[clang][dataflow] Add support for new expressions.

Reviewed By: xazax.hun, gribozavr2

Differential Revision: https://reviews.llvm.org/D147698

diff --git a/clang/lib/Analysis/FlowSensitive/Transfer.cpp b/clang/lib/Analysis/FlowSensitive/Transfer.cpp
index aa8fe90..1d273e7 100644 (file)
--- a/clang/lib/Analysis/FlowSensitive/Transfer.cpp
+++ b/clang/lib/Analysis/FlowSensitive/Transfer.cpp
@@ -469,6 +469,20 @@ public:
     Env.setValue(Loc, Env.create<PointerValue>(*ThisPointeeLoc));
   }
 
+  void VisitCXXNewExpr(const CXXNewExpr *S) {
+    auto &Loc = Env.createStorageLocation(*S);
+    Env.setStorageLocation(*S, Loc);
+    if (Value *Val = Env.createValue(S->getType()))
+      Env.setValue(Loc, *Val);
+  }
+
+  void VisitCXXDeleteExpr(const CXXDeleteExpr *S) {
+    // Empty method.
+    // We consciously don't do anything on deletes.  Diagnosing double deletes
+    // (for example) should be done by a specific analysis, not by the
+    // framework.
+  }
+
   void VisitReturnStmt(const ReturnStmt *S) {
     if (!Env.getAnalysisOptions().ContextSensitiveOpts)
       return;

diff --git a/clang/unittests/Analysis/FlowSensitive/TransferTest.cpp b/clang/unittests/Analysis/FlowSensitive/TransferTest.cpp
index 1bb772a..8f02161 100644 (file)
--- a/clang/unittests/Analysis/FlowSensitive/TransferTest.cpp
+++ b/clang/unittests/Analysis/FlowSensitive/TransferTest.cpp
@@ -5170,4 +5170,66 @@ TEST(TransferTest, NoReturnFunctionInsideShortCircuitedBooleanOp) {
       });
 }
 
+TEST(TransferTest, NewExpressions) {
+  std::string Code = R"(
+    void target() {
+      int *p = new int(42);
+      // [[after_new]]
+    }
+  )";
+  runDataflow(
+      Code,
+      [](const llvm::StringMap<DataflowAnalysisState<NoopLattice>> &Results,
+         ASTContext &ASTCtx) {
+        const Environment &Env =
+            getEnvironmentAtAnnotation(Results, "after_new");
+
+        auto &P = getValueForDecl<PointerValue>(ASTCtx, Env, "p");
+
+        EXPECT_THAT(Env.getValue(P.getPointeeLoc()), NotNull());
+      });
+}
+
+TEST(TransferTest, NewExpressions_Structs) {
+  std::string Code = R"(
+    struct Inner {
+      int InnerField;
+    };
+
+    struct Outer {
+      Inner OuterField;
+    };
+
+    void target() {
+      Outer *p = new Outer;
+      // Access the fields to make sure the analysis actually generates children
+      // for them in the `AggregateStorageLoc` and `StructValue`.
+      p->OuterField.InnerField;
+      // [[after_new]]
+    }
+  )";
+  runDataflow(
+      Code,
+      [](const llvm::StringMap<DataflowAnalysisState<NoopLattice>> &Results,
+         ASTContext &ASTCtx) {
+        const Environment &Env =
+            getEnvironmentAtAnnotation(Results, "after_new");
+
+        const ValueDecl *OuterField = findValueDecl(ASTCtx, "OuterField");
+        const ValueDecl *InnerField = findValueDecl(ASTCtx, "InnerField");
+
+        auto &P = getValueForDecl<PointerValue>(ASTCtx, Env, "p");
+
+        auto &OuterLoc = cast<AggregateStorageLocation>(P.getPointeeLoc());
+        auto &OuterFieldLoc =
+            cast<AggregateStorageLocation>(OuterLoc.getChild(*OuterField));
+        auto &InnerFieldLoc = OuterFieldLoc.getChild(*InnerField);
+
+        // Values for the struct and all fields exist after the new.
+        EXPECT_THAT(Env.getValue(OuterLoc), NotNull());
+        EXPECT_THAT(Env.getValue(OuterFieldLoc), NotNull());
+        EXPECT_THAT(Env.getValue(InnerFieldLoc), NotNull());
+      });
+}
+
 } // namespace