IRGen: support static linking on Windows

include/swift/AST/Decl.h

@@ -588,7 +588,10 @@ class alignas(1 << DeclAlignInBits) Decl {
     HasAnyUnavailableValues : 1
   );
 
-  SWIFT_INLINE_BITFIELD(ModuleDecl, TypeDecl, 1+1+1+1+1+1+1+1+1+1,
+  SWIFT_INLINE_BITFIELD(ModuleDecl, TypeDecl, 1+1+1+1+1+1+1+1+1+1+1,
+    /// If the module is compiled as static library.
+    StaticLibrary : 1,
+
     /// If the module was or is being compiled with `-enable-testing`.
     TestingEnabled : 1,
 

include/swift/AST/Module.h

@@ -424,6 +424,14 @@ class ModuleDecl : public DeclContext, public TypeDecl {
     DebugClient = R;
   }
 
+  /// Returns true if this module is compiled as static library.
+  bool isStaticLibrary() const {
+    return Bits.ModuleDecl.StaticLibrary;
+  }
+  void setStaticLibrary(bool isStatic = true) {
+    Bits.ModuleDecl.StaticLibrary = isStatic;
+  }
+
   /// Returns true if this module was or is being compiled for testing.
   bool isTestingEnabled() const {
     return Bits.ModuleDecl.TestingEnabled;

include/swift/Frontend/FrontendOptions.h

@@ -314,6 +314,9 @@ class FrontendOptions {
   /// skip nodes entirely, depending on the errors involved.
   bool AllowModuleWithCompilerErrors = false;
 
+  /// True if the "-static" option is set.
+  bool Static = false;
+
   /// The different modes for validating TBD against the LLVM IR.
   enum class TBDValidationMode {
     Default,        ///< Do the default validation for the current platform.

include/swift/Serialization/SerializationOptions.h

@@ -136,6 +136,7 @@ namespace swift {
     bool SerializeOptionsForDebugging = false;
     bool IsSIB = false;
     bool DisableCrossModuleIncrementalInfo = false;
+    bool StaticLibrary = false;
   };
 
 } // end namespace swift

include/swift/Serialization/Validation.h

@@ -98,6 +98,7 @@ class ExtendedValidationInfo {
   struct {
     unsigned ArePrivateImportsEnabled : 1;
     unsigned IsSIB : 1;
+    unsigned IsStaticLibrary: 1;
     unsigned IsTestable : 1;
     unsigned ResilienceStrategy : 2;
     unsigned IsImplicitDynamicEnabled : 1;
@@ -131,6 +132,10 @@ class ExtendedValidationInfo {
   void setImplicitDynamicEnabled(bool val) {
     Bits.IsImplicitDynamicEnabled = val;
   }
+  bool isStaticLibrary() const { return Bits.IsStaticLibrary; }
+  void setIsStaticLibrary(bool val) {
+    Bits.IsStaticLibrary = val;
+  }
   bool isTestable() const { return Bits.IsTestable; }
   void setIsTestable(bool val) {
     Bits.IsTestable = val;

lib/AST/Module.cpp

@@ -475,6 +475,7 @@ ModuleDecl::ModuleDecl(Identifier name, ASTContext &ctx,
 
   setAccess(AccessLevel::Public);
 
+  Bits.ModuleDecl.StaticLibrary = 0;
   Bits.ModuleDecl.TestingEnabled = 0;
   Bits.ModuleDecl.FailedToLoad = 0;
   Bits.ModuleDecl.RawResilienceStrategy = 0;

lib/Frontend/ArgsToFrontendOptionsConverter.cpp

@@ -258,6 +258,8 @@ bool ArgsToFrontendOptionsConverter::convert(
 
   Opts.SkipInheritedDocs = Args.hasArg(OPT_skip_inherited_docs);
 
+  Opts.Static = Args.hasArg(OPT_static);
+
   return false;
 }
 

lib/Frontend/Frontend.cpp

@@ -182,6 +182,8 @@ SerializationOptions CompilerInvocation::computeSerializationOptions(
   serializationOpts.DisableCrossModuleIncrementalInfo =
       opts.DisableCrossModuleIncrementalBuild;
 
