[cxx-interop] Do not auto-complete unsafe underscored methods, part 2

Previous patch removed unsafe C++ methods from the module interface, but not from auto-completion results.

rdar://103252957

Author: egorzhdan

include/swift/ClangImporter/ClangImporter.h

@@ -532,6 +532,8 @@ class ClangImporter final : public ClangModuleLoader {
 
   bool isCXXMethodMutating(const clang::CXXMethodDecl *method) override;
 
+  bool isUnsafeCXXMethod(const FuncDecl *func);
+
   bool isAnnotatedWith(const clang::CXXMethodDecl *method, StringRef attr);
 
   /// Find the lookup table that corresponds to the given Clang module.

lib/ClangImporter/ClangImporter.cpp

@@ -6199,6 +6199,21 @@ bool ClangImporter::isCXXMethodMutating(const clang::CXXMethodDecl *method) {
   return false;
 }
 
+bool ClangImporter::isUnsafeCXXMethod(const FuncDecl *func) {
+  if (!func->hasClangNode())
+    return false;
+  auto clangDecl = func->getClangNode().getAsDecl();
+  if (!clangDecl)
+    return false;
+  auto cxxMethod = dyn_cast<clang::CXXMethodDecl>(clangDecl);
+  if (!cxxMethod)
+    return false;
+  if (!func->hasName())
+    return false;
+  auto id = func->getBaseIdentifier().str();
+  return id.startswith("__") && id.endswith("Unsafe");
+}
+
 bool ClangImporter::isAnnotatedWith(const clang::CXXMethodDecl *method,
                                     StringRef attr) {
   return method->hasAttrs() &&

lib/IDE/CompletionLookup.cpp

@@ -1471,6 +1471,10 @@ void CompletionLookup::addMethodCall(const FuncDecl *FD,
       Builder.addFlair(CodeCompletionFlairBit::ExpressionSpecific);
   };
 
+  // Do not add imported C++ methods that are treated as unsafe in Swift.
+  if (Importer->isUnsafeCXXMethod(FD))
+    return;
+
   if (!AFT || IsImplicitlyCurriedInstanceMethod) {
     addMethodImpl();
   } else {

test/Interop/Cxx/class/type-classification-completion.swift

@@ -1,9 +1,13 @@
-// RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=METHOD -I %S/Inputs | %FileCheck %s -check-prefix=CHECK-METHOD
+// RUN: %target-swift-ide-test -code-completion -enable-experimental-cxx-interop -source-filename %s -code-completion-token=METHOD -I %S/Inputs | %FileCheck %s -check-prefix=CHECK-METHOD
 
 import TypeClassification
 
 func foo(x: HasMethodThatReturnsIterator) {
   x.#^METHOD^#
 }
+// CHECK-METHOD: Begin completions
 // CHECK-METHOD-NOT: getIterator
+// CHECK-METHOD-NOT: Decl[InstanceMethod]/CurrNominal:   getIterator
 // CHECK-METHOD-NOT: __getIteratorUnsafe
+// CHECK-METHOD-NOT: Decl[InstanceMethod]/CurrNominal:   __getIteratorUnsafe
+// CHECK-METHOD: End completions