[clang][CodeComplete] Use HeuristicResolver to resolve pointee types (#121315)

Fixes clangd/clangd#810

Author: HighCommander4

clang/include/clang/Sema/SemaCodeCompletion.h

@@ -23,6 +23,7 @@
 #include "clang/Sema/CodeCompleteConsumer.h"
 #include "clang/Sema/DeclSpec.h"
 #include "clang/Sema/Designator.h"
+#include "clang/Sema/HeuristicResolver.h"
 #include "clang/Sema/Ownership.h"
 #include "clang/Sema/SemaBase.h"
 #include "llvm/ADT/StringRef.h"
@@ -43,6 +44,7 @@ class SemaCodeCompletion : public SemaBase {
 
   /// Code-completion consumer.
   CodeCompleteConsumer *CodeCompleter;
+  HeuristicResolver Resolver;
 
   /// Describes the context in which code completion occurs.
   enum ParserCompletionContext {

clang/lib/Sema/SemaCodeComplete.cpp

@@ -34,6 +34,7 @@
 #include "clang/Sema/CodeCompleteConsumer.h"
 #include "clang/Sema/DeclSpec.h"
 #include "clang/Sema/Designator.h"
+#include "clang/Sema/HeuristicResolver.h"
 #include "clang/Sema/Lookup.h"
 #include "clang/Sema/Overload.h"
 #include "clang/Sema/ParsedAttr.h"
@@ -5861,8 +5862,10 @@ void SemaCodeCompletion::CodeCompleteMemberReferenceExpr(
   enum CodeCompletionContext::Kind contextKind;
 
   if (IsArrow) {
-    if (const auto *Ptr = ConvertedBaseType->getAs<PointerType>())
-      ConvertedBaseType = Ptr->getPointeeType();
+    if (QualType PointeeType = Resolver.getPointeeType(ConvertedBaseType);
+        !PointeeType.isNull()) {
+      ConvertedBaseType = PointeeType;
+    }
   }
 
   if (IsArrow) {
@@ -5899,8 +5902,9 @@ void SemaCodeCompletion::CodeCompleteMemberReferenceExpr(
     ExprValueKind BaseKind = Base->getValueKind();
 
     if (IsArrow) {
-      if (const PointerType *Ptr = BaseType->getAs<PointerType>()) {
-        BaseType = Ptr->getPointeeType();
+      if (QualType PointeeType = Resolver.getPointeeType(BaseType);
+          !PointeeType.isNull()) {
+        BaseType = PointeeType;
         BaseKind = VK_LValue;
       } else if (BaseType->isObjCObjectPointerType() ||
                  BaseType->isTemplateTypeParmType()) {
@@ -10472,4 +10476,5 @@ void SemaCodeCompletion::GatherGlobalCodeCompletions(
 
 SemaCodeCompletion::SemaCodeCompletion(Sema &S,
                                        CodeCompleteConsumer *CompletionConsumer)
-    : SemaBase(S), CodeCompleter(CompletionConsumer) {}
+    : SemaBase(S), CodeCompleter(CompletionConsumer),
+      Resolver(S.getASTContext()) {}

clang/test/CodeCompletion/member-access.cpp

@@ -384,3 +384,20 @@ void Foo() {
 // RUN: %clang_cc1 -fsyntax-only -code-completion-at=%s:382:5 %s -o - | FileCheck -check-prefix=CHECK-DEREF-DEPENDENT %s
 // CHECK-DEREF-DEPENDENT: [#void#]Add()
 }
+
+namespace dependent_smart_pointer {
+template <typename T>
+struct smart_pointer {
+  T* operator->();
+};
+
+template <typename T>
+struct node {
+  smart_pointer<node<T>> next;
+  void foo() {
+    next->next;
+    // RUN: %clang_cc1 -fsyntax-only -code-completion-at=%s:398:11 %s -o - | FileCheck -check-prefix=CHECK-DEPENDENT-SMARTPTR %s
+    // CHECK-DEPENDENT-SMARTPTR: [#smart_pointer<node<T>>#]next
+  }
+};
+}