[APINotes] Handle global functions in namespaces

rdar://113403829

Author: egorzhdan

clang/include/clang/APINotes/APINotesReader.h

@@ -182,7 +182,8 @@ class APINotesReader {
   /// \param name The name of the global function.
   ///
   /// \returns information about the global function, if known.
-  VersionedInfo<GlobalFunctionInfo> lookupGlobalFunction(llvm::StringRef name);
+  VersionedInfo<GlobalFunctionInfo>
+  lookupGlobalFunction(std::optional<Context> context, llvm::StringRef name);
 
   /// Look for information regarding the given enumerator.
   ///

clang/include/clang/APINotes/APINotesWriter.h

@@ -92,7 +92,8 @@ class APINotesWriter {
   ///
   /// \param name The name of this global function.
   /// \param info Information about this global function.
-  void addGlobalFunction(llvm::StringRef name, const GlobalFunctionInfo &info,
+  void addGlobalFunction(std::optional<Context> context, llvm::StringRef name,
+                         const GlobalFunctionInfo &info,
                          llvm::VersionTuple swiftVersion);
 
   /// Add information about an enumerator.

clang/lib/APINotes/APINotesReader.cpp

@@ -450,12 +450,15 @@ namespace {
 
   /// Used to deserialize the on-disk global function table.
   class GlobalFunctionTableInfo
-    : public VersionedTableInfo<GlobalFunctionTableInfo, unsigned,
-                                GlobalFunctionInfo> {
+      : public VersionedTableInfo<GlobalFunctionTableInfo,
+                                  std::tuple<uint32_t, uint8_t, uint32_t>,
+                                  GlobalFunctionInfo> {
   public:
     static internal_key_type ReadKey(const uint8_t *data, unsigned length) {
+      auto contextID = endian::readNext<uint32_t, little, unaligned>(data);
+      auto contextKind = endian::readNext<uint8_t, little, unaligned>(data);
       auto nameID = endian::readNext<uint32_t, little, unaligned>(data);
-      return nameID;
+      return {contextID, contextKind, nameID};
     }
 
     static GlobalFunctionInfo readUnversioned(internal_key_type key,
@@ -1950,7 +1953,8 @@ auto APINotesReader::lookupGlobalVariable(
   return { Impl.SwiftVersion, *known };
 }
 
-auto APINotesReader::lookupGlobalFunction(StringRef name)
+auto APINotesReader::lookupGlobalFunction(std::optional<Context> context,
+                                          StringRef name)
     -> VersionedInfo<GlobalFunctionInfo> {
   if (!Impl.GlobalFunctionTable)
     return None;
@@ -1959,7 +1963,13 @@ auto APINotesReader::lookupGlobalFunction(StringRef name)
   if (!nameID)
     return None;
 
-  auto known = Impl.GlobalFunctionTable->find(*nameID);
+  std::tuple<uint32_t, uint8_t, uint32_t> key;
+  if (context)
+    key = {context->id.Value, (uint8_t)context->kind, *nameID};
+  else
+    key = {-1, (uint8_t)-1, *nameID};
+
+  auto known = Impl.GlobalFunctionTable->find(key);
   if (known == Impl.GlobalFunctionTable->end())
     return None;
 

clang/lib/APINotes/APINotesWriter.cpp

@@ -101,8 +101,8 @@ class APINotesWriter::Implementation {
 
   /// Information about global functions.
   ///
-  /// Indexed by the identifier ID.
-  llvm::DenseMap<unsigned,
+  /// Indexed by the context ID, contextKind, identifier ID.
+  llvm::DenseMap<std::tuple<uint32_t, uint8_t, uint32_t>,
                  llvm::SmallVector<std::pair<VersionTuple, GlobalFunctionInfo>,
                                    1>>
     GlobalFunctions;
@@ -957,16 +957,18 @@ namespace {
   /// Used to serialize the on-disk global function table.
   class GlobalFunctionTableInfo
     : public VersionedTableInfo<GlobalFunctionTableInfo,
-                                unsigned,
+                                std::tuple<uint32_t, uint8_t, uint32_t>,
                                 GlobalFunctionInfo> {
   public:
     unsigned getKeyLength(key_type_ref) {
-      return sizeof(uint32_t);
+      return sizeof(uint32_t) + sizeof(uint8_t) + sizeof(uint32_t);
     }
 
