print C's abort in default branch

Author: WANGJIEKE

lib/PrintAsClang/DeclAndTypePrinter.cpp

@@ -413,14 +413,11 @@ class DeclAndTypePrinter::Implementation
       os << "  inline operator cases() const {\n";
       os << "    switch (_getEnumTag()) {\n";
       for (const auto &pair : elementTagMapping) {
-        if (pair == *elementTagMapping.crbegin()) {
-          os << "      case " << pair.second << ": default: return cases::";
-        } else {
-          os << "      case " << pair.second << ": return cases::";
-        }
+        os << "      case " << pair.second << ": return cases::";
         syntaxPrinter.printIdentifier(pair.first->getNameStr());
         os << ";\n";
       }
+      os << "      default: abort();\n";
       os << "    }\n"; // switch's closing bracket
       os << "  }\n";   // operator cases()'s closing bracket
 

test/Inputs/clang-importer-sdk/usr/include/stdlib.h

@@ -16,4 +16,6 @@ void free(void *);
 ldiv_t ldiv(long int, long int);
 lldiv_t lldiv(long long int, long long int);
 
+_Noreturn void abort(void);
+
 #endif // SDK_STDLIB_H

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

@@ -169,7 +169,8 @@ public func checkIntDoubleOrBignum(_ x: IntDoubleOrBignum, tag: Int) -> Bool {
 // CHECK-NEXT:   switch (_getEnumTag()) {
 // CHECK-NEXT:     case 0: return cases::one;
 // CHECK-NEXT:     case 1: return cases::two;
-// CHECK-NEXT:     case 2: default: return cases::three;
+// CHECK-NEXT:     case 2: return cases::three;
+// CHECK-NEXT:     default: abort();
 // CHECK-NEXT:   }
 // CHECK-NEXT: }
 // CHECK-NEXT: inline bool isOne() const {
@@ -194,7 +195,8 @@ public func checkIntDoubleOrBignum(_ x: IntDoubleOrBignum, tag: Int) -> Bool {
 // CHECK-NEXT:   switch (_getEnumTag()) {
 // CHECK-NEXT:     case 1: return cases::Paragraph;
 // CHECK-NEXT:     case 0: return cases::Char;
-// CHECK-NEXT:     case 2: default: return cases::Chapter;
+// CHECK-NEXT:     case 2: return cases::Chapter;
+// CHECK-NEXT:     default: abort();
 // CHECK-NEXT:   }
 // CHECK-NEXT: }
 // CHECK-NEXT: inline bool isParagraph() const {
@@ -217,7 +219,8 @@ public func checkIntDoubleOrBignum(_ x: IntDoubleOrBignum, tag: Int) -> Bool {
 
 // CHECK:      inline operator cases() const {
 // CHECK-NEXT:   switch (_getEnumTag()) {
-// CHECK-NEXT:     case 0: default: return cases::one;
+// CHECK-NEXT:     case 0: return cases::one;
+// CHECK-NEXT:     default: abort();
 // CHECK-NEXT:   }
 // CHECK-NEXT: }
 // CHECK-NEXT: inline bool isOne() const {
@@ -236,7 +239,8 @@ public func checkIntDoubleOrBignum(_ x: IntDoubleOrBignum, tag: Int) -> Bool {
 // CHECK-NEXT:   switch (_getEnumTag()) {
 // CHECK-NEXT:     case 0: return cases::Int;
 // CHECK-NEXT:     case 1: return cases::Double;
-// CHECK-NEXT:     case 2: default: return cases::Bignum;
+// CHECK-NEXT:     case 2: return cases::Bignum;
+// CHECK-NEXT:     default: abort();
 // CHECK-NEXT:   }
 // CHECK-NEXT: }
 // CHECK-NEXT: inline bool isInt() const {
@@ -261,7 +265,8 @@ public func checkIntDoubleOrBignum(_ x: IntDoubleOrBignum, tag: Int) -> Bool {
 // CHECK-NEXT:   switch (_getEnumTag()) {
 // CHECK-NEXT:     case 1: return cases::NegInfinity;
 // CHECK-NEXT:     case 0: return cases::Int;
-// CHECK-NEXT:     case 2: default: return cases::PosInfinity;
+// CHECK-NEXT:     case 2: return cases::PosInfinity;
+// CHECK-NEXT:     default: abort();
 // CHECK-NEXT:   }
 // CHECK-NEXT: }
 // CHECK-NEXT: inline bool isNegInfinity() const {
@@ -289,7 +294,8 @@ public func checkIntDoubleOrBignum(_ x: IntDoubleOrBignum, tag: Int) -> Bool {
 // CHECK-NEXT:     case 1: return cases::Bold;
 // CHECK-NEXT:     case 2: return cases::Underline;
 // CHECK-NEXT:     case 3: return cases::Blink;
-// CHECK-NEXT:     case 5: default: return cases::Empty;
+// CHECK-NEXT:     case 5: return cases::Empty;
+// CHECK-NEXT:     default: abort();
 // CHECK-NEXT:   }
 // CHECK-NEXT: }
 // CHECK-NEXT: inline bool isCursor() const {