StringOptimization: bug fixes

Fix some bugs in the optimization and in the test files.

rdar://problem/66283894

Author: eeckstein

lib/AST/ASTMangler.cpp

@@ -534,7 +534,7 @@ std::string ASTMangler::mangleTypeForDebugger(Type Ty, const DeclContext *DC) {
 }
 
 std::string ASTMangler::mangleTypeForTypeName(Type type) {
-  beginMangling();
+  beginManglingWithoutPrefix();
   appendType(type);
   return finalize();
 }

lib/SILOptimizer/Transforms/StringOptimization.cpp

@@ -199,6 +199,32 @@ bool StringOptimization::optimizeStringAppend(ApplyInst *appendCall,
   return false;
 }
 
+/// Checks if the demangling tree contains any node which prevents constant
+/// folding of the type name.
+static bool containsProblematicNode(Demangle::Node *node, bool qualified) {
+  switch (node->getKind()) {
+    case Demangle::Node::Kind::LocalDeclName:
+      // The printing of contexts for local types is completely different
+      // in the runtime. Don't constant fold if we need to print the context.
+      if (qualified)
+        return true;
+      break;
+    case Demangle::Node::Kind::Class:
+      // ObjC class names are not derived from the mangling but from the
+      // ObjC runtime. We cannot constant fold this.
+      if (node->getChild(0)->getText() == "__C")
+        return true;
+      break;
+    default:
+      break;
+  }
+  for (Demangle::Node *child : *node) {
+    if (containsProblematicNode(child, qualified))
+      return true;
+  }
+  return false;
+}
+
 /// Try to replace a _typeName() call with a constant string if the type is
 /// statically known.
 bool StringOptimization::optimizeTypeName(ApplyInst *typeNameCall) {
@@ -217,20 +243,29 @@ bool StringOptimization::optimizeTypeName(ApplyInst *typeNameCall) {
     return false;
 
   // Usually the "qualified" parameter of _typeName() is a constant boolean.
-  Optional<int> isQualified = getIntConstant(typeNameCall->getArgument(1));
-  if (!isQualified)
+  Optional<int> isQualifiedOpt = getIntConstant(typeNameCall->getArgument(1));
+  if (!isQualifiedOpt)
     return false;
+  bool isQualified = isQualifiedOpt.getValue();
 
   // Create the constant type string by mangling + demangling.
   Mangle::ASTMangler mangler;
   std::string mangledTypeName = mangler.mangleTypeForTypeName(ty);
 
   Demangle::DemangleOptions options;
   options.PrintForTypeName = true;
-  options.QualifyEntities = (isQualified.getValue() != 0);
-  std::string typeStr = Demangle::demangleSymbolAsString(mangledTypeName,
-                                                         options);
-  
+  options.DisplayLocalNameContexts = false;
+  options.QualifyEntities = isQualified;
+
+  Demangle::Context ctx;
+  Demangle::NodePointer root = ctx.demangleTypeAsNode(mangledTypeName);
+  if (!root || containsProblematicNode(root, isQualified))
+    return false;
+
+  std::string typeStr = nodeToString(root, options);
+  if (typeStr.empty())
+    return false;
+
   ApplyInst *stringInit = createStringInit(typeStr, typeNameCall);
   if (!stringInit)
     return false;

test/SILOptimizer/string_optimization.swift

@@ -6,6 +6,10 @@
 
 // REQUIRES: executable_test,swift_stdlib_no_asserts
 
+#if _runtime(_ObjC)
+import Foundation
+#endif
+
 struct Outer {
   struct Inner { }
 }
@@ -50,17 +54,60 @@ public func testQualifiedTypeName() -> String {
   return _typeName(Outer.Inner.self, qualified: true)
 }
 
