[clang] [clang][dataflow] Handle CXXInheritedCtorInitExpr in ResultObjectVisitor. (PR #99616)

[Pasquale Riello via cfe-commits]

https://github.com/Pask00 created https://github.com/llvm/llvm-project/pull/99616


`CXXInheritedCtorInitExpr` is another of the node kinds that should be considered an "original initializer". An assertion failure in `assert(Children.size() == 1)` happens without this fix.

>From 0c26f09117baa36308bf58fed0ac40794b04ce74 Mon Sep 17 00:00:00 2001
From: Pasquale Riello <pas.riello at gmail.com>
Date: Fri, 19 Jul 2024 08:34:14 +0000
Subject: [PATCH] [clang][dataflow] Handle CXXInheritedCtorInitExpr in
 ResultObjectVisitor.

`CXXInheritedCtorInitExpr` is another of the node kinds that should be considered an "original initializer". An assertion failure in `assert(Children.size() == 1)` happens without this fix.
---
 .../FlowSensitive/DataflowEnvironment.cpp     |  2 +-
 .../FlowSensitive/DataflowEnvironmentTest.cpp | 40 +++++++++++++++++++
 2 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/clang/lib/Analysis/FlowSensitive/DataflowEnvironment.cpp b/clang/lib/Analysis/FlowSensitive/DataflowEnvironment.cpp
index f734168e647bd..3307981ce7e0f 100644
--- a/clang/lib/Analysis/FlowSensitive/DataflowEnvironment.cpp
+++ b/clang/lib/Analysis/FlowSensitive/DataflowEnvironment.cpp
@@ -416,7 +416,7 @@ class ResultObjectVisitor : public AnalysisASTVisitor<ResultObjectVisitor> {
     // below them can initialize the same object (or part of it).
     if (isa<CXXConstructExpr>(E) || isa<CallExpr>(E) || isa<LambdaExpr>(E) ||
         isa<CXXDefaultArgExpr>(E) || isa<CXXStdInitializerListExpr>(E) ||
-        isa<AtomicExpr>(E) ||
+        isa<AtomicExpr>(E) || isa<CXXInheritedCtorInitExpr>(E) ||
         // We treat `BuiltinBitCastExpr` as an "original initializer" too as
         // it may not even be casting from a record type -- and even if it is,
         // the two objects are in general of unrelated type.
diff --git a/clang/unittests/Analysis/FlowSensitive/DataflowEnvironmentTest.cpp b/clang/unittests/Analysis/FlowSensitive/DataflowEnvironmentTest.cpp
index a4ac597bb06d6..8481026f7c1fc 100644
--- a/clang/unittests/Analysis/FlowSensitive/DataflowEnvironmentTest.cpp
+++ b/clang/unittests/Analysis/FlowSensitive/DataflowEnvironmentTest.cpp
@@ -442,6 +442,46 @@ TEST_F(EnvironmentTest, CXXDefaultInitExprResultObjIsWrappedExprResultObj) {
             &Env.getResultObjectLocation(*DefaultInit->getExpr()));
 }
 
+TEST_F(EnvironmentTest, ResultObjectLocationForInheritedCtorInitExpr) {
+  using namespace ast_matchers;
+
+  std::string Code = R"(
+    struct Base {
+      Base(int b) {}
+    };
+    struct Derived : Base {
+      using Base::Base;
+    };
+
+    Derived d = Derived(0);
+  )";
+
+  auto Unit =
+      tooling::buildASTFromCodeWithArgs(Code, {"-fsyntax-only", "-std=c++20"});
+  auto &Context = Unit->getASTContext();
+
+  ASSERT_EQ(Context.getDiagnostics().getClient()->getNumErrors(), 0U);
+
+  auto Results =
+      match(cxxConstructorDecl(
+                hasAnyConstructorInitializer(cxxCtorInitializer(
+                    withInitializer(expr().bind("inherited_ctor_init_expr")))))
+                .bind("ctor"),
+            Context);
+  const auto *Constructor = selectFirst<CXXConstructorDecl>("ctor", Results);
+  const auto *InheritedCtorInit =
+      selectFirst<CXXInheritedCtorInitExpr>("inherited_ctor_init_expr", Results);
+
+  // Verify that `inherited_ctor_init_expr` has no children.
+  ASSERT_EQ(InheritedCtorInit->child_begin(), InheritedCtorInit->child_end());
+
+  Environment Env(DAContext, *Constructor);
+  Env.initialize();
+
+  RecordStorageLocation &Loc = Env.getResultObjectLocation(*InheritedCtorInit);
+  ASSERT_NE(&Loc, nullptr);
+}
+
 TEST_F(EnvironmentTest, Stmt) {
   using namespace ast_matchers;