[Migrator] Handle function decl renames. rdar://31766131 (#9157)

include/swift/Migrator/EditorAdapter.h

@@ -108,6 +108,7 @@ public:
   bool remove(SourceLoc TokenLoc);
   bool remove(SourceRange TokenRange);
   bool replace(SourceRange TokenRange, StringRef Text);
+  bool replaceToken(SourceLoc TokenLoc, StringRef Text);
   bool replaceWithInner(SourceRange TokenRange, SourceRange TokenInnerRange);
 
   /// Return the batched edits encountered so far.

lib/Migrator/EditorAdapter.cpp

@@ -148,3 +148,8 @@ bool EditorAdapter::replaceWithInner(SourceRange TokenRange,
   auto CharInnerRange = Lexer::getCharSourceRangeFromSourceRange(SwiftSrcMgr, TokenInnerRange);
   return replaceWithInner(CharRange, CharInnerRange);
 }
+
+bool EditorAdapter::replaceToken(SourceLoc TokenLoc, StringRef Text) {
+  return replace(Lexer::getTokenAtLocation(SwiftSrcMgr, TokenLoc).getRange(),
+    Text);
+}

lib/Migrator/SyntacticMigratorPass.cpp

@@ -389,10 +389,41 @@ struct SyntacticMigratorPass::Implementation : public SourceEntityWalker {
     return true;
   }
 
+  void handleFuncDeclRename(AbstractFunctionDecl *AFD,
+                            CharSourceRange NameRange) {
+    bool IgnoreBase = false;
+    if (auto View = getFuncRename(AFD, IgnoreBase)) {
+      if (!IgnoreBase)
+        Editor.replace(NameRange, View.base());
+      unsigned Index = 0;
+      for (auto PL : AFD->getParameterLists()) {
+        for (auto *PD : *PL) {
+          if (Index == View.argSize())
+            break;
+          // Self parameter should not be updated.
+          if (PD->isSelfParameter())
+            continue;
+          StringRef NewArg = View.args()[Index++];
+          auto ArgLoc = PD->getArgumentNameLoc();
+
+          // If the argument name is not specified, add the argument name before
+          // the paramter name.
+          if (ArgLoc.isInvalid())
+            Editor.insertBefore(PD->getNameLoc(),
+                                (llvm::Twine(NewArg) + " ").str());
+          else
+            // Otherwise, replace the argument name directly.
+            Editor.replaceToken(ArgLoc, NewArg);
+        }
+      }
+    }
+  }
+
   bool walkToDeclPre(Decl *D, CharSourceRange Range) override {
     if (D->isImplicit())
       return true;
     if (auto *AFD = dyn_cast<AbstractFunctionDecl>(D)) {
+      handleFuncDeclRename(AFD, Range);
       for (auto *Item: getRelatedDiffItems(AFD)) {
         if (auto *DiffItem = dyn_cast<CommonDiffItem>(Item)) {
           if (!DiffItem->isTypeChange())

test/Migrator/API.json

@@ -346,5 +346,27 @@
     "RightUsr": "",
     "RightComment": "",
     "ModuleName": "Cities"
+  },
+  {
+    "DiffItemKind": "CommonDiffItem",
+    "NodeKind": "Function",
+    "NodeAnnotation": "Rename",
+    "ChildIndex": "0",
+    "LeftUsr": "s:6CitiesAAC10mooloolabayAB1x_ABSg1ytF",
+    "LeftComment": "",
+    "RightUsr": "",
+    "RightComment": "newMooloolaba(newX:newY:)",
+    "ModuleName": "Cities"
+  },
+    {
+    "DiffItemKind": "CommonDiffItem",
+    "NodeKind": "Function",
+    "NodeAnnotation": "Rename",
+    "ChildIndex": "0",
+    "LeftUsr": "s:6Cities04MoreA0P14setZooLocationySi1x_Si1ySi1ztF",
+    "LeftComment": "",
+    "RightUsr": "",
+    "RightComment": "setZooLocationNew(newX:newY:newZ:)",
+    "ModuleName": "Cities"
   }
 ]

test/Migrator/Inputs/cities.swift

@@ -15,3 +15,7 @@ public protocol ExtraCities {
   func blibli(x: (String?, String) -> String!)
   func currimundi(x: (Int, (Int, Int))!)
 }
+
+public protocol MoreCities {
+  func setZooLocation(x: Int, y: Int, z: Int)
+}

test/Migrator/rename-func-decl.swift

@@ -0,0 +1,11 @@
+// REQUIRES: objc_interop
+// RUN: rm -rf %t.mod && mkdir -p %t.mod
+// RUN: %target-swift-frontend -emit-module -o %t.mod/cities.swiftmodule %S/Inputs/cities.swift -module-name Cities -parse-as-library
+// RUN: rm -rf %t && mkdir -p %t && %target-swift-frontend -c -update-code -disable-migrator-fixits -primary-file %s  -I %t.mod -api-diff-data-file %S/API.json -emit-migrated-file-path %t/rename-func-decl.swift.result -o %t/rename-func-decl.swift.remap -o /dev/null
+// RUN: diff -u %S/rename-func-decl.swift.expected %t/rename-func-decl.swift.result
+
+import Cities
+
+class MyCities : MoreCities {
+  func setZooLocation(x ix: Int, y iy: Int, z iz: Int) {}
+}

test/Migrator/rename-func-decl.swift.expected

@@ -0,0 +1,11 @@
+// REQUIRES: objc_interop
+// RUN: rm -rf %t.mod && mkdir -p %t.mod
+// RUN: %target-swift-frontend -emit-module -o %t.mod/cities.swiftmodule %S/Inputs/cities.swift -module-name Cities -parse-as-library
+// RUN: rm -rf %t && mkdir -p %t && %target-swift-frontend -c -update-code -disable-migrator-fixits -primary-file %s  -I %t.mod -api-diff-data-file %S/API.json -emit-migrated-file-path %t/rename-func-decl.swift.result -o %t/rename-func-decl.swift.remap -o /dev/null
+// RUN: diff -u %S/rename-func-decl.swift.expected %t/rename-func-decl.swift.result
+
+import Cities
+
+class MyCities : MoreCities {
+  func setZooLocationNew(newX ix: Int, newY iy: Int, newZ iz: Int) {}
+}

test/Migrator/wrap_optional.swift.expected

@@ -9,7 +9,7 @@ import Cities
 class MyCities : Cities {
   override init?(x: Int?) { super.init(x: x) }
   override init?(y: Int) { super.init(y: y) }
-  override func mooloolaba(x: Cities?, y: Cities) {}
+  override func newMooloolaba(newX x: Cities?, newY y: Cities) {}
   override func toowoomba(x: [Cities?], y: [Cities?]) {}
   override func mareeba(x: [String? : Cities], y: [Int : Cities]) {}
 }