[clang] e6e753d - [clang][dataflow] Fix wrong assert for CXXConstructExpr

[Paul Semel via cfe-commits]

Author: Paul Semel
Date: 2023-02-24T09:51:10Z
New Revision: e6e753d173db14bb1273db65387dec696b7d7a48

URL: https://github.com/llvm/llvm-project/commit/e6e753d173db14bb1273db65387dec696b7d7a48
DIFF: https://github.com/llvm/llvm-project/commit/e6e753d173db14bb1273db65387dec696b7d7a48.diff

LOG: [clang][dataflow] Fix wrong assert for CXXConstructExpr

Differential Revision: https://reviews.llvm.org/D144546

Added: 
    

Modified: 
    clang/lib/Analysis/FlowSensitive/Transfer.cpp
    clang/unittests/Analysis/FlowSensitive/TransferTest.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/Analysis/FlowSensitive/Transfer.cpp b/clang/lib/Analysis/FlowSensitive/Transfer.cpp
index 74dd59851ad44..389865771c16b 100644
--- a/clang/lib/Analysis/FlowSensitive/Transfer.cpp
+++ b/clang/lib/Analysis/FlowSensitive/Transfer.cpp
@@ -561,7 +561,9 @@ class TransferVisitor : public ConstStmtVisitor<TransferVisitor> {
     assert(ConstructorDecl != nullptr);
 
     if (ConstructorDecl->isCopyOrMoveConstructor()) {
-      assert(S->getNumArgs() == 1);
+      // It is permissible for a copy/move constructor to have additional
+      // parameters as long as they have default arguments defined for them.
+      assert(S->getNumArgs() != 0);
 
       const Expr *Arg = S->getArg(0);
       assert(Arg != nullptr);

diff  --git a/clang/unittests/Analysis/FlowSensitive/TransferTest.cpp b/clang/unittests/Analysis/FlowSensitive/TransferTest.cpp
index f626eb0c01548..98021ce0d30b3 100644
--- a/clang/unittests/Analysis/FlowSensitive/TransferTest.cpp
+++ b/clang/unittests/Analysis/FlowSensitive/TransferTest.cpp
@@ -2102,6 +2102,54 @@ TEST(TransferTest, CopyConstructor) {
       });
 }
 
+TEST(TransferTest, CopyConstructorWithDefaultArgument) {
+  std::string Code = R"(
+    struct A {
+      int Baz;
+      A() = default;
+      A(const A& a, bool def = true) { Baz = a.Baz; }
+    };
+
+    void target() {
+      A Foo;
+      (void)Foo.Baz;
+      A Bar = Foo;
+      // [[p]]
+    }
+  )";
+  runDataflow(
+      Code,
+      [](const llvm::StringMap<DataflowAnalysisState<NoopLattice>> &Results,
+         ASTContext &ASTCtx) {
+        ASSERT_THAT(Results.keys(), UnorderedElementsAre("p"));
+        const Environment &Env = getEnvironmentAtAnnotation(Results, "p");
+
+        const ValueDecl *FooDecl = findValueDecl(ASTCtx, "Foo");
+        ASSERT_THAT(FooDecl, NotNull());
+
+        const ValueDecl *BarDecl = findValueDecl(ASTCtx, "Bar");
+        ASSERT_THAT(BarDecl, NotNull());
+
+        const ValueDecl *BazDecl = findValueDecl(ASTCtx, "Baz");
+        ASSERT_THAT(BazDecl, NotNull());
+
+        const auto *FooLoc = cast<AggregateStorageLocation>(
+            Env.getStorageLocation(*FooDecl, SkipPast::None));
+        const auto *BarLoc = cast<AggregateStorageLocation>(
+            Env.getStorageLocation(*BarDecl, SkipPast::None));
+
+        const auto *FooVal = cast<StructValue>(Env.getValue(*FooLoc));
+        const auto *BarVal = cast<StructValue>(Env.getValue(*BarLoc));
+        EXPECT_EQ(FooVal, BarVal);
+
+        const auto *FooBazVal =
+            cast<IntegerValue>(Env.getValue(FooLoc->getChild(*BazDecl)));
+        const auto *BarBazVal =
+            cast<IntegerValue>(Env.getValue(BarLoc->getChild(*BazDecl)));
+        EXPECT_EQ(FooBazVal, BarBazVal);
+      });
+}
+
 TEST(TransferTest, CopyConstructorWithParens) {
   std::string Code = R"(
     struct A {