[clang-tools-extra] dbd1fb8 - [clangd] Avoid crash when summarizing pointer-to-member expr for block-end hint (#76492)

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Author: Nathan Ridge
Date: 2023-12-29T02:18:48-05:00
New Revision: dbd1fb8e6f1e4a8c91059308b286f8f2a9471a8e

URL: https://github.com/llvm/llvm-project/commit/dbd1fb8e6f1e4a8c91059308b286f8f2a9471a8e
DIFF: https://github.com/llvm/llvm-project/commit/dbd1fb8e6f1e4a8c91059308b286f8f2a9471a8e.diff

LOG: [clangd] Avoid crash when summarizing pointer-to-member expr for block-end hint (#76492)

For calls through a pointer to member, CXXMemberCallExpr::getCallee() is
a BinaryOperator with operator ->* (after unwrapping parens).

getMethodDecl() only returns non-null if the callee is a MemberExpr.

Fixes https://github.com/clangd/clangd/issues/1873

Added: 
    

Modified: 
    clang-tools-extra/clangd/InlayHints.cpp
    clang-tools-extra/clangd/unittests/InlayHintTests.cpp

Removed: 
    


################################################################################
diff  --git a/clang-tools-extra/clangd/InlayHints.cpp b/clang-tools-extra/clangd/InlayHints.cpp
index 6fbb310b660a17..5722ca8f66eb72 100644
--- a/clang-tools-extra/clangd/InlayHints.cpp
+++ b/clang-tools-extra/clangd/InlayHints.cpp
@@ -286,7 +286,7 @@ std::string summarizeExpr(const Expr *E) {
     // Step through implicit nodes that clang doesn't classify as such.
     std::string VisitCXXMemberCallExpr(const CXXMemberCallExpr *E) {
       // Call to operator bool() inside if (X): dispatch to X.
-      if (E->getNumArgs() == 0 &&
+      if (E->getNumArgs() == 0 && E->getMethodDecl() &&
           E->getMethodDecl()->getDeclName().getNameKind() ==
               DeclarationName::CXXConversionFunctionName &&
           E->getSourceRange() ==

diff  --git a/clang-tools-extra/clangd/unittests/InlayHintTests.cpp b/clang-tools-extra/clangd/unittests/InlayHintTests.cpp
index 0ca95b5fed5d31..0fff0dfca6c9b8 100644
--- a/clang-tools-extra/clangd/unittests/InlayHintTests.cpp
+++ b/clang-tools-extra/clangd/unittests/InlayHintTests.cpp
@@ -2205,6 +2205,19 @@ TEST(BlockEndHints, Macro) {
                       ExpectedHint{" // struct S1", "S1"});
 }
 
+TEST(BlockEndHints, PointerToMemberFunction) {
+  // Do not crash trying to summarize `a->*p`.
+  assertBlockEndHints(R"cpp(
+    class A {};
+    using Predicate = bool(A::*)();
+    void foo(A* a, Predicate p) {
+      if ((a->*p)()) {
+      $ptrmem[[}]]
+    } // suppress
+  )cpp",
+                      ExpectedHint{" // if", "ptrmem"});
+}
+
 // FIXME: Low-hanging fruit where we could omit a type hint:
 //  - auto x = TypeName(...);
 //  - auto x = (TypeName) (...);