Merge pull request swiftlang#71260 from cachemeifyoucan/eng/PR-120554271

[Caching] Fix versioned canImport check for swift module

Author: cachemeifyoucan

lib/Frontend/ModuleInterfaceLoader.cpp

@@ -22,6 +22,7 @@
 #include "swift/Basic/Platform.h"
 #include "swift/Basic/StringExtras.h"
 #include "swift/Frontend/CachingUtils.h"
+#include "swift/Frontend/CompileJobCacheResult.h"
 #include "swift/Frontend/Frontend.h"
 #include "swift/Frontend/ModuleInterfaceSupport.h"
 #include "swift/Parse/ParseVersion.h"
@@ -2446,12 +2447,19 @@ struct ExplicitCASModuleLoader::Implementation {
     if (!moduleRef)
       return nullptr;
 
-    clang::cas::CompileJobResultSchema schema(CAS);
+    auto proxy = CAS.getProxy(*moduleRef);
+    if (!proxy)
+      return proxy.takeError();
+
+    swift::cas::CompileJobResultSchema schema(CAS);
+    if (!schema.isRootNode(*proxy))
+      return nullptr;
+
     auto result = schema.load(*moduleRef);
     if (!result)
       return result.takeError();
-    auto output = result->getOutput(
-        clang::cas::CompileJobCacheResult::OutputKind::MainOutput);
+
+    auto output = result->getOutput(file_types::ID::TY_SwiftModuleFile);
     if (!output)
       return nullptr;
 

test/CAS/can-import.swift

@@ -14,6 +14,9 @@
 // RUN: %{python} %S/Inputs/BuildCommandExtractor.py %t/deps.json clang:B > %t/B.cmd
 // RUN: %swift_frontend_plain @%t/B.cmd
 
+// RUN: %{python} %S/Inputs/BuildCommandExtractor.py %t/deps.json C > %t/C.cmd
+// RUN: %swift_frontend_plain @%t/C.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
 
@@ -38,9 +41,18 @@ import A.Missing
 func b() {}
 #endif
 
+#if canImport(C, _version: 1.0)
+import C
+#endif
+
+#if canImport(C, _version: 2.0)
+import Missing
+#endif
+
 func useA() {
   a()
   b()
+  c()
 }
 
 //--- include/module.modulemap
@@ -61,3 +73,8 @@ void notused(void);
 
 //--- include/B.h
 void notused2(void);
+
+//--- include/C.swiftinterface
+// swift-interface-format-version: 1.0
+// swift-module-flags: -module-name C -O -disable-implicit-string-processing-module-import -disable-implicit-concurrency-module-import -parse-stdlib -user-module-version 1.0
+public func c() { }