Do not fail the build on only finding incompatible-architecture modules on 'canImport'

This change refactors the module loaders to explicitly take a parameter indicating whether or not the loader is handling a 'canImport' query, in order to avoid emitting an error when finding a dependency Swift binary module with only imcompatible architecture variants present.

Resolves rdar://161175498

Author: artemcm

include/swift/Frontend/ModuleInterfaceLoader.h

@@ -152,7 +152,7 @@ class ExplicitSwiftModuleLoader: public SerializedModuleLoaderBase {
                   std::unique_ptr<llvm::MemoryBuffer> *moduleBuffer,
                   std::unique_ptr<llvm::MemoryBuffer> *moduleDocBuffer,
                   std::unique_ptr<llvm::MemoryBuffer> *moduleSourceInfoBuffer,
-                  bool skipBuildingInterface, bool isTestableDependencyLookup,
+                  bool isCanImportLookup, bool isTestableDependencyLookup,
                   bool &isFramework, bool &isSystemModule) override;
 
   std::error_code findModuleFilesInDirectory(
@@ -162,7 +162,7 @@ class ExplicitSwiftModuleLoader: public SerializedModuleLoaderBase {
       std::unique_ptr<llvm::MemoryBuffer> *ModuleBuffer,
       std::unique_ptr<llvm::MemoryBuffer> *ModuleDocBuffer,
       std::unique_ptr<llvm::MemoryBuffer> *ModuleSourceInfoBuffer,
-      bool SkipBuildingInterface, bool IsFramework,
+      bool isCanImportLookup, bool IsFramework,
       bool IsTestableDependencyLookup = false) override;
 
   bool canImportModule(ImportPath::Module named, SourceLoc loc,
@@ -201,7 +201,7 @@ class ExplicitCASModuleLoader : public SerializedModuleLoaderBase {
                   std::unique_ptr<llvm::MemoryBuffer> *moduleBuffer,
                   std::unique_ptr<llvm::MemoryBuffer> *moduleDocBuffer,
                   std::unique_ptr<llvm::MemoryBuffer> *moduleSourceInfoBuffer,
-                  bool skipBuildingInterface, bool isTestableDependencyLookup,
+                  bool isCanImportLookup, bool isTestableDependencyLookup,
                   bool &isFramework, bool &isSystemModule) override;
 
   std::error_code findModuleFilesInDirectory(
@@ -211,7 +211,7 @@ class ExplicitCASModuleLoader : public SerializedModuleLoaderBase {
       std::unique_ptr<llvm::MemoryBuffer> *ModuleBuffer,
       std::unique_ptr<llvm::MemoryBuffer> *ModuleDocBuffer,
       std::unique_ptr<llvm::MemoryBuffer> *ModuleSourceInfoBuffer,
-      bool SkipBuildingInterface, bool IsFramework,
+      bool IsCanImportLookup, bool IsFramework,
       bool IsTestableDependencyLookup = false) override;
 
   bool canImportModule(ImportPath::Module named, SourceLoc loc,
@@ -561,7 +561,7 @@ class ModuleInterfaceLoader : public SerializedModuleLoaderBase {
       std::unique_ptr<llvm::MemoryBuffer> *ModuleBuffer,
       std::unique_ptr<llvm::MemoryBuffer> *ModuleDocBuffer,
       std::unique_ptr<llvm::MemoryBuffer> *ModuleSourceInfoBuffer,
-      bool SkipBuildingInterface, bool IsFramework,
+      bool IsCanImportLookup, bool IsFramework,
       bool IsTestableDependencyLookup = false) override;
 
   bool isCached(StringRef DepPath) override;

include/swift/Serialization/ScanningLoaders.h

@@ -63,7 +63,7 @@ class SwiftModuleScanner : public SerializedModuleLoaderBase {
       std::unique_ptr<llvm::MemoryBuffer> *ModuleBuffer,
       std::unique_ptr<llvm::MemoryBuffer> *ModuleDocBuffer,
       std::unique_ptr<llvm::MemoryBuffer> *ModuleSourceInfoBuffer,
-      bool SkipBuildingInterface, bool IsFramework,
+      bool IsCanImportLookup, bool IsFramework,
       bool IsTestableDependencyLookup) override;
 
   bool canImportModule(ImportPath::Module named, SourceLoc loc,

include/swift/Serialization/SerializedModuleLoader.h

@@ -103,7 +103,7 @@ class SerializedModuleLoaderBase : public ModuleLoader {
       std::unique_ptr<llvm::MemoryBuffer> *moduleBuffer,
       std::unique_ptr<llvm::MemoryBuffer> *moduleDocBuffer,
       std::unique_ptr<llvm::MemoryBuffer> *moduleSourceInfoBuffer,
-      bool skipBuildingInterface, bool isTestableDependencyLookup,
+      bool isCanImportLookup, bool isTestableDependencyLookup,
       bool &isFramework, bool &isSystemModule);
 