     void EmitKey(raw_ostream &out, key_type_ref key, unsigned len) {
       endian::Writer writer(out, little);
-      writer.write<uint32_t>(key);
+      writer.write<uint32_t>(std::get<0>(key));
+      writer.write<uint8_t>(std::get<1>(key));
+      writer.write<uint32_t>(std::get<2>(key));
     }
 
     unsigned getUnversionedInfoSize(const GlobalFunctionInfo &info) {
@@ -1326,11 +1328,17 @@ void APINotesWriter::addGlobalVariable(llvm::StringRef name,
   Impl.GlobalVariables[variableID].push_back({swiftVersion, info});
 }
 
-void APINotesWriter::addGlobalFunction(llvm::StringRef name,
+void APINotesWriter::addGlobalFunction(std::optional<Context> context,
+                                       llvm::StringRef name,
                                        const GlobalFunctionInfo &info,
                                        VersionTuple swiftVersion) {
   IdentifierID nameID = Impl.getIdentifier(name);
-  Impl.GlobalFunctions[nameID].push_back({swiftVersion, info});
+  std::tuple<uint32_t, uint8_t, uint32_t> key;
+  if (context)
+    key = {context->id.Value, (uint8_t)context->kind, nameID};
+  else
+    key = {-1, (uint8_t)-1, nameID};
+  Impl.GlobalFunctions[key].push_back({swiftVersion, info});
 }
 
 void APINotesWriter::addEnumConstant(llvm::StringRef name,

clang/lib/APINotes/APINotesYAMLCompiler.cpp

@@ -1097,7 +1097,7 @@ namespace {
                            info, function.Name);
         info.ResultType = std::string(function.ResultType);
         info.setRetainCountConvention(function.RetainCountConvention);
-        Writer->addGlobalFunction(function.Name, info, swiftVersion);
+        Writer->addGlobalFunction(context, function.Name, info, swiftVersion);
       }
 
       // Write all enumerators.

clang/lib/Sema/SemaAPINotes.cpp

@@ -858,7 +858,8 @@ void Sema::ProcessAPINotes(Decl *D) {
     if (auto FD = dyn_cast<FunctionDecl>(D)) {
       if (FD->getDeclName().isIdentifier()) {
         for (auto Reader : APINotes.findAPINotes(D->getLocation())) {
-          auto Info = Reader->lookupGlobalFunction(FD->getName());
+          auto Info =
+              Reader->lookupGlobalFunction(APINotesContext, FD->getName());
           ProcessVersionedAPINotes(*this, FD, Info);
         }
       }

clang/test/APINotes/Inputs/Frameworks/CXXInteropKit.framework/Headers/CXXInteropKit.apinotes

@@ -10,18 +10,27 @@ Classes:
 Enumerators:
 - Name: SomeClassRed
   SwiftName: red
+Functions:
+- Name: funcInNamespace
+  SwiftName: inWrongContext()
 Tags:
 - Name: NSSomeEnumOptions
   SwiftName: SomeEnum.Options
 - Name: char_box
   SwiftName: InWrongContext
 Namespaces:
 - Name: Namespace1
+  Functions:
+  - Name: funcInNamespace
+    SwiftName: swiftFuncInNamespace()
   Tags:
   - Name: char_box
     SwiftName: CharBox
   Namespaces:
   - Name: Nested1
+    Functions:
+    - Name: funcInNestedNamespace
+      SwiftName: swiftFuncInNestedNamespace(_:)
     Tags:
     - Name: char_box
       SwiftName: NestedCharBox

clang/test/APINotes/Inputs/Frameworks/CXXInteropKit.framework/Headers/CXXInteropKit.h

@@ -24,9 +24,11 @@ typedef NS_OPTIONS(NSUInteger, NSSomeEnumOptions) {
 
 namespace Namespace1 {
 struct char_box { char c; };
+void funcInNamespace();
 
 namespace Nested1 {
 struct char_box { char c; };
+void funcInNestedNamespace(int i);
 
 namespace Namespace1 {
 struct char_box { char c; };