Move getRealImportPath to cpp

Remove unnecessary setter
Update tests

include/swift/AST/Decl.h

@@ -1143,9 +1143,6 @@ class ImportDecl final : public Decl,
 
   ImportDecl(DeclContext *DC, SourceLoc ImportLoc, ImportKind K,
              SourceLoc KindLoc, ImportPath Path);
-  // Sets the real module name corresponding to this import decl in
-  // case module aliasing is used. Called in \c ImportDecl::create.
-  void setRealModuleName(Identifier name) { RealModuleName = name; };
 public:
   static ImportDecl *create(ASTContext &C, DeclContext *DC,
                             SourceLoc ImportLoc, ImportKind Kind,
@@ -1193,23 +1190,7 @@ public:
   ///          '-module-alias Foo=Bar', this import path will include 'Bar'. This
   ///          return value may be owned by \p scratch, so it should not be used
   ///          after \p scratch is destroyed.
-  ImportPath getRealImportPath(ImportPath::Builder &scratch) const {
-    assert(scratch.empty() && "non-empty scratch ImportPath::Builder?");
-    auto path = getImportPath();
-    if (RealModuleName.empty())
-      return path;
-
-    for (auto elem : path) {
-      if (scratch.empty()) {
-        // Add the real module name instead of its alias
-        scratch.push_back(RealModuleName);
-      } else {
-        // Add the rest if any (access path elements)
-        scratch.push_back(elem.Item);
-      }
-    }
-    return scratch.get();
-  }
+  ImportPath getRealImportPath(ImportPath::Builder &scratch) const;
 
   /// Retrieves the part of the import path that contains the module name,
   /// as written in the source code.
@@ -1238,7 +1219,6 @@ public:
   ///          after \p scratch is destroyed.
   ImportPath::Module getRealModulePath(ImportPath::Builder &scratch) const {
     return getRealImportPath(scratch).getModulePath(getImportKind());
-    return getImportPath().getModulePath(getImportKind());
   }
 
   ImportPath::Access getAccessPath() const {

lib/AST/Decl.cpp

@@ -1066,8 +1066,10 @@ ImportDecl *ImportDecl::create(ASTContext &Ctx, DeclContext *DC,
   auto D = new (ptr) ImportDecl(DC, ImportLoc, Kind, KindLoc, Path);
   if (ClangN)
     D->setClangNode(ClangN);
-  auto realName = Ctx.getRealModuleName(Path.front().Item);
-  D->setRealModuleName(realName);
+  auto realNameIfExists = Ctx.getRealModuleName(Path.front().Item), ModuleAliasLookupOption::realFromAlias);
+  if (!realNameIfExists.empty()) {
+    D->RealModuleName = realNameIfExists;
+  }
   return D;
 }
 
@@ -1160,6 +1162,24 @@ ImportDecl::findBestImportKind(ArrayRef<ValueDecl *> Decls) {
   return FirstKind;
 }
 
+ImportPath ImportDecl::getRealImportPath(ImportPath::Builder &scratch) const {
+  assert(scratch.empty() && "scratch ImportPath::Builder must be initially empty");
+  auto path = getImportPath();
+  if (RealModuleName.empty())
+    return path;
+
+  for (auto elem : path) {
+    if (scratch.empty()) {
+      // Add the real module name instead of its alias
+      scratch.push_back(RealModuleName);
+    } else {
+      // Add the rest if any (access path elements)
+      scratch.push_back(elem.Item);
+    }
+  }
+  return scratch.get();
+}
+
 ArrayRef<ValueDecl *> ImportDecl::getDecls() const {
   // If this isn't a scoped import, there's nothing to do.
   if (getImportKind() == ImportKind::Module)

test/Frontend/module-alias-emit-imported-modules.swift

@@ -9,12 +9,17 @@
 // RUN: test -f %t/AppleLogging.swiftmodule
 
 /// Verify emitted imported modules contains AppleLogging as a module name
-// RUN: %target-swift-frontend -emit-imported-modules %t/FileLib.swift -module-alias XLogging=AppleLogging -I %t > %t/result.output
+// RUN: %target-swift-frontend -emit-imported-modules %t/FileLib1.swift -module-alias XLogging=AppleLogging -I %t > %t/result1.output
 
-// RUN: %FileCheck %s -input-file %t/result.output -check-prefix CHECK-AST
-// CHECK-AST: AppleLogging
-// RUN: not %FileCheck %s -input-file %t/result.output -check-prefix CHECK-NOT-AST
-// CHECK-NOT-AST: XLogging
+// RUN: %FileCheck %s -input-file %t/result1.output -check-prefix CHECK-AST1
+// CHECK-AST1-NOT: XLogging
+// CHECK-AST1: AppleLogging
+
+// RUN: %target-swift-frontend -emit-imported-modules %t/FileLib2.swift -module-alias XLogging=AppleLogging -I %t > %t/result2.output
+
+// RUN: %FileCheck %s -input-file %t/result2.output -check-prefix CHECK-AST2
+// CHECK-AST2-NOT: XLogging
+// CHECK-AST2: AppleLogging
 
 
 // BEGIN FileLogging.swift
@@ -25,7 +30,7 @@ public func setup() -> XLogging.Logger? {
   return Logger()
 }
 
-// BEGIN FileLib.swift
+// BEGIN FileLib1.swift
 import XLogging
 
 public func start() -> XLogging.Logger? {
@@ -35,3 +40,9 @@ public func start() -> XLogging.Logger? {
 public func end(_ arg: XLogging.Logger) {
 }
 
