sort cases based on their assigned tag indices before printing

Author: WANGJIEKE

include/swift/IRGen/IRABIDetailsProvider.h

@@ -16,6 +16,7 @@
 #include "swift/AST/Decl.h"
 #include "swift/AST/Type.h"
 #include "clang/AST/CharUnits.h"
+#include "llvm/ADT/MapVector.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallVector.h"
@@ -96,7 +97,7 @@ class IRABIDetailsProvider {
 
   /// Returns EnumElementDecls (enum cases) in their declaration order with
   /// their tag indices from the given EnumDecl
-  std::map<EnumElementDecl *, unsigned> getEnumTagMapping(EnumDecl *ED);
+  llvm::MapVector<EnumElementDecl *, unsigned> getEnumTagMapping(EnumDecl *ED);
 
 private:
   std::unique_ptr<IRABIDetailsProviderImpl> impl;

lib/IRGen/IRABIDetailsProvider.cpp

@@ -123,8 +123,8 @@ class IRABIDetailsProviderImpl {
     return {returnTy, {paramTy}};
   }
 
-  std::map<EnumElementDecl *, unsigned> getEnumTagMapping(EnumDecl *ED) {
-    std::map<EnumElementDecl *, unsigned> elements;
+  llvm::MapVector<EnumElementDecl *, unsigned> getEnumTagMapping(EnumDecl *ED) {
+    llvm::MapVector<EnumElementDecl *, unsigned> elements;
     auto &enumImplStrat = getEnumImplStrategy(
         IGM, ED->getDeclaredType()->getCanonicalType());
 
@@ -177,7 +177,7 @@ IRABIDetailsProvider::getTypeMetadataAccessFunctionSignature() {
   return impl->getTypeMetadataAccessFunctionSignature();
 }
 
-std::map<EnumElementDecl *, unsigned>
+llvm::MapVector<EnumElementDecl *, unsigned>
 IRABIDetailsProvider::getEnumTagMapping(EnumDecl *ED) {
   return impl->getEnumTagMapping(ED);
 }

lib/PrintAsClang/DeclAndTypePrinter.cpp

@@ -395,6 +395,10 @@ class DeclAndTypePrinter::Implementation
       ClangSyntaxPrinter syntaxPrinter(os);
       auto elementTagMapping =
           owningPrinter.interopContext.getIrABIDetails().getEnumTagMapping(ED);
+      // Sort cases based on their assigned tag indices
+      llvm::stable_sort(elementTagMapping, [](const auto &p1, const auto &p2) {
+        return p1.second < p2.second;
+      });
 
       if (elementTagMapping.empty()) {
         os << "\n";
@@ -417,6 +421,7 @@ class DeclAndTypePrinter::Implementation
         syntaxPrinter.printIdentifier(pair.first->getNameStr());
         os << ";\n";
       }
+      // TODO: change to Swift's fatalError when it's available in C++
       os << "      default: abort();\n";
       os << "    }\n"; // switch's closing bracket
       os << "  }\n";   // operator cases()'s closing bracket

test/Interop/SwiftToCxx/enums/swift-enum-case-functions.swift

@@ -193,18 +193,18 @@ public func checkIntDoubleOrBignum(_ x: IntDoubleOrBignum, tag: Int) -> Bool {
 
 // CHECK:      inline operator cases() const {
 // CHECK-NEXT:   switch (_getEnumTag()) {
-// CHECK-NEXT:     case 1: return cases::Paragraph;
 // CHECK-NEXT:     case 0: return cases::Char;
+// CHECK-NEXT:     case 1: return cases::Paragraph;
 // CHECK-NEXT:     case 2: return cases::Chapter;
 // CHECK-NEXT:     default: abort();
 // CHECK-NEXT:   }
 // CHECK-NEXT: }
-// CHECK-NEXT: inline bool isParagraph() const {
-// CHECK-NEXT:   return *this == cases::Paragraph;
-// CHECK-NEXT: }
 // CHECK-NEXT: inline bool isChar() const {
 // CHECK-NEXT:   return *this == cases::Char;
 // CHECK-NEXT: }
+// CHECK-NEXT: inline bool isParagraph() const {
+// CHECK-NEXT:   return *this == cases::Paragraph;
+// CHECK-NEXT: }
 // CHECK-NEXT: inline bool isChapter() const {
 // CHECK-NEXT:   return *this == cases::Chapter;
 // CHECK-NEXT: }
@@ -263,18 +263,18 @@ public func checkIntDoubleOrBignum(_ x: IntDoubleOrBignum, tag: Int) -> Bool {
 
