[Macros] Import owning and supplemental modules when processing macro signature.

The macro signature can depend on both the owning module and any
supplemental signature modules. Create import declarations for each of these
prior to import resolution of the macro signature buffer.

Author: DougGregor

lib/Sema/TypeCheckMacros.cpp

@@ -102,7 +102,9 @@ static Optional<std::pair<GenericSignature, Type>>
 getMacroSignature(
     ModuleDecl *mod, Identifier macroName,
     Optional<StringRef> genericSignature,
-    StringRef typeSignature
+    StringRef typeSignature,
+    ModuleDecl *owningModule,
+    ArrayRef<ModuleDecl *> supplementalImportModules
 ) {
   // Form a buffer containing the macro signature context.
   ASTContext &ctx = mod->getASTContext();
@@ -140,6 +142,21 @@ getMacroSignature(
   if (!decl)
     return None;
 
+  /// Add an import to the module.
+  auto addImport = [&](ModuleDecl *importedModule) {
+    ImportPath::Builder importPath;
+    importPath.push_back(importedModule->getName(), SourceLoc());
+    auto importDecl = ImportDecl::create(
+        ctx, macroSourceFile, SourceLoc(), ImportKind::Module,
+        SourceLoc(), importPath.get());
+    importDecl->setImplicit();
+    macroSourceFile->addTopLevelDecl(importDecl);
+  };
+  addImport(owningModule);
+  std::for_each(supplementalImportModules.begin(),
+                supplementalImportModules.end(),
+                addImport);
+
   // Make sure imports are resolved in this file.
   performImportResolution(*macroSourceFile);
 
@@ -183,7 +200,8 @@ static MacroDecl *createMacro(
 
   // Get the type signature of the macro.
   auto signature = getMacroSignature(
-      mod, macroName, genericSignature, typeSignature);
+      mod, macroName, genericSignature, typeSignature, owningModule,
+      supplementalImportModules);
   if (!signature) {
     // FIXME: Swap in ErrorTypes, perhaps?
     return nullptr;

test/Macros/Inputs/macro_definition.swift

@@ -130,7 +130,7 @@ struct ColorLiteralMacro: _CompilerPlugin {
   }
 
   static func _owningModule() -> (UnsafePointer<UInt8>, count: Int) {
-    var swiftModule = "Swift"
+    var swiftModule = "ColorLib"
     return swiftModule.withUTF8 { buffer in
       let result = UnsafeMutablePointer<UInt8>.allocate(capacity: buffer.count)
       result.initialize(from: buffer.baseAddress!, count: buffer.count)
@@ -191,20 +191,15 @@ struct HSVColorLiteralMacro: _CompilerPlugin {
   }
 
   static func _genericSignature() -> (UnsafePointer<UInt8>?, count: Int) {
-    var genSig = "<T>"
-    return genSig.withUTF8 { buffer in
-      let result = UnsafeMutablePointer<UInt8>.allocate(capacity: buffer.count)
-      result.initialize(from: buffer.baseAddress!, count: buffer.count)
-      return (UnsafePointer(result), count: buffer.count)
-    }
+    return (nil, count: 0)
   }
 
   static func _typeSignature() -> (UnsafePointer<UInt8>, count: Int) {
     var typeSig =
       """
       (
        hue hue: Float, saturation saturation: Float, value value: Float
-      ) -> T
+      ) -> MyColor
       """
     return typeSig.withUTF8 { buffer in
       let result = UnsafeMutablePointer<UInt8>.allocate(capacity: buffer.count)
@@ -214,7 +209,7 @@ struct HSVColorLiteralMacro: _CompilerPlugin {
   }
 
   static func _owningModule() -> (UnsafePointer<UInt8>, count: Int) {
-    var swiftModule = "Swift"
+    var swiftModule = "ColorLib"
     return swiftModule.withUTF8 { buffer in
       let result = UnsafeMutablePointer<UInt8>.allocate(capacity: buffer.count)
       result.initialize(from: buffer.baseAddress!, count: buffer.count)

test/Macros/macro_plugin.swift

@@ -1,12 +1,14 @@
 // RUN: %empty-directory(%t)
 // RUN: %target-build-swift -Xfrontend -disable-availability-checking -I%platform-module-dir/../.. -L%platform-dylib-dir/../.. -emit-library -emit-library-path=%t/%target-library-name(MacroDefinition) -working-directory=%t -module-name=MacroDefinition %S/Inputs/macro_definition.swift
-// RUN: %target-swift-frontend -L%platform-dylib-dir/../.. -enable-experimental-feature Macros -load-plugin-library %t/%target-library-name(MacroDefinition) -disable-availability-checking -dump-ast -primary-file %s | %FileCheck %s
+// RUN: %target-swift-frontend -emit-module -o %t %S/Inputs/ColorLib.swift
+// RUN: %target-swift-frontend -L%platform-dylib-dir/../.. -enable-experimental-feature Macros -load-plugin-library %t/%target-library-name(MacroDefinition) -I %t -disable-availability-checking -dump-ast -primary-file %s | %FileCheck %s
 
 // FIXME: Swift parser is not enabled on Linux CI yet.
 // REQUIRES: OS=macosx
 
 // rdar://102160067
 // UNSUPPORTED: CPU=arm64e
+import ColorLib
 
 let _ = #customStringify(1.byteSwapped + 2.advanced(by: 10))
 
@@ -35,11 +37,6 @@ let _ = #customStringify(["a", "b", "c"] + ["d", "e", "f"])
 // CHECK:     (binary_expr type='[String]'
 // CHECK:     (string_literal_expr type='String'
 
-struct MyColor: _ExpressibleByColorLiteral {
-  init(_colorLiteralRed red: Float, green: Float, blue: Float, alpha: Float) { }
-  init(_colorLiteralHue hue: Float, saturation: Float, value: Float) { }
-}
-
 // CHECK: (macro_expansion_expr type='MyColor' {{.*}} name=customColorLiteral
 let _: MyColor = #customColorLiteral(red: 0.5, green: 0.5, blue: 0.2, alpha: 0.9)