+// BEGIN FileLib2.swift
+import struct XLogging.Logger
+
+public func start() -> XLogging.Logger? {
+  return XLogging.Logger()
+}

test/Frontend/module-alias-import-attrs.swift

@@ -1,4 +1,3 @@
-
 /// Test various import attributes with module aliasing.
 ///
 /// Module 'Lib' imports module 'XLogging' via module aliasing and with various import attributes.
@@ -24,9 +23,8 @@
 // RUN: test -f %t/Lib2.swiftmodule
 // RUN: llvm-bcanalyzer -dump %t/Lib2.swiftmodule > %t/Lib2.dump.txt
 // RUN: %FileCheck -check-prefix=CHECK-REAL-NAME %s < %t/Lib2.dump.txt
+// CHECK-REAL-NAME-NOT: XLogging
 // CHECK-REAL-NAME: AppleLogging
-// RUN: not %FileCheck -check-prefix=CHECK-ALIAS %s < %t/Lib2.dump.txt
-// CHECK-ALIAS: XLogging
 
 /// Test @_implementationOnly: Should fail
 // RUN: not %target-swift-frontend -module-name Lib3 %t/FileLib3.swift -module-alias XLogging=AppleLogging -I %t -emit-module -emit-module-path %t/Lib3.swiftmodule 2> %t/result-Lib3.output
@@ -43,9 +41,8 @@
 // RUN: %target-swift-frontend -module-name Lib4 %t/FileLib4.swift -module-alias XLogging=AppleLoggingEnablePrivate -I %t -emit-module -emit-module-path %t/Lib4.swiftmodule
 // RUN: llvm-bcanalyzer -dump %t/Lib4.swiftmodule > %t/Lib4.dump.txt
 // RUN: %FileCheck -check-prefix=CHECK-REAL-NAME4 %s < %t/Lib4.dump.txt
+// CHECK-REAL-NAME4-NOT: XLogging
 // CHECK-REAL-NAME4: AppleLoggingEnablePrivate
-// RUN: not %FileCheck -check-prefix=CHECK-ALIAS4 %s < %t/Lib4.dump.txt
-// CHECK-ALIAS4: XLogging
 
 /// Test @testable: Should pass
 
@@ -56,25 +53,22 @@
 // RUN: %target-swift-frontend -module-name Lib5 %t/FileLib5.swift -module-alias XLogging=AppleLoggingEnableTesting -I %t -emit-module -emit-module-path %t/Lib5.swiftmodule
 // RUN: llvm-bcanalyzer -dump %t/Lib5.swiftmodule > %t/Lib5.dump.txt
 // RUN: %FileCheck -check-prefix=CHECK-REAL-NAME5 %s < %t/Lib5.dump.txt
+// CHECK-REAL-NAME5-NOT: XLogging
 // CHECK-REAL-NAME5: AppleLoggingEnableTesting
-// RUN: not %FileCheck -check-prefix=CHECK-ALIAS5 %s < %t/Lib5.dump.txt
-// CHECK-ALIAS5: XLogging
 
 /// Test import struct: Should pass with correct module name reference
 // RUN: %target-swift-frontend -module-name Lib6 %t/FileLib6.swift -module-alias XLogging=AppleLogging -I %t -emit-module -emit-module-path %t/Lib6.swiftmodule -c -o %t/Lib6.o
 // RUN: llvm-nm --defined-only %t/Lib6.o > %t/Lib6.dump.txt
 // RUN: %FileCheck -check-prefix=CHECK-REAL-NAME6 %s < %t/Lib6.dump.txt
+// CHECK-REAL-NAME6-NOT: XLogging
 // CHECK-REAL-NAME6: s4Lib65start12AppleLogging6LoggerVyF
-// RUN: not %FileCheck -check-prefix=CHECK-ALIAS6 %s < %t/Lib6.dump.txt
-// CHECK-ALIAS6: XLogging
 
 /// Test canImport
 // RUN: %target-swift-frontend -module-name Lib7 %t/FileLib7.swift -module-alias XLogging=AppleLogging -I %t -emit-module -emit-module-path %t/Lib7.swiftmodule -Rmodule-loading 2> %t/Lib7.dump.txt
 
 // RUN: %FileCheck -check-prefix=CHECK-LOAD %s < %t/Lib7.dump.txt
+// CHECK-LOAD-NOT: XLogging.swiftmodule
 // CHECK-LOAD: AppleLogging.swiftmodule
-// RUN: not %FileCheck -check-prefix=CHECK-NOT-LOAD %s < %t/Lib7.dump.txt
-// CHECK-NOT-LOAD: XLogging.swiftmodule
 
 /// Test @_exported: Should pass with correct module name reference
 // RUN: %target-swift-frontend -module-name Lib %t/FileLib.swift -module-alias XLogging=AppleLogging -I %t -emit-module -emit-module-path %t/Lib.swiftmodule
@@ -84,9 +78,8 @@
 
 // RUN: llvm-nm --defined-only %t/User.o > %t/User.dump.txt
 // RUN: %FileCheck -check-prefix=CHECK-REAL-NAME-USER %s < %t/User.dump.txt
+// CHECK-REAL-NAME-USER-NOT: XLogging
 // CHECK-REAL-NAME-USER: s4User04MainA0V3use12AppleLogging6LoggerVyF
-// RUN: not %FileCheck -check-prefix=CHECK-ALIAS-USER %s < %t/User.dump.txt
-// CHECK-ALIAS-USER: XLogging
 
 // BEGIN FileLogging.swift
 public struct Logger {