 // CHECK:      inline operator cases() const {
 // CHECK-NEXT:   switch (_getEnumTag()) {
-// CHECK-NEXT:     case 1: return cases::NegInfinity;
 // CHECK-NEXT:     case 0: return cases::Int;
+// CHECK-NEXT:     case 1: return cases::NegInfinity;
 // CHECK-NEXT:     case 2: return cases::PosInfinity;
 // CHECK-NEXT:     default: abort();
 // CHECK-NEXT:   }
 // CHECK-NEXT: }
-// CHECK-NEXT: inline bool isNegInfinity() const {
-// CHECK-NEXT:   return *this == cases::NegInfinity;
-// CHECK-NEXT: }
 // CHECK-NEXT: inline bool isInt() const {
 // CHECK-NEXT:   return *this == cases::Int;
 // CHECK-NEXT: }
+// CHECK-NEXT: inline bool isNegInfinity() const {
+// CHECK-NEXT:   return *this == cases::NegInfinity;
+// CHECK-NEXT: }
 // CHECK-NEXT: inline bool isPosInfinity() const {
 // CHECK-NEXT:   return *this == cases::PosInfinity;
 // CHECK-NEXT: }
@@ -289,18 +289,15 @@ public func checkIntDoubleOrBignum(_ x: IntDoubleOrBignum, tag: Int) -> Bool {
 
 // CHECK:      inline operator cases() const {
 // CHECK-NEXT:   switch (_getEnumTag()) {
-// CHECK-NEXT:     case 4: return cases::Cursor;
 // CHECK-NEXT:     case 0: return cases::Plain;
 // CHECK-NEXT:     case 1: return cases::Bold;
 // CHECK-NEXT:     case 2: return cases::Underline;
 // CHECK-NEXT:     case 3: return cases::Blink;
+// CHECK-NEXT:     case 4: return cases::Cursor;
 // CHECK-NEXT:     case 5: return cases::Empty;
 // CHECK-NEXT:     default: abort();
 // CHECK-NEXT:   }
 // CHECK-NEXT: }
-// CHECK-NEXT: inline bool isCursor() const {
-// CHECK-NEXT:   return *this == cases::Cursor;
-// CHECK-NEXT: }
 // CHECK-NEXT: inline bool isPlain() const {
 // CHECK-NEXT:   return *this == cases::Plain;
 // CHECK-NEXT: }
@@ -313,6 +310,9 @@ public func checkIntDoubleOrBignum(_ x: IntDoubleOrBignum, tag: Int) -> Bool {
 // CHECK-NEXT: inline bool isBlink() const {
 // CHECK-NEXT:   return *this == cases::Blink;
 // CHECK-NEXT: }
+// CHECK-NEXT: inline bool isCursor() const {
+// CHECK-NEXT:   return *this == cases::Cursor;
+// CHECK-NEXT: }
 // CHECK-NEXT: inline bool isEmpty() const {
 // CHECK-NEXT:   return *this == cases::Empty;
 // CHECK-NEXT: }

test/Interop/SwiftToCxx/enums/swift-enum-cases-in-cxx.swift

@@ -23,8 +23,8 @@ public enum EnumCaseIsCxxKeyword {
 
 // CHECK: class EnumCaseIsCxxKeyword final {
 // CHECK:      enum class cases {
-// CHECK-NEXT:   first,
 // CHECK-NEXT:   second,
+// CHECK-NEXT:   first,
 // CHECK-NEXT:   const_
 // CHECK-NEXT: };