[clang-tools-extra] [clangd] Fix crash with null check for Token at Loc (PR #94528)

[Utkarsh Saxena via cfe-commits]

https://github.com/usx95 created https://github.com/llvm/llvm-project/pull/94528

None

>From b13a663ae347649a3bcf9d6e381a5fbbfdc9ea4b Mon Sep 17 00:00:00 2001
From: Utkarsh Saxena <usx at google.com>
Date: Wed, 5 Jun 2024 19:48:48 +0000
Subject: [PATCH] [clangd] Fix crash with null check for Token at Loc

---
 clang-tools-extra/clangd/XRefs.cpp            | 32 +++++++++++--------
 .../clangd/unittests/XRefsTests.cpp           | 14 +++++++-
 2 files changed, 31 insertions(+), 15 deletions(-)

diff --git a/clang-tools-extra/clangd/XRefs.cpp b/clang-tools-extra/clangd/XRefs.cpp
index cd909266489a8..f52228e599591 100644
--- a/clang-tools-extra/clangd/XRefs.cpp
+++ b/clang-tools-extra/clangd/XRefs.cpp
@@ -1354,6 +1354,8 @@ maybeFindIncludeReferences(ParsedAST &AST, Position Pos,
 
         ReferencesResult::Reference Result;
         const auto *Token = AST.getTokens().spelledTokenAt(Loc);
+        if (!Token)
+          return;
         Result.Loc.range = Range{sourceLocToPosition(SM, Token->location()),
                                  sourceLocToPosition(SM, Token->endLocation())};
         Result.Loc.uri = URIMainFile;
@@ -2012,15 +2014,15 @@ static QualType typeForNode(const SelectionTree::Node *N) {
   return QualType();
 }
 
-// Given a type targeted by the cursor, return one or more types that are more interesting
-// to target.
-static void unwrapFindType(
-    QualType T, const HeuristicResolver* H, llvm::SmallVector<QualType>& Out) {
+// Given a type targeted by the cursor, return one or more types that are more
+// interesting to target.
+static void unwrapFindType(QualType T, const HeuristicResolver *H,
+                           llvm::SmallVector<QualType> &Out) {
   if (T.isNull())
     return;
 
   // If there's a specific type alias, point at that rather than unwrapping.
-  if (const auto* TDT = T->getAs<TypedefType>())
+  if (const auto *TDT = T->getAs<TypedefType>())
     return Out.push_back(QualType(TDT, 0));
 
   // Pointers etc => pointee type.
@@ -2044,17 +2046,18 @@ static void unwrapFindType(
 
   // For smart pointer types, add the underlying type
   if (H)
-    if (const auto* PointeeType = H->getPointeeType(T.getNonReferenceType().getTypePtr())) {
-        unwrapFindType(QualType(PointeeType, 0), H, Out);
-        return Out.push_back(T);
+    if (const auto *PointeeType =
+            H->getPointeeType(T.getNonReferenceType().getTypePtr())) {
+      unwrapFindType(QualType(PointeeType, 0), H, Out);
+      return Out.push_back(T);
     }
 
   return Out.push_back(T);
 }
 
 // Convenience overload, to allow calling this without the out-parameter
-static llvm::SmallVector<QualType> unwrapFindType(
-    QualType T, const HeuristicResolver* H) {
+static llvm::SmallVector<QualType> unwrapFindType(QualType T,
+                                                  const HeuristicResolver *H) {
   llvm::SmallVector<QualType> Result;
   unwrapFindType(T, H, Result);
   return Result;
@@ -2076,10 +2079,11 @@ std::vector<LocatedSymbol> findType(ParsedAST &AST, Position Pos,
     std::vector<LocatedSymbol> LocatedSymbols;
 
     // NOTE: unwrapFindType might return duplicates for something like
-    // unique_ptr<unique_ptr<T>>. Let's *not* remove them, because it gives you some
-    // information about the type you may have not known before
-    // (since unique_ptr<unique_ptr<T>> != unique_ptr<T>).
-    for (const QualType& Type : unwrapFindType(typeForNode(N), AST.getHeuristicResolver()))
+    // unique_ptr<unique_ptr<T>>. Let's *not* remove them, because it gives you
+    // some information about the type you may have not known before (since
+    // unique_ptr<unique_ptr<T>> != unique_ptr<T>).
+    for (const QualType &Type :
+         unwrapFindType(typeForNode(N), AST.getHeuristicResolver()))
       llvm::copy(locateSymbolForType(AST, Type, Index),
                  std::back_inserter(LocatedSymbols));
 
diff --git a/clang-tools-extra/clangd/unittests/XRefsTests.cpp b/clang-tools-extra/clangd/unittests/XRefsTests.cpp
index f53cbf01b7992..c4def624a2fcc 100644
--- a/clang-tools-extra/clangd/unittests/XRefsTests.cpp
+++ b/clang-tools-extra/clangd/unittests/XRefsTests.cpp
@@ -2358,7 +2358,14 @@ TEST(FindReferences, UsedSymbolsFromInclude) {
 
       R"cpp([[#in^clude <vector>]]
         std::[[vector]]<int> vec;
-      )cpp"};
+      )cpp",
+
+      R"cpp(
+        [[#include ^"operator_qoutes.h"]]
+        using ::operator_qoutes::[[operator]]"" _b;
+        auto x = 1_b;
+      )cpp",
+  };
   for (const char *Test : Tests) {
     Annotations T(Test);
     auto TU = TestTU::withCode(T.code());
@@ -2375,6 +2382,11 @@ TEST(FindReferences, UsedSymbolsFromInclude) {
         class vector{};
       }
     )cpp");
+    TU.AdditionalFiles["operator_qoutes.h"] = guard(R"cpp(
+      namespace operator_qoutes {
+        bool operator"" _b(unsigned long long value);
+      }
+    )cpp");
     TU.ExtraArgs.push_back("-isystem" + testPath("system"));
 
     auto AST = TU.build();