   /// Attempts to search the provided directory for a loadable serialized
@@ -125,8 +125,8 @@ class SerializedModuleLoaderBase : public ModuleLoader {
       std::unique_ptr<llvm::MemoryBuffer> *ModuleBuffer,
       std::unique_ptr<llvm::MemoryBuffer> *ModuleDocBuffer,
       std::unique_ptr<llvm::MemoryBuffer> *ModuleSourceInfoBuffer,
-      bool SkipBuildingInterface, bool IsFramework,
-      bool isTestableDependencyLookup = false) = 0;
+      bool IsCanImportLookup, bool IsFramework,
+      bool IsTestableDependencyLookup = false) = 0;
 
   std::error_code
   openModuleFile(
@@ -154,7 +154,8 @@ class SerializedModuleLoaderBase : public ModuleLoader {
   virtual bool maybeDiagnoseTargetMismatch(
       SourceLoc sourceLocation,
       StringRef moduleName,
-      const SerializedModuleBaseName &BaseName) {
+      const SerializedModuleBaseName &BaseName,
+      bool isCanImportLookup) {
     return false;
   }
 
@@ -278,13 +279,14 @@ class ImplicitSerializedModuleLoader : public SerializedModuleLoaderBase {
       std::unique_ptr<llvm::MemoryBuffer> *ModuleBuffer,
       std::unique_ptr<llvm::MemoryBuffer> *ModuleDocBuffer,
       std::unique_ptr<llvm::MemoryBuffer> *ModuleSourceInfoBuffer,
-      bool SkipBuildingInterface, bool IsFramework,
-      bool isTestableDependencyLookup = false) override;
+      bool IsCanImportLookup, bool IsFramework,
+      bool IsTestableDependencyLookup = false) override;
 
   bool maybeDiagnoseTargetMismatch(
       SourceLoc sourceLocation,
       StringRef moduleName,
-      const SerializedModuleBaseName &BaseName) override;
+      const SerializedModuleBaseName &BaseName,
+      bool isCanImportLookup) override;
 
 public:
   virtual ~ImplicitSerializedModuleLoader();
@@ -336,14 +338,9 @@ class MemoryBufferSerializedModuleLoader : public SerializedModuleLoaderBase {
       std::unique_ptr<llvm::MemoryBuffer> *ModuleBuffer,
       std::unique_ptr<llvm::MemoryBuffer> *ModuleDocBuffer,
       std::unique_ptr<llvm::MemoryBuffer> *ModuleSourceInfoBuffer,
-      bool SkipBuildingInterface, bool IsFramework,
+      bool IsCanImportLookup, bool IsFramework,
       bool IsTestableDependencyLookup = false) override;
 
-  bool maybeDiagnoseTargetMismatch(
-      SourceLoc sourceLocation,
-      StringRef moduleName,
-      const SerializedModuleBaseName &BaseName) override;
-
   bool BypassResilience;
 public:
   virtual ~MemoryBufferSerializedModuleLoader();

lib/Frontend/ModuleInterfaceLoader.cpp

@@ -1336,8 +1336,8 @@ std::error_code ModuleInterfaceLoader::findModuleFilesInDirectory(
     std::unique_ptr<llvm::MemoryBuffer> *ModuleBuffer,
     std::unique_ptr<llvm::MemoryBuffer> *ModuleDocBuffer,
     std::unique_ptr<llvm::MemoryBuffer> *ModuleSourceInfoBuffer,
-    bool skipBuildingInterface, bool IsFramework,
-    bool isTestableImport) {
+    bool IsCanImportLookup, bool IsFramework,
+    bool IsTestableImport) {
 