+  serializationOpts.StaticLibrary = opts.Static;
+
   return serializationOpts;
 }
 

lib/IRGen/GenDecl.cpp

@@ -2030,7 +2030,7 @@ void irgen::updateLinkageForDefinition(IRGenModule &IGM,
   bool isKnownLocal = entity.isAlwaysSharedLinkage();
   if (const auto *DC = entity.getDeclContextForEmission())
     if (const auto *MD = DC->getParentModule())
-      isKnownLocal = IGM.getSwiftModule() == MD;
+      isKnownLocal = IGM.getSwiftModule() == MD || MD->isStaticLibrary();
 
   auto IRL =
       getIRLinkage(linkInfo, entity.getLinkage(ForDefinition),
@@ -2059,7 +2059,7 @@ LinkInfo LinkInfo::get(const UniversalLinkageInfo &linkInfo,
   bool isKnownLocal = entity.isAlwaysSharedLinkage();
   if (const auto *DC = entity.getDeclContextForEmission())
     if (const auto *MD = DC->getParentModule())
-      isKnownLocal = MD == swiftModule;
+      isKnownLocal = MD == swiftModule || MD->isStaticLibrary();
 
   entity.mangle(result.Name);
   bool weakImported = entity.isWeakImported(swiftModule);
@@ -2074,6 +2074,8 @@ LinkInfo LinkInfo::get(const UniversalLinkageInfo &linkInfo, StringRef name,
                        bool isWeakImported) {
   LinkInfo result;
 
+  // TODO(compnerd) handle this properly
+
   result.Name += name;
   result.IRL = getIRLinkage(linkInfo, linkage, isDefinition, isWeakImported);
   result.ForDefinition = isDefinition;

lib/IRGen/GenProto.cpp

@@ -1117,9 +1117,15 @@ class DirectConformanceInfo : public ConformanceInfo {
 
   llvm::Constant *tryGetConstantTable(IRGenModule &IGM,
                                       CanType conformingType) const override {
-    if (IGM.getOptions().LazyInitializeProtocolConformances &&
-        RootConformance->getDeclContext()->getParentModule() != IGM.getSwiftModule())
-      return nullptr;
+    if (IGM.getOptions().LazyInitializeProtocolConformances) {
+      const auto *MD = RootConformance->getDeclContext()->getParentModule();
+      // If the protocol conformance is defined in the current module or the
+      // module will be statically linked, then we can statically initialize the
+      // conformance as we know that the protocol conformance is guaranteed to
+      // be present.
+      if (!(MD == IGM.getSwiftModule() || MD->isStaticLibrary()))
+        return nullptr;
+    }
     return IGM.getAddrOfWitnessTable(RootConformance);
   }
 };

lib/Serialization/ModuleFile.h

@@ -461,6 +461,11 @@ class ModuleFile
     return Core->Bits.IsTestable;
   }
 
+  /// Whether this module is compiled as static library.
+  bool isStaticLibrary() const {
+    return Core->Bits.IsStaticLibrary;
+  }
+
   /// Whether the module is resilient. ('-enable-library-evolution')
   ResilienceStrategy getResilienceStrategy() const {
     return ResilienceStrategy(Core->Bits.ResilienceStrategy);

lib/Serialization/ModuleFileSharedCore.cpp

@@ -131,6 +131,9 @@ static bool readOptionsBlock(llvm::BitstreamCursor &cursor,
       options_block::IsSIBLayout::readRecord(scratch, IsSIB);
       extendedInfo.setIsSIB(IsSIB);
       break;
+    case options_block::IS_STATIC_LIBRARY:
+      extendedInfo.setIsStaticLibrary(true);
+      break;
     case options_block::IS_TESTABLE:
       extendedInfo.setIsTestable(true);
       break;
@@ -1180,6 +1183,7 @@ ModuleFileSharedCore::ModuleFileSharedCore(
       UserModuleVersion = info.userModuleVersion;
       Bits.ArePrivateImportsEnabled = extInfo.arePrivateImportsEnabled();
       Bits.IsSIB = extInfo.isSIB();
+      Bits.IsStaticLibrary = extInfo.isStaticLibrary();
       Bits.IsTestable = extInfo.isTestable();
       Bits.ResilienceStrategy = unsigned(extInfo.getResilienceStrategy());
       Bits.IsImplicitDynamicEnabled = extInfo.isImplicitDynamicEnabled();

lib/Serialization/ModuleFileSharedCore.h

@@ -326,6 +326,9 @@ class ModuleFileSharedCore {
     /// Whether this module file is actually a .sib file.
     unsigned IsSIB: 1;
 
+    /// Whether this module is compiled as static library.
+    unsigned IsStaticLibrary: 1;
+
     /// Whether this module file is compiled with '-enable-testing'.
     unsigned IsTestable : 1;
 

lib/Serialization/ModuleFormat.h

@@ -56,7 +56,7 @@ const uint16_t SWIFTMODULE_VERSION_MAJOR = 0;
 /// describe what change you made. The content of this comment isn't important;
 /// it just ensures a conflict if two people change the module format.
 /// Don't worry about adhering to the 80-column limit for this line.
-const uint16_t SWIFTMODULE_VERSION_MINOR = 612; // add user-defined module version
+const uint16_t SWIFTMODULE_VERSION_MINOR = 613; // isStaticLibrary option
 
