sgatev created this revision.
sgatev added reviewers: ymandel, xazax.hun, gribozavr2.
Herald added a subscriber: rnkovacs.
sgatev requested review of this revision.
Herald added a project: clang.
This is part of the implementation of the dataflow analysis framework.
See "[RFC] A dataflow analysis framework for Clang AST" on cfe-dev.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D117496
Files:
clang/lib/Analysis/FlowSensitive/Transfer.cpp
clang/unittests/Analysis/FlowSensitive/TransferTest.cpp
Index: clang/unittests/Analysis/FlowSensitive/TransferTest.cpp
===================================================================
--- clang/unittests/Analysis/FlowSensitive/TransferTest.cpp
+++ clang/unittests/Analysis/FlowSensitive/TransferTest.cpp
@@ -1699,4 +1699,63 @@
});
}
+TEST_F(TransferTest, AddrOfValue) {
+ std::string Code = R"(
+ void target() {
+ int Foo;
+ int *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 *FooLoc = cast<ScalarStorageLocation>(
+ Env.getStorageLocation(*FooDecl, SkipPast::None));
+ const auto *BarVal =
+ cast<PointerValue>(Env.getValue(*BarDecl, SkipPast::None));
+ EXPECT_EQ(&BarVal->getPointeeLoc(), FooLoc);
+ });
+}
+
+TEST_F(TransferTest, AddrOfReference) {
+ std::string Code = R"(
+ void target(int *Foo) {
+ int *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<PointerValue>(Env.getValue(*BarDecl, SkipPast::None));
+ EXPECT_EQ(&BarVal->getPointeeLoc(), &FooVal->getPointeeLoc());
+ });
+}
+
} // namespace
Index: clang/lib/Analysis/FlowSensitive/Transfer.cpp
===================================================================
--- clang/lib/Analysis/FlowSensitive/Transfer.cpp
+++ clang/lib/Analysis/FlowSensitive/Transfer.cpp
@@ -171,19 +171,45 @@
}
void VisitUnaryOperator(const UnaryOperator *S) {
- if (S->getOpcode() == UO_Deref) {
- assert(S->getSubExpr() != nullptr);
+ // The CFG does not contain `ParenExpr` as top-level statements in basic
+ // blocks, however sub-expressions can still be of that type.
+ assert(S->getSubExpr() != nullptr);
+ const Expr *SubExpr = S->getSubExpr()->IgnoreParens();
+ assert(SubExpr != nullptr);
+
+ switch (S->getOpcode()) {
+ case UO_Deref: {
const auto *SubExprVal = cast_or_null<PointerValue>(
- Env.getValue(*S->getSubExpr(), SkipPast::Reference));
+ Env.getValue(*SubExpr, SkipPast::Reference));
if (SubExprVal == nullptr)
- return;
+ break;
auto &Loc = Env.createStorageLocation(*S);
Env.setStorageLocation(*S, Loc);
Env.setValue(Loc, Env.takeOwnership(std::make_unique<ReferenceValue>(
SubExprVal->getPointeeLoc())));
+ break;
+ }
+ case UO_AddrOf: {
+ // Do not form a pointer to a reference. If `SubExpr` is assigned a
+ // `ReferenceValue` then form a value that points to the location of its
+ // pointee.
+ StorageLocation *PointeeLoc =
+ Env.getStorageLocation(*SubExpr, SkipPast::Reference);
+ if (PointeeLoc == nullptr)
+ break;
+
+ auto &PointerLoc = Env.createStorageLocation(*S);
+ auto &PointerVal =
+ Env.takeOwnership(std::make_unique<PointerValue>(*PointeeLoc));
+ Env.setStorageLocation(*S, PointerLoc);
+ Env.setValue(PointerLoc, PointerVal);
+ break;
+ }
+ default:
+ // FIXME: Add support for UO_LNot.
+ break;
}
- // FIXME: Add support for UO_AddrOf, UO_LNot.
}
void VisitCXXThisExpr(const CXXThisExpr *S) {
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