       FS->status(LayoutFile);
     }
   }
+
+  // Add VFSOverlay file.
+  for (auto &Overlay: Opts.VFSOverlayFiles)
+    FS->status(Overlay);
 }
 
 void SwiftDependencyTracker::startTracking() {

lib/ClangImporter/ClangModuleDependencyScanner.cpp

@@ -199,8 +199,8 @@ ModuleDependencyVector ClangImporter::bridgeClangModuleDependencies(
     // Swift frontend option for input file path (Foo.modulemap).
     swiftArgs.push_back(remapPath(clangModuleDep.ClangModuleMapFile));
 
-    // Handle VFSOverlay.
-    if (!ctx.SearchPathOpts.VFSOverlayFiles.empty()) {
+    // Handle VFSOverlay. If include tree is used, there is no need for overlay.
+    if (!ctx.ClangImporterOpts.UseClangIncludeTree) {
       for (auto &overlay : ctx.SearchPathOpts.VFSOverlayFiles) {
         swiftArgs.push_back("-vfsoverlay");
         swiftArgs.push_back(remapPath(overlay));

lib/Frontend/ModuleInterfaceLoader.cpp

@@ -1879,6 +1879,13 @@ InterfaceSubContextDelegateImpl::InterfaceSubContextDelegateImpl(
   genericSubInvocation.getSearchPathOptions().ExplicitSwiftModuleMap =
     explicitSwiftModuleMap.str();
 
+  // Pass down VFSOverlay flags (do not need to inherit the options because
+  // FileSystem is shared).
+  for (auto &Overlay : searchPathOpts.VFSOverlayFiles) {
+    GenericArgs.push_back("-vfsoverlay");
+    GenericArgs.push_back(Overlay);
+  }
+
   // Load plugin libraries for macro expression as default arguments
   genericSubInvocation.getSearchPathOptions().PluginSearchOpts =
       searchPathOpts.PluginSearchOpts;

test/CAS/vfsoverlay.swift

@@ -0,0 +1,57 @@
+// RUN: %empty-directory(%t)
+// RUN: split-file %s %t
+// RUN: sed -e "s@VFS_DIR@%{/t:regex_replacement}/vfs@g" -e "s@EXTERNAL_DIR@%{/t:regex_replacement}/hidden@g" %t/base.yaml > %t/overlay.yaml
+
+// RUN: %target-swift-frontend -emit-module -module-name B -o %t/B.swiftmodule -swift-version 5 \
+// RUN:   -disable-implicit-string-processing-module-import -disable-implicit-concurrency-module-import -parse-stdlib \
+// RUN:   -emit-module-interface-path %t/hidden/B.swiftinterface -enable-library-evolution %t/hidden/B.swift
+
+// RUN: %target-swift-frontend -scan-dependencies -module-name Test -module-cache-path %t/clang-module-cache -O \
+// RUN:   -disable-implicit-string-processing-module-import -disable-implicit-concurrency-module-import -parse-stdlib \
+// RUN:   %t/vfs/test.swift -o %t/deps.json -swift-version 5 -cache-compile-job -cas-path %t/cas \
+// RUN:   -vfsoverlay %t/overlay.yaml -Xcc -ivfsoverlay -Xcc %t/overlay.yaml -I %t/vfs
+
+// RUN: %{python} %S/Inputs/BuildCommandExtractor.py %t/deps.json clang:A > %t/A.cmd
+// RUN: %swift_frontend_plain @%t/A.cmd
+
+// RUN: %{python} %S/Inputs/BuildCommandExtractor.py %t/deps.json B > %t/B.cmd
+// RUN: %swift_frontend_plain @%t/B.cmd
+
+// RUN: %{python} %S/Inputs/GenerateExplicitModuleMap.py %t/deps.json > %t/map.json
+// RUN: llvm-cas --cas %t/cas --make-blob --data %t/map.json > %t/map.casid
+
+// RUN: %{python} %S/Inputs/BuildCommandExtractor.py %t/deps.json Test > %t/MyApp.cmd
+// RUN: %target-swift-frontend \
+// RUN:   -typecheck -cache-compile-job -cas-path %t/cas -vfsoverlay %t/overlay.yaml \
+// RUN:   -swift-version 5 -disable-implicit-swift-modules \
+// RUN:   -disable-implicit-string-processing-module-import -disable-implicit-concurrency-module-import -parse-stdlib \
+// RUN:   -module-name Test -explicit-swift-module-map-file @%t/map.casid \
+// RUN:   %t/vfs/test.swift @%t/MyApp.cmd
+
+//--- hidden/test.swift
+import A
+import B
+
+//--- hidden/module.modulemap
+module A {
+  header "A.h"
+  export *
+}
+
+//--- hidden/A.h
+void a(void);
+
+//--- hidden/B.swift
+public func b() {}
+
+//--- base.yaml
+{
+  version: 0,
+  roots: [
+    {
+      type: "directory-remap",
+      name: "VFS_DIR",
+      external-contents: "EXTERNAL_DIR"
+    }
+  ]
+}