   // If running in OnlySerialized mode, ModuleInterfaceLoader
   // should not have been constructed at all.
@@ -1361,11 +1361,9 @@ std::error_code ModuleInterfaceLoader::findModuleFilesInDirectory(
   if (ModuleInterfaceSourcePath)
     ModuleInterfaceSourcePath->assign(InPath->begin(), InPath->end());
 
-  // If we've been told to skip building interfaces, we are done here and do
-  // not need to have the module actually built. For example, if we are
-  // currently answering a `canImport` query, it is enough to have found
-  // the interface.
-  if (skipBuildingInterface) {
+  // If we are currently answering a `canImport` query, it is enough to have
+  // found the interface.
+  if (IsCanImportLookup) {
     if (ModuleInterfacePath)
       ModuleInterfacePath->assign(InPath->begin(), InPath->end());
     return std::error_code();
@@ -2317,7 +2315,7 @@ bool ExplicitSwiftModuleLoader::findModule(
     std::unique_ptr<llvm::MemoryBuffer> *ModuleBuffer,
     std::unique_ptr<llvm::MemoryBuffer> *ModuleDocBuffer,
     std::unique_ptr<llvm::MemoryBuffer> *ModuleSourceInfoBuffer,
-    bool skipBuildingInterface, bool isTestableDependencyLookup,
+    bool IsCanImportLookup, bool isTestableDependencyLookup,
     bool &IsFramework, bool &IsSystemModule) {
   // Find a module with an actual, physical name on disk, in case
   // -module-alias is used (otherwise same).
@@ -2396,7 +2394,7 @@ std::error_code ExplicitSwiftModuleLoader::findModuleFilesInDirectory(
     std::unique_ptr<llvm::MemoryBuffer> *ModuleBuffer,
     std::unique_ptr<llvm::MemoryBuffer> *ModuleDocBuffer,
     std::unique_ptr<llvm::MemoryBuffer> *ModuleSourceInfoBuffer,
-    bool skipBuildingInterface, bool IsFramework,
+    bool IsCanImportLookup, bool IsFramework,
     bool IsTestableDependencyLookup) {
   llvm_unreachable("Not supported in the Explicit Swift Module Loader.");
   return std::make_error_code(std::errc::not_supported);
@@ -2674,7 +2672,7 @@ bool ExplicitCASModuleLoader::findModule(
     std::unique_ptr<llvm::MemoryBuffer> *ModuleBuffer,
     std::unique_ptr<llvm::MemoryBuffer> *ModuleDocBuffer,
     std::unique_ptr<llvm::MemoryBuffer> *ModuleSourceInfoBuffer,
-    bool skipBuildingInterface, bool isTestableDependencyLookup,
+    bool IsCanImportLookup, bool IsTestableDependencyLookup,
     bool &IsFramework, bool &IsSystemModule) {
   // Find a module with an actual, physical name on disk, in case
   // -module-alias is used (otherwise same).
@@ -2763,7 +2761,7 @@ std::error_code ExplicitCASModuleLoader::findModuleFilesInDirectory(
     std::unique_ptr<llvm::MemoryBuffer> *ModuleBuffer,
     std::unique_ptr<llvm::MemoryBuffer> *ModuleDocBuffer,
     std::unique_ptr<llvm::MemoryBuffer> *ModuleSourceInfoBuffer,
-    bool skipBuildingInterface, bool IsFramework,
+    bool IsCanImportLookup, bool IsFramework,
     bool IsTestableDependencyLookup) {
   llvm_unreachable("Not supported in the Explicit Swift Module Loader.");
   return std::make_error_code(std::errc::not_supported);

lib/Serialization/ScanningLoaders.cpp

@@ -46,7 +46,7 @@ std::error_code SwiftModuleScanner::findModuleFilesInDirectory(
     std::unique_ptr<llvm::MemoryBuffer> *ModuleBuffer,
     std::unique_ptr<llvm::MemoryBuffer> *ModuleDocBuffer,
     std::unique_ptr<llvm::MemoryBuffer> *ModuleSourceInfoBuffer,
-    bool skipBuildingInterface, bool IsFramework,
+    bool IsCanImportLookup, bool IsFramework,
     bool isTestableDependencyLookup) {
   using namespace llvm::sys;
 