 /// A standard hash seed used for all string hashes in a serialized module.
 ///
@@ -788,6 +788,7 @@ namespace options_block {
     SDK_PATH = 1,
     XCC,
     IS_SIB,
+    IS_STATIC_LIBRARY,
     IS_TESTABLE,
     RESILIENCE_STRATEGY,
     ARE_PRIVATE_IMPORTS_ENABLED,
@@ -811,6 +812,10 @@ namespace options_block {
     BCFixed<1> // Is this an intermediate file?
   >;
 
+  using IsStaticLibraryLayout = BCRecordLayout<
+    IS_STATIC_LIBRARY
+  >;
+
   using IsTestableLayout = BCRecordLayout<
     IS_TESTABLE
   >;

lib/Serialization/Serialization.cpp

@@ -981,6 +981,11 @@ void Serializer::writeHeader(const SerializationOptions &options) {
       options_block::IsSIBLayout IsSIB(Out);
       IsSIB.emit(ScratchRecord, options.IsSIB);
 
+      if (options.StaticLibrary) {
+        options_block::IsStaticLibraryLayout IsStaticLibrary(Out);
+        IsStaticLibrary.emit(ScratchRecord);
+      }
+
       if (M->isTestingEnabled()) {
         options_block::IsTestableLayout IsTestable(Out);
         IsTestable.emit(ScratchRecord);

lib/Serialization/SerializedModuleLoader.cpp

@@ -715,6 +715,7 @@ LoadedFile *SerializedModuleLoaderBase::loadAST(
 
     // We've loaded the file. Now try to bring it into the AST.
     fileUnit = new (Ctx) SerializedASTFile(M, *loadedModuleFile);
+    M.setStaticLibrary(loadedModuleFile->isStaticLibrary());
     if (loadedModuleFile->isTestable())
       M.setTestingEnabled();
     if (loadedModuleFile->arePrivateImportsEnabled())

test/IRGen/windows-linking.swift

@@ -0,0 +1,65 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-swift-frontend -target x86_64-unknown-windows-msvc -parse-as-library -parse-stdlib -static -emit-module -emit-module-path %t/module.swiftmodule -module-name module -DMODULE %s
+// RUN: %target-swift-frontend -target x86_64-unknown-windows-msvc -parse-as-library -parse-stdlib -S -emit-ir %s -module-name main -o - -I%t | %FileCheck %s -check-prefix CHECK-STATIC
+// RUN: %target-swift-frontend -target x86_64-unknown-windows-msvc -parse-as-library -parse-stdlib -emit-module -emit-module-path %t/module.swiftmodule -module-name module -DMODULE %s
+// RUN: %target-swift-frontend -target x86_64-unknown-windows-msvc -parse-as-library -parse-stdlib -S -emit-ir %s -module-name main -o - -I%t | %FileCheck %s -check-prefix CHECK-SHARED
+
+#if MODULE
+
+public struct S {}
+public var value: S {
+  S()
+}
+
+public func f(_ s: S) {}
+
+public protocol P {
+}
+
+public enum E: P {
+}
+
+#else
+
+import module
+
+protocol Q: P {
+}
+
+extension E: Q {
+}
+
+@main
+struct Entry {
+  public static func main() {
+    f(value)
+  }
+}
+
+#endif
+
+
+// Ensure that static linking does not mark the entries as being indirected
+// through the IAT.
+
+// CHECK-STATIC:       @"$s6module1EO4main1QADWP" = hidden constant [2 x i8*] [
+// CHECK-STATIC-SAME:      i8* bitcast (%swift.protocol_conformance_descriptor* @"$s6module1EO4main1QADMc" to i8*),
+// CHECK-STATIC-SAME:      i8* bitcast (i8** @"$s6module1EOAA1PAAWP" to i8*)
+// CHECK-STATIC-SAME:  ]
+
+// CHECK-STATIC: declare swiftcc void @"$s6module5valueAA1SVvg"()
+
+// CHECK-STATIC: declare swiftcc void @"$s6module1fyyAA1SVF"()
+
+
+// Ensure that shared linking does mark the functions as being indirected
+// through the IAT.
+
+// CHECK-SHARED:       @"$s6module1EO4main1QADWP" = hidden constant [2 x i8*] [
+// CHECK-SHARED-SAME:      i8* bitcast (%swift.protocol_conformance_descriptor* @"$s6module1EO4main1QADMc" to i8*),
+// CHECK-SHARED-SAME:      i8* null
+// CHECK-SHARED-SAME:  ]
+
+// CHECK-SHARED: declare dllimport swiftcc void @"$s6module5valueAA1SVvg"()
+
+// CHECK-SHARED: declare dllimport swiftcc void @"$s6module1fyyAA1SVF"()