[clang] acd4b03 - Revert "Revert "[clang][dataflow] Add a test to justify skipping past references in UO_Deref""

[Stanislav Gatev via cfe-commits]

Author: Stanislav Gatev
Date: 2022-01-19T10:00:01Z
New Revision: acd4b0359097dd8ad166d569a4566879e82a2793

URL: https://github.com/llvm/llvm-project/commit/acd4b0359097dd8ad166d569a4566879e82a2793
DIFF: https://github.com/llvm/llvm-project/commit/acd4b0359097dd8ad166d569a4566879e82a2793.diff

LOG: Revert "Revert "[clang][dataflow] Add a test to justify skipping past references in UO_Deref""

This reverts commit a0262043bb87fdef68c817722de320a5dd9eb9c9.

Add the -fno-delayed-template-parsing arg to fix the failing test on Windows.

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 0979f55c5a5c..865191916e50 100644
--- a/clang/lib/Analysis/FlowSensitive/Transfer.cpp
+++ b/clang/lib/Analysis/FlowSensitive/Transfer.cpp
@@ -182,6 +182,7 @@ class TransferVisitor : public ConstStmtVisitor<TransferVisitor> {
 
     switch (S->getOpcode()) {
     case UO_Deref: {
+      // Skip past a reference to handle dereference of a dependent pointer.
       const auto *SubExprVal = cast_or_null<PointerValue>(
           Env.getValue(*SubExpr, SkipPast::Reference));
       if (SubExprVal == nullptr)

diff  --git a/clang/unittests/Analysis/FlowSensitive/TransferTest.cpp b/clang/unittests/Analysis/FlowSensitive/TransferTest.cpp
index ea035ba013da..eef1240f0da2 100644
--- a/clang/unittests/Analysis/FlowSensitive/TransferTest.cpp
+++ b/clang/unittests/Analysis/FlowSensitive/TransferTest.cpp
@@ -50,7 +50,7 @@ class TransferTest : public ::testing::Test {
                     std::pair<std::string, DataflowAnalysisState<NoopLattice>>>
                     Results,
                 ASTContext &ASTCtx) { Match(Results, ASTCtx); },
-            {"-fsyntax-only",
+            {"-fsyntax-only", "-fno-delayed-template-parsing",
              "-std=" +
                  std::string(
                      LangStandard::getLangStandardForKind(Std).getName())}),
@@ -1758,4 +1758,34 @@ TEST_F(TransferTest, AddrOfReference) {
               });
 }
 
+TEST_F(TransferTest, DerefDependentPtr) {
+  std::string Code = R"(
+    template <typename T>
+    void target(T *Foo) {
+      T &Bar = *Foo;
+      /*[[p]]*/
+    }
+  )";
+  runDataflow(
+      Code, [](llvm::ArrayRef<
+                   std::pair<std::string, DataflowAnalysisState<NoopLattice>>>
+                   Results,
+               ASTContext &ASTCtx) {
+        ASSERT_THAT(Results, ElementsAre(Pair("p", _)));
+        const Environment &Env = Results[0].second.Env;
+
+        const ValueDecl *FooDecl = findValueDecl(ASTCtx, "Foo");
+        ASSERT_THAT(FooDecl, NotNull());
+
+        const ValueDecl *BarDecl = findValueDecl(ASTCtx, "Bar");
+        ASSERT_THAT(BarDecl, NotNull());
+
+        const auto *FooVal =
+            cast<PointerValue>(Env.getValue(*FooDecl, SkipPast::None));
+        const auto *BarVal =
+            cast<ReferenceValue>(Env.getValue(*BarDecl, SkipPast::None));
+        EXPECT_EQ(&BarVal->getPointeeLoc(), &FooVal->getPointeeLoc());
+      });
+}
+
 } // namespace