lib/Serialization/SerializedModuleLoader.cpp

@@ -550,7 +550,7 @@ std::error_code ImplicitSerializedModuleLoader::findModuleFilesInDirectory(
     std::unique_ptr<llvm::MemoryBuffer> *ModuleBuffer,
     std::unique_ptr<llvm::MemoryBuffer> *ModuleDocBuffer,
     std::unique_ptr<llvm::MemoryBuffer> *ModuleSourceInfoBuffer,
-    bool skipBuildingInterface, bool IsFramework, bool IsTestableDependencyLookup) {
+    bool IsCanImportLookup, bool IsFramework, bool IsTestableDependencyLookup) {
   if (LoadMode == ModuleLoadingMode::OnlyInterface ||
       Ctx.IgnoreAdjacentModules)
     return std::make_error_code(std::errc::not_supported);
@@ -579,7 +579,8 @@ std::error_code ImplicitSerializedModuleLoader::findModuleFilesInDirectory(
 
 bool ImplicitSerializedModuleLoader::maybeDiagnoseTargetMismatch(
     SourceLoc sourceLocation, StringRef moduleName,
-    const SerializedModuleBaseName &absoluteBaseName) {
+    const SerializedModuleBaseName &absoluteBaseName,
+    bool isCanImportLookup) {
   llvm::vfs::FileSystem &fs = *Ctx.SourceMgr.getFileSystem();
 
   // Get the last component of the base name, which is the target-specific one.
@@ -614,9 +615,11 @@ bool ImplicitSerializedModuleLoader::maybeDiagnoseTargetMismatch(
     return false;
   }
 
-  Ctx.Diags.diagnose(sourceLocation, diag::sema_no_import_target, moduleName,
-                     target, foundArchs, dir);
-  return true;
+  Ctx.Diags
+      .diagnose(sourceLocation, diag::sema_no_import_target, moduleName, target,
+                foundArchs, dir)
+      .limitBehaviorIf(isCanImportLookup, DiagnosticBehavior::Warning);
+  return !isCanImportLookup;
 }
 
 SerializedModuleBaseName::SerializedModuleBaseName(
@@ -720,7 +723,7 @@ bool SerializedModuleLoaderBase::findModule(
     std::unique_ptr<llvm::MemoryBuffer> *moduleBuffer,
     std::unique_ptr<llvm::MemoryBuffer> *moduleDocBuffer,
     std::unique_ptr<llvm::MemoryBuffer> *moduleSourceInfoBuffer,
-    bool skipBuildingInterface, bool isTestableDependencyLookup,
+    bool isCanImportLookup, bool isTestableDependencyLookup,
     bool &isFramework, bool &isSystemModule) {
   // Find a module with an actual, physical name on disk, in case
   // -module-alias is used (otherwise same).
@@ -766,7 +769,7 @@ bool SerializedModuleLoaderBase::findModule(
       auto result = findModuleFilesInDirectory(
           moduleID, absoluteBaseName, moduleInterfacePath,
           moduleInterfaceSourcePath, moduleBuffer, moduleDocBuffer,
-          moduleSourceInfoBuffer, skipBuildingInterface, IsFramework,
+          moduleSourceInfoBuffer, isCanImportLookup, IsFramework,
           isTestableDependencyLookup);
       if (!result)
         return SearchResult::Found;
@@ -780,7 +783,7 @@ bool SerializedModuleLoaderBase::findModule(
     // 'std::errc::no_such_file_or_directory'.
     if (firstAbsoluteBaseName &&
         maybeDiagnoseTargetMismatch(moduleID.Loc, moduleName,
-                                    *firstAbsoluteBaseName))
+                                    *firstAbsoluteBaseName, isCanImportLookup))
       return SearchResult::Error;
 