+// CHECK-LABEL: sil [noinline] @$s4test0A20UnqualifiedLocalTypeSSyF
+// CHECK-NOT: apply
+// CHECK-NOT: bb1
+// CHECK: } // end sil function '$s4test0A20UnqualifiedLocalTypeSSyF'
+@inline(never)
+public func testUnqualifiedLocalType() -> String {
+  struct LocalStruct { }
+  return _typeName(LocalStruct.self, qualified: false)
+}
+
+// CHECK-LABEL: sil [noinline] @$s4test0A18QualifiedLocalTypeSSyF
+// CHECK:    [[F:%[0-9]+]] = function_ref @$ss9_typeName_9qualifiedSSypXp_SbtF
+// CHECK:    apply [[F]]
+// CHECK: } // end sil function '$s4test0A18QualifiedLocalTypeSSyF'
+@inline(never)
+public func testQualifiedLocalType() -> String {
+  struct LocalStruct { }
+  return _typeName(LocalStruct.self, qualified: true)
+}
+
+#if _runtime(_ObjC)
+@inline(never)
+public func testObjcClassName(qualified: Bool) -> String {
+  return _typeName(NSObject.self, qualified: qualified)
+}
+#endif
+
 @inline(never)
 func printEmbeeded(_ s: String) {
   print("<\(s)>")
 }
 
 // CHECK-OUTPUT: <-Inner+>
 printEmbeeded(testTypeNameInterpolation())
+
 // CHECK-OUTPUT: <-Array<Int> is cool+>
 printEmbeeded(testFoldCompleteInterpolation())
+
 // CHECK-OUTPUT: <Inner>
 printEmbeeded(testUnqualifiedTypeName())
+
 // CHECK-OUTPUT: <test.Outer.Inner>
 printEmbeeded(testQualifiedTypeName())
 
+// CHECK-OUTPUT: <LocalStruct>
+printEmbeeded(testUnqualifiedLocalType())
+
+// CHECK-OUTPUT: <test.(unknown context at {{.*}}).LocalStruct>
+printEmbeeded(testQualifiedLocalType())
+
+#if _runtime(_ObjC)
+// CHECK-OUTPUT: <NSObject>
+printEmbeeded(testObjcClassName(qualified: false))
+// CHECK-OUTPUT: <NSObject>
+printEmbeeded(testObjcClassName(qualified: true))
+#endif
+

test/stdlib/TypeName.swift

@@ -1,7 +1,9 @@
 // RUN: %empty-directory(%t)
 // RUN: %target-build-swift -O -module-name=main %s -o %t/O.out
+// RUN: %target-codesign %t/O.out
 // RUN: %target-run %t/O.out
 // RUN: %target-build-swift -Onone -module-name=main %s -o %t/Onone.out
+// RUN: %target-codesign %t/Onone.out
 // RUN: %target-run %t/Onone.out
 
 // REQUIRES: executable_test

test/stdlib/TypeNameInterpolation.swift

@@ -3,8 +3,10 @@
 
 // RUN: %empty-directory(%t)
 // RUN: %target-build-swift -O -module-name=test %s -o %t/O.out
+// RUN: %target-codesign %t/O.out
 // RUN: %target-run %t/O.out
 // RUN: %target-build-swift -Onone -module-name=test %s -o %t/Onone.out
+// RUN: %target-codesign %t/Onone.out
 // RUN: %target-run %t/Onone.out
 
 // REQUIRES: executable_test

validation-test/stdlib/StringUTF8.swift

@@ -25,7 +25,12 @@ extension String {
   var isFastUTF8: Bool {
     return withFastUTF8IfAvailable({ _ in return 0 }) != nil
   }
-  mutating func makeNative() { self += "" }
+
+  // Prevent that the optimizer removes 'self += ""' in makeNative()
+  @inline(never)
+  static func emptyString() -> String { return "" }
+
+  mutating func makeNative() { self += String.emptyString() }
 
   var isASCII: Bool { return utf8.allSatisfy { $0 < 0x7f } }
 }