[clang] [clang][dataflow] Add support for lambda captures (PR #68558)

[Stanislav Gatev via cfe-commits]

================
@@ -5987,4 +6018,204 @@ TEST(TransferTest, EvaluateBlockWithUnreachablePreds) {
          ASTContext &ASTCtx) {});
 }
 
+TEST(TransferTest, LambdaCaptureByCopy) {
+  std::string Code = R"(
+    void target(int Foo, int Bar) {
+      [Foo]() {
+        (void)0;
+        // [[p]]
+      }();
+    }
+  )";
+  runDataflowOnLambda(
+      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 StorageLocation *FooLoc = Env.getStorageLocation(*FooDecl);
+        ASSERT_TRUE(isa_and_nonnull<ScalarStorageLocation>(FooLoc));
+
+        const Value *FooVal = Env.getValue(*FooLoc);
+        EXPECT_TRUE(isa_and_nonnull<IntegerValue>(FooVal));
+
+        const ValueDecl *BarDecl = findValueDecl(ASTCtx, "Bar");
+        ASSERT_THAT(BarDecl, NotNull());
+
+        const StorageLocation *BarLoc = Env.getStorageLocation(*BarDecl);
+        EXPECT_THAT(BarLoc, IsNull());
+      });
+}
+
+TEST(TransferTest, LambdaCaptureByReference) {
+  std::string Code = R"(
+    void target(int Foo, int Bar) {
+      [&Foo]() {
+        (void)0;
+        // [[p]]
+      }();
+    }
+  )";
+  runDataflowOnLambda(
+      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 StorageLocation *FooLoc = Env.getStorageLocation(*FooDecl);
+        ASSERT_TRUE(isa_and_nonnull<ScalarStorageLocation>(FooLoc));
+
+        const Value *FooVal = Env.getValue(*FooLoc);
+        EXPECT_TRUE(isa_and_nonnull<IntegerValue>(FooVal));
+
+        const ValueDecl *BarDecl = findValueDecl(ASTCtx, "Bar");
+        ASSERT_THAT(BarDecl, NotNull());
+
+        const StorageLocation *BarLoc = Env.getStorageLocation(*BarDecl);
+        EXPECT_THAT(BarLoc, IsNull());
+      });
+}
+
+TEST(TransferTest, LambdaCaptureWithInitializer) {
+  std::string Code = R"(
+    void target(int Bar) {
+      [Foo=Bar]() {
+        (void)0;
+        // [[p]]
+      }();
+    }
+  )";
+  runDataflowOnLambda(
+      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 StorageLocation *FooLoc = Env.getStorageLocation(*FooDecl);
+        ASSERT_TRUE(isa_and_nonnull<ScalarStorageLocation>(FooLoc));
+
+        const Value *FooVal = Env.getValue(*FooLoc);
+        EXPECT_TRUE(isa_and_nonnull<IntegerValue>(FooVal));
+
+        const ValueDecl *BarDecl = findValueDecl(ASTCtx, "Bar");
+        ASSERT_THAT(BarDecl, NotNull());
+
+        const StorageLocation *BarLoc = Env.getStorageLocation(*BarDecl);
+        EXPECT_THAT(BarLoc, IsNull());
+      });
+}
+
+TEST(TransferTest, LambdaCaptureByCopyImplicit) {
+  std::string Code = R"(
+    void target(int Foo, int Bar) {
+      [=]() {
+        Foo;
+        // [[p]]
+      }();
+    }
+  )";
+  runDataflowOnLambda(
+      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 StorageLocation *FooLoc = Env.getStorageLocation(*FooDecl);
+        ASSERT_TRUE(isa_and_nonnull<ScalarStorageLocation>(FooLoc));
+
+        const Value *FooVal = Env.getValue(*FooLoc);
+        EXPECT_TRUE(isa_and_nonnull<IntegerValue>(FooVal));
+
+        const ValueDecl *BarDecl = findValueDecl(ASTCtx, "Bar");
+        ASSERT_THAT(BarDecl, NotNull());
+
+        const StorageLocation *BarLoc = Env.getStorageLocation(*BarDecl);
+        EXPECT_THAT(BarLoc, IsNull());
+      });
+}
+
+TEST(TransferTest, LambdaCaptureByReferenceImplicit) {
+  std::string Code = R"(
+    void target(int Foo, int Bar) {
+      [&]() {
+        Foo;
+        // [[p]]
+      }();
+    }
+  )";
+  runDataflowOnLambda(
+      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 StorageLocation *FooLoc = Env.getStorageLocation(*FooDecl);
+        ASSERT_TRUE(isa_and_nonnull<ScalarStorageLocation>(FooLoc));
+
+        const Value *FooVal = Env.getValue(*FooLoc);
+        EXPECT_TRUE(isa_and_nonnull<IntegerValue>(FooVal));
+
+        const ValueDecl *BarDecl = findValueDecl(ASTCtx, "Bar");
+        ASSERT_THAT(BarDecl, NotNull());
+
+        const StorageLocation *BarLoc = Env.getStorageLocation(*BarDecl);
+        EXPECT_THAT(BarLoc, IsNull());
----------------
sgatev wrote:

It's null because `Bar` isn't used in the body of the lambda. I added a comment to make this clear.

https://github.com/llvm/llvm-project/pull/68558