     return SearchResult::NotFound;
@@ -838,7 +841,7 @@ bool SerializedModuleLoaderBase::findModule(
       auto result = findModuleFilesInDirectory(
           moduleID, absoluteBaseName, moduleInterfacePath,
           moduleInterfaceSourcePath, moduleBuffer, moduleDocBuffer,
-          moduleSourceInfoBuffer, skipBuildingInterface, isFramework,
+          moduleSourceInfoBuffer, isCanImportLookup, isFramework,
           isTestableDependencyLookup);
       if (!result)
         return true;
@@ -1512,7 +1515,7 @@ bool SerializedModuleLoaderBase::canImportModule(
       mID, /*moduleInterfacePath=*/nullptr, &moduleInterfaceSourcePath,
       &moduleInputBuffer,
       /*moduleDocBuffer=*/nullptr, /*moduleSourceInfoBuffer=*/nullptr,
-      /*skipBuildingInterface=*/true, isTestableDependencyLookup,
+      /*isCanImportLookup=*/true, isTestableDependencyLookup,
       isFramework, isSystemModule);
   // If we cannot find the module, don't continue.
   if (!found)
@@ -1607,7 +1610,7 @@ SerializedModuleLoaderBase::loadModule(SourceLoc importLoc,
   if (!findModule(moduleID, &moduleInterfacePath, &moduleInterfaceSourcePath,
                   &moduleInputBuffer, &moduleDocInputBuffer,
                   &moduleSourceInfoInputBuffer,
-                  /*skipBuildingInterface=*/false,
+                  /*isCanImportLookup=*/false,
                   /*isTestableDependencyLookup=*/false,
                   isFramework,
                   isSystemModule)) {
@@ -1747,7 +1750,7 @@ std::error_code MemoryBufferSerializedModuleLoader::findModuleFilesInDirectory(
     std::unique_ptr<llvm::MemoryBuffer> *ModuleBuffer,
     std::unique_ptr<llvm::MemoryBuffer> *ModuleDocBuffer,
     std::unique_ptr<llvm::MemoryBuffer> *ModuleSourceInfoBuffer,
-    bool skipBuildingInterface, bool IsFramework,
+    bool isCanImportLookup, bool IsFramework,
     bool isTestableDependencyLookup) {
   // This is a soft error instead of an llvm_unreachable because this API is
   // primarily used by LLDB which makes it more likely that unwitting changes to
@@ -1756,12 +1759,6 @@ std::error_code MemoryBufferSerializedModuleLoader::findModuleFilesInDirectory(
   return std::make_error_code(std::errc::not_supported);
 }
 
-bool MemoryBufferSerializedModuleLoader::maybeDiagnoseTargetMismatch(
-    SourceLoc sourceLocation, StringRef moduleName,
-    const SerializedModuleBaseName &absoluteBaseName) {
-  return false;
-}
-
 void SerializedModuleLoaderBase::verifyAllModules() {
 #ifndef NDEBUG
   for (const LoadedModulePair &loaded : LoadedModuleFiles)

test/Parse/ConditionalCompilation/can_import_in_inactive.swift

@@ -21,7 +21,7 @@
 #endif
 
 #if canImport(SomeModule)
-// CHECK: :[[@LINE-1]]:{{.*}}: error: could not find module 'SomeModule' for target '{{.*}}'; found: i386
+// CHECK: :[[@LINE-1]]:{{.*}}: warning: could not find module 'SomeModule' for target '{{.*}}'; found: i386
 #endif
 
 import SomeModule

test/Serialization/can-import-invalid-arch.swift

@@ -0,0 +1,13 @@
+// RUN: %empty-directory(%t)
+// RUN: mkdir %t/Foo.swiftmodule
+// RUN: touch %t/Foo.swiftmodule/i387.swiftmodule
+// RUN: touch %t/Foo.swiftmodule/ppc65.swiftmodule
+// RUN: touch %t/Foo.swiftmodule/i387.swiftdoc
+// RUN: touch %t/Foo.swiftmodule/ppc65.swiftdoc
+// RUN: %target-swift-frontend %s -typecheck -I %t 2>&1 | %FileCheck %s -DTARGET_ARCHITECTURE=%module-target-triple
+
+// CHECK: {{.*}} warning: could not find module 'Foo' for target '[[TARGET_ARCHITECTURE]]'; found: {{ppc65, i387|i387, ppc65}}, at: {{.*}}Foo.swiftmodule
+
+#if canImport(Foo)
+  import Foo
+#endif

unittests/FrontendTool/ModuleLoadingTests.cpp

@@ -131,7 +131,7 @@ class ModuleInterfaceLoaderTest : public testing::Test {
         SerializedModuleBaseName(tempDir, SerializedModuleBaseName("Library")),
         /*ModuleInterfacePath=*/nullptr, /*ModuleInterfaceSourcePath=*/nullptr,
         &moduleBuffer, &moduleDocBuffer, &moduleSourceInfoBuffer,
-        /*skipBuildingInterface*/ false, /*IsFramework*/false);
+        /*isCanImportLookup*/ false, /*IsFramework*/false);
     ASSERT_FALSE(error);
     ASSERT_FALSE(diags.hadAnyError());