Merge pull request #41546 from bnbarham/use-overlay-fs-instead

[Importer] Wrap the VFS passed to Clang with an overlay FS instead

Author: bnbarham

lib/ClangImporter/ClangImporter.cpp

@@ -1099,8 +1099,7 @@ ClangImporter::create(ASTContext &ctx,
 
   // Wrap Swift's FS to allow Clang to override the working directory
   llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS =
-      llvm::vfs::RedirectingFileSystem::create({}, true,
-                                               *ctx.SourceMgr.getFileSystem());
+    new llvm::vfs::OverlayFileSystem(ctx.SourceMgr.getFileSystem());
 
   // Create a new Clang compiler invocation.
   {

test/SourceKit/CursorInfo/cursor_overlay.swift

@@ -0,0 +1,54 @@
+// RUN: %empty-directory(%t)
+// RUN: split-file --leading-lines %s %t
+// RUN: sed -e "s@EXTERNAL_DIR@%{/t:regex_replacement}/A@g" -e "s@NAME_DIR@%{/t:regex_replacement}/B@g" %t/base.yaml > %t/overlay.yaml
+
+//--- use.swift
+import MyMod
+
+// RUN: %sourcekitd-test -req=cursor -pos=%(line+3):13 %t/use.swift -- -I%t/B -vfsoverlay %t/overlay.yaml %t/use.swift | %FileCheck --check-prefix=CHECK-A %s
+// RUN: %sourcekitd-test -req=cursor -pos=%(line+2):22 %t/use.swift -- -I%t/B -vfsoverlay %t/overlay.yaml %t/use.swift | %FileCheck --check-prefix=CHECK-B %s
+// RUN: %sourcekitd-test -req=cursor -pos=%(line+1):31 %t/use.swift -- -I%t/B -vfsoverlay %t/overlay.yaml %t/use.swift | %FileCheck --check-prefix=CHECK-C %s
+func f(arg: A, arg2: B, arg3: C) {}
+
+//--- A/A.h
+// CHECK-A: source.lang.swift.ref.struct ({{.*}}{{/|\\}}A{{/|\\}}A.h:[[@LINE+1]]:8-[[@LINE+1]]:9)
+struct A {
+  int a;
+};
+
+//--- A/B.h
+
+//--- A/C.h
+// CHECK-C: source.lang.swift.ref.struct ({{.*}}{{/|\\}}A{{/|\\}}C.h:[[@LINE+1]]:8-[[@LINE+1]]:9)
+struct C {
+  int c;
+};
+
+//--- B/B.h
+#include "C.h"
+
+// CHECK-B: source.lang.swift.ref.struct ({{.*}}{{/|\\}}B{{/|\\}}B.h:[[@LINE+1]]:8-[[@LINE+1]]:9)
+struct B {
+  int b;
+};
+
+//--- B/module.modulemap
+module MyMod {
+  header "A.h"
+  header "B.h"
+}
+
+//--- base.yaml
+{
+  version: 0,
+  redirecting-with: "fallback",
+  use-external-names: true,
+  roots: [
+    {
+      type: "directory-remap",
+      name: "NAME_DIR",
+      external-contents: "EXTERNAL_DIR"
+    }
+  ]
+}
+