ABI checker: use dedicated mangled name field to diagnose mangled name changes

Author: nkcsgexi

include/swift/APIDigester/ModuleAnalyzerNodes.h

@@ -360,12 +360,13 @@ class SDKNodeDecl: public SDKNode {
   Optional<uint8_t> FixedBinaryOrder;
   PlatformIntroVersion introVersions;
   StringRef ObjCName;
-
+  mutable Optional<StringRef> demangledName;
 protected:
   SDKNodeDecl(SDKNodeInitInfo Info, SDKNodeKind Kind);
   virtual ~SDKNodeDecl() = default;
 public:
   StringRef getUsr() const { return Usr; }
+  StringRef getDemangledName() const;
   StringRef getLocation() const { return Location; }
   StringRef getModuleName() const {return ModuleName;}
   StringRef getHeaderName() const;

include/swift/AST/USRGeneration.h

@@ -63,8 +63,11 @@ bool printExtensionUSR(const ExtensionDecl *ED, raw_ostream &OS);
 /// \returns true if it failed, false on success.
 bool printDeclUSR(const Decl *D, raw_ostream &OS);
 
-/// Demangle a mangle-name-based USR to a human readable name.
-std::string demangleUSR(StringRef mangled);
+/// Get mangled name from a USR.
+std::string getMangledNameFromUSR(StringRef usr);
+
+/// Demangle a mangled name to a human readable name.
+std::string demangleMangledName(StringRef mangled);
 
 } // namespace ide
 } // namespace swift

lib/APIDigester/ModuleAnalyzerNodes.cpp

@@ -817,6 +817,19 @@ static bool hasSameParameterFlags(const SDKNodeType *Left, const SDKNodeType *Ri
   return true;
 }
 
+StringRef SDKNodeDecl::getDemangledName() const {
+  if (demangledName.hasValue()) {
+    return *demangledName;
+  }
+  std::string mangled = MangledName.str();
+  if (mangled.empty()) {
+    mangled = getMangledNameFromUSR(Usr);
+  }
+  demangledName = Ctx.buffer(demangleMangledName(mangled));
+  assert(demangledName.hasValue());
+  return *demangledName;
+}
+
 static bool isSDKNodeEqual(SDKContext &Ctx, const SDKNode &L, const SDKNode &R) {
   auto *LeftAlias = dyn_cast<SDKNodeTypeAlias>(&L);
   auto *RightAlias = dyn_cast<SDKNodeTypeAlias>(&R);
@@ -948,7 +961,7 @@ static bool isSDKNodeEqual(SDKContext &Ctx, const SDKNode &L, const SDKNode &R)
         if (Left->getFixedBinaryOrder() != Right->getFixedBinaryOrder())
           return false;
       }
-      if (Left->getUsr() != Right->getUsr())
+      if (Left->getDemangledName() != Right->getDemangledName())
         return false;
       LLVM_FALLTHROUGH;
     }
@@ -2582,9 +2595,10 @@ void swift::ide::api::SDKNodeDecl::diagnose(SDKNode *Right) {
       emitDiag(Loc, diag::decl_reorder, getFixedBinaryOrder(),
                RD->getFixedBinaryOrder());
     }
-    if (getUsr() != RD->getUsr()) {
-      auto left = demangleUSR(getUsr());
-      auto right = demangleUSR(RD->getUsr());
+    {
+      // diagnose mangled name change.
+      auto left = getDemangledName();
+      auto right = RD->getDemangledName();
       if (left != right) {
         emitDiag(Loc, diag::demangled_name_changed, left, right);
       }

lib/AST/USRGeneration.cpp

@@ -256,16 +256,23 @@ swift::USRGenerationRequest::evaluate(Evaluator &evaluator,
   return NewMangler.mangleDeclAsUSR(D, getUSRSpacePrefix());
 }
 
-std::string ide::demangleUSR(StringRef mangled) {
-  if (mangled.startswith(getUSRSpacePrefix())) {
-    mangled = mangled.substr(getUSRSpacePrefix().size());
+std::string ide::getMangledNameFromUSR(StringRef usr) {
+  if (usr.startswith(getUSRSpacePrefix())) {
+    usr = usr.substr(getUSRSpacePrefix().size());
   }
   SmallString<128> buffer;
   buffer += "$s";
-  buffer += mangled;
-  mangled = buffer.str();
+  buffer += usr;
+  return buffer.str().str();
+}
+
+std::string ide::demangleMangledName(StringRef mangled) {
   Demangler Dem;
-  return nodeToString(Dem.demangleSymbol(mangled));
+  std::string result = nodeToString(Dem.demangleSymbol(mangled));
+  if (result.empty()) {
+    return mangled.str();
+  }
+  return result;
 }
 
 std::string

test/api-digester/Inputs/cake_baseline/cake.swift

@@ -232,3 +232,6 @@ open class AddingNewDesignatedInit {
     print(foo)
   }
 }
+
+@_silgen_name("sil_name_before")
+public func silGenNameGiven() {}

test/api-digester/Inputs/cake_current/cake.swift

@@ -252,3 +252,6 @@ public extension Float {
 }
 
 infix operator <==> : AssignmentPrecedence
+
+@_silgen_name("sil_name_after")
+public func silGenNameGiven() {}

test/api-digester/Outputs/Cake-abi.txt

@@ -10,6 +10,7 @@ cake: Func S1.foo5(x:y:) has mangled name changing from 'cake.S1.foo5(x: Swift.I
 cake: Func Somestruct2.foo1(_:) has mangled name changing from 'static cake.Somestruct2.foo1(cake.C3) -> ()' to 'static cake.NSSomestruct2.foo1(cake.C1) -> ()'
 cake: Func ownershipChange(_:_:) has mangled name changing from 'cake.ownershipChange(inout Swift.Int, __shared Swift.Int) -> ()' to 'cake.ownershipChange(Swift.Int, __owned Swift.Int) -> ()'
 cake: Func returnFunctionTypeOwnershipChange() has mangled name changing from 'cake.returnFunctionTypeOwnershipChange() -> (cake.C1) -> ()' to 'cake.returnFunctionTypeOwnershipChange() -> (__owned cake.C1) -> ()'
+cake: Func silGenNameGiven() has mangled name changing from 'sil_name_before' to 'sil_name_after'
 cake: Protocol P3 has generic signature change from <Self : cake.P1, Self : cake.P2> to <Self : cake.P1, Self : cake.P4>
 cake: Struct Somestruct2 has mangled name changing from 'cake.Somestruct2' to 'cake.NSSomestruct2'